62 research outputs found

    Detecing Anti-Vaccine Users on Twitter

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    Vaccine hesitancy, which has recently been driven by online narratives, significantly degrades the efficacy of vaccination strategies, such as those for COVID-19. Despite broad agreement in the medical community about the safety and efficacy of available vaccines, a large number of social media users continue to be inundated with false information about vaccines and are indecisive or unwilling to be vaccinated. The goal of this study is to better understand anti-vaccine sentiment by developing a system capable of automatically identifying the users responsible for spreading anti-vaccine narratives. We introduce a publicly available Python package capable of analyzing Twitter profiles to assess how likely that profile is to share anti-vaccine sentiment in the future. The software package is built using text embedding methods, neural networks, and automated dataset generation and is trained on several million tweets. We find this model can accurately detect anti-vaccine users up to a year before they tweet anti-vaccine hashtags or keywords. We also show examples of how text analysis helps us understand anti-vaccine discussions by detecting moral and emotional differences between anti-vaccine spreaders on Twitter and regular users. Our results will help researchers and policy-makers understand how users become anti-vaccine and what they discuss on Twitter. Policy-makers can utilize this information for better targeted campaigns that debunk harmful anti-vaccination myths

    Quantifying How Hateful Communities Radicalize Online Users

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    While online social media offers a way for ignored or stifled voices to be heard, it also allows users a platform to spread hateful speech. Such speech usually originates in fringe communities, yet it can spill over into mainstream channels. In this paper, we measure the impact of joining fringe hateful communities in terms of hate speech propagated to the rest of the social network. We leverage data from Reddit to assess the effect of joining one type of echo chamber: a digital community of like-minded users exhibiting hateful behavior. We measure members' usage of hate speech outside the studied community before and after they become active participants. Using Interrupted Time Series (ITS) analysis as a causal inference method, we gauge the spillover effect, in which hateful language from within a certain community can spread outside that community by using the level of out-of-community hate word usage as a proxy for learned hate. We investigate four different Reddit sub-communities (subreddits) covering three areas of hate speech: racism, misogyny and fat-shaming. In all three cases we find an increase in hate speech outside the originating community, implying that joining such community leads to a spread of hate speech throughout the platform. Moreover, users are found to pick up this new hateful speech for months after initially joining the community. We show that the harmful speech does not remain contained within the community. Our results provide new evidence of the harmful effects of echo chambers and the potential benefit of moderating them to reduce adoption of hateful speech


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    O crescente avan√ßo tecnol√≥gico nas mais diversas √°reas tem intensificado o desenvolvimento de Ve√≠culos A√©reos N√£o Tripulados (VANTs) de elevada complexidade para miss√Ķes militares e civis. O emprego de materiais mais leves e configura√ß√Ķes com asas de grande efici√™ncia aerodin√Ęmica √© um diferencial competitivo nesta √°rea de estudo. Neste artigo √© apresentado o projeto de um sistema para corte de asas de poliestireno expandido com perfil aerodin√Ęmico para VANTs de asa fixa. Para elabora√ß√£o do trabalho √© utilizada a metodologia de projetos fundamentada atrav√©s do desenvolvimento das etapas de Planejamento de Projeto, Projeto Informacional, Projeto Conceitual, Projeto Preliminar e Projeto Detalhado. Na realiza√ß√£o das etapas, todas as informa√ß√Ķes relevantes ao desenvolvimento do projeto foram compiladas utilizando as ferramentas preconizadas pela metodologia adotada. O resultado se mostrou satisfat√≥rio, uma vez que o prot√≥tipo f√≠sico do produto evidenciou a funcionalidade do projeto. O custo de fabrica√ß√£o firmou-se aproximadamente 40% abaixo da m√©dia dos produtos similares encontrados no mercado, viabilizando a fabrica√ß√£o. Dentro deste contexto, constatou-se que o emprego da metodologia adotada para o estudo, permite desenvolver alternativas de solu√ß√£o que satisfazem √†s necessidades dos clientes, resultando em um equipamento que atende todas as fun√ß√Ķes requeridas

    No Love Among Haters: Negative Interactions Reduce Hate Community Engagement

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    While online hate groups pose significant risks to the health of online platforms and safety of marginalized groups, little is known about what causes users to become active in hate groups and the effect of social interactions on furthering their engagement. We address this gap by first developing tools to find hate communities within Reddit, and then augment 11 subreddits extracted with 14 known hateful subreddits (25 in total). Using causal inference methods, we evaluate the effect of replies on engagement in hateful subreddits by comparing users who receive replies to their first comment (the treatment) to equivalent control users who do not. We find users who receive replies are less likely to become engaged in hateful subreddits than users who do not, while the opposite effect is observed for a matched sample of similar-sized non-hateful subreddits. Using the Google Perspective API and VADER, we discover that hateful community first-repliers are more toxic, negative, and attack the posters more often than non-hateful first-repliers. In addition, we uncover a negative correlation between engagement and attacks or toxicity of first-repliers. We simulate the cumulative engagement of hateful and non-hateful subreddits under the contra-positive scenario of friendly first-replies, finding that attacks dramatically reduce engagement in hateful subreddits. These results counter-intuitively imply that, although under-moderated communities allow hate to fester, the resulting environment is such that direct social interaction does not encourage further participation, thus endogenously constraining the harmful role that these communities could play as recruitment venues for antisocial beliefs.Comment: 13 pages, 5 figures, 2 table

    Auditing Elon Musk's Impact on Hate Speech and Bots

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    On October 27th, 2022, Elon Musk purchased Twitter, becoming its new CEO and firing many top executives in the process. Musk listed fewer restrictions on content moderation and removal of spam bots among his goals for the platform. Given findings of prior research on moderation and hate speech in online communities, the promise of less strict content moderation poses the concern that hate will rise on Twitter. We examine the levels of hate speech and prevalence of bots before and after Musk's acquisition of the platform. We find that hate speech rose dramatically upon Musk purchasing Twitter and the prevalence of most types of bots increased, while the prevalence of astroturf bots decreased.Comment: 3 figures, 1 tabl


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    Este trabalho apresenta o desenvolvimento de um aplicativo para auxiliar no ensino de Sistema Solar utilizando Realidade Aumentada (http://tecedu.inf.furb.br/geografia/fes/). O desenvolvimento ocorreu utilizando o motor de jogos Unity 3D usando Vuforia para simular a Realidade Aumentada. São apresentados neste trabalho conceitos e ideias usados no desenvolvimento do aplicativo, além da Interface Tangível utilizada para interagir com a mesma. Como resultado, o aplicativo foi exportado para a plataforma Android e foram realizados testes com um grupo de alunos. Durante os testes foi possível notar uma recepção positiva, mesmo havendo certa dificuldade na utilização do aplicativo, sobretudo por conta do hardware. A reação dos alunos durante os testes foi de interesse pelo uso do aplicativo, mesmo que apenas para ver seu funcionamento

    Desafios e Inova√ß√Ķes das Ci√™ncias Biol√≥gicas em tempos de Pandemia

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    O VII Simp√≥sio de Integra√ß√£o das P√≥s-Gradua√ß√Ķes do CCB ocorreu em formato totalmente online dos dias 09 a 12 de dezembro, contando com palestrantes nacionais e internacionais de diversas institui√ß√Ķes de pesquisa. No SIP tivemos uma palestra magna e cinco mesas redondas, onde foi poss√≠vel discutir diversos temas extremamente importantes, n√£o somente para a comunidade cient√≠fica, mas tamb√©m para a comunidade n√£o cient√≠fica. Todas as atividades ocorreram em forma de Live, havendo grande participa√ß√£o dos inscritos no evento por meio de chat, o que proporcionou um maior debate entre os convidados. Computando todas as atividades disponibilizadas no canal do SIP no YouTube j√° ultrapassam de 2.500 visualiza√ß√Ķes. No SIP foram aprovados 77 resumos, onde os autores realizaram apresenta√ß√£o em formato de graphical abstract, sendo alguns escolhidos por um Comit√™ Cient√≠fico Avaliador para realiza√ß√£o de apresenta√ß√£o oral. Ao final, foram premiadas 3 apresenta√ß√Ķes orais e 3 graphical abstract. Al√©m da discuss√£o de assuntos t√£o importantes, o evento proporcionou intera√ß√£o entre os graduandos, p√≥s-graduandos e professores do Centro de Ci√™ncias Biol√≥gicas da UFSC, levando a divulga√ß√£o dos excelentes trabalhos realizados na Universidade e intensificando as parcerias entre laborat√≥rios


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    On the rice crop, weed species more adapted to the production system appear in greater incidence in the area, thus, crop rotation can be an alternative to help reduce the weed seed bank. In this sense, the objective of this work was to evaluate the dynamics of the barnyardgrass (Echinochloa spp.) and alexandergrass (Urochloa plantaginea) seed banks in lowlands, in response to crop rotation and soil management. Rice, soybean and sorghum crops were used under conventional tillage and no-till system, cultivated in strips. Barnyardgrass and alexandergrass seed banks were evaluated after two years of cultivation, in the top 0-5 and 5-10 cm layers of soil. Barnyardgrass and alexandergrass seed bank densities were higher in continuous sorghum cultivation compared to rice cultivation. There was no difference of the seed bank between different soil layers, except for alexandergrassin continuous sorghum cultivation. The continuous sorghum cultivation in lowlands, without the use of a post-emergence herbicide, increases barnyardgrass and alexandergrassseed bank.No monocultivo de arroz, as esp√©cies daninhas mais adaptadas a este sistema de produ√ß√£o aparecem em maior incid√™ncia na √°rea. A rota√ß√£o de culturas pode ser uma alternativa para auxiliar na redu√ß√£o do banco de sementes de plantas daninhas. Nesse sentido o objetivo do trabalho foi avaliar a din√Ęmica do banco de sementes de capim-arroz (Echinochloa spp.) e papu√£ (Urochloa plantaginea) em terras baixas, em combina√ß√Ķes de rota√ß√£o de culturas e do manejo de solo. Foram utilizadas as culturas de arroz, soja e sorgo, sob o manejo de preparo do solo convencional e sistema de semeadura direta, cultivado em faixas. Foi avaliado o banco de sementes de capim-arroz e papu√£ ap√≥s dois anos de cultivo, na camada de 0-5 e 5-10 cm de profundidade. A densidade do banco de sementes de capimarroz e papu√£ foi superior no monocultivo de sorgo em rela√ß√£o ao cultivo de arroz. N√£o houve diferen√ßa do banco de sementes de plantas daninhas entre diferentes camadas de solo, exceto para o papu√£ no monocultivo de sorgo. O monocultivo de sorgo, sem aplica√ß√£o de herbicidas em p√≥s-emerg√™ncia, em terras baixas incrementa o banco de sementes de capim-arroz e papu√£

    Fitotoxicidade de clomazone associado com dietholate à cultura do trigo

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    Nowadays it has become important to test new alternatives herbicide molecules, even if they are not registered for the control of weeds that infest wheat, to evaluate the phytotoxicity to culture and the ability to manage resistant weeds to the products used for this purpose. Thus, an experiment was conducted to evaluate the Phytotoxicity of clomazone associated or not to the dietholate safener applied on wheat. The experiment was conducted in a completely randomized design, arranged in a factorial scheme (5 x 4) + 2 + 2, with four replications. In the factor allocated to dietholate doses (0, 120, 240, 360 and 480 g per 100 kg of seed) and the B clomazone doses (0, 198, 396 and 594 g ha-1). Additional Treatments were the control treatments infested and without the application of herbicide, and the application in post-emergence of iodosulfuron-methyl (5 g ha-1) and pyroxsulam (18 g ha-1). The increase in clomazone doses caused increased phytotoxicity to wheat, with or without the safener. The dietholate showed no ability to protect the wheat from the phytotoxic effects of the herbicide clomazone. The use of clomazone associated with dietholate for weed control on wheat is not recommended. The pyroxsulam was the herbicide that caused minor injuries to wheat.Na atualidade torna-se importante testar novas alternativas de mol√©culas herbicidas, mesmo que n√£o sejam registradas para o controle de plantas daninhas infestantes do trigo, para avaliar a fitotoxicidade √† cultura e a possibilidade de manejar plantas daninhas resistentes aos produtos utilizados para esse fim. Diante disso, um experimento foi realizado para avaliar a fitotoxicidade do herbicida clomazone associado ou n√£o ao safener dietholate aplicados √† cultura do trigo. O experimento foi realizado em delineamento inteiramente casualizado, arranjado em esquema fatorial (5 x 4) + 2 + 2, com quatro repeti√ß√Ķes. No fator A alocou-se as doses de dietholate (0, 120, 240, 360 e 480 g para 100 kg de semente) e o no B as doses de clomazone (0, 198, 396 e 594 g ha-1). Os tratamentos adicionais foram constitu√≠dos pelas testemunhas infestadas e sem herbicida, e a aplica√ß√£o em p√≥s-emerg√™ncia de iodosulfuron-methyl (5 g ha-1) e pyroxsulam (18 g ha-1). O incremento das doses de clomazone ocasionou o aumento da fitotoxicidade ao trigo, associado ou n√£o ao protetor. O dietholate n√£o apresentou capacidade de proteger o trigo dos efeitos fitot√≥xicos do herbicida clomazone. N√£o √© recomendado o uso do clomazone associado ao diethole para o controle de plantas daninhas infestantes do trigo. O pyroxsulam foi o herbicida que causou menores inj√ļrias ao trigo
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