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Great Barrier Reef's great-grandmother is unearthed
Ippei Naoi/flickr/getty
IN BRIEF Two kilos of antimatter, please
Here lies the Great Barrier Reef’s great-grandmother JUST 600 metres away from the Great Barrier Reef, the jewel in Australia’s crown, a less spectacular but more ancient reef has been discovered. The first hint of its existence came in 2007, when seismic and sonar measurements revealed odd ridges and lagoons on the seabed. Confirmation arrived in February this year, when an international team extracted 34 sediment cores from three sites on the seabed, revealing a fossilised coral reef that reaches 110 metres into the sea floor. Preliminary dating of the core indicates that the coral is up to 169,000 years old.
“This is the great-grandmother of the Great Barrier Reef,” says John Pandolfi of the University of Queensland, who was not on the mission. It is “a very important discovery”, he says, and should provide new insights into the genesis of the reef. The prevailing wisdom has been that the Great Barrier Reef sits atop an older, dead reef, but 110 metres beneath the live reef, the team hit rock. Corals need light to live, and Pandolfi now thinks that when rising sea levels at the end of the last ice age threatened to put the lights out on the ancient reef, some larvae travelled to shallower waters and seeded the modern one. The findings were presented by Jody Webster of the University of Sydney at the Integrated Ocean Drilling Program conference in Bremen, Germany, in July.
Killer T-cells, the fix for organ rejection? A CONVENIENT type of killer white blood cell could make organ rejection a thing of the past. The cells suppress the immune response in the livers of mice, without affecting the rest of the immune system. Humans have this type of blood cell, so it might be possible to create immunetolerant organs for transplant. Marta Monteiro and colleagues at the University of Lisbon, 16 | NewScientist | 21 August 2010
Portugal, studied mice protected from the animal equivalent of multiple sclerosis by natural killer T-cells (NKT), a class of white blood cell which helps to control the immune system. They discovered a population of NKT cells that have a gene that controls so-called regulatory T-cells, whose role is to suppress the immune response. The team labelled these so called NKTregs
with fluorescent markers, then injected them back into mice. Unlike other types of regulatory T-cells, which move throughout the body, the NKTreg cells headed straight for the liver, where they suppressed immune function (Journal of Immunology, DOI: 10.4049/jimmunol.1000359). “Using these new cells we might achieve organ acceptance in liver transplants, without touching the remaining immune system,” says co-author Luis Graca.
LASERS could one day churn out antimatter for use in particle accelerators. Concentrate light into a tight enough space, and quantum effects will cause it to spontaneously transform into pairs of electrons and positrons. Laser experiments at the SLAC National Accelerator Laboratory, California, in 1997 created one such pair at a time. Now, Alexander Fedotov of the Moscow Engineering Physics Institute in Russia and his colleagues have calculated that more powerful lasers set to be built in the next decade could create millions of pairs in a chain reaction. The first pair would be accelerated by the laser until it emitted light that spawned more pairs (arxiv.org/abs/1004.5398). Such antimatter could be used in the proposed International Linear Collider, which will need lots of positrons to use in collision experiments with electrons.
Humans wiped out giant turtles THE giant horned turtles of the Pacific became extinct later than we thought – and humans were to blame. The half-tonne meiolaniid turtles were thought to have died out 30,000 to 40,000 years ago because of climate change. Now butchered turtle remains have been found in the South Pacific island nation of Vanuatu. Carbon dating shows that the most recent bones are between 2890 and 2760 years old. Humans arrived 3000 years ago. “Within 200 years, the turtles were gone,” says Trevor Worthy of the University of New South Wales in Sydney, Australia, who identified the bones (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1005780107).
IN BRIEF Two kilos of antimatter, please
Here lies the Great Barrier Reef’s great-grandmother JUST 600 metres away from the Great Barrier Reef, the jewel in Australia’s crown, a less spectacular but more ancient reef has been discovered. The first hint of its existence came in 2007, when seismic and sonar measurements revealed odd ridges and lagoons on the seabed. Confirmation arrived in February this year, when an international team extracted 34 sediment cores from three sites on the seabed, revealing a fossilised coral reef that reaches 110 metres into the sea floor. Preliminary dating of the core indicates that the coral is up to 169,000 years old.
“This is the great-grandmother of the Great Barrier Reef,” says John Pandolfi of the University of Queensland, who was not on the mission. It is “a very important discovery”, he says, and should provide new insights into the genesis of the reef. The prevailing wisdom has been that the Great Barrier Reef sits atop an older, dead reef, but 110 metres beneath the live reef, the team hit rock. Corals need light to live, and Pandolfi now thinks that when rising sea levels at the end of the last ice age threatened to put the lights out on the ancient reef, some larvae travelled to shallower waters and seeded the modern one. The findings were presented by Jody Webster of the University of Sydney at the Integrated Ocean Drilling Program conference in Bremen, Germany, in July.
Killer T-cells, the fix for organ rejection? A CONVENIENT type of killer white blood cell could make organ rejection a thing of the past. The cells suppress the immune response in the livers of mice, without affecting the rest of the immune system. Humans have this type of blood cell, so it might be possible to create immunetolerant organs for transplant. Marta Monteiro and colleagues at the University of Lisbon, 16 | NewScientist | 21 August 2010
Portugal, studied mice protected from the animal equivalent of multiple sclerosis by natural killer T-cells (NKT), a class of white blood cell which helps to control the immune system. They discovered a population of NKT cells that have a gene that controls so-called regulatory T-cells, whose role is to suppress the immune response. The team labelled these so called NKTregs
with fluorescent markers, then injected them back into mice. Unlike other types of regulatory T-cells, which move throughout the body, the NKTreg cells headed straight for the liver, where they suppressed immune function (Journal of Immunology, DOI: 10.4049/jimmunol.1000359). “Using these new cells we might achieve organ acceptance in liver transplants, without touching the remaining immune system,” says co-author Luis Graca.
LASERS could one day churn out antimatter for use in particle accelerators. Concentrate light into a tight enough space, and quantum effects will cause it to spontaneously transform into pairs of electrons and positrons. Laser experiments at the SLAC National Accelerator Laboratory, California, in 1997 created one such pair at a time. Now, Alexander Fedotov of the Moscow Engineering Physics Institute in Russia and his colleagues have calculated that more powerful lasers set to be built in the next decade could create millions of pairs in a chain reaction. The first pair would be accelerated by the laser until it emitted light that spawned more pairs (arxiv.org/abs/1004.5398). Such antimatter could be used in the proposed International Linear Collider, which will need lots of positrons to use in collision experiments with electrons.
Humans wiped out giant turtles THE giant horned turtles of the Pacific became extinct later than we thought – and humans were to blame. The half-tonne meiolaniid turtles were thought to have died out 30,000 to 40,000 years ago because of climate change. Now butchered turtle remains have been found in the South Pacific island nation of Vanuatu. Carbon dating shows that the most recent bones are between 2890 and 2760 years old. Humans arrived 3000 years ago. “Within 200 years, the turtles were gone,” says Trevor Worthy of the University of New South Wales in Sydney, Australia, who identified the bones (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1005780107).