Volume 493 Number 7432

Editorials

Knowledge trades p.271

Institutions must carefully evaluate their researchers’ relationships with Wall Street.

doi: 10.1038/493271b

Troubling thoughts p.271

A sustained commitment to mental-health treatment for Fukushima evacuees could also help survivors of future disasters.

doi: 10.1038/493271a

Natural history p.272

Age-old field methods can tell us more about animal behaviour than can laboratory models.

doi: 10.1038/493272a

News

News Features

Fukushima: Fallout of fear p.290

After the Fukushima nuclear disaster, Japan kept people safe from the physical effects of radiation — but not from the psychological impacts.

doi: 10.1038/493290a

News & Views

Evolution: A history of give and take p.308

Fossils of microorganisms from deep-sea sediment cores show that environmental change correlates closely with extinction but not with speciation, producing a nuanced view of the drivers of evolution. See Letter p.398

doi: 10.1038/nature11851

Earth science: Plumbing nickel from the core p.309

Magmas that have erupted at Earth's surface reveal a potential new mantle source. This source, which is rich in nickel and has a primordial helium isotopic content, may have originated at great depth in the mantle. See Letter p.393

doi: 10.1038/nature11852

Stem cells: Surf the waves of reprogramming p.310

Cellular reprogramming to a stem-cell-like state is inefficient and poorly understood, despite its biomedical potential. Detailed molecular analyses of this process are now reported, and should help to overcome these limitations.

doi: 10.1038/493310b

Neuroscience: Memory and the single molecule p.312

Sustained activity of the brain-specific enzyme PKM-ζ is thought to underlie the maintenance of long-term memories. Studies in PKM-ζ-deficient mice, however, cast the importance of this protein into question. See Letters p.416 & p.420

doi: 10.1038/nature11850

Analytical chemistry: Defects visualized in porous solids p.313

The use of confocal fluorescence microscopy to image defects in crystalline, porous solids known as metal–organic frameworks enables the relationship between the number of defects and the materials' properties to be determined.

doi: 10.1038/493313a

Computational materials science: Trustworthy predictions p.314

A method has been developed to compute the precise quantum-mechanical properties of certain insulators. This approach avoids the uncertainties that are intrinsic to predictions made using existing approaches. See Article p.365

doi: 10.1038/nature11767

Articles

Towards an exact description of electronic wavefunctions in real solids p.365

The properties of all materials arise largely from the quantum mechanics of their constituent electrons under the influence of the electric field of the nuclei. The solution of the underlying many-electron Schrödinger equation is a ‘non-polynomial hard’ problem, owing to the complex interplay of kinetic energy, electron–electron repulsion and the Pauli exclusion principle. The dominant computational method for describing such systems has been density functional theory. Quantum-chemical methods—based on an explicit ansatz for the many-electron wavefunctions and, hence, potentially more accurate—have not been fully explored in the solid state owing to their computational complexity, which ranges from strongly exponential to high-order polynomial in system size. Here we report the application of an exact technique, full configuration interaction quantum Monte Carlo to a variety of real solids, providing reference many-electron energies that are used to rigorously benchmark the standard hierarchy of quantum-chemical techniques, up to the ‘gold standard’ coupled-cluster ansatz, including single, double and perturbative triple particle–hole excitation operators. We show the errors in cohesive energies predicted by this method to be small, indicating the potential of this computationally polynomial scaling technique to tackle current solid-state problems.

doi: 10.1038/nature11770

Autism-related deficits via dysregulated eIF4E-dependent translational control p.371

Hyperconnectivity of neuronal circuits due to increased synaptic protein synthesis is thought to cause autism spectrum disorders (ASDs). The mammalian target of rapamycin (mTOR) is strongly implicated in ASDs by means of upstream signalling; however, downstream regulatory mechanisms are ill-defined. Here we show that knockout of the eukaryotic translation initiation factor 4E-binding protein 2 (4E-BP2)—an eIF4E repressor downstream of mTOR—or eIF4E overexpression leads to increased translation of neuroligins, which are postsynaptic proteins that are causally linked to ASDs. Mice that have the gene encoding 4E-BP2 (Eif4ebp2) knocked out exhibit an increased ratio of excitatory to inhibitory synaptic inputs and autistic-like behaviours (that is, social interaction deficits, altered communication and repetitive/stereotyped behaviours). Pharmacological inhibition of eIF4E activity or normalization of neuroligin 1, but not neuroligin 2, protein levels restores the normal excitation/inhibition ratio and rectifies the social behaviour deficits. Thus, translational control by eIF4E regulates the synthesis of neuroligins, maintaining the excitation-to-inhibition balance, and its dysregulation engenders ASD-like phenotypes.

doi: 10.1038/nature11628

Letters

Pulsed accretion in a variable protostar p.378

The infrared luminosity of a young protostar (about 105 years old) is found to increase by a factor of ten in roughly one week every 25.34 days; this is attributed to pulsed accretion associated with an unseen binary companion.

doi: 10.1038/nature11746

Ultrahard nanotwinned cubic boron nitride p.385

The hardness, toughness and chemical stability of the well-known superhard material cubic boron nitride have been improved by using a synthesis technique based on specially prepared ‘onion-like’ precursor materials.

doi: 10.1038/nature11728

Prkcz null mice show normal learning and memory p.416

Genetically removing PKM-ζ in mice has no effect on memory, and despite absence of this kinase, the original peptide inhibitor of PKM-ζ still disrupts memory in these mutant mice; these data re-open the exploration for key molecules regulating maintenance of long-term plasticity processes.

doi: 10.1038/nature11803

PKM-ζ is not required for hippocampal synaptic plasticity, learning and memory p.420

It was proposed that protein kinase M-ζ (PKM-ζ) is a key factor in long-term potentiation (LTP) and memory maintenance on the basis of the disruption of LTP and memory by inhibitors of PKM-ζ; however, here mice that do not express PKM-ζ are shown to have normal LTP and memory, thus casting doubts on a critical role for PKM-ζ in these processes.

doi: 10.1038/nature11802

Asymmetric neurotransmitter release enables rapid odour lateralization in Drosophila p.424

When an odour activates a fly′s antennae asymmetrically, more neurotransmitter is released from olfactory receptor neuron axon branches ipsilateral to the antenna than from contralateral branches. This causes ipsilateral central olfactory neurons to begin spiking earlier and at a higher rate than contralateral neurons, thereby enabling a walking fly to turn towards the odour.

doi: 10.1038/nature11747