1,721,002 research outputs found
Stress osmotico indotto da saccarosio e PEG : incremento dei fenoli totali, attività antiossidante e prolina in Achillea in vitro
No full textE’ stato indagato l’effetto di saccarosio e PEG, utilizzati al fine indurre stress osmotico, sul livello di fenoli totali, attività antiossidante e accumulo di prolina in foglie e radici di piante di Achillea collina allevate in vitro. L’incremento della concentrazione di saccarosio dal 3 al 12% ha determinato una significativa riduzione dello sviluppo di foglie e radici. Il livello di fenoli totali mostrava un incremento progressivo all’aumentare della concentrazione di saccarosio ed era 3 volte più elevato nelle foglie di piante cresciute in presenza di saccarosio al 12% rispetto al controllo (3% saccarosio). Analogo andamento mostrava l’attività antiossidante degli estratti metanolici di achillea, sebbene l’effetto della concentrazione più elevata di saccarosio fosse meno pronunciato. Il livello della prolina mostrava un notevole incremento sia nelle foglie sia nelle radici delle piante cresciute ad alti livelli di saccarosio. Al fine di approfondire le indagini sull’effetto dello stress osmotico su achillea allevata in vitro, sono stati attuati esperimenti utilizzando PEG6000 come osmolita. Piante allevate con saccarosio al 3% più il 3 o 6% di PEG mostravano una riduzione significativa della crescita e un incremento significativo dei fenoli totali, dell’attività antiossidante e del livello di prolina rispetto al controllo
Influenza della carenza di azoto sull'accumulo di composti fenolici in Achillea collina [Becker ex Rchb] coltivata in idroponica
No full textInfluence of light irradiance on total phenols content, antioxidant capacity, growth and photosynthetic pigments of yarrow grown in fields and controlled environment
No full textInfluence of different environmental stress conditions on phenolic accumulation in the medicinal herb Achillea collina [Becker ex Rchb]
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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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