April 16-18, 2010, Mini-Workshop: Differential Algebraic Geometry, CUNY Graduate Center and NYU Courant Institute.   Other recent events: Mar 29- Apr 02, 2010, Conference on Geometric and Differential Galois Theory, Centre International de Recontres Mathématiques, Luminy, France. Jan 13-16, 2010, Special Session on Differential Galois Theory and Group Representations: A tribute to Andy Magid, San Francisco, California. I coorganized this special session with James Carrell (University of British Columbia), Alex Lubotzky (Hebrew University of Jerusalem), Brian Parshall (University of Virginia) and Marius van der Put (University of Groningen). Oct 5, Invited Talk, Algebra Seminar, Department of Mathematics, Rutgers University, Piscataway, NJ. Oct 2, Invited Colloquium Talk, Center for Communications Research, Institute for Defense Analyses, Princeton, NJ. Sep 30, Invited Talk, Galois Theory Seminar, Department of Mathematics, University of Pennsylvania. Sep 22, Invited Talk, Algebra Seminar, Department of Mathematics, Yale University, New Haven, CT. Fall Semester, 2009, Visiting Scholar, Math Department, Penn University. Fall Semester, 2009, member of the Kolchin Seminar in Differential Algebra, at the Graduate Center of CUNY (three invited talks given). May 11--15, 2009, Satellite Workshop - Algebraic Theory of Difference Equations, University of Leeds, UK (one contributed talk given). April 14, 2009, Karcher Special Lecture, University of Oklahoma, Norman. Jan 5--8, 2009, Joint Mathematics Meetings, Washington, DC. November 13--16, 2008, DART III, Rutgers University at Newark, NJ. June 2--6, 2008, Contributed talk at the Workshop on Representation Theory, Geometry and Combinatorics, Berkeley, California. March 2008, One month visitor/member, MSRI, Berkeley, California. June 17--June 23, 2007: Visiting the Laboratoire d'Arithmétique et d'Algèbre, Université Jean Monnet, Saint-Etienne, France. June 19, Invited speaker at the Séminaire d'Arithmétique. May 19--June 17, 2007: Visiting Professor, IRMAR, Université de Rennes 1, Bretagne, France. May 23, Invited speaker, Séminaire de Calcul formel et Complexité, IRMAR May 13 -- 19, 2007: Invited speaker, Workshop on Arithmetic and Differential Galois Groups, Oberwolfach, Germany. April 14 -- 15, 2007: Invited Speaker at the Special Session on Differential Algebra and related topics, AMS Eastern Section Meeting, Stevens Institute of Technology, Hoboken, NJ. April 12 -- 13, 2007: Workshop in Differential Algebra and Related Topics (DART II), Rutgers University at Newark, Newark, NJ.