1,720,984 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
Kaolin nano-powder effect on insect attachment ability
No full textThe present study investigates under controlled conditions the effect of kaolin particle film on reduction of insect attachment ability. Two economically important polyphagous insect pests characterized by different attachment devices were tested, the Southern green stink bug Nezara viridula (Heteroptera: Pentatomidae) and the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae). We performed traction force experiments with females pulling on treated (covered with kaolin par- ticle film) and untreated (control) natural (leaf surfaces with different morphological traits) and artificial (hydrophilic and hydrophobic glass) surfaces. The data demonstrated that insect adhesion is heavily affected by kaolin particle film in both tested species. The degree of reduction of insect adhesion to the treated substrates compared with the untreated ones differed according to the kind of treated substrate owing to its initial wettability and morphology (presence of trichomes). To unravel the insect adhesion reduction mechanism of kaolin particle film, we evaluated the safety factor for females before and after walking on treated surfaces and analyzed under cryo-SEM the tarsal attachment devices of N. viridula and C. capitata after walking on treated surfaces. We observed contamination by the kaolin nanoflakes in both the smooth pads of the bug and the hairy pads of the fly. The present study can help to better understand the mechanism of action of kaolin particle film and can contribute to develop future physical control barriers against pest insects, particularly relevant owing to the need to reduce the negative impacts of pesticides on environment and human healt
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
Visual and chemical cues in the host plant selection of the melon ladybird Chnootriba elaterii (Coleoptera: Coccinellidae)
No full textPhytophagous insects employ various sensory cues in the host plant location such as visual, olfactory, gustatory, and tactile stimuli, which are perceived by sensory systems and integrated in higher brain centres to trigger the correct behavioural responses. In the present study, the host location process of the oligophagous species Chnootriba elaterii (melon ladybird) is investigated in controlled conditions using both a Y-Tube olfactometer and an open Y-Track olfactometer. Olfactory and visual cues from the host plant act synergistically to lead the ladybirds towards the host plant. Females of C. elaterii are not able to discriminate between host and non-host plants using either olfactory or visual cues alone. Visual cues, particularly those associated with the colour green, are of higher relative importance compared to olfactory cues in the host location process. Green dummy plants made of cardboard represent strong supernormal stimuli for C. elaterii females. The results of the present study can shed light on the host location process of Coccinellidae and can help to develop visual or chemical traps which can be useful in monitoring and controlling this important crop pest of the Mediterranean Basin
Association of the sponge Tethya orphei (Porifera, Demospongiae) with filamentous cyanobacteria
No full textRole of chemical cues in cabbage stink bug host plant selection
No full textThe cabbage stink bugs of the genus Eurydema, encompassing several oligophagous species, such as Eurydema oleracea (L.), are known to be important pests of cabbage, broccoli, and other cole crops in Europe. Despite their economic importance, the knowledge regarding the role of chemical cues in host plant selection of these species is very limited. The present investigation on E. oleracea at the adult stage revealed the use of olfaction in host plant selection of this species and demonstrated with behavioural tests that E. oleracea preferred feeding on wild Eruca sativa, rather than on Brassica oleracea. Moreover, ultrastructural data revealed the antennal sensilla of E. oleracea, encompassing single walled and double walled olfactory sensilla, and electroantennographic recordings revealed their sensitivity to several host plant VOCs from E. sativa and B. oleracea. The data shown in the present research may be useful in the development of semiochemical-based strategies or trap crops for the control of this pest in the field
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
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