the-BA : Science News Digest

Space (Image copyright: istockphoto.com/Heidi Kristensen)

In the science news this week: researchers come closer to understanding the obesity gene, the source of mystery cosmic rays is solved and a ‘generosity hormone’ is revealed…

Back in April it was reported that scientists had discovered the first clear genetic link to obesity (see the BA Science News Digest – 13 April 2007). Now, New Scientist reports that researchers have moved a step closer to understanding the biological role of the gene and how it influences weight gain.

The version of the FTO gene that is associated with an increased risk of obesity is carried by a large proportion of people. 50 per cent of individuals carried one copy of each FTO variant and had a 30 per cent higher chance of obesity. One in six were found to have a high-risk genetic make-up, carrying two copies of the genetic variant and a 70 per cent increased risk of obesity. They were 3 kg heavier, on average, with 15 per cent more fat.

To help uncover the function of the gene, scientists from the University of Oxford compared the sequence of the gene to others within the human genome. They found that it was most similar to the sequences of a family of proteins that function in the repair and modification of DNA. An artificially synthesized FTO protein was then shown to modify DNA in a test tube, removing chemical markers called methyl groups. This is significant because the removal and addition of DNA methyl groups can switch genes on and off.

Analysis of the brains of mice designed to produce fluorescent versions of the FTO proteins revealed a high concentration of the protein in their hypothalamus’. This region is known to help regulate hunger.

The scientists believe that the FTO protein may therefore be an enzyme which modifies the activity of genes involved in metabolism and fat storage.
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The Guardian reported that NASA-funded scientists have discovered a fifth planet orbiting the star known as 55 Cancri, located 41 light years away in the constellation of Cancer.

The alien world is similar to Saturn and is the first known outside our solar system to orbit entirely within the ‘habitable zone’, the area where the heat from a star is neither too hot nor too cold to support liquid water, which is thought to be necessary for life to exist.

‘This work marks an exciting next step in the search for worlds like our own,’ said Michael Briley, an astronomer at the US National Science Foundation. ‘To go from the first detections of planets around sun-like stars to finding a full-fledged solar system with a planet in a habitable zone in 12 years is a testament to the years of hard work put in by these investigators.’

BBC News added that the astronomers are particularly intrigued by the quintuple planet system’s many similarities to our own Solar System. The star is similar in age and mass to the Sun and the system also includes a gas giant such as Jupiter. And, while they haven’t yet found a rocky planet like Earth or Venus, Professor Geoff Marcy is intrigued by a gap between the distant gas giant and the fourth planet which is much closer to 55 Canri.

‘In that gap, we don't know what there is. Our current technology would be able to detect big planets like Neptune, Saturn and Jupiter,’ he said. ‘We don't see any of them. So if there are any planets there, they must be smaller, the size of the Earth. In fact, it's a little hard to imagine that there's just nothing there in this big gap. So the suggestion is there might be small rocky planets, like Venus, Mars or Earth.’
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In another space-related news story, BBC News announced that scientists have determined that huge black holes are the most likely source of ultra high-energy cosmic rays.

The origin of these fast-moving subatomic particles and nuclei from space has been a mystery since their discovery in 1912. But now observations made by a large collaboration of scientists using the Pierre Auger Observatory in Argentina have revealed that the rays to not originate from evenly distributed directions. Instead, they seem to be coming from parts of the sky where giant black holes are located within galaxies.

It is thought that their super high energies may be the result of acceleration by magnetic fields around the black holes.

The observatory detects the secondary particles created when cosmic ray particles hit the Earth’s atmosphere and has 24 telescopes and 1,600 detectors covering an area about the size of Lancashire.
Read more in the Telegraph.
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If you find the thought of plunging lobsters into boiling water unsavoury, you won’t feel any better following this study which suggests crustaceans can feel pain.

Previous Norwegian research had concluded that the animals’ nervous systems weren’t complex enough to experience pain. But according to the Guardian, an expert in animal behaviour claims his new research shows otherwise.

After daubing acetic acid onto the antennae of 144 prawns, Professor Robert Elwood from Queen’s University, Belfast, observed that they immediately began grooming and rubbing the affected area. He says the response is ‘consistent with an interpretation of pain experience’ and that this sensitivity to pain is likely to be shared by other crustaceans.

However, other scientists who work in pain research disagreed, saying that it could be argued that the shrimps were simply trying to clean their antennae and that, while even a single-cell organism can detect a threatening chemical gradient and retreat from it, this is not sensing pain.
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A fear of felines is instinctive for most mice, but not for a mutant mouse that has been genetically engineered to lack certain nerve cells involved in smell, reported the Independent.

Mice normally show fear responses when they smell a cat, but the mutant mice instead happily and fearlessly approach the potential predators. They are missing glomeruli (nerve cells) from the olfactory bulb at the base of the brain.

The research, led by Professor Hitoshi Sakano at the University of Tokyo, and published in the journal Nature, shows that there are separate sets of glomeruli – those that deal with innate responses, and others with ones that are learnt – since the mutant mice were still able to detect ‘aversive odours’ and could be conditioned to fear the cats’ odours using the remaining glomeruli.
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According to new research, attraction has a lot to do with ego – we find people more attractive when it looks like they are attracted to us.

Whereas most previous studies of facial attractiveness have focused on physical traits, the latest work instead studied the social cues involved. Volunteers were asked to rate the relative attractiveness of pairs of images that were identical except for gaze direction, which was either direct or averted. Four different sets of digital images were assessed - women looking happy, women looking disgusted, men looking happy and men looking disgusted.

The scientists found that, if it looked like a person liked you, the faces with direct gaze were found most attractive. The preference was strongest when the face in the picture was of the opposite sex, the Guardian reported.
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In other research looking at attraction, researchers have discovered women walk less sexily when they are at their most fertile.

The evolutionary psychologist who conducted the study suggests that it could be a subconscious behaviour that evolved so that women could hide their fertility from less appealing men, as movement is visible from a long distance. Only when a woman has allowed a man to get close (and been able to assess whether she would like to have children with him) would close-range signals such as facial expressions and smell come into play.
(Telegraph)
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The face of Tutankhamun, Egypt’s boy-king, has been put on public display for the first time. The mummy has been moved to a climate-controlled case inside his tomb in the Valley of the Kings in an attempt by archaeologists to protect it. The remains were at risk from the heat and humidity in the tomb caused by the large number of tourists visiting each year.
Read more at BBC News.
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Scientists trying to design robots for use as teacher’s aids in nursery schools have successfully overcome one of the major hurdles in the process – designing an automaton that children bond with and accept as a social peer.

While most robots don’t hold a toddler’s attention for long, a prototype ‘social robot’ has been designed by researchers at the University of California, San Diego that has been used in a classroom of toddlers for five months. The social interaction between the children and the robot was found to increase over time, and by the end it was treated like a peer rather than a toy.

The Telegraph reported that whereas the children initially touched the robot on the face, this later changed to careful touches on only the arms and hands, reflecting the way they interact with other children.
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Good news for dandruff sufferers: scientists have cracked the genome of the fungus responsible for those itchy flaking scalps. Ten litres of Malassezia globosa was grown to provide enough DNA to sequence. Researchers hope the genetic information will give vital clues on how to tackle the organism.
Read more in the Telegraph.
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And finally…

Feeling generous? That could be your oxytocin talking; scientists have found that the hormone has a striking impact on the level of people’s generosity.

Professor Paul Zak and colleagues gave either a dose of oxytocin or a placebo to participants before asking them to split a sum of money with a stranger who could reject or accept the division. Strikingly, those given oxytocin offered 80 per cent more money than those who had the placebo. The work has been published in PLoS ONE.

Professor Zak told the Telegraph that people don’t need to worry about unscrupulous salesmen, con men and advertisers abusing the hormone: ‘We have to put a lot up people's noses to get an effect (about two teaspoons worth) - not a lot of oxytocin gets into the brain, so lots needs to be used, so spritzing it around won't have an effect.’

However, some may already be benefiting from the effects of oxytocin – production of the hormone in the body is increased in response to touch, signals of trust from other people, and images that tug at the heart strings – a technique used by some advertising campaigns.

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