Science News Digest - 17 July 2009
In the science news this week, how crafty cats manipulate their owners, new superfibres that could revolutionise our clothing and finally, sixth time lucky for the launch of space shuttle Endeavour.
Cat got your tongue?
Cats have a reputation for getting what they want, but now researchers have pinpointed an element of their purr that’s especially hard to resist.
This component is a high-pitched ‘cry’ that’s embedded into the low tones of a purr. Being both pleasant and plaintive, this ‘feed me’ cry is designed to elicit a sense of urgency in people.
The muse for the work is Pepo, the pet of Karen McComb, a biologist at the University of Sussex. She noticed he was very adept at waking her up every morning: “I wondered why this purring sounded so annoying and was so difficult to ignore” .
She and her research team examined purrs from cats after food, and also non-soliciting purrs, and people’s responses to these. They found people recognised the food-seeking calls more urgent and less pleasant.
By separating the components of the soliciting purrs, the team also found that when the high-pitched element was removed, the urgency ratings decreased significantly.
This may be designed to tap-into our nature to care for offspring. “The embedding of a cry within a call that we normally associate with contentment is quite a subtle means of eliciting a response” commented Dr McComb.
For more information visit The Times
DNA all the way
Doctors are to get more training in DNA-based medicine, so recent scientific developments can be translated into benefits for patients, reports the Times.
The overhaul in specialist training is to prepare the NHS for a revolution in DNA-based, more personalised, medicine.
The last genetics syllabus for medical students and junior doctors was put-together in 2006, but large advances have been made since then. The current focus is on rare disorders caused by mutations in single genes, such as cystic fibrosis or Huntington’s disease.
But more recent work has shown that identifying any of hundreds of DNA variants can tell doctors about more common conditions such as heart disease, cancer and rheumatoid arthritis. Singly these have only small effects, but combined can create a significantly raised risk.
Information about whether or not a drug is likely to be effective - or what the safe dose is - can also be gleaned by an individual’s genetic profile.
The falling costs of reading DNA is another factor making this move timely.
“It definitely needs to go into the main syllabus now, absolutely” stressed Professor Peter Farndon, director of the National Genetics Education and Development Centre. “Suppose there’s a set of eight DNA variants that predispose a woman to a high risk of breast cancer. Even though she has no family history, you might target her for screening much sooner than the recommended age”.
Find out more at The Times
When is a calorie not a calorie?
It’s constantly drummed into us: stick within the daily 2000 calories for women and 2500 for men and you can eat what you like and stay slim. But this social creed could be leasing us astray - say a small band of researchers - and calorie estimates on packaging could over or underestimate energy by as much as a quarter as reported in New Scientist.
The current labeling system assessed energy content by burning small samples of food and calculating the heat lost. The proportion of this that’s used by the body was then deduced by subtracting the amount lost through faeces, urea, amonia and other organic acids.
But the human body doesn’t incinerate; it digests.
Different foods take different amounts of energy to break down which can reduce the net energy gain by 5 to 25 per cent. For example fibre is more resistant to mechanical and chemical digestion than other carbohydrates, and an energy cut is taken by gut microbes before we get our share. Protein also requires energy to be broken down.
The way food is cooked and how soft it is also significantly affects the calories absorbed. However none of these factors are reflected in the food labelling system.
However the UN Food and Agriculture Organization decided in 2002 not to change food labelling standards to reflect the cost of digestion, concluding a change would be more trouble than it’s worth.
Some disagree. Geoffrey Livesey, an independent nutritionist based in Norfolk, believes bringing food labels up to date with research will give the consumer the information to make the best choices: “The public should be able to apply the science. If you’re not following the science you’re following something else”.
Fibre Space
A new generation of fibers could one day allow our clothes to take our holiday snaps, or to be the eyes in the back of our heads.
Researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, USA have developed the new ‘multimaterial’ fibers, which are flexible and translucent. These can turn incoming light waves into images.
The fibers consist of an array of metal electrodes connected to a semiconductor, inside an insulating polymer sheath. Light is detected by the semiconductor layer, which then relays signals to a microprocessor. This combines signals from an array of fibers. Finally an image is produced by visualization software.
A big advantage of this method is that it disposes of the need for lenses, which are easily damaged. Images can also be captured from any part of the entire length of the fiber.
The MIT researchers demonstrated the technology by placing a web of filaments in front of a smiley face drawing to create an image on a video screen. They also wove the multimaterial fibers into an optical fabric – a flexible camera – that could serve as stealth wallpaper or be incorporated into a soldier’s helmet to give them 360° vision.
“It should inspire others to find ways to integrate nanoscale components” commented materials scientist Rod Ruoff of the University of Texas, Austin.
Read more at Science Now!
Nice day for a launch
NASA finally liked the look of the weather this week, as the space shuttle Endeavour was launched at the sixth attempt. Fuel leaks had also caused earlier efforts at the Kennedy Space Centre in Florida to be called off, reports the BBC.
In cosmic parking problems, if the shuttle hadn’t departed by Thursday, it would have had to wait till the end of the month to make way for a Russian cargo ship.
“The weather is finally co-operating so it is now time to fly” said launch director Pete Nickolenko. “Persistence pays off, good luck and God speed”.
Endeavour carries six Americans and one Canadian to the International Space Station, taking the crew to a record 13 for the outpost.
The astronauts will undertake five spacewalks, including one to install a new Japanese laboratory complex. They also plan to fit new batteries to one of the station’s power-generating solar arrays and perform other maintenance tasks.
A collaboration between 16 nations, the space station is now around the size of a four bed-roomed house, and has been under construction for more than a decade.
Cat got your tongue?
Cats have a reputation for getting what they want, but now researchers have pinpointed an element of their purr that’s especially hard to resist.
This component is a high-pitched ‘cry’ that’s embedded into the low tones of a purr. Being both pleasant and plaintive, this ‘feed me’ cry is designed to elicit a sense of urgency in people.
The muse for the work is Pepo, the pet of Karen McComb, a biologist at the University of Sussex. She noticed he was very adept at waking her up every morning: “I wondered why this purring sounded so annoying and was so difficult to ignore” .
She and her research team examined purrs from cats after food, and also non-soliciting purrs, and people’s responses to these. They found people recognised the food-seeking calls more urgent and less pleasant.
By separating the components of the soliciting purrs, the team also found that when the high-pitched element was removed, the urgency ratings decreased significantly.
This may be designed to tap-into our nature to care for offspring. “The embedding of a cry within a call that we normally associate with contentment is quite a subtle means of eliciting a response” commented Dr McComb.
For more information visit The Times
DNA all the way
Doctors are to get more training in DNA-based medicine, so recent scientific developments can be translated into benefits for patients, reports the Times.
The overhaul in specialist training is to prepare the NHS for a revolution in DNA-based, more personalised, medicine.
The last genetics syllabus for medical students and junior doctors was put-together in 2006, but large advances have been made since then. The current focus is on rare disorders caused by mutations in single genes, such as cystic fibrosis or Huntington’s disease.
But more recent work has shown that identifying any of hundreds of DNA variants can tell doctors about more common conditions such as heart disease, cancer and rheumatoid arthritis. Singly these have only small effects, but combined can create a significantly raised risk.
Information about whether or not a drug is likely to be effective - or what the safe dose is - can also be gleaned by an individual’s genetic profile.
The falling costs of reading DNA is another factor making this move timely.
“It definitely needs to go into the main syllabus now, absolutely” stressed Professor Peter Farndon, director of the National Genetics Education and Development Centre. “Suppose there’s a set of eight DNA variants that predispose a woman to a high risk of breast cancer. Even though she has no family history, you might target her for screening much sooner than the recommended age”.
Find out more at The Times
When is a calorie not a calorie?
It’s constantly drummed into us: stick within the daily 2000 calories for women and 2500 for men and you can eat what you like and stay slim. But this social creed could be leasing us astray - say a small band of researchers - and calorie estimates on packaging could over or underestimate energy by as much as a quarter as reported in New Scientist.
The current labeling system assessed energy content by burning small samples of food and calculating the heat lost. The proportion of this that’s used by the body was then deduced by subtracting the amount lost through faeces, urea, amonia and other organic acids.
But the human body doesn’t incinerate; it digests.
Different foods take different amounts of energy to break down which can reduce the net energy gain by 5 to 25 per cent. For example fibre is more resistant to mechanical and chemical digestion than other carbohydrates, and an energy cut is taken by gut microbes before we get our share. Protein also requires energy to be broken down.
The way food is cooked and how soft it is also significantly affects the calories absorbed. However none of these factors are reflected in the food labelling system.
However the UN Food and Agriculture Organization decided in 2002 not to change food labelling standards to reflect the cost of digestion, concluding a change would be more trouble than it’s worth.
Some disagree. Geoffrey Livesey, an independent nutritionist based in Norfolk, believes bringing food labels up to date with research will give the consumer the information to make the best choices: “The public should be able to apply the science. If you’re not following the science you’re following something else”.
Fibre Space
A new generation of fibers could one day allow our clothes to take our holiday snaps, or to be the eyes in the back of our heads.
Researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, USA have developed the new ‘multimaterial’ fibers, which are flexible and translucent. These can turn incoming light waves into images.
The fibers consist of an array of metal electrodes connected to a semiconductor, inside an insulating polymer sheath. Light is detected by the semiconductor layer, which then relays signals to a microprocessor. This combines signals from an array of fibers. Finally an image is produced by visualization software.
A big advantage of this method is that it disposes of the need for lenses, which are easily damaged. Images can also be captured from any part of the entire length of the fiber.
The MIT researchers demonstrated the technology by placing a web of filaments in front of a smiley face drawing to create an image on a video screen. They also wove the multimaterial fibers into an optical fabric – a flexible camera – that could serve as stealth wallpaper or be incorporated into a soldier’s helmet to give them 360° vision.
“It should inspire others to find ways to integrate nanoscale components” commented materials scientist Rod Ruoff of the University of Texas, Austin.
Read more at Science Now!
Nice day for a launch
NASA finally liked the look of the weather this week, as the space shuttle Endeavour was launched at the sixth attempt. Fuel leaks had also caused earlier efforts at the Kennedy Space Centre in Florida to be called off, reports the BBC.
In cosmic parking problems, if the shuttle hadn’t departed by Thursday, it would have had to wait till the end of the month to make way for a Russian cargo ship.
“The weather is finally co-operating so it is now time to fly” said launch director Pete Nickolenko. “Persistence pays off, good luck and God speed”.
Endeavour carries six Americans and one Canadian to the International Space Station, taking the crew to a record 13 for the outpost.
The astronauts will undertake five spacewalks, including one to install a new Japanese laboratory complex. They also plan to fit new batteries to one of the station’s power-generating solar arrays and perform other maintenance tasks.
A collaboration between 16 nations, the space station is now around the size of a four bed-roomed house, and has been under construction for more than a decade.
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