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: Directions for submissions can be found in this guide. Please email scholarworks@library.umass.edu if you have any questions.

Request forms for campus-only items are functional. If you do not receive a reply to a submitted request, please email scholarworks@library.umass.edu.

Please see our ScholarWorks guide for more information about submitting your work to ScholarWorks.

Featured Items

UMOP 42: Historical reflections in celebration of the 50th Anniversary of UMass Linguistics

UMOP 42: Papers in celebration of the 50th Anniversary of UMass Linguistics

SNAP Workers: Working People & SNAP Benefits in Massachusetts

Kerrissey, Jasmine; Meyers, Nathan

Established by the Food Stamp Act in 1964, SNAP is the country’s largest anti-hunger program. SNAP, the Supplemental Nutrition Assistance Program, also known as food stamps, provides food assistance to low-income families. The program serves over 41 million people, or 12.3% of U.S. residents. Massachusetts has a higher SNAP rate than the U.S, with 16% of the Massachusetts population receiving SNAP. This report examines workers in Massachusetts who live in households that receive SNAP benefits. The analyses use data from the American Community Survey (ACS), a representative survey administered by the Census Bureau. The report examines the most recent and comprehensive available ACS data, 2019-2023. See the methodological appendix for details.

2025-11-24

Recent Submissions

Open Access
Species Separation Induced by Difference in Accommodation Coefficients
(2025-07-01) Lotfian, Ali; Roohi, Ehsan
The present investigation examines an innovative method for improving the efficiency of thermal separation of binary gas mixtures in a parallel plate configuration. The Direct Simulation Monte Carlo (DSMC) approach was employed for precisely modeling flow in rarefied regimes at micro-scales. The study explores separating a 50%-50% heliumxenon mixture between two plates, highlighting the potential of using specular and diffusive surfaces to generate effective separation flows. We investigated the influence of Knudsen numbers (Kn), specifically Kn=0.05, 0.1, 0.5, and 1, by analyzing temperature, velocity, and molar fraction distributions. In this configuration, the temperature gradient is 600 K, with distinct thermal properties on the upper and lower walls, the latter equally divided between specular and diffusive surfaces. Key aspects include enhancement of flow field dynamics and species separation efficiency through non-mechanical geometries leveraging ambient heat and surface property variation. Observations reveal that helium accumulates along the hot wall while xenon collects along the cold wall due to opposing diffusive velocities.
Open Access
Iran’s Great Scientific Divergence: Counterfactual Evidence for the Long-Term Shock of the 1979 Revolution
(2025-12-05) Roohi, Ehsan
This study quantifies the long-term impact of the 1979 Iranian Revolution on Iran’s trajectory of scientific publications, a critical examination for science and public policy. Using comprehensive data from 1960 to 2024, we benchmark Iran against pre-revolutionary peers (e.g., South Korea) and employ multidimensional scientometrics, including the rigorous Synthetic Control Method (SCM). Results demonstrate a significant divergence: Iran, which led its peers in 1978, experienced collapse and stagnation (1980–1999) while peers grew exponentially. SCM, which optimally matches pre-1979 Iran with South Korea, quantifies a cumulative knowledge deficit of approximately 551,000 publications by 2024. Furthermore, despite a post-2000 volume recovery, a persistent quality gap exists; research impact (measured by Field-Weighted Citation Impact) consistently lags behind the global average. This analysis provides a robust, data-driven quantification of the generational opportunity cost of the 1979 disruption on national scientific development.
Open Access
A computational approach for modeling platelet adhesion dynamics on thrombogenic surfaces
(2025-10-01) Lotfian, Ali; Roohi, Ehsan
Platelet adhesion and aggregation are essential for primary hemostasis, forming a clot that quickly stops initial bleeding. Despite this critical role, the dynamic interactions of platelet receptors with exposed collagen and von Willebrand factor (vWF) at the injury site and how these interactions influence thrombus formation under varying blood flow conditions are not fully understood. This study aimed to investigate the mechanisms of platelet adhesion and aggregation on collagen- or vWF-coated surfaces numerically. We combined the stochastic Bell's law with a deterministic elastic force featuring a time-dependent coefficient within the context of a dissipative particle dynamics (DPD) model to simulate thrombosis formation numerically. Our simulation results revealed that the numerically predicted platelet adhesion patterns closely matched experimental observations reported in the literature, demonstrating accurate replication of platelet behavior on collagen- and vWF-coated surfaces. Consequently, our deterministic/stochastic force model in DPD provides valuable insights into platelet adhesion dynamics under different flow conditions. These results contribute to a deeper understanding of platelet dynamics and potential therapeutic targets for managing hemostatic disorders.
Embargo
Investigating Synaptopathic Mechanisms in ASD and Schizophrenia Patient Derived Induced Neurons
(2025-09) English, Jay
Neurexin 1 (NRXN1) is a synaptic adhesion molecule which is highly conserved evolutionarily. Heterozygous copy number variants in the NRXN1 gene wherein large deletions are present are associated with a variety of neurodevelopmental disorders (NDDs) including autism spectrum disorder (ASD) and schizophrenia (SCZ). NRXN1 is essential for synapse specification and function, which ultimately contributes to the balance of excitatory to inhibitory signaling (E/I ratio) in the brain. E/I signaling is thought to be a pillar of ASD pathology, but to date limited human models of ASD have been studied, and animal models may not fully recapitulate human pathology as there are several distinctions between human brains and those of common workhorse animal models. To address this here, novel ASD patient induced pluripotent stem cells (iPSCs) were sex matched with control iPSCs and differentiated into 2D neuronal cultures containing 80% glutamatergic induced neurons (Ngn2 iNs) and 20% GABAergic neurons (A/D iNs) on mouse glia. Synaptic signaling deficits were then compared across ASD and SCZ NRXN1 CNV carrier patient lines. ASD models uniquely exhibited increased glutamatergic signaling with evidence of dysregulated mitochondrial and ribosomal activity, elucidating disorder-specific pathological drivers of ASD.
Embargo
The Forgotten Men: African and Colored Servicemen of the Second World War and the Rise of African Nationalism in Southern Rhodesia (Colonial Zimbabwe), c.1939-1980.
(2025-09) Chikumbu, Anotida
This dissertation examines the role played by the Second World War in rise of African nationalism. It specifically examines the mobilization, recruitment, wartime, demobilization, and post-war experiences of African and Colored servicemen who participated in the war from Southern Rhodesia (Colonial Zimbabwe). It examines how their experiences revived African nationalism from the 1940s to the late 1970s. It argues that the war engendered political awareness, anti-colonial sentiments, attitudes, and eventually political activity that aided the rise of African nationalism and the attainment of its goals in Southern Rhodesia. The bulk of the material for this dissertation was obtained from archival sources, written family records and oral interviews.

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