42 research outputs found

    The application of passive sampler (DGT) technology for improved understanding of metal behaviour at a marine disposal site

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    Metal behaviour and availability at a contaminated dredge material disposal site within UK waters has been investigated using Diffusive Gradient in Thin films (DGT) passive sampling technology. Three stations representing contrasting history and presence of maintenance dredge disposal, including a control station outside the disposal site, have been studied and depth profiles of fluxes of different metals (Fe, Mn, Pb, Cu, Cd, Cr, Ni, Zn) to the binding gel (Chelex 100) have been derived. Higher flux rates and shallower mobilisation of metals (Mn and Fe) to the binding gel were observed at the disposal stations compared to the control station. Here we describe metal mobilization at different depths, linking the remobilization of Fe2+ and Mn2+ to the sediment (re)supply of other heavy metals of interest with a focus on Cd, Ni and Pb and as they are on the Water Framework Directive (WFD) list of priority substances and OSPAR list of priority pollutants. Results showed that Cd, Pb and Ni exhibited signs of resupply at the sediment-water interface (SWI). There was a potential increased mobilisation and source to the water column of Pb and Ni at the disposal site stations, but there was no Cd source, despite higher total loadings. This information has the potential to improve our current understanding of metal cycles at disposal sites. This work can be used as an indication of likely metal bioavailability and also assist in determining whether the sites act as sources or sinks of heavy metals. This information could assist disposal site monitoring and dredge material licensing

    Benthic nitrogen cycling in the North Sea

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    We present new data on the rates of sedimentary denitrification and its component processes (canonical denitrification, anammox and dissimilatory nitrate reduction to ammonium) for intertidal and subtidal sites in the North Sea using nitrogen isotope addition methods. We find overall average denitrification rates of 6.3 (range 0.4-10.6) ”mol m-2h-1, similar to those previously reported for this region and other temperate shelf environments. We find canonical denitrification to be the dominant (>90%) process of the three. At the subtidal sites, most of the denitrification is supported by nitrate generated within the sediments, while at the intertidal site the main source is from the water column. We go on to consider the impact of these rates on nitrogen cycling within the North Sea region and compare the sediment core incubation rate results to estimates derived from modelling approaches. Model rates are somewhat higher than those directly measured and we consider possible reasons for this

    Children’s views and experiences of treatment adherence and parent/child co-management in eczema : a qualitative study

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    Eczema affects one in five children and can have a substantial impact on quality of life. This qualitative study aimed to explore children’s views and experiences of eczema and what may affect treatment adherence from their perspective. We conducted semi-structured, face-to-face interviews with children with eczema aged 6–12 years from March to July 2018. Interviews were transcribed verbatim and analysed using inductive thematic analysis. We found that children do not typically view eczema as a long-term condition, and topical treatments (predominately emollients) were seen to provide effective symptom relief. Uncertainty around co-managing at home was expressed as children typically felt that parental reminders and assistance with applying different types of topical treatments were still needed. For some children, eczema can be difficult to manage at school due to a lack of convenient access and appropriate spaces to apply creams and psychosocial consequences such as attracting unwanted attention from peers and feeling self-conscious. Treatment adherence could be supported by reinforcing that eczema is a long-term episodic condition, providing clear information about regular emollient use, practical advice such as setting reminders to support co-management at home, and working with schools to facilitate topical treatment use when necessary

    Views and experiences of managing eczema:systematic review and thematic synthesis of qualitative studies*

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    Background: The number of qualitative studies on eczema has increased rapidly in recent years. Systematically reviewing these can provide greater understandings of people’s perceptions of eczema and eczema treatments. Objectives: We sought to systematically review and thematically synthesize qualitative studies exploring views and experiences of people with eczema and parents/carers of children with eczema. Methods: We searched MEDLINE, EMBASE, PsycINFO and CINAHL from the earliest date available to February 2019. We selected papers focusing on views and experiences of eczema and eczema treatments, and barriers/facilitators to eczema self-management. We excluded papers focusing on health service provision models or health professionals’ views. Results: We synthesized 39 papers (reporting 32 studies) from 13 countries. We developed four analytical themes: (1) Eczema not viewed as a long-term condition; (2) Significant psychosocial impact not acknowledged by others; (3) Hesitancy (patient/carer uncertainty) about eczema treatments; and (4) Insufficient information and advice. Our findings suggest that people with eczema and their carers experience frustration at having to manage a condition that is often seen by others as mundane but has significant psychosocial impact and is difficult to manage due to concerns about, and burden of, treatment. This frustration can be exacerbated by experiences of conflicting and/or insufficient information and advice from health professionals, family and others. Conclusions: Effective self-management of eczema could be supported by addressing beliefs and concerns about treatments; seeking positive ways to promote a ‘control not cure’ message; acknowledging psychosocial impacts of eczema and treatment burden; and providing clear consistent advice or signposting towards reliable information.</p

    Antibiotic Review Kit for Hospitals (ARK-Hospital): study protocol for a stepped-wedge cluster-randomised controlled trial.

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    BACKGROUND: To ensure patients continue to get early access to antibiotics at admission, while also safely reducing antibiotic use in hospitals, one needs to target the continued need for antibiotics as more diagnostic information becomes available. UK Department of Health guidance promotes an initiative called 'Start Smart then Focus': early effective antibiotics followed by active 'review and revision' 24-72 h later. However in 2017, < 10% of antibiotic prescriptions were discontinued at review, despite studies suggesting that 20-30% of prescriptions could be stopped safely. METHODS/DESIGN: Antibiotic Review Kit for Hospitals (ARK-Hospital) is a complex 'review and revise' behavioural intervention targeting healthcare professionals involved in antibiotic prescribing or administration in inpatients admitted to acute/general medicine (the largest consumers of non-prophylactic antibiotics in hospitals). The primary study objective is to evaluate whether ARK-Hospital can safely reduce the total antibiotic burden in acute/general medical inpatients by at least 15%. The primary hypotheses are therefore that the introduction of the behavioural intervention will be non-inferior in terms of 30-day mortality post-admission (relative margin 5%) for an acute/general medical inpatient, and superior in terms of defined daily doses of antibiotics per acute/general medical admission (co-primary outcomes). The unit of observation is a hospital organisation, a single hospital or group of hospitals organised with one executive board and governance framework (National Health Service trusts in England; health boards in Northern Ireland, Wales and Scotland). The study comprises a feasibility study in one organisation (phase I), an internal pilot trial in three organisations (phase II) and a cluster (organisation)-randomised stepped-wedge trial (phase III) targeting a minimum of 36 organisations in total. Randomisation will occur over 18 months from November 2017 with a further 12 months follow-up to assess sustainability. The behavioural intervention will be delivered to healthcare professionals involved in antibiotic prescribing or administration in adult inpatients admitted to acute/general medicine. Outcomes will be assessed in adult inpatients admitted to acute/general medicine, collected through routine electronic health records in all patients. DISCUSSION: ARK-Hospital aims to provide a feasible, sustainable and generalisable mechanism for increasing antibiotic stopping in patients who no longer need to receive them at 'review and revise'. TRIAL REGISTRATION: ISRCTN Current Controlled Trials, ISRCTN12674243 . Registered on 10 April 2017

    Benthic pH gradients across a range of shelf sea sediment types linked to sediment characteristics and seasonal variability

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    This study used microelectrodes to record pH profiles in fresh shelf sea sediment cores collected across a range of different sediment types within the Celtic Sea. Spatial and temporal variability was captured during repeated measurements in 2014 and 2015. Concurrently recorded oxygen microelectrode profiles and other sedimentary parameters provide a detailed context for interpretation of the pH data. Clear differences in profiles were observed between sediment type, location and season. Notably, very steep pH gradients exist within the surface sediments (10–20 mm), where decreases greater than 0.5 pH units were observed. Steep gradients were particularly apparent in fine cohesive sediments, less so in permeable sandier matrices. We hypothesise that the gradients are likely caused by aerobic organic matter respiration close to the sediment–water interface or oxidation of reduced species at the base of the oxic zone (NH4+, Mn2+, Fe2+, S−). Statistical analysis suggests the variability in the depth of the pH minima is controlled spatially by the oxygen penetration depth, and seasonally by the input and remineralisation of deposited organic phytodetritus. Below the pH minima the observed pH remained consistently low to maximum electrode penetration (ca. 60 mm), indicating an absence of sub-oxic processes generating H+ or balanced removal processes within this layer. Thus, a climatology of sediment surface porewater pH is provided against which to examine biogeochemical processes. This enhances our understanding of benthic pH processes, particularly in the context of human impacts, seabed integrity, and future climate changes, providing vital information for modelling benthic response under future climate scenarios

    Seasonality and spatial heterogeneity of the surface ocean carbonate system in the northwest European continental shelf

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    In 2014–5 the UK NERC sponsored an 18 month long Shelf Sea Biogeochemistry research programme which collected over 1500 nutrient and carbonate system samples across the NW European Continental shelf, one of the largest continental shelves on the planet. This involved the cooperation of 10 different Institutes and Universities, using 6 different vessels. Additional carbon dioxide (CO2) data were obtained from the underway systems on three of the research vessels. Here, we present and discuss these data across 9 ecohydrodynamic regions, adapted from those used by the EU Marine Strategy Framework Directive (MSFD). We observed strong seasonal and regional variability in carbonate chemistry around the shelf in relation to nutrient biogeochemistry. Whilst salinity increased (and alkalinity decreased) out from the near-shore coastal waters offshore throughout the year nutrient concentrations varied with season. Spatial and seasonal variations in the ratio of DIC to nitrate concentration were seen that could impact carbon cycling. A decrease in nutrient concentrations and a pronounced under-saturation of surface pCO2 was evident in the spring in most regions, especially in the Celtic Sea. This decrease was less pronounced in Liverpool Bay and to the North of Scotland, where nutrient concentrations remained measurable throughout the year. The near-shore and relatively shallow ecosystems such as the eastern English Channel and southern North Sea were associated with a thermally driven increase in pCO2 to above atmospheric levels in summer and an associated decrease in pH. Non-thermal processes (such as mixing and the remineralisation of organic material) dominated in winter in most regions but especially in the northwest of Scotland and in Liverpool Bay. The large database collected will improve understanding of carbonate chemistry over the North-Western European Shelf in relation to nutrient biogeochemistry, particularly in the context of climate change and ocean acidification

    Understanding the retinal basis of vision across species

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    The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision

    Oxygen dynamics in shelf seas sediments incorporating seasonal variability

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    Shelf sediments play a vital role in global biogeochemical cycling and are particularly important areas of oxygen consumption and carbon mineralisation. Total benthic oxygen uptake, the sum of diffusive and faunal mediated uptake, is a robust proxy to quantify carbon mineralisation. However, oxygen uptake rates are dynamic, due to the diagenetic processes within the sediment, and can be spatially and temporally variable. Four benthic sites in the Celtic Sea, encompassing gradients of cohesive to permeable sediments, were sampled over four cruises to capture seasonal and spatial changes in oxygen dynamics. Total oxygen uptake (TOU) rates were measured through a suite of incubation experiments and oxygen microelectrode profiles were taken across all four benthic sites to provide the oxygen penetration depth and diffusive oxygen uptake (DOU) rates. The difference between TOU and DOU allowed for quantification of the fauna mediated oxygen uptake and diffusive uptake. High resolution measurements showed clear seasonal and spatial trends, with higher oxygen uptake rates measured in cohesive sediments compared to the permeable sediment. The significant differences in oxygen dynamics between the sediment types were consistent between seasons, with increasing oxygen consumption during and after the phytoplankton bloom. Carbon mineralisation in shelf sediments is strongly influenced by sediment type and seasonality
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