The laws of probability seems simple at first thought, but scratch the surface and their inner truth can be rather more counterintuitive. This video describes one of those situations—and the answer might prove more useful than you think. Read more…
Read More:
How Understanding Probability Could Save Your Life
A new study by Australian geologists has shown that over 80% the world’s commercial gold deposits were generated in a flash process, the result of depressurizing earthquakes that rapidly converted mineral-rich fluids into precious veins of gold. The process is called flash vaporization . Deep below the Earth’s crust, at depths ranging from three to 18 miles (5-30 km), fluid-filled fault cavities are subject to extreme temperatures and pressure. These fluids are rich in dissolved substances like gold and silicate minerals. But for those deposits located near fault lines, an earthquake can create a dramatic drop in pressure which forces the fluid to expand to as much as 130,000 times its former size — and in the blink of an eye. The researchers, a team consisting of Dion Weatherley and Richard Henley, found that this depressurization process causes trapped fluids to expand to a very low-density vapor. This ‘flash’ effect results in the rapid deposition of silica, along with gold-enriched quartz veins. From New Scientist : The fluid cannot get from the surrounding rock into the hole fast enough to fill the void, Henley says, so pressure drops from 3000 times atmospheric pressure to pressures almost the same as those at Earth’s surface in an instant. The nearby fluid flash-vaporises as a result – and any minerals it contains are deposited as it does. Later, incoming fluid dissolves some of the minerals, but the less-soluble ones, including gold, accumulate as more episodes of quake-driven flash deposition occur. “Large quantities of gold may be deposited in only a few hundred thousand years,” says Weatherley – a brief interval by geological standards. “Each event drops a little more gold,” adds Henley. “You can see it microscopically, tiny layer after tiny layer. It just builds up.” They calculate that large earthquakes can deposit as much as 0.1 milligrams of gold along each square meter of a fault zone’s surface in a fraction of a second. Eventually, over the course of many thousands of years, these deposits begin to accumulate. The researchers estimate, for example, that active faults can produce a 100-metric-ton deposit of gold in less than 100,000 years. Read the entire study at Nature Geoscience . More at Nature News and New Scientist . Image: Shutterstock/farbled.
Originally posted here:
Most gold deposits were produced by earthquakes
Earlier this month, doctors announced that a baby had been cured of an HIV infection . Now, using a similar technique, it appears that 14 adults have likewise been successfully treated for the disease. The trick, say the scientists, is to tackle the infection early. The research was conducted by Asier Sáez-Cirión of the Pasteur Institute and his results now appear in the open source journal PLOS Pathogens . His team analyzed 70 people with HIV who had been treated by combination antiretroviral therapy (cART) just a short time after infection, a range spanning 35 days to 10 weeks. This is much sooner than people are normally treated. And in fact, these patients, called the Visconti Cohort , were all diagnosed with HIV early (and by chance) when they turned up at hospitals to be assessed for other conditions. The cohort stuck to the antiretrovirals (ARVs) for an average of three years, during which time the drugs kept the virus in check (they do not eradicate HIV from the body). Eventually, all of the patients stopped taking the ARVs for various reasons (personal choice, different drug protocols, etc.). Normally, HIV will return when patients stop taking their ARVs. But this time, something interesting happened. The authors of the study described it this way: We identified 14 HIV patients (post-treatment controllers [PTCs]) whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. That’s roughly one in ten of the patients , a group that included four women and 10 men. On average, they were off the medication for seven years. It’s important to note that the patients still have the HIV infection. Also, they’re not ” supercontrollers ” (the
Read the original post:
First a baby, now 14 adults “functionally cured” of HIV