Digital Commons Network^™

A Holy Tug Of War: Us Christians Against The Contras (1970-1990), Mark Maxwell Brown

Theses and Dissertations--History

After the Sandinista revolution of 1979 ousted the longstanding Somoza dynasty of Nicaragua, the small Central American nation became an obsession of US foreign policy as the Reagan administration committed its efforts to deposing the leftist revolutionary government through the funding and training of the Contras, a counter-revolutionary guerrilla group. With the Cold War at a boiling point, continued control and influence over Central America became a pillar of US anticommunist agenda. Uniquely, many of the most ardent critics of the Reagan administration during this period of violent intervention were Christian missionaries. The Sandinistas were able to defeat the Somoza …

Making Sense Of The Divinely Beautiful: Essays On Friendship, Love, And Attraction, Michelle Catlin

Theses and Dissertations--Philosophy

Essay 1: As interpersonal communication has changed with the proliferation of technology-based forms of meeting and interacting with others, philosophers have begun considering ways in which these new types of communication have altered the landscape of our relationships. Although philosophers are split on whether online friendships can measure up to the Aristotelean standard of virtue friendship, none have questioned the importance of truth telling or accurate representation of oneself in the context of online sharing. The underlying assumption is that in a virtuous friendship, there is no role whatsoever for anything other than strict honestly. I disagree with this …

Stress, Burnout, And Well-Being In New Veterinary Graduates: Evaluating A Pilot Online Professional Development Program, Addie Rose Reinhard

Theses and Dissertations--Community & Leadership Development

Suicide, stress, and burnout are occurring at high rates among veterinary professionals, and the transition from student to practicing veterinarian has been shown to be a particularly stressful time. The aim of this study was to evaluate an online professional development program for new veterinary graduates incorporating peer social support and training in professional skills important for success in the transition to practice. In this mixed methods study, the program was evaluated qualitatively with focus group data and quantitatively by assessing knowledge gained and levels of stress, burnout, social support, and well-being. Seven new veterinary graduates participated in the program, …

Living As An Impostor: An Exploration Of The Lived Experiences Among Multiracial Youth In Secondary Agricultural Education, Juliana Danielle Markham

Theses and Dissertations--Community & Leadership Development

The racial demographic of the United States is ever changing, and the increase of multiracial children is substantial. This multiple-case study examined the lived experiences of multiracial youth in secondary agricultural education. This study finds evidence of Impostor Phenomenon among these multiracial students in regard to their races. This study provides insight to advise other educational institutions and organizations on how these multiracial students perceive and are perceived, within agricultural education, how it affects them, and gives recommendations to improve the future experiences of multiracial students within agricultural education.

The Role Of Vascular Endothelial Growth Factor In Leukemia Trafficking, Shaw Powell

Theses and Dissertations--Medical Sciences

Vascular endothelial growth factor (VEGF) is a signaling protein involved in inducing and regulating endothelial cell proliferation and function (Duffy et al 2000). VEGF is also involved in cancer progression, as it induces vascular permeability and promotes angiogenesis to tumor laden areas, giving cancer cells critical oxygen and nutrients (Hoeppner et al.,2012. Studies indicate VEGF prevents lymphoblast apoptosis, which may contribute to leukemia formation and enable the proliferation of leukemic cells (Duffy et al 2000). Ongoing research seeks to further examine VEGF in leukemia, using a rag2:GFP-Myc expressing transgenic zebrafish as the animal model of T-cell Acute Lymphoblastic Leukemia (T-ALL). …

S. Gordonii-Produced Hydrogen Peroxide Modulates Mir-663a And Ccl20 Expression In Oral Epithelial Cells, Marshall Houston Maynard

Theses and Dissertations--Medical Sciences

The mechanisms through which a persistent recognition of commensal bacteria by oral epithelial cells (OECs) mitigates an uncontrolled inflammatory response of the oral mucosa remain unknown. CCL20 secretion by OECs in response to pathogenic bacteria is regulated by S. gordonii (Sg)-induced miR-663a; nevertheless, the mechanisms involved in these Sg-modulated responses remain to be elucidated. Since Sg is a hydrogen peroxide (H₂O₂) producer, and H₂O₂ has been shown to stimulate miRNA expression, we hypothesized that H₂O₂ could be involved in Sg-induced miR663a and CCL20 responses. Expression of miR663a …

Application Of Genetic Techniques To Investigate Chlamydia Trachomatis Type Iii Secretion Effector Biology, Gabrielle Keb

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Chlamydia trachomatis is the causative agent of the most reported bacterial sexually transmitted disease in the United States. The establishment of an intracellular niche within mucosal epithelium is sufficient to drive immunopathology and disease sequela. As obligate intracellular bacteria, Chlamydia spp. have evolved numerous mechanisms for establishing an intracellular growth environment. The type III secretion system (T3SS) delivers effector proteins to the host cytosol and is essential for C. trachomatis invasion and development. The effectors TmeA, TmeB, and TarP, are all secreted during C. trachomatis invasion. TarP and TmeA have been associated with manipulation of actin networks and are …

What You Do Or What You Say? An Examination Of Analyst Reactions To Prototypical And Non-Prototypical Ceos Linguistic And Competitive Behaviors, Courtney Hart

Theses and Dissertations--Management

Non-prototypical CEOs are those that process different demographic characteristics from a target reference group. In the US, a non-prototypical CEO is both white and male. While the negative responses to non-prototypical leaders based on race and gender have been well documented, we know less on what these leaders do that may influence biased evaluations. In this dissertation I took an impression management view to examine analysts’ evaluative bias (AEB) on prototypical and non-prototypical CEOs hiding linguistic behaviors and competitive aggressiveness. Specifically, I examined hiding linguistic behaviors on quarterly conference calls and two attributes of competitive repertoire will be researched. Drawing …

Pharmacist Provision Of Contraception Services In Kentucky: Opinions And Policy Interventions, Dustin K. Miracle

Theses and Dissertations--Pharmacy

Unintended pregnancy continues to be a prevalent issue across the United States, impacting millions of women annually. While several states have enacted policies expanding pharmacist services to allow for provision of hormonal contraception, Kentucky has yet to do so. Likewise, although provision of nonprescription hormonal contraception could be authorized under Kentucky regulation, prior to this study, this had yet to be done. The objectives of this study were to 1) understand the opinions of Kentucky pharmacists and student pharmacists regarding provision of hormonal contraception services through a board-authorized protocol, 2) understand the opinions of Kentucky pharmacists and student pharmacists regarding …

Understanding Absorption, Supersaturation, And Drug Activity In Solution: Working Towards Developing A More Biorelevant Media, Freddy Arce

Theses and Dissertations--Pharmacy

With the looming dominance of poorly water-soluble chemical entities within the pharmaceutical pipeline, the pharmaceutical industry has leaned on the use of supersaturating drug delivery systems (SDDSs) to achieve efficacious concentrations within the gastrointestinal fluids. SDDSs aim to achieve concentrations in solutions greater than the solubility of the lowest energy crystalline form. However, the generation of supersaturated solutions of active pharmaceutical ingredients (APIs) creates a strong crystallization potential, which is undesirable.

In product development, supersaturating products often fail in Phase I and Phase II clinical trials due to poor oral bioavailability and a lack of in vivo efficacy. Pre-clinical testing …

Multiple Proteinopathies And Their Role In Cognitive Impairment And Neurodegenerative Diseases, Shama D. Karanth

Theses and Dissertations--Epidemiology and Biostatistics

Most age-related neurodegenerative disorders are associated with the aggregation of misfolded and aberrant proteins. Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders and is highly prevalent in older adults. Neuropathologically, AD is characterized by the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles (NFTs). Other misfolded proteins, including α-synuclein and transactive response DNA-binding protein 43 (TDP-43), are also commonly observed in aged brains. Aberrant α-synuclein has been associated with Parkinson's disease, Dementia with Lewy bodies, and multiple system atrophy, whereas TDP-43 has been associated with multiple neurological diseases, the most common of which was designated as limbic-predominant, …

Enhancing Drug Overdose Mortality Surveillance Through Natural Language Processing And Machine Learning, Patrick J. Ward

Theses and Dissertations--Epidemiology and Biostatistics

Epidemiological surveillance is key to monitoring and assessing the health of populations. Drug overdose surveillance has become an increasingly important part of public health practice as overdose morbidity and mortality has increased due in large part to the opioid crisis. Monitoring drug overdose mortality relies on death certificate data, which has several limitations including timeliness and the coding structure used to identify specific substances that caused death. These limitations stem from the need to analyze the free-text cause-of-death sections of the death certificate that are completed by the medical certifier during death investigation. Other fields, including clinical sciences, have utilized …

The Role Of Adverse Childhood Experiences (Aces) In The Military And Predicting Current Distress, Douglas A. Foote

Theses and Dissertations--Social Work

The United States has been in continuous military conflicts for the past two decades. The importance of having a fully capable fighting force is unquestionable, but too often, military units are not at full capacity due to service members (SMs) within a unit being unable to deploy due to mental health impediments. The surge of non-deployable SMs is a national security concern as it affects the SMs’ quality of life and Department of Defense’s (DoD) ability to fight today’s conflicts.

This study bolsters military ACE research because it sampled more female and officer participants compared to extant military ACE studies. …

Development Of An Autonomous Navigation System For The Shuttle Car In Underground Room & Pillar Coal Mines, Vasileios Androulakis

Theses and Dissertations--Mining Engineering

In recent years, autonomous solutions in the multi-disciplinary field of the mining engineering have been an extremely popular applied research topic. The growing demand for mineral supplies combined with the steady decline in the available surface reserves has driven the mining industry to mine deeper underground deposits. These deposits are difficult to access, and the environment may be hazardous to mine personnel (e.g., increased heat, difficult ventilation conditions, etc.). Moreover, current mining methods expose the miners to numerous occupational hazards such as working in the proximity of heavy mining equipment, possible roof falls, as well as noise and dust. As …

Capture Of Respirable Dust Using Maintenance Free Impingement Screen, Neeraj Kumar Gupta

Theses and Dissertations--Mining Engineering

Dust produced during mining activities has a detrimental effect on both miners’ health and operations’ safety. There is no definitive treatment for coal miners’ pneumoconiosis (CWP), which is caused by prolonged inhalation of respirable dust. Elevated coal dust concentrations have also been shown to cause several disastrous explosions in the United States and worldwide, resulting in the death of miners and loss of operations. Flooded-bed dust scrubbers are used on all modern-day continuous miners. These devices cleanse the dust-laden air and assist in bringing fresh air towards the mining face. Scrubbers use a multi-layered fibrous screen to capture airborne particles. …

The Role Of Live Conifer Fuels In Crown Fires Spread, Adnan Darwish Ahmad

Theses and Dissertations--Mechanical and Aerospace Engineering

Live foliage for some tree and shrub species can support flaming fire spread at much higher moisture content than dead fuel materials. However, the role of live fuels in forest fires has been controversial in the past decades. Although ignition and spread statistical data for live and dead fuels exist in the literature, a clear understanding of the fundamental difference in the burning behavior is missing. To illuminate the role of live fuel on forest fire spreading, a laboratory ignition experiment was designed to examine the burning behavior of live Norway spruce needles. A schlieren-Infrared combined measurement apparatus was developed …

Use Of Microscale Hydrophobic Surface Features For Integration Of 3d Cell Culture Into Multi-Functional Microfluidic Devices, Soroosh Torabi

Theses and Dissertations--Mechanical and Aerospace Engineering

3D cell culture and microfluidics both represent powerful tools for replicating critical components of the cell microenvironment; however, challenges involved in integration of the two and compatibility with standard tissue culture protocols still represent a steep barrier to widespread adoption. Here we demonstrate the use of engineered surface roughness in the form of microfluidic channels to integrate 3D cell-laden hydrogels and microfluidic fluid delivery. When a liquid hydrogel precursor solution is pipetted onto a surface containing open microfluidic channels, the solid/liquid/air interface becomes pinned at sharp edges such that the hydrogel forms the “fourth wall” of the channels upon solidification. …

Evaluation Of Radiative Conductivity Inside A Porous Media With The Effect Of Participating Medium Based On Microscale Imaging, Mingping Zheng

Theses and Dissertations--Mechanical and Aerospace Engineering

Space vehicles will experience high loads of heat while entering the planetary atmosphere. At such high temperature, radiation becomes the dominant mode of heat transfer. Since the atmospheric entry environment is nearly impossible to duplicate in a laboratory environment, a numerical model to evaluate thermal performance of the thermal protection system was established. The model simulates the radiative heat transfer process in highly porous media, and the process also takes into account the influence of the participating media. An iterative approach and periodic boundary conditions are used to solve The unbalanced heat flux problem. CT scanned microscale Fiberform and artificial …

Viscoelasticity Of Ptfe-Based Face Seals, Bo Tan

Theses and Dissertations--Mechanical and Aerospace Engineering

PTFE-based materials are widely used in areas of tribology, particularly in seal and bearing applications because of their outstanding self-lubricating properties. Often in dynamic seal applications there is a need for ultra-low mechanical friction loss between the sealing surfaces. Due to its extremely low friction coefficient, there is interest in employing Polytetrafluoroethylene (PTFE) materials in such applications. One challenging aspect of employing PTFE is that these materials are viscoelastic and plastic. This dissertation concentrates on the modeling of viscoelastic material response when used as mechanical face seals with a focus on PTFE-based materials. First, the viscoelastic characteristics are measured through …

Modeling Thin Layers In Material Response Solvers, Christen Setters

Theses and Dissertations--Mechanical and Aerospace Engineering

Thermal Protection Systems (TPS) are a necessary component for atmospheric entry. Most TPS contain thin layers of various materials such as ceramic coatings, pore sealers and bonding agents. When modeling TPS, these thin layers are often neglected due to the difference in scale between the TPS (centimeters) and the thin layers (micrometers). In this study, a volume-averaging flux-conservation method is implemented in the governing equations of a finite volume material response code. The model proposes the addition of a volume and area fraction coefficient which utilizes a weighted-averaging between the amount of thin layer and heat shield material in a …

Cell And Biofilm Adhesion Strength Quantified By The Laser Spallation Technique Yields A Novel Biocompatibility Metric, The Adhesion Index, James Boyd

Theses and Dissertations--Mechanical and Aerospace Engineering

Implant associated infections are one of the leading causes of hospital acquired infections in the United States. Medical orthopedic implant devices are designed to improve adhesion of relevant cells within our body. In the case of orthopedic implants, osteoblast cells will adhere and allow for proper integration with the body’s bones. However, virulent bacteria will also adhere onto medical implants and proliferate into biofilms. Bacterial biofilms become extremely difficult to eradicate clinically as antibiotics are not as effective, resulting in severe infections or loss of implant. The aim of this research is to quantify the adhesion strength differential between relevant …

Effective Modulus Of Cracked Bodies: A Finite Element Analysis, Alan Thomas Varughese

Theses and Dissertations--Mechanical and Aerospace Engineering

This thesis considers how cracks in an elastic body can alter the body’s elastic properties. In the present study the elastic property of note is the elastic or young’s modulus. It is desired to investigate to what extent the number and orientation of cracks can cause a reduction in the elastic modulus. Because of the complex nature of the elastic fields resulting from multiple cracks interacting together in a finite geometry an analytical solution is not possible or considered. Rather the Finite Element Method is used to determine the elastic response to a body with many cracks. This provides a …

A Computational Fluid-Structure Interaction Method For Simulating Supersonic Parachute Inflation, Jonathan Boustani

Theses and Dissertations--Mechanical and Aerospace Engineering

Following the successful landing of the Curiosity rover on the Martian surface in 2012, NASA/JPL conducted the low-density supersonic decelerator (LDSD) missions to develop large diameter parachutes to land the increasingly heavier payloads being sent to the Martian surface. Unexpectedly, both of the tested parachutes failed far below their design loads. It became clear that there was an inability to model and predict loads that occur during supersonic parachute inflation. In this dissertation, a new computational method that was developed to provide NASA with the capability to simulate supersonic parachute inflation is presented and validated. The method considers the loose …

Structural Optimization Of Space Transit Vehicle Concept, Hercules, James Philip Rogers

Theses and Dissertations--Mechanical and Aerospace Engineering

STRUCTURAL OPTIMIZATION OF SPACE TRANSIT VEHICLE CONCEPT, HERCULES:

A COMPARATIVE STUDY OF STRUCTURAL OPTIONS

Hercules is a vehicle concept developed by NASA Langley's Vehicle Analysis Branch to satisfy the need for sustainable transit between Earth, the moon, and Mars. Hercules features unprecedented abort capabilities and mission flexibility to aid in NASA's Mars campaign. By utilizing modern software to perform structural analysis and optimization for a large selection of stiffened panel concepts, beam concepts, and materials trends in the structural optimization emerge. These trends will be invaluable for the design of future spacecraft needed to fulfill similar roles.

The structural optimization …

Utilizing Patient-Derived Epithelial Ovarian Cancer Tumor Organoids To Predict Carboplatin Resistance, Justin W. Gorski

Theses and Dissertations--Clinical and Translational Science

The development of patient-derived tumor organoids (TOs) from epithelial ovarian cancer tumor obtained at the time of primary or interval debulking surgery has the potential to play an important role in precision medicine.

Here, we utilize TOs to test front-line chemotherapy sensitivity and to investigate genomic drivers of carboplatin resistance. We developed six high grade serous epithelial ovarian cancer tumor organoids from tissue obtained during debulking surgery (2 neoadjuvant carboplatin exposed, 4 chemo-naïve). Each organoid line was screened for sensitivity to carboplatin at four different doses (100, 10, 1 and 0.1µM). Cell viability curves and resultant EC50 values were determined …

Profiling Social Media Tourists Using Literature During 2015-2019: Criminal Profiling Method, Jijun Chen

Theses and Dissertations--Retailing and Tourism Management

With the continuous development of mobile commerce and the Internet, social media has deeply penetrated people’s lives and fundamentally changed the way of searching, reading and using travel-related information. With this backdrop, this research studied social media tourists (SMTs) who share or acquire information related to the hospitality and tourism on social media platforms. Based on 271 empirical articles retrieved from major databases and top hospitality and tourism journals in the recent five years from 2015 to 2019, this research developed a profiling framework about SMTs using criminal profiling method. The findings showed the possibility of using the criminal profiling …

The Roles Of The Actin Network And Co-Opted Host Factors In Tbsv Replication, Melissa Gabriela Molho Medina

Theses and Dissertations--Plant Pathology

Positive-stranded (+) RNA viruses are the largest family of viruses that infect plants, causing important economic losses in different crops. Tomato bushy stunt virus (TBSV), a small positive-stranded RNA virus, has emerged as a model virus to study virus-host interactions. TBSV encodes for only five proteins, therefore, to infect the host cell TBSV co-opts selected host components and subverts specific molecular pathways.

Firstly, I performed a proteomic screening using Arabidopsis proteins. I found that TBSV viral replication proteins interact with 88 host proteins, including the ubiquitin-conjugating enzyme 2 (Ubc2), fructose 1,6 biphosphate aldolase (Fba1), and several members of the Hps70 …

Seeing Double With Cannabis: Heteroploid Populations In Bipolaris Gigantea, Causal Agent Of Bipolaris Leaf Spot, Desiree Szarka

Theses and Dissertations--Plant Pathology

Bipolaris leaf spot (BLS) disease emerged with the reintroduction of hemp as a crop in the United States following more than 60 years of prohibition. The causal agent was identified as Bipolaris gigantea (=Drechslera gigantea), a known minor pathogen of monocots which causes devastating disease on hemp. BLS has been confirmed throughout Kentucky and reported in 15 states. Morphology and growth characteristics of isolates from eight counties across Kentucky were similar with the exception of some isolates producing protoperithecial-like structures. Phylogenetic and whole genome analysis indicated that some isolates were haploid, containing a single allele at each gene …

Characteristics Of Cercospora Nicotianae With Reduced Sensitvity To Azoxystrobin, William Barrett Barlow

Theses and Dissertations--Plant Pathology

Burley and dark tobacco production are important to agriculture in Kentucky, worth $145.1 and $94.4 million in 2020, respectively. The price received for a tobacco crop is influenced by leaf quality, determined by multiple characteristics including leaf damage. Frogeye leaf spot (FLS), caused by Cercospora nicotianae, has historically been a minor disease of tobacco. However, when FLS infections reach the upper canopy of tobacco, lesions are seen as damage that negatively influence leaf quality. Fungicides are regularly used to manage foliar diseases of tobacco, and the only systemic fungicide active ingredient labeled for tobacco is azoxystrobin. Azoxystrobin belongs to the …

An Assessment Of The Carrier State And A Novel Marker Of Leptospira And Abortion In Central Kentucky Horses, Gloria Louise Gellin

Theses and Dissertations--Veterinary Science

Leptospirosis is a reemerging zoonotic infection of worldwide importance and affects all mammals. The bacterium is transmitted to animals and humans by urine, fetal membranes and body fluids. Leptospira shedding in the urine contaminates both soil and water, exposing both humans and animals to the bacterium. Leptospirosis in horses can cause abortion and is one of the etiologies of equine recurrent uveitis which can lead to blindness. Equine leptospiral abortion in Central Kentucky is primarily caused by serovar Pomona, with occasional cases attributed to serovar Grippotyphosa. There are a few reports in the literature attributing abortion to serovar Bratislava in …