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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
Modifications over years of volatile compounds and agronomic features in a Sicilian Clary sage biotype.
No full textClary sage is a biennial native to Mediterranean area, spontaneous and often ubiquitous in many environments of inner Sicily. The large white-pinkish flowers are used, besides for ornamental purposes, for extracting a strongly-scented essential oil largely used by perfume industries. This work has been carried out with the aim to observe over several years the behaviour of a Sicilian Clary sage biotype, grown on experimental plots laid out in Sparacia (Cammarata - AG - Sicily). For this purpose seeds of Clary sage collected from a wild population growing in Pietraperzia (EN) were sown in experimental plots each year for seven consecutive years (from 1998 to 2005). Since Clary sage is a biennial, the observations on plants have been carried after each flowering time, i.e. after each second year from sowing. In this work the results of biometrical and chemical data collected on plants are shown. The plant has shown a strong aptitude to reflowering after each collection time, and the oil extracted from the flowers showed excellent quality characters. The oil extracted from the leaves had a composition quite different from that obtained from the flowers, being characterized by noticeable amounts of Germacrene-D. The qualitative characters of oil obtained from both flowers and leaves did not show a significant variability from year to year, and the crop seemed to react very well to the repeated cultivation for many consecutive years on the same site. This strong suitability, and the low labor cost required from its cultivation let foresee excellent perspectives for the introduction of the Clary sage in the Mediterranean cropping systems
Characterization of an Italian biotype of clary sage (Salvia sclarea L.) grown in a semi-arid Mediterranean environment
No full textAn Italian spontaneous biotype of clary sage (Salvia sclarea L.) was evaluated for its suitability to be cultivated in a semi-arid area and for the influence of these growth conditions on the essential oil composition. Seeds gathered from a spontaneous biotype were sown directly in the field, using a seeding density calculated to achieve a plant population of 7 plants/m2. Essential oils from the inflorescences and leaves of plants harvested at full flowering and early seed ripeness stages were obtained by steam distillation and characterized by GC and GC-MS. The plants showed a good tolerance to the semi-arid growth conditions, yielding more than 700 flowers/plant and about 21 g seeds/plant. Relevant qualitative and quantitative differences were detected between the essential oils from the inflorescences and leaves, the former being characterized by a high content of linalool (26-29%) and linalyl acetate (35-53%) and the latter only by sesquiterpenes, with germacrene D as the main compound (68-69%). Inflorescences at full flowering stage were richer in linalool, α-terpineol and germacrene D, showing a lower content in linalyl acetate in comparison with those collected at early seed ripeness. The development stage did not influence the oil composition of leaves
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
Factors influencing anthocyanin content in red cabbage (Brassica oleracea varcapitata L f rubra (L) Thell)
No full textIn North and Central Italy an experiment was conducted for two consecutive years to optimise the anthocyanin yield of red cabbage. Two hybrids ('Roxy' and 'Gradur') were grown under a factorial combination of increasing rates of potassium sulphate (0, 50, 100kg K ha-1) and superphosphate (0, 39, 78kg P ha-1) applied before planting. Cabbages were transplanted at the beginning of August and harvested in winter. Anthocyanins were extracted from cabbage heads with HCl in methanol (1% v/v solution) and quantified by absorption spectrophotometry at 530 nm. Results showed that red cabbage can give high yields of anthocyanins (more than 90kgha-1) which are characterised by strong acylation and therefore, presumably, by good stability. However, differences over sites and years were marked. In the first year, yields in North Italy were reduced by a heavy infection of soft rot disease. The choice of variety, linked to a different anthocyanin content in the heads, appeared to be the major factor for a successful crop. P and K fertilisation had only a small influence. On clay soils in Central Italy the highest rates of both elements had a negative effect on the anthocyanin concentration in cabbage heads. © 2002 Society of Chemical Industry
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
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