1,720,972 research outputs found
Tree ring research may understand climate change / Nur Idzhainee Hashim and Rob Marrs
Full text linkDendrochronology is the scientific discipline of determining the relationship between tree growth and climate, and is determined using the annual growth rings. This provides a potential method for monitoring climate change. Climate usually acts as a major factor influencing the tree growth. Here, the effects of climate of a conifer species was assessed in relation to measured climatic variables. Tree cores of Scots Pine (Pinus sylvestris) were sampled from a forestry plantation at Hordron Edge, Derbyshir. Standard dendrochronological techniques were used to collect, prepare and measure tree – ring width increments. Forest ecosystems have been recognized as an essential component of the biosphere (Hooper et. al., 2005). One of the most widely–distributed conifers tree in the world is Scots Pine (P. sylvestris) (Royal Forestry Society, 2014). It is found naturally in Great Britain mainly in the Scottish Highlands but is planted extensively throughout the country. It is evergreen, reaching heights of 25 m to 45 m when mature, and is classified as softwood which makes it easy to extract tree cores
Tree – ring growth response of scots pine (Pinus Sylvestris l.) to climate change / Nur Idzhainee Hashim, Rob Marrs and Nor Hanisah Mohd Hashim
Full text linkDendrochronology is the scientific discipline of determining the relationship between tree growth
and climate , and is determined using the annual growth rings. This provides a potential method for
monitoring climate change. Climate usually acts as a major factor influencing the tree growth. Here, the effects of climate of a conifer species was assessed in relation to measured climatic variables. Tree cores of Scots Pine (Pinus sylvestris) w ere sampled from a forestry plantation at Hordron Edge, Derbyshire to determine the relationship between ann ual growth incremen t and four climate
variables (maximum temperature, minimum temperature, grass minim um temperature and rainfall). Standard dendrochronological techniques were used to collect, prepare and measure tree–ring width increments . Climate data were derived from the British Atmospheric Data
Centre (BADC) from 1921–2013. Tree-ring widths were as cross referenced to the climate data to enable growth dynamics of (Pinus sylvestris) to be investigated. In this study there was no significan t correlation between growth and climatic variables; overall average mean sensitivity ( m s ) was 0.28 mm, only five of the 20 trees were sensitive to climate ( m s >0.3) with the other 15 trees being
complacen t ( m s <0.3). The growth incremen t index p ortra yed a cyclic pattern of tree growth through time with peaks (fast growth) and troughs (slow growth) throughout the period. There were no significan t first-order relationships found between tree growth indices and any of the four climatic variables tested. This result suggests that cl ima t ic variables were not significan t in controlling tree growth at this site
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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