1,786 research outputs found

    BeppoSAX observations of the quasar Markarian 205

    Full text link
    We present the first BeppoSAX observation (0.1 to 220 keV) of the quasar Mrk 205. We have searched for the unusual Fe line profile claimed in the XMM-Newton spectrum which has been widely discussed in recent literature. We find no evidence for a broad, ionized Fe line component in our data. We detect for the first time a Compton hump in this object. Besides, when this component is included in the fit, the line strength diminishes, in agreement with a recent re-analysis of the XMM-Newton data, but with better constraints on the reflection component thanks to the PDS instrument (15-220 keV). We interpret this fact as another indication for illumination of a distant and cold material rather than reprocessing in the highly ionized inner parts of an accretion disk. We cannot constrain the presence of a high energy cutoff but we confirm the existence of a variable soft excess (one year timescale).Comment: 13 pages, 12 figures, accepted for publication in A&

    Le tabagisme chez les écoliers en Valais: 2002-2010

    Get PDF
    Introduction: Le tabagisme est une cause majeure de maladies et de décès dans la population en Valais. Près d'un valaisan sur trois et une valaisanne sur quatre sont fumeurs. L'initiation au tabagisme a lieu le plus souvent à l'adolescence. Il est dès lors important de connaître les habitudes tabagiques des écoliers valaisans. Méthodes: Tous les quatre ans, le Valais et les autres cantons suisses participent à l'enquête Health Behaviour in School aged Chidren (HBSC), qui est réalisée dans plus de 40 pays sous l'égide de l'Organisation mondiale de la santé. L'objectif est de récolter et d'analyser des données pertinentes sur les comportements de santé des écoliers de 11 à 15 ans, et notamment sur le tabagisme. L'enquête HBSC 2010 a été menée dans 71 classes auprès de 1'198 écoliers en Valais. Les données ont été récoltées par questionnaire. Résultats: De nombreux écoliers valaisans de 11-15 ans ont déjà fumé au moins une fois dans leur vie. Alors que très peu d'écoliers sont des fumeurs quotidiens avant l'âge de 14 ans, près d'un écolier sur six (17% des garçons et des filles) affirme fumer quotidiennement à 15 ans. Entre 2002 et 2010, les proportions d'écoliers ayant fumé au moins une fois ou fumant quotidiennement ont diminué. Les écoliers de 14-15 ans fumant régulièrement (au moins une fois par semaine) rapportent avoir acheté le plus souvent eux mêmes leurs cigarettes ou se les êtres procurées auprès de connaissances. 42% des écoliers et 44% des écolières ont au moins leur mère, leur père ou un de leurs frères et soeurs qui fument. Conclusions et perspectives : Le tabagisme est fréquent dans la population valaisanne, et ce dès l'adolescence. La prévalence du tabagisme a légèrement diminué chez les écoliers entre 2002 et 2010. Toutefois, l'augmentation marquée de l'initiation tabagique entre 11 et 15 ans et la prévalence importante des fumeurs quotidiens parmi les écoliers de 15 ans confirment que la prévention du tabagisme est nécessaire dès le plus jeune âge. L'accessibilité des écoliers au tabac devrait être évaluée et des mesures devraient être renforcées pour la diminuer

    A birational mapping with a strange attractor: Post critical set and covariant curves

    Full text link
    We consider some two-dimensional birational transformations. One of them is a birational deformation of the H\'enon map. For some of these birational mappings, the post critical set (i.e. the iterates of the critical set) is infinite and we show that this gives straightforwardly the algebraic covariant curves of the transformation when they exist. These covariant curves are used to build the preserved meromorphic two-form. One may have also an infinite post critical set yielding a covariant curve which is not algebraic (transcendent). For two of the birational mappings considered, the post critical set is not infinite and we claim that there is no algebraic covariant curve and no preserved meromorphic two-form. For these two mappings with non infinite post critical sets, attracting sets occur and we show that they pass the usual tests (Lyapunov exponents and the fractal dimension) for being strange attractors. The strange attractor of one of these two mappings is unbounded.Comment: 26 pages, 11 figure

    Strain and correlation of self-organized Ge_(1-x)Mn_x nanocolumns embedded in Ge (001)

    Full text link
    We report on the structural properties of Ge_(1-x)Mn_x layers grown by molecular beam epitaxy. In these layers, nanocolumns with a high Mn content are embedded in an almost-pure Ge matrix. We have used grazing-incidence X-ray scattering, atomic force and transmission electron microscopy to study the structural properties of the columns. We demonstrate how the elastic deformation of the matrix (as calculated using atomistic simulations) around the columns, as well as the average inter-column distance can account for the shape of the diffusion around Bragg peaks.Comment: 9 pages, 7 figure

    Green Currents for Meromorphic Maps of Compact K\"ahler Manifolds

    Full text link
    We consider the dynamics of meromorphic maps of compact K\"ahler manifolds. In this work, our goal is to locate the non-nef locus of invariant classes and provide necessary and sufficient conditions for existence of Green currents in codimension one.Comment: Statement of Theorem 1.5 is slightly improved. Proposition 5.2 and Theorem 5.3 are adde

    Sentinel Lymph-Node Biopsy in Early-Stage Cervical Cancer: The 4-Year Follow-Up Results of the Senticol 2 Trial.

    Get PDF
    Senticol 2 is a randomized multicenter trial in the treatment of early-stage cervical cancer patients. The aim of the Senticol 2 study was to compare the effect of sentinel-lymph-node biopsy (SLNB) to that of SLNB + pelvic lymphadenectomy (PLND), and to determine the postoperative lymphatic morbidity in the two groups. Here, we report a secondary objective of this study: the follow up. In the Senticol 2 trial, patients underwent a laparoscopy with a sentinel-node-detection procedure and were randomized into two groups, namely: Group A, in which participants received SLNB, and Group B, in which participants received SLNB + PLND. Patients with an intra-operative macroscopically suspicious lymph node, were given a frozen-section evaluation and were randomized only if the results were negative. All of the patients received follow up with a clinical examination at 1, 3, and 6 months after surgery, and then every 3-4 months after that. The median follow up was 51 months (4 years and 3 months). Disease-free survival after 4 years for the SLNB group and the SLNB + PLND group were 89.51% and 93.1% (p = 0.53), respectively. The only statistical factor associated with recurrence in the univariate analysis was the adjuvant radiotherapy. No other factors, including the age of the patients, histological type, tumor size, lymph vascular space invasion (LVSI), and positive nodal status, were significant in the univariate or multivariate analyses. The overall survival rates after 4 years in the SLNB and SLNB + PLND groups were 95.2% and 96% (p = 0.97), with five and four deaths, respectively. The univariate and multivariate analyses did not find any prognostic factors. This randomized study confirmed the results of the Senticol 1 study and supports the sentinel lymph node (SLN) technique as a safe technique for use in patients with early-stage cervical cancer treated with SLNB only. Disease-free survival after 4 years was similar in patients treated with SLN biopsy and patients who underwent a lymphadenectomy
    corecore