1,721,073 research outputs found
Environmental impact of radioactive releases due to Trino Vercellese Nuclear Power Plant decommissioning
No full textAs a consequence of the decision to cease operating the Italian Nuclear Power Plant (NPP) at Trino Vercellese, the environmental impact of its decommissioning has been evaluated. The radioactive releases from the NPP are very small and it is indeed very difficult to determine the critical group. The effective doses to representative members of the critical group are extremely low and well below the reference levels defined by the Italian Agency for Environmental Protection
Marine Invertebrates as Bioindicators of Heavy Metal Pollution
Full text linkAtmosphere, earth and water compose the environment. The presence of heavy metals in the environment
has grown because of their large employment in some industrial and agricultural activities.
Although these metals are terrestrial products, they flow into the sea through effluents and
sewage or are directly discharged from industries placed on the seawater front. It should be considered
that metals concentrations vary widely according to different seawater latitudes and
depths and can be strongly influenced by fresh water discharges from heavily polluted rivers. In
this review recent studies on heavy metal pollution in marine ecosystems and their organisms will
be presented. Metal speciation, bioaccumulation in biota, as well as abiotic and biotic factors affecting
their bioavailability will be reviewed. Moreover, the use of bioindicator organisms for the
biomonitoring of heavy metal toxicity and their ecological effects will be defined. Many marine
invertebrate species fulfill the following criteria: Sensitivity to a wide range of chemicals (especially
to heavy metals), cost-effectiveness for repeatable tests, readily interpretable biological consequences
of pollution. Among the most important marine invertebrates used as bioindicators, the
sea urchin embryo is one of the most suitable, especially to assess metal/heavy metal pollution
DETERMINATION OF THE MOLECULAR-ORIENTATION AT THE FREE-SURFACE OF LIQUID-CRYSTALS FROM BREWSTER-ANGLE MEASUREMENTS
No full textCadmium stress effects indicating marine pollution in different species of sea urchin employed as environmental bioindicators
No full textIn recent years, researches about the defense strategies induced by cadmium stress have greatly increased, invading several fields of scientific research. Mechanisms of cadmium-induced toxicity continue to be of interest for researchers given its ubiquitous nature and environmental distribution, where it often plays the role of pollutant for numerous organisms. The presence in the environment of this heavy metal has been constantly increasing because of its large employment in several industrial and agricultural activities. Cadmium does not have any biological role and, since it cannot be degraded by living organisms, it is irreversibly accumulated into cells, interacting with cellular components and molecular targets. Cadmium is one of the most studied heavy metal inductors of stress and a potent modulator of several processes such as apoptosis, autophagy, reactive oxygen species, protein kinase and phosphatase, mitochondrial function, metallothioneins, and heat-shock proteins. Sea urchins (adults, gametes, embryos, and larvae) offer an optimal opportunity to investigate the possible adaptive response of cells exposed to cadmium, since these cells are known to accumulate contaminants. In this review, we will examine several responses to stress induced by cadmium in different sea urchin species, with a focus on Paracentrotus lividus embryos. The sea urchin embryo represents a suitable system, as it is not subjected to legislation on animal welfare and can be easily used for toxicological studies and as a bioindicator of environmental pollution. Recently, it has been included into the guidelines for the use and interpretation of assays to monitor autophagy
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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