Volume 500 Issue 7464, 29 August 2013

Metaphors are like cheese — often desirable but sometimes full of holes.

Cooperation and a clear set of aims are essential for Europe to be a front runner in making research freely available, says Christoph Kratky.

The week in science: Concerns grow over radioactive leak at Fukushima, NASA revives asteroid-seeking spacecraft, and Amgen takes over Onyx in US$10-billion buyout.

Propellants offer satellites greater efficiency and lower toxicity than liquid hydrazine.

Thomson Reuters suspends journals from its rankings for ‘citation stacking’.

This year’s cyclones grant sea ice a temporary reprieve.

A spate of successful public offerings has raised ample funding for biotechnology — and anxiety about when the good times will end.

Method extends archaeological and linguistic data by tracing early human migration.

Many researchers believe that physics will not be complete until it can explain not just the behaviour of space and time, but where these entities come from.

A mathematical paradox posed in a letter 300 years ago sowed the seed of economic theory by asking what money is worth, explains George Szpiro.

Imagery can help to bridge conceptual boundaries, but it can also cause trouble — as shown by the proliferation of engineering talk in biology, argues Eleonore Pauwels.

Douglas Repetto explores the multilayered aesthetic of sound as art at New York's Museum of Modern Art.

For the 125th anniversary of the Geological Society of America, the Colorado-based musician Jeffrey Nytch has composed a symphony celebrating the geology of the American Rocky Mountains. He talks about Formations, which will be premiered by the Boulder Philharmonic Orchestra on 7 September.

Biophysicist who established the mechanism of muscle contraction.

The finding that the shells of certain algae can contain a signature of low levels of atmospheric carbon dioxide has prompted the discovery of the emergence of this signature in the fossil record. Here, experts discuss the implications of this for climate science and ocean ecology. See Letter p.558

We thought we had figured out dopamine, a neuromodulator involved in everything from learning to addiction. But the finding that dopamine levels ramp up as rats navigate to a reward may overthrow current theories. See Letter p.575

The observation of infrared emission following a short γ-ray burst lends support to the hypothesis that mergers of compact binary systems cause such bursts and produce the heaviest nuclei in the cosmos. See Letter p.547

The discovery of long non-coding RNAs that control the liaisons between a transcription factor with a key role in prostate cancer and its target genes sheds light on how RNAs dictate information flow in the cell nucleus. See Letter p.598

Massive stars, with masses ten or more times that of the Sun, dominate our Universe. Theories of how these stars form are now being challenged by observations of a collapsing cloud of gas and dust.

People whose guts contain a low diversity of bacteria are found to have higher levels of body fat and inflammation than those with high gut-microbial richness. But dietary intervention can help. See Article p.541 & Letter p.585

Analysis of the gut microbial gene composition in obese and non-obese individuals shows marked differences in bacterial richness between the two groups, with individuals with low richness exhibiting increased adiposity, insulin resistance, dyslipidaemia and inflammation; only a few bacterial marker species are needed to distinguish between individuals with high and low bacterial richness, providing potential for future diagnostic tools.

Strong evidence that a kilonova — an event similar to a faint, short-lived supernova — accompanied the short-duration γ-ray burst GRB 130603B provides support for the hypothesis that such bursts are produced by the merger of two compact stellar objects.

A strong inverse correlation between gravity and topography leads to the conclusion that Saturn’s largest moon, Titan, must have a rigid ice shell with an elastic thickness exceeding 40 kilometres.

Artificial spin-ice systems are lithographically fabricated arrays of interacting ferromagnetic nanometre-scale islands; a procedure to thermalize two types of artificial spin ice with different geometries has now been developed, resulting in unprecedentedly large ground-state domains in square lattices and crystallites of ordered magnetic charges in kagome lattices.

New measurements of stable isotope vital effects in fossil coccoliths show a step increase in reliance of coccolithophore photosynthesis on active transport of dissolved bicarbonate in the late Miocene epoch, suggesting both a low threshold for adaptation of coccolithophores to carbon dioxide and a decrease in global carbon dioxide levels at that time.

Multidecadal trends in the terminus position of outlet glaciers along the margin of the East Antarctic ice sheet reveal three epochal patterns of glacier retreat or advance consistent with a rapid and coherent response to air temperature and sea-ice trends.

An anaerobic methanotroph (ANME-2d) can perform nitrate-driven anaerobic oxidation of methane through reverse methanogenesis, using nitrate as the terminal electron acceptor, and nitrite produced by ANME-2d is reduced to dinitrogen gas through a syntrophic relationship with an anaerobic ammonium-oxidizing bacterium.

Whole-genome whole-population sequencing is used to examine the dynamics of genome-sequence evolution in Saccharomyces cerevisiae populations for 1,000 generations; this reveals patterns of sequence evolution driven by pervasive genetic hitchhiking and interference, and shows that beneficial mutations that escape drift and increase in frequency typically occur in cohorts.

Cyclic voltammetry reveals an extended mode of reward-predictive dopamine signalling in the striatum as rats navigate; signals increase as the rats approach distant rewards, instead of showing phasic or steady tonic activity, and the increases scale flexibly with the distance and size of the rewards.

After previously discovering that the ion channel TRPA1 is used as an internal temperature sensor in Drosophila to control the slow response of flies to shallow thermal gradients, the authors show here that the rapid response of flies to steep warming gradients relies on a different protein, GR28B, providing the first example of a thermosensory role for a gustatory receptor.

In obese and overweight individuals, diet-induced weight loss and weight-stabilization interventions improve the low microbiota gene richness and clinical phenotypes seen before intervention, but have less of an effect on inflammatory phenotypes.

A population of multipotent cardiopulmonary mesoderm progenitors (CPPs) within the posterior pole of the heart expresses Wnt2, Gli1 and Isl1; these CPPs arise from cardiac progenitors before lung development, generate the mesoderm lineages within the cardiac inflow tract and lung, and are regulated by hedgehog expression from the foregut endoderm.

Single-cell RNA sequencing and weighted gene co-expression network analysis are used to study transcriptome change in pre-implantation embryos and oocytes; this reveals a conserved genetic program between human and mouse but with different developmental specificity and timing, and conserved hub genes that may be key in pre-implantation development.

A study of prostate cancer cells reveals a transcriptional activation role for long non-coding RNAs (PRNCR1 and PCGEM1) that bind to the androgen receptor, and is also observed for the truncated androgen receptor characteristic of many aggressive prostate cancers.

In an in vitro Xenopus extract system that can undergo cell cycles, mitosis spreads through the cytoplasm in ‘trigger waves’ of Cdk1 activation, which may reflect a more general biological mechanism related to action potentials and calcium waves.

The site of collision between two chromosome replication forks can be used to reinitiate replication independent of an active origin, with potentially pathogenic effects.

Stress, long hours and low morale threaten to scar the activities and careers of US life-sciences researchers, argue Warren Holleman and Ellen R. Gritz.

Researcher looks to nature to develop innovative materials.

Researchers fear hurting their publication chances by talking to journalists.

US agency seeks grant proposals across all funding programmes.

Incoming NPA director will focus on outreach and fund-raising.

Faster than a speeding photon.