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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Submit to DRUM

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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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    A Multiplex RT-LAMP-Lateral Flow Platform For Comprehensive Dengue Serotype Detection
    (2026-07) Darcheva, Alina; Dejene, Nuhamin; Hackel, Davis; Kim, Christine; Potter, Maya; Hilton, Shannon; Spirito, Catherine
    Dengue virus (DENV) is a mosquito-borne RNA virus responsible for approximately 400 million infections annually and exists as four distinct serotypes (DENV-1-4). Secondary infection with a different serotype significantly increases the risk of severe dengue, making rapid serotype differentiation critical. Current gold-standard methods, such as reverse transcription polymerase chain reaction (RT-PCR), require expensive equipment and centralized laboratories, limiting accessibility in resource-limited settings. This project aims to develop a low-cost, portable diagnostic platform that combines reverse transcription loop-mediated isothermal amplification (RT-LAMP) with a multiplex lateral flow assay (LFA) for rapid detection and differentiation of all four dengue serotypes. Serotype-specific primers are being designed and optimized for RT-LAMP. A portable heating device utilizing a fatty acid phase change material (PCM) and an Mg-Fe alloy reaction was successfully constructed to provide instrument-free amplification. The LFA mechanism was also validated by successfully immobilizing the control capture probe, demonstrating effective salt-mediated immobilization, a clear colorimetric response, and successful biotin-mediated gold nanoparticle capture. Initial testing with synthetic DENV-2 DNA demonstrated successful RT-LAMP amplification. These findings establish the feasibility of an inexpensive, field-deployable RT-LAMP-LFA platform with potential to improve early dengue diagnosis and outbreak surveillance in resource-limited settings.
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    Utilizing RNase J1 to Degrade Ribozyme Reporter Signal in Cell-Free Systems
    (2026) Saafan, Umme Hani; Kongne, Jodelle Nembot; Herbert, Alexandra; Dugan, Pierre; Spirito, Catherine
    Ribozymes are noncoding RNAs that are able to catalyze reactions, such as self-cleavage, and can be used to control the expression of downstream genes under specific conditions. In E.coli-based cell-free protein expression systems, native RNases cannot efficiently degrade transcripts generated following ribozyme self-cleavage. Exogenous ribonuclease RNase J1, from Bacillus subtilis, can selectively degrade RNA transcripts containing a 5’ hydroxyl group, and could potentially be used to turn off the expression of downstream fluorescent reporters. In this study, we designed cell-free reactions (CFRs) containing a Pistol self-cleaving ribozyme upstream of the fluorescent reporter deGFP. Pistol ribozyme reporter constructs were PCR amplified, cleaned, and quantified. RNase J1 was expressed in E.coli-based cell-free lysates and its expression was evaluated by an SDS-PAGE gel and Western blot. One-pot and two-pot CFR setups were used to evaluate the effect of RNase J1 on reporter fluorescence. Although RNase J1 expression was successfully detected, fluorescence measurements demonstrated high variability across experiments. Pistol reporter constructs produced fluorescence levels close to the negative control, making decreases attributable to RNase J1 difficult to distinguish, and RNase J1 did not consistently reduce reporter fluorescence under the conditions tested. Future work should optimize reporter fluorescence to improve signal above the background, repeat experiments to evaluate reproducibility, and investigate the effects of native RNases present in the cell-free lysate. If successful, this system could be adapted to ligand-responsive ribozyme reporters, allowing for the development of ribozyme-based biosensors for a variety of target molecules.
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    Getting Ahead of Small Business Displacement: Strategies for the Early Stages of Gentrification
    (Small Business Anti-Displacement Network, 2026-02) McManus, Sophie; Lung, Willow; June-Friesen, Katy
    This report examines how commercial gentrification unfolds in its earliest phases and identifies practical strategies to prevent displacement. Drawing on focus groups, conference sessions, and webinars with members of the Small Business Anti-Displacement Network (SBAN), as well as a review of existing research, this report finds that the earliest signs of gentrification appear long before the characteristics typically associated with gentrification, such as rising rents, an influx of higher-income residents, and physical redevelopment. Instead, early signals of gentrification are identifiable in long-term patterns of disinvestment, redevelopment planning decisions, and regulatory changes that quietly reshape neighborhoods.
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    Global Oceans
    (American Meteorological Society, 2024) Johnson, G.; Lumpkin, R.; Alexander, Michael; Amaya, Dillon; Beckley, Brian; Boyer, Tim; Bringas, Francis; Carter, Brendan; Cetinić, Ivona; Chambers, Don; Chan, Duo; Cheng, Lijing; Dong, Shenfu; Elipot, Shane; Feely, Richard; Franz, Bryan; Fu, Yao; Gao, Meng; Garg, Jay; Giglio, Donata; Gilson, John; Goes, Marlos; Graham, Garrett; Hamlington, Benjamin; Hobbs, Will; Hu, Zeng-Zhen; Huang, Boyin; Ishii, Masayoshi; Jacox, Michael; Jersild, Annika; Jevrejeva, Svetlana; Johns, William; Killick, Rachel.; Kuusela, Mikael; Landschützer, Peter; Leuliette, Eric; Liu, Chao; Locarnini, Ricardo; Lozier, Susan; Lyman, John; Merrifield, Mark; Mishonov, Alexey; Mitchum, Gary; Moat, Ben; Nerem, R.; Oe, Mitsuho; Perez, Renellys; Pita, Ivenis; Purkey, Sarah; Reagan, James; Sato, Kanako; Schmid, Claudia; Smeed, David; Smith, Ryan; Stackhouse, Paul; Sukianto, Thea; Sweet, William; Thompson, Philip; Triñanes, Joaquin; Volkov, Denis; Wanninkhof, Rik; Weller, Robert; Westberry, Toby; Widlansky, Matthew; Willis, Josh; Yin, Xungang; Yu, Lisan; Zhang, Huai-min
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    Supporting Movie files for Fuel-Driven Rapid Swelling and Shrinking in Porous Hydrogels
    (2026) Rath, Medha; Wood, Jemma; Srivastava, Satyam; Battumur, Sarangua; Mazurkiewicz, Alicja; Raghavan, Srinivasa R; Woehl, Taylor J; Woehl, Taylor J
    Biological systems are known for their transient and autonomous responses, such as muscle actuation and cell division. Soft materials that mimic these responses have been investigated, with examples including materials that actuate or morph when exposed to chemical fuels. However, their reconfiguration times extend to tens of hours, which is 10 to 100 slower than biological systems. Here, for the first time, we demonstrate autonomous responses (swelling and shrinking) in porous hydrogels that occur in < 1 h. The gels are crosslinked networks of acrylic acid and acrylamide copolymers containing ~100 µm interconnected pores. When a carbodiimide chemical fuel is added to swollen gels, anionic carboxylates are converted to nonpolar anhydrides, causing the gels to shrink by ~50% in 5 min. The anhydrides then spontaneously hydrolyze and revert to their anionic form, causing the gels to autonomously reswell in < 1 h. The reswelling time increases with decreasing porosity and increasing fuel concentration. We show that rapid gel shrinkage upon fuel exposure occurs via convective water transport out of pores, while reswelling occurs via rapid bulk hydrolysis of anhydrides. This work thereby uncovers general mechanisms for quickening the response of soft materials to chemical triggers.