Digital Commons Network^™

Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays

Graduate Theses and Dissertations

In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same …

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Graduate Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated …

Production Of Bioethanol By Fermentation Of Sugars Released By Dilute-Acid And Enzymatic Hydrolysis Of Soybean Meal, Deivis E. Lujan-Rhenals

Graduate Theses and Dissertations

Soybean meal (SBM) is a co-product of soybean oil extraction mostly used as animal feed due to its protein content ranging from 40 to 49%. Additionally, SBM contains 35-42% of carbohydrates, half of which are structural, and the remaining consists of approximately 17% of mono- and disaccharides--especially sucrose--up to 8% oligosaccharides, and 1-2% starch. When used as animal feed, only sucrose and starch are digested and absorbed by monogastric animals. Although SBM contributes carbohydrates to their diet, its main function is to provide proteins. Therefore, the selective removal of carbohydrates would create a protein-enriched meal with a greater value, which …

Studies On The Structure And Pathogens Of The Small Hive Beetle (Coleoptera: Nitidulidae), Natasha A. Wright

Graduate Theses and Dissertations

The small hive beetle (Aethina tumida, SHB) is an invasive pest of honey bee (Apis mellifera) colonies in the United States. The adult and larval beetles can ruin honey through fecal contamination and by vectoring a mutualistic yeast (Kodamaea ohmeri) that causes honey fermentation. These beetles also impact honey bee colonies by feeding on bee eggs, bee brood, and pollen. Severe beetle infestations can cause colonies to decline or abscond.

The SHB has been present in the United States since at least 1998. Since then, there have been several published papers on how to successfully rear these beetles. Laboratory rearing …

Measuring The Energy Required To Dry Rice In Commercial Rice Dryers, Maria Alejandra Billiris

Graduate Theses and Dissertations

The objective of this research was to quantify and assess the energy use and efficiency of commercial cross-flow dryers when drying rice using a range of drying and ambient conditions. First, equations that predict the theoretical energy required to dry rice from any given initial moisture content to a desired final moisture content were developed for several rice cultivars using a semi-theoretical approach to obtain a basis for comparison to calculate energy efficiency. Theoretical energy requirements, expressed as the energy required per unit mass of water removed, increased exponentially as initial moisture content decreased. Additionally, medium-grains required more energy to …

A Cradle To Farm Gate Life Cycle Analysis Of Water Use In U.S. Pork Production, Eric Boles

Graduate Theses and Dissertations

The intent of this study was to analyze water use across a range of regions, scales and practices of the U.S. pork industry. A Life Cycle Assessment of water use within the pork supply chain was performed. Cumulative water use was the environmental impact category used in the LCA to evaluate the impacts of pork production processes throughout the pork supply chain. The functional unit for the analysis was the volume of water required to produce one kilogram of swine (live weight) at the farm gate.

A comprehensive literature review was used to design and propagate algorithms for the National …

Life History Variation Of Common Terns In The Gulf Of Maine, Jeffery Bryant Kimmons

Graduate Theses and Dissertations

Life history is the inheritable rules that determine energy and time allocation towards different competing functions in the energy budget of an organism. Reproductive effort varies as organisms make reproductive decisions based on available energy. Factors influencing life histories are those that change energy and time budgets such as diet, competition, and environmental conditions.

Common tern (Sterna hirundo) life history phenotypes vary between islands in the Gulf of Maine. Common terns on offshore islands (>10km from mainland) and nearshore islands (5 to 10km from mainland) lay smaller clutches, hatching chicks with slower growth rates than common terns …

Effects Of Associated Subcortical Beetles On Oviposition Behavior And Early-Stage Survival Of Sirex Nigricornis F. (Hymenoptera: Siricidae), Ace J. Lynn-Miller

Graduate Theses and Dissertations

Sirex (Hymenoptera: Siricidae) woodwasps develop within xylem of host conifers. Sirex females drill through the bark, phloem and into xylem tissues where they deposit eggs along with a symbiotic Amylostereum fungus. The presence of Amylostereum is necessary for successful development of Sirex immatures as the larvae are unable to derive adequate nutrition from xylem in the absence of the fungus. The Eurasian woodwasp, Sirex noctilio F., was discovered in northeastern North America in 2004. Sirex noctilio has caused significant economic damage in Pinus radiata D. Don plantations of the southern hemisphere, but is of little economic significance in its native …

Preparedness To Implement Wellness Strategies: Perceptions Of School Counselors, Tena Burnett

Graduate Theses and Dissertations

The purpose of this study is to survey school counselors to determine their knowledge and perceived preparedness to implement wellness strategies in school counseling programs. Wellness plans are a requirement for thousands of public school districts in the United States. There are no established standards for the training of school counselors in the area of wellness. School counselors are in a unique position to positively impact students through the use of wellness programs and strategies. School counselors from a mid-south state (N = 156) completed an electronic survey to measure how they implement wellness strategies and their perceived preparedness in …

Population Dynamics In Predynastic Upper Egypt: Paleodemography Of Cemetery Hk43 At Hierakonpolis, Ernest King Batey Iii

Graduate Theses and Dissertations

The site of Hierakonpolis is considered to have played an important role in the development of the Egyptian state, which formed at end of the fourth millennium BC. Archaeological evidence suggests that, for the Middle and Late Predynastic periods (ca. 3900-3200 BC), Hierakonpolis may be characterized as having experienced the following: a growth in both settlement and population size, an increased reliance on cereal agriculture, development of craft specialization, and the presence of a Social hierarchy as interpreted from an observed increase in the differentiation of mortuary behavior. Historical data suggest that these Social and economic changes would have affected …

Characterization And Epidemiology Of Soybean Vein Necrosis Associated Virus, Jing Zhou

Graduate Theses and Dissertations

Soybean vein necrosis disease (SVND) is widespread in major soybean-producing areas in the U.S. The typical disease symptoms exhibit as vein clearing along the main vein, which turn into chlorosis or necrosis as season progresses. Double-stranded RNA isolation and shot gun cloning of symptomatic tissues revealed the presence of a new tospovirus, provisionally named as Soybean vein necrosis associated virus (SVNaV). The presence of the virus has been confirmed in 12 states: Arkansas, Illinois, Missouri, Kansas, Tennessee, Kentucky, Mississippi, Maryland, Delaware, Virginia and New York. Symptomatic samples collected from eight states (AR, IL, MO, MS, KS, TN, MD and DE), …

Aesthetic Qualities Of Websites And Their Effects On Public Perceptions Of Agricultural Issues And Organizations, Chase Tyler Hundley

Graduate Theses and Dissertations

This study sought to evaluate perceptions of agricultural issues and organizations based on how information is presented visually in websites. Researchers intended the results to be used to help the agricultural industry more effectively communicate information through better website design and increased persuasiveness. The study was conducted through the use of three focus group sessions as mapped out by Krueger (1998a, 1998b, 1998c) and Morgan (1998a, 1998b). The study used non-agriculture students purposively selected from a class in the University of Arkansas School of Human Environmental Sciences as participants in the study. The subject demographics closely resembled the primary demographics …

Evaluation Of The Recombination Efficiencies Of Flp Proteins, Linh Duy Nguyen

Graduate Theses and Dissertations

Site-specific recombination systems are powerful tools for genetic modification. They have been used to integrate a transgene into a pre-defined locus and to remove marker genes from a transgene locus. Two of the most widely used site-specific recombination systems in plants are the Cre/lox system from the bacteriophage P1 and the FLP/FRT system from the yeast Saccharomyces cerevisiae. The Cre/lox system is well-characterized and is the first choice in application of site-specific recombination system. However, some applications such as marker-free site-specific gene integration require the use of two recombination systems. In addition, the availability of alternative recombination systems can offer …

Response Of Broiler Chickens To Variation In Dietary Nutrient Content, Sarah Diane Goodgame

Graduate Theses and Dissertations

Rising feed costs, environmental pollution concerns targeted at animal agriculture, a worldwide focus on sustainability and the never ending battle to improve production and efficiency within the poultry industry challenges nutritionists to focus on products to improve nutrient digestibility and decrease feed costs while at the same time maximizing performance. The research presented in this dissertation focuses on improving nutrient utilization of protein sources with protein liberating enzymes currently available commercially. The research also conducted addresses the addition of crystalline amino acids valine and isoleucine and their effect on improving efficiency of broilers.

The first research project compared the efficacy …

Community Structure And Ecological Specialization In Plant-Ant Interactions, Paola Barriga

Graduate Theses and Dissertations

Positive associations among species have contributed to the maintenance of biodiversity. These interactions are typically studied in pairwise fashion where two interacting organisms are the focus. This dissertation uses network theory to analyze positive plant-ant associations in three Neotropical forests. Obligate plant-ant mutualisms were used, where plants host the ants in domatia and provide food bodies while the ants protect the plants and can feed them. A network approach was used to depict all obligate plant-ant interactions within a community. The main questions asked at the community level were: 1) Do network structure and levels of specialization change geographically and, …

Breeding For Modified Seed Composition In Soybean: Selection Of Genotypes, Yield Stability, And Environmental Effects, Luciano Miguel Jaureguy

Graduate Theses and Dissertations

The development of cultivars with modified seed composition represents an excellent alternative to cope with the world's need for more nutritious food. Understanding the genetic and environmental factors controlling crop seed quality traits is of crucial importance for such an endeavor. The objectives of this study were: a) to evaluate the efficiency of phenotype and marker-assisted selection for low stachyose and low phytate soybean breeding lines, and their yield stability, b) to study the effect of management practices planting date and delayed harvest on soybean seed composition, and c) to study the potential association between soil properties and leaf chemical …

Effects Of Felled Shortleaf Pine (Pinus Echinata Mill.) Moisture Loss On Oviposition Preferences And Survival Of Sirex Nigricornis F. (Hymenoptera: Siricidae), Jessica Hartshorn

Graduate Theses and Dissertations

The European woodwasp, Sirex noctilio F. (Hymenoptera: Siricidae) utilizes pine as its host during larval development. Females drill through pine bark to deposit eggs, a symbiotic fungus, Amylostereum, and phytotoxic mucus into the tree. In their native range, these insects are not viewed as primary pests because they attack dead or dying trees. Over the last century, this woodwasp has been accidentally introduced into several countries in the southern hemisphere. Some regions have incurred millions of dollars in damage to large plantations of the widely planted pine species, radiata pine (Pinus radiata D. Don). Sirex noctilio was discovered …

Influence Of Nutritional Modifications On Sow, Litter, And Nursery Performance, Benjamin Edward Bass

Graduate Theses and Dissertations

Two separate series of experiments were conducted to determine: 1) the influence of dietary arginine supplementation in late gestation on reproductive performance, and 2) the impact of a whole yeast product in gestation, lactation, and weaned pig diets on reproductive, growth, and immune parameters.

In the first study 99 sows were provided a control diet, or the control diet supplemented with 1% L-arginine from gestation d 93 to 110. Compared to control-fed sows, no differences were observed in reproductive parameters, however a tendency for increased gestational weight gain was observed for sows provided supplemental arginine.

In a second study, 98 …

Predictability Of Food And Wine Pairing Using A Sensory Approach, Rebeckah L. Koone

Graduate Theses and Dissertations

The purpose of this study was to explore significant differences in perception of match for a variety of food and wine styles; evaluate the impacts of wine sweetness level, wine acidity level, and wine tannin level on perception of match; and to investigate the impact of food and wine expertise on perceived level of match. A field research design was used to explore expert recommendations of food and wine combinations to obtain broader feedback on consumer perceptions. The population consisted of a convenience sample of 248 students enrolled in a continuing education course in food and wine pairing at George …

The Impact Of Bovine Spongiform Encephalopathy (Bse) On World Protein Supply, Jarrod Kersey

Graduate Theses and Dissertations

As world population, per capita income and urbanization increase, consumption of meat, poultry, milk and eggs will continue to rise to meet the needs of approximately nine billion people in 2050. Global beef, pig and chicken production and per capita consumption increased between 2000 and 2010, with growth in broiler production and consumption outpacing both beef and swine. The increased production and consumption requires readily available feed ingredients in regions where animal production is rapidly developing. Animal-based protein feed ingredients are often difficult to move from country to country due to real or perceived risk of animal disease. Zoosanitary standards …

Effects Of Meloidogyne Incognita, Soil Physical Parameters, And Thielaviopsis Basicola On Cotton Root Architecture And Plant Growth, Jianbing Ma

Graduate Theses and Dissertations

The root-knot nematode, Meloidogyne incognita, and the seedling pathogen, Thielaviopsis basicola, commonly co-exist in Arkansas cotton fields and may interact resulting in increased losses. The primary objective of this research was to evaluate the effects of soil physical parameters on these soilborne pathogens and cotton growth in controlled environmental, field, and microplot studies. Controlled environmental experiments used two soil bulk densities and four pathogen treatments: non-infested soil, soil infested with M. incognita or T. basicola and soil infested with both pathogens. The results indicated bulk density generally did not affect seedling growth or disease since soils had low penetration resistance …

Genetic Diversity, Pathogenicity/Virulence Variation And Population Structure Of Rhizoctonia Spp. Associated With Rice Sheath Blight In Arkansas And Qtl Mapping For Disease Resistance, Vanina Lilian Castroagudin

Graduate Theses and Dissertations

Rice sheath blight (ShB) is one of the most prevalent diseases in rice. The significance of this disease is increasing due to more intensive production practices globally. Rhizoctonia solani Kühn AG 1 - IA [teleomorph: Thanatephorus cucumeris (A.B. Frank) Donk] is considered the primary ShB pathogen of rice. However, Rhizoctonia oryzae-sativae, Rhizoctonia oryzae, and R. solani AG 2 and AG 11, have also been isolated from sheath blight-like lesions on rice.Up to now, there is little information on genetic diversity and patterns of molecular evolution of the fungus, and there is no study on the structure of the R. solani …

What Factors Influence Consumers' Willingness To Purchase And Consume Carbon-Labeled Rice: A Comparative Study Between Arkansas And Belgium, John A. Kelley

Graduate Theses and Dissertations

Climate change is an issue of growing importance around the globe. As global population increases so does attention focused on human contributions to climate change. One major way humans contribute to climate change is through our diets. Agricultural production is a major source of global greenhouse emissions. It has been estimated that food production is responsible for a large majority of the methane and nitrous oxide which is emitted into our atmosphere each year. Carbon footprint labeling has been developed to give consumers a way to lower their footprint and help lower emissions of greenhouse gasses. At least one retailer, …

Economic Implications Of Extreme Heat Effects On Rice Yield And Milling Quality In Arkansas, Nate Lyman

Graduate Theses and Dissertations

Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of extreme heat effects on rice production have focused on paddy yield and have not accounted for the detrimental impact of extreme heat on milling quality outcomes which ultimately determine edible (marketable) rice yield and value. Using rice yield and milling quality data on six popular rice cultivars from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, this study finds a nonlinear effect of extreme heat exposure on yield and milling quality. A 1 °C increase …

The Identification Of Quantitative Trait Loci For Sucrose And Stachyose Content In Soybean Seed, Ailan Zeng

Graduate Theses and Dissertations

Sucrose is a desirable sugar in soybean seed that affects the quality and taste of soyfoods, while stachyose is a non-digestible sugar that induces flatulence in non-ruminant animals. Therefore, soybean cultivars with high sucrose and/or low stachyose would be valuable for soyfood and meal markets. The objectives of this study were to identify quantitative trait loci (QTL) or genes associated with seed sucrose and stachyose content using simple sequence repeat (SSR) or single nucleotide polymorphism (SNP) markers. A low sucrose line, MFS-553, was crossed with a high sucrose plant introduction, PI 243545, to develop the sucrose QTL mapping population. A …

Relationship Of Polymorphisms In The Fsh Beta Subunit Gene With Reproduction In Bos Taurus And Bos Indicus Cattle, Amanda Jo Davis

Graduate Theses and Dissertations

Two experiments were conducted to characterize polymorphisms (SNP) in the bovine FSHβ gene promoter region to examine breed differences in SNP, and to determine effects of SNP on reproduction in beef cattle. Experiment 1 - DNA samples were collected from 5 Angus (ANG), 13 Balancer (BAL), & 16 Brahman influenced (BI) bulls. Polymorphisms were identified by sequencing of 3 sequential PCR products from the promoter region revealed 17 SNP & 4 insertion/deletions (INDEL). Semen samples were collected and sperm quality variables determined via computer assisted sperm analysis (CASA) or stained smears. The MIXED procedure for ANG & BAL indicated interactions …

Lactic Acid Production Using Sweet Potato Processing Waste, Irene Pagana

Graduate Theses and Dissertations

Organic waste generated from industrial sweet potato canning is estimated to be 30% of incoming raw material. This waste contains carbohydrates (sugars and starch) that could be used as substrates for the production of useful compounds via fermentation (e.g. lactic acid), resulting in the production of value-added products. The goal of this research project is to produce a substrate from the sweet potato processing waste material that supports the growth of lactic acid bacteria, which results in the production of lactic acid. The sweet potato waste product was characterized, and found to contain 16.5% solids. The solids components were 18.5% …

The Competitive Front-Of-Package Labeling Of Consumer Packaged Goods: Cutting Through The Clutter, Christopher Newman

Graduate Theses and Dissertations

At no point in U.S. history have food product packages displayed so many symbols and statements regarding nutrition and health benefits (Nestle 2010). However, despite this explosion of front-of-package (FOP) health communications, obesity and health-related problems of U.S. consumers continue to be a critical concern. Therefore, it is important for marketers, retailers, manufacturers, and public policy makers to develop a more complete understanding of consumers' processing and utilization of health information on food packages, as well as how this information affects product evaluations and choices.

Therefore, this dissertation utilizes a processing fluency theoretical framework (e.g., Zajonc 1968; Jacoby and Dallas …

Interactions Between The Thermic Effect Of Food And Exercise On Total Energy Expenditure In Moderately Active Females, Ashley Binns

Graduate Theses and Dissertations

Diet and exercise are key components to overall health maintenance. Aspects contributing to weight maintenance include the thermic effect of food (TEF) and total energy expenditure (TEE), with TEF contributing to upwards of 10% TEE. PURPOSE: The purpose of this study was to determine the interaction between TEF and exercise on TEE in moderately active females. METHODS: A sample population was established with the use of a health history questionnaire (HHQ). Ten active females of normal body composition, determined by body mass index (BMI) and a dual energy absorptiometry x-ray (DEXA) scan, participated in the study. Maximal aerobic …

The Neglected Minority: Interviews With Successful Community College Students From Poverty, Heather Hollifield-Hoyle

Graduate Theses and Dissertations

Poverty in the US is growing at an alarming rate. The current economic climate demands higher education to embrace the economic diversity of all students and to prepare them, regardless of economic class, for a globally competitive workplace. Unfortunately, the higher education community is not as adept at serving low-income students, as it is middle- and upper- income students. Low-income students are less likely than their more affluent peers to enroll in college or graduate. Employing qualitative narrative methods, this dissertation explores the factors that contributed to the persistence and success of 18, low-income, community college students. This study addresses …