1,720,970 research outputs found
Observation of a Leucistic Brown Noddy \u3ci\u3eAnous stolidus\u3c/i\u3e in Tetiaroa, French Polynesia
No full textWe observed a leucistic Brown Noddy Anous stolidus on the atoll of Tetiaroa in French Polynesia. This individual was mostly light grey, similar in coloration to a Blue Noddy Anous ceruleus. To the best of our knowledge, this is the first report of a Brown Noddy with such plumage. Brown Noddies and White Terns Gygis alba were particularly aggressive towards the aberrantly colored Brown Noddy
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
Larval Adaptation to Salinity Shock in Cane Toads (Rhinella marina) From Coastal French Guiana
No full textMany habitats not only differ in mean conditions but also in the degree to which these conditions fluctuate through time. Therefore, local adaptation to both mean abiotic conditions and habitat variability can enhance organismal viability. Within their native range in French Guiana, cane toads (Rhinella marina) inhabit both coastal beach and inland rainforest habitats. We surveyed breeding pools to quantify abiotic conditions. Breeding pools in coastal habitats exhibited high salinity levels and intermittent seawater inflow with rapid increases in salinity. Breeding pools in inland habitats had low, stable salinity levels. Salinity shock only caused mortality within coastal environments. To determine whether larvae were locally adapted to salinity conditions, we raised the offspring of toads collected from 14 inland and coastal sites under a range of salinity levels. We also mimicked seawater inflow by exposing larvae from 15 clutches to sudden increases in salinity to measure their tolerance to salinity shock. Although coastal and inland tadpoles performed similarly under constant salinity, tadpoles from coastal habitats survived a rapid increase in salinity better than did conspecifics from inland habitats. The capacity to tolerate variable environments and adapt to local conditions may have contributed to the cane toad's translocation success
Spatial ecology of cane toads (Rhinella marina) in their native range: a radiotelemetric study from French Guiana
No full textLike most invasive species, cane toads have attracted less research in their native range than in invaded areas. We radio-tracked 34 free-ranging toads in French Guiana, a source region for most invasive populations, across two coastal and two rainforest sites. Coastal toads generally sheltered in pools of fresh or brackish water but nocturnally foraged on beaches, whereas rainforest toads sheltered in forested habitats, moving into open areas at night. Over five days of monitoring, native toads frequently re-used shelters and moved little between days (means = 10–63 m/site) compared to invasion-front toads from Australia (~ 250 m). Larger toads moved less between days, but displaced in more consistent directions. At night, foraging toads travelled up to 200 m before returning to shelters. Foraging distance was related to body condition at coastal sites, with toads in poorer body condition travelling farther. Rain increased the probability of coastal toads sheltering in the dry habitats where they foraged. Dispersal and rainfall were lower at coastal sites, and the strategies utilized by coastal toads to minimize water loss resembled those of invasive toads in semi-desert habitats. This global invader already exhibits a broad environmental niche and substantial behavioural flexibility within its native range
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