Volume 452 Issue 7186, 27 March 2008

Science coverage is on the wane when public scrutiny of science is more important than ever.

Stem-cell research is in danger of falling foul of haste.

Researchers fear job cuts.

Dimensions of space-time used to order potential universes.

Scribbles on the margins of science.

As many amphibians face the very real threat of being completely wiped out by disease, climate change and pollution, Emma Marris looks at a controversial approach to save some of them in glass boxes.

A geoscientist devises a way to boost computing power.

Chemists have long wanted to recreate photosynthesis in the lab — and to improve on its efficiency at converting sunlight into fuel. Katharine Sanderson reports on their latest efforts.

The 'Doomsday vault' buried in the Arctic ice will provide a backup for the world's seeds. But more needs to be done to safeguard food diversity, says Michael Hopkin.

Induced pluripotent stem cells look just like embryonic stem cells, but are easier to create and free of the heavy ethics baggage. David Cyranoski separates fact from fiction in a burgeoning field.

From prisoner-of-war to head of Europe's space agency, astrophysicist Reimar Lüst reflects on his career.

Italy's first centralized museum of plants was one of the early flowerings of the unification movement. Alison Abbott reports on an important scientific legacy.

In the fable of the tortoise and the hare, the reptilian slowcoach beats its fleet-footed rival in a race. A zinc catalyst recreates this story by giving a less reactive chemical group a turn of speed over a rival group.

Circadian activity in the brain regulates the movement of blood stem cells into and out of the bone marrow. Perhaps this process is testing the suitability of these cell 'tenants' for their new home — the remodelling bone.

Observations of intensely bright star-forming galaxies both close by and in the far Universe seem to emphasize their similarities. But look a little closer, and telling differences emerge.

Spintronics is an emerging branch of electronics that exploits electrons' spin, rather than charge. In carbon nanotubes, the coupling of this spin with electron motion could offer a desirable way to control quantum information.

To store information, the brain modulates synapses, which mediate communication between neurons. A closer look hints that subcellular changes in response to groups of synapses facilitate this process.

Decisive discoveries in bacterial genetics.

In this paper gene expression is treated as a quantitative trait in both blood and adipose tissue, and associations between specific genetic loci and body mass index are identified using a molecular network approach.

Standard approaches to identify the genetic changes that lead to disease are reversed by examination of genetic networks for perturbations that are associated with disease states, and following up candidate genes from there. This begins with three genes in mice that lead to obesity when mutated, demonstrating that complex genetic–environmental traits can be dissected with this new approach.

A newly discovered mechanism for synaptic plasticity whereby higher-order information can be stored in the forward propagation of local dendritic branch spikes is described. It is reported that coupling between branches and the soma is not static as previously thought, but that an associative form of branch plasticity allows neurons to encode the spatio-temporal correlation of inputs.

Circulating haematopoetic stem cells and their progenitors exhibit robust circadian fluctuations, peaking 5 hours after the initiation of light and reaching a nadir 5 hours after darkness. Circadian oscillations are markedly altered when mice are subjected to continuous light or to a 'jet lag' (defined as a shift of 12 h). Data also suggests that circadian, neurally driven haematopoetic stem cells release during the animal's resting period may promote regeneration of the stem cell niche, and possibly of other tissues.

Based on a detailed set of electronic transport measurements on high-quality, clean single walled carbon nanotubes, direct signatures of electron spin-orbit coupling are observed. The findings may lead to new design principles for the realization of qubits in nanotubes. Furthermore, the observed spin-orbit coupling may prove to be a valuable tool as a mechanism for all-electrical control of spins in carbon nanotubes.

Organocatalysts are useful in a wide range of useful transformations, including a carbon–carbon bond forming process known as the Mannich reaction. But these reactions always failed when the simplest possible substrate, acetaldehyde, was used. This paper has now filled this gap in the market by devising effective organocatalytic conditions for Mannich reactions with acetaldehyde, greatly expanding the chemical 'toolkit' of organic chemists.

Molybdenum and total organic carbon data from black shales is used to gain insights into the redox state of the ocean. The data suggests mild oxidative weathering of the continents before ∼2,200 Myr ago, but weathering becomes more persistent and vigorous at ∼2,150 Myr ago, 200 million years after the initial rise in atmospheric oxygen. Limited availability of molybdenum after 1,800 Myr ago may have acted as a negative nutrient feedback limiting the spatial and temporal extent of sulphidic conditions.

Near the Faroe Islands in the North Atlantic, the majority of basalt is intruded into the continent–ocean transition, rather than extruded onto the surface. This melt is intruded into the lower-crust as sills, which cross-cut the continental fabric, rather than as an 'underplate' of 100% melt, as has often been assumed.

The discovery of a human lower jaw associated with stone tools and animal bones from the Sima del Elefante in northern Spain is reported. The finds have been dated to between 1.1 and 1.2 million years using a variety of dating techniques, making the site the oldest and most accurately dated record of human occupation in Europe.

As more genetic sequence data are generated, evolutionary biology questions about inheritance and phenotypes can be examined with sophisticated analyses. This paper examines pleiotropy, or multiple effects from one genetic mutation, on the skeletal characteristics of mice. It is concluded there is no 'cost of complexity' for higher organisms.

Despite marked behavioural differences between the sexes, surprisingly few anatomic features have been observed that differentiate the male and female brain in any species. But this study unveils a sexual dimorphism in the neuronal circuit responding to a pheromone, which induces different courtship behaviours in male and female fruitflies. The single neuron tracing technique that has been developed to do so should be useful to study the nervous systems of other genetically tractable species.

A transgenic molecular marking method is used to identify a class of mouse OFF retinal ganglion cells that selectivity respond to upwards motion and have a distinctive corresponding asymmetric morphology.

One of two related studies that describe the identification of a protein which is an essential component for S-type anion channel function and is required for stomatal closure in response to a variety of physiological and stress stimuli including carbon dioxide and ozone.

One of two related studies that describe the identification of a protein which is an essential component for S-type anion channel function and is required for stomatal closure in response to a variety of physiological and stress stimuli including carbon dioxide and ozone.

The Sir2 family member SIRT6 is an NAD-dependent, histone H3 lysine 9 deacetylase enzyme that modulates telomeric chromatin and is required for stable association of WRN, the factor that is mutated in Werner Syndrome.

Vaccines are no longer 'worthy but dull'. A heady mix of funding and breakthroughs is bringing this once-quiet area to life, says Virginia Gewin.

Never work with children or animals.

Getting acetaldehyde to behave as a substrate for organic synthesis.