1,720,972 research outputs found
Effects of spurge flax (Daphne gnidium L., Thymelaeaceae) extracts on the development and mortality of the elm leaf beetle (Coleoptera: Chrysomelidae)
Spurge flax (Daphne gnidium L., Thymelaeaceae) is an evergreen shrub typical of the Mediterranean flora. It has been traditionally used for centuries in Spain as a control agent of invertebrate pests of crops and cattle. Previuos bioassays performed in our laboratory demonstrated that leaves and ethanolic extracts of D. gnidium showed antifeedant activity on pest species belonging to the orders Heteroptera, Isoptera, Lepidoptera and Coleoptera. The elm leaf beetle, Galerucella luteola Müller (Coleoptera, Chrysomelidae), in Spain represents one of the most important pests of elms (Ulmus spp.) in both river bank forests and urban areas, being responsible for partial or total defoliation of the tree tops. In order to study the effects of spurge flax on G. luteola, different doses of an ethanolic extract of D. gnidium were added to the natural diet (elm leaves) of young larvae. During the development, weight changes, phase durations and mortality rates of each stage were recorded. Results showed that the addition of spurge flax extract to the diet of G. luteola induced: a) a significant increase in the duration of the larval period; b) greater mortality rates for all stages; c) weight reduction of individuals of all stages, including imagoes
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Predictive model for the emergence of Xylotrechus arvicola (Coleoptera: Cerambycidae) in La Rioja vineyards (Spain)
Xylotrechus arvicola (Coleoptera, Cerambycidae) (Olivier) is a polyphagous borer which attacks different woody species in natural habitats in Spain. This coleopteran is also becoming a real impacting pest in several Spanish wine producing territories. Infested vines show adult exit holes, rachitic shoots, a higher incidence of wood fungal diseases and fragility. At the beginning of the 1990s, a heavy increase of infestation was observed in La Rioja vineyards, the only Qualified Guarantee of Origin Region (A.O.C.) in Spain. Due to the endophytic development of the larvae of X. arvicola, adults are the designated target for the integrated management. Therefore, the aim of the present paper was to study the flight period of the pest and to calculate the value of degree-days for the emergence of both sexes from data collected in the field during 2003-2008 in a Tempranillo cultivar in Tirgo (La Rioja). Adult emergences occurred from the end of May to mid-August and a certain degree of protandry was detected. The predictive models obtained for each year fit a sinusoidal curve in all cases, except for males in 2004, when the adjustment was polynomial. The obtained correlation coefficients were considerably high, as the value 0.99 was exceeded in 72% of the cases. These results obtained in La Rioja vineyards suggest that control strategies aimed at the reduction of the adult population of X. arvicola in the view of the integrated management, should be performed between mid-June and the end of July
Author-wise bibliometric analysis based on entropy.
Author-wise bibliometric analysis based on entropy.</p
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