Antimicrobial action of micro- and nanoscale ZnO particles has been documented, but the fundamental physical mechanisms driving these actions are still not identified. We hypothesize that one of the key mechanisms behind the antibacterial action of ZnO is rooted in interactions between ZnO surfaces and extracellular material. An investigation was done of the biological components of that interaction using diffusion theory and more specifically Brownian motion computational models to look at the interaction of Zn+2 and O-2 ions with staphylococcus aureus bacteria. The analysis allowed us to find a correlation between the thickness of the staphylococcus aureus bacteria and the amount of the zinc and oxygen ions present in the solution.

Nano- and microscale zinc oxide (ZnO) have demonstrated potential for applications in electronic, pharmacological and chemical industries among others. At these scales, surface properties dominate, rendering surface defects highly influential. Consequently, understanding of defect- related phenomena are crucial to achieving impactful figures of merit. Many optoelectronic properties of ZnO relevant for applications have been linked to defect-related visible luminescence. Its fundamental origins are still being debated, with attributions to oxygen vacancies, zinc vacancies, oxygen antisites, donor-acceptor pairs, etc. In our studies, we contribute to this discussion by probing the relationship between crystal morphology and this luminescence. We conducted optoelectronic studies to characterize the effects of remote oxygen plasma treatment on hydrothermally-grown microscale ZnO samples with controlled morphology as a means to help elucidate the nature of the visible emission. We report on the observed changes in the photoluminescence spectra indicative of the relationship between surface defects, morphology, and electronic structure of ZnO.

Fifty percent of stars in the night sky are actually binary star systems, but finding and characterizing them requires significant data, time, and analysis. Studying the brighter star of the pair is fairly straightforward, but the secondary is commonly hidden. Using the infrared spectroscopy data from the Sloan Digital Sky Survey combined with the WIYN Open Cluster Survey, we create a longer baseline with which we can better characterize these stars. The Joker, a new Monte Carlo analysis technique, will help us reveal the hidden binary stars by producing solutions for the orbits of the systems. By finding new binary stars, we can better understand the demographics and composition of our chosen star cluster, NGC 6819, and also learn more about each individual companion of the systems.

Nostalgia, a sentimental longing for the past, increases prosocial behavior. Research has demonstrated that when a former competitive athlete reflects on their time participating in their sport, they experience feelings of nostalgia. Applying the prosocial nature of nostalgia to an athletic domain, it was hypothesized in the current study that sport-specific nostalgia would predict greater sportsmanship attitudes among athletes. To test this, we primed former competitive athletes with sport nostalgia by instructing them to write about a memory from playing their sport. Then they completed items about their sportsmanship attitudes, such as respecting opponents and officials. Results showed that nostalgia-primed participants reported greater sportsmanship attitudes compared to a control group. This is consistent with research showing that nostalgic reflection increases prosocial attitudes and behavior. In future work we plan to examine these findings in current competitive athletes to give further insight into the role that nostalgia plays in sport settings.

Background: Reward loss is accompanied by a stress response affecting emotion and health. Problem: A comprehensive map of brain activity, or connectome, during an episode involving reward loss remains to be worked out. A connectome is being developed using the protein c-Fos expressed in recently activated neurons. Method: Experimental animals were exposed to reward loss (high-to-low sucrose and pellet downshift), whereas control animals had access only to the small or only to the large reward. c-Fos expression was measured in brain slices obtained after the reward loss event using immunohistochemistry. Brain activity levels in experimental and control animals were determined based on c-Fos expression in several key brain areas. Results: c-Fos expression was found to be higher in areas involved in negative emotion and lower in areas involved in reward processing in downshifted vs. unshifted groups. Contribution: This novel approach will continue to help identify the brain connectome underlying reward loss, that is the set of excited and inhibited areas when the organism is experiencing a loss.