Thermo Electron Corp. announced today that Jim Manzi, a member of its board of directors, has been named chairman of the board. Manzi, the former chairman, president and CEO of Lotus Development Corp., will succeed Richard F. Syron, who has resigned as Thermo Electron's chairman of the board, executive chairman and a member of the board to become chairman and CEO of Freddie Mac. Also, Barry S. Howe, vice president of Thermo Electron and president of it Measurement and Control sector, has announced he will leave the company this spring to pursue other interests. In the meantime, he will assume the new position of vice president, new business development. Marijn E. Dekkers, CEO, will now oversee the three divisions of the Measurement and Control unit.   . . .   BAE Systems announced it has chosen Wind River's VxWorks real-time operating system as the foundation for its SCC500 series of infrared camera cores. The camera cores are designed to convert infrared energy (heat) emitted from objects into a viewable image, even when they are obscured, for example by darkness or smoke. Applications include fire fighting, border surveillance and military night-vision enhancement.   . . .    Hologic Inc., a Bedford, Mass. provider of medical imaging equipment, demonstrated its full-field digital breast tomosynthesis research system at the 2003 annual meeting of the Radiological Society of North America last week . Breast tomosynthesis allows a series of images in slices of 1 mm or less to be acquired and reconstructed for 3-D viewing; the company said it has the potential to reduce or eliminate overlapping tissue, which can obscure a lesion. The system is available as a research unit for users of Hologic's Lorad Selenia full field digital mammography system.