Genetic research is vital

Dr Steven Cutts examines one of the greatest-ever achievements of medical science in identifying the myriad DNA elements that ensure our extraordinary individuality

IN 2003 an international team of experts completed a multibillion-dollar 13-year project to identify and store the sequences of all three billion chemical base pairs that make up human DNA. Remarkably for such an expensive research study, virtually all the information gained has been made freely available on the internet. The completion of the Human Genome Project coincided with the 50th anniversary of the discovery of the structure of the DNA molecule by Watson and Crick.

A genome describes all the hereditary material in the chromosomes of a particular organism. DNA is the familiar abbreviation for the deoxyribonucleic acid that is the chief component of the chromosomes which replicate themselves and transmit genes from parents to offspring. Human DNA contains 20-25,000 genes.

Understanding what the gene sequences mean and how they interact is the subject of further study — not helped by the belief that over 95 per cent of DNA is thought to be junk — strands that litter the genome turning up between the real genetic material seemingly at random. Yet a single gene defect can be crippling — such as achondroplasia, dwarfism — or even life-destroying like the potentially lethal lung abnormality cystic fibrosis.

Genetic science has implications that go far beyond mere academic science. Long before the structure of the gene was even dreamt of, the Austrian monk Gregor Mendel noted specific patterns of inheritance when breeding plants in a monastery garden. His distractions caused much irritation among his fellow monks and Mendel became the first, though not the last man to annoy the authorities with his study of genetics. Such research has always had a tendency to become intertwined with the broader political philosophies of its time for genetics is inevitably linked to race and breeding.

Bad name

Breeding was considered far more significant in the past than it is today, perhaps, because the breeding of animals was an everyday fact of life. In the early years of the 20th century the Western world was rigidly stratified according to class. Even before Mendel it had been assumed that most if not all a person’s build and character stemmed from ancestry. When the inheritance of specific traits became recognised by science, supporters of inheritance cited it to justify the social and economic status quo. Then in the 1930s the Nazis leant heavily on the anthropological science of the day attempting to justify their concept of Aryan supremacy with the implication that the Teutonic peoples were destined to conquer others. Their distorted philosophy gave geneticists a bad name.

Other extremists regimes added to the discredit. For many years the Soviet Union restricted genetic research and discouraged the teaching of Mendelian inheritance because the Communist Party was staunchly opposed to the ideas of class, inherited wealth and status. In the 1960s the nature-versus-nurture debate gained ground in Western liberal university campuses with one faction denying that genetics could have any bearing on our lives while others propounded the theory that inherited characteristics solely determined one’s role and status in life. Both factions hoped for scientific discoveries that would give credence to their political beliefs. This was a mistake. Hijacking science to try justifying political systems will always end in tears.

The triumphs of genome research have reawakened expectation that science will offer new insights into why individual human beings are so much alike and yet so very different. Already we have learned that the proportion of DNA varying between individuals and races — event between mice and men — extremely small. Animal rights activists have already seized on the knowledge to persuade us to sympathise with laboratory rats.

Knowing how our genes define our makeup will enable future therapy for diseases previously considered untreatable. Conditions such as cystic fibrosis and sickle-cell anemia may be eliminated by manipulation of the genome and future generations may perceive present reticence to begin the process as incomprehensible. How could it harm society by eliminating such afflictions as Alzheimer’s disease, breast and bowel cancer?

Past extremists gave genetics a bad name. Now medical scientists have a golden opportunity to give it the good one it deserves. — AF

Building tips

MAKE a schedule of various lengths of steel required for RCC in slabs, beams, columns and lintels. Some lengths are straight and others cranked. Find straight length of each type of bar. Assign a code number to each bar and find the required numbers for each code. Thus a bar cutting and bending schedule is ready. Make calculations to work out required steel lengths for each diameter. Bars available in the market vary in length from 9 to 12 metres. Choose the lengths required by you. This exercise will minimise the wastage of steel and you will not be left with many cut pieces. Ask bar binder to first cut bars to required lengths and then give required shape to each kind of bars.

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Whatever cut pieces get generated during cutting of steel, convert them into chairs and spacers. Do not insert these cut pieces here and there in the slab as most masons do by saying that it will further strengthen the slab. Such cut pieces provide no additional strength. Make Z type chairs and spacers of them and tie them at regular intervals below the top steel to avoid its sagging during laying of concrete when labour walks over it.

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There are many cranked bars in beams and slabs which are bent as per drawing by the blacksmith and stacked aside. While placing these bars in position, it has been seen that sometimes the bars get placed in upside down position. This is a dangerous situation and such beams or slabs may collapse any time. A simple check for correctly placed steel is that the cranked bars of slab should be above the walls while straight lengths at the centres of rooms. Similarly, cranked bars of beams should be at ends and straight lengths at the centre of beams. Prefer to get the steel checked from a qualified engineer before pouring concrete in position.

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Use soft iron binding wire for binding of steel in position. Soft iron wire does not break up during its bending around the bars. Choose 16 or 18 gauge wire. Ensure that it is rust free. Mostly it is available in bundles of small pieces each having sufficient length to tie two bars. While binding the steel, ensure that the loose ends of binding wire are turned down into the slab and these do not protrude above the bars. If this is not done, these small wires will come out of slab surface and pave way for rusting of steel. This small precaution pays dividends in the long run.

— Jagvir Goyal

THIS UNIVERSE
PROF YASH PAL

Q Why do light bulbs immediately begin to glow as the current is turned on, and tubelights require a few seconds?

A The filament in the light bulb is made of a high resistance wire. The heat capacity of this wire is low. Therefore, it is quickly raised to a temperature high enough to balance the energy emitted as light and heat and that produced through Ohmic loss by the current flowing through the filament. That is why the light bulb begins to glow quickly.

When you switch on a tubelight, the current cannot pass unless a plasma discharge is started by delivering a high voltage pulse. You would remember that the starters of ordinary tubelights contain ballast and a condenser. The ballast is essentially a high impedance choke. The condenser reduces the electromagnetic interference. The heating of the electrodes at both ends of the tube leads to emission of electrons, which are the initial carriers of the current for the discharge. The current for heating the electrodes is cut off after the discharge begins, because the electrode temperature is then kept high by the impinging ions. The high voltage to initiate the discharge is produced by interrupting the current in the ballast. The initial heating time of the electrodes and building in the required sequencing takes a little time. This is the reason why ordinary tubelights require a few moments before they begin emitting light.

Q Is it true that exposure to ultrasonic frequencies can make seeds germinate faster?

A My answer is that I do not know the answer. I have scanned the Net and could not find anything definitive. If you come across some reliable information in this regard, I would like to hear about it. One will have to define the strength and frequency of the ultrasound. If the signal is too strong, one could smash the seed. I suspect germination is a biochemical process and I do not know how such processes could be speeded up by ultrasonic bombardment. But as I said earlier, I really do not know the answer.

Q As per Vastushastra we should sleep with our head towards the south and legs towards the north. Is their any scientific base for this?

A I really do not know, but I doubt it. Some one might have derived a statistically significant effect of disregarding this instruction. I have not seen it, nor can I think of a deep physical basis for this assertion. All I can say is that I have lived long enough a life completely unaware of this advice and none the worse for it.

Q Is there such a thing as anti-gravity?

A My first answer to this would be in the negative. Anti-gravity is science fiction. However, I must be a little cautious, because some descriptions of the very early evolution of the universe suggest that it might have inflated very fast for a tiny instant soon after its creation (or the “Big Bang”). But to think of this as due to antigravity might be premature or simplistic. Outside of this, I do not think it would be possible to invent an antigravity machine!

New Products and Discoveries

Andromeda is huge

At the annual summer meeting of the American Astronomical Society today, Chapman outlined the evidence that there is a vast, extended stellar disk that makes the galaxy more than 220,000 light-years in diameter. Previously, astronomers looking at the visible evidence thought Andromeda was about 70,000 to 80,000 light-years across. Andromeda itself is about two million light-years from Earth.

Imitation sounds

Elephants learn to imitate sounds that are not typical of their species, the first known example after humans of vocal learning in a non-primate terrestrial mammal. The discovery, reported in Nature, further supports the idea that vocal learning is important for maintaining individual social relationships among animals that separate and reunite over time, like dolphins and whales, some birds, and bats.

Researchers from the Amboseli Trust for Elephants in Kenya, the Woods Hole Oceanographic Institution and the University of Vienna studied sounds made by two African elephants, one living among semi-captive orphaned elephants and the other with two Asian elephants in a zoo. One imitated truck noises heard from a nearby highway, the other the chirps of another elephant species.

Founding  families

A geneticist armed with computer simulations of prehistoric populations says that only about 200 to 300 people crossed the ice age land bridge from Asia to become the founding population of North America. Of that pioneering group, there were just 70 adults of reproductive age, contends Jody Hey of Rutgers University in Piscataway, N.J.

Hey arrived at that strikingly small number after analysing DNA from living Asians and Native Americans. Using nine specific DNA sequences as reference points, he inferred the movements and characteristics of the ancient population, including the Americas’ founding fathers and mothers.

“It looks like a group that was about the size of a single tribe made the initial trip from Asia to the New World,” Hey says.