Digital Commons Network^™

Supplementing Tannins To Increase Performance And Reduce Methane Emissions In Cows Grazing On Western Grasslands, Horacio Pedro Blanchard

All Graduate Theses and Dissertations, Fall 2023 to Present

Cattle grazing on U.S. rangelands often rely on a limited diet made up mostly of grasses. As the seasons change from spring to fall, the nutritional quality of these grasses declines, leading to less efficient digestion and higher production of methane—a potent greenhouse gas. In addition, most grass-based pastures lack beneficial plant compounds, such as tannins.

This study explored whether adding natural tannins—specifically, condensed and hydrolyzable tannins from quebracho and chestnut trees—to the diet of grazing cattle could improve how the use efficiency of nutrients and reducing methane emissions from cattle. Over two years, 24 cow-calf pairs grazed in small …

A Value Sensitive Design Approach To Reimagining Parental Control Apps, Prakriti Dumaru

All Graduate Theses and Dissertations, Fall 2023 to Present

Parental control apps are often used by families to regulate children's device usage and keep them safe online. However, existing tools focus on monitoring and restricting children, which can lead to tension and mistrust within families. This research takes a new approach by exploring how parental control apps can be redesigned to support positive family values, like encouraging open communication between parents and children and helping children self-regulate their behaviors. Through four in-depth studies, this dissertation looks at how these values play out in different real-life situations. It includes families with children on the autism spectrum, divorced households where parents …

A Computational Study On Impact Performance Of Concrete Barriers For Protecting Transportation Assets, Ashesh Pokhrel

All Graduate Theses and Dissertations, Fall 2023 to Present

Highway safety is a major concern as roads accommodate increasing numbers of vehicles, including large trucks and tractor-trailers. Concrete barriers are commonly used along highways and bridges to prevent accidents by redirecting vehicles and protecting important structures like bridge piers. However, their effectiveness depends on how well they withstand vehicle impacts, how they perform after being damaged in previous crashes, and how they protect bridge piers when space is limited. This research examines these issues using advanced computer simulations to better understand barrier performance and improve roadway safety.

The first part of this study reviews how researchers and engineers use …

Modeling For Functional Traits In Bluebunch Wheatgrass Using Unmanned Aerial Vehicle (Uav) High-Throughput Phenotyping, Brittany L. Johnson

All Graduate Theses and Dissertations, Fall 2023 to Present

Changing climates and shifts in community composition in the Intermountain West threaten sagebrush-steppe ecosystems, impacting both plants and animals. Restoring native grasses like bluebunch wheatgrass (Pseudoroegneria spicata; BBWG) can help ecosystems resist invasive species and recover from stress and disturbances. As a native cool-season grass, BBWG is widely used in rangeland restoration for the western U.S. Breeding programs for restoration plant materials, such as seeds for ecological projects, often require years or decades of field testing while facing staffing constraints. High- throughput phenotyping (HTP), which rapidly measures observable plant traits, offers a faster solution using drones to capture time-series …

Beyond The Click: Investigating Mental Models, Targeted Attacks, And Behavioral Interventions Against Clickbait, Ankit Shrestha

All Graduate Theses and Dissertations, Fall 2023 to Present

Clickbait is misleading or exaggerated content on social media that tricks people into clicking on links by making them curious. For instance, posts that use headlines such as “This is the worst day to visit a restaurant”. These clickbait posts can lead to fake news, wrong information, and even harmful websites. Even though many people know clickbait can be risky, they often still fall for it. Existing tools to stop clickbait don’t always consider how people think, the situations they are in, or their different needs. This research looks at how people understand and react to clickbait, and develops different …

Markerless Clinical Gait Identification Using Computer Vision Techniques And Artificial Intelligence, Katelyn Conroy

Open Access Theses & Dissertations

Pose estimation algorithms could provide an unbiased examination for diagnosis, progression, and rehabilitation. PURPOSE: The purpose of this study was 1) to critically identify and appraise literature investigating spatiotemporal and kinematic gait characteristics in individuals with idiopathic Parkinson's Disease and spastic diplegic Cerebral Palsy compared to healthy controls; 2) to examine the validity and reliability of spatiotemporal gait characteristics and upper- and lower-body joint kinematics of OpenPose and the agreement with marker-based motion capture in healthy individuals; and 3) to examine the sensitivity, specificity and predictive values of a proposed clinical diagnostic tool using OpenPose in the diagnosis of idiopathic …

Restoring Balance: Choctaw Policy And The Environment In New Spain's Eighteenth-Century Frontier, Fior Daliso Garcia Lara

Open Access Theses & Dissertations

During the colonial period, Indigenous peoples in the Lower Mississippi Valley used their deep ecological knowledge to respond to imperial pressures. Eighteenth-century Louisiana was a contested borderland where Spain, France, and England vied for expansion through alliances, warfare, and trade with Native tribes. As European powers vied for control of the region, Native groups devised strategies to assert sovereignty over their territories and livelihoods. My dissertation examines the ecological history of the Choctaw and Spanish Louisiana from 1763 until the United States Indian Removal Act in the 1830s. It argues that imperial disputes over Indigenous lands compelled the Choctaw to …

Application Of Distributed Fiber Optic Sensing (Dfos) For Monitoring Asphalt Pavement Strains Under Accelerated Loading Conditions, Sebastian Morales

Open Access Theses & Dissertations

This thesis presents a study on the application of Distributed Fiber Optic Sensing (DFOS) technology for detecting pavement's strain response with high spatial resolution. Using a Rayleigh-based optical frequency domain reflectometry (OFDR) system, DFOS sensors were calibrated and embedded in full-scale asphalt slabs subjected to accelerated loading using a Model Mobile Load Simulator 3 (MMLS3). Calibration of the DFOS sensors was conducted using a three-point bending flexural test with known load conditions and reference strain gauges to validate theoretical and numerical models. The results demonstrate DFOS's capability to detect pavement response under static and dynamic loading, as well as changes …

Systematics Of African River Frogs (Anura: Pyxicephalidae: Amietia) In Central Africa, With The Description Of Two New Species, Jesus Manuel Reyes

Open Access Theses & Dissertations

Amietia is a pyxicephalid anuran genus that is prevalent throughout central, southern, and eastern portions of sub-Saharan Africa. Recent phylogenetic studies have been in conflict regarding the validity and composition of several Amietia species in the Albertine Rift region. The goals of this study are to: (1) generate an updated molecular phylogeny for Central African Amietia with new sampling; (2) clarify the relationship between the previously unsampled taxa A. amieti and A. chapini; (3) clarify the status of A. desaegeri; and (4) confirm the taxonomic status of potentially new species. Maximum likelihood and Bayesian inference methods were used to generate …

The Alchemy Of Respect In The First-Year Composition Classroom, Raphael Ivan Reyes Juarez

Open Access Theses & Dissertations

In this research, I wanted to understand how respect in the First-Year Composition classroom was understood, applied, and negotiated by undergraduate students. Also, I proposed a concept called the alchemy of respect, which describes the transformations, addition of value to students' ideas, and the refinement of their abilities in the classroom. The study relied on three theoretical approaches: virtue ethics by John Duffy, community literacy by Linda Flower, and rhetoric of respect by Tiffany Rousculp. I found important concepts in their work, such as the analysis of morals in the decisions people make, the construction of communities across differences, and …

Systematics, Evolution, And Species Delimitation Of Ichneumonidae (Hymenoptera) Based On Ultraconserved Element Phylogenomics, Brandon Ross Claridge

All Graduate Theses and Dissertations, Fall 2023 to Present

The diversity of life on Earth is highly skewed towards a few key groups of organisms. Parasitoid wasps are among the most species-rich yet understudied organisms on our planet. Ichneumonidae, the largest parasitoid wasp family, includes 25,000 known species out of an estimated total of 100,000, far exceeding the nearly 70,000 species of vertebrates. As parasitoids, ichneumonids lay a single egg onto or inside their hosts, and the resulting ichneumonid larva consumes its host, ultimately killing it. Most hosts are the larvae or pupae of moths, butterflies, flies, beetles, and other wasps, including many pest species injurious to agriculture and …

Political Violence, Electoral Behavior, And Their Interaction With Identity, Zeeshan Saeed

All Graduate Theses and Dissertations, Fall 2023 to Present

The research takes Pakistan as a case-study to explores how political violence shapes electoral behavior by focusing on two forms of violence: terrorist interventions by non-state actors and political repression by state institutions. Analyzing multiple elections and regional contexts, the study investigates how fear inflicting non-state violence can discourage voter participation, while state sponsored violence can drive communities by triggering anger, particularly those with strong ethnic identities leading to a higher voter turnout. Overall, this work highlights how different types of violence have varying effects on voter participation, and how these effects are conditioned.

The Effects Of Temperature And Cardiotonic Steroids On Cardiac Function And Metabolism In Snakes, Hannah Wilson

All Graduate Theses and Dissertations, Fall 2023 to Present

The function of the heart provides a window into the physiology of vertebrates and a means of evaluating their response to the stresses imposed by diverse activities. I developed a miniaturized instrument to record electrocardiograms (ECGs), using open-source Arduino technology, that a snake can wear as a backpack. The backpack can also be used when the snake is in a metabolic chamber, to record the metabolic rate and ECG simultaneously. I first used the ECG backpack to record the physiology of snakes under different temperature conditions, to verify that the system worked as expected. the backpack was then used on …

Studies In Number Theory: Reciprocity Laws And Fundamental Domains, C. Xavier Parent

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis consists of two sections. The first section is an introductory survey of number theory discussing the reciprocity laws with a focus on accessibility. Number Theory has always been a fundamental area of mathematical study, with Gauss calling it “the queen of mathematics”. The reciprocity laws are a classical set of results from number theory which have driven number theory for quite a long time. Unfortunately, these results, while important, have always been very inaccessible to undergraduate students, making it hard to start studying the field. This survey attempts to help bridge that gap, giving a resource for novices …

So Much Cooler Online: Social Media Usage By Agricultural Educators In Secondary Sbae Classrooms, Saydee C. Longhurst

All Graduate Theses and Dissertations, Fall 2023 to Present

Social media has become a powerful tool in education, helping teachers connect with students and share information in new ways. Agricultural educators are using platforms like Facebook and Instagram to promote agricultural literacy and engage students in an online format. This study explores how high school agriculture teachers use social media, what challenges they face, and how comfortable they are using it. Through an online survey and analysis of social media engagement data, this research highlights the benefits and personal evaluation educators have when using these platforms. The results show that while social media helps teachers share resources and connect …

Investigating Temporally Dynamic Models Of Choice In Rats And Bumblebees, Jack Van Allsburg

All Graduate Theses and Dissertations, Fall 2023 to Present

Temporally dynamic models of choice simulate how animals use past experience to make optimal decisions in variable environments. Chapter 1 briefly reviews a series of such modeling approaches and their mathematical properties. Extension of these models to longer experiments (more than 48 hours) designed to produce spontaneous recovery of choice (a behavioral phenomenon implicated in relapse) previously led to results not described well by current models. Chapter 2 comprises an empirical investigation of different explanations for these inconsistent results using rats, evaluating the effect of different test delays on preference following varied reward conditions. The results of the first two …

Geochemical And Stratigraphic Characterization Of The Morrison Formation And Cedar Mountain Formation Contact In The Island Park Quadrangle, Uintah County, Utah, Emily Mcdermott

All Graduate Theses and Dissertations, Fall 2023 to Present

The Upper Jurassic Morrison Formation and Lower Cretaceous Cedar Mountain Formation are among the richest sources of dinosaur fossils. Despite a 24-million-year gap in time (the Jurassic–Cretaceous unconformity), these formations are difficult to distinguish due to their similar rock types and colors. In Utah's Island Park quadrangle (IPQ), these formations are not separated on existing geological maps. This study focuses on identifying and understanding the formational boundary between them using field observations, stable isotope analysis, clay mineralogy, and chemical techniques such as X-ray diffraction (XRD) and X-ray fluorescence (XRF).

Unlike other areas where a conglomerate layer marks the boundary, the …

Graph-Based Machine Learning: Higher-Order Interactions, Guided Generation, And Knowledge-Graph Tools, Thomas J. Kerby

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation brings the power of graph thinking to three key challenges in modern AI, making complex data more transparent, generative design more controllable, and scholarly exploration more intuitive. First, we introduce Local CorEx, a new machine learning technique that uncovers hidden relationships among variables, making it easier to understand complex datasets without heavy computation. Next, we show how to guide the creation of new molecules by viewing the generation process itself as a walk through a "state graph," letting researchers steer outcomes toward desired chemical properties—without any extra model training. Finally, we deliver an open-source toolkit that builds interactive …

Gender-Diverse Individuals' Mathematics Self-Efficacy, Aliya Halterman

All Graduate Theses and Dissertations, Fall 2023 to Present

Many factors influence how well someone learns and achieve in school and daily living, with motivation being especially important. One key part of motivation is something called self-efficacy, which refers to how much someone believes they can successfully do a specific task (Bandura, 1986; 1997). Research has shown that self-efficacy plays a major role in how well people do, and the quality of their efforts (Pintrich & Schrauben, 1992; Weinstein & Mayer, 1986; Zimmermann, 2000). Additionally, mathematics skills are tied to better outcomes in school, careers, and in daily life. Mathematics also has also had a complex history when it …

Three Essays On Entrepreneurial Orientation And Competitive Repertoire, Gang Fan

Open Access Theses & Dissertations

While scholars confirm the positive relationship between entrepreneurial orientation (EO) and firm performance with meta-analyses, the mixed findings with widespread effect sizes imply that this critical relationship in entrepreneurship literature deserves further inspection. In this three-essay dissertation, I integrate the entrepreneurial orientation literature with the competitive repertoire literature. Specifically, in essay 1, I develop a theoretical framework of EO, competitive repertoire, and firm performance through the lens of capability theory. In the second essay, I examine the moderating role of competitive pressure on the EO-competitive repertoire relationship with a sample of all U.S.-listed firms. Finally, I articulate and examine how …

Cellular And Noncellular Influences On Lipid Nanoparticle Tropism In The Liver, Mario Yomir Mata Corral

Open Access Theses & Dissertations

Hepatocellular carcinoma (HCC) is currently ranked as the second leading cause of cancer-related mortality worldwide, causing more than 700,000 deaths a year. The liver is important in blood filtration and metabolism, and for this reason is a prime target for drug delivery, with lipid nanoparticles (LNPs) showing promise as carriers due to their natural hepatic tropism. However, LNP efficacy is decreased in HCC due to the limited understanding of liver physiology in cancerous environments. This project proposes to address this gap by using a tissue-clearing technique known as CLARITY along with a chemically tagged LNP for comprehensive visualization of LNPs …

Simultaneous Selection Of Inflations And Variables In Multiple Inflations Poisson Model (Mip), John Koomson

Open Access Theses & Dissertations

Count data frequently arise in biomedical, economic, and social science research and are often characterized by structural excesses at specific count levels. To accommodate such patterns, Su et al. (2013), among others, introduced the Multiple-Inflation Poisson (MIP) model, which allows for multiple inflated counts within the distribution. However, two critical challenges remain in modeling such data: (i) identifying the true inflation points where excess counts occur, and (ii) selecting the relevant covariates that explain variation in the inflation and count process. This dissertation addresses these issues by advancing the MIP model through a novel methodology that enables the simultaneous selection …

Associations Between Mental Health Outcomes And Discrimination And Victimization Among Adult Lgbtq+ Community Members Or Guardians Of Lgbtq+ Children, 2023-2024, Perla Gisel Mercado

Open Access Theses & Dissertations

BACKGROUND: LGBTQ youth face unique challenges and experiences that can significantly impact their mental well-being. Discrimination, stigma, prejudice, and struggle for self-acceptance contribute to increased rates of mental health issues within this population. Almost one in 8 people, or 970 million individuals worldwide, were living with a mental disorder. PURPOSE: Assess the relationship between discrimination and victimization and mental health outcomes among sexual and gender minorities (SGMs) in the Paso del Norte Region. METHODS: Data was collected through a cross-sectional needs assessment survey among adult LGBTQ+ community members or parents/guardians of LGBTQ+ children/youth living in New Mexico or Texas in …

Spatial And Thermal Aspects Of The Ecology Of Three Sympatric Rattlesnakes In The Montane Northern Chihuahuan Desert, Joshua James Mead

Open Access Theses & Dissertations

To understand how animals coexist on the landscape, the individual aspects of a species life history must first be understood. Animals need to find locations that provide the resources they need to survive. Movement, microhabitats, and temperature can alter such areas where animals occur. Understanding animal movements provide important information on space use and microhabitats on the landscape. Ectothermic animals must acquiesce to ambient temperatures or use behavioral modifications to alter their body temperature. The ability to maintain suitable body temperature is essential for physiological function, reproduction, and ability to avoid predation. Research on the variation in a species ecology …

Evaluation Of Salt-Free Electrodialysis Metathesis For High Recovery Inland Desalination Brine Management, Tayia Oddonetto

Open Access Theses & Dissertations

Salt-Free Electrodialysis Metathesis (SF-EDM) is an emerging electro-driven membrane technology designed to minimize brine discharge while enabling selective ion separation and resource recovery. This dissertation presents an evaluation of SF-EDM, spanning bench-scale studies with synthetic brine from the Brackish Groundwater National Desalination Research Facility in Alamogordo, NM, real reverse osmosis (RO) brines from the Kay Bailey Hutchinson Desalination Plant in El Paso, TX, and finally a weeklong pilot demonstration at the Yuma Desalting Plant in Yuma, AZ. Bench-scale experiments established process feasibility and performance trends, while pilot results revealed the value of pre-treatment and system configuration. SF-EDM demonstrated high hydraulic …

Judicial And Techno-Securitization Of Immigration: Narratives De Filosofia De Inmigracion Y Justicia, Mohammad Rubaiyat Rahman

Open Access Theses & Dissertations

In the thesis, I develop a philosophical account which is centered on immigration enforcement discrimination, surveillance and procedural justice. The thesis propounds two arguments. The first argument contends that the immigration enforcement of the United States (U.S.), including the use of surveillance technology, contributes to the structural injustice. The second argument is that the U.S. immigration surveillance and immigration enforcement should be qualified by procedural justice and constitutional democracy.

The thesis prioritizes the practice of the U.S. immigration policy, enforcement and how these promote structural injustice against non-citizens and citizens, specifically those who are Latinos living in the U.S.-Mexico borderlands. …

Temporal Partitioning And Coexistence Among Four Sympatric Felid Species In The Northern Jaguar Reserve, Kylie Marie Rezendes

Open Access Theses & Dissertations

Coexistence among sympatric carnivores is shaped by behavioral strategies that mediate competition and mortality risk in heterogeneous landscapes. Understanding how sympatric carnivores, such as felids, use space and time in relation to one another requires models that account for both spatial and temporal overlap across landscapes. Models incorporating time-to-event probabilities provide a powerful framework for detecting behavioral dynamics across shared landscapes. This study evaluated the spatiotemporal responses of two apex predators â?? the jaguar (Panthera onca) and mountain lion (Puma concolor) - and two mesopredators - bobcat (Lynx rufus) and ocelot (Leopardus pardalis) - across five years of camera trap …

Aluminum Doped Tin Sulfide Thin Films For Solar Cell Applications, Gabriel Rodriguez Guijarro

Open Access Theses & Dissertations

Tin sulfide (SnS) is theorized to be a suitable material for solar cells, but there are some difficulties that have not been overcome when making thin films that have the properties needed to compete with other materials. This work investigates the structural and optoelectronic properties of aluminum-doped SnS thin films, deposited via magnetron cosputtering physical vapor deposition at different temperatures. To characterize the films a variety of techniques were used: Raman spectroscopy, SEM, TEM, X-Ray Reflectivity, and UV-Vis spectroscopy. The results show that the target stoichiometry is a relevant parameter to take into account when growing SnS thin films, the …

Phylogenetics And Integrative Taxonomy Of The Lang's Reed Frog Species Complex (Anura: Hyperoliidae: Hyperolius Langi), Dominic Troiani

Open Access Theses & Dissertations

The genus Hyperolius (Rapp, 1842) is the most speciose amphibian genus in sub-Saharan Africa. The genus has a complex taxonomic history because of its extensive intraspecific and interspecific morphological variation, large geographic distribution of many taxa, gaps in sampling, and the discovery of significant cryptic diversity within many species. The goal of this study is to understand the relationships and taxonomy of Hyperolius langi via an integrative taxonomic approach that combines molecular, morphological, and bioacoustics data to clarify the systematics of the geographically widespread species Hyperolius langi. Two mitochondrial (16S and cyt b) and one nuclear (RAG1) gene were used …

The Moderating Effects Of Motivation And Adhd On The Relationship Between Academic Burnout And Prescription Stimulant Misuse Among College Students With Adhd, Joshua Matthew Villanos

Open Access Theses & Dissertations

This study examined whether ADHD symptom severity and motivational orientations moderate relationships between academic burnout and stimulant outcomes in college students with ADHD symptoms. Using a cross-sectional survey design, 180 undergraduate students who screened positive for ADHD symptoms completed measures assessing academic burnout, motivation orientations, ADHD symptomatology, and prescription stimulant misuse behaviors and expectancies. Testing these moderation hypotheses addresses important gaps in understanding risk and protective factors that may influence stimulant misuse risk. Negative binomial regression was employed for stimulant misuse analyses using the full sample (N = 180), while linear regression examined expectancies across all participants. Results revealed one …