1,721,133 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
Mechanical application of orius laevigatus nymphs for the control of Frankliniella occidentalis in greenhouse crops
Full text linkThe development of improved technology for use of beneficial organisms in greenhouse crops includes mechanical application methods to that can reduce labour costs compared to manual application while preserving the quality of the applied natural ene-mies. A pneumatic distribution system, verified as effective in previous study with mites (Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henriot), was tested for application of the predatory bug Orius laevigatus (Fieber). Laboratory and field tests were used to assess the efficiency of mechanical distribution of nymphs of O. laevigatus. The efficiency of mechanical distribution was evaluated comparing the biological parameters of the predator (survival, fecundity, fecundity rate and lon-gevity) dispensed mechanically with to those following manual distribution. Nymphal survival immediately after and 10 days after the dispensing was calculated as proportion of nymphs reaching adulthood. We found that mechanical applications caused a reduction of predator survival in comparison to manual sprinkling of 21% and 36% immediately after and 10 days after the dis-pensing, respectively. The causes of the reduced survival from mechanical application were attributed to the combined effect of the extraction system and the velocity of airflow that transports the predator. Moreover, the biological parameters of adult females that survived mechanical distribution as nymphs, showed no significant differences compared to the same following manual dis-tribution. In the greenhouse test, the mechanically released nymphs of O. laevigatus were as effective as those manually released in controlling Frankliniella occidentalis (Pergande) in a cucumber crop. Consistently, the yield and quality of cucumber fruits did not show differences in the mechanical vs. manual application. Mechanical application time was significantly lower compared to manual application, determining a 5.5 higher effective work capacity compared to traditional manual distribution
Evaluation of lethal and sublethal effects of laminarin on the green peach aphid, Myzus persicae, under extended laboratory conditions
No full textRecent studies have opened the way for using elicitor-induced resistance in plants as a method to control arthropod pests. In this study, 1,3-beta-glucan laminarin, an elicitor of disease resistance in plants, was tested on the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), on peach [Prunus persica (L.) Batsch, Rosaceae] plantlets and evaluated its effects on short-term mortality and population growth. Laminarin exposure did not affect aphid survival in the short term; however, laminarin-treated peach plants sustained fewer nymphs and adults in comparison with the control. Aphid populations on plants treated with laminarin declined significantly over the sampling period compared to the control. Moreover, the demographic parameters net reproductive rate (R-0), finite rate of increase (lambda), and intrinsic rate of increase (r(m)), all showed decreasing trends in aphid populations reared on laminarin-treated plants. The decline in aphid populations exposed to laminarin seemed to mainly be linked to reduced adult survival, slower nymph development, and lower nymph survival and only marginally to changes in reproduction outcome. Changes in gene expression causing the final production of defence chemicals by peach plants may contribute to explaining the results. However, potential direct effects of laminarin on M. persicae feeding activity and probing behaviour cannot be ruled out. This study provides evidence that, although laminarin did not display insecticidal activity in the short term, this elicitor caused sublethal effects, significantly reducing aphid populations
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
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
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
Effects of temperature and host on the pre-imaginal development of the parasitoid Diglyphus isaea (Hymenoptera: Eulophidae)
No full textThe development of Diglyphus isaea (Walker), a parasitoid of leafminers, was studied under laboratory conditions at four constant temperatures (15, 20, 25, and 30degreesC on the hosts Liriomyza trifolii (Burgess) and Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae). Parasitoid developmental time was found to be inversely related to temperature. At 15 degreesC, D. isaea took about 28 days to complete its development on L. huidobrensis and about 27 days on L. trifolii. In comparison, at 20degrees C developmental time dropped to half on both species and the same happened fro m 20 to 30degreesC. At 25degreesC, parasitoid development was complete after about 10 days. At all tested temperatures and on both host species, the length of pupal stage of the parasitoid was slightly shorter than the egg + larva period. Linear regression and the Logan model were used to describe the relationship between developmental rate and temperature. For egg to adult development, female D. isaea required 161.8 degree-days (DD) above the theoretical threshold of 9.2degreesC-on L. trifolii and 165.0 DD above 9.3degreesC on L. huidobrensis,and males required 151.4 DD above 9.5degreesC on L. trifold and 157.4 DD above 9.3degreesC on L. huidobrensis. Optimum temperatures for total female and male development on L. trifolii were 33.3 and 32.3degreesC, and on L. huidobrensis 32.6 and 31.0degreesC, respectively. The effects of host, sex, and temperature on parasitoid size were studied. Significant sex-temperature, host-temperature, and host-sex-temperature interactions were found. The host species was found to affect female parasitoid size differently based on temperature. (C) 2002 Elsevier Science (USA). All rights reserved
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