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 Degree Level: Doctoral
 Collection: UNT Theses and Dissertations
Accurate and Reliable Prediction of Energetic and Spectroscopic Properties Via Electronic Structure Methods

Accurate and Reliable Prediction of Energetic and Spectroscopic Properties Via Electronic Structure Methods

Date: August 2013
Creator: Laury, Marie L.
Description: Computational chemistry has led to the greater understanding of the molecular world, from the interaction of molecules, to the composition of molecular species and materials. Of the families of computational chemistry approaches available, the main families of electronic structure methods that are capable of accurate and/or reliable predictions of energetic, structural, and spectroscopic properties are ab initio methods and density functional theory (DFT). The focus of this dissertation is to improve the accuracy of predictions and computational efficiency (with respect to memory, disk space, and computer processing time) of some computational chemistry methods, which, in turn, can extend the size of molecule that can be addressed, and, for other methods, DFT, in particular, gain greater insight into which DFT methods are more reliable than others. Much, though not all, of the focus of this dissertation is upon transition metal species – species for which much less method development has been targeted or insight about method performance has been well established. The ab initio approach that has been targeted in this work is the correlation consistent composite approach (ccCA), which has proven to be a robust, ab initio computational method for main group and first row transition metal-containing molecules yielding, on ...
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O-Acetylserine Sulhydralase-A from Salmonella typhimurium LT-2: Thermodynamic Properties and SPectral Identification of Intermediates

O-Acetylserine Sulhydralase-A from Salmonella typhimurium LT-2: Thermodynamic Properties and SPectral Identification of Intermediates

Date: August 1993
Creator: Simmons, James Walter
Description: O-Acetylserine Sulfhydrylase (OASS) is a pyridoxal phosphate enzyme that catalyzes the reaction of O-acetyl-Lserine with sulfide to give L-cysteine. OASS is present as two isoforms, designated -A and -B. The kinetic mechanism of OASS-A is well known and there is also much known concerning the acid-base chemistry of the enzyme. However, little is known concerning the location of the rate determining steps, the sequencing of chemical steps that occur at the active site, or the nature of the rate determining transition states. The studies performed to help elucidate these aspects of the OASS-A mechanism included determination of the thermodynamics of both half reactions, along with studies utilizing substrate analogs of OAS halting the reaction at specific points along the reaction pathway allowing the identification of reaction intermediates. The free energy change of the first half reaction was shown to be -5.7 Kcal/mole while the second half reaction was shown to be, for all intents and purposes, irreversible. Intermediates along the reaction pathway that have been previously identified include the internal Schiff base and the a-aminoacrylate. The external Schiff base was identified using the analogs cysteine, alanine, and glycine while the geminal diamine was identified using the analog serine. Formation of ...
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An Action Research Study of Community Building with Elementary Students in a Title I School

An Action Research Study of Community Building with Elementary Students in a Title I School

Date: May 2014
Creator: Dew, SaraBeth
Description: “In what ways does teaching with folk arts inspired visual arts-based instruction enhance community building among elementary students in a Title I school?” was the primary research question in this study. Agreeing with past and present day research that the construct of community is vital to social and cultural capital, this research attempts to determine how the notion of community benefits both students and teachers in the elementary art classroom. Folk art was utilized because this genre was accessible in terms of locality and familiarity among students and teachers. The purpose of this investigation was to produce teaching strategies and methods that show how community can be formed in the art classroom. The participants were elementary students, Grades 2 and 3, in a Title I school located in Denton, Texas. This investigation was conducted under an action research methodology. This approach to research is intended to be transformational, emergent, and accommodating. I recorded observations, field notes, and conversations from the participants. Emergent themes were discovered through content analysis and conceptual maps. Results from this investigation concluded transformation is only possible if the person wants change to happen. Data also showed that community and art education are symbiotic. Transformation, growth, and ...
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Actions Taken by Texas School Districts to Prevent Fraud

Actions Taken by Texas School Districts to Prevent Fraud

Date: May 2011
Creator: Taylor, Gordon Douglas
Description: This research is a descriptive analysis answering the question, what measures are currently taken by the leadership―boards of trustees and superintendents of schools―of Texas school districts to prevent embezzlement? The research perspective utilized was quantitative with a descriptive, cross-sectional design. Data collection was accomplished through a survey with questions constructed from the most commonly recommended strategies discovered through the review of literature. The survey was distributed to the 1031 superintendents of school districts in Texas via email. The response rate was 33% or 339 returned surveys. The data set created concentrates on the four most common preventive measures: policy and procedure, management, auditing, and ethics. These measures are considered as they function to interrupt the principles of the fraud triangle. Comparisons were completed regarding region, district size, superintendent tenure and superintendent experience. Policy adoption was found to be extremely widespread. Procedures written to fully implement policy were less prevalent. Review of management practices found problems concerning credit cards, personnel evaluations, and password access to multiple computer finance recordkeeping systems concentrated in one employee. External auditing programs were universal due to statutory mandate but internal auditors and internal audit committees were few. Ethics training for business office personnel existed but with ...
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An actor-partner interdependence model of attachment processes, conflict resolution, and psychological abuse on relationship quality in a community sample of heterosexual couples.

An actor-partner interdependence model of attachment processes, conflict resolution, and psychological abuse on relationship quality in a community sample of heterosexual couples.

Date: May 2009
Creator: Bretz, Karen
Description: The purpose of this study is to determine whether adult attachment style, psychological abuse in the marriage, conflict resolution strategies, and gender are associated with relational quality in childless couples in the early years of their marriage. Data were collected from 92 married couples who were recruited from university campuses, churches, and community organizations through e-mails, flyers, newspaper advertisements and mailings. Conceptualizing the interdependence of dyadic data from the actor-partner interdependence model (APIM), multilevel linear modeling (MLM) was used to analyze differences within and between couples. It was hypothesized that higher levels of attachment anxiety or avoidance, psychological abuse, and maladaptive conflict resolution strategies would be associated with lower relational quality. Results indicated that attachment avoidance had stronger associations with relational quality than did attachment anxiety, and that higher levels of attachment avoidance were associated with lower relational quality. Additionally, findings indicated a direct negative relationship between both actor and partner psychological abuse and the actor's relational quality. The discussion section addresses strengths and limitations of the present study as well as directions for future research.
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N-Acylethanolamine metabolism during seed germination: Molecular identification of a functional N-acylethanolamine amidohydrolase.

N-Acylethanolamine metabolism during seed germination: Molecular identification of a functional N-acylethanolamine amidohydrolase.

Date: August 2004
Creator: Shrestha, Rhidaya
Description: N-Acylethanolamines (NAEs) are endogenous lipid metabolites that occur in a variety of dry seeds, and their levels decline rapidly during the first few hours of imbibition (Chapman et al., 1999, Plant Physiol., 120:1157-1164). Biochemical studies supported the existence of an NAE amidohydrolase activity in seeds and seedlings, and efforts were directed toward identification of DNA sequences encoding this enzyme. Mammalian tissues metabolize NAEs via an amidase enzyme designated fatty acid amide hydrolase (FAAH). Based on the characteristic amidase signature sequence in mammalian FAAH, a candidate Arabidopsis cDNA was identified and isolated by reverse transcriptase-PCR. The Arabidopsis cDNA was expressed in E. coli and the recombinant protein indeed hydrolyzed a range of NAEs to free fatty acids and ethanolamine. Kinetic parameters for the recombinant protein were consistent with those properties of the rat FAAH, supporting identification of this Arabidopsis cDNA as a FAAH homologue. Two T-DNA insertional mutant lines with disruptions in the Arabidopsis NAE amidohydrolase gene (At5g64440) were identified. The homozygous mutant seedlings were more sensitive than the wild type to exogenously applied NAE 12:0. Transgenic seedlings overexpressing the NAE amidohydrolase enzyme showed noticeably greater tolerance to NAE 12:0 than wild type seedlings. These results together provide evidence in vitro ...
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Adapting Filial Therapy for Families who have a Child with a Life-Threatening Illness

Adapting Filial Therapy for Families who have a Child with a Life-Threatening Illness

Date: August 2004
Creator: Steen, Rheta LeAnne
Description: Utilizing a collective case study design, I examined and described the filial therapy (FT) process and adaptations discovered to be necessary and unnecessary in working with families who have a child with a life-threatening illness in the hospital setting. Data from a total of 7 parents was utilized, including those who terminated early, in order to gain a greater understanding of adapting FT for families who have a child with a life-threatening illness and their participation patterns. The parents attended 10 one- to two-hour FT sessions. The data was analyzed to examine for themes, patterns and relationships intrinsically with each case participant, as well as across cases. Analysis indicated that parents with a child with a life-threatening illness had great difficulty committing to attend FT; and a high rate of attrition occurred for those who did commit. A theme regarding flexibility was found to be of eminent importance in a variety of manifestations including therapeutic methods, session format, location and time of sessions, and intense vs traditional FT. Therapeutic adaptations in flexibility found to be important including openness to cathartic and personal parenting sessions, tolerance of forgetfulness, and lowering typical therapeutic concerns of dependency in the relationship. An inability for ...
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Adaptive planning and prediction in agent-supported distributed collaboration.

Adaptive planning and prediction in agent-supported distributed collaboration.

Date: December 2004
Creator: Hartness, Ken T. N.
Description: Agents that act as user assistants will become invaluable as the number of information sources continue to proliferate. Such agents can support the work of users by learning to automate time-consuming tasks and filter information to manageable levels. Although considerable advances have been made in this area, it remains a fertile area for further development. One application of agents under careful scrutiny is the automated negotiation of conflicts between different user's needs and desires. Many techniques require explicit user models in order to function. This dissertation explores a technique for dynamically constructing user models and the impact of using them to anticipate the need for negotiation. Negotiation is reduced by including an advising aspect to the agent that can use this anticipation of conflict to adjust user behavior.
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Addition, Omission and Revision: the Stylistic Changes Made to Zehn Variationen über ein Präludium von Chopin by Ferruccio Busoni, with Three Recitals of Selected Works by J.S. Bach, D. Scarlatti, Beethoven, Brahms, Debussy, Schumann and Liszt

Addition, Omission and Revision: the Stylistic Changes Made to Zehn Variationen über ein Präludium von Chopin by Ferruccio Busoni, with Three Recitals of Selected Works by J.S. Bach, D. Scarlatti, Beethoven, Brahms, Debussy, Schumann and Liszt

Date: December 1994
Creator: Yoon, Soomee
Description: This study examines what Busoni meant by "formal deficiencies" when he described his 1884 version of Chopin Variations, and reveals that changes made to the 1884 version during its process of revision in 1922 correct the "formal deficiencies" and show a fundamental change in Busoni's compositional style and perception of musical motion. Including a detailed analysis of the modifications, omissions, and additions made to the 1922 version (including an examination of the Chopin Prelude in C minor, op. 28, No. 20 as a theme to reveal aspects of its construction used in the variation process), which shows how these changes affect the work's compositional structure.
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The Adequacy of the Professional Preparation of the Catholic School Superintendent

The Adequacy of the Professional Preparation of the Catholic School Superintendent

Date: August 1964
Creator: Meyers, John F.
Description: The problem of this study was to determine the adequacy of the professional preparation of the Catholic school superintendent for his role as the educational leader in the diocesan school system. The study was divided into the following subdivisions: 1) establishing evaluative criteria to measure the adequacy of the professional preparation of the Catholic school superintendent; 2) evaluating the professional preparation of the superintendent in the light of the established criteria; 3) proposing a program which might close the gap between the existing practices and the established criteria.
Contributing Partner: UNT Libraries