1,721,039 research outputs found
Preliminary data on the trophic interactions between Scyliorhinus canicula (Scyliorhinidae) and Raja clavata (Rajidae) in the Central-Western Mediterranean
No full textPreliminary data on the diet and trophic competition between Scyliorhinus canicula and Raja clavata, caught in the seas surrounding Sardinia (central-western Mediterranean),during trawl surveys carried out from 2005 to 2008 are given. The low values of Levin and Shannon-Weaver indexes showed that these two species are specialized predators. The ontogenetic analysis of the diet showed different predatory patterns
LA CITTA' DEGLI SCAMBI Tra ricerca e didattica
No full textvolume che raccoglie la ricerca svolta all'interno del Dipartimento di Architettura di Ferrara riguardante i nuovi spazi dello scambio commerciale all'interno del tessuto urbano consolidato
LA CITTA' DEGLI SCAMBI Tra ricerca e didattica
No full textvolume che raccoglie la ricerca svolta all'interno del Dipartimento di Architettura di Ferrara riguardante i nuovi spazi dello scambio commerciale all'interno del tessuto urbano consolidato
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
Impact of Phalacrocorax carbo sinensis (Aves, Phalacrocoracidae) on the fishery resources of a Sardinian lagoon
No full textThe negative impact of ichthyophagous birds on fish stocks are now matter of great concern. The aim of this study is to assess the wintering diet of the Great Cormorant (Phalacrocorax carbo sinensis) in the S. Antioco lagoon (south-western Sardinia). Through the morphological analysis of undigested hard body parts, such as otoliths, it was possible to trace to the preyed species, their size, biomass and, then, to the average daily consumption of cormorants
A multiple models investigation on age and growth of the speckled ray (Raja polystigma) from Sardinian seas
No full textAge and growth of the small Mediterranean endemic skate, Raja polystigma Regan 1923 were studied through the annuli counts in vertebral centra. During the period between 2012 and 2013 a total of 183 speckled rays (97 females, ranging from 115 to 590 mm in TL and 87 males with TL among 118 and 521 mm) were caught through experimental (MED.I.T.S.) and commercial trawl surveys. From each individual total length (TL in mm) total mass (TM in g) in addition to the gender and maturity stage were recorded, then vertebral centra were extracted from the thoracic cavit. Annuli counts were made by two readers through the observation of vertebral sections stained in Alizarin Red. Readings showed a good reproducibility (Percent of Agreement = 86.8, %Cv = 7.0, Index of Average Percent Error = 5.177). The oldest skate observed was a female estimated at age 11 (TL = 590 mm) while the oldest male was aged 8 (TL = 521 mm). Four different models were applied on length at age data: the common von Bertalanffy growth function, the Exponential, and finally the Gompertz and the Logistic functions. According to the Akaike’s Information Criterion values the Logistic model (L∞ = 691.49 mm ± 10.21; K = 0.26 ± 0.008; point of inflection = 4.03 y-1 ± 0.147), followed by Gompertz function, provided the best fitting curve, showing a higher growth rate and consequently a lower L∞ value than what obtained with the VBGF (L∞ = 784.49 mm ± 12.2; K = 0.11 ± 0.004; t0 = -1.718). This result was obtained also for females and males separately. Given the best fitting results achieved with the Gompertz and the Logistic functions, R. polystigma seems to grow relatively faster during the first few years as previously reported for other batoid species
Trophic interaction among Chondrichthyes in the Central-Western Mediterranean
No full textThe diets and trophic interactions among 27 species of demersal Chondrichthyans caught by trawl in the Sardinian waters from 2008 to 2010 were analyzed. Niche breadth, as well as intraspecific and interspecific niche overlap and trophic level for each species, were determined. All the species preyed more frequently on a small number of items. While no differences were found between sexes and along depth, a significant ontogenetic variation of the diet was observed. The competition was higher in the deepest strata
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
Trophic interactions among Chondrichthyans in the Central-Western Mediterranean
No full textThe diets and trophic interactions among 27 species of demersal Chondrichthyans caught by trawl in the Sardinian waters from 2008 to 2010 were analyzed. Niche breadth, as well as intraspecific and interspecific niche overlap and trophic level for each species, were determined. All the species preyed more frequently on a small number of items. While no differences were found between sexes and along depth, a significant ontogenetic variation of the diet was observed. The competition was higher in the deepest strata
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