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Controls On Nutrient And Sediment Export In A Non-Perennial Agricultural Stream, Kathleen Cutting

Graduate Theses and Dissertations

Climate change is expected to increase flow variability and intermittency in streams, changing the magnitude and timing nutrient and sediment delivery. This may exacerbate water quality issues in agricultural landscapes, where nutrient and sediment inputs are often elevated. Elevated nutrients can drive eutrophication in downstream waterways, and excess sediment loss can decrease primary productivity. Non-perennial headwater streams are particularly vulnerable to the impacts of climate change and agriculture as they serve as key sites for nutrient cycling at the terrestrial-aquatic interface. Despite their importance, the interactive effects of agriculture and stream intermittency, as well as unpaved roads in rural watersheds …

Effectiveness Of Maternal Bovine Appeasing Substance Administered To Newly Received, High-Risk Stocker Calves, Elle Johnston

Animal Science Undergraduate Honors Theses

Stocker cattle purchased at auction can be susceptible to disease due to the stressors associated with the auction process. These cattle are labeled “high-risk” due to their compromised immune system during transportation, handling, and vaccination processes. The objective of this study was to determine the efficacy of a maternal bovine appeasing substance, FerAppease, on growth performance and behavior of stocker cattle. Male beef calves (n=80) were purchased at auction and transported to the University of Arkansas Division of Agriculture Savoy Research Complex Beef Stocker Unit. Steers and bulls were of varying age, breed, and temperament. Upon arrival to the facility …

Real Time Adaptive Control Of A Pid Via Genetic Algorithm Machine Learning Systems, Cemre Tas

Graduate Theses and Dissertations

The most common control method that is utilized by all industries across the world is the proportional-integrative-derivative controller (PID) due the relatively low cost and complexity of the system. However, there are draw-backs with PIDs, it is not adaptative to a changing system, so it works on nominal systems, and it starts breaking down when a system begins to have a non-linear response. The method chosen to overcome both is the utilization of machine learning with the use of genetic algorithms.

This method allows any PID system to be capable of adapting in real-time, while not adding significant additional cost …

Quantifying The Effects Of Urbanization On Stream Nutrient Loads And Decomposition, Caroline Anscombe

Graduate Theses and Dissertations

Urban stream syndrome (USS) refers to the common symptoms of degradation in urban streams globally. Two symptoms of USS are increased nutrient and salt concentrations in streams, affecting ecosystem structure and function. Excess nutrients negatively impact freshwater ecosystems, placing downstream habitats at risk of eutrophication and harmful algal blooms. Excess salt runoff, derived from road salt application, is toxic to freshwater organisms and affects leaf litter decomposition, the base of aquatic food webs. Here, I aimed to quantify the effects of nutrient pollution and salinization on urban water quality and ecosystem function. Despite the widespread consequences of nutrient pollution, most …

Utility Of John Deere's See & Spray Ultimate In Southern U.S. Row Crops, Tristen Avent

Graduate Theses and Dissertations

Row crop producers across the southern United States are observing a boom in technological advancement to improve operational efficiency. Additionally, environmental concerns and reduced profit margins drive the adoption of targeted pesticide application technologies like the John Deere See & Spray. This technology is relatively new, introduced in 2022, and producers need more insight into the shortcomings, potential herbicide savings, and the economic benefits of adoption. Since 2021, research has been conducted in Keiser, AR, with additional collaborative projects in Mississippi, North Carolina, Indiana, and Illinois. Five different objectives were addressed in this research: 1) to determine the impact of …

Crispr-Cas9 Integration Of Salmon Elovl2 In Zebrafish Enhances Lc-Pufa Biosynthesis And Growth Across Diets, Waleed Sami J. Al-Bachry

Graduate Theses and Dissertations

Fish are a rich source of EPA and DHA, which are well-known long-chain polyunsaturated fatty acids (LC-PUFAs). The sustainable production of these essential fatty acids poses significant challenges, mainly due to our dependence on marine fish and certain nuts. CRISPR-Cas system was utilized to insert the elongation of long-chain fatty acids-like2 (Elovl2) gene from Salmo salar into Danio rerio. Elovl2 was introduced at 10-15-minute post-fertilization, and successful integration confirmed by PCR genotyping, sequencing and expression of EGFP. Approximately 67% of injected embryos successfully exhibited EGFP and sequence results verified the gene integration of Salmo salar Elovl2 at the first start …

Nonparametric Methods For Bayesian Community Detection In Complex Networks, Kedran Young

Graduate Theses and Dissertations

Network analysis is becoming an increasingly popular interdisciplinary area of study, with emerging interest in fields like sociology, biology, economics, and ecology. Within the niche of network analysis, capturing the community structure of a network is one important achievement that many statisticians have been working toward over recent decades. The most popular modeling technique for latent community detection is the Stochastic Block Model (SBM), which falls into the category of latent variable models and will serve as the baseline model throughout this thesis. SBM is widely regarded as the most effective community detection method as it detects latent community membership …

Gender, Politics, And Power: How Women Presidential Candidates Are Framed By News Narratives, Victoria Hernandez

Graduate Theses and Dissertations

The aim of this study was to look at the coverage of the presidential campaigns of Hillary Clinton in 2016 and Kamala Harris in 2024 during the Democratic National Convention, and analyze the differences in regard to gender, race, and political bias. The examination of these news narratives helps explore a question of whether journalists report with bias when covering politics. The researcher analyzed 11 published pieces from five mainstream media outlets. Findings of the study show that bias is unavoidable even when a journalist strives for objectivity which does not exist in newsrooms across the political spectrum. The findings …

Investigating Evolution Through The Lens Of Ai-Driven Protein Exploration And Phylogenetic Modeling, Mataya Duncan

Graduate Theses and Dissertations

Recent advances in computational biology, artificial intelligence, and sequencing technologies have enabled new perspectives for addressing longstanding questions in evolutionary biology. Increased computational power has made large-scale simulations feasible for investigating diverse aspects of evolutionary and phylogenetic modeling. Similarly, deep learning algorithms now allow for the prediction of reasonably accurate tertiary protein structures, unlocking the potential for investigating diversity and evolution of protein structure across a broad range of organisms. This thesis presents two studies that target different aspects of evolutionary inference from unique perspectives. Yet, the share an overarching goal of presenting new perspectives on the evolutionary basis of …

Experiences Of Black Senior Housing Officers At Predominantly White Institutions In The South, Christian M. Robinson

Graduate Theses and Dissertations

This study examines the lived experiences of Black Senior Housing Officers (SHOs) at predominantly white institutions (PWIs) in the Southern United States. This narrative inquiry study interviewed nine Black SHOs who worked at Southern PWIs. The findings of this study are that participants emphasized that racism remains a significant and present concern at their institutions as informed by Critical Race Theory (CRT). One participant stressed the importance of Black professionals fully understanding the historical context of the South when working in higher education, noting that this knowledge was critical for survival and success. Many participants also described how effective mentorship …

Multi-Decadal Land Change Dynamics In Indonesia: Disentangling The Cycle Of Agricultural Land Conversions, Urbanization, And Deforestation, Wei Lun Tay

Graduate Theses and Dissertations

Land use and land cover change (LULCC) significantly impacts Earth’s environmental, climatic, and human systems, especially in tropical regions rich in natural resources and undergoing rapid development. This study examined the spatiotemporal dynamics of LULCC in Indonesia between 2003 and 2023 using remote sensing and geographic information systems/science (GISci) and explored knowledge gaps in agricultural land conversions and the impact of food security programs such as the Food Estate Program. This study employed the Moderate Resolution Imaging Spectroradiometer (MODIS) MCD12Q1 land cover data available through Google Earth Engine, and classified land cover changes into four dominant categories: forest land, mixed …

Computationally Guided Liquid Crystal-Based Competitive Binding Sensing Platform For Optical Detection Of Spike Protein, Homa Ghaiedi, Shubham Pandey, Sophia Ezendu, Tibor Szilvasi, Karthik Nayani

Chemical Engineering Faculty Publications and Presentations

A liquid crystal (LC)-based sensing platform for the rapid optical detection of SARS-CoV-2 ' s spike protein's receptor binding domain (RBD) domain is introduced. This platform utilizes a thermotropic LC, hosted on metal-cation decorated substrates, onto which the spike protein can competitively bind. Density functional theory (DFT) calculations guide the experiments that reveal a homeotropic-to-planar transition in the LCs upon exposure to SARS-CoV-2 spike-decorated yeast, providing a basis for sensitive virus detection. The sensor's reversibility/specificity is confirmed through antibody-induced orientation recovery of the LCs initial orientation. Strikingly, the sensor can detect approximate to 2000 copies of the spike protein per …

Quantifying Treatment Response To A Macrophage-Targeted Therapy In Combination With Immune Checkpoint Inhibitors After Exposure To Conventional Chemotherapy, Shelby N. Bess, Gaven K. Smart, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Background: Conventional chemotherapeutic agents, such as 5-fluorouracil (5-FU), can exert anti-tumor effects through immunogenic cell death (ICD) induction. Researchers have found hallmarks that quantify ICD (such as the translocation of HMGB1 and calreticulin). Although chemotherapeutic agents can induce ICD, they increase the expression of immune checkpoints, limiting their effectiveness. Studies have emphasized the importance of investigating the heterogeneous responses of cells co-localized in a solid tumor (macrophages, tumor cells, etc.) to ICD induction. However, these studies were performed in vivo, which limits the collection of information on cell-cell interactions due to model complexity.

Methods: In this study, we used a …

Exploring Non-Traditional Yeast For Flavor Innovation In Non-Alcoholic Beer, Andrew Maust, Rahul Sen, Scott Lafontaine

Food Science Faculty Publications and Presentations

The demand for nonalcoholic beer (NAB) is growing, with nontraditional yeast strains emerging as valuable tools for brewers to craft distinct NABs. However, independent information about the performance of these commercially available yeasts remains limited. In this study, 11 nontraditional yeast strains were evaluated at two wort nutrient levels to assess their impact on beer chemistry, sensory attributes, and volatile profiles. Basic fermentation metrics were monitored, followed by descriptive sensory analysis and GC-MS/MS quantification of volatile compounds. Results revealed significant differentiation among yeast strains with unique aroma and flavor profiles driven by variations in ester production, fusel alcohol synthesis, and …

Greenhouse Gas Emissions From Flood-Irrigated Rice As Affected By Phosphorus Fertilizer Source, Chandler M. Arel, Kristofor R. Brye, Diego Della Lunga, Trenton L. Roberts, Richard Adams

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Research into alternative phosphorus (P) fertilizer sources that may be able to supplement P resources is necessary. Struvite (MgNH4PO4 · 6H2O) can be made by removing excess nutrients from waste sources and may reduce greenhouse gas (GHG) emissions from cropping systems. This study sought to quantify GHG [i.e., methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)] fluxes, season-long emissions, and net GHG emissions from chemically precipitated struvite (CPST) and synthetic and real-wastewater-derived electrochemically precipitated struvite (ECST) compared to monoammonium phosphate (MAP) and an unamended control (UC) from flood-irrigated rice (Oryza sativa) grown in P-deficient, silt loam soil in a …

Effect Of Heat Stress On Ileal Epithelial Barrier Integrity In Broilers Divergently Selected For High- And Low-Water Efficiency, Elizabeth S. Greene, Brooklee Roach, Maria Fernandez Cuadrado, Sara Orlowski, Sami Dridi

Poultry Science Faculty Publications and Presentations

Water scarcity and rising global temperatures are two of the greatest current and future threats to poultry sustainability. Therefore, selection for water efficiency (WE) and heat resilience are of vital importance. Additionally, intestinal integrity is of critical importance under challenging conditions to maintain nutrient absorption and therefore, growth and performance of broilers. Here, we examined the effect of chronic cyclic heat stress (HS) on the ileal expression profile of tight-junction, gap-junction, adherens, and desmosome genes in the fourth generation of divergently selected low (LWE)- and high water efficient (HWE)-chicken lines. LWE birds exhibited higher levels of gut permeability, regardless of …

Registration Of R19-42848 As A Drought-Tolerant, High-Yielding Soybean Germplasm Line, Chengjun Wu, Derrick Harrison, Liliana Florez-Palacios, Andrea Acuna, Daniel Rogers, Rafael Marmo, John Carlin, Ben Fallen, Leandro Mozzoni, Caio Cenella Vieira

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

R19-42848 (Reg. no. GP-532, PI 706865) is a high-yielding soybean [Glycine max (L.) Merr.] germplasm with drought tolerance released by the University of Arkansas System - Division of Agriculture Research & Extension Center in 2024. It is an F4-derived selection from the cross R12-2237 (drought-tolerant) x R12-519 (high-yielding). R19-42848 is a conventional (non-genetically modified) soybean with a relative maturity of 5.2. Plants have determinate growth habit with purple flower color, gray pubescence, and tan pod wall at maturity. Seed of R19-42848 has buff hilum color, 100-seed weight of 13.8 g, and contains on average 404.5 and 211.5 g kg-1 of …

Anxiety Sensitivity And Intolerance Of Uncertainty Uniquely Explain The Association Of The Late Positive Potential With Generalized Anxiety Disorder Symptoms, Matt R. Judah, Hannah C. Hamrick, Benjamin Swanson, Morgan S. Middlebrooks, Grant S. Shields

Psychological Science Faculty Publications and Presentations

Studies suggest that generalized anxiety disorder (GAD) symptoms are related to late positive potential (LPP) responses to negative images, suggesting greater attention. Anxiety sensitivity (AS) and intolerance of uncertainty (IU) are cognitive factors in GAD vulnerability that may be activated by negative stimuli, thereby explaining why the LPP and GAD symptoms are related. We examined whether AS and IU explain the association of the LPP with GAD symptoms. Eighty-seven (77% women) young adults viewed 60 negative and 60 neutral images. The LPP was examined using both frequentist and Bayesian approaches. This revealed unique indirect effects of the LPP on GAD …

Drought And Herbivory Drive Physiological And Phytohormonal Changes In Soybean (Glycine Max Merril): Insights From A Meta-Analysis, Manish Gautam, Rupesh Kariyat

Entomology and Plant Pathology Faculty Publications and Presentations

With climate change, abiotic and biotic stresses such as drought and herbivory are predicted to further diminish agricultural productivity. Soybean (Glycine max [L.] Merrill), a crop of global economic importance, is vulnerable to both. However, the interactive effects of drought and herbivory on soybeans haven't been explored, especially through the lens of physiological and phytohormonal changes. To address this, we conducted a meta-analysis from 114 published studies, further reduced to 31 after removing redundancy, with data on physiological (photosynthesis and stomatal conductance) and phytohormonal traits (jasmonic acid [JA] and salicylic acid [SA]) of soybeans under drought, herbivory, and their combination. …

Three Reference Genomes For Freshwater Diatom Ecology And Evolution, Wade R. Roberts, Andrew J. Alverson

Biological Sciences Faculty Publications and Presentations

Diatoms are an important component of marine and freshwater ecosystems. Although the majority of described diatom species live in freshwater systems, genome sequencing efforts have focused primarily on marine species. Genomic resources for freshwater species have the potential to improve our understanding of diatom ecology and evolution, particularly in the context of major environmental shifts. We used long- and short-read sequencing platforms to assemble reference genomes for three freshwater diatom species, all in the order Thalalassiosirales, which are abundant in the plankton of oceans, lakes, reservoirs, and rivers worldwide. We targeted three species that cover the breadth of phylogenetic diversity …

Reweighting Configurations Generated By Transferable, Machine Learned Models For Protein Sidechain Backmapping, Jacob Monroe

Chemical Engineering Faculty Publications and Presentations

Multiscale modeling requires the linking of models at different levels of detail, with the goal of gaining accelerations from lower fidelity models while recovering fine details from higher resolution models. Communication across resolutions is particularly important in modeling soft matter, where tight couplings exist between molecular-level details and mesoscale structures. While multiscale modeling of biomolecules has become a critical component in exploring their structure and self-assembly, backmapping from coarse-grained to fine-grained, or atomistic, representations presents a challenge, despite recent advances through machine learning. A major hurdle, especially for strategies utilizing machine learning, is that backmappings can only approximately recover the …

Use Of Biochar And Industrial Hemp For Remediation Of Heavy-Metal-Contaminated Soil: Root Uptake And Translocations For Cd, Pb, And Zn, Sophie Sward, Kristofor R. Brye, David M. Miller, Dietrich V. Thurston

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Phytoremediation has been reported as a more energy-efficient, and therefore cost-effective, method of environmental restoration compared to traditional remediation methods for heavy-metal-contaminated soils. Biochar has been shown to have variable effects on remediation potential in heavy-metal-contaminated soils. The objective of this study was to evaluate the effects of soil contamination level (i.e., low, medium, and high), industrial hemp (Cannabis sativa L.) cultivar (i.e., ‘Carmagnola’ and ‘Jinma’), biochar rate (i.e., 0, 2, 5, and 10% by volume), and their interactions on root tissue Cd, Pb, and Zn concentrations and uptakes; whole-plant Cd, Pb, and Zn uptakes; and translocation factors after 90 …

Identifying Herbicides To Manage Weeds In A Buckwheat Cover Crop And For The Control Of Volunteers, Taylor Randell-Singleton, Hannah E. Wright-Smith, Lavesta C. Hand, Jenna C. Vance, A. Stanley Culpepper

Horticulture Faculty Publications and Presentations

Buckwheat (Fagopyrum esculentum) is a fast-growing plant that quickly produces a dense groundcover. The utilization of buckwheat as a cover crop in vegetable production could be beneficial to Georgia producers, however for successful adoption, weed control in the cover crop coupled with control of buckwheat volunteers must be achievable. A preemergence (PRE) and a postemergence (POST) experiment were each conducted three times in Ty Ty, GA (2020-2021) addressing these objectives. In the PRE study, acetochlor at 0.56 lb ai acre(-1) injured buckwheat up to 16% without negatively influencing growth, suggesting potential for use in buckwheat for weed control. Flumioxazin, fomesafen, …

The Mechanistic Target Of Rapamycin Mediates Clostridium Perfringens-Induced Chicken Necrotic Enteritis Attenuated By Secondary Bile Acid Deoxycholic Acid, Mohit Bansal, Tahrir Alenezi, Ying Fu, Janashrit Shrestha, Ayidh Almansour, Hong Wang, Anamika Gupta, Rohana Liyanage, Xiaolun Sun

Poultry Science Faculty Publications and Presentations

Clostridium perfringens is a prevalent gut bacterial pathogen in humans and animals. This study investigated the role of the mechanistic targets of rapamycin (mTOR) and deoxycholic acid (DCA) on C. perfringens intestinal infection. Chickens were sequentially infected with Eimeria maxima and received the mTOR inhibitor rapamycin and DCA. C. perfringens-induced necrotic enteritis (NE) was evaluated using body weight gain (BWG), histopathology, bile acids, pathogen colonization, cell infiltration and death, and gene expression. The significant difference of p < 0.05 was analyzed by one-way ANOVA and multiple comparisons. Notably, rapamycin strongly reduced the subclinical and clinical NE histopathologies. DCA and DCA combined with rapamycin alleviated clinical NE and BWG loss. Rapamycin, DCA, and DCA + rapamycin attenuated bile acid reduction in NE birds, and they also reduced immune cell infiltration into the intestinal lamina propria as well as immune cell migration in vitro. At molecular levels, DCA and DCA + rapamycin reduced proinflammatory IFN gamma, MMP9, IL23, and IL17 gene expression. Rapamycin, DCA, and DCA + rapamycin reduced NE-induced intestinal cell apoptosis. Together, these results suggest that mTOR signaling mediates C. perfringens-induced ileitis, and combining mTOR inhibition and DCA improves the intervention efficacy against NE ileitis and BWG loss.

Enthesis Size And Hand Preference: Asymmetry In Humans Contrasts With Symmetry In Nonhuman Primates, Lucyna A. Bowland, Lesley H. Eason, Lukas Kyle Delezene, Michael J. Plavcan

Anthropology Faculty Publications and Presentations

ObjectivesHumans display species-wide right-hand preference across tasks, but this pattern has not been observed at comparable levels in nonhuman primates, suggesting the behavior arose after the panin-hominin split. Muscle attachment sites (entheses) are used to infer soft tissue anatomy and reconstruct behaviors within skeletal populations, but whether entheseal size asymmetry can reflect hand preference remains unclear. If entheseal asymmetry is linked to hand preference, we expect to see greater asymmetry in human hands, where hand preference is more pronounced, compared to nonhuman primates. We tested for bilateral asymmetry in the size of the opponens pollicis muscle flange using a sample …

Overexpression And Biophysical And Functional Characterization Of A Recombinant Fgf21, Phuc Phan, Jason Hoang, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast growth factor 21 (FGF21) is an endocrine FGF that plays a vital role in regulating essential metabolic pathways. FGF21 increases glucose uptake by cells, promotes fatty acid oxidation, reduces blood glucose levels, and alleviates metabolic diseases. However, detailed studies on its stability and biophysical characteristics have not been reported. Herein, we present the overexpression, biophysical characterization, and metabolic activity of a soluble recombinant FGF21 (rFGF21). The far-UV circular dichroism spectra of rFGF21 show a negative trough at 215 nm, indicating that the protein's backbone predominantly adopts a 13 sheet conformation. rFGF21 shows intrinsic tyrosine fluorescence at 305 nm. Thermal …

A Tale Of Too Many Trees: A Conundrum For Phylogenetic Regression, Richard Adams, Jennifer Roa Lozano, Mataya Duncan, Jack Green, Raquel Assis, Michael Degiorgio

Entomology and Plant Pathology Faculty Publications and Presentations

Just exactly which tree(s) should we assume when testing evolutionary hypotheses? This question has plagued comparative biologists for decades. Though all phylogenetic comparative methods require input trees, we seldom know with certainty whether even a perfectly estimated tree (if this is possible in practice) is appropriate for our studied traits. Yet, we also know that phylogenetic conflict is ubiquitous in modern comparative biology, and we are still learning about its dangers when testing evolutionary hypotheses. Here, we investigate the consequences of tree-trait mismatch for phylogenetic regression in the presence of gene tree-species tree conflict. Our simulation experiments reveal excessively high …

Evaporating Natural Parent Childcare Liberties Under New Parentage Laws, Jeffrey A. Parness

Arkansas Law Review

This Article explores the evaporating Due Process interests of natural childcare parents who are not unfit and who do not knowingly consent to diminished childcare liberties when the state recognizes new nonadoptive and nonbiological parents. Childcare liberty losses need not involve neglect or comparable bad acts rendering a parent unfit. They need not involve consent, actual or implied, by an adversely affected parent. On the new forms of nonadoptive and nonbiological childcare parents, the most recent UPAs and their state counterparts are illustrative. They recognize parentage in an individual who resides with and holds out a child as the individual’s …

Arkansas Law Review - Volume 77 Issue 4, Journal Editors

Arkansas Law Review

No abstract provided.

Workforce Forecasting For State Transportation Agencies: A Machine Learning Approach, Adedolapo Ogungbire, Suman Kumar Mitra

Civil Engineering Faculty Publications and Presentations

A decline in the number of construction engineers and inspectors at state transportation agencies (STAs) to manage the ever-increasing lane miles has emphasized the importance of workforce planning in these agencies. Forecasting workforce requirements is crucial for effective planning in any industry or agency. This study developed machine learning (ML) models to estimate the person-hour requirements of STAs at the project level. The Arkansas Department of Transportation (ARDOT) was used as a case study, using its employee and project details data between 2012 and 2021. ML regression models ranging from linear, tree ensembles, kernel-based, and neural network-based models were …