Digital Commons Network^™

Phylogenetic Diversity Of The Bacterial Communities In Craft Beer, Lindsey Rodhouse

Graduate Theses and Dissertations

The craft beer industry is increasing in popularity in the United States. The craft brewing process typically does not use a pasteurization step, therefore the boiling process is the primary critical control step. Any microorganisms introduced after boiling, or those that are not killed during boiling, are likely to participate in fermentation and persist in the final product. Previous culture-based studies have isolated bacteria and yeast from craft beers at specific time points, but little research has been done on the process as a whole. The objectives of this research are to (1) track bacteria development throughout the brewing process …

The Parent/Teacher Relationship And The Effectiveness Of The Teaching Important Parenting Skills (Tips) Program For Enhancing Parents' Knowledge About Child Development, Meghan Anderson

Graduate Theses and Dissertations

Parent involvement in education has been highly encouraged because of its strong associations with positive developmental outcomes for children. Teaching Important Parenting Skills: TIPS for Great Kids! (TIPS) is a program in Arkansas that relays research-based information cards to parents through the support network of the teachers. This study examines how effective the TIPS program was in enhancing parent’s knowledge on child development and observes the influence of the parent-teacher relationship. Although no significant correlation was found between the parent/teacher relationship and parent knowledge, a significant correlation was discovered between the parent/teacher relationship and whether parents read the TIPS card …

Characterization Of A Tuberous Sclerosis Complex 2 Variant And Its Interaction Involving The Ras-Related Protein Rheb, Nosaiba Shokr

Graduate Theses and Dissertations

Structure-function relationships of any complex underlie the molecular details of the biological interactions. Rheb, Ras Homology Enriched in Brain, is a Ras-related protein, and it is genetically identified as a molecular switch. Rheb is regulated by cycling between the biologically active GTP and inactive GDP-bound forms. This regulation is partially controlled by an interaction with Tuberous Sclerosis Complex2 (TSC2), a GTPase activating protein (GAP). Upon interaction, TSC2 stimulates Rheb GTP hydrolysis and diminishes the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway is involved in proteins synthesis, cell cycle, and signaling. Mutation in TSC2 causes abnormal activation of Rheb …

Evaluating The Impact Of An All-Vegetable Protein Supplement Containing Fat Emulsifiers And Probiotics On Broiler Performance, Jordan Weil

Graduate Theses and Dissertations

Currently, several niche markets, such as organic and “all natural”, are marketed within the poultry industry. However, little research has been undertaken to determine the cost-effectiveness of poultry diets used to produce chicken within these markets. Specifically, the economics and resulting profits associated with raising chicken with antibiotic-free, all-vegetable (AV) diets are not evaluated. As national chain restaurants such as Chick-fil-A and Panera Bread begin to mandate poultry suppliers raise chicken without antibiotics and use AV diets, it becomes increasingly important to evaluate the economics for integrators. Given the rapidly changing feeding strategies necessary to respond to consumers’ and wholesalers’ …

Natural Air Drying And Storage Of Soybean Seed And Implications On Germination Rates, Vigor, And Oil Quality, Zachary Young

Graduate Theses and Dissertations

Recently introduced technology-comprising cables used for monitoring grain moisture content (MC) and temperature throughout the entire grain mass during drying offers a means to utilize low-temperature natural air-drying for soybean seed. From an electronic monitor and fan control standpoint, the new technology appears to be very promising for managing drying and storage conditions for soybean seed. The objectives for this study were to simulate conditions typically encountered in on-farm, in-bin drying systems and investigate impact of seed cultivar, temperature, moisture content and duration of storage on seed germination rates and vigor (electrical conductivity). In addition this research addresses the problem …

Genome Wide Association And Next Generation Sequencing Approaches To Map Determinants Of Ascites In Broiler Chickens, Shatovisha Dey

Graduate Theses and Dissertations

These studies have investigated different candidate genomic regions for their contributions to ascites in broilers. Ascites syndrome is a manifestation of idiopathic pulmonary arteriole hypertension that concerns the poultry industry worldwide. Investigations have demonstrated the disease to be genetically regulated and to exhibit moderate to high heritabilities. Although previous studies have indicated a few chromosomes to be involved with ascites, no genes have been identified to date with direct links to the disease. This dissertation presents a collection of studies that determine the genomic and genetic interactions for regions on chromosome 2 and 9 for ascites phenotypes in broiler chickens. …

Modeling Ozark Caves With Structure-From-Motion Photogrammetry: An Assessment Of Stand-Alone Photogrammetry For 3-Dimensional Cave Survey, Joseph H. Jordan

Graduate Theses and Dissertations

Nearly all aspects of karst science and management begin with a map. Yet despite this fact, cave survey is largely conducted in the same archaic way that is has been for years - with a compass, tape measure, and a sketchpad. Traditional cave survey can establish accurate survey lines quickly. However, passage walls, ledges, profiles, and cross-sections are time intensive and ultimately rely on the sketcher’s experience at interpretively hand drawing these features between survey stations.

This project endeavors to experiment with photogrammetry as a method of improving on traditional cave survey, while also avoiding some of the major pitfalls …

A Numerical Study Of The Interaction Between One Dimensional Carbyne Chain And Single Stranded Dna, Zeina Salman

Graduate Theses and Dissertations

resolution at the single nucleotide level when developing DNA sequencers. The purpose of this research was to numerically study the electrical properties associated with the interaction between 1D carbon chain, known as carbyne, and ssDNA. First, the electrical properties of the carbyne chain were calculated. Second, the electrical properties of the carbyne chain were calculated in the presence of different ssDNA bases. Analyzing the differences between the two cases led to determining the effects of these different bases on the electrical properties. The numerical simulation approach conducted in this research was based on the first-principle simulation. The first-principle simulation was …

Rna Sequencing In The Development Of Cancer-Cachexia, Thomas Allen Blackwell

Graduate Theses and Dissertations

Introduction: Cancer is a major public health problem in the U.S. and the world. In 2013 there were an estimated 1,660,290 new cases of cancer in the U.S. Cancer-Cachexia (CC) is a common effect of many cancers, and is directly responsible for 20-40% of cancer-related deaths. The mechanisms that control the development of CC are not well understood. Most investigations of CC focus on the post-cachectic state and do not examine the progression of the condition. The purpose of this study was to utilize RNA sequencing to analyze transcriptomic alterations throughout the progression of CC. Methods: Lewis Lung Carcinoma cells …

Experiment-Based Quantitative Modeling For The Antibacterial Activity Of Silver Nanoparticles, Mohammad Aminul Haque

Graduate Theses and Dissertations

Silver (Ag) has been well known for its antimicrobial activity for a long time. Recent research showed the potential of Ag nanoparticles as emerging antimicrobial agents. However, little quantitative analysis has been performed so far to decipher the mechanism of interaction between nanoparticles and bacteria. Here, a detailed analysis based on kinetic growth assay and colony forming unit assay has been carried out to study the antimicrobial effect of Ag nanoparticles against Escherichia coli (E. coli) bacteria. It was observed that the presence of Ag nanoparticles increased the lag time of bacterial growth while not affecting the maximum growth rate …

Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol

Graduate Theses and Dissertations

The discovery of methane in the martian atmosphere via numerous ground- and space-based sources has prompted the study of methanogens as models for life on Mars. Methanogens are microorganisms within the domain Archaea, many of which utilize carbon dioxide (CO2) and hydrogen to produce methane. The non-photosynthetic nature of methanogens indicates that they could exist in sub-surface environments, protected from harmful UV and ionizing radiation on the surface of Mars. These organisms also do not require organics, which are sparse on the planet.

Additionally, the wide variety of environments we find life in on Earth, as well as evidence for …

Instrumental Aspects Of Oxygen Sensing: Quantitation And Recalibration Of A Biofouled Oxygen Sensor, Marlena Patrick

Graduate Theses and Dissertations

In vivo oxygen sensing is a critical area of research for medical applications, such as ischemic stroke, but this important topic is not fully understood or resolved. In addition, the best method for calibration of in vivo sensors is as yet undetermined. For all implantable devices, biofouling, the adsorption of biological material to the device surface, is another significant problem with no clear or well-defined solution. One method employed is to apply a protective polymer membrane to the sensor surface in order to minimize the adsorption of biological material. The work described here investigates two polymers applied to a gold …

The Structural And Functional Properties Of A Double Mutant Of Human Acidic Fibroblast Growth Factor (Hfgf-1), Arwa Mohammed Alghanmi

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1), a member of the FGF superfamily, is a potent mitogen and heparin-binding protein involved in a broad spectrum of biological processes, including angiogenesis, cell proliferation, and wound healing. Design of hFGF-1 with an increased thermal stability and an enhanced cell proliferation activity is highly desired for wound healing applications. Herein, we have designed the variant of FGF-1 by substituting two important amino residues in the heparin-binding pocket. The variant was overexpressed in Escherichia coli and was successfully purified to homogeneity using an affinity chromatographic procedure. Far-UV circular dichroism spectroscopic analysis showed that the …

Using Stable Isotope Geochemistry To Determine Changing Paleohydrology And Diagenetic Alteration In The Late Cretaceous Kaiparowits Formation, Ut Usa, Daigo Yamamura

Graduate Theses and Dissertations

The Western Interior Basin of the North America preserves one of the best sedimentary and paleontological records of the Cretaceous in the world. The Upper Cretaceous Kaiparowits Formation is a rapidly deposited fluvial sequence and preserves one of the most complete terrestrial fossil record of the North America. Such a unique deposit provides an opportunity to investigate the interaction between the physical environment and ecology. In an effort to decipher such interaction, stable isotope composition of cements in sedimentary rocks, concretions and vertebrate fossils were analyzed.

Despite the difference in facies and sedimentary architecture, the isotope composition does not change …

Improvement In Simple Artificial Insemination In Sheep Using Chilled Extended Semen And Consideration Of Fertility In Ewes, Mohan Acharya

Graduate Theses and Dissertations

Three studies were conducted to improve simple artificial insemination in sheep using chilled extended semen and evaluate methods to predict fertility in ewes. The first study evaluated the effect of semen extenders and storage temperature on motility parameters of ram semen stored for up to 72 h. Single semen collected from each ram was divided into four parts and extended using four extenders: milk, TRIS, TEST, and CJ-2, diluted to 600 million sperm/ml and loaded into 0.25 ml straws for storage at 4 and 15° C. Most of the CASA motility parameters were higher after extension and storage at 4 …

Evaluation Of Screening Methods To Detect Heat Stress In Diverse Cotton Genotypes, Mathilda M. Van Der Westhuizen

Graduate Theses and Dissertations

Cotton (Gossypium hirsutum L.) is sensitive to heat stress (HS) during reproductive development. The objective of this study was to evaluate different screening methods for identification of heat tolerance in cotton genotypes. Three growth chamber studies and four field trials were conducted from 2014 to 2017 using genotypes Arkot 9704, VH260, DP 210 B2RF and DP393. Measurements were made of membrane leakage (ML), chlorophyll fluorescence (ChlF), glutathione reductase (GR), and sucrose concentration. In the growth chambers, measurements were made at 30 and 40°C and at 2, 4 and 6 hours of HS, as well as 3 and 7 days after …

Factors Contributing To The Success Of First-Generation College Students At A Research University, Mary Margaret Hui

Graduate Theses and Dissertations

First-generation college students are students whose parents do not have a college degree, and they face numerous barriers in college. Yet, several first-generation college students (FGCS) are successful and are on-track to graduate with a bachelor’s degree in four years. Their success is important because education is associated with increased income, quality of life, and social mobility, making educational attainment even more significant in Arkansas, which has both low educational attainment and high poverty. Little is known about what can be done to close the achievement gap. It is important to analyze what helped FGCS succeed so that higher education …

Noninvasive Measures Of Stress And Lameness In Broilers, Shawna L. Weimer

Graduate Theses and Dissertations

The concept of broiler chicken welfare has evolved from a component of animal husbandry to a label on a chicken product package. Recent attention from the public has led to the need for higher welfare standards for animal production. A primary concern of broiler production is low activity/locomotion attributed to fast growth rates leading to poor leg health. To collect the scientific data necessary to determine conditions providing the best welfare for the bird, multiple methods of assessment are required. Stress is influenced by external (temperature, humidity, lighting, stocking density) and internal (metabolism, thermoregulation, hormonal balance) factors. This series of …

Evaluating The Policies That Lead To Stem Educational Attainment At The University Of Arkansas For Transfer Students, Bryan Hill

Graduate Theses and Dissertations

The US has a critical need to produce more STEM graduates and that need is exponentially more critical in Arkansas. Arkansas currently ranks last in the percent of STEM degrees conferred compared to overall degrees awarded. Students intending to pursue a STEM four-year college degree who start at a two-year college are significantly less likely to succeed in earning that degree. Arkansas passed Acts 672 and 182 aimed at strengthening the success of students who transfer from two-year colleges into four-year institutions. This study sought to evaluate the effectiveness of the Acts by determining if the University of Arkansas (UA) …

Bee Communities On Managed Emergent Wetlands In The Lower Mississippi Alluvial Valley Of Arkansas, Phillip Lee Stephenson

Graduate Theses and Dissertations

Native bee communities that use emergent wetlands are among the least studied systems in bee research. Most native bee species are thought to be in decline based on the loss of usable habitat across the United States. I surveyed emergent wetlands in the lower Mississippi Alluvial Valley of Arkansas during the summers of 2015 and 2016 using pan traps, blue-vane traps, and sweep nets to determine the current status of bee communities in this system. I surveyed 11 sites in 2015 and 17 sites in 2016 and found that bee communities were similar in actively versus passively managed emergent wetlands. …

Understanding N-Nitrosodimethylamine Formation In Water: Chloramine Chemistry, Kinetics, And A Proposed Reaction Pathway, Huong Thu Pham

Graduate Theses and Dissertations

The formation of N-nitrosodimethylamine (NDMA) in drinking water systems is a concern because of its potential carcinogenicity and occurrence at toxicologically relevant levels. The postulated mechanism for NDMA formation involves a substitution between dichloramine and amine-based precursors to form an unsymmetrical dimethylhydrazine (UDMH), which is then oxidized by ground-state molecular oxygen to form NDMA. However, this latter reaction is spin forbidden, thus likely occurs at a slow rate. It is hypothesized that the reaction between monochloramine and hydroxylamine (a nitrification product) may form an intermediate, which is involved in the NDMA formation pathway. This intermediate may also be generated from …

Total N-Nitrosamine Precursor Adsorption With Carbon Nanotubes: Elucidating Controlling Physiochemical Properties And Developing A Size-Resolved Precursor Surrogate, Erin Needham

Graduate Theses and Dissertations

As drinking water sources become increasingly impaired with nutrients and wastewater treatment plant (WWTP) effluent, formation of disinfection byproducts (DBPs) – such as trihalomethanes (THMs), dihaloacetonitriles (DHANs), and N-nitrosamines – during water treatment may also increase. N-nitrosamines may comprise the bulk of the chronic toxicity in treated drinking waters despite forming at low ng/L levels. This research seeks to elucidate physicochemical properties of carbon nanotubes (CNTs) for removal of DBP precursors, with an emphasis on total N-nitrosamines (TONO).

Batch experiments with CNTs were completed to assess adsorption of THM, DHAN, and TONO precursors; physiochemical properties of CNTs were quantified through …

Development Of A Multiband Remote Sensing System For Determination Of Unsaturated Soil Properties, Cyrus D. Garner

Graduate Theses and Dissertations

A multiband system including active microwave sensing and visible-near infrared reflectance spectroscopy was developed to measure unsaturated soil properties in both field and laboratory environments. Remote measurements of soil volumetric water content (θv), soil water matric potential (ψ), and soil index properties (liquid limit [LL], plastic limit [PL], and clay fraction [CF]) were conducted. Field-based measurement of θv was conducted using a ground-based radar system and field measurements within 10 percentage points of measurements acquired with traditional sampling techniques were obtained. Laboratory-based, visible and near infrared spectroscopy was found to be capable of obtaining empirical, soil specific regression functions (partial …

Trihalomethane, Dihaloacetonitrile, And Total N-Nitrosamine Precursor Adsorption By Carbon Nanotubes: The Importance Of Surface Oxides And Pore Volume, Erin Needham

Graduate Theses and Dissertations

As drinking water sources become increasingly impaired, enhanced removal of natural organic matter (NOM) may be required to curb formation of disinfection byproducts (DBPs) upon chlor(am)ination. While carbon nanotubes (CNTs) can adsorb NOM, their properties for DBP precursor adsorption have not been elucidated. Nine types of CNTs were assessed for trihalomethane (THM), dihaloacetonitrile (DHAN), and total N-nitrosamine (TONO) precursor adsorption. Batch isotherm experiments were completed with lake water and, to simulate an impaired condition, effluent from a wastewater treatment plant (WWTP). Adsorption varied with CNT type and dose, with TONO precursors having the highest percent removals from WWTP effluent (up …

Rock Art Management And Landscape Change: Mixed Field Assessment Techniques For Cultural Stone Decay, Kaelin M. Groom

Graduate Theses and Dissertations

As tourism continues to grow as one of the world’s most ubiquitous markets, the development and promotion of non-invasive techniques for cultural stone decay analysis and landscape change are vital to establishing conditional base-lines to best aid cultural heritage management (CRM) efficacy. Using rock art as a medium, this dissertation presents three independent case studies employing the Rock Art Stability Index (RASI) and repeat photography to explore the merits of mixed rapid field assessment techniques in relation to CRM and heritage tourism. While rock art is only one example of irreplaceable world heritage resources, examining how they decay and what …

Spatial Variability Of Seedling Disease Pressure In Cotton Fields, Kyle Douglas Wilson

Graduate Theses and Dissertations

Seedling diseases are important factors in cotton stand establishment, and seedling disease pathogens are widespread in fields in Arkansas. Little is known about the variability of seedling disease pressure within fields. With expanded adoption of site-specific management and other precision agriculture approaches, cotton producers are increasingly interested in predicting seedling disease pressure, particularly in spatially variable fields. The cotton seedling disease pathogens include the soilborne pathogens Thielaviopsis basicola, Rhizoctonia solani, Pythium spp., and Fusarium spp. These pathogens can survive in soil for long periods and, and when the environment is conducive, these pathogens can act individually or in combination to …

Ecological Importance Of Invader Source Population And Disturbance In Aquatic Invasions, Nicole Elizabeth Graham

Graduate Theses and Dissertations

Invasive species are a global problem and their effects on recipient ecosystems may be mediated by disturbance and intraspecific variation. Crayfish can substantially influence stream structure and function, and invasive crayfish often have differential impacts than native crayfish in aquatic ecosystems. Since species traits often vary across a distribution, it is possible that invasive crayfish from different source populations may have distinct impacts on recipient ecosystem structure and function. In the Ozark Highlands of Arkansas and Missouri, USA, invasive O. neglectus (the Ringed Crayfish) may be leading to the displacement of native O. eupunctus (the Coldwater Crayfish). The objective of …

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Graduate Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied …

An Exploration Of The Experience Of Open Awareness Co-Meditation At The Beginning Of Therapy Sessions, Aneeqa Ishtiaq

Graduate Theses and Dissertations

Mindfulness and meditation have been seen as beneficial for mental health and mindfulness-based therapies have proliferated alongside an increase in popular interest in mindfulness (Germer, Siegel, & Fulton, 2013). However, many therapists are unaware of how to add mindfulness-based interventions. It may seem especially ambiguous for therapists and clients unfamiliar with the concept. In this dissertation, the history and current research on mindfulness-based psychotherapy, and its benefits and contraindications, are reviewed, and the researcher’s relationship to the topic is explained. It is identified that one way to add mindfulness to psychotherapy is for the therapist and the client to co-meditate …

Phenology, Habitat Use, And The Impacts Of Wetland Management On Autumn Migrating Rails In Missouri, Auriel M.V. Fournier

Graduate Theses and Dissertations

Rails (Family: Rallidae) are among the least studied birds in North America, in large part due to their elusive nature. As a wetland-dependent species, understanding the timing of their migration and their habitat needs during migration is especially important since management needs to be timed to balance the needs of many species. I developed and verified a new distance sampling based nocturnal ATV spotlight survey because traditional call-broadcast surveys are not effective during autumn migration because of the drop off in call rate after the breeding season. These surveys allow us to ask point-level questions about what habitats rails select …