Virtual Aquaria

Pink & Purple Fish

Fri, 21 Sep 2007 21:14:46 +0000

fish swimming around in a coral reef

Deepsea soundscape

Thu, 30 Aug 2007 18:36:25 +0000

aquarium featuring 15 exotic fish,sharks and eels!A unique impression of underwater life.. Welcome to the virtual aquarium!Watch these fish swim around. They have all the colors of the rainbow

Underwater scene

Fri, 17 Aug 2007 19:45:51 +0000

New aquarium featuring 12 exotic fish,sharks and eels! Welcome to the virtual aquarium!Watch these fish swim around. They have all the colors of the rainbow.

Virtual Aquarium episode #1

Fri, 10 Aug 2007 19:10:35 +0000

An aquarium, featuring sharks and fish swimming around in a coral reef.

Underwater #1

Thu, 05 Jul 2007 20:27:41 +0000

Watch these fish swim around. They have all the colors of the rainbow.

An aquarium, featuring sharks and fish swimming around in a coral reef.Aquaria can can come in more creative flavors.

The Star-Spangled Banner

Mon, 02 Jul 2007 20:49:06 +0000

"The Star-Spangled Banner" One of two surviving copies of the 1814 broadside printing of the Defence of Fort McHenry, a poem that later became the national anthem of the United States. National Anthem Writer(s) Francis Scott Key (lyrics) "The Star-Spangled Banner" is the national anthem of the U.S.A., with lyrics written in 1814 by Francis Scott Key. Key, a 35-year-old lawyer and amateur poet, wrote them as a poem after seeing the bombardment of Fort McHenry in Baltimore, Maryland, by British ships in Chesapeake Bay during the War of 1812. The poem, titled "Defence of Fort McHenry," was set to the tune of the popular British drinking song "The Anacreontic Song", more commonly known by its first line, "To Anacreon in Heaven," and became a well-known American patriotic song. With a range of one and a half octaves, it is known for being notoriously difficult to sing. It was recognized for official use by the Navy in 1889 and the President in 1916, and was made the national anthem by a Congressional resolution on 3 March 1931 (46 Stat. 1508, codified at 36 USC §301). Although the song has four stanzas, only the first is commonly sung today, with the fourth ("O thus be it ever when free men shall stand ...") added on more formal occasions. History Early history An artist's rendering of the battle at Fort McHenry.On September 3, 1814, Key and John S. Skinner, an American prisoner-exchange agent, set sail from Baltimore aboard the sloop HMS Minden flying a flag of truce on a mission approved by U.S. President James Madison. Their objective was to secure the release of Dr. William Beanes, the elderly and popular town physician of Upper Marlboro, a friend of Key’s who had been captured in his home. Beanes was accused of aiding in the arrest of British soldiers. Key and Skinner boarded the British flagship, HMS Tonnant, on 7 September and spoke with Major General Robert Ross and Admiral Alexander Cochrane over dinner, while they discussed war plans. At first, Ross and Cochrane refused to release Beanes, but relented after Key and Skinner showed them letters written by wounded British prisoners praising Beanes and other Americans for their kind treatment. Because Key and Skinner had heard details of the plans for the attack on Baltimore, they were held captive until after the battle, first aboard HMS Surprise, and later back on Minden. After the bombardment, certain British gunboats attempted to slip past the fort and effect a landing in a cove to the west of it, but they were turned away by fire from nearby Fort Covington, the city's last line of defense. During the rainy night, Key had witnessed the bombardment and observed that the fort’s smaller "storm flag" continued to fly, but once the shelling had stopped, he would not know how the battle had turned out until dawn. By then, the storm flag had been lowered, and the larger flag had been raised. 15-star, 15-stripe "Star-Spangled Banner" flag Francis Scott Key's original manuscript copy of his Star-Spangled Banner poem. It is now on display at the Maryland Historical Society.Key was inspired by the American victory and the sight of the large American flag flying triumphantly above the fort. This flag, with fifteen stars and fifteen stripes, came to be known as the Star Spangled Banner Flag and is today on display in the National Museum of American History, a treasure of the Smithsonian Institution. It was restored in 1914 by Amelia Fowler, and again in 1998 as part of an ongoing conservation program. Aboard the ship the next day, Key wrote a poem on the back of a letter he had kept in his pocket. At twilight on 16 September, he and Skinner were released in Baltimore. He finished the poem at the Indian Queen Hotel, where he was staying, and he entitled it "Defense of Fort McHenry." Key gave the poem to his brother-in-law, Judge Joseph H. Nicholson. Nicholson saw that the words fit the popular melody "To Anacreon in Heaven", an old British drinking song from the mid-1760s, composed in London by John Stafford Smith. Nicholson took the poem to a printer in Baltimore, who anonymously printed broadside copies of it—the song’s first known printing—on 17 September; of these, two known copies survive. On 20 September, both the Baltimore Patriot and The American printed the song, with the note "Tune: Anacreon in Heaven". The song quickly became popular, with seventeen newspapers from Georgia to New Hampshire printing it. Soon after, Thomas Carr of the Carr Music Store in Baltimore published the words and music together under the title "The Star-Spangled Banner", although it was originally called "Defense of Fort McHenry." The song’s popularity increased, and its first public performance took place in October, when Baltimore actor Ferdinand Durang sang it at Captain McCauley’s tavern. The song gained popularity throughout the nineteenth century and bands played it during public events, such as July 4 celebrations. On 27 July 1889, Secretary of the Navy Benjamin F. Tracy signed General Order #374, making "The Star-Spangled Banner" the official tune to be played at the raising of the flag. In 1916, President Woodrow Wilson ordered that "The Star-Spangled Banner" be played at military and other appropriate occasions. Although the playing of the song two years later during the seventh-inning stretch of the 1918 World Series is often noted as the first instance that the Anthem was played at a baseball game, evidence shows that the "Star-Spangled Banner" was performed as early as 1897 at Opening Day ceremonies in Philadelphia and then more regularly at the Polo Grounds in New York City beginning in 1898. Today, the anthem is performed before the first pitch at every game. On 3 November 1929, Robert Ripley drew a panel in his syndicated cartoon, Ripley's Believe it or Not!, saying "Believe It or Not, America has no national anthem." [3] In 1931, John Philip Sousa published his opinion in favor, stating that "it is the spirit of the music that inspires" as much as it is Key’s "soul-stirring" words. By a law signed on 3 March 1931 by President Herbert Hoover, "The Star-Spangled Banner" was adopted as the national anthem of the United States. Modern historyThe first modern non-traditional arrangement of the anthem heard by mainstream America was by Puerto Rican singer and guitarist Jose Feliciano. He stunned the crowd at Tiger Stadium in Detroit and the rest of America when he strummed a slow, bluesy rendition of the national anthem before Game 5 of the 1968 World Series between Detroit and St. Louis. This rendition started contemporary "Star-Spangled Banner" controversies. The response from many in Vietnam-era America was generally negative, given that 1968 was a tumultuous year for the United States. Despite the controversy, Feliciano's performance opened the door for the countless interpretations of the "Star-Spangled Banner" we hear today. [4] Another famous instrumental interpretation is Jimi Hendrix’s guitar solo at the first Woodstock Festival. Incorporating sonic effects to emphasize the "rockets' red glare" and "bombs bursting in air", it became a late-1960s emblem. In March 2005, the government-sponsored The National Anthem Project was launched after a Harris Interactive poll showed many adults knew neither the lyrics nor the history of the anthem. [1] LyricsO say, can you see, by the dawn’s early light,What so proudly we hailed at the twilight's last gleaming,Whose broad stripes and bright stars, through the perilous fightO’er the ramparts we watched, were so gallantly streaming?And the rockets’ red glare, the bombs bursting in airGave proof through the night that our flag was still there;O say, does that star-spangled banner yet waveO’er the land of the free and the home of the brave? [show]Second, third and fourth verses of The Star-Spangled Banner On the shore, dimly seen thro’ the mist of the deep,Where the foe’s haughty host in dread silence reposes,What is that which the breeze, o’er the towering steep,As it fitfully blows, half conceals, half discloses?Now it catches the gleam of the morning’s first beam,In full glory reflected, now shines on the stream’Tis the star-spangled banner. Oh! long may it waveO’er the land of the free and the home of the brave! And where is that band who so vauntingly sworeThat the havoc of war and the battle’s confusionA home and a country should leave us no more?Their blood has washed out their foul footsteps' pollution.No refuge could save the hireling and slaveFrom the terror of flight, or the gloom of the grave,And the star-spangled banner in triumph doth waveO’er the land of the free and the home of the brave. Oh! thus be it ever, when freemen shall standBetween their loved homes and the war’s desolation,Blest with vict’ry and peace, may the Heav’n-rescued landPraise the Power that hath made and preserved us a nation!Then conquer we must, when our cause it is just,And this be our motto: "In God is our Trust"And the star-spangled banner in triumph shall waveO’er the land of the free and the home of the brave. ProtocolWhen the song is performed in public, it is customary for American citizens to stand and face the American flag, if one is displayed, in an attitude of respectful attention[5]. If no flag is on display, it is customary to stand and face the source of the music in the same respectful attitude of attention as if the flag were on display. Men are also encouraged to remove their hats during the performance. Boy Scouts, Girl Scouts, and military personnel, fire service, and law enforcements officer in uniform, normally salute during the national anthem from the first note and hold the salute until the last note is played. [2] TranslationsThe anthem has also been translated into other languages. In 1861, it was translated into German. [6] It has been translated into Yiddish by Jewish immigrants [7], and into French by Acadians of Louisiana [8]. The third verse of the anthem has also been translated into Latin. [9] It has been translated into Samoan; here are the last four lines of the first verse: O roketi mumu fa'aafi, o pomu ma fana ma aloi afi E fa'amaonia i le po atoa, le fu'a o lo'o tu maninoa. Aue! ia tumau le fe'ilafi mai, ma agiagia pea I eleele o sa'olotoga, ma nofoaga o le au totoa.[3]. Nuestro HimnoA Spanish-language recording of the "Star-Spangled Banner" called "Nuestro Himno" was released on 28 April 2006. This was a few days before nationwide demonstrations on 1 May regarding immigration-law reform. This recording was created as a show of support for all immigrants, the majority of whom are of Hispanic origin, in the United States in response to a proposed crackdown on illegal immigration. "Nuestro Himno" used the text of the Spanish-language version translated by Francis Haffkine Snow of the "The Star-Spangled Banner" called "La Bandera de Estrellas." This version was published by the US Bureau of Education in 1919. This same translation is on the United States Department of State's website. A reproduction of the original sheet music is on the Library of Congress website. Public reaction to "Nuestro Himno" was widely divided. It drew this response from President George W. Bush: "I think people who want to be a citizen of this country ought to learn English and they ought to learn to sing the national anthem in English." [4] President Bush's administration had Spanish versions of the Anthem posted online. [5] PerformancesMain article: Performances and adaptations of The Star-Spangled BannerThe song is notoriously difficult for nonprofessionals to sing, because its range is wide: an octave and a half. Garrison Keillor has frequently campaigned for the performance of the anthem in the original key, G major—which can, in fact, be managed by most average singers without difficulty.[6] (It is usually played in A-flat or B-flat.) Humorist Richard Armour referred to the song's difficulty in his book It All Started With Columbus “ In an attempt to take Baltimore, the British attacked Fort McHenry, which protected the harbor. Bombs were soon bursting in air, rockets were glaring, and all in all it was a moment of great historical interest. During the bombardment, a young lawyer named Francis Scott Key wrote "The Star-Spangled Banner", and when, by the dawn's early light, the British heard it sung, they fled in terror! ” Professional and amateur singers have been known to forget the words, which is one reason the song is so often prerecorded and lip-synched. This situation was lampooned in the comedy film The Naked Gun, as its star Leslie Nielsen, undercover as opera singer Enrico Pallazzo at a baseball game, made mincemeat of the lyrics. The prerecording of the anthem has become standard practice at some ballparks (such as Boston's Fenway Park, according to the SABR publication The Fenway Project) [10]. Musical referencesThe tune has been referenced in many other musical compositions. The city of Philadelphia commissioned Richard Wagner to write a piece in honor of the centenary of U.S. independence. His American Centennial March uses a recurring allusion to "The Star-Spangled Banner" in its main theme. The nineteenth-century American composer Louis Moreau Gottschalk incorporated both "The Star-Spangled Banner" and "Yankee Doodle" in his piano composition The Union. Giacomo Puccini controversially used the opening phrases of "The Star-Spangled Banner" as a theme for the character of Pinkerton in his opera Madama Butterfly. The last of Leopold Godowsky's set of thirty piano pieces titled Triakontameron is "Requiem (1914–1918): Epilogue", which concludes with a full-blown romantic arrangement of the anthem. The paraphrase of the first stanza is used in the score of American Panorama (1933) by Daniele Amfitheatrof. The title tune of the 1960s musical Hair contains the lines (sung to the usual tune) "O, say, can you see / my eyes? If you can / then my hair's too short!" In the musical 1776 the song "Cool, Cool Considerate Men" starts and ends with the beginning bars of "The Star-Spangled Banner" and begins with the lyrics "Oh say do you see what I see?" In the multi-media performance piece "Home of the Brave", by artist/musician Laurie Anderson. The rock guitarist Jimi Hendrix performed the Star Spangled Banner at Woodstock, one of his most memorable performances. Motion Picture References

Underwater #3

Fri, 29 Jun 2007 18:16:58 +0000

aquarium,fish,underwater,reef,fishtank,shark,corals,seaweed,goldfish,eelgrass,snails,kreisel,jellyfish,water,filtration,swimming

Another aquarium, featuring sharks and fish swimming around in a coral reef
Aquaria can can come in more creative flavors. Aquariums have been fashioned into coffee tables, sinks, and even toilets.

Another such example is the Macquarium, an aquarium made from the shell of an Apple Macintosh computer
A kreisel tank is a circular aquarium designed to hold delicate animals such as jellyfish

Ruby,Ruby,Ruby!

Thu, 28 Jun 2007 18:51:25 +0000

No, it's not the Kaiser chiefs , but the original gemstone

Phenomena
Sometimes rubies show a 3-point or 6-point star. These Rubies are cut into cabochons to display the effect properly. Stars are best visible with a single-light source, and move across the stone as the light moves. Such effects are called asterism and occur when light is reflected off the silk (the rutile inclusions) in a certain way. This is one example where inclusions actually increase the value of a gemstone. Rubies can furthermore show color changes — though this occurs very rarely — and chatoyancy.

Treatments
Improving the quality of gemstones, and thus treating them, has been a practice of all ages. The level of treatment however can differ considerably and impact the price of a gemstone accordingly. Some treatments occur in almost all cases and are (therefore) considered "acceptable" practices. As with most gemstones, the most accepted and most occurring treatment is heat treatment. Although heat treatment affects the price of a top quality ruby, most if not all rubies at the lower end of the market are heat treated. Heat treatment is performed on the rough stones to improve color, remove purple tingle, blue patches and silk. These heat treatments typically occur around temperaturs of 1800°C (3272°F).[1] Some rubies undergo a process of low tube heat, when the stone is heated over charcoal of a temperature of about 1300°C (2372°F) for 20 to 30 minutes. The silk is only partially broken as the color is improved.

A less acceptable treatment, and one which has gained notoriety in recent years is "Lead Glass Filling" of Rubies. By filling the fractures inside the ruby with so-called "lead glass" the transparency of the stone is dramatically improved making previously unsuited rubies now fit for applications in jewelry. The process is typically split into 4 steps:

Rough stones are pre-polished to eradicate all surface impurities that may affect the process
Rough is cleaned with Hydrogen Fluoride
First heating process whereby no fillers are added. The heating process eradicates impurities inside the fractures. Although this can be done at temperatures up to 1400°C (2552°F) it most likely occurs at a temperature of around 900°C (1636°F) since the Rutile silk is still intact
Second heating process in an electrical oven with different chemical additives. Different solutions and mixes have shown to be successful, however mostly lead-containing glass-powder is used at present. The Ruby is dipped into oil, then covered with powder, embedded on a tile and placed in the over where it is heated at around 900°C (1636°F) for one hour in an oxidizing atmosphere. The Orange colored powder transforms upon heating into a transparent to yellow-colored paste, which fills all fractures. After cooling the color of the paste is fully transparent, that dramatically improves the overall transparency of the Ruby.
In case a color needs to be added, the glass powder can be "enhanced" with Copper or other Metal Oxides as well as elements such as Sodium, Calcium, Potassium etc.

The Second heating process can be repeated three to four times consecutively, even applying different mixtures.[2]

Synthetic and imitation rubies
Synthetic rubies have been made since the late 19th century. They have become more common since the work of Auguste Verneuil and the introduction of the flame fusion process. Other processes in which synthetic rubies can be produced are through the Pulling process, flux process, and the hydrothermal process. Most synthetic rubies originate from flame fusion, due to the low costs involved. Synthetic rubies may have no imperfections visible to the naked eye but magnification may reveal curves striae and gas bubbles. The fewer the number and the less obvious the imperfections, the more valuable the ruby is; unless there are no imperfections (i.e., a "perfect" ruby), in which case it will be suspected of being artificial. Dopants are added to some manufactured rubies so they can be identified as synthetic, but most need gemmological testing to determine their origin. Imitation rubies have also been present in the gemstone market for some time. Red spinel, red garnet and even glass have been falsely named as rubies. Trade terms such as balas ruby for red spinel and rubellite for red tourmaline can mislead unsuspecting buyers. Such terms are therefore discouraged from being used by many gemological associations such as the Gemological Institute of America (GIA).

Records
Although pieces of red corundum can be found weighing many kilograms, they are generally not of sufficient quality to be valuable as gemstones. For this reason, auction prices are the best indicator of a stone's true value, and prices do not necessarily correlate with size. As of 2006, the record price paid at auction for a single stone was $5,860,000 for an unnamed 38.12 carat cabochon-cut ruby.[3] However, other stones with potentially greater value may never have been sold at auction.

Trivia
This article contains a trivia section.
The article could be improved by integrating relevant items into the main text and removing inappropriate items.

This article has been tagged since June 2007.
A synthetic ruby crystal was used to create the first laser (See Ruby laser).
According to Rebbenu Bachya, and the New International Version, the word odem means "ruby" in the verse Exodus 28:17 (referring to a stone on the Hoshen), and was the stone representing the tribe of Reuben. Modern Hebrew has taken this meaning. However, odem actually means earth, and is cognate with Adam; in the middle east, the earth it refers to is certainly reddish, but the Septuagint translates the term as Sard (which also means red), which is also the name of an incredibly common somewhat opaque gem. Scholars think the stone intended is probably a Sard, as does the King James Version, scholars think that if not a Sard it may possibly be the related gem carnelian; it is thought possible that Sard and Odem here just mean the colour of the stone, and red Jasper would therefore also be a possibility. There is a wide range of views among traditional sources about which tribe the stone refers to.
Ruby is the most commonly named precious stone in English translations of the Bible; an example being Proverbs 31: "A virtuous wife is worth more than rubies.". The underlying masoretic text doesn't necessarily refer to rubies, however. Not only are there issues such as that mentioned with odem, but in the case of Proverbs 31, the masoretic text merely states jewels, and the Septuagint makes Proverbs 31 refer to precious stones (estin lithon ); some English versions of the bible believe that pearls is a better translation here.
The famous lighted "Red Stars" mounted above Kremlin spires, thought to be giant rubies mined in Siberia, are actually colored glass.

Ruby is the birthstone associated with July and of the

Underwater

Tue, 26 Jun 2007 19:29:43 +0000

Another aquarium, featuring sharks and fish swimming around in a coral reef

Balloons over the stadium

Fri, 22 Jun 2007 21:25:52 +0000

balloon contest!!

Aquarium 1 (Fish Tank)

Tue, 19 Jun 2007 19:31:26 +0000

Aquaria can can come in more creative flavors. Aquariums have been fashioned into coffee tables, sinks, and even toilets.
Another such example is the Macquarium, an aquarium made from the shell of an Apple Macintosh computer
A kreisel tank is a circular aquarium designed to hold delicate animals such as jellyfish

Happy Feet:It's raining penguins.

Fri, 08 Jun 2007 19:07:40 +0000

Penguins live in colonies in the Antarctic, in freezing
temperatures. No tap dancing in this animation though.
Penguins are are a group of aquatic, flightless birds living almost exclusively in the Southern Hemisphere.
The largest living species is the Emperor Penguin.
Most penguins feed on krill, fish, squid, and other forms of sealife caught while swimming underwater. They spend half of their life on land and half in the oceans.

Penguins seem to have no fear of humans and have approached groups of explorers without hesitation. This is probably on account of there being no land predators in Antarctica or the nearby offshore islands that prey on or attack penguins. Instead, penguins are at risk at sea from predators such as the leopard seal.

Penguins are popular around the world, primarily for their unusually upright, waddling pace and (compared to other birds) lack of fear of humans. Their striking black and white plumage is often likened to a tuxedo suit and generates humorous remarks about the bird being "well dressed". Perhaps in reaction to this cutesy stereotype, fictional penguins are occasionally presented as grouchy or even sinister. Penguins have also been the subject of many books and documentary films such as Happy Feet and Surf's Up, both CGI-Animated Animal Adventure Films, March of the Penguins, a documentary based on the migration process of penguins, and a parody film entitled Farce of the Penguins. Mistakenly, some artists and writers have penguins based in the North Pole.
French Pingouin, German Pinguin

Shine on you crazy diamonds

Fri, 01 Jun 2007 19:27:04 +0000

Shine On You Crazy Diamond" is an epic nine-part Pink Floyd composition with lyrics written by Roger Waters, in tribute to former band member Syd Barrett, and music written by Waters, Richard Wright, and David Gilmour. It was first performed on their 1974 tour.[1] It was recorded for the 1975 concept album Wish You Were Here. The song was intended to be a side-long composition like "Atom Heart Mother" and "Echoes," but the song grew longer than a single side of vinyl would allow. It was split into two parts and used to bookend the album. The name of the song is a reference to Syd Barrett: Shine on You crazy Diamond.

The Emerald

Thu, 24 May 2007 18:54:48 +0000

A rare type of emerald known as a trapiche emerald is occasionally found in the mines of Colombia. A trapiche emerald exhibits a "star" pattern; it has raylike spokes of dark carbon impurities that give the emerald a six-pointed radial pattern. It is named for the trapiche, a grinding wheel used to process sugarcane in the region. Colombian emeralds are generally the most prized due to their transparency and fire. Some of the most rare emeralds come from three main emerald mining areas in Colombia: Muzo, Coscuez, and Chivor. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia.

The value of an emerald depends on cut, color, clarity, and carat. The characteristics of Colombian emeralds set the highest standards of quality

Emerald is regarded as the traditional birthstone for May, as well as the traditional gemstone for the astrological signs of Taurus and Cancer

Diamonds are a girl's best friend

Sat, 12 May 2007 16:22:44 +0000

Diamond is the hardest natural material known to man and the third-hardest known material after aggregated diamond nanorods and ultrahard fullerite. Its hardness and high dispersion of light make it useful for industrial applications and jewelry.

Diamonds are specifically renowned as a material with superlative physical qualities — they make excellent abrasives because they can be scratched only by other diamonds, Borazon, ultrahard fullerite, or aggregated diamond nanorods, which also means they hold a polish extremely well and retain their lustre. About 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion.[citation needed] About 100,000 kg are synthesized annually.[2]

The name diamond derives from the ancient Greek adamas

"Diamonds Are a Girl's Best Friend" is a song perhaps most famously performed by Marilyn Monroe in the 1953 film Gentlemen Prefer Blondes. In a later scene, Jane Russell, who played opposite of Monroe, sang "Diamonds Are a Girl's Best Friend" in court. Monroe's rendition of the song has been considered an iconic performance and since been copied by other entertainers ranging from Madonna and Kylie Minogue to Anna Nicole Smith. The song was also featured in 2001 film Moulin Rouge!, sung by Nicole Kidman.

"Diamonds Are a Girl's Best Friend" was introduced by Carol Channing in the original Broadway production of Gentlemen Prefer Blondes (1949), which was written by Jule Styne (who also wrote the scores for such famed Broadway musicals as Funny Girl and Gypsy) and Leo Robin.

"Shine On You Crazy Diamond" is an epic nine-part Pink Floyd composition with lyrics written by Roger Waters, in tribute to former band member Syd Barrett, and music written by Waters, Richard Wright, and David Gilmour. It was first performed on their 1974 tour.[1] It was recorded for the 1975 concept album Wish You Were Here. The song was intended to be a side-long composition like "Atom Heart Mother" and "Echoes," but the song grew longer than a single side of vinyl would allow. It was split into two parts and used to bookend the album. The name of the song is a reference to Syd Barrett: Shine on You crazy Diamond.

Vitamin D: a cure for cancer?

Sat, 12 May 2007 16:03:44 +0000

The vitamin D hormone, calcitriol, has been found to induce death of cancer cells in vitro and in vivo. Although the anti-cancer activity of vitamin D is not fully understood, it is thought that these effects are mediated through vitamin D receptors expressed in cancer cells, and may be related it its immunomodulatory abilities. The anti-cancer activity of vitamin D observed in the laboratory has prompted some to propose that vitamin D supplementation might be beneficial in the treatment or prevention of some types of cancer.

In 2005, scientists released a study which demonstrated a beneficial correlation between vitamin D intake and prevention of cancer. Drawing from a meta-analysis of 63 published reports, the authors showed that intake of an additional 1,000 international units (IU) (or 25 micrograms) of vitamin D daily reduced an individual's colon cancer risk by 50%, and breast and ovarian cancer risks by 30%. Research has also shown a beneficial effect of high levels of calcitriol on patients with advanced prostate cancer.

Research has suggested that cancer patients who have surgery or treatment in the summer — and therefore get more vitamin D — have a better chance of surviving their cancer than those who undergo treatment in the winter when they are exposed to less sunlight

Pulp Fiction : Adrenalin shot straight to the heart

Sat, 12 May 2007 15:36:35 +0000

To refresh your memory, hit man Vincent (John Travolta) has the job of squiring his boss's wife, Mia (Uma Thurman), around town. While he's in the bathroom, she discovers his stash of what she thinks is cocaine and promptly snorts some. Bad idea--it's actually high-octane heroin. Vincent returns to find her comatose and frantically drives her to the home of his dealer Lance (Eric Stoltz), who hands Vincent a railroad-spike-sized syringe. The following classic dialogue ensues over the supine Mia:

Lance: OK, you're giving her an injection of adrenaline straight to her heart. But she's got breastplates. You've gotta pierce through that. So what you gotta do is, you gotta bring the needle down in a stabbing motion. [Makes multiple stabbing motions]

Vincent: I gotta stab her three times?

Lance: No, you don't gotta fucking stab her three times! You gotta stab her once, but it's gotta be hard enough to get through her breastplate into her heart, all right? And then once you do that, you press down on the plunger.

Vincent: OK, then what happens?

Lance: I'm curious about that myself.

Vincent does as instructed. Mia immediately sits bolt upright, eyes wide open and apparently fully recovered.

OK, this isn't a 100 percent accurate depiction of what would actually occur. But here's the thing: doctors honest to God do on (rare) occasion jab a big hypodermic of epinephrine, aka adrenaline, directly into the heart of someone who's gone into cardiac arrest, a technique called intracardiac injection (ICI). If the patient is lucky she revives quickly--epinephrine is the fight-or-flight hormone that blasts through your system in moments of extremity. So there's a grain of truth to the scene. But only a grain. Among the problematic details: (1) The heart isn't beneath the "breastplate" (presumably Lance means the breastbone, or sternum--the heart is to the left of this), and in any case only a fool would try to force a needle through bone--you'd go between the ribs. (2) A cardiac arrest victim getting ICI doesn't instantly jerk up like the alarm clock just went off--the heart might restart right away, but it would take a while to regain consciousness. (3) Mia's problem probably isn't cardiac arrest anyway--the immediate consequence of heroin overdose is severe respiratory depression. As long as her heart keeps beating, ICI is pointless. If Mia needs an injection of something, a plain old intravenous shot will work just fine, since her blood is still circulating. (4) Epinephrine wouldn't sober up someone who was OD'ing. To neutralize heroin you'd administer a drug such as Narcan (naloxone), which blocks the opiate receptors in the brain and can bring a junkie back to earth in a matter of minutes.

Desperate housewives: botox rules

Fri, 27 Apr 2007 20:55:15 +0000

Teri Hatcher has confessed to being a Botox fan.

The 41-year-old actress, who revived her career playing Susan Mayer in Desperate Housewives, admitted she has had a little help in keeping her face linefree.

"In the past I've had Botox and collagen," she admitted in an interview in America. Botox injections are said to smooth out wrinkles by paralysing facial muscles while collagen plumps up parts that are losing their lustre, especially lips
Botox® is a trade name for botulinum toxin A. In this way, Botox® is related to botulism. Botulism is a form of food poisoning that occurs when someone eats something containing a neurotoxin produced by the bacterium Clostridium botulinum. Botulinum toxin A is one of the neurotoxins produced by Clostridium botulinum.
The show takes place on the fictional Wisteria Lane in the American suburban town of Fairview, located in the fictional Eagle State. It follows the lives of four women, seen through the eyes of their dead neighbor - only two of whom are actually housewives as of January 2007 - as they work through domestic struggles while several mysteries unfold in the background. Desperate Housewives combines many styles such as: drama, comedy, mystery, thriller, farce, camp, soap opera and satire.

The show stars Golden Globe award winning actresses Teri Hatcher and Felicity Huffman, TV veterans Marcia Cross and Nicollette Sheridan, and rising star Eva Longoria. Since the second pilot episode, Brenda Strong narrates the series

Movie Facts: 'E.R.'(emergency room) : " sux!!! "

Fri, 27 Apr 2007 20:47:16 +0000

Suxamethonium chloride (also known as succinylcholine, scoline, or colloquially as sux) is a medication widely used in emergency medicine and anesthesia to induce muscle relaxation, usually to make endotracheal intubation possible. Suxamethonium is sold under several trade names such as Anectine, and may be referred to as "sux" for short.

Suxamethonium acts as a depolarizing neuromuscular blocker. It imitates the action of acetylcholine at the neuromuscular junction, but it is not degraded by acetylcholinesterase but by pseudocholinesterase, a plasma cholinesterase. This hydrolysis by pseudocholinesterase is much slower than that of acetylcholine by acetylcholinesterase

Jurassic Park: security measure failure

Fri, 27 Apr 2007 20:40:52 +0000

In the film Jurassic Park, the dinosaurs have their DNA modified so that they cannot produce lysine and must be supplied with it by the park's feeding system, otherwise they will eventually die. This is a security measure to prevent the creatures from spreading if they ever escaped into the outside world. In the book, the dinosaurs escape and survive by eating things rich in lysine such as soybeans and lentils.
Lysine synthesis. Intermediates of the glutamate and the aspartate family are coupled in just the same way as in the arginine and asparagine synthesis. Lysine can be generated in two ways. Both are named according to their most characteristic intermediates. Green algae, ferns and higher plants take one pathway, some green flagellates (euglenophyta) and fungi the other.
Jurassic Park is a 1993 science fiction film directed by Steven Spielberg, based upon the novel of the same name by Michael Crichton. On the island of Isla Nublar, scientists have created an amusement park of cloned dinosaurs. John Hammond (Richard Attenborough) invites a group of scientists, played by Sam Neill, Jeff Goldblum and Laura Dern, to visit the park during one weekend. Sabotage sets the carnivorous dinosaurs on the loose, and technicians and visitors attempt to escape the island.

Movie Facts: Truth Serum (used by CTU in "24")

Fri, 27 Apr 2007 20:24:47 +0000

A truth serum is a drug used for the purposes of obtaining accurate information from an unwilling subject,
most often by a police, intelligence, or military organization on a prisoner.
Drugs used for this purpose have included ethanol, scopolamine, and sodium thiopental
(known as Sodium Pentothal)
In episode 12 of season 5 in 24 (TV series), Jack Bauer contacts CTU
to tell them to prep an interogation room and for a medic to stand by with hyocine pentathol,
another form of truth serum
---
In episode 118 of MacGyver, a prisoner is given the choice of confessing freely or being injected with Sodium Pentothal.
Jonathan Adams' alternative comic book originally published by Slave Labor Graphics and later self-published by City Cyclops is titled Truth Serum.
In Thomas Harris' first Hannibal Lecter novel Red Dragon, FBI agent Will Graham mentions that when previous attempts to gain information from Lecter, regarding the location of one of his victims' bodies, using truth drugs like sodium pentathol, they only succeeded in him giving them 'a recipe for dip'.
Karin Boye's dystopic novel Kallocain, originally published in 1940, is named after, and based around a fictional truth serum.
In the James Bond film Octopussy, the villain Kamal Khan tells Bond that a combination of curare and a psychedelic agent gave "guaranteed results" as a truth drug, although at the cost of permanent insanity for the recipient.
The U.S. television series Alias features repeated references to Sodium Pentothal as a truth drug.

"Prison Break":How Michael Scofield fakes diabetes

Fri, 27 Apr 2007 20:16:15 +0000

-PUGNAc 5mg can be obtained from TRC,Toronto Research Chemicals for $125
-PUGNAc is a drug, acting as an inhibitor of glucosidase and so increasing
insulin resistance.
-PUGNAc was used by Michael Scofield in the television series Prison Break
to keep his blood sugar level high, in order to appear both diabetic and to
be resistant to insulin shots he was receiving butdid not need

______________--

Before he takes the Pugnac:

Dr. Tancredi: Your blood glucose is at fifty milligrams per deciliter. Your body’s reacting to the insulin as though your not a diabetic. Are you sure it’s Type 1 Diabetes you got.

Michael: Ever since I was a little kid.

Dr. Tancredi: Alright. Not experiencing any tingling sensations, cold sweats?

(Michael shakes his head and is saved by the phone. He gets and walks over to the barred window, looking outside. He notices his right hand is shaking and smoothes his left thumb over the palm. Dr. Tancredi gets off the phone.)

I’d like to run some tests the next time your in. The last thing I want is to be administering insulin to a man who doesn’t.

____________________

Lincoln: What the hell’s a Pugnac?

Michael: It lowers my insulin to the point where I’m hypoglycemic and as long as the good doctor thinks I’m diabetic I’ll have plenty of time in there to do what I need to do.

____

After he takes the Pugnac:

Dr. Tancredi: It used to take hours, but we’ve come a long way with the new glucose kits. This’ll take us ten seconds. (Michael looks apprehensive) Slide this strips into the meter then we’re ready to go. I’m sure you know this but, the average glucose for a non- diabetic is about one hundred milligrams per deciliter. We see a number like that here and we know you’ve been misdiagnosed.

Dr. Tancredi: Ah. Bad news I’m afraid. (She shows him the meter) one hundred and eighty milligrams per deciliter. You are definitely diabetic.

Movie Facts: The 'Sentox' Nerve gas in '24'

Fri, 27 Apr 2007 20:00:53 +0000

-the 'sentox' nerve gasin '24' refers to 'VX' gas
-VX is the deadliest nerve gas in the world
-in the series '24',nerve gas killed(amongst others): Edgar Stiles and Lynn 'Mr' McGill
-penetrates the body trough the air or through the skin
-blocks neurotransmission that activates muscles
-atropine is an antidote
-causes death by suffocation.
-Symptoms:blur vision,small pupils,dizzyness,foam from mouth,
unvoluntary vomiting , urinating and defecation, convulsions,coma and
suffocation
-The only countries known to possess VX are the United States and Russia
-As little as 200 micrograms is enough to kill an average person
-VX was featured in the movie '
The Rock'
--
Nerve agents (also known as nerve gases, though these chemicals are liquid at room temperature) are a class of phosphorus-containing organic chemicals (organophosphates) that disrupt the mechanism by which nerves transfer messages to organs. The disruption is caused by blocking acetylcholinesterase, an enzyme that normally relaxes the activity of acetylcholine, a neurotransmitter. As chemical weapons, they are classified as weapons of mass destruction by the United Nations according to UN Resolution 687, and their production and stockpiling was outlawed by the Chemical Weapons Convention of 1993; the Chemical Weapons Convention officially took effect on April 29, 1997. [1] Poisoning by a nerve agent leads to contraction of pupils, profuse salivation, convulsions, involuntary urination and defecation, and eventual death by asphyxiation as control is lost over respiratory muscles. Some nerve agents are readily vaporized or aerosolized and the primary portal of entry into the body is the respiratory system. Nerve agents can also be absorbed through the skin, requiring that those likely to be subjected to such agents wear a full body suit in addition to a respirator.

The Anthrax Toxin

Mon, 16 Apr 2007 07:25:22 +0000

Anthrax is an acute infectious disease caused by the bacterium Bacillus anthracis and is highly lethal in some forms. Anthrax most commonly occurs in wild and domestic ruminants, but it can also occur in humans when they are exposed to infected animals, tissue from infected animals, or high density of anthrax spores. There are no known cases of infection in humans resulting from direct contact with a diseased person. The word anthrax is derived from the Greek word anthrakis, or "coal", in reference to the black skin lesions victims develop.

How tamiflu kills bird flue

Mon, 16 Apr 2007 06:57:03 +0000

an antiviral drug that is used in the treatment and prophylaxis of both Influenzavirus A and Influenzavirus B. Like zanamivir, oseltamivir is a neuraminidase inhibitor. It acts as a transition-state analogue inhibitor of influenza neuraminidase, preventing new viruses from emerging from infected cells. It has also been found that the standard recommended dose incompletely suppresses viral replication in at least some patients with H5N1 avian influenza, rendering therapy ineffective and increasing the risk of viral resistance

Double Laser ball

Sat, 07 Apr 2007 12:59:49 +0000

Special effects animation of a metal ball with 60 laser beams moving
in all directions

Why leaves are green

Sat, 07 Apr 2007 12:49:37 +0000

Chlorophyll is a green photosynthetic pigment found in most plants, algae, and cyanobacteria. Its name is derived from ancient Greek: chloros = green and phyllon = leaf. Chlorophyll absorbs most strongly in the blue and red but poorly in the green portions of the electromagnetic spectrum, hence the green color of chlorophyll-containing tissues like plant leaves.
Chlorophyll is vital for photosynthesis, which helps plants get energy from light

When the headache is over (aspirin)

Sat, 07 Apr 2007 12:41:14 +0000

Aspirin overdose has potentially serious consequences, sometimes leading to significant morbidity and mortality. Patients with mild intoxication frequently have nausea and vomiting, abdominal pain, lethargy, tinnitus, and dizziness
All overdose patients must be taken to a hospital immediately. Contrary to the urban legend, one can die from ingesting a bottle of pills, even if they are subsequently thrown up

Blood Transport

Sat, 07 Apr 2007 12:33:57 +0000

Serum albumin, often referred to simply as albumin, is the most abundant plasma protein in humans and other mammals. Albumin is essential for maintaining the osmotic pressure needed for proper distribution of body fluids between intravascular compartments and body tissues. The human version is human serum albumin. Bovine serum albumin, or BSA, is commonly used in molecular biology laboratories.

Albumin is negatively charged. The glomerular basement membrane is also negatively charged; this prevents the filtration of albumin in the urine. In nephrotic syndrome, this property is lost, and there is more albumin loss in the urine. Nephrotic syndrome patients are given albumin to replace the lost albumin.

Because smaller animals (for example rats) function at a lower blood pressure, they need less oncotic pressure to balance this, and thus need less albumin to maintain proper fluid distribution.

Resistance to antibiotics

Sat, 31 Mar 2007 18:34:40 +0000

The first major development was ampicillin, which offered a broader spectrum of activity than either of the original penicillins. Further development yielded beta-lactamase-resistant penicillins including flucloxacillin, dicloxacillin and methicillin. These were important for their activity against beta-lactamase-producing bacteria species, but are ineffective against the methicillin-resistant Staphylococcus aureus strains that subsequently emerged.

The line of true penicillins were the antipseudomonal penicillins, such as ticarcillin and piperacillin, useful for their activity against Gram-negative bacteria. However, the usefulness of the beta-lactam ring was such that related antibiotics, including the mecillinams, the carbapenems and, most importantly, the cephalosporins, have at the centre of their structures.

Running Nose a.k.a. The Rhinovirus

Sat, 31 Mar 2007 18:26:44 +0000

Vaccines

Antibodies are our major defense against these small, efficient viruses. Vaccines prime the immune system with antibodies, making it ready to fight an infection. In the case of poliovirus, there are two types of vaccines. One is a killed version of the virus, which is slowly killed with formaldehyde over the course of several days so that it is inactivated, but still keeps its proper shape. The second is a weakened, but still live, strain of the virus that has been artificially bred to stimulate the immune system without causing disease. The immune system responds by making antibodies to fight these weakened viruses, leaving it ready to fight the real thing when it comes along.

The polio vaccines are one of the triumphs of modern medicine, but many people would say that the lack of a cure for the common cold is one of the great failings. The difficulty of creating a vaccine for the common cold lies in the diversity of rhinovirus. Over one hundred types of rhinovirus have been discovered as they strike people around the world, and new strains appear continually. Rhinovirus is a moving target that is not effectively combated with a single vaccine. Antiviral drugs, however, are a possible solution.

Picornavirus Structure

Many viruses, including the picornaviruses and bacteriophage phiX174 (discussed in an earlier Molecule of the Month), are icosahedral in shape. They are composed of 60 identical pieces that form a perfectly symmetrical shell, termed a capsid, around the viral genome. In the case of poliovirus and rhinovirus, the shell is composed of 60 copies of four different proteins (colored yellow, orange, red, and magenta on rhinovirus here, PDB entry 4rhv), for a total of 240 protein chains in all. Notice that the fourth chain, colored magenta, can only be seen on the inside surface of the capsid. These proteins are carefully designed to be stable, but not too stable. They must be fairly sturdy to allow the virus to pass from host to host through the hostile environment. But at the same time, they must be able to fall apart when they enter the cell, releasing the RNA inside. A carefully orchestrated set of structural changes occur as the virus attaches to the surface of the cell and is drawn inside, allowing the virus to deliver its RNA into the unwitting host.

Italian Firefly

Sat, 31 Mar 2007 18:16:32 +0000

Bioluminescence is the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy. The name originates from the Greek bios for "living" and the Latin lumen "light". Bioluminescence may be generated by symbiotic organisms carried within a larger organism. It is generated by an enzyme-catalyzed chemoluminescence reaction, wherein the pigment luciferin is oxidised by the enzyme luciferase. Adenosine triphosphate (ATP) is involved in most instances. The chemical reaction can occur either within or outside of the cell. In bacteria, the expression of genes related to bioluminescence is controlled by an operon called the lux operon.
Bioluminescence is a form of luminescence, or "cold light" emission; less than 20% of the light generates thermal radiation. It should not be confused with fluorescence, phosphorescence or refraction of light.

Crack&Cocaine

Sat, 24 Mar 2007 13:54:27 +0000

Cocaine (or crack in its impure freebase form) is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. It is a stimulant of the central nervous system and an appetite suppressant, giving rise to what has been described as a euphoric sense of happiness and increased energy.
The name comes from the name of the coca plant in addition to the alkaloid suffix -ine, forming Cocaine.

The stimulating qualities of the coca leaf were known to the ancient peoples of Peru and other pre-Columbian Andean societies. In modern Western countries, cocaine has been a feature of the counterculture for over a century. There is a long list of prominent intellectuals, artists, and musicians who have used the drug

A blunt a day keeps the doctor away

Sat, 24 Mar 2007 13:45:44 +0000

Cannabis is an annual flowering herb. It is a dicot. The leaves are palmately compound, with serrate leaflets. During the vegetative phase of growth, there is one leaflet on the first true leaf, three leaflets on the second, five on the third, and so on, up to about seven for C. sativa subsp. indica, and eleven for C. sativa subsp. sativa. In the reproductive phase, the number of leaflets per leaf reduces to a single leaflet, and ultimately none at the terminal bud. Leaf arrangement is opposite in the vegetative phase, and alternate in the reproductive phase.

Valium Detoxifiaction

Sat, 24 Mar 2007 13:37:11 +0000

The molecule shown here is CYP3A4 (PDB entries 1w0e and 2j0d), the cytochrome p450 that plays the major role in drug detoxification in your body. It has been estimated that this enzyme acts on about half of known drugs. For instance, it modifies the antibiotic erythromycin, shown at the bottom in blue. It also detoxifies such diverse drugs as codeine, diazepam (Valium), paclitaxel (Taxol), and several anti-HIV drugs.

In some cases, however, the reaction performed by cytochrome p450 enzymes can cause more harm than good. For example, CYP3A4 is partially responsible for the toxicity of large doses of acetaminophen (Tylenol). The modified form of acetaminophen is dangerously reactive, but it is normally cleared away quickly by other detoxifying enzymes. But with large doses, the reactive intermediate can build up to dangerous levels.

Prescriptions and p450
Doctors must be careful to keep the cytochrome p450 enzymes in mind when they prescribe medications. For instance, you may have seen warnings on prescriptions, telling you not to drink grapefruit juice when taking a medication. Grapefruits contain a flavinol molecule that inhibits cytochrome p450 enzymes. This will slow down the detoxification of drugs, which may cause them to have stronger effects than expected by the doctor.

C.S.I. : D.N.A.

Sat, 24 Mar 2007 13:31:21 +0000

DNA is also one of the most familiar molecules, the central icon of molecular biology, easily recognized by everyone. To some, it may carry a negative connotation, being a pervasive symbol for activists against genetically engineered produce. To others, it may bring to mind advances in forensics such as the DNA fingerprinting used in many recent high-profile trials. Some may have seen it in science fiction, modified to build dinosaurs or store cryptic messages from aliens. To all it is a pervasive symbol of our growing understanding of the human body and our close kinship with the rest of the biosphere, and the moral and ethical issues that must be addressed in the face of that knowledge.
DNA is perfect for the storage and readout of information. It is laden with information. Every surface and edge of the molecule carries information. The basic mechanism by which DNA stores and transmits genetic information was discovered in the 1950's by Watson and Crick. This basic information is stored in the way that the bases match one another on opposite sides of the double helix--adenine with thymine, guanine with cytosine--forming a set of complementary hydrogen bonds

How color vision works

Sat, 24 Mar 2007 13:23:15 +0000

rhodopsin also known visual purple expressed vertebrate photoreceptor cells pigment retina that responsible both formation photoreceptor cells first events perception light rhodopsins belong class protein coupled receptors chemical that allows night vision extremely sensitive light exposed white light pigment immediately bleaches takes about minutes regenerate fully humans rhodopsin consists building blocks opsin protein called scotopsin reversibly covalently bound cofactor retinal retinaldehyde structure rhodopsin consists bundle seven transmembrane helices that surround photoreactive chromophore retinal retinal chromophore portion rhodopsin made retina from vitamin isomerization retinal into trans retinal light induces conformational change opsin that activates associated protein triggers second messenger cascade rhodopsin rods most strongly absorbs green blue light therefore appears reddish purple which also called visual purple responsible monochromatic vision dark bovine rhodopsinseveral closely related opsins photopsins exist that differ only amino acids wavelengths light that they absorb most strongly these pigments found different types cone cells retina basis color vision humans have three different other opsins beside rhodopsin with absorption maxima yellowish green photopsin green photopsin bluish violet photopsin light some archaea express proton pump called bacteriorhodopsin carry photosynthesis like rhodopsin bacteriorhodopsin contains retinal seven transmembrane alpha helices however coupled protein similarly halorhodopsin light activated chloride pump finally alga known have opsin that contains monolithic light gated channel channelrhodopsin while bacteriorhodopsin halorhodopsin channelrhodopsin have significant sequence homology another sequences diverge from that vertebrate opsins therefore this evidence convergent evolution towards retinal binding seven transmembrane proteins efficaciously transduce light into cellular signaling normalised absorption spectra human rhodopsin dashed three photopsins edit external links wikimedia commons media related rhodopsinsphotoisomerization rhodopsin excellent animation rhodopsin excellent summary with pictures calculated spatial positions rhodopsin like proteins membrane categories protein coupled receptors sensory receptors pigments integral membrane proteins opsins group light sensitive membrane bound protein coupled receptors found photoreceptor cells retina they involved vision mediating conversion photon light into electrochemical signal first step visual transduction cascade families opsins generally recognized different spatial expression evolutionary histories rhodopsins which used night vision high sensitivity acuity opsins found photoreceptor cells cone opsins employed color vision sensitivity high acuity opsins located cone photoreceptor cells cone opsins further subdivided according their absorption maxima wavelength which highest light absorption observed evolutionary relationships deduced using amino acid sequence opsins also frequently used categorize cone opsins into their respective group both methods predict four general cone opsin groups addition rhodopsin rhodopsin expressed cells used night vision four cone opsins also knows photopsins expressed cone cells used color vision long

Blood clotting is a tricky business

Sat, 24 Mar 2007 13:16:40 +0000

This page is about the clotting of blood. For other meanings, please see coagulation (disambiguation).
The coagulation of blood is a complex process during which blood forms solid clots. It is an important part of hemostasis (the cessation of blood loss from a damaged vessel) whereby a damaged blood vessel wall is covered by a fibrin clot to stop hemorrhage and aid repair of the damaged vessel. Disorders in coagulation can lead to increased hemorrhage and/or thrombosis and embolism.

Coagulation is similar in mammals, with all mammals using a combined cellular and serine protease mechanism. The system in humans is the most extensively researched and therefore the best known. This article focuses on human blood coagulation

In a normal individual, coagulation is initiated within 20 seconds after an injury occurs to the blood vessel damaging the endothelial cells. Platelets immediately form a haemostatic plug at the site of injury. This is called primary haemostasis. Secondary haemostasis then follows—plasma components called coagulation factors respond (in a complex cascade) to form fibrin strands which strengthen the platelet plug. Contrary to popular belief, coagulation from a cut on the skin is not initiated by air or drying out, but by platelets adhering to and activated by collagen in the blood vessel endothelium. The activated platelets then release the contents of their granules, these contain a variety of substances that stimulate further platelet activation and enhance the haemostatic process.

Hemoglobin is the key

Sat, 24 Mar 2007 13:09:27 +0000

The genes for the protein chains of hemoglobin show small differences within different human populations, so the amino acid sequence of hemoglobin is slightly different from person to person. In most cases the changes do not affect protein function and are often not even noticed. However, in some cases these different amino acids lead to major structural changes. One such example is that of the sickle cell hemoglobin, where glutamate 6 in the beta chain is mutated to valine. This change allows the deoxygenated form of the hemoglobin to stick to each other, as seen in PDB entry 2hbs, producing stiff fibers of hemoglobin inside red blood cells. This in turn deforms the red blood cell, which is normally a smooth disk shape, into a C or sickle shape. The distorted cells are fragile and often rupture, leading to loss of hemoglobin. This may seem like a uniformly terrible thing, but in one circumstance, it is actually an advantage. The parasites that cause the tropical disease malaria, which spend part of their life cycle inside red blood cells, cannot live in the fiber-filled sickle cells. Thus people with sickle cell hemoglobin are somewhat resistant to malaria. Other circumstances leading to troubled hemoglobins arise from a mismatch in the production of the alpha and beta proteins. The structure requires equal production of both proteins. If one of these proteins is missing, it leads to conditions called Thalassemia.

You can look at the binding of oxygen up close in two structures of human hemoglobin. PDB entry 2hhb shows hemoglobin with no oxygen bound. In this picture, the heme is seen edge-on with the iron atom colored in gold. You can see the key histidine reaching up on the bottom side to bind to the iron atom. In PDB entry 1hho, oxygen has bound to the iron, pulling it upwards. This in turn, pulls on the histidine below, which then shifts the location of the entire protein chain. These changes are transmitted throughout the protein, ultimately causing the big shift in shape that changes the binding strength of the neighboring sites.

Coóól Laser Ball

Tue, 27 Feb 2007 19:52:31 +0000

special effects multicolor laser ball

Sex hormones

Mon, 26 Feb 2007 18:21:02 +0000

Our bodies grow in two major spurts during our lives. You probably don't remember the first, which occurred during the first few months of your life as you grew from a single cell into a fully formed baby. On the other hand, you probably have many memories (or you may be making those memories now) of your second frenzy of growth. During puberty, sex hormones direct selected tissues to undergo a second wave of growth and development. In women, estrogen hormones are largely responsible for coordinating these changes. Estrogens are made in the ovaries and then delivered within seconds throughout the body in the blood, directing the growth from child to adult.
Straight to the Source
Estrogens are small, carbon-rich molecules built from cholesterol. This is quite different than larger hormones, such as insulin and growth hormone, which are sensed by receptors on the cell surface. Estrogens pass directly into cells throughout the body, so the cell can use receptors that are in the nucleus, right at the site of action on the DNA. When estrogen enters the nucleus, it binds to the estrogen receptor, causing it to pair up and form a dimer. This dimer then binds to several dozen specific sites in the DNA, strategically placed next to the genes that need to be activated. Then, the DNA-bound receptor activates the DNA-reading machinery and starts the production of messenger RNA.
A Large Family
When researchers looked into the human genome, they found over 150 proteins that are similar to the estrogen receptor. This is a large family of nuclear receptors that sense the levels of small hormones and other signaling molecules, such as steroid and thyroid hormones, vitamin D, and retinoic acid.
Estrogens are used as part of some oral contraceptives and also in estrogen replacement therapy of postmenopausal women.

The Cholera Toxin

Mon, 26 Feb 2007 11:44:24 +0000

Cholera Toxin in Action
The catalytic portion of cholera toxin performs a single function: it seeks out the G proteins used for cellular signaling and attaches an ADP molecule to them (for more on G-proteins, see the Molecule of the Month for March 2004 ). This converts the G-protein into a permanently active state, so it sends a never-ending signal. This confuses the cell, and among other things, it begins to transport lots of water and sodium outwards. This floods the intestine, leading to life-threatening dehydration.

The two-part strategy employed by cholera toxin is highly effective, so much so that it is used by many different organisms that seek to protect themselves. A few examples from the PDB are shown here, with the targeting portion in blue and the toxic enzyme in red. These include E. coli enterotoxin (PDB entry 1ltb), which looks and acts like cholera toxin and is a cause of intestinal problems when traveling. Pertussis toxin (PDB entry 1prt), made by the bacterium that causes whooping cough, also attacks the G-protein signaling pathway. Diphtheria toxin (PDB entry 1mdt) is synthesized as a single chain, but is then cut to form the two-part toxin when it is released. It shuts down protein synthesis in cells by attacking one of the elongation factors. Ricin (PDB entry 2aai) is a powerful toxin made by the castor bean plant. Once it gets inside cells, it blocks protein synthesis by directly attacking ribosomes. For more information on toxins from a genomics perspective, take a look at the Protein of the Month at the European Bioinformatics Institute.

How Viagra Works

Mon, 26 Feb 2007 11:32:07 +0000

Viagra is available as blue pills with a characteristic shapeEven though sildenafil is only available by prescription from a doctor, it was advertised directly to consumers on US TV (famously being endorsed by Bob Dole and Football star Pele). Numerous sites on the Internet offer Viagra for sale after an "online consultation", a mere web questionnaire. The "Viagra" name has become so well known that many fake aphrodisiacs now call themselves "herbal Viagra" or are presented as blue tablets imitating the shape and colour of Pfizer's product. Viagra is also informally known as "Vitamin V", "the Blue Pill", as well as various other nicknames.