This issue of the European Biophysics Journal contains seven articles based on lectures presented at the XX Meeting of the Italian Society for Pure and Applied Biophysics (Societa Italiana di Biofisica Pura e Applicata, SIBPA), held in Arcidosso (Grosseto, Italy) from 11th to 14th September 2010. The XX meeting of the SIBPA marked a special anniversary for Italian biophysics, as Franco Gambale explained to the audience. The young Italian biophysicists in the audience learnt that use of the term ‘‘biophysics’’ started in the nineteensixties within physics Institutes. As a matter of fact, the basic question in biophysics had already been introduced in 1944 by the winner of the Nobel prize for physics Erwin Schrodinger in his pioneering book ‘‘What is life?’’. By 1950, as many as 200 research centers all around the world had already adopted the word biophysics in their name and had started to investigate living matter to answer Schrodinger’s question ‘‘How can the events in space and time which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?’’. Biophysics research in Italy started playing a role mainly because of the forward-looking activity of the Italian scientists Antonino Borsellino, Adriano Gozzini, and Mario Ageno, physics professors at Genoa, Pisa, and Rome Universities, respectively. Indeed, as early as 1959, Professor Antonino Borsellino organized a series of ‘‘Conferences on Biophysics and Biochemistry’’ in Genoa and, in 1963, the first Italian National Congress of Biophysics in Rome. In 1960 Borsellino also promoted the creation of the Italian Society for Pure and Applied Biophysics, but, unfortunately, owing to a series of impediments, the Society was finally established only in 1973 with Borsellino as its first President. Borsellino also promoted the participation of Italian biophysicists in the ‘‘first’’ International Congress on Biophysics held in Stockholm, Sweden, from July 31st to August 4th 1961, on the initiative of the International Union of Experimental and Theoretical Physics. This was the first meeting gathering biophysicists from around the world. The International Union of Pure and Applied Biophysics was formed and it decided to convene congresses once every three years. Today, therefore, it seems very appropriate to celebrate in this issue the XX SIBPA Congress and 50 years from the first International Biophysics meeting. The Stockholm agenda included: (1) mathematical modeling of biophysical phenomena; (2) new methods in biophysics (laser technology and others); (3) membrane biophysics and (4) vital problems of the molecular bases of virus replication. In some respects, these topics, in an updated version, were still part of the debate within the XX SIBPA meeting dealing with: (1) theories, models, and computational methods in biophysics, (2) spectroscopy and microscopy for biophysics and medical physics, and (3) molecular, cellular, and sensory biophysics. The article presented by Gerardo Abbandonato et al. reports the interesting cis– trans photoisomerization of two butenolide and two pyrrolinone derivatives sharing close structural relationships with the auto-fluorescent protein (AFP) family. The photoinduced alterations of the physicochemical properties of organic molecules are increasingly being investigated with D. Giacomazza (&) Consiglio Nazionale delle Ricerche, Istituto di Biofisica (Palermo Research Division), Via Ugo La Malfa, 153-90146 Palermo, Italy e-mail: daniela.giacomazza@pa.ibf.cnr.it