We prove that every algebraic curve X/Q is birational over C to a Teichmüller curve. keywords: algebraic curve, mapping class group, Teichmüller curve, Veech group. MSC code: 32G15, 37D40.

the acute ecotoxicity of a set of mixture samples (washing powders, wastes, fuel extracts etc.) was assessed using four acute ecotoxicity assays with aquatic organisms (daphnia magna, poecilia reticulata, artemia salina and desmodesmus subspicatus). the experimental concentration-response curves were fitted by seven two-parameter sigmoid equations using non-linear regression. the regression per...