Volume 459 Issue 7243, 7 May 2009

Complacency, not overreaction, is the greatest danger posed by the flu pandemic. That's a message scientists would do well to help get across.

The United States should not try to keep its space shuttles flying beyond 2010.

Its attack on poverty and arrogance is what makes C. P. Snow's 'two cultures' lecture relevant today.

Nation's costliest science facility is unveiled.

American Chemical Society makes cutbacks to fight financial losses.

Manufacturer denies that common lab feed can cause some neuron cultures to fail.

Telescope to receive final servicing mission.

What do protein crystallographers dream of? The eukaryotic ribosome, the spliceosome, the nuclear-pore complex, the HIV trimer and almost any transmembrane protein, finds Ananyo Bhattacharya.

Thin films of oxygen-bearing compounds could have myriad practical applications, finds Joerg Heber, if a few problems can be overcome.

Fifty years ago today, Charles Percy Snow argued in an influential lecture that the failure of science and the humanities to converse, and the lack of scientists in positions of power, was disastrous for society. In the first of three essays marking this anniversary, Martin Kemp contends that the real enemy of understanding is not these 'Two Cultures' but specialization in all disciplines.

In the second of three essays on the 'Two Cultures', Georgina Ferry detects that today's division lies between optimists and pessimists rather than between scientific and literary intellectuals.

An edited extract fromScience and Governmentby C. P. Snow, with an introduction by Joanne Baker.

Fossils of tiny ancient humans, found on the island of Flores, have provoked much debate and speculation. Evidence that they are a real species comes from analyses of the foot and also — more surprisingly — of dwarf hippos.

A combined millimetre- and visible-light view of a forming cluster of galaxies in the young Universe adds yet another piece to the puzzle of how today's Universe of galaxies formed and evolved.

Translation of messenger RNA into protein is a complex and intricate process involving several steps and many step-specific protein factors. But one factor — eIF5A — seems to have a hand in every step.

The latest polymers are chameleon-like: they change colour on deformation. The transduction mechanism underpinning this effect could be used to make polymers that respond in many other ways to mechanical stress.

Impaired assembly of cells' protein-synthesis factories, the ribosomes, can cause cell-cycle arrest and disease. This finding emphasizes the close link between cell proliferation and ribosome formation.

The remaining frontier in understanding the early Universe is the formation of the first stars, galaxies and massive black holes. The interplay of theory and upcoming observations promises to answer key open questions in this emerging field.

Histone acetylation has been implicated in learning and memory. Neuron-specific overexpression of histone deacetylase 2 (HDAC2), but not HDAC1, is shown to decrease memory formation in a rodent model. This encourages development and testing of HDAC2-selective inhibitors for human diseases associated with memory impairment.

Young, star-forming galaxies can be characterized by their strong Lyman-α emission. An overdensity of such a population in one region of the sky is believed to mark a forming proto-cluster. An enhancement of submillimetre galaxies near the core of this proto-cluster, and a large-scale correlation between the submillimetre galaxies and the low-mass Lyman-a emitters suggests synchronous formation of the two different types of star-forming galaxies.

The recent discovery of superconductivity in oxypnictides with the critical transition temperature (T_C) higher than 39 K has generated great interest in the underlying mechanism. The effects of oxygen and iron isotope substitution on the critical and spin-density wave transition temperatures indicate that electron–phonon interaction plays some role in the superconducting mechanism, but a simple electron–phonon coupling mechanism seems unlikely because a strong magnon–phonon coupling is included.

Exposing synthetic materials to large stresses tends to result in simple failure, unlike many biological systems, which respond by enabling physiological processes such as hearing and balance. But by incorporating a chemical group that responds to mechanical stress by changing its colour, it is possible to monitor the accumulation of plastic deformation directly in a synthetic polymer. This principle could be used to design synthetic materials with desirable functionalities ranging from damage sensing to fully regenerative self-healing.

By exploiting the unique structural motifs and self-recognition properties of DNA, it is possible to generate self-assembled DNA nanostructures of specific shapes. Here, a previously described DNA 'origami' method has been extended into three dimensions to create an addressable DNA box on the nanometre scale that can be opened by an externally supplied DNA key'.

Carbonatite lavas are unusual because they contain over 50%carbonate minerals and almost no silicate. Volcanic gases captured from Oldoinyo Lengai in northern Tanzania, which is the only currently active volcano to produce such lavas, are shown to be indistinguishable from those emitted along mid-ocean ridges. Oldoinyo Lengai is far removed from oceanic spreading centres, so this suggests that a globally homogeneous reservoir exists in the upper mantle and supplies volatiles to both mid-ocean ridges and continental rifts.

The 'hobbit', Homo floresiensis, was a species of diminutive hominin that lived on the island of Flores in Indonesia until around 14,000 years ago. Analysis of the legs and feet of the partial skeleton of the type specimen (LB1) shows some ape-like features which suggest an origin not from Homo erectus but rather some other, more primitive, hominin whose dispersal into southeast Asia is still undocumented.

Body size reduction in mammals is accompanied by only a moderate reduction in brain size, so that the brains of dwarfs are proportionately larger than those of giants. Here, the brains of extinct dwarf hippos from the island of Madagascar are shown to be disproportionately very much smaller than those of their closest mainland relatives. If this trend no longer holds true on islands, it may explain the exceptionally small brain size of the diminutive hominin, Homo floresiensis.

The ability of sensory neurons to predict an animal's upcoming decision has generated enormous interest over the last 10 years, with the proposal being that the activity of these neurons causes the appropriate decision to be made. Measuring neuronal tuning curves and perceptual decisions in a visual discrimination task in macaque monkeys, decision making was found to change the responses in sensory neurons in a 'top-down' manner, consistent with the effects of attention, thus indicating that this model is too simplistic.

Synaptic transmission is believed to function through the fusion of one synaptic vesicle with the plasma membrane at a time, but here the fusion of synaptic vesicles with themselves before release of giant vesicles at a central synapse is described.

Hedgehog signalling is important in development and disease; Fused is required for Hedgehog signalling in Drosophila but not in mice. Here it is shown how the function of Fused has evolved by studying its role in zebrafish relative to mice, providing insight into the evolution of the Hedgehog signalling cascade.

The guanine-nucleotide-binding protein stimulatory α subunit (Gα_s) is necessary for the homing and engraftment of haematopoietic stem and progenitor cells to bone marrow, as demonstrated by its disruption in adult mice deficient in Gα_s. Conversely, pharmacological activators of Gα_s enhance homing and engraftment in vivo, suggesting a potential pharmacological target to improve transplantation efficiency.

By generating maps of histone modifications at promoters and enhancers in several different human cell lines, it has been possible to determine that although modification patterns at promoters are largely invariant between cell types, the patterns at most enhancers are specific to a single cell type and correlate well with cell-type-specific gene expression.

Acetylation within the globular core domain of histone H3 on lysine 56 (H3K56) has been shown to have a critical role in packaging DNA into chromatin during DNA replication and repair in budding yeast, but has not been studied in multicellular eukaryotes. Here, the identification of multiple proteins regulating the levels of H3K56 acetylation in Drosophila and human cells allows future studies of this critical histone modulation which is implicated in cancer.

Various factors associate with the ribosome to assist in initiation, elongation and termination of translation. Only two universal factors for elongation have previously been identified; here, a factor previously thought to be associated with the initiation process, eIF5A, and which contains a rare amino acid, hypusine, is found to have a central role in elongation.

Workforce shortages could slow the growth of an industry poised for a comeback. Quirin Schiermeier reports.

Escape from your cells.