A waistband for an absorbent article having a waistband with differential extensibility andor contraction along the circumference of the waist opening. That is, the rounded surface or ball is urged toward the bottom of the trochlear groove. A master power source and a slave power source supply power to the load. According to an alternative embodiment of the invention, a portable electronic device is used to query and collect data from the subject. A foamed article produced from the particles has high strength and a good appearance.