http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/ucd_etd/rss Recent eScholarship items from UC Davis Electronic Theses and Dissertations Wed, 14 Oct 2026 06:51:25 +0000 https://escholarship.org/uc/item/29q725k5 Following the specified legalization of cannabis products in California, the cannabis industry has quickly grown as new products enter the market and offer various ways for consumers to experience the psychoactive effects of cannabinoids. Edible cannabis products, in particular, have become increasingly popular as they are easily accessible, discreet, and produce a longer-lasting psychoactive effect than smoking cannabis. The Sacramento County District Attorney’s Office Laboratory of Forensic Services does not currently have a validated method for analyzing cannabis edible evidence. The laboratory hopes to add a method for extracting Δ9-THC from edibles to its Controlled Substances Unit’s (CSU) technical manual. For this study, pre-existing Δ9-THC extraction methods from external sources were compiled and evaluated for their effectiveness, extraction cleanliness, and compatibility with the materials available in the CSU. Five procedures were gathered, including a QuEChERS-based... https://escholarship.org/uc/item/29q725k5 Mon, 12 Oct 2026 00:00:00 +0000 Lee, Olivia https://escholarship.org/uc/item/9zt9c241 This dissertation explores the literary, historical, and philosophical connections between Michel de Montaigne's Essays and Friedrich Nietzsche's works of the middle period. In two sections that focus on Nietzsche and Montaigne respectively, I explore the complementary elements of their thinking on education, the nature of individual experience and interpersonal dynamics, and the literary innovations they use to express and communicate these ideas. Each writer proposes an individualist approach to self-understanding and knowledge that nevertheless leaves space for productive educational and intellectual relationships in addition to the creation of a deeper and more authentic form of self. This study offers new ways of thinking about the relationship between Montaigne and Nietzsche's works and Montaigne's influence on Nietzsche's "joyous" way of thinking and living, as well as implications for pedagogy and educational dynamics in the contemporary classroom. https://escholarship.org/uc/item/9zt9c241 Fri, 9 Oct 2026 00:00:00 +0000 Konick-Seese, Jeremy Leon https://escholarship.org/uc/item/9zg8469z Rice production relies heavily on tillage for seedbed preparation, crop establishment, and residue management. However, reducing tillage may decrease production costs, conserve soil moisture, and provide greater flexibility in the timing of field operations. Despite these potential benefits, the effects of reduced tillage on rice productivity remain uncertain, particularly in flooded rice systems. This dissertation evaluated the agronomic effects of reduced tillage in rice at both global and regional scales and examined alternative tillage and establishment systems for California rice production.The first study used a global meta-analysis of 115 studies and 579 paired observations to quantify rice yield responses to no-till (NT) relative to conventional tillage (CT) and identify conditions associated with improved NT performance. Across studies, NT reduced rice yield by 4.8%. Soil organic carbon, N fertilizer rate, soil pH, and clay content were among the most important factors... https://escholarship.org/uc/item/9zg8469z Fri, 9 Oct 2026 00:00:00 +0000 Godbey, Mia https://escholarship.org/uc/item/9sb8d8rx Genetic variation provides the material for evolution, but the variation available to evolutionary processes is itself shaped by biological mechanisms. Mutations determine how genetic differences enter populations, while regulatory systems determine how those differences are expressed. In this dissertation, I use Arabidopsis thaliana to examine these two stages: the generation of genetic variation through mutation and the translation of genetic differences into gene expression plasticity.I investigate the genetic architecture of transcriptomic plasticity in response to salicylic acid using a recombinant inbred population. Although the parental accessions exhibited similar transcriptional responses, their recombinant progeny showed extensive transgressive segregation, with most expression quantitative trait loci acting in trans. These results reveal substantial regulatory variation hidden beneath similar parental phenotypes and suggest that trans-regulatory contributions to plasticity... https://escholarship.org/uc/item/9sb8d8rx Fri, 9 Oct 2026 00:00:00 +0000 Lensink, Mariele Elizabeth https://escholarship.org/uc/item/9s6631xd Wildfire is an important ecological disturbance in California that occurs in forested, urban and suburban areas. These fires generate biochar and other partially burned plant materials capable of entering urban and suburban aquatic environments. However, little is known about how biochar may interact with mosquitoes that utilize these aquatic habitats for reproduction. This thesis investigated the effects of wood derived biochar on Aedes aegypti across multiple stages of the mosquito life cycle, from oviposition site selection to larval development and adult physiology, while also examining changes in the microbial communities of larval rearing water. The first chapter reviews the current understanding of Aedes aegypti oviposition behavior and the sensory and environmental cues that influence female selection of oviposition sites. This review provides a framework for understanding how changes in aquatic habitat characteristics may alter oviposition behavior and highlights... https://escholarship.org/uc/item/9s6631xd Fri, 9 Oct 2026 00:00:00 +0000 Rodrigues, Nicole S https://escholarship.org/uc/item/9s6154jg This dissertation examines psychedelic-assisted therapy (PAT) as an emerging and unsettled field of care in which suffering, meaning, and altered states of consciousness are being organized across clinical, ceremonial, decriminalized, and underground settings. Drawing on sixty in-depth qualitative interviews with facilitators and patients, it argues that psychedelic healing cannot be understood through pharmacology or acute experience alone, but must be situated within the social, relational, and structural conditions that shape whether transformation becomes durable, distorted, or impossible to sustain. Across three empirical chapters, the project develops the concepts of liminal authority and psychedelic careers to explain how facilitators construct legitimacy and how patients learn to interpret and carry forward meanings from altered-state experiences through dispositional and interpretive resources that are themselves unequally distributed, and extends cultural brokerage literature... https://escholarship.org/uc/item/9s6154jg Fri, 9 Oct 2026 00:00:00 +0000 Mason, Joshua James https://escholarship.org/uc/item/9rn2d337 The mitochondrion is an organelle that defines the cell's bioenergetic capacity through the generation of ATP. It does this through the maintenance of a proton gradient which is used to power ATP synthase (Complex V). This gradient is generated by the electron transport chain, a series of proton-pumping membrane protein complexes. The electron transport chain forms higher-order structures known as supercomplexes. Supercomplexes are a ubiquitous feature of eukaryotes and an excellent entry point to study eukaryogenesis through the lens of endosymbiotic advantages that supercomplexes may confer. Eukaryotic supercomplexes are large, approximately 1.7 MDa in size, and have many accessory subunits have become structurally significant. Mutational studies are therefore difficult for eukaryotic systems, making bacterial systems a more attractive model system for mutational studies of respiratory supercomplexes. The alphaproteobacterium Paracoccus denitrificans is the only bacterium shown... https://escholarship.org/uc/item/9rn2d337 Fri, 9 Oct 2026 00:00:00 +0000 Hale, Andrew Diller https://escholarship.org/uc/item/9rd0p9bh Electrical activation of the heart is coordinated by the propagation of excitation waves through cardiac tissue. Mathematical models of these processes range from minimal phenomenological models to high-dimensional biophysically detailed ionic models. An important question is which features of traveling wave dynamics are shared across this hierarchy of models and which depend on physiological detail. This dissertation investigates the existence, stability, and bifurcation structure of periodic traveling waves in mathematical models of cardiac tissue to address this question. We compute families of periodic traveling wave solutions and their dispersion relations for the minimal FitzHugh-Nagumo model and the biophysically detailed Beeler-Reuter and ten Tusscher-Panfilov (TP06) models. While all models exhibit the canonical fast and slow wave structure, increasing physiological detail introduces substantial complexity. The TP06 model supports multiple distinct branches of unstable... https://escholarship.org/uc/item/9rd0p9bh Fri, 9 Oct 2026 00:00:00 +0000 Lovero, Vincent Louie https://escholarship.org/uc/item/9mn96763 Antimicrobial resistance (AMR) is a complex One Health challenge shaped by interactions among food-producing animals, microbial communities, production environments, food products, and humans. Understanding AMR in livestock systems therefore requires consideration not only of antimicrobial use, but also of the ecological processes that maintain resistance, the pathways through which resistant bacteria and antimicrobial resistance genes (ARGs) reach human interfaces, and the surveillance approaches used to detect them. This dissertation examines AMR across livestock production, food, environmental, and occupational interfaces using evidence synthesis, metagenomics, phenotypic antimicrobial susceptibility testing, and whole-genome sequencing.Chapter 1 mapped the evidence on occupational exposure to antimicrobial-resistant bacteria in U.S. livestock production and associated processing systems. Thirty publications representing 23 study families were identified, with evidence heavily... https://escholarship.org/uc/item/9mn96763 Fri, 9 Oct 2026 00:00:00 +0000 Talukder, Sudipta https://escholarship.org/uc/item/9jn9944q This study examines participation, performance, and success in Advanced Placement (AP) and Dual Enrollment (DE) at Northern California High School (NC High School, an anonymous school) through an Opportunity to Learn (OTL) and Human Capital Theory (HCT) lens. The study asks: (1) What are the patterns of participation and success in AP (Advanced Placement) and Dual Enrollment (DE) courses, and how do these differ across student subgroups (race/ethnicity, gender, and socioeconomic status [SES])? And (2) What is the relationship between students’ prior academic achievement (GPA and standardized test scores) and their performance in AP and DE courses? How do these relationships differ by student characteristics (race/ethnicity, gender, and SES)? This quantitative study relies on administrative records and the analysis combines descriptive statistics and correlational analyses testing relationships and whether they differ across groups. Additionally, identifying gaps in enrollment... https://escholarship.org/uc/item/9jn9944q Fri, 9 Oct 2026 00:00:00 +0000 NOOR, SAMIR AHMAD https://escholarship.org/uc/item/9gf867df The development of visual attention during the first year of life represents a critical shift from reflexive, stimulus-driven orienting to flexible, goal-directed control. While decades of research document this transition, the precise mechanisms driving these shifts in looking behavior remain poorly understood. Grounded in dynamic systems and embodied cognition frameworks, this dissertation proposes that infants actively construct a curriculum for statistical learning through their own motor behavior. Each newly acquired motor milestone fundamentally alters the statistical distribution of visual input, continuously recalibrating the infant’s attentional priority map.Across three eye-tracking studies, this work examines how the onset of specific motor milestones—crawling and independent sitting—reshapes both the overt deployment of attention and the covert spatial mechanisms underlying it. The first study investigates the transition to self-locomotion, evaluating how crawling... https://escholarship.org/uc/item/9gf867df Fri, 9 Oct 2026 00:00:00 +0000 Nelson, Christian Marie https://escholarship.org/uc/item/9f9081nh This dissertation presents a search for pair-produced vector-like quarks in the fully hadronic final state using proton-proton collision data collected by the CMS detector during the 2016–2018 data-taking period of LHC Run 2. The dataset corresponds to an integrated luminosity of 138 fb−1 at a center-of-mass collision energy of 13 TeV. The search is interpreted in terms of up-type T quarks and down-type B quarks that decay to third-generation quarks and electroweak or Higgs bosons, with decay modes T → bW, T → tZ, T → tH, B → tW, B → bZ, and B → bH.The analysis targets the high-momentum regime in which hadronically decaying W, Z, and Higgs bosons and top quarks can merge within large-radius jets, while energetic bottom quarks are reconstructed as bottom-like AK8 jets. These jets are classified with the Boosted Event Shape Tagger (BEST), a neural-network tagger that uses boosted-frame event-shapes and jet-substructure information to identify jets as W, Z, Higgs, top, bottom, or... https://escholarship.org/uc/item/9f9081nh Fri, 9 Oct 2026 00:00:00 +0000 Abbott, Samantha https://escholarship.org/uc/item/94v4w2bx The Compact Muon Solenoid (CMS) is a general purpose particle detector that is used to record collision products from protons accelerated by CERN's Large Hadron Collider (LHC). The High-Luminosity LHC (HL-LHC) is the planned upgrade to the LHC that will bring a harsher radiation environment and higher event rates that CMS must be able to withstand. The gaseous electron multiplier (GEM) subsystem upgrade, GE2/1, is currently in the final stage of quality control (QC8), which validates GEM chamber performance using cosmic ray muon tracks. A description of GE2/1 QC8 is provided, which resulted in chamber efficiencies above 95%. Additionally, a search for pair-produced vector-like quarks (VLQs) in all-hadronic final states is presented, using Run 2 CMS data at 13 TeV, where the signal region is composed of four highly boosted jets. The Boosted Event Shape Tagger (BEST) is used to identify the parent particle of each of the four jets in simulated signal and background events, as well... https://escholarship.org/uc/item/94v4w2bx Fri, 9 Oct 2026 00:00:00 +0000 Barton, Sydney https://escholarship.org/uc/item/94p5m041 This dissertation presents three studies exploring the important role of caregivers in shaping infants’ experiences. Specifically, these studies examine how caregivers shape infants’ attention and learning through coordinated, multimodal interactions—including gaze, gesture, and language—focusing on the temporal and contextual dynamics of these processes. The first chapter of the dissertation provides a general overview of each chapter. Chapter II investigates whether North American caregivers and their 9-month-old infants coordinate their attention by applying the Actor Partner Interdependence Model within a Dynamic Structural Equation Modeling framework. This work adds to a growing literature on the coordination of attention by characterizing joint attention and mutual gaze as emergent outcomes of dynamically coupled interactions. Chapter III focuses on caregivers’ communicative cues by examining whether parents’ pointing and tapping gestures facilitate 6- and 9-month-old infants’... https://escholarship.org/uc/item/94p5m041 Fri, 9 Oct 2026 00:00:00 +0000 Kızıldere, Erim https://escholarship.org/uc/item/91r719ss Modern digital chip design requires repeated optimization decisions across synthesis, timing analysis, and physical implementation. Although reinforcement learning and other machine-learning methods provide promising approaches for exploring large design spaces, applying them to electronic design automation (EDA) requires more than an optimization policy. A practical learning-based system must also provide a stable agent--environment interface, valid design transformations, reproducible task definitions, real backend evaluation, and structured experimental outputs.This thesis presents RL-CHIP-Bench, a benchmark-integrated framework for sequential chip-design optimization with real EDA feedback. The framework separates benchmark control, agent interaction, semantic action representation, backend execution, quality-of-result (QoR) evaluation, reward computation, and artifact logging into modular components. A reinforcement-learning-compatible environment exposes a standardized sequential... https://escholarship.org/uc/item/91r719ss Fri, 9 Oct 2026 00:00:00 +0000 Liu, Yichen https://escholarship.org/uc/item/8zf7274m Metal music was introduced and localized in Taiwan under the intersecting conditions of Cold War militarism and Kuomintang authoritarianism in East Asia of the 1980s. Since the 1990s, Taiwanese metal has increasingly been understood as a post-authoritarian and anticolonial expressive form associated with resistance to Kuomintang Chinese nationalism and with Taiwanese cultural and political self-definition. Through the performance and embodiment of heavy metal musical sounds, musicians and audiences construct and negotiate a postcolonial sense of Taiwaneseness. This dissertation complicates celebratory accounts of Taiwanese metal as a straightforward medium of postcolonial resistance by examining how musical activism can simultaneously challenge one form of domination while reproducing others. In particular, I investigate how constructions of Taiwaneseness in metal remain entangled with global Whiteness, Orientalism, Han-centered nationalism, anti-Austronesian racism, and the racialization... https://escholarship.org/uc/item/8zf7274m Fri, 9 Oct 2026 00:00:00 +0000 Feng, Mark Hsiang-Yu https://escholarship.org/uc/item/8tn590n8 The California chaparral is a native environment characterized by poor nutrient availability, low precipitation and its propensity to fire. The native plants of this biome have evolved and specialized to these inhospitable conditions, particularly to the normal fire regime. The increase in fire frequency and intensity over the past decades have put a strain on this ecosystem. To mitigate this damage, ecological restoration efforts have been developed. Salvia mellifera is a cornerstone species in this ecosystem, and its restoration efforts are impacted by high out-planting failure rates. To address this situation, this research focused on the identification of Trichoderma species native to this environment and their evaluation as plant growth promoters. This study is the first to focus on the diversity of these beneficial microfungi in the California Chaparral. A total of 30 different species of Trichoderma were found, and 296 isolates were tested as a plant growth promoter for... https://escholarship.org/uc/item/8tn590n8 Fri, 9 Oct 2026 00:00:00 +0000 Sáez Cortez, Felipe Esteban https://escholarship.org/uc/item/8sq1g7jx This dissertation uses online and field experiments to study workers' perceptions of and preferences for meaningful work, the mechanisms that impact work meaning, and the mental health benefits of purposeful employment. The first chapter develops a novel online experiment with 387 workers on Prolific to examine how workers perceive and respond to meaningful work. Workers exhibit substantial heterogeneity in both what they find meaningful and the work incentives they seek: roughly 31 percent pursue only monetary incentives, while 57 percent of workers sacrifice up to 14 percent of possible pay (averaging roughly 3 percent) for more meaningful work. I find that meaning-valuing workers increase their productivity on an image-description task when assigned to more meaningful work, while a light-touch awareness intervention raises perceptions of meaning for these workers without shifting underlying incentive preferences. The second chapter investigates two mechanisms through... https://escholarship.org/uc/item/8sq1g7jx Fri, 9 Oct 2026 00:00:00 +0000 Beauregard, Remy Gould https://escholarship.org/uc/item/8gr4r5z2 Thermally tunable materials can provide the foundation for reconfigurable electromagnetic devices whose response can be modified without physically changing device geometry. This thesis investigates thermally tunable perovskite-oxide devices based primarily on strontium titanate (STO), a high-permittivity material with investigated temperature-dependent dielectric and optical properties. Electrical biasing of thin-film indium tin oxide (ITO) was used to generate localized Joule heating on STO. This enables controlled changes in material response across the investigated infrared, terahertz, and RF frequency regimes. The thermal platform was first developed and characterized using electrical measurements, thermal imaging, and COMSOL simulations to relate applied bias to sample heating. Terahertz time-domain spectroscopy (THz-TDS) showed a large tunable response in pulse delay and refractive index, demonstrating strong thermal tunability of STO. Fourier Transform Infrared (FTIR)... https://escholarship.org/uc/item/8gr4r5z2 Fri, 9 Oct 2026 00:00:00 +0000 Samarah, Ziyad https://escholarship.org/uc/item/8dt3b27x Not all genes are essential for plant survival, and understanding which genes can tolerate loss-of-function (LoF) mutations and why offers a powerful lens through which we can study plant adaptation, gene function, and crop improvement. This dissertation develops and applies a framework for genome-wide LoF burden testing across two plant systems, moving from foundational discovery in a model organism to practical application in a globally important crop.The first chapter establishes this framework in Arabidopsis thaliana, where 91,751 naturally occurring LoF variants were identified from public whole-genome sequencing data spanning over 1,000 accessions. LoF-intolerant genes were found to be enriched for active chromatin marks and essential biological functions, while LoF-tolerant genes were disproportionately associated with defense responses, pollen recognition, and other dispensable or environmentally contingent processes. By collapsing independent LoF alleles into gene-level... https://escholarship.org/uc/item/8dt3b27x Fri, 9 Oct 2026 00:00:00 +0000 Zhao, Kehan https://escholarship.org/uc/item/8b77b3nv Blockbuster action movies and video games require eye-capturing destruction effects, and one costly component of a destruction engine is the fracture simulation. In computer graphics, the state of the art for incorporating runtime fracture effects into a scene involves prescoring an object and treating each fractured piece as a rigid body. If sufficient force is applied, the material breaks apart, but the cracks in the object are predetermined. Rather than using prescored bodies, the simulation of fracturing rigid bodies has been improved by implanting a fracture mechanics solver inside of a rigid body simulator which resolves contacts and collisions between rigid bodies. To efficiently propagate cracks in the object, we will employ an emerging element method, the virtual element method (VEM).VEM is an element-based method in which the basis functions are not computed explicitly, and information about a given basis function is only known through its degrees of freedom. Since the... https://escholarship.org/uc/item/8b77b3nv Fri, 9 Oct 2026 00:00:00 +0000 Godkin, Benjamin Makoto https://escholarship.org/uc/item/89f08033 High-performance graph algorithms reside in a rich and combinatorial design space. Given a specific graph problem, there may be numerous algorithmic alternatives and a variety of choices for realizing a chosen algorithm as a software implementation or hardware module. Although these strategies may target the same underlying computation, they are generally treated as algorithmically distinct designs. The choices that separate one implementation from another are tangled together, and we explore them by trial and error. We therefore miss the structure that relates them. The diversity in graph algorithms and implementations creates several challenges: it is difficult to reason about computation patterns common across algorithms; exploring new algorithms and implementation choices requires luck, ingenuity, or both; and exploring optimizations for one implementation often requires significant engineering effort. This dissertation argues that graph algorithms need both a precise... https://escholarship.org/uc/item/89f08033 Fri, 9 Oct 2026 00:00:00 +0000 Odemuyiwa, Toluwanimi Oreoluwa https://escholarship.org/uc/item/86h3q0zb As lava cools, it provides new habitats and resources for life. Microbial colonization of newly exposed basalt contributes to weathering and ecosystem development, but we do not know which environmental and spatial factors structure these communities through time. To understand controls of microbial community assembly, we sampled 11 caves formed by basaltic lava flows spanning approximately 34 kyr across northern California and southern Idaho. In each cave, we sampled microbial biofilms and used 16S rRNA gene and internal transcribed spacer (ITS) region sequencing to identify bacterial and fungal communities, respectively. Here we show that microbial community composition in basaltic lava caves is structured hierarchically across spatial scales, with individual cave explaining more variation than lava flow age or biofilm color, while caves within the same lava flow are more similar to one another than caves from different flows. The strong influence of individual cave, together... https://escholarship.org/uc/item/86h3q0zb Fri, 9 Oct 2026 00:00:00 +0000 Williams, Caden Caroline https://escholarship.org/uc/item/8693r8t5 Whitebark pine (Pinus albicaulis) is a high-elevation conifer distributed across western North America that provides important ecological functions, including food and habitat for wildlife. The species has declined due to interacting threats from climate change, altered wildfire regimes, mountain pine beetle, and white pine blister rust (WPBR), leading to its listing as threatened under the U.S. Endangered Species Act. WPBR, caused by the introduced pathogen Cronartium ribicola, is a major threat to all North American five-needle white pines. For decades, federal and provincial nursery programs have screened inoculated open-pollinated families from candidate maternal trees in common garden trials to characterize genetic resistance. These programs have revealed both qualitative and quantitative resistance in many five-needle white pine species, with substantial evidence of quantitative resistance in whitebark pine. Here, we used the recently published chromosome-scale whitebark... https://escholarship.org/uc/item/8693r8t5 Fri, 9 Oct 2026 00:00:00 +0000 Allen, Brian https://escholarship.org/uc/item/8306x0c5 The building sector in the United States accounts for approximately 40% of total primary energy consumption and 35% of energy-related carbon dioxide emissions, with a substantial share of these emissions stemming from on-site fossil fuel combustion for space and domestic water heating. Numerous studies have shown that replacing conventional fossil-fuel based heating systems with high-efficiency electric alternatives reduces both building energy consumption and greenhouse gas emissions. Among water heating systems, storage-type systems have drawn particular attention for their inherent thermal energy storage (TES) capability, which allows hot water to be stored in the tank for later use. This capability decouples heat generation from hot water consumption, enabling water heating to be scheduled to meet operational objectives such as minimizing electricity, cost, reducing energy consumption, or shifting electrical demand to periods of high renewable generation or low carbon intensity.... https://escholarship.org/uc/item/8306x0c5 Fri, 9 Oct 2026 00:00:00 +0000 Ndigaya, Nathalie https://escholarship.org/uc/item/81p670n2 In this dissertation, we aimed to understand how to understand the specific mechanisms by which tremor effects motor adaptation. The driving hypothesis of the project was that externally-generated pathological tremor impairs the ability to distinguish errors that require corrections while internally-generated tremor (e.g. Parkinson’s Disease (PD) and Essential Tremor (ET)) does not impair learning in adaptation (the ability to detect errors) but rather impairs movement execution. Previous studies focused on patients with pathological tremor suggest an overall impairment of motor adaptation despite the retention of the learned movement recalibration. Thus, we investigated the extent learning is impacted by different manifestations of tremor in two distinct motor adaptation tasks. (1) Our first step to accomplish this was to examine the extent externally-generated tremor affects motor adaptation to physical movement perturbations in neurologically healthy individuals. We found that... https://escholarship.org/uc/item/81p670n2 Fri, 9 Oct 2026 00:00:00 +0000 Foray, Katherine https://escholarship.org/uc/item/7zp733d4 Plasma-activated water (PAW) has emerged as a potential sustainable alternative nitrogen fertilizer. However, physicochemical stability of reactive species following production presents a major challenge for its scalability and application in crop production. To our knowledge, this is the first study to simultaneously evaluate PAW storage strategies for improving physicochemical stability and investigate the effects of stabilized PAW on plant growth and composition under controlled-environment conditions. In this study, we characterized physicochemical stability of PAWs, and evaluated using spinach as a model crop. Spinach development was monitored using morphometric (derived from RGB imaging) and vegetation indices (derived from hyperspectral imaging). Our results demonstrated that adjusting PAW to pH 5.0 or higher stabilized NO₂⁻ and NO₃⁻ concentrations for up to 35 days, regardless of storage headspace. Stabilized PAWs (PAW5 and PAW12) resulted in approximately twice the spinach... https://escholarship.org/uc/item/7zp733d4 Fri, 9 Oct 2026 00:00:00 +0000 Zou, Yugeng https://escholarship.org/uc/item/7zn054qf The flat-tailed horned lizard (Phrynosoma mcallii) is a Colorado Desert endemic species with a long history of conservation and active management. Ongoing monitoring has relied on traditional mark-recapture data to inform management action. I used reduced representation genotype-by-sequencing techniques to generate a large single nucleotide polymorphism data set to assess fine-scale P. mcallii population structure, dispersal, landscape barriers to gene flow, and genetic diversity in California’s Imperial Valley with the overall goal to inform ongoing management and monitoring of the species.In my first chapter, over 500 individual P. mcallii DNA samples were genotyped to assess fine-scale population structure across the Imperial Valley. Using sparse non-negative matrix factorization paired with geographic capture data and discriminant analysis of principal components, I detected population structure across the east-west axis of the Imperial Valley, which had been described using... https://escholarship.org/uc/item/7zn054qf Fri, 9 Oct 2026 00:00:00 +0000 Fischer, Craig G. https://escholarship.org/uc/item/7v1478dn As global energy systems undergo a rapid transition toward electrification, traditional sustainability assessments often fail to account for the complex interplay between regional grid variability, economic feasibility, and the lived human experience. This dissertation establishes multidimensional industrial ecology approaches to evaluate the flows of energy and materials, the tradeoffs between performance metrics, and the transitions required for sustainability in the built environment and energy systems. The core contribution of this work lies in developing socio-enviro-economic models across multiple distinct sectors. First, a spatial techno-economic of industrial heat pumps (IHPs) across 25 U.S. electricity market regions demonstrates that while IHPs can reduce global warming potential (GWP) by up to 95%, their economic viability, measured via the levelized cost of avoided carbon (LCAC), is highly sensitive to regional electricity-to-gas cost ratios and grid carbon intensities.... https://escholarship.org/uc/item/7v1478dn Fri, 9 Oct 2026 00:00:00 +0000 Kanwal, Maria https://escholarship.org/uc/item/7q23r0wp The fire regimes, or the frequency, severity, spatial pattern, and seasonality of wildland fires of forested ecosystems in western North America are changing rapidly. In the mixed conifer forests of the Sierra Nevada, shifting fire regimes can be attributed to a combination of the following: the removal of indigenous land stewardship, over a century of fire suppression, and hotter, drier, conditions due to anthropogenic climate change. The removal of fire from the system led to large patches of dense, homogenous forest with high fuel loads unlike the historical forest mosaic containing a variety of gaps and openings, and these large dense patches are more likely to burn at high severity. Since many forests types in the Sierra Nevada are adapted to low severity, high frequency fire, the departure from historic fire regimes have led to shifts in forest structure and composition, which raise important questions about the future of forest ecosystems under a changing climate. In areas... https://escholarship.org/uc/item/7q23r0wp Fri, 9 Oct 2026 00:00:00 +0000 Saberi, Saba Juliet https://escholarship.org/uc/item/7nc629c2 Land surface deformation caused by natural and anthropogenic processes poses significant risks to infrastructure, groundwater resources, geothermal operations, and nearby communities. Interferometric Synthetic Aperture Radar (InSAR) provides a powerful remote sensing technique for measuring deformation over large spatial areas with high resolution, making it especially useful for monitoring hazards such as groundwater-induced subsidence, geothermal reservoir deformation, volcanic unrest, and earthquake-related surface changes. At the same time, the increasing volume of available satellite observations presents a growing challenge for manual analysis and interpretation. This dissertation investigates the use of machine learning methods for InSAR-based geophysical monitoring, with a focus on deformation forecasting, multi-modal data fusion, and automated image interpretation. In this dissertation, three related studies are presented. First, land subsidence in California’s... https://escholarship.org/uc/item/7nc629c2 Fri, 9 Oct 2026 00:00:00 +0000 Yazbeck, Joe https://escholarship.org/uc/item/7m52t50g Heteronuclear decoupling of carbon-hydrogen systems achieves two strong effects that aid in spectral exploration of chemical systems: 1) collapse of proton multiplets, simplifying the spectrum and 2) enhancement of an anemic natural abundance carbon signal. Established standards in heteronuclear decoupling involves high-power, broad band irradiation of the sample at ω_1 to fully decouple satellite and primary hydrogens – producing a carbon-only spectrum boosted by redistribution of the n+1 multiplets as well as population transfer enhancement via dipolar cross-relaxation. However – exploration of the broad-band irradiation signal has identified a physical effect when ω_1=J γ_H/(2γ_S ) – creating an interference between the inhomogeneous static magnet field and the scalar J coupling, reducing line broadening nearly thirty-fold with an upper theoretical limit of nearly 2000-fold. This extreme line narrowing effect has been dubbed “matched decoupling” – a moniker predicated on using... https://escholarship.org/uc/item/7m52t50g Fri, 9 Oct 2026 00:00:00 +0000 Aztiazarain, Javier https://escholarship.org/uc/item/7k23m1p3 The target of achieving net-zero greenhouse gas emissions by 2050 serves as the primary normative benchmark in federal climate goals and international decarbonization pledges, establishing a reference point for evaluating long-term energy transitions. While the scientific and economic optimality of a rigid mid-century net-zero mandate remains actively debated compared to dynamic carbon-pricing or welfare-maximizing cost-benefit frameworks, evaluating this target provides critical insight into the physical feasibility, sectoral demands, and economic trade-offs of deep decarbonization. Understanding the nuances of the decarbonization journey so far offers valuable insights into the successes and failures of market and policy mechanisms in shaping this trajectory. Aggregate national analyses mask profound sectoral and spatial heterogeneity across the U.S. economy, obscuring the specific mechanisms driving historical decarbonization. To offer granular insights about these diverse... https://escholarship.org/uc/item/7k23m1p3 Fri, 9 Oct 2026 00:00:00 +0000 Qamar, Muhammad Ali https://escholarship.org/uc/item/7jd552th In 2022 the OECD reported that member countries spent an average of 21% of GDP on public social spending. Indeed, welfare states make up a massive portion of national budgets and serve as an important safety net in times of economic crisis. Unsurprisingly, welfare spending is a bitterly fought-over political arena. As the political reverberations of the Global Financial Crisis continue to ripple and artificial intelligence heralds another potentially destabilizing economic shock, understanding the politics of the welfare state in the 21st century is paramount. This dissertation offers contributions to political science in two main areas: first, to the literature that argues existing welfare state contexts are a key variable in understanding political behavior in response to economic shocks; and second, to research on attitudes toward welfare state expansion in the face of automation threats. Chapter 1 offers causal evidence to answer how attitudes toward the welfare state and... https://escholarship.org/uc/item/7jd552th Fri, 9 Oct 2026 00:00:00 +0000 Haddad, Julian Anthony https://escholarship.org/uc/item/7g60q2fv Drawing on 83 interviews supplemented by ethnographic observations between 2020 and 2022, this dissertation contributes to discussions of refugee insecurity and precarity by exploring how Afghan refugees experience a shift from physical insecurity in Afghanistan to legal, economic, and social insecurity in the United States and Türkiye. Grounded in the human security framework, it examines the political, economic, and cultural structures that undermine refugees’ human security. Although refugees flee war and persecution in search of safety, they often encounter new forms of insecurity in host societies, including legal insecurity, labor precarity, and social exclusion driven by xenophobia and intolerance. Gender is one way to see how economic, political, and social insecurities cause rifts in their lives. I use R.W. Connell’s theory of gender relations and link it with the notions of precarious masculinity and masculinity crisis to explore this process among Afghan men through... https://escholarship.org/uc/item/7g60q2fv Fri, 9 Oct 2026 00:00:00 +0000 Ozdemir, Cetin https://escholarship.org/uc/item/7f02t1zb This dissertation examines how three contemporary Latin American women writers use alliances between women and nonhuman animals to interrogate the interconnected systems of patriarchal, racial, and colonial domination. Through close readings of Guadalupe Nettel's "El Matrimonio de los Peces Rojos,” Samanta Schweblin's "Pájaros en la boca," and Pilar Quintana's novel La Perra, I argue that becoming-animal, theorized by Deleuze and Guattari as a process of mutual transformation between human and nonhuman beings, offers a powerful but limited tool for feminist and ecocritical reading. Becoming-animal was developed to dismantle the fixed, European, masculine philosophical subject, and on its own it does not account for gender or for the colonial conditions of Latin America. I therefore read it not as a universal framework but as one situated tool among several, placing it in contact with ecofeminism and decolonial feminism, traditions that begin from situated and collective experience.... https://escholarship.org/uc/item/7f02t1zb Fri, 9 Oct 2026 00:00:00 +0000 Deleon-Zemke, Ana Leticia https://escholarship.org/uc/item/7cs6t5dg Deforestation in the Brazilian Amazon is driven by a multitude of complex factors, including market demand for forest resource intensive goods and national policy decisions. Previous literature has highlighted agricultural production of goods such as soy and beef as a key driver of deforestation in the Amazon, though there remains some disagreement over the relevance of international markets. Literature has also identified punitive measures like fines as potentially influential approaches to reducing illicit forest clearing, although the credibility of enforcement is an underexplored component of our understanding of fine effectiveness that this paper works to address. While these are both important to our understanding of drivers and solutions to deforestation, this paper goes further to begin clarifying how the interaction between exporting agricultural goods and the enforcement of forest management policy influences deforestation outcomes. Utilizing municipality-year panel... https://escholarship.org/uc/item/7cs6t5dg Fri, 9 Oct 2026 00:00:00 +0000 Richardson, Coral https://escholarship.org/uc/item/7b07v1v8 Modern machine learning has advanced rapidly, but much of this progress depends on large amounts of labeled data, computation, memory, storage, and communication. These requirements make state-of-the-art systems expensive to reproduce, adapt, and deploy, limiting participation to organizations with substantial resources. Even when code and model checkpoints are publicly available, the cost of working with them can remain out of reach for many academic laboratories and smaller research groups. This dissertation studies how to reduce these barriers and make advanced machine learning more accessible.The central idea of this dissertation is that efficiency should be considered throughout the full lifecycle of a model. Learning should depend less on expensive supervision. Models and learned representations should require fewer parameters and less storage. Systems should be easier to communicate and deploy on devices with limited memory or bandwidth. Task-specific capabilities should... https://escholarship.org/uc/item/7b07v1v8 Fri, 9 Oct 2026 00:00:00 +0000 Pourahmadi-Meibodi, Kossar https://escholarship.org/uc/item/7852z69h This qualitative study examined how higher education chief executive officers (CEOs) affiliated with the Central Valley Higher Education Consortium (CVHEC) conceptualize and enact equity-minded leadership and engage in regional collaboration to advance postsecondary attainment in California’s historically underserved Central San Joaquin Valley. Guided by equity-minded leadership and collective impact frameworks, the study explored how CEOs define equity, translate equity commitments into practice, and sustain cross-institutional collaboration. Using a qualitative single-case, multi-site design, the study drew on semi-structured interviews with 12 CVHEC-member CEOs representing community colleges, community college districts, and public universities. Thematic analysis identified four interrelated themes: (1) equity as an institutional practice, embedded through data, strategy, and accountability; (2) humanistic and adaptive leadership under constraint, characterized by student-centered... https://escholarship.org/uc/item/7852z69h Fri, 9 Oct 2026 00:00:00 +0000 Elizondo, Geraldine Panelo https://escholarship.org/uc/item/77n265n9 Objective identification of low-pressure systems (LPSs) in large-scale datasets, such as reanalyses and Earth system model outputs, is essential for understanding their physical characteristics, evaluating their representation in numerical models, and assessing their historical variability and projected future changes. Among all types of LPSs, tropical cyclones (TCs) have received the greatest attention because of their destructive impacts throughout their life cycles. Despite substantial advances in objective feature tracking, challenges remain in accurately identifying TC features in climate datasets, which can lead to biases in TC climatology and model evaluation. Contemporary TC research spans the entire TC life cycle—from precursor disturbances and genesis to post-tropical evolution. To facilitate such research using reanalyses and Earth system model outputs, an objective framework capable of tracking and classifying TCs throughout all stages of their life cycles is required.To... https://escholarship.org/uc/item/77n265n9 Fri, 9 Oct 2026 00:00:00 +0000 Han, Yushan https://escholarship.org/uc/item/74v48819 The California Community College’s charge is to be proactive and provide equitable educational access to a diverse population of learners within the community (California Community College Chancellor’s Office, n.d.). As the student body continues to diversify, institutions are seeking out ways to serve their students with intentionality and target strategies that can increase enrollment and success for traditionally underserved populations. These strategies move beyond simply thinking about access, and instead, place the onus on the institution to foster environments where students feel supported and valued. Sense of belonging is a critical construct that is connected to servingness and ultimately to students’ persistence and success.This study examined students' sense of institutional belonging at a California community college. Specifically, it explored how belonging is affected by students' experiences with three integral domains of the college-going experience: faculty, student... https://escholarship.org/uc/item/74v48819 Fri, 9 Oct 2026 00:00:00 +0000 Cortes, Jose Luis https://escholarship.org/uc/item/71n7v997 Seasonal labor is vital to the production and sustainability of modern agriculture. Fruits, vegetables, and other high-value horticultural products require intensive labor during short, critical windows for planting, thinning, and harvesting. Without an adequate and timely seasonal workforce, farmers may face significant yield losses, reduced product quality, and increased food loss. Beyond farm productivity, seasonal agricultural labor supports rural economies, sustains export industries, and contributes to food security. Some recent policy debates have been centered around the effectiveness of seasonal foreign workers in agriculture and their potential negative impact on the domestic workforce. This dissertation, in a book-style format, analyzes the Recognised Seasonal Employer (RSE) scheme, a seasonal foreign worker program in horticulture implemented in New Zealand. This dissertation provides a comprehensive view of how this kind of visa program impacts the labor market and... https://escholarship.org/uc/item/71n7v997 Fri, 9 Oct 2026 00:00:00 +0000 Zhang, Ze https://escholarship.org/uc/item/70c0q5fj Glutamatergic synapse development is critical for the functionality of the mammalian brain. This process is thus regulated by many diverse proteins, including the synaptic adhesion G protein-coupled receptors (aGPCRs). The Brain-specific angiogenesis inhibitor (BAI/ADGRB) subfamily is a synaptic aGPCR family broadly associated with conditions involving synaptic development dysregulation, though the exact mechanisms underlying the role that BAI proteins play in these processes remain unknown. In this dissertation, I investigate the function of BAI2/ADGRB2 as a novel regulator of glutamatergic synapse and spine development. I define BAI2’s subcellular and anatomical distribution in neurons and the mouse brain, respectively. I demonstrate that Bai2 knockout (KO) dissociated hippocampal neurons have a reduced number of glutamatergic synapses and mushroom spines compared to paired wildtype (WT) controls. I then further characterize functional and structural changes at synapses, including... https://escholarship.org/uc/item/70c0q5fj Fri, 9 Oct 2026 00:00:00 +0000 Meyer, Christina Maria https://escholarship.org/uc/item/6xn9p7kh Positron Emission Tomography (PET) is a medical imaging modality widely used in clinical practice and biomedical research, including studies of metabolism and cancer. Advances in PET scanner technology enable improved imaging performance and can further accelerate biomedical research. A PET scanner consists of multiple radiation detectors composed of detector material, photodetectors, and readout electronics; therefore, enhancing PET detector performance directly improves imaging resolution and quantitative accuracy. Positrons emitted by radiotracers annihilate with electrons in biological tissue and generate gamma photons. These gamma photons are absorbed by detector material and converted into optical photons, which are subsequently detected by a photodetector attached to the detector material. The detector material is typically a dense, inorganic and luminescent crystal. Two fundamental factors limit PET detector performance: crystal thickness and the critical angle limitation... https://escholarship.org/uc/item/6xn9p7kh Fri, 9 Oct 2026 00:00:00 +0000 He, Xuzhi https://escholarship.org/uc/item/6x9878b6 Silicon carbide (SiC) is a technologically important ceramic whose conventional carbothermal synthesis typically requires high temperatures and extended processing times. This study investigated microwave-assisted synthesis and flash Joule heating (FJH) as rapid processing routes for producing SiC from a mechanically activated SiO₂/C precursor. Silica and graphite powders were combined at a 1:3 molar ratio and subjected to high-energy ball milling to improve reactant contact prior to synthesis. The precursor was subsequently processed by microwave heating at different dwell times and by FJH using repeated capacitor discharge cycles. Phase evolution was evaluated using X-ray diffraction (XRD), with Raman spectroscopy providing complementary characterization of selected FJH products.Both processing routes successfully promoted the formation of cubic β-SiC. Microwave processing showed increased β-SiC development between 5 and 10 min; however, extending the treatment to 12 min resulted... https://escholarship.org/uc/item/6x9878b6 Fri, 9 Oct 2026 00:00:00 +0000 Okrah, Petrina Boatemaa Efua https://escholarship.org/uc/item/6w91h1sq As the number of people aged 65 and older continues to grow, distinguishing typical aging from neurodegenerative disease has become increasingly important. Motor learning refers to the internal processes associated with practice or experience leading to relatively permanent changes in the capability for responding. Understanding the impact of age on motor learning is important for developing rehabilitation strategies, maintaining functional independence, and understanding how aging affects cognition. In this dissertation, I characterize motor learning and its functional neural correlates in younger (18-35 y.o.) and older adults (60-90 y.o.). I first characterized semi-quantitative resting state functional MRI metrics in brain regions relevant to motor learning, namely the cerebellum, in 120 people using a large existing data repository (Human Connectome Project). I then quantified age differences in motor learning between younger versus older participants by administering a motor... https://escholarship.org/uc/item/6w91h1sq Fri, 9 Oct 2026 00:00:00 +0000 Korte, Jessica Anne https://escholarship.org/uc/item/6q43k85j Relationship psychology has historically privileged a worldview belonging to a narrow set of individuals who identify as White, affluent, heterosexual, cisgender, and monogamous couples. Recently, relationship science has begun to seriously attend to the diversity of relationship structures that exist across human nature, including consensual non-monogamy. Consensual non-monogamy (CNM) is an umbrella term referring to a broad relationship practice in which all individuals mutually agree that they can maintain multiple romantic, sexual, and/or intimate relationships concurrently. CNM includes open (i.e., individuals generally agree they can have extradyadic sexual encounters), swinging (i.e., couples engage in sexual partner swapping, often in party settings), and polyamorous (i.e., individuals broadly agree they can build multiple, committed, and long-term partnerships) relationships, including myriad other relationship structures. Nationally representative estimates have suggested... https://escholarship.org/uc/item/6q43k85j Fri, 9 Oct 2026 00:00:00 +0000 Bern, Rose https://escholarship.org/uc/item/6ck5d56d This dissertation studies various quantum aspects of near-extremal black holes, utilizing recent developments in low-dimensional models of quantum gravity and gravitational path integral techniques. In chapter 2, the one-loop determinant of metric fluctuations for the Kerr black hole is computed in its near-horizon region. The zero modes of the fluctuation operator are regulated by turning on a temperature-dependent correction to the background geometry, which leads to important low-temperature corrections to the thermodynamics of these black holes. In chapter 3, this technique is extended beyond the near-horizon region and is applied analytically to the BTZ black hole and numerically to other examples. In chapter 4, the JT gravity effective theory is used to model the process of Hawking radiation, which leads to quantum corrections to the emission spectra of near-extremal black holes. Specifically, the emission of charged radiation by the Reissner-Nordström and Kerr black holes... https://escholarship.org/uc/item/6ck5d56d Fri, 9 Oct 2026 00:00:00 +0000 Rakic, Ilija https://escholarship.org/uc/item/6583b8hb Animal welfare, management, and conservation practices can be supported by an understanding of consistent individual behavioral variation (i.e., personality). For the Northwestern gray wolf (Canis lupus occidentalis), personality research is limited. As detailed in Chapter One, much of the published literature on captive wolf personality has focused on subjects that are hand-reared by or extensively socialized with humans. The objective of my dissertation research was to improve our understanding of the behavior and personality of wolves living in human-managed institutions that are parent-reared and have limited contact with humans. The aim of my first study (Chapter Two) was to determine the influence of season and time of day on activity budgets of parent-reared Northwestern gray wolves (n=10) at the California Wolf Center (Julian, CA) and Oakland Zoo (Oakland, CA). In Chapter Two, I found differences in wolf behavior according to season such that wolves generally spent more... https://escholarship.org/uc/item/6583b8hb Fri, 9 Oct 2026 00:00:00 +0000 Ghavamian, Yasmeen https://escholarship.org/uc/item/639534vz Agriculture remains one of the most hazardous industries for All-Terrain Vehicle (ATV) operators in the United States. Overturn events involving these vehicles are a primary contributor to severe injuries and fatalities, largely due to instability influenced by vehicle configuration, attachments, and operating conditions. This dissertation addresses critical factors affecting agricultural ATV stability through interconnected studies aimed at improving understanding and prediction of rollover risk.The first study investigates the static stability characteristics of agricultural ATVs under varying attachment configurations. A comprehensive analytical and experimental framework was developed to quantify the influence of attachment mass, type, and placement on vehicle center of gravity (CG) location and static stability angles. Results demonstrated that load type significantly affected stability angles in 60% of the tests, with liquid loads associated with greater instability and... https://escholarship.org/uc/item/639534vz Fri, 9 Oct 2026 00:00:00 +0000 Ferreira Lima dos Santos, Fernando https://escholarship.org/uc/item/5z4373m1 Graph sparsification is a well-established technique for accelerating graph-based learning algorithms, which uses edge sampling to approximate dense graphs with sparse ones. However, because the sparsification error is random and unknown, users must contend with uncertainty about the reliability of downstream computations. Although it is possible for users to obtain conceptual guidance from theoretical error bounds in the literature, such results are typically conservative, worst-case oriented, and impractical at a numerical, problem-specific level. Taking an alternative approach, we propose to address these issues from a data-driven perspective by computing empirical error estimates based on bootstrap methods. Unlike theoretical worst-case bounds, the proposed error estimates are highly versatile and adaptively capture the error for the specific input graph. We demonstrate the practical utility of these estimates in four use cases: Laplacian matrix approximation, graph cut queries,... https://escholarship.org/uc/item/5z4373m1 Fri, 9 Oct 2026 00:00:00 +0000 Wang, Siyao https://escholarship.org/uc/item/5w960192 In the field of forensic entomology, insects are generally analyzed by their colonization on a decedent, but various studies have shown that non-insect DNA can be recovered from insects. The larvae of blowflies (Diptera: Calliphoridae) that feed on decaying remains store the decedent’s DNA within their crop, a food-storage organ. The decedent’s DNA can be extracted from the crop and profiled. Previous studies utilize third-instar larvae because they typically have larger crop sizes containing yet undigested food, which has greater DNA yield. However, persistence of DNA when larvae stop feeding and begin transitioning to pupae is less understood. This study investigates the recovery of non-insect DNA of these post-feeding stages and treatments that could improve DNA recovery. Third-instar larvae, prepupae, and pupae that fed on pork were collected and subjected to three extraction treatments: crop/gut contents, homogenized, or whole. Following a standard organic extraction, DNA... https://escholarship.org/uc/item/5w960192 Fri, 9 Oct 2026 00:00:00 +0000 Do, Paulle https://escholarship.org/uc/item/5mx911mn Breast cancer is a heterogeneous disease with multiple molecular subtypes defined by the expression of oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Triple-negative breast cancer (TNBC), defined by the absence of all three receptors, accounts for approximately 10–15% of all breast cancer diagnoses and is associated with a disproportionately poor prognosis. Patients with TNBC face significant clinical challenges, including high rates of tumour recurrence, rapid disease progression, and a propensity for early metastasis. Because TNBC lacks targetable molecular receptors, doxorubicin-based chemotherapy remains the primary systemic treatment; however, intrinsic and acquired chemoresistance is common, and clinical outcomes remain poor. There is therefore a pressing need to identify novel molecular targets and therapeutic strategies for this aggressive disease.TRIM37 (Tripartite Motif Containing 37) is a RING domain-containing... https://escholarship.org/uc/item/5mx911mn Fri, 9 Oct 2026 00:00:00 +0000 More, Ruth Madan https://escholarship.org/uc/item/5kc529fz Granular materials are central to industrial processes such as pneumatic conveying, fluidization, and advanced coating technologies. Yet predicting and controlling particle behavior remains challenging since particles experience a wide range of stresses that drive abrasion, flow resistance, deformation, and deposition. This dissertation presents an integrated experimental and computational investigation of particle mechanics across these regimes, emphasizing how microscopic behavior shapes macroscopic performance.Particle abrasion (the breakage of small surface asperities) is examined in two experimental flowing granular systems designed to isolate different stress environments. In a full ring shear cell, fines concentration and normal force are varied as particles abrade under constant shear. Fines accumulate over time in a decelerating manner, however periodic fines removal produces a linear abrasion rate, revealing a cushioning effect. A complementary single pass impact system... https://escholarship.org/uc/item/5kc529fz Fri, 9 Oct 2026 00:00:00 +0000 Gallegos Tovar, Alejandro https://escholarship.org/uc/item/5jk9w3j3 As electricity markets decarbonize, the increased reliance on variable renewable energy challenges grid operators' ability to balance supply and demand. Solar and wind generation depend on resource availability and peak at midday and overnight, respectively, when demand is relatively low. To meet spikes in net demand, operators dispatch flexible but emissions-intensive thermal generators, which are commonly sited in population-dense urban areas. Additionally, locations with the greatest renewable generation potential are far from urban demand centers, increasing the frequency of transmission line congestion and localized curtailment. The temporal and spatial mismatch between renewable supply and demand reduces the productivity of solar and wind generators while perpetuating the reliance on conventional thermal generators. Utility-scale electricity storage promises to mitigate the inefficiencies of intermittent renewable generation by allowing owners to arbitrage electricity across... https://escholarship.org/uc/item/5jk9w3j3 Fri, 9 Oct 2026 00:00:00 +0000 Dudek, Matthew Edward https://escholarship.org/uc/item/5j40c67k In our climate-change present, one in which the shifting planetary reality challenges human conceptions of human and nonhuman, Traumatic Ecosystems: Trauma and the Environment in African Literature and Film reads African literature and film and asks: How do human affective relations with the nonhuman shape our experiences of trauma? This question triangulates three areas of study that in the past have only collaborated in pairs: Environmental Humanities, African Literature, and Trauma Studies. Literature and film from African countries offer a unique archive for this project. Colonialism, internecine conflicts, and globalization have thrown many African countries into what theorist Achille Mbembe has called a “quasi-permanent” state of trauma, and the literature from these countries often excavates the complicated and compounding traumatic effects of historical and systemic violence against humans and nonhumans. Because most scholars regard trauma as an anthropocentric event,... https://escholarship.org/uc/item/5j40c67k Fri, 9 Oct 2026 00:00:00 +0000 Miller, Jeremiah https://escholarship.org/uc/item/5g75j2wt This dissertation uses a combination of experimental and elicitation methods to examine subject and object marking in Konkani. Konkani is an understudied Indo-Aryan (IA) language spoken in the state of Goa and along the Konkan coast of India. This dissertation adds to the body of scholarship of this understudied language by examining three features of subject and object case marking common in the IA language family, but not yet well studied in Konkani–differential object marking (DOM), split ergativity, and dative subject constructions. The primary objective of this dissertation is to provide detailed and systematic descriptions of these three constructions and place them in the larger context of the IA language family. The second objective is to determine the theoretical implications of the Konkani data and evaluate what a theory of case needs to best account for the Konkani data.Findings indicate that Konkani behaves much like other IA languages in relation to subject and object... https://escholarship.org/uc/item/5g75j2wt Fri, 9 Oct 2026 00:00:00 +0000 Gomes, Melissa Ann https://escholarship.org/uc/item/5fg3z7c5 As interest in grazing for wildfire fuel reduction grows, it is important to understand how cattle grazing is used and what limits its effectiveness. We analyzed 79 responses from ranchers, agency land managers, and other rangeland professionals in California’s Central Coast region to a 2023 survey about grazing for fuel reduction: its perceived effectiveness, goals and practices, barriers, and information needs. Most respondents considered grazing effective for wildfire fuel reduction, primarily through fine-fuel reduction. Among those who used it, 72% set specific goals, most often herbaceous biomass targets such as residual dry matter, and most combined grazing with other strategies, especially mown fuel breaks and shrub removal. Seventy-eight percent reported that grazing for fuel reduction was always or usually compatible with other management priorities, with lower compatibility reported by agency respondents. Rather than conflict with other management priorities, lack of... https://escholarship.org/uc/item/5fg3z7c5 Fri, 9 Oct 2026 00:00:00 +0000 Peterson, Rowan https://escholarship.org/uc/item/5ds1w5wn The installation and performance of geotechnical structures such as piles, anchors, and suction caissons are governed by the skin friction mobilized at soil–structure interfaces. Conventional surfaces typically mobilize slightly greater skin friction in compression than tension, leading to a fundamental trade-off: a high skin friction translates to greater capacity but also leads to greater installation forces, while a low skin friction is beneficial for installation but can result in a limited ultimate capacity and excessive movements. Inspired by the ventral scales of snakes, which generate smaller friction when moving in the caudal direction (along the scales) than in the cranial direction (against the scales), this dissertation investigates the direction-dependent shear behavior of snakeskin-inspired surfaces across a broad range of soils, drainage conditions, and structural applications through interface element testing and centrifuge physical modeling.Interfaces between... https://escholarship.org/uc/item/5ds1w5wn Fri, 9 Oct 2026 00:00:00 +0000 Kim, Hyeon Jung https://escholarship.org/uc/item/5dn4d8k0 Sri Lanka’s 2021 ban on agrochemicals – and subsequent country-wide rice yield loss – offers a rare opportunity to study the components of yield resiliency during system-wide transitions away from synthetic agricultural inputs. We combine a six-year Sentinel-2 satellite based remote sensing analysis with semi-structured farmer interviews to assess heterogeneous yield impacts, recovery rates and post-ban adaptation strategies among rice farms in Sri Lanka’s Anuradhapura District. Using Normalized Difference Red Edge (NDRE) and a panel of 100,000 pixels, we developed three tools for measuring rice farm productivity changes before, during and after the ban. In parallel, we analyzed farmer interview responses through partitioning-around-medoids cluster analysis to identify farm typologies linked to farm attributes, reported yield loss, and yield recovery times. Both methods found that farms with the lowest pre-ban productivity experienced the smallest relative yield losses and fastest... https://escholarship.org/uc/item/5dn4d8k0 Fri, 9 Oct 2026 00:00:00 +0000 Heather, Alexis Rai https://escholarship.org/uc/item/58t4s30v Background: Lung cancer remains the leading cause of cancer deaths in the United States despite evidence demonstrating that lung cancer screening (LCS) using low-dose computed tomography (LDCT) can reduce mortality through early detection. In 2021, the United States Preventive Services Task Force (USPSTF) expanded LCS eligibility criteria to increase access to screening among high-risk eligible individuals. However, limited research has examined the early implementation of the revised guidelines and the multilevel factors influencing LCS uptake following the expansion of the guidelines. The purpose of this dissertation was to examine barriers, facilitators, and factors associated with LCS uptake and completion following implementation of the 2021 USPSTF guidelines. Methods: This dissertation utilized a mixed-methods approach across three studies. Chapter 1 consisted of a Consolidated Framework for Implementation Research (CFIR) guided literature review examining multilevel... https://escholarship.org/uc/item/58t4s30v Fri, 9 Oct 2026 00:00:00 +0000 Rios, Lucy https://escholarship.org/uc/item/56q0j8p7 Despite extensive research demonstrating that caregiver-infant interactions support infants’ learning and development (Bornstein, 2017; Tamis-LeMonda et al., 2008; Yu & Smith, 2016), less is known about how caregivers’ behaviors vary across cultural and linguistic contexts. Research examining caregiver-infant interactions has demonstrated that caregivers’ behaviors are related to infants’ attention and engagement with objects and events in their environment (Tamis-LeMonda et al., 2012; Yu & Smith, 2016). However, less is known about how caregivers’ acculturation and behaviors contribute to the organization of caregiver-infant interactions and infants’ responses. The current dissertation examined how caregivers’ communicative behaviors and acculturation as well as linguistic experiences relate to infants’ attention and engagement during interactions. Study 1 examined Spanish-English bilingual and English-speaking monolingual caregivers’ speech and gesture behaviors... https://escholarship.org/uc/item/56q0j8p7 Fri, 9 Oct 2026 00:00:00 +0000 Ramirez Barajas, Andrea https://escholarship.org/uc/item/52c1k9kx LaNiGa2 presents an intriguing case of superconductivity in which the symmetry of the superconducting state remains under debate. It is an intermetallic superconductor with a relatively low transition temperature of Tc ≈ 2.1 K. Muon spin resonance (μSR) measurements have reported evidence for spontaneous internal magnetic fields below Tc, suggesting possible time-reversal symmetry breaking (TRSB) in the superconducting state by Hillier et al in 2012. An unconventional fully gapped triplet pairing state was subsequently proposed by Weng et al in 2012. In this work, we present comprehensive nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements of LaNiGa2 in both the normal and superconducting states. NMR and NQR measurements of LaNiGa2 reveal no evidence for strong electronic correlations or magnetic fluctuations in the normal state. The Korringa ratios at both the 139La and 69Ga sites remain nearly temperature independent and close to the uncorrelated... https://escholarship.org/uc/item/52c1k9kx Fri, 9 Oct 2026 00:00:00 +0000 Sherpa, Phurba https://escholarship.org/uc/item/51w3t0n4 This dissertation examines Rosario Ibarra de Piedra’s human rights activism and its convergence with the founding and development of Comité Eureka between 1974 and 1994. Following the forced disappearance of her son during Mexico’s counterinsurgency period, Ibarra transformed a personal quest for justice into a broader movement that challenged state repression, demanded accountability, and brought the issue of forced disappearance into the Mexican public sphere. Her activism helped elevate the issue in national media and political discourse, contributing to the development of a human rights framework that reshaped public debate in late twentieth-century Mexico.Drawing on sources from the Museo de la Memoria Indómita archive, this study traces the growth of activist networks led by relatives of the disappeared and analyzes their efforts to document abuses, mobilize public opinion, and pressure the Mexican government. I argue that Ibarra and the organizations she helped build expanded... https://escholarship.org/uc/item/51w3t0n4 Fri, 9 Oct 2026 00:00:00 +0000 Ulloa García, Francisco Javier https://escholarship.org/uc/item/4rm8848b Many modern data-intensive distributed systems, such as data analytics pipelines, microservicebased backends, and networked internet-of-things devices, communicate through asynchronous data streams that are implicitly or explicitly bound by rate limits (e.g., “at most 100 requests per second”); for instance, these limits may arise as the bandwidth of a network connection, the processing capacity of a node, or as explicit api limits (such as GitHub’s api limits or llm query and token limits). The rate limits of data streams have implications for system stability and performance, but reasoning about their behavior can be difficult; to this end, we introduce KARate, an algebraic model of asynchronous streaming rate limits that enables compositional and explicit static reasoning about rate-related stream behavior.KARate is grounded in the theory of regular languages; we explore its formal expressiveness and prove that it extends the Kleene algebra axioms. Using these axioms and a... https://escholarship.org/uc/item/4rm8848b Fri, 9 Oct 2026 00:00:00 +0000 Du, Lucas Zou https://escholarship.org/uc/item/4q61v266 Weed management is a major limitation in organic perennial crop systems, where effective postemergence weed control options are limited and repeated tillage, mowing, and hand weeding can be costly or disruptive. Electrical weed control (EWC) is a non-chemical technology that delivers high-voltage current through contacted plant tissues, causing thermal and cellular damage. The research outlined in this dissertation evaluated EWC as a weed management tool for California perennial specialty crops, with emphasis on organic tree crops and highbush blueberry. Field experiments conducted from 2023 to 2025 first examined how travel speed, power setting, weed species, and moisture-related field conditions affected EWC efficacy. Annual weed species such as hairy fleabane, redroot pigweed, little mallow, and California burclover were highly susceptible, whereas field bindweed control response to EWC was more variable. Slower travel speed was the most consistent factor improving control,... https://escholarship.org/uc/item/4q61v266 Fri, 9 Oct 2026 00:00:00 +0000 Zhen, Tong https://escholarship.org/uc/item/4q00t1zr Sea breezes are diurnal coastal circulations that develop due to the temperature difference between the land and the sea, affecting near-surface meteorology and air quality in coastal regions. The Arabian/Persian Gulf (‘Gulf’) is a predominantly arid region that has experienced a considerable warming in its surface air temperatures. This study conducts a long-term analysis of the characteristics and trends of sea breezes in the northern Gulf using 52 years (1973–2024) of surface meteorological observations and reanalysis data. The findings show an easterly (onshore) reversal of the wind during the afternoon; however, the onshore component is relatively weak due to the dominant opposing N-NW wind component and the potential impact of the perpendicular breeze from Kuwait Bay. The intensity of the sea breeze shows a notable seasonal variation, with the strongest onshore component occurring in spring and the weakest in winter. Despite exhibiting the largest land-sea thermal contrast,... https://escholarship.org/uc/item/4q00t1zr Fri, 9 Oct 2026 00:00:00 +0000 Kawiyani, Reem https://escholarship.org/uc/item/4mh3q9qb Color centers are optically active point defects in semiconductor materials, many of them carrying a spin degree of freedom that couples coherently to emitted photons. This makes them a leading candidate for building quantum computers, networks, and sensors, but realizing that promise depends on the interface between the emitter and light. Color centers must be integrated into nanophotonic structures, such as nanopillars that collect their emission efficiently and optical cavities that couple them to a single mode. This dissertation studies the physics of quantum emitters inside such structures along two complementary threads: the direct cryogenic spectroscopy of color centers integrated into silicon carbide nanostructures, and the study of the physics of many-body cavity quantum electrodynamics (CQED) through simulation on superconducting and trapped-ion quantum hardware. The first thread concerns the nitrogen-vacancy (NV) center in 4H silicon carbide integrated into nanopillars.... https://escholarship.org/uc/item/4mh3q9qb Fri, 9 Oct 2026 00:00:00 +0000 Rubin, Alex Holt https://escholarship.org/uc/item/4mg7d248 Many microswimmers propel themselves using flagella, which are thin, threadlike filaments that beat in a periodic wavelike motion. The flagellar beat emerges from the coupled interactions between the surrounding fluid and the active and passive responses of the flagellum. Previous studies have observed qualitative waveform changes with varying fluid rheology. It is thought that this spatiotemporal coordination among motors is due to mechanical feedback on dynein motors. However, the mechanisms of mechanochemical feedback are not well understood, since the motor forces cannot be measured directly. In this dissertation, we explore the effects of fluid viscosity on the flagellar waveforms of Chlamydomonas reinhardtii swimming in Newtonian fluids. First, we quantify changes in the flagellar waveforms in response to varying fluid viscosity, using (i) shape mode analysis on a dataset of ten cells swimming in fluids with different viscosities, and (ii) a full swimmer simulation... https://escholarship.org/uc/item/4mg7d248 Fri, 9 Oct 2026 00:00:00 +0000 Gutierrez, Kelli Elizabeth https://escholarship.org/uc/item/4kw5c68d A combined hydrologic and bio productivity model is developed to simulate effects of changing water release timing and quantity on an ephemeral floodplain to optimize habitat and productivity over a 30-day period. Floodplains are complex and dynamic habitats supporting migratory fish, birds, and amphibians. However, testing hypothesis empirically can be difficult, time-consuming, and expensive in such dynamic systems. Exploring bio productivity responses to inundation is well suited to process-based modeling. This thesis organizes the problem in terms of inflow quantity, water temperature, floodplain shape and construction, and 30-day hydrograph design to help inform management decisions and pose better questions for managing these environments. A simulation model explores effects of these factors on primary productivity. These variables are then explored with optimization to identify floodplain hydrograph shapes that maximize primary productivity with varying physical, ecological,... https://escholarship.org/uc/item/4kw5c68d Fri, 9 Oct 2026 00:00:00 +0000 Braun, Jacob Nathanial https://escholarship.org/uc/item/4h0244tg Agriculture provides food, fiber, and energy that are fundamental to human well-being. Yet agricultural production and policies can generate externalities, including health risks from chemical use and environmental damages from land-use change. These impacts often extend far beyond the locations where agricultural decisions are made, transmitted through interconnected natural and economic systems. This dissertation examines how hydrological networks and global commodity markets propagate agricultural externalities across space, creating consequences for populations and ecosystems far removed from production and consumption sites. One essay in the dissertation investigates the health impacts of agricultural water pollution by examining glyphosate, the world's most widely used herbicide. Leveraging hydrological flow patterns and variations in upstream glyphosate use across watersheds and time to identify causal effects, I show that glyphosate affects populations far downstream... https://escholarship.org/uc/item/4h0244tg Fri, 9 Oct 2026 00:00:00 +0000 Chen, Tzu-Hui J. https://escholarship.org/uc/item/49p560cr Although the genus Phytophthora was formally described in the late 19th century and there are 261 valid species described to date, research has historically focused on high-profile model organisms like P. infestans or regulated quarantine pathogens like P. ramorum. Consequently, a significant knowledge gap persists regarding the biology and genomics of many lesser-known opportunistic species, particularly those occupying riparian ecosystems. This thesis addresses these limitations through a multipronged approach, investigating the genus across both pathological and genomic fronts. On the biological front, lab-controlled pathogenicity trials evaluating 41 Phytophthora species against four California Native hosts utilized a water-consumption Vitality Index. This approach demonstrated that while some of these riparian species compromise plant health by reducing water consumption, the infection often remains entirely asymptomatic with continued plant growth. On the genomic front,... https://escholarship.org/uc/item/49p560cr Fri, 9 Oct 2026 00:00:00 +0000 Jennings, Krysta Cavelle https://escholarship.org/uc/item/48b609kn Machine learning has been productive in seismology where labeled examples are dense. Forecasting is not one of those problems. This dissertation argues that two constraints bind before any question of architecture arises. Instrumental catalogs are too short to supply the labeled examples a learned model requires, and a raw catalog carries no state variable to quantify where a region sits in its seismic cycle. Chapter 2 takes up the first constraint through models capable of generating synthetic catalogs. It presents an independent fit of the epidemic-type aftershock sequence (ETAS) model to the Southern California catalog together with a characterization of the synthetic ensemble that fit produces, and it closes on an original result showing that geometric interference between successive bursts in loopless invasion percolation drives exponent drift on a scale comparable to observed b-value variability. Chapter 3 takes up the second. It optimizes the two free parameters of an exponential... https://escholarship.org/uc/item/48b609kn Fri, 9 Oct 2026 00:00:00 +0000 Baughman, Ian https://escholarship.org/uc/item/4859d9dg Increasing summer heat has increased berry shriveling during the late ripening, negatively affecting grape yield and quality. An automated misting system based on temperature and wetness thresholds was developed to assess the overall efficiency of misting treatments by monitoring fruit surface temperature, physiological indicators, cell viability and fruit chemical composition in mature Cabernet Sauvignon vines. The misting system was primarily operated during periods of high temperatures, reaching a maximum of 19.31 gal/vine/day during heatwaves, while at lower ambient air temperatures (<95°F), when sun-exposed berry surface temperatures could still exceed threshold, misting was mainly maintained at 3–5 gal/vine/day. The misting system reduced berry surface temperature by 3–5 °F while improving the leaf gas exchange and vine water status. Misting also significantly enhanced cell vitality, maintaining it at 65% at harvest, which was 19.7% higher than the control. The shriveling... https://escholarship.org/uc/item/4859d9dg Fri, 9 Oct 2026 00:00:00 +0000 Liu, Guodong https://escholarship.org/uc/item/44h2b4z2 Single-particle cryo-electron microscopy reconstructs a three-dimensional molecule from many extremely noisy two-dimensional views. One way to reduce noise in an individual view is to learn the variation in the clean particle images and the background noise from the full collection of views. Covariance Wiener filtering uses this information to estimate the underlying clean projection from a noisy image. The filter requires an estimated mean image and two covariance matrices: one describing variation among the clean projections and the other describing the noise. The objective of this thesis is to estimate both covariances from processed particle images and their known contrast transfer functions, which describe how the microscope modifies the images. Pixels near the corners of an image box are treated as observations of the background, where particle signal is assumed to be negligible. Correlations measured in these pixels are used to estimate how the noise varies across the image.... https://escholarship.org/uc/item/44h2b4z2 Fri, 9 Oct 2026 00:00:00 +0000 Farrow, Caleb Harmon https://escholarship.org/uc/item/42s1m4c7 Coastal and fishing communities depend on marine resources whose productivity is increasingly shaped by climate-driven environmental change, exposing local economies to overlapping ecological and economic uncertainty. This dissertation adopts the framework of coupled human-environmental systems to examine how the linkage between marine resources and the communities that depend on them is sustained under such uncertainty. Spanning production-frontier estimation, dynamic bioeconomic modeling, and causal panel time-series inference, the three essays trace this linkage through three channels: (1) the sectoral structure of local economies tied to the resource sector, (2) the active management of degraded ecosystems, and (3) the transmission of harvest-sector shocks to local non-fishing economies. The first essay examines how diversification of fisheries and of the broader industrial base shapes economic growth and stability in Alaska’s fishing communities. Both forms of diversification... https://escholarship.org/uc/item/42s1m4c7 Fri, 9 Oct 2026 00:00:00 +0000 Kim, Kyumin https://escholarship.org/uc/item/40g0q9cx Scalable quantum networks for distributed quantum computing and global quantum communication require high-fidelity spin-photon interfaces integrated with foundry-compatible photonic hardware. Color centers in silicon carbide (SiC) have emerged as a promising solid-state platform due to their isolated deep-level encapsulation, long-lived spin coherence, near telecom emission, and the host material's commercial 200 mm wafer availability. Enhancing the performance of these quantum emitters requires nanophotonic integration to overcome low extraction efficiency owing to total internal reflection, explore light-matter interactions, and perform on-chip quantum information processing. However, photonic integration of quantum-grade SiC has been fraught with challenges in thin-film material quality and scalability limits in conventional bulk fabrication techniques. To overcome these manufacturing limitations, this dissertation establishes a comprehensive theoretical, fabrication,... https://escholarship.org/uc/item/40g0q9cx Fri, 9 Oct 2026 00:00:00 +0000 Saha, Pranta https://escholarship.org/uc/item/403155ss This dissertation studies how unusually large foreign capital inflows accumulated during economic expansions shape macroeconomic adjustment after GDP peaks. Using quarterly cross-country panels, peak-based measures of excess gross liability inflows, and state-dependent local projections, the three chapters connect pre-peak external financing conditions to the subsequent paths of output, credit and debt, and sectoral employment. Together, they show that the legacy of inflow-intensive expansions is delayed, composition-dependent, and visible across both financial and real margins.Chapter 1 documents an intertemporal drag of capital inflows. Excess inflows accumulated during expansions are associated less with an immediate collapse at the peak than with weaker medium-horizon output paths. Aggregate inflows mask offsetting responses across foreign direct investment, portfolio equity, portfolio debt, and other investment, while the effectiveness of exchange-rate, reserve, and capital-control... https://escholarship.org/uc/item/403155ss Fri, 9 Oct 2026 00:00:00 +0000 An, Sion https://escholarship.org/uc/item/3th8q0zj This thesis investigates tunable electromagnetic wave manipulation in complex oxide materials, focusing on strontium titanate (SrTiO₃, STO) and lanthanum strontium manganite (La1-xSrxMnO3, LSMO) deposited on STO. The work combines experimental characterization and electromagnetic modeling to study how thermal effects modify material permittivity and wave propagation. The first part of this thesis examines the temperature-dependent permittivity and polarization control of STO in the terahertz spectrum. Terahertz time-domain spectroscopy is used to measure and model the complex permittivity and polarization rotation of STO as a function of temperature. This model is then applied to infrared birefringence measurements, showing that thermal gradients in STO can produce a tunable anisotropic optical response.The second part of this thesis focuses on the thermal response of LSMO/STO heterostructures. A broadband model of the complex permittivity of LSMO is developed using ellipsometry,... https://escholarship.org/uc/item/3th8q0zj Fri, 9 Oct 2026 00:00:00 +0000 Eravelli, Praneeth Rao https://escholarship.org/uc/item/3rg4z7jf Many cultivars of almond (Prunus dulcis Mill. D. A. Webb) suffer from a disorder known as non-infectious bud failure in which preformed meristematic tissue becomes necrotic during dormancy, then fails to emerge in the following growing season. Non-infectious bud failure is a noteworthy disorder in perennial crops due to its miotic inheritance through asexual propagation and variance in severity between genetic clones. While the cause of the disorder is unknown, previous research has shown possible connections between DNA methylation and symptoms of the disorder. Non-infectious bud failure has been mitigated through propagation from basal epicormic buds, which show reduced non-infectious bud failure in clonal progeny relative to the axillary canopy buds typically used for propagation. In this dissertation, we explored several possibilities of detecting differences in DNA methylation and expression to develop potential biomarkers for non-infectious bud failure in almonds. ... https://escholarship.org/uc/item/3rg4z7jf Fri, 9 Oct 2026 00:00:00 +0000 Hazzard, William R https://escholarship.org/uc/item/3rd2z1vg Every day, across most species, animals process and integrate sensory information from multiple modalities (multimodal processing) to help them interact with their environment successfully and perform a wide range of behaviors. These behaviors demonstrate how perception and action are intimately linked. We rely on our senses to seek out food and shelter, to navigate through obstacles, and to avoid potential danger. While a single sensory cue from one modality is sometimes enough to guide our actions, cues from more than one modality can be quite beneficial.Multisensory integration, combining sensory cues from multiple modalities into a unified perceptual experience, has been shown to improve behavioral responses, including detection of sensory cues, localization of sensory cues, and response time. Many studies investigating multisensory integration use clear, unambiguous sensory cues, varying only the intensity of the cue. However, in real-world settings, sensory cues are often... https://escholarship.org/uc/item/3rd2z1vg Fri, 9 Oct 2026 00:00:00 +0000 Jordan, Katherine https://escholarship.org/uc/item/3nd8w4qd Motivated by the need to establish a theoretical foundation for statistical inference on manifolds, we study the first-order asymptotic theory for the eigenvalues and eigenvectors of graph Laplacians on manifolds. As a direct consequence, we establish the weak convergence of these spectral quantities. Unlike most related works, our analysis does not impose a multiplicity-one assumption on the eigenvalues, making the framework applicable to general manifold settings. A central challenge arising from nontrivial eigenvalue multiplicities is the clustering of the eigenvalues of smoothed graph Laplacians. To address this issue, we also extend classical operator perturbation theory, which typically focuses on individual eigenvalues, to general spectral subsets. https://escholarship.org/uc/item/3nd8w4qd Fri, 9 Oct 2026 00:00:00 +0000 Bae, Eunseong https://escholarship.org/uc/item/3m55d99p Electrification of end uses, coupled with the integration of renewable energy in electric power systems, is essential to achieving decarbonization goals. With water heating accounting for 15% of greenhouse gas (GHG) emissions in U.S. residential buildings, heat pump water heaters (HPWHs) offer a promising solution for decarbonizing domestic water heating, with two to three times the efficiency of electric resistance water heaters. However, to reduce the cost of electrification for homeowners and to realize the full decarbonization potential of HPWHs, HPWH loads must align with periods of low-cost, clean electricity. This can be addressed by leveraging the inherent load-shifting capability of the built-in storage tank, storing water heated during these desirable periods for later use. Yet, most HPWHs rely on rule-based control (RBC) strategies that maintain a temperature setpoint regardless of electricity cost or grid energy source. While some RBCs can shift HPWH loads using fixed... https://escholarship.org/uc/item/3m55d99p Fri, 9 Oct 2026 00:00:00 +0000 Dela Rosa, Loren Faith Ruiz https://escholarship.org/uc/item/3gd7f08t Multi-principal element alloys (MPEAs) provide a versatile platform for tuning magnetic behavior through compositional control and competing ferromagnetic and antiferromagnetic exchange interactions. This work investigates the composition-dependent structural and magnetic properties of magnetron-sputtered Feₓ(MnCoNi)₁₀₀₋ₓ thin films, with particular emphasis on the evolution of ferromagnetic and antiferromagnetic interactions as a function of Fe concentration.A series of thin films with systematically varied Fe content were fabricated by magnetron sputtering and characterized using X-ray diffraction (XRD), X-ray reflectivity (XRR), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). Temperature- and field-dependent magnetic measurements were performed using VSM to evaluate changes in coercivity and saturation magnetization. Our measurements reveal small, exchange-bias behavior as a function of Fe concentration. To investigate element-specific magnetization,... https://escholarship.org/uc/item/3gd7f08t Fri, 9 Oct 2026 00:00:00 +0000 Nagarajan, Shivashunmugam https://escholarship.org/uc/item/3d95h6xj The defossilization of the chemicals production industry is an important step in the global pursuit of sustainability. This industry leverages catalysis to accelerate the rates of reaction and enhance process outputs. Intermediate species, both stable and reactive, are ubiquitous in these catalytic reaction systems and their importance cannot be understated. Understanding both the identity and evolution of these intermediates in reaction systems is critical for optimizing catalytic performance. Mass spectrometry is specifically well suited to identify and track these intermediate species due to its near-universal detection and short acquisition times. This dissertation will focus on the application of molecular-beam time-of-flight mass spectrometry to both identify and temporally track the evolution of reaction intermediates in complex reaction systems.Molecular-beam photoionization mass spectrometry measurements were performed to obtain the mass spectral fingerprint of methoxymethanol,... https://escholarship.org/uc/item/3d95h6xj Fri, 9 Oct 2026 00:00:00 +0000 Hansen, Niko Artturi https://escholarship.org/uc/item/3cr389hk Archaeological ostrich eggshell (OES) is abundant across African archaeological sites and preserves several isotope systems that can provide evidence of past environments and resource acquisition. Using these values to reconstruct human behavior, however, requires evidence that the shell retains its original isotope composition, a regional baseline that relates strontium isotope values to geographic areas, and an interpretive framework that accounts for ostrich ecology and the human collection and transport of eggs. This dissertation develops that framework and applies it to the Varsche Rivier site complex in southern Namaqualand, South Africa. First, controlled heating experiments demonstrate that the total organic fraction of OES retains interpretable carbon and nitrogen isotope values below approximately 220°C, while carbonate carbon and oxygen isotope values remain comparatively stable through heating to 500°C. The experiments also establish an OES-specific atomic C:N preservation... https://escholarship.org/uc/item/3cr389hk Fri, 9 Oct 2026 00:00:00 +0000 McNeill, Patricia Jannette https://escholarship.org/uc/item/39s5d64h In this thesis, we study cyclic elements in complex finite-dimensional simple Lie algebras. These are significant both in Lie theory and in physical applications such as affine Toda field theory and integrable hierarchies of PDEs. Rather than relying on explicit matrix realizations, this work employs a conceptual approach based on the Cartan-Coxeter correspondence.Specifically, we focus on the adjoint representation and a fundamental representation of minimal dimension (namely, the fourth for f4, the seventh for e7, the eighth for e8, and the first for the remaining types) of simple Lie algebras. We derive explicit trigonometric expressions for the spectra of cyclic elements. The obtained spectra are expressed as unions of rotationally symmetric configurations in the complex plane, with their radii given by trigonometric formulas. Furthermore, we show that, up to scaling, the cyclic spectrum of the minimal fundamental representation listed above is always contained in that of... https://escholarship.org/uc/item/39s5d64h Fri, 9 Oct 2026 00:00:00 +0000 Wang, Houbo https://escholarship.org/uc/item/36s1v0xt This dissertation contains three published bodies of work detailing the introduction of the pentafluorosulfanyl (SF5) group to organic molecules via addition of pentafluorosulfanyl chloride (SF5Cl) across [1.1.0]bicyclobutanes (BCBs). Our laboratory reported the first example of strain-release pentafluorosulfanylation in 2022 by reacting SF5Cl with [1.1.1]propellane, which was inspired from longstanding literature precedent on radical additions of SF5Cl across non-aromatic p-bonds. We postulated that the strained s-bonds of BCBs could also react in a similar fashion due to their high p character and established p-like reactivity. In Chapter 2, the development of synthetic tactics for strain-release pentafluorosulfanylation of 1-substituted [1.1.0]bicyclobutanes (BCBs) is discussed. This work allowed us to access a suite of novel SF5-containing cyclobutanes (SF5–CBs) through polarity mismatched SF5 radical additions and post-synthetic modifications, as well as provided a mechanistic... https://escholarship.org/uc/item/36s1v0xt Fri, 9 Oct 2026 00:00:00 +0000 Stephens, Alexander Mark https://escholarship.org/uc/item/3643q6f9 Many important questions in human evolutionary genetics remain incompletely answered, not from a lack of data quantity, but because the majority of data analyzed have been drawn from a narrow slice of human diversity. Despite the field's well-intentioned efforts to broaden the ancestral diversity of participants included in human genetic association studies and demonstrable progress in generating large-scale diverse-ancestry cohorts, the vast majority of genetic association studies continue to rely on the same set of well-established databases composed primarily of unadmixed, European-ancestry participants (e.g., the UK Biobank, FinnGen, etc.). Indeed, the cumulative ancestry composition of all genome-wide association study participants has remained largely unchanged since the early 2010s. As of writing this dissertation, per the GWAS Diversity Monitor, 88.25% of participants in published genetic association studies are of European ancestry, compared with only 0.27% of African... https://escholarship.org/uc/item/3643q6f9 Fri, 9 Oct 2026 00:00:00 +0000 Meeks, Gillian Louise https://escholarship.org/uc/item/3215s2rh The Industrial Revolution represents major changes in human technological and economic systems. Rapid growth in industry pushed many women to join the workforce and provide for their families. This change not only affected their lives, but major changes in maternal investment, in conjunction with rapid industrialization, had major effects on the lives and health of their children as well. This dissertation investigates these changes through bioarchaeological analyses that estimate breastfeeding patterns and heavy metal exposure in immigrants interred in cemeteries from the San Francisco Bay Area. Archaeometric results are contextualized through the inclusion of historic coroners’ records used to provide understanding of disease and mortality landscapes in rapidly industrializing cities.Studying childhood health in bioarchaeology is often limited by the “osteological paradox”; infant remains represent non-surviving children and are often under-represented due to taphonomic processes,... https://escholarship.org/uc/item/3215s2rh Fri, 9 Oct 2026 00:00:00 +0000 Malarchik, Diana https://escholarship.org/uc/item/3022b9b8 As deep learning models have grown deeper and more complex, and as they have been deployed in high stakes decision-making settings, their lack of transparency has become an increasingly urgent problem. This dissertation addresses that problem across two domains, medical artificial intelligence (AI) and large language models (LLMs), with the shared goal of improving our ability to understand, characterize, and ultimately trust the outputs of black box models. The first part of this work lies within a broader effort to build AI-driven, patient-specific synthetic data capable of supporting tasks like diagnosis. This dissertation lays the groundwork for that goal in two ways. First, it shows that combining physiologically heterogeneous data sources in a shared latent space can improve the diagnostic performance of a deep learning model on acute respiratory distress syndrome (ARDS). Second, it demonstrates the ability of optimal transport-based models to generate synthetic chest... https://escholarship.org/uc/item/3022b9b8 Fri, 9 Oct 2026 00:00:00 +0000 Broecker, Stefan https://escholarship.org/uc/item/2tm3t1nc Tumor-reactive T cells are clinically valuable but often exist at very low frequencies in systemic circulation, sometimes comprising as little as 0.05% of heterogeneous immune-cell populations, making their identification and isolation challenging. In this thesis, a PDMS–glass microfluidic platform was developed to evaluate whether controlled fluid shear could be used to preferentially enrich antigen-specific T cells from complex immune-cell mixtures. Using Jurkat C6 cells expressing a TCR specific for MART-1 as a model target population and peripheral blood mononuclear cells (PBMCs) as a nonspecific background population, MART-1 pMHC was immobilized on the glass surface, and cell capture was evaluated across C6 Jurkat spike-in frequencies ranging from 0.05% to 50% under varying shear stresses. Across all shear stresses and spike-in conditions tested, captured-cell purity remained above the initial C6 spike-in fraction, demonstrating that the device preferentially enriched MART-1-specific... https://escholarship.org/uc/item/2tm3t1nc Fri, 9 Oct 2026 00:00:00 +0000 Fu, Michelle https://escholarship.org/uc/item/2th600rr There are over 1.2 million people with HIV (PWH) in the United States, with inequities embedded in the HIV epidemic since its earliest years. Disparities persist across the HIV continuum including screening and diagnosis, treatment, viral suppression, and complications; and are influenced by social determinants of health including race/ethnicity, socioeconomic status, sexual and gender minority status, insurance, and geographic location. As combination antiretroviral therapy (cART) became FDA approved in 1996, HIV became a chronic, manageable disease, resulting in a growing and aging population of PWH. As overall survival in PWH has improved, cancer has emerged as a major comorbidity, yet there is a paucity in published evidence addressing the cancer needs of PWH. Lymphoma is among the most common cancers in PWH, with elevated risk due to underlying immunosuppression and viral co-infections (e.g., Epstein-Barr virus). HCT is a potentially curative treatment modality for relapsed... https://escholarship.org/uc/item/2th600rr Fri, 9 Oct 2026 00:00:00 +0000 David, Kurt Anthony https://escholarship.org/uc/item/2sw2t76p This dissertation is comprised of five chapters including four published bodies of work pertaining to strain-release pentafluorosulfanylation and its application toward exploring the concept of “hybrid bioisosterism.” Previous method development involving SF5Cl—a known radical SF5 transfer reagent—focused on addition across “-reactants” such as alkynes, alkenes, and diazo compounds. Herein, analogous reactivity is shown to translate directly to SF5Cl addition across strain-release reagents including [1.1.1]propellane and [1.1.0]bicyclobutanes (BCBs). These methods provide access to SF₅-containing saturated carbocycles and establish a pathway for exploring the concept of hybrid bioisosterism, in which multiple bioisosteric elements are implemented simultaneously within a single molecular framework.The introductory Chapter 1 sets the foundation for this work by exploring the concept of bioisosteric replacements, followed by how the pentafluorosulfanyl (SF₅) group and saturated... https://escholarship.org/uc/item/2sw2t76p Fri, 9 Oct 2026 00:00:00 +0000 Buldt, Jón Atiba https://escholarship.org/uc/item/2rm8881b Worldwide, over 15% of couples have difficulty conceiving a child. Long-term fertility in males is governed by spermatogenesis, the developmental program responsible for producing mature sperm. Sperm were once viewed primarily as carriers of paternal DNA, but they also carry epigenetic information that can influence fertilization and early embryonic development. This information is established through the remodeling of chromatin, the combination of DNA and associated proteins, as germ cells develop. However, why and how molecular regulators and environmental conditions shape the epigenome remains incompletely understood.To address this gap in knowledge, I investigated how intrinsic and environmental factors influence the epigenetic trajectory of the male germline. I approached this biological question using two complementary mouse models: genetic deletion of a chromatin regulator, ATF7IP2/MCAF2, and dietary folate deficiency. By independently assessing each model using a combination... https://escholarship.org/uc/item/2rm8881b Fri, 9 Oct 2026 00:00:00 +0000 Esparza, Jasmine Marie https://escholarship.org/uc/item/2rc7p32r Decentralized multi-agent decision-making systems have long underpinned the architecture of modern economies, real-world markets at all scales, and networked environments. These systems are characterized by multiple rational agents, each driven by distinct utility functions and local objectives, operating under information asymmetry and constrained, ego-centric perspectives. Within these shared environments, agents must navigate a balance between individual optimization and collective outcomes, often without any centralized signals. Such conditions give rise to distinctive challenges, including combinatorial computational complexity, non-stationarity induced by the concurrent learning and confounding adaptations of other agents, and the need for coordination under incomplete information and strategic uncertainty. These intricacies complicate the design of mechanisms and learning algorithms that reliably produce efficient, stable, and desirable collective outcomes. Recent... https://escholarship.org/uc/item/2rc7p32r Fri, 9 Oct 2026 00:00:00 +0000 Huh, Dom https://escholarship.org/uc/item/2q06z15f The population of Oaxaqueños in California has been increasing over the years. In the Central Coast of California, specifically in Santa Barbara County this number is estimated to be up to 15,000 with the most populated city being Santa Maria. The City of Santa Maria however, has a history of not being very diverse, but due to its agriculture many immigrate to the area seeking job opportunities. When immigrating, many folks who immigrate from Oaxaca continue to be part of their transnational community. This study explores the strategies a transnational community from Oaxaca, Mexico have developed to participate and engage in Santa Maria. The study looks at the experiences in participating, any barriers, and how they may overcome those barriers to participating. Additionally, this study also aimed to gain insights from the city government regarding transnational communities from Oaxaca. In total there were eleven participants in this study, nine being participants from Oaxaca and... https://escholarship.org/uc/item/2q06z15f Fri, 9 Oct 2026 00:00:00 +0000 Rodriguez-Alonso, Jennifer https://escholarship.org/uc/item/2m98b9tm The behavior of cohesionless granular materials is governed by particle-scale interactions. As loads are applied, interparticle contacts form force chains that distribute stress throughout the soil mass and provide resistance to deformation and shear. This shear resistance is essential for many geotechnical solutions. Specifically, the shear resistance developed at soil-structure interfaces is a crucial design consideration for systems such as deep foundations, retaining structures, geosynthetics, and tunnels. Developing a micro-mechanical perspective of these systems can improve design. The discrete element method (DEM) provides a means of obtaining this understanding by enabling direct examination of particle-scale behavior. This dissertation presents a series of DEM investigations that connect the macroscopic response of granular materials and soil–structure interface shear behavior to their underlying micro-mechanics. The resulting insights provide new explanations for experimentally... https://escholarship.org/uc/item/2m98b9tm Fri, 9 Oct 2026 00:00:00 +0000 Nguyen, Damon Huu https://escholarship.org/uc/item/2kh3x6jb Bicycling is a sustainable mode of transportation that provides many benefits including improved physical and mental health and reduced car travel. Despite the benefits of bicycling, the share of trips made by bicycles for transportation in the US remains substantially lower than in other developed nations. This dissertation examines the opportunities and challenges associated with expanding bicycling as a mode of transportation in the US. Specifically, the dissertation investigates the potential of personal electric bicycle (e-bike) adoption to increase bicycling and reduce automobile use, particularly among low-income and disadvantaged populations. In addition, it examines barriers to sustained bicycling, focusing on bicycle theft and post-theft bicycling outcomes.In the first study, presented in Chapter 2 of this dissertation, I examine the effects of personal e-bike adoption on bicycling, automobile use, and associated greenhouse gas (GHG) emissions, particularly among low-income... https://escholarship.org/uc/item/2kh3x6jb Fri, 9 Oct 2026 00:00:00 +0000 Agarwal, Swati https://escholarship.org/uc/item/2jg466p6 Fusarium basal rot (FBR) affects garlic globally, including in California, where it causes increasingly severe damage in the field and following storage. With cold storage durations of up to one year, fresh market garlic production is particularly vulnerable. It causes various degrees of basal plate and clove rot, additionally shoot rot or leaf chlorosis may also be present. Fusarium proliferatum is the main pathogen, but F. oxysporum and F. falciforme also cause disease. Without intervention, seed clove infection rates with F. proliferatum, can exceed 80%. Currently there are no effective treatment recommendations for reducing losses.In preliminary studies, high sodium hypochlorite (NaClO) concentrations and long treatment duration reduced seed infection. At 2% NaClO for 30 min, we observed minimal impacts to germination (P = 0.992) in laboratory conditions. We confirmed that prolonged soaking with 2% NaClO for 30 minutes had a trend of reduced Fusarium infection levels in naturally... https://escholarship.org/uc/item/2jg466p6 Fri, 9 Oct 2026 00:00:00 +0000 Briggs, Annika Linnea