1,720,967 research outputs found

    Petrous internal carotid artery aneurysm: A cause of chronic otitis

    Full text link
    Background: Aneurysm of the petrous segment of the internal carotid artery (pICA) is a rare pathology presenting with extracranial and especially oto-rhinological symptoms that can be misleading and delay diagnosis. Methods: We report the case of a giant pICA aneurysm compressing the Eustachian tube (ET), presenting with hearing loss due to chronic serous otitis. A PRISMA review of the literature was performed to find similar cases. In addition, relevant anatomical sources were screened. Results: Five reports about 7 cases of middle-ear effusion caused by pICA aneurysm compressing the ET were identified. Median age at diagnosis was 18.5 years. After endovascular treatment, overall outcome was favorable, with no mortality, although outcome was sometimes impaired by neurological comorbidities and unclear prognosis of hearing-loss recovery. Discussion: These reports, though rare, offer relevant insights into the poorly known regional anatomy of the pICA, in the borderland between neurosurgery and ENT. Within the petrous bone, the osseous separation between the ET and the pICA is narrow, when not dehiscent. This leads to a risk of any pathological process in either the pICA or the ET impinging on the other. Conclusion: Giant pICA aneurysm is a rare cause of hearing loss, due to compression of the ET, leading to chronic serous otitis. This co-dependency between pICA and ET should be kept in mind, as it underlines the necessity of multidisciplinary management and could facilitate earlier diagnosis and therapeutic management when facing atypical clinical situations

    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

    Appropriate Similarity Measures for Author Cocitation Analysis

    Full text link
    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

    Full text link
    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

    No full text
    Nao informado

    Delayed cerebral ischemia after meningioma resection: Literature review and illustrative case

    No full text
    Background: Cerebral vasospasm results from arterial vasoconstriction, mainly following aneurysmal subarachnoid hemorrhage, and may cause delayed cerebral ischemia (DCI). DCI rarely occurs after tumor resection. We performed a systematic review of the literature together with a case report of DCI after meningioma resection. Literature review: methods: A systematic literature review was performed following the PRISMA statement, searching the PubMed, Medline and Cochrane databases using keywords and MESH terms related to “vasospasm/DCI and meningioma resection”. Results: In the studies retrieved in the literature, 5 cases of DCI after meningioma surgery were identified. The average age of patients was 52 years. The average onset time of DCI was 9.7 days. Clinical presentation was highly variable: hemiparesis (60%), confusion (60%) and/or aphasia (40%). Meningioma location was most frequently sphenoidal (60%). Most patients had vasospasm in multiple cerebral vessels, involving only the anterior circulation. Various management strategies were used: endovascular treatment (33.3%), antiplatelet therapy (50%) and/or nimodipine (40%). In terms of outcome, there were no deaths, but most patients had variable neurological sequelae (80%): aphasia, visual impairment, hemiparesis. Conclusion: The systematic literature review and the present case of DCI following resection of an olfactory meningioma suggested that the main etiologic factors causing this rare pathology are: 1) intraoperative subarachnoid hemorrhagic contamination; 2) microvascular manipulation; 3) and possible dysregulation of hypothalamic function

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    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
    corecore