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Examining the Effect of Peers on Internalized Substance Use Stigma in the Context of HIV and Substance Use Care Engagement in South Africa
No full textSouth Africa has the most people living with HIV (PWH) in the world and a high burden of substance use disorder (SUD), which is associated with worse HIV care engagement and health outcomes. Internalized substance use stigma is a known barrier to engaging in HIV care and SUD treatment among PWH who use substances. In high-income countries, peer recovery coaches (PRCs), defined as trained lay health workers with lived substance use recovery experience, have been used to help patients who use substances stay better engaged in care, largely due to the assumption that PRCs’ shared lived experience helps reduce patient internalized substance use stigma. Yet, it is unclear if any studies have examined this assumption. Therefore, the first aim of this study was to conduct a scoping review to summarize the state of the research on formal peer workers, like PRCs, reducing substance use stigma globally. Following a systematic search through June 2023, we identified n=16 articles. Of these, only n=2 had a primary aim related to peer workers shifting substance use stigma, and none quantitatively examined internalized substance use stigma. In the second aim, as part of a pilot study, we examined if meeting with a PRC (intervention; n = 23) decreased internalized substance use stigma in comparison to enhanced treatment as usual (ETAU control; n = 24) among PWH who use substances in a resource-limited South African community. We also examined changes in internalized HIV stigma (exploratory). Stigmas were measured with the internalized subscales of the Stigma Mechanism Scales at baseline and three-month follow-up assessments, and data was analyzed using repeated measures ANOVAs. Findings revealed that internalized substance use stigma significantly decreased in both conditions and had no impact on internalized HIV stigma, suggesting that the PRC did not significantly affect either stigma. This dissertation represents a first step in examining whether PRC contact reduces internalized stigma in a low-income setting. To optimally scale PRC roles, future research is needed to evaluate if and when PRCs may reduce stigma and improve health-related outcomes, and how to optimally implement this role in low-resource settings
Closed surface pairs with maximal local rolling symmetries
No full textIn this dissertation, we will explore the relation between the geometry of rolling surfaces and the adjoint split-real form of the exceptional simple Lie group of rank 2. For every pair of Riemannian surfaces whose Gaussian curvatures never coincide, it is known that there is a (2, 3, 5)-distribution on a 5-dimensional configuration space whose elements describe “rolling (without slipping or twisting)” one surface along the other, and (2, 3, 5)-distributions happen to correspond to a specific type of parabolic Cartan geometry whose model group is given by this exceptional simple Lie group. Determining which pairs of surfaces admit “rolling distributions” with maximal local symmetry is a problem of particular interest, and our main result shows that the only such pairs of closed surfaces are those with constant Gaussian curvature in the ratio of either 1:9 or 9:1. Additionally, we present a novel, visual explanation for the well-known 1:3 ratio of radii required for the space of local symmetries for a pair of spheres rolling along each other to have maximal dimension
Neutral and selective drivers of TCR repertoire diversity
No full textThe vertebrate adaptive immune system relies on the immense diversity of T cell receptors (TCRs) and immunoglobulins (IGs) to recognize a wide array of pathogens. Each T and B cell expresses receptors encoded by recombination of gene segments during lympchocyte development. This somatic generation of diversity depends on the germline genes available for recombination and, for TCRs, on interactions with the major histocompatibility complex (MHC). Adaptive immune repertoire diversity enables immune surveillance and protection. In this dissertation, I investigate the evolutionary and selective forces shaping TCR repertoire diversity across multiple levels, from germline gene evolution to repertoire structure, using whole-genome and immune repertoire sequencing across humans, non-human great apes, mice, and bank voles.
First, I examined the evolution of germline TRBV and IGHV gene families in non-human great apes using read-depth-based copy number estimates and McDonald-Kreitman tests. Despite their immunological importance, I found only modest copy number differences across species and limited evidence for lineage-specific expansions or adaptive evolution. V gene allelic variation showed signatures of purifying selection consistent with most protein-coding genes. Together, these results show that V genes in the great apes did not experience diversifying selection despite differing pathogen history and geographic distributions.
Second, I tested the hypothesis that greater MHC diversity within individuals expands the breadth of the TCR repertoire by increasing the number of TCRs that pass thymic selection. Using ecological and network-based diversity metrics in a large human cohort, I consistently found no strong association between MHC diversity and TCR repertoire composition. This surprising null result held across multiple MHC diversity measures and covariate adjustments, and was supported by comparative analyses in bank voles. Despite wide variation in MHC genotypes, most individuals appeared to achieve a similar minimum level of repertoire diversity - suggesting that the immune system generates sufficient diversity.
Finally, by comparing productive (selected) and nonproductive (unselected) TCR sequences in genetically identical mice, I isolated the effects of thymic and peripheral selection. Public TCRs were consistently enriched and more abundant in the naive productive repertoire, showing that selection shapes TCR usage beyond neutral generation biases.
Together, these results suggest that the overall structure of the repertoire is robust to variation in MHC diversity. Moreover, recent evolution of germline V gene content in great apes shows little evidence of adaptive expansion. However, interactions with self-peptides presented by the MHC enhances the abundance of public TCRs. These findings support a model in which the adaptive immune system achieves sufficient diversity through robust, cross-reactive repertoires shaped largely by stochastic processes - downplaying the role of MHC-mediated selection in shaping overall repertoire structure
Naming Breonna Taylor: Revitalizing Black Women’s Memory in Digital Spaces and Urban Landscapes
No full textThis dissertation, Naming Breonna Taylor: Revitalizing Black Women’s Memory in Digital Spaces and Urban Landscapes, interrogates the multilayered practice of remembrance, where the convergence of historical and cultural memories cultivate an active, participatory process that keeps Breonna Taylor’s memory alive and forever-evolving. Each chapter examines acts of remembrance dedicated to Taylor, a 26-year-old Black woman who police officers fatally shot in Louisville during a narcotics investigation on March 13, 2020. Naming Breonna Taylor demonstrates how the racialized and gendered acts of naming Taylor, both in digital spaces and urban landscapes, elevate her to a household name and make her a representative figure for broader issues related to Black womanhood. I construct a Black feminist memory framework (BFMF) to provide an analytical approach that examines the multilayered naming practices for Taylor by various groups, each with different ideological commitments regarding how she is remembered. This framework explores how memory is constructed, made visible, and operates differently when informed by Black feminist scholarship, ideologies, and methodologies. BFMF shapes how researchers collect and analyze acts of remembrance by offering adaptable methods and applying theories to these texts.
The guiding research questions for this dissertation are: How does a Black feminist memory framework illuminate how Breonna Taylor is remembered and memorialized across digital platforms and urban landscapes by Black communities and other stakeholders? To what extent does this framework reveal the tensions between life and death, pleasure and pain, joy and resistance, healing and trauma, and celebration and mourning? To render Black feminist memory as a framework, this dissertation navigates through three case studies between 2020 and 2023 that are associated with the Say Her Name movement. The first chapter examines the #BirthdayForBreonna campaign in 2020 on the social media platforms Twitter and TikTok. This chapter theorizes memory activism to understand how communities remember and honor Black women’s pasts in online spaces. Drawing from Black birthdays and homegoing traditions, I demonstrate how these racial-historical contexts resurface in digital spaces in ways that function rhetorically to sustain the continuity of Black resistance and celebration. The second chapter analyzes the virtual reality exhibit Breonna’s Garden. This virtual garden is a moderated immersive experience on the platform AltspaceVR where participants, represented as avatars, could explore five exhibits dedicated to Taylor. I argue that the cultural production of Breonna’s Garden—through its design, cultural narratives, interactivity, and meaning-making—exemplifies Black technonostalgia. The gardening practices within are rooted in Black homegoing traditions where developers use garden simulations to honor the deceased and engage users in the process of healing and regeneration. The third case study examines eight mural artworks depicting Taylor through the critical lens of Black feminist placemaking. I analyze my experiences visiting each mural through rhetorical field methods and the ArcGIS StoryMap I created titled, The Breonna Taylor Mural Memorial Project. I argue that the physical placement of murals portraying Taylor offers alternative geographies of liberation while resisting the dominant understandings of blackness and womanhood
Artificial Intelligence on the Edge: From Learning to Deployment
No full textAs Artificial Intelligence (AI) has grown in use, so too have the computational, memory, and data resources required to train state-of-the-art AI models. AI models, and the data they are trained on, are traditionally stored centrally, in-house. However, data is increasingly collected by decentralized devices, like smart sensors and mobile phones, which are at the edge of a network. Primarily due to privacy constraints, via impending laws and regulation, it is increasingly difficult to transfer user data from such edge devices to a central, in-house server.
This emerging impediment has spurred interest and research into edge learning, a distributed and collaborative paradigm, where AI models are trained closer to, or on, the devices where data originates. While promising, edge learning faces obstacles to overcome before attaining widespread adoption.
Part I of this dissertation addresses the first obstacle, the ability of participating devices, known as edge devices, to learn AI models. Edge devices lack access to large memory and computational power sources that are common in traditional, centralized settings. To solve these issues, Part I proposes: (i) an asynchronous decentralized edge-learning algorithm that removes the training-time dependence on the slowest device, improving training speed, (ii) a locality-sensitive hashing framework that allows devices, with the help of a server, to train a large-scale AI model without storing the entire model, and (iii) a compressed-sensing algorithm that shrinks the size of both training data and AI models, with minimal performance degradation, while improving training and inference runtime.
Part II of this dissertation addresses the second obstacle, the inability to successfully deploy both fair collaborative edge-learning frameworks and safely trained, compliant AI models. Current edge-learning frameworks lack incentives. Thus, edge-learning participants may not always be incentivized to act in accordance with how the designee intended their frameworks to function, resulting in unfair and unintended outcomes. To solve these issues, Part II proposes: (i) two separate mechanisms to eliminate device free riding, one to incentivize device truthfulness when reporting information to a central server and a second to incentivize greater training contribution than by training alone, and (ii) a rigorous framework for AI regulation that incentivizes devices to both deploy compliant models and participate in the regulation process
STRONG STATE AND COMPLIANT BUSINESSES: HOW CHINA LIBERALIZES ITS FINANCIAL MARKET AND DISTRIBUTES SUBSIDIES
No full textWhy do some domestic firms get more state resources compared to others? I argue that firms use a) political connections and b) strategic behavior to get more subsidies and foreign capital. Data from firms listed in China’s Shenzhen and Shanghai (2008–22) support the argument. In three ways, this dissertation enhances our understanding of China’s political economy. First, it suggests that marketization in China has not led to its assimilation to global neoliberalism. I show that firms who need foreign capital–those without connections and subsidies–receive less foreign capital. Second, I suggest that when the private-state boundary is blurred, party-state capitalism better explains China’s political economy than state-capitalism. I use new measures of connections: firms’ Party committees and amended charters. Third, I show that when connected firms work more in the citizen interest, the state grants them more resources. Scholars have associated political connections with cronyism at the expense of citizens’ interest
“Dark Sousveillance”: Queer Intimacies and Sensorial Registers of Black/white Interraciality
No full text“Dark Sousveillance”: Queer Intimacies and Sensorial Registers of Black/white Interraciality situates Black/white interraciality as a queer form of desire (Cohen 1997; Somerville 2000; Stallings 2015) and as an object of state and interpersonal surveillance (Browne 2015; Moran 2001; Musser 2014; Pascoe 2009; Sexton 2008). Rejecting the conscription of interraciality into the larger, overlapping projects of anti-black surveillance, “knowability” (Browne 2015), sexual normativity, coupling, and state regulation of desire, this dissertation instead asks after the possibilities of interraciality when visuality and biopolitics are decentered, and instead we make space for its full sensorial dimensions (Stallings 2015). Accordingly, this dissertation explores the genres of horror, absurdity, epistolary narrative, poetry, science fiction, and oral history; I examine works of film such as Sally Potter’s Thriller (1979) and Janicza Bravo’s Zola (2020) to consider how the soundscapes of interraciality materialize in unconventional ways through the potentialities of horror and tragicomedy; I explore interracial epistolary narrative as a form of touch in Pat Parker’s archive; and I analyze the oral histories and “strange temporalities” (Halberstam 2005) of interracial comrades engaged in grassroots organizing efforts through the work of D.C.-based multiracial coalition, Roadwork. I take up this project to consider four primary research questions: 1) What does it mean to study interraciality when the concepts of ‘interracial’ and of the ‘couple’ are both fictions (initially created in service of racial capitalism) made up of two separate people? 2) How does interraciality get hailed to perform normativity, and is it possible for interraciality—as a concept and a set of lived experiences—to complicate the couple form? 3) How might witnessing queer interracial intimacies—in varying forms—offer nuance to questions of attachment, encounter, desire? 4) What might Black/white interraciality (re)make or (re)produce outside of biopolitical regimes and how do we feel the interracial in ways beyond visuality
EXAMINING THE INFRASTRUCTURE OF THE WINDSOR RUINS SITE (22CB602) VIA GROUND-PENETRATING RADAR FOR THE METHODS OF COMFORT IN A BURNED ANTEBELLUM PLANTATION MANOR IN MISSISSIPPI
No full textThe Windsor Ruins site (22Cb602) located in Claiborne County Mississippi, was built between 1859 to 1861 by the enslaved population of Smith Coffee Daniell II, supplemented by imported craftsmen. It was built a little over 10 miles from the closest town at the time, Port Gibson, Mississippi. The 17,000 ft2 manor burned down on February 17, 1890, leaving 23 Corinthian columns standing. The fire destroyed most of the records, photographs, and architectural plans of the structure, with the only surviving image being a drawing from a United States soldier discovered in 1990. This thesis examines if ground-penetrating radar (GPR) data collected at the Windsor Ruins site (22Cb602) will establish new understandings of the house by revealing infrastructure that offered methods of modern comfort of the time. From excavations conducted on the site in 1976, it is known that the house contained an elaborate plumbing and cistern system. Eye-witness accounts also indicate that it had full plumbing and a dumbwaiter. A geophysical survey of the site using a 350MHz GSSI UtilityScan ground-penetrating radar unit was conducted in October 2024 using 0.5 m (1.64 ft) spaced unilateral transects. Through the use of the oral historical accounts, combined with past archaeological excavations, the geophysical survey data collected does reveal new aspects of the house and gives prospects of new areas to investigate to broaden our understanding of the manor. This research is expanding and examining the interpretation of the burned manor and hopefully will serve as a launching point into further research of the site, most notably of the enslaved people there, while being repeatable at numerous other burned plantation manor sites in the state
Cataloging computer-generated resources: past, present, and possible future
No full textThe article discusses how catalogers describe resources generated by artificial intelligence and how these resources could be represented in bibliographic records. It briefly reviews the history and current state of computer-generated resources, as well as the concept of authorship in cataloging standards. It then provides an overview of the history of cataloging approaches to non-human authors, including the PCC's recent FAQ on "Cataloging of Resources Generated Using Artificial Intelligence (AI) Software." The article finishes by evaluating the PCC guidance and suggesting a range of alternative and/or additional practices that catalogers could adopt.https://doi.org/10.1080/01639374.2025.251511
Vegetal Imaginaries: Sounding and Sensing Plant Life and a “Re-Enchantment” of the More-than-human World
No full textThis thesis explores how sound and music provide ways of knowing and modes of enacting relationships with plant life. Based on a year of ethnographic and archival research, I examine the practices of two distinct but related populations: people who use electronic tools and instruments to sonify plant life and artists and healers whose numinous experiences of receiving plant messages shape their sonic, healing, and artistic practices. I ask how sensual and sonic experiences with plant life shape participants’ ethical conceptions of interspecies and intrahuman relationships. I examine how conceptions of communicative, psychic, and energetic plants enable imaginaries of unmediated connection to plants and act as modes of “re-enchantment” (Partridge 2004). I argue that my research participants’ sonic and sensual engagements with plant life are communicative encounters that inform their idea of what it means to be human and shape their conceptions of ethical relations between humans and plants. Further, at best, such practices bring humans into relationships of care and attention with the vegetal and, at worst, reinscribe extractive relationships with the more-than-human world