Indiana University-Purdue University Indianapolis (IUPUI) / This paper compares two new methods for estimating daytime population against two existing models within downtown Indianapolis in Marion County, Indiana. The two existing models consist of the 2009 USA Daytime Population model created by ESRI and the LandScan Global Population Project developed by the Oak Ridge National Laboratory. A parking study of downtown Indianapolis, as prepared by the City of Indianapolis, Division of Metropolitan Development, is the basis of the first new method of estimating daytime population. The second method is a direct count of the daytime population using a methodology previously developed. Additionally, these four population estimates will be compared when applied to a scenario involving a hypothetical toxic gas plume.

Call number: LD2668 .T4 1953 O8 / Master of Science

We address the problem of the consistency between discrete and continuous models for density-dependent size-structured populations. Some earlier works have discussed the consistency of density independent age and size-structured models. Although the issue of consistency between these models has raised interest in recent years, it has not been discussed in depth, perhaps because of the non-linear nature of the equations involved. We construct a numerical scheme of the continuous model and show that the transition matrix of this scheme has the form of the standard discrete model. The construction is based on the theory of Upwind Numerical Schemes for non-Linear Hyperbolic Conservation Laws with one important difference, that we do have a non-linear source at the boundary; interestingly, this case has not been explored in depth from the purely mathematical point of view. We prove the consistency, non-linear stability and hence convergence of the numerical scheme which guarantee that both models yield results that are completely consistent with each other. Several examples are worked out: a simple linear age-structured problem, a density-independent size-structured problem and a non-linear size-structured problem. These examples confirm the convergence just proven theoretically. An ample revision of relevant biological and computational literature is also presented and used to establish realistic restrictions on the objects under consideration and to prepare significant examples to illustrate our points.

Dispersal is a fundamental ecological and evolutionary process that can create demographic and genetic linkage between neighbouring and distant locations, influencing the dynamics, structure and ultimately the persistence of populations. To understand observed population dynamics and structure and to predict future change, accurate and comprehensive data are required describing the pattern and magnitude of dispersal and gene flow across all relevant spatial scales. However, this is a major empirical challenge. In this thesis, I aimed to obtain comprehensive empirical data quantifying natal dispersal patterns and population genetic structure across multiple spatial scales using the European shag (Phalacrocorax aristotelis) as a model species. I used a combination of field observations of shags individually ringed on the Isle of May, Scotland and molecular genetic techniques to accomplish these aims. By locating adult shags that had been ringed as chicks on the Isle of May at their breeding locations across eastern Scotland, I demonstrated divergent dispersal distributions at small versus large spatial scales. Using both mitochondrial DNA markers and a newly developed set of microsatellite markers, I quantified population genetic structure across a pan-European scale. This was weak across both molecular markers suggesting a role for occasional effective long-distance dispersal. However, a suite of evolutionary forces besides gene flow can create observed population genetic structure. Therefore, I quantified population genetic structure across populations in eastern Scotland, and quantitatively linked this indirect estimate of gene flow with my direct field observations of dispersal. Dispersal parameters derived explicitly from field observations and the spatial organisation of populations were shown to strongly influence observed population genetic structure. Overall, these data demonstrate the need to utilise both field observations and genetic methods to comprehensively estimate the extent and effectiveness of dispersal and highlight the importance of accurately quantifying long-distance dispersal in particular for predicting future change.

No description available.

Thesis (MPA) --University of Limpopo, 2011 / The study investigates the challenges facing Statistics South Africa in conducting population census project in the Limpopo Province. A special focus is on the Capricorn District Municipality. Literature has been reviewed as secondary sources and primary information was collected from a sample of 70 respondents. The study used both qualitative and quantitative approaches in both data collection and analysis. The results from the study indicate that the major challenges facing Statistics South Africa in conducting population census projects include; lack of proper planning, insufficient budget, under count, over count, refusals, and lack of monitoring strategies. Based on the results, strategic recommendations were made.

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 205-209). Also available for download via the World Wide Web; free to University of Oregon users.

No description available.

Natural hybrid zones provide opportunities to study a range of evolutionary phenomena from speciation to the genetic basis of fitness-related traits. Additionally, investing the structure of hybrid zones can provide valuable insight in the ecology and evolution of species. The present dissertation approaches the investigation of natural hybrid zones between Xiphophorus birchmanni and X. malinche from a population genetics perspective. The goal of the chapters herein are to investigate the genetic structure of these natural hybrid zones overall and the genetic structure of the populations within them in an effort to better understand the factors producing and maintaining spatial genetic patterns among this species pair and their hybrids. Using informative single nucleotide polymorphisms (SNPs) in one mitochondrial and three nuclear intron loci, I show that hybrid zones occur in replicated fashion in multiple stream reaches along a gradient from high to low elevation. Tests of FIS and linkage disequilibrium (LD) revealed significant genetic structure within a small subset of populations. Specifically, parentals and hybrids all three occur in some locations while other locations appear to be hybrid swarms. I then investigated a behavioral mechanism of reproductive isolation - social association, which might affect population structure. In clean water, individuals shoaled significantly more closely with conspecifics. Additionally, genotyping of females and their embryos revealed signatures of non-random mating in structured populations. Taken together, assortative social grouping, which may translate to assortative female mate choice, likely plays a role in maintaining population structure. Finally, I show that fluctuating asymmetry is significantly higher in unstructured than structure populations. This is a further indication that some form of non-random mating occurs in structured populations and has effects on male phenotypes.

Thesis. / eContent provider-neutral record in process. Description based on print version record.