38 research outputs found

    Landscape-use optimisation with regards to the groundwater resources protection in mountain hardrock areas, LOWRGREP

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    Synthesis of work performed during the European Project LOWRGREPThis report assesses the degree of interference of human activities with the hydrosphere in mountain-zones, all located in hard-rock areas of different countries in the European Union. Each of the test-regions has a specific degree of protection: from regions with very few inhabitants and very low human impact, to regions submitted to a strong anthropogenic impact. The investigations focused on the changes in water quality and on the simulation of various alternatives leading to optimum landscape-use from the point of view of water-management. The project's own Geographic Information System was used to fulfil the following objective: present all the obtained knowledge and analyse all the data in user-friendly form (maps of water vulnerability) and make this knowledge available for potential users with, for instance, the creation and use of a web site. A simulation tool has been developed which facilitates the assessment of the impact of landscape-use on the water budget of the catchment. In all the areas investigated chloride is present, only in winter and very close to roads. Another result of this work is the decreasing impact on water of sulphur and sulphuric compounds in Germany and in the Czech Republic, while the nitrogen impact is increasing. Recommendations concerning the landscape-use presented for all the regions in particular for good practices in agricultur

    HmuY Haemophore and Gingipain Proteases Constitute a Unique Syntrophic System of Haem Acquisition by Porphyromonas gingivalis

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    Haem (iron protoporphyrin IX) is both an essential growth factor and virulence regulator for the periodontal pathogen Porphyromonas gingivalis, which acquires it mainly from haemoglobin via the sequential actions of the R- and K-specific gingipain proteases. The haem-binding lipoprotein haemophore HmuY and its cognate receptor HmuR of P. gingivalis, are responsible for capture and internalisation of haem. This study examined the role of the HmuY in acquisition of haem from haemoglobin and the cooperation between HmuY and gingipain proteases in this process. Using UV-visible spectroscopy and polyacrylamide gel electrophoresis, HmuY was demonstrated to wrest haem from immobilised methaemoglobin and deoxyhaemoglobin. Haem extraction from oxyhaemoglobin was facilitated after oxidation to methaemoglobin by pre-treatment with the P. gingivalis R-gingipain A (HRgpA). HmuY was also capable of scavenging haem from oxyhaemoglobin pre-treated with the K-gingipain (Kgp). This is the first demonstration of a haemophore working in conjunction with proteases to acquire haem from haemoglobin. In addition, HmuY was able to extract haem from methaemalbumin, and could bind haem, either free in solution or from methaemoglobin, even in the presence of serum albumin
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