Life Sciences Commons^™

Effect Of Morinda Citrifolia (Noni)-Enriched Diet On Hepatic Heat Shock Protein And Lipid Metabolism-Related Genes In Heat Stressed Broiler Chickens, Joshua Flees

Graduate Theses and Dissertations

Heat stress (HS) has been reported to alter fat deposition in broilers, however the underlying molecular mechanisms are not well-defined; therefore, the objectives of the current study were to: (1) determine the effects of acute (2 h) and chronic (3 wk) HS on the expression of key molecular signatures involved in hepatic lipogenic and lipolytic programs; and (2) assess if diet supplementation with dried Noni medicinal plant (0.2% of the diet) modulates these effects. Broilers (n=480 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to two environmental conditions (HS at 35°C vs. thermoneutral condition [TN] at 24°C) …

Growing Up In Tell El-Amarna: An Examination Of Growth And Non-Specific Stress Indicators In New Kingdom Children., Ashley Elizabeth Shidner

Graduate Theses and Dissertations

The health status of the subadult skeletal remains from the South Tombs Cemetery at Tell el-Amarna were assessed by examining fluctuations in childhood growth and rates of skeletal indicators of physiological stress within a biocultural framework. The long bone standardization method outlined by Goode et al. (1993) was used to compare the South Tombs cemetery’s cross-sectional growth data to subadult samples from other cemeteries during which major social, political, and economic changes were taking place. The comparative subadult samples included the HK43 cemetery from Hierakonpolis (Egypt), the African American Cemetery from Cedar Grove (Arkansas), and the St. Martin’s Churchyard from …

Factors Influencing Adoption Of Conservation Agriculture In The Democratic Republic Of The Congo, Willy Mulimbi Byamungu

Graduate Theses and Dissertations

The agricultural sector in the Democratic Republic of the Congo (DRC) is still struggling to cope with its post-independence political and structural instability. From 1961 to 2000, the DRC experienced a decrease of 34% and 37% in daily caloric intake and protein intake, respectively. The DRC’s agriculture sector, led by women (who are the core of subsistence farming), is now being targeted as a potential pathway out of poverty through sustainable development programs. Empowering farmers to increase productivity by educating them to use conservation agriculture (CA), a more sustainable alternative to the traditional slash-and-burn agricultural practice, could contribute to reducing …

Dissecting The Mechanism Of Action Of A Novel Antifungal Peptide, Cody Bullock

Graduate Theses and Dissertations

There is an urgent need for novel treatments for Candida infections. The utility of antimicrobial peptides for antifungal therapy has garnered interest in recent years. One promising family of peptides is the Histatins, a family of naturally-occurring peptides secreted into the oral cavity that display antimicrobial activity. Histatin 5 is a twenty-four amino acid peptide with strong antifungal activity. Studies from our laboratory have identified a small histatin-derived peptide, KM29, that yields fungicidal activity 10-fold greater than Histatin 5 against multiple Candida species. Our laboratory has focused on understanding the mechanism of action of KM29 to further develop it as …

Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd

Graduate Theses and Dissertations

The natural flow regime exerts primacy over lotic ecosystem patterns and processes. However, little work has examined the influence of flow regime on instream and riparian carbon (C) dynamics in minimally-impacted, temperate forested systems. To date, most research efforts have focused on characterizing C movement and transformations across biomes and land use categories; however, flow regime represents an overlooked, finer level of detail that may drive differences in ecosystem function. My dissertation objective was to measure C fixation and movement within and across multiple environmental spheres (e.g. within stream channels, between stream surfaces and the atmosphere, and from riparian soils …

Assessment Of Melanocyte-Specific Primary And Memory Autoimmune Responses In Vitiligo-Prone Smyth And Vitiligo-Susceptible, Non-Expressing Brown Line Chickens, Daniel Morales Falcon

Graduate Theses and Dissertations

Vitiligo is an acquired de-pigmentation disorder characterized by the post-natal loss of epidermal melanocytes (pigment-producing cells) resulting in the appearance of white patches in the skin. The Smyth line of chicken is the only model for vitiligo that shares all the characteristics of the human condition including: spontaneous post-natal loss of melanocytes, interactions between genetic, environmental and immunological factors and associations with other autoimmune diseases. In addition, an avian model for vitiligo has the added benefit of an easily accessible target tissue (a growing feather) that allows for the repeated sampling of an individual and thus the continuous monitoring of …

Determinants Of Hydration In Children: The Role Of Physical Activity And Parental Dietary Habits, Hyun-Gyu Suh

Graduate Theses and Dissertations

PURPOSE: The purpose of these studies was 1) to examine the factors that influence the water intake in children and 2) to identify the optimal time window to assess hydration status that would be equivalent to 24-hour urine sample in children. METHODS: Study 1: Data for 200 parents (age:3-13y, female:62%, BMI:28.4±7.0kg∙m-2) and 200 children (age:7.5±2.9y, female:44%, BMI:17.7±3.9kg∙m-2) were recruited. Subjects recorded their fluid and food consumption on the 2-day diary, and food data were analyzed by using the Nutrition Data System for Research (NDSR) program. Physical activity levels were assessed with the International Physical Activity Questionnaire (IPAQ). All urine samples …

Investigation Of Bacterial Taxa As Biomarkers Of Fescue Toxicosis And Heat Stress In Grazing Beef Cows, Sarah Katherine Chewning

Graduate Theses and Dissertations

Fescue toxicosis in grazing beef cattle is caused by consumption of Ergot alkaloids associated with tall fescue (toxic fescue) and is responsible for substantial economic loss to the U.S. beef industry. Cattle consuming toxic fescue suffer adverse physiological responses, such as: hyperthermia, increased respiration rate (RR), poor reproduction and growth performance. Other adverse responses to fescue toxins include the retention of a winter hair coat and vasoconstriction in the extremities, which can lead to tissue necrosis. Identifying cattle with reduced susceptibility to fescue toxins would allow for efficient use of fescue pastures; thus, the objectives of this thesis was to: …

Introducing The Academic Discipline Of Agricultural Communications To The United Kingdom: A Needs Analysis, Sara Kathryn Maples

Graduate Theses and Dissertations

There is a current need to identify and describe opinions of prospective employers and current agricultural students about the prospects of developing an agricultural communications academic discipline in the U.K. An understanding of the competencies employers would expect of agricultural communications graduates, as well as an understanding of what students would expect to learn, would form the conceptualization and development of the discipline in the U.K. A total of 22 agricultural communications professionals and 67 agricultural students from across the United Kingdom completed the survey. Collected data showed agricultural students and agricultural communications professionals answers overall were not statistically different. …

Effects Of Serving Temperature On Sensory Perception And Acceptance Of Brewed Coffee, Matthew James Chapko

Graduate Theses and Dissertations

Coffee continues to be one of the most widely consumed beverages worldwide. How an individual perceives a cup of coffee is impacted by a plethora of factors including origin, growing climate, roasting level, and consumption habits. This thesis utilized both trained descriptive panelists and untrained consumer panelists to analyze how serving/consumption temperature modulates sensory perception of brewed coffee in regards to appearance, aroma, flavor, taste, and mouthfeel. Three varieties of coffee (Colombia, Ethiopia, and Kenya) were brewed and served to panelists at four temperatures: 70, 55, 40, and 25 °C. In one study (Study 1, Chapter 3), results from descriptive …

Influences Of Intrinsic And Extrinsic Hand-Feel Touch Cues On Sensory Perception And Emotional Responses Toward Beverage Products, Ragita Cantika Pramudya

Graduate Theses and Dissertations

Consumer perception of and preference toward products are influenced by intrinsic product-specific (e.g., product temperature) and extrinsic non-product-specific (e.g., packaging or container) characteristics. Besides communicating information between products and consumers to create expectations toward the content at the point of sale, packaging also influences sensory perception of the content during consumption. Previous cross-modal studies on packaging effects on the content had largely overlooked hand-feel touch cues. Touch closely relates to consumers’ emotional responses to and their quality evaluation of products. One way to manipulate hand-feel touch cues in a beverage consumption setting is to vary materials of cup sleeve, which …

Methane Emissions From Rice Production On A Silt-Loam Soil In Arkansas, Joshua Jeffry Humphreys

Graduate Theses and Dissertations

Methane (CH4) emissions from rice (Oryza sativa L.) production are a source of concern in the environmental and agricultural communities. New and/or revised agronomic methodologies will be needed to identify production practice combinations that reduce CH4 emissions without decreasing yields. The objective of this multi-year study was to evaluate the effects of water management (i.e., full-season flood and mid-season drain) (2015), cultivar (i.e., pure-line cultivar ‘LaKast’ and the RiceTec hybrid “XP753”) (2015), soil organic matter (SOM) concentration (2016), and tillage [conventional tillage (CT) and no-tillage (NT)] and urea-based fertilizers [N-(n-butyl) thiophosphoric triamide (NBPT)-coated urea and non-coated urea] (2017) on CH4 …

Body Composition, Muscular Performance, And Free Testosterone Following 12-Weeks Of Protein Supplementation And Resistance Training In Men Aged 35-55, Matthew Steven Stone

Graduate Theses and Dissertations

PURPOSE: The purpose of this study was to investigate the effects of 12 weeks of protein supplementation and Autoregulatory Progressive Resistance Exercise (APRE) training on measures of body composition, muscular performance, and free testosterone in middle-aged men. METHODS: Untrained males (n = 35; 43.3 ± 6.6 years) participated in this study. Lean mass (LM) and fat mass (FM) were measured via Dual Energy X-ray Absorptiometry (DEXA), while strength was measured utilizing one repetition maximum (1RM), endurance measured using maximum repetitions completed (REPS) at 75% 1RM for the bench and leg press, and free testosterone was measured using changes in serum …

Assessment Of A Nutritional Rehabilitation Model In Two Modern Broilers And Their Jungle Fowl Ancestor: A Model For Better Understanding Childhood Undernutrition, Mikayla Baxter

Graduate Theses and Dissertations

The World Health Organization, estimated that 22.9% of children under the age of 5 are stunted. The etiology of stunting is multifactorial and is associated with poor linear growth, villous atrophy, dysbiosis, and increased intestinal permeability. Inclusion of rye in poultry diets induces nutrient deficiencies and increases intestinal permeability, dysbiosis and decreases growth rates. The objective of this dissertation was to determine if chickens consuming a rye based diet exhibited a similar pathophysiology of stunted children to develop a relevant animal model. Therefore, early or late phase malnutrition was induced determine the effects of malnutrition on performance, bone mineralization, intestinal …

The Relationship Between Mental Health And Ultra-Running: A Case Study, Joshua Justin Cook

Graduate Theses and Dissertations

This instrumental case study sought to explore the relationship between ultra-running and mental health through the lived experiences of a single participant who self-identifies as an ultra-runner. Three research questions were used to explore this relationship; how did the individual decide to participate in ultra-running, what aspects of ultra-running impact the participant’s mental health, and how has engaging in ultra-running impacted the participant’s mental health? The case study utilized three semi-structured interviews, two participant observations, video documentary review, and journaling to answer these questions. A thematic analysis of the data revealed four essential themes; 1) Development of participation, 2) Promotes …

Can Social Capital Boost Irrigation Capital: Empirical Evidence From North China, Yefan Nian

Graduate Theses and Dissertations

Using data from China Water Institution and Management (CWIM) survey, the study first constructs measures of all three most studied dimensions of social capital: trust, networks, and norms. The study then examines if social capital has any predictive powers of individual farmers’ contribution decisions as well as farmers’ contributions aggregated at the village level. Farmers’ choices between different forms of contributions (labor versus cash) are also analyzed. Our results suggest that all three dimensions of social capital explain farmers’ contribution decisions. Governance quality of local irrigation systems and the norm of cooperation have strong predictive powers of farmers’ decisions to …

Factors Driving Sugar Cane Production In The Kingdom Of Eswatini, Brooke Danielle Anderson

Graduate Theses and Dissertations

Sugar cane is the largest industry in Eswatini with 16 percent of the total workforce working directly or indirectly in the sugar industry. Like all agricultural industries the sugar industry in Eswatini is heavily dependent on an abundant labor supply and climatic conditions. Labor efficiency and abundance is a defining factor of food security and profitability in Eswatini, having one of the highest national HIV/AIDS rates in the world. Small-scale sugar cane producers are often the hardest hit by HIV/AIDS as they traditionally rely on family labor more than hired labor. The 2016 Eswatini Vulnerability Assessment Report indicated that over …

Socioeconomic Impacts Of Infrastructure Investment In Eswatini: The Case Of Lusip, Noussayma Njeim

Graduate Theses and Dissertations

The 2016 Eswatini Vulnerability Assessment Report indicated that over half of the Eswatini population required livelihood support due to the severe El Niño drought. Since agriculture is the backbone of Eswatini’s economy, investments in climate change mitigation are needed in order to help protect the agriculture sector and associated livelihoods from increased yield and profit variability associated with future droughts. The IPCC (Intergovernmental Panel on Climate Change) estimates climate change in Eswatini could reduce rain-fed agricultural yields by up to 50%, threating the ability of Eswatini to be food secure. As such, investing in water capture systems could help mitigate …

Identification And Characterization Of Salinity Tolerance Genes By Activation Tagging In Arabidopsis, Jawaher Alkahtani

Graduate Theses and Dissertations

Salinity often affects irrigated areas in arid and semi-arid regions of the world. The existence and accumulation of soluble salts in the soil layers limit the growth of crops essential for our food. Salt stress dramatically affects plant growth, plant development, as well as crop yield. Arabidopsis thaliana is the plant model that provides a comprehensive knowledge of plant development, genetics and physiology, and response to abiotic stresses such as salinity. The redundancy of genes due to duplication, even in the simple model genome of Arabidopsis, limits the value of knockout (KO) mutagenesis to provide complete information on gene function. …

Characterization Of A Variant Of Tuberous Sclerosis Complex 2 And Its Interaction With Rheb, Sowmya Sivakumar

Graduate Theses and Dissertations

Protein-protein interactions are vital in maintaining proper function and homeostasis in cells. Some signaling pathways are regulated by G-proteins that work like switches to activate and deactivate pathways. Mutations in these proteins, their effectors or the interaction between proteins may cause dysregulation of signals that can lead to many diseases.

Rheb, Ras homology enriched in brain, is a Ras family GTPase that is vital in regulation of the mTOR (mammalian target of rapamycin) pathway that signals cell proliferation and growth. Due to the low intrinsic GTPase activity of Rheb, a GTPase activating protein (GAP), Tuberous Sclerosis Complex 2 (TSC2) down …

Association Mapping And Genomic Selection For Yield And Agronomic Traits In Soft Winter Wheat, Dennis Bulusan Lozada

Graduate Theses and Dissertations

Tools such as genome-wide association study (GWAS) and genomic selection (GS) have expedited the development of crops with improved genetic potential. While GWAS aims to identify significant markers associated with a trait of interest, the goal of GS is to utilize all marker effects to predict the performance of new breeding lines prior to testing. A GWAS for grain yield (GY), yield components, and agronomic traits was conducted using a diverse panel of 239 soft winter wheat (SWW) lines evaluated in eight site-years in Arkansas and Oklahoma. Broad sense heritability of GY (H2=0.48) was moderate compared to other traits including …

Dehydration, Muscle Damage, And Exercise In The Heat: Impacts On Renal Stress, Thermoregulation, And Muscular Damage Recovery, Cory L. Butts

Graduate Theses and Dissertations

Purpose: The purpose was to identify the combined influence of dehydration, muscle damage, and exertional hyperthermia on biological markers of acute kidney injury and renal function. We also investigated the effects of performing muscle damaging exercise during mild hypohydration on muscle damage biomarkers and muscular strength recovery. Methods: Eighteen recreationally-active males (age 24 ± 5 y, body fat 17.3 ± 6.2%) completed a familiarization visit and two experimental trials separated by ≥28 days. The two experimental conditions consisted of either euhydration (EU; maintaining hydration, -1.2 ± 0.8%) or hypohydration (HY; restricting fluid consumption for 24 hours prior to and during …

Evaluation Of Acetochlor And Other Very-Long-Chain Fatty Acid-Inhibiting Herbicides In Arkansas Rice, Michael E. Fogleman

Graduate Theses and Dissertations

The prevalence of herbicide resistance and lack of effective management options for controlling problematic weeds such as barnyardgrass and weedy rice in Arkansas rice production has led to exploration of alternative herbicide sites of action (SOA). Very-long-chain fatty acid (VLCFA)-inhibiting herbicides are not currently labeled for use in U.S. rice production but have been used with success in other row crops and in rice production in Asia. Based on preliminary research, rice tolerance and weed control were evaluated following various application timings and rates of acetochlor and pethoxamid, in addition to several other VLCFA-inhibiting herbicides. Rice tolerance to acetochlor was …

Comparative Microbial Community Dynamics In A Karst Aquifer System And Proximal Surface Stream In Northwest Arkansas, Josue Rodriguez

Graduate Theses and Dissertations

Northwest Arkansas has well-developed karst systems, with numerous sinking streams and springs. Karst conduits make it easy for contaminants to enter groundwater systems, degrading the water quality and destroying fragile karst ecosystems. With the increase of urbanization, potential threats in the form of fecal contamination may prove to be more of a problem. The purpose of this research is to compare the difference between microbial communities within two different settings, a karst aquifer and a surface stream. The microbial communities within Blowing Spring Cave and Little Sugar Creek were detected and identified in water and sediment samples. Samples were also …

Anti-Inflammatory Effect Of Berry Essences, Inah Gu

Graduate Theses and Dissertations

Inflammation is one of defense reactions of our body tissues against harmful stimuli such as infection and tissue injury. However, it has been reported that chronic inflammation can lead to chronic inflammatory diseases including diabetes, cardiovascular diseases and cancer. This transition from acute to chronic inflammation state is usually induced by pro-inflammatory mediators and cytokines including nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), which accelerate the development of other chronic diseases. Accordingly, targeting these pro-inflammatory factors is one of the important roles for anti-inflammatory agents. For last two decades, researches about anti-inflammatory …

Effect Of Allelic Variation In Rht Loci On Plant Height And Grain Yield Of Soft Red Winter Wheat (Triticum Aestivum L.), Habib Hayat

Graduate Theses and Dissertations

Plant height in wheat (Triticum aestivum L.) is controlled in large part by two major Rht genes, Rht-B1 and Rht-D1, which pleiotropically impact lodging and grain yield. Prior to the Green Revolution, wheat varieties contained only ‘wild-type’ Rht alleles (Rht-B1a and Rht-D1a) and were tall and prone to lodging. Introgression of a semi-dominant mutation at either of these two loci (Rht-B1b or Rht-D1b) results in a semi-dwarf phenotype and reduced plant height. When combined (Rht-B1b and Rht-D1b) an extremely short double-dwarf phenotype is observed. The objective of this study was to determine the impact of allelic variation in Rht-B1 and …

Genomic Approaches To Identify Important Traits In Avian Species, Bhuwan Khatri

Graduate Theses and Dissertations

This dissertation focusses on identifying different molecular markers that have impact on overall poultry production. Chapter one reviews microRNA (miRNA), copy number variation (CNV) and single nucleotide polymorphism (SNP) as markers suggested in different avian species by various studies. It reviews modern genomic approaches that are employed for next generation sequencing data analysis and verification.

Chapter two seeks to identify and validate the muscle specific miRNAs in the breast muscle of modern broilers and its foundational chicken line. Small RNA sequencing was performed to identify differentially expressed mature miRNAs in the breast muscles of these two chicken lines. Results showed …

Bioavailability Of Bioactive Compounds, Wing Shun Lam

Graduate Theses and Dissertations

Arachidin-1 (Ara-1) and arachidin-3 (Ara-3) are stilbenoids found in hairy peanut roots, which have been shown to possess similar, if not higher, efficacy in biological activities when compared to nonprenylated analogs such as piceatannol and resveratrol. Blackberry essences are concentrated volatiles, which are characterized by low molecular weight, lipophilic properties, and have also been demonstrated to have health benefits. As interest in dietary bioactive compounds functional ingredients increase, more emphasis has been placed on identifying which compounds have high efficacy as well as bioavailability. The ability of a compound to exert its health promoting effects depends on its bioavailable dose, …

Dissection Of Soil Waterlogging Tolerance In Soft Red Winter Wheat Using Genomic Approaches, Marlovi Andrea Acuna-Galindo

Graduate Theses and Dissertations

Genomic methods including genome wide association analysis (GWAS), genomic selection (GS) and RNA-seq allow for faster selection of superior breeding lines and for identification and resolution of candidate genes. A panel of 240 soft red winter wheat (Triticum aestivum L.) cultivars and breeding lines were subjected to soil waterlogging stress over two seasons at Stuttgart, AR and St. Joseph, LA, US. Total concentrations of P, K, Ca, Mg, Mn, Fe, Al, B, Cu, Na, S and Zn were determined in wheat shoots post-waterlogging using inductively coupled plasma spectroscopy. Yield components kernel number per spike (KNPS), kernel weight per spike (KWS) …

Effect Of Yeast Supplementation During Various Stages Of Beef Production, Elizabeth Palmer

Graduate Theses and Dissertations

Supplemental dietary yeast products are beneficial during times of stress. Calves experience increased levels of stress during birth, weaning, and the post-weaning receiving period. Therefore, 3 experiments were conducted to determine how yeast supplementation affects growth performance and health during this time. In experiment 1, 2 truckloads of highly stressed calves (n = 175; initial body weight [BW] = 226 ± 24.5 kg) were assigned randomly to 1 of 3 treatments; unsupplemented control, or supplementation with 2 commercial yeast products (Y1 and Y2). Average daily gain (ADG) was not different (P = 0.99) during the 28 d receiving period; nor …