A method is described by which digital data can be sent between mobile phones concurrent with speech during a same phone call. The polymer film has a thermal conductivity greater than 3 Wm\xb7K and a thickness that does not exceed 10 micrometers. The sides may be extended to intersect without the necessity for a flat bottom surface as is typical for prior art weld joints. Where an address line shorts, the associated address line resistor protects the head driver IC from the short, allowing it to control the voltage potential of that address line in any printhead that has not failed. The grooves are uniquely designed to cause the backing plate to impart a compressive load into the backside of the frontal member preventing it from prematurely fracturing in tension at the onset of the projectile penetration. In another aspect, the invention provides for specific administration of the phosphodiesterase inhibitor prior to the luteal phase of the host’s ovulatory cycle.