Showing papers by "Centre national de la recherche scientifique published in 2013"
TL;DR: This review focuses on the characterization of EVs and on currently proposed mechanisms for their formation, targeting, and function.
Abstract: Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, and RNA. Deficiencies in our knowledge of the molecular mechanisms for EV formation and lack of methods to interfere with the packaging of cargo or with vesicle release, however, still hamper identification of their physiological relevance in vivo. In this review, we focus on the characterization of EVs and on currently proposed mechanisms for their formation, targeting, and function.
6,141 citations
TL;DR: This work quantifies the kinetics of charge storage in T-Nb2O5: currents that vary inversely with time, charge-storage capacity that is mostly independent of rate, and redox peaks that exhibit small voltage offsets even at high rates.
Abstract: Pseudocapacitance is commonly associated with surface or near-surface reversible redox reactions, as observed with RuO2·xH2O in an acidic electrolyte. However, we recently demonstrated that a pseudocapacitive mechanism occurs when lithium ions are inserted into mesoporous and nanocrystal films of orthorhombic Nb2O5 (T-Nb2O5; refs 1, 2). Here, we quantify the kinetics of charge storage in T-Nb2O5: currents that vary inversely with time, charge-storage capacity that is mostly independent of rate, and redox peaks that exhibit small voltage offsets even at high rates. We also define the structural characteristics necessary for this process, termed intercalation pseudocapacitance, which are a crystalline network that offers two-dimensional transport pathways and little structural change on intercalation. The principal benefit realized from intercalation pseudocapacitance is that high levels of charge storage are achieved within short periods of time because there are no limitations from solid-state diffusion. Thick electrodes (up to 40 μm thick) prepared with T-Nb2O5 offer the promise of exploiting intercalation pseudocapacitance to obtain high-rate charge-storage devices.
3,725 citations
TL;DR: A high-quality sequence assembly of the zebrafish genome is generated, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map, providing a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebra fish-specific genes on chromosome 4 and chromosomal regions that influence sex determination.
Abstract: Zebrafish have become a popular organism for the study of vertebrate gene function. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of vertebrate gene function and increasingly, the study of human genetic disease. However, for effective modelling of human genetic disease it is important to understand the extent to which zebrafish genes and gene structures are related to orthologous human genes. To examine this, we generated a high-quality sequence assembly of the zebrafish genome, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map. Detailed automatic and manual annotation provides evidence of more than 26,000 protein-coding genes, the largest gene set of any vertebrate so far sequenced. Comparison to the human reference genome shows that approximately 70% of human genes have at least one obvious zebrafish orthologue. In addition, the high quality of this genome assembly provides a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebrafish-specific genes on chromosome 4 and chromosomal regions that influence sex determination.
3,573 citations
TL;DR: This study demonstrates the spontaneous intercalation of cations from aqueous salt solutions between two-dimensional (2D) Ti3C2 MXene layers, and provides a basis for exploring a large family of 2D carbides and carbonitrides in electrochemical energy storage applications using single- and multivalent ions.
Abstract: The intercalation of ions into layered compounds has long been exploited in energy storage devices such as batteries and electrochemical capacitors However, few host materials are known for ions much larger than lithium We demonstrate the spontaneous intercalation of cations from aqueous salt solutions between two-dimensional (2D) Ti3C2 MXene layers MXenes combine 2D conductive carbide layers with a hydrophilic, primarily hydroxyl-terminated surface A variety of cations, including Na+, K+, NH4+, Mg2+, and Al3+, can also be intercalated electrochemically, offering capacitance in excess of 300 farads per cubic centimeter (much higher than that of porous carbons) This study provides a basis for exploring a large family of 2D carbides and carbonitrides in electrochemical energy storage applications using single- and multivalent ions
3,018 citations
University of Tennessee1, Centre national de la recherche scientifique2, International Union for Conservation of Nature and Natural Resources3, Swedish University of Agricultural Sciences4, Missouri Botanical Garden5, University of Paris-Sud6, University of Girona7, Institut national de la recherche agronomique8, Charles University in Prague9, Academy of Sciences of the Czech Republic10, University of Porto11, University of Minho12, Paul Sabatier University13, Spanish National Research Council14
TL;DR: Recent progress in understanding invasion impacts and management is highlighted, and the challenges that the discipline faces in its science and interactions with society are discussed.
Abstract: Study of the impacts of biological invasions, a pervasive component of global change, has generated remarkable understanding of the mechanisms and consequences of the spread of introduced populations. The growing field of invasion science, poised at a crossroads where ecology, social sciences, resource management, and public perception meet, is increasingly exposed to critical scrutiny from several perspectives. Although the rate of biological invasions, elucidation of their consequences, and knowledge about mitigation are growing rapidly, the very need for invasion science is disputed. Here, we highlight recent progress in understanding invasion impacts and management, and discuss the challenges that the discipline faces in its science and interactions with society.
2,346 citations
TL;DR: In dit artikel zullen the authors LOFAR beschrijven: van de astronomische mogelijkheden met de nieuwe telescoop tot aan een nadere technische beshrijving of het instrument.
Abstract: LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. LOFAR's new capabilities, techniques and modus operandi make it an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results from the commissioning phase of this new radio observatory.
2,067 citations
TL;DR: Empirical evidence of shared genetic etiology for psychiatric disorders can inform nosology and encourages the investigation of common pathophysiologies for related disorders.
Abstract: Most psychiatric disorders are moderately to highly heritable. The degree to which genetic variation is unique to individual disorders or shared across disorders is unclear. To examine shared genetic etiology, we use genome-wide genotype data from the Psychiatric Genomics Consortium (PGC) for cases and controls in schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD). We apply univariate and bivariate methods for the estimation of genetic variation within and covariation between disorders. SNPs explained 17-29% of the variance in liability. The genetic correlation calculated using common SNPs was high between schizophrenia and bipolar disorder (0.68 ± 0.04 s.e.), moderate between schizophrenia and major depressive disorder (0.43 ± 0.06 s.e.), bipolar disorder and major depressive disorder (0.47 ± 0.06 s.e.), and ADHD and major depressive disorder (0.32 ± 0.07 s.e.), low between schizophrenia and ASD (0.16 ± 0.06 s.e.) and non-significant for other pairs of disorders as well as between psychiatric disorders and the negative control of Crohn's disease. This empirical evidence of shared genetic etiology for psychiatric disorders can inform nosology and encourages the investigation of common pathophysiologies for related disorders.
2,058 citations
University of Amsterdam1, University of Pennsylvania2, Washington University in St. Louis3, University of Freiburg4, Pasteur Institute5, University of California, San Francisco6, Laboratory of Molecular Biology7, VU University Amsterdam8, John Radcliffe Hospital9, French Institute of Health and Medical Research10, Centre national de la recherche scientifique11
TL;DR: It is proposed that ILCs should be categorized into three groups based on the cytokines that they can produce and the transcription factors that regulate their development and function.
Abstract: Innate lymphoid cells (ILCs) are a family of developmentally related cells that are involved in immunity and in tissue development and remodelling. Recent research has identified several distinct members of this family. Confusingly, many different names have been used to characterize these newly identified ILC subsets. Here, we propose that ILCs should be categorized into three groups based on the cytokines that they can produce and the transcription factors that regulate their development and function.
2,039 citations
Kyle S. Dawson1, David J. Schlegel2, Christopher P. Ahn1, Scott F. Anderson3 +181 more•Institutions (51)
TL;DR: The Baryon Oscillation Spectroscopic Survey (BOSS) as discussed by the authors was designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure.
Abstract: The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg2 to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Lyα forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyα forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance dA to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyα forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate DA (z) and H –1(z) parameters to an accuracy of 1.9% at z ~ 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.
1,938 citations
TL;DR: The most comprehensive meta-analysis to date by synthesizing the results of 228 studies examining biological responses to ocean acidification reveals decreased survival, calcification, growth, development and abundance in response to acidification, and suggests that other factors, such as nutritional status or source population, could cause substantial variation in organisms' responses.
Abstract: Ocean acidification represents a threat to marine species worldwide, and forecasting the ecological impacts of acidification is a high priority for science, management, and policy. As research on the topic expands at an exponential rate, a comprehensive understanding of the variability in organisms' responses and corresponding levels of certainty is necessary to forecast the ecological effects. Here, we perform the most comprehensive meta-analysis to date by synthesizing the results of 228 studies examining biological responses to ocean acidification. The results reveal decreased survival, calcification, growth, development and abundance in response to acidification when the broad range of marine organisms is pooled together. However, the magnitude of these responses varies among taxonomic groups, suggesting there is some predictable trait-based variation in sensitivity, despite the investigation of approximately 100 new species in recent research. The results also reveal an enhanced sensitivity of mollusk larvae, but suggest that an enhanced sensitivity of early life history stages is not universal across all taxonomic groups. In addition, the variability in species' responses is enhanced when they are exposed to acidification in multi-species assemblages, suggesting that it is important to consider indirect effects and exercise caution when forecasting abundance patterns from single-species laboratory experiments. Furthermore, the results suggest that other factors, such as nutritional status or source population, could cause substantial variation in organisms' responses. Last, the results highlight a trend towards enhanced sensitivity to acidification when taxa are concurrently exposed to elevated seawater temperature.
1,787 citations
University of St Andrews1, University of Oldenburg2, Natural History Museum3, Naturalis4, Centre national de la recherche scientifique5, Michigan State University6, University of Lausanne7, University of Wyoming8, Queen Mary University of London9, University of Sheffield10, International Institute for Applied Systems Analysis11, University of Oslo12, University of Vienna13, University of Vermont14, University of East Anglia15, Spanish National Research Council16, University of Cambridge17, University of Konstanz18, University of Zurich19, Royal Botanic Garden Edinburgh20, Harvard University21, Autonomous University of Madrid22, Swiss Federal Institute of Aquatic Science and Technology23, Boston University24, Max Planck Society25, University of Neuchâtel26, University of North Carolina at Chapel Hill27, Lehigh University28, American Museum of Natural History29, University of Montpellier30, University of Liverpool31, Jagiellonian University32, Uppsala University33, German Primate Center34
TL;DR: A perspective on the context and evolutionary significance of hybridization during speciation is offered, highlighting issues of current interest and debate and suggesting that the Dobzhansky–Muller model of hybrid incompatibilities requires a broader interpretation.
Abstract: Hybridization has many and varied impacts on the process of speciation. Hybridization may slow or reverse differentiation by allowing gene flow and recombination. It may accelerate speciation via adaptive introgression or cause near-instantaneous speciation by allopolyploidization. It may have multiple effects at different stages and in different spatial contexts within a single speciation event. We offer a perspective on the context and evolutionary significance of hybridization during speciation, highlighting issues of current interest and debate. In secondary contact zones, it is uncertain if barriers to gene flow will be strengthened or broken down due to recombination and gene flow. Theory and empirical evidence suggest the latter is more likely, except within and around strongly selected genomic regions. Hybridization may contribute to speciation through the formation of new hybrid taxa, whereas introgression of a few loci may promote adaptive divergence and so facilitate speciation. Gene regulatory networks, epigenetic effects and the evolution of selfish genetic material in the genome suggest that the Dobzhansky-Muller model of hybrid incompatibilities requires a broader interpretation. Finally, although the incidence of reinforcement remains uncertain, this and other interactions in areas of sympatry may have knock-on effects on speciation both within and outside regions of hybridization.
Centre national de la recherche scientifique1, Commonwealth Scientific and Industrial Research Organisation2, National Oceanic and Atmospheric Administration3, United States Department of Energy4, University of California, Irvine5, Seconda Università degli Studi di Napoli6, Central Maine Community College7, Max Planck Society8, Swiss Federal Institute for Forest, Snow and Landscape Research9, Utrecht University10, Carma11, National Center for Atmospheric Research12, University of East Anglia13, Massachusetts Institute of Technology14, VU University Amsterdam15, Goddard Space Flight Center16, University of Bern17, Nagoya University18, Imperial College London19, Royal Netherlands Meteorological Institute20, University of California, San Diego21, National Institute of Water and Atmospheric Research22
TL;DR: In this paper, the authors construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions.
Abstract: Methane is an important greenhouse gas, responsible for about 20% of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, their relative contributions to atmospheric methane levels are highly uncertain. As such, the factors responsible for the observed stabilization of atmospheric methane levels in the early 2000s, and the renewed rise after 2006, remain unclear. Here, we construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions. The resultant budgets suggest that data-driven approaches and ecosystem models overestimate total natural emissions. We build three contrasting emission scenarios-which differ in fossil fuel and microbial emissions-to explain the decadal variability in atmospheric methane levels detected, here and in previous studies, since 1985. Although uncertainties in emission trends do not allow definitive conclusions to be drawn, we show that the observed stabilization of methane levels between 1999 and 2006 can potentially be explained by decreasing-to-stable fossil fuel emissions, combined with stable-to-increasing microbial emissions. We show that a rise in natural wetland emissions and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006, although the relative contribution of these two sources remains uncertain. © 2013 Macmillan Publishers Limited.
TL;DR: This article presented the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5).
Abstract: We present the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5). This model includes an interactive carbon cycle, a representation of tropospheric and stratospheric chemistry, and a comprehensive representation of aerosols. As it represents the principal dynamical, physical, and bio-geochemical processes relevant to the climate system, it may be referred to as an Earth System Model. However, the IPSL-CM5 model may be used in a multitude of configurations associated with different boundary conditions and with a range of complexities in terms of processes and interactions. This paper presents an overview of the different model components and explains how they were coupled and used to simulate historical climate changes over the past 150 years and different scenarios of future climate change. A single version of the IPSL-CM5 model (IPSL-CM5A-LR) was used to provide climate projections associated with different socio-economic scenarios, including the different Representative Concentration Pathways considered by CMIP5 and several scenarios from the Special Report on Emission Scenarios considered by CMIP3. Results suggest that the magnitude of global warming projections primarily depends on the socio-economic scenario considered, that there is potential for an aggressive mitigation policy to limit global warming to about two degrees, and that the behavior of some components of the climate system such as the Arctic sea ice and the Atlantic Meridional Overturning Circulation may change drastically by the end of the twenty-first century in the case of a no climate policy scenario. Although the magnitude of regional temperature and precipitation changes depends fairly linearly on the magnitude of the projected global warming (and thus on the scenario considered), the geographical pattern of these changes is strikingly similar for the different scenarios. The representation of atmospheric physical processes in the model is shown to strongly influence the simulated climate variability and both the magnitude and pattern of the projected climate changes.
TL;DR: It is demonstrated by numerical investigations that an isolated skyrmion can be a stable configuration in a nanostructure, can be locally nucleated by injection of spin-polarized current, and can be displaced by current-induced spin torques, even in the presence of large defects.
Abstract: Magnetic skyrmions are topologically stable spin configurations, which usually originate from chiral interactions known as Dzyaloshinskii-Moriya interactions. Skyrmion lattices were initially observed in bulk non-centrosymmetric crystals, but have more recently been noted in ultrathin films, where their existence is explained by interfacial Dzyaloshinskii-Moriya interactions induced by the proximity to an adjacent layer with strong spin-orbit coupling. Skyrmions are promising candidates as information carriers for future information-processing devices due to their small size (down to a few nanometres) and to the very small current densities needed to displace skyrmion lattices. However, any practical application will probably require the creation, manipulation and detection of isolated skyrmions in magnetic thin-film nanostructures. Here, we demonstrate by numerical investigations that an isolated skyrmion can be a stable configuration in a nanostructure, can be locally nucleated by injection of spin-polarized current, and can be displaced by current-induced spin torques, even in the presence of large defects.
National Oceanography Centre, Southampton1, Stanford University2, Bar-Ilan University3, Centre national de la recherche scientifique4, University of Otago5, University of Tasmania6, McGill University7, University of Essex8, Pierre-and-Marie-Curie University9, ETH Zurich10, University of East Anglia11, University of Exeter12, Cornell University13, University of Vigo14, University of Pennsylvania15, University of California, Irvine16, Nagoya University17, Leibniz Institute of Marine Sciences18, Woods Hole Oceanographic Institution19, University of Bergen20, University of Tokyo21, University of Concepción22
TL;DR: In this paper, the authors reveal two broad regimes of phytoplankton nutrient limitation in the modern upper ocean: Nitrogen availability tends to limit productivity throughout much of the surface low-latitude ocean, where the supply of nutrients from the subsurface is relatively slow.
Abstract: Microbial activity is a fundamental component of oceanic nutrient cycles. Photosynthetic microbes, collectively termed phytoplankton, are responsible for the vast majority of primary production in marine waters. The availability of nutrients in the upper ocean frequently limits the activity and abundance of these organisms. Experimental data have revealed two broad regimes of phytoplankton nutrient limitation in the modern upper ocean. Nitrogen availability tends to limit productivity throughout much of the surface low-latitude ocean, where the supply of nutrients from the subsurface is relatively slow. In contrast, iron often limits productivity where subsurface nutrient supply is enhanced, including within the main oceanic upwelling regions of the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins and micronutrients other than iron may also (co-)limit marine phytoplankton. The spatial patterns and importance of co-limitation, however, remain unclear. Variability in the stoichiometries of nutrient supply and biological demand are key determinants of oceanic nutrient limitation. Deciphering the mechanisms that underpin this variability, and the consequences for marine microbes, will be a challenge. But such knowledge will be crucial for accurately predicting the consequences of ongoing anthropogenic perturbations to oceanic nutrient biogeochemistry.
TL;DR: A review of the current status of selected remote sensing algorithms for estimating land surface temperature from thermal infrared (TIR) data is presented in this article, along with a survey of the algorithms employed for obtaining LST from space-based TIR measurements.
TL;DR: Novel biological insights are revealed into the function of HH lipidation in the secretion and transport of this ligand and details of the signal transduction pathway, which involves Patched 1, Smoothened and GLI proteins, as well as, in vertebrates, primary cilia.
Abstract: The cloning of the founding member of the Hedgehog (HH) family of secreted proteins two decades ago inaugurated a field that has diversified to encompass embryonic development, stem cell biology and tissue homeostasis. Interest in HH signalling increased when the pathway was implicated in several cancers and congenital syndromes. The mechanism of HH signalling is complex and remains incompletely understood. Nevertheless, studies have revealed novel biological insights into this system, including the function of HH lipidation in the secretion and transport of this ligand and details of the signal transduction pathway, which involves Patched 1, Smoothened and GLI proteins (Cubitus interruptus in Drosophila melanogaster), as well as, in vertebrates, primary cilia.
Max Planck Society1, University of Innsbruck2, Centre national de la recherche scientifique3, ETH Zurich4, Stockholm University5, Oeschger Centre for Climate Change Research6, Tuscia University7, Potsdam Institute for Climate Impact Research8, University of Aberdeen9, International Institute for Applied Systems Analysis10, University of Antwerp11, University of Potsdam12
TL;DR: The mechanisms and impacts of climate extremes on the terrestrial carbon cycle are explored, and a pathway to improve the understanding of present and future impacts ofClimate extremes onThe terrestrial carbon budget is proposed.
Abstract: The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Continuing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that climate extremes such as droughts or storms can lead to a decrease in regional ecosystem carbon stocks and therefore have the potential to negate an expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget.
TL;DR: The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance.
Abstract: The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a ‘top 10’ list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly.
TL;DR: A new version of the general circulation model CNRM-CM has been developed jointly by CNRMs-GAME (Centre National de Recherches Meteorologiques-Groupe d'etudes de l’Atmosphere Meteorologique) and Cerfacs as discussed by the authors in order to contribute to phase 5 of the Coupled Model Intercomparison Project (CMIP5).
Abstract: A new version of the general circulation model CNRM-CM has been developed jointly by CNRM-GAME (Centre National de Recherches Meteorologiques—Groupe d’etudes de l’Atmosphere Meteorologique) and Cerfacs (Centre Europeen de Recherche et de Formation Avancee) in order to contribute to phase 5 of the Coupled Model Intercomparison Project (CMIP5). The purpose of the study is to describe its main features and to provide a preliminary assessment of its mean climatology. CNRM-CM5.1 includes the atmospheric model ARPEGE-Climat (v5.2), the ocean model NEMO (v3.2), the land surface scheme ISBA and the sea ice model GELATO (v5) coupled through the OASIS (v3) system. The main improvements since CMIP3 are the following. Horizontal resolution has been increased both in the atmosphere (from 2.8° to 1.4°) and in the ocean (from 2° to 1°). The dynamical core of the atmospheric component has been revised. A new radiation scheme has been introduced and the treatments of tropospheric and stratospheric aerosols have been improved. Particular care has been devoted to ensure mass/water conservation in the atmospheric component. The land surface scheme ISBA has been externalised from the atmospheric model through the SURFEX platform and includes new developments such as a parameterization of sub-grid hydrology, a new freezing scheme and a new bulk parameterisation for ocean surface fluxes. The ocean model is based on the state-of-the-art version of NEMO, which has greatly progressed since the OPA8.0 version used in the CMIP3 version of CNRM-CM. Finally, the coupling between the different components through OASIS has also received a particular attention to avoid energy loss and spurious drifts. These developments generally lead to a more realistic representation of the mean recent climate and to a reduction of drifts in a preindustrial integration. The large-scale dynamics is generally improved both in the atmosphere and in the ocean, and the bias in mean surface temperature is clearly reduced. However, some flaws remain such as significant precipitation and radiative biases in many regions, or a pronounced drift in three dimensional salinity.
TL;DR: In this paper, the authors used the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how these stressors may evolve over the course of the 21st century.
Abstract: Ocean ecosystems are increasingly stressed by human-induced changes of their physical, chemical and biological environment. Among these changes, warming, acidification, deoxygenation and changes in primary productivity by marine phytoplankton can be considered as four of the major stressors of open ocean ecosystems. Due to rising atmospheric CO 2 in the coming decades, these changes will be amplified. Here, we use the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how these stressors may evolve over the course of the 21st century. The 10 Earth system models used here project similar trends in ocean warming, acidification, deoxygenation and reduced primary productivity for each of the IPCC's representative concentration pathways (RCPs) over the 21st century. For the "business-as-usual" scenario RCP8.5, the model-mean changes in the 2090s (compared to the 1990s) for sea surface temperature, sea surface pH, global O 2 content and integrated primary productivity amount to p2.73 (±0.72) °C, −0.33 (±0.003) pH unit, −3.45 (±0.44)% and −8.6 (±7.9)%, respectively. For the high mitigation scenario RCP2.6, corresponding changes are +0.71 (±0.45) °C, −0.07 (±0.001) pH unit, −1.81 (±0.31)% and −2.0 (±4.1)%, respectively, illustrating the effectiveness of extreme mitigation strategies. Although these stressors operate globally, they display distinct regional patterns and thus do not change coincidentally. Large decreases in O 2 and in pH are simulated in global ocean intermediate and mode waters, whereas large reductions in primary production are simulated in the tropics and in the North Atlantic. Although temperature and pH projections are robust across models, the same does not hold for projections of subsurface O 2 concentrations in the tropics and global and regional changes in net primary productivity. These high uncertainties in projections of primary productivity and subsurface oxygen prompt us to continue inter-model comparisons to understand these model differences, while calling for caution when using the CMIP5 models to force regional impact models.
TL;DR: A droplet-based microfluidics protocol for high-throughput analysis and sorting of single cells, and a binding assay for detecting antibodies secreted from single mouse hybridoma cells is detailed.
Abstract: We present a droplet-based microfluidics protocol for high-throughput analysis and sorting of single cells. Compartmentalization of single cells in droplets enables the analysis of proteins released from or secreted by cells, thereby overcoming one of the major limitations of traditional flow cytometry and fluorescence-activated cell sorting. As an example of this approach, we detail a binding assay for detecting antibodies secreted from single mouse hybridoma cells. Secreted antibodies are detected after only 15 min by co-compartmentalizing single mouse hybridoma cells, a fluorescent probe and single beads coated with anti-mouse IgG antibodies in 50-pl droplets. The beads capture the secreted antibodies and, when the captured antibodies bind to the probe, the fluorescence becomes localized on the beads, generating a clearly distinguishable fluorescence signal that enables droplet sorting at ∼200 Hz as well as cell enrichment. The microfluidic system described is easily adapted for screening other intracellular, cell-surface or secreted proteins and for quantifying catalytic or regulatory activities. In order to screen ∼1 million cells, the microfluidic operations require 2-6 h; the entire process, including preparation of microfluidic devices and mammalian cells, requires 5-7 d.
TL;DR: Graphene superlattices such as this one provide a way of studying the rich physics expected in incommensurable quantum systems and illustrate the possibility of controllably modifying the electronic spectra of two-dimensional atomic crystals by varying their crystallographic alignment within van der Waals heterostuctures.
Abstract: Placing graphene on a boron nitride substrate and accurately aligning their crystallographic axes, to form a moire superlattice, leads to profound changes in the graphene’s electronic spectrum. In 1976 Douglas Hofstadter predicted that electrons in a lattice subjected to electrostatic and magnetic fields would show a characteristic energy spectrum determined by the interplay between two quantizing fields. The expected spectrum would feature a repeating butterfly-shaped motif, known as Hofstadter's butterfly. The experimental realization of the phenomenon has proved difficult because of the problem of producing a sufficiently disorder-free superlattice where the length scales for magnetic and electric field can truly compete with each other. Now that goal has been achieved — twice. Two groups working independently produced superlattices by placing ultraclean graphene (Ponomarenko et al.) or bilayer graphene (Kim et al.) on a hexagonal boron nitride substrate and crystallographically aligning the films at a precise angle to produce moire pattern superstructures. Electronic transport measurements on the moire superlattices provide clear evidence for Hofstadter's spectrum. The demonstrated experimental access to a fractal spectrum offers opportunities for the study of complex chaotic effects in a tunable quantum system. Superlattices have attracted great interest because their use may make it possible to modify the spectra of two-dimensional electron systems and, ultimately, create materials with tailored electronic properties1,2,3,4,5,6,7,8. In previous studies (see, for example, refs 1, 2, 3, 4, 5, 6, 7, 8), it proved difficult to realize superlattices with short periodicities and weak disorder, and most of their observed features could be explained in terms of cyclotron orbits commensurate with the superlattice1,2,3,4. Evidence for the formation of superlattice minibands (forming a fractal spectrum known as Hofstadter’s butterfly9) has been limited to the observation of new low-field oscillations5 and an internal structure within Landau levels6,7,8. Here we report transport properties of graphene placed on a boron nitride substrate and accurately aligned along its crystallographic directions. The substrate’s moire potential10,11,12 acts as a superlattice and leads to profound changes in the graphene’s electronic spectrum. Second-generation Dirac points13,14,15,16,17,18,19,20,21,22 appear as pronounced peaks in resistivity, accompanied by reversal of the Hall effect. The latter indicates that the effective sign of the charge carriers changes within graphene’s conduction and valence bands. Strong magnetic fields lead to Zak-type cloning23 of the third generation of Dirac points, which are observed as numerous neutrality points in fields where a unit fraction of the flux quantum pierces the superlattice unit cell. Graphene superlattices such as this one provide a way of studying the rich physics expected in incommensurable quantum systems7,8,9,22,23,24 and illustrate the possibility of controllably modifying the electronic spectra of two-dimensional atomic crystals by varying their crystallographic alignment within van der Waals heterostuctures25.
TL;DR: The carbohydrate-digestive capacity of a simplified but representative mini-microbiome is examined in order to highlight the abundance and variety of bacterial CAZymes that are represented in the human gut microbiota.
Abstract: The human genome encodes very few enzymes involved in the digestion of complex polysaccharides, and this deficit is compensated for by the myriad of carbohydrate-active enzymes (CAZymes) encoded by members of the gut microbiome. In this Analysis article, Henrissat and colleagues characterize the CAZymes present in a representative human mini-microbiome.
TL;DR: A multifunctional single-ion polymer electrolyte based on polyanionic block copolymers comprising polystyrene segments overcomes most of the above limitations, with a lithium-ion transport number close to unity, excellent mechanical properties and an electrochemical stability window spanning 5 V versus Li(+)/Li.
Abstract: Electrochemical energy storage is one of the main societal challenges of this century. The performances of classical lithium-ion technology based on liquid electrolytes have made great advances in the past two decades, but the intrinsic instability of liquid electrolytes results in safety issues. Solid polymer electrolytes would be a perfect solution to those safety issues, miniaturization and enhancement of energy density. However, as in liquids, the fraction of charge carried by lithium ions is small (\textless20%), limiting the power performances. Solid polymer electrolytes operate at 80 degrees C, resulting in poor mechanical properties and a limited electrochemical stability window. Here we describe a multifunctional single-ion polymer electrolyte based on polyanionic block copolymers comprising polystyrene segments. It overcomes most of the above limitations, with a lithium-ion transport number close to unity, excellent mechanical properties and an electrochemical stability window spanning 5V versus Li+/Li. A prototype battery using this polyelectrolyte outperforms a conventional battery based on a polymer electrolyte.
TL;DR: In this article, the reactivity of a class of high-capacity oxides with a single redox cation has been investigated and it has been shown that these oxides exhibit sustainable reversible capacities as high as 230 mAh/g−1 and good cycling behavior with no signs of voltage decay.
Abstract: Li-ion batteries have contributed to the commercial success of portable electronics and may soon dominate the electric transportation market provided that major scientific advances including new materials and concepts are developed. Classical positive electrodes for Li-ion technology operate mainly through an insertion-deinsertion redox process involving cationic species. However, this mechanism is insufficient to account for the high capacities exhibited by the new generation of Li-rich (Li1+xNiyCozMn(1−x−y−z)O2) layered oxides that present unusual Li reactivity. In an attempt to overcome both the inherent composition and the structural complexity of this class of oxides, we have designed structurally related Li2Ru1−ySnyO3 materials that have a single redox cation and exhibit sustainable reversible capacities as high as 230 mA h g−1. Moreover, they present good cycling behaviour with no signs of voltage decay and a small irreversible capacity. We also unambiguously show, on the basis of an arsenal of characterization techniques, that the reactivity of these high-capacity materials towards Li entails cumulative cationic (Mn+→M(n+1)+) and anionic (O2−→O22−) reversible redox processes, owing to the d-sp hybridization associated with a reductive coupling mechanism. Because Li2MO3 is a large family of compounds, this study opens the door to the exploration of a vast number of high-capacity materials.
University of Michigan1, Clark University2, Scripps Institution of Oceanography3, Trent University4, University of Colorado Boulder5, University of Bristol6, University of Alaska Fairbanks7, Cooperative Institute for Research in Environmental Sciences8, Centre national de la recherche scientifique9, Uppsala University10, Institute of Arctic and Alpine Research11, University of Innsbruck12, Utrecht University13, Dresden University of Technology14, University of Zurich15, University of Alberta16, University of Oslo17
TL;DR: It is found that glaciers in the Arctic, Canada, Alaska, coastal Greenland, the southern Andes, and high-mountain Asia contribute approximately as much melt water as the ice sheets themselves: 260 billion tons per year between 2003 and 2009, accounting for about 30% of the observed sea-level rise during that period.
Abstract: Glaciers distinct from the Greenland and Antarctic Ice Sheets are losing large amounts of water to the world's oceans. However, estimates of their contribution to sea level rise disagree. We provide a consensus estimate by standardizing existing, and creating new, mass-budget estimates from satellite gravimetry and altimetry and from local glaciological records. In many regions, local measurements are more negative than satellite-based estimates. All regions lost mass during 2003-2009, with the largest losses from Arctic Canada, Alaska, coastal Greenland, the southern Andes, and high-mountain Asia, but there was little loss from glaciers in Antarctica. Over this period, the global mass budget was -259 ± 28 gigatons per year, equivalent to the combined loss from both ice sheets and accounting for 29 ± 13% of the observed sea level rise.
TL;DR: The results reveal a role for selected ESCRT components and accessory proteins in exosome secretion and composition by HeLa-CIITA and highlight biogenetic differences in vesicles secreted by a tumour cell line and primary DCs.
Abstract: Exosomes are extracellular vesicles (EVs) secreted upon fusion of endosomal multivesicular bodies (MVBs) with the plasma membrane. The mechanisms involved in their biogenesis have not yet been fully identified although they could be used to modulate exosome formation and therefore are a promising tool in understanding exosome functions. We have performed an RNA interference screen targeting 23 components of the endosomal sorting complex required for transport (ESCRT) machinery and associated proteins in MHC class II (MHC II)-expressing HeLa-CIITA cells. Silencing of HRS, STAM1 or TSG101 reduced the secretion of EV-associated CD63 and MHC II but each gene altered differently the size and/or protein composition of secreted EVs, as quantified by immuno-electron microscopy. By contrast, depletion of VPS4B augmented this secretion while not altering the features of EVs. For several other ESCRT subunits, it was not possible to draw any conclusions about their involvement in exosome biogenesis from the screen. Interestingly, silencing of ALIX increased MHC II exosomal secretion, as a result of an overall increase in intracellular MHC II protein and mRNA levels. In human dendritic cells (DCs), ALIX depletion also increased MHC II in the cells, but not in the released CD63-positive EVs. Such differences could be attributed to a greater heterogeneity in size, and higher MHC II and lower CD63 levels in vesicles recovered from DCs as compared with HeLa-CIITA. The results reveal a role for selected ESCRT components and accessory proteins in exosome secretion and composition by HeLa-CIITA. They also highlight biogenetic differences in vesicles secreted by a tumour cell line and primary DCs.
TL;DR: This work reports on the three-dimensional vector measurement of SOTs in AlOx/Co/Pt and MgO/CoFeB/Ta trilayers using harmonic analysis of the anomalous and planar Hall effects and demonstrates that heavy metal/ferromagnetic layers allow for two different Sots having odd and even behaviour with respect to magnetization reversal.
Abstract: Spin–orbit torques in heavy metal/ferromagnetic layers have a complex dependence on the magnetization direction. This dependence can be exploited to increase the efficiency of spin–orbit torques.
TL;DR: This review will focus on the nature of the polymers involved in the preparation of targeted nanocarriers, the synthesis methods to achieve the desired macromolecular architecture, the selected coupling strategy, and the choice of the homing molecules (vitamins, hormones, peptides, proteins, etc.), as well as the various strategies to display them at the surface of nanoccarriers.
Abstract: Design and functionalization strategies for multifunctional nanocarriers (e.g., nanoparticles, micelles, polymersomes) based on biodegradable/biocompatible polymers intended to be employed for active targeting and drug delivery are reviewed. This review will focus on the nature of the polymers involved in the preparation of targeted nanocarriers, the synthesis methods to achieve the desired macromolecular architecture, the selected coupling strategy, the choice of the homing molecules (vitamins, hormones, peptides, proteins, etc.), as well as the various strategies to display them at the surface of nanocarriers. The resulting morphologies and the main colloidal features will be given as well as an overview of the biological activities, with a special focus on the main in vivo achievements.