The two photocells are linked to the Tree: the Pre-Stage, and the Stage lights. When the car inches forward and blocks the first photocell, the Pre-Stage light comes on, indicating that the driver is close to the starting line. Most tracks have a rollout, or distance between the Pre-Stage and Stage beams of 6-8.
Batten disease is named after the British pediatrician Frederick Batten, who first described it in 1903. Also known as Spielmeyer-Vogt-SjÃ¶gren-Batten disease, it is the most common form of a group of disorders called neuronal ceroid lipofuscinosis (or NCLs).
The syndrome is named for pediatric geneticist Harry Dietz, director of the William S. Smilow Center for Marfan Syndrome Research at Johns Hopkins University and his colleague, Bart Loeys, who characterized the genetic and physical markers of the syndrome together with Dr. Dietz.