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The theory of the asymptotic manipulation of pure bipartite quantum systems can be considered completely understood: the rates at which bipartite entangled states can be asymptotically transformed into each other are fully determined by a single number each, the respective entanglement entropy. In the multipartite setting, similar questions of the optimally achievable rates of transforming one pure state into another are notoriously open. This seems particularly unfortunate in the light of the revived interest in such questions due to the perspective of experimentally realizing multipartite quantum networks. In this Letter, we report substantial progress by deriving simple upper and lower bounds on the rates that can be achieved in asymptotic multipartite entanglement transformations. These bounds are based on ideas of entanglement combing and state merging. We identify cases where the bounds coincide and hence provide the exact rates. As an example, we bound rates at which resource states for the cryptographic scheme of quantum secret sharing can be distilled from arbitrary pure tripartite quantum states. This result provides further scope for quantum internet applications, supplying tools to study the implementation of multipartite protocols over quantum networks.

Resume But de l’etude L’etude consiste a evaluer une methode de depistage large par chromatographie liquide couplee a la spectrometrie de masse (ESI-LC/MS) utilisant un logiciel avec bibliotheque de spectres (Chromalynx™, Waters) d’identification automatique des composes detectes, puis de comparer les resultats obtenus avec une methode classique de depistage immunoanalytique (Syva EMIT II/Plus), technique frequemment utilisee en premiere intention pour des analyses toxicologiques. Materiel et methodes Pres de 400 dossiers toxicologiques issus du service d’urgence du centre hospitalier ont ete analyses avec ces deux methodes de depistage. Les resultats rendus positifs par la methode de depistage ESI-LC-MS utilisant le logiciel Chromalynx™ sont systematiquement verifies par chromatographie liquide couple a la spectrometrie de masse en tandem (LC-MS/MS) pour evaluer la fiabilite de la methode. Resultats La methode de depistage ESI-LC-MS avec logiciel de comparaison de spectres a permis de detecter un produit ou plus dans 66 % des dossiers contre 33 % pour la methode immunoanalytique. Les faux positifs (8 % des cas) ainsi que les faux negatifs (2 % des cas) rendus par le logiciel sont facilement interpretables apres analyse des spectres de masse ou si necessaire apres reinjection de l’echantillon avec modification des tensions de cone sauf parfois lors de coelutions avec des composes present en concentration importante qui peuvent masquer un autre compose. Conclusion Cette methode de depistage ESI-LC-MS apparait donc comme etant un moyen efficace de diagnostic face a une intoxication aigue. Elle permet de repondre par molecule contrairement a l’immunoanalyse ou les resultats sont donnes par classe de molecules ce qui est un avantage certain. Le grand nombre de molecules potentiellement detectables en fait une methode de choix, surtout dans les cas d’intoxications non expliquees. C’est une methode qui, comparativement a l’immunoanalyse, beneficie d’une bonne specificite mais qui reste cependant moins sensible, moins rapide et qui necessite plus de connaissances techniques, notamment pour l’interpretation des resultats.

This paper presents power quality study performed on the distribution system of the Universite du Quebec a Trois-Rivieres. The study includes measured waveforms, trends and a statistical analysis of the measurements. The results are analyzed and compared with relevant standards for evaluating the quality of power in the distribution system.

International audience; OBJECTIVES: To study mother to child HIV-1 transmission (MTCT) and infant mortality following benzalkonium chloride (BC) disinfection. METHODS: A randomised, double blind phase II placebo controlled trial. Women testing positive for HIV-1 infection in prenatal care units in Abidjan, Côte d'Ivoire, and Bobo-Dioulasso, Burkina Faso, from November 1996 to April 1997 were eligible, with their informed consent. Women self administered daily a vaginal suppository of 1% BC (53) or matched placebo (54) from 36 weeks of pregnancy, plus a single dose during labour. The neonate was bathed with 1% BC solution or placebo within 30 minutes after birth. MTCT rate was assessed based on repeated polymerase chain reaction (PCR) and serology results. For the present analysis, children were followed up to 15 months. RESULTS: A total of 107 women were enrolled. Of 103 eligible liveborn children, 23 were HIV infected, 75 uninfected, and five of indeterminate status. MTCT transmission rate was 24.2% overall (95% confidence interval (CI): 14.3% to 30.4%). On an intent to treat basis, the transmission rate did not differ between the two groups (23.5%, CI 13.8 to 38.5, in the BC group and 24.8%, CI 15.0 to 39.6, in the placebo group at 15 months). Similarly, there was no difference in mortality at 15 months (22.9%, CI 13.7 to 36.9, in the BC group and 16.5%, CI 9.0 to 29.4, in the placebo group). CONCLUSION: This analysis failed to suggest any benefit of BC disinfection on mother to child HIV transmission or perinatal and infant mortality.