Clark Honors College Theses
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The thesis is the capstone of a student's academic program at the Clark Honors College. It is an opportunity for each CHC student to build on the education received in both CHC and the academic major to design an independent and original research project. It is the product of the student's original research or creative endeavor and, like graduate theses, must place the research or creative work in the context of prior research or artistic traditions, explain the techniques used to perform the research or develop the creative work, and present and elaborate on the results. Like graduate students, CHC students work closely with faculty members to develop and write their theses and, like graduate students, defend their theses in oral presentations to their thesis committees. There is a fundamental difference between graduate theses and CHC theses; the CHC thesis must be readable by a lay audience, while graduate theses may be written in technical or discipline-specific language.
Beginning in Winter 2005, Clark Honors College students have been notified of the option of submitting their theses to Scholars' Bank and many have done so. Some older theses are also available.
Paper copies of all theses are available in the Robert D. Clark Library on the third floor of Chapman Hall, on the University of Oregon campus. Contact the College for more information: https://honors.uoregon.edu/.
Paper copies of all theses are also available in the University Archives operated by the University of Oregon Libraries. To search the Libraries' catalog, visit the web site at: https://library.uoregon.edu/.
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Item Metadata only Characterizing Cortical Visual Responses Near the Perceptual Threshold(University of Oregon, 2022) Weibezahn, Annie; Niell, Cristopher; Chauvin, Kristen; ,At any given moment, our brain is processing a large amount of sensory information, yet we are only consciously aware of a small portion of it. Information that we perceive must reach a perceptual threshold, which is defined as the point at which a subject can consciously recognize a presented stimulus 50% of the time. However, perceptual thresholds are not static - they vary from day to day and over the course of experimental tasks. Previous research at the single-cell level has suggested that our sensory perception strongly depends on the brain’s internal dynamics, often referred to as behavioral state, which changes based on factors like locomotion, arousal, and attention. Yet, whether behavioral states can account for fluctuations within perceptual thresholds is not known. The goal of my project was to characterize the dynamic range of population level neural responses to visual stimuli that varied in contrast and duration. Using wide field calcium imaging of transgenic mice, I identified maximum and minimum neural responses, quantified the population-level neural threshold, compared these values across cortical visual areas, and identified stimulus parameter values that likely lie near the perceptual threshold. In future work, pupil diameter and running speed will be tracked alongside neural activity in response to the near-threshold stimulus parameters I identified to further our understanding of how behavioral state influences conscious awareness.Item Open Access Community, Identity, News: Engaged Journalism for the Social Native(University of Oregon, 2023) Hutcherson, Ella; Lawrence, "Regina "; Dudukovic, Nicole; ,This thesis explores how engaged, or community-centered, journalism might best meet the needs of social natives, or people currently ages 18-24, who have different and more hyper-personalized engagement patterns than their generational predecessors. This is done in part in the form of a feature-length journalistic article supplemented by a focus group with students at the University of Oregon, with the intention of demonstrating how journalists can engage with a community in order to produce a work of journalism that is inclusive and reflective of those they seek to represent. Through discussing with these students topics of community and identity, what news means to them, and potential solutions, it is clear that these particular social natives seek a news landscape with more hopeful coverage, diversity in newsrooms and topics covered, and appreciation and respect demonstrated for all communities being reported on.Item Open Access Constructing Belonging: An In-Depth Analysis of the Oregon Sanctuary Movement(University of Oregon, 2022) Han, Alexis; Yarris, Kristin; ,; ,By conceptualizing Oregon’s history of immigrants’ rights activism as the Oregon sanctuary movement, this research project takes an interdisciplinary lens to analyze historic and modern expressions of sanctuary as a means of supporting undocumented immigrants in Oregon. By focusing on activism and public policy as enactments of sanctuary, I answered these research questions: How has the Oregon sanctuary movement evolved from its origins in faith-based activism? And how does Oregon’s sanctuary policy and the work of sanctuary and immigrants’ rights activists intersect to cultivate belonging for undocumented people? I engaged in a multi-method study by analyzing interviews with Oregon sanctuary activists, conducting interviews with immigrants’ rights professionals, and analyzing the legislative process of the Sanctuary Promise Act. While the Oregon sanctuary movement remains consistent in its origins in faith-based and political activism, my research indicates the resiliency and adaptability of the Oregon sanctuary movement as a community-powered campaign that evolves and expands to respond to the needs of undocumented Oregonians and cultivate belonging for all Oregonians.Item Open Access Design and Cytocompatibility of Hyaluronic Acid Hydrogels for Bone Regeneration(University of Oregon, 2022) Johnson, Ireland; Hettiaratchi, Marian; Spaulding, Veronica; ,Large bone defects and fractures caused by trauma or disease remain a serious challenge for orthopedic surgeons, and there is a need for more effective treatment strategies to repair injured bone. Bone autografts, a tissue graft from the same patient, are the ideal treatment strategy because there is a low chance of host rejection, and the graft is not weakened from sterilization. However, bone autografts are not widely available, and their harvest can cause donor site morbidity. As an alternative strategy, biomaterials composed of the natural polymer hyaluronic acid (HA) can be used to deliver osteogenic (bone-forming) proteins that repair injured bone. The objective of this study was to develop and test the biocompatibility of HA-based hydrogels for protein delivery for bone regeneration applications. HA hydrogels were formed by dynamic, covalent bonds between aldehyde functional groups on oxidized HA and HA functionalized with adipic acid hydrazide or carbohydrazide groups. Hydrogels were seeded with 3T3 fibroblast cells expressing green fluorescent protein to evaluate cell compatibility. Live and dead cells were evaluated using green fluorescence from GFP and red fluorescence from ethidium homodimer, respectively. A combination of HA separately modified with oxidized and carbohydrazide HA, each at 2.5% (w/v), maintained high cell viability (>82.3% for all time points) and encouraged a rate of cell growth that surpassed all other conditions. This project also investigates the cytocompatibility of the HA hydrogels with skeletal myoblasts. Future work will aim to further functionalize and optimize the HA hydrogels themselves as a protein delivery vehicle for osteogenic proteins like BMP-2. The impact of this project will facilitate the future use of HA hydrogels as a biomaterial that rivals the healing response of bone autografts.Item Open Access Evaluating the Extent and Sources of Zinc Contamination Within Eugene-Springfield Waterways(University of Oregon, 2022) Klein, Charlotte; Polizzotto, Matthew; ,; ,Stormwater runoff from urban and suburban areas carries pollutants, adversely affecting water quality in local waterways. In the Eugene-Springfield metro area, a specific stormwater pollutant of concern is zinc- a known herbicide, antimicrobial, and toxin at certain concentrations for aquatic organisms. Notably, zinc has been rising in water quality measurements in Eugene over the past 20 years. Using 2019 as a case study year, data aggregation revealed similar zinc concentration patterns within the waterways of Springfield and Eugene. Potential sources of zinc contamination are numerous, but findings in this study indicated the greatest proportion of zinc pollution is likely from moss control products, vehicular tire- and brake-wear, and industrial discharges. Spatial modeling of these potential sources of zinc contamination revealed stormwater basins with high zinc pollutant severity potentials, in turn distinguishing areas for future stormwater sampling efforts. This work adds to the understanding of municipal stormwater pollution in the Pacific Northwest and can lead to informed strategies for source control, minimizing zinc loading to the environment.Item Open Access Exploring Grasshopper Feeding Preferences Based on Plant Carbon to Nitrogen Ratios Across Different Nutrient Treatments(University of Oregon, 2022) Forsman, Sofi; Hallett, Lauren; ,; ,Anthropogenic nutrient enrichment can rapidly change ecosystem functions and diversity, as well as plant tissue composition. This research explores the impacts of soil nutrient enrichment on insect-plant relationships in a rare montane meadow ecosystem in the Western Cascades of Oregon. Montane meadows host a wide variety of diversity. We performed an experimental study at Bunchgrass Ridge, a Long-Term Ecological Research site supporting a long-term nutrient loading experiment. Grasshopper feeding was quantified by observing leaf damage and analyzing leaf tissue chemistry of two plant species, grass B. carinatus and legume L. oreganus. Leaves for each species were collected and their C:N ratios were analyzed. Our analyses show that soil nutrient enrichment, plant tissue C:N, and plant species do impact grasshoppers’ feeding preferences, with plant species having the largest impact. Understanding the ecological drivers that affect threatened montane ecosystems can inform management and policy decisions as we face continuous anthropogenic influences.Item Open Access Fitness Effects of Somatic Mutations on Mimulus aurantiacus Progeny(University of Oregon, 2022) McLean, Jack; Streisfeld, Matthew; ,; ,Unlike animals, plants possess the unique ability to pass on mutations to progeny that arise both through meiotic (germline) and mitotic (somatic) division. In spite of these two sources of genetic variation, mutation rates per generation appear to be similar between plants and animals. One explanation for this discrepancy is cell lineage selection (CLS), which claims that cell lineages with deleterious somatic mutations are sieved out of the population of cells in a plant’s shoot apical meristem through natural selection. On the other hand, beneficial mutations may become fixed within the population. To investigate the plausibility of CLS, I performed multiple experiments to determine the fitness effects of somatic mutations by comparing the progeny of Mimulus aurantiacus plants generated via self-pollination made within the same flower (autogamy) to progeny from self-pollinations made between stems on the same plant (geitonogamy). Importantly, autogamy leads to homozygosity of a proportion of somatic mutations, but progeny from geitonogamy remain heterozygous for mutations unique to each stem. Significant differences in fitness were observed among some autogamous and geitonogamous progeny. Surprisingly, autogamous progeny from several genets displayed significantly increased fitness, which challenges the assumption that differences in fitness between autogamous and geitonogamous progeny are caused solely by deleterious mutations. These results support the hypothesis that somatic mutation accumulation during vegetative growth can result in non-negligible—and possibly beneficial—changes in fitness among progeny due to CLS.Item Open Access Geometric and thermal constraints on the timing of Alaskan tidewater glacier retreat(University of Oregon, 2022) Waghorn, Lucy; Sutherland, Dave; Hager, Alex; ,Glaciers around the world are retreating at increasing rates, prompting concerns over sea level rise and the future of the cryosphere. In southern Alaska, some have retreated while their neighbors have advanced, indicating that local atmospheric conditions are not the only influence on glacier retreat. One possible factor is the interaction of ocean water with the glacier at the terminus. However, fjord geometry can alter the ocean water that interacts with the terminus, and the interaction of fjord geometry and ocean temperature anomalies has not been investigated in Alaska thus far. To investigate the interaction of fjord geometry and glacier retreat, we used bathymetry, air temperature (AT), sea surface temperature (SST), and terminus position data. Here we show that high SST anomalies may enhance glacial retreat in fjords with shallow sills. During a high SST anomaly, some glaciers in shallow-silled fjords retreated rapidly from a point of relative stability. It is possible that shallow sills influence fjord water circulation where only the warmest part of the water column can enter the near terminus region, potentially leading to enhanced glacier retreat after high SST anomalies. Many glaciers also showed enhanced retreat in the two years after a high AT anomaly. Though other factors can also contribute, understanding the processes and interactions that lead to glacier retreat is becoming increasingly important as climate change alters the atmosphere and environment.Item Open Access Investigating Graywater Filtration Efficacy of Pacific Northwest Pumice and Scoria(University of Oregon, 2022) Price, Margery; Giachetti, Thomas; ,; ,Graywater is non-sewage wastewater from washing machines, bathing, and cleaning. It can be recycled if particles of shampoo, soap, and other contaminants can be removed, usually by filtration through a medium such as gravel or sand. Such graywater recycling methods are becoming increasingly important as water crises worsen worldwide and fresh water becomes scarcer. This project aims at testing the potential of pumice and scoria (porous volcanic rocks) from Oregon volcanoes as efficient filters for graywater recycling. After characterizing the physical properties of the rock samples (size, shape, porosity), we carried out week-long experiments in which graywater interacts with different size fractions of the two types of rock to identify the best graywater filter. We find that, among the samples tested, 1-2-mm pumice particles are the most effective filtration media amongst those tested. Immersion of graywater in these samples results in the neutralization of the graywater pH to a value of 6.8 and a >75% decrease in turbidity after seven days. The interaction of the rock particles with the graywater also leads to an increase in Total Dissolved Solids (TDS). More work needs to be done analyzing the complex chemical and physical interactions between the rocks and the graywater.Item Open Access Like Mother, Like Child: Intergenerational Transmission of Maternal Emotion Regulation to Six-Month Infants(University of Oregon, 2022) Elliot, Annaliese; Ablow, Jennifer; Measelle, Jeffrey; ,Previous research demonstrates how maternal psychopathology is associated with negative infant outcomes; however, there is minimal research on intergenerational transmission. Specifically, there is a lack of literature on intergenerational transmission of emotion dysregulation. Emotion dysregulation has been demonstrated as a precursor to future psychopathology in childhood and adulthood; therefore, infancy is a crucial time period to develop self-regulatory skills. This study aims to build upon previous research to further understand how maternal emotion dysregulation predicts poor infant regulation. This study examines the predictive association among maternal emotional dysregulation reported prenatally during the third trimester and postnatally at six months, using the Difficulties in Emotion Regulation Scale (DERS), and observations of infant self-regulation postnatally (N = 221). Temperament, measured with the Infant Behavioral Questionnaire (IBQ-R), was controlled to capture the independent contributions of maternal dysregulation to infant’s early indices of emotion regulatory capacities. Infants’ self-regulation and negative affect was measured at 6 months postpartum with micro-analytic behavioral coding during the Still Face Paradigm (SFP), a widely used paradigm to examine early relationship patterns between caregivers and their infants. Although association between prenatal reports of maternal emotion regulation was not significantly related to infants’ emerging regulatory capacities, maternal reports of concurrent dysregulation at 6-months postpartum was associated with poorer self-regulation in their infants. This finding suggests that emotion dysregulation can be transmitted across generations by postpartum mother-child interaction influences.Item Open Access Macrophagous Carnivory by Ciliated Larvae: Development and Feeding of an Unknown Capitella Larva(University of Oregon, 2022) Bergen, Sebastian; von Dassow, George; ,; ,Long-standing tradition in larval biology has been to categorize invertebrate larval developmental strategies into two general modes: lecithotrophic versus planktotrophic development. Lecithotrophic larvae hatch from eggs containing all the nutritive materials required to form a juvenile, while planktotrophic larvae graze on unicellular algae as a requirement for metamorphosis into a juvenile. However, recent work, which includes studies on members of two large taxa of spiralian worms, polyclads and nemerteans, have revealed the widespread presence of larvae who consume animal prey instead of algae. We refer to this developmental mode as macrophagous carnivory. The intent of this thesis is to fully document larval development and prove that a carnivorous diet is required for the maturation of an unknown Capitellidae species found in the waters around Coos Bay. These larvae have a distinctive feeding behavior and morphologically develop on a solely carnivorous diet to settlement competency. These findings contribute to a growing body of evidence for macrophagous carnivory as a widespread larval strategy to extract resources from the plankton. Their developmental changes that occur from collection from plankton to post-settlement have been documented, though their identity was never uncovered, and their eggs and adult forms are current unknown, leaving their lifecycle incomplete.Item Open Access Modeling and Characterizing BMP-2 Protein Binders for Fracture Regeneration(University of Oregon, 2022) Fear, Karly; Hosseinzadeh, Parisa; ,; ,Critically-sized bone defects experience delayed regeneration correlated to deficient protein signaling at the injury site. Delivering the potent growth factor bone morphogenetic protein-2 (BMP-2) to the defect is a promising clinical intervention to augment fracture healing in such cases. The release kinetics of BMP-2 from a hydrogel scaffold play a crucial role in the success of therapeutic delivery in terms of improved healing outcome. For instance, rapid BMP-2 release causes suboptimal bone formation. Affinity interactions between BMP-2 and binder proteins offer a mechanism to fine-tune the spatial placement and timing of exogenous BMP-2 bioactivity over the course of bone healing. Experimental selection techniques may identify such binder proteins from large protein libraries. However, experimental pipelines fail to reveal structural details of the protein-protein interaction and explore only a small subset of the possible sequence landscape for binding proteins. The computational design route is therefore an attractive strategy to rationally engineer a BMP-2 delivery control mechanism. In order to slow BMP-2 release, I first sought to directionally modify experimentally selected binding proteins with computational modeling and mutagenesis. Next, I generated de novo protein binders hypothesized to retain BMP-2 via affinity interactions when conjugated to the hydrogel scaffold. I approached this challenge with well-established computational protein design methodologies to yield binding proteins with target surface site-specificity. I then developed a machine learning model to predict binding affinity for computationally modeled proteins. Finally, I sought to experimentally characterize my designed binders using yeast surface display and flow cytometry to validate in vitro that my computational pipeline generates functional designs, appropriate for controlled BMP-2 delivery.Item Metadata only "PROPORTIONALITY AND MAKING THINGS RIGHT: AN INTEGRATIVE APPROACH TO RETRIBUTIVE AND RESTORATIVE JUSTICE "(University of Oregon, 2023) Linder, Sam; Stern, "Michael "; Bayerl, Corinne; ,"In this project, I aim to integrate principles of retributive justice and restorative justice into a comprehensive philosophy of justice that can punish wrongdoers while still acknowledging and respecting their humanity. Retributive justice aims to punish offenders in proportion to the crime they committed. However, its emphasis on bringing perpetrators to justice through punishment can cause people to forget that the perpetrators are human beings, resulting in punishments that may be too extreme or immoral. The aim of restorative justice is to heal, not just the person who has been harmed by the wrongdoer, but to heal all parties involved. This usually means the victim, the offender, and both of their respective communities. I think each system of justice has its merits, since the retributivist system has been widely used in the U.S., but it would be beneficial to integrate some restorative principles into the current American criminal justice system. In my project, I examine the core beliefs of the retributivist system and their origins, detailing how they came to be what they are today. Next, I cover restorative justice and its benefits. Finally, I outline an integrative approach to both systems of justice, with the hope that it will encourage people to reconsider how they view criminals and those they perceive as “enemies.” "Item Metadata only The Associations Among Nature Exposure, Physical Activity, and Adolescent Stress(University of Oregon, 2023) Landers, Katie; Budd, Elizabeth; ,; ,INTRODUCTION: Stress has adverse health risks, especially during adolescent development, and can lead to depression or death by suicide. The present study examined the associations among nature exposure, physical activity, and adolescent stress. METHODS: A purposive sampling strategy was used for recruitment and 85 participants, 12 to 17 years old, from Lane County, OR during the Summer of 2022 were studied. Participants were involved in Visit One (consent/assent procedures, baseline survey, Actigraph accelerometer fitting, and downloading NatureQuant application), a 7-day participation period (wearing Actigraph accelerometer, regularly carrying a smartphone, and daily surveys completed), and Visit Two (Actigraph accelerometer returned, and gift cards earned for study completion). Mean daily nature exposure (NE) over the week, mean daily moderate to vigorous physical activity (MVPA) over the week, and mean stress score over the week were measured. RESULTS: Nature exposure was not significantly associated with stress and physical activity was not significantly associated with stress. However, nature exposure and physical activity were significantly positively associated (R = 0.349, p = 0.001). DISCUSSION: This study is a novel design with objectively measured independent variables. Further studies are needed to show the associations between NE, MVPA, and stress.Item Open Access The Main Socioeconomic Determinants of Exclusionary Zoning in U.S. Jurisdictions(University of Oregon, 2023) Almajed, Mohamed; Harbaugh, William; ,; ,Exclusionary zoning policies impose restrictions on the development of housing with the intention or effect of excluding certain groups or classes of people. By favoring certain demographics, such policies can disproportionately affect lower income individuals and minorities by restricting their access to affordable housing. This, in turn, exacerbates income segregation and perpetuates racial discrimination, which widens the socioeconomic gap between affluent and disadvantaged communities. This paper examines the main socioeconomic determinants of exclusionary zoning in American Jurisdictions. Using a comprehensive dataset that combines socioeconomic variables with specific regulation indexes that are intended to proxy for exclusionary zoning, this research employs multiple regression analysis to examine the main predictors of regulatory restrictiveness. The findings indicate that income, race, age, and poverty levels, all play an important role in determining the regulatory restrictiveness of U.S. jurisdictions. Specifically, the results suggest that older and wealthier areas tend to implement stricter regulations to preserve property values, while poorer areas with a higher proportion of people working in manufacturing exhibit lighter regulatory controls. The results also reveal that regulatory restrictiveness decreases in areas with a higher proportion of white residents. The discussion addresses the limitations of this study and emphasizes the need for further research to better understand the complex dynamics between socioeconomic factors and exclusionary zoning.