40 research outputs found

    The James Webb Space Telescope Mission

    Full text link
    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Search for pair production of excited top quarks in the lepton+jets final state

    Get PDF

    A geospatial analysis of two-hour surgical access to district hospitals in South Africa

    Get PDF
    CITATION: Chu, K. M., et al. 2020. A geospatial analysis of two-hour surgical access to district hospitals in South Africa. BMC Health Services Research, 20:744, doi:10.1186/s12913-020-05637-0.The original publication is available at https://bmchealthservres.biomedcentral.comBackground: In a robust health care system, at least 80% of a country’s population should be able to access a district hospital that provides surgical care within 2 hours. The objective was to identify the proportion of the population living within 2 hours of a district hospital with surgical capacity in South Africa. Methods: All government hospitals in the country were identified. Surgical district hospitals were defined as district hospitals with a surgical provider, a functional operating theatre, and the provision of at least one caesarean section annually. The proportion of the population within two-hour access was estimated using service area methods. Results: Ninety-eight percent of the population had two-hour access to any government hospital in South Africa. One hundred and thirty-eight of 240 (58%) district hospitals had surgical capacity and 86% of the population had two-hour access to these facilities. Conclusion: Improving equitable surgical access is urgently needed in sub-Saharan Africa. This study demonstrated that in South Africa, just over half of district hospitals had surgical capacity but more than 80% of the population had two-hour access to these facilities. Strengthening district hospital surgical capacity is an international mandate and needed to improve access.https://bmchealthservres.biomedcentral.com/articles/10.1186/s12913-020-05637-0Publisher's versio

    Probing solution behaviour of metallosupramolecular complexes using pyrene fluorescence

    Get PDF
    A new method for assessing the topology of metallosupramolecular assemblies using pyrene-appended ligands is reported. Two potentially tetradentate ligands containing one (L1) and two (L2) terminal pyrene moieties were synthesised and their complexes with Cu+ and Cd2+ were characterised. Photophysical measurements demonstrate that in [Cu2(L1)2]2+, [CdL1]2+ and [Cu2(L2)2]2+ the emission spectra are dominated by monomeric emission but in the cadmium complex of L2 (where the pyrene units are in close proximity) a quenching of the luminescence coupled with weak emission at 540 nm is indicative of excimer formation
    corecore