1,505 research outputs found

    Ruimtelijke dynamiek van weidevogelpopulaties in relatie tot de kwaliteit van de broedhabitat. Welke factoren beĂŻnvloeden de vestiging van weidevogels?

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    Recent onderzoek toonde aan dat percelen met een uitgestelde maaidatum geen hogere dichtheden weidevogels herbergen dan gangbaar, vroeg gemaaide percelen. Deze resultaten zijn moeilijk te verklaren aan de hand van bestaande kennis over ruimtelijke dynamiek en nestplaatskeuze van weidevogels. Deze studie heeft tot doel vast te stellen of de nestplaatsen van weidevogels ruimtelijke geassocieerd zijn met één of meerdere omgevingsvariabelen in de vestigingsfase. Voor de grutto werd daarnaast nog gekeken of de aanleg van plas-dras percelen leidt tot een verhoging van het aantal broedparen in de nabijheid van deze percelen en wat de invloedssfeer is van deze percelen (waar broeden de grutto’s die gebruik maken van een plas-dras perceel?)

    Efficacy and safety outcomes of recanalization procedures in patients with acute symptomatic pulmonary embolism: systematic review and network meta-analysis.

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    Background We aimed to review the efficacy and safety of recanalisation procedures for the treatment of PE. Methods We searched PubMed, the Cochrane Library, EMBASE, EBSCO, Web of Science and CINAHL databases from inception through 31 July 2015 and included randomised clinical trials that compared the effect of a recanalisation procedure versus each other or anticoagulant therapy in patients diagnosed with PE. We used network meta-analysis and multivariate randomeffects meta-regression to estimate pooled differences between each intervention and meta-regression to assess the association between trial characteristics and the reported effects of recanalisation procedures versus anticoagulation. Results For all-cause mortality, there were no significant differences in event rates between any of the recanalisation procedures and anticoagulant treatment (full-dose thrombolysis: OR 0.60; 95% CI0.36 to 1.01; low-dose thrombolysis: 0.47; 95%CI 0.14 to 1.59; and catheter-associated thrombolysis: 0.31; 95%CI 0.01 to 7.96). Full-dose thrombolysis increased the risk of major bleeding (2.00; 95%CI 1.06 to 3.78) compared with anticoagulation. Catheter-directed thrombolysis was associated with the lowest probability of dying (surface under the cumulative ranking curve (SUCRA), 0.67), followed by low-dose thrombolysis (SUCRA, 0.66) and full-dose thrombolysis (SUCRA, 0.55). Similarly, low-dose thrombolysis was associated with the lowest probability of major bleeding (SUCRA, 0.61), followed by catheterdirected thrombolysis (SUCRA, 0.54) and full-dose thrombolysis (SUCRA, 0.17). The results were similar in sensitivity analyses based on restricting only to studies in haemodynamically stable patients with PE. Conclusions In the treatment of PE, recanalisation procedures do not seem to offer a clear advantage compared with standard anticoagulation. Low-dose thrombolysis was associated with the lowest probability of dying and bleedingpre-print549 K

    Developing oil and gas resources in Arctic waters

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    Including debris cover effects in a distributed model of glacier ablation

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    Distributed glacier melt models generally assume that the glacier surface consists of bare exposed ice and snow. In reality, many glaciers are wholly or partially covered in layers of debris that tend to suppress ablation rates. In this paper, an existing physically based point model for the ablation of debris-covered ice is incorporated in a distributed melt model and applied to Haut Glacier d’Arolla, Switzerland, which has three large patches of debris cover on its surface. The model is based on a 10 m resolution digital elevation model (DEM) of the area; each glacier pixel in the DEM is defined as either bare or debris-covered ice, and may be covered in snow that must be melted off before ice ablation is assumed to occur. Each debris-covered pixel is assigned a debris thickness value using probability distributions based on over 1000 manual thickness measurements. Locally observed meteorological data are used to run energy balance calculations in every pixel, using an approach suitable for snow, bare ice or debris-covered ice as appropriate. The use of the debris model significantly reduces the total ablation in the debris-covered areas, however the precise reduction is sensitive to the temperature extrapolation used in the model distribution because air near the debris surface tends to be slightly warmer than over bare ice. Overall results suggest that the debris patches, which cover 10% of the glacierized area, reduce total runoff from the glacierized part of the basin by up to 7%

    Axonal abnormalities in vanishing white matter

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    ObjectiveWe aimed to study the occurrence and development of axonal pathology and the influence of astrocytes in vanishing white matter. MethodsAxons and myelin were analyzed using electron microscopy and immunohistochemistry on Eif2b4 and Eif2b5 single- and double-mutant mice and patient brain tissue. In addition, astrocyte-forebrain co-culture studies were performed. ResultsIn the corpus callosum of Eif2b5-mutant mice, myelin sheath thickness, axonal diameter, and G-ratio developed normally up to 4 months. At 7 months, however, axons had become thinner, while in control mice axonal diameters had increased further. Myelin sheath thickness remained close to normal, resulting in an abnormally low G-ratio in Eif2b5-mutant mice. In more severely affected Eif2b4-Eif2b5 double-mutants, similar abnormalities were already present at 4 months, while in milder affected Eif2b4 mutants, few abnormalities were observed at 7 months. Additionally, from 2 months onward an increased percentage of thin, unmyelinated axons and increased axonal density were present in Eif2b5-mutant mice. Co-cultures showed that Eif2b5 mutant astrocytes induced increased axonal density, also in control forebrain tissue, and that control astrocytes induced normal axonal density, also in mutant forebrain tissue. In vanishing white matter patient brains, axons and myelin sheaths were thinner than normal in moderately and severely affected white matter. In mutant mice and patients, signs of axonal transport defects and cytoskeletal abnormalities were minimal. InterpretationIn vanishing white matter, axons are initially normal and atrophy later. Astrocytes are central in this process. If therapy becomes available, axonal pathology may be prevented with early intervention

    A common and functional mineralocorticoid receptor haplotype enhances optimism and protects against depression in females

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    Mineralocorticoid (MR) and glucocorticoid receptors (GR) are abundantly expressed in the limbic brain and mediate cortisol effects on the stress-response and behavioral adaptation. Dysregulation of the stress response impairs adaptation and is a risk factor for depression, which is twice as abundant in women than in men. Because of the importance of MR for appraisal processes underlying the initial phase of the stress response we investigated whether specific MR haplotypes were associated with personality traits that predict the risk of depression. We discovered a common gene variant (haplotype 2, frequency ∟0.38) resulting in enhanced MR activity. Haplotype 2 was associated with heightened dispositional optimism in study 1 and with less hopelessness and rumination in study 2. Using data from a large genome-wide association study we then established that haplotype 2 was associated with a lower risk of depression. Interestingly, all effects were restricted to women. We propose that common functional MR haplotypes are important determinants of inter-individual variability in resilience to depression in women by differentially mediating cortisol effects on the stress system

    Incomplete echocardiographic recovery at 6\ua0months predicts long-term sequelae after intermediate-risk pulmonary embolism. A post-hoc analysis of the Pulmonary Embolism Thrombolysis (PEITHO) trial

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    Introduction: Symptoms and functional limitation are frequently reported by survivors of acute pulmonary embolism (PE). However, current guidelines provide no specific recommendations on which patients should be followed after acute PE, when follow-up should be performed, and which tests it should include. Definition and classification of late PE sequelae are evolving, and their predictors remain to be determined. Methods: In a post hoc analysis of the Pulmonary Embolism Thrombolysis (PEITHO) trial, we focused on 219 survivors of acute intermediate-risk PE with clinical and echocardiographic follow-up 6 months after randomisation as well as over the long term (median, 3 years after acute PE). The primary outcome was a composite of (1) confirmed chronic thromboembolic pulmonary hypertension (CTEPH) or (2) \u2018post-PE impairment\u2019 (PPEI), defined by echocardiographic findings indicating an intermediate or high probability of pulmonary hypertension along with New York Heart Association functional class II\u2013IV. Results: Confirmed CTEPH or PPEI occurred in 29 (13.2%) patients, (6 with CTEPH and 23 with PPEI). A history of chronic heart failure at baseline and incomplete or absent recovery of echocardiographic parameters at 6 months predicted CTEPH or PPEI at long-term follow-up. Conclusions: CTEPH or PPEI occurs in almost one out of seven patients after acute intermediate-risk PE. Six-month echocardiographic follow-up may be useful for timely detection of late sequelae

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Pulmonary and cardiac variables associated with persistent dyspnea after pulmonary embolism

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    Introduction: Persistent dyspnea is common in follow-up after pulmonary embolism (PE), but the underlying mechanisms are poorly understood. Material and methods: This cross-sectional study included subjects aged 18?75 years with confirmed PE by computed tomography pulmonary angiography (CTPA) 6?72 months earlier. A total of 180 participants underwent clinical examination, incremental shuttle walk test, laboratory tests, transthoracic echocardiography, pulmonary function tests and ventilation/perfusion scintigraphy. In further analysis, we divided participants into two groups; ?dyspnea? or ?no dyspnea?, based on interview and questionnaires at inclusion. The association of cardiac and pulmonary variables with persistent dyspnea was assessed using multiple logistic regression analysis. Results: In total, 44% (95% CI: 39%?51%) of the participants reported persistent dyspnea after PE. Age (adjusted odds ratio (aOR) 0.93 per year, 95% CI: 0.90?0.97, P = 0.001), body mass index (BMI) (aOR 1.14 per kg/m2, 95% CI: 1.04?1.25, P = 0.004), recurrent venous thromboembolism (VTE) (aOR 3.69, 95% CI: 1.45?9.38, P = 0.006) and diffusion capacity of the lung for carbon monoxide (DLCO) (aOR 0.95 per increase of 1%, 95% CI: 0.92?0.98, P = 0.001) were independently associated with persistent dyspnea. Conclusions: Persistent dyspnea was prevalent after PE. Age, BMI and recurrent VTE were independently associated with dyspnea. Apart from reduced DLCO, no other cardiac or pulmonary variables were associated with persistent dyspnea.Thrombosis and Hemostasi

    Standalone vertex nding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011
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