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Application Of X-Ray Imaging As A Technique For Fissure Detection In Rough Rice Kernels, Zephania R. Odek

Graduate Theses and Dissertations

Fissured rice kernels break during milling, leading to head rice yield (HRY) reductions. Conventional fissure detection instruments cannot be used to observe fissures in rough rice kernels, the form in which rice in normally dried and stored. X-rays can penetrate hulls allowing visualization of the internal structure of a rough rice kernel. This study evaluated the capability of X-ray imaging to adequately detect fissures in rough rice and established a correlation between HRY and the fissured kernel percentage (FKP) in a rough rice sample. Fifteen long-grain rice cultivars, harvested in Arkansas in 2015 and 2016 were dried using heated air …

Models And Methodologies To Address Emerging Needs In Network And Supply Chain Optimization, Forough Enayaty Ahangar

Graduate Theses and Dissertations

In this dissertation, we model three different security scenarios and propose solution methodologies to address each problem.

Chapter 2 presents a large-scale optimization approach for solving a dynamic bi-level network interdiction problem (NIP) in which interdiction activities must be scheduled in order to minimize the cumulative maximum flow over a finite time horizon. A logic-based decomposition (LBD) approach is proposed that utilizes constraint programming to exploit the scheduling nature of this dynamic NIP. Chapter 3 considers a set of centers to which content (e.g., data or smuggled items), are assigned to ensure availability. An interdictor (e.g., border security officials) attempts …

Interactive Effects Of Flow Regime, Climate Change, And Angler Harvest On Smallmouth Bass At The Southern Range Extent, Christopher Middaugh

Graduate Theses and Dissertations

The Ozark-Ouachita Interior Highlands of Arkansas, Oklahoma, and Missouri are the southern extent of native Smallmouth Bass Micropterus dolomieu range. Smallmouth Bass are an important species economically and ecologically, but it is unknown how climate change may affect them in this region and in particular how Smallmouth Bass may be affected differently across streams from various flow regimes. Here I present three projects investigating how climate change, flow regime, and angler harvest may interact to affect Smallmouth Bass over the coming century. I first modeled present and future water temperatures and calculated growth rate potential for Smallmouth Bass from streams …

Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol

Graduate Theses and Dissertations

The discovery of methane in the martian atmosphere via numerous ground- and space-based sources has prompted the study of methanogens as models for life on Mars. Methanogens are microorganisms within the domain Archaea, many of which utilize carbon dioxide (CO2) and hydrogen to produce methane. The non-photosynthetic nature of methanogens indicates that they could exist in sub-surface environments, protected from harmful UV and ionizing radiation on the surface of Mars. These organisms also do not require organics, which are sparse on the planet.

Additionally, the wide variety of environments we find life in on Earth, as well as evidence for …

Characterization Of Nanoparticles Using Solid State Nanopores, Santoshi Nandivada

Graduate Theses and Dissertations

Solid state nanopores are widely used in detection of highly charged biomolecules like DNA and proteins. In this study, we use a solid state nanopore based device to characterize spherical nanoparticles to estimate their size and electrical charge using the principle of resistive pulse technique. The principle of resistive pulse technique is the method of counting and sizing particles suspended in a fluid medium, which are electrophoretically driven through a channel and produce current blockage signals due to giving rise to a change in its initial current. This change in current is denoted as a current blockage or as a …

Mushroom Inoculation On Switchgrass Feedstock During Storage: Effects Of Subsequent Pre-Processing For Intended Biofuels Production, Amandeep Singh Turay

Graduate Theses and Dissertations

The objective of this project was to examine the effect of fungal treatment and liquid hot water pretreatment of switchgrass combine in view of increasing glucose release. The fungal treatment consisted of incubating Pleurotus ostreatus in square switchgrass bales, at 50% moisture content for 25 days, 54 days, and 82 days. The digestibility of the switchgrass biomass was subsequently evaluated using Accelerase 1500 enzyme. Lignin is an important barrier to enzymatic hydrolysis, and it was stipulated that incubation with P. ostreatus would disrupt plant cell walls, resulting in enhanced saccharification. Three different concentrations of P. ostreatus were evaluated: 0%, 2%, …

Peptoid-Based Microsphere Coatings For Use As Tunable Biocompatible Interfaces, German Raul Perez Bakovic

Graduate Theses and Dissertations

The pursuit of sensitive, non-invasive, and cost efficient diagnostic tools for early stage disease detection have led to the development of sophisticated biosensor technologies for proteomic studies. As these markers increase in complexity, the role of support substrates grows increasingly important. Limitations in existing support substrates include the potential for increased sensitivity, binding specificity, and bio-stability. Ideal support substrates need to provide biocompatible and bioresistant surfaces, that offer high surface areas for binding, and enables the incorporation of diverse chemistries. The use of peptoids as the basis for the deposition of uniform microsphere coatings offers a mean to the attainment …

Comprehensive Assessments Of The Genetic Determinants In Salmonella Typhimurium For Fitness Under Host Stressors: Oxidative Stress And Iron Restriction, Sardar Abdullah

Graduate Theses and Dissertations

Salmonella is an intracellular pathogen that infects a wide range of hosts. The infected host utilizes reactive oxygen species (ROS) and iron-restriction to eliminate the pathogen. We used proteogenomics to determine the candidate genes and proteins that have a role in resistance of S. Typhimurium to H2O2. For Tn-seq, a highly saturated Tn5 library was grown in vitro under either 2.5 (H2O2L) or 3.5 mM H2O2 (H2O2H). We identified two sets of overlapping genes that are required for resistance of S. Typhimurium to H2O2L and H2O2H, and the results were validated via phenotypic evaluation of 50 selected mutants. The enriched …

Evaluating Methods For Quantifying Evapotranspiration In Arkansas Rice, Colby Reavis

Graduate Theses and Dissertations

The goal of this study was to evaluate different methods for quantifying evapotranspiration (ET) in commercial rice fields using different irrigation regimes. The rice fields were located in south central Arkansas. The different irrigation regimes were alternate wetting and drying (AWD) and continuous flooding (CF). Alternate wetting and drying and conventional flooding estimates of ET were 602 mm and 570 mm, respectively, based on field observations using eddy covariance. Models used to estimate ET estimated values between 498 and 653 mm for the 2015 growing season. The Penman Monteith actual evapotranspiration model (PM AET) performed best when compared to the …

Improvement In Simple Artificial Insemination In Sheep Using Chilled Extended Semen And Consideration Of Fertility In Ewes, Mohan Acharya

Graduate Theses and Dissertations

Three studies were conducted to improve simple artificial insemination in sheep using chilled extended semen and evaluate methods to predict fertility in ewes. The first study evaluated the effect of semen extenders and storage temperature on motility parameters of ram semen stored for up to 72 h. Single semen collected from each ram was divided into four parts and extended using four extenders: milk, TRIS, TEST, and CJ-2, diluted to 600 million sperm/ml and loaded into 0.25 ml straws for storage at 4 and 15° C. Most of the CASA motility parameters were higher after extension and storage at 4 …

Persistence Of Enteric Viruses On Surfaces Under Varying Environmental Conditions, Nicole L. Turnage

Graduate Theses and Dissertations

Human enteric viruses such as human norovirus (hNoV) and Aichivirus A (AiV) are common foodborne viruses with hNoVs being identified as the leading causative agent of foodborne illnesses in the U.S. Moreover, hNoVs have been identified as the leading cause of nonbacterial acute gastroenteritis in the U.S. and worldwide. Fomite surface contamination is a major transmission route for enteric viruses. The application of an optimized virus recovery method from fomites is essential for better understanding of virus persistence under varying environmental conditions (EC). This study aimed to optimize a surface sampling method for virus recovery from nonporous food contact surfaces …

Characterization Of A Tuberous Sclerosis Complex 2 Variant And Its Interaction Involving The Ras-Related Protein Rheb, Nosaiba Shokr

Graduate Theses and Dissertations

Structure-function relationships of any complex underlie the molecular details of the biological interactions. Rheb, Ras Homology Enriched in Brain, is a Ras-related protein, and it is genetically identified as a molecular switch. Rheb is regulated by cycling between the biologically active GTP and inactive GDP-bound forms. This regulation is partially controlled by an interaction with Tuberous Sclerosis Complex2 (TSC2), a GTPase activating protein (GAP). Upon interaction, TSC2 stimulates Rheb GTP hydrolysis and diminishes the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway is involved in proteins synthesis, cell cycle, and signaling. Mutation in TSC2 causes abnormal activation of Rheb …

Evaluating The Impact Of An All-Vegetable Protein Supplement Containing Fat Emulsifiers And Probiotics On Broiler Performance, Jordan Weil

Graduate Theses and Dissertations

Currently, several niche markets, such as organic and “all natural”, are marketed within the poultry industry. However, little research has been undertaken to determine the cost-effectiveness of poultry diets used to produce chicken within these markets. Specifically, the economics and resulting profits associated with raising chicken with antibiotic-free, all-vegetable (AV) diets are not evaluated. As national chain restaurants such as Chick-fil-A and Panera Bread begin to mandate poultry suppliers raise chicken without antibiotics and use AV diets, it becomes increasingly important to evaluate the economics for integrators. Given the rapidly changing feeding strategies necessary to respond to consumers’ and wholesalers’ …

Intravenous Administration Of Iron Oxide Nanoparticles In The Chicken Model, Huong Thi Ngoc Le

Graduate Theses and Dissertations

To be used in health care, the safety and effectiveness of nanoparticles needs to be tested in a living organism. The objective of this project was to develop the chicken as a convenient animal model to examine tissue targeting of intravenously (i.v.)-injected iron oxide (IO) nanoparticles. In Experiment 1, different doses of IO-COOH were i.v. injected into chickens; blood was collected at 0, 5, 15, 30, and 60 minutes post-injection; liver, spleen, lung, and kidney were collected after the last blood collection. For Experiment 2, IO-COOH and IO-PEG were i.v. injected into chickens; blood and the organs were collected at …

The Effects Of Sprayer Speed And Droplet Size On Herbicide Burndown Efficacy, Justin Carroll

Graduate Theses and Dissertations

An Apache AS1220 self-propelled boom sprayer with a 27.4 m (90 ft) boom was equipped with different sizes (02, 04 and 06) and types (TeeJet AI, XR, AIXR and TTI) of nozzles to achieve medium, very coarse and ultra coarse droplet sizes traveling 11 km/h (7 mph), 19 km/h (12 mph), and 29 km/h (18 mph). These combinations of speed and droplet size were evaluated for percent coverage of the spray and percent control of targeted weeds 3, 7, and 15 days after treatment (DAT). Four replications were conducted for each speed and droplet size combination except for at 19 …

The Structural And Functional Properties Of A Double Mutant Of Human Acidic Fibroblast Growth Factor (Hfgf-1), Arwa Mohammed Alghanmi

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1), a member of the FGF superfamily, is a potent mitogen and heparin-binding protein involved in a broad spectrum of biological processes, including angiogenesis, cell proliferation, and wound healing. Design of hFGF-1 with an increased thermal stability and an enhanced cell proliferation activity is highly desired for wound healing applications. Herein, we have designed the variant of FGF-1 by substituting two important amino residues in the heparin-binding pocket. The variant was overexpressed in Escherichia coli and was successfully purified to homogeneity using an affinity chromatographic procedure. Far-UV circular dichroism spectroscopic analysis showed that the …

Membranes For Food And Bioproduct Processing, Alexandru Marius Avram

Graduate Theses and Dissertations

Modified membranes for process intensification in biomass hydrolysis

Production of biofuels and chemicals from lignocellulosic biomass is one of the leading candidates for replacement of petroleum based fuels and chemicals. However, conversion of lignocellulosic biomass into fuels and chemicals is not cost effective compared to the production of fuels and chemicals from crude oil reserves. Some novel and economically feasible approaches involve the use of ionic liquids as solvents or co-solvents, since these show improved solvation capability of cellulose over simple aqueous systems. Membranes offer unique opportunities for process intensification which involves fractionation of the resulting biomass hydrolysate leading to …

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Graduate Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and …

B. R. Wells Arkansas Rice Research Studies 2016, R. J. Norman, K.A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Molecular And Biochemical Studies Of Several Novel Estrogen Receptor Alpha-Interacting Proteins In Breast Cancer Cells, Ahmed Edan Dhamad

Graduate Theses and Dissertations

Breast cancer is the second leading cause of cancer-related death in women, and approximately 70% of incidences are estrogen receptor (ER)-positive breast cancer. ERα and its interacting proteins play a key role in the development and progression of breast cancer. However, how ERα regulates its target gene expression and hence cell proliferation is not fully understood. To enhance our understanding of the molecular mechanism by which ERα regulates gene expression, we used a quantitative proteomic method to identify cellular proteins that interact with ERα. The first group of proteins that were identified to associate with ERα are heat shock proteins …

Evaluating The Policies That Lead To Stem Educational Attainment At The University Of Arkansas For Transfer Students, Bryan Hill

Graduate Theses and Dissertations

The US has a critical need to produce more STEM graduates and that need is exponentially more critical in Arkansas. Arkansas currently ranks last in the percent of STEM degrees conferred compared to overall degrees awarded. Students intending to pursue a STEM four-year college degree who start at a two-year college are significantly less likely to succeed in earning that degree. Arkansas passed Acts 672 and 182 aimed at strengthening the success of students who transfer from two-year colleges into four-year institutions. This study sought to evaluate the effectiveness of the Acts by determining if the University of Arkansas (UA) …

Evaluating One-Step Catalytic Free Method Including Hydrolysis, Esterification, Transesterification, And Degradation Reactions To Produce Biodiesel From Soybean Oil, Mahmood Gheni Jebur

Graduate Theses and Dissertations

Due to the environmental and economic impacts of diesel fuel based on petroleum, several studies have been done to find an alternative source of energy. Biodiesel is considered one of these alternative sources. It is a renewable source of energy produced from vegetable oils and animal fats. There are two main reaction routes used to produce biodiesel (fatty acid methyl esters). Transesterification reaction is the first route used to convert triglycerides to fatty acid methyl esters (FAMEs), while hydrolysis followed by esterification reactions are the second route employed to convert triglycerides to free fatty acids (FFA) and then further converted …

Peptide-Directed Nanoparticle Synthesis With A Denovo Pd-Binding Sequence Fused To A Reporter Protein, Rita Eloisa Tejada Vaprio

Graduate Theses and Dissertations

There is a need for low-cost nanoparticle materials in the context of new technologies for catalyst development. The purpose of this work was to recombinantly produce a 45- amino acid long metal binding peptide that is useful for nanoparticle synthesis. Using splicing by overlap extension PCR, a synthetic gene containing the fusion of the metal binding peptide with Green Fluorescent Protein (GFPUV) was constructed. The metal binding peptide, fused to reporter protein GFPUV, was expressed using high cell density fermentation. Palladium nanoparticles of an average diameter of 1.18 0.45 nm were synthesized by using the crude cell extract containing the …

Evaluating Thermal Comfort Of Broiler Chickens During Transportation Using Heat Index And Simulated Electronic Chickens, Kaushik Luthra

Graduate Theses and Dissertations

Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, quantification of heat loss of the broilers loaded on trailers is important in understanding the well-being of the broilers. We have developed four electronic chickens (E-chickens) to simulate the sensible heat loss of live …

Bee Communities On Managed Emergent Wetlands In The Lower Mississippi Alluvial Valley Of Arkansas, Phillip Lee Stephenson

Graduate Theses and Dissertations

Native bee communities that use emergent wetlands are among the least studied systems in bee research. Most native bee species are thought to be in decline based on the loss of usable habitat across the United States. I surveyed emergent wetlands in the lower Mississippi Alluvial Valley of Arkansas during the summers of 2015 and 2016 using pan traps, blue-vane traps, and sweep nets to determine the current status of bee communities in this system. I surveyed 11 sites in 2015 and 17 sites in 2016 and found that bee communities were similar in actively versus passively managed emergent wetlands. …

The Impact Of Social Situations On College Students’ Perceptions Of Sexual Consent, Casey Jane Ward

Graduate Theses and Dissertations

The majority of research examining sexual consent among college students focuses on how young adults communicate sexual consent during interactions immediately preceding a sexual encounter. However, preliminary research suggests that college students perceive that individuals begin to communicate sexual consent within social settings (e.g., at a bar) and through nonsexual interactions (e.g., text messaging); this has been labeled “outside the bedroom” consent. In order to further explore “outside the bedroom” consent, college students (n= 789) were randomly assigned to read four of sixteen vignettes. Within each vignette, four variables were manipulated: gender of the initiator (male or female), the social …

Structural Characterization Of Bacterial Collagenases, Ryan Bauer

Graduate Theses and Dissertations

Clostridium histolyticum secretes collagenases ColG and ColH to cause extensive tissue destruction during myonecrosis. The collagenases are multi-domain enzymes consisting of a N-terminal collagenase module, s1, polycystic kidney disease (PKD)-like domains (s2 in ColG; s2a and s2b in ColH) and collagen-binding domains (CBD) (s3a and s3b in ColG; s3 in ColH). The individual CBD and PKD-like domains chelate calcium to modulate stability and domain rearrangement. Though used by bacteria to break down collagen in the extracellular matrix during infection, therapeutic use of the enzyme to break down excess connective tissue has been approved by the FDA. Meanwhile, the use of …

Experiment-Based Quantitative Modeling For The Antibacterial Activity Of Silver Nanoparticles, Mohammad Aminul Haque

Graduate Theses and Dissertations

Silver (Ag) has been well known for its antimicrobial activity for a long time. Recent research showed the potential of Ag nanoparticles as emerging antimicrobial agents. However, little quantitative analysis has been performed so far to decipher the mechanism of interaction between nanoparticles and bacteria. Here, a detailed analysis based on kinetic growth assay and colony forming unit assay has been carried out to study the antimicrobial effect of Ag nanoparticles against Escherichia coli (E. coli) bacteria. It was observed that the presence of Ag nanoparticles increased the lag time of bacterial growth while not affecting the maximum growth rate …

Curricular Analysis Of The University Of Arkansas Composition I Pilot Course: Engl 1013, Community Ethnography, Morgan Lindsay Scholz

Graduate Theses and Dissertations

This thesis analyzes a new first-year writing course that is under consideration for implementation as the standard Composition I course at the University of Arkansas. The course utilizes an ethnographic approach to teaching critical writing skills to students. This thesis presents evaluation through a metacognitive lens and explores the course through a case study approach. This thesis also examines the expectations and concluding reflections of three stakeholder groups: students, instructors, and administrators.

Characterization Of The Thermal Environment During Transport Of Commercial Broiler Chickens, Douglas J. Aldridge

Graduate Theses and Dissertations

Transport of commercial broiler chickens from the farm to the processing plant is perceived to compromise welfare under some circumstances. Research has been conducted using European standard equipment to characterize the environment experienced by poultry during broiler transport. In contrast no studies have been reported on the environment experienced by broilers under United States standard industry practices during transport. Moreover, microenvironment temperatures within industry trailers have not been reported.

The present study characterized the thermal micro-environment experienced by broiler chickens during transport across different seasons. The temperatures were influenced by temperature mitigation practices (plastic wrap, double side board, single side …