Semi-selective culture medium for Exserohilum turcicum isolation from corn seeds

Northern corn leaf blight, caused by Exserohilum turcicum (Et), is a disease of widespread occurrence in regions where corn, sweetcorn and popcorn are grown. This disease has great potential to cause damage and has been studied for years, but the association of its causal agent with seeds remains unconfirmed. Thus, the availability of a sensitive method to detect and quantify the inoculum in seeds, even at low incidence, is essential. The aim of this study was to develop a method to detect and quantify the presence of the fungus infecting and infesting corn and popcorn seeds. Artificially and naturally infected seeds were employed to develop the medium. The semi-selective medium was composed of carbendazim (active ingredient) (60 mg/L), captan (30 mg/L), streptomycin sulfate (500 mg/L) and neomycin sulfate (600 mg/L) aggregated to the medium lactose casein hydrolysate agar medium. By using this, Et was detected in naturally infected corn seeds, showing 0.124% incidence, in four out of ten analyzed samples. In addition, 1.04 conidia were detected per infested seed. By means of isolation, pathogenicity test, morphological characterization and comparison with descriptions of the species in the literature, the fungus isolated from the seeds was confirmed to be Et. Both infection and infestation were considered low; thus, for studies of Et detection in corn seeds, the use of semi-selective medium and more than 1,200 seeds/sample is suggested.Fil: De Rossi, Roberto Luis. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias; Argentin

Os fundamentos da interdisciplinaridade no Campo da Comunicação : uma análise a partir dos artigos da Compós e da Intercom

São recorrentes as pesquisas com temática interdisciplinar no Campo da Comunicação, porém pouco se conhece os aportes teóricos utilizados para a sua fundamentação. Com base nos artigos publicados nos anais da Compós e da Intercom, entre os anos de 2005 e 2015, e recorrendo-se ao método bibliométrico de análise de citações, a presente pesquisa objetivou identificar os pilares teóricos da interdisciplinaridade no Campo da Comunicação brasileira. Dentre os principais resultados destaca-se, a partir dos autores citados, que os fundamentos teóricos sobre a interdisciplinaridade do Campo da Comunicação são restritos, principalmente nos textos da Compós. Constatou-se que a autoria dos textos que fundamentam o discurso da interdisciplinaridade nos artigos da Compós é predominantemente restrita a autores vinculados a uma única universidade brasileira e a textos de autores do próprio Campo da Comunicação. Não foram encontradas fortes influências, medidas pelas citações, para textos clássicos do campo da filosofia, educação, sociologia, etc. Nos artigos da Intercom, diferentemente, identificou-se fundamentação sobre interdisciplinaridade de outros campos e outros autores nacionais e internacionais, no entanto, ainda de maneira restrita. Ressalta-se a importância de maior mobilização de autores para melhor fundamentação teórica nos estudos da Comunicação, quer sejam na temática interdisciplinar ou contra interdisciplinar, pois constatou-se que em ambos os casos a fundamentação dos discursos aponta fragilidades e pouca amplitude de teorias

Breaking the News: First Impressions Matter on Online News

A growing number of people are changing the way they consume news, replacing the traditional physical newspapers and magazines by their virtual online versions or/and weblogs. The interactivity and immediacy present in online news are changing the way news are being produced and exposed by media corporations. News websites have to create effective strategies to catch people's attention and attract their clicks. In this paper we investigate possible strategies used by online news corporations in the design of their news headlines. We analyze the content of 69,907 headlines produced by four major global media corporations during a minimum of eight consecutive months in 2014. In order to discover strategies that could be used to attract clicks, we extracted features from the text of the news headlines related to the sentiment polarity of the headline. We discovered that the sentiment of the headline is strongly related to the popularity of the news and also with the dynamics of the posted comments on that particular news.Comment: The paper appears in ICWSM 201

Fungicide baseline for mycelial sensitivity of Exserohilum turcicum, causal agent of northern corn leaf blight

Northern corn leaf blight, caused by Exserohilum turcicum (Et), is one of the major corn diseases which can reduce grain yield and quality. The aim of this study was to determine the mycelial sensitivity of ten Et isolates, five from Argentina and five from Brazil, to six fungicides (carbendazim, captan, fludioxinil, metalaxyl, iprodione and thiram) used in seed treatment. The inhibitory concentration (IC50) was determined by using seven concentrations of the fungicides supplemented to the agar medium. The mycelial colony diameter was measured with a digital caliper. Experimental design was completely randomized with four replicates. Data on the percent mycelial growth inhibition were analyzed by logarithmic regression and the IC50 was calculated. The fungicide iprodione was the most potent, with IC50 < 0.01 mg/L, followed by fludioxonil, IC50 0.31 mg/L, and thiram, 1.37 mg/L. Carbendazim, metalaxyl and captan were classified as non-fungitoxic, showing IC50 > 50 mg/L for all isolates. Although iprodione is the most potent fungicide, it is not used for corn seed treatment. The IC50s obtained in this study can be used as baseline for future monitoring studies of Et sensitivity to fungicides.Fil: De Rossi, Roberto Luis. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias; Argentin

A colaboração premiada como meio eficiente de investigação das organizações criminosas

Resumo: O presente trabalho tem como escopo a análise do instituto da colaboração premiada como instrumento de política criminal do Estado em face do crime organizado. Para tanto, procede-se ao exame deste fenômeno criminoso à luz do conceito que lhe foi recém atribuído pela Lei n. 12.850/2013, de dois de agosto, bem como das características peculiares identificadas pela doutrina acerca desta espécie de associação ilícita, destacando-se a estrutura complexa e as regras existentes entre os membros, tal qual a lei do silêncio, em razão do que elege-se como meio eficiente de investigação destas organizações, geralmente fechadas em muros, a colaboração premiada, sobre o que se debruça nesta empreitada acadêmic

A Dataset of Fact-Checked Images Shared on WhatsApp During the Brazilian and Indian Elections

Recently, messaging applications, such as WhatsApp, have been reportedly abused by misinformation campaigns, especially in Brazil and India. A notable form of abuse in WhatsApp relies on several manipulated images and memes containing all kinds of fake stories. In this work, we performed an extensive data collection from a large set of WhatsApp publicly accessible groups and fact-checking agency websites. This paper opens a novel dataset to the research community containing fact-checked fake images shared through WhatsApp for two distinct scenarios known for the spread of fake news on the platform: the 2018 Brazilian elections and the 2019 Indian elections.Comment: 7 pages. This is a preprint version of an accepted paper on ICWSM'20. Please, consider to cite the conference version instead of this on