RESUMEN
Due to extreme weather events and deforestation the physical and chemical characteristics of watersheds in mountain areas could exceed the known variations. Therefore, the spring water of the Innerste river in the Western Harz Mountains (Germany) was monitored from 2020 to 2023. The monitoring approach is simple and can be directly transferred to other watersheds of springs which are connected to the meteoric water cycle. The specific electrical conductivity (SEC) of the water is compared to daily precipitation data. The SEC values range between 50 and 100 µS/cm. In September 2020 and July 2022 the spring dried out. A hysteretic relationship between spring runoff and spring water mineralisation was found. The SEC values of the spring water are rising during dry periods or in winter seasons with a long ice cover in the catchment area. The highest SEC values are typical for long dry periods and flush events after the drying out of the spring. The relationship of SEC and major ions of the spring water (especially bicarbonate) indicates that biogeochemical processes within the soil zone and water-rock interactions in fractured shales and greywackes of the catchment area control the chemical composition of the spring water. Comparing the obtained results with data measured before the first observed drying out of the spring, no unexpected new values and correlations of runoff, SEC values and ion concentrations were found.
RESUMEN
Three species of white-toothed shrews of the order Eulipotyphla are present in central Europe: the bicolored (Crocidura leucodon), greater (Crocidura russula) and lesser (Crocidura suaveolens) white-toothed shrews. Their precise distribution in Germany is ill-defined and little is known about them as reservoirs for zoonotic pathogens (Leptospira spp., Coxiella burnetii, Brucella spp., Anaplasma phagocytophilum, Babesia spp., Neoehrlichia mikurensis and Bartonella spp.). We investigated 372 Crocidura spp. from Germany (n = 341), Austria (n = 18), Luxembourg (n = 2) and Slovakia (n = 11). West European hedgehogs (Erinaceus europaeus) were added to compare the presence of pathogens in co-occurring insectivores. Crocidura russula were distributed mainly in western and C. suaveolens mainly in north-eastern Germany. Crocidura leucodon occurred in overlapping ranges with the other shrews. Leptospira spp. DNA was detected in 28/227 C. russula and 2/78 C. leucodon samples. Further characterization revealed that Leptospira kirschneri had a sequence type (ST) 100. Neoehrlichia mikurensis DNA was detected in spleen tissue from 2/213 C. russula samples. Hedgehogs carried DNA from L. kirschneri (ST 100), L. interrogans (ST 24), A. phagocytophilum and two Bartonella species. This study improves the knowledge of the current distribution of Crocidura shrews and identifies C. russula as carrier of Leptospira kirschneri. However, shrews seem to play little-to-no role in the circulation of the arthropod-borne pathogens investigated.
RESUMEN
After having translated short upstream open reading frames, ribosomes can re-initiate translation on the same mRNA. This process, referred to as re-initiation, controls the translation of a large fraction of mammalian cellular mRNAs, many of which are important in cancer. Key ribosomal binding proteins involved in re-initiation are the eukaryotic translation initiation factor 2D (eIF2D) or the homologous complex of MCT-1/DENR. We determined the structures of these factors bound to the human 40S ribosomal subunit in complex with initiator tRNA positioned on an mRNA start codon in the P-site using a combination of cryoelectron microscopy and X-ray crystallography. The structures, supported by biochemical experiments, reveal how eIF2D emulates the function of several canonical translation initiation factors by using three independent, flexibly connected RNA binding domains to simultaneously monitor codon-anticodon interactions in the ribosomal P-site and position the initiator tRNA.