This volume comprises the proceedings of a NATO Advanced Study Institute (ASI) held at Geilo, Norway, 11-21 April 2005, the eighteenth ASI in a series held every two years since 1971. The objective of this ASI was to identify and discuss areas where synergism between modern physics and biology may be most fruitfully applied to the study of bioprocesses for molecular recognition, and of networks for converting molecular reactions into usable signals...