Reviews & Analysis

An exquisitely sensitive technique shows that a magnetic field only a few hundred times greater than Earth's can bring an exotic phase of matter known as a quantum spin liquid to an ordered magnetic state. See Letter p.612

The natural pulse of a red-giant star provides crucial insight into what makes it shine. Observations of red giants by the Kepler space telescope shed light on a previously untested prediction of stellar evolution theory. See Letter p.608

A newly discovered variation in the process by which bacteria resist invasion by foreign nucleic acids provides an intriguing parallel between the defence mechanisms of the different domains of life. See Article p.602

Memory T cells remember viruses from previous infections, providing immunity by facilitating the killing of infected cells. For this, they exploit cross-dressing, the transfer of antigens between antigen-presenting cells. See Letter p.629

There are various ways in which apparently 'silent' DNA mutations — those that don't result in a change in the encoded protein — have untoward consequences. A striking example has emerged in a study of Crohn's disease.

Twenty amino acids form the basis of all proteins, but another two genetically encoded amino acids have also been discovered. The biosynthesis of one of these, pyrrolysine, has now been elucidated. See Letter p.647

Winters are colder in northeastern North America and Asia than in other regions at the same latitude. Previous explanations may be incomplete, having overlooked the radiation of atmospheric wave energy. See Letter p.621

Genome-wide association studies are often criticized for providing little insight of immediate physiological relevance. The finding of one such study, which implicates a signalling molecule in schizophrenia, is welcome news. See Letter p.499

The surface warming due to emissions of black-carbon aerosols over the second half of the twentieth century has been identified in observations. These findings will inform debate over the climatic effects of controlling such emissions.

Early cell-lineage decisions during embryonic development differ between mice and cows. This finding calls for a re-examination of developmental variations across mammals, but does not undermine use of the mouse as a model organism.

The modENCODE project uses integrative analysis to annotate genomic elements in the fruitfly and a nematode worm. The first fly data have now been published. See Articles p.473 & p.480 & Letter p.527

Metathesis reactions can be used to make carbon–carbon double bonds — bar one isomeric class. By using new catalysts and balancing out the stabilities of intermediates in the reaction, the elusive isomers can be made. See Article p.461

Anticancer therapies can impair male fertility. Whereas men can opt to freeze their sperm before treatment, young boys don't produce mature sperm and so lack this choice. Work in mice offers hope for such patients. See Letter p.504

The hormone progesterone rapidly activates intracellular signalling in human sperm, regulating key aspects of their physiology. An ion channel unique to the sperm tail seems to relay progesterone's signal. See Letters p.382 & p.387 See Clarification  p.598

The finding that a cobalt oxide insulator's magnetism is similar to that of cuprate superconductors lends support to the popular but contentious idea that stripe-like electronic order is present in the latter materials. See Letter p.341

New clinical trials report the efficacy of two mechanism-based therapies for treating human pancreatic neuroendocrine tumours. Studies in mouse models have contributed to these success stories, and continue to do so.

Apoptotic cell death is essential for the development of multicellular organisms. Paradoxically, three proteins instrumental in apoptosis also collaborate to preserve life by preventing necrotic cell death. See Letters p.363, p.368 & p.373

An enzyme called Dicer is known for its central role in RNA-controlled gene silencing. Mammalian Dicer1, however, also seems to have another function: it maintains visual health by degrading toxic RNA molecules. See Article p.325