Reviews & Analysis

The origin of hot Jupiters, large gaseous planets in close orbits around stars, is unknown. Observations suggest that such planets are abundant in stellar clusters, and can result from encounters with other celestial bodies.

T cells of the immune system mount antiviral responses, but if a response fails, a chronic viral infection can develop. It now seems that a T-cell subset in lymphoid immune tissues can control chronic infection. See Letters p.412 & p.417

An Earth-mass planet has been discovered in orbit around Proxima Centauri, the closest star to our Sun. The planet orbits at a distance from the star such that liquid water and potentially life could exist on its surface. See Letter p.437

A heroic effort to characterize the chemistry of actinium, a short-lived radioactive element, reveals surprising differences in behaviour compared with other elements in the actinide series.

Dietary restriction is known to extend lifespan in many species. It has now been shown to reduce DNA damage and extend lifespan in mice modelling human DNA-repair disorders. See Letter p.427

In mice, two fear-associated memories that are created close in time are represented in the brain's amygdala by the activation of overlapping ensembles of neurons. As a result, eliminating the fear of one memory also extinguishes fear of the other.

Meet the octobot, the first robot to be made entirely from soft materials. Powered by a chemical reaction and controlled by a fluidic logic circuit, it heralds a generation of soft robots that might surpass conventional machines. See Letter p.451

There was thought to be little in common between fish fin bones and the finger bones of land-dwellers. But zebrafish studies reveal that hox genes have a surprisingly similar role in patterning the two structures. See Letter p.225

In the 1950s, the discovery of a class of 'living' polymerization reaction revolutionized the field of polymer science by providing a way of controlling the molecular-weight distribution of polymers. The effects reverberate to this day.

The identification of the active site of an iron-containing catalyst raises hopes of designing practically useful catalysts for the room-temperature conversion of methane to methanol, a potential fuel for vehicles. See Letter p.317

The exome is the portion of the genome that encodes proteins. Aggregation of 60,706 human exome sequences from 14 studies provides in-depth insight into genetic variation in humans. See Article p.285

'Overdoped' high-temperature superconductors, which have a high density of charge carriers, were thought to be well understood. An experiment challenges what we know about quantum physics in such systems. See Letter p.309

The development of a drug that mimics the pain-relieving activity of opioid compounds, but has fewer side effects, points to an effective strategy for the discovery of many types of drug. See Article p.185

If a tumour outgrows its blood supply, oxygen levels in its cells decrease. It emerges that this change can alter gene expression by limiting the activity of TET enzymes, which remove methyl groups from DNA. See Article p.63

When and by which paths did early humans migrate into America? An analysis of ancient plant and animal remains revises the timeframe during which a route may have opened between ice sheets in northwest America. See Article p.45

Structural studies provide insight into the mechanisms governing a checkpoint in cell division that prevents chromosomes from segregating before they are properly aligned on a structure called the mitotic spindle. See Article p.431

A solid composite material has been made that conducts electricity through the rapid transport of silver ions, which diffuse faster than in some liquids. The material holds promise for applications in charge-storage devices. See Article p.159

In pancreatic cancer, neighbouring non-cancerous cells degrade their own proteins through a process called autophagy and release amino acids that are then taken up and used by the cancer cells. See Letter p.479