TUCSON, Arizona, March 14 -- The University of Arizona posted the following news release: * * * Bear Down 100: Reading time in wood * Inside every tree trunk is a record of every year it lived. For nearly a century, the University of Arizona has been the world's leading institution for reading that record. Trees grow one ring per year, and the width of each ring reflects the conditions of that year. A wide ring signals a wet, favorable season. A narrow one points to drought or stress. Beca more PR