Open access
Submitted: March 24th, 2011 Published: April 11th, 2012
DOI: 10.5772/30905
From the Edited Volume
Edited by Roberto Weigert
Submitted: March 24th, 2011 Published: April 11th, 2012
© 2012 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.