Zoomer n’est pas explorer:Spatialiser les graphes, catégoriser et (dé)construire les réseaux

A partir du cas du web du livre en France, cet article interroge la notion de zoom dans l’exploration visuelle de réseaux. En soumettant un graphe à des questionnements et traitements successifs, il devient possible de comprendre ce qui apparaît comme une anomalie pour le chercheur, un entrelacement sur le plan visuel de deux communautés pourtant distinctes du point de vue des catégories et de l’algorithme de modularité. En appliquant ces différentes épreuves au graphe apparaît la variété des algorithmes de spatialisation et de clusterisation, les limites des notions de zoom, de découpage et d’exploration des réseaux, toutes métaphores spatiales peu pertinentes. Cette démarche plaide pour des conventions d’exploration qui assurent la robustesse de l’exploitation de ce type de données.Zooming is not exploring. Spatializing graphs, categorizing and (de)constructing networks. Based on the case of the web of books in France, this article discusses the notion of zooming in the visual exploration of networks. By subjecting a graph to a series of questions and successive processes, it becomes possible to understand what seems to be an anomaly for the researcher : a visual entanglement of two otherwise distinct communities from the point of view of the categories and algorithm of modularity. By applying these different tests to the graph, the variety of the algorithms of spatialization and clustering emerge, along with the limits of the notions of zooming, partitioning and exploration of networks, all of which are largely irrelevant spatial metaphors. This approach argues for exploratory conventions that guarantee robust exploitation of this type of data

[Mechanisms of structural plasticity associated with photic synchronization of the circadian clock within the suprachiasmatic nucleus]

International audienceThe mammalian circadian clock, whose central component is located in the suprachiasmatic nucleus of the hypothalamus (SCN), orchestrates rhythmic events in metabolism, physiology and behavior. Adaptation of the organism to its environment requires precise adjustment of the clock to the 24 h astronomical time, primarily by the light/dark cycle. Photic synchronization acts on both the molecular loops which trigger circadian oscillations and the phasing of the multiple SCN cellular oscillators whose coordination permits elaboration of the rhythmic message that will be distributed throughout the organism. It is concomitant with structural plastic events characterized by day/night rearrangements of the SCN neuronal-glial network. The two main sources of SCN efferents, namely the VIP (vasoactive intestinal peptide)-synthesizing neurons which are major integrators of photic signals and the AVP (arginine-vasopressin)-synthesizing neurons which are known to importantly contribute to conveying rhythmic messages to brain targets, are involved in these mechanisms. Over the light/dark cycle, they indeed undergo ultrastructural changes in the extent of their membrane coverage by glial, axon terminal and/or somato-dendritic elements. These structural rearrangements appear to be dependent on light entrainment, as the rhythmic expression in SCN of glial fibrillary acidic protein (GFAP), a marker for brain astrocytes whose changing expression has proved to be a reliable index of neuronal-glial plasticity, is disrupted under constant darkness. Glucocorticoid hormones, which are known as important endocrine outputs of the clock, are required to maintain amplitude of the SCN GFAP rhythm to normal values, indicating that they modulate astrocytic plasticity within the SCN and, therefore, nycthemeral changes of the configuration of its neuronal-glial network. The view that such plastic events may subserve synchronization of the clock to the light-dark cycle is reinforced by other data showing that the daily fluctuations of circulating glucocorticoids actually are involved in modulation of light effects, contributing to the resistance of the circadian timing system to variations of the photoperiod. It is thus proposed that the capacity of the clock to integrate cyclic variations of the environment rely on the inherent capacity of the SCN to undergo neuronal-glial plasticity

Syndrome myéloprolifératif avec polyglobulie et translocation t(6;8)(q27;p11) : cas clinique et revue de la littérature

International audienc

Techniques, stratégies et alimentation pour temps de guerre

Lors des conflits contemporains, voient le jour des initiatives techniques novatrices ou de nature à s’inspirer de pratiques anciennes afin d’augmenter les volumes de productions agricoles ou d’adapter des recettes face à la pénurie et aux restrictions, de veiller à un conditionnement plus particulièrement adapté à la conservation des produits et des mets, et enfin de mettre en place les transports les plus adéquats destinés à nourrir au mieux le plus grand nombre de personnes tout en cherchant à garantir la sécurité de la chaîne alimentaire. Dans quelle mesure l’État parvient-il, ou non, à organiser un nouveau système de répartition des vivres ? Comment les entreprises se transforment-elles et participent-elles aux modifications qui marquent la société ? Quels problèmes techniques et sanitaires doivent être résolus afin de répartir les denrées ? L’impact des nouveautés techniques demeure-t-il effectif lors du retour à la paix ? Les textes de ce dossier apportent des éclairages pour répondre à ces questions

Prognostic value of high-sensitivity measurable residual disease assessment after front-line chemoimmunotherapy in chronic lymphocytic leukemia

International audienceMeasurable residual disease (MRD) status is widely adopted in clinical trials in patients with chronic lymphocytic leukemia (CLL). Findings from FILO group trials (CLL2007FMP, CLL2007SA, CLL2010FMP) enabled investigation of the prognostic value of high-sensitivity (0.7 × 10-5) MRD assessment using flow cytometry, in blood (N = 401) and bone marrow (N = 339), after fludarabine, cyclophosphamide, and rituximab (FCR)-based chemoimmunotherapy in a homogeneous population with long follow-up (median 49.5 months). Addition of low-level positive MRD < 0.01% to MRD ≥ 0.01% increased the proportion of cases with positive MRD in blood by 39% and in bone marrow by 27%. Compared to low-level positive MRD < 0.01%, undetectable MRD was associated with significantly longer progression-free survival (PFS) when using blood (72.2 versus 42.7 months; hazard ratio 0.40, p = 0.0003), but not when using bone marrow. Upon further stratification, positive blood MRD at any level, compared to undetectable blood MRD, was associated with shorter PFS irrespective of clinical complete or partial remission, and a lower 5-year PFS rate irrespective of IGHV-mutated or -unmutated status (all p < 0.05). In conclusion, high-sensitivity (0.0007%) MRD assessment in blood yielded additional prognostic information beyond the current standard sensitivity (0.01%). Our approach provides a model for future determination of the optimal MRD investigative strategy for any regimen