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No Snowball Earth
Research news and discovery
GARY WILLIAMS/GETTY
In brief– No Snowball Earth
to lay your instruments before the storm strikes.” Unless you get lucky. In September 2004, hurricane Ivan passed over instruments that Teague’s team had deployed to measure the movement of water in the Gulf of Mexico. HURRICANES can wreak havoc by creating a storm surge – “We thought the instruments would be destroyed, but all a huge wall of water that slams ashore. Now instruments 14 survived intact,” says Teague. The readings revealed a fortuitously placed in the path of hurricane Ivan have given surprise. As the wind speeds increased to about 32 metres invaluable information that could help predict the surges. per second, the ocean currents beneath them also sped up. To understand how winds transfer their energy to the But at even higher wind speeds, the currents died down water to cause the surges, oceanographers usually try to (Science, vol 315, p 1707). measure wind speeds above the ocean surface, but large “Violent winds generate breaking waves, sea spray and waves make this difficult. “We’d really prefer to measure foam, making it harder for the hurricane to get a foothold ocean current speeds directly under hurricanes,” says on the water surface and drag it along,” says Teague. The William Teague of NASA’s Stennis Space Center in Hancock findings should help predict the size of storm surges more county, Mississippi. “But you can’t tell where in the sea accurately from measurements of wind speeds.
Serendipitous sensors pick up the secret of the storm surge
Enzyme spray has earache in its sights EVERY year, millions of children suffer painful earache caused by the bacterium Streptococcus pneumoniae. Tests on mice now suggest that a nasal spray containing viral enzymes called lysins might end this misery. S. pneumoniae bacteria live harmlessly in our noses until respiratory viruses come along and disrupt the nasal membrane, allowing bacteria to migrate to the www.newscientist.com
070331_N_Inbriefs.indd 17
middle ear and start infections. Bacteria-infecting viruses called phages use lysins to destroy bacterial cell walls so that they can escape and infect other cells. To show how they could destroy S. pneumoniae and prevent ear infections, Vincent Fischetti of Rockefeller University in New York and Jonathan McCullers of the St Jude Children’s Research Hospital in Memphis, Tennessee, infected
mice with nasal S. pneumoniae and then treated them with a lysin spray or a mock spray containing no enzyme. When the mice were then infected with a flu virus, none of those treated with lysin developed an ear infection, while 8 out of 10 of those given the mock spray did (PLoS Pathogens, DOI: 10.1371/journal.ppat.0030028). Importantly, the lysin that targets S. pneumoniae does not damage the harmless “commensal” bacteria that protect the ear from other infections.
EARTH suffered from quite a fever around 640 million years ago, with the climate yo-yoing rapidly between severe glaciations and warm periods. This contradicts the Snowball Earth theory that the planet was locked in a relentless and complete glaciation for tens of millions of years. Philip Allen from Imperial College London and colleagues studied chemical weathering in sedimentary rocks between 630 and 640 million years old, exposed in Oman. Sunshine and rain make some minerals in rocks decompose, but not others. By measuring the ratio of weathered to unweathered minerals, Allen’s team was able to identify glacial periods – when very little weathering occurred – and warm ones, which showed strong weathering (Geology, vol 35, p 299). The changes from hot to cold happened too quickly for oceans to have frozen over as the Snowball Earth theory predicts, says Allen.
Protein key to long-life platelets WITHOUT platelets, blood doesn’t clot and wounds don’t heal. Transfusions of platelets save many lives, but platelets have a shelf life of only a few days. There might soon be a way to extend that, however. David Huang and Benjamin Kile of the Walter and Eliza Hall Institute in Melbourne, Australia, have discovered that the lifespan of platelets is dictated by the levels of a protein called Bcl-xL, which dwindle as platelets age (Cell, vol 128, p 1173). Bcl-xL works by blocking the action of another protein called Bak, which would otherwise trigger programmed cell death. The researchers are now searching compounds that increase Bcl-xL levels, mimic it, or block Bak, in order to prolong platelet lifespan. 31 March 2007 | NewScientist | 17
26/3/07 4:40:52 pm
GARY WILLIAMS/GETTY
In brief– No Snowball Earth
to lay your instruments before the storm strikes.” Unless you get lucky. In September 2004, hurricane Ivan passed over instruments that Teague’s team had deployed to measure the movement of water in the Gulf of Mexico. HURRICANES can wreak havoc by creating a storm surge – “We thought the instruments would be destroyed, but all a huge wall of water that slams ashore. Now instruments 14 survived intact,” says Teague. The readings revealed a fortuitously placed in the path of hurricane Ivan have given surprise. As the wind speeds increased to about 32 metres invaluable information that could help predict the surges. per second, the ocean currents beneath them also sped up. To understand how winds transfer their energy to the But at even higher wind speeds, the currents died down water to cause the surges, oceanographers usually try to (Science, vol 315, p 1707). measure wind speeds above the ocean surface, but large “Violent winds generate breaking waves, sea spray and waves make this difficult. “We’d really prefer to measure foam, making it harder for the hurricane to get a foothold ocean current speeds directly under hurricanes,” says on the water surface and drag it along,” says Teague. The William Teague of NASA’s Stennis Space Center in Hancock findings should help predict the size of storm surges more county, Mississippi. “But you can’t tell where in the sea accurately from measurements of wind speeds.
Serendipitous sensors pick up the secret of the storm surge
Enzyme spray has earache in its sights EVERY year, millions of children suffer painful earache caused by the bacterium Streptococcus pneumoniae. Tests on mice now suggest that a nasal spray containing viral enzymes called lysins might end this misery. S. pneumoniae bacteria live harmlessly in our noses until respiratory viruses come along and disrupt the nasal membrane, allowing bacteria to migrate to the www.newscientist.com
070331_N_Inbriefs.indd 17
middle ear and start infections. Bacteria-infecting viruses called phages use lysins to destroy bacterial cell walls so that they can escape and infect other cells. To show how they could destroy S. pneumoniae and prevent ear infections, Vincent Fischetti of Rockefeller University in New York and Jonathan McCullers of the St Jude Children’s Research Hospital in Memphis, Tennessee, infected
mice with nasal S. pneumoniae and then treated them with a lysin spray or a mock spray containing no enzyme. When the mice were then infected with a flu virus, none of those treated with lysin developed an ear infection, while 8 out of 10 of those given the mock spray did (PLoS Pathogens, DOI: 10.1371/journal.ppat.0030028). Importantly, the lysin that targets S. pneumoniae does not damage the harmless “commensal” bacteria that protect the ear from other infections.
EARTH suffered from quite a fever around 640 million years ago, with the climate yo-yoing rapidly between severe glaciations and warm periods. This contradicts the Snowball Earth theory that the planet was locked in a relentless and complete glaciation for tens of millions of years. Philip Allen from Imperial College London and colleagues studied chemical weathering in sedimentary rocks between 630 and 640 million years old, exposed in Oman. Sunshine and rain make some minerals in rocks decompose, but not others. By measuring the ratio of weathered to unweathered minerals, Allen’s team was able to identify glacial periods – when very little weathering occurred – and warm ones, which showed strong weathering (Geology, vol 35, p 299). The changes from hot to cold happened too quickly for oceans to have frozen over as the Snowball Earth theory predicts, says Allen.
Protein key to long-life platelets WITHOUT platelets, blood doesn’t clot and wounds don’t heal. Transfusions of platelets save many lives, but platelets have a shelf life of only a few days. There might soon be a way to extend that, however. David Huang and Benjamin Kile of the Walter and Eliza Hall Institute in Melbourne, Australia, have discovered that the lifespan of platelets is dictated by the levels of a protein called Bcl-xL, which dwindle as platelets age (Cell, vol 128, p 1173). Bcl-xL works by blocking the action of another protein called Bak, which would otherwise trigger programmed cell death. The researchers are now searching compounds that increase Bcl-xL levels, mimic it, or block Bak, in order to prolong platelet lifespan. 31 March 2007 | NewScientist | 17
26/3/07 4:40:52 pm