Current Carbon Dioxide Emission Higher Than It Was Just Before Ancient Episode of Severe Global Warming

ScienceDaily — The present rate of greenhouse carbon dioxide emissions through fossil fuel burning is higher than that associated with an ancient episode of severe global warming, according to new research. The findings are published online this week by the journal Nature Geoscience.

Scientists believe that the warming may have been initially triggered by an event such as the baking of organic-rich sediments by igneous activity that released the potent greenhouse gas, methane. This initial temperature increase warmed ocean bottom waters which allowed the break down of gas hydrates (clathrates), which are found under deep ocean sediments: this would have greatly amplified the initial warming by releasing even more vast volumes of methane. As the methane diffused from the seawater into the atmosphere it would have been oxidised to form carbon dioxide, another potent and longer-lived greenhouse gas.Around 55.9 million years ago, Earth experienced a period of intense global warming known as the Palaeocene-Eocene Thermal Maximum (PETM), which lasted for around 170,000 years. During its main phase, average annual temperatures rose by around 5°C.

Adam Charles and his PhD supervisor, Dr Ian Harding, both palaeoceanographers at the University of Southampton's School of Ocean and Earth Science (SOES) based at the National Oceanography Centre, Southampton, co-authored the report. Dr Harding said: "The PETM has been seen by many as a natural test bed for understanding modern human-made global warming, despite it not being a perfect analogy. However, the total amount of carbon released during this climatic perturbation and its rate of release have been unclear."

To help fill this gap in knowledge, the researchers measured carbon isotope ratios of marine organic matter preserved in sediments collected in Spitsbergen. The sedimentary section is important because it records the entirety of the PETM, from its initiation to through the recovery period, and as such is the most complete record of the warming event so far known in high northern latitudes.

Based on their carbon isotope measurements and computer simulations of Earth system, the researchers estimated that the rate of carbon emissions during the PETM peaked at between 300 million and 1,700 million metric tonnes per year, which is much slower than the present carbon emission rate.

"Our findings suggest that humankind may be causing atmospheric carbon dioxide to increase at rates never previously seen on Earth, which would suggest that current temperatures will potentially rise much faster than they did during the PETM," concluded Dr Harding.

This research was supported by The Worldwide Universities Network, Pennsylvania State University, and the US National Science Foundation

Higher Density Means World Forests Are Capturing More Carbon

Forests in many regions are becoming larger carbon sinks thanks to higher density, US and European researchers say in a new report. In Europe and North America, increased density significantly raised carbon storage despite little or no expansion of forest area, according to the study, led by Aapo Rautiainen of the University of Helsinki, Finland, and published by the online, open-access journal PLoS One. These photos from the same spot in Finland, taken in 1893 (l) and in 1997 (r) show that while the forest area is the same, the trees are larger in the later photo. (Credit: I.K. Inha (1893) and K.A. Ennola (1997))

ScienceDaily  — Forests in many regions are becoming larger carbon sinks thanks to higher density, U.S. and European researchers say in a new report.

Even in the South American nations studied, more density helped maintain regional carbon levels in the face of deforestation.In Europe and North America, increased density significantly raised carbon storage despite little or no expansion of forest area, according to the study, led by Aapo Rautiainen of the University of Helsinki, Finland, and published in the online, open-access journal PLoS ONE.

The researchers analyzed information from 68 nations, which together account for 72 percent of the world's forested land and 68 percent of reported carbon mass. They conclude that managing forests for timber growth and density offers a way to increase stored carbon, even with little or no expansion of forest area.

"In 2004 emissions and removals of carbon dioxide from land use, land-use change and forestry comprised about one fifth of total emissions. Tempering the fifth by slowing or reversing the loss of carbon in forests would be a worthwhile mitigation. The great role of density means that not only conservation of forest area but also managing denser, healthier forests can mitigate carbon emission," says Rautiainen.

Co-author Paul E. Waggoner, a forestry expert with Connecticut's Agricultural Experiment Station, says remote sensing by satellites of the world's forest area brings access to remote places and a uniform method. "However, to speak of carbon, we must look beyond measurements of area and apply forestry methods traditionally used to measure timber volumes."

"Forests are like cities -- they can grow both by spreading and by becoming denser," says co-author Iddo Wernick of The Rockefeller University's Program for the Human Environment.

The authors say most regions and almost all temperate nations have stopped losing forest and the study's findings constitute a new signal of what co-author Jesse Ausubel of Rockefeller calls "The Great Reversal" under way in global forests after centuries of loss and decline. "Opportunities to absorb carbon and restore the world's forests can come through increasing density or area or both."

To examine how changing forest area and density affect timber volume and carbon, the study team first focused on the United States, where the U.S. Forest Service has conducted a continuing inventory of forest area, timberland area and growing stock since 1953.

They found that while U.S. timberland area grew only 1 percent between 1953 and 2007, the combined national volume of growing stock increased by an impressive 51 percent. National forest density increased substantially.

For an international perspective, the research team examined the 2010 Global Forest Resources Assessment compiled by the UN Food and Agriculture Organization (FAO), which provides consistent figures for the years 1990 to 2010.

The data reveal uncorrelated changes of forest area and density. Countries in Africa and South America, which lost about 10 percent of their forest area over the two decades, lost somewhat less carbon, indicating a small rise in forest density.

In Asia during the second decade of the study period, density rose in 10 of the region's 21 countries. Indonesia's major loss of density and sequestered carbon, however, offset any gain in carbon storage in other Asian nations.

Europe, like the U.S., demonstrated substantial density gains, adding carbon well in excess of the estimated carbon absorbed by the larger forested area.

Says study co-author Pekka Kauppi, of the University of Helsinki, Finland, "With so much bad news available on World Environment Day, we are pleased to report that, of 68 nations studied, forest area is expanding in 45 and density is also increasing in 45. Changing area and density combined had a positive impact on the carbon stock in 51 countries.

Scientists Use Super Microscope to Pinpoint Body’s Immunity 'Switch

ScienceDaily ( — Using the only microscope of its kind in Australia, medical scientists have been able for the first time to see the inner workings of T-cells, the front-line troops that alert our immune system to go on the defensive against germs and other invaders in our bloodstream.

The findings, by researchers at the University of New South Wales (UNSW), are reported in the journalNature Immunology.The discovery overturns prevailing understanding, identifying the exact molecular 'switch' that spurs T-cells into action -- a breakthrough that could lead to treatments for a range of conditions from auto-immune diseases to cancer.

Studying a cell protein important in early immune response, the researchers led by Associate Professor Katharina Gaus from UNSW's Centre for Vascular Research at the Lowy Cancer Research Centre, used Australia's only microscope capable of super-resolution fluorescence microscopy to image the protein molecule-by-molecule to reveal the immunity 'switch'.

The technology is a major breakthrough for science, Dr Gaus said. Currently there are only half a dozen of the 'super' microscopes in use around the world.

"Previously you could see T-cells under a microscope but you couldn't see what their individual molecules were doing," Dr Gaus said.

Using the new microscope the scientists were able to image molecules as small as 10 nanometres. Dr Gaus said that what the team found overturns the existing understanding of T-cell activation.

"Previously it was thought that T-cell signalling was initiated at the cell surface in molecular clusters that formed around the activated receptor.

"In fact, what happens is that small membrane-enclosed sacks called vesicles inside the cell travel to the receptor, pick up the signal and then leave again," she said.

Dr Gaus said the discovery explained how the immune response could occur so quickly.

"There is this rolling amplification. The signalling station is like a docking port or an airport with vesicles like planes landing and taking off. The process allows a few receptors to activate a cell and then trigger the entire immune response," she said.

PhD candidate David Williamson, whose research formed the basis of the paper, said the discovery showed what could be achieved with the new generation of super-resolution fluorescence microscopes.

"In conventional microscopy, all the target molecules are lit up at once and individual molecules become lost amongst their neighbours -- it's like trying to follow a conversation in a crowd where everyone is talking at once.

"With our microscope we can make the target molecules light up one at a time and precisely determine their location while their neighbours remain dark. This 'role call' of all the target molecules means we can then build a 'super resolution' image of the sample," he said.

The next step was to pinpoint other key proteins to get a complete picture of T-cell activity and to extend the microscope to capture 3-D images with the same unprecedented resolution.

"Being able to see the behaviour and function of individual molecules in a live cell is the equivalent of seeing atoms for the first time. It could change the whole concept of molecular and cell biology," Mr Williamson said.

Other research team members were physicist Dr Dylan Owen, cell biologists Dr Jérémie Rossy and Dr Astrid Magenau, from the Centre for Vascular Research, and Professor Justin Gooding and Matthias Wehrmann, from UNSW's School of Chemistry and the Australian Centre for Nanomedicine. The research was supported by funding from the National Health and Medical Research Council, Australian Research Council and Human Frontier Science Program

First-of-Its-Kind Fluorescence Map Offers a New View of the World's Land Plants

A first-of-a-kind global map of land plant fluorescence shows stronger photosynthetic activity in the Northern Hemisphere in July when light and temperature conditions were most conducive to plant growth, and the reverse in December. The maps are based on data from a spectrometer aboard the Japanese satellite GOSAT. (Credit: NASA's Earth Observatory)

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ScienceDaily  — Scientists from NASA's Goddard Space Flight Center in Greenbelt, Md., have produced groundbreaking global maps of land plant fluorescence, a difficult-to-detect reddish glow that leaves emit as a byproduct of photosynthesis. While researchers have previously mapped how ocean-dwelling phytoplankton fluoresce, the new maps are the first to focus on land vegetation and to cover the entire globe.

However, there is a lag between what happens on the ground and what satellites can detect. It can take days -- even weeks -- before changes in greenness are apparent to satellites.To date, most satellite-derived information related to the health of vegetation has come from "greenness" indicators based on reflected rather than fluorescent light. Greenness typically decreases in the wake of droughts, frosts, or other events that limit photosynthesis and cause green leaves to die and change color.

Chlorophyll fluorescence offers a more direct window into the inner workings of the photosynthetic machinery of plants from space. "With chlorophyll fluorescence, we should be able to tell immediately if plants are under environmental stress -- before outward signs of browning or yellowing of leaves become visible," said Elizabeth Middleton, a NASA Goddard-based biologist and a member of the team that created the maps.

The new maps, based on data collected in 2009 from a spectrometer aboard a Japanese satellite called the Greenhouse Gases Observing Satellite (GOSAT), show sharp contrasts in plant fluorescence between seasons. In the Northern Hemisphere, for example, fluorescence production peaked during July, while in the Southern Hemisphere it did in December.

The new findings help confirm previous lab and field experiments that suggest chlorophyll fluorescence should taper off in the fall as the abundance of green foliage declines and stress increases as a result of lower temperatures and less favorable light conditions.

While additional research is required to sort out the subtleties of the fluorescence signal, the new maps are significant as they demonstrate the feasibility of measuring fluorescence from space.

In the future, the Goddard team expects that fluorescence measurements will complement existing measures of "greenness" in a variety of ways. They could help farmers respond to extreme weather or make it easier for aid workers to detect and respond to famines. Fluorescence could also lead to breakthroughs in scientists' understanding of how carbon cycles through ecosystems -- -- one of the key areas of uncertainty in climate science.

"What's exciting about this is that we've proven the concept," said Joanna Joiner, the deputy project scientist for NASA's Aura mission and the leader of the Goddard team that created the maps. "The specific applications will come later."

Glowing Plants?

The same mechanism that makes plants fluoresce causes a range of everyday objects -- ground-up plant leaves, white shirts, jellyfish, and even blood and urine -- to glow intensely under black light.

However, plants fluoresce in specific parts of the blue, green, red, and far-red spectrum. Chlorophyll fluorescence from green foliage, for example, is produced at the red and far-red wavelengths.

"In plants, fluorescence is not something that you can see with your naked eye because background light overwhelms it," explained Joiner, the lead author of the paper. When sunlight strikes a leaf, disc-like green structures called chloroplasts absorb most of the light and convert it into carbohydrates through photosynthesis.

Chloroplasts re-emit about two percent of incoming light at longer, redder wavelengths. This re-emitted light -- fluorescent light -- is what the Goddard scientists measured to create their map. Fluorescence is different than bioluminescence, the chemically-driven mechanism lightning bugs and many marine species use to glow without exposure to light.

For decades, scientists have measured fluorescence in plants by exposing leaves to laser beams that, like black light, make fluorescence more apparent. Such experiments have revealed much about how certain types of plants fluoresce, but researchers have not been able to use lasers to measure the phenomenon across broad swaths of Earth's surface.

To create their global fluorescence map, Joiner and her colleagues used a different technique. They analyzed an unusually dark section of the infrared portion of the solar spectrum embedded within a feature called a "Fraunhofer line." There is little background light at the line they focused on -- at about 770 nanometers -- which made it possible to distinguish the faint fluorescence signal.

The Future of Fluorescence

The new findings have implications for both current and upcoming satellite missions. In the near term, awareness of the fluorescence signal should help atmospheric scientists refine measurements of carbon dioxide and methane from the GOSAT mission.

The creation of the maps also bolsters the argument that an experimental mission being developed by the European Space Agency (ESA) -- the Fluorescence Explorer (FLEX) mission -- would make significant breakthroughs. The ESA is currently in the midst of feasibility studies and has not yet set a launch date for FLEX.

The findings also suggest that NASA's Orbiting Carbon Observatory-2 (OCO-2), a mission that is designed to measure carbon dioxide levels much like GOSAT, should be able to make useful fluorescence measurements on a global scale. OCO 2 will launch no earlier than February of 2013 from Vandenberg Air Force Base in California.

The maps, published online in the journal Biogeosciences, represent just a first attempt to detect terrestrial fluorescence on a broad scale and will be enhanced and expanded over time, the scientists involved in the project emphasized.

More work needs to be done, for example, to understand how plant fluorescence varies depending on light conditions. In strong afternoon light, the conditions that GOSAT made its observations, unstressed plants produce a stronger fluorescence signal than stressed plants. However, complicating matters, the reverse is true in the morning or evening when light is less intense.

To disentangle the two opposing effects, the Goddard-based group plans to continue refining the mathematical methods they used to calculate fluorescence. Meanwhile, groups of scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif. -- as well as Japanese and European research groups -- are in the process of honing similar fluorescence-monitoring methods.

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Astrophysicists Use X-Ray Fingerprints to Study Eating Habits of Giant Black Holes

Georgia Tech astrophysicists have provided an important test of a long-standing theory that describes the extreme physics occurring when matter spirals into massive objects known as black holes. Here, David Ballantyne, Jon McDuffie and John Rusin pose with a NASA illustration of a black hole. (Credit: Georgia Tech Photo: Gary Meek)

ScienceDaily  — By studying the X-rays emitted when superheated gases plunge into distant and massive black holes, astrophysicists at the Georgia Institute of Technology have provided an important test of a long-standing theory that describes the extreme physics occurring when matter spirals into these massive objects.

Matter falling into black holes emits tremendous amounts of energy which can escape as visible light, ultraviolet light and X-rays. This energy can also drive outflows of gas and dust far from the black hole, affecting the growth and evolution of galaxies containing the black holes. Understanding the complex processes that occur in these active galactic nuclei is vital to theories describing the formation of galaxies such as the Milky Way, and is therefore the subject of intense research.

Though light cannot escape from black holes themselves, black holes with accretion disks -- which are swirling clouds of matter about to enter the black hole -- are among the most luminous objects in galaxies. By studying how the radiation and accretion disk interact, astrophysicists can learn much about the extreme gravitational fields, magnetic forces and radiation processes close to these black holes.

"We reviewed data collected from space telescopes over the past few years and found that the more rapidly a black hole was gobbling up material, the more highly ionized the accretion disk was," said David Ballantyne, an assistant professor in Georgia Tech's School of Physics. "The simple theory of accretion disks predicts this, but the relationship we saw between the ionization and rate of accretion was different from what the theory predicted."

The large difference between the observed and theoretical relationships -- a linear dependence on the rate of accretion as opposed to a cubic dependence -- is not surprising for a phenomenon that can't exactly be tested under controlled laboratory conditions. In a paper published online June 3 in The Astrophysical Journal, Ballantyne describes the research and speculates about possible reasons for the difference between observations and theory. The research, which will appear in the Journal's June 20 issue, was supported in part by the National Science Foundation (NSF).

"As in many areas of science, especially astronomy, we end up needing more data -- many more high-quality observations to better define this relationship," he added.

Astrophysicists don't have a detailed understanding of how the accretion process works, why black holes grow at different rates -- or what makes them stop growing. These questions are important because the growth of active galactic nuclei -- the black holes and their surrounding accretion disks -- has broader effects on the galaxies of which they are part.

"The rapid accretion phase releases a lot of energy, not only in radiation, but also in outflows that drive gas out of a galaxy, which can shut off star formation and hold back the growth of the galaxy," said Ballantyne, a scientist in Georgia Tech's Center for Relativistic Astrophysics. "We could potentially learn something fundamental about the flow of energy through the accretion disk very close to the black hole. We could learn about the viscosity of this matter and how efficiently radiation transport takes place. These are very important questions in astrophysics."

X-rays are believed to originate from innermost portion of active galactic nuclei. As they pass through matter on its way into the black hole, the X-rays are altered by the materials in ways that astrophysicists can measure. In their study, Ballantyne and his collaborators were interested in studying the ionization state of the matter -- which is related to the illumination -- and were able to do so by analyzing the "fingerprint" the ionization left on the X-rays.

"From laboratory work, we understand the physics of how gas interacts with X-ray radiation because that's basically an atomic physics problem," he explained. "We can model what these fingerprints might look like on the X-rays, and compare that to the actual data to help us understand what's going on."

Because of their high energy and short wavelength, X-rays pass through many materials, such as human bodies, with little attenuation. This makes them ideal for examining processes in active galactic nuclei. Longer wavelengths, such as ultraviolet and visible light, are absorbed by intergalactic dust, or are difficult to distinguish from light originating in stars. However, X-rays do get absorbed by dense objects, such as bones -- and crucially for this study -- accretion disks.

Ballantyne and his collaborators Jon McDuffie and John Rusin studied ten X-ray observations reported by other scientists from eight different active galactic nuclei. The observations were made using such space telescopes as Chandra and XMM.

To be useful, they used only measurements of X-ray emissions from the innermost and hottest portion of the accretion disk, and only where the mass of the black holes -- which range from a million to a billion times the size of our sun -- had high quality estimates.

In pursuing the study, Ballantyne hopes to maintain the involvement of Rusin, a student from South Cobb High School in Marietta, near Atlanta. Rusin became involved when he contacted Georgia Tech to inquire about astrophysics projects.

"He helped us with data acquisition and was a really big help," said Ballantyne. "I treated him just like an undergraduate student. I'm pleased to know that he has decided to attend Georgia Tech."

The next step in the research will be to gather additional information from other studies of active galactic nuclei to see if the linear relationship Ballantyne's group measured holds up. The work may also lead to other techniques for learning about black holes and the accretion process.

"Black holes themselves are very simple, but what goes on around them can be very complex," Ballantyne said. "There is still a lot to be learned about how black holes get fueled, and how some accrete slowly while others grow rapidly. The astrophysics of black holes is actually very important in determining what our universe looks like."

Yo-Yo Dieting Vs. Obesity? Dieters May Be Healthier, Live Longer, Mouse Study Suggests

A new study suggests that yo-yo dieters may be healthier and live longer than those who stay obese. (Credit: © Karen Roach / Fotolia)

ScienceDaily— Yo-yo dieters may be healthier and live longer than those who stay obese, a new Ohio University study in mice suggests.

Some experts argue that constantly shedding and regaining pounds can be harmful to health. The new research, presented at the annual meeting of the Endocrine Society in Boston, suggests, however, that yo-yo dieting is preferable to remaining obese and not dieting at all.Mice that switched between a high-fat and low-fat diet every four weeks during their approximate two-year lifespan lived about 25 percent longer and had better blood glucose levels than obese animals that ate a high-fat diet. The yo-yo dieters also lived about as long as a control group of mice steadily fed a low-fat diet.

"If the conventional wisdom is true, it would discourage a lot of overweight people from losing weight," said study lead author Edward List, a scientist at Ohio University's Edison Biotechnology Institute. "The new research shows that the simple act of gaining and losing weight does not seem detrimental to lifespan."

About 34 percent of American adults are considered to be obese; an additional 34 percent are classified as overweight, according to the Centers for Disease Control and Prevention. Although millions of Americans diet each year, research has shown that few people maintain long-term weight loss.

In the first study on yo-yo dieting of its kind, List and colleagues followed 30 mice on one of three dietary regimens over the course of a little over two years, the typical lifespan of this particular strain of laboratory mouse. The animals on the high-fat diet ate more, weighed more and had higher levels of body fat and fasting blood glucose. They also become glucose intolerant, or pre-diabetic, said List, whose research is supported by the National Institutes of Health, AMVETS and Ohio University.

The health profile of the mice on the yo-yo diet declined during their high-fat food phases, but their weight and blood glucose levels returned to normal levels during their low-fat diet stages. Lifespan -- the "gold standard" for lifelong health status -- was 2.04 years for the yo-yo dieting mice, compared to 1.5 years for the obese mice. The control group lived, on average, for 2.09 years.

Although replicating the research in humans is ideal, List said, it would be challenging to pursue a long-term controlled diet study. Various factors, including illness, can impact weight cycling. Mice can serve as a good model for obesity research, he noted, as they allow researchers to follow the effects of diet choices on lifespan over a relatively short time period.

"The study adds to our understanding of the benefit of losing weight," he said. "I would hope that this encourages people to not give up."

List plans to expand the study to a larger population of mice. He'll also further examine preliminary findings that suggest that the yo-yo dieting animals experienced a reduction in cytokine levels. High levels of cytokine are linked to increased inflammation, which is associated with diseases such as diabetes, heart disease and cancer.

Co-authors of the study are former Ohio University student Jacob Wright-Piekarski, now a medical student with St. Louis University, and Edison Biotechnology Institute scientists Darlene Berryman, an associate professor in the College of Health Sciences and Professions, and John Kopchick, Goll-Ohio Eminent Scholar of molecular biology in the College of Osteopathic Medicine

Novel Geothermal Technology Packs a One-Two Punch Against Climate Change

Martin Saar, an Earth sciences faculty member, and graduate student Jimmy Randolph have devised an ingenious "two-for-one" strategy to simultaneously produce renewable energy and reduce the presence of harmful carbon dioxide in the atmosphere. (Credit: Image courtesy of University of Minnesota)

ScienceDaily  — Two University of Minnesota Department of Earth Sciences researchers have developed an innovative approach to tapping heat beneath Earth's surface. The method is expected to not only produce renewable electricity far more efficiently than conventional geothermal systems, but also help reduce atmospheric carbon dioxide (CO₂) -- dealing a one-two punch against climate change.

The approach, termed CO₂-plume geothermal system, or CPG, was developed by Earth sciences faculty member Martin Saar and graduate student Jimmy Randolph in the university's College of Science and Engineering. The research was published in the most recent issue ofGeophysical Research Letters. The researchers have applied for a patent and plan to form a start-up company to commercialize the new technology.

Established methods for transforming Earth's heat into electricity involve extracting hot water from rock formations several hundred feet from Earth's surface at the few natural hot spots around the world, then using the hot water to turn power-producing turbines. The university's novel system was born in a flash of insight on a northern Minnesota road trip and jump-started with $600,000 in funding from the U of M Institute on the Environment's Initiative for Renewable Energy and the Environment (IREE). The CPG system uses high-pressure CO₂instead of water as the underground heat-carrying fluid.

CPG provides a number of advantages over other geothermal systems, Randolph said. First, CO₂ travels more easily than water through porous rock, so it can extract heat more readily. As a result, CPG can be used in regions where conventional geothermal electricity production would not make sense from a technical or economic standpoint.

"This is probably viable in areas you couldn't even think about doing regular geothermal for electricity production," Randolph said. "In areas where you could, it's perhaps twice as efficient."

CPG also offers the benefit of preventing CO₂ from reaching the atmosphere by sequestering it deep underground, where it cannot contribute to climate change. In addition, because pure CO₂ is less likely than water to dissolve the material around it, CPG reduces the risk of a geothermal system not being able to operate for long times due to "short-circuiting" or plugging the flow of fluid through the hot rocks. Moreover, the technology could be used in parallel to boost fossil fuel production by pushing natural gas or oil from partially depleted reservoirs as CO₂ is injected.

Saar and Randolph first hit on the idea behind CPG in the fall of 2008 while driving to northern Minnesota together to conduct unrelated field research. The two had been conducting research on geothermal energy capture and separately on geologic CO₂sequestration.

"We connected the dots and said, 'Wait a minute -- what are the consequences if you use geothermally heated CO₂?'" recalled Saar. "We had a hunch in the car that there should be lots of advantages to doing that."

After batting the idea around a bit, the pair applied for and received a grant from the Initiative for Renewable Energy and the Environment, which disburses funds from Xcel Energy's Renewable Development Fund to help launch potentially transformative projects in emerging fields of energy and the environment. The IREE grant paid for preliminary computer modeling and allowed Saar and Randolph to bring on board energy policy, applied economics and mechanical engineering experts from the University of Minnesota as well as modeling experts from Lawrence Berkeley National Laboratory. It also helped leverage a $1.5 million grant from the U.S. Department of Energy to explore subsurface chemical interactions involved in the process.

"The IREE grant was really critical," Saar said. "This is the kind of project that requires a high-risk investment. I think it's fair to say that there's a good chance that it wouldn't have gone anywhere without IREE support in the early days."

Saar and Randolph have recently applied for additional DOE funding to move CPG forward to the pilot phase.

"Part of the beauty of this is that it combines a lot of ideas but the ideas are essentially technically proven, so we don't need a lot of new technology developed," Randolph said.

"It's combining proven technology in a new way," Saar said. "It's one of those things where you know how the individual components work. The question is, how will they perform together in this new way? The simulation results suggest it's going to be very favorable."

Apple Ingredient Keeps Muscles Strong: Component of Apple Peels Found to Help Prevent Muscle Weakening in Mice

Researchers have identified a component of apple peels that helps prevent muscle weakening in mice. (Credit: © Anyka / Fotolia)

ScienceDaily  — In search of a way to prevent the muscle wasting that comes with illness and aging, researchers have landed a natural compound that might just do the trick. The findings reported in the June issue of Cell Metabolism, a Cell Press publication, identify a component of apple peels as a promising new drug candidate for the widespread and debilitating condition that affects nearly everyone at one time or another.

Motivated by the desire to change that, Adams' team first looked at what happens to gene activity in muscles under conditions that promote weakening. Those studies turned up 63 genes that change in response to fasting in both people and mice and another 29 that shift their expression in the muscles of both people who are fasting and those with spinal cord injury. Comparison of those gene expression signatures to the signatures of cells treated with more than 1300 bioactive small molecules led them to ursolic acid as a compound with effects that might counteract those of atrophy."Muscle wasting is a frequent companion of illness and aging," said Christopher Adams of The University of Iowa, Iowa City. "It prolongs hospitalization, delays recoveries and in some cases prevents people from going back home. It isn't well understood and there is no medicine for it."

"Ursolic acid is an interesting natural compound," Adams said. "It's part of a normal diet as a component of apple peels. They always say that an apple a day keeps the doctor away…"

The researchers next gave ursolic acid to fasted mice. Those experiments showed that ursolic acid could protect against muscle weakening as predicted. When ursolic acid was added to the food of normal mice for a period of weeks, their muscles grew. Those effects were traced back to enhanced insulin signaling in muscle and to corrections in the gene signatures linked to atrophy.

Animals given ursolic acid also became leaner and had lower blood levels of glucose, cholesterol and triglycerides. The findings therefore suggest that ursolic acid may be responsible for some of the overall benefits of healthy eating.

"We know if you eat a balanced diet like mom told us to eat you get this material," Adams said. "People who eat junk food don't get this."

It is not yet clear whether the findings in mice will translate to human patients, Adams says, but his goal now is to "figure out if this can help people." If so, they don't yet know whether ursolic acid at levels that might be consumed as part of a normal diet might or might not be enough

Native Ants Use Chemical Weapons to Turn Back Invading Argentine Ants

A native winter ant in the act of trying to apply a drop of the whitish toxin it can secrete from its abdomen onto an Argentine ant. The angle of the photograph distorts the relative sizes of the two species, which are roughly the same size. (Credit: Trevor Sorrells)

ScienceDaily  — Stanford sophomores studying ants in a summer course discovered that the local ants were using poison to kill invading Argentine ants. The discovery provides new insight into the war between the local "winter ants" and the South American invaders who have shown up everywhere from California to South Africa.

The winter ants -- named for their unusual ability to function in cold weather, rather than grind to a halt like most insects -- manufacture a poison in a gland in their abdomen that they dispense when under extreme duress. One tiny drop applied to an Argentine ant is enough to put an end to it. In laboratory testing, the poison had a 79 percent kill rate.Argentine ants are taking over the world -- or at least the nice temperate parts. They've spread into Mediterranean and subtropical climates across the globe in sugar shipments from Argentina, and no native ant species has been known to withstand their onslaught -- until now. A group of Stanford University undergraduate students working on a class project have discovered that a native species, the plucky winter ant, has been using chemical warfare to combat the Argentine tide.

"This is the first well-documented case where a native species is successfully resisting the Argentine ant," said Deborah M. Gordon, a biology professor at Stanford who specializes in studying ants and taught the three-week summer class in which the students first saw the winter ants wielding their poison.

"I did not believe it at first," she said. "This is a group of ants that does not have a sting and you don't see them acting aggressively, but the students were able to show very clearly not just that the winter ants are using poison, but when they use it, how they use it and what the impact is."

Gordon and her students presented their findings in a paper published earlier this year in PLoS ONE, a journal published by the Public Library of Science.

Argentine ant invasion

The Argentine ants are happy anyplace that has cool, rainy winters and hot, dry summers. They have conquered the entire coastline around the Mediterranean Sea, parts of South Africa, Hawaii, Japan and Australia, as well as the full length of the California coastline.

"If you live in a Mediterranean climate, the Argentine ant is the ant in your kitchen," Gordon said. "These ants, wherever they become established, wipe out all the native ants."

Leah Kuritzky marks the trail of some of the winter ants she and her fellow student researchers studied on the Stanford campus.

The extermination of native ants sets off a ripple effect through an ecosystem. Some native ant species that eat seeds have coevolved with certain native grasses and other plants to become a crucial part of the plant's propagation by carrying the seeds to new areas. Without the native ant species to spread their seeds, the grasses can't flourish. Any significant impact on the plants would also likely affect creatures that feed on or nest in the plants.

Argentine ants have been declared agricultural pests in California because of the damage they do to citrus crops. The invaders are partial to areas where the ground has been disturbed, such as plowed fields and construction sites. They also spread through plants sold by nurseries.

The invaders are agriculturalists after a fashion themselves, tending "herds" of aphids and other scale insects that attach to plants and suck out the sugary sap. The ants, in turn, feed on the sugar-rich liquid that the aphids excrete, "quaintly called honeydew," Gordon said. By protecting the aphids from predators, the Argentines enable the insects to spread.

That yummy honeydew is what brings the Argentine invaders and the winter ants into conflict, as winter ants also tend aphids.

The Stanford students began observing the native ants as part of a 2008 short summer class for sophomores called Ecology of Invasions, taught by Gordon. At a variety of locations on the Stanford campus, they started out simply observing and recording ant behavior while visiting each site at the same time every day.

"We were looking at the nest openings of the winter ants and one day it was just winter ants going about their business foraging for food and making trails -- just typical ant behavior," said Leah Kuritzky, a student in the class and one of the coauthors of the PLoS ONE paper.

An ant 'massacre'

"The next day we came back and the ground was littered with Argentine ants. There were dead ants all around and there was a lot of fighting around the nest entrances."

In earlier observations, the students had noticed the winter ants occasionally secreting a whitish fluid from their abdomens and, by prodding a few with a paperclip, had figured out that the ants tended to secrete when hassled.

"They would curl their abdomens around and deposit the white secretion on the paper clip used to prod them," said Trevor Sorrells, then a junior who was a teaching assistant for the class.

Watching the combat, the students saw the winter ants use their lethal secretions against the invaders. Intrigued, the group decided to continue the research after the class ended.

Kuritzky did a chemical analysis of the secretion, using gas chromatography and mass spectrometry. She determined that part of the secretion consisted of a type of hydrocarbon, which many social insects use to carry a colony-specific odor that helps them identify friend from foe. But what substance gives the secretion is lethal punch still has to be determined.

"Whatever it is, it is clearly very toxic," Gordon said.

To assess the lethality of the secretion -- and how freely the winter ants wielded it -- Sorrells and the other students ran a series of "trials by combat" in palm-sized shallow glass petri dishes in the lab.

He organized some group rumbles with 20 ants per dish, varying the ratio of winter ants to Argentine ants to see if that had an effect. He also ran some one-on-one gladiatorial combat in a one-centimeter square "ring."

"It turns out the winter ants use the secretion only when they are really overwhelmed, so it is probably energetically very expensive for the winter ant to manufacture and use this stuff," Gordon said.

In the great outdoors, without petri dish arenas in which to settle their disputes, the winter ants tend to use their secretion either when vastly outnumbered or in the immediate defense of queen and colony.

Gordon has been conducting ant population studies in Stanford's Jasper Ridge Biological Preserve for 18 years, during which she has seen territory change hands as the invaders pushed into the preserve and displaced the winter ants. But several years ago, the winter ants began gaining the upper hand.

"It looks like the Argentine ants are getting pushed back tree by tree," Gordon said. The winter ants are showing up in trees where the Argentine ants had been.

"It seems the winter ants let the Argentine ants find the aphids and then they take over. Over time, the winter ants may be starving the Argentine ants out," she said.

The recent shift in the balance of power may be in part a result of cooler weather, which favors the winter ants, and low rainfall, which inhibits the Argentine ants, Gordon suggested.

So in a natural habitat, without warm buildings in which the Argentine ants can gather around the kitchen hearth, the winter ants can hold the invaders back. But continued development, which creates the disturbed ground and toasty homes that the Argentine ants favor, may well trump the winter ants' chemical weapon in the long run. Already, Gordon said, the Argentine ants in California far outnumber the native winter ants.

Gordon is a professor in the Department of Biology and a senior fellow at Stanford's Woods Institute for the Environment.

The other Stanford undergraduates (past and present) who are coauthors of the PLoS ONE paper are Peter Kauhanen, Jimmy Chen, Cheri Dijamco and Kimberly Basurto.Shelby Sturgis, a graduate student in biology, is also a coauthor, as is Katherine Fitzgerald,who was a graduate student at the time of the study.

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Air Quality Worsened by Paved Surfaces: Widespread Urban Development Alters Weather Patterns

ScienceDaily  — New research focusing on the Houston area suggests that widespread urban development alters weather patterns in a way that can make it easier for pollutants to accumulate during warm summer weather instead of being blown out to sea.

The international study, led by the National Center for Atmospheric Research (NCAR), could have implications for the air quality of fast-growing coastal cities in the United States and other midlatitude regions overseas. The reason: the proliferation of strip malls, subdivisions, and other paved areas may interfere with breezes needed to clear away smog and other pollution.

The research team combined extensive atmospheric measurements with computer simulations to examine the impact of pavement on breezes in Houston. They found that, because pavement soaks up heat and keeps land areas relatively warm overnight, the contrast between land and sea temperatures is reduced during the summer. This in turn causes a reduction in nighttime winds.

In addition, built structures interfere with local winds and contribute to relatively stagnant afternoon weather conditions.

"The developed area of Houston has a major impact on local air pollution," says NCAR scientist Fei Chen, lead author of the new study. "If the city continues to expand, it's going to make the winds even weaker in the summertime, and that will make air pollution much worse."

While cautioning that more work is needed to better understand the impact of urban development on wind patterns, Chen says the research can eventually help forecasters improve projections of major pollution events. Policymakers might also consider new approaches to development as cities work to clean up unhealthy air.

The article will be published this month in the Journal of Geophysical Research-Atmospheres, a publication of the American Geophysical Union. The research was funded by the U.S. Air Force Weather Agency, the U.S. Defense Threat Reduction Agency, and the National Science Foundation, NCAR's sponsor. In addition to NCAR, the authors are affiliated with the China Meteorological Administration, the U.S. National Oceanic and Atmospheric Administration, and the University of Tsukuba in Japan. The research built on a number of previous studies into the influence of urban areas on air pollution.

Cleansing the air with more parks and lakes?

Houston, known for its mix of petrochemical facilities, sprawling suburbs, and traffic jams that stretch for miles, has some of the highest levels of ground-level ozone and other air pollutants in the United States.

State and federal officials have long worked to regulate emissions from factories and motor vehicles in an effort to improve air quality.

The new study suggests that focusing on the city's development patterns and adding to its already extensive park system could provide air quality benefits as well.

"If you made the city greener and created lakes and ponds, then you probably would have less air pollution even if emissions stayed the same," Chen explains. "The nighttime temperatures over the city would be lower and winds would become stronger, blowing the pollution out to the Gulf of Mexico."

Chen adds that more research is needed to determine whether paved areas are having a similar effect in other cities in the midlatitudes, where sea breezes are strongest. Coastal cities from Los Angeles to Shanghai are striving to reduce air pollution levels. However, because each city's topography and climatology is different, it remains uncertain whether expanses of pavement are significantly affecting wind patterns elsewhere.

Nine days of pollution

For the Houston study, Chen and his colleagues focused on the onset of a nine-day period of unusually hot weather, stagnant winds, and high pollution in the Houston-Galveston area that began on August 30, 2000. They chose that date partly because they could draw on extensive atmospheric measurements taken during that summer by researchers participating in a field project known as the Texas Air Quality Study 2000. That campaign was conducted by the National Oceanic and Atmospheric Administration, the U.S. Department of Energy, universities, and the Texas Natural Resource Conservation Commission.

In addition to the real-world measurements, the study team created a series of computer simulations with a cutting-edge software tool, NCAR's Advanced Weather Research and Forecasting model.

Fei and his colleagues focused on wind patterns, which are driven by temperature contrasts between land and sea. If Houston were covered with cropland instead of pavement, as in one of the computer simulations, inland air would heat up more than marine air during summer days and cause a sea breeze to blow onshore in the afternoon. Conversely, as the inland air became cooler than marine air overnight, a land breeze would blow offshore -- potentially blowing away pollution.

In contrast, the actual paved surfaces of Houston absorb more heat during the day and are warmer overnight. This results in stagnation for three reasons:

• At night, the city's temperatures are similar to those offshore. The lack of a sharp temperature gradient has the effect of reducing winds.
• During the day, the hot paved urban areas tend to draw in air from offshore. However, this air is offset by prevailing wind patterns that blow toward the water, resulting in relatively little net movement in the atmosphere over the city.
• Buildings and other structures break up local winds far more than does the relatively smooth surface of croplands or a natural surface like grasslands. This tends to further reduce breezes.

"The very existence of the Houston area favors stagnation," the article states.

The study also found that drought conditions can worsen air pollution. This is because dry soil tends to heat up more quickly than wet soil during the day. It releases more of that heat overnight, reducing the temperature contrast between land and water and thereby reducing nighttime breezes.

By comparing observations taken in 2000 with computer simulations of Houston-area winds and temperatures, the researchers were able to confirm that the Advanced Weather Research and Forecasting model was accurately capturing local meteorological conditions