scientific american - 2004 05 - the time before time

... disrupting the signals between neurons. COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. 28 SCIENTIFIC AMERICAN MAY 2004 I n the 18 years since they were dis- covered, high-temperature supercon- ductors ... what remains of the mess left by the Exxon Valdez. The oil compo- nents are poisoning the otters. COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. www.sciam.com SCIENTIFIC...

Ngày tải lên: 12/05/2014, 16:20

... 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 Type 72. Typically, these weapons ... 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-...

Ngày tải lên: 12/05/2014, 15:08

... from the bubble-enclosed flow- er. The filters in the kit allow for sepa- rate samples to be taken at different times throughout the day. For example, the peak scent for the orchid purchased from the ... offered to them, some home owners will balk at the idea of selling their excess electricity at a dis- count to the local utility, which then re- sells the power for several...

Ngày tải lên: 12/05/2014, 15:23

... that the mi- grating bats may not be using their echolocation when the collisions occur. Others spec- ulate that the wind turbines may be emitting high-pitched sounds that draw the bats to the ... two other groups the car- charodontosaurs and the spinosaurs—man- aged to evolve similarly supersize propor- tions.) In recent years, a few prime-mover hy- potheses have emerged, attrib...

Ngày tải lên: 12/05/2014, 16:19

... than the 1 4- out-of-15 match. To the scientistsÕ de- light, there was a large difference, al- though commercial implications inhibit candor when they are posed the ques- tion, ÒHow big is the ... small and medi- um-size businesses. Until the early 1990s, the World Bank ignored the economic signiÞcance of these events or dismissed them as irrel- evant. At the same time, ho...

Ngày tải lên: 12/05/2014, 15:01

... Biológica of Doñana-CSIC. At night, the animals leave the safety of the scrubs to hunt on the open lands and find themselves at the mercy of hounds unleashed by the poach- ers during their nocturnal ... badgers belonged to the five territories in Coto del Rey; the others resided within the core of the park, Reserve Biológica. Of the tagged bad- gers, the team recorded 13...

Ngày tải lên: 12/05/2014, 16:08

... subjects at the time of the serendipitous observation. Of the 30 individuals who received the EP-MRSI scans, 23 reported immediate mood im- provement, the team says in the January issue of the American ... the turn of the 20th century.” The stone “contains more lithium than any other stone on the planet” and “emits a signa- ture one-of-a-kind healing energy.” How doe...

Ngày tải lên: 12/05/2014, 16:19

... PAP 6 T cells then attack PAP- containing cancer cell 40 SCIENTIFIC AMERICAN JULY 2004 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. quires isolating the patient’s white blood cells and then separating ... Bayesian theorem: P before × D P after = P before × D + 100% – P before The probability of God’s existence after the evidence is con- sidered is a function of the pro...

Ngày tải lên: 12/05/2014, 16:20

... CELSIUS) 4,9 005, 150 4,650 4,400 12-BILLION-YEAR- OLD AGE TRACK 15-BILLION-YEAR- OLD AGE TRACK NGC 288 NGC 362 Copyright 1992 Scientific American, Inc. means that within the halo the only re- maining main-sequence ... declines as the reefs get farther away from two centersÑone in the Indo-Pa- ciÞc and the other in the Caribbean. The outlines of a map marking plum- meting di...

Ngày tải lên: 12/05/2014, 14:48

... betatron have the special advantage of produc- ing their greatest eÝect about 1 1 Ú 2 inch- es below the surface of the body. With X-ray therapy as used up to the present time, the eÝect is greatest on the ... the sur- face, and decreases with depth. Direct use of the high-speed electrons from the betatron may be even more valu- able than the use of the X-rays. Most of...

Ngày tải lên: 12/05/2014, 14:49