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Integrating Sustainability And Food Safety Through Quantitative Microbial Risk Assessment And Life Cycle Assessment Of Low-Moisture Foods, Jessica Bain

Graduate Theses and Dissertations

Food safety and sustainability are critical concerns in the food industry. However, these areas are often evaluated separately, leading to an incomplete understanding of the overall impact of food production on human health. This dissertation aims to integrate food safety with sustainability to provide a comprehensive assessment of the impact of low-moisture foods on human health, using the almond processing supply chain as a case study.

In addition to conducting life cycle assessments (LCA) of almond processing, wheat flour production, and dried apple processing, this dissertation aims to create a framework to bridge the gap between sustainability and food safety. …

Site Position, Tillage, And Soil Depth Effects On Soil Properties In A Furrow-Irrigated Rice Field On A Silt-Loam Soil, Hannah Nobles, Kristofor Brye, Diego Della Lunga

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The fundamental agronomic shift from conventional agricultural methods to conservation agriculture relies on understanding soil nutrient stratification with depth and under different tillage treatments. Assessment of nutrient stratification in the dynamic conditions of furrow-irrigated rice (Oryza sativa) systems in eastern Arkansas is absent. The objective of this study was to evaluate the effects of tillage [i.e., conventional tillage (CT) and no tillage (NT], site position (i.e., up-, mid-, and down-slope), soil depth interval (i.e., 0-10 and 10-20 cm), and their interaction on the difference (i.e., end of the season minus beginning of the season) in select soil chemical …

The Effect Of Common Road Salts And Organic Additives On Microbial Respiration In Urban Streams, Claire Meara

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Due to significant population growth and urbanization, there has been an increase in impervious surfaces such as roads and sidewalks. During winter, impervious surfaces are often treated with salt to make road conditions safer. However, this has significant impacts on water quality when salt enters urban streams during runoff events. The addition of road salts to urban streams has been shown to have detrimental effects to various organisms across trophic levels and affects nutrient cycling and greenhouse gas release. These findings have made the development of alternative treatments necessary, such as using organic additives, like beet juice, which can decrease …

Analyzing Food Sources And Food Insecurity Of Kichwa Farming Families In The Ecuadorian Amazon, Reina Watanabe

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

While the right to food is internationally recognized and the United Nations established the sustainable development goal to end hunger and achieve food security by 2030, many households remain without consistent access to food in 2024. In Latin America, approximately 4 in 10 households were reported as food insecure in 2020 with higher rates in rural and indigenous communities. Rural areas, which have great overlap with indigenous communities in Ecuador, experience disproportionately high levels of poverty and food insecurity compared to urban areas. The most populous indigenous nationality in the Ecuadorian Amazon and the participants of this study are the …

Frogs On A Plain: Spatial Ecology Of Crawfish Frogs In Arkansas’ Remnant Prairies, Elliot T. Lassiter

Graduate Theses and Dissertations

The prairie peninsula was an expansive and important habitat that covered much of midwestern North America, from Canada to Arkansas, USA. But the prairie peninsula has shrunk by as much as 99% since 1830, and therefore, land acquisition and public/private partnerships are critical for the preservation of prairies and their associated species. In Arkansas, one species that benefits from protected prairies is the Crawfish Frog (Lithobates areolatus), which is currently declining precipitously throughout its range. Adult Crawfish Frogs spend most of their lives in terrestrial refugia (crayfish burrows), making them highly vulnerable to habitat loss and fragmentation, thereby …

Investigating The Perceived Invisibility Of The Black Woman Leader In Fortune 500 Companies: Understanding Career Pathways Based On Insight And Intersectionality, Shana Jones Yarberry

Graduate Theses and Dissertations

There is a gap in the literature when examining the intersectionality of race, gender, and class. There is additional distance when evaluating the impact each intersection has on the career development of Black Women (BW) in Fortune 500 companies. The purpose of this study was to use a qualitative approach to investigate how the intersectionality of race, gender, and class impact the career advancement of BW while also identifying perceived barriers, historical patterns of career movement, and organizational efforts to support the ascension of BW in senior leadership. The Systems Theory Framework of Career Development and Intersectionality Theory were examined …

Predicting Different Psychological Profiles Amongst Substance Users., Zach J. Gray

Graduate Theses and Dissertations

Substance use disorders (SUDs) are some of the most prevalent issues facing society. As SUDs are highly individualized in how they manifest, recent work has attempted to classify distinct profiles of drug users to better understand what factors put someone at risk for shifting from casual substance use to developing a substance use disorder (SUD). Common risk factors for SUD development include stressor exposure, difficulties with emotion regulation, personality, and risky decision-making. As many of the behaviors that constitute SUDs are exhibited prior to potential diagnosis, developing “profiles” that combine these traits and experiences could eventually predict SUDs. The current …

Synthesis And Process Optimization Of Cellulose Nanocrystals From Miscanthus X. Giganteus For Commercial Viability, Jaspreet Kaur

Graduate Theses and Dissertations

Cellulose nanocrystals (CNCs), derivatives of an abundant biopolymer, i.e., cellulose, are emerging as promising alternatives to petrochemical-based products due to their unique properties, including biodegradability, low toxicity, high strength, low density, large surface area and low coefficient of expansion. CNCs have diverse applications ranging from food packaging and textiles to drug delivery and medical implants, etc. Despite their potential, the widespread commercialization of CNCs faces significant hurdles owing to the high environmental burden and production costs. They are mainly driven by the commonly used source utilized for CNC synthesis i.e., wood and the intensive synthesis process i.e., requirement of …

Influence Of Hydrologic And Anthropogenic Disturbance On Stream Populations And Communities, Sarah Frances Sorensen

Graduate Theses and Dissertations

Disturbances occur when an external force modifies a habitat, destroying living space, removing food resources, or altering or destroying habitat structure. In lotic systems, a primary source of disturbance is hydrologic disturbance, including drought and flood. Hydrologic disturbances lead to increased mortality rates and dispersal out of disturbed habitats, causing population sizes to decrease and changes to community structures. More research is needed on how disturbances impact stream species and communities, as disturbances are predicted to become more intense with climate change. This dissertation aims to understand how disturbance influences streams at both the population and community level, through a …

Decoding Fgf/Fgfr Signaling: Insights Into Biological Functions And Disease Relevance, Oshadi Edirisinghe, Gaetane Ternier, Zeina Alraawi, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast Growth Factors (FGFs) and their cognate receptors, FGFRs, play pivotal roles in a plethora of biological processes, including cell proliferation, differentiation, tissue repair, and metabolic homeostasis. This review provides a comprehensive overview of FGF-FGFR signaling pathways while highlighting their complex regulatory mechanisms and interconnections with other signaling networks. Further, we briefly discuss the FGFs involvement in developmental, metabolic, and housekeeping functions. By complementing current knowledge and emerging research, this review aims to enhance the understanding of FGF-FGFR-mediated signaling and its implications for health and disease, which will be crucial for therapeutic development against FGF-related pathological conditions.

Exploring The Capabilities Of Classifier-Free Guidance In Recommendation Tasks, Noah Buchanan

Graduate Theses and Dissertations

This thesis addresses the problem of recommending items to users based on their ratings of items through a diffusion recommender system. Regular recommender systems are already capable of efficient recommendation through conventional methods such as collaborative or content-based filtering. Diffusion is a new type of generative AI that aims to improve our previous AI's shortcomings in the generative domain, like Variational Autoencoders (VAEs) and Generative Adversarial Networks (GANs). We use diffusion to create a recommender system that mirrors the sequence users take when browsing and rating items. The current methods of recommendation with diffusion do not use the new innovation …

Multimodal Spectroscopy To Study Tumor Microenvironmental Changes In Vivo, April Mordi

Graduate Theses and Dissertations

Every year there are millions of new cancer diagnoses and deaths worldwide. While great strides have been made in technologies and drugs for cancer treatment, there is still a need to understand tumor response to therapy as many patients still endure treatment failure after completing their treatment regimen. Current clinical imaging techniques for detecting response to therapy are utilized weeks to months after the course of treatment, and present limitations to measuring response during treatment. Optical spectroscopy techniques can help meet this need to determine the response of tumors to treatment as it allows for near real-time in vivo characterization …

The Impact Of Wild Pigs (Sus Scrofa) On Avian Occupancy And Vegetation Structure, Kenneth Wilson

Graduate Theses and Dissertations

Invasive species, particularly wild pigs (Sus scrofa), pose a significant threat to native ecosystems through both direct and indirect impacts. Wild pigs are large-bodied omnivorous species that can consume a wide variety of plants and animals and are known for destructive foraging behaviors, which likely threatens avian communities through habitat alteration and can impact the long term structure of ecosystems where they are present.

In chapter 1, we used a combination of avian point count surveys, vegetation assessments, and camera trap surveillance to quantify how the occupancy of breeding birds in bottomland hardwood forests changed in relation to …

Causal Discovery In Time Series Data Using Deep Learning Techniques, Saima Zahin Farhana Absar

Graduate Theses and Dissertations

Causal structure learning from observational data has been an active field of research over the past decades. In the literature, different algorithms and models have been proposed, such as constrained-based methods and score-based methods including the emerging deep learning-based methods. However, most of the approaches apply to static and non-dynamic data only. In many applications, the data is temporal. For example, monitoring systems, weather surveillance systems, and stock data, to name but a few. Incorporating temporal information is an important extension of the causal discovery field. With the growth of observational data these days, the discovery of causal relationships from …

Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams

Entomology and Plant Pathology Faculty Publications and Presentations

Abstract

The scale and scope of comparative trait data are expanding at unprecedented rates, and recent advances in evolutionary modeling and simulation sometimes struggle to match this pace. Well-organized and flexible applications for conducting large-scale simulations of evolution hold promise in this context for understanding models and more so our ability to confidently estimate them with real trait data sampled from nature. Results

We introduce TraitTrainR, an R package designed to facilitate efficient, large-scale simulations under complex models of continuous trait evolution. TraitTrainR employs several output formats, supports popular trait data transformations, accommodates multi-trait evolution, and exhibits flexibility …

Polarimetry Terahertz Imaging Of Human Breast Cancer Surgical Specimens, Nikita Gurjar, Keith Bailey, Magda O. El-Shenawee

Electrical Engineering and Computer Science Faculty Publications and Presentations

Purpose

We investigate terahertz (THz) polarimetry imaging of seven human breast cancer surgical specimens. The goal is to enhance image contrast between adjacent tissue types of cancer, healthy collagen, and fat in excised breast tumors. Based on the biological perception of random growth of cancer and invasion of surrounding healthy tissues in the breast, we hypothesize that cancerous cells interact with the THz electric field in a different manner compared with healthy cells. This difference can be best captured using multiple polarizations instead of single polarization.

Approach

Time domain pulsed signals are experimentally collected from each pixel of the specimen …

Neural Network Architecture Search Enabled Wide-Deep Learning (Nas-Wd) Integrated Hyperspectral Imaging Understanding For Woody Breast In Poultry Processing, Chaitanya Kumar Reddy Pallerla

Graduate Theses and Dissertations

The development and implementation of a Wide & Deep (WD) learning model tailored for classification and regression tasks utilizing spectral data provides a robust solution to evaluate woody breast (WB) conditions in poultry fillets. This process begins with thorough data preprocessing, which includes loading spectral and classification datasets, imputing missing values with medians, and splitting the data into training and testing sets to ensure rigorous model evaluation. The WD model architecture integrates wide linear models and deep neural networks to harness the strengths of both approaches. The wide component excels at memorizing sparse feature interactions, while the deep component captures …

Two-Photon Imaging For Characterizing Tumor Microenvironmental Changes In Non-Small Cell Lung Cancer Associated With Metastatic Recurrence, Paola Monterroso Diaz

Graduate Theses and Dissertations

Lung cancer remains the leading cause of cancer deaths, comprising nearly 25% of all cancer deaths (Sung et al., 2021a). The five-year survival rate of patients with non-small cell lung carcinoma (NSCLC) remains significantly low given that over half present with locally advanced or metastatic disease at time of diagnosis, and experience tumor recurrence following therapeutic intervention (Tamura et al., 2015; Uramoto & Tanaka, 2014). Current evaluation techniques to assess treatment response are lacking, given they are implemented several weeks after treatment completion and are solely based on anatomical changes in tumor size, forgoing other criteria such as functional or …

Blend Matters: Interactions Of Rice Cultivars On Milling, Physico-Chemical & End Use Traits, Bindu Regonda

Graduate Theses and Dissertations

Rice blending or mixing of different rice cultivars, a common practice in the industry, significantly impacts processing efficiency and end-product quality, yet its effects on end products remain understudied. This research investigated the implications of blending contemporary Arkansas rice cultivars through two comprehensive studies focusing on milling yields and physicochemical properties, instantization, and parboiling processes. Five long-grain cultivars, including hybrids (RT 7521 FP, RT 7321 FP, XP 753) and purelines (Ozark, CLL 16), were blended in various combinations and different drying.

The first study revealed that blending significantly affected milling yields and physicochemical attributes. Pre-drying blending yielded better results compared …

Carbon Dioxide Dynamics In The Carbonate Critical Zone, Savoy Experimental Watershed, Arkansas, Usa, Michael Darvin Jones

Graduate Theses and Dissertations

The dynamics of carbon dioxide (CO₂) within the Earth’s critical zone (CZ) are essential for driving spatial and temporal variations of carbonate dissolution and precipitation, which are fundamental to subsurface porosity and permeability development. However, there is still a significant knowledge gap regarding the patterns of CO₂ transport and production within the carbonate critical zone (CCZ). In this study, we investigated these dynamics within a mantled karst terrain at the Savoy Experimental Watershed (SEW) in Northwest Arkansas.

Previous monitoring of partial pressure of CO₂ (PCO₂) and dissolution rates at karst springs in …

Comparison Of Statistical And Machine Learning Genomic Prediction Methods In Plant Breeding: Case Studies In Maize And Soybean, Igor Kuivjogi Fernandes

Graduate Theses and Dissertations

Plant breeding is essential to increase genetic gain and food production worldwide. This study was conducted to evaluate new ways to use machine learning (ML) to tackle plant breeding challenges, where two ideas were tested — the first chapter focuses on how to combine genetic and environmental data using ML to improve the prediction of maize grain yield in multi-environment trials, while the second chapter centers on how to couple feature selection of molecular markers with ML to enhance prediction of yield in soybean, and, in both cases, ML approaches were compared to well-established statistical methods greatly adopted by the …

Encapsulation Of Probiotics By Cellulose Nanocrystal-Alginate Composite Beads For Ph Stimuli-Responsive Delivery, Akrip Jati

Graduate Theses and Dissertations

Microencapsulation has garnered significant interest, with oral probiotics delivery systems showing enormous potential to help restore the gut microbiome. This method holds vast potential to protect and release specific microbial strains to the desired target site (i.e., colon) within the gastrointestinal tract (GIT). However, current encapsulation methodologies, utilizing either synthetic or biological materials as carriers, encounter challenges such as suboptimal encapsulation efficiency, premature probiotic release, and inadequate control over release kinetics. In this work, hydrogel microsphere (HM) composites of different cellulose nanocrystal (CNC) forms (i.e., colloidal (c), and crosslinked (x)) and alginate (ALG) were used as advanced controlled release systems …

Employee Development And Employee Resilience In The Post-Covid-19 Workplace: A Quantitative Study Of High School Educators, Amy Keiser Maffei

Graduate Theses and Dissertations

The problem addressed by this research is the need for protective factors to support teacher resilience. Organizations that fail to develop employee resilience risk failing to enjoy the positive outcomes associated with it. Research-based methods to improve resilience may benefit organizations, including school districts. The purpose of this study was to examine the relationship between employee development provided by a school district and the resilience of its high school teachers in the post-Covid-19, in-person workplace. Conservation of Resources theory served as the framework to guide the research. Study participants completed a questionnaire with Likert-style response options, with items to assess …

Bactericidal Mechanism Of Peracetic Acid Against Salmonella Mediated By Reactive Oxygen Species, Mohammed Khalid Wheib Al-Doury

Graduate Theses and Dissertations

Peracetic acid (PAA) is extensively used as a bactericidal agent in poultry processing to reduce foodborne pathogens, including Salmonella enterica serotype Typhimurium (S. Typhimurium). Despite its widespread application, the exact mechanisms underlying its bactericidal effects, particularly the role of reactive oxygen species (ROS), remain incompletely understood. This dissertation examines the role of ROS in PAA-mediated bacterial killing and explores both genetic and metabolic factors that influence bacterial susceptibility to PAA. Findings from these studies have implications for enhancing the efficacy of PAA, thereby improving food safety practices in the industry.

The first study investigates ROS as a central component …

Cellulose–Starch Composite Aerogels As Thermal Superinsulating Materials, Safoura Ahmadzadeh, Angelina Sagardui, David Huitink, Jingyi Chen, Ali Ubeyitogullari

Chemistry & Biochemistry Faculty Publications and Presentations

The demand for sustainable packaging materials is rapidly increasing due to growing environmental concerns over the impact of plastic waste. In this study, biodegradable, porous, lightweight, and high-surface-area microcrystalline cellulose–starch (MCC-S) hybrid aerogels were synthesized via supercritical carbon dioxide (SC–CO₂) drying. The samples were generated using five different MCC-S weight ratios and characterized for their morphology, crystallinity, and structural and thermal properties. When MCC and S were used together, aerogels with superior properties were obtained compared to those made from each component individually. Specifically, the 1:2 MCC-S aerogel exhibited the highest porosity (97%), the lowest density (0.058 g/cm …

Gc-Ms Analysis And Evaluation Of Antioxidant, Anticancer, Cytotoxicity, And Hypoglycemic Properties Of The Libyan Moringa Oleifera Leaf Extract On Alloxan-Induced Diabetes In Mice, Osama Abdel-Hafeez Mohammed Al-Bedak, Ahlam Rashed, Seham T.M. Oskandali, Nouri Kushlaf, Amal Eishebani, Samira A. Alacrouk, Fadia T.M. Oshkandale, Manal Eisheli, Zahur R. Almesai, Ameerah Shaeroun, Steven L. Stephenson, Fuad Ameen

Biological Sciences Faculty Publications and Presentations

Libyan Moringa oleifera leaves were extracted using methanol, and the bioactive components' antibacterial, antioxidant, anti-inflammatory, and anticancer characteristics were assessed using gas chromatography mass spectrometry analysis (GC-MS). Moringa oleifera exhibited antioxidant activity, with an IC50 of 11.53 µg/mL. Wi38 cell line's viability decreased with increasing M. oleifera extract concentration, while its cytotoxicity increased with an IC50 of 393.41±7.77 μg/mL. Alloxan-induced diabetes model in Swiss albino mice was implemented. Three different doses (100, 200, or 300 mg/kg of mice body weight) of M. oleifera’s extract were evaluated for their effects on blood sugar concentration and the histology of the pancreatic islets. …

Genetic Diversity And Population Structure Of Tomato (Solanum Lycopersicum) From The Usda-Grin Germplasm Collection, Ibtisam Alatawi, Haizheng Xiong, Hanan Alkabkabi, Kenani Chiwina, Qing Luo, Kai-Shu Ling, Yuejun Qu, Renjie Du, Ainong Shi

Horticulture Faculty Publications and Presentations

The genetic diversity and population structure of tomato (Solanum lycopersicum) were investigated to support breeding strategies and germplasm conservation. A total of 276 accessions from the USDA-GRIN collection were analyzed using single-nucleotide polymorphisms (SNPs) generated through genotyping by sequencing (GBS). After stringent filtering, 5162 high-quality polymorphic SNPs were retained for analysis. Population structure analysis revealed three distinct genetic groups (Q1, Q2, and Q3) among the accessions. Accessions from the USA, Asia, and Central and South America were assigned to all three groups, while accessions from Europe and Oceania were predominantly clustered within Q2. Genetic diversity indices, including major …

Quantifying Temperature Effects On Development Rate And Plant Quality Of Compact Container-Grown Tomato, Morgan Humphrey, Ryan W. Dickson, Sonali Padhye

Horticulture Faculty Publications and Presentations

Mean daily temperature effects on plant development rates and quality were evaluated for compact container-grown tomato (Solanum lycopersicum). Compact tomato varieties ‘Siam’ and ‘Red Velvet’ were grown in greenhouses at 18 to 26 °C (Expt. 1) and 20 to 30 °C (Expt. 2) under supplemental high-pressure sodium lighting and 16-h photoperiod. The number of days to first open flower, first ripe fruit and from flower to ripe fruit were measured and development rates calculated by taking the reciprocal (e.g., 1/d). Temperature effects were predicted by fitting a linear (for first open flower) and a nonlinear exponential function (for …

Synthesis Of Chemical Fuels And Feedstocks From Co2 For Extraterrestrial Applications, Samuel Keith Conlin

Graduate Theses and Dissertations

The reduction of CO₂ into products for either the storage of renewable electricity or to act as a source of renewable feedstock for industry, is not economically feasible given the current costs of renewable energy. Significant amounts of work have gone into attempting to optimize both electrochemical and nonthermal plasma-based CO₂ reduction systems in an attempt to reduce side reactions and improve energy efficiency in order to meet cost feasibility targets. These techniques can also be adapted for In-Situ Resource Utilization (ISRU) contexts, which are far less sensitive to the cost of renewable energy yet have more strenuous …

Emotional Intelligence And Self-Direction Orientation: An Examination Of Non-Academic Factors In Post-Pandemic Community College Students In Kansas And Missouri, Ashley Rader

Graduate Theses and Dissertations

Post-pandemic learners face academic and non-academic challenges due the educational disruption caused by the COVID-19 virus. ACT college admissions test scores dropped to a 30-year low in 2023, falling the most significantly and rapidly during and after the pandemic (ACT, 2023) and recovery from these childhood and adolescent learning deficits has not been seen to date (Betthäuser et al., 2023). Research on non-academic factors, not as widely studied as academic factors, is crucial to understand where these learners’ deficits further lie. Two of those factors – emotional intelligence and self-direction orientation – were the key concepts of interest in this …