Uniqueness of bounded solutions for the homogeneous Landau equation with a Coulomb potential

We prove the uniqueness of bounded solutions for the spatially homogeneous Fokker-Planck-Landau equation with a Coulomb potential. Since the local (in time) existence of such solutions has been proved by Arsen'ev-Peskov (1977), we deduce a local well-posedness result. The stability with respect to the initial condition is also checked

The Vlasov-Poisson-Landau System in Rx3\R^3_x

For the Landau-Poisson system with Coulomb interaction in $\R^3_x$, we prove the global existence, uniqueness, and large time convergence rates to the Maxwellian equilibrium for solutions which start out sufficiently close.Comment: 50 page

Orbital stability of spherical galactic models

International audienceWe consider the three dimensional gravitational Vlasov Poisson system which is a canonical model in astrophysics to describe the dynamics of galactic clusters. A well known conjecture is the stability of spherical models which are nonincreasing radially symmetric steady states solutions. This conjecture was proved at the linear level by several authors in the continuation of the breakthrough work by Antonov in 1961. In a previous work, we derived the stability of anisotropic models under {\it spherically symmetric perturbations} using fundamental monotonicity properties of the Hamiltonian under suitable generalized symmetric rearrangements first observed in the physics litterature. In this work, we show how this approach combined with a {\it new generalized} Antonov type coercivity property implies the orbital stability of spherical models under general perturbations

Association of obesity in shift workers with the minor allele of a single-nucleotide polymorphism (rs4851377) in the largest circadian clock gene (NPAS2)

A growing body of evidence has hinted at the involvement of the largest gene of the circadian clock family, NPAS2, in the regulatory mechanisms underlying the link between metabolic diseases and circadian rhythm disruption. We tested whether one of single-nucleotide polymorphisms in NPAS2 (rs4851377) is associated with obesity and alternations of sleep times in 126 male rotational shift workers (bus drivers). We confirmed positive association of Body Mass Index (BMI) with the difference between free and working days in sleep times, but this difference was smaller in the homozygotes for the minor allele. Moreover, BMI above 30 (obesity) was revealed in the majority of these homozygotes and in the minority of homozygotes for the major allele (11 of 21 or 52.4% and 3 of 40 or 7.5%, respectively). Further studies are required to replicate these results and to elucidate the mechanisms linking NPAS2ʹpolymorphism in with obesity in shift workers. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

Overlap between individual variation in personality traits and sleep-wake behavior

The efforts to link the individual differences in personality to the individual differences in sleep-wake behavior have a long history. One of the topics of such research might be to determine the strength of association between these two domains of individual variation. This requires the implementation of several inventories designed for integrative multidimensional assessments of a set of broad personality traits and a set of sleep-wake behavioral traits. Four independent samples were collected (in total, 759 individuals) for estimating general overlap between the domains of individual variation in personality psychology and chronobiology. Canonical correlation analyses provided the estimates of general overlap of six broad personality traits assessed with the 172-word RCIP (Rugby Cake Inventory of Personality) with six distinct sleep-wake adaptabilities assessed with the 72-item SWPAQ (Sleep-Wake Pattern Assessment Questionnaire) and the SWAT (Sleep-Wake Adaptability Test) in two, the 60- and 168-item, versions. It was demonstrated that general overlap between individual variation in two domains was significant and replicable albeit rather weak (6%–8%). Moreover, regression analyses of specific overlaps of each of six scales for assessing sleep-wake adaptability with a set of six scales for personality assessment suggested that a score on any of adaptability scales seemed to be a significant predictor of, at least, one of six scores on personality trait scales. Studies in other tongues are desired for the replication of the results indicating the statistically significant general and specific overlaps between personality traits and sleep-wake adaptabilities. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature