1,721,039 research outputs found
Studio qualitativo e quantitativo del fitoplancton e analisi delle clorofille
No full textIn: Il Lago di Ledro, valutazione del suo stato trofico - a cura di Casellato S
Life history traits of the American spiny-cheek crayfish in two subalpine lakes
Full text linkThe ecology of Faxonius limosus in non-native habitats is poorly understood
and needs to be broadened to prevent and control its spread and protect native riverine decapod
populations. The aim of this study was to describe some autecological traits of a spiny-cheek
crayfish population established in two subalpine Italian lakes. We sampled the littoral zones in
May and October 2014 by using hand-nets and baited traps: captured individuals were then
sexed, weighed and measured. A population analysis was also performed using the modal progression analysis of length compositions. Our findings underlined the existence of four age
classes (with a life expectancy of 3.5/4 years), a lower growth rate compared to other crayfish of
the same family, and shift of the reproductive period respect to other studies on F. limosus. Our
results suggested that eradication activities ought to be developed based on the situationality,
and mitigating projects should be integrated with a continuous and practical monitoring programme to assess eventual changes in the ecological requirements of the investigated species.
This becomes increasingly important as reintroduction or restocking of indigenous species could
also be considered as a management strategy for F. limosus populations in the study area
Anti-GAD epileptic encephalopathy in a toddler with Parry-Romberg syndrome
No full textParry-Romberg syndrome (PRS) is a progressive facial hemiatrophy often associated with severe epilepsy. Although an immune-mediated vasculitic pathogenesis is widely assumed, no CNS-specific autoantibody has been described so far. A 2-year-old boy was admitted for a status epilepticus preceded by fever, restlessness, insomnia, and left facial rash. Cerebrospinal fluid was positive for glutamic acid decarboxylase (GAD)-antibodies. Brain MRI revealed FLAIR hyperintensities on left mediotemporal areas. He was successfully treated with intravenous methylprednisolone. One month later, seizures and facial rash reappeared and steroids were satisfactorily repeated. However, left hemifacial rash reappeared 5 months later, slowly followed by sclerotic skin lesions on frontal scalp and hemifacial sub-atrophy, leading to a diagnosis of PRS. Three years later, and despite chronic immunosuppression, new MRI lesions on left white matter are seen and left hemifacial atrophy has progressed. For the first time, we describe GAD autoantibodies in a PRS patient with epileptic encephalopathy. Epileptic syndromes with GAD autoantibodies are frequently described though with a questionable pathogenic significance. Given the clinical and MRI similarities of PRS with both Morphea and Rasmussen’s encephalitis, we suggest that, in our patient, the initial facial skin vasculitis spread into CNS vessels through perforating arteries, inducing neuronal MHC-class I presentation of GAD epitopes, ultimately causing CD8-mediated neuronal cytotoxicity and the epileptic encephalopathy. GAD autoantibodies might represent the missing pathophysiological link between PRS and neuropsychiatric manifestations
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
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