1,720,967 research outputs found
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
Analisi di crescita e valutazione agronomica di alcune specie erbacee a basso tenore di glutine
No full textGrowth and physiological response of hydroponically-grown sunflower as affected by salinity and magnesium levels
No full textThe effects of NaCl and magnesium levels (Mg2+) on the physiological response of sunflower
were investigated. Plants were grown for 54 days in hydroponic culture with NaCl (100 mM)
or without NaCl and four concentrations of Mg2+: 0, 0.4, 1.0 and 5.0 mM. At the end of the
vegetative growing cycle of sunflower, salt stress reduced leaf area development by 51% and dry
matter accumulation by 37% as compared to non saline-treated plants; at this stage, considering
the percent reduction of partitioned plant dry matter, roots (42%) and leaves (35%) showed to
be more salt-sensitive than stem. Growth reduction was related to the drop in net CO2 assimilation
rate and stomatal conductance, which started declining later during the vegetative growth period
when leaf ion concentration started increasing. The investigated genotype was unable to exclude
ions and significant amounts of Cl− (about 1700 μmol g−1 DW) and lesser Na+ (700 μmol g−1
DW) accumulated in the leaves. The decline in net CO2 assimilation was well correlated to the
increase in leaf Cl− concentration (r 2 = 0.71) and not to leaf Na+ concentration (r 2 = 0.33).
The results suggest that, though sunflower develops an endogenous protection system by which it
redistributes this ions in the whole plant, with more ions accumulating in roots and older leaves,
growth reduction may be attributed to specific toxic effects of Cl− on photosynthetic functionality.
In both saline and non saline conditions, little or no significant differences in growth parameters
of plants exposed to a range from 0.4 to 5 mM of Mg2+ were observed. Whereas, its deficiency
caused a drastic reduction of dry matter accumulation up to 90%, due to progressive decline in
CO2 assimilation rate and chlorophyll content, with imbalances in Ca2+, Mg2+ and K+
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
Assorbimento radicale e traslocazione dell'azoto in funzione della concimazione azotata in frumento tenero
No full textNitrogen fertilization effect on quantitive-qualitative parameters of durum wheat different genotypes.
No full textLa tecnica immunoistochimica nella ricerca del papillomavirus umano (HPV) nelle biopsie della portio uterina
No full textDispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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