The current study uses a combination of quantitative and spatial analysis to examine the impact of affordable housing administered by the Texas Department of Housing Affairs on the neighborhood crime rate, in Dallas, Texas. Pre and post construction period analysis, for duration of five years from 2000 to 2004 provided an in-depth view on the direct impact of affordable housing at the neighborhood level. The crime rates were measured alongside with the sociodemographic characteristics of the area to see any association between the two. The findings suggest that the affordable housing were mostly located in areas with higher concentration of minority population and low median household income. The results of this study showed negligible increase in crime rates but a through analysis could provide an in-depth analysis of the issue. / text

published_or_final_version / Economics and Finance / Doctoral / Doctor of Philosophy

In my dissertation I have broadly studied the evolution of RNA as well as the phylogenetic history of the actin protein family. In the first chapter I examined how various evolutionary processes interact at high mutation rates, which led to simple prediction based on the strength of selection. In the second chapter, I tested mRNA secondary structure stability at the beginning of genes as a way of identifying whether putative genes might be functional or not. Finally, I reconstructed the phylogenetic history of the actin protein family in vertebrates, revealing that a novel isoform is actively evolving in contrast to the remaining protein isoforms.

Each state or region within the United States has certain unique and distinct characteristics that cause its economic performance to vary from that of the nation as a whole. Unemployment rates, as summary measures of unutilized manpower resources, frequently serve as a gauge of the general economic situation and social well-being. It is a well documented fact that unemployment is not evenly distributed througout the nation. For example, although 54% of the labor force is concetrated in the northeast and north central regions, they only account for 46% of the unemployment in recent years. This thesis focuses on the measurement and behavior of unemployed in Indiana, with particular attention devoted to contrasting performance by the State's economy with that of the nation as a whole.

At hydrothermal vents, thermal and chemical gradients generated by the mixing of hydrothermal fluids with seawater provide diverse niches for prokaryotic communities. To date, our knowledge of environmental factors that shape bacterial and archaeal community composition and metabolic activities across these gradients within the active sulfide structures is limited. While many studies have laid the foundation for our understanding of the extent of diversity in relation to varying hydrothermal settings, few studies exists regarding the detailed spatial relationships between vent geochemistry and the abundance, distribution, and metabolic characteristics of the endolithic hosted communities. Even fewer data have been generated on the magnitude of metabolic rates and factors controlling the kinetics of these reactions have not been well constrained.

Not available / text

The three largest earthquakes in the last 25 years in southern California occurred on faults located adjacent to the southern San Andreas fault, with the M7.3 1992 Landers and M7.1 1999 Hector Mine earthquakes occurring in the eastern California shear zone (ECSZ) in the Mojave Desert, and the M7.2 2010 El Mayor-Cucapah earthquake occurring along the Laguna Salada fault in northern Baja California, Mexico. The locations of these events near to but not along the southern San Andreas fault (SSAF) is unusual in that the last major event on the SSAF occurred more than 300 years ago, with an estimated recurrence interval of 215± 25 years. The focus of this dissertation is to address the present-day deformation field along the North America-Pacific plate boundary in southern California and northern Baja California, through the analysis of GPS data, and elastic block and viscoelastic earthquake models to determine fault slip rates and rheological properties of the lithosphere in the plate boundary zone. We accomplish this in three separate studies. The first study looks at how strain is partitioned northwards along-strike from the southern San Andreas fault near the Salton Sea. We find that estimates for slip-rates on the southern San Andreas decrease from ~23 mm/yr in the south to ~8 mm/yr as the fault passes through San Gorgonio Pass to the northwest, while ~13-18 mm/yr of slip is partitioned onto NW-SE trending faults of the ECSZ where the Landers and Hector Mine earthquakes occurred. This speaks directly to San Andreas earthquake hazards, as a reduction in the slip rate would require greater time between events to build up enough slip deficit in order to generate a large magnitude earthquake. The second study focuses on inferring the rheological structure beneath the Salton Trough region. This is accomplished through analysis of postseismic deformation observed using a set of the GPS data collected before and after the 2010 El Mayor-Cucapah earthquake. By determining the slip-rates on each of the major crustal faults prior to the earthquake, we are able to model the pre-earthquake velocity field for comparison with velocities measured using sites constructed post-earthquake. We then determine how individual site velocities have changed in the 3 years following the earthquake, with implications for the rate at which the lower crust and upper mantle viscously relax through time. We find that the viscosity of the lower crust is at least an order of magnitude higher than that of the uppermost mantle, and hypothesize that this is due to mafic material emplaced at the base of the crust as the spreading center developed beneath the Salton Trough since about 6 Ma. The final study investigates crustal deformation and fault slip rates for faults in the northern Mojave and southern Walker Lane regions of the ECSZ. Previous geodetic studies estimated slip-rates roughly double those inferred via geological dating methods in this region for NW striking strike-slip faults, but significantly smaller than geologic estimates for the Garlock fault. Through construction of a detailed elastic block model, which selects only active fault structures, and applying a new, dense GPS velocity field in this region, we are able to estimate slip-rates for the strike-slip faults in the ECSZ that are much closer to those reported from geology.

The magnitude of global sediment flux from streams to the oceans over the last 5 Ma is poorly quantified, yet important for predicting future fluxes and deciphering the relative control of tectonic uplift, climate change, vegetation, and related feedback mechanisms on landscape evolution. Despite numerous proxy studies on global sediment delivery to the oceans, it remains uncertain whether bulk sedimentation increased, decreased, or remained approximately constant across one of the most significant global climate changes: the Plio-Pleistocene transition. New developments and strategies in the application of cosmic-ray-produced isotopes, in part developed by this thesis, provide records of pre-historic denudation of confined fluvial catchments in Texas and Yukon. Non-glaciated, tectonically passive regions were targeted in contrast to other studies on modern sedimentation rates in order to isolate the climate influence from glacial and tectonic controls. The results suggest that average catchment temperature, and surficial processes and other factors such as vegetation cover associated with temperature, are the primary controls on the variation in landscape denudation in regions lacking tectonics and direct glacial cover. Specifically, warmer temperatures yield higher denudation rates, both at the scale of glacial-interglacial climate change and over the Plio-Pleistocene transition. The implication is that stream sediment flux to the ocean from tropical and temperate regions was higher during the Pliocene than in the Quaternary. However, this may have been balanced by an increase in sediment flux from regions covered by warm-based glaciers during glacial periods, or by increased temporary continental storage during interglacial periods.

This thesis brings to the forefront of the existing literature the importance of analyzing transitional dynamics among different levels of schooling and to the labor market. I perform empirical analyses using confidential longitudinal survey data from Statistics Canada; employing program evaluation techniques, and regression modelling. The first chapter is joint work with Louis Christofides, Michael Hoy and Thanasis Stengos. We explore the forces that shape the development of aspirations and the achievement of grades during high school and the role that these aspirations, grades, and other variables play in educational outcomes such as going to university and graduating. We find that parental expectations and peer effects have a significant impact on educational outcomes through grades, aspirations, and their interconnectedness. Apart from this indirect path, parents and peers also influence educational outcomes directly. Policy measures that operate on parental influences may modify educational outcomes in desired directions. The second chapter estimates the wage returns to university quality. I distinguish between two distinct measures of university quality. The first is a survey-based university reputation ranking, and the second is a new ranking, which I construct from several university characteristics in order to objectively reflect the university quality. The findings indicate that the wage returns of having a Bachelor’s degree from a highly ranked university are 10.3% for women, and 13.4% for men. The returns are higher when comparing the wages in the top and bottom tails of the ranking distribution and gender differences are identified. The third chapter is a large-scale study on how students form and revise expectations. This affects their decision to drop out and/or change field of study once they have accessed post-secondary education. I find evidence that students change expectations and educational pathways as they are exposed to unexpected new information. This informs them about the quality of match between their own ability and the program that they are enrolled. Using non-parametric methods I show that this relationship is not linear.

Ontario cage culture operations produce the majority of farmed rainbow trout in Canada, using a diverse range of management practices that are expected to result in substantial variation in trout performance across the industry. A preliminary survey of performance data was undertaken, resulting in data from 5 commercial sites between 2008 and 2012. Commercial performance was somewhat poorer than expected, particularly for mortality rates, thermal-unit growth coefficients, and economic feed conversion ratios (average weighted values of 12%, 0.165, and 1.36, respectively). Substantial variability in all performance parameters within and across operations suggests that continued production monitoring and benchmarking could be highly valuable for improving the economic sustainability of the sector. For future benchmarking efforts to be effective, improvement and standardization of data collection methods is needed. As such, a number of recommendations are provided to the industry for the refinement and standardization of performance recording protocols used by Ontario producers.