A light source driving apparatus for sequentially driving a plurality or light sources is provided. A delivery device including controllably dissolvable silica-xerogel into which structure a biologically active agent is incorporated. Solar battery cells are sealed in the sealant. Upon detecting that the primary P2P communication channel has failed or has degraded below a specified threshold, one of the secondary P2P communication channels can be automatically promoted to a primary P2P communication channel. After the object is slid onto the base, the retainer may be raised to a transport position in which the retainer at least partially encircles the object to hold the retainer on the base.