Digital Commons Network^™

Transformation Of Swine Manure And Algal Consortia To Value-Added Products, Mahmoud A. Sharara

Graduate Theses and Dissertations

The swine production sector is projected to grow globally. In the past, this growth manifested itself in increased herd sizes and geographically concentrated production. Although economically sound, these trends had negative consequences on surrounding ecosystems. Over-application of manure resulted in water quality degradation, while long-term storage of manure slurries was found to promote release of potent GHG emissions. There is a need for innovative approaches for swine manure management that are compatible with current scales of production, and increasingly strict environmental regulations.

This study aims to investigate the potential for incorporating gasification as part of a novel swine manure management …

The Role Of Attention In Ego-Depletion, Garrett Pollert

Graduate Theses and Dissertations

The resource model of ego-depletion is unable to account for the results of several ego-depletion studies, whereas a recent mechanistic revision by Inzlicht and Schmeichel (2012) has focused on the role of attention and motivation in an effort to explain the phenomenon. Assessment of attention's role in restrained and unrestrained eaters may provide evidence that motivation and attention work in tandem to affect one's ability to exert self-control. In this experiment, college-aged females participated in two studies to examine the role of attention in ego-depletion effects. Study 1 evaluated the effect of ego depletion on attention via a dot probe …

The Paleoepidemiology Of Malaria In The Ancient Near East, Nicole Elizabeth Smith

Graduate Theses and Dissertations

The end of the Late Bronze Age in the Near East (1300 - 1200 BCE) saw the widespread collapse of several large cultural centers, the reasons for which are a subject of continued debate. Evidence from events leading up to this cultural collapse suggest epidemic disease may have factored into the eventual downfall of these early civilizations. Recent DNA analysis from Egyptian mummies who lived during the period leading up to the Late Bronze Age collapse identified malaria in several elite individuals, suggesting the widespread prevalence of this infectious disease in Egypt. However, the exact prevalence, antiquity, and dynamics of …

An Examination Of Psychoeducation And Its Potential Modifying Influence On Alcohol Use Patterns Among Adults Reporting Co-Occurring Posttraumatic Stress Symptoms And Hazardous Alcohol Consumption, Sarah Jo Bujarski

Graduate Theses and Dissertations

Research has suggested that consumption of alcohol in the presence of elevated posttraumatic stress symptom (PTSS) may serve an avoidant function to cope with negative emotions. These coping-related motives for use are theorized to both maintain PTSS and relate to poorer prognoses in treatment for alcohol use disorders (AUDs). Treatments utilizing coping skills training, which typically also involves educating clients about the negative consequences of drinking alcohol to cope, suggest the utility of targeting coping behaviors to reduce alcohol use. These studies, however, have not attempted to isolate the effects of psychoeducation on alcohol-related factors. The current study investigated the …

"V Is For Violin" - An Original Playscript, Brittany Taylor

Graduate Theses and Dissertations

As and MFA playwrighting candidate, I was given the opportunity to witness a fully realized production of my work. For this academic opportunity I chose the "V is for Violin." I will discuss the genesis of the idea, the evolution of the play, research conducted, and what I learned in the production process of the show.

Dlipin-A Link Between Lipid Metabolism, Glucose Homeostasis And Growth In Drosophila Melanogaster, Sandra Schmitt

Graduate Theses and Dissertations

Lipins are a family of highly conserved proteins found from yeasts to humans. Lipins have dual functions, serving as phosphatidate phosphatase enzymes (PAP) in the synthesis of neutral fats (triacylglycerols, TAG) and as transcriptional co-regulators that affect the expression of genes involved in lipid and fatty acid metabolism. Thus, they play central roles in metabolic control. Disruption of Lipin function has been implicated in lipodystrophy, obesity and insulin resistance. Using dLipin, the Drosophila homolog of Lipin, as a model, I aimed to elucidate the relationship between the two biochemical functions of Lipin and metabolic homeostasis. I discovered there is a …

Impact Of Professional Learning Community Design On Teacher Instruction, Carol Jeanette Turner

Graduate Theses and Dissertations

This descriptive case study closely examined a professional learning community in an Arkansas middle school. The site was selected because the school was removed from the state's school improvement list after implementing professional learning communities. The purpose of the study was to determine how the design of a professional learning community impacts teacher instruction in a middle school setting. The literature reviewed included historical perspective, definitions and characteristics of professional learning communities, teacher professional development, and teacher effect on student achievement. Eight teachers, one principal, and one instructional facilitator were interviewed about the professional learning communities in their school. The …

Intestinal Inflammation Model Inducing Gut Leakage By Different Methods In Broiler Chickens Using Fitc-D As A Marker, Eduardo Vicuna

Graduate Theses and Dissertations

Traditionally, antibiotic growth promoters (AGP) have been used in food animals to reduce enteric inflammation and maintain intestinal homeostasis, thus improving performance. Due to increasing restrictions regarding the use of AGP, precise and high throughput enteric inflammation models and markers to search for effective alternatives are urgently needed. Oral administration of fluorescein isothiocyanate dextran (FITC-d) and its passage into blood can be used as a marker for tight junction permeability. FITC-d is a large molecule (3-5 kDa) which does not usually leak through the intact gastrointestinal tract barrier. However, when conditions disrupt the tight junctions between epithelial cells, the FITC-d …

Effects Of Landscape Disturbances On Autotrophic Processes Within Arkansas Ozark Streams, Bradley J. Austin

Graduate Theses and Dissertations

Land-use change is one of the most widespread human impacts and can influence abiotic and biotic processes within surrounding streams. For example, streams in agricultural and urban watersheds receive greater light and nutrient inputs that can promote increased algal growth and primary production. Natural gas (NG) infrastructure development, a recent land use change in many regions, may also stimulate forested stream primary production, by reducing forest cover and increasing sediments and nutrient transport. I sampled streams across a NG activity gradient for algal biomass and gross primary production (GPP) to assess potential effects of this emerging land-use type. Algal biomass …

Phylogeny And Diversity Of Entamoeba In Cockroaches, With An Emphasis On Periplaneta Americana, Mustafa Husain Fakhri

Graduate Theses and Dissertations

While the parasitic Amoebozoan Entamoeba histolytica has been well-studied for its role in human pathogenesis, the biodiversity of invertebrate-inhabiting Entamoeba has scarcely been investigated. Using molecular methods, I searched for Entamoeba in the guts of cockroaches from four of the six Blattodean families. Entamoeba small-subunit rRNA genes were recovered from all eight species of cockroaches tested, five of which represent newly discovered hosts. Phylogenetic analysis of over 190 sequences revealed a novel and highly diverse clade of cockroach-inhabiting Entamoeba, separate from the clade predominated by vertebrate-inhabitants. These results double the known genetic diversity of Entamoeba and suggest that they may …

Controls On Dissolution Rate Variation At A Pair Of Underflow-Overflow Springs At The Savoy Experimental Watershed, Kiefer Allen Vaughn

Graduate Theses and Dissertations

Physical dissolution experiments and numerical modeling have been used in the past to study limestone dissolution rates. Numerical models have typically used constant dissolution rates, whereas rates in nature vary in time. Limestone tablets allow natural estimation of rates over month time scales, but these rates cannot necessarily be extrapolated to geologic timescales and also do not aid our understanding of short term variability. This study characterizes natural variability in these rates and examines potential causes of that variability from first principles. This may enable more accurate projections of dissolution rates within models. This study combines measurement of physical and …

Defining Primary And Academic Discourse Through Instructional Methods In A Single Junior High Classroom, Ashley Nicole Gerhardson

Graduate Theses and Dissertations

In this study, I examine the use of academic discourse in the school setting and discuss the relation of the primary discourse to academic discourse. I focus on the verbal exchanges between a teacher and her students as these students acquire the academic discourse of the English classroom. The study focuses on the ideas of primary discourse and secondary or academic discourse as presented by Gee (1996) and focuses on his idea of Social languages.

Using a microethnographic study, I develop the idea of how the teacher related to her students and how a single educator felt about the purpose …

Understanding The Evolution Of Aggregative Multicellularity: A Molecular Phylogenetic Study Of The Cellular Slime Mold Genera Sorodiplophrys And Pocheina, Alexander Tice

Graduate Theses and Dissertations

Cellular slime molds are amoeboid protists that have a unicellular trophic phase and multicellular dispersal stage formed through the aggregation of individuals in their life cycles. These organisms were once thought to form a monophyletic group in the Mycetozoa. After careful morphological, ultrastructural, and molecular studies, cellular slime molds are now thought to be distantly related organisms that have all converged on the cellular slime mold habit. The following thesis consists of two molecular phylogenetic studies on two named genera of cellular slime mold for which little or no molecular data were publically available. In the first study, gene sequence …

Distribution Of The Egyptian Goose (Alopochen Aegyptiacus) In Northwestern Arkansas And In The United States Of America, Cameron Chesbro

Graduate Theses and Dissertations

The Egyptian Goose (Alopochen aegyptiacus) is an exotic member of the Anatidae that has been residing in northwestern Arkansas since the 1980s (Smith and James 2012). Following the discovery of Egyptian Geese in the area, not much attention has been given to the consequences of population increase. The Egyptian Goose has shown many diverse population growth patterns in areas where it has been introduced and started feral populations. The purpose of this study was to assess the current population size of the Egyptian Goose in northwestern Arkansas,and confirm successful breeding. The methods used in this study included conducting road surveys …

Nutrient Management For Growing Dandelion (Taraxacum Officinale L.) In Nutrient Film And Deep Flow Hydroponics, Reetinder Gill

Graduate Theses and Dissertations

This research study was conducted to determine an optimal nutrient strategy for dandelion production in nutrient film technique (NFT) and deep flow technique (DFT) systems of hydroponics. It was achieved by growing dandelion at varying levels of nutrient solution concentration and pH in both NFT and DFT systems. Additionally, an optimal nutrient solution concentration and timing of application for dandelion seedling production was also determined.

Application Of Essential Oil Compounds And Bacteriophage To Control Staphylococcus Aureus, Anisha Ghosh

Graduate Theses and Dissertations

Staphylococcus aureus is one of the most important pathogens, causing various diseases in humans and animals. In addition, S. aureus is a common foodborne pathogen. As methicillin- resistant S. aureus (MRSA) becomes increasingly prevalent, controlling this pathogen in animals and humans with standard antibiotic treatment has become challenging. Combinations of different antimicrobial agents represent one of the most promising approaches for combating multidrug - resistant bacteria both for treatment of clinical disease as well as in food. Two such antimicrobials with potential application in the food industry include essential oils (EO) and host-specific bacteriophage (phage). The objectives of this study …

Failure To Launch? Understanding Variations In Emerging Adult Flight Patterns, Christina Ashley Williams

Graduate Theses and Dissertations

What does the transition to adulthood look like for emerging adults? This study proposes that popular cultural ideas like "failure to launch" imply an oversimplified dichotomy that does not account for the multiple "flight patterns" into adulthood. Focusing on the narratives of six interview cases selected from the larger sample of interviewees from Wave 4 of the National Study of Youth and Religion and drawing on the quantitative data from the broader survey sample, this mixed-methods approach examines in-depth, narrative experiences and the ways structural barriers vary between upper-middle, lower-middle, and working class emerging adults. We find that emerging adulthood …

Effects Of Chemical And Enzymatic Modifications On The Starch-Inclusion Complex Formation, Emily Arijaje

Graduate Theses and Dissertations

Starch-inclusion complexes have been proposed as delivery tools for bioactive molecules; however complexation yield is generally low with low solubility, which may limit the bioavailability of the included molecule. It was proposed that chemical (acetylation) and/or enzymatic (isoamylase and beta-amylase) modifications of starches prior to complex formation with fatty acids of different structures, including stearic, oleic and linoleic acid, may help increase complexation yield and solubility of the resulting starch complexes. Potato starch had a significantly higher complexation yield than common corn and high amylose (~70%) corn starches after debranching combined with a beta-amylase treatment. Debranched waxy maize starch and …

The Production Of Biobutanol From Biomass Via A Hybrid Biological/Chemical Process, Thomas Melvin Potts

Graduate Theses and Dissertations

Biobutanol use as a fuel began in the late 19th century. Problems remain in economic viability. A review of the state of the art and need for technical advances is presented.

The technical potential of producing biofuel from a naturally occurring macroalgae was studied. The algae grow in Jamaica Bay, New York City, in contaminated water. The process consisted of mechanical harvesting, drying, grinding, and acid hydrolysis to form an algal sugar solution. Clostridium beijerinckii and C. saccharoperbutylacetonicum were used in an acetone butanol ethanol (ABE) fermentation to make butanol. Fermentation was followed by distillation Butanol concentrations during fermentation reached …

Simulation In Algorithmic Self-Assembly, Jacob Hendricks

Graduate Theses and Dissertations

Winfree introduced a model of self-assembling systems called the abstract Tile Assembly Model (aTAM) where square tiles with glues on their edges attach spontaneously via matching glues to form complex structures. A generalization of the aTAM called the 2HAM (two-handed aTAM) not only allows for single tiles to bind, but also for "supertile" assemblies consisting of any number of tiles to attach. We consider a variety of models based on either the aTAM or the 2HAM. The underlying commonality of the work presented here is simulation. We introduce the polyTAM, where a tile system consists of a collection of polyomino …

Phenotypic And Functional Genomics Analyses Of Salmonella For Food Safety Applications, Turki Dawoud

Graduate Theses and Dissertations

Non-typhoidal Salmonella species have been major foodborne zoonotic pathogens causing serious problems in public health and food industry for several decades. Numerous Salmonella species have frequently been associated with different food commodities mainly poultry meat, eggs, and their products. This dissertation begins with a literature reviews discussing many aspects of Salmonella generally; and subsequently focused on two serotypes, Salmonella Enteritidis and S. Typhimurium as they are at the top of all other serovars responsible for most illness cases and outbreaks. In addition, some Salmonella strains have exhibited their ability to tolerate and survive many food processing treatments. We can divide …

Novel Separation Methods Using Electrodialysis/Electrodeionization For Product Recovery And Power Generation, Alexander Miguel Lopez-Rosa

Graduate Theses and Dissertations

The use of electrodialytic separations for the purification of products has been a vital technique for the past 50 years in the chemical industry. Originally used for demineralization and desalination, electrodialysis and its counterparts have expanded to assist in product purification, waste and hazard removal, and power generation. This research focused on the development of high purity organic acids purification with low power requirements. Work resulted in the development of a new type of electrodialysis process, specifically the use of ionic liquids as a secondary solvent for the development of dual solvent electrodialysis. Through dual solvent electrodialysis, ions were recovered …

Poultry Production Messaging: A Content Analysis Of Three National Newspapers From 1994 To 2014, Stuart Estes

Graduate Theses and Dissertations

Consumers are increasingly concerned with the use of antibiotics and hormones in poultry production, and the news media is the primary way consumers gain knowledge about this subject. This study assessed articles about antibiotic and hormone use in poultry production from the New York Times, USA Today, and the Wall Street Journal from 1994 to 2014. This study employed a content analysis methodology to assess selected articles (n = 139) for key messaging about antibiotic and hormone use in poultry production, article tone, article framing, and article journalistic quality. Data gathered from key messages were assessed for emergent themes that …

Engineer As Writer And Woman: Gender, Identity, And Professional Discourse, Jennfer C. Mallette

Graduate Theses and Dissertations

As students, academics, and professionals, women entering engineering disciplines still encounter barriers that may impede their success. In this environment, what is the role of writing in the development of a professional identity, and how does it function as an avenue or a barrier to professional success? Using an ethnographically-informed case study approach, this dissertation focuses on the experiences of three women--a biological engineering student, an industrial engineering academic researcher, and a civil engineering professional--to examine how these women use writing to construct an engineering identity, take action within their discourse communities, and to demonstrate their technical expertise and ability. …

Evaluation Of Tulane Virus As A Surrogate For The Study Of Human Norovirus, Sabastine Eugene Arthur

Graduate Theses and Dissertations

Among all known causes of acute gastroenteritis, human noroviruses (HuNoV) are the primary cause (68%) of outbreaks and are associated with 78% of illnesses, 46% of hospitalizations, and 86% of deaths. The main obstacle to studying the pathogenesis of HuNoV is the lack of cell culture system and small animal model. Murine norovirus (MNV) and feline calicivirus (FCV) have been utilized as model surrogate viruses to study HuNoV. In this research, a more recent surrogate virus, Tulane virus (TV), was evaluated for physicochemical stability and environmental persistence. The primary goal was to determine the suitability of TV as a surrogate …

Opportunity, Temporal Patterns, And Successful Outcomes Of Far-Right Terrorism Incidents In The United States, Brent Ryan Klein

Graduate Theses and Dissertations

This thesis examines the impact that far-right terrorism opportunity structures and temporal patterns of precursor activity have on incident outcomes. Data from the American Terrorism Study (ATS) are extracted for several attributes of far-right opportunity, in addition to measures for temporal patterns of planning and preparatory behaviors. Bivariate and multivariate findings generally support expectations that target attractiveness and vulnerability, far-right group structures, and patterns of precursor activity are significantly associated with incident outcomes. The paper concludes with suggestions for future research and several implications for homeland security policy.

Landscape Visibility And Prehistoric Artifact Distribution At Pea Ridge National Military Park, Jake Lee Mitchael

Graduate Theses and Dissertations

Pea Ridge National Military Park, in the north east corner of Benton County, Arkansas, is the 4,300 acre site of a crucial Civil War Battle. Human occupation of the Ozark Highland landscape, however, extends far into pre-history. A 2005 report to the National Park Service details the findings of a four year cultural resource survey of the park. The sampling strategy employed in the research design (random sample site selection and 2.5% park coverage) provides an excellent dataset to assess prehistoric land use. This dataset is not dependent on artificially defined sites, representing singular activity in a limited geographical space. …

An Exploratory Study Of Spending Patterns, Obstacles And Traditions Among Same-Sex Marriage Vs Heterosexual Marriage: Who's The Bigger Spender?, Lydia Perritt

Graduate Theses and Dissertations

This study investigated if there was a significant difference in the amount of money spent on same-sex weddings versus heterosexual weddings. The results of this study would assist both the wedding and hospitality industry by providing much needed financial and planning information.

A descriptive, four-section survey was distributed online via Qualtrics utilizing snowball sampling. A total of 152 respondents participated in the study; 84 heterosexual and 68 LGBTQ. The respondents completed the questionnaire that measured wedding traditions, wedding spending, obstacles and challenges faced during their wedding and wedding planning, and demographic information.

The results of this study indicated that same-sex …

Characterization Of Cellulase Enzyme Inhibitors Formed During The Chemical Pretreatments Of Rice Straw, Kalavathy Rajan

Graduate Theses and Dissertations

Production of fuels and chemicals from a renewable and inexpensive resource such as lignocellulosic biomass is a lucrative and sustainable option for the advanced biofuel and bio-based chemical platform. Agricultural residues constitute the bulk of potential feedstock available for cellulosic fuel production. On a global scale, rice straw is the largest source of agricultural residues and is therefore an ideal crop model for biomass deconstruction studies. Lignocellulosic biofuel production involves the processes of biomass conditioning, enzymatic saccharification, microbial fermentation and ethanol distillation, and one of the major factors affecting its techno-economic feasibility is the biomass recalcitrance to enzymatic saccharification. Preconditioning …

Functional Significance Of Gill Claudin Proteins In Rainbow Trout (Oncorhynchus Mykiss) Osmoregulation, Joanna Katarzyna Bujak

Graduate Theses and Dissertations

Claudin proteins, a key element of tight junction complexes, are known to control paracellular permeability. In euryhaline fish, changes in claudin abundance and localization are critical during salinity acclimation. In seawater, a leaky paracellular pathway that facilitates sodium extrusion is hypothesized to be controlled by claudin proteins. The aim of this study was to evaluate the role of Claudin-10c, -10d -10e and Claudin-30 in gill function in freshwater (FW) and seawater (SW) rainbow trout (Oncorhynchus mykiss). I examined mRNA and protein abundance along with cellular localization. A tissue distribution survey showed that all of the claudins studied were predominantly expressed …