Scinence Daily

Animals in Space

Wed, 30 Jul 2008 10:25:59 GMT

Animals in Space

The First
In 1957, a Soviet dog named Laika became the first living creature to orbit the Earth. Originally a stray, Laika was selected over two other trainees. Though she died a few hours after launch, her trip proved that a living passenger could survive being launched into orbit and endure weightlessness.

Space Dogs
Handlers at the Soviet Academy of Sciences show off some of the dogs in their space program. During the 1950s and 1960s, the Russians launched missions that included passenger slots for at least 57 dogs. The number of animals that actually reached space is smaller, as several dogs went more than once.

Little Guy
A squirrel monkey, his body swathed in protective silicon rubber padding, is strapped into a capsule as part of a training exercise for spaceflight. A comrade of his known as Gordo was similarly secured for a 1958 fifteen-minute flight that ascended to a height of 310 miles. Though it is believed that Gordo survived the entirety of his flight, the parachute on his craft failed to open and he and his capsule were lost at sea.

Able and Baker
The first two monkeys to survive their trip into space are presented at a NASA press conference in 1959. Able, on the left, a seven-pound rhesus monkey, and Baker, an 11-ounce squirrel monkey from Peru, withstood forces 38 times the normal pull of gravity and endured weightlessness for about 9 minutes during their historic flight. Able died four days after returning to earth during a relatively simple surgery to remove an infected electrode. Baker lived until 1984.

Chimp in Training
In early 1961, just a few months before Soviet cosmonaut Yuri Gagarin launched into orbit, NASA was using chimps to help iron out the kinks in its Mercury program. Approximately 20 of them were trained at Holloman Air Force Base in New Mexico on equipment simulating space flight, like the rocket sled, above.

Timed Task
The chimps in the Holloman training program were taught how to do simple tasks in response to electric lights and sounds. Jim, the chimp whose efforts are photographed here, has made a mistake: the experiment calls for him to hit the odd shape, in this case, the circle in the middle.

Capsule Position
The chimps in the Holloman program were prepared for launch in a Mercury capsule, similar to the one above.

In Space
Two chimps from the Holloman program were successfully launched into orbit. A chimp named Ham, whose journey lasted 16 minutes and 59 seconds, took off in January 1961. His comrade, Enos, blasted off ten months later, above, for a journey that circled the Earth two times.

Safe Return
After his brief journey into orbit, Ham splashed down in the Atlantic Ocean and he and his capsule were recovered by a rescue ship. He only suffered a bruised nose during his flight.

Manned Space Flight
Once Ham and Enos had completed their journeys, NASA felt ready to send a human into orbit. On February 20, 1962, John Glenn became the first American to circle the Earth.

UN: Fewer AIDS Deaths Globally

Wed, 30 Jul 2008 10:20:57 GMT

UN: Fewer AIDS Deaths Globally

Tuesday, Jul. 29, 2008 By AP/MARIA CHENG

An HIV positive patient, sleeps in her room in the eastern Indian city of Kolkata , India

Parth Sanyal / REUTERS

(LONDON) — Fewer people are dying of AIDS, more patients are on HIV medication and the global AIDS epidemic is stable after peaking in the late 1990s.

But the United Nations AIDS agency warned in its yearly report Tuesday that governments will need to continue setting aside millions of dollars for AIDS in the coming decades as patients live longer on AIDS treatment.

"We've achieved more in the past five years than in the previous 20 years," said Peter Piot, the agency's executive director. "But if we relax now, it would be disastrous. It would wipe out all of our previous investments."

UNAIDS estimates the number of AIDS case worldwide at 33 million; its previous estimate of 40 million was revised last year because of changes to how it counts cases.

Countries in sub-Saharan Africa including South Africa, Botswana and Swaziland, remain the center of the AIDS epidemic. The region has about 67 percent of all people infected with HIV and 72 percent of all AIDS deaths.

Outside sub-Saharan Africa, AIDS mainly affects drug users, gay men and sex workers.

Officials estimate that 2 million people died from AIDS last year, down from approximately 2.2 million in 2005.

The most dramatic figures are in treatment: The number of people on AIDS medication jumped by 10 times in the last six years, with some 300,000 taking AIDS drugs in 2003 compared to about 3 million in 2007. AIDS drugs have become much cheaper and more available because of a variety of government and private programs.

But millions of others still do not have access to the drugs, and those who do will need to remain on them to stay alive.

Still, millions of new cases of HIV infection are reported every year, the agency said. HIV is rising in several countries beyond Africa, including China, Germany, Indonesia, Russia and Britain, according to the report, which was issued in advance of next week's international AIDS conference in Mexico City.

The good news is that the global number of new infections was down to about 2.7 million people in 2007 from a peak of about 5 million new cases annually in the early 2000s.

However, the report — based on government data from 147 countries — warned there could be future waves of infection. The agency said it would be difficult to predict whether the AIDS epidemic might spike again.

Experts said it's too early to stop worrying about AIDS.

"I'm not sure we will ever get to a point where we can say this is not a public health problem," said James Chin, a clinical professor of epidemiology at the University of California, Berkeley.

Last week, the U.S. government tripled the amount of money it will spend on AIDS and other diseases around the world to $48 billion over five years.

"The objective of AIDS programs is to provide access to medication to everyone who needs it," Chin said. "Until that's accomplished, this won't go away."

The slow decline of AIDS-related deaths is "dismally disappointing," said Selina Lo, medical coordinator for Medecins Sans Frontiere's Access to Essential Medicines campaign. The group also is known as Doctors Without Borders.

She called it evidence that strategies need to change.

Some experts said health officials know what to do — but still aren't doing things like spending more money on prevention.

"We just don't know how to get governments to do nice things for junkies, sex workers and gay boys," said Elizabeth Pisani, a former UNAIDS epidemiologist who wrote a book about the mistakes made in AIDS programs.

Children: Bacteria Linked to Lower Asthma Rates

Wed, 30 Jul 2008 10:18:47 GMT

Children: Bacteria Linked to Lower Asthma Rates

By BINA VENKATARAMAN

Published: July 29, 2008

Common bacteria that have lived in human stomachs for generations are associated with lower rates of childhood asthma, researchers are reporting.

Their study, to appear on Aug. 15 in The Journal of Infectious Diseases, does not prove that the microflora, Helicobacter pylori, actually help protect children from asthma. It may be that asthmatics do not host the bacteria for other reasons.

Still, the recent study, conducted by researchers at New York University School of Medicine and the Veterans Affairs Medical Center in New York, found that children who carried H. pylori were 40 percent less likely to have asthma before age 5. And children ages 3 to 13 who had the bacteria were 60 percent less likely to report that they had asthma at the time of the study. The study relied on interviews with individuals and their families to determine whether the children had asthma.

Antibiotics kill helpful bacteria as well as harmful ones, and previous research has linked antibiotic use in children with higher risk for asthma.

“H. pylori is disappearing, and this is a fact that probably cannot be changed,” said Dr. Yu Chen, the lead author of the study. “But it’s important to realize that bacteria that have been living with us for millions of years may actually have some beneficial qualities.”

Is There a Laziness Gene?

Wed, 30 Jul 2008 10:16:35 GMT

Is There a Laziness Gene?

Wednesday, Jul. 30, 2008 By DEIRDRE VAN DYK

Tetra Images / Corbis

Have you ever wondered why you can't get off the couch and exercise — despite paying for an expensive gym membership, despite your New Year's resolutions, even despite the doctor's scolding at your last check-up? Turns out that your inertia may be coded right into your genes.

Based on some intriguing, preliminary studies in animals, J. Timothy Lightfoot, a kinesiologist, and his team at University of North Carolina, Charlotte, suggest that genetics may indeed predispose some of us for sloth. Using mice specially bred and selected according to their activity levels, Lightfoot identified 20 different genomic locations that work in tandem to influence activity levels in mice — specifically, how far the animals will run. Lightfoot's team is the first to identify these genetic areas, and the first to figure out that they function in concert. The researchers say the areas they found on the mouse genome may have analogs in humans, and the UNC team is now gearing up to conduct a similar study in men and women. "We have put forward a fairly complete genomic map of the areas that are associated with regulation of physical activity," says Lightfoot, whose study is published in the current issue of the Journal of Heredity.

Lightfoot, who originally wanted to coach college basketball and is himself an avid athlete, began studying activity levels as a way to try to figure out why, given all we know about the overwhelming health benefits of physical activity, so many people still choose not to exercise. A lecture at Johns Hopkins about genetics and lung disease served as Lightfoot's eureka moment, and he became interested in studying genes as our prime mover. For the new study, Lightfoot and his team bred two strains of mice — active and inactive. Researchers then cross-bred two generations of the active and inactive mice, ending up with a study group of 310 genetically mixed offspring. At about 9 weeks old, each mouse was housed in an individual cage and given an exercise wheel. Researchers measured how far, how long and how fast the animals ran every day for three weeks, at the end of which the mice were genotyped.

Exercise-prone mice put in a good 5 to 8 miles per day (the equivalent of an average man running 40 to 50 miles a day), versus 0.3 mile per day for inactive mice. While the exercise wheels of the activity-prone mice would turn all night, some of the sedentary mice devised ingenious ways to avoid activity. One stuffed wood shavings around the wheel and turned it into a bed; one used it as an, ahem, toilet; and one climbed on top of her wheel only to get a better look at the overhead sensors tracking her movements.

Although the animals' activity levels could not be entirely attributed to genes, researchers calculated that heredity accounted for about 50% of the differences in activity. They also found that activity-promoting genes were dominant traits in 75% of the exercise-loving mice. (Researchers don't know yet how often the activity-inclined genotype would naturally occur; Lightfoot says he found a fairly continuous range of activity levels, from extremely active to very low active, in about 30 mice strains he tested.) "When we used to talk about activity, it was whether or not people decided to be active," says Lightfoot. "Now it's clear that there's an inherent drive as to whether one is active or not active."

Exactly how that drive plays out in the body is still a mystery. There are two theories, Lightfoot says: genes may affect either the way muscles work — perhaps causing them to use energy more efficiently and preventing fatigue — or some higher-order biochemical circuit in the brain, such as levels of the neurotransmitters dopamine or serotonin. Researchers have examined the muscle tissue of the mice in the study, however, and early data, which has not yet been published, suggests there's no difference in their function. So researchers' best guess is that the drive to exercise is at least partly influenced by brain chemicals — a reasonable hypothesis, given that dopamine or serotonin plays a significant role in several human drives and behaviors, including hunger, addiction, mood and movement disorders like Parkinson's disease.

Chemistry is not destiny, of course. Lightfoot hopes to use his research to help determine which patients may need a bigger boost to get moving — he thinks that perhaps close supervision by trainers or rewards for exercising will encourage genetic lazybones to get the gym. And maybe one day, he speculates, there might even be a drug to compensate for what your genes won't give you. A drug that makes you want to exercise? Now, that's a pill worth swallowing.

Could Metals Help Treat Cancer?

Wed, 30 Jul 2008 10:11:55 GMT

Could Metals Help Treat Cancer?

ScienceDaily (July 30, 2008) — A collaboration between chemists and biologists has made it possible to identify the effects of a new class of molecules, polyoxometalates (1), primarily composed of metals and oxygen. These molecules are very powerful inhibitors of a specific protein kinase, CK2, an enzyme that is overactive in a number of cancers. The enzyme's instrumental role in controlling cell proliferation and survival makes it an important target in the search for new medications.

Structure of the protein kinase CK2 (left) and the structures of different polyoxometalate (POM) molecules (right). (Credit: Copyright B. Hasenknopf)

These results have just been published in the journal Chemistry and Biology by chemists from the Institut de chimie moléculaire (CNRS / UPMC) and biologists from the Institut de recherche en technologies et sciences pour le vivant (iRTSV, CEA de Grenoble / CNRS / Inserm.)

Phosphorylation enzymes (2) , which include the protein kinase CK2, play a critical role in controlling cell proliferation. Deregulated protein kinase activity is implicated in a number of cancers, which has led to a recent surge in research on molecules that can inhibit the activity of these enzymes. The currently known CK2 inhibitors are all organic compounds that neutralize enzymatic activity by binding to its active site (3).

The contribution of the study carried out by the researchers at the Institut de chimie moléculaire and the Institut de recherche en technologies et sciences pour le vivant was to reveal a new class of CK2 inhibitors. The new inhibitors are inorganic molecules, polyoxometalates (POMs), primarily made up of metals (molybdenum and tungsten) and oxygen. They are the most powerful CK2 inhibitors yet discovered, working at very low (nanomolar) concentrations. In addition, the researchers showed that the mode of action of POMs, although not yet fully understood, is completely new. Unlike organic inhibitors, POMs do not bind to the active site of the enzyme.

This work opens up several areas for further research: clarifying the mechanism of action of these new molecules, finding the minimum molecular entity that can inhibit enzyme activity, and finally, given its importance in the health field, improving knowledge of how the enzyme CK2 works. In the longer term, these results could pave the way for new approaches to developing anti-cancer drugs.

Notes:

(1) Polyoxometalates are anionic inorganic metal oxide structures that have valuable catalytic properties.

(2) Phosphorylation enzymes called protein kinases can attach a phosphate group to proteins that may be inactive enzymes. The addition of the phosphate group can activate these “silent” enzymes. Protein kinases thus play a central role in controlling the activity of numerous enzymes in the cell.

(3) The active site of an enzyme is a particular region where the substrates bind together and enzymatic reactions takes place.

Watching A 'New Star' Make The Universe Dusty

Wed, 30 Jul 2008 10:07:29 GMT

Watching A 'New Star' Make The Universe Dusty

ScienceDaily (July 27, 2008) — Using ESO's Very Large Telescope Interferometer, and its remarkable acuity, astronomers were able for the first time to witness the appearance of a shell of dusty gas around a star that had just erupted, and follow its evolution for more than 100 days.

Artist's impression of the shell as deduced from the observations made in the mid-infrared (in the visible, it is almost opaque), using ESO's Very Large Telescope Interferometer.

This provides the astronomers with a new way to estimate the distance of this object and obtain invaluable information on the operating mode of stellar vampires, dense stars that suck material from a companion.

Although novae were first thought to be new stars appearing in the sky, hence their Latin name, they are now understood as signaling the brightening of a small, dense star. Novae occur in double star systems comprising a white dwarf - the end product of a solar-like star - and, generally, a low-mass normal star - a red dwarf. The two stars are so close together that the red dwarf cannot hold itself together and loses mass to its companion. Occasionally, the shell of matter that has fallen onto the ingesting star becomes unstable, leading to a thermonuclear explosion which makes the system brighter.

Nova Scorpii 2007a (or V1280 Scorpii), was discovered by Japanese amateur astronomers on 4 February 2007 towards the constellation Scorpius ("the Scorpion"). For a few days, it became brighter and brighter, reaching its maximum on 17 February, to become one of the brightest novae of the last 35 years. At that time, it was easily visible with the unaided eye.

Eleven days after reaching its maximum, astronomers witnessed the formation of dust around the object. Dust was present for more than 200 days, as the nova only slowly emerged from the smoke between October and November 2007. During these 200 days, the erupting source was screened out efficiently, becoming more than 10,000 times dimmer in the visual.

An unprecedented high spatial resolution monitoring of the dust formation event was carried out with the Very Large Telescope Interferometer (VLTI), extending over more than 5 months following the discovery. The astronomers first used the AMBER near-infrared instrument, then, as the nova continued to produce dust at a high rate, they moved to using the MIDI mid-infrared instrument, that is more sensitive to the radiation of the hot dust. Similarly, as the nova became fainter, the astronomers switched from the 1.8-m Auxiliary Telescopes to their larger brethren, the 8.2-m Unit Telescopes. With the interferometry mode, the resolution obtained is equivalent to using a telescope with a size between 35 and 71 metres (the distance between the 2 telescopes used).

The first observations, secured 23 days after the discovery, showed that the source was very compact, less than 1 thousandth of an arcsecond (1 milli-arcsecond or mas), which is a size comparable to viewing one grain of sand from about 100 kilometres away. A few days later, after the detection of the major dust formation event, the source measured 13 mas.

"It is most likely that the latter size corresponds to the diameter of the dust shell in expansion, while the size previously measured was an upper limit of the erupting source," explains lead author Olivier Chesneau. Over the following months the dusty shell expanded regularly, at a rate close to 2 million km/h.

"This is the first time that the dust shell of a nova is spatially resolved and its evolution traced starting from the onset of its formation up to the point that it becomes too diluted to be seen", says co-author Dipankar Banerjee, from India.

The measurement of the angular expansion rate, together with the knowledge of the expansion velocity, enables the astronomer to derive the distance of the object, in this case about 5500 light-years.

"This is a new and promising technique for providing distances of close novae. This was made possible because the state of the art facility of the VLTI, both in terms of infrastructure and management of the observations, allows one to schedule such observations," says co-author Markus Wittkowski from ESO.

Moreover, the quality of the data provided by the VLTI was such that it was possible to estimate the daily production of dust and infer the total mass ejected. "Overall, V1280 Sco probably ejected more than the equivalent of 33 times the mass of the Earth, a rather impressive feat if one considers that this mass was ejected from a star not larger in radius than the Earth," concludes Chesneau. Of this material, about a percent or less was in the form of dust.

In Beijing, Cash is Still King

Wed, 30 Jul 2008 10:02:54 GMT

In Beijing, Cash is Still King

Posted by Donald Morrison in Beijing, Practical, Shopping

If you look at Beijing’s soaring skyscrapers, gleaming motorways and glitzy shopping malls, it’s easy to conclude that this city is as modern as any in the world. And then the waiter brings the check. Sorry, madam, we don’t take credit cards.

In Beijing, more than any other big-country capital, cash is king. Official figures indicate that 110,000 Beijing businesses now accept credit cards, twice as many as in 2006. What those figures don’t show is how many accept only Chinese-issued cards (my guess is about half). And though 110,000 sounds like a large number, there are vastly more establishments that are extremely allergic to plastic of any color.

So when visiting Beijing, or some other Chinese city, it’s important to know how to get your hands on large amounts of cash. With an eye to the Olympics, Premier Wen Jiabao in 2006 ordered nine ministries and the central bank to “further develop consumer financial instruments.” The result was a vast expansion of retail banking – for decades virtually non-existent – including services for visitors. Though foreign credit cards may not yet be widely welcomed, foreign currency exchanges have proliferated, and it’s now possible to change cash and travelers checks at 80 percent of the city’s three-star-and-above hotels. Better yet, automated teller machines in Beijing are up to 9,400 and counting.

The trick is to find one that works. About half of all ATMs in China accept only credit and debit cards that are part of the domestic UnionPay system. So look for cash machines bearing the stickers of international networks like Visa, Plus, MasterCard and Cirrus. Then pray.

ATMs at Chinese banks get a workout – locals prefer them over the notoriously long lines at teller windows – so the machines are often out of cash or receipts or gas or spare parts. They also sometimes fail to make the connection to a foreigner’s bank. So if you get a message to contact your card issuer because your plastic has been declined, don’t despair. Just try another machine. And even when you find an ATM that works, withdrawals are typically limited to 2,000 yuan (about $280 at the current exchange rate) and sometimes less. Foreign banks like Citibank and HSBC have machines that dispense more. These are not numerous, but you will find a handful at the airport – both before and after customs.

Get as much cash as you can at one time, since you’ll be paying your bank’s $3 or $4 service fee no matter what amount you withdraw. Also, you’ll need those banknotes. Expect to pay for much of your food, transportation, tips, souvenirs, cheap sportswear at the Silk Market and, in some cases, even lodging in cash. Stacks of it. The largest bill is 100 yuan, worth only about $14 (it’s the red one, with Mao’s face on it). The government has put 36.5 billion new notes into circulation so far this year, twice as many as last year, so there is a good chance your stash of cash will be crisp and clean. Don’t be insulted if a cashier holds your bill up to the light to check its authenticity. Don’t be surprised if, upon handing over several bills, they are run through a counting machine, which nearly every Chinese business seems to have on hand. Or, more often, to be told that the credit card machine isn’t working right now, so how about paying in cash?

You can protest, stand on your rights as a credit-worthy customer of Visa, MasterCard or American Express, and ask to see the manager. That sometimes miraculously fixes the broken machine. But I always end up feeling like an idiot when I do the ugly American act. The alternative is to behave as the Chinese do: hand over a brick of bills and watch them be counted with the care found only in a country that loves its lucre, clean or filthy.

Diamonds May Have Been Life's Best Friend On Primordial Earth

Wed, 30 Jul 2008 10:01:04 GMT

Diamonds May Have Been Life's Best Friend On Primordial Earth

ScienceDaily (July 30, 2008) — Diamonds may have been life's best friend. Billions of years ago, the surface of these gems may have provided just the right conditions to foster the chemical reactions believed to have given rise to life on Earth, researchers in Germany report.

Their study is scheduled for the August 6 issue of ACS' Crystal Growth & Design, a bi-monthly journal.

In the new study, Andrei Sommer, Dan Zhu, and Hans-Joerg Fecht point out that scientists have theorized for years that the chemical precursors of life gradually evolved from a so-called "primordial soup" of simpler molecules. But the details of how these simpler amino acids molecules, the building blocks of life, were assembled into complex polymers, remains one of science's long-standing mysteries.

To find out, the research team studied diamonds, crystallized forms of carbon which are older than the earliest forms of life on Earth. In a series of laboratory experiments, the scientists showed that after treatment with hydrogen, natural diamond forms crystalline layers of water on its surface, essential for the development of life, and involved in electrical conductivity. When primitive molecules landed on the surface of these hydrogenated diamonds in the atmosphere of early Earth, the resulting reaction may have been sufficient enough to generate more complex organic molecules that eventually gave rise to life, researchers say.

Scientists are reporting that diamonds could have created chemical reactions billions of years ago that were believed to have caused life on Earth. (Credit: Wikimedia Commons)

Climate Change: Secret Life Cycles Of Atmospheric Aerosols Can Be Illuminated With New Technology

Wed, 30 Jul 2008 09:59:35 GMT

Climate Change: Secret Life Cycles Of Atmospheric Aerosols Can Be Illuminated With New Technology

ScienceDaily (July 29, 2008) — An aerosol mass spectrometer developed by chemists from Aerodyne Research Inc. and Boston College is giving scientists who study airborne particles the technology they need to examine the life cycles of atmospheric aerosols – such as soot – and their impact on issues ranging from climate change to public health.

Timothy B. Onasch, principal scientist for Aerodyne Research, Inc. (Billerica, Mass.) and Boston College chemistry professor Paul Davidovits check an apparatus they designed to produce uniform soot particles used for aerosols research. (Credit: Lee Pellegrini/Boston College)

BC Chemistry Professor Paul Davidovits and Aerodyne Principal Scientist Timothy B. Onasch say their novel spectrometer allows researchers to better understand what happens to these sub-microscopic particles that can absorb and scatter light and influence the lifetime of clouds.

"For scientists looking at climate change, the biggest uncertainty has to do with the effect of aerosol particles in the air," says Davidovits. "The issue is made that much more complex because aerosols can have different effects on climate. That means the target is constantly shifting."

The historic role of carbon-laden soot in climate change has been identified by researchers, particularly through ice samples taken from glaciers. Now scientists are focusing on tiny airborne particles of black carbon released into the atmosphere today in order to better understand the lifecycle of these aerosols in the atmosphere.

To that end, nearly 20 researchers from across the country brought other devices to the Davidovits lab this month to test and fine-tune these new tools developed by scientists from universities, industry and national laboratories at the forefront of this path-breaking science of the sky.

Hosted by Davidovits and Onasch, also an associate research professor at BC, the visiting researchers ran streams of laboratory-generated soot through devices able to analyze minute aerosol particles by mass, shape, chemical make-up, even the sound they make when warmed by light – a "pop" inaudible to the human ear.

"This is the cutting edge," says Dan Lack, a research scientist with the National Oceanic and Atmospheric Administration's Earth System Research Laboratory in Boulder, Colo. "Much of the technology in this room didn't exist until a few years ago. And there isn't another place in the country where you have all this technology running together in concert. It's a rare opportunity."

Among the 18 devices involved in the project are Billerica, MA-based Aerodyne's Aerosol Mass Spectrometer, Boulder-based Droplet Technologies' Single Particle Soot Photometer, and the NOAA-developed Cavity Ring-Down Aerosol Extinction and Photoacoustic Spectrometers, which shoot a laser beam into black carbon, causing the particle to "pop", emitting a frequency that's measured to gauge how much light carbon absorbs.

A technological focal point is a unique soot-particle generating apparatus operated by doctoral student Eben Cross, undergraduate Adam Ahern '09 and recent graduate Billy Wrobel '08. The design, construction, and operation of the device were funded by the atmospheric chemistry programs of the Department of Energy and the National Science Foundation.

In the race to determine the scope and speed of climate change and the influence of human activities on it, huge scientific efforts have focused on carbon dioxide gasses emitted largely from the burning of fossil fuels. Scientists believe particulates like black carbon may also contribute significantly to global warming.

For more than 15 years, Davidovits and his Aerodyne colleagues have pioneered the study of soot particles and gas-particle interactions, strengthening an understanding of the role of cloud and aerosol chemistry in acid rain, ozone depletion and climate change.

Aerosols raise temperatures, such as when black particles of soot rise in the sky, absorb sunlight and turn it into heat. Aerosols also can cool by reflecting light away from the earth. Clouds overstuffed with aerosols can inhibit rainfall.

While soot emitted from sources like diesel engines and electric power plants is a focus of study, not all aerosols are man-made. The deserts and arid landscapes of the world produce an estimated 10 to 20 billion tons of mineral aerosols a year. The air is full of biological aerosols as well – microbes, cells, and particles containing organic compounds.

Aerosols are somewhat fleeting. Unlike carbon dioxide, which can remain in the atmosphere for years, aerosols have an atmospheric life of about 10 to 20 days. In that time, they can absorb other molecules that alter their original state.

Measuring the many forms of atmospheric aerosols has led researchers to invent new devices, known as research-grade aerosol particle characterizing instruments, says Davidovits. The challenge now is to fine-tune those instruments in concert with each other in order to set reliable scientific benchmarks for future study.

Linked closely to the atmospheric effects of aerosols is a range of public health concerns, says Onasch.

"There is a need on many fronts – from the climate to public health – for greater understanding of the role aerosol particles play in our lives and what's happening here is the scientific community rising to meet those needs," says Onasch.

Did Dinosaur Soft Tissues Still Survive? New Research Challenges Notion

Wed, 30 Jul 2008 09:56:39 GMT

Did Dinosaur Soft Tissues Still Survive? New Research Challenges Notion

ScienceDaily (July 30, 2008) — Paleontologists in 2005 hailed research that apparently showed that soft, pliable tissues had been recovered from dissolved dinosaur bones, a major finding that would substantially widen the known range of preserved biomolecules.

Arrows on this electron microscope image indicate biofilms, or slime, peeling away from the walls of vascular canals in dinosaur bone. (Credit: Thomas Kaye)

But new research challenges that finding and suggests that the supposed recovered dinosaur tissue is in reality biofilm – or slime.

"I believed that preserved soft tissues had been found, but I had to change my opinion," said Thomas Kaye, an associate researcher at the Burke Museum of Natural History and Culture at the University of Washington. "You have to go where the science leads, and the science leads me to believe that this is bacterial biofilm."

The original research, published in Science magazine, claimed the discovery of blood vessels and what appeared to be entire cells inside fossil bone of a Tyrannosaurus rex. The scientists had dissolved the bone in acid, leaving behind the blood vessel- and cell-like structures.

But in a paper published July 30 in PloS ONE, a journal of the open-access Public Library of Science, Kaye and his co-authors contend that what was really inside the T. rex bone was slimy biofilm created by bacteria that coated the voids once occupied by blood vessels and cells.

He likens the phenomenon to what would happen if you left a pail of rainwater sitting in your backyard. After a couple of weeks you would be able to feel the slime that had formed on the inner walls of the bucket.

"If you could dissolve the bucket away, you'd find soft, squishy material in the shape of the bucket, and that's the slime," Kaye said. "The same is true for dinosaur bones. If you dissolve away the bone, what's left is biofilm in the shape of vascular canals."

Co-authors of the new paper are Gary Gaugler of Microtechnics Inc. of Granite Bay, Calif., and Zbigniew Sawlowicz of Jagiellonian University in Poland.

Kaye said he began his research with the hope of being the second person to find preserved dinosaur tissues. In addition to the acid bath procedure used in the previous work, he added examination by electron microscope before the bones were dissolved. He was surprised by the findings.

The researchers found that what previously had been identified as remnants of blood cells, because of the presence of iron, were actually structures called framboids, microscopic mineral spheres bearing iron. They found similar spheres in a variety of other fossils from various time periods, including an extinct sea creature called an ammonite. In the ammonite they found the spheres in a place where the iron they contain could not have had any relationship to the presence of blood.

"We determined that these structures were too common to be exceptionally preserved tissue. We realized it couldn't be a one-time exceptional preservation," Kaye said.

The scientists also dissolved bone in acid, as had been done previously, and found the same soft tissue structures. They conducted a comparison using infrared mass spectroscopy and determined the structures were more closely related to modern biofilm than modern collagen, extracellular proteins associated with bone. Carbon dating placed the origin at around 1960.

Using an electron microscope, the researchers saw coatings on the vascular canal walls that contained gas bubbles, which they associated with the presence of methane-producing bacteria. In addition, they examined what looked like tiny cracks within the vascular canals and found that they were actually small troughs, or channels. Study at high magnification revealed the channels had rounded bottoms and bridged each other, indicating they were organically created, likely by bacteria moving in a very thick solution.

"From this evidence, we could determine that what had previously been reported as dinosaurian soft tissues were in fact biofilms, or slime," Kaye said.

Why Are People Taller Today Than Yesterday?

Tue, 29 Jul 2008 08:13:51 GMT

Why Are People Taller Today Than Yesterday?

By LAURA BLUE

Download | Subscribe at iTunes

Yao Ming

Ryan Remiorz / AP

Skeletons and written records show that human beings today are inches taller than humans just a century or two ago. And yet even today average heights vary among different nationalities, even among genetically homogenous populations, like the South Koreans and North Koreans. (South Koreans are taller.) John Komlos, professor of economics at the University of Munich and a pioneer in studying human well-being through history, explains what governs human height, and why some populations are taller than others.

Q: Why are people taller today than yesterday?

A: There are two main reasons. One is that the diet has improved considerably. In spite of some very negative aspects of the diet of industrialized populations, we have much better vitamin, mineral and protein intake than 100 or 200 years ago. As a consequence the body can grow much better.

In addition, our health has improved considerably along with medical technology. We have fewer endemic diseases, and fewer epidemic diseases. That is important because an incidence of disease usually means that the nutrients we do consume are not absorbed by the body sufficiently. Diseases lay a claim on our energy intake, so that there is not enough left over for the body to grow. These two factors play a considerable role.

We have been increasing in height for about 140 years. Prior to that, there were cycles in height, depending on economic circumstances and agricultural productivity and so forth. We were relatively tall in the Middle Ages, when population densities were relatively low and food supplies were still fairly adequate. The low point was in the 17th century. Frenchmen, for example, were about 162 cm on average [not quite 5 ft. 4 in.], which is extremely small. Only since about the middle of the 19th century has there been a general trend upwards.

The American population was the tallest in the world from about the American Revolution to World War II — that's a long time. (There is a genetic component to [population] height, but there is very little genetic difference between European populations or their overseas offshoots.) America had a very resource-rich environment, with game, fish and wildlife. In fact we have data on disadvantaged people in America, such as slaves. They were obviously among the most mistreated populations in the world, but given the resource abundance — and given the fact that the slave owners needed their work — they had to be fed relatively decently. So slaves were taller than European peasants. It's no wonder that Europeans were just flooding to America.

[Americans today are no longer the tallest people in the world.] After the Second World War, many Western and Northern European countries began to adopt certain favorable social policies. There is universal health insurance in most of these societies — that, of course, makes a difference in health care. You can also consider income inequality in America, since people who are at the low end of the totem pole have considerable adversity making ends meet. I suspect the difference [in height between Americans and Europeans] is due to both diet and health care.

Americans today suffer from an additional problem: obesity. If children are too well nourished, then they're not able to grow optimally. There are certain hormones that control the onset of the adolescent growth spurt and the onset of adolescence. Nutrition is one of the factors, along with genetic and hormonal ones, that are associated with the onset of puberty. Overnutrition prior to adolescence may affect the hormonal system and may produce too much growth hormone prior to puberty, so that sex steroids are produced earlier. And if that comes too early, then the youth will peak out sooner, and will not become as tall in adulthood as someone who had better nutrition. Also, the overload of carbohydrates and fats in a fast-food diet may hinder the consumption of micronutrients essential to growth.

Cancer Center: Cell Phone Risk

Tue, 29 Jul 2008 08:12:11 GMT

Cancer Center: Cell Phone Risk

Thursday, Jul. 24, 2008 By AP/JENNIFER C. YATES AND SETH BORENSTEIN

A doctor makes a call on his cell phone.

JLP / Jose Luis Pelaez / zefa / Corbis

(PITTSBURGH) — The head of a prominent cancer research institute issued an unprecedented warning to his faculty and staff Wednesday: Limit cell phone use because of the possible risk of cancer.

The warning from Dr. Ronald B. Herberman, director of the University of Pittsburgh Cancer Institute, is contrary to numerous studies that don't find a link between cancer and cell phone use, and a public lack of worry by the U.S. Food and Drug Administration.

Herberman is basing his alarm on early unpublished data. He says it takes too long to get answers from science and he believes people should take action now — especially when it comes to children.

"Really at the heart of my concern is that we shouldn't wait for a definitive study to come out, but err on the side of being safe rather than sorry later," Herberman said.

No other major academic cancer research institutions have sounded such an alarm about cell phone use. But Herberman's advice is sure to raise concern among many cell phone users and especially parents.

In the memo he sent to about 3,000 faculty and staff Wednesday, he says children should use cell phones only for emergencies because their brains are still developing.

Adults should keep the phone away from the head and use the speakerphone or a wireless headset, he says. He even warns against using cell phones in public places like a bus because it exposes others to the phone's electromagnetic fields.

The issue that concerns some scientists — though nowhere near a consensus — is electromagnetic radiation, especially its possible effects on children. It is not a major topic in conferences of brain specialists.

A 2008 University of Utah analysis looked at nine studies — including some Herberman cites — with thousands of brain tumor patients and concludes "we found no overall increased risk of brain tumors among cellular phone users. The potential elevated risk of brain tumors after long-term cellular phone use awaits confirmation by future studies."

Studies last year in France and Norway concluded the same thing.

"If there is a risk from these products — and at this point we do not know that there is — it is probably very small," the Food and Drug Administration says on an agency Web site.

Still, Herberman cites a "growing body of literature linking long-term cell phone use to possible adverse health effects including cancer."

"Although the evidence is still controversial, I am convinced that there are sufficient data to warrant issuing an advisory to share some precautionary advice on cell phone use," he wrote in his memo.

A driving force behind the memo was Devra Lee Davis, the director of the university's center for environmental oncology.

"The question is do you want to play Russian roulette with your brain," she said in an interview from her cell phone while using the hands-free speaker phone as recommended. "I don't know that cell phones are dangerous. But I don't know that they are safe."

Of concern are the still unknown effects of more than a decade of cell phone use, with some studies raising alarms, said Davis, a former health adviser in the Clinton Administration.

She said 20 different groups have endorsed the advice the Pittsburgh cancer institute gave, and authorities in England, France and India have cautioned children's use of cell phones.

Herberman and Davis point to a massive ongoing research project known as Interphone, involving scientists in 13 nations, mostly in Europe. Results already published in peer-reviewed journals from this project aren't so alarming, but Herberman is citing work not yet published.

The published research focuses on more than 5,000 cases of brain tumors. The National Research Council in the U.S., which isn't participating in the Interphone project, reported in January that the brain tumor research had "selection bias." That means it relied on people with cancer to remember how often they used cell phones. It is not considered the most accurate research approach.

The largest published study, which appeared in the Journal of the National Cancer Institute in 2006, tracked 420,000 Danish cell phone users, including thousands that had used the phones for more than 10 years. It found no increased risk of cancer among those using cell phones.

A French study based on Interphone research and published in 2007 concluded that regular cell phone users had "no significant increased risk" for three major types of nervous system tumors. It did note, however, that there was "the possibility of an increased risk among the heaviest users" for one type of brain tumor, but that needs to be verified in future research.

Earlier research also has found no connection.

Joshua E. Muscat of Penn State University, who has studied cancer and cell phones in other research projects partly funded by the cell phone industry, said there are at least a dozen studies that have found no cancer-cell phone link. He said a Swedish study cited by Herberman as support for his warning was biased and flawed.

"We certainly don't know of any mechanism by which radiofrequency exposure would cause a cancerous effect in cells. We just don't know this might possibly occur," Muscat said.

Cell phones emit radiofrequency energy, a type of radiation that is a form of electromagnetic radiation, according to the National Cancer Institute. Though studies are being done to see if there is a link between it and tumors of the brain and central nervous system, there is no definitive link between the two, the institute says on its Web site.

"By all means, if a person feels compelled that they should take precautions in reducing the amount of electromagnetic radio waves through their bodies, by all means they should do so," said Dan Catena, a spokesman for the American Cancer Society. "But at the same time, we have to remember there's no conclusive evidence that links cell phones to cancer, whether it's brain tumors or other forms of cancer."

Joe Farren, a spokesman for the CTIA-The Wireless Association, a trade group for the wireless industry, said the group believes there is a risk of misinforming the public if science isn't used as the ultimate guide on the issue.

"When you look at the overwhelming majority of studies that have been peer reviewed and published in scientific journals around the world, you'll find no relationship between wireless usage and adverse health affects," Farren said.

Frank Barnes, who chaired the January report from the National Research Council, said Wednesday that "the jury is out" on how hazardous long-term cell phone use might be.

Speaking from his cell phone, the professor of electrical and computer engineering at the University of Colorado at Boulder said he takes no special precautions in his own phone use. And he offered no specific advice to people worried about the matter.

It's up to each individual to decide what if anything to do. If people use a cell phone instead of having a land line, "that may very well be reasonable for them," he said.

Susan Juffe, a 58-year-old Pittsburgh special education teacher, heard about Herberman's cell phone advice on the radio earlier in the day.

"Now, I'm worried. It's scary," she said.

She says she'll think twice about allowing her 10-year-old daughter Jayne to use the cell phone.

"I don't want to get it (brain cancer) and I certainly don't want you to get it," she explained to her daughter.

Sara Loughran, a 24-year-old doctoral student at the University of Pittsburgh, sat in a bus stop Wednesday chatting on her cell phone with her mother. She also had heard the news earlier in the day, but was not as concerned.

"I think if they gave me specific numbers and specific information and it was scary enough, I would be concerned," Loughran said, planning to call her mother again in a matter of minutes. "Without specific numbers, it's too vague to get me worked up."

———

Jennifer Yates reported from Pittsburgh. Science Writer Seth Borenstein reported from Washington. Reporter Ramit Plushnick-Masti contributed from Pittsburgh and Science Writer Malcolm Ritter contributed from New York.

How Bad Are iPods for Your Hearing?

Tue, 29 Jul 2008 08:05:07 GMT

How Bad Are iPods for Your Hearing?

Monday, Jul. 28, 2008 By LAURA BLUE

Download | Subscribe at iTunes

Man listening to iPod headphones

Ian Waldie / Getty

Hearing loss is more common than ever before. About 16% of American adults have an impaired ability to hear speech, and more than 30% of Americans over age 20 — an estimated 55 million people — have lost some high-frequency hearing, according to a new study published Monday in the Archives of Internal Medicine. The finding has got experts — and concerned parents — wondering anew: Does listening to loud music through headphones lead to long-term hearing loss? Brian Fligor, director of diagnostic audiology at Children's Hospital Boston, explains how much damage your headphone habit might cause — and how to mitigate your risk.

Q: How much hearing loss does an iPod cause?

A: It depends on the person, it depends on how long you're listening, and it depends on the level at which you're setting your iPod.

If you're using the earbuds that come with an iPod and you turn the volume up to about 90% of maximum and you listen a total of two hours a day, five days a week, our best estimates are that the people who have more sensitive ears will develop a rather significant degree of hearing loss — on the order of 40 decibels (dB). That means the quietest sounds audible are 40 dB loud. Now, this is high-pitched hearing loss, so a person can still hear sounds and understand most speech. The impact is going to be most clearly noted when the background-noise level goes up, when you have to focus on what someone is saying. Then it can really start to impair your ability to communicate.

This would happen only after about 10 years or so or even more of listening to a personal audio device. One patient I had used his headphones instead of earplugs when he was on his construction job. He thought as long as he could hear his music over the sound of his saws, he was protecting his ears — because he liked the sound of his music but didn't like the sound of the construction noise. He had a good 50 dB to 55 dB of noise-induced hearing loss at 28 years old. We asked a few pointed questions about when he was having difficulty understanding people, and his response was classic. "When I'm sitting at home with the TV off, I can understand just fine," he said, "but when I go out for dinner, I have trouble."

There is huge variation in how people are affected by loud sound, however, and this is an area where a number of researchers are conducting studies. Certainly a huge part of this is underlying genetics. We know how much sound causes how much hearing loss based on studies that were conducted in the late '60s and early '70s, before employers were required to protect workers' hearing in noisy work environments. What was found is that when people are exposed to a certain level of noise every day for a certain duration, they're going to have a certain degree of hearing loss on average. But the amount of hearing loss might differ by as much as 30 dB between people who had the toughest ears and those with the most tender ones — a huge variation. Unfortunately, we don't know who has the tougher ears and who has the tender ones until after they've lost their hearing. So, as a clinician, I have to treat everyone as if they had tender ears.

Particularly with noise-induced hearing loss, the primary area where the ear is damaged is not the eardrum, not the part of the ear that you can see and not the bones that are inside the middle ear — it is actually deeper inside. It's where the nerve that brings the sound message up to the brain connects with the inner ear, and it involves some very specialized cells. These are hair cells, and specifically we're looking at the outer hair cells. When they're overexposed or stimulated at too high a level for too long a duration, they end up being metabolically exhausted. They are overworked. They temporarily lose their function, so sound has to be made louder in order for you to hear it. These cells can recover after a single exposure, but if you overexpose them often enough, they end up dying, and you lose that functional ability inside your inner ear. The cells that die are not replaceable.

As far as a rule of thumb goes, the figures we got in our studies were that people using that standard earbud could listen at about 80% of maximum volume for 90 minutes per day or less without increasing their risk for noise-induced hearing loss. But the louder the volume, the shorter your duration should be. At maximum volume, you should listen for only about 5 minutes a day.

I don't want to single out iPods. Any personal listening device out there has the potential to be used in a way that will cause hearing loss. We've conducted studies of a few MP3 players and found very similar results across the MP3 manufacturers. Some in-the-ear earphones are capable of providing higher sound levels than some over-the-ear earphones. That said, studies we've done on behavior show that the type of earphones has almost nothing to do with the level at which people set their headphones. It's all dictated by the level of background noise in their listening environment. When we put people in different listening environments, like flying in an airplane — we used noise we'd recorded while flying on a Boeing 757 commercial flight, and we simulated that environment in our lab — 80% of people listened at levels that would eventually put their hearing at risk. On the subway system here in Boston, the ambient noise levels are very comparable to the level on an airplane, although it sounds very different. The noise is sufficiently high that it induces people to listen to their headphones at excessively loud volume.

I'm a self-professed loud-music listener. I use my iPod at the gym, and I love it. I think it's one of the greatest inventions ever. I even advocate that people listen to music as loud as they want. But in order to listen as loud as you want, you need to be careful about how long you're listening. I would also strongly recommend that people invest in better earphones that block out background noise. Some of the research we did studied earphones that completely seal up the ear canal. These are passive sound-isolating earphones, as opposed to the ones that are active noise cancelers that block out some of the noise. As far as I can tell, both would allow people to listen to their headphones at their chosen level — and more likely at a lower volume than if they were using the stock earbuds.

Study Suggests 86 Percent Of Americans Could Be Overweight Or Obese By 2030

Tue, 29 Jul 2008 07:58:50 GMT

Study Suggests 86 Percent Of Americans Could Be Overweight Or Obese By 2030

ScienceDaily (July 29, 2008) — Most adults in the U.S. will be overweight or obese by 2030, with related health care spending projected to be as much as $956.9 billion, according to researchers at the Johns Hopkins Bloomberg School of Public Health, the Agency for Healthcare Research and Quality and the University of Pennsylvania School of Medicine. Their results are published in the July 2008 online issue of Obesity.

A new study projects that most adults in the U.S. will be overweight or obese by 2030. (Credit: iStockphoto/Christopher Pattberg)

“National survey data show that the prevalence of overweight and obese adults in the U.S. has increased steadily over the past three decades,” said Youfa Wang, MD, PhD, lead author of the study and associate professor with the Bloomberg School’s Center for Human Nutrition. “If these trends continue, more than 86 percent of adults will be overweight or obese by 2030 with approximately 96 percent of non-Hispanic black women and 91 percent of Mexican-American men affected. This would result in 1 of every 6 health care dollars spent in total direct health care costs paying for overweight and obesity-related costs.”

The researchers conducted projection analyses based on data collected over the past three decades from nationally representative surveys. Their projections illustrate the potential burden of the U.S. obesity epidemic if current trends continue.

“Our analysis also shows that over time heavy Americans become heavier,” says May A. Beydoun, a former postdoctoral research fellow at the Johns Hopkins Bloomberg School of Public Health.

“The health care costs attributable to obesity and overweight are expected to more than double every decade. This would account for 15 to 17 percent of total health care costs spent,” Wang says. “Due to the assumptions we made and the limitations of the available data, these figures are likely an underestimation of the true financial impact.”

Current standards define adults with a body mass index (BMI) between 25 and 29.9 as overweight and adults with a BMI of 30 or higher as obese. Both the overweight and obese are at an increased risk for developing a number of health conditions, including hypertension, type 2 diabetes, heart disease and stroke. Researchers estimate that children and young adults may have a shorter life expectancy than their parents if the obesity epidemic is left unaddressed.

The authors warned that obesity has become a public health crisis in the U.S. Timely, dramatic and effective development and implementation of corrective programs and policies are needed to avoid the otherwise inevitable health and societal consequences implied by their projections. If current trends continue, the researchers say that the U.S. Department of Health and Human Services will not meet its Healthy People 2010 initiative to increase the proportion of adults who are at a healthy weight and to reduce the proportion of adults who are obese.

Climate Experts Tussle Over Details. Public Gets Whiplash.

Tue, 29 Jul 2008 07:49:29 GMT

Climate Experts Tussle Over Details. Public Gets Whiplash.

Michael Kappeler/Agence France-Presse — Getty Images; Erik S. Lesser for NYT; NOAA; NASA

DATA DELUGE From left, Greenland ice, lemur leaf frog, hurricanes tracks and a plot of buoys used in sea temperature studies. Discordant findings aside, the theory of rising human influence on climate endures.

By ANDREW C. REVKIN

Published: July 29, 2008

When science is testing new ideas, the result is often a two-papers-forward-one-paper-back intellectual tussle among competing research teams.

When the work touches on issues that worry the public, affect the economy or polarize politics, the news media and advocates of all stripes dive in. Under nonstop scrutiny, conflicting findings can make news coverage veer from one extreme to another, resulting in a kind of journalistic whiplash for the public.

This has been true for decades in health coverage. But lately the phenomenon has been glaringly apparent on the global warming beat.

Discordant findings have come in quick succession. How fast is Greenland shedding ice? Did human-caused warming wipe out frogs in the American tropics? Has warming strengthened hurricanes? Have the oceans stopped warming? These questions endure even as the basic theory of a rising human influence on climate has steadily solidified: accumulating greenhouse gases will warm the world, erode ice sheets, raise seas and have big impacts on biology and human affairs.

Scientists see persistent disputes as the normal stuttering journey toward improved understanding of how the world works. But many fear that the herky-jerky trajectory is distracting the public from the undisputed basics and blocking change. “One of the things that troubles me most is that the rapid-fire publication of unsettled results in highly visible venues creates the impression that the scientific community has no idea what’s going on,” said W. Tad Pfeffer, an expert on Greenland’s ice sheets at the University of Colorado.

“Each new paper negates or repudiates something emphatically asserted in a previous paper,” Dr. Pfeffer said. “The public is obviously picking up on this not as an evolution of objective scientific understanding but as a proliferation of contradictory opinions.”

Several experts on the media and risk said that one result could be public disengagement with the climate issue just as experts are saying ever more forcefully that sustained attention and action are needed to limit the worst risks. Recent polls in the United States and Britain show that the public remains substantially divided and confused over what is happening and what to do. Some environmentalists have blamed energy-dependent industries and the news media for stalemates on climate policy, arguing that they perpetuate a false sense of uncertainty about the basic problem.

But scientists themselves sometimes fail to carefully discriminate between what is well understood and what remains uncertain, said Kimberly Thompson, an associate professor of risk analysis and decision science at Harvard.

And, Dr. Thompson said, the flow of scientific findings from laboratory (or glacier) to journal to news report is fraught with “reinforcing loops” that can amplify small distortions.

For example, she said, after scientists learn that accurate, but nuanced, statements are often left out of news accounts, they may pre-emptively oversimplify their description of some complex finding. Better, but more difficult, Dr. Thompson said, would be to work with the reporter to characterize the weight of evidence behind the new advance and seek to place it in context.

To support clarity, Stephen H. Schneider, a climatologist at Stanford, helped create a glossary defining what is meant by phrases like “very likely” (greater than 90 percent confidence) in the reports from the Intergovernmental Panel on Climate Change. In a news media universe where specialized reporting is declining and a Web mash-up of instant opinion and information is emerging, Dr. Schneider said, it is ever more important for scientists to take responsibility for communicating in ways that stick, while sticking with the facts.

Dr. Thompson said climate science presented particularly tough challenges, given the long time lag before the worst effects kick in and the persistent uncertainty about the likelihood of worst-case outcomes. She said the news media sometimes overplayed the uncertainty by balancing opposing views in a story without characterizing the overall level of confidence in either side. And sometimes they do the opposite, sacrificing accuracy for impact, she said.

“Words that we as scientists use to express uncertainty routinely get dropped out to make stories have more punch and be stronger,” she said, adding that those words are important to include because “they convey meaning to readers not only in the story at hand, but more generally about science being less precise than is typically conveyed.”

Public-relations offices at leading scientific journals and hubs for research also could do more to avoid overplaying incremental research results, she and several other experts said.

Donald Kennedy, a Stanford professor emeritus who was the editor in chief of the journal Science from 2000 until earlier this year, said the flow of papers on climate, glaciology and relevant ocean sciences greatly increased in his tenure. “I do think we grew more sensitive to the need for critical review of papers likely to initiate or continue the kind of controversy that results in a whiplash effect,” Dr. Kennedy said.

Roger A. Pielke Jr., a political scientist at the University of Colorado, warned that the focus by the public and media on the stream of evolving climate science could distract from the need for policies now that made sense regardless of uncertainties. “The example of reducing losses to hurricanes is a good one,” Dr. Pielke said, “where the actions that make the most sense are really independent of the debate over greenhouse gases and hurricane behavior.”

“The same might be said for many health studies on fat, coffee, carbs,” he added. “The lesson from experts is to eat a balanced diet and get plenty of exercise,” which stays the same despite the various disputes.

He said his advice for scientists who wanted to “dampen the whiplash effect” was to “discuss the ‘So what?’ implications of the work explicitly, rather than leaving that step to advocates or politicians, or reporters.”

Increasingly, scientists are taking their message straight to the public. Realclimate.org, Climatepolicy.org and Climateethics.org are among Web sites where issues are explored in an ongoing way, rather than in response to news releases and scientific papers. Other new Web ventures, like ClimateCentral.org at Princeton and the Yale Forum on Climate Change and the Media, focus on improving media coverage.

Robert J. Brulle , a sociologist at Drexel University, said it was hard to be optimistic about such efforts. “In this public sphere,” he said, “it is assumed that the better argument, backed up with solid scientific evidence, will prevail.” He said many studies had shown that people tended to sift sources of information to reinforce existing views.

Morris Ward, the editor of the Yale effort (yaleclimatemediaforum.org), says that it will be up to the public to choose to be better informed on momentous issues that do not fit the normal template for news or clash with their ingrained worldviews. “At some point,” he said, “the public at large has to step up to the plate in terms of scientific and policy literacy, in terms of commitment to education and strong and effective political leadership, and in terms of their own general self-improvement.”

Ring Around the Sun

Tue, 29 Jul 2008 07:46:29 GMT

Ring Around the Sun

By C. CLAIBORNE RAY

Published: July 29, 2008

Victoria Roberts

Q. What caused the weird sunset I observed from Cape Cod last month? A well-defined, orange-red, glowing ring surrounded the sun.

A. What you saw is a variation of the optical phenomena that can appear when light interacts with the air and the substances in the air, said Todd Miner, a meteorologist at Pennsylvania State University. “This falls under the category of halo,” he said.

More common phenomena include sundogs, two bright spots on either side of the sun, and sun pillars, which emanate upward or even downward from the disk of the sun. All are caused by the bending of light rays before they meet the observer’s eyes.

Like a halo around the moon, a circular structure around the sun would normally be generated mainly by small ice crystals in the atmosphere. Depending on the size, shape and orientation of the particles, the light may be refracted into all the colors of the rainbow or a single color, like red.

At sunset, the pathway of light through the atmospheric particles and the air molecules themselves is much longer than at midday, leading to a general filtering of the light so that the blue wavelengths become scattered, Mr. Miner said. This leaves mostly the red and orange you observed. Also, it is probable that the ice particles were really tiny, leading to the sharply defined edges of both the sun and the red ring around it that you observed.

Readers are invited to submit questions by mail to Question, Science Times, The New York Times, 620 Eighth Avenue, New York, N.Y. 10018-1405, or by e-mail to question@nytimes.com.

Exposure To Bad Air Raises Blood Pressure, Study Shows

Tue, 29 Jul 2008 07:42:01 GMT

Exposure To Bad Air Raises Blood Pressure, Study Shows

ScienceDaily (July 29, 2008) — The air people breathe while walking in the park, working in the garden or shopping downtown may be unhealthy enough to seriously spike their blood pressure, a new study suggests.

Cardiovascular researchers at The Ohio State University Medical Center are the first to report a direct link between air pollution and its impact on high blood pressure, or hypertension. If the results from these animal studies hold up, this could be important for human health.

“We now have even more compelling evidence of the strong relationship between air pollution and cardiovascular disease,” said Sanjay Rajagopalan, section director of vascular medicine at Ohio State’s Medical Center and co-author of the study. This builds upon previous research from Rajagopalan’s team published in the journals JAMA, Circulation and Inhalation Toxology.

Researchers exposed rats to levels of airborne pollutants that humans breathe everyday, noting the levels were still considerably below levels found in developing countries such as China and India, and in some parts of the U.S.

Researchers found that short-term exposure to air pollution, over a 10-week period, elevates blood pressure in those already predisposed to the condition. The results appear online and are scheduled for publication in an upcoming issue of Arteriosclerosis, Thrombosis, and Vascular Biology, a journal published by the American Heart Association.

“Recent observational studies in humans suggest that within hours to days following exposure, blood pressure increases,” Rajagopalan says.

In a highly-controlled experiment, hypertensive rats were placed in chambers and exposed to either particulate matter or filtered air for six hours a day, five days a week, over a period of 10 weeks. At week nine, researchers infused angiotensin II, another pollutant, into mini-pumps within the chambers and monitored responses in blood pressure over one week.

The air pollution level inside the chamber containing particulate matter was comparable to levels a commuter may be exposed to in urban areas with heavy traffic such as downtown Manhattan. “Pre-exposure to air pollution markedly increased blood pressure responses following infusion of angiotensin II,” added Rajagopalan.

According to the U.S. Environmental Protection Agency (EPA), the four most common pollutants emitted into the air are particulate matter, ozone, nitrogen dioxide and sulfur dioxide. Air pollution is commonly the result of industrial emissions, coal burning, power plants and automobile exhaust.

“This study provides guidance for the EPA to change pre-existing stringent standards in the effort to reduce air pollution,” says Rajagopalan. “Our study also confirmed a need for a broader based approach, from the entire world, to influence policy development.”

Qinghua Sun, first author of the study, will analyze vascular function in humans before and after the upcoming summer Olympics in Beijing, China. With stringent laws to ensure good quality during the games, it is anticipated that the air quality will improve significantly in and around Beijing. “We expect to find a tangible impact on vascular function and blood pressure because ultimately the only thing that will have changed is levels of air pollution,” says Sun.

Researchers at the University of Michigan, the U.S. Environmental Protection Agency, the Institute of Statistical Science and the New York University School of Medicine participated in the study.

Along with Rajagopalan and Sun, other Ohio State researchers involved in the study were Peibin Yue, Zhekang Ying and Arturo J. Cardounel. Funding from the National Institutes of Health supported this research.

According to the World Health Organization (WHO), more than three million premature deaths each year can be attributed to air pollution, with more than half of the population residing in developing low- and middle-income countries where air pollution levels are at their highest. For example, severe air pollution in Beijing, China, where the average concentration is well above five times that of levels typically found in the U.S., is the result of rapid industrial development, urbanization and increased traffic into the capital. WHO relies on scientific evidence and considers its implications when determining air quality guidelines.

Study Provides Clues To Preventing And Treating Cancer Spread

Tue, 29 Jul 2008 07:39:42 GMT

Study Provides Clues To Preventing And Treating Cancer Spread

ScienceDaily (July 29, 2008) — Isn't it odd that cancer cells from one organ, such as the skin, can travel and take root in a totally different organ, like the lung?

What's more, why is it that certain cancers prefer to spread, or metastasize, to certain places? Prostate cancer usually moves to bone; colon cancer, to the liver.

To answer these questions, Dr. Hendrik van Deventer, assistant professor of medicine at the University of North Carolina at Chapel Hill and a member of the UNC Lineberger Comprehensive Cancer Center, turned to a century-old idea of cancer spread: English surgeon Stephen Paget's "seed and soil."

The idea is that the spread of cancer isn't just about the tumor itself (the seed), but also the environment where it grows (the soil). Other scientists have shown that cells from bone marrow can migrate and change the environment so that it is receptive to incoming cancer cells. These cells do so by forming small neighborhoods or niches within distant organs. Thus, biologists refer to these areas as "premetastic niches."

Van Deventer and his colleagues wanted to know what mysterious non-tumor cell could change a normal organ so cancer cells would invade. If scientists could discover the identity of that normal cell, maybe they could devise treatments to stop metastases.

In a study published in the July issue of The American Journal of Pathology, van Deventer showed for the first time that that cell could be a fibrocyte – cells that travel around the body, rushing to the site of an injury to aid in healing when needed. The study also suggests ways to develop treatments to prevent metastases using already available medications.

"This study shows it's possible for fibrocytes to form the premetastatic niche. But it stops short of proving they positively are the cells," van Deventer said.

The UNC researcher's work with fibrocytes began when he wanted to figure out why "knockout mice" that are missing the cell receptor CCR5 get fewer cancer metastases than normal mice. CCR5 helps control the migration of cells through the body. He injected these knockout mice with all types of cells from normal mice, to try to make the mice form more metastases of melanoma (skin cancer).

The only cells that did it were those that appeared to be fibrocytes.

When van Deventer injected the mice with just 60,000 of these cells, the rate of metastases nearly doubled. "That's a big effect for a relatively small number of cells," he said.

Though cancer researchers don't usually study fibrocytes, it makes sense to van Deventer that fibrocytes could form the premetastatic niche. In healthy humans, fibrocytes travel through the bloodstream to areas of injury. Once there, they produce changes that are good for wounds. Unfortunately, these same changes can help cancers grow. It is not yet clear if fibrocytes are causing these problems in cancer patients. However, "there is some clinical data that suggests that these cells are increased in patients with metastatic cancer," he said.

The experiment also showed that injection of these cells induced MMP9, an enzyme that is known to promote cancer. The researchers considered this good news, since drugs are available that block MMP enzymes and have proven beneficial in treating cancer.

Still, many basic questions remain to be answered. How do cancers promote the formation of the premetastatic niche? Do they change the behavior of these circulating cells or simply increase their number? Are some patients at higher risk for metastasis because their environment changes their fibrocytes? Is some of the benefit of our cancer treatments lost because of inadvertent changes to these cells?

"These are daunting questions, but ones that would have pleased Dr. Paget," van Deventer said. "This paper gives us a place to start looking for the answers."

Other authors of the study, all from UNC Lineberger, are research specialist Qing Ping Wu; professional fellow Daniel T. Bergstralh, Ph.D.; research associate Beckley K. Davis, Ph.D.; postdoctoral fellow Brian P. O'Connor, Ph.D., distinguished professor of microbiology and immunology Jenny P. Y. Ting, Ph.D.; and distinguished associate professor of medicine and of microbiology and immunology, Jonathan S. Serody, M.D., Ph.D.

The study was funded by the National Cancer Institute, part of the National Institutes of Health.