Chemical process that causes eyes to tear when we peel onion

The rowdy onion joins the aristocratic shallot, the gentle leek, the herbaceous chive, sharp scallion and assertive garlic among the 500 species of the genus Allium. Allium cepa is an ancient vegetable, known to Alexander the Great and eaten by the Israelites during their Egyptian bondage. Indeed, his charges chastened Moses for leading them away from the onions and other flavorful foods that they had come to relish while in captivity. And with good reason: onion is a rich source of nutrients, including vitamins B, C , protein, starch and a series of essential elements. The chemicals contained in onions are reported to be effective agents against fungal and bacterial growth; they protect against stomach, colon and skin cancers; they have anti-inflammatory, antiallergenic, antiasthmatic and antidiabetic actions; and they treat causes of cardiovascular disorders, including hypertension, hyperglycemia and hyperlipidemia while also inhibiting platelet aggregation.

The price of this goodness is tears. The volatile oils that help to give Allium vegetables their distinctive flavors contain a class of organic molecules known as amino acid sulfoxides. Peeling, cutting or crushing an onion’s tissue releases enzymes called allinases, which convert these molecules to sulfenic acids. The sulfenic acids, in turn, spontaneously rearrange to form syn-propanethial-S-oxide, the chemical that triggers the tears. syn-Propanethial S-oxide (C3H6OS) (IUPAC: 1-Sulfinylpropenea), member of a class of organosulfur compounds known as thiocarbonyl S-oxides (formerly “sulfines”),is a gas that acts as a lachrymatory agent (triggers tearing and stinging on contact with the eyes).They also condense to form odorous thiosulfinates, coincidentally evoking the pungent odor associated with chopping onions and eliciting the false accusation that it is the odor that causes the weepy eye. Incidentally, sulfenic acid in garlic takes a different chemical route, sparing the eyes. The formation of syn-propanethial-S-oxide peaks at about 30 seconds after mechanical damage to the onion and completes its cycle of chemical evolution over about five minutes.

Its effects on the eye are all too familiar. The front surface of the eye–the cornea–serves several purposes, among them protection against physical and chemical irritants. The cornea is densely populated with sensory fibers of the ciliary nerve, a branch of the massive trigeminal nerve that brings touch, temperature and pain sensations from the face and front of the head. The cornea also receives a smaller number of autonomic motor fibers that activate the lachrymal (tear) glands. Free nerve endings detect syn-propanethial-S-oxide on the cornea and drive activity in the ciliary nerve–which the central nervous system interprets as a burning sensation–in proportion to the compound’s concentration. This nerve activity reflexively activates the autonomic fibers, which then carry a signal back to the eye ordering the lachrymal glands to wash the irritant away.

There are several solutions to the problem of onion tears. You can heat onions before chopping to denature the enzymes. You might also try ways to limit contact with the vapors: chop onions on a breezy porch, under a steady stream of water or mechanically in a closed container.


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Alcohol and your body

What alcohol really does to your body?




From heart to liver and brain to kidneys, a night on the tiles makes demands on us that we don’t fully realise.

* One unit of alcohol is defined as 10 ml (7.9 gms) in UK

6pm One Unit*: It’s been a long day…

BRAIN: From the first sip, alcohol is absorbed into the bloodstream and reaches the brain. Although you won’t be aware of it, there is an impairment of brain function, which deteriorates further the more you drink. Cognitive abilities that are acquired later in life, such as conduct and behaviour, are the first to go. Early on you will experience mild euphoria and loss of inhibition, as alcohol impairs regions of the brain controlling behaviour and emotion. Most vulnerable are the brain cells associated with memory, attention, sleep and coordination. Sheer lack of mass means that people who weigh less become intoxicated more quickly, and women will feel the effects faster than men. This is also because their bodies have lower levels of water.

HEART: Your pulse quickens after just one unit. Alcohol is a vasodilator – it makes the peripheral blood vessels relax to allow more blood to flow through the skin and tissues, which results in a drop in blood pressure. In order to maintain sufficient blood flow to the organs, the heart rate increases. Your breathing rate may also speed up.

8pm Five Units: Whose round is it then?

DIGESTIVE SYSTEM: The Government advises men to drink no more than three to four units a day and women no more than two to three, so after two pints of normal-strength beer (four units) or a large glass of red wine (3.5 units) we have already exceeded our healthy guidelines. The alcohol is absorbed through the stomach and small intestine and if you are not used to it, even small amounts of alcohol can irritate the stomach lining. This volume of alcohol also begins to block absorption of essential vitamins and minerals.

SKIN: Alcohol increases blood-flow to the skin, making you feel warm and look flushed. It also dehydrates, increasing the appearance of fine lines. According to Dr Nicholas Perricone, a dermatologist, even five units will lead to an unhealthy appearance for days.

11pm 10 Units: Sorry, what was your name again?

LUNGS: A small amount of alcohol speeds up the breathing rate. But at this level of intoxication, the stimulating effects of alcohol are replaced by an anaesthetic effect that acts as a depressant on the central nervous system. The heart rate lowers, as does blood pressure and respiration rates, possibly to risky levels – in extreme cases the effect could be fatal. During exhalation, the lungs excrete about 5 per cent of the alcohol you have consumed – it is this effect that forms the basis for the breathalyser test.

1am 15 Units: Let me tell you about my ex…

LIVER: Alcohol is metabolised in the liver and excessive alcohol use can lead to acute and chronic liver disease. As the liver breaks down alcohol, by-products such as acetaldehyde are formed, some of which are more toxic to the body than alcohol itself. It is these that can eventually attack the liver and cause cirrhosis. A heavy night of drinking upsets both the delicate balance of enzymes in the liver and fat metabolism. Over time, this can lead to the development of fatty globules that cause the organ to swell. It is generally accepted that drinking more than seven units (men) and five units (women) a day will raise the risk of liver cirrhosis.

3am 20 Units: Where am I? I need to lie down

HEART: More than 35 units a week, or a large number in one sitting, can cause ‘holiday heart syndrome’. This is atrial fibrillation – a rapid, irregular heartbeat that happens when the heart’s upper chambers contract too quickly. As a result, the heartbeat is less effective at pumping blood from the heart, and blood may pool and form clots. These can travel to the brain and cause a stroke. Atrial fibrillation gives a person nearly a fivefold increased risk of stroke. The effect is temporary, provided heavy drinking is stopped.

BLOOD: By this stage, alcohol has been carried to all parts of the body, including the brain, where it dissolves into the water inside cells. The effect of alcohol on the body is similar to that of an anesthetic – by this stage, inhibitions are lost and feelings of aggression will surge.

The morning after: Can you please just shut up…

BRAIN: Alcohol dehydrates virtually every part of the body, and is also a neurotoxin that causes brain cells to become damaged and swell. This causes the hangover and, combined with low blood-sugar levels, can leave you feeling awful. Cognitive abilities such as concentration, coordination and memory may be affected for several days.

DIGESTION: Generally, it takes as many hours as the number of drinks you have consumed to burn up all the alcohol. Feelings of nausea result from dehydration, which also causes your thumping headache.

KIDNEYS: Alcohol promotes the making of urine in excess of the volume you have drunk and this can cause dehydration unless extra fluid is taken. Alcohol causes no damage or harm to the kidneys in the short term, but your kidneys will be working hard.

One year on: Where did it all go wrong?

REPRODUCTIVE ORGANS: Heavy drinking causes a drop in testosterone levels in men, and causes testicular shrinkage and impotence. In females, menstrual cycles can be disrupted and fertility is affected. Studies have shown that women who drink up to five units of alcohol a week are twice as likely to conceive as those who drink 10 or more. It is thought it may affect the ability of the fertilized egg to implant.

BRAIN: Over time, alcohol can cause permanent damage to the connection between nerve cells. As it is a depressant, alcohol can trigger episodes of depression, anxiety and lethargy.

HEART: Small amounts of alcohol (no more than a unit a day) can protect the heart, but heavy drinking leads to chronic high blood pressure and other heart irregularities.

BLOOD: Alcohol kills the oxygen-carrying red blood cells, which can lead to anaemia.

CANCER: Excessive alcohol consumption is linked to an increase in the risk of most cancers. Last week, Cancer Research UK warned how growing alcohol use is causing a steep rise in mouth cancer cases.

PANCREAS: Just a few weeks of heavy drinking can result in painful inflammation of the pancreas, known as pancreatitis. It results in a swollen abdominal area and can cause nausea and vomiting.


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Fastest Insect

The fastest insect in the world are divided into ground speed and flying speed. 


                                        A Bush Cockroach

The fastest insect on the ground is the cockroach. In an experiment carried out at the University of California, Berkeley in 1991, an American cockroach registered a record speed of 5.4 kmph* (3.4 mph*), about 50 body lengths per second, which would be comparable to a human running at 330 kmph (210 mph).



                          Dragonfly emerging as an adult

The fastest flying insect is the dragon fly. It was claimed that the Southern Giant Darner flying at nearly 60 mph (97 kmph) in a rough field measurement, but a more reliable record shows a 35 mph speed.


       Oleander hawk moth (Daphnis nerii), in MangaonMaharashtraIndia

Sphingids or (hawk moths) are one of the fastest flying insects as well, some are capable of flying at over 50 kmph (30 mph). They have a wingspan of 35-150 mm.


* kmph=kilometre per hour,mph=mile per hour


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The Very Large Telescope — The World’s Most Advanced Visible-light Astronomical Observatory (At 2600m Altitude, Atacama Desert region of Chile: Paranal):


The Very Large Telescope array (VLT) is the flagship facility for European ground-bas
ed astronomy at the beginning of the third millennium. It is the world’s most advanced optical instrument, consisting of four Unit Telescopes with main mirrors 8.2 metres in diameter and four movable 1.8-metre Auxiliary Telescopes. The telescopes can work together, in groups of two or three, to form a giant VLT Interferometer (VLTI) allowing astronomers to see details up to 25 times finer than with the individual telescopes. The light beams are combined in the VLTI using a complex system of mirrors in underground tunnels where the light paths must be kept equal to distances less than 1/1000 mm over a hundred metres. With this kind of precision the VLTI can reconstruct images with an angular resolution of milliarcseconds, equivalent to distinguishing the two headlights of a car at the distance of the Moon.

The 8.2-metre Unit Telescopes can also be used individually to obtain images of celestial objects as faint as magnitude 30 in a one-hour exposure. This corresponds to seeing objects that are four billion times fainter than those visible to the naked eye.The VLT instrumentation programme is the most ambitious ever conceived for a single observatory. It includes large field imagers, adaptive optics corrected cameras and spectrographs, as well as high resolution and multi-object spectrographs and covers a broad spectral region, from deep ultraviolet (300 nm) to mid-infrared (20 μm) wavelengths. The 8.2-metre telescopes are housed in compact, thermally controlled buildings, which rotate synchronously with the telescopes. This design minimises any adverse effects on the observing conditions, for instance, from air turbulence in the telescope tube, which might otherwise occur due to variations in temperature and wind flow. The first of the Unit Telescopes, Antu, began routine scientific operations on 1 April 1999. Today, all four Unit Telescopes and all four Auxiliary Telescopes are operational. The VLT has made an undisputed impact on observational astronomy. It is the most productive individual ground-based facility, and results from the VLT have led to the publication of an average of more than one peer-reviewed scientific paper per day. VLT contributes greatly to making ESO the most productive ground-based observatory in the world. The VLT has stimulated a new age of discoveries, with several notable scientific firsts, including the first image of an exoplanet, tracking individual stars moving around the supermassive black hole at the centre of the Milky Way, and observing the afterglow of the furthest known gamma-ray burst. Although the four 8.2-metre Unit Telescopes can be combined in the VLTI, they are mostly used for individual observations and are only available for interferometric observations for a limited number of nights every year. But four smaller, dedicated Auxiliary Telescopes (ATs) are available to allow the VLTI to operate every night. The ATs are mounted on tracks and can be moved between precisely defined observing positions from where the beams of collected light are combined in the VLTI. The ATs are very unusual telescopes, as they are self-contained in their ultra-compact protective domes, and travel with their own electronics, ventilation, hydraulics and cooling systems. Each AT has a transporter that lifts the telescope and moves it from one position to the other.


About ESO:
ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO plays also a leading role in promoting and organising cooperation in astronomical research.ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor.

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Jagadish Chandra Bose

(The unsung Hero of Radio Communication):

Jagadish Chandra Bose (Indian Scientist) was born in India in 1858. He received his education first in India, until in 1880 he went to England to study medicine at the University of London. Within a year he moved to Cambridge to take up a scholarship to study Natural Science at Christ’s College Cambridge. One of his lecturers at
Cambridge was Professor Rayleigh, who clearly had a profound influence on his later work. In 1884 Bose was awarded a B.A. from Cambridge, but also a B.Sc. from London University. Bose then returned to India, taking up a post initially as officiating professor of physics at the Presidency College in Calcutta. Following the example of Lord Rayleigh, Jagadis Bose made extensive use of scientific demonstrations in class; he is reported as being extraordinarily popular and effective as a teacher. Many of his students at the Presidency College were destined to become famous in their own right – for example S.N. Bose, later to become well known for the Bose-Einstein statistics.

A book by Sir Oliver Lodge, “Heinrich Hertz and His Successors,” impressed Bose. In 1894, J.C. Bose converted a small enclosure adjoining a bathroom in the Presidency College into a laboratory. He carried out experiments involving refraction, diffraction and polarization. To receive the radiation, he used a variety of different junctions connected to a highly sensitive galvanometer. He plotted in detail the voltage-current characteristics of his junctions, noting their non-linear characteristics. He developed the use of galena crystals for making receivers, both for short wavelength radio waves and for white and ultraviolet light. Patent rights for their use in detecting electromagnetic radiation were granted to him in 1904. In 1954 Pearson and Brattain [14] gave priority to Bose for the use of a semi-conducting crystal as a detector of radio waves. Sir Neville Mott, Nobel Laureate in 1977 for his own contributions to solid-state electronics, remarked [12] that “J.C. Bose was at least 60 years ahead of his time” and “In fact, he had anticipated the existence of P-type and N-type semiconductors.”

In 1895 Bose gave his first public demonstration of electromagnetic waves, using them to ring a bell remotely and to explode some gunpowder. In 1896 the Daily Chronicle of England reported: “The inventor (J.C. Bose) has transmitted signals to a distance of nearly a mile and herein lies the first and obvious and exceedingly valuable application of this new theoretical marvel.” Popov in Russia was doing similar experiments, but had written in December 1895 that he was still entertaining the hope of remote signalling with radio waves. The first successful wireless signalling experiment by Marconi on Salisbury Plain in England was not until May 1897. The 1895 public demonstration by Bose in Calcutta predates all these experiments. Invited by Lord Rayleigh, in 1897 Bose reported on his microwave (millimeter-wave) experiments to the Royal Institution and other societies in England [8]. The wavelengths he used ranged from 2.5 cm to 5 mm. In his presentation to the Royal Institution in January 1897 Bose speculated [see p.88 of ref.8] on the existence of electromagnetic radiation from the sun, suggesting that either the solar or the terrestrial atmosphere might be responsible for the lack of success so far in detecting such radiation – solar emission was not detected until 1942, and the 1.2 cm atmospheric water vapor absorption line was discovered during experimental radar work in 1944. Figure 1 shows J.C. Bose at the Royal Institution in London in January 1897; Figure 2 shows a matching diagram, with a brief description of the apparatus.

By about the end of the 19th century, the interests of Bose turned away from electromagnetic waves to response phenomena in plants; this included studies of the effects of electromagnetic radiation on plants, a topical field today. He retired from the Presidency College in 1915, but was appointed Professor Emeritus. Two years later the Bose Institute was founded. Bose was elected a Fellow of the Royal Society in 1920. He died in 1937, a week before his 80th birthday; his ashes are in a shrine at the Bose Institute in Calcutta.


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Swallow’s Nest Castle

“Swallow’s Nest” is a castle, built in the late XIX century near Yalta, in the South of Crimea. Situated on the steep cliff right over the sea, it has become the symbol of the South coast of Crimea and one the of the most exciting point of interests of the whole resort.

30 years ago a wounded general came for treatment to the Crimea. For heroism in the Crimean war, the empire awarded him a land plot by the sea. On the high rock of Ai-Todor Cape, the warrior built a small wooden house: he was looking for solitude, romanticism and calm, just blue sky and Black Sea. The veteran called his humble house “The Castle of Love”. But history does not say whether it was love for a woman or for the incredible beauty of CrimeaThis is how the “career” of the most famous castle of Crimea, the Swallow’s Nest, began in 1877. Its absolutely anonymous beginning totally fulfilled its first owner’s wishes of calm and solitude. How surprised would be the owner if he knew that, over a century, the venue of his retirement would turn into a tourists’ Mecca, replicated on thousands of calendars and postcards! This despite the fact that finding the path to the palace is not obvious: the castle is not visible from the road and only following the crowds of tourists will show the way.

The names of the owner and architect of the original modest house over the abyss are unknown. Then this solitary retreat passed on to court doctor A. Tobin, then to the wife of a Moscow businessman, Mrs. Rakhmanova. She started settling on Ai-Todor Cape on an imperial scale: she pulled down the old building and built a more eminent one which she renamed “Swallow’s Nest”.

It is a very appropriate name: the small gray house is perched high on a 40-metre rock and exposed to the elements. At the same time, it is cozy and calm.

The feeling of quiet is such here that it seems it can be boxed and sold to tourists as a souvenir. Ancient Romans, who founded their settlements on the cape, understood this. Medieval monks, who built a monastery dedicated to Saint Fedor (Todor, from whom the Turkic name of the cape is derived) on the rock also acknowledged this fact. When the Turks conquered Crimea in 1475, the monastery was closed and this place became deserted. In 1835, a lighthouse was erected here, and then it saw the building of its romantic neighbor, the hero of our story.

How did a wooden summer residence turn into a beautiful, if diminutive, castle? The new owner of the rock, oil magnate baron von Steingel decided to build a more refined structure. In 1910 architect Vsevolod Sherwood came to Crimea on his honeymoon. The baron, who dreamed about a nook of the Rhine by the Black Sea, asked the architect for a concept suitable for a romantic castle. Sherwood was captivated by this work and, as soon as 1912, the castle was ready and waiting for baron von Steingel. However, the baron did not enjoy his stone fairytale very long: in 1914, the building was bought by Moscow businessman P. Shelaputin, who opened a restaurant on the premises.

The architect managed the impossible: Swallow’s Nest is monumental and at the same time elegant, majestic and weightless. It is beloved by tourists, enjoys an incredible “stardom” and has even achieved the status of icon of Crimean peninsula.

Having reached the castle, you realise that it is actually very small as palaces go: it is 12 metres high, the base is 10 by 20 metres, there are only two floors, just a few rooms (hall, living-room, two bedrooms, now converted into an Italian restaurant.) It is hard to believe that the palace once was surrounded by a garden: during the great earthquake of 1927, the part of the rock where trees were planted fell into the sea. Since this disaster 80 years ago, part of the balustrade of Swallow’s Nest has been hanging over the sea without a foundation. It is both a scary and exciting sight.

Though the palace itself was damaged very little, it became necessary to save it from sliding into the sea. There were several rescue projects. One of them would have had the castle dismantled and all its stones numbered and then re-assembled again as far as possible from cliffs and abysses. Fortunately, this idea was not implemented. Repairs were performed in 1967-68 by employees of a construction company from Yalta. The balustrade that hung over the sea received a concrete support block, and the palace itself got “suspended” in anti-seismic belts.

Tradesman Shelaputin’s vision turned out to be a pot of gold: in 1970, the castle became a restaurant again. And now by the souvenir shops, among numerous knick-knacks, mementos, and trinkets, a swallow’s song hangs like a leitmotif, hymn to the romantic castle of love on the high rock.

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Srinivasa Ramanujan

Srinivasa Ramanujan (Indian Mathematician: 22 December 1887-26 April 1920):

Srinivasa Ramanujan

Ramanujan’s name will always be linked to Godfrey Harold Hardy, a British mathematician. It is not because Ramanujan worked with Hardy at Cambridge but it was Hardy who made it possible for Ramanujan to go to Cambridge. Hardy, widely recognised as the leading mathematician of his time, championed pure mathematics and had no interest in applied aspects. He discovered one of the fundamental results in population genetics which explains the properties of dominant, and recessive genes in large mixed population, but he regarded the work as unimportant.

Encouraged by his well-wishers, Ramanujan, then 25 years old and had no formal education, wrote a letter to Hardy on January 16, 1913. The letter ran into eleven pages and it was filled with theorems in divergent series. Ramanujan did not send proofs for his theorems. He requested Hardy for his advice and to help getting his results published. Ramanujan wrote : “I beg to introduce myself to you as a clerk in the Accounts Department of the Port Trust Office at Madras on a salary of only £ 20 per annum. I have had no university education but I have undergone the ordinary school course. After leaving school I have been employing the spare time at my disposal to work at mathematics. I have not trodden through the conventional regular course which is followed in a university course, but I am striking out a new path for myself. I have made a special investigation of divergent series in general and the results I get are termed by the local mathematicians as “startling“… I would request you to go through the enclosed papers. Being poor, if you are convinced that there is anything of value I would like to have my theorems published. I have not given the actual investigations nor the expressions that I get but I have indicated the lines on which I proceed. Being inexperienced I would very highly value any advice you give me “. The letter has become an important historical document. In fact, ‘this letter is one of the most important and exciting mathematical letters ever written’. At the first glance Hardy was not impressed with the contents of the letter. So Hardy left it aside and got himself engaged in his daily routine work. But then he could not forget about it. In the evening Hardy again started examining the theorems sent by Ramanujan. He also requested his colleague and a distinguished mathematician, John Edensor Littlewood (1885-1977) to come and examine the theorems. After examining closely they realized the importance of Ramanujan’s work. As C.P. Snow recounted, ‘before mid-night they knew and knew for certain’ that the writer of the manuscripts was a man of genius’. Everyone in Cambridge concerned with mathematics came to know about the letter. Many of them thought `at least another Jacobi in making had been found out’. Bertrand Arthur William Russell (1872-1970) wrote to Lady Ottoline Morell. “I found Hardy and Littlewood in a state of wild excitement because they believe, they have discovered a second Newton, a Hindu Clerk in Madras … He wrote to Hardy telling of some results he has got, which Hardy thinks quite wonderful.”

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