Imaging EEG synchronization in schizophrenia patients with S-estimator

Recently a new measure of the cooperative behavior of simultaneous time series was introduced (Carmeli et al. NeuroImage 2005). This measure called S-estimator is defined from the embedding dimension in a state space. S-estimator quantifies the amount of synchronization within a data set by comparing the actual dimensionality of the set with the expected full dimensionality of the asynchronous set. It has the advantage of being a multivariate measure over traditionally used in systems neuroscience bivariate measures of synchronization. Multivariate measures of synchronization are of particular interest for applications in the field of modern multichannel EEG research, since they easily allow mapping of local and/or regional synchronization and are compatible with other imaging techniques. We applied Sestimator to the analysis of EEG synchronization in schizophrenia patients vs. matched controls. The whole-head mapping with S-estimator revealed a specific pattern of local synchronization in schizophrenia patients. The differences in the landscape of synchronization included decreased local synchronization in the territories over occipital and midline areas and increased synchronization over temporal areas. In frontal areas, the S-estimator revealed a tendency for an asymmetry: decreased S-values over the left hemisphere were adjacent to increased values over the right hemisphere. Separate calculations showed reproducibility of this pattern across the main EEG frequency bands. The maintenance of the same synchronization landscape across EEG frequencies probably implies the structural changes in the cortical circuitry of schizophrenia patients. These changes are regionally specific and suggest that schizophrenia is a misconnectivity rather than hypo- or hyper-connectivity disorder.

Defining the role of common variation in the genomic and biological architecture of adult human height.

Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ∼2,000, ∼3,700 and ∼9,500 SNPs explained ∼21%, ∼24% and ∼29% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/β-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants.

Recherches nouvelles sur les "Evangiles latins de l'enfance" de M. R. James et sur un récit apocryphe mal connu de la naissance de Jésus

Les Evangiles latins de l'enfance ont été peu étudiés depuis l'édition de M. R. James en 1927. La prochaine publication dans la Series apocryphorum des Évangiles irlandais de l'enfance jette un éclairage nouveau sur cette compilation latine qui combine le Protévangile de Jacques, l'Évangile du Pseudo-Matthieu et une 3e Source non identifiée racontant la naissance de Jésus. Les récits irlandais du Leabar Breac et du Liber Flavus Fergusiorum permettent de remonter à un état antérieur à la compilation, pas encore influencé par le Pseudo-Matthieu. Ils conservent parfois des éléments du texte de la Source qui ont disparu dans le latin. Le récit original de cette source inconnue est indépendant du Protévangile de Jacques et pourrait être aussi ancien que lui. C'est ce qui ressort de l'étude par l'A. de quelques motifs caractéristiques : l'impôt lié au recensement, la pauvreté de Joseph, le rôle des fils de Joseph, le lieu de la nativité, l'épisode de la sage-femme.

The effects of dominance, regular inbreeding and sampling design on Q(ST), an estimator of population differentiation for quantitative traits.

To test whether quantitative traits are under directional or homogenizing selection, it is common practice to compare population differentiation estimates at molecular markers (F(ST)) and quantitative traits (Q(ST)). If the trait is neutral and its determinism is additive, then theory predicts that Q(ST) = F(ST), while Q(ST) > F(ST) is predicted under directional selection for different local optima, and Q(ST) < F(ST) is predicted under homogenizing selection. However, nonadditive effects can alter these predictions. Here, we investigate the influence of dominance on the relation between Q(ST) and F(ST) for neutral traits. Using analytical results and computer simulations, we show that dominance generally deflates Q(ST) relative to F(ST). Under inbreeding, the effect of dominance vanishes, and we show that for selfing species, a better estimate of Q(ST) is obtained from selfed families than from half-sib families. We also compare several sampling designs and find that it is always best to sample many populations (>20) with few families (five) rather than few populations with many families. Provided that estimates of Q(ST) are derived from individuals originating from many populations, we conclude that the pattern Q(ST) > F(ST), and hence the inference of directional selection for different local optima, is robust to the effect of nonadditive gene actions.

Fonctions psychologiques du religieux: Cent ans après "Varieties" de William James

La première traduction en français de « The Varieties of Religious Experience » fut publiée en 1906 et elle connut aussitôt un très grand retentissement. Dans cet ouvrage, William James affirme: « D'un point de vue tout psychologique, la religion est une fonction éternelle de l'esprit humain ». Toutefois, caractériser la religion par une fonction si fondamentale, sous-jacente à tous les systèmes de croyances, ne conduit pas James à porter un regard dévalorisant sur la multiplicité des formes religieuses. Au contraire, il y voit l'expression de la variété des combinaisons possibles du religieux avec la vie psychique sous ses différents aspects. Ce livre a pour but non seulement de relire William James un siècle après la publication de Varieties, mais aussi de préciser, sur la base des connaissances actuelles, quelles sont les fonctions psychologiques du religieux.