Osteoporosis is a major socioeconomic problem in western societies. Since excessive use of therapeutic agents often has adverse effects on patients, noninvasive diagnostic tools to determine their need are essential for effective management of the disease. The new technique proposed here examines how bones respond to vibrations of various frequencies, with healthy bone responding differently to weak bone.

Journal article: http://link.aps.org/abstract/PRE/v66/e061904

2) Deconstructing birdsong
R. Laje, G. B. Mindlin
Physical Review Letters (Print issue: December 31, 2002)

The complex chirping and warbling of a bird's song may be the product of a relatively simple circuit in its brain. Researchers modeled a part of the bird brain that can generate diverse song elements. They found that a single arrangement of cells showed behavior complex enough to produce much of the variety in a sparrow's tune.

Physical Review Focus: http://focus.aps.org/story/v11/st1
Journal article: http://link.aps.org/abstract/PRL/v89/e288102

3) Getting more from MRI
V. G. Kiselev, D. S. Novikov
Physical Review Letters (Print issue: December 30, 2002)

A new analysis technique could get micron-scale data out of MRI scans of blood, brain cells, and even buried minerals--without having to re-engineer anything in the machines themselves. Standard MRI imagers today can resolve down to about half a millimeter on a live human, but now a team describes a way of analyzing MRI data to squeeze out information on the average shapes and sizes of particles only a few microns across.

Physical R
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Contact: David Harris
harris@aps.org
301-209-3238
American Physical Society
9-Jan-2003