Volume 390 Issue 6659, 4 December 1997

Exposure of preprints on servers does not preempt their submission to this journal.

kyoto & london

The United States has made a significant policy shift that could pave the way for an agreement on targets to reduce man-made greenhouse gas emissions that are causing global warming.

munich

The ‘internal market’ ministers of the member states of the European Union last week approved the latest draft of the European Commission's directive on the legal protection of biotechnological inventions, which allows the patenting of human genes as well as transgenic plants and animals.

munich

Germany's Max Planck Society, which runs 73 basic research institutes, has approved a new set of internal regulations to handle suspected cases of scientific misconduct.

london

Cheating remains widespread among students at US universities, according to the results of a survey of 4,000 students at 31 institutions.

washington

NASA hopes to begin scientific balloon flights of up to 100 days duration as a way of conducting near-space research at a fraction of current launch costs.

london

Britain's six research councils are to keep a close eye on the relative success of men and women applying for grants and fellowships.

london

Latin American governments have clashed with environmentalist groups over the application of the United Nations biodiversity convention to forestry policy.

montreal

A four-year inquiry into the infection of thousands of Canadians with HIV and hepatitis C through blood products has called for a new, and independent national blood agency.

paris

European life scientists seeking grants from the European Union's next five-year funding programme may need a stamp of ‘ethical approval’ for their proposals from the European Commission.

paris

The European Commission is to tighten a directive first issued in 1991 covering the deliberate release of genetically modified organisms into the environment.

moscow

The Russian president, Boris Yeltsin, has expressed concern that the continued exodus of scientists from Russia has become a threat to national security.

tokyo

Officials at a US naval air base in Atsugi, Japan, plan to install an infrared sensor to monitor gases from a nearby waste incinerator which they claim is discharging toxic pollutants.

london

More than a hundred members of Britain's Parliament have criticized the government for failing to develop a policy for managing plutonium removed from dismantled nuclear weapons.

canberra

Tension has been running high at the Australian National University in Canberra, where efforts to absorb a 14 per cent cut in government funding over four years have included a move to change the management of its renowned Institute of Advanced Studies.

The Chicxulub crater is the remnant of a meteorite impact that is blamed for killing off the dinosaurs. A new seismological survey shows that it is smaller than many scientists had thought, and extends deeper than anyone had suspected.

How can we make predictions about variability in the sizes of populations or the species composition of communities? Two new papers begin to solve these problems by dissecting them into smaller pieces — specifically, by looking at microbial microcosms. And they find that, in these systems, the predictability of communities may depend on species richness. In other words, the more ‘redundant’ species there are in the community, the more consistent is the function of the ecosystem.

Last month, two new moons were discovered orbiting Uranus. They differ from those already known, being much further from the planet, and having elongated orbits — these are ‘irregular’ moons, such as are seen around all the other giant planets, Jupiter, Saturn and Neptune. So the discovery makes Uranus more like the other planets, to the relief of some astrophysicists.

Whenever biomass is degraded, and oxygen runs out, the methanogenic bacteria appear and make profuse amounts of methane. The structure of the enzyme that produces it, methyl-coenzyme M reductase, has now been worked out. The structure of the nickel centre and its interaction with substrates reveal the mechanism of one of the few organometallic reactions in biochemistry. Because the methanogens belong to the Archaea, one of the ancient divisions of organisms, the new work also gives a glimpse into what may have been one of the earliest forms of metabolism.

Clues to our past climate can be found in marine sediments. The ratios of different oxygen and carbon isotopes within the buried shells of marine creatures depend on water temperature, among other things. But it now seems that they also depend on the total concentration of carbonate in sea water. For many periods, these palaeoclimatic codes will now have to be deciphered again — lowering our estimate of temperatures during the last ice age, for example.

A gravity anomaly, centred over Hudson Bay in Canada, has defied definitive explanation. Among the reasons for the anomaly could be that this area has not yet recovered (in a process known as post-glacial rebound) from being covered by a massive ice sheet during the last glacial maximum; or that it is one manifestation of unusual mantle convective flow in the Earth below. An innovative analysis of the global gravity field, which explores variation in the field's spectral content, provides the best answer yet — that 50% of the anomaly is due to incomplete post-glacial rebound. Moreover, the new approach will be widely applicable to other questions about Earth's structure.

The difference between men and women could be getting smaller, according to a paper that describes a function for female hormones (oestrogens) in the male reproductive tract. Mice that lack the gene for the a form of the oestrogen receptor are infertile, and this turns out to be due to a defect in the process by which sperm are prepared for storage in the testis. Usually, storage involves resorption of fluid from around the sperm, but, in the knockout mice, more fluid is secreted. So the effects of female hormones in males may actually be widespread.

Magnetic storms bring auroras to low latitudes and perturb the magnetic field all over the Earth, disturbing navigational systems and sometimes even electrical power grids. They are caused by sudden changes in the currents flowing close to the Earth, particularly the ‘ring current’ that flows intermittently within the Earth's magnetosphere. It was thought that the ring current was fed by smaller magnetic disturbances called substorms. But it seems that substorms are instead earthquake-like releases of magnetic stresses, allowing the ring current to be built up by the larger-scale interplanetary magnetic field.

A common consequence of large-scale oil spillage in coastal waters is the fouling of marine birds; a common response is to clean those birds that survive the initial incident, and release them back into the wild. Two papers, analysing British and Dutch data on the rehabitation of oiled guillemots, show, however, that such cleaning endeavours are largely doomed to failure — they respectively report that only about 1% and 20% of the birds survived their first year after release.

This week Daedalus wonders how to make an artificial solar eclipse, and concludes that it should be possible to do so by obscuring the Sun with a high-flying circular shutter. His ‘Eclipsat’ will orbit the Earth at a height of 1,000 km, producing a solar eclipse every 105 minutes along a track 5 km across and up to 8,000 km wide. It should also be able to generate an ‘anti-eclipse’, reflecting the Sun down onto a narrow track on the dark side of the Earth.

Josef Albers aimed to neutralize all elements bar one in his paintings, leaving colour as the only variable. The concept has strong parallels with scientific experiments to test theories.