© Copyright A.W. Wu et al., 2013. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (<a href="http://creativecommons.org/licenses/by-nc/3.0/">http://creativecommons.org/licenses/by-nc/3.0/</a>) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Except where otherwise noted, this item's license is described as © Copyright A.W. Wu et al., 2013. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (<a href="http://creativecommons.org/licenses/by-nc/3.0/">http://creativecommons.org/licenses/by-nc/3.0/</a>) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.