A method includes receiving user-created content, as well as at least one of a service identifier and a content category ID of the user-created content. Treatment of the tissue with alkali, chelating agents, acids and salts removes non-collagenous components from the collagenous tissue matrix while controlling the amount of swelling and dissolution so that the resultant collagen matrix retains its structural organization, integrity and bioremodelable properties. The fixing elements reliably fix these screws in a prescribed position. To distinguish between the first and second types of synchronization signals, a time domain representation of the second type of synchronization signal includes a plurality of instances of the first type of synchronization signal. When the holding elements are released, the cables are retracted by the cable winding device, and the rotation of the cable winding device is transmitted to the flying body via the engaged catch elements and receivers.