184,849 research outputs found
Binary interactions and UV photometry on photometric redshift
Using the Hyperz code (Bolzonella et al. 2000) we present photometric
redshift estimates for a random sample of galaxies selected from the SDSS/DR7
and GALEX/DR4, for which spectroscopic redshifts are also available.
We confirm that the inclusion of ultraviolet photometry improves the accuracy
of photo-zs for those galaxies with g*-r* < 0.7 and z_spec < 0.2. We also
address the problem of how binary interactions can affect photo-z estimates,
and find that their effect is negligible.Comment: 2 pages 1 figure
Response of arum lily calli to culture filtrate of Pectobacterium carotovorum subsp. carotovorum
This report demonstrated that culture filtrate of Pectobacterium carotovorum ssp. carotovorum isolate ZT0505, the pathogen of bacterial soft rot disease of arum lily (Zantedeschia sp.), contained extracellular enzymes and caused arum lily leaf tissue and callus maceration. Arum lily leaf tissue and callus sensitivity to culture filtrate coincided with the host susceptibility to the pathogen. The rates of survival of callus pieces were determined after exposure for various times to culture filtrate. Survival of callus pieces (%) increased with reduction of exposure time from 20 to 14 h and from 14 to 8 h. One out of 30 callus pieces was still viable after 3 cycles of 8 h exposure. Subsequently, the surviving cells in this callus pieces proliferated and differentiated into shoots. Based on this initial work, the callus screening using culture filtrate as selection agent may be useful for in vitro selection of soft rot resistant germplasm in arum lily
Binary Stellar Population Synthesis Model
Using Yunnan evolutionary population synthesis (EPS) models, we present
integrated colours, integrated spectral energy distributions (ISEDs) and
absorption-line indices defined by the Lick Observatory image dissector scanner
(Lick/IDS) system, for an extensive set of instantaneous-burst binary stellar
populations (BSPs) with interactions. By comparing the results for populations
with and without interactions we show that the inclusion of binary interactions
makes the appearance of the population substantially bluer. This effect raises
the derived age and metallicity of the population.
To be used in the studies of modern spectroscopic galaxy surveys at
intermediate/high spectral resolution, we also present intermediate- (3A) and
high-resolution (~0.3A) ISEDs and Lick/IDS absorption-line indices for BSPs. To
directly compare with observations the Lick/IDS absorption indices are also
presented by measuring them directly from the ISEDs.Comment: 2 pages 2 figure
Minimal inference from incomplete 2x2-tables
Estimates based on 2x2 tables of frequencies are widely used in statistical
applications. However, in many cases these tables are incomplete in the sense
that the data required to compute the frequencies for a subset of the cells
defining the table are unavailable. Minimal inference addresses those
situations where this incompleteness leads to target parameters for these
tables that are interval, rather than point, identifiable. In particular, we
develop the concept of corroboration as a measure of the statistical evidence
in the observed data that is not based on likelihoods. The corroboration
function identifies the parameter values that are the hardest to refute, i.e.,
those values which, under repeated sampling, remain interval identified. This
enables us to develop a general approach to inference from incomplete 2x2
tables when the additional assumptions required to support a likelihood-based
approach cannot be sustained based on the data available. This minimal
inference approach then provides a foundation for further analysis that aims at
making sharper inference supported by plausible external beliefs
Emission Patterns and Light Curves of Gamma-Rays in the Pulsar Magnetosphere with a Current-Induced Magnetic Field
We study the emission patterns and light curves of gamma-rays in the pulsar
magnetosphere with a current-induced magnetic field perturbation. Based on the
solution of a static dipole with the magnetic field induced by some currents
(perturbation field), we derive the solutions of a static as well as a retarded
dipole with the perturbation field in the Cartesian coordinates. The static
(retarded) magnetic field can be expressed as the sum of pure static (retarded)
dipolar magnetic field and the static (retarded) perturbation field. We use the
solution of the retarded magnetic field to investigate the influence of the
perturbation field on the emission patterns and light curves, and we apply the
perturbed solutions to calculate the gamma-ray light curves for the case of the
Vela pulsar. We find out that the perturbation field induced by the currents
will change the emission patterns and then light curves of gamma-rays,
especially for a larger perturbation field. Our results indicate that the
perturbation field created by the outward-flowing (inward-flowing) electrons
(positrons) can decrease the rotation effect on the magnetosphere and makes
emission pattern appear to be more smooth relative to that of the pure retarded
dipole, but the perturbation field created by the outward-flowing
(inward-flowing) positrons (electrons) can make the emission pattern less
smooth.Comment: 27 pages, 8 figures, accepted for publication in Ap
Human gait recognition with matrix representation
Human gait is an important biometric feature. It can be perceived from a great distance and has recently attracted greater attention in video-surveillance-related applications, such as closed-circuit television. We explore gait recognition based on a matrix representation in this paper. First, binary silhouettes over one gait cycle are averaged. As a result, each gait video sequence, containing a number of gait cycles, is represented by a series of gray-level averaged images. Then, a matrix-based unsupervised algorithm, namely coupled subspace analysis (CSA), is employed as a preprocessing step to remove noise and retain the most representative information. Finally, a supervised algorithm, namely discriminant analysis with tensor representation, is applied to further improve classification ability. This matrix-based scheme demonstrates a much better gait recognition performance than state-of-the-art algorithms on the standard USF HumanID Gait database
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