In August 2007 Alexander Shnirelman or Sasha (Russia, Israel, UK, France, now Concordia University, Canada) visited Recife on André Toom's invitation and gave two talks with a common title: "The Mystery of 2-dimensional ideal incompressible fluid" at the department of statistics of UFPE. The first talk was theoretical, the second talk was about problems. Abstract of the talk Extended abstract of the talk On the left side - picture of a street in Montreal by Alla, Sasha's wife.

On the left side - photo made by A. Toom after the second talk. From left to right: Alexander Shnirelman, Renato J. Cintra, Klaus Leite Pinto Vasconcellos, Calitéia Santana de Sousa, Cícero Carlos Ramos de Brito, Alice Lemos de Morais.