Volume 462 Issue 7275, 17 December 2009

A proposed author ID system is gaining widespread support, and could help lay the foundation for an academic-reward system less heavily tied to publications and citations.

It will take time to assess the value of fresh approaches to science and technology studies.

The Japanese winners of Nature's mentoring awards have the universal qualities of outstanding advisers.

The week in science

NASA gets cash to replace a failed carbon-emissions observatory, but concerns remain over future funding.

Overspend threatens to curtail science outreach activities.

Next-generation sequencing technologies tackle iconic bear.

Additional detail could help bring woodland into a future climate treaty.

Academics rally to protest over assessment changes.

Science council recommends funding for research threatened by budget cuts.

Insurgent attacks follow a universal pattern of timing and casualties.

NIH director bows to restrictions on use of cell lines.

President Sarkozy uses 'big loan' to push his reform agenda.

A network of social scientists in the United Kingdom is seeking better ways to study the work of biologists. But, asks Colin Macilwain, can it earn its subjects' trust?

Dedicated scientists are working hard to close the gaps, fix the errors and finally complete the human genome sequence. Elie Dolgin looks at how close they are.

Decaying infrastructure is an urgent threat that scientists and engineers must help to address, says Colin Macilwain.

Discussion needs to be open about how exploitation of Earth's internal heat can produce earthquakes, says Domenico Giardini, so that the alternative-energy technology can be properly utilized.

A collaborative effort between a photographer and a chemist could show scientists how to make the small scale more intuitive, says Jeremy Baumberg.

The hunt for Earth-like worlds has taken a major step forward with the discovery of a planet only 2.7 times larger than Earth. Its mass and size are just as theorists would expect for a water-rich super-Earth.

When the replication machinery copies DNA, it must unwind the double helix in one direction while synthesis of one of the strands proceeds in the other. Making transient DNA loops may solve this directional dilemma.

A merger of data and modelling using a probabilistic approach indicates that sea level was much higher during the last interglacial than it is now, providing telling clues about future ice-sheet responses to warming.

Tagging of DNA-damage-associated proteins by ubiquitin is key to coordinating the DNA-damage response. The ubiquitin-related protein SUMO is revealed as a crucial regulator of ubiquitylation in DNA repair.

Flat microstructures can be designed to spontaneously fold into three-dimensional shapes. Computer simulations of water droplets on sheets of carbon atoms now extend this concept to the nanometre scale.

Imaging of brain structures in living mice reveals that learning new tasks leads to persistent remodelling of synaptic structures, with each new skill associated with a small and unique assembly of new synapses.

An imaging technique has been demonstrated that blends the principles of conventional light and electron microscopy. It renders images with nanometre and femtosecond space-time resolution.

Leading anthropologist of his generation.

Sea levels during the last interglacial stage (about 125 kyr ago) are known to have been higher than today, and may serve as a partial analogue for anthropogenic warming scenarios. However, because local sea levels differ from global sea level, accurately reconstructing past global sea level requires an integrated analysis of globally distributed data sets. An extensive compilation of local sea level indicators and a statistical approach are now used to estimate global sea level during the last interglacial.

The effect of sequence variants on phenotypes may depend on parental origin. Here, a method is developed that takes parental origin — the impact of which, to date, has largely been ignored — into account in genome-wide association studies. For 38,167 Icelanders genotyped, the parental origin of most alleles is determined; furthermore, a number of variants are found that show associations specific to parental origin, including three with type 2 diabetes.

The quantitative description of microbial growth using a few measurable parameters is an important challenge in systems biology. Extracellular glucose sensing and uptake initiate the budding yeast's growth on glucose, but conventional growth models focus almost exclusively on glucose uptake. By uncoupling these two parameters, the interaction between glucose perception and import, rather than their individual actions, is now shown to determine the central features of growth.

The thermodynamically uphill uptake of glutamate from the synaptic cleft into the cytoplasm of glia and neuronal cells is carried out by glutamate transporters. The conformational transition of the transporters between outward and inward facing states is crucial for this process to occur. Here, the crystal structure of a double cysteine mutant of a bacterial homologue of glutamate transporters, trapped in the inward facing state by cysteine crosslinking, is described.

The protein encoded by the breast cancer susceptibility gene BRCA1 participates in the DNA damage response and acts as a ubiquitin ligase; however, its regulation remains poorly understood. The ligase activity of BRCA1 is now shown to require PIAS-mediated modification with SUMO, and in the absence of PIAS SUMO ligases, DNA repair is impeded. The data demonstrate that the SUMOylation pathway has a significant role in the mammalian DNA damage response.

A population of extrasolar planets has been uncovered with minimum masses of 1.9–10 times the Earth's mass, called super-Earths, but atmospheric studies can be precluded by the distance and size of their stars. Here, observations of the transiting planet GJ 1214b are reported; it has a mass 6.55 times that of the Earth and a radius 2.68 times the Earth's radius. The star is small and only 13 parsecs away, permitting the study of the planetary atmosphere with current observatories.

The Kuiper belt is a remnant of the primordial Solar System. Small, sub-kilometre-sized, Kuiper belt objects elude direct detection, but the signature of their occultations of background stars should be detectable. Analysis of archival data now reveals an occultation by a body with an approximately 500-metre radius at a distance of 45 astronomical units. The detection of only one event reveals a deficit of sub-kilometre-sized Kuiper belt objects and implies that these small bodies are undergoing collisional erosion.

Feedback is one of the most powerful techniques for the control of classical systems. An extension into the quantum domain is desirable as it could allow the production of non-trivial quantum states and protection against decoherence. Here, real-time feedback control of the motion of a single atom trapped in an optical cavity is demonstrated, by using individual probe photons carrying information about the atomic position to activate a dipole laser.

Optical near-field microscopies can achieve spatial resolutions beyond the diffraction limit, but they cannot match the atomic-scale resolution of electron microscopy. Here, the development of photon-induced near-field electron microscopy — an ingenious blend of these two imaging modalities — opens the way for direct space-time imaging of localized fields at interfaces and visualization of phenomena related to photonics, plasmonics and nanostructures.

A number of lines of evidence suggest that some crustal faults are weak compared to laboratory measurements of frictional strength; however, a satisfactory explanation for this weakness has remained elusive. Laboratory evidence is now provided for a brittle, frictional weakening mechanism based on common fault zone fabrics. Fault samples with well-developed foliation are shown to be extremely weak compared to their powdered equivalents.

Universal patterns can be observed in many collective human activities, including violence. However, the possibility of universal patterns ranging across wars in the size distribution or timing of within-conflict events has barely been explored. Here, the sizes and timing of violent events within different insurgent conflicts are shown to exhibit remarkable similarities, and a unified model of human insurgency — with an interesting resemblance to financial market models — is proposed.

The learning of novel motor skills through repetitive practice is associated with enhanced synaptic efficacy in the motor cortex. However, how motor learning affects neuronal circuitry at the level of individual synapses and how long-lasting memory is structurally encoded in the intact brain remain unknown. Synaptic connections in the living mouse brain are now shown to respond to motor-skill learning and permanently rewire; this could be the foundation of durable motor memory.

Connections between neurons are thought to be remodelled when we learn new tasks or acquire new information; however, it is unclear how neural circuits undergo continuous synaptic changes during learning while maintaining lifelong memories. Here, by following post-synaptic dendritic spines in the mouse cortex, it is shown that a small fraction of new spines induced by novel experience are preserved and provide a structural basis for lifelong memory retention.

The activating E2f transcription factors induce transcription and drive cells out of quiescence, but whether activating E2fs are necessary for normal division is an area of debate. Here, the mouse retina is genetically manipulated to address E2f function in normal cells in vivo. Cells in the mouse retina can still divide in the absence of E2f1–3, although loss of activating E2fs leads to elevated apoptosis; thus, E2fs are not universally required for normal mammalian cell division.

The in vivo function of E2f transcription factors has been a matter of debate. The effects of E2f1, E2f2 and E2f3 triple deficiency are now examined in murine embryonic stem cells, embryos and small intestines. E2f1–3 are shown to function as transcriptional activators in normal dividing progenitor cells; however, contrary to the current view, they are dispensable for cell division but are necessary for cell survival.

Following the formation of a DNA double-strand break (DSB), cells activate the DNA-damage response and recruit a number of proteins to the lesion. Some of these proteins are modified by the attachment of small ubiquitin-related modifier (SUMO). Here, SUMO1, SUMO2 and SUMO3 are shown to accumulate at DSB sites in mammalian cells. SUMO1 and SUMO2/3 accrual requires the E3 ligase enzymes PIAS4 and PIAS1, which promote DSB repair.

DNA is replicated by a replisome containing two DNA polymerase molecules, one of which copies the leading-strand template in a continuous manner while the second copies the lagging-strand template in a discontinuous manner; however, the two strands are synthesized at the same net rate. RNA primers are now shown to be made as DNA is being synthesized and then passed on to the polymerase; to allow for this transfer, the lagging-strand polymerase has a faster rate.

Bias may not be the only reason behind women's under-representation in science, maths and engineering.

Nature recognizes the best of Japan's mentors.

The chase is on.