Simplify the following text for a Grade 8 native English-speaking person.
Original: Liu Xiaobo ( pronunciation : ; born 28 December 1955 ) is a Chinese literary critic , writer , professor , and human rights activist who called for political reforms and the end of communist one-party rule in the People 's Republic of China ( PRC ) .
Simplified: Liu Xiaobo was born 28 December 1955 . He is a Chinese intellectual , writer , and human rights activist and a political prisoner in China .