Arnold's seminar December 12, 2000 S.Ponomarev Algebraic and symplectic geometry in dimension 4 (after P.Biran) This talk is based on the papers by P.Biran and coauthors about the interplay between symplectic and algebraic geometry that grew out of his work on symplectic packings. See the abstract of V.I.Arnold's talk (September 12, 2000).