1,721,003 research outputs found
Transgenic insecticidal crops and natural enemies: A detailed review of laboratory studies
Get PDFThis review uses a data-driven, quantitative method to summarize the published, peer-reviewed literature about the impact of genetically modified (GM) plants on arthropod natural enemies in laboratory experiments. The method is similar to meta-analysis, and, in contrast to a simple author-vote counting method used by several earlier reviews, gives an objective, data-driven summary of existing knowledge about these effects. Significantly more non-neutral responses were observed than expected at random in 75% of the comparisons of natural enemy groups and response classes. These observations indicate that Cry toxins and proteinase inhibitors often have non-neutral effects on natural enemies. This synthesis identifies a continued bias toward studies on a few predator species, especially the green lacewing, Chrysoperla cornea Stephens, which may be more sensitive to GM insecticidal plants (16.8% of the quantified parameter responses were significantly negative) than predators in general (10.9% significantly negative effects without C. cornea). Parasitoids were more susceptible than predators to the effects of both Cry toxins and proteinase inhibitors, with fewer positive effects (18.0%, significant and nonsignificant positive effects combined) than negative ones (66.1%, significant and nonsignificant negative effects combined). GM plants can have a positive effect on natural enemies (4.8% of responses were significantly positive), although significant negative (21.2%) effects were more common. Although there are data on 48 natural enemy species, the database is still far from adequate to predict the effect of a Bt toxin or proteinase inhibitor on natural enemies
Cry toxins and proteinase inhibitors in transgenic plants do have non-zero effects on natural enemies in the laboratory: Rebuttal to Shelton et al. 2009
Get PDFWere-emphasize thatwehave not claimed nor have we implied that laboratory data should be used by themselves to characterize the risks of Cry toxins an PIs to natural enemies. We are concerned that only limited inferences can be drawn by a risk assessment process that relies only on laboratory data to make critical initial decisions about risk. We believe that sound generalizations from the laboratory data concerning the responses to genetically modified plants by natural enemies will emerge as this literature is explored in detail. Just as there are not 10 million different types of population dynamics (Lawton 1992), there are not 10 million different types of responses to GM plants. In our paper, we pointed out that these laboratory data paint a more complex picture than hypothesized by Romeis et al. (2006b) and Shelton et al. (2009). The criticisms of Shelton et al. (2009) of our statistical methods do not stand up to scrutiny and do not invalidate one of our main conclusions: existing Cry toxins and PIs have nonzero effects on natural enemies in the laboratory that need to be understood better. We encourage the reader to critically examine their claims in light of the evidence and explanations given in our original paper (Lövei et al. 2009) and the additional clarifications presented here. To close on a positive vein, we note several important findings in our paper (Lövei et al. 2009) that were not disputed by Shelton et al. (2009). These include that (1) the data support only limited generalization about the responses of natural enemies to Cry toxins and PIs; (2) there is an overemphasis on five natural enemy species, although the literature is expanding in scope; (3) tests have been conducted in only a few countries; (4) the Cry toxins that have been studied are mainly Cry1Ab, Cry1Ac, and to a lesser extent Cry3Bb, and other commercialized Cry toxins are under- reported. In addition, we found (Lövei et al. 2009) that (5) parasitoids may be more sensitive than predators to the effects of both Cry toxins and PIs, (6) PIs seem to affect natural enemies more than Cry toxins, and (7) Cry toxins and PIs can have beneficial effects on natural enemies. © 2009 Entomological Society of America
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
No full textWe 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
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