Observation and inverse problems in coupled cell networks

A coupled cell network is a model for many situations such as food webs in ecosystems, cellular metabolism, economical networks... It consists in a directed graph $G$, each node (or cell) representing an agent of the network and each directed arrow representing which agent acts on which one. It yields a system of differential equations $\dot x(t)=f(x(t))$, where the component $i$ of $f$ depends only on the cells $x_j(t)$ for which the arrow $j\rightarrow i$ exists in $G$. In this paper, we investigate the observation problems in coupled cell networks: can one deduce the behaviour of the whole network (oscillations, stabilisation etc.) by observing only one of the cells? We show that the natural observation properties holds for almost all the interactions $f$

Palaeolithic cave art in West France: an exceptional discovery: the Margot Cave (Mayenne)

From sites such as Lascaux, Chauvet and Cosquer in the south of France (Perigord, Ardèche and ouches-du-Rhône) and Altamira in Spain (Cantabria), cave art in the south of Europe is very well-known. But for a long time, cave art has been far less commonly encountered in the North. This situation is changing with a series of recent discoveries in England (Bahn et al. 2003), in France (Baffier & Girard 1996) and in Germany (Conard & Uermann 2000). It has strengthened the group of the seven decorated caves already discovered in Normandy, Central France and in Mayenne (Pigeaud 2004), to which we can include the fragments of rock painting from the cave of Geissenklösterle, in Germany (Hahn 1986). In this paper, we are presenting the discovery in July 2005 of Palaeolithic engravings and paintings in the Margot cave (Mayenne). This is the first decorated cave identified in Western France since 1967 and the thirteenth known in Northern Europe. The radiocarbon dating from some of these sites and the stylistic attributions of others authorize us to define a cultural group at the end of the Upper Palaeolithic. The period (around 12 000 BP) corresponds to a time when climatic conditions facilitated the progression of prehistoric humans to the North (Plumet 2004). Domaine

Palaeolithic cave art in West France: an exceptional discovery: the Margot Cave (Mayenne)

International audienceFrom sites such as Lascaux, Chauvet and Cosquer in the south of France (Perigord, Ardèche and ouches-du-Rhône) and Altamira in Spain (Cantabria), cave art in the south of Europe is very well-known. But for a long time, cave art has been far less commonly encountered in the North. This situation is changing with a series of recent discoveries in England (Bahn et al. 2003), in France (Baffier & Girard 1996) and in Germany (Conard & Uermann 2000). It has strengthened the group of the seven decorated caves already discovered in Normandy, Central France and in Mayenne (Pigeaud 2004), to which we can include the fragments of rock painting from the cave of Geissenklösterle, in Germany (Hahn 1986). In this paper, we are presenting the discovery in July 2005 of Palaeolithic engravings and paintings in the Margot cave (Mayenne). This is the first decorated cave identified in Western France since 1967 and the thirteenth known in Northern Europe. The radiocarbon dating from some of these sites and the stylistic attributions of others authorize us to define a cultural group at the end of the Upper Palaeolithic. The period (around 12 000 BP) corresponds to a time when climatic conditions facilitated the progression of prehistoric humans to the North (Plumet 2004)

The Margot Cave (Mayenne): A New Palaeolithic Sanctuary in West France

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