2,814 research outputs found

    Amplitude-Driven-Adaptive-Neighbourhood Filtering of High-Resolution Pol-InSAR Information

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    International audienceIn this paper a new method for fltering coherency matrices issued from Synthetic Aperture Radar (SAR) polarimetric interferometric data is presented. For each pixel of the interferogram, an adaptive neighborhood is determined by a region growing technique driven exclusively by the amplitude image information. All the available amplitude images of the interferometric couple are fused in the region growing process to ensure the stationarity hypothesis of the derived statistical population. In addition, for preserving local stationarity requirement of the interferogram, a phase compensation step is performed. Afterwards, all the pixels within the obtained adaptive neighborhood are complex averaged to yield the fltered values of the polarimetric and interferometric coherency matrices. The method has been tested on airborne high-resolution polarimetric interferometric SAR images (Oberpfaffenhofen area - German Space Agency). For comparison purposes, the standard phase compensated fixed multi-look flter and the linear adaptive coherence flter proposed by Lee at al. were also implemented. Both subjective and objective performance analysis, including coherence edge detection, ROC graph and bias reduction tables, recommends the proposed algorithm as a powerful post-processing POL-InSAR tool

    Grossesses extra utérines successives et bilharziose tubaire chez une touriste française

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    La bilharziose est la seconde endémie parasitaire mondiale et ses atteintes génito urinaires sont bien décrites. Les grossesses ectopiques (GEU) sur obstruction tubaire par les oeufs de bilharziose sont rapportées dans les populations africaines. La bilharziose affecte aussi les voyageurs mais l'atteinte de l’appareil génital féminin est plus rare. Nous rapportons un cas exceptionnel de deux GEU successives sur bilharziose tubaire chez une patiente d'origine Française, sept ans après un voyage touristique au Mali, la première découverte sur pièce de salpingectomie et la seconde ayant nécessité une salpingotomie controlatérale avec une injection de  méthotrexate, deux mois plus tard.Key words: Grossesse extra utérine, bilharziose tubaire, tromp

    A first comparison of Cosmo-Skymed and TerraSAR-X data over Chamonix Mont-Blanc test-site

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    International audienceThis paper presents the first results obtained with satellite im- age time series (SITS) acquired by Cosmo-SkyMed (CSK) over the Chamonix Mont-Blanc test-site. A CSK SITS made of 39 images is merged with a TerraSAR-X SITS made of 26 images by using the orbital information and co-registration tools developed in the EFIDIR project. The results are illus- trated by the computation of speckle-free images by temporal averaging, by the generation and comparison of topographic interferograms and by the measure of glacier displacement fields by amplitude correlation

    Organisation territoriale et socio-économique au Néolithique final dans la région du Grand-Pressigny: caractérisation des provenances des matériaux céramiques

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    National audienceIn and around Le Grand-Pressigny (Indre-et-Loire, France), a petrographic study was implementedon 92 ceramic samples from the Final Neolithic sites of Le Petit-Paulmy and Bergeresse (Abilly).Analyses showed that the sediments used were extracted from local sources: Claise and Creusealluvium, local substrate and loessic silts. Quantitatively, the study showed that almost all the ceramicmaterials in Bergeresse and more than half of those in Le Petit-Paulmy come from the valley of theCreuse. The mineralogical compositions of three samples from Le Petit-Paulmy, including one ofunusual form, indicate sources from an exogenous region, the Massif Central (perhaps the alluviumof the Loire or the Allier). These results show the important role played by the valley of the Creusein the territorial organisation of Le Grand-Pressigny. This study therefore makes an originalcontribution to the debate on flint exploitation in this region. These ceramic data are expected to offernew interpretative models concerning the socio-economic organisation of local Neolithic communities.Dans la région du Grand-Pressigny (Indre-et-Loire, France), une étude pétrographique a été conduite sur 92 échantillons céramiques du Néolithique final provenant des sites du Petit-Paulmy et de Bergeresse (Abilly), respectivement situés dans la vallée de la Claise et de la Creuse. Les analyses ont montré que les sédiments utilisés provenaient majoritairement de sources locales, correspondant aux alluvions de la Claise, de la Creuse, au substrat local et à des limons loessiques. Quantitativement, l'étude a montré que presque tous les matériaux céramiques de Bergeresse et plus de la moitié de ceux du Petit-Paulmy proviennent de la vallée de la Creuse. Les compositions minéralogiques de trois échantillons du Petit-Paulmy, dont un concernant une forme particulière, indiquent des provenances exogènes, du Massif central (alluvions de la Loire ou de l'Allier). Ces résultats montrent l'importance du rôle joué par la vallée de la Creuse dans l'organisation territoriale de la région du Grand-Pressigny. L'étude des céramiques apporte une contribution originale dans le débat sur l'organisation socioéconomique de l'exploitation du silex du Grand-Pressigny et devrait permettre de proposer de nouveaux modèles interprétatifs

    Monitoring Alpine Glaciers with ALOS SAR and Optical data

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    International audienceThe monitoring of temperate glacier activity is one of the applications which require the combined use of optical and SAR data. It should become feasible thanks to the ALOS PRISM and PALSAR sensors. In this paper, we present the interest of using L-band polarimetric interferometric SAR data and high resolution panchromatic stereoscopic data to monitor moving temperate glaciers made of ice, snow and rocks. The scientific issues are described and a test-site located in the Mont-Blanc region in the Alps is proposed for specific experiment and validation. The Mont-Blanc test-site includes two well-known glaciers (Mer-de-Glace and Argentière glaciers) where a large data set has been collected: ERS, RADARSAT and ENVISAT data, airborne E-SAR data (X, C, L and P bands), airborne photographs, GPS and GPR in-situ measurements..

    Monitoring temperate glaciers: combined use of multi-date TerraSAR-X images and continous GPS measurements

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    International audienceThis paper highlights the contribution of TerraSAR-X (TSX) High Resolution (HR) images for temperate glacier monitoring. A series of 14 images have been acquired since October 2007 on the Mont-Blanc test area. This area involves well-known temperate glaciers which have been monitored and instrumented ("stick" for annual displacement/ablation, GPS, cavitometer for basal displacement...) for more than 50 years. The combined use of in-situ measurements and multi-temporal images allows to improve the potential of HR SAR measurements. Interpretation of HR images, investigation of interferometric and correlation methods, and the first glacier displacement results are presented

    Poly-phased fluid flow in the giant fossil pockmark of Beauvoisin, SE basin of France

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    The giant Jurassic-aged pockmark field of Beauvoisin developed in a 800 m wide depression for over 3.4 Ma during the Oxfordian; it formed below about 600 m water depth. It is composed of sub-sites organized in clusters and forming vertically stacked carbonate lenses encased in marls . This fine-scale study is focused on a detailed analysis of petrographical organization and geochemical signatures of crystals that grew up in early to late fractures of carbonate lenses, surrounding nodules, and tubes that fed them. The isotopic signature (C, O and Sr) shows that at least three different episodes of fluid migration participated to the mineralization processes. Most of the carbonates precipitated when biogenic seepage was active in the shallow subsurface during the Oxfordian. The second phase occurred relatively soon after burial during early Cretaceous and thermogenic fluids came probably from underlying Pliensbachian, Late Toarcian or Bajocian levels. The third phase is a bitumen-rich fluid probably related to these levels reaching the oil window during Mio-Pliocene. The fluids migrated through faults induced by the emplacement of Triassic-salt diapir of Propiac during the Late Jurassic and that remained polyphased drain structures over time

    Instance nationale et multi-communauté de DIRAC pour France Grilles

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    DIRAC [DIRAC] [TSA-08] is a software framework for building distributed computing systems. It was primarily designed forthe needs of the LHCb [LHCb] Collaboration, and is now used by many other communities within EGI [EGI] as a primary wayof accessing grid resources. In France, dedicated instances of the service have been deployed in different locations toanswer specific needs. Building upon this existing expertise, France Grilles [FG] initiated last year a project to deploy anational, multi-community instance in order to share expertise and provide a consistent high-quality service. After describingDIRAC main aims and functionalities, this paper presents the motivations for such a project, as well as the wholeorganizational and technical process that led to the establishment of a production instance that already serves 13communities: astro.vo.eu-egee.org, biomed, esr, euasia, gilda, glast.org, prod.vo.eu-eela.eu, superbvo.org,vo.formation.idgrilles.fr, vo.france-asia.org, vo.france-grilles.fr, vo.msfg.fr and vo.mcia.fr

    Integrating community-based verbal autopsy into civil registration and vital statistics (CRVS): system-level considerations.

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    BACKGROUND: Reliable and representative cause of death (COD) statistics are essential to inform public health policy, respond to emerging health needs, and document progress towards Sustainable Development Goals. However, less than one-third of deaths worldwide are assigned a cause. Civil registration and vital statistics (CRVS) systems in low- and lower-middle-income countries are failing to provide timely, complete and accurate vital statistics, and it will still be some time before they can provide physician-certified COD for every death. Proposals: Verbal autopsy (VA) is a method to ascertain the probable COD and, although imperfect, it is the best alternative in the absence of medical certification. There is extensive experience with VA in research settings but only a few examples of its use on a large scale. Data collection using electronic questionnaires on mobile devices and computer algorithms to analyse responses and estimate probable COD have increased the potential for VA to be routinely applied in CRVS systems. However, a number of CRVS and health system integration issues should be considered in planning, piloting and implementing a system-wide intervention such as VA. These include addressing the multiplicity of stakeholders and sub-systems involved, integration with existing CRVS work processes and information flows, linking VA results to civil registration records, information technology requirements and data quality assurance. CONCLUSIONS: Integrating VA within CRVS systems is not simply a technical undertaking. It will have profound system-wide effects that should be carefully considered when planning for an effective implementation. This paper identifies and discusses the major system-level issues and emerging practices, provides a planning checklist of system-level considerations and proposes an overview for how VA can be integrated into routine CRVS systems
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