There was an error in the funding statement. The correct funding statement is: The research was supported by the National Science Foundation (Grant no. 0347960 to LRG). MGS was funded in part by the European Community's Seventh Framework Programme (FP7/2007-2013; http://cordis.europa.eu/fp7) [^] under grant agreement n° 235897 and the Spanish Ministry of Science and Innovation (CGL2009-07301-BOS). The authors are grateful for a grant provided to CHC from Consejo Nacional de Ciencia y Tecnología (Scholarship No. 95802). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Footnotes
Competing Interests: No competing interests declared.