Reviews & Analysis

A third gravitational-wave signal has been detected with confidence, produced again by the merger of two black holes. The combined data from these detections help to reveal the histories of the stars that left these black holes behind.

It emerges that people reached Australia earlier than was thought. This finding casts light on the technology used by the travellers, and their possible interactions with animal species that became extinct. See Article p.306

Complex nanoscale magnetization patterns have been resolved in 3D using advanced X-ray microscopy. This could spur the design of magnetic devices that have unique properties and functions. See Letter p.328

A major advance in the quantum theory of solids allows materials to be identified whose electronic states have a non-trivial topology. Such materials could have many computing and electronics applications. See Article p.298

The use of state-of-the-art techniques to study neuronal activity during a navigational task involving sound stimuli broadens our understanding of how neuronal populations produce complex behaviours. See Letter p.92

The molecule fructose-1,6-bisphosphate, which is produced during glucose metabolism, has been shown to mediate cellular sensing of glucose deprivation through an unexpected mechanism. See Letter p.112

Progress is being made in the use of personalized approaches to create both in vitro and in vivo tumour models that could be used to aid cancer drug-treatment decisions and increase our understanding of how tumours respond to therapy.

Quantum physics ultimately constrains how well sensors of position, speed and acceleration can perform. A hybrid quantum system that avoids these constraints could give rise to improved sensor technologies. See Letter p.191

Trace elements are enriched in plants by natural processes, human activities or both. An analysis of mercury in Arctic tundra vegetation offers fresh insight into the uptake of trace metals from the atmosphere by plants. See Letter p.201

The development of a protocol for isolating and expanding the cell population that lines bile ducts has enabled the in vitro generation of bioengineered ducts. These can replace native bile ducts when transplanted into mice.

Immune cells called T cells help immune-system B cells mature to produce antibodies. This entails signalling between cells using the molecule dopamine — a surprising immunological role for this neurotransmitter. See Article p.318

Hair-like sensors are suspected to aid fish navigation in complex environments. Laboratory experiments and computational simulations reveal how these sensors can detect water flow to direct the swimming responses of fish. See Letter p.445

A sophisticated analysis in mice of how inputs to neurons from other neurons are distributed across individual cells of the brain's visual cortex provides information about how mammalian vision is processed. See Letter p.449

DNA is packaged in the cell as chromatin, which folds into organized domains. Mapping of chromatin contacts in single cells sheds light on the dynamic evolution of these domains between cell divisions. See Article p.61

Microscopic fossils show that, from 10,400 to 7,500 years ago, upwelling of a water mass called Circumpolar Deep Water destabilized Antarctic ice shelves — a finding that advances our understanding of ice-sheet retreat. See Article p.43

Integrated circuits usually have only one layer of electronic devices, which limits their performance and functionality. A 3D integrated circuit that incorporates multiple device layers enables a wealth of applications. See Letter p.74

The T cells of the immune system can destroy tumours, but their activation can be inefficient. Vaccines that exploit tumour mutations elicit robust T-cell responses to tumours, with potential clinical benefits. See Letters p.217 & p.222