54 research outputs found

    Preliminary Assessment of Sponge Biodiversity on Saba Bank, Netherlands Antilles

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    Background Saba Bank Atoll, Netherlands Antilles, is one of the three largest atolls on Earth and provides habitat for an extensive coral reef community. To improve our knowledge of this vast marine resource, a survey of biodiversity at Saba Bank included a multi-disciplinary team that sampled fishes, mollusks, crustaceans, macroalgae, and sponges. Methodology/Principal Findings A single member of the dive team conducted surveys of sponge biodiversity during eight dives at six locations, at depths ranging from 15 to 30 m. This preliminary assessment documented the presence of 45 species pooled across multiple locations. Rarefaction analysis estimated that only 48 to 84% of species diversity was sampled by this limited effort, clearly indicating a need for additional surveys. An analysis of historical collections from Saba and Saba Bank revealed an additional 36 species, yielding a total of 81 sponge species recorded from this area. Conclusions/Significance This observed species composition is similar to that found on widespread Caribbean reefs, indicating that the sponge fauna of Saba Bank is broadly representative of the Caribbean as a whole. A robust population of the giant barrel sponge, Xestospongia muta, appeared healthy with none of the signs of disease or bleaching reported from other Caribbean reefs; however, more recent reports of anchor chain damage to these sponges suggests that human activities can have dramatic impacts on these communities. Opportunities to protect this extremely large habitat should be pursued, as Saba Bank may serve as a significant reservoir of sponge species diversity

    Ten Myths around Open Scholarly Publishing

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    The changing world of scholarly communication and the emergence of ‘Open Science’ or ‘Open Research’ has brought to light a number of controversial and hotly-debated topics. Yet, evidence-based rational debate is regularly drowned out by misinformed or exaggerated rhetoric, which does not benefit the evolving system of scholarly communication. The aim of this article is to provide a baseline evidence framework for ten of the most contested topics, in order to help frame and move forward discussions, practices and policies. We address preprints and scooping, the practice of copyright transfer, the function of peer review, and the legitimacy of ‘global’ databases. The presented facts and data will be a powerful tool against misinformation across wider academic research, policy and practice, and may be used to inform changes within the rapidly evolving scholarly publishing system

    Ten Hot Topics around Scholarly Publishing

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    The changing world of scholarly communication and the emergence of a new wave of 'Open Science' or 'Open Research' has brought to light a number of controversial and hotly-debated topics. Yet, evidence-based rational debate is regularly drowned out by misinformed or exaggerated rhetoric, which does not benefit the evolving system of scholarly communication. The aim of this article is to provide a baseline evidence framework for ten of the most contested topics, in order to help frame and move forward discussions, practices and policies. We address issues around preprints and scooping, the practice of copyright transfer, the function of peer review, predatory publishers, and the legitimacy of 'global' databases. The presented facts, arguments and data will be a powerful tool against misinformation across wider academic research, policy and practice, and may be used to inform changes within the rapidly evolving scholarly publishing system

    Water and nitrate exchange between a managed river and a peri-urban floodplain aquifer: quantification and management implications

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    The management of rivers for navigation, hydropower and flood risk reduction involves the installation of in‐channel structures. These influence river levels and can affect groundwater flow within hydraulically‐connected riparian floodplain aquifers. A comprehensively monitored, peri‐urban, lowland river floodplain in the southern United Kingdom was used to explore these dependencies and to examine the implications for the flux exchange of water and nitrate between the river and the floodplain alluvial aquifer. The study demonstrated that rivers maintained at high levels by management structures, result in raised groundwater levels in the adjacent aquifer and complex groundwater flow patterns. Engineered river management structures were shown to promote flow from river to aquifer through the river bed but the majority of the associated nitrate was removed in the hyporheic zone. High‐ nitrate groundwater recharge to the alluvial aquifer also occurred through overbank flood flows. Across the floodplain, substantial denitrification occurred due to anaerobic conditions resulting from carbon‐rich sediments and the shallow water table, the latter linked to the river management structures. An upper limit on the total annual mass of nitrate removed from river water entering the floodplain aquifer was estimated for the study site (2.9 x 104 kg), which was three orders of magnitude lower than the estimate of annual in‐channel nitrate flux (1.8 x 107 kg). However, this capacity of lowland floodplains to reduce groundwater nitrate concentrations has local benefits, for example for private and public water supplies sourced from alluvial aquifers. The insights from the study also have relevance for those considering schemes that include the installation, removal or redesign of river management structures, as the resultant change in groundwater levels may have consequences for floodplain meadows and the nutrient status of the aquatic system

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Determination of the strong coupling constant αs from transverse energy–energy correlations in multijet events at s√=8 TeV using the ATLAS detector

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    Measurements of transverse energy–energy correlations and their associated asymmetries in multi-jet events using the ATLAS detector at the LHC are presented. The data used correspond to s√=8 TeV proton–proton collisions with an integrated luminosity of 20.2 fb−1 . The results are presented in bins of the scalar sum of the transverse momenta of the two leading jets, unfolded to the particle level and compared to the predictions from Monte Carlo simulations. A comparison with next-to-leading-order perturbative QCD is also performed, showing excellent agreement within the uncertainties. From this comparison, the value of the strong coupling constant is extracted for different energy regimes, thus testing the running of αs(μ) predicted in QCD up to scales over 1 TeV . A global fit to the transverse energy–energy correlation distributions yields αs(mZ)=0.1162±0.0011(exp.) +0.0084−0.0070(theo.) , while a global fit to the asymmetry distributions yields a value of αs(mZ)=0.1196±0.0013(exp.) +0.0075−0.0045(theo.)

    Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

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    Background: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Methods: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. Findings: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96–1·28). Interpretation: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. Funding: National Institute for Health Research Health Services and Delivery Research Programme

    Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

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    BACKGROUND: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. METHODS: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. FINDINGS: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96-1·28). INTERPRETATION: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. FUNDING: National Institute for Health Research Health Services and Delivery Research Programme

    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

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