Funding for this research was provided by:
University of Lübeck, Germany (Junior Research Grant)
Received: 13 November 2019
Accepted: 11 February 2020
First Online: 21 February 2020
Ethics approval and consent to participate
: Ethical approval was obtained from the local ethics committee at the University of Luebeck (17-354A9). The need for consent was waived by the ethics committee.
: Not applicable.
: The authors declare that they have no competing interests.