In a positively chargeable toner, calcium carbonate fine particles having a certain average primary particle diameter are attached to the surface of toner base particles. The thickness tA of the oxide film 301 is determined on the basis of the reference data. The content may be associated with a particular topic andor forum. The vibrating and fixed electrode plate are disposed on a surface side of the substrate such that an opening on the surface side of the through-hole is covered. Blockers of KCNQ channels are known to enchance cognition in laboratory animals. The data sampling clock signal is used to sample a data signal into sampled data representing a first zone, a second zone, and a third zone of the data signal.