The operating and other procedures of an optical disk application system of the type for which a network is used are simplified. As portions of a streaming media file are downloaded for playback, the size of the portion is compared with an expected size determined prior to initiating playback of streaming AV data. A method for bromination of ortho alkyl substituents of aromatic compounds is also described. A measuring device measures analyte concentration of a bodily fluid sample received by a test element. The transmission shaft can be driven by a power source.