39 research outputs found

    Water Framework Directive Intercalibration Technical Report: Lake phytobenthos ecological assessment methods

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    The European Water Framework Directive (WFD) requires the national classifications of good ecological status to be harmonised through an intercalibration exercise. In this exercise, significant differences in status classification among Member States are harmonized by comparing and, if necessary, adjusting the good status boundaries of the national assessment methods. Intercalibration is performed for rivers, lakes, coastal and transitional waters, focusing on selected types of water bodies (intercalibration types), anthropogenic pressures and Biological Quality Elements. Intercalibration exercises were carried out in Geographical Intercalibration Groups - larger geographical units including Member States with similar water body types - and followed the procedure described in the WFD Common Implementation Strategy Guidance document on the intercalibration process (European Commission, 2011). In a first phase, the intercalibration exercise started in 2003 and extended until 2008. The results from this exercise were agreed on by Member States and then published in a Commission Decision, consequently becoming legally binding (EC, 2008). A second intercalibration phase extended from 2009 to 2012, and the results from this exercise were agreed on by Member States and laid down in a new Commission Decision (EC, 2013) repealing the previous decision. Member States should apply the results of the intercalibration exercise to their national classification systems in order to set the boundaries between high and good status and between good and moderate status for all their national types. Annex 1 to this Decision sets out the results of the intercalibration exercise for which intercalibration is successfully achieved, within the limits of what is technically feasible at this point in time. The Technical report on the Water Framework Directive intercalibration describes in detail how the intercalibration exercise has been carried out for the water categories and biological quality elements included in that Annex. The Technical report is organized in volumes according to the water category (rivers, lakes, coastal and transitional waters), Biological Quality Element and Geographical Intercalibration group. This volume addresses the intercalibration of the cross-GIG phytobenthos ecological assessment methods

    No Change in Executive Function or Stress Hormones Following a Bout of Moderate Treadmill Exercise in Preadolescent Children

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    International Journal of Exercise Science 13(5): 1650-1666, 2020. Several studies suggest that acute bouts of exercise improve executive function in preadolescent children. However, the mechanisms underlying these effects are not completely understood. Specifically, no studies have examined the relationship between the stress hormone response to exercise and improvements in executive function in preadolescent children. The purpose of this study was to examine the effects of a bout of moderate intensity exercise versus rest on working memory (List Sorting Working Memory Task) and selective inhibition/attention (Eriksen flanker task) in preadolescent children, as well as to investigate whether changes in stress hormones (salivary cortisol and alpha-amylase) could explain any differences in performance on these tasks. Twenty-four children completed both a 30-minute moderate intensity bout of treadmill walking and seated rest in a laboratory setting. Tests of executive function and salivary stress hormone analyses were completed before and after each condition. 2x2 Repeated Measures ANOVAs were used to test the effects of time, condition, and time*condition on all executive function and hormonal outcomes. Linear regression models were used to determine if changes in executive function measures were related to changes in stress hormones in the exercise condition. Likely due to methodological limitations, there were no effects of time, condition, nor an interactive effect on working memory, selective inhibition, salivary cortisol, or salivary alpha-amylase. However, there was a trend observed, where the magnitude of the increase in salivary alpha-amylase levels in the exercise condition marginally predicted the improvement in reaction time on the Eriksen flanker task. This suggests that exercise-induced changes in alpha-amylase may underlie improvements in executive function and highlights the need for additional research to more fully understand these relationships in preadolescent children

    Assessment of ecological status in UK lakes using benthic diatoms

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    The European Union’s Water Framework Directive (WFD) requires that all water bodies in Europe achieve good ecological status (GES) by 2015. We developed an ecological classification tool for UK lakes based on benthic diatoms, a key component of the biological-quality element macrophytes and phytobenthos. A database of 1079 epilithic and epiphytic diatom samples and matching environmental data was assembled from 228 UK lakes. The data set was divided into 3 lake types: low, medium, and high alkalinity. A lake trophic diatom index (LTDI) was developed based on modification of the trophic diatom index (TDI) for rivers, and ecological quality ratios (EQRs) were generated for each lake type. The high/good status boundary was defined as the 25th percentile of EQRs of all reference sites (identified based on independent sedimentary-diatom-assemblage data or catchment point-source and landuse data), whereas the good/moderate boundary was set at the point at which nutrient-sensitive and nutrient-tolerant taxa were present in equal relative abundance. The moderate/poor and poor/bad boundaries were defined by equal division of the remaining EQR gradient. Samples from reference sites were used to predict the expected LTDI value for each sample, and these values were compared with the classifications derived from the LTDI. For lakes identified as reference sites, 68% were classified as having high status and 32% as having good. The model predicted 81% of nonreference lakes to have good or worse status. The model was applied to 17 English lakes (10 low- and 7 medium-alkalinity) for which classification based on other WFD tools was available. The classifications based on LTDI gave the same status (within 1 class) as other biological elements for 11 of the 17 lakes (65%). Thus, the LTDI gives a reliable assessment of the condition of the littoral biofilm and is a key component of a WFD-compliant tool kit for classifying UK standing waters

    Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

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    Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

    Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

    Assessment of ecological status in UK lakes using diatoms - Draft

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    1. The European Union’s Water Framework Directive requires all water bodies to achieve ‘good ecological status’ by 2015 and this chapter describes an ecological classification tool for lakes based on diatoms, a key component of the biological quality element ‘macrophytes and phytobenthos’. 2. A database of benthic diatom samples collected since 2003, specifically for development of the tool, was assembled. In total 1079 samples from 228 lakes were included in the database with matching environmental data. The dataset was divided into three lake types - low, medium and high alkalinity. 3. ‘Reference sites’, relatively unimpacted by human activity, were selected from this database based on a range of criteria including evidence of degree of change based on palaeolimnological data, and were used to develop a type-specific reference typology. 4. A lake trophic diatom index (LTDI) was developed and ecological quality ratios (EQRs) were generated for each lake type that are ≥1, where the diatom assemblage showed no impact, to (theoretically) 0, when the diatom assemblage was indicative of major anthropogenic activities. 5. The boundary between ‘high’ and ‘good’ status was defined as the 25th percentile of EQRs of all reference sites. The boundary between ‘good’ and ‘moderate’ status was set at the point at which nutrient-sensitive and nutrient-tolerant taxa were present in equal relative abundance. The ‘moderate’/’poor’ and ‘poor’/’bad’ boundaries were then defined by equal division of the remaining EQR gradient. 6. The reference data were employed to predict the ‘expected’ class at each site and these were compared with the classifications derived from the tool. For lakes identified as reference sites, 68% were classified as high with the remainder classified as good. For non-reference lakes the model predicted the majority of sites to be good or worse. The model appears to perform well. 7. The performance of the model was further tested by application to a set of 17 Cumbrian lakes for which classification based on a range of other tools was available. There was a tendency for the diatom tool classifications to be more relaxed than those using other tools with 76% of lakes being placed in a higher status class than that indicated by the entire suite of biological metrics. The findings suggest that the reference community in low alkalinity lakes might be 'buffered' against change as the dominant taxa appear to be relatively tolerant to mild enrichment. 8. In an attempt to improve the predictions for low alkalinity lakes the response of surface sediment diatom assemblages along the nutrient gradient was explored, as these potentially contain a more diverse benthic diatom assemblage as well as planktonic taxa. However, a set of weighted averaging transfer functions offered no improvement over the diatom tool based on epilithic and epiphytic assemblages. 9. In conclusion, for low alkalinity lakes in particular, DALES is more relaxed than other UK tools. However, DALES gives an accurate assessment of the condition of the littoral biofilm and thus provides a WFD compliant tool to form part of the toolkit for classifying UK standing waters
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