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Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs

Graduate Theses and Dissertations

Switchgrass (Panicum virgatum L.) has been identified as a model bioenergy feedstock crop and is expected to become an important feedstock for future renewable fuel generation. Agronomic management combinations that maximize monoculture switchgrass yield are generally well understood; however, little is known about corresponding effects of differing switchgrass management combinations on near-surface soil properties. The objective of this research was to determine the residual near-surface soil property effects of three years (2008 to 2011) of consistent management combinations to maximize switchgrass biomass production, including cultivar (‘Alamo’ and ‘Cave-in-Rock’), harvest frequency (1-cut and 2-cut systems per year), fertilizer source (poultry …

Jeane Kirkpatrick And Neoconservatism: The Intellectual Evolution Of A Liberal, Bianca Joy Rowlett

Graduate Theses and Dissertations

Dr. Jeane J. Kirkpatrick, a leading voice in the neoconservative movement, is best known for her articulation of the Kirkpatrick Doctrine, distinctions between authoritarian and totalitarian regimes that served as the foundation for the Reagan Administration's Latin American policies. Her prominence within the neoconservative movement, her impact on foreign affairs, and her political accomplishments in a masculine environment make her an important historical figure in recent American domestic and diplomatic history. This work explores her transition from liberal democrat to neoconservative by examining her early life and educational background, her publications and critiques of American diplomacy in the 1970s, along …

Antibacterial Activity Of Commercially Available Plant Extracts On Selected Campylobacter Jejuni Strains, Divya Oppath Sivasankaran

Graduate Theses and Dissertations

Campylobacter jejuni is recognized as a leading cause of foodborne illness worldwide with approximately 850,000 cases per year in the United Sates. A total of 18 species of Campylobacter have been identified worldwide to date. Foodborne transmission of C. jejuni is mainly through the consumption of unpasteurized milk, contaminated poultry meat and water. C. jejuni can survive in very diverse environments under stressful conditions in human and animals which is different from the specific conditions and media required in laboratory experiments. There has been increased research in recent years to identify naturally occurring antibacterial agents to control and eliminate C. …

Carbon Dioxide Emissions From Switchgrass And Cottonwood Grown As Bioenergy Crops In The Lower Mississippi Alluvial Valley, Michele Lea Helton

Graduate Theses and Dissertations

Marginal land of the Lower Mississippi Alluvial Valley (LMAV) has the potential to be utilized for the production of bioenergy feedstocks. Soil respiration is the gaseous emission of carbon dioxide (CO₂) from microbes and plant roots in the soil, and these emissions play an important role in the global cycling of carbon. Soil respiration can act as a positive feedback affecting climate change, and has been shown to vary depending on soil moisture, temperature, and vegetation. The objectives of this study where to evaluate the effects of land use [switchgrass (Panicum virgatum), cottonwood (Populus deltoides …

Photoelectric Characterization Of Bacteriorhodopsin Reconstituted In Lipid Bilayer Membrane, Joel Kamwa

Graduate Theses and Dissertations

The objective of this work was to conduct basic research in biologically inspired energy conversion solutions. A photosynthetic protein (Bacteriorhodopsin) was reconstituted in a bi-layer membrane. Then, when a laser beam was shined on the membrane, the photon energy was used by the protein to pump protons across the membrane. The translocation of protons across the membrane was measured as photocurrent. For this purpose, a system was built to characterize the lipid bilayer membranes and to measure the photocurrent. The lipid bilayer membrane was characterized by its capacitance and resistance. A picoampere photocurrent was observed when Bacteriorhodopsin protein was present …

Effects Of Water Column P-Availability And Litter Microbial Mediated Processes And Stoichiometry In Aquatic Systems, Ayla Smartt

Graduate Theses and Dissertations

Anthropogenic nutrient enrichment of aquatic ecosystems is prevalent and can have detrimental effects on biological condition. Many of these effects have been attributed directly or indirectly to changes in autotrophic processes. However, in detrital-based streams changes in course detrital stoichiometry and decomposition have been related to changes community structure and production at higher trophic levels highlighting the importance of considering the heterotrophic microbial responses to enrichment. Leaf litter stoichiometry, which is determined in part by the tree species source and the microbial communities that comprise the associated biofilm, is likely related to decomposition rates, but few studies examine these variables …

Metal Assisted Nanowire Growth For Silicon Nanowire/Amorphous Silicon Composite Solar Cell, Asmaa Ali Sadoon

Graduate Theses and Dissertations

Solar cells are photovoltaic devices that convert the energy of light to electricity by the photovoltaic effect. Crystalline silicon-based solar cells are the most dominant solar cells in the market today due to the high efficiency and relatively low cost. However, the cost of such solar cell is still high due to the large amount of material that is consumed in fabricating such a device. Polycrystalline/amorphous thin films and nanomaterial technologies have emerged to reduce the high cost of c-Si based solar cells and increase the efficiency. In this research, we combined these two technologies to propose and fabricate silicon …

Atom-Based Geometrical Fingerprinting Of Conformal Two-Dimensional Materials, Mehrshad Mehboudi

Graduate Theses and Dissertations

The shape of two-dimensional materials plays a significant role on their chemical and physical properties. Two-dimensional materials are basic meshes that are formed by mesh points (vertices) given by atomic positions, and connecting lines (edges) between points given by chemical bonds. Therefore the study of local shape and geometry of two-dimensional materials is a fundamental prerequisite to investigate physical and chemical properties. Hereby the use of discrete geometry to discuss the shape of two-dimensional materials is initiated.

The local geometry of a surface embodied in 3D space is determined using four invariant numbers from the metric and curvature tensors which …

Nutrition Knowledge Of High School Senior Students In Northwest Arkansas, Grace Heymsfield

General Human Environmental Sciences Undergraduate Honors Theses

Numerous changes in school environment regarding nutrition have been implemented in Arkansas, but there is no means in place of testing nutrition curriculum effectiveness in terms of nutrition knowledge of students. High school senior students completed a validated nutrition knowledge survey regarding the Dietary Guidelines for Americans 2010. Further testing with a larger sample size is recommended.

Effects Of Grain Sorghum Muffin On Blood Glucose And Insulin Responses In Prediabetic Men, Xuan Gu

Graduate Theses and Dissertations

Prediabetes is a sub-health condition in the development to type 2 diabetes, which has been long overlooked. Grain sorghum contains functional starch fractions, which have been widely reported for their potential on blood glucose control and diabetes prevention. A human study with prediabetic men was conducted to investigate the effects of sorghum starch on postprandial blood glucose and insulin levels. Grain sorghum and wheat (control) muffins containing 50 g total starch were consumed by 15 prediabetic male subjects on two mornings with a 1-week washout period. Plasma samples were collected on -15 (baseline), 0, 15, 30, 45, 60, 75, 90, …

Control Of Agrilus Ruficollis (Coleoptera: Buprestidae) With Insecticides And Identifying Visual Attractants For Use In A Monitoring Trap, Soo-Hoon Kim

Graduate Theses and Dissertations

The rednecked cane borer, Agrilus ruficollis (F.), is a pest of cultivated and wild blackberries in the Midwestern and Eastern parts of the United States. Feeding, mating, egg laying and development of A. ruficollis from larvae to adult only occurs on primocane, the first year vegetative growth stage of blackberries, and not on the second year fruiting stage called floricanes that die after fruiting. Damage from this pest is caused by the larva girdling the primocane and tunneling in the pith, causing the formation of a gall. Gall formation on the primocane increases the chance of winter injury and can …

Are Concentration-Discharge Relations Influenced By Water Sample Collection Methods?, William M. Welch

Graduate Theses and Dissertations

Two primary methods of stream water sampling, the U.S. Geologic Survey (USGS) equal-width increment (EWI) and point samples (PS) from vertical centroid of flow (VCF) were compared at three river sites, the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. A little over three years of concentration data, which was paired with corresponding instantaneous discharge values (http://ar.water.usgs.gov/), was gathered separately at each site by the Arkansas Water Resource Center (AWRC) and the United States Geological Survey (USGS). The purpose of this study was to evaluate how concentration is related to discharge when water samples …

Study Of Parallel Programming Models On Computer Clusters With Accelerators, Chenggang Lai

Graduate Theses and Dissertations

In order to reach exascale computing capability, accelerators have become a crucial part in developing supercomputers. This work examines the potential of two latest acceleration technologies, Intel Many Integrated Core (MIC) Architecture and Graphics Processing Units (GPUs). This thesis applies three benchmarks under 3 different configurations, MPI+CPU, MPI+GPU, and MPI+MIC. The benchmarks include intensely communicating application, loosely communicating application, and embarrassingly parallel application. This thesis also carries out a detailed study on the scalability and performance of MIC processors under two programming models, i.e., offload model and native model, on the Beacon computer cluster.

According to different benchmarks, the results …

Biological Control Of Red Imported Fire Ant (Solenopsis Invicta) Using Pseudacteon (Diptera: Phoridae) In Central Arkansas, Sim Mckague Barrow

Graduate Theses and Dissertations

Red imported fire ants are major pests in the southeastern United States. As a part of an integrated pest management strategy, a biological control program has been implemented which includes Pseudacteon decapitating flies. These flies are parasitoids of fire ant workers and two species of Pseudacteon are established in Arkansas: Pseudacteon tricuspis and Pseudacteon curvatus. Pseudacteon cultellatus and P. obtusus were released in the spring and fall of 2013. Despite sampling throughout 2014, establishment cannot be confirmed. Two phorid fly sampling methods, hand aspirating and sticky traps, were studied. A vacuum aspirator was compared with two sticky trap configurations. Sticky …

Evaluation Of Porcine Ipec-J2 Cell Line Growth Rate And Immune Response To E. Coli (0111:B4) Lps, Xiaofan Wang

Graduate Theses and Dissertations

The objective of this study was to evaluate the intestinal porcine epithelial cell-jejunum 2 (IPEC-J2) cell line as a model to study the innate immune function of live pigs. Growth rates of IPEC-J2 cells in T-75 flasks and 96-well plates were evaluated using a hemocytometer and spectrophotometer for cell quantity measurements to determine growth rate and doubling time. Growth rates of IPEC-J2 cells in T-75 flasks and 96-well plates were 0.4016 and 0.2851 times of doubling/day respectively with a doubling time of 1.73 d and 2.43 d, respectively. Confluent IPEC-J2 monolayers were tested at five time intervals (0, 1, 2, …

Acanthamoeba Spp. As Reservoirs For Transmission Of Norovirus, Tun-Yun Hsueh

Graduate Theses and Dissertations

Human noroviruses (HuNoV) are the most common cause of foodborne disease outbreaks in the United States and the most common food commodities implicated in HuNoV outbreaks are leafy greens; however, the vehicle of transmission and point of contamination are often unknown. Here, we hypothesize that common free-living amoebae (FLA) ubiquitous in the environment may act as reservoirs of HuNoV and facilitate the transmission of these pathogens to fresh produce. The objective of this research was to first evaluate the interaction/association between HuNoV surrogates and Acanthamoeba by incubating them together and analyzing virus titer associated with amoeba through an 8 day …

A Wellness Profile Of Student-Veterans At 4-Year Higher Education Institutions: The Role Of Gender, Combat Tours, And Deployment, William Monroe Heath

Graduate Theses and Dissertations

Afghanistan and Iraq war student-veterans have increased in population on college campuses in the United States (U.S.) as a result of using the Post 9/11 GI Bill. Healthy Campus 2020 (American College Health Association, 2012) highlighted the importance of college student wellbeing, health promotion and disease prevention, while the U.S. Department of Veteran Affairs has called for an approach to services that is strength based (United States Department of Veteran Affairs, 2008). To date, however, wellness studies conducted on Iraq and Afghanistan student-veterans using an evidenced-based model of holistic wellness have not been conducted. This study was designed to address …

Assessing Net Returns To Blueberry Production Using A Decision Support Tool, Sokha Sok

Graduate Theses and Dissertations

The purpose of this study was to develop and assess the profitability of four highbush blueberry farming systems in the south: organic field production, conventional field production, organic high tunnel production and conventional high tunnel production. Four baseline budget scenarios, one for each system, are developed for a 15 year production period. The results suggest that under expected production and price conditions for Northwest Arkansas, while all four production systems generated positive present value of net returns, the conventional field production produced the highest present value of net returns across the 15 years. The breakeven years of production were 7 …

The Effects Of Book Format On Parent-Child Interaction During Joint Book Reading, Jennifer Lynn Bowman

Graduate Theses and Dissertations

Technology is a part of our society and is ever changing. Therefore, it is important to examine the effects that such innovations have on parent-child interactions, especially those that have been shown to promote children's early literacy learning and future school success. This study was conducted in the context of a larger project, The Family Reading Project, which investigated parent-child engagement in joint reading activities using mobile devices. This research compared parent and child behaviors when reading traditional books versus reading e-books to determine if book format had any effect on parent-child interaction. The results of this study were that …

The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke

Graduate Theses and Dissertations

In cotton production, nitrogen (N) is the most limiting nutrient and the demand is substantial. Foliar-N fertilization is regarded as an effective and environmentally sound method of supplying cotton with N during times of deficiency and high demand. In response to the potential benefits of the foliar-N fertilization of cotton, a myriad of foliar-N based fertilizers have been created; each with their own individual chemical technology and constitution. Experiments were performed with the objectives of examining the effects of the slow-release foliar-N fertilizer, Nitamin® (1) on the growth and development of field-grown cotton, (2) on uptake under various environmental conditions, …

European Consumers' Attitudes Towards Cisgenic Rice, Anne-Cécile Delwaide

Graduate Theses and Dissertations

The enhancement of existing plant breeding techniques, such as cisgenesis, allows plant breeders to enhance an existing cultivar quicker and with little to no genetic drag. Cisgenesis is the genetic modification of a recipient plant with natural gene(s) from a sexually compatible plant. Unlike transgenesis, which is the genetic modification of a recipient plant with gene(s) from any non‐plant organism, or from a donor plant that is sexually incompatible with the recipient plant, the results of cisgenesis could occur naturally over time. Currently, both cisgenic and transgenic products are classified as genetically modified organisms (GMOs) and are labeled as such …

Winter Field Pea As A Leguminous Cover Crop In Corn Production, Matthew Carroll Marsh

Graduate Theses and Dissertations

Leguminous cover crops, which fix nitrogen (N) from the atmosphere and add to the N content of the soil, have the potential to replace or partially replace commercial nitrogen fertilizers. In this experiment, field pea (Pisum arvense) was used as the leguminous cover crop in a conventional tilled corn (Zea mays) production system. In a 2-yr experiment (2008 and 2009), conducted at two locations in Arkansas, field pea was planted on half the field in the fall and allowed to grow until late April to early May. Field pea biomass was recorded, N content of biomass determined and then the …

Applications Of A New Geodata Crawler For Landscape Ecology: From Mapping Natural Stream Hydrology To Monitoring Endangered Beetles, Douglas Ryan Leasure

Graduate Theses and Dissertations

An investigation of endangered American burying beetle (Nicrophorus americanus) ecology led to development of a Geodata Crawler with applications in eco-hydrology. Geodata Crawler includes a national GIS (geospatial information systems) database with layers that quantify climate, land cover, soils, human development, and other attributes of the biosphere. For user-locations in the continental United States, Geodata Crawler can rapidly tabulate site-specific statistics within automatically delineated sample areas: points, site radii, watersheds, and riparian zones, among others. Geodata Crawler supported a multi-scale analysis of N. americanus habitat at a military installation in western Arkansas to produce a Landsat-based monitoring tool. Royle's N-mixture …

A Portable Impedance Biosensing System Based On A Laptop With Labview For Rapid Detection Of Avian Influenza Virus, Yixiang Wang

Graduate Theses and Dissertations

Avian Influenza Virus (AIV) H5N1 is a highly pathogenic virus found not only in birds but also in human. Rapid and sensitive detection method is needed to help prevent the spread of AIV H5N1. In this study, a portable impedance biosensing system based on a laptop with LabVIEW software was developed for detection of AIV H5N1. First, a virtual instrument was programmed with LabVIEW software to form a platform for impedance measurement, data processing and control. The audio card of a laptop was used as a function generator while a data acquisition card was used with the signal channels for …

Incarcerating Exceptional Pupils: Is There A School-To-Prison Pipeline In Eastern Oklahoma?, Brett Alan Fitzgerald

Graduate Theses and Dissertations

The school-to-prison pipeline metaphor represents an educational environment that allows public schools to push many at-risk children out of school and into the juvenile justice system or even worse, the adult criminal justice system (Wald and Losen, 2003; Lynn, 2010; Tuzzolo and Hewitt, 2006). The purpose of this study is to examine whether a school-to-prison pipeline exists in eastern Oklahoma, and if so, to better understand the characteristics of the public schools that may be contributing to it. The school-to-prison pipeline metaphor guided three research questions regarding whether certain public schools in eastern Oklahoma referred greater percentages of their students, …

Development Of A Turkey Coccidiosis Vaccine Candidate: An Attenuated Line Of The Protozoan Parasite, Eimeria Meleagrimitis, Thilakar Rathinam

Graduate Theses and Dissertations

Coccidiosis is an economically important enteric disease of poultry caused by protozoan parasites belonging to the genus Eimeria. Drugs are most commonly used to control coccidiosis. Widespread usage of anticoccidial drugs in the field has resulted in development of drug resistant strains and consequently decreased drug efficacy. An alternative control strategy using attenuated vaccines is desired. A series of experiments was designed to identify, isolate and attenuate a strain of a common and pathogenic species of Eimeria of turkeys, E. meleagrimitis.

Sensitivity of field isolates of turkey coccidia to the anticoccidials drugs amprolium, clopidol, diclazuril, and monensin was investigated. A …

Measuring The Role Of Inhibition In Auditory Discrimination In Mice, Tazima Nur

Graduate Theses and Dissertations

Understanding how inhibitory neurons affect sensory information processing in the cerebral cortex is an ongoing goal of both neuroscience and statistical physics research. In this master's thesis research project, an experimental system has been designed and built for studying how auditory dynamic range depends on inhibitory neurons, based on observations of mouse behavior. In this thesis, firstly, the topic of inhibition and information processing has been introduced. Then two papers related to inhibition and dynamic range has been reviewed in detail. One of the papers is an experimental work that analyzes the affect of inhibition on dynamic range. The other …

Trashed: The Myth Of The Southern Poor White, April Elizabeth Thompson

Graduate Theses and Dissertations

The fact of class has been a powerful tool in the process of identity formation, particularly in the American South, which has been viewed as a region apart from the national imaginary. To counter this exclusion, Southerners have often relied on stereotypes. One of the most prevalent and tragic of these is the stereotype of poor white trash, a construction that has been utilized to insist upon elite white Southerners' exceptionalism and innocence and to assert their rightful place in American historiography. While it is difficult to calculate their level of success, as perceptions of the region have varied through …

Alkaline Hydrolyzable-Nitrogen, Seeding Date, And Clay-Fixed Ammonium As Potential Indicators Of Rice Response To Nitrogen Fertilization In Arkansas, Anthony Michael Fulford

Graduate Theses and Dissertations

Several potential indicators of rice (Oryza sativa L.) response to nitrogen (N) fertilization include the soils alkaline hydrolyzableN (AHN) concentration, seeding date, and the soils clayfixed NH₄N content. Three studies were conducted to: (1) correlate AHN, determined using Illinois Soil Nitrogen Test (ISNT) or Nitrogen Soil Test for Rice (NSTaR), to plant parameters of interest and develop a fertilizer N rate calibration curve capable of predicting the 95% relative grain yield (RGY) fertilizer N rate for rice grown on clayey soils; (2) evaluate the influence of seeding date and N fertilization on rice plant growth and grain …

Increased Effluent Dosage Effects On Septic System Absorption-Field Products Of Differing Architecture Types, Andrew Richard Gibbons

Graduate Theses and Dissertations

Nationwide, approximately 20% of all homes use an on-site septic system as a form of household wastewater treatment. Since karst features are prevalent throughout the Ozark Highlands region of Northwest Arkansas, surface and groundwater resources are susceptible to contamination. Therefore, the objectives of this study were to evaluate the effects of soil condition (i.e., wet and dry) and absorption-field-product architecture type [i.e., chamber, gravel-less-pipe (GLP), polystyrene-aggregate (PSA), and pipe-and-aggregate (PA)] on in-product solution storage and biomat thickness in a profile-limited soil, and to identify the long-term acceptance rate (LTAR) of each product. During Phase I of this study (i.e., March …