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Evaluating fault displacement-length scaling during Pliocene extension across the Saline Range, eastern California
Get PDFNormal faults developed in the brittle crust provide useful measurements for evaluating tectonic extension in a region. Maximum displacement is proportional to trace length in normal faults, characterized by a linear scaling relationship observed across 8 orders of magnitude where the maximum displacement is approximately 3% of the fault length. The Saline Range in eastern California provides an ideal site to assess displacement-length scaling in normal faults, as distributed faulting during NW-directed extension have displaced extensive basaltic lavas in the Saline Valley volcanic Field. These flows range in age from 1.4 to 3.7 Ma and provide a relatively uniform, low-relief surface from which to measure fault slip during the Pliocene. Using high-resolution digital topography derived from airborne photogrammetry, I evaluate displacement along normal faults by reconstructing the topographic surfaces of volcanic flows preserved in both the hanging wall and footwall blocks in the Saline Range.Master of Scienc
POWER IN THE SHADOWS: HOW INSTITUTIONAL POWER SHARING SHAPES THE USE OF AUTOCRATIC DIGITAL REPRESSION
Get PDFIn the 21st century, authoritarian regimes have increasingly adopted pseudo-democratic institutions and decreased physical repression to legitimize their rule. The institutionalization of autocracies and co-optation of the opposition has limited indiscriminate political violence, but it has increased the use of digital repression to preserve regime stability. This study will unlock the internal dynamics of authoritarian regimes as an explanatory tool for the use of digital repression. It analyzes how variations in power sharing institutions impact the use of digital repression tools to legitimize authoritarian power.This study finds that variation in authoritarian institutions leads to alternating uses of digital repression. The mandatory inclusion of minority groups into the government decreases the use of digital repression while the decentralization of regional powers and the adoption of civil protections increase digital repression in autocracies. However, the predicted relationship between institutions and digital repression varies according to a regime’s civil liberty protections.Master of Art
MOLECULAR DESIGN AND SOLUTION BEHAVIOR OF RIGID AND SEMI-RIGID SULFONATED, ALL-AROMATIC POLYAMIDES
Get PDFThis dissertation investigates rigid and semi-rigid sulfonated, all-aromatic polyamides (sulfo-aramids) to explore the structure-property-processing relationships that govern the self-assembly and solution behavior of these high-performance materials. The lyotropic rodlike sulfo-aramid poly(2,2’-disulfonyl-4,4’-benzidine terephthalamide) (PBDT) provides a synthetic model system to explore polyelectrolyte design rules. Our findings reveal that PBDT generates rigid and rodlike polyelectrolyte structures in water—similar to some biological systems. As a function of ionic strength, the rodlike structure and associative interactions of PBDT reveal viscosity solution scaling and correlation length values that deviate significantly from polyelectrolyte models. As a function of effective rod-length and end-group identity, PBDT undergoes rapid and irreversible shear-induced gelation at polymer loadings as low at 7.0 wt%, wherein carboxylic acid-terminated chains reduced the solution-to-gel time. Additionally, the synthesis of the semi-rigid regioisomer poly(2,2’-disulfonyl-4,4’-benzidine isophthalamide) (PBDI)—as a homo- and co-polymer derivative of PBDT—further demonstrates a transition from rodlike to semi-rigid behavior, marked by suppressed liquid crystallinity and an altered shear response. The incorporation of PBDT and PBDI into polymer-reinforced geopolymer composites provides additional insights into the applications of sulfo-aramid materials as rheological modifiers. In summary, the findings in this thesis reveal the potential of sulfo-aramids as synthetic model systems to explore the bottom-up design of rigid and semi-rigid polyelectrolytes for advanced materials applications.Doctor of Philosoph
Preferences for HIV pre‐exposure prophylaxis among men who have sex with men and trans women in 15 countries and territories in Asia and Australia: a discrete choice experiment
Get PDFIntroduction Scaling up pre‐exposure prophylaxis (PrEP) for HIV among men who have sex with men (MSM) and transgender women (TGW) in the Asia‐Pacific region has been slow. We identified the drivers of PrEP use and forecasted PrEP uptake given different PrEP programmes for MSM and TGW living in 15 countries and territories in Asia and Australia. Methods Separate online discrete choice experiment surveys for MSM and TGW were distributed in 15 Asian countries and territories and Australia between May and November 2022. We used random parameters logit models to estimate the relative importance of service attributes and predicted PrEP uptake for different programme configurations. Results Among 21,943 participants included in the MSM survey and 1522 in the TGW survey, the mean age was 31.7 (±9.5) years and 28.1 (±7.0) years, respectively. Cost emerged as the primary driver of PrEP use for MSM and TGW across countries, followed by the type of PrEP. When switching from the least preferred PrEP programme (i.e. very high service fee, PrEP implant, rare kidney problems as side effects of PrEP and a 2‐monthly clinic visit) to an optimal programme (i.e. free access to PrEP via peer‐led community clinics which offered sexually transmitted infection [STI] testing, and a 6–12 monthly visit), the predicted PrEP uptake could improve by over 50% for MSM in Australia, China, Hong Kong SAR China, Japan, the Philippines, Taiwan (China) and Thailand, and 37% for TGW. Compared to those at lower risk of HIV, free access was more preferred by MSM at a higher risk of HIV, while telehealth was more preferred by TGW at a substantial risk of HIV. Conclusions Tailoring services to local contexts, including ensuring affordability, preferred type of PrEP and providing differentiated services, could accelerate the uptake of PrEP among MSM and TGW in Asia and Australia. Novel innovations, such as STI and HIV self‐testing, should be explored as alternatives to conventional testing, given that most MSM and TGW prefer less frequent clinic visits and long‐acting PrEP options
Life‐years lost associated with mental disorders in people with HIV: a cohort study in South Africa, Canada and the United States
Get PDFINTRODUCTION: People with HIV (PWH) have a high burden of mental health disorders, which contribute to increased mortality due to elevated rates of physical illness, suicide or fatal accidents. Additionally, mental health disorders can adversely affect antiretroviral therapy (ART) adherence, leading to increased HIV-related mortality. This study aims to quantify the difference in mortality between PWH who have a mental health disorder and PWH without mental health disorders in South Africa (SA) and North America (NA). METHODS: This cohort study includes PWH aged 18 years or older who initiated ART between 2000 and 2021 at a national private-sector HIV programme in SA and 13 programmes in the United States and Canada. Mental health disorders were diagnosed according to ICD-10 codes F10-F99, which include psychotic disorders, bipolar disorders, depression, anxiety and substance use disorders. We estimated life-years lost (LYL) associated with mental health disorders, quantifying the average difference in remaining life expectancy between individuals diagnosed with a mental health disorder and those without such diagnoses. RESULTS: The study included 119,785 participants from SA (57.4% female, median age 39 years) and 142,044 from NA (85.0% male, median age 43 years). In SA, 57,999 (48.4%) were diagnosed with a mental health disorder, compared with 93,518 (65.8%) in NA. In SA, the LYL associated with any mental health disorder were 3.42 years (95% CI 2.42-4.28) in males and 2.95 years (0.67-5.95) in females. Corresponding figures for NA were 4.16 years (3.71-4.59) in males and 4.64 years (2.93-6.05) in females. In both regions, LYL were higher for psychotic and substance use disorders than for depression and anxiety. Losses were primarily due to natural deaths at CD4 counts ≥200 cells/µl, with considerable contributions at CD4 counts <200 cells/µl. Unnatural causes also contributed to the loss of life-years in males from SA and males and females from NA. CONCLUSIONS: PWH affected by mental health disorders experience higher mortality, primarily from natural causes. LYL were associated with both immunosuppression and higher CD4 levels. Improved management of HIV and physical comorbidities among PWH affected by mental health disorders may enhance their prognosis
Pathway polygenic risk scores (pPRS) for the analysis of gene-environment interaction.
Get PDFA polygenic risk score (PRS) is used to quantify the combined disease risk of many genetic variants. For complex human traits there is interest in determining whether the PRS modifies, i.e. interacts with, important environmental (E) risk factors. Detection of a PRS by environment (PRS x E) interaction may provide clues to underlying biology and can be useful in developing targeted prevention strategies for modifiable risk factors. The standard PRS may include a subset of variants that interact with E but a much larger subset of variants that affect disease without regard to E. This latter subset will dilute the underlying signal in former subset, leading to reduced power to detect PRS x E interaction. We explore the use of pathway-defined PRS (pPRS) scores, using state of the art tools to annotate subsets of variants to genomic pathways. We demonstrate via simulation that testing targeted pPRS x E interaction can yield substantially greater power than testing overall PRS x E interaction. We also analyze a large study (N = 78,253) of colorectal cancer (CRC) where E = non-steroidal anti-inflammatory drugs (NSAIDs), a well-established protective exposure. While no evidence of overall PRS x NSAIDs interaction (p = 0.41) is observed, a significant pPRS x NSAIDs interaction (p = 0.0003) is identified based on SNPs within the TGF-β/ gonadotropin releasing hormone receptor (GRHR) pathway. NSAIDS is protective (OR=0.84) for those at the 5th percentile of the TGF-β/GRHR pPRS (low genetic risk, OR), but significantly more protective (OR=0.70) for those at the 95th percentile (high genetic risk). From a biological perspective, this suggests that NSAIDs may act to reduce CRC risk specifically through genes in these pathways. From a population health perspective, our result suggests that focusing on genes within these pathways may be effective at identifying those for whom NSAIDs-based CRC-prevention efforts may be most effective
GENDER IDENTITY AND THE CULTURAL CLEAVAGE: HOW TRADITIONAL, AUTHORITARIAN, AND NATIONALIST POLITICAL GROUPS OPPOSE TRANSGENDER AND GENDER NON-CONFORMING RIGHTS IN THE EUROPEAN PARLIAMENT
Get PDFThis thesis explores how Members of the European Parliament (MEPs) from the Traditional, Authoritarian, and Nationalist (TAN) groups, the European Conservatives and Reformists (ECR) and Identity and Democracy (ID), opposed Transgender and Gender Non-Conforming (TGNC) rights during the 9th European Parliament (EP) 2019–2024, and how this opposition was perceived by other MEPs. Applying neo-cleavage theory, with insights from homonationalism and trans-exclusionary radical feminism, three thematic analyses were conducted using plenary debate and interview data. The analysis identified six central themes, TGNC rights as ideological imposition, minimized as irrelevant, opposed at the EU level for national sovereignty, framed as indoctrination of children, described as threatening cisgender women, and among ID MEPs linked to anti-immigration narratives. ECR MEPs frequently used ideologically based arguments, and ID MEPs expressed more populist and xenophobic language. Interviews confirmed these patterns and highlighted the growing influence of TAN groups after the 2024 EU elections.Master of Art
Human fecal markers in environmental waters and association with indicators of human and rodent infections in urban Salvador, Bahia, Brazil
Get PDFThis study explores the use of human mitochondrial DNA (mtDNA) markers, specifically hCYTB484, as fecal source tracking (FST) tools for environmental surveillance in a high-density, low-income community in Salvador, Bahia, Brazil. Here, we hypothesized that hCYTB484 concentrations in wastewater would correlate with indicators of human pathogen exposure, such as viral antibody prevalence and helminth infections in rodents, both of which are potential zoonotic threats. Our study found that higher concentrations of mtDNA in wastewater were associated with increased viral exposure in humans and the presence of helminths in rodents. This suggests that fecal mtDNA could serve as a promising tool for environmental surveillance of pathogens in vulnerable communities. Our findings underscore the potential of mtDNA markers to be integrated into disease monitoring systems, particularly in resource-limited urban areas with inadequate sanitation. Implementing mtDNA-based tracking in environmental waters could strengthen early-warning systems for public health, allowing for a more proactive response to emerging health threats. Further research is needed to deepen our understanding of pathogen circulation and inform more effective public health interventions
“Who’s gonna take care of my babies?” the impact of children on treatment decisions for women with metastatic breast cancer: a qualitative analysis
Get PDFBackground Few studies have explored the impact that children—and grandchildren—have on treatment decisions in metastatic breast cancer (mBC). This study examined whether or not being a parent or grandparent influences treatment decisions. Methods A qualitative sub-analysis was conducted with a purposive, diverse sample of 13 women with mBC in the Southeastern United States. Semi-structured interviews explored treatment decision-making, patient values, and patient-clinician communication. Transcribed interviews were analyzed using thematic analysis by three independent coders to identify recurrent themes. Results Nearly half (n = 6, 46%) of participants were women of color, and 12 had children. Seven themes emerged as key factors in treatment decision-making, with five participants identifying children and grandchildren as critical. Other common factors included side effects (n = 7, 54%) and quality of life (n = 6, 46%). Among participants with children and grandchildren, body image emerged as a subtheme. For those prioritizing quality of life and managing side effects, children provided emotional support and assistance with daily activities. Conclusions Children and grandchildren significantly influenced treatment decisions, rivaling quality of life and side effects as critical factors. This influence varied by life stage, with younger mothers prioritizing treatment efficacy and older women valuing quality of life and emotional support. Our results demonstrate that continuous shared decision-making is crucial as treatment preferences evolve and are influenced by familial roles and disease progression. Implications Future tools should include an assessment that integrates family and children. This approach can better support survivors in aligning treatment with their values and familial priorities
Navigating Identity in Substance Use: From Disclamation to Reclamation
Get PDFPresentation delivered to students of ANT 3930 at the University of Florida on November 13, 2025. Reviews theory and empirical research on social identity in people who use drugs