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China quake forces rethink over hazard maps
BERNARD JAUBERT/PHOTOSHELTER
HEATED car seats may keep your bottom nice and toasty, but beware: if you’re male, they could also be frying your vital equipment. Optimal sperm production requires a temperature 1 to 2 °C below the core body temperature of 37 °C. This is one reason why the testicles hang outside the main part of the body. To test whether heated car seats might be raising scrotal temperatures above this threshold, Andreas Jung at the University of Giessen in Germany and his colleagues fitted temperature sensors to the scrotums of 30 healthy men, who then sat on a heated car seat for 90 minutes. An hour in, and scrotal temperature had already risen to an average of 37.3 °C, with a maximum temperature in one man of 39.7 °C. Men who sat on unheated car seats reached an average scrotal temperature of just 36.7 °C (Fertility and Sterility, vol 90, p 335). Although that’s only a slight increase due to the heated seats, Jung notes that it may nevertheless be enough to damage the sperm production process. Sitting in a car for long periods of time, even without a heated seat, is already known to raise scrotal temperatures. And previous research suggests that couples take longer to conceive if the man drives for more than 3 hours a day. The team did not test the effect of the heated seat on sperm quality or quantity.
www.newscientist.com
Stopping the march of the antibiotic-resistant gut bugs TAKING antibiotics can make us vulnerable to attack by tougher, antibiotic-resistant invaders, leading to nasty stomach bugs and the spread of dangerous infections in hospitals. Now a molecule has been found that could be mixed with antibiotics to thwart these harmful invasions. The gut bacterium vancomycinresistant enterococcus (VRE) has trouble taking root in a healthy intestine, but after a course of antibiotics it can multiply a thousand-fold and spread to the blood. The reason for this was
thought to be that antibiotics kill not only their target bacteria but also harmless gut microbes, freeing up nutrients and niches that allow VRE to thrive. But when Katharina Brandl of the Sloan-Kettering Institute in New York and colleagues treated mice with antibiotics, they found that levels of Reg3g, a protein made by “friendly” bacteria that kill VRE, dropped by 80 per cent. This suggests that a lack of Reg3g is partly to blame for the VRE increase that follows antibiotic treatment.
To see if boosting Reg3g levels could help, Brandl’s team gave mice doses of lipopolysaccharide along with antibiotics. LPS is a molecule found on the surface of some bacteria that stimulates the gut to make Reg3g. These mice ended up with higher levels of Reg3g than mice that just took antibiotics, and they also had fewer VRE colonies – about the same number as mice that had taken no antibiotics (Nature, DOI: 10.1038/nature07250). Brandl suggests giving LPS orally to humans taking antibiotics.
Why quake maps should be redrawn
led to the quake. This shows that although the crust in the region is being compressed very slowly, at around 1 millimetre per year, strain had been building for over 1500 years (Geological Society of America Today, DOI: 10.1130/GSATG18A.1). For Sichuan province, they calculate that the next big earthquake is not due for at least 2000 years. But for other regions with similar mountainous slopes, a large earthquake could be just around the corner. The team has highlighted the edge of the Tibetan plateau as one such region. Clark Burchfiel at MIT, who is the lead author of the paper, says: “We need to re-evaluate the criteria we use for assessing earthquake hazard.”
RYAN PYLE/CORBIS
Heated seats may be frying sperm
Eco-wine good for the planet GOOD news for eco-conscious wine connoisseurs: a little of what you fancy need not cost the Earth, but only if it’s organic. Valentina Niccolucci and colleagues from the University of Siena, Italy, measured the resources used to grow, package and distribute wine made from Sangiovese grapes at two farms in Tuscany 30 kilometres apart. The organic farm used only natural fertilisers and pesticides, and most operations were done by hand, while the other used conventional methods of production. The team worked out the resources needed to support the making of each wine – its “eco-footprint”. A bottle from the organic farm had an eco-footprint of 7.17 square metres, half that of the nonorganic wine with a footprint of 13.98 square metres. This is because the mechanised production used more land and non-recycled glass (Agriculture, Ecosystems and Environment, DOI: 10.1016/j.agee.2008.05.015). Though it’s not clear that organic food is always ecofriendly, the team say wine producers could shift to organic systems to reduce their overall ecological impact.
WHEN more than 65,000 people died in May in a region of China thought to be at a low risk of quakes, geologists realised their hazard maps must have serious shortcomings. Now a coalition of geologists from the Massachusetts Institute of Technology and the Chengdu Institute of Geology and Mineral Resources, Sichuan, say that similar regions may also be in danger and that seismic hazard maps should be redrawn. Using historical, geological and GPS records, the scientists modelled movements in the Earth’s crust that
30 August 2008 | NewScientist | 15
HEATED car seats may keep your bottom nice and toasty, but beware: if you’re male, they could also be frying your vital equipment. Optimal sperm production requires a temperature 1 to 2 °C below the core body temperature of 37 °C. This is one reason why the testicles hang outside the main part of the body. To test whether heated car seats might be raising scrotal temperatures above this threshold, Andreas Jung at the University of Giessen in Germany and his colleagues fitted temperature sensors to the scrotums of 30 healthy men, who then sat on a heated car seat for 90 minutes. An hour in, and scrotal temperature had already risen to an average of 37.3 °C, with a maximum temperature in one man of 39.7 °C. Men who sat on unheated car seats reached an average scrotal temperature of just 36.7 °C (Fertility and Sterility, vol 90, p 335). Although that’s only a slight increase due to the heated seats, Jung notes that it may nevertheless be enough to damage the sperm production process. Sitting in a car for long periods of time, even without a heated seat, is already known to raise scrotal temperatures. And previous research suggests that couples take longer to conceive if the man drives for more than 3 hours a day. The team did not test the effect of the heated seat on sperm quality or quantity.
www.newscientist.com
Stopping the march of the antibiotic-resistant gut bugs TAKING antibiotics can make us vulnerable to attack by tougher, antibiotic-resistant invaders, leading to nasty stomach bugs and the spread of dangerous infections in hospitals. Now a molecule has been found that could be mixed with antibiotics to thwart these harmful invasions. The gut bacterium vancomycinresistant enterococcus (VRE) has trouble taking root in a healthy intestine, but after a course of antibiotics it can multiply a thousand-fold and spread to the blood. The reason for this was
thought to be that antibiotics kill not only their target bacteria but also harmless gut microbes, freeing up nutrients and niches that allow VRE to thrive. But when Katharina Brandl of the Sloan-Kettering Institute in New York and colleagues treated mice with antibiotics, they found that levels of Reg3g, a protein made by “friendly” bacteria that kill VRE, dropped by 80 per cent. This suggests that a lack of Reg3g is partly to blame for the VRE increase that follows antibiotic treatment.
To see if boosting Reg3g levels could help, Brandl’s team gave mice doses of lipopolysaccharide along with antibiotics. LPS is a molecule found on the surface of some bacteria that stimulates the gut to make Reg3g. These mice ended up with higher levels of Reg3g than mice that just took antibiotics, and they also had fewer VRE colonies – about the same number as mice that had taken no antibiotics (Nature, DOI: 10.1038/nature07250). Brandl suggests giving LPS orally to humans taking antibiotics.
Why quake maps should be redrawn
led to the quake. This shows that although the crust in the region is being compressed very slowly, at around 1 millimetre per year, strain had been building for over 1500 years (Geological Society of America Today, DOI: 10.1130/GSATG18A.1). For Sichuan province, they calculate that the next big earthquake is not due for at least 2000 years. But for other regions with similar mountainous slopes, a large earthquake could be just around the corner. The team has highlighted the edge of the Tibetan plateau as one such region. Clark Burchfiel at MIT, who is the lead author of the paper, says: “We need to re-evaluate the criteria we use for assessing earthquake hazard.”
RYAN PYLE/CORBIS
Heated seats may be frying sperm
Eco-wine good for the planet GOOD news for eco-conscious wine connoisseurs: a little of what you fancy need not cost the Earth, but only if it’s organic. Valentina Niccolucci and colleagues from the University of Siena, Italy, measured the resources used to grow, package and distribute wine made from Sangiovese grapes at two farms in Tuscany 30 kilometres apart. The organic farm used only natural fertilisers and pesticides, and most operations were done by hand, while the other used conventional methods of production. The team worked out the resources needed to support the making of each wine – its “eco-footprint”. A bottle from the organic farm had an eco-footprint of 7.17 square metres, half that of the nonorganic wine with a footprint of 13.98 square metres. This is because the mechanised production used more land and non-recycled glass (Agriculture, Ecosystems and Environment, DOI: 10.1016/j.agee.2008.05.015). Though it’s not clear that organic food is always ecofriendly, the team say wine producers could shift to organic systems to reduce their overall ecological impact.
WHEN more than 65,000 people died in May in a region of China thought to be at a low risk of quakes, geologists realised their hazard maps must have serious shortcomings. Now a coalition of geologists from the Massachusetts Institute of Technology and the Chengdu Institute of Geology and Mineral Resources, Sichuan, say that similar regions may also be in danger and that seismic hazard maps should be redrawn. Using historical, geological and GPS records, the scientists modelled movements in the Earth’s crust that
30 August 2008 | NewScientist | 15