Digital Commons Network^™

Understanding The Effects Of Complex Topography On Cover Crop Dynamics And Maize Production In Kentucky Agroecosystems, Samuel John Leuthold

Theses and Dissertations--Plant and Soil Sciences

In Central Kentucky, rolling hill cropland presents a number of challenges related to soil sustainability. Increased topographic complexity can lead to increased erosion, inefficient crop nutrient use and increased nutrient loss. Further, grain crop yields can be variable across both space and time in rolling hill fields and are less resilient to changes in weather conditions than flatter, more homogeneous areas. More than 30% of cropland in Kentucky has a slope greater than 3⁰, which means a large swath of the row crop production land in the state is at increased risk of contribution to soil and water resource degradation. …

Genomic Selection Strategies To Predict Grain Yield And Disease Resistance Traits In A Wheat Breeding Program, Virginia Laura Verges

Theses and Dissertations--Plant and Soil Sciences

Genomic selection (GS) is a form of marker-assisted selection (MAS) that simultaneously estimates all locus, haplotype or marker effects across the entire genome to calculate genomic estimated breeding values (GEBVs). Since its inception, it has had the attention of breeders keen on finding tools to accelerate genetic gain and reduce phenotyping costs in the breeding program. A first objective of this study was to evaluate strategies to design the training population (TP) and validating population (VP) to estimate GEBVs for grain yield and agronomic traits for wheat breeding lines. Our results demonstrate that, despite the small family size, an approach …

Optimization Of Gelatin-Based Cellular Coating Of Msc For Myocardial Infarction Therapy, Kara Amelle Davis

Theses and Dissertations--Chemical and Materials Engineering

Cardiovascular disease remains the number one threat to American lives. During an acute myocardial infarction (AMI), blood flow is blocked and results in the formation of scar tissue. As the body’s immune system responds, inflammatory signaling causes an increase in both scar tissue size and the patient’s risk for further chronic heart failure. In order to reduce the risk of continued heart disease inflammatory signaling must be reduced. Stem cell therapies have the ability to alter the immune system’s pro-inflammatory signal. However, stem cell retention is limited due to blood flow shear. Gelatin methacrylate (GelMA) based coatings have been shown …

Fabrication Of Nanoporous Materials For Applications Under Extreme Environments, Maria Kosmidou

Theses and Dissertations--Chemical and Materials Engineering

The study of nanoporous materials has become a key aspect of nanotechnology due to their high surface-area-to-volume ratio, arising from the small size ligaments and pores that form the structure. Sensing, catalysis, micro-electromechanical systems (MEMS), medical applications, and materials for radiation environments are some of the applications for which nanoporous materials are considered great candidates. This work, performed at the Ion Beam Laboratory (IBL) at Sandia National Laboratories (SNL), examines the effect of heavy and light ion irradiation exposure on nanoporous Au. Radiation damage accumulation is observed with real-time recording of the creation, migration, and removal of the radiation-induced defects …

Electrochemical Performance Of Biomass-Derived Activated Carbon Supercapacitor Under Compression, Yulin Zhang

Theses and Dissertations--Chemical and Materials Engineering

Supercapacitors are important energy storage device of high-power density, fast charge/discharge rate, environmental friendliness and long service life. Currently, flexible supercapacitors have attracted widespread interest in academia and industry. Supercapacitors under the action of external force will inevitably cause structural changes, performance degradation and even loss of energy storage and supply functionalities. As the most abundant renewable resource so far, biomass is an important energy source for human survival and development. Most electrode materials for supercapacitors are porous activated carbons, which can be derived from abundant renewable biomass, contributing to the sustainable development of society and environmental protection. This thesis …

Probing The Assembly, Functional Relevance, And Dynamics Of Acra In Multi Drug Efflux In Escherichia Coli, Isoiza Ojo

Theses and Dissertations--Chemistry

Efflux pumps and low permeability of the outer membrane of gram-negative bacteria are major culprits in drug resistance. The most studied of these multidrug efflux pumps is the AcrAB-TolC, a complex of three proteins, the inner membrane transporter AcrB, the periplasmic adaptor AcrA and outer membrane factor TolC. This pump exports a wide range of molecules such as dyes, detergents, and antibiotics out of the bacteria system into the external environment. AcrB and TolC exist as obligate trimers, but the structure of AcrA during the assembly process is not well defined. My research aims to explore the functional and structural …

Design, Synthesis, And Anticancer Properties Of Ru(Ii) Complexes With Organometallic, “Expanded” Bipyridine, And O,O’-Chelating Ligands, Raphael Ryan

Theses and Dissertations--Chemistry

Cancer is a worldwide public health crisis that requires new and improved drugs to be developed to extend survival rates and improve quality of life for the patient. Platinum-based drugs are used in approximately 50% of cancer treatment regimens. These drugs are highly effective in many kinds of cancer; however, cancers can develop platinum resistance and these drugs have troubling side effects that reduced their use and efficacy. To overcome these disadvantages, many other metals have been studied for their anticancer properties. Notably, the anticancer properties of ruthenium-based agents have drawn considerable attention with multiple ruthenium complexes entering clinical trials. …

Himpathy? The Impact Of Defendant Social Status On Perceptions Of A Rape Legal Case, Andrea Pals

Theses and Dissertations--Psychology

There is limited work regarding multiple indicators of social status in the legal system (e.g., power and SES). The present study investigated the influence of defendant social status on case judgments in a first-degree rape case. The experiment used a 2 (defendant power: high vs. low) x 2 (defendant SES: high vs. low) x 2 (participant gender) between-subjects design. A sample of 282 community members were recruited via Amazon’s Mechanical Turk. Participants were presented with a case summary, asked to make guilt and credibility judgments, complete the system justification gender scale (gender SJ: Jost & Kay, 2005), and answer standard …

Physiological Stress Responding During Negative Memory Recollection And The Habitual Use Of Psychological Coping Strategies, Kyle P. Rawn

Theses and Dissertations--Psychology

Coping represents an important process for stress: how effectively one copes dictates how a person experiences stress. However, research has not yet examined how a person’s long-term coping habits are related to their physiological stress responding during a particular situation. The current study addresses this through examination of skin conductance level (SCL) trajectories and coping tendencies (i.e. habitual use of coping strategies) during an autobiographical interview. 167 college students completed questionnaires assessing their demographics and their frequency of use for fourteen coping strategies. SCL was collected while participants recalled and discussed a negative family memory from their childhood. Multilevel modeling …

The Role Of Alexithymia And Affective Lability In Disordered Eating Behaviors, Anna Marie Lilia Ortiz

Theses and Dissertations--Psychology

Affective distress may influence eating disorder behaviors in multiple ways. Affective lability refers to the tendency to experience frequent and striking fluctuations in mood. There is considerable evidence that it predicts eating disorder symptoms. Further, alexithymia is characterized by difficulties identifying and describing feelings and an externally oriented thinking style. Alexithymia has also been implicated in the development and maintenance of eating disorders. To date, these risk factors have been studied separately. Given the evidence that both alexithymia and affective lability are affective components associated with eating disordered behaviors, it may be important to examine possible relationships among alexithymia, affective …

How I Can Be Me: Associations Between Presentation Discrepancy And Mental Health Outcomes Among Lgbtq Adults, Samuel Bruun

Theses and Dissertations--Psychology

One’s perception of their own personal appearance, and how one is viewed by others has been previously shown to have an impact on one’s mental health. Whether it be dealing with unrealistic body expectations depicted in the media, or attempting to appear sufficiently masculine, there are a multitude of ways in which one’s appearance can cause distress. Some appearance challenges are more identity specific, such as the struggles that some transgender people experience when attempting to achieve affirming gender presentation. Although these different concerns have been addressed individually in past research, there has not been an attempt to determine how …

Parent School Involvement, Student School Engagement, And Academic Achievement In Children Adopted From Foster Care By Lesbian And Gay Parents, Cassandra P. Vazquez

Theses and Dissertations--Psychology

Sparse research has examined academic outcomes of children adopted from foster care by lesbian and gay (LG) parents. Children who have experienced foster care are at greater risk for negative outcomes, but investment in academic achievement could help buffer potential adversity. Parent and student engagement with school peaks in middle childhood, so this may be an important period for understanding processes that influence academic achievement. This study explores how LG parents (N = 57) of school-aged children (Mage = 10.56 years) adopted from foster care in the U.S. involve themselves in their child’s school, how this involvement may …

Impact Of Ptsd On Hcv/Hiv Risk-Reduction Interventions Among Incarcerated Drug-Using Women In Rural Appalachia, Caitlyn Hood

Theses and Dissertations--Psychology

Justice-involved women in rural Appalachian Kentucky are a particularly vulnerable group in need of targeted risk-reduction interventions for hepatitis C virus (HCV) and human immunodeficiency virus (HIV). Compared to women in the general U.S. population, justice-involved women in rural Appalachia report dramatically higher rates of HCV/HIV risk behaviors (e.g., injection drug use and risky sex), interpersonal violence (IV; e.g., physical, sexual, or emotional abuse), and posttraumatic stress disorder (PTSD). IV and PTSD may exacerbate rural Appalachian women’s risk for contracting and transmitting HIV/HCV, indicating a need to approach HCV/HIV risk-reduction interventions from a trauma-informed perspective.

Brief motivational interviewing and psychoeducation …

Altering The Distance: Using Construal Level Theory To Examine Conciliatory Policy Support, Brandon Reinkensmeyer

Theses and Dissertations--Psychology

Distancing—a cognitive reappraisal strategy—increases conciliatory policy support (i.e., policies redressing inequity) by reducing anger. Related but distinct research has used construal level theory (CLT), which explains the relationship between psychological distance and mental representations (e.g., events and attitudes), to explore intergroup relations. CLT demonstrates increased psychological distance induces abstract thinking, which leads to high-level construal (HLC) mindsets. HLC mindsets, like distancing, decrease political polarization and prejudice toward out-groups. As both distancing (an appraisal technique) and HLC mindsets (a potential outcome of appraisal techniques) may decrease political polarization and prejudice toward outgroups, across two experiments, the present work investigated whether …

Predicting Material Properties: Applications Of Multi-Scale Multiphysics Numerical Modeling To Transport Problems In Biochemical Systems And Chemical Process Engineering, Tom Pace

Theses and Dissertations--Physics and Astronomy

Material properties are used in a wide variety of theoretical models of material behavior. Descriptive properties quantify the nature, structure, or composition of the material. Behavioral properties quantify the response of the material to an imposed condition. The central question of this work concerns the prediction of behavioral properties from previously determined descriptive properties through hierarchical multi-scale, multiphysics models implemented as numerical simulations. Applications covered focus on mass transport models, including sequential enzyme-catalyzed reactions in systems biology, and an industrial chemical process in a common reaction medium.

Analyzing The Effect Of Second-Class Currents On Neutron Beta Decay Observables And The Effect Of Thomas Rotation On The Relativistic Transformations Of Electromagnetic Fields, Lakshya Malhotra

Theses and Dissertations--Physics and Astronomy

The next generation of neutron beta decay measurements will attempt to analyze various beta decay observables of up to O(10^-4) precision. At this level of experimental precision, the effects of second-class currents will contribute theoretical uncertainties to the interpretation of these measurements. Therefore, it is important to investigate the effects of these second-class currents on decay parameters, such as the Fierz interference term b which is linear in beyond standard model couplings. A maximum likelihood statistical framework and Rfit techniques are employed to study these second-class currents effects. Inputs to the Rfit technique are obtained through …

Strongly Correlated Phases In Quantum Hall Systems, Amartya Saha

Theses and Dissertations--Physics and Astronomy

Quantum Hall systems have a one-body energy spectrum consisting of dispersion-less Landau levels. Electron-electron interactions thus dominate in partially filled Landau levels, which exhibit a myriad of strongly correlated phases such as quantum hall ferromagnets and fractional quantum Hall phases. We study two examples of these phenomena.

In the first project, we explore the ground state of a system with an interface between two semi-infinite regions with fillings ν= 4 and ν= 3 respectively. The width of the interface can be controlled by varying the background potential, which provides an additional tuning parameter. For a certain range of …

Effective Field Theory Applications: From Dark Matter To Neutrino Nucleon Scattering, Qing Chen

Theses and Dissertations--Physics and Astronomy

Weakly-interacting-massive-particles (WIMPs) are a large class of viable dark matter candidates. We compute cross sections for electroweak-doublet WIMPs scattering on atomic nuclei, at leading and subleading order using heavy WIMP effective field theory. Neutrino-nucleon charged current elastic scattering is an important process in the detectors of long baseline accelerator neutrino oscillation experiments. We compute QED radiative corrections to this process employing soft-collinear effective field theory.

Topics In Quantum Quench And Entanglement, Sinong Liu

Theses and Dissertations--Physics and Astronomy

The dissertation includes two parts.

In Part I, we study non-equilibrium phenomena in various models associated with global quantum quench. It is known that local quantities, when subjected to global quantum quench across or approaching critical points, exhibit a variety of universal scaling behaviors at various quench rates. To investigate if similar scaling holds for non-local quantities, we consider the scaling behavior of circuit complexity under quantum quench across the critical massless point in Majorana fermion field theory of the one-dimensional integrable transverse field Ising model and find it obeys such scaling. To investigate if similar scaling holds for non-relativistic …

Optical Metasurfaces, Fatih Balli

Theses and Dissertations--Physics and Astronomy

Traditional optical elements, such as refractive lenses, mirrors, phase plates and polarizers have been used for various purposes such as imaging systems, lithographic printing, astronomical observations and display technology. Despite their long-term achievements, they can be bulky and not suitable for miniaturization. On the other hand, recent nanotechnology advances allowed us to manufacture micro and nanoscale devices with ultra-compact sizes. Metasurfaces, 2D engineered artificial interfaces, have emerged as candidates to replace traditional refractive lenses with ultra-thin miniaturized optical elements. They possess sub-wavelength unit cell structures with a specific geometry and material selection. Each unit cell can uniquely tailor the phase, …

Axial Symmetry Tests Of Milky Way Disk Stars Probe The Galaxy's Matter Distribution, Austin Hinkel

Theses and Dissertations--Physics and Astronomy

In Galactic dynamics, various assumptions have been employed for mathematical ease. These assumptions are approximately valid, but departures reveal perturbations on our Galaxy. In this dissertation, we select a complete, Gaia DR2 data set, and using this data, we find evidence for axial symmetry breaking in the Galaxy, away from the spiral arms and the Galactic bar. This asymmetry is compatible with a prolate dark matter halo tilted with respect to the disk, with a long axis pointing in the direction of the Magellanic Clouds, and this matches an inventory of nearby torques. These asymmetries vary North and South of …

Woman To Woman: Community And Belonging Among Lesbian And Queer Feminist Activists In Haifa, Israel, Lauren Copeland

Theses and Dissertations--Gender and Women's Studies

This dissertation focuses on experiences of belonging among lesbian and queer feminist activist women in the women-only organization Isha L’Isha. As the oldest feminist organization in Israel, Isha L’Isha was established in 1983 and has roots dating back to the 1970s. I spent one year (2017-2018) engaging in participant observation and conducting 40 interviews with current and former members of the group. Using Isha L’Isha as a lens through which to examine the multilayered ways in which gendered activism shapes experiences of belonging, this project centers the experiences and narratives of four women: Talma, Sophie, Amira, and Maya.

This work …

Beyond Choice: An Intersectional Analysis Of Identity And Labor In Online Sex Work, Shawna F. Felkins

Theses and Dissertations--Gender and Women's Studies

This intersectional project seeks to understand the complex labor, social lives, and community building of online sex workers. Building on the work of foundational sex work researchers, this project utilizes in-depth interviews, a survey, social media posts, and published writing and research from online sex workers to understand how marginalization and identity impacts participation and success in online sex work. Providing analysis on how race, gender, class, and ability intersect in the digital sexual marketplace, this project critiques the rise of neoliberal feminism in sex work spaces that stems from the centering of white and otherwise privileged sex workers using …

A Case Study To Explore The Perception Of A Woman Participant In Drug Court Of A Community-Based Arts Program On Substance Use Recovery Outcomes, Catherine L. Troop

Theses and Dissertations--Early Childhood, Special Education, and Counselor Education

Addiction to drugs is a complex, chronic, and multi-faceted disease that often involves cycles of relapse and remission. The lifetime prevalence of alcohol and drug use disorders in women in the United States is 19.5 percent and 7.1 percent, respectively (McHugh, Wigderson, & Greenfield, 2014) yet there is a significant dearth of efficacious substance abuse treatment services tailored specifically to women. In addition, literature suggests that the third aspect of Bandura’s Social Cognitive theory (self-efficacy) potentially plays a significant role in abstinence of drug use. The role of art interventions on recovery outcomes for a woman enrolled in the Franklin …

Examination Of Sex- And Limb-Specific Fatigue During Unilateral, Isometric Forearm Exercise, Caleb Christian Voskuil

Theses and Dissertations--Kinesiology and Health Promotion

The purpose of this study was to examine the effects of unilateral, isometric handgrip holds to failure for the dominant (Dm) and non-dominant (NDm) limb on ipsilateral ([IPS] exercised side) and contralateral ([CON] non-exercised side) performance fatigability. Twenty individuals participated in this study (Men [n =10]; Women [n = 10; Composite Demographics: Age: 22.2 years; Height: 174.4 cm; Body Mass: 75.0 kg) and completed three visits. Two, 6 s maximal voluntary isometric contractions (MVICs) for the Dm and NDm limb were performed during visit 1, followed by a familiarization of the fatigue test. Visits 2 and 3 included an isometric, …

Helping The Have-Nots: Examining The Relationship Between Rehabilitation Adherence And Self-Efficacy Beliefs In Acl Reconstructed Naia And Ncaa Dii And Diii Female Athletes, Myles Tutin Englis

Theses and Dissertations--Kinesiology and Health Promotion

Anterior cruciate ligament injuries are among the most common and traumatic sport-related injuries, and often negatively impact one’s quality of life during and post-rehabilitation. For many NCAA Division I and professional female athletes, rehabilitation is streamlined with a multidisciplinary team, including sport psychology. For others (e.g., NAIA, NCAA Division II, III athletes) this may not always be the case, as many of these athletic programs may not have the resources to meet the various needs of injured and rehabilitating female student-athletes. In these instances, rehabilitation motivation, adherence, and success may be more dependent on the athletes’ individual resources and personalities, …

Quadriceps Recruitment And Twitch Properties In Lean And Obese Women Before And After Fatiguing Exercise, Rebekah Seay Carpenter

Theses and Dissertations--Kinesiology and Health Promotion

Skeletal muscle strength, specifically that of the anti-gravitational muscles such as the quadriceps, is essential for performing dynamic tasks including walking, navigating stairs, and transitioning between sitting and standing. Obesity has been shown to negatively impact musculoskeletal function and decrease quadriceps strength relative to body weight. Additionally, obesity has been linked with higher rates of fatigue and lower strength outcomes following a test of muscular endurance of the quadriceps. Since obesity lowers relative strength, it is likely that quadriceps muscle weakness contributes to reduced physical function of dynamic tasks. However, to date, the precise mechanism for obesity-induced muscle weakness has …

Mechanical Deviations And Verbal-Cue Altered Gait In The Femoroacetabular Impingement Syndrome Population, Walter Menke

Theses and Dissertations--Kinesiology and Health Promotion

Femoroacetabular impingement syndrome (FAIS) is an abnormal physical hip morphology that causes functional changes and pain during gait. Mechanical gait differences in this population require further biomechanical investigation to elucidate characteristics unique to this group. Fixed speed gait trials were performed on force plates and analyzed in addition to isokinetic strength testing to find a multitude of biomechanical variables including joint moment, joint power, joint work, and peak joint angle. This work has discovered evidence of muscular deficits at the hip, specifically hip extension, as well as knee joint power contributions to gait when compared to controls. These findings suggest …

Near Conformal Perturbation Theory In Syk Type Models, Sumit R. Das, Animik Ghosh, Antal Jevicki, Kenta Suzuki

Physics and Astronomy Faculty Publications

We present a systematic procedure to extract the dynamics of the low energy soft mode in SYK type models with a single energy scale J and emergent reparametrization symmetry in the IR. This is given in the framework of the perturbative scheme of arXiv:1608.07567 based on a specific (off-shell) breaking of conformal invariance in the UV, adjusted to yield the exact large-N saddle point. While this breaking term formally vanishes on-shell, it has a non-trivial effect on correlation functions and the effective action. In particular, it leads to the Schwarzian action with a specific coupling to bi-local matter. The …

Diverse And Complex Muscle Spindle Afferent Firing Properties Emerge From Multiscale Muscle Mechanics, Kyle P. Blum, Kenneth S. Campbell, Brian C. Horslen, Paul Nardelli, Stephen N. Housley, Timothy C. Cope, Lena H. Ting

Physiology Faculty Publications

Despite decades of research, we lack a mechanistic framework capable of predicting how movement-related signals are transformed into the diversity of muscle spindle afferent firing patterns observed experimentally, particularly in naturalistic behaviors. Here, a biophysical model demonstrates that well-known firing characteristics of mammalian muscle spindle Ia afferents – including movement history dependence, and nonlinear scaling with muscle stretch velocity – emerge from first principles of muscle contractile mechanics. Further, mechanical interactions of the muscle spindle with muscle-tendon dynamics reveal how motor commands to the muscle (alpha drive) versus muscle spindle (gamma drive) can cause highly variable and complex activity during …