Alzheimer’s Disease (AD) is a neurological disorder that destroys memory and other cognitive functions. Several scientific findings have connected dysfunctional microglia, a type of immune cell, to AD progression. We created an agent-based model to simulate the interactions between microglia and their environment, addressing dysfunctional microglia's effect on AD. Our model represents a two-dimensional slice of the hippocampus, depicting microglia's ability to move, metabolize glucose, and interact with the blood brain barrier and amyloid beta plaques. We applied treatments of metabolic boosting and exercise to our model to study how varying treatment intensities can impede AD progression.

Mapping the Sierra Nevada HSU advanced geospatial students map a variety of topics to accompany text in a forthcoming book about Environmental Issues in the Sierra Nevada.

Patrick’s Point State Park has experienced a tremendous growth of English Ivy that has causing a damage to park resources. The goal of this study was to accurately map English Ivy habitats, estimate coverage, and survey English Ivy colonization effects on tree trunks. The results showed that the English Ivy growth has decreased from 8.0 acres to 6.5 acres between 2015 and 2016 respectively due to park restoration activity supported by volunteer organizations. The English Ivy growth on tree trunks was significant for Western Hemlock and Sitka Spruce. With this project the park will be able to locate the most English Ivy spots that require attention, and monitor their growth rate.

We reviewed current research articles examining the complex relationship between gut microbiome and mood regulation in people. In order to collect our data, we completed a literature review on this topic. We found that there is a very strong relationship between the gut microbiome and mood in people. We observed mental health factors in relationship to mood such as stress, anxiety, and depression. As a result, worsened gut microbiome led to worsened mood factors. This topic has high importance due to how new the topic and research is, and how it affects human health, leading to future implications of treating gut microbiome issues more efficiently with the new knowledge on the topic.

Currents can shape the structure and ecology of estuarine environments. Multiyear time series of current data measured by two Acoustic Doppler Current Profilers (ADCPs) in Humboldt Bay, CA, one near the entrance channel and one at the Chevron Port, were analyzed to determine the contributions of the different harmonic frequencies. Spectral analysis of the time series data revealed that the flow is dominated by several tidal harmonics. The three dominant frequencies include M2, K1, and O1, but their contribution varies spatially between the two stations. Additional frequencies in the data indicate interference with topography as well as the more variable wind-induced currents.

Municipal solid waste (MSW) aka. trash , is one of many stressors on global climate change. An estimated 19,832,501 metric tons generated within a year alone in California. Accumulation of trash can spread into creeks and parks.Trash flow can be mitigated through the use of waste and recycling receptacles.This study observers bus stops that are in proximity to selected creeks and parks based on 100, 200, and 300 meter zones of the Arcata Red and Gold Bus Routes.The Red Route buffer zones intersecting greatly with nearby creeks and parks.Community members and stake holders can provide further input where receptacles are most beneficiary for local green-space and city planning cost.

The nitrogen inventory of Humboldt Bay has not been quantified in the last 50 years. Our goal was to compare and contrast the nitrogen content of the surface, sediments, biomass, and water column between Arcata and South Bay. Not only was nitrate, nitrite, and ammonium in the water column and pore water tested, but many other factors including: CTD, biomass, grain size, chlorophyll-a, loss of ignition, CHN, and metals. We used past peer reviewed papers to determine differences between the two study areas, and coupled NOAA cencoos and Wiyot data, with our own testing to get the best picture we could of Humboldt Bay. Testing spanned for three months in 2015: March, April, and May.

Multiyear time series of current data measured by 2 horizontal SonTek/YSI ADCPs placed mid-depth in the water column at 2 different locations in Humboldt Bay, CA, a shallow, tidally-driven estuary in northern California, were analyzed to determine the contributions of different harmonic frequencies within the bay. Spectral analysis of the time series revealed that the currents are dominated by several tidal harmonics. The 3 dominant frequencies include M2, K1, and O1, but their contribution varies spatially between the two station locations. Additional frequencies in the data indicate overtides, as well as potential interference with topography and the more variable wind-induced currents.

Global climate models predict a more variable climate in the future through increased frequency of extreme wet and dry years. Since water is the most limiting resource in the Chihuahuan desert, investigating how semi-arid plants respond to precipitation extremes is pertinent to understanding how desert ecosystems will be altered in the future. To study these responses, I experimentally applied an extreme precipitation treatment to black grama, a dominant desert grass, during June and July 2018 in the Sevilleta National Wildlife Refuge before the monsoon season. This experiment supports black grama's ability to survive in the desert with few precipitation events due to its growth response.

The Arcata Marsh is responsible for treating the wastewater of the City of Arcata so it is clean enough to release into the ocean. After undergoing preliminary processing, treatment ponds are used to remove organic matter and pollutants such as nitrogen and phosphorus from wastewater, using the symbiotic work of plants like the native broadleaf cattail (Typha latifolia), and the nitrogen-fixing and nitrifying bacteria that grow on their roots, to absorb these chemicals from the water. For this experiment, we observed cattail roots and root microbiota at the inlets and outlets of the pond using scanning electron microscopy, looking at the samples with up to 5000x magnification.