66 research outputs found

    Dressings and securements for the prevention of peripheral intravenous catheter failure in adults (SAVE): a pragmatic, randomised controlled, superiority trial

    Get PDF
    Background: Two billion peripheral intravenous catheters (PIVCs) are used globally each year, but optimal dressing and securement methods are not well established. We aimed to compare the efficacy and costs of three alternative approaches to standard non-bordered polyurethane dressings. Methods: We did a pragmatic, randomised controlled, parallel-group superiority trial at two hospitals in Queensland, Australia. Eligible patients were aged 18 years or older and required PIVC insertion for clinical treatment, which was expected to be required for longer than 24 h. Patients were randomly assigned (1:1:1:1) via a centralised web-based randomisation service using random block sizes, stratified by hospital, to receive tissue adhesive with polyurethane dressing, bordered polyurethane dressing, a securement device with polyurethane dressing, or polyurethane dressing (control). Randomisation was concealed before allocation. Patients, clinicians, and research staff were not masked because of the nature of the intervention, but infections were adjudicated by a physician who was masked to treatment allocation. The primary outcome was all-cause PIVC failure (as a composite of complete dislodgement, occlusion, phlebitis, and infection [primary bloodstream infection or local infection]). Analysis was by modified intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12611000769987. Findings: Between March 18, 2013, and Sept 9, 2014, we randomly assigned 1807 patients to receive tissue adhesive with polyurethane (n=446), bordered polyurethane (n=454), securement device with polyurethane (n=453), or polyurethane (n=454); 1697 patients comprised the modified intention-to-treat population. 163 (38%) of 427 patients in the tissue adhesive with polyurethane group (absolute risk difference −4·5% [95% CI −11·1 to 2·1%], p=0·19), 169 (40%) of 423 of patients in the bordered polyurethane group (–2·7% [–9·3 to 3·9%] p=0·44), 176 (41%) of 425 patients in the securement device with poplyurethane group (–1·2% [–7·9% to 5·4%], p=0·73), and 180 (43%) of 422 patients in the polyurethane group had PIVC failure. 17 patients in the tissue adhesive with polyurethane group, two patients in the bordered polyurethane group, eight patients in the securement device with polyurethane group, and seven patients in the polyurethane group had skin adverse events. Total costs of the trial interventions did not differ significantly between groups. Interpretation: Current dressing and securement methods are commonly associated with PIVC failure and poor durability, with simultaneous use of multiple products commonly required. Cost is currently the main factor that determines product choice. Innovations to achieve effective, durable dressings and securements, and randomised controlled trials assessing their effectiveness are urgently needed

    The wide-field, multiplexed, spectroscopic facility WEAVE : survey design, overview, and simulated implementation

    Get PDF
    Funding for the WEAVE facility has been provided by UKRI STFC, the University of Oxford, NOVA, NWO, Instituto de AstrofĂ­sica de Canarias (IAC), the Isaac Newton Group partners (STFC, NWO, and Spain, led by the IAC), INAF, CNRS-INSU, the Observatoire de Paris, RĂ©gion Île-de-France, CONCYT through INAOE, Konkoly Observatory (CSFK), Max-Planck-Institut fĂŒr Astronomie (MPIA Heidelberg), Lund University, the Leibniz Institute for Astrophysics Potsdam (AIP), the Swedish Research Council, the European Commission, and the University of Pennsylvania.WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366-959 nm at R ∌ 5000, or two shorter ranges at R ∌ 20,000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for ∌ 3 million stars and detailed abundances for ∌ 1.5 million brighter field and open-cluster stars; (ii) survey ∌ 0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey  ∌ 400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z 1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z > 2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.PostprintPeer reviewe

    The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

    Full text link
    WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366−-959\,nm at R∌5000R\sim5000, or two shorter ranges at R∌20 000R\sim20\,000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for ∌\sim3 million stars and detailed abundances for ∌1.5\sim1.5 million brighter field and open-cluster stars; (ii) survey ∌0.4\sim0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey ∌400\sim400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z<0.5z<0.5 cluster galaxies; (vi) survey stellar populations and kinematics in ∌25 000\sim25\,000 field galaxies at 0.3â‰Čzâ‰Č0.70.3\lesssim z \lesssim 0.7; (vii) study the cosmic evolution of accretion and star formation using >1>1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z>2z>2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.Comment: 41 pages, 27 figures, accepted for publication by MNRA

    TRY plant trait database – enhanced coverage and open access

    Get PDF
    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

    Get PDF
    WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366−959\,nm at R∌5000, or two shorter ranges at R∌20000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for ∌3 million stars and detailed abundances for ∌1.5 million brighter field and open-cluster stars; (ii) survey ∌0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey ∌400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z>2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator

    Etude des émissions de monoxyde d'azote (NO), observées en ultraviolet par SPICAV/Venus Express, en mode d'occultation stellaire

    No full text
    NO airglow is observable on each terrestrial planets surrounded by an atmosphere. On Venus, this emission have been identified in 1979. It is classicaly observed in ultraviolet, between 180 and 300 nm, but it is possible to detect it in infrared, between 1.2 and 1.3 ÎŒm too. NO nightglow is du to radiative recombinaison process occuring on the night side of the planet. Venus' atmosphere is essentially composed of CO2 and N2 and on the day side, solar radiations break this molecules and make the N and O atoms free. In the upper atmosphere, above 100 km, zonal winds transport these atoms to the night side where they recombine to form NO and emit an ultraviolet radiation. NO nightglow is thus a good tracer of this sub-solar/anti-solar circulation. The Venus Express mission, currently in orbit around Venus, possess the SPICAV instrument onboard. It is a spectrometer which is able to observe NO nightglow in ultraviolet. This thesis work is based on SPICAV observations realised in the stellar occultation mode. This data set, on which NO nightglow appears, allows to expand the data base on airglow and allows a complementary approach to limb observations. This work consist in the establishment of two NO nightglow data's inversion methods. The first method, called forward model, is a simulation of what it should be seen with SPICAV during stellar occultation. The second method, called algorithm of inversion, is a matricial inversion of the data. Both methods reach to the characteristics of the NO layer present in the atmosphere of Venus. Our results allow to better constrain the dynamical context of the Venusian atmosphere, at altitudes above 100 km.Les Ă©missions de monoxyde d'azote (NO) sont observables sur toutes les planĂštes telluriques entourĂ©es d'une atmosphĂšre. Sur VĂ©nus, ces Ă©missions ont Ă©tĂ© identifiĂ©es en 1979. Elles sont classiquement observables dans l'ultraviolet, entre 180 et 300 nm, mais il est Ă©galement possible de les dĂ©tecter en infrarouge entre 1,2 et 1,3 ÎŒm. L'Ă©mission aĂ©ronomique du NO est due Ă  un processus de recombinaison radiative se produisant du cĂŽtĂ© nuit de la planĂšte. L'atmosphĂšre de VĂ©nus est composĂ©e essentiellement de CO2 et de N2 et cĂŽtĂ© jour, les radiations solaires cassent ces molĂ©cules et libĂšrent des atomes d'azote et d'oxygĂšne. Dans la haute atmosphĂšre, au-dessus de 100 km, les vents zonaux transportent ces atomes vers le cĂŽtĂ© nocturne oĂč ils se recombinent pour former du NO et Ă©mettent alors un rayonnement ultraviolet. L'Ă©mission aĂ©ronomique du NO est ainsi un bon traceur de cette circulation sub-solaire/anti-solaire. La mission Venus Express, actuellement en orbite autour de VĂ©nus, possĂšde Ă  son bord l'instrument SPICAV, un spectromĂštre capable d'observer les Ă©missions de NO dans l'ultraviolet. Les travaux de cette thĂšse se basent sur les observations SPICAV rĂ©alisĂ©es en mode d'occultation stellaire. Ce jeu de donnĂ©es, sur lequel les Ă©missions de NO apparaissent, permet d'agrandir la base de donnĂ©es sur cette Ă©mission aĂ©ronomique et permet une approche complĂ©mentaire des observations au limbe. Le travail a consistĂ© Ă  Ă©tablir deux mĂ©thodes d'inversion de ces Ă©missions de NO. La premiĂšre mĂ©thode, appelĂ©e modĂšle direct, est une simulation de ce que nous devons observer avec SPICAV en occultation stellaire. La seconde mĂ©thode, nommĂ©e algorithme d'inversion, est une inversion matricielle des donnĂ©es. Chaque mĂ©thode aboutit aux caractĂ©ristiques de la couche de NO prĂ©sente dans l'atmosphĂšre de VĂ©nus. Nos rĂ©sultats permettent de mieux contraindre le contexte dynamique de l'atmosphĂšre vĂ©nusienne, aux altitudes supĂ©rieures Ă  100 km

    Etude des émissions de monoxyde d'azote (NO), observées en ultraviolet par SPICAV / Venus Express, en mode d'occultation stellaire

    No full text
    Les Ă©missions de monoxyde d azote (NO) sont classiquement observables dans l ultraviolet, entre 180 et 300 nm. L Ă©mission aĂ©ronomique du NO est due Ă  un processus de recombinaison radiative se produisant du cĂŽtĂ© nuit de la planĂšte. L atmosphĂšre de VĂ©nus est composĂ©e essentiellement de CO2 et de N2 et cĂŽtĂ© jour, les radiations solaires cassent ces molĂ©cules et libĂšrent des atomes d azote et d oxygĂšne. Dans la haute atmosphĂšre, au-dessus de 100 km, les vents zonaux transportent ces atomes vers le cĂŽtĂ© nocturne oĂč ils se recombinent pour former du NO et Ă©mettent alors un rayonnement ultraviolet. L Ă©mission aĂ©ronomique du NO est ainsi un bon traceur de cette circulation sub-solaire/anti-solaire. La mission Venus Express, actuellement en orbite autour de VĂ©nus, possĂšde Ă  son bord l instrument SPICAV, un spectromĂštre capable d observer les Ă©missions de NO dans l ultraviolet. Les travaux de cette thĂšse se basent sur les observations SPICAV rĂ©alisĂ©es en mode d occultation stellaire. Ce jeu de donnĂ©es permet d agrandir la base de donnĂ©es sur cette Ă©mission aĂ©ronomique et permet une approche complĂ©mentaire des observations au limbe. Le travail a consistĂ© Ă  Ă©tablir deux mĂ©thodes d'inversion de ces Ă©missions de NO. La premiĂšre mĂ©thode, appelĂ©e modĂšle direct, est une simulation de ce que nous devons observer avec SPICAV en occultation stellaire. La seconde mĂ©thode, nommĂ©e algorithme d'inversion, est une inversion matricielle des donnĂ©es. Chaque mĂ©thode aboutit aux caractĂ©ristiques de la couche de NO prĂ©sente dans l atmosphĂšre de VĂ©nus. Nos rĂ©sultats permettent de mieux contraindre le contexte dynamique de l atmosphĂšre vĂ©nusienne, aux altitudes supĂ©rieures Ă  100 kmPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

    Observations Of The Ultraviolet Nitric Oxide (NO) Nightglow With SPICAV On Board Venus Express During Stellar Occultations

    No full text
    International audienceUltraviolet nightglow have been detected on Venus for the first time by Barth and al., in 1968, from Mariner 5, then identified like to be nitric oxide nightglow by Feldmann and al., and by Stewart and Barth, in 1979, with Pioneer. SPICAV (SPectroscopy for the Characteristics of the Atmosphere of Venus), on board Venus Express spacecraft, currently in orbit around Venus, also see them. We descibe here a forward model allowed to reproduce this nitric oxide nightglow. It is a first approach in a better understanding of the dynamic phenomena of the venusian thermosphere. When working in the spectrometric mode with the slit, SPICAV has shown that the Venus nightglow contains essentially Lyman-a and nitric oxide (NO) emission, well studied by Gerard et al. (2008b). What we show here is that, when SPICAV is used in the stellar occultation mode (without the slit), quite often an emission is present at the limb, in addition to the stellar spectrum. A forward model of the NO emission observed without the slit, when compared to the data, confirms that indeed this limb emission is due to NO nightglow. This observing mode without the slit is 50 times more sensitive than with the slit, owing to the larger subtended FOV. Terefore, its systematic extraction from stellar occultations will extend the data base of NO emission already collected in the limb spectroscopic mode (Gerard et al., 1981 and 2008b). This emission, due to recombinaison of N and O atoms produced on the dayside of Venus, and transported to the nightside, allows to study the Solar to Anti-solar thermospheric circulation (above 100 km). The comparaison with the forward model allows to derive the emission intensity, the altitude of the layer, and its scale height. Owing to the large number of star occultations recorded, and higher sensitivity, the systematic extraction of NO emission parameters from stellar occultations will add a large number of NO observations as tracers of the venusian thermospheric circulation, giving strong contraints on the thermospheric general circulation model (TGCM)
    • 

    corecore