1,720,969 research outputs found
Vegetation-environment relationships in the ultramafic area of Monte Ferrato, Italy
No full textRelationships between some environmental features and species composition and abundance of grassland and dwarf shrub vegetation were investigated on Monte Ferrato, one of the best known ultramafic (serpentine) sites of Italy. The main aim was to test the importance of the available fraction of soil metals in causing the typical infertility of ultramafic soils. The physical and chemical features of soil were determined for each plot in which species composition and cover were recorded. The plots were classified by cluster analysis and ANOVA was applied to compare the environmental Variables of groups of plots. Canonical Correspondence Analysis (CCA) was used to detect the principle factors related to the gradient of species composition within the plant communities. It was found that the grassland and dwarf vegetation of Monte Ferrato is not negatively influenced by soil content of nickel and other metals. Pine canopy cover, which provides additional nutrient input and protects against erosion, was found to be important for evolution of the garigues into grasslands. The evolution of grassland turf induced the retention of higher levels of exchangeable cations, including potentially toxic metals, in the evolved soil
Deposition chemistry. Intensive Monitoring of Forest in Toscana. Project “Studies on Forest Damage” / Paper no.4 of the MONITO Program. Regione Toscana
No full textRilevazioni dell'Inquinamento atmosferico da elementi in tracce nella Toscana Meridionale mediante il lichene Parmelia caperata (L.) Ach.
No full textLeaf morphology and macronutrients in broadleaved trees in central Italy
No full textAs part of an intensive monitoring programme (MON.I.TO, Intensive Monitoring of Forests in Tuscany), a 3-year survey was carried out, which included three tree species (beech, Fagus sylvatica L.; Turkey oak, Quercus cerris L.; holm-oak, Quercus ilex L.) located at six different sites. Leaves were sampled annually and analysed for nutrient concentrations (nitrogen, sulphur, phosphorus, magnesium, calcium, potassium and sodium) and morphological parameters (leaf area, dry weight, leaf mass per area, leaf thickness and leaf density). Results indicated considerable interannual variation of all the parameters. Differences between sampling sites indicated that, of all parameters measured, leaf mass per area could explain best the differences in field performance under conditions of stress. In fact, leaf mass per area was greater in the drier sites or when sea salt deposition occurred. Nevertheless, the variation of leaf mass per area over the 3 years did not reflect the differences in rainfall. Higher leaf mass per area was accompanied by lower concentrations of phosphorus and nitrogen, which could be a dilution effect due to an increase of structural carbon compounds in sclerophyllous leaves, as revealed by the total foliar content of these elements. Leaf mass per area as a measure of sclerophylly reached very high values among mesophile vegetation. Long-range transport of sea salt from coastal areas to mountain areas was mirrored in sodium concentrations of leaves
Affinity of deep eutectic solvents with aromatic molecules and aromatic nanostructures in chemical transformations
No full textDeep eutectic solvents (DESs) are an innovative class of green liquids that are finding fruitful applications as substitutes of polluting organic solvents. One of the topics in which they are finding fruitful results is represented by their use in chemical transformations, subject in which they can act as green sol-vents as well they can participate to the reaction path as cat-alysts or reagents. Because of their structural features, a network of H-bonds between a donor and an acceptor mole -cule, DESs revealed to be successfully used with aromatic molecules or moieties due to the participation of the aromatic rings in this network of weak forces. In this review, the most recent and relevant uses of DESs in chemical transformations involving aromatic benzo-fused and aromatic heterocycle systems, as well as their use in the suspension and functionalization of aromatic nanostructures, are discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Foliar syntoms and nutritional status. Intensive Monitoring of Forest in Toscana. Project “Studies on Forest Damage”.Paper no.4 of the MONITO Program. Regione Toscana
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
- …
