1,721,044 research outputs found
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
Studies on Italian reservoirs
Full text linkThe main morphometric and water quality characteristics of the 221 Italian reservoirs covering an area of at least 0.2 km2 is given. Most of the reservoirs are used for drinking water purposes, especially on the islands of Sicily and Sardinia, where the more important cases of eutrophication have been found. These situations are examined in greater detail, with regard to algal population dynamics, the phosphorus budget and the comparison between theoretical and experimental nutrients loads. -from Author
Benthic diatoms as indicators of biological quality and physical disturbance in Mediterranean watercourses: a case study of the Rio Mannu di Porto Torres basin, northwestern Sardinia, Italy
No full textThis study focused on expanding existing knowledge about benthic diatoms and their use as indicators of biological quality and physical
disturbance in six Mediterranean watercourses within the Rio Mannu di Porto Torres basin in northwestern Sardinia, Italy. Benthic diatoms
were collected from 11 stations during a 1-year cycle from summer 2010 to summer 2011. The Eutrophication/Pollution Index – Diatombased
(EPI-D) was used to evaluate biological quality, and the Navicula Nitzschia Surirella Index (NNS’) was used to estimate the degree
of physical disturbance at each station. In addition, physico-chemical variables and Escherichia coli were measured and analyzed each
month. In total, 193 diatom taxa were identified, of which 157 belonging to 57 genera were present in the counts and were used to calculate
the diatom indices. Five taxa were recorded for the first time for Sardinian watercourses; of which, Amphora paraveneta Lange-Bertalot,
Cavacini, Tagliaventi&Alfinito, Fallacia pygmaea ssp. subpygmaea Lange-Bertalot, Cavacini, Tagliaventi&Alfinito and Diploneis spec.
(aff.?) modica Hustedt are biogeographically relevant, while Navicula kotschyi Grunow and Reimeria uniseriata Sala, Guerrero & Ferrario
are of particular interest as exotic species with relatively restricted distribution. The EPI-D revealed mediocre and bad water quality for
all the investigated stations, in agreement with the environmental variables and the heavy anthropogenic use of the study area. The EPI-D
was effective at inferring the biological quality of the studied watercourses, although some of the species that were found (7% of the total)
are not included in the method. We suggest including these species in the list to improve the performance of the index in Mediterranean
rivers. A comparison between the results obtained by the EPI-D and seven other European diatom indices was made. Significant statistical
correlations between the EPI-D and four of these indices were observed. The NNS’ was applied for the first time to Sardinian watercourses
and it indicated a significant degree of physical disturbance at nearly all the stations, due to seasonal fluctuations in water flow, which are
typical of the Mediterranean climate, combined with the effects of human activities
Note metodologiche per la definizione degli ambiti di paesaggio rurale nella pianificazione paesaggistica regionale sarda
No full textPhytoplankton dynamics in relation to environmental changes in a phytoplankton-dominated lagoon (Cabras Lagoon, Italy)
No full textVariations 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
What is Chrysophaeum taylorii Lewis & Bryan doing in Sardinia (Tyrrhenian Sea, Mediterranean)?
No full textCaulerpa racemosa var. cylindracea as a potential source of organic matter for benthic consumers: Evidences from a stable isotope analysis
No full textCaulerpa racemosa var. cylindracea has been invading various types of substrates in wide areas throughout the Mediterranean Sea. However, the effects of the distribution of this alga on zoobenthos are scanty. The aim of this study was to evaluate the effects of C. racemosa invasion on the feeding habits of some zoobenthic taxa inhabiting the upper infralittoral rocky shores. This was done by identifying the isotopic N and C ratios of several potential food sources and testing differences in isotope composition among the taxa collected from areas invaded and not-invaded areas by C. racemosa. Results suggest that C. racemosa detritus was a significant food source for the polychaete Syllis prolifera, the gammarid Corophium sextonae and the gastropods Cerithium rupestre and Pisinna glabrata. They would also suggest that stable carbon and nitrogen isotope ratios deserve further attention as a possible valuable approach to understand the overall effect of C. racemosa spread on the trophic interactions among the species. © Springer Science+Business Media B.V. 2008
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