Volume 456 Issue 7223, 11 December 2008

The world is sleepwalking into a surveillance society. A European court ruling offers a timely wake-up call.

The US military's human-terrain programme needs to be brought to a swift close.

Agency tightens rules for foreign visitors.

Dispute could stymie efforts to save rare honeycreeper.

Bid to extend length of certain applications draws fire.

Canadian lab retracts work on abscisic acid.

Autonomous agency will begin operations in April.

Critics worry that push for technology transfer is moving too fast.

Emissions trading rocked as Norwegian company is left in limbo.

University touts its expertise in researching animal diseases.

Eric Hand reports on the short life and hard times of the little Mars lander that sort-of-could.

Squash them, pinch them, twist them, pull them — cells react to physical forces, finds Claire Ainsworth.

Although the credit crunch has lowered the price of food, a global recession now raises the hunger pains of the most vulnerable. The stage is set for the next international food crisis, says Joachim von Braun.

Society must respond to the growing demand for cognitive enhancement. That response must start by rejecting the idea that 'enhancement' is a dirty word, argue Henry Greely and colleagues.

Two chronicles of quantum mechanics tell a good tale but don't reflect the conflicts between the physicists who struggled to reconcile theory and fact, explains Don Howard.

Science comedian Brian Malow is a regular performer on the museum and conference circuit in the United States. He explains why he finds science funny, and how he uses comedy to gain the public's interest.

Some alcohols can't be made in a way that controls the crucial arrangement of chemical groups in the molecule. A reaction that uses common laboratory reagents offers a practical route to these compounds.

Certain microorganisms from the domain Archaea seem to be big players in the marine carbon and nitrogen cycles. A study linking their abundance in the deep sea to their likely metabolic profile refines this view.

A neat technique, applied to the brightest transiting extrasolar planet known, identifies an indisputable signature of water vapour in the planet's atmosphere. The method might be used to probe a nearby habitable world.

The brain relies on blood to supply oxygen and glucose for energy. Surprisingly, neuronal activity, acting via supporting cells called astrocytes, can increase or decrease blood flow depending on whether oxygen levels are low or high.

In situ electron microscopy observations of the extrusion of single nanocrystals from graphitic cages show that these crystals deform near their theoretical strength limits. The question is how this happens.

Prime mover in behavioural physiology and sociobiology.

Calcium signalling in glial cells couples neuronal activity to regional changes in cerebral blood flow, but the polarity of its effect on the diameter of neighbouring arterioles has remained controversial. This paper reveals that when the glycolytic state of the brain is enhanced by lower tissue oxygenation, glia-mediated vasoconstrictions convert to vasodilations.

Antigenic variation is a process by which pathogens switch surface antigen expression during infection to escape immune recognition. Giardia lamblia, a major cause of parasitic diarrhoea, is now shown to regulate antigenic variation by RNA interference.

In the Saccharomyces cerevisiae pheromone response pathway, the MAP kinase Fus3 mediates the rapid negative feedback that adjusts the dose–response of the downstream system response to match that of receptor-ligand binding. This 'dose–response alignment' improves the fidelity of information transmission. Negative feedback could be used as a general mechanism in signalling systems to align dose–responses.

Head-on collision between the replication and transcription machineries halts DNA synthesis. This work examines what happens when a replisome bumps up against an engaged RNA polymerase. The study finds that the RNA polymerase is displaced from the DNA, but the replisome and the nascent mRNA remain attached. A replication assembly factor, the β-clamp, finds the 3′ end of the mRNA and recruits the still-bound replisome, which exploits the mRNA as a primer to reinitiate DNA synthesis.

Indications of the presence of water in the atmosphere of the planet HD 189733b have recently been found in transmission spectra. This paper reports the detection of strong water absorption in a high signal-to-noise, mid-infrared emission spectrum of the planet itself. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures might alter the emission spectrum over time.

There is support for the idea that there are liquid oceans on several moons of the outer planets, with Jupiter's moon Europa having received the most attention. But it is unclear how these oceans remain liquid. This paper describes strong tidal dissipation (and heating) in the liquid oceans of such moons, and shows that a previously unconsidered tidal force due to obliquity has the right form and frequency to resonantly excite large-amplitude Rossby waves.

To realize scalable quantum information networks, it will be important to develop techniques for storage and retrieval of light at the single photon level. Quantum interfaces between light and matter have been demonstrated, but mainly with atomic gases that involve sophisticated schemes to trap the atoms. This paper demonstrates a potentially more practical approach; coherent and reversible mapping of a light field with less than one photon per pulse onto an ensemble of ∼10⁷ atoms naturally trapped in a solid state medium. The state of the light is mapped onto collective atomic excitations on an optical transition and stored for a pre-programmed time up of to one microsecond before being retrieved again.

A new method to convert secondary alcohols in their single mirror image form into tertiary alcohols has been developed. Starting from a single enantiomer of the secondary alcohol, either mirror image form of the tertiary alcohol can be made with very high levels of stereocontrol. A broad range of tertiary alcohols can now be easily made by this method with very high levels of selectivity.

Continental rifts initiate and develop through repeated episodes of faulting and magmatism, yet strain partitioning between faulting and magmatism during discrete rifting episodes remains poorly documented. It is shown that most of the strain during the July–August 2007 seismic crisis in the Natron rift, Tanzania, was released aseismically. This event provides evidence for strain accommodation by magma intrusion, in addition to slip along normal faults, during the initial stages of continental rifting, and before significant crustal thinning.

Crenarchaeota, which comprise the most abundant clade of organisms on Earth, are believed to be responsible for the majority of ammonia oxidation in terrestrial and marine environments. But recent studies have suggested that not all species are autotrophic. Using a comprehensive dataset, it is now shown that a significant proportion of marine crenarchaeota lack the genes required for ammonia oxidation, suggesting that they are heterotrophs.

How the interactions between predators and prey affect the overall dynamics of ecosystems is a central question of ecology. This paper shows that by focusing on ecologically relevant interactions, that is, smaller systems in which interactions are strong, it is possible to simulate ecosystems that favour asynchrony of predator and prey cycles, with prolonged transient dynamics, just as ecologists observe in nature.

Brain development requires the coordinated differentiation and wiring of numerous neuronal cell types based on a relatively limited set of genes. This study dissects the interplay of positive and negative gene transcription regulators, which orchestrate the coordinated synthesis of specific photosensitive pigments and axon guidance molecules in a subset of Drosophila photoreceptor neurons.

Growing neuronal processes such as axons and dendrites must reach and stop within specific target areas in the developing brain. But most cell surface molecules critical for such targeting are too broadly expressed to allow for regional specificity. It is now shown that distinct axons stop in different Cadherin-N expressing layers on the basis of when and how long they express the transcription factor sequoia.

This paper identifies CD117 as a marker of a rare adult mouse prostate stem cell population, and uses this marker in combination with others to isolate single cells that can generate a prostate upon transplantation in vivo. These prostate stem cells also exhibit long-term self-renewal.

VEGF is an important angiogenic factor that has been implicated in tumourigenesis. Two papers now show that the function of VEGF is far more complex, as VEGF can negatively regulate angiogenesis and limit tumourigenesis. This study found that VEGF can inhibit angiogenesis by impeding the function of the PDGF receptor on pericytes, leading to a loss of pericyte coverage of blood vessels. This involves the formation of heterodimers between the receptors for VEGF and PDGF.

VEGF is an important angiogenic factor that has been implicated in tumourigenesis. Two papers now show that the function of VEGF is far more complex, as VEGF can negatively regulate angiogenesis and limit tumourigenesis. In the second paper, VEGF production was deleted in myeloid cells, but not other cell types. Unexpectedly, more rapid tumour development in these mice was found at the same time as attenuated tumour vascularization and the formation of morphologically and functionally normalized blood vessels. In contrast, tumours lacking VEGF altogether grew more slowly.

As part of the response to exogenous DNA damage, the transcription of certain genes involved in cell cycle checkpoints and survival is affected; these changes help the cell to maintain its genomic integrity. There are also situations in which endogenous, physiological DNA double-strand breaks occur. This paper shows that the breaks which initiate the rearrangement of antigen receptor genes also activate a transcriptional program, but with a difference. Many of the regulated genes are involved in lymphocyte development.

Advances in imaging are allowing researchers to gain better insights into the function of tissues, cells and even individual molecules. Nathan Blow examines the latest technologies lighting the way.

Staff shortages in the US fossil-fuel industry are good news for geologists, chemists and physicists. The boom is likely to continue despite the economic downturn and the rise of renewable energy, says Emma Marris.

A long and happy life?

Search for prostate-cancer target identifies stem-cell population.

Recent revolutions in genomic technologies have led to a renewed interest in quantitative genetics. One of the main areas of study is the genetic basis of complex traits, which proved difficult to investigate until the advent of genome-wide association (GWA) studies. Findings from a wide variety of organisms — from plants to mice to humans — are now markedly improving our understanding of how genotype contributes to phenotype.