Science  28 Mar 2003:
Vol. 299, Issue 5615, pp. 1957

You are currently viewing the .

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

  1. RESOURCE: Deep Impact

    Find out the most influential papers and authors in some of today's hot and fast-growing disciplines at this site from the Institute for Scientific Information (ISI) in Philadelphia. ISI is best known for subscription- based databases that track citations in a range of fields. Every month, however, the free Essential Science Indicators Special Topics site analyzes publications on a particular hot topic—from photonics to obesity—ranking papers, authors, institutions, countries, and journals based on the number of citations over the previous 10-year period. For instance, the top study on West Nile virus is a 1999 Science paper that identified the origin of the bug. Along with these long-term trends, the site identifies new papers that are tallying lots of citations and pegs “emerging research fronts,” topics within a field that are booming. ISI also interviews authors about their oft-cited study, current work, and career. Although some of these interviews are terse and technical, others shine—such as the discussion with entomologist Bruce Tabashnik of the University of Arizona, Tucson, about pest resistance to natural insecticides.

  2. DATABASE: The Scoop on Toxins

    This site from the Environmental Protection Agency (EPA) is an essential resource for anyone looking for authoritative safety information on hazardous chemicals. The Integrated Risk Information System (IRIS) summarizes the human health effects of hundreds of potential toxins and carcinogens, from molecules such as ethylene glycol to pesticides to complex mixtures such as diesel exhaust. IRIS's target audience is risk assessors, who combine the toxicity information with their own data on exposures to determine, say, how clean a waste site needs to be, or how much chemical can be safely released into a river. To produce each account, EPA scientists evaluate and synthesize reams of studies on the toxicity and potential carcinogenicity of a substance. The information includes safe exposure levels for people, known as a reference dose, and an uncertainty factor—a safety margin that reflects complexities such as extrapolating from animal studies to humans and variability among individuals. The site also offers a glossary and in-depth reports on more than 30 recent additions to the database.

  3. IMAGES: Tricks of the Light

    To learn how the brain works, neurobiologists such as Dale Purves of Duke University Medical Center try to dupe it. These 16 animations, from Purves's lab use illusions to explore how factors such as orientation, lighting, contrast, and background shape our visual perception. Above, for example, the central squares on the front and top face of the cube are the same shade of brown, but they can appear yellow, depending on how much light seems to be hitting the face. Background articles provide in-depth explanations for each visual trick.

    OK, so we're suckers for subtle illusions, but surely we'd notice if a gorilla shambled into the room. Maybe not, as these short movies from the Visual Cognition Lab at the University of Illinois, Urbana-Champaign, demonstrate. (The flicks are about halfway down the page.) Concentrating on one demanding task, such as tallying the number of passes a basketball team tosses, can make you oblivious to even bizarre events within your field of vision. The phenomenon, called inattentional blindness, might explain why drivers blathering on cell phones are more likely to get in accidents.

  4. EXHIBITS: Machine Learning

    An engineer designing a walking robot and a morphologist trying to understand the operation of a bat's wing need to know kinematics, the geometry of motion. The Digital Library of Kinematics project at Cornell is creating virtual versions of the famous teaching machines designed by Franz Reuleaux, a 19th century German engineering professor. The online library will not be complete until 2004, but its site already offers an interesting sample of future content. For instance, visitors can use photos, videos, and other media to analyze the Peaucellier mechanism, which translates the circular motion of a crank into the up-and-down motion of a piston. Interactive models let you run the machine at different speeds, trace the motion of the components, and scrutinize particular linkages up close.