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Monday, December 1, 2008

Scanning the Skies with 1.4 Gigapixels


2400548669_336e54db73 Cameras are one of the hottest subjects for geek gadget envy, with increasingly evolved camera-phones boasting up to five megapixels, while dedicated camera-carriers brag about the ridiculously high resolution offered by eight megapixels. Which is why MIT took the time to remind us all who the alpha nerds are, building a billion-pixel camera. Which watches out for threats to Earth, as if the sheer ludicrous size of the camera wasn't cool enough.


The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) will scan the sky from beautiful Hawaii. This has long been a popular spot for observatories as one of the best vantage points on the surface (or at least that's what all the astronomers who get to work in Hawaii tell us, anyway).

The camera core is an eight by eight array of eight by eight arrays of cells. That's not an accidental repeat, that's eight to the fourth equals four thousand and ninety-six CCD cells, each one of which could kick the hell out of your little digital imager, adding up to a forty square centimeter focal plane with 1.4 Gigapixels.

The camera is billed as searching for rogue asteroids and other near Earth objects, because apparently you still have to justify building something like this with reasons other than "But look at how big the number is!" The system will be able to pick out objects as small as 300 meters (big enough to simulate several atomic warheads and take a good solid chunk out of a country). If the Pan-STARRS does pick up a species-busting asteroid on the way, we have to wonder what the "Rapid Response" in the title could be (apart from "take pictures for aliens to find when they sift through the wreckage.")

Maybe it has Bruce Willis's phone number.

___

By Luke McKinney

Photo credit: Institute for Astronomy, University of Hawaii

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Geysers on Saturn's Moon, Enceladus, May Signal Underground Water and Microbial Life


800pxsaturn_seen_from_enceladus_a_2 Scientists at Jet Propulsion Lab in California, the University of Colorado and the University of Central Florida in Orlando teamed up to analyze the plumes of water vapor and ice particles spewing from Saturn's Moon, Enceladus. They used data collected by the Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS). Cassini was launched from the Kennedy Space Center in 1997 and has been orbiting Saturn since July 2004.

The team, including, found that the source of plumes may be vents on the moon that channel water vapor from a warm, probably liquid source to the surface at supersonic speeds.

"There are only three places in the solar system we know or suspect to have liquid water near the surface," said UCF Assistant Professor Joshua Colwell. "Earth, Jupiter's moon Europa and now Saturn's Enceladus. Water is a basic ingredient for life, and there are certainly implications there. If we find that the tidal heating that we believe causes these geysers is a common planetary systems phenomenon, then it gets really interesting."

The team's findings support a theory that the plumes observed are caused by a water source deep inside Enceladus. This is not a foreign concept. On earth, liquid water exists beneath the 15-million year-old ice at Lake Vostok, in Antarctica.

Scientists suggest that in Enceladus’s case, the ice grains would condense from the vapor escaping from the water source and stream through the cracks in the ice crust before heading into space. That’s likely what Cassini’s instruments detected in 2005 and 2007, the basis for the team’s investigation.

The team's work also suggests that another hypothesis is unlikely. That theory predicts that the plumes of gas and dust observed are caused by evaporation of volatile ice freshly exposed to space when Saturn’s tidal forces open vents in the south pole. But the team found more water vapor coming from the vents in 2007 at a time when the theory predicted there should have been less.

"Our observations do not agree with the predicted timing of the faults opening and closing due to tidal tension and compression," said Candice Hansen, the lead author on the project. "We don’t rule it out entirely . . . but we also definitely do not substantiate this hypothesis."

Instead, their results suggest that the behavior of the geysers supports a mathematical model that treats the vents as nozzles that channel water vapor from a liquid reservoir to the surface of the moon. By observing the flickering light of a star as the geysers blocked it out, the team found that the water vapor forms narrow jets. The authors theorize that only high temperatures close to the melting point of water ice could account for the high speed of the water vapor jets.

Although there is no solid conclusion yet, there may be one soon. Enceladus is a prime target of Cassini during its extended Equinox Mission, underway now through September 2010.

The team of researchers also includes Brad Wallis, and Amanda Hendrix from Jet Propulsion Laboratory; Larry Esposito (principal investigator of the UVIS investigation), Bonnie Meinke and Kris Larsen from the University of Colorado; Wayne Pryor from Central Arizona College; and Feng Tian, from NASA’s postdoctoral program.

"We still have a lot to discover and learn about how this all works on Enceladus," Colwell said. "But this is a good step in figuring it all out."

Until the two Voyager spacecraft passed near Enceladus, the sixth-largest moon of Saturn, in the early 1980s, very little was known about this small moon except for the identification of water ice on its surface. The Voyager missions showed that Enceladus is only 500 km in diameter and reflects almost 100% of the sunlight that strikes it. Voyager 1 found that Enceladus orbited in the densest part of Saturn's diffuse E ring, indicating a possible link between the two, while Voyager 2 revealed that despite the moon's small size, it had a wide range of terrains ranging from ancient, heavily cratered surfaces to young, tectonically deformed terrain, with some regions with surface ages as young as 100 million years old.

The Cassini spacecraft performed several close flybys of Enceladus in 2005, revealing the moon's surface and environment in greater detail. In particular, the probe discovered a water-rich plume venting from the moon's south polar region. This discovery, along with the presence of escaping internal heat and very few (if any) impact craters in the south polar region, shows that Enceladus is geologically active today.

Given the level of tectonic resurfacing found on Enceladus, a critical factor in the evolution of life on Earth, has been an important driver of geology on this small moon. Enceladus the fourth body in the solar system to have confirmed volcanic activity, along with Earth, Neptune's Triton, and Jupiter's Io.

There are three ecosystems discovered on Earth that could mirror possible lifeforms on Enceladus. Two are based on methanogens, which belong to an ancient group related to bacteria, called the archaea -- the hardy survivalists of bacteria that thrive in harsh environments without oxygen. Deep volcanic rocks along the Columbia River and in Idaho Falls host two of these ecosystems, which pull their energy from the chemical interaction of different rocks. The third ecosystem is powered by the energy produced in the radioactive decay in rocks, and was found deep below the surface in a mine in South Africa.

NASA's Cassini spacecraft discovered a surprising organic brew erupting in geyser-like fashion from Saturn's moon Enceladus during a close flyby on March 12, 2008. Scientists were stunned that this tiny moon is so active, "hot" and teeming with water vapor and organic chemicals.

"Enceladus has got warmth, water and organic chemicals, some of the essential building blocks needed for life," said Dennis Matson, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We have quite a recipe for life on our hands, but we have yet to find the final ingredient, liquid water, but Enceladus is only whetting our appetites for more."

"A completely unexpected surprise is that the chemistry of Enceladus, what's coming out from inside, resembles that of a comet," said Hunter Waite, principal investigator at the Southwest Research Institute in San Antonio. "To have primordial material coming out from inside a Saturn moon raises many questions on the formation of the Saturn system."

"Enceladus is by no means a comet. Comets have tails and orbit the sun, and Enceladus' activity is powered by internal heat while comet activity is powered by sunlight. Enceladus' brew is like carbonated water with an essence of natural gas," said Waite.

The Casssini Ion and Neutral Mass Spectrometer saw a much higher density of volatile gases, water vapor, carbon dioxide and carbon monoxide, as well as organic materials, some 20 times denser than expected. This dramatic increase in density was evident as the spacecraft flew over the area of the plumes.

New high-resolution heat maps of the south pole by Cassini's Composite Infrared Spectrometer show that the so-called tiger stripes, giant fissures that are the source of the geysers, are warm along almost their entire lengths, and reveal other warm fissures nearby. The warmest regions along the tiger stripes correspond to two of the jet locations seen in Cassini images.

"These spectacular new data will really help us understand what powers the geysers. The surprisingly high temperatures make it more likely that there's liquid water not far below the surface," said John Spencer, Cassini scientist on the Composite Infrared Spectrometer team at the Southwest Research Institute in Boulder, Colo.

Previous ultraviolet observations showed four jet sources, matching the locations of the plumes seen in previous images. This indicates that gas in the plume blasts off the surface into space, blending to form the larger plume.

At closest approach, Cassini was only 30 miles from Enceladus. When it flew through the plumes it was 120 miles from the moon's surface. Cassini's next flyby of Enceladus is in August.

The first step toward answering the question of whether life exists inside the subsurface aquifer of Enceladus is to analyze the organic compounds in the plume. Cassini's March 12 passage through the plume provided some measurements that help us move toward an answer, and preliminary plans call for Cassini to fly through the plume again for more measurements in the future. Ultimately, another mission in the future could conceivably land near the plume or even return plume material to Earth for laboratory analysis.

Organic chemicals were part of the raw material from which Enceladus and Saturn's other moons formed. The origin of Enceladus' heat is less clear, but there are several possibilities that could have given Enceladus a layer of liquid water that persists today. Early on, it could have been heated by decay of short-lived radioactivity in rocks, with the heating prolonged by tidal influences.

Or perhaps an earlier oblong orbit could have brought more tidal heating than exists there today. A past tidal relationship with another moon could have caused the heat. Another theory says the heat could have been produced from a process called serpentization, where chemical binding of water and silicate rock could occur at the upper layer of the moon's core. This increases the volume of the rock and creates energy in the form of heat.

Any of these heating mechanisms might have created a liquid subsurface aquifer solution rich in organics, allowing Enceladus to serve up a suitable prebiotic soup.

The deep sea vent theory for the origin of life on Earth might apply to Enceladus as well. In this scenario, life on Earth began at the interface where chemically rich fluids, heated by tidal or other mechanisms, emerge from below the sea floor. Chemical energy is derived from the reduced gases, such as hydrogen-sulfide and hydrogen coming out from the vent in contact with a suitable oxidant, such as carbon dioxide. Hot spots on an Enceladus sea floor could be locales for this type of process.

We don't know how long it takes for life to start when the ingredients are there and the environment is suitable, but it appears to have happened quickly on Earth. So maybe it was possible that on Enceladus, life started in a "warm little pond" below the icy surface occurring over the last few tens of millions of years.

For life to persist once it has been established requires an environment of liquid water, the essential elements and nutrients, and an energy source. On Enceladus, there is evidence for liquid water, but we don't know its origin. The March 12 close flyby indicates there are some complex organic chemicals, as well. An energy source of some sort is producing geysers. As Cassini's exploration continues, NASA is seeking to bring together more pieces of this intriguing puzzle.

Posted by Casey Kazan.

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Believe in God? Oh, no. But I swear by little green men, ghosts and mediums

By Daily Mail Reporter

Believing in ghosts and little green men from outer space appears a touch easier than having faith in God, according to a survey.

The researchers found that while 54 per cent of us are convinced the Almighty exists, 58 per cent believe in the supernatural.

The findings, maybe somewhat unsurprisingly, have been issued to mark the DVD release of The X-Files: I Want to Believe. The film stars David Duchovny and Gillian Anderson who made the TV series such a success.

Alien

Have we met? A survey has found more people believe in supernatural activity than God

They play FBI agents who investigate cases which appear to have some unexplained, paranormal element.

The research put out to coincide with the DVD release also claimed women were more likely to believe in the supernatural than men, and were more likely to visit a medium.

Nearly a quarter of the 3,000 surveyed claimed they had had a paranormal encounter.

Some 37 per cent said aliens and ghosts were the basis of their belief system.

Earlier this year reports released by the National Archives detailed UFO sightings logged by the UK Government. These included a fisherman who described being taken on to a spacecraft - only to be rejected because of his age.

Another survey last year highlighted concern over declining moral standards - attributed chiefly to a retreat in religious beliefs.

x-files

David Duchovny as Fox Mulder and Gillian Anderson as Dr Dana Scully get to work in the X-Files film I Want To Believe

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Heart disease 'reversed in mice'

Heart
Tiny fragments of genetic material can play a role in heart disease

Scientists have halted the advance of heart disease in mice - and even reversed some of its effects.

The study provides hard evidence that tiny pieces of genetic material called microRNA can play a key role in the development of heart disease.

The therapy, featured in the journal Nature, targets and blocks microRNA in heart cells.

A US specialist said that, with trials under way in other animals, human tests may be only a few years away.

This is one of the hottest topics in biology at the moment
Professor Eric Olson
University of Texas Southwestern Medical Center

The importance of microRNAs to heart disease - and a host of other diseases - has already been suggested by other scientists.

Their job is to regulate the activity of our genes, but with many different types present in the cell, scientists are trying to establish which plays the biggest role.

The US and German scientists are focusing on one type labelled microRNA-21, and their role in a type of heart cell called the cardiac fibroblast, which helps provide the structure of the organ, and plays a critical role in the progressive scarring which stops it working properly in heart disease.

Until recently, that process was thought to be an irreversible one.

The researchers found that cells in a failing heart had higher levels of this microRNA, and linked it to a chemical signalling pathway which leads to the tissue damage found in the condition.

Animal studies

In mice, they used a chemical which blocked microRNA-21, and found that not only that this pathway was interrupted, but that cardiac function in the animals improved.

This, they wrote, proved its potential as a new target for drugs in heart diseased humans.

Professor Eric Olson, from the University of Texas Southwestern Medical Center, whose own research focuses on microRNAs and heart disease, said that the results were "exciting".

"This is one of the hottest topics in biology at the moment," he said.

"Micro-RNAs are being very seriously considered as a therapeutic target - there is a lot of promise and potential in this area.

"This research suggests you can reverse or prevent aspects of heart disease."

He said: "There are already studies in large animals using micro-RNA inhibitors in heart disease - I can envisage that in a few years we will see this in human trials."

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Navy Retires 40 Year Old “Secret” Sub

The Navy retired a 40 year old, nuclear sub, used reach depths of 3000 feet.

It still amazes me that that 40 years ago we built things like the Saturn rockets, this little sub, and the Blackbird. We’ve refined our technologies, but it is almost as if we have hit a wall in moving on to the next “big” thing.

NORFOLK, Va. — Its oven was actually a toaster taken out of a P-3 Orion. It had no shower, and there were four racks for 11 sailors. The officer in charge slept on the deck behind the conn. And since the Nixon administration, the elite crew of the NR-1 could live on the bottom of the ocean for up to a month at a time.

National Geographic magazine called it “The Navy’s Inner Space Shuttle,” and in many ways, the now retired nuclear-powered, deep-submergence boat capable of 3,000-foot dives was just that.

“I’ve been in it for a month, and it gets a little ripe,” said Robert Ballard, sea explorer and former Navy man who, among scores of other finds, discovered the wreck of the Titanic in 1985 and John F. Kennedy’s PT 109 in 2003.

Although he didn’t use the NR-1 for those missions, he was aboard for countless explorations, and with its deactivation Nov. 21, he said he hates to see this one-of-a-kind ship retire.

“We’ve lost an asset, and it’s too bad,” Ballard told Navy Times.

Launched in Groton, Conn., in January 1969, for years NR-1 was a secret submersible built to dive so deep it had wheels for moving along the ocean floor. Because of its nuclear reactor, its dwell time was not limited by batteries like other submersibles. But it was not fast, managing a little more than 3 knots submerged.

“That’s more than fast enough to operate near the ocean floor,” said Cmdr. John McGrath, NR-1’s final officer in charge. “I’m a big fan of the ship. I think it’s an incredible chapter in Navy history.”

In its time, NR-1 was manned by nuclear-qualified submariners who passed an interview with the director of naval nuclear propulsion, currently Adm. Kirkland Donald. McGrath is rarer still among this small fraternity of submariners, having previously served as NR-1 engineer from 1997 to 2000. He came back in 2007 and will oversee the yearlong process of de-fueling the sub’s nuclear reactor before its voyage to the Navy’s submarine graveyard in Puget Sound, Wash.

In its nearly 40-year career, the NR-1 was called for countless missions — from searching for wrecked and sunken naval aircraft to finding debris from the space shuttle Challenger after its loss in 1986.

On its final deployments, McGrath said, the NR-1 was still conducting “highly classified military missions.”

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Women have affairs in early 30s 'to maximise chances of reproducing', say scientists

By Richard Alleyne, Science Correspondent

Researchers have discovered that women - unlike many men - instinctively prefer a monogamous relationship, mainly because they need help bringing up any resultant children.

But if they do stray it's more likely to be when they enter their 30s as their biological clock starts ticking.

Much like many celebrities, such as Kate Beckinsale and Amanda Holden, they perceive the age to be the beginning of their last chance for them to secure a good man to father their children.

It also coincides with them reaching their sexual peak and when they are most likely to have the most opportunities to have an affair.

The conclusion made by Dr David Schmitt of Bradley University, Illinois, was made after he collected data on the sexual habits of women from 48 countries across the world.

He found that while men's "sociosexuality" or promiscuousness peaks in their late 20s, women are most likely to be unfaithful to their partners in their early 30s.

Dr Schmitt told New Scientist that women were more likely to have an affair when their fertility first begins to wane.

"That's exactly the point where the odds of conceiving start to drop at a bigger rate, and it's also the point where the odds of having a child with a genetic problem or birth defect start to go up," he said.

Of course plenty of women have babies much later, but Dr Schmitt suggests that women's increased sociosexuality at around this time reflects an evolved reproductive strategy that maximises the chances of their conceiving and bearing a healthy child.

The research appears to be backed up by high profile marriage break ups. Miss Beckinsale, the British actress left her Welsh husband Michael Sheen after an affair when she was 30.

Amanda Holden divorced Les Dennis in December 2003 when she was 32 after being unfaithful with Neil Morrissey.

The research by Dr Schmitt also showed that the levels of promiscuousness in society also varied depending on the relative abundance of men.

In east Asian countries such as China, Japan and South Korea, where the population is heavily male biased there is a relatively low level of interest in uncommitted, casual sex.

Meanwhile, urban areas of the US with low ratios of men to women, had a correspondingly high level of short-term relationships and divorce.

Anne Campbell, a psychologist at the University of Durham, said: "This means men can call the shots, and what men usually want is casual sex."

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Virtual Ears And The Cocktail Party Effect


The 'cocktail party effect' describes how our brains develop the ability to focus on particular sounds among a background of noise. (Credit: iStockphoto/Cat London)

Oxford University research has helped understanding of the so-called ‘cocktail party effect’ – how our brains develop the ability to pinpoint and focus on particular sounds among a background of noise.

The study, published in the Journal of Neuroscience, has implications for the emergence of hearing abilities in children and for restoring hearing after fitting hearing aids and cochlear implants.

Humans begin to develop their hearing at a very early stage. Even a 28 week old foetus will respond to sound, and newborn infants can distinguish different types of speech sound. Our hearing continues to develop throughout childhood, including the ability to distinguish between sounds coming from different directions and to understand speech in difficult acoustic environments, such as a busy room with many echoes.

Nerve cells in the superior colliculus, one of the brain regions responsible for processing sound, mature during infancy, gradually developing a preference for specific sound directions. Which of these nerve cells are active therefore signals where sounds are located, forming an auditory map of the environment.

Researchers led by Professor Andrew King, a Wellcome Trust Principal Research Fellow at the University of Oxford, have developed a method that enables the changes in the selectivity of the nerve cells for different directions of space to be to separated out from the development of the auditory map.

The technique, used on ferrets, involves using ‘virtual ears’ which can enable an infant ferret to hear sounds as if it were an adult.

The researchers in the Department of Physiology, Anatomy and Genetics placed tiny microphones inside the opening of the ears of adult ferrets to capture the sound as modulated by an adult head. This sound, when played back over headphones to an infant ferret, appears to be coming from outside the ferret's head, but mimics what an adult would hear.

By measuring the responses of nerve cells in the brain, the researchers were able to see how the infant brain differs from the adult and to show that the development of the selectivity of the nerve cells for sound location and their assembly into the auditory map are influenced by independent factors.

"Our research showed that the region of space to which the nerve cells respond is determined by the shape of the ferret's ears and their distance apart, both of which change with age," says Professor King. "On the other hand, the gradual development of the auditory map is influenced by the experience of the sounds that are heard."

Professor King believes that this has implications for a child’s ability to learn how to hear after a hearing aid or cochlear implant has been fitted. Other work from this group has shown that even the adult brain is remarkably able to adapt.

"We have shown that the neural circuits of our hearing apparatus can adjust to a loss of hearing in one ear," says Professor King. "Clearly, the adult brain is still plastic and able to adapt, so fitting hearing aids and cochlear implants in adults is worthwhile."

The research was funded by the Wellcome Trust, the Lister Institute for Preventive Medicine and the Biotechnology and Biological Sciences Research Council.

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Harvard Team Unlocks Clues to Genes that Control Longevity


Longevity Harvard Medical School Researchers have used a single compound to increase the lifespan of obese mice, and found that the drug reversed nearly all of the changes in gene expression patterns found in mice on high calorie diets--some of which are associated with diabetes, heart disease, and other significant diseases related to obesity.

The research, led by investigators at Harvard Medical School and the National Institute on Aging, is the first time that the small molecule resveratrol has been shown to offer survival benefits in a mammal.

"Mice are much closer evolutionarily to humans than any previous model organism treated by this molecule, which offers hope that similar impacts might be seen in humans without negative side-effects," says co-senior author David Sinclair, HMS associate professor of pathology, and co-director of the Paul F. Glenn Labs for the Biological Mechanisms of Aging.

"After six months, resveratrol essentially prevented most of the negative effects of the high calorie diet in mice," said Rafael de Cabo, Ph.D., the study's other co-senior investigator from the National Institute on Aging's Laboratory of Experimental Gerontology, Aging, Metabolism, and Nutrition Unit. "There is a lot of work ahead that will help us better understand resveratrol's roles and the best applications for it."

Resveratrol is found in red wines and produced by a variety of plants when put under stress. It was first discovered to have an anti-aging properties by Sinclair, other HMS researchers, and their colleagues in 2003 and reported in Nature. The 2003 study showed that yeast treated with resveratrol lived 60 percent longer. Since 2003, resveratrol has been shown to extend the lifespan of worms and flies by nearly 30 percent, and fish by almost 60 percent. It has also been shown to protect against Huntington's disease in two different animal models (worms and mice).

"The "healthspan" benefits we saw in the obese mice treated with resveratrol, such as increased insulin sensitivity, decreased glucose levels, healthier heart and liver tissues, are positive clinical indicators and may mean we can stave off in humans age-related diseases such as type 2 diabetes, heart disease, and cancer, but only time and more research will tell," says Sinclair, who is also a co-founder of Sirtris, a company with an author on this paper and which is currently in a phase 1b trial in humans with diabetes using an enhanced, proprietary formulation of resveratrol. [Harvard has license and equity interests with Sirtris, which is not a public company.]

Investigators identified resveratrol while looking for compounds that activate Sir2, an enzyme linked to lifespan extension in yeast and other lower organisms. For the last 70 years, scientists have been able to increase the lifespan of a variety of species by reducing their normal food consumption by 30 to 40 percent - a diet known as calorie restriction. Through this research, scientists identified Sir2 as a key contributor to life extension. Without Sir2, for example, fruit flies see none of the benefits from either calorie restriction or treatment by resveratrol. The mammalian version of the Sir2 gene is SIRT1, which has the same enzymatic activity as Sir2, but modifies a wider variety of molecules throughout cells. Indicators in this study show that resveratrol might also be activating SIRT1 in mice, as well as other known longevity pathways.

The study examined three groups of mice, one on a standard diet (SD), another on a high calorie diet (HC) with 60 percent of calories coming from fat, and a third group of mice on the same high calorie diet but also treated with resveratrol (HCR). At middle age, or roughly 52 weeks of life, the researchers put the mice on the different diets.

At 60 weeks of age, the survival rates of HC and HCR fed mice groups began to diverge and remained separated by a three to four month span. At 114 weeks of age, 58 percent of the HC fed mice had died, compared to 42 percent of the HCR and SD groups. Presently, the team has found resveratrol to reduce the risk of death from the HC diet by 31 percent, to a point where it is not significantly increased over the SD group.(Note: Given that mice are still living, final calculations can't be made.)

"The median lifespan increase we are seeing is about 15 percent at this point," says Sinclair. "We won't have final lifespan numbers until all of the mice pass away, and this particular strain of mouse generally lives for two-and-a-half-years. So we are around five months from having final numbers, but there is no question that we are seeing increased longevity.

The team also found that the HCR fed mice had a much higher quality of life, outperforming the HC fed mice on motor skill tests. "The mice on resveratrol have not been just living longer," says Sinclair. "They are also living more active, better lives. Their motor skills actually show improvement as they grow older."

Mice on rotarodThe resveratrol fed mice also showed improved motor function with age over its HC fed counterparts. Researchers watched how well the mice did walking on a rotarod, similar to walking on a log in the water, a common measure of balance and motor coordination. At 24 months of age, the HC fed group would fall off the rotarod after 60 seconds, while the HCR group would stay on for nearly 120 seconds. The HCR group steadily improved their motor skills as they aged to the point where they were indistinguishable from the SD fed group.

The research team also wanted to see if resveratrol could reverse the changes in gene expression patterns triggered by high calorie diets. Using liver tissue of five mice at 18 months of age from each group, the team performed a whole-genome microarray and identified which genes were turned on or off. The researchers then used a database generated by the Broad Institute that groups individual genes into common functional pathways to see where there were major differences.

"We made a striking observation," says Sinclair. "Resveratrol opposed the effects of high caloric intake in 144 out of 153 significantly altered pathways. In terms of gene expression and pathway comparison, the resveratrol fed group was more similar to the standard diet fed group than the high calorie group."

In humans, high calorie diets can increase glucose and insulin levels leading to diabetes, cardiovascular disease, and non-alcoholic fatty liver disease. In the HC fed mice, researchers found biomarkers that might predict diabetes, including increased levels of insulin, glucose and insulin-like growth factor-1 (IGF-1). Conversely, the HCR fed group had significantly lower levels of these markers, paralleling the SD group. For example, a standard diabetes glucose test on the HCR fed group found considerably higher insulin sensitivity, meaning the HCR group had a lower disposition toward diabetes than the HC fed group. Lower insulin levels also predict increased lifespan in mice.

The researchers also found that the livers of mice at 18 months of age on the HC diet were greatly increased in size and weight. Liver tissue studies of these mice showed a loss of cellular integrity, and a build-up of lipids, which is common to high fat diets. In contrast, the HCR group had normal, healthy livers.

The researchers also looked for metabolic ties to resveratrol's impact: pathway changes that mimicked those caused by calorie restriction. They examined AMP-activated kinase (AMPK), a metabolic regulator that promotes insulin sensitivity and fatty acid oxidation. It's been shown in previous work that the lifespan of worms has been extended by the addition of copies the AMPK gene, and chronic activation of AMPK is seen on calorie-restricted diets. The researchers examined the livers of the HCR fed group and found a strong tendency for AMPK activation, as well as two downstream indicators of its activity.

Calorie restriction and exercise have also been previously shown to increase the number of mitochondria in the liver. Mitochondria generate energy in cells. Through electron microscopy, investigators showed that the livers of the HCR fed mice had considerably more mitochondria than the HC group, and were not significantly different from those of the SD group.

The team also asked if SIRT1 was activated by resveratrol in mice, as Sir2 is in lower organisms. To determine this, they looked at the amount of a specific chemical modification (acetylation) on the molecule PGC-1alpha. Removal of the "acetyl" chemical groups on PGC-1alpha activates this protein so that it can turn on certain genes that generate mitochondria and turn muscle into the type suited for endurance. The only enzyme known to remove the acetyl chemical groups on PGC-1alpha is SIRT1, and therefore the activity of PGC-1alpha is one of the most reliable and specific markers of SIRT1 activity in mammals. The research team found that levels of PGC-1alpha were three-fold lower in the HCR fed mice than in the HC mice, consistent with what would be expected when SIRT1 was being activated by resveratrol.

"This work demonstrates that there may be tremendous medical benefits to unlocking the secrets behind the genes that control our longevity," says Sinclair, "No doubt many more remain to be discovered in coming years."

Posted by Casey Kazan from materials provided by Harvard Medical School.

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The 10 big energy myths

Chris Goodall

In reality, today's bulky and expensive solar panels capture only 10% or so of the sun's energy, but rapid innovation in the US means that the next generation of panels will be much thinner, capture far more of the energy in the sun's light and cost a fraction of what they do today. They may not even be made of silicon. First Solar, the largest manufacturer of thin panels, claims that its products will generate electricity in sunny countries as cheaply as large power stations by 2012.

Other companies are investigating even more efficient ways of capturing the sun's energy, for example the use of long parabolic mirrors to focus light on to a thin tube carrying a liquid, which gets hot enough to drive a steam turbine and generate electricity. Spanish and German companies are installing large-scale solar power plants of this type in North Africa, Spain and the south-west of America; on hot summer afternoons in California, solar power stations are probably already financially competitive with coal. Europe, meanwhile, could get most of its electricity from plants in the Sahara desert. We would need new long-distance power transmission but the technology for providing this is advancing fast, and the countries of North Africa would get a valuable new source of income.

Myth 2: wind power is too unreliable

Actually, during some periods earlier this year the wind provided almost 40% of Spanish power. Parts of northern Germany generate more electricity from wind than they actually need. Northern Scotland, blessed with some of the best wind speeds in Europe, could easily generate 10% or even 15% of the UK's electricity needs at a cost that would comfortably match today's fossil fuel prices.

The intermittency of wind power does mean that we would need to run our electricity grids in a very different way. To provide the most reliable electricity, Europe needs to build better connections between regions and countries; those generating a surplus of wind energy should be able to export it easily to places where the air is still. The UK must invest in transmission cables, probably offshore, that bring Scottish wind-generated electricity to the power-hungry south-east and then continue on to Holland and France. The electricity distribution system must be Europe-wide if we are to get the maximum security of supply.

We will also need to invest in energy storage. At the moment we do this by
pumping water uphill at times of surplus and letting it flow back down the mountain when power is scarce. Other countries are talking of developing "smart grids" that provide users with incentives to consume less electricity when wind speeds are low. Wind power is financially viable today in many countries, and it will become cheaper as turbines continue to grow in size, and manufacturers drive down costs. Some projections see more than 30% of the world's electricity eventually coming from the wind. Turbine manufacture and installation are also set to become major sources of employment, with one trade body predicting that the sector will generate 2m jobs worldwide by 2020.

Myth 3: marine energy is a dead-end

The thin channel of water between the north-east tip of Scotland and Orkney contains some of the most concentrated tidal power in the world. The energy from the peak flows may well be greater than the electricity needs of London. Similarly, the waves off the Atlantic coasts of Spain and Portugal are strong, consistent and able to provide a substantial fraction of the region's power. Designing and building machines that can survive the harsh conditions of fast-flowing ocean waters has been challenging and the past decades have seen repeated disappointments here and abroad. This year we have seen the installation of the first tidal turbine to be successfully connected to the UK electricity grid in Strangford Lough, Northern Ireland, and the first group of large-scale wave power generators 5km off the coast of Portugal, constructed by a Scottish company.

But even though the UK shares with Canada, South Africa and parts of South America some of the best marine energy resources in the world, financial support has been trifling. The London opera houses have had more taxpayer money than the British marine power industry over the past few years. Danish support for wind power helped that country establish worldwide leadership in the building of turbines; the UK could do the same with wave and tidal power.

Myth 4: nuclear power is cheaper than other low-carbon sources of electricity

If we believe that the world energy and environmental crises are as severe as is said, nuclear power stations must be considered as a possible option. But although the disposal of waste and the proliferation of nuclear weapons are profoundly important issues, the most severe problem may be the high and unpredictable cost of nuclear plants.

The new nuclear power station on the island of Olkiluoto in western Finland is a clear example. Electricity production was originally supposed to start this year, but the latest news is that the power station will not start generating until 2012. The impact on the cost of the project has been dramatic. When the contracts were signed, the plant was supposed to cost €3bn (£2.5bn). The final cost is likely to be more than twice this figure and the construction process is fast turning into a nightmare. A second new plant in Normandy appears to be experiencing similar problems. In the US, power companies are backing away from nuclear because of fears over uncontrollable costs.

Unless we can find a new way to build nuclear power stations, it looks as though CO2 capture at coal-fired plants will be a cheaper way of producing low-carbon electricity. A sustained research effort around the world might also mean that cost-effective carbon capture is available before the next generation of nuclear plants is ready, and that it will be possible to fit carbon-capture equipment on existing coal-fired power stations. Finding a way to roll out CO2 capture is the single most important research challenge the world faces today. The current leader, the Swedish power company Vattenfall, is using an innovative technology that burns the coal in pure oxygen rather than air, producing pure carbon dioxide from its chimneys, rather than expensively separating the CO2 from other exhaust gases. It hopes to be operating huge coal-fired power stations with minimal CO2 emissions by 2020.

Myth 5: electric cars are slow and ugly

We tend to think that electric cars are all like the G Wiz vehicle, with a limited range, poor acceleration and an unprepossessing appearance. Actually, we are already very close to developing electric cars that match the performance of petrol vehicles. The Tesla electric sports car, sold in America but designed by Lotus in Norfolk, amazes all those who experience its awesome acceleration. With a price tag of more than $100,000, late 2008 probably wasn't a good time to launch a luxury electric car, but the Tesla has demonstrated to everybody that electric cars can be exciting and desirable. The crucial advance in electric car technology has been in batteries: the latest lithium batteries - similar to the ones in your laptop - can provide large amounts of power for acceleration and a long enough range for almost all journeys.

Batteries still need to become cheaper and quicker to charge, but the UK's largest manufacturer of electric vehicles says that advances are happening faster than ever before. Its urban delivery van has a range of over 100 miles, accelerates to 70mph and has running costs of just over 1p per mile. The cost of the diesel equivalent is probably 20 times as much. Denmark and Israel have committed to develop the full infrastructure for a switch to an all-electric car fleet. Danish cars will be powered by the spare electricity from the copious resources of wind power; the Israelis will provide solar power harvested from the desert.

Myth 6: biofuels are always destructive to the environment

Making some of our motor fuel from food has been an almost unmitigated disaster. It has caused hunger and increased the rate of forest loss, as farmers have sought extra land on which to grow their crops. However the failure of the first generation of biofuels should not mean that we should reject the use of biological materials forever. Within a few years we will be able to turn agricultural wastes into liquid fuels by splitting cellulose, the most abundant molecule in plants and trees, into simple hydrocarbons. Chemists have struggled to find a way of breaking down this tough compound cheaply, but huge amounts of new capital have flowed into US companies that are working on making a petrol substitute from low-value agricultural wastes. In the lead is Range Fuels, a business funded by the venture capitalist Vinod Khosla, which is now building its first commercial cellulose cracking plant in Georgia using waste wood from managed forests as its feedstock.

We shouldn't be under any illusion that making petrol from cellulose is a solution to all the problems of the first generation of biofuels. Although cellulose is abundant, our voracious needs for liquid fuel mean we will have to devote a significant fraction of the world's land to growing the grasses and wood we need for cellulose refineries. Managing cellulose production so that it doesn't reduce the amount of food produced is one of the most important issues we face.

Myth 7: climate change means we need more organic agriculture

The uncomfortable reality is that we already struggle to feed six billion people. Population numbers will rise to more than nine billion by 2050. Although food production is increasing slowly, the growth rate in agricultural productivity is likely to decline below population increases within a few years. The richer half of the world's population will also be eating more meat. Since animals need large amounts of land for every unit of meat they produce, this further threatens food production for the poor. So we need to ensure that as much food as possible is produced on the limited resources of good farmland. Most studies show that yields under organic cultivation are little more than half what can be achieved elsewhere. Unless this figure can be hugely improved, the implication is clear: the world cannot feed its people and produce huge amounts of cellulose for fuels if large acreages are converted to organic cultivation.

Myth 8: zero carbon homes are the best way of dealing with greenhouse gas emissions from buildings

Buildings are responsible for about half the world's emissions; domestic housing is the most important single source of greenhouse gases. The UK's insistence that all new homes are "zero carbon" by 2016 sounds like a good idea, but there are two problems. In most countries, only about 1% of the housing stock is newly built each year. Tighter building regulations have no effect on the remaining 99%. Second, making a building genuinely zero carbon is extremely expensive. The few prototype UK homes that have recently reached this standard have cost twice as much as conventional houses.

Just focusing on new homes and demanding that housebuilders meet extremely high targets is not the right way to cut emissions. Instead, we should take a lesson from Germany. A mixture of subsidies, cheap loans and exhortation is succeeding in getting hundreds of thousands of older properties eco-renovated each year to very impressive standards and at reasonable cost. German renovators are learning lessons from the PassivHaus movement, which has focused not on reducing carbon emissions to zero, but on using painstaking methods to cut emissions to 10 or 20% of conventional levels, at a manageable cost, in both renovations and new homes. The PassivHaus pioneers have focused on improving insulation, providing far better air-tightness and warming incoming air in winter, with the hotter stale air extracted from the house. Careful attention to detail in both design and building work has produced unexpectedly large cuts in total energy use. The small extra price paid by householders is easily outweighed by the savings in electricity and gas. Rather than demanding totally carbon-neutral housing, the UK should push a massive programme of eco-renovation and cost-effective techniques for new construction.

Myth 9: the most efficient power stations are big

Large, modern gas-fired power stations can turn about 60% of the energy in fuel into electricity. The rest is lost as waste heat.

Even though 5-10% of the electricity will be lost in transmission to the user, efficiency has still been far better than small-scale local generation of power. This is changing fast.

New types of tiny combined heat and power plants are able to turn about half the energy in fuel into electricity, almost matching the efficiency of huge generators. These are now small enough to be easily installed in ordinary homes. Not only will they generate electricity but the surplus heat can be used to heat the house, meaning that all the energy in gas is productively used. Some types of air conditioning can even use the heat to power their chillers in summer.

We think that microgeneration means wind turbines or solar panels on the roof, but efficient combined heat and power plants are a far better prospect for the UK and elsewhere. Within a few years, we will see these small power plants, perhaps using cellulose-based renewable fuels and not just gas, in many buildings. Korea is leading the way by heavily subsidising the early installation of fuel cells at office buildings and other large electricity users.

Myth 10: all proposed solutions to climate change need to be hi-tech

The advanced economies are obsessed with finding hi-tech solutions to reducing greenhouse gas emissions. Many of these are expensive and may create as many problems as they solve. Nuclear power is a good example. But it may be cheaper and more effective to look for simple solutions that reduce emissions, or even extract existing carbon dioxide from the air. There are many viable proposals to do this cheaply around the world, which also often help feed the world's poorest people. One outstanding example is to use a substance known as biochar to sequester carbon and increase food yields at the same time.

Biochar is an astonishing idea. Burning agricultural wastes in the absence of air leaves a charcoal composed of almost pure carbon, which can then be crushed and dug into the soil. Biochar is extremely stable and the carbon will stay in the soil unchanged for hundreds of years. The original agricultural wastes had captured CO2 from the air through the photosynthesis process; biochar is a low-tech way of sequestering carbon, effectively for ever. As importantly, biochar improves fertility in a wide variety of tropical soils. Beneficial micro-organisms seem to crowd into the pores of the small pieces of crushed charcoal. A network of practical engineers around the tropical world is developing the simple stoves needed to make the charcoal. A few million dollars of support would allow their research to benefit hundreds of millions of small farmers at the same time as extracting large quantities of CO2 from the atmosphere.

• Chris Goodall's new book, Ten Technologies to Save the Planet, is published by Profile books, priced £9.99.

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Amazon deforestation up almost 4.0 percent

Base of a 100-year-old tree in the jungle near Belem Brazil. Brazils Amazon jungles known as the lungs of the world lost almost 12000 square kilometres (4800 sq. miles) in just 12 months a rise of almost 4.0 percent new figures showed Friday.
Base of a 100-year-old tree in the jungle near Belem, Brazil. Brazil's Amazon jungles, known as the lungs of the world, lost almost 12,000 square kilometres (4,800 sq. miles) in just 12 months, a rise of almost 4.0 percent, new figures showed Friday.

The National Institute for Space Research (INPE) said the deforestation of the vast jungles due to encroaching farm exploitation, was 3.8 percent higher from August 2007 to July 2008 than in the previous 12 months.
The areas most affected were in northern Para and in the central Mato Grosso region, which is a huge producer of soya beans.

Over the past three years, the Brazilian authorities have succeeded in sharply reducing the loss of the Amazon rainforests, the biggest zone of tropical woodland on the planet.

Brazil is fighting to preserve its five million square kilometers of Amazon forest, a battle which it wants to be recognized as a service against global warming.

It argues that its efforts should be rewarded with financial input from other countries which would go to helping poor Amazon populations that might otherwise turn to cutting down trees.

But the results from 2007-2008 show that a surface equivalent to Solvenia or Israel was lost compared with the previous year.

The government had warned that the figures were likely to rise and has brought in new measures to combat the problem, including a system of fines.

It has also passed a series of agreements with soya, meat, wood and mineral producers that they will not buy illegal products.

Environment Minister Carlos Minc has said that without these measures the deforestation would have been twice as large.

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How the beat of our feet can generate power

Robin McKie

Dancefloor

Power harvesting is already being tested on disco dancefloors. Photograph: EPA

The beating of a patient's heart, the shudder of a tube train and the pounding of thousands of commuters' feet on crowded platforms are being exploited as new sources of power.

Engineers and scientists are developing tiny generators that turn the kinetic energy of everyday movements into electricity which can then power sensors or provide electricity for remote installations.

The technology, known as power harvesting, is already being tested in helicopter frames, the floors of discos and in volunteers' knee joints in order to generate electricity. In the near future, harvesters could be used to recharge iPods and mobile phones, say researchers.

'The idea is a not a new one,' admitted Dr Steve Beeby, of Southampton University. 'Self-winding watches are fitted with devices like these to recharge their batteries so they don't have to be replaced all the time. However, the latest versions are far more sophisticated and will have a much greater impact on everyday life.'

Beeby has fitted harvesters at oil refineries. Vibrations from pipes and pumps drive the devices which in turn generate electricity for sensors. These sensors provide data that show if the refinery is operating safely and effectively.

'Without these devices we would have to link our sensors with miles of cables: a hazard and a waste of money,' added Beeby who is now working on fitting power harvesters to the frames of aircraft so embedded sensors can provide data readings about metal stress.

Power harvesters are also being developed to help cardiac patients. At Imperial College, London, Dr Paul Mitcheson is working on a pacemaker that is kept constantly charged by the beating of a person's heart. Such a device, he said, could mean that pacemaker replacement operations - which are typically carried out every six or seven years - might become a thing of the past.

The idea of using human energy to power electronic devices was originally developed by Trevor Baylis for his wind-up radio more than a decade ago. Modern versions are becoming more sophisticated, however. Even the gyrations of dancers are being used to generate power at the Bar Surya in London. Crystalline harvesters under its disco floor create tiny pulses of energy each time a dancer pushes down. The electricity created this way is used to offset the bar's utility bills.

Installed on a large scale, in tube and rail stations, these underfloor harvesters could provide a considerable output of electricity. UK and US military researchers are exploring the potential of energy-harvesters that could be built into soldiers' boots to provide precious power in remote and dangerous settings.P

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Mass stranding: All whales found dead

At least 80 whales all dead after being beached on a rocky stretch of Sandy Cape in Tasmania, Novemb

The deaths come only a week after more than 60 whales of the same species became stranded on Tasmania's north-west coast. (DPI: Warwick Brennan)

There are no survivors from the latest mass whale stranding on Tasmania's west coast.

Authorities were alerted to the stranding of between 80 and 100 long-finned pilot whales on a rocky stretch of Sandy Cape yesterday.

A parks and wildlife team sent to investigate by helicopter yesterday found around 12 survivors, but most of them were already badly injured by the rocky shoreline.

A larger rescue team arrived at the remote beach this morning by four-wheel-drive to find all the whales dead.

Chris Arthur from Parks and Wildlife says he was not surprised given the condition of the survivors yesterday.

"It's an a extremely difficult site," he said.

"It is different from last weekend where the animals came ashore in sand.

"Where they are is in a rocky shore with a lot of multiple reefs and small channels.

"The animals were quite badly battered."

A group of around 16 whales believed to be from the same pod are still milling around off shore.

Rescuers will now focus their attention on trying to prevent them also becoming beached.

The deaths come only a week after than 60 whales of the same species became stranded at Anthony's Beach on the state's north-west coast.

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