Antimicrobial resistance (AMR) is a rising and critical issue in modern medicine, exacerbated by the overuse of antibiotics in infection treatment, livestock production, and agriculture This has increased the prevalence of antibiotic-resistant pathogens and calls for further definition of the mechanisms of antibiotic resistance The bacterial general stress response (GSR) activates around 200 general stress proteins (GSP) through the transcription factor SigB (Rodriguez Ayala, 2020). The GSR is suspected to be involvement in the development of antimicrobial resistance due to the induction of SigB-regulated genes when bacteria are exposed to antibiotics (Dawan and Ahn, 2022). The Gram-positive cell envelope is the target of numerous antibiotics, such as Fosfomycin and Bactricin. This study aims to investigate the role of the GSR in regulating antibiotic-induced genes in Gram-positive bacteria, specifically Bacillus subtilis, to further understand the molecular mechanisms that contribute to the rise of antibiotic resistance. I will be focusing on cotranscribed genes csbB and yfhO which are predicted to function at the cell membrane. I currently have isolated RNA and designed primers for csbB and yfhO. Once the primers have been tested through qPCR I will continue with reverse transcription and qPCR to measure levels of gene expression.

The Manduca sexta hawkmoth, a proficient pollinator, employs its antennae to efficiently navigate its surroundings. With their antennas highly developed olfactory sense as well as their wide range of odor recognition using their sensory receptor cells, moth antennae are an ideal candidate for developing reliable biosensors. In contrast, commonly used portable artificial sensors are inefficient and inaccurate in chemical detection. To evaluate the moth antenna's effectiveness as a biosensor model, I assessed neural activity of the antenna via an electroantennogram. To do this, I attached the removed antenna to a circuit to measure voltage variations across the antennal nerves during odor stimulation. I then administered a selection of odorants over a determined cycle of durations ranging from 0.2, to 10 seconds inside a wind tunnel. The odorants included floral compounds known to be attractive to moths, and volatile organic chemicals (VOCs) replicating healthy and COVID breath. My findings show strong initial spikes of electrical activity in the receptor cells correlating to odorant release​, favoring shorter durations and both the floral mixture and linalool. Prolonged exposure to odorants caused continuous increased activity in the antennae, with a more pronounced response observed in the COVID VOCs and linalool. These results demonstrate that moth antennas are a suitable model for highly accurate and efficient biosensors, and support the feasibility of implementing them in devices aimed at detecting and identifying substances of interest. Future work will explore COVID-associated compounds and apply machine learning methods for enhanced chemical discrimination in disease diagnosis.

To feed the growing world population, we need to maximize feed efficiency so that cows will produce more milk with less feed intake, while releasing fewer greenhouse gases into the environment. One strategy to maximize the feed efficiency in cows is to increase and maintain peak milk production. One further refined aspect of feed efficiency is a metric known as residual feed intake (RFI) which identifies how well cows convert feed to milk based on the difference between observed and expected feed intake when accounting for production. Cows with high feed efficiency will have a lower RFI and low feed efficient cows will have a higher RFI. RFI is measured in the mid-lactation period, between 50 and 200 days after calving, during which cows achieve peak milk production. Hepatic metabolic health can contribute to the variation of feed efficiency and RFI in cattle. To determine metabolic priority, blood samples were taken from the top and bottom ten percent RFI mid-lactation Holstein cows to quantify long-chain fatty acids in plasma. The objective was to quantify the profile of fatty acids from high and low RFI cows through fatty acid methylation and gas chromatography/mass spectrophotometry. We hypothesize that there will be differential use of long-chain fatty acids between cows of differing RFI status. Understanding the mechanisms of hepatic metabolism and preferential oxidation of long-chain fatty acids may improve the profitability of dairy cows during peak milk production, and aid in developing future nutritional strategies to provide a more sustainable dairy farming.

A species’ diet can provide crucial information regarding community interactions and trophic niches. In diet studies, invasive species are commonly used due to the feasibility of lethal methods, but these methods may not be applicable when studying protected organisms. One species whose diet in its invasive range has been studied via lethal sampling is the barred owl (Strix varia). Barred owls are generalist predators native to eastern North America, but they have invaded westward and are now found in the Pacific Northwest and California. In their introduced range, barred owls outcompete the threatened northern and California spotted owls (Strix occidentalis caurina and S. o. occidentalis) and destabilize western forest ecosystems due to their generalist diet causing negative trophic impacts. Experimental lethal barred owl removals have been conducted in California for the benefit of spotted owls, and these removals have provided a method of examining diets using intestinal contents and DNA metabarcoding. However, lethal sampling is not feasible when researching the diets of threatened birds such as spotted owls. Here, we intend to assess the use of beak and talon swabs, a non-invasive sampling method, in diet analyses by comparing the diet composition recovered from swabs to intestinal samples using DNA metabarcoding of barred owls. We sampled 77 barred owls (37 females and 40 males) collected in coastal California and extracted DNA from their swabs and intestinal contents. Our future work includes extracting and metabarcoding DNA from California spotted owl swabs collected during bandings to obtain preliminary diet information.