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Urban Elementary School Students' Conception of Learning: A Phenomenographic Mapping of Variation (open access)

Urban Elementary School Students' Conception of Learning: A Phenomenographic Mapping of Variation

For decades, urban public schools have been plagued by systemic and structural challenges that continue today. Scholars, policymakers, and the general public have pointed to problems of learning in urban schools and to low expectations for urban students' learning, but little attention has been given to how urban students themselves conceptualize learning. This study sought to fill the void by asking a group of urban students about their views of learning. A phenomenographic approach was employed to examine the qualitatively different ways in which 20 urban elementary fifth-grade students expressed their conceptions of learning and of their learning approaches. Consistent with phenomenography, the study was intended to understand the collective expressions of individuals' conceptions regarding a phenomenon, and emphasis was on the mapping of variation across the conceptions. Semi-structured interviews with open-ended questions, conducted individually, elicited the students' conceptions of the meaning of learning and their learning approaches. In a "search for meaning" approach, analyses were based on students' transcribed responses forming a pool of quotations. These quotations were divided first into "what" and "how" categories—"what" is learning and "how" does learning occur—and then into subcategories. The results were a set of categories organized in a two-level hierarchy. The three …
Date: May 2018
Creator: English, Sherril H
Object Type: Thesis or Dissertation
System: The UNT Digital Library
State Created Danger and Chronic Traumatic Encephalopathy in Texas Schools: A Legal Examination (open access)

State Created Danger and Chronic Traumatic Encephalopathy in Texas Schools: A Legal Examination

The recent breakthroughs in the research of brain trauma as it relates to athletics has revealed never before seen damage linked with football participation. Known as chronic traumatic encephalopathy (CTE), it is caused by activities inherent to the sport of football. School sponsored football has been granted immunity through case law and legislation in Texas. Recent research however indicates a different type of injury than those that school districts have been protected of liability from. This will provide a challenge to the immunity school districts have enjoyed regarding football. One route to abrogation of immunity is the state created danger provision established by the Supreme Court. The Fifth Circuit Court whose jurisdiction includes Texas has yet to officially adopt the state created danger theory. This research examined legal precedent to determine the challenge CTE may present the various layers of immunity surrounding school sponsored football in Texas.
Date: May 2018
Creator: Switzer, Aaron Gray
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Legal Analysis of Litigation against Louisiana Educators and School Districts, Before and After the Louisiana Governmental Claims Act (open access)

A Legal Analysis of Litigation against Louisiana Educators and School Districts, Before and After the Louisiana Governmental Claims Act

This dissertation analyzed court decisions in injuries on school grounds cases under the Louisiana Governmental Claims Act. The question addressed was: How have the Louisiana courts interpreted the Louisiana Governmental Claims Act in litigation against Louisiana school districts and their employees? The intent of this study was to show how Louisiana's legal system has evolved, and how that evolution affected tort cases involving school boards and school board employees. Doctrinal legal research was the methodology used to answer the research question. To limit the number of cases analyzed, this study only focused on tort claims involving injury on school property. In order to gain a broad perspective, tort claims cases filed prior to the 1974 Louisiana Constitution, cases filed after the 1974 Louisiana Constitution, and cases filed after the 1995 Louisiana Liability Limits Amendment, and the Louisiana Governmental Claims Act of 1996 were analyzed. By analyzing the tort claims brought against Louisiana school districts and employees during the various time-periods, it was clear to see how the case rulings reflected the frequent changes of the Louisiana Constitution and its' laws. In the end, the state continued to control who could sue them and how much they would pay in damages.
Date: May 2018
Creator: Price, Charie Wesley
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Geonyong Lee's Violin Works, Rhapsody for Violin and Piano and Heoten Garak: A Study of Compositional Style and Stylistic Influences (open access)

Geonyong Lee's Violin Works, Rhapsody for Violin and Piano and Heoten Garak: A Study of Compositional Style and Stylistic Influences

The purpose of this study is to research the music of Geonyong Lee (이건용), one of the most recognized active Korean composers, while determining Lee's intent to compose with influences from both Western and traditional Korean music. This paper analyses Lee's violin works Rhapsody for Piano and Violin and Heoten Garak, and explains the cultural and historical significance surrounding both works in terms of traditional Korean music. Lee asserts that his primary influence Rhapsody for Piano and Violin was Nongac (농악), a traditional form of Korean farming music. Similarly, Heoten Garak displays a distinct influence of traditional Korean music genres, Heoten Garak and Pansori. By analyzing Geonyong Lee's compositional style and approach to the violin, one learns how his musical philosophies combine Western and traditional Korean music practices into a unique compositional approach. The study concludes by summarizing not only Western and traditional Korean style as evident in his music, but also the conceptual approach by which the composer attempts to bring a unique combination of these influences to his audience.
Date: May 2018
Creator: Cho, Eun
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Orchestral Excerpts for Conductors (open access)

Orchestral Excerpts for Conductors

"Orchestral Excerpts for Conductors" is a compilation of sixty-five full score excerpts from the orchestral repertory arranged for string quartet and piano. The purpose of this collection is to provide conducting students with a pedagogical resource for learning how to handle technically challenging excerpts in orchestral music. This dissertation serves as a plan for the final publication of the excerpts book; while it includes the full score excerpts, it does not include the arrangements for string quartet and piano.
Date: May 2018
Creator: Morel, Jessica
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Exploration of Information Sharing Structures within Makerspaces: A Mixed Methods Case Study of Dallas Makerspace and Its Users (open access)

Exploration of Information Sharing Structures within Makerspaces: A Mixed Methods Case Study of Dallas Makerspace and Its Users

Makerspaces are a popular, new concept being implemented in public, academic, and school libraries, and as stand-alone spaces. The literature reflects the newness of the topic with a limited number of articles and studies and even less about the users of makerspaces themselves. This study explored information sharing behaviors in the Dallas Makerspace as an informal learning environment and described their preferred method of information transfer from one member to another. It employed a mixed methods methodology using surveys, interviews and observations. The study identified how the rules and policies in place at the makerspace influence the information seeking process and how the Dallas Makerspace exchanges information effectively. Dallas Makerspace is one of the largest non-profit work groups in its size, and this research study answers how information is exchanged in an informal environment.
Date: May 2018
Creator: Hadidi, Rachel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Revised Stress-Related Growth Scale: Improving the Measurement of Posttraumatic Growth (open access)

The Revised Stress-Related Growth Scale: Improving the Measurement of Posttraumatic Growth

This study evaluated a revised version of the Stress-Related Growth Scale (SRGS-R). The SRGS-R has two major differences from the Stress-Related Growth Scale (SRGS). It uses neutral wording of items instead of the original positively worded items, and it uses positive and negative scaling choices. This study included participants (N = 764) recruited through Amazon MTurk. There were three versions of the SRGS-R tested - the SRGS with neutral wording of items only (SRGS-R-N), the SRGS with positive and negative scaling only (SRGS-R-S), and the SRGS-R, with both changes. We randomly assigned participants to complete one of four PTG measures - the SRGS-R-N, SRGS-R-S, SRGS-R, or the Posttraumatic Growth Inventory (PTGI). The PTGI elicited the largest levels of reported PTG, while the SRGS-R elicited the smallest levels. The two modified versions displayed scores between the SRGS-R and the PTGI in the small and moderate growth groups. In the current study the SRGS-R was negatively related to PTSD symptoms, depression, anxiety (negative, but not statistically significant), global distress (negative, but not statistically significant), and avoidance-focused coping (negative, but not statistically significant), and positively related to positive well-being, quality of life, problem-focused coping, and emotion-focused coping. In comparison, the PTGI was unrelated …
Date: May 2018
Creator: Bedford, Lee
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Optimization of In Vitro Mammalian Blastocyst Development: Assessment of Culture Conditions, Ovarian Stimulation and Experimental Micro-Manipulation (open access)

Optimization of In Vitro Mammalian Blastocyst Development: Assessment of Culture Conditions, Ovarian Stimulation and Experimental Micro-Manipulation

Factors currently at the forefront of human in vitro fertilization (IVF) that collectively influence treatment success in the form of blastocysts development were investigated during early mammalian embryology with concentration on infertile patients presenting with diminished ovarian reserve or preliminary ovarian failure. A novel experimental technique, Graft Transplant-Embryonic Stem Cells (GT-ESC) was introduced in the mouse model, as the first inclusive approach for embryo selection in IVF treatments resulting in successful graft integration of sibling cells, stage-dependent (day 4) blastocysts. E-Cadherin-catenin bonds play an integral role in trophectoderm cell viability and calcium removal, inducing disruption of cell-to-cell bonds at the blastocyst stage was detrimental to continued blastocyst development. One of the leading methods for embryo selection for uterine transfer in human IVF is application of pre-implantation genetic screening (PGS) methods such as next generation sequencing (NGS). Female patients <35 y do not benefit from this treatment when outcome is measured by presence of fetal heart beats at 10 weeks of gestation. Patients 35-37 y benefit from PGS with no significant difference of outcome based on form of PGS method utilized. Therefore, small nucleotide polymorphism array (snp-array) or targeted-NGS should be selected for this age range to lessen the financial burden …
Date: May 2018
Creator: Sadruddin, Sheela
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Exploring Perceptions of Brand Loyalty and Consumer Identity among Millennial Males Living in Central Ohio (open access)

Exploring Perceptions of Brand Loyalty and Consumer Identity among Millennial Males Living in Central Ohio

Brand loyalty is a common theme throughout consumer and market research, yet it has not been a major topic among anthropologists. The research presented here is an anthropological exploration of the social and cultural influences on how a unique demographic - millennial males - view their own loyalty to brands. Through the use of qualitative interviews and online surveys, participants provided insight in to how they viewed their favorite brands and how those brands fit in to their lives. After analysis was done on these interviews a number of themes and degrees of attachment were identified and discussed.
Date: May 2018
Creator: Oates, Blake A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
An Investlarks and Hearts: Circadian Mismatch and Effort Intensity (open access)

An Investlarks and Hearts: Circadian Mismatch and Effort Intensity

My experiment concerned the influence of chronobiological (circadian) rhythm on fatigue, effort, and cardiovascular (CV) response. It evaluated responses of morning people (Larks) presented an easy or difficult recognition memory task at a time congruent or incongruent with their rhythm. Based on an extension of a conceptual analysis of fatigue influence, my central prediction was that circadian rhythm would combine interactionally with task difficulty to determine effort and associated CV responses. Specifically, effort and associated CV responses were expected to be (1) positively correspondent to task difficulty in the morning (stronger where difficulty is high), but (2) negatively correspondent to difficulty in the evening (stronger where difficulty is low). Preliminary results showed concerning gender effects on difficulty appraisal of the task, thus we examined women and men's data separately. CV findings for women were broadly, but not completely, consistent with predictions. Analyses revealed no group differences in CV response for Lark men.
Date: May 2018
Creator: Carbajal, Ivan
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Nature's Patrons: Private Sector Engagement and Powerful Environmentalisms (open access)

Nature's Patrons: Private Sector Engagement and Powerful Environmentalisms

In this dissertation, I examine the role of private sector engagement in environmental governance. The relationship between mainstream environmentalism and the private sector has moved from one of general hostility to one of constructive engagement in recent times. As a result, the traditional distinctions between environmental non-governmental organizations and private corporations have become blurred, making way for public-private hybrids, facilitated by frameworks of philanthropy, sponsorship, and corporate social responsibility. Connected to these broader reconfigurations in environmental governance are simultaneous alterations in the normative framework of mainstream environmentalism. Ideologically, environmental policy and neoliberalism are now intertwined, entangling assumptions about nature and culture, and reflected in the popularization of environmental protection mechanisms that are deeply embedded in the values of the market economy. Analyzing particular examples of such engagements, and informed by Gramscian theory, I analyze the connections between rising corporate presence in mainstream environmentalism and broader normative and practical change, focusing, in particular, on the frameworks of ecomodernism and the Green Economy. I argue that contemporary private sector engagement in environmentalism leads to the support, production and construction of powerful environmentalisms: environmental ideologies and practices that gain power from, not in spite of, prevailing dominant interests. As such, these powerful environmentalisms …
Date: May 2018
Creator: Ward, Nora Catherine
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Framing the DREAM Act: An Analysis of Congressional Speeches (open access)

Framing the DREAM Act: An Analysis of Congressional Speeches

Initially proposed in 2001, the Development, Relief, and Education for Alien Minors Act (DREAM Act) continues to be relevant after nearly 20 years of debate. The year 2010 was significant because there seemed to be some possibility of passage. This study investigated the ways in which the DREAM Act discourse was framed that year by supporters and opponents. Selected Congressional speeches of three supporters and three opponents were analyzed using the approach to frame analysis developed by Schön and Rein. Accordingly, attention went to each individual's metacultural frame (i.e., culturally shared beliefs), policy frame (i.e., identification of problem and presentation of possible solution), and rhetorical frame (i.e., means of persuading the audience). Attention also went to the shared framing among supporters and the shared framing among opponents as well as differences in framing across the two groups. Although speakers varied in framing the issue, there were commonalities within groups and contrasts between groups. For supporters, the metacultural frame emphasized equity/equal opportunity, fairness, and rule of law; for opponents, the metacultural frame stressed rule of law, patriotism, and national security. For supporters, the policy frame underscored unfairness as the problem and the DREAM Act as the solution; for opponents, the policy …
Date: May 2018
Creator: Koo, Yilmin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Perceptions about Student Diversity and Equity in Early Childhood Science Education: A Teacher Preparation Study (open access)

Perceptions about Student Diversity and Equity in Early Childhood Science Education: A Teacher Preparation Study

Using a mixed-methods approach, the current study examined the relationship between early childhood preservice teachers' cultural awareness and their self-efficacy in equitable science education. It further aimed to determine if the relationship between these two constructs was moderated by their race/ethnicity or the number of languages they speak. Finally, it sought to identify preservice teachers' understanding of equity in science education, as well as how they planned to incorporate the equity concept into their future science teaching practices for diverse learners in early childhood classrooms. Data for this study were drawn from 380 preservice teachers who self-enrolled in a science methods course as part of a teacher preparation program. To measure the preservice teachers' cultural awareness and self-efficacy in equitable science education, two Likert-scale instruments, Cultural Diversity Awareness Inventory (CDAI) and Self-Efficacy Beliefs about Equitable Science Teaching and Learning (SEBEST), were employed. Qualitative data were collected by administering six open-ended questions. For quantitative results, statistically significant findings indicated that when the participants were more aware of creating a multicultural environment and instruction and/or when they were less biased and were more sensitive/knowledgeable about diversity of students and families, their expectations about science learning of students from diverse backgrounds would be …
Date: May 2018
Creator: Lee, Eun Young
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Why Dance? The Effects of a Group Dance Period on Social Attending, On-Task Behavior, Affect, Stereotypical Behavior, and Disruptive Behavior of Clients of an Autism Treatment Program (open access)

Why Dance? The Effects of a Group Dance Period on Social Attending, On-Task Behavior, Affect, Stereotypical Behavior, and Disruptive Behavior of Clients of an Autism Treatment Program

Dance is an enjoyable activity that children can engage in across the lifespan. Many children with autism have limited leisure activity, such as dance, and also have challenges in terms of overall health related to physical activity. Previous research suggests that there are both immediate and prolonged benefits of exercise. The purpose of the present study was to evaluate the effects of a group dance period on on-task behavior, social attending, affect, stereotypic behavior, and disruptive behavior of three girls diagnosed with autism. The experimenter employed a reversal to evaluate the effects of a "dance party" on a range of behaviors over time. During dance activities, staff and children danced as a group and were observed before and after the dance period. During baseline there was no dance party. While no differences were found across measures, the children did have high levels of favorable affect during the dance party. The results are discussed in the context of previous literature and directions for future studies.
Date: May 2018
Creator: Allen, Emerald Elizabeth
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Estimating Postmortem Interval Using VNIR Spectroscopy on Human Cortical Bone (open access)

Estimating Postmortem Interval Using VNIR Spectroscopy on Human Cortical Bone

Postmortem interval (PMI) estimation is a necessary but often difficult task that must completed during a death investigation. The level of difficulty rises as time since death increases, especially with the case of skeletonized remains (long PMI). While challenging, a reliable PMI estimate may be of great importance for investigative direction and cost-savings (e.g. suspect identification, tailoring missing persons searches, non-forensic remains exclusion). Long PMI can be estimated by assessing changes in the organic content of bone (i.e. collagen), which degrades and is lost as the PMI lengthens. Visible-near infrared (VNIR) spectroscopy is one method that can be used for analyzing organic constituents, including proteins, in solid specimens. A 2013 preliminary investigation using a limited number of human cortical bone samples suggested that VNIR spectroscopy could provide a fast, reliable technique for assessing PMI in human skeletal remains. Clear separation was noted between "forensic" and "archaeological" specimen spectra within the near-infrared (NIR) bands. The goal of this research was to develop reliable multivariate classification models that could assign skeletal remains to appropriate PMI classes (e.g. "forensic" and "non-forensic"), based on NIR spectra collected from human cortical bone. Working with a large set of cortical samples (n=341), absorbance spectra were collected …
Date: May 2018
Creator: Servello, John A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Changes in Student Borrowing at Private Not-for-Profit Four-Year Institutions in the United States (open access)

Changes in Student Borrowing at Private Not-for-Profit Four-Year Institutions in the United States

Trends in tuition and financial aid policy have increased the number of students who borrow for higher education and the aggregate debt students acquire. Most research on student borrowing over the years has analyzed the effects of borrowing and the prospects of indebtedness on individual students' choices and persistence. However, dynamics at the institutional level such as the need to ensure a stable flow of resources may accelerate or slow down student borrowing. Drawing on resource dependence theory, this study examined changes in student borrowing at private not for profit four year institutions in the US to identify trends and implications. A fixed effects regression analysis was applied to panel data from the Delta Cost project and the National Association of College and University Business Officers. Analytical focus was on the financial and enrollment characteristics of private not for profit four-year institutions, the relationship between these characteristics and student borrowing, and whether these relationships are stable or change over time. Findings revealed that the financial and enrollment characteristics of private not for profit institutions during the study period were characterized by gradual variation. The results also revealed that most of the financial characteristics were predictive of student borrowing and that …
Date: May 2018
Creator: Namalefe, Susan A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Effects of Differential Outcomes on Audio-Visual Conditional Discriminations in Children with ASD (open access)

The Effects of Differential Outcomes on Audio-Visual Conditional Discriminations in Children with ASD

The differential outcomes effect (DOE) refers to an observed increase in rates of acquisition of simple or conditional relations when the contingencies of reinforcement arrange for reinforcers to be uniquely correlated with a particular stimulus or response relative to conditions where the reinforcers are not uniquely correlated with either stimulus or response. This effect has been robustly documented in the literature with nonhuman subjects. This study asked whether the DOE would be observed with children with autism spectrum disorder (ASD) learning audio-visual conditional relations. Two participants learned two sets of 3 audio-visual conditional relations. For one set, the training conditions arranged for each of the three conditional relations to be uniquely correlated with a particular reinforcing stimulus (the DO condition). For the second set, the training conditions arranged for the same reinforcer to be used for all three audio-visual conditional relations (the NDO condition). Early results show that audio-visual conditional relations were acquired faster under the DO condition relative to the NDO outcomes condition (accuracy in DO condition was 30.8% higher on average than in NDO condition). These data suggest that differential outcomes should be more thoroughly investigated with children with diagnoses of ASD.
Date: May 2018
Creator: Wiist, Catherine E. C.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Feeling Fat and Depressed: Positive Dimensions of Self-Concept Lessen that Relationship for College Men (open access)

Feeling Fat and Depressed: Positive Dimensions of Self-Concept Lessen that Relationship for College Men

The purpose of the current study was to examine if positive family, social, and/or academic dimensions of SC weaken (i.e., moderate) the direct relationship between physical SC (i.e., a person's evaluation of their physique, adiposity, and weight) and depressive symptoms in a sample of adult men. A convenience sample of 239 college men completed self-report measures including the Tennessee Self-Concept Scale-2 (TSCS-2) and Symptom Checklist-90 Revised. Hierarchical regressions revealed that family and social SC were significant moderators of the relationship between physical SC and depressive symptoms, suggesting how men see themselves in their family and social systems affects the aforementioned relationship. Academic SC, however, was not a significant moderator; it was negatively related to depressive symptoms no matter how men felt about their physical selves. Our findings suggest that feeling positively about one's relationships may protect men with poor physical SC from experiencing symptoms of depression at the rates or intensity of their similarly body dissatisfied peers who do not report positive family or social SC. An additional simultaneous regression assessed the contribution of various dimensions of SC to the prediction of depressive symptoms, physical (7.76%), social (8.02%) and academic (6.62%) self-concept accounted for significant amount of variance in symptoms …
Date: May 2018
Creator: McGregor, Carlie C.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Effects of Bodily Arousal on Desire to Drink Alcohol among Trauma-Exposed Emerging Adult College Students (open access)

Effects of Bodily Arousal on Desire to Drink Alcohol among Trauma-Exposed Emerging Adult College Students

Alcohol consumption on college campuses is a major public health concern, particularly among emerging adults. Extant literature has identified trauma exposure and posttraumatic stress as robust risk factors for problematic alcohol use. However, the mechanisms underlying this association are less well-studied. Research indicates that bodily arousal is a fundamental feature of trauma exposure and posits that internal stimuli (e.g., heart pounding) at the time of trauma may manifest into conditioned cues that can trigger posttraumatic responding and related symptomatology, including alcohol use. However, past work supporting these assertions have used paradigms purposefully designed to evoke memories of the trauma, making it difficult to conclude whether the subsequent alcohol craving was due more to the explicit memory cue or the associated bodily arousal. The current study examined whether an implicit, trauma-relevant cue of bodily arousal (via hyperventilation) – independent of any explicit memory cue – would elicit increased desire to drink among 80 (Mage = 20.34; 63.8% female) trauma-exposed, emerging adult students. Results found no statistically significant difference in change in alcohol craving between the hyperventilation and control tasks. However, exploratory analyses indicated that trauma type (i.e., interpersonal/non-interpersonal) may moderate this relationship; more specifically, individuals reporting interpersonal trauma as their most …
Date: May 2018
Creator: Kearns, Nathan T
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Identification and Participation of Latino Students in Advanced Mathematics Courses (open access)

The Identification and Participation of Latino Students in Advanced Mathematics Courses

Using a phenomenological approach, this qualitative study examined the perspectives of Latino parents and their involvement in the decision of their child to enroll in an advanced mathematics course in sixth grade. Since enrollment in Algebra I in high school is said to be a strong predictor of college attainment and with the growing number of Latino students across the nation, this study has the potential to help district and campus leaders establish whole-school systems for communicating with Latino parents to encourage their children to enroll in advanced mathematics courses at earlier grades. Participants in this study included four sixth-grade students enrolled in an advanced mathematics course, four enrolled in regular mathematics, their mother or father, two mathematics teachers, a school counselor, and two district administrators. Data analyzed included audio recordings of semi-structured interviews of each of the participants. The findings suggested that the district has proactively developed a systematic process of creating that includes six data points to create a student profile of students that will do well in advanced mathematics. This process is helping the district close the gap between total Latino school enrollment and the enrollment of Latino students in advanced mathematics. The findings also suggested that …
Date: May 2018
Creator: Blanchard, Myrna Elizabeth
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Computational Simulations of Cancer and Disease-Related Enzymatic Systems Using Molecular Dynamics and Combined Quantum Methods (open access)

Computational Simulations of Cancer and Disease-Related Enzymatic Systems Using Molecular Dynamics and Combined Quantum Methods

This work discusses applications of computational simulations to enzymatic systems with a particular focus on the effects of various small perturbations on cancer and disease-related systems. First, we cover the development of carbohydrate-based PET imaging ligands for Galectin-3, which is a protein overexpressed in pancreatic cancer tumors. We uncover several structural features for the ligands that can be used to improve their binding and efficacy. Second, we discuss the AlkB family of enzymes. AlkB is the E. coli DNA repair protein for alkylation damage, and has human homologues with slightly different functions and substrates. Each has a conserved active site with a catalytic iron and a coordinating His...His...Asp triad. We have applied molecular dynamics (MD) to investigate the effect of a novel single nucleotide polymorphism for AlkBH7, which is correlated with prostate cancer and has an unknown function. We show that the mutation leads to active site distortion, which has been confirmed by experiments. Thirdly, we investigate the unfolding of hen egg white lysozyme in 90% ethanol solution and low pH, to show the initial steps of unfolding from a native-like state to the disease-associated beta-sheet structure. We compare to mass spectrometry experiments and also show differing pathways based on …
Date: May 2018
Creator: Walker, Alice Rachel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Population Genetic Structure of Quadrula aurea (Bivalvia: Unionidae), A Threatened Freshwater Mussel in Central Texas (open access)

The Population Genetic Structure of Quadrula aurea (Bivalvia: Unionidae), A Threatened Freshwater Mussel in Central Texas

The anthropogenic alteration of riverine ecosystems has led to declines in the abundance and diversity of freshwater mussels (Bivalvia: Unionoida) worldwide. Central Texas is home to a diverse freshwater mussel fauna including three candidates for federal listing under the Endangered Species Act. Surveys conducted over the last few decades suggest many of the endemic freshwater mussel species in Texas exist in small isolated populations that may be vulnerable to the deleterious effects of genetic diversity loss. Microsatellite primers from two closely related species were used to identify a set of genetic markers that functioned in the Golden Orb (Quadrula aurea). Microsatellite markers were then applied to document the population genetic structure of Q. aurea within and among three connected river drainages in southeastern Texas. Gene flow within existing Q. aurea populations appears high indicating little potential for genetic issues stemming from isolation and inbreeding. Two weakly divergent admixed populations were identified occupying the San Antonio and Guadalupe/San Marcos rivers. Population genetic structure was related to river basin affiliation, but results for environmental factors were unresolved. Current effective population size estimates are large for the Guadalupe/San Marcos drainage and moderately large for the San Antonio drainage and there is no clear …
Date: May 2018
Creator: Mabe, Jeffrey A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Three Essays on Information Security Risk Management (open access)

Three Essays on Information Security Risk Management

Today's environment is filled with the proliferation of cyber-attacks that result in losses for organizations and individuals. Hackers often use compromised websites to distribute malware, making it difficult for individuals to detect. The impact of clicking through a link on the Internet that is malware infected can result in consequences such as private information theft and identity theft. Hackers are also known to perpetrate cyber-attacks that result in organizational security breaches that adversely affect organizations' finances, reputation, and market value. Risk management approaches for minimizing and recovering from cyber-attack losses and preventing further cyber-attacks are gaining more importance. Many studies exist that have increased our understanding of how individuals and organizations are motivated to reduce or avoid the risks of security breaches and cyber-attacks using safeguard mechanisms. The safeguards are sometimes technical in nature, such as intrusion detection software and anti-virus software. Other times, the safeguards are procedural in nature such as security policy adherence and security awareness and training. Many of these safeguards fall under the risk mitigation and risk avoidance aspects of risk management, and do not address other aspects of risk management, such as risk transfer. Researchers have argued that technological approaches to security risks are rarely …
Date: May 2018
Creator: Ogbanufe, Obiageli
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Public Market Trade Areas:  Local Goods, Farmers, and Community in the U.S. Southwest Region, 1996-2016 (open access)

Public Market Trade Areas: Local Goods, Farmers, and Community in the U.S. Southwest Region, 1996-2016

The number of public markets in the United States increased from more than 300 in the 1970s to more than 8,600 by 2016. This increase in markets is related to changes in food production, localism and the local food systems movement, socioeconomic changes, cultural changes, and perceptions of embeddedness. Research on the underlying conditions for the success of public markets is scant in the United States, and especially in the USDA Southwest Region. This study provides analysis of public market locations as compared with non-market locations by drive-time trade areas during a 20-year period, 1996 and 2016, to gain further insights into factors leading to their success. The results from logit regression analyses and simulations of socioeconomic, college-town status, and climate-grid classifications find an increased likelihood of public markets with population, education, college town status, and some climate-grid locations. Median income, surprisingly, has an inverse relationship with public market success. Qualitative data and a literature review point to three types of embeddedness that motivate customers to attend public markets. This study concludes that "local nontradable consumer goods" tied to place are offered at these "nontradable consumption amenities." These amenities are "third places" that promote social interaction and become important places …
Date: May 2018
Creator: Oppenheim, Vicki Ann
Object Type: Thesis or Dissertation
System: The UNT Digital Library