ScholarWorks@UMassAmherst
We are now able to accept submissions directly in ScholarWorks. For submissions that are not doctoral dissertations or masters theses, please log in with your NetID, click the + (plus) in to the top left corner, and select the Submit Research option.
Graduate students filing for February 2025 degrees: We are now accepting submissions directly to ScholarWorks. Directions for submissions can be found in this guide. Please email scholarworks@library.umass.edu if you have any questions.
Request forms are functional. If you do not receive a reply to a submitted request, please email scholarworks@library.umass.edu.
This site is still under construction, please see our ScholarWorks guide for updates.
Recent Submissions
Publication Convective forces contribute to post‐traumatic degeneration after spinal cord injury(Wiley, 2025-01-14)Spinal cord injury (SCI) initiates a complex cascade of chemical and biophysical phenomena that result in tissue swelling, progressive neural degeneration, and formation of a fluid-filled cavity. Previous studies show fluid pressure above the spinal cord (supraspinal) is elevated for at least 3 days after injury and contributes to a phase of damage called secondary injury. Currently, it is unknown how fluid forces within the spinal cord itself (interstitial) are affected by SCI and if they contribute to secondary injury. We find spinal interstitial pressure increases from −3 mmHg in the naive cord to a peak of 13 mmHg at 3 days post-injury (DPI) but relatively normalizes to 2 mmHg by 7 DPI. A computational fluid dynamics model predicts interstitial flow velocities up to 0.9 μm/s at 3 DPI, returning to near baseline by 7 DPI. By quantifying vascular leakage of Evans Blue dye after a cervical hemi-contusion in rats, we confirm an increase in dye infiltration at 3 DPI compared to 7 DPI, suggestive of higher fluid velocities at the time of peak fluid pressure. In vivo expression of the apoptosis marker caspase-3 is strongly correlated with regions of interstitial flow at 3 DPI, and exogenously enhancing interstitial flow exacerbates tissue damage. In vitro, we show overnight exposure of neuronal cells to low pathological shear stress (0.1 dynes/cm2) significantly reduces cell count and neurite length. Collectively, these results indicate that interstitial fluid flow and shear stress may play a detrimental role in post-traumatic neural degeneration.Publication Rapid Detection of Titanium Dioxide in Food Products using X-Ray Fluorescence Spectroscopy(2024-09)Titanium dioxide (TiO2) is a white, odorless, and tasteless powder used as the colorant E171 in candies, pudding, coffee creamers, etc. The potential toxicity of E171 led to its ban as a food additive in the EU starting 2022, when the European Food Safety Authority (EFSA) declared E171 as no longer considered to be safe when as a food additive, as they could not exclude genotoxicity concerns after consumption of titanium dioxide particles. However, the current regulations imposed by the US FDA only restrict the amount of TiO2 used in food, which is set at 1% by weight of the food and it is not required to be explicitly listed on the label. There are large knowledge gaps about the amount of titanium dioxide being used in food products in the US and how much of the population is being exposed to it. This study investigates the use of X-ray Fluorescence (XRF) to fill these gaps by developing a rapid and effective method to detect the presence of E171 in various food products and quantify the concentration by weight. This method will help to obtain exposure and concentration data to enable regulatory bodies to facilitate a reliable risk assessment. Since existing methods for detection such as Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) are expensive, require lengthy sample preparation and utilize dangerous chemicals such as hydrofluoric acid, there is a dire need for a more rapid and cost-effective way to detect and quantify TiO2 in food. A standard curve with standards from 0.005% to 2% for quantifying the mass concentration of TiO2 was established by using a mixture of E171 with either sucrose or starch as a filling material. Sucrose yielded an excellent linear curve with r2 = 0.9962 and showed limit of detection (LOD) of 0.00059% and limit of quantitation (LOQ) of 0.00197%. A total of 40 food samples in the powder matrix were purchased from the market with and without E171 label claim and tested using XRF. Results showed the presence of E171 in 30 samples, with 16 samples having explicit label claim and 14 samples without. The concentrations ranged from 0.003% to 0.486% TiO2 with the highest category being coffee creamers and the lowest TiO2 content in seasonings. The method was validated by running the samples on ICP-MS which yielded similar results. Recovery tests were also run giving percent recovery in the range of 70%-100%. This method was also adapted to include other matrices that food products exist in, such as solid, semi-solid and liquid. Several sample preparation methods were tested for semi-solid samples. An emulsion was developed to create a standard curve with concentrations from 0.005% to 2%, which showed great linearity with r2 = 0.9959 and LOD = 0.000054% and LOQ = 0.00018%. This showed optimal results and was used for analysis of all products in this matrix. The highest concentration was found in a Queso Blanco with 0.739% TiO2. Other matrices such as solid included hard candy products, which could be quantified using the previous standard curve. This proves the ability of XRF to perform elemental analysis in a wide range of products. However, some limitations of the method include samples such as jellies and certain confectionery items which require a more specific and extensive preparation method to be used with XRF. Recovery tests were used for validation and percent recovery values from 80%-100% show that this can be a great semi-quantitative method, which is capable of screening a large number of food products for E171 in a rapid and efficient manner. An exposure assessment was also performed by considering the population consumption data from national surveys and amount of titanium dioxide present in each product. Estimated daily intake was obtained as 0.795 mg/kg bw. Overall, this study has proposed a valuable tool to rapidly and effectively detect and quantify or semi-quantify TiO2 in food and filled the existing gaps about population exposure to this additive.Publication Does Climate Change Initiate Migratory Tradeoffs that Influence Reproduction in a Long-distance Migratory Shorebird, the Hudsonian Godwit (Limosa Haemastica)?(2024-09)Climate change induced shifts in resource phenology threatens to negatively impact migratory species that are unable to alter their migratory and reproductive timing accordingly. Yet, many long-distance migrants are not advancing their reproductive timing at the same rates as their migratory timing. Some long-distance migrants may only be able to alter their migratory timing through costly en route decisions, presenting individuals with a tradeoff between early arrival and arrival body condition. For species that exhibit mate fidelity and rapid clutch initiation, arriving to the breeding grounds in poor condition may affect sexes differently, constraining advances in reproductive timing. Little is known, however, about the potential sex-specific effects of climate change on migrants and how they may influence reproduction. Thus, I utilized long-term tracking data in combination with isotope analyses to investigate whether there is a tradeoff between arrival timing and body condition that influences reproduction in a breeding population of Hudsonian Godwits (Limosa haemastica).Publication L'Inadaptee d'Argelouse: Examining Queerness, Alterity, and Silence in Therese Desqueyroux by Francois Mauriac(2024-09)Women have taken center stage in French literature for centuries as central protagonists in the struggle for self-definition. Female characters typically struggle under oppressive and repressive gender roles enforced by strict social norms, the lack of property rights in inheritance, and the difficulty in finding gainful employment to provide for a measure of their own autonomy. By examining Francois Mauriac’s Thérèse Desqueyroux (1927), we find ways in which Thérèse attempts to resist the lot given to her and fight back to gain a chance at self-determination. This study examines the language employed by the author to describe the repression and resilience of this woman, the use of poison as a means to resist patriarchal structures, how patriarchal oppression is portrayed as toxic, the ways in which the repressed sexuality of Thérèse is portrayed in the novel versus the film, and the ways in which her society attempts to resist the autonomy she tries to assert.Publication Comparing Estimates of Physical Activity from Two Accelerometer Locations and Direct Observation during Equine-Assisted Therapy in Neurodivergent Children(2024-09)Measuring physical activity (PA) in neurodivergent children during equine-assisted therapy (EAT) presents unique challenges. While accelerometers are commonly used to assess PA, their accuracy in this specific population and context remains unexplored. PURPOSE: This study aimed to compare PA estimates from wrist-worn and hip-worn accelerometers to direct observation during EAT sessions in neurodivergent children and adolescents. METHOD: Eight participants (mean age 8.7±2.2 years) wore ActiGraph GT3X+ accelerometers on the hip and non-dominant wrist during one-hour EAT sessions. Direct observation using the Movement Observation in Children and Adolescents (MOCA) system was also used to assess the participants’ PA and served as the criterion measure. Sedentary behavior, light PA (LPA), and moderate-to-vigorous PA (MVPA) were assessed. Agreement between methods was evaluated using Wilcoxon signed-rank tests, percent agreement, and Cohen's kappa. RESULTS: Both accelerometer locations significantly overestimated sedentary behavior and LPA while underestimating MVPA compared to direct observation (p<0.001). Overall agreement was poor between wrist and direct observation (kappa= -0.07), hip and direct observation (kappa= -0.04), and wrist and hip (kappa=0.25). Wrist accelerometer placement recorded less sedentary behavior (p<0.001) and more MVPA (p<0.001) compared to hip accelerometer placement. CONCLUSION: Current accelerometer algorithms demonstrated poor accuracy in measuring PA intensities during EAT in neurodivergent youth. Further research is needed to develop and validate PA measurement tools specifically for this population and setting. These findings highlight the importance of context-specific validation when assessing PA in unique therapeutic environments.
Communities in ScholarWorks
Select a community to browse its collections.