Foundations on Natural and Artificial Computation 4th International Work-Conference on the Interplay Between Natural and Artificial Computation, IWINAC 2011, La Palma, Canary Islands, Spain, May 30 - June 3, 2011. Proceedings, Part I - Ferrández, José Manuel; Álvarez Sánchez, José Ramón; Paz, Félix de la; Toledo, F. Javier (Springer Berlin Heidelberg, 2011)