Digital Commons Network^™

Solvent As A Tool To Tune The Association Of Structured Ionic Block Co-Polymers: Neutron Scattering And Computational Study, Manjula Senanayake

All Dissertations

The work probes the behavior of associating polymers including their assembly in different environments, using neutron scattering techniques coupled with molecular dynamics (MD) simulations. Polymers interact with their surroundings through van der Waals forces and through stronger association groups such as ionizable groups and p-p stacking, as well as specific chemical binding, where assembly depends on the strength of the interactions of the associating groups as well as the interactions of the polymers with their solvent environment. The current effort centers on understanding the assembly of structured polymers that consists of multiple blocks or components, each with their distinct interactions …

Statistical Models For The Analysis Of Complex Data, Stefani Mokalled

All Dissertations

This dissertation focuses on developing statistical models to analyze complex data. The motivating applications in this work include infectious disease screening, engineering, and public health problems. Chapters 2 and 3 take a frequentist approach to modeling and parameter estimation while Chapters 4 and 5 proceed with Bayesian methods. Maximum likelihood estimation is implemented in a case of missing data through latent variables (Chapter 2) as well as by embedding a finite element model within the likelihood framework (Chapter 3). Two Markov Chain Monte Carlo (MCMC) algorithms are applied to estimate parameters and fit regression models using data obtained from a …

Encystation And Glycogen Metabolism In Entamoeba Histolytica, Jordan Lynne Wesel

All Dissertations

Entamoeba histolytica is a parasitic protozoan that causes amebic dysentery, which affects approximately 90 million people annually, killing between 50-100,000. E. histolytica is transmitted via the oral-fecal route, through ingestion of contaminated food and water. The infectious form of the disease is the quiescent cyst, which after ingestion, undergoes excystation in the small intestine to the proliferative trophozoite. The trophozoite is the disease-causing form of the parasite, which colonizes the large intestine. Some trophozoites encyst in the large intestine and are passed out of the host, propagating the infectious cycle.

Despite the global burden of this disease, study of the …

From The Womb To The Word: Pregnancy And Pregnancy Metaphors In 16th And 17th Century English Literature, Kelly S. Westeen

Graduate Theses and Dissertations

This dissertation employs a feminist theoretical lens in exploring the gendered uses of pregnancy and pregnancy metaphors in the production and dissemination of literary works in early modern England. By also examining the history of the printing press and the role it played in gendered textual production, early modern constructs of family and the role of mothers, as well as obstetric medicine and childbirth, I aim to demonstrate that mothering and authorship were congruent activities for female writers. Conversely, I argue that male writers of the period who employed metaphors of gestation did so not to try to claim biological …

Employee Engagement As A Shared Responsibility: A Study Of Engagement Strategies Employed By Legal Assistants, Thomas A. Steele

Graduate Theses and Dissertations

The purpose of this study was to identify strategies used by legal assistants to engage, stay engaged, and reengage, when appropriate, in their work, in particular when common organizational efforts fall short or do not exist. Constructivism and job demands-resources (JD-R) were the primary frameworks for understanding and analyzing the phenomenon of developing engagement strategies.

Qualitative data were drawn through semi-structured interviews with 16 legal assistants. The interviews were recorded and transcribed. Trustworthiness and validity were enhanced by using multiple respondents and allowing each to review the transcripts for accuracy, fairness, and clarity. The transcriptions were then analyzed for themes. …

Examining Pathogenesis And Preventatives In Spontaneous And Staphylococcus-Induced Bacterial Chondronecrosis With Osteomyelitis In Broilers, Nnamdi Simon Ekesi

Graduate Theses and Dissertations

Bacterial chondronecrosis with osteomyelitis is the most important cause of lameness in broilers. This is important to poultry production, as it poses animal welfare issues, and causes a significant loss in revenue. The remediation of this disease requires the study of its etiology with fitting models and evaluating preventatives. The research reported herein covers genomic virulence analysis of BCO isolates, mainly Staphylococcus aureus, and Escherichia coli retrieved from lame birds. We found that S. aureus isolates were closest to chicken strains in Europe but may have been in the Arkansas area for a decade. Phylogenomics suggest our S. aureus is …

Functional And Physiological Role Of Extra-Hypothalamic Corticotropin Releasing Hormone Neurons In The Nucleus Of The Hippocampal Commissure In Regulation Of Stress Response, Hakeem Kadhim

Graduate Theses and Dissertations

Corticotropin releasing hormone (CRH) neurons located within the paraventricular nucleus (PVN) are known to be involved in regulation of stress responses. Recently, CRH neurons were identified above the PVN within the nucleus of the hippocampal commissure (NHpC) that located in the septum. We hypothesized that CRH neurons in the NHpC play a critical role in the stress response due to their rapid activation and could be a part of the traditional hypothalamo-pituitary-adrenal (HPA) axis. The dissertation addresses the role of 1) CRH expressing neurons in the NHpC compared with those within the PVN utilizing two different stressors, food deprivation (FD) …

Investigation Of Electrospun Nanofibers For Separation Applications, Shu-Ting Chen

Graduate Theses and Dissertations

Electrospun membranes are an attractive alternative to flat sheet membranes as absorbent with numerous advantages like high porosity, large specific surface area and ease of functionalization. This doctoral dissertation focuses on fabricating novel polymeric membrane adsorbents for protein separations and ammonium ion removal. Three distinctly different preparation methods including UV-initiated polymerization, atom transfer radical polymerization, and mixed-matrix formation, have been employed to fabricate the electrospun membranes. Overall, this study aimed to develop electrospun membranes with excellent separation efficiency for application in protein purification and ammonium ion removal.

Chapter 2 details the stepwise development of weak anion exchange membranes and subsequent …

The Effects Of Multiple Stressors On Stream Communities: The Convergence Of Drought, Nutrient Pollution, And Invasive Species, Robert Joseph Fournier Iii

Graduate Theses and Dissertations

Freshwater systems experience multi-faceted degradation from a variety of ecological and environmental stressors. Three common stressors in these systems, drought, nutrient pollution, and invasive species, have wide-ranging effects on stream population- community- and ecosystem dynamics. We have a broad understanding of how each of these stressors works to influence stream systems independently. However, we still know relatively little about if, and how, these stressors might interact when they co-occur. Though drought is a natural part of many stream systems, all three of these stressors can be exacerbated or facilitated by anthropogenic actions. Accordingly, as human population and resource use continue …

The Effect Of Epa And Dha On Skeletal Muscle Physiology And Energy Balance, Saeed Jebor Ghnaimawi

Graduate Theses and Dissertations

Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) supplementation commonly suggested during pregnancy confers many health benefits on offspring and more recently improves fetal BAT development and induces myoblast trans-differentiation into adiopocytes through activating PPARs expression. Embryonic myoblast is a highly flexible cell showing great capacity to change its phenotype into adipocyte in response to EPA and DHA supplementation in many in vitro models. However, a little is known about the identity of derived adipocytes, whether, they change into brown or white adipocyte, and in vivo evidence is still missing. Given that the myogeneis process is initiated at the mid of …

Effects Of Gatekeeper Course Modality, Age, Gender And High School Gpa On Kaplan Subject Area Exam Scores, Vernon Hoffman

Graduate Theses and Dissertations

The question of equivalency regarding course modality has plagued and intrigued educators for as long as multiple modalities have existed. In the modern world of academia, the two prevailing modalities are face-to-face or traditional courses and online courses. A multitude of factors have contributed to the increase in online course offerings, including increasingly dependable technology and fiscal pressures on institutions of higher learning.

A great deal of scholarly research has compared modalities using within-course measures such as course grades and comprehensive final exams. Most of these studies have found the two modalities equivalent. However, a dearth of research exists which …

Resistance To Herbicides Conferred By Amaranthus Palmeri Protoporphyrinogen Ix Oxidase Mutations, Pamela Carvalho De Lima

Graduate Theses and Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats.) is one of the most problematic agronomic weeds to control in fields across Arkansas. Thus far, this species has evolved resistance to several herbicides, including protoporphyrinogen IX oxidase (PPO) inhibitors. The majority of PPO-resistant Palmer amaranth populations harbor a target-site mutation (substitution or deletion of amino acids). The objective of this thesis was to identify the level of fomesafen resistance conferred by PPO2 mutations from Palmer amaranth. The experiments conducted aimed to (1) characterize the level of resistance conferred by the transgene Palmer amaranth ppo2 carrying ΔG210 mutation into the wild type rice (Oryza …

A Mixed-Methods Analysis Of Biofuels, Teresa Cristina Garcia

Graduate Theses and Dissertations

Brazil has the largest sugarcane acreage in the world (FAOSTAT, 2020) and is the world leader in the production of sugarcane-based ethanol (Sousa Junior et al., 2017). Due to the technical experience in the production of biofuels and the availability of sugarcane straw and bagasse, the country has a great potential to commercially produce second-generation ethanol (E2G) (Nyko et. al., 2010). In 2017, Brazil enacted a new National Biofuels Policy, called RenovaBio, to expand the production and use of biofuels in the country. This dissertation combines three essays that explore biofuels law and policy with a special focus on Brazil. …

Optimizing Immersive Technology Condition For Measuring Consumer Perception And Acceptance Of Food Products, Shady Afrin Jeesan

Graduate Theses and Dissertations

Rapid advancement of immersive technologies is paving the way toward a new era in sensory and consumer science by enabling consumers to experience tasting of food samples in different environments, thus generating more realistic perception. However, little attention has been paid to developing a standardized and optimized methodology for conducting such sensory testing in an immersive environment. A variety of factors related to sensory testing in an immersive environment may significantly modulate consumer perception and acceptance of foods. Therefore, this thesis study aimed to optimize protocols related to sensory testing using immersive technology. In this thesis study, participants were asked …

Multiphoton Microscopy And Deep Learning Neural Networks For The Automated Quantification Of In Vivo, Label-Free Optical Biomarkers Of Skin Wound Healing, Jake D. Jones

Graduate Theses and Dissertations

Non-healing ulcerative wounds that occur frequently in diseases such as diabetes are challenging to diagnose and treat due to numerous possible etiologies and the variable efficacy of wound care products. With advanced age, skin wound healing is often delayed, leaving elderly patients at high risk for developing these chronic injuries. As it is challenging to discriminate age-related delays from disease-related chronicity, there is a critical need to develop new quantitative biomarkers that are sensitive to wound status. Multiphoton microscopy (MPM) techniques are well-suited for 3D imaging of epithelia and are capable of non-invasively detecting metabolic cofactors (NADH and FAD) without …

Legislating Social Inclusion: Social Interaction And Perceptions Of Middle Level Students Toward Those With Disabilities, Deidre Necol Whitehead

Graduate Theses and Dissertations

Recognition of the need for students with disabilities to receive free and appropriate education was brought to the forefront with the passage of Public Law 93 – 112, Rehabilitation Act in 1973. In 1975 Public Law 94-142, the Education for All Handicapped Children Act was enacted requiring all schools to develop and provide a free, appropriate public education for all children and youth with disabilities in the regular classroom to ensure an appropriate education. However, mandating inclusion in classrooms does not ensure social interaction, which is an integral part of learning, especially for early adolescents.

This dissertation uses the Chedoke-McMaster …

Comparison Of A T-Trellis And A Rotating Cross-Arm Trellis For Arkansas Blackberry Production, Erika Henderson

Graduate Theses and Dissertations

As blackberry production in the southeastern United States expands, the need for updated cultural practices, like alternative trellis systems that enhance blackberry fruit yield, fruit quality, and economic viability for fresh-market growers are needed. There are challenges to producing high-quality blackberry fruit with high yields in the Southeast due to intense heat, high rainfall, humidity, and heavy pest pressure. Southeastern growers are interested in the rotating cross-arm (RCA) trellis due to its potential to increase yield and fruit quality, however there is minimal research of its use in blackberry production in the Southeast. In 2019 and 2020, a trial was …

Effects Of Long-Term Variation In Temperature On Reproductive Phenology In A Population Of Eastern Bluebirds (Sialia Sialis), Paul Pleiman

Graduate Theses and Dissertations

This study investigates the relationship between multiple temperature variables, to include annual and pre-lay date temperatures with first-egg and mean first-egg lay dates of the eastern bluebird at the Warner Parks in Nashville, Tennessee, USA. Data is collected by citizen scientists for the Eastern Bluebird Nesting Box Project while visiting artificial nest boxes throughout the park and recording observations made during the breeding season. Temperature data is retrieved from the Northwest Alliance for Computational Science and Engineering’s Parameter-elevation Regressions on Independent Slopes Model (PRISM) Climate Group, based at Oregon State University. The analyses showed no correlation between annual or pre-lay …

Optimization Of In-Vessel Food Waste Composting: Enzyme Activity And Microbial Dynamics, Ayawovi Selom Ametepe

Graduate Theses and Dissertations

A series of greenhouse-based, rotary-drum bioreactor experiments was designed to study microbial dynamics and enzyme activity during optimization of food waste composting. This work aims to optimize food waste composting by defining the best food waste-to-bulking agent proportion controlling conditions and by evaluating the food waste composting process when inoculated by a bacterial inoculant product compared to uninoculated compost. Three experiments were run in total. The two first experiments were conducted for 48 days with sampling at each step of composting, while the third experiment last 50 days and included one extra sampling date. In the first experiment, 50:50, 65:35 …

Fate And Dissemination Of Salmonella Reading In Market-Age Turkeys At Processing Using Oral Gavage Challenge Model, Aaron Ashcraft

Graduate Theses and Dissertations

This study aimed to evaluate the fate and dissemination of Salmonella Reading (SR) in market-age turkeys using an oral gavage challenge model. One hundred twenty-eight-week-old commercial turkey hens were moved from commercial production to research facilities. Upon arrival, a combination of enrofloxacin, 10 mg/kg, and florfenicol, 20 mg/kg, were orally administered sequentially before comingled placement on fresh pine shavings. Turkeys were challenged with 108 cfu SR by oral gavage on days 4 and 7 post-placement. Subsets were subjected to simulated commercial processing on days 14 (n=40), 21 (n=40) and 28 (n=32) post-placement (corresponding to 10, 11, and 12 weeks of …

Security Analysis Of Permission Re-Delegation Vulnerabilities In Android Apps, Biniam Fisseha Demissie, Mariano Ceccato, Lwin Khin Shar

Research Collection School Of Computing and Information Systems

The Android platform facilitates reuse of app functionalities by allowing an app to request an action from another app through inter-process communication mechanism. This feature is one of the reasons for the popularity of Android, but it also poses security risks to the end users because malicious, unprivileged apps could exploit this feature to make privileged apps perform privileged actions on behalf of them. In this paper, we investigate the hybrid use of program analysis, genetic algorithm based test generation, natural language processing, machine learning techniques for precise detection of permission re-delegation vulnerabilities in Android apps. Our approach first groups …

Student Discipline. The Construction And Use Of Warnings Concerning Past Behaviour, Timothy J. David, Ellen I. Schafheutle, Penny Mcconnell, Hannah Quirk

Health Professions Education

Purpose: Warnings are one of the basic methods for giving advice to students, yet there is a dearth of guidance and considerable variation and inconsistency in their content and application. Much of the associated terminology is confusing. To provide clarity, this paper examines the essential ingredients of warnings and their optimal construction and use in higher education, with a focus on students intending a career in one of the health and social care professions. Background: Currently warnings are often poorly designed and unclear. One example is giving a student a ‘yellow card warning’ without explaining what errors or omissions have …

Polerovirus Genomic Variation And Mechanisms Of Silencing Suppression By P0 Protein, Natalie M. Holste

School of Biological Sciences: Dissertations, Theses, and Student Research

The family Luteoviridae consists of three genera: Luteovirus, Enamovirus, and Polerovirus. The genus Polerovirus contains 32 virus species. All are transmitted by aphids and can infect a wide variety of crops from cereals and wheat to cucurbits and peppers. However, little is known about how this wide range of hosts and vectors developed. In poleroviruses, aphid transmission and virion formation is mediated by the coat protein read-through domain (CPRT) while silencing suppression and phloem limitation is mediated by Protein 0 (P0)—a protein unique to poleroviruses. P0 gives poleroviruses a great advantage amongst plant viruses and diversifies polerovirus species, but the …

Sensitive Periods For Psychosocial Risk In Childhood And Adolescence And Cardiometabolic Outcomes In Young Adulthood, Jenalee R. Doom, Kenia M. Rivera, Estela Blanco, Raquel Burrows, Paulina Correa-Burrows, Patricia L. East, Betsy Lozoff, Sheila Gahagan

Psychology: Faculty Scholarship

Greater psychosocial risk in childhood and adolescence predicts poorer cardiometabolic outcomes in adulthood. We assessed whether the timing of psychosocial risk from infancy through adolescence predicts cardiometabolic outcomes in young adulthood. Young adults and their mothers participated in a longitudinal study beginning in infancy in Santiago, Chile (N = 1040). At infancy, 5 years, 10 years, and adolescence, mothers reported on depressive symptoms, stressful experiences, support for child development in the home, father absence, parental education, and socioeconomic status (SES) to create a psychosocial risk composite at each time point. Young adults (52.1% female; 21–27 years) provided fasting serum samples …

Regulatory Challenges For Treating Failure To Disclose Fcoi As Research Misconduct In Public Health Research, Tammy M. Frisby

Utah Law Review

It is unlikely that a court would find that current HHS regulations provide legal authority for PHS funding-agencies to address “serious noncompliance” with FCOI disclosure requirements as research misconduct. With one exception—the culpability standard for research misconduct—the administrative law governing bias and integrity in PHS-funded research does not support treating even the most serious cases of failure to disclose FCOI in itself as research misconduct in violation of PHS regulations. Indeed, there are at least four features of that law which would support a claim that an HHS action to treat FCOI nondisclosure as research misconduct was “arbitrary and capricious.” …

Markovian Approach To Stock Price Modelling In The Nigerian Oil And Gas Sector, Ayo Adekunle S., Uwabor Eboigbe S.

CBN Journal of Applied Statistics (JAS)

The study investigates the stock price movement of quoted Nigerian oil and gas firms using the Markovian model. Specifically, the study estimates the change in likelihoods and steady-state distribution of the share prices of the firms to determine the average time spent by the share price to move to another state and the turnover rate of the selected stocks. Markov chain-based stochastic modelling approach was employed by using the daily closing share prices of all the seven oil and gas firms quoted on the Nigerian Stock Exchange from April 2017 to January 2020. The study finds that the transition probabilities …

Algorithms And Hardness Results For Computing Cores Of Markov Chains, Ali Ahmadi, Krishnendu Chatterjee, Amir Kafshdar Goharshady, Tobias Meggendorfer, Roodabeh Safavi, Dorde Zikelic

Research Collection School Of Computing and Information Systems

Given a Markov chain M = (V,v0,δ), with state space V and a starting state v0, and a probability threshold ϵ, an ϵ-core is a subset C of states that is left with probability at most ϵ. More formally, C ⊆V is an ϵ-core, iff P reach(V\C) ≤ ϵ. Cores have been applied in a wide variety of verification problems over Markov chains, Markov decision processes, and probabilistic programs, as a means of discarding uninteresting and low-probability parts of a probabilistic system and instead being able to focus on the states that are likely to be encountered in a real-world …

Deep Multi-Task Learning For Depression Detection And Prediction In Longitudinal Data, Guansong Pang, Ngoc Thien Anh Pham, Emma Baker, Rebecca Bentley, Anton Van Den Hengel

Research Collection School Of Computing and Information Systems

Depression is among the most prevalent mental disorders, affecting millions of people of all ages globally. Machine learning techniques have shown effective in enabling automated detection and prediction of depression for early intervention and treatment. However, they are challenged by the relative scarcity of instances of depression in the data. In this work we introduce a novel deep multi-task recurrent neural network to tackle this challenge, in which depression classification is jointly optimized with two auxiliary tasks, namely one-class metric learning and anomaly ranking. The auxiliary tasks introduce an inductive bias that improves the classification model's generalizability on small depression …

Associations Of Cannabis Use Disorder With Cognition, Brain Structure, And Brain Function In African Americans, Marinka M. G. Koenis, Joke Durnez, Amanda Rodrigue, Samuel R. Mathias, Aaron F. Alexander-Bloch, Jennifer Barrett, Gaelle E. Doucet, Sophia Frangou, Joanne E. Curran, John Blangero

School of Medicine Publications

Although previous studies have highlighted associations of cannabis use with cognition and brain morphometry, critical questions remain with regard to the association between cannabis use and brain structural and functional connectivity. In a cross-sectional community sample of 205 African Americans (age 18–70) we tested for associations of cannabis use disorder (CUD, n = 57) with multi-domain cognitive measures and structural, diffusion, and resting state brain-imaging phenotypes. Post hoc model evidence was computed with Bayes factors (BF) and posterior probabilities of association (PPA) to account for multiple testing. General cognitive functioning, verbal intelligence, verbal memory, working memory, and motor speed were …

Polymer-Based Capacitive Gas Sensor For Machine Olfaction, Mohamed Fathy Hassan

Theses and Dissertations

Transferring human abilities and knowledge to machines has been the focus of decades of work by scientists and engineers. With the progress in computation power and algorithms such as artificial neural networks, machines have surpassed humans in complicated games like chess and the Chinese game Go. Some senses can be mimicked including touch, with pressure sensors, hearing, with microphones, and vision with charged couple device (CCD)imaging chips. Yet, relatively little progress has been made with the senses of smell and taste. Machine olfaction, the ability to detect and quantify vapors in the environment, poses a range of challenges, which if …