1,721,442 research outputs found
Wood specific gravity of trees in Amazonian white-water forests in relation to flooding
No full textWood specific gravity (SG) was analysed from wood cores of 180 individuals belonging to 58 common upper canopy tree species of late successional white water (varzea) forests in the Mamiraua Sustainable Development Reserve, Central Amazon Basin. We tested for a SG gradient of trees along the flood gradient. Mean SG in the low varzea was 0.62 g cm(-3), in the high varzea 0.57 g cm(-3). SG tended to increase with height and duration of flooding. In the two species that occurred in both forest types (Hevea spruceana, Tabebuia barbata) SG was significantly lower in the high varzea trees. Therefore, height and duration of flooding seem to be important factors influencing growth and wood properties in varzea trees. In addition, SG variation depended on the core section and to a lesser extent on tree diameter and height. Compared to trees in Amazonian upland ecosystems, SG of the varzea trees was lower than SG in Central and Eastern Amazonian terra firme, but was within the same range reported for Western Amazonian terra firme
Wood specific gravity of trees in Amazonian white-water forests in relation to flooding
No full textWood specific gravity (SG) was analysed from wood cores of 180 individuals belonging to 58 common upper canopy tree species of late successional white water (varzea) forests in the Mamiraua Sustainable Development Reserve, Central Amazon Basin. We tested for a SG gradient of trees along the flood gradient. Mean SG in the low varzea was 0.62 g cm(-3), in the high varzea 0.57 g cm(-3). SG tended to increase with height and duration of flooding. In the two species that occurred in both forest types (Hevea spruceana, Tabebuia barbata) SG was significantly lower in the high varzea trees. Therefore, height and duration of flooding seem to be important factors influencing growth and wood properties in varzea trees. In addition, SG variation depended on the core section and to a lesser extent on tree diameter and height. Compared to trees in Amazonian upland ecosystems, SG of the varzea trees was lower than SG in Central and Eastern Amazonian terra firme, but was within the same range reported for Western Amazonian terra firme
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
„Entwässerungsgräben zuschütten und Deiche zurückverlegen“ – Der Leiter des KIT-Aueninstituts tritt für eine konsequente Renaturierung der Flusslandschaften ein - Campus-Report am 14.11.2023
No full textDie Entwässerung der Landschaft: für unsere Vorväter war sie gleichbedeutend mit Fortschritt. Moore mussten trockengelegt, Wiesen entwässert, Bäche und Flüsse begradigt werden. Heute zeigt sich mit den Folgen des Klimawandels, dass dieses zivilisatorische Projekt unerwünschte Nebenwirkungen hat. Sowohl die Hochwasserkatastrophe im Ahrtal als auch die sinkenden Grundwasserspiegel in Deutschland sind auch Folgen dieses Kampfes gegen das Wasser in unseren Landschaften. Für den Leiter des Rastatter Aueninstituts des Karlsruher Instituts für Technologie Florian Wittmann ist ein Umdenken überfällig: Renaturierung sowohl am Oberlauf der Flüsse als auch in den großen Flusslandschaften am Unterlauf ist seiner Ansicht nach die einzige Möglichkeit, die dramatischen Folgen der Klimaerwärmung zu mildern. Ein Stück weit müsste beispielsweise das Werk des Johann Gottfried Tulla rückgängig gemacht werden, der im 19. Jahrhundert den wilden Rhein zähmte und seine Sümpfe trockenlegte
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