swirls and twirls on your palms and fingers
Posted: Sun May 03, 2009 8:33 am
SCI-TECH
Comment: Arches, loops and whorls
By Moody
Sunday, 03 May, 2009 | 06:25 PM PST |
You must have done it before many a time, but there is no harm in doing it once more. Look at your fingertips and run your eyes downward through the palm. As soon as it hits the wrist, you can see the change in skin pattern. The arches, loops and whorls are all gone. Just in case they haven’t, immediately get in touch with the management of the Guinness Book of World Records for you would be the first person on earth to have a palm-like skin on any other part of the body!
You have always known that the swirls and twirls on your palms and fingers are specific to those areas. But any idea why? The chances are that you don’t and in that case you deserve a pat on the back for you qualify to be a scientist because the scientists themselves don’t know for sure why it is what it is!!
Inanities aside, fingerprints have always been strange to scientists. In fact, the palms of the hands are mysteriously different from the rest of the body in several ways. Not only are there fingerprints on the palm and not on other places of the skin, but the skin is also the thickest on the palm, there are more sweat glands and there are no hair follicles. Michael Kucken and Alan Newell of the University of Arizona guess that the same process might be responsible for the formation of brain grooves as well as certain structures in the human eye. Who knows?
Scientifically monitored observations suggest that by the 17th week of pregnancy, the fingerprints of a foetus are set in stone. The uniqueness of fingerprints has been recognised for some two millennia and studied by scientists for over two centuries. But researchers have not been able to explain how they form.
According to a new theoretical computer model, the process most likely begins in the 10th week of gestation, when a foetus is about 80 millimeters long. Writing in the journal Europhysics Letters, Kücken and Newell made out a case that is plausible though not assured. The creation of the patterns, according to them, involves stresses in a sandwiched sheet of skin called the basal layer. In a foetus, the basal layer grows faster than surrounding layers. The basal layer buckles and folds in several directions, forcing complex shapes.
Stresses are created at skin boundaries, including fingernails and knuckle creases, as well as around shrinking fingertip pads. These folds encode the future fingerprint pattern that becomes visible on the skin surface in subsequent weeks. And because the fingerprint pattern is coded underneath the skin surface, it cannot be destroyed by superficial skin injuries.
As is the wont of true scientists, as against those of the pseudo variety, the two readily conceded that they had no idea how exactly the pattern is preserved during the growth of the foetus inside the womb.
The research on the uniqueness and permanence of fingerprints incidentally goes back to the late 19th century. Sir Francis Galton classified fingerprints based on their patterns of arches, loops, and whorls. In 1901, England put into practice a criminal identification system based on Galton’s work. The classification method is still widely used today across the world.
Around the same time, fine-powder dusting was found useful in highlighting the relief pattern in an oily finger smudge — essentially allowing a record to be taken by a camera or lifted with an adhesive material. There have been other ways developed over the years for making prints more visible. All of these contrast-enhancement techniques require the addition of a substance of some sort, which can limit any subsequent analysis — DNA extraction, for instance — of the print.
It was in 1986 that DNA fingerprinting was introduced to track down criminals. Alec Jeffreys, a scientist at the University of Leicester, was studying DNA sequences for genetic markers associated with hereditary diseases when he was approached by the police for help in connecting a suspect to two murders. He realised that his technique of DNA fingerprinting could be successful in that regard and he was right. It did. A young baker with the funny name of Colin Pitchfork was sentenced to two life terms in prison for the murders.
What happens when law is dealing with two suspects who happen to be identical twins with matching DNA sequences? Come back next week.
moody.square@gmail.com
http://www.dawn.com/wps/wcm/connect/daw ... orls-ss-08
Copyright © 2009 - Dawn Media Group
Comment: Arches, loops and whorls
By Moody
Sunday, 03 May, 2009 | 06:25 PM PST |
You must have done it before many a time, but there is no harm in doing it once more. Look at your fingertips and run your eyes downward through the palm. As soon as it hits the wrist, you can see the change in skin pattern. The arches, loops and whorls are all gone. Just in case they haven’t, immediately get in touch with the management of the Guinness Book of World Records for you would be the first person on earth to have a palm-like skin on any other part of the body!
You have always known that the swirls and twirls on your palms and fingers are specific to those areas. But any idea why? The chances are that you don’t and in that case you deserve a pat on the back for you qualify to be a scientist because the scientists themselves don’t know for sure why it is what it is!!
Inanities aside, fingerprints have always been strange to scientists. In fact, the palms of the hands are mysteriously different from the rest of the body in several ways. Not only are there fingerprints on the palm and not on other places of the skin, but the skin is also the thickest on the palm, there are more sweat glands and there are no hair follicles. Michael Kucken and Alan Newell of the University of Arizona guess that the same process might be responsible for the formation of brain grooves as well as certain structures in the human eye. Who knows?
Scientifically monitored observations suggest that by the 17th week of pregnancy, the fingerprints of a foetus are set in stone. The uniqueness of fingerprints has been recognised for some two millennia and studied by scientists for over two centuries. But researchers have not been able to explain how they form.
According to a new theoretical computer model, the process most likely begins in the 10th week of gestation, when a foetus is about 80 millimeters long. Writing in the journal Europhysics Letters, Kücken and Newell made out a case that is plausible though not assured. The creation of the patterns, according to them, involves stresses in a sandwiched sheet of skin called the basal layer. In a foetus, the basal layer grows faster than surrounding layers. The basal layer buckles and folds in several directions, forcing complex shapes.
Stresses are created at skin boundaries, including fingernails and knuckle creases, as well as around shrinking fingertip pads. These folds encode the future fingerprint pattern that becomes visible on the skin surface in subsequent weeks. And because the fingerprint pattern is coded underneath the skin surface, it cannot be destroyed by superficial skin injuries.
As is the wont of true scientists, as against those of the pseudo variety, the two readily conceded that they had no idea how exactly the pattern is preserved during the growth of the foetus inside the womb.
The research on the uniqueness and permanence of fingerprints incidentally goes back to the late 19th century. Sir Francis Galton classified fingerprints based on their patterns of arches, loops, and whorls. In 1901, England put into practice a criminal identification system based on Galton’s work. The classification method is still widely used today across the world.
Around the same time, fine-powder dusting was found useful in highlighting the relief pattern in an oily finger smudge — essentially allowing a record to be taken by a camera or lifted with an adhesive material. There have been other ways developed over the years for making prints more visible. All of these contrast-enhancement techniques require the addition of a substance of some sort, which can limit any subsequent analysis — DNA extraction, for instance — of the print.
It was in 1986 that DNA fingerprinting was introduced to track down criminals. Alec Jeffreys, a scientist at the University of Leicester, was studying DNA sequences for genetic markers associated with hereditary diseases when he was approached by the police for help in connecting a suspect to two murders. He realised that his technique of DNA fingerprinting could be successful in that regard and he was right. It did. A young baker with the funny name of Colin Pitchfork was sentenced to two life terms in prison for the murders.
What happens when law is dealing with two suspects who happen to be identical twins with matching DNA sequences? Come back next week.
moody.square@gmail.com
http://www.dawn.com/wps/wcm/connect/daw ... orls-ss-08
Copyright © 2009 - Dawn Media Group