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Identification Of Root-Knot Nematodes (Meloidogyne Spp.) Of Arkansas Using Molecular Diagnostics, Churamani Khanal

Graduate Theses and Dissertations

Root-knot nematodes (Meloidogyne spp.) are highly-adaptable, obligate plant parasites distributed worldwide. In addition, root-knot nematodes are an economically important genus of plant-parasitic nematodes. Meloidogyne incognita, M. arenaria, M. javanica, M. hapla and M. graminis have been reported from Arkansas during 1964 to 1994. Previous identifications were based primarily on morphological characters and host differentials. In this study, identification using molecular diagnostics methods was performed to identify Meloidogyne species present in Arkansas. A total of 106 soil and root samples from 36 of the 75 counties were collected and processed to obtain root-knot nematodes. Polymerase chain reaction (PCR) was performed …

Microbial Community Shifts Caused By Changes In The Primary Oxidant At A Drinking Water Treatment Plant, Connie Marie Moloney

Graduate Theses and Dissertations

Microbial communities resistant to common oxidants can cause concerns for water treatment plants (WTPs). If a bacterium is not fully oxidized during disinfection, these species can impede upon filtration processes or seed biofilms in the distribution system. In an effort to minimize disinfection by-products (DBP's) that result from the reaction of chlorine (Cl2) with natural organic matter, water treatment plants have the option to change their primary oxidant to chlorine dioxide (ClO2). The following study examines the change in microbial communities during the sedimentation process under differing oxidation regimes, specifically chlorine (Cl2) and ClO2 at the local water treatment plant …

Evaluation Of Medicago Truncatula Accessions For Triterpene Saponins And Their Potential Impacts On Plant Pests, Samantha Roberson

Graduate Theses and Dissertations

Plants have developed numerous ways to protect themselves from microbes and insects, including producing secondary metabolites that negatively impact an invading pathogen or pest. Saponins are specialized metabolites found in many plant species and may play a role in protecting the plant. Though saponins are found in many plant species, triterpene saponins are found primarily in dicotyledons, including legumes. Medicago truncatula is a model system for studying legume biology and some accessions accumulate high concentrations of saponins. Accessions of M. truncatula known to have differing levels of saponins in both foliar and root tissues were tested for their suitability as …

The Phenotypic Effects And Transcript Response Of Salt Stress, The Impact Of Viral Infection On Salt Stress Symptoms, And The Effect Of Salt Stress On Soybean Virus Vector Activity In Soybean Varieties That Vary In Chloride Uptake, Alma Glenn Laney

Graduate Theses and Dissertations

With the increase in saline soils worldwide, understanding the mechanisms for salt tolerance in plants is important to reduce yield loss due to salt stress. Soybean, Glycine max (L.) Merr., genotypes differ in chloride uptake with genotypes that take up chloride into foliar tissues tending to be salt-sensitive whereas those that partially exclude chloride from the leaves are more salt-tolerant. Transcriptional and physiological responses were measured in two soybean cultivars, Clark and Manokin, which differ in chloride uptake in response to salt stress and in combination with Soybean mosaic virus (SMV) and its aphid vector, Aphis glycines . The interaction …

Characterization Of A Novel Fungal-Specific Gene, Fug1, In Fusarium Verticillioides, John Byron Ridenour

Graduate Theses and Dissertations

Filamentous fungi are responsible for numerous plant and animal diseases. The filamentous ascomycete Fusarium verticillioides is a globally important pathogen of maize, capable of causing severe yield reductions and economic losses. Also of substantial concern is the contamination of infected kernels with fumonisins, toxic secondary metabolites linked to toxicoses in humans and livestock. The number of sequenced fungal genomes is rapidly increasing. However, functional characterization of fungal genes has not progressed at a comparable rate. In pathogenic fungi, uncharacterized genes represent a source for novel virulence factors or anti-fungal targets. Therefore, to fully understand the genetic mechanisms underlying fungal pathogenesis, …

Consumer Acceptance And Willingness To Pay For Genetically Modified Rice In China: A Double Bounded Dichotomous Choic Contingent Valuation Survey Calibrated By Cheap Talk, Jing Jin

Graduate Theses and Dissertations

Considering population growth, limitations on land and water resources, and contamination to the ecosystem due to agricultural activities, current rice production in China is facing pressure to fulfill national demand. Self-sufficiency of rice has been a long-held political objective of the Chinese government and it is national goal to maintain the equilibrium between the national production and consumption or even achieve a supply surplus in rice. With the developing bio-technology of genetic modification (GM), scientists believe that using genetically modified cultivars may ease the pressure mentioned above. However, both the government and the people are very cautious about large-scale cultivation …

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 …

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 …

Price Discovery And Futures Spreads For U.S. And Chinese Rice Futures Market, Wei Yang

Graduate Theses and Dissertations

Rice, the primary staple food for more than half the world's population, is the second world's most consumed food grain. In recent years, world rice price has increased and become more volatile especially in the period 2007-2010. Rice price volatility has a huge impact on Asian countries, especially countries in Southeast Asia where rice is a staple food for millions of households. Private market tools to manage price risk and discover price such as futures markets have been analyzed and assessed as possible solutions to coping with rice price volatility issue. Two primary functions of agricultural commodities futures markets are …

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, …

Use Of Remote Imagery And Object-Based Image Methods To Count Plants In An Open-Field Container Nursery, Josue Nahun Leiva

Graduate Theses and Dissertations

In general, the nursery industry lacks an automated inventory control system. Object-based image analysis (OBIA) software and aerial images could be used to count plants in nurseries. The objectives of this research were: 1) to evaluate the effect of an unmanned aerial vehicle (UAV) flight altitude and plant canopy separation of container-grown plants on count accuracy using aerial images and 2) to evaluate the effect of plant canopy shape, presence of flowers, and plant status (living and dead) on counting accuracy of container-grown plants using remote sensing images. Images were analyzed using Feature Analyst® (FA) and an algorithm trained using …

The Economic Viability Of Cocoa Crop Insurance In Ghana, Justin D. Mckinley

Graduate Theses and Dissertations

This study was motivated by the fact that Ghanaian cocoa producers face lower yields than other main cocoa producing counties which in turn increases food insecurity for smallholder producers. In addition, low yields experienced by Ghanaian producers is a driving factor for forest degradation and deforestation as cocoa producers encroach further into previously undisturbed forests in efforts to increase their incomes. There are currently production methods to achieve higher yields readily available in Ghana; however, many producers choose not to adopt these methods because they are seen as too risky, or simply cannot adopt them due to financial/credit constraints. A …

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 …

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, …

The Elimination Of Listeria Monocytogenes Biofilms From Stainless Steel Deli Meat Slicer Components By The Use Of Hurdle Technologies, Alexandria Wynne Mertz

Graduate Theses and Dissertations

Listeria monocytogenes growth is of the greatest concern amongst ready-to-eat foods. The United States Department of Agriculture's Food Safety and Inspection Services determined that deli luncheon meats pose the greatest risk of contamination from L. monocytogenes Industrial meat slicers have many removable parts that are connected with sealers and gaskets, which can become worn over time. These spaces cannot be cleaned adequately, therefore are susceptible to bacterial growth. Planktonic cells form biofilms in order to protect the cell from adverse conditions, like during routine cleaning and sanitation. Once a biofilm is formed, the bacteria are much more difficult to eradicate …

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 …

Functional Characterization Of The Arginine Vasotocin 4 Receptor (Vt4r) In Sensory Circumventricular Organs Of The Chicken Gallus Gallus, Nguiessan Alphonse Aman

Graduate Theses and Dissertations

Past studies have shown that the avian vasotocin 4 receptor (VT4R), homologous to the mammalian arginine vasopressin receptor 1a (V1aR/AVPR1A) is involved in immobilization stress. It was not known, however, whether the receptor is also associated with osmotic stress, and if so, what brain regions may be involved. Four treatment groups of chicks were used for the study. One group was subjected to 1h immobilization stress and two groups were administered intraperitoneal injection of 3 M NaCl or 0.15 M NaCl. One additional group served as controls. After 1 h, blood samples were taken for the determination of plasma levels …

The Mechanism Of Lhcp Insertion Into Thylakoid Membranes, Larae Brown

Graduate Theses and Dissertations

The light harvesting chlorophyll a/b-binding proteins (LHCPs) are the most abundant membrane proteins. LHCP is a nuclear encoded protein which is targeted to the thylakoid membranes by chloroplast signal recognition particles (cpSRP). Insertion into thylakoid membranes is facilitated by the cpSRP receptor cpFtsY and the Alb3 translocase. Work here focused on understanding the molecular events of LHCP insertion into the thylakoid membranes. Specifically, we sought to develop a tool to detect the insertion of the lumen-localized loop of LHCP into thylakoid membranes, which relies on cleavage of the loop by a thylakoid lumen processing protease. We also sought to understand …

Investigation Of Nuclear And Cytoplasmic Functions Of The Dlipin Protein Of Drosophila Melanogaster, Qiuyu Chen

Graduate Theses and Dissertations

Lipin family proteins are highly conserved proteins present in species ranging from mammals to yeast. Lipin 1, the first Lipin gene identified in fatty liver dystrophy (fld) mutant mice, encodes the bifunctional protein Lipin 1, which can serve as an Mg2+-dependent phosphatidic acid phosphatase (PAP) and transcriptional co-regulator. dLipin, the single Lipin ortholog of Drosophila melanogaster, is required in triglyceride synthesis and fat body development. To study the transcriptional co-regulator activity of dLipin, nuclear receptors were screened to find receptors that interact with dLipin. The genetic interaction data indicated that Drosophila hepatic nuclear receptor 4 (HNF4) was a promising candidate …

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 …

Changes In Monomeric And Polymeric Pigments During Chokeberry Juice Processing, Kail David Wilkes

Graduate Theses and Dissertations

Chokeberry consumption has been increasing due to research exposing great potential of health-promoting compounds. However, chokeberries are highly astringent and are typically consumed in processed forms in which product heating is applied. Processing chokeberries has been reported to degrade bioactive compounds, thus limiting the potential for consumers to obtain their health-promoting benefits. The purpose of this research was to examine the effects of chokeberry juice processing and storage on anthocyanin, flavonol, proanthocyanidin, hydroxycinamic acid, and polymeric pigment content, as well as percent polymeric color. In addition, new analytical methodologies were explored to better understand possible outcomes of polymeric pigments due …

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 …

Identification And The Significance Of Selective Proteins In Bile And Plasma Of Normal And Health-Compromised Chickens, Balamurugan Packialakshmi

Graduate Theses and Dissertations

During the last 50 years, animal breeding programs in commercial poultry have made significant progress in the bodyweight gain of broilers but led to several metabolic and skeletal disorders. Lameness associated with proximal femur known as femoral head separation (FHS) or femoral head necrosis (FHN) is one of the major metabolic disorders in poultry industry. In order to select for healthy chickens, markers that can distinguish between healthy and affected birds are required. Biomarkers from blood represent an ideal and rich source of markers which can be obtained using minimally invasive methods. The biomarkers were explored in an experimental model …

Dissection Of Gray Leaf Spot Of Maize Through Functional Genomics, Robert Louis Hirsch

Graduate Theses and Dissertations

Gray leaf spot, caused by Cercospora zeae-maydis, is a devastating disease of maize that reduces yields and increases management costs. C. zeae-maydis penetrates maize leaves through stomata, but the biological and molecular bases of this process are poorly understood. The goal of this research was to elucidate the biological parameters of stomatal infection in C. zeae-maydis, and to identify and characterize novel genetic pathways involved in stomatal sensing and pathogenesis. Histopathological observations of a GFP-expressing strain of C. zeae-maydis during infection of maize indicated that the fungus responded to host-derived stomatal cues during the infection process. C. zeae-maydis was observed …

Population Genetics, Distributions And Phenology Of Bombus Latreille, 1802 And Xylocopa Latreille, 1802 (Hymenoptera: Apidae), Amber Dawn Tripodi

Graduate Theses and Dissertations

This work addresses multiple knowledge gaps in bee ecology, population health and phylogeography in order to provide insights into the changing distributions of native bees. A comparison of Arkansas bumble bee records mirrors range-wide surveys, with records of stable species (Bombus bimaculatus Cresson, 1863 and B. impatiens Cresson, 1863) increasing three-fold, and records of the declining B. pensylvanicus (DeGeer, 1773) dropping to 60% of historical levels. However, nationally-recommended conservation-genetics tools did not mirror these results on a regional level. Stable and declining species had equivalent genetic diversity in samples from Arkansas and Tennessee (H_S range: 0.46-0.63). Diploid males, …

Central Administration Of Neuropeptide Y (Npy) And Vasotocin 4 Receptor (Vt4r/V1ar) Antagonists On Food Intake And A Stress Response In Chicks, Megan Ann Hancock

Graduate Theses and Dissertations

The objective of this study was to determine the central effect of the VT4R antagonists (SR-49059 and H-5350 (Manning compound)) on corticosterone (CORT) levels during stress and food intake. A 22-gauge stainless steel guide cannula was surgically implanted into the lateral ventricle of the birds. A preliminary study was done to test the antagonists and their role on food intake. Birds were injected with saline, NPY (4µg), NPY (4µg)+SR-49059 (250ng), or NPY (4µg)+Manning compound (250ng). Birds injected with saline had the lowest 1h food intake (17.7g1.6). Birds injected with NPY+saline had a significantly higher intake (27.1g 1.0), which was enhanced …

Short-Term Effects Of Poultry Litter Or Woodchip Biochar Amendment In A Temperate Zone Agronomic System, Katy Elizabeth Brantley

Graduate Theses and Dissertations

Biochar, a charcoal product produced by the anaerobic thermal decomposition of biomass, can provide agronomic benefits when soil applied. However, research is lacking in temperate region soils investigating specific biochar products and their effects on agronomically important crops. A greenhouse study utilizing poultry litter biochar and a field study utilizing pine woodchip biochar were conducted to observe the effects of biochar application to Northwest Arkansas soils on corn growth and nutrient availability. A third experiment investigated poultry litter and pine woodchip biochar influences on soil water retention. In all three experiments, biochar was applied at three rates (0, 5, and …

Oxidative Stability Of Conjugated Linoleic Acid Rich Soy Oil Obtained By Heterogeneous Ruthenium Catalysis, Saurabh Ravindra Lele

Graduate Theses and Dissertations

Conjugated linoleic acid (CLA) has multiple health benefits but it is difficult to obtain sufficient CLA in a healthy diet to obtain the clinical effects. A CLA rich-soy oil (CLARSO) with up to 20% CLA has been produced by heterogenous catalysis but no studies of its oxidative stability have been reported. CLARSO and soy oil primary and secondary oxidation products were measured at 50oC in the dark. The CLARSO was less stable than soy oil but adsorption bleaching improved its oxidative stability. However, induction times were dependent on the analytical method used. Fatty acid oxidation kinetics was determined by measuring …

Influences Of Contexts On Consumers' Visual Attention Towards Food Images: Eye-Tracking Studies, Baoyue Zhang

Graduate Theses and Dissertations

Food perception is influenced not only by sensory properties of the food itself, but also by individuals- or environment-related contexts. Visual cue appears to be the most dominant factor in modulating food perception. This research aimed to determine whether individuals' visual attention towards food images can vary as a function of contextual variables such as hunger/fullness (Chapter 3), chronic stress (Chapter 4), and culture (Chapter 5). In Chapter 3 and Chapter 4, participants were asked to freely view visual slides, including four different images per slide, shown on the monitor. Using eye-tracking techniques, participants' visual attention towards food images (e.g., …

Integration Of Herbicide Programs With Cultural And Mechanical Practices For Managing Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Soybean (Glycine Max), Holden Bell

Graduate Theses and Dissertations

Herbicide-resistant Palmer amaranth is the most troublesome weed in Arkansas row crops, causing producers to rely heavily on multiple mechanisms of action to reduce selection pressure for further evolution of herbicide resistance and to successfully produce a profitable crop. It is critical for the sustainability of weed management not only to adequately control this weed but also to reduce the soil seedbank using both non-chemical and chemical practices. Studies were conducted to determine the effect of soybean row spacing, seeding rate, and herbicide program on Palmer amaranth emergence, survival, and seed production in soybean, the effect of drill-seeded soybean population …