Anthropogenic climate and land-use change are widely considered to be the two greatest threats to global biodiversity and ecosystem functioning. Although species may respond to changing environments in a variety of ways, the majority of species are expected to shift their distributions to track ecologically favorable habitats. The extent of these shifts may be heterogenous across species or even within a species occupying different regions, but our knowledge of what drives this heterogeneity is still sorely lacking. In particular, the effects of climate and land-use change on shifting species distributions have largely been studied independently. In more realistic scenarios, most species will experience both drivers simultaneously, creating the potential for heterogeneous changes in species composition across regions with different histories of climate and land-use change, as well as species with different sensitivities to that change.

To investigate the combined effects of climate and land-use change on species occupancy and community composition, I surveyed avian diversity at 71 sites in the California Central Valley and Los Angeles. These sites were originally surveyed in the early 1900s by Joseph Grinnell and colleagues from the Museum of Vertebrate Zoology, providing a unique opportunity to directly compare bird occupancy and its relation to site-specific climate and land-use covariates across a century of change. Historic surveys paired with modern resurveys documented changing distributions by 148 bird species across two regions with similar initial species and habitat composition but differing patterns of climate and land-use change.

Our knowledge of species’ ecological and life history traits as predictors of sensitivity to land-use change is well developed, but the same cannot be said for traits as predictors of climate-induced range shifts. There is strong theoretical support that range shifts under climate change may be mediated by traits that facilitate dispersal and population establishment, but empirical evidence for this relationship has been mixed. In my first chapter, I conducted a meta-analysis of studies that analyzed climate-induced range shifts as a function of species’ traits, with the goal of identifying which traits have provided the strongest results. I show that the majority of traits failed to predict range shifts consistently across studies, while a much smaller number of traits, particularly habitat breadth, had strong empirical support. In subsequent chapters, I use the most informative species’ traits revealed by this meta-analysis to explore differences in species-specific occupancy change across my Central Valley and Los Angeles survey sites.

Both climate and land-use change are expected to favor exotic and generalist species over specialists, resulting in declining occupancy and diversity. Using occurrence data for 122 bird species from 41 resurvey sites in the California Central Valley, my second chapter examined how occupancy and diversity changed over the past 100 years in this predominantly agricultural region, as well as the relative influence of climate versus land-use covariates to occupancy within each survey period. In contrast to expectations that occupancy and diversity would decline, both remained stable: species that increased in occupancy (predominantly habitat generalists or human adapters) roughly balanced species that decreased in occupancy (predominantly open-habitat species), resulting in no significant change in average species richness or between-site diversity. Equally surprising was the far greater importance of water availability (precipitation and water cover) to occupancy within each survey period as compared to urbanization or agricultural cover.

The relative importance of climate versus land-use change to changes in species occupancy is poorly known and may result in heterogeneous patterns of diversity change across regions with different climate and land-use change histories. In my third chapter, I used occurrence data for 148 bird species across the full set of 42 Central Valley sites and 29 Los Angeles sites. I directly assessed the relative importance of climate and land-use covariates to probabilities of occupancy, persistence, and colonization, as well as compared patterns of occupancy and diversity change between the two regions. Climate and land-use covariates were both important, but to different aspects of occupancy and turnover, with climate driving initial occupancy, climate and land-use both having similar influence on colonization, and urban cover emerging as the biggest driver of local persistence. In contrast to stability in occupancy and diversity in the Central Valley, both declined in Los Angeles. This diversity loss resulted from a greater amount of urban development in Los Angeles and larger species-specific occupancy decreases in particularly forest and open-habitat species.

Overall, my dissertation provides a detailed picture of how bird species have responded to over a century of climate and land-use change. These changes were highly heterogeneous across species – driven by traits, namely habitat preference – and across very similar ecological regions – driven by divergent patterns in both climate change and urbanization. As we continue to create range projections and plans to conserve future diversity, it will be important to utilize knowledge generated by long-term historical datasets and to incorporate multiple drivers of heterogeneity in species’ responses to global change.

The methodological challenges associated with conducting research on air pollution mixtures are well-known: correlated co-pollutants result in unstable effect estimates and large standard errors, hindering the assignment of causality to any one exposure. There is still relatively little research in the growing multi-pollutant literature that is focused on the mixture itself as the unit of analysis. In this dissertation, I implement a statistical method from the causal inference literature to estimate the effects of ambient air pollution, as single pollutants and in a two-pollutant mixture.

I analyze the effects of single-pollutant and multi-pollutant summertime ambient air pollution exposures on pulmonary function in a cohort of children with asthma living in Fresno, California. I employ a technique from the causal inference literature, the Population Intervention Model (PIM), to describe the health effects that would result from several hypothetical interventions that involve lowering concentrations of ambient air pollution. By describing the health effects of the ambient air pollutants in these terms, this approach estimates results that are relevant to real-world policy questions. Furthermore, this analytical approach permits the calculation of air pollution health effects that correspond to multiple pollutants dynamically changing within a mixture, as ambient air pollution is actually experienced by people. I interpret each of these health effects according to whether it reflects a realistic, or even a possible, exposure scenario during the study period and in the region where data were collected. I achieve this through an examination of the individual and joint distributions of the pollutants under study.

This dissertation contains several analyses, corresponding to single- and multi-pollutant exposure regimens. In the first analysis, I analyze the effects of ambient summertime NO2 on FEF25-75 in a single-pollutant approach that demonstrates the methodological approach. All analyses use central-site exposure data, assigning all subjects on a given study day the same air pollution exposure values. Ambient PM10-2.5 is analyzed throughout as a summertime pollutant of secondary interest, both in a single-pollutant PM10-2.5 analysis, and in a mixture analysis. For the multi-pollutant mixture analysis, I extend the Population Intervention Model framework demonstrated in the single-pollutant analyses to a two-pollutant summer analysis of ambient NO2 and PM10-2.5, estimating health effects associated with an intervention that dynamically alters levels of one or both pollutants. In this two-pollutant analysis, I estimate the effects of lowering levels of one co-pollutant while "controlling for" the other (i.e., holding it at observed levels), as well as the effects of a joint intervention that decreases levels of both pollutants.

The Background chapter presents a brief history of air pollution epidemiology and policy, and reviews the epidemiologic and statistical research upon which this dissertation builds. The Methods chapter describes the data collection protocol of the Fresno Asthmatic Children's Environment Study (FACES), the theoretical basis for the chosen methodological approach, and the details of the statistical methods employed in these analyses. In the Results section, I describe the characteristics of the FACES study sample, provide tabular and graphical descriptions of the distribution of ambient air pollution in the study, and present the results of the single- and multi-pollutant PIM analyses. In the Discussion section, I provide interpretation of the effects estimated in these various analyses, and refer back to the single- and multi-pollutant exposure distributions to situate the various health effects in appropriate context, and to speculate on potential sources of bias.

All health effects calculated in these analyses were estimated relatively imprecisely; however, comparison of the magnitude and direction of the risk differences across analyses demonstrates patterns and provides information about the respiratory effects of the pollutants analyzed in this study. Furthermore, consideration of the individual and joint distributions of the two exposures yields key insight that guides the interpretation of these findings, especially as relates to parameter identifiability. In this analysis, there is ample evidence that the types of air pollution profiles described by two interventions are not realistic given the observed data, and furthermore that there is not support in the data to estimate health effects for these interventions. These parameters were defined to be comparable to standard practice in the multi-pollutant literature. The finding that they were not identifiable in the FACES data argues against giving weight to these specific findings, and also raises broader questions about parameters of this type: large, isolated single-pollutant concentration changes in a multi-pollutant exposure regimen. The work presented here emphasizes that such parameters should be scrutinized for positivity and data support before commencing analysis, regardless of the analytical approach chosen.

Attempts to understand Tacitus’ treatment of Roman soldiers have tended to focus on his aristocratic bias towards the lower-class citizen soldiers. These studies used evidence from throughout Tacitus’ corpus which show the historian describing the unruly, ruthless, and often violent actions of soldiers. As an aristocrat, Tacitus was describing the actions of a group of people whom he apparently despised. These studies on Tacitus’ treatment of soldiers, therefore, neglected the potential for discussing the military values of common soldiers. The assumption that Tacitus was a biased aristocrat who looked down on the figure of the soldier fails to consider the scenes throughout the historian’s corpus that speak toward the military values of soldiers. Military values can tell us a great deal about the soldiers who embody them. They also, as is the case with Tacitus, inform us about the relationship between soldiers, their values, and the military commanders who lead them. Military values of common soldiers were part of a larger system of military, and therefore political, infrastructure that had lasting impacts on Roman life under the Principate, and this dissertation attempts to provide a nuanced understanding of how Tacitus wrote about those military values and why it was important for him to do so. This dissertation also approaches the issue from the material evidence left behind during the Principate. The funerary epitaphs and imperial monuments from the 1st-2nd centuries AD provide an alternative perspective on the importance of the military values of common soldiers both for the soldiers themselves and the aristocracy who lead them. The Tacitean evidence combined with the material evidence considered in this dissertation point readers of Tacitus in a different direction than the predominant trend in scholarship on Tacitus’ treatment of common soldiers. Tacitus crafted his narratives about common soldiers to include their military values, because he recognized the importance of understanding these military values for whoever was leading the soldiers. Under the Principate, this was ultimately the princeps himself, but included the aristocratic generals serving the princeps in the provinces. The military values of legionary soldiers, then, play a role in how Tacitus writes the history of military leadership, both its successes and its failures.

Forum Theatre (FT) was created by Brazilian theatre director Augusto Boal (1985) as an approach for promoting dialogue between the audience and those performing on stage for his “Theater for the Oppressed.” FT offers an accessible, interactive approach to exploring challenging topics and situations.  In FT, a short scene is performed.  It is then replayed again and again with audience members invited to intervene and offer different options for addressing various aspects of the problematic situation.  Originally directed to helping people address and transform oppressive conditions that characterized their lives, FT has evolved and found expression in many different communities and contexts, including health professional education.  Inspired by David Diamond’s (2008) “Theatre for Living” model (which approaches living communities as a complex, living entities), we introduced FT in the “Introduction to Medicine & Dentistry” (DMED 511) course offered as part of the Undergraduate Medical Education program in the Faculty of Medicine & Dentistry (FoMD).  In this article, we describe how we have successfully engaged first year medical and dental students in discussion and critical reflection of professionalism issues relevant to their experiences of small group learning using FT.

This study addresses the relationship between intergenerational trauma of ongoing United States and Canadian colonialism as it impacts Native American and Aboriginal First Nations Peoples and ways global football contributes practices of intergenerational healing. I argue that Indigenous soccer operates as a mechanism of decolonization and re-membering for Indigenous Peoples who inherit colonial traumas. Indigenous soccer directly challenges hegemonic sports culture as typically marked by Indian mascotry and Native invisibility. While cultural historians have shown how American sports are used as colonial technologies of assimilation, violent gendering, labor and militarism, the story of Indigenous soccer has not been studied. As a Lummi footballer, I utilize Native voices from Coast Salish Tribes of Washington State and British Columbia, Mohawk and Cree First Nations Canada, Southwest tribes from New Mexico Pueblos and Navajo Nation, and Kiowa Territories in Oklahoma to illustrate Indigenous soccer identities and schelangen, or way of life in Lummi. As soccer in North America challenges hegemonic ideologies of nationalism, instrumental Indigenous footballers are demanding visibility, like the late Canadian Hall of Fame First Nations Aboriginal footballer Snuneymuxw Harry Xulsimalt Manson and U.S. World Cup participant Kiowa Native Chris Bau Daigh Wondolowski. Using the theoretical framework of Tulalip scholar Stephanie Fryberg's “theory of invisibility,” I tell and analyze Indigenous soccer stories as evidence that Indigenous visibility, in soccer or otherwise, provides intergenerational healing. I begin to fill the gap in the sports culture and U.S.-Canada colonialism discourse, with the goal of making Indigenous soccer locally accessible as an instrument of decolonial healing for generations of Indigenous North American Peoples.