Changes in Advisors and White House Staff Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email President Barack Obama arrives to address the Millennium Development Goals Summit at the United Nations headquarters in New York, September 22, 2010. ( EMMANUEL DUNAND/AFP / Getty ) Produced by Hsi-Chang Lin Produced by PRI and WNYC