1,720,995 research outputs found

    A leftward bias negatively correlated with performance is selectively displayed by domestic chicks during rule reversal (not acquisition)

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    In order to face a constantly changing environment, animals need to be able to update their knowledge of the world on the basis of new information. Often, this means to inhibit a previously acquired response and flexibly change their behaviour to produce a new response. Here, we measured such abilities in young domestic chicks, employing a Colour Reversal Learning Task. During the acquisition phase, 17 one-week-old male chicks had to learn to peck on one of two coloured boxes to obtain a food reward. After reaching criterion, chicks underwent a reversal phase in which the previously learned colour-reward contingency was swapped. As expected from the literature, chicks performed better in the acquisition phase with respect to the reversal phase. Results moreover highlighted the presence of a lateralized bias selectively during reversal: chicks performed better if the stimulus rewarded was located in the left hemispace (processed by the right hemisphere). Interestingly, the bias correlated with the individual difficulty, i.e., it was stronger in those chicks which needed more trials to complete the reversal session. The present study contributes evidence in support of behavioural flexibility in young chicks, along with a novel perspective on lateralized mechanisms that might underlie such ability

    Retrospective descriptive analysis of 1,176 patients with failed hypospadias repair.

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    Abstract PURPOSE: To our knowledge epidemiological data on the incidence of failed hypospadias repair and the number of patients seeking further surgical treatment remain unknown. We report an observational, descriptive survey of patients who were evaluated and treated for urethral stricture disease and/or penile defects after primary hypospadias repair. MATERIALS AND METHODS: We performed a retrospective observational chart analysis of patients evaluated and treated for urethral stricture disease and/or penile defects at 2 tertiary European centers from January 1998 to December 2007. In each case we investigated the primary abnormal meatal site, the number of operations needed to repair primary hypospadias and complications of this primary repair. Patients were offered surgical repair for previous failed hypospadias treatment. After surgery evaluation was scheduled at 3, 6 and 9 months. Success was defined as a functional urethra without fistula, stricture or residual chordee and a cosmetically acceptable glanular meatus after the completion of all secondary procedures. RESULTS: A total of 1,176 patients with a mean age of 31 years were evaluated and treated. To treat failed hypospadias repair 760 (64.6%) and 416 patients (35.4%) underwent 1-stage and staged repair, respectively. Mean followup was 60.4 months. Of 1,176 cases 1,036 (88.1%) were classified as successful and 140 (11.9%) were considered failures. CONCLUSIONS: Failed hypospadias repair may be corrected by multiple and complex surgeries. Its effects are experienced during the lifetime of the patient and parents. PMID: 19913825 [PubMed - indexed for MEDLINE

    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

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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