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Wednesday, November 26, 2008

Solar-powered probe to view unseen parts of Jupiter

by Rachel Courtland

The Jupiter orbiter Juno will study the distribution of water in the gas giant and look for evidence of a solid core (Illustration: NASA/JPL)

The Jupiter orbiter Juno will study the distribution of water in the gas giant and look for evidence of a solid core (Illustration: NASA/JPL)

After a two-year delay, NASA has given the green light to Juno, a $1 billion, solar-powered mission to Jupiter.

Juno was originally set to launch as early as 2009, but budget constraints delayed the next step in the probe's design.

Now, funding had been approved to build the spacecraft, the agency announced on Monday. Juno will launch from Cape Canaveral, Florida, in August 2011. After reaching Jupiter in 2016, it will orbit 32 times over the course of its year-long mission.

Juno will be the second orbiter to study Jupiter. The first such probe, Galileo, circled Jupiter's equator for almost eight years before plunging into the Jovian atmosphere in 2003.

Juno, on the other hand, will take up a polar orbit around the planet, skimming the poles at an altitude of 5000 kilometres. This trajectory will afford the spacecraft a view of unseen parts of the planet.

The probe will also fly between Jupiter's atmosphere and the intense radiation belts that girdle the planet. In the radiation belts, streams of charged particles could darken the glass covering the probe's solar panels, limiting their capacity and limiting the probe's lifetime.

Search for water

Juno will carry a suite of 11 science instruments, some of which will be used to measure the planet's gravity, magnetic field, and chemical makeup.

"We're really looking at composition," says principal investigator Scott Bolton of the Southwest Research Institute in San Antonio, Texas. "We're going after the ingredients of Jupiter so we can reconstruct the recipe."

Since oxygen is the third-most abundant element in the universe and in the Sun, many planetary scientists expect to see a fair amount of water in Jupiter. But Galileo's atmospheric probe, which entered Jupiter's atmosphere in 1995, saw little evidence of water.

"The Galileo probe was expected to measure water, but it failed," says Dave Stevenson of Caltech. Some suspect little water was found because the module descended through a dry patch in Jupiter's atmosphere.

Gravity field

Juno will attempt a more global search. The probe will use radio antennae to measure light absorbed by water and ammonia at six different depths in the atmosphere.

If water is present, it could fill out the picture of how the planet formed. Since water ice is thought to dominate the dust content in the early solar system, "the water is a tracer of the solid material that was added to the planet", says Stevenson.

Coupled with measurements of the planet's magnetic and gravitational fields, scientists could begin to build up a working model of the planet and put constraints on how it formed, Stevenson says.

Jupiter's gravitational field will be mapped by detecting how the planet's tug influences Juno's velocity. Those changes will be measured by looking for shifts in the frequency of signals passed between the spacecraft and the Deep Space Network, Earth's international array of radio antennae.

Solar power

Such measurements could eventually reveal whether Jupiter has a core of heavier elements that were once rock and ice. If Jupiter has a heavy core, it would suggest Jupiter formed by 'core accretion' - by slowly accumulating solid materials before later gathering gas to build its atmosphere.

Magnetometers on the craft will be used to map the planet's magnetic field. This map could be used to infer how intense pressures in Jupiter's interior squeeze hydrogen and change how it conducts electricity.

Other far-flung spacecraft, such as the New Horizons mission to Pluto, run on electricity generated by the heat of decaying radioactive material.

But Juno will be powered by three long, hinged solar panels that will unfold after launch. With the panels unfolded, Juno will span some 20 metres across.

The craft may be the most distant spacecraft to operate off solar power. The only other contender for the title is the European Space Agency's Rosetta spacecraft, which will briefly intersect Jupiter's orbit to rendezvous with the comet 67P/Churyumov-Gerasimenko in 2014.

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Hubble offers clear view of massive stars

NASA, ESA and Jesus Maiz Apellaniz
A pair of colossal stars, WR 25 and Tr16-244, are in the open cluster Trumpler 16. This cluster is embedded within the Carina Nebula, an immense cauldron of gas and dust that lies approximately 7500 light-years from Earth in the constellation of Carina, the Keel. WR 25 is the brightest, situated near the center of the image. The neighboring Tr16-244 is the third brightest, just to the upper left of WR 25. The second brightest, to the left of WR 25, is a low mass star located much closer to the Earth than the Carina Nebula.

Very massive stars are often the hardest to see, as they're typically embedded in nebulas of gas and dust.

So it is with two of our Milky Way Galaxy's most massive stars. But the Hubble Space Telescope has just offered a better view.

The image shows a pair of colossal stars, WR 25 and Tr16-244, located within the open cluster Trumpler 16. This cluster is embedded within the Carina Nebula, an immense cauldron of gas and dust that lies 7,500 light-years from Earth. The nebula contains several ultra-hot stars, including these two star systems and the widely studied, explosive star Eta Carinae, which has the highest luminosity yet confirmed.

The stars are hot and bright, emitting most of their radiation in the ultraviolet and therefore appearing blue. They are so powerful that they burn through their hydrogen fuel source faster than other types of stars. They live fast, and they will die young. While our sun is middle-aged at 4.6 billion years, the hottest stars live only tens or hundreds of millions of years.

The stars interest astronomers because they are associated with star-forming nebulas, and they influence the structure and evolution of galaxies.

WR 25 is likely to be the most massive and interesting of the two. Its true nature was revealed two years ago when an international group of astronomers led by Roberto Gamen, then at the Universidad de La Serena in Chile, discovered that it is composed of at least two stars. The more massive is a Wolf-Rayet star and may weigh more than 50 times the mass of our sun. It is losing mass rapidly through powerful stellar winds that have expelled the majority of its outermost hydrogen-rich layers, while its more mundane binary companion is probably about half as massive as the Wolf-Rayet star, and orbits around it once every 208 days.

Massive stars are usually formed in compact clusters. Often the individual stars are so physically close to each other that it is very difficult to resolve them in telescopes as separate objects.

These Hubble observations have revealed that the Tr16-244 system is actually a triple star. Two of the stars are so close to each other that they look like a single object, but Hubble's Advanced Camera for Surveys shows them as two. The third star takes tens or hundreds of thousands of years to orbit the other two. The brightness and proximity of the components of such massive double and triple stars makes it particularly challenging to discover the properties of massive stars.

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Red tape, overruns ground satellites

By CHASE DAVIS


LOGAN, UTAH — In the high-tech satellite business, where billions flow to wealthy firms headquartered in sleek metropolitan office parks, it seems unlikely that one of the world's most sophisticated weather sensors would be built here, amid the craggy peaks of northern Utah.

Scientists say it has the power to predict tornadoes, enhance hurricane forecasts and help airlines save millions in expensive jet fuel, all by providing precise readings of the swirling winds and vapors that churn severe weather systems.

But instead of barreling through orbit more than 20,000 miles above Earth, this $100 million atmospheric camera, known as GIFTS, spent part of last summer tucked in the corner of a drab storeroom here, covered in tarp and blocking an emergency exit — a fact not overlooked by the local fire marshal, who ordered scientists to haul it someplace else.

For the sensor's creators, it has been a humbling anticlimax: Despite seven years of development and testing, millions in taxpayer dollars, and support from think tanks and governments around the world, GIFTS may never fly in space.

Instead, it provides a vivid if complex example of how bureaucracy, budget cuts and broken promises have driven many of the government's weather and climate satellites into costly and unprecedented decline.

According to congressional testimony and government officials and experts from around the world, the United States' network of weather and climate satellites is declining so severely that it may soon start losing critical data that could help predict severe storms like Hurricanes Ike and Gustav.

In the multibillion dollar arena of U.S. climate science, the GIFTS project was relatively small. But similar storylines have played out like bad sequels, as numerous satellites have been delayed, cancelled or held earthbound by cut budgets and cost overruns. Some that provide crucial information continue to operate years longer than intended, threatening to fail at any time.

"It's fair to say that the (earth) science situation is as bad as it's ever been in recent years," said Rick Anthes, president of the University Corporation for Atmospheric Research and co-chair of a government-sponsored study to determine the country's earth science priorities. "There are a lot of cheap words out there about how important science and technology are to the future of the U.S., but we're not getting the appropriations."

Congress hears dark report

The struggle has played out largely behind the scenes, in the arcane worlds of research laboratories and congressional hearings. At its center have been federal agencies such as NASA and the National Oceanic and Atmospheric Administration, which fund much of the nation's climate science and weather research.

Records and interviews show that scientists and government officials have for years warned that cuts to research budgets at both agencies could imperil the nation's satellite systems.

Congress and the Bush Administration have done little in response — a condition intensified by mounting federal debt and overruns in key programs.

"We're looking at a bailout, the war in Iraq, and a deficit budget," said Eric Barron, former dean of the University of Texas Jackson School of Geosciences and now head of a Colorado-based climate research organization. "If anything, I think the science community is a little more nervous."

Testimony given to Congress by scientists has painted a dire picture.

A 2005 report by a government-commissioned panel of earth scientists warned Congress that the nation's network of Earth-observing satellites was "at risk of collapse."

In 2006, the testimony of former astronaut and retired Marine Corps Gen. Charles F. Bolden Jr. likened NASA's attempts to adequately support its myriad directives to "trying to fit 15 pounds of stuff into a 5-pound sack."

A 2007 report sponsored by the National Academy of Sciences estimated that 40 percent of nation's more than 100 climate sensors could go dark by 2010 — not enough to blind forecasters, but enough to weaken the data used by researchers who rely on history to gauge trends.

Climate researchers — the scientists working to figure what effect global warming may one day have on Gulf Coast hurricanes, for example — count on regular, uninterrupted satellite readings to gauge whether the environment is changing. If a critical satellite fails, scientists will be left poorly prepared to predict events that could cause hurricanes and droughts.

Projects hit the wall

Many scientists agree that NASA, NOAA and other agencies are doing the best they can with the money they have been given, despite the costs and uncertainty of building cutting-edge satellite technology.

For example, the multibillion-dollar satellite system known as NPOESS has continued to progress, but some scientists worry that overruns on the project have forced NOAA to scale back other research programs, Barron and others said.

NPOESS and another large weather satellite project, GOES-R, will together cost more than $20 billion by some estimates. And according to federal audits, both are already years behind schedule and billions over budget.

Another widely publicized project known as DSCOVR, was scrapped in 2006 despite more than $100 million being spent to develop it. The satellite would have measured how well the Earth reflects the sun's rays. Its creator, Francisco Valero of the Scripps Institution of Oceanography in San Diego, said he blames political infighting for its demise.

"We take for granted that we can now know the weather four or five days in advance," said retired National Weather Service Director Joe Friday, who now consults for the NPOESS program. "If we don't have those satellites, we'd barely be back to understanding what the weather will do two or three days from now."

NASA, which plays a leading role in building many of the country's weather and climate satellites, has trimmed tens of millions from its earth science programs since at least 2004, when the agency was charged with retiring the space shuttle and building a new set of space vehicles to return humans to the moon. President George Bush agreed to supplement that effort with billions in new funding.

But the money never came.

After years of complaints by scientists and policymakers, Congress and the White House this fall enacted a bill that could boost NASA's budget by about $3 billion next year, a significant increase for an agency with a current budget of $17 billion. Still, the money may come too late to save some projects — among them, the star-crossed satellite known as GIFTS.

A 10-year odyssey

GIFTS' journey from state-of-the-art storm-tracker to warehouse fire hazard began nearly a decade ago, in universities and offices from Langley, Va., to the sloping peaks of northeast Utah.

When it was approved in 1999, the project was hailed as experimental but revolutionary. The sensor was ambitious, but so was its price tag: more than $250 million, spread across four government agencies. Foremost among the investors was NASA, which committed roughly $100 million.

The GIFTS sensor was a cutting-edge marriage of new technology with a sensing technique conceptualized more than 100 years ago. The result would have been more rapid, detailed measurements of the environmental conditions that drive severe weather, leading to earlier warnings and more accurate forecasts.

The principal investigator of the project, Bill Smith, described the sensor as a "revolutionary" three-dimensional movie camera that would provide real-time data on wind, temperatures and vapors that could be fed into models that predict severe weather.

"It can see tornadoes forming a couple hours before you can even see them on radar," he said last summer. "It's the first of its kind."

The GIFTS instrument was widely seen as a tool that could advance modern weather science, perhaps becoming a fixture on future generations of weather satellites.

But before it could be launched, the program unraveled.

It started in 2002, when the Navy, which had agreed to handle the satellite's launch, pulled money from GIFTS in order to accelerate another satellite project, a spokesman said at the time. With millions already invested, NASA began looking for partner agencies to shoulder the launch burden, which by some estimates exceeded the cost of the sensor itself.

They came close, but never close enough.

Several foreign governments, including Russia, expressed interest, as did the influential World Meteorological Organization, but nobody could put up enough money to get the satellite ready for space. In 2005, an independent panel of scientists testified to Congress that NASA and NOAA should invest in completing the project, but neither agency acted upon the recommendation.

Among the most decisive words Smith received from NASA came in 2006, when he was forwarded a letter from space agency Administrator Michael Griffin to his counterparts in the Russian Federal Space Agency. It read, in part: ''Due to funding constraints, NASA does not intend to complete a flight-qualified instrument.''

So seven years after it began with so much promise and ambition, GIFTS was sealed in a nitrogen-filled capsule slightly smaller than a Volkswagen Beetle and placed in storage, where it has stayed as its creators have fought, so far in vain, to fly in space.

chase.davis@chron.com

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Bachelor Pads of the International Space Station

By Ed Grabianowski

You're stuck for months inside a cramped tin can with a bunch of total strangers, with no gravity, fresh food or World of Warcraft. And yeah, you're forced to drink the recycled sweat of your fellow astronauts (or your own urine). But that doesn't mean you can't have your own stylin' bachelor (or bachelorette) pad in space. Check out the new digs being delivered to the ISS.

Let's be honest for a minute - living on the ISS pretty much sucks. It's like the college dorm from hell (after some frat boys broke in and stole all the gravity for the weekend). Terrible food. Noisy. Some random people you barely know constantly breathing down your neck. And absolutely zero privacy. If it wasn't for the sheer awesomeness of being in space, no one would go.

NASA spent $30 million developing new private rooms for the orbital platform in an effort to make things more bearable, and it looks like they succeeded admirably. Four of the new rooms will be installed (two were delivered by Endeavor, with two more soon to come). Each one is tiny, like more of a closet than a room, but it's remarkably soundproof and has a door. There are hooks for a sleeping bag, a foldout laptop table (with foot anchors, so astronauts can sit comfortably), and velcro on the walls for attaching family photos and girly calendars.

Even though these new ISS cabins are roughly the size of a bathroom stall, I think they will represent a huge improvement in quality of life for the astronauts. After all, they've got 250 lbs. of insulating polyethlene to protect them from dangerous solar flare radiation. What bachelor pad can boast that?

Sadly, the ISS cabin doors don't lock, and I don't think NASA has developed a zero-G version of the sock-on-the-doorknob. Image by: NASA.

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Researchers identify how binge drinking may drive heart disease

Irregular, heavy drinking pattern clogs blood vessels

As the holidays arrive, a group of researchers has identified the precise mechanisms by which binge drinking contributes to clogs in arteries that lead to heart attack and stroke, according to a study published today in the journal Atherosclerosis. The works adds to a growing body of evidence that drinking patterns matter as much, if not more, to risk for cardiovascular disease than the total amount consumed.

According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), going on a 'binge' means having five or more drinks for men, and four or more drinks for women, in two hours. Many studies suggest that an irregular pattern of heavy drinking brings about a two-fold increase in risk for a fatal heart attack, even as moderate drinking has been shown to reduce risk (the red wine effect). About 65 percent of Americans drink alcohol, with 15 percent reporting binge patterns in a national survey of problem drinkers.

Alcoholic beverages contain ethanol, which is mostly converted into acetaldehyde once in the human system at 'binge' levels, with the levels of acetaldehyde remaining high for many hours after the binge has ended. The current study clarified for the first time that binge levels of acetaldehyde cause an important type of immune cell, the monocyte, to become better able to stick to blood vessel walls, an important step in initiating atherosclerotic disease. Clarifying these mechanisms promises to empower the design of new treatments to counter the effects when combined with lifestyle change, researchers said.

In the past, experts believed that atherosclerosis developed when too much cholesterol clogged arteries with fatty deposits called plaques. When blood vessels became completely blocked, heart attacks occurred. Now most believe that the reaction of the body's immune system, more than the build-up itself, creates heart attack risk. Vessel walls mistake fatty deposits for intruders, akin to bacteria, and call for help from the immune system. Among other cell types, monocytes arrive with the goal of preventing infection, but end up causing inflammation that drives blood vessel blockage.

"Factors like binge-drinking have been linked to increased risk for heart disease, and the newer inflammatory model is beginning to explain how," said John Cullen, Ph.D., assistant professor in the Department of Surgery at the University of Rochester Medical Center. "One of our experiments found that acetaldehyde, at levels found in the blood after binge drinking, increased the number of monocytes that can adhere to cells lining blood vessels by 700 percent," said Cullen, who led the study.

Health psychologists argue that motivating people to stop binging depends upon their belief that it is harming them. Thus, the authors of the current study hope the results empower public health campaigns that discourage binge drinking.

Study Details

In between infections and injuries, dormant monocytes ride along with the bloodstream until they "realize" they are passing by part of a blood vessel wall close to the site of an injury or infection, or in the case of atherosclerosis, the site of cholesterol buildup. At this point, adhesion molecules on the monocyte surfaces unfold and grab onto key proteins on the surface of blood vessel wall cells, resisting the surrounding blood flow.

Whey they arrive on the scene, monocytes send out tethers, like anchors that snag the vessel wall. Once the monocyte swings close to the wall on its tether, it can then roll along the wall, getting stickier and sticker until it sticks in place permanently. Without this step, a major part of the immune component of atherosclerosis could not get underway.

In the current study, the team examined the effects of acetaldehyde on the ability of monocytes to home in on, tether to and roll along cells lining blood vessel walls. Researchers made cultures of the cells lining blood vessels (e.g. human umbilical venous endothelial cells (HUVEC)), and of two types of monocytes that stick to those vessel-lining cells when activated (e.g. primary blood monocytes (PBM) and THP-1 monocytes). The team then treated all cell cultures with acetaldehyde at varying doses (0.1󈞅 µM) known to correlate with binge drinking for six hours.

Specifically, the current study found that acetaldehyde stimulated monocyte adhesion through its effect on three important proteins, CCR2, P-selectin, and tumor necrosis factor alpha (TNFα).

Several studies provide compelling evidence for a direct role of the monocyte chemoattractant protein-1 (MCP-1) receptor called chemokine (C-C motif) receptor 2 (CCR2) in the rush of monocytes to blood vessel walls as part of atherosclerosis. CCR2 is a receptor, a protein that occurs on the surfaces of monocytes that links up with MCP-1 as part of the signal that brings monocytes homing in on diseased blood vessel walls. The current study found that the addition of acetaldehyde to monocytes increased by more that twofold the number of cells with CCR2 expressed on their surfaces.

P-selectin is a cell adhesion molecule (CAM) that, upon receiving the right signal, quickly rises to the surface of the cells lining blood vessels (endothelial cells) to help monocytes grab them. The team found a 40 percent increase in endothelial cells showing P-selectin on their surfaces when exposed to acetaldehyde, and a 50 percent increase in the density of P-selectins expressed on the surface of each cell.

The study also found that the genetic expression of TNFα, an important driver of several aspects of inflammation in blood vessels, in endothelial cells increased by about 2.5 fold in the presence of acetaldehyde (10µM). Given the above results, it is not surprising that the addition of acetaldehyde increased the overall adhesion of primary blood monocyte to endothelial cells by approximately 250 percent for 0.1 µM acetaldehyde, and 700 percent for 25µM acetaldehyde, when compared to controls.

When endothelial cells were subjected to a technique that shut down the genes that code for both P-selectin and TNFα prior to the addition of acetaldehyde, the ability of acetaldehyde to cause increased monocyte adhesion was reduced by 90 percent. These results argue strongly that acetaldehyde has its effects on monocytes primarily through these proteins.

Along with Cullen, the work was led in Rochester by Eileen Redmond, David Morrow, Sreenath Kundimi and Carol Miller-Graziano within in the Department of Surgery at the Medical Center. The work was supported in part by grants from the American Heart Association and the National Institutes of Health.

"Our study demonstrates for the first time that physiologically relevant concentrations of acetaldehyde can initiate several key steps involved in the monocyte recruitment cascade, specifically through P-selectin, CCR2 and TNFα," Cullen said. "We hypothesize that, following alcohol consumption, there is a delicate equilibrium between the effects of alcohol and its metabolite, acetaldehyde, on blood vessel walls. Further studies are underway to confirm that these actions of acetaldehyde underlie, in part, the detrimental effects of binge drinking on cardiovascular disease. "

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Cyborg leaf makes working solar power plant

by Colin Barras

A rust-coloured sheet of porous gold covered in an invisible coating of plant proteins provides a whole new way to tap solar energy (Image: Peter Ciesielski)

A rust-coloured sheet of porous gold covered in an invisible coating of plant proteins provides a whole new way to tap solar energy (Image: Peter Ciesielski)


Gold leaf doesn't grow on trees, but it can now harvest power from the Sun. A team of US chemical engineers has extracted photosynthetic molecules from plants and attached them to thin sheets of gold, creating a photosynthesising cyborg.

Organisms have been photosynthesising for at least 3.5 billion years, and over that time have developed elegant combinations of protein and light-absorbing dyes to help convert sunlight into power.

Rather than reinventing the wheel, Kane Jennings and Peter Ciesielski's team at Vanderbilt University in Nashville, Tennessee, decided to take those proteins to build their own photosynthetic devices.

The idea grew from the work of Elias Greenbaum at the Oak Ridge National Laboratory, also in Tennessee, who in the late 1990s showed that a protein complex, known as PS1, extracted from spinach leaves remained active when immobilised on a gold surface.

Artificial leaf

Since then the process for extracting PS1 from plants has been perfected, says Jennings, laying the ground for his group to use those light-harvesting proteins to make an artificial leaf.

Jennings and Ciesielski made their device using commercially available gold-silver alloy leaf.

Concentrated nitric acid was used to dissolve away the silver to leave gold leaf with nanoscale pores. This gave it a high surface area that allows a large amount of PS1 to be attached. It also made the leaf thin enough for light to penetrate. The finished material was stretched over a thicker gold substrate for support.

PS1 complexes were attached to the leaf by first coating the porous gold in thiols - chemical molecules that have a free end able to form strong bonds with the proteins.

When the complete cyborg leaf is placed under light, the PS1 complexes generate electrons that flow into the gold and can be harvested as electric current.

In a living plant, those electrons would be used to reduce compounds as part of a chemical chain that produces new energy stores in the form of carbohydrates.

Low power

The most rigorously tested artificial leaf produces a current of around 800 nanoamps per square centimetre. That is far from efficient enough to be economic, but the researchers are already experimenting with a new model.

"We are currently investigating PS1 films up to one micrometer thick," says Jennings. "These films can generate up to 2 microamps per centimetre square, and can power an inexpensive calculator."

Although the cyborg devices are still far behind the best silicon-based solar cells the new approach may become more competitive in future. The new design is relatively simple, and sourcing cheap plant leaves and a suitable substrate to make cyborg leaves from should be easy.

The system is still too delicate to be exposed to direct sunlight, which would burn out the PS1 proteins. Finding a way to protect them, and building leaves that pack in more of them will improve output further. That might even turn the artificial leaves green - they currently appear rusty red due to the properties of the nanoporous gold.

Greenbaum is impressed with the direction his original discovery has taken. "This is very nice work by an outstanding group," he says. "The results represent an important research advance in bio-inspired solar energy conversion."

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Worm glue could repair human bones

SALT LAKE CITY, Nov. 25 (UPI) -- University of Utah researchers say they've created synthetic sea worm glue that has potential for use in repairing shattered bones.

The glue is a synthetic version of the glue that sandcastle worms use to build homes from bits of sand and shell. Russell Stewart, associate professor of bioengineering, said the glue could be used to repair shattered bones in knees and joints, as well as the face.

"When you break the top of a bone in a joint, those fractures are difficult to repair because if they are not aligned precisely, you end up with arthritis and the joint won't work anyway," Stewart said in a university release. "So it's very important to get those pieces aligned as well as possible."

The report is published in the journal Macromolecular Biosciences.

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Wind Farms Could Change Weather

Analysts estimate it would take at least 260,000 turbines, each 300 feet tall, to meet the United States' electricity needs. These turbines are in King City, Mo. Credit: MU Cooperative Media Group, Steve Morse photo

By Robert Roy Britt

A new study suggests that massive wind farms could steer storms and alter the weather if extensive fields of turbines were built, according to a news report.

It is not the first study to come to this conclusion.

The new research is an interesting "what if," but the installation of large wind turbines would have to be taken to the extreme to have the global effects portrayed.

The scientists, Daniel Barrie and Daniel Kirk-Davidoff of the University of Maryland, calculated "what might happen if all the land from Texas to central Canada, and from the Great Lakes to the Rocky Mountains, were covered in one massive wind farm," according to Discovery News. The result of such an unlikely installation: a real serious Butterfly Effect.

Such massive wind farming would slow wind speeds by 5 or 6 mph as the turbines literally stole wind from the air. A ripple effect would occur in the form of waves radiating across the Northern Hemisphere that could, days later, run into storms and alter their courses by hundreds of miles.

The researchers "acknowledged the hypothetical wind farm was far larger than anything humans are likely to build," according to the Web site, but if Department of Energy projections for wind farming are met by 2030 (for the country to get 20 percent of its electricity from wind), "it could probably have an effect," James McCaa of 3Tier, Inc., a renewable energy forecasting company based in Seattle, is quoted as saying.

In 2004, two separate groups of scientists did similar calculations.

One group found the opposite effect.

Somnath Baidya Roy of Princeton University and colleagues simulated the effect of extensive wind farms on local weather. They found a drying and warming effect in the morning that would warm the air across moist and cool overnight soil, causing the local wind speed to increase slightly.

Also in 2004, David Keith of the University of Calgary and his colleagues estimated the drag from wind farms if they covered 10 percent of the Earth's land surface. They concluded that global cooling would occur in polar regions and global warming would result in temperate regions such as North America at about 30 degrees North latitude.

When that study was released, Keith had an interesting take on the possibility: "The message here is climate change, but that doesn't equal global warming," Keith said. "It's possible this would have benefits," by working against the atmospheric effects of fossil fuel consumption on global climate, he said.

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Oceans Growing Acidic 10 Times Faster Than Expected

By Dan Shapley

Dead, Eroded Mussels
Eroded mussel shells are possible symptoms of stress from declining ocean pH and increasing acidity.
Photo: C.A. Pfister, University of Chicago

The world's oceans are growing acidic at a rate 10 times as fast as predicted, according to a new University of Chicago study published in the Proceedings of the National Academy of Sciences.

The study also reinforced what we already knew: Ocean acidification results from the same thing that is driving global warming: carbon dioxide emissions. Oceans absorb the lion's share of our pollution, but not without consequence. As the carbon dioxide is absorbed, it forms carbonic acid, which at certain thresholds can prevent marine life from forming calcium carbonate shells. The most likely target will be Arctic plankton that form the basis for the entire food web, but ultimately coral and many other species will be affected, either directly or indirectly through the loss of food.

Further, as oceans become saturated, they may absorb less carbon dioxide, leaving more of it to fill up the atmosphere, where it helps trap the sun's heat near the Earth's surface, fueling global warming.

The new study is based on nearly 25,000 measurements taken over eight years, and amounts to one of the most thorough studies to account for rising acidity. It also documented, on Tatoosh Island in the Pacific Ocean off the coast of Washington, the effects of acidification: The number of mussels and stalked barnacles dropped as acidity increased, while populations of other smaller-shelled and nonshelled creatures increased.

The study adds to a growing list of dire assessments and predictions for the oceans. A recent assessment by a Scripps Institution of Oceanography oceanographer, for instance, predicted that overfishing, acidification, habitat destruction, global warming and nutrient runoff from farming would conspire to drive oceans back toward a primordial state, dominated by the likes of algae and jellyfish.

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Vatican set to go green with huge solar panel roof

By Philip Pullella

VATICAN CITY (Reuters) - The Vatican was set to go green on Wednesday with the activation of a new solar energy system to power several key buildings and a commitment to use renewable energy for 20 percent of its needs by 2020.

The massive roof of the Vatican's "Nervi Hall," where popes hold general audiences and concerts are performed, has been covered with 2,400 photovoltaic panels -- but they will not be visible from below, leaving the Vatican skyline unchanged.

The new system on the 5,000 square meter roof will provide for all the year-round energy needs of the hall and several surrounding buildings, producing 300 kilowatt hours (MWh) of clean energy a year.

The system, devised by the German company SolarWorld, will allow the 108-acre city-state to cut its carbon dioxide emissions by about 225,000 kilograms (225 tonnes) and save the equivalent of 80 tonnes of oil each year.

The Holy See's newspaper said on Tuesday that the Vatican planned to install enough renewable energy sources to provide 20 percent of its needs by 2020, broadly in line with a proposal by the European Union.

The 1971 Nervi Hall is named after the renowned architect who designed it, Pier Paolo Nervi, and is one of the most modern buildings in the Vatican, where most structures are several centuries old. The hall can hold up to 10,000 people.

It has a sweeping, wavy roof which made the project feasible and the solar panels virtually invisible from the ground. Church officials have said the Vatican's famous skyline, particularly St Peter's Basilica, would remain untouched.

An editorial in Tuesday's newspaper appealed for greater use of renewable energy.

"The gradual exhaustion of the ozone layer and the greenhouse effect have reached critical dimensions," the newspaper said.

By producing its own energy the Vatican will become more autonomous from Italy, from where it currently buys all its energy. The Vatican is surrounded by Rome.

Pope Benedict and his predecessor John Paul put the Vatican firmly on an environmentalist footing.

Benedict has made numerous appeals for the protection of the environment. The Vatican has hosted a scientific conference to discuss the ramifications of global warming and climate change, widely blamed on human use of fossil fuels.

Environmentalists praised the pope last year after he made a speech saying the human race must listen to "the voice of the earth" or risk destroying the planet.

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