"Dove Courtesy of Chlorophyll Fluorescence Analysis"

This year's winning holiday card was submitted by Shaun Bailey and Blaise Hamel from the Department of Plant Biology.

The dove design on the leaf was made using chlorophyll fluorescence analysis, a technique which allows the determination of the efficiency of photosynthesis.

Photosynthetic efficiency is reduced after exposure to intense light. In order to produce the image, Carnegie scientists placed a mask in the shape of a dove on a leaf, thereby serving to block light from reaching the portion of the leaf covered by the mask.

After the mask was removed, the scientists made a chlorophyll fluorescence image of the leaf. The dove glows with a different color from the remainder of the leaf because of the difference in photosynthetic efficiency.

Congratulations to the winning submission, and many thanks go out to everyone who participated.