Life Sciences Commons^™

Molecular Survey For The Honey Bee Trypanosome Parasites Crithidia Mellificae And Lotmaria Passim, Mary-Kate Williams

Graduate Theses and Dissertations

Honey bee populations have been fluctuating within recent years. No one cause has been attributed to colony fluctuations due to the theory that multiple stressors interact with one another to impact colony health. Consequently, microorganisms such as internal parasites of honey bees have been understudied as a contributor to colony health decline.

Molecular diagnostics were utilized to detect the presence of two honey bee trypanosome parasites, Crithidia mellificae and Lotmaria passim, in managed and feral honey bee populations from eight states in the United States (USA). Because studies on trypanosome infections are lacking in the USA, it is important to …

Conformationally-Controlled Late-Stage Modifications For Sar Studies Of The C-3-Glcp Moiety Of Ipomoeassin F, Lucas Whisenhunt

Graduate Theses and Dissertations

The resin glycoside, ipomoeassin F has been shown to be extremely potent against multiple cancer lines (IC50 = 4.2-36 nM). However, the mechanism of action of this potent and complex natural product is still not fully understood. The α,β-unsaturated esters of the glucosyl moiety have been shown to be vital for the overall cytotoxicity of ipomoeassin F. Nevertheless, the importance of the tigloyl ester of the glucosyl moiety is still largely unknown. This work aimed to study the pharmacophore importance of the tigloyl ester by creating, an efficient, scalable, and flexible synthesis route for various analogs. The 18-linear step synthesis …

Effect Of Grain Sorghum Polyphenols On Fecal Fermentation, Danielle Marie Ashley

Graduate Theses and Dissertations

Obesity is an increasing epidemic which during 2015-2016 afflicted 39.8% of adults and 18.5% of youth in the United States. Not only can obesity affect quality of life, but it can lead to life-threatening diseases such as type 2 diabetes, heart disease, stroke, and some cancers. Animal and human research have demonstrated a pattern of gut microbiota perturbation in overweight and obesity, characterized by a reduction of beneficial bacterial species and increase in harmful species. Diet has been established as a contributing factor in gut ecology, and foods including fiber, resistant starch, and polyphenols have been found to both enhance …

Modified Landscapes, Esther Nooner

Graduate Theses and Dissertations

Modified Landscapes is a body of work that reflects serious thought regarding Nature and its future. My personal experience and beliefs are at the core of why I believe this subject to be of great importance and why it will sustain many artists’ investigations for the time to come. The influences that informed this process are explored through experiences I had traveling, reading and exploring the photograph as a material object. The manipulation of the photograph is meant to question the beautiful, untouched scene and break the Romantic gaze that is historically tied to representations of Nature and insist upon …

Sustainable Intensification Of Agriculture: Opportunities And Challenges For Food Security And Agrarian Adaptation To Environmental Change In Bangladesh, Aaron Michael Shew

Graduate Theses and Dissertations

This dissertation investigates three unique aspects of sustainable agricultural intensification (SAI) in the context of Bangladeshi rice production. The first article presents a qualitative analysis of SAI and farmer surveys in the embanked polder region of coastal Bangladesh. The second article investigates the global food security and environmental impacts of already adopted High Yielding Variety (HYV) rice and double-cropped rice systems in Bangladesh using a spatial partial equilibrium trade model and a Life Cycle Assessment (LCA). The final article demonstrates a remote sensing methodology for monitoring dry season rice production at 30 m resolution in Bangladesh using a harmonic time …

Cancer-Induced Muscle Wasting, Jacob Levi Brown

Graduate Theses and Dissertations

Cancer-induced muscle wasting, otherwise known as cancer-cachexia, is a wasting syndrome that occurs in approximately 80% of cancer patients that is the primary cause of death for 22%-30% of cancer cases. Cancer-cachexia may be metabolically induced; therefore, the central hypothesis of this dissertation is mitochondrial degeneration occurs before cancer-cachexia, and increased oxidative stress because of mitochondrial degeneration in muscle may instigate cancer-cachexia. Lewis Lung Carcinoma cells (LLC) or PBS (control) were injected into the hind-flank of C57Bl6/J mice at 8 wks age, and tumor allowed to develop for 1, 2, 3 or 4 wks. Mitochondrial quality, function, ROS emission, protein …

Zinc Injection As A Novel Castration Method And Carry-Over Effects Of Growth-Promoting Implants In Beef Cattle, Jase Joseph Ball

Graduate Theses and Dissertations

In experiment 1, crossbred bull calves (n = 31; body weight (BW) = 114.3 ± 26.3 kg; age = 119 ± 18.4 d) were allocated to treatments by BW and birthdate. Twenty-seven bull calves were allocated to 3 injectable castration treatments (n = 9 calves/injectable castration treatment) to reflect 3 dosage levels of zinc. Intact bulls had greater (P < 0.001) serum testosterone concentrations compared to bulls injected with zinc. In experiment 2, crossbred beef bulls (n = 180) were blocked by initial BW (337 ± 10.9 kg; 6 blocks) and assigned randomly to 1 of 3 treatments on d 0: 1) INJ; received 1 mL (100 mg Zn) of a Zn solution in each testis, 2) BAN; banded, 3) BUL; intact. Final BW was greater (P < 0.01) for INJ (672 kg) and BUL (686 kg) compared to BAN (611 kg). Serum haptoglobin concentration was greater (P < 0.01) in INJ compared to BUL and BAN on d 1, 3, 5, and 7. Zinc injection resulted in sterilization but not castration in feedlot bulls although it was efficacious in castration of young bulls at branding. In experiment 3, crossbred beef steers (n = 106; BW = 96 ± 3.9 kg; age = 74 ± 2.0 d) were blocked by parity of dam (≤ 2 or > 2 parities), stratified by BW, calf age, calf sire, cow BW and body condition score to 1 of 4 treatments: 1) RALG, Ralgro, Ralgro, Revalor XS, at branding (D 0), weaning (D 156), and feedlot processing (D 325), 2) COMP, Component …

Species And Cultural Management Of Earthworms On Golf Course Turf In Arkansas And Oklahoma, Paige Elizabeth Boyle

Graduate Theses and Dissertations

As earthworms feed, they can egest soil and nutrient-rich aggregates (casts) on the soil surface. In low-cut turfgrass systems, such as golf course greens, tees, and fairways, surface casting can result in a muddy playing surface, ball roll issues, weed and pest invasion, reduced aesthetics, surface softening, and reduced photosynthesis. Because the use of pesticides for earthworm control is illegal in the U.S., earthworm casting must be managed through cultural practices. Sand topdressing is one method of earthworm control studied for use on golf courses, with the supposition being that the abrasive sand particles will deter the soft-bodied earthworms from …

Engineering The Structure Of The Human Acidic Fibroblast Growth Factor To Enhance Its Stability And Cell Proliferation Activity, Julie Davis Eberle

Graduate Theses and Dissertations

Human acidic fibroblast growth factor (hFGF1) is a protein well known for its role in cell growth and differentiation. To elicit these cell-signaling processes, hFGF1 non-selectively binds to any one of the seven cell surface hFGF receptor isoforms. Due to its significant involvement in tissue repair activity, hFGF1 is a prime candidate for novel wound healing therapeutics. However, one drawback toward its use as a novel wound healing therapeutic is the poor inherent thermal stability of hFGF1, as it has been found to unfold near physiological temperature. The cause of this instability is strong electrostatic repulsion created by a dense …

Phylogeny And Evolutionary Genomics Of Non-Photosynthetic Diatoms, Anastasiia Onyshchenko

Graduate Theses and Dissertations

Diatoms are prolific photosynthesizers responsible for some 20% of global primary production. In real terms, the oxygen in one of every five breaths traces back to photosynthesis by marine diatoms. Among the tens of thousands of diatom species, a small handful of colorless diatom species in the genus Nitzschia have lost photosynthesis altogether and rely exclusively on extracellular organic carbon for growth. I used DNA sequence data to reconstruct the phylogeny of this group, and found that nonphotosynthetic diatoms are monophyletic, indicating that photosynthesis was lost just one time over the course of some 200 million years of diatom evolution. …

Non-Target-Site Based Tolerance To Herbicides In Amaranthus Palmeri, Reiofeli Algodon Salas-Perez

Graduate Theses and Dissertations

Palmer amaranth, one of the most aggressive and damaging broadleaf weeds in the USA, has evolved resistance to multiple herbicide modes of action. The overall objective of this research was to elucidate the mechanisms by which Palmer amaranth adapt to herbicide selection stress. This research aimed (1) to evaluate the efficacy of fomesafen, glufosinate, glyphosate and trifloxysulfuron to Amaranthus populations; (2) identify candidate genes for endowing tolerance to glufosinate; (3) investigate the involvement of non-target-site resistance (NTSR) mechanism in an ALS-resistant population; and (4) to examine the molecular basis of resistance to PPO inhibitors in Palmer amaranth populations from Arkansas. …

In Vivo Structure-Function Analysis Of Drosophila Robo1, An Axon Guidance Receptor Critical For Midline Repulsive Signaling In The Embryonic Central Nervous System, Haley Brown

Graduate Theses and Dissertations

The repellant ligand Slit and its Roundabout (Robo) family receptors regulate many aspects of axon guidance in bilaterians, including midline crossing of axons during development of the embryonic CNS. Slit proteins are produced by midline cells and signal through Robo receptors expressed on the surface of axonal growth cones to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates.

Drosophila Robo1 has a conserved ectodomain structure of five immunoglobulin-like (Ig) domains plus three fibronectin (FN) repeats. By utilizing a genomic rescue construct …

Examining The Relationship Between State Anxiety And Vestibular And Ocular Motor Impairments And Symptoms In High School Athletes With Concussion, Mallory Kathleen Mcelroy

Graduate Theses and Dissertations

Anxiety has been associated with vestibular and ocular motor impairment in the general population. However, there is limited research regarding the connection between the vestibular and ocular motor systems and anxiety following sport-related concussion (SRC). OBJECTIVE: The purpose of this study is to compare state anxiety between concussed adolescent male and female athletes with and without vestibular and ocular motor impairments and symptoms. DESIGN: Prospective, repeated measures SUBJECTS: Thirty adolescent athletes between the ages of 15-18 years, diagnosed with a SRC completed the STAI-State at initial and medical clearance clinical visit. These adolescent athletes were categorized into vestibular and ocular …

Rapid And Sensitive Detection Of Escherichia Coli O157:H7 Using A Qcm Sensor Based On Aptamers Selected By Whole-Bacterium Selex And A Multivalent Aptamer System, Xiaofan Yu

Graduate Theses and Dissertations

Escherichia coli O157:H7 is one of the top five pathogens contributing to foodborne diseases, causing an estimated 2,138 cases of hospitalization in the US each year. The extremely low infectious dose demands for more rapid and sensitive methods to detect E. coli O157:H7. The objective of this study is to select aptamers specifically binding to E. coli O157:H7 using whole-bacterium SELEX (Systematic Evolution of Ligands by Exponential Enrichment) and to create a multivalent aptamer system by rolling circle amplification (RCA) with the selected aptamer sequence for sensitive detection of E. coli O157:H7 using a quartz crystal microbalance (QCM) sensor. Briefly, …

Determining The Light Requirements Of Various Turfgrass Systems And Investigating Techniques To Quantify Photosynthetically Active Radiation, Travis Russell

Graduate Theses and Dissertations

Light is one of the primary growth-limiting factors of turfgrass. Without sufficient quantities of photosynthetically active radiation (PAR; 400-700 nm wavelength), turfgrass quality will decline and could ultimately result in plant death. PAR light can be expressed in a daily quantity known as the daily light integral (DLI) and has been utilized to determine minimum light requirements for turfgrass as well as other plants. With an estimated 25% of all turfgrass being maintained under some level of shaded conditions, it is imperative to define minimum DLI requirements of various turfgrass systems to ensure acceptable turf quality. In addition, it is …

The Comparison Of Using The Preferred Or Non-Preferred Wrist When Measuring Physical Activity In College Students, Bryce Daniels

Graduate Theses and Dissertations

Introduction. People who participate in regular physical activity have a decreased risk of chronic diseases and premature death. A dramatic decrease of physical activity occurs from adolescence to young adulthood. With important implications to health, physical activity is an important behavior to measure. However, inconsistencies exist on how to measure physical activity. When using accelerometers, differences between the preferred or non-preferred wrist may result in different estimates of physical activity. Purpose. The purpose of this study was to compare the preferred and non-preferred wrist accelerometry measured physical activity using commonly used research accelerometers during structured daily college activities (Actigraph GT3x-bt …

Disordered Eating Risk And Body Image Dissatisfaction Of Division I Male And Female Cheerleaders, Christopher Blaszka

Graduate Theses and Dissertations

The sport of cheerleading is growing both in the high school and college setting, however there is little research on cheerleaders specifically, both sideline and competitive. It is clear that while this sport does not benefit from being affiliated with the NCAA, the athletes are still at large risk for disordered eating and eating disorders, and are in need of more accurate screening and prevention methods. With the lack of cheerleading studies in general, there is an even larger scarcity of studies that focus on males in cheerleading. The current study aims to fill the gap in the research regarding …

Preservice Agricultural Education Teachers And Secondary Education Teachers’ Self-Efficacy And Professional Identity, Hailey Gates

Graduate Theses and Dissertations

During the nineteenth century, a decision was made to separate the preparation of agricultural education teachers from their elementary and secondary counterparts (Hearings, 1908; Heren & Hillison, 1996; Hillison, 1986). The majority of land-grant universities and colleges have continued to prepare agricultural education preservice teachers within the college of agriculture, separate from other secondary education preservice teachers in the college of education (Myers & Dyer, 2004). Despite the differences among content disciplines, teachers who possess a strong sense of self-efficacy and professional identity have higher success rates in the classroom when it comes to collaboration, involvement, and student achievement (Ashton …

Irrigation Practice Adoption: Causes And Consequences In The Arkansas Delta, Kerr James Adams

Graduate Theses and Dissertations

Concerns about groundwater depletion from conventional irrigation agriculture in the Arkansas Delta region have led to the promotion of more efficient irrigation practices. With Arkansas being the largest producer of rice, the 10th largest producer of soybeans and the 16th largest producer of corn in the United States, the irrigation demand of these crops has put pressure on producers to find ways to irrigate more efficiently. Not only are the alternative technologies supposed to reduce water use, it is also believed that their adoption can also yield economic benefits for the producer. Despite these assumed benefits, adoption of alternative technologies …

Dicamba Effects On Soybean (Glycine Max) Growth, Yield, And Offspring, Mark Spencer Mccown

Graduate Theses and Dissertations

Introduction of a new dicamba-resistant (Xtend) trait in soybean and cotton will increase dicamba herbicide use. Consequently, concern for injury to sensitive crops from off-target movement and tank contamination will likely increase. For soybean, foliar symptoms associated with dicamba damage do not necessarily reflect yield losses; hence, experiments were conducted to determine the effects of dicamba on soybean growth, yield, and offspring. Low rates of dicamba [1/64X (8.75 g ae ha-1) and 1/256X (2.18 g ae ha-1) of a normal 1X field rate (560 g ae ha-1)] were applied at two vegetative growth stages (V4, V6) and at each reproductive …

A Genome Wide Association Study For Fusarium Head Blight Resistance In Southern Soft Red Winter Wheat, Amanda Holder

Graduate Theses and Dissertations

Fusarium head blight (FHB) is a disease of small grains caused by the fungal pathogen Fusarium graminearum. FHB poses potential economic losses and health risks due to the accumulation of the mycotoxin deoxynivalenol (DON) on infected seed heads. The objectives of this study are: 1) evaluate soft red winter wheat (SRWW) lines for resistance to FHB in terms of resistance to initial inoculum (incidence); resistance to spread within the head (severity); resistance to DON accumulation; and resistance to Fusarium damaged kernels (FDK), 2) determine the frequency and effect of known FHB resistance genes and quantitative trait loci (QTL), and 3) …

Microbiome Of Commercial Broilers Through Evisceration And Immersion Chilling, John A. Handley

Graduate Theses and Dissertations

The United States poultry industry generated 38.6 billion pounds (17,500 metric ton) of meat in 2014 which averaged to 121 pounds (55 kg) per individual of the U.S that same year. Of that meat generated by the poultry industry, an estimated 1 million cases of Salmonellosis will occur. Out of the 1 million cases approximately 40, 000 to 50,000 will be confirmed cases by the CDC. Recently, the USDA has requested changes in the inspection process and are currently allowing processors more freedom to utilize innovation to drive the increase in safer and more desirable foods. The new standards set …

Unravelling The Layers Of Cell Wall Synthesis And Function In Rice, Ritu Mihani

Graduate Theses and Dissertations

The plant cell wall is of critical importance to plant growth and survival, functioning in maintaining structural integrity, supporting cell expansion, and acting as the first line of defense in response to biotic and abiotic stresses. The major components of the cell wall are cellulose, hemicelluloses, lignin, and pectin. Recent focus on the transcriptional machinery regulating cell wall biosynthesis in plants has revealed many key transcription factors responsible for orchestrating cell wall deposition. However, many of these TFs act redundantly and work coherently with a suite of TFs to activate the cell wall biosynthetic machinery. Heterologous expression of TFs is …

Combining Translational And Functional Genomic Approaches To Augment Management Strategies Of Plant Parasitic Nematodes, Sandeep Sharma Khatiwada

Graduate Theses and Dissertations

Plant-parasitic nematodes pose a major threat to crop yield worldwide. Discontinued use of harmful chemicals has prompted the search for alternative management strategies that are effective yet environmentally friendly. Harpin proteins, which are derived from bacteria, and nematophagous fungi, natural predators of nematodes, are ideal for biological control of plant-parasitic nematodes. However, research on the efficacy of harpin proteins on nematodes, and biology of nematophagous fungi is minimal. Previously, a taxonomically uncharacterized nematophagous fungus designated ARF18 effectively suppressed nematode populations in soil. The overarching goal of this dissertation is to utilize applied and functional genomic approaches to augment management of …

Consumers’ Willingness To Pay For Hydroponic Lettuce, Daniel Gilmour

Graduate Theses and Dissertations

With continued advances in hydroponic plant production technology, an increasing number of farms have begun using hydroponic techniques to grow leaf lettuce and other food crops in a controlled environment. Recent controversy about the ongoing inclusion of hydroponics in the USDA organic program has highlighted uncertainty about marketing for hydroponic crops. In November 2017, the National Organic Standards Board voted not to recommend that hydroponic farms be banned from applying for organic certification. Since then, continued controversy has led a group of organic producers to start an additional independent certification program that would exclude hydroponic crops. While hydroponic production may …

Multiscale Investigation Of The Behavior Of Heart Valve Interstitial Cells In Response To Pathological Shape And Mechanical Stimulation, Ngoc Thien Lam

Graduate Theses and Dissertations

Our works aim to provide an insight into how aortic valve interstitial cells (VICs) respond to pathological shape and mechanical stimulation as well as the potential signaling pathway that mediates these responses, using a multiscale approach. A single cell model was developed to investigate the effect of altered shape on valve cell function as valve cells were reported to significantly deform during the cardiac cycle. Single VICs were controlled to take on features with different width-to-length aspect ratios that corresponded to the steady-state shapes adopted by VICs when stretched to 0%, 10% and 20%, respectively. It appeared that single VIC …

An Impact Evaluation Of The Government Grant Programs And Input Efficiency Use In The Production Of Greenhouse Tomatoes And Peppers In Kosovo, Blend Frangu

Graduate Theses and Dissertations

Determinants of greenhouse tomato and pepper production input efficiency affect a farmer’s decision to contribute to the vegetable sector in Kosovo. This research investigates the non-optimal use of inputs in the production of greenhouse tomatoes and peppers. Two studies were conducted to first measure input efficiency use and then to quantify the impact of the Ministry of Agriculture, Forestry and Rural Development (MAFRD) grant programs in the production of both crops. The first study applied data envelopment analysis (DEA), and linear and logistic regression to assess factors that influence efficiency in production. The second study used propensity score matching with …

Genetic And Phytopathological Studies On Charcoal Rot Resistance In Soybean [Glycine Max (L) Merr.], Marcos Paulo Da Silva

Graduate Theses and Dissertations

Charcoal rot of soybean (Glycine max (L.), caused by Macrophomina phaseolina is a disease of economic significance in the United States. The identification and quantification of the resistance is difficult, and very little is known about the genetics and markers linked to the charcoal rot (CR) resistance genes. Current assay methods can be time consuming, and data may vary between tests. The objectives of this study were to 1) create a robust seed plate assay (SPA) for CR resistance by comparing results with cut-stem and CFUI assays; 2) correlate and compare field data disease assessments with SPA; 3) identify QTLs …

Involvement Of The Ino80 Complex In Chromosome Segregation, Jesus Moreno

Graduate Theses and Dissertations

Chromatin remodeling complexes are multi-protein complexes that regulate the dynamics of the nucleosomes in the genome. The INO80 chromatin remodeling complex participates in varied biological processes such as: transcription, DNA repair, DNA replication and chromosome integrity. It catalyzes the eviction of the H2A.Z variant histone as well as whole nucleosome eviction. This complex is comprised of 15 subunits and the contribution of each to chromosome segregations remains unknown. To evaluate the contribution of each subunit to chromosome segregation, we tested deletion mutants of the non-essential subunits for DNA content and benomyl sensitivity. Also, we assessed members of the SWR1 and …

Using Covers And Wetting Agents To Prevent Winter Injury Of Ultradwarf Bermudagrass, Eric Deboer

Graduate Theses and Dissertations

As ultradwarf bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) putting green use in the United States moves further north, there is risk of sustaining winter injury from low-temperature exposure and tissue desiccation. Protective covers reduce low-temperature exposure on ultradwarf bermudagrass greens. Desiccation of turf can be caused by hydrophobic soils. Wetting agents are applied to actively growing ultradwarf bermudagrass greens to relieve symptoms of hydrophobic soils. Less is known about the effects late-fall wetting agent applications on dormant bermudagrass putting greens. This research aims to define a predicted low-temperature threshold for covering ultradwarf bermudagrass greens and to quantify …