ABSTRACT
We conducted a drift-scan observation campaign using the 305-m Arecibo telescope in 2020 January and March when the observatory was temporarily closed during the intense earthquakes and the initial outbreak of the COVID-19 pandemic, respectively. The primary objective of the survey was to search for fast radio transients, including fast radio bursts (FRBs) and rotating radio transients (RRATs). We used the seven-beam ALFA receiver to observe different sections of the sky within the declination region similar to(10 degrees-20 degrees) on 23 nights and collected 160 h of data in total. We searched our data for single-pulse transients, of covering up to a maximum dispersion measure of 11 000 pc cm(-3) at which the dispersion delay across the entire bandwidth is equal to the 13-s transit length of our observations. The analysis produced more than 18 million candidates. Machine learning techniques sorted the radio frequency interference and possibly astrophysical candidates, allowing us to visually inspect and confirm the candidate transients. We found no evidence for new astrophysical transients in our data. We also searched for emission from repeated transient signals, but found no evidence for such sources. We detected single pulses from two known pulsars in our observations and their measured flux densities are consistent with the expected values. Based on our observations and sensitivity, we estimated the upper limit for the FRB rate to be <2.8 x 10(5) sky(-1) d(-1) above a fluence of 0.16 Jy ms at 1.4 GHz, which is consistent with the rates from other telescopes and surveys.
ABSTRACT
Background: Previous research reported the effectiveness of a curriculum-based self-care intervention for students administered in the context of a course on behavior change. Purpose: The study evaluated the effectiveness of the self-care intervention for learners in a publicly available massive open online course (MOOC), who completed the course during the COVID-19 pandemic. Methods: Participants were 216 learners enrolled in Coursera's Health Behavior Change-From Evidence to Action in March 2020 - January 2021. The intervention consisted of behavior change assignments designed to increase health-promoting behaviors within three domains (nutrition, physical activity, and mental health). Course assignments were to apply behavioral principles to modify health behaviors. Outcomes included measures of physical wellbeing, depression, anxiety, perceived stress, and self-efficacy. Results: Health promotion behaviors and measures of physical and mental health showed significant improvements over the course of the semester. Discussion: The study provides support for the effectiveness of a brief self-care intervention for learners in a publicly available MOOC. Translation to Health Education Practice: This publicly available intervention can support learner well-being in a variety of academic programs, community, or workplace settings.