1,721,160 research outputs found
Progetto LIFE P.P.P. 4 I.RE.COLL – “RICICLOLIO” una sinergia tra pubblico e privato per l'ambiente e per un immagine positiva della chimica
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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
The power of dynamic asset allocation
No full textThis article re-assesses the evidence and practical relevance of asset returns’ long-horizon predictability, investigating whether practitioners can profitably exploit predictability patterns by using relatively simple, dynamic asset allocation strategies. The analysis shows forward-looking models that rely on steady-state equations for equities and initial yields to maturity for bonds are far better predictors of markets’ long-run direction than is the industry’s conventional approach, which involves extrapolating from historical averages. Using a long-term U.S. sample from 1926 to 2010, the authors find that predictability translates into significantly better risk-adjusted performance from dynamic asset allocation strategies that rely on forward-looking inputs
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
Biology, spatial distribution and population dynamics of Lepidotrigla cavillone (Pisces: Triglidae) in the Central Tyrrhenian Sea
No full textSpecimens of Lepidotrigla cavillone (the large-scaled gurnard) were collected in the Central Tyrrhenian Sea during trawl surveys carried out in April-May and September 1985, 1986, 1987, 1994, and in October 1995. The species was fished between 30 and 200 m depth. A significant size-depth relationship (p < 0.001), was observed for juveniles (S.L. < 7 cm) and adults: the former migrated deeper from the coastal nursery, at the end of the first year of life; the latter moved shallower toward the spawning grounds at 60-100 m depth. Principal Component Analysis, indicated gonadal development as the main factor affecting L. cavillone depth-size relationships. Mature females were observed with significantly higher abundance (p < 0.001) at depth of 80-100 m. Large-scaled gurnards accomplished more than half of their growth during the first two years. Reduction of growth coincided with attainment of sexual maturity. An increase of the mesh size towards the legal size may bring the age at first capture from 1.5 years up to the age of first maturity (second year) improving current Y/R
Growth and reproduction of Xyrichthys novacula (Pisces : Labridae) in the Mediterranean Sea
No full textMediterranean razorfish, Xyrichthys novacula, were collected between July and December in a sandy bay of Ponza Island (Central Mediterranean Sea) to investigate the effects of reproduction and growth patterns on sexual inversion processes and haremic territoriality The minimum body size of males decreased from 17 cm in July to 15 cm (T.L.) in October as a consequence of the sexual inversion after reproduction. Females showed a reproductive peak in August using both the Holden and Rait scale and the gonodosomatic index. The gonads of males were small, on average only 0.14% of total body weight. The proportion of body weight devoted to gonads did not change with male size. This is probably a consequence of the haremic mating system of the species which reduces sperm competition between males. A new coloration phase for females was introduced in addition to the three already described in the literature. Individuals of each age class are characterised by different coloration patterns. This chromatic feature of the species allows dominant males to recognize the age of females and consequently to choose during harem formation the older and larger specimens able to produce a larger number of offspring
Feeding ecology of Mediterranean razorfish Xyrichthys novacula in the Tyrrhenian Sea (Central Mediterranean Sea)
No full textThe stomach contents of 196 razorfish (Xyrichthys novacula), collected in the Tyrrhenian Sea (Ponza Island, Italy) between July and December 1994, were examined in order to assess the diet and to analyse size-related dietary variation of the species. The diet of X. novacula showed a strict relationship with well-sorted fine sand (SFBC) benthic species, mostly Mollusca and Echinodermata, as pointed out by the analysis at the specific level of the stomach contents. Mollusca Pelecipoda, essentially Acanthocardium tuberculatum and Echinodermata, with Echinocardium cordatum, made up 90% of the volume of prey of X. novacula. Mysidacea and Gastropoda were frequent but volumetrically less important. The study showed that male and female X. novacula were not effectively segregated by trophic dimension in the study area. The niche overlap between males and females in prey composition was pronounced, as evidenced by the significantly high values of Schoener's index with larger males that showed a greater tendency towards predation of large prey. The increment in length (L.I.) in males, despite a decrease in the percentage body weight increment (B.W.I.), could represent the result of a male reproductive feature: the lack of sperm competition allows the males much more energy to devote to growth than do that of the females of this species
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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