Parameter dependence of solutions of classes of quasi-linear elliptic and parabolic differential equations.- Some applications of the method of super and subsolutions.- Multiple solutions of a bifurcation problem.- On nonlinear eigenvalue problems which extend into free boundaries problems.- aux theories statistiques de la turbulence pleinement developpee.- Experimental study of the mechanism of a new hydrodynamical instability observed at some interfaces between immiscible liquids.- Remarques sur un probl¿ de valeurs propres non lin¿res faisant intervenir des fonctions non diff¿ntiables.- Solar flares: A non linear eigenvalue problem in an unbounded domain.- Bifurcation of invariant tori in R3.- Pattern formation and wave propagation in the s-a system.- Variation d'un point de retournement par rapport au domaine.- Dynamic Pade' approximant and behavior singularities in nonlinear physico-chemical systems.- Remarks on a non linear equation arising in population genetics.- Triplets de solutions d'une equation aux derivees partielles elliptique non lineaire.