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The Role Of Centromeric Chromatin And Kinetochore-Associated Factors In Chromosome Segregation, Wesley Williamson

Graduate Theses and Dissertations

Previous work in our lab has identified a point mutation in HTA1, one of the genes encoding histone H2A, which causes an increase-in-ploidy phenotype in Saccharomyces cerevisiae. This histone mutant strain was used to carry out a transposon insertion screen to identify suppressors of the increase-in-ploidy phenotype. This screen identified all three subunits of the Hda histone deacetylase complex, HDA1, HDA2, and HDA3. This study aims to elucidate the function of the Hda complex in chromosome segregation by exploring interactions among the members of the complex, as well as interactions between Hda complex and kinetochore components. …

Design Of A Pretreatment And Enzymatic Saccharification Scheme Of Understory From Managed Pine Forest For A Biochemical-Refinery Platform: The Example Of The Sweetgum Tree, Angele Djioleu

Graduate Theses and Dissertations

The possibility of using sweetgum from southern pine dominated forests as a biobased refinery feedstock was investigated. First, a baseline hydrolysis scheme for sweetgum wood and bark was designed. Sweetgum wood and bark were pretreated with 0.98% (v/v) sulfuric acid at 140°C for 30, 40, 50, 60 or 70 min and at 160°C for 30, 40, 50 or 60 min. The water insoluble solid (WIS) fraction was hydrolyzed with a cellulase enzyme cocktail. Results showed that maximum xylose and glucose yields from the wood were 82 and 86%, respectively. Similarly, the respective maximum yields of xylose and glucose from the …

The Biological Control Of Spotted Knapweed In The Southeastern United States, Carey R. Minteer

Graduate Theses and Dissertations

Spotted knapweed is an invasive, short-term-perennial plant that is native to Eurasia. It was accidentally introduced into North America in the early 1890's and has since spread across The United States and Canada. Spotted knapweed degrades rangelands and pastures by negatively impacting native plants, increasing soil surface runoff and stream sediment yields, and reducing soil infiltration. A biological control program for spotted knapweed using Larinus minutus (Coleoptera: Curculionidae), was initiated in Arkansas in 2008. In this dissertation I described the releases of L. minutus and investigated the adult activity in the southeastern United States (Chapter 1), investigated the effects of …

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 …

Effects Of Obesity On Thermoregulation And Cardiovascular Function During Exercise In Females, Jon David Adams

Graduate Theses and Dissertations

Previous research has shown that obese individuals are at greater risk for heat illnesses because of impaired thermoregulation. However, laboratory studies investigating cardiovascular and thermoregulatory function in obese individuals are difficult to interpret because of low sample sizes and methodological concerns. The purpose of this study was to determine if there are differences in thermoregulatory and cardiovascular function between obese and non-obese females. Twenty-four females, 13 obese (43.3 ± 4 .3 % fat, 77.2 ± 13.7 kg) and 11 non-obese (27.8 ± 6.0 % fat, 55.7±6.7 kg), cycled for 60 min in a warm environment (~40°C, 30% humidity) at a …

The Relationship Of Peer Acceptance, Age, Gender, Ethnicity, And Appearance Among Preschoolers, Kora Klaire Stuffelbeam

Graduate Theses and Dissertations

The purpose of this study was to examine preschool children's acceptance of peers. The term peer acceptance is defined as "the degree a child is Socially accepted or rejected by his or her peer group." Johnson et al. (2002) found children between the ages of three and five were able to develop friendships and Social skills that would impact their acceptance among peers. The study determined if children based their choice of peers according to a child's age, gender, ethnicity, appearance, and/or Social skills. The subjects of this study were 31 children whose ages were three-, four-, and five-years-old who …

Family Policies And Institutional Satisfaction: An Intersectional Analysis Of Tenure-Track Faculty, Heather Lee Schneller

Graduate Theses and Dissertations

Gender and faculty career advancement have been examined with a focus on academic work environment, including faculty workloads, mentoring relationships, access to research networks, and work-life balance. Previous studies concerned with gender, employment, and care work only have considered child care. Additionally, the exploration of faculty and care work focused specifically on gender instead of examining the interaction of race and gender. To date, no study on academic work-life policies includes faculty perceptions of their importance and effectiveness nor has the faculty assessment of eldercare policy been examined in relation to career success.

Guided by an intersectional perspective, this study …

Habitat Modeling Of Three Endemic Crayfish Species In The Black River Drainage Of Missouri And Arkansas: Factors Affecting Distribution And Abundance, Matthew Stephen Nolen

Graduate Theses and Dissertations

The Ozark faunal region of Missouri and Arkansas harbors a high level of aquatic biological diversity, especially in regards to endemic crayfish. Orconectes eupunctus, Orconectes marchandi, and Cambarus hubbsi are three such endemics that are threatened by a limited natural distribution and the invasions of Orconectes neglectus. I sought to determine how natural and anthropogenic factors influence these three species across multiple spatial scales. Local and landscape data were used in decision tree analyses (CART) to determine their influence effect on presence/absence and density of the three species. Predictive models were validated using k-fold cross validation. O. eupunctus presence was …

Assessing The Impacts Of Surface Water Removal For Use In Natural Gas Extraction On A Watershed Level, Carrie Ann Davis

Graduate Theses and Dissertations

In this study, the Soil and Water Assessment Test (SWAT) was used as a tool to predict whether diffuse water removal from the Cadron Creek watershed for use with natural gas development would have an impact on downstream flow within the watershed. Cadron Creek watershed expands across four counties within Arkansas and is located in the Fayetteville Shale Gas region. This region is experiencing significant growth in natural gas development. Successful development of shale gas depends on the identification of what water supplies are available for production without interfering with community and environmental needs. The SWAT model used to evaluate …

Mapping Xenophobic Violence In South Africa: Modeling Spatial Relationships Between Group Grievances And Opportunities To Measure The Propensity For Xenophobic Violence, Eric Holder

Graduate Theses and Dissertations

Xenophobia can be defined as the hatred or fear of foreigners or strangers or of their politics or culture (Ngwane et al., 2008). This sentiment reached its tipping point in urban areas across the Republic of South Africa in May 2008 when mass, widespread and systematic attacks against African non-nationals took place across the country. Although previous research agrees on who played the various roles during this crisis event (Everatt, 2010), little research has been carried out to create a predictive model to assess where future violence could occur based on a set of conflict indicators. The purpose of this …

Phenotypic Plasticity Of Rattlesnake Trophic Morphology, Matthew Thomas Smith

Graduate Theses and Dissertations

The trophic morphology of gape-limited predators constrains the shape and size of prey items they can ingest. Trophic morphology consists of any morphological feature that is involved in the handling and ingestion of food. Diet has a profound effect on the morphology of many gape-limited predators. Identifying how prey type and resource level affect the morphology of different populations is an essential step in understanding the mechanisms contributing to patterns of morphological diversity. Species interactions (Chapter 1) induce plasticity in morphology that can lead to increased fitness, morphological divergence, and eventually speciation.

In Chapter 2, a laboratory study tested the …

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), …

New Applications Of Mass Spectrometry For Drug And Lipid Analysis, Elizabeth Lauren Emerson

Graduate Theses and Dissertations

Mass spectrometry is an important tool used in many different disciplines and settings that include forensics, drug discovery, environmental analysis, and proteomics. Gas chromatography - mass spectrometry (GC-MS) and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI - TOF MS) are two of the most important instruments used for analysis of compounds. Chapters 1 and 2 of this discussion use GC-MS for the investigation of synthetic cannabinoids in `K2' incense products and the detection of metabolites in urine samples from individuals suspected of consuming these mixtures. Analytical standards were synthesized and used for identification and confirmation of structures. Detection of …

Effect Of Heat Treatments On The Properties Of Two Long-Grain Rice Cultivars During Storage, Youngbum Lee

Graduate Theses and Dissertations

During storage, the milling and physicochemical properties and eating quality of rice change, which is generally termed `aging'. Aged rice is preferred by processors, and there are attempts to develop accelerated aging process using various heat sources. In this study, the effects of various heat treatments and their influence on the milling, pasting, thermal, and cooking properties of two long-grain rice cultivars during storage were investigated using a full-factorial experimental design. Two long-grain rice cultivars, Wells and XP723, was treated with 8 different heat treatments including one control and stored at room temperature for 180 days. Heat treatments included 2 …

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 …

Long-Term Effects Of Rice Rotation, Tillage, And Fertility On Near-Surface Soil Carbon And Nitrogen Cycling, Jill Marie Motschenbacher

Graduate Theses and Dissertations

Rice (Oryza sativa L.)-based cropping systems are different from other row crops due to the flood-irrigation scheme used from about one month after planting to a few weeks prior to harvest. The frequent cycling between anaerobic (i.e., flooding during the growing season) and aerobic (i.e., generally, the remainder of the year) conditions can influence the rate of soil organic matter (SOM) decomposition, which can greatly influence carbon (C) and nitrogen (N) storage and sequestration in the soil over time. Therefore, a study was conducted on a silt-loam soil (fine, smectitic, thermic, Typic Albaqualf) at the Rice Research and Extension Center …

Evaluation Of The Effects Of Absorption Field Product Architecture Type On Effluent Dispersal And Soil Chemical Properties In A Profile-Limited Soil, Nina J.M. Prater

Graduate Theses and Dissertations

On-site wastewater treatment systems (OWTSs) are commonly used by households in areas of low population density to treat household wastewater and recycle it back to the environment. The traditional absorption field product used in OWTSs is a pipe-and-gravel architecture type, which has been used for decades and is the basis for most design regulations. However, new products of differing architecture types including chambers, polystyrene-aggregate, pipe-and-tire-chip, and gravel-less-pipe systems have recently become available. A three-year field study was conducted in Bethel Heights, AR to assess the performance of several newer products and to compare different architecture types to the traditional pipe-and-gravel …

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 …

Timing Of Castration, With Or Without Analgesia, On Growth Performance, Hematology, And Behavior Of Beef Calves, April C. Brown

Graduate Theses and Dissertations

Angus-sired (n = 30) and Hereford-sired (n = 32) bull calves were assigned randomly to 1 of 4 treatments. Treatments were 1) surgical castration near birth, 2) oral administration of the analgesic meloxicam (1 mg/kg of body weight) followed by surgical castration near birth, 3) surgical castration at weaning, or 4) surgical castration at weaning with oral administration of the analgesic meloxicam (1 mg/kg of body weight). Data was recorded for behavior, hematology, and growth at birth and weaning. Calf standing and lying activity was monitored at both stages by recording x and y axis positions of a data logger …

Exploring The Surface Liquid And Lake Regions Of Titan With Laboratory Experimentation And Cassini Spacecraft Data, Felix Casimir Wasiak

Graduate Theses and Dissertations

The surface liquids and lake regions of Titan are studied utilizing three unique techniques, the results of which are reported in this dissertation. The development of a facility to simulate the surface conditions of Titan, and to conduct experiments on samples within that facility, brings an understanding of Titan's surface not possible through observation and modeling alone. The properties of this facility are presented, including conceptual methodology, design, implementation, performance, and experimental results. The facility, the main component of which is a simulation chamber, allows for Titan temperatures of 90 - 94 K and a 1.5 bar N2 atmosphere. The …

Alternative Herbicide Control Options For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri), George Macmillan Botha

Graduate Theses and Dissertations

The occurrence of glyphosate-resistant (GR) Palmer amaranth has prompted a shift in weed management strategies worldwide. Studies were conducted with the aim to (1) establish and compare the degree of tolerance of GR Palmer amaranth populations; (2) assess the efficacy of glufosinate, tembotrione, 2,4-D or dicamba, applied alone or tank-mixed, on Palmer amaranth with higher tolerance to glufosinate in the greenhouse and corn field, and (3) establish the mechanism involved in the tolerance of Palmer amaranth to glufosinate. Tembotrione, 2,4-D, dicamba, and glufosinate applied at 1x controlled 80 to 100%, 98 to 100%, 84 to 100%, and 94 to 100% …

What Is The Participant Learning Experience Like Using Youtube To Study A Foreign Language?, Yuan-Hsiang Lo

Graduate Theses and Dissertations

This research is to explore and understand participants' experience using YouTube to learn a foreign language. YouTube and learning has become more and more popular in the recent years. The finding of this research will be adding more understanding to the emerging body of knowledge of YouTube phenomenon. In this research, there are three interviews and two questionnaires. The interviews are conducted to find in-depth responses from participants; the questionnaires are used to inquire demographic and basic information about the participants. There are twelve themes found in this research. These themes reflect on the perceived experience using YouTube to learn …

The Lived Experience Of The Parents Of High School Dropouts: A Phenomenological Study, Christine Ann Silano

Graduate Theses and Dissertations

The purpose of this study is to describe the experiences and perceptions of parents whose children did not receive a high school diploma. This subpopulation has been rarely studied. The central question is, "What are the perceptions and experiences of the parents of public high school dropouts as they pertain to schools, their children, and themselves?"

This phenomenological study examined the lived experience of the parents of high school dropouts. Five women and one man participated in the study by sitting for interviews. The collected interview data was transcribed and analyzed using qualitative methodology including open and axial coding as …

A Comparison Of Student Success By Faculty Qualifications, Kristine A. Garner

Graduate Theses and Dissertations

Providing the best qualified faculty to ensure the most successful student outcomes is a priority in higher education. The use of adjunct faculty in colleges and universities is continually increasing, especially for lower level courses. Previous research has come to conflicting conclusions regarding the quality of adjunct faculty. Indicators of student success were compared between part-time instructors with professional doctoral degrees and full-time instructors with academic doctoral degrees. Results of statistical analyses of both a comparison of final grade distributions and knowledge of course content determined that there were no significant differences between two comparable groups of students in a …

Ideology In Popular Late Twentieth And Twenty-First Century Children's And Young Adult Literature And Film, Iris Grace Shepard

Graduate Theses and Dissertations

Texts created for the consumption of children and young adults are not simple texts made for the sole purpose of entertaining young audiences. In fact, these texts are complicated, multi-faceted texts that function both in the creation and performance of childhood. Children's and young adult literature and film disseminated mainstream ideology about young people's place in society and attempt to enculturate young readers and viewers in regards to race, gender, age, and Social class. However, by helping young people interact critically with these texts, critical thinking skills as well as a passion for reading can be fostered. In addition, by …

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 …

Taxonomy And Dna Barcoding In The Genus Manfreda (Salisb.) Asparagaceae, William David Ritchie

Graduate Theses and Dissertations

The genus Manfreda Salisb. of Asparagaceae is a genus of potential horticultural interest and is currently subject to breeding efforts at the University of Arkansas. A lack of taxonomic clarity however undermines the classification of potential inter - and intrageneric hybrids. The study aims to assess existing species delimitation within the genus Manfreda employing morphology while investigating the potential utility of Consortium for the Barcode of Life Plant (CBOL) DNA Barcodes for identification of specific taxa and an External Transcribed Spacer (ETS) - Internal Transcribed Spacer (ITS) DNA barcode for developed hybridized taxa.

Observation of 855 herbarium specimens facilitated phylogenetic …

Capillary And Microchip Electrophoresis For The Monitoring Of Disease Causing Amyloid Proteins, Elizabeth Nancy Pryor

Graduate Theses and Dissertations

The detection of oligomers and aggregates formed by two amyloid proteins, insulin and amyloid-beta (AB), is of particular importance due to the role which these species play in Diabetes and Alzheimer's disease, respectively. However, existing techniques are limited in the ability to detect insulin and AB; oligomers due to the fact that these early aggregates are transient, present at low concentrations, and difficult to isolate. Improvements must be made to existing techniques or alternative techniques must be explored in order to identify and quantify the size of these oligomeric and aggregate species without disrupting their structure.

Capillary and microchip electrophoresis …

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 …

Diagenesis And Reservoir Characterization Of The Pennsylvanian Middle Atoka Formation, Sebastian And Logan Counties, West-Central Arkansas, Elvis Chekwube Bello

Graduate Theses and Dissertations

The Middle Atoka Formation evolved from a stable passive margin during the early Pennsylvanian time to a rapidly subsiding basin, with the sedimentary fill thickening greatly southward during the middle Pennsylvanian time. The basin dips in north-south direction. An east-west anticlines and synclines were observed.

The purpose of this study is to establish the stratigraphic units, reservoir geometry and distribution, and infer the depositional environments and reservoir quality. Well correlation and petrographic studies are used to achieve the goals.

Sandstone Point Count method was used. The Point Counts was divided into five categories. They include the framework grains (quartz, feldspar, …