Natural & Physical Sciences
Samson Colburn, Samson_Colburn1@baylor.edu
Baylor University, with Dr. Ben Rose
Interstellar Dust's Effect on Type Ia Supernovae Luminosity-Distance Relation
Type Ia supernovae are known to be standard candles. We seek to refine this relation between luminosity and distance for nearby stars. We use 92 such supernovae within a redshift of 0.08. First, we will correct the world coordinate system for each observation since we previously noted a discrepancy between the observation location and the location confirmed by other sources. Then, we will record amounts of common elements (such as \ha, \ion{N}{2}, and \ion{O}{3}) to confirm whether the shift in the world coordinate system is appropriate and determine whether any dust appears to affect our observation of each supernova. Finally, we will determine how this dust affects the standard candle luminosity-distance relation. By refining this relation for Type Ia supernovae, astronomers can more accurately determine distances to nearby objects. This will also help astronomers determine how dark energy plays a role in the universe.
Jaden Rankin, jlr1427@mavs.uta.edu
University of Texas Arlington, with Dr. Alison Ravenscraft
Toxin Lethality and Symbiont-Mediated Detoxification of Phenethyl Isothiocyanate in Grasshoppers
Plant-insect interactions have a profound effect on the adaptation of plants and insects alike, as well as a greater effect on the food web they are a part of as a whole. Plants adapt to insect herbivory, and insects adapt to the plants defenses in turn. Plants create secondary plant metabolites that can be a deterrent or even toxic to insects. There are many mechanisms that insects have to remedy this, but an emerging idea is that insects form symbiotic relationships with the bacteria housed in their guts that break down the toxins in their food. Phenethyl isothiocyanate (PEI) is a toxin produced by plants in the Brassicaceous family after the leaf tissue is damaged. My research will investigate whether PEI has a significant effect on the the chewing insect Schistocerca americana, as well as if the gut microbiome has an effect in remedying these negative effects of PEI on the insect, which could provide evidence that there are symbionts the insect could acquire that help degrade the toxin in their diet. This is achieved by feeding the insects toxin treated diets, as well as feeding them a known bacterial degrader to act as a gut symbiont to test for an effect. My work has suggested that this toxin’s consumption by the chewing insect Schistocerca americana leads to a decrease in mass gain over time despite similar plant consumption as the control at lower PEI concentrations, and increased mortality in higher concentrations.
Oscar Reyes Parker, oscar.hernandezreyes@my.utsa.edu
University of Texas San Antonio, with Jesús A. Romo, Ph.D.
Exploring the Phenotypic Diversity of Environmental Nakaseomyces Glabratus
Nakaseomyces glabratus is an opportunistic pathogenic fungus and common colonizer of the humangastrointestinal (GI) tract. It is also found in the environment, where it is exposed to a wide range of stress conditions (e.g., high temperatures, desiccation, predators, antimicrobials). Despite its clinical importance, asignificant gap in knowledge exists about how adaptations to distinct environmental conditions influence virulence in Nakaseomyces glabratus. We hypothesize that adaptation to non-mammalian environments influences clinically relevant traits such as antifungal susceptibility and biofilm formation. This project aims to phenotypicallycharacterize environmental isolates of Nakaseomyces glabratus to determine the influence of their environment on clinically relevant traits. Isolates yHKYM15 (sand), yHK744 (fungi), yHSLC38 (berries), and yHMicronic 34723(unknown origin) were cultured at 30 °C and 37 °C in YPD or RPMI media to determine growth phenotypes. Antifungal susceptibility and biofilm formation assays were performed in RPMI and incubated at 37 °C. TheyHMicronic 34723 and yHKYM15 displayed growth defects at 30 °C in YPD, while all isolates grew comparably at 37 °C. No significant differences in fluconazole, amphotericin, or caspofungin susceptibility or biofilm formationwere detected compared to the controls. In future studies, we will determine their response to stressors (SOS, Caffeine, Calcofluor white), perform biochemical assays (e.g., adhesion), as well as characterize virulence in a Galleria mellonella moth model of infection. Our findings suggest that the virulence relevant traits of Nakaseomyces glabratus are already present before encountering a mammal. However, characterization of a larger collection of isolates is required.