The cell-like envelopes in which life on Earth arose and evolved may literally have dropped from the sky. (p. 68)

Spraying “good” bacteria into the nose reduced the incidence of ear infections in children especially prone to such infections. (p. 68)

A carnivorous plant called a bladderwort may not be a fierce predator at all but a misunderstood mutualist. (p. 69)

Experienced classical-music conductors learn to pinpoint the sources of sounds originating from the side as well from in front of them, an essential skill for fine-tuning the performance of each musician in an orchestra. (p. 69)

Researchers say they can now use earthquake-detecting seismometers to detect and possibly track all but the weakest tornadoes. (p. 70)

One of the largest glaciers in Antarctica is growing thinner and retreating inland, spurring concerns that changes occurring along the coastline may be causing the ice stream to drain more material from the interior of the continent and send it out to sea, thus aggravating rising sea levels. (p. 70)

Science Service and Intel announced the 40 finalists of the 2001 Intel Science Talent Search this week. (p. 71)

The genome of a toxic Escherichia coli strain shows that the pathogen had picked up chunks of DNA from unrelated, ineffective bacteria, acquiring unpleasant traits that can send people to the hospital. (p. 71)

While researchers tease out the mechanisms behind the ability of inert pills and sham procedures to trigger health benefits, the ethics of using such placebos in medical research trials is coming under increasing scrutiny. (p. 74)

Some chemists are sharing their research results more quickly and broadly as they begin to venture into electronic archives, where they can immediately post new, unreviewed papers, as physicists have done for a decade; others think such archives could mean the end of reliable chemistry research. (p. 76)

Parents and siblings of severely depressed teenagers suffer from a disproportionately high rate of severe depression, strengthening the theory that a common form of this disorder afflicts young and old alike. (p. 72)

The human visual system flexibly uses available visual information for guidance as people walk toward targets, according to tests conducted in virtual environments that violate the laws of optics. (p. 72)

Researchers have identified a protein integral to making blood clot, a finding they hope will lead to better drugs for preventing clots in people at risk of heart attack or stroke. (p. 72)

In the past 10 years, angioplasty and other procedures to unblock clogged arteries have steadily improved, probably due to increasing use of wire-mesh tubes called stents to help patients’ arteries stay open. (p. 72)

Some plastics can accumulate toxic pollutants from water, increasing the risk that they might poison wildlife mistaking these plastics for food. (p. 79)

Tainted ingredients of livestock feed can contribute to worrisome residues of organochlorines, such as PCBs, ending up in meat. (p. 79)

State, federal, and Indian agencies have joined forces to develop policies aimed at stemming a huge, seasonal zone in the Gulf of Mexico where oxygen levels are too low to sustain most aquatic life. (p. 79)

Nearly 2 percent of U.S. electricity each year goes to power office equipment that had ostensibly been turned off. (p. 79)