Disk evolution, element abundances and cloud properties of young gas giant planets.

We discuss the chemical pre-conditions for planet formation, in terms of gas and ice abundances in a protoplanetary disk, as function of time and position, and the resulting chemical composition and cloud properties in the atmosphere when young gas giant planets form, in particular discussing the effects of unusual, non-solar carbon and oxygen abundances. Large deviations between the abundances of the host star and its gas giants seem likely to occur if the planet formation follows the core-accretion scenario. These deviations stem from the separate evolution of gas and dust in the disk, where the dust forms the planet cores, followed by the final run-away accretion of the left-over gas.

Tracing the physical conditions in active galactic nuclei with time-dependent chemistry.

We present an extension of the code ProDiMo that allows for a modeling of processes pertinent to active galactic nuclei and to an ambient chemistry that is time dependent. We present a proof-of-concept and focus on a few astrophysically relevant species, e.g.

An international intercomparison exercise for the determination of purified microcystin-LR and microcystins in cyanobacterial field material.

The comparability of current microcystin analysis methods has been evaluated in an international intercomparison exercise. The focus was on the analysis of microcystins by high-performance liquid chromatography coupled with ultraviolet or photodiode-array detection (HPLC-PDA/UV), currently the most widespread method for microcystin analysis, but the exercise was open for other methods such as enzyme-linked immunosorbent assay (ELISA), protein phosphatase inhibition assay (PPA) and high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS).Thirty-one laboratories from 13 countries participated in the study.