545298 research outputs found
Sort by
Winners, Affective Polarization, and Support for Violations of Democratic Norms
No full textThis dissertation consists of three papers that examine why electoral winners, those who voted for or supported the governing party, are more likely to endorse violations of democratic norms. While electoral victory is typically seen as a positive and healthy outcome that fosters engagement and strengthens partisan ties, it can also have unintended consequences. Specifically, winning an election increases emotional attachment to one’s party, which in turn makes voters more likely to rationalize undemocratic actions as democratic, thereby endorsing norm erosion. The first paper investigates the winner–loser gap in affective polarization, establishing the first causal link in the broader theoretical framework. It shows that electoral victory functions as a form of partisan identity affirmation, heightening in-party favoritism and, as a result, increasing affective polarization. The second paper explores how this increase in in-party favoritism drives democratic rationalization. Using a preregistered survey experiment conducted in the U.S. shortly before the 2024 election, the study finds that the effect of winning on support for norm violations is primarily mediated by heightened in-party favoritism. Importantly, it shows that winners do not support democratic violations because they believe these actions serve their party’s strategic interests. Rather, they are more likely to perceive such violations as consistent with democratic values, suggesting a deeper psychological reinterpretation rather than a calculated trade-off. The third paper extends the theory to a comparative context by analyzing post-election survey data from 31 democracies. The findings confirm that in-party favoritism mediates the relationship between electoral victory and support for democratic norm violations and that this effect endures for up to a year after an election. Collectively, these three studies advance an alternative, psychologically grounded explanation for why electoral winners, despite expressing greater satisfaction with democracy, are more likely to support actions that undermine it. The dissertation also contributes to the literature on affective polarization by highlighting the underappreciated role of in-party favoritism. While most existing research has focused on out-party dislike, these findings demonstrate that positive affect toward one’s own party can be equally corrosive. In doing so, the project refocuses scholarly attention on the ways partisan identity shapes political behavior, and the implications this has for democratic resilience
Neutron Capture and Scattering Measurements for the Deep Underground Neutrino Experiment
Get PDFThe Deep Underground Neutrino Experiment (DUNE) is the next generation long baseline neutrino experiment using a liquid argon time projection chamber (LArTPC). The main scientific motivation is to measure the neutrino oscillation parameters. The measurement of neutrino energy affects the precision of the neutrino oscillation probability. To improve the precision of neutrino energy, we are developing a pulsed neutron source for the DUNE energy calibration. A Deuterium-Deuterium generator (DD generator) test was performed on the ProtoDUNE detector to confirm that the neutron capture events can be seen in a LArTPC. The Argon Resonant Transport Interaction Experiment (ARTIE) was performed to measure the predicted decrease in the neutron cross section in argon at 57 keV, which has implications for the uniformity of the DD generator neutrons. More measurements of neutron cross section are needed to accurately model neutrons in liquid argon detectors. The first transmission measurement of the Multiple Argon Experiments (MArEX) project demonstrated that n TOF is an excellent facility with which to make transmission rate measurements and prepared us for additional studies of neutron interactions in the future
Conservation in Agriculture: Evaluation of Irrigation Efficiency Subsidy Programs and Estimating the Value of Robotic Weeding
Get PDFThis dissertation critically evaluates technology adoption in agriculture in the United States. Using robust econometric methods and a model of agricultural production, I study the effects of voluntary conservation incentive programs and adoption of newly developed robotic weeding technologies on farm production decisions. The overarching theme of these three essays is evaluating how adoption of conservation practices and precision agriculture address the challenges of reducing the environmental impact of agriculture and increasing agricultural productivity.
Agricultural conservation programs in the United States are largely centered on voluntary financial and technical assistance. The ultimate impact of any conservation program depends on how the new technology affects an individual farmer's production decisions. As a result, changes to the production function caused by technology adoption can erode the potential environmental benefits of adoption or adoption may not be additional, i.e., adoption may occur in the absence of a contract. The first two essays examine how government incentive programs influence farmer behavior related to land use and water use while the third essay evaluates the economics of robotic weeding adoption in specialty crops.
The first essay estimates the effect of the California State Water Efficiency and Enhancement Program (SWEEP) on crop choice and water use in agriculture. I use applicant-level data on SWEEP enrollment combined with remotely-sensed data on crop choice and consumptive water use to estimate the impact of program participation. I find important heterogeneities in program impacts related to the source of water used for irrigation. Funded applicants that have access to surface water switch to more water-intensive crops compared to unfunded applicants.
The second essay uses a novel combination of administrative data from the United States Department of Agriculture (USDA) and remotely sensed data on consumptive water use to evaluate the effect of irrigation investments through the Environmental Quality Incentives Program (EQIP) on production decisions. We use the EQIP application process to account for selection bias into the program and potential imperfect additionality of contracts. We find that enrollment in EQIP leads to an increase in the proportion of total acreage planted with specialty crops and allows farms to avoid reductions in planted acreage through fallowing or idling acreage. However, after constructing a set of control farms that are free to self-fund irrigation investments, we find that there is limited additionality of the program.
The third essay constructs a model of specialty crop production, focusing on the choice between newly developed robotic weeding technologies and conventional weeding. In response to rising labor costs and challenges with labor availability in the United States, new automated and precision agriculture technologies are being developed as alternatives. We calibrate the model using preliminary data collected on weeding efficacy from onion growers in the Pacific Northwest that are experimenting with robotic weeding technologies, parameters from the current literature, and personal communication with individual growers and robotic weeding experts. We find that an interior solution for partial adoption of robotic weeding relies on the relative relationship between the robotic weeding and non-robotic weeding cost functions. For any level of robotic weeding adoption, the two cost functions must cross within the distribution of weed density across a farm. In a sensitivity analysis of the robotic weeding cost function, we find that total farm profits are more sensitive to small changes in weeding efficacy compared to changes in the crop damage rate across the majority of the distribution of weed densities, and is particularly important at high weed densities.
Taken together, the papers in this dissertation provide valuable insight into farmers' adoption decisions, including ones influenced by cost-sharing conservation programs and newly available technologies. This research illustrates that financial incentives for adopting more efficient irrigation technologies change the farm production function such that farmers may increase specialty crop acreage and avoid reductions in planted acreage. This response affects the aggregate impact of conservation contracts. We also find that there is limited additionality of installing irrigation technologies through USDA EQIP. Variation in average weed density and differences in the variable costs of production depending on weeding technology adjust the level of robotic weeding adoption for specialty crop production. Robotic weeding and hand weeding are complementary, with the optimal level of robotic weeding adoption across a farm dependent on relative costs and weed density
A Quartet of Mitosis: Investigation of the Roles of AtKinesin-14As in Spindle Assembly
Get PDFKinesins are essential microtubule-based motor proteins that play critical roles in plant mitosis, especially in the assembly and function of the mitotic spindle. This work investigated the composition, diversification, and cooperative functions of kinesin motors in Arabidopsis, with a focus on the Kinesin-14 subfamily. Previous comparative genomic analyses highlighted the unique expansion of plant kinesins, particularly Kinesin-14s, which may compensate for the absence of cytoplasmic dynein and support plant-specific cytokinetic mechanisms. Functional studies of the Kinesin-14A motors ATK1, ATK5, KatB, and KatC revealed both redundancy and divergence, with distinct contributions to spindle pole organization, gametophyte viability, and stress response. Protein interaction assays suggested complex formation among Kinesin-14A paralogs, and chimeric analysis underscored the non-substitutable function of ATK1’s tail domain. Further genetic analysis uncovered a synergistic relationship between Kinesin-14A and Kinesin-5 motors, demonstrating that either ATK5 or RSW7 is indispensable for normal growth and gametogenesis. Together, these studies provided new insights into the evolution and coordination of mitotic kinesins in plants, advancing our understanding of spindle dynamics and motor protein interactions in a plant-specific context
From Hatchery to Harvest: Adaptive Management for Climate-Resilient Oyster Aquaculture
No full textShifts in temperature and other climate change related stressors will have direct consequences on the world’s future food production and security. Aquaculture is the fastest growing food production sector globally and hatcheries are expected to play a key role in this continued expansion. All of my dissertation chapters use the Pacific oyster, Crassostrea gigas, to better understand the effects of current hatchery and farm practices and to test the effectiveness of management strategies that could be implemented to enhance oyster resilience.My first chapter aimed to characterize how different stages of the aquaculture process alter standing genetic diversity. Using RAD-sequencing three distinct families were identified that were composed of both fast and slow growing oysters, with no strong evidence to suggest that the distribution of fast and slow individuals differs by family. Some evidence was found that slow growing oysters may be driving within cohort genetic difference before metamorphosis (time point 2) and after transition to raw seawater in the FLUPSY (time point 4) but, the genetic differences driving this are no longer present by the time these oysters are ready to be transitioned to the grow-out farm (time point 5). Therefore, while slow growers may retain some genetic diversity, because of the high mortality rates observed during the aquaculture process, the inconvenience of maintaining slow growing oysters throughout the aquaculture process may not be worth the tradeoff.My second chapter explore the benefits of culturing a diverse portfolio of genetic strains by experimentally testing whether a new strain of the Pacific oyster that has a more southern origin with warmer ocean temperatures, the Midori strain, is more resilient to an atmospheric heatwave compared to the Miyagi strain, the most commonly farmed oyster in the world. We found that the Miyagi strain has a significantly elevated metabolic rate after low tide compared to the Midoris that are able to maintain a relatively stable rate throughout the experiment. The Miyagis also show a disruption of their aerobic capacity during the heatwave and recovery. Overall, this study suggests that the Midori strain may be a valuable inclusion on farms for reduced vulnerability to extreme warm temperature events because it may be better at maintaining aerobic capacity over several days of thermal stress.My third chapter tests whether priming hatchery produced oysters with air allows them to more efficiently transition from a fully subtidal to intertidal environment. Control oysters showed significantly elevated metabolic rates after low tide post-priming, likely due to increased oxygen demand for recovery and homeostasis, while primed oysters maintained stable respiration rates. But, after their first low tide, primed oysters exhibited higher protein damage compared to the control oysters, suggesting a potential disruption of the oxidative stress response, while the control oysters successfully cleared damaged proteins with moderate increases in metabolic rate. Our results offer valuable insights into a practice that could be refined to enhance stress resilience and support the successful transition of oysters to grow-out farms under variable environmental conditions
Of microbes and melons: Contributions of the floral transmission pathway to early seed bacterial community assembly
Get PDFSeed-associated bacterial communities are a source of inoculum between plant generations. However, there is high variability in bacterial communities between seeds due to interacting ecological processes, making it difficult to discern their effects and predict community assembly outcomes. I posit that studying the transmission pathway between flowers and developing seeds will provide new insight into the bacterial community assembly of developing seeds. Using commercial watermelon (Citrullus lanatus) as a model, I tested the effects of multiple factors on this transmission pathway.In chapter 1, I conducted a literature review on the ecological processes potentially involved in microbial community assembly during seed development. Using metacommunity theory as a framework, I argued that the processes of selection, dispersal and drift act on seed microbial communities across spatial scales. I also advocated for future research that is spatially explicit and multi-scale, with emphasis on the effects of plant topography and chemistry on micro-scale processes, the role of animal vectors on macro-scale dispersal, and the interactions between processes.In chapter 2, I used field and lab studies to 1) compare the bacterial communities of stigmas and seeds of C. lanatus, 2), determine if bee pollination affects seed community composition, 3), test if stigma- and seed-associated bacteria can transmit from flowers to seeds, and 4) screen these bacteria for their impact on seed fitness. In a field survey, I found that 2-40% of seed-associated taxa were also detected on stigmas and that these bacteria made up 40.4% of the seed community. Using a field pollinator exclusion experiment, I found that honeybee visitation did not alter bacterial community composition in seeds. By inoculating stigma- and seed-isolated bacteria onto stigmas, I validated that strains could transmit to seeds. Finally, I found that inoculating such bacteria onto seeds had variable effects on watermelon seedling development. This work demonstrates that floral transmission makes important contributions to both the assembly and potential health impacts of bacterial communities in C. lanatus seeds.In chapter 3, I used inoculation experiments to test how the composition of bacterial synthetic communities (SynComs) inoculated on C. lanatus stigmas affected 1) bacterial transmission to seeds, 2) transmission of the pathogen Paracidovorax citrulli to seeds, and 3) fruit set rates. Through culturing, I found that individual bacterial strains had variable rates of floral transmission to seeds, and that floral transmission increased in SynComs with higher species richness. Through amplicon sequencing, I similarly found that the total relative abundance of florally transmitted SynCom strains increased in SynComs with higher richness. I also determined through sequencing and qPCR that P. citrulli transmission to seeds was reduced in SynCom inoculations compared to inoculation alone. Finally, I found that individual bacterial strains had variable effects on fruit set, and that SynCom inoculations had negligible effects on fruit set compared to inoculation alone. While this experiment had various design issues and technical limitations, it provides proof of concept for testing floral transmission with SynCom experiments, and I make recommendations for future SynCom experiments to better test how stigma community composition can be manipulated to prevent pathogen transmission and improve fruit development
Voice Quality and Laryngeal Complexity in Santiago Laxopa Zapotec
Get PDFThis dissertation provides a detailed description and analysis of the Santiago Laxopa Zapotec voice quality system, a minority language spoken by about 1000 people in the municipality of Santiago Laxopa, and how best to capture these patterns acoustically. The language includes four contrastive phonations: modal, breathy, rearticulated, and checked. The last two are types of creaky voice, which are differentiated in terms of their timing and phonetic realizations.This dissertation showcases a framework for analyzing voice quality and which acoustic measures need to be considered in order to capture the phonetic distinctions between the four phonation types. This framework consists of a two-step process of first conducting a multidimensional scaling analysis and determining which acoustic measures contribute the most to the dimensions. This analysis is followed by a random forest analysis to determine which acoustic measures are the most important for distinguishing between the phonation types. By combining these two analyses, we can determine which acoustic measures are the most important for distinguishing between the phonation types and how they are realized in the language by looking where the two analyses overlap.Additionally, this dissertation shows that Chai & Garellek's 2022 newly proposed acoustic measure, residual H1*, which measures the amplitude of the fundamental (H1), captures the differences in Santiago Laxopa Zapotec. Additionally, the results presented in this dissertation suggest that there are several areas that need to be considered when analyzing voice quality. The first two areas of spectral slope and aperiodic voicing/aspiration noise are well understood and established. The novel areas that need to be considered are the amplitude of the fundamental (i.e., residual H1*) and how these phonations are realized across the duration of the vowel. The results presented in this dissertation show that these four areas are crucial for capturing the phonetic distinctions between the four phonation types in Santiago Laxopa Zapotec
Novel Methods for Cell-free RNA Biomarker Characterization Using Nanopore Sequencing
No full textCancer is often detected as late-stage disease due to limitations in current detection methods. Existing diagnostic approaches can only identify morphological changes or lack the sensitivity required for early-stage detection. RNA liquid biopsies enable the comprehensive characterization of dynamic transcriptional changes resulting from the continuous release of cell-free RNA by tumor cells. I describe novel approaches for combining short and long-read sequencing for transcriptome assembly followed by quantification to analyze cell-free RNA in vitro and in vivo. I will present data applying this method to human lung cells transduced with mutant KRAS and treated with cigarette smoke extract to discover novel cell-free RNA biomarkers for lung cancer early detection. I will also discuss applying this method to assemble a cell-free transcriptome followed by short-read quantification for esophageal cancer early detection using patient plasma. Furthermore, I present novel approaches for discovering additional features of cell-free RNA with potential diagnostic utility. Finally, I present a novel computational approach for profiling non-human RNAs that may derive from the tumor microbiome. Collectively, my thesis work encompasses the development of novel experimental and computational methodologies to profile cell-free RNA biomarkers for cancer early detection
The “Gig Economy”: Neoliberalism and the Working Practices of Bay Area Jazz Musicians
Get PDFIn this dissertation I draw on 45 in depth interviews and five years of ethnographic fieldwork in the Bay Area jazz scene to argue that the contemporary working practices of Bay Area jazz musicians constitute a refusal and critique of neoliberal ideology. I situate my work in a recent strain of scholarship that has demonstrated the ways in which jazz and the figure of the gigging musician have been appropriated by the corporate consultants, management science, and the business world more broadly to romanticize flexible precarious labor and promote entrepreneurial selfhood. I draw on a Bourdieuian framework to describe the ways in which Bay Area jazz musicians share a habitus constituted by two ideal types, the artist and the professional. I locate these ideal types in the historical contexts of jazz history and African American musical labor. I then argue that musicians negotiate the competing interests of these ideal types in their working lives in ways that affirm the value of musical labor, suggest a sense of collective responsibility, speak to the political valences of black music, and refuse neoliberal notions of human capital. I then move to a critique of the ways in which jazz and “jamming” have been adopted as metaphors for business management in organization science literature, and argue that the contemporary structures, practices, and rituals of Bay Area jazz jam sessions represent a refusal of neoliberal forms of competition and meritocracy. I conclude with a discussion of the ways in which members of the Bay Area jazz scene, especially women, have challenged sexism in the scene in ways that move beyond neoliberal feminism’s narrow focus on tokenistic representation
The Effects of Sea Level Rise and Extreme Precipitation on Emerging Groundwater and Contaminant Migration
No full textClimate change is reshaping coastal hydrology, with sea level rise (SLR) and more frequent extreme weather events intensifying the risk of flooding and shallow groundwater emergence in urbanized lowland regions. In the San Francisco Bay Area, these changes threaten to mobilize subsurface contaminants, many of which remain in place from historic industrial activity, posing renewed risks to environmental health and safety. As aging infrastructure with associated trenches are increasingly exposed to rising groundwater and intensifying storm surges, accurately predicting surface flooding, emerging groundwater, subsurface water dynamics and contaminant transport becomes critical. This dissertation addresses this challenge through an integrated, three-part analysis of hydrologic response, geochemical indicators, and site vulnerability assessment tools tailored to coastal conditions.The San Francisco Bay Area faces mounting risks from sea level rise, a consequence of climate change that threatens to exacerbate both coastal flooding and the emergence of shallow groundwater. These hydrologic shifts can mobilize legacy contaminants buried in coastal sediments and artificial fill, heightening the potential for human exposure, particularly to volatile organic compounds that pose vapor intrusion and groundwater contamination risks. This dissertation presents an integrated, three-part investigation into the physical and geochemical processes driving groundwater emergence and contaminant mobilization under sea level rise and extreme climate events, with a focus on practical tools for risk assessment and site prioritization.In Chapter Two, field monitoring across 16 wells in three representative low-lying communities, Manzanita, Tamalpais Valley, and Atchison Village over Water Year 2023 was used to quantify the response of groundwater levels to highest astronomical tides and atmospheric river events. Results show that sewer trenches and preferential flow paths amplify groundwater rise, particularly in artificial fill and near the coast, underscoring the critical role of subsurface infrastructure in flood dynamics.Chapter Three explores the geochemical signatures of groundwater, surface water, and emerging water sources using stable isotopes (δ¹⁸O, δ²H), major ions, and geochemical ratios. These data were used to distinguish between rainwater, tap water, saltwater, and true groundwater discharge. Mixing models and ternary diagrams showed distinct chemical profiles for water samples influenced by subsurface mobilization processes versus those from surface flooding from marine overtopping or rainwater ponding, enabling a more accurate identification of emerging groundwater.Building on these physical and chemical insights, Chapter Four introduces a rapid, cost-effective, multi-tiered indexing framework to prioritize contaminated sites vulnerable to climate-driven hydrologic change. The core of the framework is a modified DRASTIC index, which assesses hydrogeologic vulnerability. To capture additional risk factors, three supplemental indices were developed: the Site Characteristics Index, Contaminant Characteristics Index, and Inundation Vulnerability Index. These Supplementary Indices integrate site specific data on geologic permeability, contaminant mobility, and flood susceptibility. Fourteen sites with volatile organic compound contamination— specifically chlorinated solvents such as trichloroethylene and tetrachloroethylene, and shallow groundwater were evaluated as sea level rise and groundwater rise vulnerability, with index scores standardized using z-score transformation. Bivariate correlations and composite rankings, based on both predefined and data-driven weights, identified sites at highest risk. A strong correlation between the two weighting approaches confirms the strength of the method.Collectively, the findings of the research demonstrate that groundwater emergence and contaminant transport are intensifying hazards in coastal settings affected by sea level rise. The integrated framework developed in this study provides a scalable, evidence-based tool for prioritizing investigation and mitigation at contaminated sites, supporting proactive climate adaptation and public health protection strategies in vulnerable urban areas.Together, these chapters provide a unified framework for diagnosing, interpreting, and prioritizing groundwater-related risks in coastal contaminated sites. By combining field-based hydrologic monitoring, geochemical source tracing, and index-based site ranking, this study offers a replicable approach for identifying areas most susceptible to contaminant mobilization under future sea level and climate scenarios. The findings underscore the importance of incorporating subsurface processes into regional adaptation planning and provide a science-based foundation for directing limited resources toward the most at-risk locations. As sea level rise accelerates, these methods offer timely insights to guide sustainable land use, infrastructure resilience, and flood mitigation in vulnerable coastal communities