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Podcast TranscriptThe Naked Scientists: Science Radio & Science Podcasts |
| 24th Mar 2002 | < Previous Show | Next Show > | |||||||||||
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Lake Vostok Analysis Simplified
Lake Vostok is the world's largest subglacial or literally 'beneath the ice' lake in thw world. It was discovered in 1996 when scientists were looking at radar images of the antarctic ice. The lake is 30 miles wide, 140 miles long and about 3000 feet deep. Scientists think that it has remained sealed off from the outside world for over 35 million years, meaning that no human has ever seen it. Researchers are excited about lake Vostok because the conditions within the lake which is maitained by heat rising from the earth's crust, might mimic those found on some of the more distant planets in our solar system, meaning that if life is found flourishing in Vostok, there may be life elsewhere in space. The problem is how to get into the lake without polluting it and spoiling its pristine waters forever. A russian team have drilled down to within 100 metres of the surface of the water, producing one of the worlds longest ice-cores, which spans over 400,000 years. Excitingly, analysis of the ice has revealed micro-organisms frozen into the ice, which must have come from the lake originally, suggesting that the lake may in fact be teeming with life. So, how to analyse the lake without polluting it...a team of glaciologists from Columbia University led by Robin Bell, have found that although the lake itself is millions of years old, the water in the lake changes fairly frequently by freezing onto the overlying ice sheet, and being replaced from elsewhere. Because the ice overlying the lake is moving - albeit slowly (at about 35 miles every 20,000 years !) - analysis of ice from further away is analogous to analysing the lake itself, they say.
Interview with glaciologist Cynan Ellis-Evans about subglacial lakes and the chances of finding life in Lake Vostok
24th Mar 2002
Good News for Sufferers of Tinnitus
Tinnitus sufferers are tortured by continuous buzzing or ringing noises in their ears, even when they are experiencing total silence, and the sounds cannot be blocked out. Most people experience the problem at some time in their lives, usually after prolonged exposure to loud machinery, or music, and in these instances the problem usually goes away by itself, once the source of loud noise is removed, over the ensuing hours or days. But for 5% of people the problem becomes chronic and debilitating. Researchers have recently begun to scan the brains of tinnitus sufferers and, surprisingly, have found that the part of the brain that responds to frequencies corresponding to the rogue sounds are disproportionally large compared with the area devoted to hearing other frequencies. A similar distorsion effect is seen in the part of the brain controlling the lost limbs in amputee patients. In this situation the area of the brain representing the lost limb seems to change allegiance so that it begins to respond to other, still intact, parts of the body instead. Many such patients report that they can still feel their lost limb, although the sensations they experience, which are often painful, are derived from other parts of the body, and this experience is described as 'phantom limb syndrome'. Experts at Heidelberg's Central Institute of Mental Health have speculated that tinnitus is the phantom limb pain of the auditory system and therefore might be amenable to the same drug treatment used for the control of phantom limb syndrome after amputation.
24th Mar 2002
How Pollution Harms your Health
It is fairly easy to understand why airborne pollution might be bad for your lungs and contribute to allergic conditions such as asthma, but it is more difficult to explain why, on days when pollution levels are very high, other illnesses, including fatal heart attacks, are much more common. To tackle this problem a group of researchers gave volunteers air to breathe containing tiny carbon particles, like those produced by engines. The carbon particles were labelled with a harmless radioactive substance which allowed the scientists to follow where the particles had gone after they were breathed in. They were surprised to find that the particles found their way into the bloodstream within as little as 1 minute of being breathed in, possibly explaining, they say, the link between pollution and illness affecting other parts of the body besides just the lungs. (Circulation 2002; 105:411-4)
24th Mar 2002
40% More Pregnancies Amongst Women Over 40
As more women are pursuing careers for longer, the birth rate in women over 40 had increased by over 40%, with 17,000 births in this age group from 1999 to 2000. The overall birth rate in England has been falling since 1990, but increasing in women over 30 years of age. Better contraceptive options, medical advances making it possible for women to have children later and the fact that it is more socially acceptable for older women to have a baby later have all led to this trend. The downside of having babies later is the reduction in your fertility as your eggs are older, and the increased risk of miscarriage in older women, perhaps partly attributable to the increased risk of chromosomal/other genetic problems.
24th Mar 2002
Polar Bears May Be Threatened By Global Warming
You will probably have heard that the ice-caps are melting at a higher rate than before. A large part of one of Antarctica's ice shelves has broken away recently. The Arctic ice-cap is also decreasing in size, which is threatening the polar bears numbers. There are currently about 25,000 polar bears in the Arctic. Polar bear cubs spend weeks in ice dens, as they are believe it or not smaller than a human baby at birth and are blind similar to other mammalian babies. Increased numbers of bears are dying when the ice and snow melts causing collapse of their dens. Every Summer the pack ice is decreasing in size, which is problematic, as polar bears live mainly on the pack ice, and are not adapted to living on the land itself. They swim in the sea/ice holes off the pack-ice to catch their main food which is ring seals. The break-up of the pack-ice means shipping lanes may be able to open between Siberia and the Arctic, good news for human trading but bad news for the polar bear.
24th Mar 2002
Pop Up Toilets for Improved Nightlife and Street-life !
If you have ever been to Amsterdam you may have noticed the old green metal urinal cubicles at intervals along the canals. A new type of urinal has just been tested which pops out of the ground at night-time when required. It is grey in colour and has 3 urinals around it. In tests in Holland it was very successful, and all the men approved. The women approved as well as the Police and local residents as the streets are kept cleaner. However the women wondered when a version for them would arrive? These super pop-up urinals are due to be tried in the UK later this year, in Reading first of all.
24th Mar 2002
Breast Screening for Cancer - Is it Effective ?
Screening women aged 50 to 69 for breast cancer does save lives, according to the World Health Organisation. However, there has been a big debate recently about whether mammography is worthwhile since Danish researchers question the validity of studies suggesting that it is effective. Now the internal Agency for Research on Cancer has reviewed the scientific evidence. They have concluded that screening reduces the death rate by 4 in 10,000. It is difficult though since some women screened can subsequently undergo treatment for disease which, whilst detectable on screening, would never have caused symptoms during her lifetime. Furthermore, the X-rays used to carry out a mammogram can themselves produce cancers in a tiny proportion of those exposed.
Article about the effectiveness of health screening.
24th Mar 2002
Ice Galore in Antarctica
It's all been happening in the Antarctic this week. First a huge iceberg 9 times the size of Singapore broke away into the sea. Then the Larsen B ice shelf, which had been floating on the sea for at least 2000 years, collapsed into thousands of icebergs. It must have been very dramatic, because within a month, an area of ice about the size of Cambridgeshire collapsed, creating 500 billion tonnes of icebergs. Neither of these events will make any difference to global sea levels. They could even be part of the natural cycle of events Antarctica. But there has been much speculation that the collapse of the ice shelf was prompted by global warming. The region of the Antarctic where it was located has experienced the most rapid warming of anywhere else on earth over the past 50 years.
24th Mar 2002
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