The marine otter (Lontra felina) inhabits patches of rocky coastline from central Peru to southern Chile and is classified as Endangered by the IUCN. Given the limited information available about the species, we set out to assess marine otter diet with a view to detecting latitudinal differences, and to assess marine otter activity budgets and interspecific interactions (including anthropogenic) at Peruvian fishing villages and to compare results with similar Chilean studies. Nine study sites from central Chile to southern Peru were sampled for otter spraints to assess relative frequency of prey types and two fishing ports in southern Peru were monitored through focal and scan observations to assess activity patterns, interspecific interactions, habitat use patterns, and dive durations. Results indicate that toward the northern part of its range, crustaceans become less important and fish more important in the diet. Interactions were observed between marine otters and other species, including stray dogs and cats. The strong dependence of marine otters on the availability of safe rocky shelters, and the species’ apparent tolerance to living alongside humans raise conservation concerns about vulnerability to anthropogenic threats. These factors, if not correctly managed, could turn some of these rocky seashore patches into population sinks.

The induction of macrophage death is regarded as a potential mechanism by which components secreted by Clostridium septicum are used to evade the innate immune response and cause tissue damage. This study aimed to determine the effect of partially purified fractions of extracellular proteins secreted by C. septicum on the death of mouse peritoneal macrophages. Elicited mouse peritoneal macrophages were incubated with partially purified fractions of proteins secreted by C. septicum into culture medium. After incubation, we found that the protein fraction with a molecular weight ≥ 100 kDa caused significant cell death in macrophages, changed cell morphology, increased markers of apoptosis and autophagy, and increased the expression (protein and mRNA) of IL-1 and TNFα. Our data suggest that the proteins secreted by C. septicum (MW ≥100kDa) induce cell death in macrophages by promoting autophagy-triggered apoptosis. This may contribute to our understanding of the molecular mechanism of immune evasion by C. septicum at the infection site.

Climate change is now affecting every known society. Small farmers in Low Income Countries (LICs) are especially vulnerable to climate change patterns because they depend heavily on rain, seasonality patterns, and known temperature ranges. To help build climate change resilient communities among rural farmers, the first step is to understand the impact of climate change on the population. This dissertation aims to use information and communication technology (ICT) to assess climate change vulnerabilities among rural farmers. To achieve this overall goal, this dissertation first proposes a comprehensive Climate Change Vulnerability Assessment Framework (CCVAF) that integrates both community level and individual household level indicators. The CCVAF was instantiated into a GIS-based web application named THRIVE for different decision makers to better assess how climate change is affecting rural farmers in Western Honduras. Qualitative evaluation of the THRIVE showed that it is an innovative and useful tool. The CCVAF and its instantiation provides an important initial step towards building climate change resilience among rural farmers. It is the first attempt to provide a comprehensive set of the indicators with related measurements and data sources for climate change vulnerability assessment. The framework thus contributes to the knowledge base of the climate change vulnerability assessment. It also contributes to the design science literature by providing guidelines to design a class of climate change vulnerability assessment solutions. To the best of our knowledge, the CCVAF is the first generalizable artifact that can be used to build a group of ICT-based climate change vulnerability assessment solutions. Another knowledge contribution of this dissertation is its reproducibility by making the input and output data available to the research and practitioner community through a GeoHub. For practical contributions, the framework can be easily used by researchers and practitioners to consistently design a vulnerability assessment tool, starting with the set of indicators organized by the three-level determinants, and following specific spatial data analysis and models. Such an ICT-based tool adds practical values to tackle climate change challenges.

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Decades of research demonstrates that minoritized groups are disproportionately affected by swathes of harmful pollutants, including air pollution, even controlling for low income. Would significantly reducing individual car traffic help reduce the EJ gap? The systemic shock of the COVID‐19 economic shutdown, with accompanied reduction in car use, can be exploited to analyze this question. Kerr and colleagues ask this question for nitrogen dioxide (NO2), use satellite data and categorical differences, and find that majority‐minoritized tracts on average benefited more from the shutdown, but the least‐White tracts still were significantly worse off than the most‐White tracts. We further explore this question for PM2.5, one of the most harmful air pollutants, using Geographic Information System (GIS) methods to combine several different federal datasets to compare pre‐ and post‐COVID‐19 shutdown. Analyzing Census tracts, we find (1) little evidence of discrimination in the placement of PM2.5 sensors, (2) evidence of the standard EJ disproportionality for PM2.5 in both pre‐shutdown 2019 and post‐shutdown 2020, but (3) evidence of disproportionate improvement for Asians, Hispanics, and Native Americans, with concerning indications of possible harm to African Americans. This implies, as do the findings in Kerr and colleagues' study, that policies that limit gasoline‐powered car use can reduce air pollution but are unlikely to importantly alleviate US environmental racism affecting African Americans.