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Posts Tagged ‘Science & Tech’

Giant Yummy Eggs Killed Off the Elephant Bird

19 Dec


Photo: De Agostini Picture Library/BBC

Scientists have put forth various theories to explain the extinction of the giant Elephant Bird, the largest bird to ever live on Earth, including climate change and hunting by humans. The truth, it turns out, can be summed up in two words: yummy eggs.

Sir David Attenborough explains:

Recent archaeological evidence has revealed the fragments of elephant bird egg shells among the remains of human fires, suggesting that the eggs, which are 180 times bigger than a chicken egg, regularly provided food for entire families.

Sir David says: "I doubt it was hunted to extinction – anyone who has seen an ostrich in a zoo knows that it has a kick which can open a man’s stomach and an enraged elephant bird, many times the size of an ostrich, must have been a truly formidable opponent.
"I suspect it was its egg. They may not have been able to tackle an adult bird, but they could have taken its eggs which would have been a huge source of food.
"Even if the bird itself was held in awe or fear by the people here, it’s unlikely the eggs were – and that would have meant the gradual disappearance of this unique giant."

Link

 
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Mice Prefer Treats They Worked Harder to Get

03 Nov

In an article in The Proceedings of the Royal Society, two researchers described how mice in an experiment tended to get greater enjoyment out of rewards that were more labor-intensive:

Mice were trained to push levers to get either of two rewards. Press one lever, out comes a drop of sugar water. Press the other and they get a drop of different tasting sugar water.

Then things got interesting. For one of the treats, scientists gradually increased the amount of effort required for the payoff—from one lever-press to five, then 10, then 15. So by the end of the session, one type of sugar water cost 15 times more effort than the other.

The mice then retired to their home cage where both treats were freely available. And they showed a strong preference for whichever reward they’d worked harder to obtain. Based on how fast the mice sipped, they appeared to find the costlier sugar water more tasty.

Link | Photo by Flickr user Steve Berger Photography used under Creative Commons license

 
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Bandages That Change Color when a Wound Is Infected

03 Nov

Scientists at the Fraunhofer Research Institution in Munich, Germany, have placed pH sensitive dyes in bandages. These change color when they come into contact with fluids that indicate that a wound is infected:

In creating the color control strip, the researchers had to ensure the dye remained chemically stable when bonded to the fibers of the dressing material or the plaster to ensure it doesn’t get into the wound. They also had to ensure the indicator showed a clear change in color and reacted sensitively in the right pH range.

The researchers have already produced a prototype of the dressing and they say initial tests have proved successful. They are now looking to take the idea further with plans to integrate optical sensor modules into the dressing to measure the pH value and indicate the results on a reader unit. This would allow the pH value to be read off precisely, providing information about how the wound is healing.

Link via Geekosystem | Photo: Fraunhofer EMFT

 
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Is a Cure for the Common Cold in the Future?

02 Nov

Until very recently, biologists believed that once a virus enters a cell, a person’s immune system cannot combat that virus because antibodies cannot enter cells. But researchers at the Laboratory of Molecular Biology in Cambridge, UK, have uncovered evidence that antibodies can, in fact, enter cells. This opens up the possibility of attaching antiviral components to antibodies that can kill viruses inside cells:

Once inside the cell, the presence of the antibody is recognised by a naturally occurring protein in the cell called TRIM21 which in turn activates a powerful virus-crushing machinery that can eliminate the virus within two hours – long before it has the chance to hijack the cell to start making its own viral proteins. “This is the last opportunity a cell gets because after that it gets infected and there is nothing else the body can do but kill the cell,” Dr James said.

“The antibody is attached to the virus and when the virus gets sucked inside the cell, the antibody stays attached, there is nothing in that process to make the antibody to fall off.

“The great thing about it is that there shouldn’t be anything attached to antibodies in the cell, so that anything that is attached to the antibody is recognised as foreign and destroyed.”

Leo James, the lead researcher, speculated that this discovery could lead to effective treatments for cold viruses, among others.

Link via DVICE | Image: Clipart.com

 
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Valley of the Whales

08 Aug

Paleontologist Philip Gingerich looks for sea monsters in the Egyptian desert. He assembles fossils of ancient whales that died there when it was covered by an ocean. One such whale is the Basilosaurus, which had small hind legs.

“Complete specimens like that Basilosaurus are Rosetta stones,” Gingerich told me as we drove back to his field camp. “They tell us vastly more about how the animal lived than fragmentary remains.”

Wadi Hitan—literally “valley of whales”—has proved phenomenally rich in such Rosetta stones. Over the past 27 years Gingerich and his colleagues have located the remains of more than a thousand whales here, and countless more are left to be discovered.

Researchers hope that whale fossils can help them understand how a land mammal evolved into an aquatic form that became our modern whales. Link

(Image credit: Richard Barnes/National Geographic)

 
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Scientists Measure Shortest Interval of Time Ever

29 Jul

German scientists hit electrons with light and then measured how they soon they moved. The delay between the bombardment and the movement of those electrons is the shortest interval of time ever measured, which is 20 attoseconds. An attosecond is one quintillionth of a second.

When light is absorbed by atoms, the electrons become excited. If the light particles, so-called photons, carry sufficient energy, the electrons can be ejected from the atom. This effect is known as photoemission and was explained by Einstein more than hundred years ago. Until now, it has been assumed that the electron start moving out of the atom immediately after the impact of the photon. This point in time can be detected and has so far been considered as coincident with the arrival time of the light pulse, i.e. with “time zero” in the interaction of light with matter.

The scientists tested the assumption, and this is what happened:

Their measurements revealed that electrons from different atomic orbitals, although excited simultaneously, leave the atom with a small but measurable time delay of about twenty attoseconds.

In the comments, provide practical illustrations of the shortest intervals of time.

Link via Popular Science | Photo: Thorsten Naeser / Max-Planck-Institute of Quantum Optics

 
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Is Our Electrical Grid Dying?

09 Jul


The Vincent substation along California’s State Route 14 is crucial to bringing wind and solar power to the Los Angeles Basin. Photo: Joe McNally

If you think about it, it’s a marvel of modern engineering that most of us aren’t even aware of "The Grid". Yet it is what made modern life possible. When you watch TV, work on the computer, or even turn the light on, you’re using the electricity and that juice comes to your house via the electrical grid.

"The electrical grid is still basically 1960s technology," says physicist Phillip F. Schewe, author of The Grid. "The Internet has passed it by. The meter on the side of your house is 1920s technology." Sometimes that quaintness becomes a problem. On the grid these days, things can go bad very fast.

When you flip a light switch, the electricity that zips into the bulb was created just a fraction of a second earlier, many miles away. Where it was made, you can’t know, because hundreds of power plants spread over many states are all pouring their output into the same communal grid. Electricity can’t be stored on a large scale with today’s technology; it has to be used instantly. At each instant there has to be a precise balance between generation and demand over the whole grid. In control rooms around the grid, engineers constantly monitor the flow of electricity, trying to keep voltage and frequency steady and to avoid surges that could damage both their customers’ equipment and their own.

When I flip a switch at my house in Washington, D.C., I’m dipping into a giant pool of electricity called the PJM Interconnection. PJM is one of several regional operators that make up the Eastern grid; it covers the District of Colum bia and 13 states, from the Mississippi River east to New Jersey and all the way down to the Outer Banks of North Carolina. It’s an electricity market that keeps supply and demand almost perfectly matched—every day, every minute, every fraction of a second—among hundreds of producers and distributors and 51 million people, via 56,350 miles of high-voltage transmission lines.

So it should worry you that the grid is sick. America’s electrical grid infrastructure is a patchwork of networks built with antiquated equipments. Over decades, this infrastructure has fallen behind the nation’s ever-growing demand for electricity. So, how do we fix it? (And for those of you who shout "no more oil" should know that our "addiction" to foreign oil has nothing to do with electricity – oil is predominantly used for transportation, not electricity).

Joel Achenbach of National Geographic wrote a fascinating article about the Electrical Grid (with fantastic photos by Joe McNally): Link – Thanks Marilyn!

 
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