1,720,957 research outputs found
Factors affecting spider prey selection by Sceliphron mud-dauber wasps (Hymenoptera: Sphecidae) in northern Italy
No full textPredatory habits of apoid wasps are well documented for many species, revealing a choice of prey ranging from generalist to specialised, but few studies tested the degree of specialisation when compared with the availability of prey in the environment. In a study carried out in northern Italy, nests of the mud-dauber wasps Sceliphron spirifex L. and S. caementarium Drury were collected to obtain
the spider prey of the wasps, and a survey of the nesting area was performed to ascertain frequency of the available spider prey species in the environment. Wasps preyed preferably upon spiders of the
family Araneidae. Adult preferred spider prey size ranged from 4 to 6 mm in length. The factor which most affected prey selection was the ecology of the spiders, with orb-web spiders being the preferred
prey despite the fact that terricolous, non-web groups were the most abundant in the locality. Sex (female, male or juvenile) of prey was also important in prey selection: juvenile spiders were the most preferred even though males and females were equally and most abundant (respectively). Sceliphron
spp. seem almost to be specialised rather than generalist predators. These results suggest that the terms ‘generalist’ or ‘specialised’ should not be applied to predators solely on the basis of prey collected from wasp nests, but should also be related to local prey availability
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
Temporal relationship between the prey spectrum and population structure of the weevil-hunting wasp Cerceris arenaria (Hymenoptera: Crabronidae)
No full textSpecialized predators must face the problem of reductions in resources, and variations in the prey spectrum can be expected to be reflected in predator population traits. Cerceris arenaria L. (Hymenoptera: Crabronidae) is a solitary wasp that hunts weevils (Coleoptera: Curculionidae), with the individual range of prey sizes varying
according to the size of the female wasp. A nest aggregation in Castiglione d'Adda, northern Italy was studied in 1997-1999, 2001, 2003, and 2005 in order to investigate variations in the prey spectrum across several years, while a 2nd aggregation in Castell'Arquato was investigated in 2001 to look for possible differences in prey selection between the 2 populations. The captured weevils belonged to 23 species. At both sites, the most often collected genera were Otiorhynchus Germar and Sitona Germar, which include several pests of cultivated plants. The prey spectrum (in terms of taxonomic identity and specimen frequency per species) varied among the years of study in Castiglione d'Adda, with Sitona spp. being more abundant in 1997-1999 and Otiorhynchus spp. in 2001, 2003, and 2005. According to this temporal shift in the prey spectrum, the annual average prey size increased from 1999 to 2005. Annual average prey size in Castiglione d'Adda was always lower than that in Castell'Arquato, where the frequency ratio of Otiorhynchus/Sitona was higher than that in Castiglione d'Adda. Prey size and the frequency ratio of Otiorhynchus/Sitona in Castiglione d'Adda were negatively correlated to the wasp population size, and the average wasp size increased when the frequency of
larger prey increased. We concluded that interactions between extrinsic (prey availability) and intrinsic (wasp
size distribution) factors may strongly influence fluctuations and persistence of specialized predatory wasp populations
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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