Tree leaves extraction in natural images: Comparative study of pre-processing tools and segmentation methods

International audienceIn this paper, we propose a comparative study of various segmentation methods applied to the extraction of tree leaves from natural images. This study follows the design of a mobile application, developed by Cerutti et al. (published in ReVeS Participation-Tree Species Classification Using Random Forests and Botanical Features. CLEF 2012), to highlight the impact of the choices made for segmentation aspects. All the tests are based on a database of 232 images of tree leaves depicted on natural background from smartphones acquisitions. We also propose to study the improvements, in terms of performance, by using pre-processing tools such as the interaction between the user and the application through an input stroke, as well as the use of color distance maps. The results presented in this paper shows that the method developed by Cerutti et al. (denoted Guided Active Contour), obtains the best score for almost all observation criteria. Finally we detail our online benchmark composed of 14 unsupervised methods and 6 supervised ones

Effect of a short-term HAART on SIV load in macaque tissues is dependent on time of initiation and antiviral diffusion

<p>Abstract</p> <p>Background</p> <p>HIV reservoirs are rapidly established after infection, and the effect of HAART initiated very early during acute infection on HIV reservoirs remains poorly documented, particularly in tissue known to actively replicate the virus. In this context, we used the model of experimental infection of macaques with pathogenic SIV to assess in different tissues: (i) the effect of a short term HAART initiated at different stages during acute infection on viral dissemination and replication, and (ii) the local concentration of antiviral drugs.</p> <p>Results</p> <p>Here, we show that early treatment with AZT/3TC/IDV initiated either within 4 hours after intravenous infection of macaques with SIVmac251 (as a post exposure prophylaxis) or before viremia peak (7 days post-infection [pi]), had a strong impact on SIV production and dissemination in all tissues but did not prevent infection. When treatment was initiated after the viremia peak (14 days pi) or during early chronic infection (150 days pi), significant viral replication persists in the peripheral lymph nodes and the spleen of treated macaques despite a strong effect of treatment on viremia and gut associated lymphoid tissues. In these animals, the level of virus persistence in tissues was inversely correlated with local concentrations of 3TC: high concentrations of 3TC were measured in the gut whereas low concentrations were observed in the secondary lymphoid tissues. IDV, like 3TC, showed much higher concentration in the colon than in the spleen. AZT concentration was below the quantification threshold in all tissues studied.</p> <p>Conclusions</p> <p>Our results suggest that limited antiviral drug diffusion in secondary lymphoid tissues may allow persistent viral replication in these tissues and could represent an obstacle to HIV prevention and eradication.</p

More rapid blood interferon α2 decline in fatal versus surviving COVID-19 patients

BackgroundThe clinical outcome of COVID-19 pneumonia is highly variable. Few biological predictive factors have been identified. Genetic and immunological studies suggest that type 1 interferons (IFN) are essential to control SARS-CoV-2 infection.ObjectiveTo study the link between change in blood IFN-α2 level and plasma SARS-Cov2 viral load over time and subsequent death in patients with severe and critical COVID-19.MethodsOne hundred and forty patients from the CORIMUNO-19 cohort hospitalized with severe or critical COVID-19 pneumonia, all requiring oxygen or ventilation, were prospectively studied. Blood IFN-α2 was evaluated using the Single Molecule Array technology. Anti-IFN-α2 auto-Abs were determined with a reporter luciferase activity. Plasma SARS-Cov2 viral load was measured using droplet digital PCR targeting the Nucleocapsid gene of the SARS-CoV-2 positive-strand RNA genome.ResultsAlthough the percentage of plasmacytoid dendritic cells was low, the blood IFN-α2 level was higher in patients than in healthy controls and was correlated to SARS-CoV-2 plasma viral load at entry. Neutralizing anti-IFN-α2 auto-antibodies were detected in 5% of patients, associated with a lower baseline level of blood IFN-α2. A longitudinal analysis found that a more rapid decline of blood IFN-α2 was observed in fatal versus surviving patients: mortality HR=3.15 (95% CI 1.14–8.66) in rapid versus slow decliners. Likewise, a high level of plasma SARS-CoV-2 RNA was associated with death risk in patients with severe COVID-19.ConclusionThese findings could suggest an interest in evaluating type 1 IFN treatment in patients with severe COVID-19 and type 1 IFN decline, eventually combined with anti-inflammatory drugs.Clinical trial registrationhttps://clinicaltrials.gov, identifiers NCT04324073, NCT04331808, NCT04341584

Obama’s Foreign Policy: Is this change we can believe in? ESF Working Paper No. 32, 4 August 2009

President Obama made the strategic choice of distancing himself unequivocally from his predecessor on the international scene. The task ahead is to convince the rest of the world, including the most hostile countries, to share his vision of international affairs and forge ahead with a new foreign policy. This new ESF Working Paper follows the 32nd ESF Forum, chaired by François Heisbourg at CEPS, June 2009, under the title: Obama’s Foreign Policy: Is this change we can believe in? Four experts: David Calleo, of the John Hopkins University, Washington, Camille Grand, Fondation pour la Recherche Stratégique, Paris, Shen Dingli, Fudan University, Shanghai and Ivan Safranchuk, State Institute of International Relations, Moscow, consider President Obama’s chances of foreign policy success

Jacques Sapir. Les bases futures de la puissance militaire russe

Grand. Jacques Sapir. Les bases futures de la puissance militaire russe. In: Politique étrangère, n°3 - 1993 - 58ᵉannée. pp. 779-780

L'ouverture de la procréation médicalement assistée aux couples de femmes et aux femmes célibataires

Ce mémoire traite de la question de l’ouverture de la procréation médicalement assistée (PMA) aux couples de femmes et aux femmes célibataires. L’auteure a choisi de se concentrer uniquement sur l’aspect juridique de la question en étudiant, plus particulièrement, les changements qui devront potentiellement être opérés au sein de notre droit français si jamais une loi ouvrant l’accès à la PMA à toute femme est votée. Suites à ses recherches, elle a pu constater que trois modifications majeures du droit français allaient effectivement devoir être mises en place. Tout d’abord, l’ouverture de la PMA à toutes les femmes va mener à l’abandon du caractère thérapeutique des PMA. En effet, l’élargissement de l’accès aux PMA va faire sortir ces techniques de leur finalité purement thérapeutique et ouvrir la porte aux demandes sociétales visant simplement à utiliser ces procédés pour satisfaire un désir d’enfant. L’assistance médicale à la procréation va ainsi intégrer le domaine largement controversé de la médecine de convenance. De plus, l’ouverture de la PMA à toutes les femmes risque également d’avoir des conséquences sur la question de l’abandon ou non du principe d’anonymat des dons de gamètes. Ce principe, déjà largement controversé au nom du droit à la connaissance de ses origines personnelles, risque d’être remis en cause puisque l’élargissement de la PMA conduira à anéantir la justification principale du maintien de ce principe, à savoir, la doctrine du « ni vu ni connu » qui cherche au maximum à cacher l’origine véritable des enfants nés de PMA et entretient la fiction d’une procréation charnelle. Enfin, une telle réforme devrait également bouleverser le droit français en matière de filiation puisque, si aujourd’hui le droit de la PMA par don de gamètes se base sur le modèle de la procréation charnelle en matière de filiation, l’ouverture de la PMA aux couples de femmes et aux femmes célibataires va mettre en lumière le caractère fictif de ce mode de fonctionnement et la nécessité de créer un troisième mode de filiation, propre aux procréations médicalement assistées et commun à tous les couples recourant aux techniques de PMA nécessitant un don de gamètes

André Collet. Histoire de l'armement depuis 1945

Grand. André Collet. Histoire de l'armement depuis 1945. In: Politique étrangère, n°3 - 1993 - 58ᵉannée. p. 780

André Collet. Histoire de l'armement depuis 1945

Grand. André Collet. Histoire de l'armement depuis 1945. In: Politique étrangère, n°3 - 1993 - 58ᵉannée. p. 780

La défense antimissile : un nouveau paradigme stratégique ?

Missile Defence: The New Stratégie Paradigm? by Camille GRAND Missile defence (MD) is an old strategie debate that has been growing in intensity for some years now, due to the development of ballistic proliferation and a major domestic debate in the US. It is important to understand the evolution of the debate before examining the options available to the Bush administration, whose coming to power marks a turning point favourable to rapid deployment of an antimissile shield to protect American territory. While the September 11 attacks are unlikely to close the debate, there remain a certain number of outstanding questions, which will eventually determine the exact form of the proposed defence and the international reactions to the new American strategic paradigm.La défense antimissile (MD) est un débat stratégique ancien qui connaît depuis quelques années un large renouveau, notamment du fait du développement de la prolifération balistique et d'un important débat intérieur aux Etats-Unis. Il convient donc de comprendre la généalogie de ce débat, avant examiner les options propres à l'Administration Bush, dont l'arrivée marque un nouveau tournant en faveur du déploiement rapide d'un bouclier antimissile protégeant le territoire américain. Alors que les attentats du 11 septembre 2001 sont loin avoir clos ce débat, un certain nombre de questions restent en suspens et devraient in fine déterminer la nature exacte de la MD proposée et des réactions internationales au nouveau paradigme stratégique américain.Grand. La défense antimissile : un nouveau paradigme stratégique ?. In: Politique étrangère, n°4 - 2001 - 66ᵉannée. pp. 811-826