1,720,957 research outputs found
La campana del palazzo pretorio
No full textDocumento dell'11 giugno 1387 concernente la cessione della campana di un castello dell'Appennino tosco-romagnolo alla Comunità di Figline Valdarn
Isotopic discrimination during litter decomposition and d13C and d15N soil profiles in a young artificial stand and in an old floodplain forest.
No full textIn the present study, rates of litter decomposition and microbial biomass nitrogen were monitored over an 8-month period in a young broadleaf plantation (18 y) and in an old floodplain forest. Moreover, δ13C and δ15N temporal variations within soil profiles were evaluated at both sites. Rates of litter decomposition were higher in spring and autumn than in summer, in both forests. At the end of the observation period the percentage of original litter remaining was not statistically different between the young and the old forest and accounted for 60–70% of the original amount. Microbial biomass nitrogen in the remaining litter and the percentage of litter mass lost during decomposition were positively correlated. The difference in litter quality affected the decomposition rate and also the changes in carbon isotopic composition during the decomposition process. In contrast, 15N isotopic signatures showed a similar trend in the litter of the two forests irrespective of the litter quality.
Although δ13Csoil and δ15Nsoil showed considerable temporal variation they increased with depth in the soils of both sites but their seasonal changes did not reflect those of the decomposing litter. Within the same soil horizon, both δ13C and δ15N showed similar seasonal trends in the soils of the two forests, suggesting the involvement of environmental factors acting at regional level, such as soil temperature and rainfall variations, in regulating seasonal δ13C and δ15N soil variations
Physiological and biochemical stress responses in grassland species are influenced by both early-season ozone exposure and interspecific competition
No full textThe effects of two-year early season ozone exposure on physiological and biochemical stress response were investigated in model plant communities.
Achillea millefolium and Veronica chamaedrys target plants were grown in monocultures and in mixed cultures with Poa pratensis
(phytometer) and exposed in open-top chambers over two years for five weeks to charcoal-filtered (CF) air plus 25 nl l1 O3 (control) and
non-filtered (NF) air plus 50 nl l1 O3.
Significant O3 effects were detected in different physiological and biochemical parameters, evidencing interspecific differences in metabolic
stress responses and a strong influence of the competition factor. O3 induced strong oxidative effects in Achillea irrespective to the different
growth modality. Veronica showed less O3-induced effects in monoculture than when grown in competition with the phytometer. Poa exhibited
a different behaviour against O3 depending on the species in competition, showing an overall higher sensitivity to O3 when in mixture with
Achillea
Role of xanthophyll cycle-mediated photoprotection in Arbutus unedo plants exposed to water stress during the Mediterranean summer.
No full text
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
- …
