This roller rack was illuminated by twenty-two Phillips 32-watt coolwhite T8 fluorescent
lights set to a 16 h:8 h light:dark photoperiod. Using a UV AB meter (UV513AB, General Tools, New York, NY), ultraviolet light output from these bulbs was approximately 113 mW cm22.
The entire apparatus was located in a walk-in environmental chamber that was set to a constant 18uC.