>O2 LIFE >>> Can you Distinguish yourself from others?

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Distinguishing yourself from others

Figure 1: Groups of neurons in a specific part of the brain called the medial frontal cortex, which is associated with social learning, fire in ways that help individuals to distinguish between self and others. 

Credit: 2011 Masaki Isoda

 (Medical Xpress) — Researchers in Japan have identified the specific nerve cells responsible for the ability to distinguish between the actions of self and others. The discovery lays the foundations for studying social learning at the level of nerve cells using a new experimental technique. The work, led by Masaki Isoda from the Okinawa Institute of Science and Technology and Atsushi Iriki from the RIKEN Brain Science Institute, may lead to a better understanding of mental conditions where distinctions between self and others become confused.

Neuroscientists have long known that nerve cells called ‘mirror neurons’—found mainly in the brain’s cerebral cortex—fire when an individual performs an action or observes one performed by somebody else. The resulting information can be used as a basis for understanding others and for social interaction but, until now, a critical part of the puzzle was missing. If the same group of neurons fired when performing or observing an action, how could an individual distinguish self from other?

“Obviously, the brain needs a separate mechanism that enables one to make that distinction,” says Isoda. The researchers recognized that to find that mechanism they needed to develop an interactive task involving both observation and action that could be used to measure associated differences in the activity of neurons.
The task they designed involved two monkeys sitting face to face and taking turns to make choices of pushing one of two different colored buttons for a reward. Both monkeys were rewarded for a right choice and neither received a reward for a wrong choice. Each monkey had two turns, and then control would pass to the other. For blocks of between 5 and 17 turns, the color associated with the reward remained the same, but then it would change. So, observing which color was rewarded was important to success.
The researchers found the monkeys were quite capable of observing and learning from another’s action in planning their own response. Then, by monitoring the activity of 862 neurons in the medial frontal cortex (MFC) of the brain—which is associated with social cognition—they detected groups of neurons that were selectively activated only when a monkey’s partner performed the action. The researchers observed these ‘partner-fired’ neurons in dominant and submissive monkeys, and found they were most prevalent in the dorsomedial convexity region of the MFC (Fig. 1).
“In future, we hope to be able to identify the entire neuronal network and precise neuronal operation involved in self/other distinction,” Isoda says.

More information: Yoshida, K., et al. Representation of others’ action by neurons in monkey medial frontal cortex. Current Biology 21, 249–253 (2011). http://www.cell.co … 0960-9822(11)00027-3
Provided by RIKEN (news : web)

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>O2 HEALTH > new Chemical Pathway’ in the BRAIN for STRESS

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Neuroscientists discover new ‘chemical pathway’ in the brain for stress

Nerve cells (red) reach out and communicate with each other at junctions called synapses (green) that release chemicals to promote anxiety. Credit: University of Leicester

A team of neuroscientists at the University of Leicester, UK, in collaboration with researchers from Poland and Japan, has announced a breakthrough in the understanding of the ‘brain chemistry’ that triggers our response to highly stressful and traumatic events.

The discovery of a critical and previously unknown pathway in the brain that is linked to our response to stress is announced today in the journal Nature. The advance offers new hope for targeted treatment, or even prevention, of stress-related psychiatric disorders.
About 20% of the population experience some form of anxiety disorder at least once in their lives. The cumulative lifetime prevalence of all stress-related disorders is difficult to estimate but is probably higher than 30%.
Dr Robert Pawlak, from the University of Leicester who led the UK team, said: “Stress-related disorders affect a large percentage of the population and generate an enormous personal, social and economic impact. It was previously known that certain individuals are more susceptible to detrimental effects of stress than others. Although the majority of us experience traumatic events, only some develop stress-associated psychiatric disorders such as depression, anxiety or posttraumatic stress disorder. The reasons for this were not clear.”
Dr Pawlak added that a lack of correspondence between the commonness of exposure to psychological trauma and the development of pathological anxiety prompted the researchers to look for factors that may make some individuals more vulnerable to stress than others.
“We asked: What is the molecular basis of anxiety in response to noxious stimuli? How are stress-related environmental signals translated into proper behavioural responses? To investigate these problems we used a combination of genetic, molecular, electrophysiological and behavioural approaches. This resulted in the discovery of a critical, previously unknown pathway mediating anxiety in response to stress.”
The study found that the emotional centre of the brain – the amygdala – reacts to stress by increasing production of a protein called neuropsin. This triggers a series of chemical events which in turn cause the amygdala to increase its activity. As a consequence, a gene is turned on that determines the stress response at a cellular level.

“We then examined behavioural consequences of the above series of cellular events caused by stress in the amygdala,” said Dr Pawlak. “Studies in mice revealed that upon feeling stressed, they stayed away from zones in a maze where they felt unsafe. These were open and illuminated spaces they avoid when they are anxious.”

 

Newly discovered neurochemical cascade promoting stress-induced anxiety. Neuropsin interacts with cell membrane proteins NMDA and EphB2 to induce expression of the Fkbp5 gene. Credit: University of Leicester

“However when the proteins produced by the amygdala were blocked – either pharmacologically or by gene therapy – the mice did not exhibit the same traits. The behavioural consequences of stress were no longer present. We conclude that the activity of neuropsin and its partners may determine vulnerability to stress.” Neuropsin was previously discovered by Professor Sadao Shiosaka, a co-author of the paper. This research, for which the bioinformatics modelling was done by Professor Ryszard Przewlocki and his team, has for the first time characterized its mechanism of action in controlling anxiety in the amygdala.
The study took four years to complete, during which scientists from the Department of Cell Physiology and Pharmacology collaborated with colleagues from the Medical Research Council Toxicology Unit at the University of Leicester, the Department of Molecular Neuropharmacology, Polish Academy of Sciences in Krakow, Poland and Nara Institute of Science and Technology in Japan. The work was supported by the European Union, the Medical Research Council and Medisearch – the Leicestershire Medical Research Foundation. The first author, Benjamin Attwood, sponsored by Medisearch, took 3 years off from his medical studies curriculum to complete the necessary experiments. He commented: “It has been a thoroughly absorbing project to uncover how our experiences can change the way we behave. Hopefully this will lead to help for people that have to live with the damaging consequences of traumatic experiences.”
Dr Pawlak added: “We are tremendously excited about these findings. We know that all members of the neuropsin pathway are present in the human brain. They may play a similar role in humans and further research will be necessary to examine the potential of intervention therapies for controlling stress-induced behaviours.”
“Although research is now needed to translate our findings to the clinical situation, our discovery opens new possibilities for prevention and treatment of stress-related psychiatric disorders such as depression and posttraumatic stress disorder.”

More information: Neuropsin cleaves EphB2 in the amygdala to control anxiety, DOI: 10.1038/nature09938
Provided by University of Leicester (news : web)

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>O2 VISIONS >> Are we living in the age of UPHEAVALS ? >> GIANT EARTHQUAKES?

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Searching for patterns in the occurrence of large magnitude earthquakes after a succession of large tremors — surpassed by the recent magnitude-9.0 quake in Japan — has researchers wondering if the amount of big quakes is on the rise…

  

Street scene from Valdivia, Chile, after the 1960 magnitude-9.5 earthquake — the largest ever recorded. Credit: NOAA | Pierre St. Arnand

The devastating 2004 Indonesian tsunami, with its death toll of as many as 250,000 people, was caused by the first magnitude-9.0 earthquake since 1967. A succession of smaller but still destructive tremors in Haiti, Chile, and New Zealand — surpassed by this year’s magnitude-9.0 quake in Japan — has some researchers wondering whether the number of large earthquakes is on the rise.
An earthquake represents the abrupt release of seismic strain that has built up over the years as plates of the Earth’s crust slowly grind and catch against each other. Giant earthquakes live up to their fearsome name. The biggest ever recorded was the magnitude-9.5 Chile earthquake of 1960. It accounts for about a quarter of the total seismic strain released worldwide since 1900. In just three minutes, the recent quake in Japan unleashed one-twentieth of that global total according to geophysicist Richard Aster at the New Mexico Institute of Mining and Technology in Socorro.
The Indonesian quake “reinvigorated interest in these giants,” said Aster, who is also president of the Seismological Society of America. The Chile and Japan earthquakes — along with a magnitude-9.2 quake in Alaska in 1964 — also triggered catastrophic tsunamis.
After a lull in large quakes in the 1980s and 1990s, we may now be in the middle of a new age of large earthquakes, Aster added.
Records from the past century reveal some periods that have seen an unusual number of giant earthquakes, defined as those with magnitude 8.0 or higher. For example, global seismic data show a dramatic spike in the rate of large earthquakes from 1950-67. But there have also been quiet periods with fewer large quakes. And with only 100 years worth of records to consult, researchers aren’t sure what these patterns of large quakes might mean — or whether they mean anything at all.

Tsunami damage along the waterfront of Kodiak, Alaska, after the 1964 magnitude-9.2 quake. Credit: USGS

Even if clusters of giant earthquakes are a real phenomenon, Aster noted, researchers don’t have any good ideas on how one big quake can trigger another big one in a different part of the world.

Earthquakes are well known to generate smaller aftershocks, including some at great distance. The Japan quake spawned small tremors as far away as Nebraska.
But Andrew Michael, a geophysicist at the U.S. Geological Survey in Menlo Park, Calif., has studied the patterns in large earthquake occurrences that remain once aftershocks are removed from the picture. “Overall, the pattern is random,” he said. Apparent clusters of large quakes can be explained simply as statistical flukes.
“Random doesn’t mean evenly spaced out,” Michael added. That’s why quakes can seem to bunch together in the historical record. He cautioned that such clusters may not mean anything for predicting future earthquakes, or for explaining how a cluster of quakes might occur.
He compared the pattern to a baseball player’s hitting slump. “It could mean that he needs to change something in his game. Or it could just be a random streak,” Michael said.
Further evidence against the significance of apparent clustering came in a recent study by Don Parsons of the U.S. Geological Survey in Menlo Park and Aaron Velasco of the University of Texas at El Paso, published in Nature Geosciences. They found that large earthquakes do not generate other large quakes on a global scale.
Aster acknowledged that the rarity of large earthquakes means that questions about possible connections between them are difficult to answer. “We see magnitude-7 earthquakes only 15 or so times a year and magnitude-9 earthquakes only a few times a century,” he said.
Michael said that until researchers know more about why the rate of large earthquakes varies over time “we shouldn’t be worrying less, but there’s no need for panic either.”
The recent spate of giant earthquakes may not signal more to come, but Aster said that “it’s undeniable that we’re becoming more and more vulnerable to the effects of earthquakes in general.”
Aster added that many rapidly growing cities around the world aren’t prepared for a large quake, while at the same time coastal communities are expanding into tsunami-prone areas. “We just have more people in precarious places,” he said.

Source: Inside Science News Service (news : web)

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>O2 VISIONS >> New way to create true-color 3-D holograms

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Researchers discover way to create true-color 3-D holograms

  by Bob Yirka

 

A view of a 3-dimensional green crane reconstructed by white-light illumination. 

Credit: Image © Science/AAAS

(PhysOrg.com) — Satoshi Kawata, 

Miyu Ozaki and their team of photonics physicists at Osaka University in Japan, have figured out a way to capture the original colors of an object in a still 3-D hologram by using plasmons (quantums of plasma oscillation) that are created when a silver sheathed material is bathed in simple white light. The discovery marks a new milestone in the development of true 3-D full color holograms. In their paper, published in Science magazine, the researchers show a rendered apple in all its natural red and green hues…

Holograms, of course, have been around for years, with the first images created in the 60’s. Back then the technique was to fire a laser at an object and then record the patterns of interference in the light waves onto a photo sensitive material. Later, rainbow type holograms (such as those used on credit cards) were, and still are, created by using a technique whereby white light is reflected off a silver backing through a plastic film that contains several different images of a single object.

Enlarge

Image (c) Science/AAAS

The team at Osaka took another approach, they use both lasers and white light. They first fire a laser at an object, say an apple, to create an interference pattern, but instead of just one laser color, they actually use three; red, green and blue. The interference pattern is then captured on a light sensitive material which is coated with silver (because it contains electrons that are easily excited by white light) and silicon dioxide (to help steer the waves). They then shine a steady white light on the metal sheathed material exciting the free electrons, causing the creation of surface plasmons, which results in the regeneration of the captured image as a true-color 3-D hologram; one that can be viewed from almost any angle and is the same colors as the original object.
Currently, the technique has only been shown to work on still images, and the results displayed on a very small surface area (about as big as a baseball card), but the results of research is nonetheless a very big step towards creating not just more realistic holograms, but true animated 3-D technology.

More information: “Surface-Plasmon Holography with White-Light Illumination,” by M. Ozaki et al., Science 8 April 2011: Vol. 332 no. 6026 pp. 218-220. DOI: 10.1126/science.1201045
© 2010 PhysOrg.com

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>The Economic Impact Of The Crisis In Japan

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Q&A: The Economic Impact Of The Crisis In Japan

by David Kestenbaum

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All Things Considered

[3 min 39 sec]

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Is the crisis in Japan an economic disaster?
Since World War II, Japan has developed a very advanced and resilient economy. That means that when this crisis is over, it’s unlikely that there will be serious long-term economic impacts. The region affected accounts for only 4 percent of the country’s gross domestic product, and it’s only part of the region that’s affected. The main question mark at this point is the situation with the nuclear reactors.
Will the rebuilding effort be a sort of economic stimulus?
It is true that when you rebuild, you often see a bump in GDP. You are hiring people to rebuild those roads, rebuild those houses. But the money has to come from somewhere. That means Japan’s going to have to raise taxes, or cut spending elsewhere, or borrow more money.
  What will this mean for Japan’s debt?
Japan is one of the most indebted countries in the world. But people are still willing to lend money to Japan. The government can borrow money at a very low rate right now. It does seem that when the time comes to rebuild, the country will be able to borrow money if they need to.
What will the effect of this be on the U.S. economy?
Companies after previous natural disasters have really become obsessed with diversifying their supply chain — making sure they have multiple places to buy the things they need. There’s a lot of redundancy in the system. You might expect some short-term disruptions, but these things tend to fix themselves relatively quickly.
The most recent major disaster in Japan was the Kobe earthquake of 1995. What were the economic consequences of that?
I have a chart of Japan’s GDP, and if you look it’s very hard to find the impact of the Kobe earthquake there. GDP increased after the Kobe earthquake.
But GDP doesn’t measure lost buildings, it doesn’t measure lost houses, it doesn’t measure lost lives. There are an awful lot of things that just do not show up in the economic data.

Source: NPR

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