DRUM - Digital Repository at the University of Maryland

DRUM collects, preserves, and provides public access to the scholarly output of the university. Faculty and researchers can upload research products for rapid dissemination, global visibility and impact, and long-term preservation.

 
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Equitable Access Policy

Equitable Access Policy

The University of Maryland Equitable Access Policy provides equitable, open access to the University's research and scholarship. Faculty can learn more about what is covered by the policy and how to deposit on the policy website.
Theses and Dissertations

Theses and Dissertations

DRUM includes all UMD theses and dissertations from 2003 forward.

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Recent Submissions

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Electronic Supporting Data: Tetrachloroanthracene Walled Glycoluril Dimer Undergoes Self-Association and 1:1, 2:2, and 1:3 Host•Guest Binding
(Taylor & Francis, 2026-01-01) Hornstein, Noah; Perera, Suvenika; Shaurya, Alok; Isaacs, Lyle; Isaacs, Lyle
We report the design, synthesis and characterization of a tetrachloroanthracene walled methylene bridged glycoluril dimer (H1). According to 1H NMR spectroscopy and symmetry considerations we formulate H1 as a C2v-symmetric monomer in DMSO but it exists as a C2h-symmetric dimer (H1•H1) in water. The H1•H1 dimer persists below 25 uM in water and displays high thermodynamic stability (Ks ≥ 1.8 x 106 M-1). H1•H1 is also stable up to 70 ˚C in water. We investigated the binding of H1 with a panel of five dyes by isothermal titration calorimetry and 1H NMR spectroscopy and found that H1 engages with dyes with several different stoichiometries of binding. For example, NMeAc and Berb are capable of causing the dissociation of H1•H1 resulting in the formation of the 1:1 intracavity dye complexes H1•NMeAc and H1•Berb. In contrast, Rh6G and ThT do not dissociate the H1•H1 dimer and instead stack on the exterior of the dimer to form Rh6G•H1•H1•Rh6G and ThT•H1•H1•ThT, respectively. Finally, 3 equivalents of NDI+ causes dissociation of H1•H1 and binds both intracavity and on the exterior to form the H1•(NDI+)3 complex.
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STALLED CONVERGENCE: RACE, GENDER, AND SECTOR IN AMERICAN MANAGERIAL ACCESS AND EARNINGS, 1960-2021
(2025) Willow, Moriah; Cohen, Philip N; Sociology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This study contributes to sociological research on inequality in managerial employment by analyzing patterns of access and compensation across race, gender, and sector using harmonized IPUMS Census and American Community Survey microdata from 1960 to 2021. The analyses model relative odds of attaining managerial positions and decompose wage disparities among managers by decade using consistent occupational definitions, examining disparities for Black women, Black men, and White women relative to White men, with separate analyses by public and private sector.Three patterns emerge. First, wage convergence stalled or reversed after 2000 for African Americans, while White women continued progress. Black women's wages stagnated at 0.48 log points below White men (62 cents per dollar) in private sector from 2000-2021, while their public sector gap remained flat at 0.29-0.31 log points. Black men experienced wage regression: private sector gaps increased from 0.33 to 0.44 log points, and public sector gaps rose from 0.19 to 0.22 log points. White women continued modest gains, with gaps narrowing from 0.36 to 0.26 log points (private) and 0.26 to 0.21 log points (public). Second, substantial sectoral differences persisted. In 2021, Black women's access gap was 1.5 percentage points in public versus 6.8 points in private; Black men's was 2.1 versus 8.5 points; and White women's was 0.9 versus 1.1 points. Wage gaps were consistently smaller in public sector: Black women earned 0.29 log points less than White men versus 0.48 in private, Black men's gaps were 0.22 versus 0.44 log points, and White women's were 0.21 versus 0.26 log points. Third, gap composition shifted fundamentally. Educational differences between groups explained access gaps from 63% to 24% for Black men and 45% to 15% for Black women in private sector. Industry segregation and marital status differences emerged as primary explanatory factors, together explaining 40% of Black women's access gap by 2021. Coefficients effects increased substantially, reaching 94% for White women, 63% for Black women, and 55% for Black men in private management.
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Vaginal bacteria-derived extracellular vesicles diffuse through human cervicovaginal mucus to enable microbe-host signaling
(npj, 2025) Steinman, Darby; Zierden, Hannah
The composition of the vaginal microenvironment has significant implications for gynecologic and obstetric outcomes. Where a Lactobacillus-dominated microenvironment is considered optimal, a polymicrobial environment is associated with increased risk for female reproductive diseases. Recent work examined bacteria-derived extracellular vesicles (bEVs) as an important mode of microbe-host communication that may influence reproductive outcomes. However, in order to communicate with female reproductive tissues, bEVs must penetrate the protective cervicovaginal mucus barrier. We demonstrate increased diffusion of bEVs compared to whole bacteria. Additionally, we evaluate the uptake of bEVs by, and the resulting effects on, human vaginal epithelial, endometrial, and placental cells, highlighting potential mechanisms of action by which vaginal dysbiosis contributes to gynecologic and obstetric diseases. Taken together, our work demonstrates the ability of bEVs to mediate female reproductive outcomes and highlights their potential as therapeutic modalities for treating dysbiosis and dysbiosis-associated diseases in the female reproductive tract.
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Testudog: Autonomous Quadruped Robot for Unstructured Terrain Navigation
(2025) Mudda, Arjun; Moradi, Arian; Jayanthi, Saiarun; Sridhar, Krish; Akin, David
Robotic autonomy is a field that has attracted significant interest, as robots become more capable of independent problem-solving. Quadruped robots have risen in popularity for their ability to navigate complex terrain. However, robust autonomous navigation, especially through unknown and variable environments, remains a challenge. Platforms like Spot from Boston Dynamics are currently being deployed for a diverse range of commercial purposes, but often possess a significant upfront cost. To address these challenges, Robotics at Maryland (R@M), the University of Maryland's largest competitive student robotics group, has been developing Testudog. Testudog is a quadruped robot platform that seeks to provide a low-cost and fully autonomous navigation solution. Built completely from scratch, Testudog features a lightweight, 3D-printed frame with four modular legs, actuated by Quasi-Direct Drive motors and capable of 12 degrees-of-freedom movement. With advanced control systems, integrated torque sensing, and terrain-mapping sensors, Testudog aims to deliver an autonomous quadruped platform competitive with commercial systems, while remaining affordable through the use of modular, resourceful, and robust design strategies.