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

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

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

Spatiotemporal Chaos, Localized Structures and Synchronization in the Vector Complex Ginzburg-Landau Equation

We study the spatiotemporal dynamics, in one and two spatial dimensions, of two complex fields which are the two components of a vector field satisfying a vector form of the complex Ginzburg-Landau equation. We find synchronization and generalized synchronization of the spatiotemporally chaotic dynamics. The two kinds of synchronization can coexist simultaneously in different regions of the space, and they are mediated by localized structures. A quantitative characterization of the degree of synchronization is given in terms of mutual information measures.Comment: 6 pages, using bifchaos.sty (included). 7 figures. Related material, including higher quality figures, could be found at http://www.imedea.uib.es/PhysDept/publicationsDB/date.html . To appear in International Journal of Bifurcation and Chaos (1999

Collective Motion of Self-Propelled Particles with Memory

International audienceWe show that memory, in the form of underdamped angular dynamics, is a crucial ingredient for the collective properties of self-propelled particles. Using Vicsek-style models with an Ornstein-Uhlenbeck process acting on angular velocity, we uncover a rich variety of collective phases not observed in usual overdamped systems, including vortex lattices and active foams. In a model with strictly nematic interactions the smectic arrangement of Vicsek waves giving rise to global polar order is observed. We also provide a calculation of the effective interaction between vortices in the case where a telegraphic noise process is at play, explaining thus the emergence and structure of the vortex lattices observed here and in motility assay experiments

Chaos induced coherence in two independent food chains

Coherence evolution of two food web models can be obtained under the stirring effect of chaotic advection. Each food web model sustains a three--level trophic system composed of interacting predators, consumers and vegetation. These populations compete for a common limiting resource in open flows with chaotic advection dynamics. Here we show that two species (the top--predators) of different colonies chaotically advected by a jet--like flow can synchronize their evolution even without migration interaction. The evolution is charaterized as a phase synchronization. The phase differences (determined through the Hilbert transform) of the variables representing those species show a coherent evolution.Comment: 5 pages, 5 eps figures. Accepted for publication in Phys. Rev.

Effect of TiO2 addition on structure, solubility and crystallisation of phosphate invert glasses for biomedical applications

NOTICE: this is the author’s version of a work that was accepted for publication in JOURNAL OF NON-CRYSTALLINE SOLIDS. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in JOURNAL OF NON-CRYSTALLINE SOLIDS, [VOL 356, ISSUE 44-49, (2001)] DOI: 10.1016/j.jnoncrysol.2010.03.02

The Complex Ginzburg-Landau Equation in the Presence of Walls and Corners

We investigate the influence of walls and corners (with Dirichlet and Neumann boundary conditions) in the evolution of twodimensional autooscillating fields described by the complex Ginzburg-Landau equation. Analytical solutions are found, and arguments provided, to show that Dirichlet walls introduce strong selection mechanisms for the wave pattern. Corners between walls provide additional synchronization mechanisms and associated selection criteria. The numerical results fit well with the theoretical predictions in the parameter range studied.Comment: 10 pages, 9 figures; for related work visit http://www.nbi.dk/~martine

ROCKETSHIP: a flexible and modular software tool for the planning, processing and analysis of dynamic MRI studies

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising technique to characterize pathology and evaluate treatment response. However, analysis of DCE-MRI data is complex and benefits from concurrent analysis of multiple kinetic models and parameters. Few software tools are currently available that specifically focuses on DCE-MRI analysis with multiple kinetic models. Here, we developed ROCKETSHIP, an open-source, flexible and modular software for DCE-MRI analysis. ROCKETSHIP incorporates analyses with multiple kinetic models, including data-driven nested model analysis. Results: ROCKETSHIP was implemented using the MATLAB programming language. Robustness of the software to provide reliable fits using multiple kinetic models is demonstrated using simulated data. Simulations also demonstrate the utility of the data-driven nested model analysis. Applicability of ROCKETSHIP for both preclinical and clinical studies is shown using DCE-MRI studies of the human brain and a murine tumor model. Conclusion: A DCE-MRI software suite was implemented and tested using simulations. Its applicability to both preclinical and clinical datasets is shown. ROCKETSHIP was designed to be easily accessible for the beginner, but flexible enough for changes or additions to be made by the advanced user as well. The availability of a flexible analysis tool will aid future studies using DCE-MRI