Mirror symmetry breaking through an internal degree of freedom leading to directional motion

We analyze here the minimal conditions for directional motion (net flow in phase space) of a molecular motor placed on a mirror-symmetric environment and driven by a center-symmetric and time-periodic force field. The complete characterization of the deterministic limit of the dissipative dynamics of several realizations of this minimal model, reveals a complex structure in the phase diagram in parameter space, with intertwined regions of pinning (closed orbits) and directional motion. This demonstrates that the mirror-symmetry breaking which is needed for directional motion to occur, can operate through an internal degree of freedom coupled to the translational one.Comment: Accepted for publication in Phys. Rev.

Canids as persons: Early Neolithic dog and wolf burials, Cis-Baikal, Siberia

Interpretations of dog burials made by ancient foraging groups have tended to be based upon our own relationships with such animals and modern western cosmological and ontological concepts. Osteological studies of early dogs often focus only on issues of taxonomy, and as a result very little is known about these animals' life histories. Eastern Siberia has produced many Holocene dog burials, but these are typically not well described and the explanatory frameworks provided for them are very underdeveloped. Here we examine in detail two Cis-Baikal canid burials, one of a wolf and the other a dog, both in large Middle Holocene hunter-gatherer cemeteries. We link the mortuary treatment of these animals to other cultural practices, particularly the treatment of the human dead, and broader patterns in Northern human-animal relationships. This interpretive model is combined with detailed osteobiographies for the canids and contextual information for these and other dogs and wolves from Middle Holocene Cis-Baikal. It is argued that canids here were understood and treated in a variety of ways. We suggest that some animals with unique histories were known as distinct persons with 'souls' and because of this at death required mortuary rites similar to those of their human counterparts. © 2011 Elsevier Inc.Peer Reviewe

Zooarchaeological record of the last hunter-gatherers of the steppe region of Eastern Europe

International audienc

Zooarchaeological record of the last hunter-gatherers of the steppe region of Eastern Europe

International audienc

Subsistence strategies and the origin of early Neolithic community in the lower Don River valley(Rakushechny Yar site, early/middle 6th millennium cal BC): First results

International audienc

Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs

The geographic and temporal origins of the domestic dog remain controversial, as genetic data suggest a domestication process in East Asia beginning 15,000 years ago, whereas the oldest doglike fossils are found in Europe and Siberia and date to >30,000 years ago. We analyzed the mitochondrial genomes of 18 prehistoric canids from Eurasia and the New World, along with a comprehensive panel of modern dogs and wolves. The mitochondrial genomes of all modern dogs are phylogenetically most closely related to either ancient or modern canids of Europe. Molecular dating suggests an onset of domestication there 18,800 to 32,100 years ago. These findings imply that domestic dogs are the culmination of a process that initiated with European hunter-gatherers and the canids with whom they interacted.Peer reviewe