1,721,001 research outputs found
Temperature and precipitation trends in Bologna (Italy) from 1952 to 1999
No full textAn analysis was made of a historical set of meteorological data collected at the University of Bologna agrometeorological station (Cadriano, Bologna, Italy, 40°55′ N, 11°4′ E, 33 m a.s.l.), between 1952 and 1999. Increasing trends of approximately 0.7 °C in 48 years in the mean annual temperature were found, all the anomalies of the last 12 years being above the average. A decrease in the long-term diurnal range was also observed, due to a higher increase in the minimum than in the maximum air temperature. The annual total rainfall decreased during the period in study showing a significant negative trend in winter. The number of rainy days decreased by about 20% and the annual average water-table level receded by 27 cm during the 25 years of available data. © 2002 Elsevier Science B.V. All rights reserved
Losses of atrazine, metolachlor, prosulfuron and triasulfuron in subsurface drain water. I. Field results
No full textThe objective of this experiment was to estimate field-scale losses of metolachlor, prosulfuron, triasulfuron, atrazine and two of its metabolites (deethylatrazine and deisopropylatrazine) in subsurface drain water of two experimental sites located in the Po Valley (Italy), from April 1996 to March 1999. Atrazine and metolachlor concentrations in drain water of the two experimental sites showed similar patterns. However, different concentrations were observed. In the Cadriano silty loam, concentration peaks of 20.6 and 18.2 μg·L-1, respectively, for atrazine and metolachlor, were observed. In the Carpi silty clay, higher concentrations were observed (atrazine: 127.0 μg·L-1, metolachlor: 180.0 μg·L-1). The results obtained suggest an involvement of preferential flow in the overall transport of the four herbicides in the soil. Estimated losses of atrazine, metolachlor, prosulfuron and triasulfuron in subsurface drain water were respectively 0.27, 0.61, 2.3 and 0.73% of the applied rate in Cadriano, and 2.14, 1.14, 10.6 and 0.07% of the applied rate in Carpi
Geostatistical analysis of soil arthropods in a farm scale context: the importance of ecological infrastructures for landscape management.
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Water, soil and chemical losses: Field experiments and model analysis
No full textThe study of the environmental impact of water erosion, chemicals and nutrient transport by runoff water is very important to protect soil and water quality. It is possible to find much literature on this topic, but the survey data lack uniformity and represent many different agronomic or natural environments. This is due to the wide range of parameters involved in these phenomena, such as soil and geomorphologic characteristics, tillage and crop management, nutrients and pesticides used. Results of some experiments are presented in this paper. A comparison of water, soil and chemical losses has been made between experimental data and modeling outputs, both at plot and at watershed scale. The findings indicate that monitoring and modeling are two complementary instruments, both necessary for the analysis of agrochemical transport phenomena, and that the proposed methodology is useful to evaluate the related environmental impact under different scenarios
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
Appropriate 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
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