Videotape sculptures and war trauma paintings make Turner prize shortlist

Nnena Kalu, Mohammed Sami, Rene Matić and Zadie Xa nominated for £25,000 contemporary art prizeAn artist who creates swirling sculptures out of fabric and old videocassette tape, and another who installed huge paintings evoking wartime trauma in the genteel rooms of Blenheim Palace, have been shortlisted for this year’s Turner prize.Nnena Kalu, a Scottish-born, London-based artist, and Mohammed Sami, who fled his native Iraq as a refugee, have been chosen alongside Rene Mati