519 research outputs found

    Are Altmetrics-traditional systems correlations affected by the journals' social media marketing plan? The journal Comunicar

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    En este estudio se analizan las correlaciones entre los datos aportados por los sistemas de citas tradicionales y las altmétricas de los artículos publicados durante cinco años en la revista Comunicar, que destaca sobre las demás de su área por su avanzado plan de marketing en medios sociales. Además, se presentan los indicadores que ofrecen datos altmétricos y se lleva a cabo una revisión bibliográfica sobre las publicaciones que han tratado el tema de las correlaciones, destacando relaciones débiles entre métricas tradicionales y altmétricas. Del estudio de correlaciones sobre los datos de la revista, se confirman las débiles relaciones entre los tipos de métricas y se concluye que son significativas para evaluar el nivel de atención que reciben las publicaciones en distintos ámbitos. Como recomendación a los investigadores y editores se destaca la importancia de utilizar los medios sociales, en especial Mendeley y Twitter, para dar visibilidad y difundir la producción científica.This study analyses the correlations between data provided by the traditional citation systems on one hand and altmetrics on the other hand, related to the articles published in the journal Comunicar during five years. This journal stands out among the others in its field due to its advanced social media marketing plan. First, a presentation of the most representative aspects of altmetrics is given, according to published studies. Next, a bibliographic review is carried out on the publications dealing with the subject of the correlations and that emphasize the low correlation between citations and altmetrics. With the aim of helping researchers to understand what they involved and how they are used for their own benefit, this review is followed by a cross-metric validation study of the articles that concludes that altmetrics do not measure the authors' scientific impact, but they are significant in assessing the level of attention received by their publications in different fields and indicate the interest and the importance of using social media, especially Mendeley and Twitter, to give visibility and disseminate their scientific outputs

    Taxonomic identification of Amazonian tree crowns from aerial photography

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    Question: To what extent can aerial photography be used for taxonomic identification of Amazonian tree crowns? Objective: To investigate whether a combination of dichotomous keys and a web-based interface is a suitable approach to identify tree crowns. Location: The fieldwork was conducted at Tiputini Biodiversity Station located in the Amazon, eastern Ecuador. Methods: High-resolution imagery was taken from an airplane flying at a low altitude (600 m) above the ground. Imagery of the observable upper layer of the tree crowns was used for the analysis. Dichotomous identification keys for different types of crowns were produced and tested. The identification keys were designed to be web-based interactive, using Google Earth as the main online platform. The taxa analysed were Iriartea, Astrocaryum, Inga, Parkia, Cecropia, Pourouma, Guarea, Otoba, Lauraceae and Pouteria. Results: This paper demonstrates that a combination of photo-imagery, dichotomous keys and a web-based interface can be useful for the taxonomic identification of Amazonian trees based on their crown characteristics. The keys tested with an overall identification accuracy of over 50% for five of the ten taxa with three of them showing accuracy greater than 70% (Iriartea, Astrocaryum and Cecropia). Conclusions: The application of dichotomous keys and a web-based interface provides a new methodological approach for taxonomic identification of various Amazonian tree crowns. Overall, the study showed that crowns with a medium-rough texture are less reliably identified than crowns with smoother or well-defined surfaces

    Polar Field Reversal Observations with Hinode

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    We have been monitoring yearly variation in the Sun's polar magnetic fields with the Solar Optical Telescope aboard {\it Hinode} to record their evolution and expected reversal near the solar maximum. All magnetic patches in the magnetic flux maps are automatically identified to obtain the number density and magnetic flux density as a function of th total magnetic flux per patch. The detected magnetic flux per patch ranges over four orders of magnitude (101510^{15} -- 102010^{20} Mx). The higher end of the magnetic flux in the polar regions is about one order of magnitude larger than that of the quiet Sun, and nearly that of pores. Almost all large patches (1018 \geq 10^{18} Mx) have the same polarity, while smaller patches have a fair balance of both polarities. The polarity of the polar region as a whole is consequently determined only by the large magnetic concentrations. A clear decrease in the net flux of the polar region is detected in the slow rising phase of the current solar cycle. The decrease is more rapid in the north polar region than in the south. The decrease in the net flux is caused by a decrease in the number and size of the large flux concentrations as well as the appearance of patches with opposite polarity at lower latitudes. In contrast, we do not see temporal change in the magnetic flux associated with the smaller patches (<1018 < 10^{18} Mx) and that of the horizontal magnetic fields during the years 2008--2012.Comment: 21 pages, 7 figures. Accepted for publication in Ap

    Receptor Binding Domain (RBD) Structural Susceptibility in the SARS-CoV-2 Virus Spike Protein Exposed to a Pulsed Electric Field

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    SARS-CoV-2 is responsible for causing the Coronavirus disease 2019 (COVID-19) pandemic, which has so far infected more than thirty million people and caused almost a million deaths. For this reason, it has been a priority to stop the transmission of the outbreak through preventive measures, such as surface disinfection, and to establish bases for the design of an effective disinfection technique without chemical components. In this study, we performed in silico analysis to identify the conformational alterations of the SARS-CoV-2 Spike Receptor Binding Domain (RBD) caused by the effect of a pulsed electric field at two different intensities. We found that both stimuli, especially the one with the highest angular frequency and amplitude, modified the electrical charge distribution in the RBD surface and the number of hydrogen bonds. Moreover, the secondary structure was significantly affected, with a decrease of the structured regions, particularly the regions with residues involved in recognizing and interacting with the receptor ACE2. Since many regions suffered conformational changes, we calculated RMSF and ΔRMSF to identify the regions and residues with larger fluctuations and higher flexibility. We found that regions conformed by 353-372, 453-464, and 470-490 amino acid residues fluctuate the most, where the first is considered a therapeutic target, and the last has alreadybeen characterized for its flexibility. Our results indicate that a pulsed electric field can cause loss of stability in the Spike-RBD, and we were able to identify the vulnerable sites to be used as a starting point for the development of viral inhibition or inactivation mechanisms

    Unraveling complex relations between forest-cover change and conflicts through spatial and relational analyses

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    Unidad de excelencia María de Maeztu MdM-2015-0552Despite the increasing prevalence of forest-cover change and conflicts, most studies have been unable to unravel the complex relations between the two processes. We attribute this failure to methodological limitations. We put forward an alternative approach that combines different datasets (remote sensing, GIS, local narratives, official censuses, newspaper articles), methods (spatial and relational analyses), and scales (subregions, economic sectors, land-based activities) to create a robust explanation of the relations between different intensities of forest-cover change and conflict in the Meseta Purépecha region, central Mexico. This is an important forest region, inhabited by indigenous and mestizo peasants; it has a worldwide reputation for community forestry and is also the epicenter of international avocado production. Forest-cover change is intense and there are recurrent episodes of conflict. We clustered communities in three subregions according to their patterns of forest-cover change. We analyzed the spatial patterns of forest-cover change and conflicts and we characterized the structure and function of the different economic sectors to unravel the nonlinear, interdependent (and sometimes contradictory) relations among these processes. We found that avocado production has differentially shaped the composition and working of society within each subregion, leading to three diverging patterns. Avocado production has provoked conflicts over landownership and over illegal logging in nearby areas. In some areas, a low incidence of conflicts over forest clearance might be explained by high profits, coercion, and violence. We suggest that, by combining spatial and relational analyses, we can integrate and check the congruence of nonequivalent representations from quantitative sources and observant participation at different scales and explain the heterogeneity that processes display across space. Our methodological approach can thus improve our understanding of similar and other complex and uncertain environmental problems elsewhere, especially when accurate or appropriate data are missing

    Emergence of small-scale magnetic loops through the quiet solar atmosphere

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    We investigate the emergence of magnetic flux in the quiet Sun at very small spatial scales, focusing on the magnetic connection between the photosphere and chromosphere. The observational data consist of spectropolarimetric measurements and filtergrams taken with the Hinode satellite and the Dutch Open Telescope. We find that a significant fraction of the magnetic flux present in internetwork regions appears in the form of Omega-shaped loops. The emergence rate is 0.02 loops per hour and arcsec^{-2}, which brings 1.1 x 10^12 Mx s^{-1} arcsec^{-2} of new flux to the solar surface. Initially, the loops are observed as small patches of linear polarization above a granular cell. Shortly afterwards, two footpoints of opposite polarity become visible in circular polarization within or at the edges of the granule and start to move toward the adjacent intergranular space. The orientation of the footpoints does not seem to obey Hale's polarity rules. The loops are continuously buffeted by convective motions, but they always retain a high degree of coherence. Interestingly, 23% of the loops that emerge in the photosphere reach the chromosphere (16 cases out of 69). They are first detected in Fe I 630 nm magnetograms and 5 minutes later in Mg I b 517.3 nm magnetograms. After about 8 minutes, some of them are also observed in Ca II H line-core images, where the footpoints produce small brightness enhancements.Comment: Accepted for publication in Ap

    Source identification for mobile devices, based on wavelet transforms combined with sensor imperfections

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    One of the most relevant applications of digital image forensics is to accurately identify the device used for taking a given set of images, a problem called source identification. This paper studies recent developments in the field and proposes the mixture of two techniques (Sensor Imperfections and Wavelet Transforms) to get better source identification of images generated with mobile devices. Our results show that Sensor Imperfections and Wavelet Transforms can jointly serve as good forensic features to help trace the source camera of images produced by mobile phones. Furthermore, the model proposed here can also determine with high precision both the brand and model of the device

    Implementación de estándares DICOM SR y HL7 CDA para la creación y edición de informes de estudios imagenológicos

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    La aparición de nuevas tecnologías de la información, así como estándares y acuerdos, permite la interoperabilidad entre aplicaciones de sistemas de salud en distintas partes del mundo. El presente artículo introduce un estudio que pretende facilitar el uso de estándares y tecnologías disponibles hacia el sector salud, especialmente hacia instituciones hospitalarias. El trabajo parte del uso de los estándares HL7 CDA y DICOM SR para la edición de informes de estudios imagenológicos, debido a que la emisión de estos informes constituye una de las actividades fundamentales de los departamentos de diagnósticos por imágenes. Se describen las principales funcionalidades y características, como base para un sistema informático capaz de adaptarse a los distintos ambientes y escenarios, permitiendo agilizar y estandarizar el proceso que se informatiza. Con la implementación de estos estándares se lograrían sistemas con fuertes características de estandarización, generalidad, flexibilidad, accesibilidad, bajo costo de implementación, bajas necesidades en infraestructura, perdurables en el tiempo e independientes al cambio de la tecnología. Palabras claves: DICOM SR, estándares, HL7 CDA, interoperabilidad. </p

    Photospheric Magnetic Fields of the Trailing Sunspots in Active Region NOAA 12396

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    The solar magnetic field is responsible for all aspects of solar activity. Sunspots are the main manifestation of the ensuing solar activity. Combining high-resolution and synoptic observations has the ambition to provide a comprehensive description of the sunspot growth and decay processes. Active region NOAA 12396 emerged on 2015 August 3 and was observed three days later with the 1.5-meter GREGOR solar telescope on 2015 August 6. High-resolution spectropolarimetric data from the GREGOR Infrared Spectrograph (GRIS) are obtained in the photospheric Si I λ\lambda 1082.7 nm and Ca I λ\lambda1083.9 nm lines, together with the chromospheric He I λ\lambda1083.0 nm triplet. These near-infrared spectropolarimetric observations were complemented by synoptic line-of-sight magnetograms and continuum images of the Helioseismic and Magnetic Imager (HMI) and EUV images of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO).Comment: 4 pages, 2 figures, to be published in "Solar Polarization Workshop 8", ASP Proceedings, Luca Belluzzi (eds.
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