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Characterizing Hydrothermal System Groundwater Dynamics Using Conservative And Non-Conservative Tracers: Insights And Implications Drawn From Study At The Taupo Volcanic Zone (New Zealand) And Valles Caldera (Usa), Joshua Michael Blackstock

Graduate Theses and Dissertations

Hydrothermal systems constitute an important component of heat and mass transport within Earth’s crust having direct and indirect impacts to society. Investigating contemporary hydrochemical differences and change are critical to evaluating and deconvolving factors that influence geothermal systems through time. In this dissertation, groundwater mixing approaches were used to study hydrochemical differences in two globally significant hydrothermal areas, which included fabrication of a low-cost dissolved CO2 monitoring for dissolved inorganic carbon (DIC). In the Taupo Volcanic Zone (New Zealand), empirical spatial relations were used to derive low-temperature groundwater end-members of Cl and Cl/Br for end-member mixing analysis (EMMA). Using EMMA, …

Studies On Pathogenesis Of The Diseases Caused By Macrophomina Phaseolina And Phomopsis Longicolla On Soybean, Marcio Leizer Zaccaron

Graduate Theses and Dissertations

Soybean (Glycine max), a legume, is an economically important crop in many parts of the world, including the USA, Brazil, Argentina, China, and India, currently the top five producing countries. Soybean is primarily used as feed, with incising markets for food and biodiesel. Similar to most crops, soybean yield and quality are affected by a diverse group of plant pathogens. In particular, several species of filamentous fungi have been the cause of severe yield losses in most growing regions world-wide. The soil born fungus Macrophomina phaseolina, causal agent of charcoal rot, has been found to be endemic to several soybean …

Microextrusion 3d Printing Of Optical Waveguides And Microheaters, Edidiong Nseowo Udofia

Graduate Theses and Dissertations

The drive for smaller and more compact devices presents several challenges in materials and fabrication strategies. Although photolithography is a well-developed method for creating microdevices, the disparate requirements in fabrication strategies, material choices, equipment and process complexities have limited its applications. Microextrusion printing (μEP) provides a promising alternative for microfabrication. Compared to the traditional techniques, the attractions lie in the wide range of printable material choice, greater design freedom, fewer processing steps, lower cost for customized production, and the plurality of compatible substrates. However, while extrusion-based 3D printing processes have been successfully applied at the macroscale, this seeming simplicity belies …

The Archaeology Of Mississippian Vulnerability And Resilience In The New Madrid Seismic Zone, Michelle Megan Rathgaber

Graduate Theses and Dissertations

This work examines the vulnerability and resilience of Mississippian people in the Central Mississippi Valley to the large-scale New Madrid seismic zone earthquakes of the late15th to early 16th century. This is done using the theory of eventful archaeology/anthropology to look at cultural materials both before and after an event (such as an earthquake and sand blows) to look for evidence of changes to the schema and resources on which a society relies. If changes are present, the event can be labeled as such, if there are no changes, it means that the society affected did not see the event …

Emotion Identification And Beliefs About Emotions As Mediators Of Ptsd And Parenting Meta-Emotion Philosophies, Maegan Calvert

Graduate Theses and Dissertations

Approximately 20% of women are sexually victimized and incarcerated women’s rates of victimization are much higher. In addition, women have a higher rate of PTSD and trauma-related sequelae than men. Interpersonal trauma experiences can have a negative impact on emotional processes such as alexithymia, recognizing others’ emotions, and healthy beliefs about emotional experiences. These difficulties are associated with problematic parenting. However, the mediational processes by which PTSD and disruptive emotional processes affect parenting is unclear. The current study examines the associations among PTSD, alexithymia, negative beliefs about emotions, emotion recognition in children, and parenting meta-emotion philosophies in incarcerated women presenting …

The Functional And Structural Analysis Of Drosophila Robo2 In Axon Guidance, Lafreda Janae Howard

Graduate Theses and Dissertations

In animals with complex nervous systems such as mammals and insects, signaling pathways are responsible for guiding axons to their appropriate synaptic targets. Importantly, when this process is not successful during the development of an organism, outcomes include catastrophes such as human neurological diseases and disorders. It is vital to determine the underlying causes of such diseases by understanding the development of the nervous system. There are many pathways that have been identified to play a role in this, however, we lack an understanding of how these pathways can promote such diverse outcomes in different populations of neurons. These pathways …

Understanding The Molecular Strategies Of Campylobacter Jejuni For Survival In Amoeba And Chicken., Deepti Pranay Samarth

Graduate Theses and Dissertations

Campylobacter jejuni endure to be major cause of gastroenteritis in humans worldwide. C. jejuni is fastidious in laboratory setup but can cause waterborne infection through contaminated water where none of these fastidious conditions are met. This dissertation presents an assortment of studies focused in reviewing three major factors which could present a helping hand to C. jejuni in its environmental survival viz. i) association with free-living amoebae (FLA) ii) horizontal gene transfer (HGT) contributing towards its genetic diversity iii). Viable but non-culturable (VBNC) state.

Acanthamoeba is a FLA linked to environmental survival of many intracellular pathogens, including C. jejuni. In …

Impact Of Excitation-Inhibition Balance/Imbalance On Dynamics Of Cortical Neural Networks, Vidit Agrawal

Graduate Theses and Dissertations

The purpose of this research is to study the implications of Excitation/Inhibition balance and imbalance on the dynamics of ongoing (spontaneous) neural activity in the cerebral cortex region of the brain.

The first research work addresses the question that why among the continuum of Excitation-Inhibition balance configurations, particular configuration should be favored? We calculate the entropy of neural network dynamics by studying an analytically tractable network of binary neurons. Our main result from this work is that the entropy maximizes at regime which is neither excitation-dominant nor inhibition-dominant but at the boundary of both. Along this boundary we see there …

Impact Of Sanitizers On Salmonella Enterica Contamination And Microbial Populations Of Poultry Processing Reuse Water, Andrew Micciche

Graduate Theses and Dissertations

As human populations increase in numbers, access to clean, fresh water is becoming increasingly difficult to balance between agricultural and municipal demands. Water scarcity is a limiting factor of food production in many countries, whether they are emerging or established economies. In conventional poultry processing systems, access to water is particularly critical for the maintenance and disinfection of processing areas, as well as in processing operations such as scalding, chilling, and carcass washing. The need for sustainable alternatives to single-use water supplies is becoming increasingly more urgent, and as a result, the implementation of water reuse in poultry processing plants …

Selectivity Of Infrared Heat Treatment On Inactivation Of Mycotoxigenic Fungi On Stored Grain, Shantae A. Wilson

Graduate Theses and Dissertations

Selective Infrared (IR) heating holds great potential to decontaminate spores of unsafe fungi in corn. The objectives for this study were to investigate the impact of exposing corn to infrared energy at selected peak wavelengths (λ), infrared intensities and treatment durations, followed by tempering for further inactivation of microbes on the grain and explore a method for decontaminating Aspergillus flavus (A. flavus) spores on corn. Freshly harvested corn with initial moisture contents (IMCs) of 16%, 20%, and 24% wet basis (w.b.) were used. The corn samples were treated at different infrared wavelengths (3.2, 4.5, and 5.8 μm) for 20, 40 …

The Effect Of Prescribed Burning On Wood-Decay Fungi In The Forests Of Northwest Arkansas, Nawaf Ibrahim Alshammari

Graduate Theses and Dissertations

Prescribed burning is defined as the process of the planned application of fire to a predetermined area under specific environmental conditions in order to achieve a desired outcome such as land management. This project used both morphological and molecular methods to identify and characterize the wood-decay fungi associated with the forests of northwest Arkansas—Pea Ridge National Military Park, Devil’s Den State Park, and the Buffalo National River—through frequent visits made between February 2018 and February 2019. In addition, in order to assess the effects of prescribed burning, incubation chambers were used to compare the growth of fungi from both unburned …

Footprints Of Resilience: Tracking The Career Development Steps Of African American Male Musicians, Patrice Tiffany Leshay Bax

Graduate Theses and Dissertations

For African American (AA) male musicians, the road toward career advancement in the entertainment industry is particularly arduous. Despite many difficulties on the journey to career success, the history of gospel, R&B, jazz, and funk music is evidence that many AA male musicians find their way to develop and advance their careers. Many AA male musicians find career development and advancement opportunities through religious and sacred institutions. However, the journey to become a professional musician for AA males is fluid and not formalized causing ambiguity in the steps taken to enter this career field and sustain growth in a rapidly …

Older Adults’ Expectations, And Knowledge Of Oral Health Issues: A Study Of Arkansas Seniors, Virginia Marie Hardgraves

Graduate Theses and Dissertations

The life expectancy of the U. S. population is increasing. The advantages of fluoridated water, dental insurance, greater awareness of preventive oral healthcare measures, and more restorative dental services, have helped this generation of adults maintain their teeth into their advanced years. The demand for oral health care services will be greater and more complex that of previous generations. Challenges for the older adult, and the healthcare system providing for them, are complex. Increasing evidence of a link between oral health and overall health underscores the need to promote public health awareness of the need for dental care to be …

Emerging Adult Career Pathways: Understanding Aspirations And Switching, Tasmiah Amreen

Graduate Theses and Dissertations

Emerging adulthood is a stage of life characterized by a high degree of fluctuation in identity formation and future decision-making (Arnett 2015). During this life stage, emerging adults make decisions about their future career by assessing whether they want to continue with their current career pathway or whether they intend to switch. The present study investigates this process in terms of its overall prevalence – or how often emerging adults intend to switch career trajectories – and the correlates of it. Previous studies on career switching have focused largely on educational switches. This quantitative study operationalizes career pathway by using …

Preliminary Outcomes, Acceptability, And Feasibility Of A Brief Crisis Response Planning Intervention For Reducing Suicide Risk In Primary Care Behavioral Health Patients, Aubrey R. Dueweke

Graduate Theses and Dissertations

Primary care is an important setting for improving identification and treatment of people at risk for suicide. However, there are few developed protocols for management of suicide risk in this setting. This study aimed to evaluate the preliminary outcomes, acceptability, and feasibility of a brief crisis response planning intervention for patients at a moderate risk for suicide in a primary care behavioral health (PCBH) setting. The outcomes examined included change in suicidal cognitions, suicidal intent, hope, and coping efficacy. Twenty-two adult primary care patients at moderate risk for suicide participated in this study, which involved filling out self-report measures before …

The South African Women's Movement: The Roles Of Feminism And Multiracial Cooperation In The Struggle For Women's Rights, Amber Michelle Lenser

Graduate Theses and Dissertations

In the historiography of South Africa’s recent past, focus has been most heavily placed on apartheid and the anti-apartheid movement, with much emphasis placed on male involvement and men as the primary agents of change in the country. Women are largely viewed as playing a supportive role to male activists throughout the movement, and far less has been written on female involvement or women’s activism in its own right. Running parallel to the anti-apartheid movement, however, was a women’s movement characterized by women across the racial and socioeconomic spectrum struggling to secure their own rights in a very hostile and …

Stable Isotope And Geochemical Characterization Of Nutrient Sources In The Big Creek Watershed Of Northwest Arkansas, Kelly Robin Sokolosky

Graduate Theses and Dissertations

The establishment of a concentrated animal-feeding operation (CAFO) in Newton County, Arkansas near Big Creek, a tributary of the Buffalo National River, has raised concern over potential degradation of water-quality in the watershed. In this study, isotopic tools were combined with standard geochemical approaches to characterize nutrient sources and dynamics in Big Creek. An isotopic and geochemical reference library of potential nutrient sources in the Big Creek watershed was established by direct sampling of representative potential sources, including septic-system effluent, poultry litter, swine and cattle manure, and CAFO waste lagoons. Representative nutrient sources and Big Creek stream samples were analyzed …

Potential Antimicrobials For Controlling Listeria Monocytogenes In Frankfurters, Aaron Rashad Bodie

Graduate Theses and Dissertations

Listeria monocytogenes is a pathogenic microorganism that causes Listeriosis. Listeriosis is a highly mortal disease with approximately 20% mortality rate. Listeria is psychrophilic, therefore it is able to survive in the refrigerator. This affects foods at cool storage such as fresh produce and RTE meats. To ensure the safety of RTE meat, post processing treatments are used such as vacuum packing, edible films, dip and treatment. One-way RTE can be treated is with the use of antimicrobials. However, in the past chemical substances were used. Currently, consumers want more natural and organic preservatives to combat health problems from toxic components …

Influences Of Autism Spectrum Disorder On Sensory And Emotional Responses To Smell And Taste Cues, Asmita Singh

Graduate Theses and Dissertations

Autism spectrum disorder (ASD) is a developmental disability that causes social, communication, behavioral and sensory challenges. The prevalence has been on a rise, with the latest reports stating 1 in 59 children is diagnosed with ASD. These challenges play a significant role in feeding behavior, leading to reduced nutrition among individuals. Much research in this field has been attributed to children, however, this study was focused on the adult population, in an attempt to improve their quality of life. Building on previous findings and knowledge gaps, the objectives of this thesis were two-fold: To better understand the sensory experiences of …

Nesting Success Of Dickcissel (Spiza Americana) And Non-Breeding Grassland Bird Use Of Northwest Arkansas’ Remnant And Restored Tallgrass Prairies, Alyssa L. Derubeis

Graduate Theses and Dissertations

Dwindling populations of North American grassland birds are linked to habitat loss. Tallgrass prairie only covers 3% of its pre-settlement-era range. Small-scale restoration projects attempt to increase acreage for prairie avifauna, and while some breeding grassland species are present at these sites, nesting success and non-breeding use are still largely unknown. Both life history aspects are required for effective grassland bird conservation. My first objective was to access nest success of the Dickcissel (Spiza americana) at two remnant and two restored tallgrass prairies in Northwest Arkansas. From May-August 2017 and 2018, I found 114 nests that I monitored to determine …

A Study Of Protein And Peptide-Directed Nanoparticle Synthesis For Catalytic Materials, Abdollah Mosleh

Graduate Theses and Dissertations

Nanoparticles have received much attentions due to their unique properties that makes them suitable candidates for a broad range of applications. As the size of particles decreases, their surface area-to-volume ratio would increase which is the main cause of much attention. In addition to the size, their morphologies and compositions may also play important roles for defining unique properties. Nanoparticle synthesis include both bottom-up and top-down strategies. To control the process of inorganic nanoparticles synthesis one could follow the bottom-up approach to have atom-level control over their compositions, morphologies, phases, and sizes which is the subject of this work. Due …

Bioengineering Extracellular Matrix Scaffolds For Volumetric Muscle Loss, Kevin Roberts

Graduate Theses and Dissertations

Volumetric muscle loss overwhelms skeletal muscle’s ordinarily capable regenerative machinery, resulting in fibrosis and severe functional deficits which have defied clinical repair strategies. My work spans the design and preclinical evaluation of implants intended to drive the cell community of injured muscle toward a regenerative state, as well as the development of an understanding of the molecular responses of this cell community to biomaterial interventions. I demonstrate a new class of biomaterial by leveraging the productive capacity of sacrificial hollow fiber membrane cell culture; I show specifically that unique threads of whole extracellular matrix can be isolated by solvent degradation …

Gender In Apocalyptic California: The Ecological Frontier, Marykate Eileen Messimer

Graduate Theses and Dissertations

Climate change is the consequence of ideologies that promote human reproduction and resource consumption by sacrificing human justice, nonhuman species, and the land. Both biology and queer ecologies resist this notion of human separation and supremacy by showing that no body is a singular, impermeable entity, that all beings are biologically and inexorably connected. My dissertation demonstrates that fiction writers use this knowledge to locate a utopian vision that can counteract the dystopian impotence of living within climate change. This argument is founded on novels written by women and set in California, a state that uniquely inhabits a utopian and …

Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim

Graduate Theses and Dissertations

Volumetric muscle loss (VML) is a traumatic injury in skeletal muscle resulting in the bulk loss of more than 20% of the muscle’s volume. Included in the bulk loss of muscle is the skeletal muscle niche comprised of nerve bundles, vasculature, local progenitor cells, basal lamina, and muscle fibers, overwhelming innate repair mechanisms. The hallmark of VML injury is the excessive accumulation of non-contractile, fibrotic tissue and permanent functional deficits. Though predominant in the younger demographic, the elderly population is also captured within VML injuries. There are many factors that change with aging in skeletal muscle that may further hinder …

Representations Of Domestic Workers In Modern Arabic Fiction, Samaher Aldhamen

Graduate Theses and Dissertations

In this study, I have examined the representations of domestic workers in a number of Arabic mid-century and contemporary novels, using feminism and intersectionality as my overarching framework. I employed several scholarships of feminism such as Marxist and postcolonial feminism to examine the discourse on working-class women. The initial assumption of this study is that there is a noticeable invisibility of domestic workers in Arabic novels. If these characters manage to find their way into a text, they are typically ahistorical figures whose subjectivity is not centered.

Among the Arabic novels I have examined, I found that the tradition of …

The Impact Of Mother And Adolescent Offspring Distress Reduction Training On Maternal Anxiety And Alcohol Related Behaviors Following Conflict, Sarah Ann Bilsky

Graduate Theses and Dissertations

Nearly half of people suffering from psychopathology meet criteria for more than one disorder. Scholars have focused on understanding factors that may simultaneously maintain multiple psychiatric problems. Elevated distress during interpersonal conflict is likely to maintain both alcohol use and anxiety psychopathology. Reducing distress elicited by normative mother-adolescent conflict holds particular promise. Conflict is common in families with problematic drinking and anxiety disorders and the affective impact of parent-offspring conflict is malleable. Distress reduction skills, such as cognitive reappraisal, are effective in reducing distress during conflict. The current study examined the unique and combined effects of training mothers and adolescents …

Remembering How To Listen: A Theoretical And Pedagogical Approach To Literacy, Adolescence, And Young Adult Literature, Stuart A. Morris

Graduate Theses and Dissertations

There is a substantial and growing body of critical theory on young adult literature (YAL), and there are a multitude of publications dealing with how secondary English/ELA teachers incorporate YAL in their classroom. From a curricular perspective, however, YAL is still most often considered inferior to canonical novels (i.e., “classics” or “great books”); thus, there has been no substantive or concerted movement to include YAL in secondary English/ELA at a curricular level, particularly in grades ten, eleven, and twelve. While the scholarship on YAL is extensive, discussion of YAL is most often devoted to pedagogy or literary theory, as if …

Effects Of Germination Conditions Of Brown Rice In Relation To Flour Physicochemical Properties And Bread Qualities, Wipada Wunthunyarat

Graduate Theses and Dissertations

Gluten-free products from rice are gaining popularity among consumers because of its hypoallergenic characteristic. The absence of gluten results in inferior bread qualities such as hard texture, reduced volume and shorter shelf-life, which can be improved by the addition of external hydrolytic enzymes. Hydrolytic enzymes are activated during germination to stimulate plant growth, and hence these enzymes may function similarly to the external enzymes to improve gluten-free bread from brown rice. Therefore, the objective of this work was to investigate the activities of amylases and protease in germinated brown rice (GBR) from long-grain and short-grain rices under different germination conditions …

Visualizing Ischemic Skin Flap Necrosis Through Phasor Analysis Of Autofluorescence Lifetime Images, Hallie Ramser Toomer

Graduate Theses and Dissertations

Necrotic skin flaps are difficult to predict and treat due to the lack of quantitative biomarkers. Label-free multiphoton microscopy is well suited for non-invasively monitoring skin metabolism through NAD(P)H and other intrinsic fluorophores, and offers immediate future directions for assessing necrosis in the clinic. The objective of this study was to assess whether phasor FLIM could be used to evaluate skin flap status and treatment efficacy in ex vivo skin sections. Phasor maps revealed differences in growth factor treatment and region, but changes in skin flap autofluorescence at 755nm excitation and 460nm emission were not just related to NAD(P)H. A …

Adsorption Driven Regolith-Atmospheric Water Vapor Transfer On Mars: An Analysis Of Phoenix Tecp Data, Holly Nicole Farris

Graduate Theses and Dissertations

NASA’s Phoenix mission allowed for investigations of Martian diurnal water vapor cycles through the collection of temperature, relative humidity, and electric conductivity data by the Thermal and Electric Conductivity Probe (TECP) instrument. Using this data and previous experimental data, we propose a regolith-driven adsorption-desorption regime at the Phoenix landing site, where parameters intrinsic to the regolith are controlling localized relative humidity at the surface. To constrain these parameters, we model adsorption as a function of temperature and relative humidity across various Mars-relevant materials, defined by two layer-based adsorption theories: Langmuir (monolayer) and Brunauer-Emmett-Teller or BET (multilayer). Langmuir serves as an …