Academics and students have paid tribute to Liu Haolin, a leading computer scientist who died at the age of 37 after a sudden illness. An obituary published online said that Liu, a professor at Xiangtan University in the central province of Hunan, had died in a hospital in Changsha on Saturday. The obituary added that a memorial ceremony had been held the following day in the neighbouring city of Ningxiang. His university also published its own obituary and changed his profile picture on its...