the-BA : Science News Digest

Sunflowers in bloom (Image copyright: istockphoto.com)

In the science news this week: the ‘caterpillar robot’ that could transform cardiac surgery, Star Trek-style shields proposed for space missions and the underwater survival quest of a marine biologist...

Scientists believe they now know which chemical in plants signals to them to start flowering – something that could have great commercial significance.

‘This could be a really important breakthrough in plant science,’ Imperial College London researcher Colin Turnbull commented in the Daily Telegraph. ‘Since the 1930s when it first became clear that something was communicating the perception of changes in day length in leaves to the shoot apex, and causing flowering, scientists have been trying to work out exactly how this mechanism works.’

While other studies have hinted at the role of a protein called Flowering Locus T Protein (FT protein), scientists from Imperial College London and the Max Planck Institute in Germany have now tracked its movement from leaves – where it is produced, to the shoot tip. They were able to do this in living tissues by adding a green fluorescent protein tag to the FT protein and using highly sensitive microscopes to monitor its journey.

The production of FT protein is triggered by a gene called CONSTANS, that reacts to changes in day length. The study has been published in the journal Science, along with another showing that a similar mechanism works in rice.

Also this week, UK gardeners were told that they could help halt the decline in bumblebee numbers by planting cottage garden style types of plants rather than traditional bedding plants. There are 25 different species of bumblebee, six or so of which are common in gardens. However, three species of the insect are now extinct in Britain and another nine are endangered.

The Bumblebee Conservation Trust is calling on the public to help researchers determine the distribution of bumblebees by taking part in a national survey, reported BBC News.

There was news for chocoholics and those of us who have been chomping our way through Easter eggs recently: according to a new study, eating chocolate makes the heart pound more than a passionate kiss. The heart rate and brain activity of 12 volunteers in couples were monitored while they kissed or ate a piece of dark chocolate. A bigger, longer response was observed in response to the chocolate melting in the mouth than when the partners kissed, reported the Daily Telegraph.

Dr David Lewis, who led the study, said, ‘While we fully expected chocolate - especially dark chocolate - to increase heart rates due to the fact it contains some highly stimulating substances, both the length of this increase together with the powerful effects it had on the mind were something none of us had anticipated.’

Dr Lewis works for private company, The Mind Lab, which is part-funded by the food industry, added the Guardian.

The discovery that a protein naturally found in human blood can block infection by HIV has raised hopes that it could lead to the development of a new class of drugs.

More than a million blood proteins were assessed by scientists for an inhibitory effect on HIV. They found that a molecule they have named virus-inhibitory peptide (VIRIP) was effective at blocking HIV, as was a synthetic version – which proved another factor wasn’t responsible for the effect. The peptide works by targeting a sugar molecule used by the virus to infect the host cell.

There are worries that, as HIV modifies its structure, it will become increasingly resistant to the drugs that are currently used. However, VIRIP could provide a new line of attack since it works in a different way to existing antiretroviral therapies.

‘Many people with HIV become resistant to current treatments over time so it is vital we keep working on expanding people's options,’ Roger Pebody, of the Terrence Higgins Trust told BBC News. ‘It may take years, but let's hope that this leads to an effective future treatment for HIV.’

A ‘caterpillar robot’ that crawls across the surface of the heart may one day enable doctors to perform precision heart operations under local anaesthetic and without opening up the patient’s chest, the Guardian reported. The two centimetre-long device known as HeartLander can be joystick-controlled by a surgeon.

While a clinical-ready prototype is a long way off, HeartLander has been successfully tested on the heart of a living pig. It was used to attach a pacemaker and deliver an injection. The heart’s rhythm was not affected by having the robot stuck to it and the doctors were also able to show that the device could manoeuvre its way around to the back of the organ – an area which is typically difficult for surgeons to reach.

Meanwhile, international health experts warned that we are at risk of a global epidemic of cardiovascular disease because people are failing to make appropriate lifestyle changes and take prescribed medicine for high blood pressure.

According to a report unveiled at the European Parliament, 7.1 million people are dying each year due to hypertention. Experts predict that by 2025 almost two thirds of adults worldwide could have the condition. Already affecting more than a third of British adults, it is also becoming an increasing problem in countries such as China, India and Russia, reported the Daily Telegraph. The main lifestyle factors blamed are smoking, obesity, excessive alcohol consumption, and high-salt and high-fat diets.

The first long-term study into the impact of salt consumption on health was also published this week. It confirmed that eating less salt reduces the risk of suffering a heart attack or stroke – by 25 per cent, reported the Times.

In related news, another study published in the journal Hypertension suggests that high blood pressure may be caused by inflammation in the brain.

Scientists from Bristol University conducted studies that showed a protein known as JAM-1 is linked to raised blood pressure in rats. The exact underlying mechanism is unclear, but the protein appears to trap white blood cells in the brain. The resulting restricted blood flow leads to poor oxygen supply and the researchers believe this goes on to trigger increases in blood pressure.

‘We are looking at the possibility of treating those patients that fail to respond to conventional therapy for hypertension with drugs that reduce blood vessel inflammation and increase blood flow within the brain,’ researcher Professor Julia Paton told BBC News.

The Daily Telegraph carried the news that the largest examination of hormone replacement therapy (HRT) and cancer – the Million Women Study – has revealed 1,000 women may have died from ovarian cancer since 1991 because they used HRT.

Researchers at Oxford University found that women taking HRT are at greater risk of both developing and dying from the disease – with one addition ovarian cancer case likely among 2,500 women receiving the treatment in a five-year period. However, they also said this risk returned to a normal level within a few years of stopping the treatment.

The chairman of Women’s Health Concern, which provides advice about the menopause, accused the study of ‘replacing science with sensationalism’.

The Royal Astronomical Society’s meeting took place in Preston this week. At the event, scientists at the Rutherford-Appleton Laboratory in Oxfordshire revealed proposals to develop Star Trek-style shields for spacecraft, to protect astronauts from cosmic rays and solar flares.

On Earth, the planet’s magnetic field deflects most of the deadly radiation originating in space. However, it remains a major hazard for astronauts who travel outside of this protective cocoon and a big obstacle to long missions, such as to Mars.

Artificially generated magnetic fields already protect the walls of experimental fusion reactors from superheated plasma. Now, a team led by Dr Ruth Bamford has been awarded 30,000 pounds to use this technology to protect a model spacecraft from harmful plasma – in this case keeping the plasma out, rather than in.

Dr Bamford told the Times: ‘It’s no accident that Star Trek featured this sort of technology, as it had advisors who work for NASA and it’s feasible. The shields seem to be some sort of invisible barrier, which energy bounces off, and that sort of deflector shield is exactly what we’re talking about.’

Another technology discussed at the meeting was that of ‘smart dust’. UK engineers envisage that tiny devices consisting of a computer chip within a plastic sheath that can be steered by voltage-induced shape changes could be used in space probes to explore other planets. Upon their release into planetary atmospheres, they would be carried on the wind. Wireless networking would enable them to fly in formation and share data.

The sensors needed for planetary exploration are currently too large to be carried on smart dust particles but scientists are hopeful that the pace of miniaturisation will mean suitably sized sensors become available within decades. In the meantime, they are working on the components and simulations, reported BBC News.

In other news this week, scientists from Oxford Brookes University warned that catalytic converters, which are fitted on cars to reduce emissions of harmful gases, are contributing to increased atmospheric levels of other toxic gases.

Former BA Media Fellow Hannah Devlin reported in the Times that, while catalytic converters have successfully reduced the amount of carbon monoxide and nitrogen oxide released by car exhausts, they have also changed the form in which sulphur escapes. The hydrogen sulphide and carbon disulphide now generated from petrol are both dangerous to human health at high doses. In Elephant and Castle in South London, hydrogen sulphide has recently been recorded at up to 7,000 parts-per-trillion. That’s compared to a typical reading in the 1500s of 70-100 parts-per-trillion.

BBC News also reported that using bioethanol as a fuel may have a worse impact on human health than conventional petrol. US scientists who used computer models to simulate air quality in 2020 are warning that ozone levels would increase if all cars were run on ethanol – and this would result in increased deaths from respiratory problems and asthma attacks.

The EU has agreed that ten per cent of transport must run on biofuel by 2020. Marc Jacobson, the atmospheric scientist who ran the simulations, argues that we should be instead looking to convert all vehicles to battery-electric, where the electricity is generated by wind power. This would eliminate 10,000 air pollution deaths annually and 98 per cent of vehicle carbon emissions, he said.

Meanwhile, Professor Bill McKelvey, a leading advisor to industry and the government has warned that the growing demand for biofuels will put pressure on world food supplies. He said Britain could face food shortages in the next 25 to 50 years.

’Making use of biofuels is not a mistake; it’s the correct way to go in terms of reducing our fossil fuel usage and reducing our carbon footprint over all,’ he told the Daily Telegraph. ‘But we have to remember the competitive situation between the use of grain for food production and biofuel production.’

Professor McKelvey believes we need more intensive farming to avoid such world food shortages and that GM crops could help us achieve this while avoiding the health risks of chemical treatments.

‘I would prefer to eat a genetically modified plant than one that had been treated with a pesticide,’ he added.

This was also the week that the United Nations Security held its first ever debate on climate change, amid some controversy.
(BBC News)

And a new initiative called the UK national stem cell network was launched to promote stem cell science amid warnings that the country risks losing its position at the forefront of research if the government fails to boost funding.
(The Guardian)

And finally...

It may sound like a David Blaine stunt but this was done in the name of science: marine biologist Lloyd Godson spent almost two weeks living in a capsule at the bottom of a lake to see whether Man could survive naturally underwater.

Algae watered with his own urine converted carbon dioxide into oxygen for him to breathe. He produced electricity by pedalling a bike hooked up to a generator and vapour condensed from air provided his drinking water. However, his diet of dried algae was supplemented by food delivered by divers, as there were fears he would be overcome by indigestion otherwise.

’It’s the first time this has been done,’ Mr Godson told the Times, ‘So it’s paving the way for future experiments in this area such as plant-based life support systems for underwater or space applications.

He coped with the task surprisingly well, and has now been invited by NASA to participate in an underwater habitat project in 2009.

He was relieved when his experiment finished though, commenting: ‘I will be glad to get out in the sunshine and fresh air again. I have had thoughts of running like Forrest Gump and not stopping.’