the-BA : Science News Digest

Baldness - could pollution be making it worse? (image copyright: istockphoto.com)

In the science news this week: why pot bellies are bad but buttock fat could actually be beneficial, pollution spells bad news for balding men, and the job opportunity of a lifetime...

A team involving more than 100 scientists from eight countries has finally deciphered the genome of one of the world’s oddest creatures – the duck-billed platypus. It is such a bizarre creature that when it was first relayed to England in 1799 the British Museum’s keeper of natural history deemed it to be an elaborate hoax. Subsequent investigation of its anatomy and behaviour by zoologists showed it to be one of the strangest anomalies in the animal kingdom.

The new analysis of the furry, egg-laying, venomous mammal’s genetic code has revealed that its genes reflect this, with a patchwork of avian, reptilian and mammalian features.

The platypus is a member of the monotreme group of mammals (that lay eggs), an early branch of the mammal family that diverged from other mammals about 166 million years ago, and of which there are just a few living species. ‘The fascinating mix of features in the platypus genome provides many clues to the function and evolution of all mammalian genomes,’ commented Washington University researcher Richard Wilson, one of the lead authors of the study published in Nature.

You can read more about the scientists’ discoveries in the Independent, including evidence that suggests the common ancestor of all mammals may have had sex-determining chromosomes that were more like those of modern-day birds.
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Another news item in the Independent warned that insects in the tropics could be the first species to become extinct due to global warming, and that this could have serious repercussions for tropical habitats since insects are such a crucial part of the ecosystem. Just a 1-2 degree celcius rise in average temperatures in the tropics could have a devastating effect on a wide variety of important insects because they are already living at the limit of their temperature range.

For the study published in Proceedings of the National Academy of Sciences, US scientists studied temperature changes between 1950 and 2000, and compared them to species ‘fitness’ indicators such as population growth rate and physical performance.

One of the co-authors, Dr Joshua Tewksbury of Washington University explained why tropical insects are at risk: ‘The direct effects of climate change on the organisms we studies appear to depend a lot more on the organisms’ flexibility than on the amount of warming predicted for where they live. The tropical species in our data were mostly thermal specialists, meaning that their current climate is nearly ideal and any temperature increases will spell trouble for them.’

‘Our calculations show that [tropical species] will be harmed by rising temperatures more than would species in cold climates,’ added co-author Professor Curtis Deutsch of the University of California. ‘Unfortunately, the tropics also hold the large majority of species on the planet.’
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One species that seems to be coping well with climate change (at least so far) is the great tit. The Telegraph reported that a 47-year study of the birds in Wytham Woods, near Oxford, has revealed that they have modified their breeding schedule over the years to adapt.

As a result of warmer spring temperatures, caterpillars become abundant two weeks earlier in the season compared to when the study began. In response, to enable them to profit from this food source, the birds also lay their eggs on average two weeks earlier.

However, Professor Ben Sheldon, senior author of the report published in Science, says little is known about the basis of this sort of behavioural adaptability. Nor is it understood why it can vary within species – a recent study of Dutch great tits ‘found a much greater variation in flexibility between individual birds’, compared to female British great tits. It’s not known if the tits will be able to keep up with further climate changes.
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The Office for National Statistics released figures this week that show Britons are becoming greener in terms of waste disposal, but less so with our transport habits.

Recycling went up by 27 per cent between 2002 and 2006, and we’re also using public transport more. However, air travel has also increased ‘substantially’, reported the Guardian, with a rise in the number of flights at all major UK airports between 2001 and 2006, and a two-fold increase in the number of passengers using regional airports such as Liverpool, Bristol and Southampton. Car ownership and usage has also gone up, with the exceptions of London and the East Midlands, where usage dropped by 2 and 7 per cent, respectively. These drops were both accompanied by substantial rises in the use of public transport.
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For a better working environment, add some greenery. A study conducted by the Agricultural University of Norway has found that the more plants visible from workers’ desks there are, the lower the level of self-reported sick leave.

Researcher Professor Grete Patil said there were likely to be several explanations for the results: ‘Possibly the most straightforward is that plants and the microbes in the soil are good at removing volatile, organic compounds that can affect health. There could also be a psychological explanation in that people believe plants are healthier and are likely to evaluate their own health more optimistically.’

The Telegraph reported that this adds to a growing body of evidence suggesting plants in the working environment can offer a beneficial health effect. Another study from researchers at Washington State University looked at the performance of workers set a mundane computer test requiring 20 to 30 minutes of concentration. Researchers found that those working alongside plants had 12 per cent better reaction times than those in a plant-free zone, and also had reduced stress, lower blood pressure and less mental fatigue. Another Norwegian study found plants appeared to reduce other health issues among office workers, such as dry throats and skin, coughs and headaches.
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95 per cent of baldness is known to be heritary. It affects almost 40 per cent of men and women by the age of 35, beginning in some people as early as their teens. Now, new research has found that environmental factors are also important, linking the onset of balding to things such as air pollution and smoking.

The work published in the Journal of Investigative Dermatology looked at hair follicles removed from balding men. Scientists noticed that oxidative stress, which is worsened by the effects of smoking and air pollution, had disrupted the process of hair growth.

'We think any pollutant that can get into the bloodstream or into the skin and into the hair follicle could cause some stress to it and impair the ability of the hair to make a fibre,’ Professor Mike Philpott of Queen Mary University London told the Telegraph. ‘There are a whole host of carcinogens and toxins in the environment that could trigger this. It suggests that if you stop smoking or live in an area with less air pollution, you may be less predisposed to hair loss.’
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Not all body fat is equal, according to a Harvard Medical Schools study that contrasted subcutaneous fat (under the skin) with visceral fat (which is wrapped around organs). The new research suggests that the former, particularly that on the buttocks, may actually help reduce the risk of developing type 2 diabetes, whereas increased fat around the organs raises the risk of ill heath.

Conducting their study in mice, the scientists transplanted fat from one part of the animal’s body to the other. Whereas moving abdominal visceral fat had no effect, moving subcutaneous fat to the abdominal area resulted in a drop in body weight and fat mass. The animals also demonstrated reduced blood sugar levels and increased responsiveness to insulin (the hormone that regulates the body’s blood sugar and to which the body becomes unresponsive when type 2 diabetes develops).

'The surprising thing was that it wasn’t where the fat was located, it was the kind of fat that was the most important variable,’ said lead researcher Professor Ronald Khan. ‘Even more surprising, it wasn’t that abdominal fat was exerting negative effects, but that subcutaneous fat was producing a good effect.’ This may be because subcutaneous fat is producing the metabolism-boosting hormones known as adipokines.

However, Dr David Haslam of the National Obesity Forum told BBC News weight control and maintaining a healthy lifestyle were still important in light of the study, as a balanced diet and exercise would overwhelmingly impact on visceral, and not subcutaneous fat levels. He said it cast doubts, though, on the usefulness of Body Mass Index (BMI) for assessing someone as having a healthy weight or not because the calculation doesn’t differentiate between different fat types.
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BBC News also reported that scientists from Imperial College London have discovered a gene sequence that could explain why people with Indian ancestry may be more prone to weight problems.

While Indian Asians comprise 25 per cent of the world’s population, they experience particularly high levels of obesity and it is predicted they will account for 40 per cent of global cardiovascular disease by 2020. The Nature Genetics study found that a gene sequence associated with a 2cm bigger waist, 2kg weight gain and a tendency to become insulin-resistant, is carried by 50 per cent of the population and is a third more common in Indian Asians. The sequence possibly influences the MC4R gene that it is located close to, which is involved in energy regulation.

Lead researcher Professor Jasper Kooner said: ‘A better understanding of the genes behind problems such as diabetes and cardiovascular disease means that we will be in a good position to identify people whose genetic inheritance makes them most susceptible.

'We can’t change their genetic inheritance. But we can focus on preventative measures, including life-style factors such as diet and exercise, and identifying new drug targets to help reduce the burden of disease.’
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In other news, New Scientist reported that ‘sea creatures had a thing for bling’. Fossilised creatures known as agglutinated foraminifera have been found coated in microscopic diamonds created by an asteroid impact 65 million years ago.

The single-celled amoeba-like organisms and their latter-day descendents protect themselves by surrounding themselves with sediment grains from the sea floor (creating ‘tests’). While the fossil tests were mostly composed of common minerals such as quartz, the foraminifera were found to preferentially incorporate heavy grains. These included diamonds derived both from asteroid carbon and from terrestrial graphite rock altered by the extreme pressure and temperature caused by the asteroid impact, and extraterrestrial grains rich in metals such as nickel and cobalt.
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Scientists have conducted preliminary work that suggests fungi could be a practical way of cleaning up battlefields contaminated with depleted uranium particles and dust. The hazardous radioactive material added to weapons to increase their ability to penetrate targets can persist in the environment for decades. But now, a team from the University of Dundee have discovered that common fungi can grow on the material and lock it away, changing it from a chemically unstable and reactive form to one inaccessible to biological organisms and unlikely to leach out from the soil to contaminate water.

It offers the potential for low-tech clean ups of contaminated areas, using moisture and nutrients to help soil fungi flourish. However, the uranium would still be toxic if eaten and the team have yet to devise a practical way to collect and dispose of the trapped uranium, wrote New Scientist.
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An image of a leaf that was sent for auction at Sotheby’s could be the world’s oldest photograph, possibly more than 200 years old, reported the Times. It was created by laying a leaf on a sheet of light-sensitive paper and exposing it to sunlight (and as such is correctly known as a photogenic drawing).

The attribution of the image to Fox Talbot, the first person to create a reproducible photographic negative, has now come into question. Dr Larry Schaaf, an authority on Talbot, believes it is not one of his and that the presence of an initial ‘W’ means it could be the work of Thomas Wedgewood, who experimented with photography in the 1790s. It was thought that Wedgewood was unable to fix the images he created using light-sensitive paper.

The leaf image will now undergo further investigation, as will two images from the same album that were previously sold to the J. Paul Getty Museum and the Metropolitan Museum of Art. Tests will be conducted to determine the age of the paper and identify any chemicals used on it.
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A robotic walker developed by Honda could help elderly and infirm people walk more easily, as well as helping people recovering from muscle wastage to learn to walk again, reported the Times. The device attaches to the user’s hips and can take the strain of their weight, resulting in an apparent weight drop of almost three stone. Volunteers who tested the walker, including residents of a care home in Japan, reported feeling significantly more light-footed. Researchers hope it will be commercially available in a decade.

'There are sensors and motors on each side and the device is able to understand the angle the user wants to move the leg.’ explained William de Braekeleer of Honda. ‘It gives you the impression of weighing almost 20kg less. The length of the stride is improved – you become more agile. Having used the mechanism for an hour people walked better.’
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And finally…

Here’s a job offer that’s out of this world… the European Space Agency is inviting applications for at least four astronaut positions. The recruitment drive was launched in Britain this week and the application process runs from May 19 to June 16. Britons will still be considered despite the fact that Britain doesn’t fund human spaceflight, instead contributing £200 million a year to the ESA towards robotic space missions. Well-qualified Brits (as well as people from other member states of the agency) are urged to apply after obtaining a medical certificate.

The Guardian reported that successful candidates will need to fit a stringent personality profile, be motivated, flexible, emotionally stable and gregarious, able to work in a team and have good communication and interpersonal skills and that ‘scientists, engineers and test pilots aged between 27 and 37’ are most likely to have the ‘right stuff’.

The competition will be stiff – with up to 50,000 applicants anticipated from around Europe. The whole process is expected to take a year, with two rounds of psychological tests and a thorough medical for those who pass the first stage, and an interview for the 40 or so that make it to the last stage.

Check out the recruitment website to apply.