Volume 454 Issue 7205, 7 August 2008

The Italian government needs to maintain a careful distance from industry.

Study probes geriatric gene pool.

Map of planet shows its age.

Evidence of illness enhances case for life.

An impasse over the budget and the impending presidential election mean that US science spending will likely be frozen for months, David Goldston reports.

Questions raised about the use of 'ALS mice' are prompting a broad reappraisal of the way that drugs are tested in animal models of neurodegenerative disease. Jim Schnabel reports.

Harvard is embarking on an experiment to foster collaboration and interdisciplinary research. Corie Lok looks at whether it can change its culture and reinvent communities along the way.

The processes used to charge athletes with cheating are often based on flawed statistics and flawed logic, says Donald A. Berry.

A perceptive history documents the many remarkable people who envisioned, built and launched the Hubble Space Telescope, explains Robert A. Brown.

The novel Hothouse is Brian Aldiss's extraordinary 1962 vision of rampant global warming, set on a future stationary Earth with one side permanently baked by the Sun. As the book is republished as a Penguin Modern Classic, the 83-year-old author shares his thoughts on science fiction and life with Nature.

Alison Abbott finds that human dissections during the Renaissance were rather respectable after all.

Earth's rocky mantle and solid inner core are separated by the 2,300-kilometre-deep layer of molten iron that constitutes the outer core. Yet the sluggish pattern of mantle convection creates structure in the inner core.

Mycobacterium tuberculosis modulates its virulence to cause persistent but often subclinical infection. This strategy is regulated in part by a feedback loop that controls the secretion of a small subset of bacterial proteins.

The ability to fabricate silicon optoelectronic devices on a curved surface will lead to imaging systems with exceptional characteristics. This innovative technology will find diverse applications.

Boy scouts recognize that the key to success is to be prepared. The same is true of molecules that bind to and open ion channels — the least effective ones are slower to prepare the channel to be ready for opening.

Light-induced reactions enable three-dimensional objects to be built from simple compounds. Proteins have been added to the list of building blocks, and the resulting gels move in response to environmental cues.

Many genetic mutations and several environmental factors contribute to Alzheimer's disease. Yet another disease risk gene, one that is involved in calcium regulation, has been added to the mix.

Modified diamond nanowires produce an electrical response on binding to DNA. This gem of a discovery could pave the way to robust biosensors that use electrical signals to detect molecules.

A mother's instinct is to protect her children at any cost. In the budding yeast Saccharomyces cerevisiae this 'maternal instinct' comes at a high price — accelerated ageing and premature death.

A plan to 'genomicize' epigenomics research and pave the way for breakthroughs in the prevention, diagnosis and treatment of human disease.

Mycobacterium tuberculosis virulence is dependent on the secretion system ESX-1. A newly discovered regulator protein termed EspR is described, which positively regulates ESX-1 and is secreted itself, thereby providing a negative feedback regulatory mechanism.

Ligand-gated ion channels can be opened by both full and partial agonists, though in the case of a partial agonist, the maximum response is only a fraction of that evoked by a full agonist. The mechanism underlying this pharmacological observation is investigated and it is shown that cys-loop receptors bound to partial agonists are as efficient at opening as those that are bound to full agonists. Instead, the diminished response results from a reduced ability to adopt an intermediate (agonist bound but pre-open) state.

In budding yeast ageing factors are retained in the mother cell, ensuring that the newly formed bud remains young. It is shown that a septin-dependent barrier forms in the nuclear envelope, which prevents pre-existing nuclear pores and other ageing factors from moving into the newly formed bud. These results demonstrate the importance of the nuclear envelope in ageing in yeast cells.

In cold dark matter cosmological models, structures form and grow by merging of smaller units, previous simulations have shown that such merging is incomplete as the inner cores of halos survive and orbit as 'subhalos' within their hosts. This paper reports a simulation that resolves such substructure in the very inner regions of the Galactic halo. Hundreds of very concentrated dark matter clumps survive near the solar circle, as well as numerous cold streams.

Microscopic properties of fermion pairs can be probed with radio-frequency spectroscopy. But previous work was difficult to interpret due to strong final-state interactions, which were not well understood. A superfluid spin mixture in an ultracold atomic gas in which such interactions have negligible influence is realized, and it is found that the spectroscopic pair size is smaller than the inter-particle spacing. These are the smallest pairs yet observed for fermionic superfluids.

Recent experiments using ultracold Fermi gases have demonstrated a phase transition to a superfluid state with strong inter-particle interactions, but these interactions make it difficult to study the behaviour of the atoms in the gas. A technique called photoemission spectroscopy is used to enable a study of the pairing between the atoms. This is of interest because the physics is related to that of the high transition-temperature superconductors.

This paper reports on an electronic eye-like camera based on single-crystal silicon that makes use of two ingenious fabrication steps; first, optoelectronic circuits at waver-scale in unusual, two-dimensionally compressible configurations are constructed and second, suitable elastomeric elements to transfer these planar layouts into hemispherical geometries are designed. It is expected that the strategy provides practical routes for integrating well planar device technologies onto the surfaces of complex curvilinear objects.

Geochronological data on hotspot volcanoes in eastern Australia are presented, which reveal a strong link between collision of the plateau with the Melanesian arc and motion of the Australian plate. The timing and brevity of this collisional event correlate well with offsets in hotspot seamount tracks in the Pacific, including the archetypal Hawaiian chain, and thus provide strong evidence that immense oceanic plateaus can contribute to initiating rapid change in plate boundaries and motions on a global scale.

Seismic waves sampling the top 100 km of the Earth's inner core have revealed that the eastern hemisphere is seismically faster, more isotropic and more attenuating than the western hemisphere. It is now shown that a single model of thermo-chemical convection and dynamo action can account for all these effects by producing a large-scale, long-term outer core flow that couples the heterogeneity of the inner core with that of the lower mantle.

New genes often evolve when one gene is duplicated, and one or both of the copies evolve new functions. Many studies have explored the mechanism behind this evolution, primarily thought to be the processes of neo-functionalization and escape from adaptive conflict. This paper proposes tests to distinguish between these two processes and argues that the latter has occurred much more often than previously thought.

Genome-scale DNA methylation profiles have been generated at nucleotide resolution in mammalian cells using a combination of high-throughput bisulphite sequencing and single molecule-based sequencing. The DNA methylation maps cover the vast majority of CpG islands, as well as several other genomic regions, in murine embryonic stem cells, cells derived from ES cells and various primary cells.

This study shows that mushroom bodies in Drosophila brains also have a role in temperature preference behaviour. When cAMP-dependent kinase activity in mushroom body neurons is artificially lowered, the Drosophila cannot find their desired temperature properly. When it is increased, they prefer higher temperatures. The study adds a classic homeostatic process to the mushroom bodies' list of functions.

Herpes viruses maintain life-long latent infection. This paper provides evidence suggesting that latency is in part mediated by micro RNAs derived from the viral LAT gene, which are thought to downregulate key viral immediate early proteins.

This paper describes the use of optical microendoscopy to visualize sarcomeres and their micron-scale motions in live mice and humans, revealing unanticipated local variations in sarcomere lengths. Imaging of human sarcomeres is expected to enable advances in biomechanical modelling, orthopedic therapeutics, and the understanding and treatment of neuromuscular disorders

A crystal structure of neurotrophin-3 (NT-3) complexed to the ectodomain of a glycosylated neurotrophin receptor p75^NTR, together with biochemical experiments, reveals that NT-3 forms a central homodimer around which two p75^NTR molecules bind symmetrically, resulting in 2:2 ligand–receptor stoichiometry.

Researchers now have access to a burgeoning collection of tools for unravelling the epigenome, which could lead to new drug targets and ways to track disease. Laura Bonetta reports.

To reclaim the planet.

Flipping the switch on ion channel 'partial' activation.