  New effects related to refraction of neutrinos in different media are
reviewed and implication of the effects to neutrino mass and mixing are
discussed. Patterns of neutrino masses and mixing implied by existing
hints/bounds are described. Recent results on neutrino mass generation are
presented. They include neutrino masses in SO(10) GUT's and models with
anomalous $U(1)$, generation of neutrino mass via neutrino-neutralino mixing,
models of sterile neutrino.
