3:36 AM
Beena
2:36 PM
Beena
THE cosmos is quiet. Eerily quiet. After decades of straining our radio ears for a whisper of civilisations beyond Earth, we have heard nothing. No reassuring message of universal peace. No helpful recipe for building faster-than-light spacecraft or for averting global catastrophes. Not even a stray interstellar advertisement.
Perhaps there's nobody out there after all. Or perhaps it's just early days in the search for extraterrestrial intelligence (SETI), and we're listening to the wrong star systems or at the wrong wavelengths.
There is another possibility, says Douglas Vakoch, head of the Interstellar Message Composition programme at the SETI Institute in Mountain View, California, which ponders the question of how we should communicate with aliens. "Maybe everyone's listening but no one is transmitting. Maybe it takes an audacious young civilisation like ours to do that."
So should we start sending messages into the void? And if so, how can we make ourselves understood to beings we know nothing about?
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2:20 PM
Beena
An Earth-based telescope spotted the 10-metre space rock hurtling our way just three days before a near miss on 13 January, when it flew by at just one-third of the distance to the moon (see Object headed towards Earth an asteroid, not junk). The asteroid is never expected to hit Earth and would burn up before hitting the ground in any case. But its unusual orbit (see diagram) seems ingeniously designed to evade our surveys. It is likely that a handful of objects large enough to cause harm are hiding under similar circumstances.
Large asteroids are relatively easy to spot because they reflect the most sunlight. But smaller asteroids - which can still damage Earth if they span at least 30 to 50 metres - are usually too dim for telescopes to detect except during brief close approaches to Earth. For a typical near-Earth asteroid, these occurrences are a few years or decades apart.
However, last week's unexpected visitor, called 2010 AL30, kept far enough from Earth to be invisible for more than a century. The prolonged avoidance occurred because the period of its solar orbit was 366 days - very close to Earth's year (though the close pass shifted the space rock into a 390-day orbit). Like a slightly slower race car that is periodically lapped by its competitor on a circular track, it stays far from Earth for long stretches.
"2010 AL30 may become a sort of 'poster child' for hiding asteroids," says Alan Harris of the Space Science Institute in Boulder, Colorado.
Similar "synchronised" asteroids may be hiding with periods of very close to two, three, four years and so on, Harris says. Those with periods of about four years pose the greatest risk to Earth, because they would be in sync with both Earth and Jupiter, says Timothy Spahr of the Minor Planet Center in Cambridge, Massachusetts. Such asteroids would be particularly influenced by Jupiter's gravity, which could nudge them onto a collision course with Earth.
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2:10 PM
Beena
4:27 PM
Beena
Ulman Lindenberger, Viktor Müller, and Shu-Chen Li from the Max Planck Institute for Human Development in Berlin along with Walter Gruber from the University of Salzburg used electroencephalography (EEG) to record the brain electrical activity in eight pairs of guitarists. Each of the pairs played a short jazz-fusion melody together up to 60 times while the EEG picked up their brain waves via electrodes on their scalps.
The similarities among the brainwaves' phase, both within and between the brains of the musicians, increased significantly: first when listening to a metronome beat in preparation; and secondly as they began to play together. The brains' frontal and central regions showed the strongest synchronization patterns, as the researchers expected. However the temporal and parietal regions also showed relatively high synchronization in at least half of the pairs of musicians. The regions may be involved in processes supporting the coordinated action between players, or in enjoying the music.
"Our findings show that interpersonally coordinated actions are preceded and accompanied by between-brain oscillatory couplings," says Ulman Lindenberger. The results don't show whether this coupling occurs in response to the beat of the metronome and music, and as a result of watching each others' movements and listening to each others' music, or whether the brain synchronization takes place first and causes the coordinated performance. Although individual's brains have been observed getting tuning into music before, this is the first time musicians have been measured jointly in concert.
Source <www.sciencedaily.com>
9:48 PM
Antoine
9:27 PM
Beena
11:06 AM
Beena
9:31 AM
Beena
As the human body ages, it loses bone. Individual cells lose something equally vital. Every time one divides, it sheds tiny snippets of DNA known as telomeres, which serve as protective caps on the ends of chromosomes. After perhaps a hundred divisions, a cell's telomeres become so truncated that its chromosomes--site of the cell's genes--begin to fray, rather like shoelaces that have lost their plastic tips. Eventually, such aged cells die--unless, like "immortal" cancer cells, they produce telomerase, an enzyme that protects and even rebuilds telomeres. Scientists have long dreamed of drugs that would inhibit the immortalizing enzyme because, observes M.I.T. biochemist Robert Weinberg, "then maybe cancer cells would run out of telomeres and just poop out."
Wishful thinking? Maybe not. In papers published just a week apart in the journals Science and Cell, two teams of researchers--one led by Nobel-prizewinning biochemist Thomas Cech of the University of Colorado, the other by M.I.T.'s Weinberg--have announced a breakthrough that could help bring about such a drug. Both teams have managed to clone a gene that controls the activity of the telomerase enzyme in human cells. That could set the stage for development not only of inhibiting drugs but also of substances that switch on the enzyme--which might help combat degenerative diseases associated with aging.
Such possibilities, to be sure, are speculative, but that didn't stop Wall Street, where the stock of Geron Corp., a small biotech company based in Menlo Park, Calif., that helped Cech's group discover the gene, more than doubled, to 1618 a share. In fact, Geron researchers have been looking for antitelomerase compounds for several years, using indirect-screening methods. Because tumor cells--the main source of the human enzyme--produce it in vanishingly small quantities, the scientists lacked pure telomerase, which could have sped the search for drugs that might be used against it.
With the new gene in hand, the researchers should be able to churn out at will the protein for which it provides the genetic blueprint. That protein, they believe, is telomerase's most important building block. "For us," exults Calvin Harley, Geron's chief scientist, "it's like having access to an organism's brain."
The new protein, it turns out, bears an intriguing resemblance to an enzyme produced by HIV, the retrovirus that causes AIDS. Indeed, the AIDS drug AZT has already been shown to inhibit telomerase activity. But the viral enzyme and the human enzyme, says Colorado's Cech, are only 20% identical, which explains why AZT is not an ideal telomerase inhibitor. "What we want," he declares, "is a compound that fits telomerase the way a hand fits a glove."
The odds that such a compound will materialize now seem high. But experts caution that it could take years before the first telomerase inhibitors are ready to be tested on humans to determine if they'll have any serious side effects--or if they'll actually inhibit tumor growth. Such questions are perhaps one reason Geron's stock leveled off at week's end, closing at 12 1/4 a share.
9:12 AM
Antoine
5:04 AM
Antoine
4:29 AM
Antoine
