Acknowledgements: I would like to express my sincere thanks and gratitude to the following friends and colleagues for their contribution in improving the quality of this portal, and for providing reprints and useful comments: A. Apostolov; A. Brancelj; M. C. Bruno; S. Conroy-Dalton; V. Cottarelli; D. Defaye; F. Fiers; D. P. Galassi; H. Gheeradyn; S. E. Gómez-Noguera; P. Corgosinho; M. Holynska; R. Huys; V. Monchenko; T. Karanovic; P. M. Martinez-Arbizu; J.W. Reid; C. E. F. Rocha; S. Seifried; F. Stoch; E. Suárez-Morales.