the-BA : Science News Digest

Attraction (image copyright: istockphoto.com)

by Berwyn Jones

In the science news this week: scientists create a robot controlled by a blob of rat brain, why taking the pill can attract women to the ‘wrong’ man, and how our brains may become the battlefields of the future. Plus, arsenic is back on the menu…

The Times reports on the increasing number of aquatic dead zones – areas of water where little or no life can be supported.

Aquatic dead zones have increased by a third in just over ten years, with 405 identified last year compared to only 305 in 1995. They now cover an area of around 95,000 square miles, about the size of New Zealand.

Scientists believe that agricultural fertilisers are the main cause of dead zones. Fertilisers contain nutrients such as nitrogen and phosphorus and when these wash into the sea they fertilise huge blooms of algae. When the algae dies it is broken down by bacteria, and this process absorbs oxygen from the water. This leads to vast areas of water with a critical lack of oxygen and what scientists have termed aquatic dead zones.

The lack of oxygen in aquatic dead zones will drive away tens of thousands of marine animals and can even kill them. Scientists believe that aquatic dead zones are on a par with overfishing and habitat destruction as one of the most damaging problems facing sealife.
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British scientists have created a moving robot controlled by a blob of rat brain cells housed in a cabinet, reports the Independent.

The wheeled robot is wirelessly linked to a bundle of rat brain neurons which, by sending signals to the robot, can steer it around objects in its path. Scientists are now trying to ‘teach’ the robot to become familiar with its surroundings.

Professor Kevin Warwick from the University of Reading and leader of the project said: ‘This new research is tremendously exciting as firstly the biological brain controls its own moving robot body, and secondly it will enable us to investigate how the brain learns and memorises its experiences.’
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Advances in neuroscience could lead to our brains being the battlefields of the future, states a new report commissioned by the Defense Intelligence Agency.

Leading scientists have said that developments in neuroscience could have a significant impact on the way future wars are fought. New developments could include drugs that can change and control the behaviour of opposing troops, scanners that could decipher the state of people’s minds, and devices which could boost soldiers’ senses such as hearing and vision.

And it may not be long before the impact of neuroscience is felt. The report highlighted an electronic technique called transcranial direct current stimulation, which uses electrical impulses to interfere with the firing of neurons in the brain and has been shown to delay the ability to lie under interrogation. Evidence has also shown that soldiers have been taking the narcolepsy drugs modafinil and ritalin in order to boost their performance in battle.

(Read more at the Guardian)
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A British study has revealed that taking the pill can skew women’s hormones and attract them to the ‘wrong’ partner. The pill is believed to change the male scent that women find attractive and so attracts them to partners that may be less genetically compatible.

It is believed that women are naturally attracted to men with different immune system genes because of their smell. This is beneficial to reproduction as people with complementary genes and immune systems pass on a wide-ranging set of immune system genes to their child, reducing its vulnerability to infection. Scientists think that the pill may disrupt this process and could be responsible for fertility problems and relationship breakdowns.

Researchers at the University of Liverpool asked 97 women to smell T-shirts worn in bed by men with different patterns of immune system genes. They found that when women started taking the pill, their preference shifted towards the smell of men with similar genes to their own.

(Read more at the Times)
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The Telegraph reports on how four patients have been freed from cancer by a drug that uses the patients’ own immune cells to attack the disease.

In a trial of 38 people with non-Hodgkin's lymphoma, four saw a complete regression of the disease while five had a 50 per cent reduction in their tumours. The results are seen as a big step in the development of immunotherapy, the process of using a patient’s own immune system to fight disease.

One of the most exciting aspects of the research is that the greater the dose of drug, the greater the effect. In the seven people who received the highest dose, two got rid of the cancer completely while five had a 50 per cent reduction.

Earlier this year, in a different immunotherapy process, a skin cancer patient became free of cancer two year after scientists had injected him with billions of his own immune cells. However, this was a very expensive process. What excites scientists about the new drug is that it is much cheaper, and so more likely to form the basis of a large-scale treatment.

Although trials have only been done on patients with blood cancers, it is hoped that the process can be adapted to tackle other cancers in the future.
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The Guardian reports on how British birds are laying their eggs earlier in the year, yet another sign of the impact of climate change.

A study of 30,000 nests has revealed that some birds such as the chaffinch and robin are laying their eggs up to a week earlier than in the 1960s. Scientists are worried that they may eventually breed so early that they are out of sync with their major food sources, such as caterpillars.

The study also shows that drier summers are forcing some birds such as the song thrush to rear fewer chicks, as their staple diet of earthworms is harder to find in dry ground. In general, the population of many of the UK’s farmland and woodland birds is declining, a continuing trend that is beginning to worry scientists greatly.

Dr Mark Avery, conservation director for the RSPB, said: ‘This year's report shows that climate change is with us already and from our gardens to our seas, birds are having to respond rapidly to climate change simply to survive. As often before, birds are acting like the canaries in a mine shaft and giving us early warning of dangerous change.’
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Researchers believe that an increase in the speed of the internet could be achieved by slowing parts of it down.

The internet’s speed is limited not by the information being transported but by the process of routing the information to various destinations. In high-speed telecommunications routes, information travels through fibre optic cables over vast distances. However, as this information comes to the end of its journey, it needs to be separated into its different components. In this process, optical signals must be converted into electrical signals, stored, routed and then converted back into optical signals, and it is this process that limits the speed of the internet.

However, by using the extraordinary properties of metamaterials, scientists hope to slow the optical signals down sufficiently enough so that they do not have to be converted into electrical signals when routed, hence enhancing speed and efficiency.

(Read more at BBC News)
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And finally…

American scientists have isolated a bacterium that fuels itself on arsenic, reports BBC News.

The bacterium is photosynthetic in a similar way to plants, as it turns carbon dioxide into food by using sunlight. However, unlike plants, which use water to complete the process, the bacterium uses arsenic, a substance that is toxic to most other life forms.

The bacterium was found in Mono Lake, California, which is fed by hydrothermal waters that leach out arsenic-containing minerals from the surrounding rocks. Researchers noticed that the bacteria had gathered in small, hot pools forming colourful ‘biofilms’ on the rocks. By controlling the levels of light and arsenic given to the bacterium in a laboratory, they realised that the bacterium needed both to grow.

Scientists believe that this process of producing energy relates back to ancient times, when bacteria were photosynthesising and creating energy before oxygen appeared in the atmosphere.