A Robust Logical and Computational Characterisation of Peer-to-Peer Database Systems

In this paper we give a robust logical and computational characterisation of peer-to-peer (p2p) database systems. We first define a precise model-theoretic semantics of a p2p system, which allows for local inconsistency handling. We then characterise the general computational properties for the problem of answering queries to such a p2p system. Finally, we devise tight complexity bounds and distributed procedures for the problem of answering queries in few relevant special cases

Sex and gender analysis in medical and pharmacological research

Gender is an essential determinant of social outcomes, including health. Besides, gender can be separated neither from biology nor from other social identifiers as ethnicity, culture, age or social economic class (United Nations,1995). The concepts of ‘sex’ and ‘gender’ are a face of the nature–culture debate, with the presumption that sex is unchangeable, whereas gender is constructed and can change. Recently, evolutionary psychologists have proposed biological explanations of behaviour by arguing that social constructions may have a biological origin (Taylor et al, 2000). The phenotype is the result of complex interactions between genotype and environment, leading to a lifelong remodelling of our epigenomes, and numerous dimorphic genes expression might be under the control of sex-specific epigenetic marks (Gabory et al, 2009)

Fat quantification with MRI

MR technique offers the opportunity to non-invasively separate fat from water signal. This tutorial will provide an overview of methods to quantify fat with MRI, from T1 based or frequency selective methodologies to chemical shift induced imaging. Underlying principles, advantages and confounding factors will be presented

Chemical shift imaging from simultaneous acquisition of a primary and a stimulated echo

An imaging method is presented for obtaining chemical shift images from only one acquisition. Images are acquired with the same spatial resolution as in regular spin-echo imaging. The sequence is based on the simultaneous acquisition of a spin echo and a stimulated echo in a single pass. The use of 90 degrees radiofrequency pulse flip angles results in the same proton density, T2 and T1 weighting for the two echoes. Application of this sequence to chemical shift imaging is discussed for three fat suppression techniques (chopper, CHESS, and hybrid). Imaging was performed on phatoms and volunteers. The image quality was the same as those obtained by the chopper and the hybrid methods and the acquisition time was reduced by a factor of two

Présentation des plateformes SCIAM et IRM-PRIMEX

Présentation des plateformes SCIAM et IRM-PRIMEX Guillaume Mabilleau et Florence Franconi Université d’Angers, Institut de Biologie en Santé, 49933 Angers, France Le service commun d’imageries et d’analyses microscopiques (SCIAM) et la plateforme d’Imagerie par Résonance Magnétique (IRM) préclinique – PRIMEX sont deux services communs de la SFR ICAT 4208 de l’Université d’Angers. Le SCIAM dispose d’un ensemble dispose d’un microtomographe à rayons X (Bruker microCT 1076) permettant l’acquisition in vivo à des résolutions de 9, 18 et 36 µm et d’un irradiateur à rayons X (Faxitron CP-160). La plateforme PRIMEX dispose d’un imageur Biospec 70/20 Avance III (Bruker Biospin) opérant à un champ magnétique de 7 Tesla. Ces équipements sont particulièrement adaptés pour l’imagerie de la souris ou du rat. Un tour d’horizon du potentiel de ces équipements en préclinique sera présenté. Ces équipements permettent des explorations in vivo chez le petit animal pour des applications telles que la caractérisation anatomique ou fonctionnelle de modèle animaux en oncologie, neurologie, cardiologie… ou l’évaluation de l’efficacité de nouveaux traitements thérapeutiques. Des applications dans d’autres domaines sont aussi possibles (végétal, agroalimentaire, matériaux, ex vivo…). Ces deux plateformes sont ouvertes aux partenaires institutionnels et industriels. Elles proposent un accompagnement scientifique et technique à la conception de projets ainsi que des formations dans le domaine de l’IRM préclinique