Institution
Carleton University
Education•Ottawa, Ontario, Canada•
About: Carleton University is a education organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 15852 authors who have published 39650 publications receiving 1106610 citations.
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TL;DR: This paper presents a unified framework in which fourteen leading multiscale methods can be represented as special cases and tests the accuracy and efficiency of the fourteen methods on a test problem; the structure and motion of a Lomer dislocation dipole in face-centered cubic aluminum.
Abstract: A partitioned-domain multiscale method is a computational framework in which certain key regions are modeled atomistically while most of the domain is treated with an approximate continuum model (such as finite elements). The goal of such methods is to be able to reproduce the results of a fully atomistic simulation at a reduced computational cost. In recent years, a large number of partitioned-domain methods have been proposed. Theoretically, these methods appear very different to each other making comparison difficult. Surprisingly, it turns out that at the implementation level these methods are in fact very similar. In this paper, we present a unified framework in which fourteen leading multiscale methods can be represented as special cases.We use this common framework as a platform to test the accuracy and efficiency of the fourteen methods on a test problem; the structure and motion of a Lomer dislocation dipole in face-centered cubic aluminum. This problem was carefully selected to be sufficiently simple to be quick to simulate and straightforward to analyze, but not so simple to unwittingly hide differences between methods. The analysis enables us to identify generic features in multiscale methods that correlate with either high or low accuracy and either fast or slow performance.All tests were performed using a single unified computer code in which all fourteen methods are implemented. This code is being made available to the public along with this paper.
381 citations
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University of Bern1, University of Alabama2, Stanford University3, Laurentian University4, Colorado State University5, KLA-Tencor6, University of Massachusetts Amherst7, University of Maryland, College Park8, Carleton University9, Technische Universität München10, Indiana University11, Seoul National University12, University of Chicago13, TRIUMF14, California Institute of Technology15
TL;DR: This work sets a lower limit on the half-life of the neutrinoless double-beta decay T(1/2)(0νββ)(136Xe)>1.6×10(25) yr (90% C.L.), corresponding to effective Majorana masses of less than 140-380 meV, depending on the matrix element calculation.
Abstract: Several properties of neutrinos, such as their absolute mass, their possible Majorana nature or the mechanisms that lead to small neutrino masses, are still unknown. The EXO-200 experiment is trying to answer some of these questions by searching for the hypothetical neutrinoless double beta decay of the isotope 136 Xe. This thesis describes an analysis of two years of detector data, which yields a lower limit on the half-life of neutrinoless double beta decay of 136 Xe of 1.1·10 25 years.
381 citations
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TL;DR: It is indicated that variations in burn severity can influence multiple aspects of forest stand structure, by affecting the density and composition of tree seedlings that establish after fire, and are predicted to be most important in moderately-drained forest stands.
Abstract: Fire, which is the dominant disturbance in the boreal forest, creates substantial heterogeneity in soil burn severity at patch and landscape scales. We present results from five field experiments in Yukon Territory, Canada, and Alaska, USA that document the effects of soil burn severity on the germination and establishment of four common boreal trees: Picea glauca, Picea mariana, Pinus contorta subsp. latifolia, and Populus tremuloides. Burn severity had strong positive effects on seed germination and net seedling establishment after 3 years. Growth of transplanted seedlings was also significantly higher on severely burned soils. Our data and a synthesis of the literature indicated a consistent, steep decline in conifer establishment on organic soils at depths greater than 2.5 cm. A meta-analysis of seedling responses found no difference in the magnitude of severity effects on germination versus net establishment. There were, however, significant differences in establishment but not germination responses among deciduous trees, spruce, and pine, suggesting that small-seeded species experience greater mortality on lightly burned, organic soils than large-seeded species. Together, our analyses indicate that variations in burn severity can influence multiple aspects of forest stand structure, by affecting the density and composition of tree seedlings that establish after fire. These effects are predicted to be most important in moderately-drained forest stands, where a high potential variability in soil burn severity is coupled with strong severity effects on tree recruitment.
379 citations
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TL;DR: The history of the correction for wall attenuation and scatter in an ion chamber is presented as it demonstrates the interplay between a specific problem and the development of tools to solve the problem which in turn leads to applications in other areas.
Abstract: Monte Carlo techniques have become ubiquitous in medical physics over the last 50 years with a doubling of papers on the subject every 5 years between the first PMB paper in 1967 and 2000 when the numbers levelled off. While recognizing the many other roles that Monte Carlo techniques have played in medical physics, this review emphasizes techniques for electron-photon transport simulations. The broad range of codes available is mentioned but there is special emphasis on the EGS4/EGSnrc code system which the author has helped develop for 25 years. The importance of the 1987 Erice Summer School on Monte Carlo techniques is highlighted. As an illustrative example of the role Monte Carlo techniques have played, the history of the correction for wall attenuation and scatter in an ion chamber is presented as it demonstrates the interplay between a specific problem and the development of tools to solve the problem which in turn leads to applications in other areas.
377 citations
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TL;DR: An extensive proteomic survey using affinity-tagged E. coli strains is performed and comprehensive genomic context inferences are generated to derive a high-confidence compendium for virtually the entire proteome consisting of 5,993 putative physical interactions and 74,776 putative functional associations, most of which are novel.
Abstract: One-third of the 4,225 protein-coding genes of Escherichia coli K-12 remain functionally unannotated (orphans). Many map to distant clades such as Archaea, suggesting involvement in basic prokaryotic traits, whereas others appear restricted to E. coli, including pathogenic strains. To elucidate the orphans' biological roles, we performed an extensive proteomic survey using affinity-tagged E. coli strains and generated comprehensive genomic context inferences to derive a high-confidence compendium for virtually the entire proteome consisting of 5,993 putative physical interactions and 74,776 putative functional associations, most of which are novel. Clustering of the respective probabilistic networks revealed putative orphan membership in discrete multiprotein complexes and functional modules together with annotated gene products, whereas a machine-learning strategy based on network integration implicated the orphans in specific biological processes. We provide additional experimental evidence supporting orphan participation in protein synthesis, amino acid metabolism, biofilm formation, motility, and assembly of the bacterial cell envelope. This resource provides a “systems-wide” functional blueprint of a model microbe, with insights into the biological and evolutionary significance of previously uncharacterized proteins.
377 citations
Authors
Showing all 16102 results
Name | H-index | Papers | Citations |
---|---|---|---|
George F. Koob | 171 | 935 | 112521 |
Zhenwei Yang | 150 | 956 | 109344 |
Andrew White | 149 | 1494 | 113874 |
J. S. Keller | 144 | 981 | 98249 |
R. Kowalewski | 143 | 1815 | 135517 |
Manuella Vincter | 131 | 944 | 122603 |
Gabriella Pasztor | 129 | 1401 | 86271 |
Beate Heinemann | 129 | 1085 | 81947 |
Claire Shepherd-Themistocleous | 129 | 1211 | 86741 |
Monica Dunford | 129 | 906 | 77571 |
Dave Charlton | 128 | 1065 | 81042 |
Ryszard Stroynowski | 128 | 1320 | 86236 |
Peter Krieger | 128 | 1171 | 81368 |
Thomas Koffas | 128 | 942 | 76832 |
Aranzazu Ruiz-Martinez | 126 | 783 | 71913 |