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Effects of Heart-Rate Variability Biofeedback Training and Emotional Regulation on Music Performance Anxiety in University Students (open access)

Effects of Heart-Rate Variability Biofeedback Training and Emotional Regulation on Music Performance Anxiety in University Students

Student musicians were recruited to participate in an experimental repeated measures research design study to identify effects of heart rate variability (HRV) biofeedback training and emotional self-regulation techniques, as recommended by HeartMath® Institute, on music performance anxiety (MPA) and music performance. Fourteen students were randomly assigned to a treatment or control group following a 5 minute unaccompanied baseline performance. Treatment group participants received 4-5 HRV training sessions of 30-50 minutes each. Training included bibliotherapy, using the computerized Freeze-Framer® 2.0 interactive training software, instruction in the Freeze-Frame® and Quick Coherence® techniques of emotional regulation, and also use of an emWave® portable heart rate variability training device for home training. Measures included the State-Trait Anxiety Inventory (STAI), Performance Anxiety Inventory (PAI), Flow State Scale (FSS), average heart rate (HR), and heart rate variability (HRV). Quade's rank transformed ANCOVA was used to evaluate treatment and no-treatment group comparisons. Combined MPA scores showed statistical significance at p=.05 level with large effect size of eta2=.320. Individual measurements of trait anxiety showed a small effect size of eta2=.001. State anxiety measurement showed statistical significance at the p=.10 level with a large effect size eta2=.291. FSS showed no statistical or effect size difference. PAI showed no statistical …
Date: December 2006
Creator: Thurber, Myron Ross
System: The UNT Digital Library
The Effects of Labeling and Stigma on the Social Rejection of Striptease Performers (open access)

The Effects of Labeling and Stigma on the Social Rejection of Striptease Performers

This study uses survey data collected from a convenience sample of undergraduate students (N=89). A vignette survey design is employed to measure social rejection of striptease performers compared to a control group. Data is also collected on negative stereotypes held about striptease performers, which are correlated with social rejection. Link and Phelan's conceptualization of the stigma process provides the theoretical framework for this analysis. Findings suggest that striptease performers experience higher levels of social rejection and are perceived more negatively than the control group and that endorsement of negative stereotypes is associated with social rejection.
Date: December 2006
Creator: Ebeid, Omar Randi
System: The UNT Digital Library
The Effects of Team Dynamics Training on Conceptual Data Modeling Task Performance (open access)

The Effects of Team Dynamics Training on Conceptual Data Modeling Task Performance

Database modeling is a complex conceptual topic often taught through the use of project-based teams. One of the problems with the use of project-based teams in university courses is the determination of whether this is the most effective use of instructor and student time involvement and effort level. Therefore, this study investigated the impact of providing team dynamics training prior to the commencement of short-duration project-based team conceptual data modeling projects on individual data modeling task performance (DMTP) outcomes and team cohesiveness. The literature review encompassed conceptual data design modeling, the use of a project-based team approach, team dynamics and cohesion, self-efficacy, gender, and diversity. The research population consisted of 75 university students at a North American University (Canadian) pursuing a business program requiring an information systems course in which database design components are taught. Analysis of the collected data revealed that there was a statistically significant inverse relationship found between the provision of team dynamics training and individual DMTP. However, no statistically significant relationship was found between team dynamics training and team cohesion. Therefore, this study calls into question the value of team dynamics training on learning outcomes in the case of very short duration project-based teams involved in …
Date: December 2006
Creator: Menking, Ricky Arnold
System: The UNT Digital Library
The Effects of Tests and Praise on Children's Hear-write and See-say Responses. (open access)

The Effects of Tests and Praise on Children's Hear-write and See-say Responses.

Four elementary school children were tested on 120 words containing the short e (e.g., ten, pen) and short a (e.g., tan, pan) sounds. Words were tested in the hear-write (H/W) and see-say (S/S) channels. No programmed consequences were scheduled during baseline (BL) tests 1-3. After BL, an error analysis categorized words based on channel error and topography of error. Praise was delivered during tests 4-6 for correct responses. Children's responses were variable within channel and across channels for a majority of words. By the end of the praise phase, there was a decrease in the number of words with errors, for all children in their error word group. Error topographies began to stabilize for some words during praise.
Date: December 2006
Creator: Edwards, Bobbie
System: The UNT Digital Library
The Effects of Trade Liberalization Policies on Human Development in Selected Least Developed Countries (open access)

The Effects of Trade Liberalization Policies on Human Development in Selected Least Developed Countries

This dissertation examines the effects of trade liberalization policies (represented by membership in the General Agreement on Tariffs and Trade/World Trade Organization on selected Least Developed Countries' (LDCs) human development (represented by the Human Development Index). In this dissertation, General Agreement on Tariffs and Trade (GATT) and World Trade Organization (WTO) policies are theorized to have two distinct types of effects: their direct effect and their indirect effect. Two questions are focused on: first, what is the effect (total, direct and indirect) of WTO policies on human development for selected LDCs? Second, what is the effect (total, direct and indirect) of WTO policies on human development for selected developing/developed countries (i.e. non-LDCs) holding economic development constant? Using the dependency theory of development as a theoretical basis, this dissertation examines the assumptions of modernization-theory-based policies as expressed in trade liberalization policies (i.e. the implementation of comparative advantage and now market fundamentalism) with world-system analysis techniques. To examine these questions, four panel regression models are constructed to measure the total, direct and indirect effects of WTO policies during the near-term (1998-2003) and during a longer historical term (1975-2000). The data for the analyses are taken from seven different sources of international data. …
Date: December 2006
Creator: Ray, Elizabeth Thompson
System: The UNT Digital Library
Effects of Training Accurate Component Strokes Using Response Constraint and Self-evaluation on Whole Letter Writing. (open access)

Effects of Training Accurate Component Strokes Using Response Constraint and Self-evaluation on Whole Letter Writing.

This study analyzed the effects of a training package containing response constraint, self-evaluation, reinforcement, and a fading procedure on written letter components and whole letter writing in four elementary school participants. The effect on accuracy of written components was evaluated using a multiple-baseline-across components and a continuous probe design of components, as well as pre-test, baseline, and post-test measures. The results of this study show that response constraint and self-evaluation quickly improved students' performance in writing components. Fading of the intervention was achieved quickly and performance maintained. Results also show that improvement in component writing improved whole letter and full name writing and letter reversals in the presence of a model were corrected.
Date: December 2006
Creator: Cline, Tammy Lynn
System: The UNT Digital Library
The Effects of Using Children's Literature with Adolescents in the English As a Foreign Language Classroom. (open access)

The Effects of Using Children's Literature with Adolescents in the English As a Foreign Language Classroom.

This study provides quantitative and qualitative data about the effects of using children's literature with adolescents in a language classroom and the role of children's literature in students' second/foreign language development, including listening, speaking, reading, and writing skills. The study presents qualitative data about the role of children's literature in developing more positive attitudes toward reading in the second/foreign language and toward reading in general. With literature being a model of a culture, presenting linguistic benefits for language learners, teaching communication, and being a motivator in language learning, this study presents empirical data that show that inclusion of children's literature in adolescents' second/foreign language classroom promotes appreciation and enjoyment of literature, enhances the development of language skills, stimulates more advanced learning, and promotes students' personal growth.
Date: December 2006
Creator: Belsky, Stella
System: The UNT Digital Library
The Efficacy of Equine Assisted Group Counseling with At-Risk Children and Adolescents (open access)

The Efficacy of Equine Assisted Group Counseling with At-Risk Children and Adolescents

The purpose of this study was to determine the efficacy of equine assisted group counseling as compared to in-school curriculum group guidance/counseling. Research examined externalizing, internalizing, maladaptive, and adaptive behaviors of elementary and middle school students who were considered at-risk of academic or social failure. Two types of behavior instruments, the Behavioral Assessment System for Children (BASC)-Self-Rating, Parent-Rating, and Teacher-Rating Scales; and the Animal Assisted Therapy-Psychosocial Session Form (AAT-PSF), were used in a pretest-posttest comparison group quasi experimental design. Results of the paired sample t-test analysis of the BASC Self-Report indicated that the equine assisted counseling group showed statistically significant improvement in five behavior areas, and the in-school curriculum group guidance/counseling group showed statistically significant improvement in four areas, with only one behavior area the same as the equine assisted counseling group. Results of the paired sample t-test analysis of the BASC Parent-Report indicated that the equine assisted counseling group showed statistically significant improvement in twelve behavior areas, whereas the in-school curriculum group guidance/counseling showed statistically significant improvement in only one behavior area. Results of the paired sample t-test analysis of the BASC Teacher-Report indicated that the equine assisted counseling group showed no statistically significant improvement; however the in-school curriculum …
Date: December 2006
Creator: Trotter, Kay Sudekum
System: The UNT Digital Library

Electrochemical Synthesis and Characterization of Inorganic Materials from Aqueous Solutions

Access: Use of this item is restricted to the UNT Community
The dissertation consists of the following three sections: 1. Hydroxyapatite (HA) coatings. In this work, we deposited HA precursor films from weak basic electrolytic solution (pH= 8-9) via an electrochemical approach; the deposits were changed into crystallite coatings of hydroxyapatite by sintering at specific temperatures (600-800 ºC). The formed coatings were mainly characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). XRD patterns show well-defined peaks of HA when sintered under vacuum conditions. FTIR measurements indicate the existence of hydroxyl groups, which were confirmed by the characteristic intensity of the stretching and bending bands at ~3575 and ~630 cm-1, respectively. The SEM shows an adhesive, crack free morphology for the double-layer coating surface of the samples sintered in a vacuum furnace. 2. Silver/polymer/clay nanocomposites. Silver nanoparticles were prepared in layered clay mineral (montmorillonite)/polymer (PVP: poly (vinyl pyrrolidone)) suspension by an electrochemical approach. The silver particles formed in the bulk suspension were stabilized by the PVP and partially exfoliated clay platelets, which acted as protective colloids to prevent coagulation of silver nanoparticles together. The synthesized silver nanoparticles/montmorillonite/PVP composite was characterized and identified by XRD, SEM, and TEM (transmission electron microscopy) measurements. 3. Ce-doped lead …
Date: December 2006
Creator: Yuan, Qiuhua
System: The UNT Digital Library
Energy-Aware Time Synchronization in Wireless Sensor Networks (open access)

Energy-Aware Time Synchronization in Wireless Sensor Networks

I present a time synchronization algorithm for wireless sensor networks that aims to conserve sensor battery power. The proposed method creates a hierarchical tree by flooding the sensor network from a designated source point. It then uses a hybrid algorithm derived from the timing-sync protocol for sensor networks (TSPN) and the reference broadcast synchronization method (RBS) to periodically synchronize sensor clocks by minimizing energy consumption. In multi-hop ad-hoc networks, a depleted sensor will drop information from all other sensors that route data through it, decreasing the physical area being monitored by the network. The proposed method uses several techniques and thresholds to maintain network connectivity. A new root sensor is chosen when the current one's battery power decreases to a designated value. I implement this new synchronization technique using Matlab and show that it can provide significant power savings over both TPSN and RBS.
Date: December 2006
Creator: Saravanos, Yanos
System: The UNT Digital Library
Enhanced learning performance in the middle school classroom through increased student motivation, by the use of educational software and question-based gaming technology. (open access)

Enhanced learning performance in the middle school classroom through increased student motivation, by the use of educational software and question-based gaming technology.

The purpose of this research was to determine if the introduction of a competitive and collaborative computer-based gaming software system into middle school classrooms would result in improved attendance and grades, and motivate students to have a greater interest in their studies. This study was conducted over a 6 week period, with attendance and performance data being collected from 284 students. Two quantitative surveys were used to measure course interest and motivation: (a) the Course Interest Survey (CIS), and (b) the Instructional Materials Motivation Survey (IMMS). Participation in these surveys consisted of 84 students taking the CIS and 40 students taking the IMMS. The results indicated that the experimental group showed statistically better scores than the comparison group in attendance and performance. Students participating in the experimental group had significantly lower mean ranks of absenteeism compared to students in the comparison group. Results also revealed significant differences on grades. Students that were in the experimental group had significantly higher grades compared to students that were in the comparison group. Results of the CIS suggest that a statistically significant difference does not exist on Attention, Relevance, Confidence, and Satisfaction between the experimental and comparison groups. Results of the means and standard …
Date: December 2006
Creator: Dorr, David L.
System: The UNT Digital Library
The evaluation, development, and application of the correlation consistent basis sets. (open access)

The evaluation, development, and application of the correlation consistent basis sets.

Employing correlation consistent basis sets coupled with electronic structure methods has enabled accurate predictions of chemical properties for second- and third-row main group and transition metal molecular species. For third-row (Ga-Kr) molecules, the performance of the correlation consistent basis sets (cc-pVnZ, n=D, T, Q, 5) for computing energetic (e.g., atomization energies, ionization energies, electron and proton affinities) and structural properties using the ab initio coupled cluster method including single, double, and quasiperturbative triple excitations [CCSD(T)] and the B3LYP density functional method was examined. The impact of relativistic corrections on these molecular properties was determined utilizing the Douglas-Kroll (cc-pVnZ-DK) and pseudopotential (cc-pVnZ-PP) forms of the correlation consistent basis sets. This work was extended to the characterization of molecular properties of novel chemically bonded krypton species, including HKrCl, FKrCF3, FKrSiF3, FKrGeF3, FKrCCF, and FKrCCKrF, and provided the first evidence of krypton bonding to germanium and the first di-krypton system. For second-row (Al-Ar) species, the construction of the core-valence correlation consistent basis sets, cc-pCVnZ was reexamined, and a revised series, cc-pCV(n+d)Z, was developed as a complement to the augmented tight-d valence series, cc-pV(n+d)Z. Benchmark calculations were performed to show the utility of these new sets for second-row species. Finally, the correlation consistent basis …
Date: December 2006
Creator: Yockel, Scott
System: The UNT Digital Library

Evaluation of dynamic and static electrical characteristics for the DY8 and YI8 process gallium diodes in comparison to the DI8 process boron diodes.

Access: Use of this item is restricted to the UNT Community
A rectifier is an electrical device, comprising one or more semiconductor devices arranged for converting alternating current to direct current by blocking the negative or positive portion of the waveform. The purpose of this study would be to evaluate dynamic and static electrical characteristics of rectifier chips fabricated with (a) DY8 process and (b) YI8 process and compare them with the existing DI8 process rectifiers. These new rectifiers were tested to compare their performance to meet or exceed requirements of lower forward voltages, leakage currents, reverse recovery time, and greater sustainability at higher temperatures compared to diodes manufactured using boron as base (DI8 process diodes) for similar input variables.
Date: December 2006
Creator: Dhoopati, Swathi
System: The UNT Digital Library
Explaining Juvenile Delinquency: A Test of Robert Agnew's General Strain Theory, Utilizing the National Longitudinal Study of Adolescent Health Data (open access)

Explaining Juvenile Delinquency: A Test of Robert Agnew's General Strain Theory, Utilizing the National Longitudinal Study of Adolescent Health Data

Strain theory has a long academic lineage for explaining criminal and deviant behavior from the classical writings of Emile Durkheim to the contemporary writings of Robert Agnew. The purpose of this research is to conduct an empirical test of Agnew's general strain theory utilizing Wave 1 data from the 1994-1996 National Longitudinal Study of Adolescent Health data (Add Health) (N = 6,503). Utilizing the Add Health data set represents a new attempt at empirically evaluating Agnew's theory. Scales were constructed by the author operationalizing the propositions of general strain theory utilizing variables from this data set. Regression was used to find out if juvenile delinquency is associated with Agnew's general strain theory. Research findings show that taken together, the propositions of general strain theory, cumulative measures of failure to achieve goals, loss of valued objects and introduction of stressful events are all statistically significant predictors of juvenile delinquency. Regression and scale correlations indicated a low positive relationship between juvenile delinquency and Agnew's general strain theory propositions. This study represents an attempt in utilizing a data set which has not been used before to empirically test general strain theory.
Date: December 2006
Creator: Gullion, John Gregory
System: The UNT Digital Library
Exploring Thai EFL University Students' Awareness of Their Knowledge, Use, and Control of Strategies in Reading and Writing (open access)

Exploring Thai EFL University Students' Awareness of Their Knowledge, Use, and Control of Strategies in Reading and Writing

The purpose of this research was to conduct case studies to explore and describe Thai university students' awareness and application of cognitive and metacognitive strategies when reading and writing in English-as-a-foreign-language (EFL). Four participants, including two high and two low English language proficiency learners, were selected from 14 students enrolled in a five-week course called English for Social Sciences offered at Kasetsart University in Bangkok, Thailand in 2005. The major sources of data for the analyses included the transcripts of the participants' pair discussions, think-aloud protocols, interviews, and daily journal entries. In addition, field work observations, reading and writing strategy checklists, participants' written work, and the comparison of the pretest and posttest results were also instrumental to the analyses. The interpretive approach of content analysis was employed for these four case studies. Findings were initially derived from the single-case analyses, and then from cross-case analyses. Major findings revealed that strategic knowledge enhanced these English-as-a-foreign- language (EFL) learners' proficiency in English reading and writing. However, applying elaborative strategies for higher-level reading was challenging for most of the participants. Two crucial factors that impeded their development were the learners' uncertain procedural and conditional knowledge of strategy uses and their limited English language …
Date: December 2006
Creator: Tapinta, Pataraporn
System: The UNT Digital Library

Extemporizing Reawakened: Saxophonist Branford Marsalis's Approach to the Cadenza for Concertino da Camera for Alto Saxophone and Eleven Instruments by Jacques Ibert

Access: Use of this item is restricted to the UNT Community
Whether provided by a composer, written out by a performer or completely improvised, the cadenza became a vehicle for performers' creativity, lyricism and technical prowess in the eighteenth and nineteenth centuries. The debate about whether to notate or improvise cadenzas, a question as old as the cadenza itself, continues today. Saxophonists have not been involved in this debate, since the instrument is a product of the mid-nineteenth century and was in its infancy just as the practice of improvising cadenzas was fading. This study documents an unprecedented, recently-recorded, improvised cadenza in one of the most significant twentieth-century saxophone works: Jacques Ibert's Concertino da Camera for Alto Saxophone and Eleven Instruments (1935). Saxophonist Branford Marsalis's neo-cadenza for Ibert's composition presents an aggregate of the twenty-first-century performer improvising a cadenza to a twentieth-century work, in a tradition that was common centuries ago. The document begins with an inquiry into improvised cadenzas, and proceeds to an examination of the performance history of the cadenza for the Concertino da Camera. Twenty professionally-recorded versions of the cadenza are presented in order to understand the performance history of the cadenza, and to place the Marsalis cadenza into context. This research culminates in a transcription and analysis …
Date: December 2006
Creator: James, Matthew T.
System: The UNT Digital Library
Family Influences on Young Adult Career Development and Aspirations (open access)

Family Influences on Young Adult Career Development and Aspirations

The purpose of this study was to examine family influences on career development and aspirations of young adults. Theories and research have examined the influence parents have on children's career development, but because of the multiple factors that influence career choices, understanding the family's influence is complex. The current study utilized ideas from self-determination, attachment, and career development theories to develop a framework for understanding how families influence young adult career development and aspirations. Rather than directly influencing career decisions, the family was proposed to influence processes within individuals that directly influence successful career development. This study used hierarchical regression analyses to test whether different aspects of family relationships and the family environment affect processes within young people, which in turn influence career development. A sample of 99 female and 34 male undergraduate students between 18 and 20 (mean age 18.67) completed questionnaires. Results support the idea that different aspects of the family influence diverse factors of career development and future aspirations. The achievement orientation of the family was predictive of career salience and extrinsic aspirations. Conflict with mothers was predictive of career salience, yet support and depth in the relationship with mothers and low amounts of conflict in the …
Date: December 2006
Creator: Bergen, Rebecca June-Schapeler
System: The UNT Digital Library
The Feminine Ancestral Footsteps: Symbolic Language Between Women in The Scarlet Letter and The House of the Seven Gables (open access)

The Feminine Ancestral Footsteps: Symbolic Language Between Women in The Scarlet Letter and The House of the Seven Gables

This study examines Hawthorne's use of symbols, particularly flowers, in The Scarlet Letter and The House of the Seven Gables. Romantic ideals stressed the full development of the self¬reliant individual, and romantic writers such as Hawthorne believed the individual would fully develop not only spiritually, but also intellectually by taking instruction from the natural world. Hawthorne's heroines reach their full potential as independent women in two steps: they first work together to defeat powerful patriarchies, and they then learn to read natural symbols to cultivate their artistic sensibilities which lead them to a full development of their intellect and spirituality. The focus of this study is Hawthorne's narrative strategy; how the author uses symbols as a language his heroines use to communicate from one generation to the next. In The Scarlet Letter, for instance, the symbol of a rose connects three generations of feminine reformers, Ann Hutchinson, Hester Prynne, and Pearl. By the end of the novel, Pearl interprets a rose as a symbol of her maternal line, which links her back to Ann Hutchinson. Similarly in The House of the Seven Gables Alice, Hepzibah, and Phoebe Pyncheon are part of a family line of women who work together to …
Date: December 2006
Creator: Serrano, Gabriela
System: The UNT Digital Library
First search at CDF for the Higgs boson decaying to a W-boson pair in proton-antiproton collisions at the center-of-mass energy of 1.96 TeV (open access)

First search at CDF for the Higgs boson decaying to a W-boson pair in proton-antiproton collisions at the center-of-mass energy of 1.96 TeV

By way of retaining the gauge invariance of the Standard Model (SM) and giving masses to the W{sup {+-}} and Z{sup 0} bosons and the fermions, the Higgs mechanism predicts the existence of a neutral scalar bosonic particle, whose mass is not exactly known. The Higgs boson is the only experimentally unconfirmed SM particle to date. This thesis documents a search for the Higgs boson in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron, using 360 {+-} pb {sup -1} data collected by the Run II Collider Detector at Fermilab (CDF II), as part of the most important quest for contemporary particle physicists. The search was for a Higgs boson decaying to a pair of W{sup {+-}} bosons, where each W boson decays to an electron, a muon or a tau that further decays to an electron or a muon with associated neutrinos. Events with two charged leptons plus large missing energy were selected in data triggered on a high p{sub t} lepton and compared to the signal and backgrounds modeled using Monte Carlo and jet data. No signal-like excess was observed in data. Therefore, upper limits on the HWW production cross-section in the analyzed mass range …
Date: December 1, 2006
Creator: Chuang, Shan-Huei S.
System: The UNT Digital Library
Foucault's Foundationless Democratic Theory (open access)

Foucault's Foundationless Democratic Theory

I examine a key shift in Michel Foucault's political philosophy from a position in which he was a staunch anti-humanist, to a final position in which he advocated not only the ability of the subject to influence his political condition, but also the individual freedoms assured by a democratic form of government. I begin by summarizing his overall critique of the post-Enlightenment West, and then explain how his observation of the Iranian Revolution served as a key turning point concerning his attitude towards the subject. Next, I elaborate on the direction of Foucault's late writings and examine how his new conceptualization of the subject leads him to embrace a democratic political system albeit free from Enlightenment philosophical foundations. I conclude by critiquing Foucault's foundationless democratic theory on the basis that it would ultimately undermine the individual freedoms and aesthetic development that he seeks to protect.
Date: December 2006
Creator: Carter, Kelly A.
System: The UNT Digital Library
A Framework of Automatic Subject Term Assignment: An Indexing Conception-Based Approach (open access)

A Framework of Automatic Subject Term Assignment: An Indexing Conception-Based Approach

The purpose of dissertation is to examine whether the understandings of subject indexing processes conducted by human indexers have a positive impact on the effectiveness of automatic subject term assignment through text categorization (TC). More specifically, human indexers' subject indexing approaches or conceptions in conjunction with semantic sources were explored in the context of a typical scientific journal article data set. Based on the premise that subject indexing approaches or conceptions with semantic sources are important for automatic subject term assignment through TC, this study proposed an indexing conception-based framework. For the purpose of this study, three hypotheses were tested: 1) the effectiveness of semantic sources, 2) the effectiveness of an indexing conception-based framework, and 3) the effectiveness of each of three indexing conception-based approaches (the content-oriented, the document-oriented, and the domain-oriented approaches). The experiments were conducted using a support vector machine implementation in WEKA (Witten, & Frank, 2000). The experiment results pointed out that cited works, source title, and title were as effective as the full text, while keyword was found more effective than the full text. In addition, the findings showed that an indexing conception-based framework was more effective than the full text. Especially, the content-oriented and the …
Date: December 2006
Creator: Chung, EunKyung
System: The UNT Digital Library
Function of the ENOD8 gene in nodules of Medicago truncatula. (open access)

Function of the ENOD8 gene in nodules of Medicago truncatula.

To elaborate on the function(s) of the ENOD8 gene in the nodules of M. truncatula, several different experimental approaches were used. A census of the ENOD8 genes was first completed indicating that only ENOD8.1 (nt10554-12564 of GenBank AF463407) is highly expressed in nodule tissues. A maltose binding protein-ENOD8 fusion protein was made with an E. coli recombinant system. A variety of biochemical assays were undertaken with the MBP-ENOD8 recombinant protein expressed in E. coli, which did not yield the esterase activity observed for ENOD8 protein nodule fractions purified from M. sativa, tested on general esterase substrates, α-naphthyl acetate, and p-nitrophenylacetate. Attempts were also made to express ENOD8 in a Pichia pastoris system; no ENOD8 protein could be detected from Pichia pastoris strains which were transformed with the ENOD8 expression cassette. Additionally, it was shown that the ENOD8 protein can be recombinantly synthesized by Nicotiana benthamiana in a soluble form, which could be tested for activity toward esterase substrates, bearing resemblance to nodule compounds, such as the Nod factor. Transcription localization studies using an ENOD8 promoter gusA fusion indicated that ENOD8 is expressed in the bacteroid-invaded zone of the nodule. The ENOD8 protein was also detected in that same zone by …
Date: December 2006
Creator: Coque, Laurent
System: The UNT Digital Library
General Chemistry Topic Coverage (GCTC) comparison between community colleges and universities in the United States. (open access)

General Chemistry Topic Coverage (GCTC) comparison between community colleges and universities in the United States.

This study is based on survey responses of 224 general chemistry instructors at United States (U.S.) community colleges and universities representing 46 states. The mean values of General Chemistry Topic Coverage (GCTC) score, developed by this researcher specifically for this dissertation study as a measure of course content, were statistically analyzed. The aim of this study is to answer five research questions: (a) Is there a difference in mean GCTC scores between U.S. community colleges and four-year colleges and universities? (b) If there is a difference in mean GCTC score between the two study groups, what are the observed differences in subtopics covered between community colleges and four-year colleges and universities? (c) Considering both community colleges and universities, is there a difference in mean GCTC score between the different designated U.S. regions? (d) Considering both community college and university professors, is there a difference in GCTC score for professors with a master's degree compared to those with a doctorate?, and (e) Is there a correlation between GCTC score and the percentage of students that major in science? Results indicate that there is a statistically significant difference in course content between community colleges and universities, there is a statistically significant difference …
Date: December 2006
Creator: El-Ashmawy, Amina Khalifa
System: The UNT Digital Library
Grid-based Coordinated Routing in Wireless Sensor Networks (open access)

Grid-based Coordinated Routing in Wireless Sensor Networks

Wireless sensor networks are battery-powered ad-hoc networks in which sensor nodes that are scattered over a region connect to each other and form multi-hop networks. These nodes are equipped with sensors such as temperature sensors, pressure sensors, and light sensors and can be queried to get the corresponding values for analysis. However, since they are battery operated, care has to be taken so that these nodes use energy efficiently. One of the areas in sensor networks where an energy analysis can be done is routing. This work explores grid-based coordinated routing in wireless sensor networks and compares the energy available in the network over time for different grid sizes.
Date: December 2006
Creator: Sawant, Uttara
System: The UNT Digital Library