Commutative algebra : 150 years with Roger and Sylvia Wiegand : combined proceedings: Second International Meeting Commutative Algebra and Related Areas (SIMCARA), July 22-26, 2019, Universidade de São Paulo, São Carlos, Brazil, AMS Special Session Commutative Algebra: In Celebration of the 15th Birthday of Roger and Sylvia Wiegand, September 14-15, 2019, University of Wisconsin-Madison, Wisconsin / Nicholas R. Baeth, Thiago H. Freitas, Graham J. Leuschke, Victor H. Jorge Pérez, editors