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Examining the impact of strain-level differences of Gardnerella vaginalis function relevant to vaginal health
No full textBacterial vaginosis (BV) affects up to 30% of women in the United States, increasing risk for preterm birth, infertility, and sexually transmitted infections. A healthy vaginal microbiome is typically considered one dominated by a Lactobacillus spp. These microbes produce lactic acid and hydrogen peroxide which maintain an acidic pH and prevent the growth of pathogenic bacteria. In contrast, the overgrowth of pathogenic bacteria, mainly facultative anaerobes, leads to increased levels of sialidases and ammonia which degrade the protective mucin layer and raise the pH of the vaginal microbiome, leading to BV. The gold standard for BV treatment is antibiotic treatment with either metronidazole (met) or clindamycin. However, Gardnerella vaginalis, one of the most crucial players in BV, exhibits resistance genes to antibiotics in some strains. This resistance contributes to high rates of BV recurrence, often reported as high as ~60% within a year of antibiotic treatment. Antibiotic resistance can be developed through a variety of mechanisms; a more recent non-canonical form is through extracellular vesicle (EV) uptake. Bacterial EVs (bEVs) are lipid-bound nanoparticles that are naturally released by bacteria during external stress or death, participating in microbe-microbe and microbe-host communication. This work demonstrates that clinical and type strain G. vaginalis strains significantly respond to metronidazole treatment and form biofilms differently. In addition, bEVs from a type strain (TS) G. vaginalis strain (175.8 ± 8.1 nm) are larger than bEVs from clinical metronidazole-resistant (MR) G. vaginalis bEVs (157.7 ± 5.8 nm, p = 0.0383) and contain more protein per particle particles (4.07 ± 1.07 µg/108 particles) than metronidazole-susceptible (MS) (0.839 ± 0.160 µg/108 particles, p = 0.0065) and MR (0.961 ± 0.150 µg/108 particles, p = 0.0086) bEVs. While there are no significant metronidazole-level differences in morphology, concentration, or surface charge, MR G. vaginalis bEVs elicited a high inflammatory response (56.40 ± 7.62 pg/mL) in vaginal epithelial cells compared to a negative vehicle control (19.93 ± 1.66 pg/mL, p < 0.0001) and trended higher than its metronidazole-treated (Met-EV) counterpart (36.28 ± 4.05 pg/mL, p = 0.0600), suggesting a functional difference in the bEVs cargoes in microbe-host communication. Investigating how bEVs are affected by metronidazole treatment or strain-level differences advances how microbe-microbe and microbe-host communication play a role in the treatment of BV
Water Scarcity and Inter-Regional Trade in the U.S.: A Multiple Spatial Scale Analysis
No full textWater scarcity is an increasingly pressing challenge in the United States, driven by the compounded effects of climate change, population growth, resource overexploitation, and inadequate management practices. While the U.S. is not typically considered water-stressed, significant regional disparities and localized vulnerabilities highlight the urgent need for comprehensive analyses of water use and management. This study addresses critical research gaps, including the limited scope of existing models, inadequate data resolution, underexplored socioeconomic impacts, and overlooked spillover effects, through a multi-scale evaluation of water use and constraints across the U.S., with a particular focus on California.This study explores the land-water nexus across the U.S., revealing the environmental and economic trade-offs inherent in interregional agricultural trade. Utilizing a state-level multi-regional input-output (MRIO) model, this study uncovers how interstate trade alleviates cropland scarcity in coastal regions while intensifying water scarcity in arid areas like California. The findings emphasize California’s dual role as a land importer and water exporter, highlighting the need for water conservation policies that integrate economic productivity with environmental sustainability.
This study also examines California’s county-level water use dynamics, focusing on inter-county disparities in virtual water flows and the socioeconomic drivers of household water demand. By linking a county-level MRIO model with household consumption data, the study identifies significant inequalities in water footprints across regions and income groups. Higher-income households exhibit larger water footprints due to their increased household consumption, while agriculturally intensive areas like the San Joaquin Valley bear the burden of exporting virtual water to the demand in urbanized regions. These findings underscore the need for equitable and region-specific water management strategies.
Additionally, this study evaluates the economic, employment, and environmental impacts of water constraints in California, particularly in the context of the state’s transition to regulated water management. By employing a water-supply-constrained MRIO model, it assesses the implications of various climate and policy scenarios, highlighting the far-reaching spillover effects of water constraints across California’s interconnected economy. This evaluation framework offers a transferable tool for addressing water scarcity challenges in other water-stressed regions globally.
Collectively, this research advances the understanding of water use and management across multiple spatial scales, providing critical insights for designing sustainable, equitable, and region-specific water policies. By focusing on California as a case study, it sheds light on broader national water challenges and contributes to the development of strategies that promote resilience and sustainability under evolving climate and socioeconomic pressures
DESIGNING INNOVATIVE STRATEGIES FOR SUSTAINABLE MANAGEMENT OF FUSARIUM HEAD BLIGHT IN WHEAT
No full textFusarium Head Blight (FHB), primarily caused by the fungal pathogen Fusarium graminearum, is one of the most economically damaging diseases of wheat worldwide. The overall goal of this dissertation is to establish long-term sustainable strategies for effective and reliable FHB management by leveraging innovative genetic approaches, shortening the generation time to develop FHB-resistant cultivars, and examining the effectiveness of newly released fungicides. While traditional resistance breeding has focused on incorporating resistance (R) genes from diverse germplasm, this research adopts a innovative approach by targeting susceptibility (S) factors to confer resistance. Using MutMap analysis, a key 4.6 Mb region associated with FHB susceptibility was identified on the short arm of chromosome 2D in the widely cultivated wheat variety ‘Jagger.’ Additionally, a conserved FHB-associated region was discovered on the short arm of chromosome 7A in the Chinese Spring background using recombination-independent approaches. Comparative genomic analysis led to the identification and characterization of DMR6 as a susceptibility factor in durum wheat. To address the challenge of the long breeding pipeline in developing FHB resistant cultivars, screening protocol of germplasm under accelerated growth conditions was optimized. Working on the chemical control options for FHB, the fungicide efficacy of a newly released fungicide, Sphaerex, was tested. Collectively, this research provides a robust foundation for developing FHB-resilient wheat cultivars through integrated, innovative, and sustainable approaches
LINKING TRANSIENT CHANGES IN DISSOLVED ORGANIC CHEMISTRY TO WETLAND CARBON EMISSIONS
No full textWetlands form a massive reservoir of soil carbon (C) that is disproportionately impacted by climate change and displays extreme variability in C cycling over different spatiotemporal scales. The biogeochemical pathways underpinning this variability remain a critical knowledge gap due in part to the oversimplification of soil organic matter (SOM) transformations in the wetland rhizosphere. Tidal marshes bordered by forest are of unique concern due to natural gradients in SOM chemistry along the wetland-to-forest transect. In addition to sea level rise, SOM chemistry is regulated by transient shifts in vegetation growth, organic molecular characteristics, and redox conditions. To better understand how these factors influence the correspondence between wetland C emissions and SOM transformations, we incubated soils collected from a tidal marsh dominated by the plant Phragmites australis. This plant is globally distributed and is recognized as a driver of soil C cycling and soil redox perturbations. We measured CO2 and CH4 emissions and characterized SOM transformations with high-resolution mass spectrometry to assess the effects of seasonality (relevant to plant growth in the field), local soil characteristics (based on transect position, relevant to sea level), and soil redox perturbation (analogous to plant radial oxygen loss) on C emissions. Our results suggest that redox modulation by Phragmites, as well as other wetland plants, has the potential to increase C emissions in the field (depending on transect location and seasonality) by stimulating the degradation of high-molecular-weight compounds in SOM. We find that the molecular mass and nominal oxidation state of C (NOSC) in the dissolved fraction are key metrics for understanding general trends in C chemistry and emissions, but variability in CH4 uniquely corresponds to transient changes in carboxylic-rich alicyclic molecules (CRAM). Considering that sea level rise will likely extend Phragmites into new soil zones, our work allows for predictions of how it could affect C cycling in newly invaded soils. This provides deeper mechanistic insight into the C cycle of wetland soils and underscores a need for further investigations of the wetland-to-forest ecotone to help improve landscape and global C models while informing new climate mitigation policies
Reading between the Rungs: Japanese Acrobats and Victorian Britain, 1867 - 1885
No full textThis thesis examines the Victorian reception of Japanese acrobatic troupes from 1867 to 1885. As the first Japanese people with whom many Britons at home had close encounters, Japanese acrobatic troupes shaped Victorian perceptions of Japan, providing a critical case study for understanding how Victorians made sense of themselves in comparison to other people. As Victorians watched the Japanese acrobats on stage, they projected their theories, fears, and desires onto the performers while struggling to fit them into their existing worldviews of race, gender, and empire. In the late 1860s and 1870s, Japanese acrobats complicated Victorians’ self-image as the more ‘evolved’ or ‘superior’ people, but by 1885, Victorians’ uncertainty regarding these acrobats had been replaced with a desire to appropriate and consume them in whatever ways possible
REINFORCING THE VILLAS: SUPPORTING BUENOS AIRES’ INFORMAL SETTLEMENTS
No full textIn Buenos Aires, Argentina the result of economic crises and neoliberal policies has impacted the capital’s infrastructure. Corruption within Argentina has impacted the development of new infrastructure which impoverished communities need for the improvement of their lives. This thesis will explore how a shift from informal settlements to affordable housing and urban spaces can improve quality of life for people living there. In Buenos Aires, 45% of the population live in poverty making informal settlements a means of survival for the impoverished community that live there. These settlements are a collection of self-built infrastructure on the outskirts of the city. These living conditions often lack resources and essential infrastructure, leading to widespread disease, crime, and violence due to limited access to public amenities. This has caused alienation of the inhabitants that live there and has characterized them as the “others” who live in isolation from the formal city. Their ingenuity and resourcefulness can be used as inspiration in the next iteration of informal settlements and connect them into the formal city. These self-built informal settlements have a culture of their own and can bring to light how cities grow and how the settlements can evolve to become a formal part of the city
RECORDING TO REDESIGN: REDESIGNING A SITE USING CAMERA VISION TO OPTIMIZE PEDESTRIAN FLOW
No full textExamining how people interact with public space is an important dimension of design. As technology has advanced, we have used it to capture how people move and interact in public spaces. Harnessing technology allows landscape architects to leverage the power of computers to empower their designs and increase the effectiveness of designed space. This thesis explores two uses of such technologies: using computer vision to explore how students move through a public space and calibrating a microscopic pedestrian flow model based on collected pedestrian traffic data. These technologies are used to show how such a site might be redesigned to make a space more effective. The site that has been selected to do this is the westernmost plaza of McKeldin Mall at the University of Maryland. The site is adjacent to the McKeldin Library and home to the Testudo sculpture
Solid-State Electrolyte Design: Microstructure and Performance
No full textSolid-state batteries hold significant promise for next-generation energy storage devices; however, poor material contact at the cathode/electrolyte interface often impedes their performance by increasing interfacial resistance. To address this issue, solid-state batteries are often manufactured with porous electrodes that dramatically increase interfacial surface area and improve cell kinetics. These porous electrodes often contain complex microstructures whose unique morphologies are determined by the specifics of the manufacturing process, with two popular approaches being tape-casting and, more recently, 3D printing. While the exact relationship between microstructure and performance is not completely understood, cell performance can be predicted numerically through the use of 3D electrochemical-transport simulations. These simulations heavily depend on the accuracy of the geometries studied and therefore require high-resolution reconstructions from characterized samples. These characterizations are resource-intensive to obtain, rendering optimization studies of porous microstructures untenable by conventional methods.
This work uses computer-generated microstructures (CGMs) to approximate the microstructures of tape-cast and 3D-printed porous electrodes. While 3D-printed architectures can be modeled with geometric primitives, a stochastic algorithm was created for the synthesis of high-fidelity tape-cast microstructures. This algorithm uses a physics-based molecular simulation that emulates the tape-casting process of multiple media. A rigorous validation suite was developed to assess the faithfulness of these CGMs to several experimental samples characterized with FIB-SEM and X-Ray µCT. An analysis of these microstructures across several geometric parameters (including porosity, specific surface area, tortuosity, etc.) reveals the existence of relationships that are seemingly characteristic to the tape-casting process. An electrochemical-transport model was subsequently developed to predict the performance of tape-cast and 3D-printed solid-state electrolytes. By adjusting the geometric parameters and the applied cycling conditions, this work directly compares the galvanostatic discharge of the cells to further study the impact of microstructure on performance and develop strategies for the manufacture of high-energy porous electrodes
Tethered Tensions, Covert Bonds: Navigating Racial Socialization and AntiBlackness in Multiracial Families
No full textThis dissertation examines how Black-white multiracial families navigate the complex terrain of racial socialization and antiBlackness, revealing how different approaches—some centering Black pride, others celebrating mixedness, and many negotiating both—shape how children understand race, selfhood, and power. Drawing on over sixteen months of intensive family observations and 92 semi-structured interviews with ten multiracial families, this study interrogates how racial messages—rooted in Black pride, mixedness, and whiteness—are transmitted, internalized, and negotiated within multiracial households. It argues that racial socialization in these families is marked by both resistance to and complicity in the reproduction of racial inequality.While Black-centered strategies often foster resilience and a politicized attachment to Blackness, they remain constrained by the continued dominance of whiteness—even within the family. Black mothers, in particular, bear the disproportionate burden of racial socialization, tasked with preparing their children for a racialized world while navigating their proximity to whiteness and racial ambiguity. In contrast, mixedness-centered approaches tend to emphasize individuality, pride in dual heritage, and racial harmony, but often fall into color-evasive frameworks that depoliticize race and obscure structural inequality.
This dissertation argues that whiteness operates not as a neutral backdrop but as an active and pervasive force within multiracial families—shaping whose labor counts, whose experiences are centered, and how racial meaning is constructed and internalized. It reveals how gender, phenotype, and family power dynamics further shape racial identity development—especially the unequal distribution of racial socialization labor, typically shouldered by Black parents.
Ultimately, this study challenges dominant narratives that frame multiracial identity as inherently transcendent or post-racial. Instead, it argues for an intersectional and structural approach to multiracial identity that foregrounds the enduring power of whiteness and anti-Blackness. By centering the operations of whiteness within family life, this dissertation moves beyond celebratory narratives of diversity to underscore the urgent need for racial socialization practices that resist, rather than reinforce, the hierarchies that continue to shape identity, belonging, and politics in a deeply unequal, racialized world.
DEVELOPMENT OF A MULTIMODAL SCREENING APPROACH TOWARDS BORRELIACIDAL COMPOUNDS WITH NOVEL MECHANISM OF ACTION
No full textThis work addresses the unmet need for effective therapies targeting Lyme disease by developing innovative platforms and methods. The research focuses on identifying small
molecules capable of killing Borrelia burgdorferi, the bacterium responsible for Lyme disease,
through parallel target-based and phenotypic screening strategies. Central to this effort is the
investigation of the BbHtrA protein, a chaperone-protease essential for bacterial virulence, as a
promising therapeutic target. We establish workflows for the expression, purification, and
biophysical characterization of BbHtrA, alongside novel assay platforms to screen for modulators
of its activity. A critical contribution of this work is the development of orthogonal assays for hit
validation, ensuring the robustness of identified lead compounds. We also develop and optimize
Borrelia viability screening assays, including luciferase-based and orthogonal assays, to identify
borreliacidal compounds with several orders of magnitude stronger potency than those in the
prior art. This research represents a comprehensive effort to advance early-stage drug discovery
for Lyme disease, addressing current therapeutic limitations while introducing new tools, assays,
and insights to the field