Operational flood management under large-scale extreme conditions, using the example of the Middle Elbe

In addition to precautionary or technical flood protection measures, short-term strategies of the operational management, i.e. the initiation and co-ordination of preventive measures during and/or before a flood event are crucially for the reduction of the flood damages. This applies especially for extreme flood events. These events are rare, but may cause a protection measure to be overtopped or even to fail and be destroyed. In such extreme cases, reliable decisions must be made and emergency measures need to be carried out to prevent even larger damages from occurring. <br><br> Based on improved methods for meteorological and hydrological modelling a range of (physically based) extreme flood scenarios can be derived from historical events by modification of air temperature and humidity, shifting of weather fields and recombination of flood relevant event characteristics. By coupling the large scale models with hydraulic and geotechnical models, the whole flood-process-chain can be analysed right down to the local scale. With the developed GIS-based tools for hydraulic modelling <i>FlowGIS</i> and the Dike-Information-System, (IS-dikes) it is possible to quantify the endangering shortly before or even during a flood event, so the decision makers can evaluate possible options for action in operational mode

Genome-Wide Distribution of RNA-DNA Hybrids Identifies RNase H Targets in tRNA Genes, Retrotransposons and Mitochondria

During transcription, the nascent RNA can invade the DNA template, forming extended RNA-DNA duplexes (R-loops). Here we employ ChIP-seq in strains expressing or lacking RNase H to map targets of RNase H activity throughout the budding yeast genome. In wild-type strains, R-loops were readily detected over the 35S rDNA region, transcribed by Pol I, and over the 5S rDNA, transcribed by Pol III. In strains lacking RNase H activity, R-loops were elevated over other Pol III genes, notably tRNAs, SCR1 and U6 snRNA, and were also associated with the cDNAs of endogenous TY1 retrotransposons, which showed increased rates of mobility to the 5'-flanking regions of tRNA genes. Unexpectedly, R-loops were also associated with mitochondrial genes in the absence of RNase H1, but not of RNase H2. Finally, R-loops were detected on actively transcribed protein-coding genes in the wild-type, particularly over the second exon of spliced ribosomal protein genes

Die Wirkung estrogen aktiver Umweltchemikalien auf Fische Untersuchungen reproduktionsrelevanter Parameter bei Regenbogenforelle und Zebrabaerbling

The aim of the following dissertation was firstly the establishment of a new in situ method to localize vitellogenin (Vg) in hepatocytes of male fish after external stimulation with 17b-estradiol and secondly to elucidate the in vivo potential for endocrine disruption of different chemicals on fish populations. To accomplish these goals, immunhisto- and immuncytochemical tests on rainbow trout (Oncorhynchus mykiss) and life-cycle tests were carried out with zebrafish (Danio rerio) in a flow-trough system. Vg could be visualized with a polyclonal antibody against rainbow trout Vg after 17b-estradiol injection in liver of male and female rainbow trout. On a light microscopical level, antibodies primarily bound to regions around the nucleus, which contain, among other organelles, rER and Golgi fields, where Vg is synthesized. On an ultrastructural level, these organelles could be confirmed as the sites of vitellogenin synthesis. An endocrine action of nonylphenol (NP), octylphenol (OP) and dehydroepiandrosterone (DHEA) could be demonstrated in zebrafish. Chemically induced developmental, reproductive, anatomical, histological and ultrastructural changes were detectable in larvae as well as juvenil and adult fish. Exposition of zebrafish populations to NP, OP and DHEA led to a shift in sex ratio towards females in all cases. Furthermore treatment with NP, OP and DHEA resulted in conditional and structural changes of reproductive organs, skeleton and liver of zebrafish. A toxic action of NP, OP and DHEA could be proven after one week of exposure during embryonal and larval phase, while an estrogenic action of the chemicals could not be demonstrated until the completion of the full life-cycle exposure.Ziel der Dissertation war es, eine In situ-Methode zum Nachweis von Vitellogenin (Vg) nach 17b-Estrogen- und Xenoestrogen-Induktion in der Leber maennlicher Fische zu etablieren sowie die Wirkung verschiedener umweltrelevanter, estrogener Chemikalien auf eine Fischpopulation zu untersuchen. Hierzu wurden immunhisto- und immuncytochemische Untersuchungen an Regenbogenforellen (Oncorhynchus mykiss) und In vivo-Langzeitversuche mit Zebrabaerblingen (Danio rerio) ueber den gesamten Lebenszyklus im Durchflusssystem durchgefuehrt. Mit Hilfe eines polyklonalen Antikoerpers gegen Regenbogenforellen-Vg gelang es, nach 17b-Estradiol-Injektion Vg in der Leber weiblicher und maennlicher Regenbogenforellen nachzuweisen. Durch die Immuncytochemie konnte der intrazellulaere Synthese- und Sekretionsweg von Vg ueber das rER und den Golgi-Apparat dargestellt werden. Am Beispiel des Zebrabaerblings war die endokrine Wirkung von Nonylphenol (NP), Octylphenol (OP) und Dehydroepiandrosteron (DHEA) auf Fische nachweisbar. Die Untersuchung ausgewaehlter entwicklungs-biologischer, reproduktionsbiologischer, anatomischer, histologischer und ultrastruktureller Parameter ermoeglichte eine Bewertung schadstoffbedingter Veraenderungen waehrend der Larval-, Juvenil- und Adultphase der Tiere. Die lebenslange Belastung der Zebrabaerblings-Populationen mit NP, OP und DHEA fuehrte grundsaetzlich zu einer deutlichen Verschiebung des Geschlechterverhaeltnisses in Richtung der weiblichen Fische. Nach Abschluss der Exposition der Zebrabaerblinge im Durchflusssystem waren, induziert durch NP, OP und DHEA, weitreichende konditionelle und strukturelle Veraenderungen der Reproduktionsorgane, des Skeletts und der Leber dokumentierbar. Es konnte nachgewiesen werden, dass toxische Wirkungen von NP, OP und DHEA bereits nach einwoechiger Belastung waehrend der Embryonal- und Larvalphase erkannt werden koennen, waehrend sich estrogene Wirkungen auf den Zebrabaerbling, erst nach Exposition ueber den gesamten Lebenszyklus zeigen.SIGLEAvailable from: http://www.ub.uni-heidelberg.de/archiv/1446 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman