The present invention relates to methods and compositions for identifying and detecting lethal cell useful for monitoring disease status and therapy response in various types of cancer patients regardless of the etiological origin of the cancer and uses thereof. In an embodiment, a client is operable to query a first layer of the protocol stack used to provide a link that carries packets for said client. In the battery test mode, the battery chargertester allows current to flow to the utility power source so as to provide a consistently repeatable power draw from the battery reducing the error in detection of a weakened battery. The socket assembly comprises a potting-filled conductive sleeve having a continuously shaped, smooth terminal end. Upon wing extension and retraction, controls for road transport and flight controls alternately emerge or are stowed inoperably, as needed. The plug or the socket is symmetrical with respect to the latch on the catch, so that the buckle may be clasped and secured without regard for the orientation of the socket and the plug.