UNT Theses and Dissertations - 269 Matching Results

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Dalbergia and Albizia: Plantlet Production via Tissue Culture, Karyological Evaluation, and Seed Anatomy with Scanning Electron Microscopy

Description: A publication by the National Academy of Sciences, USA (1979) outlined some of the research need for a great variety of economically important woody species whose remaining genetic resources need urgently to be collected and conserved. A viable regeneration system was established via tissue and cell suspension culture for Albizia falcataria and A. lebbeck, two important wood yielding leguminous tree species. The culture medium was standardized after several trials to obtain callus from the leaflet explants of these two tree species. The optimum use of casein hydrolysate (w/v) and coconut milk (v/v) in addition to 6-Benzylaminopurine and Indole-3-butyric acid could induce morphogenesis and somatic embryogenesis in the cultured tissue. This reports the first observation on somatic embryogenesis ofA. lebbeck using leaflets as the explants. Scanning Electron Microscopy and histological studies were done on the different stages plant development following standard techniques. Embryogenesis in suspension culture followed regeneration of plantlets in A. lebbeck. In A.falcaaria the regenerative process followed via organogenesis from the shoot buds developed on the leaf explants. After hardening the regenerated plants were transferred to the greenhouse. Some of the trees grew more than 25 feet tall within a few months outside the greenhouse. Karyotype of the three leguminous trees Albizia lebbeck, A. falcataria, and Dalbergia sissoo was analyzed. In D. sissoo, various chromosomal anomalies were observed in the cultured tissue. The abnormality indices and ploidy level varied with the age and the frequency of the subculture. In the aged culture the regenerative potential declined but was reinstated to some extent with the addition of two complex growth factors, coconut milk and casein hydrolysate. Seed anatomy of 26 species of 4 leguminous genera was studied with SEM. The main distinguishing anatomical features observed in the seed sections were uniseriate or multiseriate epidermis, epidermal projections, and number of rows ...
Date: December 1998
Creator: Ghosh, Nabarun
Partner: UNT Libraries

Biogeographic Relationships of Pocket Gophers (Geomys breviceps and Geomys bursarius) in the Southeastern Portion of Their Ranges

Description: This research utilized population genetic analyses (protein starch-gel electrophoresis and DNA sequencing of the cytochrome b mtDNA gene), host-parasite specificity (lice coevolution), remote sensing of satellite data, and geographic information systems (GIS) to characterize newly discovered populations of pocket gophers (genus: Geomys) in Arkansas. These populations are isolated and occur in seemingly unsuitable habitat in the Ozark Mountains of Arkansas. Analyses of electrophoretic and ectoparasite data suggested the populations in the Ozark Mountains represented isolates allied to Geomys bursarius, a species not known to occur in Arkansas. Comparison of mitochondrial DNA sequence data of the cytochrome b gene with that of other taxa and morphometric analyses confirmed that these populations are most closely allied to G. bursarius occurring to the north in Missouri. Moreover, these mtDNA sequence analyses indicated a degree of differentiation typical of that between other subspecies of pocket gophers. Therefore, these populations represent a distinct genetic entity in an intermediate stage of speciation and should be designated as a new subspecies, Geomys bursarius ozarkensis. Molecular clock analysis revealed a time of lineage divergence for this new subspecies as approximately 511,000 YBP. Due to the isolated nature and limited distribution of this subspecies, an evaluation of critical habitat needs was initiated. Remote sensing and GIS technologies were used to identify and describe suitable habitat Computerized classification of satellite imagery of suitable vegetation, integrated with ancillary digital information on soil associations, roads, and water systems, revealed that human activity had played a positive role in the establishment and dispersal of pocket gophers in this area. This research represents an initial combination of classical systematic tools with remote sensing and GIS to investigate biogeographic patterns and evolution. This project establishes a framework for using an interdisciplinary approach to studying organisms with limited distributions, determining evolutionary status, and providing recommendations for ...
Date: August 1998
Creator: Elrod, Douglas Allen
Partner: UNT Libraries

Role of α-Keto Acids In Cyanide Detoxification and Assimilation by Pseudomonas Bacteria

Description: Cyanide was rapidly removed when added to culture supernatants of seven different Pseudomonas. The ability to remove cyanide was correlated with the accumulation of α-keto acids (pyruvate and α-ketoglutarate). These compounds react with cyanide forming less toxic cyanohydrins, thus conferring a mechanism for bacterial cyanide tolerance. When added to growth media the α-keto acids were shown also to serve as effective cyanide antagonists. While all bacteria tested accumulated α-keto acids, only those capable of utilizing cyanide as a nutritional nitrogen source were able to metabolize cyanohydrins. In P. fluorescens NCIMB 11764, the same enzyme (cyanide oxygenase) shown previously to be involved in cyanide metabolism appears responsible for cyanohydrin transformation. Keto acid excretion is believed to represent a new mechanism of bacterial cyanide detoxification with further enzymatic metabolism of the cyanohydrins helping to explain how cyanide can satisfy the nitrogen requirement in cyanide-utilizing bacteria.
Date: December 1998
Creator: Pan, Guangliang
Partner: UNT Libraries

Development of an In Vitro Protoplast Culture System for Albizia Lebek (L.) Benth., an Economically Important Leguminous Tree

Description: An in vitro system of generating protoplasts from their callus cultures was established. The friable callus was more productive in terms of producing protoplasts than the green compact callus. The concentration of the various cell wall degrading enzymes had an effect on the viability of the protoplasts in the medium. The protoplast system developed from the experiments was stable and could be used for the transformation experiments of Albizia lebek and for other plant improvement practices.
Date: August 1998
Creator: Sinha, Debleena
Partner: UNT Libraries

Estimated Extent and Fate of Chlorinated Solvent Contamination in the Soil of the Naval Air Station, Dallas, Texas

Description: This thesis estimates the spatial extent of chlorinated solvent contamination of the soil at the Naval Air Station, Dallas, then estimates the fate and transport of these contaminants, over time, using the Soil Transport and Fate database and the Vadose-Zone Interactive Processes (VIP) modeling software. Geostatistical analysis identifies two areas with serious chlorinated solvent contamination. Fate and transport modeling estimates that this contamination will degrade and disperse from the soil phase to below regulatory limits within one year, although there is a risk of groundwater contamination. Contaminants are estimated to persist in the water and air phases of the soil. Further sampling is recommended to confirm the results of this study.
Date: August 1998
Creator: Trescott, Jill V. (Jill Virginia)
Partner: UNT Libraries

Analyses of Particulate Contaminants in Semiconductor Processing Fluids

Description: Particle contamination control is a critical issue for the semiconductor industry. In the near future, this industry will be concerned with the chemical identities of contaminant particles as small as 0.01 pm in size. Therefore, analytical techniques with both high chemical sensitivity and spatial resolution are required. Transmission electron microscopy (TEM) provides excellent spatial resolution and yields structural and compositional information. It is rarely used, however, due to the difficulty of sample preparation. The goals of this research are to promote the use of TEM as an ultrafine particle analysis tool by developing new sample preparation methods, and to exploit the new TEM techniques for analysis of particles in semiconductor processing fluids. A TEM methodology for the analysis of particulate contaminants in fluids with an elemental detectability limit as low as 0.1 part per trillion (ppt), and a particle concentration detectability limit as low as 1 particle/ml for particles greater than 0.2 pm was developed and successfully applied to the analysis of particles in HF, H202, de-ionized (DI) water, and on the surface of an electronic device. HF samples from three manufacturers were examined. For HF (B), the maximum particle concentration was 8.3 x 103 particles/ml. Both a viscous material and lath-shaped particles were observed. The Sb concentration was less than 0.6 part per billion (ppb). HF (C) was the cleanest. CaF2 and TiO2 particles were identified in HF (D). For H2 02, iron and tin oxides and hydroxides were identified. The maximum particle concentration was 990 particles/ml. The Sn and Fe concentrations were less than 0.3 ppb. Spherical and dendritic particles were observed. For DI water, spherical and dendritic particles (<2 particles/ml), and particles containing Fe or Si with concentrations less than 0.1 ppt were observed. Contaminants on an electronic device surface were also analyzed. Clusters of small particles ...
Date: August 1998
Creator: Xu, Daxue
Partner: UNT Libraries

Regulation of an S6/H4 Kinase in Crude Lymphosarcoma P1798 Preparations

Description: Purified S6/H4 kinase (Mr 60,000) requires autophosphorylation for activation. A rabbit anti-S6/H4 kinase peptide (SVIDPVPAPVGDSHVDGAAK) antibody recognized both the S6/H4 kinase holoenzyme and catalytic domain. Immunoreactivity with p60 kinase protein, and S6/H4 kinase activity were precisely correlated in fractions obtained from ion exchange chromatography of P1798 lymphosarcoma extracts. An enzyme which catalyzed the MgATP-dependent phosphorylation and activation of S6/H4 kinase coeluted with immunoreactivity from Mono 5, but not Mono Q chromatography. Since S6/H4 kinase is homologous with rac-activated PAK65, the observation that phosphorylation is also required for activation suggests a complex mechanism for in vivo activation of the S6/H4 kinase.
Date: December 1998
Creator: Taylor, Allison Antoinette
Partner: UNT Libraries

From Theory to Practice: A First Look at Success for Life - A Brain Research-Based Early Childhood Program

Description: Success For Life (SFL) is a brain research-based program for children, birth through age six. This research examined the development and implementation of SFL in 13 early childhood settings. Participants were 24 female early childhood teachers and 146 (73 male) children. Teachers included seven infant, four toddler, nine preschool and four kindergarten teachers. Children included infants(n=29), toddlers(n=27), and prek/kindergartners (n=90). A Request for Proposals was disseminated to identify possible implementation sites. After participation was confirmed, teachers attended a full day's training which included a description of brain development/function, the latest brain research, how to implement SFL and other logistics of the study. Program implementation occurred over approximately four months. A field site coordinator visited each site bimonthly to provide on-going technical assistance. This was an intervention project with a pre and post implementation design. Four instruments were used: a teacher questionnaire, a classroom environment measure, a child measure and teacher journals. Results suggested that teachers became more knowledgeable about brain development research and about how children grow and learn. Teachers were better able to make connections between brain research findings and how to apply these findings to their programs and daily activities. Likewise, the environment measure indicated that teachers were better able to arrange environments for learning. They reported that children showed significant increases in skills development and performance in the following areas: physical mastery, social relations/interactions, cognitive development, and language/communications. Additionally, teachers reported improvements in emotional expression and well-being among infants and toddlers. Toddlers and preschoolers showed significant increases in creative/ artistic expression. Finally, teachers indicated that preschoolers showed increases in initiative, use of logic/mathematics skills, and musical coordination and movement. Research findings suggest that Success For Life is able to bridge the gap between theory and practice and benefits children, teachers and programs.
Date: December 1998
Creator: Castro, R. Raquel
Partner: UNT Libraries

Non-Academic Institutional Variables Related to Degree Completion of Non-Traditional Age Undergraduate Students

Description: A study was conducted at The University of Texas at Arlington to obtain measurements of non-traditional age undergraduate students using the Mattering Scales for Adult Students in Higher Education (MHE). The MHE is designed to assess the perceptions of adult students on how much they matter to the institution they are attending. The study also sought to determine if "mattering" and other selected nonacademic variables associated with the university environment are perceived by nontraditional age students to effect their likelihood of completing their baccalaureate degree. Of the five subscales surveyed by the MHE, significant statistical differences were found to exist in the Administration, Interaction With Peers, Multiple Roles, and Faculty subscales denoting an interaction between gender and minority status. Significant statistical differences were also found by gender on the Advising subscale and by minority status on the Faculty subscale.
Date: August 1998
Creator: Walts, Rebecca Ann.
Partner: UNT Libraries

Synthesis of the Personal and the Political in the Works of May Stevens

Description: This thesis is an investigation of the way in which the painter May Stevens (b. 1924) synthesizes her personal experiences and political philosophy to form complex and enduring works of art. Primary data was accumulated through an extended interview with May Stevens and by examining her works on exhibit in New York and Boston. An analysis of selected works from her "Big Daddy" and "Ordinary/Extraordinary" series revealed how her personal feelings about her own family became entwined with larger political issues. As an important member of the feminist art movement that evolved during the 1970s, she celebrated this new kinship among women in paintings that also explored the contradictions in their lives. In more recent work she has explored complex social issues such as teenage prostitution, sexism, and child abuse in a variety of artistic styles and media. This study investigates how May Stevens continues to portray issues of international significance in works that consistently engage the viewer on a personal, almost visceral level.
Date: May 1998
Creator: Abbott, Janet Gail
Partner: UNT Libraries

The Relationship between Privatization, Culture, Adoption of International Accounting Standards, and Accounting in Egypt

Description: This study explores how the Egyptian socioeconomic factors impacted the implementation of International Accounting Standards (IASs) in Egypt. Prior research concluded that developing nations have special needs when it comes to accounting and financial reporting and recommended nation-specific analysis. The author adapts Gray's (1988) model, which connects Hofstede's cultural dimensions with accounting practice, to fit the Egyptian environment.
Date: December 1998
Creator: Dahawy, Khaled M.
Partner: UNT Libraries

Mandatory Continuing Education in Nursing: a Texas Perspective

Description: This study investigated Texas nurses' attitudes toward mandatory continuing education, and their perceptions of skill improvement, knowledge enrichment and improvement of health care to the public as a result of participation in twenty contact hours of continuing education programs as required by the Board of Nurse Examiners for the State of Texas. This sample of Texas nurses felt that the goals set forth by the Board of Nurse Examiners for the State of Texas had been met by participation in mandatory continuing education. However, given the small return rate, the attitudes of these nurses may not represent the attitudes of the majority of Texas nurses.
Date: May 1998
Creator: Prater, Llewellyn Swan
Partner: UNT Libraries

MMPI-2 Patterns of Adults with Attention-Deficit Hyperactivity Disorder

Description: Recent literature suggests that not only does Attention-deficit Hyperactivity Disorder (ADHD/ADD) persist into adulthood, but it can also be accompanied by personality characteristics which cause emotional difficulties. In fact, adults diagnosed with ADHD can present with a profusion of difficulties. Several constructs appear to accumulate dynamically throughout development to place the adult with ADHD at risk for multiple emotional problems. These interwoven influences include familial characteristics, childhood emotional and academic difficulties, and inadequate coping skills to respond to adulthood pressures. This document, first, describes a developmental model for conceptualizing negative trajectories leading to nonadaptive coping and psychopathology and identifies personality factors of adults diagnosed with ADHD. This model provides clinicians and researchers with a better understanding of the complexity and challenges of adulthood ADHD in order to aid in diagnosis, treatment, and prevention. The purpose of this study is to examine personality factors common to adults diagnosed with ADHD and compares these characteristics with a group of adults diagnosed with a depressive disorder. Adults responding to a community advertisement who provided documentation of the diagnosis of Attention-deficit Hyperactivity Disorder were administered the MMPI-2. This ADHD group was compared with MMPI-2 profiles of a group of adults diagnosed with Major Depressive Disorder or Dysthymic Disorder. A cluster analysis procedure was performed and results are discussed.
Date: August 1998
Creator: Campbell, Catherine Elaine
Partner: UNT Libraries

Characterization of Aspartate Transcarbamoylase and Dihydroorotase in Moraxella Catarrhalis

Description: Bacterial aspartate transcarbamoylases (ATCase's) are divided into three classes that correspond to taxonomic relationships within the bacteria. The opportunistic pathogen Moraxeila catarrhalis has undergone several reclassifications based on traditional microbiological criteria. The previously uncharacterized ATCase from M. catarrhalis was purified to homogeneity and its chemical properties characterized. The ATCase from M. catarrhalis is a class C ATCase with an apparent molecular mass of 480-520 kDa. The M. catarrhalis ATCase is a dodecomer composed of six 35 kDa polypeptides and six 45 kDa polypeptides. The enzyme has an unusually high pH optimum of greater than pH 10. The enzyme exhibited hyperbolic kinetic with a Km for aspartate of 2 mM. A single, separate 78 kDa dihydroorotase from M. catarrhalis was identified and it was not associated with ATCase. These data support the reclassification of M. catarrhalis out of the Neisseriaceae family.
Date: May 1998
Creator: Fowler, Michael A. (Michael Allen), 1961-
Partner: UNT Libraries

"The Best Stuff Which the State Affords": a Portrait of the Fourteenth Texas Infantry in the Civil War

Description: This study examines the social and economic characteristics of the men who joined the Confederate Fourteenth Texas Infantry Regiment during the Civil War and provides a narrative history of the regiment's wartime service. The men of the Fourteenth Infantry enlisted in 1862 and helped to turn back the Federal Red River Campaign in April 1864. In creating a portrait of these men, the author used traditional historical sources (letters, diaries, medical records, secondary narratives) as well as statistical data from the 1860 United States census, military service records, and state tax rolls. The thesis places the heretofore unknown story of the Fourteenth Texas Infantry within the overall body of Civil War historiography.
Date: December 1998
Creator: Parker, Scott Dennis
Partner: UNT Libraries

The Effects of an Experimentally-Induced Bodily Focus Experience on a Psychotherapist during a Psychotherapy Session

Description: The purpose of this study is to contribute to the current process research by investigating a psychotherapist's experience during psychotherapy. Massage therapy and relaxation therapy were used to manipulate psychotherapist's bodily focus, physiology, and affective state. Topics discussed include: the bodily focus of the therapist, neurobiological models of experience, mind-body boundary issues, and a present-time focus. Doctoral level Counseling and Clinical graduate students were used as participants.
Date: August 1998
Creator: Koehler, Gregory C. (Gregory Charles)
Partner: UNT Libraries

Social Validation of Intervention Procedures for Emotionally Disturbed Students : Effects on Regular Education Students

Description: The purpose of this study was to explore regular education student perceptions of the effects of implementing behavioral interventions for seriously emotionally disturbed students (SED) in the regular classroom. Student perceptions of classroom friction or disruptiveness, apathy, and general enjoyment or satisfaction were evaluated. It was predicted that regular education students would report more classroom friction, increased apathy, and less satisfaction when interventions were implemented in the regular classroom for a target SED student.
Date: December 1998
Creator: Thomson, Marty C.
Partner: UNT Libraries

Responses of Cultured Neuronal Networks to the Cannabinoid Mimetic Anandamide

Description: The effects of cannabinoid agonists on spontaneous neuronal network activity were characterized in murine spinal cord and auditory cortical cultures with multichannel extracellular recording using photoetched electrode arrays. Different cultures responded reproducibly with global decreases of spiking and bursting to anandamide and methanandamide, but each agonist showed unique minor effects on network activity. The two tissues responded in a tissue-specific manner. Spontaneous activity in spinal tissue was terminated by 1 μM anandamide and 6.1 μM methanandamide. Cortical activity ceased at 3.5 μM and 2.8 μM respectively. Irreversible cessation of activity was observed beyond 8 μM for both tissues and test substances. Palmitoylethanolamide, demonstrated that CB2 receptors were not present or not responsive. However, the data strongly suggested the presence of CB1 receptors.
Date: May 1998
Creator: Morefield, Samantha I. (Samantha Irene)
Partner: UNT Libraries

A Comparative Study of the Impact of the Total Quality Management Program on Exit Level Texas Assessment of Academic Skills Scores

Description: The management style being used by school personnel in Texas and across the nation today is predominately that of a bureaucracy. This model was organized around the industrial revolution that was exercising authority at the turn of the century. Writers and researchers have pointed out that such a model is not capable of providing students the knowledge and skills they will need to enter an increasingly demanding society. One management style relatively new to the educational arena today is that of Total Quality Management. This study reports the results of the impact of the training in those principles by measurement of student test scores.
Date: December 1998
Creator: Maulding, Wanda Smith
Partner: UNT Libraries

Unearthing the Spiritual Message in Edward Abbey's Desert Solitaire

Description: Unearthing Edward Abbey's spiritual philosophy is not an easy task. One must sift through Abbey's humor, sort through Cactus Ed's flamboyant character, look under the veneer of this character, and beyond Abbey's overt objective of convincing readers to defy the destruction of wilderness, and only then does the spiritual philosophy of Abbey become visible. To understand his perception of spirituality, one must define what constitutes a mystic and determine what American theological philosophies mystics tend to adopt. Once these are defined, one can apply those principles to Abbey's Desert Solitaire, and determine that Abbey is a nature mystic who adheres to the ecocentric based immanence theology. This theology is contrary to the Judeo-Christian based emanation theology which supports anthropocentricism and resourcism.
Date: August 1998
Creator: Jacobs, Pamela
Partner: UNT Libraries

Pedagogical and Andragogical Principles of John Wesley's Anthology

Description: This study is a historical and philosophical analysis of significant educational concepts John Wesley espoused during his lifetime from 1703-1791. Specifically this document examines Wesley's use of pedagogical and andragogical principles through the educational undertakings of the early Methodist movement.
Date: August 1998
Creator: Hall, Elaine Friedrich
Partner: UNT Libraries

Hormones, Distress, and Immune Functioning in Women

Description: The present study set out to investigate the biopsychosocial model of illness using variables previously identified as directly impacting illness or as mediating the relationship between other variables and illness. Oral contraceptive use, stress, and negative affect were investigated as predictors of immunological competence, measured by the level of Immunoglobulin G antibodies to Epstein-Barr Virus Viral Capsid Antigen (EBV-VCA IgG).
Date: August 1998
Creator: Rubino-Watkins, Maria Francesca
Partner: UNT Libraries

Use of Stufflebeam's CIPP Model to Assess a Change Effort in a Division of a University Library

Description: Reorganization efforts within colleges and universities are increasingly considered as institutions look for ways to streamline operations for financial cost savings or competitive advantage. The purpose of this study was to assess a particular change effort in a university library which took place between August, 1996 and July, 1997. A team was formed to manage the change effort, and an outside consultant was hired to facilitate the process and guide the team. Stufflebeam's evaluation model was used as a conceptual framework to evaluate the entire process which included a particular change management model brought in by the consultant. The entire change effort was described by the author as a participating member of the team and assessed by gathering feedback from team members, library staff members affected by the effort, and members of the library administration.
Date: August 1998
Creator: Dworaczyk, William J.
Partner: UNT Libraries