1,720,972 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
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
Dispelling 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
Inoculation and fertilization affect sulla performance in a new cultivation area
No full textThe forage legume sulla (Sulla coronaria (L.) Medik) establishes a host-speciic nitrogen-ixing symbiotic
interaction and its inoculation is mandatory where it is cultivated for the irst time or not present as
spontaneous species. his study aimed at investigating the efects of inoculation and fertilizer nitrogen (N)
on yield performance and N-ixation ability of sulla established in a new habitat within a Mediterranean
agropastoral area of Sardinia (Italy). Sulla plants, previously inoculated with peat-based inoculant, liquid
inoculant and soil, and unfertilized (N0) or N100 fertilized, were sampled at full vegetative stage. Length,
dry matter yield and ixed N of sulla shoots and roots were measured. Inoculation signiicantly afected
several traits. In particular, plant DM varied from 0.5 to 3.2 g in uninoculated and inoculated plants,
respectively. At N0 and using soil as inoculant, shoot ixed N reached 43 mg plant-1 whereas it was
negligible in the uninoculated control. Under N100, N-ixation ability of sulla was decreased. Results
highlighted that inoculation is essential for extending the cultivation of sulla in a new habitat
Combined effects of microenvironment and land use on C fluxes in a Mediterranean agro-silvopastoral system
No full textAppropriate agroforestry practices might contribute to carbon sequestration and cope with climate change by modulating ecosystem services. It is known that land use change might affect soil-atmosphere carbon dioxide (CO2) effluxes of agro-silvopastoral systems. However, little information is available at single microenvironment level. Across four years, fortnightly measurements of soil respiration were carried out at different microenvironment (beneath tree cover vs open areas) and land use (native understorey vs its conversion into improved pasture) within a high-density evergreen cork oak forest of Sardinia (Italy). We also monitored aboveground dry matter yields and soil carbon stocks. Measurements revealed that the two investigated microenvironments widely differed for the amounts of photosynthetically active radiation and microclimatic traits such as soil water content, air humidity, soil and air temperature. High seasonal and inter-annual variability in soil respiration rates was recorded (range 0.3–12.6 CO2 μmol m−2 s-1) and the peak values were reached in the summer of the third year in the improved pasture beneath tree cover. The conversion of the native understorey into improved pasture beneath cork oak increased significantly the annual cumulative soil respiration for three consecutive years, reaching values of about 71, 36 and 100 t CO2 ha−1 yr−1, which were from 38 to 88 % higher than the remaining treatments. On average, heterotrophic component represented from 68–76% of soil respiration. An extreme drought event, which was emblematic of a climate change context, was experienced in the second year. It countered the increase in the heterotrophic component of soil respiration and minimized up to 20-fold the forage on offer from pasture swards. Based on measured CO2 effluxes, the study demonstrated that the effects of the land use change at the microenvironment beneath tree cover were substantially unbalanced in terms of soil organic carbon stocks. Therefore, results suggest avoiding the soil mechanical disturbance beneath cork oak in the investigated ecosystem to reduce anthropogenic carbon fluxes to the atmosphere
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