Volume 470 Issue 7335, 24 February 2011

A critical report has fuelled arguments about the benefits of energy efficiency.

Scientists should push for fair treatment of Turkish academics arrested on little evidence.

Some effects diminish when tests are repeated. Jonathan Schooler says being open about findings that don't make the scientific record could reveal why.

The week in science.

Effects of sanctions and computer worm on uranium production are disputed.

Ambitious European project hopes to navigate uncertain funding future.

Allegations over research results highlight the difficulties of investigating high-ranking administrators.

Maintaining innovative culture will be a key challenge for new owners of industry stalwart.

Large networks of researchers and companies aim to develop and commercialize marketable products.

Joe Aldy, former adviser to Barack Obama for energy and environment, assesses the state of US climate legislation.

Nearly one-quarter of biologists say they have been affected by animal activists. A Nature poll looks at the impact.

Researcher by day and activist by night, Joseph Harris was leading an untenable double life that eventually landed him in prison.

Two views on whether scientists who believe that animal experimentation is necessary should become public advocates, or work quietly behind the scenes.

Wolfgang Lucht sees a lesson for humanity's future in the long co-evolution of our planet and its inhabitants.

Mechanical world views were replaced by more sensory beliefs after the rise of the novel, finds George Rousseau.

A Philadelphia exhibition is a playful celebration of the periodic table, reports Katharine Sanderson.

Roman Kaiser, a chemist at the Givaudan Research Centre in Dübendorf, Switzerland, has recreated the scents of hundreds of rare and endangered plants in his laboratory, some of which he describes in his latest book. Here he explains how he preserves the smell of disappearing flora.

Why do some people develop post-traumatic stress disorder, but others emerge from a horrific event relatively unscathed? A molecule involved in orchestrating the brain's response to stress may hold the key to this difference. See Article p.492

Unpaired electrons can exert effects that allow interatomic contacts in molecules to be detected more easily using nuclear magnetic resonance. One such effect reveals unusual interactions between certain atoms in a protein.

Prions are infectious proteins that can cause deadly diseases in mammals. Detailed measurements of infectivity suggest that there may be distinct infectious and toxic versions of this protein. See Letter p.540

A new model for volcanic tremor has a magma column, surrounded by gas bubbles, oscillating or 'wagging' back and forth. The model reconciles several observations of this characteristic signal. See Letter p.522

Watson–Crick base pairs underpin the DNA double helix. Evidence of transient changes in base-pairing geometry highlights the fact that the information held in DNA's linear sequence is stored in three dimensions. See Article p.498

A long climate record reveals abrupt hydrological variations during past interglacials in southwestern North America. These data set a natural benchmark for detecting human effects on regional climates. See Letter p.518

A long-standing controversy about whether the motions within a typical astrophysical disk of gas are stable or unstable has resurfaced. The answer has profound significance for our understanding of how stars and planets form.

In 2–3% of cancers, a single genetic event may have led to hundreds of genomic rearrangements confined to just one or a few chromosomes. This finding challenges the conventional view of how mutations accumulate in oncogenesis.

Impressive progress has been achieved in isolating quantum systems from the environment and coherently controlling their dynamics. However, engineering the dynamics of many particles by a controlled coupling to an environment (in an 'open' quantum system) remains largely unexplored. Here, an approach is demonstrated based on ion-trap technology for simulating an open quantum system with up to five qubits. By adding controlled dissipation to coherent operations, the work offers novel prospects for open-system quantum simulation and computation.

The standard view of the genome is that the two DNA strands are linked by Watson–Crick base pairing. Some deviations from this canonical pairing have been observed when DNA is bound to a ligand. This paper now shows that naked DNA itself can transiently adopt a Hoogsteen base-pairing arrangement. This excited state base pairing provides a means to expand the chemistry and structure of DNA, and has implications for the binding of proteins to and repair of DNA.

Embryonic stem cells are typically driven to adopt a neural fate in response to inductive signals originating from the environment. However, little is known regarding the downstream molecular mechanisms operating intracellularly to induce this transformation and differentiation. Here, the zinc-finger nuclear protein Zfp521 is demonstrated to be necessary and sufficient to force a neural fate, providing evidence for a cell-intrinsic factor important in transitioning multipotent ES cells to a neural fate.

The extragalactic background light at far-infrared wavelengths comes from optically faint, dusty, star-forming galaxies with star formation rates at the level of a few hundred solar masses per year. These faint submillimetre galaxies are challenging to study individually, but their average properties can be studied using statistics such as the angular power spectrum of the background intensity variations. This study reports excess clustering over the linear prediction at arcminute angular scales in the power spectrum of brightness fluctuations at 250, 350 and 500 micrometres. It is found that submillimetre galaxies are located in dark matter haloes with a minimum mass of log₁₀[M_min/solar mass]=11.5^+0.7_-0.2 at 350° micrometres.

In geometrically frustrated materials there is an intrinsic incompatibility between fundamental interaction rules and the underlying lattice geometry, which leads to exotic material behaviour. So far, geometric frustration has been reported for a range of magnetic materials but not yet in ferroelectrics, which would be of significant fundamental interest. This study reports computational results that show that geometric frustration can be induced in ferroelectrics with compositional grading. The findings reveal unusual ordered phases, allowing new microscopic insights in the phenomenon of geometric frustration.

Droughts of tens of years are known to have occurred in the southwestern United States over the past two millennia, but model simulations suggest that much longer 'megadroughts' might occur in a future, warmer climate. So far, the presence of such droughts in the palaeoclimatic record has been unclear. Now, a lake sediment core from northern New Mexico is analysed, showing that millennial-scale megadroughts were a regular feature of Pleistocene interglacials. The results suggest that, in the absence of anthropogenic warming, the southwestern United States would probably be entering a cool and wet phase.

Most models for volcanic tremor rely on specific properties of the geometry, structure and constitution of volcanic conduits as well as the gas content of the erupting magma. Here, a model is used of a silicic magma rising in a conduit as a columnar plug to demonstrate that, for most geologically relevant conditions, the magma column will oscillate or 'wag' against the restoring force of a highly vesicular annulus of sheared bubbles at observed tremor frequencies. The frequencies produced are relatively insensitive to the conduit structure and geometry.

The 'Cambrian explosion', just over 500 million years ago, was a burst of evolution during which most kinds of animals we see today first appeared in the fossil record. They were, however, accompanied by a large number of creatures whose lineages were destined to disappear. Among these were the lobopodians, creatures vaguely related to modern arthropods and the velvet worms of tropical forests, and which — like velvet worms — looked more like worms with legs. Lobopodians came in a variety of bizarre forms, and the discovery of a lobopodian from the Cambrian of China adds to this group. It looked like a thin, flexible worm with oddly inappropriate, chunky, armoured legs. It is claimed that this creature was, however, the closest known fossil relative of modern arthropods, suggesting that the process of acquiring the robust external skeleton characteristic of the group started with the legs, and worked upwards from there.

It has recently been shown that neurons in the lateral habenula (LHb), a nucleus that projects to midbrain reward areas, can signal aversive outcomes and may be disrupted in depressive disorders. This study now shows that in rats exhibiting learned helplessness (a model of major depression) excitatory synapses onto LHb neurons are potentiated, and that this correlates with helplessness behaviour. Furthermore, depleting transmitter release by repeated electrical stimulation of LHb using a protocol similar to deep brain stimulation rescues both synaptic changes and learned helplessness behaviour.

Here it is shown that during the silent phase of prion infection, prions first exponentially propagate until a defined limit is reached. Then a plateau phase follows. Prion propagation is independent of prion concentration, whereas in the plateau phase the time to clinical onset is inversely correlated to prion concentration. The similar levels of infectivity at the end of the first and second phase suggests that there is a separation between prion infectivity and toxicity. Moreover, something seems to limit prion production. It is suggested that the prions are not neurotoxic themselves but catalyse the formation of such species from PrP^C. Production of neurotoxic species is triggered when prion propagation saturates, leading to a switch from autocatalytic production of infectivity to a toxic pathway.

Here it is shown that nanoparticles containing two Toll-like receptor ligands can boost the magnitude and persistence of vaccine-elicited antibody responses in primates, improving vaccine-mediated protection against influenza virus.

In a mouse model of Erbb2-driven mammary tumours, this study finds a role for RANKL in the formation of lung metastases. RANKL is produced by regulatory T cells infiltrating the primary tumours and acts via its receptor RANK expressed on the cancer cells. Targeting RANKL may therefore prove useful in reducing breast cancer metastases.

As the rates of replication and transcription are different, the machineries that carry out these processes are bound to clash on DNA. In contrast to results from head-on collisions, co-directional encounters have been shown to have mild effects in vitro, requiring no additional replication restart factors. It is now shown that in bacterial cells, both types of events require the activities of restart proteins to resume replication when a transcription complex is encountered.

Gram-negative bacteria expel toxic chemicals via tripartite efflux pumps spanning both the inner and outer membranes. A crystallographic model of this tripartite efflux complex has been unavailable because co-crystallization of different components of the system has proven to be extremely difficult. The X-ray crystal structure of CusA of the CusCBA tripartite efflux system from Escherichia coli has been reported previously, and here the X-ray crystal structure of the CusBA co-complex is reported. The structure reveals that the trimeric CusA efflux pump interacts with six CusB protein molecules at the upper half of the periplasmic domain, and the predicted structure of the trimeric CusC channel was used to develop a model of for the tripartite efflux complex.

Changing labs is crucial for the next generation of European scientists. But mobility can be a mixed blessing.

Lars H. Breimer, Michael E. Breimer and Douwe D. Breimer say doing a postdoc abroad is unnecessary.

Government programme helped biotechnology companies create and save jobs.

US president's budget includes a boost for postdocs.

Californian research centre starts recruiting.

A whisper in the dark.