1,720,956 research outputs found
Prevalence of Diphyllobothrium latum (Cestoda: Diphyllobothriidae) plerocercoids in fish species from four Italian lakes and risk for the consumers
Full text linkIn recent years there has been a re-emergence of diphyllobothriasis by Diphyllobothrium latum (Cestoda: Diphyllobothriidae) in Italy, France and Switzerland, where in the past this fish-borne zoonosis was widespread and then virtually disappeared. A change in eating habits such as the consumption of raw/undercooked freshwater fish, has led to an increased risk for consumers of ingesting infective larvae of D. latum. A survey on the factors responsible for the re-emergence of human diphyllobothriasis in Italy was carried out from March 2013 to December 2014. The aim of this study was to assess the diffusion of D. latum plerocercoids in the fish populations of the sub-alpine lakes of Maggiore, Como, Iseo and Garda, updating the scarce historical data and assessing a preliminary “risk level” of the lacustrine environments and fish species under investigation. A total of 2228 fish belonging to 5 species, 690 from Lake Maggiore, 500 from Lake Como, 655 from Lake Iseo and 383 from Lake Garda were submitted to parasitological examination. The presence of D. latum plerocercoid larvae was detected in 6.6%, 25.4% and 7.6% of perch (Perca fluviatilis) from Lakes Maggiore, Como and Iseo respectively. The parasite was also present in pike (Esox lucius) with prevalence values ranging from 71.4 to 84.2% and in 3.6–3.8% of burbot (Lota lota) from Lakes Iseo and Como. Fish from Lake Garda were negative as well as sampled whitefish (Coregonus lavaretus) and shad (Alosa fallax lacustris). The results of this survey showed a widespread presence of D. latum plerocercoid larvae in Maggiore, Como and Iseo fish populations. Urban fecal contamination of water is still a key issue to be resolved, together with the improvement of communication with consumers regarding the best dietary habits and the most effective processes of parasite inactivation, required for the consumption of raw/undercooked fish caught in high-risk areas
Il siluro e la contaminazione ambientale: utilizzo di una specie invasiva per il monitoraggio delle sostanze inquinanti in ambiente acquatico
No full textIt is well established that fish are directly or indirectly affected by compounds that are toxic or
lethal in certain concentrations. Recently the enhancement of the legislative decree n. 172/2015
“Attuazione della direttiva 2013/39/UE, che modifica le direttive 2000/60/CE per quanto riguarda le
sostanze prioritarie nel settore della politica delle acque” require the analysis of chemicals
compound in biota, particularly in fish and in mollusks/shellfish.
The European catfish (Silurus glanis) even thought is an alien species in Italian freshwater, it can be
considered a valid bioindicators since it is at the top of food chain, and then can well reflect the
contamination of freshwater. In Italy, this species has received an increasing interest in recreational
fishing and also for human consumption, with possible risks linked to food safety. Factors as age,
sex, size, sexual maturity and breeding season may influence the concentration of contaminants.
During the presentation will be set out the results of the research conducted by IZS PLV about this
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topic, providing ideas and suggestions taking into account the guidelines issued by ISPRA
regarding the analysis of the priority substances on biota
Caratterizzazione morfologica e genetica di una popolazione di misgurno (Misgurnus anguillicaudatus Cantor, 1842) in Provincia di Vercelli
No full textIn Italia, così come nel resto del Mondo, sono presenti specie estranee alla fauna originaria, intenzionalmente o accidentalmente immesse dall'uomo in epoca storica. All'interno del territorio italiano sono indigene 50 specie ittiche d'acqua dolce, di cui 22 endemiche o sub-endemiche. A tutt'oggi risultano inoltre presenti 51 specie aliene, per la gran parte immesse nella seconda metà del Novecento. Considerando la frequenza con cui viene introdotto materiale proveniente dall'estero, la conseguente comparsa di specie aliene nelle nostre acque dolci è sempre in aumento. L’introduzione di specie ittiche aliene è un grave problema anche per le acque piemontesi dove, su un totale di 45 specie, risultano 20 esotiche, ma si teme un ulteriore peggioramento. Misgurnus anguillicaudatus, noto con il nome comune di cobite di stagno orientale, è una specie di origine asiatica. La sua diffusione in Europa è dovuta al probabile rilascio di esemplari da acquariofilia divenuti troppo grandi per rimanere in cattività. In Piemonte la prima segnalazione è sull’Arbogna a Borgo Lavezzaro (NO). Oltre all’ovvia competizione con le altre specie di Cobitidi presenti in Italia, tra cui il raro ed endemico cobite padano (Sabanejewia larvata), questa specie, grazie anche alla riproduzione efficiente e ripetuta più volte nel corso dell’anno ed all’ampia valenza ecologica, tollerando temperature oscillanti tra 2 e i 30°C, stabilisce popolazioni numerosissime e talvolta dominanti negli ambienti in cui si insedia (corsi d'acqua di portata esigua, stagni, canali e risaie). Nei corsi d'acqua piemontesi, nel corso dei campionamenti mirati alla definizione della carta ittica, la sua frequenza di ritrovamento, rispetto al totale delle stazioni campionate (428), è passata dallo 0% nel 1989 all'1,6% nel 2009. Nel corso dell'estate 2015, 40 esemplari ascrivibili a M. angullicaudatus provenienti da un canale di scolo di una risaia di Motta dei Conti (VC) sono stati sottoposti ad analisi morfologica e genetica. Morfologicamente sono stati individuati tre tipi differenti di pattern fenotipici. Ventuno individui, selezionati all'interno dei tre pattern, sono stati sottoposti ad identificazione genetica di specie. Dall’analisi è stato possibile evidenziare l’assenza di corrispondenza tra caratteristiche morfologiche e genetiche poiché ad certo profilo genetico non corrisponde un morfotipo. La maggior parte dei campioni sono stati identificati come M. anguillicaudatus, mentre per gli altri non è stato possibile stabilire la specie, ma sono stati classificati come Misgurnus spp. Inoltre, all’interno di questo gruppo, è stato possibile evidenziare la presenza di due sottogruppi separati, sempre indipendentemente dal morfotipo di appartenenza. L’analisi genetica è stata condotta impiegando un marcatore mitocondriale (COI) quindi non si può escludere che si tratti di ibridi; per questo motivo, ulteriori studi che prevedono l’uso di marcatori nucleari saranno condotti
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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