Article History
Received: 10 August 2017
Accepted: 12 August 2017
First Online: 2 September 2017
Compliance with ethical standards
:
: Valerio Ferrara declares that he has no conflict of interest. Ciriaco Buonomenna declares that he has no conflict of interest. Giovanni Mauri declares that he has no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.