Digital Commons Network^™

Enzymatic Degradation Of Microcystin-Lr By Microcystinase (Mlra), Faisal Alqhtani

Graduate Theses and Dissertations

Microcystin-LR (MC-LR) is affecting the water supply worldwide. Hence, a way to eliminate this toxin is an essential target. In this study, successful cloning of the mlrA gene and producing MlrA enzyme that can degrade the cyclic MC-LR to linearized MC-LR was done. MlrA protein was expressed in Escherichia coli BL-21 (E. coli). Also, enhancing the MlrA yield by adding nickel to LB media was a success in producing more MlrA enzyme from the same volume. Even though the enzyme showed no activity after adding Ni, the enzyme was expressed at a higher yield. Furthermore, it was to investigate adding …

Effects Of Extrinsic And Intrinsic Factors On Meat Quality And Muscle Biology Of Livestock, Yongjie Wang

Graduate Theses and Dissertations

In order to improve the meat quality of livestock, intrinsic and extrinsic factors that impact meat quality have been studied for a long time to optimize production quality. Nutrition, breed, and environment are the three most common factors to improve meat quality and muscle growth. The objective of this thesis is to perform a horizontal comparison of the effects of crude protein levels, breeds, and topsoil on the growth performance, muscle development, and meat quality of livestock, and also a longitudinal analysis using RNA-seq, RT-qPCR, and Western-blot to investigate the changes in genes and proteins related to muscle growth, and …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Nutrient Uptake And Management Strategies In Recirculating Hydroponic Systems, Lauren Leigh Houston

Graduate Theses and Dissertations

Nutrient management in recirculating hydroponic systems requires the periodic replenishment of water and nutrients to the nutrient solution reservoir. Common nutrient management strategies, such as replenishing the reservoir with fresh solution and maintaining a constant solution electrical conductivity (EC), can lead to ion accumulation and nutrient imbalances since nutrients are taken up by roots and depleted from solution at different rates. To avoid nutritional disorders, commercial growers typically dump and replace the hydroponic solution periodically, which is wasteful and has an economic cost. A potential alternative is to specially formulate the nutrient replenishment solution to balance the supply of nutrients …

The Impact Of Corporal Punishment For Timorese High School Graduates, Veronica Godinho Pereira

Graduate Theses and Dissertations

This research examines the impacts of corporal punishment for Timorese high school graduates. Physical punishment is a pervasive method of disciplining students and children used in Timor-Leste because it has been such a tradition (UNICEF 2017). Few researchers have attempted to analyze the negative impacts of corporal punishment and possible gender differences; there is no known research on the impacts of corporal punishment in Timor-Leste. This study uses an in-depth interview method, where data were collected from 26 Timorese high school graduates composed of both men and women from both private and public schools in Timor-Leste. The ages of the …

Role Of Sex Differences On Cancer Cachexia Progression And Fibrosis During Cancer Cachexia Development, Wesley Haynie

Graduate Theses and Dissertations

Cancer cachexia is a multifactorial wasting syndrome characterized by losses in bodymass >5% and occurs in approximately 80% of all cancer patients. Chronic inflammation and fibrosis play roles in cancer cachexia and a greater understanding of these contributing pathways to this pathology will pave the way for potential therapeutic avenues. While inflammation and fibrosis have been researched in various models of cancer cachexia, little to no studies have been performed in both sexes as most previous studies focus on males. PURPOSE The purpose of these studies is to investigate the role of fibrosis on cancer cachexia development as well as …

Development And Evaluation Of Models For Hatchery-Mediated Infection Of Neonatal Broiler Chicks, Brittany Danielle Graham

Graduate Theses and Dissertations

Formaldehyde fumigation has been used to control the microbial load in commercial hatch cabinets. The hatch cabinet environment promotes replication and dissemination of both apathogenic and pathogenic microorganisms. As the microbial load increases during the hatching phase, formaldehyde eliminates airborne microorganisms circulating in the hatch cabinet environment. Due to the hazardous properties of formaldehyde, non-toxic alternatives to formaldehyde fumigation to control the microbial bloom in hatch cabinets are needed. The objectives of the present dissertation were to develop challenge models using singular or multiple microorganisms associated with the microbial bloom to simulate contamination that occurs in commercial hatch cabinets. Initially, …

Symbolism Or Substance: Factors Influencing Campus Messaging Decisions And Their Alignment With Institutional Values, Laura Herzog Jacobs

Graduate Theses and Dissertations

Historically, institutions of higher education (IHE) have been cautious and slow in making changes. Yet in today’s fast-paced and dynamic world of content availability and information flow generated by 24-hour news cycles and the ubiquity of social media present a challenging reality for colleges and universities in their public relations and communications approaches (Sands & Smith, 2000). Creating a harmonious and agile approach to managing these responsibilities against the backdrop of an incessant flow and public demand for information, including responses to national events often with seemingly little or no connection to the institution, suggested a need to examine the …

How Are Agricultural Research Projects Conceiving Innovation? An Assessment Of The European Union Multi-Actor Projects, Samuel Brea Martinez-Collado

Graduate Theses and Dissertations

Horizon research programs are the European Union’s lighthouse for innovation and research concerning the agri-food chain, the management of natural resources, and the bioeconomy. Their innovation strategy approach is one that pursues the practical application of the research via the collaboration of all actors involved. Such strategy is the reflection of a Multi-Actor Approach as their procedure to enhance innovation. This paper presents the main trends and directions 101 Multi-Actor Projects (MAPs) are following on said approach towards innovation. The analysis is based on the use of well-defined “pathways” and “measures” proposed in the Guidelines for Evaluation of Innovation in …

Evapotranspiration In Mid-South Rice Production, Colby Wade Reavis

Graduate Theses and Dissertations

Rice provides much needed sustenance to a large portion of the global population, particularly in the developing world. With stress placed on food production systems under the reality of climate change and an increasing global population, rice production systems require solutions to a number of issues, including a limited water supply. As producers explore new strategies for conserving local water resources to continue to maintain yields, new irrigation strategies and technologies are being developed and validated for use at commercial production scales. Alternate wetting and drying (AWD) is an irrigation practice that provides water savings through the capture of rainfall …

New Titanate Bioceramic Nanomaterials For Drug Delivery And Controlled Release, Seaab Imad Sahib

Graduate Theses and Dissertations

Nanomaterials have attracted much attention for biomedical applications due to their unique characteristics that are proven to be potential in cell sensing, drug delivery, biological membrane penetration, biocompatibility, and tissue adhesion. The outcomes of this dissertation presented in chapter III-V mainly discuss new approaches in drug delivery, cellular uptake improvement, and neuronal regeneration and protection using a well-optimized titanium-based nanomaterial. In particular, Chapter III summarizes the impact of two different versions of the titanate nanowires on ameliorating the delivery of the antimicrobial and anticancer drug in vitro. Those drugs were loaded on the surface of the fabricated nanowires and characterized …

A Double-Sided Stack Low-Inductance Wire-Bondless Sic Power Module With A Ceramic Interposer, Si Huang

Graduate Theses and Dissertations

The objective of this dissertation research is to develop a novel three-dimensional (3-D) wire bondless power module package for silicon carbide (SiC) power devices to achieve a low parasitic inductance and an improved thermal performance. A half-bridge module consisting of 900-V SiC MOSFETs is realized to minimize stray parasitic inductance as well as to provide both vertical and horizontal cooling paths to maximize heat dissipation. The proposed 3-D power module package was designed, simulated, fabricated and tested. In this module, low temperature co-fired ceramic (LTCC) substrate with vias is utilized as an interposer of which both top and bottom sides …

Economic Potash Fertilizer Rate Recommendations, Kimberly B. Oliver

Graduate Theses and Dissertations

This thesis is comprised of two studies that estimate profit-maximizing potassium (K) fertilizer application rates for various crops across different time periods. Estimation of profit-maximizing fertilizer-K rate (K*) for both studies considered the initial soil test level of K (STK) and yield response information, as traditional recommendations do, and added crop price and the cost of fertilizer. Profit maximum occurs where the marginal revenue from additional yield is equal to the marginal cost of applying an additional unit of fertilizer-K. The first study calculated K* for corn (Zea mays) and cotton (Gossypium hirsutum) and compared results to previous studies on …

Substance Use And Psychological Distress Correlates Of Sleep Quality Among College Students, Juanybeth Morales Ortega

Graduate Theses and Dissertations

Poor sleep quality in college students is a major problem associated with adverse health outcomes, cognitive performance, substance use, and psychological distress. Our study explored how substance use and psychological distress are associated with the sleep quality of college students. We analyzed secondary data collected in 2019 using a cross-sectional survey design. Measures included participants’ demographic characteristics, sleep quality using the Pittsburg Sleep Quality Index (PSQI), drug use, depression using the Patient Health Questionnaire-9 (PHQ-9), and suicidality. After excluding participants with missing information for sleep quality, a total of 555 students remained for the analysis. Our bivariate analysis found that …

Impact Of Planting Arrangement And Drill Row Spacing For Direct-Seeded, Delayed Flood Rice, Mary Jane Lytle

Graduate Theses and Dissertations

Direct-seeding is the most frequently utilized planting practice in Arkansas and Mid-South rice (Oryza sativa L.) production. Enhanced plant density and more rapid rice canopy formation may result from the implementation of innovative plant arrangements and spacings. Studies were initiated in 2019 and continued into 2020 to examine different cultural management practice experiments, including evaluating the impacts of planting arrangement, row spacing, and seeding rates on rice stand density, canopy coverage, grain yield, and milling yield. These small-plot trials were conducted at two locations, a silt loam site and a clay site, representative of soils produced to rice in eastern …

Divergent Selection For Water Conversion Ratio In Broiler Populations, Joseph Hiltz

Graduate Theses and Dissertations

Water scarcity is a global reality and with the anticipated population growth, freshwater resources will be further strained to meet both human needs and agriculture applications. To ensure a water sustainable and food secure future, all aspects of agriculture must become more efficient. Two strategies were explored. The potential of improving water efficiency in broilers was examined. The first strategy was to develop a more efficient and accurate method for measuring water consumption/inputs in agriculture. To date, water measuring technology has lacked the necessary sophistication to assure accuracy and repeatability of low flow water usage.

After establishing a low flow …

Evaluation Of Two Neonatal Challenge Models For Broiler Chickens And Their Effects On Early Performance Parameters, Callie Selby

Graduate Theses and Dissertations

Formaldehyde fumigation in poultry hatch cabinets has been utilized for sanitation of hatching eggs for over a century. Formaldehyde is utilized to minimize pathogenic microbes on the surface of the egg as well as the microbial bloom during the hatching process. While formaldehyde is effective, its use is regulated in the United States and Europe due to its carcinogenic nature. Formaldehyde has been shown to damage the cuticle of the egg, cause embryonic death, and damage the epithelial lining of the respiratory tract of freshly hatched chicks, predisposing them for respiratory infection. Alternatives for formaldehyde fumigation must be identified and …

Investigating Effects Of Microenvironmental Stress On Cell Metabolism Using Multiphoton Imaging, Lisa Rebello

Graduate Theses and Dissertations

Resistance to therapy in cancer is a major cause of poor prognosis in patients. Tumor hypoxia plays an active role in mediating treatment resistance and has been linked to metastases and metastatic potential in cancer. Our research focused on three objectives: i) To understand metabolic effects of chronic and intermittent hypoxia in murine breast cancer cells and its affiliation with metastatic potential ii) To identify the metabolic changes associated with radiation therapy in a panel of radiosensitive and radioresistant human head and neck cancer cells and iii) to monitor the changes in cell metabolism associated with gain of treatment resistance. …

Genome-Wide Analyses Of Genomic Variation Regulating Differential Stress Responses In Japanese Quail, Steven Anthony Shumaker

Graduate Theses and Dissertations

As consumer demands for poultry grow, producers work to improve bird productivity in both meat and egg production. This endeavor is multifaceted, as many different factors play a part in influencing the productivity of birds, including environmental conditions, overall health, and genetic potential. One aspect controlled for in all aspects of poultry production optimization is stress management. Mitigation of stress is of primary concern to producers, as improper stress management can have many deleterious effects on chickens. Stress management requires an understanding of poultry stress responses and their physiological mechanisms, which can be more deeply understood through genomic analysis. Chapter …

Teacher And Staff Perception Of School Climate: A Case Study, Michael Shane Hampton

Graduate Theses and Dissertations

The purpose of this study is to determine how different public-school teachers and staff perceive school climate at an achieving public middle school. The research sought to find relationships between teacher sub-groups and other staff members, and how they perceived the school climate, either negatively or positively. The researcher believed that there would be a positive perception of school climate, which coincided with high student achievement. Additionally, it was believed that there would be no relationship between teacher types or demographics, and how the climate would be perceived among the different groups. This paper also presents a review of the …

Deciphering Chemomechanical Couplings In Proteins Using Microsecond-Level Molecular Dynamics Simulations, Vivek Govind Kumar

Graduate Theses and Dissertations

All-atom molecular dynamics (MD) simulations combine the high temporal resolution of experimental methods like smFRET and spatial resolution of methods like x-ray crystallography, to provide a detailed dynamic picture of biomolecular processes. Here, microsecond-level atomistic MD simulations have been used to characterize chemomechanical couplings in human fibroblast growth factor 1 (hFGF1) and the spike proteins of SARS CoV-1 and SARS-CoV-2. hFGF1 is a globular signaling protein that is involved in several physiological processes ranging from cell proliferation to wound healing. Experimental studies have previously described the low proteolytic and thermal stability of hFGF1, in addition to the stabilizing role of …

Precise Nitrogen Recommendations Improve Economic And Environmental Outcomes In Arkansas Rice Production, Cristin Roberts

Graduate Theses and Dissertations

Soil testing has become an increasingly important tool in making agronomically efficient production management decisions. N-STaR is a N test used in rice production and is unique in its ability to selectively quantify soil organic-N compounds which are readily mineralizable for plant N uptake and contribute to growth and yield. This study uses historical (2002–2018) adoption rates of N-STaR, which is funded through Rice Checkoff funds, to calculate the total cost savings from N-STaR adoption. These cost savings alone would be the “typical” benefits used in a benefit-cost ratio of a public ally funded research program like N-STaR. However, we …

The Role Of Sex: An Analysis Of U.S. Attitudes Toward Climate Change, Chloe Riggs

Graduate Theses and Dissertations

This study analyzes the intersection of sex, environmental risk perception of climate change, and feminism. More specifically, with a sample size of 8,280 respondents from the American National Election Studies (ANES) 2020 Times Series Study, this research examines the relationship between pro-environmental attitudes and sympathy for feminism, controlling for sex, as well as if a measure of sympathy for feminism influences pro-environmental attitudes, controlling for demographic (age, education, race, sex, and income) and political preference (political ideology and party affiliation) variables. Previous literature strongly supports a sex gap in risk perception, a pattern known as the White Male Effect (WME) …

Examining The Relationship Between Library Services Use And Fall-To-Fall Retention In Community College Libraries, Eric Deatherage

Graduate Theses and Dissertations

Community college libraries exist to support institutional outcomes. One such outcome is student retention. This study’s purpose was to fill the gap in the literature at the community college level, proposing that a model including all library service use types would explain variance in student retention beyond that explained by total library financial expenditure. Services included were numbers of physical materials circulated, digital books circulated, e-serials used, reference transactions, library presentations, attendees at presentations, gate counts, and interlibrary loan materials borrowed. Additionally, it was proposed that the relationship between gate counts of physical entry into the library and student retention …

Effects Of Localized Oxygen Production By Electrolysis On The First-Generation Glucose Sensor Response, Nandita Halder

Graduate Theses and Dissertations

Glucose sensors are very important for detecting blood glucose both in vitro and in vivo. First-generation glucose biosensors were based on the glucose oxidase (GOx) enzyme using molecular oxygen as the electron acceptor and therefore oxygen dependent. Unfortunately for in-vivo work, oxygen in the body is variable and limited. Alternative approaches to overcome the oxygen dependency came with their own limitations. The widely used and commercially available ex-vivo glucose test strip uses a mediator in place of oxygen to free it from oxygen dependency. The mediator-based technology, in most cases cannot be transferred to in vivo applications due to the …

The Electrification Of The Kitchen: On The Energy Consumption Of Common Electric Cooking Appliances, Hozen Ricchie Rose Asok Rose

Graduate Theses and Dissertations

In developed countries, electricity has been gaining popularity as a source of energy for meal preparation. Utilizing electricity produced from renewable resources along with efficient electrical cooking appliances could result in sustainable clean cooking. The first objective of this research was to study the efficiency of common electrical cooking appliances—namely induction, resistance plate, resistance coil, infrared, and electric pot— by the water boiling test and the simmering test. The induction and electric pot were observed as the most efficient devices for the water boiling test. For simmering, which mimics many cooking processes, the electric pot and resistance coil were the …

Component Damage Source Identification For Critical Infrastructure Systems, Nathan Davis

Graduate Theses and Dissertations

Cyber-Physical Systems (CPS) are becoming increasingly prevalent for both Critical Infrastructure and the Industry 4.0 initiative. Bad values within components of the software portion of CPS, or the computer systems, have the potential to cause major damage if left unchecked, and so detection and locating of where these occur is vital. We further define features of these computer systems and create a use-based system topology. We then introduce a function to monitor system integrity and the presence of bad values as well as an algorithm to locate them. We then show an improved version, taking advantage of several system properties …

A Focused Evaluation Of Sales Employees' Ethics Training And Its Effect On The Diffusion Of Ethics In A Financial Organization, Justin Luebker

Graduate Theses and Dissertations

Ethical scandals have continued to batter corporate America into the twenty-first century. Companies such as Enron and MCI WorldCom became household names overnight because of ethical issues that shuttered the organizations’ operations and stunned shareholders. Training has served as a primary mechanism for companies to impart ethical values in employees and leadership teams. However, despite the ongoing focus and resources dedicated to education and associate development in this area, historically there appears to be no diffusion of ethical standards within organizations. There is a lack of consensus in current research regarding the effectiveness of organizational ethics training and its ability …

Data Analytics For Sustainable Food And Agriculture Systems, Megan Lord Reavis

Graduate Theses and Dissertations

The increasing concentration of anthropogenic greenhouse gases in the atmosphere is altering the climate, posing a serious threat to global agriculture and food security. Agriculture and food production contribute a quarter of all GHG emissions produced, so there is a critical need to limit emissions in this area while increasing food production to feed the anticipated 10 billion people by 2050. To address the needs of the future, data-driven solutions are needed to guide decision-making and provide support for actionable climate mitigation and survival strategies. Research efforts must be focused on analyzing problems on multiple scales, identifying new ways to …

Multifunctional Programmable Self-Assembled Nanoparticles In Nanomedicine, Yoshie Sakamaki

Graduate Theses and Dissertations

Developing methodologies to control the architecture of nanoparticles (NPs) at the atomic level prevents their inhomogeneity and leads to a variety of expected functions. Rationally designed nanoparticles can either be programmed or crystallized structures into pre-determined structures achieving tunable particle pore size and physiochemistry. In this dissertation, two broad classes of multifunctional nanoparticles are developed, metal-organic frameworks and DNA-NP aggregates.

Metal-organic frameworks are a novel class of highly porous crystalline materials built from organic linkers and metal cluster-based secondary building units. However, applications in bioremediation have not been developed very well especially in applications regarding drug delivery systems (DDS). The …