Digital Commons Network^™

Characterization Of Lower Rio Grande Valley Watershed, Abdulkabir O. Aduragba

Theses and Dissertations

The Lower Laguna Madre (LLM) is considered impaired because of the high concentration of bacteria and low level of dissolved oxygen (DO). LLM receives freshwater from the Lower Rio Grande Valley (LRGV) watershed. In other to understand the impairment, LRGV watershed is being studied by relying on water quality data of the contributing drainages and State resource geographic data to identify watershed boundary and pollutant sources.

The study on the North and Central LRGV watershed shows some correlation between the concentration of E. coli/Bacteria, Ammonia, Total Kjeldahl Nitrogen, Total Phosphorus, Nitrate and Nitrite, Chlorophyll-a and the sources of pollutant in …

The Relationship Of Graduating Students (Alumni-To-Be)’S Sense Of Belonging And Their Intent To Give Back To Their Alma Mater At A Hispanic Serving Institution (Hsi) In South Texas, Lanlan Alvarado

Theses and Dissertations

Higher education institutions are increasingly relying on funding from the private sector (Council for Aid to Education, 2013) as state funding to higher education has decreased in recent years. Bridging the gap between university financial needs and available funding has become a high priority. In the process, higher education institutions have enlisted their advancement offices towards such bridging efforts by systematically bringing in financial support from donors, alumni, corporations, and foundations.

Funding from private sources fluctuates with changes in the macro-economic environment, laws, and regulations, as well as shifts in philanthropic interests in the public. Alumni giving constitutes a substantial …

The Relationship Between South Texas Principals’ School Climate, Leadership Style And The Use Of Communication Through Social Media And Other Methods, Alberto R. Canales Jr.

Theses and Dissertations

The purpose of this study was to examine the relationship between principals’ school climate (supportive, directive, engaged, frustrated, and intimate behaviors), leadership style, and frequency of communication with teachers. In doing so, a test of significance was carried out using an F-distribution, an alpha level of .05, and a multiple linear regression analysis as the statistical method. School climate, the dependent variable, was tested to find which independent variables, leadership style and frequency of communication, were related and to what amount these variables contributed to the total variance in school climate.

The results revealed that supportive behavior in school climate …

Flowers For The Dead, Joaquin Castillo Jr.

Theses and Dissertations

This collection of poetry and photography is a practice in creating a multimodal work that gives equal weight to each medium. These are presented as three sections, Mictlān, Kingdom of the Sun, and Old 83; for the purpose of this manuscript, they are in reverse chronological order. The first two sections use the trials of Mictlān as a narrative throughline to explore language, displacement, and the loss and mourning of indigenous identity. These pieces are a criticism against the systemic issues and institutional violence that contribute to the ongoing disenfranchisement of borderlands communities and people. The third section is more …

Faculty Perceptions Of Online Instruction And Educational Technology In Higher Education, Raul Nick Cabrera

Theses and Dissertations

The purpose of this research was to obtain faculty perceptions of online instruction and educational technology in higher education. Data was collected from eight participants through interviews and open-ended questions at a higher education institution. Results showed that faculty consider that online instruction is only possible for certain programs and that it’s only for certain student populations. In addition, faculty perceive online learning environments as a repository for class information and serve as a communication medium between instructor and student. Furthermore, faculty believe that there is no substitution for traditional teaching methods regardless of the educational technology available. Theoretical and …

Effect Of Elevated Temperature And Roundup Exposure On Oxidative Stress And Antioxidant Status In The American Oyster, Afsana Chowdhury

Theses and Dissertations

Aquatic organisms are frequently exposed to various environmental stressors. In this study, we observed the short-term (1-week) combined dose-dependent effect of Roundup, a glyphosate-based herbicide, and high temperature (30°C) on the morphology of gills and digestive glands, expression of heat shock protein-70 (HSP70), dinitrophenyl protein (DNP), nitrotyrosine protein (NTP), antioxidant enzymes such as catalase (CAT) and superoxidase dismutase (SOD) in tissues of American oyster (Crassostrea virginica). Histological analyses showed an increase in mucous production in the gills and digestive glands, hemocyte aggregation in the connective tissues as well as structural change of the lumen in the digestive glands …

Teacher Perceptions Of Instructional Feedback, Rita Caltabiano-Carrillo

Theses and Dissertations

The instructional feedback cycle is an essential tool in the field of education. When implemented successfully, feedback has the potential to significantly affect student and teacher growth. However, instructional feedback frequently goes unimplemented or unvalued, which can potentially lead to a decrease in student performance or the instructional effectiveness of the teacher. The purpose of this quantitative research study is to examine teacher perceptions of feedback received from instructional coaches and to examine seasoned and unseasoned teachers’ implementation of feedback in their instructional practices. This study focuses on the teacher population at a public charter school district in Texas.

Analysis Of Post-Translational Modifications (Ptm) Crosstalk, Amit Das

Theses and Dissertations

Mass spectrometry-based proteomics is a powerful tool for identifying post-translational modifications (PTMs) across the proteome. O-GlcNAcylation and phosphorylation are two PTMs that play crucial roles in regulating cellular processes, including cardiac contractile function. Dysregulation of these PTMs has been implicated in the development and progression of diabetic cardiomyopathy. In this study, we aimed to investigate the interplay between O-GlcNAcylation and phosphorylation in healthy and type 2 diabetic hearts, with a specific focus on the functional relationships between these PTMs and their potential therapeutic implications.

Utilizing mass spectrometry data, we identified and quantified specific PTMs on myofilament proteins, uncovering 1354 O-GlcNAcylated …

Creation Of A College Math Club For High School Students, Lilian N. Chavez

Theses and Dissertations

This study aimed to investigate the variables that contribute to high school students' desire to join a math club, specifically the FMiM VIP Club, which is an extension of UTRGV's Follow Me into Math research project. The research utilized multiple questionnaire s to examine the combination of factors that contribute to the students' attitudes toward the math club. The participants were high school Algebra 2 students from two different schools, and the study was conducted in two stages. The first stage was conducted in the Spring of 2022, focusing on girls' math identity and their interactions with the FMiM VIP …

Sweet Potato In The Lower Rio Grande Valley: Evaluating Performance Across Several Cultivars, Jon Dale

Theses and Dissertations

In Texas’ subtropical, semiarid Lower Rio Grande Valley (LRGV), citrus and sugarcane cultures have dominated specialty crop production for more than a half-century. However, the future of these high-dollar crops is becoming uncertain with increases in exotic pathogens, intensifying urbanization and the overarching complexities of both climate change and binational governance of Rio Grande Basin waters. For these reasons, the region’s specialty crop sector needs to be ready for alternatives that could benefit both market outlets and reduced input dependencies. Sweet potato (Ipomoea batatas), commercially grown in various similar climates worldwide with limited water resources, could be one …

Self-Supervised Representation Learning For Motion Time Series: A Case Study In Activity Recognition, Luis Carlos Garza Perez

Theses and Dissertations

In this thesis we will learn about what contrastive learning and time series are and understand the differences between supervised and self-supervised frameworks in machine learning. In addition, we will describe how the newest and most efficient self-supervised learning framework for visual representations to this date works, called SimCLR, which was originally developed to obtain useful vector representations from static images. We will also explain what TS2Vec is, and how a combination of both approaches can be applied to the concept of a time series, and still be able to extract a vector representation of the subject described by the …

The Role Of The Similarity Between Suppliers' And Buyers' Sustainability Practices In Improving Suppliers' Performance: An Empirical Investigation, Kwanheui Cheon

Theses and Dissertations

Sustainability has become an essential component of corporate survival and prosperity. As a result, companies are eager to introduce sustainability to every part of their businesses. In addition, because stakeholders' interest has spread from companies to their entire supply chain, companies must manage their relationships with other supply chain members regarding sustainability. Consequently, there has been an interest in investigating the implementation and management of sustainability along supply chains. However, there are still voids in sustainable supply chain management research. For example, scholars have pointed out the need for research on sustainability from a supplier perspective as opposed to the …

Population Genetics Among Rhipicephalus Sanguineus Ticks In The Lower Rio Grande Valley, Bianca Liana Guerra

Theses and Dissertations

Rhipicephalus sanguineus is a common tick species in the lower Rio Grande Valley of both human and veterinary concern. Two lineages of R. sanguineus have been described across the United States known as the tropical and temperate lineage. Both lineages can be differentiated morphologically, genetically, biologically, and by vector competence. The species name for both lineages has not been well established therefore this thesis will utilize their widely used identification. Both lineages have been identified in Texas. While the distribution of these lineages has been well-defined in some regions across the world, recent studies have observed sympatric populations in certain …

“Screen Riders” An Exploration Of Breaking Away From The Norms Of Cinematic Storytelling, Jake Alexander Escamilla

Theses and Dissertations

Throughout my time in college, I would always hear people discussing how originality is dead and that everything has been done before. Though I do believe there is some air of truth to these statements, I hold tight to the idea that originality is not truly gone. My belief is that the entertainment industry is so set on playing it safe, they do not wish to break away and explore new ideas which have never been done before. I believe that if more creatives were given the freedom to try new combinations and had more fun doing what they love, …

Formation Control Of Multiple Quadrotors, Miguel Alejandro Garcia

Theses and Dissertations

This thesis studies formation control of multiple quadrotors under different conditions. Two controller design approaches are proposed. In the first approach, it is assumed that the dynamics of each quadrotor is unknown and there is disturbance. With the aid of distributed estimation and the universal approximation property of neural networks, distributed tracking controllers are proposed. Simulation shows the effectiveness of the proposed controllers. In the second approach, it is assumed that the inertia parameters are unknown. With the aid of distributed estimation, online data estimation, and optimal control theory, distributed sub-optimal tracking controllers are proposed. Simulation results show the effectiveness …

Irreverent Womanhood: The Healing Of Intergenerational And Cultural Trauma In The Chicanx And Latinx Sonic Poetry Of Amalia Ortiz And Melissa Lozada-Oliva, Yasmine A. Gomez

Theses and Dissertations

The connections between nontraditional forms of literature and spiritual activism lie within the resistive practices of Chicanx Feminism. This thesis argues that cultural healing and social change is dependent upon the recognition of trauma as a step towards enacting social justice. Additionally, this thesis focuses on the figure of Coyolxauhqui and indigenous motherhood to reveal procedures for change. Through the theory of trauma, this thesis examines the nontraditional Chicanx/Latinx poetry of Amalia Ortiz’s sonic rock opera, Cancíon, Cannibal, Cabaret, & Other Songs and Melissa Lozada-Oliva’s novel in verse, Dreaming of You.

My investigation into the breaking of gendered …

Graphene-Conductive Ink Coated Laser Engraved Kapton Electrochemical Biosensor For The Detection Of Dopamine And Immune Sensing, Dipannita Ghosh

Theses and Dissertations

Novel and flexible disposable laser-engraved Kapton (LEK) electrodes modified with graphene conductive inks have been developed for dopamine and Interleukin-6 (IL-6) detection. The LEK sensors exhibit high reproducibility (RSD=0.76%, N=5) and stability (RSD=4.39%, N=15)after multiple bendings, and thus make the sensors ideal for wearable and stretchable bioelectronics applications. We have developed graphene conductive ink- PEDOT:PSS (G-PEDOT:PSS) and polyaniline (G-PANI) based electrode coatings for working electrode modification to improve the sensitivity (41.41 times higher for screen printed electrode with G-PEDPT:PSS ink modification),and limit of detection (LOD) . We have further compared the performance of the fabricated electrodes with commercially available screen-printed …

Nepantla – Examining The Sacred Middle Ground Of Syncretism, Jose Luis Garcia Iii

Theses and Dissertations

As a result of historical traumas caused by the Spanish invasion of Mexico, the autonomy of its Indigenous peoples has been replaced by a Eurocentric identifier based on a colonial language and theologies. Because of the vastness surrounding the Nahua pantheon, Spanish and Church officials relied on guided syncretism as means of correcting their methodologies in converting Mexico’s Indigenous population. This thesis examines syncretism as a process of religious mixing and its residual cultural changes that affected Mexico’s Indigenous populations. This ethnographic research argues that syncretism as an overarching, universalized term is insufficient to describe this process in the Chalma …

The Processing Of /Ɪ/-/I/ And /Ɑ/-/Æ/ Contrasts In Spanish-English Bilingualism, Elizabeth M. Garza

Theses and Dissertations

The following study utilizes an experimental paradigm known as the Sequence Recall Task (Dupoux et al., 2001) to examine the processing of the English vowel contrasts /ɪ/-/i/ and /ɑ/-/æ/ among Spanish-English bilinguals. Using dominance scores calculated from the Bilingual Language Profile (Birdsong et al., 2011), this study examines the processing of these contrasts relative to a control contrast /u/-/ɛ/ as well as how the processing of these contrasts is modulated by participants’ English dominance. A total of 24 Spanish-English bilingual speakers participated in a Sequence Recall Task that targeted the processing of these three contrasts. The results indicate that participants …

Quality Of Life Among Caregivers Of Individuals With 22q11.2 Deletion Syndrome And Intellectual Disability, Sandra Garza Ochoa

Theses and Dissertations

Caregiving for a person with 22q11.2 chromosome deletion syndrome (22q) often entails dealing with medically life-threatening complications and is significantly compounded when the care recipient has comorbid 22q and intellectual disability (ID). The purpose of this study was to examine the effect of support, spirituality, and resiliency on the quality of life (QOL) of caregivers of individuals with comorbid 22q/ID to ascertain if these protective factors would reduce their caregiving burden. Study participants consisted of 469 caregivers of persons with 22q/ID who were recruited through 22q social advocacy groups. Correlational analyses, analyses of variance, and multiple regression analysis were used …

Attitudes And Compassion Of Student Counselors-In-Training Toward Individuals Who Are Homeless, Kristine R. Gonzalez

Theses and Dissertations

With the increased numbers of homeless individuals over the past several years, it is important to consider factors that contribute to chronic homelessness, including barriers to service delivery that impede one’s ability to exit homelessness. The purpose of this quantitative study was to examine the attitudes and compassion among student counselors-in-training (SCITs) toward individuals experiencing homelessness as these students represent future mental health providers who will be serving the homeless, a highly marginalized population. A total of 162 graduate students from two southwestern Hispanic-serving institutions were recruited for the study. A correlational analysis, independent t-tests, and one-way ANOVAs were conducted …

Microwave-Assisted Depolymerization Of Poly (Ethylene Terephthalate) Via Ethanolysis, Mayra Alejandra Gomez Cortez

Theses and Dissertations

In the search of providing an alternative form of combating the complex environmental concerns rising from the rapid growth of poly (ethylene terephthalate) waste in the world, this research focused on investigating the chemical recycling of PET via ethanolysis. Parameters such as temperature, reaction time, catalyst usage and concentration were investigated to promote depolymerization.

In this work, ethanolysis of waste PET under microwave irradiation was investigated using organocatalysts 1,5,7-Triazabicyclo [4.4.0] dec5-ene (TBD) and 1,8-Diazabicyclo [5.4.0] underc-7-ene (DBU). We evaluated the effectiveness of reaction conditions through a series of experiments and determined the optimum conditions as follows: 0.5 g of PET, …

Study Of Population Dynamics Of Sugarcane Aphid (Melanaphis Sacchari) In Rio Grande Valley, Texas, Neetu Khanal

Theses and Dissertations

Chapter 1: This chapter incorporates detailed information about the biotype concept, aphids, their types and their biotypes, importance of studying insect biotypes and their role in mediating host plant defenses.

Chapter 2: This chapter explains in detail about the biology, biotypes, feeding behavior, damage, and economic loss caused due to sugarcane aphid infestation. This chapter further elaborates on the need for studying population level differences and justifies the objectives and significance of this research study.

Chapter 3: This chapter provides information about the comprehensive work done on three different populations of sugarcane aphid collected from three different locations in Rio …

Developing Executable Digital Models With Model-Based Systems Engineering – An Unmanned Aerial Vehicle Surveillance Scenario Example, Viviana Guadalupe Lopez

Theses and Dissertations

There is an increase in complexity in modern systems that causes inconsistencies in the iterative exchange loops of the system design process and in turn, demands greater quality of system organization and optimization techniques. A recent transition from document-centric systems engineering to Model-Based Systems Engineering (MBSE) is being documented in literature from various industries to address these issues. This study aims to investigate how MBSE can be used as a starting point in developing digital twins (DT). Specifically, the adoption of MBSE for realizing DT has been investigated, resulting in various literature reviews that indicate the most prevalent methodologies and …

Data Science For Hospital Antibiotic Stewardship, Saikou Jawla

Theses and Dissertations

Antibiotics are widely used to treat bacterial infections, but their misuse leads to antibiotic resistance. Antibiotic resistance is one of the biggest threats to global health, food security, and development today. Antibiotic resistance leads to higher medical costs, prolonged hospital stays, and increased mortality. Antimicrobial stewardship is an approach to measure and improve the appropriate use of antibiotics in healthcare settings. Data science has the potential to support these programs by providing insights into antibiotic prescribing patterns, identifying areas for improvement, and predicting patient outcomes. We explored the role of data science in hospital antibiotic stewardship programs, including statistical methods …

An Analysis Of Antichimeral Ramanujan Type Congruences For Quotients Of The Rogers-Ramanujan Functions, Ryan A. Mowers

Theses and Dissertations

This paper proves the existence of antichimeral Ramanujan type congruences for certain modular forms These modular forms can be represented in terms of Klein forms and the Dedekind eta function. The main focus of this thesis is to introduce the necessary theory to characterize these specific Ramanujan type congruences and prove their antichimerality.

Monitoring Of Ac Motors Parameters Using Industrial Internet Of Things, Mohammad Muheisen

Theses and Dissertations

In this thesis, the industrial internet of things has been introduced, as a very newborn research field. The suggested prototype has been assembled at the university laboratory to simulate the system conditions. Two three-phase induction motors have been utilized to perform this study, to monitor and gather data, regarding vibration and temperature. As a very newborn field, the data collected from the two motors can be analyzed to achieve a couple of goals, in energy consumption, to reduce the financial burden of the remedy works. A fast Fourier transformer has been applied to measure the motor's vibrations, and the current …

An Investigation Into Optimal Descent Trajectories For Multipurpose Long Range Space Vehicles Under Advanced Conditions, John M. Levis

Theses and Dissertations

In this work, we investigate the problem of fuel-optimal control of space vehicle descent trajectories. The main tool we use to establish optimality is Pontryagin’s Maximum Principle. We present a variety of scenarios with increasing complexities, including drag, wind, and moving landing platforms in the context of differing atmospheric and gravitational conditions. Throughout the paper, we use a balance of analytical and numerical techniques. Finally, observations and conclusions drawn from the investigation form the basis for suggestions into additional areas of analysis.

Flow Monitoring And Tidal Exchange Ratio Estimation For The Bahia Grande After Widening Of The Carl Joe Gayman Pilot Channel: Bahia Grande, Cameron County, Tx, Sabas Lopez Iii

Theses and Dissertations

The Bahia Grande (BG) is an 8,500-acre set of coastal bays and wetlands located between Brownsville and Port Isabel, Tx, near the Gulf of Mexico (GOM) coastline. In 2005, the Carl Joe Gayman Pilot Channel was constructed to address hypersalinity concerns that resulted from natural and anthropogenically-caused tidal isolation since the early 1940’s. In 2022, the Texas General Land Office (GLO) increased the channel’s width and depth in anticipation of increasing tidal exchange ratios by a factor of two to three. Once the channel widening was complete, two SL-1500-3G side-looking acoustic doppler current profilers (ADCPs) were periodically deployed beneath the …

Wave Excited Mass-Spring-Damper System For A Self-Recharging Autonomous Underwater Vehicle, Mahmodul Hasan Maheen

Theses and Dissertations

Autonomous underwater vehicles' (AUVs) endurance is constrained by the lifetime of their batteries and the distance that tether wires can traverse. Solving the endurance problem of AUV using the enormous potential of ocean wave energy is the motivation behind this thesis. The objective of this research is to model a mass-spring-damper system to emulate the permanent magnet linear generator (PMLG) of a self-recharging AUV and identify its energy absorption capability through numerical simulation and experimental testing. The research activities started with modeling and fabricating a 1:5 scale model. The scaling was done by comparing the most common AUV size of …