Volet documentaire de Paris Sciences Lettres : l\u27occasion de l\u27exemplarité (Le)

La mission d\u27expertise et de conseil dont résulte ce rapport a été demandée par la Fondation Paris Sciences Lettres (P.S.L.). P.S.L. est un Pôle de recherche et d\u27enseignement supérieur d\u27un type particulier, puisqu\u27il réunit de nombreux établissements aux statuts divers et dont les seuls véritables points communs sont l\u27excellence et la part que la recherche y occupe. Au-delà du cas particulier de P.S.L., ce rapport, premier exercice de ce type réalisé par l\u27I.G.B., s\u27est attaché à identifier des problématiques et une méthode susceptibles d\u27être utiles, mutatis mutandis, dans des cas comparables

Syn-tectonic, meteoric water-derived carbonation of the New Caledonia peridotite nappe

International audienceExceptional outcrops recently exposed in the Koniambo massif allow the study of the serpentine sole of the peridotite nappe of New Caledonia (southwest Pacific Ocean). Many magnesite veins are observed, with characteristics indicating that they were emplaced during pervasive top-to-the-southwest shear deformation. The oxygen isotope composition of magnesite is homogeneous (27.4‰ < δ18O < 29.7‰), while its carbon isotope composition varies widely (−16.7‰ < δ13C < −8.5‰). These new data document an origin of magnesite from meteoric fluids. Laterization on top of the peridotite nappe and carbonation along the sole appear to represent complementary records of meteoric water infiltration. Based on the syn-kinematic character of magnesite veins, we propose that syn-laterization tectonic activity has enhanced water infiltration, favoring the exportation of leached elements like Mg, which has led to widespread carbonation along the serpentine sole. This calls for renewed examination of other magnesite-bearing ophiolites worldwide in order to establish whether active tectonics is commonly a major agent for carbonation

On the complementarity between resistivity measurement and ultrasonic measurement for in-situ characterization of phase transitions in Ti-alloys

We present the results of in-situ characterization of the phase transitions in metastable β-Ti alloy Ti5553 by contactless laser-based resonant ultrasound spectroscopy method and electrical resistance measurement in a four probe configuration. Phase transformations were studied during continuous heating from the room temperature to 700 °C with various heating rates. We showed that both methods provide complementary results and can be successfully used for observation of phase transitions in metastable β-Ti alloys

Fusions d\u27universités et la documentation (Les)

Ce rapport présente de premières conclusions des fusions d\u27universités réalisées à Aix-Marseille, à Bordeaux, en Lorraine et à Strasbourg sous différents aspects : préparation de la fusion, nouvelle organisation documentaire, évolution des services aux publics et de la politique documentaire, unification des systèmes d\u27information, immobilier documentaire. Il présente également l\u27état actuel au plan documentaire des autres fusions d\u27universités en cours

Influence of the ageing conditions and the initial microstructure on the precipitation of α phase in Ti-17 alloy

The precipitation of α phase during ageing was investigated in the near-β titanium alloy Ti-17 considering either a fully βmetastable initial microstructure or a 35% αprimary + 65% βmetastable initial microstructure. In-situ electrical resistivity and high energy X-ray diffraction measurements revealed the influence of the initial microstructure, with different α morphologies (size and distribution of αprimary), as well as the heating rate on the precipitation sequences and kinetics following the decomposition of the β-metastable phase. Various amounts of metastable phases (ωisothermal and α″isothermal) precipitate in temperature ranges that increase with the heating rate. From temperatures about 500 °C, the orthorhombic α″isothermal structure evolved towards the hexagonal close-packed α as temperature increased. SEM microstructure characterisations showed that slow heating rates promoted a fine and dense α precipitate distribution through the formation of ωisothermal and/or α″isothermal, leading to higher hardness values. A higher heating rate restricted the precipitation of α″isothermal and shifted to the one of α at a higher temperature, leading to coarser precipitates. Furthermore, precipitation kinetics of α″isothermal/α were quicker considering an initial intragranular α precipitation as compared to α colonies

Rage Par Morsure de Chien dans le Département du Plateau : Etude Connaissances Aptitudes et Pratiques en Communauté et Chez les Agents de Santé

Introduction : La gestion de l'exposition à la rage suite à une morsure de chien constitue un fardeau financier pour les familles des victimes malgré l'importance de la prophylaxie post-exposition pour prévenir l'infection. L'objectif était d'évaluer les connaissances, les attitudes et les pratiques de la population du département du Plateau dans la prévention de la rage humaine. Méthode : La présente étude était transversale, descriptive et a impliqué 900 répondants âgés d'au moins 18 ans vivant dans le département du Plateau depuis au moins six mois. Résultats : L'âge moyen des sujets de l'étude était de 40,24±14,52 ans avec un ratio hommes/femmes de 1,11. Selon les répondants, la rage humaine est une maladie transmise des chiens aux humains (68,22 %) ou provoquée par la sorcellerie (9,44 %). Parmi les personnes interrogées, 69,67 % reconnaissaient la rage comme étant transmise aux humains par des morsures de chiens, des griffures (14,56 %) et des léchages (8,67 %). De même, les moyens de prévention de la rage humaine mentionnés étaient la vaccination canine (49,89 %), l'abattage des chiens errants (21,89 %) et la vaccination post-exposition des humains (7,33 %). Les voies thérapeutiques mentionnées en cas de morsure de chien étaient : le recours au centre de santé (37 %), au praticien traditionnel (26,11 %), au centre de santé en cas d'échec du praticien traditionnel (23,67 %) et les soins à domicile (13,22 %). Conclusion : Cette étude suggère la nécessité de sensibiliser les populations aux risques des morsures de chiens dans le département du Plateau et de mettre en œuvre des stratégies de surveillance pour le contrôle et l'éradication de la rage grâce à la mise en œuvre de l'approche One Health. &nbsp; Introduction: Managing exposure to rabies via dog bite is a financial burden for victims' families despite the importance of post-exposure prophylaxis to prevent infection. The objective was to evaluate the knowledge, attitudes and practices of the population of the Plateau department in the prevention of human rabies. Method: The present study was cross-sectional, descriptive and involved 900 respondents aged at least 18 years living in the Plateau department for at least six months. Results: The average age of the study subjects was 40.24±14.52 years with a sex ratio (Male/Female) of 1.11. According to the respondents, human rabies is a disease transmitted from dogs to humans (68.22%) or induced by witchcraft (9.44%). Of those surveyed, 69.67% recognized rabies as transmitted to humans via dog bites, scratches (14.56%) and licking (8.67%). Likewise, the means of preventing human rabies mentioned were canine vaccination (49.89%), the culling of stray dogs (21.89%) and post-exposure vaccination of humans (7.33%). The therapeutic routes mentioned in the event of a dog bite were: recourse to the health center (37%), to the traditional practitioner (26.11%), to the health center in the event of failure of the traditional practitioner (23.67%) and home care (13.22%) Conclusion: this study suggests the need to raise awareness among populations about the risks of dog bites in the Plateau department and to implement surveillance strategies for the control and eradication of rabies through the implementation of the One Health approach

Carbon content evolution in austenite during austenitization studied by in situ synchrotron X-ray diffraction of a hypoeutectoid steel

Using in situ high energy X-ray diffraction study of austenite formation in hypoeutectoid steel with three differ- ent initial microstructures (ferrite-pearlite, tempered martensite and bainite), the lattice parameters of ferrite, cementite and austenite are examined on heating at 0.25, 10 and 100 °C/s. The lattice parameters of ferrite, cementite and austenite do not vary linearly with the temperature, especially, in the temperature range where the austenitization takes place. For the austenite, it is suggested that the deviation from the linearity is mainly associated to the carbon content variation. Using Dyson and Holmes equation, the carbon content in austenite is evaluated for any moment of the austenite formation for each initial microstructure and all heating rates. For the ferrite-pearlite microstructure heated at 0.25 °C/s, the carbon content in austenite after complete cementite dissolution corresponds to that of pearlite. Moreover, a rapid decrease in carbon content in the austenite is observed during the first stage of the austenitization (simultaneous dissolution of ferrite and cementite) followed by a slow further decrease during the transformation of the remaining ferrite. The obtained results are discussed using thermodynamic calculations

First Detection of Polarization of the Submillimetre Diffuse Galactic Dust Emission by Archeops

We present the first determination of the Galactic polarized emission at 353 GHz by Archeops. The data were taken during the Arctic night of February 7, 2002 after the balloon--borne instrument was launched by CNES from the Swedish Esrange base near Kiruna. In addition to the 143 GHz and 217 GHz frequency bands dedicated to CMB studies, Archeops had one 545 GHz and six 353 GHz bolometers mounted in three polarization sensitive pairs that were used for Galactic foreground studies. We present maps of the I, Q, U Stokes parameters over 17% of the sky and with a 13 arcmin resolution at 353 GHz (850 microns). They show a significant Galactic large scale polarized emission coherent on the longitude ranges [100, 120] and [180, 200] deg. with a degree of polarization at the level of 4-5%, in agreement with expectations from starlight polarization measurements. Some regions in the Galactic plane (Gem OB1, Cassiopeia) show an even stronger degree of polarization in the range 10-20%. Those findings provide strong evidence for a powerful grain alignment mechanism throughout the interstellar medium and a coherent magnetic field coplanar to the Galactic plane. This magnetic field pervades even some dense clouds. Extrapolated to high Galactic latitude, these results indicate that interstellar dust polarized emission is the major foreground for PLANCK-HFI CMB polarization measurement.Comment: Submitted to Astron. & Astrophys., 14 pages, 12 Fig., 2 Table

Temperature and polarization angular power spectra of Galactic dust radiation at 353 GHz as measured by Archeops

We present the first measurement of temperature and polarization angular power spectra of the diffuse emission of Galactic dust at 353 GHz as seen by Archeops on 20% of the sky. The temperature angular power spectrum is compatible with that provided by the extrapolation to 353 GHz of IRAS and DIRBE maps using \cite{fds} model number 8. For Galactic latitudes $|b| \geq 5$ deg we report a 4 sigma detection of large scale ($3\leq \ell \leq 8$) temperature-polarization cross-correlation $(\ell+1)C_\ell^{TE}/2\pi = 76\pm 21 \mu\rm{K_{RJ}}^2$ and set upper limits to the $E$ and $B$ modes at $11 \mu\rm{K_{RJ}}^2$. For Galactic latitudes $|b| \geq 10$ deg, on the same angular scales, we report a 2 sigma detection of temperature-polarization cross-correlation $(\ell+1)C_\ell^{TE}/2\pi = 24\pm 13 \mu\rm{K_{RJ}}^2$. These results are then extrapolated to 100 GHz to estimate the contamination in CMB measurements by polarized diffuse Galactic dust emission. The $TE$ signal is then $1.7\pm0.5$ and $0.5\pm0.3 \mu\rm{K^2_{CMB}}$ for $|b| \geq 5$ and 10 deg. respectively. The upper limit on $E$ and $B$ becomes $0.2 \mu\rm{K^2_{CMB}} (2\sigma)$. If polarized dust emission at higher Galactic latitude cuts is similar to the one we report here, then dust polarized radiation will be a major foreground for determining the polarization power spectra of the CMB at high frequencies above 100 GHz.Comment: 11 pages, 8 figures, submitted to A