SALT LAKE CITY — Nearly two decades after vets began returning from the Middle East complaining of Gulf War Syndrome, the federal government has yet to formally accept that their vague jumble of symptoms constitutes a legitimate illness. Here, at the Society of Toxicology annual meeting, yesterday, researchers rolled out a host of brain images — various types of magnetic-resonance scans and brain-wave measurements — that they say graphically and unambiguously depict Gulf War Syndrome.

Or syndromes. Because Robert Haley of the University of Texas Southwestern Medical Center in Dallas and the research team he heads have identified three discrete subtypes. Each is characterized by a different suite of symptoms. And the new imaging linked each illness with a distinct — and different — series of abnormalities in the brain.

Men with the same symptoms exhibited similar brain changes, features starkly different from healthy vets their age who had served in the same battalions. (That said, a few vets’ symptoms seemed to encompass more than one syndrome. And in such instances, imaging confirmed their brains showed impairments that extended beyond those associated with a single syndrome.)

Since the early 1990s, some 175,000 U.S. troops have returned from service in the first Gulf War reporting a host of vague complaints, notes Richard Briggs, a physical chemist at UT Southwestern involved in the new imaging. Their symptoms ranged from mental confusion, difficulty concentrating, attacks of sudden vertigo and intense uncontrollable mood swings to extreme fatigue and sometimes numbness — or the opposite, constant body pain.

With funding from the Departments of Defense and Veterans Affairs, Haley has assembled a team of roughly 140 researchers. Many work with patients. Others are developing new animal, biochemical and genetic studies to identify the biological perturbations underlying Gulf War Illness. But the vast majority — two-thirds of these scientists — are now involved in brain imaging.

As a result of these studies, Briggs says, “In the last two years we have learned more about Gulf War Illness than we did in the previous 15.”

What’s emerged is evidence to suggest “that there are three major syndromes responsible for Gulf War Illness,” he says. They appear loosely linked to at least three different types of agents to which many troops were exposed: sarin nerve gas, a nerve gas antidote (pyridostigmine bromide) that presented its own risks and military-grade pesticides to prevent illness from sand flies and other noxious pests. But Briggs acknowledges that no one knows for sure which combination of agents or environmental conditions might have conspired to trigger Gulf War illness.

What is clear, he says, is that “our data now clearly show, beyond a shadow of a doubt, that there are brain abnormalities — physiological differences — between ill veterans and normal ones.” And from the new scans, “we can tell the ill veterans from the well veterans. And we can distinguish syndromes one, two and three from each other.”

The new neuroimaging on a subset of 57 Gulf War vets was completed eight months ago. Yesterday’s presentations represent an unveiling of the complex statistical analyses of data gleaned from those functional MRI scans (or fMRIs), brain-wave recordings and other magnetic resonance tools.

Some testing employed old-style technologies. For instance, about a dozen years ago, Haley’s team performed magnetic resonance spectroscopy, also known as MRS, to study the chemical composition of various regions in the brains of Gulf War vets. And these tests uncovered the first solid indicators that there were physiological abnormalities in men complaining of Gulf War Illness. Such as a perturbation in the ratio of two chemicals active in the brain’s basal ganglia: n-acetyl aspartate (or NAA) and creatine.

Don’t know what that means? I didn’t either. So Briggs explained.

“The basal ganglia is sort of the switching system of the brain. It’s where a lot of communication between the left and right hemispheres occurs.” Because it crosses the midbrain region, he says, “it’s heavily involved in a lot of these decisionmaking and attention/inhibition networks” – processing centers that, if messed up, could explain many symptoms reported by sick vets.

NAA is a biomarker of healthy nerve cells. So any decrease is a bad sign. The concentration of creatine, which comprises the fuel for brain activities, tends to remain constant, Briggs says, so “it’s often used as an internal standard” against which to compare things like NAA.

The Gulf War syndromes are each associated with a roughly 10 percent lower than normal NAA-to-creatine ratio in the left and right basal ganglia, Briggs says — “an indicator of either sick or dead neurons.”

After Haley’s team initially published evidence in the late ’90s of the diminished NAA-to-creatine ratio in sick vets, two other labs confirmed this characteristic MRS feature in sick Gulf War veterans, Briggs notes. More recently, when one of those labs failed to reconfirm those changes during a followup study, the UT Southwestern team began to wonder whether it had erred the first time it had conducted the pioneering tests. Or whether the sick vets had simply gotten well over the past 10 years.

“Our new follow-up [MRS] tests now show our initial findings were right,” Haley says, “and that the soldiers haven’t gotten better with time.”

Many of scans that his team unveiled here at SOT rely on a technology (fMRI) that was not available in the late ’90s. So it provides new evidence of what sets sick vets apart.

This technology allows researchers to identify which areas are active as the brain works. Haley’s multicenter team designed a series of fMRI tests that required subjects to look at threatening pictures of a battlefield, or imagine the theme behind two words to come up with a third (”desert” and “humps” might be the clues given to suggest “camel”), or to learn words and recall faces.

In healthy veterans, appropriate parts of the brain lit up as they thought, reasoned, viewed — even experienced extremes of temperature. But in men suffering from Gulf War Illness, Haley says, “a different part would often light up as their brain attempted to work around its damage.”

Affected areas of the brain in each test varied. The thalamus, for example, is involved in attention and inhibition, Briggs explains. “It is activated differently in syndrome two versus controls,” he notes. Not surprisingly, people with that particular syndrome have problems with those traits. The researchers also correlated what combinations of areas in the brain respond in concert during particular tasks. And sometimes, the collection of brain locales that lit up in sick vets differed markedly from those in healthy vets (see images above).

The background volume of blood flowing through the brain also varied substantially in sick vets, Haley notes, “which suggests decreased [brain] function.” But even more importantly, blood flow varied in unpredictable ways when the sick Gulf War veterans were administered a drug meant to stimulate parts of the brain susceptible to chemical damage, such as nerve-gas-type agents.

In healthy vets and those suffering from syndrome one, blood flow to affected regions of the brain diminished, although not comparably; the drop in syndrome-one vets was about five times that in the healthy men. But among individuals suffering from Gulf War syndromes two and three, blood flow inappropriately spiked after administration of the drug.

Other tests probed for faults in the integrity of the circuitry connecting deep gray matter — where the brain performs unconscious calculations and processing — with the layer of white matter that performs conscious reasoning. In vets with syndrome two, the most seriously ill of the groups, a special form of scans showed signs that the insulating sheath covering the “wires” connecting the gray and white-matter regions was seriously impaired.

Concludes Briggs: “This tells us very clearly that in the syndrome twos — unlike either of the other syndromes, or the controls — their wiring is flawed.”

The panoply of quantitative changes being revealed by brain imaging “is demystifying Gulf War Syndrome,” says Haley. Indeed, before long, he predicts, “we’re going to come up with tests whereby doctors can diagnose affected vets.” And one day, he hopes, the information emerging from these images may actually point toward treatments.

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Wind power has made incredible inroads into the U.S. energy system thanks to big, efficient machines standing hundreds of feet tall. But the future of wind power may be underground.

In the abandoned mines and sandstones of the Midwest, compressed-air storage ventures are trying to convert the intermittent motions of the air into the kind of steady power that could displace coal.

Compressed-air energy storage plants use compressors to store electricity generated when it’s not needed. The air, pumped into large underground formations, is like a spring that’s been squeezed and when it’s needed, it can deliver a large percentage of the energy that it received.

The first and only such plant in the United States went online in 1991, and though the technology didn’t take off, it did prove that it worked. And now, combining cheap wind energy and compressed-air storage could create a potent new force in the electricity markets.

“This is the first nonhydro renewables technology that can replace coal in the dispatch order,” said David Marcus, co-founder of General Compression, a new company that received $16 million in funding from investors including the utility Duke Energy to build a full-scale prototype of their energy storage system, which would be deployed with arrays of wind turbines.

The dispatch order is how grid operators decide which power plants to switch on. They have to balance the amount of generation and consumption or they risk the grid’s stability. The amount of power people use goes up and down, but it stays above a certain level all the time. To meet that need, utilities buy consistent always-on power from the large, cheap coal and nuclear power plants that are the backbone of the electric grid.

The electricity they need to meet the peaks in energy demand is generated by what are known as peaking plants, usually powered by natural gas. When the wind is blowing, it is usually the cheapest peaking power available, so it keeps the natural gas plants shut off. If they want to replace coal plants in the pecking order, though, they’ll have to work all the time.

And to do that, they’ll need a way to unlink themselves from the on-again, off-again nature of the wind.

“It’s a fractal problem,” said Marcus. “You have intermittency problems on every time scale.”

That problem has brought compressed-air energy storage roaring back. Marcus’ company has a long way to go before they can turn their prototype system into the kind of technology that can be deployed at the nation’s vast wind farms. But compressed air storage of one type or another is on the verge of becoming a mainstream power technology.

The nation’s largest energy storage option right now is pumped hydroelectricity. When excess electricity is present in a system, it can be used to pump water up to a reservoir. Then, when that power is needed, the water is sent through a turbine to generate electricity. The U.S. electric system has 2.5 gigawatts of pumped hydro storage capacity, but most of the good, cheap sites are already occupied, and creating new reservoirs is not environmentally benign.

While wind farmers say storage isn’t technically necessary until the amount of wind power on the grid exceeds 20 or 30 percent of the electrical load, private analysts, the Electric Power Research Institute, and the Department of Energy have identified grid-scale storage as a key need for the rapidly diversifying electricity system.

And going forward, compressed-air energy storage looks like the cheapest option available. Independent analysts have come to similar conclusions.

“CAES is the least cost, utility-scale, bulk-storage system available. If other factors such as its low environmental impact and high reliability are considered, CAES has an overwhelming advantage,” one Department of Homeland Security physicist concluded in a 2007 paper in the journal Energy.

In the last four months, four projects have gotten new funding. In December, the rights to a long-awaited project in Norton, Ohio, were purchased by First Energy, a large utility in the area. The Norton project could store 2.7 gigawatts of power in an abandoned limestone mine.

In California, PG&E received a $24.9 million grant from the Energy Department to build a 300-megawatt plant in Kern County. New York State Electric and Gas received $29 million for a similar facility in the town of Reading, New York, using an existing salt cavern there. The Iowa Stored Energy Project received a $3.2 million forgivable loan from the state and will finish drilling its first research well in the next month. The plan is to attempt to store energy in porous sandstone, just like the 1.7 trillion cubic feet of natural gas that lie beneath the surface of the United States.

The man behind the technology slated to be used in the two Energy Department-backed projects is engineer Michael Nakhamkin, founder of Energy Storage Power Corporation. He designed the only U.S. compressed air storage plant, in McIntosh, Alabama.

That plant was built in the late 1980s by a very small southern utility, the Alabama Electric Cooperative. They had a unique problem, Nakhamkin said, in that their daytime load far exceeded their nighttime load, the opposite of the regular pattern.

The big coal plant they needed to meet the daytime demand made too much power at night. Turning down the plant at night wasn’t a good solution because coal plants work most efficiently at full capacity, and turning them down makes them dirtier. And even with the plant at full power during the day, the utility still had to buy power from other companies to meet their peak daytime demand.

But with a storage plant, they could use the extra electricity made at night to satisfy their daytime peak demand.

Based on the first commercial plant (.pdf) ever built in Huntorf, Germany, the Electric Power Research Institute and Nakhamkin’s engineering firm came up with a plan to store compressed air in a salt dome in Alabama. They created a geological pocket 900 feet long and up to 238 feet wide in the dome by pumping water into it to dissolve the rock salt. When the (briny) water was pumped back out, the salt resealed itself and they had an air-tight container: “The solution-mined cavern is a large subterranean pressure vessel,” as an EPRI report explained.

During off-peak times, electricity runs a compressor which pumps the air down into the cavern. Then, when energy is needed, the air is released from the reserve to power a fairly standard turbine, with a little help from natural gas. The system has worked for more than 25 years.

In 1991, when the plant went online, there were high hopes that the technology might catch on among utilities.

‘We expect the CAES plant technology pioneered in Alabama to lead to widespread application in this country,” said Robert Schainker, the manager of the Electric Power Research Institute’s Energy Storage Program in a press release announcing the plant’s completion. ‘Three fourths of the United States has geology suitable for underground air storage. At present, more than a dozen utilities are evaluating sites for CAES application.”

But with low fossil fuel prices and little intermittent renewable energy on the grid, there wasn’t much incentive for utilities to build the plants. The plant saved money for the Alabama Electric Cooperative, but it wasn’t “critical savings” as Nakhamkin put it.

“Rich people don’t talk about how to save five or 10 dollars,” he said.

Planning for the Iowa Stored Energy Project began in 2001, but at the time, it just didn’t make economic sense for the small municipal utilities involved.

“Without a lot of renewables, the business model for CAES is not that strong,” Holst said. With wind sometimes producing as much as 15 percent of Iowa’s electricity, the case for the business gets stronger every day.

Nakhamkin thinks the time has come for compressed air to take off, particularly with the new plant designs that incorporate the data from the McIntosh plant.

“We analyzed several years of plant operation and from this, we generated a second generation of CAES technology,” he said. “It’s much more reliable and much more adjustable for the smart grid, for solar energy and a variety of wind power plants.”

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An extra-tall wave struck a cruise ship off the Mediterranean coast of Spain this week, claiming two lives and injuring one person on board. Though the wave may not qualify as a “rogue wave,” it could have been created by the same forces.

To officially be rogue, the wave’s height must be more than double the “significant wave height” of the area, which is calculated by averaging the height of the tallest third of all the nearby waves.

The wave measured 26 feet tall and shattered plate-glass windows at the bow of the vessel. Still, it wasn’t very tall compared to some of the waves oceanographer Libe Washburn of UC Santa Barbara has seen.

“I was surprised it was really that damaged by a 26-foot-high wave,” Washburn said. “Twenty-six feet isn’t that big.”

Until recently, scientists were skeptical that rogue waves even exist, because evidence of them was mostly anecdotal. More often called “freak waves,” these monsters of the sea were confirmed only six years ago by satellite images and extensive studies carried out by MaxWave, a research group funded by the European Commission.

Waves over 100 feet tall have been spotted by oceanographers, scientists and vessel passengers. The highest wave ever recorded was 112 feet tall, spotted in the Pacific by a U.S. Navy tanker in the 1920s. Now, whenever large ships get lost at sea and never return, many are quick to speculate they were victims of rogue waves.

Rogue waves occur in the open ocean in a number of ways. One common cause is when two smaller waves coalesce to produce a very large wave for a short time.

“You get waves that add up — smaller waves that constructively interfere and for a short time produce a very large wave,” Washburn said. “When they add up, they can make an extra high crest and an extra deep trough.”

Another way rogue waves propagate is when an ocean wave encounters a very strong current that’s running counter to the direction of the wave, according to Washburn. The Agulhas Current, which flows down the eastern coast of South Africa, is notorious for producing rogue waves.

“It’s very dangerous at the Agulhas,” Washburn said. “Even if you’re on a big ship, that doesn’t mean you’re any safer.”

Storm-related wind is a factor as well. Strong winds transfer energy into the waves, creating interactions between them. Large waves take energy from smaller ones, creating a bigger and bigger wave, said oceanographer Peter Challenor of the National Oceanography Centre in the United Kingdom, in an interview with Agence France-Presse.

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A moon probe has found millions of tons of water on the moon’s north pole, NASA reported Monday. The vast source of water could one day be used to generate oxygen or sustain a moon base.

A NASA radar aboard India’s Chandrayaan-I lunar orbiter found 40 craters, ranging in size from 1 to 9 miles across, with pockets of ice. Scientists estimate at least 600 million tons of ice could be entombed in these craters.

The radar, called the Mini-SAR, sends pulses of left-polarized radio waves out to measure the surface roughness of the moon. While smooth surfaces send back a reversed, right-polarized wave, rough areas return left-polarized waves.

Ice, which is transparent to radio waves, also sends back left-polarized waves. The Mini-SAR measures the ratio of left to right circular polarized power sent back, or the circular polarized ratio (CPR). However, a high CPR alone can’t distinguish between rough patches and regions with ice.

The north pole craters had a high CPR on the inside, with a low CPR on the edges. That suggests a material enclosed in the craters, rather than surface roughness, caused the high CPR signal. According to NASA, the ice would have to be relatively pure ice and at least several feet thick to give this signature.

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The connection between gut bacteria and obesity has gained some weight, with new findings demonstrating links in mice among immune-system malfunction, bacterial imbalance and increased appetite.

Mice with altered immune systems developed metabolic disorders and were prone to overeating. When microbes from their stomachs were transplanted into other mice, they also become obese.

“This supports the notion that some of the increase in obesity may be because of changes to gut bacteria,” said Andrew Gewirtz, an Emory University immunologist and co-author of the study, published March 4 in Science.

The findings are the latest in a growing body of research about the long-unappreciated role of bacteria in our bodies. Bacterial cells actually outnumber human cells in the body: From an outside perspective, people are not so much individual organisms as symbiotic human-bacteria collectives.

Disturbances to internal bacteria have been linked to asthma, cancer and many autoimmune diseases. Gut flora have also been linked to obesity. In 2006, researchers led by Washington University microbiologist Jeffrey Gordon documented bacterial changes in the stomachs of mice who became obese on high-fat diets.

When transplanted, their gut bugs turned other mice obese, suggesting that altered bacteria were not only an effect of weight gain, but a cause. The Science findings complement those, but also emphasize the immune system’s role and the possibility of appetite change.

“The reason why people are eating too much may not simply be because unhealthy food is cheap and available, but that their appetites may be driven by changes in gut bacteria,” said Gewirtz,

In the Science study, Gewirtz and Emery microbiologist Matam Vijay-Kumar studied a strain of mice deficient in TLR-5, a gene that’s required for immune systems to recognize many types of bacteria.

They found that TLR-5–deficient mice are about 20 percent heavier than regular mice. They overeat, have high blood pressure and high cholesterol, and are insulin-resistant. In humans, that constellation of conditions is known as metabolic syndrome, and in both people and mice leads to obesity and diabetes.

Earlier research had found unusual patterns of bacteria in the guts of those mice. When the researchers transferred bacteria from the stomachs of TLR-5–deficient mice to mice without gut bacteria, the recipients started to eat more, and soon developed metabolic syndrome.

“It’s a really exciting paper. It confirms and supports a lot of the findings we’ve had, and adds in the interaction between gut bacteria and the immune system,” said Peter Turnbaugh, a systems biologist who moved from Jeffrey Gordon’s lab to Harvard University. “It’s been thought for a long time that maybe the immune system is an important regulator of what’s in the gut.”

How gut bacteria produce metabolic changes isn’t known. They may process nutrients directly, or alter the activity of metabolism-regulating genes.

Mice used in the research are not considered exact models of bacteria and obesity in humans. Instead they’re models of these sorts of relationships likely to exist in people. Gewirtz’s team is now investigating whether people with metabolic syndrome have unusual gut bacteria.

The findings don’t suggest obesity is literally contagious, said Turnbaugh. But they do raise the possibility of altering the composition of gut bacteria, either directly or — more realistically — by learning what sort of environmental and lifestyle factors produce obesity-causing bugs.

One possible culprit is the ubiquitous presence of antibiotics, both prescribed and in the environment, said Gewirtz.

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Prodigious plumes of planet-warming methane are bubbling from sediments across a broad region of Arctic seafloor previously thought to be sealed by permafrost, new analyses indicate. The resulting increase of methane gas in the atmosphere may accelerate climate warming, scientists say.

sciencenewsThough immense amounts of carbon are known to be trapped in the peatlands of Siberia, a larger, often unrecognized carbon reservoir lies hidden just north of that frigid region, says Natalia Shakhova, a biogeochemist at the University of Alaska in Fairbanks. The East Siberian Arctic Shelf — a 2.1-million-square-kilometer patch of Arctic seafloor that was exposed during the most recent ice age, when sea levels were lower — is three times larger than all of today’s land-based Siberian wetlands. When the region was above sea level, tundra vegetation pulled carbon dioxide from the air as plants grew. That organic material, much of which didn’t decompose in the frigid Arctic, accumulated in the soil and is the source of modern methane.

Now, field studies by Shakhova and her colleagues, reported in the March 4 Science, suggest that the submarine reservoir of carbon has begun to leak.

During six cruises in the region from 2003 to 2008, the researchers gathered data at more than 1,000 spots in the Greenland-sized stretch of shallow ocean. The team also took atmospheric readings of methane concentration during one helicopter survey and a wintertime excursion from shore onto the ice-covered sea, says Shakhova.

The researchers found unexpectedly high amounts of methane dissolved in seafloor waters across 80 percent of the area they studied. In some spots, methane concentrations during those six years averaged more than 80 times normal. Because the water over the shelf is relatively shallow — average depth in the region is about 45 meters, Shakhova notes — much of the methane reaches the ocean surface and then wafts into the atmosphere.

Previously, scientists presumed that the carbon trapped in sediments on the East Siberian Arctic Shelf was sealed by permafrost, as nearby deposits on land are. But there’s a big difference between the two, Shakhova says: Much of the permafrost on land remains intact because it’s exposed to bitter winter cold, whereas the seafloor permafrost is bathed in cold, yet definitely not freezing, salt water. The annual average temperature of seafloor permafrost is between 12 and 17 degrees warmer than that of nearby land-based permafrost, she notes.

The warmth of the seawater, as well as heat flowing up from within the Earth, has thawed the seafloor permafrost, releasing the methane, the researchers speculate. “We don’t know how long it’s been bubbling like this,” Shakhova adds.

Sonar images show plumes of methane bubbling from the seafloor, indicating that the gas originates in sediments there. Other measurements show that the methane isn’t generated in the water by microbes or brought to the seas by rivers, Shakhova says.

Each year, the researchers estimate, nearly 8 million metric tons of methane make their way to the atmosphere over the East Siberian Arctic Shelf. That’s more than previous estimates for all of the world’s oceans, Shakhova notes.

Siberian seafloor sediments are spewing much more methane than previously thought, but they’re providing only a small fraction of the estimated 440 million tons of that planet-warming gas emitted to the atmosphere each year, Martin Heimann, a biogeochemist at the Max Planck Institute for Biogeochemistry in Jena, Germany, comments in Science. Nevertheless, he notes, release of a sizeable fraction of the carbon trapped in these sediments would lead to warmer atmospheric temperatures, which would in turn cause more methane to be released.

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Scientists have discovered 243-million-year-old fossils of dinosaurs’ closest relatives, pushing back the origin of dinosaurs by at least 10 million years.

The dinosaur-like creature, Asilisaurus kongwe, was about the size of a Labrador retriever and had teeth and jawbones ideally shaped for eating plants, indicating it ate a mostly vegetarian diet.

“This shows that the lineage leading to dinosaurs goes a lot further back in time than we thought. The second thing is that it shows that there’s this real ecological diversity,” said paleontologist Randy Irmis, co-author of the study appearing Mar. 3 in Nature. “No one thought that the closest relatives to dinosaurs were these four-legged, herbivorous animals. We thought they were small carnivores.”

The earliest known dinosaur fossils are around 230 million years old. The new findings indicate that the dinosaurs and the silesaurs, the group that encompasses genus Asilisaurus, diverged more than 243 million years ago. That means dinosaurs must have originated sometime before then.

The team found more than a dozen partial skeletons of Asilisaurus in bare patches in the Tanzanian grasslands. During the Triassic period, the area was warm and lush, with a mixture of woodlands and lower plants like ferns.

“Back then it was a very large river system, maybe something like the Mississippi today,” said lead author and University of Texas at Austin paleontologist Sterling Nesbitt. During that time, Africa, South America, Antarctica, Australia and India were all one giant continent called Gondwana.

Though silesaurs are very closely related to dinosaurs, they lack the open hip-sockets that are universal in dinosaurs. The Asilisaurus was a small, four-legged creatures with a long tail. Their beak-like jaws and leaf-shaped teeth helped the animals eat the soft, fibrous leaves of the primordial palms, ferns and conifers that were prevalent during the Triassic period. That suggests that, while the animal may not have been exclusively vegetarian, a good portion of its diet came from plants, he said.

“In a carnivorous animal, the teeth are pointed, or they are serrated, like a knife to cut meat. In order for this to be efficient, the serration has to be perpendicular to the edge of the tooth so that it functions like a knife,” said paleontologist Gilles Cuny of the the Natural History Museum of Denmark, who was not involved in the study. “In these leaf-shaped teeth, you have some very vague serrations, but they are oriented towards the top of the teeth.”

The findings overturn the previously held idea that the closest relatives to dinosaurs were two-legged, cat-sized predators, Irmis said.

The team also found that similar teeth and jaws evolved separately in the line of dinosaurs that includes apatosaurus, as well as in another line that included triceratops and stegosaurus. All these changes occurred within 10 million years of each other.

“We were really surprised,” Irmis said. “These are three different groups that are really closely related to each other, so you’d expect that maybe their common ancestor had this tooth form. And no, it evolved independently in these three groups.”

That suggests that each of these lineages evolved separately to take advantage of a large, untapped food source, he said.

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Atrazine is receiving lots of attention for turning male frogs into girls, but that’s not all the common herbicide does. It also weakens amphibian immune systems, leaving the fragile creatures vulnerable to disease.

Though less obvious than gender bending, immunosuppression could play just as large a part in the worldwide decline of amphibians, which have porous skin and easily absorb chemicals from rain, groundwater and even water vapor.

“Numerous studies have documented the effects of environmental pollutants on the amphibian immune system. Nearly all of these studies suggest that amphibians are particularly sensitive,” wrote Tyrone Hayes, a University of California, Berkeley biologist, in a paper published in the March 15 Journal of Experimental Biology. “In particular, the widespread herbicide atrazine impairs immune function and increases disease rates.”

Hayes is also an author of a March 1 Proceedings of the National Academy of Sciences study on the developmental changes wrought in male frogs by groundwater atrazine concentrations regularly found in the United States, where 80 million pounds of the herbicide are used every year. The frogs had low levels of sperm and testosterone; some even produced estrogen, developed female reproductive organs and were ultimately impregnated by their former gender mates.

The findings are disturbing, but atrazine’s effects don’t end there. As described in the JEB paper, a large body of scientific literature describes how atrazine drives down white cell counts and turns off immune system-regulating genes. Atrazine also suppresses immune function in snails, which often carry amphibian-infesting parasites, and feeds the algae on which snails live.

It’s a perfect storm of infection: atrazine makes amphibians more vulnerable to disease, and carriers of disease more common.

The best-known amphibian killer, the chytrid fungus, has killed 95 percent of all frogs in Colombia and Panama, and driven 30 species in the Atelopus genus to extinction — and it was only identified in 1993. However, according to Hayes, chytrid is only the most apparent amphibian affliction. Others may go unnoticed because they don’t kill the fragile creatures, but damage their health just enough to prevent populations from sustaining themselves. About 70 percent of amphibian populations around the world are now in decline.

Atrazine, which is scheduled for review by the Environmental Protection Agency after being declared safe by the Bush-era EPA, isn’t the only chemical culprit. Many common pesticides and herbicides have also been linked to amphibian immune malfunction. But as bad as other chemicals may be, atrazine — which can travel up to 600 miles in groundwater — is considered the worst, said Hayes.

“It’s so common, so mobile and persistent, and so active at low levels,” he said. “But there may be chemicals out there just as bad, only we don’t have data on them.”

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Scientists have found a 67 million-year-old fossil of a snake coiled around dinosaur eggs and a hatchling. This is the first evidence of snakes eating dinosaurs.

“It’s a stunning, once-in-a-lifetime find,” said paleontologist Paul Sereno of the University of Chicago, who was not involved in the study. “We’ve caught one of the rarest moments in the fossil record, which is prey and predator, together.”

Geologist Dhanajay Mohabey of the Indian Geological Survey first unearthed the fossil 26 years ago in a rocky, limestone outcropping in the northwestern Indian village of Dholi Dungri. He thought all the bones at the site were those of dinosaur hatchlings.

But in 2001, University of Michigan paleontologist Jeff Wilson, took a second look at the fossils. The team then recognized they had actually found a snake coiled around a broken egg, with a hatchling and two other eggs nearby. The findings appeared Mar. 1 in Public Library of Science Biology.

The newly discovered species of snake, Sanajeh indicus, measures about 11.5 feet long. The hatchlings, part of a group called titanosaurs, measured about a foot and a half long. Titanosaurs were the largest animal to ever walk on land, with adults that could reach up to 100 feet long.

Unlike modern snakes, S. indicus lacked jaw joints that allowed it to open its mouth incredibly wide, so it relied on its large overall body size to prey on the fledgling dinosaurs. Luckily for the snake, the titanosaur hatchlings had soft skeletons that “may have been somewhat collapsible, so you can fold their ribs up a bit and get them in your mouth,” Wilson said.

It’s likely a slow-rising flood or a storm caused adult titanosaurs to flee, abandoning their nests. The snake then slithered into the nest.

Once the babies start hatching, they begin to “pop their leg or arm out. There will be some kind of activity, and the snake is attracted to that. It will coil itself around the egg,” he said. “As soon as it came out of the egg, there’s a snake waiting for it.”

Unluckily for the snake, that moment was frozen in time because a landslide buried the site right then, Wilson said.

The team has found three or four other spots at Dholi Dungri where snake fossils were uncovered near dinosaur eggs, Wilson said.

The findings may offer insight into the origin of snakes. The reptiles first appear in the fossil record around 98 million years ago, Wilson said. But finding such a complete snake fossil is rare, with only a half-dozen well-preserved specimen from this period. “A lot of their early origins are uncertain. More fossils from an early time help put together a picture of snake evolution,” said Wilson.

The fossil find shows some modern animal behavior has very old roots, Sereno said. “Snakes have been at this eating egg-thing for a hundred million years. Before birds fell prey to these things, their ancestors did.”

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Long before human communication evolved into incessant tapping on computer keys, people scratched on eggshells.

sciencenewsDon’t laugh—researchers say a cache of ostrich eggshells engraved with geometric designs demonstrates the existence of a symbolic communication system around 60,000 years ago among African hunter-gatherers.

The unusually large sample of 270 engraved eggshell fragments, mostly excavated over the past several years at Diepkloof Rock Shelter in South Africa, displays two standard design patterns, according to a team led by archaeologist Pierre-Jean Texier of the University of Bordeaux 1 in Talence, France. Each pattern enjoyed its own heyday between approximately 65,000 and 55,000 years ago, the investigators report in a paper to be published this week in the Proceedings of the National Academy of Sciences.

Researchers already knew that the Howiesons Poort culture, which engraved the eggshells, engaged in other symbolic practices, such as engraving designs into pieces of pigment, that were considered to have been crucial advances in human behavioral evolution. But the Diepkloof finds represent the first archaeological sample large enough to demonstrate that Stone Age people created design traditions, at least in their engravings, Texier says.

Evidence of intentionally produced holes in several Diepkloof eggshells indicates that ancient people made what amounted to canteens out of them, a practice that researchers have documented among modern hunter-gatherers in southern Africa.

The engraved patterns probably identified the eggshells as the property of certain groups or communities, Texier proposes.

“The Diepkloof engravings were clearly made for visual display and recognized as such by a large audience comprising members of a community, and probably members of related communities,” comments University of Bordeaux 1 archaeologist Francesco d’Errico, who was not involved in the new study.

D’Errico participated in the recent unearthing of 13 pieces of engraved pigment at South Africa’s Blombos Cave dating to between 100,000 and 75,000 years ago. Along with perforated sea shells and other personal ornaments previously excavated in Africa and the Middle East, these discoveries show that items holding symbolic meaning were made more than 60,000 years ago by both modern humans and Neandertals.

Even more exciting, according to archaeologist Curtis Marean of Arizona State University in Tempe, is the presence of drinking spouts in the South African eggshells. Water containers opened a new world of travel across arid regions for ancient people, he notes.

“The ability to carry and store water is a breakthrough technological advance, and here we have excellent evidence for it very early,” Marean says. “Wow!”

Eggshell fragments from the oldest sediment layers at Diepkloof display a hatched-band motif. These engravings consist of two long, parallel lines intersected by varying numbers of short lines. Some specimens contain one hatched band, while others display remnants of two or three. Engravers always fashioned parallel lines first and then inserted regularly spaced intersecting lines, Texier says.

Eggshells from younger soil layers at Diepkloof contain patterns consisting of deeply engraved, parallel lines that sometimes converge or intersect. One eggshell fragment from these layers exhibits a different pattern—slightly curved horizontal lines that cross a central, vertical line.

Of the many Howiesons Poort sites in southern Africa that have yielded ostrich eggshells, only Diepkloof shows evidence of stylistic engraving traditions, Texier says.

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