Wednesday, July 22, 2009

NEW PRINCETON METHOD MAY HELP ALLOCATE CARBON EMISSIONS RESPONSIBILITY AMONG NATIONS

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Just months before world leaders are scheduled to meet to devise a new international treaty on climate change, a research team led by Princeton University scientists has developed a new way of dividing responsibility for carbon emissions among countries.

The approach is so fair, according to its creators, that they are hoping it will win the support of both developed and developing nations, whose leaders have been at odds for years over perceived inequalities in previous proposals.

The method is outlined in a paper, titled "Sharing Global CO2 Emissions Among 1 Billion High Emitters," published online in this week's Proceedings of the National Academy of Sciences. According to the authors, the approach uses a new fairness principle based on the "common but differentiated responsibilities" of individuals, rather than nations.

"Our proposal moves beyond per capita considerations to identify the world's high-emitting individuals, who are present in all countries," the team says in the introduction. The authors include Stephen Pacala, the Frederick D. Petrie Professor of Ecology and Evolutionary Biology, and Robert Socolow, a professor of mechanical and aerospace engineering. Pacala and Socolow's concept of "stabilization wedges," a strategy that proposed concrete ways to prevent global emissions of greenhouse gases from rising for the next five decades, was featured in "An Inconvenient Truth," former Vice President Al Gore's 2006 film about climate change. The concept has given the climate change policy community a common unit for discussing how to reduce emissions and for allowing a comparison of different carbon-cutting strategies.

The lead authors on the paper are physicist Shoibal Chakravarty and economist Massimo Tavoni, both research scholars at the Princeton Environmental Institute, which is the University's interdisciplinary center for environmental research, education and outreach.

"The team worked together to formulate a novel approach to a long-standing and intractable problem," said Pacala, who is also director of the institute.

The proposal would use individual emissions as the best, fairest way of calculating a nation's responsibility to curb its output of carbon dioxide, the authors said. The methodology does not mean that individuals would be singled out, only that these calculations would form the basis of a more equitable formula. Some present strategies that employ averages of energy use in a country are widely regarded as unfair, the authors say, because such efforts mask the emissions of wealthy, high polluters.

"Most of the world's emissions come disproportionately from the wealthy citizens of the world, irrespective of their nationality," Chakravarty said, noting that many emissions come from lifestyles that involve airplane flights, car use and the heating and cooling of large homes. "We estimate that in 2008, half of the world's emissions came from just 700 million people."

In the new scheme, emission reduction targets for each country are calculated in a multi-step fashion. The researchers used a strong correlation between income and emissions to estimate the emissions of individuals in every country. Next, they combined these factors to see how individual emissions are distributed globally.

Looking forward to 2030, the researchers estimated first individual emissions and then a global emission total at that future time based on projections of income, population and energy use. They imagined the world's leaders deciding now that the projected global emission total for 2030 is dangerously high, choosing a lower global target and seeking a process by which the work of achieving this new global target could be divided among the world's nations.

The proposal "provides a significant starting point for breaking through the current impasse over the respective mitigation responsibilities of developed and developing countries," said Robyn Eckersley, a professor in the School of Social and Political Sciences at the University of Melbourne in Australia who specializes in environmental politics and political theory.

The researchers believe their new framework is useful in that it establishes a uniform "cap" on emissions that individuals should not exceed. If, for example, world governments agreed to curtail emissions so that carbon levels in 2030 are approximately at present levels, then, according to the researchers' calculations, the necessary reductions in global emissions could be achieved if no individual's emissions could exceed about 11 tons of carbon dioxide a year. By counting the emissions of all the individuals who are projected to exceed that level, the world leaders could provide target emissions reductions for every country. For this specific example, there will be about 1 billion such "high emitters" in 2030 out of 8.1 billion people.

At present, the world average for tons of carbon dioxide emitted a year per individual is about five. Each European produces about 10 tons a year, with each American producing twice that amount.

"These numbers strengthen our conviction that industrialized countries will have to take the lead in reducing their emissions, but that the fight to prevent dangerous climate change can only be won if all countries act together," said Ottmar Edenhofer, the chair of Economics of Climate Change at the Technical University Berlin and co-chair of Working Group III of the Intergovernmental Panel on Climate Change (IPCC). The IPCC was created by the U.N. General Assembly in 1988 to provide objective policy advice in response to the growing concern about the risk of climate change. The working group is assessing options for mitigating climate change through limiting greenhouse gas emissions.

The new research paper shows that it is possible to reduce poverty and cut carbon emission at the same time. The authors calculate that addressing extreme poverty by allowing almost 3 billion people to satisfy their basic energy needs with fossil fuels does not interfere with the goal of fossil fuel emissions reduction. The cap would need to be somewhat lower, and high emitters would need to reduce their energy consumption by a slightly larger percentage to make up the difference.

World leaders are expected to meet in Copenhagen in December 2009 for a conference to negotiate a treaty on global emission reductions to address climate change. The 1992 United Nations Framework Convention on Climate Change called upon the developed nations to reduce carbon emissions and provided the impetus for the binding 1997 Kyoto Protocol, but established no time frame for developing countries to follow. Developing countries now contribute more than half of global emissions, a share that is growing at a fast pace, Chakravarty said.

The paper is designed to address the current stalemate between developed and developing nations, with the developed world calling upon developing nations to share some of the burden of emission reductions, and the developing world pointing to the vast economic benefits already enjoyed by the developed world, with much of that wealth tied to fossil fuel use.

"U.N. rules and customs make it difficult for the international community to examine what is going on inside countries. That's probably why our simple proposal based on individual emissions has not emerged from the diplomats," Socolow said. "Over the next several decades, global environmental rulemaking will need new wisdom to accommodate developing countries whose per capita data belie the presence of both large populations of the very poor and upper and middle classes that are major consumers of resources. Our proposal is a start down this road."

The work is part of the Carbon Mitigation Initiative, which is based at Princeton. Launched in 2000, the project has produced new practical approaches to managing the carbon dioxide emissions that contribute to global warming. The initiative is aimed at supporting fundamental scientific, technological and environmental research that would lead to safe, effective and affordable solutions to climate change.

The authors believe the paper will be of relevance to climate negotiators as well as those forming national policies.

(Photo: PNAS)

Princeton University

SCIENTISTS ARE LEARNING MORE ABOUT BIG BIRDS FROM FEATHERS

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Catching adult eagles for research purposes is no easy task, but a Purdue University researcher has found a way around the problem, and, in the process, gathered even more information about the birds without ever laying a hand on one.

"Many birds are small, easy to catch and abundant," said Andrew DeWoody, associate professor of forestry and natural resources. "With eagles, the effort can be 100 to 1,000 times greater than catching chickadees."

Eagles can be hard to find, they often require live bait to attract and, with sharp talons and beaks capable of snapping off human fingers, they pose a risk to their would-be captors.

Instead of catching eagles, DeWoody collects their feathers and uses the small amount of DNA in them to create a tag that corresponds to a particular bird. Those tags can be used to determine population, parentage, roosting patterns and sex ratio.

"In an afternoon, you can go out and pick up hundreds of feathers," DeWoody said, "As field work goes, it's about as easy as it gets."

DeWoody's method is described in a chapter of the Handbook of Nature Conservation: Global and Economic Issues, which was released this week. The chapter is a compilation of his research on the topic.

Most birds are studied by catching them in nets and attaching tracking devices. Researchers can then follow the birds and use radio technology to triangulate their locations.

Eagles and other large birds present several challenges, however, even beyond catching them.

"Eagles will literally fly hundreds of miles in two days," DeWoody said. "They fly in areas where you can't track them in a pickup truck."

Capturing a bird as large as an eagle can often be traumatic to the animal.

"They're wild animals that don't want to be caught," DeWoody said. "They can get hurt as well. Using feathers, you avoid all that."

And costs can be as high as $5,000 for the tracking technology that researchers must attach to eagles, a prohibitive cost if studying more than a few birds.

DeWoody's studies were done in Kazakhstan with imperial eagles, a top predator of international concern because its population is declining.

The feathers give a good picture of recent eagle habits because they do not survive long in Kazakhstan's winters. Any feathers collected after the winter thaw, then, had to have been recently dropped. In one study, DeWoody's team found that an area thought to have about 40 juvenile eagles living in it based on human observation actually had closer to 300.

The work also helped researchers understand more about the roosting habits of some eagles that use a nest for months at a time versus others who float around from roost to roost. Another study showed that DNA could be used to distinguish eagle species from one another, and that imperial, golden and white-tailed eagles often utilized the same roosts at the same time.

(Photo: Purdue Agricultural Communication/Tom Campbell)

Purdue University

A PREHISTORIC POPEYE EFFECT? FOR THE DINOSAUR, FOOD MEANT BULK

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A University of Florida biologist thinks he knows how dinosaurs got so big. And it turns out, Popeye and Pachycephalosaurus may have a thing or two in common.

In a paper in the online edition of the Proceedings of the National Academy of Sciences, UF biology professor Brian McNab concludes that contrary to common belief, dinosaurs didn’t attain their colossal body sizes because they had more food to eat. Instead, McNab says, like Popeye with his spinach-induced bulging muscles, dinosaurs simply converted more of the energy in their food to body mass.

“Dinosaurs used energy in a different way than mammals use it. Mammals use much of their energy for body maintenance, temperature regulation and activity, and less of it for growth,” McNab says. “Dinosaurs used more energy for growth and less for maintenance.”

McNab argues that the conifers, ferns and other prehistoric plants that proliferated during the Mesozoic era ending 65 million years ago largely constituted “garbage food” that required a lot of energy to digest and provided little energy in return. Despite this limitation, dinosaurs were able to grow as much as eight times bigger than modern mammals, with the largest herbivores reaching weights of 40 to 80 tons or more – six to eight times an elephant’s weight of about 7 tons. (A large rhinoceros relative that lived in the Miocene weighed 11 to 15 tons and was the largest terrestrial mammal.)

Most of today’s herbivorous mammals can eat grasses, which were not present in the Mesozoic, and are a high-energy, more readily digestible forage, McNab noted. At the other end of the scale, plankton have a high energy content and are easy to digest, which is why the largest whales can reach weights of 160 tons, eclipsing the sizes of even the largest dinosaurs, he said.

McNab says dinosaurs attained their gigantic proportions because their biology apparently combined characteristics of modern warm-blooded and cold-blooded animals. On the one hand, they could regulate their own body temperature because of their large size and small relative surface area, he concludes. On the other, their metabolic rates were only about a quarter of those of mammals, but four times those of most reptiles.

Among modern animals, McNab says, those whose metabolisms most closely match those of dinosaurs are the varanid lizards, which include the Komodo dragon and other Monitor lizards.

“If you extrapolate varanid lizards’ metabolic rate up the metabolic rates of elephants, you get an animal that weighs 60 to 80 tons,” he says. “That’s the size of the biggest dinosaurs, the sauropods.”

University of Florida

FINDING FEAR: NEUROSCIENTISTS LOCATE WHERE IT IS PROCESSED IN MAMMALIAN BRAIN

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Using an imaging technique that enabled them to trace the process of neural activation in the brains of rats, University of Washington researchers have pinpointed the basolateral nucleus in the region of the brain called the of amygdala as the place where fear conditioning is encoded.

Neuroscientists previously suspected that both the amygdala and another brain region, the dorsal hippocampus, were where cues get associated when fear memories are formed. But the new work indicates that the role of the hippocampus is to process and transmit information about conditioned stimuli to the amygdala, said Ilene Bernstein, corresponding author of the new study and a UW professor of psychology.

The study has been published in PLoS One, a journal of the Public Library of Science.

Associative conditioning is a basic form of learning across the animal kingdom and is regularly used in studying how brain circuits can change as a result of experience. In earlier research, UW neuroscientists looked at taste aversion, another associative learning behavior, and found that neurons critical to how people and animals learn from experience are located in the amygdala.

The new work was designed to look for where information about conditioned and unconditioned stimuli converges in the brain as fear memories are formed. The researchers used four groups of rats and placed individual rodents inside of a chamber for 30 minutes. Three of the groups had never seen the chamber before.

When control rats were placed in the chamber, they explored it, became less active and some fell asleep. A delayed shock group also explored the chamber, became less active and after 26 minutes received an electric shock through the floor of the chamber. The third group was acclimated to the chamber by a series of 10 prior visits and then went through the same procedure as the delayed shock rats. The final group was shocked immediately upon being introduced inside the chamber.

The following day the rats were individually returned to the chamber and the researchers observed them for freezing behavior. Freezing, or not moving, is the most common behavioral measure of fear in rodents. The only rats that exhibited robust freezing were those that received the delayed shock in a chamber which was unfamiliar to them.

"We didn't know if we could delay the shock for 26 minutes and get a fear reaction after just one trial. I thought it would be impossible to do this with fear conditioning," said Bernstein. "This allowed us to ask where information converged in the brain."

To do this, the researchers repeated the procedure, but then killed the rats. They then took slices of the brains and used Arc catfish, an imaging technique, which allowed them to follow the pattern of neural activation in the animals.

Only the delayed shock group displayed evidence of converging activation from the conditioned stimulus (the chamber) and the unconditioned stimulus (the shock). The experiment showed that animals can acquire a long-term fear when a novel context is paired with a shock 26 minutes later, but not when a familiar context is matched with a shock.

"Fear learning and taste aversion learning are both examples of associative learning in which two experiences occur together. Often they are learned very rapidly because they are critical to survival, such as avoiding dangerous places or toxic foods," said Bernstein.

"People have phobias that often are set off by cues from something bad that happened to them, such as being scared by a snake or being in a dark alley. So they develop an anxiety disorder," she said.

"By understanding the process of fear conditioning we might learn how to treat anxiety by making the conditioning weaker or to go away. It is also a tool for learning about these brain cells and the underlying mechanism of fear conditioning."

University of Washington

ROBOT CAN CRAWL THROUGH HUMAN BODY

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Moving reality a step closer to "Fantastic Voyage," researchers at the Technion-Israel Institute of Technology have developed a micro robot that can crawl through the human body.

“Micro robots are being developed in many research centers, but this is the first time we’ve been able to create one that can crawl through the body,” says Professor Moshe Shoham of the Technion Faculty of Mechanical Engineering, who headed the university’s research team. Prof. Shoham is the developer of the FDA-approved SpineAssist spine-surgery robot.

The robot is propelled by micro legs, a mechanism especially adapted to the movements of a tiny body through water. It is only a millimeter in diameter and 14 millimeters long, fitting on the tip of a finger, so it can get into the body’s smallest areas. It is powered by either actuation through magnetic force located outside the body, or through an on-board actuation system. Made of silicone and metal, it can be made completely biocompatible, so it could remain in the body much as a stent placed in arteries does.

“In the future, we hope the robot will be able to travel through a blood vessel, the digestive tract or the lungs, delivering targeted medicines to specific locations, clearing blockages, performing biopsies, or placed inside a shunt to drain body fluids from clogged areas,” Shoham explains.

The development has been presented at scientific conferences where it has aroused great interest. Professor Menashe Zaaroor and research engineer Oded Salomon also participated in the research.

However, Prof. Shoham explains that a final product will not be ready for several years. A small enough camera needs to be developed, and an actuation device that will steer the robot once inside the body needs to be perfected. Animal trials are being performed, but human trials are about two years away.

(Photo: ATS)

American Society for Technion-Israel Institute of Technology

THE PROBLEM WITH SELF-HELP BOOKS: STUDY SHOWS THE NEGATIVE SIDE TO POSITIVE SELF-STATEMENTS

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Psychologists Joanne V. Wood and John W. Lee from the University of Waterloo, and W.Q. Elaine Perunovic from the University of New Brunswick, found that individuals with low self-esteem actually felt worse about themselves after repeating positive self-statements.

The researchers asked participants with low self-esteem and high self-esteem to repeat the self-help book phrase "I am a lovable person." The psychologists then measured the participants' moods and their momentary feelings about themselves. As it turned out, the individuals with low self-esteem felt worse after repeating the positive self-statement compared to another low self-esteem group who did not repeat the self-statement. The individuals with high self-esteem felt better after repeating the positive self-statement--but only slightly.

In a follow-up study, the psychologists allowed the participants to list negative self-thoughts along with positive self-thoughts. They found that, paradoxically, low self-esteem participants' moods fared better when they were allowed to have negative thoughts than when they were asked to focus exclusively on affirmative thoughts.

The psychologists suggested that, like overly positive praise, unreasonably positive self-statements, such as "I accept myself completely," can provoke contradictory thoughts in individuals with low self-esteem. Such negative thoughts can overwhelm the positive thoughts. And, if people are instructed to focus exclusively on positive thoughts, they may find negative thoughts to be especially discouraging.

As the authors concluded, "Repeating positive self-statements may benefit certain people [such as individuals with high self-esteem] but backfire for the very people who need them the most."

Psychological Science

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