Browse Exhibits (81 total)

Toxic cyanobacteria blooms are increasing in frequency and severity with rising surface-water temperatures. Warming generates a positive feedback on harmful algal bloom  development by promoting toxic cyanobacteria over non-toxic strains, stimulating toxin synthesis, and subsequently triggering toxin release. The release of cyanotoxins into the water column poses a serious threat to water quality and human health. Yet, cyanotoxins rarely accumulate in the water column long-term, suggesting that biodegradation by heterotrophic bacteria may play a role in the removal process. Owing to increased metabolic rates at higher temperatures, microbial-mediated degradation of cyanotoxins may be influenced by warming. However, the effect of warming on the uptake and subsequent biodegradation of cyanotoxins has not yet been evaluated. In this study, we evaluated the ability for heterotrophic bacteria to degrade microcystin produced by a common cyanobacterium, Planktothrix agardhii, across a natural temperature gradient (from 5 to 20° C) during a laboratory incubation experiment. We measured microcystin concentration and bacterial abundance at 0, 6, 12, 24, 48, 96, and 192 hours. We found that microcystin concentration declined over time in all temperature treatments and degradation increased with warming. Patterns of microcystin degradation corresponded with increases in bacterial cell density over time that were enhanced by warming. Bacterial cell density increased most rapidly in the 20°C treatment resulting in the greater microcystin degradation than all other treatments. Degradation of microcystin was lowest in the 5°C treatment where the increase in bacterial cell density was the slowest. Bacterial density and microcystin degradation were similar between 10°C and 15°C treatments throughout the experiment and were consistently between 20°C and 5°C treatments. These results suggest that cyanotoxins can be reduced by microbial-mediated degradation and the rate of cyanotoxin degradation increases with water temperature.

Faculty Mentors: Dr. Allison R. Rober, Dr. Kevin H. Wyatt 

Department of Biology

Undergraduate

Enterprise Virtual Exchange (EVE), is a user-friendly platform that delivers illuminating connections between entrepreneurs, business owners, and specialized resources providers.

Faculty Member: Huseyin Ergin

Computer Science

Undergraduate

Internalizing disorders are characterized by several negative symptoms including stress, anxiety, and mood instability (Ben-Porath, 2012; Duffy et al., 2017). The literature suggests that more women than men are diagnosed with internalizing disorders like depression (Nolen-Hoeksema, 1994). One mechanism that has been supported as influencing this difference is gender stereotypes, which encourage women and men to express emotions differently (Rosenfield et al., 2000). One specific area within the internalizing spectrum where we may see these gender differences is anger proneness. Anger proneness (ANP) is the tendency to become easily angered, upset, or impatient with others (Ben-Porath, 2012). Indeed, there is evidence to suggest that men tend to express anger more externally whereas women tend to express anger more internally (Dawson et al., 2010).

Despite past research on gender differences in internalizing disorders, previous literature has not examined gender differences in specific scales like the MMPI-2-RF ANP scale. Thus, the current study examined whether gender differences exist on the MMPI-2-RF ANP scale. We hypothesized that men would score higher than women. To achieve this goal, we used an archival dataset of college students who scored higher than average on the MMPI-2-RF Emotional/Internalizing Dysfunction scale. The assumption of normality for an independent samples t-test was violated so, we conducted an independent samples Mann-Whitney U test. The independent samples Mann-Whitney U test indicated that women and men endorsed similar levels of anger proneness, p=.72.

The MMPI-2-RF ANP scale captures negative emotional experiences of anger, but not how individuals act on these emotions. So, gender differences in anger may be better captured by the MMPI-2-RF Aggression scale which measures aggressive behaviors in response to feelings of anger. It may be that women and men experience feelings of anger similarly, but act on these emotions differently. For example, one’s culture and adherence to stereotypes affects the extent to which they engage in stereotype-consistent behaviors (Eagly et al., 2019). Thus, we may have a sample who more loosely adheres to gender stereotypes and therefore engages in fewer stereotype-consistent behaviors. Future research should investigate the effect of stereotypes on anger-related behaviors when other characteristics are accounted for.

Faculty Mentor: Tayla T.C. Lee

Department of Psychological Science

Graduate

Harvard Business Review states that new leads should be responded to within 5 minutes to optimize the lead opportunity. In contrast, most businesses take over 24 hours on average to reply to any given lead. This presents an unique business opportunity. In this work, we showcase LeadSigma, a novel workflow that allows any business to respond to new leads. Moreover, we show that with LeadSigma companies can increase their lead opportunity by orders of magnitude.

Faculty Mentor: Huseyin Ergin

Computer Science Department

Undergraduates

Rieske dioxygenases are a class of enzymes found in soil bacteria, that are  known to catalyze aromatic compounds via dihydroxylation to form enantiopure cis-diol metabolites. The regio-/stereoselective nature of enzymes make it a promising tool for synthetic chemistry by discovering  new methods to form complex compounds.

Enzymes can be an environmentally friendly alternative to traditional catalysts by eliminating the need for petroleum based solvents, as enzymes can perform in aqueous solutions, and toxic heavy metals. However, enzymes are limited by their substrate scope and strict selectivity. In order to overcome this, protein engineering has been employed to expand the reactivity of enzymes.

To detect the activity of engineered dioxygenases, a novel assay system for the detection of aromatic substrate metabolites was developed. Here, the cis-diol metabolite was oxidize to form dialdehydes. These aldehydes can then conjugate with a fluorescent probe to give a strong fluorescent signal. However, this metaperiodate fluorescein cis-diol assay (MPFCD) does not give a strong fluorescent signal with aliphatic substrates. Thus, optimization of an assay for aliphatic dihydroxylation for metabolite detection via absorbance was investigated. These throughput assays can allow for distinct determination of engineered Rieske dioxygenase variants that show improved reactivity towards substrates not native to the enzyme.

Faculty Mentor: Dr. Jordan Froese

Department of Chemistry

Undergraduate