1,721,012 research outputs found
Effects of potential food sources on biological and demographic parameters of the predatory mites Kampimodromus aberrans, Typhlodromus pyri and Amblyseius andersoni
No full textKampimodromus aberrans, Typhlodromus pyri and Amblyseius andersoni are generalist predatory mites important in controlling tetranychid and eriophyoid mites in European vineyards. They can persist by exploiting various non-prey foods when their main prey is absent or scarce. A comparative analysis of the effects of various prey and non-prey foods on the life history of these predators is lacking. In the laboratory, predatory mites were reared on herbivorous mites (Panonychus ulmi, Eotetranychus carpini and Colomerus vitis), a potential alternative prey (Tydeus caudatus) and two non-prey foods, i. e. the pollen of Typha latifolia and the mycelium of Grape downy mildew (GDM) Plasmopara viticola. Developmental times, survival, sex ratio and fecundity as well as life table parameters were estimated. Kampimodromus aberrans developed faster on E. carpini, C. vitis or pollen than on P. ulmi and laid more eggs on pollen than on prey. Low numbers of this predator developed on GDM infected leaves. Tydeus caudatus was not suitable as prey for any of the three predatory mites. Kampimodromus aberrans showed the highest intrinsic rate of population increase when fed on pollen. Developmental times of T. pyri on prey or pollen were similar but fecundity was higher on pollen than on P. ulmi. Typhlodromus pyri had higher intrinsic rates of population increase on C. vitis and pollen than on P. ulmi; E. carpini showed intermediate values whereas GDM resulted in the lowest rm values. Development of A. andersoni females was faster on pollen and C. vitis than on P. ulmi and GDM. Fecundity was higher on pollen and mites compared to GDM. Life table parameters of A. andersoni did not differ when predators were fed with prey or pollen while GDM led to a lower rm value. On a specific diet A. andersoni exhibited faster development and higher fecundity than T. pyri and K. aberrans. These findings improve knowledge on factors affecting the potential of predatory mites in controlling phytophagous mites in European vineyards. © 2012 Springer Science+Business Media B.V
Notes on the phenology and the biology of Tydeus caudatus Dugès (Acari, Tydeidae)
No full textKnowledge on the biology and ecology of the Tydeoidea is limited. Regarding feeding habits, tydeids appear as an unspecialized group. of the families Tydeidae and Iolinidae are frequently observed in vineyards associated with eriophyid Members mites, and feeding on pollen or fungi has also been reported. Tydeus caudatus Dugès is one of the most common tydeid species occurring in Italian vineyards. Tydeus caudatus populations can persist and increase in vineyards when eriophyid levels are low, suggesting that its diet includes non-prey food sources. In this paper, the suitability of pollen and grape downy mildew as food sources for T. caudatus has been explored. Some findings on the phenology of T. caudatus in vineyards are also reported
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
Relationships between plant pathogenic fungi and mites in vineyards: implications for IPM
No full textIn this paper we summarize the results of studies aimed at investigating the relationships between fungal diseases and mites occurring in European vineyards. Most of the data originated from observations carried out in commercial and experimental vineyards in north-eastern Italy. Grapevine downy mildew, Plasmopara viticola, and grape powdery mildew, Uncinula necator, are the most significant grape diseases in several viticultural areas in Europe and throughout the world. The spread of downy mildew in European vineyards may increase the abundance of some species of Phytoseiidae and Tydeidae. Amblyseius andersoni responded clearly to the spread of downy mildew symptoms, an effect also observed, but at lower magnitudes, for Typhlodromus pyri and Kampimodromus aberrans. The beneficial effect of downy mildew on the survival, development and reproduction of phytoseiids and tydeids has a clear impact on their population dynamics. Downy mildew effects varied among phytoseiids, being more relevant for A. andersoni than for T. pyri. These interactions may have implications for IPM because T. pyri is more effective than A. andersoni in controlling phytophagous mites in vineyards. The role of powdery mildew as a food source for A. andersoni and T. pyri was less pronounced than that of downy mildew. The capacity of generalist predatory mites to persist in perennial ecosystems contributes to the successful biological control of phytophagous mites. In vineyards, the persistence of generalist predators in the absence of prey may be improved by their feeding on various food sources. Pollen is probably the most important food source in spring and early summer, whereas mildews increase in importance in late summer. Predatory mite persistence is largely affected by pesticide use. The results of our studies showed that downy mildew availability mediates the effects of fungicides on predatory mites because it represents an alternative food for them. Moreover, downy mildew can enhance the recovery of predatory mite populations after pesticide applications
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
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