Digital Commons Network^™

Systematics Of Protosteloid Amoebae, Lora Lindley Shadwick

Graduate Theses and Dissertations

Because of their simple fruiting bodies consisting of one to a few spores atop a finely tapering stalk, protosteloid amoebae, previously called protostelids, were thought of as primitive members of the Eumycetozoa sensu Olive 1975. The studies presented here have precipitated a change in the way protosteloid amoebae are perceived in two ways: (1) by expanding their known habitat range and (2) by forcing us to think of them as amoebae that occasionally form fruiting bodies rather than as primitive fungus-like organisms. Prior to this work protosteloid amoebae were thought of as terrestrial organisms. Collection of substrates from aquatic habitats …

Crisis Communication Needs Assessment: A Delphi Study To Enhance Instruction For Agricultural Communicators And Other Stakeholders, Allyson Ceary Mcguire

Graduate Theses and Dissertations

Agricultural communicators and industry stakeholders need to be able to develop, prepare and implement crisis communication plans to help assure the sustainability of the agriculture industry should a crisis event occur. A thorough exploration of possible options and needs for training crisis communicators is a needed study in the agriculture industry. Students learning to prepare for managing crises in real life situations are rarely taught in a hands-on, experiential manner. Students can read and analyze case studies pertaining to crises, but without having an actual crisis; little means exist for preparing students for real world situations. There is a need …

Protein Utilization And Requirements In Broiler Breeders, Ricardo David Ekmay

Graduate Theses and Dissertations

Advances in the genetics of poultry have created unintended consequences to the broiler breeder industry. Excessive weight has been shown to have many negative effects, including double hierarchies, multiple ovulations, and fatty liver. In an effort to curb excessive body weight gain, both the protein requirements and feeding strategies of broiler breeders are being revisited. A series of studies were conducted to determine the protein and amino acid requirements of broiler breeders during the production phase and to determine the interrelationship between protein turnover and egg formation. In the first trial, a 2x3x3 factorial study was conducted to determine the …

Effect Of Soyasaponin Fractions On Human Colon Cancer Cells, Joseph Tyler Salyer

Graduate Theses and Dissertations

Group B saponins, the predominant form of saponins in heat-treated soy products, have been shown to possess hypocholesterolemic, antimutagenic, and anticarcinogenic properties. Previous studies have evaluated crude mixtures of soyasaponins, but studies evaluating a single purified soyasaponin as an anticarcinogenic agent are limited. The goal of this study is to examine the effects of purified soyasaponins I and III as well as their aglycone form, soyasapogenol B, as anticarcinogenic agents on the human colon adenocarcinoma cell line Caco-2. Experiments were conducted to determine the effects of purified soyasaponins on cell proliferation, Protein Kinase C (PKC) activity, and cell morphology in …

The Effects Of Phosphorus Enrichment On Leaf Litter Stoichiometry In A Forested Stream, Bryant Baker

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The effects of nutrient (N and P) enrichment on leaf litter decomposition in streams have been investigated extensively, but few have explored how P addition alone affects leaf litter stoichiometry (namely the C:P ratio). This study examined how the P content, C:P ratio and decomposition of two types of leaf litter (the recalcitrant Quercus stellata and the more labile Acer saccharum) responded to P enrichment from nutrient diffusing substrata (NDS) which was either unenriched agar or agar enriched with a moderate or high level of P. Leaf litter was sealed in 0.05 mm mesh bags, which excluded invertebrates, housed with …

Earthworms Of Arkansas And Contributions Of Earthworm Evolutionary Origin And Ecological Group To Nitrogen Cycling In A Model Soil And Tall Fescue System, Peter John Tomlinson

Graduate Theses and Dissertations

Evolutionary origin and ecological niche may impact how earthworm species affect N cycling. Tall fescue (Lolium arundinaceum (Schreb) S. J. Darbysh) infection with the toxic endophyte Neotyphodium coenophialum Glenn, Bacon & Hanlin (E+) may influence earthworm communities in soil compared to non-toxic endophyte (NE+) infected tall fescue. Conversely, different earthworms may contribute different amounts of N to E+ vs. NE+ tall fescue. A field survey was conducted from January 2007 to January 2008 to determine the impact of E+ and NE+ tall fescue, planting date, and seasonal variables, e.g. soil temperature and moisture, on earthworm species, abundances, and population …

Nitrogen Retention And Denitrification In Reservoirs, Erin Grantz

Graduate Theses and Dissertations

Studies coupling direct measurements of micro-scale nitrogen (N) cycle processes with ecosystem-scale flux estimates are needed to determine N retention hotspots within river networks, where up to 50% of terrestrial loading to aquatic systems is retained. This study examined the role of denitrification, a microbially-mediated reactive N removal pathway, in ecosystem-scale N retention in 3 small (< 1 km2), shallow flood-control reservoirs. Annual reservoir N retention was estimated through mass balance modeling of system inputs and outputs. Annual denitrification rates were estimated by combining multiple measurements of seasonal, habitat-specific dinitrogen gas (N2) fluxes. Annual reservoir N retention ranged from 14 - 19 g m-2 in the reservoirs, while reactive N removal through denitrification was 13 - 25 g m-2. Denitrification efficiency, or the portion of the retained N load that was denitrified, was high relative to other lentic systems and was > 100% at 2 sites. Previous lentic denitrification studies may have underestimated denitrification efficiency by not considering water column denitrification, which was 50% of total denitrification at one study reservoir. However, not all potential inputs, most importantly biological N2 fixation, were included in this …

Effect Of Supplemental Trace Mineral Source (Organic Versus Inorganic) On Bull Semen Quality, Matt Rowe

Graduate Theses and Dissertations

Studies indicate that organic forms of trace minerals can improve cow reproductive performance, particularly during periods of stress. However, limited information is available on the effects of organic trace mineral supplementation on bull fertility. The objective of this study was to evaluate the effect of organic versus inorganic trace mineral supplementation on bull semen quality before and after freezing, as measured by computer-assisted sperm analysis (CASA). Angus and Balancer bulls were assigned to inorganic (n = 9) and organic (n = 10) trace mineral treatments, based on initial semen quality, breed, body weight, and age. The bulls were maintained in …

Single Mothers In College: The Effect Of Selected Variables, Rickey Booker

Graduate Theses and Dissertations

Single parent mothers who are currently in poverty may find it difficult to find routes out of poverty and/or even to enrolling in college. Little empirical research has been conducted on low-income single parent mothers who attempt to enroll, persist and graduate college. The current research has shown that single parents are at a high risk of dropping out of college because of many barriers including poverty related issues. This study examined women who had at least one child or dependent, were in poverty, and were first time beginners in college. The purpose for conducting this study was to identify …

Rice (Oryza Sativa) Response To Low Glyphosate Rates As Influenced By Cultivar, Growth Stage, And Imazethapyr Applications, Jason R. Meier

Graduate Theses and Dissertations

Off-target movement of glyphosate onto rice is a perennial concern when rice is grown in close proximity to glyphosate-tolernat crops. If differential tolerance to sub-lethal rates of glyphosate exists among rice (Oryza sativa) cultivars, these cultivars could be utilized in breeding programs or glyphosate-drift sensitive areas. Field and greenhouse experiments were conducted in 2006 and 2007 to examine differences among rice cultivars in response to sub-lethal rates of glyphosate, and to examine imidazolinone-tolerant rice response to imazethapyr and sub-lethal rates of glyphosate applied sequentially to determine the potential for either herbicide to predispose rice to greater injury. In the field …

Water Quality Trends For Section 319 Priority Watersheds In Northwest Arkansas, 1997-2010, Bryan William Bailey

Graduate Theses and Dissertations

Northwest Arkansas contains two Section 319 Priority Watersheds that the Arkansas Natural Resources Commission (ANRC) has identified as being impacted by point and nonpoint sources of pollution (i.e., phosphorus, nitrogen, and sediment), and the Arkansas Water Resources Center (AWRC) has monitored the water quality at several sites within these watersheds. Water-quality data has been collected over the last decade within the Illinois River Watershed (HUC #11110103) and the Upper White River Basin (Beaver Reservoir HUC# 11010001), each watershed containing three sampling sites. The Illinois River Watershed sites are located on the Illinois River, Osage Creek, and Ballard Creek, and the …

Geospatial Tools And Techniques For Watershed Management Using Swat 2009, Naresh Pai

Graduate Theses and Dissertations

In this study, geospatial tools and techniques were developed to support specific aspects of watershed pollution management, such as quantifying land-use change (LUC) impacts, prioritizing subwatersheds, and communicating field-scale impacts, using the soil and water assessment tool 2009 (SWAT 2009) model.

For the land-use change objective, a geospatial tool titled SWAT2009_LUC was developed that enables SWAT modelers to prepare specific input files for simulating concurrent land-use changes during the SWAT 2009 model simulations. Testing of the tool for the Illinois River Drainage Area in Arkansas (IRDAA) watershed showed that the tool accurately represented temporal land-uses within the model. Model simulations …

Photodetectors And Photovoltaic Devices Based On Semiconductor Nanomaterials, Jiang Wu

Graduate Theses and Dissertations

Photodetectors based various nanostructures and plasmon enhanced solar cells are investigated in this dissertation. The motivation of the dissertation rise is driven by urgent need of both high efficiency photodetectors and solar cells.

First, quantum dot infrared photodetectors have been intensely investigated due to their promise in high performance photodetectors. However, the strain-driven growth of quantum dots has hindered the progress of quantum dot photodetectors. The presence of strain in the device presents complexity in designing as well as defects. Therefore, in this project, new designs of quantum dot photodetector structures are presented to improve the control over detection wavelength. …

Analyzing Spring Freeze Impacts On Deciduous Forest Productivity Using Modis Satellite Imagery, Karl Lintvedt

Graduate Theses and Dissertations

The impacts of an April 2007 spring freeze event on the productivity of deciduous broadleaf forest were analyzed using geographic information system (GIS) tools. Forest productivity was modeled using the Enhanced Vegetation Index (EVI), as recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor. Measures of spatial autocorrelation were used to quantify the degree of spatial congruence between a map depicting the severity of the freeze event, and maps modeling forest productivity throughout the year. The results show a geographic correlation between the unseasonably low minimum temperatures sustained during the freeze and the unusually low forest productivity that followed. …

Hospitality Students Perceptions About High Risk Behaviors In Relation To Destructive Behaviors And Decision Making, Boris A. Roslov

Graduate Theses and Dissertations

This study investigated hospitality students' perceptions regarding alcohol consumption and personal actions related to high risk behaviors. Those behaviors included: sexual encounters and binge drinking, and their effect on academic tasks and performance. The study investigated whether the hospitality student who is employed full time consumes alcohol at a higher level than a hospitality student does that is not employed full time.

Portrait Of Hal: A Narrative Case Study That Illuminates The Transformative Influence Of Generativity And Life Stories On The Legacy Of An Adult Educator/Learner, Margaret Ann Voelkel

Graduate Theses and Dissertations

This qualitative narrative case study uses the Social science portraiture approach to explore how the learning experiences of a retired manufacturing manager have influenced his identity and his choice of an encore career in education. Hal B. is a retired manufacturing manager in his 70s who is now an instructor of leadership, management, and process improvement for working adults in a mid-south regional university. The portraiture approach to Hal's experience of a second career as an educator exemplifies the ways in which generativity, a person's need to care for and prepare future generations (Erikson, 1980), and storytelling are factors that …

Exploring First Generation African American Graduate Students: Motivating Factors For Pursuing A Doctoral Degree, Stephanie G. Adams

Graduate Theses and Dissertations

The purpose for conducting the study was to examine the factors that motivate African-American first-generation students to pursue doctoral education at a four-year public university. There has been little research on the influence academic or non-academic factors have on first-generation graduate student motivation. Similarly, little research exists that explored how factors might vary by ethnicity. Based on the projected increase of post-baccalaureate enrollment each year (Aud, Hussar, Planty, Snyder, Bianco, Fox, Frohlich, Kemp, Drake, 2010), first-generation African-Americans will become more interested in attending graduate school. It is important to gain a better understanding of the factors and influences that impact …

Determination Of Poultry Litter's Nitrogen-Fertilizer Value For Winter Wheat Production, Brett Lee Gordon

Graduate Theses and Dissertations

Nitrogen (N) availability in poultry litter (PL) applied in the fall as a nutrient source for winter wheat (Triticum aestivum L.) has not been adequately characterized. Our objective was to determine a potentially available N (PAN) coefficient based on the inorganic-N fertilizer equivalence (FEQ) of fall-applied PL to winter wheat via field and laboratory research. Wheat grown at six site-years received 0, 84 and 168 kg N ha-1 as PL applied preplant and/or at-planting. The FEQ of PL-N was based on growth and yield responses of wheat fertilized with 22 to 191 kg N ha-1 applied in late winter as …

Studies Toward The Development Of A Microelectrode Array For Detection Of Dopamine Through Redox Cycling, Anupama Aggarwal

Graduate Theses and Dissertations

Redox cycling is an electrochemical technique that cycles the reversible redox species between its oxidative states repeatedly on generator and collector electrodes. Two or more individually-addressable microelectrodes located close to each other allow redox cycling to be possible. Electrochemical behavior of a biologically important molecule, dopamine is examined under redox cycling conditions. To our knowledge, this is the first report on detection of physiological concentration of dopamine in presence of up to 100 times excess ascorbate with the use of redox cycling, without the involvement of polymer coating such as Nafion®.

Microfabrication was used to produce different geometries (parallel bands …

The Relation Between Children's Perceived Containment And Parental Antisocial Behavior, Joye L. Henrie

Graduate Theses and Dissertations

Researchers have invoked a variety of theories when discussing the relation between children's orientation to authority and the development of antiSocial behavior (ASB). Here, the focus is children's sense of containment. Previous studies revealed an association between perceived containment and child externalizing behaviors. In this study, the degree to which a child's sense of containment is related to parents' level of ASB was examined. One hundred sixty aggressive children and their parents participated. I hypothesized that ineffective discipline would moderate the relation between parent ASB and child perceived containment. I expected to find an inverse relation between parents' level of …

Critical Torque For Kink Formation In Double-Stranded Dna, Hao Qu, Yong Wang, Chiao-Yu Tseng, Giovanni Zocchi

Physics Faculty Publications and Presentations

We measure the bending energy of double-stranded DNA in the nonlinear (sharply bent) regime. The measurements are obtained from the melting curves of stressed DNA ring molecules. The nonlinear elastic behavior is captured by a single parameter: the critical torque τc at which the molecule develops a kink. In this regime, the elastic energy is linear in the kink angle. This phenomenology is the same as for the previously reported case of nicked DNA. For the sequences examined, we find τc=31 pN×nm. This critical torque corresponds to a characteristic energy scale (π/2)τc=12 kT room relevant for molecular biology processes associated …

Minutes Of The Faculty Senate Meeting, November 9, 2011, University Of Arkansas, Fayetteville. Faculty Senate

Faculty Senate Minutes

No abstract provided.

2011 Northwest Arkansas Report Card, Gary Ritter

Education Report Card

Each year, the Office for Education Policy creates a state report card that highlights recent student achievement, achievement gaps, student demographics, and financial information for schools across the entire state of Arkansas. Because we are housed in the University of Arkansas at Fayetteville, which is in the Northwest Arkansas region, we have created an edition of the report card specific to the this region. Here, we present the most recent report card data for schools in Washington and Benton counties in Northwest Arkansas.

The following districts are included for the Northwest Arkansas (NWA) average: Bentonville, Decatur, Elkins, Farmington, Fayetteville, Gentry, …

Mole Street Journal, October 2011, University Of Arkansas, Fayetteville. Dept. Of Chemistry And Biochemistry

Mole Street Journal

No abstract provided.

Mole Street Journal, September 2011, University Of Arkansas, Fayetteville. Dept. Of Chemistry And Biochemistry

Mole Street Journal

No abstract provided.

Jeanne Clery Disclosure Of Campus Security Policy And Campus Crime Statistics Report, 2010, University Of Arkansas, Fayetteville. Police Department

Jeanne Clery Disclosure of Campus Security Policy

No abstract provided.

Minutes Of The Faculty Senate Meeting, September 14, 2011, University Of Arkansas, Fayetteville. Faculty Senate

Faculty Senate Minutes

No abstract provided.

Athletic Training Education Program Newsletter, Fall 2011, University Of Arkansas, Fayetteville. Athletic Training Education Program

Athletic Training Education Newsletter

No abstract provided.

Mole Street Journal, August 2011, University Of Arkansas, Fayetteville. Dept. Of Chemistry And Biochemistry

Mole Street Journal

No abstract provided.

Research Frontiers, Fall 2011, University Of Arkansas Fayetteville. Office Of University Relations

Research Frontiers

No abstract provided.