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

Effectiveness of organisational infrastructures to promote evidence-based nursing practice.

BACKGROUND: Nurses and midwives form the bulk of the clinical health workforce and play a central role in all health service delivery. There is potential to improve health care quality if nurses routinely use the best available evidence in their clinical practice. Since many of the factors perceived by nurses as barriers to the implementation of evidence-based practice (EBP) lie at the organisational level, it is of interest to devise and assess the effectiveness of organisational infrastructures designed to promote EBP among nurses. OBJECTIVES: To assess the effectiveness of organisational infrastructures in promoting evidence-based nursing. SEARCH METHODS: We searched the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, LILACS, BIREME, IBECS, NHS Economic Evaluations Database, Social Science Citation Index, Science Citation Index and Conference Proceedings Citation Indexes up to 9 March 2011.We developed a new search strategy for this update as the strategy published in 2003 omitted key terms. Additional search methods included: screening reference lists of relevant studies, contacting authors of relevant papers regarding any further published or unpublished work, and searching websites of selected research groups and organisations.  SELECTION CRITERIA: We considered randomised controlled trials, controlled clinical trials, interrupted times series (ITSs) and controlled before and after studies of an entire or identified component of an organisational infrastructure intervention aimed at promoting EBP in nursing. The participants were all healthcare organisations comprising nurses, midwives and health visitors. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed risk of bias. For the ITS analysis, we reported the change in the slopes of the regression lines, and the change in the level effect of the outcome at 3, 6, 12 and 24 months follow-up. MAIN RESULTS: We included one study from the USA (re-analysed as an ITS) involving one hospital and an unknown number of nurses and patients. The study evaluated the effects of a standardised evidence-based nursing procedure on nursing care for patients at risk of developing healthcare-acquired pressure ulcers (HAPUs). If a patient's admission Braden score was below or equal to 18 (i.e. indicating a high risk of developing pressure ulcers), nurses were authorised to initiate a pressure ulcer prevention bundle (i.e. a set of evidence-based clinical interventions) without waiting for a physician order. Re-analysis of data as a time series showed that against a background trend of decreasing HAPU rates, if that trend was assumed to be real, there was no evidence of an intervention effect at three months (mean rate per quarter 0.7%; 95% confidence interval (CI) 1.7 to 3.3; P = 0.457). Given the small percentages post intervention it was not statistically possible to extrapolate effects beyond three months. AUTHORS' CONCLUSIONS: Despite extensive searching of published and unpublished research we identified only one low-quality study; we excluded many studies due to non-eligible study design. If policy-makers and healthcare organisations wish to promote evidence-based nursing successfully at an organisational level, they must ensure the funding and conduct of well-designed studies to generate evidence to guide policy