theoretically...

Like an ice cube in your drink? Researchers in Indiana have made the smallest ones ever observed, consisting of just eight molecules of water. To their surprise, the molecules naturally arranged themselves into cubic structures, in two forms which differed in the arrangement of the hydrogen bonds (the weak inter-atomic forces) inside the cubes. The work, reported in Science, provides new information on water's unique ability to form hydrogen bonds with itself to form large networks. That's what gives water many of its unique properties - including the capacity of solid ice to float on liquid water, which helps aquatic organisms to survive winter. The experiment was conducted at rather lower temperatures: the equivalent of 1 degree above absolute zero.

Britain: it's a great place to develop genetically modified food. So says Martin Farrow, managing director of United Oilseeds, a large US company. At an agribusiness conference last week, he said that the UK has a large number of professional growers operating in a small geographic area. "Before long we shall see a new range of exciting crops coming on to UK farms," he said. But initially new crops will need to be grown, stored and processed separately. Farrow warned that this meant added costs for farmers and organisations such as United Oilseeds. "These will have to be met from the consumer," he said. No hint of whether he is keen for the consumer to be told by labelling about the identity of these crops once they're in food, though.

President Clinton has put forward a Bill which would ban anybody in the US, whether in the public or private sector, from producing children via the cloning techniques used to produce Dolly the sheep. It wouldn't stop animal research into the cloning of DNA in cells. The ban would last for five years from its enactment, when it would be reviewed. Meanwhile in the UK, the Human Fertilisation and Embryology Authority is still seeking legal advice on whether it has statutory powers to prevent human cloning by the nuclear transfer method.

If genetic mutations are rare and mostly bad for you, why do as many as 1 per cent of natural bacteria have high mutation rates? According to studies in France and the US, reported in Nature, having such mutation rates can be useful if you are adapting to a new environment - as bacteria often are. The theory suggests that "mutator" genes, which generate new alleles rapidly, can thus be positively selected and can produce favourable mutations which are able to adapt readily. The idea is backed up by experiments on E.coli at the University of Pennsylvania: they found that faster evolution is possible once high mutation rates have evolved. The implications are that we should expect the more pathogenic organisms (such as HIV) to have higher mutation rates - which they do.