Scientific Reports 4: Article number: 4625; published online: 09 April 2014; updated: 30 June 2015

This Article contains an error in the Acknowledgements section:

“This work was partially funded by the Botín Foundation (JS, RVS), by the Spanish Secretaria de Estado de Investigación, Desarrollo e Innovación grants MTM2010-16425 (CS, RM) and BFU2012-30805 (SFE), by grant 2009-SGR-67 from the Catalan government (CS, RM), by grant NSF PHY05-51164 (JS, SFE) and by the Santa Fe Institute (RVS, SFE).”

should read:

“This work was partially funded by the Spanish grant FIS2012-39288 (RVS), by the Botín Foundation (JS, RVS), by the Spanish Secretaria de Estado de Investigación, Desarrollo e Innovación grants MTM2010-16425 (CS, RM) and BFU2012-30805 (SFE), by grant 2009-SGR-67 from the Catalan government (CS, RM), by grant NSF PHY05-51164 (JS, SFE) and by the Santa Fe Institute (RVS, SFE).”