1,721,043 research outputs found
Conservazione di un anfibio iconico : lo status di Pelobates fuscus in Italia e linee guida d’azione
No full textIl pelobate fosco, Pelobates fuscus, mostra
evidenti segni di declino, in particolare lungo i bordi occidentali del suo areale distributivo, inclusa l’Italia, dove viene normalmente riconosciuta una sottospecie endemica, P. f. insubricus.
In questo contributo richiamiamo l’attenzione sui problemi osservati nel corso di una serie di azioni di conservazione sviluppate in Italia settentrionale.
Ribadiamo a tal proposito la generale
mancanza di coordinamento fra le varie inziative che si sono succedute, nonché il mancato recepimento a livello nazionale e locale dell’action plan, redatto specificamente per fornire chiare linee guida all’azione di conservazione.
Inoltre, commentiamo la presunta rarità di tale anfibio, da porre probabilmente in relazione anche all’oggettiva difficoltà di osservazione in natura.
Gli sporadici ritrovamenti sembrano essere,
almeno in parte connessi con le metodiche di rilevamento utilizzate. Suggeriamo pertanto alcuni sistemi che potrebbero facilitare la sua localizzazione.
Un sistema prevede la sistemazione, attorno ai siti riproduttivi, di barriere con trappole a caduta, nonché l’uso di un idrofono per localizzare i riproduttori in canto da posizioni subacquee.
Riportiamo inoltre indicazioni sull’attività
di monitoraggio al SIC “Stagni di Poirino-Favari”
(Torino), nonché una serie di azioni da applicare
per garantire l’efficacia della conservazione della
specie
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
La rubrica “I Musei delle Meraviglie” come strumento di valorizzazione per i Musei italiani di Storia Naturale e per promuovere le collezioni zoologiche
Get PDFWhen can chromosomes drive speciation? The peculiar case of the Malagasy tomato frogs (genus Dyscophus)
No full textExcept for polyploidy, parthenogenesis and hybridogenesis, the role of chromosome rearrangements in
speciation is still highly debated. This paper highlights an unusual karyotype diversification and a putative
case of chromosomal speciation in the endemic Malagasy tomato frogs.
The tomato frogs include Dyscophus insularis as well as the sister species D. antongilii and D. guineti,
which are characterized by a disjunct distribution and a low genetic divergence, probably due to a recent
hybridization. Our results show that the three Dyscophus species present 2n = 26 biarmed chromosomes,
differing in chromatin pattern. Interestingly, both sexes of D. guineti show a heteromorphic chromosome
pair 11, with one element larger (11a) than the other (11b) due to the presence of a large terminal tract
on the short arm with an euchromatic band enclosed between two heterochromatic bands. This fixed
condition reminds that of some newts of the genus Triturus, but in Dyscophus it probably characterizes the
beginning of a cladogenetic process. We hypothesize that in D. guineti the raising of the heteromorphic
11th chromosome pair followed the hybridization with D. antongilii, originating a post-zygotic barrier
and representing a case of sympatric or parapatric chromosomal speciation. This speciation mechanism
may also have had important biogeographic consequences, shaping the current disjunct distribution of
D. antongilii and D. guineti, so far not sufficiently explaine
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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