Electronic Doctoral Dissertations for UMass Amherst

L'ap\cx otre des femmes dans la France du XVII\`eme si\`ecle: Saint Vincent de Paul, serviteur et avocat de leur dignit\'e

Delagrange, Agnes Marie — Wed, 22 May 2013 15:21:26 PDT

While XVII$\sp{\rm th}$ century France was fraught with wars, epidemics, never-ending riots, and famine, the name of Saint Vincent de Paul came to be associated with the notion of Charity. When Vincent became a priest at the age of 20, little did he realize the extraordinary role he would play in the history of the Counter-Reformation, with women as his principal allies.^ As a child, Vincent experienced the unique nurturing of his mother's love, and his devotion to the Virgin Mary would play a major part in his spiritual life. At 26, he established his first society of women to help the poor, known as Charite. Later on, he became the spiritual director of a young widow, Louise de Marillac. Their common love for the poor eventually led to the creation of the community of the Daughters of Charity. Unlike cloistered nuns, the members of this new secular community were for the most part peasant girls who were able to perform works of charity throughout France and abroad. A year after establishing the Daughters of Charity, Vincent was asked to form an assembly of aristocratic and bourgeois women in Paris to be given the name Ladies of Charity. These women helped finance most of his projects, and were the decision-makers in an effort to provide one of the first forms of social assistance to the entire country. As Vincent's notoriety spread far and wide, Anne d'Autriche and Louise-Marie de Gonzague, Queen of Poland, came to rely on his guidance for spiritual matters regarding their respective countries.^ Unlike many of his contemporaries, known for their anti-feminism, Saint Vincent de Paul had understood that women have an undeniable role to play as mediators in God's plan of love. The remarkable results of his collaboration with them mark an unprecedented phenomenon in the history of Catholicism and the promotion of women. This partnership is examined closely, along with its impact on the XX$\sp{\rm th}$ century. ^

A constructivist instructional approach to arithmetic word problem-solving: Children as authors and collaborators

Etheredge, Susan Mary — Wed, 22 May 2013 15:21:24 PDT

The National Council of Teachers of Mathematics (1989) has identified problem solving as a major goal of school mathematics. Arithmetic word problem solving is difficult for children. The primary cause of this difficulty is not computational, as once believed, but representational. Children have difficulty understanding and representing the information in the problem.^ The purpose of this study is to design, implement, and evaluate a constructivist instructional approach to help children be successful arithmetic word problem solvers. It is a three week meaning-based approach to problem writing implemented by the teacher in a third grade classroom in a college laboratory school. The approach has children working collaboratively to author their own word problems. Children write math "stories" based on their everyday experiences. The children then write different types of math stories, along the lines of the typology similar to that proposed by Riley, Greeno, & Heller (1983). Children next explore how these math stories can be turned into problems by deriving the many questions that can be asked from any one story, making it into several problems. Subsequent instruction introduces the idea of multi-step, multi-type story problems. The instructional approach is guided by the important underpinnings in constructivist theory of the need for discourse, collaboration, and knowledge construction.^ This dissertation is an empirical study, qualitative and descriptive in nature. My field notes, videotapes, and audiotapes of each day's session, and the children's oral and written work provide the raw data for the study. The schematic knowledge necessary to understand arithmetic word problems and Riley, Greeno, and Heller's word problem typology (1983) serve as the theoretical frameworks for the analysis of the data.^ The data show that children construct the schematic knowledge necessary to understand word problem structure across problem types, knowledge they did not have at the outset of the study. The stories and problems the children create collaboratively and the questions and discussions the children and the teacher pursue together in the spirit of mathematical discourse demonstrate that this approach holds promise as a basis for robust, meaning-based instruction in arithmetic word problem solving. ^

Development of a participatory community video model as a post-literacy activity in Nepal

Tuladhar, Sumon Kamal — Wed, 22 May 2013 15:21:23 PDT

Recognizing literacy as a key to community development, government, non-government and international organizations in Nepal are offering literacy classes as a strategy for community development. Consequently, a great number of neo-literates are emerging every day. However, rural areas of Nepal are not meeting the challenge of neo-literates, as there is still a lack of literate environment. Therefore, literacy professionals in government or non-government organizations are pondering the question of "After literacy what?" and how to sustain people's enthusiasm and skills of literacy so that their energy and skill can be channeled in community development.^ Video technology has pervaded even the rural areas of developing countries like Nepal. However, community members are still media consumers rather than producers. Media technology, like video, can be an effective tool for consciousness raising when used in a participatory approach and developed locally, involving community people.^ Therefore, the present study is to develop a model for participatory community video as a post-literacy activity in Nepal.^ Four major steps have been taken in the study. First, a literature review is done to explore what other developing countries are doing for post-literacy and how much media technology has been integrated in literacy as well as in rural community development. Second, interviews were done with seven Nepal experts to explore their opinions on using video in rural Nepal as a tool for consciousness raising. Third, based on these interviews a model for participatory community video was developed. Fourth, this model was field tested in one of the rural communities in Nepal.^ The field test showed that use of video is an effective tool for adults to raise consciousness and develop leadership quality in neo-literates.^ This study is significant for Nepal because it brings into sharp focus the existence of multiculturalism in the country and efforts to develop indigenous knowledge without local cultural values being wiped out. It provides ambitious neo-literates the opportunity to be creative and to work for their own community rather than migrating to urban areas. Communities will produce their own leaders to cope with globalization through media. ^

On deriving Chinese derived nominals: Evidence for V-to-N raising

Fu, Jingqi — Wed, 22 May 2013 15:21:21 PDT

This dissertation is an investigation of the syntax of Chinese derived nominals. A detailed description of properties characteristic of Chinese derived nominals is given and it is argued that their properties support a syntactic derivation of nominalization and against the Lexicalist Hypothesis (Chomsky 1970).^ Descriptively, it is first established that Chinese derived nominals have the basic properties observed in nominalizations of other languages and this challenges theories of nominalizations of Universal Grammar to account for Chinese as well. For example, derived nominals are ambiguous between two process and result readings. Further, under process reading they exhibit verbal characteristic such as argument taking. Morphologically, it is argued that derived nominals are derived from their verbal counterparts via zero-affixation. It is then shown that Chinese process nominals, but not ordinary nouns, have a mixture of nominal-verbal properties. First, they exhibit both nominal and verbal selectional properties. Second, they exhibit both nominal and verbal structure. For example, they have both nominal and verbal modification and word order. And they behave like a VP in terms of reconstruction effect (Huang 1993) and some context dependent deletion. More importantly, these mixed properties are not unstructured: only certain constituents must show VP characteristics and nominal-verbal structural properties are confined to specific positions.^ It is argued that those mixed properties of derived nominals must be accounted for by an underlying VP. More specifically, the theory of Parallel Morphology (Borer 1993), which links syntactic structure to morphological structure of a word, is shown to account for Chinese derived nominals. Due to their verbal root and nominalizer, derived nominals project both a VP and a NP. This explains all the reference to VP structure and the fact that verbal and nominal properties are confined to specific positions. It is also argued that a Lexicalist account, even a more elaborate one such as that of Grimshaw (1990) fails to capture the dual structural properties of derived nominals because under a lexicalist account, derived nominals are structurally identical to nouns.^ Further prediction of Parallel Morphology is borne out against the nominalization of Chinese serial verb constructions. ^

The hemodynamics of the crustacean open circulatory system: Hemolymph flow in the crayfish ({\it Procambarus clarkii\/}) and the lobster ({\it Homarus americanus\/})

Reiber, Carl Leonard — Wed, 22 May 2013 15:21:11 PDT

The morphology and physiology of crustacean cardiovascular systems has long been regarded as poorly organized and loosely controlled, systems serving only as a conduit to carry hemolymph. Current investigations of cardiovascular systems of decapod Crustacea have revealed an organization that is more complex than previously thought. The purpose of this research is to extend the study of crustacean cardiovascular physiology by investigating the hemodynamics of the freshwater crayfish, Procambarus clarkii, and the lobster, Homarus americanus.^ Crayfish and lobster were exposed to a P$\sb{\rm O\sb2}$ of 150 mmHg (control) followed by P$\sb{\rm O\sb2}$s of 25, 40, 75 and 115 mmHg O$\sb2$. Arterial hemolymph velocities were measured (Pulsed Doppler system) in the major arteries of crayfish and lobster. Hemolymph pressures were measured throughout the circulatory system of the crayfish. The cardiovascular response of hypoxic crayfish to injection of hyperoxic water into the branchial chamber was monitored to determine the location of O$\sb2$ receptors. Heart frequency in both species decreased as water P$\sb{\rm O\sb2}$ was lowered. Cardiac output was maintained in the crayfish due to an increase in stroke volume. Hemolymph flow increased to the anterior aorta only. Hemolymph pressures and ventilatory frequency increased down to a P$\sb{\rm O\sb2}$ of 50 mmHg O$\sb2$; below this all parameters declined. Cardiac output and stroke volume in the lobster were maintained down to a P$\sb{\rm O\sb2}$ of 75 mmHg O$\sb2$; at lower P$\sb{\rm O\sb2}$s cardiac output declined as a result of the hypoxia induced bradycardia. Hemolymph flow increased in the lateral arteries and ventral thoracic artery. Hypoxic crayfish showed a rapid increase in cardiovascular parameters (2.5 second) with a long lag in the respiratory response (75 seconds) to injection of hyperoxic water into their branchial chamber. Injection of hyperoxic water into animals that had defined gill sets removed indicates the presence of O$\sb2$-sensitive chemoreceptors in the posterior region of the branchial chamber.^ The redistribution of cardiac output in crayfish and lobster results in a maintenance of hemolymph flow to the anterior regions of the animals. The maintenance of cardiac output with hypoxia may not be solely related to maintaining M$\sb{\rm O\sb2}$, but may play a role in maintaining oxygen delivery to nervous tissue. The response to a declining water P$\sb{\rm O\sb2}$ is mediated by O$\sb2$ receptors associated with the posterior gills. ^

A class analysis of sharecropping

Kayatekin, Serap Ayse — Wed, 22 May 2013 15:21:06 PDT

The appearance, disappearance and reappearance of sharecropping in different social contexts and different time periods has been regarded as a puzzle by analysts of both the neoclassical and alternative theories. This dissertation is an attempt to define the conceptual terrain from which the puzzle of sharecropping emerges in non-neoclassical theories and to show a way out of this puzzle by conceptualising sharecropping in terms of class as the appropriation and distribution of surplus labour conditioned by different natural and social processes. ^

Walker Percy's cinema-verite

Fister, Charles Francis — Wed, 22 May 2013 15:21:01 PDT

The major novels of Walker Percy are examined for evidence of cinematic stylistic techniques to gain insight into the ways in which Percy achieves his narrative objectives. In particular, his use of "framing" techniques which distance the reader from the characters as well as of cinematic images indicate the kinship between Percy's writing and cinema-verite. Like the cinema-veritist, Percy seeks to alter perception of the boundaries between reader, writer, and character, the seer and the seen.^ Percy's preoccupation with cinema is shown to reflect his philosophical concerns as a Catholic novelist. The metaphors of film, projection, and acting represent modern man's inability to achieve an authentic existence, which can be achieved only through faith. The pervasiveness of cinematic language and image has finally for its object the debunking of cinematic myths. ^

MARXISMS, SOCIALISMS AND COMMUNISMS: AN ANALYSIS AND REFORMULATION OF ECONOMIC DEVELOPMENT AND COMPARATIVE SYSTEMS THEORIES

SILVER, GEOFFREY ALAN — Wed, 22 May 2013 15:20:59 PDT

Attempting to square the concrete realities of post-revolutionary Soviet Union and China with their various notions of communism, participants in the Marxist theoretical tradition have found themselves engaged in polemics contending the definitions of socialism and communism, as well as the basis for their development. The absence of consensus within the Marxian tradition has resolved into a confusing disarray of dogmatic confrontations wherein the proponents of the various schools of thought claim that their respective theories, in comparison to others, have captured (epistemological essentialism) the true essence of social development (ontological essentialism).^ Rejecting the empiricist and rationalist epistemological bases of these confrontations, this dissertation posits an 'Althussarian' notion of overdetermination as an alternative basis with which to critically evaluate the constitutive logic of the contending discourses utilized in attempting to analyze social formations which have experienced 'socialist' revolutions.^ We define three broad traditional theoretical approaches to these issues: economism, humanism, and overdetermination. Rejecting an apodictic posture toward these contending approaches, this dissertation presents a thorough reading of the works of Marx and Engels in demonstration of the exegetical basis of contending discourses. A discussion of J. V. Stalin's writings is presented as an example of one of the predominant forms of essentialist logic. Charles Bettelheim's works are analyzed and compared to Stalin's.^ Both Stalin's and Bettelheim's approaches to questions of socialism and communism are found to reduce social development to ahistorical essential characteristics. Their respective strategies for communist development are thereby reduced to propounding those characteristics proclaimed as essences. Rejecting such reductionist analyses, this dissertation concludes in presentation of the type of analytical fruits that might obtain when approaching these issues within the framework of the tradition demarcated by the notion of a conjuncturally overdetermined communist fundamental class process and its conditions of existence. ^

THE CONSTRUCTION OF MEANING IN A SECOND LANGUAGE: THE IMPORT OF SOCIOCULTURAL CIRCUMSTANCE (PUERTO RICANS; MASSACHUSETTS)

WALSH, CATHERINE ELIZABETH — Wed, 22 May 2013 15:20:51 PDT

This study analyzes the sociocultural and psychological processes involved in the Spanish speaking Puerto Rican child's construction of abstract meaning in the English language and examines how these processes relate to the child's native language reality. Of major interest was the influence of second language learning on both native language memory processes and lexical/semantic relations at differing points in the acquisition process.^ A sample of fifty-four Puerto Rican (representative of our English language ability levels) and thirteen Anglo fourth-grade students from an urban Massachusetts school district were given oral word association tasks in two different treatment modes. In Treatment I, Puerto Rican subjects responded with either a synonymous or defining response to twenty-four Spanish nouns and twenty-four possible English translation equivalents across two intralanguage and two interlanguage conditions. In Treatment II, six Spanish adjectives and their translation equivalents were orally presented to the same subjects in the context of a sentence. Pictures portraying either a home or school setting were paired with the adjectives and presented simultaneously. Again, there were four conditions. Anglo students received only an English-English condition.^ Results demonstrate that the influence of native language meaning is especially strong with regard to culturally salient words and occurs regardless of level of English language proficiency. English meaning was also found to affect Spanish words, especially among mainstreamed students. Interlanguage conditions produced more semantic interference than intralanguage conditions yet, for those subjects in an intermediate stage of English proficiency, meaning for words in all conditions was often confused. In the associations to adjectives and pictures, all subjects were more apt to produce Spanish-type responses.^ The findings suggest that both social context and culture play a dominant role in language acquisition and in semantic organization. A semantic shift accompanies English proficiency; words in the mother tongue take on English meaning. The psychological, sociocultural, and linguistic worlds of the Puerto Rican child appear to be in constant contradiction.^

PHOTOCHEMICAL CROSS-LINKING OF ACETYLAMINOACYL -TRANSFER-RNA TO 16S RNA AT THE P SITE OF ESCHERICHIA COLI RIBOSOMES

PRINCE, JEFFREY BRUCE — Wed, 22 May 2013 15:20:46 PDT

(1) N-Acetyl{('3)H}lysyl-tRNA('Lys) and N-acetyl{('3)H}glutamyl-tRNA(,2)('Glu) were cross-linked to the P site of Escherichia coli 70S tight-couple ribosomes by irradiation with light of 300 to 400 nm. Covalent attachment was dependent on the presence of polynucleotide message and nearly 85% of the ('3)H-labeled amino acids could be released from the cross-linked complexes by puromycin. Cross-linking was stimulated in the presence of acetone and reversed by subsequent exposure to light of 254 nm. Centrifugation of covalent complexes through sucrose gradients revealed that tRNA was attached only to 30S subunits, and further analysis demonstrated that linkage was to 16S RNA, but not to ribosomal proteins. Partial RNase T(,1) hydrolysis of N-acetylaminoacyl-tRNA--16S RNA complexes allowed localization of the site of cross-linking to the 8S RNA fragment derived from the 3' 40% of the 16S RNA. When N-acetyl-aminoacyl-tRNA--8S RNA complexes were electrophoresed in polyacrylamide gels under denaturing conditions, a major fraction of the tRNA was found to be cross-linked to one or more rRNA subfragments of 100-125 nucleotides.^ (2) N-Acetylvalyl-tRNA(,1)('Val) was bound to the P site of uniformly ('32)P-labeled 70S tight-couple ribosomes and cross-linked to 16S RNA in the 30S subunit by irradiation with near ultraviolet light. Following partial RNase T(,1) digestion of N-acetylvalyl-tRNA(,1)('Val)--16S{('32)P}RNA complexes, the rRNA fragments to which the tRNA cross-links were isolated by two-dimensional gel electrophoresis according to the diagonal method. After the first dimension, the tRNA-rRNA cross-link was cleaved by photolysis at 254 nm. Upon electrophoresis in the second dimension, RNA segments previously attached to tRNA migrated to positions beneath the diagonal. The appearance of oligonucleotides below the diagonal was dependent on the presence of tRNA in the initial reaction mixture and required photoreversal of the cross-link. Sequence analysis revealed that the smallest of three nested rRNA fragments containing the site of tRNA attachment encompassed residues 1362 through 1497 of the 16S RNA. Following complete RNase T(,1) hydrolysis of N-acetylvalyl-tRNA(,1)('Val)--16S (('32)P)RNA complexes, the cross-linked tRNA-rRNA oligonucleotide was isolated by polyacrylamide gel electrophoresis. The cross-linked adduct contained a ('32)P-labeled nonanucleotide from the 16S RNA and an unlabeled pentadecanucleotide from the tRNA. The sequence of the nonanucleotide was determined to be U-A-C-A-C-A-C-C-G, which occupies positions 1393-1401 of the 16S RNA and is located within an evolutionarily conserved region. Secondary digestion analysis of the covalent tRNA-rRNA oligonucleotide revealed that the cross-linked residue in the 16S RNA was C(,1400). The site of cross-linking in the tRNA was ascertained using N-acetylvalyl-tRNA(,1)('Val)--16S RNA complexes prepared from nonradioactive ribosomes. After complete RNase T(,1) digestion of these complexes, the RNA was labeled at the 3' end with {5'-('32)P}pCp. The covalent tRNA-rRNA oligonucleotide isolated from the mixture released a single end-labeled component upon photoreversal of the cross-link. Chemical sequence analysis demonstrated that this product was the anticodon-containing pentadecanucleotide of tRNA(,1)('Val), C-A-C-C-U-C-C-C-U-cmo('5)U-A-C-m('6)A-A-G(,39), and that the site of covalent attachment to 16S RNA was the 5' anticodon nucleotide, cmo('5)U(,34). The structure of the cross-linked adduct is proposed to be a cyclobutane dimer between cmo('5)U(,34) of tRNA(,1)('Val) and C(,1400) of the 16S RNA. ^

PSYCHOLOGICAL STUDY OF THE IMPACT OF SYSTEMATIC TRAINING FOR EFFECTIVE PARENTING GROUPS UPON CHILDREN'S BEHAVIOR, ACHIEVEMENT AND SELF-RATINGS AT HOME AND AT SCHOOL

DE SHERBININ, POLLY ROBINSON — Wed, 22 May 2013 15:20:45 PDT

The purpose of this study was to examine the effect of parental participation in a Systematic Training for Effective Parenting (STEP) course upon the classroom behavior and reading achievement of those parents' Title 1 children. Parental perception of child behavior, and children's perception of their own self-concept and locus of control were also examined.^ Parents of Title 1 children in a Northeastern United States elementary school volunteered to participate in the study when it was offered to all Title 1 parents. Their children are assigned to Title 1 for reading tutorials on the basis of teacher recommendations and scoring at least a half grade level on a measure of reading achievement. Eleven parents of 10 children volunteered for the intervention group and 11 parents of 11 children were assigned to the control group.^ The dependent variables were measured in the following manner: classroom behavior was assessed by administering the Devereux Elementary School Behavior Rating Scale to the children's classroom teachers; academic achievement was assessed using the Gates-MacGinitie Reading Tests; children's self-concept was measured by children's responses to the McDaniel-Piers Young Children's Self-Concept Scale; children's locus of control was measured by children's responses to the Pre-Primary Nowicki-Strickland Internal-External Scale; changes in the children's behavior at home were measured by administering the Adlerian Parental Assessment of Child Behavior Scale to parents. The same measures were administered to teachers, children and parents for the intervention and for the control groups. All of the measures were administered pre- and post-treatment in February and ten weeks later in April except for the reading tests which were administered in September and again in May.^ A t-test of the differences between means of the pre-test and of the post-test scores between intervention and control groups was performed as well as the differences between pre- and post-test means within each group. Analysis of the data showed that there were no statistically significant differences for any of the variables.^ In addition, intervention group parents responded to a post-test questionnaire and to an eight-week follow-up interview. All parents reported perceiving changes in their own and in their children's behavior at home and some of them perceived changes in their children's behavior at school.^ Suggestions were made for further research: (a) adding follow-up measures, (b) initially selecting a larger population from which to seek volunteers for parent education, (c) using other measures for assessing teachers' and parents' perception of child behavior, and other means of assessing reading achievement. ^

THE LANGUAGE OF THE ALEMANNIC VERSION OF THE SERMONS OF JOHANNES TAULER

MOSHER, ARTHUR DAVID — Wed, 22 May 2013 15:20:43 PDT

RECOLONIZATION OF AMERICAN SHAD, ALOSA SAPIDISSIMA (WILSON) ABOVE RAINBOW DAM FISHLADDER, FARMINGTON RIVER, CONNECTICUT.

MOFFITT, CHRISTINE MARIE — Wed, 22 May 2013 15:20:42 PDT

SYMBOLIZATION AND LEARNING COMPETENCE: AN ELABORATION OF THE THEORY OF DEVELOPMENT OF THE ANISA MODEL.

MARKS, GEOFFRY WARREN — Wed, 22 May 2013 15:20:38 PDT

MYTHOLOGY AND AUTOBIOGRAPHY IN E. A. ROBINSON'S "TRISTRAM."

MULLIGAN, LOUISE GRIFFITH — Wed, 22 May 2013 15:20:36 PDT

AN OVER-VIEW OF WESTERN AND ISLAMIC EDUCATION.

LATEEF, YUSEF ABDUL — Wed, 22 May 2013 15:20:35 PDT

EMPATHY TRAINING AS THE MAJOR THRUST OF A STAFF DEVELOPMENT PROGRAM.

LA MONICA, ELAINE LYNNE — Wed, 22 May 2013 15:20:34 PDT

The local production of welfare humanitarianism in neoliberal Turkey

Zencirci, F. Gizem — Wed, 22 May 2013 15:20:26 PDT

The primary research question that guides this dissertation is: What is the relationship between neoliberalism and welfare governance? In contrast to the idea that market reforms bring the destruction of social welfare provision, I argue that market reforms are actually accompanied by new practices of—public and private—giving. An analysis of a wide range of welfare institutions and their practices, ethics and ideas about poverty, equality and generosity in Turkey highlights that processes of economic liberalization produce new paradigms of welfare governance, instead of dismantling it. ^ This dissertation utilizes interpretive and ethnographic methods through a case-study of state and non-state social service provision in Turkey in order to answer this question. During a 14-month fieldwork in Turkey between June 2009-August 2010 I participated in the volunteer meetings, fundraising events and assistance distribution days of religious and secular charity organizations, met with the volunteers, teachers and beneficiaries of university social responsibility programs and corporate philanthropy projects. The empirical data consists of 72 in-depth (structured as well as open-ended) interviews with a range of informants, archival materials concerning the historical evolution of social policy in Turkey from 1930 to 2010 and other brochures, pamphlets and media artifacts related to welfare policy. ^ Accordingly, this dissertation presents two main arguments. First, it posits that, market reforms instead of destroying welfare structures and cultures, actually create a humanitarian notion of welfare, which I define as welfare humanitarianism. Second I argue against the diffusion hypothesis which claims that neoliberal technologies of governance travel from the global to the local. In contrast, this dissertation emphasized the local production of neoliberalism. Such an analytical perspective highlights the ways in which neoliberal modes of governance shape and is shaped by local political projects. Lastly, by comparing how secularist and Islamist political groups have discussed the topic of `social policy' in Turkey, I argue that instead of a `divide', these two political constituencies are actually bound by a shared understanding about state, society and economy.^

Assembly of surface engineered nanoparticles for functional materials

Yu, Xi — Wed, 22 May 2013 15:20:25 PDT

Nanoparticles are regarded as exciting new building blocks for functional materials due to their fascinating physical properties because of the nano-confinement. Organizing nanoparticles into ordered hierarchical structures are highly desired for constructing novel optical and electrical artificial materials that are different from their isolated state or thermodynamics random ensembles. My research integrates the surface chemistry of nanoparticles, interfacial assembly and lithography techniques to construct nanoparticle based functional structures. We designed and synthesized tailor-made ligands for gold, semiconductor and magnetic nanoparticle, to modulate the assembly process and collective properties of the assembled structures, by controlling the key parameters such as particle-interface interaction, dielectric environments and inter-particle coupling etc. Top-down technologies such as micro contact printing, photolithography and nanoimprint lithography are used to guide the assembly into arbitrarily predesigned structures for potential device applications.^

Bayesian anatomy of galaxy structure

Yoon, Ilsang — Wed, 22 May 2013 15:20:24 PDT

In this thesis I develop Bayesian approach to model galaxy surface brightness and apply it to a bulge-disc decomposition analysis of galaxies in near-infrared band, from Two Micron All Sky Survey (2MASS). The thesis has three main parts. ^ First part is a technical development of Bayesian galaxy image decomposition package GALPHAT based on Markov chain Monte Carlo algorithm. I implement a fast and accurate galaxy model image generation algorithm to reduce computation time and make Bayesian approach feasible for real science analysis using large ensemble of galaxies. I perform a benchmark test of G ALPHAT and demonstrate significant improvement in parameter estimation with a correct statistical confidence. ^ Second part is a performance test for full Bayesian application to galaxy bulge-disc decomposition analysis including not only the parameter estimation but also the model comparison to classify different galaxy population. The test demonstrates that GALPHAT has enough statistical power to make a reliable model inference using galaxy photometric survey data. Bayesian prior update is also tested for parameter estimation and Bayes factor model comparison and it shows that informative prior significantly improves the model inference in every aspects. ^ Last part is a Bayesian bulge-disc decomposition analysis using 2MASS K_s-band selected samples. I characterise the luminosity distributions in spheroids, bulges and discs separately in the local Universe and study the galaxy morphology correlation, by full utilizing the ensemble parameter posterior of the entire galaxy samples. It shows that to avoid a biased inference, the parameter covariance and model degeneracy has to be carefully characterized by the full probability distribution.^

Helical ordering in chiral block copolymers

Zhao, Wei — Wed, 22 May 2013 15:20:24 PDT

The phase behavior of chiral block copolymers (BCPs*), namely, BCPs with at least one of the constituent block is formed by chiral monomers, is studied both experimentally and theoretically. Specifically, the formation of a unique morphology with helical sense, the H* phase, where the chiral block forms nanohelices hexagonally embedded in the matrix of achiral block, is investigated. Such unique morphology was first observed in the cast film of polystyrene- b-poly(L-lactide) (PS-b-PLLA) from a neutral solvent dichloromethane at room temperature with all the nanohelices being left-handed, which would switch to right-handed if the PLLA block changes to PDLA. Further studies revealed that such morphology only forms when the chiral PLLA block possesses certain volume fraction (from 0.32 to 0.36), and the molecular weight exceeds certain critical value (around 20,000 to 25,000 g/mol). Achiral phases such as lamellae, gyroid, cylinder, and sphere will form if the above criteria are not satisfied. Even though the unique H* phase has been extensively studied and utilized for many applications, many fundamental and important questions remain unanswered for such BCP* system. Specifically, how does the molecular level chirality transfer from the several-angstrom scale of the lactide monomer to the tens-of-nanometer size scale of the H* domain morphology? Why is the chirality transfer not automatic for this BCP* system? Is H* phase a thermodynamic stable or metastable phase? Are there other novel phases other than the H* phase that could form within the BCP* system? ^ We aimed at providing answers to the abovementioned questions regarding the formation of chiral H* phase, which is no longer limited to the PS- b-PLLA/PDLA system. We divided our studies into both experimental and theoretical parts. In the experiments, we studied the effect of solvent casting conditions, including solvent removal rate and polymer-solvent interactions, on the formation of the H* phase in PS-b-PLLA/PDLA BCPs*. In addition, we monitored the morphological evolution during solvent casting using time-resolved x-ray scattering technique. We found that good solubility towards both PS and PLLA/PDLA blocks are required for the formation of the H* phase, and microphase separation has to happen prior to crystallization of chiral block. Most importantly, we found that crystalline ordering is not necessary for the H* phase formation. This result led us to propose melt-state twisted molecular packing as the underlying driving force for such helical phase to form, and began our work on the theory for BCPs*. First we built the theoretical tool by incorporating the orientational segmental interactions into the self-consistent field theory (SCFT) for BCPs. As a demonstration, we constructed the phase diagrams for one-dimensional (1D) and two-dimensional (2D) phases, for achiral BCPs with different orientational stiffness. We found that orientational stiffness could serve as another parameter to introduce asymmetry into BCP systems, in addition to conformational and architectural asymmetry. This model was further applied to study the phase behavior of BCPs*, and two phase diagrams were constructed. Another chiral phase, wavy lamellae (L* phase), was observed for BCPs*. The H* phase was found to be a thermodynamic stable phase, as long as the segregation strength χN and chiral strength q₀ exceed certain critical values. Energetically favorable cholesteric texture was observed for the chiral segment packing inside the H* phase, which is believed to drive such unusual morphology to form. A simple geometrical argument based on bending of cylindrical microdomain and twisted packing of the bended microdomain can be given to explain the nonlinear chiral sensitivity of BCP* morphology, which further explains the non-automatic feature of chirality transfer in such system. ^

Parents' socioeconomic class position and children's time use patterns

Yetis Bayraktar, Ayse — Wed, 22 May 2013 15:20:23 PDT

This dissertation investigates the role of early time use socialization on social class reproduction and status attainment. I investigate the relationship between parents' class position and children's early (ages 6-12) time use patterns based on Lareau's (2003) discussion of different parenting styles across social classes. Contrary to Lareau's findings about the aversion middle class parents have to television, I find that children of more educated parents spend more time watching television than children of less educated parents, except on Fridays. Similar to Lareau's findings about increased homework time with parental education, I find that more educated parents' children spend more time doing homework than children of less educated parents, except on Fridays. This significant decline in both television and homework time on Fridays suggests that more educated parents' children trade these two activities for other activities. I also find that the traditional way of calculating the weekly time spent on a given activity ((weekday time*5)+(weekend time*2)) assumes that each day is identical (Hofferth & Sandberg, 2004), and overlooks the differences in within weekdays and weekends days, respectively. In addition, I find that controlling for type of diary reporter (adult vs. child) introduces a possible reporter bias related to the un/desirability of certain activities. ^

Racialized spaces in teacher discourse: A critical discourse analysis of place-based identities in Roche Bois, Mauritius

Wiehe, Elsa M — Wed, 22 May 2013 15:20:22 PDT

This eleven-month ethnographic study puts critical discourse analysis in dialogue with postmodern conceptualizations of space and place to explore how eight educators talk about space and in the process, produce racialized spaces in Roche Bois, Mauritius. The macro-historical context of racialization of this urban marginalized community informs the discursive analysis of educators' talk at school. Drawing on theories of race that call for the non-deterministic exploration of race relations as they occur in different contexts and times (Hall, 2000; Pandian & Kosek, 2003; Essed & Goldberg, 2000), I explore the spatial racialization of children in Roche Bois as a process specific to this township and its history. Engaging with Lefebvre's three-dimensional theorization of space (Lefebre, 1991) as well as the Discourse Historical Approach developed by Wodak and colleagues (Wodak & Reisgl, 1999), I draw on the micro-macro concept of identity construction "strategy" to study 1) how meanings of race play out as an amalgam of various thematic dimensions of schooling, culture, bodies, and work that are spatialized; 2) how meanings of place perpetuate or transform long-standing historical constructions of Creole identity in Roche Bois. The findings show that repeated patterns of educators' spatial racialization produce and reproduce conceived spaces (Lefebvre, 1991) and yet my research also highlights that banal moments of lived space (Lefebvre, 1991) also exist, as ordinary disruptions of the spatial order produced by patterns of conceived space. While educator discourse for the most part negatively emplaces and racializes the children, one educator's representations of place and race both assimilates and differentiates marginal identities, encourages unity and essentialism at the same time as promotes hybridity. The analysis therefore shows that discourses of place are not totalizing and that moments of interruption can be the basis for thinking of teacher education and practice as a politics of "decolonization" and "reinhabitation" (Gruenewald, 2003). Specifically, the findings indicate the importance of reinvesting critical historical meanings into pedagogies of the local.^

The process of organizational capacity development in action in post-conflict setting of the Literacy Department of Afghanistan

Wajdi, Habibullah — Wed, 22 May 2013 15:20:21 PDT

This paper presents a model of capacity development for public organizations in post-conflict settings. The paper reveals the challenges faced by the author as a `change agent' who tried to understand and develop the basic capacity of the Literacy Department of the Ministry of Education in Afghanistan. The author used an action-research approach and has actively followed events and actions to explore the `how can' of capacity development efforts. The review of organizational change literature provided background knowledge for the author's day-to-day work in a public organization and helped him to develop a Foundational Capacity Development Framework (FCDF). The FCDF offers four complementing components of infrastructure, technical competence, social and organizational participation, and strategic alignment . The framework also recognizes the importance of underlying components of capacity development which are based on the beliefs, values, behavior, ownership, sustainment and institutionalization. The four components in the framework are utilized in ways that address the underlying causes to change individual beliefs and values, creating ownership and empowerment for the sustainment and institutionalization of capacity development efforts in public organizations. ^

Dynamic secrets in communication security

Xiao, Sheng — Wed, 22 May 2013 15:20:21 PDT

This dissertation focuses on both theoretic and practical aspects of using a new approach, dynamic secrets, to provide secrecy to cryptographic keys in secure communications. In the conventional paradigm of communication security, cryptographic keys and the users' communication are independent. The cryptographic keys are generated using dedicated algorithms, protocols, and even specialized hardware. Contrarily, the dynamic secrets approach extracts shared secrecy from the users' communication traffic to generate and update the cryptographic key. ^ The dynamic secrets approach offers several distinctive security benefits over conventional cryptographic key management approaches. Dynamic secrets can harvest true randomness from the communication channel and render the cryptographic key truly random without using any random number generator. Dynamic secrets can quickly and automatically restore a stolen cryptographic key by frequently updating the key using the secrecy extracted from users' communication traffic. Last but not least, dynamic secrets provide an extremely accurate method to detect intrusions to the secure communication system when a stolen key is used. ^ We present the dynamic secrets approach in a secure packet communication model and verify its applicability in practical secure wireless communication scenarios. We further explore the security properties of dynamic secrets from a theoretic perspective and prove that dynamic secrets can achieve near optimal utilization of all possible secrecy in a secure communication. ^ In this dissertation, we study the application of dynamic secrets in smart grid communications, where scalability and many other engineering factors are considered. We also investigate possible theoretic outreaches of dynamic secrets and find the reliability theory in system engineering as an important quantitative methods to evaluate the consistency of communication security. Finally, we present several dynamic secrets related topics as potential research directions.^

Molecular designs for charge and ion transporting materials

Wanwong, Sompit — Wed, 22 May 2013 15:20:20 PDT

High temperature anhydrous proton conducting polymer and optoelectronic based organic compounds are promising materials for use in renewable energy applications. Fundamental understanding of better proton and charge transport properties are required to achieve desirable alternative energy materials. ^ In this thesis, we focus on molecular design, synthetic approaches, and understanding structure-property relationships to improved proton conductivity and optoelectronic properties. In proton conducting polymers, we tethered N-heterocycles (imidazole and benzotriazole) as proton carrier in two polymer systems; dendritic-linear block copolymers and helical polymers. Dendritic-linear block copolymers functionalized with imidazole and benzotriazole are designed to self-organize into nano scale assemblies that would increase local charge density and enhance proton conductivity. We found that microphase separation within disordered structure of imidazole-based block copolymers could relate to the higher conductivity compared to benzotriazole-based block copolymers that do not have phase separation in the same length scale. ^ In the second system, we have focused on effect of chirality on proton conductivity in helical polymer. We functionalized L-histidine and histamine on poly(phenylacetylene) and poly(4-vinylbenzoate). Poly(phenylacetylene) is known as dynamic helical polymer while poly(4-vinylbenzoate) is a random polymer. Effects of backbone chirality, side chains and doping acids on proton conductivity are evaluated in this work. We found that a single handed conformation of poly(phenylacetylene) bearing L-histidine can enhanced proton conductivity compared to those of containing histamine. Whereas, vinyl backbone, poly (4-vinylbenzoate) bearing L-histidine exhibited lower conductivity due to a higher T_g of the polymer. ^ Cyclopentadithiophene (CPDT) derivatives are often used as an active layer in optoelectronic devices. However, CPDT is known to have a low absorption at the lower energy band. To solve this issue, we proposed to change the conformation of heteroatom at the bridgehead. We incorporated ketone and imine functionalities at the bridgehead positions, anti and syn. We found that by changing heteroatom position to syn-position increased absorption intensity in the lower energy band. Incorporation of a ketone at anti-position provides good mobility of 0.003 cm²/Vs while, changing the ketone group at the syn-position significantly decrease charge mobility.^

Fan communities and subgroups: Exploring individuals' supporter group experiences

Tyler, Bruce David — Wed, 22 May 2013 15:20:19 PDT

The aggregate of a sport team's fans may be viewed as a consumption community that surrounds the team and its brand (Devasagayam & Buff, 2008; Hickman & Ward, 2007). Beneath this larger consumption umbrella, smaller groups of consumers may exist (Dholakia, Bagozzi, & Pearo, 2004), such as specific supporter groups for a team. Individuals thus may identify with multiple layers of the consumption group simultaneously (Brodsky & Marx, 2001; Hornsey & Hogg, 2000). Although past researchers have studied supporter groups (Giulianotti, 1996, 1999a; Parry & Malcolm, 2004) and consumption communities (Kozinets, 2001; Muñiz & O'Guinn, 2001; McAlexander, Schouten, & Koenig, 2002), there has been limited research on the interaction among subgroups within the superordinate group. ^ The current study examines the American Outlaws (AO), a supporter group for the United States men's national soccer team (USMNT). AO members belong to local AO chapters (subgroups) as well the national (superordinate) group. This structure creates multiple levels of identification and is conducive to studying the phenomenon in question. Through employing a grounded theory methodology, data were collected via participant observation and ethnographic interviews over a two year period. ^ The current study identifies six prominent foci of identification among AO members: the USMNT, the United States of America (national identity), the sport of soccer, AO National, AO Local, and one's small social group. These identities are found to be mutually reinforcing and shape members' interactions with the team, the supporter group, and social groups therein. Specifically, the regional subgroups (AO Local chapters) create opportunities for social interaction, which fosters members' sense of community and group identification. In turn, this strengthens group cohesion at the subgroup and superordinate group levels. Further, supporter group members alter their team consumption experiences by creating places of prolonged identity salience at live games and when watching games on television. These events increase identification with the supporter group and its related identities. For practitioners, implications of this study include the understanding of supporter groups' impact on members' frequency and duration of brand-related consumption.^

From Diagnosis to Intervention: Charting the Path with Families of Young Children with Autism Spectrum Disorder

Tyner, Scott M — Wed, 22 May 2013 15:20:18 PDT

The growing number of children diagnosed with Autism Spectrum Disorder (ASD) warrants better understanding of how clinicians and families work together following a child's diagnosis. Individuals with ASD share pronounced differences in communication and styles of social interaction along with the presence of repetitive behaviors and restricted interests when compared with people who are neurotypical (NT). Separately, or combined, these differences account for a significant degree of challenging behavior among children with ASD. Challenging behavior can often interfere with a child's participation in learning experiences at home and at school and may lead to placements in more restrictive educational settings, or a lower quality of life at home. This study examined the extent to which parental involvement in their child's behavioral support planning and the utilization of social support networks influenced parental well-being, levels of advocacy, and satisfaction with service providers. Thirty parents of young children with ASD between two and eleven years old (n= 30) were surveyed using the Collaborative Behavioral Support Parent Questionnaire (CBSPQ), a 30-item, 7 point Likert type scale. Social support was found to be positively related parental well-being. Additionally, there was a correlation between collaborative behavioral support and the degree to which parents advocated for themselves and their child. Parents who worked closely with their child's treatment team were also more satisfied with services for their children. Follow-up interviews with a subset of the broader sample enlarged understanding of these relationships.^

Protein transduction domain mimics by ROMP and their bioactive cargo delivery

Tezgel, Arife Ozgul — Wed, 22 May 2013 15:20:17 PDT

Currently, most of the commercially available therapeutics are all targeting cell surface receptors which constitutes only a small portion of the targets found in the cells. Therefore, reaching intracellular targets would provide many new opportunities to treat various diseases. However, intracellular delivery of therapeutic molecules has always been a challenge due to the poor permeability of cell membrane to large, negatively charged macromolecules and their restricted biodistribution. In the past decades, cell penetrating peptides (CPPs), also known as protein transduction domains (PTDs), are shown to improve the intracellular delivery of bioactive molecules and among the PTDs, arginine-rich peptides are highlighted as the most effective subclass. In the light of this information, using the power of polymer chemistry, protein transduction domain mimics (PTDMs) based on ring opening metathesis polymerization (ROMP) of functionalized oxanorbornene derivatives are aimed to be designed. This thesis demonstrates that these PTDMs can adopt cell penetrating activity and show superior properties compared to peptide analogues (i.e. nonaarginine, R9, Pep-1). The structure-activity relationship is studied by guanidinium functionalized monomers. The impact of number of guanidiniums, density of guanidiniums, molecular length and hydrophobicity on cellular internalization is investigated. Further, the siRNA delivery ability of designed PTDMs is also studied. Efficient downregulation of NOTCH1 protein using PTDM-based non-covalent siRNA delivery system in T cell lines and primary blood cells is demonstrated. Two different structures of PTDMs are studied to understand the structural requirements for an efficient carrier. Apart from in vitro testing of PTDM/siRNA complexes, their size and surface charge are also characterized. Further, PTDM-based siRNA delivery system is used to study the function of NOTCH1 in in vitro in primary human blood cells and as well as in humanized mouse model of graft vs host disease as an in vivo environment. In addition to siRNA delivery, novel protein transporter PTDMs which are inspired by primary amphipathic peptides is introduced. The effects of different functional groups and different block lengths on protein delivery efficiency are studied. Successful delivery of functional proteins is demonstrated using Cre Recombinase and Runx1.d190.^

Engineering functional nanostructures for materials and biological applications

Subramani, Chandramouleeswaran — Wed, 22 May 2013 15:20:16 PDT

Engineering nanostructures with complete control over the shape, composition, organization of the surface structures, and function remains a major challenge. In my work, I have fabricated nanostructures using functional polymer motifs and nanoparticles (NPs) via supramolecular and non-supramolecular interactions. In one of the approaches to generate nanostructures, I have integrated top-down approaches such as nanoimprint lithography, electron-beam lithography, and photolithography with the self-assembly (bottom-up) of NPs to provide nanostructures with tailored shape and function. In this strategy, I have developed a geometrically assisted orthogonal assembly of nanoparticles onto polymer features at precisely defined locations. This versatile NP functionalization method can be used to fabricate protein resistant patterned surfaces to provide essentially complete control over cellular alignment, making them promising biofunctional structures for cell patterning. In another approach, I have utilized self-assembly of dendrimers and NPs without preformed templates to generate nanostructures that can be used as chemoselective membranes for the separation of small and biomacromolecules.^

Synthetic mimics of antimicrobial peptides from aryl scaffolds

Thaker, Hitesh — Wed, 22 May 2013 15:20:16 PDT

The rise in bacterial resistance and the declining approval rate of novel anti-infective drugs are a major threat to global public health. Antimicrobial peptides (AMPs), found in almost every multicellular organism, have attracted considerable attention as models for the design of new therapeutic agents due to their broad spectrum activity and reduced bacterial resistance development. This dissertation focuses on the development of a new series of synthetic mimics of antimicrobial peptides (SMAMPs) from simple aryl scaffolds using Suzuki Miyaura coupling. This novel design allows easy tuning of the conformation, overall hydrophobicity of the molecule, amphiphilicity, and the number of charges in order to develop a structure-activity relationship. The antimicrobial activities of the SMAMPs against both gram-positive and gram-negative bacteria suggest that improving the selectivity requires fine-tuning of one or more of these parameters, with overall hydrophobicity and charge having a more significant impact than conformational rigidity. Furthermore, comparing the activities of SMAMPS with facially amphiphilic and disrupted amphiphilic topologies confirmed that amphiphilicity is an important design parameter for attaining antimicrobial activity, especially against gram-negative bacteria. This aryl scaffold design has led to the development of several highly active SMAMPs with selectivities >200 against both gram-positive S. aureus and gram-negative E. coli, which is nearly 20 times higher than that of the conventional AMP, MSI-78. One of these SMAMPs also shows a unique immunomodulatory response involving the induction of both cytokines and chemokines, which can have significant therapeutic potential. Similar chemistry was employed in the development of novel lipopeptide mimics (LPMs), where the attachment of pendant aliphatic chains to the tri-aryl backbone structure can be used to modulate the activity. ^ The second project in this dissertation concerns the investigation of the influence of the cobalt density in the phase-separated domains in the ferromagnetic block copolymer materials A series of metal-containing block-random copolymers composed of an alkyl-functionalized homo block (C₁₆) and a random block of cobalt complex- (Co) and ferrocene complex-functionalized (Fe) units was synthesized via ring-opening metathesis polymerization (ROMP). Taking advantage of the block-random architecture, the influence of dipolar interactions on the magnetic properties of these nanostructured BCPs was studied by systematically varying the molar ratio of the Co units to the Fe units, while maintaining the cylindrical phase-separated morphology. A decrease in the cobalt density weakens the dipolar interactions between the cobalt nanoparticles, leading to the transition from a room temperature ferromagnetic material to a superparamagnetic material. These results confirm that the dipolar interactions of the cobalt nanoparticles within the phase-separated domains are responsible for the (unexpected) room temperature ferromagnetic properties of the nanostructured BCPs.^

Interactions between a gall making fly, Dasineura oxycoccana (Diptera: Cecidomyiidae), and its host plant, cultivated cranberry (Vaccinium macrocarpon)

Tewari, Sunil — Wed, 22 May 2013 15:20:14 PDT

Cranberry tipworm, Dasineura oxycoccana Johnson (a gall-making fly), disrupts normal growth of cranberry (Vaccinium macrocarpon Aiton) by injuring the apical meristem of shoots or uprights. The impact of larval feeding injury on reproductive parameters of cranberry was determined, from one growing season to next, at upright (Maine and Massachusetts, 2008–2009) and plot levels (Massachusetts, 2009–2010 and 2010–2011). I also estimated the proportions of uprights injured because of tipworm feeding at several cranberry production sites (Massachusetts and Maine) and the proportions of uprights that produced flowers and fruits in the next growing season. Tipworm-injured uprights tagged at the end of the growing season did not produce floral-units (following year) across sites in both Massachusetts and Maine. There was significant variation among the sampled sites in the proportions of tipworm-injured uprights and also in the proportions of uprights with flowers in the next growing season (Massachusetts and Maine). A trend was apparent wherein sites with higher tipworm injury levels had relatively lower flowering proportions in the next growing season. However, sites in Massachusetts did not differ in the proportions of uprights that set fruit and in a replicated study, significant reduction in tipworm injury at plot level (using insecticide) did not impact flower and fruit production in the next growing season. A two-year field study was carried out at three different locations to determine the impact of tipworm feeding injury on the reproductive and vegetative growth of two cranberry cultivars ('Howes' and 'Stevens') in Massachusetts. Individual uprights of cranberry exhibited tolerance to natural (tipworm) and simulated apical meristem injury in the current growing season (fruit production) and results were corroborated by a greenhouse study. In the field study, weight of fruit was higher in tipworm-injured uprights as compared with intact control uprights at the sites with Howes. However, majority of injured uprights (tipworm and simulated) did not produce new growth from lateral buds (side-shoots) before the onset of dormancy. In the next growing season, fewer injured uprights resumed growth and produced flowers as compared with intact uprights at two of the three sites.^

Interactions between floral mutualists and antagonists, and consequences for plant reproduction

Soper Gorden, Nicole L — Wed, 22 May 2013 15:20:13 PDT

While pollinators and leaf herbivores have been a focus of research for decades, floral antagonists have been studied significantly less. Since floral antagonists can be as common as leaf herbivores and have strong impacts on plant reproduction, it is important to understand the role of floral antagonists in the ecology and evolution of flowers. I conducted four experiments to better understand the relationship between plants, floral traits, floral antagonists, and other plant-insect interactions. First, I manipulated resources (light and soil nutrients) that are known to have impacts on plants and floral traits to test how they affect floral antagonists and other plant-insect interactions. Plentiful resources increased the proportion of floral antagonists to visit flowers, but also increase tolerance of floral antagonists. Second, I manipulated flower bud gallers, a species-specific floral herbivore that destroys flowers, to test how it affected other plant-insect interactions, floral traits, and plant reproduction. Plants with flower bud gallers tended to have more pollinator visits, but this effect is due to a shared preference by gallers and pollinators for similar plants. Third, I manipulated florivory to examine how it affects subsequent plant-arthropod interactions, floral traits, and plant reproduction. Florivory had systemic effects on other plant-insect interactions, including leaf herbivores, and shifted the plant mating system towards more selfing. Additionally, I tested how several floral antagonists respond to floral attractive and defense traits to understand which floral traits are important in mediating antagonisms. Finally, I manipulated florivory, pollination, and nectar robbing to test for effects of multiple floral interactions on subsequent plant-insect interactions, floral traits, and plant reproduction. There were significant many-way interactions between the three treatments on subsequent plant-insect interactions and reproduction, indicating that the effect of one interaction depends on what other interactions are present. Understanding the role that floral antagonists play in plant ecology can help scientists determine which interactions are most important, and may help determine why some floral traits exist in their current state. Together, this work represents some of the most comprehensive research on the community consequences of floral antagonists, as well as the interplay between floral traits and floral interactions. ^

Remember where we came from: Globalization and environmental discourse in the Araucania region of Chile

Stephens, Niall — Wed, 22 May 2013 15:20:12 PDT

Based on an ethnographic investigation, the dissertation examines the emergence and significance of discourses around "the environment" in the Lake District of the Araucanía region of Chile (Araucanía Lacustre). These are understood as part of the discursive aspect of globalization – the process by which the territory and its population are integrated ever more tightly into the networks of global market society – and considered in conjunction with discourses around Mapuche indigenous identity. Drawing on media-cultural studies, actor network theory, and medium theory, the analysis seeks to advance an ecological concept of communication that does not privilege human consciousness and agency. Communication is argued to be the principle by which space (physical and metaphysical) is configured and connected. Through a discussion of the physical and human geography of the territory it is argued that discourse is mutually immanent with material realities, including human practice and pre-discursive, nonhuman elements (chapter 3). The connection between environmental discourse and Mapuche culture is examined through the stereotype of the ecologically virtuous indigenous subject – a stereotype whose significance is changing as parallel neoliberal multicultural and sustainable development discourses boost the prestige of both Mapuche culture and ecological responsibility, even as the steady expansion of market society undermines both (Chapter 2). A program run by an NGO, funded by the Chilean state, and intended to market the agro-ecological produce of Mapuche small farmers to tourists, provides a concrete case of the intersection of neoliberal multiculturalism with environmental discourse (Chapter 4). The concept of "postmaterialism" is adapted, with a critical edge, in an exploration of the environmental activism and a certain dissatisfaction with modernity among college educated immigrants to the District from Santiago, North America and Europe (chapter 5). The process of globalization, through which Mapuche campesinos come to use environmentalist discourses, involves interactions among old and new information technologies, transportation technologies, and the non-anthropogenic realities of physical space-time and geography (chapter 6). The dissertation concludes with a normative argument about the ethical and epistemological inadequacy of globalizing market society.^

Effects of chronic administration of THC on MDMA-induced physiological, behavioral, and neurochemical alterations

Shen, Erica Yibei — Wed, 22 May 2013 15:20:11 PDT

Most recreational users of 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") also take cannabis, in part because cannabis can reduce the dysphoric symptoms of the ecstasy come-down, such as agitation and insomnia. Although previous animal studies have explored the acute effects of co-administering MDMA and Δ9-tetrahydrocannabinol (THC), the major psychoactive ingredient in cannabis, research on chronic exposure to this drug combination is lacking. The four experiments included in the current dissertation were designed to provide a wide breadth of information on the physiological, behavioral, and neurochemical effects of intermittent MDMA administration combined with daily THC exposure using a dosing regimen designed to reflect a clinically-relevant pattern of human ecstasy and cannabis co-usage. Because ecstasy and cannabis abuse usually starts during human adolescence, drug treatment was administered from postnatal day (PD) 35 to 60 in order to target the period of rat development lasting from approximately mid-adolescence to early adulthood. In addition, the dosing regimen in rats was also chosen to best correlate to patterns of human ecstasy and marijuana use. Drug-treated rats received two subcutaneous (s.c.) injections of 10 mg/kg of (±) MDMA-HCL every fifth day and/or a single daily intraperitoneal (i.p.) injection of 5 mg/kg of THC every day. The twice every fifth day MDMA dosing regimen was designed to simulate the intermittent weekend usage of ecstasy at "rave" parties and the "boosting" behavior (taking additional doses of MDMA in the same session to maintain desired effects) that has been noted in human users. THC was administered daily to simulate heavy cannabis usage in humans, which has been defined to mean using cannabis more than seven times per week. While THC helped to alleviate MDMA-induced anxiety-like, impulsivity-like, and exploratory behavior, co-administration of MDMA and THC additively produced depressive-like behavior and deficits in spatial memory. Furthermore, our experiments provide physiological and neurochemical evidence that helps to explain the behavioral outcomes, specifically as THC failed to protect against MDMA-induced neurotoxicity in the hippocampus, the brain region that is responsible for processing of spatial memory information, in both the SERT binding assay and in SERT autoradiography. Finally, our data suggested that male rats are more susceptible to MDMA-induced damages than females—which has significant implications for assessing the risks of recreational ecstasy and cannabis co-usage in humans. ^

The role of capabilities in innovation adoption decisions

Snyder, Kevin M — Wed, 22 May 2013 15:20:10 PDT

Successful innovations have been assumed by prior literature to ultimately be adopted by all competitors within an industry based on social explanations or economic rationale specific to the efficiency of the innovation. However, capabilities possessed by a firm can enhance or inhibit the adoption based upon their similarity to those used in the innovation. In categorizing a firm's capabilities as complementary, substitutive, or neutralizing to the innovation, this study provides an economic explanation for the role of internal capabilities in adoption decisions. ^ Using a sample of professional football teams adopting the West Coast Offense, I find that capabilities influence the decision process in favor of adopting for organizations with complementary and substitutive capabilities. The role of knowledge from the innovator is highlighted in adopting the innovation, but fails to moderate the relationship between adoption and firm performance. I also illustrate how adopting firms with complementary capabilities outperform those organizations with similar capabilities that elect not to adopt. Finally, I demonstrate that firms with neutralizing capabilities are better off not adopting the innovation based on comparative performance of adopters and non-adopters. The overall results suggest a greater emphasis on internal capabilities of the firm in innovation adoption and reconsideration of theories stating that innovations should be adopted throughout an industry.^

Circle and lines: Complexities of learning in community

Schupack, Sara — Wed, 22 May 2013 15:20:09 PDT

Following is a study that explores learning in community in a fully-integrated, team taught course at a community college in New England. These classes, Learning Communities (LCs) represent rich opportunities for exploring and practicing democratic education. From a theoretical grounding in social learning theories and an exploration into learning and community as active, ongoing phenomena, I present narrative, relational research as enactment. Data from field notes, interviews, focus groups and researcher reflections inform findings and analysis. I represent this as an experience parallel to — not claiming either to mirror or replace — the experiences of the other participants. In these findings, I identify a duality of circles and lines, with circles representing open inquiry, community, collaboration, and democratic discourse. Lines represent reification, hierarchical and binary thinking, and the threat of positivism. Long hours, intense interactions, openness to collaboration, flexible pedagogy, and emerging curriculum all make for complicated relationships that allow for questions, confusions and tensions around what it means to know, who gets to decide, and what are the parameters and epistemologies of academic disciplines. I hope, through this text, to report, celebrate, and participate in these conversations.^

Bridging the gap between autonomous skill learning and task-specific planning

Sen, Shiraj — Wed, 22 May 2013 15:20:07 PDT

Skill acquisition and task specific planning are essential components of any robot system, yet they have long been studied in isolation. This, I contend, is due to the lack of a common representational framework. I present a holistic approach to planning robot behavior, using previously acquired skills to represent control knowledge (and objects) directly, and to use this background knowledge to build plans in the space of control actions. ^ Actions in this framework are closed-loop controllers constructed from combinations of sensors, effectors, and potential functions. I will show how robots can use reinforcement learning techniques to acquire sensorimotor programs. The agent then builds a functional model of its interactions with the world as distributions over the acquired skills. In addition, I present two planning algorithms that can reason about a task using the functional models. These algorithms are then applied to a variety of tasks such as object recognition and object manipulation to achieve its objective on two different robot platforms. ^

Hybrid push: A mechanistic model for initial transcription common to all RNA polymerases

Samanta, Satamita — Wed, 22 May 2013 15:20:06 PDT

The well-studied RNA polymerases fall into two distinct and apparently unrelated classes: the "single subunit" family, represented by bacteriophage T7, mitochondrial, and chloroplast RNA polymerases and the multi-subunit bacterial and eukaryotic enzyme family. All are characterized by a relatively unstable initial phase, exploited as a point of regulation at some promoters, and by a large structural rearrangement associated with the transition to stable elongation. Our previous studies with T7 RNA polymerase have established a specific model for the coupling of hybrid growth to promoter release and to abortive cycling. ^ We now extend these studies to the more complex and structurally unrelated multi-subunit system to show that the fundamental energetics of abortive cycling is common in all RNA polymerases. In my current research, I have studied the role of the RNA-DNA hybrid, sigma factor, and transcription bubble collapse in abortive cycling and backtracking in initially transcribing complexes of E. coli RNA polymerase. To understand the role of the collapse of the transcription bubble in abortive initiation, I have engineered nicks, gaps and mismatch sequences in DNA templates. As in our earlier studies in the T7 system, my new results show that collapse of the downstream end of the transcription bubble decreases the stability of a halted complex. This increases overall turnover, but not necessarily the probability of abortive dissociation during read-through transcription. The results demonstrate clearly that DNA "scrunching" is not the primary driving force of abortive instability. ^ In E. coli RNA polymerase, the σ_3.2 linker initially occupies the RNA exit channel, presenting an impediment to the nascent RNA-DNA hybrid, and displacement of the σ_3.2 linker is thought to weaken promoter contacts, allowing promoter escape. Exploiting mutations in the σ_3.2 linker, GreB as a probe of backtracking, and novel promoter constructs that allow initiation without sigma, we present evidence to support a model, similar to one recently proposed for the single subunit enzymes, in which the pushing of the hybrid against the σ_3.2 linker destabilizes the hybrid (note the analog of the σ_3.2 linker in eukaryotes is the TFIIB B-finger). Thus abortive cycling is a necessary consequence of the common evolutionary need to couple timed promoter release to the energetics of phosphoryl transfer. ^

Software techniques to reduce the energy consumption of low-power devices at the limits of digital abstractions

Salajegheh, Mastooreh Negin — Wed, 22 May 2013 15:20:05 PDT

My thesis explores the effectiveness of software techniques that bend digital abstractions in order to allow embedded systems to do more with less energy. Recent years have witnessed a proliferation of low-power embedded devices with power ranges of few milliwatts to microwatts. The capabilities and size of the embedded systems continue to improve dramatically; however, improvements in battery density and energy harvesting have failed to mimic a Moore's law. Thus, energy remains a formidable bottleneck for low-power embedded systems. ^ Instead of trying to create hardware with ideal energy proportionality, my dissertation evaluates how to use unconventional and probabilistic computing that bends traditional abstractions and interfaces in order to reduce energy consumption while protecting program semantics. My thesis considers four methods that unleash energy otherwise squandered on communication, storage, time keeping, or sensing: 1) CCCP, which provides an energy-efficient storage alternative to local non-volatile storage by relying on cryptographic backscatter radio communication, 2) Half-Wits, which reduces energy consumption by 30% by allowing operation of embedded systems at below-spec supply voltages and implementing NOR flash memory error recovery in firmware rather than strictly in hardware, 3) TARDIS, which exploits the decay properties of SRAM to estimate the duration of a power failure ranging from seconds to several hours depending on hardware parameters, and 4) Nonsensors, which allow operation of analog to digital converters at low voltages without any hardware modifications to the existing circuitry.^

New insights into corruption: Paradoxical effects of approach-orientation for powerholders

Rock, Mindi S — Wed, 22 May 2013 15:20:03 PDT

Does power lead to corruption (Kipnis, 1972), and if so, why? Here, a novel mechanism is proposed for understanding the complex relationship between power and corruption by incorporating recent work on morality (Janoff-Bulman, Sheikh, & Hepp, 2009). By bridging the power, self-regulation, and morality literatures we proposed that powerful individuals, because of their approach tendencies, are oriented more towards moral prescriptions or "shoulds" and thus focus more on moral acts and moral intentions while minimizing the importance of moral proscriptions (neglect pathway). We proposed an alternative path to corruption for powerholders via moral self-regard. Powerholders, because of their approach-based moral focus, would experience an automatic boost of implicit moral self-regard that would license future immorality. In three studies we found suggestive evidence that the approach tendencies of participants primed with power maximized the role of good moral acts and intentions and minimized the impact of moral transgressions, because the individual's monitoring system focused on and valued instances of moral successes rather than moral failures (neglect pathway). We did not find support for the moral self-regard pathway.^

Coaching the self: Identity work(ing) and the self-employed professional

Ruane, Sinead G — Wed, 22 May 2013 15:20:02 PDT

Identity has long been a prolific research interest for organizational scholars. Its popularity can be attributed to the development of post-bureaucratic organizations, where control is no longer achieved through external forms (i.e. rules and procedures), but rather, "softer" mechanisms, such as organizational culture and values. Examining identity therefore becomes crucial for understanding how employees internalize organizational goals to exhibit desired behaviors. While the predominant approach has been to analyze how organizations help shape, control, and regulate member identity, this project calls into question the assumption of organizational employment to explore the micro-processes of identity construction among a growing class of worker in the U.S.: the self-employed professional. ^ This investigation is grounded in the world of personal coaching, an emerging profession organized largely by self-employment. Between 2007–2011, I immersed myself in the "field" of coaching, generating data via ethnographic methods—i.e. participant observation, in-depth interviews, informal interactions—and secondary archival sources. ^ Applying a critical interpretive lens to conceptualize identity not as a "thing" but as an ongoing social accomplishment, the analysis reveals three main insights. First, intense identity working was provoked by tensions and anxiety arising from conflicts, contradictions, and challenges, as informants tried to construct a positive identity as a self-employed professional, while simultaneously performing vital (and mostly unrecognized) identity work for the wider coaching profession. Second, since "doing" identity and material conditions are mutually constitutive, identity efforts can be categorized as having a profitable, proficient, or pragmatic orientation; I contend that this typology is applicable to other self-employed professionals. Third, as a socially negotiated process, identity working is one which recruits many participants—both within and outside of the coaching community. Furthermore, geographically-dispersed members actively regulate and control each other's identities to maintain professional standards, via new organizing forms, like social media. ^ This investigation contributes to knowledge about the nuances of identity working, and linkages between such micro-processes and the wider historical, socio-economic conditions. Extending beyond the coaching profession, the data produced serve as a contextual exemplar for exploring how individuals navigate the restructuring of labor and changing employment relations, which increasingly characterize the "new world of work."^

Effective biosensor arrays using gold nanaoparticle-protein conjugates

Rana, Subinoy — Wed, 22 May 2013 15:20:00 PDT

Developing effective biosensor for proteins, cells, and tissues would enhance the likelihood of early disease detection and treatment. Traditional specificity-based methods are limited by the requirement of prior knowledge of the specific biomarker(s) and high production cost. My research has been focused on developing a rapid and efficient biosensor based on selective interactions using an unbiased array of supramolecular complexes formed between cationic gold nanoparticles and fluorescent proteins. The sensor is capable of discriminating between mammalian cells, as well as healthy and metastatic tissues with significantly small amount of samples, an important requirement for disease diagnosis in clinics. In addition to the cell/tissue state classification, the sensor array is able to identify protein imbalances in undiluted serum, demonstrating the applicability of the sensor array in physiological matrices. Later, I have developed a triple-channel high-throughput sensor to identify chemotherapeutic drug mechanism that would simplify drug discovery. Overall, the sensor array provides a generic tool for bio-profiling, precluding additional processing steps prior to screening and holds great promise for personalized screening of disease states.^

Food-grade nanodispersions for encapsulation, protection and delivery of bioactive food components

Qian, Cheng — Wed, 22 May 2013 15:19:59 PDT

The aim of this thesis was to develop and test novel food-grade nanodispersions, such as nanoemulsions and solid lipid nanoparticles, for the encapsulation, protection and delivery of bioactive lipophilic food components. Initially, the impact of system composition and homogenization conditions on the formation of nanoemulsions using a high pressure homogenizer (microfluidizer) was examined. The mean particle diameter decreased with increasing homogenization pressure and number of passes, with a linear log-log relationship between mean particle diameter and homogenization pressure. Surfactants emulsifiers formed smaller droplets than protein emulsifiers, which was attributed to their ability to rapidly adsorb to the droplet surfaces during homogenization. At low oil phase-to-aqueous phase viscosity ratios, much smaller mean droplet diameters could be achieved for SDS (d ∼ 60 nm) than for β-lactoglobulin ( d ∼ 150 nm). ^ The effectiveness of various biopolymer emulsifiers at forming and stabilizing model beverage emulsions was examined: β-lactoglobulin (BLG); gum arabic (GA); modified starch (MS). Orange oil-in-water nanoemulsions (5% oil) were prepared using high pressure homogenization. Extensive droplet aggregation occurred in BLG-stabilized nanoemulsions around their isoelectric point, at high salt concentrations, and at high temperatures, due to changes in electrostatic and hydrophobic interactions. There was little effect of pH, ionic strength, and temperature on emulsions stabilized by GA or MS, due to strong steric (rather than electrostatic) stabilization. ^ The potential of utilizing oil-in-water (O/W) nanoemulsions stabilized by a globular protein (β-lactoglobulin) for encapsulating and protecting β-carotene was examined. The influence of temperature, pH, ionic strength, and emulsifier type on the physical and chemical stability of β-carotene enriched nanoemulsions was investigated. The rate of color fading due to β-carotene degradation increased with increasing storage temperature (5 to 55 ºC), decreasing pH, and was largely independent of ionic strength (0 to 500 mM of NaCl). β-carotene degradation was considerably slower in β-lactoglobulin-stabilized nanoemulsions than in Tween 20-stabilized ones. The rate of β-carotene degradation decreased upon addition of additional antioxidants. EDTA was found more effective than ascorbic acid, and Coenzyme Q10 was more effective than vitamin E acetate. The utilization of water-soluble and oil-soluble antioxidants in combination (EDTA and vitamin E acetate) was less effective than using them individually. ^ Solid lipid nanoparticles (SLN) were prepared by homogenizing at a temperature (≈ 80°C) exceeding the melting point of the lipid phase (tripalmitin), and then cooling the resulting oil-in-water nanoemulsions to induce lipid droplet crystallization. Blending tripalmitin with low melting point lipids (either medium chain triglycerides or orange oil) prior to homogenization led to a considerable alteration in the phase behavior and stability of SLN. The presence of the carrier oils reduced the crystallization temperature, melting temperature, and melting enthalpy of tripalmitin. ^ The bioaccessibility of β-carotene encapsulated within nanoemulsion-based delivery systems was examined. A non-ionic surfactant (Tween 20) was used as an emulsifier and long chain triglycerides (LCT), medium chain triglycerides (MCT) or orange oil were used as carrier oils. The bioaccessibility of β-carotene was negligible (≈ 0%) in orange oil nanoemulsions because no mixed micelles were formed to solubilize β-carotene, and was relatively low (≈ 2%) in MCT nanoemulsions because the mixed micelles formed were too small to solubilize β-carotene. In contrast, β-carotene bioaccessibility was relatively high (about 66%) in LCT nanoemulsions because the mixed micelles were large enough to solubilize the bioactive molecule. ^ Overall, our results have important implications for the design of effective delivery systems for encapsulation of carotenoids and other lipophilic bioactive components so that they can be incorporated into functional food and beverage products.^

The development of Spanish aspect in the second language classroom: Concept-based pedagogy and dynamic assessment

Polizzi, Marie-Christine — Wed, 22 May 2013 15:19:58 PDT

The main objective of this case-study research is to document the learning and potential development of Spanish aspect by a female multilingual learner of Spanish, Judith, during her second year of study in an SLA classroom context at a university in Northeastern United States over a two semester (one year) period. This research also examines the specific classroom context in which this learner's development was documented. The second objective is therefore to document the extent to which this approach mediated potential grammatical development in Judith, particularly in her conceptual understandings of Spanish aspect. A Vygotskyan-inspired concept-based pedagogy (CBP) (Gal'Perin, 1989, 1992; Negueruela, 2003; Negueruela and Lantolf, 2006; Negueruela, 2008) and dynamic assessment (DA) procedures (Poehner and Lantolf, 2005;, Lantolf & Thorne, 2006; Poehner, 2008), both based on Sociocultural Theory (Vygotsky 1978, 1986) were implemented to teach Spanish to learners. The quality of the new meanings being developed by Judith was documented over time under this particular concept-based teaching context. ^ Data was collected in order to capture the personal histories and orientations to different contexts and activities for this research participant. A combination of insights from Spradley (1980) and Emerson (1995) on ethnographic records was used in order to document the social learning situation taking place in the classroom. It included a combination of artifacts such as field notes, teaching artifacts, tape-recorded interviews, and oral and written discourse from Judith. ^ To analyze how the research participant developed the concept of Spanish aspect (preterit versus imperfect), I used the SCOBA (Schema for Complete Orienting Basis of Action) that was developed by Negueruela (2003) for L2 learning of Spanish. I also used Poehner (2008) and Bloome et al. (2008)'s perspective on data analysis to examine the meaning-making of the L2 learner participant in interaction while she was using the artifacts and interacting with her peers and me, the instructor and investigator. This combination of ethnographic and CBI tools aims at providing a richer picture of this multilingual learner's development over time that would reflect the complexity and dynamic nature of language learning and development (as suggested by Van Lier, 2004). ^

Molecular and population level approaches to understand Taxus metabolism in cell suspension cultures

Patil, Rohan A — Wed, 22 May 2013 15:19:57 PDT

Plant cell culture is an attractive platform technology for production and supply of important plant derived medicinals. A unique characteristic of plant cells is the ability to grow as multicellular aggregates in suspension. The presence of these non-uniform aggregates results in creation of distinct microenvironments, which can induce variations in cellular metabolism (e.g., growth, oxygen consumption and secondary metabolite synthesis). This heterogeneity can lead to unpredictable and suboptimal performance in large scale bioprocesses. One example is the Taxus cell culture system, which produces a widely used chemotherapeutic drug—paclitaxel (Taxol ^®). Despite extensive process engineering efforts which have led to increased yields of paclitaxel, Taxus cells exhibit variability in productivity that is poorly understood. Elicitation of Taxus cultures with methyl jasmonate (MeJA) induces the accumulation of paclitaxel, but to varying extents in culture. A significant negative correlation was observed between paclitaxel level and mean aggregate size of the culture, demonstrating the relevance of measuring, and potentially controlling aggregate size during long term subculture. ^ Understanding the regulation of gene expression can provide rational engineering strategies to control variability and optimize performance of Taxus cell cultures. Biosynthetic pathway gene analyses revealed upregulation of genes upon elicitation with MeJA; results also suggested additional molecular regulatory points outside of the biosynthetic pathway. In order to fully understand Taxus molecular regulation and the relationship to paclitaxel production variability, a transcriptome-wide analysis using next generation sequencing (454 and Illumina) methods was performed. Several pathways outside of paclitaxel biosynthesis were found active upon MeJA elicitation. Global comparison of gene expression amongst cultures accumulating different levels of paclitaxel is being performed to completely understand the interactions amongst the paclitaxel biosynthetic pathway and other complimentary and competing pathways to suggest effective targets for metabolic engineering. This work collectively represents the first molecular studies to understand metabolic regulation in Taxus cell cultures. ^ Apart from inducing paclitaxel biosynthesis, MeJA decreases cell growth in Taxus cell cultures. The MeJA-mediated repression of cell growth was shown to correlate with inhibition of cell cycle progression as evident both at the culture level through flow cytometric analyses and at the transcriptional level by repression of key cell cycle-associated genes. Results from this study provide valuable insight into the mechanisms governing MeJA perception and subsequent events leading to repression of Taxus cell growth.^

Evidence of an infectious asthma phenotype: Chlamydia a driven allergy and airway hyperresponsiveness in pediatric asthma

Patel, Katir K — Wed, 22 May 2013 15:19:57 PDT

Asthma is the most common chronic respiratory disease affecting young children and adults all over the world. An estimated 34.1 million Americans have reported asthma in their lifetime and the disease costs ∼US $56 billion dollars to treat each year. Current treatment is based on a paradigm of asthma as a non-infectious atopic condition whose root cause is inflammation. Chronically administered anti-inflammatory medications, primarily inhaled corticosteroids (ICS), ameliorate asthma symptoms in many patients. However, up to 50% of asthmatics, characterized by neutrophil infiltration, IL-17 secretion and increased risk of fatality are refractory to ICS treatment. Chlamydia pneumoniae , a ubiquitous, obligate intracellular pathogen with an innate propensity to persist and cause chronic infections, along with Mycoplasma pneumoniae have been implicated in the development of chronic, refractory asthma. C. pneumoniae infections are common in infants and young children, often coinciding with the development of early onset asthma in the population. ^ These facts lead the Webley lab to evaluate the carriage of Chlamydia in pediatric respiratory disease patients and the work confirmed that respiratory infections caused by Chlamydia is a significant risk factor in asthma development and live Chlamydia was isolated from the lungs of children with chronic asthma. However, the exact mechanism underlying chlamydial involvement in the disease remained unknown and we believed that a better understanding could shed important light on expanded treatment options and mechanisms of this infectious asthma phenotype. The work presented here provides new insight into how (1) early life chlamydial infection can lead to asthma initiation and exacerbation (2) respiratory chlamydial infection induces cellular and chemical immune responses that support asthmatic inflammation (3) other respiratory pathogens (eg. Mycoplasma) can drive similar immunological responses resulting in significant lung pathology. ^

Development and Characterization of Caspase Activatable GFP and a Family of Fluorescent Reporters

Nicholls, Samantha B — Wed, 22 May 2013 15:19:56 PDT

The cellular process of programmed cell death, or apoptosis, is critical in homeostasis and development. In addition it's misfunction is implicated in an array of disease states from cancer to neurodegeration, making it an attractive pathway for drug targeting. A family of proteases, known as caspases, plays a central role in the apoptotic cascade resulting in the ultimate destruction of the cell. We report a genetically encoded dark-to-bright reporter of caspase activity used in E.coli, mammalian cells, and whole organisms which can be used to monitor apoptosis. This reporter, caspase activatable green fluorescent protein (CA-GFP) consists of GFP fused through a flexible linker containing the caspase-3 and -7 recognition sequence, DEVD, to a hydrophobic peptide derived from the influenza A viral M2 protein. This fusion reporter shows a significant fluorescent response in the presence of active caspase. CA-GFP is unique in its ability to hold GFP in a dark state prior to cleavage by active protease. We investigate the mechanism of quenching, examining the structural characteristics which lead to the inability of the GFP chromophore to mature in the presence of the peptide. In better understanding the mechanism of quenching we can engineer CA-GFP to ultimately be used in transgenic animal models. This requires the development of a palette of protease-activatable fluorescent proteins (PrA-FP) which would enable the monitoring of multiple proteolytic events within a cell or organism in real time. Our development of this palette of reporters, varying in their fluorescence and proteolytic response shows that CA-GFP has the potential to be a powerful tool for the study of the role of apoptosis during development in whole organism models and could be an important tool in understanding the role of individual proteases within the complex biochemical environment in the cell.^

Vehicular ad hoc networks: Interplay of geometry, communications, and traffic

Nekoui, Mohammad — Wed, 22 May 2013 15:19:54 PDT

Vehicular Ad Hoc Networks (VANETs) have been proposed to enhance the safety and efficiency of transportation systems. Such networks hold unique characteristics and fulfill new goals that necessitate their study from a whole new perspective other than what has been the prevailing paradigm for conventional Mobile Ad Hoc Networks (MANETs). The mission of this dissertation is to identify such unique characteristics and propose design strategies for VANETs that target the new system goals. ^ We argue that the road and obstacle geometry are two important factors that should be appropriately addressed when studying the communications throughput of VANETs. To this end we first study the effect of traffic conditions and road geometry on VANET throughput scaling laws. We use graph-theoretic and geometrical concepts to derive the throughput scaling of single roads, downtown grids, and general geometry road systems. ^ Moreover, since vehicular communications are supposed to operate in the high frequency ranges, line-of-sight between communicating vehicles picks up importance in VANETs. We use computational geometry tools to study how the specific geometry of obstacles (such as buildings) affects the capacity of urban area VANETs. ^ Finally, the design goal in MANETs is mostly to enhance the communications metrics (such as throughput and/or delay) of the network, whereas in VANETs, is mainly to improve the safety and efficiency of commute. Yet, better performance in terms of the communications metrics does not necessarily lead into improved safety and efficiency of driving. To this end, the main theme of this dissertation is dedicated to the application-oriented design of VANETs for safety applications. To this end we bring the drivers' application needs to the forefront of our attention and provide an analytic framework for VANET safety application design during both sparse and dense vehicular traffic conditions. We use tools from stochastic geometry to derive the optimal MAC parameters that satisfy the safety requirements of the system and validate our results through NS-2 simulations. Our ultimate goal there is to fill-in the current gap between purely traffic-based studies that fail to account for the non-idealities of communications, and communications-based ones which neglect the application needs of the system.^

NASICs: A 'fabric-centric' approach towards integrated nanosystems

Narayanan, Pritish — Wed, 22 May 2013 15:19:52 PDT

This dissertation addresses the fundamental problem of how to build computing systems for the nanoscale. With CMOS reaching fundamental limits, emerging nanomaterials such as semiconductor nanowires, carbon nanotubes, graphene etc. have been proposed as promising alternatives. However, nanoelectronics research has largely focused on a 'device-first' mindset without adequately addressing system-level capabilities, challenges for integration and scalable assembly. ^ In this dissertation, we propose to develop an integrated nano-fabric, (broadly defined as nanostructures/devices in conjunction with paradigms for assembly, interconnection and circuit styles), as opposed to approaches that focus on MOSFET replacement devices as the ultimate goal. In the 'fabric-centric' mindset, design choices at individual levels are made compatible with the fabric as a whole and minimize challenges for nanomanufacturing while achieving system-level benefits vs. scaled CMOS. ^ We present semiconductor nanowire based nano-fabrics incorporating these fabric-centric principles called NASICs and N³ASICs and discuss how we have taken them from initial design to experimental prototype. Manufacturing challenges are mitigated through careful design choices at multiple levels of abstraction. Regular fabrics with limited customization mitigate overlay alignment requirements. Cross-nanowire FET devices and interconnect are assembled together as part of the uniform regular fabric without the need for arbitrary fine-grain interconnection at the nanoscale, routing or device sizing. Unconventional circuit styles are devised that are compatible with regular fabric layouts and eliminate the requirement for using complementary devices. ^ Core fabric concepts are introduced and validated. Detailed analyses on device-circuit co-design and optimization, cascading, noise and parameter variation are presented. Benchmarking of nanowire processor designs vs. equivalent scaled 16nm CMOS shows up to 22X area, 30X power benefits at comparable performance, and with overlay precision that is achievable with present-day technology. Building on the extensive manufacturing-friendly fabric framework, we present recent experimental efforts and key milestones that have been attained towards realizing a proof-of-concept prototype at dimensions of 30nm and below.^

Techno-economic feasibility study of ammonia plants powered by offshore wind

Morgan, Eric R — Wed, 22 May 2013 15:19:51 PDT

Ammonia production with offshore wind power has the potential to transform energy and fertilizer markets within the United States. The vast offshore wind resource can be converted directly into liquid ammonia using existing technologies. The liquid ammonia can then be transported around the country via rail, truck, barge or pipeline and used as either a fertilizer or a fuel. This thesis reviews the technologies required for all-electric, wind-powered ammonia production and offers a simple design of such a system. Cost models based on the physical equipment necessary to produce ammonia with wind power are developed; offshore wind farm cost models are also developed for near-shore, shallow, wind farms in the United States. The cost models are capable of calculating the capital costs of small industrial-sized ammonia plants coupled with an offshore wind farm. A case study for a utility-tied, all-electric ammonia plant in the Gulf of Maine is used to assess the lifetime economics of such a system. Actual utility grid prices and offshore wind are incorporated into a systems-level simulation of the ammonia plant. The results show that significant utility grid backup is required for an all-electric ammonia plant built with present-day technologies. The levelized cost of one metric ton of ammonia is high relative to ammonia produced with natural gas or coal, but is not as susceptible to spikes in ammonia feedstock prices. A sensitivity analysis shows that the total levelized cost of ammonia is driven in large part by the cost of producing electricity with offshore wind. Major cost reductions are possible for systems that have long lifetimes, low operations and maintenance costs, or for systems that qualify for Renewable Energy Credits.^

Privacy-aware collaboration among untrusted resource constrained devices

Molina-Markham, Andres David — Wed, 22 May 2013 15:19:49 PDT

Individuals are increasingly encouraged to share private information with service providers. Privacy is relaxed to increase the utility of the data for the provider. This dissertation offers an alternative approach in which raw data stay with individuals and only coarse aggregates are sent to analysts. A challenge is the reliance on constrained devices for data collection. This dissertation demonstrates the practicality of this approach by designing and implementing privacy-aware systems that collect information using low-cost or ultra-low-power microcontrollers. Smart meters can generate certified readings suitable for use in a privacy-preserving system every 10s using a Texas Instruments MSP430 microcontroller. CRFIDs—batteryless devices that operate on harvested energy from RF—can generate encrypted sub-aggregates in 17s to contribute to a privacy-preserving aggregation system that does not rely on a trusted aggregator. A secure communication channel for CRFID tags via untrusted relays achieves a throughput of 18Kbps.^

Measuring proton spin polarizabilities with polarized compton scattering

Martel, Philippe Paul — Wed, 22 May 2013 15:19:47 PDT

Polarized nuclear Compton scattering on a proton target provides a test of low energy QCD. The beam-target asymmetries of a circularly polarized Bremsstrahlung photon beam on a transversely polarized butanol target (Σ₂_x) and on a longitudinally polarized butanol target (Σ₂_z), and the beam asymmetry of a linearly polarized Bremsstrahlung beam on an unpolarized hydrogen target (Σ₃) are sensitive to the proton spin polarizabilities, third order terms in the energy expansion of the Compton scattering amplitude. This experiment consisted of the Σ₂_x measurement, both just below and above two-pion threshold.^

RecA dynamics & the SOS response in Escherichia coli: Cellular limitation of inducing filaments

Massoni, Shawn Christopher — Wed, 22 May 2013 15:19:46 PDT

During the course of normal DNA replication, replication forks are constantly encountering "housekeeping" types of routine damage to the DNA template that may cause the forks to stall or collapse. One product of this fork collapse is the induction of the SOS response, a coordinated global response to help pause the growth and replication of a cell while DNA damage is addressed and repaired. In E. coli, this response is activated by the formation of ssDNA, to which the RecA protein binds and forms a nucleoprotein filament, which acts as the activator for autocleavage of the LexA transcriptional repressor, which normally represses expression of SOS genes. Damage responses are crucial to maintaining genomic integrity, and are therefore essential to all forms of life, and this type of regulatory system is highly conserved. However, cells have mechanisms for tightly regulating induction of these responses, and can often repair routine damage to their chromosomes without the need to induce SOS. This is chiefly evidenced by the observation that more than 20% of cells in a population have RecA filaments, but less than 1% are induced for SOS. How cells make this decision to induce SOS is the subject of this work. ^ This dissertation describes three projects aimed at examining molecular mechanisms by which cells regulate RecA filaments, and therefore the decision to induce the SOS response. The first examines the disparity between the formation of RecA filaments, as evidenced by RecA-GFP foci, and the induction of SOS in the absence of damage, using a psulA-gfp reporter system. It is shown that there are three independent factors that repress SOS expression in undamaged E. coli cells. These are radA, the amount of recA in the cell, and in some circumstances recX. The first two limit SOS in wild type cells in the absence of external damage, while the third is an additional factor required in xthA mutants, likely due to the fact there are more RecA loading events in these mutants. These factors are thought to change the character and reduce the half-life and persistence of RecA filaments in the cell. ^ The second project shows that suppression of SOS through the use of recA4162 and uvrD303 mutants is substrate and situation-specific. This specificity is demonstrated by the fact that, while both recA4162 and uvrD303 can suppress SOS in the SOS constitutive mutant recA730, recA4162 can only suppress SOS when the signal occurs at replication forks and not at any other place on the chromosome, while uvrD303 appears to suppress SOS with less specificity, and can suppress after UV (shown previously), at induced DSBs, and other places not directly at the replication fork. Here mutants of different replication factors are used that uncouple the replisome and induce SOS to a high degree. ^ The third project determines the factors necessary for loading RecA filaments at the replication fork versus other locations on the chromosome when SOS is induced in the absence of damage, and helps elucidate further mechanisms for induction of SOS at these substrates. It is shown that the sbcB and recJ exonucleases assist in inappropriate RecA filament formation by substrate processing exclusively at replication forks, but not other substrates, likely through mechanisms that are reliant on the activities of the RecA loading factors RecBCD and RecFOR.^

A novel approach for stable, cell-type restricted knockdown of gene expression in C. elegans

Maher, Kathryn N — Wed, 22 May 2013 15:19:45 PDT

Removal of protein activity by genetic mutation or pharmacological inhibition has been used extensively to understand the normal function of a protein. However, null mutations eliminate gene function in all cells and pharmacological agents can diffuse through tissues to have similar global effects that can obscure the physiological function of a protein. This is a particular problem when studying proteins that function in many cell types or that have different cell-specific activities. The most direct strategy to study the function of a protein is to reduce or eliminate its activity only in specific cell types, rather than in all cells of an organism. The idea of targeting gene knockdown to specific cell types or to individual cells is not new and many strategies aim to do just this. However, these strategies result in variable knockdown efficiencies and can have silencing effects in neighboring cells and therefore knockdown is never cell-specific. ^ We developed a novel method to knock down the expression of any gene and to restrict this knockdown to specific cell types in C. elegans. In this method we replaced endogenous genes with single copy integrated transgenes containing an engineered sequence tag that introduces premature stop codons (PTCs) into transgene mRNA. This tag causes the natural stop codon to be recognized as a PTC by the host's nonsense-mediated decay (NMD) machinery and does not disrupt gene function. In NMD-competent animals, a PTC-containing transgene is degraded and in NMD-defective animals, a PTC-containing transgene is expressed. Therefore, the expression of PTC-containing transgenes can be controlled by cell-specific activation of NMD. Using this technique, we replaced two endogenous genes with PTC-containing transgenes and directed degradation of their mRNA to specific cell types by restoring NMD activity in these cells. The single copy transgenes were expressed at levels comparable to the endogenous genes and were knocked down to ∼10% of endogenous by NMD, resulting in both global and cell-specific null-like phenotypes. This knockdown strategy can be used to cell-specifically knock down essentially any gene in the C. elegans genome and should provide new insights into understanding protein function.^

Characterization of self-assembled functional polymeric nanostructures: I. magnetic nanostructures from metallopolymers II. Zwitterionic polymer vesicles in ionic liquid

Maddikeri, Raghavendra Raj — Wed, 22 May 2013 15:19:44 PDT

Two diverse projects illustrate the application of various materials characterization techniques to investigate the structure and properties of nanostructured functional materials formed in both bulk as well as in solutions. In the first project, ordered magnetic nanostructures were formed within polymer matrix by novel metallopolymers. The novel metal-functionalized block copolymers (BCPs) enabled the confinement of cobalt metal ions within nanostructured BCP domains, which upon simple heat treatment resulted in room temperature ferromagnetic (RTFM) materials. On the contrary, cobalt functionalized homopolymer having similar chemical structure and higher loading of metal-ion are unstructured and exhibited superparamagnetic (SPM) behavior at room temperature. Based on a series of detailed investigations, using various materials characterization techniques, it was hypothesized that the SPM cobalt particles within BCP microdomains exhibited a collective behavior due to increased dipolar interactions between them under the nanoconfinement of cylindrical domains in BCP, resulting in RTFM behavior. On contrary, the same SPM cobalt particles formed within homopolymer, without any confinement exhibited SPM behavior either due to lack of interactions or random interactions between them. ^ To further support this hypothesis, a series of BCPs were prepared in which the BCP morphology was varied between the cylindrical, lamellar, and inverted cylindrical phases and their magnetic properties were compared. All these BCPs, which are nanostructured, exhibited RTFM behavior, further supporting the proposed hypothesis. Different dimensionality or degree of nanoconfinement in BCP morphologies affected the magnetization reversal processes in these BCPs, yielding different macroscopic magnetic properties. Most strongly constrained cylindrical morphology has shown best magnetic properties (highest coercivity) among other BCP morphologies. Inverted cylindrical morphology, in which a 3-D matrix is confined between the non-magnetic cylinders, had second highest and lamellar morphology with least confinement among BCPs, exhibited lowest coercivity. ^ The proposed hypothesis was further tested by systematically varying the dipolar interactions between the SPM cobalt nanoparticles by reducing the density of cobalt within the cylindrical domains and varying the dimensions of the cylindrical domains (i.e. diameter). A series of novel ferrocene-cobalt containing block copolymers were developed and cobalt density within the cylindrical domains of BCP was varied by changing the chemical composition of the metal functionalized block. Further, the diameter of the cylindrical domains was varied by varying the molecular weight of the cobalt-containing BCPs. These studies allowed us to understand the fundamental correlations between the self-assembled nanostructures and their macroscopic magnetic properties. ^ In the second part of the thesis, a novel amphiphilic block copolymer (ABC), composed of a hydrophilic zwitterionic block and a hydrophobic PS block, was synthesized by ROMP. The formation of zwitterionic vesicles in an ionic liquid, as well as in PBS buffer, was confirmed by TEM and DLS characterization. The dispersion of vesicles within ionic liquid enabled the usage of conventional, room temperature TEM to visualize them in their solution state. This technique of materials characterization could be extended for the visualization of other hydrophilic soft matter.^

An archaeology of improvement in rural New England: Capitalism, landscape change, and rural life in the early 19th century

Lewis, Quentin — Wed, 22 May 2013 15:19:43 PDT

This dissertation examines the materiality of agricultural Improvement in the Connecticut River Valley of Massachusetts. Improvement was a social movement with a history in Europe, and which largely operated to rationalize agriculture when it appeared in New England in the early 19th century. Alongside this modernization, Improvement also served to re-shape rural landscapes in keeping with particular social and economic processes of capitalism. This was because Improvement emerged at a time of great social instability in rural Massachusetts, and served to ameliorate the growing tensions between urban and rural socio-economic life. Utilizing both archaeological and documentary data, I deploy a dialectical method that situates landscapes as materializations of larger social processes, properly analyzed through a process of abstraction. Using this method, I explore two landscapes. First, I examine the literature written by the Improvers, particularly the journal New England Farmer, published after 1822. I investigate keywords in the journal to reveal the symbolic landscape articulated by the Improvers, and show that they envisioned a homogeneous New England landscape that was populated by free, White laborers, contrary to the demographic and social history of the region. The second landscape is the built environment of the E.H. and Anna Williams house in Deerfield, Massachusetts. I explore the materiality of the Williams house and its relationship to Improvement in two ways. First, I examine how the Williamses' management of manure was integrated with practices of capitalist farming, and how proper manure management was seen to arrest rural New England's perceived economic and social decline. Secondly, I examine the trash scatters excavated from the Williams yard to reveal continuities and discontinuities with the Improvers' emphasis on clean, ordered spaces. The Williamses actively manipulated space by enhancing the size of the front yard, and moving work activities behind this visible area. This ameliorated the tensions inherent in Improvement between visibility and productivity, and is reflected in the changing distribution of trash at the site. I conclude by suggesting that archaeological studies of rural life take moments of landscape change like Improvement into account, as a way of countering historical narratives of rural timelessness.^

Determination of arsenic in water by potentially portable methodology

Li, Chengbei — Wed, 22 May 2013 15:19:43 PDT

Arsenic contamination in groundwater is a worldwide problem. The existing portable field test kits can not provide accurate results when the arsenic concentration is around 10 µg L^-1 or lower. This research first was focused on the development and validation of methods in which portable instrumentation, such as electrochemistry instruments or quartz crystal microbalances, could be used to accurately determine arsenic concentrations in water even when the concentration is below 10 µg L^-1. A modified anodic stripping voltammetry (ASV) and cathodic stripping voltammetry (CSV) method with measurement at a microarray electrode manufactured by TraceDetect Inc. was developed. When the ASV method with a gold electrode was applied for real water analysis, the detection limit of arsenite was 2.2 µg L^-1, and for arsenate was 0.13 µg L^-1. In the CSV method the more commonly used hanging mercury drop electrode was replaced with a mercury film array electrode. Under the optimum condition, this method had a detection limit for arsenite of 0.58 µg L^-1 and for arsenate of 2.7 µg L^-1. A method for the determination of arsenic using a quartz crystal microbalance was developed in which the crystal surface was modified in situ by dithiolthreitol, an arsenite-selective ingand. The method was applied to real water sample analysis with a limit of 0.6 µg L^-1. The second was concerned with an investigation of the kinetics of the reactions that are the basis of several currently available field test kits (as exemplified by the Hach Kit) using inductively coupled plasma mass spectrometry (ICP-MS) with the goal of improving the performance of the test kit. The time for arsine gas reaches to the maximum concentration in the headspace of the vessel was about 60 min without continuous stirring and only 20% of arsenic was absorbed on the test strip. To speed up the arsine generation, continuous stirring condition can be applied. It also made more arsine absorbed on the test strip. The SEM study proves the structure of the darker colored compound. For the lighter colored compounds, the information is not enough to make a conclusion.^

Multiscale modeling of human addiction: A computational hypothesis for allostasis and healing

Levy, Yariv Z — Wed, 22 May 2013 15:19:42 PDT

This dissertation presents a computational multiscale framework for predicting behavioral tendencies related to human addiction. The research encompasses three main contributions. The first contribution presents a formal, heuristic, and exploratory framework to conduct interdisciplinary investigations about the neuropsychological, cognitive, behavioral, and recovery constituents of addiction. The second contribution proposes a computational framework to account for real-life recoveries that are not dependent on pharmaceutical, clinical, and counseling support. This exploration relies upon a combination of current biological beliefs together with unorthodox rehabilitation practices, such as meditation, and proposes a conjecture regarding possible cognitive mechanisms involved in the recovery process. Further elaboration of this investigation leads on to the third contribution, which introduces a computational hypothesis for exploring the allostatic theory of addiction. A person engaging in drug consumption is likely to encounter mood deterioration and eventually to suffer the loss of a reasonable functional state (e.g., experience depression). The allostatic theory describes how the consumption of abusive substances modifies the brain's reward system by means of two mechanisms which aim to viably maintain the functional state of an addict. The first mechanism is initiated in the reward system itself, whereas the second might originate in the endocrine system or elsewhere. The proposed computational hypothesis indicates that the first mechanism can explain the functional stabilization of the addict, whereas the second mechanism is a candidate for a source of possible recovery. ^ The formal arguments presented in this dissertation are illustrated by simulations which delineate archetypal patterns of human behavior toward drug consumption: escalation of use and influence of conventional and alternative rehabilitation treatments. Results obtained from this computational framework encourage an integrative approach to drug rehabilitation therapies which combine conventional therapies with alternative practices to achieve higher rates of consumption cessation and lower rates of relapse.^

Shared heritage: An anthropological theory and methodology for assessing, enhancing, and communicating a future-oriented social ethic of heritage protection

Labrador, Angela M — Wed, 22 May 2013 15:19:41 PDT

A common narrative in the late twentieth-early twenty-first centuries is that historic rural landscapes and cultural practices are in danger of disappearing in the face of modern development pressures. However, efforts to preserve rural landscapes have dichotomized natural and cultural resources and tended to "freeze" these resources in time. They have essentialized the character of both "rural" and "developed" and ignored the dynamic natural and cultural processes that produce them. In this dissertation I outline an agenda for critical and applied heritage research that reframes heritage as a transformative social practice in order to move beyond the hegemonic treatment of heritage as the objects of cultural property. I propose an anthropological theory of shared heritage: a culturally mediated ethical practice that references the past in order to intervene in alienating processes of the present to secure a recognizable future for practitioners and prospective beneficiaries. More specifically, I develop (1) an ethical framework for shared heritage practice that values social tolerance and future security, (2) a model for the critical assessment of a heritage protection strategy's potential for supporting a shared heritage ethic, and (3) a methodology for scholars, heritage advocates, and community leaders to realistically enact shared heritage. I document two case studies of rural residents implementing heritage protection strategies in the face of suburban and tourism development in Hadley, Massachusetts, and Eleuthera, Bahamas, respectively. I engage with these case studies at three distinct levels: (1) locating and critiquing the potential for a shared heritage ethics in the attempts to preserve private agricultural land in Hadley; (2) developing and applying a community-based heritage inventory assessment in Hadley; and (3) modeling an internet-based communications system for supporting shared heritage development in Eleuthera. Taken together, this dissertation offers an anthropological model for documenting and analyzing the discursive and material productions of cultural identities and landscapes inherent in heritage resource protection and a set of methods that heritage professionals and practitioners can apply to cultivate shared heritage ethics. ^

Determining detailed reaction kinetics for nitrogen- and oxygen-containing fuels

Labbe, Nicole Jeanne — Wed, 22 May 2013 15:19:40 PDT

With the emergence of new biorenewable transportation fuels, the role of heteroatoms in combustion has increased tremendously. While petroleum-based fuels are primarily hydrocarbons, many biorenewable fuels contain heteroatoms such as oxygen and nitrogen, introducing new challenges associated with toxic emissions. A fundamental understanding of the chemical kinetics of combustion of these heteroatomic fuels is necessary to elucidate the pathways by which these toxic emissions are formed and may be achieved through the development of combustion models. Reaction sets, the core of these combustion models, may be assembled for individual fuels through a balance of employing vetted rate constants from prior publications, quantum chemistry calculations, and rate constant estimations. For accuracy, reaction sets should be tested against experimental combustion studies such as low-pressure flame experiments using molecular-beam mass spectrometry (MBMS) or chemiluminescence and high-pressure shock-tube experiments. ^ This dissertation presents the development of a new reaction set to describe gas-phase combustion chemistry of fuels containing only hydrogen, carbon, oxygen, and nitrogen. The foundation of this model was a reaction set to describe combustion of ammonia flames. This reaction set contains only H/N/O chemistry for simplicity. The new reaction set was tested against a pyrolysis shock-tube study, as well as 12 MBMS flame experiments under a variety of conditions, including different mixtures of fuels and oxidizers (NH₃, N₂O, H₂, NO, O₂), fuel equivalence ratios (lean to rich), pressures, and concentrations of diluent gas. Additionally, the base H/N/O mechanism was expanded to include carbon chemistry and was tested against flames of dimethylamine, ethylamine, and a methane/ammonia mixture. ^ This reaction set was employed to study heterocyclic biofuels including a fuel-rich flame of tetrahydropyran, the monoether analogue to cyclohexane and the basic ring in cellulose. Additionally, the model was used in a study of morpholine, a 6-membered ring with both ether and amine functionalities, testing the model against fuel-rich flame studies using both MBMS and chemiluminescence techniques and high-pressure shock-tube studies for both oxidation and pyrolysis at elevated temperatures and pressures. Lastly, the model was used to study the combustion of hypergolic rocket fuels, specifically monomethyl hydrazine and tetramethylethyldiamine with red fuming nitric acid.^

Pattern formation in floating sheets

King, Hunter — Wed, 22 May 2013 15:19:39 PDT

This thesis presents a study of two basic modes of deformation of a thin sheet: wrinkling and crumpling, viewed primarily in the context of an elastic sheet confined by capillary forces on a drop of liquid. ^ First, it provides a brief conceptual background in the relevant physics of thin sheet mechanics and capillarity and introduces the general principles of wrinkling and crumpling. ^ The problem of confining a circular sheet on an increasingly curved spherical drop is presented as a vehicle to explore these principles. At finite curvature, the sheet is seen to wrinkle around its outer edge. At large confinement, characteristic features of crumpling gradually dominate the pattern. The experimental observations in both regimes are analyzed separately. ^ Analysis of images of the sheet in the wrinkled regime yield data for the number and length of the wrinkled zone, as a function of the experimental control parameter, the pressure. The length of the wrinkles is correctly described by a far-from-threshold theory, which describes a limiting regime in thin-sheet mechanics, distinguished by high 'bendability'. The validity of this theory is verified by the data for highly bendable, ultrathin sheets for the first time. The theory is based on the assumption that the wrinkles completely relax compressive stresses and therefore preserve the cylindrical symmetry of the stress field. ^ The emergence of crumpling from the wrinkled shape is explored via evolution of visible features in the sheet as well as gaussian curvature measurements obtained by analyzing height maps from optical profilometry. The emergence of several length scales, increasing asymmetry in curvature distribution, the failure of wrinkle extent prediction and formation of d-cones associated with crumpling are all measured to locate the transition to a crumpled state. The value of gaussian curvature at the center of the sheet appears to follow the cylindrically symmetric prediction over the whole range of the experiment, suggesting that the onset of crumpling events does not affect the global shape of the sheet. ^ Finally, analogous wrinkling and crumpling behavior of particle-laden interfaces is discussed. The spontaneous formation of conical defects in a curved 2D crystal is compared to the crumpling of a sheet on a drop, and insight from thin sheet mechanics is applied to the mysterious wrinkling of particle rafts. Some future directions for measuring wrinkling of sheets on negative curvature surfaces and deformations of fluid interfaces are proposed.^

Feronia: A malectin-like domain-containing receptor kinase in Arabidopsis thaliana insights into polarized cell growth, pollen tube - Pistil interactions, and sugar signaling

Kita, Daniel W — Wed, 22 May 2013 15:19:39 PDT

RAC/ROPs are a unique group of RAS-related monomeric G proteins (small G proteins) that constitute the sole family of Rho GTPases in plants. RAC/ROPs, like their counterpart Rho GTPases from mammalian and fungal systems, can interconvert between an active GTP and an inactive GDP bound state. These powerful signaling molecules lie upstream in many diverse signal transduction pathways. Their controlled regulation is critical to overall plant fitness, growth, development, and responses to abiotic and biotic stress. RAC/ROP activation is regulated by guanine nucleotide exchange factors (GEFs). The work in this dissertation initiated from the characterization of the expression and functions of RopGEF1, a broadly expressed GEF that localizes to the sites of root hair formation and regulates polarized cell growth. The focus of this dissertation is on FERONIA (FER), an upstream regulator of RopGEF1 that was initially identified as a RopGEF1 interacting protein in a yeast two-hybrid screen. FERONIA (FER) was found to regulate RAC/ROP-mediated signal transduction for auxin-regulated root hair growth and a number of other auxin-dependent responses, consistent with RAC/ROPs playing an important role in auxin signaling. ^ In flowering plants, pollen tubes deliver sperm to fertilize the female gametophytes located inside the ovules. Once a pollen tube enters it subsequently bursts releasing its sperm, which enables fertilization. Mechanisms are in place to coordinate tube rupture as well as repel late arriving pollen tubes from an already visited ovule. In this way not yet visited ovules have higher chances of fertilization and fertilized ovules avoid polyspermy. In this work, FER is demonstrated to mediate NADPH oxidase-dependent reactive oxygen species production required for pollen tube rupture. In addition, FER is also required for de-esterified pectin deposition outside the female gametophyte, which correlates with the ability of ovules to divert late arriving pollen tubes. Furthermore, the extracellular domain of FER, which contains predicted carbohydrate-binding malectin-like domains, interacts directly with pectin. This finding establishes FER as a cell wall-binding receptor kinase in plants and illuminates unprecedented mechanisms of pollen tube reception. ^ The presence of carbohydrate binding motifs in the extracellular domain of FER and its direct interaction with pectin prompted my investigation of its role in sugar sensing and signaling pathways. My work shows that feronia (fer) mutants are hypersensitive to sucrose, while over-expressing FER suppresses sugar signaling. Moreover, fer mutants accumulate elevated levels of starch, which demonstrates defects in their distribution of carbohydrate resources in source (sugar producing) and sink (sugar consuming) tissues. The fer mutants also display sucrose-induced cell wall defects, alterations to cellular morphology, and enhanced production of the stress-associated pigment, anthocyanin. These results suggest that FER functions as a negative regulator of sugar sensing and signaling pathways. Additional support for this model stems from the finding that FER is highly expressed in tissues involved in sucrose transport and its expression is stimulated by sucrose. Furthermore, and consistent with the hormone abscisic acid being part of the overall sugar sensing network, fer mutant seedlings are hypersensitive to ABA and display enhanced ABA response gene expression. Taken together, the data presented in this dissertation reveal the regulation of widespread and essential plant functions including RAC/ROP signaling, pollen tube reception, cell wall integrity, and sugar signaling by a single cell surface receptor kinase.^

Continuity in the face of change: Mashantucket Pequot plant use from 1675--1800 A.D.

Kasper, Kimberly C — Wed, 22 May 2013 15:19:38 PDT

Thisiinvestigation focuses on the decision making relative to plants by Native Americans on one of the oldest and most continuously occupied reservations in the United States, the Mashantucket Pequot Nation. Within an agency framework, I explore the directions in which decision making about plants were changing from 1675-1800 A.D. I evaluate plant macroremains, specifically progagules (seeds), recovered from ten archaeological sites and the historical record from the Mashantucket Pequot Reservation, located in southeastern Connecticut. I demonstrate how decision making about plants related to food and medicinal practices during the Colonial Period were characterized by heterarchical choices that allowed the Mashantucket Pequot to retain their sense of economic and cultural autonomy from their colonizers. This type of problem-directed agency analysis will aid in placing Indigenous individuals and communities into the contexts of colonization as more active participants in their own past, and as long-term stewards of the environment. More specifically, this dissertation shows that even as small a space as the Mashantucket Pequot Reservation is a rich testimony to the 11,000-year history, and continues to provide important information about how households and communities (re)conceptualize their socio-natural worlds under the most severe constraints.^

Critical Rhetoric in the Age of Neuroscience

Ingram, Brett — Wed, 22 May 2013 15:19:37 PDT

Although there has been an outpouring of scholarship on the "rhetorical body" in the last two decades, nearly all analyzes and critiques discourses about the body. Very little work in contemporary rhetorical studies addresses the ways in which rhetoric affects and alters the central nervous system, and thereby exerts influence at a level of subjective experience prior to cognitive and linguistic apprehension. Recent neuroscientific research into affect, identity, and decision-making echoes many of the claims made by ancient rhetoricians: namely, that rhetorical activity is corporeally transformative, and that the material transformations wrought by rhetoric have profound implications for subjects' capacity to engage in critical thought and agential judgment. This study demonstrates that emotional political rhetoric is physiologically addictive, that the brain and body can make decisions independently of the will of the thinking subject, and that symbolic violence can physically reconfigure the neural networks that make critical cognition possible. ^ As public culture and discourse becomes increasingly imagistic, non-rational, and emotionally charged, critics must develop theoretical resources capable of recognizing and responding to new varieties of constitutive phenomena. Neuroscience can supplement traditional rhetorical criticism by offering insight into the physiological processes by which destructive ideas become self-sustaining, and it can help critics devise more sophisticated rhetorical approaches to the task of promoting social healing. To advance this conversation, this dissertation outlines a critical neurorhetorical theory that is attuned to the Sophistic and Burkean rhetorical tradition, informed by contemporary neuroscience, and responsive to the unique cultural and social conditions of the 21^st century.^

Plant mechanisms associated with variations in freezing tolerance of cool-season grasses

Hoffman, Lindsey — Wed, 22 May 2013 15:19:36 PDT

Cool-season grasses are adapted to seasonal decreases in temperature that in some areas reach well below freezing; however, despite being able to acclimate to such conditions, plants may still be susceptible to winter injury. Specifically, direct low temperature kill caused by freezing temperatures has been identified as a major component of winter injury across many plant species including turfgrasses. Although cool-season species are the grasses of choice for Northern climatic regions, a high degree of variability in freezing tolerance exists among cool-season turfgrasses. Tolerance to freezing temperatures is influenced by both the capacity of plants to cold acclimate prior to the onset of winter and the ability to withstand decreases in freezing tolerance (deacclimation) during winter and early spring months. Therefore, the objectives of my dissertation research were to (i) evaluate the physiological and biochemical modifications occurring during the cold acclimation and deacclimation process using cool-season turfgrasses that vary in freezing tolerance and (ii) determine the effects of differences in cold acclimation capacity and deacclimation sensitivity on overall freezing tolerance of cool-season grasses. ^ Differences in freezing tolerance among the cool-season grasses evaluated were associated with variations in cold acclimation capacity and deacclimation resistance. Overall, the accumulation of protective compounds such as carbohydrates along with changes in lipid composition during cold acclimation may represent critical mechanisms to help lower cellular freezing point and improve cellular stability of cool-season grasses at freezing temperatures. In addition, decreases in freezing tolerance in response to mild warming events were minimized in plants that maintained higher levels of specific carbohydrates such as fructans. Additionally, strategies such as wilt-based irrigation may be used as a tool to enhance cold acclimation and maximize freezing tolerance of cool-season grasses. Taken together, the mechanisms identified in these studies may serve as selection criteria for the development of cool-season grasses with enhanced freezing tolerance.^

Intellectual Constellations in the Postsocialist Era: Four Essays

Gu, Li — Wed, 22 May 2013 15:19:35 PDT

In an attempt to facilitate the task of charting a path toward a radically different future, a future without the bourgeois intellectual property regime (IPR), this dissertation searches back in history by examining China's loss of socialism. ^ The guiding question can be formulated thus: Why did the People's Republic of China give up its socialist mode of intellectual production only to embrace the bourgeois intellectual property regime (IPR), which had been subjected to devastating criticism by progressive scholars in the West since mid-1990s? Situating this rupture of China's approach to intellectual production within the ongoing process of postsocialist structuration in the wake of the waning Chinese socialism, this dissertation focuses on Chinese intellectuals as social mediators and locates the traces of the loss of socialism in various cultural productions during the postsocialist era.^

Synthesis and Solution-Driven Assembly of Functional Polythiophene Derivatives

Hammer, Brenton A. G — Wed, 22 May 2013 15:19:35 PDT

Conjugated polymers are of interest in organic photovoltaics (OPVs) for the benefits of their low cost, ease of processing, and flexible design. OPV device performance greatly depends on the morphology of the donor (conjugated polymer) and acceptor (fullerene, CdSe, etc.) materials, which should ideally promote efficient exciton formation, dissociation, and charge transport to the respective electrodes. One potentially ideal active layer morphology would consist of an interpenetrating, bicontinuous network of donor and acceptor materials, having domain sizes of ∼10 nm (i.e., on the order of the exciton diffusion length). Such morphologies can be achieved through annealing processes (thermal or solvent) of the donor/acceptor blend, or the use of pre-formed, highly crystalline fibril nanowires of the conjugated nanowires. ^ This thesis outlines the design of functional polythiophene copolymers with the ability to form novel assemblies through tailored functionalities. Amphiphilic P3HT-b-poly(3-(triethyleneglycol)thiophene) (P3TEGT) diblock copolymers were synthesized that were capable of microphase separating based on the difference in polarity between the blocks. We targeted P3HT-b-P3TEGT thin-film morphologies, where we could orient [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) (electron acceptor) in the polar P3TEGT domain, to allow P3HT to form pristine crystal domains. Thermal annealing P3HT-b-P3TEGT diblock copolymers led to microphase separation, as characterized by atomic force microscopy (AFM) and small-angle x-ray scattering (SAXS), and OPV devices were fabricated and characterized using P3HT-b-P3TEGT/PCBM blends. ^ P3HT-based diblock copolymers that had hydroxyl- and amine- functionalities were synthesized in an effort to utilize their nucleophilic nature for further functionalization. These copolymers underwent a solvent-induced crystallization that provided a P3HT nanowire decorated with the hydroxyl/amine functionalities on the fibril exterior. Previously, cross-linking mechanisms for polythiophenes had occurred in thin films upon thermal annealing or exposure to radiation, with little control over the crystallinity of the polymer. We were able to utilize fibrils formed from our functional diblock copolymers to covalently cross-link the crystalline structures by reacting with diisocyanates. This led to the formation of robust fibrils that had not previously been reported, that maintained photophysical and electronic properties to the unmodified nanowires. These nucleophilic fibrils were reacted with a bis-diisocyanate functionalized fullerene derivative to yield stabilized p-type/n-type nanowires. This process led to robust p-type/n-type fibrils that displayed photoluminescence quenching and high charge transfer characteristics that were not observed for p-type/n-type blends. ^ In an effort to simplify the fibril cross-linking, we designed a P3HT-based diblock copolymer that had thioacetate functionalities, which were deprotected and underwent an oxidative cross-linking process. These polymers formed nanowires by solvent induced precipitation, and upon deprotection of the thioacetate groups by reaction with dimethyl amine, experienced oxidative cross-linking to achieve robust fibrils. This provided a novel system in that the polymer was able to cross-links itself, and the cross-linking process was found to be reversible by reduction chemistry.^

Determining structure and function in nanomaterial biocomposites

Griffin, David M — Wed, 22 May 2013 15:19:34 PDT

Polymeric biomaterials represent the leading technologies available today for the repair of tissue damage and for targeted drug delivery. Perhaps the most valuable aspect of polymer-based systems is the extent to which their physical properties (e.g. elasticity, porosity, etc.) can be controlled and tuned by regulating experimental parameters during their synthesis. Biomaterial performance can be improved further still by including supplementary components resulting in a composite material. Synergetic interactions between the constituents of composite materials often results in bulk physical properties that are substantially more than the sum of individual parts. Through understanding and exploiting these sympathetic relationships, novel biocomposites can be developed which exhibit improved efficacy and biocompatibility. ^ Here we report on the synthesis strategies and characterization of novel biocomposites from our laboratory. We look specifically at hydrogel composites containing a physically-associated network of Pluronic^® block copolymer along with a calcium-phosphate mineral component. Rheological results show that composites containing an in situ deposited mineral exhibit a significantly higher elastic modulus than composites of similar composition formed by conventional means. Moreover, analysis of the calcium-phosphate phase of in situ composites revealed that system parameters such as acidity play an integral role in determining the size and stability of the resultant mineral and subsequently the materials' expected in vivo performance. ^ Changes to the structure in Pluronic^®/calcium-phosphate composite hydrogels during dehydration was investigated to provide a look into the mechanisms involved in composite formation. Small angle X-ray scattering analysis of these systems shows that hydrogen bonding interactions between phosphate ions and the polyethylene oxide (PEO) polymer block significantly impact the nanoscale structure and long-range order contained in these materials. Phosphate groups are preferentially sequestered into the PEO phase in the gel and overall structural changes can be directly related to the average number of hydrogen bonds each phosphate ion experiences. Our results indicate that by understanding how mineralization occurs in simplified systems we may be able to provide insight into the complex mechanisms involved in natural tissue formation. Moreover, we show that by utilizing novel synthesis routes we are able to manufacture new biomaterials with desirable and tunable physical properties.^

The parsing and interpretation of comparatives: More than meets the eye

Grant, Margaret Ann — Wed, 22 May 2013 15:19:33 PDT

This dissertation examines comparative constructions, both in terms of their representation in syntax and semantics and in terms of the way these representations are built and interpreted incrementally during sentence processing. While there has been extensive investigation of comparatives in the syntax and semantics literature (see Bresnan, 1973; von Stechow, 1984; Heim, 1985; Kennedy, 1999, among others), there has been little work on how comparatives are processed (although see Fults and Phillips, 2004; Wellwood et al., 2009 for work on so-called comparative illusions). In the first half of the dissertation, I address issues that are primarily syntactic in nature; in the second half, I address issues that are primarily at the semantic and pragmatic levels. In Chapter 2, I examine the basic syntax of English comparatives and readers' expectations for the structure of comparatives during parsing. I present evidence from eye movements during reading to argue that a curious pattern of acceptability in comparatives (observed by Osborne, 2009) arises from processing factors rather than the grammar. Chapter 3 provides evidence from self-paced reading that, in contrast to what has been shown for other more widely studied structures, in comparative clauses subject gaps are more difficult to process than object gaps. Some potential accounts for this asymmetry between comparatives and other structures are discussed, and in Chapter 4, I argue for a grammar-based account of the subject gap penalty. Chapters 5 and 6 investigate questions in the semantics/pragmatics and semantic processing of comparatives. In Chapter 5, I introduce a previously unstudied type of comparative, which I call subset comparatives, and investigate their appropriate formal representation. In addition to their theoretical interest, subset comparatives can provide insight into comprehenders' expectations regarding the relationship between the two sets of entities involved in comparatives. Evidence from eye movement studies suggests that readers have an initial preference for contrast, or disjointness, between sets in comparatives. Chapter 6 investigates issues in the comparison of pluralities during on-line sentence processing, again as studied through eye movements during reading. This chapter provides evidence that, when comparing sets, comparisons that involve degrees along an adjectival scale involve complexity beyond that involved in comparing sets in terms of their cardinalities. The results of my experimental studies on comparatives are related to broader issues in linguistics and psycholinguistics, such as the sources of well-formedness (or ill-formedness) in language, the representation of linguistically described sets in language processing, and the interaction between levels of information (syntactic, semantic, and conceptual/world knowledge) in comprehension.^

Enhanced detection strategies accomplished through metal binding and miniature mass spectrometry

Graichen, Adam — Wed, 22 May 2013 15:19:31 PDT

A multiplexed method for performing MS/MS on multiple ions simultaneously in a miniature rectilinear ion trap (RIT) mass spectrometer has been developed. This method uses an ion encoding procedure that relies on the mass bias that exists when ions are externally injected into an RIT operated with only a single phase RF applied to one pair of electrodes. The ion injection profile under such conditions ions is Gaussian-like over a wide range of RF amplitudes, or low mass cutoff (LMCO) values, during ion accumulation. We show that this distribution is related to ion m/z, and is likely caused by ions having an optimal range of pseudo-potential well depths for efficient trapping. Based on this observation, precursor ion intensity changes between two different injection LMCO values can be predicted, and these ion intensity changes are found to be carried through to their corresponding product ions, enabling multiplexed MS/MS spectra to be deconvoluted. ^ The gas-phase reactions of a series of coordinatively unsaturated [Ni(L)_n]^y+ complexes, where L is a nitrogen-containing ligand, with chemical warfare agent (CWA) simulants in a miniature rectilinear ion trap mass spectrometer were investigated as part of a new approach to detect CWA. Results show that the metal complex ions can react with low concentrations of several CWA simulants, including dipropyl sulfide (simulant for mustard gas), acetonitrile (simulant for the nerve agent tabun), and diethyl phosphite (simulant for nerve agents sarin, soman, tabun, and VX), thereby providing a sensitive means of detecting these compounds. The [Ni(L)_n]²⁺ complexes are found to be particularly reactive with the simulants of mustard gas and tabun, allowing their detection at low parts-per-billion (ppb) levels. These detection limits are well below the median lethal doses for these CWAs, which indicates the applicability of this new approach, and are about two orders of magnitude lower than electron ionization detection limits on the same mass spectrometer. The use of coordinatively unsaturated metal complexes as reagent ions offers the possibility of further tuning the ion-molecule chemistry so that desired compounds can be detected selectively or at even lower concentrations. ^ Mass spectrometry has become a tool for studying noncovalently bound complexes. Specifically, electrospray ionization mass spectrometry (ESI-MS) has found increasing use for the determination of affinity (K_a) or dissociation (K_d) constants. Direct measurement of the equilibrium components by ESI-MS is the most straightforward approach for determining binding equilibrium constants, but this approach is prone to error and has some inherent limitations. Transferring complexes from solution to the gas phase may perturb the equilibrium concentrations and/or different ionization efficiencies may cause the resulting ion signals not to reflect actual solution concentrations. Furthermore, ESI only works under a limited range of solvent conditions (i.e. low ionic strengths), which limits the broad applicability of this approach. We propose an approach based on covalent labeling in the context of metal-catalyzed oxidation (MCO) reactions that, when combined with MS, overcomes such limitations when determining metal-ligand binding constants. The MCO-MS approach will provide concurrent information regarding metal binding site and metal-protein binding affinity. Optimization of the MCO reaction through isotopic mass tags will permit enhanced identification of modified residues. Application of this method to study the affinity and binding interactions of other divalent metals with β2m are likely to provide insight into the specificity of copper for causing β2m amyloid formation.^

Design, synthesis and characterization of polymeric nanostructures for protein sensing and delivery

Gonzalez-Toro, Daniella Cristina — Wed, 22 May 2013 15:19:30 PDT

Increasing motivation for the development of nanotechnology with applications in sensing, nanotheranostics, combinatorial therapy and drug/protein delivery have brought a broad spectrum of multifunctional polymeric materials. With interest in obtaining more efficient methods for fast and accurate diagnostics, nanostructures able to rapidly obtain large sets of data for analyte sensing are necessary. Likewise, interests in, not only obtaining accurate diagnostics, but also being able to concurrently and accurately provide therapy has inspired us to develop such technologies. ^ We particularly focus on understanding the assembly and disassembly processes of polymeric nanostructures in response to biologically relevant stimuli. We are interested in mimicking natural sensing events and take advantage of the differential binding affinity of a set of receptors to generate analyte-specific patterns to use as sensors. Receptors developed in our laboratories have demonstrated impressive recognition capabilities for proteins. When a set of polyelectrolytes and surfactants with different hydrophobic and electronic properties, as well as the guest molecule (transducer) with different characteristics, are combined, fluorescence patterns for proteins can be generated. Creating patterns using protein-induced disassembly not only provides the opportunity to have a new method for sensing analytes that are not electronically complementary to the fluorescent transducers, but also reduces the synthetic complexity even further, since these are assembled from its components noncovalently. ^ A versatile and efficient delivery vehicle should have a tunable particle size, provide protection and stability to the cargo to prevent premature release before approaching the target site and should provide ease of cargo incorporation strategies. This ease of incorporation becomes more challenging when we are talking about incorporating molecules with different characteristics. Here we demostrate the versatility of self-crosslinked polymeric nanogels on the incorporation of lipophilic small molecules on its interior and hydrophilic proteins at the surface. Also, different approaches of protein incorporation can be obtained using these polymeric nanogels, which provide differences in protein release and cell internalization. These technologies were found to be potential candidates for applications such as nanotheranostics, combinatorial therapy and protein delivery.^

Data combination from multiple sources under measurement error

Gasca-Aragon, Hugo — Wed, 22 May 2013 15:19:29 PDT

Regulatory Agencies are responsible for monitoring the performance of particular measurement communities. In order to achieve their objectives, they sponsor Intercomparison exercises between the members of these communities. ^ The Intercomparison Exercise Program for Organic Contaminants in the Marine Environment is an ongoing NIST/NOAA program. It was started in 1986 and there have been 19 studies to date. Using this data as a motivation we review the theory and practices applied to its analysis. ^ It is a common practice to apply some kind of filter the comparison study data. These filters go from outliers detection and exclusion to exclusion of the entire data from a participant when its measurements are very "different". When the measurements are not so "different" the usual assumption is that the laboratories are unbiased then the simple mean, the weighted mean or the one way random effects model are applied to obtain estimates of the true value. ^ Instead we explore methods to analyze these data under weaker assumptions and apply them to some of the available data. More specifically we explore estimation of models assessing the laboratories performance and way to use those fitted models in estimating a consensus value for new study material. This is done in various ways starting with models that allow a separate bias for each lab with each compound at each point in time and then considering generalizations of that. This is done first by exploiting models where, for a particular compound, the bias may be shared over labs or over time and then by modeling systematic biases (which depend on the concentration) by combining data from different labs. As seen in the analyses, the latter models may be more realistic. ^ Due to uncertainty in the certified reference material analyzing systematic biases leads to a measurement error in linear regression problem. This work has two differences from the standard work in this area. First, it allows heterogeneity in the material being delivered to the lab, whether it be control or study material. Secondly, we make use of Fieller's method for estimation which has not been used in the context before, although others have suggested it. One challenge in using Fieller's method is that explicit expressions for the variance and covariance of the sample variance and covariance of independent but non-identically distributed random variables are needed. These are developed. ^ Simulations are used to compare the performance of moment/Wald, Fieller and bootstrap methods for getting confidence intervals for the slope in the measurement model. These suggest that the Fieller's method performs better than the bootstrap technique. We also explore four estimators for the variance of the error in the equation in this context and determine that the estimator based on the modified squared residuals outperforms the others. ^ Homogeneity is a desirable property in control and study samples. Special experiments with nested designs must be conducted for homogeneity analysis and assessment purposes. However, simulation shows that heterogeneity has low impact on the performance of the studied estimators. This work shows that a biased but consistent estimator for the heterogeneity variance can be obtained from the current experimental design.^

Concept-based teaching and Spanish modality in Heritage language learners: A Vygotskyan approach

Garcia Frazier, Elena — Wed, 22 May 2013 15:19:28 PDT

This study analyzed how six Heritage language learners at the university level gained conscious awareness and control of the concept of modality as revealed in student verbalizations (Vygotsky, 1998) throughout five different written communicative events. This work took place in the only course designed for Heritage language learners at a large public suburban university in the Northeast part of the United States. ^ Grammatical simplification in bilingual speakers is due to incomplete acquisition of Spanish, attrition or loss of an underused linguistic system (Lynch, 1999; Martínez Mira, 2009a, 2009b; Mikulski, 2010b; Montrul, 2007; Ocampo, 1990; Silva-Corvalán, 1990, 1994a, 1994b, 2003; Studerus, 1995). The result of the process of simplification is reduction or loss of forms and/or meanings. ^ In this work, I investigated in which ways Gal'perin's (1989) systemic-theoretical organized instruction promoted awareness, control and internalization of the concept of modality in three sets of data: definition, discourse and verbalization (Negueruela, 2003). In addition, I examined how the concept of modality emerged and proceeded. ^ By focusing students' attention in Negueruela's (2003) Concept of Mood in Spanish orienting chart in a top down fashion, students were able to strengthen their theoretical understanding in practical activity while still accessing empirical knowledge, and eventually generalizing its use in new contexts across nominal, adjectival and adverbial clauses. ^ At the definition level, Gal'perin's Systemic-theoretical instruction promoted emergence and progress of their conceptual understanding from perceptual to semantic. At the discourse level, students' theoretically based semantic understanding had a positive impact as revealed in student's discourse progress throughout tasks. At the verbalization level, semantic, abstract and systematic verbalizations showed students' emergence of awareness of the interrelated categories of modality. The conceptual category of anticipation was appropriately verbalized and contextualized 68% of the time. The absence of quality verbalizations referring to a specific conceptual category in some students lead me to conclude that students did not fully understand the meaning of some conceptual categories. On the contrary, their presence in any of the tasks showed emergence of conceptual meaning(s) in appropriate contexts, further appropriate recontextualization may provide full awareness and control.^

Surviving domestic tensions: Existential uncertainty in New World African diasporic women's literature

Fraser, Denia M — Wed, 22 May 2013 15:19:27 PDT

This dissertation pinpoints imaginative patterns that people within the diaspora have used and now use to navigate highly untenable domestic circumstances. In focusing on this aspect of psychological survival, we can trace domestic behaviors back to existential questions that trouble individuals in the New World African Diaspora: questions of self-knowledge amidst internalized racism, questions that seek to realign one's history and future after migration, questions about the colonial and personal mother. These types of questions which frame my examination of Toni Morrison's The Bluest Eye, Loida Maritza Pérez's Geographies of Home and Andrea Levy's Small Island, direct us toward psychic and physical tensions that preoccupy Black Women writers and their characters. ^ In the second chapter of this dissertation, my textual analysis of The Bluest Eye engages with how Morrison orders an existential logic of a young girl's development through her experience with private violation and public racial violence. In the third chapter, I argue that Loida Maritza Pérez's Geographies of Home is an examination of the psychologies of a mother and her daughters, as revealed by the omniscient narrator, which discloses the complex interplay of illusion/reality, inward turn/outward turn, belief/unbelief which characterizes the immigrant's uncertain survival. In my fourth chapter, Andrea Levy's Small Island, two Jamaicans, Hortense and Gilbert grow up in early twentieth century, colonial Jamaica and later immigrate to WWII England. Through these two characters, Levy demonstrates how the dynamic of the existential uncertainty inherent in the colonial relationship consistently holds in tension two important concepts: help and humiliation. ^ Ultimately, I assert that recognizing existential uncertainty in the New World African Diaspora not only highlights the acute sense of unpredictability that plagues African American, Caribbean and Black British individuals, but points to a genealogy of psychic oppression that persists for these people groups. This dissertation calls for a witnessing of a family's traumatic history in a way that envisions the future healing and reconciliation of psychic wounds. This project expands scholarship on the harrowing psychic genealogies that link African-American, Caribbean and Black British domestic environments and establishes a relevant existential vocabulary for diasporic experiences of violence, wounding and self-questioning.^

Accurate and robust mechanical modeling of proteins

Fox, Naomi K — Wed, 22 May 2013 15:19:26 PDT

Through their motion, proteins perform essential functions in the living cell. Although we cannot observe protein motion directly, over 68,000 crystal structures are freely available from the Protein Data Bank. Computational protein rigidity analysis systems leverage this data, building a mechanical model from atoms and pairwise interactions determined from a static 3D structure. The rigid and flexible components of the model are then calculated with a pebble game algorithm, predicting a protein's flexibility with much more computational efficiency than physical simulation. In prior work with rigidity analysis systems, the available modeling options were hard-coded, and evaluation was limited to case studies. ^ The focus of this thesis is improving accuracy and robustness of rigidity analysis systems. The first contribution is in new approaches to mechanical modeling of noncovalent interactions, namely hydrogen bonds and hydrophobic interactions. Unlike covalent bonds, the behavior of these interactions varies with their energies. I systematically investigate energy-refined modeling of these interactions. Included in this is a method to assign a score to a predicted cluster decomposition, adapted from the B-cubed score from information retrieval. Another contribution of this thesis is in new approaches to measuring the robustness of rigidity analysis results. The protein's fold is held in place by weak, noncovalent interactions, known to break and form during natural fluctuations. Rigidity analysis has been conventionally performed on only a single snapshot, rather than on an entire trajectory, and no information was made available on the sensitivity of the clusters to variations in the interaction network. I propose an approach to measure the robustness of rigidity results, by studying how detrimental the loss of a single interaction may be to a cluster's rigidity. The accompanying study shows that, when present, highly critical interactions are concentrated around the active site, indicating that nature has designed a very versatile system for transitioning between unique conformations. ^ Over the course of this thesis, we develop the KINARI library for experimenting with extensions to rigidity analysis. The modular design of the software allows for easy extensions and tool development. A specific feature is the inclusion of several modeling options, allowing more freedom in exploring biological hypotheses and future benchmarking experiments.^

Investigations of surface-tension effects due to small-scale complex boundaries

Feng, Jiansheng — Wed, 22 May 2013 15:19:25 PDT

In this Ph.D. dissertation, we have investigated some important surface-tension phenomena including capillarity, wetting, and wicking. We mainly focus on the geometric aspects of these problems, and to learn about how structures affect properties. . ^ In the first project (Chapter 2), we used numerical simulations and experiments to study the meniscus of a fluid confined in capillaries with complicated cross-sectional geometries. In the simulations, we computed the three-dimensional shapes of the menisci formed in polygonal and star-shaped capillaries with sharp or rounded corners. Height variations across the menisci were used to quantify the effect of surface tension. Analytical solutions were derived for all the cases where the cross-sectional geometry was a regular polygon or a regular star-shape. Power indices that characterize the effects of corner rounding were extracted from simulation results. These findings can serve as guide for fabrications of unconventional three-dimensional structures in Capillary Force Lithography experiments. Experimental demonstrations of the working principle was also performed. Although quantitative matching between simulation and experimental results was not achieved due to the limitation of material properties, clear qualitative trends were observed and interesting three-dimensional nano-structures were produced. ^ A second project (Chapter 3) focused on developing techniques to produce three-dimensional hierarchically structured superhydrophobic surfaces with high aspect ratios. We experimented with two different high-throughput electron-beam-lithography processes featuring single and dual electron-beam exposures. After a surface modification procedure with a hydrophobic silane, the structured surfaces exhibited two distinct superhydrophobic behaviors—high and low adhesion. While both types of superhydrophobic surfaces exhibited very high (approximately 160° water advancing contact angles, the water receding contact angles on these two different types of surfaces differed by about 50° ∼ 60°, with the low-adhesion surfaces at about 120° ∼ 130° and the high-adhesion surfaces at about 70° ∼ 80°. Characterizations of both the microscopic structures and macroscopic wetting properties of these product surfaces allowed us to pinpoint the structural features responsible for specific wetting properties. It is found that the advancing contact angle was mainly determined by the primary structures while the receding contact angle is largely affected by the side-wall slope of the secondary features. This study established a platform for further exploration of the structure aspects of surface wettability. ^ In the third and final project (Chapter 4), we demonstrated a new type of microfluidic channel that enable asymmetric wicking of wetting fluids based on structure-induced direction-dependent surface-tension effect. By decorating the side-walls of open microfluidic channels with tilted fins, we were able to experimentally demonstrate preferential wicking behaviors of various IPA-water mixtures with a range of contact angles in these channels. A simplified 2D model was established to explain the wicking asymmetry, and a complete 3D model was developed to provide more accurate quantitative predictions. The design principles developed in this study provide an additional scheme for controlling the spreading of fluids. ^ The research presented in this dissertation spreads out across a wide range of physical phenomena (wicking, wetting, and capillarity), and involves a number of computational and experimental techniques, yet all of these projects are intrinsically united under a common theme: we want to better understand how simple fluids respond to small-scale complex surface structures as manifestations of surface-tension effects. We hope our findings can serve as building blocks for a larger scale endeavor of scientific research and engineering development. After all, the pursue of knowledge is most meaningful if the results improve the well-being of the society and the advancement of humanity. (Abstract shortened by UMI.)^

Aesthetic experience in the culture of professionalism, 1890--1925

Fortier, Eric — Wed, 22 May 2013 15:19:25 PDT

This dissertation elaborates an American pragmatist aesthetic tradition that anticipates recent "turns" in cultural studies to aesthetics and affect. Although a commitment to the nondiscursive ends of art is most explicitly voiced by pragmatist philosophers, I emphasize fiction writers who likewise argue that what most matters in art is our immediately felt, inarticulate experience of an artwork rather than anything we can say about it. These writers celebrated the nondiscursive character of aesthetic experience as a critique of an emerging culture of professionalism that, they felt, reduced aesthetic experience to linguistic meaning and thereby consolidated the authority of the professional middle class over rural, poor, and immigrant Americans. ^ While these writers were critics of the culture of professionalism, they were also its products and participants, and they registered their dual commitments in images of bifurcated consciousness, most famous of which is W.E.B. Du Bois's concept of a racial "double-consciousness" endemic to the African American. Here double consciousness serves as a metaphor for the tension between professional discourse and nondiscursive aesthetic experience. Each chapter explores a different valence of this metaphor, illustrating it through analysis of a fictional work. The protagonists in these works are encountered at crises in their professional careers, and their dual commitments to discourse and nondiscourse are dramatized in their encounters with artworks. ^ Chapter 1 argues that a dual commitment to the analytic and the vague in William James's The Principles of Psychology and Henry James's "The Figure in the Carpet" reflects these brothers' ambivalence toward a late-nineteenth-century aestheticism that insisted on art's "uselessness." Chapter 2 demonstrates that Harold Frederic's The Damnation of Theron Ware negotiates a double consciousness prompted by the nineteenth-century "warfare" between science and theology. Chapter 3 examines the role that a racialized difference between "white" words and "black" music assumed during the Jim Crow era, as demonstrated in James Weldon Johnson's The Autobiography of an Ex-Coloured Man. Chapter 4 demonstrates that Willa Cather's The Song of the Lark mitigates a tension between art's functions as escapism and as propaganda by sketching a model of American cultural nationalism rooted in "primitive" nondiscursivity.^

Regulation and action of SKP2 and RhoA in cell and tumor models: Investigation into the molecular mechanisms responsible for the aggressive phenotype of triple-negative breast cancer

Fagan-Solis, Katerina D — Wed, 22 May 2013 15:19:23 PDT

Breast cancer tops the list of new cancer cases and is predicted to be the second leading cause of cancer deaths in women in 2012. The primary objective of the present study was to provide insights into the molecular mechanisms underlying the aggressive growth and metastasis of triple-negative and basal-like breast cancers. To study increased growth and invasive behavior in triple-negative and basal-like breast cancers we utilize both an interesting and relevant cell culture model and examination of human tissue. ^ S-phase kinase-associated protein 2 (SKP2) plays an important role in cell cycle regulation by targeting p27 for degradation. The cyclin-dependent kinase (CDK) inhibitor p27 regulates G1/S transition by binding cyclin/CDK complexes and abrogating its activity. By targeting p27 for degradation, SKP2 frees the complexes needed to progress into the S phase of the cell cycle. Evaluation of SKP2 expression in TMX2-28 revealed significantly higher levels than in other breast cancer cell lines. Despite the high levels of SKP2 expression, p27 protein was not reduced. However, levels of the Serine 10 phosphorylated form of p27 (pSer10p27), which has been associated with increased proliferation rates, was found to be increased. Furthermore, suppression of SKP2 completely eliminated the pSer10p27 and slowed cycle progression confirming the role of SKP2 in the aggressive growth of TMX2-28 cells. ^ Assessment of mRNA from 30 frozen human breast cancers demonstrated that SKP2 is more highly expressed in ER&agr;-negative and basal-like breast cancers. Immunohistochemical analysis of 188 breast cancers and 50 benign reduction mammoplasty tissues confirmed that SKP2 is more highly expressed in ER&agr;-negative breast cancers and for the first time demonstrated that triple-negative breast cancers are more likely to overexpress SKP2 than are non-triple-negative, but still ER&agr;-negative, tumors. In contrast to some previous reports, we did not observe an inverse relationship between SKP2 and p27 expression. Only 11% of tumors expressed high SKP2 and low p27, while 32% of tumors had high SKP2 and high p27. Although no significant relationship between SKP2 and p27 expression was observed in human breast cancers, a significant positive relationship was discovered between SKP2 and pSer10p27. Furthermore, high levels of SKP2 and pSer10p27 were observed significantly more often in ER&agr;-negative and triple negative breast tumors than in ER&agr;-positive breast cancers. Based on these results and those of the cell culture experiments showing complete elimination of pSer10p27 after suppression of SKP2 it appears that levels of pSer10p27 may be a better indicator of SKP2-dependent p27 degradation than are levels of p27. Therefore, that inhibiting SKP2 in triple-negative breast cancers expressing high levels of both SKP2 and pSer10p27 regardless of p27 levels may be a valid therapeutic approach. ^ We determined that TMX2-28 lack MMP-1 mRNA, and MMP-2/MMP-9 protein expression; each of which is important in protease-dependent invasion. Furthermore, TMX2-28 cells have low expression of other genes key to protease-dependent invasion including Slug, Zeb 1, Zeb 2, Vimentin, Fibronectin and N-cadherin. RhoA is a member of the Rho superfamily of GTPases that acts as a molecular switch to control signal transduction and is critical to the amoeboid invasion mechanism. TMX2-28 cells have high expression of protease-independent invasion genes such as RhoA, ROCK 1, ROCK 2, and E-cadherin. Finally, treating TMX2-28 cells with a RhoA pathway inhibitor or an shRNA targeting RhoA significantly reduces their invasiveness. These data suggest that TMX2-28 cells use a RhoA-dependent, proteolytic-independent invasion mechanism. Collectively, the data presented here demonstrate the roles of SKP2 and RhoA in triple-negative and basal-like breast cancers, making both genes, as well as their pathways, desirable therapeutic targets. (Abstract shortened by UMI.)^

Gapping in Farsi: A crosslinguistic investigation

Farudi, Annahita — Wed, 22 May 2013 15:19:23 PDT

This dissertation explores a longstanding challenge in work on gapping through the empirical lens of gapping in Farsi (the Tehrani variant of Modern Persian). While gapping has much in common with more uncontroversial elliptical constructions such as VPE and sluicing, it also differs from ellipsis in ways that accounts combining TP or CP coordination and constituent deletion fail to explain. Johnson (1994/2004, 2009), and extensions of Johnson's work in Coppock (2001) and Lin (2000,2001), among others, propose a solution to this dilemma for gapping in English that relies on LOW COORDINATION and, consequently, on the assumption that VP, or υP, is the verbal constituent targeted in gapping. I argue that the same kind of solution cannot be extended to Farsi because there is not evidence of low coordination structures in gapping and, crucially, VPE does not exist independently in the langauge. It is shown that while gapping in Farsi exhibits the same core characteristics that distinguish it from ellipsis in English and other languages (restriction to coordinations, forward only directionality), it does not exhibit those that motivate the low-coordination structure. I propose an alternative MOVEMENT PLUS DELETION account that addresses the first set of differences while retaining (i) TP, as opposed to VP, coordination and (ii) ellipsis as the source of the gap. This is achieved by designating the coordinate head itself the syntactic licensor, and by requiring that the gapped TP must move to a specifier position of the coordinate head in order for ellipsis to be licensed via an agreement relationship between it and the licensing head. The necessity of movement in establishing the ellipsis-licensing agreement relationship is argued to account for the contrast between the acceptability of gapping in embedded clauses and the ungrammaticality of gapping inside islands. Thus this account, while it derives the gap from ellipsis, also has affinities with accounts, particularly that of Johnson (1994/2004), which seek to explain the distinctive properties of gapping by invoking movement. In addition to contributing a study of gapping in Farsi, in which gapping has not been previously studied, to the cross-linguistic data on gapping, a major empirical contribution of this work is the finding that the restriction against embedded gapping observed in English is likely not a definitional property of gapping across languages.^

Conductivity of gold nanoparticle thin films and magnetoresistance of metallic thin films embedded with periodic arrays of cobalt nanoparticles

Dickert, Stefan — Wed, 22 May 2013 15:19:22 PDT

Thin films of 7 nm gold nanoparticles were fabricated via a direct write electron beam exposure. The electrons caused the nanoparticles to stick to the substrate and the unexposed areas were rinsed off. After the lift off, the films were annealed. This caused Ostwald ripening. Electrical and structural properties were studied. It was found that the initial film thickness is the crucial factor of the post annealing properties. In case of films thinner than 50 nm, it was found that the particles ripen to form insulating islands hundreds of nanometers in size and seperated from each other. If the film thickness is increased beyond 50 nm, the ripening causes the islands to grow so much, that at least one percolating pathway for charge transport is formed. Metallic conductivity was observed in a wide temperature range (2–350 K). It is possible to create films that display hopping conductivity, if the initial film thickness is at approximately 50 nm. ^ In a second experiment, polystyrene—block-poly(4-vinylpyridine) (PS-P4VP) diblock copolymer was used to create a hexagonal lattice of cobalt nanoparticles. The size scale of the particles was about 12–15 nm with a 25–30 nm separation between them. This artificially arranged array of magnetic "impurities" was covered with a thin metallic film. Copper or palladium were used and the thickness was varied between 13–40 nm. It was found that these nanoengineered films show thermal hysteresis in resistance versus temperature measurements, the shape of which can be manipulated by applying a magnetic field. The effect was more pronounced in the cobalt-copper samples. Further, magnetoresistance measurements showed oscillations as a function of applied field and temperature. Again, the effects shown in the cobalt-copper samples were significantly more pronounced.^

Ecology and conservation of the montane forest avian community in northeastern North America

DeLuca, William V — Wed, 22 May 2013 15:19:21 PDT

Montane forests provide habitat for unique assemblages of flora and fauna that contribute significantly to a region's biodiversity. Previous work indicates that montane forest ecosystems are exceedingly vulnerable to a host of anthropogenic stressors including climate change, atmospheric deposition, and recreation, to name a few. Montane forests and other high elevation ecosystems are considered to be among the first and most severely impacted by climate change. It is therefore, imperative to evaluate anthropogenic impacts on montane ecosystems and maintain reliable monitoring methods that are capable of tracking potential shifts in the distribution of species dependent on these systems. I surveyed birds at various distances from hiking trails in the White Mountain National Forest from 2006–2009 to determine whether existing monitoring programs, all of which are based on trail-centered surveys, are accurately reflecting bird abundance, abundance stability and recruitment. Contrary to previous studies, I found that recreational trails generally did not alter estimates of abundance, recruitment, abundance stability, and detection probability for five species of birds considered to be indicators of montane forest ecosystem integrity in northeastern North America. Therefore, trail-based monitoring programs for montane birds appear to accurately reflect dynamics of bird communities undisturbed by hiking trails. These conclusions were supported by my finding that the daily nest survival of a montane spruce-fir indicator species, blackpoll warbler (Steophaga striata), did not vary as a function of distance from trail. ^ I then used data from the White Mountain National Forest's montane bird monitoring program from 1994 through 2009 to assess potential shifts in the elevational distribution of montane birds in conjunction with documented habitat shifts in the region. My results provide evidence that low elevation forest birds have expanded their upper elevational boundary while high elevation birds have expanded their lower elevation boundary. These results highlight the complicated relationship between habitat, climate, and other anthropogenic stressors such as atmospheric deposition and that even in the face of climate change other stressors may be playing a significant role in shifts of species distributions. ^ Understanding how climate affects the reproductive ecology of montane organisms is an important step toward unraveling the potential mechanisms by which climate change will alter the distribution of these species. I used blackpoll warbler breeding data from the Green Mountains, VT from 1994 to 2003 to determine if temporal variation in climate influenced blackpoll nesting initiation and found that years with warm Mays and typical precipitation lead to earlier nest initiation. I also examined the effect of spatial variation in climate on blackpoll reproductive ecology and demography. I found a gradient in habitat quality associated with the spatial variation in climate along an elevation gradient. Blackpolls were less abundant, younger, had lower pairing success, lower daily nest survival, higher nest predator occupancy, and lower fecundity at lower elevations. The climatic conditions at these lower elevations represent the climatic conditions predicted to encompass increasingly larger portions of montane areas. Collectively, these findings contribute to filling in a dearth of knowledge regarding management and an understanding of how species dependent on montane ecosystems are responding to climate change. ^

Investigation of the orientation dependence on chiroptical properties of single molecules

Cyphersmith, Austin J — Wed, 22 May 2013 15:19:20 PDT

Optical activity is the defining property of chiral materials that is essential for characterization in biology, chemistry, and physics. While a substantial body of research has provided a strong theoretical framework of the origin of optical activity, we still know very little by way of experiment about an individual molecule's contribution to the bulk optical activity. The chiroptical response of a single molecule can depend on molecular orientation and local molecular environment, information which is lost in ensemble averaging. ^ This thesis focuses on establishing methods for a priori determination of chiral molecule orientations and refining measurements to probe the chiroptical response of a single molecule using a generalization of well-known defocused emission pattern imaging. Recent experiments probing the chiroptical response of single helicene dimer molecules offer new insight into the relationship between local molecular environment and coupling between chiral moieties. New experiments, such as probing the chiroptical response of an achiral, non-centrosymmetric molecular systems and polarization resolved spectral measurements which probe the Davydov splitting of coupled chromophore systems offer promising new avenues for understanding the connection between the polarization properties of single molecules and the ensemble.^

Resilient polymer networks via thiol-norbornene chemistry: Mechanical and adhesive properties

Cui, Jun — Wed, 22 May 2013 15:19:19 PDT

Hydrogels, a class of materials composed of polymer networks swollen with large amounts of water, have gained increasing attention in a range of fields, from tissue engineering to food science. However, synthetic hydrogels are known to be brittle and have poor mechanical properties, including low extension ratios and fracture toughnesses. It has been a great challenge to develop synthetic hydrogels with improved mechanical properties and correlate with their network composition. In this dissertation we developed two robust well-defined synthetic hydrogel systems by two simple strategies—thiol-norbornene chemistry and ring opening metathesis polymerization (ROMP). The swelling and mechanical properties were systematically characterized and correlated with their network structures. ^ The PEG/PDMS hydrogels synthesized by the simple, efficient, photo-initiated thiol-norbornene chemistry have improved mechanical properties. By manipulating the volume fractions of the PEG and PDMS, a large range of water content (54%–97%) was achieved. The Young's modulus (E) was significantly improved by increasing the volume fraction of PDMS in the hydrogel, and the Voigt and Reuss models were used to quantify the relationship between the volume fraction and E. In addition, increasing the volume fraction and molecular weight of the PDMS led to tougher hydrogels with G_c more than 100 J/m². Furthermore, a high resilience (more than 97%) was maintained across the entire range of strains, regardless of the composition of the PEG/PDMS hydrogels. ^ Controlled polymerization provides another method to synthesize gels with improved mechanical performance. The properties of the ROMP-based gels were tuned by varying the initial molar ratio of the monomer to cross-linker from 7.5% to 20%. The mechanical properties of the gels were characterized via the cavitation rheology technique (CRT), which demonstrated a transition from reversible to irreversible deformation with the increase of the molar ratio. By combining CRT and contact mechanics, E and G_c for these gels were quantified. As the amount of the cross-linker increased, E increased while G_c slightly decreased. ^ Soft tissues with hierarchical structures share similar properties as synthetic hydrogels. The study of their mechanical properties would provide useful information in designing synthetic hydrogels with novel network structures. Eye lens was chosen in this study. The anisotropic mechanical properties of bovine eye lenses were measured using CRT over a range of length scales. E of the nucleus and cortex of the lens were determined, as approximately 11.8 and 0.8 kPa, respectively, on macroscopic length scales. We also measured the mechanical properties of the lens on a length scale of a single cell, suggesting that the stiffness significantly decreased from that in the bulk measurements for both the nucleus and cortex. In addition, during the growth of the cavity anisotropic propagation in the cortex was observed, while in the nucleus, the propagation was isotropic. We further explored the elasticity of the cavity deformation, showing both elastic and inelastic deformation occurred in the nucleus with equal contributions while deformation in the cortex was elastic and reversible. ^ Lastly, we investigated adhesive properties of polymer networks with the thiol-norbornene chemistry to explore their possible applications. The mechanical and adhesive properties of these PDMS networks were quantified by the contact adhesion test (CAT), as well as DMA and compressive measurements. E of these end-linked PDMS measured by CAT was comparable with that measured by the compressive test. In terms of the adhesion properties, the energy release rate was described as a function of crack velocity. A higher molecular weight between cross-links led to a higher adhesion energy over a range of crack velocity for the PDMS with the same end-linking chemistry. Sylgard PDMS with 18 to 1 ratio was chosen to compare the mechanical and adhesive properties to the end-linked PDMS. With the similar Young's modulus and resilience, the adhesion energy of the Sylgard PDMS was comparable to that of the end-linked PDMS with 5 kDa molecular weight, which was likely to result from the comparable molecular weight between cross-links.^

Evaluating the validity of MCAS scores as an indicator of teacher effectiveness

Copella, Jenna M — Wed, 22 May 2013 15:19:18 PDT

The Massachusetts Department of Secondary and Elementary Education (DESE) has implemented an Educator Evaluation Framework that requires MCAS scores be used as a significant indicator of teacher effectiveness when available. This decision has implications for thousands of Massachusetts public school teachers. To date, DESE has not provided evidence to support the validity of using MCAS scores to make interpretations about teacher effectiveness. A review of the literature reveals much variation in the degree to which teachers use state-adopted content standards to plan instruction. The findings in the literature warrant investigation into teacher practice among Massachusetts public school teachers. The research questions for this study will be: 1.) Are there variations in the degree to which Massachusetts public school teachers use the Curriculum Frameworks to plan Math instruction?; and 2.) Is MCAS as an instrument sensitive enough to reflect variations in teacher practice in the student's scores? A survey of Massachusetts public school principals and Math teachers, grades three through eight, investigated the research questions. Survey results revealed that Massachusetts teachers use the Curriculum Frameworks to plan instruction to varying degrees. Survey results also suggest a lack of relationship between teacher practice related to the use of the Curriculum Frameworks and student MCAS scores. These findings suggest MCAS scores may not be an appropriate indicator of teacher effectiveness; however, there are limitations to the study that require further investigation into these questions. ^

Analysis of the spatiotemporal localization of mitochondrial DNA polymerases in Trypanosoma brucei

Concepcon-Acevedo, Jeniffer — Wed, 22 May 2013 15:19:17 PDT

The mitochondrion contains its own genome. Replication of the mitochondrial DNA (mtDNA) is an essential process that, in most organisms, occurs through the cell cycle with no known mechanism to ensure spatial or temporal constrain. Failures to maintain mtDNA copy number affects cellular functions causing several human disorders. However, it is not clear how the cells control the mtDNA copy number. The mtDNA of trypanosomes, known as kinetoplast DNA (kDNA), is a structurally complex network of topologically interlocked DNA molecules (minicircles and maxicircles). The replication mechanism of the kDNA differs greatly with all other eukaryotic systems. Key features of the kDNA replication mechanism include defined regions for main replication events, coordination of a large number of proteins to drive the replication process, and replication once per cell cycle in near synchrony with nuclear S phase. Two main regions known as the kinetoflagellar zone (KFZ) and the antipodal sites are where main kDNA replication events are known to occur (i.e, initiation, DNA synthesis and Okazaki fragment processing). So far, the localization of the proteins involved in kDNA replication is restricted to two main regions: the KFZ and the antipodal sites. Three mechanisms that directly regulate kDNA replication proteins and serve to control kDNA replication have been proposed: (1) Reduction and oxidation status of the universal minicircle sequence binding protein (UMSBP) controls its binding to the origin sequence, (2) Trans-acting factors regulate the stability of mRNA encoding mitochondrial Topoisomerase II during the cell cycle and, (3) Regulation of TbPIF2 helicase protein levels by a HslVU-like protease to control maxicircle copy number. These mechanisms seem to be protein specific and it appears that a combination rather than a single mechanism regulates kDNA replication. ^ In this study we used Trypanosoma brucei to understand how mitochondrial DNA replication is controlled. We investigated the mechanism of how proteins transiently localize to the sites of DNA synthesis during cell cycle stages. Our data provides a comprehensive analysis of the first two examples of T. brucei kDNA replication proteins that have a cell cycle dependent localization (Ch. 2 and 3). The localization of two of the three essential mitochondrial DNA polymerases (TbPOLIC and TbPOLID) is under tight cell cycle control and not regulated by proteolysis. TbPOLIC and TbPOLID localize to the antipodal sites during kDNA S phase, however, at other cell cycle stages TbPOLIC becomes undetectable by immunofluorescent analysis and TbPOLID disperses through the mitochondrial matrix. In agreement with this data, TbPOLIC and TbPOLID replication complexes were not detected using affinity purification presumably because only a fraction of these proteins are participating in replication at a given time (Ch. 4). We propose that spatial and temporal changes in the dynamic localization of essential kDNA replication proteins provide a novel mechanism to control kDNA replication. ^

Tradition and modernity: The discursive construction of national identity in Chinese textbooks

Chen, Qingliang — Wed, 22 May 2013 15:19:16 PDT

This study explores and illustrates the construction and representation of Chinese national identity in Chinese language textbooks. It identifies the traditional and modern resources for conceptualizing the modern nation-state. It takes an approach to the study of national identity that integrates the discourse-historical method and the multimodal approach into critical discourse analysis (CDA). It describes and interprets the cultural and ideological dimensions of Chinese nationalism embedded in textbooks through verbal and visual representations. The perspectives presented in selected materials are examined with respect to how the national identity is discursively constructed in the textbooks after its economic transformation within the context of globalization. Key questions developed for this study are: (1) How is the nation imagined, represented, and projected to the world? (2) What cultural, historical, and symbolic resources do the textbooks use in the discourse construction of tradition and modernity? (3) How have textbooks drawn on evolving discourses of modern Chinese identity? Data is collected from two series of Chinese textbooks, including their corresponding student workbooks, teacher's manuals, and multimedia materials. Discourse-historical analysis is employed to understand how cultural meanings are encoded into the language of texts and serve to influence students' perception about China. Using multimodal analysis, it examines devices such as characterization, symbolism, and visual composition to extract ideological messages inherent within the text. It concludes that textbooks articulate an elite version of Chinese national identity. They present the Chinese nation as a historical and cultural entity by combining the assumptions of continuous Chinese civilization and of China as a modern nation-state. Through textbooks' cultural representations, the textbook authors address their audience, American students in our case, and embody Chinese national identity, modern progress, and historical continuity. ^

Framed: Native American representations in contemporary visual mediums

Carlson, Marta — Wed, 22 May 2013 15:19:15 PDT

For centuries, American media has consistently romanticized the image of the Native American Indian. This persistence in producing these romanticized stereotypical and therefore negative images of "Indians" in American popular culture through comic books, graphic novels, computer video games and tattoo imagery is a static narrative that relegates "Indians" to America's past. Consequently, these negative images which have been circulated, reproduced and received for generations, are now deeply – some may even argue inextricably-imbedded in the American national and global meta-narrative. As a result, Native American's protestations regarding their misrepresentation have been repeatedly rendered moot due to the non-native's belief of possessing an already and always knowing of Native American Indian culture. American media and the dominant culture which allows and perpetuates the continued production of stereotypical images deployed through rhetorical and contextual acts, is a blatant reflection of the Euro American consciousness, or lack there of, regarding "Indians".^

Effect of colloidal interactions on formation of glasses, gels, stable clusters and structured films

Atmuri, Anand Kumar — Wed, 22 May 2013 15:19:14 PDT

Colloidal suspensions are ubiquitous because of their vast industrial and household usage. We demonstrate that interactions between colloidal particles play a crucial role in manipulating the phase behavior and thereby the macroscopic properties of a variety of colloidal materials, including structured films, gels, glasses and stable clusters. First, we examined films comprised of two different colloidal particles and investigated the impact of colloidal interactions in manipulating the extent of segregation in the dried films. A transport model was used to predict the volume fraction profiles of the particles as a function of film thickness, which showed that segregation could be altered by changing the particle interactions. Experimental studies were carried out using different charged latex particles and varying the pH to change the interactions, and the results from experiments and model show a very good agreement to capture the extent of segregation. Second, we studied the effect of adding low molecular weight adsorbing and non-adsorbing polymers to suspensions to modify the interparticle interactions. We studied the structural dynamics and bulk rheology of a disk-shaped clay colloid, laponite^®, and polymer. Under basic conditions laponite^® forms a repulsive colloidal glass. We show that low concentrations of an adsorbing polymer retards glass formation, whereas at higher concentrations an attractive glass is formed. Thus, we obtain a type of re-entrant glass transition, which is a first of its kind observed in anisotropic colloids with adsorbing polymer. On the other hand addition of a non-adsorbing polymer to laponite^® suspensions triggers the formation of particle clusters, and increasing the concentration of polymer increases the strength of attraction between the particles and the size of the clusters. ^ To further understand formation of stable clusters, we utilized population balance equations (PBE) models to study aggregation of charged colloids under quiescent conditions. We considered particles with a DLVO-type potential, where the interactions are a sum of van der Waals attraction and electrostatic repulsion. Under certain conditions, the net repulsion between large aggregates and a single particle acts as a barrier against further aggregation, and clusters reach a stable size. The PBE model was used to map out regimes of uncontrolled aggregation, controlled aggregation, and no aggregation as a function of ionic strength and colloid weight fraction. The model was tested using experimental data on charged latex particles with different colloid weight fractions and ionic strengths. The model was able to predict the regime of controlled aggregation and final size of aggregates very well. However, the rate of aggregation predicted by the model was much faster than observed experimentally. Finally, we explored aggregation of latex particles in a shear environment similar to that used in industrial toner production processes. We studied the effect of temperature, pH and coagulant concentration on aggregation and showed that there is a optimum variable space to have aggregates of controlled size and distribution.^

Particle-collector interactions in nanoscale heterogeneous systems

Bendersky, Marina — Wed, 22 May 2013 15:19:14 PDT

Particle-surface interactions govern a myriad of interface phenomena, that span from technological applications to naturally occurring biological processes. ^ In the present work, particle-collector DLVO interactions are computed with the grid-surface integration (GSI) technique, previously applied to the computation of particle colloidal interactions with anionic surfaces patterned with O(10 nm) cationic patches. The applicability of the GSI technique is extended to account for interactions with collectors covered with topographical and chemical nanoscale heterogeneity. Surface roughness is shown to have a significant role in the decrease of the energy barriers, in accordance with experimental deposition rates that are higher than those predicted by the DLVO theory for smooth surfaces. An energy- and force-averaging technique is presented as a reformulation of the GSI technique, to compute the mean particle interactions with random heterogeneous collectors. A statistical model based on the averaging technique is also developed, to predict the variance of the interactions and the particle adhesion thresholds. An excellent agreement is shown between the models' predictions and results obtained from GSI calculations for large number of random heterogeneous collectors. ^ Brownian motion effects for particle-collector systems governed by nanoscale heterogeneity are analyzed by introducing stochastic Brownian displacements in particle trajectory equations. It is shown that for the systems under consideration and particle sizes usually used in experiments, it is reasonable to neglect the effects of Brownian motion entirely. Computation of appropriately defined Péclet numbers that quantify the relative importance of shear, colloidal and Brownian forces validate that conclusion. ^ An algorithm for the discretization of spherical surfaces into small equal-area elements is implemented in conjunction with the GSI technique and mobility matrix calculations of particle velocities, to obtain interactions and dynamic behaviors of patchy particles in the vicinity of uniform flat collectors. The patchy particle and patchy collector systems are compared in detail, through the computation of statistical measures that include adhesion probabilities and maximum residence times per patch. The lessened tendency of the patchy particle to adhere on the uniform collector is attributed to a larger maximum residence time per patch, which precludes interactions with multiple surface nano-features at a given simulated time. ^ Also briefly described are directions for future work, that involve the modeling of two heterogeneous surfaces, and of surfaces covered with many types of heterogeneity, such as patches, pillars and spring-like structures that resemble polymer brushes or cellular receptors.^

Impact resistant glassy polymers: Pre-stress and mode II fracture

Archer, Jared Steven — Wed, 22 May 2013 15:19:13 PDT

Model glassy polymers, polymethyl methacrylate (PMMA) and polycarbonate (PC) are used to experimentally probe several aspects of polymer fracture. In Chapter 1, the method of pre-stress is employed as a means of improving the fracture properites of brittle PMMA. Samples are tested under equi-biaxial compression, simple shear and a combination of biaxial compression and shear. Equi-biaxial compression is shown to increase the threshold stress level for projectile penetration whereas shear pre-stress has a large effect on the overall energy absorbed during an impact. There is also an apparent interaction observed between compression and shear to dramatically increase the threshold stress. Pre-stressed laminates of PMMA and PC show an increase in damage area because of the unique formation of a secondary cone. ^ In Chapter 2, the effect of stress state on stress relaxation in PMMA and PC is investigated. Direct comparisons are made between uniaxial and biaxial loading conditions. The experimental methods used highlight the effect of hydrostatic stress on the relaxation process. The data shows an increase in relaxation time and increase in the breadth of the relaxation spectrum with increases in hydrostatic stress. This suggests that the stress state can have a significant effect on the useful lifetime of pre-stressed articles. ^ In Chapter 3, Mode I and II fracture studies are performed from quasi-static to low velocity impact rates on PMMA and PC. Mode II testing utilizes an angled double-edge notched specimen loaded in compression. The shear banding response of PMMA is shown to be highly sensitive to rate, with diffuse shear bands forming at low rates and sharp distinct shear bands forming at high rates. As the rate increases, shear deformation becomes more localized to the point where Mode II fracture occurs. PC is much less rate dependent and stable shear band propagation is observed over the range of rates studied with lesser amounts of localization. A new theory is formulated relating orientation in a shear band to intrinsic material properties obtained from true-stress true-strain tests. In a qualitative sense the theory predicts the high rate sensitivity of PMMA. A kinematic limit for orientation within a shear band is also derived based on entanglement network parameters. Mode II fracture in PMMA is shown to occur at this kinematic limit. For the case of PC, the maximum impact rates were not high enough to reach the kinematic limit. ^ In Chapter 4, the deformation response, as observed in a shear band is interpreted through the characterization of the "intrinsic material properties" obtained from true stress—true strain 8compression tests. The relatively high rate sensitivity of PMMA deformed at room temperature is related to the proximity of the beta transition to the test temperature. This is also shown in corollary experiments on PC where deformation near the beta transition is accompanied by an increase in rate sensitivity. Physical aging results in a more narrow alpha transition and is shown to increase strain localization and decrease rate sensitivity at low strain rates.^

Lactic acid bacteria mediated phenolic bioactive modulation from fruit systems for health benefits

Ankolekar, Chandrakant R — Wed, 22 May 2013 15:19:12 PDT

Chronic oxidation linked diseases are on a rise and are one of the leading causes of death globally. Epidemiological evidence increasingly points towards consumption of fruits and vegetables as a preventive way to manage early stages of chronic oxidation linked diseases. Oxidation linked diseases are caused by excessive reactive oxygen species (ROS) generated by a disruption in cellular antioxidant homeostasis due to an overload of calories combined with stress, no excerise and a diet low in antioxidants. Phenolic compounds can not only act as antioxidants but also stimulate the activities of antioxidants enzyme through protective pathways which can help modulate cellular protection. ^ The aim of this dissertation was to use probiotic fermentation to enhance the phenolic and antioxidant compounds in fruit systems which can form the basis of functional food design. The potential of these food systems for disease prevention was investigated in eukaryotic systems through understanding the role of critical metabolic pathways involed in prevention of oxidation linked chronic diseases. Based on structure-function rationale, antioxidant, anti-hyperglycemia and anti-hypertensive potential of phenolic compounds in tea and the effect of extraction time and different degrees of fermentation were investigated in in vitro models. Results indicated that the most fermented teas and a longer extraction time had the highest potential. Further these extracts also had higher H. pylori inhibition potential. Probiotic fermentation of fruit juices with L. helveticus was used to mobilize phenolics and improve biological functionality by maintaining a consistent phytochemical profile. Results indicated that total phenolic and antioxidant potential decreased with feremnetation. However &agr;-glucosidase inhibitory activity and H. pylori inhibitory potential increased with fermentation. Investigation into the mechanism of H. pylori inhibition with fermented cherry extracts revealed inhibition of proline dehydrogenase as the likely mode of action. The potential of fermented apple extracts was further investigated as a phytochemical elicitor in eliciting phenolic and antioxidant response in germinating fava bean. The results indicated a stimulation of phenolic and antioxidant response likely through the stimulation of carbon flux through glycolytic pathways. In yeast, fermented apple extracts accelerated cell death in the presence of peroxide stress in pretreatment model whereas it provided protection against oxidative stress and prevented cell death in concurrent model. Chitosan oligosachharide treatment was investigated as a potential replacement of cancer causing diphenylamine treatment for scald reduction in Cortland apples. Although the treatment did not have any effect on scald reduction, it provides better protection in storage by stimulating phenolic and antioxidant response which related to better health relevant functionality.^

Mesostructural characterization and probabilistic modeling of the design limit states of parallel strand lumber

Amini, Alireza — Wed, 22 May 2013 15:19:11 PDT

Over recent decades, the public tendency toward using the structural composite lumber (SCL), a common composite of wood made of wood strands or veneers glued and compressed together, as structural members (especially the main load bearing members such as beams and columns) has risen considerably. In contrast to the fast-paced market growth of these products, development is slow. The experimental development is gradual and time-consuming and the computational development is even slower. The objective of this project is to introduce appropriate numerical models for limit state analysis of a certain type of SCL material called PSL. ^ Parallel strand lumber (PSL), has mesostructures characterized by the presence of voids that renders the mesostructure highly heterogeneous. In addition to material phase aberrations such as grain angle variations and defects, void heterogeneities play an important role in determining the failure modes and strength of PSL. In this study, virtual void structures were defined to form part of the input to finite element analysis of PSL for the purpose of investigating the sensitivity of strength to the void structure. Assuming the wood phase to be homogeneous and orthotropic, the following 2D and 3D characteristics of voids were investigated: volume fraction, volume, alignment and moments of inertia of voids, as well as second moment properties, lineal path function and chord length functions of the two phase mesostructure. In addition, a method was developed to generate virtual voids in order to simulate PSL and investigate the possible effects of the void distribution on material strength. ^ An experimental program along with a statistical survey was conducted to quantify the mentioned characteristics of the voids in two 133 mm * 133 mm * 610 mm 2.0 E Eastern Species PSL billets. As expected, most of the voids lie on the longitudinal direction of the specimen and have approximately an ellipsoidal shape. Based on this shape data, the characteristics of the ellipsoids which best fit the voids were calculated. Using the statistical data of the fitted ellipsoids, a random field of virtual ellipsoid shaped voids to simulate the mesostructure of PSL was generated. ^ In this study, the simulation of PSL material is based on two simplifying assumptions: 1) The wood phase is continuum, homogeneous and orthotropic. While in reality, the wood phase consists of glued wood strands that are heterogeneous due to their mechanical variability and only roughly orthotropic on a macro scale as a result of the varying fiber angle; 2) Voids are the mere source of uncertainty. The linear elastic analysis of carefully defined (in mesostructural aspect) PSL models can be the first step of mechanical study of the material. The effective modulus of elasticity of material in presence of voids and the distribution of conventional, principal and effective stresses considering the effect of volume fraction and shape of the voids are the target of this preliminary study. Linear elastic uniaxial analyses showed good mechanical consistency between the models including actual void shapes and the models including ellipsoidal void representations. Also, they showed that the stress mutliaxiality at the tip of the voids is negligible. ^ The study of mechanics of PSL is incomplete unless the question of material anisotropy is taken into consideration. PSL is brittle in tension and ductile in compression. The material heterogeneity increases the complexity of the problem by affecting the stress distribution in the member. A detailed nonlinear approach has been proposed in order to investigate the mechanical behavior of PSL structural members under different uniaxial loading scenarios. This approach introduces proper constitutive models for the wood phase along with good void generation techniques. In other words, this approach suggests what models should be used for the continuum-assumed wood phase to simulate its brittle behavior in tension and ductile behavior in compression; and moreover, tests the applicability and accuracy of ellipsoidal void representation. The models are calibrated using the results of experiments on PSL material. ^ Because of the brittle behavior, all wood products show significant mechanical dependency to the member's size under tensile loading. Once good constitutive model and mesostructural simulation is found for tensile loading, it is easy to make and analyze PSL models with different sizes and investigate the effect of size on mechanical behavior. The simulation results have been compared to the available results of a previously done experimental study.^

Uncovering the covered word and image: Framing a Blackwoman's Diasporan stage-space

Abdullah Matta, Allia — Wed, 22 May 2013 15:19:10 PDT

My dissertation considers the ways in which African/African Diasporan women creatively and politically address and respond to the public communal and societal narratives around being Black, as a result of how Blackness is received and often perceived in a very essential way, in American and European societies. This study notes and complicates how African and Black Diasporic women create and sustain a space that evokes a combative discourse, as they recreate and represent themselves in literary and visual texts. The framework of my dissertation articulates three core objectives: to redefine and re-envision "Black" as it applies to creative and theoretical writing about African and African descended women writers and visual artists; to define/discuss the concept of an African Diaspora and a "Black Diasporan " consciousness that adequately represents the complexities of Black women's identities in different geopolitical and cultural locations; and to situate the significance of the cultural and literary production of Black women writers and artists as combative discourse. ^ This study situates and argues that being Black and being a woman are important sites of critical inquiry. These sites of inquiry must therefore be assessed and analyzed by considering the specific historical positionalities and truths that appear and live in the texts of Black women writers and artists. The idea of "uncovering" points to a specific interdisciplinary method of reading the symbolism and imagery of these women's texts that employs an intersectional analysis and considers diverse Black feminist, art historical, cultural studies, and African Diaspora epistemological standpoints. I argue that specific literary and visual texts posit a very particular and diverse Black woman's history and culture as well as presenting counter narrative(s) to the mainstream narrative(s) that negate Black women. This study addresses the specificities of Black women as creators and cultural producers, their texts, and their representative images by considering a multi-level analysis; therefore, no one narrative or text privileges another. My dissertation establishes an intellectual and creatively political kitchen space of sorts where the texts and images of Black women meet, impart wisdom, and hold court. I argue that this sacred intellectual and artistic space is where these texts not only address being Black and Blackness, but also proffers an important Africana body-politics and autonomy. This project begins with a discussion that considers writers Yvonne Truque America, Charmaine Gill, and artists Deborah Roberts and Lezley Saar (to name a few) and the ways in which their texts converge as combative discourse. My study then focuses on Sonia Sanchez and a selection of her texts as the creative and theoretical core of the combative discourse. Sanchez represents an important foundation and beginning of this discourse as she is a genre-crosser and cultural practitioner who illustrates a crucial allegiance to the identity and representative voices of Black women, the Black communal collective, and a global political aesthetic. Sanchez embodies activism as well as an important Africana aesthetic blending that further complicates the combative discourse. ^ Further, Sanchez represents a legacy of Black women's texts and functions as a foremother to poets and performers such as Jill Scott and Ursula Rucker as indicated by a close reading of their texts. These writers further the poetic and dramatic spheres of the combative discourse and also provide a complexly layered political and cultural aesthetic. The combative discourse therefore illustrates the complexities and politics of context, text, subtext, voice, image, and representation, while situating the ways in which the particular cultural, historical, and socio-political lenses impact Black women's literary and visual texts.^

Farm-to-fork: Understanding locally-oriented farm-to-vendor food systems: Access, boundaries, and power-relations

Trivette, Shawn A — Wed, 22 May 2013 15:19:09 PDT

Locally oriented food has recently gained considerable popularity as an alternative to the industrial food system. Current scholarship on local food has typically focused on direct-to-consumer (DTC) arrangements, such as farmers' markets or CSAs. Yet other players besides producers and consumers engage with locally-oriented food. Food vendors (restaurants, retailers and grocers, and value-added food processors) have recently entered the scene and locally-oriented farm-to-vendor arrangements constitute one of the cutting edges of the development of local food systems. ^ This dissertation studies one such local food system in southern New England. Utilizing a mixed methods approach entailing social network analysis, in-depth interviews, fieldwork observations, and GIS analysis, this study interrogates how direct-to-vendor (DTV) local food systems operate. I show through the literature review that though local food systems hold considerable promise, they are not inherent mechanisms of sustainability. Next I turn to the question of what "counts" as local, examining the range of distances farms and vendors within this region travel to sell or purchase food, and asking what are the forces and conditions that influence this range of travel? The greatest influences are number of ties to other local food entities, what type of farm or food-vendor they are, size, and urban proximity. ^ I then focus on key participants in the area of study. What are the challenges and constraints around developing a vibrant locally-based food system? These participants face continual pressure to expand their size and markets, emulating the dominant food system and thereby undercutting their sustainable potential. However, these participants also find ways to overcome what are sometimes contradictory interests to forge a functional locally-based food system based on reciprocity and trust. ^ Due in part to price premiums on local food many local food participants tend to be white and have high incomes and levels of education. In the final empirical chapter I ask: in what ways do these inequalities manifest systematically? By geospatially mapping the locations of local food outlets against census data on race, income, and education, I show that racial and class advantages are perpetuated in terms of people's proximal access to these local food outlets. ^

Governing piety: Islam, empire and moderation in late modernity

Lepori, Dunya D — Wed, 22 May 2013 15:19:07 PDT

Based on ethnographic fieldwork, textual analysis, and data culled from interviews, this manuscript explores how Islamic ethics shape the epistemic approaches of Muslim intellectuals to liberal democracy and corollary paradigms of western modernity. Specifically, it examines a critical discursive field of resistance generated by Muslim intellectuals in Turkey affiliated with Islamist NGOs and publishing houses. In response to the promotion of a ‘mild Islam’ compatible with democracy and liberalism in the context of Turkey, itself represented as the ‘model country’ in such regional schemes of democratization as the Greater Middle East Project, a radical movement emerged that appropriates the Islamic identity as a basis of resistance to the processes of hybridization, identitarian eclecticism and postmodern pluralism. The significance of this activism resides in the articulation of a discursive domain that (a) does not conform to the liberal protocols of intelligibility but (b) is produced through contact with liberal-democratic discourses of moderation. How does moderation as a normative standpoint create a space for political intervention? Through this question, I map out the processes and mechanisms by which ‘moderation’ as a transcendental and universal concept, concomitant with democratic subjectivity, operates as a political discourse and a moral-political practice of governmentality, functioning to suture democracy with liberal norms of conduct. ^ My objective here is threefold: first, I detail the interaction between global paradigms of a neo-liberal, democratic postmodernity (with its ideals of tolerance, dialogue, religious pluralism) and local modalities of resistance embedded in Islamic piety. Second, by excavating local efforts at defamiliarizing the democratic paradigm within the intellectual community of Qur’anic Generation, I draw the contours of an Islamic epistemology of resistance, an antidiscipline which reinvents civil society as a space for moral resistance to democratic norms. Third, I problematize the extent to which scholarly production reinforces the liberal-democratic universal imaginary, which I accomplish by highlighting the ubiquity of liberal epistemological commitments found in democratic theory and empirical studies on civil society in the Middle East. Perceptible in western democratic theory is a recurrent ontopolitical pattern in theorizing the democratic subject through an ascetic norm of dispassionateness and moderation. ^

The silent majority: An examination of nonresponse in college student surveys

Kolek, Ethan A — Wed, 22 May 2013 15:19:06 PDT

Nonresponse is a growing problem in surveys of college students and the general population. At present, we have a limited understanding of survey nonresponse in college student populations and therefore the extent to which survey results may be biased. The purpose of this dissertation is to explore three facets of nonresponse in surveys of college students in order to strengthen our empirical and conceptual understanding of this phenomenon. This dissertation seeks to contribute to our understanding of who participates in surveys and who does not, how students experience the process of being asked to complete surveys, and whether or not students’ perspectives about surveys suggest that college student surveys should be conceptualized as organizational surveys. To begin to answer these questions, I conducted three studies—a secondary data analysis that examines student characteristics associated with the odds of completing a survey, a “survey on surveys” study that asks students about their experiences with surveys, and a series of focus groups to understand how students made sense of surveys at their institutions. Taken together, these findings provide a basis for a more developed and nuanced understanding of nonresponse in student surveys. ^

Retrieval and evaluation techniques for personal information

Kim, Jinyoung — Wed, 22 May 2013 15:19:05 PDT

Providing an effective mechanism for personal information retrieval is important for many applications, and requires different techniques than have been developed for general web search. This thesis focuses on developing retrieval models and representations for personal search, and on designing evaluation frameworks that can be used to demonstrate retrieval effectiveness in a personal environment. ^ From the retrieval model perspective, personal information can be viewed as a collection of multiple document types each of which has unique metadata. Based on this perspective, we propose a retrieval model that exploits document metadata and multi-type structure. Proposed retrieval models were found to be effective in other structured document collections, such as movies and job descriptions. ^ Associative browsing is another search method that can complement keyword search. To support this type of search, we propose a method for building an association graph representation by combining multiple similarity measures based on a user's click patterns. We also present a learning techniques for refining the graph structure based on user's clicks. ^ Evaluating these methods is particularly challenging for personal information due to privacy issues. This thesis introduces a set of techniques that enables realistic and repeatable evaluation of techniques for personal information retrieval. In particular, we describe techniques for simulating test collections and show that game-based user studies can collect more realistic usage data with relatively small cost.^

Why Sacrifice Sovereignty? A Non-Instrumental Explanation of State Support for Supranational Cooperation in EU Common Foreign and Security Policy

Kiratli, Osman Sabri — Wed, 22 May 2013 15:19:04 PDT

This dissertation presents a constructivist approach to explain varying levels of member state support for supranational cooperation in the EU Common Foreign and Security Policy in 2002 through 2004. It examines the possible effects of three independent variables—popular identification with Europe, normative parity between national foreign policy and CFSP institutions, and national threat perceptions, on the level of support for supranational reform of the CFSP during the European Convention and Intergovernmental Conference producing the proposals on CFSP eventually adopted in the Lisbon Treaty of 2007. After an in-depth analysis of four countries, Germany, Netherlands, UK and Greece, this study concludes that in Germany, the Netherlands, and the UK, the two ideational variables—level of identification with Europe and parity between national and EU foreign policy norms—are positively correlated with the level of support to supranationalism. Only in the case of Greece are threat perceptions the driving reason for Greek levels of support for reforms increasing the supranational character of CFSP. This suggests that ideational factors and threat perceptions offer two different routes to member state support for supranational integration in common foreign and security policies. ^

Studies in consumer procrastination

Haj Azim Zanjani, Shabnam — Wed, 22 May 2013 15:19:02 PDT

Consumer procrastination is an understudied phenomenon in marketing. Through three essays, this dissertation extends the knowledge of consumer procrastination by examining dispositional and situational causes of several constructs and behaviors related to procrastination, the subsequent impact of procrastination on marketing- relevant variables such as cognitions, experiences, emotions, and behaviors, and the role of variables that moderate the effect of procrastination. ^ Using a multi-trait, multi-method, multi-context, and multi-sample approach, Essay 1 examines the effect of trait procrastination, the Big-Five personality factors, and the characteristics of the task at hand on procrastination behavior. The results of an online survey and a SMS-based Experience Sampling Method show that Internet-enabled procrastination explains online procrastination behavior of the younger and older generations. The findings also indicate that indecisive procrastinators are agreeable and neurotic but less conscientious and open to experience; high task procrastinators are neurotic and less open. ^ Essay 2 examines the joint effects of trait procrastination and goal-directedness of online activities to explain how consumers experience flow online and how they respond to marketers' influence strategies. The result of an online survey shows decisional procrastination leads to greater Internet-enabled procrastination which in turn, leads to greater flow and purchase behavior. Goal-directedness increased (decreased) purchase frequency for non-procrastinators (indecisive procrastinators). The proposed model of flow re-enforces the importance of this compelling experience in increasing online purchase decisions and simultaneously provides theoretical understanding on how online procrastination acts as an addictive behavior. ^ Essay 3 examines the market versus personality-related antecedents of consumer procrastination and its consequences in terms of post-decision cognitions, emotions and behaviors through a series of scenario-based experiments. The results indicate time limit, price uncertainty, price consciousness, sale proneness and prestige seeking positively influence consumer delay in making purchase decisions. Further, the positive impact of uncertainty is only salient when people have short time limits rather than long ones. We also found when the outcome knowledge is unpleasant, respondents who decided to wait for a better sale experience greater self-responsibility and regret but have lower intention for exit, voice or WOM compared to the people who had purchased the product. ^

A social history of power and struggle in Turkey: State, memory, movements, and identity of outsiderness in Dersim

Goner, Ozlem — Wed, 22 May 2013 15:19:01 PDT

In my dissertation I analyze the relationships between historical and everyday state-formation and the making and remaking of the people and landscapes of Dersim, produced as the outsiders of state. I focus on three periods: the massacre and the following displacements in Dersim known as 1938; the growth of capitalism in Turkey and the leftist movements in Dersim between World War II and the coup d’etat of 1980; and, finally, the rise of the PKK (Kurdish Worker’s Party) and the “state of exception” in Dersim in the 1990s. I conclude with a discussion of the last decade where the history, identity, and nature of Dersim have been central to various social and political organizations through the first public recognitions of 1938 after seventy-two years, and a developing anti-dam politics. ^ I mobilize archival methods, field research, in-depth and multiple-session interviews with three consequent generations, and focus groups. Through analyzing state and newspaper archives of the 1930s, and the “extraordinary laws” of the 1980s and 1990s, I discuss multiple narratives and discourses about Dersim, how outsiders came to be defined as “exceptions to the law,” and how they are managed in different periods. Through field research in different settlements and political organizations, interviews, and focus groups, I analyze the mechanisms through which experiences and memories of state violence are transferred and mobilized by different generations to construct identities and oppositional movements. ^ I argue that relations of power and struggle can be analyzed only historically and in relation to each other. More specifically, the state, movements and identity are related and founded upon the making of “outsiderness.” On one hand, the making of the outsiders contributes to the productions of the nation and consolidation of state power. On the other, outsiders identify with and mobilize “outsiderness” as a generalized category of a counter-hegemonic identity. I argue that outsiderness is transferred through subjective constructions of history in the form of memory and consciousness, mediated through personal interactions with the state, and transformed by the movements. As an identity produced simultaneously by the state and the people, outsiderness is both enabling and paralyzing for movements. ^

Verbalizing in the second language classroom: The development of the grammatical concept of aspect

Garcia, Prospero N — Wed, 22 May 2013 15:19:00 PDT

Framed within a Sociocultural Theory of Mind (SCT) in the field of Second Language Acquisition (Lantolf & Thorne, 2006), this dissertation explores the role of verbalizing in the internalization of grammatical categories through the use of Concept-based Instruction (henceforth CBI) in the second language (L2) classroom. ^ Using Vygotsky's (1986) distinction between scientific and spontaneous or everyday concepts applied to L2 development (Negueruela, 2008), this study focuses on the teaching and potential development of the grammatical concept of aspect in the Spanish L2 classroom, and the role of verbalizing in its internalization. It is proposed that verbalizing mediates between the learners' initial understandings of the grammatical concept of aspect, the development of conscious conceptualizations, and students' written and oral production of preterite and imperfect grammatical forms. ^ This study presents and analyzes data from one of the thirty-two adult college students enrolled in an advanced Spanish conversation course. ^ Data is analyzed through a clinical analytic approach, which has its roots in Vygotsky's (1978) genetic method of analysis. The study was carried out over a 12-week period and collected multiple sets of developmental data, including learners' definition of the grammatical concept of aspect, written performance protocols, and verbalization data recorded during two oral interviews. The study interprets learner performance in these three complementary, and dialectically connected types of L2 conceptual data. A close analysis of this participant's data provides critical insights to understand the role of verbalizing in L2 conceptual development. ^ Findings confirm that learners' verbalizations are key factors to ascertain L2 conceptual development, as well as a mediational tool that fosters learners' internalization of the grammatical concept of aspect. It is proposed that verbalizing notably contributes to research on L2 development. Not only does it allow the researcher to have a more comprehensive picture of L2 development, but it also helps learners develop a more sophisticated semantic understanding of the grammatical concept of aspect and fosters their ability to understand and control relevant grammatical features in L2 communication. ^

Technologies of racial formation: Asian-American online identities

Dich, Linh L — Wed, 22 May 2013 15:18:59 PDT

My dissertation is an ethnographic study of Asian-American users on the social network site, Xanga. Based on my analysis of online texts, responses to texts, and participants’ discussions of their writing motivations, my research strongly suggests that examining digital writing through participants’ complex and overlapping constructions of their community and public(s) can help the field reconsider digital writing as a site of Asian-American rhetoric and as a process of constructing and transforming racial identities and relations. In particular, I examine how community and public, as interconnected and shifting writing imaginaries on Xanga, afford Asian-American users on this site the opportunity to write, explore, and circulate their racial and ethnic identities for multiple purposes and various audiences. Race and ethnicity, as many scholars argue, are shifting and unstable concepts and experiences. Therefore, writing about race and ethnicity may be done best in environments that can accommodate complex and multiple acts of racial and ethnic formations. ^ While my research demonstrates how participants “want to be heard” on their own terms, whom they imagine (or want to imagine) as listening/reading significantly informs their writing. That is, participants’ conceptions of their writing goals and their audiences are multiple and simultaneous—these racial and ethnic writing acts are often inflected by intersecting issues of gender, sexuality, class, culture, and intergenerational tensions—and, hence, traditional writing genres that limit such goals, audiences, and complexity do not always reflect how writers conceive of their own racial and ethnic experiences and their writing in the world. This study, then, examines Xanga as a flexible writing ecology that affords Asian-American users opportunities to compose their continuously transforming and complex racial and ethnic identities across multiple niches of representational sites and, specifically, in public and community spaces. ^

Adsorption column studies to predict the flow of nutrients through heterogenous porous media under equilibrium and isothermal conditions

Pandey, Vijai B — Wed, 22 May 2013 15:18:57 PDT

Because of the endangerment of life of the human beings due to the environmental pollution, a serious study of the pollution of the environment is most vital. Because of increasing surface water pollution there is great hazard of ground water pollution. About half the United States of America derives drinking water from aquifers and much of the projected demand is expected to be met from subsurface sources. Therefore, a study was needed to determine the process of ground water contamination due to nutrients, especially Nitrogen, its degree and Length and Time of Travel and factors inhibiting its flow through soil. ^ The present study was undertaken at the 'Pine Crest Duck Farm' at Sterling, Massachusetts, where the nature of the soil was Gravely Sandy Loam and Three unlined (from the side and bottom) waste stabilization ponds existed and there was a great danger of ground water contamination due to Nitrogen in the vicinity of ponds and further. In the field, observation wells were installed along the redial line and bi-monthly samples of water were taken to monitor the levels of B.O.D., Ammonium, Nitrate and Nitrite Nitrogen. ^ Since the Adsorption of the Nitrogen by the soil is great inhibitor in the movement of the Nitrogen through soil profiles, this study was undertaken to study the adsorptive capacity of the soil in 'Bench Tests' and to test the applicability and validity of various adsorption isotherms of nitrogen in the soil; to develop a dimensional model or prediction equation for the nitrogen in the soil under natural flow conditions by studying the effects of varying concentration and flow rates on the adsorptive capacity of the soil, based on the principles of similitude; to correlate adsorption values in bench and column tests; and to determine the length and time of travel of nitrogen through soil. ^ The soil from the Farm was obtained from a depth of six feet with enough care so that original structure was maintained. Adsorptive capacity of the soil was determined through series of 'Bench Tests' and 'Soil Adsorption Columns' in the laboratory under temperature controlled chambers. From the Bench Tests Adsorption values of the soil at various concentrations of Ammonium, Nitrate and Nitrite Nitrogen were determined and validity and applicability of Adsorption isotherms were confirmed. ^ To study the Adsorption Process under natural flow conditions 'Soil Adsorption Column Tests' were done by using never done before Dimensional Model Analysis of Factors affecting Adsorption and getting dimensionless numbers and further obtaining 'Break Through Curves' at different Concentration and flow rates and Adsorption Values were obtained for Ammonium Nitrogen and Nitrite Nitrogen. Finally, Component and Prediction Equations were obtained for Ammonium Nitrogen and Nitrate Nitrogen. ^ By knowing the Adsorption Values of the soil Length and Time of Travel of Ammonium and Nitrate Nitrogen through soil was calculated at various Concentration Levels. A mathematical Prediction Equation was also obtained between Bench and Column Tests and Length of Time of Travel, t predict the adsorption values under natural flow conditions by just performing less time consuming Bench Tests. ^ It was also found that under equilibrium Bench Test conditions and natural flow conditions, adsorption of Ammonium, Nitrate and Nitrite Nitrogen increased with increasing solution concentration and adsorption of Ammonium Nitrogen was considerably higher than Nitrate and Nitrite Nitrogen. It was further found that for solution concentrations of 20, 40, 60, 80 and 100 mg/l Ammonium Nitrogen and nitrate nitrogen will travel one foot distance in 183 and 115 days; 168 and 111 days; 148 and 98 days; 145 and 81 days; 130 and 98 days; and 127 and 97 days respectively. It was determined that at the present time contamination of shallow water wells does not pose Nitrogen contamination problem and installation of these wells beyond 300 feet radial distance from the waste stabilization ponds was safe. ^