Volume 466 Issue 7308, 12 August 2010

Republican criticism of stimulus-funded science projects is ill-informed and wide of the mark.

The week in science.

Researchers see major uncertainties in Deepwater Horizon spill assessment.

Faculty members launch attack on president of Karolinska Institute.

Geological storage of long-lived radioactive material is moving closer to reality in Europe, says Declan Butler.

Study shows that stripping mountains for coal has a much greater impact than urban growth.

Teragrid machine prepares to crunch ornithologists' data.

Having taken on the biggest job in biomedicine — leading the US National Institutes of Health — Francis Collins must now help his agency over a funding cliff. Meredith Wadman looks at his record so far, and his plans to cushion the fall.

Every summer for the past nine years, water with lethally low concentrations of oxygen has appeared off the Oregon coast. The hypoxia may be a sign of things to come elsewhere, finds Virginia Gewin.

Although largely unregulated, genetic tests are increasingly used to diagnose conditions, map ancestry or predict disease risk. In this, the first of two related pieces, Arthur L. Beaudet advocates the US Food and Drug Administration banning direct-to-consumer medical tests but leaving the analysis of clinical diagnostics to specialists. In the second, Gail Javitt argues that the agency should implement a regulatory framework for all health-related tests.

Although largely unregulated, genetic tests are increasingly used to diagnose conditions, map ancestry or predict disease risk. In this, the second of two related pieces, Gail Javitt argues that the US Food and Drug Administration should implement a regulatory framework for all health-related tests. In the first, Arthur L. Beaudet advocates the agency banning direct-to-consumer medical tests but leaving the analysis of clinical diagnostics to specialists.

Leadership, Michael Bond learns from two new books, is not about getting people to do things, it is about getting them to want to do things — and it emerged on the African plains.

Approaches that abandon traditional speech categories offer promise for developing statistical descriptions that encapsulate how speech conveys information. Grandparents would be among the beneficiaries.

Geochemical evidence for the existence of the mother of all mantle-source reservoirs for volcanism has come to light. The new results have provocative implications for our understanding of Earth's interior.

Some genes exclusively express only their maternal or paternal copy. Studies of the brain extend the list of such imprinted genes by an order of magnitude, highlighting their spatial and temporal regulation.

An aggressive and unpredictable fungal pathogen is devastating larch plantations in Britain. Its remarkably broad host range, and the possibility of further geographical spread, give heightened cause for concern.

Measurements of X-ray diffraction on small patches of a copper oxide superconductor reveal that oxygen crystal defects form fractal structures that seem to promote high-temperature superconductivity.

Some people are naturally more anxious than others. A brain-imaging study in monkeys provides surprising insights into which brain regions are under the influence of genes in this phenomenon and which are not.

How far back in the human lineage does tool use extend? Fossil bones that bear evidence of butchery marks made by stone implements increase the known range of that behaviour to at least 3.2 million years ago.

The identity of the cells that form the haematopoietic stem cell (HSC) niche in bone marrow has been unclear. These authors identify nestin-expressing mesenchymal stem cells as niche-forming cells. These nestin-expressing cells show a close physical association with HSCs and express high levels of genes involved in HSC maintenance, and their depletion reduces bone marrow homing of haematopoietic progenitors.

MicroRNAs are known to affect the levels of both messenger RNA (mRNA) and protein. But as protein production is dependent on the presence of mRNA, it was not clear what the relative contributions of microRNA-mediated mRNA cleavage and translational repression were. These authors have parsed out the two mechanisms, and unexpectedly find that microRNAs function primarily by affecting mRNA levels rather than their translation. This suggests a reassessment of many previous conclusions is necessary.

The oxygen interstitials in the layers separating the superconducting CuO₂ planes undergo ordering phenomena in La₂CuO_4+y that enhance the transition temperature (T_c). It is also known that complex systems often have a scale-invariant structural organization, but hitherto none had been found in high-T_c materials. These authors report that the ordering of oxygen interstitials in the La₂O_2+y spacer layers of La₂CuO_4+y high-T_c superconductors is characterized by a fractal distribution up to a maximum limiting size of 400 µ.

Advances in nanomagnetics research have brought powerful applications in magnetic sensing technology, but so far no high-resolution magnetic-imaging tool is available to characterize complex, often buried, nanoscale structures. These authors have developed a scanning probe technique in which the intense, confined magnetic field of a micromagnetic probe tip is used to localize the ferromagnetic resonance mode immediately beneath the probe, and demonstrate that they can image magnetic features at a resolution of 200 nm.

Cloud simulation is one of the most challenging tasks in regional to global-scale modelling. In many cases, the physical mechanisms responsible for observed cloud dynamics are unknown, making it difficult to realistically simulate their structure and behaviour. These authors show that open cellular clouds — characterized by low albedo — can be created by precipitation-driven downdrafts and that the resulting cloud structure forms an oscillating, self-organizing cloud field.

High ³He/⁴He ratios in some basalts have been interpreted as evidence for ancient reservoirs preserved in the Earth’s mantle; however, such rocks have never been observed to host the primitive lead-isotopic compositions required for an early formation age. These authors show that Baffin Island and West Greenland lavas exhibit primitive lead-isotope ratios consistent with a mantle source age of 4.55–4.45 billion years, and that their source may be the most ancient accessible reservoir in the mantle.

The earliest direct evidence for stone tools is between 2.6 and 2.5 million years old and comes from Gona, Ethiopia. These authors report bones from Dikika, Ethiopia, dated to around 3.4 million years ago and marked with cuts indicative of the use of stone tools to remove flesh and extract bone marrow. This is the earliest known evidence of stone tool use, and might be attributed to the activities of Australopithecus afarensis.

Cooperation in evolutionary games can be stabilized through punishment of non-cooperators, at a cost to those who do the punishing. Punishment can take different forms, in particular peer-punishment, in which individuals punish free-riders after the event, and pool-punishment, in which a fund for sanctioning is set up beforehand. These authors show that pool-punishment is superior to peer-punishment in dealing with second-order free-riders, who cooperate in the main game but refuse to contribute to punishment.

Anxious temperament in both humans and monkeys is an important early predictor of psychopathology and is known to be heritable. These authors characterize the neural circuitry associated with this trait and the extent to which its function is heritable. A scan of related monkeys after exposure to mild stress showed that activation in both the amygdala and hippocampus was predictive of anxious temperament, but that heritability of activity in hippocampus was greater than that in amygdala.

These authors performed a large-scale study in which they identified 2,576 somatic mutations across 1,507 coding genes from 441 breast, lung, ovarian and prostate cancer types and subtypes. The study provides an overview of the mutational spectra across major human cancers, implies an expanded role for Gα subunits in multiple cancer types and identifies several potential therapeutic targets.

An electrical gradient is crucial for the normal functioning of the heart. These authors show that Wnt11 signals are required to set up this gradient in the developing zebrafish heart by regulating the L-type calcium channel.

XXXMicrotubules are nucleated in vivo by γ-tubulin complexes and comprise 13 protofilaments. How this precise geometry is controlled remains unclear. These authors report the cryo-electron microscopic structure of the universally conserved, core microtubule nucleating complex, _γ-tubulin small complex. The structure provides insight into how this complex establishes thirteen-fold tubulin symmetry.

Normally, expression of bacterial DNA damage repair genes is repressed by the binding of LexA protein to SOS ‘boxes’ in their operators. DNA damage activates the RecA protein, which promotes autocleavage of LexA such that its repression is relieved and repair proteins are expressed. These authors solve several structures of LexA dimer bound to SOS box DNA, and find that the orientation of the DNA-binding wings can account for the strict intersite spacing.

The repair enzyme (6–4) photolyase uses light energy to cleave the ultraviolet-induced bond between pyrimidine dimers. These authors use ultrafast spectroscopy to examine the detailed electron and proton movements during the catalytic photocycle. Histidine 364 is identified as the crucial residue involved in the rate-limiting step.

Georgia looks to capitalize on its public-health and bioscience strengths.

Jeffrey Koplan, vice-president for global health at Emory University and former director of the Centers for Disease Control and Prevention (CDC), both in Atlanta, discusses Georgia's life-sciences and public-health sectors.

Finding time to explore new research areas can be beneficial for science and scientists, says Peter Fiske.

An unexpected stay.