Volume 543 Issue 7643, 2 March 2017

Accurate and timely information on the flow of people is crucial for policymaking and apolitical interpretations.

After 40 years, 2000 ad deserves to be known for more than Judge Dredd.

Researchers must seek out others’ deposited biological sequences in community databases, urges Franziska Denk.

The week in science: 24 February–1 March 2017.

Authorities and researchers ramp up their efforts to tackle the invasive fall armyworm.

3D reconstructions show a 'crown of thorns' shape stemming from a region linked to consciousness.

World Health Organization publishes list that it hopes will focus development of antibiotics.

Signals have progressed from astronomical peculiarity to mainstream research area.

Lawsuits in India and Argentina seek to reduce drug costs by allowing generic versions of antiviral treatments.

An international group offers guidance to help reduce pain and suffering in animals destined for culling.

A special issue explores the intersection of science and migration.

The biggest concentrations of displaced people lie far from the spotlight.

Displaced researchers face huge challenges making lives abroad, even if they find work.

Strict immigration policies stifle innovation and job creation, cautions Vivek Wadhwa.

Monitoring technologies only add to the political noise over managing mobility, warns Huub Dijstelbloem.

Gemma Galdon Clavell calls for checks and balances to avoid the indiscriminate sharing of personal data.

Michael Grubb finds more breadth than depth in Dieter Helm's study on oil's demise.

Ian T. Baldwin revels in a volume that reminds us of the arsenals of the undergrowth.

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

Many organ surfaces are covered by a protective epithelial-cell layer. It emerges that such layers are maintained by cell stretching that triggers cell division mediated by the force-sensitive ion-channel protein Piezo1. See Letter p.118

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.

Ageing is associated with an increased risk of cardiovascular disease caused by the rupture of inflamed cholesterol plaques in arteries. It emerges that this might be partly due to genetic mutations that cause cancerous changes in white blood cells.

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

Immune cells known as T cells can destroy tumour cells, but their clinical use requires complex preparation and the cells can lose effectiveness over time. A new approach might improve the efficiency of T-cell therapy. See Letter p.113

The biosynthesis of a coenzyme in the microbial production of methane has been determined — completing the biosynthetic pathways for the family of compounds that includes chlorophyll, haem and vitamin B₁₂. See Article p.78

The recent expansion of observational data has changed our understanding of the ocean iron cycle and its linkages with nutrients such as carbon and nitrogen.

Perhaps the earliest known signs of life have been found in Quebec, where features such as haematite tubes suggest that filamentous microbes lived around hydrothermal vents at least 3,770 million years ago.

The genomes of 102 primary pancreatic neuroendocrine tumours have been sequenced, revealing mutations in genes with functions such as chromatin remodelling, DNA damage repair, mTOR activation and telomere maintenance, and a greater-than-expected contribution from germ line mutations.

Intragenic DNA methylation, dependent on Dnmt3b, protects the gene body from spurious entry of RNA Polymerase II and aberrant transcription initiation events.

The enzymes and pathway involved in the biosynthesis of coenzyme F₄₃₀ are identified, completing our understanding of how members of the cyclic modified tetrapyrrole family are constructed.

X-ray detection of an ultrafast outflow of gas is strongly linked with energy emission from the inner accretion disk of a black hole, suggesting that X-rays ionize the outflowing disk wind.

A supersolid with continuous translational symmetry breaking along one direction is realized by symmetrically coupling a Bose–Einstein condensate to the modes of two optical cavities.

Spin–orbit coupling in Bose–Einstein condensates creates a density modulation, which is a stripe phase with supersolid properties.

Nanometre-scale columnar structures in tooth enamel inspire novel nanocomposites containing layers of vertically aligned nanowires, produced by layer-by-layer fabrication and combining high values of both storage modulus and energy dissipation.

Melting experiments with liquid Fe–Si–O alloy at the pressure of the Earth’s core reveal that the crystallization of silicon dioxide leads to core convection and a dynamo.

Neurons that project from the prefrontal cortex to either the nucleus accumbens or paraventricular thalamus receive different inputs, differentially encode reward-predictive cues, and have opposing effects on reward seeking during cue presentation.

Complement-activating glycosylceramide-specific autoantibodies drive a self-propagating cycle of glycosylceramide accumulation and inflammation in Gaucher disease.

Introducing chimeric antigen receptors into the endogenous T-cell receptor locus reduces tonic signalling, averts accelerated T-cell differentiation and delays T-cell exhaustion, leading to enhanced function and anti-tumour efficacy compared to random integrations.

The stretch-activated channel Piezo1 controls homeostatic epithelial cell numbers by activating cells to divide rapidly when under stretch strain from low density, and by activating cells to extrude and die when cells are under crowding strain.

Circular extrachromosomal DNA is found in nearly half of human cancers of a wide variety of histologic types, increasing the copy number of driver oncogenes and intratumoral heterogeneity more effectively than chromosomal amplification and contributing to tumor evolution.

Uniparental disomy in fission yeast is triggered by aberrant expression of gametogenic genes in vegetative cells, and is associated with the activation of meiotic cohesin Rec8 in cells with defects in the RNA interference machinery.

A new approach, time-resolved serial femtosecond crystallography, is used to view the intermediate states of a photosystem complex following illumination, shedding light on proton transfer and O=O bond formation.

Computational biologists are starting to develop user-friendly platforms for analysing and interpreting genetic-sequence data.

Political change is causing scientists worldwide to worry about how immigration law might affect their ability to do research.

Those with PhD and master's degrees win another year to get work or a green card.

Canadian university boosts its diversity hiring efforts.

Parting is such sweet sorrow.