Volume 467 Issue 7316, 7 October 2010

African nations are laying foundations to extend the use of GM technology on the continent.

Amateur scientists who experiment at home should be welcomed by the professionals.

Francis Collins explains why the NIH is launching a bid to help some doctoral students dramatically reduce the time required to start an independent career.

The week in science.

UK pioneer of in vitro fertilization wins medicine honour.

Research on carbon sheets scores Nobel Prize in Physics.

Researchers are divided after a vote to combine work on drugs and alcohol in one unified body.

The US Supreme Court will rule on sweeping background checks on scientists at the Jet Propulsion Laboratory.

Susan Reverby describes her finding that several hundred Guatemalans were exposed to syphilis by the US Public Health Service.

Major release of maps charting non-genetic modifications goes beyond DNA in a bid to beat complex human disease.

Greens highlight industry links in bid to discredit European food agency.

After a near-death crisis, the best gravity sensor in space is back to full strength, providing data that will keep scientists on the level.

Amateur hobbyists are creating home-brew molecular-biology labs, but can they ferment a revolution?

Biologists studying the evolution of social behaviour are at loggerheads. The disputes — mainly over methods — are holding back the field, says Samir Okasha.

Stephen Hawking and Leonard Mlodinow suggest our Universe isn't all that special, finds Michael Turner.

Swarms teach us that leaders should create conditions for collective decisions, learns John Whitfield.

From physiology to physics, a stirring exhibition reflects 300 years of science in Berlin, discovers Alison Abbott.

Interfaces can have quite different properties from those of their constituent materials. But it's surprising that the adsorption of a single organic molecule onto a magnetic surface can drastically modify that surface's magnetism.

The bacterium Clostridium difficile can cause life-threatening human disease. The question is which of the organism's two toxins is the more crucial to its pathogenicity. The answer is one or the other, or both. See Letter p.711

Methods for trapping tiny particles are increasingly needed, especially for biological assays, but they often involve complicated apparatus. An approach has been discovered that could simplify matters considerably. See Letter p.692

Purification of the human tumour-suppressor protein BRCA2, which is crucial for DNA repair, has been a formidable challenge owing to its large size. That mission is now accomplished, providing biochemical insight. See Article p.678

The detection of unexpected changes in the Sun's spectral irradiance during the declining phase of the most recent solar cycle, and their implications for Earth's atmosphere, are intriguing. But they must be viewed as provisional. See Letter p.696

How do we tell red from green? Work on the primate retina shows how neural circuitry combines signals from individual cone photoreceptor cells to provide the basic building blocks for colour vision. See Article p.673

Colour perception arises from the comparison of signals from different cone types, but how these inputs are combined by ganglion cells, which transmit the output of the retina, has been an issue of contention. Using large-scale multi-electrode arrays and fine-grained visual stimulation, these authors map out the locations and types of single-cone inputs to entire populations of ganglion cells, resulting in input–output maps at an unprecedented resolution and scale.

The two hereditary breast cancer susceptibility genes, BRCA1 and BRCA2, have roles in responding to DNA damage. When they are mutated or absent, genomic instability, a contributory factor to cancer development, results. Studies of BRCA2 have been hampered by its large size, which makes purification of the full-length protein challenging. These authors report the first in vitro characterization of full-length BRCA2 and delineate the different ways by which BRCA2 facilitates RAD51-mediated homologous recombination.

High-resolution observations of early galaxies have shown that two-thirds are massive rotating disk galaxies with velocity dispersions typically five times higher than in today's galaxies. These authors report observations of a sample of rare, high-velocity-dispersion disk galaxies. They find that their velocity dispersions are correlated with their star formation rates, but not their masses or gas fractions, suggesting that star formation is the energetic driver of galaxy disk turbulence at all cosmic epochs.

Electron spins generated by phosphorus dopant atoms buried in silicon represent well-isolated quantum bits with long coherence times, but so far the control of such single electrons has been insufficient to use them in this way. These authors report single-shot, time-resolved readout of electron spins in silicon, achieved by coupling the donor atoms to a charge-sensing device called a single-electron transistor. This opens a path to the development of a new generation of quantum computing and spintronic devices in silicon.

Many fields would benefit from a simple and efficient method of trapping single particles, but this is extremely difficult when dealing with nanometre-sized objects in solution. These authors show that grooves and pockets etched into fluidic channels that acquire a charge on exposure act as highly effective electrostatic traps. With further optimization, this trapping concept could allow contact-free confinement of single proteins and nanoparticles, their sorting and fractionation, or assembly into high-density arrays.

Radiative forcing over an '11-year' solar cycle is thought to be in phase with related influences on climate, but recent satellite data reveal a surprising spectral component in solar variability. These authors show that these spectral variations lead to decreases in ozone below 45 km and increases above. As a consequence, radiative forcing of surface climate is out of phase with solar activity, suggesting that a major revision of our current understanding of solar forcing of climate may be required.

These authors use a scaling argument derived from a model of heat transfer in subduction zones to argue that the locations of volcanic arcs cannot be explained by the release of fluids in reactions taking place near the top of the slab. Instead, they conclude that the sharpness of the volcanic fronts, together with the systematics of their locations, require that arcs be located above the place where the boundary defined by the anhydrous solidus makes its closest approach to the trench.

Temperature increase does not have a linear effect on an organism's biology. These authors use observed global temperature change to calculate the change in metabolic rate for ectotherms. Despite smaller temperature increases in the tropics, these areas, which contain the largest proportion of biodiversity, are likely to experience just as much change in metabolic rate.

Cells that make up the liver are known to be polyploid. These authors show that mouse hepatocytes can increase and decrease their ploidy in vivo; increases occur as a result of failed cytokinesis, and decreases occur as a result of multipolar mitosis. The resulting genetic heterogeneity might be advantageous following hepatic injury, allowing the selection of 'genetically robust' cells from a pre-existing pool of diverse genotypes.

Clostridium difficile, an important nosocomial pathogen, produces two toxins. Studies with purified toxins have indicated that only toxin A is important for pathogenesis, but recently it has been suggested that toxin B causes the majority of the disease symptoms in the context of a bacterial infection. These authors demonstrate that both toxins are important for disease and will need to be considered for diagnosis and treatment.

Centrioles are essential for the formation of centrosomes, cilia and flagella. The centriolar protein Polo-like-kinase 4 (Plk4) is a key regulator of centriole biogenesis and for maintaining constant centriole number in cells. These authors show that the centriolar protein Asterless (CEP152 in humans) interacts with Plk4 and Sas-4. They find that Asl functions as a scaffold for Plk4 and Sas-4 that facilitates self-assembly and duplication of the centriole, and organization of pericentriolar material.

The chromosomal passenger complex (CPC) coordinates several processes during cell division, including chromosome bi-orientation and cytokinesis, and its proper localization is crucial. These authors provide a mechanism for its localization to the inner centromere. Cdk1–cyclin-B-dependent phosphorylation of the CPC promotes binding to shugoshin, which the authors define as a conserved centromeric adaptor of the CPC. This mechanism is conserved between fission yeast and human cells and highlights a crucial role of Cdk1–cyclin B in chromosome bi-orientation.

The formation of filamentous F-actin, through polymerization of globular G-actin, is essential for processes such as cell motility and muscle contraction. These authors report the structure of F-actin as visualized by electron cryomicroscopy, and build a complete atomic model of F-actin. This new structure will improve our understanding of the mechanism of actin assembly and disassembly.

The scaffolding protein symplekin affects the initiation and termination of transcription and is involved in cleavage and polyadenylation at the 3′ ends of precursor messenger RNAs. These authors have solved the structure of a ternary complex of symplekin, a short peptide mimicking the phosphorylated carboxy-terminal tail of RNA polymerase II, and Ssu72, which dephosphorylates this residue. The structure suggests explains how Ssu72 binding can facilitate polyadenylation activity when 3′-end processing is coupled to transcription.

In Escherichia coli, the uptake of L-fucose, an important source of carbon for microorganisms, is mediated by a proton symporter from the major facilitator superfamily (MFS). These authors report the first X-ray crystal structure of the outward-open conformation of an MFS proton transporter, FucP. Building on previous work, they develop a working model for how the substrate is recognized by the transporter and how the protein mediates L-fucose/proton symport.

Unionizing has become more common at US campuses, but postdocs should weigh up the pros and cons of membership.

US congressional resolution raises awareness about postdocs.

HHMI boosts plant science.

Award to cover travel expenses for collaboration or coursework.

The high price of fashion.