Digital Commons Network^™

The Role Of Microbiota On Campylobacter Jejuni Colonization And Growth Performance In Broiler Chickens, Ayidh Almansour

Graduate Theses and Dissertations

The successful poultry production at modern era comes from the vertical integratedindustrialization, which has fundamentally changed how animals have been living for millions of years. Antimicrobial growth promoters have been used to sustain the efficient industrialized animal production, driving antimicrobial overuse and resistance. Because of the increasing pressure from consumer’s concerns and government regulations, it is urgent to develop antimicrobial free alternatives as growth promoters in poultry production, but few effective antimicrobial alternatives are currently available. Campylobacter jejuni is one of the worldwide prevalent foodborne bacterial pathogens mainly transmitted from poultry. However, few mechanisms are available on why C. jejuni …

The Social Ontology Of Psychiatry: Psychiatric Diagnosis As An Ontogenetic, Interpellative Speech Act, Ashton Sorrels

Graduate Theses and Dissertations

Psychiatry is the study, evaluation, and treatment of mental disorders – disorders that affect the behavior and cognition of individuals and which are associated with underlying dysfunctions in the brain and nervous system. Though psychiatry is a medical and scientific discipline, it also takes place within a social context that modifies its effects, particularly in its application of diagnostic categories to individuals. In this thesis, I argue that, because of this context, psychiatric diagnosis can be modeled as an ontogenetic, interpellative speech act. A speech act is an utterance or sign that constitutes an action through its performance, called an …

Scheduling, Complexity, And Solution Methods For Space Robot On-Orbit Servicing, Susan E. Sorenson

Graduate Theses and Dissertations

This research proposes problems, models, and solutions for the scheduling of space robot on-orbit servicing. We present the Multi-Orbit Routing and Scheduling of Refuellable On-Orbit Servicing Space Robots problem which considers on-orbit servicing across multiple orbits with moving tasks and moving refuelling depots. We formulate a mixed integer linear program model to optimize the routing and scheduling of robot servicers to accomplish on-orbit servicing tasks. We develop and demonstrate flexible algorithms for the creation of the model parameters and associated data sets. Our first algorithm creates the network arcs using orbital mechanics. We have also created a novel way to …

Hiding In Plain Sight: Accounting For Rate Heterogeneity In Trait Evolution Models, James Boyko

Graduate Theses and Dissertations

Within the last four decades, phylogenetic comparative methods have become the defacto method of analysis for comparative biologists. The availability of high-quality comparative datasets has been matched by an explosion of possible phylogenetic models. In large part, the efforts to increase the realism of phylogenetic comparative methods has been successful as evidenced by their widespread use. To this extensive literature, my contributions are modest. I have focused my dissertation work on two main themes. First, most phenotypic evolution is not independent of other phenotypes. Changes in a particular character may influence changes in another and modeling these characters in isolation …

Hierarchically Structured Photoelectrodes Via Atomic Layer Deposition, Justin Rowan Reed Demoulpied

Graduate Theses and Dissertations

In the search for a sustainable method to meet increasing energy needs, solar energy emerges as an underutilized, plentiful resource. Solar intermittency and requirements for transportation necessitate storing solar energy in the form of chemical bonds via artificial photosynthesis. Photoelectrochemical (PEC) water splitting generates hydrogen fuel from solar energy and water. A semiconducting material that successfully meets the complex requirements for building an industrially scalable PEC device has yet to emerge. This is leading to a reevaluation of materials previously overlooked within PEC research, mainly materials with limitations such as minimal charge carrier mobility and propensity to corrosion under illumination …

Identification Of Genomic, Proteomic, And Metabolomic Signatures Associated With Pulmonary Hypertension Syndrome In Broilers, Duaa Almansaf

Graduate Theses and Dissertations

The present dissertation contains a collection of studies that examine the genomic, proteomic, and metabolomic association to pulmonary hypertension or ascites phenotype in fast-growing broilers. Pulmonary hypertension is a multifactorial metabolic disease influenced by physiological, environmental, and nutritional factors. It is characterized by a number of structural changes including, thrombosis and adverse pulmonary vascular remodeling. Thus, the atrial pressure is increased, and the right ventricle becomes hypertrophied, resulting in heart failure and the death of the bird. Pulmonary hypertension or ascites is a global problem that has negatively impacted the economy. The increased mortality rate of broilers (25%) is estimated …

Mentors In Violence Prevention: Differential Impacts On Adolescent Bystander Intentions About Bullying, Dating Violence, And Sexual Harassment, Ayla Mapes

Graduate Theses and Dissertations

Bystander approaches are promising interventions that can engage bystanders as prosocial allies to intervene in interpersonal violence situations among youth within school settings. The Mentors in Violence Prevention (MVP) bystander intervention program targets interpersonal violence using a peer-to-peer mentoring model to engage students in a discussion about violence prevention. Research on the MVP program is promising but limited. The current study examined the specificity of MVP intervention effects in two high school samples. The first was a pre/post-test design that included a smaller sample of high school students who participated in the MVP program in the 2013-2014 academic year. The …

Evaluation Of Single Phase Smart Pv Inverter Functions In Unbalanced Residential Distribution Systems, Darren Symonette

Graduate Theses and Dissertations

In the United States, smart PV inverters integrated with residential distribution systems are becoming a more common occurrence. With integration of smart PV inverters, power utilities are experiencing an increase of number of operations with regards to switched capacitor banks, voltage regulators and on load tap changers. These increases can lead to excess wear and tear on the devices causing power utilities to perform unwanted replacement and maintenance. However, smart PV inverters when controlled under specific functions can enable these inverters to provide reactive power and voltage control which in turn lowers the number of operations for switched capacitor banks, …

Collaborating With Big Brothers Big Sisters And Parents To Develop Caregiver-Initiated Mentoring, Meredith J. Scafe

Graduate Theses and Dissertations

Research shows that youth enrolled in formal mentoring programs often wait months before being matched with a mentor. This paper describes the development and pilot test of Caregiver-Initiated Mentoring (CG-IM), a program originally designed to equip caregivers to assist Big Brothers Big Sisters (BBBS) mentoring program staff in identifying and recruiting mentors from their social network. Using a mixed-methods design, the initial efficacy of the CG-IM program was evaluated via a small pilot test. I broadly explored caregivers’ experiences participating in the CG-IM program and a BBBS staff member’s experience implementing it. Caregivers completed a post-survey that included quantitative measures …

Habitability, And Evolution Of Microorganisms Under Extreme Conditions, Azarin Yazdani

Graduate Theses and Dissertations

The choice of a solvent determines the possible biochemistry of life. Life on Earth is based on carbon biochemistry and has evolved in an environment with water as a solvent. As a polar solvent abundant on Earth, water has unique physical properties, including a large range of liquidity and low viscosity, making it a very good solvent for terrestrial life. Liquids other than water are abundant in the universe, and the chemical nature of these liquids might lead to different chemistries of life. In the first chapter, we review the main characteristics of a good solvent, and then we use …

The Child In The Basement: Debilitating Mechanisms In American Science Fiction, Tessa Swehla

Graduate Theses and Dissertations

This project examines the tension between progressive narratives about the future that often frame disability as a medical condition with no place in the future and deliberate debilitation of certain populations for the sake of commodification. These two ideas would seem in conflict with one another, but together, they form a strategy of control. Using the interconnected discourses of medicine and US science fiction, this project synthesizes ideas from debility and disability theory, posthuman studies, medical humanities, and computer science and programming to demonstrate how these two ideas coexist. Each section includes an interchapter that introduces the key idea and …

Riverscape Community Genomics Of Ozark Fishes: A Comparative Framework To Infer Ecological And Evolutionary Determinants Of Genetic Diversity, Zachery D. Zbinden

Graduate Theses and Dissertations

Genetic variation is a crucial component of biodiversity and represents the variability and spatial structure of alleles within and among organisms. Evolution modulates this variability over time through mutation, selection, gene flow, and genetic drift. However, our capacity to test foundational theories of population genetics has always been at the mercy of molecular approaches available to quantify patterns of genetic diversity. Initially, techniques for empirical DNA studies were in their infancy and limited by technologies and the price per unit of genetic information. Because of these constraints, our pursuits have generally been limited to investigations of one or a few …

Conservation Of Open-Canopy-Associated Wildlife: Multi-Scale Management Impacts On Imperiled Herpetofauna, Ethan Joseph Royal

Graduate Theses and Dissertations

The loss of open-canopy ecosystems throughout North America has precipitated declines in reptile and amphibian species associated with these habitat types. Current efforts to restore open-canopy ecosystems are underway in many areas, but the local distributions of, habitat characteristics required by and the effects of management actions on many herpetofauna species are poorly understood or entirely unknown. Research examining relationships among herpetofauna and their environments is often complicated by the extremely low detectability seen in many studies. We used landscape-scale, assemblage-level surveys to investigate the occupancy patterns and habitat associations of open-canopy-associated herpetofauna in two regions, as well as gain …

Evaluating Impacts Of Development Programs On Female Education In Afghanistan, Ahmad Shah Mobariz

Graduate Theses and Dissertations

This dissertation evaluates the effects of three development interventions on female education in Afghanistan: 1) effects of foreign military withdrawal on females’ demand for higher education; 2) impacts of PEZAK, a community-driven university entrance preparation, on student enrollment and performance in tertiary education; and 3) long-term effects of National Solidarity Program (NSP), that established gender-balanced local development councils, on female enrollment. Foreign military withdrawal increased female participation in higher education by 0.3 percentage points from a base value of 0.05 percent participation per capita. The PEZAK increased test scores by 0.17 standard deviations and had a positiveeffect on enrollment in …

Weakly Q-Convex Domains And Bounded Q-Subharmonic Exhaustion Functions, Emily Foss

Graduate Theses and Dissertations

We generalize the Diederich-Fornaess index to bounded weakly q-convex domains with bounded q-subharmonic exhaustion functions. Sufficient conditions for this generalized Diederich-Fornæss index to have a given lower bound are proved. We show this generalized index is positive on bounded weakly q-convex domains with C^3 boundaries. Additionally, we prove sufficient conditions for this generalized index to equal one. For example, we show that if the domain has Property ( ̃(Pq ) ) then the domain has high hyperconvexity.

An Evaluation Of The Convergent Construct Validity Of The Boldness Inventory Of Psychopathy Using A Five-Minute, 10% Carbon-Dioxide-Enriched Air Challenge, Morgan Alexandra Hill

Graduate Theses and Dissertations

Psychopathy is a constellation of maladaptive interpersonal, affective, and behavioral features, including grandiosity, manipulativeness, emotional detachment, and impulsivity (Hare, 2003). Fearlessness, immunity to stress, self-assurance, and social dominance are considered to be adaptive features of psychopathy. Patrick and colleagues (2009) sought to reconcile differences between opposing conceptualizations of psychopathy by formulating a triarchic model of the condition. One core construct in this model, boldness, captures an ability to remain calm in the face of threat, an appetite for dangerous or risky activities, and an increased tolerance for uncertainty and danger. Boldness is believed to originate from differences in the brain’s …

The Relationship Between Psychosocial Factors And Food Waste-Related Behaviors Among College Students, Kacy Raquel Wright

Graduate Theses and Dissertations

Food waste is a significant environmental, economic, and social issue, with younger consumers as the most significant contributors. Specific behaviors, like over-purchasing food and misusing date labels, result from a complex interaction between social and psychological factors, which influence food waste among this demographic. The purpose of this study was to identify the psychosocial factors influencing food waste behaviors among college students at the University of Arkansas. Guided by the Theory of Planned Behavior, this study utilized online and face-to-face quantitative surveys, distributed to students enrolled at the University of Arkansas in the spring of 2022. Demographics, attitudes, subjective norms, …

Structural Interpretation Of An Alkaline-Carbonatite Complex Using Gravity And Magnetic Methods At Magnet Cove, Arkansas, Chelsea Morgan Amaral

Graduate Theses and Dissertations

The Magnet Cove alkaline-carbonatite complex in the Ouachita Mountains of south-central Arkansas could be a valuable resource for rare earth elements, though it has not yet been thoroughly studied using geophysical methods, and existing geophysical models simplify its diverse nature. Prior to this study, the subsurface structure and extent of the Magnet Cove complex was poorly understood and, in general, the process of emplacement of alkaline carbonatite complexes worldwide is also not fully understood. The Magnet Cove complex hosts an extensive variety of rare rock types and mineral resources that contrast significantly to the sedimentary rocks into which they have …

Quantum Transport And Electric-Field Effects In Layered Topological Semimetals And Magnetic Materials, Arash Fereidouni Ghaleh Minab

Graduate Theses and Dissertations

This dissertation describes transport experiments on quantum devices in layered Dirac nodal line topological semimetals and antiferromagnetic materials down to a few layers. We used gate-induced effects to alter the transport properties of these materials.

First, we introduced current annealing in topological semimetals to achieve high-quality devices. We demonstrate current annealing to substantially improve the electronic transport properties of 2D topological semimetal flakes. Contact resistance and resistivity were improved by factors up to 2,000,000 and 20,000, respectively, in devices based on exfoliated flakes of two topological semimetals, ZrSiSe and BaMnSb2. Using this method, carrier mobility in ZrSiSe improved by a …

The Cosmic History Of X-Ray Binary Evolution, Woodrow Gilbertson

Graduate Theses and Dissertations

The Chandra Deep Fields provide an extraordinary window into the high-energy history of the cosmos. Observations of non-active galaxies within the deep fields can be leveraged to extract information about the formation and evolution of X-ray binaries (XRBs). Previous studies have suggested that the evolution of XRB luminosity can be expressed a function of physical parameters such as star formation rate, stellar mass, stellar age, and metallicity. The goal of this work is to develop and implement a complete physical parameterization for the luminosity of XRB populations, which can be utilized for a variety of further studies.

Chapter 1 provides …

Evaluation Of Carbon Isotopic Chemostratigraphy Of The Cedar Mountain Formation Of Utah, Clayton Forster

Graduate Theses and Dissertations

The Lower Cretaceous rocks of Utah preserve the origin of a multitude of dinosaur taxa, spread of angiosperms on the North American continent, and evolution of marsupial and eutherian mammals. However, the timing of deposition of these rocks is not well understood and must be determined to understand climatic controls on these biological events. Estimates of the age of the Cedar Mountain Formation and its constituent members range from Late Jurassic to early Late Cretaceous. Understanding the timing of deposition of the Cedar Mountain Formation is critical to dinosaurian and associated taxa studies as well as paleoclimate reconstructions from within …

Understanding Martian Salts And Their Implications For Liquid Water, Rachel Slank

Graduate Theses and Dissertations

Water is one of the key components for life as we know it. The existence of salts on Mars has been a large contributing factor to the possibility of habitability, due to their ability to allow liquid water to remain stable at colder temperatures. Salts, including perchlorates, chlorates, and chlorides, have been detected by multiple landers, rovers, and orbiters, and are now believed to be ubiquitous on Mars. One of the pathways to liquid brine solutions is through deliquescence. Deliquescence is the transition from a solid salt crystal into an aqueous solution when exposed to a humid atmosphere. This research …

Study Of Thermoelectric And Lattice Dynamics Properties Of 2d Layered Mx (M = Sn, Pb; X = S, Se, Te) And Zrs2 Compounds Using First-Principles Approach, Abhiyan Pandit

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of thermoelectric and lattice dynamics properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Se, Te) and ZrS2 compounds based on the first-principles density functional theory. The dimensionality reduction (e.g., using 2D structure) of bulk materials is found to have enhanced thermoelectric efficiency. This enhancement is attributed to the increase of the Seebeck coefficient as a result of higher electronic density of states near the Fermi level in low-dimensional materials. In addition, lowering the dimensionality increases phonon scattering near interfaces and surfaces in 2D materials, which leads to a …

Modeling The Impact And Accelerating The Process Of Transitioning To A Sustainable Healthy Diet Through Decision Support Systems, Prince Agyemang

Graduate Theses and Dissertations

Food production and consumption are essential in human existence, yet they are implicated in the high occurrences of preventable chronic diseases and environmental degradation. Although healthy food may not necessarily be sustainable and vice versa, there is an opportunity to make our food both healthy and sustainable. Attempts have been made to conceptualize how sustainable healthy food may be produced and consumed; however, available data suggest a rise in the prevalence of health-related and negative environmental consequences of our food supply. Thus, the transition from conceptual frameworks to implementing these concepts has not always been effective. This paper explores the …

Materials Design For Energy Applications Using Ab- Initio Calculations, Hind Hemaidee Alqurashi

Graduate Theses and Dissertations

The structural, dynamical, electronic, and thermoelectric properties of rock-salt and wurtzite Cd1-xZnxO alloys, VTiRhZ (Al, Ga, In, Si, Ge, Sn) and ZrTiRhZ (Ge, Sn) quaternary Heusler alloys (QHAs) were investigated using density functional theory (DFT) and semi-classical Boltzmann transport theory. From these calculations, the alloys were identified as potential materials for future thermoelectric applications. Furthermore, the magnetic and spin-polarization properties of these QHAs were investigated. The total magnetic moments were found to be integer values for all QHAs. In addition, all studied QHAs except VTiRhAl possess a half-metallic behavior with a 100% spin-polarization. The half-metallic ferromagnetic behavior makes them promising …

Application Of Microwave-Assisted Technology For Single-Pass Drying Of Rough Rice, Rebecca Mawusi Bruce

Graduate Theses and Dissertations

The 915 MHz industrial microwave is a novel technology that has the potential to achieve one-pass drying of rice within a short drying duration and reduce rice drying losses. However, processing recommendations for the commercialization of this technology for rice drying is lacking. The goal of this research is to provide processing conditions that are useful for the commercialization of the 915 MHz industrial microwave technology for rice drying. This was achieved by studying the impact of microwave specific energy and processing conditions such as harvest moisture content, milling duration, and aging on the physicochemical properties of a 915 MHz …

Hostages Of The Crisis: Iranian Students And Jimmy Carter, Timothy Will Teague

Graduate Theses and Dissertations

Hostages of the Crisis: Iranian Students and Jimmy Carter discusses President Carter’s decision in 1979 to order the Immigration and Naturalization Service to assess the approximately 56,000 Iranian students in the United States for deportation after the seizure of the American embassy in Tehran, Iran. This works begins with a discussion of the development of the nation’s immigration system, examining how it was born as a result of anti-Chinese xenophobia in the late nineteenth century and how it matured with nativistic immigration laws in the first half of the twentieth century. Immigration policy was often influenced by xenophobic sociopolitical pressure …

Allelopathic Effect Of Cereal Straw Extracts On Growth Of Raphidocelis Subcapitata And Microcystis Aeruginosa, Holly Wren

Graduate Theses and Dissertations

Harmful algal blooms are increasing in size, duration, and intensity around the globe. For several decades, cereal straws have been recognized as a viable algal control method, though the mechanisms by which cereal straws inhibit algae remain a topic of research. The objectives of this study were to evaluate the effectiveness of decomposing cereal straw extract, particularly rice (Oryza sativa) and barley (Hordeum vulgare) straw extract, to inhibit the green alga Raphidocelis subcapitata or cyanobacteria Microcystis aeruginosa in bioassays and to determine if the effectiveness of decomposing rice straw extract is altered by the presence of natural organic matter or …

Chondronecrosis With Osteomyelitis In Broilers: Bacterial Species Involvement And Influence Of Probiotics And Synbiotics, Amer Abdullah Hasan

Graduate Theses and Dissertations

Since 1945, the market for broiler production has evolved from a collection of smallholder poultry farms into an industry worth billions of dollars. Poultry production has not gone without challenges. Lameness in young broilers is presently a serious issue in the poultry industry for reasons of animal health and welfare, as well as significant lost production and revenue. Bacterial chondronecrosis with osteomyelitis (BCO) is a major form of lameness in broilers. This dissertation contains information about (i) the influence of Staphylococcus agnetis, Staphylococcus saprophyticus, Staphylococcus epidermidis and Enterococcus faecalis on inducing BCO lameness, (ii) evaluation of of probiotics for reducing …

The Effects Of Side-Channel Attacks On Post-Quantum Cryptography: Influencing Frodokem Key Generation Using The Rowhammer Exploit, Michael Jacob Fahr

Graduate Theses and Dissertations

Modern cryptographic algorithms such as AES and RSA are effectively used for securing data transmission. However, advancements in quantum computing pose a threat to modern cryptography algorithms due to the potential of solving hard mathematical problems faster than conventional computers. Thus, to prepare for quantum computing, NIST has started a competition to standardize quantum-resistant public-key cryptography algorithms. These algorithms are evaluated for strong theoretical security and run-time performance. NIST is in the third round of the competition, and the focus has shifted to analyzing the vulnerabilities to side-channel attacks. One algorithm that has gained notice is the Round 3 alternate …