Invasive species can disrupt natural and human-made ecosystems, throwing food webs out of balance and damaging the services they provide to people. Now scientists have begun to put a price tag on this damage. In a study published this week in Frontiers in Ecology and the Environment e-view, ecologists have listed the invasive species that cause the most harm to environment and cost the most money to control.

Scientists at the University of Liverpool have developed a new method to help researchers identify genes that can help protect the body during the ageing process.

The fossil record usually shows what adult animals looked like. But the appearance and lifestyle of juvenile animals often differ dramatically from those of the adults. A classic example is provided by frogs and salamanders. New discoveries from Uppsala, Cambridge and Duke Universities, published in Science, show that some of the earliest backboned land animals also underwent such changes of lifestyle as they grew up.

Transcatheter valve implantation is a newly developed technique for the curative treatment of high-grade aortic stenosis. It is likely to be of benefit especially to elderly, multimorbid patients for whom the risk of open heart surgery would be too great. The initial results obtained with this technique at the German Heart Center in Munich are presented in the current issue of Deutsches Ärzteblatt International by Sabine Bleiziffer and her colleagues (Dtsch Arztebl Int 2009; 106(14): 235-41).

Scientists at the Cambridge University have discovered that freshwater algae can form stable groupings in which they dance around each other, miraculously held together only by the fluid flows they create. Their research was published today in the journal Physical Review Letters.