Volume 538 Issue 7626



News Features

The plight of young scientists p.443

A special issue explores how the research enterprise keeps early-career scientists from pursuing the most important work, and what can be done to help.

doi: 10.1038/538443a

News & Views

Precision timing in a cell p.462

A 16-year-old synthetic genetic circuit that produces gene-expression oscillations in bacterial cells has been given an upgrade, making it an exceptionally precise biological clock. See Letter p.514

doi: 10.1038/nature19478

Twenty-five years of low-cost solar cells p.463

In 1991, an energy-efficient solar cell was reported that was both simple in design and relatively inexpensive. This invention has since inspired the development of solar cells that have even higher efficiencies.

doi: 10.1038/538463a

Female genital cutting under the spotlight p.465

Variations in opinion between members of a community can be exploited to facilitate desirable changes in attitude, as exemplified by films that explore different beliefs about female genital cutting. See Letter p.506

doi: 10.1038/nature19482

Birth of stellar siblings p.466

Binary and multiple star systems result from the fragmentation of dense material in young molecular clouds. Observations reveal that this can occur on small scales, supporting a previous model of star formation. See Letter p.483

doi: 10.1038/538466a

Deep neural reasoning p.467

The human brain can solve highly abstract reasoning problems using a neural network that is entirely physical. The underlying mechanisms are only partially understood, but an artificial network provides valuable insight. See Article p.471

doi: 10.1038/nature19477

Ancient avian aria from Antarctica p.468

A discovery of the sound-producing vocal organ known as the syrinx in a bird fossil from the end of the 'age of dinosaurs' highlights the anatomical basis for myriad aspects of avian social and behavioural evolution. See Letter p.502

doi: 10.1038/nature19480



Fossil evidence of the avian vocal organ from the Mesozoic p.502

Birds make sound in the syrinx, a unique vocal organ situated deep in the chest, but little is known about the evolution of this structure; a fossilized Cretaceous age syrinx from Antarctica is described from a species that might have been capable of making a goose-like honking sound.

doi: 10.1038/nature19852

Synchronous long-term oscillations in a synthetic gene circuit p.514

The first synthetic genetic oscillator or ‘repressilator’ is simplified using insights from stochastic theory, thus achieving remarkably precise and robust oscillations and informing current debates about the next generation of synthetic circuits and their potential applications in cell-based therapies.

doi: 10.1038/nature19841