Provided is a functional UV paint including a flavonoid compound, a steroid compound, a polyphenol compound, or a mixture thereof, in which molecular weights of the compounds range from 250 to 1000. The mechanical pencil includes a grip barrel with a slide member to hold a piece of lead. The method provides unique modes of operational security over all phases of training course development, distribution and use which maintain privacy and protect individual interests of authoring clients, a server provider and student clients. In embodiments, combining the MOCO feature with the original image feature, the baseline object detector may be evolved to a stronger context aware detector. A user interface may be configured to display the visual representation of the sequence or segment and to allow a user to view andor modify properties associated with the sequence or segment. The device includes an annular disk which, when viewed in an axially direction, is arranged adjacent the ring gear on the side of the ring gear facing the differential cage and is coaxial with the ring gear.