Transcriptomics of the human airway epithelium reflect the physiologic response to inhaled environmental pollutants

Current methods for the risk assessment of environmental exposures commonly involve questionnaires, stationary monitoring, and personal air sampling. However, as these approaches do not capture the body's internal response, they lend minimal understanding to the biologic consequence of exposure. In order to address the unmet need of connecting external exposure measurements with signatures of internal exposure, this thesis examines the overarching hypothesis that transcriptomic changes in the human airway epithelium can serve as indicators of physiologic responses to inhaled pollutants. This is an extension of previous work that has demonstrated an airway ''field of injury'' effect where cigarette smoke exposure alters gene-expression in epithelial cells lining the respiratory tract. Specifically, I examine transcriptomic changes and the biologic responses associated with exposure to the following pollutants: environmental tobacco smoke (Aim 1), household air pollution from smoky coal combustion (Aim 2), and electronic cigarette vapor (Aim 3). First, I performed whole-genome transcriptional profiling of the nasal epithelium in children and adults and detected gene-expression changes associated with exposure to environmental tobacco smoke. Next, I employed similar approaches to detect a signature of coal smoke exposure in the buccal epithelium of healthy, non-smoking females exposed to household air pollution Xuanwei, China. The findings from these studies suggest that upper airway gene-expression can reflect the host response to prolific sources of environmental exposures that are major risk factors for chronic lung disease. Lastly, I examine the cellular and physiologic consequences of electronic cigarette (ECIG) aerosol exposure by analyzing transcriptomic profiles of human bronchial epithelial cells that have either been (1) differentiated and exposed in vitro or (2) acquired via bronchoscopy from the airway epithelium of ECIG users. The studies detailed in this dissertation offer valuable insight that will accelerate the efforts to evaluate the health effects of both well-established and emerging types of inhaled exposures in large-scale population studies. Furthermore, the transcriptomic strategies woven throughout the following chapters push for a novel assessment paradigm that may enable the public health community to rapidly characterize the physiologic host response to inhalation exposures of different sources, and to evaluate the biologic consequences of exposure-reduction initiatives.2017-05-01T00:00:00

Proceedings of 2011 Kentucky Water Resources Annual Symposium

This conference was planned and conducted as part of the state water resources research annual program with the support and collaboration of the Department of the Interior, U.S. Geological Survey and the University of Kentucky Research Foundation, under Grant Agreement Number 06HQGR0087. The views and conclusions contained in this document and presented at the symposium are those of the abstract authors and presenters and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government or other symposium organizers and sponsors

Spatiotemporal Variability in the Macroinvertebrate Community of a Small Coastal California Stream, Little Creek, Davenport, California

Macroinvertebrate community structure was characterized along the channel gradient of a headwater stream in a coast redwood forest on Cal Poly’s Swanton Pacific Ranch in Davenport, California. The significance of physical habitat characteristics in describing macroinvertebrate assemblage structure was assessed in an effort to create a framework to better understand the expected biological response to riparian canopy manipulation. Seven study reaches were established in 2015. These study reaches were evenly spaced throughout the Little Creek watershed, an approximately 4.8 km2 drainage characterized by steep inner-gorge areas and dense riparian vegetation. Macroinvertebrate samples were collected seasonally (i.e., spring, summer, and fall) during 2015 and 2016 using the Reachwide Benthos procedure described by the Surface Water Ambient Monitoring Program’s bioassessment protocol and all captured organisms were identified at family level taxonomic resolution. Non-metric multidimensional scaling (NMDS) and Analysis of Variance (ANOVA) procedures were performed to describe longitudinal patterns in community composition and determine the significance of collected environmental variables as predictors of community structure. The majority of taxa collected belonged to the orders Ephemeroptera, Plecoptera, Trichoptera, and Diptera. Macroinvertebrate density and biomass were significantly associated with study reach, with relatively depauperate macroinvertebrate assemblages occurring in the upper study reaches and significantly larger, more diverse assemblages in the lower study reaches. Significantly higher density and biomass was observed during the summer sample period across all sites. A clear site level separation was observed at the South Fork study reaches where significantly higher abundances of Diptera taxa colonized the primarily bedrock channel at those sites. The most diverse and pollution-intolerant assemblages were observed in riffle habitat types. Stream shading and solar radiation were not significantly associated with any macroinvertebrate community metric examined, making it difficult to predict instream response to a riparian canopy manipulation. However, trophic interactions that influence secondary production in the study reaches could be inferred based on temporal patterns in feeding guild composition; the relative abundance of shredder taxa coincided with seasonal detrital inputs indicating that food webs largely depended on allochthonous energy sources. Therefore, there is significant opportunity for further investigation of energy production and utilization in the study reaches to guide riparian canopy management practices toward enhancing key trophic interactions. This study provides an extensive and novel biological baseline for macroinvertebrate communities in Little Creek

Rethinking Channel Protection Efforts: An Integration of Fluvial Geomorphology, Engineering, and Economics

In-stream channel degradation as a result of alterations to flow and/or sediment caused by urbanization can have detrimental ecological and socio-economic impacts. Although steps have been taken to minimize these impacts through stormwater regulatory efforts, there has been variance in effectiveness. As efforts have evolved to meet regulatory requirements and improve effectiveness, an awareness of the need for integrated watershed planning has developed. However, understanding of the linkage between in-channel sediment contributions, hydrogeomorphic setting, level of anthropogenic disturbance, and time dependent response remains limited. The rate channel forming work is performed, as result of increased surface runoff, is complex; therefore, incremental increases in flow do not necessarily lead to incremental changes in channel morphology. Rather specific geomorphic attributes and their spatial organizations dictate imbalances in hydraulic and mechanical disturbing/resisting forces over temporal patterns of flow.In an attempt to address inefficiencies, a framework is proposed integrating stormwater related mitigation efforts (“channel protection”), related engineering practices, fluvial geomorphology, and economics in order to evaluate the outcomes of mitigating efforts and associated cost-effectiveness. This framework is supported by hydrological modeling and field surveys used to explore surrogate measures of eroding and resisting force with the intent to capture potential imbalances and define attributes that determine stability within the Ridge and Valley Province of Tennessee. In combination with these efforts, detailed in-situ flow monitoring was completed at three small stream systems to calibrate and validate coupled continuous simulation models of hillslope and in-channel processes. Models are utilized to explore response trajectory and efficacy of various mitigating suites.This research contributes to a growing body of literature that suggests channel protection efforts and TMDL implementation plans (for purposes of sediment loading reduction) should incorporate stream system specific prevalent erosive processes, the mechanisms of those processes, and the geomorphic attributes that influence them to improve efficacy of efforts