Nature contents: 21 November 2013

Can't view this email? Click here to view in your browser.     Volume 503 Number 7476      nature •Visit Nature homepage •Subscribe to Nature •View Table of Contents The science that matters. Every week.               A comprehensive diagnostic of Brazil's large cities  The Center for Metropolitan Studies, a FAPESP research center, tracks the major problems and dynamic potential of metropolitan regions FAPESP is among the largest patent filers in Brazil  Sign up for FAPESP's free weekly newsletter with the latest developments of Brazilian science       Jump to the content that matters to you View Table of Contents ▶ ▼ News & Comment   ▼ Biological Sciences   ▼ Chemical Sciences   ▼ Physical Sciences   ▼ Earth & Environmental Sciences   ▼ Careers & Jobs       This week's highlights     Earth & Environmental Sciences More Earth & Environmental sciences ▼   Global carbon dioxide emissions from inland waters   Carbon dioxide transfer from inland waters to the atmosphere, known as CO2 evasion, is an important component of the global carbon cycle, but comprehensive estimates of global CO2 evasion are lacking. Peter Raymond and colleagues analysed regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. They estimate a global CO2 evasion rate of 2.1 petagrams of carbon per year - about two times higher than previous global estimates. The results indicate that a much higher proportion of CO2 'leaks' into the atmosphere from rivers and streams than from lakes and reservoirs.       Physical Sciences More Physical sciences ▼   An Earth-sized planet with an Earth-like density   A few exoplanets of about the size or mass of Earth have been discovered. Now, for the first time, both size and mass have been determined for one of them. Kepler-78B, first described in August this year, is close-in to its host star, which it orbits every 8.5 hours. Francesco Pepe and co-workers place the mass of at around 1.86 Earth masses, with a density of around 5.57 g cm-3, very similar to Earth's and consistent with an Earth-like composition of rock and iron. And though Earth-like in some respects, Kepler-78b is vastly hotter than Earth.       Biological Sciences More Biological sciences ▼   Experimental evidence for the influence of group size on cultural complexity   An important human attribute is the capacity for cumulative culture - passing on learned behaviours from generation to generation. Theory suggests that population size is an important factor in cultural development. Working with groups of volunteers playing an experimental cultural game, Maxime Derex et al. find evidence to support this prediction. They show that, during an iterated process, small groups are unable to maintain the ability to complete a complex task or improve on a simple one, whereas larger groups can improve both types of task over time.           Speed. Resolution. Clarity. Accuracy. The Hamamatsu NanoZoomer Series delivers all of this and more. The ultimate digital whole-slide scanner and virtual microscopy tool, the NanoZoomer delivers reliable, robust scanning 24/7/365 at the touch of a button. Outstanding features include high sensitivity, fast scanning, flexible fluorescence capabilities, and a Z-stack feature to accommodate thicker tissue samples.           Podcast & Video     In this week's podcast: an ancient genome gives clues to Native American ancestry, how graphene researchers plan to spend a big EU grant, and teenagers doing novel research at school. In our latest video feature: scientists engineer tiny ridges on super-hydrophobic surfaces to make water drops bounce off them more quickly.         News & Comment Read daily news coverage▶ ▲top               THIS WEEK           Editorials                   Climate negotiations soldier on ▶     As the Warsaw conference on the climate wraps up this week, there is reason for hope despite several well-publicized setbacks.             The new zoo ▶     Changes to the international zoological code are to be welcomed, despite continuing dissent.             Space spectacular ▶     Nature doesn't usually do film reviews, but Gravity is a true great.             World View                   Thrill of space exploration is a universal constant ▶     In the film Gravity, Sandra Bullock plays Everywoman, and reminds Colin Macilwain how inspiring science and discovery still can be.             Seven Days                   Seven days: 15–21 November 2013 ▶     The week in science: Test flight for volcano-ash sensor, Japan scales back emissions goals, and rare mammal caught on film.             NEWS IN FOCUS           Mexico bolsters science funding ▶     President aims to boost spending and reform research laws.             PLOS profits prompt revamp ▶     Incoming boss plans peer-review shake-up at Public Library of Science.             Budget crunch hits Keeling's curves ▶     Scientist struggles to maintain long-standing carbon dioxide record and more recent atmospheric-oxygen monitor.             Fences divide lion conservationists ▶     Some say enclosures offer protection, others maintain they are a menace.             Haiyan prompts risk research ▶     Geologists, engineers and social scientists are poised to swoop in before reconstruction gets under way.             Astronomers call for X-ray polarimeter ▶     NASA explorer programme raises hopes of mapping directional light from pulsars and black holes.             Features                   Graphene: The quest for supercarbon ▶     Graphene's dazzling properties promise a technological revolution, but Europe may have to spend a billion euros to overcome some fundamental problems.             HPV: Sex, cancer and a virus ▶     Human papillomavirus is causing a new form of head and neck cancer— leaving researchers scrambling to understand risk factors, tests and treatments.             COMMENT           Reproducibility: The risks of the replication drive ▶     The push to replicate findings could shelve promising research and unfairly damage the reputations of careful, meticulous scientists, says Mina Bissell.             Policy: Twenty tips for interpreting scientific claims ▶     This list will help non-scientists to interrogate advisers and to grasp the limitations of evidence, say William J. Sutherland, David Spiegelhalter and Mark A. Burgman.             Books and Arts                   In retrospect: Brave New World ▶     Philip Ball reconsiders the mix of dystopian science fiction and satire 50 years after Aldous Huxley's death.             Anthropology: The science of impunity ▶     Tanguy Chouard rates a film probing the psyches of Indonesia's paramilitary killers.             Q&A: Surfing scientist ▶     Historian Peter Westwick and his colleague Peter Neushul thought up their scientific history of surfing, The World in the Curl (Crown, 2013), on boards off the coast of California. As the winter surfing season gets into full swing, Westwick talks about warfare, wetsuits, climate change and forecasting surf.             Correspondence                   Online education: MOOCs taken by educated few Ezekiel J. Emanuel | Islamic law: Backing up forensic DNA evidence Mushtaq Hussain, Ammara Mushtaq | Heritability: Smarten up on intelligence genetics M. Velden | Bibliometrics: Database differences not citation errors Mohammad H. Nowroozzadeh             Correction                   Corrections ▶                 nature.com webcasts Macmillan Science Communication presents a custom webcast and live Q & A: Drug-induced liver injury: Genomic approaches to improve risk management Thursday December 5 There are two live sessions targeted at different time zones that you can join:  Europe and the Middle East: London 2pm GMT / Dubai 6pm GST   USA: San Francisco 10am PST / New York 1pm EST   Sponsored by: Agilent         Biological Sciences ▲top             RESEARCH           Latest Online                   Drug discovery: Pocket of opportunity ▶     Gideon Bollag, Chao Zhang             Systems biology: How bacteria choose a lifestyle ▶     James C. W. Locke             Ecology: A leak in the loop ▶     Katharine N. Suding             Activation and allosteric modulation of a muscarinic acetylcholine receptor ▶     Andrew C. Kruse, Aaron M. Ring, Aashish Manglik et al.     Very little is known about how a G-protein-coupled receptor (GPCR) transitions from an inactive to an active state, but this study has solved the X-ray crystal structures of the human M2 muscarinic acetylcholine receptor bound to a high-affinity agonist in an active state and to a high-affinity agonist and a small-molecule allosteric modulator in an active state; the structures provide insights into the activation mechanism and allosteric modulation of muscarinic receptors.             Memory and modularity in cell-fate decision making ▶     Thomas M. Norman, Nathan D. Lord, Johan Paulsson et al.     This study shows that Bacillus subtilis switches from a solitary, motile lifestyle to a multicellular, sessile state in a random, memoryless fashion, but that the underlying gene network is buffered against its own stochastic variation to tightly time the reverse transition; thus bacteria keep track of time to force their progeny to cooperate during the earliest stage of multicellular growth.             Divergent angiocrine signals from vascular niche balance liver regeneration and fibrosis ▶     Bi-Sen Ding, Zhongwei Cao, Raphael Lis et al.     Divergent angiocrine signals from liver sinusoidal endothelial cells elicit regeneration after immediate injury and provoke fibrosis after chronic insult.             Antibacterial membrane attack by a pore-forming intestinal C-type lectin ▶     Sohini Mukherjee, Hui Zheng, Mehabaw G. Derebe et al.     Secreted C-type lectins protect the intestinal epithelium from Gram-positive bacteria; this study shows that for the C-type lectin RegIIIα, bacterial killing occurs in a two-step process whereby the lectin first binds to bacterial peptidoglycans then oligomerizes on the bacterial membrane to form a permeabilizing pore.             Coupled GTPase and remodelling ATPase activities form a checkpoint for ribosome export ▶     Yoshitaka Matsuo, Sander Granneman, Matthias Thoms et al.     Two proteins are identified in yeast that regulate the timing of pre-ribosome export from the nucleus; Nug2 binds pre-60S particles until they are ready for export, at which time Nug2 is replaced by the export adaptor Nmd3, enabling the export machinery to recognise the pre-ribosome that is ready to be transferred to the cytoplasm.             Structural basis for recognition of synaptic vesicle protein 2C by botulinum neurotoxin A ▶     Roger M. Benoit, Daniel Frey, Manuel Hilbert et al.     Botulinum neurotoxin A (BoNT/A) is considered the most toxic substance known but is also used as a therapeutic drug for a growing number of diseases and conditions; researchers have now obtained a high-resolution crystal structure of the receptor-binding domain of the BoNT/A in complex with the luminal domain of synaptic vesicle protein 2C (SV2C), one of its receptors, allowing the identification of a peptide that can inhibit complex formation.             Low investment in sexual reproduction threatens plants adapted to phosphorus limitation ▶     Yuki Fujita, Harry Olde Venterink, Peter M. van Bodegom et al.     Plant life-history traits, notably plant investments in growth versus reproduction, can explain the impact of nitrogen:phosphorus stoichiometry on plant species richness; compared with plants in nitrogen-limited communities, plants in phosphorus-limited communities (in which endangered plant species are more common) invest little in phosphorus-intense activity such as sexual reproduction and have conservative leaf traits.             Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans ▶     Maanasa Raghavan, Pontus Skoglund, Kelly E. Graf et al.     Draft genomes of two south-central Siberian individuals dating to 24,000 and 17,000 years ago show that they are genetically closely related to modern-day western Eurasians and Native Americans but not to east Asians; the results have implications for our understanding of the origins of Native Americans.             Prefrontal parvalbumin interneurons shape neuronal activity to drive fear expression ▶     Julien Courtin, Fabrice Chaudun, Robert R. Rozeske et al.     Single-unit recordings and optogenetic manipulations in mice undergoing auditory fear conditioning show that fear expression is related to the phasic inhibition of prefrontal cortex (PFC) parvalbumin interneurons; inhibition disinhibits PFC projection neurons and synchronizes their firing, leading to fear expression.             K-Ras(G12C) inhibitors allosterically control GTP affinity and effector interactions ▶     Jonathan M. Ostrem, Ulf Peters, Martin L. Sos et al.     Small molecules are developed that irreversibly bind to the common G12C mutant of K-Ras but not the wild-type protein; crystallographic studies reveal the formation of an allosteric pocket that is not apparent in previous Ras studies, and the small molecules shift the affinity of K-Ras to favour GDP over GTP.             Self-reinforcing impacts of plant invasions change over time ▶     Stephanie G. Yelenik, Carla M. D'Antonio     Plant invasions are thought to alter the ecosystem in a way that disadvantages the native species, making re-establishment after eradication difficult; here, on returning to a site at which an invasive plant altered nitrogen-mineralization levels several decades ago, mineralization is found to have returned to pre-invasion levels, although these new conditions favour new invaders over the natives.             Crystal structures of the Lsm complex bound to the 3′ end sequence of U6 small nuclear RNA ▶     Lijun Zhou, Jing Hang, Yulin Zhou et al.     The crystal structure of the Lsm protein ring of the U6 small nuclear ribonucleoprotein (snRNP), with and without an RNA comprising the 3′ end of the U6 small nuclear RNA, is solved here; this structure provides insight into the function of U6 snRNP in precursor messenger RNA splicing.             Articles and Letters                   Nanog, Pou5f1 and SoxB1 activate zygotic gene expression during the maternal-to-zygotic transition ▶     Miler T. Lee, Ashley R. Bonneau, Carter M. Takacs et al.     This study investigates how zygotic transcription is initiated and the maternal transcripts cleared in the zebrafish embryo: using loss-of-function analyses, high-throughput transcriptome sequencing and ribosome footprinting, the important roles of pluripotency factors Nanog, Pou5f1 and SoxB1 during these processes are identified.             Activated ClpP kills persisters and eradicates a chronic biofilm infection ▶     B. P. Conlon, E. S. Nakayasu, L. E. Fleck et al.     Dormant bacterial persister cells evade antibiotic destruction and their survival gives rise to some chronic infections; this study reveals that persister cells can be eradicated with a compound activating the bacterial protease ClpP, providing an effective biofilm treatment in vitro and in mouse chronic infection models.             DNMT1-interacting RNAs block gene-specific DNA methylation ▶     Annalisa Di Ruscio, Alexander K. Ebralidze, Touati Benoukraf et al.     RNAs are shown to interact with DNA methyltransferase 1 and prevent DNA methylation of genes at their specific locus, providing evidence that active transcription directly regulates DNA methylation levels.             Experimental evidence for the influence of group size on cultural complexity ▶     Maxime Derex, Marie-Pauline Beugin, Bernard Godelle et al.     A dual-task computer game played by groups of different sizes is used to show that cultural evolution (the maintenance or improvement of cultural knowledge) strongly depends on population size; in larger groups of players, higher cultural complexity and cultural trait diversity are maintained, and improvements to existing cultural traits are more frequent.             A canonical to non-canonical Wnt signalling switch in haematopoietic stem-cell ageing ▶     Maria Carolina Florian, Kalpana J. Nattamai, Karin Dörr et al.     This study identifies a shift from canonical to non-canonical Wnt signalling in ageing haematopoietic stem cells (HSCs); elevated expression of Wnt5a in aged HSCs has a causal role in stem-cell ageing, and this is mediated by the small Rho GTPase Cdc42.             Staphylococcus δ-toxin induces allergic skin disease by activating mast cells ▶     Yuumi Nakamura, Jon Oscherwitz, Kemp B. Cease et al.     Staphylococcus aureus δ-toxin is an inducer of mast cell degranulation in mice and is important for promoting inflammatory skin disease.             HIV-1 evades innate immune recognition through specific cofactor recruitment ▶     Jane Rasaiyaah, Choon Ping Tan, Adam J. Fletcher et al.     Human immunodeficiency virus (HIV)-1 is shown here to depend on the recruitment to the HIV-1 capsid of specific cofactors involved in orchestrating nuclear entry and targeting; when these capsid–cofactor interactions are prevented either by virus mutation, cofactor depletion or pharmacological inhibition of cofactor recruitment, viral DNA can be detected by innate immune sensors.             Antigen-specific B-cell receptor sensitizes B cells to infection by influenza virus ▶     Stephanie K. Dougan, Joseph Ashour, Roos A. Karssemeijer et al.     Transnuclear mice are generated from B cells with a receptor specific for the haemagglutinin of influenza A virus; the authors show that influenza virus can infect and deplete haemagglutinin-specific B cells in the lung, which might confer a replicative advantage to the virus and allow it to evade an early neutralizing response.             The nuclear receptor Rev-erbα controls circadian thermogenic plasticity ▶     Zachary Gerhart-Hines, Dan Feng, Matthew J. Emmett et al.     The nuclear receptor Rev-erbα, a powerful repressor of transcription, is shown to link circadian and thermogenic networks by regulating the function of brown adipose tissue.             Temperature-dependent regulation of flowering by antagonistic FLM variants ▶     David Posé, Leonie Verhage, Felix Ott et al.     Temperature-dependent alternative splicing of FLOWERING LOCUS M (FLM) results in two protein products, FLM-β and FLM-δ, that regulate the onset of flowering in Arabidopsis; at cooler temperatures FLM-β represses flowering, whereas at higher temperatures, the plant preferentially produces FLM-δ, which promotes flowering.             Precision is essential for efficient catalysis in an evolved Kemp eliminase ▶     Rebecca Blomberg, Hajo Kries, Daniel M. Pinkas et al.     A computationally designed enzyme that was evolved to accelerate a chemical reaction 6 × 108-fold approaches the exceptional efficiency of highly optimized natural enzymes and provides valuable lessons for the creation of more sophisticated artificial catalysts.             Structural basis for ligase-specific conjugation of linear ubiquitin chains by HOIP ▶     Benjamin Stieglitz, Rohini R. Rana, Marios G. Koliopoulos et al.     The crystal structure of a complex between the catalytic core of the HOIP subunit of the E3 ligase LUBAC and ubiquitin is reported, yielding insight into the ubiquitin transfer reaction and explaining how HOIP is capable of synthesizing linear ubiquitin chains with high specificity.             News & Views                   Plant biomechanics: High-endurance algae ▶     Emily Carrington             Biogeochemistry: Conduits of the carbon cycle ▶     Bernhard Wehrli             Antibiotics: Killing the survivors ▶     Kenn Gerdes, Hanne Ingmer             Human evolution: Group size determines cultural complexity ▶     Peter Richerson             HIV: Slipping under the radar ▶     Stephen P. Goff             Drug discovery: Pocket of opportunity ▶     Gideon Bollag, Chao Zhang             Systems biology: How bacteria choose a lifestyle ▶     James C. W. Locke             Ecology: A leak in the loop ▶     Katharine N. Suding             Research Highlights                   Cultural anthropology: Biology tool uncloaks folk-tale evolution | Lab methods: A strict diet for Drosophila | Marine ecosystems: Nutrient threat of seafood farms | Immunology: Cells that hurt rather than heal | Archaeology: Teeth nibble away at invasion theory | Animal behaviour: Phantom road frightens birds | Evolution: Fish babies bigger in toxic waters | Zoology: Sex messes with a sea slug's head | Autoimmunity: Wheat not to blame for coeliac rise         NEWS & COMMENT           HPV: Sex, cancer and a virus | Reproducibility: The risks of the replication drive | In retrospect: Brave New World | Anthropology: The science of impunity | Heritability: Smarten up on intelligence genetics | The new zoo | Fences divide lion conservationists             More Biological Sciences ▶                 RNA-Seq Promotion on HiSeq or Ion Proton  Starting at $450/Sample! Why Choose BGI Tech? High Quality Data, highly experienced (45,000 RNA-Seq samples sequenced by BGI to date), and strong Bioinformatics. Valid for Americas and Europe only through November 30th. Contact us to get started!         Chemical Sciences ▲top             RESEARCH           Latest Online                   Drug discovery: Pocket of opportunity ▶     Gideon Bollag & Chao Zhang             Planetary science: A chunk of ancient Mars ▶     Harry Y. McSween             Activation and allosteric modulation of a muscarinic acetylcholine receptor ▶     Andrew C. Kruse, Aaron M. Ring, Aashish Manglik, Jianxin Hu, Kelly Hu et al.     Very little is known about how a G-protein-coupled receptor (GPCR) transitions from an inactive to an active state, but this study has solved the X-ray crystal structures of the human M2 muscarinic acetylcholine receptor bound to a high-affinity agonist in an active state and to a high-affinity agonist and a small-molecule allosteric modulator in an active state; the structures provide insights into the activation mechanism and allosteric modulation of muscarinic receptors.             Origin and age of the earliest Martian crust from meteorite NWA 7533 ▶     M. Humayun, A. Nemchin, B. Zanda, R. H. Hewins, M. Grange et al.     Chemical analysis of the meteorite NWA 7533 indicates that it may be a Martian regolith breccia and, if so, that the crust of Mars may have formed in the first 100 million years of the planet’s history.             K-Ras(G12C) inhibitors allosterically control GTP affinity and effector interactions ▶     Jonathan M. Ostrem, Ulf Peters, Martin L. Sos, James A. Wells & Kevan M. Shokat     Small molecules are developed that irreversibly bind to the common G12C mutant of K-Ras but not the wild-type protein; crystallographic studies reveal the formation of an allosteric pocket that is not apparent in previous Ras studies, and the small molecules shift the affinity of K-Ras to favour GDP over GTP.             Coupled GTPase and remodelling ATPase activities form a checkpoint for ribosome export ▶     Yoshitaka Matsuo, Sander Granneman, Matthias Thoms, Rizos-Georgios Manikas, David Tollervey et al.     Two proteins are identified in yeast that regulate the timing of pre-ribosome export from the nucleus; Nug2 binds pre-60S particles until they are ready for export, at which time Nug2 is replaced by the export adaptor Nmd3, enabling the export machinery to recognise the pre-ribosome that is ready to be transferred to the cytoplasm.             Structural basis for recognition of synaptic vesicle protein 2C by botulinum neurotoxin A ▶     Roger M. Benoit, Daniel Frey, Manuel Hilbert, Josta T. Kevenaar, Mara M. Wieser et al.     Botulinum neurotoxin A (BoNT/A) is considered the most toxic substance known but is also used as a therapeutic drug for a growing number of diseases and conditions; researchers have now obtained a high-resolution crystal structure of the receptor-binding domain of the BoNT/A in complex with the luminal domain of synaptic vesicle protein 2C (SV2C), one of its receptors, allowing the identification of a peptide that can inhibit complex formation.             Crystal structures of the Lsm complex bound to the 3′ end sequence of U6 small nuclear RNA ▶     Lijun Zhou, Jing Hang, Yulin Zhou, Ruixue Wan, Guifeng Lu et al.     The crystal structure of the Lsm protein ring of the U6 small nuclear ribonucleoprotein (snRNP), with and without an RNA comprising the 3′ end of the U6 small nuclear RNA, is solved here; this structure provides insight into the function of U6 snRNP in precursor messenger RNA splicing.             Articles and Letters                   Global carbon dioxide emissions from inland waters ▶     Peter A. Raymond, Jens Hartmann, Ronny Lauerwald, Sebastian Sobek, Cory McDonald et al.     An analysis of regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity yields a global CO2 evasion rate of 2.1 × 1015 grams of carbon per year, which is higher than previous estimates owing to a larger contribution from streams and rivers.             Precision is essential for efficient catalysis in an evolved Kemp eliminase ▶     Rebecca Blomberg, Hajo Kries, Daniel M. Pinkas, Peer R. E. Mittl, Markus G. Grütter et al.     A computationally designed enzyme that was evolved to accelerate a chemical reaction 6 × 108-fold approaches the exceptional efficiency of highly optimized natural enzymes and provides valuable lessons for the creation of more sophisticated artificial catalysts.             Structural basis for ligase-specific conjugation of linear ubiquitin chains by HOIP ▶     Benjamin Stieglitz, Rohini R. Rana, Marios G. Koliopoulos, Aylin C. Morris-Davies, Veronique Schaeffer et al.     The crystal structure of a complex between the catalytic core of the HOIP subunit of the E3 ligase LUBAC and ubiquitin is reported, yielding insight into the ubiquitin transfer reaction and explaining how HOIP is capable of synthesizing linear ubiquitin chains with high specificity.             News & Views                   Biogeochemistry: Conduits of the carbon cycle ▶     Bernhard Wehrli             Drug discovery: Pocket of opportunity ▶     Gideon Bollag & Chao Zhang             Planetary science: A chunk of ancient Mars ▶     Harry Y. McSween             Research Highlights                   Marine ecosystems: Nutrient threat of seafood farms | Autoimmunity: Wheat not to blame for coeliac rise         NEWS & COMMENT           Graphene: The quest for supercarbon             More Chemical Sciences ▶               Physical Sciences ▲top             RESEARCH           Latest Online                   An exactly solvable model for quantum communications ▶     Graeme Smith, John A. Smolin     An exactly solvable information-theoretical model of communications with a fully quantum electromagnetic field yields explicit expressions for all point-to-point capacities—the maximum possible rates of data transmission—of noisy quantum channels, with implications for quantum key distribution and fibre-optic communications.             Articles and Letters                   An Earth-sized planet with an Earth-like density ▶     Francesco Pepe, Andrew Collier Cameron, David W. Latham et al.     Data from the Kepler spacecraft and the HARPS-N ground-based spectrograph indicate that the extrasolar planet Kepler-78b has a mean density similar to that of Earth and imply that it is composed of rock and iron.             A rocky composition for an Earth-sized exoplanet ▶     Andrew W. Howard, Roberto Sanchis-Ojeda, Geoffrey W. Marcy et al.     Doppler spectroscopic measurements of the mass of the Earth-sized planet Kepler-78b reveal that its mean density is similar to Earth's, suggesting a composition of rock and iron.             Reducing the contact time of a bouncing drop ▶     James C. Bird, Rajeev Dhiman, Hyuk-Min Kwon et al.     There are many uses for surfaces that can stay dry, self-clean or resist icing, and many applications benefit from minimizing the contact time between a surface and any drops that may come into contact with it; drops are now shown to bounce off faster when using a superhydrophobic surface with a morphology that redistributes the liquid mass so that the centre of the drop assists in the recoil.             News & Views                   Extrasolar planets: An infernal Earth ▶     Drake Deming             Brief Communications Arising                   Three-dimensional imaging of dislocations ▶     Peter Rez, Michael M. J. Treacy             Miao et al. reply ▶     Jianwei Miao, Chien-Chun Chen, Chun Zhu et al.             Research Highlights                   Quantum physics: A record-breaking quantum bit         NEWS & COMMENT           Haiyan prompts risk research | Astronomers call for X-ray polarimeter | Graphene: The quest for supercarbon | Q&A: Surfing scientist | Bibliometrics: Database differences not citation errors             More Physical Sciences ▶               Earth & Environmental Sciences ▲top             RESEARCH           Latest Online                   Planetary science: A chunk of ancient Mars ▶     Harry Y. McSween             Ecology: A leak in the loop ▶     Katharine N. Suding             Late-twentieth-century emergence of the El Niño propagation asymmetry and future projections ▶     Agus Santoso, Shayne McGregor, Fei-Fei Jin et al.     The El Niño propagation asymmetry (in which sea surface temperature anomalies propagate eastwards during an extreme El Niño event) is shown to be caused by the variations in upper ocean currents in the equatorial Pacific Ocean; increased occurrences of the propagation asymmetry may be a manifestation of global greenhouse warming.             Low investment in sexual reproduction threatens plants adapted to phosphorus limitation ▶     Yuki Fujita, Harry Olde Venterink, Peter M. van Bodegom et al.     Plant life-history traits, notably plant investments in growth versus reproduction, can explain the impact of nitrogen:phosphorus stoichiometry on plant species richness; compared with plants in nitrogen-limited communities, plants in phosphorus-limited communities (in which endangered plant species are more common) invest little in phosphorus-intense activity such as sexual reproduction and have conservative leaf traits.             Origin and age of the earliest Martian crust from meteorite NWA 7533 ▶     M. Humayun, A. Nemchin, B. Zanda et al.     Chemical analysis of the meteorite NWA 7533 indicates that it may be a Martian regolith breccia and, if so, that the crust of Mars may have formed in the first 100 million years of the planet's history.             Articles and Letters                   Global carbon dioxide emissions from inland waters ▶     Peter A. Raymond, Jens Hartmann, Ronny Lauerwald et al.     An analysis of regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity yields a global CO2 evasion rate of 2.1 × 1015 grams of carbon per year, which is higher than previous estimates owing to a larger contribution from streams and rivers.             News & Views                   Extrasolar planets: An infernal Earth ▶     Drake Deming             Plant biomechanics: High-endurance algae ▶     Emily Carrington             Biogeochemistry: Conduits of the carbon cycle ▶     Bernhard Wehrli             Climate science: The challenge of hot drought ▶     Jonathan T. Overpeck             Planetary science: A chunk of ancient Mars ▶     Harry Y. McSween             Ecology: A leak in the loop ▶     Katharine N. 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