Volume 465 Issue 7296, 20 May 2010

The United States should protect investments used to find new uses for old drugs.

Reforms that could harmonize and enhance European research deserve support.

The week in science.

Nature reports from the research ship Pelican as scientists map the hidden extent of the Deepwater disaster.

New launch vehicle could carry next generation of NASA's research probes.

Initiative seeks billions of dollars to develop promising drugs and vaccines.

Huge conservation deal will benefit caribou and maybe climate.

Studies suggest that strategies to combat the disease are offsetting the impact of climate change.

Researchers warn that confidence in stock's health could be misplaced.

Studying primates is the only way to understand human cognition — or so neuroscientists thought. But there may be much to learn from rats and mice, finds Alison Abbott.

When a submarine volcano erupts, the results can be devastating — and fascinating. Jane Qiu finds new drama in underwater biogeography.

An oil slick will not re-engage the public with environmental issues, warns Colin Macilwain, but it might lead to a saner US energy policy.

An advisory group and a network of international labs is needed to lay the groundwork for multilateral disarmament and forge links between nations, say Martin Rees, Ben Koppelman and Neil Davison.

Two years ago Raphael D. Sagarin and colleagues proposed that security systems should learn from nature. Now they've worked with defence professionals on putting that call into practice.

Michael Shermer enjoys two books that examine economics and politics from a scientific perspective — one explaining the experimental basis for democracy, another placing trade in an evolutionary context.

The latest collaborative artwork from neuroscientist Morten Kringelbach and artist Annie Cattrell reveals — and revels in — sensory dialogues in the brain, explains Martin Kemp.

Emerging resistance to existing antimalarial drugs could nullify efforts to eliminate this deadly disease. The discovery of thousands of agents active against malaria parasites offers hope for developing new drugs.

Spiders' webs are coated with microscopic droplets of glue, but the properties of this adhesive were unclear. It has now been found that the glue's stretchiness underpins its role in catching flies.

In plant roots, patterning of two types of water-conducting xylem tissue is determined by a signalling system that involves the reciprocal dance of a mobile transcription factor and mobile microRNAs.

The finding that some gas-giant exoplanets are much larger than theory predicts has been boggling astronomers' minds. Planetary heating caused by gravitational tidal interactions might be a piece of the puzzle.

Many decisions affect the fate of damaged DNA — for example, how to repair the damage, or whether to repair it at all and instead let the damaged cell die. An intricate web of molecular interactions affects such decisions.

Examples of stellar explosions have emerged that fall outside the traditional types of supernova. The nature of the stars that produce them and the mechanism by which they explode is far from clear.

A reappraisal of the messy data on upper-ocean heat content for 1993–2008 provides clear evidence for warming. But differences among various analyses and inconsistencies with other indicators merit attention.

Here, nearly 2 million compounds from GlaxoSmithKline's chemical library were screened for inhibitors of the malaria parasite Plasmodium falciparum, grown in red blood cells. Of these compounds, some 13,500 inhibited parasite growth, and more than 8,000 also showed potent activity against a multidrug resistant strain. The targets of these compounds were inferred through bioinformatic analysis, revealing several new mechanisms of antimalarial action.

Here, a library of more than 300,000 chemicals was screened for activity against Plasmodium falciparum growing in red blood cells. Of these chemicals, 172 representative candidates were profiled in detail; one exemplar compound showed efficacy in a mouse model of malaria. The findings provide the scientific community with new starting points for drug discovery.

A fundamental question in developmental biology is how cells communicate positional information to pattern the tissues of an organ. Here, the patterning of a plant's xylem tubes, which transport water and solutes from root to shoot, is studied. A new bidirectional signalling pathway is discovered, whereby a transcription factor moves from cell to cell in one direction, and microRNAs move in the other direction. The result is a differential distribution of target mRNA in the vascular cylinder, determining xylem cell types.

Supernovae are thought to arise through one of two processes. Type Ib/c and type II supernovae are produced when the cores of massive, short-lived stars undergo gravitational core collapse and eject a few solar masses. Type Ia supernovae are thought to form by the thermonuclear detonation of a carbon-oxygen white dwarf. Here a faint type Ib supernova, SN 2005E, is reported that seems not to have had a core-collapse origin, but perhaps arose from a low-mass, old progenitor, probably a helium-accreting white dwarf in a binary.

The unusual supernova SN 2005E is distinguished from any supernovae hitherto observed by several features, which are claimed to be explained by a helium detonation in a thin surface layer of an accreting white dwarf. The observed properties of SN 2005cz are now shown to resemble those of SN 2005E. It is argued that these properties are best explained by a core-collapse supernova at the low-mass end of the range of massive stars that explode.

Although compound semiconductors like gallium arsenide (GaAs) offer advantages over silicon for photovoltaic and optoelectronic applications, these do not outweigh the costly process of growing large layers of these materials and transferring them to appropriate substrates. However, a new fabrication approach is now demonstrated: films of GaAs and AlGaAs are grown in thick, multilayered assemblies in a single sequence; the individual layers are then released and distributed over foreign substrates by printing.

The upper 300 m of the world's oceans act as a giant heat sink and have absorbed the majority of the excess energy generated by anthropogenic greenhouse gases. But the magnitude of the oceanic heat uptake is uncertain, and differing estimates have led to questions regarding the closure of the global energy budget. Here, a comparison of ocean heat content estimates is presented; the conclusion is that a robust warming of 0.64 W m⁻² occurred from 1993 to 2008.

The direction of tectonic plate motion at the Earth's surface and the flow field of the mantle inferred from seismic anisotropy are well correlated globally, implying large-scale coupling between the mantle and surface plates. But the fit is poor at subduction zones. Here, three-dimensional numerical models of buoyancy-driven deformation for the Alaska subduction–transform system are used to find the origin of the regional decoupling of flow. The results imply local rapid transport of geochemical signatures through subduction zones.

Rising global temperatures resulting from climate change have been predicted to increase the future incidence of infectious diseases, including malaria. However, it is known that the range of malaria has contracted through a century of economic development and disease control. This contraction has now been quantified, and compared with the predicted effects of climate on malaria incidence. It is suggested that the impact of rising temperature is likely to be minor.

'Elite controllers' are rare people who are infected with HIV but maintain low levels of HIV RNA without being treated, making it unlikely that they will develop AIDS. Certain HLA class I alleles, notably HLA-B57, are enriched in elite controllers. Here a model is proposed to explain how such elite controllers generate an effective immune response against HIV. In this model, HLA-B57 binds to fewer self-peptides, resulting in a T-cell repertoire with enhanced cross-reactivity and leading to a more effective T-cell response to the virus.

The bacterium Shigella flexneri, which causes dysentery, infects the gastrointestinal tract. It uses a type III secretion system as a molecular syringe to inject virulence factors into host cells during infection. It is now suggested that varying oxygen availability during different phases of infection tightly regulates expression of the secretion system, as well as the secretion of virulence factors.

Toxoplasma gondii is an opportunistic human pathogen that secretes organelles called micronemes during infection. This is important for parasite motility, host-cell invasion and egress. It is now shown that the secretion of micronemes is dependent on the T. gondii calcium-dependent protein kinase 1. This kinase is not found in the parasite's mammalian hosts, and might represent a valid drug target.

The topologies of, and spatial relationships between, chromosomes are important but poorly understood. Here, a high-throughput method is used to study intra- and inter-chromosomal interactions in Saccharomyces cerevisiae. A map of the haploid genome is generated at kilobase resolution, and is used to construct a three-dimensional model of the yeast genome. The findings provide a glimpse of the interface between the form and function of a eukaryotic genome.

Calcineurin inhibitors are the mainstay of immunosuppressive treatment for organ transplant recipients. However, treatment with these drugs commonly leads to squamous cell carcinoma (SCC) of the skin. It is shown here that an intact calcineurin/NFAT signalling pathway is important for suppressing SCC development. Inhibition of this pathway leads to increased expression of the ATF3 protein, which has a key role in tumorigenesis.

Eukaryotic cells crawl through a process in which the front of the cell is propelled forwards by the force provided by polymerization of actin filaments. These must be disassembled at the rear of the cell to allow sustained motility. It is now shown that non-muscle myosin II protein is needed for the disassembly of actin networks at the rear of crawling cells.

The initiation of protein synthesis requires the eukaryotic translation initiation factor (eIF) 2, which uses energy from the hydrolysis of GTP. Another factor, eIF5, accelerates the GTP-hydrolysing activity of eIF2. Here, two other roles for eIF5 have been defined. One involves stabilizing GDP, the product of GTP hydrolysis, on eIF2. In its other role, eIF5 works with phosphorylated eIF2 to inhibit the guanine-nucleotide exchange factor eIF2B. These results clarify our understanding of how the initiation of translation is regulated.

Chang-Hwan Choi, a nanoengineer at the Stevens Institute of Technology in Hoboken, New Jersey, received a 2010 Young Investigator Program award from the US Office of Naval Research (ONR) for his design of anti-corrosion surfaces that will make Navy vessels more durable.

Streamlined grants get rolled out.

Hispanic and Native American scientists take action over immigration law.

Job security proves a worry, although flexibility is welcome.

Working with nature's nastiest microbes offers a chance to help ensure public safety. Karen Kaplan details the profession's risks and rewards.

Fighting the good fight.