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Martian rocks hint at past oxygen
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JPL-Caltech/MSSS/NASA
STONES can talk – if you ask with a laser. Rocks on Mars have yielded direct evidence that the planet had an atmosphere rich in oxygen. Mars is called the Red Planet thanks to iron oxide, or rust, on its surface. In addition to all that iron, NASA’s Curiosity rover has now found manganese oxide in rocks in the Gale crater. “We found 3 per cent of rocks have high manganese oxide content,” Agnès Cousin of the Research Institute in Astrophysics and Planetology in Toulouse, France, told the European Geophysical Union meeting in Vienna, Austria, last week. “That requires abundant water and strongly oxidising conditions, so the atmosphere may have contained much more oxygen than we thought.” The rover used its ChemCam, which fires a laser at rocks and analyses the resulting dust cloud, to identify the compound. Cousin says flowing liquid containing dissolved oxygen may have helped form the manganese oxide deposits, as many are close to where a lake once was. Oxygen breaks up biological molecules, so too much of it might not have been good for early life, says Damien Loizeau of the University of Lyon. “O2 is bad for life as we know it, but we only know life to be able to create large amounts of O2,” he says.
Schizophrenia’s foundations may be laid down in the womb PEOPLE who develop schizophrenia may start life with differently structured brains. The finding adds support to the idea that genetics can play a crucial role in the condition. Schizophrenia is the subject of a fierce nature-versus-nurture debate. While childhood abuse is associated with a raised risk of developing the condition, 108 genes have been implicated, too. Probing the biology of schizophrenia is difficult – brain tissue from people who have it is rarely available to study. Kristen
Brennand of the Icahn School of Medicine at Mount Sinai in New York and her colleagues got around this by taking skin cells from 14 people with schizophrenia, and reprogramming them into stem cells and then neurons. They found that on average these neurons had lower levels of a signalling molecule called miR9, when compared with similar cells developed from people without schizophrenia. The team also found that the “schizophrenic” nerve cells could not migrate as far in a dish. This
discrepancy vanished if levels of miR-9 were artificially restored. The molecule seems to be a master switch for many genes affecting cell migration (Cell, DOI: 10.1016/j.celrep.2016.03.090). Schizophrenia symptoms don’t usually begin until adolescence, but the suspicion is that the condition is caused by problems that begin in the womb but stay silent through childhood. “Even before your child is born the genetics have already started to do their work,” says Brennand. Hulton Archive/Getty
Martian rocks hint at past oxygen
Vampire plant battles in Australia LET the plant wars begin. A parasitic vine that sucks the life out of feral weeds is being billed as a promising new biocontrol agent. Cassytha pubescens, or devil’s twine, is the first native plant to be investigated as a weapon against invasive weeds introduced to Australia by European settlers in the early 1800s. Robert Cirocco of the University of Adelaide has shown that the vine is able to kill all the “major baddies” – gorse, Scotch broom and blackberry – by sticking small suckers to the plants’ stems and extracting water and nutrients. According to Cirocco, the biggest advantage of C. pubescens as a potential biocontrol agent is that it already occurs naturally across large tracts of eastern Australia. As a result, there is little danger that the vine will itself become a menace. It is also far more damaging to alien plants than home-grown ones – perhaps because native plants have co-evolved with it. “These weeds cost us millions of dollars annually to eradicate,” says Cirocco. The work was presented at the Natural Resource Management Science Conference in Adelaide.
Victorians didn’t spot climate change SHE would not have been amused. The signs were there that the world was starting to warm as early as Queen Victoria’s reign – but Victorian scientists missed them. Retreating glaciers and early melting of ice on lakes all began to appear shortly after the industrial revolution. “The signs were there for this period, mainly in Europe and North America,” Victor Venema of the University of Bonn, Germany, told the European Geosciences Union meeting in Vienna, Austria, last week. He re-examined meteorological data recorded between 1850 and
1920 in Europe’s industrialised heartland and North America. Previous estimates of average global temperatures for that period suggested that there was very little, if any, warming. But closer examination of land temperatures indicates that they did rise by around 0.4 °C, says Venema. And freezing and melting dates of ponds and lakes had already shifted by four or five days between 1850 and 1920. “They didn’t have any global data sets, so they might at best have noticed local warming trends,” says Venema.
30 April 2016 | NewScientist | 15
JPL-Caltech/MSSS/NASA
STONES can talk – if you ask with a laser. Rocks on Mars have yielded direct evidence that the planet had an atmosphere rich in oxygen. Mars is called the Red Planet thanks to iron oxide, or rust, on its surface. In addition to all that iron, NASA’s Curiosity rover has now found manganese oxide in rocks in the Gale crater. “We found 3 per cent of rocks have high manganese oxide content,” Agnès Cousin of the Research Institute in Astrophysics and Planetology in Toulouse, France, told the European Geophysical Union meeting in Vienna, Austria, last week. “That requires abundant water and strongly oxidising conditions, so the atmosphere may have contained much more oxygen than we thought.” The rover used its ChemCam, which fires a laser at rocks and analyses the resulting dust cloud, to identify the compound. Cousin says flowing liquid containing dissolved oxygen may have helped form the manganese oxide deposits, as many are close to where a lake once was. Oxygen breaks up biological molecules, so too much of it might not have been good for early life, says Damien Loizeau of the University of Lyon. “O2 is bad for life as we know it, but we only know life to be able to create large amounts of O2,” he says.
Schizophrenia’s foundations may be laid down in the womb PEOPLE who develop schizophrenia may start life with differently structured brains. The finding adds support to the idea that genetics can play a crucial role in the condition. Schizophrenia is the subject of a fierce nature-versus-nurture debate. While childhood abuse is associated with a raised risk of developing the condition, 108 genes have been implicated, too. Probing the biology of schizophrenia is difficult – brain tissue from people who have it is rarely available to study. Kristen
Brennand of the Icahn School of Medicine at Mount Sinai in New York and her colleagues got around this by taking skin cells from 14 people with schizophrenia, and reprogramming them into stem cells and then neurons. They found that on average these neurons had lower levels of a signalling molecule called miR9, when compared with similar cells developed from people without schizophrenia. The team also found that the “schizophrenic” nerve cells could not migrate as far in a dish. This
discrepancy vanished if levels of miR-9 were artificially restored. The molecule seems to be a master switch for many genes affecting cell migration (Cell, DOI: 10.1016/j.celrep.2016.03.090). Schizophrenia symptoms don’t usually begin until adolescence, but the suspicion is that the condition is caused by problems that begin in the womb but stay silent through childhood. “Even before your child is born the genetics have already started to do their work,” says Brennand. Hulton Archive/Getty
Martian rocks hint at past oxygen
Vampire plant battles in Australia LET the plant wars begin. A parasitic vine that sucks the life out of feral weeds is being billed as a promising new biocontrol agent. Cassytha pubescens, or devil’s twine, is the first native plant to be investigated as a weapon against invasive weeds introduced to Australia by European settlers in the early 1800s. Robert Cirocco of the University of Adelaide has shown that the vine is able to kill all the “major baddies” – gorse, Scotch broom and blackberry – by sticking small suckers to the plants’ stems and extracting water and nutrients. According to Cirocco, the biggest advantage of C. pubescens as a potential biocontrol agent is that it already occurs naturally across large tracts of eastern Australia. As a result, there is little danger that the vine will itself become a menace. It is also far more damaging to alien plants than home-grown ones – perhaps because native plants have co-evolved with it. “These weeds cost us millions of dollars annually to eradicate,” says Cirocco. The work was presented at the Natural Resource Management Science Conference in Adelaide.
Victorians didn’t spot climate change SHE would not have been amused. The signs were there that the world was starting to warm as early as Queen Victoria’s reign – but Victorian scientists missed them. Retreating glaciers and early melting of ice on lakes all began to appear shortly after the industrial revolution. “The signs were there for this period, mainly in Europe and North America,” Victor Venema of the University of Bonn, Germany, told the European Geosciences Union meeting in Vienna, Austria, last week. He re-examined meteorological data recorded between 1850 and
1920 in Europe’s industrialised heartland and North America. Previous estimates of average global temperatures for that period suggested that there was very little, if any, warming. But closer examination of land temperatures indicates that they did rise by around 0.4 °C, says Venema. And freezing and melting dates of ponds and lakes had already shifted by four or five days between 1850 and 1920. “They didn’t have any global data sets, so they might at best have noticed local warming trends,” says Venema.
30 April 2016 | NewScientist | 15