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The Impact of End-user Decision-making in the Supply of Public Transportation

Description: Efficient public transportation provides economic and social opportunities that increase accessibility to markets and employment as well as providing investment benefits. Key challenges to the U.S. public transportation industry include developing modes and increasing the availability of public transportation in a manner that meets the needs of individual users in a cost effective manner. A problem facing public transportation officials is the need to understand the factors that influence consumer decision-making and consumer attitudes toward public transportation. Feedback regarding experiences as well as expectations from commuters provides information for developing and improving public transportation. Thus, decision-making factors of end-users are keys to improving supply, growth, and understanding utilization of public transportation. Public transportation officials seek to improve the public transportation experience for commuters by increasing modes and benefits of the systems. The decision-making factors of the end-users require identification and examination in order to provide a high quality and efficient experience for commuters. The research questions of interest in the current dissertation are: (1) What are the decision-making factors affecting commuters’ attitudes toward public transportation? and (2) How do the end-user decision-making factors affect the supply of public transportation? The purpose of this research is to extend the current body of knowledge about decision-making factors by developing and testing a new theoretical model to measure the attitudes of public transportation end-users. This study has its theoretical foundation in the theory of planned behavior, theory of reasoned action, and rational choice theory. To understand how public transportation is affected by decision-making factors, it is necessary to analyze the relationships among the decision factors and attitudes. The findings of this study contribute by building theory and having implications for practice. This study employs a mixed methodology of qualitative and quantitative research. More specifically, the development of a framework and testing of that ...
Date: May 2015
Creator: Scott, Rebecca A.
Partner: UNT Libraries

Plasma Interactions on Organosilicate Glass Dielectric Films and Emerging Amorphous Materials- Approach to Pore Sealing and Chemical Modifications

Description: In-situ x-ray photoemission (XPS) and ex-situ FTIR studies of nanoporous organosilicate glass (OSG) films point to the separate roles of radicals vs. VUV photons in the carbon abstraction. The studies indicate that reaction with O2 in presence of VUV photons (~123 nm) result in significant carbon abstraction within the bulk and that the kinetics of this process is diffusion-limited. In contrast, OSG exposed to atomic O (no VUV) results in Si-C bond scission and Si-O bond formation, but this process is self-limiting after formation of ~1 nm thick SiO2 surface layer that inhibits further diffusion. Therefore, the diffusion-dominated kinetics of carbon abstraction observed for OSG exposed to O2 plasma is definitively attributed to the diffusion of O2 down OSG nanopores, reacting at photo-activated sites, rather than to the diffusion of atomic O. Pretreatment of OSG by 900 eV Ar+ ion bombardment also results in formation of 1 nm thick SiO2-like surface overlayer that inhibits O2 diffusion, inhibiting VUV+O2 and O2 plasma-induced reactions, and that the effectiveness of this treatment increases with ion kinetic energy. On the contrary, organosilicate glass (OSG) films with backbone carbon (-Si-R-Si-) exhibit significantly enhanced resistance to carbon loss upon exposure to O2 plasma, radicals and VUV+O2 compared to films with terminal methyl groups (Si-CH3). Films incorporating backbone carbon chains (-Si-R-Si-) were deposited from 1,2 bis (triethoxysilyl) ethane (BTESE) precursor by ebeam or plasma cross-linking. The radical effects on BTESE film indicates negligible carbon loss or Si oxidation, combined with C-O bond formation, under conditions where OSG films with terminal methyl groups exhibit > 80% carbon loss within the surface region of the film. C-O bond formation is never observed for terminal CH3 groups. Further, backbone carbon (-Si-R-Si-) films exposed to VUV+O2 exhibit self-limiting, minimal net carbon loss. This indicates that plasma-induced Si-C bond rupture still occurs ...
Date: May 2015
Creator: Kazi, Haseeb
Partner: UNT Libraries

Forward Genetic Characterization of Medicago truncatula Tnt1 Insertion Mutants Defective in Nodule Development and Symbiotic Nitrogen Fixation

Description: Legumes are unique plants because they form special structures “nodules”, via symbiotic relationships with rhizobial bacteria present in the soil. Once rhizobia mature inside nodules, they fix atmospheric nitrogen providing a source of bioavailable nitrogen to the plant. To discover novel genetic components involved in the legume-rhizobia symbiosis by using forward genetic screening, we have isolated Medicago truncatula Tnt1 insertion mutants in the R108 ecotype, which are defective in nodule development and symbiotic nitrogen fixation in response to Sinorhizobium meliloti. Out of three mutants NF11044, NF11217 and NF8324, one of the mutants showed brown nodules and Fix- phenotype that is defective in symbiotic nitrogen fixation. The other two mutants showed white nodules and Fix- phenotype, also indicator of defects in symbiotic nitrogen fixation. To identify the underlying mutation causing the phenotype, we have developed molecular genetic markers by obtaining genomic sequences flanking the Tnt1 insertions by TAIL-PCR and Illumina sequencing. To carry out co-segregation analysis, back-crossed BC1F2 segregating populations were obtained. These are being phenotyped, genotyped and analyzed for co-segregation of the phenotype with the Tnt1 genetic markers. Back-crossing also has the effect of reducing the Tnt1 insertions, which are not linked to the nodulation defective phenotypes. Out of the three mutants, NF8324 harbors exactly the same insertion as in the rsd-1 Tnt1 mutant NF11265. The defect in NF11217 is caused by a Tnt1 insertion in the previously described PLC gene; the site of this insertion is close to that found in a different mutant, NF0217. For mutant NF11044, we developed linkage markers that place the defective locus on chromosome 7. To further characterize co-segregation in NF11044, a mapping population has been created by crossing the mutant with other ecotypes: A17 and A20. We tested mutants and wild type plants with linkage marker A20 X NF11044 BC1F2 that segregates 3:1(wild ...
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Date: May 2015
Creator: Kadel, Khem L.
Partner: UNT Libraries

A Case Study of an Urban Charter School’s Journey of School Improvement: Organizational Theory, Institutional Learning and School Reform

Description: The problem for this study was the need to increase and maintain in student achievement in charter schools. The purpose of this single-case study was to discover how an inner city charter school with a high percentage of at-risk students increased overall student achievement and attained acceptable performance status when faced simultaneously with administrative challenges and increases in state and federal standards. The participants for the single-case study included the school district’s superintendent, the high school principal, the dean of students, four faculty of the district, and one outside consultant appointed to work with the district by the state of Texas. The sampling for this study allowed for the opportunity to study in greater depth the choice of reform strategies and organizational structure designed to result in increased student achievement and student success over the course of two years. Since this was a single-case study of one charter school district, participants were referenced by the role in which they served. All district, campus, and participant names remained anonymous. The results showed the increased student achievement was made possible by several reform strategies and best practices. The primary reform strategies and best practices that had the greatest impact were consistent campus leadership and parent and community involvement with the campus. Mission and focus were secondary strategies that contributed to increasing teacher effectiveness and student achievement. All of the interviewees stated their work was “all about the kids” to support the theme of the common mission and focus the campus and district.
Date: May 2015
Creator: Subjinski, Amanda
Partner: UNT Libraries

What Did the Client Say? Auditor Memory of a Client Inquiry: a Study of Encoding Style and Note Taking

Description: Client inquiry is a fundamental procedure for gathering audit evidence. Since inquiries are not audio- or video-recorded in practice, auditor memory is vital to the accuracy of evidence gathered in this manner. Due to the potential for error during memory encoding and retrieval, the effect of memory on judgment, and the cognitive complexity of conducting a face-to-face inquiry, examining factors affecting auditor memory of client inquiries is important. In this dissertation, I examine two factors likely to affect auditor memory of a client inquiry. First, encoding style is a low-level cognitive function representing how much stimuli an individual perceives before applying prior knowledge (schemata) to assist with encoding to long-term memory, affecting information noticed and remembered. Differences in auditors’ encoding style may explain variance in memory accuracy of evidence gathered from a client inquiry. Second, audit professionals often make hand-written or typed notes during client inquiries, and subsequently review the notes, which may affect memory. To address these issues, I first gather interview evidence from six professional auditors to determine how practicing auditors plan, prepare for, conduct, and document evidence from client inquiries. I then develop and execute a video-based experiment with 33 senior auditor participants, 23 masters-level accounting students, and 47 undergraduate-level accounting students to investigate whether encoding style and note taking affect auditor memory accuracy of, and audit judgments resulting from, a client inquiry. I find multiple significant results. First, I find that encoding style affects memory accuracy such that auditors quickly utilizing prior knowledge during an inquiry results in greater memory accuracy than auditors slowly utilizing prior knowledge. This finding suggests that quickly utilizing prior knowledge helps auditors to manage the cognitive complexity of a client inquiry. Second, I find that participants who take notes during an inquiry, and subsequently review his or her notes taken, have ...
Date: May 2015
Creator: Vinson, Jeremy M.
Partner: UNT Libraries

Adult Attachment, Acculturation, and Help-seeking Attitudes of Latino College Students

Description: Based on theoretical reasoning and empirical evidence, the present study examined the unique and shared effects of attachment anxiety, attachment avoidance, and acculturation on attitudes toward seeking professional help among Latino college students. The research participants included 149 bilingual Latino college students from a large, public southwestern university. Results of a multiple regression analysis indicated that attachment avoidance was positively associated with both the recognition of need for psychological help and stigma of seeking professional help. Acculturation to American society was found to be statistically insignificant in predicting help-seeking attitudes in this sample of the population. Findings from exploratory questions suggested that Latino individuals would most likely seek help from parents, close friends, and then professionals. This study suggested that Latino individuals with high attachment avoidance acknowledge the potential benefit of professional help-seeking but distrust the process of approaching others for help. Limitations, implications, and future research directions will be discussed.
Date: May 2015
Creator: Zamudio, Gabriel
Partner: UNT Libraries

Ideal Learning Spaces: the Student Perspective

Description: Classrooms, libraries, student unions, and university campuses shape students’ learning experiences. These physical learning spaces set the stage for college student engagement and academic performance. Most of the research about the role of physical spaces in learning lacks the student perspective. The goal of this study was to offer a student-centered vision of ideal learning spaces. Students are the learners for whom learning spaces are designed, and this thesis examines the way students of one summer class at Oklahoma Baptist University conceptualized and interacted with their learning spaces. Data collection included surveys of the students, a focus group with members of the class, participant observation in the classroom, and interviews with students and the professor. Students viewed physical spaces as the backdrop for human action and chose spaces that supported their learning styles and goals. Students described supportive spaces as warm, purposefully crafted spaces, and full of other people who were seriously pursuing the same goals. This thesis explores the ways students conceptualized and interacted with learning spaces as a network of support for their learning and provides recommendations for the design of learning spaces that facilitate this support.
Date: May 2015
Creator: Sidler, Elizabeth D.
Partner: UNT Libraries

Zooarchaeology and Biogeography of Freshwater Mussels in the Leon River During the Late Holocene

Description: The Leon River, a small-medium river in central Texas, is highly impacted by multiple impoundments, enrichment from agricultural runoff, and decreased dissolved oxygen levels. This degraded river contains sixteen unionid species, two of which are both endemic to the region and candidates for the federal endangered species listing (Quadrula houstonensis and Truncilla macrodon). While there is a short historical record for this river basin and a recent modern survey completed in 2011, zooarchaeological data adds evidence for conservation efforts by increasing the time depth of data available and providing another conservation baseline. Zooarchaeological data for the Leon River is available from the two Late Holocene archaeological sites: 41HM61 and the Belton Lake Assemblages. Data generated from these assemblages describe the prehistoric freshwater mussel community of the Leon River in terms of taxonomic composition and structure. By comparing this zooarchaeological data to the data generated by the longitudinal modern survey of the Leon River, long term changes within the freshwater mussel community can be detected. A conceptual model is constructed to evaluate how robusticity, identifiability, and life history ecology affect unionid taxonomic abundances in zooarchaeological data. This conceptual model functions as an interpretive tool for zooarchaeologists to evaluate forms of equifinality in zooarchaeological assemblages. This thesis determines differences between the late Holocene and modern freshwater community of the Leon River, explores how different alternative mechanisms influence zooarchaeological data, and exemplifies of how zooarchaeological data can be used for conservation biology.
Date: May 2015
Creator: Popejoy, Traci Glyn
Partner: UNT Libraries

Applications of Single Reference Methods to Multi-Reference Problems

Description: Density functional theory is an efficient and useful method of solving single-reference computational chemistry problems, however it struggles with multi-reference systems. Modifications have been developed in order to improve the capabilities of density functional theory. In this work, density functional theory has been successfully applied to solve multi-reference systems with large amounts of non-dynamical correlation by use of modifications. It has also been successfully applied for geometry optimizations for lanthanide trifluorides.
Date: May 2015
Creator: Jeffrey, Chris C.
Partner: UNT Libraries

Investigation on Segmentation, Recognition and 3D Reconstruction of Objects Based on LiDAR Data Or MRI

Description: Segmentation, recognition and 3D reconstruction of objects have been cutting-edge research topics, which have many applications ranging from environmental and medical to geographical applications as well as intelligent transportation. In this dissertation, I focus on the study of segmentation, recognition and 3D reconstruction of objects using LiDAR data/MRI. Three main works are that (I). Feature extraction algorithm based on sparse LiDAR data. A novel method has been proposed for feature extraction from sparse LiDAR data. The algorithm and the related principles have been described. Also, I have tested and discussed the choices and roles of parameters. By using correlation of neighboring points directly, statistic distribution of normal vectors at each point has been effectively used to determine the category of the selected point. (II). Segmentation and 3D reconstruction of objects based on LiDAR/MRI. The proposed method includes that the 3D LiDAR data are layered, that different categories are segmented, and that 3D canopy surfaces of individual tree crowns and clusters of trees are reconstructed from LiDAR point data based on a region active contour model. The proposed method allows for delineations of 3D forest canopy naturally from the contours of raw LiDAR point clouds. The proposed model is suitable not only for a series of ideal cone shapes, but also for other kinds of 3D shapes as well as other kinds dataset such as MRI. (III). Novel algorithms for recognition of objects based on LiDAR/MRI. Aimed to the sparse LiDAR data, the feature extraction algorithm has been proposed and applied to classify the building and trees. More importantly, the novel algorithms based on level set methods have been provided and employed to recognize not only the buildings and trees, the different trees (e.g. Oak trees and Douglas firs), but also the subthalamus nuclei (STNs). By using the novel algorithms based ...
Date: May 2015
Creator: Tang, Shijun
Partner: UNT Libraries

Pastoral Livelihoods and Household Water Management in the Central Argentine Andes

Description: Pastoralists tend to occupy highlands and drylands lands with uncertain climates and are experienced at coping with climatic variability and drought. Increasingly, however, the speed with which climate patterns are changing has become an issue of concern. This study examines household water management strategies of pastoralists in western Argentina. In this semi-arid region, pastoralists rely primarily on streams and springs fed by snow and glacier melt from the Andes, and have developed various strategies to meet their water needs. They also deal with myriad challenges posed by climate, economic, and socio-cultural change and work vigorously to maintain their herds – a combination of cattle, goats, and sheep – in this water scarce region. The goal of this study is to understand: 1) different household water management strategies; 2) the ways pastoral livelihoods are changing in response to changes in water supply; and 3) the socio-economic changes that affect pastoral livelihoods. Information from interviews, household surveys, and participant observations reveals that climate fluctuation impacts water supplies and use, herd size, and expenses made on tanks, technology, and infrastructure for the storage and transport of water, food for animals, and subsistence crops. Understanding the micro-scale, water practices of pastoral households provides insight into the ways rural populations in semi-arid and arid environments respond to changes in climate and meet their water needs. Moreover, these findings can contribute to scholarship on traditional and local knowledge and resource management systems, and may potentially inspire the development of adaptive management solutions.
Date: May 2015
Creator: Parker, Julie
Partner: UNT Libraries

Space and Spectrum Engineered High Frequency Components and Circuits

Description: With the increasing demand on wireless and portable devices, the radio frequency front end blocks are required to feature properties such as wideband, high frequency, multiple operating frequencies, low cost and compact size. However, the current radio frequency system blocks are designed by combining several individual frequency band blocks into one functional block, which increase the cost and size of devices. To address these issues, it is important to develop novel approaches to further advance the current design methodologies in both space and spectrum domains. In recent years, the concept of artificial materials has been proposed and studied intensively in RF/Microwave, Terahertz, and optical frequency range. It is a combination of conventional materials such as air, wood, metal and plastic. It can achieve the material properties that have not been found in nature. Therefore, the artificial material (i.e. meta-materials) provides design freedoms to control both the spectrum performance and geometrical structures of radio frequency front end blocks and other high frequency systems. In this dissertation, several artificial materials are proposed and designed by different methods, and their applications to different high frequency components and circuits are studied. First, quasi-conformal mapping (QCM) method is applied to design plasmonic wave-adapters and couplers working at the optical frequency range. Second, inverse QCM method is proposed to implement flattened Luneburg lens antennas and parabolic antennas in the microwave range. Third, a dual-band compact directional coupler is realized by applying artificial transmission lines. In addition, a fully symmetrical coupler with artificial lumped element structure is also implemented. Finally, a tunable on-chip inductor, compact CMOS transmission lines, and metamaterial-based interconnects are proposed using artificial metal structures. All the proposed designs are simulated in full-wave 3D electromagnetic solvers, and the measurement results agree well with the simulation results. These artificial material-based novel design methodologies pave the way ...
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Date: May 2015
Creator: Arigong, Bayaner
Partner: UNT Libraries

A Restorative Environmental Justice for the Prison Industrial Complex: a Transformative Feminist Theory of Justice

Description: This dissertation provides a feminist restorative model of environmental justice that addresses the injustices found within UNICOR’s e-waste recycling operations. A feminist restorative environmental justice challenges the presupposition that grassroots efforts, law and policy, medical and scientific research, and theoretical pursuits (alone or in conjunction) are sufficient to address the emotional and relational harm of environmental injustices. To eliminate environmental harms, this model uses collaborative dialogue for interested parties to prevent environmental harm. To encourage participation, a feminist restorative model accepts many forms of knowledge and truth as ‘legitimate’ and offers an opportunity for women to share how their personal experiences of love, violence, and caring differ from men and other women and connect to larger social practices. This method of environmental justice offers opportunities for repair, reparation and reintegration that can transform perspectives on criminality, dangerous practices and structures in the PIC, and all persons who share in a restorative encounter.
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Date: May 2015
Creator: Conrad, Sarah M.
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Examining Self-efficacy in Community College Adjunct Faculty

Description: Though professional development interventions are widespread in higher education, administrators often do not formally assess their effectiveness, particularly in relation to teacher self-efficacy. The purposes of this study were to determine if any statistically significant difference existed between the self-efficacy scores of adjunct faculty participants in a community college’s professional development program and nonparticipants and to identify the variables with a statistically significant relationship with self-efficacy. A modified version of the Teachers’ Sense of Efficacy Scale (TSES) was administered to 21 adjunct faculty participants in Lone Star College’s Adjunct Certification Program (ACP) and 312 adjunct faculty not currently participating in the program. A demographic questionnaire development by the researcher was also administered. Independent variables of the demographic questionnaire included gender, ethnicity, age, K-12 teaching experience, highest degree earned, subject taught, years of college teaching experience, and number of courses taught each semester. Paired t-test results indicated statistically significant differences in Efficacy in Instructional Strategies for adjunct participants in the ACP program. No significant differences were found for Efficacy in Student Engagement and Efficacy in Classroom Management. Multiple regression analyses indicated that gender has a statistically significant relationship to Efficacy Instructional Strategies. A statistically significant relationship was found for race for Efficacy in Classroom Management. Finally, analysis also indicated a positive relationship between race and gender for Efficacy in Student Engagement. No other statistically significant relationships were found across the other demographic variables. Findings of this study revealed that the ACP increased teacher self-efficacy across two of the three dimensions of the TSES indicating that the professional development intervention had a positive effect on the efficacy of its participants. The present study contributes to the research on teacher self-efficacy, adjunct faculty and professional development interventions.
Date: May 2015
Creator: Weisel, Jessica W.
Partner: UNT Libraries

Effects of Auditor-provided Tax Services on Book-tax Differences and Investors’ Mispricing of Book-tax Differences

Description: In this study, I investigate the effect of auditor-provided tax services (ATS) on firms’ levels of book-tax differences and investors’ mispricing of book-tax differences. The joint provision of audit and tax services has been a controversial issue among regulators and academic researchers. Evidence on whether ATS improve or impair the overall accounting quality is inconclusive as a result of the specific testing circumstances involved in different studies. Book-tax differences capture managers’ earnings management and/or tax avoidance intended to maximize reported financial income and to minimize tax expense. Therefore, my first research question investigates whether ATS improve or impair audit quality by examining the relation between ATS and firms’ levels of book-tax differences. My results show that ATS are negatively related to book-tax differences, suggesting that ATS improve the overall audit quality and reduce aggressive financial and/or tax reporting. My second research question examines whether the improved earnings quality for firms acquiring ATS leads to reduced mispricing of book-tax differences among investors. Recent studies document that despite the rich information about firms’ future earnings contained in book-tax differences, investors process such information inefficiently, leading to systematic pricing errors among firms with large book-tax differences. My empirical evidence indicates that ATS mitigate such mispricing, with pricing errors being lower among firms acquiring ATS compared with firms without ATS. Collectively, these results support the notion that ATS improve audit quality through knowledge spillover. Moreover, the improved earnings quality among firms acquiring ATS in turn helps reduce investors’ mispricing of book-tax differences.
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Date: May 2015
Creator: Luo, Bing
Partner: UNT Libraries

Application of Cyclic Polarization of Aluminum 3003 Used in All-Aluminum Microchannel Heat Exchangers

Description: All-aluminum microchannel heat exchangers are designed to significantly reduce refrigerant charge requirements, weight, reduced brazed joints, and decreased potential for leakage by increasing reliability. Al 3003 alloy is corrosion resistant and can be formed, welded, and brazed but the issue with all-aluminum heat exchangers is localized corrosion (pitting) in corrosive environments. Currently, there is no universally accepted corrosion test that all coil manufacturers use to characterize their products. Electrochemical testing method of cyclic polarization was employed in this investigation and relevant parameters including electrolyte corrosive agent and its concentration, electrolyte pH, and applied potential scan rate was varied to find an optimal set of parameters. Results of cyclic polarization of Al 3003 in electrolytes containing various concentrations of NaCl were compared with those of the tests in Sea Water Acidified Accelerated Test (SWAAT) electrolyte and it is shown the SWAAT electrolyte (4.2% sea salt acidified to pH of 2.9) is by far stronger (in terms of corrosivity) than typical 3.5% NaCl solution used in most corrosion testing. Corrosion rates (g/m2yr) of Al 3003 measured in this investigation were comparable to those provided by ISO 9223 standard corresponding to C1 through CX categories. Duration of cyclic polarization test is much shorter than that of SWAAT and results obtained in this test is more reproducible compared to those of SWAAT. Scanning electron microscopy micrographs show typical pit depths of about 50 μm.
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Date: May 2015
Creator: Barnes, Javier
Partner: UNT Libraries

The Intervention of Human Modifications on Plant and Tree Species in the Landscape of the LBJ National Grasslands

Description: An analysis utilizing both ArcGIS and ethnographic interviews from private land owners and environmental professionals examined how man-made landscape changes affected plant and tree species in the LBJ National Grasslands in Wise County, Texas north of Decatur. From the late 1800s to the Dust Bowl Era the land was used for crop production and cattle grazing resulting in erosion and loss of soil nutrients. The research indicated by 2001 that cattle grazing and population increase resulted in land disturbance within the administrative boundary of the national grasslands. Participants expressed concern over the population increase and expansion of 5 to 10 acre ranchettes for cattle grazing common in modern times. Recommendations for the future included utilizing and expanding the resources already existing with environmental professionals to continue controlling erosion.
Date: May 2015
Creator: Lang, Brett M.
Partner: UNT Libraries

The Effect of Curcumin Supplementation on Physical and Biological Indices of Delayed Onset Muscle Soreness and Inflammation Following Muscle Injury

Description: In this project, the effects of dietary polyphenols on exercise-induced muscle damage and vascular health are examined. Dietary polyphenols exert well-known anti-inflammatory effects; however, how these effects are realized with respect to vascular health and EIMD is relatively unknown. I begin by reviewing the available literature surrounding the impact of three dietary polyphenols (curcumin, catechins, and quercetin) on inflammation associated with EIMD. It is well established that their primary means of anti-inflammation is through alterations of NF-κB and AP-1 transcription activities. Given this, their inclusion into training strategies seems reasonable. Consistent evidence is presented making a case for the anti-inflammatory effects of dietary polyphenols following EIMD. I follow this review up by completing an in-depth study on the consumption of curcumin prior to EIMD. I found curcumin (1000 mg/day) can reduce subjective soreness and decrease inflammation compared to placebo controls. To further understand the effects of dietary polyphenols on health, I investigate the effects of a four-week supplementation period of cocoa (catechins) on vascular. I concluded that atherogenic risk in obese women is reduced after consumption of cocoa. In addition to these experimental projects, I developed two novel methods that can be used to investigate vascular health (EMP concentration) and intracellular protein and mRNA production using flow cytometry.
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Date: May 2015
Creator: Venable, Adam Steven
Partner: UNT Libraries

A Multimodal Investigation of Renewal of Human Avoidance, Perceived Threat, and Emotion

Description: Many people who receive exposure-based treatments for anxiety disorders exhibit a return of fear and avoidance which is often referred to as renewal or relapse. Human and nonhuman research on fear conditioning and renewal has been instrumental in helping understand relapse in anxiety disorders. The purpose of this investigation was to examine renewal of human avoidance and assess whether avoidance may aid in sustaining renewal of fear responses. We adopted a multimodal measurement approach consisting of an approach-avoidance task along with ratings of perceived threat and fear and measures of skin-conductance, a widely used physiological measure of fear. A traditional, single-subject research design was used with six healthy adults. All tasks employed a discrete trial procedure. Experimental conditions included Pavlovian fear conditioning in which increased probability of money loss was paired with a “threat” meter in Context A and later followed extinction in Context B. Fear and avoidance increased to higher threat levels in Context A but not Context B. Renewal testing involved presenting the threat meter on a return to Context A to determine if it evoked fear and avoidance (i.e., relapse). As predicted, renewal testing in Context A showed that increased threat was associated with increased avoidance, ratings of perceived threat and fear, and higher skin-conductance. Moreover, results showed that renewal maintained over six blocks of trials. This is the first investigation of renewal of threat and avoidance in humans that highlights avoidance as a mechanism that may contribute to maintaining fear in anxiety pathology.
Date: May 2015
Creator: Ludlum, Madonna L.
Partner: UNT Libraries

(Some More) American Literature

Description: This short story collection consists of twenty short fictions and a novella. A preface precedes the collection addressing issues of craft, pedagogy, and the post Program Era literary landscape, with particular attention paid to the need for empathy as an active guiding principle in the writing of fiction.
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Date: May 2015
Creator: VandeZande, Zach
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Pathways for C—H Activation and Functionalization by Group 9 Metals

Description: As fossil fuel resources become more and more scarce, attention has been turned to alternative sources of fuels and energy. One promising prospect is the conversion of methane (natural gas) to methanol, which requires an initial activation of a C-H bond and subsequent formation of a C-O bond. The most well studied methodologies for both C-H activation and C-O bond formation involve oxidation of the metal center. Metal complexes with facile access to oxidation states separated by four charge units, required for two subsequent oxidations, are rare. Non-oxidative methods to perform C-H bond activation or C-O bond formation must be pursued in order for methane to methanol to become a viable strategy. In this dissertation studies on redox and non-redox methods for both C-H activation and C-O bond formation are discussed. In the early chapters C-O bond formation in the form of reductive functionalization is modeled. Polypyridine ligated rhodium complexes were studied computationally to determine the properties that would promote reductive functionalization. These principles were then tested by designing an experimental complex that could form C-O bonds. This complex was then shown to also work in acidic media, a critical aspect for product stabilization. In the later chapters, non-oxidative C-H activation is discussed with Ir complexes. Both sigma bond metathesis and concerted metalation deprotonation were investigated. For the former, the mechanism for an experimentally known complex was elucidated and for the latter the controlling factors for a proposed catalyst were explored.
Date: May 2015
Creator: Pahls, Dale R.
Partner: UNT Libraries

Distributed Frameworks Towards Building an Open Data Architecture

Description: Data is everywhere. The current Technological advancements in Digital, Social media and the ease at which the availability of different application services to interact with variety of systems are causing to generate tremendous volumes of data. Due to such varied services, Data format is now not restricted to only structure type like text but can generate unstructured content like social media data, videos and images etc. The generated Data is of no use unless been stored and analyzed to derive some Value. Traditional Database systems comes with limitations on the type of data format schema, access rates and storage sizes etc. Hadoop is an Apache open source distributed framework that support storing huge datasets of different formatted data reliably on its file system named Hadoop File System (HDFS) and to process the data stored on HDFS using MapReduce programming model. This thesis study is about building a Data Architecture using Hadoop and its related open source distributed frameworks to support a Data flow pipeline on a low commodity hardware. The Data flow components are, sourcing data, storage management on HDFS and data access layer. This study also discuss about a use case to utilize the architecture components. Sqoop, a framework to ingest the structured data from database onto Hadoop and Flume is used to ingest the semi-structured Twitter streaming json data on to HDFS for analysis. The data sourced using Sqoop and Flume have been analyzed using Hive for SQL like analytics and at a higher level of data access layer, Hadoop has been compared with an in memory computing system using Spark. Significant differences in query execution performances have been analyzed when working with Hadoop and Spark frameworks. This integration helps for ingesting huge Volumes of streaming json Variety data to derive better Value based analytics using Hive and ...
Date: May 2015
Creator: Venumuddala, Ramu Reddy
Partner: UNT Libraries

Determinants of Citizens’ 311 Use Behaviors: 311 Citizen-initiated Contact, Contact Channel Choice, and Frequent Use

Description: Facing increasingly complex policy issues and diminishing citizen satisfaction with government and service performance, managing the quality of citizen relationship management has become a main challenge for public managers. Solutions to complex policy problems of service performance and low level of citizen participation often must be developed by encouraging citizens to make their voices heard through the various participation mechanisms. Reflecting on this need, the municipal governments in the U.S. have developed centralized customer systems for citizen relationship management. 311 centralized customer system (named 311 in this study) has the functions of citizen-initiated contact, service-coproduction, and transaction, and many local governments launch 311 to maintain or enhance their relationship with the public. Using 311 is an easy and free technically for citizens, but ensuring some degree of citizen engagement and citizens’ 311 use has been challenging for local public managers of municipalities. Despite calls for the importance of 311 in the service and information delivery process, fair treatment and access to use of governmental information, citizen participation, government responsiveness, and citizen satisfaction, to the best of our understanding, no empirical studies explore citizens’ 311 behaviors in the micro and individual level in the field of public administration. This dissertation provides a comprehensive understanding of the 311 centralized customer system, helps local public managers know citizens’ perceived perspectives toward the operation of 311, and assists these managers to develop an effective 311 system in municipalities. The dissertation’s main purpose is to clarify the importance of 311 to citizen relationship management and provide insights into citizens’ 311 use behaviors. More specifically, this dissertation tries to answers the following questions: a. Why do citizens use 311? Do the various groups of the population access and use 311 in San Francisco equally? If not, what factors influence the citizens’ 311 citizen-initiated contact behaviors? b. ...
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Date: May 2015
Creator: Wu, Wei-Ning
Partner: UNT Libraries

Cytotoxicity and Functional Toxicity of Mefloquine and the Search for Protective Compounds

Description: Mefloquine hydrochloride is an antimalarial agent that has been used for the past 40 years. Numerous reports of neurological side effects have recently led the FDA to issue a strong warning regarding long-term neurological effects. This warning lead to the U.S. Army’s Special Forces and other components to discontinue its use in July of 2013. Despite reported adverse side effects, mefloquine remains in circulation and is recommended to travelers going to specific Asian countries. Mefloquine has been used as a treatment for those already infected with the malaria parasite (blood concentrations ranging from 2.1 to 23 µM), and as prophylaxis (blood concentrations averaging 3.8 µM) (Dow 2003). The purpose of this study was to quantify Mefloquine’s toxicity using spontaneously active nerve cell networks growing on microelectrode arrays in vitro and to identify compounds that alleviate or reduce toxic effects. The current literature on mefloquine toxicity is lacking electrophysiological data. These data will contribute to research on the mechanism of adverse side effects associated with mefloquine use. Sequential titration experiments were performed by adding increasing concentrations of mefloquine solution to cultured neurons. Network responses were quantified and reversibility was examined. In each network, activity decreases were normalized as a percent of reference activity yielding a mean IC50 value of 5.97 ± 0.44 (SD) µM (n=6). After total activity loss, no activity was recovered with two successive medium changes. To test for network response desensitization resulting from sequential applications over 5-6 hr periods, one-point titrations at varying concentrations were conducted with fresh networks. These experiments yielded a single concentration response curve with an IC50 value of 2.97 µM. This represents a statistically significant shift (p < 0.0001) to lower concentrations of mefloquine, demonstrating that sequential applications result in network desensitization. After mefloquine exposures, cells were evaluated for irreversible cytotoxic damage. Over a ...
Date: May 2015
Creator: Holmes, Katelyn
Partner: UNT Libraries