UNT Theses and Dissertations - 305 Matching Results

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Developing Policy for a Tech Program Based on Understanding Organizational Practices

Description: This thesis contributes to research that informs the studies of organizational management and organizational anthropology. It examines the internal hierarchy and organizational practices of a Tech Company and describes how findings contributed to policy recommendations aimed towards supporting a “guild” model for organizational success. The data collecting and research were undertaken while working as an employee of the Tech Program and subsequent analysis continued past the end of that phase of work. Methods included semi-structured interviews which captured the sentiments and understandings of employees within the organization, and a questionnaire which revealed sentiments and experiences from former employees. These were buttressed with participant observation engaged through a participatory action research methodology. Findings add to the work directed towards understanding the effect of Founder’s Syndrome within organizations. Additionally, this thesis contributes to a growing body of research centered on best practices for fostering positive organizational growth by creating lines of communication from front-line employees to management level employers.
Date: May 2016
Creator: Machado Perez, Luis Daniel
Partner: UNT Libraries

Development of an Instrument to Measure the Level of Acceptability and Tolerability of Cyber Aggression: Mixed-Methods Research on Saudi Arabian Social Media Users

Description: Cyber aggression came about as a result of advances in information communication technology and the aggressive usage of the technology in real life. Cyber aggression can take on many forms and facets. However, the main focus of this study is cyberbullying and cyberstalking through information sharing practices that might constitute digital aggressive acts. Human aggression has been extensively investigated. Studies focusing on understanding the causes and effects that can lead to physical and digital aggression have shown the prevalence of cyber aggression in different settings. Moreover, these studies have shown strong relationship between cyber aggression and the physiological and physical trauma on both perpetrators and their victims. Nevertheless, the literature shows a lack of studies that could measure the level of acceptance and tolerance of these dangerous digital acts. This study is divided into two main stages; Stage one is a qualitative pilot study carried out to explore the concept of cyber aggression and its existence in Saudi Arabia. In-depth interviews were conducted with 14 Saudi social media users to collect understanding and meanings of cyber aggression. The researcher followed the Colaizzi’s methods to analyze the descriptive data. A proposed model was generated to describe cyber aggression in social media applications. The results showed that there is a level of acceptance to some cyber aggression acts due to a number of factors. The second stage of the study is focused on developing scales with reliable items that could determine acceptability and tolerability of cyber aggression. In this second stage, the researcher used the factors discovered during the first stage as source to create the scales’ items. The proposed methods and scales were analyzed and tested to increase reliability as indicated by the Cronbach’s Alpha value. The scales were designed to measure how acceptable and tolerable is cyber-bullying, cyber-stalking in Saudi ...
Date: May 2016
Creator: Albar, Ali A
Partner: UNT Libraries

Development of an Outcome Measure for Use in Psychology Training Clinics

Description: The ability to monitor client change in psychotherapy over time is vital to quality assurance in service delivery as well as the continuing improvement of psychotherapy research. Unfortunately, there is not currently a comprehensive, affordable, and easily utilized outcome measure for psychotherapy specifically normed and standardized for use in psychology training clinics. The current study took the first steps in creating such an outcome measure. Following development of an item bank, factor analysis and item-response theory analyses were applied to data gathered from a stratified sample of university (n = 101) and community (n = 261) participants. The factor structure did not support a phase model conceptualization, but did reveal a structure consistent with the theoretical framework of the research domain criteria (RDoC). Suggestions for next steps in the measure development process are provided and implications discussed.
Date: May 2017
Creator: Davis, Elizabeth C.
Partner: UNT Libraries

Dimensions of Acculturation and Sexual Health among U.S. Hispanic Youth

Description: Hispanic youth living in the U.S. share a disproportionate burden of risk for HIV, other STIs, and teen pregnancies. They also tend to report lower rates of condom use and higher rates of inconsistent condom use than other racial/ethnic groups. Furthermore, immigrant Hispanic adolescents experience a unique burden of sexual risk compared to their non-immigrant counterparts. These negative sexual health outcomes can severely derail the overall health, social mobility, and life opportunities of these adolescents. Social researchers have tried to explain these sexual risk disparities using the concept of immigrant acculturation, which is broadly defined as the process of adopting the cultural values and beliefs of a host society. Immigrant acculturation has been shown to play a key role in shaping youth attitudes and behaviors, including sexual risk behaviors (see Lee & Hahm, 2010). Yet, studies have largely overlooked the contextual components of acculturation that have been proposed in theoretical literature, specifically characteristics of the immigrant's receiving community. Furthermore, studies have not adequately explored the influence of acculturation on two crucial measures of sexual risk: teen pregnancy norms and condom use. Therefore, the current dissertation consists of two unique studies that examine the influence of acculturation, at both the individual and neighborhood level, on Hispanic adolescent teen pregnancy norms and condom use over time. The aim is to fill these important gaps in the literature and expand on earlier explanations of the relationship between cultural, place, and long-term sexual health. Both studies use nationally-representative data from the National Longitudinal Study of Adolescent to Adult Health. Overall, findings suggest an immigrant advantage for both teen pregnancy norms and condom use, although this advantage functions differently for males and females. Furthermore, the studies demonstrate the importance of including contextual measures of acculturation into studies related to Hispanic adolescent sexual health.
Date: August 2016
Creator: Driver, Nichola D
Partner: UNT Libraries

Dissimilar Joining of Al (AA2139) – Mg (WE43) Alloys Using Friction Stir Welding

Description: This research demonstrates the use of friction stir welding (FSW) to join dissimilar (Al-Mg) metal alloys. The main challenges in joining different, dissimilar metal alloys is the formation of brittle intermetallic compounds (IMCs) in the stir zone affecting mechanical properties of joint significantly. In this present study, FSW joining process is used to join aluminum alloy AA2139 and magnesium alloy WE43. The 9.5 mm thick plates of AA2139 and WE43 were friction stir butt welded. Different processing parameters were used to optimize processing parameters. Also, various weldings showed a crack at interface due to formation of IMCs caused by liquation during FSW. A good strength sound weld was obtained using processing parameter of 1200 rev/min rotational speed; 76.2 mm/min traverse speed; 1.5 degree tilt and 0.13 mm offsets towards aluminum. The crack faded away as the tool was offset towards advancing side aluminum. Mostly, the research was focused on developing high strength joint through microstructural control to reduce IMCs thickness in Al-Mg dissimilar weld joint with optimized processing parameter and appropriate tool offset.
Date: December 2016
Creator: Poudel, Amir
Partner: UNT Libraries

Does Device Matter? Understanding How User, Device, and Usage Characteristics Influence Risky IT Behaviors of Individuals

Description: Over the past few years, there has been a skyrocketing growth in the use of mobile devices. Mobile devices are ushering in a new era of multi-platform media and a new paradigm of “being-always-connected”. The proliferation of mobile devices, the dramatic growth of cloud computing services, the availability of high-speed mobile internet, and the increase in the functionalities and network connectivity of mobile devices, have led to creation of a phenomenon called BYOD (Bring Your Own Device), which allows employees to connect their personal devices to corporate networks. BYOD is identified as one of the top ten technology trends in 2014 that can multiply the size of mobile workforce in organizations. However, it can also serve as a vehicle that transfers cyber security threats associated with personal mobile devices to the organizations. As BYOD opens the floodgates of various device types and platforms into organizations, identifying different sources of cyber security threats becomes indispensable. So far, there are no studies that investigated how user, device and usage characteristics affect individuals’ protective and risky IT behaviors. The goal of this dissertation is to expand the current literature in IS security by accounting for the roles of user, device, and usage characteristics in protective and risky IT behaviors of individuals. In this study, we extend the protection motivation theory by conceptualizing and measuring the risky IT behaviors of individuals and investigating how user, device, and usage characteristics along with the traditional protection motivation factors, influence individuals’ protective and risky IT behaviors. We collected data using an online survey. The results of our study show that individuals tend to engage in different levels of protective and risky IT behaviors on different types of devices. We also found that certain individual characteristics as well as the variety of applications that individuals use on their ...
Date: August 2015
Creator: Negahban, Arash
Partner: UNT Libraries

Dolores Dyer: Women's Basketball and the American Dream

Description: Dolores Dyer played from 1952-1953 for the Texas Cowgirls, a barnstorming women's basketball team that provided a form of entertainment popular throughout the United States in that era. The story of Dyer's life demonstrates how a woman could attempt to achieve the American dream—a major theme in American history—through success in athletic competition. Dyer's participation with the Texas Cowgirls also provides a look into the circumstances that limited women's participation in professional sport during the mid-twentieth century. Women's sports studies, although some are very thorough, have gaps in the research, and women's barnstorming basketball is one of the areas often overlooked. In light of this gap, this thesis relies on a variety of sources, including primary documents from unpublished collections, archived materials, and original oral histories from several members of the Texas Cowgirls team. This thesis contains analysis of the socioeconomic factors that influenced Dolores Dyer's maturation into a professional basketball player, examines what the American dream meant to her, and evaluates the extent to which she achieved it. Overall, it constructs a social history that can serve as a foundational source for further study of women in sports during the twentieth century.
Date: December 2012
Creator: Roberts, Jackie
Partner: UNT Libraries

Dynamic Behaviors of Historical Wrought Iron Truss Bridges – a Field Testing Case Study

Description: Civil infrastructure throughout the world serves as main arteries for commerce and transportation, commonly forming the backbone of many societies. Bridges have been and remain a crucial part of the success of these civil networks. However, the crucial elements have been built over centuries and have been subject to generations of use. Many current bridges have outlived their intended service life or have been retrofitted to carry additional loads over their original design. A large number of these historic bridges are still in everyday use and their condition needs to be monitored for public safety. Transportation infrastructure authorities have implemented various inspection and management programs throughout the world, mainly visual inspections. However, careful visual inspections can provide valuable information but it has limitations in that it provides no actual stress-strain information to determine structural soundness. Structural Health Monitoring (SHM) has been a growing area of research as officials need to asses and triage the aging infrastructure with methods that provide measurable response information to determine the health of the structure. A rapid improvement in technology has allowed researchers to start using new sensors and algorithms to understand the structural parameters of tested structures due to known and unknown loading scenarios. One of the most promising methods involves the use of wireless sensor nodes to measure structural responses to loads in real time. The structural responses can be processed to help understand the modal parameters, determine the health of the structure, and potentially identify damage. For example, modal parameters of structures are typically used when designing the lateral system of a structure. A better understanding of these parameters can lead to better and more efficient designs. Usually engineers rely on a finite element analysis to identify these parameters. By observing the actual parameters displayed during field testing, the theoretical FE models ...
Date: December 2015
Creator: Hedric, Andrew C.
Partner: UNT Libraries

Eaten: A Novel

Description: This novel operates on two levels. First, it is a story concerning the fate of a young woman named Raven Adams, who is prompted into journeying westward after witnessing what she believes to be an omen. On another level, however, the novel is intended to be a philosophical questioning of western modes of “science-based” singular conceptualizations of reality, which argue that there is only one “real world” and anyone who deviates from this is “crazy,” “stupid,” or “wrong.” Raven as a character sees the world in terms of what might be called “magical thinking” in modern psychology; her closest relationship is with a living embodiment of a story, the ancient philosopher Diogenes, which she believes is capable of possessing others and directing her journey. As the story continues the reader comes to understand Raven’s perceptions of her reality, leading to a conceptualization of reality as being “multi-layered.” Eventually these layers are collapsed and unified in the final chapters. The novel makes use of many reference points including philosophy, classical mythology, folklore, religion, and internet social media in order to guide the reader along Raven’s story.
Date: May 2016
Creator: Foster, Natalie
Partner: UNT Libraries

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.
Date: August 2017
Creator: Sanchez, Nydia C
Partner: UNT Libraries

Effect of Acute Alcohol Ingestion on Resistance Exercise Induced mTORC1 Signaling in Human Muscle

Description: The purpose of this project was to further elucidate the effects post-exercise alcohol ingestion. This project had many novel aspects including using a resistance exercise (RE) only exercise design and the inclusion of women. To our knowledge, we are the first to investigate the effect of post-RE alcohol ingestion in women. In the first chapter of this project, information on the prevalence of alcohol use and the importance of skeletal muscle as a dynamic and metabolic tissue was provided. In chapter two, the effects of post-RE alcohol ingestion in men and women are detailed. The major findings of this study was that although RE elicited similar mTORC1 signaling both in men and in women, alcohol ingestion appeared to only attenuate RE-induced phosphorylation of the mTORC1 signaling pathway in men. The third chapter focused on examining the effects of post-RE alcohol ingestion on acute testosterone bioavailability. The primary findings of this study was that alcohol substantially elevated serum total and free testosterone concentrations during recovery from a bout of resistance exercise. The fourth chapter detailed factors that contribute to bone density in men. The major findings of this study was that young adult male long-distance runners who participated in resistance training at least once per week had greater bone mineral density than their non-resistance trained and non-exercise trained peers.
Date: August 2015
Creator: Duplanty, Anthony A.
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.
Date: May 2015
Creator: Venable, Adam Steven
Partner: UNT Libraries

The Effect of Natural Gas Well Setback Distance on Drillable Land in the City of Denton, Texas

Description: Municipalities protect human health and environmental resources from impacts of urban natural gas drilling through setback distances; the regulation of distances between well sites and residences, freshwater wells, and other protected uses. Setback distances have increased over time, having the potential to alter the amount and geographical distribution of drillable land within a municipality, thereby having implications for future land use planning and increasing the potential for future incompatible land uses. This study geographically applies a range of setback distances to protected uses and freshwater wells in the city limits of Denton, Texas to investigate the effect on the amount of land remaining for future gas well development and production. Denton lies on the edge of a productive region of the Barnett Shale geological formation, coinciding with a large concentration of drillable land in the southwestern region of the study area. This region will have the greatest potential for impacts to future municipal development and land use planning as a result of future gas well development and higher setback standards. Given the relatively high acreage of drillable land in industrially zoned subcategory IC-G and the concern regarding gas well drilling in more populated areas, future drilling in IC-G, specifically in IC-G land cover classes mowed/grazed/agriculture and herbaceous, would have the least impact on residential uses and tree cover, as well as decreasing the potential for future incompatible land uses.
Date: May 2014
Creator: Daniel, Michael
Partner: UNT Libraries

Effect of Retting on Surface Chemistry and Mechanical Performance Interactions in Natural Fibers for High Performance Polymer Composites

Description: Sustainability through replacement of non-renewable fibers with renewable fibers is an ecological need. Impact of transportation costs from South-east Asia on the life cycle analysis of the composite is detrimental. Kenaf is an easily grown crop in America. Farm based processing involves placing the harvested crop in rivers and ponds, where retting of the fibers from the plant (separation into fibers) can take 2 weeks or more. The objective of this thesis is to analyze industrially viable processes for generating fibers and examine their synergistic impact on mechanical performance, surface topography and chemistry for functional composites. Comparison has been made with commercial and conventional retting process, including alkali retting, enzymatic retting, retting in river and pond water (retting occurs by natural microbial population) with controlled microbial retting. The resulting kenaf fibers were characterized by dynamic mechanical analysis (DMA), Raman spectroscopy (FT-Raman), Fourier transform infrared spectroscopy (FT-IR), polarized optical microscopy (POM), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) optical fluorescence microscopy, atomic force microscopy (AFM) and carbohydrate analysis. DMA results showed that pectinase and microbe treated fibers have superior viscoelastic properties compared to alkali retting. XPS, Raman, FT-IR and biochemical analysis indicated that the controlled microbial and pectinase retting was effective in removing pectin, hemicellulose and lignin. SEM, optical microscopy and AFM analysis showed the surface morphology and cross sectional architecture were preserved in pectinase retting. Experimental results showed that enzymatic retting at 48 hours and controlled microbial retting at 72 hours yield uniform and superior quality fibers compared to alkali and natural retting process. Controlled microbial retting is an inexpensive way to produce quality fibers for polymer composite reinforcement.
Date: May 2013
Creator: Ramesh, Dinesh
Partner: UNT Libraries

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.
Date: August 2017
Creator: Bandi, Raghava
Partner: UNT Libraries

Effect Size Reporting and Interpreting Practices in Published Higher Education Journal Articles

Description: Data-driven decision making is an integral part of higher education and it needs to be rooted in strong methodological and statistical practices. Key practices include the use and interpretation of effect sizes as well as a correct understanding of null hypothesis significance testing (NHST). Therefore, effect size reporting and interpreting practices in higher education journal articles represent an important area of inquiry. This study examined effect size reporting and interpretation practices of published quantitative studies in three core higher education journals: Journal of Higher Education, Review of Higher Education, and Research in Higher Education. The review covered a three-year publication period between 2013 and 2015. Over the three-year span, a total of 249 articles were published by the three journals. The number of articles published across the three years did not vary appreciably. The majority of studies employed quantitative methods (71.1%), about a quarter of them used qualitative methods (25.7%), and the remaining 3.2% used mixed methods. Seventy-three studies were removed from further analysis because they did not feature any quantitative analyses. The remaining 176 quantitative articles represented the sample pool. Overall, 52.8% of the 176 studies in the final analysis reported effect size measures as part of their major findings. Of the 93 articles reporting effect sizes, 91.4% of them interpreted effect sizes for their major findings. The majority of studies that interpreted effect sizes also provided a minimal level of interpretation (60.2% of the 91.4%). Additionally, 26.9% of articles provided average effect size interpretation, and the remaining 4.3% of studies provided strong interpretation and discussed their findings in light of previous studies in their field.
Date: August 2016
Creator: Stafford, Mehary T.
Partner: UNT Libraries

The Effectiveness of a Professional Learning Community on Student Achievement in Elementary Reading and Mathematics in a Large Urban School District

Description: The study was to determine the impact of a Professional Learning Community on student achievement as measured by the state's criterion referenced reading and mathematics achievement tests. Data for this study were extracted from the school district's student database. Two cohorts of 90 students each were randomly selected from a population of approximately 600 students in 3 schools that participated in a Professional Learning Community (treatment) and 3 schools that did not (control). Professional Learning Communities known as PLCs, can serve as a major theoretical framework to promote the improvement of classroom teachers' instructional practice, teacher effectiveness and student achievement. Reading and mathemtics mean scale scores were extracted at three time points (year 1, year 2, and year 3) across three grades (grade 3, grade 4 and grade 5). Test for equality of variance found that no statistically significant difference existed between the mean scale scores of the two cohorts at the beginning of the study. The findings revealed that both cohorts trend toward increased academic achievement from year to year individually; however, when compared to each other, no statistically significant difference existed. Further research is indicated to examine each PLC for implementation, support and leadership as they relate to the PLC and a focus on instruction and learning.
Date: May 2016
Creator: Landry, Jacqueline Hayles
Partner: UNT Libraries

Effectiveness of Fillers for Corrosion Protection of AISI-SAE 1018 Steel in Sea Salt Solution

Description: Corrosion represents the single most frequent cause for product replacement or loss of product functionality with a 5% coat to the industrial revenue generation of any country in this dissertation the efficacy of using filled coatings as a protection coating are investigated. Fillers disrupt the polymer-substrate coating interfacial area and lead to poor adhesion. Conflicting benefits of increasing surface hardness and corrosion with long term durability through loss of adhesion to the substrate are investigated. The effects of filler type, filler concentration and exposure to harsh environments such as supercritical carbon dioxide on salt water corrosion are systematically investigated. The constants maintained in the design of experiments were the substrate, AISI-SAE 1018 steel substrate, and the corrosive fluid synthetic sea salt solution (4.2 wt%) and the polymer, Bismaleimide (BMI). Adhesion strength through pull-off, lap shear and shear peel tests were determined. Corrosion using Tafel plots and electrochemical impedance spectroscopy was conducted. Vickers hardness was used to determine mechanical strength of the coatings. SEM and optical microscopy were used to examine dispersion and coating integrity. A comparison of fillers such as alumina, silica, hexagonal boron nitride, and organophilic montmorillonite clay (OMMT) at different concentrations revealed OMMT to be most effective with the least decrease in adhesion from filler-substrate contact. Subsequently examining filler concentration, a 3 wt% OMMT was found to be most effective. A comparison of unmodified and modified BMI with 3 wt% OMMT exposed and not exposed to supercritical carbon dioxide showed that the BMI provided better corrosion protection; however, OMMT provided better wear, shear, and hardness performance.
Date: May 2017
Creator: Al-Shenawa, Amaal Abdallah Ali
Partner: UNT Libraries

The Effects of Air Pollution on the Intestinal Microbiota: A Novel Approach to Assess How Gut Microbe Interactions with the Environment Affect Human Health

Description: This thesis investigates how air pollution, both natural and anthropogenic, affects changes in the proximal small intestine and ileum microbiota profile, as well as intestinal barrier integrity, histological changes, and inflammation. APO-E KO mice on a high fat diet were randomly selected to be exposed by whole body inhalation to either wood smoke (WS) or mixed vehicular exhaust (MVE), with filtered air (FA) acting as the control. Intestinal integrity and histology were assessed by observing expression of well- known structural components tight junction proteins (TJPs), matrix metallopeptidase-9 (MMP-9), and gel-forming mucin (MUC2), as well known inflammatory related factors: TNF-α, IL-1β, and toll-like receptor (TLR)-4. Bacterial profiling was done using DNA analysis of microbiota within the ileum, utilizing 16S metagenomics sequencing (Illumina miSeq) technique. Overall results of this experiment suggest that air pollution, both anthropogenic and natural, cause a breach in the intestinal barrier with an increase in inflammatory factors and a decrease in beneficial bacteria. This evidence suggests the possibility of air pollution being a potential causative agent of intestinal disease as well as a possible contributing mechanism for induction of systemic inflammation.
Date: May 2017
Creator: Fitch, Megan
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.
Date: May 2015
Creator: Luo, Bing
Partner: UNT Libraries

Effects of Brain Brain Injury on Primary Cilia of Glial Cells and Pericytes

Description: Glial cells maintain homeostasis that is essential to neuronal function. Injury to the nervous system leads to the activation and proliferation of glial cells and pericytes, which helps to wall off the damaged region and restore homeostatic conditions. Sonic hedgehog is a mitogen which is implicated in injury-induced proliferation of glial cells and pericytes. The mitogenic effects of sonic hedgehog require primary cilia, but the few reports on glial or pericyte primary cilia do not agree about their abundance and did not address effects of injury on these cilia. Primary cilia are microtubule-based organelles that arise from the centrosome and are retracted before cells divide. Depending on cell type, proteins concentrated in cilia can transduce several mitotic, chemosensory, or mechanosensory stimuli. The present study investigated effects of stab wound injury on the incidence and length of glial and pericyte primary cilia in the area adjacent to the injury core. Astrocytes, polydendrocytes and pericytes were classified by immunohistochemistry based on cell-type markers. In normal adult mice, Arl13b immunoreactive primary cilia were present in a majority of each cell type examined: astrocytes, 98±2%; polydendrocytes, 87±6%; and pericytes, 79±13% (mean ± SEM). Three days post-injury, cilium incidence decreased by 24% in astrocytes (p< 0.008) and 41% in polydendrocytes (p< 0.002), but there was no significant effect in pericytes. Polydendrocytes labeled with the cell cycle marker Ki67 were less likely to have cilia compared to resting, Ki67- polydendrocytes. Considering post-injury rates of proliferation for astrocytes and polydendrocytes, it appears that resorption of cilia due to cell cycle entry may account for much of the loss of cilia in polydendrocytes but was not sufficient to account for the loss of cilia in astrocytes. Under normal conditions, astrocytes rarely divide, and they maintain non-overlapping territories. However, three days after injury, there was a 7-fold increase in ...
Date: December 2016
Creator: Coronel, Marco Vinicio
Partner: UNT Libraries

Effects of Quantum Coherence and Interference

Description: Quantum coherence and interference (QCI) is a phenomenon that takes place in all multi-level atomic systems interacting with multiple lasers. In this work QCI is used to create several interesting effects like lasing without inversion (LWI), controlling group velocity of light to extreme values, controlling the direction of propagation through non-linear phase matching condition and for controlling the correlations in field fluctuations. Controlling group velocity of light is very interesting because of many novel applications it can offer. One of the unsolved problems in this area is to achieve a slow and fast light which can be tuned continuously as a function of frequency. We describe a method for creation of tunable slow and fast light by controlling intensity of incident laser fields using QCI effects. Lasers are not new to the modern world but an extreme ultra-violet laser or a x-ray laser is definitely one of the most desirable technologies today. Using QCI, we describe a method to realize lasing at high frequencies by creating lasing without inversion. Role of QCI in creating correlations and anti-correlations, which are generated by vacuum fluctuations, in a three level lambda system coupled to two strong fields is discussed.
Date: August 2013
Creator: Davuluri, Subrahmanya Bhima Sankar
Partner: UNT Libraries

Effects of Student-Created Question Process on Learning Biomedical Statistics in a Specialized Master's in Medical Sciences

Description: This study explored the effectiveness of a student question creation process engaging students actively in self, peer, and instructor interaction in development of affective, cognitive, and meta-cognitive skills. Employing a mixed-methods sequential explanatory design assigning both treatment and control activities sequentially in an alternating pattern over a six week period, students' performance on exams as well as their perceptions of various aspects of the student question creation process were used to evaluate the effectiveness of student-created questions (SCQs) activities as a cognitive strategy and to identify factors contributing to the effectiveness of question creation activities on students' learning. Subjects of this study were high performing and highly motivated graduate students in an 8-week online biomedical statistics course, part of a specialized master's program designed for medical school preparation. Survey findings and focus groups strongly supported the student question creation process as a facilitator of higher order thinking. However, the relatively short study duration, comparison of student question creation with another competing method for facilitating learning (discussion board) and not a pure control group, and availability of a common study guide course with student-created questions on all course topics may have muted assessment of the full impact of the strategy on learning. Although practically difficult in an education environment, further research to assess fully the impact of the student question creation strategy is desirable especially if these confounding factors can be greatly minimized, if not eliminated.
Date: May 2017
Creator: Bashet, Abuzafar
Partner: UNT Libraries

Effects of UE Speed on MIMO Channel Capacity in LTE

Description: With the introduction of 4G LTE, multiple new technologies were introduced. MIMO is one of the important technologies introduced with fourth generation. The main MIMO modes used in LTE are open loop and closed loop spatial multiplexing modes. This thesis develops an algorithm to calculate the threshold values of UE speed and SNR that is required to implement a switching algorithm which can switch between different MIMO modes for a UE based on the speed and channel conditions (CSI). Specifically, this thesis provides the values of UE speed and SNR at which we can get better results by switching between open loop and closed loop MIMO modes and then be scheduled in sub-channels accordingly. Thus, the results can be used effectively to get better channel capacity with less ISI. The main objectives of this thesis are: to determine the type of MIMO mode suitable for a UE with certain speed, to determine the effects of SNR on selection of MIMO modes, and to design and implement a scheduling algorithm to enhance channel capacity.
Date: August 2016
Creator: Shukla, Rahul
Partner: UNT Libraries