16,339 research outputs found
Evershed clouds as precursors of moving magnetic features around sunspots
The relation between the Evershed flow and moving magnetic features (MMFs) is
studied using high-cadence, simultaneous spectropolarimetric measurements of a
sunspot in visible (630.2 nm) and near-infrared (1565 nm) lines. Doppler
velocities, magnetograms, and total linear polarization maps are calculated
from the observed Stokes profiles. We follow the temporal evolution of two
Evershed clouds that move radially outward along the same penumbral filament.
Eventually, the clouds cross the visible border of the spot and enter the moat
region, where they become MMFs. The flux patch farther from the sunspot has the
same polarity of the spot, while the MMF closer to it has opposite polarity and
exhibits abnormal circular polarization profiles. Our results provide strong
evidence that at least some MMFs are the continuation of the penumbral Evershed
flow into the moat. This, in turn, suggests that MMFs are magnetically
connected to sunspots.Comment: To appear in ApJ Letters, Vol 649, 2006 September 20 issu
A spatially-structured PCG method for content diversity in a Physics-based simulation game
This paper presents a spatially-structured evolutionary algorithm (EA) to procedurally generate game maps of di ferent levels of di ficulty to be solved, in Gravityvolve!, a physics-based simulation videogame that we have implemented and which is inspired by the n-
body problem, a classical problem in the fi eld of physics and mathematics. The proposal consists of a steady-state EA whose population is partitioned into three groups according to the di ficulty of the generated content (hard, medium or easy) which can be easily adapted to handle the automatic creation of content of diverse nature in other games. In addition, we present three fitness functions, based on multiple criteria (i.e:, intersections, gravitational acceleration and simulations), that were used experimentally to conduct the search process for creating a database of
maps with di ferent di ficulty in Gravityvolve!.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Datasets for transcriptomics, q-proteomics and phenotype microarrays of polyphosphate metabolism mutants from Escherichia coli
Indexación: Scopus.Author acknowledges Fondecyt Grants 1120209, 1121170 and Anillo ACT-1107Here, we provide the dataset associated with our research article on the polyphosphate metabolism entitled, “Multi-level evaluation of Escherichia coli polyphosphate related mutants using global transcriptomic, proteomic and phenomic analyses”. By integrating different omics levels (transcriptome, proteome and phenome), we were able to study Escherichia coli polyphosphate mutant strains (Δppk1, Δppx, and Δppk1-ppx). We have compiled here all datasets from DNA microarrys, q-proteomic (Isotope-Coded Protein Labeling, ICPL) and phenomic (Phenotype microarray) raw data we have obtained in all polyP metabolism mutants.http://www.sciencedirect.com/science/article/pii/S2352340917300860?via%3Dihu
Manejo y eficiencia en la pesquería del camarón del Alto Golfo de California
Actualmente la pesquería del camarón en el Alto Golfo de California genera preocupaciones referentes a su impacto sobre el medio ambiente, su viabilidad biológica y rentabilidad. Con el propósito de entender el manejo de esta pesquería y su productividad física, hemos examinado el comportamiento productivo de los barcos camaroneros de San Felipe, B.C. durante el periodo 1990-1993. Para ello usamos una función de producción frontera, flexible y no restringida, respecto a la cual estimamos la eficiencia técnica de cada una de las naves observadas. Nuestros resultados indican que la eficiencia promedio de la flota observada es del 80%, un valor de eficiencia cercano al mejor uso de la tecnología productiva y de los factores de la producción. Las naves más viejas resultaron menos eficientes, un resultado esperado; sin embargo, el tamaño de la cooperativa y calidad de su administración afectó positivamente los valores de eficiencia de las naves asociadas enmascarando con ello el efecto antes mencionado y favoreciendo el desarrollo de economías de escala. Los resultados indican también que el conocimiento acumulativo sobre la pesquería del camarón entre los productores es una variable importante, en términos de su efecto sobre la eficiencia productiva de las naves, mientras que la innovación tecnológica ha sido escasa, excepto por los excluidores de tortugas incorporados a su tecnología de captura durante 1996. Concluimos de nuestro análisis que la divulgación del conocimiento sobre la pesquería, como una variable social de cambio desincorporada a la función de producción, y el fortalecimiento de la calidad de los servicios administrativos, son dos aspectos fundamentales a promover para el desarrollo de esta pesquería. También argumentamos que la semejanza tecnológica y operativa entre ambas flotas, la de San Felipe, B.C. y el resto de la flota del camarón que pesca en el Golfo de California permite que nuestro análisis ofrezca un marco de referencia informático básico y útil al ordenamiento y desarrollo futuro de esta última
Excitations in the quantum paramagnetic phase of the quasi-one-dimensional Ising magnet CoNbO in a transverse field: Geometric frustration and quantum renormalization effects
The quasi-one-dimensional (1D) Ising ferromagnet CoNbO has recently
been driven via applied transverse magnetic fields through a continuous quantum
phase transition from spontaneous magnetic order to a quantum paramagnet, and
dramatic changes were observed in the spin dynamics, characteristic of weakly
perturbed 1D Ising quantum criticality. We report here extensive single-crystal
inelastic neutron scattering measurements of the magnetic excitations
throughout the three-dimensional (3D) Brillouin zone in the quantum
paramagnetic phase just above the critical field to characterize the effects of
the finite interchain couplings. In this phase, we observe that excitations
have a sharp, resolution-limited line shape at low energies and over most of
the dispersion bandwidth, as expected for spin-flip quasiparticles. We map the
full bandwidth along the strongly dispersive chain direction and resolve clear
modulations of the dispersions in the plane normal to the chains,
characteristic of frustrated interchain couplings in an antiferromagnetic
isosceles triangular lattice. The dispersions can be well parametrized using a
linear spin-wave model that includes interchain couplings and further neighbor
exchanges. The observed dispersion bandwidth along the chain direction is
smaller than that predicted by a linear spin-wave model using exchange values
determined at zero field, and this effect is attributed to quantum
renormalization of the dispersion beyond the spin-wave approximation in fields
slightly above the critical field, where quantum fluctuations are still
significant.Comment: 11 pages, 6 figures. Updated references. Minor changes to text and
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