Life Sciences Commons^™

Calorimetry And Body Composition Research In Broilers And Broiler Breeders, Justina Victoria Caldas Cueva

Graduate Theses and Dissertations

Indirect calorimetry to study heat production (HP) and dual energy X-ray absorptiometry (DEXA) for body composition (BC) are powerful techniques to study the dynamics of energy and protein utilization in poultry. The first two chapters present the BC (dry matter, lean, protein, and fat, bone mineral, calcium and phosphorus) of modern broilers from 1 – 60 d of age analyzed by chemical analysis and DEXA. DEXA has been validated for precision, standardized for position, and equations and validations developed for chickens under two different feeding levels. These equations are unique to the machine and software in use. Research in broilers …

Stink Bugs: Spatial Distribution, Pecan Phenological Susceptibility And Sampling Program, Brian Cowell

Graduate Theses and Dissertations

An effective management program for stink bugs (SBs) in pecan groves requires knowledge of: stages of the pecans susceptible to SB damage; strata of the tree with SB damaged nuts; a practical SB monitoring method; and, effects of landscapes contributing SBs into pecan groves.

Stink bugs produced feeding punctures in pecan shucks at all phenological stages. Pecans punctured before the dough stage drop from the tree. Kernel damage occurs in the pecans’ dough stage, whereas mature pecans are not damaged.

The pecans collected from the whole tree using the tree shaker had significantly less punctures than the pecans collected from …

Impacts Of Feedstock And Parboiling Conditions On Quality Characteristics Of Parboiled Rice, Kanokporn Leethanapanich

Graduate Theses and Dissertations

Parboiling involves soaking, steaming, and drying, and is known to improve head rice yield (HRY), remove chalkiness, and retain nutrients. Because of an increasing number of rice cultivars developed, commingling of rice may happen during harvesting, distributing, or storage. Using commingled rice with a wide range of gelatinization temperatures (To) as a feedstock may cause inconsistent parboiled rice products. Therefore, this study was aimed at investigating the effect of soaking temperature and steaming duration on the quality of parboiled, commingled rice. Rough rice samples of individual or commingled rice cultivars with different To ranges were soaked at different temperatures (25, …

Hydrology-Biology Response Relationships In The Ozark Highlands, Dustin Thomas Lynch

Graduate Theses and Dissertations

I examined flow-ecology relationships among stream communities in the Ozark Highlands, USA. I sampled fish, crayfish, and benthic macroinvertebrates during two consecutive summers, including a drought year (2012) and a flood year (2013). Biological response variables related to community structure were assessed via two different statistical methods: an Information Theoretic approach relating response variables to a priori selected predictor variables incorporating hydrology, habitat, geomorphology, and water quality, and canonical ordination using forward selection to relate these same response variables to a large assortment of hydrologic metrics. In addition to assessing metrics related to predicted natural flow, flow alteration at gaged …

Soybean Seed Quality And Vigor: Influencing Factors, Measurement, And Pathogen Characterization, Kimberly Ann Cochran

Graduate Theses and Dissertations

High seed vigor (SV), or the ability of seed to germinate and grow in a stressful environment is important, as many field emergence conditions are stressful for germination. Soybean SV can be affected by cultivar, seed storage environment conditions, the growing environment during seed development, crop management practices such as foliar fungicide applications, pathogens, and other factors. To assess the effects of some of these factors on soybean, the objectives of this work were to determine 1. the effect of cultivar and foliar azoxystrobin application on soybean yield, germination, vigor, microflora, and their relationships under harvest delay conditions; 2. if …

Pythium: Characterization Of Resistance In Soybean And Population Diversity, Keiddy Esperanza Urrea Romero

Graduate Theses and Dissertations

Pythium spp. are an important group of pathogens causing stand losses in Arkansas soybean production. New inoculation methods and advances in molecular techniques allow a better understanding of cultivar resistance and responses of Pythium communities to cultural practices. The objectives of this research were to i) characterize the resistance of soybean to P. aphanidermatum with two phenotyping assays that evaluated the seed rot phase of the disease; and ii) understand the effect of long term crop rotation on species diversity and iii) to determine the effect of location, temperature and continuous soybean and soybean-rice rotation on Pythium spp. diversity in …

Investigations Of Ethylene And Ethylene Inhibition, Ball Lie, And Synthetic Turf Color, William Daniel Strunk

Graduate Theses and Dissertations

This dissertation is comprised of several studies over three unrelated areas of focus. Chapters two and three investigate the role of the hormone ethylene on growth of creeping bentgrass through (1) exposure of turf to exogenous ethylene and (2) testing an ethylene inhibiting compound for use to alleviate stress related injury. Previous research demonstrated a correlation of stress injury and ethylene and lessening of injury through ethylene inhibition, but little work has been conducted evaluating the direct effects of ethylene. These studies failed to confirm findings in previous research. Chapters four and five aim to illustrate the impact of turfgrass …

A Morpho-Physiological Analysis Of Diverse Drought Resistant And Sensitive Rice Genotypes To Identify Distinguishing Anatomical Root Phenes, Clinton Philip Greub

Graduate Theses and Dissertations

A set of 37 genotypes selected from a survey of over 200 diverse germplasms, for their diverse drought tolerance mechanisms, were analyzed in this study for root physiological traits that are indicative of different drought resistance mechanisms. The genotypes include controls such as the drought sensitive IR64 and Nipponbare, along with the drought resistant Nagina 22 (N22) and Bengal landraces to identify distinguishing phenotypic features of resistant accessions. Anatomical traits studied include total areas of the cross-sections of the stele, cortex, aerenchyma, cortical-cell, and xylem tissue; the number of aerenchyma, xylem vessels, cortical cell file number and size that together …

Alliaria Petiolata (M.Bieb.) Cavara & Grande [Brassicaceae], An Invasive Herb In The Southern Ozark Plateaus: A Comparison Of Species Composition And Richness, Soil Properties, And Earthworm Composition And Biomass In Invaded Versus Non-Invaded Sites, Jennifer D. Ogle

Graduate Theses and Dissertations

Invasive species are widely recognized as organisms that severely alter ecosystem processes in the habitats to which they are introduced. Alliaria petiolata is one of the most important invasive plants in forests of the northern United States. This study examined the geographic distribution of the plant in the southern Ozarks, as well as the effect that it may be having on natural processes within forests of the region by comparing plant species richness, plant cover, and soil properties in invaded and non-invaded plots. It was found that A. petiolata is not significantly altering species richness, cover, or soil properties in …

Effect Of Nitrogen Fertilizer Rates And Two-Spotted Spider Mite Incidence On 'Strawberry Festival' Strawberry Cultivar Performance, Megan E. Mcgovern

Graduate Theses and Dissertations

The decline in strawberry (Fragaria x ananassa Duch.) production in Arkansas over the last 50 years has sparked an interest in the use of season extension techniques to improve yield and fruit quality. High tunnel strawberry production has the potential to become a profitable and sustainable production system; however, information on nutrient and pest management is limited.

The overall objective of this study was to determine the response of ‘St. Festival’ strawberry cultivar to different nitrogen fertilizer rates in order to develop a fertilization program for strawberries grown under high tunnel production systems. Experiments were conducted at the University of …

Genetic Variation And Species Distribution Of Subterranean Termites In The Southeastern U.S. Focusing On Family Structure And The Invasive Formosan Subterranean Termite, Mark Allan Janowiecki

Graduate Theses and Dissertations

This work applies molecular genetic tools to distinguish the identity and understand the biology of termites, particularly Reticulitermes Holmgren and Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) in the southeastern U.S. Termites are important economic pests costing billions of dollars annually to Americans but also are important wood decomposers in natural settings. Molecular tools are essential for species identification because of the morphological ambiguities among species. The cryptic nest structure of subterranean termites which prevents adequate sampling makes molecular genetic tools essential to examine an entire colony.

A molecular diagnostic technique was created to differentiate Coptotermes formosanus, an invasive species in the …

Characterization Of The Effects Of Bfgf And Gsk3Β Inhibitors On Embryoid Bodies Derived From Human Pluripotent Stem Cells, Jonathan Earls

Graduate Theses and Dissertations

Embryoid body (EB) formation is a common first step in many human pluripotent stem cell (hPSC) differentiation protocols. Previous work suggests that EBs are sensitive to growth factor withdrawal if they are derived from hPSCs maintained in feeder independent media such as mTeSR1. To promote cell survival, EBs generated from mTeSR1-adapted hPSCs are sometimes cultured in a medium that contains basic fibroblast growth factor (bFGF), a trophic factor often used in hPSC cultures to maintain self-renewal. This distinguishes feeder independent hPSCs from feeder dependent hPSCs. The purpose of this study was to characterize the effects of bFGF as well as …

The Functional And Distributional Ecology Of Mycetozoans Under Changing Edaphic And Climatic Dynamics, Geoffrey Lloyd Zahn

Graduate Theses and Dissertations

Investigations into the distribution and ecosystem functions of fruiting amoebae revealed that local-scale environmental conditions can largely explain broad biogeographical patterns in species assemblage, the way in which amoeboid predators shape bacterial communities and how this top-down influence may affect global biogeochemical processes in a changing climate. The distribution and assemblage of protosteloid amoebae on the islands of New Zealand and Hawaii did not yield any expected patterns of island biogeography, and conformed to other global regions studied. The strongest predictor of species richness in a given region was sampling effort and these species do not appear to have any …

Physiological Responses Of Cotton Genotypes To Water-Deficit Stress During Reproductive Development, Cristiane Pilon

Graduate Theses and Dissertations

Drought stress is one of the major abiotic factors affecting crop growth and limiting production worldwide. Cotton genotypes vary in drought tolerance, and the effects of drought stress on the anatomy and physiology of cotton leaves and roots have been reported. However, information on physiological and metabolic processes of leaves and flowers of modern cotton cultivars under water-deficit stress during reproductive development is not well elucidated. It was hypothesized that water-deficit stress during squaring and flowering stages would impair stomatal conductance and photosynthetic efficiency of leaves, which consequently would result in osmotic adjustment through accumulation of compatible solutes, increased activity …

Preferences And Nutrient Composition: The Impact Of Flour Types On Battered Fried Food, Lobat Siahmakoun

Graduate Theses and Dissertations

This study investigated the impact of different flour-batter types on protein rich food in regard to people’s overall liking and sensory preferences (saltiness, flavor, texture, moisture, and color). In addition, all battered fried chicken, fish, shrimp, pork, and beef were analyzed for fat, calories, and protein content in the Central Analytical Laboratory at the University of Arkansas. Two hundred thirty-five participants completed the questionnaire containing five major sections. Respondents evaluated samples of battered fried chicken, fish, shrimp, pork, and beef using all-purpose flour (APF), rice-flour (RF), and potato flour (PF). Data was analyzed using binomial analysis and paired sample t-test …

Effects Of Food Label Education On Consumers' Sensory Perception And Awareness In Chicken Meat, Shilpa Samant

Graduate Theses and Dissertations

Recently, sustainability and process-related label claims have gained immense popularity especially for meat products like chicken. Apart from providing consumers with required product information, these labels have an impact on consumer perception and purchase behavior. The objective of this study was to determine whether providing label information affects consumers’ awareness and attitude toward the claims found on chicken products. Additionally, it was analyzed if enhanced label understanding affects consumers’ sensory and quality perceptions along with purchase intent. A total of 110 participants were randomly distributed into 1 of 3 types of education sessions: (1) reading a flyer (passive learning), (2) …

Lidar And Machine Learning Estimation Of Hardwood Forest Biomass In Mountainous And Bottomland Environments, Bowei Xue

Graduate Theses and Dissertations

Light detection and ranging (lidar) has been applied in various forest applications, such as to retrieve forest structural information, to build statistical models for identification of tree species, and to monitor forest growth. However, despite significant progress in these areas, the choice of regression approach and parameter tuning remains an ongoing critical question. This study focused on choosing the right spatial generalization level to transform lidar point clouds to 2D images which can be further processed by mature image processing and pattern recognition approaches. It also compared the prediction ability of popular machine learning algorithms applied to aboveground forest biomass …

Spatiotemporal Fluctuations Of Olfactory Stimuli And Its Detection By An Optical Method, Mitu Chandra Acharjee

Graduate Theses and Dissertations

Olfactory processing in the mammalian brain is a highly dynamic process, yet most of the olfaction experiments have been studied primarily with static stimuli. Odors in the natural environment are transported by turbulent flow of air or water. Natural odorants have fluctuations in concentration and it changes rapidly with time. These rapid fluctuations may pose some challenges to identifying an odor; on the other hand, the variation itself may provide important clues about the odor source. The goal of this thesis project was to create a similar odorant environment like the rapid odor fluctuations encountered in nature – to meet …

The Impact Of A Ballot Education Program On Arkansas Voters, Kristin Netterstrom Higgins

Graduate Theses and Dissertations

The University of Arkansas Division Of Agriculture’s Public Policy Center has educated Arkansas voters about statewide ballot issues for 10 years. The ballot issue education program, was evaluated during the 2014 election cycle to determine the program’s impact on voters. This descriptive study sought to describe program participants, to determine knowledge transfer of county agents, to describe knowledge acquisition of program participants, and to measure whether people who attended Cooperative Extension Service presentations made informed choices on Election Day. Researchers found that program participants were mostly older, educated, White women. There were increases in knowledge among participants who read fact …

Identifying Leadership Perceptions Of Desired Competencies Of Agricultural Sales Students And Agricultural Sales Industry Professionals, Sarah Beann Wright

Graduate Theses and Dissertations

The two articles presented in this thesis used both quantitative and qualitative research methods to evaluate competencies among agricultural business students and agricultural sales professionals respectively. In the first study, students enrolled in the Fall 2014 agribusiness sales course at [State] University (n = 97), participated in a pre and post evaluation comprised of leadership assessments to determine the change in introversion and extroversion, task-oriented and relationship-oriented, and finally strength characteristics over the time period of an academic semester. Students presented to be from a variety of leadership backgrounds. Posttest results reported students being both high task (62.89%) and high …

The Impact Of Herbicide-Resistant Rice And Hybrid Rice Technology On Weedy Rice Evolution, Vijay Singh

Graduate Theses and Dissertations

Weedy rice (Oryza sativa L.) competes aggressively with rice, reducing yields and grain quality. ClearfieldTM rice, is nontransgenic herbicide-resistant (HR) rice introduced in 2002 to control weedy rice, has resulted in ALS-resistant weedy rice due to gene flow. Volunteers of ClearfieldTM rice (F2) accelerate the HR weedy rice evolution by acting as agents of gene flow. Weedy rice (89) collected from 11 counties in Arkansas were screened for resistance in a field experiment in Stuttgart (2011). Seventy-nine percent of accessions were resistant to imazethapyr and harbored S653N mutation. These HR weedy accessions were outcrosses of ClearfieldTM rice and weedy rice. …

The Ability Of Select Probiotics To Reduce Enteric Campylobacter Colonization In Broiler Chickens, Sandip Shrestha

Graduate Theses and Dissertations

Campylobacter is the leading cause of foodborne illness worldwide and is often associated with consumption and/or mishandling of contaminated poultry products. Probiotic use in poultry has been an effective strategy in reducing other enteric foodborne pathogens but not consistently for Campylobacter. As Campylobacter resides and utilizes intestinal mucin for growth, isolates selected on the basis of mucin utilization might be a strategy to screen for efficacious probiotic bacterium. In this study, bacterial isolates demonstrating increased growth rates in mucin, in vitro (trials 1 or 2), or isolates demonstrating a reduction of Campylobacter counts when co-incubated with mucin, in vitro (trials …

Meat Quality Of Broiler Breast Fillets With White Striping And Woody Breast Muscle Myopathies, Vishwesh Vijay Tijare

Graduate Theses and Dissertations

The global poultry industry has been faced with emerging broiler breast meat quality issues known as white striping and woody breast. Two experiments were conducted to evaluate effects of white striping and woody breast hardness on meat quality traits in broiler breast fillets. Birds were processed at 8 wk (Exp.1) and at 6 and 9 wk of age (Exp.2), whereas deboning was carried out at 4 and 2 h postmortem in Exp.1 and 2, respectively. Fillets were categorized as: normal for both white striping and woody breast (NORM); mild for white striping and woody breast (MILD); severe for white striping …

Comparison Of Different Modulators That Affect Macrophage Activation In Vitro, Alda Alexa Díaz Pérez

Graduate Theses and Dissertations

Inflammation is known as a mechanism to regulate and control infections as well as promote tissue repair. Macrophages (Mф) are known to be a major cell type in the initiation, sustainability and resolution of inflammation. Moreover, Mф are essential for the remodeling process that is also known as the wound healing response. The objective of this research was to compare five modulators (acetylsalicylic acid (ASA), dexamethasone (DEX), prostaglandin E2 (PGE2), iloprost, and resolvin D1 (RvD1) for their anti-inflammatory effects on macrophages in vitro. Then, Mф phenotype in terms of gene expression and secreted cytokine response was determined. Our study compared …

Production And Characterization Of Islet Amyloid Polypeptide Using Recombinant Technology, Emilio Duverna

Graduate Theses and Dissertations

Islet amyloid polypeptide (IAPP) also called amylin is an amyloid-forming protein; IAPP is a proteinaceous hormone that comprises 37 amino acid residues. It is secreted along with insulin from the pancreatic β-cells to help it regulate the uptake and removal of glucose in the bloodstream. IAPP has been observed in the amyloid deposits found in pancreatic β-cells of most patients suffering from type II diabetes mellitus. This research project aims at producing recombinant amylin peptide. To achieve this goal, we used the pBAD plasmid vector which we introduced into Escherichia coli to express the peptide. Although the vector was successfully …

Cost-Benefit Analysis And Potential Spillover Effects Of Farmer Field Schools In Sub-Saharan Africa: The Case Of Cocoa, Francis Tsiboe

Graduate Theses and Dissertations

This thesis consists of two studies analyzing the first phase of the Cocoa Livelihood Program (CLP-I), a current World Cocoa Foundation (WCF) development project, sponsored by the Bill and Melinda Gates Foundation and aimed at improving the livelihood of small scale cocoa producers in Sub-Saharan Africa. The first study uses a difference-in-differences econometric model to estimate yield enhancements attributable to farmer field schools which CLP implements. The results show a 32%, 34%, 50% and 62% increase in cocoa yield for Ghana, Côte d’Ivoire, Nigeria and Cameroon, respectively. These yield enhancements have the potential to increase income by 26%, 29%, 48%, …

Effect Of In Ovo Feeding Of Dextrin-Iodinated Casein On Hatch, Growth And Gene Expression In Broilers., Shaymaa Mostafa Ibrahim Abousaad

Graduate Theses and Dissertations

Six experiments were conducted to determine effects of in ovo feeding of dextrin (Dext, 18% maltodextrin, 10% potato starch dextrin) and iodinated casein (IC) on hatch and growth performance in broilers. In each experiment, approximately 15,000 eggs (2500 eggs per group) were treated at 18.5 to 19 d of embryonic development. Three studies indicated that hatch weights were higher in chicks receiving Dext or Dext containing IC at 240 or 480 µg/mL and only one study indicated negative effects of Dext or 240 µg IC/mL saline on hatch weight. In one growth study, broilers provided Dext or Dext with IC …

Food Waste At Retail, Erin G. Killeen Davis

Graduate Theses and Dissertations

Food waste at retail represents forgone sales and embodies store management and disposal costs. Fresh produce is the largest contributing sector to food waste at retail and bulky, seasonal products are an added challenge when stores experience a high waste event. In order to improve, retailers need to better understand the costs of food waste, as well as how management strategies can impact these costs.

Using pumpkins as an example of bulky, seasonal products, a twofold research project was conducted to better understand contributors to, and costs of food waste at the retail level. In part one, using data from …

Population Structure Of Central Stoneroller (Campostoma Anomalum) On The Ozark Plateau In Arkansas And Missouri, Mallory Jane Jeffers

Graduate Theses and Dissertations

Stream fishes on the Ozark Plateau have been influenced both by historic events (i.e. vicariance versus dispersal) and ecological forces (i.e. flow regime). To examine the role of these processes, genetic structure of Central Stoneroller (Campostoma anomalum), an ecologically important omnivorous minnow with a broad distribution and elevated abundance, was evaluated across populations in the White River drainage of the Ozark Plateau in Arkansas and Missouri. Fin clips of five to eight individuals were taken at each of 20 sites (N=138 individuals; average=6.9), selected so as to represent two different flow regimes: intermittently flashy (N=10 sites; N=73 individuals; average=7.3/ site) …

Effect Of Feeding Regimen And Age On Lipid Metabolism In Broiler Breeder Hens And Progeny, Nirun Boonsinchai

Graduate Theses and Dissertations

Age of hens and feed allocation can affect egg yolk lipid compositions which in turn directly relate to chick quality. A series of experiments were conducted to determine the effects of age and feeding programs on lipid metabolism in breeder hens and progeny. In the first trial, the rate of yolk absorption and fatty acid profiles in the yolk were compared among 28, 35, and 49wk old hens. The results revealed that the rate of yolk absorption was higher, but the absolute amount of fatty acids absorbed was lower in young hens than in the old hens. The second trial …