This paper will focus on two elements of the expanded version of the assimilation model: acculturation and residential segregation. If, as Gordon has postulated, acculturation is a precursor to other forms of assimilation, there should be a statistically significant association between acculturation and segregation. Specifically, minority groups that measure high on acculturation should be less segregated from the dominant population than groups that score low on acculturation

Atmospheric particulate matter (PM) has important implications on air quality, global climate and human health. However, significant uncertainty remains in the chemical and physical transformations of PM during atmospheric transport. Ambient measurements are critical for understanding the sources and processing of the aerosols in order to inform models and public policy. In this work, high-resolution soot-particle aerosol mass spectrometry (SP-AMS) was used during three different field campaigns to obtain real-time measurements of aerosol composition and properties under a variety of different environments to better understand the atmospheric evolution of PM. The first study was conducted at the Mt. Bachelor Observatory (MBO), a mountaintop site in the Pacific Northwest, in order to explore the aging of biomass burning (BB) emissions and their effects on the remote troposphere. Despite low aerosol concentrations, oxidized biomass burning organic aerosol (BBOA) exhibiting extremely low volatility was detected throughout the study. Five wildfire plume events that had undergone between 10 hours and 10 days of atmospheric transport were sampled and a statistically significant loss of OA mass relative to CO was seen, indicating the removal of OA during long range transport. The results from this field study were also integrated with observations from the Biomass Burning Observation Project (BBOP) campaign, which characterized fresh wildfire emissions to provide a detailed depiction of the evolution of biomass burning organic aerosol over its atmospheric lifetime. The second study took place in Fresno, a highly polluted city in the San Joaquin Valley of California impacted by residential wood burning emissions. Here, the SP-AMS was operated in a configuration to selectively measure only black carbon (BC) containing soot particles. A persistent, multiday fog event was used as a case study to examine the aqueous-phase processing of the soot aerosol within fog droplets. Fog processing resulted in a substantial increase in BC coating thickness due to the accumulation of ammonium nitrate and secondary OA formed in the aqueous phase. Reactions occurring in cloud and fog droplets were found to play a key role on the amount and composition of coating material present on black carbon aerosol. Finally, a SP-AMS was operated during the Tracking Aerosol Convection Interactions Experiment (TRACER) in Houston, TX in order to explore the sources of soot particles and their effects on cloud properties. Both ensemble and single particle spectra were collected in order to directly characterize the black carbon mixing state. K-means clustering analysis of the single particle measurements revealed diverse and highly variable soot particle compositions with coating-to-mass ratios spanning between 0.1 and 100. The coating material was generally hygroscopic, including oxidized OA and sulfate, suggesting that these particles may act as effective CCN.

Enhancers are elements within our genome that control where and when genes are expressed throughout development. However, how the sequence of the enhancer regulates tissue-specific expression is not fully understood. We can investigate sequence by looking at the transcription factor binding motifs within enhancers. We want to better understand how combinations of motif syntax: the order, orientation, and spacing of motifs, interplays with motif affinity to regulate gene expression. We term the connections between syntax and affinity enhancer grammar. We use the neural plate Otx-a enhancer within Ciona intestinalis as a model to investigate if enhancer grammar is present, and to look for motif syntax and affinity trends giving different expression patterns. This enhancer activates when bound by GATA and ETS transcription factors. Our data shows that there is a grammar present within the Otx-a enhancer, as different grammatical variants give varying expression patterns. Our data suggests that changing the motif order to having ETS binding sites on both ends of the enhancer abolishes Otx gene expression in most developing embryos. Our data also shows a loss of expression caused by ETS motifs directly next to each other in combination with non-optimal spacing between high affinity GATA and ETS. We also found a grammatical variant with notochord expression, which may be due to two ETS sites close to a FoxA binding site. These findings help us better understand the grammar of the Otx-a enhancer and help us understand how enhancer sequence codes tissue-specific gene expression in development.