Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd

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

Superusers’ Engagement in Asthma Online Communities: Asynchronous Web-Based Interview Study

Background:Superusers, defined as the 1% of users who write a large number of posts, play critical roles in online health communities (OHCs), catalysing engagement and influencing other users’ self-care. Their unique online behavior is key to sustaining activity in OHCs and making them flourish. Our previous work showed the presence of 20-30 superusers active on a weekly basis among 3,345 users in the nation-wide Asthma UK OHC and that the community would disintegrate if superusers were removed. Recruiting to research these highly skilled individuals can be challenging and little is known about superusers. Objective:To explore superusers’ motivation to actively engage in OHCs, the difficulties they may face, and their interactions with healthcare professionals (HCPs). Methods:Asynchronous online structured interview study. Questions were developed based on OHCs literature, our previous studies and face-to-face discussions with superusers. Superusers of the Asthma UK OHC and Facebook groups were recruited through Asthma UK staff to pilot and subsequently complete the questionnaire. Open-ended questions were analyzed using qualitative content analysis. Results:17 superusers were recruited (15 patients with asthma, 2 carers), 15/17 were female; age range: 18-75y, were active in OHCs over 1-6 years, spending between 1-20 hours/week (median 2 hours) reading and 1-3 hours/week (median 0.75 hours) writing posts. 10/17 users participated in two or more OHCs. Superusers’ participation in OHCs was prompted by curiosity about asthma and its medical treatment and by availability of spare time when they were off-work due to asthma exacerbations or retired. Their engagement increased over time as participants furthered their familiarity with the OHCs, their interest in community members, and their knowledge of asthma and its self-management. Superusers were altruistic: financial or social recognition of superuser role was not important; their reward came from helping, and interacting with, others. According to the replies provided, they showed careful judgement to distinguish what can be dealt with through peer support/advice and what needs input from HCPs. Difficulties were encountered when dealing with: misunderstandings about asthma and its treatment; patients not seeking advice from HCPs when needed; “miracle cures” or dangerous ideas. 3/17 stated their HCPs were aware of their engagement with OHCs. All superusers thought HCPs should direct patients to OHCs, provided they are well-trusted and moderated. 9/17 felt HCPs themselves should take part in OHCs. Conclusions:Superusers from a UK-wide online community comprising thousands of patients with asthma and carers are altruistic, mostly female individuals who exhibit judgement about the complexity of coping with asthma and the limits of their advice. Future research should explore how to address their difficulties and unmet needs, their interactions with HCPs and the potential integration of OHCs in traditional healthcare. Clinical Trial: n/