A study was conducted in 1993/94 on a group of 45 women clustered into the Hill, Lake, and Town regions of Kasgunga West sub-location in Homa Bay district, Kenya to assess women’s perceptions of problems and solutions related to fuelwood availability, household food consumption, and women’s time allocation for daily activities, and the relationships between time allocation, fuelwood availability, and household food consumption. Results obtained from the qualitative part of the study showed that 35, 23, and 22% of the respondents perceived that fuelwood collection, child care, and farming activities, respectively, were the most strenuous and time consuming activities of women in the Homa Bay district. The most obvious fuelwood availability problem was inadequate supplies. This caused a shift in the size of collected fuelwood (from large to small and increased usage of agricultural residue for fuel). According to the study, inadequate food is produced in the area and this results in approximately 91% of the staple consumed being bought from the market. The total time spent by respondents for collecting fuelwood was positively correlated with the amount of fuelwood collected (r=0.69) and earnings derived from sale of charcoal (r=0.61). / Ph. D.

This study examines both the urban and rural contexts to determine how context influences the attitudes and perceptions of local officials concerning their participation in the governance of their communities. James Svara’s dichotomy/duality model is used to assess and compare the attitudes and perceptions of a total of ninety-three elected and administrative officials from urban and rural localities located within Virginia. The research indicates that urban elected officials Share attitudes and perceptions that lead to patterns of activity similar to those described in Svara’s dichotomy/duality model. However, rural elected officials share a set of attitudes and beliefs that is markedly different from their urban counterparts. Rural elected officials indicate higher levels of activity in administration and management than did their urban counterparts. Urban and rural administrative officials are characterized by similar perceptions that lead to relatively high levels of activity. The differences in attitudes and perceptions attributable to context in combination with other factors demonstrate the need for both descriptive and normative guides that are sensitive to context. This study proposes a new normative guide for rural officials. This new source of normative guidance promotes the concept and principles of "democratic leadership." This new normative guide directs the rural official to participate in the governance process in such a way as to encourage citizen participation and followership. By encouraging active participation of all interested groups, this new normative guide establishes a means for renewing the publics’ trust in government through its increased involvement in the creation of a truly "public" policy. / Ph. D.

The exclusion of coal fly ash from regulation as a hazardous waste has led to increased interest in returning ash to the coalfields for disposal. Bulk-blending alkaline fly ash with acid forming coal refuse may present a disposal option that aids in the control of acid mine drainage. A preliminary column leaching study examined the leachate quality from acid-forming coal refuse:fly ash blends. Coal refuse (2.2 % total-S), and two refuse:fly ash blends (20% and 33% ash w/w) were packed into leaching columns and leached under unsaturated conditions for over four years. The coal refuse columns acidified quickly, producing peak leachate levels of acidity (pH 1.7), Fe (10,000 mg 1^-1), SO₄<sup-2</sup>(30,000 mg 1^-1), and Mn (300 mg 1^-1). Both ash blended treatments provided alkaline leachate with low metal levels. A second column study used a refuse with higher potential acidity (4% total-S), and two alkaline ash sources; one blended at two rates (20% and 33%) and one at four rates (5%, 10%, 20%, and 33%). Bulk-blended ground agricultural limestone, rock phosphate ore, and topsoil treatments were also studied. The unamended refuse treatment acidified rapidly and produced acidic (pH 1.7) leachates with high peak dissolved metal levels (>15,000 mg 1^-1 Fe; 200 mg 1^-1 Mn). Treatments blended with 33% ash produced alkaline (pH >8.4) leachates with low metal levels (Al <1.0 mg 1^-1; Cu-0.10 mg 1^-1; Fe < 2.0 mg 1^-1; Mn <3.0 mg 1^-1). Treatments containing less ash eventually acidified and ash bound metals (Mn and Cu) were stripped from the ash and eluted in quantities proportionate to the amount of ash in the blend. A field experiment with water sampling lysimeters examined bulk-blended refuse (0.8% S) with two acidic and one alkaline ash. The ash treatments did not produce consistent negative impacts on leachate water quality, and produced positive effects on plant biomass production compared to unamended controls. Overall, the inhibition of pyrite oxidation by high ash blends was attributed to alkalinity effects, chemisorption, decreased hydraulic conductivity, and decreased oxygen diffusion to pyritic surfaces. Ash alkalinity and refuse potential acidity must be balanced for environmental safety in this co-disposal environment. / Ph. D.

Cellular manufacturing is a practical application of group technology in which functionally dissimilar machines are grouped together to produce a family of parts. The fundamental problem of cellular manufacturing system design is the identification of part families and machine cell compositions. This problem is commonly referred to as the Part Family / Machine Cell (PF/MC) formation problem. Given a set of parts, processing requirements, and available resources, the objective of the PF/MC formation problem is to obtain a satisfactory partition of parts into families and machines into cells. The effectiveness of a cellular manufacturing system is sensitive to fluctuations in the demand for products, the product mix, and the availability of resources. This research offers a multi-period formulation of the PF/MC formation problem. It addresses the dynamic nature of the production environment by considering a multi-period forecast of product mix and resource availability during the formation of part families and machine cells. The goal of the multi-period formulation is to obtain a cellular design that performs well with respect to the design objectives over the entire planning horizon. Design objectives of the multi-period formulation of the PF/MC formation problem are the minimization of intercell material handling costs, the minimization of investment in additional machines, and the minimization of the cost of system reconfiguration over the planning horizon. A mathematical model of the problem is developed and a solution procedure is presented based on a genetic algorithm. The advantages of using a genetic algorithm to solve the multi-period PF/MC formation problem include the ease with which alternate design objectives can be incorporated and the ability to generate alternative system designs. The output of the multi-period PF/MC formation methodology developed in this dissertation is a period by period description of the part families and machine cell compositions. Results are presented of a preliminary investigation of the benefits of using a multi-period model versus one that assumes that the product demand, product mix, and available resources remain constant. In the design problems considered, the multi-period approach to solving the PF/MC formation problem resulted in a cellular design that performed the best overall with respect to the design objectives. / Ph. D.

Uterine infections in farm animals are a serious problem in developing countries. Several factors are involved in regulating susceptibility of animals to infections. The experiments conducted with ewes for this dissertation aimed to 1) Investigate the hormonal regulation of uterine immune responses to infections during different stages of the estrous cycle (Exp. 1), and 2) Investigate the ability of uterine proteins, collected during different stages of the estrous cycle, to regulate lymphocyte activity in vitro (Exp. 2). Experiment 1 was a 2 X 2 factorial design, with stage of estrous cycle (follicular vs luteal) and treatment (bacteria vs saline) as main effects. Escherichia coli and A.pyogenes were used for uterine inoculations. Blood was collected, via catheters inserted into the vena cava, twice daily for six days. Estrogens, progesterone, PGF_2α, and PGE₂, were measured in blood, lymphocyte (T- and B) activities were assessed in vitro, and leukocyte differential counts were made. Follicular-phase ewes, under predominance of estrogens, had increased vena caval percentage of lymphocytes and greater T- and B-lymphocyte activity in response to mitogens than luteal-phase ewes, under predominance of progesterone. Concentration of PGF_2α increased in response to bacterial inoculation, but PGE₂ did not affect by treatment. Experiment 2 was a split-plot design, with stage of estrous cycle and status of ewes (intact vs ovariectomized) as main effects. The amount of total proteins in uterine flushings from intact ewes was greater than that from ovariectomized ewes. Two protein peaks were separated on a Sephacryl S-100 column. Peak one had an estimated size of ≤ 1 X 10⁵ Da, and peak two had an estimated size of 12.7 X 10³ Da. Small concentrations of peak one protein from intact follicular-phase ewes enhanced activity of T-lymphocytes in response to mitogen, whereas peak two protein from intact luteal-phase ewes suppressed T-lymphocyte activity. Peaks one and two from ovariectomized ewes suppressed T-lymphocyte activity. In conclusion, the uterus of ewes under the influence of estrogens had enhanced immune capability and was able to secrete immunostimulatory proteins. Ewes under the influence of progesterone had suppressed uterine immune functions. / Ph. D.

Sarcoplasmic reticulum (SR) releases and sequesters calcium during muscle contraction and relaxation. Calcium uptake rates have been shown to respond to high intensity exercise, and we propose this response may be affected by conditioning and dietary lecithin. Ten Quarter Horses performed repeated sprints on a high speed treadmill. Muscle samples were taken before and after exercise from the middle gluteal muscle, and SR vesicles were isolated. Horses were then conditioned for 12 weeks and the experiment was repeated. Calcium uptake was determined spectrophotometrically using antipyralazo IIl, and Ca²⁺- ATPase activity was determined using an enzyme-linked optical assay. Resting calcium uptake rates and Ca²⁺-ATPase activities were greater when the horses were conditioned than when unconditioned (p=.05, p=.004, respectively). After exercise calcium uptake was slower in horses unconditioned (p=.02) or conditioned (p=.002) and this fatigue response to exercise was reduced by conditioning (p=.01). After exercise Ca²⁺-ATPase activity was decreased (p=.007) to 71% of resting activity in unconditioned horses, and to 82% in conditioned horses (p=.001). The same ten horses were divided into two groups and were fed either a conventional diet or a diet with 10% added dietary fat in the form of corn oil/soy lecithin for a 12 week period. The diets were switched and the study was continued for another 12 weeks. Horses were exercised 4 days a week on a high speed treadmill throughout the study. The repeated sprinting experiments, as in the first part of the study, were performed at the end of both 12 week periods. Resting calcium uptake rates tended to be higher (p=.09) when horses were fed the fat modified diet, but decreased to a greater extent with an acute bout of exercise (p=.058). Ca²⁺-ATPase activity was lower after exercise when horses consumed the lecithin (p=.02) and the decrease from resting values was greater (p=.05). These results suggest that high intensity repeated sprinting fatigues SR function in horses, and that conditioning reduces the depression of SR function with exercise. Feeding a lecithin supplemented diet to conditioned horses increases the response of the SR to an acute bout of exercise. / Ph. D.

Zaccaro, Foti, and Kenny (1991) and Rueb and Foti (in press) found a relation between self-monitoring, a measure of response flexibility, and emergent leadership. Walsh (1992) failed to support this hypothesis; however, a relation between self-monitoring and agreement in ratings of perceived leadership was indicated. The implications of inaccurate ratings suggested that an objective measure of leadership was necessary to further explore the nature of the relationship of self-monitoring and leadership, as well as leadership perceptions. The present study re-examined this issue, introducing an objective measure of leadership, and further examined the hypothesis that psychological type may act as a moderator in these relations. Subjects completed the Myers-Briggs Type Indicator, the revised Self-Monitoring scale, and four group tasks. After each task, subjects rated each other on perceived leadership. Results indicated that 65 percent of the variance in general leadership impressions, and 61 percent of the variance in perceived leadership behaviors was stable and due to characteristics of the individual. In addition, it was found that there is a discrepancy between the variance in perceived leadership ratings and the variance in actual leader behaviors. The hypothesis that self-monitoring and emergent leadership are related was not supported. Hypotheses concerning the relationship between self-monitoring and perceptual agreement and self-monitoring and rating accuracy received partial support. Psychological type did not moderate any of the above relations as predicted but did have an effect. Implications for future research were discussed. / Ph. D.

Because of the efficacy of taxol against a wide variety of cancers, the demand for this drug has vastly increased during the last decade. Due to its limited natural supply, a number of alternative sources of taxol continue to be investigated. One approach toward alleviating the taxol supply problem is by the systematic investigation of the structure-activity relationships of the molecule, in order to establish the structural features and functionalities necessary for biological activity. Research efforts during the last decade have led to the establishment of the molecular domains and functionalilties which are crucial for biological activity, however at the inception of this work, the structure-activity relationships of the C-4 position of taxol were unknown. It was thus the major goal of this work to prepare 4-deacetyltaxol, in order to assess the importance of the C-4 acetate for overall activity, as well as to have a template molecule with which to begin studies aimed at determining the effect on activity rendered by replacement of the C-4 acetate with other acyl groups. Preliminary studies of the deacylation and reacylation of baccatin III were carried out in order to find conditions necessary for the preparation of 4-deacetylbaccatin III, and hence 4-deacetyltaxol. 4-Deacetyltaxol has now been prepared from baccatin III via two synthetic approaches and from taxol via one synthetic approach, and has been shown to be significantly less potent than taxol, suggesting that the C-4 acetate is necessary for biological activity. From the investigation of several potential synthetic approaches toward the formation of 4-acyltaxol analogs, one methodology has been developed which has allowed the preparation of 4-acyltaxol derivatives from baccatin III] or the more readily available 10- deacetylbaccatin III. This particular methodology can be extended to the preparation of other 4-acvitaxol or 4-acyltaxotere derivatives. Two C-5a halogenated oxetane ring-opened compounds have been prepared from a 4-deacetyltaxol derivative, offering the opportunity to investigate the potential effects on biological activity generated by modifications to the oxetane ring. / Ph. D.

The operation of the basic shunt system for solar arrays is considered. The system is analyzed for stability with a constant power load. The implications of using switching type shunt elements for high power outputs are investigated. The input filter is shown to affect the closed loop design of the system, as well as its weight. Analysis and modeling techniques are developed for a sequential shunt unit. The analysis of bus impedance and loop gain is verified against measurements on hardware. The factors that affect the design are described. The effect of non-linearities in the system is shown to cause limit cycle operation. For more effective use of the input filters, alternatives to the existing scheme are considered, where the on-off and fine control sections are kept distinct. The basic requirements of the scheme are shown to be the suppression of on-off section current, and the inclusion of hystcresis in the control loop. / Ph. D.

The purpose of this study was to identify and analyze those factors which facilitated or impeded selected community colleges' involvement with customized training, as determined by key administrative personnel of the Virginia Community College System. Identified factors were analyzed to determine their effect on the nature and scope of the customized training offered. This was a qualitative study which consisted of interviewing administrators at three community colleges in Virginia. Site selection criteria which provided variation for analysis purposes were the (a) size of the college, (b) location of the college, and (c) type of business and industry in the college's service region. Thirty preliminary interviews were conducted throughout Virginia and 28 administrators were interviewed at the chosen colleges. The following questions were posed to guide, but not constrain the study: 1. What are the factors that facilitate the Virginia Community College System in offering customized training? 2. What are the factors that impede the Virginia Community College System from offering customized training? 3. What is the relationship between the identified factors and the nature and scope of customized training provided? These 50 minute interviews with the administrators were audio-tape recorded, transcribed using Ami Pro and Wordperfect computer wordprocessor programs, and coded and analyzed using Ethnograph, a qualitative research analysis software program. Factors which emerged as either facilitative or impeditive were (a) leadership, (b) philosophy, (c) policies and procedures, (d) personnel, (e) infrastructure, and (f) resources. Site selection criteria also emerged as factors. These factors were analyzed for each site and across sites. / Ph. D.