1,721,120 research outputs found

    Fetal cardiac parameters for prediction of twin-to-twin transfusion syndrome

    No full text
    OBJECTIVES: To assess myocardial performance index measured by conventional Doppler (MPI) and by tissue Doppler imaging (MPI') at 18 weeks' gestation in monochorionic diamniotic twins for the prediction of twin-to-twin transfusion syndrome (TTTS). METHODS: This was a single-center observational study of 100 uncomplicated monochorionic diamniotic twin pregnancies attending the twin pregnancy clinic at the University Hospital Spedali Civili of Brescia from 2009 to 2012. MPI and MPI' were obtained from the left (LV) and right (RV) ventricles of each twin at around 18 weeks of gestation (range, 17 + 1 to 19 + 4 weeks) and fortnightly thereafter. Cases which later developed TTTS formed the study group, and the remaining controls were subdivided into those continuing as uncomplicated pregnancies and those which later developed selective intrauterine growth restriction (sIUGR). Data were analyzed by receiver-operating characteristics curve analysis and univariate and multivariable logistic regression. RESULTS: Of the 100 pregnancies, 88 were controls (84 uncomplicated and four developed sIUGR) and 12 developed TTTS. RV-MPI and LV-MPI, and LV-MPI' were significantly higher in future TTTS recipients than in controls, while RV-MPI' was significantly lower in donors. RV-MPI and LV-MPI and LV-MPI' were found to be predictive indicators in pregnancies that had not yet developed TTTS. Their negative predictive values were > 90%, and their specificities > 80%. The best performing index was LV-MPI', with a sensitivity of 91.7% and specificity of 88.6%. CONCLUSIONS: Before diagnosis of TTTS, the cardiac function (as assessed by MPI and MPI') of the future donor twin is not grossly abnormal, but that of the recipient is abnormal. We identified cardiac indices predictive of the subsequent development of TTTS, and suggest a possible role of these indices in planning the follow-up of monochorionic diamniotic twin pregnancies

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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
    corecore