The Bill Clinton Neuron And The Sweat Neuron

Written by Abraham Thomas

Inrepparttar world of science, there is excited speculation about recent discoveries of individual neurons inrepparttar 144965 brain, with striking capabilities. They had discovered a neuron, which fired on recognition of just one special face. Scientists spotted this using microelectrodes, which could identifyrepparttar 144966 firing of a single neuron. Buried deep inrepparttar 144967 amygdala of a female patient, they discoveredrepparttar 144968 so-called “Bill Clinton” neuron. The cell fired on recognizing three very different images ofrepparttar 144969 former President; a line drawing of a laughing Clinton; a formal painting depicting him; and a photograph of him in a crowd. The cell remained mute whenrepparttar 144970 patient viewed images of other politicians and celebrities. In other patients, scientists found similar cells that responded selectively to actors, including Jennifer Anniston, Brad Pitt, and Halle Berry.

Most neuroscientists had believed that specific nerve cells handled individual pixels as on a television screen. Suddenly, a single neuron could identify Clinton. Could there be a “thinking neuron?” Scientists felt it impossible for an individual cell to be clever enough to make sense of a concept as subtle as Clinton. Evenrepparttar 144971 world’s fastest supercomputers would have difficulty performing that pattern-recognition feat. So, how could a single neuron ever learn to recognize a President? Such speculation onrepparttar 144972 nature of neurons continued ceaselessly in scientific circles. This was surprising. How could scientists remain blind torepparttar 144973 significance ofrepparttar 144974 Nobel Prize awarded in 2004 to Lynda Buck forrepparttar 144975 discovery ofrepparttar 144976 recognition processes inrepparttar 144977 olfactory system?

There, Buck had already reported a “Sweat” neuron and an “Orange” neuron. Those experiments concernedrepparttar 144978 recognition of smells. She reported that octanol smelled like oranges and octanoic acid, like sweat, even though their chemical structures were similar. Yet, different neurons fired for each smell. Was this just more evidence of thinking neurons? Yet, Buck had a simple explanation. The olfactory system recognized different combinations of firing for different odors. First, a single receptor recognized multiple odorants. Second, a single odorant was recognized by multiple receptors. And third, different odorants were recognized by different combinations of receptors. It was this combinatorial coding system, which enabledrepparttar 144979 olfactory system to recognize millions of odors. So, there were Sweat neurons, Rose neurons and Orange neurons. And millions more. Could it be that Clinton and Berry neurons were no different?

Diamonds Are Forever

Written by Charmain Stought

Diamonds are still a girl's best friend, right? We loverepparttar shiny gems. They arerepparttar 144723 most popular rocks sold today. But what exactly are they, anyway? Where do they come from? What else are they used for?

Diamonds are a mineral in one ofrepparttar 144724 two crystalline forms ofrepparttar 144725 element carbon. They arerepparttar 144726 hardest natural substance man knows. Diamonds are sold as gems, and used in industrial applications for smoothing, cutting, and polishing hard materials.

Diamonds are most famous for crystallizing inrepparttar 144727 common colorless form. They may also be tranlucent to transparent white, yellow, green, blue, or brown. Diamonds have a high refractive index which is why they are so brilliant and sparkly after cutting. The familiar shape ofrepparttar 144728 diamond isrepparttar 144729 octahedron.

The most brilliant diamonds become gemstones for jewelry and other uses. For those that don't make it to gems, there are other options. There is bort, which is a more poorly crystallized or undesirable color and in fragmentary condition, and carbonados which is gray to black opaque. Bort and carbonados are used as abrasives forrepparttar 144730 cutting of diamonds andrepparttar 144731 cutting heads of industrial rock drills.

Diamonds are found in alluvial formations and in volcanic pipes, filled for most of their length with blue ground or kimberlite, and igneous rock consisting primarily of serpentine. Diamond yielding earth is mined by bothrepparttar 144732 open-pit method and by underground mining. After removal torepparttar 144733 surface,repparttar 144734 soil is crushed and concentrated. Passingrepparttar 144735 concentrated material in a stream of water over greased tables doesrepparttar 144736 needed sorting. The diamond is largely water repellent and sticks torepparttar 144737 grease andrepparttar 144738 other minerals retain a film of water, which preventsrepparttar 144739 sticking torepparttar 144740 grease. Thenrepparttar 144741 diamonds are removed fromrepparttar 144742 grease, cleaned, and graded for sale and use.

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