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

Pyoderma outbreak among kindergarten families: Association with a Panton-Valentine leukocidin (PVL)-producing S. aureus strain

Objectives: We report on an outbreak of skin and soft tissue infections (SSTI) among kindergarten families. We analyzed the transmission route and aimed to control the outbreak. Methods: The transmission route was investigated by nasal screening for Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus (PVL-SA), subsequent microbiological investigation including whole genome sequencing and a questionnaire-based analysis of epidemiological information. The control measures included distribution of outbreak information to all individuals at risk and implementation of a Staphylococcus aureus decontamination protocol. Results: Individuals from 7 of 19 families were either colonized or showed signs of SSTI such as massive abscesses or eye lid infections. We found 10 PVL-SA isolates in 9 individuals. In the WGS-analysis all isolates were found identical with a maximum of 17 allele difference. The clones were methicillin-susceptible but cotrimoxazole resistant. In comparison to PVL-SAs from an international strain collection, the outbreak clone showed close genetical relatedness to PVL-SAs from a non-European country. The questionnaire results showed frequent travels of one family to this area. The results also demonstrated likely transmission via direct contact between families. After initiation of Staphylococcus aureus decontamination no further case was detected. Conclusions: Our outbreak investigation showed the introduction of a PVL-SA strain into a kindergarten likely as a result of international travel and further transmission by direct contact. The implementation of a Staphylococcus aureus decontamination protocol was able to control the outbreak

Insights into Highland Patera Volcanism using Mars Express HRSC Data

We have used images obtained by the High Resolution Stereo Camera (HRSC) on the ESA Mars Express orbiter to assess geologic activity at two of Mars' highland volcanoes: Hadriaca Patera and Tyrrhena Patera. HRSC images cover wide swaths at consistent lighting conditions and resolutions, making them ideal resources for assessing surfaces ages using crater statistics. Additionally, multi-channel HRSC images are processed to produce Digital Terrain Models (DTMs) that are of greater spatial resolution than MOLA-derived DTMs, which are useful to assess regional and local topographic variations. Crater size-frequency analyses and cratering model age estimates show both Hadriaca and Tyrrhena Paterae have complex surfaces shaped by volcanic, fluvial, and eolian processes. These ancient shields were formed early in martian history, 3.7-4.0 Ga. At Hadriaca Patera, the earliest detectable caldera activity occurred at 3.5 Ga, followed by explosive volcanic and fluvial activity on the flanks at 3.3-3.4 Ga. Later caldera activity occurred at 2.2-2.5 Ga and again at 1.1-1.6 Ga. At Tyrrhena Patera, explosive volcanic activity and emplacement of pyroclastic deposits occurred 3.5-3.6 Ga, with later fluvial erosional activity at 1.9-2.0 Ga and again at 1.2-1.5 Ga. Slopes on Tyrrhena Patera are generally shallower (0.09-0.4 degrees) than those on Hadriaca Patera (up to 0.7 degrees). Hadriaca's north flank trends uphill, suggesting that Hadriaca Patera settled due to removal of material during formation of Dao Vallis. Further study is underway to use HRSC topographic data and computer modeling to better understand pyroclastic volcanism at these two volcanoes