the-BA : Science News Digest - 22 February 2008

Angry man (image copyright: istockphoto.com)

In the science news this week: the self-healing rubber that could mean the end to laddered tights, major disease outbreaks are becoming more common and a dinosaur-munching ‘frog from hell’. Plus, why it pays to keep your temper…

Scientists in Paris have developed an amazing ‘self-healing’ rubber, reports Nature News. Behaving like a cross between silly putty and a rubber ball, the material can not only stretch but stick itself back together again if ripped in two.

The material could have all sorts of uses, from adding durability to artificial bones, to offering the potential for unbreakable glass and unchippable paint. But what most excited the Times was the tantalising promise of tights that can mend themselves when laddered.

Professor Ludwik Leibler, one of the inventors from Paris’ Industrial Physics and Chemistry Higher Educational Institution, said: ‘I think it will have all sorts of uses. It’s just a matter of using your imagination.’

Unlike conventional rubber, the elastic substance was created from small molecular groups: fatty acids from vegetable oil. These were reacted with urea (a component of urine) to create nitrogen-containing chemical groups that naturally seek out a partner to link to. If the rubber is cut, this behaviour brings the fatty acids back into contact, allowing them to reform hydrogen bonds – a strong attractive force.

The longer that cut ends of the rubber are held together, the more hydrogen bonds can reform, and this mending can take place as much as a week after the substance is broken.
--------------------

Scientists at the American Association for the Advancement of Science Annual Meeting in Boston provided evidence suggesting city pollution from car exhausts could be causing heart damage. They highlighted the need for more regulation to reduce potentially harmful pollution.

‘In rapidly modernising regions, environmental regulations are frequently avoided in the interest of improving economic growth,’ Matt Campen, of the Lovelace Respiratory Research Institute in Albuquerque, New Mexico, told the Guardian. ‘Thus, the global cardiovascular health burden from air pollution is likely to escalate dramatically over the coming decades.’

Scientist John Incardona, from the National Oceanic and Atmospheric Administration, looked at the effects of molecules found in oil on developing zebrafish hearts. This is a standard model in which to study the effects of chemicals on human hearts. He found that the small PAH (polycyclic aromatic hydrocarbon) molecules, whose potential effects have previously been ignored, were toxic. He believes that the levels of airborne PAHs are high enough when oil is burned to have an effect on humans.

There is also increasing evidence that links smoke from fires and tobacco to heart attacks, cardiovascular disease and clogged arteries.
--------------------

The incidence of major new disease outbreaks affecting humans quadrupled between 1940 and 2004, according to a study of 335 infectious diseases.

Following an investigation of the origins and spread of the diseases, the international research team cites the human encroachment on animal habitats as a major risk factor. It increases the chance of bacteria and viruses crossing the species barrier, as happened with the deadly HIV and Ebola viruses, for example.

‘Our analysis highlights the critical importance of conservation work,’ said Dr Kate Jones, of the Zoological Society of London, first author of the research paper published in Nature. ‘Wild places where there is an increasing growth in human density are where there’s an increasing risk of diseases emerging.’

The work showed that hotspots where future threats are likely to originate are in tropical parts of Africa, Central America and Asia and that conservation efforts and improved disease surveillance should focus there, rather than Western Europe and North America where the resources currently are.

These areas are also at particular risk of ‘zoonotic’ diseases that originate in wild animals, which tend to be the diseases with the potential to sweep through human populations.
(Read more in the Times)
--------------------

Meanwhile, a study produced for the Optimum Population Trust claims the ‘ecological footprint’ of every person in the UK needs to be cut by more than 70 per cent if we are to have any hope of living sustainably.

The report ‘The Sustainability of Human Populations: How many people can live on Earth?’ states the country is so over-populated it could only support 17 million people if it had to provide for them purely from its own resources and even if Britain were carbon neutral it could only support 40 million at the same living standard.

Currently 60 million people live in the UK – a figure that is expected to hit 65 million within 10 years, according to the latest official figures. The report asserts that the rate of population growth means government targets to cut carbon emissions by 60 per cent by 2050 will have little impact on sustainability.

The report predicts that the world could be at war over resources in less than 50 years if the global population continues to grow as expected.
(Read more in the Telegraph)
--------------------

Fans of computer games will be able to interact with the virtual world on a whole new level when a neuro-headset able to interpret and transmit the brain’s electrical activity to a computer goes on sale later this year. It will be the first such computer interface to be used for gaming and will allow the user to manipulate a game or virtual environment naturally and intuitively, using just their thoughts and emotions.
(BBC News)
--------------------

Scientists have identified the fossil of a 70 million-year-old frog that was the size of a beach ball, dubbing it the ‘frog from hell’. Its vast girth makes it the heaviest frog ever known and it may well have fed on young dinosaurs, although its diet would most likely have been insects and lizards.

Researchers say its discovery ‘lends weight to the controversial idea that Madagascar, the Indian subcontinent and South America were linked well into the Late Cretaceous’ as it is related to the Horned frogs previously considered endemic to South America.
(The Telegraph)
--------------------

Other giant creatures – this time still living – have been observed in the deep waters around Antarctica. The voyage for the Collaborative East Antarctic Marine Census, part of ongoing International Polar Year research, revealed huge worms, jellyfish with six-metre long tentacles, and sea spiders the size of dinner plates, as well as other strange-looking creatures.

Many of these were unable to be identified and will now be analysed in labs to see if they are new species. Some of the sea life was to fragile to be moved and so was only filmed.

The aim of the census is to chronicle sea life in Antarctic waters and monitor the effect of environmental changes, including global warming.
(The Guardian)
--------------------

And finally…

A study published in the journal Brain Behavior and Immunity has found that being unable to control and vent anger harms healing.

98 volunteers agreed to subject themselves to a blister wound (ouch!), that was standardised to allow comparison. An American team then monitored its speed of repair, also measuring secretion of the stress hormone cortisol and assessing the participants’ anger control using a standard scale.

When potential confounding factors were taken into account, the researchers observed that people who had low control over their anger expression were 4.2 times more likely to be slow healers, taking more than four days to heal. These individuals were also found to produce more cortisol in response to the mildly stressful blistering process.

The results offer the possibility that relaxation and cognitive therapy could be used to help individuals improve their anger control and help healing. The Telegraph reports that the team plan to test this approach in future work.