The US is trying to mediate in a row over Ethiopia's Renaissance Dam on the Blue Nile. The project has led to a dispute with Egypt over the availability of water for the country. Nader Nour el-Din is a soil and water expert at Cairo University, and says there's a very real fear of food shortages in the future. We get a sense of Ethiopia's perspective from one of the country's most prominent business leaders, Zemedeneh Negatu, chairman of the Fairfax Africa Fund. And the BBC's Emmanuel Igunza discusses the likelihood of a breakthrough in the US-mediated talks. Also in the programme, Google has struck a deal with healthcare provider Ascension in the United States, giving it access to the medical data of millions of Americans. We hear from Kenneth Cukier, author of the book Big Data that whilst some have expressed privacy concerns, other say the initiative could bring the power of supercomputers to improve our health. Plus in the first of a series of interviews with senior figures in political parties ahead of next month's general election in the UK, we talk to Richard Tice, chairman of the Brexit Party, which was set up to push for an end to close ties with the EU.