the-BA : Science News Digest - 18 September 2007

Will the UK be joining international partners in manned space exploration? A ‘British astronaut’ meets his historic counterparts at the Science Museum London (Image credit: Ron Whitfield)

From chocolate cravings to the UK’s future in space, the BA Festival of Science featured heavily in the news. Read on for some of the week’s big stories.

Clinical geneticists use face shape differences as important clues in the early stages of diagnosis of genetic abnormalities. However, these facial differences are often hard to detect, especially for less experienced doctors, but now non-invasive 3D photography and novel analysis techniques are set to make the facial recognition easier.

Scientists from the UCL Institute of Child Health told the BA Festival of Science how they have developed new computer software that compares the faces of undiagnosed children with those with a diagnosed condition that also affects the development of their face, with a 90 per cent success rate.

The technique is an important addition to the diagnostic toolbag as some conditions are so rare that a clinician might only see a handful of cases over a career and so may not recognise the characteristic facial features, especially if the child being examined is much younger than previous cases or from a different ethnic background.

Professor Peter Hammond, who led the project, said: ‘Delay in diagnosis causes anxiety to parents who need advice on risks to future children. Moreover, delay may defer important medical treatment or behavioural training that could improve the prognosis for affected children.’

The specially written software is based on dense surface modelling techniques developed at UCL and compares the child’s face to groups of individuals with known conditions and selects which syndromes look most similar. In order to do this, extensive collections of 3D face images of children and adults with the same genetic condition had to be gathered, as well as controls or individuals with no known genetic condition. Each image contains 25,000 or so points on a face surface capturing even the most subtle contours in 3D. The images are then converted to a compact form that requires only a 100 or so numeric values to represent each face in the subsequent analysis.

So far the technique has proved fruitful. ‘The technique is currently being applied to over 30 conditions with an underlying genetic abnormality,' said Professor Hammond. 'The discriminatory capability of the approach has proven highly accurate in identifying the characteristic facial features of a variety of genetic conditions.’

Read more here.

If the number of online friends a person has is a measure of how popular they are then most of us should be virtual social butterflies boasting many hundreds if not thousands of e-buddies. However, new research from a team at Sheffield Hallam University has shown that most people have no more close friends on social networking sites such as Facebook and MySpace than they do in the real world.

Previous work has shown that most people typically have about 150 friends but only five of them are considered close. The rest are more casual acquaintances with whom less frequent contact is sufficient to maintain a bond. 150 friends really does seem to be the maximum number a person is capable of maintaining. This isn’t surprising in terms of behavioural ecology - the process of making friends is time and energy expensive, so people have got to be sure that they will reap the benefits later on.

Dr Will Reader, who led the study, explained: ‘What we need is to be absolutely sure that a person is really going to invest in us, is really going to be there for us when we need them.'

The team asked 200 people to fill in an online survey that quizzed them about their online acquaintances – how many friends they had, how close they considered them to be and what proportion they had met face to face. They found that on average 90 per cent of people had met their ‘friends’ face to face and the other 10 per cent were those they had met through close friends.

This is unsurprising as face to face contact is nearly always necessary to establish genuine friendships. ‘People see face to face contact as being absolutely imperative in forming close friendships,’ said Dr Reader. ‘What social network sites can do is decrease the cost of maintaining and forming these social networks because we can post information to multiple people.’

Read more here.

Children that are exposed to high levels of testosterone in the womb are more likely to display autistic traits, Professor Simon Baron-Cohen of the University of Cambridge announced at the BA Festival of Science.

His team studied 235 mothers and their children over eight years. The women’s amniotic fluid was extracted during amniocentesis tests required for other clinical reasons and was analysed for levels of testosterone. Their children were studied at four stages of their early development for clues that they were displaying atypical behaviour, such as lower than average looks to their mother’s face during interaction.

When the children were eight, their parents were given questionnaires designed to work out their Autistic Spectrum Quotient or AQ. This included questions about whether their child preferred social activities to playing alone or whether they were particularly good at recognising numerical patterns, for example on car number plates. These results were then compared to the pre-natal testosterone levels.

Bonnie Auyeng, also of the University of Cambridge, who carried out the study, said: ‘The correlation is not perfect, but foetal testosterone will account for about 20 per cent of the variability in [questionnaire] scores. Although this doesn't sound like a very high number, it is statistically significant.’

No one is sure what causes elevated levels of the hormone and the researchers do not know whether it is the hormone that causes the development of autistic traits or whether it is a by-product of them. The work does provide a biological basis to Professor Baron-Cohen’s hypothesis that autism is a manifestation of extreme masculinity. ‘Children with autism seem to have a very strong exaggeration of the male profile because they have very strong interests in systems like numbers but have difficulties with empathy,’ explained Professor Baron-Cohen.

Read more here.

A scientist from the University of Bristol dispelled the idea that chocoholics are actually psychologically addicted to the popular substance at the BA Festival of Science. For many years the chemical components that make up chocolate have been touted as having ‘mind-altering’ properties but Professor Peter Rogers suggested that it is culture not chemicals that make chocolate the most highly craved food.

Chocolate’s status as a ‘nice but naughty’ treat means that many people try and resist it, but this ultimately only makes it more desirable. Professor Rogers explained: ‘A compelling explanation lies in our ambivalent attitudes towards chocolate - it is highly desired but should be eaten with restraint. Our unfulfilled desire to eat chocolate, resulting from restraint, is thus experienced as craving, which in turn is attributed to “addiction”.’

Chocolate contains chemicals such as serotonin, tryphophan, cannabinoids and phenylethylamine. All of which have been highlighted as being the possible root of a chocolate addiction. However, these chemicals are found in much higher concentrations in other less appealing foods, such as blue cheese and pineapple.

The highest dose of these chemicals is found in dark chocolate but the most popular type is milk, suggesting that ‘it is therefore far more plausible to suggest that a liking for chocolate, and its effects on mood, are due mainly to its principal constituents, sugar and fat.’

Read more here.

Send British astronauts into space, or risk missing out on potential scientific, economic and cultural benefits, was the message from an influential governmental advisory panel at the BA Festival of Science.

The new plan, proposed in a report commissioned by the British National Space Centre, consists of sending four British astronauts to the International Space Station where they would prepare for missions to the Moon and Mars. Two of the four astronauts would depart by 2010. This would require £50 to £75 million of investment over five years. The government needs to decide soon so that positions can be booked on Russian, Chinese or American missions.

The chairman of the BNSC, Professor Frank Close of the University of Oxford, said: ‘Basically it is time to decide - do we lead or do we just follow?’

Government ministers are said to open-minded about the prospect of funding manned space missions, their most ambivalent stance for forty years. Until now the standard line has been an outright refusal to fund any plans on the grounds that sending people into space was too risky to be financially viable. However, the government still spends £207 million a year on space exploration in the form of robotic probes and satellites.

Things are moving quickly in the quest to colonise space, with NASA announcing its plan to build a permanent base on the Moon by 2024. Just last year, fourteen space agencies including Britain signed up to the Global Exploration Strategy, an initiative designed to pave the way for a combined effort in space exploration, although Britain has so far avoided signing up to anything that would require manned space flight.

The report says that a British crew could be instrumental in reversing the current decline in the popularity of science subjects at school and university. ‘The concept of human exploration of space is inspiring and UK involvement could add a level of pride and encourage the young into science and engineering,’ said Professor Close.

A greater involvement in space could also be advantageous to British industry. Professor Ian Crawford of Birkbeck College, University of London, and one of the authors of the report explained: ‘Human space flight is expensive for a reason. It's because it is difficult. And because it is difficult it requires novel and innovative technologies to make progress. The UK would be foolish, I think, to exclude itself, its industry, from participating in these activities.’

Read more here.

Cutting chewing gum out of your child’s hair or trying to scrape it off your shoe could soon be a thing of the past with the advent of the first 'non-stick', biodegradable chewing gum said Professor Terence Cosgrove of the University of Bristol as he demonstrated his new invention at the BA Festival of Science last week.

The new kind of chewing gum, given the working title ‘Clean Gum’, contains an additional polymer that increases the gum’s solubility in water, meaning that it should easily wash away with the rain.

Professor Cosgrove explained: ‘Our gum has a hydrophilic coating, which means that you always get a film of water around the gum and that's one of the reasons why it's easy to remove and in some cases doesn't stick at all.’

The team deposited the new gum on paving stones in various places around north Wales and Bristol after chewing it for twenty minutes. After 24 hours all the Clean Gum had been washed away but the conventional gum stayed put for all eight days of the experiment. It also underwent the all important gum-stuck-in-hair test on the CEO’s daughter. The conventional gum had to be cut out but the Clean Gum eventually came out after washing and combing.

Revolymer, the spin-off company that manufactures the gum, hopes to launch it on the mass market early next year. The gum has already got the thumbs up from gum enthusiasts with it scoring highly in taste, texture and chewiness categories during blind trials. If successful, the gum could potentially save millions of pounds of tax payers’ money. At present, £300 is spent every minute trying to rid the streets of the sticky menace.

Read more here.

Find out about other stories from the BA Festival of Science here.