770 research outputs found

    Producción científica de Cuba: una perspectiva desde la obra de dos mujeres académicas

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    Aimed at studying the visibility of the Cuban scientific production, the publications of both, merit and number academic members of the Biomedical Section and of the Natural and Exact Sciences Section of the Cuban Academy of Science, processed in the Scopus database, were identified. Two women, doctors Rosa María Más Ferreiro and María Guadalupe Guzmán, were not only the most productive ones, but also their works had the best impact. These findings corroborated the role played by women in the Cuban science

    Discovery of a massive supercluster system at z∼0.47z \sim 0.47

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    Superclusters are the largest relatively isolated systems in the cosmic web. Using the SDSS BOSS survey we search for the largest superclusters in the redshift range 0.43<z<0.710.43<z<0.71. We generate a luminosity-density field smoothed over 8h−1Mpc8 h^{-1}\mathrm{Mpc} to detect the large-scale over-density regions. Each individual over-density region is defined as single supercluster in the survey. We define the superclusters in the way that they are comparable with the superclusters found in the SDSS main survey. We found a system we call the BOSS Great Wall (BGW), which consists of two walls with diameters 186 and 173 h−1h^{-1}Mpc, and two other major superclusters with diameters of 64 and 91 h−1h^{-1}Mpc. As a whole, this system consists of 830 galaxies with the mean redshift 0.47. We estimate the total mass to be approximately 2×1017h−1M⊙2\times10^{17}h^{-1}M_\odot. The morphology of the superclusters in the BGW system is similar to the morphology of the superclusters in the Sloan Great Wall region. The BGW is one of the most extended and massive system of superclusters yet found in the Universe.Comment: 4 pages, accepted as a letter in A&

    How much dark matter is there inside early-type galaxies?

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    We study the luminous mass as a function of the dynamical mass inside the effective radius (r_e) of early-type galaxies (ETGs) to search for differences between these masses. We assume Newtonian dynamics and that any difference between these masses is due to the presence of dark matter. We use several samples of ETGs -ranging from 19 000 to 98 000 objects- from the ninth data release of the Sloan Digital Sky Survey. We perform Monte Carlo (MC) simulations of galaxy samples and compare them with real samples. The main results are: i) MC simulations show that the distribution of the dynamical vs. luminous mass depends on the mass range where the ETGs are distributed (geometric effect). This dependence is caused by selection effects and intrinsic properties of the ETGs. ii) The amount of dark matter inside r_e is approximately 7% +- 22%. iii) This amount of dark matter is lower than the minimum estimate (10%) found in the literature and four times lower than the average (30%) of literature estimates. However, if we consider the associated error, our estimate is of the order of the literature average.Comment: 24 pages, 12 figures. MNRAS accepte

    Las meningoencefalitis bacterianas: un reto para la salud infantil

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    RF/SS system for wireless local loop

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    In this communication we deal with the use of direct sequence spread spectrum tecllniques for radio transmission in the local loop. We present a direct sequence spread-spectrum system that is being developed to transmit signals from ISDN-U [I] interfaces between subscriber premises and the local station. Some attention is' devoted to tlie IF and RF blocks

    A semi-analytical perspective on massive galaxies at z∼0.55z\sim0.55

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    The most massive and luminous galaxies in the Universe serve as powerful probes to study the formation of structure, the assembly of mass, and cosmology. However, their detailed formation and evolution is still barely understood. Here we extract a sample of massive mock galaxies from the semi-analytical model of galaxy formation (SAM) GALACTICUS from the MultiDark-Galaxies, by replicating the CMASS photometric selection from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). The comparison of the GALACTICUS CMASS-mock with BOSS-CMASS data allows us to explore different aspects of the massive galaxy population at 0.5<z<0.60.5<z<0.6, including the galaxy-halo connection and the galaxy clustering. We find good agreement between our modelled galaxies and observations regarding the galaxy-halo connection, but our CMASS-mock over-estimates the clustering amplitude of the 2-point correlation function, due to a smaller number density compared to BOSS, a lack of blue objects, and a small intrinsic scatter in stellar mass at fixed halo mass of <0.1<0.1 dex. To alleviate this problem, we construct an alternative mock catalogue mimicking the CMASS colour-magnitude distribution by randomly down-sampling the SAM catalogue. This CMASS-mock reproduces the clustering of CMASS galaxies within 1σ\sigma and shows some environmental dependency of star formation properties that could be connected to the quenching of star formation and the assembly bias.Comment: 15 pages, 10 figures, 2 tables, submitted to MNRA

    The GAN that warped: semantic attribute editing with unpaired data

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    Deep neural networks have recently been used to edit images with great success, in particular for faces. However, they are often limited to only being able to work at a restricted range of resolutions. Many methods are so flexible that face edits can often result in an unwanted loss of identity. This work proposes to learn how to perform semantic image edits through the application of smooth warp fields. Previous approaches that attempted to use warping for semantic edits required paired data, i.e. example images of the same subject with different semantic attributes. In contrast, we employ recent advances in Generative Adversarial Networks that allow our model to be trained with unpaired data. We demonstrate face editing at very high resolutions (4k images) with a single forward pass of a deep network at a lower resolution. We also show that our edits are substantially better at preserving the subject's identity. The robustness of our approach is demonstrated by showing plausible image editing results on the Cub200 birds dataset. To our knowledge this has not been previously accomplished, due the challenging nature of the dataset
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