This revealed the four-stranded DNA arose most frequently during the so-called "s-phase" when a cell copies its DNA just prior to dividing.
BBC: 'Quadruple helix' DNA seen in human cells
2.
Nor would it be feasible to phase in the move to Malpensa: airlines that shift first would be at a disadvantage, and dividing the traffic of individual airlines between both Milan airports would double their costs.