Improved global sea surface height and current maps from remote sensing and in situ observations

We present a new gridded sea surface height and current dataset produced by combining observations from nadir altimeters and drifting buoys. This product is based on a multiscale and multivariate mapping approach that offers the possibility to improve the physical content of gridded products by combining the data from various platforms and resolving a broader spectrum of ocean surface dynamic than in the current operational mapping system. The dataset covers the entire global ocean and spans from 1 July 2016 to 30 June 2020. The multiscale approach decomposes the observed signal into different physical contributions. In the present study, we simultaneously estimate the mesoscale ocean circulations as well as part of the equatorial wave dynamics (e.g. tropical instability and Poincaré waves). The multivariate approach is able to exploit the geostrophic signature resulting from the synergy of altimetry and drifter observations. Sea-level observations in Arctic leads are also used in the merging to improve the surface circulation in this poorly mapped region. A quality assessment of this new product is proposed with regard to an operational product distributed in the Copernicus Marine Service. We show that the multiscale and multivariate mapping approach offers promising perspectives for reconstructing the ocean surface circulation: observations of leads contribute to improvement of the coverage in delivering gap-free maps in the Arctic and observations of drifters help to refine the mapping in regions of intense dynamics where the temporal sampling must be accurate enough to properly map the rapid mesoscale dynamics. Overall, the geostrophic circulation is better mapped in the new product, with mapping errors significantly reduced in regions of high variability and in the equatorial band. The resolved scales of this new product are therefore between 5 % and 10 % finer than the Copernicus product (https://doi.org/10.48670/moi-00148, Pujol et al., 2022b).</p

Restitution d’élévations architecturales à partir de blocs fragmentaires : l’exemple de la Vigna Barberini

Les fouilles de la Vigna Barberini ont mis au jour les fondations de trois grands ensembles édilitaires successifs, auxquels devraient appartenir les très nombreux fragments de décor d’architecture recueillis durant les mêmes recherches. L’article reprend les différentes étapes de l’analyse et du classement de ce mobilier, en exposant les procédures et la méthode adoptées pour le traiter. Observations directes, relevés et photographies sont associés dans ce travail à l’utilisation des ressources informatiques. L’ensemble converge au sein d’une base de données conçue en tenant compte tant des caractères spécifiques de la documentation que des questionnements qu’elle suscite. Des liens peuvent ainsi être rétablis entre des objets apparemment isolés et ce sont des ensembles de blocs que l’on peut maintenant confronter avec les structures dégagées pour contribuer à en restituer les élévations.Ubelmann Yves. Restitution d’élévations architecturales à partir de blocs fragmentaires : l’exemple de la Vigna Barberini. In: Mélanges de l'École française de Rome. Antiquité, tome 118, n°2. 2006. Antiquité. pp. 653-670

Pompéi. : Villa de Diomède

Mis en ligne le 02 février 2015, consulté le 19 janvier 2017. URL : http://cefr.revues.org/1293International audienc

Computer Aided facial reconstruction of Mary-Magdalene relics following hair and skull analyses

International audienceThe supposed relics of "Mary-Magdalene" are preserved in Provence (France) in an ancient tradition. They consist of a dry skull and a lock of hair. For the first time, they were officially subjected to an extensive medico-surgical examination by photogrammetry, high-magnification binocular lenses, scanning electron microscope, and energy-dispersive X-ray elemental analysis, to propose a full computer-aided facial reconstruction. The preliminary results are presented here

Amyloid-β-independent regulators of tau pathology in Alzheimer disease

The global epidemic of Alzheimer disease (AD) is worsening, and no approved treatment can revert or arrest progression of this disease. AD pathology is characterized by the accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles in the brain. Genetic data, as well as autopsy and neuroimaging studies in patients with AD, indicate that Aβ plaque deposition precedes cortical tau pathology. Because Aβ accumulation has been considered the initial insult that drives both the accumulation of tau pathology and tau-mediated neurodegeneration in AD, the development of AD therapeutics has focused mostly on removing Aβ from the brain. However, striking preclinical evidence from AD mouse models and patient-derived human induced pluripotent stem cell models indicates that tau pathology can progress independently of Aβ accumulation and arises downstream of genetic risk factors for AD and aberrant metabolic pathways. This Review outlines novel insights from preclinical research that implicate apolipoprotein E, the endocytic system, cholesterol metabolism and microglial activation as Aβ-independent regulators of tau pathology. These factors are discussed in the context of emerging findings from clinical pathology, functional neuroimaging and other approaches in humans. Finally, we discuss the implications of these new insights for current Aβ-targeted strategies and highlight the emergence of novel therapeutic strategies that target processes upstream of both Aβ and tau