Lurking more than 13 billion kilometers from Earth in the coldest, remotest part of the solar system, a newly discovered body is the most distant object ever found to orbit the sun and the largest denizen of the solar system discovered since Pluto. (p. 179)

An unusual strand of RNA guides stem cells to transform into neurons. (p. 179)

Scientists have built a tiny rotor out of a synthesized molecule that rotates in the presence of an electric field. (p. 180)

Brain tumor cells have a dearth of an obscure protein called ING4, whose sister compounds have shown anticancer effects. (p. 180)

The largest sample of ancient mitochondrial DNA extracted from Stone Age fossils to date indicates that Neandertals made, at most, a small genetic contribution to our direct prehistoric ancestors. (p. 181)

By creating an extremely thin layer of an unusually electron-hungry form of iron, chemists have made a prototype rechargeable battery electrode that may lead to improved metal hydride batteries. (p. 181)

Herbert Mason Hedberg, the 2004 winner of the Intel Science Talent Search, and 39 other students have received recognition and scholarships for their innovations in science, mathematics, and engineering. (p. 182)

Researchers are racing to identify tumor-forming stem cells in skin, lung, pancreatic, and many other cancers. (p. 184)

Data on extensive giveaways of daughters by their mothers in northern Taiwan a century ago may challenge influential theories of innate maternal sentiments. (p. 186)

Engineers are readying a NASA spacecraft for a May 11 launch to Mercury, one of the least-explored planets in the solar system. (p. 188)

Hornbills can tell the difference between two kinds of alarm calls given by monkeys. (p. 188)

An experimental drug that slows blood flow in the brain knocks out migraine headaches in some people. (p. 188)

Data from two 18th- and 19th-century farming communities supports the theory that child care assistance from grandmothers has contributed to the evolution of extended human longevity. (p. 188)

Researchers have demonstrated a new way to simplify some intricate patterns whose extreme complexity has convinced theoretical physicist Stephen Wolfram that traditional science can't explain many important natural phenomena. (p. 189)

Heart patients can lessen their risk of a heart attack and increase their odds of survival by aggressively reducing harmful low-density lipoprotein (LDL) cholesterol in their blood. (p. 189)

Streams of ants manage to avoid traffic gridlock by a bit of strategic pushing and shoving. (p. 190)

Piercing the upper-ear cartilage under nonsterile conditions can leave a person vulnerable to a Pseudomonas aeruginosa infection, as happened in Oregon in 2000. (p. 190)

People exhibit a surprising amount of brain activity in common while viewing a dramatic movie, a brain-imaging study finds. (p. 190)

(p. 191)