Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

A Pilot Randomized Controlled Trial of a Mindfulness Program for Filipino Children

Objectives This study examines the feasibility and acceptability of a local adaptation of a mindfulness-based cognitive therapy (MBCT) program for Filipino school children, called Kamalayan, that was facilitated by trained public school teachers. It also presents preliminary evidence of program effects on the children’s depressive and anxiety symptoms and difficulties in emotion regulation. Methods We utilized a randomized controlled design with an active control condition. Filipino elementary and high school students aged 9 to 16 years old from low-resource schools were randomly assigned to the Kamalayan (n = 87) or the active control Handicrafts condition (n = 99). Changes in outcomes from baseline, immediate post-intervention, and 2-month follow-up were assessed using multilevel modeling. Results Participation in the Kamalayan program did not affect depression, anxiety, or emotion regulation. Impulse control difficulties increased for the Handicrafts group across post-intervention and follow-up but remained stable for Kamalayan participants. Depressive symptoms decreased over time for the Handicrafts group but remained stable for the Kamalayan condition. Implementation issues qualify the absence of program effects, such as the impracticability of delivering after-school sessions in the public school context, program content that may be discordant with cognitive-developmental and cultural considerations, and the inadequacy of the personal mindfulness practice of the paraprofessional facilitators. Conclusions The findings reaffirm the importance of using active control groups and considering the capacities of facilitators in evaluating the effects of mindfulness-based interventions. Testing mindfulness-based interventions in low-resource, non-Western school settings require deeper contextual adaptation and facilitator preparation