Gaia: Universal Science Forum

Mammoths Were Alive More Recently Than Thought

http://seekeralpha.gaia.com — Wed, 16 Dec 2009 00:51:01 GMT

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By LiveScience Staff
posted: 15 December 2009 11:59 am ET
Woolly mammoths and other large beasts in North America may not have gone extinct as long ago as previously thought.
The new view — that pockets of beasts survived to as recently as 7,600 years ago, rather than the previous end times mark of 12,000 years ago — is supported by DNA evidence found in a few pinches of dirt.
After plucking ancient DNA from frozen soil in central Alaska, researchers uncovered "genetic fossils" of both mammoths and horses locked in permafrost samples dated to between 10,500 and 7,600 years ago.
"We don't know how long it takes to pinch out a species," said Ross MacPhee, Curator of Mammalogy at the American Museum of Natural History. "Extinctions often seem dramatic and sudden in fossil records, but our study provides an idea of what an extinction event might look like in real time, with imperiled species surviving in smaller and smaller numbers until eventually disappearing completely."
At the end of the Pleistocene, the geological epoch roughly spanning 2.5 million years ago to 12,000 years ago, many of the world's megafauna — giant sloths, saber-toothed cats, dire wolves, stag-moose, and mammoths — vanished from the geological record. Some large species such as Equus caballus, the species from which the domestic horse derives, became extinct in North America but persisted in small populations elsewhere.
Scientists have blamed the extinctions on everything from human overhunting to a comet impact to the introduction of novel infectious diseases.
The swiftness of the extinctions, however, is not suggested directly by the fossils themselves but is inferred from radiocarbon dating of bones and teeth discovered on the surface or buried in the ground, the researchers involved in the new study point out. Current "macrofossil" evidence places the last-known mammoths and wild horses between 15,000 and 13,000 years ago.
But hard remains of animals are rarely preserved, difficult to find, and laborious to accurately date because of physical degradation, the scientists said in a statement today.
So MacPhee and colleagues decided to tackle the problem by dating the creatures through dirt. Frozen sediments from the far north of Siberia and Canada can preserve small fragments of animal and plant DNA exceptionally well, even in the complete absence of any visible organic remains, such as bone or wood.
"In principle, you can take a pinch of dirt collected under favorable circumstances and uncover an amazing amount of forensic evidence regarding what species were on the landscape at the time," said co-researcher Eske Willerslev, director of the Centre for GeoGenetics at the University of Copenhagen.
The team collected soil cores from undisturbed Alaskan permafrost. Two independent methods (radiocarbon and optically stimulated luminescence) were used to date plant remains and individual mineral grains found in the same layers as the DNA.
"With these two techniques, we can be confident that the deposits from which the DNA was recovered haven't been contaminated since these lost giants last passed this way," said Richard Roberts of the University of Wollongong in Australia. "It's a genetic graveyard, frozen in time."
The core samples revealed the local Alaskan fauna at the end of the last Ice Age. The oldest sediments, dated to about 11,000 years ago, contain remnant DNA of Arctic hare, bison, and moose; all three animals were also found in higher, more recent layers, as would be expected. But one core, deposited between 10,500 and 7,600 years ago, confirmed the presence of both mammoth and horse DNA.
The team also developed a statistical model to show that mammoth and horse populations would have dwindled to a few hundred individuals by 8,000 years ago.
"At this point, mammoths and horses were barely holding on. We may actually be working with the DNA of some of the last members of these species in North America," said team member Duane Froese of the University of Alberta in Canada.
The findings are detailed in the Proceedings of the National Academy of Sciences.

Re: Climate change cover-up? You better believe it

http://seekeralpha.gaia.com — Tue, 15 Dec 2009 22:47:38 GMT

Sorry, inlink2009, but I checked that link and found it to have no relevance to the issue at hand. Furthermore, I have no belief or interest in astrology or the legends relating to the lost continent of Atlantis. They are unscientific and this is a group that deals ONLY with science.
You will be removed from this group.

Re: Climate change cover-up? You better believe it

http://inlink2009.gaia.com — Tue, 15 Dec 2009 14:38:28 GMT

Something is wrong in the above referenced address. Try this:

http://groups.gaia.com/50_stars/conversations/view/508954#510811

Re: Climate change cover-up? You better believe it

http://inlink2009.gaia.com — Tue, 15 Dec 2009 14:26:41 GMT

I received a Gaia email from Dale Husband this morning inviting me to the Universal Science Forum—to the conversation, “climate change coverup? You better believe it.” Dale’s conversation is confined to the space-time dimension. The cutting edge of science is exploring other dimensions. You can find a discussion of those other dimensions to consider at the Aquarius-Atlantis Connection.

Survival of Tibetan Glaciers

http://seekeralpha.gaia.com — Tue, 15 Dec 2009 08:05:51 GMT

http://www.giss.nasa.gov/research/briefs/hansen_14/
By James Hansen — December 2009Glaciers on the Tibetan Plateau, sometimes called Earth's "third pole", hold the largest ice mass outside the polar regions. These glaciers act as a water storage tower for South and East Asia, releasing melt water in warm months to the Indus, Ganges, Brahmaputra and other river systems, providing fresh water to more than a billion people. In the dry season glacial melt provides half or more of the water in many rivers.
Tibetan glaciers have been melting at an accelerating rate over the past decade. Glacier changes depend on local weather, especially snowfall, so glacier retreat or advance fluctuates with time and place. Thus it is inevitable that some Tibetan glaciers advance over short periods, as has been reported. But overall, Tibetan glaciers are retreating at an alarming rate.
Global warming must be the primary cause of glacier retreat, which is occurring on a global scale, but observed rapid melt rates suggest that other factors may be involved. To investigate the possible role of black soot in causing glacial melt, a team of scientists from Chinese research institutes extracted ice cores from five locations on the Tibetan Plateau (Figure 1).
Black soot, which includes black carbon (BC) and organic carbon (OC), absorbs sunlight and can speed glacial melting if BC reaches values of order 10 ng/g (nanograms per gram) or larger. The ice core data revealed that BC reached values of 20-50 ng/g in the 1950s and 1960s for the four stations that are downwind of European pollution sources. BC and OC amounts decreased strongly in the early 1970s, probably because of clean air regulations in Europe.
However, the ice cores also reveal that in the past decade BC and OC began to increase again, even on the Zuoqiupu glacier (Figure 2), which is mainly subject to Asian sources. The data suggest that increased black soot arises from Asian sources, especially the Indian subcontinent.
The measured concentrations of BC and OC refer to fresh snow. But as the snow melts in the spring and summer the black soot concentrations on the glacier surface increase, because the soot particles do not escape in the melt water as efficiently as the water itself. As a consequence, the soot noticeably darkens the glacier surface during the melt season, increases absorption of sunlight, and speeds glacier disintegration.
In a new paper by Xu et al., we concluded that black soot is contributing to the rapid melt of glaciers in the Himalayas. And continued, "business-as-usual" emissions of greenhouse gases and black soot will result in the loss of most Himalayan glaciers this century, with devastating effects on fresh water supplies in dry seasons.
But business-as-usual emissions are not inevitable. An alternative scenario, which stabilizes the glaciers and has other benefits for global climate and human health, requires a reduction of major human-made climate forcing agents that have a warming effect — that means greenhouses gases, especially carbon dioxide, as well as black soot.
Quantitative policy implications have been defined: coal emissions must be phased out over the next 20 years, and unconventional fossil fuels, such as tar sands and oil shale, must remain undeveloped. Combined with improved agricultural and forestry practices and reduction of methane and black soot emissions, these actions would avoid demise of the Tibetan glaciers.
Not coincidentally, these policy actions are the same as those required to stabilize Earth's energy balance and keep the climate near the Holocene climate range in which civilization developed. The question is whether the global community can exercise the free will to limit fossil fuel emissions and move to clean energies of the future — or is it inevitable that all fossil fuels will be burned?
The conclusion is that prospects for survival of Tibetan glaciers can be much improved by reducing black soot emissions. The black soot arises especially from diesel engines, coal use without effective scrubbers, and biomass burning, including cook stoves. Reduction of black soot via cleaner energies would have other benefits for human health and agricultural productivity. However, survival of the glaciers also requires halting global warming, which depends upon stabilizing and reducing greenhouse gases, especially carbon dioxide.
References
Xu, B, J. Cao, J. Hansen, T. Yao, D.J. Joswia, N. Wang, G. Wu, M. Wang, H. Zhao, W. Yang, X. Liu, and J. He, 2009: Black soot and the survival of Tibetan glaciers. Proc. Natl. Acad. Sci., doi: 10.1073/pnas.0910444106, in press.
Hansen, J., Mki. Sato, P. Kharecha, D. Beerling, R. Berner, V. Masson-Delmotte, M. Pagani, M. Raymo, D.L. Royer, and J.C. Zachos, 2008: Target atmospheric CO2: Where should humanity aim? Open Atmos. Sci. J., 2, 217-231, doi:10.2174/1874282300802010217.

20 Things You Didn't Know About... Sugar

http://seekeralpha.gaia.com — Mon, 14 Dec 2009 05:03:28 GMT

LINK
1 The average American eats 61 pounds of refined sugar each year, including 25 pounds of candy. Halloween accounts for at least two pounds of that.
2 Trick: Sugar may give you wrinkles via a process called glycation, in which excess blood sugar binds to collagen in the skin, making it less elastic.
3 Or treat: Cutting back on sugar may help your skin retain its flexibility. So actually, no treats.
4 People in India have been crystallizing cane sugar for at least 2,000 years. When Alexander the Great’s companions arrived there, they marveled at the production of honey without bees.
5 In 1747 German chemist Andreas Marggraf discovered that the sugar in a sugar beet is identical to that in sugarcane. In 1802 the first beet-sugar refinery began operations, bringing cheap sweets to northern climes.
6 More than half the 8.4 million metric tons of sugar produced annually in the United States comes from beets.
7 Can you imagine eating 16 sugar cubes at one sitting? You probably have. That’s a little less than what is contained in a 20-ounce bottle of cola.
8 Soft drinks with artificial sweeteners may actually help make you fat. In a Purdue University study, rats drinking liquids with artificial sweeteners consumed more calories overall than rats whose drinks were sweetened with sugar.
9 The artificial sweeteners saccharin and aspartame were found accidentally when lab workers doing research that had nothing to do with sweetening put a bit of the test compounds in their mouths and liked what they tasted.
10 What kind of researcher sticks an experiment in his mouth?
11 At least he had an excuse. The scientists who discovered sucralose (now sold as Splenda) were originally trying to create an insecticide. An assistant thought he had been instructed to “taste” a compound he’d only been asked to “test.”
12 A compound called lugduname is the sweetest compound known—more than 200,000 times as sweet as table sugar.
13 Sugars are molecules of carbon, hydrogen, and oxygen. The simplest include glucose, fructose, and galactose. Table sugar is crystallized sucrose, a fusion of one fructose and one glucose molecule.
14 Can’t escape them: Sugars are the building blocks of carbohydrates, the most abundant type of organic molecules in living things.
15 Glycolaldehyde, an eight-atom sugar, has even been found in an interstellar gas cloud near the center of the Milky Way.
16 Glycolaldehyde can react with a three-carbon sugar to form ribose, the basis for both RNA and DNA, so the glycolaldehyde found in deep space may be a chemical precursor to life on Earth.
17 That cloud also contains ethylene glycol, a sweet relative of glycolaldehyde and the main ingredient in antifreeze. Either complex sugars can be synthesized between the stars or there is a truck stop at the end of the universe.
18 Sugar can help get you there to find out. Burn sucrose with a dose of corn syrup and saltpeter and you get “sugar propellant,” a popular amateur rocket fuel.
19 How do you spell relief? “Obecalp,” a sugar pill manufactured to FDA standards, is marketed as a treatment for children’s mild complaints. (Try reading the name backward.)
20 It’s not all mind games. The sugar glucosamine works as an immunosuppressant in mice, and xylitol (a sugar alcohol) can prevent ear infections in kids. Sweet!

Re: List of 'unsung' wildlife affected by climate change released

http://Meenakshi.gaia.com — Mon, 14 Dec 2009 03:12:07 GMT

Thank you for this posting this report, Dale. I remember reading about the
The Tragedy of The Yangtze River Dolphin | SciencerayAug 20, 2009 ... The small, shy baiji is one of five species of freshwater river dolphin. In 2006, the Yangtze River dolphin became functionally extinct.

That though if I remember write in the magazine I'd picked up, was due to pollution and human commercial activity in the river.

Fruit flies can be alcoholics too

http://seekeralpha.gaia.com — Sat, 12 Dec 2009 16:19:06 GMT

LINK
Behavior of Drosophila shows similarities to human addiction
By Laura Sanders
Web edition : Thursday, December 10th, 2009
Guard the bourbon fruitcake: Fruit flies like a little booze in their food. And once they get a nip, they’re hooked, say scientists studying Drosophila melanogaster, the darling of genetic scientists around the world. The flies show evidence of alcohol addiction, including drinking despite dangerous consequences, a study appearing online December 10 in Current Biology reports.
Studying a model of alcoholism in a simple organism like the fruit fly may lead to a better understanding of the disease in humans. The new research is “a big step forward,” says Zachary Rodd, a behavioral pharmacologist who studies rodent models of alcoholism at Indiana University School of Medicine in Indianapolis. “It’s always good to have many models. Each model has its benefits and its limitations. Drosophila has a lot of positives behind it.”
Earlier studies found that alcohol has profound physiological effects on fruit flies, but the new study is one of the first to offer flies the choice to drink. Anita Devineni and Ulrike Heberlein, both of the University of California, San Francisco, devised a fly-sized drinking device reminiscent of the water bottles in hamster cages. Flies held inside vials could sip from thin tubes holding either liquid food spiked with 15 percent ethanol or plain liquid food. The researchers measured the descent of the liquids inside each tube to get a readout of which food the flies preferred.
Flies slurped down the booze-laden food much faster than the straight food, the researchers found. This alcohol preference became stronger over five days as the animals adjusted to the drinking. When Devineni and Heberlein varied the amount of alcohol in the food, they found that flies that had been drinking for only one to two days didn’t seem to like the strong stuff, but regular drinkers that had been consuming alcohol for four to five days did. These flies drank food that contained up to 25 percent alcohol.
As the flies drank alcohol, Devineni observed drunken behavior such as hyperactivity and loss of coordination. The researchers were unable to get exact measurements of alcohol levels in individual flies because they’re so small. “I think they are intoxicated, but it’s unclear to what degree,” Devineni says.
Fruit flies accustomed to alcohol continued to drink despite potential harm, the team found. When the researchers laced the booze-food mix with small amounts of the toxic chemical quinine, those flies continued to drink, even though fruit flies normally avoid the chemical. “I was actually pretty surprised when they continued to drink it,” Devineni says.
In another test, flies were allowed to drink freely for five days, then were deprived of alcohol for either one or three days. After the dry period, the flies immediately returned to peak levels of drinking, a hallmark of relapse.
This fruit fly model of alcoholism may provide researchers with new experimental options, such as the ability to easily track down genes that are involved with the disease. Some of these genes may be the same as those in humans. “It’s known that there’s a strong genetic component to alcoholism,” Devineni says. “Flies are one of the best model systems for genetics,” she adds.

Want fresh air? Give your house a nose job…

http://seekeralpha.gaia.com — Sat, 12 Dec 2009 02:43:56 GMT

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15:16 08 December 2009 by Paul Marks
Central heating may keep your house warm, but it can also make the air stuffy. A new ventilation system that works like the nose of a small desert rat might let your house "breathe", freshening the air while maintaining cosiness.So claims Steven Vogel of Duke University in Durham, North Carolina. Like some other desert creatures, the bipedal kangaroo rat, he says, helps maintain its body temperature using a clever nasal architecture.On exhaling, the rat's nasal passageways are heated by the outgoing air. When it inhales, those warmed passageways heat the incoming air. This heat exchange ensures little body heat is lost.Home comforts
Vogel wondered if a house or apartment could be made to breathe this way – gaining fresh air with low heat loss – and he built a model of a one-room dwelling to try it. He calls it the Nose House.Using two fan-driven heat exchangers, he was able to mimic the rodent's trick. As one exchanger pushes air into the room, the other lets air out – then their roles reverse.Each exchanger comprises a 40-centimetre-long plywood chamber, 5-centimetres-square in cross-section. Inside each chamber there are 17 half-millimetre thick aluminium plates that store heat as warm air leaves it, and which warm the air that is sucked in on the next "breath"."This was as crude an analogy as I can imagine but it worked," Vogel says. "This non-optimised version saved over half the heat that would have been lost using steady-flow fans alone. "Well-sealed houses are very unpleasant and this may get around it."Big problems
Vogel is not sure if his idea will scale up, though: to warm the average house, the chambers would need to be 6 metres long. But he plans to test whether the system might work. Patent searches have shown no similar heat exchange system working in anti-phase to mimic breathing, he notes.Peter Gammack, concept design director for Dyson in Malmesbury, Wiltshire, UK, is impressed. "This is a very interesting biomimetics-inspired idea. Small animals have evolved to work in very efficient ways and the clever use of two alternating heat exchangers is elegant," he says. "It could be a good way of improving air quality in buildings in an energy-efficient manner."Gammack adds that Vogel is right to be concerned about moving to full-scale machines, as Dyson discovered when developing its bladeless fan recently. "We had to extensively test even the minutest size change – it's surprising how dramatically scale affects effectiveness."Journal reference: Bioinspiration and Biomimetics, DOI:10.1088/1748-3182/4/4/046004

New Star Found in Big Dipper

http://seekeralpha.gaia.com — Fri, 11 Dec 2009 00:42:36 GMT

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SPACE.com Space.com Staff

space.com – Thu Dec 10, 10:15 am ET

The Big Dipper has a new star.

One of the stars that makes the bend in the ladle's handle, Alcor, has a smaller red dwarf companion, new observations have revealed.

Alcor is a relatively young star twice the mass of the Sun. Stars this massive are relatively rare (less than a few percent of all stars), short-lived, and bright.

Alcor and its cousins in the Big Dipper formed from the same cloud of matter about 500 million years ago, something unusual for a constellation since most of these patterns in the sky are composed of unrelated stars.

Alcor looks to be in the same position in the Big Dipper with another star, Mizar from the perspective of a viewer on Earth. In fact, both stars were used as a common test of eyesight — being able to distinguish "the rider from the horse" (as the two stars are unofficially known) — for ancient Arab, Roman and English warriors. (Mizar is the brighter of the two stars and can still be seen with the naked eye, while Alcor, a little fainter, would take relatively dark skies to see.)

One of Galileo's colleagues observed that Mizar itself is actually a double, the first binary star system resolved by a telescope. Many years later, the two components Mizar A and B were themselves determined each to be tightly orbiting binaries, altogether forming a quadruple system.

Now, Alcor, which is about 3 light-years away from the four stars of the Mizar system, also has a companion.

Watching for movement

In March, a group of astronomers attached a coronograph and adaptive optics to the 200-inch Hale Telescope at the Palomar Observatory in California and pointed it to Alcor. (Adaptive optics counteract interference from Earth's atmosphere by making swift, real-time changes in the shape of a telescope's mirror during observations.)

"Right away I spotted a faint point of light next to the star," said Neil Zimmerman, a graduate student who is working on his Ph.D. with the American Museum of Natural History in New York. "No one had reported this object before, and it was very close to Alcor, so we realized it was probably an unknown companion star."

A few months later, the team looked at the star again, hoping to prove that the two stars were companions by mapping the tiny movement of both in relation to very distant background stars as the Earth moves around the Sun, or parallactic motion. If the proposed companion were just a background star, it wouldn't move along with Alcor.

"We went back 103 days later and found the companion had the same motion as Alcor," said Ben R. Oppenheimer, Curator and Professor in the Department of Astrophysics at AMNH.

Alcor and its newly found, smaller companion, Alcor B, are both about 80 light-years away from Earth and orbit each other every 90 years or more.

Color and size

The team was also able to determine the color, brightness and even rough composition of Alcor B because the novel method of observation they use records images at many different colors simultaneously. The team determined that Alcor B is a common type of M-dwarf star or red dwarf that is about 250 times the mass of Jupiter, or roughly a quarter of the mass of our Sun. The companion is much smaller and cooler than Alcor A.

"Red dwarfs are not commonly reported around the brighter higher mass type of star that Alcor is, but we have a hunch that they are actually fairly common," Oppenheimer said. "This discovery shows that even the brightest and most familiar stars in the sky hold secrets we have yet to reveal."

The new observations are detailed in the Astrophysical Journal.
Oppenheimer and his team hope to use the same technique of looking for parallactic motion in the search for exoplanets.
"We hope to use the same technique to check that other objects we find like exoplanets are truly bound their host stars," Zimmerman said. "In fact, we anticipate other research groups hunting for exoplanets will also use this technique to speed up the discovery process."

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List of 'unsung' wildlife affected by climate change released

http://seekeralpha.gaia.com — Wed, 09 Dec 2009 18:32:12 GMT

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The Wildlife Conservation Society today released a list of animals facing new impacts by climate change, some in strange and unexpected ways.
In a new report titled "Species Feeling the Heat: Connecting Deforestation and Climate Change," the Wildlife Conservation Society profiles more than a dozen animal species and groups that are facing threats due to climate change impacts including: changing land and sea temperatures; shifting rain patterns; exposure to new pathogens and disease; and increased threats of predation.
The Wildlife Conservation Society is issuing this report as the world gathers in Copenhagen to address climate change issues and as the United Nations launches in 2010 the International Year of Biodiversity, a UN-led effort to raise awareness to reduce the constant loss of biological diversity worldwide. The Convention on Biodiversity, which emerged from the 1992 Rio Earth Summit, recently admitted that none of its 2010 biodiversity targets have been met, underscoring the dire situation wildlife around the world face from burgeoning threats such as climate change.
The report also highlights the huge role of deforestation in climate change. Nearly 20 percent of greenhouse gas emissions are the result of deforestation, more than the output of all the world's trucks, trains, cars, planes, and ships combined, so protecting the remaining swaths of the world's forests can help put the breaks on climate change.
"The image of a forlorn looking polar bear on a tiny ice floe has become the public's image of climate change in nature, but the impact reaches species in nearly every habitat in the world's wild places," said Dr. Steven E. Sanderson, President and CEO of the Wildlife Conservation Society. "In fact, our own researchers are observing direct impacts on a wide range of species across the world."
The report contains a cross-section of animal species around the globe, including:

Bicknell's thrush, a bird species that breeds and nests in the higher elevations on mountains in northeastern North America. Slight increases in temperature threaten this bird's breeding habitat.

Flamingos, a group including several species that are threatened by climate change impacts that affect the availability and quality of wetland habitat in the Caribbean, South America, Asia, and Africa.

Irrawaddy dolphin, a coastal species that relies on the flow of fresh water from estuaries in Bangladesh and elsewhere in Southeast Asia. Changes in freshwater flow and salinity may have an impact on the species long-term survival.

Musk ox, a species that exists in the harsh environment of the Arctic Tundra. This Pleistocene faces a higher predation risk by grizzly bears, as more bears may move northward into the musk oxen's tundra home.

Hawksbill turtle, an ocean-going reptile with temperature dependent biology. Specifically, higher temperatures result in more female hatchlings, a factor that could impact the species' long-term survival by skewing sex ratios.

"Aside from all of the current political disagreements on meteorological data, we can say with certainty that climate change is threatening our planet with significant losses to wildlife and wild places," added Sanderson.
Source : Wildlife Conservation Society

UN: 2000-2009 likely warmest decade on record

http://seekeralpha.gaia.com — Tue, 08 Dec 2009 18:30:49 GMT

http://news.yahoo.com/s/ap/20091208/ap_on_sc/climate
By CHARLES J. HANLEY, AP Special Correspondent

COPENHAGEN – This decade is on track to become the warmest since records began in 1850, and 2009 could rank among the top-five warmest years, the U.N. weather agency reported Tuesday on the second day of a pivotal 192-nation climate conference.

Only the United States and Canada experienced cooler conditions than average, the World Meteorological Organization said, although Alaska had the second-warmest July on record.
In central Africa and southern Asia, this will probably be the warmest year, but overall, 2009 will "be about the fifth-warmest year on record," said Michel Jarraud, secretary-general of the WMO.
The agency also noted an extreme heat wave in India in May and a heat wave in northern China in June. It said parts of China experienced their warmest year on record, and that Australia so far has had its third-warmest year. Extremely warm weather was also more frequent and intense in southern South America.
The decade 2000-2009 "is very likely to be the warmest on record, warmer than the 1990s, than the 1980s and so on," Jarraud told a news conference, holding a chart with a temperature curve pointing upward. The second warmest decade was the 1990s.
The current decade has been marked by dramatic effects of warming.
In 2007-2009, the summer melt reduced the Arctic Ocean ice cap to its smallest extent ever recorded. In the 2007-2009 International Polar Year, researchers found that Antarctica is warming more than previously believed. Almost all glaciers worldwide are retreating.
Meanwhile, such destructive species as jellyfish and bark-eating beetles are moving northward out of normal ranges, and seas expanding from warmth and glacier melt are encroaching on low-lying island states.
If 2009 ends as the fifth-warmest year, it would replace the year 2003. According to the U.S. space agency NASA, the other warmest years since 1850 have been 2005, 1998, 2007 and 2006. NASA says the differences in readings among these years are so small as to be statistically insignificant.
The U.N. agency reported that the global combined sea surface and land surface temperature for the January-October 2009 period is estimated at 0.44 degrees C (0.79 degrees F) above the 1961-1990 annual average of 14.00 degrees C (57.2 degrees F), with a margin of error of plus or minus 0.11 degrees C. Final data will be released early in 2010.
Negotiators at the two-week talks in Copenhagen turned Tuesday to "metrics," "gas inventories" and other dense technicalities, as delegates worked to craft a global deal to rein in carbon dioxide and other greenhouse gases and stem climate change.
Governments, meanwhile, jockeyed for position leading up to the finale late next week, when more than 100 national leaders, including President Barack Obama, will converge on Copenhagen for the final days of bargaining.
In a series of reports beginning in the 1990s, the Intergovernmental Panel on Climate Change, a U.N.-sponsored scientific network, has warned that unless the world is weaned away from fossil fuels to greener sources of energy, the Earth will face the consequences of ever-rising temperatures: the extinction of plant and animals, the flooding of coastal cities, more extreme weather, more drought and the spread of tropical diseases.
Some governments have reacted slowly to the warnings because of concerns over the cost to business and consumers of converting economies to new energy sources, the influence of "old energy" industries on policy, and the reluctance of societies to change their ways.
Although temperatures have fluctuated up and down in the eons before record-keeping, as determined by tree rings, ice cores and other evidence, the causes were natural. The difference now is that they are being driven up by human activity, that modern civilization has many more coastal cities and needs to feed far more people, and that scientists believe humans can head off such dangerous warming.
On Monday, when the conference opened, the Obama administration gave the talks a boost by announcing steps that could lead to new U.S. emissions controls that don't require the approval of the U.S. Congress.
The U.S. Environmental Protection Agency said scientific evidence clearly shows that greenhouse gases "threaten the public health and welfare of the American people" and that the pollutants — mainly carbon dioxide from burning fossil fuels — should be reduced, if not by Congress then by the agency responsible for enforcing air pollution.
As Congress considers the first U.S. legislation to cap carbon emissions, the EPA finding will enable the Obama administration to act on greenhouse gases without congressional action, potentially imposing federal limits on climate-changing pollution from cars, power plants and factories.
The announcement gave Obama a new card in what is expected to be tough bargaining next week at the climate conference. In preparation, Obama met with former Vice President Al Gore, who won a Nobel for his climate change efforts, at the White House on Monday.
European climate change officials welcomed the U.S. move.
"This is meaningful because it is yet a sign that the Americans have more to offer. My evaluation is that the U.S. can offer much more," EU environment spokesman Andreas Carlgren told reporters Tuesday in Stockholm.
Yvo de Boer, U.N. climate chief, said the EPA finding gives Obama "something to fall back on."
"I think that will boost people's confidence" at the Copenhagen talks in the Americans' ability to offer more, he said.
The European Union has pledged to reduce greenhouse gas emissions by 20 percent by 2020, compared with 1990, and is considering raising that to 30 percent if other governments also aim high. EU leaders will have an opportunity to make such a move at an EU summit this Thursday and Friday in Brussels.
In Britain, Prime Minister Gordon Brown urged fellow Europeans to raise their bid on reducing greenhouse gas emissions to pressure the U.S. and others to offer more at Copenhagen.
"We've got to make countries recognize that they have to be as ambitious as they say they want to be. It's not enough to say 'I may do this, I might do this, possibly I'll do this.' I want to create a situation in which the European Union is persuaded to go to 30 percent," Brown was quoted as saying by Britain's Guardian newspaper.
The EU had called for a stronger bid by the Americans, who thus far have pledged emissions cuts much less ambitious than Europe's. The U.S. has offered a 17 percent reduction in emissions from their 2005 level — comparable to a 3-4 percent cut from 1990 levels.
Whether the prospect of EPA action will satisfy such demands — and what China may now add to its earlier offer — remains to be seen. And success in the long-running climate talks hinges on more than emissions reductions. Most important, it requires commitments of financial support by rich countries for poor nations to help them cope with the impact of a changing climate.
Swedish negotiator Anders Turesson said the U.S. 17 percent reductions "are insufficient and we hope more would come out of that."
He suggested the U.S. buy more carbon credits on the international market, where emissions reductions by developing countries can be credited and sold to the industrialized world.
___
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Greenhouse Gas Carbon Dioxide Ramps Up Aspen Growth

http://seekeralpha.gaia.com — Sun, 06 Dec 2009 01:02:16 GMT

http://www.sciencedaily.com/releases/2009/12/091204092445.htm
ScienceDaily (Dec. 4, 2009) — The rising level of atmospheric carbon dioxide may be fueling more than climate change. It could also be making some trees grow like crazy.
That is the finding of a new study of natural stands of quaking aspen, one of North America's most important and widespread deciduous trees. The study, by scientists from the University of Wisconsin-Madison and the University of Minnesota at Morris (UMM) and published December 4 in the journal Global Change Biology, shows that elevated levels of atmospheric carbon dioxide during the past 50 years have boosted aspen growth rates by an astonishing 50 percent.
"Trees are already responding to a relatively nominal increase in atmospheric carbon dioxide over the past 50 years," says Rick Lindroth, a UW-Madison professor of ecology and an expert on plant responses to climate change. Lindroth, UW-Madison colleague Don Waller, and professors Christopher Cole and Jon Anderson of UMM conducted the new study.
The study's findings are important as the world's forests, which cover about 30 percent of the Earth's land surface, play an important role in regulating climate and sequestering greenhouses gases. The forests of the Northern Hemisphere, in particular, act as sinks for carbon dioxide, helping to offset the increase in levels of the greenhouse gas, widely viewed as a threat to global climate stability.
What's more, according to the study's authors, the accelerated growth rates of aspen could have widespread unknown ecological consequences. Aspen is a dominant tree in mountainous and northern forested regions of North America, including 42 million acres of Canadian forest and up to 6.5 million acres in Wisconsin and Minnesota. Aspen and their poplar cousins are considered "foundation species," meaning they exert a strong influence on the plant and animal communities and dynamics of the forest ecosystems where they reside.
"We can't forecast ecological change. It's a complicated business," explains Waller, a UW-Madison professor of botany. "For all we know, this could have very serious effects on slower growing plants and their ability to persist."
Carbon dioxide, scientists know, is food for plants, which extract it from the air and through the process of photosynthesis convert it to sugar, plant food.
Previously, scientists have shown that plants and trees in growth chambers respond to levels of carbon dioxide well above levels in the atmosphere. The new study is the first to show that aspen in their native forest environments are already growing at accelerated rates due to rising ambient levels of carbon dioxide in the atmosphere.
"It's a change hiding right in front of us," says Cole, a biologist at UMM. "Aspens respond to all sorts of things we had to account for -- water, genetics and other factors -- but the strong response to carbon dioxide surprised all of us."
The study measured the growth rates of 919 trees from Wisconsin forests dominated by aspen and birch. Trees ranging in age from 5 to 76 years old were sampled and subjected to tree-ring analysis. Comparing the tree-ring data, a measure of annual tree growth, with records of atmospheric carbon dioxide, the researchers were able to correlate increased rates of growth with changes in the chemistry of the air.
The surprising increase in growth rates for the trees sampled in the study is coupled, the authors note, with moist conditions. By contrast, aspen in the western United States do not seem to grow as fast as those in the American Midwest, most likely due to recent extended periods of drought. Also, while the researchers found that aspen grow much faster in response to elevated carbon dioxide, similar effects have not been observed in other trees species, notably oak and pine.
Findings from the new study, the authors note, could augur revisions of the estimates of how much carbon northern temperate northern forests can sequester.
"Forests will continue to be important to soak up anthropogenic carbon dioxide," says Waller. "But we can't conclude that aspen forests are going to soak up excess carbon dioxide. This is going to plateau."
"Aspens are already doing their best to mitigate our inputs," agrees Cole. "The existing trees are going to max out in a couple of decades."
The new study was funded by the National Science Foundation and UMM.

Hacked archive provides fodder for climate sceptics

http://seekeralpha.gaia.com — Thu, 03 Dec 2009 06:05:00 GMT

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18:01 24 November 2009 by Fred Pearce

Climate scientists are reeling this week from the discovery that someone has hacked into the email archive of one of their most prestigious research centres, the Climate Research Unit (CRU) of the University of East Anglia, UK, custodian of the most respected global temperature record.Climate sceptics have gleefully blogged that the emails, now widely published on the internet, reveal extensive data manipulation and expose a conspiracy behind global warming research. An analysis by New Scientist finds scant evidence of data abuse, but does show persistent efforts to suppress work by climate sceptics.Mostly the researchers are exposed as doing what they are supposed to do: engaging in an often adversarial process to arrive at the truth. One long exchange ends: "This is ultimately about science, it's not personal."Those contacted by New Scientist by and large had simple explanations for their statements. One 1999 email by Phil Jones, director of the CRU, has been the focus of media coverage since news of the leak broke last Thursday. In it, Jones discusses using "Mike's Nature trick" to "hide the decline" in temperatures. "Mike" Mann, of Pennsylvania State University in University Park, told New Scientist the "trick" was simply a published device to extend to the present a graph of temperatures derived from the analysis of tree ring data. This is done using real thermometer data.
Ostracising critics
What will prove more damaging is evidence that the researchers, who often attack their critics for not publishing in peer-reviewed journals, have sought to ostracise journals that did publish them.In a 2003 email, Mann discusses encouraging colleagues to "no longer submit [papers] to, or cite papers in" Climate Research, after it published papers by known sceptics "that couldn't get published in a reputable journal". Mann says his complaint was that the peer-review process had been distorted to allow "extremely poor papers" to be published and points out that the journal's editor-in-chief and half the editorial board had resigned in protest.But other comments are more difficult to justify. In 2004, Jones said of two published papers he regards as flawed: "I can't see either… being in the next Intergovernmental Panel on Climate Change report. Kevin [Trenberth] and I will keep them out somehow – even if we have to redefine what the peer-review literature is!""Let me assure you there was no attempt to keep any material out of the IPCC assessments," Trenberth, of the US National Center for Atmospheric Research in Boulder, Colorado, told New Scientist.The correspondence also shows researchers trying to prevent critics gaining access to raw data, notably the CRU's temperature data. Publicly, they say that much of the data is covered by confidentiality agreements that prevent them sharing it. For instance, an agreement with the UK's Met Office seen by New Scientist limits access to "bona fide researchers working on agreed scientific programmes".But equally the emails reveal researchers adamantly opposed to releasing hard-earned data to critics, to avert what they see as time-consuming harassment. This week's events suggest those decisions were ill-advised.

Hard Training May Reduce Fertility in Women

http://seekeralpha.gaia.com — Tue, 01 Dec 2009 08:45:27 GMT

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ScienceDaily (Nov. 23, 2009) — Are you a female athlete -- or just someone who likes challenging workouts -- who also wants to get pregnant? It may make sense to ease off a bit as you try to get pregnant. New research from the Norwegian University of Science and Technology (NTNU) shows that the body may not have enough energy to support both hard workouts and getting pregnant.

Roughly seven per cent of all Norwegian women are believed to have infertility problems, which means that they are unable to become pregnant during the first year of trying -- even if they might later become pregnant.
Infertility can have many causes, both medical and lifestyle-related. Known risk factors include smoking, stress, and alcohol. Being extremely under- or overweight can also play a role.
It is known, however, that elite sports women have more fertility problems than other women. But does extreme physical activity play a role in fertility among other women as well? NTNU researchers examined precisely this question in a study involving nearly 3,000 women. They found that overly frequent and hard physical exercise appears to reduce a young woman's fertility. But the decrease in fertility probably lasts only as long as the hard training.
Two vulnerable groups
The study was based on material from the Health Survey of Nord-Trøndelag from 1984-1986 and from a follow-up survey in 1995-1997. All of the women who participated were healthy and of childbearing age, and none had a history of fertility problems.
In the first survey, women responded to questions about the frequency, duration and intensity of their physical activity -- and ten years later were asked questions about pregnancy and childbirth.
The NTNU researchers also recorded other information that could have significance for the study.
"Among all these women, we found two groups who experienced an increased risk of infertility," says Sigridur Lara Gudmundsdottir, a PhD candidate in NTNU's Human Movement Science Programme. "There were those who trained almost every day. And there were those who trained until they were completely exhausted. Those who did both had the highest risk of infertility."
Age an important factor
If the women also were under 30 years old in the first study, the relationship became even more evident in both groups. Among those who reported training to exhaustion (regardless of frequency and duration), 24 per cent had fertility problems. In the group that had trained almost every day (regardless of the intensity and duration), 11 per cent reported the same.
Even when the data were adjusted for other possible contributing factors (such as body mass index, smoking, age, marital status and previous pregnancies), the researchers found that women who trained every day had a 3.5 times greater risk of impaired fertility as women who did not train at all.
"And when we compared those who trained to exhaustion to those who trained more moderately, we found that the first group had a three-fold greater risk of impaired fertility," says Gudmundsdottir.
In women who reported moderate or low activity levels, researchers found no evidence of impaired fertility.
A transient effect
But the negative effects of hard training do not appear to be permanent, the researcher says.
"The vast majority of women in the study had children in the end. And those who trained the hardest in the middle of the 1980s were actually among those who had the most children in the 1990s," she adds.
There may be various explanations for why the women who first were least fertile ended up with the most children. "We do not know if they changed their activity level during the period between the two surveys. Or if they just had trouble getting pregnant the first time, but afterwards had a hormonal profile that made it easier to get pregnant again," Gudmundsdottir said.
Too demanding?
Scientists have a theory that high levels of physical activity are so energy intensive that the body actually experiences short periods of energy deficiency, where there simply is not enough energy to maintain all the necessary hormonal mechanisms that enable fertilization.
On the other hand, previous research shows that moderate physical activity gives women better insulin function and an improved hormonal profile -- and thus better conditions for fertility -- than total inactivity, particularly in overweight people.
Forget the easy chair
But Gudmundsdottir says that women who want to become pregnant shouldn't give up all physical activity.
"We believe it is likely that physical activity at a very high or very low level has a negative effect on fertility, while moderate activity is beneficial," she says.
But as far as identifying how much is "just right," the researcher is careful. "An individual's energy metabolism is a very important factor in this context. The threshold can be very individual," Gudmundsdottir says.
She also recommends that physically active women be particularly aware of their menstrual cycles. "A long cycle or no menstruation at all are danger signals," she says.

Climate change cover-up? You better believe it

http://seekeralpha.gaia.com — Sat, 28 Nov 2009 17:03:01 GMT

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Nov 24, 2009 05:01 PM in Society & Policy
By David Biello
Was Sen. James Inhofe right when he declared 2009 the year of the climate contrarian? A slew of emails stolen from the University of East Anglia's Climatic Research Unit highlight definite character flaws among some climate scientists—including an embarrassing attempt to delete emails that discussed the most recent report from the United Nations Intergovernmental Panel on Climate Change—while also exposing what looks like a failure of scientists to acknowledge a halt to global warming in the past decade.

Sadly for the potential fate of human civilization, rumors of the demise of climate change have been much exaggerated. The past decade recorded nine of the warmest years in recent history as well as the rapid dwindling of Arctic sea ice, surely the result of imminent global cooling if climate change contrarians are to be believed. After all, one of the most "damaging" emails in question from Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colo., is actually mourning the paucity of Earth observation systems and data in the past decade, such as satellites (gutted by a lack of funding and launch miscues in recent years) to monitor climate change in the midst of natural variability.

The "Copenhagen Diagnosis" released today reveals that by any objective measure—melting ice sheets, greenhouse gas concentrations, sea level rise—the climate is warming faster than anticipated. And when the natural variability induced by massive climate systems such as oscillations over decades in ocean temperatures, currents and even sunspots reverts to the mean, the roughly three warming watts per square meter added by greenhouse gases will still be there to drive climate change.

You can judge the emails for yourself at this wonderful searchable database. While the revelations about pressuring the peer review process and apparent slowness in responding to an avalanche of requests for information unveil something below impressive scientific and personal behavior, they can also be seen as the frustrated responses of people working on complex data under deadline while being harassed by political opponents.

Note the adjective there. Political, not scientific, opponents. Because the opposition here is not grounded in any robust scientific theory or alternative hypotheses (all of those, in their time, have been shot down and nothing new has been offered in years) but a hysterical reaction to the possibly of what? One-world government? The return of communism? If that's the fear, perhaps someone can explain why the preferred solution to climate change offered by former proponents of inaction is nuclear power. Has there ever been a nuclear reactor built anywhere in the world that didn't rely on government to get it done? Sounds like socialism, doesn't it? Hello France? USSR? USA?

The problem is not the behavior of climate scientists or their results. The problem is fear of the actions required to actually deal with the findings of climate science, and it has turned the field into a contact sport as Stephen Schneider of Stanford University puts it in the title of his new book. For example, we might decide to start cutting emissions of greenhouse gases, perhaps by restraining our burning of fossil fuel, or at least capturing and storing the carbon dioxide emitted in that process. It would appear, in fact, that the Obama administration will actually bring to the climate conference in Copenhagen some kind of a proposal to reduce U.S. greenhouse gas emissions.

That's not something some folks want to see, primarily those working in the fossil fuel extraction and/or burning business.

There is, in fact, a climate conspiracy. It just happens to be one launched by the fossil fuel industry to obscure the truth about climate change and delay any action. And this release of emails right before the Copenhagen conference is just another salvo—and a highly effective one—in that public relations battle, redolent with the scent of the same flaks and hacks who brought you "smoking isn't dangerous."

As physicist and climate historian Spencer Weart told The Washington Post: "It's a symptom of something entirely new in the history of science: Aside from crackpots who complain that a conspiracy is suppressing their personal discoveries, we've never before seen a set of people accuse an entire community of scientists of deliberate deception and other professional malfeasance. Even the tobacco companies never tried to slander legitimate cancer researchers." Well, probably they did, but point taken.
Image: University of East AngliaRead More About: climate change, global warming

Intensive Land Management Leaves Europe Without Carbon Sinks

http://seekeralpha.gaia.com — Tue, 24 Nov 2009 05:33:37 GMT

http://www.sciencedaily.com/releases/2009/11/091123114636.htm
ScienceDaily (Nov. 23, 2009) — Of all global carbon dioxide emissions, less than half accumulate in the atmosphere where it contributes to global warming. The remainder is hidden away in oceans and terrestrial ecosystems such as forests, grasslands and peat-lands. Stimulating this "free service" of aquatic and terrestrial ecosystems is considered one of the main, immediately available ways of reducing climate change. However, new greenhouse gas bookkeeping has revealed that for the European continent this service isn't free after all.

These findings were recently published in Nature Geoscience.
Researchers from 17 European countries cooperating in the EU-Integrated Project CarboEurope, led by Detlef Schulze, of the Max Planck Institute for Biogeochemistry in Jena, Germany have compiled the first comprehensive greenhouse gas balance of Europe. They made two independent estimates: one based on what the atmosphere sees and one based on what terrestrial ecosystems see.
The new bookkeeping effort confirmed the existence of a strong carbon sink of -305 Million tonnes of carbon per year in European forests and grasslands. A sink of this magnitude could offset 19% of the emission from fossil fuel burning. However, agricultural land and drained peat-land are emitting CO2, which cancels part of this sink. The resulting net CO2 sink of the European continent is 274 Million tonnes of carbon per year -- only 15% of the emissions from fossil fuel burning. But this balance is still incomplete, because all European ecosystems are managed and as a by-product of land management other powerful greenhouse gases are released -- for example nitrous oxide from fertilizers applied to grassland and crops, and methane from ruminants and from peat-lands. These previously neglected emissions of greenhouse gases from land-use cancel out almost the entire carbon sink, leaving the landscape offsetting only some 2% of the CO2 emissions from households, transport and industry.
Compared to Europe as a whole, the situation is even worse for the 25 states of the European Union. Here, although forests and grasslands can compensate for 13% of the CO2 emitted by fossil fuel burning, emission of powerful greenhouse gases from agricultural emissions and peat mining reduces the effectiveness of the land surface sink to 111 Million tonnes of carbon per year, which is only 11% of the CO2 emitted by fossil fuels. However, since the emissions of methane and nitrous oxide are relatively higher in the European Union the land surface emerges as a greenhouse gas source of 34 Million tonnes of carbon per year. This effectively increases the emissions from fossil fuel burning by another 3%.
Prof Schulze said "These findings show that if the European landscape is to contribute to mitigating global warming, we need a new, different emphasis on land management. Methane and nitrous oxide are such powerful greenhouse gases; we must manage the landscape to decrease their emissions."

Malaria shows signs of resisting best drug used to fight it

http://seekeralpha.gaia.com — Sat, 21 Nov 2009 05:18:35 GMT

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The frontline malaria medicine artemisinin shows gaps in effectiveness in Southeast Asia
By Nathan Seppa
Web edition : Thursday, November 19th, 2009

WASHINGTON — Malaria that is resistant to the best available drug is more widespread in Southeast Asia than previously reported, new research shows. The worrisome finding poses a risk that travelers could carry this strain of the malaria parasite to other parts of the globe and unwittingly spread it, scientists reported November 19 at a meeting of the American Society of Tropical Medicine and Hygiene.
The frontline drug in question is called artemisinin, the most potent medication currently in use against malaria. Signs of malarial resistance to artemisinin have surfaced over the past several years in Cambodia (SN: 11/22/08, p. 9). The new findings confirm that resistant malaria has now cropped up beyond a spot on the border of Thailand and Cambodia where it was initially detected. Now it has appeared in Vietnam and in two spots along the Burma border with Thailand and China.
“Things are changing. There’s no doubt the signs are concerning,” said Robert Newman, director of the Global Malaria Programme at the World Health Organization in Geneva. But he added that these signals are early and need further verification.
Patients in these areas take longer on average to overcome a malaria infection when given a standard combination of artemisinin and another antimalarial. This lag results from slower clearance of the malaria parasites from the blood, said WHO’s Pascal Ringwald, a medical officer who presented the update.
Patients who remain ill for longer stretches despite treatment need extra medication to recover from malaria and are also more likely to have severe or fatal cases, Ringwald said.
Malaria is caused by a single-celled parasite that infects the blood. Symptoms include fever, headache, chills, anemia and a swollen spleen. Of the more than 350 million people who come down with malaria worldwide each year, up to 1 million die. Mosquitoes spread the parasite from person to person.
Malaria has a history of becoming resistant to drugs, and artemisinin now risks becoming the most recent addition to that list. The new reports are disheartening to doctors because artemisinin normally packs a considerable wallop. Although artemisinin is a short-acting drug that gets cleared from the body in a few hours, it makes the most of its time — driving down parasite levels dramatically.
Using artemisinin alone invites resistance. So the standard therapy teams it with one of the longer-acting drugs, which perform mop-up duty on the remaining parasites, said Christopher King, a physician and epidemiologist at Case Western Reserve University in Cleveland.
The new flashes of resistance may have arisen because combination treatment isn’t always available. And since artemisinin can be bought over the counter in many parts of Asia, people seeking relief don’t always follow the WHO guidelines of pairing artemisinin with another drug, King said.
Also, taking artemisinin for a fever that isn’t caused by malaria can allow resistant strains of the parasite to take hold, Newman said.
In the past, malaria’s resistance to other drugs has been linked to specific genetic changes in the parasite. The precise mechanism underlying resistance to artemisinin is still unsolved, King said.
Artemisinin is derived from extracts of the sweet wormwood bush. The bush’s leaves have been used as a folk remedy against fevers for roughly 2,000 years in Asia but fell out of use in the 20th century with the introduction of modern antimalarial drugs such as chloroquine.
During the Vietnam War, North Vietnamese leader Ho Chi Minh appealed to China for traditional remedies for soldiers who had malaria. Tea made from sweet wormwood leaves worked and ultimately became the basis for artemisinin drugs. It’s not clear whether parasites in Southeast Asia are the first to become resistant because they have had a long history with artemisinin, or if other factors are involved, Newman said.

Dozen Lesser-Known Chemicals Have Strong Impact on Climate Change

http://seekeralpha.gaia.com — Thu, 19 Nov 2009 04:21:30 GMT

http://www.sciencedaily.com/releases/2009/11/091117102036.htm

ScienceDaily (Nov. 18, 2009) — A new study indicates that major chemicals most often cited as leading causes of climate change, such as carbon dioxide and methane, are outclassed in their warming potential by compounds receiving less attention.Purdue University and NASA examined more than a dozen chemicals, most of which are generated by humans, and have developed a blueprint for the underlying molecular machinery of global warming. The results appear in a special edition of the American Chemical Society's Journal of Physical Chemistry A, released Nov. 12.

The compounds, which contain fluorine atoms, are far more efficient at blocking radiation in the "atmospheric window," said Purdue Professor Joseph Francisco, who helped author the study. The atmospheric window is the frequency in the infrared region through which radiation from Earth is released into space, helping to cool the planet. When that radiation is trapped instead of being released, a "greenhouse effect" results, warming the globe. Most of the chemicals in question are used industrially, he said.

NASA scientist Timothy Lee, lead author of the study with Francisco and NASA postdoctoral fellow Partha Bera, characterized the fluorinated compounds as having the potential to quickly slam the atmospheric window shut, as opposed to gradually easing it shut like carbon dioxide.

In the results, chemicals such as chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur and nitrogen fluorides stood out in their warming potential because of their efficiency to trap radiation in the atmospheric window.

"It's actually rather stark," said Francisco, a Purdue chemistry and earth and atmospheric sciences professor, whose research focuses on the chemistry of molecules in the atmosphere.
An understanding of how the chemicals contribute to climate change on a molecular scale affords the opportunity to create benign alternatives and to test new chemicals for their global warming capability before they go to market, Francisco said.
"Now you have a rational design basis," he said.

The researchers looked at more than a dozen chemicals, often referred to as "greenhouse gases," listed as warming agents by the Intergovernmental Panel on Climate Change, the most prominent international scientific group monitoring global warming. The study employed both results from experimental observations and from computer modeling using supercomputers from Information Technology at Purdue (ITaP), Purdue's central information technology organization, and NASA. The goal was to determine which chemical and physical properties are most important in contributing to global warming.

"Believe it or not, nobody has ever delineated these properties," Lee said.

CFC use has waned with the discovery that the chemicals contribute to the destruction of Earth's ozone layer, which absorbs most of the dangerous ultraviolet radiation from the sun. But HFCs and PFCs are widely used in air conditioning and the manufacturing of electronics, appliances and carpets. Other uses range from application as a blood substitute in transfusions to tracking leaks in natural gas lines.

"Although current concentrations of some of these trace gases have been found to be substantially small compared to carbon dioxide, their concentration is on the rise," the study notes. "With the current rate of increase, they will be important contributors in the future, according to some models."

The fluorine atoms that characterize the chemicals are highly electro-negative and tend to pull electrons to themselves, Francisco said. This shift makes the molecules more efficient at absorbing radiation, which would normally bleed harmlessly into space. As a result, the fluorine-containing compounds are the most effective global warming agents, the study concludes.
The compounds also persist longer than carbon dioxide and other major global warming agents, said Lee, chief of the Space Science and Astrobiology Division at NASA Ames Research Center. The concern is that, even if emitted into the atmosphere in lower quantities, the chemicals might have a powerful cumulative effect over time. Some of these chemicals don't break down for thousands of years.

The research was supported by NASA.

Study Finds Missing Link in How Stars Die

http://seekeralpha.gaia.com — Sat, 14 Nov 2009 14:15:55 GMT

http://www.space.com/scienceastronomy/091112-two-new-white-dwarfs.html

By Clara Moskowitz
Staff Writer
posted: 12 November 2009
02:00 pm ET
How stars end their lives depends on how massive they are.Large stars are thought to die in explosive fits and collapse into the densest objects in the universe — black holes and neutron stars. Small stars languish as dim objects called white dwarfs. But what happens to stars right on the border is not certain. Now astronomers have observed two peculiar white dwarfs that may represent the end point for these objects.White dwarfs can be about the size of Earth, but contain roughly the mass of the sun. They have already burned up most of their fuel and shine weakly by releasing heat. Most white dwarfs are made of compacted carbon and oxygen, with small amounts of a few other elements.The new observations found, for the first time, two white dwarfs that contained much more oxygen than carbon, perhaps representing the end stage for stars that are between seven and 10 times the mass of the sun — just under the mass threshold for neutron stars and black holes."These are literally the first two white dwarfs which have this kind of chemical composition," said Boris Gänsicke of the University of Warwick, lead author of a paper describing the finding in the Nov. 13 issue of the journal Science. "These stars may define the upper boundary of stars that can make white dwarfs."The stars, called SDSS 0922+2928 and SDSS 1102+2054, are 400 and 220 light-years from Earth, respectively.While stars are still young they power themselves by burning hydrogen and helium in nuclear fusion reactions in their cores. Our sun is still doing this, but at some point in a star's life, it will run out of this fuel and its gaseous outer layers will puff up and float out into space. Then the inner parts will condense; just how compacted they get depends on the star's mass. The hugest stars will crumple all the way down to neutron stars or even black holes, while the majority of stars will stop at the white dwarf stage. This is the predicted fate of our sun.But the most massive of white dwarfs will undergo another period of nuclear fusion where they burn up carbon to form the element neon. That's what researchers think the newly-discovered stars are."Models predict that if you go to the top end of the mass range of white dwarfs, they manage to burn most of the carbon layer," Gänsicke told SPACE.com. "These two stars definitely have lower abundances of carbon."The researchers discovered the stars using spectroscopy data from the Sloan Digital Sky Survey. They hope to take more detailed follow-up measurements that could confirm whether there is neon present in the stars, which would result from the carbon burning.