Digital Commons Network^™

Listeria Monocytogenes Strain Variation: Starvation, Metabolism, And Macrophage Survival, Nathan A. Jarvis

Graduate Theses and Dissertations

Listeria spp. are often isolated from raw and processed food products. Listeria monocytogenes is responsible for death rates of 10 to 30% in immune compromised people; it can also infect a vast range of animals. There are numerous reports of poultry harboring or becoming infected with L. monocytogenes. First, this research assessed the ability of L. monocytogenes to replicate within chicken macrophages. Using the gentamicin-killing assay, a cell culture of chicken macrophage-like cells (HD11) were infected with two strains of L. monocytogenes individually (EGD-e and Scott A). Results show that unlike data on mouse macrophages, intracellular L. monocytogenes do not …

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …

Effect Of Hydration Status On Thermoregulatory Responses In Non-Obese And Obese Males, Matthew Tucker

Graduate Theses and Dissertations

During heat stress the human body thermoregulates via cutaneous vasodilation and sweating. Hypohydration can impair thermoregulatory responses that stem from the central nervous system (CNS), but it is unknown if impairments also occur post-synaptically in the microcirculation. Moreover, obese individuals may have impaired thermoregulation, possibly due to microvascular dysfunction. Purpose: The purpose of these studies was two-fold: 1) to determine if obese (OB) individuals exhibit impairments in thermoregulatory responses during exercise heat-stress (centrally-mediated) and intradermal infusion of vasoactive substances (peripherally-mediated) versus non-obese (N-OB), and 2) to determine if hypohydration subsequently affects these thermoregulatory responses differently between groups. Methods: Twenty-one healthy, …

Biocentrism In Environmental Ethics: Questions Of Inherent Worth, Etiology, And Teleofunctional Interests, David Lewis Rice Iii

Graduate Theses and Dissertations

Some biocentrists argue that all living things have "inherent worth". Anything that has inherent worth has interests that provide a reason for why all moral agents should care about it in and of itself. There are, however, some difficulties for biocentric individualist arguments which claim that all living things have inherent worth.

Some biocentrists maintain that all living things have inherent worth and that artificial living things do not because the former, but not the latter, have interests by recourse to their natural selection etiology. Some also argue that synthetic forms of life do not have moral standing because they …

Assessment Of The Level Of Protection Against Coccidiosis In Broiler Breeders Conferred By A Live Anticoccidial Vaccine, And Its Influence On Early Growth And Development., Muhammed Shameer Abdul Rasheed

Graduate Theses and Dissertations

Coccidiosis continues to be a great challenge to the poultry industry all over the world and in broiler breeders vaccination with live oocysts of Eimeria has been widely adopted as a control measure. Broiler breeders are usually subjected to feed restriction during their early growth however no studies have been undertaken on the effects of vaccination in birds whose feed has been restricted in this manner. The objective of this study was to assess the level of protection acquired by broiler breeder chickens when immunized at day-old with live eimerian oocysts and given a restricted diet. Effects upon growth and …

Identification Of Biomarkers Associated With Rous Sarcoma Virus-Induced Tumors In Two Divergently Selected Chicken Lines, Ashley Hayden

Graduate Theses and Dissertations

Poultry has become especially important to genetic research due to breeding feasibility, short generation turnover, and ease of maintaining large populations. The discovery of virus induced cancer has paved the way for further genetic studies. Rous Sarcoma Virus (RSV) is a tumor-causing virus that infects poultry. While not prevalent today, it can serve as a model for virus-induced cancer in humans and create additional insight to marker assisted selection in poultry. Genetically selected Arkansas Progressor (AP) and Arkansas Regressor (AR) chicken lines have been established and maintained at the Arkansas Experimental Station (AES) in Fayetteville, AR. Previous research has investigated …

It's Not The Load That Breaks You Down, It's The Way You Carry It: An Examination Of The Relationship Between Negative Identity And Consumer Behavior, Cassandra Denise Davis

Graduate Theses and Dissertations

Research examining Social identity and consumer behavior often centers on groups with positive Social identities, exploring the influence of similar identities (i.e., shared values, shared gender, shared political affiliations, shared ethnicity…etc.) or desired identities (e.g., sports celebrities, actors, and actresses). For example, research has shown that people display an increased attention to identity-based stimuli following the activation of a Socially distinct identity (Forehand, Deshpandé, and Reed 2002) and that heightening the self‐importance of a consumer Social identity leads to a preference for identity-related brands (Reed 2004). An important but often overlooked aspect of the influence of Social identity on consumption, …

Two Studies: Stereoselective C-C Bond Formations Of N-Boc-Piperidines Using Selected Organolithiums And Visible-Light-Mediated Synthesis Of Fused Indolines Using Tethered Styrenes, Scott Alan Morris

Graduate Theses and Dissertations

Chemists worldwide have accepted the challenge of developing methods to access a variety of compounds as single enantiomers, including the use of enzymes, chiral auxiliaries, and resolutions. In particular, dynamic resolutions offer a unique way to access chiral compounds using a few controllable steps, including the variation of both time and temperature. Many groups have implemented this methodology to generate various polysubstituted pyrrolidines and piperidines, which are substructures ranking high on the list of nitrogen–containing pharmaceuticals.

The Gawley group revealed a catalytic dynamic resolution (CDR) of N–Boc–piperidine using a chiral ligand. Impressively, the chemistry was tolerant of a variety of …

In Vitro Fermentation Patterns Of Rice Bran Components By Human Gut Microbiota, Tung Minh Pham

Graduate Theses and Dissertations

The prevalence of colorectal cancer (CRC) has been increasing in recent years worldwide. In the United States, it is ranked the second leading cause of cancer death. Risks of CRC increase with age and are associated with several lifestyle factors such as diet, drinking and smoking habits, and levels of physical activity. There is an abundance of scientific literature demonstrating the protective roles of several dietary components including fibers and polyphenolic compounds. These compounds have been shown to be able to positively modulate gastrointestinal ecology by increasing the production of short-chain fatty acids (SCFA) and promoting the population of beneficial …

Young Adult E-Cigarette Exposure: Implications For Policy And Prevention, Monica Page Daniel Dobbs

Graduate Theses and Dissertations

Objective. The purpose of this study is to examine factors associated with e-cigarette use among college students to better understand their behavior. Using Ajzen’s Reasoned Action Approach, this study sought to better understanding the influence of attitudes, Social norms, and perceived behavioral controls (PBCs) on college students’ intention to try e-cigarettes (even one puff) in the next 30 days.

Methodology. This study employed three phases for a mixed methods design that took place between December 2015 and April 2016. Phase 1 used Middlestadt’s salient belief elicitation procedure to capture responses through an open ended survey (n=58). Phase 2, a pilot …

Test Of An Adolescent Anxiety Sensitivity Amelioration Program (Aasap) For At-Risk Youth, Ashley Arehart Knapp

Graduate Theses and Dissertations

Adult research supports the effectiveness of targeting the malleable vulnerability factor of anxiety sensitivity (AS) in terms of preventing panic specifically and anxiety psychopathology generally. Risk factor research suggests AS modification among youth has implications for panic as well as generalized anxiety disorder (GAD). However, very little work has evaluated the impact of AS reduction among youth, which is unfortunate given adolescence is a period of “core risk” in terms of anxiety disorder onset. Further, no work has considered the effect of such a program on GAD-relevant outcomes, nor has any work included family-level intervention factors, despite evidence suggesting parents …

Comparisons Of Selected Household And Commercial Disinfectants Against Poultry Salmonella Isolates And A Survey Of Internal Parasites In Backyard Poultry In Arkansas, Kayleigh Moyle

Graduate Theses and Dissertations

Backyard and exhibition poultry have been gaining in popularity and as such there has been a large increase in the number of small flocks. As the interaction with poultry has increased, so has the opportunity for diseases and parasites, for both birds and people. One of the major zoonotic illnesses is caused by the bacteria Salmonella, which can be found in commercial and small flocks. Salmonella is the number 2 contributor of foodborne illnesses so its prevalence in commercial flocks is of high concern. Despite improved cleaning, disinfection, and biosecurity practices, there is still potential for disease outbreaks and infections …

Electrodeionization Versus Electrodialysis: A Clean-Up Of Produced Water In Hydraulic Fracturing, Brigitte Marie Rodgers

Graduate Theses and Dissertations

Electrodeionization (EDI) is a widely studied process ranging from applications in wastewater clean-up in the food and beverage industry to purifying organic compounds. To date, there are no apparent studies on applying this technology to produced wastewater recovered from hydraulic fracking sites. Water consumption within hydraulic fracturing sites can reach in the upwards of millions of gallons per site, so a need for a water recycling process becomes necessary within areas where water requirements are scarce. Implementation of an EDI module that is capable of handling high salt solutions from produced wastewater in subsequent fracturing practices will decrease overall water …

The Large-Scale Synthesis And Asymmetric Hydrosilylations Of Cuiphet, A C2-Symmetric N-Heterocyclic Carbene, Elizabeth Suzanne Spahn

Graduate Theses and Dissertations

CuIPhEt is a C2-symmetric N-heterocyclic carbene catalyst used in the asymmetric hydrosilylation of a variety of prochiral ketones with good yields and selectivities. The large-scale, five-step synthesis of this carbene has been devised. The second step of the synthetic plan includes a double asymmetric hydrogenation of a 1,1-diaryl alkene—a traditionally difficult transformation. The procedure for the use of CuIPhEt in asymmetric hydrosilylations has been optimized and used on both the originally published substrate scope and new compounds. This protocol for the hydrosilylation has been applied in a 10 g reduction to create an intermediate for use toward the total synthesis …

Shifts In Myxomycete Community Structure In Selected Microhabitats Across Nutrient Treatments In A Lowland Tropical Forest Of Panama, Laura M. Walker

Graduate Theses and Dissertations

Myxomycetes (plasmodial slime molds) are abundant amoeboid predators of bacteria and other microorganisms. They are found worldwide, largely in association with decaying plant material in terrestrial habitats. Their consumption of bacterial prey puts microbial predators such as myxomycetes in a key position in various ecosystem processes wherein they help regulate the flow of nutrients (e.g., N and C) through the ecosystem. The importance of microbial predators in nutrient cycling and plant productivity is well established. Given the extent to which tropical ecosystems influence global nutrient fluxes, along with the ecologically significant role that myxomycetes play in these processes, there is …

Social Media And Perceptions Of Sexual Consent: Development And Psychometric Assessment Of Two Consent Measures, Kelley Rhoads

Graduate Theses and Dissertations

Background. Preliminary qualitative research suggests some college students believe sexual consent can be communicated and interpreted in Social settings, such as parties or bars, and in contexts lacking face-to-face interaction like text messages and Social media content. Previous sexual consent researchers have described perceptions of consent that occur in Social settings as “outside the bedroom” consent. The belief that sexual consent can be interpreted from Social media content or that accepting an alcoholic beverage from someone at a bar is indicative of sexual consent is problematic and warrants further study. Current validated consent scales are limited and do not assess …

Investigation Of The Interaction Of Dimeric Ruthenium Complexes With Cytochrome B5, Christopher Dain Rupar

Graduate Theses and Dissertations

Photoreactive complexes to study the kinetics of electron transfer of proteins have been in use for a long time. It has always been speculated that complexes bind near the heme or the electron transfer reaction would not occur. But it is unkown exactly how the complex interacts with the protein. The structural, thermodynamic, and kinetic properties of rat liver microsomal cytochrome b5 were investigated when bound to ruthenium dimer complexes. Heteronuclear Single Quantum Coherence studies support a dynamic binding model of a dimer Ru complex bound near the protein’s heme involving residues H39, E44, G42, V61, G62, and H63. The …

Youth…Power…Egypt: The Development Of Youth As A Sociopolitical Concept And Force In Egypt, 1805-1923, Matthew Blair Parnell

Graduate Theses and Dissertations

This study focuses on youth as a symbol, metaphor, and subject involved in processes related to Egypt’s modernization, colonization, and liberation from the beginning of the nineteenth century through the 1919 Egyptian Revolution. It demonstrates that youth was not simply an unchanging stage of development between childhood and adulthood, but a construct reflecting the political, Social, and cultural interests of specific eras and perspectives. I critically analyze the local and global discourses on Egypt’s modernization, colonialism, and nationalist movement to understand how changing power relations within and outside the country affected conceptions of youth and youthfulness. Additionally, I suggest by …

The Cytotoxic And Antimicrobial Properties Of Pine Essential Oils: A Characterization And Comparison, Richard Sakul

Graduate Theses and Dissertations

In the forestry industry, the pine tree species are important because of their durable timber and fast growth. In Arkansas, trees such as the loblolly pine compose almost a third of the timberland, seven million acres. In addition to the lignocellulosic biomass, pine bark and needles potentially have industrial importance as a waste stream from which high value (e.g., pharmaceutical, cosmetics) chemicals could be extracted, which could potentially increase the profit margin of forestry operations. In this research, the possibility that pine needles harvested from industry processed pine tree residues could be used as an antibacterial or cytotoxic chemical agent …

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …

Applications Of The Gst- Affinity Tag In The Purification And Characterization Of Proteins, Wibke Beatrice Kachel

Graduate Theses and Dissertations

With the latest innovations in biological sciences, large quantities of biologically active polypeptides as well as high throughput screening methods to quickly evaluate if these biomolecules potentially have therapeutic, diagnostic, or industrial purposes are required. The synthesis and purification of peptides and small proteins continue to be demanding as the production of high yields through chemical synthesis can involve large costs. On the other hand, there are only few examples of acquiring those biomolecules through cloning and expression in bacterial systems in form of recombinant fusion proteins. Glutathione S-Transferase (GST) is not only a very commonly used affinity tag to …

From Land To Lake: Contrasting Microbial Processes Across A Great Lakes Gradient Of Organic Carbon And Inorganic Nutrient Inventories, Deborah K. Dila

Masters Theses

Freshwater ecosystems have strong linkages to the terrestrial landscapes that surround them, and contributions of carbon and inorganic nutrients from soil, vegetation and anthropogenic sources subsidize autochthonous water body productivity to varying degrees. Abundant freshwater phytoplankton and bacterioplankton are key to linking the planet's geosphere and atmosphere to the food webs in the hydrosphere through their growth and respiration. Rich resources that move through land margin waterways make them active sites for cycling organic carbon and thus important, but understudied, contributors to global climate. During 2010-2011, we examined seasonal changes in carbon and nutrient inventories, plankton community composition and metabolism …

Trophic Transfer Of A Naturally Occurring Algal Toxin From A Freshwater Lake To Little Brown Bats, Devin Jones

Masters Theses

Microcystis aeruginosa is a species of cyanobacteria capable of producing a hepatotoxin called microcystin. As toxic M. aeruginosa overwinters in the sediments of lakes, it is ingested by some mayfly larvae, such as those of Hexagenia spp., and thus

microcystin bioaccumulates in these insects. When Hexagenia emerge from lakes to

reproduce, they provide an abundant, albeit temporary, food source for many terrestrial

organisms such as bats. Little brown bats, Myotis lucifugus, likely feed opportunistically

on aquatic insects. To test if microcystin moves from aquatic to terrestrial ecosystems via trophic transfer, we 1) tested bat feces for the presence of …

Green And Choking: Exploring The Dynamics Of Seasonal Productivity And Hypoxia In A Great Lakes Area Of Concern And Habitat Blueprint Estuary Using Time-Series Measurements, Anthony D. Weinke

Masters Theses

Although hypoxia (dissolved oxygen <4 mg L-1) in the bottom waters of lakes, reservoirs, and estuaries may be a natural product of stratification in eutrophic or mesotrophic systems, there is increasing concern because the occurrence of hypoxia is spreading in many areas where hypoxia did not previously exist. Part of this new knowledge can be attributed to time-series data from buoy observatories that monitor systems in good weather and in bad, and allowing insight into the inner workings of a lake where sampling only a few times per year would not. This study made use of a five-year time-series of meteorological and water quality data in order to examine the effect of episodic wind-events on stratification and hypoxia within Muskegon Lake, Michigan, as well as performing bi-weekly lake-wide monitoring to evaluate the effects of stratification, hypoxia, and wind-events on the lake. In the wind-event portion of the study, we found that events where wind speeds were above average for an extended period of time occurred fairly frequently on the lake, but that thermal stratification allowed only the strongest events to significantly mix the water column at the buoy location a few times per year. This provided infrequent relief of hypoxia in the bottom waters. The second portion of the study found extensive effects on the water quality and biology in the bottom of the lake due to hypoxia such as increased phosphorus concentrations, enhanced phycocyanin following a strong windevent, and decreased fish abundance, richness, and size. We also found that hypoxia occurred lake-wide at all four sample locations, but was most stable at the deepest point in the lake that was least influenced by wind-events. It is possible that the combination of hypoxia and strong episodic wind-events leads to entrainment of phosphorus-rich waters to the surface initiating or continuing an algal bloom. Hypoxia and wind-event mediated internal loading of phosphorus could be a positive feedback loop for cyanobacterial blooms and hypoxia in Muskegon Lake.

Examining The Effect Of Climate Change On The Upper Mesophotic Coral Montastrea Cavernosa (Linnaeus 1767), John Skutnik

Masters Theses

Coral reefs are under increasing pressure from global climate change. In particular, ocean warming is having a deleterious effect on many of the world’s shallow reefs. Some authors suggest that acute exposure is more detrimental than chronic, versus others who indicate the opposite. However, little knowledge exists regarding heat induced stress on deeper mesophotic reefs. Here, I examined the effect of acute (72 hrs.) and chronic (480 hrs.) heat stress using laboratory experiments on coral Montastraea cavernosa (Linnaeus 1767) collected from an upper mesophotic (~30 m) reef off Islamorada Florida. I examined a variety of putative immune and stress genes …

Population Health Management Risk Assessment Tool Validation: Directing Resource Utilization, Sonya L. Christensen

Doctoral Projects

The Affordable Care Act (ACA) of 2010 is transforming health care across the nation into a value-based system that emphasizes quality and continuity with reimbursement tied to patient outcomes. The shift in emphasis is best realized through the strategy of Population Health Management, a change from traditional episodic treatment of illness to management of the health needs of populations throughout the continuum of health. The goal of care is to ensure that patients, especially the chronically ill, receive effective attention to their health needs in order to improve outcomes, decrease costs, and provide a positive patient experience. An important component …

Evaluating Foraging Habits, And Estimating Prey Consumption, And Growth Of Brook Trout In A Coolwater Michigan Stream, Graeme R. Zaparzynski

Masters Theses

Brook trout (Salvelinus fontinalis) are a cold water ectotherm whose native distribution includes most of eastern Canada, the upper Midwestern United States, and the eastern and mid- Atlantic United States as far south as Georgia. The native range of brook trout in the United States has been reduced as a result of interspecific interactions with introduced species, and anthropogenic land use changes that drive water temperature changes in many of their native watersheds. Anthropogenic land-use changes tend to increase thermal regimes of aquatic systems, affecting brook trout physiology and limiting them to colder, headwater reaches. The threat of …

Development Of A Sandwich Enzyme-Linked Immunosorbent Assay (Elisa) For Detection Of Macadamia Nut Residues In Processed Food Products, Charlene Gan

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Macadamia nut is considered a priority food allergen and undeclared macadamia nut residues pose a potential food safety risk to individuals with macadamia nut allergies. To date, there are a limited number of immunochemical methods that are available for detection of processed macadamia nut residues. Therefore, the aim of this study was to develop a reliable and robust sandwich ELISA for detection of macadamia nut residues. Raw and roasted macadamia nuts were used for immunization in three different species of animals (sheep, goat, and rabbits). Macadamia nut specific IgG antibodies produced by each animal were tested for their specificity and …

Chromosome-End Knockoff Strategy To Reshape Alkaloid Profiles Of A Fungal Endophyte, Simona Florea, Timothy D. Phillips, Daniel G. Panaccione, Mark L. Farman, Christopher L. Schardl

Plant Pathology Faculty Publications

Molecular genetic techniques to precisely eliminate genes in asexual filamentous fungi require the introduction of a marker gene into the target genome. We developed a novel strategy to eliminate genes or gene clusters located in subterminal regions of chromosomes, and then eliminate the marker gene and vector backbone used in the transformation procedure. Because many toxin gene clusters are subterminal, this method is particularly suited to generating nontoxic fungal strains. We tested this technique on Epichloë coenophiala, a seed-transmissible symbiotic fungus (endophyte) of the important forage grass, tall fescue (Lolium arundinaceum). The endophyte is necessary for maximal …

Identification Of Diverse Mycoviruses Through Metatranscriptomics Characterization Of The Viromes Of Five Major Fungal Plant Pathogens, Shin-Yi Lee Marzano, Berlin D. Nelson, Olutoyosi Ajayi-Oyetunde, Carl A. Bradley, Teresa J. Hughes, Glen L. Hartman, Darin M. Eastburn, Leslie L. Domier

Plant Pathology Faculty Publications

Mycoviruses can have a marked effect on natural fungal communities and influence plant health and productivity. However, a comprehensive picture of mycoviral diversity is still lacking. To characterize the viromes of five widely dispersed plant-pathogenic fungi, Colletotrichum truncatum, Macrophomina phaseolina, Diaporthe longicolla, Rhizoctonia solani, and Sclerotinia sclerotiorum, a high-throughput sequencing-based metatranscriptomic approach was used to detect viral sequences. Total RNA and double-stranded RNA (dsRNA) from mycelia and RNA from samples enriched for virus particles were sequenced. Sequence data were assembled de novo, and contigs with predicted amino acid sequence similarities to viruses in the …