Funding for this research was provided by:
Konung Gustaf V:s och Drottning Victorias Frimurarestiftelse
Received: 21 September 2018
Accepted: 19 November 2018
First Online: 7 December 2018
Ethics approval and consent to participate
: Informed consent was obtained from all volunteers after verbal and written information and the study was approved by the local Ethics Committee at Umeå University, Sweden, and performed according to the declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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