Resonant Scattering of Ultracold Atoms in Low Dimensions

Low energy scattering amplitudes for two atoms in one- and two-dimensional atomic wave guides are derived for short range isotropic and resonant interactions in high partial wave channels. Taking into account the finite width of the resonance which was neglected in previous works is shown to have important implications in the properties of the confinement induced resonances. For spin polarized fermions in quasi-1D wave guides it imposes a strong constraint on the atomic density for achieving the Fermi Tonks Girardeau gas. For a planar wave guide, the charateristics of the 2D induced scattering resonances in $p$- and d-wave are determined as a function of the 3D scattering parameters and of the wave guide frequency

The three different phases in the dynamics of chemical reaction networks and their relationship to cancer

We investigate the catalytic reactions model used in cell modeling. The reaction kinetic is defined through the energies of different species of molecules following random independent distribution. The related statistical physics model has three phases and these three phases emerged in the dynamics: fast dynamics phase, slow dynamic phase and ultra-slow dynamic phase. The phenomenon we found is a rather general, does not depend on the details of the model. We assume as a hypothesis that the transition between these phases (glassiness degrees) is related to cancer. The imbalance in the rate of processes between key aspects of the cell (gene regulation, protein-protein interaction, metabolical networks) creates a change in the fine tuning between these key aspects, affects the logics of the cell and initiates cancer. It is probable that cancer is a change of phase resulting from increased and deregulated metabolic reactions.Comment: 5 pages, 2 figures, EPL, in pres

Le cancer, une maladie de l'environnement

Le bilan de la lutte contre la cancer est ambigu. Des succès significatifs ont été enregistrés , notamment chez l'enfant et l'adolescent. En 1950, aux Etats-Unis, mille neuf cents enfants de moins de cinq ans mouraient d'un cancer. Leur nombre a diminué de plus de moitié. La chimiothérapie a transformé chez l'enfant le pronostic de la leucémie aiguë ou celui du cancer du rei

The metabolic advantage of tumor cells

1- Oncogenes express proteins of "Tyrosine kinase receptor pathways", a receptor family including insulin or IGF-Growth Hormone receptors. Other oncogenes alter the PP2A phosphatase brake over these kinases