Virtualisation de serveurs à l'aide d'un logiciel de cloud

Depuis le début 2011, le LAL (Laboratoire de l'Accélérateur Linéaire) expérimente une gestion de type " cloud " (privé) de ses ressources, pour permettre la mise en œuvre de serveurs plus personnalisés tant pour les besoins des utilisateurs que pour les services centraux du laboratoire, avec une allocation dynamique des ressources physiques disponibles. Entre autres, nous avons utilisé la virtualisation de notre infrastructure web, actuellement 100 sites web sur quelques machines physiques, comme projet de validation des potentialités de l'approche " cloud privé ". De plus, cette gestion dynamique fournira la haute disponibilité, sans utiliser de technologie de clustering complexe, aux services virtualisés qui le nécessitent. La mise en place de ce " cloud privé " au LAL s'appuie sur le projet européen FP7 StratusLab, qui sera décrit dans la présentation. Ce projet développe une plateforme opensource permettant la mise en œuvre de " cloud " de type IaaS ("Infrastructure as a Service"). La plateforme StratusLab fournit des services innovants comme la certification d'image virtuelle de référence (marketplace), une interface utilisateur simple pour l'utilisation du cloud et une API implémentant les principaux standards d'accès aux ressources d'un cloud (OCCI, CDMI...). Elle fournit aussi l'intégration avec des outils de gestion de configuration, tels Quattor ou à l'avenir Puppet. Afin de garantir un développement qui suive au plus près les besoins des utilisateurs et des administrateurs de site, le projet StratusLab utilise une méthodologie agile de développement logiciel, celle-ci, entre autres, permet une réponse rapide aux différents besoins à travers des releases fréquentes

The Green Computing Observatory: a data curation approach for green IT

International audienceThe Green Computing Observatory (GCO) is a collaborative effort to provide the scientific community with a comprehensive set of traces of energy consumption of a production cluster. These traces include the detailed monitoring of the hardware and software, as well as global site information such as the overall consumption and overall cooling. The acquired data is transformed into an XML format built from a specifically designed ontology and published through the Grid Observatory website

Enhancing e-Infrastructures with Advanced Technical Computing: Parallel MATLAB® on the Grid

MATLAB® is widely used within the engineering and scientific fields as the language and environment for technical computing, while collaborative Grid computing on e-Infrastructures is used by scientific communities to deliver a faster time to solution. MATLAB allows users to express parallelism in their applications, and then execute code on multiprocessor environments such as large-scale e-Infrastructures. This paper demonstrates the integration of MATLAB and Grid technology with a representative implementation that uses gLite middleware to run parallel programs. Experimental results highlight the increases in productivity and performance that users obtain with MATLAB parallel computing on Grids

Un cas de brucellose canine à Brucella abortus

Une chienne, Berger des Pyrénées, vivant dans un élevage bovin, est trouvée porteuse de B. abortus, biotype I, sept mois après avoir avorté. L’infection de cette chienne et celle d’un taureau sont concomitantes. Cette observation permet de rappeler et résumer les principales publications qui montrent la grande importance des chiens comme vecteurs de la brucellose.A Berger des Pyrenees bitch, living in a farm, was found harboring B. abortus , biotype I, in a lymph node, seven months after abortion. The canine Brucella infection was coincidental to a bull brucellosis. This observation together with a summary of the available littérature help to recall the great importance of dogs as vectors of brucella infection

Usefulness and limitation of dobutamine stress echocardiography to predict acute response to cardiac resynchronization therapy.

peer reviewedBackground: It has been hypothesized that a long-term response to cardiac resynchronization therapy (CRT) could correlate with myocardial viability in patients with left ventricular (LV) dysfunction. Contractile reserve and viability in the region of the pacing lead have not been investigated in regard to acute response after CRT. Methods: Fifty-one consecutive patients with advanced heart failure, LV ejection fraction ≤ 35%, QRS duration > 120 ms, and intraventricular asynchronism ≥ 50 ms were prospectively included. The week before CRT implantation, the presence of viability was evaluated using dobutamine stress echocardiography. Acute responders were defined as a ≥15% increase in LV stroke volume. Results: The average of viable segments was 5.8 ± 1.9 in responders and 3.9 ± 3 in nonresponders (P = 0.03). Viability in the region of the pacing lead had an excellent sensitivity (96%), but a low specificity (56%) to predict acute response to CRT. Mitral regurgitation (MR) was reduced in 21 patients (84%) with acute response. The presence of MR was a poor predictor of response (sensibility 93% and specificity 17%). However, combining the presence of MR and viability in the region of the pacing lead yields a sensibility (89%) and a specificity (70%) to predict acute response to CRT. Conclusion: Myocardial viability is an important factor influencing acute hemodynamic response to CRT. In acute responders, significant MR reduction is frequent. The combined presence of MR and viability in the region of the pacing lead predicts acute response to CRT with the best accuracy

Transmission congénitale de la brucellose bovine d’une génération à l’autre

Plommet M., Renoux G., Philippon Alain, Gestin J., Fenster-Bank R. Transmission congénitale de la brucellose bovine d’une génération à l’autre. In: Bulletin de l'Académie Vétérinaire de France tome 124 n°1, 1971. pp. 53-59

Zero Order Estimates for Analytic Functions

The primary goal of this paper is to provide a general multiplicity estimate. Our main theorem allows to reduce a proof of multiplicity lemma to the study of ideals stable under some appropriate transformation of a polynomial ring. In particular, this result leads to a new link between the theory of polarized algebraic dynamical systems and transcendental number theory. On the other hand, it allows to establish an improvement of Nesterenko's conditional result on solutions of systems of differential equations. We also deduce, under some condition on stable varieties, the optimal multiplicity estimate in the case of generalized Mahler's functional equations, previously studied by Mahler, Nishioka, Topfer and others. Further, analyzing stable ideals we prove the unconditional optimal result in the case of linear functional systems of generalized Mahler's type. The latter result generalizes a famous theorem of Nishioka (1986) previously conjectured by Mahler (1969), and simultaneously it gives a counterpart in the case of functional systems for an important unconditional result of Nesterenko (1977) concerning linear differential systems. In summary, we provide a new universal tool for transcendental number theory, applicable with fields of any characteristic. It opens the way to new results on algebraic independence, as shown in Zorin (2010).Comment: 42 page

Elliptic logarithms, diophantine approximation and the Birch and Swinnerton-Dyer conjecture

Most, if not all, unconditional results towards the abc-conjecture rely ultimately on classical Baker's method. In this article, we turn our attention to its elliptic analogue. Using the elliptic Baker's method, we have recently obtained a new upper bound for the height of the S-integral points on an elliptic curve. This bound depends on some parameters related to the Mordell-Weil group of the curve. We deduce here a bound relying on the conjecture of Birch and Swinnerton-Dyer, involving classical, more manageable quantities. We then study which abc-type inequality over number fields could be derived from this elliptic approach.Comment: 20 pages. Some changes, the most important being on Conjecture 3.2, three references added ([Mas75], [MB90] and [Yu94]) and one reference updated [BS12]. Accepted in Bull. Brazil. Mat. So

Infectious consequences of hematoma from cardiac implantable electronic device procedures and the role of the antibiotic envelope: A WRAP-IT trial analysis.

Hematoma is a complication of cardiac implantable electronic device (CIED) procedures and may lead to device infection. The TYRX antibacterial envelope reduced major CIED infection by 40% in the randomized WRAP-IT (World-wide Randomized Antibiotic Envelope Infection Prevention Trial) study, but its effectiveness in the presence of hematoma is not well understood.The purpose of this study was to evaluate the incidence and infectious consequences of hematoma and the association between envelope use, hematomas, and major CIED infection among WRAP-IT patients.All 6800 study patients were included in this analysis (control 3429; envelope 3371). Hematomas occurring within 30 days postprocedure (acute) were characterized and grouped by study treatment and evaluated for subsequent infection risk. Data were analyzed using Cox proportional hazard regression modeling.Acute hematoma incidence was 2.2% at 30 days, with no significant difference between treatment groups (envelope vs control hazard ratio [HR] 1.15; 95% confidence interval [CI] 0.84-1.58; P = .39). Through all follow-up, the risk of major infection was significantly higher among control patients with hematoma vs those without (13.1% vs 1.6%; HR 11.3; 95% CI 5.5-23.2; P.001). The risk of major infection was significantly lower in the envelope vs control patients with hematoma (2.5% vs 13.1%; HR 0.18; 95% CI 0.04-0.85; P = .03).The risk of hematoma was 2.2% among WRAP-IT patients. Among control patients, hematoma carried a11-fold risk of developing a major CIED infection. This risk was significantly mitigated with antibacterial envelope use, with an 82% reduction in major CIED infection among envelope patients who developed hematoma compared to control