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Are Streams Protected? Outcomes of Environmental Regulation

Description: Urban areas experience the loss of natural stream channels through conversion to artificial conveyances. This process tends to target headwater and other low order streams. The purpose of this study is to determine the patterns of stream loss in Denton, Texas, and explore the regulatory structure that manages these streams. Historic and current maps and stream data are used to map Denton's streams and categorize them according to their vertical connectivity as: 1) "intact", streams that are open to the atmosphere and connect to groundwater; 2) "concrete", channelized streams open to the atmosphere but cut off from groundwater; and 3) "buried", streams disconnected from the atmosphere and groundwater. A review of federal, state, and local regulatory codes and interviews with local government officials and other stakeholders elucidates stream management in Denton. Results from these analyses reveal high rates of stream loss in the urban center with low rates overall. The federal Clean Water Act and the local Environmentally Sensitive Areas code serve as the primary protective measures for natural streams. These regulations discourage stream impacts through expensive and complex permitting requirements. However the policies allow minor impacts which may cause cumulative effects. This study aims to inform future policy-making decisions and contribute to the knowledge of the environmental regulation of streams.
Date: August 2017
Creator: Rowen, Zachary

Predictors of Postsecondary Success: An Analysis of First Year College Remediation

Description: This study was a quantitative multiple regression investigation into the relationships between campus factors of high school students graduating in 2013 who immediately enrolled in first-year college freshman level remedial coursework at a large, Central Texas two-year postsecondary institution. The goal of this study was to determine which high school campus-level factors predicted enrollment into college remedial education coursework. The dependent variable was a continuous variable representing the percentage of students from Texas public high school campuses enrolled into at least one student credit hour of remedial education during their first semester as a first-year college student. Eight high school campus-level independent variables were included in the regression model at the campus-level: at risk percentage, economically disadvantaged percentage, limited English proficient percentage, advanced course/dual-enrollment percentage, college ready math percentage, college ready English percentage, ACT average, and SAT average. Pearson correlations and linear regression results were examined and interpreted to determine the level of relationship between the eight selected variables and first-year college student remedial coursework. The multiple regression model successfully explained 26.3% (F(8,286) = 12.74. p < 0.05, r2 = 0.263) of the variance between first-year college students enrolled into remedial coursework at a large, Central Texas two-year postsecondary institution and the campus-level variables from high schools from which they graduated and indicated campus-level economic disadvantaged percentage and campus-level SAT average to be statistically significant at the p < 0.05 level.
Date: August 2017
Creator: Baker, Emmett Andrew

Effect of Surface Treatment on the Performance of CARALL, Carbon Fiber Reinforced Aluminum Joints

Description: Fiber-metal laminates (FML) are the advanced materials that are developed to improve the high performance of lightweight structures that are rapidly becoming a superior substitute for metal structures. The reasons behind their emerging usage are the mechanical properties without a compromise in weight other than the traditional metals. The bond remains a concern. This thesis reviews the effect of pre-treatments, say heat, P2 etch and laser treatments on the substrate which modifies the surface composition/roughness to impact the bond strength. The constituents that make up the FMLs in our present study are the Aluminum 2024 alloy as the substrate and the carbon fiber prepregs are the fibers. These composite samples are manufactured in a compression molding process after each pre-treatment and are then subjected to different tests to investigate its properties in tension, compression, flexural and lap shear strength. The results indicate that heat treatment adversely affects properties of the metal and the joint while laser treatments provide the best bond and joint strength.
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Date: August 2017
Creator: Bandi, Raghava

A Mixed Methods Approach to Exploring Social Support and Resilience in Coping with Stigma and Psychological Distress among HIV-Positive Adults

Description: Since its emergence in the U.S., HIV has been a stigmatized illness. People living with HIV (PLH) are a minority and prone to psychological distress and poor mental health outcomes due to HIV-related stigma. PLH who identify with another minority group in addition to being HIV-positive (e.g., gay, African-American) experience multiple forms of oppression or layered stigma. Affirmative social support and resilience are negatively associated with HIV-stigma and are important coping resources for PLH. We used an explanatory sequential mixed methods design study involving a quantitative survey phase and a qualitative interview phase. We explored whether social support and resilience (Positive Psychological Resources) mediate or moderate the relationship between HIV Stigma and Psychological Distress among HIV-positive adults using partial least squares (PLS) path modeling and multiple regressions. Via PLS, we found Positive Psychological Resources partially mediated the relationship between HIV Stigma and Psychological Distress: the path between HIV Stigma and Psychological distress reduced (from t = 5.49, p = .000 to t = 2.39, p = .000) but remained statistically significant. Similarly, via regression, the Sobel test was significant (Sobel = .26, SE = .07, z = 3.63, p = .000). However, moderation was not found (HIV Stigma x Positive Psychological Resources β = .05, t = .66, p = .508). Overall, our quantitative survey and qualitative interview data were consistent. We anticipate that our findings will inform strengths-based therapeutic interventions to mitigate stress and stigma among PLH.
Date: August 2017
Creator: Fritz, Sarah-mee

Educational Uplift along the US-Mexico Border: How Students, Families, and Educators Cultivate a College-Going Culture in Contested Terrain

Description: Using critical race theory and LatCrit as conceptual frameworks, I conducted a qualitative instrumental case study of a cadre of self-identified Mexican-American and Hispanic college students who bring college knowledge, goodwill, and aid to their border town communities. The purpose of this study was to explore how college knowledge and other forms of academic capital are transmitted and co-constructed in the contested terrain of the borderlands. Primary data sources included semi-structured interviews, participant and non-participant observation, and personal artifacts (e.g. newspaper articles, college admissions essays, social media, etc.) collected from 17 full-time undergraduate student participants, 11 males and 6 females, ranging from 19 to 22 years old, who were active members of the Gates Millennium Scholars Program. Supplemental data sources included semi-structured interviews with 23 family members and 9 educators identified by student participants, as well as a review of public records regarding student participant's border town communities (e.g. newspaper articles, census data, educational statistics, etc.). Findings detail how this group of college students manages the 'scholar' distinction in their hometown and utilizes distinct methods to promote academic capital formation. Specifically, this study delineates the following four types of scholars: (1) pioneers, (2) guardians, (3) ambassadors, and (4) advocates. Ultimately, this research highlights the importance of college students' ingenuity in response to enduring system inequality in higher education, particularly along the U.S.-Mexico border, with implications for research theory, policy, and practice.
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Date: August 2017
Creator: Sanchez, Nydia C

Social Support as a Moderator of Racial/Ethnic Differences in Subclinical Atherosclerosis: The North Texas Heart Study

Description: This study examined racial/ethnic differences in pre-clinical disease, social support, and tested whether social support was a moderator of racial/ethnic differences in subclinical atherosclerosis. Participants were NHWs, NHBs, and Latinos (n = 283) from the baseline and cross-sectional sample of the North Texas Heart Study. Results from unadjusted models showed no significant racial/ethnic differences for common or bifurcation intima-media thickness (cIMT). However, unadjusted models for cIMT showed a main effect for race/ethnicity F(2, 229) = 3.12, p = .046, partial η2 = .027, with Latinos demonstrating significantly greater internal cIMT compared to NHB but not NHWs. In minimally adjusted models, there was a main effect for race/ethnicity, F(2, 227) = 3.10, p = .047, partial η2 = .027, with significantly greater internal cIMT in Latinos compared to NHBs but not NHWs. In fully adjusted models, racial/ethnic differences in cIMT were attenuated. Contrary to study hypotheses, no racial/ethnic differences in social support were found and social support was not a moderator of racial/ethnic differences in subclinical disease. In the North Texas Heart Study, few racial/ethnic differences emerged, with fully adjusted risk factor models accounting for these differences.
Date: August 2017
Creator: Garcia, James Jonathan

Laser Additive Manufacturing of Magnetic Materials

Description: A matrix of variably processed Fe-30at%Ni was deposited with variations in laser travel speeds as well and laser powers. A complete shift in phase stability occurred as a function of varying laser travel speed. At slow travel speeds, the microstructure was dominated by a columnar fcc phase. Intermediate travel speeds yielded a mixed microstructure comprised of both the columnar fcc and a martensite-like bcc phase. At the fastest travel speed, the microstructure was dominated by the bcc phase. This shift in phase stability subsequently affected the magnetic properties, specifically saturation magnetization. Ni-Fe-Mo and Ni-Fe-V permalloys were deposited from an elemental blend of powders as well. Both systems exhibited featureless microstructures dominated by an fcc phase. Magnetic measurements yielded saturation magnetizations on par with conventionally processed permalloys, however coercivities were significantly larger; this difference is attributed to microstructural defects that occur during the additive manufacturing process.
Date: August 2017
Creator: Mikler, Calvin

It's All Coming Back to You: 1980s Retro Film Culture and the Masculinity of Cult

Description: The 1980s is a formative decade in American history. America sought to reestablish itself as a global power and to reassert the dominant ideology of white, patriarchal capitalism. Likewise, media producers in the 1980s sought to reassert the dominance of the white, male, muscled body in filmic representations. The identity politics of the 1980s and the depictions of the white, muscled body once prominent in the 1980s have been the site of conservative nostalgia for a young, male-dominated, cult audience that is a subset of a larger cultural trend known as retro film culture. This thesis provides historical context behind the populist 1980s B-action films from Cannon Group, Inc that celebrate violent masculinity in filmic representations with white, male action heroes. Equally important is the revival of VHS collecting and how this 1980s-inspired subculture reinforces white, patriarchal capitalism through the cult films they valorize and their capitalistic trading practices despite their claims of oppositionality against mainstream taste and Hollywood films. Lastly, this thesis reveals how a new cycle of contemporary films primarily produced outside of Hollywood reasserts and celebrates the dominance of the white, male, muscled body in filmic representations despite a postmodern and hyperconscious exterior. Overall, I argue how these areas of nostalgia are distinct, yet not unrelated, because they reassert white, patriarchal capitalism through the revival of conservative nostalgia for the 1980s.
Date: August 2017
Creator: Collins, Ryan William

Investigating Human Gut Microbiome in Obesity with Machine Learning Methods

Description: Obesity is a common disease among all ages that has threatened human health and has become a global concern. Gut microbiota can affect human metabolism and thus may modulate obesity. Certain mixes of gut microbiota can protect the host to be healthy or predispose the host to obesity. Modern next-generation sequencing technique allows accessing huge amount of genetic information underlying microbiota and thus provides new insights into the functionality of these micro-organisms and their interactions with the host. Multiple previous studies have demonstrated that the microbiome might contribute to obesity by increasing dietary energy harvest, promoting fat deposition and triggering systemic inflammation. However, these researches are either based on lab cultivation studies or basic statistical analysis. In order to further explore how gut microbiota affect obesity, this thesis utilize a series of machine learning methods to analyze large amount of metagenomics data from human gut microbiome. The publicly available HMP (Human Microbiome Project) metagenomic sequencing data, contain microbiome data for healthy adults, including overweight and obese individuals, were used for this study. HMP gut data were organized based on two different feature definitions: taxonomic information and metabolic reconstruction information. Several widely used classification algorithms: namely Naive Bayes, Random Forest, SVM and elastic net logistic regression were applied to predict healthy or obese status of the subjects based on the cross-validation accuracy. Furthermore, the corresponding feature selection algorithms were used to identify signature features in each dataset that lead to the differences between healthy and obese samples. The results showed that these algorithms perform poorly on taxonomic data than metabolic pathway data though lots of selected taxa are still supported by literature. Among all the combinations between different algorithms and data, elastic net logistic regression has the best cross-validation performance and thus becomes the best model. In this model, several important ...
Date: August 2017
Creator: Zhong, Yuqing

Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics using Practical Enhanced Surfaces

Description: The objective of this research was to investigate the performance of two-phase spray cooling with HFC-134a and HFO-1234yf refrigerants using practical enhanced heat transfer surfaces. Results of the study were expected to provide a quantitative spray cooling performance comparison with working fluids representing the current and next-generation mobile air conditioning refrigerants, and demonstrate the feasibility of this approach as an alternative active cooling technology for the thermal management of high heat flux power electronics (i.e., IGBTs) in electric-drive vehicles. Potential benefits of two-phase spray cooling include achieving more efficient and reliable operation, as well as compact and lightweight system design that would lead to cost reduction. The experimental work involved testing of four different enhanced boiling surfaces in comparison to a plain reference surface, using a commercial pressure-atomizing spray nozzle at a range of liquid flow rates for each refrigerant to determine the spray cooling performance with respect to heat transfer coefficient (HTC) and critical heat flux (CHF). The heater surfaces were prepared using dual-stage electroplating, brush coating, sanding, and particle blasting, all featuring "practical" room temperature processes that do not require specialized equipment. Based on the obtained results, HFC-134a provided a better heat transfer performance through higher HTC and CHF values compared to HFO-1234yf at all tested surfaces and flow rates. While majority of the tested surfaces provided comparable HTC and modestly higher CHF values compared to the reference surface, one of the enhanced surfaces offered significant heat transfer enhancement.
Date: August 2017
Creator: Altalidi, Sulaiman Saleh

Crystallographic Complex Reflection Groups and the Braid Conjecture

Description: Crystallographic complex reflection groups are generated by reflections about affine hyperplanes in complex space and stabilize a full rank lattice. These analogs of affine Weyl groups have infinite order and were classified by V.L. Popov in 1982. The classical Braid theorem (first established by E. Artin and E. Brieskorn) asserts that the Artin group of a reflection group (finite or affine Weyl) gives the fundamental group of regular orbits. In other words, the fundamental group of the space with reflecting hyperplanes removed has a presentation mimicking that of the Coxeter presentation; one need only remove relations giving generators finite order. N.V Dung used a semi-cell construction to prove the Braid theorem for affine Weyl groups. Malle conjectured that the Braid theorem holds for all crystallographic complex reflection groups after constructing Coxeter-like reflection presentations. We show how to extend Dung's ideas to crystallographic complex reflection groups and then extend the Braid theorem to some groups in the infinite family [G(r,p,n)]. The proof requires a new classification of crystallographic groups in the infinite family that fail the Steinberg theorem.
Date: August 2017
Creator: Puente, Philip C

Using Possible Selves to Examine the Impact of Internalized Stigma of Mental Illness on the Career Development of College Students with Hidden Disability

Description: The purpose of the study was to examine the impact of internalized stigma of mental illness on the career development of college students with hidden disabilities. The availability of research investigating career variables within this population is limited and is primarily focused within the vocational rehabilitation arena. Therefore, one of the goals of the current study was to link separate bodies of literature on college students with disabilities, career development, and internalized stigma of mental illness. The second goal was to examine the interaction of internalized stigma of mental illness between career decision self-efficacy and career exploration on the perceived likelihood of achieving hoped for occupational possible selves (OPS). The study included college students with hidden disabilities and investigated variables related to mental illness and career. Participants were administered a background information questionnaire, the Career Decision Self-Efficacy scale (CDSE-SF), selected subscales of the Career Exploration Survey (CES), and the Internalized Stigma of Mental Illness scale (ISMI). Contrary to hypotheses, career decision making self-efficacy, career self-exploration, and internalized stigma of mental illness did not have a direct effect on the perceived likelihood of achieving hoped for OPS. However, career environment exploration did have a direct and positive association with perceived likelihood of achieving hoped for OPS. Results further indicated internalized stigma of mental illness did not moderate the effect of career decision self-efficacy and career exploration on the perceived likelihood of achieving one's hoped for occupational self. Study implications, limitations, and future directions are discussed.
Date: August 2017
Creator: Campbell, Robyn

Reproduction and Metabolic Responses to Acute and Chronic Hypoxia in Ovoviviparous Blaberid Cockroaches, with a Focus on Blaptica dubia

Description: The major components of the tracheal system of insects are an extension of the exoskeleton, and the size of the exoskeleton is fixed in the adult stage, so any increase in metabolic demand that may accompany reproduction must be met by a relatively unaltered tracheal system that the female set in place at ecdysis, when entering adulthood. Acute hypoxia tends to elicit an increase in ventilation in insects, and here, I observe increased interburst VCO2 release, and a tendency towards a more continuous gas exchange pattern being preferred over discontinuous gas exchange when Blaptica dubia and Eublaberus posticus are exposed to a descending regime of hypoxia. Additionally, higher temperatures appear to increase sensitivity to hypoxia in these species, an expected result because both species, like most ectothermic animals, display a Q10 effect, increasing metabolic rates as temperature increases. The reproductive mode of B. dubia is considered to be lecithotrophic pseudoviviparity (or type A ovoviviparity), and by the time the embryos are born, they have more than doubles in volume from the time of oviposition. This gain is apparent in the wet mass of the embryo, with no change occurring in dry mass. The egg mass that can be attributed to water begins at 39% at oviposition and increased to nearly 82% at hatching. The metabolic rates of females and embryos increase as embryonic development progresses, but bomb calorimetry reveals that energy content of the embryos does not change. It is possible that these embryos gain some nutrition from the mother during embryonic development, but direct evidence remains to be demonstrated. Blaptica dubia and Eublaberus posticusare both blaberid species that display the same reproductive mode, pseudoviviparity, with incubation occurring in a brood sac. Comparisons between the reproductive traits of B. dubia and E. posticus reveal that the two species have similar ...
Date: August 2017
Creator: Mallery, Christopher Sean

The Impact of Observational Learning on Physical Activity Appraisal and Exertion Following Experimental Back Injury and the Role of Pain-Related Fear

Description: Chronic low back pain (CLBP) is one of the most prevalent and disabling health conditions in the US and worldwide. Biomedical explanations of acute injury fail to account for why some individuals experience remission of pain and restoration of physical function while others do not. Pain-related fear, accompanied by elevated appraisals of physical exertion and avoidance of physical activity, has emerged as a central psychosocial risk factor for transition from acute injury to chronic pain and disability. Research has indicated that these pain-related factors may be maintained through observational learning mechanisms. To date, no studies have experimentally examined the role of observational learning and pain-related fear in the context of actual musculoskeletal injury. Accordingly, the present study examined the impact of observational learning and pain-related fear on activity appraisals and exertion following experimentally- induced acute low back injury. Healthy participants' appraisal of standardized movement tasks along with measures of physical exertion were collected prior to and following a procedure designed to induce delayed onset muscle soreness (DOMS) to the lower back. Following induction of DOMS, participants observed a video prime depicting CLBP patients exhibiting either high or low pain behavior during similar standardized movements. In line with hypothesized effects, participants assigned to the high pain behavior prime demonstrated greater elevation in pain and harm appraisals as well as greater decrement in physical exertion. Further in line with hypotheses, significant changes in appraisal and physical performance following the high pain behavior prime were only observed among participants endorsing high pain-related fear during baseline assessment. Discussion of findings addresses potential mechanisms of action as well as study limitations and direction for future research.
Date: August 2017
Creator: Guck, Adam

A Convergence of LDPC Based on Eigenvalues

Description: Low-density parity check (LDPC) codes are very popular among error correction codes because of their high-performance capacity. Numerous investigations have been carried out to analyze the performance and simplify the implementation of LDPC codes. Relatively slow convergence of iterative decoding algorithm affects the performance of LDPC codes. Faster convergence can be achieved by reducing the number of iterations during the decoding process. In this thesis, a new approach for faster convergence is suggested by choosing a systematic parity check matrix that yields lowest Second Smallest Eigenvalue Modulus (SSEM) of its corresponding Laplacian matrix. MATLAB simulations are used to study the impact of eigenvalues on the number of iterations of the LDPC decoder. It is found that for a given (n, k) LDPC code, a parity check matrix with lowest SSEM converges quickly as compared to the parity check matrix with high SSEM. In other words, a densely connected graph that represents the parity check matrix takes more iterations to converge than a sparsely connected graph.
Date: August 2017
Creator: Kharate, Neha Ashok

Fabrication of Photonic Crystal Templates through Holographic Lithography and Study of their Optical and Plasmonic Properties in Aluminium Doped Zinc Oxide

Description: This dissertation focuses on two aspects of integrating near-infrared plasmonics with electronics with the intent of developing the platform for future photonics. The first aspect focuses on fabrication by introducing and developing a simple, single reflective optical element capable of high–throughput, large scale fabrication of micro- and nano-sized structure templates using holographic lithography. This reflective optical element is then utilized to show proof of concept in fabricating three dimensional structures in negative photoresists as well as tuning subwavelength features in two dimensional compound lattices for the fabrication of dimer and trimer antenna templates. The second aspect focuses on the study of aluminum zinc oxide (AZO), which belongs to recently popularized material class of transparent conducting oxides, capable of tunable plasmonic capabilities in the near-IR regime. Holographic lithography is used to pattern an AZO film with a square lattice array that are shown to form standing wave resonances at the interface of the AZO and the substrate. To demonstrate device level integration the final experiment utilizes AZO patterned gratings and measures the variation of diffraction efficiency as a negative bias is applied to change the AZO optical properties. Additionally efforts to understand the behavior of these structures through optical measurements is complemented with finite difference time domain simulations.
Date: August 2017
Creator: George, David Ray

John Playford's "The Division Violin": Improvisation and Variation Practice in English Violin Music of the Seventeenth Century

Description: English publisher John Playford (1623-1686/1687) first published his "The Division Violin: Containing a Collection of Divisions Upon Several Grounds for the Treble-Violin" in 1684. The first edition of this violin collection contains 26 written-out examples of improvisation, serving as a living snapshot of the performance practice of the time. This research is based on the second edition, which Playford had expanded into 30 pieces for the violin, published in 1685. The purpose of this study is to investigate the art of improvisation in England during the late 17th century, focusing on Playford's "The Division Violin." The dissertation first surveys the development of English violin music in the 17th century. Then, the dissertation traces eight selected 16th-century Italian diminution manuals. This will help readers understand the progression of the Italian diminution and improvisation practice in the 16th century and how it relates to the English division of the 17th century. Finally, based on a thorough research of the 17th-century improvisatory style and rhetorical approach, the author of this study provides performance suggestions on "Mr. Farinell's Ground," No. 5 from "The Division Violin."
Date: August 2017
Creator: Chan, Tzu-Ying

A Comprehensive Performance Guide for the Use of Advanced Technology in Euphonium Repertoire with Electronic Media through Analyses of Works by D. Edward Davis, Neal Corwell, and Lucy Pankhurst

Description: Solos for euphonium with electronic media present the unique challenge of incorporating an active, physical involvement in the live accompaniment through sound-altering technology such as guitar pedals or digital processors. Instructions for this solo genre are often vague and demand a general knowledge of how to use non-traditional devices. Due to the lack of information available on newly-composed pieces for this medium, students and professionals easily overlook the artistic merit of electroacoustic music. This dissertation provides a comprehensive performance guide that aids in the set-up and operation of advanced technology and presents a methodical approach to performing common musical and technical challenges found in modern euphonium repertoire with electronic media. Included in this dissertation are tables of common audio vocabulary and images of connectors, safety precautions, equipment recommendations with performance settings, a list of required connectors, adapters, cables, speakers, and amplifiers, performance set up diagrams, background information, and analyses of both the technical and musical aspects of each piece. In the appendices are signal flow charts, visual illustrations of polar recording patterns, and an updated catalog of published and unpublished original, adapted, and arranged euphonium solos with live electronics and electronic media accompaniment between 1970 and 2017.
Date: August 2017
Creator: Ray, Irving

Neurocognitive Effects of Gist Reasoning Training in Student-Athletes with Concussions, ADHD, and Learning Disabilities

Description: Concussions, attention-deficit disorder (ADHD), and learning disabilities can adversely impact learning and academic achievement, particularly with respect to attention, memory, and executive functioning; fortunately, cognitive training can be beneficial and remediating these weaknesses. One such program, strategic memory advanced reasoning training (SMART), utilizes a top-down approach to train individuals in executive, higher-ordered thinking strategies including strategic attention, integration, and innovation to facilitate information synthesis and enhance cognitive efficiency. Thus, the purpose of the study is to examine whether SMART improved performances on various neuropsychological measures tapping into attention, processing speed, memory, and executive functioning for college student-athletes with neurological conditions (e.g., concussions, ADHD, LD). Student-athletes were randomly assigned to the SMART program or a "wait-list" control group and were administered a neuropsychological battery at baseline, immediately following the intervention, and after a four-month delay. Results showed that participants benefited from SMART with respect to working memory immediately following the intervention after controlling for baseline scores. The benefits of working memory also persisted after four months. Additionally, SMART was beneficial for improving attention, but only after four months after the intervention. The findings of the current study were consistent with previous studies which showed positive effects of SMART on working memory with a variety of populations (e.g., children, adolescents, older adults, Veterans, brain-injured patients); however, the current study did not see improved performance on other aspects of executive functioning which contradict prior research. Statistical differences between the present study and prior research regarding SMART may be explained in methodology, participant characteristics, research setting, and/or limitations. Future studies may include combining cognitive training as the intervention and utilizing neuroimaging alongside cognitive training to examine the relationship between structural/functional change with neuropsychological performance.
Date: August 2017
Creator: Nguyen, Thomas

An Investigation of the Impact of Social Vulnerability Research on the Practice of Emergency Management

Description: This dissertation examines the extent to which social vulnerability, as studied by researchers across multiple disciplines, has influenced the practice of emergency management at the local level. This study addresses two major research questions to accomplish this goal. First, how do local emergency managers perceive and define social vulnerability? Second, what strategies do local emergency managers employ to reach and meet the needs of socially vulnerable populations? Semi-structured interviews were conducted in person or by phone with a sample of local emergency managers, city managers, and American Red Cross personnel from the Houston - Galveston and the South East Texas regions as defined by the respective Councils of Government. A modified grounded theory approach was used with a constant comparative method to identify themes for each research question. Triangulation was accomplished through secondary census data and supplemental interviews. The interview data reveal that social vulnerability research has had an indirect influence on the practice of emergency management at the local level. This influence is facilitated through state and federal policy, training, and plans development. Based on the interview data, four themes were identified that capture the various ways in which local emergency management officials perceive and define social vulnerability. These include vulnerability as poverty and culture, vulnerability as a lack of security, vulnerability as a moral imperative, and vulnerability as a lack of awareness and knowledge. In terms of strategies employed to address social vulnerability, the data suggest four themes: leaving it to the professionals, bringing in volunteers, leveraging protocols to build buy-in, and fostering flexibility. The findings reveal the importance in closing the knowledge gap between research and practice, because increased damage, harm, and death can occur when the social inequalities of everyday life are not addressed in the planning process by emergency managers. The findings also reveal that ...
Date: August 2017
Creator: Williams, Brian Don

Formation Control of Multi-Agent Systems

Description: Formation control is a classical problem and has been a prime topic of interest among the scientific community in the past few years. Although a vast amount of literature exists in this field, there are still many open questions that require an in-depth understanding and a new perspective. This thesis contributes towards exploring the wide dimensions of formation control and implementing a formation control scheme for a group of multi-agent systems. These systems are autonomous in nature and are represented by double integrated dynamics. It is assumed that the agents are connected in an undirected graph and use a leader-follower architecture to reach formation when the leading agent is given a velocity that is piecewise constant. A MATLAB code is written for the implementation of formation and the consensus-based control laws are verified. Understanding the effects on formation due to a fixed formation geometry is also observed and reported. Also, a link that describes the functional similarity between desired formation geometry and the Laplacian matrix has been observed. The use of Laplacian matrix in stability analysis of the formation is of special interest.
Date: August 2017
Creator: Mukherjee, Srijita

Professional Learning Communities: A Comparative Case Study of Shared Personal Practice

Description: Effective instructional practice has a significant impact on student learning. Shared personal practice within a professional learning team (PLT) is one of the key elements in consistently improved instructional practice. However, this PLT characteristic is often the least evident and the hardest to absorb into PLT culture. This study examined the relational characteristics, facilitating factors, or barriers to shared personal practice within a PLT. Two PLTs in core subject areas across two Texas high school campuses were included in this comparative case study. Data from document analysis, PLC observations, focus group interviews, and in-depth individual interviews were examined thematically to answer the research questions guiding this study. The results of this study revealed that building strong relationships and an emphasis on collective creativity were strong predictors of sharing personal practice. Collective clarity on PLT practices and the purpose of sharing personal practice increased the success and occurrence of sharing personal practice. The results also revealed that the copious tasks of teaching and negative perceptions of being observed by colleagues hindered consistent sharing of personal practice. This study describes the current context of shared personal practice as a foundation for future studies to examine how practice can be transformed.
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Date: August 2017
Creator: Curtis, Anna E

Neurological Responses to a Glucose Diet in Caenorhabditis elegans

Description: TRPV channels play a role in both mammalian insulin signaling, with TRPV1 expression in pancreatic beta-cells, and in C. elegans insulin-like signaling through expression of OSM-9, OCR-1, and OCR-2 in stress response pathways. In response to a glucose-supplemented diet, C. elegans are know to have sensitivity to anoxic stress, exhibit chemotaxis attraction, and display reduced egg-laying rate. Transcriptome analysis reveals that glucose stimulates nervous system activity with increased transcript levels of genes regulating neurotransmitters. Ciliated sensory neurons are needed for a reduced egg-laying phenotype on a glucose-supplemented diet. Egg-laying rate is not affected when worms graze on glucose-supplemented Delta-PTS OP50 E. coli, which is defective in glucose uptake. This suggests a possible sensory neuron obstruction by exopolysaccharides produced by standard OP50 E. coli on glucose, eliciting a starvation response from the worm and causing reduced egg-laying rate. Glucose chemotaxis is affected in specific TRPV subunit allele mutants: ocr-2(vs29) and osm-9(yz6), serotonin receptor mutants: ser-1(ok345) and mod-1(ok103), and G-alpha protein mutant: gpa-10(pk362). TRPV deletion mutants had no effect on glucose chemotaxis, alluding to the modality role pf TRPV alleles in specific sensory neurons. The role of serotonin in a reduced egg-laying rate with glucose remains unclear.
Date: August 2017
Creator: Dumesnil, Dennis

"Among the Voices Voiceless": Setting the Words of Samuel Beckett

Description: Among the Voices Voiceless is a composition for flute (doubling piccolo), clarinet (doubling bass clarinet), viola, cello, percussion, piano, and electronics, based on the poem "What would I do without this world faceless incurious" by Samuel Beckett. The piece is a setting for disembodied voice: the vocal part exists solely in the electronics. Having no physical body, the voice is obscured as the point of empathy for the audience. In addition, instrumental solos compete for focus during the work's twenty minute duration. In passages including a soloist, the soloist functions simultaneously as antagonist and avatar to the disembodied voice. Spoken word recordings and electronic manipulation of instrumental material provides further layers of ambiguity. The companion critical essay "Among the Voices Voiceless": Setting the Words of Samuel Beckett proposes the distillation of Beckett's style into the elements of prosaicness, repetition, fragmentation, ambiguity, and symmetry. Discussions of Beckett's works such as Waiting for Godot and Molloy demonstrate these elements in his practice. This framework informs the examination of two other musical settings of Beckett's poetry: Neither by Morton Feldman and Odyssey by Roger Reynolds. Finally, these elements are used to analyze and elucidate the compositional decisions made in Among the Voices Voiceless.
Date: August 2017
Creator: Lyszczarz, Joseph E