scientific american - 1996 06 - the space station

... the impact of urban agriculture con- tinues to broaden, the notion of the gar- den city the turn-of -the- century dream of urban centers lined with trees and or- namental plants —may take on a new ... data from the probe’s 57-min- ute descent did not chal- lenge the prevailing hy- pothesis of the evolution of the solar system and its largest planet, according to Richard Young...

Ngày tải lên: 12/05/2014, 15:08

... that they were the few Cretaceous survivors. The foundation of this theory began to shake in 1981, when fossils of Òop- posite birdsÓ were unearthed in China and, then, all over the Northern Hemi- sphere. ... and lead to the hy- poactivity seen there during clinical de- pression. If he is right, the theory would explain the gender gap, at least in part. Others at the NIMH have m...

Ngày tải lên: 12/05/2014, 15:01

... OGDEN Copyright 1995 Scientific American, Inc. SCIENTIFIC AMERICAN January 1996 31 easily destroyed. Moreover, some theo- rists raised certain technical objec- tions, namely, that the release of a pho- ton ... transform their experiment into the quantum eraser, the researchers tagged one of the photons of the pair (speciÞcally, the one created by the la- serÕs direct pa...

Ngày tải lên: 12/05/2014, 15:04

... Aeronautics and Space Adminis- tration unveiled the X-36 the first high-performance jet with no tail at all. Remotely controlled and powered by a cruise-mis- sile engine, the 5.4-meter-long, 600-kilogram scale ... Among the most com- mon mines in this group are the Italian scatterable mines TS-50 and SB-33 and the hand-laid VS-50 and VAR-40, the U.S made M14, and the Chinese T...

Ngày tải lên: 12/05/2014, 15:08

... constantly up- dated records and forecasts. The SEC is now working in collabo- ration with the National Weather Ser- vice’s “weather wire” to warn via radio of severe space weather, much as the weather ... users of conven- tional cellular phones. SA MICHAEL GOODMAN Copyright 1996 Scientific American, Inc. The Stellar Dynamo 46 Scientific American August 1996 Copyright 19...

Ngày tải lên: 12/05/2014, 15:14

... protected under the executive order’s “state-of -the- art” tech- nology exemption to the bulk declassi - cation rule. But that introduces another concern. The issue is, what does state- of -the- art technology ... risk factors may affect the expres- sion of the disorder,” the group con- cludes in the Journal of the American Medical Association. The lead author of the s...

Ngày tải lên: 12/05/2014, 15:16

... of bird-watchers, and they love the birds. And after they watch them, they go home and put up their bug zappers. These birds, even the seed eaters, are feeding heavily on insects when they’re ... traveling the interstate since the wee hours of the morn- ing and what they might say when they arrive at the Capitol and meet with their elected rep- resentatives. Most of his audi- ence...

Ngày tải lên: 12/05/2014, 15:26

... not seem to be the stuff of wild urban legend anymore. Neverthe- less, the rich mythology that has sprung up around the 840-acre island makes it a must-see stop on the con- spiracy theorist’s world ... pain —drugs in the same class as ibuprofen and aspirin. The McGeers, hus- band-and-wife neuroscientists at the Uni- versity of British Columbia, are betting on nonsteroidal anti-i...

Ngày tải lên: 12/05/2014, 16:03

... archaeologists tell layers apart by playing a game of which-stars- are-not-like -the- others. The sun and most other stars swirl around the galactic center within a thin circular disk. Nearly a ... grow the same way that planets do: from the agglomeration of smaller units. The layering of the Milky Way bears that out. On the other hand, cold-dark-matter theories have trouble exp...

Ngày tải lên: 12/05/2014, 16:08

... the wom- en in the rural areas have that same cy- cle, and they teach the same values to their children. They teach their sons to order; they teach their daughters that they must serve even their ... chromosome. To their pleasure, they realized that previous genetic studies had im- plicated roughly the same part of the chro- mosome in SCID. They decided to test the hypothesis that...

Ngày tải lên: 12/05/2014, 14:49