Scientific rationale:

The conference will be devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies  formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM  physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.