This thesis deals with the relationships between covering properties and properties of compatible quasi-uniformities of a topological space. The covering properties considered in this work are orthocompactness, metacompactness and paracompactness; some generalizations of orthocompactness are also defined and studied. / Ph. D.

The objective of this research was to investigate the nature of landowner supply-response behavior as it related to the land conversion process in the rural-urban fringe. Emphasis was placed on the derivation of the farmer's dynamic supply-response curve of agricultural land for urban uses since the nature of this curve has important implications for land-use policy alternatives in fringe areas. It was argued that the aggregate land market approach to land use policy analysis in the rural-urban fringe is generally inappropriate for practical and theoretical reasons. Consequently, a disaggregated micro model based on the proprietary land unit was developed to explain the land conversion process. The theoretical model is composed of three cost and two demand components. The interaction of these components results in a dynamic supply-response curve of agricultural land for urban uses which is discontinuous over a wide range for many classes of landowners. The theoretical model was tested through discriminant analyses of data collected from a study area where there exists heavy urban demand for agricultural land. The data included information on landowners over time, physical characteristics of the tracts of land, transfer information and· various demand variables. Results of the empirical analyses provided support for the hypotheses incorporated into the theoretical model. Specifically, empirical evidence was found to support the hypotheses that (1) individual farmers' supply response curves are discontinuous over a wide range, (2) farmers' fixed capital investment is a primary cause of the discontinuity, (3) farmers with less fixed capital investment will generally have more elastic supply-response curves which are discontinous over a smaller range, and (4) speculators' supply-response curves will generally be highly elastic and continuous. Various implications of the theoretical model for land-use policy analysis and land-use patterns in the rural-urban fringe are discussed. Particular attention was given to an analysis of Virginia's use-value assessment program based on the theoretical model. It was found that such a program will not "save" agriculture in fringe areas but will raise land price and subsidize speculative activities. Such a program might be more successful in achieving its stated goals if it were implemented in areas on the outlying edge of the rural-urban fringe. / Ph. D.

The purpose of this study was to determine appropriate content objectives for a human anatomy and physiology course for associate degree nursing students. To accomplish the purpose,of the study, it was necessary to achieve the following goals: 1. Starting with an initial set of objectives for a course in human-anatomy and physiology for associate degree nursing students, obtain the opinions of three groups of nurse educators in regard to the importance value of each objective. 2. Rank order the objectives according to mean value of importance, based on the ratings given by each group of nurse educators. 3. Determine the extent of agreement of ranking across the three groups of nurse educators. 4. Use the mean ratings of the objectives produced by the three groups of nurse educators to make recommendations concerning the selection of objectives for a course in human anatomy and physiology for associate degree nursing students. / Ed. D.

Since the early 1960s, schools on the 45-15 yearround school calendar have been implemented in an increasing number of school districts throughout the United States. Literature has shown that the success of these programs is related to students' attitudes. The main body of knowledge we have concerning students' attitudes is contained in feasibility studies having limitations. Because of the importance ascribed to students’ attitudes, these limitations must be eradicated as much as possible in order to develop a viable attitudinal assessment instrument to evaluate students' attitudes. The evaluation of students' attitudes with such an instrument is the first step toward providing insight into those variables which are associated with favorable and unfavorable attitudes toward year-round education. The weaknesses in previously developed instruments and the importance of students' attitudes in the success or failure of year-round programs formed the basis for a two-pronged approach to this study. First, an attitudinal inventory was constructed to evaluate students‘ attitudes toward the 45-15 year-round school calendar and second, an identification was made of those personal and school calendar characteristics presumed to influence students' attitudes toward that calendar. A research instrument, developed in accordance with Thurstone's technique, was given to selected students in operational public high schools in the United States employing the 45-15 year-round school calendar. The resulting data were analyzed using SPSS subprograms Condescriptive and Student's t. The results revealed that students' attitudes toward the 45-15 year-round school calendar were more favorable when they: (1) perceive themselves as achieving well; (2) determine their own vacation schedule; (3) have one or both parents in favor of year-round school; (4) have close friends on the same attendance calendar; and (5) can select a September to June calendar or school. The personal and school calendar characteristics determined not to have any significant relationship to students' attitudes toward the 45-15 year-round school calendar were: (1) sex; (2) experience in year-round school; (3) employment; and (4) sibling attendance patterns. / Ed. D.

Firm size, in and of itself, is hardly a "goal" of the regulators. Indeed, the growth of very large firms, and the increase in market concentration that accompanies it, will add to the debate over the adequacy of the regulator's management of the industry. It must be demonstrable that very large firms assist the regulators in attaining some of their espoused goals, goals that they might not attain otherwise. What have we learned? The evidence does not all point in one direction. On the question of whether large firms can deliver their services more efficiently than can small ones, our answer is that scale economies are not as easily demonstratable as others have concluded. Such economies turn out to be crucially dependent on the way in which they are specified in the cost function. An examination of the likely biases of each functional form suggests that only relatively small firms would experience real efficiency gains from growth. Large firms seem to be neither more nor less efficient than their smaller cousins, insofar as private costs reflect public costs. / Ph. D.

The temperature-density equation of Kinetic Theory and the conservative neutron transport equation are studied. In both cases a modified version of the Larsen-Habetler resolvent integration technique is applied to obtain full-range and half-range expansions. For the neutron transport equation the method applied is seen to have notational advantages over previous approaches. In the case of the temperature-density equation this development extends previous results by enlarging the class of expandable functions and has the added advantage of rigor and simplicity. As a natural extension of the Kinetic Theory results, an integral equation for the surface density is derived for half-space problems involving the boundary condition of arbitrary accommodation. / Ph. D.

In-plant biomonitors, controlled by dedicated microcomputers, may ultimately provide detection of developing toxicity and hazardous spills in industrial effluents rapidly enough to prevent serious damage to receiving waters. A computer automated system was developed to continuously monitor spontaneous locomotor activity of eight crayfish. Electric potentials generated by muscular movements of untethered crayfish were detected by external electrodes, amplified, digitized, and analyzed by a hybrid computer network. A microcomputer evaluated the number of peaks produced in the waveforms of eight individual <u>C. acuminatus</u> for successive one-hour intervals. The resultant counts were directly related to locomotor activity. The effectiveness of the crayfish biomonitor in detecting simulated spills of cadmium in the laboratory was determined by 7 experiments with 56 crayfish. Results indicated that crayfish responded to 2.5 and 0.5 mg Cd⁺⁺/l with increased activity, which was detected by the crayfish biomonitor two hours after exposure. A simulated spill of 0.1 mgCd⁺⁺/l was detected by the biomonitor within 113 hours. These results support the assumption that the crayfish activity monitor may be used as a potential tool for water quality management. / Ph. D.

A study was conducted to assess the relationship between the zinc/copper ratio and risk factors (hypertension, obesity, elevated serum cholesterol and triglycerides, cigarette smoking, and exercise activity level) associated with susceptibility to cardiovascular disease. A questionnaire technique for assessment of physical activity was presented. The zinc/copper ratio was determined from the zinc and copper concentrations of hair samples obtained from sixty-four male subjects, ranging in age from 19 to 59 years. Correlation coefficients revealed no discernible relationship between either the zinc and copper content of hair, or the zinc/copper ratio obtained from these values. Serum cholesterol and triglyceride values, zinc concentrations in hair and the zinc/copper ratio were tested for significant differences associated with age. Statistical analysis indicated that these parameters were not significantly different. Such results were attributed to the wide range of variation within groups for this sample population. Data was not supportive of Klevay's altered zinc/copper ratio hypothesis as the major factor in the etiology of cardiovascular disease. / Ph. D.

Two experiments were conducted using newborn colostrum-deprived calves to establish the distribution of uptake of ¹²⁵I- globulin in smail intestine and to investigate effects of added microorganisms on ¹²⁵I-gamma globulin uptake. Ten calves less than 12.5 h of age (X̅ = 7 h) were anesthetized and intestines exteriorized through an abdominal incision. Intestine was ligated into 10 cm segments at 70 cm intervals beginning at the ileocecal junction, injected with ¹²⁵I-gamma globulin in an electrolyte solution and incubated for 1.5 h. One additional segment was formed adjacent to segments 1, 5 and 10 to assess effects of .5 h exposure to ¹²⁵I-gamma globulin on uptake by epithelium. After prescribed gamma globulin exposure, segments were excised, volume of lumen contents, segment weight and tissue activity were determined. Age, birth weight and intestine length were recorded. Location of each segment (PSEG) was expressed as percentage of distance from cecum to abomasum. Uptake was expressed as milligrams gamma globulin internalized per gram of segment tissue. Distribution of gamma globulin uptake after 1.5 h exposure was a cubic function of PSEG. Uptake was greatest In a region 15% of cecumabomasum distance, declining progressively towards the abomasum. After .5 4 exposure, regression of uptake on PSEG was a quadratic function with greatest uptake at 30% of cecum-abomasum distance. Uptake after 1.5 h exposure was greater than after .5 h. In experiment II, 10 calves less than 14 h of age (X̅ = 8.6 h) were anesthetized and intestines surgically exteriorized. Intestine was ligated into segments 10 cm in length at three cm intervals beginning 1.8 m above the ileocecal junction. Seven treatments were assigned in random order to segments in three successive sections of small intestine. Three treatments compared uptake in segments receiving one ml of either live intestine origin bacteria culture, sterile microbiological broth or autoclaved bacteria culture with four h incubation followed by 1.5 h exposure to ¹²⁵I-gamma globulin. Two treatments measured anaerobic microbial growth after four h incubation with one ml of either sterile broth or live bacteria culture. Residual ¹²⁵I-gamma giobulin was measured in segments receiving one ml of sterile broth or live bacteria culture with 5.5 h incubation followed by 15 second exposure to ¹²⁵I-gamma globulin. Measurements were as described for the first 10 calves. Serum corticosteroids, total protein and protein components were measured at O h and 5.5 h later. Uptake was lowest in segments receiving live bacteria as compared to segments receiving sterile inocula. Number of bacteria per gram of segment tissue was negatively correlated with uptake. Low serum corticosteroids were associated with low gamma globulin uptake. Body weight and age were not related to uptake in either experiment.in a decisive manner. / Ph. D.

The purpose of the study was to compare the effects on item bias of conventional testing procedures to the effects of two-stage testing procedures. It is conjectured that much of the measurement error identified as bias can be explained by factors, such as guessing or carelessness, attributable to inappropriate matching of test difficulty level and examinee ability level. Methods for detecting bias based on the-traditional definition of item difficulty fail to separate test characteristics from the ability distribution of the respondent sample. The separation of item and ability parameters, however, is an essential ingredient for an objective definition of bias. Such objectivity in measurement is provided by the Rasch latent trait model, which consequently was selected as the basis for this study. Three definitions of bias were considered, two of which were based on the Rasch model. The analyses were conducted using the scores of random subsamples (n=400 each) of black and white students on items selected from three reading subtests. The two-stage testing procedure was simulated using the real data set by "routing" students to one of three difficulty levels of the subtests based on their Rasch ability estimates as determined by a ten item routing test. Results for the two-stage testing procedure were compared with those from the conventional testing procedure at the subtest level. A reduction in the number of items identified as biased under conditions of appropriate matching of examinee ability levels and test difficulty levels was indicated by these analyses. Although the results are not conclusive, it is felt that individualizing according to the examinee's ability level offers promise in the direction of reading differential cultural measurement error. / Ph. D.