The secret behind Mona Lisa's enigmatic smile has been explained by scientists who believe it changes depending on which part of the eye sees it first.
One of the charms of the world's most famous painting is that she appears radiant one moment and then serious and sardonic the next.
Now scientists claim to have come up with an answer to her changing moods - our eyes are sending mixed signals to the brain. They believe Mona Lisa's smile depends on what cells in the retina pick up the image and what channel the image is transmitted through in the brain. Sometimes one channel wins over the other, and you see the smile, sometimes others take over and you do not see the smile.Different cells in the eye are designed to pick up different colours, contrasts, backgrounds and foregrounds. Some deal with central vision while others with peripheral.
Depending on what cells picks up the image first depends on what channel they are sent to the brian for interpreting.
These channels encode data about an object's size, clarity, brightness and location in the visual field."Sometimes one channel wins over the other, and you see the smile, sometimes others take over and you don't see the smile," said Dr Luis Martinez Otero, a neuroscientist at Institute of Neuroscience in Alicante, Spain, who conducted the study, told New Scientist.
To get a fuller picture of the reasons behind Mona Lisa's vanishing smile, Dr Martinez Otero varied different aspects of the Mona Lisa that are processed by different visual channels, and then asked volunteers whether they saw a smile or not.
To start with, the duo asked volunteers to look at the painting in varying sizes from varying distances. They found the closer you were the more likely you were to see the smile.
Next, Dr Martinez Otero's team compared how light affects our judgement of Mona Lisa's smile. Two kinds of cells determine the brightness of an object relative to its surroundings - "on-centre" cells, which are stimulated only when their centres are illuminated, and allow us to see a bright star in a dark night; and "off-centre" cells, which turn on only when their centres are dark, and allow us to pick out words on a printed page.
Dr Martinez Otero jammed these channels by showing another set of volunteers either a black or white screen for 30 seconds followed by a shot of the Mona Lisa. The black would mute off centre cells while the light on-centre. Volunteers were more likely to see Mona Lisa's smile after they had been shown the dark screen, leading Martinez Otero to conclude that it is these the on-centre cells that sense the Mona Lisa's smile.
Eye gaze also affects how volunteers see the smile, Martinez Otero says. His team used software to track where in the painting 20 volunteers gazed while they rated whether or not Mona Lisa's smile became more or less apparent.
With a minute to gaze at the painting, volunteers tended to focus on the left side of her mouth when judging her as smiling – further evidence that dead-centre vision picks out the smile.
When volunteers had only a fraction of a second to discern her smile, their eyes tended to focus on her left cheek, hinting that peripheral vision plays a role, too.
So did Leonardo intend to sow so much confusion in the brains of viewers, not to mention scientists? Absolutely, Martinez Otero contends. "He wrote in one of his notebooks that he was trying to paint dynamic expressions because that's what he saw in the street."
The research was originally presented at the Society for Neuroscience's annual meeting in Chicago.This isn't the first time scientists have deconstructed Leonardo da Vinci's masterpiece.
In 2000, Margaret Livingstone, a neuroscientist at Harvard Medical School with a side interest in art history, showed that Mona Lisa's smile is more apparent in peripheral visionMovie Camera than dead-centre vision.
This story can be read at the below link:
Thursday, November 5, 2009
Do "Skeleton" Filaments Give Structure to the Universe?
Are there "skeletons" out in the Universe –structures that form the framework of how galaxies are distributed? Astronomers have tracked down a gigantic, previously unknown assembly of galaxies located almost seven billion light-years away from us, which seems to point to a prominent galaxy structure in the distant Universe, providing further insight into the cosmic web and how it formed. “Matter is not distributed uniformly in the Universe,” says Masayuki Tanaka from ESO, who led the new study. “In our cosmic vicinity, stars form in galaxies and galaxies usually form groups and clusters of galaxies. The most widely accepted cosmological theories predict that matter also clumps on a larger scale in the so-called ‘cosmic web’, in which galaxies, embedded in filaments stretching between voids, create a gigantic wispy structure.”
More on this at:
Mild Exercise Boosts Lifespan Of Heart Patients
Mild exercise can significantly reduce the risk of early death from heart disease, according to a new study published in the American Journal of Medicine.
Just half an hour of jogging or riding a bike three times a week reduced the risk of early death by 60 percent, the research found.
Heart disease is the largest killer in the United States, and the number of people suffering from the condition is expected to rise as the population ages and obesity rates increase.
The study found that the most significant gains were realized in patients who were also stressed. Researchers believe this is due to the fact that stress can quadruple the risk of death in those with heart and circulation problems.
In these patients, exercise can offer the double benefit of reducing stress levels while also improving cardiovascular health.
“Exercise reduces mortality in patients with coronary artery disease…in part because of the effects on psycho social stress,” the researchers said.
Heart patients are typically put on drugs such as statins, which lower cholesterol levels, and blood pressure medication to reduce the risk of death from strokes, heart attacks and heart disease.
Previous studies have demonstrated a variety of life-extending benefits from exercise, including a reduced risk of cancer, heart disease and neurological disorders and slower rates of death and disability.
These benefits are due to the ability of exercise to improve the health of hearts and arteries, strengthen bones, lessen inflammation, boost the immune system and improve thinking, learning and memory.
The latest study, conducted by the Department of Cardiology in New Orleans, describes just how much these simple alterations can increase lifespan.
The researchers followed 522 cardiac patients, including 53 with high stress levels and 27 control patients who also had high stress levels but went without cardiac rehabilitation.
The patients were offered 12 weeks of exercise classes, which included a 10 minute warm-up, 30 to 40 minutes of aerobic exercise such as jogging, walking or rowing, and 10 minutes of stretching. The classes were conducted three times per week, with participants asked to do an additional one-to-three sessions each week on their own. The patients were also advised on lifestyle and diet improvements.
More on this at:
http://www.redorbit.com/news/health/1778952/mild_exercise_boosts_lifespan_of_heart_patients/index.html
Just half an hour of jogging or riding a bike three times a week reduced the risk of early death by 60 percent, the research found.
Heart disease is the largest killer in the United States, and the number of people suffering from the condition is expected to rise as the population ages and obesity rates increase.
The study found that the most significant gains were realized in patients who were also stressed. Researchers believe this is due to the fact that stress can quadruple the risk of death in those with heart and circulation problems.
In these patients, exercise can offer the double benefit of reducing stress levels while also improving cardiovascular health.
“Exercise reduces mortality in patients with coronary artery disease…in part because of the effects on psycho social stress,” the researchers said.
Heart patients are typically put on drugs such as statins, which lower cholesterol levels, and blood pressure medication to reduce the risk of death from strokes, heart attacks and heart disease.
Previous studies have demonstrated a variety of life-extending benefits from exercise, including a reduced risk of cancer, heart disease and neurological disorders and slower rates of death and disability.
These benefits are due to the ability of exercise to improve the health of hearts and arteries, strengthen bones, lessen inflammation, boost the immune system and improve thinking, learning and memory.
The latest study, conducted by the Department of Cardiology in New Orleans, describes just how much these simple alterations can increase lifespan.
The researchers followed 522 cardiac patients, including 53 with high stress levels and 27 control patients who also had high stress levels but went without cardiac rehabilitation.
The patients were offered 12 weeks of exercise classes, which included a 10 minute warm-up, 30 to 40 minutes of aerobic exercise such as jogging, walking or rowing, and 10 minutes of stretching. The classes were conducted three times per week, with participants asked to do an additional one-to-three sessions each week on their own. The patients were also advised on lifestyle and diet improvements.
http://www.redorbit.com/news/health/1778952/mild_exercise_boosts_lifespan_of_heart_patients/index.html
A New Wrinkle in Ancient Ocean Chemistry
Scientists widely accept that around 2.4 billion years ago, the Earth's atmosphere underwent a dramatic change when oxygen levels rose sharply. Called the "Great Oxidation Event" (GOE), the oxygen spike marks an important milestone in Earth's history, the transformation from an oxygen-poor atmosphere to an oxygen-rich one paving the way for complex life to develop on the planet.
Two questions that remain unresolved in studies of the early Earth are when oxygen production via photosynthesis got started and when it began to alter the chemistry of Earth's ocean and atmosphere.
Now a research team led by geoscientists at the University of California, Riverside corroborates recent evidence that oxygen production began in Earth's oceans at least 100 million years before the GOE, and goes a step further in demonstrating that even very low concentrations of oxygen can have profound effects on ocean chemistry.
To arrive at their results, the researchers analyzed 2.5 billion-year-old black shales from Western Australia. Essentially representing fossilized pieces of the ancient seafloor, the fine layers within the rocks allowed the researchers to page through ocean chemistry's evolving history.
Specifically, the shales revealed that episodes of hydrogen sulfide accumulation in the oxygen-free deep ocean occurred nearly 100 million years before the GOE and up to 700 millaion years earlier than such conditions were predicted by past models for the early ocean. Scientists have long believed that the early ocean, for more than half of Earth's 4.6 billion-year history, was characterized instead by high amounts of dissolved iron under conditions of essentially no oxygen.
More on this at:
http://www.astrobio.net/pressrelease/3297/a-new-wrinkle-in-ancient-ocean-chemistry
Two questions that remain unresolved in studies of the early Earth are when oxygen production via photosynthesis got started and when it began to alter the chemistry of Earth's ocean and atmosphere.
Now a research team led by geoscientists at the University of California, Riverside corroborates recent evidence that oxygen production began in Earth's oceans at least 100 million years before the GOE, and goes a step further in demonstrating that even very low concentrations of oxygen can have profound effects on ocean chemistry.
To arrive at their results, the researchers analyzed 2.5 billion-year-old black shales from Western Australia. Essentially representing fossilized pieces of the ancient seafloor, the fine layers within the rocks allowed the researchers to page through ocean chemistry's evolving history.
Specifically, the shales revealed that episodes of hydrogen sulfide accumulation in the oxygen-free deep ocean occurred nearly 100 million years before the GOE and up to 700 millaion years earlier than such conditions were predicted by past models for the early ocean. Scientists have long believed that the early ocean, for more than half of Earth's 4.6 billion-year history, was characterized instead by high amounts of dissolved iron under conditions of essentially no oxygen.
http://www.astrobio.net/pressrelease/3297/a-new-wrinkle-in-ancient-ocean-chemistry
African desert rift confirmed as new ocean in the making
Published: Monday, November 2, 2009 - 14:57 in Earth & Climate
In 2005, a gigantic, 35-mile-long rift broke open the desert ground in Ethiopia. At the time, some geologists believed the rift was the beginning of a new ocean as two parts of the African continent pulled apart, but the claim was controversial. Now, scientists from several countries have confirmed that the volcanic processes at work beneath the Ethiopian rift are nearly identical to those at the bottom of the world's oceans, and the rift is indeed likely the beginning of a new sea.
The new study, published in the latest issue of Geophysical Research Letters, suggests that the highly active volcanic boundaries along the edges of tectonic ocean plates may suddenly break apart in large sections, instead of little by little as has been predominantly believed. In addition, such sudden large-scale events on land pose a much more serious hazard to populations living near the rift than would several smaller events, says Cindy Ebinger, professor of earth and environmental sciences at the University of Rochester and co-author of the study.
"This work is a breakthrough in our understanding of continental rifting leading to the creation of new ocean basins," says Ken Macdonald, professor emeritus in the Department of Earth Science at the University of California, Santa Barbara, and who is not affiliated with the research. "For the first time they demonstrate that activity on one rift segment can trigger a major episode of magma injection and associated deformation on a neighboring segment. Careful study of the 2005 mega-dike intrusion and its aftermath will continue to provide extraordinary opportunities for learning about continental rifts and mid-ocean ridges."
"The whole point of this study is to learn whether what is happening in Ethiopia is like what is happening at the bottom of the ocean where it's almost impossible for us to go," says Ebinger. "We knew that if we could establish that, then Ethiopia would essentially be a unique and superb ocean-ridge laboratory for us. Because of the unprecedented cross-border collaboration behind this research, we now know that the answer is yes, it is analogous."
Atalay Ayele, professor at the Addis Ababa University in Ethiopia, led the investigation, painstakingly gathering seismic data surrounding the 2005 event that led to the giant rift opening more than 20 feet in width in just days. Along with the seismic information from Ethiopia, Ayele combined data from neighboring Eritrea with the help of Ghebrebrhan Ogubazghi, professor at the Eritrea Institute of Technology, and from Yemen with the help of Jamal Sholan of the National Yemen Seismological Observatory Center. The map he drew of when and where earthquakes happened in the region fit tremendously well with the more detailed analyses Ebinger has conducted in more recent years.
Ayele's reconstruction of events showed that the rift did not open in a series of small earthquakes over an extended period of time, but tore open along its entire 35-mile length in just days. A volcano called Dabbahu at the northern end of the rift erupted first, then magma pushed up through the middle of the rift area and began "unzipping" the rift in both directions, says Ebinger.
Since the 2005 event, Ebinger and her colleagues have installed seismometers and measured 12 similar—though dramatically less intense—events.
"We know that seafloor ridges are created by a similar intrusion of magma into a rift, but we never knew that a huge length of the ridge could break open at once like this," says Ebinger. She explains that since the areas where the seafloor is spreading are almost always situated under miles of ocean, it's nearly impossible to monitor more than a small section of the ridge at once so there's no way for geologists to know how much of the ridge may break open and spread at any one time. "Seafloor ridges are made up of sections, each of which can be hundreds of miles long. Because of this study, we now know that each one of those segments can tear open in a just a few days."
Ebinger and her colleagues are continuing to monitor the area in Ethiopia to learn more about how the magma system beneath the rift evolves as the rift continues to grow.
Source: University of Rochester
Link to this story: http://esciencenews.com/articles/2009/11/02/african.desert.rift.confirmed.new.ocean.making
In 2005, a gigantic, 35-mile-long rift broke open the desert ground in Ethiopia. At the time, some geologists believed the rift was the beginning of a new ocean as two parts of the African continent pulled apart, but the claim was controversial. Now, scientists from several countries have confirmed that the volcanic processes at work beneath the Ethiopian rift are nearly identical to those at the bottom of the world's oceans, and the rift is indeed likely the beginning of a new sea.
The new study, published in the latest issue of Geophysical Research Letters, suggests that the highly active volcanic boundaries along the edges of tectonic ocean plates may suddenly break apart in large sections, instead of little by little as has been predominantly believed. In addition, such sudden large-scale events on land pose a much more serious hazard to populations living near the rift than would several smaller events, says Cindy Ebinger, professor of earth and environmental sciences at the University of Rochester and co-author of the study.
"This work is a breakthrough in our understanding of continental rifting leading to the creation of new ocean basins," says Ken Macdonald, professor emeritus in the Department of Earth Science at the University of California, Santa Barbara, and who is not affiliated with the research. "For the first time they demonstrate that activity on one rift segment can trigger a major episode of magma injection and associated deformation on a neighboring segment. Careful study of the 2005 mega-dike intrusion and its aftermath will continue to provide extraordinary opportunities for learning about continental rifts and mid-ocean ridges."
"The whole point of this study is to learn whether what is happening in Ethiopia is like what is happening at the bottom of the ocean where it's almost impossible for us to go," says Ebinger. "We knew that if we could establish that, then Ethiopia would essentially be a unique and superb ocean-ridge laboratory for us. Because of the unprecedented cross-border collaboration behind this research, we now know that the answer is yes, it is analogous."
Atalay Ayele, professor at the Addis Ababa University in Ethiopia, led the investigation, painstakingly gathering seismic data surrounding the 2005 event that led to the giant rift opening more than 20 feet in width in just days. Along with the seismic information from Ethiopia, Ayele combined data from neighboring Eritrea with the help of Ghebrebrhan Ogubazghi, professor at the Eritrea Institute of Technology, and from Yemen with the help of Jamal Sholan of the National Yemen Seismological Observatory Center. The map he drew of when and where earthquakes happened in the region fit tremendously well with the more detailed analyses Ebinger has conducted in more recent years.
Ayele's reconstruction of events showed that the rift did not open in a series of small earthquakes over an extended period of time, but tore open along its entire 35-mile length in just days. A volcano called Dabbahu at the northern end of the rift erupted first, then magma pushed up through the middle of the rift area and began "unzipping" the rift in both directions, says Ebinger.
Since the 2005 event, Ebinger and her colleagues have installed seismometers and measured 12 similar—though dramatically less intense—events.
"We know that seafloor ridges are created by a similar intrusion of magma into a rift, but we never knew that a huge length of the ridge could break open at once like this," says Ebinger. She explains that since the areas where the seafloor is spreading are almost always situated under miles of ocean, it's nearly impossible to monitor more than a small section of the ridge at once so there's no way for geologists to know how much of the ridge may break open and spread at any one time. "Seafloor ridges are made up of sections, each of which can be hundreds of miles long. Because of this study, we now know that each one of those segments can tear open in a just a few days."
Ebinger and her colleagues are continuing to monitor the area in Ethiopia to learn more about how the magma system beneath the rift evolves as the rift continues to grow.
Source: University of Rochester
Link to this story: http://esciencenews.com/articles/2009/11/02/african.desert.rift.confirmed.new.ocean.making
VOLCANIC AND FERRIC SURPRISES ON MERCURY
New images from the MESSENGER spacecraft’s third trip past Mercury reveal some of the most recent volcanic activity on the planet’s surface, scientists reported during a press teleconference November 3.
The images are evidence of activity recent enough that planetary scientists may need to rethink the planet’s history. “It was thought that the internal geological activity on Mercury ended much earlier than on any other planet,” said Brett Denevi of Arizona State University. “We’re seeing that might not be the case.”
More on this story at http://www.sciencenews.org/view/generic/id/49071/title/Volcanic_and_ferric_surprises_on_Mercury
Friday, October 30, 2009
Volcanoes Played Role In Ancient Ice Age, Mass Extinction
Researchers here have discovered the pivotal role that volcanoes played in a deadly ice age 450 million years ago.
Perhaps ironically, these volcanoes first caused global warming -- by releasing massive amounts of carbon dioxide into the atmosphere.
When they stopped erupting, Earth’s climate was thrown off balance, and the ice age began.
The discovery underscores the importance of carbon in Earth’s climate today, said Matthew Saltzman, associate professor of earth sciences at Ohio State University.
The results will appear in the journal Geology, in a paper now available online.
Previously, Saltzman and his team linked this same ice age to the rise of the Appalachian Mountains. As the exposed rock weathered, chemical reactions pulled carbon from Earth’s atmosphere, causing a global cooling which ultimately killed two-thirds of all species on the planet.
Now the researchers have discovered the other half of the story: giant volcanoes that formed during the closing of the proto-Atlantic Ocean -- known as the Iapetus Ocean -- set the stage for the rise of the Appalachians and the ice age that followed.
“Our model shows that these Atlantic volcanoes were spewing carbon into the atmosphere at the same time the Appalachians were removing it,” Saltzman explained. “For nearly 10 million years, the climate was at a stalemate. Then the eruptions abruptly stopped, and atmospheric carbon levels fell well below what they were in the time before volcanism. That kicked off the ice age,” he said.
This is the first evidence that a decrease in carbon from volcanic degassing -- combined with continued weathering of the Appalachians -- caused the long-enigmatic glaciation and extinction in the Ordovician period.
Here is the picture the researchers have assembled: 460 million years ago, during the Ordovician, volcanoes along the margin of what is now the Atlantic Ocean spewed massive amounts carbon dioxide into the atmosphere, turning the world into a hothouse. Lava from those volcanoes eventually collided with North America to form the Appalachian Mountains.
Acid rain -- rich in carbon dioxide -- pelted the newly exposed Appalachian rock and wore it away. Chemical reactions trapped the carbon in the resulting sediment, which formed reefs in the vast seas that covered North America.
For about 10 million years, the volcanoes continued to add carbon to the atmosphere as the Appalachians removed it, so the hothouse conditions remained stable. Life flourished in the warm oceans, including abundant species of trilobites and brachiopods.
Then, 450 million years ago, the eruptions stopped. But the Appalachians continued weathering, and atmospheric carbon levels plummeted. The Earth swung from a hothouse to an icehouse.
By 445 million years ago, glaciers had covered the south pole on top of the supercontinent of Gondwana (which would eventually break apart to form the continents of the southern hemisphere). Two-thirds of all species had perished.
When they started this research, Saltzman and his team knew that Earth’s climate must have changed drastically at the end of the Ordovician. But they didn’t know for certain that volcanoes were the driving force, explained Seth Young, who did this research for his doctoral degree at Ohio State. He is now a postdoctoral researcher at Indiana University.
“This was not necessarily what we expected when we started investigating, but as we combined our data sources, the story began to fall into place,” Young said.
Using a computer model, they drew together measurements of isotopes of chemical elements -- including strontium from rocks in Nevada and neodymium from rocks in Virginia and Pennsylvania -- with measurements of volcanic ash beds in the same locations. Then they factored in temperature models developed by other researchers.
The ash deposits demonstrated when the volcanoes stopped erupting; the strontium levels indicated that large amounts of volcanic rock were being eroded and the sediment was flooding Earth’s oceans during this time; and the neodymium levels pinpointed the Appalachians as the source of the sediment.
The new findings mesh well with what scientists know about these ancient proto-Atlantic volcanoes, which are thought to have produced the largest eruptions in Earth’s history. They issued enough lava to form the Appalachians, enough ash to cover the far ends of the earth, and enough carbon to heat the globe. Atmospheric carbon levels grew 20 times higher than they are today.
This study shows that when those volcanoes stopped erupting, carbon levels dropped, and the climate swung dramatically back to cold. The timing coincides with today’s best estimates of temperature fluctuations in the Ordovician.
“The ash beds start building up at the same time the Appalachian weathering begins, but then the record of volcanism ends, and the temperature drops,” Saltzman said. “Knowing these details can help us understand how carbon in the atmosphere is changing Earth’s climate today.”
Next, the researchers will examine the role of the ancient volcanic ash more closely. While the ash was in the atmosphere -- before it settled around the globe -- it might have blotted out the sun, and cooled the earth somewhat. Saltzman and his team want to make some estimate of this short-term cooling effect to refine their computer model.
Meanwhile, Young is just starting to re-analyze the same rock samples, this time looking for a different isotope -- sulfur. This, he hopes, will offer clues to how much oxygen was in the oceans, and how that oxygen may have affected life in the Ordovician.
Other contributors to this work include Kenneth Foland, professor emeritus of earth sciences, and Jeff Linder, a research associate, both of Ohio State; and Lee Kump, professor of geosciences at Pennsylvania State University.
This research was partly supported by the National Science Foundation.
original story at http://www.redorbit.com/news/science/1775126/volcanoes_played_role_in_ancient_ice_age_mass_extinction/index.html
Perhaps ironically, these volcanoes first caused global warming -- by releasing massive amounts of carbon dioxide into the atmosphere.
When they stopped erupting, Earth’s climate was thrown off balance, and the ice age began.
The discovery underscores the importance of carbon in Earth’s climate today, said Matthew Saltzman, associate professor of earth sciences at Ohio State University.
The results will appear in the journal Geology, in a paper now available online.
Previously, Saltzman and his team linked this same ice age to the rise of the Appalachian Mountains. As the exposed rock weathered, chemical reactions pulled carbon from Earth’s atmosphere, causing a global cooling which ultimately killed two-thirds of all species on the planet.
Now the researchers have discovered the other half of the story: giant volcanoes that formed during the closing of the proto-Atlantic Ocean -- known as the Iapetus Ocean -- set the stage for the rise of the Appalachians and the ice age that followed.
“Our model shows that these Atlantic volcanoes were spewing carbon into the atmosphere at the same time the Appalachians were removing it,” Saltzman explained. “For nearly 10 million years, the climate was at a stalemate. Then the eruptions abruptly stopped, and atmospheric carbon levels fell well below what they were in the time before volcanism. That kicked off the ice age,” he said.
This is the first evidence that a decrease in carbon from volcanic degassing -- combined with continued weathering of the Appalachians -- caused the long-enigmatic glaciation and extinction in the Ordovician period.
Here is the picture the researchers have assembled: 460 million years ago, during the Ordovician, volcanoes along the margin of what is now the Atlantic Ocean spewed massive amounts carbon dioxide into the atmosphere, turning the world into a hothouse. Lava from those volcanoes eventually collided with North America to form the Appalachian Mountains.
Acid rain -- rich in carbon dioxide -- pelted the newly exposed Appalachian rock and wore it away. Chemical reactions trapped the carbon in the resulting sediment, which formed reefs in the vast seas that covered North America.
For about 10 million years, the volcanoes continued to add carbon to the atmosphere as the Appalachians removed it, so the hothouse conditions remained stable. Life flourished in the warm oceans, including abundant species of trilobites and brachiopods.
Then, 450 million years ago, the eruptions stopped. But the Appalachians continued weathering, and atmospheric carbon levels plummeted. The Earth swung from a hothouse to an icehouse.
By 445 million years ago, glaciers had covered the south pole on top of the supercontinent of Gondwana (which would eventually break apart to form the continents of the southern hemisphere). Two-thirds of all species had perished.
When they started this research, Saltzman and his team knew that Earth’s climate must have changed drastically at the end of the Ordovician. But they didn’t know for certain that volcanoes were the driving force, explained Seth Young, who did this research for his doctoral degree at Ohio State. He is now a postdoctoral researcher at Indiana University.
“This was not necessarily what we expected when we started investigating, but as we combined our data sources, the story began to fall into place,” Young said.
Using a computer model, they drew together measurements of isotopes of chemical elements -- including strontium from rocks in Nevada and neodymium from rocks in Virginia and Pennsylvania -- with measurements of volcanic ash beds in the same locations. Then they factored in temperature models developed by other researchers.
The ash deposits demonstrated when the volcanoes stopped erupting; the strontium levels indicated that large amounts of volcanic rock were being eroded and the sediment was flooding Earth’s oceans during this time; and the neodymium levels pinpointed the Appalachians as the source of the sediment.
The new findings mesh well with what scientists know about these ancient proto-Atlantic volcanoes, which are thought to have produced the largest eruptions in Earth’s history. They issued enough lava to form the Appalachians, enough ash to cover the far ends of the earth, and enough carbon to heat the globe. Atmospheric carbon levels grew 20 times higher than they are today.
This study shows that when those volcanoes stopped erupting, carbon levels dropped, and the climate swung dramatically back to cold. The timing coincides with today’s best estimates of temperature fluctuations in the Ordovician.
“The ash beds start building up at the same time the Appalachian weathering begins, but then the record of volcanism ends, and the temperature drops,” Saltzman said. “Knowing these details can help us understand how carbon in the atmosphere is changing Earth’s climate today.”
Next, the researchers will examine the role of the ancient volcanic ash more closely. While the ash was in the atmosphere -- before it settled around the globe -- it might have blotted out the sun, and cooled the earth somewhat. Saltzman and his team want to make some estimate of this short-term cooling effect to refine their computer model.
Meanwhile, Young is just starting to re-analyze the same rock samples, this time looking for a different isotope -- sulfur. This, he hopes, will offer clues to how much oxygen was in the oceans, and how that oxygen may have affected life in the Ordovician.
Other contributors to this work include Kenneth Foland, professor emeritus of earth sciences, and Jeff Linder, a research associate, both of Ohio State; and Lee Kump, professor of geosciences at Pennsylvania State University.
This research was partly supported by the National Science Foundation.
original story at http://www.redorbit.com/news/science/1775126/volcanoes_played_role_in_ancient_ice_age_mass_extinction/index.html
Exercise makes cigarettes less attractive to smokers
Source: University of Exeter
Exercise can help smokers quit because it makes cigarettes less attractive. A new study from the University of Exeter shows for the first time that exercise can lessen the power of cigarettes and smoking-related images to grab the attention of smokers. The study is published in the journal Addiction. The study involved 20 moderately heavy smokers, who had abstained from cigarettes for 15 hours before the trial. During two visits to our laboratory participants began by being shown smoking-related and neutral images, and then spent either 15 minutes sitting or exercising on a stationary bike at a moderate intensity. Afterwards, they were again shown the images.
While the participants were shown the images, the research team used the latest eye tracking technology to measure and record their precise eye movements. They were able to show not only the length of time people looked at smoking-related images but also how quickly pictures of cigarettes could grab their attention, compared with non-smoking matched images.
The study showed an 11% difference between the time the participants spent looking at the smoking-related images after exercise, compared with the after sitting. Also, after exercise, participants took longer to look at smoking-related images. Exercise, therefore, appears to reduce the power of the smoking-related images to grab visual attention.
Numerous studies have shown that a single session of light to moderate intensity exercise, for example five-15 minutes of brisk walking, can reduce cravings and responses to smoking cues. This is the first time eye-tracking technology has been used to show that exercise can reduce interest in and salience of smoking cues that, outside the laboratory, may cause lapses and relapse among smokers trying to quit.
Lead author, University of Exeter PhD student Kate Janse Van Rensburg said: "We know that smoking-related images can be powerful triggers for smokers who are abstaining. While we are no longer faced with advertisements for cigarettes, smokers are still faced with seeing people smoking on television, in photographs or in person. We know that this makes it more difficult for them to quit.
"Because of this, it's very exciting to find that just a short burst of exercise can somewhat reduce the power of such images. It is not clear if longer or more vigorous bouts of exercise have a bigger effect. This study adds to the growing evidence that exercise can be a great help for people trying to give up smoking."
Exercise can help smokers quit because it makes cigarettes less attractive. A new study from the University of Exeter shows for the first time that exercise can lessen the power of cigarettes and smoking-related images to grab the attention of smokers. The study is published in the journal Addiction. The study involved 20 moderately heavy smokers, who had abstained from cigarettes for 15 hours before the trial. During two visits to our laboratory participants began by being shown smoking-related and neutral images, and then spent either 15 minutes sitting or exercising on a stationary bike at a moderate intensity. Afterwards, they were again shown the images.
While the participants were shown the images, the research team used the latest eye tracking technology to measure and record their precise eye movements. They were able to show not only the length of time people looked at smoking-related images but also how quickly pictures of cigarettes could grab their attention, compared with non-smoking matched images.
The study showed an 11% difference between the time the participants spent looking at the smoking-related images after exercise, compared with the after sitting. Also, after exercise, participants took longer to look at smoking-related images. Exercise, therefore, appears to reduce the power of the smoking-related images to grab visual attention.
Numerous studies have shown that a single session of light to moderate intensity exercise, for example five-15 minutes of brisk walking, can reduce cravings and responses to smoking cues. This is the first time eye-tracking technology has been used to show that exercise can reduce interest in and salience of smoking cues that, outside the laboratory, may cause lapses and relapse among smokers trying to quit.
Lead author, University of Exeter PhD student Kate Janse Van Rensburg said: "We know that smoking-related images can be powerful triggers for smokers who are abstaining. While we are no longer faced with advertisements for cigarettes, smokers are still faced with seeing people smoking on television, in photographs or in person. We know that this makes it more difficult for them to quit.
"Because of this, it's very exciting to find that just a short burst of exercise can somewhat reduce the power of such images. It is not clear if longer or more vigorous bouts of exercise have a bigger effect. This study adds to the growing evidence that exercise can be a great help for people trying to give up smoking."
How Galileo's spy glass upended science
Agence France-Presse
PARIS: It would hardly pass as a toy today, but the telescope Galileo used 400 years ago this week, overturned the foundations of knowledge, changing our perception of the universe and our place within it.
Galileo's 'optick tube' magnified a meagre nine-fold and was not even conceived of for astronomy.
Nevertheless, when the gadget was first demonstrated, Venetian senators were so smitten with its military potential that they doubled Galileo's salary and awarded him life tenure in the city-state's most prestigious university.
Paradigm shift
But when, in late October 1609, the 45-year-old Italian mathematician pointed his newfangled instrument - essentially two lenses aligned in a tube - skyward, what he glimpsed would unleash a scientific revolution and a rare paradigm shift in thought.
"He immediately made several surprising discoveries that contributed to the demise of the Earth-centred cosmology that had dominated Western thought for two millennia," says Robert Joseph, an astronomy at the University of Hawaii in Honolulu.
Using ever-more powerful telescopes over the next year, Galileo observed that the Moon was not perfectly smooth as claimed by Aristotle but cratered and mountainous.
He spotted hundreds of stars never seen before.
Galilean moons
More critically, he discovered the four inner satellites of Jupiter - still known as the "Galilean moons" today, in his honour - and learnt that Venus, Earth's closest planet, goes through a full range of phases.
Put together, his observations validated the revolutionary theory of Nicolaus Copernicus that Earth orbits the Sun, and not the other way round.
Galileo understood the implications of what he had seen, but the Catholic Church was not ready to accept such heresy. Only in 2000 did the Holy See apologise for putting Galileo on trial in 1633, forcing him to recant his ideas lest he face imprisonment or worse. The Vatican also paid tribute to him in an exhibition that opened this month.
But resistance to a solar-centric view was not only religious. The ancient Greek notion that Earth was at the centre of the cosmos was also a deeply ingrained scientific dogma, and it took decades to dislodge it.
Even the notion that "we can improve on our senses" by magnifying our vision was considered taboo, says Jerome Lamy, a science historian at the Paris Observatory in France.
Scientific revolution
The concept of paradigm shifts was first articulated by U.S. philosopher Thomas Kuhn in a 1962 book, "The Structure of Scientific Revolutions". A sea change in thinking entails not only the overturning of a theory but the creation of an entirely new world view, he said.
It happened again at the start of the 20th century, only a few years after Scottish mathematician Lord Kelvin had famously declared there was "nothing new" to be discovered in physics.
That seismic shift came in the form of a short paper on special relativity by a German-born patent clerk by the name of Albert Einstein.
Again, it did not happen overnight. But Einstein's ideas eventually toppled laws of physics that had prevailed for three centuries.
The God particle
Some scientists say that we may be on the edge of yet another such turning point as the world's biggest atom smasher, the Large Hadron Collider (LHC), gears up to search for a theoretical sub-atomic particle that could explain how matter acquires mass.
Dark matter and dark energy, deemed to account for 96% of the cosmos are other theorised puzzles. If the LHC answers them, it could once again throw science into a period of fruitful crisis before a new consensus emerges.
German nuclear physicist Max Planck understood that old theories die hard. "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die," he wrote.
Story on this link
http://www.cosmosmagazine.com/news/3094/how-galileos-spy-glass-upended-science?page=0,0
PARIS: It would hardly pass as a toy today, but the telescope Galileo used 400 years ago this week, overturned the foundations of knowledge, changing our perception of the universe and our place within it.
Galileo's 'optick tube' magnified a meagre nine-fold and was not even conceived of for astronomy.
Nevertheless, when the gadget was first demonstrated, Venetian senators were so smitten with its military potential that they doubled Galileo's salary and awarded him life tenure in the city-state's most prestigious university.
Paradigm shift
But when, in late October 1609, the 45-year-old Italian mathematician pointed his newfangled instrument - essentially two lenses aligned in a tube - skyward, what he glimpsed would unleash a scientific revolution and a rare paradigm shift in thought.
"He immediately made several surprising discoveries that contributed to the demise of the Earth-centred cosmology that had dominated Western thought for two millennia," says Robert Joseph, an astronomy at the University of Hawaii in Honolulu.
Using ever-more powerful telescopes over the next year, Galileo observed that the Moon was not perfectly smooth as claimed by Aristotle but cratered and mountainous.
He spotted hundreds of stars never seen before.
Galilean moons
More critically, he discovered the four inner satellites of Jupiter - still known as the "Galilean moons" today, in his honour - and learnt that Venus, Earth's closest planet, goes through a full range of phases.
Put together, his observations validated the revolutionary theory of Nicolaus Copernicus that Earth orbits the Sun, and not the other way round.
Galileo understood the implications of what he had seen, but the Catholic Church was not ready to accept such heresy. Only in 2000 did the Holy See apologise for putting Galileo on trial in 1633, forcing him to recant his ideas lest he face imprisonment or worse. The Vatican also paid tribute to him in an exhibition that opened this month.
But resistance to a solar-centric view was not only religious. The ancient Greek notion that Earth was at the centre of the cosmos was also a deeply ingrained scientific dogma, and it took decades to dislodge it.
Even the notion that "we can improve on our senses" by magnifying our vision was considered taboo, says Jerome Lamy, a science historian at the Paris Observatory in France.
Scientific revolution
The concept of paradigm shifts was first articulated by U.S. philosopher Thomas Kuhn in a 1962 book, "The Structure of Scientific Revolutions". A sea change in thinking entails not only the overturning of a theory but the creation of an entirely new world view, he said.
It happened again at the start of the 20th century, only a few years after Scottish mathematician Lord Kelvin had famously declared there was "nothing new" to be discovered in physics.
That seismic shift came in the form of a short paper on special relativity by a German-born patent clerk by the name of Albert Einstein.
Again, it did not happen overnight. But Einstein's ideas eventually toppled laws of physics that had prevailed for three centuries.
The God particle
Some scientists say that we may be on the edge of yet another such turning point as the world's biggest atom smasher, the Large Hadron Collider (LHC), gears up to search for a theoretical sub-atomic particle that could explain how matter acquires mass.
Dark matter and dark energy, deemed to account for 96% of the cosmos are other theorised puzzles. If the LHC answers them, it could once again throw science into a period of fruitful crisis before a new consensus emerges.
German nuclear physicist Max Planck understood that old theories die hard. "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die," he wrote.
Story on this link
http://www.cosmosmagazine.com/news/3094/how-galileos-spy-glass-upended-science?page=0,0
Tuesday, October 27, 2009
Why Fat Lubricates Your Appetite
By Frederik Joelving
When you've spent the weekend splurging on greasy fast foods, your bathroom scale isn't alone in reeling from the impact. Your brain does, too. New research shows just how saturated fat tricks us into eating more and elucidates the evolutionary basis for the propensity for poundage in developed nations. Our brain physiology, it seems, is glaringly out-of-date in the modern world.
Researchers have long known that the hormones leptin and insulin play key roles in appetite and food intake. In healthy people leptin, which is secreted by fat tissue, acts as a molecular measuring tape for our waistlines, quashing feelings of hunger. Insulin spikes when the pancreas gets a whiff of the blood sugar increase after a meal; once the brain detects the spike, it knows to tamp down the desire for food.
Certain foods and metabolic disorders, however, can disrupt our ability to respond appropriately to these hormonal signals. In a study published in the September issue of The Journal of Clinical Investigation, scientists report unraveling a central biochemical mechanism behind fat's effect on the mammalian brain . They found that after only three days on a diet high in saturated fat—a common ingredient in beef and cheese—the brains of rats and mice became resistant to leptin and insulin. In contrast, unsaturated fats, such as those found in olive oil, did not trigger resistance.
As a result of the hormone resistance, a meal high in saturated fat can crank up our appetite well after dessert. "Taking time off from a healthy diet to eat most fast foods may have consequences that last for some days, even after one resumes the healthy diet," says University of Cincinnati behavioral neuroscientist Stephen Benoit, who led the study. He believes the findings are likely to apply to humans, too.
Sensing leptin and insulin is like keeping an eye on the body's nutrient status, says Gary Schwartz, a neuroscientist at the Albert Einstein College of Medicine in New York City, who was not involved in the research. "If that eye starts to go blind because you keep giving it too much nutrient, then it can't respond. It can't tell you, 'look, don't eat.'" The result can spark a vicious cycle of metabolic problems and weight gain, he remarks.
But if the hormones are supposed to keep our metabolism from spinning out of control, why would saturated fat—the very thing that obese people have too much of—make us insensitive to them?
"There is a basic mystery here," says William Banks of the Saint Louis Veterans Affairs Medical Center. A leptin expert, he has shown that high levels of saturated fat in the bloodstream block the hormone's passage into the brain, further blinding it to those extra pounds below the neck.
One hint at an explanation for these counterintuitive effects comes from the physiology of starvation. When we starve, our body begins to break down its blubber for energy. As a result, the blood gets flooded with fat, just as it does in obesity and overeating. Apparently erring on the side of caution, our brain interprets free fat (no matter its source) as a starvation alert—had it done otherwise in our evolutionary history, we probably wouldn't be around to worry about it. Says Banks: "In the history of evolution, we've been faced with caloric shortages and starvation much more than we've ever been faced with a wealth of calories."
Read more at http://www.scientificamerican.com/article.cfm?id=lard-lesson-why-fat-lubri
When you've spent the weekend splurging on greasy fast foods, your bathroom scale isn't alone in reeling from the impact. Your brain does, too. New research shows just how saturated fat tricks us into eating more and elucidates the evolutionary basis for the propensity for poundage in developed nations. Our brain physiology, it seems, is glaringly out-of-date in the modern world.
Researchers have long known that the hormones leptin and insulin play key roles in appetite and food intake. In healthy people leptin, which is secreted by fat tissue, acts as a molecular measuring tape for our waistlines, quashing feelings of hunger. Insulin spikes when the pancreas gets a whiff of the blood sugar increase after a meal; once the brain detects the spike, it knows to tamp down the desire for food.
Certain foods and metabolic disorders, however, can disrupt our ability to respond appropriately to these hormonal signals. In a study published in the September issue of The Journal of Clinical Investigation, scientists report unraveling a central biochemical mechanism behind fat's effect on the mammalian brain . They found that after only three days on a diet high in saturated fat—a common ingredient in beef and cheese—the brains of rats and mice became resistant to leptin and insulin. In contrast, unsaturated fats, such as those found in olive oil, did not trigger resistance.
As a result of the hormone resistance, a meal high in saturated fat can crank up our appetite well after dessert. "Taking time off from a healthy diet to eat most fast foods may have consequences that last for some days, even after one resumes the healthy diet," says University of Cincinnati behavioral neuroscientist Stephen Benoit, who led the study. He believes the findings are likely to apply to humans, too.
Sensing leptin and insulin is like keeping an eye on the body's nutrient status, says Gary Schwartz, a neuroscientist at the Albert Einstein College of Medicine in New York City, who was not involved in the research. "If that eye starts to go blind because you keep giving it too much nutrient, then it can't respond. It can't tell you, 'look, don't eat.'" The result can spark a vicious cycle of metabolic problems and weight gain, he remarks.
But if the hormones are supposed to keep our metabolism from spinning out of control, why would saturated fat—the very thing that obese people have too much of—make us insensitive to them?
"There is a basic mystery here," says William Banks of the Saint Louis Veterans Affairs Medical Center. A leptin expert, he has shown that high levels of saturated fat in the bloodstream block the hormone's passage into the brain, further blinding it to those extra pounds below the neck.
One hint at an explanation for these counterintuitive effects comes from the physiology of starvation. When we starve, our body begins to break down its blubber for energy. As a result, the blood gets flooded with fat, just as it does in obesity and overeating. Apparently erring on the side of caution, our brain interprets free fat (no matter its source) as a starvation alert—had it done otherwise in our evolutionary history, we probably wouldn't be around to worry about it. Says Banks: "In the history of evolution, we've been faced with caloric shortages and starvation much more than we've ever been faced with a wealth of calories."
Read more at http://www.scientificamerican.com/article.cfm?id=lard-lesson-why-fat-lubri
Cosmic pattern to UK tree growth
By Matt Walker
Editor, Earth News
The growth of British trees appears to follow a cosmic pattern, with trees growing faster when high levels of cosmic radiation arrive from space.
Researchers made the discovery studying how growth rings of spruce trees have varied over the past half a century.
As yet, they cannot explain the pattern, but variation in cosmic rays impacted tree growth more than changes in temperature or precipitation.
The study is published in the scientific journal New Phytologist.
"We were originally interested in a different topic, the climatological factors influencing forest growth," says Ms Sigrid Dengel a postgraduate researcher at the Institute of Atmospheric and Environmental Science at the University of Edinburgh.
More on this at http://news.bbc.co.uk/earth/hi/earth_news/newsid_8311000/8311373.stm
Editor, Earth News
The growth of British trees appears to follow a cosmic pattern, with trees growing faster when high levels of cosmic radiation arrive from space.
Researchers made the discovery studying how growth rings of spruce trees have varied over the past half a century.
As yet, they cannot explain the pattern, but variation in cosmic rays impacted tree growth more than changes in temperature or precipitation.
The study is published in the scientific journal New Phytologist.
"We were originally interested in a different topic, the climatological factors influencing forest growth," says Ms Sigrid Dengel a postgraduate researcher at the Institute of Atmospheric and Environmental Science at the University of Edinburgh.
More on this at http://news.bbc.co.uk/earth/hi/earth_news/newsid_8311000/8311373.stm
Biofuels 'worse than petrol' for climate
Gerard Wynn and Timothy Gardner
Reuters
A new generation of biofuels, meant to be a low-carbon alternative, will on average emit more carbon dioxide over the next few decades than burning petrol, according to a new study.
Governments and companies are pouring billions of research dollars into advanced fuels made from wood and grass, meant to cut carbon emissions compared with petrol.
But according to the study appearing in today's edition of Science, advanced 'cellulosic' biofuels will actually lead to higher carbon emissions than petrol per unit of energy, averaged over the 2000-2030 time period.
That is because the land required to plant fast-growing poplar trees and tropical grasses will displace food crops, and so drive deforestation to create more farmland, a powerful source of carbon emissions.
Biofuel crops also require nitrogen fertilisers, a source of two greenhouse gases: carbon dioxide (CO2) and the more powerful nitrous oxide.
"In the near-term, irrespective of how you go about the cellulosic biofuels program, you're going to have greenhouse gas emissions exacerbating the climate change problem," says lead author Dr Jerry Melillo of the US Marine Biological Laboratory.
Read more at http://www.abc.net.au/science/articles/2009/10/23/2722259.htm
Reuters
A new generation of biofuels, meant to be a low-carbon alternative, will on average emit more carbon dioxide over the next few decades than burning petrol, according to a new study.
Governments and companies are pouring billions of research dollars into advanced fuels made from wood and grass, meant to cut carbon emissions compared with petrol.
But according to the study appearing in today's edition of Science, advanced 'cellulosic' biofuels will actually lead to higher carbon emissions than petrol per unit of energy, averaged over the 2000-2030 time period.
That is because the land required to plant fast-growing poplar trees and tropical grasses will displace food crops, and so drive deforestation to create more farmland, a powerful source of carbon emissions.
Biofuel crops also require nitrogen fertilisers, a source of two greenhouse gases: carbon dioxide (CO2) and the more powerful nitrous oxide.
"In the near-term, irrespective of how you go about the cellulosic biofuels program, you're going to have greenhouse gas emissions exacerbating the climate change problem," says lead author Dr Jerry Melillo of the US Marine Biological Laboratory.
Read more at http://www.abc.net.au/science/articles/2009/10/23/2722259.htm
Mouse
No Not the mouse used with a computer. This is the real mouse known as the house which eats anything to everything. They are mainly active at night and live mainly on the ground. Mouses are good climbers as well as swimmers. It relies on its senses of smell and hearing rather than sight to find its way around. It uses nose to track down food and to follow scent paths.
A pair of mice can give birth to 30 or 40 babies a year, even more if food is plentiful.
Many people consider mice to be pests because they destroy food supplies and every carry disease. Mice have played a role in spreading typhus, spotted fever, salmonella, and the bubonic plague. Also they have been used in scientific experiments.
A pair of mice can give birth to 30 or 40 babies a year, even more if food is plentiful.
Many people consider mice to be pests because they destroy food supplies and every carry disease. Mice have played a role in spreading typhus, spotted fever, salmonella, and the bubonic plague. Also they have been used in scientific experiments.
Monday, October 26, 2009
Gecko
The small lizards known as geckos are fun to watch as they move about. Geckos are great climbers because their feet stick to many surfaces. Each of its long, flat toes has thousands of tiny hairs. At the end of each tiny hair are hundreds of even smaller hairs. These hairs fan out to create a strong sticking power that lets the gecko move along areas where many other animals would slip. Geckos usually come out at night and feed on insects.
Some people keep geckos as pets. One of the most popular is the large tokay gecko, which is gray with red and whitish spots and bands. It is possible that a gecko may live 20 or more years when kept by people.
Some people keep geckos as pets. One of the most popular is the large tokay gecko, which is gray with red and whitish spots and bands. It is possible that a gecko may live 20 or more years when kept by people.
Tuesday, October 20, 2009
Marsupial
Kangaroos, koalas, and opossums—these unique animals are all marsupials. Marsupials are known for carrying their young in a special pouch. The name marsupial comes from the Latin word marsupium, which means “pouch.”
The largest living marsupials are the red and gray kangaroos of Australia.Some marsupials are carnivores, or meat eaters. For example, the Tasmanian devil feeds on birds, small mammals, and dead animals.
The largest living marsupials are the red and gray kangaroos of Australia.Some marsupials are carnivores, or meat eaters. For example, the Tasmanian devil feeds on birds, small mammals, and dead animals.
Thursday, October 15, 2009
Bears
Bears are found in North America, Europe, and Asia. One species lives in South America. However, there are no bears in tropical Africa.
The polar bear lives mostly in the Arctic north, where its white fur blends in with snow and ice. Polar bears are often seen on drifting masses of floating sea ice called floes. Brown bears, once widespread in Europe and Asia, are now rare. The grizzly bear, a brown bear of northern and western North America, has been killed off in many areas. The Kodiak bear, an Alaskan island bear closely related to the grizzly, is the world's largest living flesh-eating land mammal.
The American black bear is smaller than the brown bears. It still ranges widely in the forests of the United States and Canada. There is also an Asian, or Himalayan black bear. Most bears live in cold or temperate climates, but the sloth bear is a creature of the tropics. It lives in India and Sri Lanka. The sun bear, or Malayan sun bear, lives in the forests of Southeast Asia. The spectacled bear, which gets its name from the light-colored rings around its eyes, is the only bear of the Southern Hemisphere. It is found in the Andes Mountains of Chile, Bolivia, Ecuador, and Peru.
Bears are solitary creatures that avoid each other except in the mating season. Female bears give birth to one to four cubs at a time, usually in winter. Newborn cubs are small, hairless, and helpless creatures unable to open their eyes for about a week. Cubs drink their mother's milk for about two months and stay with her until the next breeding period begins, which is usually about a year and a half after their birth. Bears begin to breed at 2 to 6 years of age. The male bear plays no role in raising the cubs. Most bears live from 15 to 30 years in the wild. Captive bears have lived much longer.
The polar bear lives mostly in the Arctic north, where its white fur blends in with snow and ice. Polar bears are often seen on drifting masses of floating sea ice called floes. Brown bears, once widespread in Europe and Asia, are now rare. The grizzly bear, a brown bear of northern and western North America, has been killed off in many areas. The Kodiak bear, an Alaskan island bear closely related to the grizzly, is the world's largest living flesh-eating land mammal.
The American black bear is smaller than the brown bears. It still ranges widely in the forests of the United States and Canada. There is also an Asian, or Himalayan black bear. Most bears live in cold or temperate climates, but the sloth bear is a creature of the tropics. It lives in India and Sri Lanka. The sun bear, or Malayan sun bear, lives in the forests of Southeast Asia. The spectacled bear, which gets its name from the light-colored rings around its eyes, is the only bear of the Southern Hemisphere. It is found in the Andes Mountains of Chile, Bolivia, Ecuador, and Peru.
Bears are solitary creatures that avoid each other except in the mating season. Female bears give birth to one to four cubs at a time, usually in winter. Newborn cubs are small, hairless, and helpless creatures unable to open their eyes for about a week. Cubs drink their mother's milk for about two months and stay with her until the next breeding period begins, which is usually about a year and a half after their birth. Bears begin to breed at 2 to 6 years of age. The male bear plays no role in raising the cubs. Most bears live from 15 to 30 years in the wild. Captive bears have lived much longer.
Wednesday, October 14, 2009
Aardvark
The unusual mammal called the aardvark was named by South Africans in the early 19th century. In the local language, Afrikaans, “aardvark” means “earth pig.” This name aptly describes a large, heavily built animal with thin hair and short, stumpy legs. The aardvark can reach a length of 6 feet (1.8 meters). Its head has huge donkeylike ears, a long snout, and drooping eyelids with long lashes.
Aardvarks, which are also called ant bears, live in dry places in Africa south of the Sahara Desert. During the day they sleep in underground burrows. At night they dig underground for their favorite food, termites. Aardvarks use their sensitive snouts to detect these insects. They break open the termites' nests with their massive, flattened claws and suck up the insects with their long tongues. Although they are not aggressive animals, aardvarks can defend themselves by lashing out with their claws. They can also dig very quickly to bury themselves.
Female aardvarks give birth to one baby per year. After a few weeks the baby begins to follow its mother around. It feeds and travels with her for about six months until it becomes more independent.
Saturday, June 13, 2009
Flowering plants and hippo-like creatures once thrived in the Arctic's warm, humid summers and mild winters
By Andrea Thompson
Flowering plants and hippo-like creatures once thrived in the Arctic, where the tundra and polar bears now prevail.
New research, detailed in the June issue of the journal Geology, is shedding light on the lives of prehistoric mammals on Canada's Ellesmere Island 53 million years ago, including how they survived the six months of darkness during the Arctic winter.
Today, Ellesmere Island, located in the high Arctic (about 80 degrees north latitude), is a polar desert that features permafrost, ice sheets, sparse vegetation and a few mammals. Temperatures there range from minus 37 degrees Fahrenheit (-38 Celsius) in winter to plus 48 degrees F (9 Celsius) in summer. It is one of the coldest and driest places on Earth.
Click here for the complete story
Flowering plants and hippo-like creatures once thrived in the Arctic, where the tundra and polar bears now prevail.
New research, detailed in the June issue of the journal Geology, is shedding light on the lives of prehistoric mammals on Canada's Ellesmere Island 53 million years ago, including how they survived the six months of darkness during the Arctic winter.
Today, Ellesmere Island, located in the high Arctic (about 80 degrees north latitude), is a polar desert that features permafrost, ice sheets, sparse vegetation and a few mammals. Temperatures there range from minus 37 degrees Fahrenheit (-38 Celsius) in winter to plus 48 degrees F (9 Celsius) in summer. It is one of the coldest and driest places on Earth.
Click here for the complete story
There is growing evidence that expensive angioplasties are no better than drugs alone in saving lives
By John Carey
There's a powerful logic to the argument that people will live longer and have fewer heart attacks if their clogged arteries are repaired with a procedure called angioplasty. Most commonly, the arteries are widened with a tiny balloon threaded through their blood vessels, then kept open with slender mesh tubes called stents. The logic has turned this medical procedure into a huge—and profitable—business. Each year in the U.S., more than 1.2 million angioplasties are performed, at a cost of more than $25 billion. The cardiologists who open arteries love the sense that they are warding off death, and patients "think the angioplasty saved their lives," says Floyd J. Fowler Jr., president of the Foundation for Informed Medical Decision Making.
But the data show that doctors and patients are wrong. Several recent studies have found that angioplasty doesn't save lives or prevent heart attacks in patients with stable heart disease compared to treatment with drugs. And now, in a study presented at the American Diabetes Assn. meeting on June 7 (and published in the June 11 issue of The New England Journal of Medicine), the limitations of angioplasty are evident even when the procedures were performed on diabetics with heart disease. For those patients, "medical therapy [the use of drugs] rather than any intervention is an excellent first-line strategy," conclude Dr. William E. Boden of the State University of New York at Buffalo and Oxford University's Dr. David P. Taggart in an NEJM editorial.
The new study, which is certain to be pulled into the national debate about how to reduce health-care costs, offers important new insights about which cardiovascular therapies are most effective. In contrast with some previous clinical trials, a large number of the patients undergoing angioplasty received high-tech drug-eluting stents of the sort sold by Johnson & Johnson (JNJ), Medtronic (MDT), and others, which doctors had hoped would offer better outcomes than the older, plain-metal variety. And the study focused on diabetics, many of whom also have heart disease. "We began the study because we don't know how best to treat this deadly duo that is affecting more and more people," explains Sheryl F. Kelsey, a professor of epidemiology at the University of Pittsburgh Graduate School of Public Health and principal investigator of the study. "We were thinking that maybe for this group, revascularization [angioplasty] would be better than medical therapy."
It wasn't. There were no differences in deaths or events like heart attacks between the 798 diabetics who got drugs only and the 807 patients who had their arteries opened in addition to getting the same drugs.
Click here for original story
There's a powerful logic to the argument that people will live longer and have fewer heart attacks if their clogged arteries are repaired with a procedure called angioplasty. Most commonly, the arteries are widened with a tiny balloon threaded through their blood vessels, then kept open with slender mesh tubes called stents. The logic has turned this medical procedure into a huge—and profitable—business. Each year in the U.S., more than 1.2 million angioplasties are performed, at a cost of more than $25 billion. The cardiologists who open arteries love the sense that they are warding off death, and patients "think the angioplasty saved their lives," says Floyd J. Fowler Jr., president of the Foundation for Informed Medical Decision Making.
But the data show that doctors and patients are wrong. Several recent studies have found that angioplasty doesn't save lives or prevent heart attacks in patients with stable heart disease compared to treatment with drugs. And now, in a study presented at the American Diabetes Assn. meeting on June 7 (and published in the June 11 issue of The New England Journal of Medicine), the limitations of angioplasty are evident even when the procedures were performed on diabetics with heart disease. For those patients, "medical therapy [the use of drugs] rather than any intervention is an excellent first-line strategy," conclude Dr. William E. Boden of the State University of New York at Buffalo and Oxford University's Dr. David P. Taggart in an NEJM editorial.
The new study, which is certain to be pulled into the national debate about how to reduce health-care costs, offers important new insights about which cardiovascular therapies are most effective. In contrast with some previous clinical trials, a large number of the patients undergoing angioplasty received high-tech drug-eluting stents of the sort sold by Johnson & Johnson (JNJ), Medtronic (MDT), and others, which doctors had hoped would offer better outcomes than the older, plain-metal variety. And the study focused on diabetics, many of whom also have heart disease. "We began the study because we don't know how best to treat this deadly duo that is affecting more and more people," explains Sheryl F. Kelsey, a professor of epidemiology at the University of Pittsburgh Graduate School of Public Health and principal investigator of the study. "We were thinking that maybe for this group, revascularization [angioplasty] would be better than medical therapy."
It wasn't. There were no differences in deaths or events like heart attacks between the 798 diabetics who got drugs only and the 807 patients who had their arteries opened in addition to getting the same drugs.
Click here for original story
Trains have much higher greenhouse gas emissions than airplanes
A new study has suggested that greenhouse gas emissions generated by trains are much higher than those produced by an airplane.
Unlike previous studies on transport emissions, this one looks beyond what is emitted by different types of car, train, bus or plane while their engines are running and includes emissions from building and maintaining the vehicles and their infrastructure, as well as generating the fuel to run them.
Including these additional sources of pollution more than doubles the greenhouse gas emissions of train travel.
The emissions generated by car travel increase by nearly one third when manufacturing and infrastructure are taken into account.
In comparison to cars on roads and trains on tracks, air travel requires little infrastructure. As a result, full life-cycle emissions are between 10 and 20 per cent higher than “tailpipe” emissions.
According to a report in New Scientist, Mikhail Chester and Arpad Horvath of the University of California, Berkeley, included in their calculations data on the “life expectancy” of each component of each mode of transportation, such as the tracks used by a train and the airports used by aircraft.
They calculated the total “travel kilometers” each component allows and how many tonnes of greenhouse gases were emitted to build and maintain each component.
This allowed them to calculate the component’s emissions per kilometre travelled, for each mode of transport per kilometre for each traveller on board.
Cars emitted more than any other form of transport with the notable exception of off-peak buses, which often carry few passengers.
Passengers on the Boston light rail, an electric commuter train, were found to emit as much or marginally more than those on mid-size and large aircraft. This is because burning fossil fuels generates 82 per cent of electricity in Massachusetts.
More than half of the life-cycle emissions from rail come not from the engines’ exhausts, but infrastructure development, such as station building and track laying, and providing power to stations, lit parking lots and escalators.
“Any government considering expanding its rail network should take into account the emissions it will generate in doing so,” Chester said.
“New rail systems should serve as links to other transit modes, as is often the case in Europe and Japan,” he added.
“We should avoid building rail systems that are disconnected from major population areas and require car trips and parking to access,” he explained.
ANI
Click here for original story
Unlike previous studies on transport emissions, this one looks beyond what is emitted by different types of car, train, bus or plane while their engines are running and includes emissions from building and maintaining the vehicles and their infrastructure, as well as generating the fuel to run them.
Including these additional sources of pollution more than doubles the greenhouse gas emissions of train travel.
The emissions generated by car travel increase by nearly one third when manufacturing and infrastructure are taken into account.
In comparison to cars on roads and trains on tracks, air travel requires little infrastructure. As a result, full life-cycle emissions are between 10 and 20 per cent higher than “tailpipe” emissions.
According to a report in New Scientist, Mikhail Chester and Arpad Horvath of the University of California, Berkeley, included in their calculations data on the “life expectancy” of each component of each mode of transportation, such as the tracks used by a train and the airports used by aircraft.
They calculated the total “travel kilometers” each component allows and how many tonnes of greenhouse gases were emitted to build and maintain each component.
This allowed them to calculate the component’s emissions per kilometre travelled, for each mode of transport per kilometre for each traveller on board.
Cars emitted more than any other form of transport with the notable exception of off-peak buses, which often carry few passengers.
Passengers on the Boston light rail, an electric commuter train, were found to emit as much or marginally more than those on mid-size and large aircraft. This is because burning fossil fuels generates 82 per cent of electricity in Massachusetts.
More than half of the life-cycle emissions from rail come not from the engines’ exhausts, but infrastructure development, such as station building and track laying, and providing power to stations, lit parking lots and escalators.
“Any government considering expanding its rail network should take into account the emissions it will generate in doing so,” Chester said.
“New rail systems should serve as links to other transit modes, as is often the case in Europe and Japan,” he added.
“We should avoid building rail systems that are disconnected from major population areas and require car trips and parking to access,” he explained.
ANI
Click here for original story
The New Moon Race looks to determine what China - and other nations - are planning to do with the Moon
by Morris Jones
Rosenberg Publishing, 2009
Hardcover, 184 pp., illus.
ISBN 978-1-877058-82-0
US$49.95
One of the arguments advocates of NASA’s exploration vision have used in recent years could be summarized as thus: “The Chinese are coming!” Or, perhaps a bit more accurately: “The Chinese are going—to the Moon!” Citing the growing capabilities of China’s space program, as well as the occasionally confusing, if not downright contradictory, statements by Chinese officials, space supporters in the US have warned that China could send humans to the Moon before the end of the next decade, and even before NASA returns under current exploration plans. Even former NASA administrator Mike Griffin, on a number of occasions while in office, believed that China would beat the US back to the Moon. “I will be surprised if the United States is back on the Moon before China is on the Moon,” he said in one early 2008 speech (see “Defending Constellation”, The Space Review, February 4, 2008).
Click here to read the original story
Rosenberg Publishing, 2009
Hardcover, 184 pp., illus.
ISBN 978-1-877058-82-0
US$49.95
One of the arguments advocates of NASA’s exploration vision have used in recent years could be summarized as thus: “The Chinese are coming!” Or, perhaps a bit more accurately: “The Chinese are going—to the Moon!” Citing the growing capabilities of China’s space program, as well as the occasionally confusing, if not downright contradictory, statements by Chinese officials, space supporters in the US have warned that China could send humans to the Moon before the end of the next decade, and even before NASA returns under current exploration plans. Even former NASA administrator Mike Griffin, on a number of occasions while in office, believed that China would beat the US back to the Moon. “I will be surprised if the United States is back on the Moon before China is on the Moon,” he said in one early 2008 speech (see “Defending Constellation”, The Space Review, February 4, 2008).
Click here to read the original story
A massive bombardment of meteorites billions of years ago could have brought in enough water and carbon dioxide to jump-start life on Earth
By John Johnson Jr.
A massive bombardment of meteorites billions of years ago could have brought in enough water and carbon dioxide to jump-start the chemistry that let the Earth develop into the garden spot of our solar system.
By studying meteorites and other evidence from this bombardment, a team of researchers at Imperial College in England has calculated that the meteorites could have carried in as much as 10 billion tons of water vapor and carbon dioxide to the young Earth every year for millions of years.
That amount of water and carbon dioxide would have been enough to set off a greenhouse effect that eventually made the Earth warm and wet enough to harbor plants and creatures.
This isn't the first time scientists have theorized that the ingredients for life on Earth could have been delivered. Comets and asteroids both have been proposed as carriers of water as well as organic compounds to Earth.
What distinguishes the new research, published in the earth and planetary science journal Geochimica et Cosmochimica Acta, is its suggestion of when and how the Earth received its shipment of life-giving material.
"The amount delivered in this bombardment alone was enough to kick-start the Earth on its way to habitability," study co-author Richard Court, an Imperial College London professor of Earth science and engineering, said in an e-mail message.
The incident at the heart of the study is known as the Late Heavy Bombardment, a time about 4 billion years ago, not long after the Earth was formed from the dust and debris swirling around the young sun. According to the scientists, the Late Heavy Bombardment lasted 20 million years and rained millions of space rocks onto the Earth, moon and Mars.
Because of the Earth's rapidly changing geology, evidence of this event was mostly lost, except for the leftover meteorites themselves. But the moon, with no atmosphere, has little erosion, allowing closer study of the bombardment period's effects on the lunar surface. Court said that at least 6,000 craters greater than 14 miles across remain from this period. On Earth, the bombardment might have produced 22,000 of these huge craters, he said.
According to the scientists' theory, the frictional heat of passing through the thin atmosphere that surrounded the Earth at that time would have been enough to strip the oxygen- and water-rich outer layers from the meteorites as they plunged toward the planet. That process would slowly have caused a buildup of oxygen and water in the atmosphere.
To find out how much of those critical compounds could be carried by each meteorite, the team used samples of ancient rocks left over from the bombardment, flash-heating them in the absence of oxygen to prevent combustion. The gases given off during the heating process were then measured.
The team found that, on average, the meteorites gave off as much as 12% of their masses as water and 6% as carbon dioxide, a potent greenhouse gas whose greater concentration in the atmosphere today is causing world temperatures to rise.
The atmosphere of the early Earth was so thin that it needed a lot of greenhouse gas to reach the point that it was thick enough to trap the sun's heat, allowing the Earth's surface to warm up and water to remain in liquid form over much of the planet.
Paul Warren, a planetary scientist at UCLA, said he was impressed by the British team's efforts to try to quantify the amount of water that could have been delivered by the Late Heavy Bombardment. But he said he's not convinced this one event could account for all the water on Earth.
He also said that far from giving life a running start, the bombardment could just as easily have caused "catastrophic heating" of the young planet's atmosphere.
"It actually could be an impediment to life," Warren said.
The British researchers believe Mars experienced the same unrelenting bombardment as the Earth. The Martian rovers Spirit and Opportunity have uncovered evidence that the Red Planet once featured standing seas and relatively mild weather. That ended billions of years ago. The Imperial College team believes the key difference between the planets' fates is the Earth's molten iron core, which allowed our planet to develop a magnetic field. That magnetic field prevents most harmful solar radiation from damaging the atmosphere.
Mars lost its magnetic shield long ago, allowing the atmosphere to be worn away by the sun's relentless radiation. Slowing of volcanic activity also cooled the planet, causing the water to retreat underground at the poles
Click here to read the original story
A massive bombardment of meteorites billions of years ago could have brought in enough water and carbon dioxide to jump-start the chemistry that let the Earth develop into the garden spot of our solar system.
By studying meteorites and other evidence from this bombardment, a team of researchers at Imperial College in England has calculated that the meteorites could have carried in as much as 10 billion tons of water vapor and carbon dioxide to the young Earth every year for millions of years.
That amount of water and carbon dioxide would have been enough to set off a greenhouse effect that eventually made the Earth warm and wet enough to harbor plants and creatures.
This isn't the first time scientists have theorized that the ingredients for life on Earth could have been delivered. Comets and asteroids both have been proposed as carriers of water as well as organic compounds to Earth.
What distinguishes the new research, published in the earth and planetary science journal Geochimica et Cosmochimica Acta, is its suggestion of when and how the Earth received its shipment of life-giving material.
"The amount delivered in this bombardment alone was enough to kick-start the Earth on its way to habitability," study co-author Richard Court, an Imperial College London professor of Earth science and engineering, said in an e-mail message.
The incident at the heart of the study is known as the Late Heavy Bombardment, a time about 4 billion years ago, not long after the Earth was formed from the dust and debris swirling around the young sun. According to the scientists, the Late Heavy Bombardment lasted 20 million years and rained millions of space rocks onto the Earth, moon and Mars.
Because of the Earth's rapidly changing geology, evidence of this event was mostly lost, except for the leftover meteorites themselves. But the moon, with no atmosphere, has little erosion, allowing closer study of the bombardment period's effects on the lunar surface. Court said that at least 6,000 craters greater than 14 miles across remain from this period. On Earth, the bombardment might have produced 22,000 of these huge craters, he said.
According to the scientists' theory, the frictional heat of passing through the thin atmosphere that surrounded the Earth at that time would have been enough to strip the oxygen- and water-rich outer layers from the meteorites as they plunged toward the planet. That process would slowly have caused a buildup of oxygen and water in the atmosphere.
To find out how much of those critical compounds could be carried by each meteorite, the team used samples of ancient rocks left over from the bombardment, flash-heating them in the absence of oxygen to prevent combustion. The gases given off during the heating process were then measured.
The team found that, on average, the meteorites gave off as much as 12% of their masses as water and 6% as carbon dioxide, a potent greenhouse gas whose greater concentration in the atmosphere today is causing world temperatures to rise.
The atmosphere of the early Earth was so thin that it needed a lot of greenhouse gas to reach the point that it was thick enough to trap the sun's heat, allowing the Earth's surface to warm up and water to remain in liquid form over much of the planet.
Paul Warren, a planetary scientist at UCLA, said he was impressed by the British team's efforts to try to quantify the amount of water that could have been delivered by the Late Heavy Bombardment. But he said he's not convinced this one event could account for all the water on Earth.
He also said that far from giving life a running start, the bombardment could just as easily have caused "catastrophic heating" of the young planet's atmosphere.
"It actually could be an impediment to life," Warren said.
The British researchers believe Mars experienced the same unrelenting bombardment as the Earth. The Martian rovers Spirit and Opportunity have uncovered evidence that the Red Planet once featured standing seas and relatively mild weather. That ended billions of years ago. The Imperial College team believes the key difference between the planets' fates is the Earth's molten iron core, which allowed our planet to develop a magnetic field. That magnetic field prevents most harmful solar radiation from damaging the atmosphere.
Mars lost its magnetic shield long ago, allowing the atmosphere to be worn away by the sun's relentless radiation. Slowing of volcanic activity also cooled the planet, causing the water to retreat underground at the poles
Click here to read the original story
Thursday, June 4, 2009
Now, a cancer drug that won't cause hair loss!
Washington (PTI): Researchers have developed a way to deliver cancer drugs, which they claim will not cause the usual sickness and hair loss -- by just using a fat-rich coating.
Until now, treatment of cancer has relied mainly on surgery, radiotherapy or chemotherapy. Though these strategies have benefited millions of cancer patients to date, the lack of tumour specificity of some of these agents make patients feel sick or result in significant hair loss.
Now, an international team, led by Queensland University, has developed the way which can specifically shut down cancer-causing genes in tumour cells while sparing normal healthy tissues.
According to lead researcher Sherry Wu, the new method which involves the use of coatings rich in fats, will hasten the application of RNA interference or gene-silencing, a technology which can inactivate individual genes.
Using this technology, the team observed a 70 per cent reduction in tumour size in a cervical cancer mouse model.
"The traditional ways of packaging these drugs into suitable carriers are often complex and labour-intensive. The resulting products are also unstable at room temperature which is obviously not ideal for their clinical use.
"In order to deliver these gene-silencing drugs safely and efficiently into tumour tissues in the body, we have to package them in lipid-rich carriers," Wu said.
Added co-researcher Nigel McMillan: "We are excited about our findings and we are currently investigating the feasibility of combining this gene-silencing technology with low dose chemotherapeutic agents in cancer treatments."
Until now, treatment of cancer has relied mainly on surgery, radiotherapy or chemotherapy. Though these strategies have benefited millions of cancer patients to date, the lack of tumour specificity of some of these agents make patients feel sick or result in significant hair loss.
Now, an international team, led by Queensland University, has developed the way which can specifically shut down cancer-causing genes in tumour cells while sparing normal healthy tissues.
According to lead researcher Sherry Wu, the new method which involves the use of coatings rich in fats, will hasten the application of RNA interference or gene-silencing, a technology which can inactivate individual genes.
Using this technology, the team observed a 70 per cent reduction in tumour size in a cervical cancer mouse model.
"The traditional ways of packaging these drugs into suitable carriers are often complex and labour-intensive. The resulting products are also unstable at room temperature which is obviously not ideal for their clinical use.
"In order to deliver these gene-silencing drugs safely and efficiently into tumour tissues in the body, we have to package them in lipid-rich carriers," Wu said.
Added co-researcher Nigel McMillan: "We are excited about our findings and we are currently investigating the feasibility of combining this gene-silencing technology with low dose chemotherapeutic agents in cancer treatments."
Solar thermal power could generate up to a quarter of the world's electricity by 2050
Solar thermal power has the potential to generate up to a quarter of the world's electricity by 2050, according to a new report by pro-solar groups.
The study, by Greenpeace, the European Solar Thermal Electricity Association (ESTELA) and the International Energy Agency's (IEA) SolarPACES group, says huge investments would also create jobs and fight climate change.
"Solar power plants are the next big thing in renewable energy," says Sven Teske of Greenpeace International and co-author of the report.
The report focuses on a technique called concentrating solar power (CSP), which uses mirrors to concentrate the sun's energy and convert it to heat and then to electricity.
CSP plants are suited to hot, cloudless regions such as deserts in the Sahara or the Middle East.
The new report says investments in CSP plants were set to exceed 2 billion euros (US$2.80 billion) worldwide this year, with the biggest installations under construction in southern Spain and California.
"Concentrating solar power could meet up to 7% of the world's projected power needs in 2030 and a full quarter by 2050," the report says, of the most optimistic scenario.
Click here for more on this topic
The study, by Greenpeace, the European Solar Thermal Electricity Association (ESTELA) and the International Energy Agency's (IEA) SolarPACES group, says huge investments would also create jobs and fight climate change.
"Solar power plants are the next big thing in renewable energy," says Sven Teske of Greenpeace International and co-author of the report.
The report focuses on a technique called concentrating solar power (CSP), which uses mirrors to concentrate the sun's energy and convert it to heat and then to electricity.
CSP plants are suited to hot, cloudless regions such as deserts in the Sahara or the Middle East.
The new report says investments in CSP plants were set to exceed 2 billion euros (US$2.80 billion) worldwide this year, with the biggest installations under construction in southern Spain and California.
"Concentrating solar power could meet up to 7% of the world's projected power needs in 2030 and a full quarter by 2050," the report says, of the most optimistic scenario.
Click here for more on this topic
Rising sea levels: Survival tips from 5000 BC
by Catherine Brahic
WITH rising seas lapping at coastal cities and threatening to engulf entire islands in the not-too-distant future, it's easy to assume our only option will be to abandon them and head for the hills. There may be another way, however. Archaeological sites in the Caribbean, dating back to 5000 BC, show that some ancient civilisations had it just as bad as anything we are expecting. Yet not only did they survive a changing coastline and more storm surges and hurricanes: they stayed put and successfully adapted to the changing world. Now archaeologists are working out how they managed it and finding ways that we might learn from their example.
The sea-level rise that our ancestors dealt with had nothing to do with human-induced climate change, of course: it was a hangover from the last ice age. As the massive ice sheet that lay on North America melted, the continent was buoyed upwards. As a result, the northern Caribbean, on the other end of the same tectonic plate, sank, making seas in the region rise up to 5 metres over 5000 years.
Click to read more
WITH rising seas lapping at coastal cities and threatening to engulf entire islands in the not-too-distant future, it's easy to assume our only option will be to abandon them and head for the hills. There may be another way, however. Archaeological sites in the Caribbean, dating back to 5000 BC, show that some ancient civilisations had it just as bad as anything we are expecting. Yet not only did they survive a changing coastline and more storm surges and hurricanes: they stayed put and successfully adapted to the changing world. Now archaeologists are working out how they managed it and finding ways that we might learn from their example.
The sea-level rise that our ancestors dealt with had nothing to do with human-induced climate change, of course: it was a hangover from the last ice age. As the massive ice sheet that lay on North America melted, the continent was buoyed upwards. As a result, the northern Caribbean, on the other end of the same tectonic plate, sank, making seas in the region rise up to 5 metres over 5000 years.
Click to read more
If we all painted our roofs white, it could do a surprising amount to combat global warming
Obama's climate guru: Paint your roof white!
By Steve Connor, Science Editor
Some people believe that nuclear power is the answer to climate change, others have proposed green technologies such as wind or solar power, but Barack Obama's top man on global warming has suggested something far simpler – painting your roof white.
Steven Chu, the US Secretary of Energy and a Nobel prize-winning scientist, said yesterday that making roofs and pavements white or light-coloured would help to reduce global warming by both conserving energy and reflecting sunlight back into space. It would, he said, be the equivalent of taking all the cars in the world off the road for 11 years.
Speaking in London prior to a meeting of some of the world's best minds on how to combat climate change, Dr Chu said the simple act of painting roofs white could have a dramatic impact on the amount of energy used to keep buildings comfortable, as well as directly offsetting global warming by increasing the reflectivity of the Earth.
"If that building is air-conditioned, it's going to be a lot cooler, it can use 10 or 15 per cent less electricity," he said. "You also do something in that you change the albedo of the Earth – you make it more reflective. So the sunlight comes down and it actually goes back up – there is no greenhouse effect," Dr Chu said.
When sunlight is reflected off a white or light-coloured surface much of that light will pass through the atmosphere and back into space, unlike the infrared radiation emitted from the Earth's warmed-up surface, which is blocked by greenhouse gases and causes global warming. "What we're doing is that, as we put in more greenhouse gases, we're putting in more insulation for infrared light. So if you make white roofs and the sunlight comes in, it goes right through that [insulation]," said Dr Chu.
The principle could also be extended to cars where white or "cool colours" designed to reflect light and radiation could make vehicles more energy efficient in summer. "If all vehicles were light-coloured, there could be considerable savings because then you can downsize the air conditioning... and downsizing the air conditioner means more efficient air conditioning and a considerable reduction in energy," he said.
Asked about whether the US administration has any plans to manipulate the climate artificially using large-scale geoengineering programmes, Dr Chu said there were no such plans "at this time". But painting surfaces white is one geoengineering proposal that he is taking seriously.
"Now you smile, but if you look at all the buildings and make all the roofs white, and if you make the pavement a more concrete-type of colour than a black-type of colour, and you do this uniformly... It's the equivalent of reducing the carbon emissions due to all the cars in the world by 11 years," he said.
"It's like you've just taken them off the road for 11 years. It's actually geoengineering."
The idea would even work in countries with temperate climates, such as Britain, because white-coloured roofs would help to reflect the radiated heat from homes and offices back into the building during winter months, said Dr Chu. One unresolved issue concerns the aesthetic considerations of making sloping roofs white. But with flat roofs that are not visible from the street, there should be no objection to painting them white, he said
Dr Chu is one of 20 Nobel prize-winning scientists attending a meeting on climate change at the Royal Society and St James's Palace organised by Cambridge University. He said energy efficiency will be the most immediate way of reducing emissions of greenhouse gases.
The white revolution: How it would work
* The idea of painting surfaces white to conserve energy is being actively pursued by the US. Earlier this month, Barack Obama's chief scientific adviser, John Holdren, received a scientific memorandum on the subject.
* Scientists estimate that making roofs and pavements white or more light-coloured would counter global warming with "negative radiative forcing" – reflecting sunlight back into space. They said that retrofitting urban roofs and pavements in tropical and temperate regions with solar-reflective materials would offset about 44 billion tonnes of carbon dioxide.
* The scientists said it would lower the cost of air conditioning, making buildings more comfortable and mitigate the "urban heat island" effect caused by the concentration of concrete surfaces in cities.
Actual story can be found here.
By Steve Connor, Science Editor
Some people believe that nuclear power is the answer to climate change, others have proposed green technologies such as wind or solar power, but Barack Obama's top man on global warming has suggested something far simpler – painting your roof white.
Steven Chu, the US Secretary of Energy and a Nobel prize-winning scientist, said yesterday that making roofs and pavements white or light-coloured would help to reduce global warming by both conserving energy and reflecting sunlight back into space. It would, he said, be the equivalent of taking all the cars in the world off the road for 11 years.
Speaking in London prior to a meeting of some of the world's best minds on how to combat climate change, Dr Chu said the simple act of painting roofs white could have a dramatic impact on the amount of energy used to keep buildings comfortable, as well as directly offsetting global warming by increasing the reflectivity of the Earth.
"If that building is air-conditioned, it's going to be a lot cooler, it can use 10 or 15 per cent less electricity," he said. "You also do something in that you change the albedo of the Earth – you make it more reflective. So the sunlight comes down and it actually goes back up – there is no greenhouse effect," Dr Chu said.
When sunlight is reflected off a white or light-coloured surface much of that light will pass through the atmosphere and back into space, unlike the infrared radiation emitted from the Earth's warmed-up surface, which is blocked by greenhouse gases and causes global warming. "What we're doing is that, as we put in more greenhouse gases, we're putting in more insulation for infrared light. So if you make white roofs and the sunlight comes in, it goes right through that [insulation]," said Dr Chu.
The principle could also be extended to cars where white or "cool colours" designed to reflect light and radiation could make vehicles more energy efficient in summer. "If all vehicles were light-coloured, there could be considerable savings because then you can downsize the air conditioning... and downsizing the air conditioner means more efficient air conditioning and a considerable reduction in energy," he said.
Asked about whether the US administration has any plans to manipulate the climate artificially using large-scale geoengineering programmes, Dr Chu said there were no such plans "at this time". But painting surfaces white is one geoengineering proposal that he is taking seriously.
"Now you smile, but if you look at all the buildings and make all the roofs white, and if you make the pavement a more concrete-type of colour than a black-type of colour, and you do this uniformly... It's the equivalent of reducing the carbon emissions due to all the cars in the world by 11 years," he said.
"It's like you've just taken them off the road for 11 years. It's actually geoengineering."
The idea would even work in countries with temperate climates, such as Britain, because white-coloured roofs would help to reflect the radiated heat from homes and offices back into the building during winter months, said Dr Chu. One unresolved issue concerns the aesthetic considerations of making sloping roofs white. But with flat roofs that are not visible from the street, there should be no objection to painting them white, he said
Dr Chu is one of 20 Nobel prize-winning scientists attending a meeting on climate change at the Royal Society and St James's Palace organised by Cambridge University. He said energy efficiency will be the most immediate way of reducing emissions of greenhouse gases.
The white revolution: How it would work
* The idea of painting surfaces white to conserve energy is being actively pursued by the US. Earlier this month, Barack Obama's chief scientific adviser, John Holdren, received a scientific memorandum on the subject.
* Scientists estimate that making roofs and pavements white or more light-coloured would counter global warming with "negative radiative forcing" – reflecting sunlight back into space. They said that retrofitting urban roofs and pavements in tropical and temperate regions with solar-reflective materials would offset about 44 billion tonnes of carbon dioxide.
* The scientists said it would lower the cost of air conditioning, making buildings more comfortable and mitigate the "urban heat island" effect caused by the concentration of concrete surfaces in cities.
Actual story can be found here.
Monday, June 1, 2009
You can recycle your old computer parts into asphalt
Americans throw away a couple million tons of unwanted computers, cell phones, TVs and other electronics every year. Researchers in China, a major destination of the waste, say they know how to get rid of this mounting e-waste: Recycle the nonmetal components of the printed circuit boards found in many electronics for use as an additive to make asphalt more durable. Pavement engineers say it’s not such a bad idea — but unless several potential roadblocks are cleared, don’t expect to drive down a highway paved with old computer parts anytime soon.
Asphalt is the dark, sticky material that binds rocks, gravel and sand together to make the pavement that covers more than 90 percent of U.S. roads. But as anyone who has ever driven down an old highway knows, asphalt is not immune to cracking in the freezing cold or deforming in the sweltering heat.
To recycle more garbage, “people have been dumping all sorts of stuff in asphalt,” says Rajib Mallick, an associate professor of civil and environmental engineering at Worcester Polytechnic Institute in Massachusetts — old tires, ground-up toilets, glass and shingles, to name a few. It can be a good way to reuse unwanted junk, Mallick says, if it improves the asphalt and is environmentally safe.
Given the growing number of unwanted electronics, Zhenming Xu of Shanghai Jiao Tong University in China decided to see if printed circuit boards might do the trick. They crushed the circuit boards into a fine powder and then removed all the metal, leaving behind mainly glass, resins and fibers. Next, they mixed the powder with asphalt and tested the asphalt’s properties at high temperatures. Adding the recycled material made the modified asphalt more viscous and therefore stiffer than unmodified asphalt, the researchers reported in the journal Environmental Science & Technology. Stiffer asphalt should make for a pavement that stands up better to heat.
Click here to read more
Asphalt is the dark, sticky material that binds rocks, gravel and sand together to make the pavement that covers more than 90 percent of U.S. roads. But as anyone who has ever driven down an old highway knows, asphalt is not immune to cracking in the freezing cold or deforming in the sweltering heat.
To recycle more garbage, “people have been dumping all sorts of stuff in asphalt,” says Rajib Mallick, an associate professor of civil and environmental engineering at Worcester Polytechnic Institute in Massachusetts — old tires, ground-up toilets, glass and shingles, to name a few. It can be a good way to reuse unwanted junk, Mallick says, if it improves the asphalt and is environmentally safe.
Given the growing number of unwanted electronics, Zhenming Xu of Shanghai Jiao Tong University in China decided to see if printed circuit boards might do the trick. They crushed the circuit boards into a fine powder and then removed all the metal, leaving behind mainly glass, resins and fibers. Next, they mixed the powder with asphalt and tested the asphalt’s properties at high temperatures. Adding the recycled material made the modified asphalt more viscous and therefore stiffer than unmodified asphalt, the researchers reported in the journal Environmental Science & Technology. Stiffer asphalt should make for a pavement that stands up better to heat.
Click here to read more
So it's going to get a little hotter, why worry?
by carl zimmer
The earth’s climate has, of course, fluctuated frequently — and at times wildly — over hundreds of millions of years, long before humans began pouring heat-trapping gases into the atmosphere. So why the concern over the current surge of warming, brought about largely by human activity? Anthony Barnosky, a University of California, Berkeley, scientist who has studied previous eras of climate change, succinctly sums up the problem: Too much warming, too fast.
In his new book, Heatstroke: Nature in an Age of Global Warming, Barnosky lays out his concerns that the planet’s fauna and flora — hemmed in by 6.5 billion people and facing steadily rising temperatures — will simply not be able to keep up with the pace of change, leading to large-scale extinctions. In previous periods of warming, when the earth moved from glacial to interglacial periods, temperatures have risen by 5 degrees C (9 degrees F) in the course of several thousand years. But, Barnosky explains, it is entirely possible that unless something is done to rein in greenhouse gas emissions, the planet could experience that magnitude of warming in a century or two.
Click here to read full story
The earth’s climate has, of course, fluctuated frequently — and at times wildly — over hundreds of millions of years, long before humans began pouring heat-trapping gases into the atmosphere. So why the concern over the current surge of warming, brought about largely by human activity? Anthony Barnosky, a University of California, Berkeley, scientist who has studied previous eras of climate change, succinctly sums up the problem: Too much warming, too fast.
In his new book, Heatstroke: Nature in an Age of Global Warming, Barnosky lays out his concerns that the planet’s fauna and flora — hemmed in by 6.5 billion people and facing steadily rising temperatures — will simply not be able to keep up with the pace of change, leading to large-scale extinctions. In previous periods of warming, when the earth moved from glacial to interglacial periods, temperatures have risen by 5 degrees C (9 degrees F) in the course of several thousand years. But, Barnosky explains, it is entirely possible that unless something is done to rein in greenhouse gas emissions, the planet could experience that magnitude of warming in a century or two.
Click here to read full story
Mars had a wet, windy and wild past
Based on a Cornell University news release
After thoroughly investigating Victoria Crater on Mars for two years, the instruments aboard the Rover Opportunity reveal more evidence of our neighboring red planet's windy, wet and wild past. The data returned by the mission is valuable in determining whether or not Mars once supported an environment suitable for life. The overview of the findings – compiled in one source – is published in the May 22 issue of the journal Science.
Opportunity's two-year exploration of Victoria Crater – a half-mile wide and 250 feet deep – yielded a treasury of information about the planet's geologic history and supported previous findings indicating that water once flowed on the planet's surface, according to Steve Squyres, Cornell professor of astronomy and the principal investigator for NASA's Mars Exploration Rover mission. The rover is now heading south toward Endeavor crater, 8.5 miles away.
Click here to read more
After thoroughly investigating Victoria Crater on Mars for two years, the instruments aboard the Rover Opportunity reveal more evidence of our neighboring red planet's windy, wet and wild past. The data returned by the mission is valuable in determining whether or not Mars once supported an environment suitable for life. The overview of the findings – compiled in one source – is published in the May 22 issue of the journal Science.
Opportunity's two-year exploration of Victoria Crater – a half-mile wide and 250 feet deep – yielded a treasury of information about the planet's geologic history and supported previous findings indicating that water once flowed on the planet's surface, according to Steve Squyres, Cornell professor of astronomy and the principal investigator for NASA's Mars Exploration Rover mission. The rover is now heading south toward Endeavor crater, 8.5 miles away.
Click here to read more
The bombardment of Earth nearly 4 billion years ago by huge asteroids may have given life a boost
The bombardment of Earth nearly 4 billion years ago by asteroids as large as Kansas would not have had the firepower to extinguish potential early life on the planet and may even have given it a boost, says a new University of Colorado at Boulder study.
Impact evidence from lunar samples, meteorites and the pockmarked surfaces of the inner planets paints a picture of a violent environment in the solar system during the Hadean Eon 4.5 to 3.8 billion years ago, particularly through a cataclysmic event known as the Late Heavy Bombardment about 3.9 million years ago. Although many believe the bombardment would have sterilized Earth, the new study shows it would have melted only a fraction of Earth's crust, and that microbes could well have survived in subsurface habitats, insulated from the destruction.
"These new results push back the possible beginnings of life on Earth to well before the bombardment period 3.9 billion years ago," said CU-Boulder Research Associate Oleg Abramov. "It opens up the possibility that life emerged as far back as 4.4 billion years ago, about the time the first oceans are thought to have formed."
A paper on the subject by Abramov and CU-Boulder geological sciences Professor Stephen Mojzsis appears in the May 21 issue of Nature.
Because physical evidence of Earth's early bombardment has been erased by weathering and plate tectonics over the eons, the researchers used data from Apollo moon rocks, impact records from the moon, Mars and Mercury, and previous theoretical studies to build three-dimensional computer models that replicate the bombardment. Abramov and Mojzsis plugged in asteroid size, frequency and distribution estimates into their simulations to chart the damage to the Earth during the Late Heavy Bombardment, which is thought to have lasted for 20 million to 200 million years.
Click here to read more
Impact evidence from lunar samples, meteorites and the pockmarked surfaces of the inner planets paints a picture of a violent environment in the solar system during the Hadean Eon 4.5 to 3.8 billion years ago, particularly through a cataclysmic event known as the Late Heavy Bombardment about 3.9 million years ago. Although many believe the bombardment would have sterilized Earth, the new study shows it would have melted only a fraction of Earth's crust, and that microbes could well have survived in subsurface habitats, insulated from the destruction.
"These new results push back the possible beginnings of life on Earth to well before the bombardment period 3.9 billion years ago," said CU-Boulder Research Associate Oleg Abramov. "It opens up the possibility that life emerged as far back as 4.4 billion years ago, about the time the first oceans are thought to have formed."
A paper on the subject by Abramov and CU-Boulder geological sciences Professor Stephen Mojzsis appears in the May 21 issue of Nature.
Because physical evidence of Earth's early bombardment has been erased by weathering and plate tectonics over the eons, the researchers used data from Apollo moon rocks, impact records from the moon, Mars and Mercury, and previous theoretical studies to build three-dimensional computer models that replicate the bombardment. Abramov and Mojzsis plugged in asteroid size, frequency and distribution estimates into their simulations to chart the damage to the Earth during the Late Heavy Bombardment, which is thought to have lasted for 20 million to 200 million years.
Click here to read more
Brain cells take time out while you sleep
By Tina Hesman Saey
Even neurons need quiet time. A new study shows the brain cells take time out while you sleep, preventing you from waking up at the drop of a hat or other nonthreatening object.
For decades, scientists have been measuring electrical activity in the brain during sleep with electroencephalograms, or EEGs. Researchers easily recognize the hallmark dips and blips of each stage of sleep, but what brain cells are doing to produce the signals hasn’t been apparent.
Now, a new study in the May 22 Science shows that a prominent electrical signal of slow-wave sleep, called the K-complex, indicates downtime for neurons. The quiet periods could help people ignore distractions, such as sounds and touches, and stay asleep, the researchers report.
K-complexes appear as sharp dips in EEG tracings. The events happen shortly after a person falls asleep, during a period of slow-wave sleep when people are transitioning from light sleep into the heaviest periods of deep sleep. Such dips correspond to a quieting of brain cell activity in animals. Though the traditional electrodes used in EEG measure activity over large areas on the surface of the outer layer of the human brain — the cortex — no one really knew what the signals indicated about fine-scale brain activity in the cortex’s deeper layers.
In the new study, researchers in the United States and Hungary recorded sleep patterns in eight people with epilepsy. The eight people had previously had surgery to implant a series of 24 microelectrodes in each of their brains so doctors could pinpoint the source of the epileptic seizures. The participants had normal sleep patterns.
Click here to read more
Even neurons need quiet time. A new study shows the brain cells take time out while you sleep, preventing you from waking up at the drop of a hat or other nonthreatening object.
For decades, scientists have been measuring electrical activity in the brain during sleep with electroencephalograms, or EEGs. Researchers easily recognize the hallmark dips and blips of each stage of sleep, but what brain cells are doing to produce the signals hasn’t been apparent.
Now, a new study in the May 22 Science shows that a prominent electrical signal of slow-wave sleep, called the K-complex, indicates downtime for neurons. The quiet periods could help people ignore distractions, such as sounds and touches, and stay asleep, the researchers report.
K-complexes appear as sharp dips in EEG tracings. The events happen shortly after a person falls asleep, during a period of slow-wave sleep when people are transitioning from light sleep into the heaviest periods of deep sleep. Such dips correspond to a quieting of brain cell activity in animals. Though the traditional electrodes used in EEG measure activity over large areas on the surface of the outer layer of the human brain — the cortex — no one really knew what the signals indicated about fine-scale brain activity in the cortex’s deeper layers.
In the new study, researchers in the United States and Hungary recorded sleep patterns in eight people with epilepsy. The eight people had previously had surgery to implant a series of 24 microelectrodes in each of their brains so doctors could pinpoint the source of the epileptic seizures. The participants had normal sleep patterns.
Click here to read more
Overfishing is a problem with a thousand years of history
Europeans started over-exploiting freshwater fish at least 1000 years ago, according to historical studies that could help manage depleted modern fish stocks worldwide.
Whales teemed in waters off New Zealand in the 19th century and a now almost non-existent cod stock in the Gulf of Maine once totalled tens of thousands of tonnes a year, according to historical records.
Records reconstructed from everything from Russian monastery purchases to US schooner logs indicate that overfishing has been happening in many parts of the world for centuries and that fish used to be more abundant, and bigger, than now.
"We see similar patterns of human impacts on the oceans pretty much everywhere, and in many cases real depletion," says Dr Andy Rosenberg of the University of New Hampshire, a leader of a project called the History of Marine Animal Population (HMAP).
The findings, part of a 10-year Census of Marine Life due for completion in 2010, will be presented this week at the Oceans Past conference in Vancouver.
Click on the link to learn more on this story:
Whales teemed in waters off New Zealand in the 19th century and a now almost non-existent cod stock in the Gulf of Maine once totalled tens of thousands of tonnes a year, according to historical records.
Records reconstructed from everything from Russian monastery purchases to US schooner logs indicate that overfishing has been happening in many parts of the world for centuries and that fish used to be more abundant, and bigger, than now.
"We see similar patterns of human impacts on the oceans pretty much everywhere, and in many cases real depletion," says Dr Andy Rosenberg of the University of New Hampshire, a leader of a project called the History of Marine Animal Population (HMAP).
The findings, part of a 10-year Census of Marine Life due for completion in 2010, will be presented this week at the Oceans Past conference in Vancouver.
Click on the link to learn more on this story:
Sunday, May 24, 2009
A Potential Breakthrough
New solar thermal technology overcomes a major challenge facing solar power – how to store the sun’s heat for use at night or on a rainy day. As researchers tout its promise, solar thermal plants are under construction or planned from Spain to Australia to the American Southwest.
by david biello
Click on the link for full story
by david biello
Click on the link for full story
Should DDT Be Used to Combat Malaria?
A panel of scientists recommended today that the spraying of DDT in malaria-plagued Africa and Asia should be greatly reduced because people are exposed in their homes to high levels that may cause serious health effects.
The scientists from the United States and South Africa said the insecticide, banned decades ago in most of the world, should only be used as a last resort in combating malaria.
Click on the link to read the complete story
The scientists from the United States and South Africa said the insecticide, banned decades ago in most of the world, should only be used as a last resort in combating malaria.
Click on the link to read the complete story
Creatures living on violent undersea volcano give climate change survival clue
An active underwater volcano which spews torrents of lava and noxious gas has become a surprising hotspot for sea critters, scientists revealed today.
Studying them may provide answers to how sea life could adapt to the world's increasingly acidic oceans, they said.
Click here to read full article
Studying them may provide answers to how sea life could adapt to the world's increasingly acidic oceans, they said.
Click here to read full article
Take a look at the beauty Hubble brought us over 19 years of operation
Beautiful photos which hubble telescope has bought us over the years at the below link. Follow the link below:
Hubble photos
Hubble photos
The day the universe froze
Imagine a time when the entire universe froze. According to a new model for dark energy, that is essentially what happened about 11.5 billion years ago, when the universe was a quarter of the size it is today. The model, published online May 6 in the journal Physical Review D, was developed by Research Associate Sourish Dutta and Professor of Physics Robert Scherrer at Vanderbilt University, working with Professor of Physics Stephen Hsu and graduate student David Reeb at the University of Oregon.
A cosmological phase transition – similar to freezing – is one of the distinctive aspects of this latest effort to account for dark energy – the mysterious negative force that cosmologists now think makes up more than 70 percent of all the energy and matter in the universe and is pushing the universe apart at an ever-faster rate.
Another feature that distinguishes the new formulation is that it makes a testable prediction regarding the expansion rate of the universe. In addition, the micro-explosions created by the largest particle colliders should excite the dark energy field and these excitations could appear as exotic, never-seen-before sub-atomic particles.
"One of the things that is very unsatisfying about many of the existing explanations for dark energy is that they are difficult to test," says Scherrer, "We designed a model that can interact with normal matter and so has observable consequences."
The model associates dark energy with something called vacuum energy. Like a number of existing theories, it proposes that space itself is the source of the repulsive energy that is pushing the universe apart. For many years, scientists thought that the energy of empty space averaged zero. But the discovery of quantum mechanics changed this view. According to quantum theory, empty space is filled with pairs of "virtual" particles that spontaneously pop into and out of existence too quickly to be detected.
The full story can be read at;
http://esciencenews.com/articles/2009/05/08/the.day.universe.froze
A cosmological phase transition – similar to freezing – is one of the distinctive aspects of this latest effort to account for dark energy – the mysterious negative force that cosmologists now think makes up more than 70 percent of all the energy and matter in the universe and is pushing the universe apart at an ever-faster rate.
Another feature that distinguishes the new formulation is that it makes a testable prediction regarding the expansion rate of the universe. In addition, the micro-explosions created by the largest particle colliders should excite the dark energy field and these excitations could appear as exotic, never-seen-before sub-atomic particles.
"One of the things that is very unsatisfying about many of the existing explanations for dark energy is that they are difficult to test," says Scherrer, "We designed a model that can interact with normal matter and so has observable consequences."
The model associates dark energy with something called vacuum energy. Like a number of existing theories, it proposes that space itself is the source of the repulsive energy that is pushing the universe apart. For many years, scientists thought that the energy of empty space averaged zero. But the discovery of quantum mechanics changed this view. According to quantum theory, empty space is filled with pairs of "virtual" particles that spontaneously pop into and out of existence too quickly to be detected.
The full story can be read at;
http://esciencenews.com/articles/2009/05/08/the.day.universe.froze
The oldest submerged town in the world is about to give up its secrets, with the help of equipment that could revolutionise underwater archaeology
The ancient town of Pavlopetri lies in three to four metres of water just off the coast of southern Laconia in Greece. The ruins date from at least 2800 BC through to intact buildings, courtyards, streets, chamber tombs and some thirty-seven cist graves which are thought to belong to the Mycenaean period (c.1680-1180 BC). This Bronze Age phase of Greece provides the historical setting for much Ancient Greek literature and myth, including Homer's Age of Heroes.
Underwater archaeologist Dr Jon Henderson, from The University of Nottingham, will be the first archaeologist to have official access to the site in 40 years. Despite its potential international importance no work has been carried out at the site since it was first mapped in 1968 and Dr Henderson has had to get special permission from the Greek government to examine the submerged town.
Although Mycenaean power was largely based on their control of the sea, little is known about the workings of the harbour towns of the period as archaeology to date has focused on the better known inland palaces and citadels. Pavlopetri was presumably once a thriving harbour town where the inhabitants conducted local and long distance trade throughout the Mediterranean — its sandy and well-protected bay would have been ideal for beaching Bronze Age ships. As such the site offers major new insights into the workings of Mycenaean society.
Read the full story at:
http://www.physorg.com/news161274284.html
Underwater archaeologist Dr Jon Henderson, from The University of Nottingham, will be the first archaeologist to have official access to the site in 40 years. Despite its potential international importance no work has been carried out at the site since it was first mapped in 1968 and Dr Henderson has had to get special permission from the Greek government to examine the submerged town.
Although Mycenaean power was largely based on their control of the sea, little is known about the workings of the harbour towns of the period as archaeology to date has focused on the better known inland palaces and citadels. Pavlopetri was presumably once a thriving harbour town where the inhabitants conducted local and long distance trade throughout the Mediterranean — its sandy and well-protected bay would have been ideal for beaching Bronze Age ships. As such the site offers major new insights into the workings of Mycenaean society.
Read the full story at:
http://www.physorg.com/news161274284.html
In Chile, the birds are dying, and no one knows why
A series of environmental disasters in Chile have puzzled scientists. Some are blaming global warming.
BY GIDEON LONG
SPECIAL TO THE MIAMI HERALD
Chilean scientists are investigating three mysterious ecological disasters that have caused the deaths of hundreds of penguins, millions of sardines and about 2,000 baby flamingos in the past few months.
The events started to unfold in March, when the remains of about 1,200 penguins were found on a remote beach in southern Chile. Then came the sardines -- tons of them -- dead and washed up on a nearby stretch of coastline. The stench forced nearby schools to close, and the army was called in to shovel piles of rotting fish off the sand.
Farther north, thousands of rare Andean flamingos abandoned their nests on a salt lake in the Atacama Desert. The eggs failed to hatch and, over a period of three months, all 2,000 chicks died. The extent of the damage was discovered in April, during an inspection.
No one knows for sure what caused these three apparently unrelated ecological tragedies, although there are many theories. Global warming has been blamed, as have overfishing, pollution and bacterial disease. In the north, ecologists have accused mining companies of fatally altering the flamingos' habitat by draining the area of subterranean water.
Whatever the explanations, the events have caused unease. A suspicion that mankind is to blame has created the feeling that maybe Chile should be doing more to protect its spectacularly rich wildlife.
''Chile has very primitive legislation governing the management of its fisheries,'' said Alex Muñoz, executive director of Oceana, an international marine conservation group with offices in Santiago. ``Our marine resources are facing big problems such as overfishing, and the destruction of vulnerable marine ecosystems by industrial trawling.
``We are still waiting for an official report from the government, but we should consider the lack of sound management of fisheries if we want to work out what caused the death of the penguins and the sardines.''
Muñoz said the penguins might have starved to death due to depletion of fish stocks. While a preliminary report from a local university supports this theory, another suggests they were killed by a bacterial infection. It's unclear whether the deaths were related to those of the sardines just days later.
The full article can be read at:
http://www.miamiherald.com/news/americas/v-fullstory/story/1054864.html
BY GIDEON LONG
SPECIAL TO THE MIAMI HERALD
Chilean scientists are investigating three mysterious ecological disasters that have caused the deaths of hundreds of penguins, millions of sardines and about 2,000 baby flamingos in the past few months.
The events started to unfold in March, when the remains of about 1,200 penguins were found on a remote beach in southern Chile. Then came the sardines -- tons of them -- dead and washed up on a nearby stretch of coastline. The stench forced nearby schools to close, and the army was called in to shovel piles of rotting fish off the sand.
Farther north, thousands of rare Andean flamingos abandoned their nests on a salt lake in the Atacama Desert. The eggs failed to hatch and, over a period of three months, all 2,000 chicks died. The extent of the damage was discovered in April, during an inspection.
No one knows for sure what caused these three apparently unrelated ecological tragedies, although there are many theories. Global warming has been blamed, as have overfishing, pollution and bacterial disease. In the north, ecologists have accused mining companies of fatally altering the flamingos' habitat by draining the area of subterranean water.
Whatever the explanations, the events have caused unease. A suspicion that mankind is to blame has created the feeling that maybe Chile should be doing more to protect its spectacularly rich wildlife.
''Chile has very primitive legislation governing the management of its fisheries,'' said Alex Muñoz, executive director of Oceana, an international marine conservation group with offices in Santiago. ``Our marine resources are facing big problems such as overfishing, and the destruction of vulnerable marine ecosystems by industrial trawling.
``We are still waiting for an official report from the government, but we should consider the lack of sound management of fisheries if we want to work out what caused the death of the penguins and the sardines.''
Muñoz said the penguins might have starved to death due to depletion of fish stocks. While a preliminary report from a local university supports this theory, another suggests they were killed by a bacterial infection. It's unclear whether the deaths were related to those of the sardines just days later.
The full article can be read at:
http://www.miamiherald.com/news/americas/v-fullstory/story/1054864.html
Friday, May 8, 2009
Thursday, April 23, 2009
Today is Earth Day
Earth Day is being observed today. This means switching off electricity all over the planet for an hour which will same enormous energy on earth.
Every day has to be observed as Earth day by turning off unused lights everyday, not wasting water and consuming required gas & petrol. This in turn is going to be of great help to our future generations who are none but our own children.
Every day has to be observed as Earth day by turning off unused lights everyday, not wasting water and consuming required gas & petrol. This in turn is going to be of great help to our future generations who are none but our own children.
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