Volume 440 Issue 7083, 23 March 2006

Large dams benefit contractors and corrupt governments more than they aid the African people.

The production of dyes in the nineteenth century marked a turning point in the appliance of science.

Observers call for rules to be tightened.

Indian newspaper clippings request special parts.

Issue of ‘no consent’ raises fundamental questions.

Efforts to selectively break carbon-hydrogen bonds continue apace.

A wave of Chinese-built dams in Africa, particularly the Merowe project in Sudan, could have devastating consequences for local communities. Jim Giles reports.

Deeper analysis of probe data released.

Despite some remaining hurdles, the mind-bending and frankly weird world of quantum computers is surprisingly close. Philip Ball finds out how these unusual machines will earn their keep.

Tiny computers that constantly monitor ecosystems, buildings and even human bodies could turn science on its head. Declan Butler investigates.

US regulators are moving sharply to ease the early stages of drug development, despite safety concerns. Meredith Wadman reports.

Scientists are turning to automated processes and technologies in a bid to cope with ever higher volumes of data. But automation offers so much more to the future of science than just data handling, says Stephen H. Muggleton.

What will emerge from using the Internet as a research tool? The answer, Vernor Vinge argues, will be limited only by our imaginations.

The amount of scientific data is doubling every year. Alexander Szalay and Jim Gray analyse how scientific methods are evolving from paper notebooks to huge online databases.

The road leading from computer formalisms to explaining biological function will be difficult, but Roger Brent and Jehoshua Bruck suggest three hopeful paths that could take us closer to this goal.

To view the relationship between computing and science as a one-way street is mostly untrue today, argues Ian Foster, and will be even less true by 2020.

What if the current exponential increase in information-processing power could continue unabated?

Not everything is as it seems in the ceramics of Pauline Wiertz.

In any manufacturing process, quality control is crucial, and gene expression is no exception. A new pathway monitors mRNAs — the intermediaries of gene expression — and destroys faulty molecules.

Researchers persist in tackling our ignorance of what life was like way back in Earth's history. Evidence of methane production in ancient microbial ecosystems now emerges from 3.5-billion-year-old rocks.

The first glimpse into the molecular basis of how sodium ions are transported across cell membranes by ion channels shows that cation-selective channels are variations on potassium channels.

From time to time, over millennia, northwestern North America has experienced huge earthquakes. These events may be preceded by tell-tale subsidence, but the evidence is devilishly difficult to decipher.

If photonic circuits are ever to compete with their electronic counterparts, strong confinement of light waves coupled with low propagation losses is needed. A new class of waveguides offers both.

How can one find the minimum total energy of an infinite number of particles? A proof showing that, for certain interactions, periodic ‘ground states’ exist provides a new perspective on this, one of the oldest questions in physics.

Avian and human flu viruses seem to target different regions of a patient's respiratory tract.

Data from the Southern Ocean sea-ice extent, the biological productivity of the ocean, and atmospheric iron flux over the past eight glacial cycles indicate that during glacial terminations, changes in Patagonia apparently preceded Antarctic sea-ice reduction — showing that multiple mechanisms may be responsible for different phases of CO₂ increase during glacial terminations.

Four recent observational results that have challenged our understanding of high-redshift galaxies are resolved simultaneously if it is taken that 10-30 per cent of the stars in many galaxies at z ≍ 3-4 are mainly primordial — unenriched by elements heavier than helium.

Multi-epoch spectropolarimetry of a supernova reveals the abrupt appearance of significant polarization when the inner core is first exposed in the thinning ejecta — roughly 90 days after explosion.

The practical potential of channel plasmon polaritons (CPPs) is demonstrated by producing photonic components that operate at telecommunication wavelengths and can bend and split the CPP radiation — enabling the realization of ultracompact plasmonic components and paving the way for a new class of integrated optical circuits.

Crushing extraction and carbon isotope analysis of methane-bearing fluid inclusions in ˜3.5-Gyr-old hydrothermal precipitates from Australia has revealed that they contain microbial methane — providing the oldest evidence of methanogenesis and pre-dating previous geochemical evidence by about 700 million years.

Analysis of phenetic and/or crossing relationships in over 400 genera of plants and animals shows that although discrete phenotypic clusters exist in most genera (more than 80%), the correspondence of taxonomic species to these clusters is poor (less than 60%) and no different between plants and animals. However, crossability data indicate that 70% of taxonomic species and 75% of phenotypic clusters in plants correspond to reproductively independent lineages.

Pin1 converts proteins into cis or trans conformations — the amyloid precursor protein (APP) being one of Pin1's targets. This encounter limits the processing of APP into amyloid-β , the peptide that builds up in the brains of Alzheimer's patients. The results also suggest that APP in its cis conformation supports amyloidogenic APP processing, whereas the trans conformation does not.

Time-lapse imaging is used to follow the activity of several promoters that regulate competence genes in Bacillus subtilis, and the data used to develop a mathematical model of the gene circuitry — revealing that excitable dynamics underlies the positive and negative feedback loops that regulate entry into, and exit from, competence in an individual cell.

CHIP — a co-chaperone/ubiquitin ligase — not only targets chaperone substrates for degradation, but mediates Hsp70 turnover after misfolded substrates have been depleted. The sequential catalysis of the CHIP-associated chaperone adaptor and its bound substrate provides a mechanism for maintaining homeostasis by tuning chaperone levels appropriately to reflect the status of protein folding within the cytoplasm.

This study identifies a third eukaryotic quality-control mechanism that ensures only functional mRNAs are translated — 'no-go decay'. This system recognizes and degrades mRNAs with stalled translation elongation complexes, which might occur if the mRNA is damaged.

The Dam1 ring complex is a molecular device that can translate the force generated by microtubule depolymerization into movement along the lattice to facilitate chromosome segregation.

The structure of a sodium- and potassium-conducting pore is detailed, with the mechanisms revealed likely to be similar to those of cyclic nucleotide-gated channels that are fundamental to important physiological processes such as vision and olfaction.

Michigan, Minnesota and Wisconsin have had mixed fortunes in their efforts to build up their research infrastructure. Partnerships may prove to be the strongest construction, says Paul Smaglik.

Washington 2.0

Gas bubbles in rocks offer evidence for life on Earth 3.5 billion years ago.

Ion channels are essential for cellular existence, and mutations and other disruptions have serious, sometimes life-threatening consequences. Until recently, the way these channels operated was something of a mystery. But now high-resolution structural studies are revealing the secrets of these membrane proteins. Although treatments for diseases caused by faulty channels are a long way off, according to this NatureInsight, we are heading in the right direction.