Image equalisation using an external brightness reference

After more than ten years in orbit at Mars, the coverage from the High Resolution Stereo Camera (HRSC) on the European Space Agency’s Mars Express is sufficient to begin constructing mosaic products on a global scale. We describe our systematic processing procedure and, in particular, the technique used to bring images affected by atmospheric dust into visual consistency with the mosaic. We outline how the same method is used to produce a relative colour mosaic which shows local colour differences. We demonstrate the results and show that the techniques may also be applied to images from other orbital cameras

Experimental gas phase H-1 NMR spectra and basis set dependence of ab initio GIAO MO calculations of H-1 and C-13 NMR absolute shieldings and chemical shifts of small hydrocarbons

High-resolution gas phase measurements of H-1 NMR spectra at 400 MHz and atmospheric pressure of seven small hydrocarbons are presented. The developed new method and the experimental set-up are described. Ab initio GIAO MO calculations of H-1 and C-13 NMR absolute shieldings on the HF, MP2 and B3LYP levels using 25 standard gaussian basis sets are reported for these hydrocarbons, based on experimental r(e) distances. The measured gas phase H-1 chemical shifts have been converted to an absolute sigma(0) shielding scale by use of the literature shielding of methane. These and gas phase C-13 literature values have been transferred with literature ZPV data to estimated sigma(e)(exp) shieldings which are used to evaluate the basis set dependence of the calculated a, shieldings utilizing linear least squares regressions. Exponential extrapolations of Dunning basis set calculations allow the determination of basis set limits for H-1 and C-13 shieldings. H-1 and C-13 chemical shifts have been derived from the HF calculated shieldings with shieldings of TMS which has been geometry optimized and GIAO calculated in each basis. Standard deviations, (esd) as low as 0.09 ppm for H-1 and 0.76 ppm for C-13 calculations have been obtained. The statistically best basis set for simultaneous calculation of H-1 and C-13 absolute shieldings or relative shifts is 6-311G* within the HF and B3LYP methods. Aiming for highest accuracy and precision, H-1 and C-13 have to be treated separately. In this case. best results are obtained using MP2/6-311G** or higher for H-1 shieldings and MP2/cc-pVTZ for C-13 shieldings

The proof of the pudding is in the eating: an outbreak of emetic syndrome after a kindergarten excursion, Berlin, Germany, December 2007

An outbreak of food poisoning (emetic syndrome) occurred in three kindergartens (A, B and C) in Berlin, Germany, on 3 December 2007 after an excursion during which food was served. We conducted a retrospective cohort study among the kindergarten children and personnel who participated in the trip. The overall attack rate among the 155 participants was 30%. It was 31% among the 137 children (aged two to six years) and 17% among adults (n=18). The consumption of rice pudding was significantly associated with disease. Among those who ate rice pudding, the attack rate was 36%, compared with 0% for non-eaters (relative risk: infinite,

Evidence of Late-Stage Fluvial Outflow in Echus Chasma, Mars

International audienc

Amazonian geologic history of the Echus Chasma and Kasei Valles system on Mars: New data and interpretations

International audienc

Systematic processing of Mars Express HRSC panchromatic and colour image mosaics: Image equalisation using an external brightness reference

After more than ten years in orbit at Mars, the coverage from the High Resolution Stereo Camera (HRSC) on the European Space Agency’s Mars Express is sufficient to begin constructing mosaic products on a global scale. We describe our systematic processing procedure and, in particular, the technique used to bring images affected by atmospheric dust into visual consistency with the mosaic. We outline how the same method is used to produce a relative colour mosaic which shows local colour differences. We demonstrate the results and show that the techniques may also be applied to images from other orbital cameras