Articles in 2013

Bacterial persistence is one of the major causes of failure of antibiotic treatment, and several toxin–antitoxin modules have been linked to the persistent phenotype. Here, the authors show that HipA toxin causes growth arrest and persistence via phosphorylation of the glutamyl-tRNA-synthetase.

Isolated populations may empower genetic association studies of complex traits. Here, the authors identify a rare cardioprotective APOC3variant in a Greek population isolate and highlight the value of using population isolates to detect rare variants that confer disease risk.

Food security and the conservation of natural ecosystems largely rely on the increase in crop yields. Here, the authors examine global crop yield trends since 1960, and establish a robust statistical framework for estimating historical trajectories and identifying yield plateaus.

Population genetics studies continue to debate whether Ashkenazi Levites originated in Europe or the Near East. Here, Rootsi et al.use whole Y-chromosome DNA sequences to unravel the phylogenetic origin of the Ashkenazi Levite and suggest an origin for the Levite founder lineage in the Near East.

Bioavailable nitrogen is increasing due to human activity, rapidly outpacing increases in another essential nutrient, phosphorous. Peñuelas et al.show that this increasing imbalance between these nutrients is likely to significantly affect life and limit carbon storage in this century.

Determining the link between gene polymorphisms and phenotypic traits is the subject of intense research in agricultural plant science. In this study, Fu et al. conduct RNA sequencing in maize kernels to determine gene polymorphisms, which may aid future research aiming to improve the nutritional value of maize.

The morphology of organic solar cells is crucial to their performance but is difficult to measure. Using a variety of probes, Hedley et al.map the morphology of polymer-fullerene solar cells and find that elongated fibre-like polymer- and fullerene-rich domains are desirable for high performance.

The radioactive element uranium tends to accumulate in wetland soils in the insoluble and immobile tetravalent form. Wang et al. show that uranium(IV) can associate with highly mobile organic- and iron(II)-bearing colloids and that its mobility in organic-rich environments may be severely underestimated.

The inverse spin-Hall effect is important in spintronics as it converts a spin current into charge current in nonmagnetic materials. Here, the authors show signatures of the inverse Rashba–Edelstein effect, a similar effect in two-dimensional interfacial states, in an Ag/Bi bilayer.

Kimberlite, an igneous rock in which the majority of the world’s diamonds are found, has been reported on all major continents barring Antarctica. Yaxley et al. present mineralogical and chemical data that confirms the first bona fidediscovery of kimberlite in the Antarctic.

Magnetic nanoparticles are studied for their potential use in nanomagnetic devices. Here the realization of antiferromagnetic coupling in core-shell nanoparticles adds a new possibility to tune their magnetic properties even without changing the structure or morphology.

Many cancers harbour mutations in the tumour suppressor p53, which often then gains oncogenic functions. Here, the authors show that mutant p53 enhances glycolysis in tumour cells by promoting glucose uptake via a mechanism involving GLUT1, RhoA and ROCK.

Opioid analgesic drugs act at opioid receptors to exert analgesic effects, but they also exert adverse side effects. In this study, the authors show that the TREK-1 potassium channel is responsible for mediating the analgesic effects of morphine but not the adverse side effects.

Ginzburg–Landau theory provides a powerful framework for describing the behaviour of conventional superconductors without detailed microscopic information about them. Bao et al.construct a similar framework for describing spin superconductivity, a recently proposed analogue of conventional superconductivity.

Rydberg atoms can have sizes similar to the wavelength of near-infrared light, yet the electric dipole approximation – in which spatial variations of the light-field phase are ignored – remains valid. Anderson and Raithel explain this by measuring that photoionization of such atoms occurs near the nucleus.

Nuclear magnetic resonance is vital for analysis and diagnostics but suffers from insensitivity as only a small fraction of all NMR-active nuclei are spin-polarized and contribute to the signal. Here Hövener et al. describe an effect that replenishes nuclear spin polarization continuously for a considerably enhanced performance at low field.

Nanostructured solar cells should be designed to balance the photonic and electronic effects together to be highly efficient. Cui et al.demonstrate a solar cell with the all-back-contact design and nanocone structure that uses just 10-μm-thick silicon while achieving efficiencies up to 13.7%.

Quantum coherence effects are often only visible at low temperatures, where dephasing times are not too short. Here Kolarczik et al. show that quantum coherence effects can appear in the reshaping of ultrafast laser pulses passing through quantum dots even at room temperature.

RNA is central to many cellular functions, but in vivo structures of most RNAs are unknown. Here Kwok et al. present a universally applicable method, DMS/SHAPE-LMPCR, to identify structures of low-abundance transcripts in living cells, which reveals important features that are uniquely present in vivo.