September 29, 2003
September 26, 2003
Another random fact
This is how photocopies are made... It is a 3 step process:
1. light reflected from the white parts of the original is focused onto a charged printing "drum," where it locally dissipates charge;
2. positively charged toner particles are attracted to the remaining charged areas that were dark in the original;
3. paper is run over the drum to pick up the toner to create an image of the original.
September 25, 2003
Global warming This article appreared
Global warming
This article appreared in The New York Times about 2 weeks ago. It talks about evidence of changes in the world due to global warming and what could happen if the warming trend continues. It is an interesting read. Here are a few lines from it...
Skeptics of global warming should come to this Eskimo village on the Arctic Ocean, roughly 250 miles north of the Arctic Circle. It's hard to be complacent about climate change when you're in an area that normally is home to animals like polar bears and wolverines, but is now attracting robins. A robin even built its nest in town this year (there is no word in the local Inupiat Eskimo language for robins).
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The Okpilak River valley was historically too cold and dry for willows, and in the Inupiat language "Okpilak" means "river with no willows." Yet a warmer, wetter climate means that now it's crowded with willows.
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Alaska has warmed by eight degrees, on average, in the winter, over the last three decades, according to meteorological records.
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In the hamlet of Deadhorse, I ran into an Arctic native named Jackson Snyder, who said that winters were getting "a lot warmer; doesn't get much below 50 below anymore."
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That may not seem so bad. But while there will be benefits to a warmer Alaska (a longer growing season, ice-free ports), climate change can also lead to crop failures, spread tropical diseases and turn Bangladesh into tidal pools. The pace of warming may be far too fast for animals, humans or ecosystems to adjust. My advice is that if you're planning a dream home in New Orleans or on the Chesapeake, put it on stilts.
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It predicted that in this century, the seas will rise 4 to 35 inches. Global warming is still an uncertain threat, but it may well become one of the major challenges of this century. Unless we act soon, we may find waves lapping the beaches of Ohio.
Thanks, Mayuresh.
Another interesting fact
Why do we hear a thunderclap?
The average temperature of lightning is 76000 F. In that split second when lightning appreas, the extreme temperature expands the air violently. This explosion of air creates the sound wave that we hear as a thunderclap.
September 23, 2003
If 'Lord of the Rings'
If 'Lord of the Rings' is made in Hindi, they would not have to animate Gollum. Shah Rukh Khan is perfect to play that role. All the nervous twitches and shakiness match perfectly.
September 11, 2003
B-flat Black hole The numbers
B-flat Black hole
The numbers in this article are just astounding... This supermassive blackhole is 250 million light years away. The frequency of the sound is 1 cycle per 9.5 million years. Whoooa!
After observing the Perseus galaxy cluster for 53 hours in August 2002, the Chandra X-ray Observatory revealed ripples in the hot gas that fills the cluster. These ripples appear to be sound waves that would register as a B flat if we could hear the deep tone. The team that discovered the waves determined their frequency by calculating the speed of sound in that environment and measuring the distance between wave crests. The frequency is about one cycle (or wave) per 9.5 million years or so; corresponding to a B-flat note about 57 octaves below "middle C" on a piano.
September 09, 2003
September 05, 2003
BJP's favourite West Asian
This article is written by Mani Shankar Aiyar, a major proponant and benefactor of minority vote-bank politics; belongs to the same group of government bashers as Prafool Bidwai. They forgot to make any noise about being fair and balanced when Yasar Arafat was making trips to India. Oh, wait! But, that was supporting their vote-bank politics. So, it was perfectly fine to welcome Arafat to India without paying any attention to the Israeli side. Mr. Aiyar talks about 80 years of Indian tradition in supporting the Palestinian cause. There was no India before 1947 and there was no Israel before the end of the world war II in 1945. So, what is he talking about? Indian support of Palestine is one of the planks of vote-bank politics, nothing else. It needs to be dumped. It doesn't matter what Sharon did in his previous life. He will visit India as democratically elected representative of Israel. India must develop good relationship with Israel, improve trade, and learn from their experience of fighting terrorism.
Why some wines make you pucker?
NMR spectroscopy is routinely used for determination of chemical structure of small molecules as well as to study three-dimensional structure and interactions of big biomolecules. Non-traditionally, it has also been a tool in solving exotic problems such as quality control of Olive oil. Here is another NMR exotica. In the recent issue of Biochemistry an article was published by a French group (of course!!) describing the use of NMR in studying wine tannin and saliva protein complexes to understand the astringent taste of red wines. The polyphenolic tannins of red wines come primarily in two varieties: the flavan-3-ol polymers (made of catechin and epicatechin monomers) from the grape skins and seeds, and the hydrolyzable tannins (made of ellagic and gallic acids) from the oaken barrels. These compounds are responsible for the astringent taste of red wine and are thought to bind to proline-rich proteins (PRPs) in saliva. Previous attempts to define this interaction have been hampered by the limited solubility of the complexes. Working in the remarkably true-to-life solvent of water:ethanol (88:12 v/v; pH 3.5), Simon et al. describe the association of three procyanidin B3(catechin-4a,8-catechin) molecules with a 14-residue fragment of salivary protein IB7. Using circular dichroism, mass spectrometry, NMR, and molecular dynamics calculations, they find that the peptide adopts a type II helical structure typical of proline-rich sequences. Here is how they describe a "Molecular Vision of Astringency"
Protein-tannin interaction is the source of astringency, the mouth dryness sensation due to the complexation of the lubricant salivary proteins. It is often asked why very different feelings are perceived depending on wines. This may be linked to the specific type of interaction between tannins and proteins that may depend on tannins and protein nature and also to the stability and the lifetime of complexes. We have shown herein that the IB7 fragment from saliva protein can complex three B3 tannins and that the interaction occurs in the hydrophilic side of the peptide. The peculiar structure of the peptide can play an important role here. In the absence of tannins it appears very flexible and offers type II helices (proline-rich parts) for binding. Once complexed, the conformational freedom of the peptide, as well as that of the entire complex, appears much reduced. Is this phenomenon related to astringency? It is interesting trying to predict what would be the stoichiometry for B3 interacting with the entire IB7 human saliva protein. Because the IB714 sequence is almost con-tained three times in IB7, one could guess that a 1/9 complex could be stabilized. If this happened to be true, PRP proteins of the IB7 family could be called “tannin sponges”.Whereas the properties of PRP become unveiled, the specificity of the tannin counterpart is more subtle. It probably depends on its chemical nature (hydrolyzable, condensed, galloylated, etc.). Its molecular weight, 3D structure, ropensity to auto-associate, and water solubility may lead to noticeable differences in the protein-tannin complex formation. This explains, perhaps, the gustative differences noticed by enologists about tannin behavior in red wine such as drying, puckering, sour, astringent, bitter, or rough character. Of interest is the fact that the tannin binding sites appear to have different physicochemical properties. In our case the sites appear to have different dynamics. This might be linked to their lifetime that could modulate the time during which the proteins are complexed and therefore no longer available to lubricate the mouth.
September 03, 2003
Certifiable Moron
It is hard to believe that this certifiable moron was a senior editor at Times of India and is probably being said to write idiotic articles like the following on Rediff.com.
Shanti and Gaurav have dissected his article very well. Worth reading.
