Life Sciences Commons^™

Gene Expression And Physiological Analyses To Study Metabolic Shifts In Medicago Truncatula Subjected To Biotic Stresses, Michelle Ryan Martin

Graduate Theses and Dissertations

Plants are frequently under attack from pests and deploy various defense mechanisms to fight off predators. Many plant defenses are induced following herbivory or pathogen infection. An investment in defense could potentially lead to a diversion of metabolic resources away from primary metabolism, including reduction in plant commitment to photosynthesis. In this thesis, changes in expression levels of representative genes for primary and secondary metabolism were studied using real-time polymerase chain reaction (PCR) in Medicago truncatula Gaertner subjected to beet armyworm (Spodoptera exigua H¨¹bner) damage or Phoma medicaginis Malbr. & Roum. infection. Photosynthetic yield was also measured using chlorophyll fluorescence …

Hospitality Students Perceptions About High Risk Behaviors In Relation To Destructive Behaviors And Decision Making, Boris A. Roslov

Graduate Theses and Dissertations

This study investigated hospitality students' perceptions regarding alcohol consumption and personal actions related to high risk behaviors. Those behaviors included: sexual encounters and binge drinking, and their effect on academic tasks and performance. The study investigated whether the hospitality student who is employed full time consumes alcohol at a higher level than a hospitality student does that is not employed full time.

Assessing Biodegradable Containers For Growing Long-Term Greenhouse Crops In Subirrigation System, Stephanie A. Beeks

Graduate Theses and Dissertations

The objective for this research was to assess the efficacy of biodegradable containers compared to plastic containers for the production of long-term crops using a subirrigation system. Plastic and various biocontainers were used to grow `Rainier Purple' cyclamen (Cyclamen persicum L.) in ebb-and-flood benches. After 15 weeks, the physical properties of the containers were tested. The used plastic containers had strengths of 23.3, 23.5 and 21.9 g for the bottom, middle and top zones respectively. The peat, dairy manure and wood fiber containers had strengths of less than 2 kg for each zone. The peat, dairy manure, wood fiber and …

Analyzing Spring Freeze Impacts On Deciduous Forest Productivity Using Modis Satellite Imagery, Karl Lintvedt

Graduate Theses and Dissertations

The impacts of an April 2007 spring freeze event on the productivity of deciduous broadleaf forest were analyzed using geographic information system (GIS) tools. Forest productivity was modeled using the Enhanced Vegetation Index (EVI), as recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor. Measures of spatial autocorrelation were used to quantify the degree of spatial congruence between a map depicting the severity of the freeze event, and maps modeling forest productivity throughout the year. The results show a geographic correlation between the unseasonably low minimum temperatures sustained during the freeze and the unusually low forest productivity that followed. …

Detection Of Two Pathogens Of High Importance To The National Poultry Improvement Plan: Salmonella Spp. And Mycoplasma Spp., Robin Levi Jarquin

Graduate Theses and Dissertations

In 1935, the National Poultry Improvement Plan (NPIP) was created to control Salmonella gallinarum and Salmonella pullorum . These two pathogens were devastating economically for poultry producers. Through cooperative efforts using vaccination and strict biosecurity, these two pathogens were eradicated from the United States. Currently, the NPIP program is targeting two other poultry pathogens, Salmonella enterica serovar Enteritidis and Mycoplasma . In the broiler industry it targets 2 specific Mycoplasma species (synoviae, gallisepticum). Vaccinations for these bacteria are available, but are not fully effective at controlling all strains and serovars. Thus, constant monitoring systems and strict biosecurity measures are necessary …

Systematics Of Protosteloid Amoebae, Lora Lindley Shadwick

Graduate Theses and Dissertations

Because of their simple fruiting bodies consisting of one to a few spores atop a finely tapering stalk, protosteloid amoebae, previously called protostelids, were thought of as primitive members of the Eumycetozoa sensu Olive 1975. The studies presented here have precipitated a change in the way protosteloid amoebae are perceived in two ways: (1) by expanding their known habitat range and (2) by forcing us to think of them as amoebae that occasionally form fruiting bodies rather than as primitive fungus-like organisms. Prior to this work protosteloid amoebae were thought of as terrestrial organisms. Collection of substrates from aquatic habitats …

Effect Of Soyasaponin Fractions On Human Colon Cancer Cells, Joseph Tyler Salyer

Graduate Theses and Dissertations

Group B saponins, the predominant form of saponins in heat-treated soy products, have been shown to possess hypocholesterolemic, antimutagenic, and anticarcinogenic properties. Previous studies have evaluated crude mixtures of soyasaponins, but studies evaluating a single purified soyasaponin as an anticarcinogenic agent are limited. The goal of this study is to examine the effects of purified soyasaponins I and III as well as their aglycone form, soyasapogenol B, as anticarcinogenic agents on the human colon adenocarcinoma cell line Caco-2. Experiments were conducted to determine the effects of purified soyasaponins on cell proliferation, Protein Kinase C (PKC) activity, and cell morphology in …

Proteome Based Development Of Novel Affinity Tail For Immobilized Metal Affinity Chromatography And Hydrophobic Interaction Chromatography, Neha Tiwari

Graduate Theses and Dissertations

At industrial scale, reducing the step in purification and recovery is desired; this not only decreases the cost but also increases the yield. Hydrophobic Interaction Chromatography (HIC) and Immobilized Metal Affinity Chromatography (IMAC) both are not harsh on biological structure or activity of proteins; also both the techniques are economical and therefore a suitable choice at industrial level. This dissertation comprises of three parts. Purpose for the Part I was to identify and characterize Escherichia coli proteins which display affinity towards both IMAC and Hydrophobic Interaction Chromatography (HIC). Co (II) IMAC was chosen as the primary capture step, followed by …

Host-Virus Interactions Of Infectious Laryngotracheitis Virus Infection In Cultured Cells, Jeong Yoon Lee

Graduate Theses and Dissertations

Infectious laryngotracheitis virus (ILTV; Gallid herpesvirus 1) causes upper respiratory diseases in mainly chickens and exhibits 90-100% of high morbidity and up to 70% of mortality, resulting in huge economic losses in the poultry industry worldwide.

To study host-ILTV interactions, the changes in genome-wide gene expressions in response to wild-type and vaccine ILTV infections in primary chicken embryo lung cells were investigated using microarray analysis. Results provide crucial insights into host cell pathogenic and immunogenic responses against wild-type and vaccine ILTV infections. Using microarray method and Ingenuity Pathway Analysis (IPA) bioinformatics tool, 273 and 306 differentially expressed genes were identified …

Can Antioxidant-Rich Berries Improve Risk Factors Associated With Cardiovascular Disease In Postmenopausal Smokers?, Jordan Alaine Teeple

Graduate Theses and Dissertations

The purpose of this study was to examine the effects of smoking on risk factors associated with cardiovascular disease (CVD) and determine the efficacy of antioxidant-rich berries in ameliorating these risk factors in postmenopausal smokers. Menopause and cigarette smoking have been identified as major risk factors for CVD due to a decrease in antioxidant protection, increase in inflammation and oxidative stress, and adverse changes in serum lipids. Antioxidants, specifically flavonoid compounds found in blackberries and blueberries, have been shown to prevent low-density lipoprotein cholesterol oxidation and thus prevent downstream inflammation and oxidative stress. Healthy, postmenopausal nonsmokers (n=14) and smokers (n=31) …

Improvements On Just-About-Right (Jar) Scales As Product Optimization Tools Using Kano Modeling Concepts, Bangde Li

Graduate Theses and Dissertations

Attribute Kano characteristics are useful in product design to prioritize development efforts. However, attribute Kano characteristics have not been discussed and applied to product optimization when using Just-About-Right (JAR) scales. Product optimizations without identifying attributes Kano characteristics can be misleading. The two objectives in this research were: 1. Determine attribute Kano categories using a modified classic Kano classification methodology. 2. Propose a method to measure attribute performance and identify attribute Kano characteristics to direct product optimization. Two methodologies of attribute Kano classification were investigated. In experiment one, a modified classic Kano methodology was employed to determine attribute Kano categories through …

Effect Of Nutrient Supplements On Cucumber Fermentation By Lactic Acid Bacteria, Shruti Tripuraneni

Graduate Theses and Dissertations

Lactic acid bacteria (LAB) are important industrial microorganisms involved in fermentation of food and beverage products. The strict fermentative growth of LAB has complex requirements of various nutrients including amino acids, vitamins and minerals. Information about the effect of these nutrients on the growth of LAB in cucumber fermentation is not readily available. It is evident, from previous research that certain nutrients like; leucine, isoleucine, tryptophan, valine, biotin, nicotinic acid, pantothenic acid, riboflavin, manganese and magnesium are beneficial for LAB growth, but are not provided in sufficient quantities by the cucumber in the brine. The objective of this study was …

Visualizing The Spatial Localization Of Active Matrix Metalloproteinases (Mmps) Using Maldi Imaging Ms, Sasirekha Muruganantham

Graduate Theses and Dissertations

Biomaterial implantation induces the foreign body response (FBR). Development of longer-term implants relies on the thorough understanding of the FBR. The progression of the FBR is regulated by a number of biomolecules including cytokines, chemokines, and matrix metalloproteinases (MMPs). The nature of the FBR requires the spatial and temporal regulation of these mediators. MMPs are an extremely large and diverse group of enzymes that play key roles in regulating the FBR. Precise spatiotemporal regulation of MMPs defines their proteolytic activities. The aim of this project is to develop a new bioanalytical method to visualize the localization of active MMPs at …

Design And Fabrication Of Nanofluidic Systems For Biomolecule Characterizations, Orain Ansel Hibbert

Graduate Theses and Dissertations

Nanofluidic channel systems were designed and fabricated by combining MEMS microfabrication with AFM nanolithography. In the fabrication process flow, photolithography was first utilized to pattern microfluidic channels and reservoirs on a 4" Pyrex substrate. Subsequently, atomic force microscopy (AFM) based nanolithography was used to mechanically fabricate nanochannels to connect the microreservoirs which formed the inlet and outlet of the nanofluidic system. A Tap190 Diamond-Like Carbon (DLC) AFM tip with a force constant of 48 N/m and a radius of less than 15 nm was used as the nanolithography tool. The resultant nanochannel ranges from 20 to 80 µm in length …

Crisis Communication Needs Assessment: A Delphi Study To Enhance Instruction For Agricultural Communicators And Other Stakeholders, Allyson Ceary Mcguire

Graduate Theses and Dissertations

Agricultural communicators and industry stakeholders need to be able to develop, prepare and implement crisis communication plans to help assure the sustainability of the agriculture industry should a crisis event occur. A thorough exploration of possible options and needs for training crisis communicators is a needed study in the agriculture industry. Students learning to prepare for managing crises in real life situations are rarely taught in a hands-on, experiential manner. Students can read and analyze case studies pertaining to crises, but without having an actual crisis; little means exist for preparing students for real world situations. There is a need …

Protein Utilization And Requirements In Broiler Breeders, Ricardo David Ekmay

Graduate Theses and Dissertations

Advances in the genetics of poultry have created unintended consequences to the broiler breeder industry. Excessive weight has been shown to have many negative effects, including double hierarchies, multiple ovulations, and fatty liver. In an effort to curb excessive body weight gain, both the protein requirements and feeding strategies of broiler breeders are being revisited. A series of studies were conducted to determine the protein and amino acid requirements of broiler breeders during the production phase and to determine the interrelationship between protein turnover and egg formation. In the first trial, a 2x3x3 factorial study was conducted to determine the …

Subcritical Water Hydrolysis Of Whey Proteins, Ashley Dawn Espinoza

Graduate Theses and Dissertations

Hydrolyzing food by-products is a unique approach to potentially increase by-product value and reduce waste. An abundant by-product of cheese production, whey, contains all essential amino acids and some distinctive peptides with functional and nutraceutical properties. Typically, proteins from whey are tailored for specific uses by chemical or enzymatic hydrolysis; however, subcritical water hydrolysis is a novel alternative used successfully to hydrolyze various substrates. Nevertheless, minimal research exists on: (1) the hydrolysis of whey protein; (2) the incorporation of additives; (3) the hydrolysis of whole whey; and (4) the production of volatiles when using subcritical water hydrolysis.

Therefore, whey protein …

The Incidence Of Plexiform Lesion Formation In Lines Divergently Selected For Ascites, James Grant Mason

Graduate Theses and Dissertations

Complex Vascular Lesions, (CVL) are a common vascular change associated with idiopathicpulmonary arterial hypertension (IPAH). CVL have been characterized in studies using animal models involving, but not limited to, Sprague-Dawley rats and poultry (Abe et al., 2010; Wideman et al., 2011).IPAH has been documented in poultry although no connection has been made with CVLs. The current study characterizes CVL in the lungs from broilers derived from lines divergently selected for 15 generations for ascites susceptibility under conditions of simulated high altitude. The ascites RES and SUS lines were sampled for CVL incidence over time. Both lines were reared in a …

In Vitro Selection Of Aptamers Against Avian Influenza Virus H5n1, Jingjing Zhao

Graduate Theses and Dissertations

Over $10 billion losses in the poultry industry were caused by avian influenza (AI) so far. Rapid and specific detection of avian influenza virus is urgently needed with the concerns over the outbreaks of highly pathogenic H5N1 influenza virus and cases of animal and human infection. Aptamers are oligonucleic acid or peptide molecules that bind a specific target molecule with good affinity. They show better thermal stability than antibodies. The goal of this research was to select DNA-aptamers as the specific recognition element of AI H5N1virus to be used in detection assays specific for field application. In this study, Systematic …

Factors Determining Media Coverage Of Meat And Poultry Recalls: Evidence From The Ap Newswire, Thais Fregonesi Carvalho

Graduate Theses and Dissertations

Food safety is an important public health issue. Product recalls are an important part of the overall food safety system and occur when potentially unsafe products enter the marketplace. However, it is important that information about the recall ultimately reaches the public. This research assesses the publicity that recalls receive by the popular media. The focus is specifically on recalls of meat and poultry products. Publicity is measured by coverage in the AP Newswire. Data were gathered from the United States Department of Agriculture's Food Safety and Inspection Service (FSIS) and cover meat and poultry recalls from 1982 to 2009. …

Foliar Symptoms Of Acute Ozone Injury And Exposure Response Characteristics Of Select Native Perennials, Susan Denise Frey

Graduate Theses and Dissertations

Twenty seven perennial species native to the Eastern Temperate Forests Level I Ecoregion were exposed to an acute ozone (O3) treatment consisting of a target peak O3 concentration of 2.0 ppm for 30 minutes in a closed chamber environment, during the summer of 2010. Plants were evaluated for visible foliar injury symptoms and symptoms were described and photographically documented. Ten of the 27 species developed visible foliar injury in which interspecific and intraspecific response to O3 was observed. A severity index was used to compare response to acute ozone exposure for the ten species displaying visible foliar injury. Species showing …

Enhancing Soybean Profitability Using Portfolio Theory, Osemenkhian Cynthia Onyechere

Graduate Theses and Dissertations

The purpose of this study was to estimate the effect of utilizing portfolio theory on producers' profitability in the production of soybeans in three test locations - Keiser, Marianna and Rohwer - in Arkansas. The study used empirical yield data, their variances and covariances over a nine year period (2002-2010) in selecting a portfolio of soybean varieties that maintains or increases yield while minimizing the yield risk. Furthermore, carbon emissions associated with soybean production was estimated by modeling the effect of a potential carbon tax as well as the potential benefit of carbon offset payments resulting from carbon sequestration. The …

Rice (Oryza Sativa) Response To Low Glyphosate Rates As Influenced By Cultivar, Growth Stage, And Imazethapyr Applications, Jason R. Meier

Graduate Theses and Dissertations

Off-target movement of glyphosate onto rice is a perennial concern when rice is grown in close proximity to glyphosate-tolernat crops. If differential tolerance to sub-lethal rates of glyphosate exists among rice (Oryza sativa) cultivars, these cultivars could be utilized in breeding programs or glyphosate-drift sensitive areas. Field and greenhouse experiments were conducted in 2006 and 2007 to examine differences among rice cultivars in response to sub-lethal rates of glyphosate, and to examine imidazolinone-tolerant rice response to imazethapyr and sub-lethal rates of glyphosate applied sequentially to determine the potential for either herbicide to predispose rice to greater injury. In the field …

Effect Of Supplemental Trace Mineral Source (Organic Versus Inorganic) On Bull Semen Quality, Matt Rowe

Graduate Theses and Dissertations

Studies indicate that organic forms of trace minerals can improve cow reproductive performance, particularly during periods of stress. However, limited information is available on the effects of organic trace mineral supplementation on bull fertility. The objective of this study was to evaluate the effect of organic versus inorganic trace mineral supplementation on bull semen quality before and after freezing, as measured by computer-assisted sperm analysis (CASA). Angus and Balancer bulls were assigned to inorganic (n = 9) and organic (n = 10) trace mineral treatments, based on initial semen quality, breed, body weight, and age. The bulls were maintained in …

Earthworms Of Arkansas And Contributions Of Earthworm Evolutionary Origin And Ecological Group To Nitrogen Cycling In A Model Soil And Tall Fescue System, Peter John Tomlinson

Graduate Theses and Dissertations

Evolutionary origin and ecological niche may impact how earthworm species affect N cycling. Tall fescue (Lolium arundinaceum (Schreb) S. J. Darbysh) infection with the toxic endophyte Neotyphodium coenophialum Glenn, Bacon & Hanlin (E+) may influence earthworm communities in soil compared to non-toxic endophyte (NE+) infected tall fescue. Conversely, different earthworms may contribute different amounts of N to E+ vs. NE+ tall fescue. A field survey was conducted from January 2007 to January 2008 to determine the impact of E+ and NE+ tall fescue, planting date, and seasonal variables, e.g. soil temperature and moisture, on earthworm species, abundances, and population …

Determination Of Poultry Litter's Nitrogen-Fertilizer Value For Winter Wheat Production, Brett Lee Gordon

Graduate Theses and Dissertations

Nitrogen (N) availability in poultry litter (PL) applied in the fall as a nutrient source for winter wheat (Triticum aestivum L.) has not been adequately characterized. Our objective was to determine a potentially available N (PAN) coefficient based on the inorganic-N fertilizer equivalence (FEQ) of fall-applied PL to winter wheat via field and laboratory research. Wheat grown at six site-years received 0, 84 and 168 kg N ha-1 as PL applied preplant and/or at-planting. The FEQ of PL-N was based on growth and yield responses of wheat fertilized with 22 to 191 kg N ha-1 applied in late winter as …

Characterization And Molecular Analysis Of University Of Arkansas Peach, Prunus Persica (L.) Batsch, Flesh Types And Development Of A Post-Harvest Evaluation Protocol For Arkansas Peach And Nectarine Genotypes, Paul James Sandefur

Graduate Theses and Dissertations

This study determined the effect of pre-cold storage treatment on P. persica genotypes, developed a protocol for the evaluation of breeding selection and cultivar storage performance, and provided information on post-harvest performance of these individuals. Additionally, characterization of the peach and nectarine flesh types, validation of endopolygalacturonase (endoPG) DNA markers, and investigation of endoPG marker allele combinations associated with the slow-melting-flesh (SMF) trait were done.

Fruit from 30 individuals were harvested at minimum- and well-mature states. After conditioning for 24 h at 20 ◦C, all 2010 fruit were exposed to 2 min of 1 ◦C 100 ppm chlorinated hydro-cooling, a …

Purchaser Preferences On Carbon Labels: Conventional Vs. Organic Milk, Mustafa Ozkan

Graduate Theses and Dissertations

Over the past several years, there has been growing attention concerning global warming/climate change and how humans are contributors. It is known that agricultural production is a main contributor of greenhouse gas emissions and the livestock sector is particularly significant because it is quoted as having between 3 and 18% of greenhouse gas emissions measured in CO2 equivalent pending different assumptions. Due to this, carbon footprint labeling has been described as a potential tool to inform consumers about greenhouse gases associated with food products and assist them with the necessary information to purchase products that help reduce greenhouse gas emissions. …

Estimating Cost Efficiencies Of Propane Use In Broiler Production: Case Study From Savoy, Arkansas And Trnaca Pri Laborci, Slovak Republic, Zuzana Petrikova

Graduate Theses and Dissertations

This study focuses on analyzing the common practice of U.S. broiler farmers to operate on cash basis instead open credit lines for operating cost of propane gas for heating. Data for analysis were taken over from U.S. ABRF at Savoy and Slovak Farm Univerza at Trnava pri Laborci. Predicting the propane gas usage and propane gas cost was analyzed using the OLS model. It describes impact of selected factors on gas usage and cost. The overall purpose of the thesis is to find out which approach from designed scenarios is more economically efficient for farmer: (a) to pre-purchase propane gas …

Marketing Margins Of Strawberries 2006-2010 Shipping Point-Terminal-Retail Price, Matej Mikle Barat

Graduate Theses and Dissertations

This thesis examines vertical price relationships for fresh strawberries. Specifically, the focus is on three stages of the vertical chain. The first stage is the shipping point. Shipping points represent major strawberry production regions and are the closest price point to the farm. The second stage is the terminal market. Terminal markets are wholesale markets in major US cities. The third stage is the retail level. Retail level prices are measured as average supermarket prices in the same cities for which terminal market prices are available. Using weekly data, markup equations are estimated from upstream to downstream levels of the …