Social and Behavioral Sciences Commons^™

The Feedback-Related Negativity Is A Time-Dependent Brain Mechanism That Facilitates Aversive Learning: Implications For The Reinforcement Learning Frn Hypothesis, Eric Rawls

Graduate Theses and Dissertations

Organisms encode rewarding and aversive experiences through reinforcement learning, capitalizing on prediction errors (PEs), which adapt action strategies over time. Computational theories are explicit that PE signals should update action weights continuously over the course of a behavioral task, an important time-dependent variation that is eschewed in traditional neuroscience studies that average over large numbers of trials. I examined variation in reaction times and feedback-locked cortical activity over time as a function of PE to critically examine theories indicating that PE signals drive time-dependent learning. We recorded EEG while participants completed a novel reinforcement task that varied prediction error on …

Coccidiosis Vaccination And Nutrient Utilization In Broiler Chickens, Alyson Elaine Gautier

Graduate Theses and Dissertations

Four experiments were conducted to evaluate the interrelationships among coccidiosis vaccination and nutrient utilization in floor-reared broiler chickens. Experiment 1 longitudinally compared the effects of coccidiosis vaccination and a chemical coccidiostat on broiler performance, nutrient digestibility, and intestinal morphology. Coccidiosis vaccination had no significant impact on morphology, overall body weight gain and feed intake of vaccinated birds, although vaccination impaired overall FCR. Vaccination elicited a transient reduction in digestibility of energy and nutrients, particularly for lipids, but vaccinated birds were able to recover from these reductions by 20 d. Experiment 2 assessed the impact of vaccination in digestibility of different …

Strategies To Improve Forage Utilization By Sheep Offered Forage Mixtures, Valens Niyigena

Graduate Theses and Dissertations

In the first experiment, alfalfa and novel endophyte-infected tall fescue (NE+) forages were harvested after a killing frost, then mixed to formulate 4 different treatments; alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. After 3 months of storage as silage, Dorper ewe lambs (n = 20; mean BW = 34.7 ± 6.65 kg) were fed silage for ad libitum consumption, using 5 animals per treatment. Increasing the proportion of NE+ tall fescue improved (P < 0.05) silage total acids and lactic acid concentrations and decreased silage ammonia concentration. Digestible dry matter and organic matter intake and nitrogen utilization parameters decreased with increasing inclusion of NE+ in diet. In the second experiment, 16 Dorper ewe lambs (41.8 ± 4.61 kg BW) were assigned to 4 different treatments; alfalfa silage alone (0 g/kg; CONT) or alfalfa silage mixed with chopped sericea lespedeza (SL) hay to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) on a dry matter basis in a randomized complete block design experiment with 2 period to provide 4 observations per treatment for each experimental period. Increasing the proportion of sericea lespedeza in the diet decreased dry matter and organic matter digestibility but did not affect feed intake. Fecal nitrogen (g/kg N intake) increased linearly (P < 0.01) while urinary N (g/ day and g/ kg of N intake) tended to decreased linearly and quadratically (P ≤ 0.1) with increasing the proportion of SL in diet. In the third experiments, 16 gestating Dorper ewe lambs (49.1 ± 4.61 kg BW) were allocated to 4 treatments; alfalfa silage alone (0% g/kg; CONT) or alfalfa silage mixed with lablab purpureus(LP) hay to provide 90 (LOW), 180 (MED), or 270 g/kg LP (HIGH) on a dry matter (DM) basis, in a randomized complete block design experiment with a total 8 replication per treatment. Supplementation of LP in diet increased quadratically (P ≤ 0.04) forage dry matter, organic matter intake, digestible dry matter and digestible organic matter intake (P < 0.05). Nitrogen apparently absorbed and urinary N both decreased linearly (P < 0.01) with adding more LP hay in diet. Harvesting and mixing alfalfa and fescue after a killing frost improved silage fermentation characteristics and supplementation of tannins from SL and polyphenol from LP altered N excretion.

Key words: lablab, sericea lespedeza, alfalfa silage, nitrogen, sheep.

Establishing An Ideal Inclusion Rate Of Fermented Soybean Meal And Sodium Butyrate On Growth Performance, Complete Blood Cell Count, And Nutrient Utilization In Nursery Pigs, Kristopher A. Bottoms

Graduate Theses and Dissertations

To evaluate increasing levels of sodium butyrate (SB) in nursery diets on growth performance (Experiment 1 & 2), complete blood cell count (Experiment 2), and the optimal level of fermented soybean meal for maximum performance in weanling pigs (Experiment 3), weaned pigs were blocked with initial body weight (BW) and allotted to dietary treatments. Treatments were: 1) Control (C) moderately complex corn-soybean-meal based supplemented with 0.05% benzoic acid (BA), but devoid of SB; C diet supplemented with 0.05%, 0.10%, or 0.15% SB (Experiment 1). Treatments in experiment 2 consisted of 1) a moderately complex corn-soybean-meal based diet devoid of SB …

Methods To Evaluate Ruminant Animal Production Responses, Jose Manuel Diaz Gomez

Graduate Theses and Dissertations

In experiment 1, 80 steers (197.0 kg initial body weight; BW for fall, 116.9 kg for spring), were stocked at 2.45 and 4.1 calves/ha in fall and spring, respectively in 16 tall fescue pastures [fall ergovaline (EV) = 1,475 ppb and spring EV = 1,173 ppb] under 2 treatments, mineral (MIN) (n = 8) and cumulative management (CM) (n = 8). Forage allowance did not differ (P = 0.76) between CM and MIN during fall but differed during spring (P ≤ 0.05, 2.55 vs. 3.22 kg DM/kg BW, for MIN and CM, respectively). For fall, average daily gain (ADG) resulted …

Effects Of Dietary Copper, Zinc And Manganese Source And Level On The Acute Inflammatory Response Of Broilers, Chelsea Ellington

Graduate Theses and Dissertations

Trace minerals, particularly copper, zinc and manganese, play a role in ensuring optimal immune function. To examine the effects of diets containing different levels and sources of trace minerals on the inflammatory response, Cobb 500 broilers were fed four experimental diets containing 5 mg/kg Cu and 45 mg/kg of Zn and Mn or 10 mg/kg Cu and 90 mg/kg Zn and Mn in either the sulfate or hydroxychloride form. When the broilers were 5 weeks of age, 16 μg of lipopolysaccharide (LPS) was injected into the pulp of growing feathers (GF; 16 GF per chicken; 1 μg LPS per GF). …

Investigating Egg Storage Conditions, Hatch Characteristics, And Feeding Methods Of Commercially Produced Poultry, Joshua R. Deines

Graduate Theses and Dissertations

Advancements in poultry research continue to add knowledge and understanding to an already technical industry. Such information has led to new developments in early feeding strategies which provide nutrients to broiler chicks while in the egg or during transport. This wealth of knowledge in poultry research extends beyond chickens and is utilized for other species, such as quail and pheasants, including how fertile eggs are stored and incubated. However, methods of early feeding broilers have not been investigated in industry relevant approaches to understand its effects, including how timing of feed access interacts with the hatch window. As well, quail …

The Effects Of Foot And Udder Scoring On Cow And Calf Performance, Clayton Lee Mcguire

Graduate Theses and Dissertations

Foot soundness and udder conformation are essential for longevity in beef cattle. The objective of this study was to investigate the effects of foot angle (FA), claw set (CS), teat size (TS) and udder suspension (US) scores on cowherd performance. Data were analyzed for 1,685 observations on Angus-based cows over a four-year period. At weaning FA, CS, TS, and US were evaluated. Scores are based on nine-point scales. A score of one indicates straight pasterns, divergent toes, enlarged bottle shaped teats, and absence of a median suspensory ligament; nine indicates weak pasterns, curled toes, small symmetrical teats, and a tight …

Cost Effectiveness Of Greenhouse Gas Reductions Through Afforestation Of Agricultural Land In The Arkansas Delta, Karli A. Moore

Graduate Theses and Dissertations

Sequestration of atmospheric carbon in forested lands offsets carbon emissions from other industries. Conversion of private lands, particularly agricultural tracts in marginal areas, to forests can bolster carbon abatement. The United States government agencies administer some voluntary, incentive-based programs to encourage landowners to adopt production practices with positive environmental outcomes. This policy stream can be used to increase transition of marginal agricultural land to forests, thereby creating new carbon sinks. We analyze an eleven-county study area in the Arkansas Delta to determine feasibility for a subsidy focused on carbon abatement through afforestation. This study area is significant for two reasons: …

Serum Myostatin And Igf-1 As Biomarkers Of Sarcopenia: A Proof-Of-Concept Design, Ashley Binns

Graduate Theses and Dissertations

The population comprising older adults is growing exponentially, as are healthcare related costs. Nearly $20 billion is annually expensed by older adults for health-related issues affiliated with age-related decline in skeletal muscle mass. Yet, diagnostic criteria are not readily utilized in clinical practice. PURPOSE: Therefore, the purpose of this study was to provide evidence for use of blood biomarkers (myostatin, IGF-1) to predict appendicular skeletal muscle mass (ASM) among middle-aged and older adults. METHODS: A cross-sectional study was conducted among 106 individuals (n = 68 females; n = 38 males) aged ≥ 40 years of age (60.1 ± 11.1 y) …

Poultry Labeling: Knowledge, Perceptions, And Preferences Among Adolescents, Eleni L. Parsons

Graduate Theses and Dissertations

The purpose of this study was to determine the knowledge, perceptions, and preferences of adolescents in regard to the labeling of poultry products. The theory of planned behavior (TPB) and Elaboration Likelihood Model (ELM) were used to display the relationship of perceptions, attitude, and behavior intentions. Quantitative data was collected in a descriptive research design. The population included youth, aged 14 – 18 years, involved in the Arkansas 4-H State O’Rama competition (N = 400). The sample (n = 80) ensured a 90% confidence interval of the population. Data was collected by administering paper surveys that addressed four product labels …

Impacts Of Size Fractionation And Processing On Functional Characteristics Of Broken Rice Kernels, Rebecca Mawusi Bruce

Graduate Theses and Dissertations

Rice flour generated from broken rice (brokens) has inconsistencies in functional properties. This may be due to differences in size and composition of brokens used for the flour. It is postulated that size classification of brokens can improve flour functionality. This study sought to investigate the effect of size fractionation of brokens on the functional or pasting properties of resulting rice flour. Broken rice was generated from six cultivars of freshly harvested rough rice that were dried at 25◦C in the laboratory. The brokens were classified into large, medium and small, using US sieve size 10, 12 and 20 respectively. …

Impact Of Sanitizers On Salmonella Enterica Contamination And Microbial Populations Of Poultry Processing Reuse Water, Andrew Micciche

Graduate Theses and Dissertations

As human populations increase in numbers, access to clean, fresh water is becoming increasingly difficult to balance between agricultural and municipal demands. Water scarcity is a limiting factor of food production in many countries, whether they are emerging or established economies. In conventional poultry processing systems, access to water is particularly critical for the maintenance and disinfection of processing areas, as well as in processing operations such as scalding, chilling, and carcass washing. The need for sustainable alternatives to single-use water supplies is becoming increasingly more urgent, and as a result, the implementation of water reuse in poultry processing plants …

The Impact Of Bumpers College Of Agricultural, Food And Life Sciences International Programs On Student Motivation For Continuing College And Student Engagement In The Classroom, Olivia Caroline Caillouet

Graduate Theses and Dissertations

Colleges aim to increase student achievement, which has been linked to motivation and engagement, as well as increase global partnerships. There is also an increasing demand from students for international programs (IPs) that prepare them to be global citizens. This study aimed to compare student motivation for continuing college and student engagement in the classroom before and after an IP. Students who participated in a Bumpers College of Agricultural, Food, and Life Sciences IP between January 2018 and August 2018 were surveyed prior to, and two weeks and three months post-program participation (n = 24). The instrument had 51 Likert-scale …

Assessing The Economic Viability Of Arkansas Farms Under The 2018 Farm Bill, Grant Wilson

Graduate Theses and Dissertations

For over a century, the American agricultural industry has relied on federal government support to aid in the maintenance and expansion of farming operations. Since 1933, a series of 18 farm bills have shaped agricultural policy into what is commonly known as the agricultural safety net. The 2018 farm bill was passed on December 20, 2018 and is the most recent update of the agricultural safety net. Commodity programs and federal crop insurance are two key components of today’s agricultural safety net, and many times, these programs may be the difference between a net loss and a positive net income …

Effects Of Multivitamin-Mineral Supplementation On Mental Health Among Young Adults, Ya-Hsuan Chang

Graduate Theses and Dissertations

The percentage of young adults who had mental illnesses has increased from 2008 to 2015. However, few existing studies investigating the potential benefits of multivitamin-mineral (MVM) supplementation on mental health focused on young adults (18-24 years of age), whose eating behaviors are often unhealthy. The purpose of this study was to examine the effects of a MVM supplement on mental health in young adults. One hundred and thirty-three college students (Mage=20.59, SD=1.77; 80.15% female) participated in this randomized, double-blind, placebo-controlled trial. Participants consumed either a MVM supplement or a placebo for 30 days. The supplement contained B Vitamins, Vitamin C, …

Estimating Demand Elasticities For Rice In Benin, Ogoudele Simon Codjo

Graduate Theses and Dissertations

Rice consumption in Benin is increasing along with shifting consumer demand toward higher quality rice. In this context of changing demands, experimental estimation methods provide an effective way to estimate the current state of consumer preferences. We conducted a hypothetical choice experiment in 15 open markets in Benin to analyze the demand for rice and its substitutes. The results reveal that consumers value quality rice, even those in the low-income class. While high income consumers are more likely to choose high quality imported rice, low- and middle-income consumers are more likely to select high quality domestic rice among the set …

On The Path To A Resilient Urban Food System In A Rural State: A Mixed-Method Needs Assessment Of Urban Producers And County Extension Agents In Arkansas, Catherine Elizabeth Dobbins

Graduate Theses and Dissertations

This project utilized a mixed-method needs assessment approach to urban agriculture in Arkansas, a predominately-rural state. Chapter II was a qualitative study, using semi-structured, in-depth interviews, that investigated the perceptions, needs, and experiences of Arkansas urban farmers and their interactions with the University of Arkansas Division of Agriculture Cooperative Extension Service (CES). Interviews were conducted with 16 urban farmers in Northwest and Central Arkansas. The interview data revealed individualized needs based on the size, years in operation, and mission of each urban farmer interviewed. General needs were determined, such as market pricing, co-ops, and access to appropriate equipment, but generally …

Producer Preferences For Alternative Irrigation Practices In The Arkansas Delta, Robert Edward Rosene

Graduate Theses and Dissertations

We use a bivariate sample selection model to address peer network effects on participation in and/or intensity of use of land being irrigated by alternative irrigation practices in the state of Arkansas. As groundwater in the state becomes more limited, the use of scientific scheduling, flowmeters, and more efficient row crop water application systems will allow producers to better manage water resources. We find relatively large, positive relationships between belonging to a peer network of the same irrigation practice and participation in that practice. Intensity of use of alternative irrigation techniques is mostly influenced by which crop type the practice …

Alcohol Use, Dietary, And Exercise Behaviors: A Latent Profile Analysis Of Young Adult Lifestyle Behaviors, Ryan Wesley Grant

Graduate Theses and Dissertations

As individuals enter adulthood, their lifestyles and lifestyle behaviors begin to change drastically. These lifestyle behavior changes in emerging adulthood provide a foundation for future health behaviors that often persist through all of adulthood. The aim of this study was to use Latent profile analyses (LPA) to discover distinct profiles of homogenous groups of young adults based on alcohol, diet, and exercise behaviors. Overall, five distinct profiles for both males and females were identified: Moderates, Unhealthy Eaters, Medium Drinkers, Healthier Eaters and Exercisers, and Heavy Drinkers. Heavy Drinkers and Unhealthy Eaters were the highest risk groups and reported the highest …

Analysis And Conservation Of Native Forests At Kessler Mountain Fayetteville, Arkansas, Alan James Edmondson

Graduate Theses and Dissertations

Kessler Mountain in Fayetteville Arkansas has long been recognized for its beauty and natural resources. Parts of Kessler Mountain have been homesteaded and developed in the past, but most of the mountain has remained relatively undisturbed. The planned development of over 4,000 housing units to cover Kessler Mountain stimulated controversy and consideration of other management alternatives. A twist of fate involving an economic recession, a dedicated group of outdoor recreation enthusiasts, and environmental conservationists led to the permanent protection of 384 acres in the Kessler Mountain Regional Park. To help evaluate the natural resources at Kessler Mountain, forest composition, structure, …

Reducing The Risk: Psychological And Technological Approaches For Improving Handwashing Practices In The Foodservice Industry, Jeffrey Allan Clark

Graduate Theses and Dissertations

As Americans are spending greater portions of their dollar on food consumed outside the home, the foodservice industry plays more of an integral part of daily existence compared to previous generations. Given the numerous annual foodborne illness outbreaks that threaten human lives while undermining confidence in the food supply, food safety is a pertinent issue for industry stakeholders, government regulators, and consumers. Food worker handwashing reduces the risk of foodborne illness transmission, yet compliance with this simple behavior is a complex problem. This dissertation addresses, predominantly, the issue of sub-optimal handwashing practices through applying psychology and technology, including wearable computers …

Hormone Signaling, Gene Expression, And Mitochondrial Hormone Receptor Expression In Avian Muscle (Cells), Kentu Rushadd Lassiter

Graduate Theses and Dissertations

Mitochondria are vital to the proper growth and function of muscle cells since they’re responsible for the majority of ATP production used for cellular energy. Previous studies have investigated how differences in mitochondrial function affects feed efficiency (FE) in broilers phenotyped for High and Low FE. Low FE broilers have been shown to have increased levels of reactive oxygen species (ROS), thus contributing to higher levels of oxidative stress and damage seen in these birds. Global gene and protein expression studies conducted on breast muscle of the High FE and Low FE phenotypes have suggested that differences in mitochondrial function …

A Phenomenological Study Of The Lived Experiences Of Counseling Students In A Co-Facilitated Experiential Group, Alexandra Meyers

Graduate Theses and Dissertations

Research in the fields of experiential learning, group psychotherapy, and neuroscience has supported the inclusion of the experiential group in counseling training programs due to the potential for positive impact on students’ personal and professional development (Badenoch & Cox, 2010; Denninger, 2010). Investigations exploring counseling students’ experiences of the experiential group have been primarily limited to quantitative studies, while in-depth qualitative inquiry has been minimal. Additionally, an extensive review of the literature has found there have been no qualitative studies examining experiential groups co-facilitated by a course instructor and a doctoral student. The purpose of this phenomenological study was to …

Evaluation Of Herd Size Management Strategies, Colson A. Tester

Graduate Theses and Dissertations

This thesis is comprised of two studies examining the effects of price signal based herd size management strategies on profitability of cow-calf operations. Herd size management strategies were evaluated across the previous two cattle cycles, 1990-2014, using a fixed land resource and included a variety of production scenarios. These scenarios varied in terms of stocking rates, fertilizer applications rates, and calving season. Each scenario was also analyzed both with and without weather effects on forage production. Weather effects were simulated using a production index derived from satellite imagery across the observed 25-year period. Three herd size management strategies: i) constant …

Interactions Between The Protein Industry And Blogs: An Analysis Of Content And Perceptions, Kylie Hackworth

Graduate Theses and Dissertations

This thesis contains two articles that describe and characterize the use of the social media platform of blogging in the context of the animal agriculture and protein industry. The first article used content analysis to analyze blog posts and look for themes throughout the posts. This study included 37 posts from ten authors and resulted in four recurrent themes. The major themes were environment, consumption of protein, alternative protein source, and alternative dieting. The tones regarding these themes were both negative and positive toward the protein industry.

The second article used hand-coding to look for themes and similarities concerning flow …

The Farmers’ Federation: Regional Racial Mythologies As Agricultural Capital, Jama Mcmurtery Grove

Graduate Theses and Dissertations

In 1927, the Farmers’ Federation agricultural cooperative in Western North Carolina launched an organization to solicit funds from wealthy donors. The money raised through philanthropic campaigns enabled the cooperative to fund large-scale agricultural projects, which helped members navigate the dramatic agricultural transformations of the early twentieth century. Although the cooperative advocated a progressive program of business-minded, scientific farming, its leadership modified programs to reflect farmer members’ limited resources and the realities of mountain production. As a result, the co-op provided a crucial bridge between white farmers and new methods of agricultural production that reached deep into peoples’ familial and productive …

Electrophysiological Correlates Of Visual Object Category Formation In A Prototype-Distortion Task, Stephanie Marie Long

Graduate Theses and Dissertations

In perceptual learning studies, participants engage in extensive training in the discrimination of visual stimuli in order to modulate perceptual performance. Much of the literature in perceptual learning has looked at the induction of the reorganization of low-level representations in V1. However, much remains to be understood about the mechanisms behind how the adult brain (an expert in visual object categorization) extracts high-level visual objects from the environment and categorically represents them in the cortical visual hierarchy. Here, I used event-related potentials (ERPs) to investigate the neural mechanisms involved in object representation formation during a hybrid visual search and prototype …

Optimization Of The Light Environment For Broiler Chickens, Douglas J. Aldridge

Graduate Theses and Dissertations

The use of artificial light sources has been necessitated by the use of fully enclosed rearing facilities for improved environmental control. Light Emitting Diodes (LED) have been developed as a light source that reduce the utilities required to provide equal light to that of incandescent sources. The following reports were carried out to investigate the effects of two light color temperatures, light intensity and light intensity gradients on broiler chicken production and behavior. The first investigation consisting of two consecutive trials investigated the effect of two light color temperatures (2700 K and 5000 K) in addition to the preference for …

Broiler Breeder Amino Acid Levels And Progeny Nutritional Status, Leasea Butler

Graduate Theses and Dissertations

Crude protein needs of chickens have changed due to genetic line differences and selection of those lines for differing broiler traits. Standard commercial broiler strains have been selected to be used to meet multiple processing categories typically at live body weights less than 3.5 kg. In the last two decades high-yielding broiler strains were introduced into the commercial market. These breeds are known as the Cobb 700 and Ross 708. The works included within are focused on the Cobb 700 high-yielding broiler strain, and its response to crude protein, with emphasis on digestible lysine.