Nick Holonyak Jr., inventor of the first practical light-emitting diode, which also marks the beginning in the use of III-V alloys in semiconductor devices, is the recipient of the Materials Research Society's highest honor, the 2004 Von Hippel Award, to be presented during its annual meeting this week in Boston. Holonyak is a professor of electrical and computer engineering at the University of Illinois and is a member of the Center for Advanced Study, University of Illinois, Urbana-Champaign. He is being honored "for his many contributions to research and development in the field of semiconductors, not least for the first development of semiconducting lasers in the useful visible portion of the optical spectrum," according to the society. Holonyak will speak on "From Transistor to Laser and Light-Emitting Diode," Wednesday at 6:30 p.m. at the Sheraton Boston Hotel grand ballroom, during an awards presentation ceremony and plenary session. Plenary speaker Mildred S. Dresselhaus, chairman of the governing board of the American Institute of Physics, will discuss advanced materials and using nanostructures to provide new materials, properties and opportunities for the independent control of materials structures and properties.    . . .    Susumu Okubo, a professor of physics at the University of Rochester, is the recipient of the American Physical Society's 2005 J. Sakurai Prize in Theoretical Particle Physics. Okubo is being honored for groundbreaking investigations into the patterns and decay rates of subatomic particles made of quarks and for his demonstration that CP violations, a phenomenon where a particle's "mirror image" does not behave exactly as a mirror image should, permit partial decay rate differences in the two "mirrored" particles. His research provided pivotal aspects of the quark model of matter, upon which the standard model of physics is built today. The awards will be presented at the society's annual meeting, to be held in April in Tampa, Fla.    . . .    Toshiba is collaborating in a study of the use of computed tomography (CT) for cardiac diagnostic imaging. Toshiba's Medical Systems Co. will conduct the multi-center clinical study to validate multislice CT use as the primary diagnostic tool for detecting cardiovascular diseases and defects, as compared to cardiac catheterization. Participants in the study, which began this month, include Johns Hopkins University School of Medicine, Baltimore; Beth Israel Deaconess Medical Center, Boston; Leiden University Medical Center, The Netherlands; Humbold University, Campus Charite Mitte, Germany; Incor Heart Institute of the School of Medicine Hospital, Sao Paulo University, Brazil; and Iwate Medical University, Japan.