1,720,969 research outputs found
Is the weight of plastic litter correlated with vegetal wrack? A case study from a Central Italian beach
No full textSpatial distribution of microplastics in volcanic lake water and sediments: Relationships with depth and sediment grain size
No full text: Microplastics (plastics <5 mm) are globally widespread pollutants of aquatic ecosystems. As microplastics contaminate both water and sediments, research on their spatial distribution in these different environmental matrices has increased. However, fresh waters are poorly studied and even less so are lentic ecosystems. To contribute filling this knowledge gap, this study analyses the distribution of microplastics in the water column and surface sediments of a volcanic lake, namely Lake Bracciano. Furthermore, it analyses in more detail the relationship between the concentration of microplastics in sediments, its grain size and the sampling depth (i.e. nearshore or deep). Water and sediment sampling was carried out in different sectors of the lake (northern, eastern, southern, western) using a plankton net and a van Veen grab sampler, respectively. Two sediment samples were collected at each station in order to analyse the abundance of microplastic and to perform grain size analysis. Results show a mean concentration of 2.4 items m-3 in water and 42 items kg-1 in sediments. The distribution of microplastics is uneven between the different sampling stations, with the northern sector being the most contaminated in both matrices. The chemical composition and shape of microplastics vary between water and sediment. In particular, polyethylene terephthalate and polyvinyl chloride are the most abundant polymers in water and sediments, respectively. Fibres are the main shape of microplastics in water while fragments are more abundant in sediments. In-depth analysis of sediment shows that sediments from deep stations are more contaminated than nearshore samples and have more fragment-shaped microplastics than fibre-shaped ones. Furthermore, there is a significant positive correlation between the concentration of microplastics and the abundance of silt, confirming data emerging from the scientific literature on marine and lotic ecosystems
Hydra vulgaris assay as environmental assessment tool for ecotoxicology in freshwaters: a review
No full text
The Bryozoan collection of the Museo Civico di Zoologia of Rome
No full textThe Museo Civico di Zoologia of Rome houses a collection of Bryozoa donated by Professor Carla
Chimenz Gusso. The collection includes 1403 specimens preserved dried or in ethanol, 90 slides and
487 specimens on stubs (in gold). The collection also includes the types of Retevirgula akdenizae Chimenz,
Nicoletti & Lippi Boncampi, 1997, and Plesiocleidochasma mediterraneum Chimenz Gusso & Soule, 2003. Most
of the collection material was sampled in the Mediterranean Sea, largely off the Italian coasts, between
the early 1970s and 2005. Besides species endemic to the Mediterranean Sea, the collection houses representatives
of some species of particular conservation interest because considered threatened. They are:
Reteporella aporosa (Waters, 1895), Reteporella feuerbornii (Hass, 1948), Reteporella grimaldii (Jullien, 1903) and
Myriapora truncata (Pallas, 1766)
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
Ingestion of prey intensifies microplastic load in Mediterranean commercial fish
No full textWe describe the ingestion of plastics by four edible fish species from the Western Mediterranean Sea (Fiumicino,
Italy): Micromesistius poutassou, Mullus barbatus, Sardina pilchardus, and Trachurus trachurus. Microparticles
smaller than 1 mm, particularly blue fibres made of cellophane, are the most found in terms of size, colour,
shape, and polymer. The highest level of contamination was found in Sardina pilchardus and in stomachs containing
prey across all species. We have gathered evidence from commercially relevant fishes, of which two can
be good bioindicators of microplastics (M. barbatus and T. trachurus), and one is poorly investigated (M. poutassou)
in order to contribute to the overall assessments of the MP-induced risks for the Mediterranean ecosystem
and human activity
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
- …
