Sheffield researchers claim expressing gratitude can bring benefits for health, empathy, self-esteem, reduced aggression and better sleep.  Dr Chris Blackmore and Dr Fusida Siros from the University of Sheffield are behind the idea of Good News Friday, encouraging the public to declare their thanks for something, whether big, small, personal or universal. A Wall of Gratitude has been set up in the Moor to collect declarations from the public. Baillor Jalloh reports for Sheffield Live!