1. Department of Mechanical Engineering and Materials Science; Duke University; Durham North Carolina 27708 U.S.A.
2. Department of Radiology; Duke University Medical Center; Durham North Carolina 27710 U.S.A.
3. Anderson Cabot Center for Marine Life; New England Aquarium; Boston Massachusetts 02110 U.S.A.
4. Department of Biology; Boston University; 5 Cummington Mall, Boston Massachusetts 02215 U.S.A.
5. Nicholas School of the Environment and Pratt School of Engineering; Duke University Marine Laboratory; Beaufort North Carolina 28516 U.S.A