Digital Commons Network^™

Pathogenicity Of Staphylococcus Agnetis Associated With Lame Broilers With Osteomyelitis, Sura Faris Salih Zaki

Graduate Theses and Dissertations

We developed High Resolution Melt Analysis (HERMA) as a rapid and reliable molecular diagnostic assay for the detection and identification of the main bacterial species recovered from the blood and lesions of bacterial chondronecrosis with osteomyelitis (BCO) from the lame broilers at the University of Arkansas poultry research farm. Also, the present study confirms that raising young birds on suspended wire flooring has been proved to successfully induce lameness attributable to BCO with birds being more susceptible to bacteraemia than those that were raised on litter flooring. The newly described pathogen, Staphylococcus agnetis, has been reported to be overrepresented in …

Understanding Gender Gaps In Student Achievement And Stem Majors: The Role Of Student Effort, Test Structure, Self-Perceived Ability, And Parental Occupation, Lina Anaya Beltran

Graduate Theses and Dissertations

Increasing women’s participation in Science, Technology, Engineering, and Mathematics (STEM) has become a policy goal for many countries. This dissertation focuses on the origin and measurement of gender gaps in student achievement and self-perceived ability, as well as their potential role in predicting college career choices in STEM.

The first two chapters provide an international overview of gender achievement gaps and focus on issues around measurement using data from the Programme for International Student Assessment (PISA). These chapters study the role of student effort in predicting gender gaps in achievement and whether or not test structure, defined as question difficulty …

Development Of Biomaterials For Drug Delivery, Raquel De Castro

Graduate Theses and Dissertations

Drug delivery systems (DDS) have highly evolved in the last decades with the development of hydrogels and nanoparticles. However, high systemic uptake, side effects, low bioavailability, and encapsulation efficiency continue to be a major hurdle faced by such DDSs.

Nanoparticles and hydrogels can be specifically designed for targeted DDSs to mitigate some of the problems. This dissertation aimed to design two DDSs for ocular drug delivery and one for cancer treatment. The first project sought to develop chitosan nanoparticles (Cs-NP) using PEGDA as a copolymer to encapsulate gentamicin (GtS) for ocular drug delivery. Cs-NPs contain positive charges that can interact …

Economic Feasibility Of Sub-Surfaced Poultry Litter, James Timothy Stults

Graduate Theses and Dissertations

Livestock producers routinely spread fertilizer or broadcast poultry litter to improve forage production. With poultry litter widely available across the Southeastern United States and a cheaper source of plant nutrition than fertilizer when proximal to application sites, the novel application of litter below the soil surface, while costly, allows for greater nutrient retention than broadcasting. Since quantifying costs and benefits of sub-surface litter application (SSLA) is complex, we develop and present a spreadsheet tool for automated comparison between SSLA, fertilizer, and broadcasted litter for user-specific scenarios involving equipment choices (new, used, custom), desired nutrient needs for crops grown, litter nutrient …

Biochemical Characterization Of Small Molecule Inhibitor Binding On A Ras Related Gtpase And Its Effector Interactions, Djamali Muhoza

Graduate Theses and Dissertations

The Ras superfamily of GTPases has 167 proteins that are involved in various cellular processes such as proliferation, transformation, migration, and inhibition of cell death. Mutations, abnormal expression, and function of these proteins are observed in many diseases, including several forms of cancer. Even though these GTPases were among the first discovered oncogenes, no successful Ras drug candidate has successfully passed clinical trials. Drugs targeting these proteins have failed mainly because of the complexity of their regulation, their high affinity to GTP, and their structure’s dynamic nature. Recently, novel promising targeting approaches have renewed interest in the Ras drug discovery …

Examining The Demographic And Situational Characteristics That Predict News-Media Coverage Of Bias Homicides:, Caitlin Tidwell

Graduate Theses and Dissertations

Recent trends indicate that incidents of hate crime have become increasingly more violent since 2017, resulting in an overall increase in incidents of bias homicide specifically. Knowledge of bias crime among the general public largely derives from news media sources and, unfortunately, research that illustrates how the media covers and/or portrays bias crime incidents remains underdeveloped. Using theories of strategic news making, the current study examines the types of bias homicide incidents that receive media coverage by constructing a unique database of newspaper articles from prominent, national papers for 216 bias homicides that occurred between 2000 and 2019 drawn from …

Study Of Static And Dynamical Properties Of Complex Antiferroelectrics Materials, Kinnary Yogeshbhai Patel

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of the static and dynamical properties of the complex antiferroelectric materials using Effective Hamiltonian method and First principles calculations. In chapter 3, a novel elemental interatomic coupling in perovskite materials which bilinearly couples the antiferroelectric displacements of cations with the rotations of the oxygen octahedra. This new coupling explains a very complex crystal structure of prototypical antiferroelectric PbZrO3. My explanation provides a unified description of many other complex antipolar crystal structures in variety of perovskite materials, including the occurrence of incommensurate phases in some of them. In chapter 4, results and analysis …

Network-Based Detection And Prevention System Against Dns-Based Attacks, Yasir Faraj Mohammed

Graduate Theses and Dissertations

Individuals and organizations rely on the Internet as an essential environment for personal or business transactions. However, individuals and organizations have been primary targets for attacks that steal sensitive data. Adversaries can use different approaches to hide their activities inside the compromised network and communicate covertly between the malicious servers and the victims. The domain name system (DNS) protocol is one of these approaches that adversaries use to transfer stolen data outside the organization's network using various forms of DNS tunneling attacks. The main reason for targeting the DNS protocol is because DNS is available in almost every network, ignored, …

An 8-Bit Analog-To-Digital Converter For Battery Operated Wireless Sensor Nodes, Marvin Wayne Suggs Jr.

Graduate Theses and Dissertations

Wireless sensing networks (WSNs) collect analog information transduced into the form of a voltage or current. This data is typically converted into a digital representation of the value and transmitted wirelessly using various modulation techniques. As the available power and size is limited for wireless sensor nodes in many applications, a medium resolution Analog-to-Digital Converter (ADC) is proposed to convert a sensed voltage with moderate speeds to lower power consumption. Specifications also include a rail-to-rail input range and minimized errors associated with offset, gain, differential nonlinearity, and integral nonlinearity. To achieve these specifications, an 8-bit successive approximation register ADC is …

Artistry In Air: The Story Of The Younkins, Beth Lewis

Graduate Theses and Dissertations

For sixty years, a Northwest Arkansas family has dominated the world of general aviation by drawing upon its wealth of expertise, innovation and exceptional talent. Jim Younkin, an electrical engineer, invented an autopilot series that revolutionized the industry. His son, Bobby became one of the top aerobatic pilots in the world and Jim’s grandchildren, Matt and Amanda, also became critically acclaimed performers in the air show business. Like his father, Matt is ranked among the best of pilots in the industry. Jim also received national recognition for his stunning recreations of and restorations of historical aircraft. Bobby operated Younkin Airshows, …

Analysis Of Photodetector Based On Zinc Oxide And Cesium Lead Bromide Heterostructure With Interdigital Metallization, Tanveer Ahmed Siddique

Graduate Theses and Dissertations

In this thesis, photodetector based on the zinc oxide and cesium lead bromide hetero structure were fabricated and characterized. Zinc oxide (ZnO) nanoparticles were synthesized using solution processing and cesium lead bromide (CsPbBr3) thin film was synthesized using two step deposition method. Three phonon modes were obtained by the Raman spectroscopy of ZnO nanoparticles. X-ray diffraction spectra of ZnO exhibits five exciton peaks which denotes that the synthesized ZnO structure was of good crystallinity with wurtzite hexagonal phase. The absorbance spectrum of ZnO shows the bandgap (Eg) in the order of 3.5 eV that aligns with reported results. The photoluminescence …

The Effectiveness Of The Inquiry Based Learning Method In A Private Independent School Environment, Fred R. Eaves

Graduate Theses and Dissertations

The purpose of this study was to examine the effectiveness of an inquiry-based learning model (IBLM) in a small, independent school educational environment. Seisan Academy (SA) implemented a new teaching philosophy that centered around an inquiry-based learning approach with a focus on developing a more student-centered culture at the school. This new program was implemented with little feedback or measurement regarding the effectiveness of the approach. This study also looked to address the lack of formal evaluation regarding the implementation of the IBLM.

Multiple sampling strategies were implemented due to the mixed-methods nature of this study. Quantitative data collection included …

The Jordanian Novel In Postmodern Context, Hamed Alalamat

Graduate Theses and Dissertations

As the Jordanian culture is gradually impacted by the globalization process of late capitalism, this study argues that many Jordanian novels exhibit a number of postmodern characteristics, such as blurring boundaries and disrupting hierarchies, the use of pastiche as a compositional technique, formal fragmentation, and the weakness of utopian imagination. Adopting Fredric Jameson’s theory of postmodernism as a framework, the study explores ten Jordanian novels written between 1986 and 2016 to demonstrate that the modernization process and the cultural changes in the Arab world, in general, and in the Jordanian society, in particular, have increased the density of postmodern features …

Prediction, Recommendation And Group Analytics Models In The Domain Of Mashup Services And Cyber-Argumentation Platform, Md Mahfuzer Rahman

Graduate Theses and Dissertations

Mashup application development is becoming a widespread software development practice due to its appeal for a shorter application development period. Application developers usually use web APIs from different sources to create a new streamlined service and provide various features to end-users. This kind of practice saves time, ensures reliability, accuracy, and security in the developed applications. Mashup application developers integrate these available APIs into their applications. Still, they have to go through thousands of available web APIs and chose only a few appropriate ones for their application. Recommending relevant web APIs might help application developers in this situation. However, very …

Community And Idolatry: San Francisco Cajonos, Yalalag, And Betaza Through The Criminal Court Of Villa Alta, 1700-1704, Jessica Mitchell

Graduate Theses and Dissertations

The trials of San Francisco Cajonos and Betaza and Yalálag heard in Villa Alta’s criminal court depict many important facets of life in Colonial Oaxaca, and they especially paint the picture of community, how it was defined and how it operated in reality. Looking specifically at these two rich examples in Villa Alta’s criminal court, at the time, idolatry – native religion, rituals, and devotions defined by Catholics as idolatrous -- helped shape the lines of community and defined who belonged in which space. It also highlights how betrayal and revenge were construed by a community and the response for …

Developing A Microdialysis Sampling-Based Biofilm/Macrophage Co-Culture Model, Alda Diaz Perez

Graduate Theses and Dissertations

The host immune system and bacterial cells are known to interact during the human lifetime. Bacteria secrete a wide variety of signaling molecules, known as quorum sensing (QSC) molecules, that modulate the host immune system. While immune-biofilm interactions involve this chemical signaling network, the mechanisms through which this occurs are not well understood. This work aimed to develop a new method that can be used not only in vitro settings but also in vivo. The microdialysis sampling technique has widely been used in in vitro and in vivo settings in humans, mice, and rats for the collection of neuropeptides, cytokines, …

Replication And Tribological Engineering Of Physical Surfaces Using Two-Photon Lithography, Shelby Robert Maddox

Graduate Theses and Dissertations

Up to one-fifth of all energy consumed each year goes directly to overcoming frictional effects. This waste will remain even if renewable energy becomes feasible as a large-scale replacement for conventional fuel sources. If that wasted energy could be saved instead, then overall energy consumption could either decrease or be redirected to where it would be most beneficial to human and environmental flourishing. To this end, there is a need for strategies and techniques to reduce frictional energy loss. It is well established that surface texturing can be used to reduce friction. There are many industrial methods in current use …

Spatial Assessment Of Urban Growth In Cities Of The Decapolis; And The Implications For Modern Cities, Wade A. Pierson

Graduate Theses and Dissertations

The Levant’s Decapolis was a network of ten cities in Greco-Roman Israel, Jordan, and Syria that established a thriving economic community. The Decapolis was home to ancient and modern cities like Damascus (Dammásq) and Amman (Philadelphia). Despite the various origins of these cities, Roman administration and their city planners oversaw the implementation of idealized Roman city form throughout the region. Three Decapolis cities represent intriguing examples of the larger confederation. Philadelphia (Amman), Gerasa (Jerash), and Gadara (Umm Qais) represent cities of common original urban form which developed drastically diverse urban morphologies over time.

Spatial analyses of these cities required working …

Optimization Of Broken Rice Consumption Through Understanding The Confluence Of Sensory And Economic Preferences, Matthew Greer Richardson

Graduate Theses and Dissertations

The authors were perplexed by the seeming dichotomy between the majority 70% of Haitian consumers being chronically food insecure, but still preferring to pay premium international market prices for long-grain rice that constitutes 30% of the calories in this poorest nation in the Western Hemisphere. The aim of this study was to determine the optimal percent broken rice in regards to price specifically to Haiti. Optimization between quality and price point is seen as the best rice for the price, and can be found through combining individual preferences with willingness to pay. Broken rice (brokens) garner a significantly discounted price …

Starter Nitrogen Source And Preflood Nitrogen Rate Effects On Rice Grown On Clay Soils, Linda Rachelle Martin

Graduate Theses and Dissertations

Seedling rice (Oryza sativa L.) grown on clayey-textured soils generally develops slowly as compared to loamy-textured soils. Our research examined the effects of starter-N source and preflood-N rates on canopy closure, total aboveground N uptake, and grain yield of rice grown on clayey-textured soils. Eleven field trials were established in Arkansas and Mississippi including five trials with a hybrid cultivar and six trials using a pure-line cultivar. Starter-N sources included no starter-N (NONE), ammonium sulfate (AMS), diammonium phosphate (DAP), and urea (UREA) applied at 24 kg N ha-1 at the rice 2-leaf stage and five preflood-N rates ranging from 0-224 …

Characteristic Reassignment For Hardware Trojan Detection, Noah Waller

Graduate Theses and Dissertations

With the current business model and increasing complexity of hardware designs, third-party Intellectual Properties (IPs) are prevalently incorporated into first-party designs. However, the use of third-party IPs increases security concerns related to hardware Trojans inserted by attackers. A core threat posed by Hardware Trojans is the difficulty in detecting such malicious insertions/alternations in order to prevent the damage. This thesis work provides major improvements on a soft IP analysis methodology and tool known as the Structural Checking tool, which analyzes Register-Transfer Level (RTL) soft IPs for determining their functionalities and screening for hardware Trojans. This is done by breaking down …

Memory Module Design For High-Temperature Applications In Sic Cmos Technology, Affan Abbasi

Graduate Theses and Dissertations

The wide bandgap (WBG) characteristics of SiC play a significant and disruptive role in the power electronics industry. The same characteristics make this material a viable choice for high-temperature electronics systems. Leveraging the high-temperature capability of SiC is crucial to automotive, space exploration, aerospace, deep well drilling, and gas turbines. A significant issue with the high-temperature operation is the exponential increase in leakage current. The lower intrinsic carrier concentration of SiC (10-9 cm-3) compared to Si (1010 cm-3) leads to lower leakage over temperature. Several researchers have demonstrated analog and digital circuits designed in SiC. However, a memory module is …

Non-Volatile Memory Adaptation In Asynchronous Microcontroller For Low Leakage Power And Fast Turn-On Time, Jean Pierre Thierry Habimana

Graduate Theses and Dissertations

This dissertation presents an MSP430 microcontroller implementation using Multi-Threshold NULL Convention Logic (MTNCL) methodology combined with an asynchronous non-volatile magnetic random-access-memory (RAM) to achieve low leakage power and fast turn-on. This asynchronous non-volatile RAM is designed with a Spin-Transfer Torque (STT) memory device model and CMOS transistors in a 65 nm technology. A self-timed Quasi-Delay-Insensitive 1 KB STT RAM is designed with an MTNCL interface and handshaking protocol. A replica methodology is implemented to handle write operation completion detection for long state-switching delays of the STT memory device. The MTNCL MSP430 core is integrated with the STT RAM to create …

Influence Of Local- And Landscape-Scale Factors On Avian Assemblage In Fragmented Tallgrass Prairie Landscape, Pooja Panwar

Graduate Theses and Dissertations

Agricultural expansion and increasing urbanization are driving rapid landscape modification in the Tallgrass prairies ecosystem and are affecting biodiversity at multiple spatial scales. Thus, the conservation of fragmented grassland and steeply declining grassland avifauna is dependent on the relationship between local- and landscape-scale factors and avian assemblage. We also need to understand how these factors, operating at different spatial scales, drive the occupancy of different guilds in the assemblage. We conducted repeated point count surveys during the breeding season of 2019 at 66 grassland sites across Arkansas and Missouri, USA. We developed a multi-species occupancy model to estimate species richness, …

When It Rains, It Pours: A Case Study Of Spatio-Temporal Variations In High-Intensity Precipitation Events In Arkansas, Deanna Mantooth-Hendrix

Graduate Theses and Dissertations

Climate change is having an impact on weather systems and ecosystems worldwide. Glaciers are receding, oceans are acidifying, hurricanes are stronger, and extreme precipitation is increasing in frequency. Even with the wealth of data and knowledge about the threat of climate change, some places are slow to adapt because they think that the impact to their ecosystem will not be severe. The goal of this project was to determine if climate change is having an impact on extreme precipitation in the top urban areas of Arkansas. The major concern with an increase in extreme events in urban areas is flooding. …

Characterization Of Protein Aggregation Using A Solid-State Nanopore Device, Mitu Chandra Acharjee

Graduate Theses and Dissertations

Protein aggregation has been linked to many chronic and devastating neurodegenerative human diseases and is also strongly associated with aging. In the case of neurodegenerative diseases, α, β tubulins and tau proteins dissociate in a neuron cell and aggregate both intra and extra-cellularly. Tau and tubulin aggregations were found as one of the major causes of many neurodegenerative diseases, such as Parkinson’s, Picks, Alzheimer’s, Huntington, and Prion. Finding the state and mechanism of protein aggregation is significant. In this work, tau and tubulin aggregations were detected in ionic solutions using the solid-state nanopore technique. Besides tau and tubulin, aggregations of …

I Matter: Understanding The Self-Care Practices Of School Counselors During The Covid-19 Pandemic And How Internal And External Factors Create Barriers, Alisha Rene Marie Jones

Graduate Theses and Dissertations

Diminished self-care practices and heightened stress of school counselors is a continuing problem in education. With role ambiguity, high student-to-counselor ratios, emotional exhaustion, and others adding pressure to the roles and responsibilities of school counselors, this study investigated the self-care practices of Missouri school counselors and the internal and external factors which influence them, specifically within the context COVID-19. Clayton Alderfer’s (1972) Existence, Relatedness, and Growth theory was used as a theoretical framework for chosen self-care practices represented in this study and was supported by Robert Kegan’s and Lisa Lahey’s (2009) Immunity to Change theory to understand the competing commitments …

Low-Power And Reconfigurable Asynchronous Asic Design Implementing Recurrent Neural Networks, Spencer Nelson

Graduate Theses and Dissertations

Artificial intelligence (AI) has experienced a tremendous surge in recent years, resulting in high demand for a wide array of implementations of algorithms in the field. With the rise of Internet-of-Things devices, the need for artificial intelligence algorithms implemented in hardware with tight design restrictions has become even more prevalent. In terms of low power and area, ASIC implementations have the best case. However, these implementations suffer from high non-recurring engineering costs, long time-to-market, and a complete lack of flexibility, which significantly hurts their appeal in an environment where time-to-market is so critical. The time-to-market gap can be shortened through …

Factors Influencing Stakeholder Support Of A Bond Referendum In A Rural Kansas School District, Joshua M. Woodward

Graduate Theses and Dissertations

The purpose of this study is to examine factors that influence stakeholder support of bond elections targeted for capital improvements in a rural school district in Kansas. The study uses existing research to identify factors that influence school bond referendum success. To better understand the factors identified in the research literature that influence stakeholder support in the focus district, data were gathered from stakeholders within the school district of focus through a perceptual survey and focus group interviews.

The availability of research on school bond referendum success and failure is plentiful. However, specific research on factors that influence rural school …

Securing Fog Federation From Behavior Of Rogue Nodes, Mohammed Saleh H. Alshehri

Graduate Theses and Dissertations

As the technological revolution advanced information security evolved with an increased need for confidential data protection on the internet. Individuals and organizations typically prefer outsourcing their confidential data to the cloud for processing and storage. As promising as the cloud computing paradigm is, it creates challenges; everything from data security to time latency issues with data computation and delivery to end-users. In response to these challenges CISCO introduced the fog computing paradigm in 2012. The intent was to overcome issues such as time latency and communication overhead and to bring computing and storage resources close to the ground and the …