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

Prolonged exposure to microgravity is known to invoke physiological changes which predispose individuals to orthostatic intolerance upon readaptation to the earth's gravitational field. Attenuated baroreflex responsiveness has been implicated in contributing to this inability to withstand orthostatic stress. To test this hypothesis, eight individuals were exposed to 15 days of simulated microgravity exposure using the 6° head-down bed rest model. Prior to, and after the simulated microgravity exposure, the following were assessed: a) aortic baroreflex function; b) carotid baroreflex function; c) cardiopulmonary baroreflex function; and d) the degree of interaction between the cardiopulmonary and carotid baroreflexes.

The purpose of the present cross-sectional study was to examine the effects of ambiguity of loss and type of caregiver-to-patient relationship on anticipatory grief, negative physical and psychological outcomes associated with grief, and boundary ambiguity in family caregivers of chronically ill patients. Questionnaires were completed by 23 parents of ill children and 30 spouses of ill mates. Using an original and a revised concept for level of ambiguity, partial support was found for the prediction that parents and spouses in high ambiguity of loss circumstances would report more anticipatory grief than those in low ambiguity ones. Contrary to prediction, a slight but nonsignificant trend occurred for parents and spouses in low ambiguity situations to report more negative physical and psychological effects associated with grief as well. Level of ambiguity was not found to impact boundary ambiguity as had been hypothesized. Spouses reported more boundary ambiguity than parents, regardless of level of ambiguity of the loss. Contrary to prediction that parents would report less anticipatory grief and more negative physical and psychological outcomes than spouses, generally, no significant differences were found between the two groups. However, using the original concept of ambiguity, parents did tend to recall more past grief than …

In this dissertation the results of Jerrum and Sinclair on the conductance of Markov chains are used to prove that almost all generalized Steinhaus graphs are rapidly mixing and an algorithm for the uniform generation of 2 - (4k + 1,4,1) cyclic Mendelsohn designs is developed.

The purpose of this study was to ascertain the image of the University of North Texas as perceived by the University Administration and Board of Regents, Texas Higher Education Coordinating Baord and selected Legislators, and the Boards of Directors of the Metroplex area Chambers of Commerce. The significance of the study was to contribute knowledge that could be used to construct a more direct and cost effective marketing plan.

Learning styles and readiness for self-directed learning were identified for 125 adult employees enrolled in self-paced training courses. The success of the self-paced instruction was measured by confidence to perform learned skills on the job. Confidence scores were compared across learning style types and self-directed learning readiness. It was concluded that self-paced training programs can be effective for a variety of learning style preferences. Additionally, adult employees who are highly self-directed will experience greater success in self-paced instruction than those less self-directed. The implication for businesses and academic institutions seeking to employ technology based, self-instructional programs is that a return on investment can be maximized by an examination of the target audience. Training programs which are self-paced may not generate the desired success which will translate into effective job performance for those adults who are not ready for self-directed learning.

The problem with which this study is concerned is comparative administrative leadership behavior between municipal and university administrators. The specially designed survey instrument elicited respondents' perceptions of their administrative leadership behavior based on the 12 dimensions of the Leader Behavior Description Questionnaire- XII.

Chronic ventricular sympathectomy elicits changes in the coronary circulation, myocardial oxygen consumption and size of infarction resulting fromcoronary occlusion. These changes indicate a change occurring in the basic metabolism of the heart in response to the removal of its sympathetic nervous input. This hypothesis was tested using two groups of dogs, a shamoperated control and a ventricular sympathectomized group. The sympathectomy procedure was an intrapericardial surgical technique which selectively removes ventricular sympathetic input. Four weeks after surgery, left ventricular tissue samples were obtained and rapidly frozen to -80°C. Selected metabolic variables were then compared between the two groups.

The simplicity and ease of use of the Rasch procedure is a decided advantage. The test user needs only two numbers: the frequency of persons who answered each item correctly and the Rasch-calibrated item difficulty, usually a part of an existing item bank. Norms can be computed quickly for any specific group of interest. In addition, once the selected items from the calibrated bank are normed, any test, built from the item bank, is automatically norm-referenced. Thus, it was concluded that the Rasch quick norm procedure is a meaningful alternative to traditional classical true score norming for test users who desire normative data.

The purpose of this study was to analyze and compare the values, beliefs, and ideas in school reading textbooks (Readers) in Taiwan and in Texas. It intended to examine the social control function of school Readers, with which a culture deliberately molds its young generation. This study employed primarily qualitative methods. The collection of data used the technique of content analysis, student surveys, and teacher expert panel discussions. The analysis of data followed a constant comparative approach. The themes shared by the two sets of Readers included family, friends, humans and living creatures, political ideals, reading/writing, appreciation of nature, science, indomitable spirit, turning danger into safety, setting goals, education, desirable and undesirable qualities or behaviors. Despite the similarities of these themes, the substance or focus of them may vary. The themes unique to the Texas Readers were content knowledge, cultural diversity, dilemma and choice, observations about people, words, tomorrow's technology, winning, and general truth. The themes unique to the Taiwan Readers included life philosophy, learning, necessary difficulties, sensitivity, and military strategies. The theme occurring most frequently in both sets of Readers was the desirable qualities or behaviors. The values advocated in the Taiwan Readers were idealistic and had a society-centered …

There is a limited amount of research dealing with the wealth effects of sale-and-leaseback transactions, but previous research has focused predominantly on the tax effects of these transactions. The results of these studies have often been in conflict with one another. This dissertation shows that tax effects do play a role in determining the wealth effect of sale-and-leasebacks on stockholders, but there exists a framework of finance research that suggests several other factors could play a determining role as well.

The primary purpose of this study was to find the content and form of movies which conform to the taste of the majority of Thai audiences and, at the same time, are universal enough to attract international audiences. Because film is an extension of other art forms, this required extensive research into the roots of Thai performing arts.

This study focuses on clarifying the relationships among decentralization, privatization, and economic development in developing countries.

The study was undertaken: (a) to categorize the contents of educational computing articles using a taxonomy developed by Knezek, Rachlin, and Scannell (1988), (b) to examine the trends in educational computing subject matter addressed in community/junior college journals between 1977 and 1991, and (c) to identify and analyze specific characteristics of contributing authors and their employing institutions which might explain writing and publication biases.

The goal of this thesis is to contribute to the ambitious program of the foundation of developing statistical physics using chaos. We build a deterministic model of Brownian motion and provide a microscpoic derivation of the Fokker-Planck equation. Since the Brownian motion of a particle is the result of the competing processes of diffusion and dissipation, we create a model where both diffusion and dissipation originate from the same deterministic mechanism - the deterministic interaction of that particle with its environment. We show that standard diffusion which is the basis of the Fokker-Planck equation rests on the Central Limit Theorem, and, consequently, on the possibility of deriving it from a deterministic process with a quickly decaying correlation function. The sensitive dependence on initial conditions, one of the defining properties of chaos insures this rapid decay. We carefully address the problem of deriving dissipation from the interaction of a particle with a fully deterministic nonlinear bath, that we term the booster. We show that the solution of this problem essentially rests on the linear response of a booster to an external perturbation. This raises a long-standing problem concerned with Kubo's Linear Response Theory and the strong criticism against it by van …

In "Discourse in the Novel," Mikhail Bakhtin tells us that "Every discourse presupposes a special conception of the listener, of his apperceptive background and the degree of his responsiveness." My study of Wallace Stevens's poetry examines Stevens's "conception of the listener"—in the form of his intratextual readers, their responsiveness, and the shapes that responsiveness takes—and attempts to formulate out of that examination Stevens's theory of reading embodied in his canon of poems.

The study inquires into the dynamic relationship between Protestantism and culture in The Faerie Oueene. The American Protestant theologian Reinhold Niebuhr makes penetrating analyses of the relationship between man's cultural potentials and the insights of Protestant Christianity which greatly illuminate how Spenser searches for a comprehensive religious, ethical, political, and social vision for the Christian community of Protestant England. But Spenser maintains the tension between culture and Christianity to the end, refusing to offer a merely coherent system of principles based on the doctrine of Christianity.

The increase in the number of nontraditional aged undergraduate students (25 yrs. and older) and students transferring between post-secondary institutions has raised the question of whether effective instruction is viewed the same by these different groups of students. This study addressed this question by analyzing the responses of these different groups to 23 instructional questions on a standard faculty evaluation form.

The purpose of this study was to determine the accuracy of advertised reports by computer software companies claiming to improve critical thinking skills.

This study used a posttest only design to determine the effects of a strategic thinking program on the Cognitive Abilities Test (CogAT, Form 4) scores of seventh graders who received direct instruction in Strategic Thinking Skills (STS) with the scores of seventh graders who did not receive direct instruction in STS. The study was conducted in a large suburban middle school in north Texas.

The influence of parental marital status and parental conflict on the separation-individuation process of college students was investigated in the present study. Past studies have suggested that parental divorce and parental conflict accelerate separation. However, no studies have measured more than one dimension of separation-individuation. In this study the process of separation-individuation was operationalized as involving three dimensions: psychological separation from parents (Psychological Separation Inventory); emotional attachments to parents and peers (Inventory of Parent and Peer Attachment); and the development of an identity (Extended Objective Measure of Ego Identity Status). The sample consisted of 120 male and 120 female undergraduates between the ages of 18 and 22, one-half with parents who were married and one-half with parents who had divorced in the last five years. Subjects completed self-report measures of parental conflict, psychological separation, attachment to parents and to peers, and identity status. Predictions that parental conflict would affect students in intact families differently than their peers with divorced parents were not supported. Instead, parental divorce and conflict were found to have different effects on the components of the separation-individuation process. Subjects reporting higher parental conflict levels described more independent functioning, more negative feelings toward parents, less attachment to parents …

In this study, the unique style of percussion writing in the chamber works of George Crumb, written between 1960 and 1980, is examined. The principal aspects examined within this study include: the extended instrumental techniques, the use of percussion within the musical imagery, soloistic treatment, compositional and notational procedures, and specific performance problems pertaining to the chamber work Songs, Drones, and Refrains of Death.

The first objective of this research was to identify whether Asian-Americans having higher than average levels of income and education represent an appropriate target market for four food product categories. Second, the impact of national origin membership, demographic variables, and level of acculturation on food consumption was determined. In addition, perceptions related to sensory and nutritional factors and the cultural acceptability of the products were identified and interpreted to determine if the variables differed among specific groups of Asian-American consumers.

Rolando Hinojosa's Klail Citv Death Trip Series purports to give a picture of life in the Texas Rio Grande Valley from roughly the 1930s to the present. Much of Hinojosa's attention is directed toward the tensions that characterize relations between the mexicano and Anglo cultures. Hinojosa's novel sequence in large part documents the ever-increasing acculturation and assimilation of the mexicano into Anglo society.