Setting up the Keynote by David Yokum over Skype.
Surgeons‘ Hall could connect the presentaraion laptop with David in Washington DC only over wifi, and the limited onsite wifi bandwith required minimal usage by other connections from meeting attendees - hence the need for radio silence.
David Yokum [who led the Obama Administration’s Social & Behavioral Sciences Team in Washington DC] at the last hour was unable to travel to Edinburgh; I organised with him live delivery of his talk over Skype. See the photo of David’s Keynote.