Volume 539 Issue 7630, 24 November 2016

But grave challenges remain before the promise of individually tailored medicine becomes reality.

The SESAME synchrotron shows a way towards greater trust and cooperation in the Middle East.

Ahead of a key meeting on endocrine-disrupting chemicals, Leonardo Trasande argues that policy must follow the science.

The week in science: 18–24 November 2016.

SESAME project is set to revolutionize science in the region but is strapped for cash.

Worries include job prospects, discrimination — and safety.

Drilling into Mexico’s Chicxulub basin also finds shattered rock where underground life could thrive.

The move by Chinese scientists could spark a biomedical duel between China and the United States.

Cap at current spending levels could spell ‘end of science in Brazil’, researchers say.

Project to sequence the DNA of more than 1,000 species seeks to reveal how bats learn to communicate.

Elaina Tuttle spent her life trying to understand the bizarre chromosome evolution of a common bird — until tragedy struck.

Rethink electron microscopy to build quantum materials from scratch, urge Sergei V. Kalinin, Albina Borisevich and Stephen Jesse.

Pay more attention to developing thin, mass-produced, affordable photovoltaic devices, urge Yi-Bing Cheng and colleagues.

Sue Nelson delights in Dava Sobel's account of a rare band of human computers.

Alison Abbott hails a memoir from Italian senator and biologist Elena Cattaneo, scourge of pseudoscience.

H. Charles J. Godfray is inspired by the scientific memoir of late island ecologist Ilkka Hanski.

Repair enzymes must communicate across hundreds of nucleotides to undo errors made during DNA replication. Imaging reveals that the enzymes do this by forming a series of ring-like clamps that diffuse along the DNA. See Letter p.583

Organic semiconductor devices require good electrical contacts with conducting materials, but such contacts are often inefficient. An approach that tackles this problem will enable a wide range of applications. See Letter p.536

Observations of a real-time invasion of Australia by Asian honeybees demonstrate how natural selection can allow a small founding population to overcome the genetic odds stacked against success.

Previous observations showed that friction on graphene increases gradually when a probe starts to slide across the material's surface. Simulations now reveal that this effect is related to bending of the graphene sheet. See Letter p.541

Injured blood vessels are repaired by vascular smooth-muscle cells. It emerges that the protein Fat1 regulates the proliferation of these cells by inhibiting the function of mitochondria. See Letter p.575

A biocompatible probe that combines fluorescent nanodiamonds and gold nanoparticles allows cells to be imaged using both optical and electron microscopy techniques, opening up fresh opportunities for biological research.

Plants and bacteria battle for control of water during leaf infection, as is demonstrated by a bacterial species that manipulates plant cells to create a water-rich environment that promotes bacterial growth. See Article p.524

The interplay between spin–orbit coupling and two-dimensionality has led to the emergence of new phases of matter, such as spin-polarized surface states in topological insulators, interfacial chiral spin interactions, and magnetic skyrmions in thin films, with great potential for spin-based devices.

Alx3-induced modulation of Mitf expression alters melanocyte differentiation and gives rise to the hair colour differences underlying the repeated evolution of dorsal stripes in rodents.

A combination of high humidity and bacterial effectors, such as Pseudomonas syringae HopM1, creates an aqueous environment in the apoplast of immunodeficient Arabidopsis thaliana that allows non-pathogenic P. syringae strains to become virulent pathogens.

The mystery of how bacteria that lack motile structures such as pili or flagella can ‘glide’ along surfaces is solved by a detailed description of the bacterial focal adhesion complex and its associated protein machinery.

A general strategy for producing solution-processed doped polymers with the extreme work functions that are required to make good ohmic contacts to semiconductors is demonstrated in high-performance light-emitting diodes, transistors and solar cells.

Atomistic simulations reproduce experimental observations of transient frictional strengthening of graphene on an amorphous silicon substrate, an effect which diminishes as the number of graphene layers increases.

In the chemical industry, it is often necessary to activate carbon–carbon bonds in order to synthesize complex organic molecules, but this is challenging when starting with simple five- or six-membered carbon rings; a new method uses a rhodium pre-catalyst and an amino-pyridine co-catalyst, enabling an overall energetically favourable reaction that involves activation of carbon–carbon bonds plus activation of carbon–hydrogen bonds.

Polarity reversals caused by dynamo waves are demonstrated in a magnetohydrodynamic model that is relevant to planetary cores, suggesting a possible mechanism of geomagnetic reversals.

Cannabinoids affect CB₁ receptors on the mitochondrial membranes in the brain, triggering a decrease in downstream cAMP-dependent signalling; this leads to a decrease in brain mitochondrial activity and to cannabinoid-induced amnesia.

The authors have designed modular synthetic hydrogel networks for mouse and human intestinal stem cell cultures that support intestinal organoid formation.

Apoptotic intestinal epithelial cells can be sampled by lamina propria phagocytes, leading to distinct phagocyte-type-specific anti-inflammatory gene signatures and dendritic-cell-mediated induction of regulatory T cells.

Macrophage-derived insulin-like growth factor enhances the uptake of microvesicles by non-professional phagocytes, such as airway epithelial cells and fibroblasts, thereby dampening tissue inflammation.

Fragments of the atypical cadherin Fat1 accumulate in the mitochondria of vascular smooth muscle cells where they reduce respiration, leading to a regulated proliferative response to arterial injury.

SCAF1 is always required for the interaction between the respiratory chain complexes III and IV, and in animals carrying only the short isoform of SCAF1, the respirasome is absent in most tissues, with the exception of heart and skeletal muscle, where COX7A2 is present instead of SCAF1.

MutS and MutL—the highly conserved core proteins responsible for the repair of mismatched DNA—form sequential stable sliding clamps that together modulate one-dimensional diffusion along the DNA and, with MutH, facilitate the search for a distant excision initiation site.

Drosophila have two pathways for PIWI-interacting RNA (piRNA) 3′-end formation—depending on which pathway is used, piRNA biogenesis is directed towards either cytoplasmic or nuclear PIWI protein effectors, which balances post-transcriptional versus transcriptional transposon silencing.

Characterization of the first Per-ARNT-Sim enzyme, a haem-dependent oxidative N-demethylase.

The political arena need not be off-limits to scientists.

Homing signal.