Éditeur(s) : HAL CCSD PeerJ
Résumé : International audience
Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators' diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach highlights a highly complex interaction web and demonstrates that levels of trophic partitioning among coral reef fishes have likely been underestimated. Therefore, we strongly encourage further empirical approaches to dietary studies prior to making assumptions of trophic equivalency in food web reconstruction. How to cite this article Leray et al. (2015), Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet. PeerJ 3:e1047
ISSN: 2167-8359

Droits : http://creativecommons.org/licenses/by/
hal-01174184
https://hal-univ-perp.archives-ouvertes.fr/hal-01174184
https://hal-univ-perp.archives-ouvertes.fr/hal-01174184/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01174184/file/peerj-1047.pdf
DOI : 10.7717/peerj.1047

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Energy dissipation is observed on seismic data when a wave propagates through a porous medium, involving different frequency regimes depending on the nature of rock and fluid types. We focus here on the role of partial fluid saturation in unconsolidated porous media, looking in particular at P-wave phase velocity and attenuation. The study consists in running an experiment in a sand-filled tank partially saturated with water. Seismic propagation in the tank is generated in the kHz range by hitting a steel ball on a granite plate. Seismic data are recorded by buried accelerometers and injecting or extracting water controls the partial saturation. Several imbibition/drainage cycles were performed between the water and gas residual saturations. A Continuous Wavelet Transform applied on seismic records allowed us to extract the direct P-wave at each receiver.We observe an hysteresis in phase velocities and inverse quality factors between imbibition and drainage. Phase velocities and inverse quality factors are then jointly inverted to get a final poro-visco-elastic model of the partially saturated sand that satisfactorily reproduces the data. The model formulation consists in generalizing the Biot theory to effective properties of the fluid and medium (permeability and bulk modulus) in order to properly explain the phase velocity variation as a function of the saturation. The strong level of attenuation measured experimentally is further explained by an anelastic effect due to grain to grain sliding, adding to Biot's losses. This study shows that fluid distribution at microscopic scale has strong influence on the attenuation of direct P-waves at macroscopic scale and confirms that seismic prospection may be a powerful tool for the characterization of transport phenomena in porous media.
ISSN: 0956-540X

hal-00779920
https://hal.archives-ouvertes.fr/hal-00779920
https://hal.archives-ouvertes.fr/hal-00779920/document
https://hal.archives-ouvertes.fr/hal-00779920/file/Barriere_et_al_HAL.pdf
DOI : 10.1111/j.1365-246X.2012.05691.x

Éditeur(s) : HAL CCSD
Résumé : International audience
Starting from a description of various generalized function algebras based on sequence spaces, we develop the general framework for considering linear problems with singular coefficients or non linear problems. Therefore, we prove functorial properties of those algebras and show how weak equalities, in the sense of various associations, can be described in this setting.
International Journal of Mathematics and Mathematical Sciencess

hal-00761083
https://hal.univ-antilles.fr/hal-00761083
https://hal.univ-antilles.fr/hal-00761083/document
https://hal.univ-antilles.fr/hal-00761083/file/0210249v1.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We build a class of codes using hermitian forms and the functional trace code. Then we give a general expression of the r-th minimum distance of our code and compute general bounds for the weight hierarchy by using exponential sums. We also get the minimum distance and calculate the r-th generalized Hamming weight dr in some special cases.
ISSN: 1071-5797

hal-00771922
https://hal.univ-antilles.fr/hal-00771922

Éditeur(s) : HAL CCSD
Résumé : International audience
Many emerging infectious diseases are caused by generalist pathogens that infect and transmit via multiple host species with multiple dissemination routes, thus confounding the understanding of pathogen transmission pathways from wildlife reservoirs to humans. The emergence of these pathogens in human populations has frequently been associated with global changes, such as socio-economic, climate or biodiversity modifications, by allowing generalist pathogens to invade and persist in new ecological niches, infect new host species, and thus change the nature of transmission pathways. Using the case of Buruli ulcer disease, we review how land-use changes, climatic patterns and biodiversity alterations contribute to disease emergence in many parts of the world. Here we clearly show that Mycobacterium ulcerans is an environmental pathogen characterized by multi-host transmission dynamics and that its infectious pathways to humans rely on the local effects of global environmental changes. We show that the interplay between habitat changes (for example, deforestation and agricultural land-use changes) and climatic patterns (for example, rainfall events), applied in a local context, can lead to abiotic environmental changes and functional changes in local biodiversity that favor the pathogen’s prevalence in the environment and may explain disease emergence.
ISSN: 2222-1751

Droits : http://creativecommons.org/licenses/by/
hal-01528488
http://hal.upmc.fr/hal-01528488
http://hal.upmc.fr/hal-01528488/document
http://hal.upmc.fr/hal-01528488/file/emi20177a.pdf
DOI : 10.1038/emi.2017.7

Éditeur(s) : HAL CCSD Cambridge Scientific Publishers Ltd
Résumé : International audience
https://hal.univ-antilles.fr/hal-01529538
Pointe-à-Pitre, Guadeloupe

ISBN : 1-904868-31-2
hal-01529538
https://hal.univ-antilles.fr/hal-01529538

Éditeur(s) : HAL CCSD European Geosciences Union (EGU)
Résumé : International audience
We consider here wind speed time series and the aggregate output wind power from a wind farm. We study their scaling statistics in the framework of fully developed turbulence and Kolmogorov's theory. We estimate their Fourier power spectra and consider their scaling properties in the physical space. We show that the atmospheric wind speed and the aggregate power output from a wind farm are intermittent and multifractal over a wide range of scales. The coupling between simultaneous data of the wind speed and aggregate power output is investigated through a joint multifractal description using the generalized correlation functions (GCFs). This multiscaling test is compatible with a linear relation between the wind speed and the aggregate power output fluctuations for timescales T ⩾ 103 s ≃ 15 min
ISSN: 1023-5809

hal-01527893
https://hal.archives-ouvertes.fr/hal-01527893
DOI : 10.5194/npg-21-379-2014

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We present generalizations of the KKM Principle and of the Kakutani-Fan-Glicksberg fixed point theorem adapted to the study of Nash equilibria in games without ordered preferences.
Journal of Mathematical Analysis and applications

hal-00699223
https://hal.archives-ouvertes.fr/hal-00699223

Éditeur(s) : HAL CCSD
Résumé : The midpoint method was previously used in the solving of equations and in this work, the aim is to adapt the theory to the set-valued analysis in order to approach solutions of generalized equations of the form 0_inf(x)+F(x). In particular, we show the existence and convergence fo sequences provided the second order derivative of the function f satisfies a Hölder condition, or a center-Hölder condition.
GDR MOA
Sainte-Anne, Guadeloupe

hal-00757686
https://hal.archives-ouvertes.fr/hal-00757686

Éditeur(s) : HAL CCSD
Résumé : International audience
Rencontres européennes d'Analyse Non Standard
Luminy - Marseille, France

hal-01535424
https://hal.univ-antilles.fr/hal-01535424

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
ISSN: 1065-2469

hal-01529516
https://hal.univ-antilles.fr/hal-01529516

Éditeur(s) : HAL CCSD
Résumé : The recent accumulation of genomic sequence data has shown that gene evolution is not strictly tree-Like. Many evolutionary processes, like exon shuffling, gene fusion or nonhomologous recombination remodel genes by creating composite structures that are made from parts with different evolutionary histories. The development of sequence similarity networks provides an analytical framework to study the impact of these processes on molecular evolution, by structuring the resemblance relationships between sequences and by formalizing, in terms of graph theory, the detection of composite genes (intransitive triplets) and gene families (clique minimal separators). The size of current data sets, typically several million sequences, has also required the development of new tools and methods: sequence comparison parallelization, large networks visualization with Louvain communities and large cycles identification. When applied to eukaryotic and viral genome data sets, these methods have shown that composite genes are found throughout cellular organisms and mobile genetic elements. Proportionally, composite genes are more numerous in eukaryotic genomes; in absolute number, they are more numerous in viruses. In the latter, composite genes functional distribution is biased (enrichment of genes families that are essential for the perpetuation of the viral cycle), and the various parts of composite genes sometimes even originate from the genetic material of different viral classes. More generally, the extent of combinatorial processes, by unravelling other evolutionary bonds than homology bonds in the strictest sense, legitimates a pluralistic study of similarity relationships between sequences.
L’accumulation récente de données de séquences génomiques a montré que l’évolution des gènes n’est pas strictement arborescente. De nombreux processus évolutifs, comme l’exon shuffling, la fusion de gènes ou la recombinaison illégitime remodèlent les gènes, créant des structures composites, formées de parties dont les histoires évolutives sont différentes. Le développement de réseaux de similarité de séquences fournit un cadre analytique permettant d’étudier l’impact de ces processus sur l’évolution moléculaire, en structurant les relations de ressemblance entre séquences et en formalisant en termes de graphes la détection de gènes (triplets intransitifs) et de familles de gènes (cliques minimales séparatrices) composites. La taille des jeux de données actuels, de l’ordre de plusieurs millions de séquences, a également requis le développement de nouveaux outils et méthodes : parallélisation des comparaisons de séquences, visualisation de très grands réseaux par simplification en communautés de Louvain et identification de grands cycles. Appliquées à des jeux de données de génomes eucaryotes et viraux, ces méthodes ont démontré la présence de gènes composites dans tout le vivant et les éléments génétiques mobiles. En proportion, les gènes composites sont plus nombreux dans les génomes eucaryotes ; en nombre absolu, ils sont plus nombreux à être portés par des virus. Chez ces derniers, la distribution fonctionnelle des gènes composites est biaisée (enrichissement dans les familles essentielles pour la perpétuation du cycle viral), et les éléments des gènes composites trouvent même parfois leurs origines dans le matériel génétique de classes virales différentes. Plus généralement, l’étendue des processus combinatoires, en révélant des liens évolutionnaires autres que les liens d’homologie au sens fort, justifie une étude pluraliste des relations de similarité entre séquences.
https://tel.archives-ouvertes.fr/tel-01127379

NNT : 2014PA066358
tel-01127379
https://tel.archives-ouvertes.fr/tel-01127379
https://tel.archives-ouvertes.fr/tel-01127379/document
https://tel.archives-ouvertes.fr/tel-01127379/file/2014PA066358.pdf

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The aim of this study is the approximation of a solution x* of a ganeralized equation 0 in f(x)+F(x) in Banach spaces, where f is a single-valued function whose second order Frechet derivative satisfies an Hölder condition and F stands for a set-valed map with closed graph. Using a fixed point theorem and the Aubin property of F, we show the existence and the superquadratic convergence of a sequence derived from a midpoint method.
ISSN: 0167-8019

hal-00642118
https://hal.archives-ouvertes.fr/hal-00642118

Éditeur(s) : HAL CCSD Tsing Hua University
Résumé : International audience
This paper deals with variational inclusions of the form : $0in varphi(z)+F(z)$ where $varphi$ is a single-valued function admitting a second order Fréchet derivative and $F$ is a set-valued map from $R^q$ to the closed subsets of $R^q$. In order to approximate a solution $bar z$ of the previous inclusion, we use an iterative scheme based on a multipoint method. We obtain, thanks to some semistability properties of $bar z$, local superquadratic or cubic convergent sequences
ISSN: 1607-2510

hal-00728816
https://hal.archives-ouvertes.fr/hal-00728816

Résumé : Au XXIème siècle, en France, en Martinique, au Québec, le monde du travail se caractérise encore par des inégalités professionnelles persistantes. La non mixité dans la fonction de direction générale ou autrement dit, la ségrégation verticale professionnelle dans l’entreprise serait-elle un invariant quels que soient les contextes ? Les référentiels culturels du dirigeant et du décideur demeurent encore masculins. Les représentations qui se sont construites sur les rôles sociaux des femmes et des hommes dans le travail se sont vite et durablement condensées en stéréotypes négatifs à l’égard des femmes.A partir de la théorie du noyau central d’Abric il semblait opportun de chercher à identifier les principaux déterminants qui ont présidé à la construction de ces stéréotypes. Ce noyau dur serait constitué de déterminismes historiques symboliques et sociaux. S’intéresser à la « déconstruction » des stéréotypes sexués en défaveur des femmes constitue un moyen de repenser l’action collective pour agir plus efficacement en matière de mixité professionnelle. En effet, plusieurs travaux ont montré que, sous certaines conditions, les éléments centraux d’une représentation pouvaient être sensibles à des informations venant les contredire. Réussir la mixité professionnelle entre les femmes et les hommes dans la fonction de direction générale des entreprises requiert, tant de la part de la politique gouvernementale que de celle des ressources humaines, des actions fortes relevant des enjeux de l’élimination des stéréotypes et de déconstruction du rôle social assigné à la femme depuis des millénaires.
In the 20th Century, in France, Martinique and Québec, the world of Work is still characterized by persistent professional disparities. Should the not-mixing be an invariant whatever the contexts, in the general managerial function, or in other words, the professional vertical segregation in the company ?The Manager’s and decider’s cultural reference tables remain still male. The representations built by themselves on the women and men social roles in work area are quickly and durably condensed in negative stereotypes against the women.From the theory of the central core of Abric (abric’score), it seems appropriate to try to identify the main determinants which presided over the construction of these stereotypes. This hard core would be constituted by symbolic and social historic determinism. Be interested in the "demolition" of the sexual stereotypes against the women establishes a way to rethink the collective action to act more effectively in regards to professional mixing. Indeed, several works showed that under certain conditions, the central elements of a representation could be sensitive to information coming to contradict them.To make a success of the professional mixing between the women and men in the general managerial function of companies requires so much on behalf of the government policy, a that of the human resources, strong actions raising stakes in the elimination of stereotypes and demolition of the social role assigned to the woman since millenniums.

http://www.theses.fr/2015AGUY0846/document

Éditeur(s) : HAL CCSD
Résumé : For ecology scientists, spatial statistics are a set of tools allowing characterization of the structure of a point set, for instance a map of trees in a forest plot. This structure is defined implicitly as a departure from complete spatial randomness (CSR), the result of a Poisson point process. Inhomogeneity of the process and non-independence of points are its causes. As they cannot be disentangled by analyzing the data, so-called "spatial concentration" or "aggregation" (evenness due to repulsion also exists but is actually rare) usually concerns non-independence while intensity is assumed as known. The literature of point processes and measures of spatial structures is reviewed to clarify concepts and choices. The purpose of this thesis was to produce methodological enhancements. Its main results are: * A test for the most used statistic, Ripley's K function, against the null hypothesis of CSR. It can replace Monte-Carlo simulations used until now in the literature. * An extension of K to inhomogeneous processes, within a typology of available statistics (absolute, relative and topographic measures). When data is available as number of objects per zones (say a number of tree in each forest plot) rather than their exact position, information theory is used to define a general framework allowing to characterize spatial structure (of species) and diversity (of plots) as two aspects of a single measure of inequality. This framework is applied to Shannon's index of biodiversity to derive a self-sufficient definition of beta diversity, its calculation independently from the difference between gamma and alpha diversity, and a statistical test of significance against the null hypothesis that plots are samples of the same community. The way is paved for other applications to measures of diversity and spatial structures. As a conclusion, it appears clear that pattern characterization tools are a first step to deal with ecological questionings. Their development is still a matter of research. Yet, they are far from sufficient to address ecological processes as point processes ignore the temporal aspect of object locations.
Les statistiques spatiales sont pour les écologues un ensemble d'outils permettant de caractériser la structure d'un semis de points, par exemple une carte représentant des emplacements des arbres dans une parcelle de forêt. Cette structure est définie implicitement comme un écart à semis complètement aléatoire, résultat d'un processus de Poisson. L'hétérogénéité du processus ponctuel dont le semis de points est une réalisation et la non-indépendance des points en sont les causes indiscernables, ce qui amène généralement à supposer l'intensité du processus connu et nommer " concentration spatiale " ou " agrégation " (la régularité spatiale est possible, mais rare en pratique) la non-indépendance. Une revue de la littérature des processus ponctuels et des mesures de structures spatiales est fournie pour clarifier les concepts et les choix. L'objectif de ce travail de thèse était de produire des améliorations méthodologiques. Ses résultats principaux sont : * L'établissement d'un test pour la principale statistique utilisée, la fonction K de Ripley, permettant de s'affranchir de la méthode de Monte-Carlo utilisée dans la littérature pour rejeter l'hypothèse nulle d'un processus complètement aléatoire. * L'extension de K aux processus hétérogènes, dans le cadre d'une typologie claire des statistiques (absolues, relatives, topographiques). Lorsque la position exacte des objets n'est pas connue, mais que des effectifs par zone sont disponibles (par exemple des nombres d'arbres par parcelle), la théorie de l'information est utilisée pour définir un cadre général permettant de caractériser la structure spatiale (des espèces dans les parcelles) et la diversité (des parcelles, en termes d'espèces) comme deux aspects d'une même mesure d'inégalité. Ce cadre est appliqué à l'indice de biodiversité de Shannon pour définir clairement la mesure de diversité bêta, son calcul direct indépendamment de la différence entre diversités gamma et alpha, et fournir un test statistique de non nullité. La voie est ouverte pour l'application à d'autres mesures de diversité et de structure spatiale. En conclusion, il semble clair que ces outils de caractérisation sont un premier pas pour traiter les questions écologiques, leur développement étant toujours du domaine de la recherche. Ils sont cependant très insuffisants pour répondre à des questions liées aux processus écologiques, assez éloignés des processus ponctuels qui ignorent l'aspect temporel de l'installation des objets.
https://pastel.archives-ouvertes.fr/pastel-00540327

NNT : 2010AGPT0075
pastel-00540327
https://pastel.archives-ouvertes.fr/pastel-00540327
https://pastel.archives-ouvertes.fr/pastel-00540327/document
https://pastel.archives-ouvertes.fr/pastel-00540327/file/13_Marcon2010.pdf

Éditeur(s) : HAL CCSD Éditions de la Maison des sciences de l'homme
Résumé : International audience
For over a century, the complementary nature of fishing and farming activities in the floodplain of the Rufiji River (Tanzania) has formed the basis of the economy in its villages. Starting in the 1970s, the fishery evolved from a seasonal activity practiced on foot during flooding and using traditional traps to year-round dugout canoe operated lake fisheries using nets.The paper analyses the drivers of this change. After having rejected the simplistic technocratic hypothesis that technical innovation equals progress, the paper examines the relevance of the productivity of the different fishing techniques in the light of the evolution of the role of fisheries in the village economy. During the change-over period, the national and international economy deprives the villages of their main habitual sources of cash income. In the absence of any alternative, fisheries imposed themselves as the unique source of cash income, a function they can only fulfil if practiced year-round and this can only be achieved using canoes and nets. However, the perception of the causes of these changes in the villages is differentiated. For those who initiated the change-over, and who are now of an advanced age, the main driver of the transition to nets was the empowerment of the youth versus the elders. Such an interpretation resonates well with the economic determinants. However, it requires considering the modernisation process as a contextualised multi-sided expression of market globalisation.
Depuis plus d’un siècle, l’économie des villages de la plaine inondable du Rufiji (Tanzanie) est fondée sur la complémentarité des activités agricoles et des activités halieutiques. À partir de la fin des années 1970, les pêches traditionnelles à la nasse, pratiquées à pied saisonnièrement lors de la crue annuelle, sont supplantées par les pêches embarquées (pirogues monoxyles) au filet dans les lacs, pratiquées elles toute l’année. L’article s’interroge sur les déterminants de cette substitution.Après avoir rejeté l’hypothèse techniciste vulgaire qui voudrait que l’innovation technique soit synonyme de progrès, la pertinence du critère de productivité des différentes techniques de pêche est examinée à la lumière de l’évolution de la place des activités halieutiques dans l’économie villageoise. Il apparaît qu’à partir de cette époque, l’évolution économique nationale et internationale prive les villageois de leurs principales ressources monétaires habituelles. En l’absence de toute alternative, la pêche s’impose alors comme unique source de revenu monétaire, une fonction qu’elle ne peut remplir qu’à condition d’être pratiquée tout au long de l’année, ce que seules les techniques au filet permettent. Cependant, les représentations villageoises des causes de la généralisation de la pêche au filet sont différentes. Pour ceux d’entre eux, aujourd’hui très âgés, qui furent les pionniers de cette innovation, c’est le souci d’émancipation des cadets vis-à-vis des aînés qui aurait été le moteur de l’adoption de techniques de pêche au filet. Ce point de vue entre en résonance avec les déterminations économiques à condition de considérer le processus de modernisation comme manifestation multiforme contextualisée de la mondialisation marchande.
ISSN: 0248-6016

hal-01344410
https://hal.univ-antilles.fr/hal-01344410
https://hal.univ-antilles.fr/hal-01344410/document
https://hal.univ-antilles.fr/hal-01344410/file/Pauletal2015Version_Def.pdf

Éditeur(s) : HAL CCSD European Geosciences Union (EGU)
Résumé : International audience
We consider here wind speed time series and the aggregate output wind power from a wind farm. We study their scaling statistics in the framework of fully developed turbulence and Kolmogorov's theory. We estimate their Fourier power spectra and consider their scaling properties in the physical space. We show that the atmospheric wind speed and the aggregate power output from a wind farm are intermittent and multifractal over a wide range of scales. The coupling between simultaneous data of the wind speed and aggregate power output is investigated through a joint multifractal description using the generalized correlation functions (GCFs). This multiscaling test is compatible with a linear relation between the wind speed and the aggregate power output fluctuations for timescales T > 103 s ' 15min.
ISSN: 1023-5809

hal-00958490
https://hal.archives-ouvertes.fr/hal-00958490
DOI : 10.5194/npg-21-379-2014

Éditeur(s) : HAL CCSD
Résumé : International audience
We deal with a perturbed version of a Hummel-Seebeck type method to approximate a solution of variational inclusions of the form : 0 ∈ Φ(z) + F(z) where Φ is a single-valued function twice continuously Fréchet differentiable and F is a set-valued map from Rn to the closed subsets of Rn. This framework is convenient to treat in a unified way standard sequential quadratic programming, its stabilized version, sequential quadratically constrained quadratic programming, and linearly constrained Lagrangian methods (see [1]). We obtain, thanks to some semistability and another property (which is close to the hemistability) of the solution z ̄ of the previous inclusion, the local existence of a sequence that is superquadratically or cubically convergent.
ISSN: 2518-3680

hal-01630560
https://hal.archives-ouvertes.fr/hal-01630560
DOI : 10.22606

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
With the help of differential algebras of(C,Ep)-type, we construct an algebra of generalized functions which allows us to solve a Gourmet problem with irregular data. For this problem, we perform a qualitative study when the data are Dirac functions.
ISSN: 1065-2469

hal-01545673
https://hal.archives-ouvertes.fr/hal-01545673