1,721,196 research outputs found

    The function of LHCBM4/6/8 antenna proteins in Chlamydomonas reinhardtii

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    In eukaryotic autotrophs, photosystems are composed of a core moiety, hosting charge separation and electron transport reactions, and an antenna system, enhancing light harvesting and photoprotection. In Chlamydomonas reinhardtii, the major antenna of PSII is a heterogeneous trimeric complex made up of LHCBM1-LHCBM9 subunits. Despite high similarity, specific functions have been reported for several members including LHCBM1, 2, 7, and 9. In this work, we analyzed the function of LHCBM4 and LHCBM6 gene products in vitro by synthesizing recombinant apoproteins from individual sequences and refolding them with pigments. Additionally, we characterized knock-down strains in vivo for LHCBM4/6/8 genes. We show that LHCBM4/6/8 subunits could be found as a component of PSII supercomplexes with different sizes, although the largest pool was free in the membranes and poorly connected to PSII. Impaired accumulation of LHCBM4/6/8 caused a decreased LHCII content per PSII and a reduction in the amplitude of state 1-state 2 transitions. In addition, the reduction of LHCBM4/6/8 subunits caused a significant reduction of the Non-photochemical quenching activity and in the level of photoprotection. © The Author 2017

    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

    Records of Pseudomonas syringae pv. actinidiae on Actinidia spp. in Trentino (North-East Italy)

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    During 2012-2015, extensive field surveys were performed in new and old kiwifruit orchards located in the province of Trento (North-East of Italy). Symptoms resembling those incited by Pseudomonas syringae pv. actinidiae (Psa) (i.e, leaf spotting, twig wilting) were observed mainly on Actinidia deliciosa cv. Hayward and in a new orchard planted with A. chinensis cv. Soreli. The incidence of the disease ranged from 1% to 80%, and some old Hayward orchards (i.e., 35 years old) resulted severely damaged. From all infected orchards, samples were collected and, subsequently, processed in the laboratory for isolation by following routinely procedures (Ferrante and Scortichini, 2009). Bacterial isolates were obtained from all infected kiwifruit orchards; they were identified according to the techniques described by Ferrante and Scortichini (2010). Upon repetitive-sequence PCR using BOX, ERIC and REP primer sets, their fingerprint pattern perfectly matched that shown by the pandemic Psa 3 strain CRA-FRU 8.43. In addition, with isolates representative of all the sites from where the samplings were obtained, pathogenicity tests were carried out by artificially inoculating one-year-old, pot-cultivated A. deliciosa cv. Hayward plants according to the techniques described by Ferrante and Scortichini (2009, 2010). All the isolates induced, upon 10-15 days from the inoculation, the leaf spot and wilting symptoms. On the basis of these results, we conclude that P. s. pv. actinidiae was the causal agent of the field symptoms observed in green-fleshed and yellow-fleshed kiwifruit orchards located in Trentino. This is the first record of the disease in this regio

    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

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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