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    Gene expression analyses reveal a relationship between conidiation and cerato-platanin in homokaryotic and heterokaryotic strains of the fungal plant pathogen Heterobasidion irregulare

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    The Basidiomycete Heterobasidion irregulare was recently sequenced and three cerato-platanin encoding genes were found in its genome (HiCPs). Cerato-platanin family proteins (CPPs) are produced by both plant pathogenic and non-pathogenic fungi, and can act both as virulence factors and elicitors of defence responses. In fungal life these proteins seem to play a dual role, in the fungal cell wall and in the fungus-plant interaction, but most data available to date on CPPs derive from studies performed on Ascomycetes. In the present study, we investigated the expression of HiCPs in three homokaryotic isolates and two heterokaryotic isolates of the forest pathogen H. irregulare. Transcription of HiCPs was analysed both at the edge and at the centre of the fungal colony and compared between homokaryon and heterokaryon. Results showed that only HiCP1 and HiCP2 are likely to be translated in H. irregulare and that, under the tested conditions, HiCP1 is by far the gene with the highest transcript abundance among HiCPs. HiCP1 did not show any preferential expression in different sections of the fungal colony, while HiCP2 was significantly more expressed at the colony centre, thus suggesting a link with the production of conidia. The level of expression of HiCPs in heterokaryons was generally comparable to that of one or both the parental homokaryons, irrespective of the colony section, thus demonstrating that HiCPs are not transcriptionally influenced by the heterokaryotic stage

    Transcriptional study of cerato-platanin encoding genes in homokaryotic and heterokaryotic isolates of the forest pathogen Heterobasidion irregulare.

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    The forest pathogen Heterobasidion irregulare (Basidiomycota) was recently sequenced and three cerato-platanin encoding genes were found in its genome (HiCPs). Cerato-Platanin Proteins (CPPs) are a family of proteins well known for they resistance-inducing ability when applied on plants. What is still poorly understood is their role in fungal life. These proteins seem to play both a role in the fungal cell wall and a role in the fungus-plant interaction, but most data available to date on CPPs derive from studies performed on Ascomycetes. In the present study, we investigated the expression of HiCPs in three homokaryotic isolates and two heterokaryotic isolates of the plant pathogen H. irregulare. Homokaryotic and heterokaryotic mycelia not only play different roles in the infectious process but also differ in their biology: clamp connections are formed in the heterokaryotic mycelia. Transcription of HiCPs was analysed both at the edge and at the centre of the fungal colony and compared between homokaryon and heterokaryon. Results showed HiCP1 to be the gene with the highest transcript abundance among HiCPs. HiCP1 did not show any preferential expression in different sections of the fungal colony, while HiCP2 was significantly more expressed at the colony centre, thus suggesting a link with the production of conidia. The level of expression of HiCPs in heterokaryons was generally comparable to that of one or both the parental homokaryons, irrespective of the colony section, thus demonstrating that HiCPs are not transcriptionally influenced by the heterokaryotic stage

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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