1,720,992 research outputs found
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
Major vegetation management issues in Queensland: tree clearing, grazing and weeds
No full textHabitat alteration is the major vegetation management issue in Queensland. Alteration takes many forms: from physical alteration through clearing, to composition and productivity changes due to grazing, through to complete species replacement by exotic species. While the issue of tree clearing is widely debated in scientific circles and the general public, grazing and weed management are much less prominent issues. Consequently, the debate about vegetation management is unbalanced. Attempts to protect the environmental and production resources of Queensland must involve the analysis of all issues if sound management practices are to be developed. The history, current issues and future trends for each of the forms of habitat alteration are discussed
Environmental Weed risk assessment in the Wet Tropics: addressing problems of invasive alien species as a major threat to landscape integrity and health
No full textThe issue of alien plant species invasions of the Wet Tropics bioregion was examined, and the implications for World Heritage management considered. The paper presents a brief review of Risk Assessment Systems (RASs) currently applied or being developed, with a view to formulating a robust system to screen alien species that have naturalised within the bioregion. The rationale behind the proposed Wet Tropics environmental weed RAS, which was derived from existing systems, is considered prior to its application as a screening tool. A list was compiled comprising 508 taxa of exotic (alien) plants that have established self-maintaining populations within the Wet Tropics bioregion. The paper reports on a preliminary ranking, employing the proposed RAS, of 7 aquatic and 50 terrestrial weed species. The six highest ranked species included Annona glabra (a weed of national significance or WONS) and the introduced forage legume Leucaena leucacepha/a; followed by the highly invasive Cliromolaena odorata (a very high priority declared plant); Miconia calvescens (similarly classified); Hymenachne amplexicau/is (a ponded pasture species now classified as a WONS); and Sphagneticola trilobata (a ground-cover species formerly used as- a _bank stabiliser but under consideration for declaration as a plant requiring control in environmentally sensitive areas under new State legislation). Consideration was also given to weed management issues, particularly with respect to some of the worst environmental weeds, and recommendations for further research are presente
Impacts of exotic weeds on wildlife
No full textIn the last two decades, there has been an increasing realisation worldwide that invasions by exotic weeds are second only to landscape destruction through clearing and development as a threat to biodiversity. Recognition of the massive impact of exotic weeds is only slowly filtering down to on-ground land managers and the general public, where there is still a view that all plants are more or less equally desirable. The major impact of exotic weeds is displacement of the native flora. Displacement directly reduces the population of native plant species, which may become endangered or extinct in all or part of their ranges.
There are also very serious flow-on effects to the wildlife. Every native plant has a large associated fauna feeding on it, but most weeds contain bitter-tasting and/or poisonous chemicals that make them unsuitable for generalist herbivores such as wallabies and possums. The populations of these animals therefore fall in proportion to the replacement of the native flora by unpalatable exotic weeds. The arthropod fauna (mites and insects) are often highly species-specific, and also cannot transfer to the invading weed. Replacement of native vegetation by exotics thus results in an enormous reduction in the arthropod fauna, both in diversity and actual numbers, and unrecorded local and widespread extinctions are undoubtedly happening as a result.
Other flow-on effects on wildlife result from the absence in weeds of particular features of native plants, such as nectaries. For example, nectar-feeding birds, bats, and gliders will be seriously affected by the replacement of eucalypts, grevilleas and bottlebrushes by exotic trees or shrubs. Conversely, the exotic trees camphor laurel and Brazilian pepper produce abundant small fruit, resulting in increases in fruit-eating bird populations, with flow-on effects to their predators and competitors.
The reduction in arthropod numbers has further flow-on effects on parasitoid and predator species, including spiders, wasps, lizards, birds and insectivorous mammals. These feed on a variety of prey, so are not critically affected by the loss of any single species, but are affected by the loss of groups of species and the overall fall in abundance of invertebrates. Populations of species in higher trophic levels can therefore be expected to fall in proportion to the replacement of native flora by exotic weeds.
In summary, invasion of an ecosystem by exotic weeds has enormous flow-on effects on the wildlife, and these effects need to be more widely appreciated and understood
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
The assessment of riparian vegetation as an indicator of stream condition, with particular emphasis on the rapid assessment of flow-related impacts
No full textRiparian systems have an intimate connection with in-stream systems and appear to be sensitive indicators of environmental change. Riparian attributes should therefore contribute candidate metrics in any comprehensive measure of stream condition and change, yet assessment of the condition of riparian vegetation in monitoring programs aimed at ascertaining river ecosystem health is not well advanced. This paper reviews methodologies aimed at assessment of the contribution of riparian vegetation to river health, including integrated assessment protocols employed by government agencies, techniques developed from particular research perspectives as well as within multidisciplinary approaches to riverine condition assessment. While some approaches currently in use hold promise, there is no suitable protocol for rapid riparian vegetation assessment that can be incorporated into a multi-metric index of stream condition, or used to assess the impacts of flow regulation, in particular, on ecosystem integrity. We derive a standard multi-metric approach to rapid assessment of riparian vegetation as distinguished from the more detailed methods applied in longer term research programs. Our approach is configured to assist in determining stream condition, the extent of flow regulation impacts and to provide positive and negative benchmarks against which water infrastructure development can be assessed i n a manner to progress ecological sustainability in Queensland streams
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