A vast new amber deposit in India has yielded 100 fossil spiders, bees, and flies that date to the Early Eocene, or 52-50 million years ago. These arthropods are not unique -- as would be expected on an island (which India was at that time) -- but have close evolutionary relationships with fossils from the Americas, Europe, and Asia. The amber is also the oldest evidence of a tropical broadleaf rainforest in Asia.Bees, termites, spiders, and flies entombed in a newly-excavated amber deposit are challenging the assumption that India was an isolated island-continent in the Early Eocene, or 52-50 million years ago. Arthropods found in the Cambay deposit from western India are not unique -- as would be expected on an island -- but rather have close evolutionary relationships with fossils from other continents. The amber is also the oldest evidence of a tropical broadleaf rainforest in Asia.
The discovery is published this week in Proceedings of the National Academy of Sciences.
"We know India was isolated, but when and for precisely how long is unclear," says David Grimaldi, curator in the Division of Invertebrate Zoology at the American Museum of Natural History. "The biological evidence in the amber deposit shows that there was some biotic connection."
"The amber shows, similar to an old photo, what life looked like in India just before the collision with the Asian continent," says Jes Rust, professor of Invertebrate Paleontology at the Universität Bonn in Germany. "The insects trapped in the fossil resin cast a new light on the history of the sub-continent."
est in Asia
Friday, October 29, 2010
Antarctica Melting News
The change in the ice mass covering Antarctica is a critical factor in global climate events. Scientists at the GFZ German Research Center for Geosciences have now found that the year by year mass variations in the western Antarctic are mainly attributable to fluctuations in precipitation, which are controlled significantly by the climate phenomenon El Nino. Gravity data collected from space using NASA's Grace satellite show that Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002. The latest data reveal that Antarctica is losing ice at an accelerating rate, too. How is it possible for surface melting to decrease, but for the continent to lose mass anyway? The answer boils down to the fact that ice can flow without melting.
Antarctica is Earth's southernmost continent (including ice and underlying land), encapsulating the South Pole. It is situated in the Antarctic region of the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 5.4 million square miles), it is the fifth-largest continent in area after Asia, Africa, North America, and South America.
Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 1.2 miles, higher than the American Colorado Plateau. There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 1.2 miles thick. If all of this ice melted, it would raise global sea level by about 197 feet.
West Antarctica is very different. Instead of a single continent, it is a series of islands covered by ice. Because it's a group of islands, much of the West Antarctic Ice Sheet (WAIS, in the jargon) is actually sitting on the floor of the Southern Ocean, not on dry land. Parts of it are more than 1 mile below sea level. Pine Island is the largest of these islands and the largest ice stream in West Antarctica is called Pine Island Glacier. The WAIS, if it melted completely, would raise sea level by 16 to 23 feet.
Two areas in Antarctica are of particular interest because of their potential sensitivity to global climate change: the Antarctic Peninsula (which reaches up towards the tip of South America), and the Amundsen Sector of West Antarctica. The peninsula is currently experiencing a warming exceeding the global mean and the disappearance of large ice shelf areas. In the Amundsen Sector there are currently the largest flow rates and mass loss of the Antarctic Ice Sheet.
Glaciers can both melt and move or flow. Both results lead to a faster overall mass loss. Satellite images of more than 300 glaciers on the Antarctic Peninsula have already showed that they were flowing some 12 percent faster in 2003 than they were in 1993. Current data indicates that the "flow rate" is increasing though not in a linear fashion.
In the latest study, the mass balance of both regions is reevaluated from gravity data of the satellite mission GRACE. As a result, the estimates were lower than those of conventional mass balance methods. "With the GRACE time series, it was for the first time possible to observe how the large-scale ice mass varies in the two areas due to fluctuations in rainfall from year to year," said the GFZ scientists Ingo Sasgen.
It has long been known that the Pacific El Niño climate phenomenon and the snowfall in Antarctica are linked. The complementary piece to the warm phase El Nino, the cold phase known as La Nina, also affects the Antarctic climate:
"The cooler La Nina years lead to a strong low pressure area over the Amundsen Sea, which favors heavy rainfall along the Antarctic Peninsula - the ice mass is increasing there. In contrast, the Amundsen area is dominated by dry air from the interior during this time.
El Nino years with their warm phase lead to precisely the opposite pattern: reduced rainfall and mass loss in the Antarctic Peninsula, and an increase in the Amundsen Sector field, respectively" explains Professor Maik Thomas.
The recording of the entire ice mass of the South Pole and its variations is a central task in climate research and still raises many unanswered questions. In principle, the study could show that the continuous gravity data of the GRACE satellite mission contain another important medium-term climate signal.
Antarctica is Earth's southernmost continent (including ice and underlying land), encapsulating the South Pole. It is situated in the Antarctic region of the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 5.4 million square miles), it is the fifth-largest continent in area after Asia, Africa, North America, and South America.
Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 1.2 miles, higher than the American Colorado Plateau. There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 1.2 miles thick. If all of this ice melted, it would raise global sea level by about 197 feet.
West Antarctica is very different. Instead of a single continent, it is a series of islands covered by ice. Because it's a group of islands, much of the West Antarctic Ice Sheet (WAIS, in the jargon) is actually sitting on the floor of the Southern Ocean, not on dry land. Parts of it are more than 1 mile below sea level. Pine Island is the largest of these islands and the largest ice stream in West Antarctica is called Pine Island Glacier. The WAIS, if it melted completely, would raise sea level by 16 to 23 feet.
Two areas in Antarctica are of particular interest because of their potential sensitivity to global climate change: the Antarctic Peninsula (which reaches up towards the tip of South America), and the Amundsen Sector of West Antarctica. The peninsula is currently experiencing a warming exceeding the global mean and the disappearance of large ice shelf areas. In the Amundsen Sector there are currently the largest flow rates and mass loss of the Antarctic Ice Sheet.
Glaciers can both melt and move or flow. Both results lead to a faster overall mass loss. Satellite images of more than 300 glaciers on the Antarctic Peninsula have already showed that they were flowing some 12 percent faster in 2003 than they were in 1993. Current data indicates that the "flow rate" is increasing though not in a linear fashion.
In the latest study, the mass balance of both regions is reevaluated from gravity data of the satellite mission GRACE. As a result, the estimates were lower than those of conventional mass balance methods. "With the GRACE time series, it was for the first time possible to observe how the large-scale ice mass varies in the two areas due to fluctuations in rainfall from year to year," said the GFZ scientists Ingo Sasgen.
It has long been known that the Pacific El Niño climate phenomenon and the snowfall in Antarctica are linked. The complementary piece to the warm phase El Nino, the cold phase known as La Nina, also affects the Antarctic climate:
"The cooler La Nina years lead to a strong low pressure area over the Amundsen Sea, which favors heavy rainfall along the Antarctic Peninsula - the ice mass is increasing there. In contrast, the Amundsen area is dominated by dry air from the interior during this time.
El Nino years with their warm phase lead to precisely the opposite pattern: reduced rainfall and mass loss in the Antarctic Peninsula, and an increase in the Amundsen Sector field, respectively" explains Professor Maik Thomas.
The recording of the entire ice mass of the South Pole and its variations is a central task in climate research and still raises many unanswered questions. In principle, the study could show that the continuous gravity data of the GRACE satellite mission contain another important medium-term climate signal.
Innovation: Portable Breast Scanners
A new portable scanner for detecting early signs of breast cancer has been developed at the University of Manchester by Professor Zhipeng Wu. The device works by radio frequency technology that can show the presence of tumors on an computer screen. The amazing thing is that it can show the image within seconds on the computer screen, rather than a x-ray mammography which takes minutes and can only be done at hospital or specialist care centers. This new technology can revolutionize the early detection for women with breast cancer.
Around the world, breast cancer comprises about ten percent of all cancer incidents for women. Breast cancer can be fatal, but there are different ways of treating it: surgery, hormone therapy, chemotherapy, and radiation. Unfortunately, according to statistics from 2004, breast cancer caused 519,000 deaths and accounted for one percent of all deaths worldwide. The key in beating the disease is to detect the cancer in its infant stage before it has a chance to grow.
Professor Wu, professor at the University's School of Electrical and Electronic Engineering, says that the new portable scanner can offer patients real-time video images that would clearly show the presence of any tumor. The new method would be much quicker and less intrusive. The device could be used at GP offices, reducing wait times and would allow patients to avoid costly and unnecessary mammographies. It can even be used at home.
The patented radio frequency technology uses computer tomography and works with the same technology as a mobile phone. The casing for the device is no larger than a bread basket, making it portable and low-cost.
Mammography, the standard detection for breast cancer, can give results up to 95 percent accuracy for women over 50, but is far less effective for younger women. For those under 50, it provides results that are only up to 60 percent accurate. However, it is at this age when detection is the most important. Thousands of lives could be saved if they are diagnosed and treated at an early stage.
While mammographies use density to detect the cancer, the new radio frequency technique works by detecting the dielectric contrasts between normal and affected breast tissues. The malignant tissue has a higher permittivity and conductivity to radio frequency, and will therefore show up differently (in red) on the scan.
It works instantly, as soon as the breasts are placed in the cup. 30 images can be scanned in real-time, in one second, making the process fast and painless. According to Professor Wu, "The real-time imaging minimizes the chance of missing a breast tumor during scanning. Other systems also need to use a liquid or gel as a matching substance, such as in an ultrasound, to work but with our system you don't need that — it can be done simply in oil, milk, water or even with a bra on."
Professor Wu has submitted his innovation to the IET Innovation Awards under the Electronics category. The winners will be announced this November.
Around the world, breast cancer comprises about ten percent of all cancer incidents for women. Breast cancer can be fatal, but there are different ways of treating it: surgery, hormone therapy, chemotherapy, and radiation. Unfortunately, according to statistics from 2004, breast cancer caused 519,000 deaths and accounted for one percent of all deaths worldwide. The key in beating the disease is to detect the cancer in its infant stage before it has a chance to grow.
Professor Wu, professor at the University's School of Electrical and Electronic Engineering, says that the new portable scanner can offer patients real-time video images that would clearly show the presence of any tumor. The new method would be much quicker and less intrusive. The device could be used at GP offices, reducing wait times and would allow patients to avoid costly and unnecessary mammographies. It can even be used at home.
The patented radio frequency technology uses computer tomography and works with the same technology as a mobile phone. The casing for the device is no larger than a bread basket, making it portable and low-cost.
Mammography, the standard detection for breast cancer, can give results up to 95 percent accuracy for women over 50, but is far less effective for younger women. For those under 50, it provides results that are only up to 60 percent accurate. However, it is at this age when detection is the most important. Thousands of lives could be saved if they are diagnosed and treated at an early stage.
While mammographies use density to detect the cancer, the new radio frequency technique works by detecting the dielectric contrasts between normal and affected breast tissues. The malignant tissue has a higher permittivity and conductivity to radio frequency, and will therefore show up differently (in red) on the scan.
It works instantly, as soon as the breasts are placed in the cup. 30 images can be scanned in real-time, in one second, making the process fast and painless. According to Professor Wu, "The real-time imaging minimizes the chance of missing a breast tumor during scanning. Other systems also need to use a liquid or gel as a matching substance, such as in an ultrasound, to work but with our system you don't need that — it can be done simply in oil, milk, water or even with a bra on."
Professor Wu has submitted his innovation to the IET Innovation Awards under the Electronics category. The winners will be announced this November.
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