The BA Science News Digest - 20 October 2006
This week, Darwin’s entire works became available online, evidence was published indicating facial expressions are hereditary and another reason to keep our weight down became apparent. Plus, element 118 made a brief appearance and other scientists used an invisibility cloak to make things disappear.
Anyone with an interest in Charles Darwin and his theory on the evolution of life, can now access his entire works at http://darwin-online.org.uk. The Guardian reported that, for the first time, this collection brings together Darwin’s breathtaking range of writing and images. Containing 50,000 pages of searchable text, and tens of thousands of images, this site includes previously unpublished manuscripts, as well as his famous works The Origin of Species and The Descent of Man. The site even makes available diaries and the original notebook documenting Darwin’s observations from his five-year voyage aboard the HMS Beagle.
One of Darwin’s proposals was that facial expressions are innate. New evidence reported by BBC News this week indicates that they may indeed be hereditary. Israeli researchers recruited 21 volunteers who had been blind since birth, asking them to recount experiences of when they were happy, sad, angry and disgusted, as well as provoking concentration and reactions of surprise. At the same time, the researchers monitored the mannerisms the volunteers displayed and compared them to those of their relatives. The results showed that, even though the blind participants had never seen their relatives’ faces before, the expressions they displayed were remarkably similar, particularly for the negative emotions.
The Daily Telegraph provided us with another reason to avoid gaining extra pounds, reporting that putting on weight lowers your intelligence. The discovery, made by French scientists, followed a five-year study involving more than 2,200 adults aged between 32 and 62. Participants were set four mental ability tests. The researchers found that 56 per cent of words in a vocabulary test were remembered by people with a Body Mass Index (BMI) of 20 or less, whereas those who were clinically overweight, and had a BMI of 30 or more, could recall only 44 per cent. Following a retest five years later, those participants who were of a healthy weight retained their level of recall. However, the recall of obese subjects dropped to 37.5 per cent. It was suggested that the cognitive decline observed in obese people may be due to brain cell damage caused by hormones secreted from fat cells, or by the thickening and hardening of cerebral blood vessels.
The Daily Telegraph also reported that lack of sleep may be a contributing factor in the rise of obesity amongst children. In a review of published studies, a scientist from the University of Bristol said that lack of sleep in 30-month old infants was linked to an increase in obesity at the age of seven. He also referred to a study in which the hormone ghrelin, released by the stomach to signal hunger, was at a 15 per cent higher level in people who only slept for five hours a night, compared with those who had eight hours.
And if you’re a fan of the all-night party be warned: lack of sleep may lower the responsiveness of your hippocampus and reduce your ability to remember new things, reported Science online. In a study conducted by neuroscientists at Havard University, two groups of college students were shown a series of 30 words. One group had slept normally the night before, the other had stayed awake. Two days later, the students were tested for their recall of the words and the researchers found that the sleep-deprived group remembered 40 per cent fewer words overall, although the emotional content of the words made a big difference; negative words were much better remembered. To investigate how the sleep deprivation interferes with memory mechanisms in the brain, the scientists then monitored brain activity in another two groups of students. They performed functional magnetic resonance imaging while students viewed emotionally neutral photographs. Those students who were sleep-deprived showed lower activity in their hippocampus compared to the well-rested group.
New research from Canada suggests that people’s ideas of nature and nuture can have a direct influence on their behaviour, reported the Times. Scientists discovered that women do better at maths tests when told that female underachievement has a social cause, than when they’re told it’s due to genetic factors. According to Steven Heine, one of the researchers, “The findings suggest that people tend to accept genetic explanations as if they’re more powerful or irrevocable, which can lead to self- fulfilling prophecies”. His colleague highlighted the implications that this could have when simplified genetic explanations were reported for conditions such as obesity.
It was a week of ups and downs in the plant and animal kingdoms...
According to researchers from the Zoological Society of London, less than 400 hippopotamuses remain in the Democratic Republic of Congo as a result of poaching by militia. They fear the population may become extinct within a few months if no action is taken, reported BBC News.
More positive news came with the discovery of 30 new species of orchid in the tropical rainforests of Papua New Guinea. The Times reported that the discoveries were made during a series of exhibitions organised by the WWF to catalogue the area’s floral diversity and were particularly welcome since around 70 species have become extinct in the forests of neighbouring Indonesia due to illegal logging. Meanwhile, scientists have been fascinated by discoveries of highly diverse coral and fish species in the Indonesian archipelago, reported BBC News, and the Times announced that a thirty-five year decline in the number of farmland birds has been halted.
The Environment Agency published a report in which it warned that groundwater supplies across Britain are steadily becoming polluted and unusable. Poor water quality has already resulted in the closure of 146 groundwater sources in the past 30 years, with the loss of enough water to supply nearly 3 million people everyday, reported the Guardian. Increased urbanisation and pollution is now putting supplies at greater risk and contamination from pesticides, fertilisers, fuels and solvents has been detected. The latest tests also revealed traces of anti-bacterial drugs that might kill off microbes important for the breakdown of pollutants.
Russian and US scientists claimed to have made an element with 118 protons in its nucleus, which is new to both nature and the laboratory, reported BBC News. The element was made by colliding calcium with a target made from californium. The scientists say they observed three atoms but, as predicted for super-heavy isotopes, they rapidly decayed into lighter elements, and were detected for only 0.9 milliseconds.
This week a competition will take place that NASA hopes will help spur the development of space elevator technology. It is proposed that space elevators, consisting of 60,000 mile long tethers and a climbing robot, will one day be able to send humans and other cargo into space cheaply. Two challenges, set up by the space agency and first held last year, will test some early prototypes. There were no winners for either The Beam Power Challenge or the Tether Challenge last year, but hopes are high for this year’s contest, which takes place in New Mexico, reported New Scientist.
And finally…
If you’re a fan of Star Trek, you’ll be well-acquainted with cloaking devices or, if Harry Potter is more your thing, invisibility cloaks. Well, a team in America has now successfully demonstrated the world’s first such device, reported the Guardian. Just five months after it was proven to be theoretically possible to make an object disappear from sight without breaking the laws of physics, the idea has been put to the test. The current device is rather small at just 13cm wide but scientists believe devices big enough to hide entire vehicles from radar may only be a matter of years away. The cloak uses newly developed “metamaterials” which, in the current experiment, deflected a beam of microwaves (the same radiation used for radar) past the object, such that it was not reflected in the usual way but flowed around the object like water moving around an obstacle. Much finer metamaterials would be needed to cloak objects from visible light as these waves are less than one thousandth of a millimetre across, compared to 3cm long microwaves.
So it seems Harry’s invisibility cloak is still a long way off.
Anyone with an interest in Charles Darwin and his theory on the evolution of life, can now access his entire works at http://darwin-online.org.uk. The Guardian reported that, for the first time, this collection brings together Darwin’s breathtaking range of writing and images. Containing 50,000 pages of searchable text, and tens of thousands of images, this site includes previously unpublished manuscripts, as well as his famous works The Origin of Species and The Descent of Man. The site even makes available diaries and the original notebook documenting Darwin’s observations from his five-year voyage aboard the HMS Beagle.
One of Darwin’s proposals was that facial expressions are innate. New evidence reported by BBC News this week indicates that they may indeed be hereditary. Israeli researchers recruited 21 volunteers who had been blind since birth, asking them to recount experiences of when they were happy, sad, angry and disgusted, as well as provoking concentration and reactions of surprise. At the same time, the researchers monitored the mannerisms the volunteers displayed and compared them to those of their relatives. The results showed that, even though the blind participants had never seen their relatives’ faces before, the expressions they displayed were remarkably similar, particularly for the negative emotions.
The Daily Telegraph provided us with another reason to avoid gaining extra pounds, reporting that putting on weight lowers your intelligence. The discovery, made by French scientists, followed a five-year study involving more than 2,200 adults aged between 32 and 62. Participants were set four mental ability tests. The researchers found that 56 per cent of words in a vocabulary test were remembered by people with a Body Mass Index (BMI) of 20 or less, whereas those who were clinically overweight, and had a BMI of 30 or more, could recall only 44 per cent. Following a retest five years later, those participants who were of a healthy weight retained their level of recall. However, the recall of obese subjects dropped to 37.5 per cent. It was suggested that the cognitive decline observed in obese people may be due to brain cell damage caused by hormones secreted from fat cells, or by the thickening and hardening of cerebral blood vessels.
The Daily Telegraph also reported that lack of sleep may be a contributing factor in the rise of obesity amongst children. In a review of published studies, a scientist from the University of Bristol said that lack of sleep in 30-month old infants was linked to an increase in obesity at the age of seven. He also referred to a study in which the hormone ghrelin, released by the stomach to signal hunger, was at a 15 per cent higher level in people who only slept for five hours a night, compared with those who had eight hours.
And if you’re a fan of the all-night party be warned: lack of sleep may lower the responsiveness of your hippocampus and reduce your ability to remember new things, reported Science online. In a study conducted by neuroscientists at Havard University, two groups of college students were shown a series of 30 words. One group had slept normally the night before, the other had stayed awake. Two days later, the students were tested for their recall of the words and the researchers found that the sleep-deprived group remembered 40 per cent fewer words overall, although the emotional content of the words made a big difference; negative words were much better remembered. To investigate how the sleep deprivation interferes with memory mechanisms in the brain, the scientists then monitored brain activity in another two groups of students. They performed functional magnetic resonance imaging while students viewed emotionally neutral photographs. Those students who were sleep-deprived showed lower activity in their hippocampus compared to the well-rested group.
New research from Canada suggests that people’s ideas of nature and nuture can have a direct influence on their behaviour, reported the Times. Scientists discovered that women do better at maths tests when told that female underachievement has a social cause, than when they’re told it’s due to genetic factors. According to Steven Heine, one of the researchers, “The findings suggest that people tend to accept genetic explanations as if they’re more powerful or irrevocable, which can lead to self- fulfilling prophecies”. His colleague highlighted the implications that this could have when simplified genetic explanations were reported for conditions such as obesity.
It was a week of ups and downs in the plant and animal kingdoms...
According to researchers from the Zoological Society of London, less than 400 hippopotamuses remain in the Democratic Republic of Congo as a result of poaching by militia. They fear the population may become extinct within a few months if no action is taken, reported BBC News.
More positive news came with the discovery of 30 new species of orchid in the tropical rainforests of Papua New Guinea. The Times reported that the discoveries were made during a series of exhibitions organised by the WWF to catalogue the area’s floral diversity and were particularly welcome since around 70 species have become extinct in the forests of neighbouring Indonesia due to illegal logging. Meanwhile, scientists have been fascinated by discoveries of highly diverse coral and fish species in the Indonesian archipelago, reported BBC News, and the Times announced that a thirty-five year decline in the number of farmland birds has been halted.
The Environment Agency published a report in which it warned that groundwater supplies across Britain are steadily becoming polluted and unusable. Poor water quality has already resulted in the closure of 146 groundwater sources in the past 30 years, with the loss of enough water to supply nearly 3 million people everyday, reported the Guardian. Increased urbanisation and pollution is now putting supplies at greater risk and contamination from pesticides, fertilisers, fuels and solvents has been detected. The latest tests also revealed traces of anti-bacterial drugs that might kill off microbes important for the breakdown of pollutants.
Russian and US scientists claimed to have made an element with 118 protons in its nucleus, which is new to both nature and the laboratory, reported BBC News. The element was made by colliding calcium with a target made from californium. The scientists say they observed three atoms but, as predicted for super-heavy isotopes, they rapidly decayed into lighter elements, and were detected for only 0.9 milliseconds.
This week a competition will take place that NASA hopes will help spur the development of space elevator technology. It is proposed that space elevators, consisting of 60,000 mile long tethers and a climbing robot, will one day be able to send humans and other cargo into space cheaply. Two challenges, set up by the space agency and first held last year, will test some early prototypes. There were no winners for either The Beam Power Challenge or the Tether Challenge last year, but hopes are high for this year’s contest, which takes place in New Mexico, reported New Scientist.
And finally…
If you’re a fan of Star Trek, you’ll be well-acquainted with cloaking devices or, if Harry Potter is more your thing, invisibility cloaks. Well, a team in America has now successfully demonstrated the world’s first such device, reported the Guardian. Just five months after it was proven to be theoretically possible to make an object disappear from sight without breaking the laws of physics, the idea has been put to the test. The current device is rather small at just 13cm wide but scientists believe devices big enough to hide entire vehicles from radar may only be a matter of years away. The cloak uses newly developed “metamaterials” which, in the current experiment, deflected a beam of microwaves (the same radiation used for radar) past the object, such that it was not reflected in the usual way but flowed around the object like water moving around an obstacle. Much finer metamaterials would be needed to cloak objects from visible light as these waves are less than one thousandth of a millimetre across, compared to 3cm long microwaves.
So it seems Harry’s invisibility cloak is still a long way off.
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