A parallel computer operates to reduce data held by a plurality of nodes. According to one embodiment, an apparatus includes classifier logic to categorize frames that represent an image as either reference frames or non-reference frames, where the categorization is based, at least in part, on motion vectors between the frames. Once induced to differentiate into neuronal cells, the cells can be used for cell therapy, gene therapy, or both, for treatment of diseases, disorders, or conditions of the central nervous system. In the event the device is available for use by user mode USB drivers, but has been opened for write by one user mode USB driver, all other user mode USB drivers will be prevented from claiming the device. The switching mechanism is arranged in the fixation unit and is in transmission with the connection part.