Digital Commons Network^™

The Impact Of Nutrition On Insecticide Resistance And Gene Expression In Aedes Aegypti, Esmeralda Guadalupe Rosas

Theses and Dissertations

The development of insecticide resistance in Aedes aegypti, a major vector of dengue and Zika viruses, threatens vector control efforts, particularly in endemic regions such as South Texas. Insecticides remain widely used; however, their overuse has accelerated metabolic resistance mediated by cytochrome P450 enzymes. Environmental factors such as larval nutrition may influence mosquito physiology and resistance-associated gene expression, yet this relationship remains poorly understood. This study examines how larval nutritional conditions affect the expression of cytochrome P450 genes linked to pyrethroid resistance in Aedes aegypti. Larvae were reared under five dietary treatments differing in lipid and protein ratios, and adults …

The Role Of Operational Context In Shaping Energy Management Portfolios: A Comparative Case Study Of Two Manufacturing Facilities, Cynthia Aranda

Theses and Dissertations

Using two facilities as illustrative examples, this research investigates how a manufacturing plant's operational and financial context may influence its investment decisions in energy-efficiency measures. This challenges the primacy of the simple payback period (SPP) as a screening tool and instead demonstrates the role of operational context in investment decision-making. To this extent, this study is anchored to a qualitative comparative case study analysis of two ITAC energy assessments for two manufacturing plants in Texas: a higher value-added aerospace MRO plant (GE Aerospace, TR0060) versus a cost-sensitive automotive stamping plant (UMP Metal Stamping, TR0061). The two cases illustrate two different …

Spatiotemporal Evolution Of Flow Decline And Water Consumption In A Highly Regulated Transboundary River: The Lower Rio Grande/Bravo, Ana Yarely Casillas Rodriguez

Theses and Dissertations

Long-term flow variability in transboundary rivers reflects the combined influence of water availability, infrastructure development, and binational water use. Integrating historical discharge with evolving water-use data remains challenging due to fragmented records and nationally bounded assessments. This study reconstructs a 125-year discharge record (1900–2025) from historical Water Bulletins and modern observations at 12 gauging stations, providing a spatiotemporal assessment of flow evolution and water-budget components in the Lower Rio Grande/Bravo (LRG).

Discharge records were grouped into four hydrologic regimes—natural (1900–1913), pre-dam (1935–1950), post-dam (1974–1989), and modern (2010–2025)—and analyzed alongside binational water-use data across major sectors. A basin-scale water budget, using …

Probing The Dynamic Behavior Of The Androgen Receptor In The Presence Of Heptyl And Methyl Parabens, Edgardo De Leon

Theses and Dissertations

The androgen receptor (AR) mediates physiological signaling from endogenous androgens, a function that can be disrupted by endocrine disruptors with serious reproductive and developmental consequences. Parabens, widely used preservatives, inhibit AR signaling in cell-based assays, with inhibitory potency correlating with alkyl chain length: heptylparaben exhibits stronger antagonism than methylparaben, which shows no effect. We hypothesize this differential potency arises from allosteric modulation at the AR Binding Function 3 (BF-3) site, altering dihydrotestosterone (DHT) binding dynamics. Docking calculations using antagonist-bound AR crystal structures, followed by molecular dynamics simulations, show that methylparaben fails to remain bound at BF-3, whereas heptylparaben maintains stable …

A Testimoniando On Tutoring Practices In A Predominantly Latine Writing Center: How Drawing From Tutors’ Memories Fosters Reflective Practices, Emily Michelle Rodriguez

Theses and Dissertations

The student body of the University of Texas Rio Grande Valley (UTRGV) consists primarily of Latine students, a population that is reflected in the Writing Center’s tutor demographics. Tutor practices connect to the training sessions that are based on disciplinary expectations but also incorporate each tutor’s epistemology, cultural beliefs, and lived knowledge experiences. To reflect on the practices, memories, and experiences that tutors collected at the Writing Center, the concepts of testimoniando and testimonios will serve as the praxis and means of sharing the experiences and lived knowledge of tutors who identify as part of a marginalized group; this allow …

Morphological Evolution And Sediment Budget Of A Flood-Tidal Delta On The Rio Grande Delta Plain: Bahia Grande, Texas, Usa, Aleen Pertuz Paz

Theses and Dissertations

The Isabel Delta is a recently formed flood-tidal delta within the restored Bahia Grande system on the Rio Grande Delta Plain, Texas, USA, where renewed tidal connectivity has created conditions for rapid sediment buildup and landform evolution. This study quantified morphological changes from 2008 to 2025 using satellite imagery. It assessed sediment retention by comparing the effective sediment discharge required to reproduce observed delta growth with field-based estimates of sediment supply derived from channel hydrodynamics, cross-sectional area, and suspended sediment concentration. The delta expanded steadily throughout the study period, with increases in bar, channel, and total surface area, and an …

Identification Of Peptides For A Muc13 Cancer Vaccine, Abigail Olivia Gomez

Theses and Dissertations

Mucin 13 (MUC13) is a transmembrane glycoprotein that is frequently overexpressed in epithelial cancers. Its extracellular domains and cytoplasmic signaling potential contribute to disrupted cell adhesion, increased invasion, and cancer-promoting pathways, making MUC13 a promising target for immunotherapy. This project used an in-silico approach to identify MUC13-derived peptides predicted to bind HLA class I molecules and support CD8+ T cell-mediated immune responses. Bioinformatics tools were used to screen candidate epitopes for HLA binding affinity, antigenicity, toxicity, IFN-γ-inducing potential, and population coverage, allowing rational prioritization of peptide candidates for experimentation. Selected peptides were evaluated in THP-1-derived macrophages using RT-PCR, Western blotting, …

Teaching At The Ai Crossroads: Educators’ Experiences, Ethics, And Practice In Pharmacy Education, Crystal Marie Zuniga

Theses and Dissertations

Artificial intelligence (AI), including emerging generative AI tools, is increasingly influencing healthcare workflows and reshaping expectations for workforce preparation. Pharmacy technician education must respond to these shifts while maintaining academic rigor and prioritizing patient safety, ethical practice, and professional accountability. This qualitative study examined pharmacy educators' perspectives on the integration of AI within the Pharmacy Technician Program at Southern Valley College, with attention to how educators interpret AI’s relevance, risks, and instructional implications in pharmacy education.

Data collection included one focus group and individual semi-structured interviews with four pharmacy educators with diverse professional experiences in pharmacy practice and education. Data …

Sub-Ghz Propagation Along Freight Trains For Wireless Onboard Communications, Dario Hinojosa

Theses and Dissertations

With the increasing length of freight trains, maintaining reliable wireless communication for onboard sensors has become increasingly challenging. Sub-GHz communication bands are a promising solution due to their long-range capability and suitability for rural railway environments. This study analyzes radio wave propagation around freight railcars to evaluate path loss and determine how antenna polarization affects wireless communication performance.

Time-domain full-wave electromagnetic simulations were performed using simplified railcar models and later validated through field testing using a vector signal generator, vector network analyzer (VNA), and spectrum analyzer. Various antenna polarization configurations were evaluated within the Sub-GHz Long Range (LoRa) frequency band …

Teaching Under Restriction: Pre-Service Teachers’ Experiences With Censorship, Johnny Salinas

Theses and Dissertations

This qualitative study examined the perceptions of pre-service teacher candidates at a predominantly minority university in South Texas about educational censorship in K–12 schools. Grounded in critical theory, the research explored how restrictive policies—including book bans and legislation related to race, gender, and identity—affect candidates’ developing professional identities and career aspirations. Data were collected through an anonymous, open-ended questionnaire and analyzed to identify six interconnected themes: autonomy and fear, book bans, policy and legislation, race and identity, subject-specific impacts, and readiness and confidence. Participants described an increasingly tense educational climate marked by heightened scrutiny and ambiguous policy expectations. They voiced …

Soil Water Content Beneath Agrivoltaic Installations In A Subtropical Semi-Arid Climate, John Justin Rodriguez

Theses and Dissertations

Agrivoltaics (AV) not only beneficially influences agricultural microclimates in the field, AV systems can generate on-site energy to offset operational costs, diversify income sources, and improve overall resilience, while providing environmental co-benefits such as reduced heat stress on plants and improved resource use efficiency. This thesis evaluated agrivoltaic shading effects on SWC and soil temperature using high-resolution in situ measurements collected over one year in an active vineyard, incorporating row type, soil depth, shading, and time of day. With precipitation as the primary water source, shaded soils exhibited up to 24.53% lower SWC relative to sun-exposed soils, likely due to …

Multivariate Time-Series Forecasting Of 24-Hour Ambulatory Blood Pressure Using Long Short-Term Memory And Temporal Fusion Transformers, Sebastian Alejos Torres

Theses and Dissertations

Time series play a central role in healthcare by enabling continuous patient monitoring and forecasting of physiological and clinical measurements. Traditional models, such as autoregressive integrated moving average (ARIMA), are limited in capturing nonlinear dynamics and irregular sampling. In this study, we develop and evaluate Long Short-Term Memory (LSTM) networks and Temporal Fusion Transformers (TFTs) to forecast 24-hour ambulatory systolic and diastolic blood pressure (SBP and DBP) time series enriched with demographic and clinical features. Mean absolute error (MAE), root mean squared error (RMSE), mean absolute percentage error (MAPE), and R² were used to evaluate predictive accuracy and temporal pattern …

Structure–Property Engineering Of Sn-Based Hybrid Perovskites Via Bulky Organic Cation Incorporation: From 3d To 2d Architectures, Kevin Alejandro

Theses and Dissertations

This thesis investigates tin-based hybrid organic/inorganic perovskites (HOIPs) as a lead-free alternative to silicon solar cells. To manipulate optoelectronic and efficiency of the semiconductors, methylammonium was substituted with bulky propylammonium and tetrabutylammonium cations to induce quasi-2D/3D Ruddlesden-Popper phases. X-Ray Diffraction confirmed 2D layered phases in propylammonium hybrids (5-15%), while tetrabutylammonium hybrids faced steric limits, triggering vacancy ordered perovskite phases at 1% concentration. Optical analysis showed a bandgap narrowing from 1.30 eV to 1.26 eV with increased substitution. Although photovoltaic performance generally declined, the 10% propylammonium hybrid achieved the highest fill factor of ~0.79, indicating superior internal charge transport. This work …

Writing And Witnessing Ourselves Into Being: Testimonios Of A Chicana Educator And Latine Students For Social Justice In A Writing Course At A Hispanic Serving Institution, Amy Montoya

Theses and Dissertations

A qualitative study of first-year writing students at a Hispanic Serving Institution (HSI) sought to understand the extent to which the practice of writing testimonios transformed how students constructed their sense of identity for social justice. Guided by the research question: How does the practice of writing testimonios in a writing course at an HSI shape faculty and student identity for social justice? This qualitative study analyzed the lived experiences of three former Latine female undergraduates and the researcher in a co - participatory testimonio methodology study. Grounded in the conceptual frameworks of decolonization (Mignolo & Walsh, 2018; Paraskeva, 2013) …

Bridging The Gap: A Gap Analysis Of Commercial Pilot Training And Emerging Advanced Air Mobility Training Needs, Yarisse Adorno-Oyola

Theses and Dissertations

The integration of Advanced Air Mobility (AAM) into the national airspace presents new challenges for pilot training that are not adequately addressed by current commercial flight training standards. AAM aircraft, such as electric vertical takeoff and landing (eVTOL) aircraft, differ significantly from conventional aircraft in terms of design, propulsion, and automation. As a result, pilots will require new training that goes beyond the traditional fixed-wing or rotorcraft training offered under 14 C.F.R. Parts 61 and 141. The current study conducted a gap analysis to evaluate the alignment between current commercial pilot training and AAM's emerging training needs. Deficiencies in current …

A New Approach To Generate Combinatorial Patterns In Logical Analysis Of Data And Its Application To Predict College Retention, Salihah Ahmed E. Jaafari

Theses and Dissertations

Student retention and degree completion remain central challenges for higher-education institutions, with significant implications for student success, institutional effectiveness, and public accountability. While advances in predictive analytics have enabled earlier identification of students at risk of withdrawal, many commonly used machine learning approaches suffer from limited interpretability, constraining their practical usefulness for advising, intervention, and policy decision making. This dissertation addresses the problem of predicting student persistence by developing and evaluating optimization based, interpretable classification models within the Logical Analysis of Data (LAD) framework. Building on existing LAD formulations, this research introduces two novel pattern generation models, the Best Term …

Decomposition And Spectral Characterization Of Unsteady Loads In Pulse-Jet Propulsion Testing, Cesar Benitez

Theses and Dissertations

Pulsed jet propulsion systems produce inherently unsteady forces whose time-resolved characterization is essential for performance assessment, yet the measured load signal conflates aerodynamic forcing with the dynamic response of the measurement balance itself. This thesis develops a load centered framework for the dynamic characterization of a pulsed jet system, treating the measured load fluctuation as the primary physical observable rather than attempting full true-thrust reconstruction. A single-degree-of-freedom balance model identified through ringdown testing provides the structural reference scale, yielding a natural frequency of 8.5 Hz and damping ratio of 18%. Power spectral density, phase-averaging, and synchronous–residual decomposition is applied uniformly …

Exploration Of Extended Chemical Reaction Networks, Ramiro Santos

Theses and Dissertations

Chemical Reaction Networks (CRNs) is a well-established model for analyzing distributed and concurrent systems. A central problem studied across CRNs is the reachability problem, which asks whether a target configuration can be obtained from a given initial configuration through a sequence of valid transitions. Classical CRNs are highly expressive but not Turing-universal; their reachability problem is Ackermann-complete, indicating extremely high computational complexity that nevertheless falls short of full universality.

In this thesis, we study Extended Models of Chemical Reaction Networks in which the dynamics of the system are modified. We analyze these models through two fundamental questions. First, simulation, we …

Examining Professional Self-Doubt And Professional Quality Of Life Among Licensed Professional Counselors In Texas, Celia A. Ramos

Theses and Dissertations

Licensed Professional Counselors (LPCs) in Texas frequently navigate emotionally demanding work, including high caseloads, complex client needs, and sustained exposure to client distress. Over time, these professional demands can contribute to stress, emotional fatigue, and job strain, increasing vulnerability to burnout and reducing professional quality of life (Bardhoshi & Um, 2021; Maor & Hemi, 2021; McCarthy et al., 2010; Thompson et al., 2014). This quantitative research study examined the professional quality of life of LPCs in Texas using the Professional Quality of Life Scale (ProQOL) based on gender, ethnicity, age, licensure type, years of experience, does work setting induce compassion …

Electrical Resilience In Water Treatment Plants: An Extreme Weather And Lightning Protection Study, Genesis Martinez

Theses and Dissertations

Water treatment plants (WTPs) are vital infrastructure systems that depend on sensitive electrical, electronic, and control equipment to ensure the continuous supply of safe drinking water and effective wastewater treatment. As global temperatures rise and climate change accelerates, the frequency and intensity of extreme weather events—such as hurricanes, flooding, and increased lightning activity—are becoming more pronounced. These events pose significant risks to the electrical resilience of water treatment facilities, often leading to power outages, equipment failures, grid instability, and prolonged service disruptions. This report explores the impacts of extreme weather, with a particular focus on lightning and electrical surges, on …

A Behavior Analytic Blueprint For Rapport-Building: Investigating The Key Elements For Success, Nelmar Jacinto Cruz

Theses and Dissertations

Rapport can be defined as a positive relationship between people built through specific actions. Building rapport can benefit organizations by improving performance and increasing work satisfaction. Despite these benefits, research on rapport remains scarce. Curry et al. (2019) completed the most recent rapport study and found that rapport-building led to increased productivity and discretionary effort. The present study replicated and extended Curry et al. (2019) and addressed three limitations of their research: the lack of a control group, the large disparity in time spent with the experimenter, and the rigidity of their rapport conversation script. The study was completed in …

Porous Hydrophobic Adsorbent Coatings For Carbon Dioxide Capture, Samuel Babatunde Olushola

Theses and Dissertations

This work presents the development of a porous, hydrophobic zeolite 13X coating for the separation of carbon dioxide (CO₂) from flue gas or natural gas. Zeolite 13X was combined with yeast, glucose, and sodium alginate as pore-forming agents, and with polytetrafluoroethylene (PTFE) and Polydimethylsiloxane (PDMS) as hydrophobicity-inducing agents to enhance water resistance while maintaining CO₂ access to the adsorbent. The study explored PTFE/13X mass ratios ranging from 0 to 2.33 to investigate the interplay between hydrophobicity and CO₂ uptake. The wettability of the coating was characterized by using a temporal water contact angle (WCA) measurement. Increasing …

Degradation And Metabolic Analysis Of Synthesized Quorum-Sensing Signals By The Model Eukaryote Chlamydomonas Reinhardtii, Adam Josef Bach

Theses and Dissertations

Bacterial organisms can “talk” with one another on a colony-wide scale using a communication system known as quorum-sensing (QS) via chemical signals. These signals are produced at a basal rate throughout the life of the bacteria and are classified as autoinducers, which diffuse across the cell membrane. Once the critical concentration is reached, they begin to diffuse back into the cell and initiate a phenotypic change. As these signals exist outside the membrane of their producer, they are also accessible to other organisms. It has already been noted that some plant species uptake these compounds through their roots and break …

Range Extension Of Electric Propulsion General Aviation Aircraft Using Solar Technology, Mary Kathryn Shultz

Theses and Dissertations

Alternative propulsion technologies in aviation have been a long-time topic of interest as operators aim to bypass growing fuel prices and meet environmental sustainability requirements set globally. Research regarding alternative propulsion technologies is primarily centered around marginally improving efficiency of combustion systems or large-scale implementation of novel technologies. This research evaluates the feasibility of implementing solar-integrated propulsion for general aviation aircraft to extend range through a comparison of full-electric, hybrid solar, and internal combustion engine propulsion systems. This evaluation of existing technology by range analysis indicates that hybrid solar‑electric propulsion is viable primarily for short‑range training and recreational aircraft, rather …

Aircraft Fault Detection Via Weight And Bias Analysis Of A Custom First Neural Network Layer, George Harrison Chen

Theses and Dissertations

Fault detection in aircraft is traditionally handled through redundant hardware and comparison algorithms to detect failures. Alternatives like model-based residual generation and data-driven approaches such as supervised fault classification and unsupervised anomaly detection have been explored, but they suffer from practical limitations; model-based methods require accurate system models, and data-driven methods have large constraints on the data limiting scalability and adaptability. This work presents a purely data-driven neural network architecture featuring a custom first layer designed for real-time fault detection where the weights and biases of this layer are used to detect faults. The network requires zero supervision and complements …

Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante

Theses and Dissertations

This thesis presents the design and simulation of an 8-tube single-ring anti-resonant hollow-core fiber for sensing applications, with particular emphasis on methane gas detection at the fundamental absorption wavelength of 3.3 µm. Conventional solid-core silica optical fibers exhibit strong multi-phonon material absorption beyond 2.5 µm, rendering them fundamentally unsuitable for efficient light guidance and direct gas sensing at mid-infrared wavelengths. Anti-resonant hollow-core fibers overcome this limitation by guiding light predominantly through an air-filled hollow core via the anti-resonant reflecting optical waveguide mechanism, in which the thin silica glass walls of the cladding tubes act as Fabry-Pérot etalons that confine the …

Adaptive Artificial Potential Field Guidance And Control For Autonomous Docking With Uncooperative And Unknown Spacecraft, Steven Holmberg

Theses and Dissertations

The increasing demand for on-orbit servicing (OOS), active debris removal (ADR), and space domain awareness (SDA) missions has increased the need for autonomous spacecraft rendezvous and proximity operations (RPO) with uncooperative and unknown targets. Traditional guidance and control methods are typically designed for cooperative systems with known geometry and state information. This work builds on previous research to develop and evaluate an artificial potential field (APF)-based control framework capable of autonomous operation with minimal prior target knowledge and applicability to both relatively static and tumbling spacecraft.

The proposed APF formulation incorporates established safety constructs from cooperative docking systems, including an …

Moon Adaptive Technology For Extraterrestrial Architectural Robotics (Matear), Candela Noemi Solis Zampini

Theses and Dissertations

The Moon Adaptive Technology for Extraterrestrial Architectural Robotics (MATEAR) focuses on the development of an autonomous robotic system capable of providing structural building blocks directly from lunar regolith. As a sustained human presence on the Moon becomes a necessity, the costly and limited payload capacity associated with transporting construction goods from Earth creates a critical challenge. MATEAR addresses this problem through in-situ resource utilization (ISRU), integrating a regolith processing system onto a remote operated vehicle. The proposed system is designed to collect lunar dust, mechanically compact the material, and apply thermal treatment to enhance cohesion through sintering. These regolith-made bricks …

Moodify: A Mood-Based Music Recommendation System, Meghana Kagitha

Theses and Dissertations

Music has long been recognised as a powerful tool for emotional regulation, yet existing music streaming platforms often fail to align song recommendations with a user's current emotional state. Moodify is a mood-based music recommendation system designed to bridge this gap by delivering personalised playlists that reflect how a user feels in real time.

This project presents the design, development, and evaluation of Moodify, a mobile application that leverages the Circumplex Model of Emotion to capture user mood through an intuitive two-dimensional valence-arousal interface. Rather than relying on text input or manual search, users plot their emotional state directly onto …

Low-Vision Students’ Experiences With And Suggestions To Improve Desktop Virtual Reality: A Qualitative Study, Tanveer Mansur Syed

Theses and Dissertations

Visually impaired students have faced challenges in the field of education, particularly in science education. Not surprisingly, the unemployment rate for working-age visually impaired people has been above 70%. This persists despite federal laws to support the education and employment of visually impaired people,

Virtual Reality (VR) technology has evolved for several decades. Its use has proliferated in areas that include education. Today, VR science lab simulations are presented as a cost-effective alternative to traditional science labs. Research shows these to be viable substitutes to traditional science labs without a significant drop in learning outcomes. However, this researcher was unable …