1,721,048 research outputs found
Leucodistrofia metacromatica: un caso di pubertà precoce
No full textLeucodistrofia metacromatica: un caso di pubertà precoce
Nardecchia F 1
, Poratti E 1
, Dimiccoli P 1
, Di Maggio C 1
, Commone A 1
, Pucci C 1
, Leuzzi V 1
1DAI Neurosc e Sal Ment, Univ Sapienza, Roma
INTRODUZIONE/BACKGROUND: La leucodistrofia metacromatica è una malattia lisosomiale,
autosomica recessiva, caratterizzata
dall'accumulo di solfatidi a livello della mielina del sistema nervoso e, in minor quantità, nei tessuti
a funzione escretoria, tra cui reni, fegato e cistifellea. E’ stato descritto, inoltre, coinvolgimento di
tipo deficitario dell’ipofisi anteriore, surreni, testicoli, ovaie ed endometrio.
METODI / PAZIENTI:Il caso presentato è una bambina di 7,6 anni con esordio tipico intorno ai 2,6
anni, caratterizzato
da rapida regressione psicomotoria e ipotono. La RMN dell’encefalo mostarva diffusa e marcata
iperintensità di segnale della
sostanza bianca biemisferica sovratentoriale, con coinvolgimento del corpo calloso. Il dosaggio dell
dell’attività dell’arilsulfatasi A rivelava una riduzione del 91% e l’indagine genetica una eterozigosi
composta per [p.Tyr201Cys] e [p.Leu428Pro] nel gene ARSA. A 6 mesi dalla diagnosi comparsa di
episodi critici polimorfi. Intorno ai 4 anni osservato telarca
bilaterale isolato e incremento della lanuggine corporea, con successiva comparsa di pubarca.
RISULTATI:Il GnRH test evidenziava un’attivazione dell’asse ipotalamo-ipofisi- gonadi,
definendo un quadro di
pubertà precoce centrale. L’ecografia pelvica mostrava alcuni follicoli bilaterali con diametro di 3
mm. L’Rx polso evidenziava un’età ossea avanzata rispetto a quella cronologica, con uno scarto
superiore ad un anno. La progressione del quadro neurologico ha determinato un quadro di
tetraparesi spastico-distonica, assenza di linguaggio e residuo ed incostante contatto di sguardo.
Assume terapia antiepilettica con crisi plurisettimanali e trattamento ormonale con analoghi del
GnRH.
DISCUSSIONE:A differenza del riscontro di ipofunzionamento dell’asse ipotalamo-ipofisi- gonadi
descritto nelle
leucodistrofie e consensuale al processo degenerativo, si segnala in questo caso l’iperattivazione
dell’asse, finora non descritta in letteratura
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
Su alcuni aspetti eco-etologici riguardanti le femmine di Dacus oleae (Gmel.) catturate con cartelle “Prokoboll”.
No full textDefinizione della soglia economica per interventi contro gli stadi preimmaginali di Dacus oleae (Gmel.) in Umbria.
No full textVariations 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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