The Bill Clinton Neuron And The Sweat NeuronWritten by Abraham Thomas
In world of science, there is excited speculation about recent discoveries of individual neurons in 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 identify firing of a single neuron. Buried deep in amygdala of a female patient, they discovered so-called “Bill Clinton” neuron. The cell fired on recognizing three very different images of 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 when 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. Even 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 on nature of neurons continued ceaselessly in scientific circles. This was surprising. How could scientists remain blind to significance of Nobel Prize awarded in 2004 to Lynda Buck for discovery of recognition processes in olfactory system?
There, Buck had already reported a “Sweat” neuron and an “Orange” neuron. Those experiments concerned 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 enabled 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 ForeverWritten by Charmain Stought
Diamonds are still a girl's best friend, right? We love shiny gems. They are 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 of two crystalline forms of element carbon. They are 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 in 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 of diamond is 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 for cutting of diamonds and 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 both open-pit method and by underground mining. After removal to surface, soil is crushed and concentrated. Passing concentrated material in a stream of water over greased tables does needed sorting. The diamond is largely water repellent and sticks to grease and other minerals retain a film of water, which prevents sticking to grease. Then diamonds are removed from grease, cleaned, and graded for sale and use.