It's a bland term for something very powerful - how things translate, migrate, relate to audiences, sites and context in different ways. Last year I was invited by Yanki Lee of Exhibit Gallery in London and the RCA to contribute some text and interview Nadav Kander the photographer who had spent some time travelling along the Yangtze River travelling from mouth to source taking images of an extraordinary landscape and context shifting perilously almost beyond the scope of the imagination.In the interview he spoke of how he visited the landscape with 'an empty mind' and sought to respond to what he found felt and saw there in a country he felt was 'mimicking the worst of the west'.  The work became part of a touring exhibition in China last summer called Constant Stream. Kander - who is also the photographer behind the exhibition Obama's People -  'http://www.obamaspeopleexhibition.com/ - justly won the prestigious Prix Pictet  - http://www.prixpictet.com/ - for Environmentally engaged Photography in Paris last November - and you can hear our interview  and see some of his enthralling pictures now at www.youtube.com/user/NadavKanderTube. In this he reflects on how a sense of the sublime suffused his encounter with the river and its changes, both on human and environmental scale,