Numbers matter p.263

doi: 10.1038/520263b

Close the deal p.263

doi: 10.1038/520263a

Announcement: Time to tackle cells’ mistaken identity p.264

doi: 10.1038/520264a

UK funders demand strong statistics for animal studies p.271

doi: 10.1038/520271a

Canadians baulk at reforms to health-research agency p.272

doi: 10.1038/520272a

The printed organs coming to a body near you p.273

doi: 10.1038/520273a

Iran nuclear deal raises hopes for science p.274

doi: 10.1038/520274a

Leading scientists favour women in tenure-track hiring test p.275

doi: 10.1038/520275a

Rule rewrite aims to clean up scientific software p.276

doi: 10.1038/520276a

The Ras renaissance p.278

doi: 10.1038/520278a

Voices of Hubble p.282

doi: 10.1038/520282a

The complex seeds of metastasis p.298

doi: 10.1038/nature14377

A new recipe for Earth formation p.299

doi: 10.1038/520299a

An extravascular route for tumour cells p.300

doi: 10.1038/nature14382

Streamlining drug synthesis p.302

doi: 10.1038/520302a

A weighty mass difference p.303

doi: 10.1038/nature14381

Recovering the potential of coral reefs p.304

doi: 10.1038/nature14384

A resource for cell line authentication, annotation and quality control p.307

doi: 10.1038/nature14397

Crystal structures of the human adiponectin receptors p.312

doi: 10.1038/nature14301

Two disparate ligand-binding sites in the human P2Y₁ receptor p.317

doi: 10.1038/nature14287

Nuclear ashes and outflow in the eruptive star Nova Vul 1670 p.322

doi: 10.1038/nature14257

An ultrafast rechargeable aluminium-ion battery p.325

doi: 10.1038/nature14340

Multistep continuous-flow synthesis of (R)- and (S)-rolipram using heterogeneous catalysts p.329

doi: 10.1038/nature14343

Icebergs not the trigger for North Atlantic cold events p.333

doi: 10.1038/nature14330

A Mercury-like component of early Earth yields uranium in the core and high mantle ¹⁴²Nd p.337

Recent 142Nd isotope data indicate that the silicate Earth (its crust plus the mantle) has a samarium to neodymium elemental ratio (Sm/Nd) that is greater than that of the supposed chondritic building blocks of the planet. This elevated Sm/Nd has been ascribed either to a ‘hidden’ reservoir in the Earth or to loss of an early-formed terrestrial crust by impact ablation. Since removal of crust by ablation would also remove the heat-producing elements—potassium, uranium and thorium—such removal would make it extremely difficult to balance terrestrial heat production with the observed heat flow. In the ‘hidden’ reservoir alternative, a complementary low-Sm/Nd layer is usually considered to reside unobserved in the silicate lower mantle. We have previously shown, however, that the core is a likely reservoir for some lithophile elements such as niobium. We therefore address the question of whether core formation could have fractionated Nd from Sm and also acted as a sink for heat-producing elements. We show here that addition of a reduced Mercury-like body (or, alternatively, an enstatite-chondrite-like body) rich in sulfur to the early Earth would generate a superchondritic Sm/Nd in the mantle and an 142Nd/144Nd anomaly of approximately +14 parts per million relative to chondrite. In addition, the sulfur-rich core would partition uranium strongly and thorium slightly, supplying a substantial part of the ‘missing’ heat source for the geodynamo.

doi: 10.1038/nature14350

Recovery potential of the world's coral reef fishes p.341

Continuing degradation of coral reef ecosystems has generated substantial interest in how management can support reef resilience. Fishing is the primary source of diminished reef function globally_, leading to widespread calls for additional marine reserves to recover fish biomass and restore key ecosystem functions. Yet there are no established baselines for determining when these conservation objectives have been met or whether alternative management strategies provide similar ecosystem benefits. Here we establish empirical conservation benchmarks and fish biomass recovery timelines against which coral reefs can be assessed and managed by studying the recovery potential of more than 800 coral reefs along an exploitation gradient. We show that resident reef fish biomass in the absence of fishing (B₀) averages ∼1,000 kg ha−1, and that the vast majority (83%) of fished reefs are missing more than half their expected biomass, with severe consequences for key ecosystem functions such as predation. Given protection from fishing, reef fish biomass has the potential to recover within 35 years on average and less than 60 years when heavily depleted. Notably, alternative fisheries restrictions are largely (64%) successful at maintaining biomass above 50% of B₀, sustaining key functions such as herbivory. Our results demonstrate that crucial ecosystem functions can be maintained through a range of fisheries restrictions, allowing coral reef managers to develop recovery plans that meet conservation and livelihood objectives in areas where marine reserves are not socially or politically feasible solutions.

doi: 10.1038/nature14358

Emotional learning selectively and retroactively strengthens memories for related events p.345

doi: 10.1038/nature14106

Thirst driving and suppressing signals encoded by distinct neural populations in the brain p.349

doi: 10.1038/nature14108

The evolutionary history of lethal metastatic prostate cancer p.353

doi: 10.1038/nature14347

A model of breast cancer heterogeneity reveals vascular mimicry as a driver of metastasis p.358

doi: 10.1038/nature14403

SHMT2 drives glioma cell survival in ischaemia but imposes a dependence on glycine clearance p.363

doi: 10.1038/nature14363

Therapy-induced tumour secretomes promote resistance and tumour progression p.368

doi: 10.1038/nature14336

Radiation and dual checkpoint blockade activate non-redundant immune mechanisms in cancer p.373

doi: 10.1038/nature14292

Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation p.378

doi: 10.1038/nature14044

β-Lactam formation by a non-ribosomal peptide synthetase during antibiotic biosynthesis p.383

Non-ribosomal peptide synthetases are giant enzymes composed of modules that house repeated sets of functional domains, which select, activate and couple amino acids drawn from a pool of nearly 500 potential building blocks. The structurally and stereochemically diverse peptides generated in this manner underlie the biosynthesis of a large sector of natural products. Many of their derived metabolites are bioactive such as the antibiotics vancomycin, bacitracin, daptomycin and the β-lactam-containing penicillins, cephalosporins and nocardicins. Penicillins and cephalosporins are synthesized from a classically derived non-ribosomal peptide synthetase tripeptide (from δ-(l-α-aminoadipyl)–l-cysteinyl–d-valine synthetase). Here we report an unprecedented non-ribosomal peptide synthetase activity that both assembles a serine-containing peptide and mediates its cyclization to the critical β-lactam ring of the nocardicin family of antibiotics. A histidine-rich condensation domain, which typically performs peptide bond formation during product assembly, also synthesizes the embedded four-membered ring. We propose a mechanism, and describe supporting experiments, that is distinct from the pathways that have evolved to the three other β-lactam antibiotic families: penicillin/cephalosporins, clavams and carbapenems. These findings raise the possibility that β-lactam rings can be regio- and stereospecifically integrated into engineered peptides for application as, for example, targeted protease inactivators.

doi: 10.1038/nature14100