500 research outputs found

    Meeresatlas: Daten und Fakten über unseren Umgang mit dem Ozean

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    Ohne das Meer gäbe es kein Leben auf unserem Planeten. Es regelt weitgehend das Klima, gibt uns Nahrung und liefert Energie. Darüber hinaus ist es ein wichtiger Verkehrsweg, ein Erholungsraum und ein Quell ästhetischen Vergnügens. Aber das Meer steht unter Stress, denn das alte Prinzip von der „Freiheit der Meere“ hat zu Überfischung, Artenverlust und einer immensen Verschmutzung der Ozeane geführt. Deshalb muss der Umgang mit dem Meer auf nachhaltige und gerechte Grundlagen gestellt werden. Der Meeresatlas 2017 liefert dazu die Daten, Fakten und Zusammenhänge. Er zeigt in zahlreichen Beiträgen und über 50 Grafiken, in welch schlechtem Zustand sich die Weltmeere befinden, warum das so ist und was man tun muss, um die Situation der Ozeane zu verbessern

    Effects of parental acclimation and energy limitation in response to high CO2 exposure in Atlantic cod

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    Ocean acidification (OA), the dissolution of excess anthropogenic carbon dioxide in ocean waters, is a potential stressor to many marine fish species. Whether species have the potential to acclimate and adapt to changes in the seawater carbonate chemistry is still largely unanswered. Simulation experiments across several generations are challenging for large commercially exploited species because of their long generation times. For Atlantic cod (Gadus morhua), we present first data on the effects of parental acclimation to elevated aquatic CO2 on larval survival, a fundamental parameter determining population recruitment. The parental generation in this study was exposed to either ambient or elevated aquatic CO2 levels simulating end-of-century OA levels (~1100 µatm CO2) for six weeks prior to spawning. Upon fully reciprocal exposure of the F1 generation, we quantified larval survival, combined with two larval feeding regimes in order to investigate the potential effect of energy limitation. We found a significant reduction in larval survival at elevated CO2 that was partly compensated by parental acclimation to the same CO2 exposure. Such compensation was only observed in the treatment with high food availability. This complex 3-way interaction indicates that surplus metabolic resources need to be available to allow a transgenerational alleviation response to ocean acidification

    Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: A prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting

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    AbstractObjective: Retrospective comparisons of selected patients undergoing off-pump versus conventional on-pump coronary artery bypass grafting have yielded inconsistent results and raised concerns about completeness of revascularization in off-pump coronary artery bypass grafting. Methods: Two hundred unselected patients referred for elective primary coronary artery bypass grafting were randomly assigned to undergo off-pump coronary artery bypass grafting with an Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, Minn) or conventional coronary artery bypass grafting with cardiopulmonary bypass by a single surgeon. Revascularization intent determined before random assignment was compared with the revascularization performed. All management followed strict, unbiased, criteria-driven protocols. Patients and nonoperative care providers were blinded to surgical group. Results: Baseline characteristics were similar. The number of grafts performed per patient (mean ± SD 3.39 ± 1.04 for off-pump coronary artery bypass grafting, 3.40 ± 1.08 for conventional coronary artery bypass grafting) and the index of completeness of revascularization (number of grafts performed/number of grafts intended, 1.00 ± 0.18 for off-pump coronary artery bypass grafting, 1.01 ± 0.09 for conventional coronary artery bypass grafting) were similar. Likewise, the index of completeness of revascularization was similar between groups for the lateral wall. Combined hospital and 30-day mortalities and stroke rates were similar. Postoperative myocardial serum enzyme measures were significantly lower after off-pump coronary artery bypass grafting, suggesting less myocardial injury. Adjusted postoperative thromboelastogram indices, fibrinogen, international normalized ratio, and platelet levels all showed significantly less coagulopathy after off-pump coronary artery bypass grafting. Patients undergoing off-pump coronary artery bypass grafting received fewer units of blood, were more likely to avoid transfusion altogether, and had a higher hematocrit at discharge. Cardiopulmonary bypass was an independent predictor of transfusion (odds ratio 2.42, P =.0073) by multivariate analysis. More patients undergoing off-pump coronary artery bypass grafting were extubated in the operating room and within 4 hours. Postoperative length of stay (in days) was shorter for off-pump coronary artery bypass grafting (5.1 ± 6.5 for off-pump coronary artery bypass grafting, 6.1 ± 8.2 for conventional coronary artery bypass grafting, P =.005 by Wilcoxon test). One patient (in the conventional coronary artery bypass grafting group) required angioplasty for graft closure within 30 days. Conclusions: When compared with conventional coronary artery bypass grafting with cardiopulmonary bypass, off-pump coronary artery bypass grafting achieved similar completeness of revascularization, similar in-hospital and 30-day outcomes, shorter length of stay, reduced transfusion requirement, and less myocardial injury.J Thorac Cardiovasc Surg 2003;125:797-80

    Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: A prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting

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    AbstractObjective: Retrospective comparisons of selected patients undergoing off-pump versus conventional on-pump coronary artery bypass grafting have yielded inconsistent results and raised concerns about completeness of revascularization in off-pump coronary artery bypass grafting. Methods: Two hundred unselected patients referred for elective primary coronary artery bypass grafting were randomly assigned to undergo off-pump coronary artery bypass grafting with an Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, Minn) or conventional coronary artery bypass grafting with cardiopulmonary bypass by a single surgeon. Revascularization intent determined before random assignment was compared with the revascularization performed. All management followed strict, unbiased, criteria-driven protocols. Patients and nonoperative care providers were blinded to surgical group. Results: Baseline characteristics were similar. The number of grafts performed per patient (mean ± SD 3.39 ± 1.04 for off-pump coronary artery bypass grafting, 3.40 ± 1.08 for conventional coronary artery bypass grafting) and the index of completeness of revascularization (number of grafts performed/number of grafts intended, 1.00 ± 0.18 for off-pump coronary artery bypass grafting, 1.01 ± 0.09 for conventional coronary artery bypass grafting) were similar. Likewise, the index of completeness of revascularization was similar between groups for the lateral wall. Combined hospital and 30-day mortalities and stroke rates were similar. Postoperative myocardial serum enzyme measures were significantly lower after off-pump coronary artery bypass grafting, suggesting less myocardial injury. Adjusted postoperative thromboelastogram indices, fibrinogen, international normalized ratio, and platelet levels all showed significantly less coagulopathy after off-pump coronary artery bypass grafting. Patients undergoing off-pump coronary artery bypass grafting received fewer units of blood, were more likely to avoid transfusion altogether, and had a higher hematocrit at discharge. Cardiopulmonary bypass was an independent predictor of transfusion (odds ratio 2.42, P =.0073) by multivariate analysis. More patients undergoing off-pump coronary artery bypass grafting were extubated in the operating room and within 4 hours. Postoperative length of stay (in days) was shorter for off-pump coronary artery bypass grafting (5.1 ± 6.5 for off-pump coronary artery bypass grafting, 6.1 ± 8.2 for conventional coronary artery bypass grafting, P =.005 by Wilcoxon test). One patient (in the conventional coronary artery bypass grafting group) required angioplasty for graft closure within 30 days. Conclusions: When compared with conventional coronary artery bypass grafting with cardiopulmonary bypass, off-pump coronary artery bypass grafting achieved similar completeness of revascularization, similar in-hospital and 30-day outcomes, shorter length of stay, reduced transfusion requirement, and less myocardial injury.J Thorac Cardiovasc Surg 2003;125:797-80

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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