Friday, March 23, 2007

Do animals need to sex to create variety?

The Times Online has an interesting article about an organism which survived 100 million years without sex.

Researchers say that their study "refutes the idea that sex is necessary for diversification into evolutionary species".


From the article:

"A tiny creature that has not had sex for 100 million years has overturned the theory that animals need to mate to create variety. Analysis of the jaw shapes of bdelloid rotifers, combined with genetic data, revealed that the animals have diversified under pressure of natural selection. Researchers say that their study "refutes the idea that sex is necessary for diversification into evolutionary species".


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Creature that has not had sex for 100m years

By:  Lewis Smith, Environment Reporter

(From The Times, March 20, 2007)

Thursday, March 22, 2007

Going on a 'mental time travel' ?!

If you thought memory was all about making a record of the past, think again!

Your brain is equipped with a time machine that can take you forwards and backwards at will.


Without paying a penny you can travel backwards or forwards in time in your mind's eye - what is known as "mental time travel". One of these visions - the backward travel - is about really happened things and the other -  the backward travel - is about fantasizing things.....but that too will have a time-line assigned by your mind which makes it both the instances very similar. In simple terms, you are able to 'recall' your future as you would normally do about your past!


You can recall what happened yesterday, like where you have been, what you ate, whom you have talked to in the morning, what you did in the evening. Same way you 'recall' your tomorrow like where you will be, what you will be eating, to whom all you will be talking in the morning, what you will be doing in the evening. That's what 'mental time travel' is all about. Now experiment with yourself, travel to the newer meadows of your future on your 'mental time machine', explore the future!


Happy journey!

Want to postpone your pregnancy?.....Egg freezing comes to your rescue!

Now women around the world can hopefully stop their biological clock for a decade or more by putting their eggs on ice. Recent advances in freezing techniques (cryo-preservation) suggest that egg survival and fertilisation success rates for once-frozen eggs may be as good as for fresh ones. Egg-freezing is still a comparatively untested technology, but now it is possible that women can 'bank' their healthy eggs for a while - till they feel its time - can have her eggs thawed and use routine IVF procedures to get pregnant.

"A woman is more likely to get pregnant at 40 with one of her eggs frozen in her early 30s than with her 40-year-old eggs" says Gillian Lockwood, medical director of Midland Fertility Services in Aldridge, West Midlands, in the UK.

Egg freezing: A reproductive revolution

By: Rachel Nowak

(21 March 2007, news service)


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Monday, March 19, 2007

The "string-net liquid" nature of Universe and a new state of matter - 'Herbertsmithite'

Xiao-Gang Wen at the Massachusetts Institute of Technology and Michael Levin at Harvard University have come up with a prediction for a new state of matter, and even a visualisation of the nature of space-time itself. Levin presented their work at the Topological Quantum Computing conference at the University of California, Los Angeles, early this month.

Their 25-year-old experiment is turning everything we know about matter upside down. In their theory elementary particles are not the fundamental building blocks of matter. Instead, they emerge from the deeper structure of the non-empty vacuum of space-time. They predict that the entire universe could be made of a string-net liquid.

Joel Helton's group at MIT might have found a candidate for such a material: a dark green crystal called " herbertsmithite", found in the mountains of Chile in 1972. They have named it after a mineralogist they really admired, Herbert Smith". They didn't realise the potential herbertsmithite would have for physicists years later.

Herbertsmithite is unusual because its electrons are arranged in a triangular lattice. Normally, electrons prefer to line up so that their spins are in the opposite direction to that of their immediate neighbours, but in a triangle this is impossible - there will always be neighbouring electrons spinning in the same direction. Wen and Levin's model shows that such a system would be a string-net liquid.

The Herbertsmithite existing in nature contains impurities that disrupt any string-net signatures. So Helton's team made a pure sample in the lab. The team measured the degree of magnetisation in the material, in response to an applied magnetic field. If herbertsmithite behaves like ordinary matter, they argue, then below about 26 °C the spins of its electrons should stop fluctuating - a condition called magnetic order. But the team found no such transition, even down to just a fraction above absolute zero!

This could be just a starting point for still newer forms of matter!

More >>>>

The universe is a string-net liquid

15 March 2007, New Scientist

By: Zeeya Merali