[JOINT FILING STATEMENT Dated: August 19, 2011 GRANITE GLOBAL VENTURES III L.P. Hany M. Nada Managing Director GRANITE GLOBAL VENTURES III L.L.C. Hany M. Nada Managing Director Hany M. Nada as Attorney-in-fact for Scott B. Bonham Hany M. Nada Hany M. Nada as Attorney-in-fact for Thomas K. Ng Hany M. Nada as Attorney-in-fact for Jixun Foo Hany M. Nada as] [CUSIP No. 90138A 10 3 1 NAMES OF REPORTING PERSONS 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) o (a) þ (b) 3 SEC USE ONLY 4 SOURCE OF FUNDS (SEE INSTRUCTIONS) WC 5]