The invention relates to regulating access by users to a scarce resource, wherein the resource is capable of handling multiple concurrent accesses. A photoelectric conversion element, a diode-connected first transistor, and a second transistor are included. When the images of the received program should be filtered, the images of the input video signals are scaled beyond recognition and displayed on the screen of the display device. These higher levels are achieved through increasing daily dosage amounts gradually in response to patient tolerance and until beneficial results are seen. Further, a use of the present compounds in preventing and treating depressive-type mental diseases is disclosed. A switch core 271 passes frames to be transmitted to the line termination unit that operates as the active system.