165 research outputs found

    Experimental particle astrophysics

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    CD1 Gene Polymorphisms and Phenotypic Variability in X-Linked Adrenoleukodystrophy

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    X-linked adrenoleukodystrophy (X-ALD) is characterized by marked phenotypic variation ranging from adrenomyeloneuropathy (AMN) to childhood cerebral ALD (CCALD). X-ALD is caused by mutations in the ABCD1 gene, but no genotype-phenotype correlation has been established so far and modifier gene variants are suspected to modulate phenotypes. Specific classes of lipids, enriched in very long-chain fatty acids that accumulate in plasma and tissues from X-ALD patients are suspected to be involved in the neuroinflammatory process of CCALD. CD1 proteins are lipid- antigen presenting molecules encoded by five CD1 genes in human (CD1A-E). Association studies with 23 tag SNPs covering the CD1 locus was performed in 52 patients with AMN and 87 patients with CCALD. The minor allele of rs973742 located 4-kb downstream from CD1D was significantly more frequent in AMN patients (χ2 = 7.6; P = 0.006). However, this association was no longer significant after Bonferroni correction for multiple testing. The other polymorphisms of the CD1 locus did not reveal significant association. Further analysis of other CD1D polymorphisms did not detect stronger association with X-ALD phenotypes. Although the association with rs973742 warrants further investigations, these results indicate that the genetic variants of CD1 genes do not contribute markedly to the phenotypic variance of X-ALD

    GeneFarm, structural and functional annotation of Arabidopsis gene and protein families by a network of experts

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    Genomic projects heavily depend on genome annotations and are limited by the current deficiencies in the published predictions of gene structure and function. It follows that, improved annotation will allow better data mining of genomes, and more secure planning and design of experiments. The purpose of the GeneFarm project is to obtain homogeneous, reliable, documented and traceable annotations for Arabidopsis nuclear genes and gene products, and to enter them into an added-value database. This re-annotation project is being performed exhaustively on every member of each gene family. Performing a family-wide annotation makes the task easier and more efficient than a gene-by-gene approach since many features obtained for one gene can be extrapolated to some or all the other genes of a family. A complete annotation procedure based on the most efficient prediction tools available is being used by 16 partner laboratories, each contributing annotated families from its field of expertise. A database, named GeneFarm, and an associated user-friendly interface to query the annotations have been developed. More than 3000 genes distributed over 300 families have been annotated and are available at http://genoplante-info.infobiogen.fr/Genefarm/. Furthermore, collaboration with the Swiss Institute of Bioinformatics is underway to integrate the GeneFarm data into the protein knowledgebase Swiss-Prot

    GeneFarm, structural and functional annotation of Arabidopsis gene and protein families by a network of experts

    Get PDF
    Genomic projects heavily depend on genome annotations and are limited by the current deficiencies in the published predictions of gene structure and function. It follows that, improved annotation will allow better data mining of genomes, and more secure planning and design of experiments. The purpose of the GeneFarm project is to obtain homogeneous, reliable, documented and traceable annotations for Arabidopsis nuclear genes and gene products, and to enter them into an added-value database. This re-annotation project is being performed exhaustively on every member of each gene family. Performing a family-wide annotation makes the task easier and more efficient than a gene-by-gene approach since many features obtained for one gene can be extrapolated to some or all the other genes of a family. A complete annotation procedure based on the most efficient prediction tools available is being used by 16 partner laboratories, each contributing annotated families from its field of expertise. A database, named GeneFarm, and an associated user-friendly interface to query the annotations have been developed. More than 3000 genes distributed over 300 families have been annotated and are available at http://genoplante-info.infobiogen.fr/Genefarm/. Furthermore, collaboration with the Swiss Institute of Bioinformatics is underway to integrate the GeneFarm data into the protein knowledgebase Swiss-Pro

    Observation of Microlensing towards the Galactic Spiral Arms: EROS II 3 year survey

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    We present an analysis of the light curves of 9.1 million stars observed during three seasons by EROS (Experience de Recherche d'Objets Sombres), in the Galactic plane away from the bulge. Seven stars exhibit luminosity variations compatible with gravitational microlensing effects due to unseen objects. The corresponding optical depth, averaged over four directions, is tau = 0.45 +0.24 -0.11 x 10^-6. While this value is compatible with expectations from simple galactic models under reasonable assumptions on the target distances, we find an excess of events with short timescale towards the direction closest to the Galactic Centre

    Méthode des éléments finis et décomposition de domaines (Application à l'étude de l'interaction électromagnétique onde-composant)

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    L'implantation quasi systématique de systÚmes électroniques au sein de la majorité des dispositifs qui nous entourent rend de plus en plus indispensable la prise en compte des effets parasites créés par des interactions électromagnétiques. C'est dans ce contexte que ces travaux ont été mis en place afin de confirmer quantitativement et qualitativement les effets d'une onde plane électromagnétique de forte puissance sur un dispositif actif, représenté ici par un transistor à effet de champ HP07 de la société UMS. La démarche est basée sur une méthode hybride fusionnant la méthode des éléments finis dans le domaine fréquentiel pour toute l'analyse électromagnétique, et un logiciel de type circuit pour la partie active hyperfréquence. Le couplage électromagnétique entre le transistor et l'onde plane étant de type "back door", ce dernier est englobé dans une structure métallique partiellement ouverte : le cylindre OTAN. L'hétérogénéité des dimensions de ce cylindre avec celles de TEC, ainsi que la complexité de ses ouvertures ont été les principales motivations de l'implémentation d'une excitation électromagnétique supplémentaire au sein du logiciel développé à l'IRCOM afin d'optimiser la méthode de décomposition de domaines.LIMOGES-BU Sciences (870852109) / SudocSudocFranceF

    A Mixed Finite Element Formulation for Microwave Devives Problems. Application to MIS Structure

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    International audienceA mixed finite element formulation for analysing the propagation characteristics of lossy dissipative waveguides is presented. Maxwell's equations are expressed in terms of the transverse electric and magnetic field components. This formulation is discretized using the mixed finite element and the classical Lagrange's one. A comparison of these discretizations shows that the use of this mixed finite element eliminates the spurious modes. This method is applied to computing the propagation characteristics of a MIS microstrip line
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