Anthropogenic nitrogen (N) emissions have caused an increase in global N deposition, and the northeastern United States is a N deposition hotspot. Nitrogen deposition could impact soil microbial abundance because most soil biota evolved under low N conditions. Soil microbes are key to many ecosystem processes such as organic matter decomposition, which makes nutrients available for plant growth. Therefore, understanding the factors controlling microbial abundance is critical for being able to predict ecosystem processes. We hypothesized that fungal and bacterial abundance and the fungi:bacteria ratio in soil would decrease along a natural N deposition gradient in the northeastern US, and be further reduced by fertilizer application. To address our hypothesis, we collected soil from eight different sites, six of which had experimental plots where N fertilizer had been added. At each site, we collected soil from four ambient or control plots and, if available, four fertilized plots (48 total plots). We measured microbial abundance using phospholipid fatty acid analysis (PLFA). We compared microbial abundance in fertilized to control plots using t-tests, and we analyzed changes in microbial abundance along the natural N gradient using regression analysis. We found that ambient N reduced bacterial abundance (p = 0.03, R² = 0.08), but it did not affect fungal abundance (p = 0.17, R² = 0.02). Fertilizer had no overall effect on fungal (p = 0.72, t = 0.36) or bacterial abundance (p = 0.91, t = -0.12). However, fertilizer did reduce bacterial (p = 0.02, F = 5.6) and fungal (p = 0.02, F = 5.8) abundance at high levels of ambient N deposition. In conclusion, our study showed that soil microbial responses to fertilizer in the northeastern US depend on the background levels of atmospheric N deposition. 

Biochar is used as a soil amendment and is created from plant biomass through pyrolysis. Biochar is thought to help plants grow by increasing the fertility of soil as well as impacting water retention in soils. This led to the question: Does biochar increase the water retention of soils found in the Lower Yakima Valley, allowing for a reduction in the amount of water that is needed to grow bell pepper plants in this water-stressed region? This research delves into the effectiveness of biochar by testing water level usage in real world plants grown in two concentrations of biochar (0.5% and 1%) applied to soils trial plots located in the Heritage University Research Farm. A random generator was used to create a split-plot design with three concentrations of biochar (0% or control, 0.5%, 1%) each with three replicates. The spilt-plot contained two different watering schemes. A total of 576 greenhouse grown Capsicum annum plants were transplanted to 18 plots, each plot containing 32 plants. To test the efficiency of biochar in soil water retention, soil moisture data, plant height, dry weight of the plants, and yield abundance were measured. Results indicate that the presence of biochar in soil can lead to increases in biomass of up to 100% in certain conditions. However, there were irrigation engineering complications that led the inability to reliably control the irrigation rates in the two split plots (originally planned for 100% in section 1, 80% reduced flow in section 2). The soil moisture data were inconsistent and highly variable reflecting potential instrument calibration issues, multiple instances of damage to the drip tape leading to water leaks, and persistent problems with the timing mechanisms for watering lines. This experiment led to significant improvement our methods for the following bell pepper research for the following year.

Previous research has shown that biochar is a supplement in fertile soil productivity. Biochar functions as a water and nutrient retention tool. Biochar helps prevent and decrease local eutrophication in local streams and water ecosystems by reducing the amount of fertilizers applied. Moreover, it’s essential in reducing the amount of water used, thus critical with projected looming drought conditions. In order to test the validity of the impacts of biochar in crops growth, we compared the diameter measurements of approximately 270 Capsicum annuum bell pepper plants. We selected bell peppers as our experimental crop for their practicality as an economical, simple crop and their pertinence of larger diameters which was correlated to the soil. According to preliminary results, we recommend the use of biochar as an enhancement product in pepper farming. Future research could explore the impacts of biochar on crop size on the different crops in the region. This research will provide beneficial information about enhancements to current agricultural practices regarding water and nutrient efficiency in crop growth.

Listeners perceive foreign speech as faster than native speech, even when both are the same speed. This phenomenon is called the ‘Gabbling Foreigner Illusion.’ This illusion may occur because language-specific experience is necessary to temporally parse speech into intelligible units as it unfolds over time. Similarly, one study reported that people tap faster to music that is culturally unfamiliar than to music that is culturally familiar. Like the gabbling foreigner illusion, lack of cultural expertise with music might interfere with listeners’ capacity to find temporal units (the beat), leading them to perceive the tempo of the music as faster. We directly addressed the question of whether listeners are less accurate at perceiving the beat and tempo of culturally unfamiliar music as compared to culturally familiar music by asking them to rate the tempo of music from various cultures (West African, American, Indian, Turkish, and Latin). Musical excerpts were presented in pairs and listeners chose which of the two was faster. We also asked listeners to tap along to the music and examined if their tapping speed corresponds to their perceptual judgments of tempo. We hypothesize that listeners systematically rate culturally unfamiliar music as faster than familiar music, suggesting that listeners experience a “gabbling foreigner illusion” for music. In summary, this research is a first step towards investigating how our culture-specific experiences influence our temporal perception of music.

Sea otters (Enhydra lutris), members of the mustelid family, are distributed in the near-shore marine environment along the west coast of North America from southern California to Alaska. Sea otters are unique among marine mammals, in that they bring all captured prey to the surface to handle and consume. This behavior allows scientists to directly observe their foraging and estimate energy intake rates based on time spent at the surface processing and consuming prey (handling time), prey type and size, and dive time. The foraging behavior of sea otters is observed using standardized methods throughout the sea otter’s North American range. One assumption made when calculating sea otter energy intake rates is that the same prey type of a given size is equivalent across regions. However, an anomaly in the handling time of kelp crabs (Pugettia spp.) has been discovered, where Washington sea otters (Enydra lutris kenyoni) handle kelp crabs 1.5-2 times faster than sea otters in California (Enhydra lutris nereies). One hypothesis to explain this difference is that Washington kelp crabs have a lower edible biomass than kelp crabs in California, allowing for faster handling times by sea otters. To explore this hypothesis, I collected kelp crabs at two sites on the Washington coast. I measured and compared kelp crab maximum width and edible biomass to test whether kelp crabs in Washington are an equivalent sea otter prey item to kelp crabs in California. Kelp crabs comprise 20% of the overall diet of Washington sea otters, so accurately measuring the edible biomass of kelp crabs enhances the precision of estimating sea otter energy intake rates. Estimating the energy intake rate of sea otters provides additional information on their population health.

Advances in remote sensing of snowpack in complex terrain have made it possible to accurately determine snow depth at a high spatial resolution. In order to utilize these measurements for water resource management, snow density is needed at a comparable accuracy and spatial resolution. Current efforts to obtain accurate, fine scale maps of snow density focus on modeling it over broad areas that vary in land surface type. In order to validate these snow density models, measurements of mountain snowpack are needed. Snow density varies significantly depending on the local environment of the snowpack, so measurements are needed at a variety of sites. However, many prior field campaigns to measure snow density have a bias towards open sites since they offer many practical advantages to the surveyor. This results in uncertainty in snow density models in forested areas due to a lack of quality measurements for validation. This project improves our knowledge of differences in snow density between forested and open sites through a field campaign at Snoqualmie Pass. Each week throughout the winter, snow density and changes in snowpack depth were recorded. These measurements are then analyzed over the course of the season to look for significant differences between the two sites. Observations of settlement and densification rates are used to inform an empirical model of snowpack density as well. Detailed notes of the field campaign are also taken to document the practices of the study and suggest improvements in methodology related to snowpack measurements at forested sites.

A greater understanding of snow accumulation patterns in our mountains has proven critical in predicting water supply, preventing floods, forecasting avalanches, and generating hydropower. One way to improve this understanding is through study of the melting layer, or the layer within a cloud where falling snow and ice begin to melt into liquid during a precipitation event. The upper bound of the melting layer is the 0°C temperature level, and the lower bound the altitude at which snow has fully melted into rain. This project aims to improve understanding of the melting layer and its variation in thickness and elevation on the windward (southwest) versus leeward (northeast) side of the Olympic Mountain Range. Hypotheses are explored through the analysis of radar imagery on opposing sides of the mountain range, weather balloon profiles of temperature, wind and humidity, and ground observation data - including hourly temperature values from sites throughout the mountains. Results of these data are compared to snow and weather models and reanalysis products such as WRF (Weather Research and Forecasting Model), NARR (North American Regional Reanalysis) and ERA-Interim, to explore the predictability of melting layer behavior for use in hydrologic forecasting. Through analysis of preliminary results, the occurrence of a lower leeward melting level has been captured through vertical temperature profiles that reanalysis products failed to account for. One hypothesized process contributing to this melting layer variability could include the trapping of cold air at lower elevations from continental sources on the lee-side thus lowering the melting layer, and further altering the thickness of the melting layer as this trapped air mixes with the air modified over the windward slopes originating from the Pacific Ocean.

Werk Student Quasar Absorption Disgnostisions (Werk SQuAD), a group of undergraduate students led by astronomy professor Jessica Werk, aims to assemble a database of identified absorption features present in 230 nearby quasars. The purpose of this database is to provide astronomers studying galaxy evolution more information about the circumgalactic medium (CGM) of galaxies. The CGM is a giant halo of matter gravitationally bound to dark matter surrounding a galaxy, acting as a recycling hub for galactic outflows and accreting material. A major limitation to observing the CGM is that it is so diffuse, it is impossible to observe directly via emission. In order to learn more about the CGM, we must rely on other light sources. As light is emitted from a background quasar, the light passes through the CGM of galaxies in its line of sight as it travels to us in the Milky Way. Every CGM the light passes through leaves a sort of fingerprint, as ions from the CGM absorb some of the original light from the quasar, leaving trenches in the data. By figuring out where those absorptions happened and what ions were present, we can gain insight into what systems of gas were encountered on the quasar’s journey to us. With the use of a specialized GUI, we are able to search for ion absorption features in the spectrum. We look for recognizable signatures such as the Hydrogen Lyman series, while checking for other ion absorbers as well. When there are multiple absorbers at a particular redshift, this is often an indication that we are viewing part of a nearby galaxy’s CGM. By identifying these absorptions and linking them to particular galaxies, we are able to better understand the cycle of galaxy evolution.

At one point or another, every student is faced with some sort of academic failure that can in turn have negative impacts on self-esteem or future academic performance. Being able to overcome such obstacles requires resiliency and the ability to view failure as a learning opportunity. Growth Mindset (GM) interventions aim to shift a student’s perception of intelligence as a quality that can be developed over time and enhance their approach to overcoming barriers. Originally, the GM was developed as an evidence-based intervention to be delivered by trained professionals. However, bringing this intervention into the real-world calls for a more feasible and accessible model. To bridge this gap, the current study utilizes the role of teachers as a valuable resource in building capacity within schools to attain sustainable, long-term goals regarding student success. The purpose of our research is to explore how a GM intervention delivered by teachers affects students’ beliefs about the brain’s ability to change (neuroplasticity). This project utilized a randomized control design with longitudinal follow-up to evaluate the efficacy of the GM intervention in comparison to curriculum as usual delivered in a rural district in the Pacific Northwest region. At two separate time points, middle and high school students completed an online self-report survey that assessed three constructs: theory of intelligence (whether intelligence can be changed), effort beliefs (the relationship between effort and outcomes), and learning goals (goals towards improving academic abilities). We hypothesize that students assigned to the intervention would show more positive implicit attitudes towards malleable intelligence, beliefs about effort, and learning goals. By understanding how students view themselves within an educational context, we can improve the measures taken to further engage and empower students. Future research should evaluate the quantitative outcomes of academic performance (i.e. grade point average) in relation to a GM intervention.

 The atoms in the universe are involved in a constant process of enrichment and redistribution. They cycle violently into and out of galaxies over billions of years. This cosmic cycle of baryons creates a diffuse halo of gas, called the circumgalactic medium (CGM), that exists inside the virial radii of galaxies. Characterized by rich dynamics and complex ionization states, the CGM provides galaxies their star-forming fuel by regulating and recycling the gas supply. The CGM is vital to understanding the evolution of galaxies and the universe, but it is difficult to observe directly. Using high-resolution quasar spectra collected by the Cosmic Origins Spectrograph on the Hubble Space Telescope, we identified absorption features found in the spectrum of the quasar. We classified each absorption feature, identifying its species, redshift, velocity dispersion, and density. We discovered several strong hydrogen systems with metal absorption at redshifts where the light from the quasar had passed through a cloud of metal-rich gas. Using the Sloan Digital Sky Survey catalog, we matched our strong hydrogen systems with several galaxies near the line of sight of the quasar. Now we are starting to characterize correlations between the dynamics of gas in the CGM and its influence on the star formation rate of the galaxy it surrounds.

Natural products are often studied as treatments for chronic inflammation. In this study, the activity of the nuclear factor NF-κB pathway, a pro-inflammatory pathway, was analyzed after treatment with three different combination therapies between natural products Artesunate, Cantharidin, Parthenolide, and Withaferin A, which have all been separately shown to inhibit the NF- κB pathway. The combination therapies chosen to test were determined by Systems Biology, a bioinformatics system that uses a collaborative and integrative design from many scientific disciplines to predict how the cells’ biological system change over time and under varying conditions. The combination therapies of interest were: Artesunate and Cantharidin, Parthenolide and Withaferin A, and Cantharidin and Withaferin A. Exposure of Huh7, a human liver cell line, to the combination therapies of interest and TNF-α induced NF-κB activation. Western blot and luciferase reaction were then used to measure how different combination therapies changed NF-κB activation. The three combinations demonstrated different effects of NF-κB. Our findings will have important implications in understanding the human immune responses to diseases and how known treatments could be develop to be more effective.