A method of treating acne in a human in need thereof comprising administering systemically to said human a tetracycline compound in an amount that is effective to treat acne but has substantially no antibiotic activity, without administering a bisphosphonate compound. In order to evaluate the duration of a mechanical impulse acting on the battery, the activation device can be freed by a timing member having an inertia body which is axially and rotatably displaceable and against which a compression spring is operative. In one particular application, the interface is between the digital data network and an optical disc drive that outputs an analog signal. Further, metadata regarding the digital asset can be captured at any time to provide an audit trail for the digital asset from development all the way through deployment. The amount of opening movement of the gate members is selectively adjustable without the need of a wrench or the like.