Volume 537 Number 7619



News Features

News & Views

Designing the ideal opioid p.170

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

doi: 10.1038/nature19424

Slippery when narrow p.171

An experimental technique has been developed to measure water flow through carbon nanotubes. Measurements reveal that flow can be almost frictionless, posing challenges for computer simulations of nanofluidics. See Letter p.210

doi: 10.1038/537171a

Mapping the terrestrial human footprint p.172

An analysis of direct human impacts across Earth's land surface using global satellite images and ground surveys reveals the scale of the 'human footprint' on the world and its changes between 1993 and 2009.

doi: 10.1038/537172a

Violent emissions of newborn stars p.174

Interactions between young stars and their parent molecular clouds are poorly understood. High-resolution observations of the Orion nebula now reveal these interactions, which have implications for star formation. See Letter p.207

doi: 10.1038/537174a

Catalytic spliceosome captured p.175

Spliceosome complexes remove non-coding sequences from RNA transcripts in two steps. A structure of a spliceosome after the first step reveals active-site interactions and evolutionary constraints on these non-coding regions. See Article p.197

doi: 10.1038/nature19422

Fin to limb within our grasp p.176

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

doi: 10.1038/nature19425



Compression and ablation of the photo-irradiated molecular cloud the Orion Bar p.207

One-arcsecond-resolution millimetre-wave images enable the surface of the Orion Bar molecular cloud to be resolved, revealing a fragmented ridge of high-density substructures, photoablative gas flows and instabilities that suggest that the cloud edge has been compressed by a high-pressure wave expanding into the molecular cloud, in contrast to predictions from static equilibrium models.

doi: 10.1038/nature18957

Digits and fin rays share common developmental histories p.225

Hoxa- and Hoxd-deficient zebrafish generated using Crispr/Cas with fate mapping have reduced fin rays and increased endochondral elements, establishing homology between the developmental programs that create fin rays and the wrists and digits of mammals.

doi: 10.1038/nature19322