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The Effect of Attachment on Preschooler's Emotion Understanding

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The purpose of this study was to identify the relationship between attachment and emotion understanding in preschoolers. Data was collected from 16 preschool children and their mothers recruited from a private learning center in a downtown metropolitan area. Attachment was measured by use of the Attachment Q-sort, 3.0 (Waters, 1995), while emotion understanding was assessed through use of Denham's (1986) affective perspective-taking task and interviews of children concerning naturally occurring emotions and emotion causes (Fabes et al., 1991). Results included a significant correlation (p < .05) between secure attachment and preschooler's ability to decipher the cause of another's emotion; however, a significant correlation was not found between secure attachment and preschooler's perspective-taking ability or ability to name other's emotions. Thus, conclusions about the impact of attachment upon emotion understanding were mixed, and more research on the subject was implicated.
Date: December 2000
Creator: Hernandez, Jennie R.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Sarah T. Hughes: Her Influence in Texas Politics

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Conservative males traditionally dominated Texas politics. In 1930, however, Sarah T. Hughes, a liberal woman from Maryland, began a spectacular career in state politics despite obstacles because of her gender and progressive ideas. First elected to the Texas Legislature in 1930, she remained active in politics for the next fifty years. Hard work, intelligence, and ability allowed her to form solid friendships with Texas's most powerful politicians. She became the first woman in Texas to hold a district judgeship, the first woman from Texas appointed to the federal bench, and the only woman to swear in a U.S. president. Hughes profoundly influenced state politics, challenging the long-standing conservative male domination. She helped to create a more diverse political field that today encompasses different ideologies and both genders.
Date: December 2000
Creator: Justiss, Charnita Spring
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Alternative Information Processing Formats for Overcoming Information Processing Deficits in Senior Adults

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The objective of this study was to examine the effectiveness of alternative advertising presentation formats, and the quantity of information presented in advertisements in overcoming possible information-processing deficits in senior adults that could affect their recall of ad attributes and brand name, the cognitive responses generated, and attitude toward the ad. In addition, the study examined the effectiveness of retirement status as a classification or segmentation variable in comparison with the use of the more traditional classification variable, chronological age. A convenience sample of senior adult volunteers from church groups, social clubs, and civic organizations from the local area were randomly assigned to one of nine experimental conditions. The experiment utilized a simulated magazine to test the effects of presentation formats (3 levels), and quantity of information (3 levels) on senior adult's recall, cognitive responses and attitude toward the test ads. Covariates (gender, wealth, education, activity level, health, and income) were used to reduce variance. The findings clearly indicate that the presentation format of the can ad adversely affected the memory of some senior adults. In addition, the results were significantly different across the different age levels. Retirement status was less beneficial than chronological age in the current study, but …
Date: December 2000
Creator: Muller, Lynn F.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Effects of Reinforcement History on Stimulus Control Relations

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Ray (1969) conducted an experiment on multiple stimulus-response relations and selective attention. Ray's (1969) results suggested that stimulus-response relations function as behavioral units. McIlvane and Dube (1996) indicated that if stimulus-response relations are behavioral units the effects of environmental variables on stimulus-response relations should be similar to the effects of environmental variables on single response topographies. This experiment analyzed the effects of reinforcement history on the probability of stimulus-response relations with differing reinforcement histories. In separate conditions random-ratio schedules of reinforcement were contingent on each of four discriminated responses. To assess the effects of reinforcement, during test conditions stimuli controlling different topographies were present concurrently in composite form. Results show that reinforcement history affects the probability of each response topography and that the association between response topographies and their controlling stimuli tends to remain constant throughout variations in reinforcement probability.
Date: December 2000
Creator: Reyes, Fredy
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Effect of Engineered Surfaces on Valve Performance

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Performance of air operated valves is a major maintenance concern in process industries. Anecdotal information indicates that reliability of some high maintenance valves has been improved by using an ion deposition process to achieve engineered surfaces on selected components. This project compared friction for various surface treatments of selected valve components. Results indicate valve performance may be slightly more consistent when an engineered surface is applied in the valve packing area; however surface treatment in this area does not appear to have a dominant affect on reducing valve friction. Results indicate a linear relation between stem friction and torque applied to packing flange nuts, and even after a valve is in service, controlled packing adjustments can be made without significantly changing valve stroke time.
Date: December 2000
Creator: Pope, Larry G.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Bird Bones and a Hatched Egg

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A fifty page manuscript of poetry and a critical introduction detailing the poet's aesthetics. Using the idea of the double-image and eroticism, the poet places her work in the category of the surreal. She describes the process of writing poetry born of fragmentary elements as a feminist emergence of agency. The manuscript is composed of four sections, each an element in the inevitable breakdown of a love relationship: meeting, love-making, birth of a child, death. Quotes from various authors of anthropological and fictional texts begin each section to reinforce thematic structure in a process of unveiling the agency of the narrator. The poems are organized as a series, beginning and ending with sequence poems.
Date: December 2000
Creator: Skebe, Carolyn Alifair
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Academic Dishonesty: Attitudes and Behaviors of Fundamentalist Christian College Students

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This study was designed to examine: (1) the extent to which cheating occurs in fundamentalist Christian colleges; (2) the attitudes of fundamentalist Christian college students toward cheating; (3) attitudes of fundamentalist Christian college students toward cheating among their peers; (4) the kinds of cheating practices of fundamentalist Christian college students; (5) the degree to which students engage in neutralizing behavior to justify cheating; (6) differences in cheating behaviors according to gender; (7) differences in cheating behaviors according to ethnicity; and (8) differences in cheating behaviors according to the length of duration of Christian commitment. Based upon the responses of 337 students attending 3 different Christian colleges, it was concluded that: (1) most Christian fundamentalist students do not engage in cheating; (2) respondents believe that each of 17 self-reported cheating behaviors are serious forms of cheating; (3) respondents are unlikely to report cheating among peers; (4) plagiarism is the most common cheating behavior; (5) most respondents justify cheating on the basis of the workload at school and the pressure to obtain good grades; (6) there are no differences in cheating behavior according to gender; (7) there are differences in cheating behavior according to groups; and (8) most respondents do not cheat …
Date: December 2000
Creator: Sunday, William G.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Diphosphine Ligand Activation Studies with Organotransition-Metal Compounds

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Thermolysis of CoRu(CO)7(m -PPh2) (1) in refluxing 1,2-dichloroethane in the presence of the diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) furnishes the new mixed-metal complexes CoRu(CO)4(μ -P-P)(μ -PPh2) [where P-P = bma (3); bpcd (6)], along with trace amounts of the known complex CoRu(CO)6(PPh3)(μ -PPh2) (4). The requisite pentacarbonyl intermediates CoRu(CO)5(μ -P-P)(μ -PPh2) [where P-P = bma (2); bpcd (5)] have been prepared by separate routes and studied for their conversion to CoRu(CO)4(μ -P-P)(μ -PPh2). The complexes 2/3 and 5/6 have been isolated and fully characterized in solution by IR and NMR spectroscopy. The kinetics for the conversion of 2→3 and of 5→6 were measured by IR spectroscopy in chlorobenzene solvent. On the basis of the first-order rate constants, CO inhibition, and the activation parameters, a mechanism involving dissociative CO loss as the rate-limiting step is proposed. The solid-state structure of CoRu(CO)4(μ -bma)(μ -PPh2) (3) reveals that the two PPh2 groups are bound to the ruthenium center while the maleic anhydride π bond is coordinated to the cobalt atom. Thermolysis of the cluster Ru3(CO)12 with the bis(phosphine)hydrazine ligand (MeO)2PN(Me)N(Me)P(OMe)2 (dmpdmh) in toluene at 75°C furnishes the known clusters Ru4(CO)12[μ -N(Me)N(Me)] (9) and Ru3(CO)11[P(OMe)3] (10), in addition to the new …
Date: December 2000
Creator: Wang, Jiancheng
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Work in the calling in Max Weber's Protestant ethic thesis

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Objectives. Scholars have debated Max Weber's theory of the relationship between religion and capitalism for almost 100 years. Still, the debate is clouded by confusion over Weber's claims about religious doctrine and over the supporting evidence. The purpose of this study is to clarify Max Weber's claims regarding the concept of the calling and the related "anti-mammon" injunction and concept of "good works" and substantiate with historical evidence the religious doctrine Weber describes. Methods. Comparative analysis of early Protestant Lutheran and Calvinist documents from the sixteenth and seventeenth centuries was used to flesh out a history of ideas to determine whether evidence exists to support Weber's claims related to religious doctrine. Results. Historical analyses revealed that the concept of the calling pre-dated Luther in the Bible. Luther's innovation was not in his use of the word beruf but in his application of the concept of the calling to the common people and his teaching of that idea. The idea of sanctified work was key in both Lutheran and Calvinist documents. There was an increased emphasis on work and encouragement to accumulate wealth in Calvinist documents. Conclusion. Weber's etymological evidence surrounding Martin Luther's use of the word beruf in his German …
Date: December 2000
Creator: Schindley, Wanda Beatrice Higbee
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Juvenile Justice Sentencing: Are There Alternatives?

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Research indicates that states have implemented juvenile justice reforms to enact harsher punishments, to transfer greater numbers and younger juvenile offenders to adult criminal court, and to restrict discretion of the juvenile court judges. Social science studies have found that harsher punishments, transfers to adult criminal court and other measures do not work, but that comprehensive approaches which address the numerous major factors contributing to juvenile offending have been successful. This study examined the legal status of the juvenile justice system by focusing upon ten diverse sample states and analyzed the social science research on factors contributing to juvenile offending and on prevention, treatment, and rehabilitation approaches. The study was accomplished by legal research, qualitative social science research, and analysis of both. Findings indicated: a) state statutes require and allow adult punishment of juvenile offenders, transfer of juvenile offenders to adult criminal court, and direct filing of charges against juveniles in adult criminal court; most states begin these proceedings at age 14, some have no age minimum; b) social science research indicates numerous factors contribute to juvenile offending with most of the factors categorized into the major factors of early antisocial behavior, deviant peers, parents and family, sociomoral reasoning, biological …
Date: December 2000
Creator: Youngblood, Michelle K.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

The Effects of Color Concentrate in Polyolefins.

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Throughout history consumer products were generally manufactured from wood and metal. They either had to hold their natural color or become subject to painting. When plastics entered the industry, it was recognized for its ease of shaping, re-usability, physical properties and its low cost. One of plastics' greatest benefits is its ability to hold a given color from within allowing it to avoid use of paint. This paper will give a brief overview on the effects of pigments when incorporated in a polyolefin. It will provide a classification of the main types of pigments and how each effect the properties of the product through: crystallization, weatherability, opacity, coloristic values and of course viscosity.
Date: December 2001
Creator: Flora, Paul
Object Type: Thesis or Dissertation
System: The UNT Digital Library

The Effect of Punishment Threat on Children's Ability to Resist Temptation to Transgress and Lie

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Children's response to a resistance-to-temptation (RTT) task was investigated under three punishment threat conditions: negative consequence, removing an anticipated reward, and no explicit punishment. Ninety first and second graders participated in the RTT task and seventy-three parents completed the Behavior Assessment System for Children and the Psychopathy Screening Device. As only 4% of children transgressed, results are unclear. Hypotheses tested using approximations of transgression showed no differences in RTT. Children with temperaments characterized by hyperactivity, impulsivity, attention problems, and conduct problems (HIA-CP) had the highest levels of psychopathic traits compared to all others. In addition, spanked children were rated as having significantly more behavioral problems than non-spanked children. Limitations of the current study and suggestions for future research are discussed.
Date: December 2001
Creator: Collins, Michelle
Object Type: Thesis or Dissertation
System: The UNT Digital Library

An Etiology of Juvenile Homicide in Dallas, Texas: 1988-1997

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This research analyzed all juveniles involved in a homicide, both victims and offenders, in the city of Dallas, Texas from the years 1988 through 1997. This study addressed several research questions including the identification of risk factors common to both victims and offenders. Data for this study was obtained from the homicide files of the Dallas Police Department. The findings in part identify specific profiles of the victims and offenders, as well as identifying comparisons of risk factors between the two groups. Also identified are the relationships between the offenders and victims. Conclusions from this research present implications for law enforcement agencies, as well as furthering the etiology of juvenile homicide.
Date: December 2001
Creator: Haynes, Joseph
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Mechanisms of Methoxide Ion Substitution and Acid- Catalyzed Z/E Isomerization of N-Methoxyimines

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The second order rate constants for nucleophilic substitution by methoxide of (Z)- and (E)-O-methylbenzohydroximoyl fluorides [C6H4C(F)=NOCH3] with various substituents on the phenyl ring [p-OCH3 (1h, 2h), p-CH3 (1g, 2g), p-Cl (1f, 2f), p-H (1e, 2e), (3,5)-bis-CF3 (1i, 2i)] in 90:10 DMSO:MeOH have been measured. A Hammett plot of these rate constants vs σ values gave positive ρ values of 2.95 (Z isomer) and 3.29 (E isomer). Comparison of these rates with methoxide substitution rates for Omethylbenzohydroximoyl bromide [C6H4C(Br)=NOCH3] and Omethylbenzohydroximoyl chloride [C6H4C(Cl)=NOCH3] reveal an element effect for the Z isomers of Br:Cl:F(1e) = 2.21:1.00:79.7 and for the E isomers of Cl:F(2e) = 1.00:18.3. With the p-OCH3-imidoyl halides the following element effects are found: Br:Cl:F(1h) = 2.78:1.00:73.1 for the Z isomer and Br:Cl:F(2h) = 1.97:1.00:12.1 for the E isomer. Measurement of activation parameters revealed ∆S≠ = -17 eu for 1e and ∆S≠ = -9.9 eu for 2e. Ab initio calculations (HF/6-31+G*, MP2/6-31+G*//HF/6-31+G*, B3LYP/6- 31+G*//HF/6-31+G*, HF-SCIPCM/6-31+G*//HF/6-31+G*) were performed to define the reaction surface. These calculations demonstrate a relatively large barrier for nucleophilic attack in relation to halogen loss and support the experimental findings that this reaction proceeds by an addition-elimination mechanism (AN# + DN). The imidoyl fluorides have been used to synthesize …
Date: December 2001
Creator: Dolliver, Debra D.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Development of a Pre-Impact Environmental Site Characterization for the Bryan Mound, Texas Strategic Petroleum Reserve

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This thesis presents a model for developing site-specific contingency plans to be used during spill response, remediation, and post-spill monitoring using the Strategic Petroleum Reserve's Bryan Mound site as a case study. Bird and vegetation observations provide baseline data for biological conditions, and sediment sampling for total petroleum hydrocarbons serves as a chemical component of the model. Results demonstrate previously unknown conditions that would hinder remediation and affect the persistence of petroleum contaminants. Results also established previously unmapped dominant bird and vegetation types likely to be impacted by a spill at the site. This model points to a reconsideration of individual facilities' responsibilities when planning for large-scale disasters and protecting the sensitive ecosystems surrounding their sites.
Date: December 2001
Creator: Hernandez, Sylvia A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Selected Songs for Chamber Winds and Soprano: Rediscovering a Forgotten Repertoire of John Philip Sousa

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For over one hundred years, the music-going public has reflected on the life and influence of America's “March King,” John Philip Sousa. His popularity as a bandleader was unprecedented, and his reputation as an entertainer captivated the imagination and intrigue of a nation. Sousa's fame was attained through the high standards showcased by his unparalleled concert organization, the Sousa Band. He is interminably linked to the march, and for his seventy-seven years he proved to be its prolific and outspoken champion. Sousa's songs, however, were among his favorite works, and their presence on concert programs reinforced a variety of programming that was the hallmark of his success. The Sousa Band served as a cultural and musical ambassador, and annual transcontinental tours brought music to people where they lived. Sousa's songs were highly anticipated concert features, and were presented by soprano soloists known as the “Ladies in White.” A chamber winds instrumentation, rather than employment of the full-forces of the Sousa Band, allowed for an appropriate musical balance between instruments and voice. The “Forgotten Songs of John Philip Sousa Project” involved the research, editing, and performance of songs housed in the Sousa Archives for Band Research at the University of Illinois. …
Date: December 2001
Creator: Hemberger, Glen J.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Characterization of Moraxella bovis Aspartate Transcarbamoylase

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Aspartate transcarbamoylase (ATCase) catalyzes the first committed step in the pyrimidine biosynthetic pathway. Bacterial ATCases have been divided into three classes, class A, B, and C, based on their molecular weight, holoenzyme architecture, and enzyme kinetics. Moraxella bovis is a fastidious organism, the etiologic agent of infectious bovine keratoconjunctivitis (IBK). The M. bovis ATCase was purified and characterized for the first time. It is a class A enzyme with a molecular mass of 480 to 520 kDa. It has a pH optimum of 9.5 and is stable at high temperatures. The ATCase holoenzyme is inhibited by CTP > ATP > UTP. The Km for aspartate is 1.8 mM and the Vmax 1.04 µmol per min, where the Km for carbamoylphosphate is 1.05 mM and the Vmax 1.74 µmol per min.
Date: December 2001
Creator: Hooshdaran, Sahar
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Music preferences, music and non-music media use, and leisure involvement of Hong Kong adolescents.

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The study sought to determine the relationships of preference responses to grade, gender, familiarity, musical training, peers'/parents' listening habits, music media use, and listening contexts. Grade six through nine Hong Kong students (N = 310) completed the audio preference test followed by verbal responses to training, peers'/parents' preferences, leisure/music media involvement, and listening context. Results indicated: The preferred genres, in descending order, were Western pop/rock, Cantopop/rock, Western classical; the disliked genres were jazz, Chinese, and non- Western/non-Chinese. Preference correlated strongly with genre familiarity. Pop genres were the most familiar to all adolescents. The students' preference toward Western pop/rock and Cantopop/rock associated with several listening contexts: solitary listening, having great freedom to choose one's desired music for listening, listening to music in one's room, and listening to music as background activity. The adolescents expressed that their leisure activities were spent with their family and friends. However, they made it clear that music listening was a personal activity that very likely was listened to alone. On all listening occasions, the girls exhibited a more positive response than the boys did. With four to five hours daily leisure time, the adolescents watched TV for three to four hours while spending less than two …
Date: December 2001
Creator: Hui, Viny Wan-Fong
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Mineral-filled polypropylene: Improvement of scratch resistance

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A potential alternative to acrylonitrile-butadiene-styrene (ABS) and polycarbonate+ABS (PC+ABS), pigmented mineral-filled polypropylene (PP) finds an opening in automotive interior components such as instrument panels, knee bolsters, consoles, etc. Because of the lack of surface aesthetics, pigmented mineral-filled PP is experiencing a limitation to its acceptance in many applications. This study focuses on exploring various mineral fillers and additives in polypropylene to provide a material with enhanced scratch resistance. Several physical properties including Rockwell and Shore D hardness are investigated, and it is determined that Filler W improves scratch resistance. It is also determined that Filler T-filled-PP has poor scratch resistance even with the addition of a lubricant.
Date: December 2001
Creator: Khatib, Jamal F.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

A laboratory course in experimental genetics for the biology major.

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This manual has been designed for a class of twenty- four students concurrently enrolled in the lecture course. The laboratory aids in the learning process and fosters an interest in the science of genetics. This manual and the experiments contained within are both informative and fun. The manual correlates with and expands upon the genetics course. Each investigation, with the exception of the Drosophila melanogaster project, can be completed in a 3-4 hour timeframe. This manual provides a “hands on” experience of theories simply discussed in the lecture course. This manual is intended to be a one-source manual where each investigation is designed to include an adequate introduction. Special attention has been given for each investigation with both the student and instructor in mind.
Date: December 2001
Creator: Lux, Melissa McNeil
Object Type: Thesis or Dissertation
System: The UNT Digital Library

The Effects of Web-Based Learning Versus Traditional Instructor-Based Learning on Student Knowledge and Satisfaction Based on Student Learning Styles

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The purpose of this study was to compare the effects of Web-based learning (WBL) versus those of traditional instructor-based learning (IBL) on student knowledge and satisfaction based on student learning styles. Other goals were to determine if WBL is more effective for those with a particular learning style. The study examined a sample of undergraduate students who were enrolled in the college algebra offered as both oncampus instructor-based (traditional) and Web-based at the university of North Texas (UNT). A total of 36 Web-based students and 58 instructor-based students participated in this study. This study utilized a posttest-only intact group. The Kolb Learning Style Inventory (LSI) measured the learning styles of students. This study used learning methods (Web-based learning (WBL), instructor-based learning (IBL)), and learning styles (Diverger, Converger, Assimilator, and Accommodator) as independent variables. Student knowledge and student satisfaction was measured at the end of the course as independent variables. Based upon the results of the LSI, post-learning exam, and satisfaction a series of two-way analysis of variance (ANOVA 4x2) techniques and independent variable tests was used for each of the dependent variables, knowledge and satisfaction, based on a student's learning styles. The results revealed that students' learning styles were statistically …
Date: December 2001
Creator: Manochehri, Naser
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Quantization Dimension for Probability Definitions

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The term quantization refers to the process of estimating a given probability by a discrete probability supported on a finite set. The quantization dimension Dr of a probability is related to the asymptotic rate at which the expected distance (raised to the rth power) to the support of the quantized version of the probability goes to zero as the size of the support is allowed to go to infinity. This assumes that the quantized versions are in some sense ``optimal'' in that the expected distances have been minimized. In this dissertation we give a short history of quantization as well as some basic facts. We develop a generalized framework for the quantization dimension which extends the current theory to include a wider range of probability measures. This framework uses the theory of thermodynamic formalism and the multifractal spectrum. It is shown that at least in certain cases the quantization dimension function D(r)=Dr is a transform of the temperature function b(q), which is already known to be the Legendre transform of the multifractal spectrum f(a). Hence, these ideas are all closely related and it would be expected that progress in one area could lead to new results in another. It would …
Date: December 2001
Creator: Lindsay, Larry J.
Object Type: Thesis or Dissertation
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
Object Type: Thesis or Dissertation
System: The UNT Digital Library

The Stopping of Energetic Si, P and S Ions in Ni, Cu, Ge and GaAs Targets

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Accurate knowledge of stopping powers is essential for these for quantitative analysis and surface characterization of thin films using ion beam analysis (IBA). These values are also of interest in radiobiology and radiotherapy, and in ion- implantation technology where shrinking feature sizes puts high demands on the accuracy of range calculations. A theory that predicts stopping powers and ranges for all projectile-target combinations is needed. The most important database used to report the stopping powers is the SRIM/TRIM program developed by Ziegler and coworkers. However, other researchers report that at times, these values differ significantly from experimental values. In this study the stopping powers of Si, P and S ions have been measured in Ni, Cu, Ge and GaAs absorbers in the energy range ~ 2-10 MeV. For elemental films of Ni, Cu and Ge, the stopping of heavy ions was measured using a novel ERD (Elastic Recoil Detection) based technique. In which an elastically recoiled lighter atom is used to indirectly measure the energy of the incoming heavy ion using a surface barrier detector. In this way it was possible to reduce the damage and to improve the FWHM of the detector. The results were compared to SRIM-2000 predictions …
Date: December 2001
Creator: Nigam, Mohit
Object Type: Thesis or Dissertation
System: The UNT Digital Library