Various system embodiments comprise a neural stimulation delivery system adapted to deliver a neural stimulation signal for use in delivering a neural stimulation therapy, a side effect detector, and a controller. The distinguishing agent may be used for determining a remaining thickness of the thermally insulating layer. The implantable atrial defibrillator is capable of detecting AF, automatically sending warning signal and diagnostic data to an external portable device after detection of AF, receiving commands from the external portable device, and cardioverting AF. The lease rates are prices per unit of airtime to be paid by an operator associated with one or more of the network devices. Manual orientation of antenna for linear polarized satellites yields lower weight and power usage. More particularly, the invention pertains to compositions with enhanced high temperature stability comprising a polyalkylene glycol based polymer and an anionic surfactant.