An engine is provided comprising a cylinder, a piston, a connecting rod, and a crank. The circuit senses a voltage drop of the internal node and mirrors its current to the internal node to hold the internal node voltage when the voltage starts to drop low enough to turn off the output transistor. In an aspect, the invention relates to compositions and methods for inhibiting vascular apoptosis. Reliability of addition of the first still image and the motion-compensated second still image is determined pixel by pixel and a weighting factor is set corresponding thereto.