Kick synchronization versus diffusive synchronization

The paper provides an introductory discussion about two fundamental models of oscillator synchronization: the (continuous-time) diffusive model, that dominates the mathematical literature on synchronization, and the (hybrid) kick model, that accounts for most popular examples of synchronization, but for which only few theoretical results exist. The paper stresses fundamental differences between the two models, such as the different contraction measures underlying the analysis, as well as important analogies that can be drawn in the limit of weak coupling.Peer reviewe

Shape Self-Regulation in Early Lung Morphogenesis

The arborescent architecture of mammalian conductive airways results from the repeated branching of lung endoderm into surrounding mesoderm. Subsequent lung’s striking geometrical features have long raised the question of developmental mechanisms involved in morphogenesis. Many molecular actors have been identified, and several studies demonstrated the central role of Fgf10 and Shh in growth and branching. However, the actual branching mechanism and the way branching events are organized at the organ scale to achieve a self-avoiding tree remain to be understood through a model compatible with evidenced signaling. In this paper we show that the mere diffusion of FGF10 from distal mesenchyme involves differential epithelial proliferation that spontaneously leads to branching. Modeling FGF10 diffusion from sub-mesothelial mesenchyme where Fgf10 is known to be expressed and computing epithelial and mesenchymal growth in a coupled manner, we found that the resulting laplacian dynamics precisely accounts for the patterning of FGF10-induced genes, and that it spontaneously involves differential proliferation leading to a self-avoiding and space-filling tree, through mechanisms that we detail. The tree’s fine morphological features depend on the epithelial growth response to FGF10, underlain by the lung’s complex regulatory network. Notably, our results suggest that no branching information has to be encoded and that no master routine is required to organize branching events at the organ scale. Despite its simplicity, this model identifies key mechanisms of lung development, from branching to organ-scale organization, and could prove relevant to the development of other branched organs relying on similar pathways

Activation of mutated TRPA1 ion channel by resveratrol in human prostate cancer associated fibroblasts (CAF)

Previous studies showed the effects of resveratrol (RES) on several cancer cells, including prostate cancer (PCa) cell apoptosis without taking into consideration the impact of the tumor microenvironment (TME). The TME is composed of cancer cells, endothelial cells, blood cells and cancer-associated fibroblasts (CAF), the main source of growth factors. The latter cells might modify in the TME the impact of RES on tumor cells via secreted factors. Recent data clearly show the impact of CAF on cancer cells apoptosis resistance via secreted factors. However, the effects of RES on PCa CAF have not been studied so far. We have investigated here for the first time the effects of RES on the physiology of PCa CAF in the context of TME. Using a prostate cancer CAF cell line and primary cultures of CAF from prostate cancers, we show that RES activates the N-terminal mutated Transient Receptor Potential Ankyrin 1 (TRPA1) channel leading to an increase in intracellular calcium concentration and the expression and secretion of growth factors (HGF and VEGF) without inducing apoptosis in these cells. Interestingly, in the present work, we also show that when the prostate cancer cells were co-cultured with CAF, the RES-induced cancer cell apoptosis was reduced by 40%, an apoptosis reduction canceled in the presence of the TRPA1 channel inhibitors. The present work highlights CAF TRPA1 ion channels as a target for RES and the importance of the channel in the epithelial-stromal crosstalk in the TME leading to resistance to the RES-induced apoptosis

Governance traditions and narratives of public sector reform in contemporary France.

This article explores the basic traditions of governance in contemporary France and the narratives of public sector reform associated with them. It should be stressed right from the outset that this article does not aim to describe the set of public sector reforms that have been implemented in France in the last ten years or so. Instead, the aim is to demonstrate the similarities and differences between the narratives of the left and the right with regard to these reforms and to show how these narratives help to explain the types of reform that have been enacted. The basic argument is that there is a certain commonality to both the left and the right with regard to their narratives of public sector reform. At the same time, though, there are differences of emphasis both within each tradition and between the two main traditions themselves. Except where indicated, all translations are the author's own

Tunnel sous la Manche, TGV Nord-Européen : une opportunité pour le développement d'une métropole régionale à l'échelle européenne

The tunnel and the High Speed Train are trump cards for Lille and the Nord Region, and the opportunity to reinforce existing advantages and to prepare for the new development with an ambitious programme of development. However it is necessary to enhance the effect of the High Speed Train by a junction in lille and by improving rail and road links, while making an effort to turn Lille into an international business centre.Le Tunnel et le TGV sont des atouts pour Lille et la Région du Nord, une opportunité pour renforcer les avantages existants et préparer le nouveau développement par un plan de développement ambitieux. Mais il faut valoriser l'effet du TGV par le croisement dans Lille et par l'amélioration des relations ferroviaires et routières, en essayant de développer à Lille un centre international d'affaires.Mauroy Pierre. Tunnel sous la Manche, TGV Nord-Européen : une opportunité pour le développement d'une métropole régionale à l'échelle européenne. In: Hommes et Terres du Nord, 1988/1-2. Tunnel sous la manche et développement régional en Europe du Nord-Ouest. pp. 30-31

N° 44 — Pierre MAUROY

Mauroy Pierre, Frank Marie-Thérèse, Mignaval Pierre. N° 44 — Pierre MAUROY. In: Témoins et acteurs des politiques de l'éducation depuis la Libération. Tome 2 - Inventaire de soixante-six entretiens. Paris : Institut national de recherche pédagogique, 2000. pp. 128-129. (Témoins et acteurs des politiques de l'éducation, 1