Understanding complex and dynamic inter-specific relationships is key for informing and developing conservation policies. Accurately identifying the diet of various predators across Washington can provide insight into these relationships in terms of resource needs and predator-prey dynamics. DNA metabarcoding studies present a comprehensive way to surmise the complete diet profile of the American black bear (Ursus americanus), an opportunistically omnivorous predator that provides several important ecosystem services. As one of the only large omnivores in Washington, they also require large home ranges, making them an umbrella species that can be used as a guideline for overall conservation efforts. Our preliminary metabarcoding study with scat comparing the American black bear’s diet in northeastern and central Washington using a mitochondria-specific marker suggested their diet could be greatly influenced by human activity and that diet preference could delineate along geographic and ecological means. As the samples containing atypical food sources were within proximity to anthropogenic structures, these results suggest the pervasiveness of human-based food source availability to wildlife. These results were corroborated in our comprehensive study using both mitochondria and chloroplast specific markers. Analysis of the herbivorous portion identified the native and introduced plant species and their frequency of occurrence. This allowed us to understand the American black bear’s reliance on specific native species, as well as the extent of how local bear populations have incorporated non-native plant species into their diet, thus identifying their ecosystem intrusion. Additionally, the study’s sample collection spans a multiyear period, providing information on the seasonality of the American black bear’s diet, giving insight into seasonal prey switching and prey partitioning. This total diet profile allows for the examination of the influence of the wildlife-urban interface on food availability and resource selection in the Washington American black bear population, increasing our understanding of Washington predator dynamics.

After an 80-year absence, gray wolves have been returning to Washington state over the last decade. Mapping their population growth and reproductive activity is key to understanding their recovery and to assisting wildlife conservation management. Recognizing an established pack requires identification of the presence of breeding females. Accurate noninvasive identification of pregnant wolves through scat could greatly assist such efforts. A reliable index of pregnancy in most mammals is progesterone levels (ng/g) in feces; progesterone rises post-ovulation, but will only be elevated above a “pregnancy-threshold” level among pregnant females. However, this metric is less definitive in canids. Progesterone levels remain elevated in all post-ovulatory females, regardless of whether the females become pregnant or not. Since gut microbiome diversity has also been shown to differ between pregnant and non-pregnant large mammals, in this study I examined whether the combination of progesterone levels and gut microbiome diversity can refine this pregnancy metric in free-ranging wolves. Fecal samples from female wolves (n=62) with known progesterone levels were provided by the Center for Conservation Biology from a 2015-2017 study in Northeast Washington. Samples with progesterone levels above 2000 ng/g were defined to be from potentially pregnant females. I generated gut microbiome profiles by amplifying and sequencing the V4 16S rRNA gene region in each sample. I analyzed the sequences using Qiime 2 and R with the Silva reference database for microbial taxonomy classification. Gut microbiome profiles were compared to progesterone levels. Pregnant wolves are expected to have a different phyla diversity in bacterial communities from non-pregnant wolves. Results may guide future studies to focus on identifying a particular bacteria species or a certain proportion of diversity combined with progesterone levels to further refine pregnancy diagnosis. Accurate identification of pregnancies in wolf packs can improve population growth estimates, leading to informed Washington wildlife conservation policies.

Nanofibers have broad capabilities in biomedicine, e.g. drug delivery and tissue engineering, because of their diverse tunable properties. For these purposes, nanofibers often must be patterned to be integrated in devices or to optimize their function. Current nanofiber patterning methods lack user-control over design or alter fiber integrity. To optimize and expand the applications of nanofibers, there is a need for a versatile nanofiber patterning strategy that maintains material integrity and function and can be generalized for patterns of different complexity and dimensions. This project aims to address this need with an in situ patterning strategy that allows for complex, three-dimensional patterning at the milli/microscale with different fiber materials. The approach consists of a two-layer composite electrospinning collector with an insulative layer and conductive recessed patterns. An inexpensive collector fabrication method was designed for rapid prototyping. Collector design features predicted to affect fiber deposition were evaluated by quantifying fiber selectivity. Optimal formulations of nanofiber materials were experimentally evaluated based on reproducibility, fiber yield, and selectivity to delineate key polymer solution properties affecting patterning. This project offers a guiding foundation to adapt this patterning strategy to various applications of nanofibers by tuning fiber formulations and specific collector design features.

With growing concerns surrounding global warming, both pollution and alternative sources of energy have become the focus of intense research. These research efforts have addressed the need to power pollution sensors by alternative means. Harvesting energy from trees is both minimally invasive to the environment and eliminates harmful waste produced by non-green energy solutions like batteries. The intent of this research is to verify the possibility of developing an unconventional thermoelectric generator (TEG) in order to increase the energy obtained from trees. We believe that a comprehensive understanding of the temperature characteristics of trees improves the current thermoelectric harvester design. A more robust TEG produces the voltages necessary to power these IoT devices. The primary concerns in selecting materials for a specialized TEG are the thermal impedance, the dimensions and arrangement of semiconducting material, and the overall geometric composition of the TEG itself. The selection of these materials and the overall physical characteristics of the TEG depend on the analysis of the internal temperature of trees. We have developed and will soon deploy a system that captures this valuable data over time. Furthermore, we have established a theoretical TEG design tailored specifically to harvest energy from trees more effectively than previous implementations. The new harvester will be utilized to power LoRa wireless sensor networks capable of monitoring pollution and other environmental hazards. If successful, future research should be devoted to optimizing the TEG to minimize thermal resistances and parasitic heat losses, as well as efforts to maximize temperature differentials with the use of smart heat exchangers on the TEG’s ambient side. Electrical matching of the TEG and sensor node could be desirable too. Finally, integration of the TEG into other sensor applications such as wildfire monitoring is more than reasonable.

The Seattle COVID-19 Oral History Project (SCOHP), sponsored by the Harry Bridges Center for Labor Studies, was started in the spring of 2020 as an initiative to document the experiences and stories of workers and unemployed individuals in Western Washington during the COVID-19 pandemic. Focusing especially on communities of color, the project aims to create an oral history archive for students, researchers, and the general public housed in the Labor Archives of Washington (LAW). Although educational institutions such as Columbia University have started oral history projects to document the effect of COVID-19 on their local communities, many of these are not geared specifically toward frontline workers, whose daily lives have collectively been changed the most by the pandemic. I have developed the idea and structure for SCOHP as a project utilizing oral history to obtain an in-depth, on-the-ground perspective for studying workers and marginalized communities specifically. I collaborate with the local chapter of the Asian and Pacific American Labor Alliance (APALA Seattle), UNITE HERE Local 8, and Service Employees International Union (SEIU) 1199NW to set intentions for the project, co-develop interview questions, and recruit interviewees. Collaborating with LAW, I have helped create and implement oral history trainings for a team of 12 student interns who will assist in preparation, interviewing, and processing. Our goal is to collect and process at least 20 interviews over the course of Winter and Spring of 2021, focusing on the topics of worker health and safety, race and intersectionality, childcare, the Black Lives Matter movement, labor unions, and differences across industries. This work is important for both documenting the experiences of occupational and other communities who have often been underrepresented in media coverage and popular discourse on COVID-19, and highlighting the intersections between occupation, race, ethnicity, immigration, and public health in a global pandemic.

Cellulose is an abundant biopolymer that provides much of the structural support for plant cell walls. Its many desirable properties include high tensile strength, biocompatibility, thermal stability, and high water absorption. Cellulose has considerable potential as a component in polymeric composite materials, which combine polymer matrices with fillers to enhanced their mechanical properties for applications in drug delivery, food engineering, packaging, medical implants, and textiles. Even so, the difficulties of processing and manipulating cellulose at industrial scale have been cost prohibitive due to its high energy, chemical, and water usage. Here, we investigate the potential for simultaneous in situ production and incorporation of cellulose within hydrogels based on a photo-curable derivative of Pluronic® F-127, F127-bisurethane methacrylate (F127-BUM). We utilized a “symbiotic culture of bacteria and yeast” (SCOBY), obtained from a commercially available fermented tea beverage (Kombucha) starter kit, for the hydrogel formulation. We show that within cured F127-BUM hydrogel constructs, a SCOBY is viable and its biomass increases over time when maintained with a sucrose and black tea medium. These results will lead to further investigation into the composition of the SCOBY biomass, as well as physical and mechanical properties of the resulting composite material.