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Modern Forms of an Ancient Art: A Selection of Contemporary Fanfares for Multiple Trumpets Demonstrating Evolutionary Processes in the Fanfare Form (open access)

Modern Forms of an Ancient Art: A Selection of Contemporary Fanfares for Multiple Trumpets Demonstrating Evolutionary Processes in the Fanfare Form

The pieces discussed throughout this dissertation provide evidence of the evolution of the fanfare and the ability of the fanfare, as a form, to accept modern compositional techniques. While Britten’s Fanfare for St. Edmundsbury maintains the harmonic series, it does so by choice rather than by the necessity in earlier music played by the baroque trumpet. Stravinsky’s Fanfare from Agon applies set theory, modal harmonies, and open chords to blend modern techniques with medieval sounds. Satie’s Sonnerie makes use of counterpoint and a rather unusual, new characteristic for fanfares, soft dynamics. Ginastera’s Fanfare for Four Trumpets in C utilizes atonality and jazz harmonies while Stravinsky’s Fanfare for a New Theatre strictly coheres to twelve-tone serialism. McTee’s Fanfare for Trumpets applies half-step dissonance and ostinato patterns while Tower’s Fanfare for the Uncommon Woman demonstrates a multi-section work with chromaticism and tritones. By applying modern compositional techniques to an older, abstract form, composers have maintained the original aesthetic while allowing for fanfares to be used as concert music. This document adds to the limited body of scholarly writing on modern fanfares.
Date: May 2015
Creator: Florek, Paul J.
System: The UNT Digital Library
The Modern Trombone in the African American Church: Shout Bands and the African American Preacher in the United House of Prayer (open access)

The Modern Trombone in the African American Church: Shout Bands and the African American Preacher in the United House of Prayer

The United House of Prayer was established by Marcelino Manuel da Graça (1881-1960), who is also known as Charles Manuel “Sweet Daddy” Grace, or “Daddy” Grace. He founded and developed the use of the shout bands which are charismatic gospel trombone ensembles within this church. This study explores the importance of shout bands and examines them from multiple perspectives focusing in particular on worship practices. Additionally, it examines rhythmic elements as the most important characteristic of music performed by these unique ensembles, rhythms that reflect the preacher’s personal timing and inflections that the trombones then imitate. The approach used here supports a deeper understanding of the United House of Prayer and of the trombone in church services of this denomination. Indeed, it ultimately establishes the trombone’s role in the United House of Prayer.
Date: May 2015
Creator: Block, Tyrone J.
System: The UNT Digital Library
The Palestinian Archipelago and the Construction of Palestinian Identity After Sixty-five Years of Diaspora: the Rebirth of the Nation (open access)

The Palestinian Archipelago and the Construction of Palestinian Identity After Sixty-five Years of Diaspora: the Rebirth of the Nation

This dissertation conceptualizes a Palestinian archipelago based on Mikhail Bakhtin’s theory of the chronotope, and uses the archipelago model to illustrate the situation and development of Palestinian consciousness in diaspora. To gain insight into the personal lives of Palestinians in diaspora, This project highlights several islands of Palestinian identities as represented in the novels: Dancing Arabs, A Compass for the Sunflower, and The Inheritance. The identities of the characters in these works are organized according to the archipelago model, which illustrates how the characters rediscover, repress, or change their identities in order to accommodate life in diaspora. Analysis reveals that a major goal of Palestinian existence in diaspora is the maintenance of an authentic Palestinian identity. Therefore, my description of the characters’ identities and locations in the archipelago model are informed by various scholars and theories of nationalism. Moreover, this dissertation illustrates how different Palestinian identities coalesce into a single national consciousness that has been created and sustained by a collective experience of suffering and thirst for sense of belonging and community among Palestinians. Foremost in the memories of all Palestinians is the memory of the land of Palestine and the dream of national restoration; these are the main uniting …
Date: May 2015
Creator: Shaheen, Basima
System: The UNT Digital Library
Pathways for C—H Activation and Functionalization by Group 9 Metals (open access)

Pathways for C—H Activation and Functionalization by Group 9 Metals

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 …
Date: May 2015
Creator: Pahls, Dale R.
System: The UNT Digital Library
Patient Family and Hospital Staff Information Needs at a Pediatric Hospital: an Analysis of Information Requests Received by the Family Resource Libraries (open access)

Patient Family and Hospital Staff Information Needs at a Pediatric Hospital: an Analysis of Information Requests Received by the Family Resource Libraries

This research explored the information needs of patient families and hospital staff at a pediatric hospital system in Dallas, Texas. Library statistics recorded in four hospital libraries from 2011 - 2013 were used to analyze the information requests from patient families and hospital staff. Crosstabulations revealed the extent to which patient families and hospital staff used the libraries to satisfy their information needs. The data showed that patient families used the libraries very differently than hospital staff. Chi-square tests for independence were performed to identify the relationships between the Classification (Patient Family, Hospital Staff) and two descriptors of information needs (Request Type, Resources Used). There were a total of 1,406 information requests analyzed. The data showed that patient families and hospital staff information requests differed greatly in the number of information requests, the type of information requested, the resources used and the time the library staff spent on the requests. Chi-square analyses revealed relationships statistically significant at the p < .05 level; however, the strength of the relationships varied.
Date: May 2015
Creator: Rutledge, M. Hannah
System: The UNT Digital Library
Peer Networks and Health Risk Behaviors Among Adolescents (open access)

Peer Networks and Health Risk Behaviors Among Adolescents

Adolescence is a time of great exploration and change. During this time, youth are transitioning both biologically and sexually into adults. Adolescents are also testing the boundaries of self-reliance and making choices about their personal relationships. Not surprisingly, aggressive urges are often driven by peers in pursuit of some form of identity (Masten 2004). Peers can have both positive and negative effects on the wellbeing on youth. Peer groups can provide emotional, physical, and social support to youth during a time of immense change (Parker and Asher 1987; Gest, Graham-Berman, and Hartup 2001). Peers can also model delinquent and risk-taking behaviors that have lasting health, social, and economic consequences throughout the life course. In an effort to understand the role of friendships in adolescent health, social scientists have increasingly focused on adolescent network structures within schools and the role various positions and peer group formations influence behaviors such as alcohol and cigarette use, violent and serious delinquency, and sexual risk-taking. While informative, peer networks studies have yet to adequately address how peer network structures based on immigrant generation and types of marginalized social positions influence health risk behavior engagement among adolescents. In three studies, I address the dearth of research …
Date: May 2015
Creator: Niño, Michael David
System: The UNT Digital Library
A Performance Evaluation of Confidence Intervals for Ordinal Coefficient Alpha (open access)

A Performance Evaluation of Confidence Intervals for Ordinal Coefficient Alpha

Ordinal coefficient alpha is a newly derived non-parametric reliability estimate. As with any point estimate, ordinal coefficient alpha is merely an estimate of a population parameter and tends to vary from sample to sample. Researchers report the confidence interval to provide readers with the amount of precision obtained. Several methods with differing computational approaches exist for confidence interval estimation for alpha, including the Fisher, Feldt, Bonner, and Hakstian and Whalen (HW) techniques. Overall, coverage rates for the various methods were unacceptably low with the Fisher method as the highest performer at 62%. Because of the poor performance across all four confidence interval methods, a need exists to develop a method which works well for ordinal coefficient alpha.
Date: May 2015
Creator: Turner, Heather Jean
System: The UNT Digital Library
Plasma Interactions on Organosilicate Glass Dielectric Films and Emerging Amorphous Materials- Approach to Pore Sealing and Chemical Modifications (open access)

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

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 …
Date: May 2015
Creator: Kazi, Haseeb
System: The UNT Digital Library
Polyphonic Harmony in Three of Ferruccio Busoni’s Orchestral Elegies (open access)

Polyphonic Harmony in Three of Ferruccio Busoni’s Orchestral Elegies

This dissertation focuses on three of Busoni’s late orchestral works known as “orchestral elegies”: Berceuse élégiaque (Elegie no. 1, 1909), Gesang vom Reigen der Geister (Elegie no. 4, 1915), and Sarabande (Elegie no. 5, 1918-19). The study seeks to provide a better understanding of Busoni’s late style as a crucial bridge from late nineteenth-century chromaticism in the works of Liszt, Wagner, and others to the post-tonal languages of the twentieth century. At the heart of this study lies a particular concept that forms the basis of many characteristic features of Busoni’s late style, namely the concept of polyphonic harmony, or harmony as a cumulative result of independent melodic lines. This concept is also related to a technique of orchestration in which the collective harmony is sounded in such a way that the individual voices are distinct. In the highly personal tonal language of Busoni’s late works, passages often consist of a web of motives weaved throughout the voices at the surface level of the music. Linear analysis provides a means of unravelling the dense fabric of voices and illustrating the underlying harmonic progressions, which most often consist of parallel, primarily semitonal, progressions of tertian sonorities. Chapter 1 provides a backdrop …
Date: May 2015
Creator: Davis, Colin
System: The UNT Digital Library
Predicting Latino Male Student Retention: the Effect of Psychosocial Variables on Persistence for First-year College Students at a Southwest University (open access)

Predicting Latino Male Student Retention: the Effect of Psychosocial Variables on Persistence for First-year College Students at a Southwest University

The purpose of this study was to investigate and predict Latino male student retention using ACT’s Engage College survey at a research university in the southwestern region of the U.S. ACT’s Engage survey was designed to predict first-year college retention using 10 psychosocial measures. However, no empirical study exists to support ACT’s claim especially for Latino male students. Data from a four-year research university between 2009 and 2011 were analyzed with logistic regression. Logistic regression analysis was performed for the whole sample (N = 8,061) and for the Latino male subsample (n = 860). In the entire sample’s first regression model, high school grade quartile and SAT score as well as demographic variables were used as predictor variables. In this model, the independent variables of high school grade point average quartile, SAT score, gender, and race made statistically significant contributions to the model (Nagelkerke R2 = .031, p < .01). In the entire sample’s second regression model, ACT’s 10 psychosocial variables were added to the first regression model as predictor variables. Results indicated the instrument was valid for the freshmen as a whole because five out of 10 psychosocial measures displayed statistically significant odds ratios (ORs) for predicting retention: (a) …
Date: May 2015
Creator: McGuire, Melissa
System: The UNT Digital Library
A Predictive Model of Adolescent Persistence in Counseling (open access)

A Predictive Model of Adolescent Persistence in Counseling

Adolescence is a developmental period characterized by profound social and emotional changes. Counseling can serve as a protective factor for decreasing the long-term negative emotional effects. Despite this fact, counselors continue to struggle with high rates of attrition among adolescent clients. When examining trends of client persistence in counseling across the lifespan, researchers found a relationship between the presence of internalizing and externalizing behaviors. Additionally, they found that high levels of familial stress predicted premature termination from counseling. The purpose of the current study was to create a predictive model of adolescent persistence in counseling. I examined both personal and environmental characteristics of adolescents who sought counseling services (N = 72) from an on-campus university counseling clinic that serves as a training facility for master’s and doctoral students at an accredited counselor education program in the southwestern United States. Participants were predominantly White (67.6%, n = 50), with a mean age of 14.23 (SD = 1.65). Nearly 60% (n = 44) of the clients were female, and 37.8% were male (n = 28). Beyond descriptive variables, eight predictor variables were examined: adolescent involvement in their intake, time spent on the wait list, four domains of parental stress, and parent perceptions …
Date: May 2015
Creator: Holm, Jessica M.
System: The UNT Digital Library
The Procedural Generation of Interesting Sokoban Levels (open access)

The Procedural Generation of Interesting Sokoban Levels

As video games continue to become larger, more complex, and more costly to produce, research into methods to make game creation easier and faster becomes more valuable. One such research topic is procedural generation, which allows the computer to assist in the creation of content. This dissertation presents a new algorithm for the generation of Sokoban levels. Sokoban is a grid-based transport puzzle which is computational interesting due to being PSPACE-complete. Beyond just generating levels, the question of whether or not the levels created by this algorithm are interesting to human players is explored. A study was carried out comparing player attention while playing hand made levels versus their attention during procedurally generated levels. An auditory Stroop test was used to measure attention without disrupting play.
Date: May 2015
Creator: Taylor, Joshua
System: The UNT Digital Library
Professional Learning Community Dimensions in a North Texas Elementary School’s Culture and Their Impact on Reading and Math Student Growth Scores (open access)

Professional Learning Community Dimensions in a North Texas Elementary School’s Culture and Their Impact on Reading and Math Student Growth Scores

The purpose of this mixed methods study was to determine which dimensions, as represented by the Professional Learning Community Assessment – Revised dimensions, are present in the environment of North Texas elementary schools and their impact on student growth. A survey design was utilized in which elementary principals and teachers in a selected school district completed the Professional Learning Community – Revised survey developed by Hipp and Huffman (2009), to gather perceptions of PLC implementation within their school environments as well as reflect strengths and needs regarding each dimension. The results of the survey were analyzed and one-to-one interviews were completed to clarify and support survey results. Bivariate and multiple regression analysis were used to determine correlations between dimensions present in a school’s environment and their impact on student growth. The study found a statistically significant relationship between the dimensions of shared values and vision and shared personal practice and math growth. Although PLCA-R dimensions were not found to be statistically significant in predicting reading and math growth, the effect sizes were notable at 22.4% for reading growth and 15.8% for math growth. This study’s findings provide important information which educators can use to implement practical application of Professional Learning …
Date: May 2015
Creator: Patrick, Linda Denise
System: The UNT Digital Library
Prosperity Belief and Liberal Individualism: A Study of Economic and Social Attitudes in Guatemala (open access)

Prosperity Belief and Liberal Individualism: A Study of Economic and Social Attitudes in Guatemala

Globalization has facilitated the growth of “market-friendly” religions throughout the world, but especially in developing societies in the global South. A popular belief among these movements is prosperity belief. Prosperity belief has several characteristics which make it compatible with liberal individualism, the dominant value in a globalized society. At the same time, its compatibility with this value may be limited, extending only to economic liberalism, but not to liberal attitudes on social issues. Data from the Pew Forum on Religious and Public Life’s 2006 survey Spirit and Power: Survey of Pentecostals in Guatemala is used to conduct a quantitative analysis regarding the economic and social attitudes of prosperity belief adherents in Guatemala in order to examine the potential, as well as the limits, of this belief’s compatibility with liberal individualism. Results suggest that support for liberal individualism is bifurcated. On one hand there is some support for the positive influence of prosperity belief on economic liberalism in regards to matters of free trade, but on the other hand, prosperity belief adherents continue to maintain conservative attitudes in regards to social issues. As prosperity belief and liberal individualism continue to grow along global capitalism, these findings have implications for the future …
Date: May 2015
Creator: Huang, Lindsey A.
System: The UNT Digital Library
Refining the Definition and Detection of Response Styles: An Initial Examination of Defensiveness and Feigning on the Personality Inventory for DSM-5 (open access)

Refining the Definition and Detection of Response Styles: An Initial Examination of Defensiveness and Feigning on the Personality Inventory for DSM-5

The fifth edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM 5) presents an alternate model for personality disorders, blending categorical and dimensional assessment into a hybrid diagnostic procedure. Released concurrently, the Personality Inventory for DSM 5 (PID 5) measures the five domains and 25 facets that comprise the trait components of this hybrid model. However, the PID 5 currently lacks validity indicators to capture intentionally distorted responding. The current study investigated the susceptibility of the PID 5 to defensiveness and feigning among a large sample of undergraduate students. First, a detailed desirability analysis (N = 465) was conducted of the PID 5 items and response options. Responses from the study were used to create three desirability based validity scales. Next, in a between-subjects simulation design (N = 128), the effects of faking were explored at domain and facet levels. As a result, two symptom based validity scales were created. In a separate validation sample (N = 134), the five newly created validity scales were compared with the Paulhus Deception Scales for capturing both defensiveness and feigning. All five scales were evaluated for ruling out faking (i.e., identifying likely genuine respondents) and ruling in either defensiveness or feigning. …
Date: May 2015
Creator: Fiduccia, Chelsea E.
System: The UNT Digital Library
The Relationship of Peer Leadership Employment to Academic Outcomes in Texas Institutions of Higher Education (open access)

The Relationship of Peer Leadership Employment to Academic Outcomes in Texas Institutions of Higher Education

The purpose of this quantitative study was to examine the relationship of participation and involvement in an undergraduate student success program to academic success and persistence among students in three programs sponsored by the Texas Higher Education Coordinating Board (THECB): the G-Force Collegiate Work-Study Mentorship Program, the Advancement Via Individual Determination (AVID) for Higher Education (AHE) program, and the THECB work-study program. The sample was identified using data from the THECB during the 2009-2013 academic years. Compared to THECB work-study students, significantly more AHE and G-Force students persisted toward graduation while engaged in the program (p < .001). ANOVA indicated that AHE students had a higher average GPA compared to G-Force and THECB work-study students, controlled for gender, race/ethnicity, pre-program GPA, and length of time in the position. Regression analyses found no statistically significant relationship between program associations and persistence towards graduation or GPA. Results suggest that although participation in a peer leadership programs such as AHE and G-Force encourage greater academic achievement and persistence, there is no direct relation to the achievement of these outcome variables. Implications of the study suggest the need for a deeper analysis into elements of peer leadership programs that contribute to student success, an …
Date: May 2015
Creator: Buggs, Michelle L.
System: The UNT Digital Library
A Restorative Environmental Justice for the Prison Industrial Complex: a Transformative Feminist Theory of Justice (open access)

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

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.
Date: May 2015
Creator: Conrad, Sarah M.
System: The UNT Digital Library
SEM Predicting Success of Student Global Software Development Teams (open access)

SEM Predicting Success of Student Global Software Development Teams

The extensive use of global teams to develop software has prompted researchers to investigate various factors that can enhance a team’s performance. While a significant body of research exists on global software teams, previous research has not fully explored the interrelationships and collective impact of various factors on team performance. This study explored a model that added the characteristics of a team’s culture, ability, communication frequencies, response rates, and linguistic categories to a central framework of team performance. Data was collected from two student software development projects that occurred between teams located in the United States, Panama, and Turkey. The data was obtained through online surveys and recorded postings of team activities that occurred throughout the global software development projects. Partial least squares path modeling (PLS-PM) was chosen as the analytic technique to test the model and identify the most influential factors. Individual factors associated with response rates and linguistic characteristics proved to significantly affect a team’s activity related to grade on the project, group cohesion, and the number of messages received and sent. Moreover, an examination of possible latent homogeneous segments in the model supported the existence of differences among groups based on leadership style. Teams with assigned leaders …
Date: May 2015
Creator: Brooks, Ian Robert
System: The UNT Digital Library
(Some More) American Literature (open access)

(Some More) American Literature

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.
Date: May 2015
Creator: VandeZande, Zach
System: The UNT Digital Library
Sources of Organizational Resilience During the 2012 Korean Typhoons: an Institutional Collective Action Framework (open access)

Sources of Organizational Resilience During the 2012 Korean Typhoons: an Institutional Collective Action Framework

The objective of this proposed research is to test whether interorganizational collaboration contributes to the ability of an organization to bounce back swiftly from disasters. The research questions are examined from the Institutional Collective Action (ICA) perspective. The general argument of this dissertation is that organizational resilience can be explained by interorganizational collaboration. The ICA framework, specifically, identifies two general network structures to explain strategies that can be adopted to minimize collaboration risks: bonding and bridging structures. This dissertation focuses on how governmental and nongovernmental organizations in South Korea collaborated. The data was collected from the southeastern tip of the Korean Peninsula in August of 2012, and January of 2013. The 2012 Typhoons devastated the area after the first data set was collected in August 2012, causing the loss of estimated US$ 730 million and 29 fatalities. Afterward, the second survey was administrated in January of 2013 to gauge respondents’ views on how organizations responded to the disasters. This dissertation consists of three essays. The first essay presents a brief overview and assessment of the current research on resilience. The second essay empirically tests the sources of organization resilience. The third essay examines the dynamic nature of interorganizational ties by …
Date: May 2015
Creator: Jung, Kyujin
System: The UNT Digital Library
Sovereign Immunity: a Study of Higher Education Cases (open access)

Sovereign Immunity: a Study of Higher Education Cases

This study explored the legal parameters of sovereign immunity and its waivers for employees of public institutions of higher education in the state of Texas. This empirical study examined the decisions of the Texas Judiciary concerning public university litigation in the area of sovereign immunity, with a review of major state court decisions. Legal research methodology was used in this study. The data for this study included case study review of six cases decided by the Texas judiciary. Information about each of the cases and the important legal inferences from the cases was discussed. A review of the history of sovereign immunity and the current status of the application of the Texas Tort Claims Act was also included. Based on the review of the relevant case law and scholarly commentary, the study findings suggest that a) Texas courts recognize and apply the doctrine of sovereign immunity, unless the application of the doctrine is restricted by the Texas Tort Claims Act; b) the Texas Tort Claims Act establishes limited waivers to sovereign immunity applicable only under specified circumstances and subjects; c) Texas courts were consistent in applying the circumstances by which an institution or its actors waived sovereign immunity. Practice recommendations …
Date: May 2015
Creator: Mancone, Nichole A.
System: The UNT Digital Library
Space and Spectrum Engineered High Frequency Components and Circuits (open access)

Space and Spectrum Engineered High Frequency Components and Circuits

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 …
Date: May 2015
Creator: Arigong, Bayaner
System: The UNT Digital Library
Stress Response by Alternative σ-factor, RpoH, and Analysis of Posttranslational Modification of the Heat Shock Protein, Dnak, in Escherichia coli (open access)

Stress Response by Alternative σ-factor, RpoH, and Analysis of Posttranslational Modification of the Heat Shock Protein, Dnak, in Escherichia coli

Bacteria have developed specialized responses that involve the expression of particular genes present in a given regulon. Sigma factors provide regulatory mechanisms to respond to stress by acting as transcriptional initiation factors. This work focuses on σ32 during oxidative stress in Escherichia coli. The differential response of key heat shock (HS) genes was investigated during HS and oxidative stress using qPCR techniques. While groEL and dnaJ experienced increases in transcriptional response to H2O2 (10 mM), HS (42°C), and paraquat (50 mM) exposure, the abundance of dnaK over the co-chaperones was apparent. It was hypothesized that DnaK undergoes oxidative modification by reactive carbonyls at its Lys-rich C-terminus, accounting for the differential response during oxidative stress. A σ32-mediated β-galactosidase reporter was devised to detect the activity of wild-type DnaK and DnaKV634X modified to lack the Lys-rich C-terminus. Under unstressed conditions and HS, σ32 was bound at the same rate in both strains. When subjected to H2O2, the WT DnaK strain produced significantly higher β-galactosidase than DnaKV634X (one-tailed Student’s t test p=0.000002, α=0.05) and approached the same level of output as the lacZ positive control. The β-galactosidase assay indicates that DnaK undergoes Lys modification in the WT strain, preventing the protein from binding …
Date: May 2015
Creator: Martinez, Sarah N.
System: The UNT Digital Library
Student Teachers’ Changing Confidence in Teaching (open access)

Student Teachers’ Changing Confidence in Teaching

Research shows that student teachers find the mentor teacher and the student teaching experience itself the two most influential factors in their practicum experience. This study examined five student teachers and the two mentor teachers of each in elementary school settings within a metropolitan school district in North Texas. Lave and Wenger’s (1991, 2002) community of practice theory informed this study. Data sources included mentor teacher interviews, student teacher interviews, student teacher observations, student teacher/mentor teacher dialogue journals, and student teacher reflections. A collective case study approach was followed to gain a detailed understanding of the experiences of the five student teachers, looking specifically at their confidence in teaching and the factors associated with it. Findings indicated that the confidence in teaching of all five student teachers changed throughout their practicum experiences. Results suggested many factors influenced these changes. Student teachers shared that the student teaching experience, the grade level/subjects taught, their relationships with their students, and their relationships with their mentor teachers contributed to their confidence. The mentor teachers perceived that student teachers’ confidence could be influenced by consistency in classroom management and their interactions with their mentor teachers. Two areas of influence on student teacher confidence not uncovered …
Date: May 2015
Creator: Stearns, Catherine L.
System: The UNT Digital Library