Research articles

To fully catalogue rare genetic variation in humans, many samples need to be examined. In this study, Coventryet al. resequenced two genes, KCNJ11 and HHEX, in 13,715 humans, and concluded that most of the sequence variation arose recently and that variation is greater than expected.

Continental export of silicon to the coast is linked to ocean carbon sinks, but terrestrial silicon fluxes have not been quantified. Here, human deforestation and cultivation of the landscape are shown to be the most important factors in silicon mobilization in temperate European watersheds.

Much effort has been devoted to the generation of rice plants with short stature to improve grain yield and increased resistance to lodging. Through quantitative trait analysis, these authors identify a gene—STRONG CULM2—that confers increased grain yield, culm strength and spikelet number in rice.

Objects moving through fluids and granular media experience drag forces that determine their dynamics. The authors consider the case of multiple objects moving through a low-density granular material and show that their dynamics are cooperative.

The imaging of magnetic domains in three-dimensional solids has been hampered by a lack of suitable methods. The authors show that Talbot-Lau neutron tomography is capable of visualizing the domain structure of an iron silicide bulk crystal.

The Arctic Mid-Ocean Ridge spreads extremely slowly and hydrothermal vent fields have not been reported in its vicinity. Pedersenet al. describe a black smoker vent field with large hydrothermal deposits and novel fauna distinct from those found in similar environments in the Atlantic.

Lenses with superior performance with respect to conventional uniform materials are desirable. The authors show a three-dimensional lens, made of multilayered metamaterials and based on approximate transformation optics, which works in different polarizations at broad viewing angles and with wide bandwidth.

Thioredoxin binding protein-2 (TBP-2) mutant mice have abnormal insulin sensitivity and secretion. In this study, TBP-2-null obese mice are shown to have improved insulin sensitivity and glucose intolerance, suggesting a potential role for TBP-2 inhibition in diabetes treatment.

Colloidal suspensions are important in the pharmaceutical and food industries. Here, the breaking of filaments of a colloidal liquid under tensile loading is shown to be closely related to the jamming transition seen in its shear rheology; surprising viscoelasticity is also observed in the fluid under tension.

Water is composed of the electrochemically active species, H⁺ and OH⁻, but has not been used as an active electronic material. In this study, a field-effect transistor is developed that uses water-infiltrated nanoporous glass as the gate insulator; this new application of water may be useful in electronics and energy storage.

Fluorescent proteins are widely used in molecular biology to visualize protein expression and localization. Here, Krizet al. describe an efficient and flexible modular plasmid-based eukaryotic expression cloning strategy for the homogeneous expression of several fluorescent proteins in one cell.

Invasive species are usually thought to originate from outside a country's borders. Here, using a self-organizing map, Paini and co-workers show that the species most likely to 'invade' the USA are already firmly established within the country, suggesting the need for biosecurity measures within national borders.

The development of optical information processing depends on the demonstration of silicon-based all-optical circuit components. Here, the authors show a monolithic pulse compressor, compatible with current electronic processing technologies, which is able to function at low power input.

Fusion proteins containing blue-light-activated domains have been used as molecular switches to investigate cell signalling, but molecular understanding of the transduction pathway is lacking. Here, MD simulations are used to elucidate the transduction mechanism in a light oxygen voltage2-Ja photosensor.

Enzyme function is often dependent on fluctuations between inactive and active states. Olsson and Wolf-Watz show that switching between the inactive and active states of adenylate kinase is associated with partial unfolding/refolding of the enzyme.

The influenza virus life cycle relies on sialidases, which are classified as group-1 or group-2, depending on the flexibility of the '150-loop'. In this study, chemical compounds are developed, which lock open the '150-loop', selectively inhibiting the activity of group-1 sialidases.

The drug transporter AcrB is a component of the tripartite efflux system AcrB–AcrA–TolC, which is important in multidrug-resistantEscherichia coli. Takada and co-workers used molecular simulations to further reveal the mechanism of drug export.

The structure of the superconducting gap of iron pnictide superconductors is controversial. In this paper, angle-resolved specific heat measurements are used to show that the gap is anisotropic, which is consistent with an extended s-wave model of superconducting pairing.

Superantigens are bacterial toxins that interact with host immunoreceptors. Salineet al.report the X-ray structure of staphylococcal enterotoxin H in complex with its human receptors, MHC class II and the T-cell receptor, providing new insights into superantigenic T-cell activation.

The spatial scale over which metal–insulator transitions happen is not known, despite the importance of this phenomenon in basic and applied research. The authors show that in chromium-doped V₂O₃, with decreasing temperature, microscopic metallic domains coexist with an insulating background.