Digital Commons Network^™

Identifying Genetic Factors Influencing Sperm Mobility Phenotype In Chicken Using Genome Wide Association Studies, Primordial Germ Cell Transplantation, And Rnaseq., Sohita Ojha

Graduate Theses and Dissertations

Sperm mobility is a major determinant of male fertility in chicken. In spite of low heritability of reproductive traits, sperm mobility has high heritability index which suggests presence of quantitative trait loci (QTLs) governing the trait. Our research focused on three objectives: i) to identify the QTLs affecting low mobility phenotype in chicken, ii) to understand the impact of Sertoli-cells and germ cells interactions in influencing the mobility phenotype and iii) to identify the genes and gene networks differentially expressed in male and female PGCs. To detect the QTLs, genome wide association studies (GWAS) was conducted which revealed the presence …

The Economic Benefits Of The South African Agricultural Research Council’S Wheat Breeding Program: 1992–2015, Matthew James Coale

Graduate Theses and Dissertations

Although classified as an upper middle-income country by the World Bank, food insecurity is still a concern throughout South Africa, as was evident in 2014–2015 when a drought left 22% of households food insecure. As such, agricultural research in South Africa is needed specifically in plant breeding to increase yields and help mitigate future food insecurity. To fill this need, the South African government funds the Agricultural Research Council (ARC), which conducts holistic research on wheat and other crops. Wheat is important to South African food security; due to the significant drop in wheat area planted since the abolishment of …

Shallow Aggregate Ebb-And-Flow System For Greenhouse Lettuce Production, Joseph Chidiac

Graduate Theses and Dissertations

A novel soilless technique for the production of lettuce was developed and evaluated for its viability for ornamental greenhouse growers adapting their ebb-and-flood irrigation benching systems to diversify into growing lettuce, without having to purchase the conventional nutrient film technique (NFT) or deep flow technique (DFT) hydroponic systems. The experimental design was a three by four factorial, with three treatments for aggregate depth (19, 38, and 57 mm) and four treatments for irrigation frequency (once every 1, 2, 4, or 8 hours), for a total of twelve treatment combinations. Each treatment was replicated three times in a randomized complete block …

Modelling The Impact Of National Development Strategies For The East African Rice Sector, Florence Muthee

Graduate Theses and Dissertations

The 2008 food crisis prompted many food importing nations to reconsider the need to be self-sufficient especially in their staple food needs. This awakening led to the launch of the Coalition for Africa Rice Development (CARD) initiative with a goal to double rice production in Africa. Under the CARD umbrella member countries drafted individual National Rice Development Strategies (NRDS). This study is a quantitative assessment of four East African countries’ NRDS: Kenya, Rwanda, Tanzania and Uganda within dynamic global rice economy models. The NRDS targets and strategies are not realistic and included under estimation of rice consumption for Kenya, an …

New Technologies For Evaluating Putting Green Surface Characteristics, Daniel Patrick O'Brien

Graduate Theses and Dissertations

Golf course putting greens require a high level of inputs predicated on timely, well informed decisions. Putting green quality is ultimately defined by performance of the turfgrass, and this performance encompasses both (i) the health and vitality of the turfgrass plants, and (ii) the ability of the turfgrass to exist as a playing surface, as it interacts with the golf ball. For golf course superintendents, accurately and efficiently assessing moisture levels and nutrient status are critical for guiding maintenance practices. This research sought to examine new ways for measuring each of these parameters, and compared them to ground-truth data and/or …

Economic And Policy Evaluations And Impacts Of The National Rice Development Policy Strategies In Malaysia: Self-Sufficiency, International Trade, And Food Security, Roslina Binti Ali

Graduate Theses and Dissertations

Despite the fact that the recent rice policy has been moving to a strategy of self-sufficiency while the status quo of the national rice economy remains ambiguous, Malaysia has made an extreme policy decision to pursue an autarky economy in its rice sector, thus closing borders from the international markets in the future. The goal of this dissertation research is to comprehensively evaluate a deep-rooted rice policy in Malaysia and analyze the holistic impacts of the self-sufficiency and international trade policies at the national and farm-household levels, utilizing economic frameworks. The protectionist policy measures using a Policy Analysis Matrix reveals …

A Comparative Life Cycle Assessment Of Nutritionally Equivalent Meals With And Without Pork, Kelli Young

Graduate Theses and Dissertations

The following report details a life cycle assessment of several dietary and meal scenarios with and without pork. The goal of the LCA was to identify the impacts of greenhouse gas emissions, water use, and land use of pork containing and porkless diets and meal plans in a field-to-fork analysis. The dietary and meal plan scenarios are iso-caloric meaning they contain the same number of calories. The first set of diets is based on a USDA consumption pattern, 2000 kcal per day. This diet was used to create three other dietary scenarios with and without pork. The USDA recommended food …

Time Series Forecast Analysis In Wholesale Broiler Markets, Christopher R. Sims

Graduate Theses and Dissertations

In 2016 the chicken industry provided nearly 1.2 million jobs, 68 billion dollars in wages, 313 billion dollars in economic activity and 24 billion dollars in government revenue (John Dunham & Associates, Inc., 2016). Broiler production has changed dramatically from the early 90’s to the turn of the 21st century. Technological advancements, continuous improvements, production efficiencies and industry changes have made the industry the global market it is today. The poultry industry is an extremely volatile market with prices constantly fluctuating in response to input price volatility and demand and supply changes. These changes are often driven by world economic …

Transcriptome-Based Gene Networks For Systems-Level Analysis Of Plant Gene Functions, Chirag Gupta

Graduate Theses and Dissertations

Present day genomic technologies are evolving at an unprecedented rate, allowing interrogation of

cellular activities with increasing breadth and depth. However, we know very little about how the

genome functions and what the identified genes do. The lack of functional annotations of genes

greatly limits the post-analytical interpretation of new high throughput genomic datasets. For plant

biologists, the problem is much severe. Less than 50% of all the identified genes in the model plant

Arabidopsis thaliana, and only about 20% of all genes in the crop model Oryza sativa have some

aspects of their functions assigned. Therefore, there is an …

In The Field The Women Saved The Crop: The Women’S Land Army Of World War Ii, Denna M. Clymer

Graduate Theses and Dissertations

The Women’s Land Army brought together rural and urban sectors of the United States in a climate of national and regional crisis. By the time the country was cast into war, the agricultural sector was already caught in a downward economic spiral that drove away laborers. With demand falling, and farms propped up only by experiments in subsidy and parity, when military and industrial jobs emerged in urban areas, farm laborers became scarce. At the same time the war created jobs for men outside of the agricultural sector, farm prices recovered and demand soared, forcing farmers to look to women …

Animal Welfare Frames: How Social Media Messages Bridge The Gap Between The Protein Industry And Consumers, Olivia Norton

Graduate Theses and Dissertations

The two articles in this thesis used content analysis to analyze and compare animal welfare related website and Twitter content of the top five animal protein producing companies in the United States. In the first article, the animal welfare website content of Cargill, Tyson Foods Inc., Smithfield, JBS® and Sysco were analyzed for persuasive frames, common topics, and key terminology to describe their corporate positions on animal welfare. Sysco’s main page devoted to animal welfare dominated the word count with 1,045 words, while JBS®’s main animal welfare page used only 265 words to communicate the company’s views. The most commonly …

Habitat Ecology, Trophic Interactions, And Distribution Of Endangered Himalayan Musk Deer In The Nepal Himalaya, Kapil Kishor Khadka

Graduate Theses and Dissertations

This dissertation seeks to explore and assess the habitat selection, trophic interactions and distribution of Himalayan musk deer. Chapter one deals with seasonal diet analysis of musk deer along with the overlap in consumption with livestock during summer. Microhistological technique was employed to assess dietary consumption. Results showed that Abies spectabilis, Pinus wallichiana, and Berberis species constituted the major portion of musk deer’s diet. Dietary breadth measured by the Shannon index was found higher in winter compared to summer. Although musk deer and livestock shared a considerable number of plant species in their diets, the consumption however was significantly different …

Piglet Gut Microbiota Responses To Exposure To Outdoor Simulated Environment And Formula Feeding, Nguyen Vo

Graduate Theses and Dissertations

Several lines of evidence suggest that early-life gut microbiota composition is a crucial determinant of the susceptibility to diseases later in life. Understanding the evolution of early-life gut microbiota and critical factors that can modify this microbial community will espouse the prevention or reversion of health risk originating from dysbiosis of the gut microbiota in the early stage. In this research, we hypothesized that alterations in the environment (simulation of rural conditions by soil exposure) and feeding mode (breastmilk versus formula milk) will have significant impacts on the establishment of the gut microbiota in early life. At first, in literature …

Developing Algorithms For Quantifying The Super Resolution Microscopic Data: Applications To The Quantification Of Protein-Reorganization In Bacteria Responding To Treatment By Silver Ions, Sai Divya Challapalli

Graduate Theses and Dissertations

Histone-like nucleoid structuring proteins (HNS) play significant roles in shaping the chromosomal DNA, regulation of transcriptional networks in microbes, as well as bacterial responses to environmental changes such as temperature fluctuations. In this work, the intracellular organization of HNS proteins in E. coli bacteria was investigated utilizing super-resolution fluorescence microscopy, which surpasses conventional microscopy by 10–20 fold in spatial resolution. More importantly, the changes of the spatial distribution of HNS proteins in E. coli, by addition of silver ions into the growth medium were explored. To quantify the spatial distribution of HNS in bacteria and its changes, an automatic method …

Effect Of Endophyte-Infected Tall Fescue Toxins On Growth Performance And The Microbial Community In The Rumen And Feces In Pregnant Ewes, Saleh Alrashedi

Graduate Theses and Dissertations

Fifty pregnant Katahdin ewes grazed pastures with high (HE) and moderate (MI) levels of Neotyphodium coenophialum-infected tall fescue between February 1 and May 24 to determine the impacts of tall fescue toxins on body weight (BW), body condition scores, FAMACHA scores, fecal egg counts (FEC), and serum Cu, Zn, prolactin, and non-esterified fatty acids (NEFA). Within those 50 ewes, 15 were selected randomly for fecal and rumen sampling to assess the impacts of HE and MI on the microbiome community. Total bacterial DNA was extracted from rumen and fecal samples, and alpha and beta diversities were used to relate microbiome …

Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black

Graduate Theses and Dissertations

Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) is a commercially available viral biopesticide that targets Heliothines, including Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), the most damaging pest of soybean (Glycine max (L.) Merrill) in the Mid-South. Previous formulations of HearNPV have been well studied; however, no research has been published on current formulations. The first objective of this thesis was to assess the rate of horizontal transmission of HearNPV in a soybean field infested with H. zea when HearNPV was applied as a bio-insecticide, and to identify arthropods that are important obligate carriers in dissemination. HearNPV spread 200 feet in 3 fields, and was …

Fall Risk In Sedentary, Recreationally Active, And Masters Athlete Older Adults, Felicia Elizabeth Squires

Graduate Theses and Dissertations

The purpose of this study was to examine whether different habitual activity levels may affect balance ability in older adults. Balance must be studied as poor balance increases likelihood of falls. This study examined activity levels in older adults and effect on balance ability. Fifty-nine older adults aged 66.5 ± 9.5 participated. Three groups were separated by physical activity level. First group had 13 masters athletes, older adults performing least 150 minutes of aerobic activity a week and competing in nationally sanctioned event within the last six months. Twenty-seven older adults comprised recreationally active group performing at least 150 minutes …

A Molecular Diagnostic Survey Of Pathogens And Parasites Of Honey Bees, Apis Mellifera L., From Arkansas And Oklahoma, Dylan Cleary

Graduate Theses and Dissertations

The health and viability of colonies of the honey bee, Apis mellifera, in the United States have fluctuated dramatically over the past decade. This poses a substantial threat to agricultural production in this country. Currently, no single factor has been identified for this decline. Rather, it has been suggested that the interaction between multiple biotic and abiotic stressors may be responsible. Among these factors are pesticides, habitat loss, climate and weather, parasites and pathogens, and colony management techniques. For this reason, it is important to examine the prevalence of honey bee parasite and pathogen infection at the state level in …

Understanding Intracellular Redox Regulation In Methanogens: Characterization Of The Components And Targets Of The Nadph-Dependent Thioredoxin System From Methanosarcina Acetivorans, Addison Clark Mccarver

Graduate Theses and Dissertations

All cells have a reduced intracellular environment. In the presence of oxygen, the non-specific oxidation of intracellular components leads to the production of reactive oxygen species (ROS) within cells leading to oxidative stress. During oxidative stress labile cofactors (e.g. Fe-S clusters) are lost and deleterious disulfide bonds are formed within proteins. Intracellular redox maintenance systems are used to direct reducing equivalents towards the repair of oxidatively-damaged proteins. The thioredoxin system is the ubiquitous intracellular redox system, found in virtually all species. The canonical thioredoxin system is comprised of a NADPH-dependent thioredoxin reductase (TrxR) that functions to reduced thioredoxin (Trx). Although …

Characterization Of Glyphosate-Resistant Amaranthus Palmeri (Palmer Amaranth) Tolerance To Als- And Hppd-Inhibiting Herbicides, Shilpa Singh

Graduate Theses and Dissertations

Palmer amaranth is a principal weed problem across the United States and is resistant to several herbicide modes of action. By 2008, Palmer amaranth in Arkansas was reported to be resistant to both ALS- and EPSPS-inhibitors, but the predominant resistance mechanisms are yet to be explored. Herbicide options with different modes of action are needed to provide effective Palmer amaranth control and HPPD-inhibitors (e.g. mesotrione) are among these. The goal of this research was to elucidate the resistance profile of Palmer amaranth in Arkansas to ALS herbicides and glyphosate (EPSPS-inhibitor) as well as evaluate the differential tolerance of Palmer amaranth …

Characterization Of Multiple-Herbicide-Resistant Echinochloa Colona From Arkansas, Christopher Edward Rouse

Graduate Theses and Dissertations

Echinochloa species are highly adaptive weeds that have the potential to impact crops in a variety of environments. This has positioned them as the most problematic weeds in a number of USA cropping systems with some species having the distinction of the 'worst herbicide-resistant weeds' in the world. Recent evidence has positioned Echinochloa colona (junglerice) as the most dominant in Arkansas and throughout the Mid-South, USA, especially in rice (Oryza sativa L.) and soybean (Glycine max L.) production fields. A history of extensive herbicide-use for management and a lack of integrated or diverse approaches to management have led to rampant …

Experimental Approaches To Understand And Control Salmonella Infection In Poultry, Yichao Yang

Graduate Theses and Dissertations

Salmonella is a major foodborne pathogen around the world and chickens are the major reservoir to transmit Salmonella into the human food chain. For decreasing the infection of Salmonella, we developed six attenuated live vaccines based on Salmonella Enteritidis (SE) and Typhimurium (ST) for testing the cross-serovar and cross-serogroup protection from the challenge of Salmonella Heidelberg and Campylobacter jejuni. One of the constructed vaccine strain showed ability to protect against challenge from Salmonella Heidelberg. Even though some preventive approaches are able to decrease Salmonella colonization in the gastrointestinal tract of chickens or other farm animals, Salmonella transmission mechanisms remain unclear. …

Role Of Incompatibility Group 1 (Inci1) Plasmid-Encoded Factors On Salmonella Enterica Antimicrobial Resistance And Virulence, Pravin Raghunath Kaldhone

Graduate Theses and Dissertations

Foodborne illnesses are a leading cause of infectious diseases in the world. Among enteric organisms Salmonella is a key pathogen. It’s high prevalence in poultry and other food-animal sources make it imperative to study. Salmonella has the ability to modify its genetic content with help of mobile genetic elements such as plasmids. Incompatibiltiy group 1 (IncI1) plasmids are commonly reported in Salmonella. This study evaluates role on IncI1 plasmids in antimicrobial resistance and virulence in Salmonella. Genetic determinants of resistance and virulence are noted among our IncI1-containing Salmonella isolates. These genetic elements are also transferable and reported to carry respective …

Characterization And Mechanisms Of Anthocyanin Degradation And Stabilization, Nathan Blaine Stebbins

Graduate Theses and Dissertations

Anthocyanins (ACYs) are polyphenol compounds found in nature, which contribute vivid colors to many fruits and vegetables, while also possessing significant health benefits. These pigments range in color from orange-red to blue-violet and could serve as natural colorants to replace artificial additives. There is a great demand from consumers to have fewer artificial compounds in their foods. However, the relatively instability of ACYs must be further understood in order to limit color degradation before they can completely replace synthetic colorants.

ACYs slowly degrade over time, but there is a knowledge gap on their fate and mechanisms causing degradation. In order …

Development And Characterization Of Rice Genotypes For Water Use Efficiency And Drought Resistance, Anuj Kumar

Graduate Theses and Dissertations

Rice, the second largest staple food crop, uses 30% of global fresh water to complete its life cycle worldwide. Water deficits worldwide have become a serious problem affecting rice growth and ultimately grain yield. To solve the water problem globally, improvement of water use efficiency (WUE) and other drought resistance (DR) traits in rice genotypes would be a useful strategy using advanced genomics tools. In this study, our objectives were to 1) analyze phenotypes of the USDA rice mini-core collection (URMC) for WUE and DR related traits, 2) correlate drought response phenes for physiological traits and grain yield in the …

Fungi Of Forests: Examining The Diversity Of Root-Associated Fungi And Their Responses To Acid Deposition, Donald Jay Nelsen

Graduate Theses and Dissertations

Global importance of forests is difficult to overestimate, given their role in oxygen production, ecological roles in nutrient cycling and supporting numerous living species, and economic value for industry and as recreational zones. Fitness of the forest-forming trees strongly depends on microbial communities associated with tree roots. In particular, fungi impact tree fitness: mycorrhizal species provide water and nutrients for the trees in exchange for C, endophytic fungi play key roles in host defense against pathogenic organisms, and saprotrophic fungi decompose dead organic matter and facilitate nutrient cycling. In addition, pathogenic fungal species strongly affect forest fitness. Despite their importance, …

Effects Of Pre-Chiller Temperature On The Microbial Ecology Of Whole Bird Carcass Rinses, Rachael Elizabeth Blevins

Graduate Theses and Dissertations

Upon entering a poultry processing facility, birds are already contaminated with a variety of microorganisms. It is the responsibility of the processor to reduce these numbers to deliver a wholesome product to customers. This is not an easy task as there are ample opportunities for further microbial contamination. Some of these opportunities are obvious. For example, any areas where contaminants could be washed off one bird and onto another are always an area for concern, i.e. the scalder or the chiller. There are numerous opportunities for contamination that are not so obvious. These incidents of contamination are not necessarily due …

Experimental Simulation Of A Cross-Flow Rice Dryer, Sangeeta Mukhopadhyay

Graduate Theses and Dissertations

After harvest, rough rice is dried, then dehulled and typically milled before consumption. A broad objective of the “rice drying process”, which comprises drying and tempering, is to maximize the yield of “whole, intact milled kernels”, quantified by the “head rice yield” (HRY). Since rough rice is commonly dried using cross-flow (CF) dryers in the United States of America, the aim of this research was to assess the effect of drying and tempering treatments on milling yields when rice was dried in an experimentally-simulated CF drying column. First, because airflow rate was found to be the least-studied “drying variable”, its …

Population Dynamics Of Ouachita Dusky Salamanders (Desmognathus Brimleyorum) In A Managed Forest Landscape, Kelly Marie Halloran

Graduate Theses and Dissertations

With anthropogenic alteration of landscapes increasing world-wide, managed forests are increasingly important as providers of ecosystem services including habitat for numerous wildlife species. It is crucial to maintain a balance between timber production and conservation of biodiversity on managed landscapes. Salamander populations can play key roles in the function and diversity of temperate forest ecosystems. Several studies have reported negative effects of forestry on terrestrial plethodontid salamanders, but less research has focused on stream-dwelling species, evaluated mechanisms driving observed shifts in abundance, or described the dynamics of populations residing in managed forests. Using a Before-After-Control-Impact design, we examined the effects …

A Study Of The Prevalence Of Gastrointestinal Nematodes In Goats Obtained From Northwest Arkansas, Christine Rose Weingartz

Graduate Theses and Dissertations

Parasitic helminths have always been an issue in small ruminant production; pathogens that pose great negative impact on goat health and productivity. Insufficient work has been done to document the prevalence of parasitic helminths in the United States, especially in the south and southeast, where the largest goat populations are found.

The aim of this study was to survey the prevalence of infections by gastrointestinal nematodes in goats in Northwestern Arkansas. Gastrointestinal tracts were examined from 41 goats of various locations around Northwest Arkansas. Worm species were identified and population burdens were determined. Coprology was correlated with the actual worm …