1,721,088 research outputs found
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
Intramedullary astrocytoma with cartilage formation. Case report.
No full textAbstract
A case of intramedullary astrocytoma with cartilage formation is reported. The presence of bone or cartilage in a glioma is most unusual and has been described only in the brain, characteristically in ependymomas and astrocytomas of the midline. As far as we know, the present is the first intramedullary case. The histological and immunohistochemical findings are discussed in the light of the various hypotheses that attempt to explain the presence of cartilage within a glioma
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
La dipendenza da internet in adolescenza tra normalità e psicopatologia: uno studio italiano
No full textOggetto: la crescente importanza evolutiva e la pervasività della rete tra i nativi digitali rischiano di condurre gli adolescenti a una situazione di scacco che può assumere le caratteristiche dell’internet addiction, una controversa psicopatologia con molteplici fattori di rischio e comorbidità.
Il presente lavoro intende valutare la prevalenza del disturbo in un campione adolescenziale italiano, individuarne i fattori di rischio peculiari di questa fase evolutiva, valutare il funzionamento dei soggetti addicted e a rischio e saggiare la sensibilità degli attuali strumenti diagnostici.
Metodo: 1483 studenti italiani di istituti secondari di secondo grado, di età compresa tra i 14 e i 21 anni, (M=16; DS=1,5), in prevalenza maschi (63%) hanno risposto a domande socio-demografiche e sull’utilizzo di Internet, seguite dalla somministrazione dei seguenti strumenti: Internet Addiction Test (IAT; Young 1998), Test Multidimensionale dell’Autostima (TMA; Bracken 1992) e Youth Self Report (YSR; Achenbach 1991).
Risultati: la prevalenza del disturbo è in linea con la letteratura (1,2%), tuttavia la fascia di soggetti a rischio registra un notevole aumento (49%). Le analisi hanno rilevato interessanti correlazioni tra i punteggi IAT e le scale TMA e YSR (p<,001). Le ANCOVA hanno evidenziato la miglior capacità predittiva di bassa autostima, età, ore di connessione e alcune sottoscale YSR (soprattutto problemi di pensiero).
Conclusioni: il presente lavoro ha individuato una relazione tra abuso di Internet e alcune problematiche connaturate alla fase adolescenziale. Quanto agli strumenti diagnostici, si è riscontrata la capacità del questionario più diffuso per internet addiction di individuare soggetti particolarmente problematici, ma è emersa una criticità nella caratterizzazione dei soggetti a rischio.Objective: the increasing importance in human development and in everyday life could lead adolescents to a new discussed psychopathology, characterized by multiple risk factors and comorbidities: Internet Addiction Disorder (IAD). The aim of this work is to evaluate the prevalence of the disease in an Italian adolescent sample, to focus on risk factors in youth, to test psychological functioning in addicted and at-risk subjects and to try out the sensibility of current assessment tools.
Method: 1483 Italian high school students, aged 14 – 21 years (M=16; SD=1.5), mainly men (63%), were asked to answer socio-demographic and Internet-use questions and to fill out the following tests: Internet Addiction Test (IAT; Young, 1998), The Multidimensional test of self-esteem (TMA; Bracken 1992) and Youth Self Report (YSR; Achenbach 1991).
Results: the prevalence of the IAD is consistent with the literature (1.2%), but at-risk range is much wider than in other studies (49%). Correlation analysis highlighted associations between IAT scores and TMA and YSR scores (p<.001). ANCOVA analysis showed that low self-esteem, age, connection time and some YSR subscales (mostly thought problems) perform best in predicting IAT scores.
Conclusions: Internet abuse seems to be connected to different kind of psychological distress in adolescence. The current questionnaires are able to identify high psychopathological subjects but fail to discriminate among at-risk subjects
Voltage evolution and electrochemical behaviour of Soil microbial fuel cells operated in different quality soils
Full text linkThe desire for a net-zero carbon future is a key driver for innovation in renewable energy. Amongst several emerging solutions, soil microbial fuel cells (SMFCs) pose an interesting addition as a low-cost, carbon–neutral technology. A full understanding on the electro-generative processes in SMFCs has, however, yet to be achieved, hindering the technology's translation into practical applications. In this study, an in-depth investigation into the evolution of the output voltage generated by membrane-less, flat-plate SMFCs that accounts for the contribution of both the anode and cathode potential is provided for the first time, along with a study of the influence that organic matter content and porosity in soil has on voltage dynamics. Four stages in voltage evolution over time were observed, which depended on soil properties. The content of organic matter had the greatest effect, leading to an output voltage nearly-three times higher, when it increased from 10 % to 50 %. In this case, the anode potential reached a value of −450 mV, which prompted an exponential increase in the cathode potential and led to a power density of 68 mWm−2. The experimental findings were used to develop a novel computational model that, by predicting the electrochemical behaviour of the SMFC in different soils, becomes a powerful guide for operating strategies that can markedly enhance electricity generation. Consequently, this study sets the foundation for effective system optimisation and real applications
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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