The following license files are associated with this item:

© 2018 Ana María Mesa Vanegas 
et  al
.  This is an open access article 
distributed under the terms o
f the creative commons attribution License,
which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.
Except where otherwise noted, this item's license is described as © 2018 Ana María Mesa Vanegas et al . This is an open access article distributed under the terms o f the creative commons attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.