Device for locking the articulated joint in the longitudinal direction between the plate of a dust mop and the handle, which permits deactivation and subsequent reactivation of the locking of the articulated joint between the handle and the plate in a longitudinal direction, carried out by the user with his feet instead of his hands. The lock includes a receiver arranged to receive a remote input signal including at least one authorization code. The present invention also provides host cells having a mutation or deletion of part or all of the gene encoding the metalloprotease. A plurality of fasteners used to join the main reflector to the sub-brackets and the sub-brackets to the main reflector swivel when loose and become rigid when fastened. A predetermined number of the signals are accumulated to form a series of compound samples, and the compound samples are filtered to detect components indicating the lighting flicker. The semiconductor device includes a layer of semiconductor material having a source and a drain, and a dual work function gate disposed on the layer of semiconductor material to define a channel interposed between the source and the drain.