Evidence for the Universal Scaling Behaviour of a Freely Relaxing DNA Molecule

Relaxation measurements on a fluorescently labelled free DNA molecule after stretching by a Poiseuille flow in a capillary vessel reveal universal scaling features: at intermediate times the scaling exponent of the decay law for the molecule length as a function of time is found to be 0.51 +/- 0.05. This law is in agreement with the prediction of the Brochard-Wyart "stem and flower" model for the relaxation of a stretched polymer chain.Molecular and Cellular BiologyPhysic

A dynamo driven by zonal jets at the upper surface: Applications to giant planets

We present a dynamo mechanism arising from the presence of barotropically unstable zonal jet currents in a rotating spherical shell. The shear instability of the zonal flow develops in the form of a global Rossby mode, whose azimuthal wavenumber depends on the width of the zonal jets. We obtain self-sustained magnetic fields at magnetic Reynolds numbers greater than 1000. We show that the propagation of the Rossby waves is crucial for dynamo action. The amplitude of the axisymmetric poloidal magnetic field depends on the wavenumber of the Rossby mode, and hence on the width of the zonal jets. We discuss the plausibility of this dynamo mechanism for generating the magnetic field of the giant planets. Our results suggest a possible link between the topology of the magnetic field and the profile of the zonal winds observed at the surface of the giant planets. For narrow Jupiter-like jets, the poloidal magnetic field is dominated by an axial dipole whereas for wide Neptune-like jets, the axisymmetric poloidal field is weak.Comment: published in Icaru

Tara up-regulates E-cadherin transcription by binding to the Trio RhoGEF and inhibiting Rac signaling

In the absence of Tara, Trio binds to E-cadherin and increases activation of the E-cadherin transcriptional repressor Tbx3

Evolutionary origin of synapses and neurons – Bridging the gap

The evolutionary origin of synapses and neurons is an enigmatic subject that inspires much debate. Non-bilaterian metazoans, both with and without neurons and their closest relatives already contain many components of the molecular toolkits for synapse functions. The origin of these components and their assembly into ancient synaptic signaling machineries are particularly important in light of recent findings on the phylogeny of non-bilaterian metazoans. The evolution of synapses and neurons are often discussed only from a metazoan perspective leaving a considerable gap in our understanding. By taking an integrative approach we highlight the need to consider different, but extremely relevant phyla and to include the closest unicellular relatives of metazoans, the ichthyosporeans, filastereans and choanoflagellates, to fully understand the evolutionary origin of synapses and neurons. This approach allows for a detailed understanding of when and how the first pre- and postsynaptic signaling machineries evolved

Evolutionary origin of synapses and neurons - Bridging the gap

The evolutionary origin of synapses and neurons is an enigmatic subject that inspires much debate. Non-bilaterian metazoans, both with and without neurons and their closest relatives already contain many components of the molecular toolkits for synapse functions. The origin of these components and their assembly into ancient synaptic signaling machineries are particularly important in light of recent findings on the phylogeny of non-bilaterian metazoans. The evolution of synapses and neurons are often discussed only from a metazoan perspective leaving a considerable gap in our understanding. By taking an integrative approach we highlight the need to consider different, but extremely relevant phyla and to include the closest unicellular relatives of metazoans, the ichthyosporeans, filastereans and choanoflagellates, to fully understand the evolutionary origin of synapses and neurons. This approach allows for a detailed understanding of when and how the first pre- and postsynaptic signaling machineries evolved

Migrants et protestantisme au xixe siècle

Le 28 septembre 1819, le maire du Havre écrivait au sous-préfet : « D’ancienne origine, de vrai et réel domicile, il y a très peu de familles protestantes en cette ville – peut-être pas deux cents individus de tout âge et de tout sexe.« Cependant, après l’édit du Roi Louis XVI qui accordait à tous ses sujets le libre exercice des différents cultes, quelques familles ou autres personnes, de la religion protestante, voulant jouir de ce bienfait, firent établir un temple de cette communion dans ..

Protestants, culture et société en Normandie : XVIIIe-XIXe siècles. Un chercheur et ses recherches

Manneville Philippe. Protestants, culture et société en Normandie : XVIIIe-XIXe siècles. Un chercheur et ses recherches. In: Études Normandes, 40e année, n°3, 1991. Normands dans l'histoire. pp. 69-78

Dommage... Catherine Grisel, Le Duché de Normandie et son rattachement à la couronne de France, Horvath, 1988

Manneville Philippe. Dommage... Catherine Grisel, Le Duché de Normandie et son rattachement à la couronne de France, Horvath, 1988. In: Études Normandes, 39e année, n°1, 1990. Culture, politiques. p. 84