In addition, these central groups were able to achieve some efficiencies and increase consistency in the implementation of the organization's security program by performing tasks centrally that might otherwise be performed by multiple individual business units.
The central groups were able to achieve efficiencies.
But a few Christian mosaics survive above the apse is the Virgin with the infant Jesus, with the Archangel Gabriel to the right (his companion Michael, to the left, has vanished save for a few feathers from his wings).