Synchronization of Spatiotemporal Chaos: The regime of coupled Spatiotemporal Intermittency

Synchronization of spatiotemporally chaotic extended systems is considered in the context of coupled one-dimensional Complex Ginzburg-Landau equations (CGLE). A regime of coupled spatiotemporal intermittency (STI) is identified and described in terms of the space-time synchronized chaotic motion of localized structures. A quantitative measure of synchronization as a function of coupling parameter is given through distribution functions and information measures. The coupled STI regime is shown to dissapear into regular dynamics for situations of strong coupling, hence a description in terms of a single CGLE is not appropiate.Comment: 4 pages, LaTeX 2e. Includes 3 figures made up of 8, 4 (LARGE),and 2 postscript files. Includes balanced.st

ALIX binds a YPX(3)L motif of the GPCR PAR1 and mediates ubiquitin-independent ESCRT-III/MVB sorting.

The sorting of signaling receptors to lysosomes is an essential regulatory process in mammalian cells. During degradation, receptors are modified with ubiquitin and sorted by endosomal sorting complex required for transport (ESCRT)-0, -I, -II, and -III complexes into intraluminal vesicles (ILVs) of multivesicular bodies (MVBs). However, it remains unclear whether a single universal mechanism mediates MVB sorting of all receptors. We previously showed that protease-activated receptor 1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, is internalized after activation and sorted to lysosomes independent of ubiquitination and the ubiquitin-binding ESCRT components hepatocyte growth factor-regulated tyrosine kinase substrate and Tsg101. In this paper, we report that PAR1 sorted to ILVs of MVBs through an ESCRT-III-dependent pathway independent of ubiquitination. We further demonstrate that ALIX, a charged MVB protein 4-ESCRT-III interacting protein, bound to a YPX(3)L motif of PAR1 via its central V domain to mediate lysosomal degradation. This study reveals a novel MVB/lysosomal sorting pathway for signaling receptors that bypasses the requirement for ubiquitination and ubiquitin-binding ESCRTs and may be applicable to a subset of GPCRs containing YPX(n)L motifs

Forecasting the SST space-time variability of the Alboran Sea with genetic algorithms

We propose a nonlinear ocean forecasting technique based on a combination of genetic algorithms and empirical orthogonal function (EOF) analysis. The method is used to forecast the space-time variability of the sea surface temperature (SST) in the Alboran Sea. The genetic algorithm finds the equations that best describe the behaviour of the different temporal amplitude functions in the EOF decomposition and, therefore, enables global forecasting of the future time-variability.Comment: 15 pages, 3 figures; latex compiled with agums.st

Seismic entangled patterns analyzed via multiresolution decomposition

This article explores a method for distinguishing entangled coherent structures embedded in geophysical images. The original image is decomposed in a series of j-scale-images using multiresolution decomposition. To improve the image processing analysis each j-image is divided in l-spacial regions generating set of (j, l)-regions. At each (j, l)-region we apply a continuous wavelet transform to evaluate <i>E</i><sub>ν</sub>, the spectrum of energy. <i>E</i><sub>ν</sub> has two maxima in the original data. Otherwise, at each scale <i>E</i><sub>ν</sub> hast typically one peak. The localization of the peaks changes according to the (j, l)-region. The intensity of the peaks is linked with the presence of coherent structures, or patterns, at the respective (j, l)-region. The method is successfully applied to distinguish, in scale and region, the ground roll noise from the relevant geologic information in the signal

Madagascar, politique forestière : Bilan 1990 – 2013 et propositions

Les auteurs dressent une rétrospective de la mise en oeuvre de la politique environnementale et forestière 1990-2013 qui repose sur quatre lois, à savoir la Charte de l’environnement (loi 90-033 du 21 décembre 1990), la GELOSE (loi 96-025 du 30 septembre 1996), la loi forestière (loi 97-017 du 8 août 1997) et le Code des Aires protégées (loi 2001-005 du 11 février 2003). Vingt ans après l’adoption de la Nouvelle Politique Forestière, un bilan est possible. Ces textes ont connu un début d’application avec un bilan décevant dans un contexte surtout marqué par une extension de la superficie des aires protégées. Dans le même temps, des évolutions importantes et positives sont apparues. Avec la  décentralisation, l’.é.tat de droit s’est construit quotidiennement au niveau des communes à travers les guichets fonciers, les contrats de transferts de gestion et les expériences positives de contrôle forestier décentralisé. Ont également été réalisées des expériences concluantes de valorisation économique des ressources forestières exploitées dans le cadre des transferts de gestion : bois d’oeuvre, bois énergie, raphia, huiles essentielles. Il est donc possible, en novembre 2013, d’envisager de façon réaliste une relance vigoureuse de la politique forestière en tenant compte des invariants comme les faibles effectifs de l’administration et la modicité des financements extérieurs aléatoires. Il est d’abord nécessaire de  répondre aux urgences : décrets à publier et à appliquer ; mise en oeuvre  systématique des avantages économiques prévus pour les communautés de base signataires des contrats de transfert de gestion. . . . ; sécurisation des espaces communs sous contrats de transfert de gestion. Il faut enfin et surtout faire de la valorisation conservatoire des ressources des produits forestiers ligneux et non ligneux le moteur du développement local.This paper presents a retrospective on the implementation of Malagasy environmental and forest policy between 1990 and 2013 on the basis of four laws, namely the Environmental Charter (Law 90-033 of 21 December 1990), GELOSE (Law 95-025 of 30 September 1996), the Forest Law (Law 97-017 of 8 August 1997) and the Protected Areas Code (Law 2001-005 of 11 February 2003). Twenty years after the adoption of the new forest policy, an assessment is possible. These texts have started to be applied but with disappointing results, primarily centered on the increase of protected area coverage. Nevertheless, important and positive changes have occurred. With decentralization, the reach of the law has increased day by day in communes through land offices, management transfer contracts, and positive experiences of decentralized forest control. Successful experiences of the economic valorization of forest resources (such as timber, fuelwood, raphia palm and essential oils), have also been gained within management transfers. It is therefore possible, in December 2013, to realistically envisage a strong revival of forest policy, even  accounting for permanent constraints such as the weakness of the forest administration and the uncertainty of external funding. It is first necessary to respond to urgent needs; to publish and apply un-finalized decrees, to systematically establish the economic benefits anticipated for the  community signatories of management transfer contracts, and to secure common property areas within management transfers. Most importantly, the sustainable economic valorization of woody and non - woody forest products should be used as a tool for local development

Caspase-generated fragment of the Met receptor favors apoptosis via the intrinsic pathway independently of its tyrosine kinase activity

The receptor tyrosine kinase Met and its ligand, the hepatocyte growth factor, are essential to embryonic development, whereas the deregulation of Met signaling is associated with tumorigenesis. While ligand-activated Met promotes survival, caspase-dependent generation of the p40 Met fragment leads to apoptosis induction – hallmark of the dependence receptor. Although the survival signaling pathways induced by Met are well described, the pro-apoptotic signaling pathways are unknown. We show that, although p40 Met contains the entire kinase domain, it accelerates apoptosis independently of kinase activity. In cell cultures undergoing apoptosis, the fragment shows a mitochondrial localization, required for p40 Met-induced cell death. Fulminant hepatic failure induced in mice leads to the generation of p40 Met localized also in the mitochondria, demonstrating caspase cleavage of Met in vivo. According to its localization, the fragment induces mitochondrial permeabilization, which is inhibited by Bak silencing and Bcl-xL overexpression. Moreover, Met silencing delays mitochondrial permeabilization induced by an apoptotic treatment. Thus, the Met-dependence receptor in addition to its well-known role in survival signaling mediated by its kinase activity, also participates in the intrinsic apoptosis pathway through the generation of p40 Met – a caspase-dependent fragment of Met implicated in the mitochondrial permeabilization process

Dynamics of Elastic Excitable Media

The Burridge-Knopoff model of earthquake faults with viscous friction is equivalent to a van der Pol-FitzHugh-Nagumo model for excitable media with elastic coupling. The lubricated creep-slip friction law we use in the Burridge-Knopoff model describes the frictional sliding dynamics of a range of real materials. Low-dimensional structures including synchronized oscillations and propagating fronts are dominant, in agreement with the results of laboratory friction experiments. Here we explore the dynamics of fronts in elastic excitable media.Comment: Int. J. Bifurcation and Chaos, to appear (1999