Following the 2005 drought, scientists were able to study the impact on trees and work out the relationship between the rainfall loss and the release of carbon.

BBC: Amazon drought 'severe' in 2010, raising warming fears

The committe made the decision on the grounds that the painting was of outstanding significance for the study of the relationship between British and American painting in the 19th Century.

BBC: Rare Cropsey landscape in export bar

On a more scholarly level, Mr. MacKerron is collecting the information to study the relationship between moods, communities and the places people spend time.

WSJ: The Really Smart Phone