29 research outputs found

    Multi-messenger observations of a binary neutron star merger

    Get PDF
    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 global research priority agenda to advance public health responses to fatty liver disease

    Get PDF
    Background & aims An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community. Methods Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy. Results The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of ‘agree’ responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement (‘agree’ + ‘somewhat agree’); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% ‘agree’), 13 priorities had 90% combined agreement. Conclusions Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health community’s efforts to advance and accelerate responses to this widespread and fast-growing public health threat. Impact and implications An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat

    An updated checklist of Araceae, Leguminosae and Myrtaceae of the department of Boyacá, Colombia, including keys to genera and new occurrence records.

    No full text
    Baseline checklists for the Leguminosae (Fabaceae), Araceae and Myrtaceae from the Colombian department of Boyacá are available from the Catalogue of Plants and Lichens of Colombia. These lists were supplemented by thorough herbarium and literature searches by a collaborative group of local and international experts, and further enhanced by local field collections. The result is authoritative taxonomic checklists for the three families including data regarding habit, plant uses and species conservation risk assessments for a subset of species. The checklists have notably increased the number of species reported from Boyacá and provide reliable, taxonomically up-to-date inventories for those families. Checklists are based on specimens vouchered in local herbaria and revised specimen metadata is lodged in the Colombian biological information platform CEIBA. The initiative demonstrates how relatively low levels of funding allow taxonomic experts working in networks to rapidly improve the taxonomic understanding of angiosperm species diversity in megadiverse countries like Colombia

    The gendered violence of development: imaginative geographies of exclusion in the imposition of neo-liberal capitalism

    No full text
    In this article I consider how gendered hierarchies are constitutive of neo-liberal development and the violence attendant upon it. Building on Arturo Escobar's observation that violence is constitutive of development, I explore how the violent imposition of neo-liberal development is legitimised through the inscription of gendered imaginative geographies, which define ‘savage’ spaces of exclusion in need of ‘civilising’ development interventions. Drawing on the example of contemporary Colombia, I trace how the development discourse produces space in this way by normalising certain identities and political rationalities—those associated with competition and rational economic behaviour—while representing others as errant, as hyper-masculine subjects prone to violence or ‘pre-rational’ feminised subjects
    corecore