In an effective classroom students should not only know what they are doing, they should also know why and how.
by Harry K. Wong

My talks at IMPA (streaming videos)

Geometry of Gelfand-Cetlin integrable system (Conservative dynamics and symplectic geometry  2009):

http://strato.impa.br/videos/workshop_geometry/geometry_070809_03.avi

Dynamics on Poisson manifolds (Poisson 2010):

http://strato.impa.br/videos/poisson/poisson_26072010_nguyen.flv

(now that I listened to my own talk at IMPA, I found that my English was really horrible !)

For all video lectures recorded by IMPA:

http://video.impa.br