Digital Commons Network^™

The Energy Yield Of Global Crops 1961-2016, Quinn Montana

Graduate Theses and Dissertations

It is often suggested that world food production must increase by 70%-100% or more by the year 2050 if we are to feed the anticipated world population at that time. To evaluate this claim, global crop production from 1961 to 2016 was inventoried using publicly available data from the United Nations Food and Agriculture Organization (FAO). To determine the adequacy of global crop output for humanity, annual global food crop production data (T y-1) were converted to energy yield in kilojoules (KJ y-1). These data were then compared to the annual metabolic energy requirement of the global human population. The …

Effect Of Morinda Citrifolia (Noni)-Enriched Diet On Hepatic Heat Shock Protein And Lipid Metabolism-Related Genes In Heat Stressed Broiler Chickens, Joshua Flees

Graduate Theses and Dissertations

Heat stress (HS) has been reported to alter fat deposition in broilers, however the underlying molecular mechanisms are not well-defined; therefore, the objectives of the current study were to: (1) determine the effects of acute (2 h) and chronic (3 wk) HS on the expression of key molecular signatures involved in hepatic lipogenic and lipolytic programs; and (2) assess if diet supplementation with dried Noni medicinal plant (0.2% of the diet) modulates these effects. Broilers (n=480 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to two environmental conditions (HS at 35°C vs. thermoneutral condition [TN] at 24°C) …

Design Of Peptoid-Based Coating To Reduce Biofouling In Gas Exchange Devices, Neda Mahmoudi

Graduate Theses and Dissertations

In recent decades, membrane technology has been used commonly in biomedical area. However, membrane fouling is a widespread problem in different applications. One method to minimize fouling is through surface modification of membranes. My research explores a novel polymer to minimize nonspecific protein adsorption in biomedical applications.

It firstly focuses on grafting the electrically neutral NMEG peptoid, containing 2-methoxyethyl side chains, to polysulfone (PSU) membrane via polydopamine. Contact angle measurements indicated that the hydrophilicity of the peptoid-grafted membranes was significantly improved while the pore size and strength of the membranes remained unchanged. The modified membranes showed an improved fouling resistance …

Effect Of Yeast Supplementation During Various Stages Of Beef Production, Elizabeth Palmer

Graduate Theses and Dissertations

Supplemental dietary yeast products are beneficial during times of stress. Calves experience increased levels of stress during birth, weaning, and the post-weaning receiving period. Therefore, 3 experiments were conducted to determine how yeast supplementation affects growth performance and health during this time. In experiment 1, 2 truckloads of highly stressed calves (n = 175; initial body weight [BW] = 226 ± 24.5 kg) were assigned randomly to 1 of 3 treatments; unsupplemented control, or supplementation with 2 commercial yeast products (Y1 and Y2). Average daily gain (ADG) was not different (P = 0.99) during the 28 d receiving period; nor …

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 …

Effects Of Serving Temperature On Sensory Perception And Acceptance Of Brewed Coffee, Matthew James Chapko

Graduate Theses and Dissertations

Coffee continues to be one of the most widely consumed beverages worldwide. How an individual perceives a cup of coffee is impacted by a plethora of factors including origin, growing climate, roasting level, and consumption habits. This thesis utilized both trained descriptive panelists and untrained consumer panelists to analyze how serving/consumption temperature modulates sensory perception of brewed coffee in regards to appearance, aroma, flavor, taste, and mouthfeel. Three varieties of coffee (Colombia, Ethiopia, and Kenya) were brewed and served to panelists at four temperatures: 70, 55, 40, and 25 °C. In one study (Study 1, Chapter 3), results from descriptive …

Association Mapping And Genomic Selection For Yield And Agronomic Traits In Soft Winter Wheat, Dennis Bulusan Lozada

Graduate Theses and Dissertations

Tools such as genome-wide association study (GWAS) and genomic selection (GS) have expedited the development of crops with improved genetic potential. While GWAS aims to identify significant markers associated with a trait of interest, the goal of GS is to utilize all marker effects to predict the performance of new breeding lines prior to testing. A GWAS for grain yield (GY), yield components, and agronomic traits was conducted using a diverse panel of 239 soft winter wheat (SWW) lines evaluated in eight site-years in Arkansas and Oklahoma. Broad sense heritability of GY (H2=0.48) was moderate compared to other traits including …

Effect Of Sensory Stimulation In Physical Activity On Academic Achievement And Classroom Behavior In Elementary Students, Maryann Mitts

Graduate Theses and Dissertations

Technological advancements and increased screen time has increased sedentary activity and altered the brain development of children. With the reduction of PE and recess in schools, increasing sensory stimulating physical activity can be pivotal in cognitive and behavioral development. Activities such as rolling and spinning enhance the sensory system in organizing and filtering information efficiently for quicker and more appropriate responses to stimuli. This study investigated the effect sensory stimulation had on auditory memory, reading levels and behaviors of elementary students.

During a 6-week period, 176 students, grades 1-5, participated in the sensory maze Minds in Motion, 15 sensory activities …

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 …

A Numerical Investigation Of Bio-Inspired Scaffolds And Surface Textures, Yucong Gu

Graduate Theses and Dissertations

Synthetic scaffolds are widely used as implants to repair bone fracture. Without a proper design, scaffolds could pose significant health risks to the patient and fail to heal the bone properly. A good synthetic scaffold needs to have high porosity and large pore size to allow new bone cells to form on it. However, a scaffold with higher porosity and larger pore size tends to have reduced mechanical strength. Thus, it is important to find a structural design which allows the implant to have a high porosity and large pore size while retaining high strength. In this research, a 3D-printable …

Got Breadfruit? Marshallese Foodways And Culture In Springdale, Arkansas, Diana Kay Chen

Graduate Theses and Dissertations

Understanding human food choices is essential in the examination of cultural knowledge and decision-making among members of any ethnic group. Ethnographic and cognitive anthropology methods, including a novel calculation of cognitive salience, were used in this study to explore the domain of traditional Marshallese foods in Springdale, Arkansas. Springdale is home to the highest population of Marshallese people outside of the Republic of the Marshall Islands (RMI); the population is expected to rise as people continue to migrate from the RMI because of global climate change and other factors such as family ties. Studies of traditional foodways are increasingly crucial …

Milk, Lindsey Heiden

Graduate Theses and Dissertations

My work is a composition of contemporary fairy tales of visual, written and oral forms. I examined the historical evolution of formula, from animal milk, to powder formula and now to a combination of animal milk, human milk and powder. The current scientific research being done with formula and animals, coupled with a fairy tale is the inspiration behind my current tale. The importance of women both in regards to the historical development of keeping a cultural tradition alive through oral tale-telling and the much larger role of keeping humankind alive through reproduction and birth, further build the base that …

For Wintonbury: An Expansion Of Narrative And Painting, Cassaundra Kayla Sanderson

Graduate Theses and Dissertations

In March 2017, I began planning the narratives of what would become my Thesis Exhibition. One year later marked my installation of the exhibit: For Wintonbury, located at the Fine Art Center Gallery at the University of Arkansas.

A merging of the visual arts and literary fiction, For Wintonbury offers a more immersive experience in storytelling. The painted scenes, drawings, three-dimensional compositions, and short stories each serve their own purposes in presenting partial glimpses into the longer narratives of Wintonbury. Through multiple media and entry points, the viewer is given the choice in which sequence and manner to take in …

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 …

Interpersonal And Ideological Kindness: A Biocultural Approach, Sally Averitt-Hubbard

Graduate Theses and Dissertations

In accordance with Richard Dawkins’ materialist “selfish gene” theory of human behavior, altruism is a subject matter that is treated conservatively by biologists, whose understanding of the human version of altruism tends toward mutualistic and sometimes reputation-based explanations of charity, kindness, and helping. Trivers (1971) first stated that non-kin altruism could evolve if altruistic behavior is balanced between partners over time, implicating a strictly mutualistic domain for kindness. But kindness herein is defined, beyond mere mutualism or reciprocity, as “the quality of being friendly, generous, and considerate.” Further, kindness tends to have an action-oriented dimension, as in Goetz et al.’s …

Costume Design For Adam Rapp’S The Metal Children At The University Of Arkansas, Melissa Janet Hall

Graduate Theses and Dissertations

The following thesis explains the process utilized to create and implement the costume design for the production of The Metal Children produced at the University of Arkansas University Theatre in the Fall of 2016. Throughout this thesis I will illustrate how the costumes went from initial research ideas to sketches and colored renderings and finally to finished three-dimensional costumes. The design process detailed here includes an analysis of the play, inspiration collage, portrait gallery, research, renderings, production images and an evaluation of the overall process.

The Effects Of Super-Dosing Phytase On Nursery And Grower Pigs, Joshua Paul Knapp

Graduate Theses and Dissertations

To determine the effects of super-dosing on pigs fed phosphorous and calcium adequate or deficient diets (Experiment 1); the optimum level of corn express phytase (CEP, Experiment 2); and the effects of xylanase/phytase on growth performance (Experiment 3) in pigs fed reduce nutrient diets, weaned pigs were blocked with initial body weight (BW) and allotted to dietary treatments. Treatments were: Positive control (PC), P/Ca adequate diets (NRC 2012); Negative Control (NC), low P (-0.15%) and Ca (-0.12%), +0, 1000, and 4000 FTU/kg of CEP in both PC and NC (Experiment 1); PC, P/Ca adequate diets; NC, decreased P (0.15%) and …

Ham Radio Operator, Zachary Michael Hester

Graduate Theses and Dissertations

Ham Radio Operator is a collection of poems.

State Dependent Function And Dynamics In Cerebral Cortical Networks, Leila Fakhraei

Graduate Theses and Dissertations

Cerebral cortex exhibits vigorous ongoing, internal neural activity even with no sensory input is present or the animal is minimally engaged in a task or behavior. This internal ongoing activity is not static; the ‘cortical state’ varies ranging from synchronous and highly correlated activity to asynchronous and weakly correlated neural activity. The main goal of the work presented here is to understand how changes in cortical states effect several aspects of cortical function and dynamics.

To meet this goal, we did three separate projects. First, we compared the predictability of neuronal network dynamics across cortical states in somatosensory cortex of …

Translation Of View From The Ossuary By Antoine Volodine, John Thomas Mahany

Graduate Theses and Dissertations

This is a literary translation from the French of Antoine Volodine’s Vue sur l’ossuaire. Additional creative embellishments have been included in the form of translator’s notes and epigraphs in order to enhance the fictive reality of the work.

Pynchon And Place: A Geocritical Reading Of Thomas Pynchon, John Stout

Graduate Theses and Dissertations

A special emphasis on artificial or constructed spaces appears throughout Thomas Pynchon’s body of work. This thesis explores how Pynchon describes such spaces and their uses to address such weighty topics as social inequity and the struggle against authoritarianism. In examining the role of sheltering spaces in novels such as V. and Gravity’s Rainbow, I argue that Pynchon depicts various “outsider” characters as finding reification of their own forms of alterity within spaces either designed or co-opted with such purpose in mind. Through Pynchon’s depiction of spatial transformation in novels like Vineland and Inherent Vice, the author finds the opportunity …

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 …

Antiproliferative Activity Of Carotenoids, Phenolic Compounds, And Volatile Terpenoids In Carrots (Daucus Carota L.), Brittany Frederick

Graduate Theses and Dissertations

Epidemiological studies have shown an association between high carrot consumption and low prevalence of cancer. This observation has been thought to be attributed to carrot carotenoids. Despite this, various intervention trials have displayed no changes in incidence or increased incidence of cancer with carotenoid supplementation. It is possible that carrot phenolics are responsible for this association, though this has not been widely accepted. Volatile terpenoids from carrots have not been studied in this regard. Therefore, the primary objective of this study was to compare the antiproliferative effects of carotenoids, phenolics, and volatile terpenoids extracted from carrots on Caco-2 colon cancer …

A Proposed Approach To Hybrid Software-Hardware Application Design For Enhanced Application Performance, Alex Shipman

Graduate Theses and Dissertations

One important aspect of many commercial computer systems is their performance; therefore, system designers seek to improve the performance next-generation systems with respect to previous generations. This could mean improved computational performance, reduced power consumption leading to better battery life in mobile devices, smaller form factors, or improvements in many areas. In terms of increased system speed and computation performance, processor manufacturers have been able to increase the clock frequency of processors up to a point, but now it is more common to seek performance gains through increased parallelism (such as a processor having more processor cores on a single …

Examining The Appropriate Recovery Interval Following Maximal Exertion For Baseline Computerized Neurocognitive Testing (Cnt), Samantha Mohler

Graduate Theses and Dissertations

Background: Computerized neurocognitive testing is part of the recommended multi-faceted approach to SRC assessment. Prior research has suggested that maximal exertion negatively effects CNT test scores. Purpose: To identify the appropriate timing of the administration of CNT following maximal exertion in healthy college-aged students. Study Design: Random cross-over, repeated measures design. Methods: Participants will be administered CNT on four different visits, with at least one week between administrations. A VO2 max treadmill test will be performed before CNT administration during three of the four trials. Following the VO2 max test, participants will rest for <2 minutes (immediate), 10-minutes, or 20-minutes before taking CNT. The fourth trial, without maximal exertion preceding CNT administration, will serve as the control. All trials will be randomly-counterbalanced to negate practice effects. RESULTS: There was a significant within-subjects effect for prescribed post-exertion recovery intervals on total symptom scores (Wilks λ = .62, F [3, 23] = 4.64, p = .01, η2= .38). Total symptom scores were significantly higher at the immediate (p < .002), 10-minutes (p = .018), and 20-minutes (p = .011) post-exertion recovery intervals compared to baseline. Additionally, a significantly positive within-subjects effect for prescribed post exertion recovery was observed for processing speed (p=.009, Wilks λ = .60, F [3, 27] = 5.9, η2 = .396). No significant effect was observed for visual memory (p = .07), verbal memory (p = .06), or reaction time (p = .40). CONCLUSION: Baseline symptom scores were negatively influenced processing speed was enhanced by maximal exertion. These changes continue to be elevated 20 minutes post-exertion. Moreover, cognitive performance was not significantly impaired following maximal exercise. To obtain more accurate baseline symptom scores, and allow processing speed composites to return to normal, sports medicine professionals should wait at least 20 minutes following maximal exertion before administering CNT.

A Flourynge Aege: Tracing The Sacred And Secular In The Book Of St. Albans, Allison Treese

Graduate Theses and Dissertations

With the introduction of the printing press to England around the mid-fifteenth century, English authors were not only writing under the lingering influence of Chaucer and the conventions of established medieval genres, but now had to confront the implications for reading and readership that printing brought with it along with the already turbulent political climate of the fifteenth century. Though this cultural shift was arguably a gradual one, with the earliest printers taking special care to remain faithful to the manuscripts they were copying, and conventional scribes likewise being commissioned to make copies of printed works, there were nevertheless radical …

Factors Affecting The Longevity Of Individual Terrorists, Madeline Brice

Graduate Theses and Dissertations

The purpose of this study is to examine factors that affect the longevity of individual terrorists. Previous studies on terrorist group longevity have focused on the decisions terrorist groups have made rather than focusing on factors that help individuals evade capture. Literature also suggests that terrorists that manage to stay active may be able to use this as a valuable recruiting tool. This project examines six different relationships with longevity, including Attorney General (AG) Guidelines, demographics, ideology, level of participation, number of activities, and sophistication of attack. To examine these relationships, data will be used from the American Terrorism Study …

Experimental And Model-Based Terahertz Imaging And Spectroscopy For Mice, Human, And Phantom Breast Cancer Tissues, Tyler Bowman

Graduate Theses and Dissertations

The goal of this work is to investigate terahertz technology for assessing the surgical margins of breast tumors through electromagnetic modeling and terahertz experiments. The measurements were conducted using a pulsed terahertz system that provides time and frequency domain signals. Three types of breast tissues were investigated in this work. The first was formalin-fixed, paraffin-embedded tissues from human infiltrating ductal and lobular carcinomas. The second was human tumors excised within 24-hours of lumpectomy or mastectomy surgeries. The third was xenograft and transgenic mice breast cancer tumors grown in a controlled laboratory environment to achieve more data for statistical analysis.

Experimental …

Development Of Microdialysis Probes In Series Approach Toward Eliminating Microdialysis Sampling Calibration: Miniaturization Into A Pdms Microfluidic Device, Randy Espinal Cabrera

Graduate Theses and Dissertations

A new microdialysis sampling method and microfluidic device were developed in vitro. The method consisted of using up to four microdialysis sampling probes connected in series to evaluate the relative recovery (RR) of different model solutes methyl orange, fluorescein isothiocyanate (FITC)-dextran average mol. wt. 4,000 (FITC-4), FITC-10, FITC-20, and FITC-40. Different flow rates (0.8, 1.0, and 1.5 µL/min) were used to compare experimentally observed relative recoveries with theoretical estimations. With increasing the number of probes in series, the relative recovery increases and ~100% (99.7% ± 0.9%) relative recovery for methyl orange was obtained. For larger molecules such as fluorescein isothiocyanate …