Reviews & Analysis

The observation of unusually low ozone levels over the Arctic last winter provides reassuring evidence that our knowledge of stratospheric chemistry is robust. Whether such an episode will happen again is an open question. See Article p.469

Plants and fungi follow a complex route to make the vitamin thiamine for carbohydrate metabolism. One of the pathway's protein participants turns out to be a surprising player, sacrificing its own activity in the process. See Letter p.542

A stellar occultation by the dwarf planet Eris provides a new estimate of its size. It also reveals a surprisingly bright planetary surface, which could indicate the relatively recent condensation of a putative atmosphere. See Letter p.493

The Black Death was one of the most devastating pandemics in human history. The first complete genome sequence of the causative Yersinia pestis bacterium provides a fresh perspective on plague evolution. See Letter p.506

The idea that space-time might be fundamentally fuzzy is much debated among theorists. A search for signatures of this effect on light from distant cosmic sources has come up empty-handed, but shows the potential of this approach.

The tendency of hydrophobic surfaces to aggregate in water is often invoked to explain how biomolecules recognize and bind to each other. Water seems to have a much more active role in these processes than had been thought.

The protein Hsp90 is a target of promising anticancer drugs. An analysis of the components of Hsp90 complexes in tumours reveals a path that may lead to predictive assays of drug sensitivity in cancer patients.

The origin of unusually hot stars in a sparse cluster has been attributed to their being members of binary systems rather than stellar collisions. This prompts a rethink of how stars merge when they collide. See Letter p.356

An analysis of neutrino data suggests that there may be additional types of neutrinos beyond the three currently known. If confirmed, the existence of these additional particles could have an impact on astrophysics and cosmology.

Skin-cancer stem cells secrete a factor that organizes a blood-supply system to fuel tumour growth. But the same factor has another sinister function — it stimulates the stem cells to propagate uncontrollably. See Letter p.399

Unlike in other mammals, neuron production in the subventricular region of the human brain becomes depleted in early infancy. This finding calls for a reassessment of the potential role of adult neurogenesis in health and disease. See Letter p.382

Some biological macromolecules can control their own assembly into elegant hierarchical structures. Synthetic supramolecules are catching up fast, promising new advances for optical and biomedical materials. See Letter p.364

Sources of incandescence emit their radiation across a broad spectrum. The finding that metamaterials can be used to tune the sources' emission spectrum makes these emitters an attractive prospect for some applications.

Tumours increase their consumption of the amino acid tryptophan to evade immune control. But how does this work? A study shows that the main product of this consumption binds to a receptor involved in the immune system. See Article p.197

A model proposes that falling sea levels shifted the make-up of volcanic gases on the early Earth, triggering a chain of events that may have allowed photosynthesis in the ocean to oxygenate the atmosphere. See Letter p.229

Quantum computing architectures based on hybrid systems require strong coupling and information exchange between their constituent elements. These two features have been achieved in one such hybrid setting. See Letter p.221

Some fruit odours sexually arouse male fruitflies. The response is mediated by olfactory neurons that are sensitive to food smells and plug into the brain's neural circuit for sexual behaviour. See Letter p.236

Laser light has been used to cool a nanomechanical resonator to its lowest energy state. The result opens the door to testing the principles of quantum mechanics and to applications in quantum information processing. See Letter p.89