1,721,057 research outputs found

    Discordant twins as a tool to unravel the aetiology of bipolar disorder.

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    This editorial focuses on discordant twins as a valuable epidemiological design for psychiatric aetiological research. First, we summarise the advantages and strengths of this design over the classical matched case-control study. Then, we draw attention to the use of this method in bipolar disorder, revising previous discordant-twin studies. A future greater use of discordant twins is desirable to gain further relevant insights in the aetiology of bipolar disorder

    Emerging Effects of Early Environmental Factors over Genetic Background for Type 1 Diabetes Susceptibility: Evidence from a Nationwide Italian Twin Study

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    Context: The incidence of type 1 diabetes has been increasing over time. Objective: We estimated the genetic and environmental components of type 1 diabetes susceptibility in a twin cohort of recent-onset cases to explore the sources of changing disease epidemiology. Design: We linked the population-based Italian Twin Registry with 14803 type 1 diabetes records from 36 pediatric diabetes care centers throughout Italy, except Sardinia, and identified 173 diabetic twins. Patients were positive for at least one autoantibody to islet cell, glutamate decarboxylase, tyrosine phosphatase, insulin, or zinc transporter 8 and were insulin dependent since their diagnosis. Zygosity was determined by DNA genotyping or by questionnaire. Outcome Measures: We estimated proband-wise concordance, cotwin recurrence risk with Kaplan-Meier method, and genetic and environmental proportions of susceptibility variance by structural equation models. Results: We recruited 104 diabetic twins (53 males) from 88 pairs (34 monozygotic, 54 dizygotic) and one triplet. The mean age at diagnosis was 8.1 yr (range 1.1-20.5 yr), and the median year of diagnosis was 2002. Proband-wise concordances were 45.5 and 16.4% in monozygotic and dizygotic pairs (P = 0.01). Recurrence risks in monozygotic and dizygotic cotwins were 37 and 12% after 10 yr from the proband's diagnosis (P = 0.005). Genetic contribution to type 1 diabetes susceptibility was 40% (95% confidence interval 8-78), and the shared and individual-specific environmental components were 51% (14-77) and 9% (4 -19), respectively. Conclusions: In addition to the moderate genetic effects on type 1 diabetes susceptibility, our results draw attention to the substantial shared environmental effects, suggesting that exposures in fetal or early postnatal life may contribute to the increasing incidence of the disease. (J Clin Endocrinol Metab 97: E1483-E1491, 2012

    Genetic and environmental bases of the interplay between magical ideation and personality.

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    Sub-threshold psychotic symptoms are quite commonly present in general population. Among these, Magical Ideation (MI) has been proved to be a valid predictor of psychosis. However, the genetic and environmental influences on the interplay between MI and personality have not fully been explored. A total of 534 adult twins from the population-based Italian Twin Register were assessed for MI using the MI Scale (MIS) and for personality with the temperament and character inventory (TCI). A Multivariate Cholesky model was applied with Mx statistical program. The best-fitting model showed that additive genetic and unshared environmental factors explain approximately the same proportion of variance in MI, whereas a less strong genetic influence on personality traits emerged. Relevant correlations between MI and specific personality traits (novelty seeking, cooperativeness, self-directedness, self-transcendence) were found, suggesting shared influences for MI and these traits. Both genetic and environmental factors explained these correlations, with genetic factors playing a predominant role. Moderate-to-substantial genetic effects on MI and personality were found. Shared genetic and environmental effects underlie the phenotypic correlation between MI (psychosis-proneness) and personality traits, i.e. self-directedness (negative association) and self-transcendence (positive association), potentially representing predictive markers of psychosis liability related to schizotypy and personality

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    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

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    “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
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