In this photo released by the official website of the office of the Iranian Presidency, Iran's President Hassan Rouhani, second right, points a UV-Index Monitoring System, a device to measure the level of the ultraviolet radiation (UV), as he unveils it in a ceremony in Tehran, Iran, Sunday, May 11, 2014. Rouhani said Sunday his country has nothing to offer except transparency in nuclear talks with world powers, rebuffing hard-liners as negotiators seek a final deal over the Islamic Republic's contested program. He is accompanied by Vice President for science and technology affairs Sorena Sattari, right, and Health Minister Hassan Hashemi. (AP Photo/ Iranian Presidency Office, Mohammad Berno)