Dear friends and colleagues, on Monday, 20 March 2017 from 2 to 3 pm Dr Changwei Xiong (Australian National University, Canberra) is giving a talk in the PDE Seminar on "GAP THEOREMS INVOLVING SECOND FUNDAMENTAL FORM: FROM CLOSED SURFACES TO OPEN SURFACES" An abstract is available at http://www.maths.usyd.edu.au/u/PDESeminar/abstracts17/xiong.xhtml The talk is in Carslaw 829 (Access Grid Room) at the University of Sydney. Everybody is invited to take part at the joint lunch with the guest speaker. We will meet at 12:15 pm on level 7 in Carslaw Building in front of the elevator. We also invite you to take part in the discussion afterwards in Carslaw Common Room 727. Kind regards, Daniel D and Daniel H P.S: If you know suitable speakers or want to give a talk yourself please let us know.