A Natural Seismic Isolating System: The Buried Mangrove Effects

The Belleplaine test site, located in the island of Guadeloupe (French Lesser Antilles) includes a three-accelerometer vertical array, designed for liquefac- tion studies. The seismic response of the soil column at the test site is computed using three methods: the spectral ratio method using the vertical array data, a numerical method using the geotechnical properties of the soil column, and an operative fre- quency domain decomposition (FDD) modal analysis method. The Belleplaine test site is characterized by a mangrove layer overlaid by a stiff sandy deposit. This con- figuration is widely found at the border coast of the Caribbean region, which is exposed to high seismic hazard. We show that the buried mangrove layer plays the role of an isolation system equivalent to those usually employed in earthquake engineering aimed at reducing the seismic shear forces by reducing the internal stress within the structure. In our case, the flexibility of the mangrove layer reduces the distortion and the stress in the sandy upper layer, and consequently reduces the potential of liquefaction of the site

From high throughput 454 GS FLX data analysis process of 16S RNA gene sequences using barcoding to bacterial community exploration

From high throughput 454 GS FLX data analysis process of 16S RNA gene sequences using barcoding to bacterial community exploratio

The ruminal level of trans-10 fatty acids of dairy cows is linked to the composition of bacterial community

The ruminal level of trans-10 fatty acids of dairy cows is linked to the composition of bacterial communit

Changes in antioxidant enzymes during sunflower seed development

International audienc

Optimisation and realisation of a portable NMR apparatus and Micro Antenna for NMR

International audienceThis paper is focused on two designs and realizations. The first one concerns a prototype of a portable NMR (nuclear magnetic resonance) apparatus. The second one concerns NMR micro antenna realization. For the first part, our goal is the NMR magnetic field homogeneity and the signal-to-noise ratio (SNR) improvement. Since de the volume of the sample to analyse is around 1 cm 3 , the design is optimized to obtain a good SNR. Particularly, the magnet is chosen to obtain a high magnetic field with limited inhomogeneities. The receiver antenna is designed and optimized to have high feeling factor and then more sensitivity. A mixer and a low-pass filter are used in order to limit the bandwidth and reduce the thermal noise. The FID is digitized and addressed to a FPGA which averages successive acquisitions in order to increase the SNR. The final acquisition is processed for determining the FID spectrum. In the second part, a new concept of micro coil is presented in order to measure the small volumes and small concentrations samples by NMR spectroscopy at 4.7 T (200 MHz proton frequency resonance). This micro sensor would offer the possibility of new investigation techniques based on micro coils' implantation used for in vivo study of local cerebral metabolites of animals models

Modelling crisis management for improved action and preparedness (CRISMA): Modelling submersion on the Charente-Maritime coast

International audienceCRISMA is a Research and Development project financed by the European Community. Its objective is to develop a simulation-based decision support system, in different domains of the natural or industrial risk (flood, snowstorm, seism, forest fires, accidental pollution, urban accidents). The application in France, coordinated by ARTELIA Eau & Environnement, is devoted to the submersion risk on the Charente-Maritime coast and based on the experience feedback of the storm Xynthia in February, 2010. In this framework, a specific work is in progress through a thesis realized in collaboration between ARTELIA and lNRIA. Its objective is to elaborate a methodology of multi-model coupling which should be effective and applicable for the CRISMA project. These models may differ in several ways, related either to the physics and/or to the numeric concepts. The developed methodology may allow to taking into account more specific areas (urban zone, bridge in charge, …), but also should be able to simplify the simulation by dimension changes of model parts (for example, a 1D model for rivers, and a 2D one for sea). The present work addresses more specifically the problem of coupling models with different spatial dimensions

Coupling 3D Navier-Stokes and 1D shallow water models

International audienceThe present work addresses the problem of coupling hydrodynamical models with different spatial dimensions, which can be used in order to reduce the computational cost of river numerical models. We show that this problem can be tackled quite efficiently by designing a simple algorithm using techniques borrowed from domain decomposition theory. This algorithm is non intrusive, i.e. allows using existing numerical models with very few modifications. The method is illustrated on an academic test-case, namely a free surface flow in a bend-shaped channel. A 3-D Navier-Stokes model is coupled with a 1-D shallow water model, and results are compared to those obtained in a fully 3-D case. It is shown that the coupling algorithm provides an accurate solution, which can be improved thanks to an iterative algorithm (Schwarz method). This study is performed using the Mascaret-Telemac system

Vélocimétrie par scan 3D d'écoulements turbulents : application à un écoulement à surface libre sur fond poreux

International audienceCet article présente une méthode de mesure utilisant deux techniques laser connues : le scan par adaptation d’indice de réfraction (RIMS) et la vélocimétrie par images de particules (PIV). Le couplage de ces deux techniques permet de mesurer finement les vitesses locales du fluide dans un milieu granulaire saturé. Dans notre cas, nous étudions l’écoulement d’un fluide à surface libre sur un milieu granulaire. Le fluide iso-indice utilisé a des propriétés proches de celles de l’eau et le lit granulaire est formé de billes de verre. C’est une configuration qui s’approche de l’objet d’étude dans notre laboratoire : les torrents de montagne. La spécificité de cette technique est la mesure en continu des vitesses du fluide tandis que la nappe laser se déplace dans la direction perpendiculaire à l’écoulement. Nous utilisons la méthode des doubles moyennes pour déduire les grandeurs d’intérêt telles que la contrainte turbulente ou la contrainte induite par la forme du lit. Nos résultats expérimentaux montrent la robustesse et la répétabilité de cette technique pour étudier le mélange dans les trois dimensions spatiales

Genoscape: a Cytoscape plug-in to automate the retrieval and integration of gene expression data and molecular networks

Summary: Genoscape is an open-source Cytoscape plug-in that visually integrates gene expression data sets from GenoScript, a transcriptomic database, and KEGG pathways into Cytoscape networks. The generated visualisation highlights gene expression changes and their statistical significance. The plug-in also allows one to browse GenoScript or import transcriptomic data from other sources through tab-separated text files. Genoscape has been successfully used by researchers to investigate the results of gene expression profiling experiments