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

Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations

Abstract Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline

Variability of spider spatial configuration at the Martian south pole

Araneiform terrain, or “spider” (spider-like surface modifications) is suggested to form through basal sublimation of seasonal translucent CO2 slab ice and subsequent gas jetting, and so far only known to occur at the Martian south pole. Their spatial configuration characteristics remain incompletely understood. We observed non-random spatial distributions in seven study regions with significant regional variation of average spacings. This non-randomness results from the pressure release by jetting from one spider, inhibiting ice rupture in the vicinity to initiate a new spider. Rose diagrams constructed from our trough orientation mapping show that spider troughs do not have preferred orientations and appear randomly distributed. We suggest that substrate properties such as permeability, porosity and cohesion regulate and modify the spatial configuration of a spider population on a regional scale, and insolation and obliquity determine whether general conditions are favorable for spider formation. The limited areal distribution of spiders may be due to the strict formation constraints on the thickness of the seasonal translucent CO2 slab ice. This work provides insight into the regional variability of gas jetting and spider formation

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