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In this narrative, the author reflects on the personal and ethical dilemmas she faces currently in the beginning stages of conducting dissertation research fieldwork, an aspect often glossed over by retrospective accounts. She is conducting ethnography of Nicaraguan labor migrant women working in Costa Rica's coffee agro-industry, with an emphasis on reproductive health and motherhood. In addition to her social position as a Western, advanced graduate student-researcher, Goldade is also a wife and mother, arriving in the field with her baby daughter just under 4 months of age. She grapples with the challenges of negotiating the moral politics of motherhood and ethnography, seeking collaboration among host country nationals and recruiting study participants, as well as the balancing act of working motherhood.

The purpose of these studies was to determine whether the inhibitory effects of short photoperiod exposure on prolactin cell activity in male Syrian hamsters and/or the inhibitory effects of melatonin treatment on the growth and activity of diethylstilbestrol- (DES) induced prolactinomas in Fisher 344 (F344) rats were possibly mediated through alterations in dopaminergic regulatory mechanisms. In both the hamster and the rat, changes in hypothalamic dopamine neuronal activity and changes in pituitary responsiveness to dopamine have been suggested as possible mechanisms in the prolactin-inhibitory effects of light deprivation or melatonin administration. The present studies in the male Syrian hamster addressed two issues. First, it was of interest to determine if anterior pituitaries of long photoperiod-exposed male hamsters possess dopamine receptors, which are presumably necessary for responsiveness to dopamine. This was accomplished by analysis of ³H-spiperone binding to anterior pituitary membranes. Second, possible changes in pituitary sensitivity to dopamine were assessed by comparison of dose response curves for the inhibition by dopamine of prolactin release from hemipituitaries incubated in vitro from both long and short photoperiod-exposed animals over a series of time points from three to fifteen weeks. In the second series of experiments, adult female F344 rats received daily injection of melatonin or saline vehicle. After two weeks, half of the animals were sacrificed for analysis of ³H-spiperone binding to anterior pituitary membranes, measurement of hypothalamic dopamine turnover and analysis of in vitro pituitary sensitivity to dopamine. The remaining animals received subcutaneous implants containing DES and injections were continued on the same schedule until sacrifice four weeks later for measurement of the same parameters. In both the hamster and rat models, treatments exerted profound inhibitory effects on indices of prolactin cell activity. However, these studies provide no evidence for the involvement of altered dopaminergic regulation in the production of such effects. Neither pituitary sensitivity to dopamine in vitro nor hypothalamic dopamine neuronal activity was enhanced by short photoperiod exposure or melatonin treatment. Prolactin-inhibitory effects of these treatments appear to be mediated through as yet unidentified dopamine-independent mechanisms.

A point process model for the packet stream arising in teletraffic processes is the discrete, non-negative integer-valued, stationary process introduced by Neuts and Pearce. In this thesis, we examine an empirical approach to develop a monitoring scheme for that point process. Monitoring is a procedure of tracking a stochastic process to identify quickly the development of anomalous situations in the evolution of that process and detect their assignable causes. Further, a data-analytic scheme to evaluate the order of a Markov chain that quantifies the local dependence embedded in the point process and Walsh spectral techniques are examined.

Teacher incentive systems are of relevance to public as well as private school systems. Educational theorists and practitioners have been striving for a method of motivating teachers to an optimal return on educational investments. Carol Bartell (1988) has outlined five different models of incentive systems, each of which center on factors of motivation. Two of the five models focus on non-monetary incentives, while the remainder hold monetary remuneration as the primary or sole incentive. This study was centralized upon a version of Bartell's (1988) model: the "Professional Responsibility" incentive. The core of this incentive was the attainment and sharing of professional attributes, as teachers assumed added roles within their profession. Multiple responsibilities assisted teachers to identify goals and aspirations, thereby helping teachers in expanding their abilities. The study used the Summer Employment Option Program of the Church of Jesus Christ of Latter-day Saints as a basis for assessing the value of professional responsibility incentives in a private school setting. It was anticipated that if the study provided data which exhibited growth in the target areas provided by the sponsoring agency, then the incentive could be a professional responsibility incentive and of strong value to similar settings in the public as well as the private sphere. The study incorporated the Bush-Gallagher (1985) policy analysis approach to assess the viability of the professional responsibility incentive. Through the policy analysis model, research questions were generated, values were explored, goals and objectives were delineated, and major barriers to implementation were examined. It was discussed, through the policy analysis and the use of qualitative and quantitative measures, that the Summer Employment Option Program fit the model of a professional responsibility incentive. It was found that teachers using the Summer Employment Option Program were, (a) motivated to grow professionally, (b) were better satisfied with their work, and (c) worked harder at program goals. The study was designed to provide a model for other organizations so they can benefit from the mistakes and successes of the summer Employment Option Program's sponsoring agency.

The purpose of this study was to document the construction of subject matter content through the description of daily lesson activities that occurred in two eighth grade Civics classes. Utilizing daily observations, field notes, audio-tapes, and interviews to collect data, this study focuses on how students and teachers work collaboratively during activities in order to construct a "text" of the subject matter of lessons. The metaphor of classroom as text was used as a framework for this study. Participants in this study were two teachers and their students in one section each of an American Civics course. Both classes were observed daily by a non-participant observer over the course of one semester. Field notes and audio-tapes were recorded by the observer during each lesson. Copies of materials and resources used during lesson activities were also collected. Interviews with teachers took place during the summer following the observation semester. Data were analyzed using an adapted version of Doyle's Activity Analysis Procedures (1984). In this procedure data from all data sources except interviews are combined in order to describe individual lesson activities. The focus of analysis was one unit that was taught as part of the curriculum in both classrooms. Results of analysis indicate that teachers and students in the two classrooms constructed different texts of the subject matter of the unit. Though there seemed to be similarities in general structure, the unit as it was enacted in each classroom, reflected differences in what aspects of content were represented, how content was constructed, how teachers and students interacted within the contexts of activities, and how activities were internally structured.

The objective of this research is to present a theoretical framework and to describe a computational representation for the mental models that a manager uses when implementing a strategic plan or when attempting to improve an organization's productivity. A mental model consists of some dynamic internal representation that reflects the essential features and relationships in a corresponding real-world system. An integral part of a mental model includes procedures for examining and manipulating its contents and its structure in order to answer questions about the status of goals or the progress of plans. It is suggested that, for an effective manager, these models incorporate a highly integrated network of concepts and propositional relationships that this manager uses to understand strategies and organizations, to infer relationships among indirectly related concepts, and to initiate communication with other managers. The design for this research includes two case studies which were used to clarify and refine the theoretical concepts about the structure and processing of mental models in strategic management tasks. First, the implementation of a Total Quality Management strategy was studied from the perspective of the Director of Quality Assurance at one division of a large financial services organization. The second study was conducted at a computer manufacturing organization where coordination among functional managers was investigated as they introduced new products to manufacturing. The computational model developed as part of this research, called SPRINT (Strategic Plan and Resource INTegration), is implemented as a frame-based semantic network using a hypertext interface and is programmed in Smalltalk/V286. This model is used to represent some of the knowledge gathered in the case studies as a means to evaluate the adequacy of the representation scheme and to provide insights into the use of a management support system for similar tasks. The contribution of this research consists of: (1) clarifying the notion of mental models as used in managerial decision making; (2) specifying a computational representation which accommodates the theoretical framework and the empirical evidence from these case studies; (3) implementing a computational model which embodies the representation scheme; and (4) suggesting how this computational model would be applicable in a management support system for actual management tasks.

Prior LIFO studies have assumed that a LIFO-use firm will avoid liquidating old low-cost inventory layers due to the resulting tax penalty. However, a LIFO-use firm can actually receive a tax subsidy by liquidating inventory layers in a low marginal tax year, thus avoiding the need to liquidate in future higher tax years. This leads to the prediction that low marginal tax rate LIFO firms account for the majority of LIFO liquidations. Using several measures of a firm's marginal tax rate, and controlling for other potential determinants of LIFO liquidations, this prediction receives strong empirical support. The other potential determinants controlled for which are significantly associated with liquidations include: the probability of violating debt covenants, firm specific sales, industry specific production, investment and financing factors (PIFs) and economy wide factors.