Ueber die Mittel, die Gegenwart der schwefligen Säure in Producten des Handels zu erkennen

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Potential of Electrical Resistivity Tomography to Detect Fault Zones in Limestone and Argillaceous Formations in the Experimental Platform of Tournemire, France

International audienceThe Experimental platform of Tournemire (Aveyron, France) developed by IRSN (French Institute for Radiological Protection and Nuclear Safety) is located in a tunnel excavated in a clay-rock formation interbedded between two limestone formations. A well-identified regional fault crosscuts this subhorizontal sedimentary succession, and a subvertical secondary fault zone is intercepted in the clay-rock by drifts and boreholes in the tunnel at a depth of about 250 m. A 2D electrical resistivity survey was carried out along a 2.5 km baseline, and a takeout of 40 m was used to assess the potential of this method to detect faults from the ground surface. In the 300 m-thick zone investigated by the survey, electrical resistivity images reveal several subvertical low-resistivity discontinuities. One of these discontinuities corresponds to the position of the Cernon fault, a major regional fault. One of the subvertical conductive discontinuities crossing the upper limestone formation is consistent with the prolongation towards the ground surface of the secondary fault zone identified in the clay-rock formation from the tunnel. Moreover, this secondary fault zone corresponds to the upward prolongation of a subvertical fault identified in the lower limestone using a 3D high-resolution seismic reflection survey. This type of large-scale electrical resistivity survey is therefore a useful tool for identifying faults in superficial layers from the ground surface and is complementary to 3D seismic reflection surveys

Genetic and functional analyses of krs, a locus encoding kurstakin, a lipopeptide produced by Bacillus thuringiensis

Bacteria of the Bacillus genus are able to synthesize several families of lipopeptides. These small molecules are the product of non-ribosomal peptide synthetases. In 2000, it was found that Bacillus thuringiensis, an entomopathogenic bacterium of the Bacillus cereus group, produced a previously unknown lipopeptide: kurstakin. Genomic analyses reveal that the krs locus, encoding the kurstakin synthetases, is specific to the B. cereus group, but is unevenly distributed within this group. Previous work showed that krs transcription requires the necrotrophism quorum-sensor NprR. Here, we demonstrated that the genes of the krs locus form an operon and we defined its transcription start site. Following krs transcription at the population and single-cell levels in multiple culture conditions, we depicted a condition-dependent transcription pattern, indicating that production of kurstakin is subject to environmental regulation. Consistent with this idea, we found krs transcription to be regulated by another master regulator, Spo0A, suggesting that krs expression is fine-tuned by integrating multiple signals. We also reported an unknown DNA palindrome in the krs promoter region that modulates krs expression. Due to their surfactant properties, lipopeptides could play several physiological roles. We showed that the krs locus was required for proper biofilm structuration

Male Midwives in France : An Example of Masculinizing a "Feminine" Profession?

International audienceOf 19,208 midwives polled in France in 2010, 349 were men. Based on interviews from a selected group of male midwives and midwifery students, as well as data from a recent study of the midwife profession in France, this study shows that the masculinity brought to this profession by male practitioners can be qualified as "respective masculinity." This theoretical perspective permits a broader consideration of the existing models that explain male presence in non-traditional professions. These models describe their presence as either a power struggle, a means by which to be promoted, or even as a possible questioning of male identity. Male midwives assert their masculinity by seeking autonomy in their work. They are able to work around the obstacle of showing empathy to female patients, typically considered a gendered predisposition. The case of male midwives shows the dynamics of masculinization when taking into account socio-professional contexts.Sur les 19208 sages-femmes exerçant en France en 2010, 349 étaient des hommes. Basé sur des entretiens à partir d'une sélection d'hommes et d'étudiants sages-femmes, ainsi que sur des données d'une étude récente portant sur la profession sage-femme en France, cette étude montre que la masculinité portée par ces praticiens masculins peut être qualifiés de " masculinité respectueuse ". Cette perspective théorique permet une réflexion plus large sur les modèles existants pouvant expliquer la présence des hommes dans des professions non traditionnellement masculine. Ces modèles décrivent leur présence soit comme une lutte de pouvoir, soit un moyen de promotion, ou comme une remise en cause possible de l'identité masculine. Ces sages-femmes affirment leur masculinité en cherchant l'autonomie dans leur travail. Ils sont aussi capables de contourner l'obstacle de l'empathie envers les parturientes, généralement considérée comme une prédisposition sexuée. Le cas des hommes sages-femmes montre qu'il indispensable de croiser les dynamiques de masculinisation avec le contexte socio-professionne

Seismic hazard on the French Riviera : new data, interpretation and simulations

International audienceWe present here a detailed analysis of a seismic data set recorded by a dense seismological network installed over 6 months in the southeast of France. This experiment was set-up at the boundary between the Ligurian basin and the southern subalpine thrust belt (the Nice arc), which is a complex tectonic region that undergoes low to moderate seismicity. We recorded more than 500 microearthquakes, among which 348 occurred exactly in the centre of the network during a very active seismic sequence that lasted mainly over 2 months. We performed an absolute location of all of the events and calculated the magnitudes. Then we applied a cross-correlation technique to gather similar events and to relocate relatively few of them. This method revealed a very clear alignment of 19 events in a direction N120° oblique to the N20° general trend of seismicity. Focal mechanisms were determined for the four largest events and composite solutions for 32 smaller ones. Both the alignments of the earthquakes and the focal solutions revealed that two oblique segments of the fault were activated during the crisis. The main segment (8 km long) that was oriented NNE with a left-lateral strike slip movement is called the Blausasc fault. Taking into account the tectonic evolution and the relationships between surface structures and the distribution of earthquakes, and through a paleaoreconstruction of the tectonic evolution, we propose that the Blausasc fault is the hidden root of the Peille-Laghet fault, which has a mapped length of at least 15 km. The smaller segment (0.6 km long) that was activated during the crisis could be interpreted as an antithetic Riedel fracture. The active Blausasc fault is located in a densely populated zone, at only 10 km from the crowded cities of Monaco and Nice. It is thus particularly interesting to analyse it for hazard assessment. In the last section, we present a simulation that is aimed at predicting what the ground motion in the city of Nice would be like if an earthquake of magnitude 5.7 occurs on this fault. For this, we used the recordings of the largest event of the seismic sequence (Ml= 3.2) and an empirical Green's function summation scheme to simulate the ground motion at two stations situated in urban environments. The values obtained show that especially on soft soil sites, the effects of such an earthquake would be considerable in the city of Nice