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| SCIENCE & TECHNOLOGY |
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A misbehaved planet
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Varied uses of gene pharming The term pharming comes from a combination of words “farming” and “pharmaceuticals” and is a welding of the most basic methods of agriculture with the most advanced DNA technology.
The most commonly used animals for gene pharming are cows, sheep, goats, mice, pigs, chickens, rabbits, swines etc and these animals produce the proteins for medicine in their milk, urine, blood or eggs which are later on purified.
Such animals carrying human genes for therapeutic proteins of interest are technically called as transgenic or pharmed animals. Several pharmed proteins are either in development or in human trials. A New Jersey based biotech company has developed transgenic pigs that produce human hemoglobin. The blood proteins, namely the factor IX and factor VIII, needed by the hemophiliacs are nowadays produced in transgenic pigs, sheep and cows in UK. A key advantage of animal derived hemoglobin and other blood components is their freedom from human pathogens, HIV, hepatitis and blood contaminations which one may contact while transfusions. The scientists have also developed a transgenic goat whose milk contains a protein that could conceivably be used to immunise against malaria. It stirs one’s imagination to think that millions of people could one day be protected against the devastating effects of malaria simply by drinking a glass of goat’s milk containing that protein. The human drug tissue plasminogen activator (tPA) that is of great clinical use to dissolve blood clot and treat myocardial infarction (MI) is also under developmental stages in animals such as sheep and goats. In an attempt to treat osteoporosis, a biotech company has developed transgenic rabbits to produce human hormone called calcitonin, which plays a vital role in calcium absorption in the body. Lactoferrin, a major protein found in human milk that functions in iron uptake in nursing infants, has been produced in transgenic dairy cows in Netherlands. It would be useful in treating iron deficiency anaemia and as an infant formula additive. The cows that secrete (in their milk) the human proteins such as albumin and collagen I and II have been pharmed in United States. The human albumin is used in patients suffering from traumatic injuries such as burns whereas collagen would be used for tissue repairs and in patients suffering from rheumatoid arthritis. DNA technologists have also developed transgenic cattle that synthesise human defence proteins called antibodies to fight against cancers, and insulin and growth hormones to treat diabetes and growth disorders respectively. At the developmental phase, pharming still requires screening for diseases and viruses of animal origin transferable from animals to humans. Moreover, animal welfare groups and those concerned about ethical implications of pharming questions the development and use of transgenic or pharmed animals. They fear that these animals would be treated as commodities and “walking factories” producing pharmed products in their milk and perhaps organs for transplantation too. Nevertheless, with the current research being conducted in pharming, it is clear that the medical field in near future will see less expensive therapeutic proteins produced in a variety of pharmed animals.
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A misbehaved planet Pluto was quickly heralded as the ninth planet in the solar system when it was spotted on Feb. 18, 1930, by Clyde
Tombaugh, a young amateur astronomer at Lowell Observatory. It still holds that title today, if somewhat tenuously. “It’s a misbehaved planet if you want to think about it as a planet,” said Neil deGrasse Tyson, director of New York’s Hayden Planetarium at the American Museum of Natural History. Tyson provocatively removed Pluto from his exhibit of planets five years ago, lumping it instead with a belt of comets at the edge of the solar system. “I still have folders of hate mail from third-graders,” he said. Pluto was discovered in a search for a theoretical ninth planet. The 26-year-old Tombaugh was given the assignment. Had he not been so attentive, he might have missed Pluto as he stared through an eyepiece while switching back and forth between photographic images of the night sky over northern Arizona. But he believed right away the recurring speck he saw was the elusive Planet X later called Pluto. Generations of schoolchildren grew up memorizing solar system charts that included Pluto. But shortly after Tombaugh died in 1997, some astronomers suggested that the International Astronomical Union should demote the tiniest planet.
— AP
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This Universe
Q. What is the concept behind Zero Point Energy? Can it be used to propel a spacecraft to the speed of light?
A. I find some of your questions come from the science fiction movies you see or books you read. These movies or books borrow a lot of terminology from the present day science and then embark upon their own flights of fancy. This is enjoyable and often very useful. But all the romance depicted there cannot be taken seriously. Let me see if I can make the basic ideas behind the term Zero Point Energy somewhat comprehensible. Some basic concepts and ideas are involved here. When you take some material, say a simple gas and cool it down, you would progressively reduce the thermal energy of its molecules. The energy content would go on reducing while the gas turns into liquid and then perhaps a solid. You go on cooling till you approach a temperature close to zero degrees Kelvin. You cannot go below that temperature. This temperature is defined as Absolute Zero because all thermal motion comes to a stop. The fact that you cannot cool the sample any further inversely implies that you cannot extract any more energy from it. It is another matter that Absolute Zero may never be obtained. Here other considerations come into play. These derive from quantum statistics and the uncertainty principle. If the particles of the material under consideration are identical bosons (in other words they have integral spins), they can all be in the same state. The same state implies that they can have the same position and momentum and there is a possibility of forming a new state of matter known as a Bose-Einstein condensate. Such a state has been realised during last few years by using sophisticated cooling and confinement techniques. Of course, we still have to honour the uncertainty principle — this manifests itself in intriguing and interesting ways that we cannot consider in this brief and rudimentary discussion. But let us now move to the exact question that had been raised. For bosons, there is no zero point energy. But now consider identical particles with half-integral spin. Such particles are subject to different statistics. This is controlled by the Pauli Exclusion Principle that states that only one particle can occupy a well-defined quantum state. If one particle is sitting in the lowest energy state, there is no room in that state for another one coming in with the same spin and angular momentum. It will be asked to go to the next higher energy state, no matter how low the temperature of the system. For example, an electron in an orbit of zero angular momentum around a nucleus will welcome another one of its kind only if it has the opposite spin direction. After that there is no more room in that energy state. If we were to think of a gas of neutrinos cooled to a temperature of absolute zero, they will not all lie in the lowest zero energy state because of this “untouchability” principle! Many of them will have to remain in higher energy states. Depending on the density of the neutrino gas, the Fermi energies of some of these particles could be significant. This is the energy we call the Zero Point Energy. I do not see how this energy can be used in any significant way, let alone accomplish the feat of accelerating a spacecraft to high velocity and energy. That imaginary concept is best left to the domain of juvenile science fiction stories. |
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X-rays become laser-like Radiologists and biologists have been dreaming — ever since the discovery of lasers — of a compact laboratory source emitting X-rays in one direction in a laser-like beam. Such a source would permit X-ray images to be recorded with far higher resolution at vastly reduced dose levels, allowing early-stage cancer diagnosis at dramatically reduced risk. Microscopes furnished with this source would make nanometer-sized biomolecules perceivable in their natural surrounding (in vivo). Researchers at Vienna University of Technology, the University of Würzburg, the University of Munich and Max Planck Institute of Quantum Optics demonstrated the first source of laser-like X-rays at a wavelength of 1 nanometer with a compact laboratory apparatus in an experiment in Vienna, funded by the Austrian Science Fund. Stone-Age tools
Ancient Chinese people may have used diamonds to polish their stone axes to mirrorlike finishes, according to a new analysis. Other than pushing back by several thousand years the date for the first known use of diamonds, the findings also suggest that Neolithic Chinese societies were more technologically advanced than previous studies had shown. Some sections of the axe surfaces are almost as smooth as some silicon wafers used to make computer chips, says Peter Lu, a physicist at Harvard University. “Somehow, Stone Age people . . . were able to make something smooth enough that you could pattern a circuit on it,” he says. In an attempt to discover how the polishing was done, Lu obtained four ceremonial burial axes from the tombs of two Neolithic Chinese societies — the Liangzhu culture and the Sanxingcun culture — that once inhabited parts of southern China near what is now Shanghai. The stone axes had been dated by others to between 4000 and 2500 B.C. Primary driving force A geomicrobiologist at Washington University in St. Louis has proposed that evolution is the primary driving force in the early earth’s development rather than physical processes, such as plate tectonics. Carrine Blank, Ph.D., Washington University assistant professor of geomicrobiology in the Department of Earth and Planetary Sciences in Arts and Sciences, studying Cyanobacteria, bacteria that use light, water, and carbon dioxide to produce oxygen and biomass, has concluded that these species got their start on earth in freshwater systems on continents and gradually evolved to exist in brackish water environments, then higher salt ones, marine and hyper saline (salt crust) environments. |
With the advent of DNA technology, the scientists’ widest imaginations could be accommodated because they could now intervene directly in the genetic fate of living beings. They discovered for example “Gene Pharming”, whereby the researchers could transplant human genes into animals and coax the genes to produce human proteins having therapeutic value. These therapeutic proteins have a wide range of uses in medicine as vaccines, defence proteins, hormones or to replace missing enzymes in the body.
It’s been 75 years since the discovery of Pluto, but it remains a mystery. Perhaps in another 10 years some of its secrets will be revealed when a space probe gets close enough for a good look. 