Volume 504 Issue 7478, 5 December 2013

Medical testing firms find it is in their best interests to cooperate with regulators.

A physics course that hooked a generation reminds us that teachers need support.

As a flurry of interest in workplace discrimination subsides, efforts to raise awareness and eliminate abuses continue, says Kathleen Raven.

The week in science: Sun-grazer comet fragments; controversial study on GM maize retracted; and China launches a Moon rover.

Sanctions cause increasing shortfall in medicines and vaccines.

Analysis of oldest sequence from a human ancestor suggests link to mystery population.

Method for checking global literature leads to investigation of cancer researcher.

Slothful response from regulators and manufacturers means antibiotic resistance is missed.

Collectors band together to salvage cast-off equipment.

What researchers are learning from an unprecedented survey of mortality in India.

A billion years ago, a huge rift nearly cleaved North America down the middle. And then it failed. Researchers may be getting close to finding out why.

Current theories on the formation of the Moon owe too much to cosmic coincidences, says Robin Canup. She calls for better models and a mission to Venus.

Rob Phillips celebrates the US physicist's seminal series as it nears its 50th anniversary.

Erika Check Hayden ponders a call for schools to embrace genetic information as a priority.

Immunologist who pioneered cell-sorting technology.

Our knowledge of how Earth's natural satellite formed is increasingly being challenged by observations and computer simulations. Two scientists outline our current understanding from the point of view of the satellite's geochemistry and its early dynamical history.

Proliferation-driving mutations in haematopoietic stem cells often result in the loss of stem-cell properties. But at least one common oncogenic mutation seems to enhance both proliferation and stem-cell self-renewal. See Letter p.143

Observations of a high degree of polarization in the immediate optical afterglow of a γ-ray burst indicate that these powerful cosmic explosions carry large-scale, ordered magnetic fields. See Letter p.119

Structures of the heat-sensitive TRPV1 ion channel have been solved using single-particle electron cryo-microscopy, representing a landmark in the use of this technique for structural biology. See Articles p.107 & p.113

As the recipients of the 2013 science Nobel prizes gather in Stockholm to celebrate and be celebrated, News & Views shares some expert opinions on the achievements honoured.

As the recipients of the 2013 science Nobel prizes gather in Stockholm to celebrate and be celebrated, News & Views shares some expert opinions on the achievements honoured.

As the recipients of the 2013 science Nobel prizes gather in Stockholm to celebrate and be celebrated, News & Views shares some expert opinions on the achievements honoured.

As the recipients of the 2013 science Nobel prizes gather in Stockholm to celebrate and be celebrated, News & Views shares some expert opinions on the achievements honoured.

Very little is known about how a G-protein-coupled receptor (GPCR) transitions from an inactive to an active state, but this study has solved the X-ray crystal structures of the human M2 muscarinic acetylcholine receptor bound to a high-affinity agonist in an active state and to a high-affinity agonist and a small-molecule allosteric modulator in an active state; the structures provide insights into the activation mechanism and allosteric modulation of muscarinic receptors.

A high-resolution electron cryo-microscopy structure of the rat transient receptor potential (TRP) channel TRPV1 in its ‘closed’ state is presented; the overall structure of this ion channel is found to share some common features with voltage-gated ion channels, although several unique, TRP-specific features are also characterized.

Using a peptide toxin and small vanilloid agonists as pharmacological probes, high-resolution electron cryo-microscopy structures of rat TRPV1–ligand complexes are solved; these structures highlight conformational differences between TRP and voltage-gated ion channels in their active states, and suggest a dual gating mechanism that may account for the ability of members of the TRP channel superfamily to integrate diverse physiological signals.

The immediate optical afterglow of the γ-ray burst GRB 120308A is highly polarized, showing that γ-ray bursts contain magnetized baryonic jets with large-scale uniform fields that can survive long after the initial explosion.

Although olivine was expected to occur within the deep, south-pole basins of asteroid Vesta, which are thought to be excavated mantle rocks, spectral data from NASA’s Dawn spacecraft show that it instead occurs as near-surface materials in Vesta’s northern hemisphere.

The El Niño propagation asymmetry (in which sea surface temperature anomalies propagate eastwards during an extreme El Niño event) is shown to be caused by the variations in upper ocean currents in the equatorial Pacific Ocean; increased occurrences of the propagation asymmetry may be a manifestation of global greenhouse warming.

The calculated density and seismic structure of the two best-exposed island arc sections (Kohistan and Talkeetna) reveals that the foundering of the lower arc crust produces a sharp seismic discontinuity characteristic of the continental Mohorovičić discontinuity.

The role that epistasis — non-additive interactions between alleles — plays in shaping population fitness is investigated in Drosophila melanogaster; the raw material to drive reproductive isolation is found to be segregating contemporaneously within species and does not necessarily require the emergence of incompatible mutations independently derived and fixed in allopatry.

Expression of more than 15,500 genes individually in a melanoma cell line treated with RAF, MEK, ERK or combined RAF–MEK inhibitors reveals a cyclic-AMP-dependent melanocytic signalling network associated with drug resistance; this may represent a novel therapeutic target for melanoma treatment.

Oncogenic Nras in mouse haematopoietic stem cells can increase the probability of cell division in some cells and decrease it in others; this bimodal activity explains how this single pre-leukaemic mutation can increase proliferation without reducing competitiveness by clonally expanding the rapidly dividing cell population and also promoting long-term self-renewal of stem cells.

Plants defend themselves against attackers by producing bioactive secondary metabolites such as triterpene saponins; here, the endoplasmic-reticulum-associated degradation (ERAD) system is shown to control the activity of HMGR, the rate-limiting enzyme in the supply of the terpene precursor isopentenyl diphosphate, thereby preventing unrestrained saponin production and ensuring the integrity of plant development.

This work identifies a role for intestinal epithelial cell (IEC)-intrinsic expression of histone deacetylase 3 in regulating commensal-bacteria-dependent gene expression and intestinal homeostasis; IEC-specific HDAC3 deficiency gives rise to Paneth cell abnormalities, impaired intestinal barrier function, and increased DSS-induced intestinal inflammation in commensal-bacteria-containing, but not germ-free, mice.

In neonatal mice, susceptibility to infection is due to an enriched subset of arginase-2-expressing CD71⁺ erythroid cells, which suppresses the systemic activation of immune cells, thereby protecting neonates against aberrant inflammation triggered by colonization with commensal microbes.

Brown adipose tissue-enriched lysine methyltransferase EHMT1 is an essential enzyme in the PRDM16–C/EBP-β transcriptional complex that controls brown adipose cell fate and energy metabolism.

Although the roles of pentatricopeptide repeat (PPR) proteins in RNA metabolism are well characterised, the mechanism by which they recognise specific single-stranded (ss)RNAs remains ill-understood; here X-ray crystal structures of maize PPR10 in the presence and absence of ssRNA provide details of the PPR10–ssRNA interaction.

These results reveal the first high-resolution structural analysis of LIMP-2 and, by homology modelling, the structure of SR-BI and CD36, members of the CD36 superfamily of scavenger receptor proteins.

Writing science books for the public is rewarding, but can take a lot of time — and financial gain is uncertain.

Mobile scientists perform better than those who stay in their home nation.

Policy reform needed to boost numbers of minority female science-faculty members.

All-star scientists sought as part of university plan.

Credit where credit is due.

Coastal regions are home to billions of people worldwide, but our intense use is placing them under pressure. This Insight explores some of the factors shaping coastal systems, including flooding by tropical cyclones, ice loss in Greenland, wetland stability, carbon cycling in the coastal ocean, seaweed tides, offshore groundwater reserves and coastal defence in the face of global change.