Digital Commons Network^™

The Smallest Solution Of An Isotropic Quadratic Form, Deborah H. Blevins

Theses and Dissertations--Mathematics

An isotropic quadratic form f(x₁,...,x_n) = ∑ ⁿ_i=1 ∑ ⁿ_j=1 f_ijx_ix_j defined on a Z- lattice has a smallest solution, where the size of the solution is measured using the infinity norm (∥ ∥_∞), the l₁ norm (∥ ∥₁), or the Euclidean norm (∥ ∥₂). Much work has been done to find the least upper bound and greatest lower bound on the smallest solution, beginning with Cassels in the mid-1950’s. Defining F := (f₁₁,...,f …

Solubility Of Additive Forms Over Local Fields, Drew Duncan

Theses and Dissertations--Mathematics

Michael Knapp, in a previous work, conjectured that every additive sextic form over $\mathbb{Q}_2(\sqrt{-1})$ and $\mathbb{Q}_2(\sqrt{-5})$ in seven variables has a nontrivial zero. In this dissertation, I show that this conjecture is true, establishing that $$\Gamma^*(6, \mathbb{Q}_2(\sqrt{-1})) = \Gamma^*(6, \mathbb{Q}_2(\sqrt{-5})) = 7.$$ I then determine the minimal number of variables $\Gamma^*(d, K)$ which guarantees a nontrivial solution for every additive form of degree $d=2m$, $m$ odd, $m \ge 3$ over the six ramified quadratic extensions of $\mathbb{Q}_2$. We prove that if $$K \in \{\mathbb{Q}_2(\sqrt{2}), \mathbb{Q}_2(\sqrt{10}), \mathbb{Q}_2(\sqrt{-2}), \mathbb{Q}_2(\sqrt{-10})\},$$ then $$\Gamma^*(d,K) = \frac{3}{2}d,$$ and if $$K \in \{\mathbb{Q}_2(\sqrt{-1}), \mathbb{Q}_2(\sqrt{-5})\},$$ then $$\Gamma^*(d,K) = …

Some Proofs Regarding Minami Estimates And Local Eigenvalue Statistics For Some Random Schrödinger Operator Models, Samuel Herschenfeld

Theses and Dissertations--Mathematics

We provide three proofs on different, but related models in the field of random Schrödinger operators. All three results are motivated by the desire to extend results and techniques on eigenvalue statistics or Minami estimates (an essential ingredient Poisson eigenvalue statistics).

Chapters 2 and 4 are explorations of the only two known techniques for proving Minami estimates for continuum Minami estimates. In Chapter 2, we provide an alternative and simplified proof of Klopp that holds in d = 1. Chapter 4 is an application of the techniques of Dietlein and Elgart to prove a Minami estimate for finite rank lattice …

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 …

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.

Acl Injury, A Time Course Study Of Transcriptional Changes, Thomas Carter

Theses and Dissertations--Medical Sciences

ACL tear is a common injury in the United States with a significant cost and time burden during recovery; reconstructive surgery often results in weakened quadricep muscle and higher risk of posttraumatic osteoarthritis. Prior research has highlighted cellular derangements within the quadriceps after ACL injury and reconstruction, but the early molecular effectors of cellular dysfunction remain to be identified. To further understand the molecular effectors of quadriceps dysfunction following ACL injury, this study aims to quantify the timing and magnitude of transcriptional differences between the quadriceps muscle of injured and contralateral non-injured limbs. These data will provide insight into the …

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 …

Three Essays In Regional Taxation, Kenneth Tester

Theses and Dissertations--Economics

This dissertation looks at the role that geographically limited taxation and the behavioral response of economic agents to different forms of regional taxation. While geographic taxation is typically thought to be confined to state and local taxes, federal tax policy can also create designated areas that receive preferential tax treatment. In this dissertation, both types of regional taxation are examined and are unified under common themes such as tax mobility and the definition of the tax base.

In chapter 2, I examine the important effect of how the location of high income earners employment is influenced by taxes in the …

Dimension Reduction Techniques In Regression, Pei Wang

Theses and Dissertations--Statistics

Because of the advances of modern technology, the size of the collected data nowadays is larger and the structure is more complex. To deal with such kinds of data, sufficient dimension reduction (SDR) and reduced rank (RR) regression are two powerful tools. This dissertation focuses on these two tools and it is composed of three projects. In the first project, we introduce a new SDR method through a novel approach of feature filter to recover the central mean subspace exhaustively along with a method to determine the dimension, two variable selection methods, and extensions to multivariate response and large p …

Novel Nonparametric Testing Approaches For Multivariate Growth Curve Data: Finite-Sample, Resampling And Rank-Based Methods, Ting Zeng

Theses and Dissertations--Statistics

Multivariate growth curve data naturally arise in various fields, for example, biomedical science, public health, agriculture, social science and so on. For data of this type, the classical approach is to conduct multivariate analysis of variance (MANOVA) based on Wilks' Lambda and other multivariate statistics, which require the assumptions of multivariate normality and homogeneity of within-cell covariance matrices. However, data being analyzed nowadays show marked departure from multivariate normal distribution and homoscedasticity. In this dissertation, we investigate nonparametric testing approaches for multivariate growth curve data from three aspects, i.e., finite-sample, resampling and rank-based methods.

The first project proposes an approximate …

Estimating And Testing Treatment Effects With Misclassified Multivariate Data, Zi Ye

Theses and Dissertations--Statistics

Clinical trials are often used to assess drug efficacy and safety. Participants are sometimes pre-stratified into different groups by diagnostic tools. However, these diagnostic tools are fallible. The traditional method ignores this problem and assumes the diagnostic devices are perfect. This assumption will lead to inefficient and biased estimators. In this era of personalized medicine and measurement-based care, the issues of bias and efficiency are of paramount importance. Despite the prominence, only few researches evaluated the treatment effect in the presence of misclassifications in some special cases and most others focus on assessing the accuracy of the diagnostic devices. In …

Interactions Of Post-Pks Enzymes Of The Mithramycin Biosynthetic Pathway, Ryan Wheeler

Theses and Dissertations--Pharmacy

Combinatorial biosynthesis is a powerful tool for generating new, more active drug analogues to combat disease. But in order for combinatorial biosynthesis to be employed to its full potential, a deep understanding of the enzymes that produce the parent molecule must be had. The goals of the work presented in this thesis are to characterize the reaction catalyzed by MtmW, the final enzyme in the mithramycin (MTM) biosynthetic pathway, and to discover the interaction between MtmW and MtmOIV.

MtmW is an aldol-ketoreductase responsible for reducing the most distal carbonyl on the MTM pentyl side chain. It forms an octamer that …

Investigation Of The Biosynthesis Of The Nucleoside Antibiotic Sphaerimicin, Jonathan Overbay

Theses and Dissertations--Pharmacy

Antibiotic-resistance has become a widespread problem in the United States and across the globe. Meanwhile, new antibiotics are entering the clinic at an alarmingly low rate. Highly-modified nucleosides, a class of natural products often produced by actinobacteria, target MraY bacterial translocase I. MraY is a clinically unexploited enzyme target that is ubiquitous and essential to peptidoglycan cell wall biosynthesis. The nucleoside antibiotics known vary in efficacy and the functionalities contributing to improved activity is poorly understood. Sphaerimicin, a newly discovered modified nucleoside, has potent inhibitory activity with an IC50 of 13.65 nM against MraY. In general, sphaerimicin is primarily effective …

Elucidating The Role Of The Tyrosine Phosphatase, Shp-2, In Regulation Of Pd-L1 Expression In Non-Small Lung Cancer Using Both Biochemical Analyses And Real-World Genomic Information, Keller Toral

Theses and Dissertations--Pharmacy

Immune checkpoint inhibitors (ICIs), especially those that target programmed cell death protein 1 (PD-1) and programmed cell death ligand-1 (PD-L1), have been shown to provide substantial clinical benefit in many patients with non-small cell lung cancer (NSCLC). While these therapeutic agents can be highly effective in the correct context, the biological systems that malignant cells draft from normal activities of the cell are poorly characterized. Tumor cell-specific expression of PD-L1 is likely important for clinical benefit from PD-1 and PD-L1 inhibitors. It is known that PD-L1 is inappropriately expressed in many cancers harboring mutations in the RAS family of genes. …

Towards A Holistic Risk Model For Safeguarding The Pharmaceutical Supply Chain: Capturing The Human-Induced Risk To Drug Quality, Heather R. Campbell

Theses and Dissertations--Pharmacy

Counterfeit, adulterated, and misbranded medicines in the pharmaceutical supply chain (PSC) are a critical problem. Regulators charged with safeguarding the supply chain are facing shrinking resources for inspections while concurrently facing increasing demands posed by new drug products being manufactured at more sites in the US and abroad. To mitigate risk, the University of Kentucky (UK) Central Pharmacy Drug Quality Study (DQS) tests injectable drugs dispensed within the UK hospital. Using FT-NIR spectrometry coupled with machine learning techniques the team identifies and flags potentially contaminated drugs for further testing and possible removal from the pharmacy. Teams like the DQS are …

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 …

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 …

Environmental Respiratory Exposures And Pulmonary Function Among Residents Of Rural Appalachia, Kentucky, John C. Flunker

Theses and Dissertations--Epidemiology and Biostatistics

Introduction

Resource extraction exposures are hypothesized to promote adverse respiratory health outcomes among residents of rural Appalachia, yet no studies to date have simultaneously quantified small-scale geographic variation in residential exposure, individual level health factors, and respiratory health outcomes.

Methods

The Mountain Air Project (MAP) is a community engaged cross-sectional study based in Harlan and Letcher counties of Southeastern Kentucky. MAP utilized a novel small-scale method to define residential exposure boundaries: hydrologic unit code (HUC), which represents distinct drainages (AKA “hollows”) where residents cluster. We assigned the HUC level density of active and abandoned surface and underground mining, oil/gas wells, …

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 …

Investigation Of Coal Burst Potential Using Numerical Modeling And Rock Burst Indices, Cristian David Cardenas Triana

Theses and Dissertations--Mining Engineering

Coal bursts are typically defined as a rapid failure of coal or surrounding rock producing a violent release of energy and ejection of rock particles. This phenomenon is extremely complex and dynamic, and this has made it very difficult to predict. In the last decades, different researchers have aimed to understand the sources and mechanisms of failure of coal bursts. Various indices have been developed to assess the burst potential such as the Burst Potential Index (BPI), Energy Storage Rate, and the Strain Energy Density. Lately, numerical modeling has also been used as a tool to examine the rock deformation …

An Approach For Predicting Flow Characteristics At The Continuous Miner Face, Kayla Henderson

Theses and Dissertations--Mining Engineering

As coal and rock are mined, dust is dispersed into the air. This dust, among other contaminants, poses a serious health and safety risk to mineworkers. Very fine dust known as respirable dust can infiltrate the deepest part of the lungs, and long-term exposure to these particles leads to a disease called coal worker’s pneumoconiosis (CWP). Occurrence of this disease declined steadily over the latter half of the 20^th century; however, a recent study indicates that CWP has reemerged with an upward trend beginning at the turn of the century. To combat dust exposure, mine operators use a combination …

Application Of A Novel Ventilation Simplification Algorithm, Caitlin V. Strong

Theses and Dissertations--Mining Engineering

Ventilation network analysis is an integral part of maintaining a safe mine environment. Despite its important role, liberties are often taken with the representation of networks in ventilation network analysis software. In order to provide an alternative to heuristic methods used by ventilation engineers, a simplification algorithm has been developed. This algorithm is designed to work as a compliment to ventilation software. Comparisons of original ventilation networks and simplified networks show little to no change in fan operating point. The program utilizing this algorithm provides an alternative to reducing networks with a parallel factor. It can also be used in …

Concepts For Development Of Shuttle Car Autonomous Docking With Continuous Miner Using 3-D Depth Camera, Sibley Miller

Theses and Dissertations--Mining Engineering

In recent years, a great deal of work has been conducted in automating mining equipment with the goals of increasing worker health and safety and increasing mine productivity. Automating vehicles such as load-haul-dumps been successful even in underground environments where the use of global positioning systems are unavailable. This thesis addresses automating the operation of a shuttle car, specifically focusing on positioning the shuttle car under the continuous miner coal-discharge conveyor during cutting and loading operations. This task requires recognition of the target and precise control of the tramming operation because a specific orientation and distance from the coal discharge …

Prediction Of Noise Emissions Using Panel Contribution Analysis Supplemented With Scale Modeling, Gong Cheng

Theses and Dissertations--Mechanical and Aerospace Engineering

Panel contribution analysis (PCA) can be used to predict machinery noise emissions, component contributions, and to assess the impact of sound reduction treatments. PCA is a measurement approach that is advantageous for complex machinery that is not easily modeled using conventional numerical analysis approaches. In this research, PCA is combined with scale modeling in order to speed up the necessary measurement work. Moreover, the method can be applied to much larger machinery and noise emissions can be assessed prior to locating and installing the equipment. This eliminates the necessity to use voluminous anechoic chambers.

The machinery is first discretized into …

Tailoring Texture, Microstructure, And Shape Memory Behavior Of Niti Alloys Fabricated By L-Pbf-Am, Sayed Ehsan Saghaian N.E.

Theses and Dissertations--Mechanical and Aerospace Engineering

Laser Powder Bed Fusion (L-PBF) is one of the most promising Additive Manufacturing (AM) methods to fabricate near net-shape metallic materials for a wide range of applications such as patient-specific medical devices, functionally graded materials, and complex structures. NiTi shape memory alloys (SMAs) are of great interest due to a combination of unique features, such as superelasticity, shape memory effect, high ductility, work output, corrosion resistance, and biocompatibility that could be employed in many applications in automotive, aerospace, and biomedical industries. Due to the difficulties with traditional machining and forming of NiTi components, the ability to fabricate complex parts, tailor …

Turbulence Suppression In An Axially Rotating Pipe, Alyn J. Smith

Theses and Dissertations--Mechanical and Aerospace Engineering

The phenomenon of turbulence suppression in a rotating pipe flow system has been well documented by past research and experimentation. Despite this, the methods that drive this phenomenon have not yet been effectively characterized, especially at higher Reynolds numbers. While many experiments have been performed to better understand swirling turbulent pipe flow, a difficulty that arises is how to test for high levels of rotation without reducing the Reynolds number. This thesis documents the design and construction of a new pressurized pipe flow system at the University of Kentucky aimed at achieving high Reynolds numbers without causing a reduction in …

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 …

Experimental Investigation Of Image Distortion In A Mach 6 Hypersonic Flow, Ricky W. Green Ii

Theses and Dissertations--Mechanical and Aerospace Engineering

The image distortion that is inherently present when imaging through a flow field at hypersonic speeds was investigated. The original problem involves observation of the outside world from the inside an aircraft moving at hypersonic speeds. For this work, a Mach 6 hypersonic wind tunnel at Wright Patterson Air Force Base (WPAFB) was used and optical patterns were imaged with and without flow field characteristics. Two test campaigns were scheduled to conduct experiments that would provide answers to the proposed problem of the effect on observable aberrations through flow fields.

During the first test campaign, October 2017, optical patterns were …