Organotin and especially butyltin compounds are used for a variety of applications, e.g. as biocides, stabilizers, catalysts and intermediates in chemical syntheses. Tributyltin (TBT) compounds exhibit the greatest toxicity of all organotins and have even been characterized as one of the most toxic groups of xenobiotics ever produced and deliberately introduced into the environment. TBT is not only used as an active biocidal compound in antifouling paints, which are designed to prevent marine and freshwater biota from settlement on ship hulls, harbour and offshore installations, but also as a biocide in wood preservatives, textiles, dispersion paints and agricultural pesticides. Additionally, it occurs as a by-product of mono- (MBT) and dibutyltin (DBT) compounds, which are used as UV stabilizer in many plastics and for other applications. Triphenyltin (TPT) compounds are also used as the active biocide in antifouling paints outside Europe and furthermore as an agricultural fungicide since the early 1960s to combat a range of fungal diseases in various crops, particularly potato blight, leaf spot and powdery mildew on sugar beet, peanuts and celery, other fungi on hop, brown rust on beans, grey moulds on onions, rice blast and coffee leaf rust. Although the use of TBT and TPT was regulated in many countries world-wide from restrictions for certain applications to a total ban, these compounds are still present in the environment. In the early 1970s the impact of TBT on nontarget organisms became apparent. Among the broad variety of malformations caused by TBT in aquatic animals, molluscs have been found to be an extremely sensitive group of invertebrates and no other pathological condition produced by TBT at relative low concentrations rivals that of the imposex phenomenon in prosobranch gastropods speaking in terms of sensitivity. TBT induces imposex in marine prosobranchs at concentrations as low as 0,5 ng TBT-Sn/L. Since 1993, for the littorinid snail Littorina littorea a second virilisation phenomenon, termed intersex, is known. In female specimens affected by intersex the pallial oviduct is transformed of towards a male morphology with a final supplanting of female organs by the corresponding male formations. Imposex and intersex are morphological alterations caused by a chronic exposure to ultra-trace concentrations of TBT. A biological effect monitoring offers the possibility to determine the degree of contamination with organotin compounds in the aquatic environment and especially in coastal waters without using any expensive analytical methods. Furthermore, the biological effect monitoring allows an assessment of the existing TBT pollution on the basis of biological effects. Such results are normally more relevant for the ecosystem than pure analytical data. usw.
In forest ecosystems ectomycorrhizal fungi are responsible for the mobilization of mineral nutrients from soil organic matter (SOM) resulting in a marked increase in productivity of their symbiotic host plants. In return the fungi obtain a significant amount of photosynthetic products from these plants, allowing the formation of an extensive hyphal system. These hyphae constitute a major part of soil biomass and, ultimately, a major source for SOM formation. While plant-fungal nutrient exchange has been analyzed extensively, this proposal is focused on the fungal contribution to SOM formation and on the processes leading to the acquisition of nutrients by the fungi. These two processes will be studied separately and in a quantitative way using isotopic labeling in soil bioreactors. Analysis of the fate of 13C labeled fungal material (Laccaria bicolor) in soil bioreactors will tell how fast and to what extent the various fractions of hyphal biomass are transformed into non-living SOM. As potential molecular or structural markers for SOM formation from fungal hyphae we will analyze characteristic remnants of fungal hyphae in SOM using scanning electron microscopy, DNAfragments using a PCR approach for the fungal rRNA internal transcribed spacerregions and biochemical markers like fatty acids and ergosterol. The impact of ectomycorrhizal mycelia supported by Pinus sylvestris plantlets on 13C- and 15N-labeled SOM and on microbial biomass will be analyzed in separate soil bioreactor experiments.
Der Kartendienst stellt die Standorte der öffentlichen Landesverwaltung und der Kommunen dar.:Standorte der Schulen im Saarland, erfasst wurden allgemeinbildende Schulen, Berufsschulen, Binationale Schulen und Hochschulen (Quelle: Bildungsserver bzw. Statistisches Landesamt des Saarlandes, Stand 05/2025).
Der Kartendienst stellt die Standorte der öffentlichen Landesverwaltung und der Kommunen dar.:Staatliche anerkannte Einrichtungen und Landesorganisationen der allgemeinen und politischen Weiterbildung im Saarland (Quelle: Ministerium für Bildung und Kultur des Saarlandes, Stand September 2014). Erfasst wurden die Kategorien Kreisvolkshochschule, Volkshochschule, Kath.Erwachsenenbildung, Ev. Erwachsenenbildung, Ev. Familienbildung, Kath. Familienbildung, Christliche Familienbildung, Bildungswerk, Ev. Akademie, Landfrauen, Europäische Akademie und den Landesorganisationen (Stand 05/2022).
In dem Kartendienst (WMS-Dienst) werden Schulen und Kitas im Saarland dargestellt, in denen Obst verteilt wird.:Standorte der Schulen im Saarland, die am Schulobstprogramm teilnehmen.
Private und staatliche Schulen im Landkreis Lüchow-Dannenberg. Alle Schulen die im Lankreis sind mit Schülerzahlen (11.05.2017) Lehrerzahlen, Adresse, Flurdaten, Kontaktadressen von Rektor, Sekretariat und Hausmeister.Verlinkte Dokumente Fluchtpläne Rettungswege und tw. LagekarteDatenstrruktur wurde an das Datenmodell der MRH angepasst (Feldnamen, Felder). Pflichtfelder der MRH wurden übernommen, optionale Felder nur teilweise. Die Daten haben den Geometrietyp Punkt (33).
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