With respiratory diseases, namely COVID, becoming exceedingly present, new diagnostic techniques are important in delivering quick and accurate results to patients. With the broad aim of creating a COVID breath test diagnostic, the project focuses on building a classifier able to detect various volatile organic compounds (VOCs). I applied a panel of VOCs to the antennae of the moth Manduca sexta and recorded the change in voltage across the antenna over time, also known as an electroantennogram (EAG). After recording the voltage response it is essential to extract important features associated with the response to avoid overfitting in the classifier. Each odor will have a unique dose-response curve. By identifying the pattern of intensity-related response for each odor, I have extracted important information that can be useful in classifying EAGs. Going forward, this project will be scaled to include COVID-related VOCs and multichannel experiments to measure electrical response in multiple areas of the antenna simultaneously. Multi-channel recordings will provide an increased number of important features for the classifier to use in learning the unique voltage signature related to each odor in our panel.
Preliminary data has shown that the administration of floral odors to the antenna elicits unique voltage signatures when recorded in single-channel EAGs. I predict that if we record from two sites in the antenna, we will observe a set of unique dose-response curves relative to the differential expression of olfactory sensors in the base and the tip of the antenna. These sets of dose-response curves may provide our classifier with better parameters to categorize and detect the presence of odors associated with COVID, as two dose-response curves must be consistent with an assigned odor’s electrical signature instead of only one. This may improve our chances of creating a classifier able to reliably differentiate between COVID and non-COVID odors.

Possession Sound, WA, serves as an important foraging area for a group of seasonally resident gray whales Eschrichtius Robustus. This group of predominantly Eastern North Pacific Gray Whales that visit Possession Sound (Sounders) arrive as early as January and continue migrating towards other feeding grounds near May. If the frequency of sounds within the hearing range of these gray whales (50 to 5000 Hz) exceeds comfortable levels, they may have difficulty foraging. To monitor these relationships, we looked at the frequency and amplitude of sound near Mt. Baker Terminal (MBT) in Possession Sound, WA, from January 2021 to May 2021 with a specific focus on sounds from 50 to 5000 Hz. To gather this data, we used a SoundTrap 300 HF hydrophone, which is currently mounted to a dock at MBT. From January 2021 to February 2021, the hydrophone recorded continuously at a 96-kilohertz sampling rate. From March 2021 to May 2021, the hydrophone was set to record the first fifteen minutes of every hour at the same sampling rate. Preliminary research shows that Possession Sound has a consistent prevalence of ambient and intermittent noise within the established frequency range and peak amplitudes as high as 164 dB. This level of noise may have the potential to negatively affect gray whale behavior and foraging success. Future research should be conducted to see how current and future vessel slow-down trials will impact the frequencies and amplitude of local noise. Future research should also include comparing the MBT sound profile to other sites in the Salish Sea to better understand if the amplitude increase is unique to the area or a cause for wider concern.

The interaction between incoming salt water from the ocean, which is driven by tides, and exiting freshwater from rivers drives circulation through estuarine environments. As a result of the interaction between the incoming water and the exiting water, nutrients and sediment are moved around the estuary. This study focuses on the interaction between tides and the Snohomish River as it enters the Possession Sound estuary, located in Everett, Washington. To acquire data, I deployed a boat-mounted acoustic Doppler current profiler (ADCP), which uses sound to measure water current direction and velocity. I collected these data at varying tide stages at three different sites between the Snohomish River’s southern output to nearby Mount Baker Terminal, located 3.6 miles southwest of the river output. I have collected 8 samples over the course of 7 months at both ebb and flood tide stages. Each transect survey lasted 3-6 minutes and collected data from the first 20 meters of the water column. To get accurate analysis of current velocity and direction I split the data into categories based on depth. Preliminary analysis shows a southward current at many sites during all tide stages and depths. This raises questions about the scope of the river influence and the potential for southward currents regardless of tidal stage. However, further analysis of current velocity and river discharge are needed. Due to the complexity of the currents in the area, understanding how the river and the tides are interacting can provide a greater understanding of how these currents are impacting the dispersal of sediment and nutrients throughout the estuary.

Local bathymetry in estuaries strongly affects water current direction and speed. Water current and speed, or the water flow, determine the circulation of nutrients and oxygen within the estuary. To assess the relationship between water currents and slopes in an estuary, I utilized a boat-based acoustic doppler current profiler (RD Instruments Workhorse 600 kHz ADCP) to measure water speed and direction with depth. Based on preliminary analysis, water direction is consistent at surface level but becomes inconsistent beyond that. Speed is mostly between 0 cm/s and 50 cm/s, but becomes more varied beyond 30 meters. However, that may be due to inaccuracies in measurement, as data collection becomes less consistent beyond that depth based on our current ADCP configuration. The average direction of data at each depth doesn’t change significantly with depth. In summary, speed is mostly consistent with depth near a slope, whereas the direction is not. So, the bathymetry may have a greater effect on water direction than speed. For future work, investigating these patterns with higher resolution datasets will shed more light on any potential patterns.

The Everett Marina is a heavily developed area that has significantly altered water flow from the Snohomish River compared to its natural state. Anthropogenic alteration of this environment led to buildups of sediment, which has required dredging at increasingly shorter intervals leading up to the present. In order to explain sediment accumulation in the marina, this study examines the movement of currents and the abundance of sediment using an Acoustic Doppler Current Profiler (ADCP); data were recorded from June 2020 to August 2021 and compared to recent data I recorded from February and March of 2023. I hypothesized that current direction would be variable and speed would be sluggish due to the shallow depth. In addition, I hypothesized that seasonal changes such as snowmelt in spring and rain in winter would impact the velocity of the currents. Because sediment movement is largely impacted by currents, I hypothesized that sediment abundance would reflect seasonal changes in water flow. Analysis of water current data between June 2020 and August 2021 demonstrates a significant correlation between the velocity of North/South currents and the magnitude of tide stages, but river discharge levels appear to have less of an effect on current speed in the marina. The susceptibility of this area to tides more than river discharge suggests that it is easier for sediments to accumulate in one area as opposed to being swept away. Future analysis will compare this past data to the present and investigate potential correlations with sediment abundance.

In the era of Internet of Things, the operation of various kinds of sensors or devices on the shelves in warehouses or supermarkets often requires batteries or complex wire management. To address this issue, we propose a charging solution utilizing the near-field wireless power transfer (WPT) with multiple relay resonators, also known as a multi-hop WPT system. In this study, we designed and simulated several coil geometries for the WPT system to ensure high efficient power can be delivered from a transmitter to a receiver through various coil hopping configurations. After evaluating the trade-off between the coupling coefficient of coils in parallel and series as well as the design complexities, we constructed many unified coils in one geometry. We then measured the coil-to-coil estimated efficiency using the scattering parameter obtained through a Vector Network Analyzer on a foam board shelf. Our results show the efficiency range from 9% to 81% in the worst and best hopping configurations, respectively. Furthermore, we proposed a power efficiency optimization approach to improve the worst hopping configuration by up to 80%. We anticipate that the success of this work will significantly reduce the staff cost associated with the maintenance of wire management and charging systems on each shelf. It will also simplify the assembly process and enhance the accessibility of smart shelves while potentially mitigating environmental impact by reducing battery usage.

Phytoplankton production depends on a number of factors including nutrient availability, water chemistry variables, and light penetration. Previous studies have shown light penetration to be important for submerged aquatic vegetation, the primary producers that support the marine food web and the ecosystem. Possession Sound is a productive sub-basin of the Salish Sea with complex influences on local water chemistry and primary productivity. Given the significance of primary production in a salt water estuary, this study looks at the seasonal relationships between water chemistry and light penetration, measured by photosynthetically active radiation (PAR) in the Possession Sound estuary across three sites. I collected Seabird CTD and YSI EXO profile data as well as PAR sensor results, in Possession Sound from July 2022 through March 2023. Accompanied with historical data collected by past Ocean Research College Academy researchers, I analyzed site dependent relationships as well as the seasonal relationships. Preliminary analyses showed PAR decreasing with higher salinity and turbidity, but increasing with temperature. Limited connection was observed with dissolved oxygen. Studying the relationships among light penetration and water chemistry allows us to better understand the complex relationships among the key factors determining seasonal primary production.

In estuaries and marine environments, eelgrass (Zostera spp.) is considered a keystone species as many marine species depend on the beds for food and shelter. Eelgrass beds also trap sediment, stabilize substrate, reduce wave energy and reduce coastal erosion. The degradation of eelgrass beds can instigate a decline in those species that rely on the eelgrass beds. Eelgrass is traditionally mapped using aerial photographs or diving surveys, which can be time-consuming and ineffective. Another strategy is to use boat-mounted Acoustic Doppler Current Profiler (ADCP), to create transects of eelgrass beds through backscatter data. The purpose of this study is to assess the application of an ADCP to map local eelgrass beds in Possession Sound and determine its advantages over single-beam sonar. I used a boat-mounted RD Instruments Workhorse 600kHz ADCP during transects of a Possession Sound eelgrass bed. Raw data was filtered using Excel to isolate backscatter data for analysis and visualization. These results were compared to the results from a single-beam sonar system. It is expected that the height of the eelgrass and extent of the beds will be seen through the visualizations, even in winter and early spring surveys. A multibeam sonar like an ADCP will be more efficient in mapping a greater area of eelgrass beds as well as providing greater clarity in visualizations than a similar single-beam sonar through the ADCP’s emittance of multiple sound impulses at once.

Unique relationships between photosynthetic active radiation (“PAR”), turbidity, chlorophyll, and dissolved oxygen (DO) can impact primary productivity levels and directly relate to the health of an estuary. Previous studies show that microbial processes depend on PAR and dissolved oxygen. To some extent, this can govern the rate of near-surface mixing, affecting turbidity and the amount of chlorophyll produced. My preliminary results using data from Possession Sound, a salt wedge estuary, show similar patterns. By examining the previous Ocean Research College Academy’s (ORCA) profile data from 2015-2022, I observed that an increase in chlorophyll corresponded with an increase in turbidity. Further, if there is an increase in chlorophyll, there is an increase in dissolved oxygen. From the fall of 2022 to spring of 2023, I collected additional profiles, including PAR data, from three sample locations in Possession Sound. My results show that when PAR is high, chlorophyll levels and turbidity are also high. However, PAR values are inversely proportional to dissolved oxygen concentrations. This means there are correlations among chlorophyll, turbidity, DO, and PAR values with depth. However, PAR can be affected by many factors, so it is difficult to say that any one of these parameters directly relate to PAR values with depth. Future research can examine different parameters affecting PAR with depth, as availability of sunlight and nutrient levels can also affect PAR data.

Microtubules are dynamic polymers of 𝛼- and 𝛽-tubulin subunits instrumental in the organization and division of chromosomes during mitosis. There is an intrinsic structural polarity to microtubules due to the orientation of 𝛼𝛽 heterodimers in the microtubule lattice, so that there is a fast growing plus end and a slower growing minus end. Kinetochores are protein complexes that assemble on chromosome centromeres and attach to microtubules. Proper chromosome segregation relies on kinetochore attachment to the plus ends of microtubules. Kinetochores are thought to initially bind the microtubule lattice and plus end attachments are then achieved by the action of plus end directed motor proteins or microtubule disassembly. While the plus end attachment is essential for mitotic fidelity, it remains unknown if the kinetochores themselves have an intrinsic polarity preference. Using total internal reflectance fluorescence microscopy, we have found that individual kinetochores assembled on centromeric DNA have a strong preference for binding the plus ends of stabilized microtubules in the absence of motor proteins and ATP or microtubule dynamics. Furthermore, using optical trapping we are able to measure the rupture forces of kinetochores on both ends of microtubules and have found that the observed preference for plus ends is matched by a greater binding strength at plus end tips. These results together give insight into how kinetochores could efficiently form plus end tip attachments and how they likely play a part in cell cycle regulation by using tension to sense a correct attachment. A better understanding of the specific mechanisms of kinetochore microtubule binding is valuable for understanding control of mitotic progression and could potentially inform more targeted anti-cancer therapies that focus specifically on dividing cells without impacting regular cell function.

About one-quarter of photosynthetically fixed carbon is cycled through the marine microbial community in the form of metabolites, the intermediate compounds or products of metabolic processes. Marine heterotrophic bacteria are largely responsible for consuming these metabolites as a source of carbon, energy, and nutrients, yet little is known about transporter affinity and uptake kinetics of bacteria for abundant substrates. Homarine is a small, nitrogen-containing, zwitterionic metabolite that is produced by the cyanobacterium Synechococcus as well as some diatoms and haptophytes, where it is thought to function as an osmolyte. Dissolved homarine is present in the ocean at very low concentrations (~1.1 nM in Puget Sound). I hypothesize that these low concentrations are the result of high affinity bacterial transporters for homarine. Homarine can be used as a sole carbon and nitrogen source for OBi1, a marine bacterium isolated from Puget Sound. In this study, I investigate the uptake kinetics of homarine by OBi1 in the lab using the Michaelis-Menten model. I compare the uptake kinetics of OBi1 to similar homarine uptake experiments in the Salish Sea in June 2019. I expect that OBi1 will have a high affinity for homarine uptake and will take up homarine at nanomolar concentrations. I also anticipate that the marine microbial community in Puget Sound will have similar uptake kinetics to those observed with OBi1. Understanding the uptake kinetics of homarine by marine bacteria sheds light on the cycling of homarine in marine environments like Puget Sound and can help us understand the processes that keep the dissolved homarine concentration so low.