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Scientists are trying to control the weather with strong lasers to create clouds, rain and trigger lightning

Scientists are trying to control the weather with strong lasers to create clouds, rain and trigger lightning | All about Science. | Scoop.it

Experts from around the world are to gather at the World Meteorological Organisation next month to discuss how powerful laser pulses can be used to generate changes in the atmosphere that influence the weather.

 

Their experiments have shown that intense pulses of light can cause ice to form and water to condense, leading to the formation of clouds.

 

The scientists have now begun testing their equipment outside for the first time with extremely short pulses of laser light were fired into the sky.

 

Researchers have also proved that lightning discharges can be triggered and channelled through the air using laser pulses. They hope the technology could allow lightning during thunderstorms to be guided away from sensitive buildings such as power plants or airports. 

 

It could also be used to manipulate the weather by creating clouds and triggering rainfall ahead of major public events.

 

Professor Jean-Pierre Wolf and Dr Jerome Kasparian, both biophotonics experts at the University of Geneva, have now organized a conference at the WMO next month in an attempt to find ways of speeding up research on the topic. They said: “Ultra-short lasers launched into the atmosphere have emerged as a promising prospective tool for weather modulation and climate studies.


Via Dr. Stefan Gruenwald
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Geologists, professors want natural history museum for ' orphan collections' - Times of India

Geologists, professors want natural history museum for ' orphan collections' - Times of India | All about Science. | Scoop.it
Geologists, professors want natural history museum for ' orphan collections' Times of India There is therefore, a concerted effort to evolve a plan to preserve them and then put it up before the department of science and technology for integrating...
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New book explores evolution of human reproduction | UChicago News

New book explores evolution of human reproduction | UChicago News | All about Science. | Scoop.it
This is just one of the hundreds of surprising pieces of information that readers will glean from the far-reaching and fascinating How We Do It: The Evolution and Future of Human Reproduction, a new book by Robert Martin, ...
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Transmission of REV viruses from mammals to birds was probably an unexpected consequence of medical research

Transmission of REV viruses from mammals to birds was probably an unexpected consequence of medical research | All about Science. | Scoop.it

A report published today (August 27) in PLOS Biology tells the surprising story of reticuloendotheliosis virus (REV) evolution and how, in the 1930s, unwitting malaria researchers were most likely responsible for transmitting REV from mammals to birds. The report highlights the importance of modern-day virus monitoring to limit potentially adverse transmission effects.

 

“It’s a very interesting story. That malarial research could have led to zoonosis from mammal to bird is pretty surprising,” said Eric Delwart, a professor of laboratory medicine at the University of California, San Francisco, who was not involved in the research. “It’s basically an example of a contamination that went rogue . . . and extraordinary bad luck.”

 

Retroviruses integrate into genomic DNA of host cells to borrow the cells’ transcription machinery and replicate. On occasion, such integration events happen in germline cells—such as sperm and eggs—and can thus be passed on to offspring, forever changing the host genome. Scientists like Robert Gifford, a professor at the Aaron Diamond AIDS Research Center in New York City, examine these integrated viral sequences—or viral fossils—in animals’ genomes to investigate the evolutionary history of viruses.

 

While studying the viral fossils of Madagascan mammals, Gifford made a surprising discovery. “We turned up this sequence in the ring-tailed mongoose genome that was very closely related to REV,” he said.

 

REV is a retrovirus that infects poultry and wild game birds, causing an array of disease symptoms, including anemia, immunosuppression, and the production of runts. Evidence from genome sequencing studies had suggested that it originated in mammals, but most sequence similarities mapped only to fragments of REV. Because of these fragmented similarities, “I had always assumed, as had probably other virologists, that these viruses had been circulating in birds for a long time,” said John Coffin, a professor of molecular biology and microbiology at Tufts University in Boston, who also was not involved in the work.

 

The copies of REV fossils Gifford found in two species of mongoose, however, showed full length similarity to bird REVs. “It made us curious because it is very unusual to have an avian retrovirus be so closely related to a mammalian retrovirus,” he said. “It suggested that there had been a transmission quite recently.” Indeed, the exchange turned out to have occurred less than a century ago.

 

After finding the REV sequences in mongoose, and a paper desribing a full-length REV in the egg-laying mammal echidna, Gifford analyzed the genomes of another 42 mammalian species, again finding nothing but REV fragments. He then analyzed the sequences of all known REVs isolated from birds to determine which were most similar to the mongoose and echidna REVs, and therefore, which species was likely to have been infected first.

 

The most similar bird REVs were two that had been isolated separately from ducks—one in 1959, the other in 1972.  Importantly, the source of REV infection in these animals was deemed to be contaminated stocks of Plasmodium lophurae—a malarial parasite. In fact, evidence of a then-unknown infectious agent contaminating stocks of P. Iophurae had surfaced as early as 1941.

 

Continuing the historical detective work, Gifford discovered that P. lophurae had been isolated just once, in 1937, from a Bornean Crested Firebacked pheasant at the New York Zoological Park (now the Bronx Zoo). Researchers planned to use this bird parasite as a model for studying human malaria, and after isolating it from pheasant, they had passaged the parasite in chickens for mass production.


Via Dr. Stefan Gruenwald
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Bernhard H. Schmitz's comment, September 2, 2013 5:15 AM
Right!
Juan Carlos Cañadilla's comment, September 2, 2013 7:55 AM
Yes!
Mel Melendrez-Vallard's comment, September 2, 2013 9:06 AM
I liked the article and I agree it did get people thinking...one of many possible thoughts on the subject.
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UP Diliman graduates top geologist board exams - ABS CBN News

UP Diliman graduates top geologist board exams - ABS CBN News | All about Science. | Scoop.it
UP Diliman graduates top geologist board exams
ABS CBN News
The Professional Regulation Commission (PRC) announced Wednesday that 109 out of 195 passed the Geologist Licensure Examination given by the Board of Geology in Manila in August 2013.
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Lowest Temperature At Which Life Forms Can Live and Grow Pinpointed

Lowest Temperature At Which Life Forms Can Live and Grow Pinpointed | All about Science. | Scoop.it

The study, published inPLoS One, reveals that below -20°C, single-celled organisms dehydrate, sending them into a vitrified – glass-like – state during which they are unable to complete their life cycle.

 

The researchers propose that, since the organisms cannot reproduce below this temperature, -20°C is the lowest temperature limit for life on Earth.

 

Scientists placed single-celled organisms in a watery medium, and lowered the temperature. As the temperature fell, the medium started to turn into ice and as the ice crystals grew, the water inside the organisms seeped out to form more ice. This left the cells first dehydrated, and then vitrified. Once a cell has vitrified, scientists no longer consider it living as it cannot reproduce, but cells can be brought back to life when temperatures rise again. This vitrification phase is similar to the state plant seeds enter when they dry out.

 

'The interesting thing about vitrification is that in general a cell will survive, where it wouldn't survive freezing, if you freeze internally you die. But if you can do a controlled vitrification you can survive,' says Professor Andrew Clarke of NERC's British Antarctic Survey , lead author of the study. 'Once a cell is vitrified it can continue to survive right down to incredibly low temperatures. It just can't do much until it warms up.'

 

More complex organisms are able to survive at lower temperatures because they are able to control the medium the cells sit in to some extent.

'Bacteria, unicellular algae and unicellular fungi – of which there are a huge amount in the world-are free-living because they don't rely on other organisms ,' Clarke explains.

 

'Everything else, like trees and animals and insects, has the ability to control the fluid that surrounds their internal cells. In our case it's blood and lymph. In a complicated organism the cells sit in an environment that the organism can control. Free-living organisms don't have this; if ice forms in the environment they are subject to all the stresses that implies.'

 

If a free-living cell cools too quickly it would be unable to dehydrate and vitrify; instead it would freeze and wouldn't survive.

 

This goes some way towards explaining why preserving food using deep freezing works. Most fridge freezers operate at a temperature of nearly -20°C . This study shows that this temperature works because moulds and bacteria are unable to multiply and spoil food.

 

'We were really pleased that we had a result which had a wider relevance, as it provided a mechanism for why domestic freezers are as successful as they are,' Clarke says.

 

The scientists believe that the temperature limit they have discovered is universal, and below -20°C simple forms of unicellular life can't grow on Earth. During the study they looked at a wide range of single-celled organisms that use a variety of different energy sources, from light to minerals, to metabolise. Every single type vitrified below this temperature.

 


Via Dr. Stefan Gruenwald
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Steve Marek's curator insight, September 4, 2013 1:17 PM

A -20 freezer is good.  A -80 is better.

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August 27, 1883: Krakatoa | History of Geology, Scientific American Blog Network

August 27, 1883: Krakatoa | History of Geology, Scientific American Blog Network | All about Science. | Scoop.it
August 27, 1883: Krakatoa. The day the world exploded. #volcano http://t.co/jU8QTlSOFr
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