1,967 research outputs found

    Techy, Classy, and Social: Electric Vehicles and Brand Communication on Twitter

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    This study explored brand communication and audience engagement metrics for automakers selling electrified vehicle models in the U.S. The dataset included all Twitter communication from 27 major brand accounts during a one-year period (July 2018 through June 2019). Data analysis focused on communication volume, explicit saturation, and discourse clustering around key themes and variables. The study found abysmal amounts of EV-category explicit terminology for all brands, particularly so for U.S. accounts. Audience engagement was stronger for brands that pulled EVs into the lifestyle of their targets, than for brands pushing normative messages about environmental concerns

    XLab: Early Indications & Warnings from Open Source Data with Application to Biological Threat

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    XLab is an early warning system that addresses a broad range of national security threats using a flexible, rapidly reconfigurable architecture. XLab enables intelligence analysts to visualize, explore, and query a knowledge base constructed from multiple data sources, guided by subject matter expertise codified in threat model graphs. This paper describes a novel system prototype that addresses threats arising from biological weapons of mass destruction. The prototype applies knowledge extraction analytics-”including link estimation, entity disambiguation, and event detection-”to build a knowledge base of 40 million entities and 140 million relationships from open sources. Exact and inexact subgraph matching analytics enable analysts to search the knowledge base for instances of modeled threats. The paper introduces new methods for inexact matching that accommodate threat models with temporal and geospatial patterns. System performance is demonstrated using several simplified threat models and an embedded scenario

    PHENOMENON OF MIGRATION AND ITS MANIFESTATIONS IN THE MODERN WORLD

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    This article gives the theoretical basis and defines the developed approaches to viewing migration as an inevitable social process in national economy. It considers the main trends in developing migration processes in member states of the Organisation for Economic Co-operation and Development as well as social and economic consequences for developed countries in conditions of common economic and legal space. It shows the specificities of supranational governance practices, cooperation within the framework of the Organisation for Economic Co-operation and Development which has a particular impact on the migration policy. The governments of the European Union member-states pay great attention to the questions of refugee reception, legalization and adaptation of migrant workers, creating special programmes, organizing free language courses, pursuing the policy of human rights protection with regard to migrants of both legal and illegal status. The authors consider the lack of cultural assimilation as one of the main reasons for the failure of multiculturalism in Europe

    STEREO and ACE observations of CIR particles

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    In the present solar minimum, corotating interaction regions (CIRs) produce frequent particle enhancements at 1 AU as observed at STEREO and ACE. As the two STEREO spacecraft move apart, differences in CIR time profiles observed at each spacecraft are becoming large. The timing differences are often roughly similar to the corotation time lag between the two spacecraft, however many of the features seen at Ahead and Behind require more than just a time shift. Perhaps transient disturbances in the solar wind affect connection to or transport from the shock, or temporal changes occur in the CIR shock itself. Additional timing differences of >1 day result from the different heliographic latitudes of the two STEREO spacecraf

    Subitizing with Variational Autoencoders

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    Numerosity, the number of objects in a set, is a basic property of a given visual scene. Many animals develop the perceptual ability to subitize: the near-instantaneous identification of the numerosity in small sets of visual items. In computer vision, it has been shown that numerosity emerges as a statistical property in neural networks during unsupervised learning from simple synthetic images. In this work, we focus on more complex natural images using unsupervised hierarchical neural networks. Specifically, we show that variational autoencoders are able to spontaneously perform subitizing after training without supervision on a large amount images from the Salient Object Subitizing dataset. While our method is unable to outperform supervised convolutional networks for subitizing, we observe that the networks learn to encode numerosity as basic visual property. Moreover, we find that the learned representations are likely invariant to object area; an observation in alignment with studies on biological neural networks in cognitive neuroscience

    Las competencias profesionales y/o los saberes en la formación universitaria: Requerimientos en los nuevos escenarios sociales y laborales

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    La formación profesional debe responder a un perfil y a una estructura curricular que obliga a desarrollarse desde una visión dinámica, insertada en una realidad en cambio constante. Bajo este entendido, es importante preguntarse ¿qué competencias o qué saberes se requieren en la preparación universitaria? ¿Se debe trabajar con el enfoque de competencias… o continuar con el de saberes? En la búsqueda de respuestas, se quería constatar si los diferentes aportes teóricos existentes sobre el particular empataban con la realidad del entorno del Área Metropolitana de Monterrey, N.L., México, por lo que se utilizó como base una investigación a empleadores de egresados de la UAN

    Doxorubicin-Induced Cardiotoxicity in Collaborative Cross (CC) Mice Recapitulates Individual Cardiotoxicity in Humans.

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    Anthracyclines cause progressive cardiotoxicity whose ultimate severity is individual to the patient. Genetic determinants contributing to this variation are difficult to study using current mouse models. Our objective was to determine whether a spectrum of anthracycline induced cardiac disease can be elicited across 10 Collaborative Cross mouse strains given the same dose of doxorubicin. Mice from ten distinct strains were given 5 mg/kg of doxorubicin intravenously once weekly for 5 weeks (total 25 mg/kg). Mice were killed at acute or chronic timepoints. Body weight was assessed weekly, followed by terminal complete blood count, pathology and a panel of biomarkers. Linear models were fit to assess effects of treatment, sex, and sex-by-treatment interactions for each timepoint. Impaired growth and cardiac pathology occurred across all strains. Severity of these varied by strain and sex, with greater severity in males. Cardiac troponin I and myosin light chain 3 demonstrated strain- and sex-specific elevations in the acute phase with subsequent decline despite ongoing progression of cardiac disease. Acute phase cardiac troponin I levels predicted the ultimate severity of cardiac pathology poorly, whereas myosin light chain 3 levels predicted the extent of chronic cardiac injury in males. Strain- and sex-dependent renal toxicity was evident. Regenerative anemia manifested during the acute period. We confirm that variable susceptibility to doxorubicin-induced cardiotoxicity observed in humans can be modeled in a panel of CC strains. In addition, we identified a potential predictive biomarker in males. CC strains provide reproducible models to explore mechanisms contributing to individual susceptibility in humans

    Excited-State Lifetimes of DNA-Templated Cyanine Dimer, Trimer, and Tetramer Aggregates: The Role of Exciton Delocalization, Dye Separation, and DNA Heterogeneity

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    DNA-templated molecular (dye) aggregates are a novel class of materials that have garnered attention in a broad range of areas including light harvesting, sensing, and computing. Using DNA to template dye aggregation is attractive due to the relative ease with which DNA nanostructures can be assembled in solution, the diverse array of nanostructures that can be assembled, and the ability to precisely position dyes to within a few Angstroms of one another. These factors, combined with the programmability of DNA, raise the prospect of designer materials custom tailored for specific applications. Although considerable progress has been made in characterizing the optical properties and associated electronic structures of these materials, less is known about their excited-state dynamics. For example, little is known about how the excited-state lifetime, a parameter essential to many applications, is influenced by structural factors, such as the number of dyes within the aggregate and their spatial arrangement. In this work, we use a combination of transient absorption spectroscopy and global target analysis to measure excited-state lifetimes in a series of DNA-templated cyanine dye aggregates. Specifically, we investigate six distinct dimer, trimer, and tetramer aggregates—based on the ubiquitous cyanine dye Cy5—templated using both duplex and Holliday junction DNA nanostructures. We find that these DNA-templated Cy5 aggregates all exhibit significantly reduced excited-state lifetimes, some by more than 2 orders of magnitude, and observe considerable variation among the lifetimes. We attribute the reduced excited-state lifetimes to enhanced nonradiative decay and proceed to discuss various structural factors, including exciton delocalization, dye separation, and DNA heterogeneity, that may contribute to the observed reduction and variability of excited-state lifetimes. Guided by insights from structural modeling, we find that the reduced lifetimes and enhanced nonradiative decay are most strongly correlated with the distance between the dyes. These results inform potential tradeoffs between dye separation, excitonic coupling strength, and excited-state lifetime that motivate deeper mechanistic understanding, potentially via further dye and dye template design
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