Funding for this research was provided by:
Fundação para a Ciência e a Tecnologia (IF/00376/2015, IF/01396/2013)
Text and Data Mining valid from 2019-03-14
Received: 8 January 2019
Accepted: 15 February 2019
First Online: 14 March 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.