1,720,997 research outputs found
Evaluation of Possible Reproductively Mediated Character Displacement in the Crayfishes, Orconectes rusticus and O. sanbornii
Get PDFAuthor Institution: Department of Biological Sciences, The Florida State UniversityOrconectes rusticus is replacing several species of crayfishes in north-central and northeastern North America, including O. sanbornii in Ohio. Recent evidence suggests that the species replacements may be driven by asymmetrical reproductive success favoring 0. rusticus. Nonetheless, some sympatric associations appear locally persistent. Because crayfish demonstrate size-assortative mating and there is a disparity in the sizes of the species, further divergence in the sizes of the species in sympatry could enhance reproductive isolation, ultimately providing a mechanism for character displacement. To test this hypothesis the size differentials between crayfish collected from allopatric and sympatric populations in east-central Ohio were compared with expected differences. The possibility of clinal variation in size was addressed by comparing crayfish sizes along a continuous allopatric-sympatric-allopatric species gradient within one stream. The initial character displacement hypothesis was not substantiated by comparisons of allopatric and sympatric populations within or among streams for male or female 0. rusticus or male 0. sanbornii. However, female 0. sanbornii size distributions were consistent with unilateral character displacement
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
The 6th International Conference and Workshop on Lobster Biology and Management: An Introduction
Get PDFEvery three years or so, the International Conference and Workshop on Lobster Biology and Management (ICWL) brings together lobster scientists, fishery managers, and industry representatives from around the world for a week of scientific presentations, workshops, and discussions on lobster biology and management. The first ICWL was held in Perth, Australia, in January 1977. Its purpose was to bring together a small group of lobster researchers from the USA and Australia to discuss common issues and themes. That initial workshop spawned a continuing series of meetings that have become the international lobster conference for scientists—the equivalent of an international congress meeting. The second conference was in St. Andrews, Canada, in 1985; the third in Havana, Cuba, in 1990; the fourth in Sanriku, Japan, in 1993; and the fifth in Queenstown, New Zealand, in 1997. The number of participants and the international representation at the conference has grown from 34 scientists and managers from 6 countries at the first meeting to over 200 participants from 25 countries at the September 2000 meeting in Key West, Florida (USA). All told, 126 oral presentations and 43 poster presentations took place during the five-day meeting
Community Responses to Variable Predation: Field Studies with Sunfish and Freshwater Macroinvertebrates
Get PDFThe impact of variable predation by bluegill sunfish on macroinvertebrate prey in a North Florida lake is examined. Variable predation may occur in many systems and may contribute substantially to the spatial heterogeneity, temporal inconstancy and species composition of prey communities.
Patchy, temporally variable predation characterized middepth and deep lake habitats, whereas in the shallow zone predation was relatively constant and homogeneous. Predation varied significantly every 2-4 wk in the mid-depth zone, but varied little between consecutive weeks or days. Caging experiments revealed that variable predation altered prey community composition and increased the mean size and size range of some prey (e.g. Odonata) as compared to the constant predation treatment. Prey abundances also appeared more heterogeneous among cages (patches) and varied more temporally under a variable predation regime. However, total prey abundance, species abundance, and within-patch spatial heterogeneity did not differ among predator treatments. In general, the macroinvertebrate community exposed to variable predation more closely approximated the natural middepth zone community than that from the constant predation regime. Previous studies of fish predation on macroinvertebrate communities have concentrated on shallow littoral habitats, but these result suggest that conclusions drawn from shallow habitats may not be representative of all lake zones. Variable predation may occur in many systems, and may contribute substantially to the spatial heterogeneity, temporal inconstancy, and species composition of prey communities
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
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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