443 research outputs found

    Rain erosivity map for Germany derived from contiguous radar rain data

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    Erosive rainfall varies pronouncedly in time and space. Severe events are often restricted to a few square kilometers. Radar rain data with high spatiotemporal resolution enable this pattern of erosivity to be portrayed with high detail. We used radar data with a spatial resolution of 1 km"span class="inline-formula"""sup"2"/sup""/span" over 452 503 km"span class="inline-formula"""sup"2"/sup""/span" to derive a new erosivity map for Germany and to analyze the seasonal distribution of erosivity. The expected long-term regional pattern was extracted from the scattered pattern of events by several steps of smoothing. This included averaging erosivity from 2001 to 2017 and smoothing in time and space. The pattern of the resulting map was predominantly shaped by orography. It generally agrees well with the erosivity map currently used in Germany (Sauerborn map), which is based on regressions using rain gauge data (mainly from the 1960s to 1980s). In some regions the patterns of both maps deviate because the regressions of the Sauerborn map were weak. Most importantly, the new map shows that erosivity is about 66 % larger than in the Sauerborn map. This increase in erosivity was confirmed by long-term data from rain gauge stations that were used for the Sauerborn map and which are still in operation. The change was thus not caused by using a different methodology but by climate change since the 1970s. Furthermore, the seasonal distribution of erosivity shows a slight shift towards the winter period when soil cover by plants is usually poor. This shift in addition to the increase in erosivity may have caused an increase in erosion for many crops. For example, predicted soil erosion for winter wheat is now about 4 times larger than in the 1970s. These highly resolved topical erosivity data will thus have definite consequences for agricultural advisory services, landscape planning and even political decisions. Document type: Articl

    Temporary inhibition of papain by hairpin loop mutants of chicken cystatin Distorted binding of the loops results in cleavage of the Gly9-Ala10 bond

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    AbstractTemporary inhibition of the cysteine proteinases papain and cathepsin L was observed with several hairpin loop mutants of recombinant chicken cystatin at enzyme concentrations above nanomolar. Kinetic modelling of inhibition data, gel electrophoresis and amino acid sequencing revealed that reappearance of papain activity is due to selective cleavage of the Gly9-Ala10 bond in the N-terminal binding area of the chicken cystatin variants, resulting in truncated inhibitors of lower affinity. Cleavage of the same bond by contaminating papaya proteinase IV was ruled out by previous purification of papain and suitable control experiments. According to the proposed kinetic model, cleavage occurs within the enzyme-inhibitor complex with first order rate constants ktemp of 2.3 × 10−3 up to 5 × 10−1 s−1. A similar ktempKm ratio was found for all mutants (0.7 × 106–2.1 × 106 s−1·M−1); it is almost identical with the kcatKm ratio of the peptide substrate Z-Phe-Arg-NHMec. These results suggest that distorted contacts of one of the hairpin loops affect binding of the N-terminal contact area in a way that covalent interaction of the Gly9-Ala10 bond with the active-site Cys residue of papain can occur and the bond is cleaved in a substrate-like manner

    Temporal- and spatial-scale and positional effects on rain erosivity derived from point-scale and contiguous rain data

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    Up until now, erosivity required for soil loss predictions has been mainly estimated from rain gauge data at point scale and then spatially interpolated to erosivity maps. Contiguous rain data from weather radar measurements, satellites, cellular communication networks and other sources are now available, but they differ in measurement method and temporal and spatial scale from data at point scale. We determined how the intensity threshold of erosive rains has to be modified and which scaling factors have to be applied to account for the differences in method and scales. Furthermore, a positional effect quantifies heterogeneity of erosivity within 1&thinsp;km2, which presently is the highest resolution of freely available gauge-adjusted radar rain data. These effects were analysed using several large data sets with a total of approximately 2×106 erosive events (e.g. records of 115 rain gauges for 16 years distributed across Germany and radar rain data for the same locations and events). With decreasing temporal resolution, peak intensities decreased and the intensity threshold was met less often. This became especially pronounced when time increments became larger than 30&thinsp;min. With decreasing spatial resolution, intensity peaks were also reduced because additionally large areas without erosive rain were included within one pixel. This was due to the steep spatial gradients in erosivity. Erosivity of single events could be zero or more than twice the mean annual sum within a distance of less than 1&thinsp;km. We conclude that the resulting large positional effect requires use of contiguous rain data, even over distances of less than 1&thinsp;km, but at the same time contiguously measured radar data cannot be resolved to point scale. The temporal scale is easier to consider, but with time increments larger than 30&thinsp;min the loss of information increases considerably. We provide functions to account for temporal scale (from 1 to 120&thinsp;min) and spatial scale (from rain gauge to pixels of 18&thinsp;km width) that can be applied to rain gauge data of low temporal resolution and to contiguous rain data.</p

    HESS Opinions: Socio-economic and ecological trade-offs of flood management – benefits of a transdisciplinary approach

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    In light of climate change and growing numbers of people inhabiting riverine floodplains, worldwide demand for flood protection is increasing, typically through engineering approaches such as more and bigger levees. However, the well-documented “levee effect” of increased floodplain use following levee construction or enhancement often results in increased problems, especially when levees fail or are compromised by big flood events. Herein, we argue that there are also unintended socio-economic and ecological consequences of traditional engineering solutions that need to be better considered, communicated and weighed against alternative solutions. Socio-economic consequences include reduced aesthetic and recreational values as well as increased downstream flooding risk and reduced ecosystem services. Ecological consequences include hydraulic decoupling, loss of biodiversity and increased risk of contamination during flooding. In addition, beyond river losses of connectivity and natural riparian vegetation created by levees, changes in groundwater levels and increased greenhouse gas emissions are likely. Because flood protection requires huge financial investments and results in major and persistent changes to the landscape, more balanced decisions that involve all stakeholders and policymakers should be made in the future. This requires a transdisciplinary approach that considers alternative solutions such as green infrastructure and places emphasis on integrated flood management rather than on reliance on technical protection measures.</p

    Intrinsic water-use efficiency of temperate seminatural grassland has increased since 1857: an analysis of carbon isotope discrimination of herbage from the Park Grass Experiment

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    A 150-year-long record of intrinsic water-use efficiency (W-i) was derived from community-level carbon isotope discrimination (13 delta) in the herbage of the unfertilized, unlimed control treatment (plot 3) of the Park Grass Experiment at Rothamsted (England) between 1857 and 2007. 13 delta during spring growth (first cut harvested in June) averaged 21.0 parts per thousand (+/- 0.5 parts per thousand SD) and has not shown a long-term trend (P=0.5) since 1857. 13 delta of summer/autumn growth (second cut harvested between September and November) increased from 21.3 parts per thousand to 22.0 parts per thousand (P < 0.001) between 1875 and 2007. W-i during spring growth has therefore increased by 33% since the beginning of the experiment, and W-i of summer/autumn growth has increased by 18%. The variation in 13 delta was mainly related to weather conditions. Plant available soil water explained 51% and 40% of the variation in spring growth 13 delta and summer/autumn growth 13 delta, respectively. In the 1857-2007 period yields have not increased, suggesting that community-level photosynthesis has not increased either. Therefore, the increased W-i probably resulted from a decreased stomatal conductance. Vapour pressure deficit (VPD) during spring growth (March-June) has not changed since 1915, meaning that instantaneous water-use efficiency (W-t) in spring time has increased and transpiration has probably decreased, provided that leaf temperature followed air temperature. Conversely, VPD in the months between the first and second cut has increased by 0.07 kPa since 1915, offsetting the effect of increased W-i on W-t during summer and early autumn. Our results suggest that vegetation has adjusted physiologically to elevated CO2 by decreasing stomatal conductance in this nutrient-limited grassland

    Rain erosivity map for Germany derived from contiguous radar rain data

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    Erosive rainfall varies pronouncedly in time and space. Severe events are often restricted to a few square kilometers. Radar rain data with high spatiotemporal resolution enable this pattern of erosivity to be portrayed with high detail. We used radar data with a spatial resolution of 1&thinsp;km2 over 452&thinsp;503&thinsp;km2 to derive a new erosivity map for Germany and to analyze the seasonal distribution of erosivity. The expected long-term regional pattern was extracted from the scattered pattern of events by several steps of smoothing. This included averaging erosivity from 2001 to 2017 and smoothing in time and space. The pattern of the resulting map was predominantly shaped by orography. It generally agrees well with the erosivity map currently used in Germany (Sauerborn map), which is based on regressions using rain gauge data (mainly from the 1960s to 1980s). In some regions the patterns of both maps deviate because the regressions of the Sauerborn map were weak. Most importantly, the new map shows that erosivity is about 66&thinsp;% larger than in the Sauerborn map. This increase in erosivity was confirmed by long-term data from rain gauge stations that were used for the Sauerborn map and which are still in operation. The change was thus not caused by using a different methodology but by climate change since the 1970s. Furthermore, the seasonal distribution of erosivity shows a slight shift towards the winter period when soil cover by plants is usually poor. This shift in addition to the increase in erosivity may have caused an increase in erosion for many crops. For example, predicted soil erosion for winter wheat is now about 4 times larger than in the 1970s. These highly resolved topical erosivity data will thus have definite consequences for agricultural advisory services, landscape planning and even political decisions.</p

    Diagnosis, therapeutic advances, and key recommendations for the management of factor X deficiency.

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    Factor X deficiency is a rare coagulation disorder that can be hereditary or acquired. The typology and severity of the associated bleeding symptoms are highly heterogeneous, adding to the difficulties of diagnosis and management. Evidence-based guidelines and reviews on factor X deficiency are generally limited to publications covering a range of rare bleeding disorders. Here we provide a comprehensive review of the literature on factor X deficiency, focusing on the hereditary form, and discuss the evolution in disease management and the evidence associated with available treatment options. Current recommendations advise clinicians to use single-factor replacement therapy for hereditary disease rather than multifactor therapies such as fresh frozen plasma, cryoprecipitate, and prothrombin complex concentrates. Consensus in treatment guidelines is still urgently needed to ensure optimal management of patients with factor X deficiency across the spectrum of disease severity

    Pleosporales

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    One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
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