Digital Commons Network^™

Aesthetic Qualities Of Websites And Their Effects On Public Perceptions Of Agricultural Issues And Organizations, Chase Tyler Hundley

Graduate Theses and Dissertations

This study sought to evaluate perceptions of agricultural issues and organizations based on how information is presented visually in websites. Researchers intended the results to be used to help the agricultural industry more effectively communicate information through better website design and increased persuasiveness. The study was conducted through the use of three focus group sessions as mapped out by Krueger (1998a, 1998b, 1998c) and Morgan (1998a, 1998b). The study used non-agriculture students purposively selected from a class in the University of Arkansas School of Human Environmental Sciences as participants in the study. The subject demographics closely resembled the primary demographics …

The Impact Of Bovine Spongiform Encephalopathy (Bse) On World Protein Supply, Jarrod Kersey

Graduate Theses and Dissertations

As world population, per capita income and urbanization increase, consumption of meat, poultry, milk and eggs will continue to rise to meet the needs of approximately nine billion people in 2050. Global beef, pig and chicken production and per capita consumption increased between 2000 and 2010, with growth in broiler production and consumption outpacing both beef and swine. The increased production and consumption requires readily available feed ingredients in regions where animal production is rapidly developing. Animal-based protein feed ingredients are often difficult to move from country to country due to real or perceived risk of animal disease. Zoosanitary standards …

Evaluation Of The Recombination Efficiencies Of Flp Proteins, Linh Duy Nguyen

Graduate Theses and Dissertations

Site-specific recombination systems are powerful tools for genetic modification. They have been used to integrate a transgene into a pre-defined locus and to remove marker genes from a transgene locus. Two of the most widely used site-specific recombination systems in plants are the Cre/lox system from the bacteriophage P1 and the FLP/FRT system from the yeast Saccharomyces cerevisiae. The Cre/lox system is well-characterized and is the first choice in application of site-specific recombination system. However, some applications such as marker-free site-specific gene integration require the use of two recombination systems. In addition, the availability of alternative recombination systems can offer …

False Smut Of Rice: Histological Analysis Of Infection, Liem Thi Thanh Nguyen

Graduate Theses and Dissertations

False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (Teleomorph: Villosiclava virens), has become a common disease in most major rice growing regions throughout the world. Considerable confusion exists regarding the infection process and the disease cycle. Therefore, a clearer understanding of pathogenesis caused by Ustilaginoidea virens is critical for future efforts to develop genetic and chemical tools to manage false smut in Arkansas and other regions of the world. The overall goal of this research was to clarify the infection process underlying false smut, with emphasis on comparing and contrasting the histological basis of root and foliar infections. …

Documentation And Control Of Acetolactate Synthase-Resistant Barnyardgrass (Echinochloa Crus-Galli) In Arkansas Rice, Michael Joshua Wilson

Graduate Theses and Dissertations

Barnyardgrass, the most problematic grass weed of Arkansas rice, was found resistant to propanil in 1990, and since then, it has evolved resistance to quinclorac and clomazone. Barnyardgrass is now believed to have evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. The goal of this research was to confirm and determine the level of resistance of the putative resistant biotype to the ALS-inhibiting herbicides imazethapyr, bispyribac, and penoxsulam and to develop herbicide programs for controlling ALS-, propanil-, quinclorac-, and clomazone-resistant barnyardgrass. The lethal dose needed to kill 50% of the putative ALS-resistant plants was higher than that of the susceptible biotype …

Penetration Forces For Subsurface Regolith Probes, Ahmed Elshafie

Graduate Theses and Dissertations

Investigating planetary bodies using penetrometers can provide detailed information about its history and evolution. An estimation of subsurface density and porosity can be made from the shape of the penetration curve. Using penetrometers mounted on planetary platforms could be challenging due to the uncertainty of the subsurface composition and since the maximum allowed force for penetration is the weight of the lander or rover on the surface. Estimation of penetration forces can provide a reliable constraint on the maximum reachable depth without endangering the whole mission. Therefore, knowledge of the required penetration force to specific depths can be helpful in …

Predictability Of Food And Wine Pairing Using A Sensory Approach, Rebeckah L. Koone

Graduate Theses and Dissertations

The purpose of this study was to explore significant differences in perception of match for a variety of food and wine styles; evaluate the impacts of wine sweetness level, wine acidity level, and wine tannin level on perception of match; and to investigate the impact of food and wine expertise on perceived level of match. A field research design was used to explore expert recommendations of food and wine combinations to obtain broader feedback on consumer perceptions. The population consisted of a convenience sample of 248 students enrolled in a continuing education course in food and wine pairing at George …

Inquiry-Based Instruction In The Social Studies: Successes And Challenges, Crystal Maree Beshears

Graduate Theses and Dissertations

The purpose of this study was to investigate teachers' perceptions, understanding, and use of inquiry-based instruction in the Social studies, to assess the impact of inquiry-based units on instruction, to detail implementation successes and challenges reported by teachers when implementing inquiry-based instruction, and to provide recommendations for future efforts. Teachers' perceptions of teaching and learning, particularly their beliefs about inquiry-based instruction, changed during the study. Throughout the study, teachers' perceptions and beliefs about teaching Social studies had an impact on how they planned, implemented and reflected on inquiry-based instruction. Many of the teachers changed their perceptions and began regularly teaching …

Meta-Analysis Of Wheat Qtl Regions Associated With Heat And Drought Stress, Marlovi Andrea Acuna Galindo

Graduate Theses and Dissertations

Heat and drought are the two most important environmental constraints to wheat production globally, are often present simultaneously and will become more severe with global climate change. This presents a unique challenge to wheat scientists who must work to develop wheat cultivars that are productive and adapted to future environmental conditions. A number of recent studies have reported quantitative trait loci (QTL) associated with heat and drought tolerance, as well as QTL for stress adaptive traits such as the availability of stem carbohydrates or crop canopy temperature. The objective of this study was to perform a meta-analysis of these QTL …

Effects Of Meloidogyne Incognita, Soil Physical Parameters, And Thielaviopsis Basicola On Cotton Root Architecture And Plant Growth, Jianbing Ma

Graduate Theses and Dissertations

The root-knot nematode, Meloidogyne incognita, and the seedling pathogen, Thielaviopsis basicola, commonly co-exist in Arkansas cotton fields and may interact resulting in increased losses. The primary objective of this research was to evaluate the effects of soil physical parameters on these soilborne pathogens and cotton growth in controlled environmental, field, and microplot studies. Controlled environmental experiments used two soil bulk densities and four pathogen treatments: non-infested soil, soil infested with M. incognita or T. basicola and soil infested with both pathogens. The results indicated bulk density generally did not affect seedling growth or disease since soils had low penetration resistance …

Genetic Diversity, Pathogenicity/Virulence Variation And Population Structure Of Rhizoctonia Spp. Associated With Rice Sheath Blight In Arkansas And Qtl Mapping For Disease Resistance, Vanina Lilian Castroagudin

Graduate Theses and Dissertations

Rice sheath blight (ShB) is one of the most prevalent diseases in rice. The significance of this disease is increasing due to more intensive production practices globally. Rhizoctonia solani Kühn AG 1 - IA [teleomorph: Thanatephorus cucumeris (A.B. Frank) Donk] is considered the primary ShB pathogen of rice. However, Rhizoctonia oryzae-sativae, Rhizoctonia oryzae, and R. solani AG 2 and AG 11, have also been isolated from sheath blight-like lesions on rice.Up to now, there is little information on genetic diversity and patterns of molecular evolution of the fungus, and there is no study on the structure of the R. solani …

Effects Of Environment And Genotype On Charcoal Rot Development On Soybeans, Micah Diane Doubledee

Graduate Theses and Dissertations

Charcoal rot of soybean, caused by the soilborne fungus Macrophomina phaseolina (Tassi) Goid, is a disease associated with high soil temperature and low soil moisture. Above-ground symptoms, which can be difficult to distinguish from drought symptoms, include low vigor, dead leaves that remain attached to the plant, early senescence and yield loss. Irrigation limits damage, but does not prevent colonization of the tissue by the pathogen. No soybean line is immune to M. phaseolina, but a few lines may have moderate resistance. The objectives of this research were to 1) determine the effects of genotype and drought on the development …

Ant Tribe, Yan Zhao

Graduate Theses and Dissertations

"Ant Tribe" describes the post-80s generation university graduates who live together in poor conditions without Social security in communities around China's major metropolises. They dream of a better life in big cities but struggle with low-paying jobs. These struggling "elites" have become the fourth weak Social group, after peasants, migrant workers and unemployed people. The reason why these college graduates are compared to ants is that they are like ants: clever, hardworking, politically weak and living in groups.

The real world is always different from the ideal world of the "Ant Tribe" in China. They often lose their purposes in …

Effects Of Testing Time On Anaerobic Toxicity Assessment, Omolola Atinuke Akintomide

Graduate Theses and Dissertations

Anaerobic digestion has been widely used for wastewater treatment for decades. Several Anaerobic Toxicity tests have been developed to screen wastewater for toxicity and assess the treatability of such toxicants. However, past research and reviews on Biochemical Methane Potential (BMP) test and Anaerobic Toxicity Assay (ATA) were considered in this study.

The experimental tests included ammonium-nitrogen and sodium chloride toxicity tests with varied concentration and solid retention time. These tests were designed to demonstrate the impact of ammonia- nitrogen and sodium chloride on the biological degradation process. The anaerobic test set-up includes bench-scale test reactors and respirometers used for measuring …

Investing In An Agricultural Legacy, Leo Paul Goeringer

Graduate Theses and Dissertations

America's agricultural producers continue to age. According to the U.S. Census of Agriculture, the average age of farm operators increased from 55.3 in 2002 to 57.1 in 2007. During the same period, the Census shows a thirty percent decrease in the number of farmers under age 25. Young and beginning producers (YBPs) entering agriculture face high startup costs and a shortage of land to own or rent.

With these concerns in mind, this manuscript details the impact of an innovative proposed loan program for YBPs in Arkansas, which would offer concessionary interest rates and loan fees by participating banks for …

Evaluation Of Prebiotic Fibers And Pectin On Probiotic Strains And Effect Of Bacteriocin-Like Substance On The Survival Of Listeria Monocytogenes, Dolar Pak

Graduate Theses and Dissertations

Probiotics and prebiotics have been shown to provide beneficial effects on the host health and there are numerous research efforts being conducted on a variety of specific applications. However, most prebiotic carbohydrates are lower molecular weight oligosaccharides; and the health benefits of higher molecular weight pectins have not been fully evaluated. According to reviews, pectins are fermented in the large intestine due to the cooperative activities of colonic bacteria with complementary enzymatic activities. There are very few studies that demonstrate the fermentability of high methoxy pectin and low methoxy pectin by pure cultures of human isolates or probiotic bacteria. Thus, …

Characterization And Quantification Of Monomers, Oligomers, And By-Products From Xylan During Biomass Pretreatment, Ching-Shuan Lau

Graduate Theses and Dissertations

Biomass pretreatment generates inhibitory products, which reduce the overall yield of xylose for ethanol production. Understanding of hemicellulose depolymerization into xylose is essential to identify the pretreatment conditions that maximize xylose formation, but minimize the generation of these inhibitory products, such as formic acid and furfural. Thus, the goal of this project is to understand how dilute acid pretreatment parameters affect hemicellulose depolymerization, maximize xylose concentrations, and minimize by-products formation.

To progress towards this goal, rates and mechanisms of hemicellulose release must be determined. Birchwood xylan was used as the starting material to produce xylose oligomers. The hydrolyzed birchwood xylan …

Locating And Protecting Facilities Subject To Random Disruptions And Attacks, Hugh Medal

Graduate Theses and Dissertations

Recent events such as the 2011 Tohoku earthquake and tsunami in Japan have revealed the vulnerability of networks such as supply chains to disruptive events. In particular, it has become apparent that the failure of a few elements of an infrastructure system can cause a system-wide disruption. Thus, it is important to learn more about which elements of infrastructure systems are most critical and how to protect an infrastructure system from the effects of a disruption. This dissertation seeks to enhance the understanding of how to design and protect networked infrastructure systems from disruptions by developing new mathematical models and …

The Contradictory Nature Of Natural Mothering: A Discursive Analysis, Britni Lee Ayers

Graduate Theses and Dissertations

In our contemporary sociopolitical rhetoric breastfeeding is something that is natural and something women ought to do because breast is best. The problem with this contemporary discourse of breastfeeding and motherhood is that the dominant medical, political, technological, and patriarchal discourses surrounding breastfeeding have merged to create an highly unattainable definition of what it means to be a "good mother" (Blum 1993). Moreover, upon a close examination, the most pressing political and Social debates of today surrounding the welfare reform, women's employment, reproductive technologies, and abortion, among many others, construct distinctions between "good mothers" and "bad mothers." However, there has …

Single-Pass Drying Of Rough Rice Using Glass Transition Principles, George Owira Ondier

Graduate Theses and Dissertations

The objective of this research was to study the drying characteristics, milling quality, and functional properties of rough rice subjected to single-pass drying while controlling kernel material states. Drying experiments were conducted at 60, 70, and 80C and relative humidities ranging from 13 to 83%. High drying air relative humidities (greater than 63%) maintained both the kernel surface and core in a rubbery state during drying, whereas low drying air relative humidities caused rapid transitioning of the surface layers from a rubbery to a glassy state. Long-grain pureline cultivar, Wells, medium-grain pureline cultivar, Jupiter, and long-grain hybrid cultivar, CL XL729, …

The Role Of Antioxidant Rich Berries In The Prevention Of Postmenopausal Bone Loss, Lydia Karimi Kaume

Graduate Theses and Dissertations

Postmenopausal osteoporosis is the most prevalent form of osteoporosis and results in fragility fractures. Smoking is one of the major risk factors for osteoporosis and is known to aggravate bone loss in postmenopausal women due to increased oxidative stress and inflammation. Diet-based interventions using berries have shown bone protective affects in animal studies partially due to antioxidant and anti-inflammatory properties of their phenolic compounds. The goal of this research was to determine the effects of antioxidant-rich fruits in the prevention of postmenopausal bone loss. Our first study examined the dose dependent effects of blackberries in preventing bone loss in an …

The Evolution Of Natural Plant Communities Through Crop Migration And Crop-To-Weed Gene Flow, Meredith G. Schafer

Graduate Theses and Dissertations

With the rising demand for food and biofuels, the efficiency of crop production has become vital to assuring food security. Genetically engineered (GE) crop varieties are broadly thought to be a solution for improving the efficiency of crop production, but concerns regarding their release have heightened as more discoveries have focused on the influence of genetically engineered crops on native and weedy plant species. Risk assessment of GE crop varieties focuses on two main areas: feralization of crop systems and crop-weed hybridization. Risks include naturalization, transgene introgression, and the formation of novel genotypes in natural systems. In this study, roadside …

Superfund Evaluation: The Families Of Tar Creek, Gary D. Wilson

Graduate Theses and Dissertations

The Tar Creek Superfund Site is located in far northeastern Oklahoma near the Oklahoma/Kansas border in Ottawa County. The Site generally consists of a forty-square-mile area which is also part of the larger Tri-State Mining District that includes areas of Kansas and Missouri. The Site includes parts of five communities: Picher, Cardin, Quapaw, North Miami, and Commerce in Oklahoma. It also includes Treece, Kansas, and affects a total population of roughly 30,000 residents. Following Superfund designation, families in the Tar Creek area had to decide whether to accept or reject buy-out offers. This project explored the decision-making processes employed by …

The Identification Of Quantitative Trait Loci For Sucrose And Stachyose Content In Soybean Seed, Ailan Zeng

Graduate Theses and Dissertations

Sucrose is a desirable sugar in soybean seed that affects the quality and taste of soyfoods, while stachyose is a non-digestible sugar that induces flatulence in non-ruminant animals. Therefore, soybean cultivars with high sucrose and/or low stachyose would be valuable for soyfood and meal markets. The objectives of this study were to identify quantitative trait loci (QTL) or genes associated with seed sucrose and stachyose content using simple sequence repeat (SSR) or single nucleotide polymorphism (SNP) markers. A low sucrose line, MFS-553, was crossed with a high sucrose plant introduction, PI 243545, to develop the sucrose QTL mapping population. A …

Consumer Sensory Preferences And Willingness-To-Pay For Nutraceutical-Rich Fruit, Lydia Lawless

Graduate Theses and Dissertations

Health-oriented juices are prime candidates for the nutraceutical market due to their inherent healthfulness and convenience. Fruits such as açaí berries, blueberries, blackberries, black cherries, Concord grapes, cranberries, and pomegranates are rich in potentially health-supporting polyphenolics, which makes the juices of these fruits attractive for nutraceutical optimization. The compositional, sensory, and stability properties of blueberry, blackberry, and Concord grape juice blends were explored in an extended shelf-life study. Initially, 100% blueberry juice had the highest total monomeric anthocyanins (67.40 mg/100mL), 100% blackberry juice had the highest total phenolics (249.24 mg/100mL), and 100% Concord juice had the highest polymeric color (23.21%). …

Gendered Effects On The Child Welfare Agency Decision-Making Process, Brandon Crawford

Graduate Theses and Dissertations

Previous research on child abuse and neglect suggests that there may be gendered relationships between child victims and case outcomes. Specifically, although agency practices may generally regard most male and female children as equally vulnerable, agency attributions regarding the culpability, need, and suitability of parents may be highly differentiated based on gender. Explanations for this pattern may lie in the cultural ideologies and organizational beliefs that distinguish between the perceived rights, responsibilities, and relative importance of mothering and fathering roles. That is, one function of Social service agencies is to uphold Social constructions of parenting and promote our larger cultural …

Of Dice And Men: An Ethnography Of Contemporary Gaming Subculture, Christopher Shane Brace

Graduate Theses and Dissertations

Tabletop roleplaying is a dynamic and flourishing hobby that has become increasingly accessible to a wide variety of participants. The games themselves, as well as the gaming subculture, offer players a number of personal and Social benefits that continue to enrich their lives long after they leave the table. Using Goffman's theories of Dramaturgy and Frame Analysis, this paper seeks to examine the positive impact of gaming in three key areas.

The first is an analysis of the subculture which includes the evolution of the games, the growth and diversification of the roleplaying community, and the current shift in stereotypes …

Cell Bioenergetics In Leghorn Male Hepatoma Cells And Immortalized Chicken Liver Cells In Response To 4-Hydroxynonenal Induced Oxidative Stress, Alissa Laura Piekarski

Graduate Theses and Dissertations

Bioenergetic mechanisms responsible for ATP production are essential in carrying out maintenance and cell-specific functions. In this study, hepatocytes (liver cells) were used to test both endogenous and exogenous stress on cellular respiration. The secondary lipid peroxide, 4-hydroxynonenal (HNE), was used because it alters bioenergetics by increasing mitochondrial proton leak that attenuates mitochondrial radical production and, therefore, endogenous oxidative stress. The major objective of this study was to demonstrate effects of HNE-induced oxidative stress on avian hepatocyte bioenergetics. Various chemical which help enable the determination of oxygen (O2) consumption linked to ATP synthesis (oligomycin), maximal O2 consumption (FCCP), and proton …

Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions., Christian Michael Loeschel

Graduate Theses and Dissertations

In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.

Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide …

Yeast Surface Display Of Cd154, Iaryna Masniuk

Graduate Theses and Dissertations

The CD154 (CD40L) is a member of tumor necrosis factor (TNF) family that plays a crucial role in regulation of both cell-mediated and humoral immunity by activating antigen presenting cells (APCs). Previously, studies in the laboratory demonstrated that yeast surface display system allows the expression of biologically functional antigen, such as subunit HA, against influenza virus. Yeast surface display system seems to be an excellent system to be utilized to develop anti-influenza virus vaccine. Thus, it is of interest to study the adjuvant function of CD154 on the subunit HA vaccine against influenza virus. In this project, the CD154 encoding …