305 research outputs found

    Berichte aus dem Ökolandbau

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    In diesem Heft der Schriftenreihe des Landesamtes für Umwelt, Landwirtschaft und Geologie sind folgende drei Beiträge enthalten: Einfluss des Klimawandels auf Humus- und Stickstoffvorräte im Boden sowie Kompensationsmöglichkeiten durch den Ökologischen Landbau. Am Beispiel von drei Agrarstrukturgebieten in Sachsen wurden zunächst mit Hilfe mehrerer Methoden der Humusbilanzierung die Auswirkungen des Klimawandels bis zum Jahr 2050 ermittelt. Die Ergebnisse zeigen, dass die Humusgehalte auf den Diluvial- und Lößböden leicht und den Verwitterungsstandorten der Bergregionen deutlich abnehmen können. Durch verschiedene Formen des ökologischen Landbaus (Ist-Situation, Marktfrucht, Futterbau, organische Düngung, Umwidmung zu Grünland) kann diesem Trend in unterschiedlichem Ausmaß entgegengewirkt werden. Nähr- und Schadstoffgehalte von Wirtschaftsdüngern in Sachsen. In den Jahren 2006 und 2007 wurde eine umfassende Erhebung an Wirtschaftsdüngern von ökologisch wirtschaftenden Betrieben in Sachsen durchgeführt. Von den Hauptnährstoffen wurden die Gehalte an Stickstoff, Phosphor, Kalium, Magnesium, Calcium, Natrium und Schwefel ermittelt. Durch die Ergebnisse wurden im Vergleich zu konventionellen Standardwerten niedrigere N- und K-Gehalte in den Wirtschaftsdüngern ökologischen Ursprungs bestätigt. Auch reicht das Datenmaterial erstmals aus, um die NH4-N-Anteile in den Düngemitteln genauer abschätzen zu können. Die hier präsentierten Untersuchungsergebnisse können zur weiteren Verbesserung von ökologischen Richtwerten genutzt werden. Gleichfalls durchgeführte Untersuchungen zum Schwermetall- und Arsengehalt der Wirtschaftsdünger ergaben für die überwiegende Mehrzahl der untersuchten Proben lediglich geringe Belastungen. Eignung nichtlegumer Zwischenfrüchte vor dem Anbau von Körnerleguminosen. Im Jahr 2008 wurden an drei Standorten in Sachsen Feldversuche zur Eignung nichtlegumer Zwischenfrüchte für Systeme der Mulch- und Direktsaat von Körnerleguminosen durchgeführt. Von den geprüften Zwischenfrüchten Sommerroggen, Schwarzhafer, Sonnenblume, Weißer Senf, Buchweizen und Hanf waren nahezu unabhängig vom Standort insbesondere Sommerroggen und Hafer aufgrund guter Unkrautunterdrückung und hohem Sprossertrag am besten geeignet

    Platelet G i protein Gα i2 is an essential mediator of thrombo-inflammatory organ damage in mice

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    Platelets are crucial for hemostasis and thrombosis and exacerbate tissue injury following ischemia and reperfusion. Important regulators of platelet function are G proteins controlled by seven transmembrane receptors. The Gi protein Gα(i2) mediates platelet activation in vitro, but its in vivo role in hemostasis, arterial thrombosis, and postischemic infarct progression remains to be determined. Here we show that mice lacking Gα(i2) exhibit prolonged tail-bleeding times and markedly impaired thrombus formation and stability in different models of arterial thrombosis. We thus generated mice selectively lacking Gα(i2) in megakaryocytes and platelets (Gna(i2)(fl/fl)/PF4-Cre mice) and found bleeding defects comparable to those in global Gα(i2)-deficient mice. To examine the impact of platelet Gα(i2) in postischemic thrombo-inflammatory infarct progression, Gna(i2)(fl/fl)/PF4-Cre mice were subjected to experimental models of cerebral and myocardial ischemia/reperfusion injury. In the model of transient middle cerebral artery occlusion stroke Gna(i2)(fl/fl)/PF4-Cre mice developed significantly smaller brain infarcts and fewer neurological deficits than littermate controls. Following myocardial ischemia, Gna(i2)(fl/fl)/PF4-Cre mice showed dramatically reduced reperfusion injury which correlated with diminished formation of the ADP-dependent platelet neutrophil complex. In conclusion, our data provide definitive evidence that platelet Gα(i2) not only controls hemostatic and thrombotic responses but also is critical for the development of ischemia/reperfusion injury in vivo.Fil: Devanathan, Vasudharani. University of Tübingen; AlemaniaFil: Hagedorn, Ina. University Hospital; AlemaniaFil: Köhler, David. University of Tübingen; AlemaniaFil: Pexa, Katja. Universitat Dusseldorf; AlemaniaFil: Cherpokova, Deya. University Hospital; AlemaniaFil: Kraft, Peter. Universität Würzburg; AlemaniaFil: Singh, Madhurendra. Universitat Dusseldorf; AlemaniaFil: Rosenberger, Peter. University of Tübingen; AlemaniaFil: Stoll, Guido. Universität Würzburg; AlemaniaFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Research Triangle Park; AlemaniaFil: Piekorz, Roland P.. Universitat Dusseldorf; AlemaniaFil: Beer-Hammer, Sandra. University of Tübingen; AlemaniaFil: Nieswandt, Bernhard. University Hospital; AlemaniaFil: Nürnberg, Bernd. University of Tübingen; Alemani

    Free tissue transfer after unsatisfactorily implant-based breast reconstruction, a cohort study

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    Breast reconstruction can be performed using implants or autologous tissue, either alone or in combination. Implants typically require re-operation during the patient's lifetime, often for adverse capsular contracture. Conversion from implants to autologous tissue may improve symptoms and deliver a definitive reconstruction. This is known as salvage breast reconstruction. In this paper we evaluate the indications, outcomes, complications and cost implications of salvage breast reconstruction in our regional centre and report these in line with the STROBE guidelines. Retrospective casenote analysis of all salvage breast reconstruction patients from January 2018 to January 2020 was performed. Nineteen patients were identified, with a median age of 52 years. Indications were all capsular contracture other than two each of implant rupture and patient request. Thirty-two perforator free flaps; 29 deep inferior epigastric, two profunda artery and one lateral thoracic artery flap were performed. Median time from first implant to free flap reconstruction was nine years. Median hospital stay was five days. No total flap losses and one partial flap loss occurred. Three patients underwent secondary procedures to the breast to improve the aesthetic outcome. All patients reported improvement in symptoms and appearance. For implant-intolerant patients adequately counselled and accepting of the post-operative downtime, salvage reconstruction with autogenous tissue offers a lasting solution. The upfront healthcare costs are higher with a free tissue transfer, but may become comparable longer term given the multiple exchange of implant procedures required over a patient's lifetime

    Elasticity and adhesion of resting and lipopolysaccharide-stimulated macrophages

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    AbstractColloidal Force Microscopy was employed to study the viscoelastic and adhesive properties of macrophages upon stimulation with lipopolysaccharide (LPS). Force vs. distance measurements were performed. The adhesion of LPS-stimulated cells (separation force=37±3nN) was almost twice as high as that of resting macrophages (16±1nN). Upon retraction pulling of membrane tethers was observed. Tether lengths and forces at which rupture take place did not depend on stimulation. The reduced Young’s modulus K, a measure of cytoskeleton elasticity, was three times lower than that of the control. The data show that LPS has profound effects on cytomechanical and adhesion properties of macrophages

    Scuba:Scalable kernel-based gene prioritization

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    Abstract Background The uncovering of genes linked to human diseases is a pressing challenge in molecular biology and precision medicine. This task is often hindered by the large number of candidate genes and by the heterogeneity of the available information. Computational methods for the prioritization of candidate genes can help to cope with these problems. In particular, kernel-based methods are a powerful resource for the integration of heterogeneous biological knowledge, however, their practical implementation is often precluded by their limited scalability. Results We propose Scuba, a scalable kernel-based method for gene prioritization. It implements a novel multiple kernel learning approach, based on a semi-supervised perspective and on the optimization of the margin distribution. Scuba is optimized to cope with strongly unbalanced settings where known disease genes are few and large scale predictions are required. Importantly, it is able to efficiently deal both with a large amount of candidate genes and with an arbitrary number of data sources. As a direct consequence of scalability, Scuba integrates also a new efficient strategy to select optimal kernel parameters for each data source. We performed cross-validation experiments and simulated a realistic usage setting, showing that Scuba outperforms a wide range of state-of-the-art methods. Conclusions Scuba achieves state-of-the-art performance and has enhanced scalability compared to existing kernel-based approaches for genomic data. This method can be useful to prioritize candidate genes, particularly when their number is large or when input data is highly heterogeneous. The code is freely available at https://github.com/gzampieri/Scuba

    The Added Value of Large-Eddy and Storm-Resolving Models for Simulating Clouds and Precipitation

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    More than one hundred days were simulated over very large domains with fine (0.156 km to 2.5 km) grid spacing for realistic conditions to test the hypothesis that storm (kilometer) and large-eddy (hectometer) resolving simulations would provide an improved representation of clouds and precipitation in atmospheric simulations. At scales that resolve convective storms (storm-resolving for short), the vertical velocity variance becomes resolved and a better physical basis is achieved for representing clouds and precipitation. Similarly to past studies we found an improved representation of precipitation at kilometer scales, as compared to models with parameterized convection. The main precipitation features (location, diurnal cycle and spatial propagation) are well captured already at kilometer scales, and refining resolution to hectometer scales does not substantially change the simulations in these respects. It does, however, lead to a reduction in the precipitation on the time-scales considered – most notably over the ocean in the tropics. Changes in the distribution of precipitation, with less frequent extremes are also found in simulations incorporating hectometer scales. Hectometer scales appear to be more important for the representation of clouds, and make it possible to capture many important aspects of the cloud field, from the vertical distribution of cloud cover, to the distribution of cloud sizes, and to the diel (daily) cycle. Qualitative improvements, particularly in the ability to differentiate cumulus from stratiform clouds, are seen when one reduces the grid spacing from kilometer to hectometer scales. At the hectometer scale new challenges arise, but the similarity of observed and simulated scales, and the more direct connection between the circulation and the unconstrained degrees of freedom make these challenges less daunting. This quality, combined with already improved simulation as compared to more parameterized models, underpins our conviction that the use and further development of storm-resolving models offers exciting opportunities for advancing understanding of climate and climate change

    The Pierre Auger Observatory Open Data

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    The Pierre Auger Collaboration has embraced the concept of open access to their research data since its foundation, with the aim of giving access to the widest possible community. A gradual process of release began as early as 2007 when 1% of the cosmic-ray data was made public, along with 100% of the space-weather information. In February 2021, a portal was released containing 10% of cosmic-ray data collected from 2004 to 2018, during Phase I of the Observatory. The Portal included detailed documentation about the detection and reconstruction procedures, analysis codes that can be easily used and modified and, additionally, visualization tools. Since then the Portal has been updated and extended. In 2023, a catalog of the 100 highest-energy cosmic-ray events examined in depth has been included. A specific section dedicated to educational use has been developed with the expectation that these data will be explored by a wide and diverse community including professional and citizen-scientists, and used for educational and outreach initiatives. This paper describes the context, the spirit and the technical implementation of the release of data by the largest cosmic-ray detector ever built, and anticipates its future developments.Comment: 19 pages, 8 figure

    Radio Measurements of the Depth of Air-Shower Maximum at the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest array of radio antenna stations deployed for the detection of cosmic rays, spanning an area of 1717 km2^2 with 153 radio stations. It detects the radio emission of extensive air showers produced by cosmic rays in the 308030-80 MHz band. Here, we report the AERA measurements of the depth of the shower maximum (XmaxX_\text{max}), a probe for mass composition, at cosmic-ray energies between 1017.510^{17.5} to 1018.810^{18.8} eV, which show agreement with earlier measurements with the fluorescence technique at the Pierre Auger Observatory. We show advancements in the method for radio XmaxX_\text{max} reconstruction by comparison to dedicated sets of CORSIKA/CoREAS air-shower simulations, including steps of reconstruction-bias identification and correction, which is of particular importance for irregular or sparse radio arrays. Using the largest set of radio air-shower measurements to date, we show the radio XmaxX_\text{max} resolution as a function of energy, reaching a resolution better than 1515 g cm2^{-2} at the highest energies, demonstrating that radio XmaxX_\text{max} measurements are competitive with the established high-precision fluorescence technique. In addition, we developed a procedure for performing an extensive data-driven study of systematic uncertainties, including the effects of acceptance bias, reconstruction bias, and the investigation of possible residual biases. These results have been cross-checked with air showers measured independently with both the radio and fluorescence techniques, a setup unique to the Pierre Auger Observatory.Comment: Submitted to Phys. Rev.

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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