No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 117-125). Also available via the Internet.

Thesis (M.S.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed Aug. 20, 2007. Includes bibliographical references (p. 46-54).

In order to compare the population dynamics of P elements in the sibling species D. melanogaster and D. simulans, three sets of studies were performed. In a series of comparative mixed population experiments, P-M mixed populations of D. melanogaster evolved into P or Q populations, depending on the strength of the P strains used as the original parental strains. However, no mixed populations of D. simulans evolved into P populations; even when the strongest P strains of D. simulans were used, all mixed populations evolved into Q or M' populations. Using an excision assay system, excision frequencies in a variety of strains of D. melanogaster and D. simulans were measured. On average, excision frequencies of P elements from plasmids were significantly lower in D. simulans than in D. melanogaster. In addition, there were no statistically significant correlations between GD sterility and excision frequencies. Using single neomycin -marked P elements, transposition frequencies of P elements were compared in D. melanogaster and D. simulans. As with excision frequencies, transposition frequencies were lower in D. simulans than in D. melanogaster. In addition, the position of the original insertion site had a strong effect on transposition frequency. All of these three experiments showed significantly lower average activity of P elements in D. simulans than in D. melanogaster. This consistency suggests that the three sets of results were influenced either directly and/or indirectly by common factors, such as host-encoded factors. Therefore, differences in the activity of P elements in these two species may be influenced by different host-encoded factors. The absence of P elements in natural populations of D. simulans may also be explained by the presence of different host factors.

Temperate zone bats are subject to serious energetic constraints due to their high surface area to volume relations, the cost of temperature regulation, the high metabolic cost of flight, and the seasonality of their resources. To my knowledge, there are no individual-based mathematical models for any bat species. The model developed here for a female bat is primarily based on life history and energetics. It describes the growth of an individual female bat using a system of differential equations modeling the dynamics of two main compartments: storage (lipids) and structure (proteins and carbohydrates). The model is parameterized for the little brown bat, Myotis lucifugus, because of information available on energy budgets and changes in body mass throughout its life history. However, with appropriate modifications the conceptualization might be applied to other species of bats with similar life histories. The dynamic estimates of daily energy budgets resulting from the model reasonably compare to previous estimates obtained through different methodologies. Sensitivity analysis using statistical screening design techniques identifies the individual parameters driving the model output and indicates the individual characteristics that might play an important role in survival, reproduction, and consequently in population dynamics. The individual model is used to test hypotheses related to strategies used by temperate bats to meet their energy demands. A complete corroboration of the model is not possible due to the lack of a data set independent of that used to construct and calibrate the model. The individual model is integrated into a structured population model. Characteristics of the individuals determine the structure and, subsequently the dynamics of the population. This methodology uses and integrates the information on bat biology and physiology that has been collected primarily at the individual level. Survival and reproductive rates estimated from simulated populations under varying density dependence are comparable to those reported in the literature for natural populations of M. lucifugus. The population model provides insight into possible regulatory mechanisms of bat population sizes and dynamics of survival and extinction. A better understanding of population dynamics can assist in the development of management techniques and conservation strategies, and to investigate stress effects.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 50-61). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 111-121). Also available on the World Wide Web.

Non-negative matrices arise naturally in population models. In this thesis, we look at the theory of such matrices and we study the Perron-Frobenius type theorems regarding their spectral properties. We use these theorems to investigate the asymptotic behaviour of solutions to continuous time problems arising in population biology. In particular, we provide a description of long-time behaviour of populations depending on the nature of the associated matrix. Finally, we describe a few applications to population biology. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2010.

No description available.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Charles E. Epifanio, College of Marine and Earth Studies. Includes bibliographical references.