Articles in 1998

munich

International space collaboration is being threatened by the shift to 'smaller, faster, cheaper' space missions, according to a transatlantic panel of space scientists.

Cell movement is mediated by dynamic networks of actin — monomers of actin polymerize into filaments near the plasma membrane. How are these actin structures organized? Two groups have found that a seven-protein complex, containing the actin-related proteins Arp2 and Arp3, is responsible for initiating and organizing an actin-based dynamic meshwork that forms protrusions at the leading edge of motile cells.

The first brain waves to be observed were measured at a frequency of ten cycles per second — that is, 10 Hz. Since then, waves have been detected at frequencies of 5, 40 and 200 Hz. But what do they do? One group has found that the 40-Hz waves are involved in a feedback-inhibition mechanism for coding 'events' (such as memories) in the brain. Another group has studied the 200-Hz waves, and they conclude that synchronization of neuron firing, which causes these waves, is due to gap junctions between nearby axons.

Natural history museums face an unprecedented opportunity as central players in biodiversity research. They and their financial supporters need to match fine words with appropriate actions.

washington

Public interest in science and technology is at an all time high in the United States, according to a study performed for the National Science Foundation.

beijing and shanghai

China is launching several major initiatives in human genomics, with budgets totalling over US$30 million over the next three years — and signs of even more investment to come.

Galaxy clusters must trap large quantities of dark matter, and we expect it to be sharply concentrated near their centres. But using a new method for interpreting the effects of gravitational lensing, a much smoother and less centrally concentrated distribution of dark matter is inferred in one cluster. This could produce insights into the mechanisms governing galaxy-cluster formation, or even be a clue to the nature of dark matter.

Mathematician and master of singular integrals

The choice of a new director for the International Medical Research Centre in Gabon is crucial for the future of an institution which has been criticized as lacking relevance and falling far short of its potential.

High-temperature superconductors need to be doped with elements that donate charge-carrier. By changing the dopant cation, the superconducting transition temperature can be changed markedly. Why? It is due to lattice strains, caused by disorder in the cation size. This solves a ten-year old puzzle — but leaves open the question of the microscopic mechanism of high-temperature superconductivity.

Dendritic spines are small, actin-rich structures that protrude from the sides of dendrites, and receive excitatory inputs to the brain. Using a clever piece of video imaging, one group has found that each spine seems like a tiny, writhing sack of actin filaments, struggling to escape. This movement depends on polymerization of the actin, and it may be involved in synaptic plasticity, contributing to the formation of so-called ‘perforated synapses’.

Natural history museums are shaking off their dusty image in a bid to show relevance to contemporary concerns. Central to a revival in their research fortunes is a unique contribution to our understanding of life's complexity.