Reviews & Analysis

The masses of nearby spiral galaxies are dominated by invisible 'dark matter'. Surprisingly, galaxies in the distant Universe seem to contain comparatively little of it. See Letter p.397

A global analysis finds that nitrogen fertilizers could be used more efficiently if their international distribution across croplands was altered — a measure that would also decrease nitrogen pollution.

A study showing the effects of land-use quality on the productivity of bumblebee colonies highlights the importance of resource availability across space and time in promoting survival over generations. See Letter p.547

Antiretroviral therapy can keep HIV at bay, but a few cells remain infected, so the disease cannot be cured. The discovery of a protein that marks out these infected cells will facilitate crucial studies of this latent viral reservoir. See Letter p.564

Surgical repair of a detached retina involves the injection of a gas or silicone oil into the eye to hold the retina in place. The development of a gel with more-desirable properties than these substances might improve the success of this procedure.

It emerges that nascent non-coding RNAs transcribed from regulatory DNA sequences called enhancers bind to the enzyme CBP to promote its activity locally. In turn, the activities of CBP stimulate further enhancer transcription.

Periodic oscillations are common in nature but they generally decay or fall out of phase. Two experiments have found evidence for a Floquet time crystal, which is characterized by persistent in-phase oscillations. See Letters p.217 & p. 221

How did the relationship between human societies and their surrounding terrain shape the formation of long-distance trade networks such as the Silk Road? Digital mapping and computer modelling offer insights. See Article p.193

The ultimate limit of classical data storage is a single-atom magnetic bit. Researchers have now achieved the writing and reading of individual atoms whose magnetic information can be retained for several hours. See Letter p.226

The glycoprotein lipocalin 2 is released from the bones of mice in a nutrient-dependent manner and binds to receptors in the brain to suppress appetite. This is the first example of bone-derived signals mediating hunger. See Article p.385

The cellular response to low oxygen levels is regulated by a process in which one protein is ousted from a binding site by another. It emerges that protein disorder allows the displacement to occur remarkably efficiently. See Letter p.447

A remarkable composite material has been made that mimics the structure of tooth enamel. This achievement opens up the exploration of new composite materials and of computational methods that reliably predict their properties. See Letter p.95

Rocks are subjected to increased pressure as they are buried during subduction. Contrary to general belief, a study suggests that peak pressures recorded in subducted rocks might not reflect their maximum burial depths.

A supersolid is a paradoxical and elusive state of matter that has been sought for more than 60 years. Two experiments have now observed its characteristic signatures in ultracold quantum matter. See Letters p.87 & p.91

Aggregates are aberrant, non-functional forms of protein that often build up in cells in response to stress. Organelles called mitochondria have now been found to be active players in the clearance of these protein aggregates. See Letter p.443

The identification of the regulatory protein ENL as essential to an aggressive form of leukaemia provides insight into transcriptional regulation and highlights potential avenues for therapy. See Letters p.265 & p.270

Optimal protein synthesis requires bases in transfer RNAs to be modified. A key modification has been shown to involve an unusual two-step mechanism that entails the sequential activities of two enzymes. See Letter p.494