Anthropogenic Noise and Song Variation in the American Robin

Trent Townsend, Wildlife Undergraduate Student

College of Natural Resources & Sciences

This project explores how American Robins change their songs in response to human-made noise. I recorded robin songs across urban and quiet areas in Humboldt County to see if louder environments caused them to sing at higher pitches or volumes. Using sound analysis tools, I compared changes in song frequency and amplitude with background noise levels. This research helps us understand how noise pollution affects bird communication and can guide efforts to make urban spaces more wildlife-friendly.

Aquaponics in the classroom, a students' perspective

College of Natural Resources & Sciences

Aquaponic systems are a combination of hydroponic gardening and a recirculating aquaculture system, which is a very efficient way to produce marketable products for growers. Humboldt State University’s (HSU) aquaculture class had the opportunity to assemble an aquaponics system (Nelson and Pade, Inc.) for the first time. Our class was provided with the equipment that allowed us to demonstrate our abilities in constructing a fully functional aquaponics system. From the knowledge acquired in the academic setting, we were able to create a hands-on, tangible system. White Sturgeon were grown in the system along with a wide variety of vegetables with great success.

Around the Bay in 80 Days: Investigating the Relationship between Bird Diversity and Plants

Quinlan House, Wildlife Undergraduate Student

College of Natural Resources & Sciences

The goal of this study was to investigate the relationship between plant species richness and bird diversity within the area of Humboldt Bay situated in north-western California. Humboldt Bay hosts a unique array of natural areas such as redwood forests, coastal dune forests, and wetlands. We examined the effect of plant species richness and diversity on bird diversity in these three habitats around Humboldt Bay by conducting point counts, plant species censusing, and plant density sampling across 10 plots at each habitat.

ASR Membrane Protein and ApoA1 Detection in Nanodisc via Western Blot Analysis

College of Natural Resources & Sciences

Anabaena sensory rhodopsin (ASR) is a prokaryotic photoactive transmembrane G protein coupled receptor extracted from the cyanobacterium Nostoc. The potential for ASR and its transducer, ASRT, to transcribe/translate prokaryotic genes into products by light signals is an extremely attractive possibility for future membrane research. Nanodiscs are a useful tool for studying membrane proteins because they serve to create a stable amphipathic environment. In the present study, 6x-His ASR has been extracted, isolated, purified, and inserted into a MSP nanodisc with ApoA1 and DMPC. We examine ApoA1 insertion into the nanodisc via SDS-PAGE and chemiluminescent western blot analysis.

Assaying the Substrate Activities and Enantioselectivities of Recombinant Flavin-Dependent Monooxygenases toward Aryl Sulfides

College of Natural Resources & Sciences

Certain Flavin Monooxygenases (FMO) are enzymes with the potential to catalyze single-enantiomer oxidation of aryl sulfides to chiral sulfoxides. Aryl sulfoxides have a wide array of pharmaceutical and agricultural applications, but many of these enantiomers have yet to be selectively and efficiently synthesized. The enzymes examined in this study are FMOs from Mus musculus, Xenopus tropicalis, Homo sapiens, and BVMO4 and BVMO24 from Rhodococcus jostii RHA1. The genes were cloned into a vector for expression in Escherichia coli and whole-cell mediated reactions with various aryl sulfides were performed to determine their activity toward the substrates and to determine the enantioselectivity.

Assessing and mitigating metabolic response of HEK293 cells to cytotoxic metals using ascorbic acid

Elizabeth Kowalski, Biological Sciences Undergraduate Student

College of Natural Resources & Sciences

We examined how HEK293 kidney cells responded metabolically to heavy metal poisoning by cadmium chloride (CdCl2), aluminum chloride (AlCl3), and cesium chloride (CsCl) using two fluorometric assays (resazurin and MitoTracker). We then attempted to mitigate adverse effects by treating these cells with ascorbic acid (vitamin C).

Assessing nocturnal habitat selection of small mammals on an urban-rural gradient using camera trapping

College of Natural Resources & Sciences

Urban development forces city and town boundaries to encroach further into wildland habitats and natural landscapes all over the world, causing immense habitat loss and fragmentation. Human-wildlife conflict with mesocarnivores (skunks, foxes, raccoons, etc.) increases as rising rural population densities push more small mammals into anthropogenic areas. This senior thesis study uses trail cameras to assess habitat and resource use vs. availability along the wildland-urban interface among nocturnal small mammals to determine presence of selection.

Assessing Responses of Intertidal Communities to Ocean Acidification and Hypoxia in Northern California

College of Natural Resources & Sciences

During bouts of strong upwelling nearshore areas in northern California can experience extended periods of hypoxic, corrosive waters due to a relatively narrow shelf and poleward shoaling of isother ms. To assess the response of intertidal communities to these conditions we established and surveyed a series of intertidal sites in Humboldt County that vary in the extent of nearshore mixing and are likely to vary in exposure to hypoxia and low pH conditions. We report the results of initial surveys of our sites, including data on sea star wasting disease, and relationships to variation in temperature, salinity, pH and dissolved oxygen.

Assessing Uncertainties in a Flow Injection Analysis Method for Trace Concentrations of Iron in Seawater

Elijah Vestal, Geology Undergraduate Student

College of Natural Resources & Sciences

Iron is an essential nutrient in biological systems, and is the limiting nutrient in about ⅓ of the surface ocean. We investigate the flow injection method of Lohan et al., 2006, with modifications described in Biller et al., 2013 to analyze nanomolar concentrations of iron in seawater. In this work we focus on quantifying and understanding the uncertainties in the measurements and the signal of the blank by adjusting the method in four distinct ways.

Astronomy Education Research

College of Natural Resources & Sciences

The basis of our research is to assess why learning gains are low within introductory astronomy courses and how scores can be improved. Examining pre and post scores from an Astronomical Diagnostics Test we were able to examine learning gains of fifty-six students. We used Hake’s normalized gain formula to quantify learning gains. The average learning gain found was 0.20 and the highest gains fell among questions such as phases and position of the moon, eclipses, and seasons on Earth, with gains between 0.5-.64. Because Hake’s normalized gain formula is biased, we are looking into other methods of quantifying our data.