Digital Commons Network^™

Distribution And Control Of Glyphosate-Resistant Johnsongrass (Sorghum Halepense) In Arkansas Soybean, Dennis Brent Johnson

Graduate Theses and Dissertations

Johnsongrass, once the most persistent and troublesome grass weed of row crops throughout the southern U.S., has previously been confirmed resistant to the acetolactate synthase (ALS) and acetyl-coenzyme A carboxylase-inhibiting herbicides in the Midsouth and has recently evolved resistance to glyphosate in Arkansas. The goal of this research was to establish the geographical distribution of herbicide-resistant johnsongrass in Arkansas and to develop herbicide programs for controlling glyphosate-resistant johnsongrass in Arkansas soybean. Johnsongrass accessions were collected from 14 counties in the Mississippi River Delta region of Arkansas and screened for resistance to four of the most commonly used postemergence herbicides for …

Abiotic And Biotic Factors Affecting The Japanese Beetle In Arkansas, Bryan Mathew Petty

Graduate Theses and Dissertations

Japanese beetles are a relatively new pest to Arkansas. During my Ph.D. research I investigated the pathogens and environmental factors influencing Japanese beetle populations in the state. The prevalence of various pathogens and parasitoids attacking Popillia japonica were recorded annually from wild populations. Of specific interest was the microsporidian pathogen Ovavesicula popilliae, which I introduced as a biological control agent in the state. Details of the relationship between this pathogen and the Japanese beetle were investigated, including dose response, host range, and spore production. Additionally, annual abundance of the beetle in the region was recorded and tracked over the course …

Development Of Rapid Detection Methods And Novel Control Measures For Salmonella In Poultry, Si Hong Park

Graduate Theses and Dissertations

This dissertation consists of three research parts: 1) development of rapid detection methods for foodborne pathogens; 2) immune response of chicken cells against Salmonella and bacteriophage P22; 3) evaluation of novel control measures for poultry productions. In order to develop rapid and accurate detection methods for foodborne pathogens, two types of PCR assays were utilized. Three foodborne pathogens included Campylobacter, Escherichia coli and Salmonella in watershed were qualitatively and quantitatively detected by multiplex PCR and qPCR (chapter 2). Since Salmonella species are commonly present in poultry and poultry products as well as most popular foodborne pathogen in …

The Impact Of Parent Education On Parental Feeding Practices, Larra Kolby Brawley

Graduate Theses and Dissertations

This research looked at the potential impact that parent education may have on the feeding practices of parents of young children. Since eating behaviors are a national concern for both children and adults, it's important to examine how we can create not just healthier children but, as a result, healthier adults. This study utilized an intervention that was an adapted version of a healthy eating curriculum created by Sesame Workshop and the California WIC association with the intention of improving parental feeding practices through a behavior-based approach. Previous research with this curriculum has addressed only low-income populations, with a relatively …

Visual And Linguistic Influences On Public Perceptions Of Swine Confinement, Arthur Leal

Graduate Theses and Dissertations

This study was designed to analyze the visual and linguistic characteristics of online (YouTube) videos and electronic newspapers, identifying relationships with positive, negative, and neutral attitudes toward swine confinement.

This study followed a content analysis design. Two coders, trained to an acceptable level of agreement (κ = .68), examined online videos and electronic newspapers, assessing linguistic and visual images used in relation to attitudes toward swine confinement. A series of search terms deemed suitable for this study's objectives were employed in multiple search engines, and 48 articles and 157 videos were coded for content.

Results from this study showed that …

Design And Evaluation Of A Fiber Optic Probe As A Means Of Subsurface Planetary Exploration, Robert Paul Pilgrim

Graduate Theses and Dissertations

The Optical Probe for Regolith Analysis (OPRA) is an instrumentation concept designed to provide spectroscopic analysis of the near subsurface of unconsolidated regolith on bodies such as moons, asteroids and planets. Below a chemically altered surface may lay the geological history in the form of stratigraphy that is shielded from degradation due to harsh external environments. Most of what we know about our solar system comes from remote platforms, such as satellites that are deployed into orbit around the target body. In the case of Mars, we have had several successful landers and rovers however, with the exception of the …

Study Of Thermotolerance Mechanism In Gossypium Hirsutum Through Identification Of Heat Stress Genes, Jin Zhang

Graduate Theses and Dissertations

ABSTRACT

Heat stress causes major losses to cotton seed and lint yield. Introduction of heat stress tolerance to Arkansas cotton varieties is highly desirable. However, very little is known about the molecular basis of heat stress tolerance in cotton. The present study attempted to identify heat stress tolerance genes in two heat-tolerant cotton cultivars, VH260 and MNH456, originating from Pakistan. Towards this, the expression profile of the cotton orthologs of sevenArabidopsisheat stress tolerance genes was studied in these two cultivars, and compared with the two heat-susceptible cotton cultivars, ST213 and ST4288, originating from Mississippi Delta region. In addition, physiological parameters …

Comparison Of Potential Salmonella Portals Of Entry And Tissue Distribution Following Challenge Of Poultry, Gopala Krishna Kallapura Sheshagiri

Graduate Theses and Dissertations

The following studies evaluated our hypothesis that transmission by the fecal-respiratory route may be a viable portal of entry for Salmonella and could explain some clinical impressions of relatively low-dose infectivity under field conditions in relation to the requisite high oral challenge dose that is typically required for infection of poultry through the oral route in laboratory studies. Initial field reports indicating tracheal sampling to be a sensitive tool for monitoring Salmonella infection in commercial flocks, suggested that tracheal contamination could be a good indicator of Salmonella infection under commercial conditions. Further, a usual assumption regarding airborne Salmonella reaching the …

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Graduate Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made …

Evaluation Of Water Sanitation Options For Poultry Production, Pramir Maharjan

Graduate Theses and Dissertations

An evaluation of poultry farm water supplies was conducted to determine the value and impact of water system sanitation practices in commercial broiler houses on microbial levels. Water line cleaning between flocks using concentrated disinfectant solution before placing chicks reduced biofilms retained in the lines to a safe level. Occasional microbial surges were noticed during different points of flock grow-out period even when daily water sanitation was present indicating water is highly susceptible to microbial contamination. However, the daily water sanitation practice controlled the occasional microbial surges in water from sustaining and kept drinking water to a microbiologically acceptable level. …

Decoding Literary Aids: A Study On Issues Of The Body, Masculinity, And Self Identity In U.S. Aids Literature From 1984-2011, Alexander Shimon Abrams

Graduate Theses and Dissertations

Rather than waiting decades to respond, novelists of nearly every literary genre began conceptualizing the AIDS epidemic shortly after the first documented case of the virus in the United States in 1981. Writers, feeling a sense of urgency, wasted little time constructing didactic texts that differ from much historical fiction in that they were written as the tragedy they are commenting on occurred. However, AIDS literature has changed as the disease has spread well beyond the gay communities of San Francisco and New York, causing people to reexamine their longstanding beliefs on masculinity, sexuality, and body politics.

My Master's thesis …

On The Permanence Of Heideggerian Authenticity, Seth Daves

Graduate Theses and Dissertations

In this essay I pose the following question: is Heideggerian authenticity permanent? To investigate this question I begin with a thorough analysis of what Heidegger means by authenticity. Afterwards I look into the leading figures within the field, seeking guidance in answering the question of the permanence of Heideggerian authenticity. Ultimately I conclude that an amended version of John Haugeland's analysis of resoluteness gives rise to the affirmative response to my question. I conclude by investigating potential problems concluding that Heideggerian authenticity is permanent.

Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker

Graduate Theses and Dissertations

For every ten kilograms of biodiesel that is produced from the transesterification of vegetable oil, approximately 1 kg of glycerol is produced as a byproduct. Also known as glycerin, it is a chemical used in many products including cosmetics, foods, and desiccants. However, the crude glycerol created during biodiesel production is tainted with potassium hydroxide and methanol making it unsuitable for commercial use without costly refinement. With increase in production of biodiesel driven by rising fuel prices, the market has become glutted with glycerol and it is on the threshold of becoming a waste product. Common methods for disposing glycerol …

Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith

Graduate Theses and Dissertations

Cow-calf producers in the Ozark Highlands region are under continuous pressure to improve economic efficiency. Additionally, estimating greenhouse gas (GHG) emissions from cow-calf and forage production processes may become increasingly important as policy makers seek to mitigate or reduce agriculture's role in climate change. As such, this analysis had three objectives. Objective 1: Provide a model that could be used by cow-calf producers, extension agents, and researchers to evaluate GHG and net return (NR) repercussions when modifying site characteristics, production methods, and inputs. Objective 2: Develop a user guide such that the methodology for estimating cow-calf GHG emissions and NR …

Using The Ceres-Maize Model To Create A Geographically Explicit Grid Based Estimate Of Corn Yield Under Climate Change Scenarios, Ryan Zachary Johnston

Graduate Theses and Dissertations

The CERES-Maize model was evaluated in its capacity to predict both regional maize yield and water use within the United States Department of Agriculture (USDA) Economic Research Service (ERS) Region 1 between the years 1997-2007. A grid based, geospatially explicit method was developed to express the various rainfed and irrigated maize cultivars grown across the region. Overall, the calibrated model compared well for both physiological and yield parameters, producing significant linear relationships (p

The calibrated and validated CERES-Maize model was used to predict potential evapotranspiration and yield under three IPCC weather scenarios for the year 2050 to evaluate crop production …

Initial Fine Mapping Of The Spinach Downy Mildew Resistance Locus Rpf1, Wei Yang

Graduate Theses and Dissertations

Spinach is an important vegetable crop grown in many parts of the world (Correll et al. 2011). It has become increasingly popular due to its nutritional value as it is very high in antioxidants (Prior, 2003). Spinach production, however, is affected by many biotic stresses. Downy mildew, caused by Peronospora farinosa f. sp. spinaciae (Pfs) , is perhaps the most important biotic constraint for spinach production worldwide (Correll et al, 1994). As of 2012, 14 races of Pfs have been reported (Correll et al., 2011). The rapid increase of new races is likely a direct result of substantial changes in …

Morphological And Molecular Taxonomic Identification And Phylogenetics Of Criconematoidea, Marco Cordero

Graduate Theses and Dissertations

The superfamily Criconematoidea has been studied since 1886. It is composed of two families: Criconematidae (subfam. Criconematinae, Hemicycliophorinae) and Tylenchulidae (subfam. Tylenchulinae, Paratylenchinae and Tylenchocriconematinae). Multiple species in genera have been identified and differences and similarities have been found. Species belonging to genera Mesocriconema and Criconemoides show very few differences making their identification difficult. Seventy two populations were studied. They were collected in Arkansas and/or received from the following states: California, Florida, Kansas, Missouri, North Carolina and Tennessee. Populations of the following species were identified: Mesocriconema curvatum, M. kirjanovae, M. onoense, M. ornatum, M. sphaerocephala, M. surinamense, M. vadense, M. …

Tethered, Samantha Jean Dixon

Graduate Theses and Dissertations

Tethered addresses the innate fear of forgetting where an individual's family originates, both physically and historically. Not long after discovering that part of my family was almost completely annihilated during the Holocaust, I produced Tethered as visual documentation of the long-term effects of families of survivors. The exhibition is also influenced by my grandmother's experiences as a Mauthausen concentration camp survivor and my own experiences being raised by a survivor.

The knowledge of the imminent loss of memory initiates an instinct to repetitively record and remember personal history. Numerous memories have been forcefully buried in the darkest recesses of the …

Cycle, Nichole Annette Howard

Graduate Theses and Dissertations

Cycle is the exhibition of a year-long project that experiments with growing food and medicinal herbs. Alongside an exploration of plant growth, I transfer iconic cultural objects of daily life from plastic to ceramics. Using material culture as a physical and conceptual platform, this re-contextualization of objects offers a radically different view of use and meaning. I transform the soda-filled, plastic Big Gulp cup into a terra planter filled with new life.

My working method involves making molds of Big Gulp plastic cups and transferring the form into a traditional plant growing material, terra cotta. I then germinate seeds inside …

Studies On The Structure And Pathogens Of The Small Hive Beetle (Coleoptera: Nitidulidae), Natasha A. Wright

Graduate Theses and Dissertations

The small hive beetle (Aethina tumida, SHB) is an invasive pest of honey bee (Apis mellifera) colonies in the United States. The adult and larval beetles can ruin honey through fecal contamination and by vectoring a mutualistic yeast (Kodamaea ohmeri) that causes honey fermentation. These beetles also impact honey bee colonies by feeding on bee eggs, bee brood, and pollen. Severe beetle infestations can cause colonies to decline or abscond.

The SHB has been present in the United States since at least 1998. Since then, there have been several published papers on how to successfully rear these beetles. Laboratory rearing …

Narrative Framing Of U.S. Military Females In Combat: Inclusion Versus Resistance, James Scott Herford

Graduate Theses and Dissertations

This study utilizes discursive data to examine how the strategic use of narratives inform policies that shape women's participation in military service overall and more specific, the current controversy over exclusion of women from participation in combat roles within the U.S. military. Specifically, I examine popular military newspapers, blogs and the Department of Defense 2012 Report regarding policies and regulations of female service members. In this study, I provide a sociological analysis of current military-cultural narratives and the institutional narrative discussing women's participation in combat roles in order to provide evidence of the current threat to the military form of …

Physiological Effects Of Low Mowing Heights, Rolling, And Foot Traffic On Creeping Bentgrass Putting Greens, Joseph Ronald Young

Graduate Theses and Dissertations

Golf course superintendents are managing creeping bentgrass (Agrostis stolonifera L.) putting greens throughout the transition zone where temperatures can exceed optimum levels for consecutive days in the summer. The stress of creeping bentgrass associated with these supraoptimal temperatures has been well documented, but the management practices implemented on putting greens to increase green speeds may exacerbate these environmental stresses. To date, the physiological effects of these management practices in combination have not been evaluated for putting green turf. The objective of this dissertation project was to determine the effect of mowing heights, light-weight rolling, and foot traffic on performance and …

Ccaat-Binding Factor As A Transcriptional Regulator Of Cyc1 In Candida Albicans, Carmen S. Padilla-Marcia

Graduate Theses and Dissertations

Candida albicans is a normal commensal of the human flora; however, under appropriate circumstances this organism can become pathogenic to the host and cause life threatening conditions. In fact, Candida species are the fourth most common nosocomial infection in the Unites States with a mortality rate of over 30%

The CCAAT binding factor is a multi-protein transcription factor highly conserved in eukaryotes. It binds specifically to the consensus sequence 5'-CCAAT-3' in promoters and it is one of the most common cisacting elements in eukaryotes promoters. This transcription factor is composed of three DNA binding subunits; Hap2p, Hap3p and Hap5. In …

Agricultural Production And Stability Of Settlement Systems In Upper Mesopotamia During The Early Bronze Age (Third Millennium Bce), Tuna Kalayci

Graduate Theses and Dissertations

This study investigates the relationship between rainfall variation and rain-fed agricultural production in Upper Mesopotamia with a specific focus on Early Bronze Age urban settlements. In return, the variation in production is used to explore stability of urban settlement systems. The organization of the flow of agricultural goods is the key to sustaining the total settlement system.

The vulnerability of a settlement system increases due to the increased demand for more output from agricultural lands. This demand is the key for the success of urbanization project. However, without estimating how many foodstuffs were available at the end of a production …

Influence Of Horn Flies And Breed Type On Milk Production, Calf Production Traits, Pasture Behavior, And Temperament Measurements In Beef Cattle, Angela Rene Mays

Graduate Theses and Dissertations

An experiment conducted in El Reno, Oklahoma during the fly season (May - September/October) evaluated the effects of horn flies on milk production, calf performance, and pasture behavior and temperament measurements of beef cow calf pairs. Cows (n = 53) sired by Bonsmara (BONS; n = 7), Brangus (BRAN; n = 13), Charolais (CHAR; n = 8), Gelbvieh (GELV; n = 5), Hereford (HERF; n = 12), and Romosinuano (ROMO; n = 8) from Brangus dams and their Angus sired calves (n = 51) were used in the study. Horn fly counts (HFC) and milk yield and quality estimates were …

Interactions Between Ions And Lysenin Nanochannels And Their Potential Applications As Biosensors, Radwan Awwad Al Faouri

Graduate Theses and Dissertations

Lysenin is classified as a pore-forming toxin protein that is isolated from the earthworm Eisenia fetida and consists of 297 amino acids [1]. Lysenin inserts large conducting pores (3.0-4.7 nm in diameter) into artificial membranes (BLM) which include sphingomyelin. These pores (channels) are open and oriented upon insertion into the bilayer lipid membrane. Lysenin channels gate at positive voltages (voltage-induced gating), but not at negative voltages. Lysenin pores also exhibit activity modulation in response to changes in ionic strength and pH, indicating that electrostatic interaction is responsible for Lysenin conductance activities. In this line of inquiries, and by modulating Lysenin …

Does Emotion Invalidation Cause Emotion Dysregulation? Evidence From A Healthy Sample Of College Students And Implications For The Development Of Borderline Personality Disorder, Melissa Jean Zielinski

Graduate Theses and Dissertations

Linehan's BioSocial theory is a widely accepted model of the development of borderline personality disorder (BPD). However, the tenet that experiences of invalidation causally influence the development of the emotion dysregulation that characterizes BPD has been subject to relatively little empirical attention. The purpose of this study thus was to experimentally investigate the effects of validation and invalidation on indices of emotion dysregulation including self-invalidation, distress tolerance, and Social problem solving. The current study used a laboratory-based emotion induction procedure in which ninety college students participated in validating or invalidating conversations about emotional events with a peer confederate. Contrary to …

Development Of A Pdms Based Micro Total Analysis System For Rapid Biomolecule Detection, Balaji Srinivasan Venkatesh

Graduate Theses and Dissertations

The emerging field of micro total analysis system powered by microfluidics is expected to revolutionize miniaturization and automation for point-of-care-testing systems which require quick, efficient and reproducible results. In the present study, a PDMS based micro total analysis system has been developed for rapid, multi-purpose, impedance based detection of biomolecules. The major components of the micro total analysis system include a micropump, micromixer, magnetic separator and interdigitated electrodes for impedance detection. Three designs of pneumatically actuated PDMS based micropumps were fabricated and tested. Based on the performance test results, one of the micropumps was selected for integration. The experimental results …

Extraction And Purification Of Gamma-Tocotrienol From Rice Bran Oil Deodorizer Distillate, Mary Kordsmeier

Graduate Theses and Dissertations

The tocols (alpha-, beta-, gamma- and delta- tocopherols (T); alpha-, beta-, gamma- and delta-tocotrienols (T3)) make up the vitamin E family of antioxidants. Tocols have many health benefits. Gamma-T3 has been shown to protect against harmful radiation effects in mice. During rice bran oil refining up to 90% of tocols in rice bran are lost to the deodorizer distillate. The objective of this study was to optimize parameters for analyzing and isolating tocols from rice bran oil deodorizer distillate (RBODD). NP-HPLC analysis of tocol standards was optimized by testing ten mobile phases. Tocol extraction was optimized by testing three concentration …

Design And Fabrication Of Nanofluidic Systems With Integrated Sensing Electrodes For Rapid Biomolecule Characterization, Taylor Bradley Busch

Graduate Theses and Dissertations

A transparent nanofluidic system with embedded sensing electrodes was designed and fabricated by integrating Atomic Force Microscopy (AFM) nanolithography, Focused Ion Beam (FIB) milling and metal deposition, and standard microfabrication processing. The fabrication process started with the evaporation of chrome/gold (Cr/Au) onto a Pyrex 7740 wafer followed by photolithography and wet etching of the microchannels. The wafer was patterned a second time to form Au microelectrodes with 15-45 micrometer separation gaps in the nanochannel region. Sensing electrodes (up to one micron wide) were then deposited using FIB to bridge the gaps. The nanochannels were realized through both AFM nanolithography and …