Graduate Theses and Dissertations

Permanent URI for this collectionhttps://hdl.handle.net/10877/135

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    Texas Tuition Deregulation, At What Cost? Impact of General Academic Institution Costs on Community College Enrollment
    (2009-05) Goerdel, Jenny Rae; Yun, Hyun Jung; Tajalli, Hassan; Stouffer, William B.
    No abstract prepared.
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    The Value of the Bookmobile, With Special Reference to Bexar County
    (1940-08) Bell, E. Carroll; Rogers, J. L.; Elliott, Claude; Grusendorf, A. A.
    No abstract prepared.
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    The Design and Implementation of a Two Pass Assembler
    (1976-08) Murphy, Jack; Early, Grady G.; Poirot, James L.; McEwen, Henry N.
    No abstract prepared.
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    Nuestra Historia: A Multi-Sited Critical Ethnography
    (2023-05) Cantu, Mark; Guajardo, Miguel; Arar, Khalid; Martinez, Melissa; Koschoreck, James (Jim); Grijalva, Benjamin
    This qualitative dissertation builds on my experiences, especially over the past 23 years as a student, teacher, campus leader, and district leader. The research is grounded in the Community Learning Exchange (CLE) worldview (M. A. Guajardo et al., 2016). I reference other scholars who believe in school and community reform for the greater good of our society. Through a multi-sited critical ethnography, I used storytelling and story making to shed light into three innovative spaces. The purpose of this research was to reimagine leadership development and school experiences that are hegemonic and do not serve Mexican American leaders, teachers, and students well. Change is necessary as more students of color fill our schools and greater communities. Through a series of pláticas, my research partners and I engage in critical reflection using guiding questions to come to an understanding of our lived experiences in one of the three innovative spaces highlighted in the dissertation. The findings and recommendations are connected to the ecologies of knowing and the axioms of the CLE (M. A. Guajardo et al., 2016).
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    Mitigating the Effects of Label Noise in Time-Series Sensor Data
    (2023-05) Atkinson, Gentry M.; Metsis, Vangelis; Zong, Ziliang; Gao, Byron; Athitsos, Vassilis
    Uncertainty in training datasets can negatively affect the ability of machine-learning models to learn solutions to real-world problems. Label noise, defined as inaccurate annotations, is one particularly detrimental uncertainty. This issue is more pronounced in time series data, where interpretability is inherently limited. A variety of real-world applications, such as medical diagnostics, human activity recognition, weather forecasting, and emotion recognition, depend on data obtained from one or more sensors. Consequently, the development of enhanced methodologies for identifying and relabeling inaccurately labeled instances in sensor datasets is of paramount importance across various domains. This dissertation presents a comprehensive set of approaches to improve the usability of incorrectly labeled datasets: detecting incorrect labels, correcting labels, and generating new instances of data from noisy examples. We demonstrate that self-supervised deep feature extraction can effectively learn representations of time series data, irrespective of the uncertainties caused by incorrect labels. These deep features are then employed in conjunction with a novel adaptation of the k-nearest neighbors (KNN) algorithm, as well as an estimated label transition matrix, to relabel data instances with a high degree of precision. Finally, this research introduces an innovative adaptation of generative diffusion for the generation of new data instances derived from examples with noisy labels. This data generation method is shown to adhere more closely to the distribution of the example data compared to existing techniques. The proposed approaches hold significant potential to improve the performance and reliability of machine learning models in various fields that rely on sensor data.
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    Slow Breathing Reduces Biomarkers of Stress in Response to a Virtual-Reality Active Shooter Training Drill
    (2023-05) Dillard, Courtney; McAllister, Matthew; Martaindale, M. Hunter; Hunter, Stacy D.
    Tactical occupations (i.e., military, law enforcement personnel) regularly encounter lifethreatening situations while on duty. Acute participation in virtual reality active shooter scenarios has been shown to increase markers of stress. Although tactical occupations are trained to utilize slow breathing during high stress scenarios, there is no evidence supporting the effectiveness of slow breathing in relation to a virtual reality-active shooter training drill ( VR-ASD). The purpose of the study is to determine the impact of acute slow deep breathing on markers of stress in response to a virtual reality active shooter drill. METHODS: A parallel between subjects design was used, during which, eighty-one (n=81) subjects performed 5 min of either slow breathing method 1 (SB1), slow breathing method 2 (SB2), or normal breathing (NB) immediately pre and post VR-ASD. Salivary samples, heart rate, and state-anxiety inventory were collected 30 min pre, 5 min pre, 5 min post, and 30 min post VR-ASD. Saliva was analyzed for stress markers: α-amylase (sAA) and secretory immunoglobulin-A (Sig-A). sAA and SIgA were analyzed via 3x4 (treatment x timepoint) factorial ANOVAs. HR and SAI were analyzed via 2x4 factorial ANOVA. RESULTS: Both methods of slow breathing resulted in significantly lower sAA concentrations at 5 (p < 0.001), and 30 min post VR-ASD (SB1: p= 0.008; SB2: p < 0.001) compared to NB. In the NB condition, sAA concentrations were significantly elevated 5 min post VR-ASD (p < 0.001) compared to all other timepoints but did not change across time in SB1 or SB2 (p > .05). A significant increase in SIgA concentrations was noted 5 min post VRASD compared to all the other time points (p < 0.001). CONCLUSION: The VR-ASD resulted in a significant increase in stress markers sAA and SIgA. Both SB1 and SB2 prevented a significant increase in sAA concentrations and resulted in lower concentrations post VR-ASD. Future studies should investigate the effects of longitudinal participation in slow breathing.
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    Go With the Flow: Impacts of High and Low Flow Conditions on Freshwater Mussel Assemblages and Distribution
    (2023-05) Cushway, Kiara C.; Schwalb, Astrid; Schwartz, Benjamin; Piercy, Candice
    Freshwater mussels are a highly imperiled fauna with a broad diversity in North America. Due to their imperilment, understanding how climate change and natural and anthropogenic flow conditions impact mussels is an important aspect of creating sustainable and effective management and conservation goals. The goal of this study was to understand how high and low flow conditions (i.e., flooding and drought) impact freshwater mussel distribution in a stream in central Texas. This region is facing mounting concerns regarding water scarcity and altered hydrologic regime. Specifically, I sought to understand 1) the capacity of perennial or intermittent pools with various habitat conditions to serve as ecological refuges for freshwater mussels during drought, and 2) the role of hydraulic variables like shear stress, Froude number, stream power, and depth in influencing the composition and distribution of freshwater mussel assemblages during variable flow conditions. For objective one, field surveys in an intermittent segment of the San Saba River in central Texas during 2021 and 2022 indicated that perennial pools with characteristics that buffer the influence of emersion and thermal stress may serve as important refuges for freshwater mussels during drought and drying conditions. However, the low abundances of mussels in this segment may provide a bleak glimpse into the future as climate change and human water usage exacerbate drought conditions in streams in drier regions. For objective two, hydraulic conditions in a 20 km segment of the upper San Saba River were estimated using a 2D HEC-RAS model. Low flow (0.7x median daily flow) and moderate to extreme flood conditions (10 to 50 % exceedance probability) successfully predicted mussel presence across 200 sites between 67 and 79 % of the time using Random Forest modeling. In addition, hotspots of freshwater mussel richness and diversity were observed in flow refuges with lower shear stress, stream power, and Froude number. Species-specific responses to hydraulic conditions also showed that different mussel species are disparately constrained by hydraulic conditions. This is the first study that systematically examined ecological refuges for freshwater mussels during drought, and by combining a hydraulic model with extensive survey data, this study also provides valuable insights into the association of mussel distribution and hydrodynamic conditions in flashflood and drought-prone streams.
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    A Broader View of Conservation: Mapping Nature and Culture in Gillespie County, Texas
    (2023-05) Weathersby, Joanna; Julian, Jason; Sansom, Andrew; Currit, Nathan
    Working landscapes are cultural landscapes with natural value that provide tangible and intangible benefits to people. The development of working landscapes and other rural lands has been increasing, especially in regions experiencing rapid urban growth. Ensuring the future of working landscape benefits is especially challenging where private ownership is dominant. Available conservation options (e.g., conservation easements, cultural designations) rely on the preference of private landowners that also face a heightened incentive to subdivide or sell. To advance the conservation of working landscapes, this research developed a spatial inventory of broad landscape benefits (ecosystem services) beginning with a case study at a private ranch. The inventory was then adapted and expanded at the county level where benefits from cultural, regulating, and provisioning categories were mapped from publicly accessible sociocultural and environmental data repositories. Based on categorical and spatial variation in the mapped benefits inventory, four conservation targets zones were identified and framed within the context of conservation planning and tradeoff analyses.
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    An Original Play: When the Goldfish Dies
    (1976-08) Cotton, Jerry D.
    No abstract prepared.
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    The Women that Jack Built: A Study of the Women Characters in C.S. Lewis' Space Trilogy
    (1988-11) Cottle, Linda; Parkin-Speer, Diane; Heaberlin, Dickie; Wright, Loyd
    No abstract prepared.
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    James Byrnes: State Department Diplomacy on the German Question, 1945-1946
    (1975-08) Costello, Susanna Moeller; Brunson, Bill; Brasher, Thomas L.; Josserand, Frank B.
    No abstract prepared.
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    The Prevention and Treatment of Athletic Injuries Incurred by Junior High School and Senior High School Boys
    (1950-08) Corner, John H.; Crosslin, Hiawatha; Wiley, E.O.; Rogers, J. Lloyd
    No abstract prepared.
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    An Analysis of Six Critical Presidents and Their Effects on Their Successors
    (1990-07) Costas, Julie Windrum
    No abstract prepared.
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    Administering a Program of Pupil Activities in Chilton High School
    (1951-08) Cornelius, R. Wayne
    No abstract prepared.
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    Reproductive Biology and Leaf Structure of Abronia Macrocarpa Galloway (Nyctaginaceae), an Endangered East Texas Endemic
    (1991-12) Corlies, Gena Kaye; Williamson, Paula S.; Schneider, Edward L.; Fitzsimons, Dennis E.
    Abronia macrocarpa, large fruited sand verbena, is classified as an endangered species. Distribution is restricted to three counties in eastern Texas. The species grows as a perennial throughout its range. Established plants and seedlings develop a basal rosette in the Fall and over-winter. Anthesis typically begins in March or April and is completed by May. Anthesis occasionally occurs in the Fall following periods of high precipitation. The flowers exhibit characteristics of a moth pollinated species. Since fruits did not develop in the greenhouse unless flowers were hand pollinated, there is probably no self pollination. Average pollen viability is 91.6%. Average fruit set is 62%, and seed viability is low (27%). Leaves are ovate to elliptic with entire margins. The epidermis is covered with glandular trichomes and anomocytic stomata. There are more stomata within the upper epidermal layer than the lower epidermal layer. The mesophyll is differentiated with an abundance of substomatal chambers in the palisade layer. Bundles of raphide crystals occur within idioblastic cells distributed throughout the blade and petiole.
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    Internet Voting: Reinventing Participatory Government
    (2000-05) Corley, Stephen L.; Opheim, Cynthia; Weinberger, George; DeSoto, William
    No abstract prepared.
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    Seedling Recruitment and Plant Recolonization of a Disturbed Population of Abronia Macrocarpa Galloway (Nyctaginaceae)
    (1996-05) Couch, Karen Louise; Williamson, Paula S.; Lemke, David E.; Koehn, Robert D.; Perry, Reeves B.
    No abstract prepared.
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    Mirror Imagery in Selected Novels of Doris Lessing
    (1980-08) Cotton, Jo Ann Line
    No abstract prepared.
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    Bacteriophage T4 Replication in an Aquatic Biofilm
    (2000-05) Corbin, Brian D.; Aron, Gary M.; McLean, Robert J.C.; Garcia, Dana M.
    No abstract prepared.
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    The Personal is Theoretical: Bell Hooks' Personal Narrative Approach to Contemporary Feminist Theory
    (1995-05) Coppoletta, Lisa Marie; Mandziuk, Roseann M.; Burkholder, Thomas R.; McKinney, Audrey
    No abstract prepared.