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In brief – Research news and discovery “SO, WHERE is everybody?” Nobel laureate Enrico Fermi reportedly quipped to fellow physicists in 1950, when discussing why we haven’t seen any signs of alien civilisations if, as many believe, our galaxy is teeming with life. Now, a maths model may have an answer to Fermi’s paradox. Rasmus Bjørk of the Niels Bohr Institute in Copenhagen, Denmark, has calculated that 0.4 per cent of the stars (www. arxiv.org/astro-ph/0701238v1). So, Bjørk’s answer to the Fermi paradox: aliens haven’t contacted us because they haven’t had the time to find us yet. He adds that the search could be optimised by visiting only those stars that harbour habitable planets, which could be identified by planet-finding missions such as NASA’s Terrestrial Planet Finder. Bjørk is also “cautiously optimistic” about listening out for aliens with radio telescopes. eight probes – travelling at a tenth of the speed of light and each capable of launching up to eight sub-probes – would take about 100,000 years to explore a region of space containing 40,000 stars. When Bjørk scaled up the search to include 260,000 such systems in our galaxy’s habitable zone, the probes took almost 10 billion years – three-quarters the age of the universe – to explore just Aliens need a lot more time to find us THE gradual erosion of telomeres, the DNA caps at the ends of chromosomes, may signal an increased risk of heart disease. In a study of about 1500 men, those with shorter telomeres in their white blood cells turned out to be more susceptible to heart attacks than those with longer telomeres. The cholesterol-busting drugs called statins seemed to weaken the link, but only in people with comparatively short telomeres. “Without statins they might have been even shorter,” says Nilesh Samani of the University of Leicester, UK, who led the research (The Lancet, vol 369, p 107). The link could arise because degraded telomeres in blood cells that normally help repair damaged arterial walls might be making these cells less effective. It might one day give doctors a test to identify people at greatest risk, enabling them to get treatment early. Age takes its toll… ANOTHER risk factor for heart disease (see story above) is obesity, but if your heart is already failing, being fat could save your life. Gregg Fonarow of the University of California, Los Angeles, and his colleagues looked at the records of more than 100,000 patients hospitalised because their heart failure was worsening. They found that the fatter the person, the less likely they were to die during a week-long hospital stay (American Heart Journal, vol 153, p 74). Fonarow suggests that fat people may cope better with heart failure because they have more metabolic reserves to draw on when the heart isn’t pumping blood fast enough to meet the body’s needs. …but it’s not so bad to be fat Test for infection could spare babies from hidden danger A SIMPLE test could identify inflammation caused by infection in the wombs of mothers showing signs of premature labour, potentially allowing doctors to intervene and prolong their pregnancy. Routine tests can easily miss infections in the womb, which are one cause of premature births. Such babies often have learning difficulties or, in rare cases, severe brain damage. Catalin Buhimschi of Yale University School of Medicine and his team looked for proteins characteristic of inflammation in samples of amniotic fluid taken from 169 women admitted to hospital because they had gone into early labour or because their waters had broken prematurely. The samples were taken by amniocentesis, in which a long hollow needle is inserted through the abdominal wall and into the womb. The presence of infection could be confirmed within 15 minutes of testing, and the test picked up even low levels of infection (PLoS Medicine, DOI: 10.137/journal. pmed.0040018). The technique would primarily be used on women going into labour at between 20 and 34 weeks of pregnancy, where the risk to the child of an undiagnosed infection is much greater than the risk of miscarriage due to amniocentesis. Doctors might then be able to treat the infection using antibiotics, steroids or anti-inflammatory drugs in the hope of maintaining the pregnancy. MICHAEL ZUSTEIN/OEIL PUBLIC www.newscientist.com 20 January 2007 | NewScientist | 15
