Search Results - (Author, Cooperation:S. W. Smith)

2015-09-10

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Alleles ; Alternative Splicing/genetics ; Arecaceae/*genetics/metabolism ; *DNA Methylation ; Epigenesis, Genetic/*genetics ; *Epigenomics ; Fruit/genetics ; Genes, Homeobox/genetics ; Genetic Association Studies ; Genome, Plant/*genetics ; Introns/genetics ; Molecular Sequence Data ; *Phenotype ; Plant Oils/analysis/metabolism ; RNA Splice Sites/genetics ; RNA, Small Interfering/genetics ; Retroelements/*genetics

2013-07-26

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Arabidopsis Proteins/genetics ; Arecaceae/*genetics/*metabolism ; Chromosome Mapping ; Gene Expression Profiling ; Gene Expression Regulation, Plant ; Genes, Plant/*genetics ; Genetic Variation ; Homozygote ; MADS Domain Proteins/genetics ; Molecular Sequence Data ; Mutation ; *Plant Oils ; Sequence Alignment

2013-07-26

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Arecaceae/*classification/*genetics ; Carbohydrate Metabolism/genetics ; Chromosomes, Plant/genetics ; Genome, Plant/*genetics ; Lipid Metabolism/genetics ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The implication of this relationship with regard to the penetration of liquid metals into compacted sand, to which they refer in the latter part of their communication, has, I think, some analogy to the behaviour of metals on the surfaces of cupels when undergoing cupellation in the process by ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] THE interesting letter appearing under the above title in the issue of NATURE for February 15 reminds me of a different, but equally simple, method of producing the same phenomenon, described in the Proceedings of the Physical Society, vol. xxviii., p. 59, 1915. There, in order to avoid ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] IN a recent communication1, Prof. E. A. Owen advances a theory to account for the Widmanstätten figures in meteorites. He suggests that the meteorite is heated to a high temperature in its passage through the earth's atmosphere and is then suddenly, cooled on coming to rest in ...

Electronic Resource

1420-9136

Key words: Regional seismicity, seismic cycle, cellular automation, critical point, fractals.

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract —A cellular automaton is used to study the relation between the structure of a regional fault network and the temporal and spatial patterns of regional seismicity. Automata in which the cell sizes form discrete fractal hierarchies are compared with those having a uniform cell size. Conservative models in which all the stress is transferred at each step of a cascade are compared with nonconservative ("lossy") models in which a specified fraction of the stress energy is lost from each step. Particular attention is given to the behavior of the system as it is driven toward the critical state by uniform external loading. All automata exhibit a scaling region at times close to the critical state in which the events become larger and energy release increases as a power-law of the time to the critical state. For the hierarchical fractal automata, this power-law behavior is often modulated by fluctuations that are periodic in the logarithm of the time to criticality. These fluctuations are enhanced in the nonconservative models, but are not robust. The degree to which they develop appears to depend on the particular distribution of stresses in the larger cells which varies from cycle to cycle. Once the critical state is reached, seismicity in the uniform conservative automaton remains random in time, space, and magnitude. Large events do not significantly perturb the stress distribution in the system. However, large events in the nonconservative uniform automaton and in the fractal systems produce large stress perturbations that move the system out of the critical state. The result is a seismic cycle in which a large event is followed by a shadow period of quiescence and then a new approach back toward the critical state. This seismic cycle does not depend on the fractal structure, but is a direct consequence of large-scale heterogeneity of these systems in which the size of the largest cell (or the size of the largest nonconservative event) is a significant fraction of the size of the network. In essence, seismic cycles in these models are boundary effects. The largest events tend to cluster in time and the rate of small events remains relatively constant throughout a cycle in agreement with observed seismicity.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] THE very interesting article by Dr. L. J. Spencer on “Meteorite Craters”, in NATURE of May 28, suggests a possible explanation of the fact that, while the bedding of the surrounding country may be horizontal, the strata exposed in the inner walls of the crater usually dip radially outwards from ...

Electronic Resource

1573-2878

Structural identification ; model adjustment ; optimal matrix approximation ; least-change secant updates

Springer Online Journal Archives 1860-2000

Mathematics

Abstract Problems of model correlation and system identification are central in the design, analysis, and control of large space structures. Of the numerous methods that have been proposed, many are based on finding minimal adjustments to a model matrix sufficient to introduce some desirable quality into that matrix. In this work, several of these methods are reviewed, placed in a modern framework, and linked to other previously known ideas in computational linear algebra and optimization. This new framework provides a point of departure for a number of new methods which are introduced here. Significant among these is a method for stiffness matrix adjustment which preserves the sparsity pattern of an original matrix, requires comparatively modest computational resources, and allows robust handling of noisy modal data. Numerical examples are included to illustrate the methods presented herein.

Electronic Resource