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| SCIENCE TRIBUNE | Thursday, August 30, 2001, Chandigarh, India |
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Keep your messages secret Novel use
of microwaves SCIENCE QUIZ
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Stem cell research — promises and potentials THE recent landmark decision by the Bush Administration — in the face of stiff opposition from the Christian fundamentalist groups, Roman Catholic Church, prolife activists, anti-abortion groups and extreme right wing politicians — to continue federal funding for research on "ostern cell lines" could go a long way towards boosting the prospects of stem cell research which holds the promise revolutionising the treatment for a variety of human diseases and disorders, including Alzheimer’s, diabetes, parkinson muscular dystrophy, epilepsy and various forms of mental ailments. Of course, President Bush has directed the National Institute of Health (NIH) to establish a National Human Embryonic Stem Cell Registry which will monitor all federal funded stem cell research to ensure that all recipients of the federal support are in compliance with the regulations.
Biological researchers view embryonic stem cell as body’s early building blocks. Their wonderous ability to transform themselves into virtually any cell type enables the embryo to grow from a round ball of few cells into a fully formed human being. Essentially, stem cells are undifferentiated cells that can evolve into blood, liver, muscle and other cells and could one day be used to repair damaged organs. Biomedical researchers point out that many of the specialised cells in the human body cannot be replaced by natural processes when damaged or diseased. However, there is a widespread optimism that stem cell therapies could open up the possibility of treating many degenerate diseases as well as replacing seriously damaged organs and tissues. But since an adult stem cell may not have the required versatility to recreate many cell types, it may be necessary to manipulate stem cells taken from human embryos and foetuses. It has been established that stem cells have the potential to divide and develop into 200 specialised cells found in the human body. Strongly supported by the British Medical Association, the British Parliament has approved the use of human embryonic stem cells for research. Since Parliament has approved therapeutic cloning, creating cloned embryos would be considered legal. Meanwhile, in a major
breakthrough that could help carry on with the stem cell research
without falling back on embryo and foetal cells, Dr Frede Miller and
his colleagues at the Centre for Neuronal Survival and Brain Tumour
Research Centre at the Montreal Neurological Institute, McGill
University in Canada, have isolated stem cells from the dermis (skin
part) of the adult rodents which would proliferate and differentiate
in culture to produce very different cell types — neurons, blood and
muscle. Human studies have indicated that similar cells are present in
the adult human skin. Scientists believe that this discovery is
important as it has identified an exciting new stem cell from a
noncontroversial source that holds considerable promise for scientific
and therapuetic research.
In a research project carried out by Dr Tracy McIntosh of the University of Pennsylvania, neuron stem cells were shown to improve injured brains in a rodent. Evan Sunder of Harvord Medical School in Boston has reported progress in using stem cells to kill cancerous brain cells. This implies that in the long run, stem cells could be used as a regenerative source for replacement parts and help researchers work on answers to serious medical disorders. In India Dr B.G. Matapurkar of the Maulana Azad Medical College in New Delhi has developed a technique of regenerating organs and tissues from stem cells. This technique has the potential to revolutionise the medical science as it could do away with organs and tissue trans-plants and avoid problems associated with them. Unlike transplant surgeries, no post operative treatment by expensive and at times hazardous immunosuppressants would be required. On another front, researchers at the Technion-Israel Institute of Technology have for the first time succeeded in growing precursors of heart cells from human embryonic stem cells. Another team of Israeli scientists from the same institute have demonstrated that human embryonic stem cells can produce insulin, a result that can signal an important step towards curing Type 1 diabetes which generally arises from the autoimmune destruction of pancreatic islet cells that produce insulin which in turn "unlocks" the cells of the body, allowing glucose to enter and fuel them. According to Dr Lior Gepstein of the
Faculty of Medicine at the Technion-Israel Institute of Technology,
"Embryonic stem cells have advantages over stem cells derived
from adult tissues. For they can proliferate far more than the stem
cells from adults. |
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Keep your messages secret PRIVACY has always been part of our concern. Even as children, we invented secret languages to prevent adults from prying into our affairs. This is nothing new. Codes date back several thousand years and were used by ancient governments. In Mesopotamia and ancient Egypt they used picture writing to hide their communications. In early India, secret writing was more advanced, and the government used secret codes to communicate with a network of spies spread throughout the country. Their ciphers consisted mostly of simple alphabetic substitutions often based on phonetics and some of these were spoken or used as sign language. During World War II, Sweden had one of the most effective code breaking departments in the world. The Americans too had great success at breaking Japanese codes, while the Japanese, unable to break the American codes, assumed that their codes were also unbreakable. Gangsters and terrorists have now evolved their own vocabulary to hide their conversations from police ears and to transmit coded instructions to build and deliver bombs and other deadly weapons as well as to trade in narcotics. Modern business and the conduct of government affairs require that there should be strict protection of vital information against leakage to rival business, criminals, and foreign government agencies. Now when a considerable part of the business is conducted over the Internet and banks make electronic transfers across the world, it is most important that the codes they use cannot be broken. Strong encryption has now become the main tool for maintaining privacy and confidentiality. Powerful computers have made the most sophisticated cryptography nearly hack-proof. Encryption hides the contents of the message by converting it into ciphertext, and only the proper key can manage the decryption. Interestingly enough, it now becomes a battle of wits between the cryptographers who devise new methods of encrypting messages, and cryptanalysts who practice the art of cryptanalysis, which is the art of deciphering encrypted communications without knowing how it was coded. Sweden had the most effective cryptanalysis department during World War II. It is well publicised that a British group, working with Polish escapees, broke the German Enigma code that used a mechanical device to encode messages. This was perhaps the first time a computer was used to encrypt data. The first attempts at coding used a simple technique where a series of steps or algorithms were formulated for encryption. This method is now obsolete. In most applications, modern cryptography is done with computer software. Computers or specialised hardware devices execute strong and specially designed cryptographic algorithms. All modern algorithms use a "key" to control encryption and decryption. A message can be decrypted only if the key matches the encryption key. Symmetric or secret key algorithms use the same key for locking and unlocking the message, while asymmetric, or public key algorithms use different keys for encryption and decryption. The decryption key cannot be derived from the encryption key. While the encryption or public key is available to the public, only the proper person who has the decryption or secret key can decipher the message. A thief may try all possible keys in sequence in order to break any encrypted document but the effort increases vastly with the length of the key. A 32-bit key takes a billion steps, something that perhaps a personal computer can do, but with the present state of the art in computer technology, a 128-bit key cannot be broken into for a long time. Generally, symmetric algorithms are much faster to execute than asymmetric ones. Symmetric and asymmetric algorithms are often used together in hybrid encryption, so that a public-key algorithm is used to encrypt a randomly generated encryption key, and the random key is used to encrypt the actual message using a symmetric algorithm. Descriptions of public-key algorithms that can encrypt messages are freely available. Cryptanalysis is the art of deciphering encrypted communications without having access to the proper keys. It is quite often possible to make guesses about the plain text. The cryptanalyst knows or can guess the plain text for some parts of the ciphertext. The task is to decrypt the rest of the ciphertext blocks using this information. In the last few years, small mobile crypto devices have come into widespread use. By making very fine measurements of the power consumption, and radiation patterns of the device doing encryption, hackers can break into their encrypted messages. Quantum mechanics has been applied to the field of quantum cryptography, as it has the potential to offer unbreakable security. Many successful experimental implementations of quantum cryptography have been already achieved. The coded message and the key are transmitted as particles of light (photons) and the encryption is contained in the way the light is polarised. The information therefore travels as a series of polarised photons. The sender and the receiver each receive one of a pair of "entangled" photons — photons whose polarisation states are interdependent. When they measure the polarisation sequences, the key is established. A hacker who makes a measurement on the photon sent to sender cannot avoid affecting the photon observed by the receiver, because of the quantum entanglement. An attempt to intercept the key therefore changes the sequence of polarised photons and so the receiver is aware of the intrusion. So far, this method was implemented only over short distances, because as the photons travel, random disturbances spoil the correlation between the photons. Scientists have now found a way to keep such quantum messages readable over long transmission distances. A new and simpler method for entanglement purification has been found. a special kind of mirror that redirects two incoming photons depending on their polarisation state, generates some highly entangled states that can be used to transmit and receive the key. The degradation of entanglement is compensated by simply sending more photon pairs: the beamsplitter device ensures that at least some of these are registered by receiver and sender as highly entangled, and so are reliable for transmitting the key, even over long distances. This has now opened up the implementation of long-distance quantum communication significantly.
Cryptography has now become essential
to information systems. The public is now aware that it is as safe as
the time honoured method of signatures, thumb print and other methods
of identification fairness, accuracy, and confidentiality are assured.
Cryptography can prevent fraud in electronic commerce and assure the
validity of financial transactions as well as prove your identity or
protect your anonymity. As commerce and communications continue to go
more and more electronic, cryptography will become more and more
important. PTI |
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Novel use of microwaves IN a novel approach, researchers at the Indian Institute of Science (IISC) in Bangalore have for the first time synthesised complex electrode materials using the same microwave radiation used to heat food in the kitchen. "The microwave route is simple and fast and should prove to be very attractive for large-scale production," KJ Rao, leader of the research team, said a report in Newsindia published by the international science journal Nature. In their latest work, Rao’s team has reported synthesis of electrode materials required for lithium batteries by the microwave route. Earlier, the team had used microwaves for direct synthesis of silicon carbide (an industrial ceramic widely used as an abrasive), molybdenum disilicide (employed in making high temperature heating elements) and barium titanate which is a transducer.
The report said the Bangalore scientists have synthesised gallium
nitride, used for making blue lasers and aluminum nitride, an
electronic material through this novel route. PTI |
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NEW PRODUCTS & DISCOVERIES SINGLE- MOLECULE COMPUTER IBM researchers have announced they have created and demonstrated the world’s first logic-performing computer circuit within a single molecule, which may someday lead to a new class of smaller and faster computers that consume less power than today’s machines. The IBM team made a "voltage inverter" — one of the three Fundamental logic circuits that are the basis for all of today’s computers — from a carbon nanotube, a tube-shaped molecule of carbon atoms that is 100,000 times thinner than a human hair. This Atomic Force Microscope image shows the design of an intra-molecular logic gate. A single carbon nanotube (shaded) is positioned over gold electrodes to produce two p-type carbon nanotube field-effect transistors in series. The device is covered by an insulated layer (called PMMA) and a window is opened by e-beam lithography to expose part of the nanotube. Potassium is then evaporated through this window to convert the exposed p-type nanotube transistor into an n-type nanotube transistor, while the other nanotube transistor remains p-type. Reuters "STAR TREK" SHIELDS FOR SUPERTANKS Scientists are developing super-tanks which would use powerful magnets to melt and destroy incoming missiles and shells. Each vehicle would be covered in `smart armour' using electrical fields, instead of thick metal, to give protection against anti-tank weapons. The technology, which is being perfected by defence researchers on both sides of the Atlantic, would transform armoured-vehicle construction. Current machines, such as Britain's Challenger tank, weigh more than 60 tonnes because they have to carry plating that is more than 2ft thick. Such vehicles require massive amounts of fuel and other supplies, and cause logistical headaches when being transported to conflict zones, say military experts. But a tank that relied on electromagnetic pulses, instead of plating, to provide a shield against missiles would weigh a modest 20 tonnes. A fleet would form a light but powerful rapid deployment force, and would transform Western nations' ability to take international military action. Smart-armour research is treated as highly confidential by military officials and manufacturers. A Ministry of Defence spokesman would only confirm that projects aimed at transforming tank construction - part of the Army's Future Land Command project - were taking place. `Developing technologies that will cut back on armour weight are a key part of that research,' he added. However, scientists at the US Army Research Laboratory in Aberdeen, Maryland, have now revealed details of how smart armour would work. According to research published in the current issue of New Scientist magazine, each tank would be covered with tiles made of strong plastic under which a sandwich of different materials would be installed. First there would be a mat of optical fibres, then a thin sheet of standard armour plating, and underneath that would lie a series of metal coils. When an anti-tank shell explodes on standard
armour, the copper cone of its head is projected as a powerful jet of metal
that travels at five miles a second. This jet focuses an immense amount of
energy on a tiny area and so can slice easily through several feet of dense
metal, causing devastation inside a tank. Guardian |
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SCIENCE
QUIZ 1. This US engineer is called "Newton of information science" because he developed in the first half of the 20th century a variety of electronic gadgets like a computer which could play chess and an electronic mouse which could find its way in difficult situations. Can you name this scientist? 2. Some infants suffer from a rare disease called SIDS, due to which a child just dies peacefully during sleep. What is the full name of SIDS, the cause of which is still a mystery? 3. How many species of spiders are there in the world? How many species are found in India? The "silk" secreted by the spiders to build their webs is used by some people for medicinal purposes. What is the main constituent of the "silk" material? 4. What is common between "Iracus", "Hermes", "Eros" and "Ceres"? 5. To reduce pollution, public transport vehicles like buses and three-wheelers in Delhi are being run on CNG under an order of the Supreme Court of India. What is the complete name of CNG? Which gases does it contain? 6. Although used in small amounts in our diet, excessive intake of this ingredient can contribute to high blood pressure or hypertension, osteroporosis, asthma, kidney problems and even stomach cancer. Which is this ingredient? 7. Found in the sea near France, Spain, Italy, Tunisia, etc, this dark-green seaweed clones itself, grows as much as an inch a day and overpowers the local flora. Though safe for human beings, it is toxic to fish that eat it. The French call it "killer algae" and the Italians have nicknamed it "agla assesna". What is the technical name of this plant? 8. In this clinical speciality, ionising radiation is used for treating various cancers. It can be used before surgery, during surgery, after surgery or on its own as a single treatment. Which therapy are we talking about, that represents an intimate relationship between physics and medical science? 9. Mushrooms contain fairly good amounts of vitamin C and vitamins of B complex group. They also contain valuable minerals and salts like calcium, phosphorus and iron. Which other ingredient do mushrooms have in high content because of which they are called meal for vegetarian? 10. This wetland near Kapurthala in Punjab is a home to local birds like hoopoes, orieles, weaverbirds and sparrows and migratory birds like brahminy ducks, pintails and mallards. But the wetlands is losing its charm for tourists due to slush and weeds in it and its poor upkeep. What is the name of this wetland? Answers |
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Significantly,
the former superman actor Christopher Reeve, paralysed after a 1985
horseback riding accident had urged President Bush to ignore Pope John
Paul II and lend federal support for stem cell research. For long,
stem cell research in the USA had remained controversial because it
involved the extraction of embryonic stem cells from embryos or the
retrieval of aborted foetuses.