Volume 392 Issue 6677, 16 April 1998

Enthusiasm for science is strong in Washington, but enthusiasm for necessary choices is not.

washington

US scientists would be foolish to expect Congress to double research spending over the next decade, according to one of the legislative body's most experienced science legislators.

paris

Three marine research agencies in Europe are planning to create a unified European fleet of research vessels with a common scientific programme.

moscow

Dozens of leading scientists have written to the Federal Security Service in support of two acoustics researchers who may be accused of betraying a state secret.

montreal

The University of Toronto is under pressure to resolve a battle with a seismologist of Chinese descent who has charged the university with racial discrimination in denying him a tenure-track professorship.

washington

NASA plans to double its budget for studying near-Earth objects this year.

washington

About 15,000 US science graduates, including 6,000 PhDs, have signed a petition that rejects the Kyoto agreement on global warming and argues that increases in carbon dioxide levels benefit Earth, according to the petition's organizers.

washington

The National Academy of Sciences has produced a glossy guide to advise teachers on how to teach education.

new delhi & london

The main United Nations fund for environmental research projects is to review its policy on supporting projects in developing countries.

london

A closure-threatened government food laboratory survived an earlier reorganization in order to protect its high quality research, according to an internal government document.

washington

A republican senator has introduced a bill that does not impose heavy restrictions on researchers and industry seeking access to identifiable patient information.

munich

The European Laboratory for Particle Physics (CERN) has begun thinking about the successor to its Large Hadron Collider, a $1.7 billion particle accelerator that will not be built for another eight years.

munich

Cooperation between scientists in different European Union states has increased significantly over the past decade, according to the European Commission.

washington

The United States should launch a 13-year, $440 million research programme to reduce scientific uncertainties surrounding the health effects of airborne particulate matter, according to the National Research Council.

tokyo

US government scientists are seeking consultations with scientists from Japan following Japanese claims that radish sprout seeds imported from the United States were to blame for last year's E. colifood poisoning outbreak.

A survey of spice use around the world concludes that spices serve the adaptive purpose of reducing food-borne disease. It highlights, however, the need for further researchin victu — in food itself — rather than in vitro.

Life on land stemmed from life in the sea, but many creatures have since taken the reverse route. A big problem to be overcome was that the body fluids of terrestrial animals are much less salty than sea water. Water can be replaced by drinking sea water, but the excess salt has to be excreted. A newly described fossil turtle not only extends the fossil record of marine turtles back to 110 million years ago, but displays evidence that it had massive salt-excreting lachrymal glands that were its passport back to the sea.

At a depth of around 410 km in the Earth's mantle, the speed of seismic waves rises sharply. The reason is thought to be the high-pressure transformation of the mineral olivine to wadsleyite at that depth. Seismological data have however been at odds with laboratory work with these minerals, in which their behaviour is extrapolated to mantle conditions. A study showing that manganese and iron can be exchanged between olivine and other mantle minerals is a step towards resolving these discrepancies.

One of the main concerns about genetically modified crops is the risk of contaminating ‘natural’ populations with the introduced genes. A technical development that reduces this risk is now reported, and the principle is simple — rather than introducing transgenes into the nuclear genome, from which they can be spread in the form of pollen, the genes are introduced into the chloroplast DNA. Chloroplasts are maternally inherited, so wild relatives of transgenic plants cannot be contaminated.

The mathematics of linear partial differential equations is well developed, but, increasingly, physicists deal with phenomena described by nonlinear equations. Mathematicians are striving to keep up. An old conjecture about the mathematics of phase changes has now been proved, providing a firm basis for calculating what happens at the boundary between water and ice, for example. Curiously, the behaviour of these transition regions must be the same in spaces with two, three, four, five or six dimensions, but could be completely different in seven or more.

Genetic control of development rests with the so-called homeotic (Hox) genes, mutations in which often result in spectacular phenotypes. For example,Antennapedia (Antp) mutant fruit flies develop legs where the antennae should be. But a new study shows that, contrary to previous thinking, Antp does not specify leg development — indeed, it is not even required to make a leg. Instead, Antp prevents the functioning of the homothoraxgene, a Hox gene that is responsible for antenna development.

Noise is usually just a hindrance to signal detection. But advances in measurement techniques mean that noise can now be used to probe electron kinetics. In systems such the fractional quantum Hall effect, many body interactions create carriers with effective charges less than that of an electron, reducing noise. In contrast, a system can be constructed with electrons sandwiched between two barriers, which increases noise by a positive feedback mechanism.

The useful properties of high-temperature superconductors are impaired by magnetic flux lines, or vortices, which dissipate energy and so cause resistance — unless pinned in place. Video films of the vortices show that they move like particles in liquids that are subject to Brownian motion, staggering from one pinning site (a defect in the lattice) to another. This insight has allowed ready-made data analysis techniques to map the so-called ‘pinscape’ and could eventually help in exploiting natural pinning to improve the performance of superconducting devices.

For all that bees, wasps and ants have tiny brains, many species have impressive navigational skills, which are largely vision-based. Experiments with one species of ant now furnish support for the idea that these ants navigate to their goal, say a food source, by using a sequence of ‘snapshots’ of the environment acquired when they were on their way home after first visiting that goal. On their way back, the ants frequently turn round and make short ‘inspection runs’ towards the goal, and it is proposed that the purpose is to take the navigational snapshots that enable them to find their way back again.

How can you tell when a plant is extinct? Although it may disappear for a time, there's always the possibility that it may emerge from a dormant state. This is just what has happened to the Killarney fern (Trichomanes speciosum), which has now been re-discovered in regions of England and Europe where it had been thought to be extinct. Rather than surviving in the form of delicate bottle-green fronds, however, the plant now exists in the gametophyte form — a free-living, independent life stage that looks more like a green fuzz on wet rocks.

Daedalus's ground-effect ramjet, or gramjet, was invented to fly low over a flat track, compressing the air in front of it, heating it underneath with burners, and gaining thrust from exhaust gases expanding against the upward-sloping rear surface. He now wants to run them over water, to clean up oil slicks: the gramjet would burn some of the oil and oxidize some of the rest, and the detergents thus created would disperse the remaining oil to leave a perfectly clean wake. A thick enough slick might even provide enough fuel for the gramjet to run for free.

Some readers were bemused, and others amused, to find a series of images by Cornelia Parker in the pages of Nature last autumn. Her work invites us to let our imaginations run free.

Featured in this section are analytical instruments and accessories, such as an ICP-HEX-MS and software for searching spectral libraries, and systems for scanning electron microscopy. compiled by Brendan Horton from information provided by the manufacturers.c b B H f i p b t