A protein produced by nerve cells is essential for the manufacture of myelin, the fatty sheath surrounding nerve fibers. (p. 163)

After a month of long hours of challenging work, fatigued physicians show impairments in driving and other tasks requiring constant attention and quick reactions. (p. 163)

After a 14-month climb up a Martian hill, NASA's rover Spirit took a panoramic image of the view from the top. (p. 164)

Positive thinking exerts a calming effect on pain-related brain areas, yielding a substantial reduction in the actual perception of pain, a brain-scan investigation suggests. (p. 164)

Scientists have proposed a way to control the distribution of contaminants in silicon, potentially opening up the use of cheaper starting materials for making solar cells. (p. 165)

Y-shaped nanotubes might become a common component in ultrasmall electronic circuitry. (p. 165)

A male fish produces a burst of hormones as he fights off an intruder, but this surge isn't triggered simply by fighting. (p. 166)

Data from the Deep Impact mission reveal that the bullet that slammed into Comet Tempel 1 on July 4 excavated material that likely hadn't seen the light of day since the birth of the solar system 4.5 billion years ago. (p. 168)

Scientists are tracking the spread of a threatening influenza virus in birds and exploring strategies that could be used to halt a potential outbreak in people before it explodes into a global epidemic. (p. 171)

A protein is pivotal in bringing on the psychotic attacks that beset people with porphyria, a rare inherited disease. (p. 173)

A battery that's activated by body fluids such as saliva or urine may one day power devices ranging from disposable home health-care testing kits to emergency radio transmitters that turn on with a lick. (p. 173)

Strong seismic activity on Venus could cause brief but detectable temperature increases high in that planet's atmosphere. (p. 174)

A drug called valproic acid, used in combination with other medications, can ferret out HIV that is lying dormant in cells. (p. 174)

A new federal service, offered jointly by the U.S. Environmental Protection Agency and the National Weather Service, will notify individuals, via e-mail, when the sun's cancer-causing ultraviolet radiation is forecast to be unusually high. (p. 174)

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We at Science News express our strong concern and extend our deepest sympathy to those who are suffering through the ongoing ordeal caused by Hurricane Katrina. (p. 163)