How whales evolved to dive in the sea

A new study has explained how marine mammals like seals and whales evolved to dive in the sea, and cope with the needs of a life in the aquatic environment.

An aquatic lifestyle imposes serious demands for the organism, and this is true even for the tiniest molecules that form our body.

When the ancestors of present marine mammals initiated their return to the oceans, their physiology had to adapt radically to the new medium.

Dr. Michael Berenbrink and his colleagues at Liverpool University, UK, have been studying how myoglobin, the molecule responsible for delivering oxygen to the muscles during locomotion, has been modified in seals and whales to help them cope with the needs of a life at sea.

The researchers have found evidence indicating that the net positive charge of this protein is increased in marine mammals compared with terrestrial relatives, and they have speculated that this may help improving the solubility of the molecule.

This is important as divers may contain 10 times more myoglobin in their muscles than terrestrial animals.

The team has also found a conspicuous increase of the amino acid histidine in the myoglobin of strong divers, which may allow the animal to deal better with the accumulation of lactic acid that is frequent during long dives.

In order to confirm that this was indeed the result of evolutionary pressure, they went on to study the molecular sequence of myoglobin in small aquatic mammals such as beavers, muskrats and water shrews, which only dive for considerably shorter periods of time, to see if they could also find evidence for the same trend.

Indeed, the net charge of the myoglobin molecule in aquatic rodents was twice as high compared to their strictly terrestrial relatives, and the trend was also verified for some semi-aquatic species of insectivores.

“This work will contribute to our understanding of protein solubility in general”, explained Dr. Berenbrink.

“It will also allow the analysis of natural selection on protein structure/function in multiple parallel cases in which a high muscle myogobin content evolved, such as in divers but also in burrowing animals that normally experience hypoxia,” he said.

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Sun leaves Earth wide open to cosmic rays

Washington, June 28: The sun, a star at the centre of the solar system, is known to provide ideal conditions for life to thrive on Earth. But, astronomers have claimed that it also leaves the planet wide open to harmful cosmic rays.

A joint team from University of Arizona and University of Texas in the US has found that the sun periodically leaves Earth open to assaults from interstellar nasties in a way that most stars do not.

The sun protects humans from cosmic rays and dust from beyond the solar system by enveloping in the heliosphere -- a bubble of solar wind that extends past Pluto. These rays would damage the ozone layer and interstellar dust can dim sunlight and trigger an ice age.

However, when the solar system passes through very dense gas and dust clouds, the heliosphere can shrink until its edge is inside Earth's orbit. So, in their research, the team, led by David Smith, has calculated the squeezing of various stars' protective "astrospheres".

The astronomers found Earth is exposed to between one and 10 interstellar assaults every billion years. Habitable planets around a red dwarf, which account for three of every four stars, are never exposed.

That's because they need to be close to these dim stars to be warm enough to be habitable, they said.

"The bottom line is that habitable planets around red dwarfs are better protected from climate catastrophes than Earth is," Smith of the University of Arizona in Tucson was quoted as saying.

The findings are to appear in 'Astrobiology' journal.

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Dinosaurs were actually "thin-osaurs"

London, June 27: Tyrannosaurus rex, the best-known predatory species, may have been far more lithe than previously thought, researchers have discovered.

In a new study, boffins have claimed that dinosaurs may have been much lighter and sleeker than earlier believed because of potential flaws in the equations used to calculate their weight.

"Palaeontologists have for 25 years used a statistical model to estimate the body weight of giant dinosaurs and other extraordinarily large extinct animals," said Gary Packard, from Colorado State University, whose research will appear in the Zoological Society of London's Journal of Zoology this week.

"We have found that the statistical model is seriously flawed and the giant dinosaurs probably were only about half as heavy as is generally believed," the expert added.

Up till now, dinosaurs have been shown as well-rounded, powerful animals, when they are more likely to have been skinny and muscular.

The new findings would suggest that these animals were leaner and faster, needed less food and had significant differences in lifestyle from what was previously thought.

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Mars may have a water table hidden underground

London, June 27: A new hypothesis has suggested that Mars may have a water table hidden underground, despite satellite data suggesting otherwise.

Today the small amount of water detected on the planet is locked in the polar ice caps, but recently discovered geological features suggest liquid water once flowed on its surface.

This could now be hiding beneath the rocky crust.

The European Space Agency’s Mars Express satellite has used ground-penetrating radar in some areas to look for a water table but found no evidence for one, despite research that concluded any water would be found within 9 kilometres of the surface, which is well within the reach of the probe’s instruments.

Planetary scientist Bill Farrell of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and colleagues say that scientists should not give up the search for the Martian water table just yet.

The satellite’s radar signal should bounce back from shiny surfaces like water.

But, the team calculates that if the layer of rock and icy soil above the water table is particularly conductive, it could be absorbing enough energy from the radar to obscure a telltale signal.

According to Farrell, the work will be useful for missions to other icy bodies too.

“We don’t want future geologists to look at their radar data and say no reflectance means no aquifer,” he said.

ANI

First acoustic metamaterial superlens invented

Washington, June 25: A team of researchers at the University of Illinois has created the world's first acoustic "superlens," an innovation that could have practical implications for high-resolution ultrasound imaging, non-destructive structural testing of buildings and bridges, and novel underwater stealth technology.

The team, led by Nicholas X Fang, a professor of mechanical science and engineering at Illinois, successfully focused ultrasound waves through a flat metamaterial lens on a spot roughly half the width of a wavelength at 60.5 kHz using a network of fluid-filled Helmholtz resonators.

According to the results, the acoustic system is analogous to an inductor-capacitor circuit.

The transmission channels act as a series of inductors, and the Helmholtz resonators, which Fang describes as cavities that house resonating waves and oscillate at certain sonic frequencies almost as a musical instrument would, act as capacitors.

Fang said acoustic imaging is somewhat analogous to optical imaging in that bending sound is similar to bending light.

But, compared with optical and X-ray imaging, creating an image from sound is "a lot safer, which is why we use sonography on pregnant women," said Shu Zhang, a U. of I. graduate student who along with Leilei Yin, a microscopist at the Beckman Institute, are co-authors of the research paper.

Acoustic imaging can be used for tumor detection.

"In the body, tumors are often surrounded by hard tissues with high contrast, so you can't see them clearly, and acoustic imaging may provide more details than optical imaging methods," said Fang.

Fang said that the application of acoustic imaging technology goes beyond medicine.

Eventually, the technology could lead to "a completely new suite of data that previously wasn't available to us using just natural materials," he said.

In the field of non-destructive testing, the structural soundness of a building or a bridge could be checked for hairline cracks with acoustic imaging, as could other deeply embedded flaws invisible to the eye or unable to be detected by optical imaging.

"Acoustic imaging is a different means of detecting and probing things, beyond optical imaging," Fang said.

Fang said acoustic imaging could also lead to better underwater stealth technology, possibly even an "acoustic cloak" that would act as camouflage for submarines.

"Right now, the goal is to bring this 'lab science' out of the lab and create a practical device or system that will allow us to use acoustic imaging in a variety of situations," he said.

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Indian scientists discover mysterious forms of water

London, June 24: Scientists at the Indian Institute of Science in Bangalore, along with researchers in Italy, have found two types of liquid water that have long been suspected to exist below water’s normal freezing point.

Unlike most liquids, water becomes less rather than more dense when it freezes — and it is densest not when it is coldest (at 0 degrees Celsius, just before it freezes) but at 4 degrees C.

These are just two of water’s host of anomalous properties, some of which are crucial to its behaviour in the natural environment.

In 1992, Gene Stanley of Boston University, Massachusetts, and his co-workers carried out computer simulations of water, which suggested that hydrogen bonds in water might produce two different types of liquid if water was made very cold and squeezed to high pressures.

In one form, the hydrogen bonds create a rather open, sparse network of water molecules, called low-density liquid (LDL) water. In the other, water molecules press closer at the cost of breaking some hydrogen bonds, forming a high-density liquid (HDL).

Stanley and his colleagues found that the two types of liquid water changed from one to the other in an abrupt ‘phase transition’, like the freezing/melting transition that separates ice and ordinary liquid water.

In this view, anomalies such as the density maximum at 4 degrees C are a reflection of the same competition between dense and less-dense states that creates the phase transition at much lower temperatures.

Now, Dino Leporini of the University of Pisa in Italy and his co-workers at the Indian Institute of Science in Bangalore say they have seen the two phases that Stanley’s team proposed in 1992.

The team used a technique called electron spin resonance to study the mobility of water molecules within tiny pockets of liquid trapped between crystallites of ice at temperatures down to around –183 degrees C.

They report that between about –140 and 0 degrees C, they can see two types of ‘liquid-like’ motion of the TEMPOL probes, presumably reflecting the presence of two types of water in the ice pockets.

One is slower than the other, and they interpret this as evidence for the presence of two distinct types of water: the more viscous LDL form, and the more fluid HDL.

According to Debenedetti, the results seem to reveal two different types of water, whose relative amounts change as the temperature changes.

ANI

Canadian scientists breeding cows that burp less

Toronto, June 23: Canadian scientists are breeding a special type of cow designed to burp less, a breakthrough that could reduce a big source of greenhouse gases responsible for global warming.

Cows are responsible for nearly three-quarters of total methane emissions, according to Environment Canada. Most of the gas comes from bovine burps, which are 20 times more potent than carbon dioxide as a greenhouse gas.

Stephen Moore, a professor at the University of Alberta in Edmonton, is examining the genes responsible for methane produced from a cow's four stomachs in order to breed more efficient, environmentally friendly cows.

The professor of agricultural, food and nutritional science completed primary tests using traditional techniques to breed efficient animals that produce 25 percent less methane than less efficient animals. But more work needs to be done before the long-term impact is known. Moore's study was published earlier this year in the Journal of Animal Science.

"We are working on producing diagnostic markers for efficient animals. We are looking at the next generation of technologies that will enable us to determine the genetics of an animal through a blood test or testing some hairs that you might pluck from the animal," said Moore.

To shrink cattle's ecological footprint, ranchers could also decrease the time cows are left standing in the field by getting animals to market sooner. That means breeding cattle that grow faster. Also, through breeding, cattle could become more efficient in converting feed into muscle and producing less methane and waste, said Moore.

Another method already being used to reduce methane emissions is feeding livestock a diet higher in energy and rich in edible oils, which ferment less than grass or low-quality feed.

New Hampshire-based Stonyfield Farm, an organic yogurt producer in which Groupe Danone holds a majority stake, reduced emissions from their cows on an average of 12 percent by adding alfalfa, flax or hemp to livestock feed on a small number of its farms.

"If every US dairy farmer reduced emissions by 12 percent it would be equal to about half a million cars being taken off the road," said Nancy Hirshberg, vice president of Stonyfield's Natural Resources department.

Bureau Report

New lunar topography map with the highest resolution

New York, June 22: Astronomers have created a new lunar topography map with the highest resolution of the moon's rugged south polar region, which they claim provides new data on some of the Earth's natural satellite's dark craters.

A team at NASA's Jet Propulsion Laboratory, Pasadena, in California created the map after collecting the data using the Deep Space Network's Goldstone Solar System Radar located in the Mojave Desert.

According to them, the map will help Lunar Crater Observation and Sensing Satellite (LCROSS) mission planners as they target for an encounter with a permanently dark crater near the lunar South Pole.

"Since the beginning of time, these lunar craters have been invisible to humanity. Now we can see detailed topography inside these craters down to 40 meters (132 feet) per pixel, with height accuracy of better than 5 meters (16 feet)," said Barbara Wilson, who led the team.

In fact, the astronomers targeted the moon's south polar region using Goldstone's 230-foot radar dish. The antenna, three-quarters the size of a football field, sent a 500-kilowatt-strong, 90-minute-long radar stream 373,046 kilometres to the moon, the US space agency said.

Signals were reflected back from the rough-hewn lunar terrain and detected by two of Goldstone's 34-meter (112-foot) antennas on Earth. The roundtrip time, from the antenna to the moon and back, was about two-and-a-half seconds.

The scientists compared their data with laser altimeter data recently released by the Japanese Aerospace Exploration Agency's Kaguya mission to position and orient the radar images and maps.

The new map provides contiguous topographic detail over a region approximately 500 kilometres by 400 kilometres.

Full resolution photos Moon 1, Moon 2.

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Scientists closer to identify mystery light that lit up universe

Sydney, June 21: Scientists in Australia are getting closer to identify the mystery light that lit up the universe.

The universe was covered in a thick fog of neutral hydrogen gas thirteen billion years ago.

However, astronomers have not been able to establish what led the fog to lift, allowing the universe to be lit up.

Dr Emma Ryan-Weber, from Swinburne University in Melbourne, and colleagues hypothesided that the fog cleared when the first stars were formed.

To test that theory, they measured the amount of carbon in the early universe. Because carbon indicates the presence of giant stars, this would show how many stars there were and whether they emitted enough light to clear the fog.

The researchers found that there was not as much carbon as they had expected and therefore massive stars were not solely responsible for the universe's illumination.

"There must have been light coming from something else such as an unknown population of quasars or carbon hidden in unobserved states," The Sydney Morning Herald quoted Ryan-Weber as saying.

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Scientists Detects High-Speed Hydrogen Atoms Coming From the Moon

Scientists probing the outer reaches of our solar system have hit upon an unusual phenomenon much closer to home. Instruments aboard a NASA spacecraft have detected fast-moving hydrogen atoms emanating from the moon. The atoms, which originated as protons from the sun, may help scientists study the lunar surface and other solar system objects in greater detail than believed possible.

The moon is continuously being pelted by hazardous radiation. Most of it comes from the solar wind, a stream of protons moving at about 1.6 million kilometers per hour in all directions from the sun. When these particles hit the moon, most stick to the lunar surface. But researchers suspected that a small number picked up electrons and bounced back into space as fast-moving hydrogen atoms. However, no one had detected these rebounding particles, until a team at the Southwest Research Institute (SwRI) in San Antonio, Texas, activated an instrument aboard NASA's Interstellar Boundary Explorer (IBEX) last December.

IBEX was designed to monitor the interstellar boundary, the region of space several billion kilometers away from Earth, where the outward pressure of the solar wind is balanced by the influence of incoming particles from all across the Milky Way. The SwRI team, led by space physicist David McComas, was starting up IBEX's high-speed particle detector just as the moon passed in front of its field of view. Suddenly, the instrument started picking up signals galore from high-speed hydrogen atoms streaming from the moon. "We were still testing the instrument," McComas says. "We hadn't even gotten into full science mode."

When they did, McComas and colleagues determined that as many as 10% of the solar protons that hit the moon bounce back into space as hydrogen atoms. Those atoms, the team explains this week in Geophysical Research Letters, are not electrically charged, so they can't be influenced by magnetic fields from the sun or Earth.

That means the particles can travel a long way undisturbed, such as back from the asteroids or the moons of Mars or even Jupiter, says physicist Yue Chen of Los Alamos National Laboratory in New Mexico. And because so many of them are reflected, they can help scientists build a portrait of the type of surface that reflected them, such as how dusty, rocky, or even icy it is.

One of the key questions in the evolution of planetary systems is how surfaces interact with the stellar wind, says physicist Larry Paxton of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. So these findings "will help us develop our understanding of the processes that shaped our world and the other planets."

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Photo: Southwest Research Institute

Scientists invent world’s fastest and most sensitive astronomical camera

Munich, June 19: Scientists have invented the world’s fastest and most sensitive astronomical camera that can take 1500 finely exposed images per second even when observing extremely faint objects.

The first 240x240 pixel images with the world’s fastest high precision faint light camera were obtained through a collaborative effort between ESO and three French laboratories from the French Centre National de la Recherche Scientifique/Institut National des Sciences de l’Univers (CNRS/INSU).

Cameras such as this are key components of the next generation of adaptive optics instruments of Europe’s ground-based astronomy flagship facility, the ESO Very Large Telescope (VLT).

“The performance of this breakthrough camera is without an equivalent anywhere in the world. The camera will enable great leaps forward in many areas of the study of the Universe,” said Norbert Hubin, head of the Adaptive Optics department at ESO.

OCam will be part of the second-generation VLT instrument SPHERE. To be installed in 2011, SPHERE will take images of giant exoplanets orbiting nearby stars.

A fast camera such as this is needed as an essential component for the modern adaptive optics instruments used on the largest ground-based telescopes.

Telescopes on the ground suffer from the blurring effect induced by atmospheric turbulence.

This turbulence causes the stars to twinkle in a way that delights poets, but frustrates astronomers, since it blurs the finest details of the images.

Adaptive optics techniques overcome this major drawback, so that ground-based telescopes can produce images that are as sharp as if taken from space.

The new generation instruments require these corrections to be done at an even higher rate, more than one thousand times a second, and this is where OCam is essential.

Cameras normally used for very high frame-rate movies require extremely powerful illumination, which is of course not an option for astronomical cameras.

OCam and its CCD220 detector, developed by the British manufacturer e2v technologies, solve this dilemma, by being not only the fastest available, but also very sensitive, making a significant jump in performance for such cameras.

Because of imperfect operation of any physical electronic devices, a CCD camera suffers from so-called readout noise.

OCam has a readout noise ten times smaller than the detectors currently used on the VLT, making it much more sensitive and able to take pictures of the faintest of sources.

ANI

Humans related to orangutans, not chimps or gorillas

Washington, June 18: In a new research, a team of scientists has suggested that humans most likely share a common ancestor with orangutans, not chimpanzees and gorillas.

The research, done by scientists from the University of Pittsburgh and the Buffalo Museum of Science, reject as "problematic" the popular suggestion, based on DNA analysis, that humans are most closely related to chimpanzees, which they maintain is not supported by fossil evidence.

Jeffrey H. Schwartz, professor of anthropology in Pitt's School of Arts and Sciences, and John Grehan, director of science at the Buffalo Museum, conducted a detailed analysis of the physical features of living and fossil apes that suggested humans, orangutans, and early apes belong to a group separate from chimpanzees and gorillas.

They then constructed a scenario for how the human-orangutan common ancestor migrated between Southeast Asia, where modern orangutans are from, and other parts of the world and evolved into now-extinct apes and early humans.

The study provides further evidence of the human-orangutan connection that Schwartz first proposed in his book "The Red Ape: Orangutans and Human Origins, Revised and Updated".

Schwartz and Grehan scrutinized the hundreds of physical characteristics often cited as evidence of evolutionary relationships among humans and other great apes like chimps, gorillas, and orangutans, and selected 63 that could be verified as unique within this group (that is, they do not appear in other primates).

Of these features, the analysis found that humans shared 28 unique physical characteristics with orangutans, compared to only two features with chimpanzees, seven with gorillas, and seven with all three apes (chimpanzees, gorillas, and orangutans).

Schwartz and Grehan then examined 56 features uniquely shared among modern humans, fossil hominids-ancestral humans such as Australopithecus-and fossil apes.

They found that orangutans shared eight features with early humans and Australopithecus and seven with Australopithecus alone.

The occurrence of orangutan features in Australopithecus contradicts the expectation generated by DNA analysis that ancestral humans should have chimpanzee similarities, according to Schwartz and Grehan.

Schwartz and Grehan pooled humans, orangutans, and the fossil apes into a new group called "dental hominoids," named for their similarly thick-enameled teeth.

They labeled chimpanzees and gorillas as African apes and determined that although they are a sister group of dental hominoids, "the African apes are not only less closely related to humans than are orangutans, but also less closely related to humans than are many" fossil apes.

Bureau Report

Clones of 9/11 hero dog unveiled in Los Angeles

Los Angeles, June 18: Five clones of a search and rescue dog which helped locate people trapped in the rubble of the 9/11 attacks were formally presented to their ancestor's former handler.

James Symington, a former Canadian police officer, choked back tears as he formally took possession of the five descendants of his beloved German shepherd named Trakr, who died in April.

Symington was presented with Trakr's offspring after winning a competition organized by California firm BioArts International -- the "Golden Clone Giveaway" -- to find the world's most "cloneworthy" dog.

Symington said he hopes the puppies -- Trustt, Valor, Prodigy, Solace and Deja Vu -- will go on to follow in Trakr's footsteps.

"We're here to celebrate that Trakr's legacy lives on in these five beautiful puppies," he told reporters. "If they have the same attributes Trakr did, then hopefully they'll develop into world class search and rescue dogs."

Symington and Trakr arrived at the site of the World Trade Center collapse, commonly referred to as Ground Zero, on September 12, 2001 and were one of the first K9 search and rescue teams on the scene.

After working nearly non-stop for 48 hours, Trakr located the last human survivor found in the rubble of the twin towers.

"Trakr was an extraordinary search and rescue dog. His work at Ground Zero was the culmination of his career," Symington said.

BioArts International, which says it offers the world's first commercial dog cloning service, partnered with South Korea's SooAm Biotech Research Foundation to clone Trakr under the direction of scientist Hwang Woo-Suk.

BioArts International chief executive Lou Hawthorne said canine cloning would remain beyond the reach of ordinary pet lovers, with cloned dogs costing an average 144,000 dollars each.

Hawthorne defended the right of people to clone their dogs instead of obtaining new pets from rescue shelters.

"I think 99 percent of the time people should get their pets from shelters," he told AFP.

"But can we agree though that one percent of the time if you have a one in a million dog and you have the money to pay for it, you should be able to go to either a breeder or a cloner?"

Hawthorne said Trakr had been chosen for cloning because of his heroics on 9/11. "We received many very touching submissions to our contest, describing some truly amazing dogs," he said. "But Trakr's story blew us away."

Symington meanwhile said that one member of his new litter -- Trustt -- was an exact replica of Trakr.

"The physical similarities are uncanny," he told AFP. "He's the spitting image of the Trakr that I first met in 1995. He has exactly the same markings, the way he moves, everything. Very alert, very intelligent and intuitive.

"I respect that cloning's not for everyone. But there are few dogs that are born with extraordinary abilities and Trakr was one of those dogs," he said.

"I look forward to the day that these puppies can follow in Trakr's footsteps and play an important role in other rescues, like Trakr did."

Bureau Report

Scientists break light modulation speed record

Washington, June 16: A team of scientists has broken the light modulation speed record, that too twice, with a signal-processing modulation speed of 4.3 gigahertz, breaking the previous record of 1.7 gigahertz held by a light-emitting diode.

The team, comprising of researchers at the University of Illinois and at U. of I. licensee Quantum Electro Opto Systems in Melaka, Malaysia, constructed a light-emitting transistor to set the new record.

By internally connecting the base and collector of a light-emitting transistor, they created a new form of light-emitting diode, which modulates at up to 7 gigahertz, breaking the speed record once again.

“Simple in design and construction, the tilted-charge light-emitting diode offers an attractive alternative for use in high-speed signal processing, optical communication systems and integrated optoelectronics,” said Nick Holonyak Jr, a John Bardeen Chair Professor of Electrical and Computer Engineering and Physics at Illinois.

The modulation speed of either a light-emitting diode or a light-emitting transistor is limited by the rate at which electrons and holes (the minus and plus charges – the carriers of current) recombine.

The recombination lifetime is important in determining device speed.

With a usual “slow” recombination process, the speed of a light-emitting diode is limited to approximately 1.7 gigahertz, which corresponds to a carrier lifetime of 100 picoseconds.

For more than 40 years, scientists thought breaking the 100-picosecond barrier was impossible.

To achieve high recombination speeds, an extremely high injection level and a very high charge population are required in light-emitting diodes.

These conditions are not necessary in transistors, however.

“Unlike a diode, a transistor does not store charge,” said Milton Feng, the Holonyak Chair Professor of Electrical and Computer Engineering.

“Charges are delivered to the transistor’s quantum well active region, where they either recombine almost instantly, or they are kept moving on out of the device. The charges do not become stacked-up, waiting to recombine with their oppositely charged twins,” he added.

To increase the modulation speed of their light-emitting transistor, the researchers reduced the emitter size, increased the so-called collector thickness (the third terminal region), and utilized a special internal common collector design.

These changes resulted in a faster signal at a very low current level, and at low heat dissipation.

Having a “fast” recombination process, the modulation speed of the light-emitting transistor was measured at 4.3 gigahertz, which corresponds to a recombination lifetime of 37 picoseconds, well under the “100-picosecond barrier.”

The tilted-charge light-emitting diode achieved a record-breaking modulation speed of 7 gigahertz, corresponding to a recombination lifetime of 23 picoseconds.

ANI

Scientists create non-expanding metal

Washington, June 16: Scientists at the California Institute of Technology (Caltech), using high pressure, have created a material that does not expand when heated, and acts like a metal with an entirely different chemical composition.

For creating this material, the scientists had to squeeze a typical metal alloy at pressures hundreds of thousands of times greater than normal atmospheric pressure.

The discovery offers insight into the exotic behaviour of materials existing at high pressures, which represent some 90 percent of the matter in our solar system.

Zero-expanding metal alloys were discovered in 1896 by Swiss physicist Charles Edouard Guillaume, who worked at the International Bureau of Weights and Measures in France.

While attempting to develop an inexpensive international standard for the meter, the metric unit of length, Guillaume hit upon an inexpensive iron-nickel alloy that expands very little when heated.

He dubbed the material an "Invar" alloy-because the metals are "invariant" when heated, such that the length of a piece of Invar metal does not change as its temperature is increased, as do normal metals.

Because of their unresponsiveness to temperature change, Invar alloys have been used in devices ranging from watches, toasters, light bulbs, and engine parts to computer and television screens, satellites, lasers, and scientific instruments.

Caltech graduate student Michael Winterrose, and his colleagues examined the effect of pressure on the alloy of palladium (Pd) and iron (Fe) called Pd3Fe, where three of every four atoms are palladium, and one is an iron atom.

"The Fe and Pd atoms (in the alloy) have very different sizes, and we expected to see some interesting effects from this size difference when we put Pd3Fe under pressure and measured its volume," Winterrose explained.

To test this, the scientists squeezed a small sample of the material between two diamond anvils, generating pressures inside the sample that were 326,000 times greater than standard atmospheric pressure.

"Our initial results from these studies showed that the alloy stiffened under pressure, but far more than we expected," Winterrose said.

To figure out the cause, the scientists simulated the quantum mechanical behaviour of the electrons in the alloy under pressure.

"The simulations showed that under pressure, the electrons found the special energy levels between strong and weak magnetism that are associated with normal Invar behaviour. Up to this point we had been quite unaware of the possibility for Invar behaviour in our material," Winterrose said.

According to Winterrose, the scientists had performed a kind of high-pressure "alchemy" on the alloy, where pressure makes the electrons act as if they are around atoms of a different chemical element.

Bureau Report

A tiny frozen microbe may hold clues to extraterrestrial life

A novel bacterium that has been trapped more than three kilometres under glacial ice in Greenland for over 120 000 years, may hold clues as to what life forms might exist on other planets. Dr Jennifer Loveland-Curtze and a team of scientists from Pennsylvania State University report finding the novel microbe, which they have called Herminiimonas glaciei, in the current issue of the International Journal of Systematic and Evolutionary Microbiology. The team showed great patience in coaxing the dormant microbe back to life; first incubating their samples at 2˚C for seven months and then at 5˚C for a further four and a half months, after which colonies of very small purple-brown bacteria were seen.

H. glaciei is small even by bacterial standards – it is 10 to 50 times smaller than E. coli. Its small size probably helped it to survive in the liquid veins among ice crystals and the thin liquid film on their surfaces. Small cell size is considered to be advantageous for more efficient nutrient uptake, protection against predators and occupation of micro-niches and it has been shown that ultramicrobacteria are dominant in many soil and marine environments.

Most life on our planet has always consisted of microorganisms, so it is reasonable to consider that this might be true on other planets as well. Studying microorganisms living under extreme conditions on Earth may provide insight into what sorts of life forms could survive elsewhere in the solar system.

"These extremely cold environments are the best analogues of possible extraterrestrial habitats", said Dr Loveland-Curtze, "The exceptionally low temperatures can preserve cells and nucleic acids for even millions of years. H. glaciei is one of just a handful of officially described ultra-small species and the only one so far from the Greenland ice sheet; studying these bacteria can provide insights into how cells can survive and even grow under extremely harsh conditions, such as temperatures down to -56˚C, little oxygen, low nutrients, high pressure and limited space."

"H. glaciei isn't a pathogen and is not harmful to humans", Dr Loveland-Curtze added, "but it can pass through a 0.2 micron filter, which is the filter pore size commonly used in sterilization of fluids in laboratories and hospitals. If there are other ultra-small bacteria that are pathogens, then they could be present in solutions presumed to be sterile. In a clear solution very tiny cells might grow but not create the density sufficient to make the solution cloudy".

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Sperm whales use babysitters for young

London, June 14: It's not only humans, but whales also use babysitters to look after their babies while they go out, a new study has revealed.

An international team, led by Dalhousie University, has carried out the study and found that mother sperm whales use organised babysitting sessions so they can go hunting for food, the 'Behavioural Ecology' journal reported.

According to researchers, whales use the equivalent of a babysitting pool in a bid to ensure mothers can feed without endangering their young.

Lead researcher Shane Gero said that in larger groups the babysitting tended to be reciprocal. "The diving behaviour of a group changes when a calf is present," he was quoted by 'The Daily Telegraph' as saying.

Sperm whales are one of the deepest diving whales on the planet and make dives of more than 2000ft below the ocean's surface lasting up to an hour while they search for the squid they feed on.

Added co-researcher Dr Luke Rendell, "The calves are therefore very vulnerable when left alone on the surface to attack from large marine predators which may include sharks but especially killer whales.

"Sperm whales are slow reproducers, 5 years is pretty good calving interval -- so that means every calf represents a huge investment for the mother."

For their study, the researchers spent two years following 23 sperm whale calves and their families through the Sargasso Sea around Bermuda and the Eastern Caribbean in a 40- foot research vessel.

They found that all of the youngsters were cared for by individuals other than their own mothers at given times. In some cases mothers would even nurse babies belonging to other members of the group.

In small groups, responsibility for babysitting a young calf would often fall to the same trusted female, often a great aunt. In larger groups, a number of females took turns to care for the calves of other members.

"It is not unreasonable to suggest that the need to protect vulnerable offspring could have been an important evolutionary driver of co-operation among sperm whales, just as it may have been in humans," Dr Rendell said.

Bureau Report

Mice cloned for the first time in Spain

Washington, June 13: Making one of the biggest breakthroughs in cloning, researchers at the Department of Cell Biology, Physiology and Immunology at Universitat Autonoma de Barcelona (UAB) have become the first one to clone mice in Spain.

The scientists created Cloe, Cleo and Clona-the three female brown-coloured mice that were born respectively on 12 May, 3 June and 10 June.

Using nuclear transfer techniques, the scientists collected mature oocytes, removed their chromosomes, and substituted them for the nucleus of an adult somatic cell.

The cloning of mice is part of a research meant to study new ways to improve the efficiency of the cloning process.

The researchers, who were in charge of cloning the mice, have said that all three of them are being suckled with other non-clones and their growth parameters are within normal range.

For cloning, the researchers collected oocytes and surrounding cumulus cells from several female mice.

They then extracted chromosomes from each of the oocytes and substituted it with a cell from the cumulus by cytoplasm injection.

After reconstructing the oocytes, the researchers reactivated them by simulating the stimuli occurring during fecundation so as to induce embryonic development.

The cloned embryos were later transferred to receptor females.

The mice thus obtained were not only the first of their species cloned in Spain, but are the first animals to survive at birth and develop correctly.

The cloning of the mice forms part of a research aimed at discovering new ways of improving the efficiency of the cloning process.

The researchers are now studying whether the use of valproic acid could contribute to an increase in the success rate of nuclear transfer cloning, currently situated at approximately 1 percent for mice using standard procedures.

Valproic acid is an inhibitor of the enzyme histone deacetylase, located at the cell nucleus where the DNA is found.

The studies at UAB can not only be applied to reproductive cloning of animal models, but can also be used for the reprogramming of cells for therapeutic aims.

ANI

An effective way to hunt other planets for signs of life

London, June 12: The hunt for finding alien life outside the solar system has just got easier -- thanks to astronomers who claim to have found an effective way to search the atmospheres of other planets for signs of life.

Using the William Herschel Telescope on La Palma, a team at the Instituto de Astrofisica de Canarias has gathered information about the chemical composition of the atmosphere of the Earth from sunlight that has passed through it.

When a planet passes in front of its parent star, part of the starlight passes through that planet's atmosphere and contains information about the constituents of the atmosphere, providing vital information about the heavenly body itself.

This is called a transmission spectrum and even though the astronomers cannot use exactly the same method to look at the Earth's atmosphere, they were able to gain a spectrum of our planet by observing light reflected from the Moon towards the Earth during a lunar eclipse.

According to the astronomers, the spectrum not only contained signs of life but these signs were unmistakably strong. It also contained unexpected molecular bands and the signature of the Earth's ionosphere.

Lead astronomer Enric Palle said: "Now we know what the transmission spectrum of a inhabited planet looks like, we have a much better idea of how to find and recognise Earth like planets outside solar system where life may be thriving.

"The information in this spectrum shows us that this is a very effective way to gather information about the biological processes that may be taking place on a planet."

Added team member Pilar Montañes-Rodriguez: "Many discoveries of Earth-size planets are expected in the next decades and some will orbit in the habitable zone of their parent stars.

"Obtaining their atmospheric properties will be highly challenging; the greatest reward will happen when one of those planets shows a spectrum like that of our Earth."

The findings are published in the latest edition of the 'Nature' journal.

Bureau Report

New element for periodic table

Scientists around the world are celebrating the latest entry to the periodic table.

It is taken more than a decade for element 112, the biggest and heaviest atom yet, to be officially recognised.

Now the scientific world is eager to find out who will have the honour of having the newest element named after them.

Dr John Kalman, a senior lecturer in chemistry at the University of Technology, Sydney, says the periodic table can now be redrawn with an extra name.

"The joint working party has now accepted the proof that this element does exist and now people have the opportunity to actually name it," says Kalman.

He says it has taken a decade for a scientific team based in Germany to get element 112 approved by authorities.

"They first detected this element in the late 1990s and it's only now that sufficient evidence has been accumulated by repeating experiments and so on, and doing new experiments, that it's become totally convincing," he says.

Heaviest addition

The new element muscles in at 227 times the atomic weight of hydrogen, making it the heaviest addition to the periodic table.

Dr Michael Hotchkis, a nuclear scientist with the Australian Nuclear Science and Technology Organisation (ANSTO) says the advanced technology used to make element 112 is of real practical interest.

"We use accelerators at ANSTO for the detection of signatures of nuclear activities," he says.

"It's using technology which is not so far removed from the technology that's used for the discovery of these new elements."

Hotchkis suggests the discoverers delve deep for name inspiration.

"I would like to nominate the ancient Greek philosopher, Empepedocles," he says.

"He suggested fire, water, earth, and air. It was the beginnings of science as we know it now and the beginnings of chemistry of understanding the constituents of matter.

"In the last few years, with the discovery of 10 or 12 elements since the 1940s, the people and places have already been acknowledged; for example, Einsteinian, Californian, Darmstadtium, so maybe we could look further back to ancient Greece."

Scientists will have to wait until the end of the year to find out who has been bestowed the honour of ending up on the wall chart of every science classroom.

And as the song goes, who knows when more elements will be uncovered?

"These are the only ones of which the news has come to Harvard; and there may be many others, but they haven't been discovered."

Source

Astronomers detect planet forming disk orbiting twin suns

Washington, June 11: Astronomers have found a planet forming disk orbiting twin suns in images captured from radio telescopes.

The sequence of images, collected with the Smithsonian’s Submillimeter Array (SMA), provide an unusually vivid snapshot of the process of formation of giant planets, comets, and Pluto-like bodies.

The results also confirm that such objects may just as easily form around double stars as around single stars like our Sun.

According to Joel Kastner of the Rochester (NY) Institute of Technology, the lead scientist on the study, “We had the first evidence for this rotating disk in radio telescope observations of V4046 Sagittarii that we made last summer. But at that point, all we had were molecular spectra, and there are different ways to interpret the spectra.”

“Once we saw the image data from the SMA, there was no doubt that we have a rotating disk here,” he said.

“This is strong evidence that planets can form around binary stars, which expands the number of places we can look for extrasolar planets. Somewhere in our galaxy, an alien world may enjoy double sunrises and double sunsets,” said co-author David Wilner of the Harvard-Smithsonian Center for Astrophysics (CfA).

According to UCLA graduate student David Rodriguez, the images clearly demonstrate that the molecular disk orbiting the V4046 Sagittarii binary system extends from within the approximate radius of Neptune''s orbit out to about 10 times that orbit.

This region corresponds to the zone where the solar system’s giant planets, as well as its Pluto-like Kuiper Belt objects, may have formed.

“We believe that V4046 Sagittarii provides one of the clearest examples yet discovered of a Keplerian, planet-forming disk orbiting a young star system,” Wilner said.

“This particular system is made that much more remarkable by the fact that it consists of a pair of solar-mass stars that are approximately 12 million years old and are separated by a mere 5 solar diameters,” he added.

“This could be the oldest known orbiting protoplanetary molecular disk. It shows that, at least for some stars, formation of Jovian-mass planets may continue well after a few million years, which astronomers have deduced is characteristic of the formation time for most such planets,” said Ben Zuckerman of UCLA.

The evidence for a molecular disk orbiting these twin young suns in the constellation Sagittarius suggested to the scientists that many such binary systems should also host as-yet-undetected planets.

ANI

Earth-Venus smash-up possible in 3.5 bn years

Paris, June 11: A force known as orbital chaos may cause our Solar System to go haywire, leading to possible collision between Earth and Venus or Mars, according to a study released Wednesday.

The good news is that the likelihood of such a smash-up is small, around one-in-2500.

And even if the planets did careen into one another, it would not happen before another 3.5 billion years.

Indeed, there is a 99 percent chance that the Sun's posse of planets will continue to circle in an orderly pattern throughout the expected life span of our life-giving star, another five billion years, the study found.

After that, the Sun will likely expand into a red giant, engulfing Earth and its other inner planets -- Mercury, Venus and Mars -- in the process.

Astronomers have long been able to calculate the movement of planets with great accuracy hundreds, even thousands of years in advance. This is how eclipses have been predicted.

But peering further into the future of celestial mechanics with exactitude is still beyond our reach, said Jacques Laskar, a researcher at the Observatoire de Paris and lead author of the study.

"The most precise long-term solutions for the orbital motion of the Solar System are not valid over more than a few tens of millions of years," he said in an interview.

Using powerful computers, Laskar and colleague Mickael Gastineau generated numerical simulations of orbital instability over the next five billion years.

Unlike previous models, they took into account Albert Einstein's theory of general relativity. Over a short time span, this made little difference, but over the long haul it resulted in dramatically different orbital paths.

The researchers looked at 2,501 possible scenarios, 25 of which ended with a severely disrupted Solar System.

"There is one scenario in which Mars passes very close to Earth," 794 kilometres (493 miles) to be exact, said Laskar.

"When you come that close, it is almost the same as a collision because the planets gets torn apart."

Life on Earth, if there still were any, would almost certainly cease to exist.

To get a more fine-grained view of how this might unfold, Laskar and Gastineau ran an additional two hundred computer models, slightly changing the path of Mars each time.

All but five of them ended in a two-way collision involving the Sun, Earth, Mercury, Venus or Mars. A quarter of them saw Earth smashed to pieces.

The key to all the scenarios of extreme orbital chaos was the rock closest to the Sun, found the study, published in the British journal Nature.

"Mercury is the trigger, and would be be the first planet to be destabilised because it has the smallest mass," explained Laskar.

At some point Mercury's orbit would get into resonance with that of Jupiter, throwing the smaller orb even more out of kilter, he said.

Once this happens, the so-called "angular momentum" from the much larger Jupiter would wreak havoc on the other inner planets' orbits too.

"The simulations indicate that Mercury, in spite of its diminutive size, poses the greatest risk to our present order," noted University of California scientists Gregory Laughlin in a commentary, also published in Nature.

Bureau Report

Speeding up brain networks may boost intelligence

A new study has finally solved the decade-old mystery about where exactly intelligence lies in human brains after scientists found that it's everywhere.

A team at Utrecht University has found that the most efficiently wired brains belong to the most intelligent people -- a finding that suggests that improving this efficiency with drugs could offer a tantalising means of boosting IQ.

According to lead scientist Martijn van den Heuvel, "The concept of a networked brain isn't so different from the transportation grids used by cars and planes.

"If you're flying from New York to Amsterdam, you can do it in a direct flight. It's much more effective than going from New York, then to Washington, and then to Amsterdam. It's exactly the same idea in the brain."

In fact, the scientists have based their findings on an analysis of 19 people -- an 8-minute-long snapshots of the brains of the volunteers were taken, as they did nothing in particular, the 'New Scientist' reported.

After mapping the communications between tiny slivers of brain, measured by a functional magnetic resonance imaging (fMRI) machine, the team found that the subjects' brains did not go completely quiet.

Bureau Report

Kill termites without using insecticides

New York, June 09: Termites can now be killed without using any chemical insecticides which may pave way for the development of natural protective shield for wooden material and crops, a new study headed by an NRI scientist suggests.

Ram Sasisekharan, Director of Harvard-MIT Division of Health Sciences and Technology at Massachusetts, has led the discovery of a novel method of blocking the immune system of these pests which helps them evade the deadly attacks of bacteria and fungi on their nests.

Termites normally secrete a form of an antimicrobial protein into their nests to prevent these pathogenic infections which can kill them. Scientists have identified a naturally found derivative of glucose called GDL which blocks the effects of the protective protein.

"GDL is relatively simple to make chemically. Also it can be genetically engineered to be produced in plants. It is conceivable that GDL or GDL like compounds can be designed to be used in the field to protect things from termites," Sasisekharan told PTI.

The researchers found that introduction of this natural, nontoxic and biodegradable substance on the termite nests causes quick deaths in colony from fungal infections.

The findings published in the journal 'Proceedings of the National Academy of Sciences' say that findings may provide a non-toxic method for protecting crops and buildings against termites and other destructive insects.

Bureau Report

Earth’s clearest skies visible from Antarctic plateau

London, June 08: A research team has found that the Antarctic plateau offers world-beating atmospheric conditions to view possibly the clearest skies on Earth.

Michael Ashley of the University of New South Wales in Sydney, Australia, and his colleagues wanted to find the best sites for astronomy on the Antarctic plateau.

Combining observations from satellites and ground stations with climate models, they evaluated different factors that affect telescope vision, such as the amount of water vapour, wind speeds and atmospheric turbulence.

The team found that the plateau offers world-beating atmospheric conditions, as long as telescopes are raised above its frozen surface.

The ice makes the lowest layers of air on the plateau much colder than those above, forming an “inversion layer” that, together with the strong local winds, can lead to severe turbulence. This would blur a telescope’s images.

The team’s analysis showed the inversion layer is only about 20 metres thick, however.

“If a telescope was mounted above it, its view would be affected by far less turbulence than at other world-class observatory sites,” said Ashley.

“It’s drier than Mauna Kea (in Hawaii) by a long way and drier than the Atacama desert (in Chile),” he added.

Such conditions would be good for studying star birth.

Normally, water vapour in the atmosphere blocks telltale emissions from molecular clouds in star-forming regions of the Milky Way.

But, the air above the high area known as Dome A is so dry that a ground-based telescope there could observe stellar nurseries, which is something that’s impossible anywhere else on Earth.

So far as Ashley’s team know, Dome A seems the best site for astronomy.

China has already built a summer station there, with a small robotic observatory. Next best is Dome F, the site of a Japanese station.

ANI

Indian scientists clone another buffalo named Garima

Scientists in the Indian state of Haryana have cloned a buffalo using foetal tissue, according to a report.

The female calf named Garima weighed 43 kilograms (95 pounds) and was born at the National Dairy Research Institute in the city of Karnal in northern India, according to a newspaper.

"Garima is absolutely healthy and we are fully optimistic about her survival," institute director AK Srivastava was quoted as saying.

India cloned the world's first buffalo in February, but it died of pneumonia within a week of its birth after being created from the ear tissue of a female buffalo.

Scientists cloned Garima using tissue from a foetus as part of a "hand-guided cloning technique" which allows the sex of the calf to be chosen.

Srivastava said India has the largest population of buffaloes in the world and that cloning would increase the percentage of elite animals in the species.

Bureau Report

Free-floating black hole torn apart star to create ‘firefly’

London, June 06: A new study has suggested that a wandering black hole may have torn apart a star to create a strange object that brightened mysteriously like a firefly and then faded from view in 2006.

The object, called SCP 06F6, was first spotted in the constellation Bootes in February 2006 in a search for supernovae by the Hubble Space Telescope.

The object flared to its maximum brightness over about 100 days, a period much longer than most supernovae, which do so in just 20 days.

Further analysis of the object’s spectrum in 2008 offered no more clues.

SCP 06F6 seemed to resemble no known object, and astronomers couldn’t even say whether the event originated in the Milky Way or beyond.

According to a report in New Scientist, Boris Gaensicke of the University of Warwick in Coventry, UK, and colleagues noticed that dips in the object’s light spectrum looked familiar.

They resembled those created when light passes through a relatively cool area that is rich in carbon. “These wiggles are basically the fingerprints of carbon molecules,” Gaensicke said.

The expansion of space stretched these wavelengths of absorbed light to the redder part of the spectrum. The amount of the stretching suggests the object sits some 2 billion light years away.

Gaensicke and colleagues envision a scenario that might explain the object.

In one, a carbon-rich star gets too close to a middle- or heavy-weight black hole, which tears the star apart.

Some of this material is absorbed by the black hole, and some is blasted away in a flare that was eventually seen from Earth as SCP 06F6.

Such flares brighten and dim with the same leisurely pace seen in SCP 06F6, and they also produce X-rays with a similar brightness to those the team found at the location of the firefly-like event.

According to Kyle Barbary of the University of California, Berkeley, finding another example of the ‘firefly’ event would be the next big step in figuring out what the object is.

“SCP 06F6 was found in a relatively small survey, so it is likely that there are a lot more of them out there. I’m quite hopeful that we will be able to find out the true nature of the event in the near future,” Barbary told.

ANI

Going into space can leave you short, fat and ugly

Making long space voyage might sound thrilling and macho, but it will do no good to your appearance, claim scientists who believe space travel will leave astronauts looking short, fat and bald.

Astrobiologist Dr Lewis Dartnell believes that near zero gravity would leave humans stunted and cause their bones and muscles to be underdeveloped.

Dartnell added, if humans spent extended periods in space they will have bloated faces and lose their hair. This will happen because fluid would pool in their skulls and there would be no need for insulation from the cold.

Dartnell, from University College London, said: "With little effort required to move around in microgravity and an environment that is never too hot or cold, future spacemen and women are likely to become pretty chubby.”

"Without gravity, fluid would float up to pool in the skull, which would cause the head to look permanently swollen out of proportion.

"Also, with no need for hair to insulate the head or eyelashes to flick dust from their eyes, future humans may become completely hairless,” he added.

While speaking at the Cheltenham Science Festival, Dartnell also addressed the question of what aliens might look like.

He said: "Certain features of the human body, such as camera-like eyes, head, and legs would evolve time and time again on different worlds, and so many features of alien animals are likely to be instantly recognisable.

"However other features of life, such as the number of limbs animals develop, or the shape and colour of trees, would be much more variable between worlds."

ANI

Mosquitoes sucking the life out of Galapagos wildlife

Washington, June 03: A team of scientists has discovered that some of the mosquitoes on the Galapagos island have developed a taste for reptile blood, thus threatening precious wildlife in the region.

The team comprised of scientists from the University of Leeds, the Zoological Society of London (ZSL) and the Galapagos National Park.

They have discovered that while its mainland ancestors prefer the blood of mammals and the occasional bird, the Galapagos form of the black salt marsh mosquito has shifted its behaviour to feed mainly on reptiles – primarily Galapagos giant tortoises and marine iguanas.

Using genetic techniques, the researchers showed that the mosquito colonised the Galapagos around 200,000 years ago and was not introduced by humans as previously thought, giving them time to adapt to conditions in Galapagos.

They have also found that unlike the mainland populations that normally live in mangroves and salt marshes along the coast, the Galapagos form of the mosquito can also breed up to 20 km inland and at altitudes of up to 700 meters.

The research team believes that the shift in feeding behaviour is an adaptation to life in Galapagos, since the islands had few mammal species prior to the arrival of Man some 500 years ago.

“When we started the work we thought that this species was also introduced by humans, so it was a surprise that it turned out to be so ancient,” said Arnaud Bataille, the University of Leeds and ZSL PhD student who carried out the work.

“The genetic differences of the Galapagos mosquitoes from their mainland relatives are as large as those between different species, suggesting that the mosquito in Galapagos may be in the process of evolving into a new species,” he added.

The findings raise fears that these changes could devastate the islands’ unique native wildlife if a new mosquito-borne disease is introduced - a scenario which is increasingly likely with the continuing rise in tourism.

Mosquitoes are known to transmit important wildlife diseases, such as avian malaria and West Nile fever.

While there is no evidence that such diseases are currently present on Galapagos, the widespread presence of the mosquito, and the fact that it feeds on a broad range of the native species, means that any new disease that arrives from the continent could spread rapidly to a wide variety to wildlife throughout the islands.

Due to its long isolation, Galapagos wildlife is not likely to have much immunity to new diseases, so the effects could be devastating.

ANI

Meteoroids helped making Earth habitable for life

London, June 02: Large bombardments of meteoroids approximately four billion years ago could have helped to make the Earth more habitable for life by modifying its atmosphere, according to a new study.

A team at Imperial College London has based its findings on the analysis of data from an ancient meteor shower called the Late Heavy Bombardment, which occurred four billion years ago, where millions of rocks crashed to Earth and Mars over a period of 20 million years.

Using published models of meteoritic impact rates during the LHB, researchers calculated that 10 billion tonnes of carbon dioxide and 10 billion tonnes of water vapour could have been delivered to atmospheres of Earth each year.

According to the researchers, this suggests that the LHB could have delivered enough carbon dioxide and water vapour to turn the atmospheres of the two planets into warmer and wetter environments that were more habitable for life.

However, according to the researchers, Mars' good fortune did not last. Unlike Earth, the Red Planet doesn't have a magnetic field to act as a protective shield from the Sun's solar wind. As a consequence, Mars was stripped of most of its atmosphere.

Lead author Dr Richard Court said, "Because of their chemistry, ancient meteorites have been suggested as a way of furnishing the early Earth with its liquid water.

"Now we have data that reveals just how much water and carbon dioxide was directly injected into the atmosphere by meteorites. These gases could have got to work immediately, boosting the water cycle and warming the planet."

Added co-author Prof Mark Sephton, "For a long time, scientists have been trying to understand why Earth is so water rich compared to other planets in our solar system.

"The LHB may provide a clue. This may have been a pivotal moment in our early history where Earth’s gaseous envelope finally had enough of the right ingredients to nurture life on our planet."

Bureau Report