383 research outputs found
Berichte aus dem Ökolandbau
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
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
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
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
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
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
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
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 km with 153
radio stations. It detects the radio emission of extensive air showers produced
by cosmic rays in the MHz band. Here, we report the AERA measurements
of the depth of the shower maximum (), a probe for mass
composition, at cosmic-ray energies between to eV,
which show agreement with earlier measurements with the fluorescence technique
at the Pierre Auger Observatory. We show advancements in the method for radio
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 resolution as a function of energy, reaching a
resolution better than g cm at the highest energies, demonstrating
that radio 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.
Ground observations of a space laser for the assessment of its in-orbit performance
The wind mission Aeolus of the European Space Agency was a groundbreaking
achievement for Earth observation. Between 2018 and 2023, the space-borne lidar
instrument ALADIN onboard the Aeolus satellite measured atmospheric wind
profiles with global coverage which contributed to improving the accuracy of
numerical weather prediction. The precision of the wind observations, however,
declined over the course of the mission due to a progressive loss of the
atmospheric backscatter signal. The analysis of the root cause was supported by
the Pierre Auger Observatory in Argentina whose fluorescence detector
registered the ultraviolet laser pulses emitted from the instrument in space,
thereby offering an estimation of the laser energy at the exit of the
instrument for several days in 2019, 2020 and 2021. The reconstruction of the
laser beam not only allowed for an independent assessment of the Aeolus
performance, but also helped to improve the accuracy in the determination of
the laser beam's ground track on single pulse level. The results presented in
this paper set a precedent for the monitoring of space lasers by ground-based
telescopes and open new possibilities for the calibration of cosmic-ray
observatories.Comment: 10 pages, 10 figure
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