Non-helical models of DNA structure the top of this article, or there could be an equal number of right-handed and left-handed twists, as in the Rodley structure below. The abbreviation "TN", to be used to refer to any DNA structure whose strands are topologically non-linked, has been proposed. The double-helix model of DNA structure was first published in the journal "Nature" by James D. Watson and Francis Crick in 1953 with further details in 1954.) Their work was based upon the crucial X-ray diffraction image of DNA - labeled as "Photo 51" - from Rosalind Franklin in 1952, followed by her more highly clarified DNA
DNA Tower The glass is held in place by a steel armature that is painted blue. The base support of the sculpture is surrounded and protected by a 5' tall circular cherry wood base that is 5'5" in diameter. "DNA Tower" was commissioned to commemorate both the 100th anniversary of the IU School of Medicine (founded 1903) and the 50th anniversary of the discovery of the structure of the DNA molecule (discovered 1953) by 1950 IU alumnus James D. Watson and his colleague Francis Crick. The glass pieces and painted steel armature were fabricated in Chihuly's Seattle studios. On September 23, 2003,