1,720,957 research outputs found
Efficiency of DNA mini-barcoding to assess mislabeling in commercial fish products in italy: An overview of the last decade
Full text linkThe problem of fish traceability in processed products is still an important issue in food safety. Major attention is nowadays dedicated to consumer health and prevention of possible frauds regulated by national and international laws. For this reason, a technical approach is fun-damental in revealing mislabeling at different levels. In particular, the use of genetic markers has been standardized and DNA barcoding is considered the gold-standard strategy to examine and prevent species substitution. Considering the richness of available DNA databases, it is nowadays possible to rapidly reach a reliable taxonomy at the species level. Among different approaches, an innovative method based on DNA mini barcoding has recently been proposed at an international level. Starting from this evidence, we herein illustrate an investigation dealing with the evolution of this topic in Italy over the last decade. The molecular analysis of 71 commercial fish samples based on mini-COI sequencing with two different primer sets reached an amplification success rate of 87.3 and 97.2%. The investigation revealed four major frauds (5.8%) and four minor ones (5.8%). Results highlighted a decrease in incorrect labeling in Italy from 32% to 11.6% over the last decade, although a recurrent involvement of “endangered” species sensu IUCN was still observed
Euryhaline Aliens Invading Italian Inland Waters: The Case of the Atlantic blue crab Callinectes sapidus Rathbun, 1896
Full text linkAlien invasive species represent a major threat in Italian freshwaters. Despite national and
European regulations aimed at the control and prevention of new invasive species, the number of
allochthonous species is increasing and so is the rate of spread. One of the most widespread invasive
animals in coastal areas of the Mediterranean Sea is the blue crab Callinectes sapidus, a native of
the Western Atlantic from Nova Scotia to Argentina. The species is euryhaline, and besides coastal
waters, it is also commonly recorded in upper estuaries and lower reaches of rivers. Considering its
fast adaptability and invasiveness, the main purpose of this work is to assess whether its biological
plasticity and invasive capability may represent, in addition to marine and coastal habitats, also a
potential threat for inland waters. Samples were collected in seven sites distributed between Southern
and Central Italy. The new records are herein presented, starting from the original introduction
by ballast waters and the actual westward migration in inland waters of Latium and Tuscany.
In addition, the threat to biodiversity is also discussed, considering the blue crab aggressiveness
toward both vertebrates and invertebrates, which may limit the distribution of native freshwater fish
and macrofauna
Strengths and weaknesses of different italian fish indices under the water framework directive guidelines
Full text linkThe ISECI (or F index) has been the first fish index to be recommended by the Italian Ministry of the Environment to assess the rivers ecological status with regard to fish communities, in accordance with the Water Framework Directive 2000/60 EC. In addition to ISECI, other fish indices have been developed such as the Forneris Ichthyic Index (I.I.) and a revised version of ISECI, the so-called NISECI. The latter is nowadays the reference Italian index in the framework of the Water Framework Directive. In this work, we analyzed 30 sampling sites along 18 watercourses in Northern Italy and computed the results of fish monitoring to evaluate the strength of ISECI and NISECI, as well as to assess weak points limiting their application. We detected several issues that undermine the ISECI effectiveness. The weakest point regarded the mismatch between the expected reference fish community and the sampled ones, which decreased the overall algorithm efficiency in the evaluation process. On the other hand, the results confirm the improvements introduced by NISECI. Although with some advancement, all three proposed indices revealed their weaknesses in the overall assessment of the ecological status of the water course, as also highlighted by a pioneering comparison with three expert-based blind judgements
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
Molecular barcoding: a tool to guarantee correct seafood labelling and quality and preserve the conservation of endangered species
No full textThe recent increase in international fish trade leads to the need for improving the traceability of fishery products. In relation to this, consistent monitoring of the production chain focusing on technological developments, handling, processing and distribution via global networks is necessary. Molecular barcoding has therefore been suggested as the gold standard in seafood species traceability and labelling. This review describes the DNA barcoding methodology for preventing food fraud and adulteration in fish. In particular, attention has been focused on the application of molecular techniques to determine the identity and authenticity of fish products, to discriminate the presence of different species in processed seafood and to characterize raw materials undergoing food industry processes. In this regard, we herein present a large number of studies performed in different countries, showing the most reliable DNA barcodes for species identification based on both mitochondrial (COI, cytb, 16S rDNA and 12S rDNA) and nuclear genes. Results are discussed considering the advantages and disadvantages of the different techniques in relation to different scientific issues. Special regard has been dedicated to a dual approach referring to both the consumer's health and the conservation of threatened species, with a special focus on the feasibility of the different genetic and genomic approaches in relation to both scientific objectives and permissible costs to obtain reliable traceability
Conservation genetics of barbel species (Teleostei, Cyprinidae) facing hybridization and introgression along an elevational gradient in protected areas of northern Italy
No full textThe European endemic barbels represent important bioindicators of river quality and are nowadays threatened by changing environmental conditions and hybridization with the invasive alien Barbus barbus. It is therefore fundamental to investigate interactions among species and adaptability to climate changes in protected areas of Northern Apennines. An investigation was carried out considering 248 barbel samples that were analysed for Cytb mitochondrial DNA and 192 at 10 microsatellite loci, to delineate the distribution and population structure of the two native species as well as the impact of invasive B. barbus inside 15 sites of the Natura 2000 network. The complex distribution of the native barbel species was highlighted, together with a significant genetic structure emerging in different populations. Only one site revealed a "pure" population of B. caninus while the other ones showed a high level of hybridization between the different barbel species. For the B. plebejus two "genetically pure" populations were found in the hill-mountain sector, while the hybridization level resulted in increasing in the lowest altitudinal stretch of watercourses with a consistent contribution driven by B. barbus. We herein present the first evidence of B. barbus introgression along an altitudinal gradient, carried from the lowland water course to mountain stretches driven by B. plebejus migration. B. plebejus is the species that can act as vicariant organism able to transfer the B. barbus genome from the plain habitats into B. caninus genome of the higher altitude waterstreams, as a consequence of habitat shifts due to climate changes and anthropogenic acitivities
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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