Comparative transcriptome profiling of human foreskin fibroblasts infected with the Sylvio and Y strains of Trypanosoma cruzi

Trypanosoma cruzi, the causative agent of Chagas Disease, is phylogenetically distributed into nearly identical genetic strains which show divergent clinical presentations including differences in rates of cardiomyopathy in humans, different vector species and transmission cycles, and differential congenital transmission in a mouse model. The population structure of these strains divides into two groups, which are geographically and clinically distinct. The aim of this study was to compare the transcriptome of two strains of T. cruzi, Sylvio vs. Y to identify differences in expression that could account for clinical and biochemical differences. We collected and sequenced RNA from T. cruzi-infected and control Human Foreskin Fibroblasts at three timepoints. Differential expression analysis identified gene expression profiles at different timepoints in Sylvio infections, and between Sylvio and Y infections in both parasite and host. The Sylvio strain parasite and the host response to Sylvio infection largely mirrored the host-pathogen interaction seen in our previous Y strain work. IL-8 was more highly expressed in Sylvio-infected HFFs than in Y-infected HFFs.

ESSAYS ON DISPLACED WORKERS AND RESIDENTIAL MIGRATION

In this dissertation, I explore how workers’ human capital, local industry composition, and business cycles affect employment outcomes and residential migration for job losers and other workers. I first examine whether the poor employment outcomes of job losers are due to a lack of jobs that require their human capital within their local labor market. I answer this question by analyzing the extent to which the industry composition in the job loser’s local labor market affects employment outcomes when job loss occurs during expansions and during recessions. I find that if job losers reside in an area with a high employment concentration of their original industry of employment, they are 2.1-2.8 percent more likely to be re-employed at another job if job loss occurs during an expansion; I find an insignificant relationship in most specifications when job loss occurs during a recession, and in some specifications I even find a negative relationship between industry concentration and employment. I conclude that the industry composition within an area matters for job losers, since firms are more willing to hire workers from within their own industry, as these workers have more relevant accumulated human capital. However, firms are less likely to hire during a recession, making job losers’ human capital less important for job finding. Next, Erika McEntarfer, Henry Hyatt, and I examine whether the business cycle affects earnings changes for job losers, and the factors that explain these differences across time. We find that job losers who lost their job during the Great Recession have earnings changes that are 10 percent more negative relative to other job losers from other periods. This result is driven primarily by longer nonemployment lengths and worse subsequent job matches. Finally, Erika McEntarfer, Henry Hyatt, Alexandria Zhang, and I explore the extent to which residential migration is driven by job opportunities. We use four databases and find that changes in job moves explain some of the changes in residential migration, but the relationship is not as strong as previously documented. We find that migration patterns differ across databases, with some databases documenting steeper declines and more cyclicality.