1/31/11
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vaata veel1/28/11
Inimesed võisid lahkuda Aafrikast arvatust varem
Jean-Louis Santini kirjutab Discovery Channelis, et Araabia Ühendemiraatides maa seest välja tulnud iidsed tööriistad viitavad tugevalt ses suunas, et varajased inimesed lahkusid Aafrikast seniarvatust oluliselt varem.
Using a technique called luminescence dating to determine the age of the toolkit, scientists believe it is between 100,000 and 125,000 years old, according to lead author Simon Armitage from Royal Holloway college, University of London. Most other evidence has suggested modern humans left Africa around 60,000 years ago and made the trek along the Mediterranean Sea or the Arabian Coast, but some finds in recent years have suggested otherwise.
Using a technique called luminescence dating to determine the age of the toolkit, scientists believe it is between 100,000 and 125,000 years old, according to lead author Simon Armitage from Royal Holloway college, University of London. Most other evidence has suggested modern humans left Africa around 60,000 years ago and made the trek along the Mediterranean Sea or the Arabian Coast, but some finds in recent years have suggested otherwise.
1/27/11
Kuidas peatada vananemist
Neil Bowlder kirjutab BBCs viimasel ajal tehtud teadusavastustest, mis aitavad meil senisest paremini mõista vanenemisega kaasnevaid protsesse ning neid aeglustada või peatada.
Scientists are slowly unlocking the secrets of ageing, and some suggest treatments may soon be at hand to slow or even reverse the ageing process. But what can science really achieve, and what are the dangers of meddling with our biological clocks? Could such treatments induce cancers in humans, for example, and what about the world's burgeoning population and the West's "pension time bomb"?
Scientists are slowly unlocking the secrets of ageing, and some suggest treatments may soon be at hand to slow or even reverse the ageing process. But what can science really achieve, and what are the dangers of meddling with our biological clocks? Could such treatments induce cancers in humans, for example, and what about the world's burgeoning population and the West's "pension time bomb"?
1/26/11
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vaata veelKui antioksüdandid on eluohtlikud
Sharon Begley tutvustab Newsweekis viimase aja teadusleide, mis lükkavad ümber laialt levinud arvamuse, mille kohaselt on antioksüdandid universaalsed vananemisevastased ja haigusi ennetavad vahendid, ning toob esile, et vähemalt teatud antioksüdandid näivad koguni enneaegset surmariski tõstvat.
In 2008 the Cochrane Collaboration, an international consortium of scientists who assess medical research, scrutinized 67 studies with nearly 400,000 participants. The goal: to determine whether antioxidant supplements reduce mortality in either healthy people or in people with cardiovascular, neurological, rheumatoid, renal, endocrine, or other diseases. Conclusion: “We found no evidence to support antioxidant supplements for primary or secondary prevention, [and] Vitamin A, beta-carotene, and vitamin E may increase mortality.” In analyses of antioxidant supplements and Lou Gehrig’s disease, Alzheimer’s or mild cognitive impairment, and lung cancer, the Cochrane scientists’ verdict was the same: no, no, no, and no. And each analysis had an alarming refrain about increasing overall mortality.
In 2008 the Cochrane Collaboration, an international consortium of scientists who assess medical research, scrutinized 67 studies with nearly 400,000 participants. The goal: to determine whether antioxidant supplements reduce mortality in either healthy people or in people with cardiovascular, neurological, rheumatoid, renal, endocrine, or other diseases. Conclusion: “We found no evidence to support antioxidant supplements for primary or secondary prevention, [and] Vitamin A, beta-carotene, and vitamin E may increase mortality.” In analyses of antioxidant supplements and Lou Gehrig’s disease, Alzheimer’s or mild cognitive impairment, and lung cancer, the Cochrane scientists’ verdict was the same: no, no, no, and no. And each analysis had an alarming refrain about increasing overall mortality.
1/25/11
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