1,721,057 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
Population structure of Aedes albopictus (Skuse): the mosquito which is colonizing Mediterranean countries
No full textMultilocus electrophoresis analysis has been used to study the genetic structure of 18 populations of Aedes albopictus newly introduced to Italy, in comparison with two populations in the United States, four in Japan, and four in Indonesia. Allozyme analysis revealed that 15 out of the 18 studied loci were polymorphic among the 28 populations. No significant deviations from Hardy-Weinberg equilibrium were found at polymorphic loci. High genetic affinity was observed between the Italian populations and those from the United States and Japan. The analysis of variance in allele frequencies showed that variance among subpopulations accounted for most of the total variance, suggesting that isolation of the Italian populations is not related to distance. Analysis of linkage disequilibrium using Ohta's method shows that the variance in the frequency of allele combinations could be explained by the action of the genetic drift which accompanies the establishment of new populations. The colonization process of Ae. albopictus in Italy is following a trend similar to that previously observed in the U.S.A., probably because both infestations derive from several successive introductions, each with large numbers of individuals
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
Optimisation of Embedded Generation Sizing and Siting by using a Double Trade-off Method
No full text
Improving insect pest management through population genetic data: a case study of the mosquito Ochlerotatus caspius (Pallas)
No full text1. Rationalizing the use of chemicals in pest control programmes is a fundamental goal that is aided by the knowledge of patterns of population connectivity and historical demography. 2. In this study, we used both mitochondrial and nuclear markers to investigate the genetic structure and diversity of the northern Italian populations of Ochlerotatus caspius, a mosquito of great public health and economic impact in Mediterranean countries. 3. A substantial genetic homogeneity was found among populations, with no association of pairwise population differentiation with the geographic distribution or the environmental heterogeneity of the breeding sites. 4. On a regional scale, we hypothesize a historical demographic expansion, probably associated with late Pleistocene palaeoclimatic events. Furthermore, our results suggest that ever since the expansion event, an extensive gene flow is still the major evolutionary force shaping the overall genetic pattern observed. 5. At a local geographic scale, evidence of recent growth in the size of the population was found in several sites. The increased availability of large breeding sites offered recently by rice paddies seem to have played a major role in giving rise to the observed demographic expansions. Indeed, these sites have become more numerous and undergone changes in the management technique (increased number of dry/flood cycles), which enhanced their suitability as breeding habitats. 6. Synthesis and applications. The migration pattern among populations of Oc. caspius in northern Italy appears to be high enough to maintain an extensive genetic homogeneity. Control programmes on a small geographic scale are thus unlikely to be effective. The modern agronomic techniques and the growth of rice paddies seem to have played a role in the recent demographic history of the species in the Po plain. Therefore, satisfactory control programmes should: (i) be focused mainly on rice paddies as breeding habitats; (ii) favour agronomical techniques involving a reduced number of dry/flood cycles; (iii) be carried out on a wide (regional) geographic scale; and (iv) monitor periodically the susceptibility of populations to the compounds used in control campaigns and adopt strategies aimed to avoid the possible spread of resistance alleles
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