Alison J Dicker1, James D Chalmers2. 1. Scottish Centre for Respiratory Research, University of Dundee, Ninewells Hospital & Medical School, Dundee, Reino Unido. 2. Scottish Centre for Respiratory Research, University of Dundee, Ninewells Hospital & Medical School, Dundee, Reino Unido. Electronic address: jchalmers@dundee.ac.uk.