Digital Commons Network^™

Statistical Classification Using Selection And Ranking Methodologies With Statistical Learning, Jeong Jun Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

The subject of Statistical Classification is concerned with identifying and allocating future observations into one of the pre-categorized classes based on the characteristics of the objects. Typically, these decisions to classify and categorize the objects have been dependent on identifying a system of classification, and from there, determining attributes for sorting.

In past decades, from discriminant analysis, various methods have been developed for classification. In particular, the rise of artificial intelligence (AI), machine learning, and statistical learning theory has made it possible to consider improving the existing methods along with new developments and more comprehensive schemes in conjunction with data-driven …

Self-Perception And Positive Stereotype Endorsement, Aileen Lovitt

UNLV Theses, Dissertations, Professional Papers, and Capstones

The origin and reasoning behind the use of racial stereotypes has been a point of interest for researchers over the years. Many different theories have been proposed including those related to cognitive, evolutionary, and motivational explanations. However, most of these theories and the research backing them primarily focus on negative stereotyping. The origin of positive stereotyping, which also has negative implications associated with their use, has not been evaluated fully. Previous research has suggested that the motive to preserve self-worth and positive self-concept may play a role in stereotype endorsement. Two studies were conducted with the purpose of investigating whether …

The Mitochondrial Membrane Potential As A Screening Tool For Immunostimulation, Kendra Mcglothen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The rise of neuroinflammatory disorders highlights the importance of early detection and intervention for more effective treatment options. Neuroinflammation is associated with the pathogenesis of many neurological disorders, including Major Depressive Disorder, Alzheimer's disease, and Multiple Sclerosis. There has been a focus on neurons to advance our understanding of the underlying mechanisms of neuroinflammation and its role in neurodegeneration. However, recent studies have highlighted the pivotal role of glial cells, particularly microglia, in neuroinflammation due to their active participation in the immune response. This study investigates glial-specific indicators of morphology, metabolic changes, and drug efficacy in neuroinflammatory conditions. By analyzing …

Age, Gender, And Sexual Orientation And Their Effects On Online Dating Motivations, Jenna Leigh Mcpherson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Online dating and dating apps are becoming more common as a means to meet a romantic or sexual partner (e.g. Rosenfeld, Thomas, & Hausen, 2019). Previous literature on the motivations for why people use dating apps and how they differ among participants of varying age, gender, and sexual orientation has not allowed for comparisons across these groups, or shows conflicting findings. In order to consolidate existing literature and further explore the topic, I conducted both a meta-analysis and meta-synthesis. The meta-analysis demonstrated a gender difference in the motivation of casual sex, such that men scored higher than women. The meta-synthesis …

Investigations Into The Relationship Between Menopause And Alzheimer’S Disease Pathology In A Mouse Model With Ovarian Follicle Depletion, Amanda M. Leisgang Osse

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s Disease (AD) currently affects about 6.9 million Americans, with over two-thirds of those individuals being women. Interestingly, changes in the brain indicative of AD coincide with the onset of menopause. Post-menopausal women have significantly higher levels of AD pathologies, including amyloid beta and hyperphosphorylated tau, than pre-menopausal women. To investigate the relationship between AD pathologies and menopause, we induced menopause-like state in an AD mouse model, APP/PS1, by treatment with 4-vinylcyclohexene diepoxide (VCD) to accelerate ovarian follicle depletion. To monitor the transition to menopause, vaginal lavages and cytology was performed to determine if mice reached anestrous. Both female APP/PS1 …

Examining The Risks And Resilience Of Older Adults Living With Hiv/Aids: Qualitative Community-Based Participatory Research Studies In Southern Nevada, Brandon Ranuschio

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the height of the HIV pandemic in the 1980s, medical interventions have significantly increased the life expectancy of people living with HIV/AIDS (PLWH) and made HIV/AIDS a livable, chronic health condition. Because of this, PLWH have been living longer lives and thriving with the help of HIV sector healthcare and service providers. However, with their longer life expectancy, older PLWH have been experiencing other health challenges. One such challenge is the risk of developing HIV-Associated Neurocognitive Disorder (HAND), which is a condition that affects up to 50% of PLWH at some point in their lifetime, with middle-aged and older …

Enhancing The Relationships Between Students With Emotional And Behavioral Disorders And Their Teachers, Jack Watts

UNLV Theses, Dissertations, Professional Papers, and Capstones

Outcomes of students with emotional and behavioral disorders (EBD) have failed to meet the standards of educators and educational researchers. For several decades, such students have had worse academic and postsecondary outcomes than any other student population. This has led to emphasis on implementation of evidence-based practices to combat the negative outcomes associated with educational diagnoses of EBD (i.e., behavioral outbursts, suspension, and expulsion). Despite this increased attention, little improvement has occurred, leading to the question of whether practices implemented for students with EBD have been addressing the underlying causes of these students’ negative outcomes. Student–teacher relationships could be an …

Understanding Disk Substructures With 3d Self-Consistent Thermodynamics, Shangjia Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Protoplanetary disks are birthplaces of planets. The past decade witnessed a great advance- ment in disk observations by Atacama Large Millimeter Array (ALMA) and extreme adaptive optics (ExAOs). Hundreds of disks have been observed at high angular resolutions and revealed rich substructures (e.g., gaps/rings) at midplane and atmosphere, at least part of which are per- turbed by planets. Deep understanding of disk physics has a great potential to unveil more young planets from substructures and distinguish those that are not caused by planets. I worked on con- straining young planet populations using planet-disk interaction simulations and substructures and self-consistent treatment …

A Low Dose Of Electro-Psychedelic Treatment Increases Neuronal Dendritic Arborization And Filopodic Spine Density, Elaine Aquino Vasquez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neuropsychiatric disorders remain a formidable challenge to the global healthcare system, necessitating innovative treatments to address their complex pathophysiology. Alternative therapeutic approaches, including electroconvulsive treatment (ECT) and psychedelics, have gained attention for their capacity to relieve a broad range of symptoms. ECT is a long-standing effective therapy for patients, especially treatment-resistant ones. Psychedelics, like psilocybin, can induce profound and sustained therapeutic effects. The limited understanding of their mechanisms of action, compounded by the negative stigma surrounding ECT and psilocybin, prevents them from being used as adjunct agents. ECT and psilocybin promote synaptic plasticity and modulate neural remodeling, yet their comparative …

Factors Shaping Charter School Leaders’ Student Recruitment Practices In Southern Nevada, John E. Aydogdu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Charter schools have witnessed significant growth in the United States, accompanied by increased diversity among student populations. However, Southern Nevada charter schools diverge from national trends, enrolling a less racially and socioeconomically diverse student population. This study examined factors that shape charter school leaders’ student recruitment practices in Southern Nevada. In addition to addressing the lack of literature coverage on Southern Nevada charter schools’ demographics, this study also introduced new research regarding the predicament of charter school demographics in Southern Nevada. Using a case study approach, data from 16 charter school leaders and staff members across four identified charter schools …

Black Women Educational Leaders In Pk-12 Public Education: A Multiple Case Study On The Double Consciousness Of Black Women Educational Leadership In Southwestern United States, Malena Baizan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation examined the stories of Black Women Educational Leaders (BWEL) in PK-12t public education and their double consciousness as expressed through their leadership. The focus of this study was BWEL’s counternarratives as leaders within a system built upon systemic racism and oppression. Their experiences as Black Women Educational Leaders in PK-12 in a school district in which most school administrators are white, but most of the student body is Black and Brown were highlighted and centered to shed light on how the double consciousness of Black women informs their leadership. Utilizing Critical Race Feminism as the theoretical framework with …

Differential Expression Of Microrna Mir-145 And Mir-155 Downstream Targets In Oral Cancers Exhibiting Limited Chemotherapy Resistance, Conner Belnap

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: New evidence has suggested that non-coding microRNAs play a significant role in mediating and modulating chemotherapy resistance, particularly among oral cancers. One recent study found that the expression of miR-145 and lack of miR-155 expression strongly correlated with a limited chemotherapy resistance to Cisplatin, 5-Fluorouracil and Paclitaxel , although the mechanism(s) responsible for these observations remain unidentified.

Methods: Using commercially available cell lines of oral squamous cell carcinoma (OSCC), RNA was isolated using phenol:chloroform extraction. The isolated RNA was converted into cDNA by reverse transcription and subsequently screened for the presence or absence of downstream targets of miR-145 and …

An Examination Of The Teaching And Learning Of Resonance In General Chemistry I And Organic Chemistry I Using Variation Theory, Sabrina Barakat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Resonance is a fundamental chemistry concept first introduced to students in General Chemistry I, reintroduced in Organic Chemistry I, and then utilized throughout other higher-level chemistry courses. A molecule or ion can be said to exhibit resonance when it can be represented by two or more chemical structures (i.e., Lewis structures) that differ only in their arrangement of electrons. In other words, resonance represents the electronic structure of a molecule or ion when a single Lewis structure does not adequately depict the true distribution of electrons. The molecule or ion is best represented as a combination of all of the …

Heat Transfer Enhancement In Heat Exchangers Using Compound Enhancement, Mouhsine Benmbarek

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research will try to investigate the enhancement of heat transfer in a heat exchanger that is made of a corrugated tube that has a twisted plate inserted in it, the corrugation, and twisted plate are expected to increase the amount of heat transfer since the plate is acting as a connection between the center of the flow and the edges of the tube. The turbulence will cause an increase in pressure drop along the channel length, so the investigation will try to find the best compromise between the gain in heat transfer and loss of hydraulic energy by using …

The Influence Of Dual Sources Cerebellar Transcranial Direct Current Stimulation On Muscle Fatigue, Janriek Asuncion Bognot

UNLV Theses, Dissertations, Professional Papers, and Capstones

Transcranial direct current stimulation (tDCS) applied unilaterally to the cerebellum (ctDCS) can improve several aspects of human motor performance. The purpose of the study was to examine the influence of dual source tDCS delivered bilaterally over the cerebellar cortices (dsc-tDCS) on the time to task failure (TTF) of a fatiguing contraction. The study utilized a double-blind, randomized, SHAM-controlled, within-subjects, crossover design and participants were given either dsc-tDCS or SHAM stimulation in two different experiments held 7 days apart. Every aspect of the two experiments was the same except the type of stimulation (dsc-tDCS or SHAM) delivered during the fatiguing contraction. …

Assessing The Potential For Magmatic Sulfides Within Southwestern Laurentia Large Igneous Province, Thomas J. Boes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ~1.1 Ga magmatism of the Southwestern Laurentia Large Igneous Province (SWLLIP) generated a series of mafic-ultramafic sheets, sills, and dikes emplaced within Mesoproterozoic sedimentary units and older crystalline basement rock throughout the southwest United States and northern Mexico. This large igneous province (LIP) event remains enigmatic in identifying the processes that generated this magmatism. In addition, potential links to the contemporaneous magmatism of North America's magmatic Ni-Cu-platinum group element (PGE) mineralized Mid-Continent Rift (MCR) LIP to the northeast of the SWLLIP remain unclear. The contemporaneous 1.1 Ga MCR LIP event hosts economically viable magmatic sulfide deposits in the Duluth …

Evaluation, Rating, And Numerical Modeling Of A Shock Mitigation Seat For High-Speed Craft Based On Laboratory Single Impact Testing, Darren Benn

UNLV Theses, Dissertations, Professional Papers, and Capstones

High-speed craft (HSC) are utilized in military and para-military maneuvers that are usually conducted in harsh environments. The Special Warfare Combatant-craft Crewmen (SWCC), a sub-unit of the United States Naval Special Warfare Command (NAVSOC), use an advanced HSC, known as the Combatant Craft Assault, to conduct coastal patrol and interdiction, and for infiltration and exfiltration of Navy SEALs. The United States Coast Guard, and the Drug Enforcement Agency (DEA), employ HSC for maritime patrol and to pursue ‘go-fast’ boats operated by contraband runners. In most of these intense applications, the mode of operation of the HSC results in planing. Planing …

Seasonal Climate And Environmental Conditions Associated With Physiological Variations Of Southwestern United States Pines, Taylor Brewer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Juvenile and adult conifers in the southwestern United States are vulnerable to a range of different abiotic and biotic factors, yet it is unclear how their stress tolerance varies across environments. Predicted increases in the frequency and intensity of disturbance as well as greater climate and weather variability across the region highlight the potential for differential physiological responses across tree species and populations. This thesis focuses on two physiologic mechanisms, hydraulic vulnerability and mortality, that could be altered by climate change in two broadly distributed southwestern United States conifers: ponderosa pine and pinyon pine.

In chapter 2, I measured the …

Exploring Intention Mapping And Action In Pursuit Of Emotional Storytelling For Musicians, Douglas Carpenter

UNLV Theses, Dissertations, Professional Papers, and Capstones

This document presents a novel approach to music education by integrating acting pedagogies, specifically the concepts of "Intention" and "Action," to enhance the expressive capabilities of musicians. Rooted in the methodologies of Konstantin Stanislavski, Sanford Meisner, and Michael Chekhov, this research seeks to bridge the gap between traditional music education, which often emphasizes technical execution, and the need for emotional expressivity and storytelling in musical performances.

The role of the musician as a 'human instrument,' capable of conveying complex human emotions and narratives through music is explored in this document. Drawing from acting techniques, the document proposes methods to help …

The Influence Of Bihemispheric Transcranial Direct Current Stimulation On Muscle Fatigue, Ananya Singh Chauhan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Unilateral transcranial direct current stimulation (tDCS) using two electrodes placed over the primary motor cortex (M1) and the contralateral supraorbital (SO) region (M1-SO montage) has been shown to decrease the progression of muscle fatigue. The primary purpose was to determine the impact of bihemispheric tDCS (bi-tDCS) applied over the left and right M1s (bi-tDCS) on the time to task failure (TTF) of a precision-grip task. The study implemented a double-blind, randomized, SHAM-controlled, within-subjects design. A total of 20 participants performed two experimental sessions (bi-tDCS and SHAM conditions) separated by a one-week washout. During each experimental session, a fatiguing isometric contraction …

Understanding Stress And Coping Among Adults In The United States During The Covid-19 Pandemic, Jocy-Anna Chevalier

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the COVID-19 pandemic started, individuals in the United States (U.S.) and across the globe have experienced unprecedented levels of stress. The purpose of this study is to understand the stress experienced among adults in the U.S. and which coping processes affect their overall emotional well-being. Guided by Lazarus and Folkman’s (1987) Transactional Model of Stress and Coping (TMSC), this study conducted a secondary data analysis (n=404) of adults across the U.S who completed an online survey examining their experiences with stress and coping. A Pearson correlation was utilized to explore the relationship between stress and depressive symptoms. Paired samples …

The Influence Of Bilateral Dual Source Transcranial Direct Current Stimulation On The Progression Of Muscle Fatigue, Eliza Clinton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Transcranial direct current stimulation (tDCS) applied unilaterally to the primary motor cortex (M1) can significantly prolong the time to task failure (TTF) of a fatiguing contraction. The primary purpose of the study was to examine the influence of bilateral dual source tDCS (dstDCS) applied over the left and right M1s (ds-tDCS) on the TTF of a precision grip task. This was accomplished through the utilization of a double-blind, randomized, SHAM-controlled, within-subjects design. Fourteen participants completed two experiments (ds-tDCS and SHAM stimulation conditions) with a seven-day washout period between sessions. Each experiment involved the performance of a sustained isometric fatiguing contraction …

Using Student Voices To Inform Educational Reform: Exploring High School Educational Desires To Improve Curricular Decisions, Anna Colquitt

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the education system, the integration of student perspectives into effective pedagogical strategies is gaining momentum. This dissertation delves into the concept of 'Student Voice' and its role in shaping educational frameworks. Recognizing the growing gap in soft skill proficiency among newly recruited employees, contrasted with the emphasis on hard skills within current educational standards, this study analyzes what those skill gaps are in the education and what skills students perceive are necessary to integrate into a high school education to better prepare students for life, the workforce, and higher education. Focused on recent high school graduates in Nevada, the …

Investigating Controls On Temporal And Spatial Variation Of Dissolved Uranium At Springs In Horn Creek Drainage, Grand Canyon National Park, Arizona, Usa, Collin Davidson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater is a critical resource in the Grand Canyon, providing water to local communities, millions of annual visitors, and ecosystems. One major concern for this critical resource is the potential for uranium contamination in conjunction with uranium mining efforts. Upper Horn Bedrock Spring (UHB) in the Horn Creek drainage of the Grand Canyon sits below the oldest uranium mine in the region, Orphan Lode mine. UHB spring contains the highest concentration of dissolved uranium in the region, eclipsing the Maximum Contaminant Level (MCL) set by the USEPA by an order of magnitude on average. This research and recent collaboration with …

Experiment Development And Validation Of A Granular Jamming Robotic Gripper, Jacob R. Dowd

UNLV Theses, Dissertations, Professional Papers, and Capstones

A granular jamming gripper (GJG) is widely known as a Universal Gripper because of the wide range of objects that it can grasp and the simplicity of control, design, and manufacturing. Despite multitude of research improving the GJG, here, we focus on the base version of the GJG and attempt to glean the range of objects that it may reliably grasp. Despite the limited range of objects, which were a sphere, rectangular prism, and cylinder, we gleaned geometric properties as it relates to successful and unsuccessful grasping. This was based on the two types of testing: push and pull testing …

Causal Attribution Tendencies Of Early Childhood Practitioners And The Efficacy Of Attribution Retraining, Alex J. Faucheux

UNLV Theses, Dissertations, Professional Papers, and Capstones

Early childhood practitioners frequently attempt to identify the cause of outcomes experienced by their learners. This is sometimes referred to as causal attribution. Causal attribution may be affected by prior success and failure of a learner, the amount of effort exerted by the learner, the ability level of the learner, and knowledge of any disability associated with the learner, all of which can be considered controllable or uncontrollable, stable or unstable, and internal or external (Weiner, 1986; Woodcock & Vialle, 2011). As practitioners attribute cause to outcomes, they start to develop attributional tendencies; these tendencies, along with the cues and …

An Analysis Of Truancy Causes And Prevention Programming In Clark County, Nevada, Jennifer Ashley Fletcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the United States truancy prevention is lacking two key elements to success; research that explains the causes of truancy and empirical evidence for best practices of truancy prevention. Truancy has been a problem in academics since the early 1900’s, when truancy became illegal. Since then, truancy rates have continued to see a steady increase, and today approximately 10% of public school students in the United States are truant every day (Maynard et al., 2017). To combat this problem, research needs to be conducted to understand why truancy happens. However, there is a severe lack of research on this topic; …

The Effect Of Dual Source Premotor Cortex Transcranial Direct Current Stimulation On Muscle Fatigue In Hand Muscles, Valentino Contini

UNLV Theses, Dissertations, Professional Papers, and Capstones

Single source transcranial direct current stimulation (tDCS) has been shown to increase the time to task failure (TTF) fatiguing contractions when applied to the dorsolateral prefrontal cortex (DLPFC) and to the primary motor cortex (M1). The primary purpose was to determine whether dual source tDCS delivered bilaterally over the premotor cortices (pmc-tDCS) could increase the TTF of a fatiguing contraction performed by hand muscles. A double-blind, randomized, SHAM-controlled, crossover design was used for this study with each participant performing two experimental sessions held on separate days a week apart. The only difference between the two sessions was the type of …

Remote Detection Of Leaks In High Level Waste Storage Tanks, Hunter Frey

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to characterize three devices potentially capable of remotely detecting signatures of a leak from high-level waste (HLW) storage tanks, specifically ones found at the Savannah River Site and the Hanford Site. The hazard HLW found within these tanks include ¹³⁷Cs, a gamma-ray emitter, and ⁹⁰Sr, an electron emitter leading to heat generation. These pose health risks to the personnel and maintenance problems and environmental safety issues if released to the environment. Additionally, pinpointing the location of a leak is a task that could lead to the mitigation of excess waste leaking from …

Predicting The Response Of An Underactuated, 3d Printed Prosthetic Hand, Lucas Gallup

UNLV Theses, Dissertations, Professional Papers, and Capstones

The continuing need for hand prostheses has led to incredible developments in this area. However, due to the cost of the most sophisticated models, it is vital to develop simpler, low-cost, underactuated prostheses that can be produced rapidly. 3D printing is an important tool to achieve this goal. In particular, the 3D printed Flexy-Hand 2 has been one of the most common low-cost designs. A key feature of the Flexy-Hand 2 is its use of tendons and thermoplastic polyurethane (TPU) for joints that are strong and flexible. TPUs, however, lack a thorough understanding of their mechanical behavior, which makes it …