Two digital data sets are combined by equating a first subset of samples to neighboring samples from a second subset which is interleaved with the first subset of samples where the equated samples of the two digital data sets do not correspond in time, and by subsequently adding corresponding samples from both digital data sets. The discharge device has a head including a cover which is extending beyond upper end of the passage such that the cover is covering the upper end of the passage, a liquid discharge port which is protruding from the cover toward the substrate in the horizontal position, and a curved portion which is formed between the port and cover such that the curved portion has a surface bending downward. Such inhibition may be accomplished by ligands or antibodies that bind to BMP-2 or BMP-2 receptors.