Funding for this research was provided by:
Wellcome Trust (WT093205 MA, WT104033AIA)
National Institute on Aging (ZO1 AG000957)
Received: 9 June 2017
Accepted: 25 October 2017
First Online: 2 November 2017
Ethics approval and consent to participate
: This study was approved by the UCLH institutional-research-board and informed consent was obtained from participants.
: Consent for publication was obtained from participants.
: The authors declare that they have no competing interests.
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