Apparatus and methods for employing electrical properties of water to indicate the level of filtered water in a filtered water container. The compression member may include a fluid passage therethrough in fluid communication with the interior of the outer cylinder. The invention also provides kits for assessing cardiovascular conditions, substantially pure populations of cells, and methods of identifying compounds to treat life-threatening cardiovascular conditions. For example, such flexible pilot channel message delivery may more frequently deliver prioritized pilot channel messages, and less frequently broadcast low priority messages.