Articles in 2009

Is matching wing beats the key to maintaining genetic diversity in malarial mosquitoes?

Pinpointing nerve-insulating cells as the origin of devil facial cancer could aid diagnosis and vaccination.

It could take less of the greenhouse gas to reach a particular level of warming.

Heat wave in Baltimore made worse by hot air from Washington DC.

Deep-field image from Hubble triggers competing reports.

Nature looks back on a selection of last year's news stories to find out what happened next.

'Blue straggler' stars lie on or near the main sequence of star clusters and are sufficiently massive that they should have evolved into white dwarfs long ago. Statistical evidence indicates that in globular star clusters the blue stragglers probably form from binary stars. Here, 76 per cent of the blue stragglers in the open cluster NGC 188 are found to be currently in binary systems, a three times higher frequency than that among normal solar-type main-sequence stars.

A longstanding aim in molecular-scale electronics is to create a true transistor analogue in which charge transport through a molecule is directly controlled by external modulation of the molecular orbitals. The observation of such a solid-state molecular device is now reported. The data demonstrate that true molecular transistors can be created, and clear the way for molecularly engineered electronic devices.

Coastal ecosystems are sensitive to changes in the quantity and lability of terrigenous dissolved organic matter (DOM) delivered by rivers. The lability of DOM is thought to decrease with age, but this view stems from work in watersheds where terrestrial plant and soil sources dominate streamwater DOM. Here, glaciated watersheds on the Gulf of Alaska are shown to be a source of old but labile dissolved organic matter, suggesting that glacial runoff is an important source of labile reduced carbon to marine ecosystems.

As the climate changes, species will have to move if they are to remain in an area with the same average temperature. Here, this required movement — termed the velocity of temperature change — is quantified. The results indicate management strategies for minimizing biodiversity loss from climate change and suggest that montane landscapes may effectively shelter many species into the next century.

Non-small-cell lung cancers with activating mutations in the epidermal growth factor receptor (EGFR) often show a clinical response to EGFR kinase inhibitors but tend to develop drug-resistance mutations, including the gatekeeper T790M mutation. Here, a new class of EGFR inhibitors is developed; these agents are 30- to 100-fold more potent against EGFR with the T790M mutation, and up to 100-fold less potent against wild-type EGFR, than current EGFR inhibitors.

Although magnetic fields have an important role in the evolution of gas clouds in the Galaxy, the strength and orientation of the field in the interstellar medium near the heliosphere has been poorly constrained, with previous estimates varying widely and based on indirect observational inferences or modelling. Measurements of the deflection of the solar wind plasma flows in the heliosheath are now used to determine the magnetic field strength and orientation in the interstellar medium.

'Blue straggler' stars lie on or near the main sequence of star clusters and are sufficiently massive that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions and stellar mergers resulting from direct collisions between two stars. Here, two distinct parallel sequences of blue stragglers are reported in the globular cluster M 30, one arising from the evolution of close binaries, the other from direct collisions.

Non-volcanic tremor was discovered nearly a decade ago; however, a thorough explanation of the geologic process responsible for tremor generation has yet to be determined. A robust correlation is now identified between extremely small, tidally induced shear stress parallel to the San Andreas fault and non-volcanic tremor activity near Parkfield, California. Such tremor may represent shear failure on a critically stressed fault in the presence of near-lithostatic pore pressure.

The ATP-dependent chromatin assembly factor (ACF) generates and maintains nucleosome spacing by constantly moving a nucleosome towards the longer flanking DNA faster than the shorter flanking DNA. But how the enzyme moves back and forth between both sides of a nucleosome to accomplish bidirectional movement is unknown. Nucleosome movement is now shown to depend cooperatively on two ACF molecules, indicating that ACF functions as a dimer of ATPases.

There are now nearly 1,000 completed bacterial and archaeal genomes available, but as most of them were chosen for sequencing on the basis of their physiology, the data are limited by a highly biased phylogenetic distribution. To explore the value added by choosing microbial genomes for sequencing on the basis of their evolutionary relationships, the genomes of 56 species of Bacteria and Archaea selected to maximize phylogenetic coverage are now sequenced and analysed.

The ATP-dependent chromatin assembly factor (ACF) generates regularly spaced nucleosomes, but the mechanism by which ACF mobilizes nucleosomes remains poorly understood. Here, single-molecule FRET is used to monitor the remodelling of individual nucleosomes by ACF in real time; the study reveals previously unknown remodelling intermediates and dynamics, and indicates that ACF is a highly processive and bidirectional nucleosome translocase.

Multiple somatic rearrangements are often found in cancer genomes, but the underlying processes of rearrangement and the effects of this are unclear. A paired-end sequencing strategy is now used to map somatic rearrangements in human breast cancer genomes. More rearrangements in some breast cancers are found than previously recognized, including frequent tandem duplications that may reflect a specific defect in DNA maintenance.