Digital Commons Network^™

Food Safety Risk In An Indoor Microgreen Cultivation System, Gina Marie Misra

Graduate Theses and Dissertations

Microgreens are immature sprouts of edible plants, sharing some similarities with sprouted seeds and petite leafy greens. Since they are most often grown in containers in buildings or greenhouses, they present a new area for food safety research at the intersection of the built environment and produce farming. Contamination by human pathogens has been extensively studied in other types of produce typically eaten raw, including sprouted seeds, which have been implicated in numerous outbreaks of salmonellosis over the last several decades. There is a paucity of knowledge about the microgreen sector of the fresh-cut industry; thus, it was determined that …

Improvement Of Geometric Quality Inspection And Process Efficiency In Additive Manufacturing, Yu Jin

Graduate Theses and Dissertations

Additive manufacturing (AM) has been known for its ability of producing complex geometries in flexible production environments. In recent decades, it has attracted increasing attention and interest of different industrial sectors. However, there are still some technical challenges hindering the wide application of AM. One major barrier is the limited dimensional accuracy of AM produced parts, especially for industrial sectors such as aerospace and biomedical engineering, where high geometric accuracy is required. Nevertheless, traditional quality inspection techniques might not perform well due to the complexity and flexibility of AM fabricated parts. Another issue, which is brought up from the growing …

An Evaluation Of Biopesticide Combinations On Yield Performance And Disease/Arthropod Control Of Strawberries Grown In High Tunnel Plasticulture Production Systems In Arkansas., Karlee B. Pruitt

Graduate Theses and Dissertations

This two-year study investigated combinations of biopesticides to determine impacts on strawberry fruit marketable fruit yields, and effectiveness in controlling strawberry pests in a high tunnel production system at the University of Arkansas, Division of Agriculture Research and Extension Center in Fayetteville, Arkansas. Two strawberry cultivars Fragaria × ananassa (Duch.), Camino Real and Sweet Sensation were grown in a high tunnel from early-October to mid-May for two consecutive growing seasons, (2017-18 and 2018-19) with six treatment combinations of biopesticides including an untreated (water) control, nutrient spray and selected biological based fungicides and insecticides, arranged into a split-plot randomized block design. …

A Putative Cystathionine Beta-Synthase Homolog Of Mycolicibacterium Smegmatis Is Involved In De Novo Cysteine Biosynthesis, Saroj Kumar Mahato

Graduate Theses and Dissertations

Mycobacteria include serious pathogens of humans and animals. Mycolicibacterium smegmatis is a non-pathogenic model that is widely used to study core mycobacterial metabolism. This thesis explores mycobacterial pathways of cysteine biosynthesis by generating and study of genetic mutants of M. smegmatis. Published in vitro biochemical studies had revealed three independent routes to cysteine synthesis in mycobacteria involving separate homologs of cysteine synthase, namely CysK1, CysK2, and CysM. However, in vivo data were lacking. The M. smegmatis genome encodes only a CysM homolog and lacks orthologs for CysK1 or CysK2. The gene that codes for CysM is a part of an …

Characterization Of Avidin And Case9 Single Protein Molecules By A Solid-State Nanopore Device, Haopeng Li

Graduate Theses and Dissertations

The shape and charge of a protein play significant roles in protein dynamics in the biological system of humans and animals. Characterizing and quantifying the shape and charge of a protein at the single-molecule level remains a challenge. Solid-state nanopores made of silicon nitride (SiNx) have emerged as novel platforms for biosensing such as diagnostics for single-molecule detection and DNA sequencing. SSN detection is based on measuring the variations in ionic conductance as charged biomolecules translocate through nanometer-sized channels driven by an external voltage applied across the membrane. In this paper, we observe the translocation of asymmetric cylindrical structure CRISPR-Cas9 …

From Start To Finish: Predicting Enrollment And Attainment In Arkansas Postsecondary Education, Katherine Kopotic

Graduate Theses and Dissertations

Postsecondary education has become a popular option for students, as evidenced by increases in enrollment over the last two decades. However, while enrollment has increased, completion has not. It is therefore important to investigate the factors that could lead to students’ enrollment, persistence, and completion of college. This dissertation examines two broad topics over three chapters. Chapters 1 and 2 focus examine the impact of a policy change that resulted in backloading the award disbursement of a state-wide merit-based scholarship program in Arkansas on college enrollment and success. Chapter 3 examines factors that influence the predictive nature of high school …

Cloning, Protein Expression, And Characterization Of Interleukin 1 Alpha, Musaab Habeeb Ali Al Ameer

Graduate Theses and Dissertations

Recombinant DNA technology and the ability to produce recombinant proteins have significantly changed the world of pharmaceutical market. Recombinant DNA technology using E. coli cells has successfully produced many therapeutic proteins. In this study, the designed tag Ark-RUBY-tag facilitates rapid, and reproducible purification of recombinant proteins expressed as inclusion bodies in E. coli cells. Purification of Ark-RUBY-fused recombinant protein(s) can be obtained by using imidazole fractions. Target protein can be easily removed from the Ark-RUBY-tag by enzymatic cleavage. Ark-RUBY-fused recombinant proteins can be quantitatively detected using polyclonal antibodies. Ark-RUBY-tag can be used to purify small peptides. By using Ark-RUBY-tag, purified …

Teacher Turnover And Teacher Retirement, Dillon Fuchsman

Graduate Theses and Dissertations

Teachers have an important impact on students in the short- and long-term, but only teachers’ experience consistently predicts high teacher quality. This dissertation, divided into three chapters, investigates two topics that are related to teachers’ experience levels: turnover and retirement.

The first chapter studies the relationship between voluntary beginning teacher turnover and teachers’ levels of conscientiousness. It uses the data from the Beginning Teacher Longitudinal Study and the effort that teachers put on a survey taken during their first year in the profession as a proxy for teachers’ levels of conscientiousness. The results of this chapter indicate that teachers putting …

Hydroponic And Soilless Culture Systems And Transplant Practices Influence Production Of Basil (Omicum Basilicum L.), Samuel Warren Edward Doty

Graduate Theses and Dissertations

Two controlled-environment greenhouse experiments evaluated (1) plant growth and morphology of basil (Omicum basilicum L.) grown in three different hydroponic and soilless substrate systems and (2) seedling tray cell-count and transplant date into hydroponic culture effects on basil growth and yield at harvest. For the first experiment, four basil cultivars (‘Genovese’, ‘Mrs. Burns Lemon’, ‘Sweet Thai’, and ‘Cinnamon’) were grown in deep flow technique (DFT) hydroponics, nutrient film technique (NFT) hydroponics, and a novel shallow aggregate ebb-and-flood (SAEF) soilless substrate system and were harvested after 21 d. Plant yield and morphological characteristics measured at harvest included shoot fresh mass, shoot …

Markets And Supply Chains: An Investigation Of The Institutions Influencing The Farm-Supply Chain Interface, Jessica L. Darby

Graduate Theses and Dissertations

Farm-level operations have lasting and amplified impacts that promulgate the entire supply chain, and the farm is increasingly in the forefront of today’s headlines on topics such as social responsibility, environmental sustainability, traceability, and food safety. Despite its significance, however, the farm remains a ‘black box’ and has traditionally operated independently with little information-sharing, trust, or collaboration with buyers downstream. This dissertation begins to unpack this ‘black box’ by employing different methodologies to identify the factors influencing exchange in the farm-supply chain interface. In Essay 1, I examine why the farm continues to be a challenge for ‘traditional’ collaborative approaches …

An Exploration Of The Experiences Of Faculty With Disabilities In A Research University In The South, Gonzalo Camp

Graduate Theses and Dissertations

While diversity and inclusion has become a benchmark for universities all around the country, faculty with disabilities remain in the margins of higher education discourse and are a neglected population across the spectrum of academia. This thesis aims at exploring the experiences of faculty with disabilities at a specific research 1 university in the South. Semi-structured interviews were conducted with five faculty members who self-identify as having a disability. Four themes emerged from this study: able-bodied lens, fear, social isolation, and coping mechanisms. Building on the existing literature, these findings offer new information to expand the knowledge on the challenges …

Design Of Submicron Structured Guided-Mode-Resonance Near-Infrared Polarizer, Marzia Zaman

Graduate Theses and Dissertations

The objective of this research is to design a larger submicron linear polarizer in the near-infrared wavelength range with a wide bandwidth which can be fabricated using the conventional thin-film microfabrication technology to reduce cost. For this purpose, a gold (Au) wire-grid transmission-type transverse-magnetic (TM) polarizer and a silicon (Si) wire-grid reflection-type TM polarizer, were designed using the guided-mode-resonance filter. The Au wire-grid TM polarizer of 700nm grating width and 1200nm grating period has 95% transmittance at 2400nm, more than 1000nm resonance peak bandwidth, and an extinction ratio (ER) of around 300 with a moderated level of sidebands. The 700nm …

The Effects Of Auditory And Olfactory Cues On Visual Attention Toward Food Images Under Acute Stress, Reza Moltaji

Graduate Theses and Dissertations

Psychological stress has been shown to increase preference for high calorie foods containing high levels of sugar and fat. Since excessive intake of high calorie foods may increase potential risk of obesity and other relevant health issues, relieving psychological stress may help in maintaining a balanced diet and good health status. Although a variety of strategies for relieving psychological stress has been suggested, little attention has been paid to regarding whether such strategies can result in balanced diets. Since music therapy and aromatherapy have proven popular approaches to relieving psychological stress, this thesis aimed at determining whether listening to music …

Evaluation Of The Arkansas Double Up Food Bucks Program, Colton G. Henderson

Graduate Theses and Dissertations

Fruit and vegetable consumption is particularly low in Arkansas with only a small percentage of residents meeting daily recommendations. Arkansas also has one of the highest percentages of food insecurity and obesity in the United States. Low-income households, such as Supplemental Nutrition Assistance Program (SNAP) recipients, are at a higher risk of these issues. Financial assistance programs have been implemented to help in aiding these problems. The Double Up Food Bucks program (DUFB) is one of these programs. DUFB provides matching financial vouchers for SNAP benefits recipients spend on fresh local produce at participating grocery stores and farmers’ markets. The …

An Isotopic Assessment Of Late Prehistoric Interregional Warfare In The Southcentral Us, John R. Samuelsen

Graduate Theses and Dissertations

Skull burials are found all over the world. The cause of such ancient Native Americans deposits often lead to disagreement among scholars torn between warfare and ancestor veneration. One skull-and-mandible deposit, representing at least 352 people (A.D. 1253-1399), was uncovered at the Crenshaw site, a multiple-mound Caddo ceremonial center in southwest Arkansas. Most previous research suggested they were victims of interregional warfare from the Southern Plains or Mississippi Valley. One previous study hypothesized that this was a Caddo burial practice which expanded during the Middle Caddo period (A.D. 1200-1500) due to the adoption of maize as a staple and a …

The Effects Of Group Fitness Classes On Self-Efficacy, Katherine Dalton

Graduate Theses and Dissertations

Self-efficacy is one of the largest predictors of behavior, when related to exercise studies have shown that self-efficacy can predict drop-out rates within six months of being an exercise program (Middelkamp, et. al., 2016; Sallis, et. al., 1988). College students have the biggest decline in physical activity when compared to other stages of life (Buckworth, 2001; Grubbs & Carter, 2002). University recreation centers provide group fitness classes for students to promote physical activity. Minimal research has been done to show the impact that group fitness classes has on student life. This study aimed to show the impact of group fitness …

Quantifying Greenhouse Gas Emissions And Ammonia Volatilization From Soil Amended With Excreta From Ruminants Fed Alternative Forage-Based Diets, Samuel Park

Graduate Theses and Dissertations

Forage-based ruminant diets supplemented with condensed tannins or polyphenolic-containing legumes may alter nitrogen (N) metabolism in the animal and reduce gas emissions from soil receiving excreta. The objective of the study was to determine if soil receiving urine or manure from sheep fed forage diets supplemented with condensed tannin or polyphenolic-containing legumes would decrease N gas emissions. Two field trials were conducted: in the first trial, sheep were fed alfalfa (Medicago sativa L.) silage diets supplemented with 0, 9, 18, or 27% sericea lespedeza (Lespedeza cuneate [Dumont de Courset] G. Don) (n = 4). In the second trial sheep were …

A Comparative Taxonomic And Diversity Study Of Litter-Associated Fungi In Northwest Arkansas Forests, Rajaa Abdulrazzaq Abbas Al Aanbagi

Graduate Theses and Dissertations

Fungi are taxonomically the most species-rich group of organisms on the earth, ecologically occupy distinctive niches and interact with diverse other organisms throughout their biogeographic distributions and functionally play key roles through their various lifestyles. Plant litter, in particular, is a keystone component in ecosystems and provides heterogeneous microhabitats for the often overlooked litter-decomposing fungi and other organisms on the floor of temperate deciduous forests. Litter fungi involve indirect interactions with the plant, soil and whole food web network. However, the community structure and functions of litter-associated fungi as well as patterns of species richness distributed across various litter microhabitats …

Effects Of Parental Migration On Education And Personality: Evidence From Indonesia, Kyle Sullivan

Graduate Theses and Dissertations

In developing countries, migration can be an important method for many families and households to produce additional income via remittances in order to meet their needs or invest in their children. However, migration is a dynamic process and the absence of a parent can have negative effects on those children left behind. This paper explores how parental migration is associated with their children’s years of education completed and how these associations are heterogenous by family compositions in Indonesia. I use a longitudinal dataset which allows for parents’ migrations to be attributed throughout an individual’s childhood to measure the cumulative impact. …

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu

Graduate Theses and Dissertations

In this work, we have made and characterized a pair of immunobiosensors for detecting the green fluorescent protein (GFP) in an aqueous matrix. An anti-GFP antibody-based biosensor was assembled to detect GFP, while a novel peptoid (N-substituted oligomers of glycine designated as IOS-1) biosensor was also assembled for GFP detection. A quartz crystal microbalance (QCM) gold sensor was used as the supporting substrate for self-assembly of the immunobiosensors. Gravimetric measurements of the QCM gold sensor during immunobiosensor construction and operation were available in real-time using a QCM instrument. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Fluorescence microscopy were used …

College Student Changing Attitudes And Beliefs About The Nature Of And Teaching Of Mathematics And Science, Stephen R. Skinner

Graduate Theses and Dissertations

With an estimated 17.3 million STEM jobs in the US, there exists a need for a STEMready workforce that is science literate with positive attitudes and beliefs toward the learning and teaching of mathematics and science (Graf, Fry, & Funk, 2018). However, the US has seen a steady decline in the number of high school students interested in STEM-related fields with only 16% of interested students with proven proficiency in mathematics and science and are ready to enroll in college STEM programs (ACT, 2017; Osborne & Dillon, 2008; Stake & Mares, 2001). With the decline in student interest, the US …

Associations Of Sex, Gender, And Gender Role Beliefs With Mental Health Attitudes, Ariel Erazo

Graduate Theses and Dissertations

Mental health stigma is a strong deterrent for individual with mental illness utilizing mental healthcare. Individuals living with a mental illness experience shame and marginalization due to stigma. Stigma is perpetuated through stereotypes created and used by people in the majority. Studies have been done to assess individual’s attitudes toward mental healthcare seeking in regards to gender, age, race, and profession. This study aimed to look at traditional gender role beliefs, sex, and gender expression as predictors of individual’s mental health attitudes and individual’s views of mental health norms. Using a cross-sectional survey, 392 participants completed scales that included the …

The Effect Of Breakfast Macronutrient Composition In Children Ages 7-17 Years Old As A Potential Method To Combat Childhood Obesity, Angela M. Tacinelli

Graduate Theses and Dissertations

The prevalence of childhood overweight and obesity is an ongoing concern. Currently, approximately 20% of children in the United States are obese. While obesity was once regarded merely as excessive adiposity within the body, it is has emerged as a major risk factor for chronic diseases such as metabolic syndrome, type 2 diabetes, and cardiovascular disease. Obesity is multifactorial in nature. Weight gain can result from an energy imbalance in the body due to excess energy intake (calories in) and decreased energy expenditure (calories out). Identifying methods to combat obesity is essential. Nutritional intervention may be a strategy to help …

An Exploration Of Faculty With Disabilities In Social Work Programs, Kelly Dundon

Graduate Theses and Dissertations

Disability is a unique dimension of diversity, yet structural, social and attitudinal barriers can make meaningful workforce participation difficult for individuals with disabilities. Faculty with disabilities (FWD) are a particularly underrepresented population in academia, and even more so in social work programs. Based on this under-representation and a concern for the lack of attention this population has received, this project will explore a subset of this group. This thesis will focus on faculty with disabilities, first by looking into the scant research pertaining to FWD, then presenting the data from a qualitative study and demographic survey. Implications for policy, practice …

An Interdisciplinary Study To Understand Treatment Seeking Behavior Among Female Survivors Of Anorexia Nervosa, Meaghan Victoria Tipton

Graduate Theses and Dissertations

This study was done to examine what psychosocial factors influence treatment seeking behavior among female survivors of eating disorders. This study uses a mixed methods survey consisting of open-ended item questions regarding treatment experience and social environment, and close-ended items to measure constructs from the Health Belief Model. Fourteen participants were recruited for this study to retrospectively detail their experiences of treatment during their eating disorder. All fourteen participants identified as Caucasian, thirteen identified as female, one identified with other gender, each with a history of medically diagnosed anorexia nervosa. The mean of age of current participants was 29.46, and …

The Impact Of Social Media On The Social Lives Of People With Visual Impairment (Facebook Groups As A Case Study), Itto Outini

Graduate Theses and Dissertations

This present research seeks to provide a more comprehensive understanding of why people with visual impairment use social media. I investigate this question using uses and gratification (U&G) Theory, which was developed by Katz, Blumler, & Gurevitch (1974). The theory explains what people do with media and why. The purpose of this study is twofold: it seeks to document reasons people with visual impairment use Facebook and it endeavors to reveal which variables can influence users’ decisions to use one social media platform instead of another. In particular, I am interested in determining factors motivating users with visual impairment to …

An Evaluation Of Unmanned Aircraft Systems' Ability To Assess Stripe Rust In Large Wheat Breeding Nursies, Jamison T. Murry

Graduate Theses and Dissertations

Stripe Rust (Puccinia striiformis f. sp. tritici) is a foliar disease that significantly impacts global wheat production, and resistant cultivars provide the most efficient method of control. High-throughput phenotyping using unmanned aircraft systems (UAS) offers a potentially more efficient method for field-based phenotyping compared to visual assessment. Here we tested the ability of remote sensing to predict stripe rust severity in a diverse population of 594 soft red winter wheat lines, planted in single-rows, and evaluated them by visually rating stripe rust intensity and remotely using the dark green color index (DGCI), normalized difference vegetation index (NDVI) and blue NDVI. …

Use Of Acetolactate Synthase-Inhibiting Herbicides In Inzen Grain Sorghum (Sorghum Bicolor L. Moench Ssp. Bicolor), Hunter Bowman

Graduate Theses and Dissertations

Grain sorghum is typically grown as a rotational crop in Arkansas because of its many benefits, one being the effective control of Palmer amaranth through the use of atrazine. However, limited options exist for postemergence (POST) control of weedy grasses within the crop. Inzen™ grain sorghum is the result of a nicosulfuron resistant weedy sorghum biotype cross-bred with a commercial line of grain sorghum. Inzen™ allows for safe use of over-the-top applications of nicosulfuron within the crop. Nicosulfuron is an acetolactate synthase (ALS)-inhibiting herbicide, which has historically been used in corn for control of weedy grasses. Experiments were conducted in …

Journalism Vs. Activism: How The Social Impact Of Journalism Has Evolved, Kathryn Serrano

Graduate Theses and Dissertations

The aim of this study was to question the objectivity norm that arose in journalism in the 20th century, and analyze what objectivity means today in the context of investigative journalism. This study examined the mission statements and objectives of the investigative nonprofits The Marshall Project and Injustice Watch, which are two publications with specific mission statements that cover the United States criminal justice system. The examination of these nonprofits helps explore a question of where the line is drawn between journalism and activism. The researcher interviewed 25 journalists from mainstream media outlets, the nonprofits discussed above, and other investigative …

Evidence-Based Social-Emotional Learning And Its Influence On Teachers’ Perception Of Student Behavior: An Analysis Of Ruler And The Anchors Of Emotional Intelligence, Brent B. Harrington

Graduate Theses and Dissertations

This study was designed to assess the extent by which an evidence-based Social-Emotional Learning (SEL) program influenced teachers’ perception of students’ behavior in a small and diverse PK – 8 school district in Westchester County, NY. Specifically, the researcher evaluated the Anchors of Emotional Intelligence and the RULER framework to determine its impact on school climate as viewed from the perspective of staff in the district. Prior to commencing the study, the researcher recognized the negative staff narrative around student behavior in the district as a significant problem of practice that was observable, actionable and high leverage.

This mixed-methods study …