Inferring Type II-P Supernova Progenitor Masses from Plateau Luminosities

Connecting observations of core-collapse supernova explosions to the properties of their massive star progenitors is a long-sought, and challenging, goal of supernova science. Recently, Barker et al. (2022) presented bolometric light curves for a landscape of progenitors from spherically symmetric neutrino-driven core-collapse supernova (CCSN) simulations using an effective model. They find a tight relationship between the plateau luminosity of the Type II-P CCSN light curve and the terminal iron core mass of the progenitor. Remarkably, this allows us to constrain progenitor properties with photometry alone. We analyze a large observational sample of Type II-P CCSN light curves and estimate a distribution of iron core masses using the relationship of Barker et al 2022. The inferred distribution matches extremely well with the distribution of iron core masses from stellar evolutionary models, and namely, contains high-mass iron cores that suggest contributions from very massive progenitors in the observational data. We use this distribution of iron core masses to infer minimum and maximum mass of progenitors in the observational data. Using Bayesian inference methods to locate optimal initial mass function parameters, we find M$_{\mathrm{min}}=9.8^{+0.37}_{-0.27}$ and M$_{\mathrm{max}}=24.0^{+3.9}_{-1.9}$ solar masses for the observational data.Comment: Accepted to ApJ Letters. 9 pages, 4 figure

Comparison of Subjective Responses to Oral and Intravenous Alcohol Administration under Similar Systemic Exposures

Objective To test whether an individual's subjective responses to alcohol are similar when the breath alcohol concentration (BrAC) trajectory resulting from oral administration is matched by intravenous administration. Background Individuals perceive the effects of alcohol differently, and the variation is commonly used in research assessing the risk for developing an alcohol use disorder. Such research is supported by both oral and intravenous alcohol administration techniques, and any differences attributable to the route employed should be understood. Methods We conducted a 2‐session, within‐subject study in 44 young adult, healthy, non‐dependent drinkers (22 females and 22 males). In the first session, subjects ingested a dose of alcohol which was individually calculated, on the basis of total body water, to yield a peak BrAC near 80 mg/dl, and the resulting BrAC trajectory was recorded. A few days later, subjects received an intravenous alcohol infusion rate profile, pre‐computed to replicate each individual's oral alcohol BrAC trajectory. In both sessions, we assessed 4 subjective responses to alcohol: SEDATION, SIMULATION, INTOXICATION, and HIGH; at baseline and frequently for 4 hours. We compared the individuals’ baseline‐corrected responses at peak BrAC and at half‐peak BrAC on both the ascending and descending limbs. We also computed and compared Pearson‐product moment correlations of responses by route of administration, the Mellanby measure of acute adaptation to alcohol, and the area under the entire response curve for each subjective response. Results No significant differences in any measure could be attributed to the route of alcohol administration. Eleven of 12 response comparisons were significantly correlated across the routes of alcohol administration, with 9 surviving correction for multiple measures, as did the Mellanby effect and area under the response curve correlations. Conclusion The route of alcohol administration has a minimal effect on subjective responses to alcohol when an individual's BrAC exposure profiles are similar

Group coaching in a large complex organisation: lessons learnt from experience

This article presents qualitative findings from a pilot group coaching program that was conducted within a large Australian public healthcare organisation. Using Nueman’s (2000) three phase coding system and Spector’s (1984) methodology, transcripts were analyzed for key themes (from both coachees’ and coaches’ perspectives) in response to probe questions. These themes included the need for a clear and explicit goal focus; the importance of solid upfront preparation and communication; the vital role of a group coaching process structure; the value of explicit program sponsorship and follow up; and the need to ensure the right people who are genuinely engaged participants