Marshall University Music Department Presents a Junior Recital, Sean Price, tenor, with, Mark Smith, piano

https://mds.marshall.edu/music_perf/1673/thumbnail.jp

Does Inflation Provide Natural Initial Conditions for the Universe?

If our universe underwent inflation, its entropy during the inflationary phase was substantially lower than it is today. Because a low-entropy state is less likely to be chosen randomly than a high-entropy one, inflation is unlikely to arise through randomly-chosen initial conditions. To resolve this puzzle, we examine the notion of a natural state for the universe, and argue that it is a nearly-empty spacetime. If empty space has a small vacuum energy, however, inflation can begin spontaneously in this background. This scenario explains why a universe like ours is likely to have begun via a period of inflation, and also provides an origin for the cosmological arrow of time.Comment: Submitted to Gravity Research Foundation Essay Competition; based on hep-th/041027

Detecting Potential Neurotoxic Pseudo-nitzchia Species in the Grand Strand

Pseudo-nitzschia is a globally distributed diatom genus which contains 26 neurotoxin (domoic-acid) producing species. In shallow coastal waters these diatoms are associated with both the development of harmful algal blooms and the bioaccumulation of toxins in shellfish that can impact human health. Environmental DNA (eDNA) samples drawn from the public shellfish harvesting area at Huntington Beach State Park (SC) during the summer of 2021 were PCR- screened for Pseudo-nitzschia species using genus specific primers. The sequences of the recovered amplicons are used to molecularly characterize the species of Pseudo-nitzschia present and their potential to produce domoic acid

Comparison of enzyme kinetics and inhibition of three North American snake venoms

Baseline gelatinase activities of venom from three snake species: Agkistrodon contortrix contortrix (Acc), Crotalus atrox (C. atrox) and Cerastes cerastes (Ccc), were measured using EnzChek® Gelatinase/Collagenase Kit E12055, and found to be similar between Acc and Ccc, while C. atrox venom showed lower baseline activity compared to the other two. Based on Selwyn plots of experimental data, venom from Acc and C. atrox demonstrate enzymatic stability over a wide range of substrate concentrations and reaction times, while Ccc venom demonstrated lower levels of stability under the same conditions. It was also found that the protease inhibitor NNGH inhibits the gelatinase activity of C. atrox venom more than it does for Acc venom. The inhibitory effect on venom gelatinase activity is not affected by enzyme pretreatment with NNGH prior to the gelatinase reaction. The DMSO used in the reaction also has an inhibitory effect, which is greater for C. atrox than for Acc. These results will be useful in understanding reaction kinetics of snake venom enzyme inhibition, which could lead to alternative treatment modalities for envenomation

Raw acceleration from wrist- and hip-worn accelerometers corresponds with mechanical loading in children and adolescents

This is the final version. Available on open access from MDPI via the DOI in this recordData Availability Statement: The data presented in this study are available on request from the corresponding author.The purpose of this study was to investigate associations between peak magnitudes of raw acceleration (g) from wrist- and hip-worn accelerometers and ground reaction force (GRF) variables in a large sample of children and adolescents. A total of 269 participants (127 boys, 142 girls; age: 12.3 ± 2.0 yr) performed walking, running, jumping (5 cm) and single-leg hopping on a force plate. A GENEActiv accelerometer was worn on the left wrist, and an Actigraph GT3X+ was worn on the right wrist and hip throughout. Mixed-effects linear regression was used to assess the relationships between peak magnitudes of raw acceleration and loading. Raw acceleration from both wrist and hip-worn accelerometers was strongly and significantly associated with loading (all p’s < 0.05). Body mass and maturity status (pre/post-PHV) were also significantly associated with loading, whereas age, sex and height were not identified as significant predictors. The final models for the GENEActiv wrist, Actigraph wrist and Actigraph hip explained 81.1%, 81.9% and 79.9% of the variation in loading, respectively. This study demonstrates that wrist- and hip-worn accelerometers that output raw acceleration are appropriate for use to monitor the loading exerted on the skeleton and are able to detect short bursts of high-intensity activity that are pertinent to bone health.Economic and Social Research Council (ESRC

A Comparison of External Loads in Division III Men\u27s Lacrosse Between High Competition Matches and Low Competition Matches

Lacrosse is an open field sport with limited knowledge on the demands of gameplay at the Division III level. The purpose of this study was to investigate the external loads on Division III men’s lacrosse players during NCAA season games. Comparisons were made between the external loads placed on the athletes in top competition versus external loads placed on the athletes in low competition matches. Top competition matches were defined as matches against teams that qualified for the NCAA tournament whereas low competition matches included teams that did not meet top competition requirements. The dependent variables measured included total distance, work rate, intensity, 2D load, and 3D load. Defensive players were found to have significantly higher external load values for total distance (m; p=0.003), work rate (m/min; p=0.006 ), intensity (AU; p=0.071), 2D load (AU; p= 0.039 ) and 3D load (AU; p=0.022), while there were no significant differences (p\u3e0.05) for other positions between competition level. Competition level exerts a higher external load for defensive players, but not attack, midfield, or specialists (goalie, face-off, etc), which may indicate the need for specialized conditioning or active load management to deal with potential fatigue

Predators Are Attracted to the Olfactory Signals of Prey

Background: Predator attraction to prey social signals can force prey to trade-off the social imperatives to communicate against the profound effect of predation on their future fitness. These tradeoffs underlie theories on the design and evolution of conspecific signalling systems and have received much attention in visual and acoustic signalling modes. Yet while most territorial mammals communicate using olfactory signals and olfactory hunting is widespread in predators, evidence for the attraction of predators to prey olfactory signals under field conditions is lacking. Methodology/Principal Findings: To redress this fundamental issue, we examined the attraction of free-roaming predators to discrete patches of scents collected from groups of two and six adult, male house mice, Mus domesticus, which primarily communicate through olfaction. Olfactorily-hunting predators were rapidly attracted to mouse scent signals, visiting mouse scented locations sooner, and in greater number, than control locations. There were no effects of signal concentration on predator attraction to their prey’s signals. Conclusions/Significance: This implies that communication will be costly if conspecific receivers and eavesdropping predators are simultaneously attracted to a signal. Significantly, our results also suggest that receivers may be at greater risk of predation when communicating than signallers, as receivers must visit risky patches of scent to perform their half of th

Closeness in a physics faculty online learning community predicts impacts in self-efficacy and teaching

Community-based professional development initiatives have been shown to support physics faculty in their adoption of research-based instructional strategies. Hoping to better understand these initiatives' mechanisms of success, we analyze the results of two surveys administered to a faculty online learning community teaching a common physics curriculum designed primarily for pre-service elementary teachers. We use social network analysis to represent the faculty network and compare members' centrality, a family of measures that capture the prominence of individuals within a network, to their reported experience in the community. We use a principal component analysis of different centrality measures to show that closeness, a measure of how closely connected a person is with every other person in their network, is the most appropriate centrality measure for our network. We then compare regression models according to Bayes factors to find relationships between participants' closeness and their survey responses. We find that participants' self-efficacy, as well as their sense of improvement to their teaching and sense of benefitting from the community, are predictors of their closeness with other participants and thus their breadth and depth of participation in the community. Our results are consistent with other studies that have highlighted interactions among faculty as key components of successful professional development initiatives. They may also be useful for designers of similar communities as they decide how to prioritize time and resources to meet specific goals