The zebrafish as a model for human disease.

A paper jogging device is disclosed for stacking sheets of paper or the like into precise alignment directly onto a shipping skid. The device employs a jogger paddle that is flexibly attached to a rigid supporting means, and that is driven so as to be vibrated back and forth over its entire surface. The drive means comprises a plurality of thrust members which are actuated by a pair of synchronized rotating eccentrics employing a novel modified "scotch-yoke" coupling mechanism. The novel features of the jogging device are, (1) the entire surface of the paddle moves back and forth simultaneously, (2) the forward motion terminates at a predetermined fixed position with reference to the supporting means, (3) the acceleration and deceleration of the paddle is a simple harmonic motion requiring minimum driving power, and (4) the entire operation is very quiet.