Chondricthyes such as sharks, skates, rays, and chimeras share the slow maturation and low fecundity traits, thus making them susceptible to overexploitation. To ensure the survival of these vulnerable species it is necessary to protect the habitat important to their recruitment. The purpose of the present study was to determine the sediment preference of juvenile Beringraja binoculata to gain evidence as to where their nursery grounds may be located in the Salish Sea. To do this we conducted one-hour filming trials of three four-month old skates in a tank sectioned off into four different sediment size classes. Skate 1 died one-third of the way through the trials so was removed from statistical analysis. However, we found that Skate 2 and 3 preferred to bury and rest in the smallest sediment size of 0.125-0.3 mm grain size with p-values of 0.00126 and 0.0814 respectively. This is consistent with literature on different species of skates around the world. Ongoing research would be valuable to determining the reason behind this preference and to use the information to locate the Salish Sea nurseries.

Microplastics (plastic < 5mm) has become a prominent research topic over the last 15 years. Microplastic research papers are published around the world, using a variety of organisms, environments, and interactions as study systems. Findings from these papers suggest that microplastics have negative effects, like behavior disruption and cell death, on marine organisms. This research project uses scientometrics to analyze if trends in regional plastic policies are correlated with marine microplastic research papers. Utilizing spatial analysis, we compared the rate and spread of microplastic research and plastic policies across the globe to identify a statistical relationship between them. We then further explored this relationship by determining if the distribution of study systems in a region’s research affected the quantities of policies in that region. We used the Web of Sciences database to obtain data on microplastics papers from 2006 to 2018. Our data has revealed that specific species are being used in research more than others and that there are large concentrations of microplastics papers in areas like Europe and China. Countries with large amounts of plastic research also have the most plastic policies. The results of this project help decipher how marine microplastics research can have an impact on plastic policy.

Microplastic (plastic < 5mm) pollution is increasing at an exponential rate in marine environments, leading to increased contamination of marine organisms. Previously, it was thought that the majority of microplastics were found in surface waters due to their positive buoyancy; however, recent studies show pollution exists throughout the water column. Mussels, suspension feeding bivalves, can be catalysts to the spread of microplastic pollution to different trophic levels through filtration, ingestion, and egestion of microplastics. Mussels are prominent benthic-pelagic coupling organisms in marine ecosystems, moving particles and nutrients between habitats through different types of biodeposits. Mussels produce feces and pseudofeces, where feces is the digested biodeposit and the pseudofeces are the rejected materials. Accumulation of microplastics in their biodeposits may interfere with this coupling by altering sinking rates, giving other organisms more opportunity to feed on deposits and promote the spread of microplastics through the food chain.The purpose of our project is to test how different types of microplastics affect sinking rates of mussel biodeposits. Our hypothesis is that mussels filter microplastic particles differently.The more readily ingested microplastic will lower the sinking rate of the feces more drastically. In our experiment we fed mussels either polystyrene or polyethylene microspheres along with algae, collected their biodeposits, and measured sinking rate. Further, we quantified microplastic and algae found in each type of biodeposit. The selectivity of mussels toward a particular microplastic was determined by the amount of a microplastic present in the feces vs the pseudofeces. The results from this study can help us understand the impact of microplastic pollution and how mussels play a major role in the spread of microplastics. They may also provide insight into which types of microplastic are more readily spread, potentially providing information on how to distribute microplastic waste.

During the Pleistocene Epoch approximately 13,000 years ago, retreating glaciers deposited several stranded icebergs where the wetlands on the north end of the North Seattle College campus lie today. We collected and analyzed several borehole samples within the Meridian Avenue Basin to determine the stratigraphy and identify organic material found within the basin. The stratigraphy of the basin revealed that these features are a result of Vashon Glaciation during the end of the Pleistocene Epoch. Our subsurface core samples exposed a glacial till-lined basin ranging from 3-9 meters deep with overlying layers of gravelly clay, silt, sand and peat. A carbon date we retrieved from organic material within the peat indicates the sediment was deposited during the last glacial recession. The fill of the Meridian Avenue Basin and the carbon date retrieved indicate that it was created by an iceberg stranded in a shallow, post-glacial lake during the last ice age. Unlike typical kettle basins, load-induced subsidence of this iceberg into saturated lake-floor sediments created its shape and depth. The basin lacks the characteristic outwash depositions seen in kettle lakes and appears to be unique, suggesting the geologic processes which may have created the basin seldom occur and are poorly understood. Researching the origins and stratigraphy of the Meridian Ave basin will help advance knowledge of this possibly rare periglacial phenomenon.

Ever since they first appeared during the Late Cretaceous, members of the palm family (Arecaceae) have been ubiquitous in the fossil record. Traditionally, palms have been considered a key indicator of warm climates. In addition to leaf macrofossils, fruit, and pollen, palm phytoliths have gained utility as paleoecological indicators. Phytoliths are microscopic silica bodies accumulated in the tissues of many plants. Different plant taxa have unique phytolith morphologies, making them useful diagnostic tools. However, palm phytoliths currently lack diagnostic resolution below the family level, limiting our ability to fully utilize these powerful tools. The goal of our project was to increase this resolution by analyzing the morphology of phytoliths from across the entire Arecaceae family in more detail than has been possible before. We used confocal microscopy to take sharp, high-resolution images of palm phytoliths. Using these images, we took several key measurements, to which we applied multivariate ordination methods. Our analysis allowed us to test how well we can differentiate palm subclades within Arecaceae based on phytolith morphology. Ultimately, we hope to use this information to determine when and where specific clades of palms appeared in the fossil record, increasing our understanding of the evolution of the palm family. This will also allow us to describe past environments in more detail based on palm phytoliths, including estimating more specific climate parameter ranges, and characterizing particular biomes and habitats.

The spread of grasslands 26-22 million years ago has been linked to global climate changes in the late Oligocene to early Miocene. The pattern of vegetation change was established analyzing assemblages of microscopic plant silica (phytoliths) extracted from sediment samples from the Central Great Plains of North America. It is often presumed that as open-habitat grasses became abundant, vegetation structure concurrently transitioned from closed forests to open landscapes. However, recent work in the Cenozoic of Patagonia has pointed to a decoupling of grass dominance and habitat openness, each independently driven by climatic conditions. We set out to test if a similar decoupling occurred in the Central Great Plains by means of an a-taxonomic phytolith proxy using phytoliths produced in non-grass epidermal cells. Work in modern plants and soil assemblages has shown that the size and degree of undulation in these phytoliths (quantified by, respectively, Phytolith Area, PA, and the Phytolith Undulation Index, PUI) is correlated with the amount of light in the environment, reflecting habitat openness (measured as Leaf Area Index, LAI). We measure the PA and PUI of phytolith samples from Nebraska, dating 35 to 17 Ma, to reconstruct the regional LAI over time and place time constraints on the opening of habitats. By comparing this timeline to that of the rise to dominance of grasses, we hope to better understand changing vegetation and linked climatic conditions in Cenozoic North America.

CD8+ T-cell exhaustion during chronic human immunodeficiency virus (HIV) infection is characterized by increasing expression of exhaustion markers on the cell surface that lead to decreased function, greatly diminishing immune responses and therapeutic vaccination efficacy. Blocking the activation of one such marker (PD-1) using a monoclonal antibody (aPD-1) can help reverse exhaustion. We hypothesized that dosing with aPD-1 would boost the immune system and decrease expression of certain exhaustion markers on CD8+ T-cells throughout infection in order to improve therapeutic vaccine responses. To investigate this hypothesis, we studied how exhaustion changed over time in simian-human immunodeficiency virus (SHIV)-infected rhesus macaques treated with a combinatorial therapeutic regimen consisting of a conserved-elements vaccine to circumvent viral mutants, GS986 to reverse latency, CCR5 gene editing to prevent viral entry, aPD-1 to reverse T-cell exhaustion, and antiretroviral treatment. We characterized exhaustion in peripheral blood mononuclear cells (PBMC) with surface staining and flow cytometry, focusing on markers of exhaustion including PD-1, CTLA-4, LAG-3, TIGIT, and TIM-3 at various timepoints throughout SHIV infection and therapeutic vaccination. We observed higher CD8+ T-cell vaccine responses in animals receiving aPD-1, compared to animals that were vaccinated but not given aPD-1, suggesting aPD-1 dosing improved vaccine responses. We did not observe any significant correlation between PD-1 signaling and expression of other exhaustion markers, suggesting that blocking PD-1 does not reduce exhaustion by decreasing the expression of other exhaustion markers. However, we found a significant negative correlation between CD8+ T-cell vaccine responses and the expression of TIGIT (Spearman r= -0.75, p=0.007). As reduced TIGIT on CD8+ T-cells correlated with increased vaccine responses, there may be a role for dual TIGIT and PD-1 blockade in future studies. Defining the role of CD8+ T-cell exhaustion in therapeutic vaccine immunogenicity and efficacy is crucial to improving combinatorial immunotherapy towards a cure for HIV.