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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
Fungi in the environment
No full textFungi are of fundamental importance in the terrestrial environment. They have roles as decomposers, plant pathogens, symbionts, and in elemental cycles. Fungi are often dominant, and in soil can comprise the largest pool of biomass (including other microorganisms and invertebrates). They also play a role in maintenance of soil structure due to their filamentous growth habit and exopolymer production. Despite their important roles in the biosphere, fungi are frequently neglected within broader environmental and microbiological spheres. Additionally, mycological interests can be somewhat fragmented between traditional subject boundaries. This multi-disciplinary volume explores the roles and importance of fungi in the environment. Particular emphasis is given to major research advances made in recent years as a result of molecular and genomic approaches, and in cell imaging and biology. Drawing together microbiologists, mycologists, and environmental scientists, this work is a unique account of modern environmental mycology, and a pivotal contribution to the field
Fungi, ecosystems, and global change
No full textAs decomposers, pathogens, and mutualistic symbionts with plants and animals, fungi play a major role in ecosystem processes including nutrient cycling, bioconversions, and energy flows. Fungi are globally distributed, but different species have distinctive geographical distributions that depend on hosts and climate. Fungal communities are being affected by global change, including climate change, land use change, pollution, pesticides and fertilisers, and movement of biota. Since decomposers, plant and animal pathogens, mycorrhizas and lichens are all affected, there are implications for disease and ecosystem processes. Loss of diversity is a problem at least as large for fungi as for plants and animals, but fungi are not usually a high profile group. Red Lists are being constructed for fungi using IUCN categories, though use of criteria for plants and animals is not always straightforward
Genetics - variation, sexuality, and evolution
No full textGenetics deals with variation and inheritance and forms the basis for understanding why fungi behave as they do. Genetic variations among fungi are considered at the level of the individual, populations, and species, but there are several difficulties in defining fungal individuals. The ability to distinguish self from non-self results from somatic incompatibility mechanisms. Populations comprise assemblages of individuals of a species. The species is the fundamental unit of biological classification, but there are different ways of defining a species, including biological, morphological and phylogenetic, and practical difficulties in delimiting them. Some of the life cycles and sexual processes within the fungi promote outcrossing and others restrict it. Variations between and within species and populations are brought about by microevolution, mutation, selection, gene flow, genetic drift, recombination, transposable elements, horizontal gene transfer, and epigenetics
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
Interactions between fungi and other microbes
No full textThough there are mutualistic relationships between fungi and organisms from other kingdoms, none have yet been described for fungi in nature. Fungi engage in a range of aggressive interspecific interactions, which can occur at a distance or following contact, due to parasitism or production of volatile and diffusible chemicals, including enzymes, toxins and other antifungal metabolites. Interactions between fungi and bacteria are many and varied, and these microorganisms affect each other’s growth, survival and virulence. These effects can be negative, positive or mutualistic. Intracellular viruses are widespread in fungi in all phyla. The host range of a virus type is very narrow, and frequency of infection within a species is variable, but sometimes high. Most viruses cause few or no obvious symptoms, but large beneficial and adverse effects have been reported. Fungi also interact with protists feeding on some and killing others which have ingested them
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
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