Digital Commons Network^™

The Potential Environmental Benefits Of Hybrid Rice Varieties, Haxhire Myrteza

Graduate Theses and Dissertations

With water insufficiency being already a major issue and potential carbon policies on greenhouse gas (GHG) emissions, Arkansas rice producers may need to undergo some changes in regards to rice cultivar selection. The purpose of this study is to estimate the environmental benefits of cultivating hybrid rice varieties as opposed to conventional and Clearfield rice varieties. To accomplish this goal, water use and GHG emissions were estimated on per acre (ac) and per bushel (bu) basis for most commonly cultivated rice varieties in Arkansas. The study focuses particularly on six main rice stations in the State of Arkansas. The hypothesis …

Subsurface Planetary Investigation Techniques And Their Role For Assessing Subsurface Planetary Composition, Ahmed Elshafie

Graduate Theses and Dissertations

Subsurface planetary investigation techniques are of high interest and importance for the scientific community. Not only they can enhance our knowledge of the history of planetary formation but also can lead to information about its future. Whether the investigation is being conducted remotely using imagers, radars or physically using penetrometers or drills, a pre-existed knowledge of the mechanical and electrical properties of the subsurface regolith should be acquired for better data interpretation and analysis. Therefore, the main objective of this work is to investigate the mechanical and electrical properties of planetary analogs, understand their role for assessing the subsurface structure …

Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay

Graduate Theses and Dissertations

The following dissertation describes synthetic efforts toward the synthesis of the C21-C34 fragment of antascomicin B. Our initial enzymatic approach is detailed as well as an asymmetric transfer hydrogenation (ATH) strategy that will be used in the eventual total synthesis of the molecule. Several investigations into anomalies observed during (ATH) reactions are also discussed.

Evaluation Of Internal Markers For Predicting Digestibility And Fecal Output By Cattle Fed Bermudagrass Hays Of Varying Quality, Juvenal Kanani

Graduate Theses and Dissertations

The potential of in situ rumen undegradable dry matter (RUDM), indigestible neutral-detergent fiber (INDF), indigestible acid-detergent fiber (IADF), acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict digestibility (DMD) and fecal output (FO) by cattle fed bermudagrass [Cynodon dactylon (L.) Pers.] hay-diets categorized by their low (L), medium low (ML), medium high (MH), or high (H) CP concentrations (79, 111, 131, and 164 g/kg DM, respectively) was evaluated. The second objective was to evaluate the effects of time (0600, 1200, 1800, and 2400 h) of fecal sampling on the prediction of FO and DMD. A replicated …

Time Waits For No One: Using Time As A Lens In Information Systems Research, Christopher M. Conway

Graduate Theses and Dissertations

Despite considerable research interest, IT projects still fail at a higher rate than other projects. Primary causes for these failures are relational, motivational, and scheduling issues on the team. Using the concept of time as a lens, the four essays in this dissertation examine how the ways that individuals and teams structure time can help explain these failures. The essays formulate the concept of temporal dissonance at the individual and team level, and explore how temporal dissonance causes negative consequences for IT workers and IT teams.

Essay one synthesizes temporal dissonance from concepts of temporal congruity and cognitive dissonance. It …

Water Quality Trends And Nutrient Loads For The Watershed Research And Education Center In Northwest Arkansas, 2009-2012, John Metrailer

Graduate Theses and Dissertations

Nitrogen, phosphorus, and sediment transport is a concern for Northwest Arkansas due to high exports through riverine discharge. Urban, agricultural, and pastured watersheds have been associated with increased N, P, and sediment concentrations when compared to forested catchments. The objective of this study was to evaluate discharge and nutrient loads associated with a small urban, agricultural (row crop), wetland influenced, and pasture/farmland sub-catchment within four ephemeral drainages and located at the Watershed Research and Education Center in Fayetteville, AR. Samples were collected during base flow conditions and periodic storm flow conditions from 2009-2012. Flow adjusted concentration trends were used to …

Genotypic And Phenotypic Diversity Of Pyricularia Oryzae In The Contemporary Rice Blast Pathogen Population In Arkansas, Lu Zhai

Graduate Theses and Dissertations

Rice blast, caused by Pyricularia oryzae (teleomorph: Magnaporthe grisea), is one of the most economically important diseases of rice worldwide, including Arkansas. Rice blast has been severe the past few years on conventional cultivars and, more recently, has been observed on hybrid rice cultivars. The first objective of the current research was to examine the genotypic and phenotypic variation in the P. oryzae population in Arkansas during the 2009, 2010, and 2011 growing seasons and compare isolates from conventional cultivars with those from and hybrids. A total of 904 isolates were recovered from symptomatic rice cultivars in Arkansas and …

The Use Of Diatoms To Infer Environmental Change Of The Lower White River, Southeastern Arkansas, Ruchi Bhattacharya

Graduate Theses and Dissertations

This dissertation describes the limnology of the lower White River oxbow lakes in southeast Arkansas, inundated by the major 2008 spring flood. The flood water and sediment deposited in oxbow lakes were analyzed for water chemistry, sediment geochemistry and diatom assemblages and used as an analogue for past floods. The 2008 spring flood inundated and homogenized the entire floodplain; also represented by the predominantly planktonic diatom assemblage suggesting riverine input. Indicator species for eutrophication were also recorded consistent with the high nutrient content in the lakes. However, the variance in the surface diatom assemblage was best explained by the lake …

Integrating Human Variables In Cross-Boundary Monitoring Of Aberdare Preserves In Kenya, Peter K. Njuguna

Graduate Theses and Dissertations

This research critically examines extant data systems and their linkage of scientific research to policy and public education in east African highland forest conservation preserves. The research indicates that the current state of data and monitoring systems in the region imposes substantial limitations on the ability to manage these preserves. Major outcomes of those constraints manifest in unprecedented cross-boundary pressure such as encroachment and conversion of forest to agriculture, increased human-wildlife conflicts, and constrained relations among primary stakeholders. Current monitoring is biodiversity focused within preserves and fails to capture human dimensions in adjoining areas across preserve boundaries. This study proposes …

Synergy Of Alum And Chlorine Dioxide For Curbing Disinfection Byproduct Formation Potential At Central Arkansas Water, Corey W. Granderson

Graduate Theses and Dissertations

Central Arkansas Water (CAW), the water utility for Little Rock, AR, draws their source water from Lake Maumelle and Lake Winona. To curb disinfection byproduct (DBP) formation, CAW has begun retrofitting their two plants to use chlorine dioxide as an alternative primary disinfectant followed by free chlorine secondary disinfection in the distribution system. In this study, fluorescence parallel factor (PARAFAC) analysis was combined with free chlorine simulated distribution system (SDS) tests and DBP formation potential (DBPFP) tests to study the benefit of chlorine dioxide primary disinfection (CDPD) with alum coagulation. Of the DBPs screened, trichloromethane (TCM) was formed in highest …

Dental Microwear Texture Analysis Of Pliocene Bovids From Four Early Hominin Sites In Eastern Africa: Implications For Paleoenvironmental Dynamics And Human Evolution, Jessica Renee Scott

Graduate Theses and Dissertations

Many researchers have suggested that Plio-Pleistocene climate change was a motive force for human evolution. The basic idea was that a shift toward drier, more open settings, led to adaptations for bipedality and the consumption of savanna resources, including large grazing mammals. However, more recent paleoenvironmental reconstructions suggest that Pliocene hominins occupied variable or mosaic habitats including both open and closed settings. Many techniques have been used to refine our understanding of the paleoenvironments of eastern Africa; however these have not led to consensus reconstructions. At Kanapoi, ecological diversity analysis indicates that at least part of the site was composed …

Establishment Method And Cultural Practice Effects On Sports Turf, Josh Anderson

Graduate Theses and Dissertations

The use of soil-based sod on sand-based rootzones for the establishment of sports fields and golf courses is a common occurrence. Furthermore, the use of soil-based sod on sand-based rootzones can lead to potential problems associated with decreased water infiltration, gas exchange, rooting, and turfgrass quality caused by soil layering. Core-aerification and sand topdressing may help alleviate the problems associated with soil layering from the use of soil-based sod on sand-based rootzones. Therefore, the objectives of this research were to evaluate the effects of sod establishment methods and post- establishment cultural practices on the infiltration rate, moisture content, divot resistance, …

Sanitation Assessment Of Food Contact Surfaces And Lethality Of Moist Heat And A Disinfectant Against Listeria Strains Inoculated On Deli Slicer Components, Sabelo Muzikayise Masuku

Graduate Theses and Dissertations

The overall objectives of this study were to: evaluate the efficacy of different cleaning cloth types and cloth-disinfectant combinations in reducing food contact surface contamination to acceptable levels; determine the optimum moist heat and moist heat + sanitizer treatments that can significantly reduce the number of Listeria strains on deli slicer components; and investigate if the moist heat treatment used in this study induced the viable-but-non-culturable (VBNC) state in Listeria cells. The efficacy of wiping cloths was measured using ATP-bioluminescence and total plate count methods using four different wiping cloths and silver dihydrogen citrate sanitizer on food contact surfaces. The …

Growth Promoting Implants And Nutrient Restriction Prior To Feeding: Effect On Carcass Composition, Carcass Quality, And Consumer Acceptability Of Beef, Jessica Ann Robinette

Graduate Theses and Dissertations

Implant strategy and nutrient restriction prior to finishing may alter feedlot performance, as well as carcass characteristics and consumer acceptability of beef. The objectives of these studies were to determine the effect of prefinishing implant strategy and plane of nutrition on prefinishing and feedlot performance, carcass characteristics and quality, and consumer acceptability of beef. In 2 experiments, spring-born calves were weaned in the fall (Exp. 1, n =120; and Exp. 2, n = 96) and were either finished as calves (CALF-FED) or placed on a growing program with a target ADG of 0.45 kg/d (RSTR) or 0.91 kg/d (UNRSTR) before …

Aptamer-Based Spr Biosensor For Detection Of Avian Influenza Virus, Hua Bai

Graduate Theses and Dissertations

Rapid and specific detection of avian influenza (AI) virus is urgently needed with the concerns over the outbreaks of highly pathogenic H5N1 avian influenza in animal and human infection. Aptamers are artificial oligonucleic acid that can specifically bind to target molecules. They show comparable affinity for target virus and better thermal stability than monoclonal antibodies. Those advantages make aptamers promising candidates in diagnostic and detection applications. The goal of this research was to use DNA&ndashaptamer as the specific recognition element in a portable surface plasmon resonance (SPR) biosensor for detection of AI H5N1 virus in poultry.

A SPR biosensor was …

Identification And Confirmation Of Ssr Markers And Qtl For Seed Calcium Content And Hardness Of Soybean, Moldir Orazaly

Graduate Theses and Dissertations

The health benefits and the nutritional values of soyfood products have expanded the demand for food-grade soybean varieties. For whole soyfood products such as natto, small seeded varieties with proper texture are essential. Seed calcium content and hardness are main factors in determining the seed texture. Utilizing molecular markers associated with quantitative trait loci (QTL) for marker assisted selection (MAS) has been an efficient technique for breeders. To find molecular markers associated with a trait is an initial step. The confirmation of QTL in different environments and in different genetic backgrounds is important for MAS. The objectives of this research …

Investigation Of A Locus On Chromosome 9 For Contributions To Pulmonary Hypertension Syndrome In Broilers, Sriram Krishnamoorthy

Graduate Theses and Dissertations

Although the ascites syndrome in chickens has been investigated for years, it continues to inflict financial losses to the world poultry industry. It is estimated that 8% of the 361 million broiler deaths are due to ascites leading to losses of millions of dollars annually. Efforts to curb the incidence of ascites are typically designed to slow early growth. This limits the birds' ability to show its true genetic potential and impacts later yields. In 1994 lines divergent for susceptibility to ascites were established from a commercial sire line through sibling selection of birds reared at local altitude after testing …

Effect Of Enzymatic Treatments On The Physiochemical Properties Of Different Corn Starches, Curtis Robert Luckett

Graduate Theses and Dissertations

Amylose readily reassociates to form films and crystalline structures that are resistant to digestion by amylolytic enzymes and known as resistant starch type III (RS3). This study investigated the RS3 formation and cereal coating properties from enzyme-modified corn starches with varying amylose contents, including Hylon VII (70% amylose), Hylon V (50% amylose), and common corn (25% amylose). For RS3 formation, corn starches were first gelatinized and then hydrolyzed using β-amylase to varying degrees. The resultant hydrolyzed starch was debranched with isoamylase and then exposed to 3 times of temperature cycling at 135/133/133°C for 30 min and 95°C for 24 hr …

Genetic Analysis Of Chromosomal Regions Affecting Sperm Mobility In The Chicken (Gallus Gallus Domesticus), Sharath Chandra Munnaluri

Graduate Theses and Dissertations

This project is focused on determining the contributions of particular genetic loci to low sperm mobility in the chicken. Sperm mobility has been shown to be a major determinant of male fertility in broiler breeders. A whole genome SNP scan identified chromosomal regions (QTLs) that control sperm mobility. I used microsatellites from 4 chromosomal regions ( 15.151 on chromosome 6, 12.435 on chromosome Z, 12.341 on chromosome Z, and 17.214 on chromosome Z) to determine the association of these regions with sperm mobility in experimental lines divergently selected for mobility phenotype. Determination of the genetics underlying sperm mobility will identify …

Stable Isotope Analysis (Delta Nitrogen-15 And Delta Carbon-13) And Bioenergetic Modeling Of Spatial-Temporal Foraging Patterns And Consumption Dynamics In Brown And Rainbow Trout Populations Within Catch-And-Release Areas Of Arkansas Tailwaters, Jon M. Flinders

Graduate Theses and Dissertations

I examined spatial and temporal consumption dynamics using an energy intake model and a bioenergetics model of rainbow trout, Oncorhynchus mykiss, and brown trout, Salmo trutta, within three catch-and-release (C-R) areas in Bull Shoals and Norfork tailwaters to determine whether trout populations were limited by food supply. I also examined the seasonal and ontogenetic shifts in the foraging patterns of brown and rainbow trout within these areas using gut content analysis (GCA) and stable isotope analysis (SIA) of C and N. I examined 605 brown trout and 768 rainbow trout for GCA and SIA at Bull Shoals, Norfork, …

Mathematical Modeling Of Fluid Spills In Hydraulically Fractured Well Sites, Oluwafemi Michael Taiwo

Graduate Theses and Dissertations

Improved drilling technology and favorable energy prices have contributed to the rapid pace at which the exploitation of unconventional natural gas is taking place across the United States. As a natural gas well is being drilled, reserve pits are constructed to hold the drilling fluids and other materials returned from the drilling process. These reserve pits can fail, and when they do, plant and animal life of the surrounding area may be adversely affected. This project develops a screening tool for a suitable location for a reserve pit. This work will be a critical piece of the Infrastructure Placement Analysis …

Modern Modesty: The Renegotiation Of Female Pious Dress In Modern Pentecostal Assemblies, Amanda Beth Phillips

Graduate Theses and Dissertations

Hair buns, high necklines, long sleeves, ankle length skirts, and simple yet practical work style shoes have exemplified Pentecostal women's dress throughout the history of the movement. Their bodies fervently protected from impropriety and immorality, through prescribed attire, are the sites upon which the church inscribes its vision of the modest Pentecostal woman. How dress is used within the community to `set apart' those assembly members whom have achieved the appropriate holiness lifestyle not only makes them upstanding members of the church assembly but also defines them as `saints' (sanctified ones, holy assembly members) and helps to develop their relationship …

Worry Induction Among Adolescents: A Laboratory Evaluation, Jamie Leigh Frala

Graduate Theses and Dissertations

Available research indicates that worry is an important process involved in the development and maintenance of both psychological (e.g., Generalized Anxiety Disorder) and physical (e.g., coronary heart disease) problems. However, this process is still in need of further investigation, particularly among adolescents. While a sizable body of literature has examined the nature, prevalence, and correlates of worry in both adults and youth, laboratory investigations of this variable using a real-time worry induction paradigm have previously only been done with adults. The current study aimed to extend the literature by using the controlled laboratory methods well established in the adult literature …

Interactions Of Nitric Oxide And Superoxide Pathways In Hyperglycemic Endothelial Cells, Steven Clay Rogers

Graduate Theses and Dissertations

Cardiovascular complications arising from diabetic hyperglycemia represents one of the leading causes of death and greatest public health challenges of modern societies. Despite state-of-the-art glucose control, diabetic patients remain at a markedly increased risk of cardiovascular disease. The loss of endothelial function (the development of diabetic endothelial dysfunction) has been implicated in the development of numerous diabetic cardiovascular diseases. The endothelial cell produces many vasoactive substances, hormones and cytoprotective biological factors. Endothelial cells are also involved in and affected by the initiation of inflammatory responses through the release and interaction of cytokines and other immune system molecules. Therefore, regulation of …

Electrospun Polycaprolactone Nanofiber Scaffolds For Tissue Engineering, Andreas Haukas

Graduate Theses and Dissertations

Stem cell and tissue engineering offer us with a unique opportunity to research and develop new therapies for treating various diseases that are otherwise incurable using traditional medicines. However, development of these new therapies replies upon the establishment of in vitro cell culture and differentiation systems that mimic in vivo microenvironments required for cell-cell and cell-ECM interaction. The development of these cell culture systems depends upon the identification of appropriate biomaterials and cell sources. Biomaterials should be carefully selected and fabricated into scaffolds for supporting cell growth and differentiation. In this study, we explored the fabrication of 3D electrospun nanofiber …

The Effect Of Weighting Development Indicators On Countries Eligibility For International Development Funding: The Case Of The Millennium Challenge Corporation (Mcc), Idrissa Noma

Graduate Theses and Dissertations

The Millennium Challenge Corporation (MCC) is a U.S. government agency whose purpose is to promote economic growth and reduce poverty in low and low middle-income countries. It uses indicators to endorse countries eligibilities for international development funding. These indicators are related to economic growth and are developed by independent third parties (e.g., United Nations, World Bank), to evaluate a country's policy performance in three specific areas: (1) Ruling Justly, (2) Investing in People, and (3) Encouraging Economic Freedom (MCC, 2011). The MCC weighs indicators equally regardless of their myopic in-country relevancy to economic development. The goal of this study is …

Utilization Of Natural Green Tea And Grape Seed Extracts And Nisin To Reduce Conventional Chemical Preservatives And To Inhibit The The Growth Of Listeria Monocytogenes In Ready To Eat Low And High Fat Chicken And Turkey Hotdogs, Amara Venkata Sunil Perumalla

Graduate Theses and Dissertations

Ready-to-eat meat (RTE) products such as hotdogs represent a popular segment in convenience food purchases. Increased demand has led the processors to extend the shelf life by minimizing lipid oxidation and post-processing contaminants such as Listeria monocytogenes. There is a growing interest in the food processors and consumers regarding the use of natural alternatives in place of synthetic food additives to control the growth of foodborne pathogens and (or) lipid oxidation. In recent years, green tea (GTE) and grape seed extracts (GSE) are increasing choices as they have demonstrated antioxidant as well as antimicrobial properties in various food applications. …

Anxiety And Sleep Disorder Comorbidity: Affecting The College Students' Performances, Amanda Rhenee Grimes

Graduate Theses and Dissertations

The purpose of this study is to determine the effects that anxiety disorders and sleep disorders have on students' academic performance. The prevalence of both disorders is rising in the college student population. This study examines those who have been physician diagnosed with the one or both of the disorders and how the students' grade point average (GPA) is affected.

The National College Health Assessment was used for data collection; this survey assesses college students' health habits, behaviors, and perceptions. The sample was comprised of 57 institutions representing every region in the U.S. totaling 34,208 participants. Data was acquired through …

Development Of A Microfluidic Device Coupled To Microdialysis Sampling For The Pre-Concentration Of Cytokines, Randy Francisco Espinal Cabrera

Graduate Theses and Dissertations

A proof-of-concept microfluidic device combined with heparin-immobilized magnetic beads was created to concentrate cytokine proteins collected from microdialysis samples. Cytokines are known to be related to several diseases such as cancer, and Parkinson's diseases, so to be able to develop more effective diseases treatments their interactions have to be well understood. Amine-functionalized polystyrene and carboxyl-functionalized magnetic microspheres of ~6.0 ìm in diameter were used to immobilize heparin. The amount of heparin immobilized on polystyrene beads was 5.82 x 10-8 ± 0.36 x 10-8 M per 1.0 x 106 beads and for magnetic beads was 0.64 x 10-8 ± 0.01 x …

A Family Affair: The Pre-Kansas Saga Of James Henry Lane, James Robert Bird

Graduate Theses and Dissertations

Historian Craig Miner suggests that territorial Kansas between 1854 and 1861 was "a nursery of weird and manic figures." Foremost among the weird and manic figures of Kansas history stands James Henry Lane, formerly a U.S. congressman from Indiana, and destined to become one of Kansas' first pair of senators. Writing at the midpoint of the twentieth century, Albert Castel pronounced Jim Lane "the most colorful and fascinating personality in the history of Kansas," adding that "Very likely, too, he was mentally unbalanced and paranoid."

Yet, James H. Lane never set foot on Kansas soil until he was well into …