The present invention envisages a GSM mobile telephone in which a line of icons is displayed on a display. In operation, a first DC component is extracted from the measured output signals obtained during the first 180 degrees of rotation of the optical element and a second DC component is extracted from the output signals obtained during the second 180 degrees of rotation of the optical element. The blocks or a list of references to the blocks are stored in a non-volatile solid-state memory, such as a flash-based memory, that is separate from the main drive subsystem and has a much shorter power-up and read-access time than the main drive subsystem. The collar processor activates the probes upon receiving a first level signal when the animal is within a first predetermined distance from a remote. A source of vacuum or suction may be used to increase the amount of fluid withdrawn from the lung tissue.