33 research outputs found

    Benefits of deposition reduction for nature management; a nation-wide assessment of the relation between atmospheric deposition, ecological quality and avoidable management costs

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    Alterra was commissioned by the Dutch Ministry of Housing, Spatial Planning and the Environment (VROM) to estimate the additional costs made by nature reserve managers to mitigate the effects of atmospheric deposition. The costs of increasing deposition levels - or the benefits of reducing deposition levels - were calculated from the costs for nature management per Nature Target Type (NTT) for both the current and reduced deposition levels, which result in a similar ecological quality. For the NTTs within the clusters grassland, reed and roughland, and heathland model simulations were run using the models of the `Nature Planner`. For forests and moorland pools a different approach was used. The total amount of money that may be saved because of the reduction of deposition rates is estimated on 42 million euro per year for the period from 2000 till 2020 for the assessed NTTs. The highest savings can be made in grassland; 28 million euro. On average, over a nitrogen deposition reduction from 2312 to 1304 mol per hectare per year, a reduction of one mol per hectare per year can lead to a reduction of costs for nature management of 42 thousand euro per year for the involved NTTs nation-wide

    Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV

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    The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 degree to 58 degree. Due to the large exposure of about 150 m2 sr d, and the excellent momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in the vertical direction is achieved. The ratio of positive to negative muons is studied between 20 GeV and 500 GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003 (stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure

    Quality indicators for patients with traumatic brain injury in European intensive care units

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    Background: The aim of this study is to validate a previously published consensus-based quality indicator set for the management of patients with traumatic brain injury (TBI) at intensive care units (ICUs) in Europe and to study its potential for quality measur

    Changing care pathways and between-center practice variations in intensive care for traumatic brain injury across Europe

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    Purpose: To describe ICU stay, selected management aspects, and outcome of Intensive Care Unit (ICU) patients with traumatic brain injury (TBI) in Europe, and to quantify variation across centers. Methods: This is a prospective observational multicenter study conducted across 18 countries in Europe and Israel. Admission characteristics, clinical data, and outcome were described at patient- and center levels. Between-center variation in the total ICU population was quantified with the median odds ratio (MOR), with correction for case-mix and random variation between centers. Results: A total of 2138 patients were admitted to the ICU, with median age of 49 years; 36% of which were mild TBI (Glasgow Coma Scale; GCS 13–15). Within, 72 h 636 (30%) were discharged and 128 (6%) died. Early deaths and long-stay patients (> 72 h) had more severe injuries based on the GCS and neuroimaging characteristics, compared with short-stay patients. Long-stay patients received more monitoring and were treated at higher intensity, and experienced worse 6-month outcome compared to short-stay patients. Between-center variations were prominent in the proportion of short-stay patients (MOR = 2.3, p < 0.001), use of intracranial pressure (ICP) monitoring (MOR = 2.5, p < 0.001) and aggressive treatme

    Machine learning algorithms performed no better than regression models for prognostication in traumatic brain injury

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    Objective: We aimed to explore the added value of common machine learning (ML) algorithms for prediction of outcome for moderate and severe traumatic brain injury. Study Design and Setting: We performed logistic regression (LR), lasso regression, and ridge regression with key baseline predictors in the IMPACT-II database (15 studies, n = 11,022). ML algorithms included support vector machines, random forests, gradient boosting machines, and artificial neural networks and were trained using the same predictors. To assess generalizability of predictions, we performed internal, internal-external, and external validation on the recent CENTER-TBI study (patients with Glasgow Coma Scale <13, n = 1,554). Both calibration (calibration slope/intercept) and discrimination (area under the curve) was quantified. Results: In the IMPACT-II database, 3,332/11,022 (30%) died and 5,233(48%) had unfavorable outcome (Glasgow Outcome Scale less than 4). In the CENTER-TBI study, 348/1,554(29%) died and 651(54%) had unfavorable outcome. Discrimination and calibration varied widely between the studies and less so between the studied algorithms. The mean area under the curve was 0.82 for mortality and 0.77 for unfavorable outcomes in the CENTER-TBI study. Conclusion: ML algorithms may not outperform traditional regression approaches in a low-dimensional setting for outcome prediction after moderate or severe traumatic brain injury. Similar to regression-based prediction models, ML algorithms should be rigorously validated to ensure applicability to new populations

    Tracheal intubation in traumatic brain injury

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    Background: We aimed to study the associations between pre- and in-hospital tracheal intubation and outcomes in traumatic brain injury (TBI), and whether the association varied according to injury severity. Methods: Data from the international prospective pan-European cohort study, Collaborative European NeuroTrauma Effectiveness Research for TBI (CENTER-TBI), were used (n=4509). For prehospital intubation, we excluded self-presenters. For in-hospital intubation, patients whose tracheas were intubated on-scene were excluded. The association between intubation and outcome was analysed with ordinal regression with adjustment for the International Mission for Prognosis and Analysis of Clinical Trials in TBI variables and extracranial injury. We assessed whether the effect of intubation varied by injury severity by testing the added value of an interaction term with likelihood ratio tests. Results: In the prehospital analysis, 890/3736 (24%) patients had their tracheas intubated at scene. In the in-hospital analysis, 460/2930 (16%) patients had their tracheas intubated in the emergency department. There was no adjusted overall effect on functional outcome of prehospital intubation (odds ratio=1.01; 95% confidence interval, 0.79–1.28; P=0.96), and the adjusted overall effect of in-hospital intubation was not significant (odds ratio=0.86; 95% confidence interval, 0.65–1.13; P=0.28). However, prehospital intubation was associated with better functional outcome in patients with higher thorax and abdominal Abbreviated Injury Scale scores (P=0.009 and P=0.02, respectively), whereas in-hospital intubation was associated with better outcome in patients with lower Glasgow Coma Scale scores (P=0.01): in-hospital intubation was associated with better functional outcome in patients with Glasgow Coma Scale scores of 10 or lower. Conclusion: The benefits and harms of tracheal intubation should be carefully evaluated in patients with TBI to optimise benefit. This study suggests that extracranial injury should influence the decision in the prehospital setting, and level of consciousness in the in-hospital setting. Clinical trial registration: NCT02210221

    Informed consent procedures in patients with an acute inability to provide informed consent

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    Purpose: Enrolling traumatic brain injury (TBI) patients with an inability to provide informed consent in research is challenging. Alternatives to patient consent are not sufficiently embedded in European and national legislation, which allows procedural variation and bias. We aimed to quantify variations in informed consent policy and practice. Methods: Variation was explored in the CENTER-TBI study. Policies were reported by using a questionnaire and national legislation. Data on used informed consent procedures were available for 4498 patients from 57 centres across 17 European countries. Results: Variation in the use of informed consent procedur

    Impurity determination by thermal analysis : I. The melting curve of a gradually frozen sample

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    A temperature-heat content relation is presented for binary systems which show solid solutions. Contrary to previous equations, the present equation accounts for the very restricted rate of diffusion in the solid. The equation is based on local equilibrium during freezing and melting. The equation obtaining to the comparative method of impurity determination and applicable to a gradually frozen sample is identical to the equation previously derived on the basis of total equilibrium. The corresponding equations of the absolute method differ considerably. Experiments confirm the local equilibrium theory and show the inadequacy of the total equilibrium theory

    A new cryoscopic micro-method for the determination of molecular weights

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    A method is described for molecular weight determination based on a temperature-heat content curve About 2 mg of substance is required The method is applicable even when solute and solvent form mixed crystals. A wide variety of solvents may be used. The method may yield good results in the polymer field. The accuracy obtained is better than 1%. The new method appears to be more reliable and accurate than known cryobcopic method

    Zone melting as an aid to impurity determi nation by thermal analysis

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    The determination of the impurity content of a sample by means of the meltingcurve method (calorimetric analysis) is often seriously hampered when solid soluble contaminants are present. Solid solutions often occur in substances purified by crystallization or extraction. A simple test on mixed crystals is described. When three or more impurities are present the relations obtainable from a melting curve are insufficiently accurate for computing the unknown concentrations and distribution coefficients to an acceptable extent. Only melting curves obtained from samples containing one or two impurities permit an exact, simple interpretation. A complex of impurities may be analysed when the sample is subjected to zone melting and a set of melting curves is obtained for parts of the ingot
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