36214 research outputs found
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Autonomous Capture of Submerged Plastic Bags
No full textThesis (Master's)--University of Washington, 2025Plastic bags are a major contributor to oceanic macroplastic pollution, presenting serious threats to marine life and ecosystems. As these bags break down into microplastics, the hazards worsen, affecting both marine organisms and human health. This thesis introduces a complete pipeline designed to capture drifting plastic bags using an underwater manipulator. This pipeline could be used for future deployment on autonomous underwater vehicles (AUVs). The system integrates object detection, tracking, and intercept planning to capture drifting underwater objects. Chapter 1 introduces FindingTrash, a vision pipeline combining YOLO and DeepSORT, trained on a curated dataset to detect and track plastic bags. This system is paired with a robotic manipulator to enable reactive grasping. Chapter 2 builds on this by integrating a reachability-based planning strategy that compares predicted drift times with precomputed arm reach times, allowing the robot to select timely interception points. Bag drift was simplified to one degree of freedom to reduce complexity. A simulation of our system tracked and intercepted plastic bags through our test tank, offering a promising solution for automated underwater plastic bag removal
Cost-effectiveness analysis of a household salt substitute intervention on reducing community-wide blood pressure in Northern Peru
No full textThesis (Master's)--University of Washington, 2025Background: Hypertension is the top risk factor for cardiovascular diseases in low- and middle-income countries. Replacing regular salt with potassium-enriched alternatives is a new strategy in resource-constrained settings, but its economic impact is still underexplored. Methods: We conducted a cost-effectiveness analysis of a complex intervention that includes a salt substitute and a social marketing campaign to promote its adoption at the regional level in the Peruvian region of Tumbes. The present analysis considered a lifetime horizon. Intervention costs were obtained from the trial’s audit, and health outcome costs were sourced from the literature. All costs and DALYs were discounted at a rate of 3%. Results: Over the lifetime horizon, we found that the intervention averted 2.46 and 1.51 cases of hypertension and cardiovascular disease events per 100 persons, respectively. The intervention was dominant (better outcomes at lower costs) than the baseline scenario, considering the number of DALYs averted. Sensitivity analyses showed the robustness of our assumptions. Conclusions: Replacing regular salt with a salt substitute was cost-effective for the Tumbes region
Notch-activated basophils support intestinal CD4 T cell fate and function during helminth infection
No full textThesis (Ph.D.)--University of Washington, 2025Parasitic helminth infections affect over 1 billion people worldwide, underscoring the need to study host-parasite interactions for therapeutic intervention. Helminth infection provokes a Type 2 inflammatory response orchestrated by CD4+ T helper 2 (Th2) cells. In the intestine, Th2s elicit an interleukin-13 (IL-13)-dependent “weep and sweep” response from the epithelium to drive parasite clearance. Tissue-specific cues critically optimize intestinal CD4+ T cell responses, but the exact mechanism the regulate intestinal Th2 responses remain unclear. Basophils, a rare granulocyte, are associated with Th2 function. However, the basophil-dependent signals that support intestinal Th2s are incompletely defined. Previously, we located the Notch signaling pathway in basophil activation during Trichuris muris infection, a mouse model of human whipworm. Here, we show that loss of Notch-activation in basophils results in defective parasite clearance and a blunted Th2 response. We found that basophil-intrinsic Notch was not only required for infection-elicited Th2 cytokine responses, but also for maintaining a broader IL-4 production program across a larger population of diverse intestinal CD4+ T cells. Intestinal CD4+ T cell cytokine production was basophil-dependent in vitro and in vivo, but independent of basophil-secreted factors. Our findings highlight an IL-4 autocrine signaling module that mediates intestinal CD4+ T cell fate and function via direct cell-cell interaction with basophils during helminth infection. These data improve our understanding of the tissue-specific mechanisms required for robust Type 2 immune responses and may inform the development of new therapeutic interventions for helminth infection
Wildfire Smoke Action Plan for Children with Asthma
No full textWildfires are increasing in frequency and severity over time, and exposure to wildfire smoke (WFS) has been linked to adverse outcomes children with asthma. Public health agencies urge parents to check the air quality index (AQI) and take action to reduce their child’s exposure to WFS, but this guidance is inconsistently implemented. After gathering input from parents of children with asthma in Washington State, ambulatory pediatric nurses, public health practitioners, environmental scientists, and medical experts, we created the Wildfire Smoke Action Plan (WFS-AP). This tool is intended to help parents prepare for WFS season and act on poor air quality. It is designed to be delivered by nurses in pediatric ambulatory care settings, but can also be applicable in community-based or school settings. English and Spanish versions are included
A Mixed-Method Examination of Multi-Level Contributors to Community Mental Health Provider Burnout
No full textThesis (Master's)--University of Washington, 2025Community mental health providers (CMHPs) face high risk of experiencing burnout – an occupational syndrome characterized by emotional exhaustion, depersonalization and decreased personal accomplishment. CMHP burnout can lead to thwarted evidence-based practice efforts, staff turnover, worse quality care for clients, and poor provider well-being. However, it remains unclear what the full range of factors CMHPs’ perceive to be contributing to their burnout and which CMHPs are at most risk for burnout. Thus, the aim of the current study was to use qualitative and quantitative methods to examine multi-level factors that may contribute to CMHP burnout. Qualtrics surveys were completed by 197 CMHPs across 36 organizations across Washington State participating in a state-funded cognitive behavioral therapy training initiative for common youth mental health disorders. CMHPs reported on a 1-item measure on burnout, provider- and organization-level characteristics, and answered an open-ended question on perceived contributors to burnout. Using thematic analysis, large caseloads, role overload (i.e., excessive responsibilities without sufficient time and resources), and poor provider well-being emerged as the most salient contributors perceived by CMHPs. Furthermore, multilevel random-intercept logistic regression revealed that CMHPs with 1-3 years of clinical experience were most at risk of experiencing burnout compared to CMHPS with other experience levels within their organization. Findings highlight key areas for targeted intervention to address CMHP burnout and suggest that organizations may need to especially support CMHPs with 1-3 years of clinical experience to mitigate burnout
Knowledge-driven Natural Language Understanding
No full textThesis (Ph.D.)--University of Washington, 2025Recent advances in natural language processing (NLP) mainly relied on pre-trained language models (PLMs) that are trained on vast amounts of data. Although these PLMs achieve remarkable success in improving NLP performance over conventional approaches, they still struggle to accurately understand the semantics of the text. Therefore, extra knowledge, especially the dynamically extracted one, is expected to be leveraged to improve the understanding of the models in the text. This thesis proposes a knowledge-driven approach for NLP that improves PLMs. By dynamically integrating external knowledge from multiple sources, the proposed approach enhances model generalization in different scenarios. Specifically, the thesis leverages three types of knowledge, namely, the lexicon knowledge (e.g., n-grams) extracted directly from raw data, syntax knowledge (e.g., dependency parse trees) obtained through existing toolkits, and the pattern knowledge (e.g., vectors) captured during the training process. Several novel architectures are proposed to leverage the knowledge, such as key-value memory networks for incorporating wordhood information, span attention mechanisms with categorical grouping for improved syntactic parsing, and graph convolutional networks to further enrich contextual representations. Extensive experiments on different NLP tasks at various levels demonstrate the effectiveness of the proposed approaches, which outperform strong baselines and existing studies. Overall, this dissertation not only broadens the definition and utilization of knowledge in natural language processing but also lays a solid foundation for future research in multi-modal, cross-domain, and low-resource environments
From Field to Bioreactor: Metagenomic and Physiological Insights into Microbial Nutrient Cycling Across Oxygen Gradients
No full textThesis (Ph.D.)--University of Washington, 2025Microbial communities drive essential nutrient fluxes in diverse ecosystems, and their activity is strongly influenced by oxygen availability, which governs the balance between aerobic respiration and anaerobic metabolisms such as denitrification, sulfate-reduction, fermentation and methanogenesis. This dissertation explores how oxygen gradients shape microbial community structure and function across three systems: a global metagenomic dataset, a freshwater wetland, and twin aerobic and anaerobic chemostat bioreactors. Clustering of thousands of metagenomic functional gene profiles revealed oxygen as a major axis of differentiation, alongside light, with distinct traits such as antibiotic production and archaeal abundance. In the wetland study, microbial communities were structured primarily by soil depth rather than seasonal variation, reflecting the persistent influence of vertical oxygen gradients despite shifts in porewater chemistry and greenhouse gas fluxes. In bioreactors fed with N-acetylglucosamine—a model compound for microbial necromass—both aerobic and anaerobic communities mineralized the substrate, but with divergent metabolic byproducts and community trajectories. The aerobic system exhibited strong coupling of carbon and nitrogen cycles, including nitrification and denitrification, while the anaerobic system became increasingly methanogenic and resilient to oxygen perturbations. Metagenomic and transcriptomic analyses revealed distinct pathways of compound utilization between treatments. Overall, this work integrates field data, laboratory experiments, and bioinformatics to deepen our understanding of how oxygen availability governs microbial community dynamics and ecosystem-scale biogeochemical processes
Community Perspectives on a Community-Based Contingency Management Program for Quinault Indian Nation Adolescents and Young Adults
No full textThesis (Master's)--University of Washington, 2025American Indian/Alaska Native (AI/AN) communities are disproportionately impacted by harms from substance use and mental illness. Contingency management (CM) reduces substance use by providing positive reinforcement to reward abstinence. We partnered with the Quinault Indian Nation (QIN) to explore perspectives on a culturally adapted community-based CM program for adolescents and young adults (AYA) that provides positive reinforcement to reward engagement in cultural activities that build cultural connection. This study was guided by community-based participatory principles and a community advisory board (CAB) of QIN members. We conducted 15 semi-structured, 30–60-minute interviews with QIN community members. Interviews asked about community connection and community needs and preferences for a culturally adapted contingency management program. Interview transcripts were double coded by three qualitative researchers and analyzed using a combination of Rapid Assessment Process and thematic analysis. Our sample included 6 AYA and 9 adults/elders from the QIN community. Five themes emerged: 1) community connection involves reflecting community values in daily life, 2) QIN AYA have fewer formal and informal pathways to learn cultural practices and traditions, 3) QIN AYA frequently face logistical and/or structural barriers when trying to access cultural activities, 4) shyness, isolation, and competing interests may also hinder QIN AYA engagement in cultural activities, and 5) new approaches to fostering cultural connection are needed to promote health and wellbeing. QIN community members reported AYA face significant barriers to engaging in cultural activities that build cultural connection. While contingency management offers a possible framework to increase community and cultural connection, community member perspectives focused more broadly on upstream factors that may prevent substance use and mental health problems in the future
Automation and Autonomous Experimentation for Sol-Gel Nanomaterial Synthesis
No full textThesis (Ph.D.)--University of Washington, 2025The nexus of laboratory automation and machine learning enables a new paradigm of autonomousexperimental materials research. Autonomous experimentation integrates highly automated
materials synthesis and characterization experiments with machine-learning guided experimental
design strategies to adaptively execute experiments that advance specific research goals. These
systems have the potential to accelerate materials development timelines compared to traditional
manual processes by efficiently targeting experimental efforts. Sol-gel processes are used to
synthesize a diverse array of metal oxide nanomaterials for many applications. In particular,
mesoporous colloidal silicas are promising materials for use as catalysis support matrices,
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chromatographic separation media, and drug delivery systems. Achieving retrosynthetic control
over particle morphologies is critical for advancing use in these applications. In this work,
automated and autonomous systems for the synthesis and optimization of colloidal silicas are
developed. An open-source platform for flexible laboratory automation is developed to enable
democratized access to autonomous experimentation. A system for the fully automated synthesis
and characterization of colloidal mesoporous silicas is developed which integrates the open-
hardware automation platform to perform automated sol-gel synthesis with synchrotron and
laboratory X-ray scattering instruments for characterization. Synthesis campaigns executed with
this system have produced colloidal silicas with a range of particle morphologies and mesopore
phase structures. Finally, progress towards integrating a Bayesian optimization based experimental
design strategy to optimize the morphology of silica nanoparticles is discussed. This work
represents an important step towards accelerating the development of sol-gel materials with
autonomous experimentation
INFRUCTESCENCE
No full textThesis (Master's)--University of Washington, 2025INFRUCTESCENCE is a multimedia sculptural thesis that weaves personal memory, mythic narrative, and material poetics into an exploration of hunger—bodily, emotional, ancestral, and cosmic. Rooted in Knox’s rural Tennessee upbringing, the work spirals outward from the intimate image of a slug inside a green bell pepper into a larger meditation on containment, desire, and transformation. Slugs and shadows recur as symbolic agents of vulnerability and boundary, echoing themes of metamorphosis and mythic punishment. Sculptural forms become vessels of narrative, protected and imprisoned by salt, a material both preservative and destructive.Blending ceramic sculpture, text, and performance, INFRUCTESCENCE imagines a descent into an otherworldly realm where characters like Hades, Eve, and a many-eyed slug navigate a maze of hunger, memory, and myth. Through these figures and their encounters—comical, tragic, surreal—the installation investigates the limits of the body and the self, and the moments in which transformation becomes inevitable. Salt maps the psychic terrain between protection and isolation. Ceramic forms stand as guardians, remnants, and containers for unseen forces.
Drawing from the botanical term infructescence—a cluster of fruits where once flowers bloomed—the work proposes that what remains after longing, trauma, or desire is not absence, but residue: thick with memory, ripe with story. At its core, INFRUCTSECENCE is a sculptural poem about the hunger that shapes us, the boundaries that break around us, and the mythic echoes that carry us home