Digital Commons Network^™

Exploratory Case Study Of Freshman Student Experiences In Developmental Education Courses That Encourage Persistence At One College In West Texas, Brandon A. Hernandez

Electronic Theses and Dissertations

The purpose of this study was to explore freshman student experiences in developmental education courses that encourage their persistence at one college in the West Texas region. More specifically, this study focused on the programs and services that benefit freshman community college students enrolled in developmental education courses. This study followed case study methodology to examine the student experience. The data were collected by way of personal interviews with students and employees that lasted on average of 45 minutes via the software Webex. The interviews were all conducted online from one community college in the West Texas region. Participants were …

The Impact Of A 1:1 Technology Initiative On Student Achievement In 10th Grade English Language Arts In A South Texas Public School District, Lois E. Marshall Barker

Electronic Theses and Dissertations

This study investigated the implementation of a south Texas public school district’s 1:1 technology initiative to determine the impact on 10th grade English Language Arts student achievement. A mixed method approach was used for this exploratory case study. Multicase sampling was implemented to identify participants. Qualitative data were collected through virtual video conference interviews and analyzed to reflect five emerging themes: lack of quality professional development, teacher efficacy, leadership attitudes toward the initiative, misconceptions about student attitudes and technology skillset, and lack of communication between district administration campus stakeholders. Quantitative data were collected through the CBAM SoCQ and archival campus …

Persistence And Retention Strategies Implemented At Hbcus That Support Successful Degree Attainment Of African American Men, Fetera D. Henry

Electronic Theses and Dissertations

While minority students are enrolling in college at record numbers, their completion rate is significantly lower than their Caucasian peers. This gap is particularly evident among African American men. The purpose of this study was to identify and describe persistence and retention strategies implemented by HBCUs which support successful degree attainment of African American men. Framed by Tinto’s model of institutional departure, a descriptive instrumental case study design utilized data from semistructured online interviews and voluntarily submitted artifacts to explore the academic and social experiences of nine African American men who successfully completed a degree from an HBCU within the …

Std Prevention: An Educational Intervention For Exotic Dancers, Maria Delurdes Dehoyos

Electronic Theses and Dissertations

The Centers for Disease Control and prevention reported nearly 2.3 million STD cases diagnosed in 2017, and the number is continuing to rise. San Antonio, Texas, is ranked third in the state of Texas with the highest STD rates and leading in the state with congenital syphilis. There is an increased risk for contracting STDs working in the sex industry. There are little to no studies pertaining to any educational interventions offered to exotic dancers to increase personal knowledge on STDs. This research has focused on an educational intervention offered by a nurse practitioner to exotic dancers in two adults-only …

Photoassisted Synthesis Of Complex Polyheterocycles Via Rational Design Of Tailored Photoprecursors, Tina Alanna Holt

Electronic Theses and Dissertations

Natural products remain the most common source for drug leads, although diversity-oriented synthesis of unnatural complex molecules is gaining momentum. Our lab has been developing experimentally simple and straightforward approaches to complex molecular architectures via photochemical reactions involving a minimal number of experimental steps. In order to achieve this, photoprecursors were assembled via high yielding reactions. Next, we deployed photoinduced cycloadditions to create complex 3-dimentional structures. Lastly, with this obtained primary photoproduct, post-photochemical transformations were used to further grow its scaffold complexity.

One method to increase scaffold complexity is the [4+2] intramolecular cycloadditions of azaxylylenes, which are developed through standard …

Moving Past ‘One Size Fits All’: Developing A Trajectory Deviance Index For Dynamic Measurement Modeling, Yixiao Dong

Electronic Theses and Dissertations

Dynamic Measurement Modeling (DMM) is a recently developed measurement framework for gauging developing constructs (e.g., learning capacity) that conventional single-timepoint tests cannot assess. Like most measurement models, overall model fit indices of DMM do not indicate the measurement appropriateness for each included student. For this reason, other measurement modeling paradigms (e.g., Item-Response Theory; IRT) utilize person-fit or model appropriateness statistics to indicate whether a measurement model appropriately describes the data from each individual student. However, within the extant DMM framework, no statistical index has yet been developed for this purpose. Thus, the current project advanced a person-specific DMM Trajectory Deviance …

Modeling Disorder In Proteins Yields Insights Into The Evolution Of Stability And Function, Jonathan Huihui

Electronic Theses and Dissertations

The central dogma of molecular biology dictates that a DNA sequence codes for an RNA sequence, which in turn codes for a sequence of amino acids that comprises a protein. Proteins are responsible with performing myriad functions within living organisms and most proteins require a folded structure in order to perform their function. The protein's structure is the direct link from sequence to function. This is known as the sequence - structure - function paradigm. However, this does not mean that the unfolded state is unimportant. In order to properly model the stability of the folded state, one needs to …

Observation Of New Particle Formation In The Northern Hemisphere At Altitude From 4 To 20 Km, Mohamed Saad

Electronic Theses and Dissertations

New particle formation (NPF) is investigated using measurements of aerosol size distributions and meteorological variables made in two continents, including USA and Europe. Despite the considerably different aerosol particle abundances among the sites, a common relationship was found between the characteristics of NPF events and the air mass convective and/or advective transport. CO and O3 act as tracers of tropospheric and stratospheric air, respectively, their statistical relationship can be used to quantify air mass characteristics and origins. The mixing ratio values of CO increased within the upper troposphere layer before/during NPF events, which may serve as an indicator of occurring …

The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann

Electronic Theses and Dissertations

Owing to the geographic isolation and unique climatic conditions which occur in tropical montane forests (TMFs), these systems are highly sensitive to changes in both climate and disturbance. Therefore, as ongoing climate change alters disturbance regimes – potentially facilitating multiple disturbance interactions much greater than that of isolated disturbances – TMFs may be shifted to alternate stable states. However, study of TMF resilience is essentially unknown given the lack of long-term studies in these systems. We address the resiliency of the tropical montane pine forests of the Cordillera Central, Dominican Republic using long-term climate records, remeasured vegetation data, and reconstructed …

Epr Relaxation Of Modified Triphenylmethyl And Nitroxide Radicals, Whylder Moore

Electronic Theses and Dissertations

Trityl and nitroxide radicals are widely used as probes in chemical and biochemical systems. Understanding of factors that impact the electron spin relaxation for these radicals is important for selection of probes and experimental operating conditions. It has been previously reported that ¹³C isotope enrichment of the central carbon of the trityl yields a highly sensitive micro viscosity probe. It was important to characterize the impact of this substitution on the relaxation processes in fluid solution and immobilized samples.

Electron spin relaxation times for perdeuterated Finland trityl 99% enriched in ¹³C at the central carbon (¹³C …

Evaluation Of The Effect Of The Clinical-Decision-Support Systems On Diabetes Management: A Multivariate Meta-Analysis Comparison With Univariate Meta-Analysis, Abdelfattah Elbarsha

Electronic Theses and Dissertations

The advantage of using meta-analysis lies in its ability in providing a quantitative summary of the findings from multiple studies. The aim of this dissertation was first to conduct a simulation study in order to understand what factors (sample size, between-study correlation, and percent of missing data) have a significant effect on meta-analysis estimates and whether using univariate or multivariate meta-analysis would produce different estimates.

The second goal of this study was to evaluate the effect of clinical decision support systems CDSS on diabetes care management by conducting three separate univariate meta-analyses and one multivariate meta-analysis. CDSS are health information …

Notch Regulates Vascular Collagen Iv Basement Membrane Through Modulation Of Lysyl Hydroxylase 3 Trafficking, Stephen J.B. Gross

Electronic Theses and Dissertations

Collagen type IV (Col IV) is a basement membrane protein associated with early blood vessel morphogenesis and is essential for blood vessel stability. Defects in vascular Col IV deposition are the basis of heritable disorders, such as small vessel disease, marked by cerebral hemorrhage and drastically shorten lifespan. To date, little is known about how endothelial cells regulate the intracellular transport and selective secretion of Col IV in response to angiogenic cues, leaving a void in our understanding of this process. Our aim was to identify trafficking pathways that regulate Col IV deposition during angiogenic blood vessel development. We have …

Understanding Patterns And Functional Impacts Of An Invasive Tree And Its Biological Control In A Riparian System, Annie L. Henry

Electronic Theses and Dissertations

Invasive species have become an inextricable part of the landscape, particularly in riparian plant communities, and removal is often a key component of restoration programs. Biological control (biocontrol) is a method of removal that is often both efficient and effective. However, the impact of biocontrol on target species and indirect effects from invasive species removal can be hard to predict. While monitoring the impact of invasive species removal usually involves some species-based assessment such as changes in diversity, historically dominant species or native species, these strategies do not typically provide insight into the mechanisms underlying plant community response to removal. …

Distributed Control, Optimization, And State Estimation For Renewable Power System, Qiao Li

Electronic Theses and Dissertations

The traditional power systems are usually centralized systems, in which the control, operation and monitoring are performed by the centralized control center, e.g., SCADA. However, with the development of renewable energy, power systems are getting more and more distributed. So, it becomes necessary to establish the distributed power system operation methods for these power systems. In this research, the distributed techniques for the renewable power systems are proposed based on the consensus protocol technique from graph theory. These techniques cover the three important problems in power systems, i.e., economic dispatch, state estimation, and optimal power flow. First, the Distributed Economic …

Supporting Ambitious Mathematics Practices In The Face Of School Reform: A Case Study Of High School Leadership, Jacklyn Van Ooyik

Electronic Theses and Dissertations

School leaders—both administrators and mathematics leaders—play a critical role in the instructional improvement of teachers in schools. However, current research in mathematics education has not provided a complete picture of the network of administrators, mathematics leaders, and teachers and their roles in supporting ambitious mathematics practices. The purpose of this case study is to examine how ambitious mathematics practices are developed, supported, and sustained within a high school facing pressures for test score improvement and graduation competencies and the roles and responsibilities of school leaders that contribute to that support. In order to address this issue, my primary research question …

Understanding The Latinx Student Experience In A First-Year, Non-Remedial, Terminal College Math Course: A Convergent Mixed Methods Study, Ross Morgan

Electronic Theses and Dissertations

Working with Latinx students, a semester long study was conducted in the Spring of 2021 to better understand student’s perception of Culturally Responsive Teaching Practices (CRTP) at Mountain State University (MSU). The course sections selected are a part of a larger first year, non-remedial, terminal mathematics courses designed to provide students with smaller teacher to student ratios as well as opportunities to earn credit towards graduation. Instructors in two of the sections received special training around CRTP, while instructors in the other two sections did not receive this training. Findings demonstrate that simple adjustments to instructional practices had a statistically …

Design Of Lower Legs Of Mithra, A High-Performance Backdrivable Humanoid Robot, Drake Taylor

Electronic Theses and Dissertations

This thesis presents the design of the knee and ankle of Mithra, a new humanoid robot that aims to be an energy-efficient and highly agile machine. Mithra makes use of new optimization metrics for legged robots to develop a system capable of mimicking human movement. A series of low-impedance, high-torque actuator systems were developed with the goal of creating lightweight, powerful, and robust motion. The structure of Mithra's legs mimics the human structure in leg segment length and weight proportions. Detailed design and analysis were conducted in order to allow Mithra to be a robust and maintainable system. Mithra will …

Development Of Endoplasmic Reticulum Targeted Probes And Red Fluorescent Probes For Detecting Zinc, Drew Maslar

Electronic Theses and Dissertations

Zinc (Zn²⁺) is the second most abundant transition metal in the body and is important in various biological functions. Fluorescent sensors based on circularly permuted fluorescent proteins (cpFPs) have been previously made to detect labile, or unbound, Zn²⁺ within the cytoplasm of cells. These sensors have proven invaluable for studying Zn²⁺, however, these sensors are limited to their use in the cytoplasm and by the fact that only green cpFP have been utilized to create fluorescent Zn²⁺ sensors. In this thesis, we use a combination of peptide targeting sequences, site-directed mutagenesis, and rational design …

Change Request Prediction And Effort Estimation In An Evolving Software System, Lamees Abdullah Alhazzaa

Electronic Theses and Dissertations

Prediction of software defects has been the focus of many researchers in empirical software engineering and software maintenance because of its significance in providing quality estimates from the project management perspective for an evolving legacy system. Software Reliability Growth Models (SRGM) have been used to predict future defects in a software release. Modern software engineering databases contain Change Requests (CR), which include both defects and other maintenance requests. Our goal is to use defect prediction methods to help predict CRs in an evolving legacy system.

Limited research has been done in defect prediction using curve-fitting methods evolving software systems, with …

The Institutional Design Of Arms Control: To What Extent Does Institutional Design Increase The Longevity Of Arms Control Agreements?, Jessica Budlong

Electronic Theses and Dissertations

The technical institutional design of arms control agreements remains a rather unexplored area of arms control. But the increasing uncertainty of future arms control efficacy requires a re-examination of the agreements’ institutional design to determine which components contribute positively to their longevity. This research examines the role of dispute settlement bodies as specific outside consultative bodies, verification regimes, membership as at least one nuclear-armed state party to the agreement, and technology transfer mechanisms in arms control agreements. It found that membership and a lack of technology transfer mechanisms are necessary to positively impact the longevity of an arms control agreement, …

Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown

Electronic Theses and Dissertations

Protein mass spectrometry (MS) has emerged as a technique to supplant traditional serological tests for body fluid identification. It was hypothesized that proteomic techniques would surpass the sensitivity and specificity of traditional serological techniques. An automated workflow coupled with protein MS has been developed for the confirmatory identification of five biological fluids. A developmental validation was completed, assessing parameters such as reproducibility, sensitivity, ion suppression, and limit of detection. Implementation was determined through tandem sample processing by MS, traditional serological tests, and standard DNA profiling methods. The MS approach offered superior detection limits while also providing true confirmatory results, producing …

Mechanisms Of Sensory Adaptation In The Primate Visual System, Boris Isaac Peñaloza Rojas

Electronic Theses and Dissertations

Under ecological conditions, the luminance impinging on the retina varies within a dynamic range of 220 dB. Stimulus contrast can also vary drastically within a scene, and eye movements leave little time for sampling luminance. In addition, the amount of information reaching our visual system far exceeds the brain’s information processing capacity. Given the limited dynamic range of its neurons and its limited capacity in processing visual information in real-time, the brain deploys both structural and functional solutions that work in tandem to adapt to the surroundings. In this work, employing visual psychophysics and computational neuroscience, we study the mechanisms …

Nucleic Acids Promote Oligomerization Of Immunoglobulin G, Alexa Gomez

Electronic Theses and Dissertations

Nucleic acids have been found to prevent aggregation as chaperones, as well as act as co-factors and promote aggregation of amyloidogenic proteins leading to various diseases. Immunoglobulin G, IgG, are prone to aggregate as therapeutic proteins, and light chains of IgG can form amyloid fibrils, causing a disease known as light chain amyloidosis. Here we discuss the effect nucleic acids have on full-length immunoglobulin G aggregation. Our results show G-quadruplex DNA, and bulk DNA lead to oligomerization of full-length IgG, and induce increases in secondary structure. Tryptophan fluorescence indicates structural changes are occurring in the presence of DNA. Additionally, IgG …

Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin

Electronic Theses and Dissertations

Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …

A Biophysical Investigation Of Hiv-1 Envelope Cytoplasmic-Tail Mediated Retention In The Gag Lattice, Nicholas Scott Groves

Electronic Theses and Dissertations

The infectivity of Human Immunodeficiency Virus is critically dependent on successful incorporation of the trimeric viral envelope glycoprotein, Envelope (Env), into Gag lattice assembly sites on the host-cell plasma membrane during virus biogenesis. The mechanistic nature of interaction between Gag, the structural protein, and Env, the viral spike, are dependent on the Gag matrix (MA) and Env cytoplasmic tail (CT) domains. Env laterally diffuses on the host cell plasma membrane until encountering a budding Gag lattice, where it is retained until particle scission and release. The mechanism of Env entry and retention in the lattice remains elusive and enigmatic. Here …

Statistical Modeling Of Positive Peer Support On Longitudinal Adolescent Substance Use, Kady Rost

Electronic Theses and Dissertations

To evaluate this study’s research question of ”Does the latent construct of Positive Peer Support (PPS) relate to the construct of Adolescent Substance Use (ASU) over time, controlling for neighborhood safety, race, and sex?”, Structural Equation (SEM) and Latent Growth Curve Modeling (LGCM) were used to investigate trajectories. Secondary longitudinal data from Zimmerman (2014) of 604 students enrolled for four consecutive years in public schools located in Flint, Michigan. In the secondary data resource, students who participated were declared “at risk” by GPA. Significant relationships were found in SEM: Positive Peer Support to Adolescent Substance Use, All Control Variables to …

The Combined Impact Of Continuous And Ordinal Auxiliary Variables On Missing Data Imputation In Sem, Salina Wu Whitaker

Electronic Theses and Dissertations

“Modern” methods of addressing missing data using full-information maximum-likelihood (FIML) have become mainstays in SEM analyses. FIML allows the inclusion of auxiliary variables which carry information that is related to missing values and can reduce bias in parameter estimates. Past research has illustrated the benefits of auxiliary variable inclusion under different missingness conditions (MCAR and MNAR; e.g., Enders, 2008), missingness proportions (e.g., Collins et al., 2001), and although limited, missingness patterns (e.g., Yoo, 2009) in FIML analyses. While past studies have focused on the effects of either continuous or ordinal auxiliary variables, no study has included both types in their …

The Orient In The Empire’S Poetry: Scholarship, Translation, And Imaginative Geography (1770-1857), Zeeshan Riyaz Reshamwala

Electronic Theses and Dissertations

This dissertation uses the idea of imaginative geography to study literary and scholarly representations of what writers in Europe referred to as the Orient during the long nineteenth century. Imaginative geography refers to a subjective collection of associations that accumulate around a place about which positive knowledge is limited, such that the imaginative associations overpower and structure any empirical knowledge about it, even when further knowledge is acquired. The imaginative geography of the Orient emerged from texts, images, and artifacts that traveled from Asia to Europe through sustained colonial contact. This dissertation studies how writers in India and Britain constituted, …

The Design, Development, And Determination Of A Virtual Reality Classroom, Victoria Alexxis Reddington

Electronic Theses and Dissertations

The COVID-19 pandemic has radically changed the way students learn and engage with their peers and instructors. Likewise, instructors have had to quickly transform their course materials to suit the online classroom format. Results from a survey of students and instructors at the University of Denver revealed that perceived levels of learning and collaboration were lessened with the transition to online learning. Moreover, the sense of presence in an educational atmosphere with other individuals was reported to be significantly stronger in a real physical classroom, as compared to an online classroom. This thesis therefore seeks to provide a new, alternative …

Correlating With Local Variation In Collagen Level And Mechanical Properties Of The Heart Tissues, Talayeh Tavangar

Electronic Theses and Dissertations

The determination of the myocardium's tissue properties is essential in constructing finite element (FE) models of the heart. To obtain accurate results, especially for functionally modeling the heart, we must determine the tissue properties in-vivo. The calculation of the heart tissue properties remains a challenging area as it is categorized as a heterogeneous, anisotropic, nonlinear soft tissue that undergoes large deformation. In this work, we tried to introduce and evaluated a finite element method to determine the mechanical properties of the cardiac tissue. The introduced method combined a finite element modeling with the experimentally obtained images from the left and …