Stellar Kinematics of the Double Nucleus of M31

We report observations of the double nucleus of M31 with the f/48 long-slit spectrograph of the HST Faint Object Camera. We obtain a total exposure of 19,000 sec. over 7 orbits, with the 0.063-arcsec-wide slit along the line between the two brightness peaks (PA 42). A spectrum of Jupiter is used as a spectral template. The rotation curve is resolved, and reaches a maximum amplitude of ~250 km/s roughly 0.3 arcsec either side of a rotation center lying between P1 and P2, 0.16 +/- 0.05 arcsec from the optically fainter P2. We find the velocity dispersion to be < 250 km/s everywhere except for a narrow ``dispersion spike'', centered 0.06 +/- 0.03 arcsec on the anti-P1 side of P2, in which sigma peaks at 440 +/- 70 km/s. At much lower confidence, we see local disturbances to the rotation curve at P1 and P2, and an elevation in sigma at P1. At very low significance we detect a weak asymmetry in the line-of-sight velocity distribution opposite to the sense usually encountered. Convolving our V and sigma profiles to CFHT resolution, we find good agreement with the results of Kormendy & Bender (1998, preprint), though there is a 20% discrepancy in the dispersion that cannot be attributed to the dispersion spike. Our results are not consistent with the location of the maximum dispersion as found by Bacon et al. We find that the sinking star cluster model of Emsellem & Combes (1997) does not reproduce either the rotation curve or the dispersion profile. The eccentric disk model of Tremaine (1995) fares better, and can be improved somewhat by adjusting the original parameters. However, detailed modeling will require dynamical models of significantly greater realism.Comment: 29 pages, Latex, AASTeX v4.0, with 7 eps figures. To appear in The Astronomical Journal, February 199

Analyse de la non-linéarité acoustique de contact pour l' évaluation et le contrôle non destructif

Les effets non-linéaires produits par l'interaction entre une onde et une fissure fermée peuvent être un moyen potentiel pour la détection de ces fissures. Ce travail porte sur l'étude et l'analyse de la non-linéarité de contact générée par la propagation d'une onde à travers une fissure fermée. Notre approche repose sur la modélisation numérique par Eléments finis (EF) dont la résolution est effectuée dans le domaine temporel. La fissure est modélisée par une loi de contact unilatéral avec frottement de Coulomb. L'outil numérique mis en place est utilisé pour l'analyse de la méthode de génération d'harmoniques et sa relation avec la dynamique de contact. Le cas d'une interface de contact entre deux solides a permis d'estimer l'influence de l'état de contrainte sur le comportement non-linéaire, et a fait l'objet d'une validation expérimentale. La diffusion non-linéaire d'une fissure fermée orientée est ensuite obtenue en couplant la solution numérique à une méthode semi-analytique afin d'obtenir les diagrammes de directivité. Les mécanismes impliqués dans l'interaction onde - fissure sont mis en évidence. Ces résultats nous permettent ensuite d'appliquer la méthode du mixage d'ondes non-colinéaire, d'abord sur une interface de contact puis sur une fissure fermée. L'étude numérique et les premiers résultats expérimentaux démontrent le potentiel de la méthode en terme de détection, de caractérisation et d'imagerie.The nonlinear effects produced by the interaction between a closed crack and an ultrasonic wave can be a good mean for the detection or thecharacterization of such cracks. This work is dedicated to the study and the analysis of the contact acoustic nonlinearity involved during the interaction of acoustic waves and closed cracks. Our approach is based on Finite Element (FE) modeling. The crack is modeled by unilateral contact with Coulomb's friction law, and numerical solutions are computed in the time domain. The numerical tool is used to analyze the method of higher harmonic generation and its relation with contact dynamics. First, the case of an interface between two solids in contact is considered, both numerically and experimentally, and it was shown that the nonlinear behavior depend on the state of stress. Then, nonlinear elastic scattering by a closed crack of various orientations was calculated. A hybrid model coupling FE and semi-analytical solutions was set up to compute the scattered field and to plot directivity diagrams. The nonlinear mechanisms involved in the interaction between a wave and a closed crack are highlighted. Using those results, the non-collinear mixing technique was applied for measuring the nonlinear response of a contact interface and a closed crack. The numerical results, as well as the first experimental results, are very promising for detecting, locating and imaging closed cracks.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Mapping the Migratory Movements

Based on several conventional geography works and/or artistic works – some of them made by the authors of this paper –, this article focuses on how the mapping of international migrations has evolved since the beginning of the 1990s. The representation of migratory movements, which oscillates between arrows, measurements of stocks and different forms of design, implies both scientific and political stakes for the cartography and geography of migrations. After making a brief recalling of the changes that the mapping of migratory flows has experienced from its origins in the 19th century until today, the authors refer to the main technical and epistemological challenges that cartography of migratory movements and the presentations of itineraries raise nowadays. Finally the article analyses the new cartographic forms that have emerged since the beginning of the 2000s within the interconnected domains of sciences, arts, and militancy.À partir de diverses réalisations conventionnelles en géographie et/ou artistiques, parmi lesquels des travaux réalisés par les auteurs, cet article s’intéresse à la manière dont la cartographie des migrations internationales a évolué depuis le début des années 1990. La représentation des mouvements migratoires, qui oscille entre des flèches, des mesures de stocks et diverses formes de dessin, soulève autant d’enjeux scientifiques et politiques posés à la cartographie et géographie des migrations. Après un bref rappel des changements qu’a connus la cartographie des flux migratoires, depuis ses origines, au XIXe siècle, jusqu’à aujourd’hui, les auteurs évoquent les principaux défis techniques et épistémologiques que les cartes de flux ou représentant des itinéraires ne cessent de poser. Puis pour terminer, sont présentées de nouvelles formes cartographiques, ayant émergé depuis le début des années 2000, dans les domaines croisés de la science, de l’art et du militantisme.Partiendo de diversos trabajos convencionales de geografía y/o artísticos – algunos de ellos realizados por los propios autores –, este artículo pretende mostrar cómo la cartografía de las migraciones internacionales ha ido evolucionando desde principios de los años 1990. La representación de los movimientos migratorios, que abarca desde flechas, hasta medidas de reserva y diferentes formas de diseño, supone para la cartografía y la geografía de las migraciones toda una serie de retos, tanto científicos como políticos. Tras hacer un repaso de los cambios que ha ido experimentando la cartografía de los flujos migratorios desde sus orígenes en el siglo XIX hasta la actualidad, los autores presentan los principales retos técnicos y epistemológicos que los mapas de flujos y las representaciones de itinerarios continúan planteando en el momento actual. Por último, se presentan nuevas formas cartográficas surgidas a partir del 2000 que se inscriben en ámbitos interconectados como la ciencia, el arte y el activismo

Lensing at cosmological scales: a test of higher dimensional gravity

Recent developments in gravitational lensing astronomy have paved the way to genuine mappings of the gravitational potential at cosmological scales. We stress that comparing these data with traditional large scale structure surveys will provide us with a test of gravity at such scales. These constraints could be of great importance in the framework of higher dimensional cosmological models.Comment: 4 pages, latex, 3 figure

Positive and negative affect is related to experiencing chest pain during exercise-induced myocardial ischemia

© 2017 by the American Psychosomatic Society. Objective: Silent myocardial ischemia is thought to be associated with worse cardiovascular outcomes due to a lack of perception of pain cues that initiate treatment seeking. Negative affect (NA) has been associated with increased pain reporting and positive affect (PA) with decreased pain reporting, but these psychological factors have not been examined within the context of myocardial ischemia. This study evaluated the associations between PA, NA, and chest pain reporting in patients with and without ischemia during exercise testing. Methods: A total of 246 patients referred for myocardial perfusion single-photon emission computed tomography exercise stress testing completed the positive and negative affect schedule-expanded version, a measure of PA and NA. Presence of chest pain and myocardial ischemia were evaluated using standardized protocols. Results: Logistic regression analyses revealed that for every 1-point increase in NA, there was a 13% higher chance for ischemic patients (odds ratio [OR] = 1.13; 95 % confidence interval [CI] = 1.02 to 1.26) and an 11% higher chance in nonischemic patients (OR = 1.11; 95% CI = 1.03 to 1.19) to report chest pain. A significant interaction of PA and NA on chest pain reporting (ß = 0.02; 95% CI = 0.002 to 0.031) was also observed; nonischemic patients with high NA and PA reported more chest pain (57%) versus patients with low NA and low PA (13%), with high NA and low PA (17%), and with high PA and low NA (7%). Conclusions: Patients who experience higher NA are more likely to report experiencing chest pain. In patients without ischemia, high NA and PA was also associated with a higher likelihood of reporting chest pain. Results suggest that high levels of PA as well as NA may increase the experience and/or reporting of chest pain

Symposium on Obesity and Asthma-November 2006

L’asthme et l’obésité sont fréquemment associés et l’obésité est considérée comme un facteur impliqué tant dans l’augmentation de la sévérité que dans le développement de l’asthme. Ce document est un compte-rendu des présentations effectuées dans le cadre d’un symposium du Réseau en santé respiratoire du Fonds de la recherche en santé du Québec qui a eu lieu à Montréal le 2 novembre 2006, en collaboration avec le McGill University – Strauss Severe Asthma Program, l’Université Laval (Québec) et l’Université de Montréal. Au cours de cette rencontre, divers aspects de la relation entre obésité et asthme ont été abordés, en regard des modèles animaux, des influences génétiques, hormonales et physiologiques, de l’influence des comorbidités (ex : syndrome d’apnée du sommeil), de l’épidémiologie, des aspects cliniques et psychologiques et, enfin, du traitement de l’asthme chez la personne obèse.Asthma and obesity are frequently associated, and obesity has been considered a factor contributing to both an increase in severity of asthma and to its development. The present document summarizes the proceedings of a symposium held in Montreal, Quebec, on November 2, 2006, under the auspices of the Réseau en santé respiratoire du Fonds de la recherche en santé du Québec in collaboration with the McGill University - Strauss Severe Asthma Program, Université Laval (Quebec City) and Université de Montréal. It includes an overview of the various aspects of the relationships between asthma and obesity with regard to animal models; genetic, hormonal and physiological determinants; influence of comorbidities (eg, sleep apnea syndrome); epidemiology; clinical and psychological features; and management of asthma in the obese population

MARTX Toxin in the Zoonotic Serovar of Vibrio vulnificus Triggers an Early Cytokine Storm in Mice

Vibrio vulnificus biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTXVv (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA13), which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing in vitro, ex vivo, and in vivo assays. First, we demonstrated that the ACD domain, present exclusively in this toxin variant, effectively has an actin-cross-linking activity. Second, we determined that the whole toxin caused death of human endotheliocytes and monocytes by lysis and apoptosis, respectively. Finally, we tested the hypothesis that RtxA13 contributes to human death caused by this zoonotic serovar by triggering an early cytokine storm in blood. To this end, we used a Bt2-SerE strain (R99) together with its rtxA13 deficient mutant, and a Bt1 strain (YJ016) producing RtxA11 (the most studied MARTXVv) together with its rtxA11 deficient mutant, as controls. Our results showed that RtxA13 was essential for virulence, as R99ΔΔrtxA13 was completely avirulent in our murine model of infection, and that R99, but not strain YJ016, induced an early, strong and dysregulated immune response involving the up-regulation of a high number of genes. This dysregulated immune response was directly linked to RtxA13. Based on these results and those obtained ex vivo (human blood), we propose a model of infection for the zoonotic serovar of V. vulnificus, in which RtxA13 would act as a sepsis-inducing toxin

Nanoscale Stiffness Distribution in Bone Metastasis

Nanomechanical heterogeneity is expected to have an effect on elasticity, injury and bone remodelling. In normal bone, we have two types of cells (osteoclasts and osteoblasts) working together to maintain existing bone. Bone cancers can produce factors that make the osteoclasts work harder. This means that more bone is destroyed than rebuilt, and leads to weakening of the affected bone. We report here the first demonstration of the nanoscale stiffness distribution in bone metastases before and after treatment of animals with the bisphosphonate Risedronate, a drug which is currently used for the treatment of bone metastases in patients with advanced cancers. The strategy used here is applicable to a wide class of biological tissues and may serve as a new reflection for biologically inspired scaffolds technologies

Late Pleistocene mammalian assemblages of Southeast Asia: New dating, mortality profiles and evolution of the predator-prey relationships in an environmental context

Karstic sites have great potential for yielding data regarding changes in faunal communities in the Pleistocene of Southeast Asia. In this region, the majority of fossil-bearing deposits are karstic breccias, which generally demonstrate a complicated sedimentary history. While most of the mammalian assemblages recovered in these deposits are only composed of isolated teeth, their study remains essential for reconstructing paleoecology and paleoclimatology of the region. We analyzed the assemblages recovered in three mainland and two insular karstic sites: Tam Hang South and Nam Lot in northern Laos, Duoi U'Oi in northern Vietnam, Punung in central Java and Sibrambang in western Sumatra and obtained new chronologies for three of these sites so that their significance could be discussed within their correct chronological context. The resulting age ranges place the sites in MIS5 and M1S4. The comparative analysis of the faunas, in terms of taphonomy, taxonomic diversity and abundance, and mortality profiles (Cervus unicolor, Sus scrofa, Sus vittatus, rhinocerotids and Tapirus indicus), reveals marked differences in prey-predators (carnivores and/or humans) relationships in relation to habitat. The study of homininesbearing sites (Punung, Nam Lot, Duoi U'Oi) allows us to emphasize different interactions with large carnivores (felids, hyaenids, canids). (C) 2015 Elsevier B.V. All rights reserved