Digital Commons Network^™

Effects Of Seasonal Environment On Abundance, Behavior, Visual Signaling, And Perception In Prairie Butterflies, Grace Elizabeth Hirzel

Graduate Theses and Dissertations

Phenotypic plasticity is a widespread mechanism that allows animals to respond quickly to seasonal changes in their environment. However, the depth and complexity of these plastic responses is still being discovered. One aspect of seasonal physiology that is relatively unstudied is changes to sensory physiology and how it may explain changes in behavior. To determine how changes in seasonal conditions affect behavior, coloration, and vision, I examined populations of wild butterflies in Northwest Arkansas. Focusing on a single species, the common buckeye Junonia coenia, I found that seasonal coloration covaries with thermoregulating behavior and is accompanied by changes in visual …

Impact Of Reducing Ammonia Concentration By Ozone Technology And Its Potential Improvement On Broiler Performance, Odilpio Quintana Ortega

Graduate Theses and Dissertations

The employment of ozone in livestock production as a means of mitigating ammonia is used for enhancing air quality within animal confinement facilities, such as swine or poultry barns. Ammonia is a byproduct of animal excrement. Elevated ammonia concentrations can adversely affect the well-being of both animals and humans. The aim of this thesis was to investigate the effects of Ozone Technology Machine Unit (OTMU) utilization in poultry barns regarding ammonia concentration and its potential benefit in terms of broilers performance and welfare. In recent years, there has been a significant boom in technological advances. New devices that help mitigate …

Geochemistry Of Metal-Rich Black Shales And Their Genetic Relationship To Mississippi Valley-Type Pb-Zn Ore Deposits, Midcontinent U.S., Noah S. Morris

Graduate Theses and Dissertations

The formation of Mississippi Valley-type (MVT) lead-zinc (Pb-Zn) ores is complex, involving an interaction of tectonic compression, hydrothermal fluid migration, and geochemical processes within the subsurface. Fundamental questions regarding this interaction remain unclear, including the source(s) of the Pb and Zn ions that make up the ores. A genetic link between black shales and MVT ores has been thought to exist because of (1) the presence of mature hydrocarbon and brine fluid inclusions within many MVT ores, (2) the association of the hydrothermal fluids that are linked to MVT ore formation with organic compounds and oil-like droplets, and (3) the …

A Generic Qualitative Inquiry Of The Challenges For Black African American Men Who Have Experienced Trauma, Randall Lee Maurice Shakir

Graduate Theses and Dissertations

Black African American Men (BAAM) suffer disproportionately from trauma related challenges and have a higher risk of encountering trauma across the lifespan. The negative impact of trauma is a major public health concern in the United States, evidence suggests trauma negatively impacts the physical well-being, mental health, and mortality rate. BAAM have increased rates of trauma exposure and their traumatic experience is historically complex involving a variety of contemporary issues (i.e. Adverse Childhood Experiences (ACEs), depression, victimization and desensitization, stress). This research aims to explore the complex nature of their trauma-related challenges among a purposeful sample of BAAM participants in …

Social Media And Mental Health: The Public Health Impact And Future Policy Directives, Renae A. Merrill

Graduate Theses and Dissertations

The relationship between social media use among young people and the increasing concerns of mental health problems in the U.S. and globally is on systemic agendas. Furthermore, research on social media use and mental health indicate reasons to suspect a causal relationship, but more work needs to be done. Therefore, this three-article dissertation seeks to explore (1) associations between social media use, personality, and depression; (2) associations between social media emotional support, anxiety, and personality; and (3) the relationship between social media use and mental health using Deborah Stone’s causal stories framework. Findings from this study provide an improved understanding …

Geospatial Analysis Of Weathering And Recession On Architectural Limestone At The 1891 Powerhouse/Icehouse In Eureka Springs, Arkansas, Stuart Bruce Wright

Graduate Theses and Dissertations

The objective of this study of the architectural limestone of the 1891 Powerhouse/Icehouse in Eureka Springs, Arkansas was to analyze the environmental factors that influenced the deterioration and surface recession of this historical stone structure. The focus of this research was to examine and establish a baseline study that may assist in future monitoring and documentation of this historic limestone structure on stone weathering. A replicable methodology was specifically created toward this baseline research in hopes that it represented a solid baseline study. Observations and data analyses revealed the relationship between the architectural limestone building structure and the dominating recession …

A Muscle Exercise Research Revolution Powered By -Omics At Single Cell And Nucleus Resolution, Kevin A. Murach, Charlotte Peterson

Health, Human Performance and Recreation Faculty Publications and Presentations

In the last few years, single cell and single nucleus RNA-sequencing technologies have been leveraged in exercised adult skeletal muscle to reveal complex cell type-specific regulation of muscle plasticity. Expanding -omics technology at single cell resolution, complimented by advanced computational approaches, promise to rapidly accelerate our understanding of how exercise confers its numerous beneficial effects, paving the way for cell type-specific and targeted therapeutics to increase exercise responses during aging and in the face of chronic disease.

3d Printed Microdialysis-Based Microsampling Probes, Patrick Pysz

Graduate Theses and Dissertations

This work will show the development of a fully 3D printed device platform in which a complex microsampling probe geometry is fabricated in a simple two-step process. This process includes the combination of 2-photon polymerization (2PP) and masked-stereolithography (MSLA). The cutting edge neurotechnology needed to monitor brain internal communication and will require multiple sensing modalities including temperature, pressure, electrophysiological, and optogenetics. Microsampling is an integrally important function for any future biosensing device platform as it allows for chemical delivery and unparalleled specificity through offline analysis of collection samples. Stereolithography (SLA) 3D printing has emerged as a powerful fabrication method capable …

Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton

Graduate Theses and Dissertations

Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need …

Management Zone Delineation For Variable-Rate Seeding In Production Soybeans, Ujjwal Sigdel

Graduate Theses and Dissertations

Soybean seeding rate (SR) is selected according to planting date, maturity group, soil properties, and yield goal. Even though one SR is applied in most fields, site-specific adjustments with variable-rate seeding (VRS) technology can help optimize production. The project goal was to determine if VRS could be beneficial to soybean producers in Arkansas. The project objectives were to i) assess planter performance and soybean yield response to five seeding rate treatments, ii) characterize the drivers of yield variability, and iii) create a-posteriori prescription maps for VRS. Five SR treatments (185,000, 247,000, 309,000, 370,000 and 432,000 seeds ha-1) were applied using …

Effect Of Cultural Strategies And Application Technologies On Weed Control In Flooded And Furrow-Irrigated Rice, Noah Hunter Reed

Graduate Theses and Dissertations

Weed control is a major problem that rice (Oryza sativa L.) producers face in the Mid-south every growing season. Restricted use of some rice herbicides has also highlighted the need for more research to be conducted on cultural weed control strategies and application technologies in rice. The aim of these studies was to evaluate rice weed control using various rice row widths, bed widths (irrigation-furrow spacing), rice cultivar selection, and nozzle type selection. Three field experiments were conducted in 2021 and 2022 across four sites at Lonoke, AR, Pine Tree, AR, Rohwer, AR, and Stoneville, MS. In experiment one, as …

A Cross-Sectional Study On The Impact Of The Covid-19 Pandemic On Sport-Related Concussion Clinical Presentation Within Adolescents And Adults, Emily Mcindoe

Graduate Theses and Dissertations

Introduction. The COVID-19 pandemic spanned across the globe in March 2020 and has since significantly impacted human life. There is evidence that supports symptom exacerbation and an increase in anxiety and depression in clinical presentation post-COVID-19 pandemic compared to pre-COVID-19 for multiple medical diagnoses. These medical diagnoses include migraines, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and mild cognitive impairment. The effect that the pandemic had on the clinical presentation of sports-related concussions is understudied. It is possible that the COVID-19 pandemic has altered the clinical presentation of concussions as seen in other medical diagnoses. Given the increased reporting of …

Development Of Lignin-Based Copolymers And Polymer Blends, David Chem

Graduate Theses and Dissertations

Increasing industrial interest in reducing fossil fuels in virgin polymer production and incorporating bio-based polymeric materials has led researchers to explore the potential of utilizing plant-based polymers such as lignin. Chapter 1 of this thesis presents a comprehensive overview of copolymerization and blending techniques for lignin and synthetic polymers, emphasizing different types of modifications and copolymerization techniques as well as key parameters such as temperature, reaction time, pH level, and solution compositions. These valorization methods are directed towards the development of high-value lignin-based materials with properties well-suited for various commercial applications. Chapter 2 offers a fundamental exploration into the amination …

The Effects Of Probiotics And Environment On The Swine Gut Microbiome, Bin Zuo

Graduate Theses and Dissertations

The gastrointestinal tract is crucial for nutrient absorption and immune system functionality. It employs a synergistic approach, merging physical and biochemical defenses, to counteract pathogens that enter through dietary or other external routes. This system also facilitates the breakdown of complex carbohydrates, a process beyond the host's innate capacity. In swine, gut microbiota early colonization plays a significant role in several physiological developments, shaped by a variety of determinants including maternal factors and environmental conditions. In the swine industry, the shift to indoor pig farming enhances efficiency but limits soil interaction, potentially impacting gut microbiota diversity. Additionally, the practice of …

Utilizing The Genetic Potentials Of Traditional Rice Varieties And Conserving Rice Biodiversity With System Of Rice Intensification Management, Yheni Dwiningsih

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The genetic potentials of rice cultivars will need to be expressed to their fullest if global rice production is to be expanded enough by 2050 to meet the increased demand of the expanding population while the availability of land and water per capita dwindles. New and ‘improved’ rice varieties have contributed greatly to increased production over the past 50 years, but the rate of rice yield increase based on genetic changes has declined in recent decades compared with the early years of the Green Revolution. In fact, many rice consumers continue to prefer to consume ‘traditional’ rice varieties (referred to …

Uncertainty In Streamflow Measurements Significantly Impacts Estimates Of Downstream Nitrate Export, Shannon L. Speir, C. Nathan Jones, Arial J. Shogren, Carla L. Atkinson

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Across watershed science, two key variables emerge–streamflow and solute concentration–which serve as the basis for efforts ranging from basic watershed biogeochemistry research to policy decisions surrounding watershed management. However, we rarely account for how error in discharge (Q) impacts estimates of downstream nutrient loading. Here, we examined the impact of uncertainty in streamflow measurements on estimates of downstream nitrate export using publicly available data from the U.S. Geological Survey (USGS). We characterized how uncertainty in stage-discharge relationships impacts annual flux estimates across 70 USGS gages. Our results indicate the interquartile range of relative error in Q was 33% across these …

The Spatial And Temporal Distribution Of Large Rock Blocks And Control On Landscape Evolution In The Ozarks, Chelsea Moran

Graduate Theses and Dissertations

Geologists often use landscape form to infer landscape processes through time. While climate and tectonics shape geomorphic form, the potential range of spatial or temporal scales that can shape any specific landscape can render landscape process-form based hypotheses too general for consideration. Contributions by mathematical modeling have helped bridge the gap between inferring processes from form, notably in how sediment transport dynamics shape hillslopes. However, few models encapsulate the movement of large rock blocks ( >2 meters across) and their potential impact as hillslope sediment transport disruptors. The Upper Buffalo River watershed (BRW) in the Ozarks of northern Arkansas has …

Evaluation Of Weed Control Efficacy And Crop Tolerance To Florpyrauxifen-Benzyl Coated Onto Urea, Bodie Lyn Cotter

Graduate Theses and Dissertations

Frequent off-target movement occurrences to soybean [Glycine max (L.) Merr.], rice (Oryza sativa L.) injury, and a lack of barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] control followed the commercial launch of florpyrauxifen-benzyl in 2018. Florpyrauxifen-benzyl is a synthetic auxin, Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 4 herbicide used for postemergence weed control in rice and labeled for application at 30 g ae ha-1. Previous research documented that soybean was susceptible to injury following spray applications of florpyrauxifen-benzyl at less-than-labeled rates, and certain varieties of rice are less tolerant to spray-applied florpyrauxifen-benzyl at 30 g ae …

Evaluating Differences In Optical Properties Of Indolent And Aggressive Murine Breast Tumors Using Quantitative Diffuse Reflectance Spectroscopy, Joel Rodriguez Troncoso, Umme Marium Mim, Jesse D. Ivers, Santosh K. Paidi, Mason G. Harper, Khue G. Nguyen, Sruthi Ravindranathan, Lisa Rebello, David E. Lee, David A. Zaharoff, Ishan Barman, Narasimhan Rajaram

Biomedical Engineering Faculty Publications and Presentations

We used diffuse reflectance spectroscopy to quantify tissue absorption and scattering-based parameters in similarly sized tumors derived from a panel of four isogenic murine breast cancer cell lines (4T1, 4T07, 168FARN, 67NR) that are each capable of accomplishing different steps of the invasion-metastasis cascade. We found lower tissue scattering, increased hemoglobin concentration, and lower vascular oxygenation in indolent 67NR tumors incapable of metastasis compared with aggressive 4T1 tumors capable of metastasis. Supervised learning statistical approaches were able to accurately differentiate between tumor groups and classify tumors according to their ability to accomplish each step of the invasion-metastasis cascade. We investigated …

Detection Of Dsrab Operon Expression In Desulfotalea Psychrophila Cells Subjected To Simulated Martian Conditions Of Temperature And Regolith's Sulphate Minerals Composition, Sergio Mosquera, Mack Ivey, Vincent F. Chevrier

Biological Sciences Faculty Publications and Presentations

Discoveries of transient liquid water in the Martian polar caps and the presence of liquid lakes and subsurface oceans in icy satellites have increased the interest of scientists in the capabilities of terrestrial extremophiles to grow and remain metabolically active in these extreme environments. The principal goal of this research is to understand the metabolic capacity of the anaerobic psychrophile, Desulfotalea psychrophila, cultured at subfreezing temperatures in media containing various concentrations of sulphate minerals. In this regard, our experiments focused on the detection of D. psychrophila survival and active metabolism, employing a biochamber that can recreate Martian temperatures. Using …

Nutritional-Environmental Trade-Offs In Potato Storage And Processing For A Sustainable Healthy Diet, Aubin Payne, Ebenezer M. Kwofie, Prince Agyemang, Jamie Baum

Biological and Agricultural Engineering Faculty Publications and Presentations

Over the last decade, poor diets and limited access to nutritious foods have been critical drivers of micronutrient deficiency in human health. However, food fortification at an industrialized scale in developed countries has helped eliminate deficiency-related diseases. In developing countries, fortified foods and biofortified materials have been delivered to nutrient-deficient communities. While these strategies have produced significant and acclaimed results, reports from the Food and Agricultural Organization suggest that over a quarter of the world’s population suffers from micronutrient deficiency. This implies that there are still declines in micronutrients in food products at different nodes along the food value chain …

Representativeness Evaluation Of Delta-Flux Eddy Covariance Towers For Assessing Greenhouse Gas Emissions From Rice Fields In The Mid-South Region, Katherine Skiles

Biological and Agricultural Engineering Undergraduate Honors Theses

Rice grown in 5 states across the Mid-South (AR, LA, MS, TX, and MO) account for nearly 80% of all domestic U.S. rice production. Methane emissions produced during rice farming and the large seasonal water demand to maintain flooded fields have created a need for alternative irrigation research that can reduce methane emissions and conserve water. Structures called eddy covariance towers (ECTs) can observe methane and other flux responses to changing irrigation styles, and their data is shared across flux tower networks such as Delta-Flux in the Mid-South. The Delta-Flux network is relatively new, and its data-sharing capacity is not …

Examining The Benefits Of Using Rainfall To Supplement Alternate Wetting And Drying Irrigation In Zero-Grade Rice Fields In Central Arkansas, Leo Black

Biological and Agricultural Engineering Undergraduate Honors Theses

Arkansas farmers account for more than 50% of United States production of rice, a crop that requires 3 to 5 times as much water as other regional crops. Methods of reducing water use and increasing its efficiency are being explored throughout the rice production industry, including irrigation management, better land grading, and precipitation capture. This project investigates the combination of these methods. The objectives of this project were to assess field-level water inputs, identify relationships between rice growth and water input, and analyze weather patterns in zero-grade fields in central Arkansas. Subsequent results were used to determine if there is …

The Pseudomonas Syringae Pv. Tomato Dc3000 Effector Hopd1 Interferes With Cellular Dynamics Associated With The Function Of The Plant Immune Protein Atnhr2b, Luis Francisco Marin-Ponce, Catalina Rodriguez-Puerto, Perla Rocha-Loyola, Clemencia M. Rojas

Entomology and Plant Pathology Faculty Publications and Presentations

The plant pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) causes disease in tomato, in the model plant Arabidopsis thaliana, and conditionally in Nicotiana benthamiana. The pathogenicity of Pst DC3000 is mostly due to bacterial virulence proteins, known as effectors, that are translocated into the plant cytoplasm through the type III secretion system (T3SS). Bacterial type III secreted effectors (T3SEs) target plants physiological processes and suppress defense responses to enable and support bacterial proliferation. The Pst DC3000 T3SE HopD1 interferes with plant defense responses by targeting the transcription factor NTL9. This work shows that HopD1 also targets the …

Coordinated Regulation Of Myonuclear Dna Methylation, Mrna, And Mirna Levels Associates With The Metabolic Response To Rapid Synergist Ablation-Induced Skeletal Muscle Hypertrophy In Female Mice, Ahmed Ismaeel, Nicholas T. Thomas, Mariah Mccashland, Sebastian Edman, Johanna T. Lanner, Vandré C. Figueiredo, Christopher S. Fry, John J. Mccarthy, Yuan Wen, Kevin A. Murach, Ferdinand Von Walden

Health, Human Performance and Recreation Faculty Publications and Presentations

The central dogma of molecular biology dictates the general flow of molecular information from DNA that leads to a functional cellular outcome. In skeletal muscle fibers, the extent to which global myonuclear transcriptional alterations, accounting for epigenetic and post-transcriptional influences, contribute to an adaptive stress response is not clearly defined. In this investigation, we leveraged an integrated analysis of the myonucleus-specific DNA methylome and transcriptome, as well as myonuclear small RNA profiling to molecularly define the early phase of skeletal muscle fiber hypertrophy. The analysis of myonucleus-specific mature microRNA and other small RNA species provides new directions for exploring muscle …

Associations Between Acute And Chronic Lifetime Stressors And Psychosis-Risk Symptoms In Individuals With 22q11.2 Copy Number Variants, Jasmine Modasi, Vahe Khachadourian, Kathleen O'Hora, Leila Kushan, George M. Slavich, Grant S. Shields, Eva Velthorst, Carrie E. Bearden

Psychological Science Faculty Publications and Presentations

Background

The 22q11.2 deletion (22q11Del) is among the strongest known genetic risk factors for psychosis. Stress, a known risk factor for psychosis in the general population, has seldom been studied in 22q11Del. We investigated how lifetime stressors related to symptomatic outcomes in patients with 22q11Del. We also explored this association in individuals with 22q11.2 duplications (22q11Dup), which may be potentially protective against psychosis. Method

One hundred individuals (46 with 22q11Del, 30 with 22q11Dup, and 24 healthy controls; M_age = 17.30 years±10.15) were included. Logistic models were used to examine cross-sectional associations between lifetime acute and chronic stressors (severity and …

Induced Pluripotent Stem Cells Derived From Patients Carrying Mitochondrial Mutations Exhibit Altered Bioenergetics And Aberrant Differentiation Potential, Fibi Meshrkey, Kelly M. Scheulin, Christopher M. Littlejohn, Joshua Stabach, Bibhuti Saikia, Vedant Thorat, Yimin Huang, Thomas Laframboise, Edward J. Lesnefsky, Raj R. Rao, Franklin D. West, Shilpa Iyer

Biological Sciences Faculty Publications and Presentations

Background

Human mitochondrial DNA mutations are associated with common to rare mitochondrial disorders, which are multisystemic with complex clinical pathologies. The pathologies of these diseases are poorly understood and have no FDA-approved treatments leading to symptom management. Leigh syndrome (LS) is a pediatric mitochondrial disorder that affects the central nervous system during early development and causes death in infancy. Since there are no adequate models for understanding the rapid fatality associated with LS, human-induced pluripotent stem cell (hiPSC) technology has been recognized as a useful approach to generate patient-specific stem cells for disease modeling and understanding the origins of the …

The Evolutionary Responses Of Life-History Strategies To Climatic Variability In Flowering Plants, James Boyko, Eric R. Hagen, Jeremy M. Beaulieu, Thais Vasconcelos

Biological Sciences Faculty Publications and Presentations

• The evolution of annual or perennial strategies in flowering plants likely depends on a broad array of temperature and precipitation variables. Previous documented climate life-history correlations in explicit phylogenetic frameworks have been limited to certain clades and geographic regions.
• To gain insights which generalize to multiple lineages we employ a multi-clade approach analyzing 32 groups of angiosperms across eight climatic variables. We utilize a recently developed method that accounts for the joint evolution of continuous and discrete traits to evaluate two hypotheses: annuals tend to evolve in highly seasonal regions prone to extreme heat and drought; and annuals tend to …

University Of Arkansas, Chemistry And Biochemistry Department Graduate Student Publications, 2018- November 2023. 39p., Jeremy Smith, Lutishoor Salisbury

University Libraries Faculty Publications and Presentations

This report provides a compilation of the research publications by the Chemistry and Biochemistry (CHBC) Graduate students for the period: 2018-November 2023. It includes publications by the CHBC graduates and those where a CHBC faculty was the main advisor. It includes a summary of the research. The listing is organized according to type of publications within specific years.

University Of Arkansas, Chemistry And Biochemistry Department Research Publications, 2014- November 2023. 107p., Jeremy Smith, Lutishoor Salisbury

University Libraries Faculty Publications and Presentations

This report provides a compilation of the research publications by the Chemistry and Biochemistry faculty for the period: 2014 - November 2023. The information was gathered from major databases in science and technology including Web of Science, SciFinder, Reaxys, PubMed, IEEE Explore and Engineering Index. At least one author in each of the publications has the CHBC department as its affiliation. It includes a table summarizing the research. The listing is organized according to type of publications within specific years.