Volume 454 Issue 7206, 14 August 2008

PAMELA mission offers tantalizing hint of success.

Swedish researchers criticize credentials of convention.

With the world's love of cars showing little sign of abating, manufacturers are under increasing pressure to make vehicles less polluting and oil dependent. Duncan Graham-Rowe explores some of the technologies that could keep us on the road.

Biochemical method of tracking microbes hits the limelight.

For Marcel Proust, the madeleine evoked childhood memories — a new treatment of the science of smell attempts to take our everyday experience of odour to a more insightful level, explains Gary Beauchamp.

In today's computer age, the implications of the discovery in formal logic that Newman and Nagel articulated in 1958 are of even broader interest, says Andrew Hodges.

Pairs of quantum-mechanically entangled particles seem to know at once what is happening to each other. Experiments show that even if this signalling is not instantaneous, it must be really, really fast.

Certain enzymes that synthesize antibiotics play a game of pass the parcel, handing biosynthetic intermediates from one active site to another. A study reveals the dynamic nature of interactions between the enzyme domains.

The indications are that a solid ball of iron lies at Earth's centre. But only the identification of an elusive seismic signature can confirm the long-standing assumption that it is indeed solid.

Humans who colonized Australia did not reach Tasmania until thousands of years later — granting the island's giant kangaroos a brief respite before they joined their Australian brethren in oblivion.

A vacuum may be devoid of matter, but its shape is still important. The strength of the Casimir force caused by quantum fluctuations in the space between surfaces is critically dependent on their nanometre-scale shape.

A drug that normally suppresses an immune response by trapping lymphocytes in lymphoid organs results in the elimination of a chronic viral infection when applied at low doses. Why should this be?

Autism is a common neurodevelopmental syndrome with a strong genetic component. The study of autistic individuals whose parents are cousins highlights the genetic diversity of this condition.

A sleepy brain pays little attention to its surroundings, and its neurons are lulled by a common oscillation. As the brain swiftly rouses from this sluggish state, its neurons function more independently.

Ghrelin stimulates food uptake by bringing about changes in mitochondrial respiration and proliferation, which are essential for activation of NPY/AgRP neurons. The effects of ghrelin are dependent on the presence of UCP2.

A structure of the termination complex shows that release factors that recognize stop codons cause the peptide chain and mRNA to dissociate from the ribosome at the end of translation. A conserved motif in the release factor participates in hydrolysis of the final tRNA-peptide bond.

The compositions of the asteroids most likely to hit the Earth are expected to reflect that of the most common meteorites. Vernazza et al. report that most potentially hazardous and near-Earth asteroids have spectral properties similar to LL chondrites, a class of meteorites that is relatively rare.

Experiments have almost ruled out a classical explanation for entanglement, but it is possible that one event could influence a second if the influence occurs faster than the speed of light. The authors put experimental bounds on the speed of such hypothetical influences.

A step towards an improved method of fullerene production was the recently reported synthesis of a precursor and its subsequent dehydrogenation to C₆₀. Otero et al. show that when depositing precursors on a platinum surface and heating to 750 K, most precursors are transformed into the corresponding fullerenes.

A palaeoclimatic problem is explaining the transition from 41-kyr to 100-kyr climatic cycles. Bintanja and colleagues suggest that the gradual emergence of the 100-kyr cycles is due to the increased ability of the North American ice sheets to survive insolation maxima and reach continental size.

Seismologists have long striven to understand the Earth's inner core, but the required seismic-wave observations are experimentally very difficult. Now Wookey and Helffrich report two observations of an inner-core shear-wave phase ('PKJKP'), and derive constraints on inner-core properties.

Differences in synchronized activity in cortical neurons characterize different brain states. Petersen and colleagues now show that in mice the membrane potential of nearby neurons is highly correlated during quiet wakefulness but this correlation is reduced when mice are actively whisking. This suggests that internal brain states dynamically regulate cortical membrane potential synchrony during behaviour.

A mathematical model shows that favouring chance recruitment of a given signalling molecule to sites at the cell's membrane where it is already bound-a positive feedback-is sufficient to allow the spontaneous emergence of polarity, provided that the total pool of this molecule is small.

In this paper, a screening system based on the specific targeting of Drosophila genes with an RNAi library identifies host factors involved in influenza virus replication.

The immunosuppressive drug FTY720 is shown to prevent establishment ofa chronic lymphocytic choriomeningitis infection in mice and to cure established chronic infection. Clearance of the virus is associated with an augmented virus specific T cell response.

Active ribozymes are identified in the 3' UTRs of several rodent lectin genes. These have a split structure, such that both halves must self-cleave and reassemble to give activity, and could potentially regulate gene expression.

The structure of the apo thiolation-thioesterase di-domain fragment of the EntF non-ribosomal peptide synthetase subunit of enterobactin synthetase is solved. Extensive inter- and intra-domain motions are observed, and these are modulated by interactions with other proteins that participate in the biosynthesis of enterobactin.

The three-dimensional structure of a type II thioesterase, free and in complex with a thiolation domain, is determined. Comparison with type I thioesterases reveal the basis for substrate selectivity and the different modes of interaction of the two types of thioesterases with thiolation domains.

Getting to grips with scientific variables.

Neighbouring neuron recordings reflect behavioural changes.