1,008 research outputs found

    Polar-bulge galaxies

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    Based on SDSS data, we have selected a sample of nine edge-on spiral galaxies with bulges whose major axes show a high inclination to the disk plane. Such objects are called polar-bulge galaxies. They are similar in their morphology to polar-ring galaxies, but the central objects in them have small size and low luminosity. We have performed a photometric analysis of the galaxies in the g and r bands and determined the main characteristics of their bulges and disks. We show that the disks of such galaxies are typical for the disks of spiral galaxies of late morphological types. The integrated characteristics of their bulges are similar to the parameters of normal bulges. The stellar disks of polar-bulge galaxies often show large-scale warps, which can be explained by their interaction with neighboring galaxies or external accretion from outside.Comment: 8 pages, 3 figure

    Edge-on galaxies in the HST COSMOS field: the evolution of stellar discs up to z∼\sim0.5

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    We present a sample of 950 edge-on spiral galaxies found with the use of an artificial neural network in the Hubble Space Telescope COSMOS field. This is currently the largest sample of distant edge-on galaxies. For all galaxies we analyzed the 2D brightness distributions in the F814W filter and measured the radial and vertical exponential scales (hh and hzh_z correspondingly) of the brightness distribution. By comparing the characteristics of distant galaxies with those of nearby objects, we conclude that thin stellar discs with h/hz≥10h/h_z \geq 10 at z≈0.5z \approx 0.5 should be rarer than today. Both exponential scales of the stellar disc show evidence of luminosity-dependent evolution: in faint galaxies the hh and hzh_z values do not change with zz, in bright (and massive) spiral galaxies both scales, on average, grow towards our epoch.Comment: 5 pages, accepted for publication in MNRAS Letter

    Group-level Emotion Recognition using Transfer Learning from Face Identification

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    In this paper, we describe our algorithmic approach, which was used for submissions in the fifth Emotion Recognition in the Wild (EmotiW 2017) group-level emotion recognition sub-challenge. We extracted feature vectors of detected faces using the Convolutional Neural Network trained for face identification task, rather than traditional pre-training on emotion recognition problems. In the final pipeline an ensemble of Random Forest classifiers was learned to predict emotion score using available training set. In case when the faces have not been detected, one member of our ensemble extracts features from the whole image. During our experimental study, the proposed approach showed the lowest error rate when compared to other explored techniques. In particular, we achieved 75.4% accuracy on the validation data, which is 20% higher than the handcrafted feature-based baseline. The source code using Keras framework is publicly available.Comment: 5 pages, 3 figures, accepted for publication at ICMI17 (EmotiW Grand Challenge

    Strong nonlinear optical response of graphene flakes measured by four-wave mixing

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    We present the first experimental investigation of nonlinear optical properties of graphene flakes. We find that at near infrared frequencies a graphene monolayer exhibits a remarkably high third-order optical nonlinearity which is practically independent of the wavelengths of incident light. The nonlinear optical response can be utilized for imaging purposes, with image contrasts of graphene which are orders of magnitude higher than those obtained using linear microscopy.Comment: 4 pages, 5 figure

    IMMUNOLOGICAL MONITORING OF THE INFLUENZA VIRUS A SUBTYPE H5 AND H7 DISTRIBUTION IN SOUTH OF CENTRAL SIBERIA

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    For the first time in the south of the Central Siberia carried out large-scale study of wild and synanthropic birds for the presence of influenza A viruses. Along with the traditional methods of laboratory study of pathogens in Merskey's reaction and. PCR carried out ornithological research in areas of high concentrations of birds and. flyways. Also studied the long-term dynamics of isolation of positive samples containing specific antibody to influenza virus A subtypes H5 and. H7 and. genomic RNA of these subtypes. It was found that infection and. reinfection. of birds by avian influenza doesn't take place only during the wintering grounds, but also the breeding season in the water keepings of the south of the Central Siberia. Chicks are actively involved in the epizootic process in July, when transovarialy transmitted maternal antibodies disappear. Because of the peak interval of positive samples selection in Merskey's reaction and. PCR is 3 years, it is possible to organize an immunological monitoring followed by preventive programs development of birds deaths
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