Hot off the presses! Aug 06 Nature

The Aug 06 issue of the Nature is now up on Pubget (About Nature): if you're at a subscribing institution, just click the link in the latest link at the home page. (Note you'll only be able to get all the PDFs in the issue if your institution subscribes to Pubget.)

Latest Articles Include:

• A model approach
  - Nature 460(7256):667 (2009)
  More development work is needed to help computer simulations inform economic policy.
• Science under attack
  - Nature 460(7256):667 (2009)
  Congress should stop playing politics with the peer-review process.
• Evolution: Arboreal ascent
  - Nature 460(7256):668 (2009)
  
• Exoplanets: Avoiding shrinkage
  - Nature 460(7256):668 (2009)
  
• Cancer biology: HPV's unexpected effect
  - Nature 460(7256):668 (2009)
  
• Materials science: Foam finesse
  - Nature 460(7256):668 (2009)
  
• Neuroscience: Learning experience
  - Nature 460(7256):668 (2009)
  
• Genetics: Context is king
  - Nature 460(7256):668-669 (2009)
  
• Water management: Colorado be dammed
  - Nature 460(7256):669 (2009)
  
• Invertebrate immunity: Infection in real time
  - Nature 460(7256):669 (2009)
  
• Chemical biology: 800 million strong
  - Nature 460(7256):669 (2009)
  
• Structural biology: Get into the groove
  - Nature 460(7256):669 (2009)
  
• Journal club
  - Nature 460(7256):669 (2009)
  
• US joins China in climate talks
  - Nature 460(7256):460 (2009)
  The United States and China adjourned a new round of bilateral talks in Washington DC last week with the vague outline of a climate partnership. But the 'G2' is far from sealing a meaningful deal in time for the global-warming summit in Copenhagen this December.
• Greek scientists fight research shake-up
  - Nature 460(7256):671 (2009)
  Instead of enjoying a tranquil summer break, Greek researchers are fighting a major reorganization that will carve up two of the country's largest research centres. Filippos Tsalidis, head of the development ministry's office for research and technology, took the scientific community by surprise by announcing the changes, intended to promote efficiency, in the business newspaper Naftemporiki on 3 June.
• Snapshot: The guts of a dying star
  - Nature 460(7256):671 (2009)
  Swirling gas sets pulsar spinning in supercomputer simulation. This visualization of a simulated supernova is helping to reveal why pulsars spin so fast. Pulsars are neutron stars that emit beams of electromagnetic radiation as they whirl around many times per second — a rate that astrophysicists have struggled to explain. Pulsars are thought to form in core-collapse supernovae, the explosive deaths of stars at least eight times the mass of the Sun, in which the iron core collapses in on itself. In 2007, computer simulations suggested that the stars don't explode in perfectly smooth spheres (J. M. Blondin and A. Mezzacappa Nature 445, 58–60; 2007). This latest visualization, created by Hongfeng Yu, a computer scientist at Sandia National Laboratories in Livermore, California, shows the entropy of the gases in the dying star's core, revealing the immense swirling currents that originated as tiny perturbations (gases with the highest entropy are yellow, followed by green and then purple). The currents "spin up the proto-neutron star, just like pulling a string on an old spinning top", says Bronson Messer, an astrophysicist at Oak Ridge National Laboratory in Tennessee, who contributed to the research. The work incorporates a new visualization technique, developed at Argonne National Laboratory outside Chicago, Illinois, which runs and visualizes the simulation directly on a Blue Gene/P supercomputer.
• Who speaks for science in Europe?
  - Nature 460(7256):672-673 (2009)
  European scientists don't have too much to complain about these days. More than €50 billion (US$70 billion) is budgeted for research in the European Union's (EU) Seventh Framework Programme (FP7), which began in 2007 and runs until 2013.
• Spain unveils its eye on the sky
  - Nature 460(7256):674 (2009)
  As the world's largest single optical telescope officially opens for business, some astronomers are still wondering precisely what that business should be. The Gran Telescopio Canarias (GTC), which boasts a 10.
• Joint Mars plans come together
  - Nature 460(7256):675 (2009)
  US and Europe schedule rovers and orbiters for the red planet. NASA and the European Space Agency (ESA) have unveiled a joint plan for exploring Mars in the latter half of the next decade. ESA will build a trace-gas orbiter, able to map plumes of methane in the atmosphere, for launch in 2016. This could help to target landing of the agency's flagship rover, ExoMars, and a mid-sized NASA rover, due for launch in 2018. Click for larger image "These two rovers will be focused on astrobiology — seeking the signs of life," says NASA's Mars programme chief Doug McCuistion, who told the US Mars community about the plan at an advisory committee meeting on 29 July at Brown University in Providence, Rhode Island. The plan was negotiated at a NASA–ESA summit in Plymouth, UK, at the end of June, and McCuistion says that ESA member states have now agreed to it. Jack Mustard, a Brown University geologist and chair of a NASA Mars advisory group, says that the community is pleased to have a 2016 orbital mission at all after the Mars Science Laboratory (MSL), a large rover still scheduled for a 2011 launch, ran roughshod over NASA budgets with its price tag, which could end up being as high as $2.4 billion. "Scientists are definitely happy to have a viable opportunity for measurements," he says. "But it's far too new. No one knows what it means or how it's going to work out." Each agency has negotiated its share of the work. NASA will provide Atlas rockets for both launches, and in 2018 it aims to re-use the 'sky crane' technology that it is developing to lower the MSL to the planet's surface. Initially, NASA and ESA officials hoped to squeeze ExoMars and a trace-gas orbiter onto the same Atlas rocket for a 2016 launch. But ESA eventually agreed to delay ExoMars until 2018, a launch window with better orbital mechanics. ESA plans to use leftover payload on the 2016 rocket for a small lander as a way to test tricky technology for entry, descent and landing. In 2018, NASA is looking to fit another rover on board. Whereas ExoMars will drill cores as much as two metres deep to look for life, the new NASA rover — bigger than the current rovers Spirit and Opportunity, but smaller than the MSL — would analyse and cache rocks as a first step in a far-off sample-return mission. Both could be aided by the 2016 orbiter, if it were able to direct the rovers to a landing site near vents of methane, which can be produced by subterranean microbes or by hydrothermal processes on certain volcanic rocks. A paper in Nature this week (see page 720) shows that the observation of seasonal methane plumes cannot be explained by conventional models for atmospheric circulation, which should disperse the methane uniformly. The authors instead posit that seasonal plumes of methane can exist only if the gas is destroyed quickly in surface interactions with soils. ADVERTISEMENT A joint NASA–ESA science team has just begun working out the orbiter's design requirements, with instruments expected to be awarded competitively to ESA or NASA scientists. Sushil Atreya, an atmospheric scientist at the University of Michigan in Ann Arbor who has worked on ESA's Mars Express orbital mission, says he is pleased to see initial designs calling for methane sensitivities of parts per trillion. That would be orders of magnitude better than the parts-per-billion measurements of Mars Express, and could allow the detection of light carbon isotopes — a possible indicator of biological origin — within methane molecules. But mapping the methane will be much, much tougher, says Atreya. A spatial resolution of 10 or 20 kilometres would be necessary to be of any help in targeting a rover. Mars Express was only able to find hints of regional methane variability, whereas the plumes discovered by ground-based observations were discerned across hundreds of kilometres. "Have you ever tried to catch gas in the wind?" asks Mustard. "It's a moving target."
• Grant scores leave applicants in limbo
  - Nature 460(7256):676 (2009)
  Applicants for the coveted Challenge Grants issued by the US National Institutes of Health (NIH) as part of the American Recovery and Reinvestment Act learned the peer-review scores for their proposals late last month. Yet they received little in the way of certainty over whether those scores will translate into money come September, when the NIH will announce which grants it plans to fund.
• India embarks on push to become a solar power
  - Nature 460(7256):677 (2009)
  
• Lab worker charged with destroying protein crystals
  - Nature 460(7256):677 (2009)
  A former employee who allegedly destroyed US$500,000 worth of protein crystal samples at the SLAC National Accelerator Laboratory in Menlo Park, California, was arrested and charged last week with wilfully ruining government property. Silvya Oommachen, until July a research associate at SLAC's Joint Center for Structural Genomics (JCSG), removed 4,000–5,000 protein crystals from three SLAC freezers at some point between 17 and 20 July, according to an FBI affidavit. The now-useless crystals formed part of the Protein Structure Initiative, a federally funded project to expedite the discovery of atomic-level protein structures. JCSG director Ian Wilson estimates that his research team now faces a "two- to three-month setback" to remake the protein crystals that had not yet been analysed.
• Plummeting silicon prices may boost solar sales
  - Nature 460(7256):677 (2009)
  
• US report backs distinction between science and policy
  - Nature 460(7256):677 (2009)
  
• Chikyu showcases riser drilling for deep-sea research
  - Nature 460(7256):677 (2009)
  IODP/JAMSTEC The first scientific ocean-floor drilling project to use a riser drill — equipment previously used in oil exploration — was completed last week. The Japanese research vessel Chikyu (pictured) drilled 1,600 metres below the sea floor of the Nankai Trough, an earthquake-generating zone off the Pacific coast of Japan. Riser drilling circulates mud in an extra casing around the drill to prevent the collapse of a borehole in deep, high-pressure zones. Chikyu had already tested its riser-drilling equipment while on loan to an Australian oil company (see Nature 442, 964; 2006). The vessel is taking a leading role in the Integrated Ocean Drilling Program, a collaboration of Japanese, US and European scientists studying rock and sediment samples to learn about Earth's structure and history. It is due to drill two more sites in the Nankai Trough.
• Corrections
  - Nature 460(7256):677 (2009)
  The News story 'Biodefence lab criticized' (Nature 460, 556–557; 2009) conflated two different foot-and-mouth disease outbreaks in Britain. The 2001 outbreak required the slaughter of 6 million animals; a 2007 outbreak originated from the animal-research lab in Pirbright. The News story 'Flu jabs urged for developing countries' (Nature 460, 156–157; 2009) incorrectly stated that Abdullah Brooks has determined that one-third of pneumonia deaths in children younger than 2 years old in Bangladesh can be attributed to the influenza virus. In fact, he has determined that about one-third of children who get influenza develop pneumonia, of whom about two-thirds are less than two years old.
• Sending out an SOS
  - Nature 460(7256):679 (2009)
  When a public official appoints a commission to study a problem, it's usually assumed to be a craven strategy to delay a decision or to dodge responsibility. But sometimes tossing an issue over to outsiders actually offers the best chance of moving forward.
• Economics: Meltdown modelling
  - Nature 460(7256):680-682 (2009)
  It's 2016, and experts at a US government facility have detected a threat to national security. A screen on the wall maps the world's largest financial players — banks, governments and hedge funds — as well as the web of loans, ownership stakes and other legal claims that link them.
• Helping young scientists to speak for themselves
  - Nature 460(7256):683 (2009)
  As you indicate in your Editorial 'Cheerleader or watchdog?' (Nature 459, 1033; 2009
• Flu: no sign so far that the human pandemic is spread by pigs
  - Nature 460(7256):683 (2009)
  Further to your Editorial 'Animal farm: pig in the middle' (Nature 459, 889; 2009), the World Organisation for Animal Health (OIE) would like to clarify what is understood so far about how animals are associated with the human influenza A/H1N1 pandemic.
• Small but effective moves towards a greener China
  - Nature 460(7256):683-684 (2009)
  Your Editorial 'Raising the standards' (Nature 459, 1033–1034; 2009) reports on the pressure being imposed by non-governmental organizations on China's local governments to provide the public with more information about pollution.
• Mystery ape: other fossils suggest that it's no mystery at all
  - Nature 460(7256):684 (2009)
  Russell Ciochon, in his Essay 'The mystery ape of Pleistocene Asia' (Nature 459, 910–911; 2009), makes passing reference to the Late Miocene ape Lufengpithecus, which is known from Lufeng in the Chinese province of Yunnan. Ciochon then immediately discounts the significance of Lufengpithecus because "the age was wrong".
• Mystery ape: a call for taxonomic rigour
  - Nature 460(7256):684 (2009)
  The Essay by Russell Ciochon on 'The mystery ape of Pleistocene Asia' (Nature 459, 910–911; 2009) and the accompanying News story 'Early man becomes early ape' (Nature459, 899; 2009) announce that Ciochon has changed his mind about the taxonomic assignment of a 1.9-million-year-old hominoid partial jaw.
• Human uniqueness and the denial of death
  - Nature 460(7256):684 (2009)
  Marc Hauser's Horizons article 'The possibility of impossible cultures' (Nature 460, 190–196; 2009) carries an implicit assumption that cardinal aspects of human uniqueness arose by positive natural selection because they were beneficial to ancestral hominins. But this may not be the whole story.
• The economy needs agent-based modelling
  - Nature 460(7256):685-686 (2009)
  The leaders of the world are flying the economy by the seat of their pants, say J. Doyne Farmer and Duncan Foley. There is, however, a better way to help guide financial policies.
• Modelling to contain pandemics
  - Nature 460(7256):687 (2009)
  Agent-based computational models can capture irrational behaviour, complex social networks and global scale — all essential in confronting H1N1, says Joshua M. Epstein.
• In Retrospect: Lamarck's treatise at 200
  - Nature 460(7256):688-689 (2009)
  Fifty years before On the Origin of Species, a confusing, tiresome and prescient book laid the foundations of modern evolutionary theory, write Dan Graur, Manolo Gouy and David Wool.
• A passion for birds
  - Nature 460(7256):689 (2009)
  If you had less than one year left to live, how would you spend your days? After being diagnosed with terminal cancer, Phoebe Snetsinger, the subject of Olivia Gentile's first book, invested her time trying to see every bird species in the world.
• Playing the con game of academe
  - Nature 460(7256):690 (2009)
  Young scientists often aim for research-focused professorships at elite universities. Those who achieve this goal spend their lives tirelessly working towards the next great finding, hopeful of recognition from their scientific peers.
• Me, environmentalist
  - Nature 460(7256):691 (2009)
  Summer visitors to Paris might hear Tarzan's distinctive roar above the sound of traffic. The subject of an exhibition at the city's Quai Branly Museum (Musée du Quai Branly), the fictional loin-clothed hero provides possibly the most oblique take on Darwinism seen during the bicentennial year.
• Ecology reading
  - Nature 460(7256):691 (2009)
  In Notebooks from New Guinea (Oxford University Press, 2009), tropical biologist Vojtech Novotny describes vividly what it is like to work deep in the malaria-infested Papuan rainforest. Sharing his personal experiences of setting up a research station in this remote and lawless place, he reflects on the clash between the cultures of Papua New Guinea and Europe.
• Demography: Babies make a comeback
  - Nature 460(7256):693-694 (2009)
  The population of some wealthy countries is shrinking because of a declining birth rate. It comes as a surprise, and one with policy implications, that after a certain point of development that trend can reverse.
• Galaxy formation: Too small to ignore
  - Nature 460(7256):694-695 (2009)
  A study of one galaxy's dynamics backs up previous claims that surprisingly compact galaxies existed in the early Universe. But how such objects blew up in size to form present-day galaxies remains a puzzle.
• Archaeology: The earliest musical tradition
  - Nature 460(7256):695-696 (2009)
  Music is a ubiquitous element in our daily lives, and was probably just as important to our early ancestors. Fragments of ancient flutes reveal that music was well established in Europe by about 40,000 years ago.
• Structural biology: Aerial view of the HIV genome
  - Nature 460(7256):696-698 (2009)
  A bird's-eye view of the higher-order structure of HIV-1's entire RNA genome reveals new motifs in surprising places. Structural biologists can now zoom in on these regions to explore their functions further.
• 50 & 100 years ago
  - Nature 460(7256):697 (2009)
  Sir John Cockcroft is reported to have expressed the opinion on April 26 that in 1966 some 25 per cent of the requirements of the United Kingdom for electricity would be met by nuclear generation, 50 per cent by 1975 and 100 per cent by the end of the century. Questions asked in the House of Commons on June 8 indicate a disposition to allow political and social considerations to over-ride, if not distort, the technical and economic aspects, and there have been other attempts to make the effect on the coal industry the deciding factor in determining the development of nuclear power.
• Biogeochemistry: Carbonate rocks deconstructed
  - Nature 460(7256):698-699 (2009)
  The ratios of stable isotopes, especially isotopes of carbon and oxygen, have tales to tell about Earth's history. Post-depositional alteration of the carbonate rocks being studied may radically alter the story.
• Beyond the myth of the supernova-remnant origin of cosmic rays
  - Nature 460(7256):701-704 (2009)
  The origin of Galactic cosmic-ray ions has remained an enigma for almost a century. Although it has generally been thought that they are accelerated in the shock waves associated with powerful supernova explosions—for which there have been recent claims of evidence—the mystery is far from resolved. In fact, we may be on the wrong track altogether in looking for isolated regions of cosmic-ray acceleration.
• miR-145 and miR-143 regulate smooth muscle cell fate and plasticity
  - Nature 460(7256):705-710 (2009)
  MicroRNAs (miRNAs) are regulators of myriad cellular events, but evidence for a single miRNA that can efficiently differentiate multipotent stem cells into a specific lineage or regulate direct reprogramming of cells into an alternative cell fate has been elusive. Here we show that miR-145 and miR-143 are co-transcribed in multipotent murine cardiac progenitors before becoming localized to smooth muscle cells, including neural crest stem-cell-derived vascular smooth muscle cells. miR-145 and miR-143 were direct transcriptional targets of serum response factor, myocardin and Nkx2-5 (NK2 transcription factor related, locus 5) and were downregulated in injured or atherosclerotic vessels containing proliferating, less differentiated smooth muscle cells. miR-145 was necessary for myocardin-induced reprogramming of adult fibroblasts into smooth muscle cells and sufficient to induce differentiation of multipotent neural crest stem cells into vascular smooth muscle. Furthermore , miR-145 and miR-143 cooperatively targeted a network of transcription factors, including Klf4 (Kruppel-like factor 4), myocardin and Elk-1 (ELK1, member of ETS oncogene family), to promote differentiation and repress proliferation of smooth muscle cells. These findings demonstrate that miR-145 can direct the smooth muscle fate and that miR-145 and miR-143 function to regulate the quiescent versus proliferative phenotype of smooth muscle cells.
• Architecture and secondary structure of an entire HIV-1 RNA genome
  - Nature 460(7256):711-716 (2009)
  Single-stranded RNA viruses encompass broad classes of infectious agents and cause the common cold, cancer, AIDS and other serious health threats. Viral replication is regulated at many levels, including the use of conserved genomic RNA structures. Most potential regulatory elements in viral RNA genomes are uncharacterized. Here we report the structure of an entire HIV-1 genome at single nucleotide resolution using SHAPE, a high-throughput RNA analysis technology. The genome encodes protein structure at two levels. In addition to the correspondence between RNA and protein primary sequences, a correlation exists between high levels of RNA structure and sequences that encode inter-domain loops in HIV proteins. This correlation suggests that RNA structure modulates ribosome elongation to promote native protein folding. Some simple genome elements previously shown to be important, including the ribosomal gag-pol frameshift stem-loop, are components of larger RNA motifs. We also identify organizational principles for unstructured RNA regions, including splice site acceptors and hypervariable regions. These results emphasize that the HIV-1 genome and, potentially, many coding RNAs are punctuated by previously unrecognized regulatory motifs and that extensive RNA structure constitutes an important component of the genetic code.
• A high stellar velocity dispersion for a compact massive galaxy at redshift z = 2.186
  - Nature 460(7256):717-719 (2009)
  Recent studies have found that the oldest and most luminous galaxies in the early Universe are surprisingly compact1, 2, 3, 4, 5, 6, 7, having stellar masses similar to present-day elliptical galaxies but much smaller sizes. This finding has attracted considerable attention8, 9, 10, 11, 12, 13, as it suggests that massive galaxies have grown in size by a factor of about five over the past ten billion years (10 Gyr). A key test of these results is a determination of the stellar kinematics of one of the compact galaxies: if the sizes of these objects are as extreme as has been claimed, their stars are expected to have much higher velocities than those in present-day galaxies of the same mass. Here we report a measurement of the stellar velocity dispersion of a massive compact galaxy at redshift z = 2.186, corresponding to a look-back time of 10.7 Gyr. The velocity dispersion is very high at km s-1, consistent with the mass and compactness of the galaxy inferred from phot ometric data. This would indicate significant recent structural and dynamical evolution of massive galaxies over the past 10 Gyr. The uncertainty in the dispersion was determined from simulations that include the effects of noise and template mismatch. However, we cannot exclude the possibility that some subtle systematic effect may have influenced the analysis, given the low signal-to-noise ratio of our spectrum.
• Observed variations of methane on Mars unexplained by known atmospheric chemistry and physics
  - Nature 460(7256):720-723 (2009)
  The detection of methane on Mars1, 2, 3 has revived the possibility of past or extant life on this planet, despite the fact that an abiogenic origin is thought to be equally plausible4. An intriguing aspect of the recent observations of methane on Mars is that methane concentrations appear to be locally enhanced and change with the seasons3. However, methane has a photochemical lifetime of several centuries, and is therefore expected to have a spatially uniform distribution on the planet5. Here we use a global climate model of Mars with coupled chemistry6, 7, 8 to examine the implications of the recently observed variations of Martian methane for our understanding of the chemistry of methane. We find that photochemistry as currently understood does not produce measurable variations in methane concentrations, even in the case of a current, local and episodic methane release. In contrast, we find that the condensation–sublimation cycle of Mars' carbon dioxide atmosphere can generate large-scale methane variations differing from those observed. In order to reproduce local methane enhancements similar to those recently reported3, we show that an atmospheric lifetime of less than 200 days is necessary, even if a local source of methane is only active around the time of the observation itself. This implies an unidentified methane loss process that is 600 times faster than predicted by standard photochemistry. The existence of such a fast loss in the Martian atmosphere is difficult to reconcile with the observed distribution of other trace gas species. In the case of a destruction mechanism only active at the surface of Mars, destruction of methane must occur with an even shorter timescale of the order of 1 hour to explain the observations. If recent observations of spatial and temporal variations of methane are confirmed, this would suggest an extraordinarily harsh environment for the survival of organics on the planet.
• Observation of strong coupling between a micromechanical resonator and an optical cavity field
  - Nature 460(7256):724-727 (2009)
  Achieving coherent quantum control over massive mechanical resonators is a current research goal. Nano- and micromechanical devices can be coupled to a variety of systems, for example to single electrons by electrostatic1, 2 or magnetic coupling3, 4, and to photons by radiation pressure5, 6, 7, 8, 9 or optical dipole forces10, 11. So far, all such experiments have operated in a regime of weak coupling, in which reversible energy exchange between the mechanical device and its coupled partner is suppressed by fast decoherence of the individual systems to their local environments. Controlled quantum experiments are in principle not possible in such a regime, but instead require strong coupling. So far, this has been demonstrated only between microscopic quantum systems, such as atoms and photons (in the context of cavity quantum electrodynamics12) or solid state qubits and photons13, 14. Strong coupling is an essential requirement for the preparation of mechanical quantum states, such as squeezed or entangled states15, 16, 17, 18, and also for using mechanical resonators in the context of quantum information processing, for example, as quantum transducers. Here we report the observation of optomechanical normal mode splitting19, 20, which provides unambiguous evidence for strong coupling of cavity photons to a mechanical resonator. This paves the way towards full quantum optical control of nano- and micromechanical devices.
• The late Precambrian greening of the Earth
  - Nature 460(7256):728-732 (2009)
  Many aspects of the carbon cycle can be assessed from temporal changes in the 13C/12C ratio of oceanic bicarbonate. 13C/12C can temporarily rise when large amounts of 13C-depleted photosynthetic organic matter are buried at enhanced rates1, and can decrease if phytomass is rapidly oxidized2 or if low 13C is rapidly released from methane clathrates3. Assuming that variations of the marine 13C/12C ratio are directly recorded in carbonate rocks, thousands of carbon isotope analyses of late Precambrian examples have been published to correlate these otherwise undatable strata and to document perturbations to the carbon cycle just before the great expansion of metazoan life. Low 13C/12C in some Neoproterozoic carbonates is considered evidence of carbon cycle perturbations unique to the Precambrian. These include complete oxidation of all organic matter in the ocean2 and complete productivity collapse such that low-13C/12C hydrothermal CO2 becomes the main input of carbon4. H ere we compile all published oxygen and carbon isotope data for Neoproterozoic marine carbonates, and consider them in terms of processes known to alter the isotopic composition during transformation of the initial precipitate into limestone/dolostone. We show that the combined oxygen and carbon isotope systematics are identical to those of well-understood Phanerozoic examples that lithified in coastal pore fluids, receiving a large groundwater influx of photosynthetic carbon from terrestrial phytomass. Rather than being perturbations to the carbon cycle, widely reported decreases in 13C/12C in Neoproterozoic carbonates are more easily interpreted in the same way as is done for Phanerozoic examples. This influx of terrestrial carbon is not apparent in carbonates older than 850 Myr, so we infer an explosion of photosynthesizing communities on late Precambrian land surfaces. As a result, biotically enhanced weathering generated carbon-bearing soils on a large scale and their d etrital sedimentation sequestered carbon5. This facilitated a rise in O2 necessary for the expansion of multicellular life.
• Fluid and deformation regime of an advancing subduction system at Marlborough, New Zealand
  - Nature 460(7256):733-736 (2009)
  Newly forming subduction zones on Earth can provide insights into the evolution of major fault zone geometries from shallow levels to deep in the lithosphere and into the role of fluids in element transport and in promoting rock failure by several modes1, 2. The transpressional subduction regime of New Zealand, which is advancing laterally to the southwest below the Marlborough strike–slip fault system of the northern South Island3, 4, is an ideal setting in which to investigate these processes. Here we acquired a dense, high-quality transect of magnetotelluric soundings across the system, yielding an electrical resistivity cross-section to depths beyond 100 km. Our data imply three distinct processes connecting fluid generation along the upper mantle plate interface to rock deformation in the crust as the subduction zone develops. Massive fluid release just inland of the trench induces fault-fracture meshes through the crust above that undoubtedly weaken it as region al shear initiates. Narrow strike–slip faults in the shallow brittle regime of interior Marlborough diffuse in width upon entering the deeper ductile domain aided by fluids and do not project as narrow deformation zones. Deep subduction-generated fluids rise from 100 km or more and invade upper crustal seismogenic zones that have exhibited historic great earthquakes on high-angle thrusts that are poorly oriented for failure under dry conditions. The fluid-deformation connections described in our work emphasize the need to include metamorphic and fluid transport processes in geodynamic models.
• New flutes document the earliest musical tradition in southwestern Germany
  - Nature 460(7256):737-740 (2009)
  Considerable debate surrounds claims for early evidence of music in the archaeological record1, 2, 3, 4, 5. Researchers universally accept the existence of complex musical instruments as an indication of fully modern behaviour and advanced symbolic communication1 but, owing to the scarcity of finds, the archaeological record of the evolution and spread of music remains incomplete. Although arguments have been made for Neanderthal musical traditions and the presence of musical instruments in Middle Palaeolithic assemblages, concrete evidence to support these claims is lacking1, 2, 3, 4. Here we report the discovery of bone and ivory flutes from the early Aurignacian period of southwestern Germany. These finds demonstrate the presence of a well-established musical tradition at the time when modern humans colonized Europe, more than 35,000 calendar years ago. Other than the caves of the Swabian Jura, the earliest secure archaeological evidence for music comes from sites in France and Austria and post-date 30,000 years ago6, 7, 8.
• Advances in development reverse fertility declines
  - Nature 460(7256):741-743 (2009)
  During the twentieth century, the global population has gone through unprecedented increases in economic and social development that coincided with substantial declines in human fertility and population growth rates1, 2. The negative association of fertility with economic and social development has therefore become one of the most solidly established and generally accepted empirical regularities in the social sciences1, 2, 3. As a result of this close connection between development and fertility decline, more than half of the global population now lives in regions with below-replacement fertility (less than 2.1 children per woman)4. In many highly developed countries, the trend towards low fertility has also been deemed irreversible5, 6, 7, 8, 9. Rapid population ageing, and in some cases the prospect of significant population decline, have therefore become a central socioeconomic concern and policy challenge10. Here we show, using new cross-sectional and longitudinal a nalyses of the total fertility rate and the human development index (HDI), a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century. Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development–fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries. This reversal of fertility decline as a result of continued economic and social development has the potential to slow the rates of population ageing, thereby ameliorating the social and economic problems that have been associated with the emergence and persistence of very low fertility.
• Common variants conferring risk of schizophrenia
  - Nature 460(7256):744-747 (2009)
  Schizophrenia is a complex disorder, caused by both genetic and environmental factors and their interactions. Research on pathogenesis has traditionally focused on neurotransmitter systems in the brain, particularly those involving dopamine. Schizophrenia has been considered a separate disease for over a century, but in the absence of clear biological markers, diagnosis has historically been based on signs and symptoms. A fundamental message emerging from genome-wide association studies of copy number variations (CNVs) associated with the disease is that its genetic basis does not necessarily conform to classical nosological disease boundaries. Certain CNVs confer not only high relative risk of schizophrenia but also of other psychiatric disorders1, 2, 3. The structural variations associated with schizophrenia can involve several genes and the phenotypic syndromes, or the 'genomic disorders', have not yet been characterized4. Single nucleotide polymorphism (SNP)-based g enome-wide association studies with the potential to implicate individual genes in complex diseases may reveal underlying biological pathways. Here we combined SNP data from several large genome-wide scans and followed up the most significant association signals. We found significant association with several markers spanning the major histocompatibility complex (MHC) region on chromosome 6p21.3-22.1, a marker located upstream of the neurogranin gene (NRGN) on 11q24.2 and a marker in intron four of transcription factor 4 (TCF4) on 18q21.2. Our findings implicating the MHC region are consistent with an immune component to schizophrenia risk, whereas the association with NRGN and TCF4 points to perturbation of pathways involved in brain development, memory and cognition.
• Common polygenic variation contributes to risk of schizophrenia and bipolar disorder
  - Nature 460(7256):748-752 (2009)
  Schizophrenia is a severe mental disorder with a lifetime risk of about 1%, characterized by hallucinations, delusions and cognitive deficits, with heritability estimated at up to 80%1, 2. We performed a genome-wide association study of 3,322 European individuals with schizophrenia and 3,587 controls. Here we show, using two analytic approaches, the extent to which common genetic variation underlies the risk of schizophrenia. First, we implicate the major histocompatibility complex. Second, we provide molecular genetic evidence for a substantial polygenic component to the risk of schizophrenia involving thousands of common alleles of very small effect. We show that this component also contributes to the risk of bipolar disorder, but not to several non-psychiatric diseases.
• Common variants on chromosome 6p22.1 are associated with schizophrenia
  - Nature 460(7256):753-757 (2009)
  Schizophrenia, a devastating psychiatric disorder, has a prevalence of 0.5–1%, with high heritability (80–85%) and complex transmission1. Recent studies implicate rare, large, high-penetrance copy number variants in some cases2, but the genes or biological mechanisms that underlie susceptibility are not known. Here we show that schizophrenia is significantly associated with single nucleotide polymorphisms (SNPs) in the extended major histocompatibility complex region on chromosome 6. We carried out a genome-wide association study of common SNPs in the Molecular Genetics of Schizophrenia (MGS) case-control sample, and then a meta-analysis of data from the MGS, International Schizophrenia Consortium and SGENE data sets. No MGS finding achieved genome-wide statistical significance. In the meta-analysis of European-ancestry subjects (8,008 cases, 19,077 controls), significant association with schizophrenia was observed in a region of linkage disequilibrium on chromosome 6p22.1 (P = 9.54 10-9). This region includes a histone gene cluster and several immunity-related genes—possibly implicating aetiological mechanisms involving chromatin modification, transcriptional regulation, autoimmunity and/or infection. These results demonstrate that common schizophrenia susceptibility alleles can be detected. The characterization of these signals will suggest important directions for research on susceptibility mechanisms.
• Switch in FGF signalling initiates glial differentiation in the Drosophila eye
  Franzdóttir SR Engelen D Yuva-Aydemir Y Schmidt I Aho A Klämbt C - Nature 460(7256):758-761 (2009)
  The formation of a complex nervous system requires the intricate interaction of neurons and glial cells. Glial cells generally migrate over long distances before they initiate their differentiation, which leads to wrapping and insulation of axonal processes1, 2. The molecular pathways coordinating the switch from glial migration to glial differentiation are largely unknown3. Here we demonstrate that, within the Drosophila eye imaginal disc, fibroblast growth factor (FGF) signalling coordinates glial proliferation, migration and subsequent axonal wrapping. Glial differentiation in the Drosophila eye disc requires a succession from glia–glia interaction to glia–neuron interaction4. The neuronal component of the fly eye develops in the peripheral nervous system within the eye–antennal imaginal disc, whereas glial cells originate from a pool of central-nervous-system-derived progenitors and migrate onto the eye imaginal disc5, 6, 7, 8. Initially, glial-derived Pyramus , an FGF8-like ligand, modulates glial cell number and motility. A switch to neuronally expressed Thisbe, a second FGF8-like ligand, then induces glial differentiation. This switch is accompanied by an alteration in the intracellular signalling pathway through which the FGF receptor channels information into the cell. Our findings reveal how a switch from glia–glia interactions to glia–neuron interactions can trigger formation of glial membrane around axonal trajectories. These results disclose an evolutionarily conserved control mechanism of axonal wrapping2, indicating that Drosophila might serve as a model to understand glial disorders in humans.
• Proteome-wide cellular protein concentrations of the human pathogen Leptospira interrogans
  Malmström J Beck M Schmidt A Lange V Deutsch EW Aebersold R - Nature 460(7256):762-765 (2009)
  Mass-spectrometry-based methods for relative proteome quantification have broadly affected life science research. However, important research directions, particularly those involving mathematical modelling and simulation of biological processes, also critically depend on absolutely quantitative data—that is, knowledge of the concentration of the expressed proteins as a function of cellular state. Until now, absolute protein concentration measurements of a considerable fraction of the proteome (73%) have only been derived from genetically altered Saccharomyces cerevisiae cells1, a technique that is not directly portable from yeast to other species. Here we present a mass-spectrometry-based strategy to determine the absolute quantity, that is, the average number of protein copies per cell in a cell population, for a large fraction of the proteome in genetically unperturbed cells. Applying the technology to the human pathogen Leptospira interrogans, a spirochete responsi ble for leptospirosis2, we generated an absolute protein abundance scale for 83% of the mass-spectrometry-detectable proteome, from cells at different states. Taking advantage of the unique cellular dimensions of L. interrogans, we used cryo-electron tomography morphological measurements to verify, at the single-cell level, the average absolute abundance values of selected proteins determined by mass spectrometry on a population of cells. Because the strategy is relatively fast and applicable to any cell type, we expect that it will become a cornerstone of quantitative biology and systems biology.
• Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year
  - Nature 460(7256):766 (2009)
  Nature 457, 459–462 (2009) In this Letter, we reported trends on reconstructed temperature histories for different areas of the Antarctic continent. The confidence levels on the trends, as given in the text, did not take into account the reduced degrees of freedom in the time series due to autocorrelation. We report in Table 1 the corrected values, based on a two-tailed t-test, with the number of degrees of freedom adjusted for autocorrelation, using Neffective = N(1 - r)/(1 + r), in which N is the sample size and r is the lag-1 autocorrelation coefficient of the residuals of the detrended time series. The median of r is 0.27, resulting in a reduction in the degrees of freedom from N = 600 to Neffective = 345 for the monthly time series. We also include results of a further calculation that takes into account both the variance and the uncertainty in the reconstructed temperatures. We performed Monte-Carlo simulations of the reconstructed temperatures using a Gaussian distribution with variance equal to the unresolved variance from the split calibration/verification tests described in the paper. Confidence bounds were obtained by detrending each simulation and obtaining the lag-1 autocorrelation coefficient and variance of the residuals; a random realization of Gaussian noise having the same lag-1 autocorrelation coefficient and variance was then added to the trend, and a new trend was calculated. The 2.5th and 97.5th percentiles of the 10,000 simulated trends give the 95% confidence bounds. For the case of zero unresolved variance, this calculation converges on the same value as the two-tailed t-test, above. The 95% confidence minimum trend value is given by the 5th percentile values of the simulated trends, last row of Table 1. The corrected confidence levels do not change the assessed significance of trends, nor any of the primary conclusions of the paper. We also note that there is a typographical error in Supplementary Table 1: the correct location of Automatic Weather Station 'Harry' is 83.0° S, 238.6° E. The position of this station on the maps in the paper is correct.
• Expatriate
  - Nature 460(7256):772 (2009)
  Contact has been made.