PPAR? ligands are used to control diabetes, but their anti-diabetic actions are puzzling. Here the authors show that phosphorylation of PPAR? by cyclin-dependent kinase 5 (Cdk5) in mice is linked to obesity induced by high-fat feeding, and that inhibition of the effect in humans by the drug rosiglitazone is closely associated with its anti-diabetic effects. Several anti-diabetic PPAR? ligands directly inhibit the effect, and thus support a more normal non-diabetic pattern of gene expression.

Hitherto, 21-cm emission has been detected in galaxies only to redshift 0.24, although it is possible to measure the aggregate emission from many more distant, unresolved sources in the 'cosmic web'. Here the authors report a three-dimensional 21-cm intensity field at redshift 0.53–1.12. They co-add neutral-hydrogen emission from the volumes surrounding about 10,000 galaxies to detect the aggregate 21-cm glow at a significance of approximately four standard deviations.

Graphene nanoribbons (GNRs) have structure-dependent electronic properties that make them attractive for the fabrication of nanoscale electronic devices, but exploiting this potential has been hindered by the lack of precise production methods. Here the authors demonstrate how to reliably produce different GNRs, using precursor monomers that encode the structure of the targeted nanoribbon and are converted into GNRs by means of surface-assisted coupling.