Degree Level

The Effects of Parenting Stress and Academic Self-Concept on Reading Ability in a Clinic Referral Sample

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This study investigated the relationships among the variables of parenting stress, academic self-concept, and reading ability. The purpose of this study was to determine whether parenting stress and academic self-concept contributed to the child's reading ability. Two hypotheses were investigated in an effort to accomplish this purpose. The subjects used in this study were forty-nine children and their primary caretakers referred to The Child and Family Resource Center, The University of North Texas, Denton, Texas, during the academic years of 1994 through 1999. Subjects ranged in age from seven to eighteen years of age. Academically, the subjects ranged from first graders through eleventh graders. All subjects lived in and attended schools in Denton County or neighboring counties. Parental employment ranged from unskilled laborers to medical doctors. The participating families included biological, step, adoptive, single, and divorced families. Abidin's Parenting Stress Index was used to measure parental stress experienced by the primary caretaker. The Intellectual and School Status cluster of the Piers-Harris Children's Self-Concept Scale was used to measure the child's academic self-concept and the Woodcock Reading Mastery Test-Revised provided a measure of the child's reading ability. Test scores were obtained following a review of The Child and Family Resource Center's …
Date: May 2001
Creator: Maldonado, Michele L.
System: The UNT Digital Library

Effectiveness of Filial/Play Therapy Training on High School Students' Empathic Behavior with Young Children

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This study was designed to determine the effectiveness of a filial/play therapy training model with high school juniors and seniors enrolled in a Peer Assistance and Leadership program (PALs). Filial/play therapy is an intervention that focuses on strengthening and enhancing adult-child relationships. The high students are trained to be a therapeutic change agent for primary school children identified as having adjustment difficulties by utilizing basic child-centered play therapy skills in weekly play sessions with young children. Specifically, this study is designed to determine the effectiveness of filial therapy in increasing: 1) the high school students' observed empathic behavior with young children, 2) the high school students' observed attitude of acceptance toward young children, 3) the high school students' observed ability to allow self-direction in young children, and 4) the high school students' observed level of involvement with young children. The experimental group, consisting of 16 volunteer high school students enrolled in a PALs class for high school credit, received a total of 24 weeks of filial/play therapy didactic training, application, and supervision for the playtimes they conducted with pre-kindergarten/kindergarten students identified with adjustment difficulties. The comparison group consisted of 15 volunteer high school students enrolled in a PALs class for …
Date: May 2001
Creator: Jones, Leslie D.
System: The UNT Digital Library

Riparian Forest Width and the Avian Community in a Greenbelt Corridor Setting

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The forest avian community of the Ray Roberts Greenbelt (Denton Co., Texas) was characterized for two years using point count station sampling, from fall 1998 to summer 2000. Richness data for both breeding seasons were correlated with two-spatial metrics: width of the riparian forest and distance to the nearest edge. There were significant correlations between forest interior species richness and both spatial metrics, for both breeding seasons. Based on these data, a minimum riparian forest width threshold of 400-meters is suggested to provide habitat for forest interior species, which have lost considerable habitat through forest fragmentation. Partners in Flight breeding bird priority concern scores were used to create a habitat priority index for the Trinity River bottomland hardwood forest system
Date: May 2001
Creator: Hoffman, Karl W.
System: The UNT Digital Library

Influences of the Mother-Daughter Relationship on Motivations for Sexual Behavior

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The influences of family relationship variables on motivations for adolescent sexual risk-taking were investigated. Previous research has linked these variables to adolescent sexual behavior, however, the nature of these links has not been specifically examined. Family variables were operationalized as child attachment to mother, parental support of each other, parental conflict strategies, and parental monitoring. Emotional motivations were operationalized as attachment and affiliation needs. The sample consisted of 40 single females ages 18 to22 recruited from a local pregnancy care center. Predictions that parent-child relationship and parental influence would predict emotional motivations for sexual risk-taking were not supported. The variable most highly related to sexual risk-taking, though not included in the model tested, was father's destructive conflict strategies. Theoretical and methodological issues are discussed.
Date: May 2001
Creator: Barrett, Susan
System: The UNT Digital Library

Development of a Procedure to Evaluate Groundwater Quality and Potential Sources of Contamination in the East Texas Basin

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This study contributes a procedure, based on data analysis and geostatistical methods, to evaluate the distribution of chemical ratios and differentiate natural and anthropogenic contaminant sources of groundwater quality in the East Texas Basin. Four aquifers were studied, Sparta, Queen City, Carrizo and Wilcox. In this study, Carrizo- Wilcox is considered as one aquifer, and Sparta-Queen City as another. These aquifers were divided into depth categories, 0-150 feet for Sparta-Queen City and 300-600 feet and 600-900 feet for Carrizo-Wilcox in order to identify individual sources of contamination. Natural sources include aquifer mineral make up, salt domes and lignite beds. Major anthropogenic sources include lignite and salt dome mining and oil-gas production. Chemical ratios selected were Na/Cl, Ca/Cl, Mg/Cl, SO4/Cl, (Na+Cl)/TDS, SO4/Ca and (Ca+Mg)/(Na+K). Ratio distributions and their relationships were examined to evaluate physical-chemical processes occurring in the study area. Potential contaminant sources were used to divide the Basin into three areas: Area 1 to the east, Area 2 in the west and Area 3 in the center. Bivariate analysis was used to uncover differences between the areas. The waters in Area 1 are potentially impacted primarily from oil field waters. Sources present in Area 2 include lignite beds and oil …
Date: May 2001
Creator: Alderman, John H.
System: The UNT Digital Library

The Effect of Faculty Development on Active Learning in the College Classroom

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This study examined the effect of active learning seminars and a mentoring program on the use of active learning teaching techniques by college faculty. A quasi-experimental study was conducted using convenience samples of faculty from two private Christian supported institutions. Data for the study were collected from surveys and faculty course evaluations. The study lasted one semester. Faculty volunteers from one institution served as the experimental group and faculty volunteers from the second institution were the comparison group. The experimental group attended approximately eight hours of active learning seminars and also participated in a one-semester mentoring program designed to assist faculty in application of active learning techniques. Several individuals conducted the active learning seminars. Dr. Charles Bonwell, a noted authority on active learning, conducted the first three-hour seminar. Seven faculty who had successfully used active learning in their classrooms were selected to conduct the remaining seminars. The faculty-mentoring program was supervised by the researcher and conducted by department chairs. Data were collected from three surveys and faculty course evaluations. The three surveys were the Faculty Active Learning Survey created by the researcher, the Teaching Goals Inventory created by Angelo and Cross, and the college edition of Learner-Centered Practices by Barbara …
Date: May 2001
Creator: Evans, Cindy
System: The UNT Digital Library

A Transcription of Op. 94 Morceau de Concert, by Camille Saint-Saëns For Solo Bass Trombone and Brass Ensemble

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The transcription is an addition to the repertoire for brass ensemble and bass trombone. Consideration is given to the nineteenth-century orchestration treatises of Berlioz and Strauss as well as the twentieth-century texts of Erik Leidzén, Walter Piston, and Samuel Adler. The transcription process is shaped by the principles of these writers. The score is contained in the appendix.
Date: May 2001
Creator: Woods, Christopher P.
System: The UNT Digital Library

Equivalency of paper-pencil tests and computer-administered tests.

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Are computer-administered versions of a multiple choice paper-pencil test equivalent? This study determined whether there were any significant differences between taking a traditional pencil-paper test and taking the same test using a computer. The literature has shown that there are intervening variables that have caused differences when not controlled. To prove equivalency between test modes, scores have to have similar means, dispersions, and shapes; the ranked-order of the scores must also be similar. Four tests were given over the course of a 16-week semester. The sample was divided, half taking paper-pencil tests and half taking the same test administered by a computer. The mode of administration was switched with each test administration. The analysis showed that, when the intervening variables were controlled, the two modes of administration were equivalent. The analysis used a 2x4 ANOVA, which showed no difference between test modes, but showed that each test administration was significantly different. The Levene statistic was used to test whether dispersions were equivalent and confidence intervals were established to test the kurtosis and skewness statistics. Finally, each of the test scores were transformed into their Normal Curve Equivalents so that Pearson's coefficient could be used to determine the equivalency of the …
Date: May 2001
Creator: Whitworth, Clifford K.
System: The UNT Digital Library

Teen ages: Youth market romance in Hollywood teen films of the 1980s and 1990s

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This thesis examines the differences between teen romantic comedy films marketed to Generation X teenagers in the 1980s and Generation Y teenagers in the 1990s, focusing on the presentation of gender roles, consumptive behavior, and family. The 1980s films are discussed within the social context of the Reagan era and the conservatism of the New Right. The 1990s films are examined as continuing a conservative sensibility, but they additionally posit consumption as instrumental to achieving an idealized romance. Romantic comedy is traditionally a conservative genre, but these films illustrate female liberation through consumption. The source of difference between the cycles of teen romantic comedy is attributed to the media's attempt to position Generation Y teenagers as ideal consumers.
Date: May 2001
Creator: Murphy, Caryn E.
System: The UNT Digital Library

Inequality in Access to, and Utilization of, Health Care - The Case of African American and Non-Hispanic White Males

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Using data from the Household Component of the 1996 Medical Expenditure Panel Survey, the study compares (1) the accessibility, and (2) the predictors of health care services utilization among African American and non-Hispanic White males, 18 to 65 years old in the United States. Using ANOVA procedure in comparing the means for use of physicians, hospitals, doctors, and difficulty obtaining care, seven hypotheses were tested in the study. First, it was hypothesized that African American men of working age will have less access to health care services (physicians, hospitals, and dentists), and be more likely to report having experienced delay or difficulty obtaining care, compared to non-Hispanic white males of working age. Second, it was hypothesized that, controlling for health status, African American men of working age will have less access to health care services (physicians, hospitals, and dentists), and will also be more likely to experience delay or difficulty obtaining care, than non-Hispanic white males. This was followed by the third hypothesis which compared utilization of physicians, hospitals, dentists, and difficulty obtaining care among African American and non-Hispanic white males, controlling for health status and insurance coverage (any insurance, private insurance, any public insurance, and Medicaid). Hypotheses four through …
Date: May 2001
Creator: Sakyi-Addo, Isaac
System: The UNT Digital Library

Analysis of the Impact of CACREP Accreditation of Counselor Education Programs on Student Knowledge Outcomes

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The principal investigator (PI) for this study analyzed mean scores on the National Counselor Examination (NCE) of students from CACREP accredited and non- CACREP accredited programs. Data was provided by the National Board of Certified Counselors, Inc., for a total of ten examination administrations across six years. The fourteen variables examined in the study consisted of the eight common-core knowledge domains identified in CACREP standards, the five counselor work behavior areas identified by NBCC via periodic job analysis of counseling practice, and one overall or total score on the NCE. NCE mean scores of students from CACREP accredited programs were higher than NCE mean scores of students from non-CACREP accredited programs on all variables across all ten NCE administrations. Data seem to indicate that students from CACREP accredited programs perform significantly better on the NCE than students from non-CACREP accredited programs, in all fourteen variables. Sample size was large, totaling 9707, so the PI calculated effect sizes using Cohen's d for each variable to aid interpretation of statistical significance. Five variables had large effect sizes of .70 or higher. The higher effect size statistics were associated with the counselor work behavior areas, with the highest effect size (.85) associated with …
Date: May 2001
Creator: Scott, Susan W.
System: The UNT Digital Library

Temporally Correct Algorithms for Transaction Concurrency Control in Distributed Databases

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Many activities are comprised of temporally dependent events that must be executed in a specific chronological order. Supportive software applications must preserve these temporal dependencies. Whenever the processing of this type of an application includes transactions submitted to a database that is shared with other such applications, the transaction concurrency control mechanisms within the database must also preserve the temporal dependencies. A basis for preserving temporal dependencies is established by using (within the applications and databases) real-time timestamps to identify and order events and transactions. The use of optimistic approaches to transaction concurrency control can be undesirable in such situations, as they allow incorrect results for database read operations. Although the incorrectness is detected prior to transaction committal and the corresponding transaction(s) restarted, the impact on the application or entity that submitted the transaction can be too costly. Three transaction concurrency control algorithms are proposed in this dissertation. These algorithms are based on timestamp ordering, and are designed to preserve temporal dependencies existing among data-dependent transactions. The algorithms produce execution schedules that are equivalent to temporally ordered serial schedules, where the temporal order is established by the transactions' start times. The algorithms provide this equivalence while supporting currency to the …
Date: May 2001
Creator: Tuck, Terry W.
System: The UNT Digital Library

Burnout Among Student Affairs Professionals at Metropolitan Universities

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The purpose of this study was to determine the level of burnout among student affairs professionals at the 52 U.S. member institutions of the Coalition of Urban and Metropolitan Universities. Packets containing the Maslach Burnout Inventory (MBI), the Moos Work Environment Scale (WES), and a demographic survey were mailed to 371 senior student affairs administrators at the member institutions, with a completed response rate of 58.22%. The senior student affairs administrators surveyed included the chief student affairs officers and the professional staff who reported to them. The research design employed t-tests, analyses of variance, and Pearson's Product Moment correlations. The scores obtained from the MBI and WES subscales were compared overall and along 9 independent variablestitle of position, size of institution, appointment, salary, years in current position, years in profession, age, gender, and highest degree attained. Average levels of burnout were found on each of the MBI subscores. Contrary to earlier studies, women did not suffer from statistically significant higher levels of burnout than men, and burnout levels decreased with age and years in the profession for both sexes. Lower scores on the MBI depersonalization subscale were found in employees in mid-career and in professionals from smaller schools. Emotional exhaustion …
Date: August 2001
Creator: Murphy, Lynda
System: The UNT Digital Library

The Pettis Integral and Operator Theory

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Let (Ω, Σ, µ) be a finite measure space and X, a Banach space with continuous dual X*. A scalarly measurable function f: Ω→X is Dunford integrable if for each x* X*, x*f L1(µ). Define the operator Tf. X* → L1(µ) by T(x*) = x*f. Then f is Pettis integrable if and only if this operator is weak*-to-weak continuous. This paper begins with an overview of this function. Work by Robert Huff and Gunnar Stefansson on the operator Tf motivates much of this paper. Conditions that make Tf weak*-to-weak continuous are generalized to weak*-to­weak continuous operators on dual spaces. For instance, if Tf is weakly compact and if there exists a separable subspace D X such that for each x* X*, x*f = x*fχDµ-a.e, then f is Pettis integrable. This nation is generalized to bounded operators T: X* → Y. To say that T is determined by D means that if x*| D = 0, then T (x*) = 0. Determining subspaces are used to help prove certain facts about operators on dual spaces. Attention is given to finding determining subspaces far a given T: X* → Y. The kernel of T and the adjoint T* of T are used …
Date: August 2001
Creator: Huettenmueller, Rhonda
System: The UNT Digital Library

Submerged wood inhabiting macoinvertebrates of the Elm Fork of the Trinity River, Texas: Assemblage analyses, comparisons to the benthic fauna, and a study of Cyrnellus fraternus (Trichoptera: Polycentropodidae)

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Taxonomic composition and spatio-temporal variability of macroinvertebrates inhabiting snags were examined from an 8-km segment of the Elm Fork of the Trinity River. Seventy-seven macroinvertebrate taxa were collected from submerged wood during the study. Assemblages were highly variable spatially and temporally, especially among seasons. An ordination of species and environment did not find snag taxa to have striking correlations with many of the selected environmental variables, although there were some trends in flow-mediated species distributions. There were significant seasonal differences in the abundances of some taxa, particularly among the Chironomidae (Diptera). The Tribe Orthocladiini was numerically abundant during the winter, while the Tribes Chironomini and Tanytarsini dominated the summer and autumn. Additionally, this study included a secondary production and microdistribution analysis of a population of the caddisfly Cyrnellus fraternus. Distributions of C. fraternus were restricted to snags, the most stable substratum for retreat building and for resisting periodic high waters. Larvae were not found in the soft sand and mud benthic habitats near submerged wood. The insects were multivoltine with a minimum of three generations per year. Pupae were collected July through September and adults emerged from May through October. The population overwintered as larvae. Estimated annual production was 1,015.4 …
Date: August 2001
Creator: Johnson, Zane B.
System: The UNT Digital Library

A study of freshman interest groups and leadership practices at Texas Woman's University

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This study investigated the level of leadership practices and retention rates of freshman students at Texas Woman's University. The data for the study were collected using the Leadership Practices Inventory, Student Version. The sample for the study consisted of 151 freshman students. The students were each placed in one of three control groups. Group A students (the treatment group) were in the Neighbors Educated Together Program (NET). Group B students (control group) were in one of two university-sponsored programs (COLORS or University 1000), and Group C students (control group) were the residual group of first-time college freshmen. These three groups were surveyed prior to their participation in the NET program or a university-sponsored program and again at the end of 14 weeks. In addition, retention rates were examined on the 12 class day of the spring semester. The study found statistically significant differences (p <. 05) on the pretests and posttests between Group C, residual students, and the other two groups on the Enabling the Followers to Act subscale, the Inspiring a Shared Vision subscale, and Encouraging the Heart subscale. Group A, NET students, and Group B, COLORS/University 1000 students, showed no statistically significant differences between groups. The difference from …
Date: August 2001
Creator: Mendez-Grant, Monica S
System: The UNT Digital Library

The Symbolic Representation of Latinos: A Content Analysis of Prime-Time Television

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The media are powerful agents of socialization in modern society influencing values, beliefs, and attitudes of the culture that produces them. Both the quantity and quality of Latino images in the media may reflect and reinforce the place of Latinos in United States society. This study examines how Latinos are portrayed in television entertainment programming by addressing two major research questions: 1) What is the extent of Latino recognition on prime-time television? and 2) What is the extent of respect accorded Latinos on prime-time television? A one-week sample of prime-time television programming airing on three networks yielded 47 programs and 807 characters for analysis. Using content analysis methodology, recognition is identified by examining the frequency and proportional representation of Latino television portrayals and respect is measured by examining the types and significance of these roles. The results indicate an overall lack of diversity on prime-time television with only 11 of the 47 programs analyzed reaching 50% or more of the maximum possible diversity in their racial and ethnic portrayals. Specifically, Latinos represent only 3% of primetime television characters, less than one-fourth of their proportion of the nation's population. Compared to non-Hispanic Whites, Blacks, and Asians, Latinos are the group least …
Date: August 2001
Creator: McKenzie-Elliott, Tracey M.
System: The UNT Digital Library

Anne Brontë's New Women: Agnes Grey and The Tenant of Wildfell Hall as Precursors of New Woman Fiction

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Anne Brontë's Agnes Grey and The Tenant of Wildfell Hall were published more than forty years before the appearance of the feminist type that the Victorians called the “New Woman;” yet, both novels contain characteristics of New Woman fiction. By considering how Brontë's novels foreshadow New Woman fiction, the reader of these novels can re-enact the “gentlest” Brontë as an influential feminist whose ideology informed the construction of the radical New Woman. Brontë, like the New Woman writers, incorporated autobiographical dilemmas into her fiction. By using her own experiences as a governess, Brontë constructs Agnes Grey's incongruent social status and a morally corrupt gentry and aristocracy through her depiction of not only Agnes's second employers, the Murrays, but also the morally debauched world that Helen enters upon her marriage to Arthur Huntingdon in The Tenant of Wildfell Hall. Moreover, Brontë incorporates her observations of Branwell's alcoholism and her own religious beliefs into The Tenant of Wildfell Hall. Although Brontë's novels contain autobiographical material, her heroines are fictional constructions that she uses to engage her readers with the woman question. Brontë accomplishes this engagement through her heroines' narrative re-enactments of fictional autobiographical dilemmas. Helen's diary and Agnes's diary-based narrative produce the …
Date: August 2001
Creator: Phillips, Jennifer K.
System: The UNT Digital Library

The Developmental Physiology of the Zebrafish: Influence of Environment and Cardiovascular Attributes

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Temperature effects on the development of the zebrafish embryos and larvae and adults were examined. It was found that the earlier in development a temperature change was performed on an embryo, the more significant the change in survival and/or subsequent development. Thus, viable temperature ranges for zebrafish widened significantly as development proceeded. Adults reared and bred at 25oC produced embryos that were significantly more successful at the lower range of rearing temperatures compared to embryos produced from adults reared at 28oC. The majority of this study focused on the physiological effects of swim training during development in the zebrafish. The earlier in development the zebrafish larvae were trained, the greater the mortality. Trained free swimming larvae had a significantly higher routine oxygen consumption after 11 days of training, and a higher mass specific routine metabolic rate after 8 and 11 days of training. Trained free swimming larvae consumed significantly less oxygen during swimming and were more efficient at locomotion, compared to control larvae. Training enhanced survival during exposure to extreme hypoxia in all age groups. Performance aspects of training were investigated in attempt to quantify training effects and in most cases, trained fish performed significantly better than controls. As blood …
Date: August 2001
Creator: Bagatto, Brian
System: The UNT Digital Library

A meta-analysis of service learning research in middle and high schools.

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This study examines the relationship between service learning innovations and improved academics, self-concept, and social or personal growth in middle and high school students. Meta-Analysis is employed to arrive at effect-size estimates for each construct. A historical overview of service learning is presented and a detailed description of the study selection process is provided. The data revealed a moderate relationship between service learning participation and academics, self-concept and social or personal growth in middle and high school students. The findings are presented, and some appropriate conclusions are drawn. A discussion of the implications of these findings and recommendations for future research are also provided.
Date: December 2001
Creator: White, Amy E.
System: The UNT Digital Library

Teacher Practice, Curriculum, and Children's Moral Development in Buddhist Temple Preschools in Thailand

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This study investigated what constitutes a moral development program in Buddhist temple preschools in Thailand. The researcher employed three qualitative methods: structured, in-depth interviews, observations of teachers' instruction, and document analysis of curriculum guides. Four Buddhist temple preschools were selected as the sites. Participants for interview included three abbots and one head nun, four principals, and twelve teachers. Participants for observations included four teachers of third year classes in each preschool. The study concentrated on four research questions: (a) what are the elements of the character education curriculum? (b) How do teachers teach moral development concepts and skills? (c) What are the teachers' perceptions of the moral development of third year preschoolers? (d) How do teachers assess their pupils' moral development? Key findings for the research questions were: character education was not a subject in the National Preschool Curriculum which was implemented in the Buddhist temple preschools. Core morality was integrated into every topic. The moral behaviors emphasized in the curriculum and the lesson plans included discipline, mindfulness, kindness, helpfulness, patience, honesty, respect, thriftiness, and politeness. The Buddhist concept of the process of moral development includes character education and meditation. The preschoolers were trained to pay respect to teachers and …
Date: December 2001
Creator: Phisalaphong, Rathdow
System: The UNT Digital Library

Topological uniqueness results for the special linear and other classical Lie Algebras.

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Suppose L is a complete separable metric topological group (ring, field, etc.). L is topologically unique if the Polish topology on L is uniquely determined by its underlying algebraic structure. More specifically, L is topologically unique if an algebraic isomorphism of L with any other complete separable metric topological group (ring, field, etc.) induces a topological isomorphism. A local field is a locally compact topological field with non-discrete topology. The only local fields (up to isomorphism) are the real, complex, and p-adic numbers, finite extensions of the p-adic numbers, and fields of formal power series over finite fields. We establish the topological uniqueness of the special linear Lie algebras over local fields other than the complex numbers (for which this result is not true) in the context of complete separable metric Lie rings. Along the way the topological uniqueness of all local fields other than the field of complex numbers is established, which is derived as a corollary to more general principles which can be applied to a larger class of topological fields. Lastly, also in the context of complete separable metric Lie rings, the topological uniqueness of the special linear Lie algebra over the real division algebra of quaternions, …
Date: December 2001
Creator: Rees, Michael K.
System: The UNT Digital Library

Comparative Morphology of Sensilla Styloconica on the Proboscis of North American Nymphalidae and Other Selected Taxa: Systematic and Ecological Considerations.

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Sensilla styloconica on the proboscis of 107 species of North American and tropical butterflies were comparatively studied using the scanning electron microscope. Focus was on 76 species of North American Nymphalidae representing 45 genera and 11 subfamilies. Nomenclature for generalized and specific types of nymphalid sensilla is proposed. Written descriptions and micrographs are presented for each species studied. Morphological features were generally consistent for all or most species within genera and sometimes within subfamilies, with specified exceptions. Statistical analysis revealed significant differences for six of eight variables tested between two distinct feeding guilds of North American Nymphalidae. Average number, density, extent of proboscis coverage with sensilla, their total length, and shoulder spine length were all significantly greater in the non-nectar feeding guild than in nectar feeders, and may indicate adaptation for greater efficiency in feeding on flat surfaces. The greater frequency of apical shoulder spines in non-nectar feeders may represent adaptation for protection of sensory pegs from mechanical abrasion during feeding, or for anchoring the flexible proboscis tip to the surface. Correlation analysis revealed 9 out of 28 positive correlations in nectar feeders and 5 out of 28 in non-nectar feeders. Results of preliminary cladistic analysis were not considered to …
Date: December 2001
Creator: Petr, Daniel
System: The UNT Digital Library

A Novel Phytoestrogen that Acts as an Agonist for Human Estrogen Receptors.

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Estrogen is the natural agonist of the estrogen receptor (ER). However, certain plant-derived compounds or phytoestrogens have been identified that mimic estrogens and act as agonists and/or antagonists of ERs, depending on subtype and target tissue. Understanding how phytoestrogens interact with ERs, and therefore effect the estrogenic response, may prove beneficial in hormone replacement therapy and in the prevention and treatment of hormone-related diseases. Using Thin Layer Chromatography, gas chromatography/mass spectrometry (GC/MS), and proton nuclear nagnetic resonance (HNMR), I identified 4-ethoxymethylphenol (4EM) found in Maclura pomifera. While most phytoestrogens are heterocyclic compounds, 4EM is a simple phenol that acts as an agonist of ER-alpha and -beta in HeLa and MCF-7 cells. To study the effect of 4EM on ER-alpha and -beta activity, I performed transient transfection assays and showed that 4EM activates ER dependent gene transcription in a dose dependent manner in both ER subtypes. Further, 4EM- mediated transcription in ER-alpha, like estrogen, was enhance in the presense of co-activators, SRC-1 (steroid receptor coactivator-1), CBP (CREB binding proteins), and E6-AP (E6-associated protein) and inhibited by trans-4- hydroxytamoxifen (4HT). I found that 4EM was specific for ER and did not activate transcription of the progesterone receptor in HeLa cells.
Date: December 2001
Creator: Pearce, Virginia
System: The UNT Digital Library