1. University of Cagliari, Cagliari, Italy
2. University of Catania, Catania, Italy
3. University of Udine, Udine, Italy
4. University of Pisa, Pisa, Italy
5. University of Bari, Bari, Italy
6. Panic and Respiration Laboratory, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
7. University of L’Aquila, L’Aquila, Italy
8. University of Florence, Florence, Italy