Experimental Investigation of Gully Formation Under Low Pressure and Low Temperature Conditions

International audienceIntroduction: A large morphological diversity of gullies is observed on Earth and on Mars. Debris flow – a non-newtonian flow comprising a sediment-water mix – is a common process attributed to gully formation on both planets [1, 2]. Many variables can influence the morphology of debris flows (grainsizes, discharge , slope, soil moisture, etc) and their respective influences are difficult to disentangle in the field. Furthermore effects specific to the martian environment have not yet been explored in detail. Some preliminary laboratory simulations have already been performed that isolate some of these variables. Cold room experiments [3] were already perfomed to test the effect of a melted surface layer on the formation of linear gullies over sand dunes. Low pressure experiments [4] were performed to test the effect of the atmospheric pressure on erosional capacity and runout distance of the flows. Our aim is to develop a new set of experiments both under Martian atmospheric pressure and terrestrial atmospheric pressure in order to reproduce the variability of the observed morphologies under well constrained experimental conditions

Orientation and distribution of recent gullies in the southern hemisphere of Mars: observations from HRSC/MEX and MOC/MGS data

Abstract not available

Risk mapping for HPAI H5N1 in Africa - Improving surveillance for virulent bird flu: Final report and maps

More than 85 percent of households in rural Africa raise poultry for food, income, or both, and many people live in close contact with their birds. The possibility of an epidemic of highly pathogenic avian influenza (HPAI) H5N1 is therefore a major concern. Since 2006 bird fl u has been introduced into at least 11 countries in Africa, and over 600 outbreaks reported. Vigilance is key to limiting the disease but animal health personnel cannot monitor everywhere at once. This risk-mapping project was designed to help prioritize their efforts by showing in which places outbreaks are more likely to occur. A risk map is a complex, computer-generated image that shows the spatial distribution of the predicted risk of a disease. It is based on the spatial distribution of “risk factors” associated with an increased risk of disease, and the relative importance of each of these factors. In the case of virulent bird fl u, risk factors include major transport routes, markets where poultry may be traded, and wetlands with the possibility of contact between poultry and wild birds. Researchers in this project have prepared risk maps for bird fl u in Africa using multi-criteria decision modeling (MCDM). In this way they have integrated data and information from such diverse sources as published scientific literature, maps available in the public domain, field surveys and expert consultations

Amélioration de la surveillance de l’influenza aviaire de type H5N1 - Cartographie du risque d’influenza aviaire de type H5N1 en Afrique: Rapport final et cartes de risqué d’influenza aviaire

Plus de 85% des ménages ruraux en Afrique élèvent la volaille aux fins d’alimentation, de revenu ou les deux, et de nombreuses personnes vivent en contact étroit avec leurs oiseaux. La possibilité d’une épidémie de l’influenza aviaire hautement pathogène (IAHP) de type H5N1 est donc une grande préoccupation. Depuis 2006, la grippe aviaire est apparue dans au moins 11 pays africains et plus de 600 foyers d’épidémie ont été signalés. La vigilance est essentielle en vue de limiter la maladie mais le personnel de santé animale ne peut faire un suivi partout à la fois. Ce projet de cartographie de facteurs de risques a été conçu en vue d’aider à prioriser leurs efforts en indiquant les lieux où il existe un risque très élevé de flambées de la maladie. La cartographie des risques est une image complexe générée par ordinateur qui montre la répartition spatiale des facteurs de risques prévus d’une maladie. Elle est fondée sur la répartition spatiale des « facteurs de risques » associés au risque accru de maladie et à l’importance relative de chacun de ces facteurs. Dans le cas d’une grippe aviaire de type H5N1, les facteurs de risques sont les principales voies de transport, les marchés de volailles et les points d’eau avec possibilité de contact entre les oiseaux domestiques et sauvages. Pour ce projet, les chercheurs ont préparé des cartes de risques de grippe aviaire en Afrique en utilisant la modélisation de décision multicritères (MCDM). De cette façon, ils ont intégré les données et les informations de diverses sources telles que les publications scientifi ques, les cartes disponibles dans le domaine public, les études de terrain et les consultations d’expert

Attitudes and Beliefs of Pig Farmers and Wild Boar Hunters Towards Reporting of African Swine Fever in Bulgaria, Germany and the Western Part of the Russian Federation

This study investigated the attitudes and beliefs of pig farmers and hunters in Germany, Bulgaria and the western part of the Russian Federation towards reporting suspected cases of African swine fever (ASF). Data were collected using a web-based questionnaire survey targeting pig farmers and hunters in these three study areas. Separate multivariable logistic regression models identified key variables associated with each of the three binary outcome variables whether or not farmers would immediately report suspected cases of ASF, whether or not hunters would submit samples from hunted wild boar for diagnostic testing and whether or not hunters would report wild boar carcasses. The results showed that farmers who would not immediately report suspected cases of ASF are more likely to believe that their reputation in the local community would be adversely affected if they were to report it, that they can control the outbreak themselves without the involvement of veterinary services and that laboratory confirmation would take too long. The modelling also indicated that hunters who did not usually submit samples of their harvested wild boar for ASF diagnosis, and hunters who did not report wild boar carcasses are more likely to justify their behaviour through a lack of awareness of the possibility of reporting. These findings emphasize the need to develop more effective communication strategies targeted at pig farmers and hunters about the disease, its epidemiology, consequences and control methods, to increase the likelihood of early reporting, especially in the Russian Federation where the virus circulate

Mars Analog Site Study (MASS)

Many proposed missions to Mars involve landing vehicles, including the Mars 94/96 (Russia), Mars Environmental Survey (MESUR, US), and the Marsnet (ESA) missions. Most landers involve in situ measurements of rock and soil compositions, study of local geology by imaging, and establishment of seismic and meteorological networks. The selection of landing sites on Mars is a complex process that must meet engineering constraints and scientific objectives, using available and anticipated data. The goal of the MASS project is to conduct an 'end-to-end' test of the site selection process using Earth analogs

Gridmapping the northern plains of Mars: Geomorphological, Radar and Water-Equivalent Hydrogen results from Arcadia Plantia

A project of mapping ice-related landforms was undertaken to understand the role of sub-surface ice in the northern plains. This work is the first continuous regional mapping from CTX (“ConTeXt Camera”, 6 m/pixel; Malin et al., 2007) imagery in Arcadia Planitia along a strip 300 km across stretching from 30°N to 80°N centred on the 170° West line of longitude. The distribution and morphotypes of these landforms were used to understand the permafrost cryolithology. The mantled and textured signatures occur almost ubiquitously between 35° N and 78° N and have a positive spatial correlation with inferred ice stability based on thermal modelling, neutron spectroscopy and radar data. The degradational features into the LDM (Latitude Dependent Mantle) include pits, scallops and 100 m polygons and provide supporting evidence for sub-surface ice and volatile loss between 35-70° N in Arcadia with the mantle between 70-78° N appearing much more intact. Pitted terrain appears to be much more pervasive in Arcadia than in Acidalia and Utopia suggesting that the Arcadia study area had more wide-spread near-surface sub-surface ice, and thus was more susceptible to pitting, or that the ice was less well-buried by sediments. Correlations with ice stability models suggest that lack of pits north of 65-70° N could indicate a relatively young age (~1Ma), however this could also be explained through regional variations in degradation rates. The deposition of the LDM is consistent with an airfall hypothesis however there appears to be substantial evidence for fluvial processes in southern Arcadia with older, underlying processes being equally dominant with the LDM and degradation thereof in shaping the landscape