Digital Commons Network^™

Comparing Virus Ultrafiltration Of Bacteriophages With Filtration Of Minute Virus Of Mice, Kent Smith

Graduate Theses and Dissertations

Industrial production of protein therapeutics demand rigorous testing and clearance of viruses. The U.S. Food and Drug Administration dictate the purity of pharmaceuticals with regards to viral contamination. As this testing is time consuming and expensive using mammalian cells and viruses, bacteriophages may provide a faster and cheaper alternative for membrane filtration processes. We used ultrafiltration membranes to filter protein solutions with viruses. Two bacteriophages were tested against membranes with two different pore sizes. These membranes were then tested by inverting the membrane's orientation. Flux measurements and log virus removal data were taken. Flux and log virus removal were seen …

Chitosan Reduces Enteric Colonization Of Campylobacter In Young Chickens, But Not On Post-Harvest Chicken Skin Samples, Hanna Royce Arambel

Graduate Theses and Dissertations

Worldwide, Campylobacter is one of the leading causes of foodborne bacterial gastroenteritis causing an estimated 1.3 million infections in the United States alone. Consumption and/or cross-contamination of raw or undercooked poultry products have been linked as the most common source of Campylobacter infection, making the poultry industry a target for Campylobacter reduction strategies. Campylobacter is prevalent in most poultry flocks in the United States, with as many as 90% of flocks Campylobacter-positive at the time of slaughter. It is estimated that a reduction of Campylobacter in poultry would greatly reduce the risk of campylobacteriosis in humans. Unfortunately, there are …

Estimating Nitrogen Credits From Poultry Litter On Silt Loam Soils In Arkansas Using The Nitrogen-Soil Test For Rice: N-Star, Chester Eugene Greub

Graduate Theses and Dissertations

Rice (Oryza sativa L.) is one of the most important global cereal crops and is grown on a substantial number of hectares in Arkansas each year. Consequently, Arkansas is the leading rice producing state in the United States accounting for almost half of domestic production. The development and release of N-STaR (Nitrogen-Soil Test for Rice) allows producers to predict site-specific N fertilizer needs for rice production in Arkansas, with N-STaR being a predictor of potentially mineralizable-N. Furthermore, poultry production is a thriving commodity in Arkansas, producing a substantial amount of poultry litter (PL) annually. Rice producers are applying PL to …

21st Century Radicalization: The Role Of The Internet User And Nonuser In Terrorist Outcomes, David Wayne Woodring

Graduate Theses and Dissertations

This study examines differences between users and nonusers of information communication technologies (ICTs) within the pre-incident planning processes for domestic terrorist movements operating within the United States. In addition, this study is the first quantitative exploration of the prevalence, types, and purposes of ICT use within terrorist movements, specifically environmental, far-right, and Islamic extremist movements. Using "officially designated" federal terrorism investigations from the American Terrorism Study (ATS), we analyzed extracted evidence of ICT usage among individuals (n =331) engaged in the pre-incident planning processes as members of terrorist movements between 1995-2011. While we find significant differences in terrorist ICT use …

Porosity Development Within Lobes To Downslope Ramp Deposits On A Prograding Carbonate Shelf Of The Kinderhookian To Osagean Series In Northwest Arkansas, Elizabeth Marchese

Graduate Theses and Dissertations

Carbonate bodies with lobate geometries form a substantial part of the Osagean (early Mississippian) section in northwest Arkansas. The purpose of this study is to isolate and describe a single lobe from three-dimensional exposures in quarry walls to provide criteria by which lobe and lobe porosity can be recognized in the subsurface. Carbonate sediment generated on the Mississippian Burlington shelf moved southward by gravity flows from the shelf margin to positions on a prograding ramp in Arkansas where overlapping deposits with lobate geometries accumulated. These deposits are recognized in outcrops of the Boone Formation. Stratigraphic units within the Boone are …

Effect Of Limit-Fed Co-Product Feedstuffs On Production, Digestion, Fermentation And Rumen Function In Beef Cattle, William Brandon Smith

Graduate Theses and Dissertations

In terms of energy density, the cost of shipping hay is often not justified in yr where adverse conditions limit available forage. Our objective was to determine if co-product feedstuffs could be used to meet the energy demands for cows in late pregnancy. Eighty-six crossbred cows (527 ± 0.8 kg BW) in late gestation were stratified by BW, BCS and age and allocated randomly to 1 of 6 groups held on 2-ha dormant bermudagrass pastures for 68 d. Three groups were offered bermudagrass hay ad libitum (HAY) and three groups were offered 6.4 kg of soybean hulls (LSH) daily and …

Production Of A Soybean Meal With High-Protein And Low Anti-Nutritional Factors For Fish Feed, Maria De Las Mercedes Castro

Graduate Theses and Dissertations

Aquaculture is one of the fastest growing areas of the food production system. According to the FAO, its rise is expected to continue through the year 2030 in order to maintain per-capita consumption levels required for the increasing population. Fishmeal--obtained from wild-harvested fish--has been the source of protein for fish feed. However, data indicates that these fish harvests are in decline, which could restrain that growth. The possibility of a shortage of fishmeal prompted the industry to look into possible alternatives. Soybean meal appears as a promising substitute since it is an affordable high quality source of protein. However, the …

Friction And Wear Of Polytetrafluoroethylene/Graphene Oxide Composite Thin Films, Justin Kyle Carter

Graduate Theses and Dissertations

Polytetrafluoroethylene (PTFE) is a commonly used solid lubricant due to its low coefficient of friction and chemical inertness. As a polymer, PTFE suffers from high wear and low adhesion to substrates limiting its use as a thin film. Thin PTFE films are ideal candidates for solid lubrication in micro-machines and bearing applications. The main goal of this work is to enhance the durability of thin PTFE films through the addition of few layered graphene oxide (GO) as filler. In order to address adhesion issues, the addition of an adhesive layer of polydopamine (PDA) between stainless steel substrates and thin PTFE …

Effects Of Rain And Simulated Rain On Deoxynivalenol Levels In Grain And Chaff Of Winter Wheat With Fusarium Head Blight, Manoj Kumar Pun

Graduate Theses and Dissertations

Wheat grain affected by Fusarium head blight (FHB) contains the mycotoxin deoxynivalenol (DON) that is harmful to humans and animals. Reducing the amount of DON in grain is the goal of management practices for FHB so it is important to understand the factors affecting DON in grain. Some studies on the effects of late-season moisture found increases in DON while others found decreases due to leaching. The objectives of this study were to determine effects of late-season rain and misting on DON concentration in wheat spike tissues and to quantify the amount of DON leached from spikes. Field experiments were …

Effect Of Prescribed Burning In The Forests Of Buffalo National River, Arkansas, Francis Ndar Onduso

Graduate Theses and Dissertations

Prescribed burning (also referred to as controlled or hazard reduction burning) refers to the use of fire under controlled conditions to achieve a desired end product or goal. However, the nature and magnitude of the changes that result from prescribed burning are still incompletely known, and this is especially true for the forests of the Ozarks of northern Arkansas. The overall objective of the research project described herein was to obtain the data necessary to develop a better understanding of these changes, particularly as they relate to the use of prescribed burning as a management technique in the Buffalo National …

Development Of Novel Antifungal Peptides Based On A Natural Model Of Histatin-5 Peptide, Duy Tu Nguyen

Graduate Theses and Dissertations

Our research group is working toward the development of novel antifungal peptides based on a natural model of peptide histatin-5. Histatin-5 is found in human saliva and known to protect our body against oral infections by Candida species. Candidiasis, or an infection caused by Candida species, is considered one of the most medically important fungal infections worldwide. Blood stream infections caused by Candida species are the fourth leading cause of hospital-acquired fungal infections that is associated with high mortality rates and high costs of treatment. This study investigated the modes of action of histatin-5 with the use of one 16-mer …

Environmental Literacy Of Sixth Grade Students In Arkansas: Implications For Environmental Education Reform, Lisa Suzanne Wood

Graduate Theses and Dissertations

Environmental education must be better integrated into K-12 curriculum to advance environmental literacy. Producing a citizenry that can understand and address the complex environmental issues facing the world today and in the future is essential to sustainable life on this planet.

Using the Middle School Environmental Literacy Survey, 6th grade students across Arkansas were surveyed to obtain a baseline measure of environmental literacy based on the four domains of environmental literacy included in the survey; ecological knowledge, environmental affect, cognitive skills, and behavior. Individual domain scores were combined into a composite environmental literacy score. Results were then compared to the …

Identification Of Biomarkers Associated With Ascites Incidence In Broilers, Kaylee Rowland

Graduate Theses and Dissertations

Poultry is key in genetic research due to breeding feasibility, relatively short generation interval, and distinct phenotypes. It is estimated that 8% of broiler deaths annually can be attributed to ascites, an economically important disease that has been challenging the industry for the past 2 decades. Genetically selected ascites resistant (RES) and susceptible (SUS) chicken lines have been established and maintained by the University of Arkansas, Fayetteville. Intensive research efforts have been made to reveal physiological and biochemical characteristics for the incidence of ascites. Since the whole genome of the major ancestral chicken, the Red Jungle Fowl, has been sequenced, …

Effect Of Modified Starch On Bake-Only Chicken Nuggets, Sarah Purcell

Graduate Theses and Dissertations

The food industry has become increasingly focused on healthier items. Fried foods especially are actively pursuing non-fried alternatives to attract health conscience consumers. This study investigated the bake-only chicken nugget formulation in attempts to provide characteristics of fried items. Starch was hydrolyzed by amyloglucosidase to create a porous structure that had the ability to absorb oil. Oil was plated into the enzyme-treated starch and blended into nugget formulation, and the coated nuggets were steam-baked until fully cooked. The enzyme-treated starches showed a decrease in gelatinization range and pasting viscosities for all starch types. The addition of oil-plated enzyme modified starch …

The Effect Of Calcium And Nonphytate Phosphorus On Chicken Genetic Line, Egg Production, Shell Quality, Bone Homeostasis, And Progeny Bone Quality, Phiphob Sodsee

Graduate Theses and Dissertations

The study consisted of two parts to determine effects of dietary calcium (Ca) and nonphytate phosphorus (NPP) level on four pure genetic lines of broiler breeders. The first part was concentrated on body composition, egg production and shell quality changes according to diet and genetic line. The second part was the study of bone homeostasis variables combining hematology, bone histology and body composition changes according to diet and genetic line. In the study, pullets (246 from each of pure genetic line A, B, C and D) were individually caged and light stimulated at 21 weeks of age. The study duration …

The Color And Consistency Of Steaks And Ground Beef Produced From Mature Bulls, Jace Joseph Hollenbeck

Graduate Theses and Dissertations

Two experiments were conducted to compare the color and cooked attributes of steaks and ground beef produced from mature bulls. Beef from mature bulls was used to test the effects of lactic acid (LA) enhancement solution pH (2.5, 3.0, or 3.5; B25, B30, B35, respectively) on fresh (5 d of display) and cooked color and tenderness of strip loin steaks (Exp. 1) and the effect of high pH trim on precooked ground beef patties (Exp. 2). In experiment 1, mature bull strip steaks were enhanced to 111% with a LA, sodium bicarbonate, and tap water solution, in comparison to USDA …

Development And Evaluation Of Chitosan Particle Based Antigen Delivery Systems For Enhanced Antigen Specific Immune Response, Bhanuprasanth Koppolu

Graduate Theses and Dissertations

Particle-based vaccine delivery systems are under exploration to enhance antigen-specific immunity against safe but poorly immunogenic polypeptide antigens. Chitosan is a promising biomaterial for antigen encapsulation and delivery due to its ability to form nano- and microparticles in mild aqueous conditions thus preserving the antigenicity of loaded polypeptides. The objective of this work is to develop a chitosan particle based antigen delivery system for enhanced vaccine response. Chitosan particle sizes, which ranged from 300 nm to 3 ìm, were influenced by chitosan concentration, chitosan molecular weight and addition rate of precipitant salt. The composition of precipitant salt played a significant …

Bacterially-Mediated Formation Of Rock Coatings In Kärkevagge, Swedish Lapland: A Mineralogical And Micro-Environmental Analog For Mars, Cassandra L. Marnocha

Graduate Theses and Dissertations

The search for past or present life on Mars is, for now, limited to surface environments. An often neglected surface environment that could have served as an abode for life and could presently preserve evidence of that life is that of rock coatings. Rock coatings are mineral accretions on rock surfaces. On Earth, they are widespread and occur with considerable chemical diversity. There is growing evidence for a biotic role in their formation on Earth, particularly with respect to rock varnish. As a result, rock varnish has become a target of astrobiological interest on Mars, where varnish-like coatings have been …

In Vitro Analysis Of Short Chain Fatty Acids And Human Fecal Microbiota Stimulated By Pectin Sources, Byungjick Min

Graduate Theses and Dissertations

As interest increases for colonic health, various studies have been conducted to investigate functional ingredients for host health and prevention of chronic disease in humans such as colon cancer and Type 2 diabetes. In particular dietary fiber has been reported to have beneficial effects on colonic health. More recently, dietary fiber has been categorized based on its characteristics and numerous studies have been conducted to determine correlations with chronic diseases. Pectin is a naturally occurring biopolymer that has been used in various applications for purposes of pharmaceutical and biotechnology. Pectin is a soluble dietary fiber and can be entirely fermented …

Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang

Graduate Theses and Dissertations

Influenza is a common infectious disease resulting from a frequently mutated RNA virus. Vaccination is currently the most effective method to prevent people from seasonal or pandemic influenza. The production of traditional egg-based influenza vaccine is time-consuming and provides limited effect against new strains. Therefore, it is necessary to develop a rapid method to produce influenza vaccines. We proposed a novel influenza vaccine based on the E.coli expression system. Hemagglutinin (HA) is the major target surface protein of influenza virus for vaccine development. In this study, we sub-cloned the HAs encoding gene into an E. coli expression vector; the signal …

Enhanced Pancreatic Beta-Cells Proliferation And Functionality, Hanan Abdulaziz Alismail

Graduate Theses and Dissertations

Biologically functional beta-cells proliferate at an extremely low rate with limited turnover capacity. This cellular property hinders cell-based therapy for clinical applications. Many attempts have been made to develop techniques that allow large quantities of production of clinically relevant islet β-cells in vitro. A line of studies demonstrates that functional beta-cells can proliferate under certain circumstances, providing hope for generating and expanding these cells in vitro and transplanting them into the recipient. In this study, we showed that a membrane substrate offers a better niche for beta cell proliferation and insulin secretion. Mouse beta cells were grown on a tissue …

Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku

Graduate Theses and Dissertations

GLS is a serious foliar disease of maize, a major staple crop grown commercially in the USA for both human and animal feed production, and increasingly, for ethanol production. The disease is caused by two Cercospora species, C. zeae-maydis and C. zeina, both of which infect maize in the USA and in other parts of the world, with yield losses potentially greater than 50%, depending on local conditions. In culture, C. zeae-maydis produces a phytotoxic, host non-specific perylenequinone, cercosporin, and abscisic acid (ABA), for which there is no known pathological or physiological function in the fungus. Experimental evidence indicates …

The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh

Graduate Theses and Dissertations

In this thesis, different methods to improve the microdialysis collection procedure for cytokines from brain tissue are presented. The first method was based on stopped flow and results indicating that no significant difference in relative recovery between stopped flow and continuous flow are shown. The second method is an antibody bead-based enhancement method. With the antibody bead-based method, a 3.5 fold increase in the collected concentrations of Chemokine (C-C motif) Ligand 2 (CCL2) were observed. However, there was no significant increase in the in vivo collection efficiency of Interleukin-6 (IL-6) using the antibody enhancement. Finally the development of an in-house …

A Comparison Of Nebulized Vitamin B12 Versus Oral Vitamin B12 Supplementation, Terry L. Williams Jr.

Graduate Theses and Dissertations

Vitamin B12 is important for various processes in the human body including DNA synthesis, red blood cell production, energy production, fatty acid synthesis, and for the conversion of homocysteine into methionine. Vitamin B12 deficiency is becoming more prevalent. The purpose of this study was to evaluate if a different route of administration, i.e. nebulization, was a viable option for increasing serum levels of vitamin B12 in both exercisers and non-exercisers. The increasing number of people that are vitamin B12 deficient is due to several factors including medication use, elective gastric bypass surgery, and an increasing elderly population. There are currently …

Physical And Biochemical Factors Affecting Breast Fillet Tenderness In Broilers Reared For Divergent Market Demands, Valerie Belle Brewer

Graduate Theses and Dissertations

Market trends have dictated that broilers be reared for divergent market demands for decades. Also, broiler genetic strains have been adapted to meet market demands which include: genetic selection for improved breast meat, the practice of growing birds to older ages and greater market weights to meet demands, and decreasing postmortem (PM) aging time to improve processing efficiency and fillet yield. These production practices can also affect product quality, specifically boneless breast fillet tenderness and water-holding capacity. To address these factors, a series of experiments were conducted to determine the effect of strain and slaughter age on meat quality parameters, …

Greater Sage-Grouse (Centrocercus Urophasianus) Habitat Selection In Northwestern Wyoming And Stable Isotope Analysis Of Fecal Material, Andrea Renee Green

Graduate Theses and Dissertations

Dramatic range-wide declines in Greater Sage-Grouse populations have prompted efforts to determine habitat characteristics that are selected by sage-grouse for foraging, nesting and brood-rearing areas in an effort to conserve this species. Managers at Heart Mountain and Y U Bench in northwestern Wyoming expressed the need to quantify various habitat characteristics and to determine key use areas at both study sites. Data were collected on a variety of habitat variables in spots selected by grouse for foraging, nesting, and brood-rearing activities. These variables were compared to the same variables measured at random points at both study sites. Significant differences existed …

The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller

Graduate Theses and Dissertations

Approximately 1.7 million Americans experience a traumatic brain injury (TBI) each year. Concussive injuries are a subset of TBI in which blows to the head cause the brain to collide against the interior of the skull. Damage to the neurons, supporting cells, and surrounding extra cellular matrix resulting from these collisions can lead to permanent physical, cognitive, and psychological impairment. We believe the prevalence and clinical significance of concussive injures warrants research investment. To study brain injury following TBI, in vivo models have been the gold standard for TBI experiments. Although a valuable research alternative, animals are expensive, raise ethical …

Relationships Between Landscape Factors And Crayfish Density And The Interacting Effects Of Grazing And Increased Sedimentation On Algal Biomass, Katheryn Haley Rose

Graduate Theses and Dissertations

In recent years in the United States there has been a rapid expansion in anthropogenic sources of sediment in streams including construction, agriculture, and drilling for natural gas. Potential effects land disturbance associated with activities from natural gas development on aquatic biota in surrounding streams have not yet been well documented. An increase in inorganic sediment in streams can be detrimental to organisms through a variety of mechanisms including alteration of dominant substrate type, higher turbidity resulting in lower visibility, and burial of food resources such as algae and detritus. Increasing sedimentation in stream environments through anthropogenic disturbance is a …

Phenotypic, Physiological And Growth Interactions Among Salmonella Serovars, Juliany Rivera Calo

Graduate Theses and Dissertations

This thesis consists of four research parts: a literature review that covers Salmonella spp., one of the more prominent foodborne pathogens that represents a major risk to humans (chapter 1). Understanding the growth of Salmonella serovars and strains is an important basis for more in depth research. In this case we studied a) the aerobic and anaerobic growth responses of multiple strains from six different serovars, b) how the spent media from different serovars, more importantly S. Heidelberg, affect the growth of S. Typhimurium, and c) determined whether or not two different serovars undergo competitive interactions when they were …

Effect Of Functional Starch In Brown Rice And Grain Sorghum On Plasma Glucose And Insulin Responses In Humans, Nicole Marie Poquette

Graduate Theses and Dissertations

Diabetes and obesity are chronic illnesses increasing at dramatic rates in the U.S. and around the world. Research has looked to prevent or control diabetes and obesity through functional ingredients such as healthy-dietary carbohydrates to control blood glucose levels. Starch is a principle carbohydrate, which influences blood glucose levels, and measuring starch digestibility fractions can help predict the glucose response in the body. The objectives of this study were to investigate the functional starch content of parboiled brown rice flour and grain sorghum flour, and measure the effects on postprandial plasma glucose and insulin levels of 14 and 10 healthy …