1,720,995 research outputs found
Towards the establishment of the Italian network of old-growth forests: the understorey plant diversity perspective
Full text linkThe publication of the Decree that has established the Italian network of old-growth forests opens new opportunities for nature conservation and new challenges for scientists. A fundamental criterion for the identification of old-growth forests is related to a “characteristic biodiversity” due to the absence of disturbances for at least sixty years. In this contribution we mainly discuss shortcomings, potential interpretation and perspectives related to the application of this criterion for the vascular plants living in the understorey. We show that the understorey diversity (both taxonomic and functional) patterns with forest maturity are strongly context-dependent and stand structural features are fundamental drivers. As a consequence, considering the impressive heterogeneity of Italian forests, the strict threshold included in the Decree (sixty years since the last disturbance) can hardly be used to distinguish a “characteristic biodiversity”. Finally, we invite all the Italian scientists dealing with forest ecosystems to strongly collaborate in order to accept the challenge introduced by the Decree
Diversity of european habitat types is correlated with geography more than climate and human pressure
Full text linkBIOME (Biodiversity and Macroecology Group) Group was partially supported by the H2020 SHOWCASE (Grant agreement No 862480) and by the H2020 COST Action CA17134 ‘Optical synergies for spatiotemporal sensing of scalable ecophysiological traits (SENECO)’.Cervellini, M., Di Musciano, M., Zannini, P., Fattorini, S., Jiménez-Alfaro, B., Agrillo, E., Attorre, F., Angelini, P., Beierkuhnlein, C., Casella, L., Field, R., Fischer, J.-C., Genovesi, P., Hoffmann, S., Irl, S.D.H., Nascimbene, J., Rocchini, D., Steinbauer, M., Vetaas, O.R., Chiarucci, A
SOME EFFECTS OF TONAL FATIGUING ON SPONTANEOUS AND DISTORTION-PRODUCT OTOACOUSTIC EMISSIONS
No full textAuditory fatiguing can be considered a suitable test to assess some cochlear mechanisms and diseases otherwise not easily detectable. Since spontaneous otoacoustic emissions (SOAEs) originate from active sources within the cochlea they show sensitive and early vulnerability to noise, displaying informative time-courses after overstimulation in the short (0-6 s) and in the long term (1-10 min) depending on the frequency of the fatiguing stimulus. Distortion product otoacoustic emissions too, in subjects with SOAEs, show interesting modifications after pure-tone exposure, detectable either on distortion product audiograms or in the growth functions. The modifications take place within a period of 5-7 minutes and strongly depend on the frequency of the fatiguing stimulus and on the closeness between SOAE and distortion product place. The data suggest that not only the interaction place between f1 and f2 has to be considered from a biomechanical and clinical point of view, but also the specific distortion product place on the cochlear partition
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
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