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A living
touch to computing
Burgers from a lab? Study says it’s possible Fungi fight malaria Brain pacemaker could ease depression New Products and Discoveries Prof Yash
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A living
touch to computing In their quest to give a new dimension to the process of computing, researchers have zeroed in on living molecules as potential candidates for computer switches. Clearly and apparently, molecular switches hold the promise of not only reducing the size of the computer but also increase its speed. Indeed, a hybrid computer in which living molecules work in tandem with semiconductor devices is no more in the realm of science fiction. Scientists from around the world have found the bacterial protein of bacteriohodopsin a potentially promising candidate for the computer switches. Because it functions as a light driven pump, its fan serve as a veritable optical memory device. It is now known that if a number of bacteriohodpsin molecules are arranged in a three-dimensional fashion, high speed, high density, low cost memory devices with huge capacity can be realised. Such memory devices offer over 300-fold increment in the storage capacity in comparison to their two-dimensional counterparts. Right at the moment, computer scientists are increasingly focusing on building the socalled biochips which has been found to be highly efficient in processing enormous volumes of data, quickly and efficiently. However when biochips are used in a computer, the application of energy becomes a nagging problem. For the optimum use of biochips, the energy source in, form of ATP (adenosine triphosphate) becomes essential. That is major challenge in developing a computer in which living proteins function as vital components. Of course, much ground has been covered towards developing world’s first functional biological computer endowed with discriminative faculties. A team of researchers headed by Dhud Shapiro, a Professor at Weizman Institute in Jerusalem, has already engineered a computing device based on the molecules of DNA (Deoxyribose Nucleic Acid), the master molecule and the basic blueprint of life. This microscopic computer makes use of enzymes as hardware which in turn coaxes DNA molecules to transform themselves into corresponding software. The living cell contains incredible molecular machines that manipulate information encoding molecules in ways that are very similar to
computation, “observes Shapiro. He also drives home the point that a trillion molecules acting together can perform a billion operations per second with 99.8 per cent accuracy. However, the DNA computer requires very little power to operate. An operational version of the DNA computer could help medical researchers Zero in on the abnormal biochemical changes taking place in the human body. In the staggeringly complex and intricate process of protein synthesis made possible by DNA, researchers behold the possibility of developing a truly parallel computer. In the baffling chemical structure and functions of the double helix DNA nature has designed a near perfect supercomputer. This is so because DNA can store, retrieve and process billions of bits of complex data in its own inimitable way. As and when an operational DNA computer becomes a reality, it would be a billion times more energy efficient that an ordinary computer. Further, in contrast to the conventional computer, it would need a trillionth of space to store information. |
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Burgers from a lab? Study says it’s possible
While NASA engineers have grown fish tissue in lab dishes, no one has seriously proposed a way to grow meat on commercial levels. But a new study conducted by University of Maryland doctoral student Jason Matheny and his colleagues describe two possible ways to do it. Writing in the journal Tissue Engineering, Matheny said scientists could grow cells from the muscle tissue of cattle, pigs, poultry or fish in large flat sheets on thin membranes. These sheets of cells would be grown and stretched, then removed from the membranes and stacked to increase thickness and resemble meat. Using another method, scientists could grow muscle cells on small three-dimensional beads that stretch with small changes in temperature. The resulting tissue could be used to make processed meat such as chicken nuggets or hamburgers. “There would be a lot of benefits from cultured meat,” Matheny said in a statement. “For one thing, you could control the nutrients.” Meat is high in omega-6 fatty acid, which is desirable, but not in large amounts. Healthful omega-3 fatty acids, such as those found in walnuts and fish oils, could be substituted. “Cultured meat could also reduce the pollution that results from raising livestock, and you wouldn’t need the drugs that are used on animals raised for meat,” Matheny said. Raising livestock requires million of gallons of water and hundreds of acres of land. Meat grown from tissue would bypass those requirements. The demand for meat is increasing worldwide, Matheny said. “China’s meat demand is doubling every 10 years,” he said. “Poultry consumption in India has doubled in the last five years.” Writing in this month’s Physics World, British physicist Alan Calvert calculated that the animals eaten by people produce 21 per cent of the carbon dioxide that can be attributed to human activity. He recommends people switch to a vegetarian diet as a way to battle global warming. “Worldwide reduction of meat production in the pursuit of the targets set in the Kyoto treaty seems to carry fewer political unknowns than cutting our consumption of fossil fuels,” he said in a statement. —
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Fungi fight malaria Certain fungi not only kill mosquitoes but also can reduce the likelihood of them transmitting malaria before they die, according to UK-based researchers. Spraying walls or cloths with spores of a fungus that kills mosquitoes could greatly reduce malaria transmission, according to two studies published in the recent issue of Science. Researchers led by Matt Thomas exposed Anopheles stephensi mosquitoes to the fungi and they found that the mosquitoes were 80 times less likely to transmit malaria. The mosquito transmits malaria to humans but in this study carried a form of malaria that infects rodents, it said. The researchers assessed eight strains of two fungal species: Beauveria bassiana and Metarhizium anisopliae. The fungi kill malarial mosquitoes before they can transmit the parasite. The researchers sprayed cardboard pots with fungal spores suspended in oil, then 24 hours later introduced mosquitoes that had taken a blood meal and left them for two weeks, the report said. In six of the eight tests, more than 80 per cent of the mosquitoes died. Death is not always quick, but it does not need to be, the researchers said. Mosquitoes cannot transmit malaria until about two weeks after picking up the malaria parasites with a blood meal. The fungus also affects mosquitoes’ ability to feed, making them less likely to spread malaria.
— PTI
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Brain pacemaker could ease depression Patients suffering from severe depression who have not responded to other treatments may be helped by deep brain stimulation, researchers say.
The treatment, which is like a pacemaker for the brain, uses electrodes implanted in the brain to switch off or interrupt electrical circuits linked to depression. In four out of six patients who failed on all other treatments, deep brain stimulation relieved their depression. “Patients would experience an immediate shutdown of a negative state,” Dr Helen Mayberg, a neurologist at Emory University School of Medicine in Atlanta, Georgia told a news conference. The technique was developed for Parkinson’s disease patients but Mayberg and her colleagues have adapted it for patients with severe depression. “It is the most exciting new development in terms of the treatment of depression in 10 years,” said David Nutt, the head of psychopharmacology at Bristol University, England. Using brain-imaging techniques, the scientists implanted electrodes deep into an area of the brain that they had linked to depression while the patients were under a local anaesthetic. As their brains were stimulated, the patients, who were awake, were told to explain what they were feeling. They described a sense of calmness or easiness. There were no side-effects, according to the researcher. “The important thing to realise about brain stimulation is that it isn’t just that you are exciting the brain, you are using electricity to basically tune or modulate a circuit,” Mayberg said. “It is the turning off of a negative state.” In patients who responded to the deep brain stimulation, a device similar to a pacemaker was implanted to keep simulation constant. Two years after the experiment, the patients are responding well. “These are extremely encouraging first results,” said Mayberg. The researchers, who are planning further studies, said the therapy would be suitable for patients with the most severe and debilitating depression who have failed to respond to all other treatments.
— Reuters
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New Products and Discoveries In March 2002, an international team of scientists pumped hot water down a 1,200-metre well located at the edge of the Mackenzie River Delta in northwestern Canada. The water seeped into the pores of the perpetually frozen sediments, melting icelike crystals along its path. These were no ordinary crystals, but frozen cages of water molecules filled with methane, the main constituent of natural gas. The structures had formed millennia ago and now reside in layers deep below the permafrost. As the crystals melted, the natural gas escaped and bubbled to the surface to fuel a flame rising high above the white Arctic landscape. “It was a landmark effort,” says Dendy Sloan of the Colorado School of Mines in Golden. It produced the first documented field demonstration that natural gas could be released from the crystalline substances known as methane hydrates. Lake-like feature on Titan Scientists are fascinated by a dark, lake-like feature recently observed on Saturn’s moon Titan. NASA’s Cassini spacecraft captured a series of images showing a marking, darker than anything else around it. It is remarkably lake-like, with smooth, shore-like boundaries unlike any seen previously on Titan. “I’d say this is definitely the best candidate we’ve seen so far for a liquid hydrocarbon lake on Titan,” said Dr. Alfred McEwen, Cassini imaging team member and a professor at the University of Arizona, Tucson. The suspected lake area measures 234 km long by 73 km wide, about the size of Lake Ontario, on the U.S. Canadian border. Butterflies go for sparkle Instead, females are attracted to the “sparkle” created by the ultraviolet reflectivity of the pupils, the white circles at the centre of eyespots, according to new research from University at Buffalo biologists. The research, be published in Proceedings of the Royal Society B: Biological Sciences, overturns previous work indicating that larger eyespots might be considered more desirable by female butterflies. |
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THIS UNIVERSE Q Why do we have a pair of kidneys when a man can stay perfectly healthy on one kidney? Does it constitute spare capacity, in case of failure? If so, why has evolution not provided additional copies of other organs as well? Alternatively, will evolutionary pressures cause the elimination of one kidney in the future? Are both kidneys used at the same time? A I am no expert in this area, but it has often been found that a spare kidney was good idea. I think both kidneys are used in the normal course, even though, as you rightly mention, it is possible to live a reasonably normal life with just one; this fact makes live kidney donations to compatible recipients possible. We do have lots of active “spares” in our body; eyes, ears, hands and legs (which all exist in pairs) come to mind. It’s clear that survival is possible (admittedly with less efficiency) upon loss of one of the pair. Different survival strategies have evolved in other organs to deal with adversity. For example, more than 80 per cent of pancreatic tissue needs to be destroyed before a drop in insulin production is seen (indicating a tremendous spare capacity). Also, adult liver tissue retains the capacity to regenerate after destruction due to injury or surgery. Two hearts might have been a good idea, but the one we have is good enough to last if only we live properly — eat responsibly and exercise adequately. Two brains might have been problematic — all of us would be schizophrenic! On a more serious note, you are perhaps aware that biotechnologists dream of one day being able to grow
synthetic organs for transplant purposes, forever ending the scarcity that deprives so many. I do not know what the future holds. I would just like to reiterate, however, that if we treat our bodies well, they are designed to last us a lifetime!! Q What makes dog man’s best friend? Why do they behave like humans do? A What an amusing statement! I do not think one can say that dogs behave in ways similar to humans. They have been domesticated over a long period of time and we get along because we are somewhat complimentary. They are dependent on us. They have some capabilities that are much superior to ours — for example their sense of smell. They, like many animals, have deeply ingrained territorial instincts and therefore can be trained to guard us from intruders. They are (or can be trained to be) more affectionate towards us than to even their own kind. It has to be recognised that what we call “training” is based on a system of rewards for behaving the way we like, and includes sharpening the faculties that are useful to us.
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The
semiconductors based present genre conventional computers are fast
reaching their peak in terms of speed and power. As such researchers
around the world are on the look out for “materials and substances”
that could turn dumb, number crunchers into super fast. ultrasmart
thinking machines.
Laboratories using new tissue engineering technology might be able to produce meat that is healthier for consumers and cut down on pollution produced by factory farming, researchers have said. 
Size doesn’t matter, at least not the size of the eyespots on a male butterfly’s wings when female butterflies consider potential mates.