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  1. Free, publicly-accessible full text available April 1, 2023
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  3. The effectiveness of social distancing as a disease-slowing measure is dependent on the degree of compliance that individuals demonstrate to such orders. In this ongoing research, we study outdoor pedestrian activity in New York City, specifically using (a) video streams gathered from public traffic cameras (b) dashcam footage from vehicles driving through the city, and (c) mobile phone geo-location data volunteered by local citizens. This project seeks to form a multi-scale map of urban mobility and space occupancy under social distancing policy. The data collected will enable researchers to infer the activities, contexts, origins, and destinations of the people inmore »public spaces. This information can reveal where and, in turn, why stay-at-home orders are and are not being followed. As a work in progress, it is yet too early for detailed findings on this project. However, we report here on several unanticipated factors that have already influenced the course of the project, among them: the death of George Floyd and subsequent protests, data collection challenges, changes in the weather, and the unexpected nature of the progression of COVID-19.« less
  4. Neutrino-driven winds following core collapse supernovae have been proposed as a suitable site where the so-called light heavy elements (between Sr to Ag) can be synthetized. For moderately neutron-rich winds, ( α,n ) reactions play a critical role in the weak r process, becoming the main mechanism to drive nuclear matter towards heavier elements. In this paper we summarize the sensitivity of network-calculated abundances to the astrophysical conditions, and to uncertainties in the ( α,n ) reaction rates. A list of few ( α,n ) reactions were identified to dominate the uncertainty in the calculated elemental abundances. Measurements of thesemore »reactions will allow to identify the astrophysical conditions of the weak r process by comparing calculated/observed abundances in r-limited stars.« less