In this note we introduce the notion of a Poisson smooth structure on a
symplectic stratified space. We show that under a mild condition many
properties of a symplectic manifold can be extended to a symplectic stratified
space, e.g. the existence and uniqueness of a Hamiltonian flow, the isomorphism
between the Brylinski-Poisson homology and the de Rham homology, the Hodge
structure on a symplectic stratified space. We give many examples of symplectic
stratified spaces satisfying these properties.
Any oriented 4-dimensional real vector bundle is naturally a line bundle over
a bundle of quaternion algebras. In this paper we give an account of modules
over bundles of quaternion algebras, discussing Morita equivalence,
characteristic classes and K-theory. The results have been used to describe
obstructions for the existence of almost quaternionic structures on
8-dimensional Spinc manifolds and may be of some interest, also, in
quaternionic and algebraic geometry.