Volume 469 Issue 7329, 13 January 2011

Scientists in Romania and Bulgaria are having the best and the worst of times.

Simple tools to diagnose mental illness should not be offered without sound supporting evidence.

Scientific leaders have been too quick to praise the reprieve for research money, says Colin Macilwain. The slashing of teaching funds will do real damage.

The week in science.

University officials admit data withheld from review panel before misconduct charges arose.

Particle accelerator to be switched off this year, as lack of funds spells the end for US bid to capture Higgs particle.

Romanian researchers' prospects improve, whereas scientists in Bulgaria face a bleak future.

Kepler's latest discovery is step closer to a true Earth analogue.

Seed companies race to tap multibillion-dollar market.

Arctic and Antarctic scientists are urged to share data, ideas and infrastructure.

Researchers are scrambling to understand how best to deploy conservation zones.

Japanese hospitals are using near-infrared imaging to help diagnose psychiatric disorders. But critics are not sure the technique is ready for the clinic.

Climate change means that national parks of the future won't look like the parks of the past. So what should they look like?

On the anniversary of Haiti's devastating quake, Nicholas Ambraseys and Roger Bilham calculate that 83% of all deaths from building collapse in earthquakes over the past 30 years occurred in countries that are anomalously corrupt.

The dismal patchwork of fragmented research on disease-associated biomarkers should be replaced by a coordinated 'big science' approach, argues George Poste.

A collection of essays highlights the pressing challenges of managing global waters, finds Clive Schofield.

Owen Flanagan is unconvinced by Antonio Damasio's argument that 'the self' is needed to explain consciousness.

Josie Glausiusz enjoys a thought-provoking exhibition.

Studies of animal populations often use tags to track the fate of individuals and assume that there is no adverse impact. Work on penguins shows that seemingly innocuous flipper bands affect survival and breeding success. See Letter p.203

Generations of physicists have spent much of their lives using Richard Feynman's famous diagrams to calculate how particles interact. New mathematical tools are simplifying the results and suggesting improved underlying principles.

The functions of proteins are critically coupled to their interplay with water, but determining the dynamics of most water molecules at protein surfaces hasn't been possible. A new spectroscopic method promises to change that.

Stacking two oxide insulators together is known to yield a conducting system at the interface between the oxides. But the discovery that simply cleaving such an insulator yields the same outcome is unexpected. See Letter p.189

A survey of bumblebees in North America provides unequivocal evidence that four previously common and abundant species have undergone recent and widespread population collapse. Various explanations remain possible.

The Eastern Lau spreading centre in the Pacific Ocean is the subject of especial interest. The influence of the neighbouring subduction zone is considerable, but evidently has unexpected limits. See Letter p.198

Cellular compartmentalization is an effective way to build gene circuits capable of complex logic operations, in which binary inputs are converted into binary outputs according to user-defined rules. See Letters p.207 & p.212

G-protein-coupled receptors initiate a wide range of signalling pathways in cells. It seems that both a G protein and an agonist molecule must bind to the receptors to persistently activate them. See Article p.175 & Letters p.236 & p.241

The X-ray crystal structure of the human β₂ adrenergic receptor, a G-protein-coupled receptor, in an agonist-bound 'active' state is solved. Comparison of this structure with a previously published structure of the same GPCR in an inactive state indicates that minor changes in the binding pocket of the protein lead to major changes elsewhere — there is a large outward movement of the cytoplasmic end of one of the transmembrane segments and rearrangements of two other transmembrane segments. This structure provides insights into the process of agonist binding and activation.

The observed number counts of high-redshift galaxy candidates have been used to build up a statistical description of star-forming activity at redshift of about z>7. Here it is reported that gravitational lensing is likely to dominate the observed properties of galaxies with redshifts of about z>12, when the instrumental limiting magnitude is expected to be brighter than the characteristic magnitude of the galaxy sample. The number counts could be modified by an order of magnitude. Future surveys will need to be designed to account for a significant gravitational lensing bias in high-redshift galaxy samples.

This study measures 'puddles' of charge in a fractional quantum Hall device and finds new evidence for the existence of quarter charge particles, thereby boosting confidence in the prospects for topological quantum computation.

An exotic two-dimensional electron gas (2DEG) forms at oxide interfaces based on SrTiO₃, but the precise nature of the 2DEG has remained elusive. In a systematic study using angle-resolved photoemission spectroscopy (ARPES), new insights into the electronic structure of the 2DEG are obtained. The findings shed light on previous observations in SrTiO₃-based heterostructures and suggest that different forms of electron confinement at the surface of SrTiO₃ lead to essentially the same 2DEG.

Many biomineralized tissues (such as teeth and bone) are hybrid inorganic–organic materials whose properties are determined by their convoluted internal structures. Now, using a chiton tooth as an example, this study shows how the internal structural and chemical complexity of such biomaterials and their synthetic analogues can be elucidated using pulsed-laser atom-probe tomography.

This study shows that across-strike and along-strike changes in crustal properties at the Eastern Lau spreading centre are large and abrupt, implying correspondingly large discontinuities in the nature of the mantle supplying melt to the ridge axes. It is concluded that stable, broad triangular upwelling regions, as inferred for mid-ocean ridges, cannot form near the mantle wedge corner. Instead, the observations imply a dynamic process in which the ridge upwelling zone preferentially captures water-rich low-viscosity mantle when it is near the arc. As the ridge moves away from the arc, a tipping point is reached at which that material is rapidly released, resulting in rapid changes in the character of the crust formed at the ridge.

Much of what we know about the behaviour of animals in the wild comes from studies in which individual animals are marked for identification purposes. But can the marking itself affect the outcome? This study shows that it does. In a ten-year study on king penguins in the Antarctic, penguins sporting identification bands on their wings had significantly lower long-term fitness than unmarked penguins. This study should give pause for thought to researchers seeking to discover the behaviour of animals in the wild.

For synthetic biologists' creativity to be unleashed, basic circuits must become truly interchangeable, that is, modular and scalable. This study, one of two linked papers, has harnessed yeast pheromone communication to achieve complex computation through communication between individual cells performing simple logic functions. Such extracellular 'chemical wiring' is one promising way to get around intracellular noise when building more complex genetic circuitry.

For synthetic biologists' creativity to be unleashed, basic circuits must become truly interchangeable, that is, modular and scalable. This study, one of two linked papers, has harnessed bacterial 'quorum sensing' to achieve complex computation through communication between individual cells performing simple logic functions. Such extracellular 'chemical wiring' is one promising way to get around intracellular noise when building more complex genetic circuitry.

Here, single nucleotide variants within the LMO1 locus are shown to be associated with inherited susceptibility to neuroblastoma, a childhood cancer of the sympathetic nervous system. Acquired structural variation in the same locus was also frequently found in neuroblastoma patients, leading to the suggestion that loci identified through genome-wide association studies might be also prone to somatic alterations and therefore identify potential therapy targets and/or biomarkers of tumour aggressiveness.

Mitochondrial reactive oxygen species are shown to be required for activation of the NLRP3 inflammasome by various stimuli.

During mitosis, adherent cells change from a flattened to a rounded morphology, and this is thought to be necessary for the geometric requirements of cell division. Here, the forces that drive this shape change are studied. Mitotic rounding force depends both on the actomyosin cytoskeleton and the cell's ability to regulate osmolarity. The rounding force is generated by osmotic pressure and the actomyosin cortex maintains this rounding pressure against external forces. These results support the idea that in animal cells, the actomyosin cortex behaves like an internal cell wall that directs osmotic expansion to control cell shape.

The kinase JNK is known to stimulate c-Jun transcriptional activity, but the molecular mechanism has been unclear. Here, N-terminal phosphorylation of c-Jun is shown to antagonize the interaction of c-Jun with Mbd3, a component of the repressor complex NuRD. The interaction between c-Jun and Mbd3 is shown to be important in regulating the proliferation of intestinal progenitor cells in mice.

The X-ray crystal structure of the human β₂ adrenergic receptor, a G-protein-coupled receptor (GPCR), covalently bound to a small-molecule agonist is solved. Comparison of this structure with structures of this GPCR in an inactive state and in an antibody-stabilized active state reveals how binding events at both the extracellular and intracellular surfaces stabilize the active conformation of the receptor. Molecular dynamics simulations suggest that the agonist-bound active state spontaneously relaxes to an inactive-like state in the absence of a G protein.

Here, the X-ray crystal structure of the β₁ adrenergic receptor, a G-protein-coupled receptor, bound to four small molecules that either act as full agonists or partial agonists is solved. The structures show that agonist binding induces a contraction of the catecholamine-binding pocket relative to the antagonist-bound receptor. This work reveals the pharmacological differences between different ligand classes, which should facilitate the structure-based design of new drugs with predictable efficacies.

Antigen receptor loci contain numerous gene segments that are recombined in response to antigen stimulation. The RAG endonuclease makes the double-strand breaks that initiate recombination. The ends of these breaks are hairpins that can only be cleaved by the Artemis nuclease. Here, it is shown that the specificity for Artemis is dictated by the histone protein H2AX, in cooperation with the repair protein MDC-1. In the absence of H2AX, another nuclease, CtIP, can open the ends but they are not joined efficiently; this leads to genomic instability.

Although loss of XLF, a classical non-homologous DNA end-joining (NHEJ) repair factor, shows strong effects in non-lymphoid cells, in lymphoid cells its absence has only modest effects on V(D)J recombination. This study now shows that in lymphoid cells, two other repair factors — ATM kinase and histone protein H2AX — have functional redundancy with XLF. Thus, mice deficient in both ATM and XLF have compromised conventional NHEJ, although alternative end-joining is retained. The results hint that the redundant function in end-joining that XLF has with both ATM and H2AX may have to do with an ATM role in chromatin accessibility.

Scientists with disabilities seek ways to level the playing field.

William Ja changed his focus from chemistry to biology, and found success.

Domestic bliss?