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| SCIENCE & TECHNOLOGY |
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“Virgin conception”
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Scientists have created the first human embryos in Britain by a technique of “virgin Each embryo came about as a result of parthenogenesis, when an egg divides without being fertilised into a ball of cells that develops in effect an early embryo called a blastocyst. Paul de Souza, the study’s principal investigator at the Roslin Institute in Edinburgh, said that although the aim was to harvest stem cells from the embryos, efforts to do this had so far not been successful. “We have made half a dozen blastocyst. We have not at present got embryonic stem cells, that continues to be our ambition,” Dr de Souza told the British Association for the Advancement of Science meeting in Dublin. Parthenogenesis-which literally means virgin birth-is a common form of asexual reproduction in many animals but not in mammals, the group to which humans belong. Dr de Souza said there was no intention of implanting the embryos into the womb of a woman and that his government licence from the Human Fertilisation and Mariology authority was strictly for research. “If we don’t put these artificial conceptuses into a uterus, they will go nowhere. They will not result in a foetus, they will not result in a life,” he said. The announcement of the first human embryos created by parthenogenesis is likely to be criticised by “pro-life”groups who oppose all research that involves creating human embryos for research purposes, he said. The scientists at the Roslin Institute, where Doly the sheep was cloned, used about 300 eggs taken from the ovaries of women undergoing an operation to make them sterile who had given their consent. About half the eggs matured successfully in the laboratory and about 5 per cent of these divided several times to produce a blastocyst, he said. “We need a blastocyst to recover embryo stem cells and our success rate in recovering embryo stem cells is about one in ten,” Dr de Souza said. “I think it is more of a technical challenge to get stem cells as distinct from a biological challenge. — By arrangement with
The Independent, London |
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Electric bicycle and scooter
There is good news for those who let out a curse, after paying through their nose for fueld and then inhaling noxious fumes from gases from exhausts on the way to their work place. They could soon be travelling, beating pollution and rising fuel costs with a battery operated bicycle.
Shreyas Rane, a student at the National
Institute of Design (NID), Ahmedabad, hs created an electric bicycle, named “E-GO”. This bicycle, whose prototype is now ready and could hit the roads by the middle of next year, is the culmination of the quest between a cycle and a motorised vehicle. Shreyas worked for six months on the project, commissioned by Chennai based TI Cycles of India. E-Go would be priced between Rs 6,000, and Rs 8,000 can run up to 25 km per hour, much faster than the average bicycle. It will be powered by three 12-volt sealed batteries that can be recharged, with one charge lasting 35 hours. It will have an intelligent integrated circuit that will indicate battery charge level, been when the charge goes down and even cut off the power supply to the motor when brakes are applied. It was a challenge designing the cycle. With E-Go weighing about 30 kg, compared to a normal cycle that weighs about 12 to 14 kg, the prime concern was to position the centre of gravity so that the balance is maintained. Eko Vehicle, based at Bangalore, have come out with a battery operated electric scooter called Eko-Cosmic, The scooter has a seating capacity of two, can over 50 km on a single charge of the battery and each recharge will cost Rs 3. The battery is fully sealed and needs no maintenance like checking and replenishing distilled water. The Eco-Cosmic comes with a charger that can be plugged into any electric point and it takes four hours for the battery to be fully recharged. The battery has a life of five years. The company plans to set up battery charging points at eight places in Bangalore. The Karnataka Government has extended road tax exemption for the scooter and is considering sales tax exemption. The scooter runs on a DC motor integrated with the rear wheel. Whenever brakes are applied, the motor automatically gets switched off and restarts only when the accelerator is turned. The vehicle costs Rs 25,000. Advantages of electric vehicles are well-established, but they need an assured electricity supply from the electricity boards for charging when at home. |
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This Universe
Why does the sun look bigger when it is low on the horizon than when it is overhead? This observation applies equally to the moon; the moon also looks much bigger when close to the horizon than when it is high in the sky. The consensus is that this universal experience has nothing to do with the physics of seeing or the size or shape of the image. You can easily check that the actual size of the image is the same, independent of the location in the sky. This is very conveniently done for the full moon using nothing more than a transparent scale held at arm’s length with one eye closed. No doubt, you will convince yourself that the actual size of the moon does not change as the moon climbs up in the sky (A NOTE OF CAUTION: IT IS HAZARDOUS FOR THE EYES TO TRY THIS WITH THE SUN, UNLESS YOU USE A CERTIFIED FILTER!!!). In any case, you can take it from me that physics is not fooled by the proximity of the sun (or the moon) to the horizon. But we are. This optical illusion is fundamentally linked with the way our brain interprets images. It uses past experience — some facts, and some prejudices — to give meaning to the visual signals received in the cortex. We are aware of a large number of optical illusions. But the field of psychology is not as certain, or crisp, as mathematics. Two possible explanations have been put forth for this observation; see if they satisfy you. When the sun, or the moon, is near the horizon we see it in the company of other distant objects — buildings, trees, and hills — objects whose sizes our brain is familiar with. These distant objects produce a small image, but the brain is not fooled; past experience tells it how big they really are. A mental amplification process occurs, which justifies and rationalises the sizes of these objects. But the brain is fooled a bit when it gives a similar amplification while assigning a size to the sun — or the moon!
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TRENDS
When it comes to pain control, a dose of positive thinking goes a long way, according to researchers who have found that many of the same brain areas that respond to severe pain also respond to mere expectations of pain. This commonality provides a neural route for the mind to quell pain and could explain the pain-fighting power of placebos, the scientists say.
“Pain emerges from the interaction between signals coming from an injured body region and cognitive information unique to each individual, such as expectations about what that pain will feel like,” says neuroscientist Robert C. Coghill of Wake Forest University School of Medicine in Winston-Salem, N.C. He and his coworkers report their results in the Sept. 6 Proceedings of the National Academy of Sciences.
Mysterious disk of blue stars Astronomers using the NASA/ESA Hubble Space Telescope have identified the source of a mysterious blue light surrounding a supermassive black hole in our neighbouring Andromeda Galaxy (M31). Though the light has puzzled astronomers for more than a decade, the new discovery makes the story even more mysterious. The blue light is coming from a disk of hot, young stars. These stars are whipping around the black hole in much the same way as planets in our solar system are revolving around the sun. Astronomers are perplexed about how the pancake-shaped disk of stars could form so close to a giant black hole.
Farthest bang Seconds after NASA’s Swift satellite recorded a gamma-ray burst on Sept. 4, astronomers’ cell phones buzzed, beepers went off, and an e-mail alert flashed on more than 1,000 computer screens. It was the 68th time that Swift had notified astronomers about a cosmic explosion, and this one didn’t initially appear to be exceptional. But this week, a team of astronomers announced that the burst is the most distant one ever detected, hailing from the long-ago era when galaxies and stars first lit up the heavens. The finding suggests that researchers may soon detect even more distant bursts that will illuminate the epoch before there were massive light-emitting objects such as quasars and large galaxies.
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