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Archive for October, 2006

Quantum Physics Experiments

Posted by iKnowHOW on October 31, 2006

Shows how mater fluctuates in properties from particles to waves just because of the way its observed!

Double Slit Experiment

Flatland

In an alternative, yet equally mind blowing study:

Quantum physics has already shown the influence of human thoughts on the character of the experiment. Wow! They have proven that scientists in this study who believed in a given experiment, had successful results, while the scientists who doubted, had unsuccessful results. Now check this out, the movement of electrons in atoms was steered by the mental attitude of the experimenters. The electrons circulated differently for those who believed and oppositely for those who didn’t believe. As a result, something like 10 scientists confirmed that what they were experimenting with was true, while 12 others confirmed that it was false. And both answers had solid, scientific proof!!!

Particle physics is based on very concrete experiments, prepared with great precision. There’s no room for assumptions. The movement of electrons and all those spirals were measured under a very high definition microscope, and the results revealed both yes & no. Finally someone clued in to the blatant correlation staring them in the face – that the experimenters who believed what they were going to prove is true, those electrons circulated in specific spirals, while those experimenters who thought that its not true, their electrons circulated in opposite spirals!! Thus changing the results of the research.

Thoughts influence mater. That’s the latest evidence from particle physics. Human thoughts control the movement of electrons in atoms. Woo hoo! As they’ve told us before, we are not just observers but also participants. We contribute to making our reality, and whatever we believe, life proves it to us.

No thought is unnoticed by the universe. And a group of people collectively thinking about one subject in a certain way, is very powerful. Imagine – if enough people think that a certain politician is stupid, we are actually contributing to making him dumber.

by fluidspirit

Posted in Quantum Physics, Universe, Video | 4 Comments »

More than four dimensions

Posted by iKnowHOW on October 31, 2006

The list of dimensions doesn’t run out with time, says Lisa Randall

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Scientific progress always entails an almost contradictory set of beliefs. You need to make assumptions to build a mathematical picture of reality. But while you want to be sufficiently excited about your assumptions to think they merit investigation, you need to remain sceptical enough to subject the consequences of those premises to rigorous analysis.

Although I’ve always combined these attitudes in my research, my recent studies of extra dimensions of space, beyond the familiar “up-down”, “left-right” and “forward-backward” have made me more than usually convinced that they must really exist.

Perhaps the best way to understand what these extra dimensions would be is the way Edwin Abbott described them in his book Flatland, written in the late 19th century. Suppose there was a society that, unlike ours, could detect and experience a world with only two dimensions: the Flatland of the title. Its inhabitants wouldn’t perceive a third dimension, even though the dimension really did exist.

If an object like a sphere were to pass through their universe, Flatlanders would never perceive it in its entirety; instead, they would see a succession of disks that grew in size and then became smaller. Because they register only two dimensions, Flatlanders could only mathematically piece together the fact that the object they had seen was the analogue of their disk, but in one higher dimension.

Similarly, the fact that we see only three dimensions doesn’t mean there might not be more. Einstein’s theory of general relativity doesn’t stipulate any particular number of dimensions. And from the perspective of his theory of gravity, there’s nothing special about three dimensions of space. People have often made the mistake of believing only in what they could see. Extra dimensions might turn out to be one among many aspects of the cosmos about which we were initially mistaken.

The string theory is another reason to believe extra dimensions might exist. It consistently incorporates our theories of the very small and the very big in the Universe ? quantum mechanics and general relativity ? which no earlier theory had accomplished. This doesn’t prove the string theory is right, and it’s critical that we do further research. Because it promises to be a more comprehensive theory than any other we know of, a so-called theory of quantum gravity, the string theory is well worth studying.

However, it doesn’t naturally describe a world with three dimensions of space. It more naturally suggests a world with many more, perhaps nine or 10. A string theorist doesn’t ask whether extra dimensions exist; instead, two critical questions that a string theorist asks are: where are they and why haven’t we seen them?

Even if you’re sceptical about the string theory, recent research has provided perhaps the most compelling argument for extra dimensions: a universe with these dimensions might contain answers to physics puzzles that have no convincing solutions without them. That alone makes extra dimensions worthy of investigation.

The history of physics is the story of discovering different, more basic elements of matter as we’ve developed the tools to explore different length and energy scales. Once scientists could observe matter on smaller scales, they discovered atoms and quarks, and after they could study further distances in the Universe, physicists and astronomers discovered galaxies and dark matter.

Extra dimensions might be hidden (for now) but none the less be part of reality. More detailed observations at higher energies and shorter distances might eventually reveal their existence.

These as-yet-unseen dimensions could be flat, like the dimensions we are accustomed to. Or they could be warped, like reflections in a fun-house mirror. They might be tiny, far smaller than an atom, or they might be big, or even infinite in size, yet still be hard to see.

Brilliant mind: Lisa Randall ; (below) the cover of her book

Our senses register only three large dimensions, so an infinite extra dimension might sound incredible. But an infinite unseen dimension and parallel universes within it are some of the bizarre possibilities for what might exist in our cosmos.

To see why extra dimensions are not ruled out by our apparently three-dimensional observations, we need to understand how dimensions can exist, but be invisible. In 1920, almost immediately after Einstein completed his theory of general relativity, Theodor Kaluza suggested an extra dimension of space, and in 1926, Oskar Klein proposed a reason why we wouldn’t see it.

An extra dimension could be rolled up into such a tiny size that it would have no visible effects. If you think of extra dimensions rolled up like a garden hose, the width of the “hose” could be so tiny that we’d never notice it. Any variations over this tiny distance would be washed out, much as the atomic structure of this piece of paper is imperceptible.

But although physicists have known for years that extra dimensions could be rolled up, it wasn’t until 1999 that Raman Sundrum (who was then a post-doctoral fellow at the Boston University) and I (then a professor at MIT) discovered another reason that extra dimensions might be hidden.

Einstein’s theory of relativity tells us that energy and matter curve space and time. We found that spacetime with extra dimensions could be so extremely warped that even an infinite extra dimension could exist but escape detection.

The success with which our theory mimics three dimensions suggests that all evidence that apparently points to three dimensions of space supports the idea of such “warped” extra-dimensional universes equally strongly. None the less, our idea was so different from older notions that it took a while for some physicists to accept. Fortunately for us, however, Stephen Hawking and a few others immediately appreciated its radical implications.

The following year another physicist, Andreas Karch, and I found that space can be even more spectacular: the Universe can appear to have three spatial dimensions in some regions but appear to have, or in fact have, more (or fewer) in others. Our notion of three-dimensional “sinkholes” extended the Copernican revolution beyond anything we had imagined.

Not only is the earth not the centre of the Universe, but our domain might be a tiny isolated pocket with three spatial dimensions inside a universe that harbours many more. This was a huge revelation, one that convinced me we have a lot more to understand about extra dimensions of space, and one that also made the idea of extra dimensions more credible; isn’t it presumptuous to rule out something whose implications we don’t even fully comprehend?

But perhaps the most convincing reason to believe in extra dimensions is that they permit new connections among properties of the observed Universe and have a real possibility for explaining some of its more mysterious features. Extra dimensions can have implications for the world we see and explain phenomena that seem incomprehensible when viewed from the perspective of a three-spatial-dimensional observer (or theorist).

We wouldn’t understand the shapes of the continents unless we add the dimension of time and recognise how they were once connected together in a supercontinent. Similarly, some problems in physics are more readily understood with extra dimensions of space.

Chief among these questions is why the gravitational force is so weak. Gravity might not appear to be all that weak when you’re hiking up a mountain, but bear in mind that the gravitational force of the entire earth is acting on you. Think how feeble gravity must be for you to counter the force of the much larger earth when you pick up a ball.

In fact, if the earth were your size, gravity wouldn’t be noticeable at all. For more than 30 years, physicists (including myself) have explored this conundrum, and they’ve found no completely compelling solution.

But with an additional warped dimension, it’s natural for gravity to be weak in our vicinity. In our warped spacetime geometry, gravity is very strong in one region of a fourth dimension of space (a fifth dimension of spacetime) but very weak everywhere else.

For me, the explanation for the weakness of gravity is sufficient reason in itself to take the possibility of extra dimensions seriously. The mystery is the biggest gaping hole in our understanding of the physics of elementary particles, and an extra dimension provides an answer. As a scientist, even if I believe that extra dimensions exist in nature, I don’t have blind faith and I’m willing to be proved wrong. We don’t yet know how to experimentally test all extra-dimensional theories. But the fabulous thing is that if the theory I just told you about ? the one that explains the weakness of gravity ? is correct, we will see experimental evidence within the next five years. These tests that high-energy experimenters will perform are critical to confirming (or ruling out) our ideas.

The evidence will take the form of Kaluza-Klein particles, which are 1,000 times smaller than the proton and travel in extra dimensions, but would register in experiments as extra-heavy particles in what appears to be a three-spatial-dimensional world.

If warped extra dimensions explain the weakness of gravity, the Large Hadron Collider that will begin operation at CERN in Geneva in two years will have enough energy to make such particles (you need lots of energy to make heavy particles, as we know from Einstein’s most famous equation, E=mc2 ). If experimenters discover them, my belief in extra dimensions will be proved justified.

Those of us who no longer straitjacket ourselves to theories with only three dimensions of space have found amazing consequences of Einstein’s equations that had escaped physicists for years. The range of possibilities for what might lie in the cosmos is remarkable, and we’re still only beginning to understand them all. I’m fairly confident new dimensions are out there and it’s more a question of if and when we’ll find them.Given how much extra dimensions ? or whatever we discover ? will tell us about the fundamental nature of our Universe, do we have any choice but to explore?

(The author is a professor of theoretical physics at Harvard University. Her new book, Warped Passages, has just been released.)

The Daily Telegraph

Posted in Dimension, Physics, Universe | 2 Comments »

From here to eternity

Posted by iKnowHOW on October 31, 2006

The Universe will die. But maybe, life won?t, says Michio Kaku

The great 19th-century biologist Thomas Huxley once wrote that the ?question of all questions for humanity… is that of the determination of man?s place in Nature and his relation to the Cosmos?. We might soon be able to provide the answer to this huge riddle as a battery of instruments ? including satellites, gravity-wave detectors and laser devices ? not only begins to give us startling insights into our place in the cosmos, but also forces us to confront the birth and final death of the Universe ? and even the possible existence of parallel Universes.

In the next decade, powerful new satellites will find evidence of earth-like twins orbiting other stars.

So far, our instruments are so crude that we can only detect about 130 giant, Jupiter-sized planets, which are probably devoid of life. In 2006, the Kepler satellite will be launched with a mission to analyse 100,000 stars for large planets.

But in 2014, the Terrestrial Planet Finder will begin to hunt for small, earth-like planets in 500 star systems with a telescope designed to screen out the mother stars, whose light otherwise overwhelms the faint radiation from any nearby planets.

If these efforts pay off, people will have an existential shock, knowing that, when gazing at these twins in the night sky, there might be someone looking back. The thought of detecting intelligence in the Universe is exhilarating to most scientists. However, as science fiction writer Arthur C. Clarke once cautioned: “There may be intelligent life in space or not. Either thought is frightening.”

Cosmology, our understanding of the Universe, might be revolutionised when the Lisa (Laser Interferometry Space Antenna) is launched in 2011. It will orbit the sun at the same distance as the earth, but trailing us by 30 million miles. Consisting of three satellites linked by laser beams, it will form a huge triangle of laser light about three million miles on each side. If a gravity wave from space hits this triangle, it will cause a tiny distortion in the laser beams, which will be detectable by its instruments. (Lisa will detect optical distortions one hundredth the size of an atom.)

Lisa should be able to detect cosmic explosions nine billion light-years from earth, which cut across much of the visible Universe, as well as colliding black holes and even the shock waves emitted a trillionth of a second after the Big Bang, which are still circulating around the Universe. Hence it may be capable of resolving the most perplexing and stubborn question facing cosmology: what happened before the instant of Genesis?

Second universe: Michio Kaku at a bookstore in New York

In the various pre-Big Bang theories that have been proposed, each predicts a different type of shock wave of gravity emitted once the explosion takes place. Lisa, by analysing the precise frequencies and wave-like patterns of the gravity waves emitted at the instant of the Big Bang, should be able to distinguish between them and prove or disprove the theories.

So far, the leading theory is called “inflation” and postulates an unbelievably fast, turbo-charged expansion of the early Universe after the Big Bang of creation. However, if the inflation process happened once, it can happen again. The latest version of this is called “chaotic inflation”, in which Big Bangs can happen randomly. Like soap bubbles that split and sprout other soap bubbles, Universes can bud and create new “baby Universes”. In this picture, Big Bangs are happening all the time, even as you read this article.

But to understand what caused inflation, physicists have to reach for a theory that can incorporate both gravity and all known forms of radiation — the so-called “theory of everything”.

The only candidate for this is called string theory, or M-theory, in which Universes can float in 11-dimensional hyperspace in a “multiverse” of Universes.

Imagine two parallel sheets of paper; ants on one sheet will be invisible to ants on the other, yet they are separated by a few inches. Similarly, if a parallel Universe hovered a millimetre from ours in another dimension, it would be invisible.

As fantastic as these theories are, Lisa may be able to prove or disprove them because each of them leaves behind a different “fingerprint”, or pattern of gravity waves, when the Big Bang occurs.

Ominously, satellites are also giving us a glimpse into the ultimate fate of the Universe. Philosophers have wondered if the Universe will die in fire or ice. The data overwhelmingly favour the Big Freeze rather than a Big Crunch.

The Universe, in fact, is not slowing down, but accelerating, careening out of control in runaway mode. A mysterious form of energy, dubbed “dark energy”, is acting like an anti-gravity force that is pushing the galaxies apart, causing the Universe to accelerate uncontrollably and eventually blowing it apart. In the distant future, billions to trillions of years from now, the stars will exhaust their nuclear fuel, the oceans will freeze, the Universe will turn dark and temperatures will plunge to almost zero. It appears inevitable that all intelligent life will perish when the Universe itself freezes over.

This possibility of “unyielding despair” was explored by the mathematician Bertrand Russell, who wrote, in one of the most depressing passages in the English language, that “no fire, no heroism, no intensity of thought or feeling, can preserve a life beyond the grave… all the labours of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system; and the whole temple of Man’s achievement must inevitably be buried beneath the debris of a Universe in ruins…”

Today, we believe that space arks may one day preserve life after the death of the sun in five billion years. But can you build a space ark to escape the death of the Universe itself?

The only possible way to avoid the death of the Universe is to leave. Perhaps civilisations billions of years ahead of ours will harness enough energy to punch a hole in space and escape, in a hyper-dimensional space ark, to a new Universe.

Although it seems far-fetched, even preposterous, physicists have seriously considered this possibility using the known laws of physics. Einstein’s equations, for example, allow for the possibility of “Einstein-Rosen bridges” connecting two parallel Universes. (Imagine two horizontal parallel sheets of paper connected by a thin vertical tube.) The energy necessary to create such a “wormhole” connecting two Universes is truly immense — the Planck energy, or 1019 billion electron volts (a quadrillion times the energy of our largest atom smasher).

In desperation, an advanced civilisation may create huge banks of laser beams and atom smashers to create the unbelievably intense temperatures, energy and densities necessary to open up holes in space and leave the Universe.

Calculations show that these gigantic machines must be the size of star systems, but this may be possible for civilisations billions of years ahead of ours. Unfortunately, some preliminary calculations show that the wormhole may only be microscopic in size. If so, an advanced civilisation may resort to shooting molecular-sized robots, called “nanobots”, through the wormhole. Once on the other side, these nanobots will then create huge DNA factories to grow clones and replicas of their creators. Since they will contain the entire database of their civilisation, they will use this to resurrect it in another Universe.

Although the physical bodies of these individuals will die when the Universe freezes over, their genetic twins will live on, so that their civilisation, like a Phoenix, may flourish again. As incredible as these scenarios are, they are consistent with the known laws of physics and biology.

So, when contemplating the question raised by Huxley in 1863, our true role in the Universe may be to spread the precious germ of intelligent life throughout it and, one day, to spread the seed of life by leaving a dying Universe for a warmer one.

(The author is a professor of theoretical physics at the City University of New York)
The Daily Telegraph

Posted in Universe | 1 Comment »

Rigged in favour of life

Posted by iKnowHOW on October 31, 2006

The universe seems to be “just right” for life.

Albert Einstein is famous for remarking that what most interested him was whether God had any choice in the nature of his creation. By this, Einstein was asking in characteristically quaint language whether the universe could have been otherwise. Two generations later, Einstein’s rhetorical question has resurfaced with a vengeance, and sparked a controversy that has split the physics community.

At the heart of the row lies the deep problem of the laws of physics: where do they come from and why do they have the form that they do? These are not questions that scientists normally ask. But they have been thrown into this by the work of a band of theorists struggling to merge all known laws into a unified mathematical scheme.

A fashionable contender is string theory, which replaces the notion of a world built from particles with the claim that little loops of writhing string can explain everything from electrons to the force of gravity. It’s a compelling idea that has attracted the world’s top brains, but has yet to convince sceptics. Meanwhile, dramatic progress in cosmology has enabled astronomers to piece together the story of the universe back to the first split seconds after the Big Bang.

Given these sweeping advances, it isn’t surprising that some scientists are tempted to move beyond technicalities and tackle the big foundational questions: how the universe came into being, and why its laws are mathematical in nature. One question above all has received a lot of attention. Scientists have long known that the existence of life depends rather delicately on a number of felicitous coincidences and special factors in fundamental physics and cosmology. Like Baby Bear’s porridge in the story of Goldilocks, the universe seems to be “just right” for life.

Getting it right

Imagine playing God. In front of you is a machine complete with a row of knobs. Twiddle this knob and you make all electrons a bit heavier; twiddle that knob and you slightly strengthen the force that binds protons and neutrons in atomic nuclei. According to the standard models of particle physics and cosmology, there are thirty-something such adjustable quantities needed to describe the physical world.

Simple calculations then suggest that meddling with some of the knob settings, even by a tiny amount, would prove lethal, wrecking any hope that life could emerge in the universe. If protons were just a tad heavier, all else being equal, they would decay into neutrons, and atoms would fall apart. If the nuclear force were a few per cent different then carbon, the life-giving element, would never have formed in abundance by nuclear reactions inside stars. In each case, life would be impossible. Taking into account many such “fine-tunings” in physics and cosmology, it looks as if the universe is a fix — a big fix.

This is where the knives come out. Some cosmologists, most notably Lord Rees, president of The Royal Society, believe there is a very natural explanation for the uncanny bio-friendliness of the universe.

What we have all along been calling “the universe” is, it seems, nothing of the sort. Rather, it is but an infinitesimal fragment of a vast and elaborate system of many universes, or distinct cosmic regions, collectively dubbed “the multiverse”.

Crucially, claims Rees, the laws of physics we observe in our universe are not the same everywhere but are more akin to local by-laws. Other universes within the multiverse will have different laws. Thus a universe over there may be expanding faster than ours and contain electrons with stronger charges, while in the universe next door gravity may be a bit weaker or protons a bit heavier.

These cosmic-scale variations might be completely random. The occasional universe would then fall in the “Goldilocks zone” like a winner in a cosmic jackpot, and possess by pure chance laws and properties just right for life. It would then be no surprise that we perceive a universe so weirdly suited to our own presence.

The multiverse idea isn’t just idle speculation, but is bolstered by discoveries in subatomic particle physics. As the energy of physical processes is raised, in particle collisions, so the laws describing the particles’ behaviour tend to become simpler and mesh neatly together. The greatest particle physics experiment in history was the Big Bang that gave birth to the universe 13.7 billion years ago, so it makes sense to expect the universe to have started out with simple laws.

Then, as the universe expanded and cooled, so the effective, relatively low-energy “by-laws” we observe in the lab emerged from the fiery maelstrom. If there are many alternative low-energy laws, as theory suggests, then it is likely that a sort of cosmic patchwork quilt arose, in which each patch acquired its distinctive set of laws. Our universe is buried deep in such a patch.

Sceptics speak

If all this seems hard to swallow, some particle physicists — especially string theorists such as Nobel prizewinner David Gross of the University of California at Santa Barbara — will heartily agree with you. They have slammed the multiverse explanation of the Goldilocks enigma, calling it sloppy science and quasi-religious mumbo-jumbo.

The holy grail of particle physics is to produce a final theory of everything. It will nail down completely every aspect of physical law: all particle masses, the strength of every force, the details of the Big Bang — each will be precisely determined in a welter of breathtaking mathematics.

According to this ambitious vision, God would have no choice in the matter (to paraphrase Einstein), because the laws of physics would be uniquely specified by the theory, with no lassitude to vary from one universe to the next. The fact that this unique set of laws just happens to permit life would be shrugged aside as an incidental quirk of no significance.

The multiverse proponents have hit back, in turn accusing the string theorists of promissory triumphalism. So far, string theory, or for that matter any other contender for a final theory of everything, has yet to predict correctly a single particle mass or force strength.

Some cynics have denounced putative theories of everything as in reality theories of nothing. Amid this acrimonious bickering, it is worth asking whether there might be another explanation for why the universe appears to have been ingeniously rigged in favour of life.

Posted in Universe | Leave a Comment »

Does good hygiene beget bad health?

Posted by iKnowHOW on October 30, 2006

Genetically tinkered parasitic worms actually have the potential to lower the incidence of autoimmune diseases, writes P.K. Sumodan

Catch-22: Unhygienic living conditions play an important role in strengthening immunity

It all started with a group of genetically-modified mice with a predisposition to Type 1 diabetes that Professor Anne Cooke of Cambridge University, UK, and her colleagues were researching on. Once, some of the mice, while being transported from London, caught bacterial and parasitic infections. This led to an unexpected result — only 50 per cent of the rodents developed diabetes instead of the expected 80 per cent.

Prof. Cooke immediately sensed a correlation between the two incidents. To test the hypothesis, she and her team infected the genetically modified mice with a parasitic worm called schistosome, which causes schistosomiasis (snail fever), a disease found in parts of Africa, Asia and South America. The scientists found the infection reduced the incidence of diabetes.

In fact, when the mice were infected early in life, none of them went on to develop Type 1 diabetes. Further research showed it was some component of the egg rather than the later stages of the parasite’s development that protected the mice from diabetes.

However, in European countries, where schistosomiasis is non-existent, there has been an increase in the occurrence of autoimmune diseases such as Type 1 diabetes, rheumatoid arthritis, Crohn’s disease (also called regional enteritis characterised by diarrhoea, cramps and loss of appetite) and so on.

Autoimmunity is an abnormal function of our immune system, where antibodies are produced against one’s own cells. In Type 1 diabetes, for instance, pancreatic cells are destroyed by the immune system so that the production of insulin is curtailed.

Interestingly, even though schistosomiasis is absent in many Asian countries including India, these nations do not have a very high incidence of autoimmune diseases. The reason, experts say, could be the prevalence of intestinal bacteria and parasitic worms such as hookworm, pinworm, filarial worm and round worm in these countries. According to Prof. B.S. Ramakrishna of the department of gastrointestinal sciences, Christian Medical College, Vellore, intestinal infection with Helecobacter pylori — a bacteria causing certain ulcers — could be the reason for the low incidence of autoimmune diseases in India.

Hygiene hypothesis

In an article titled “Parasitic worms and inflammatory diseases” in the journal Parasite Immunology (October 2006), Professor Cooke and her colleagues discuss the emerging evidences favouring the “Hygiene hypothesis”, which states that better hygiene and lack of parasites are related to the high incidence of autoimmune diseases.

The researchers say that early human civilisations were exposed to a host of pathogens because of unhygienic living conditions, unclean drinking water, improper sanitation and so on. In due course, the immune system adapted itself to these pathogens and the accompanying parasites and bacteria. In other words, parasites and microbes have played an important part in strengthening one’s immunity.

Most autoimmune diseases are genetic disorders. How, then, does aschistosomal infection help? Studies conducted on twins having the same genes but living in different environments showed that environment played a key role in the expression of the genes. It was found that in hygienic environments, the immunological responses triggered by the immune system were diverted to a different target. In the event of aschistosomal attack, the immune system, instead of targeting the pancreatic cells (that lead to Type 1 diabetes), attacks the infection. This mechanism explains the role of infections in reducing autoimmune disorders.

Worms for health

So what would we prefer: autoimmune diseases or diseases caused by parasitic worms? Since autoimmune diseases are genetic disorders, curing them completely requires gene therapy, a costly and less successful process. On the other hand, parasitic worms can be effectively managed with cheap medication.

However, unhygienic conditions could lead to more serious problems such as cholera. A better option would be to take cues from the “Hygiene hypothesis” and develop better strategies to combat autoimmune diseases.

We may use genetically modified worms, which can elicit the required immune responses from our immune system without triggering any harmful effects. A better option would be to develop a drug based on the chemicals present in the worms that stimulate immune response. It will be interesting to see a reversal in worm related practice, a change from de-worming to artificial worming!

(The author is a lecturer of zoology at a Kerala government college.)

Posted in KnowHOW Health | 1 Comment »

Nuclear dating for antics

Posted by iKnowHOW on October 30, 2006

An adjunct programme of the International Atomic Energy Agency fosters the use of nuclear methods to address historic and artistic riddles like verifying the origin and authenticity of art objects. William J. Broad reports

(From top) A Tang dynasty figurine, Statue of Mars of Todi, a Corinthian vase

Eager for precision in a field notorious for ambiguity and frustration, curators at top museums in Europe and the US have long reached for the instruments of nuclear science to hit treasures of art with invisible rays. The resulting clues have helped answer vexing questions of provenance, age and authenticity.

Now such insights are going global. The International Atomic Energy Agency (IAEA), best known for fighting the spread of nuclear arms, is working hard to foster such methods in the developing world. This is to make scientists in places like Peru, Ghana and Kazakhstan act as better custodians of their cultural heritage.

Scientific papers and abstracts describe how research projects had used nuclear methods to address historic and artistic riddles. For instance, Chinese scientists had fired the subatomic particles known as neutrons at ancient pottery from the Tang dynasty, which ruled China from AD 618 to 906. The analysis is helping them uncover the art works’ origins in regional workshops.

In an interview, Feng Songlin, a scientist at the Institute of High Energy Physics in Beijing, said he found the agency’s programme “very helpful for Chinese archaeology research and for me”. He said it had helped him ascertain the best analytical methods, prepare samples and learn how to interpret the findings.

Mexican scientists have also applied such methods to colonial-era pottery. Pieces once thought to have been imported from Spain turned out to have been made locally.

The methods used, some of the most fundamental in nuclear science, include neutron activation analysis, proton-induced X-ray emission, accelerator mass spectrometry and X-ray fluorescence spectrometry. The advances are striking because the world of art often finds itself hard pressed to achieve basic goals like verifying the origins of pieces. The standard historical approach of comparing style and iconography, even when coupled with painstaking detective work in archives and distant collections, has often proved inconclusive or at times even deceptive.

The atomic methods, some applied to artistic analysis for the first time in the 1970s and 80s, have revolutionised the field of art history. For instance, the Metropolitan Museum of Art in New York gained a wealth of insights into the provenance of old sculptures in its collection, including some sculptured heads separated from torsos during the French Revolution. The trouble arose when radicals, mistaking statues of religious figures for royalty, developed a taste for decapitation.

The museum’s detective work began at a nuclear reactor, where operators would bombard detached bits of the artwork with speeding neutrons. The resulting showers of gamma rays revealed the presence of trace elements in distinct patterns.

These identifying signatures let museum curators make matches with similarly revealed signatures of European churches, quarries and carvings. For instance, they recently found that one of the sculptured heads in a current exhibition came from a quarry that supplied statuary to either Notre Dame or another 13th century Parisian church.

The Louvre in Paris has a very long accelerator in its basement that fires subatomic particles at artwork to discover compositional clues. Maria Filomena Guerra, a specialist there in ancient gold artefacts, travelled to Vienna last month to help the IAEA with its outreach programme.

The agency is now fostering the development of such techniques in Hungary and other countries. In Budapest, scientists are using a cousin of the neutron technique to study Stone Age pottery, including a graceful bowl from a cave in the Bukk mountains. The method is known as prompt gamma activation analysis.

The Hungarian scientists are using the gamma method to compare pottery from eight sites with a variety of clay samples in hope of establishing where the pots arose. The trace elements so far identified include vanadium, neodymium, samarium and gadolinium. The scientists plan to expand the number of investigated sites and soils to produce a comprehensive portrait of artistic evolution in Stone Age Hungary.

Dr Matthias Rossbach of IAEA said he had recently administered a kind of proficiency test to the programme’s members. They were sent bits of powdered Chinese porcelain for analysis, and the results were compared with the agency’s findings. “It was,” he said, “like a teacher grading a report. The objective was to help them improve their method.”

At a display, the scientists set up an instrument, a portable X-ray fluorescence spectrometre, a device little bigger than a golf bag. When in operation, its beam of X-rays stimulates material under observation to glow at various wavelengths, allowing the identification of constituent elements.

The method is cheaper, easier and faster than the neutron technique, though slightly less precise. The scientists said the agency had developed the portable device for use in art museums, and they demonstrated how it worked by training it on a piece of painted canvas.

To the naked eye of an observer, admittedly no art expert, the paint looked dull and drab, almost too plain for words. But the X-rays revealed a kaleidoscope of pigment elements, rendered on the computer monitor as a series of wiggly lines. The scientists identified the peaks as sulphur, calcium, titanium, iron and zinc. Such chemical signatures, they said, could help confirm whether the pigment and painting were actually made at an advertised date, because paint formulas often changed over the decades.

Dr Rossbach said the programme excited him because in the process of teaching he discovered so much about global art as well as its diverse ranks of scientific custodians.

“I’ve learned about pottery in China and icons in Poland,” he said. “I know the techniques they’re using and can discuss whether they’re doing it right. So that, I think, is a very good exchange.”

Posted in Physics | 7 Comments »

Vanishing islands Displaced Climate casualties Underlying truth

Posted by iKnowHOW on October 30, 2006

Rising sea levels are playing havoc across the Sundarbans — two islands have already been submerged. More islands are facing the same fate, reports Subhra Priyadarshini

Losing ground:Land area in the Sundarbans islands is shrinking.

They saw the shore pushing in closer every day. Yet, Shamila and her mother never thought the sea would completely devour their tiny island of Lohachara in the Sundarbans. And then one day, it did. The family of four was forced to pack its modest belongings and head for Sagar, the largest island in west Sundarbans. In the late 1990s, more such families followed suit.

“There’s nothing any more where our island once was. It’s just a huge stretch of sea where vessels ply,” says Shamila’s father Seikh Abdullah, among the first batch of envirogees (environment refugees) who have now settled in Sagar. Nearly 7,000 of his former island mates are his neighbours again.

The seas are rising across the Sundarbans, the 100-island conglomerate in the Ganges estuarine delta in the Bay of Bengal. One more island in the vicinity — Suparibhanga (also called Bedford) — has sunk. It had no recorded human population, though.

In Calcutta, Jadavpur University’s School of Oceanographic Studies has gathered a number of glaring climate change indicators in the fragile estuarine ecosystem, home to the famous Royal Bengal tiger. Since 1965, the temperature of the group of islands has risen by over one degree. The number of annual cyclones, which wreak havoc in the small islands, has fallen but they are more intense now. This means more coastal flooding, erosion and more saline water moving in on the islands.

“The sea level rise south of Sagar island could go up to 3.5 mm a year over the next few decades because of global climate change. Sagar itself has lost about 30 km of land by now. The rising seas could wash out almost 15 per cent of the existing 9,000-plus square kilometres of the islands,” says Sugata Hazra, director of the School of Oceanographic Studies.

Mujibullah, who came to Sagar as a teenager and now sustains a family of six on seasonal Hilsa catch, agrees. “Today, I see Sagar’s west end — Boatkhali and Laudhas — gradually being eroded. If Sagar too has a similar problem, we don’t know where to go.” As of now, a friendly Sagar panchayat has given them refuge and livelihood out of empathy, a strong emotion binding islanders across the Sundarbans.

Displaced

Threatened? (Above) The Royal Bengal Tiger and the Barking Deer

The “vanishing islands”, as Hazra calls them, have rendered around 10,000 people homeless already and threaten to displace about 70,000 more in the next 14 years.

The team first noticed that the islands were vanishing while working on a Government of India funded project in 2001. The government census was still showing a population of 5,000 in Ghorama, one of the fast submerging islands. “But we could not find the island in the satellite images. Official records showed 102 islands in the estuary, but we found only 100. Where had the other two gone,” says Hazra of the basic premise which stoked his team’s curiosity.

The researchers then began mapping each island and established that there were 100 islands only. Their report to the Union government was sent recently as part of the national communication to the United Nations Framework Convention on Climate Change (UNFCCC).

As the islands sink, they estimate that the worst hit will be Sagar, from where nearly 30,000 people will be displaced by 2020. Namkhana will have produced 15,000 envirogees by that time. The other islands — all in the western end of the estuarine delta — that will have been deserted are Ajmalmari (east and west), Dalhousie, Dakshin Surendra Nagar, Moushuni, Lothian, Ghoramara, Dulibhasani, Dhanchi, Bulchery, Bhangaduani and Jambudwip. .

Climate casualties

EXTINCT (From top) The Javan Rhino, the One Horned Rhino and the Swamp Deer.

Studying the rainfall patterns, the team has found that though there has been just a marginal increase in rainfall over the years, most of the rains don’t come in the monsoons. “Rainfall has shifted to the post-monsoon period. This shifting is a definite indicator of climate change,” Hazra says.

This has severe implications for the food security in the Sundarbans, which sustains itself on rain-fed paddy. Confirms Pintu Sardar, 22, a refugee from the sinking Ghoramara island, “At times the rains don’t come when we sow our seeds. They come when we are just about to reap the harvest. A lot of our standing crops are lost.” One solution, Hazra says, is to introduce multi-crops in the delta.

Besides the rising seas, climate change fallouts like the extinction of species are also bothering the scientists. “The Royal Bengal Tiger has adapted to drinking salt water. The Cheetal deer (Axis axis), too, has survived as it can excrete excess salt in tears. But many like the water buffalo (Bubalus bubalis), the Javan Rhino (Rhinoceros sondicus), the One Horned Rhino (Rhinoceros unicornis) and Swamp deer have been wiped off from the Sundarbans one after another within the last century,” Hazra says. The Barking deer ( Muntiacus muntijack ) is extinct in all the islands except Halliday.

Is there a threat to the Royal Bengal Tiger? “Eventually, yes. In the southern coast of the Sundarbans, a shallow marine condition (area with pure seawater) has developed owing to sea level rise. The tiger does not seem to like this… It likes a brackish water condition (a mix of sea and river waters). So the tiger is shifting to the northern end of the island,” says Pranabes Sanyal, a former director of the Sundarban Development Board. “Bhangaduani island, which falls in the tiger reserve area, is fast losing land owing to erosion. Two more islands in the south are also becoming smaller by the day. The tiger habitat is undoubtedly shrinking,” he says.

Several plant species, including mangroves (Aegiceras corniculatum, Heritiera fomes, Kandelia kandel, Nypa fruticans) have been affected. “These need immediate conservation measures. Though we know that the mangroves are depleting because of increased salinity, its relation with climate change is yet to be established,” says former national fellow of the Indian Council of Agricultural Research (ICAR) Dr Kumud Ranjan Naskar. Incidentally, the Sundarbans boasts of the largest mangrove biodiversity in the whole world. Concerned over the loss, Naskar and his team are nurturing species of indigenous mangrove plants in a natural genepool project in one of the islands. The idea is to preserve for posterity one specimen of every mangrove species found across the Sundarbans.

Underlying truth

From the very beginning, the islands have been a subsiding delta. A 1962 record with the West Bengal government — the first working plan of the department of forests — says fragments of ‘ceriops’, a mangrove variety, were found below the sea level during excavation around George’s Dock in Calcutta. “But the recent changes in sea level seem more severe,” Hazra warns.

The more literate islanders are worried that no national policy safeguards the envirogees. “What do the new National Disaster Management Policy and the West Bengal government’s disaster management department have for people facing environmental disasters like these,” asks Jateswar Panda, among the few residents of the Sundarbans who went to college.

The country’s natural disaster management revolves around instant calamities like earthquakes, landslides, flash floods and, more recently, drought. “What about slow onset disasters like arsenic or vanishing islands,” he exclaims.

According to some estimates, at least one lakh people will have to be evacuated from the 12 threatened inner estuary islands of the Sundarbans in the next decade if the present rate of submergence continues. The scientists feel it would be wise to plan a gradual shift to safer places like the adjoining North and South 24-Parganas districts rather than wait for a demographic disaster to happen.

The West Bengal government says the JU study is insufficient to prove climate change. Says Atanu Raha, director of the Sunderban Biosphere Reserve, “Accretion and erosion are natural phenomena. Things like a rise in temperature or an increase in sea level have to be studied over hundreds of years. A 30-year study is not enough to come to a conclusion that the climate is changing.”

Raha, who has studied satellite images of the last 20 years, says just as some islands have gone down in the sea, vast land areas like Thakuran char and New Island have emerged out of the sea because of silt deposits.

Posted in Climate | 9 Comments »

Picture perfect phones

Posted by iKnowHOW on October 30, 2006

What should you look out for when buying a new camera cellphone? Here’s a checklist

Say cheese: The K790i from Sony Ericsson has the best sound quality among all the new phones

With a clutch of new 3.2 Megapixel camera phones in the market, it is quite a feat to choose one that is worth the money forked out for it.

Leading the pack is the exquisite N93 from Nokia, which is more a handycam than a phone. Close on its heels are the Samsung D900, Nokia N73 and the Sony Ericsson K790i. And now, there is the world’s first 10 megapixel camera phone. Or is it a camera that doubles up as a phone — it’s difficult to tell. However, the B600, from Samsung, is slated for launch only in South Korea. We will have to bide our time before we can lay our hands on it.

So what can make phone shopping a rewarding experience?

Remember five important factors when you go out to buy a mobile:

• Portability

• Good call quality

• Good battery life

• Great music playback

• Ease of navigation

No phone can score equally high on all the qualities, so you must obviously weigh your options and buy what best suits your priorities.

Nokia’s N93:

Anything but portable, this phone has terrific video camera features that more than make up for its bulk. The N93 runs on the Symbian S60 v3 operating system that makes it capable of running applications like Adobe PDF reader and QuickOffice for viewing PowerPoint, Excel and Microsoft Word documents.

Samsung’s D900:

The B600 (top), from Samsung, is the world’s first 10 megapixel camera phone

Part of the company’s new ultra slim range of stylish phones, this slider phone has an internal memory of 60MB which can be augmented by an external memory slot for a MicroSD card. One of the drawbacks of this phone is that it does not support voice dialing, which is an essential if you are using Bluetooth headsets. Also missing is EDGE (enhanced GPRS) for high speed internet access. It only supports GPRS Class 10 which has a download speed of 32 to 48 kbps. The camera shoots pictures of an average quality, but fails in situations that need high speed photography, so that the slightest movement produces blurred images. A terrible shutter lag in this phone leads to these blurred pictures. However, all this is offset by a Document Viewer which allows you to read Word and PDF files and its ultra stylish appearance.

Nokia N73:

Nokia brought this out to compete with Sony Ericsson’s K790i. By Nokia’s usual standards of clunky looks, this phone is surprisingly sleek and slim. It has a 42 MB internal memory that is expandable with a miniSD card. The Carl Zeiss lens with auto focus takes pretty decent photographs. This phone too runs on the Symbian S60 Version3 operating system and those who want to use this 3G handset for work will be happy with the PDF reader and QuickOffice for Microsoft Word, Excel and PowerPoint documents.

Sony Ericsson K790i:

This phone takes equally good pictures as the N73, if not better, with its Cybershot camera. Cybershot is the line of digital cameras made famous by Sony. So when it was incorporated into the phone it created quite a stir. The phone more than serves your camera needs. In addition, among all the new phones the K790i easily has the best sound quality. Along with HSCSD (High Speed Circuit Switched Data) and EDGE, Internet access is quite fast. The only problem with the phone, as I have found since this is what I use now, is that I don’t have a viewer for PDF and Office documents. The browser on the phone swiftly resizes websites to fit the mobile phone’s smaller screen. There is no horizontal scrolling involved which can get to be quite a pain.

A word of caution for those going in for a new phone. Do not get swayed by 3G phones. This is because 3G networks have not arrived in India as yet. It is slated to come only around 2008. 3G refers to network systems that allow a data transfer rate of nearly 2Mbps. EDGE gives you a data transfer rate up to 384kbps. With 3G networks video calls and streaming movies will become possible on your mobile phones. EDGE gives you streaming video on your phone. You can even watch TV channels such as Aaj Tak and CNBC. However, this is not possible with the current 2.5G networks in India.

The EDGE reception in Calcutta varies from place to place. Certain residential areas like Ballygunge and Alipore or even Park Street have towers which support faster internet access. In other areas internet on the mobile can be painfully slow because just general radio packet switching (GPRS) is available at speeds of only 30 to 80 kbps.

All these phones come with FM capability. But if you are bored with the same kind of music you can listen to Internet radio with your EDGE-enabled phone. One such radio site is Spod radio. You can download the software for your phone from www.spodradio.com and listen to different genres of music ranging from pop, hip hop, rock, classical, jazz, to music of the sixties and seventies. You will get Hindi songs under World Music. For Nokia phones there is Visual Radio. Go to www.visualradio.com on your computer and follow the instructions on how to hear the music on your phone.

I have found a virtual pet shop for my mobile phone to make up for a lack of the real thing. I have two pets now, one dog and one monkey. I have to take my pets for a morning walk, feed them, bathe them, play with them and even take them to the vet regularly. If I neglect them even for half a day, they start withering away. A full day of neglect means my pet will die. Believe me, when that happens it can be very disheartening. To divert your mind you could either play chess or Sudoku. All this and more is available from www.cellufun.com. The Sudoku on your mobile is especially good with different levels. All you have to do is register at the site and then you can download the Sudoku games of your choice for free.

Before you go shopping for a phone check the reviews on the internet. Follow this up with readers comments — they can be quite revealing. Don’t get swayed by the advertisements. There are tools to compare phones at several sites too. A good starting place would be www.gsmarena.com.

Posted in Tech Check | 1 Comment »

Beyond condoms

Posted by iKnowHOW on October 30, 2006

Forty years after the introduction of the female birth control pill, researchers are still optimistic about the feasibility of a male hormonal contraceptive. Regina Nuzzo reports

Family planning: Millions of men would like to have options beyond condoms or vasectomy

Four offsprings are plenty for 37-year-old Glen Magdaleno of Los Angeles. “I love my kids, but I just can’t have any more and still be a good parent,” he says.

Magdaleno, like millions of other men, would like to have options beyond condoms, vasectomy or withdrawal. To those ends, he recently volunteered at Harbor-UCLA Medical Center to test one of several male birth control drugs being developed around the world.

Every day during the month-long study, Magdaleno smeared hormone-laced gel over his upper body. The drug was designed to penetrate his skin, enter his bloodstream and trick his body into shutting down testicular functioning.

Drugs now in development use hormonal methods similar to those used in many female contraceptives. Small studies have found their delivery — a combination of implants, injections and gels — to be generally safe, reversible and effective in lowering sperm counts.

Male hormonal methods work by adding testosterone or other male hormones to the bloodstream. The brain senses these extra hormones and, to keep the reproductive system in balance, sends chemical signals to shut down the testes. This halts production of sperm cells. It also blocks normal production of testosterone — responsible for male characteristics, from facial hair to sex drive — but the added male hormones serve to take up the slack.

Researchers have found they can boost the sperm-suppressing effects of the added male hormones by also administering progestin, a type of hormone used in female birth control pills and found naturally in small amounts in men. The progestin reinforces the chemical messages that shut down the testes.

Sperm production can then be suppressed with even less testosterone, which helps avoid some of the hormone’s side effects, such as its tendency to decrease levels of heart-healthy HDL cholesterol and the possibility of contributing to prostate cancer.

The need for high doses of testosterone makes a male birth control pill tough to formulate, says Dr Christina Wang of the LA Biomedical Research Institute at Harbor-UCLA Medical Center. Drops or spikes in hormonal levels can trigger sperm production, so a steady delivery method is crucial. Unlike estrogen, however, testosterone doesn’t work well in a daily pill. The hormone tends to immediately break down in the liver.

To bypass this route, researchers are instead experimenting with ways to administer hormones directly into the bloodstream — including a combination of slow-release implants, long-lasting injections or daily gels.

Researchers in China are wrapping up the largest of these trials, a two-year efficacy study of approximately 1,000 volunteers, says Kirsten Vogelsong, a scientist at the World Health Organization. Preliminary results suggest that most men remained infertile during the testosterone injection regimen.

A small study in Seattle suggests testosterone might also be effective when applied onto the skin. Thirty-eight volunteers used a daily testosterone gel in addition to slow-release progestin implants. In 90 per cent of the men, sperm counts dropped to infertile levels within six months. Most of these levels returned to normal soon after the trial ended.

For men who dislike daily routines, once-a-year surgery might be more attractive. The Population Council, a non-profit international research organisation in New York, is working on a slow-release implant of a powerful testosterone derivative, says Dr Reginé Sitruk-Ware, executive director of product research and development. This compound — administered through four small plastic rods that release hormones for up to a year — could spare the prostate from long-term side effects, she says. In initial tests in Europe, South America and Los Angeles over the last five years, the drug blocked sperm production completely in 72 out of 87 volunteers. Researchers are now tinkering with the rubber material used in the implant and hope to test a new single-rod implant in clinical trials within a couple of years.

Posted in KnowHOW Health | 3 Comments »

Preventing pregnancy

Posted by iKnowHOW on October 30, 2006

Ovulation occurs in women on the fourteenth day before the onset of the next period. This is the period of maximum fertility
   
The “safe period” method is at times more successful in planning pregnancy than preventing it, and (bottom) an IUD

This column receives many queries about contraception, even if the last article had nothing to do with sex. Is this because, despite our exploding population, our push for family planning and our desire to propagate the one-child norm, sex education is not yet an integral part of the school curriculum?

Our teenagers receive inaccurate, incorrect and inadequate information about sex from folklore, peers, pornography and the Internet.

Contraception is not really a licentious 20th century notion. Nobody ever wanted to reproduce every time they had sex. Egyptian women inserted vaginal tablets made from mildly acidic substances, the French used a hair from a horse’s mane and sometimes honey or oil was poured into the vagina soon after intercourse to prevent conception. The Chinese used the first female condoms — a cervical blocking cap made of oiled paper. The first male condoms were made of animal intestine and were used in the 17th century.

These methods were unpleasant and inefficient, so the science of contraception evolved to produce the more reliable methods that we have today.

Women can prevent pregnancy by abstinence (not having sex at all). Timed intercourse is more popular than abstinence and is considered “natural”. The “safe period” when unprotected intercourse is least likely to result in a pregnancy is carefully calculated. Ovulation (release of the egg) occurs in women on the fourteenth day before the onset of the next period and that is the period of maximum fertility. Avoiding intercourse for five days before and after this date decreases the chances of an unwanted pregnancy. This method can be combined with “coitus interruptus,” when ejaculation is controlled and takes place outside the vagina.

Women do not function like machines. Menstrual cycles can suddenly lengthen or shorten, making this an unreliable method. Its efficiency can be increased by watching the consistency of the cervical mucous. This changes from clear and transparent to sticky and opaque in the safe period. The body temperature also rises by 0.5 degree C during ovulation and this can be measured daily with a thermometer. All these methods require an understanding and compliant male partner, and are more successful in planning pregnancy than preventing it.

Oral contraceptive pills (OCPs) taken by women are safe, popular and reliable provided they are taken as prescribed, at the same time every day. They are combinations of synthetic estrogens and progesterones and are taken for 21 days at a stretch. Then there is a “pillfree” interval of seven days, during which menstruation occurs. Some companies provide a 28-day pack, in which the last seven tablets are placebos. If a pill is forgotten, two should be taken the next day. If there have been two or more pill-free days, contraception is not assured. The actual formulation of the various hormones in the pills marketed vary. The pill best suited to that particular individual can be prescribed. Pills are contra-indicated in those with complicated diabetes, thrombo-embolism, sickle cell disease, cancer of any reproductive organ and undiagnosed vaginal bleeding.

Progesterone-only pills are also available and can be used in women in whom estrogens are contra-indicated. They are taken continuously with no pill-free interval.

India has also developed a contraceptive tablet called centchroman which belongs to the SERM (Selective Estrogen Receptor Molecule) group of medications.

OCPs are very safe and can be taken for years. They do not increase the risk of cancer or decrease the chances of a subsequent pregnancy.

For women who cannot remember to take their tablets, long acting progesterone injections like medroxyprogesterone acetate or norethisterone acetate can be given every 12 and 8 weeks, respectively. Alternatively, an IUD (intrauterine device) can be inserted and left in situ to prevent pregnancy for around three years.

Condoms, both male and female, if properly used from the beginning to the end of intercourse protect against both pregnancy and STD. Their efficacy is increased if they are combined with a spermicidal cream.

Accidents can occur and people may have sex first and remember contraception afterwards. The government has licensed the use of “emergency contraceptive morning after pills”. They are effective if taken within 72 hours.

Abortion is legal in India and medical methods with mifepristone and misoprost can be used up to 49 days.

If the pregnancy is more advanced, surgical methods like suction or dilatation curettage are needed. Permanent contraception can be achieved by surgical sterilisation, a tubectomy in women and vasectomy in men.

Pregnancy can occur if contraception is not used during lactation, with irregular cycles or even if there has been prompt douching.

Responsibility for safe sex rests with both partners. However, unfortunately, it is the women who display the obvious outward results of an unprotected sexual encounter. Would men be more careful if they were the ones becoming pregnant?

Posted in KnowHOW Health | 1 Comment »