Investigating Shotgun shell and wad waste around Humboldt Bay

College of Natural Resources & Sciences

Shotguns are often used for hunting and when they are fired, they produce a plastic wad and shell that are ejected and often left behind. In order to estimate the abundance of shotgun wads and shells, eight randomly selected sites around Humboldt Bay were sampled once each during the month of March 2022. The sites sampled included the beach and bay side of the Samoa Peninsula, Arcata, and Eureka. At these selected sites, 400-m2 was inspected for wads and shells. While sampling at each site, trash was collected and weighed. Only one shotgun wad and one shell was collected at two different sites, for an abundance of 0.25 wads and shells per 100 m2, and an average of 0.26 kg of trash per 100 m2

Investigating the Genetic Diversity of Immune Genes in Non-Native Populations of American Bullfrogs (Lithobates catesbeianus)

College of Natural Resources & Sciences

The American Bullfrog (Lithobates catesbeianus) is a highly invasive species that has successfully colonized different habitats around the world. Our project’s objective is to isolate and characterize the genetic diversity of a rapidly evolving immune gene in an invasive bullfrog population in California’s Sutter National Wildlife Refuge. The level of genetic variability in a population may help determine how resistant a population is pathogens and how persistent an invasive population may be over time. We compared the genetic diversity within this population to that found in other frog populations, including both native and non-native populations.

Investigating the Heterogeneous Catalysis of Volatile Organic Compounds by Environmental Metal Oxides

College of Natural Resources & Sciences

Environmental metal oxides have multiple chemical interactions with natural and anthropogenic organics in the atmosphere. Volatile organic compounds (VOC) and pollutants such as; pesticides, fertilizers, and nitrates are introduced to the atmosphere through similar means as well as incomplete combustion from vehicles and industrial processes. Metal oxides like titanium (IV) oxide, TiO2, have photocatalytic effects that can further oxidize VOC and other adsorbed species. Acetone is a frequently measured VOC in the atmosphere. In our research we study how acetone and other organic species adsorb onto TiO2 and react catalytically in the presence of atmospheric oxidants such as ozone.

Investigating the Timing of Seed Maturation Inside Conifer Cones

College of Natural Resources & Sciences

Evidence of high density non-serotinous recruitment post-fire questions if seed dispersal from a live tree is solely responsible. Studies suggest that seed maturation occurs before the cone scales reflex, and it’s possible that cone scales act as a protective barrier during fire, such that mature seeds are protected and remain germinable. If cone scales adequately protect seeds, then an aerial seed source post-fire is available for recruitment, relative to seed maturation and time of fire. This research aims to determine the timing of Pinus contorta ssp. latifolia seed maturation within a coniferous cone and its relationship to degree days.

Investigation into Cyanide Levels at the Arcata Wastewater Treatment Facility

College of Natural Resources & Sciences

The City of Arcata Wastewater Treatment Facility (AWTF) was issued a National Pollution Discharge Elimination System permit in 2019, which set a water quality objective for cyanide of 1.0 µg/L to protect saltwater ecosystems. Since enactment, the AWTF has exceeded the daily maximum effluent limit. This study used distillation and colorimetric analysis to investigate cyanide formation by comparing the cyanide levels in preserved and unpreserved samples taken concurrently with monitoring samples that were sent to a certified lab. Results found that found that unpreserved samples had no detectable levels of cyanide while preserved samples demonstrated a cyanide concentration of 0 to 1.7 µg/L.

Investigation of the Ubiquitin Proteosome’s Role in Tau Proteostasis and Tauopathy as Regulated by Cholesteryl Esters

College of Natural Resources & Sciences

Many neurodegenerative diseases are characterized as cholesterol metabolism or storage disorders. Recently, the drug Efavirenz was implicated as a mediator of cholesterol-induced pathology in AD SC- based models. It restores function of MAP, tau, by mitigating cholesterol’s disruption of the UPS, which facilitates tau proteostasis. In this study, we are investigating the mechanistic target of cholesterol leading to UPS dysfunction. We are using human SC-derived neurons to model UPS dysfunction at different regulatory levels and determine which stages can be rescued with Efavirenz treatment. We will use this drug to aid in the complete characterization of cholesterol-mediated tauopathy.

Isolation & Nanodisc Assembly of Submitochondrial Particles

College of Natural Resources & Sciences

The mitochondrion is a subcellular location for varied metabolic processes and pathways relevant to undergraduate biochemistry courses at Cal Poly Humboldt. At the core of such pathways are integral membrane proteins (IMPs) whose structure and enzymatic activity can be examined to better understand not only their overall function, but also the role of specific subunits. One such enzyme is cytochrome c oxidase (complex IV). Nanodiscs are invaluable tools for examining IMPs. In this experiment, we isolated mitochondria and submitochondrial particles for incorporation into nanodiscs. Future work will include purification and selection for nanodiscs containing only cytochrome c oxidase.

Isolation and Initial characterization of antibiotic-producing bacteria from Northern California's Redwood Forest

College of Natural Resources & Sciences

In order to fight the increasing antibiotic crisis, an experimental lab isolated bacteria from the Redwood Forest. From soil and air, 47 isolates were extracted from the Redwood Forest and tested for inhibition against the six deadly ESKAPE pathogens. We sequenced the 16s rRNA gene to identify the bacterial species. Isolates that had identical 16s rRNA genes inhibited different pathogens, possibly leading to the discovery of a novel antibiotic producing bacteria.

Jet propulsion at the smallest size scales: Kinematics and fluid dynamics of swimming Siphonophores

College of Natural Resources & Sciences

Siphonophores (Cnidaria: Hydrozoa) inhabit pelagic waters where representative species occupy depths ranging from the surface to the abyss. Locomotion by siphonophores is achieved by nectophore muscular contractions, which generate vortex ring wakes similar to jet-propelled medusa and squid. Using high-speed video analysis, we compare the kinematics and characterize wake structures of two different species of siphonophores during straight and turning swimming. By extracting the kinematics of individual nectophores, we quantify the formation time (T*) to characterize the jet wake. We show the T* generated by swimming physonect siphonophores are larger than other jet-propelled swimmers.

Juvenile Coho Salmon Life History Variants in Humboldt Bay Tributaries

College of Natural Resources & Sciences

We are assessing movement of juvenile Coho and adult straying among Freshwater Creek and two other Humboldt Bay tributaries using PIT tags and mark-recapture multi-state modeling. As salmon habitat becomes more fragmented through human actions, the need to better understand interactions between connected salmonid populations only grows. This research will focus on quantifying the frequency of juvenile dispersal between nearby watersheds to evaluate the need for changes in both management and monitoring. If there is significant movement between these watersheds, effective management and monitoring strategies of Freshwater Creek may need to be expanded to include nearby streams.