A behavior of a walker is detected according to combination of detection of the walking behavior on a level and an altitude variation of the walker to more accurately detect the behavior of the walker. The method can include imaging, such as ultrasound imaging, a lung of a live animal, such as a ruminant animal or bovine animal. The at least one negative plate includes a current collector, consisting essentially of a layer of carbon foam disposed on a substrate, and a chemically active material disposed on the current collector. A first conveying member is provided in each process cartridge.