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.
Durch die kontinuierliche Zunahme der Sedimente in den Stauraeumen von Flusskraftwerken ergeben sich in zunehmendem Masse Schwierigkeiten hinsichtlich der Auflandung mit Geschiebe- und Schwebstoffmaterial. Ziel des vorliegenden Projektes ist eine exakte sedimentologische und geochemische Charakterisierung der Feinsedimente in den Stauraeumen. Dazu sollen Gesteinsbohrkerne aus den Stauraum-Ablagerungen und Schwebstoffe aus den Zubringern der Drau bzw. aus bestimmten Abschnitten der Drau selbst analysiert werden. Aus der Zusammensetzung der Ablagerungsprodukte koennen Beziehungen zum jeweiligen geologischen Einzugsgebiet sowie zu den Verwitterungsprodukten und Bodenbildung hergestellt werden. Durch tonmineralogische und geochemische Analysen bzw. rasterelektonenmikroskopische Untersuchungen des Mikrogefueges koennen Mineralum- und Neubildungen erfasst werden. Erst nach genauer Kenntnis der mineralogischen und chemischen Zusammensetzung der angelandeten Schwebstoffe koennte auch an eine eventuelle Weiterverwertung als mineralische Rohstoffe gedacht werden.
Amtlicher Stadtplan der Seestadt Bremerhaven, Maßstab 1:15000. Darstellung in grau. Diese Karte ist ein Hybriddatensatz aus verschiedenen Datenbeständen. Kerndatensatz ist ATKIS. Die Aktualität der anderen Daten ist dem entsprechenden Metadatensatz zu entnehmen.
Stadtplan in grau mit Basisbeschriftung.Ohne POI's.
Das Archaikum (3.8 - 2.5 Ga) ist ein geologisches Zeitalter, das große Umwälzungen in der Entwicklung der habitablen Erde mit sich brachte. Die Atmosphäre veränderte sich drastisch: Um das Paradoxon der schwachen jungen Sonne am Beginn des Archaikums zu erklären, braucht es große Mengen an Treibhausgas. Am Ende enthielt die Atmosphäre etwa das heutige Niveau an Treibhausgas und begann freien Sauerstoff anzusammeln. Desweiteren änderte sich die Geologie drastisch: Plattentektonik setzte warscheinlich während des Archaikums ein und beinflußte Atmosphärenzusammensetzung durch einen frühen Kohlenstoff-Zyklus. Die erste kontinentale Kruste, die bis heute überdauert hat, entstand und wuchs während des Archaikums. Die freigelegte Kontinentalkruste beeinflusste Atmosphärenzusammensetzung z.B. indem es eine Senke für Kohlendioxid und Sauerstoff durch Verwitterungsprozesse darstellte. Wir werden in diesem Projekt erstmals ein 3D/1D Klima- und ein 2D Mantelkonvektions-Modell nach dem neusten Stand der Technik koppeln, um Eigenschaften der Atmosphäre (Ausmaß und Zusammensetzung), Oberflächentemperaturen und verschiedene Einsetz-Zeiten für Plattentektonik während des Archaikums zu untersuchen. Wir werden das Paradoxon der jungen schwachen Sonne und die gekoppelte Entwicklung der archaischen Atmosphäre und Geodynamik vom frühen bis späten Archaikum untersuchen und dabei neuen Kontext für die Interpretation geologischer und geochemischer Daten liefern. Das Modell wird rigorose und physikalisch motivierte Randbedingungen beinhalten, die aus geologischen und geochemischen Belegen für Ausgasungs-Raten, Ozeantemperaturen, archaische Atmosphärenzusammensetzung, Beginn der Plattentektonik und Kontinentalwachstum während des Archaikums durch Kollaboration im Projekt 'Building a Habitable Earth' gewonnen wurden.
The Antarctic irwertebrate fauna appears highiy diverse, but is only localiy and sporadically explored - and already threatened by global climate change. Gastropods are abundant, species rieh, ecologically and economically irnportant, count with a rieh fossil record and are wellestablished äs model organisms for many scientific disciplines. Most of the roughly 600 Antarctic gastropod species are regarded valid at the mornent based on shell features of often just a few or single specimens. Intraspecific morphological variability, soft pari anatomy, biology' and ecology are usually unknown, and many synonyms have been proposed. Wolecular data are limited to CÖI barcode sequences of few individuals of the more common species: Phylogenetic analyses of single genes suggest complexes of cryptic species or deep lineages, which may show distinct geographic distributions and special ecological niches. Rarity of species or samples prohibits general population genetics approaches. The prirnary goal of our herein proposed project is revealing the species diversity of Antarctic gastropods comprehensively and reliably. In addition to mltochondrial CÖI, we will use next generation sequencing (NGS) and newly established methods (double digest Restriction Associated DMA sequencing, ddRADseq) to efficiently generate a multitude of independent nuclear genomic sequence markers. We will include all species and subsamples from rnore than 2000 Southern Öcean gastropod samples available at the ZSM Mollusca collection suitable for genetic studies, plus further material to be collected at expeditions or from other museums. We will perform phylogenetic analyses (ML, Bayes, in subgroups BEST) and combined, up to-date molecular species delimitation approaches (ABGD, GMYCS BP&P), An integrative taxonomic approach reiying on congruence will be applied to revea! conservative and reliable evolutionary species units, which will be used for diversity analyses, We will also explore genomic evolutionary archives of seiected gastropod lineages performing fossil-calibrated BEAST chronograms. The dynamics of diversification will be analyzed via recent Birth-Death-Shift models, and historical biogeography will be reconstructed using recent Software (e.g, RASP). With our massif genomic data from many subtaxa we will test current paradigms on biogeography and evolution, such äs glacial cycles causing an 'Antarctic speciation pump', and evaluate competing hypotheses on glacial refuges and migration scenarios. The herein proposed combination of ddRADseqs with up to date multi-iocus analyses is novel, extremely cost and time effective, and can include thousands instead of few specimens' without any a priori selectron. It is expected to be very powerful to delimitate newty collected, unrecognized, or cryptic species, even jf badly sampled or just represented by singletons...
Current and future global warming will cause the degradation of mountain permafrost, which may strongly influence the stability of permafrost slopes or rock walls with potentially hazardous consequences. Due to the strong heterogeneity of both the thermal regime and the ground composition of mountain permafrost, its response to atmospheric forcing can however be highly variable for different landforms and within short distances. The spatial distribution of ice and liquid water is important for determining the sensitivity of a specific permafrost occurrence to climate change because of their large influence on the pace of temperature changes (by effects of latent heat) and their importance for geotechnical properties of the ground. Detailed knowledge of the material properties and internal structures of frozen ground is therefore an important prerequisite to determine the sensitivity of permafrost to climate change. Except for the active layer ice and water contents and their temporal and spatial variability usually cannot be measured directly. Geophysical methods are sensitive for the ice and liquid water content in the ground. With the proposed collaboration, two similar but complementary approaches to quantify the composition of the ground based on 2D sections of geophysical data will be combined for an improved determination of ice and water contents in permafrost regions. The so-called 4-phase model (4PM) is based on two simple petrophysical relationships for electrical resistivity and seismic velocity and estimates volumetric fractions of ice, water, and air within the pore volume of a rock matrix by jointly using complementary data sets from electric and seismic measurements. Due to inherent ambiguities in the model it is still restricted to specific cases and often allows only a rough estimation of the phase fractions. Major drawbacks of the current 4PM comprise the unsatisfactory discrimination between rock and ice and its under-determinedness, requiring the prescription of the porosity and further parameters. The so-called RSANN model (developed and used by the host institution) uses the technique of simulated annealing (a Monte-Carlo-type stochastic simulation approach) as an optimization tool for the integration of electrical resistivity and P-wave velocity to derive 2D sections of porosity, water saturation and volumetric water content. The simulated annealing technique allows - due to its iterative procedure - more parameters to be predicted instead of being prescribed as in the 4PM. The objective of the proposed collaboration is to combine the advantages of the two algorithms (4PM and RSANN) to overcome the shortcomings of the 4PM in order to improve the reliability of the determined ice and liquid water contents. (...)
In the Southern Ocean, eddy-driven transports can be as large as mean transports. In particular the meridional, cross frontal transports are affected or even controlled by meso-scale eddy activity. On the other hand, these transports set the role of the Southern Ocean as a major oceanic sink in the global carbon cycle. In ocean models, such variability has to be adequately resolved or parameterised. The parameterisation by Gent and McWilliams (1990) is currently used to account for such eddy-driven transports, in which the so-called thickness diffusivity K has to be specified. Only a rough order of I magnitude is currently known for ', but, in particular in the Southern Ocean, the choice of K strongly affects meridional transports of mass and tracers and is therefore of crucial importance to quantify the role of the Southern Ocean in the climate system and the global carbon cycle. It is proposed to estimate the thickness diffusivity K in the Southern Ocean from synthetic data of an existing realistic eddy-resolving ocean model. While previous attempts highlight the problem of rotational eddy fluxes which complicate the estimation procedure, it has been recently shown that the definition and use of physically meaningful rotational fluxes reduces this problem. Therefore, reliable estimates of K in the Southern Ocean appear possible for the first time. Furthermore, it is proposed to estimate relations between mean quantities predicted by ocean models and thickness diffusivity, necessary in order to build a self-consistent eddy parameterisation.
Das Projekt soll den Einfluss von Schwallbetrieb auf Fischbestände untersuchen. Dabei gilt es, am Beispiel der Oberen Drau, die kausalen Zusammenhänge zwischen Schwall-/Sunkereignissen und den Entwicklungsschritten juveniler Äschen so genau wie möglich zu erfassen. Erst wenn die tatsächlichen Ursache-Wirkungszusammenhänge zwischen Schwall/Sunk und der Entwicklungsbiologie der Zielfischart Äsche ausreichend bekannt sind, können zielführende Maßnahmen zur Milderung potentieller negativer Einflüsse von Schwallbetrieb entwickelt werden. Entsprechende Forschungsgrundlagen fehlen bisher bzw. sind auch international nicht verfügbar.
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