12,352 research outputs found

    Coordinated amplification, coordinated inauthentic behaviour, orchestrated campaigns:A systematic literature review of coordinated inauthentic content on online social networks

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    The internet and online social networks have resulted in dramatic changes in the information landscape. Pessimistic views fear that networks and algorithms can limit exposure to various content by exposing users to pre-existing beliefs. In this respect, coordinated campaigns can amplify these individuals' voices above the crowd, capable of hijacking conversations, influencing other users and manipulating content dissemination. Through a systematic literature review, this chapter locates and synthesises related research on coordinated activities to (i) describe the state of this field by identifying the patterns and trends in the conceptual and methodological approaches, topics and practices; and (ii) shed light on potentially essential gaps in the field and suggest recommendations for future research. Findings show an evolution of the approaches used to detect coordinated activities. While bot detection was the focus in the early years, more recent research focused on using advanced computational methods based on training datasets or identifying coordinated campaigns by timely and similar content. Due to the data availability, Twitter is the most studied online social network, although studies have shown that coordinated activities can be found on other platforms. We conclude by discussing the implications of current approaches and outlining an agenda for future research

    Dados climatológicos: Estação de Pacajus, 2000.

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    Para a pesquisa agropecuária, os dados coletados em estações climatológicas são de suma importância, uma vez que possibilitam o monitoramento do clima, bem como o leventamento dos seus efeitos sobre pragas e doenças nas culturas, a estimativa da evapotranspiração, do volume e dos turnos de irrigação, dentre muitas outras finalidades básicas.bitstream/CNPAT-2010/8998/1/Ba-024.pd

    Estimativas de herdabilidade e correlações genéticas de produções parciais e total de leite de cabras mestiças.

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    O objetivo desde trabalho foi estimar as herdabilidades, repetibilidades e correlações genéticas para as produções parciais acumuladas e produção total de leite de cabras mestiças. Os dados utilizados foram obtidos de 29.703 controles leiteiros, resultantes de 1055 lactações de 400 cabras F1 Pardo-Alpina x Moxotó no período de 1988 a 1997, pertencente ao CNPC-EMBRAPA. As estimativas dos componentes de covariâncía foram obtidas pelo método da Máxima Verossimilhança Restrita, por meio do modelo animal utilizando o Programa Multiple Trait Derivate-Free Restricted Maximum Likelihood (MTDFREML). Estudou-se o efeito fixo estação-ano de parição e ordem de lactaçâo e como covariável o peso da matriz ao parto (linear) e o peso total das crias (linear). Como efeito aleatório, inclui-se o efeito genético aditivo e o efeito não correlacionado de ambiente permanente. As estimativas obtidas de herdabilidade e repetibilidade para as produções parciais aos 30, 60, 90, 120,150 dias de lactaçâo e para a produção de leite total foram 0,27 + 0,15; 0,31 + 0,15; 0,31+ 0,15; 0,31 + 0,15; 0,30 + 0,15; 0,22 + 0,15 e 0,64; 0,51; 0,58; 0,54; 0,55 e 0,48, respectivamente. As características foram correlacionadas geneticamente variando na mesma direção e sentido. As correlações genéticas obtidas encontraram-se no intervalo de 0,68 a 0,98.Disponível em Separata

    Analysing and controlling the tax evasion dynamics via majority-vote model

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    Within the context of agent-based Monte-Carlo simulations, we study the well-known majority-vote model (MVM) with noise applied to tax evasion on simple square lattices, Voronoi-Delaunay random lattices, Barabasi-Albert networks, and Erd\"os-R\'enyi random graphs. In the order to analyse and to control the fluctuations for tax evasion in the economics model proposed by Zaklan, MVM is applied in the neighborhod of the noise critical qcq_{c}. The Zaklan model had been studied recently using the equilibrium Ising model. Here we show that the Zaklan model is robust and can be reproduced also through the nonequilibrium MVM on various topologies.Comment: 18 pages, 7 figures, LAWNP'09, 200

    Stability of soybean yield through different sowing periods.

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    Soybean yield is highly affected by sowing period and there are significant productivity losses when sowings are done outward a relatively restricted period in many regions of Brazil. Breeding cultivars less sensitive to photoperiod and to temperature variations is desirable for adaptation to wider sowing period and wider latitude range and also make irrigated soybean cultivation possible during the fall-winter seasons in frost free regions. The possibility of selecting high yielding and stable lines for yield during various sowing periods wasstudied by analyzing the behavior of 100 non-selected advanced lines (F9 and F10), from each one of all possible biparental crosses involving the genotypes BR85-29009, OCEPAR 8, FT-2, and BR-13. Experiments were set up in a completely randomized design with single-plant hill plots and received supplementary irrigation. Sowing was on Sept 27, Oct 20, Nov 17, and Dec 17 in 1993/94 and Sept 20, Oct 20, Nov 17, and Dec 14 in 1994/95 at Londrina, PR, Brazil. Procedures of regression analysis and minimum variance among planting date means were efficient for selecting stable lines during the four sowing seasons. It was possible to select stable and high yielding genotypes through the four sowing periods in all the crosses. No specific cross was clearly better to produce a greater number of stable genotypes

    Guiding the Way: A Comprehensive Examination of AI Guidelines in Global Media

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    With the increasing adoption of artificial intelligence (AI) technologies in the news industry, media organizations have begun publishing guidelines that aim to promote the responsible, ethical, and unbiased implementation of AI-based technologies. These guidelines are expected to serve journalists and media workers by establishing best practices and a framework that helps them navigate ever-evolving AI tools. Drawing on institutional theory and digital inequality concepts, this study analyzes 37 AI guidelines for media purposes in 17 countries. Our analysis reveals key thematic areas, such as transparency, accountability, fairness, privacy, and the preservation of journalistic values. Results highlight shared principles and best practices that emerge from these guidelines, including the importance of human oversight, explainability of AI systems, disclosure of automated content, and protection of user data. However, the geographical distribution of these guidelines, highlighting the dominance of Western nations, particularly North America and Europe, can further ongoing concerns about power asymmetries in AI adoption and consequently isomorphism outside these regions. Our results may serve as a resource for news organizations, policymakers, and stakeholders looking to navigate the complex AI development toward creating a more inclusive and equitable digital future for the media industry worldwide.Comment: 32 pages, 2 tables, 3 figure

    Physical properties of single-crystalline fibers of the colossal-magnetoresistance manganite La0.7Ca0.3MnO3

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    We have grown high-quality single crystals of the colossal-magnetoresistance (CMR) material La0.7Ca0.3MnO3 by using the laser heated pedestal growth (LHPG) method. Samples were grown as fibers of different diameters, and with lengths of the order of centimeters. Their composition and structure were verified through X-ray diffraction, scanning electron microcopy with EDX (Energy Dispersive X-ray Analysis) and by Rietveld analysis. The quality of the crystalline fibers was confirmed by Laue and EBSD (Electron Backscatter Diffraction) patterns. Rocking curves performed along the fiber axis revealed a half-height width of 0.073 degrees. The CMR behavior was confirmed by electrical resistivity and magnetization measurements as a function of temperature.Comment: 11 pages (including 3 figures); to appear in Appl. Phys. Let
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