An Exo-Kuiper Belt with an Extended Halo around HD 191089 in Scattered Light

We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ~ 25 au, centered at ~46 au) and a halo extending to ~640 au. We find that the halo is significantly bluer than the ring, consistent with the scenario that the ring serves as the "birth ring" for the smaller dust in the halo. We measure the scattering phase functions in the 30°–150° scattering-angle range and find that the halo dust is more forward- and backward-scattering than the ring dust. We measure a surface density power-law index of −0.68 ± 0.04 for the halo, which indicates the slowdown of the radial outward motion of the dust. Using radiative transfer modeling, we attempt to simultaneously reproduce the (visible) total and (near-infrared) polarized intensity images of the birth ring. Our modeling leads to mutually inconsistent results, indicating that more complex models, such as the inclusion of more realistic aggregate particles, are needed

La pratique outreach auprès des personnes itinérantes souffrant de troubles mentaux graves et persistants : observations, réalités et contraintes

L'équipe itinérance a pour mandat de favoriser l'accessibilité des soins et des services sociaux aux personnes itinérantes de tous âges. Elle a aussi développé des services spécifiques outreach adaptés à la réalité du phénomène de l'itinérance à Montréal. Le principe fondamental qui sous-tend la pratique de l'équipe est l'universalité des soins, tant l'accès que la qualité ; tous les citoyens ont droit à la même attention de la part du réseau de la santé et c'est dans cette optique que les services sont offerts aux personnes itinérantes. Cet article se limite à un seul aspect des activités de l'équipe : la pratique outreach auprès des personnes souffrant de troubles mentaux graves et persistants. Nous décrivons notre environnement outreach, notre clientèle, une trajectoire outreach — illustrée par quelques exemples cliniques — les obstacles rencontrés et, enfin, nous partageons nos observations et suggestions.The outreach practice with homeless people suffering from severe and chronic mental illness: observations, reality and obstacles The team working with homeless people has the mandate to favor access to care and social services for all homeless people regardless of age. It has also developed specific outreach services adapted to the reality of homelessness in Montréal. The fundamental principle underlying our practice is universality, be it access or quality of services; all citizens have the right to the same attention from the health system. It's in this perspective that services are offered to homeless people. This article is limited to one aspect of the team's work : the outreach practice with homeless people suffering from severe and chronic mental illness. The authors describe their outreach environment, their clientele and an example of outreach—llustrated with a few cases—as well as the obstacles met. Finally, the authors share their observations and suggestions.La práctica outreach con las personas itinerantes que sufren de desórdenes mentales graves y persistentes: observaciones, realidades e impedimentos El equipo itinerancia tiene el mandato de favorecer el acceso a los cuidados ofrecidos por los servicios sociales a las personas itinerantes de todas las edades. Igualmente, el equipo ha desarrollado los servicios específicos outreach adaptados a la realidad del fenómeno de la itinerancia en Montreal. El fundamento principal que sostiene la práctica del equipo, es la universalidad de los cuidados, tanto el acceso como la calidad; todos los ciudadanos tienen derecho a la misma atención por parte de la red de salud y es en esta óptica que son ofrecidos los servicios a las personas itinerantes. Este artículo se limita a un solo aspecto de las actividades del equipo: la practica outreach con las personas que sufren de desórdenes mentales graves y persistentes. Describimos nuestro ambiente outreach, nuestra clientela, una trajectoria outreach — ilustrada por algunos ejemplos clínicos — los obstáculos que hemos encontrado y, finalmente, compartimos nuestras observaciones y sugerencias

Associations of social and material deprivation with tobacco, alcohol, and psychotropic drug use, and gender: a population-based study

International audienceBACKGROUND: The aim was to assess the relationships between social and material deprivation and the use of tobacco, excessive alcohol and psychotropic drugs by both sexes and in various age groups. Greater knowledge concerning these issues may help public health policy-makers design more effective means of preventing substance abuse. METHODS: The sample comprised 6,216 people aged > or 15 years randomly selected from the population in north-eastern France. Subjects completed a post-mailed questionnaire covering socio-demographic characteristics, occupation, employment, income, smoking habit, alcohol abuse and "psychotropic" drug intake (for headache, tiredness, nervousness, anxiety, insomnia). A deprivation score (D) was defined by the cumulative number of: low educational level, manual worker, unemployed, living alone, nationality other than western European, low income, and non-home-ownership. Data were analysed using adjusted odds ratios (ORa) computed with logistic models. RESULTS: Deprivation was common: 37.4% of respondents fell into category D = 1, 21.2% into D = 2, and 10.0% into D > or 3a re men than women reported tobacco use (30.2% vs. 21.9%) and alcohol abuse (12.5% vs. 3.3%), whereas psychotropic drug use was more common among women (23.8% vs. 41.0%). Increasing levels of deprivation were associated with a greater likelihood of tobacco use (ORa vs. D = 0: 1.16 in D = 1, 1.49 in D = 2, and 1.93 in D > or = 3), alcohol abuse (1.19 in D = 1, 1.32 in D = 2, and 1.80 in D > or = 3) and frequent psychotropic drug intake (1.26 in D = 1, 1.51 in D = 2, and 1.91 in D > or = 3). These patterns were observed in working/other non-retired men and women (except for alcohol abuse in women). Among retired people, deprivation was associated with tobacco and psychotropic drug use only in men. CONCLUSION: Preventive measures should be designed to improve work conditions, reduce deprivation, and help deprived populations to be more aware of risk and to find remedial measures

An Exo-Kuiper Belt with an Extended Halo around HD 191089 in Scattered Light

We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ~ 25 au, centered at ~46 au) and a halo extending to ~640 au. We find that the halo is significantly bluer than the ring, consistent with the scenario that the ring serves as the "birth ring" for the smaller dust in the halo. We measure the scattering phase functions in the 30°–150° scattering-angle range and find that the halo dust is more forward- and backward-scattering than the ring dust. We measure a surface density power-law index of −0.68 ± 0.04 for the halo, which indicates the slowdown of the radial outward motion of the dust. Using radiative transfer modeling, we attempt to simultaneously reproduce the (visible) total and (near-infrared) polarized intensity images of the birth ring. Our modeling leads to mutually inconsistent results, indicating that more complex models, such as the inclusion of more realistic aggregate particles, are needed

James Webb Space Telescope Optical Simulation Testbed I: Overview and First Results

The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a tabletop workbench to study aspects of wavefront sensing and control for a segmented space telescope, including both commissioning and maintenance activities. JOST is complementary to existing optomechanical testbeds for JWST (e.g. the Ball Aerospace Testbed Telescope, TBT) given its compact scale and flexibility, ease of use, and colocation at the JWST Science & Operations Center. We have developed an optical design that reproduces the physics of JWST's three-mirror anastigmat using three aspheric lenses; it provides similar image quality as JWST (80% Strehl ratio) over a field equivalent to a NIRCam module, but at HeNe wavelength. A segmented deformable mirror stands in for the segmented primary mirror and allows control of the 18 segments in piston, tip, and tilt, while the secondary can be controlled in tip, tilt and x, y, z position. This will be sufficient to model many commissioning activities, to investigate field dependence and multiple field point sensing & control, to evaluate alternate sensing algorithms, and develop contingency plans. Testbed data will also be usable for cross-checking of the WFS&C Software Subsystem, and for staff training and development during JWST's five- to ten-year mission.Comment: Proceedings of the SPIE, 9143-150. 13 pages, 8 figure

CRH – Laboratoire de démographie historique (LDH)

Stéphane Baciocchi, Pascal Cristofoli, ingénieurs d’étudesFlorence Maillochon, chargée de recherche au CNRSZacarias Moutoukias, professeur à l’Université Paris-VII/DiderotChristophe Prieur, maître de conférences à l’Université Paris-VII/DiderotMarie-Carmen Smyrnelis Approches des réseaux sociaux Ce séminaire se propose d’aborder, avec une posture interdisciplinaire, les différentes approches pratiques et théoriques impliquées lors de la mise en oeuvre d’analyses relationnelles. Il s’est organ..

First description of an IgM monoclonal antibody causing αIIb β3 integrin activation and acquired Glanzmann thrombasthenia associated with macrothrombocytopenia

BACKGROUND: Acquired Glanzmann thrombasthenia (GT) is a bleeding disorder generally caused by anti-αIIb β3 autoantibodies. OBJECTIVES: We aimed to characterize the molecular mechanism leading to a progressive GT-like phenotype in a patient with chronic immune thrombocytopenia. PATIENT, METHODS AND RESULTS: The patient suffered from repeated episodes of gastrointestinal bleedings and further studies indicated a moderate platelet aggregation defect. Few months later, platelet function showed abolished aggregation using all agonists, but normal agglutination with ristocetin. No platelet-bound antibodies were detected, but the presence of large amounts of an IgM type antibody detected together with αIIb β3 in the patient's permeabilized platelets suggested that this IgM was an autoantibody causing the internalization of the complex. This was confirmed by the fact that the patient's IgM bound to normal platelets but not to platelets from GT type I patients. Moreover, patient's plasma activated αIIb β3 on controls' platelets as evidenced by increased PAC-1 binding. We also demonstrated that the patient's plasma triggered αIIb β3 outside-in signaling, as β3 Tyr773 and FAK were phosphorylated, and increased the rate of actin polymerization in resting platelets reflecting an impairment of cytoskeletal reorganization. As different signs of dysmegakariopoiesis were also observed in our patient, we evaluated the ability of its serum to impair proplatelets formation and showed that it significantly decreased the number of proplatelet-bearing megakaryocytes in controls' bone marrow stem cells culture as compared to normal serum. CONCLUSIONS: We present the case of a patient with a progressive and severely perturbed platelet function associated with the presence of an IgM activating autoantibody directed against αIIb β3 . This article is protected by copyright. All rights reserved

Characterization of HD 206893 B from Near- to Thermal-infrared

HD 206893 B is a brown-dwarf companion orbiting inside the debris disk of its host star. We detect the brown dwarf in the Ms band using the Keck/NIRC2 instrument and vortex coronagraph. We measure its magnitude to be ${Ms}={12.97}_{-0.11}^{0.10}$ . It is at an angular separation of 0"22 ± 0"03, and a position angle of 39.6° ± 5.4° east of north. Using this Ms-band measurement and the system age, we use three evolutionary models to estimate the mass to be 12-78 M[SUB]Jup[/SUB]. We analyze the atmospheric properties from 1-5 μm using a grid of simulated atmospheric models. We find that a sedimentation flux f[SUB]sed[/SUB] value ~0.2 provides the best fit to the data, suggesting high vertically extended clouds. This may be indicative of high-altitude grains or a circumplanetary disk. Our model radii and luminosities for the companion find the best fits are ages of <100 Myr and masses <20 M[SUB]Jup[/SUB], consistent with our mass estimate from the evolutionary models using the Ms-band data alone. We detect orbital motion of the brown dwarf around the host star in comparison to the discovery image and derive orbital parameters. Finally we analyze how the companion brown dwarf interacts with the debris disk by estimating the location of the chaotic zone around the brown dwarf using values derived from this study's estimated mass and orbital constraints. We find that the collisions within the debris belt are likely driven by secular perturbations from the brown dwarf, rather than self-stirring.EPI

Statistical ecology comes of age

The desire to predict the consequences of global environmental change has been the driver towards more realistic models embracing the variability and uncertainties inherent in ecology. Statistical ecology has gelled over the past decade as a discipline that moves away from describing patterns towards modelling the ecological processes that generate these patterns. Following the fourth International Statistical Ecology Conference (1-4 July 2014) in Montpellier, France, we analyse current trends in statistical ecology. Important advances in the analysis of individual movement, and in the modelling of population dynamics and species distributions, are made possible by the increasing use of hierarchical and hidden process models. Exciting research perspectives include the development of methods to interpret citizen science data and of efficient, flexible computational algorithms for model fitting. Statistical ecology has come of age: it now provides a general and mathematically rigorous framework linking ecological theory and empirical data.Peer reviewe

Ankyrin G restricts ion channel diffusion at the axonal initial segment before the establishment of the diffusion barrier

Ion channel immobilization by ankyrin G is regulated by casein kinase 2 in immature hippocampal neurons