1,720,986 research outputs found
Contribution to the vascular flora of Castelvecchio nature reserve (Central Tuscany, Italy)
No full textIl presente lavoro riporta la flora vascolare della Riserva Naturale Regionale Castelvecchio, situata nel Comune di San Gimignano (Siena). La Riserva, con substrato di natura prevalentemente calcarea, ha un’estensione di 6,28 km2. Si riporta l’elenco floristico delle piante vascolari. Vengono inoltre forniti dati sulle forme biologiche e corologiche. Nel nostro contributo risultano 454 specie e sottospecie, suddivise in 73 famiglie e 185 generi. Lo spettro biologico rivela una dominanza di emicriptofite seguite dalle terofite, mentre lo spettro corologico mostra una maggioranza di specie a distribuzione eurasiatica rispetto a quella mediterranea, in accordo con le condizioni macro- e micro-climatiche. Sono presenti entità rare e/o con distribuzione frammentaria in Toscana come Cleistogenes serotina subsp. serotina, Ononis natrix e Phagnalon sordidum e due specie della Lista Rossa Italiana (Galanthus nivalis e Ruscus aculeatus). È inoltre da segnalare la presenza di entità rilevanti dal punto di vista fitogeografico come Taxus baccata, nonché popolazioni eterotopiche di Fagus sylvatica subsp. sylvatica. Le entità endemiche sono 6 (Digitalis micrantha, Helleborus viridis subsp. bocconei, Hieracium pallidum subsp. lanudae, Melampyrum italicum, Polygala flavescens subsp. flavescens, Scabiosa uniseta), un numero relativamente basso rispetto ad altre aree calcaree della Toscana centro-meridionale. Questa Riserva non può quindi essere considerata un’isola biogeografica su calcare dal punto di vista botanico, come altre aree protette in Toscana meridionale. Tuttavia, il mosaico vegetazionale, unito alle particolari condizioni geologiche e microclimatiche, rendono comunque la Riserva Naturale di Castelvecchio un’area di notevole importanza per la conservazione della biodiversità floristica della Toscana centrale dove coesistono popolazioni relitte ed isolate di specie mesofile che sopravvivono grazie al microclima fresco e umido dei valloni, a stretto contatto con quelle xerofile di gariga calcarea. L’eterogeneità ambientale unita all’elevato grado di naturalità rende possibile la presenza di specie rare e/o fitogeograficamente rilevanti e solamente quattordici sono le specie esotiche, la maggior parte delle quali presenti in modo casuale.This study reports the outcomes of botanical surveys of vascular plants carried out in the Castelvecchio Nature Reserve, located in the Municipality of San Gimignano (Siena province). The Reserve has an extension of 6.28 km2 with a predominance of calcareous bedrock. The compiled floristic inventory of the Reserve includes 454 species and subspecies, divided into 73 families and 185 genera. Data on life forms and chorological types are provided. The life-form spectrum revealed a dominance of hemicryptophytes followed by terophytes, whereas the chorological spectrum showed a majority of species with Eurasiatic distribution as opposed to a Mediterranean one, in line with the local macro and microclimatic conditions. Rare species in central Tuscany – such as Cleistogenes serotina subsp. serotina, Ononis natrix and Phagnalon sordidum − and two species on the Italian Red List − Galanthus nivalis and Ruscus aculeatus − were recorded. Also of interest is the occurrence of phytogeographically relevant entities as Taxus baccata and populations of Fagus sylvatica subsp. sylvatica outside of its altitudinal belt. Compared to other areas of central and southern Tuscany, the Italian endemics − Digitalis micrantha, Helleborus viridis subsp. bocconei, Hieracium pallidum subsp. lanudae, Melampyrum italicum, Polygala flavescens subsp. flavescens, Scabiosa uniseta – were less numerous. The Reserve does not have a species pool typical of limestone as other protected areas of central or southern Tuscany. However, the mosaic of different communities, combined with geological and microclimatic factors, makes the Reserve highly relevant for the conservation of biodiversity in central Tuscany. Its peculiarity is the presence of isolated populations of mesophilous species that are confined to ravines with a cool microclimate and are in contact with xerophilous species of calcareous garrigues. Besides a valuable heterogeneity of environments in the Reserve it is worth nothing that there are only fourteen alien species, mainly with a casual status of invasivity
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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