1,720,996 research outputs found
Atti Del XIX Convegno Nazionale Di Agrometeorologia 2016 “Nuove avversità e nuovi servizi per gli agroecosistemi” Bologna, 14-16 giugno 2016.
No full textSessione 1: Supporti agrometeorologici e nuove avversità- Sessione 2: Strumenti per la mitigazione e l’adattamento ai cambiamenti climatici- WORKSHOP: “ IL TAVOLO DI LAVORO NAZIONALE PER IL COORDINAMENTO DELLE ATTIVITÀ AGROMETEOROLOGICHE. IL PROGETTO AGROMETEORE
Changes in the rainfall–streamflow regimes related to climate change in a small catchment in Northern Italy
No full textClimate change has become an important issue for scientific community, for its numerous impacts, especially on agriculture and environment. To shed light on this phenomenon, long data-sets of meteorological data as well as temperature and rainfall extreme events are needed, since they are important climate variability indicators. In a small semi-agricultural catchment of the Italian Apennines, drained by the Centonara Stream, weather data have been monitored for 30 years (1986–2015). Here, their trend was identified with Mann–Kendall test, and the temperature and precipitation extremes were characterized by means of specific indices. Data were analyzed at event, daily, seasonal, and annual bases. In addition, to understand implications of rainfall patterns on catchment hydrological response, a total of 388 rainfall–streamflow events (recorded during 1994–2009) were analyzed. Results showed a significant increase of temperature (minimum (Tn), mean (Tm), and maximum (Tx)), both at annual and seasonal base, except for Winter, with an annual mean increase of 0.08, 0.09, and 0.13 °C year−1 for Tn, Tm, and Tx, respectively. Annual rainfall data showed a positive trend for the number of wet days, but not in the quantity. In Winter, the rainfall amount and the number of wet days increased. The annual number of rainfall extreme events (P > 20.2 mm and D > 18.3 h) significantly increased, especially in spring and autumn. The rainfall–streamflow relationship suggested that the flow response of the Centonara Stream depends mainly on the rainfall amount. So, since the number of extreme events (P > 20.2 mm) is increasing in spring and autumn, an increase of events with high streamflow in these seasons may occur
Agro-phenological observation and modeling of cereals in Padana Plain in the period 2003-2012
Full text linkAgro-phenological observation is a fundamental activity to obtain a significant and useful description of the seasonal development of crops, which is driven by environmental variables, among which temperature plays a primary role. The aim of this paper is to study the relation between thermal resources and phenological development in the agrophenological station of Cadriano (Bologna) on winter wheat, barley, maize and sorghum. This was achieved a) analysing eleven years (2003-2012) of phenological observations, expressed using the BBCH scale, and b) developing a thermal model based on Normal Heat Hours for phenological development of the four crops in Cadriano. Once the thermal model was calibrated it was used to evaluate the variability of thermal resources on a long time series (1984- 2013) recorded in the same site. The statistical analysis on the observed phenological data shows high stability, apart from the first stages, until the tillering of the winter crops. The phenological model evidences a satisfactory performance, in particular for summer crops, and a good correlation between phenology and thermal resources accumulation. Finally, the long time series analysis evidences an increase in time of thermal resources availability
Land use and water quality: results of three years of research in the Bologna area (Italy)
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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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