Institution
ETH Zurich
Education•Zurich, Switzerland•
About: ETH Zurich is a education organization based out in Zurich, Switzerland. It is known for research contribution in the topics: Population & Computer science. The organization has 48393 authors who have published 122408 publications receiving 5111383 citations. The organization is also known as: Swiss Federal Institute of Technology in Zurich & Eidgenössische Technische Hochschule Zürich.
Topics: Population, Computer science, Catalysis, Context (language use), Laser
Papers published on a yearly basis
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TL;DR: In this article, a cosmological N-body/smooth particle hydrodynamic simulation of extreme dynamic range in which a close analog of a Milky Way disk galaxy arises naturally is presented.
Abstract: Simulations of the formation of late-type spiral galaxies in a cold dark matter ({Lambda}CDM) universe have traditionally failed to yield realistic candidates. Here we report a new cosmological N-body/smooth particle hydrodynamic simulation of extreme dynamic range in which a close analog of a Milky Way disk galaxy arises naturally. Named 'Eris', the simulation follows the assembly of a galaxy halo of mass M{sub vir} = 7.9 Multiplication-Sign 10{sup 11} M{sub Sun} with a total of N = 18.6 million particles (gas + dark matter + stars) within the final virial radius, and a force resolution of 120 pc. It includes radiative cooling, heating from a cosmic UV field and supernova explosions (blastwave feedback), a star formation recipe based on a high gas density threshold (n{sub SF} = 5 atoms cm{sup -3} rather than the canonical n{sub SF} = 0.1 atoms cm{sup -3}), and neglects any feedback from an active galactic nucleus. Artificial images are generated to correctly compare simulations with observations. At the present epoch, the simulated galaxy has an extended rotationally supported disk with a radial scale length R{sub d} = 2.5 kpc, a gently falling rotation curve with circular velocity at 2.2 disk scale lengths of V{sub 2.2}more » = 214 km s{sup -1}, an i-band bulge-to-disk ratio B/D = 0.35, and a baryonic mass fraction within the virial radius that is 30% below the cosmic value. The disk is thin, has a typical H I-to-stellar mass ratio, is forming stars in the region of the {Sigma}{sub SFR}-{Sigma}{sub HI} plane occupied by spiral galaxies, and falls on the photometric Tully-Fisher and the stellar-mass-halo-virial-mass relations. Hot (T > 3 Multiplication-Sign 10{sup 5} K) X-ray luminous halo gas makes up only 26% of the universal baryon fraction and follows a 'flattened' density profile {proportional_to}r{sup -1.13} out to r = 100 kpc. Eris appears then to be the first cosmological hydrodynamic simulation in which the galaxy structural properties, the mass budget in the various components, and the scaling relations between mass and luminosity are all consistent with a host of observational constraints. A twin simulation with a low star formation density threshold results in a galaxy with a more massive bulge and a much steeper rotation curve, as in previously published work. A high star formation threshold appears therefore key in obtaining realistic late-type galaxies, as it enables the development of an inhomogeneous interstellar medium where star formation and heating by supernovae occur in a clustered fashion. The resulting outflows at high redshifts reduce the baryonic content of galaxies and preferentially remove low-angular-momentum gas, decreasing the mass of the bulge component. Simulations of even higher resolution that follow the assembly of galaxies with different merger histories shall be used to verify our results.« less
583 citations
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University of Cambridge1, University College London2, McGill University3, University of Leicester4, University of Bristol5, University of Copenhagen6, University of London7, Copenhagen University Hospital8, University of Queensland9, University of Washington10, University of Vermont11, Sir Charles Gairdner Hospital12, University of Western Australia13, Ontario Institute for Cancer Research14, University of Würzburg15, ETH Zurich16, University of Edinburgh17, University of Warwick18, Utrecht University19, National Heart Foundation of Australia20, Boston University21, University of Kiel22, University of Lübeck23, University Hospital Regensburg24, King's College London25, Mario Negri Institute for Pharmacological Research26, Wake Forest University27, Karolinska Institutet28, University of Leeds29, Harvard University30, Group Health Cooperative31, McMaster University32, University of Oxford33, University of Glasgow34, Imperial College London35, Medical University of Graz36, University of Ulm37, Goethe University Frankfurt38, Lund University39, Helmholtz Zentrum München40, Robert Koch Institute41, Ludwig Maximilian University of Munich42, Umeå University43, University of Pennsylvania44, Johns Hopkins University45, Clinical Trial Service Unit46, Aga Khan University Hospital47, Robertson Centre for Biostatistics48, Tufts University49, University of Bonn50, Erasmus University Rotterdam51, Karolinska University Hospital52, University of Groningen53, Northwestern University54, University of California, Los Angeles55, Glasgow Royal Infirmary56, Glasgow Clinical Research Facility57
TL;DR: Human genetic data indicate that C reactive protein concentration itself is unlikely to be even a modest causal factor in coronary heart disease.
Abstract: Objective To use genetic variants as unconfounded proxies of C reactive protein concentration to study its causal role in coronary heart disease. Design Mendelian randomisation meta-analysis of ind ...
583 citations
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TL;DR: In this article, the phyllosphere and rhizosphere microbiota of rice cultivars were characterized using a metaproteogenomic approach to get insight into the physiology of the bacteria and archaea that live in association with rice.
Abstract: The above- and below-ground parts of rice plants create specific habitats for various microorganisms. In this study, we characterized the phyllosphere and rhizosphere microbiota of rice cultivars using a metaproteogenomic approach to get insight into the physiology of the bacteria and archaea that live in association with rice. The metaproteomic datasets gave rise to a total of about 4600 identified proteins and indicated the presence of one-carbon conversion processes in the rhizosphere as well as in the phyllosphere. Proteins involved in methanogenesis and methanotrophy were found in the rhizosphere, whereas methanol-based methylotrophy linked to the genus Methylobacterium dominated within the protein repertoire of the phyllosphere microbiota. Further, physiological traits of differential importance in phyllosphere versus rhizosphere bacteria included transport processes and stress responses, which were more conspicuous in the phyllosphere samples. In contrast, dinitrogenase reductase was exclusively identified in the rhizosphere, despite the presence of nifH genes also in diverse phyllosphere bacteria.
582 citations
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TL;DR: This paper studies a D-PSGD algorithm and provides the first theoretical analysis that indicates a regime in which decentralized algorithms might outperform centralized algorithms for distributed stochastic gradient descent.
Abstract: Most distributed machine learning systems nowadays, including TensorFlow and CNTK, are built in a centralized fashion. One bottleneck of centralized algorithms lies on high communication cost on the central node. Motivated by this, we ask, can decentralized algorithms be faster than its centralized counterpart?
Although decentralized PSGD (D-PSGD) algorithms have been studied by the control community, existing analysis and theory do not show any advantage over centralized PSGD (C-PSGD) algorithms, simply assuming the application scenario where only the decentralized network is available. In this paper, we study a D-PSGD algorithm and provide the first theoretical analysis that indicates a regime in which decentralized algorithms might outperform centralized algorithms for distributed stochastic gradient descent. This is because D-PSGD has comparable total computational complexities to C-PSGD but requires much less communication cost on the busiest node. We further conduct an empirical study to validate our theoretical analysis across multiple frameworks (CNTK and Torch), different network configurations, and computation platforms up to 112 GPUs. On network configurations with low bandwidth or high latency, D-PSGD can be up to one order of magnitude faster than its well-optimized centralized counterparts.
582 citations
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TL;DR: The fundamental physical, chemical and ecological features of the phycosphere are reviewed, with the goal of delivering a fresh perspective on the nature and importance of phytoplankton–bacteria interactions in aquatic ecosystems.
Abstract: By controlling nutrient cycling and biomass production at the base of the food web, interactions between phytoplankton and bacteria represent a fundamental ecological relationship in aquatic environments Although typically studied over large spatiotemporal scales, emerging evidence indicates that this relationship is often governed by microscale interactions played out within the region immediately surrounding individual phytoplankton cells This microenvironment, known as the phycosphere, is the planktonic analogue of the rhizosphere in plants The exchange of metabolites and infochemicals at this interface governs phytoplankton-bacteria relationships, which span mutualism, commensalism, antagonism, parasitism and competition The importance of the phycosphere has been postulated for four decades, yet only recently have new technological and conceptual frameworks made it possible to start teasing apart the complex nature of this unique microbial habitat It has subsequently become apparent that the chemical exchanges and ecological interactions between phytoplankton and bacteria are far more sophisticated than previously thought and often require close proximity of the two partners, which is facilitated by bacterial colonization of the phycosphere It is also becoming increasingly clear that while interactions taking place within the phycosphere occur at the scale of individual microorganisms, they exert an ecosystem-scale influence on fundamental processes including nutrient provision and regeneration, primary production, toxin biosynthesis and biogeochemical cycling Here we review the fundamental physical, chemical and ecological features of the phycosphere, with the goal of delivering a fresh perspective on the nature and importance of phytoplankton-bacteria interactions in aquatic ecosystems
582 citations
Authors
Showing all 49062 results
Name | H-index | Papers | Citations |
---|---|---|---|
Ralph Weissleder | 184 | 1160 | 142508 |
Ruedi Aebersold | 182 | 879 | 141881 |
David L. Kaplan | 177 | 1944 | 146082 |
Andrea Bocci | 172 | 2402 | 176461 |
Richard H. Friend | 169 | 1182 | 140032 |
Lorenzo Bianchini | 152 | 1516 | 106970 |
David D'Enterria | 150 | 1592 | 116210 |
Andreas Pfeiffer | 149 | 1756 | 131080 |
Bernhard Schölkopf | 148 | 1092 | 149492 |
Martin J. Blaser | 147 | 820 | 104104 |
Sebastian Thrun | 146 | 434 | 98124 |
Antonio Lanzavecchia | 145 | 408 | 100065 |
Christoph Grab | 144 | 1359 | 144174 |
Kurt Wüthrich | 143 | 739 | 103253 |
Maurizio Pierini | 143 | 1782 | 104406 |