1,720,957 research outputs found
Seed colour and post-fire bird predation in a Mediterranean pine forest
No full textIn a Pinus halepensis Mill. forest, a field experiment was designed to evaluate post-fire seed predation as affected by combinations of seed
colour and soil substrates: light grey and black seeds combined with light grey ash, dark grey ash and pale brown sand. A survey of bird species
inhabiting the area was also carried out and polyphenolic content of seed coat was assessed in seed lots of different colour. Light grey seeds
were observed to be less predated on light grey ash, suggesting eucrypsis as a protective strategy against bird predation. On the contrary, no
clear pattern was observed for the predation of black seeds on different substrates. In the study area both bird species breaking the seed coat and
eating the endosperm and bird species swallowing the whole seed were monitored. We have estimated that more seeds were swallowed than
broken, in all colour categories. Light grey seeds, which were found to have a higher content of polyphenols, were predated more than black
seeds when exposed on the same substrate. Thus, no evidence was produced that the amount of polyphenols in seed coat could protect seeds
from predation
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
Pattern of resin dripping under Aleppo pines (Pinus halepensis Mill.) of different crown size
No full textSeveral studies have explored the role of conifer oleoresins in the defense against herbivores and fungal attacks. However, biotic and abiotic injuries on stem and crown also promote resin fall and its accumulation in the forest floor. No study has explored oleoresins accumulation in the litter and soil layers under the crown: the modification of soil properties after fire is unknown. To quantify the magnitude of resin fall in a Mediterranean uneven-aged forest of Aleppo pine (Pinus halepensis Mill.) the amount and pattern of resin dripping was monthly monitored under large, medium and small crowns. During summer (June-September) occurred 58% to 80% of resin fall. Resin amount decreased significantly from the stem towards the crown border; half of the resin was collected along the West direction, which is the dominant wind direction in the study area. The larger amount of resin collected near the stem of trees with large crown could explain the germination pattern found in burnt soil profile bioessays collected in the same position
Pattern of resin dripping under Aleppo pines (Pinus halepensis Mill.) of different crown size
No full textSeveral studies have explored the role of conifer oleoresins in the defense against herbivores and fungal attacks. However, biotic and abiotic injuries on stem and crown also promote resin fall and its accumulation in the forest floor. No study has explored oleoresins accumulation in the litter and soil layers under the crown: the modification of soil properties after fire is unknown. To quantify the magnitude of resin fall in a Mediterranean uneven-aged forest of Aleppo pine (Pinus halepensis Mill.) the amount and pattern of resin dripping was monthly monitored under large, medium and small crowns. During summer (June-September) occurred 58% to 80% of resin fall. Resin amount decreased significantly from the stem towards the crown border; half of the resin was collected along the West direction, which is the dominant wind direction in the study area. The larger amount of resin collected near the stem of trees with large crown could explain the germination pattern found in burnt soil profile bioessays collected in the same position
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
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