Cohesion is a critical area of investigation in the analysis of groups in that at least a minimum amount of cohesion is necessary for group formation and group elaboration. This research project was designed with two related purposes in mind. One purpose was to investigate the effects of a number of independent variables derived from the work of Kanter (1972) on group cohesion. The first model examined the effects of sacrifice, investment, renunciation, mortification, and transcendence on cohesion. On the basis of the results of the first model, a second model was tested in which the variables from the first model in conjunction with an additional independent variable, type of organization, was tested. Regarding the significance of the second model, Hillery (1972) has criticized the field of community theory by stating that there has been a confusion between community as sentiment and community as a human group. Using cohesion as a measure of sentiment, and defining community as communal organizations, the second purpose of this study was to examine the relationship between type of organization and cohesion. The first major finding of this study was that sacrifice is a powerful predictor of group cohesion: it explained 74 percent of the variance in-group cohesion. With the introduction of type of organization into the model, the findings of data analysis showed: (1) the effect of sacrifice on cohesion is stronger communal organizations, (2) among groups with sacrifice scores between 36.6 and 72.8 there is no statistically significant difference between types of organization and cohesion, and (3) among groups with sacrifice scores below 36.2, communal organizations are more cohesive than formal organizations, while among groups with sacrifice scores above 72.8, formal organizations are more cohesive than communal organizations. / Ph. D.

In recent years, there has been a surge of interest in fathers' involvement in childrearing and childbirth. The purpose of this study was to determine how the attitudinal and demographic characteristics of expectant fathers influence their decision about participation vs non-participation in childbirth. A questionnaire which measured sex role attitudes, marital satisfaction, authoritarian parenting attitudes and belief in reciprocity was distributed to 44 men whose wives were in their third trimester of pregnancy. Multivariate and univariate analyses were performed. The univariate analysis was deemed the more appropriate statistic based on unequal sample sizes of participants and non-participants. Differences between the two groups on demographic data were slight. Of all the criterion variables, only belief in reciprocity producted significant differences between groups, p < .05. Belief in reciprocity was the best predictor of fathers' involvement in childbirth. / M. S.

Theories concerning the origin of insect wings and flight are reviewed and a new scenario for their origin proposed. It is suggested that environmental conditions of the small stream were responsible for the evolution of insect flight, and that thermoregulation as well as respiration was important in the preadaptation of wings. The possibility that the five paired convex-concave vein systems each represented a dorsal-ventral blood channel is suggested. Odonate wing vein homology and nomenclatural systems, and phylogeny are reviewed. The process of vein loss is evaluated in the Palaeoptera and a new system of odonate wing vein homologies proposed. The odonate wing mechanism is analyzed and the heretofore overlooked discal nodus characterized. Reevaluation of the comparative morphology of fossil and recent Odonata indicates that Protozygoptera and Protanisoptera represent evolutionary side branches, that the Anisozygoptera is polyphyletic, and that Isophlebiidae and Calopterygoidea are the most generalized Odonata known. Previous scenarios explaining evolution of the unique odonate copulatory process are reviewed. Considering the copulatory behavior of the Calopterygoidea generalized supports evolutionary trends toward male domination and in-flight completion of the process. Assuming direct sperm transfer the original odonate mode requires that originally oviposition be in tandem and that sperm transfer to and from male anterior abdominal sterna be accidental. In contrast, assuming an original indirect transfer of sperm leads to a copulatory sequence similar to that of the Odonata. The proposed scenario differs from others in that extraordinary postures are not envisioned, the process is completed at rest, and the odonate tandem hold is developed prior to copulation. Anisopteran morphology and phylogeny are reviewed and reliable dentification keys developed for North American families and genera, and for 180 anisopteran species collected in Virginia and vicinity. Each species is described and photographed, including seven new species. The biogeography of Virginia Anisoptera is best explained by overlapping biotic regions, the fauna being a mixture of eastern North American, boreal, and tropical elements. New efficient methods for collecting, preserving, and rearing Odonata are described. / Ph. D.

A methodology is developed to determine cost"effective hierarchical computer control network designs for flexible manufacturing systems. By modeling the hierarchical control system (HCS) as a resource allocation problem, an optimal hardware configuration is identified using dynamic programing. Being independent of specific computer hardware technology, the model can address present and future automated manufacturing systems. A simulation model is developed to evaluate operational dynamics of the specified system configuration, analyze HCS component performance characteristics, and evaluate hardware and software in real simulation time. The model also simulates continuous system dynamics, as found in optimal adaptive control systems. / Ph. D.

Aspects of the behavior, biology, and economic importance of carpenter ants were examined. The overall objectives of this study were to determine the economic importance of carpenter ants, and to extend the data currently available on two of the most common and economically important species in the U.S. A survey for the economic importance of carpenter ants indicated that carpenter ants are considered a serious pest by homeowners. The results show that 90% of the homeowners who requested control for carpenter ants during 1980, paid more than $25 for carpenter ant control. The presence of detectable damage was not the definitive factor in the decision to request control. Camponotus ferrugineus and C. pennsylvanicus are similar in their colony foundation and biology. C. ferrugineus required 54 days to produce the first brood and there were 18 workers, including one intermediate worker, in the first brood. Queens of C. pennsylvanicus required an average of 46 days to rear the first brood. Ad libitum feeding did not have a significant effect on colony founding in C. pennsylvanicus. Two queens reared their first brood under artificial light. Food preference studies of C. pennsylvanicus and C. ferrugineus indicated that these two species have similar food preferences. Although honey was preferred to most foods tested, it may not supply sufficient nutrients to ensure proper colony nutrition. C. pennsylvanicus has become well adapted to man-made structures. Some foraging ants are present year round. C. pennsylvanicus optimizes its foraging by exploiting indoor and outdoor foraging sites. The division of labor during nest construction may be based on subcaste. Major workers appear to be responsible for most nest-building in mature colonies. / Master of Science

The objectives of this study included the development of a classification system for the restaurant industry in Virginia and the provision of an operating data base to be used in the future to asess annual changes and mate trend comparisons. A questionnaire was mailed to 2,864 restaurant operations which were randomly selected from the total population of restaurants in Virginia. Demographic data, as well as financial information was collected from a total of 120 respondants. Results for the entire sample were reported at the .1 level of confidence. Operating characteristics, ratios, and a sample Profit and Loss statement was reported for the entire sample. A classification system was developed and the sample was broken down according to it. This system includes major class divisions for type of restaurant, type of management, total sales volume, and general location. Results are compared to other sources of information pertaining to the restaurant industry in Virginia. This study provides industry members with a source of comparative information. It is also useful as a data base upon which future comparisons can be made utilizing the classification system. / M. S.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

To determine how many changes in proteins occur during the cell cycle of a primitive eukaryote <i>Physarum polycephalum</i>, total plasmodial proteins were resolved by two-dimensional gel electrophoresis and visualized by a sensitive silver stain. The results indicate that most proteins do not change in concentration during the cell cycle. The one protein which changed consistently on the gels had a 32,000 molecular weight and isoelectric point of 4.9. This protein increased in concentration during early prophase, peaked in metaphase and decreased by a factor of five by one hour after metaphase. The identity of this protein is not known. Four forms of actin were purified and identified on two-dimensional gels. Their molecular weight was 43,000 with three isoelectric points near 4.7 and one at 5.1. All four forms bound to DNase I agarose. The amino acid composition of <i>Physarum</i> actin was very similar to that of rabbit actin, also containing a characteristic modified amino acid, 3-methyl histidine. All four forms were also identified in gels of nuclear proteins. Five species of thymidine kinase were identified on isoelectric focusing gels from their characteristic activities. TIP inhibited all five forms. The isoelectric points of these forms were 5.9, 6.4, 6.7, 6.9 and 7. 1. The four most acidic forms first appear about one hour before metaphase, peak in telophase and decline during S phase. The 5.9 form is the first to decrease in activity followed by the 6.4 and 6. 7 forms. The activity of the 7.1 form did not change significantly during the entire cell cycle. / Ed. D.

Let G be a finite connected graph. The circularity of G has been previously defined as σ(G) = max{r ε N| G has a circular covering of r elements, each element being a closed, connected subset of G containing at least one vertex of G}. This definition is known to be equivalent to the combinatorial description, σ(G) = max{r ε N| there is an admissible map f:V(G)→A(r)}. In this thesis, co-admissible maps are introduced and the co-circularity of a graph, G, is defined as η(G) = max{n ε N| there is a co-admissible map g:V(G)→Z_n}. It is shown that σ(G) = 2η(G) or 2η(G) + 1. It is also shown that if G is a graph and g:V(G)→Z_n is a co-admissible map, then G contains a cycle, J, called a co-admissible cycle, for which g:V(J)→Z_n is also co-admissible. Necessary and sufficient conditions are given for extending a co-admissible map on a cycle of a graph to the entire graph. If G is a graph with σ(G) = r, it is shown that any suspended (v,w)-path P in G induces, under any admissible map f:V(G)→A(r), either at most four elements of Z_r or every vertex of P with valency two induces exactly two elements of Z_r not induced by any other vertex of G. Finally it is shown that if G is a planar graph and if g:V(G)→Z_n is a co-admissible map, then any planar representation of G has exactly two faces bounded by co-admissible cycles. / Doctor of Philosophy