Volume 533 Number 7602

Editorials

Mothers’ milk p.145

The safe use of medicines during breastfeeding is not an easy topic to study, but new parents deserve better information on the risks and benefits.

doi: 10.1038/533145a

Market forces p.145

A European plan to commercialize quantum technologies needs a bold goal.

doi: 10.1038/533145b

Smoke out p.146

Scientists should unite over electronic-cigarette regulation, or big tobacco will step in.

doi: 10.1038/533146a

News

News Features

The human side of cybercrime p.164

As cyberattacks grow ever more sophisticated, those who defend against them are embracing behavioural science and economics to understand both the perpetrators and their victims.

doi: 10.1038/533164a

News & Views

Implantation barrier overcome p.182

The early stages of human development are normally hidden within the womb, but improved techniques for culturing embryos from the blastocyst stage promise to make these steps easier to investigate. See Letter p.251

doi: 10.1038/nature17894

Precision pruning of molecules p.183

If organic molecules were trees, then the numerous carbon–hydrogen bonds within them would be leaves. A catalyst that targets one 'leaf' out of many similar other ones looks set to be a huge leap for synthetic chemistry. See Letter p.230

doi: 10.1038/533183a

Ancient air caught by shooting stars p.184

Ashes of ancient meteors recovered from a 2.7-billion-year-old lake bed imply that the upper atmosphere was rich in oxygen at a time when all other evidence implies that the atmosphere was oxygen-free. See Letter p.235

doi: 10.1038/533184a

Quasiparticles on a collision course p.186

Emergent quanta of momentum and charge, called quasiparticles, govern many of the properties of materials. The development of a quasiparticle collider promises to reveal fundamental insights into these peculiar entities. See Letter p.225

doi: 10.1038/533186a

Fresh solutions to the four-body problem p.187

Describing the motion of three or more bodies under the influence of gravity is one of the toughest problems in astronomy. The report of solutions to a large subclass of the four-body problem is truly remarkable.

doi: 10.1038/nature17896

Wired for sex p.188

Analysis of a sensory neural circuit in the roundworm Caenorhabditis elegans reveals that its wiring is sex-specific, and arises through the elimination of connections that are originally formed in both sexes. See Article p.206

doi: 10.1038/nature17898

Review

Palaeoclimatic insights into forcing and response of monsoon rainfall p.191

Palaeoclimatic evidence of monsoon rainfall dynamics across different regions and timescales suggests that monsoon systems exhibit substantial regional variation; meridional temperature gradients are a major driver of monsoon variability, but these gradients are influenced by other, interacting forcing mechanisms, making predictions of future changes in monsoon rainfall highly uncertain.

doi: 10.1038/nature17450

Articles

Sex-specific pruning of neuronal synapses in Caenorhabditis elegans p.206

How sex-specific neuronal circuits are generated during development is poorly understood; here, sensory neurons are identified in the round worm Caenorhabditis elegans, which initially connect in both male- and hermaphrodite-specific patterns, but a specific subset of these connections is pruned by each sex upon sexual maturation to produce sex-specific connectivity patterns and dimorphic behaviours.

doi: 10.1038/nature17977

Interconnected microbiomes and resistomes in low-income human habitats p.212

An analysis of bacterial community structure and antibiotic resistance gene content of interconnected human faecal and environmental samples from two low-income communities in Latin America was carried out using a combination of functional metagenomics, 16S sequencing and shotgun sequencing; resistomes across habitats are generally structured along ecological gradients, but key resistance genes can cross these boundaries, and the authors assessed the usefulness of excreta management protocols in the prevention of resistance gene dissemination.

doi: 10.1038/nature17672

Letters

No Sun-like dynamo on the active star ζ Andromedae from starspot asymmetry p.217

Sunspots are cool areas caused by strong surface magnetic fields that inhibit convection. Moreover, strong magnetic fields can alter the average atmospheric structure, degrading our ability to measure stellar masses and ages. Stars that are more active than the Sun have more and stronger dark spots than does the Sun, including on the rotational pole. Doppler imaging, which has so far produced the most detailed images of surface structures on other stars, cannot always distinguish the hemisphere in which the starspots are located, especially in the equatorial region and if the data quality is not optimal. This leads to problems in investigating the north–south distribution of starspot active latitudes (those latitudes with more starspot activity); this distribution is a crucial constraint of dynamo theory. Polar spots, whose existence is inferred from Doppler tomography, could plausibly be observational artefacts. Here we report imaging of the old, magnetically active star ζ Andromedae using long-baseline infrared interferometry. In our data, a dark polar spot is seen in each of two observation epochs, whereas lower-latitude spot structures in both hemispheres do not persist between observations, revealing global starspot asymmetries. The north–south symmetry of active latitudes observed on the Sun is absent on ζ And, which hosts global spot patterns that cannot be produced by solar-type dynamos.

doi: 10.1038/nature17444

Site-selective and stereoselective functionalization of unactivated C–H bonds p.230

The idea of carbon–hydrogen functionalization, in which C–H bonds are modified at will, represents a paradigm shift in the standard logic of organic synthesis; here, dirhodium catalysts are used to achieve highly site-selective, diastereoselective and enantioselective C–H functionalization of n-alkanes and terminally substituted n-alkyl compounds.

doi: 10.1038/nature17651

The evolution of cooperation within the gut microbiota p.255

Little is known about cooperative behaviour among the gut microbiota; here, limited cooperation is demonstrated for Bacteroides thetaiotaomicron, but Bacteroides ovatus is found to extracellularly digest a polysaccharide not for its own use, but to cooperatively feed other species such as Bacteroides vulgatus from which it receives return benefits.

doi: 10.1038/nature17626

Architecture of the mitochondrial calcium uniporter p.269

The structure of the core region of the mitochondrial calcium uniporter (MCU) is determined by NMR and electron microscopy, revealing that MCU is a homo-pentamer with a specific transmembrane helix forming a hydrophilic pore across the membrane, and representing one of the largest membrane protein structures characterized by NMR spectroscopy.

doi: 10.1038/nature17656

Extra-helical binding site of a glucagon receptor antagonist p.274

The X-ray crystal structure of the transmembrane portion of the human glucagon receptor, a class B G-protein-coupled receptor (GPCR), is solved in the presence of the antagonist MK-0893, with potential implications for the development of therapeutics that target other class B GPCRs.

doi: 10.1038/nature17414