1,721,461 research outputs found
Response to Dr Boyko’s letter: ‘Radiologically isolated syndrome with oligoclonal bands in CSF (RIS + OCB) can be classified as highly MS-risk group’
No full textCognition in multiple sclerosis: relevance of lesions, brain atrophy and proton MR spectroscopy
No full textThe overall burden of brain MRI-visible lesions does not fully account for cognitive impairment in multiple sclerosis (MS). Several MRI studies have highlighted the importance of brain damage in the normal-appearing brain tissue. Brain atrophy (global, cortical, white and deep grey matter) is related to cognitive deficits in MS patients and this holds true since the earliest disease stages. Non-conventional MRI techniques such as proton MR spectroscopy have related metabolic changes in specific brain areas to specific cognitive deficits. Overall, data provided by MRI support the notion that cognitive disturbances need to be considered for a more complete clinical characterisation of patients with MS, including those with "benign" MS
Proton MR Spectroscopy in Brain Metabolic Disorders
No full textMetabolic disorders of the central nervous system (CNS) include pathologies with extremely different pathogenesis. The clinical diagnosis of these disorders is often very difficult and requires sophisticated laboratory investigations. Proton magnetic resonance (MR) spectroscopy (1H-MRS) has recently been used in a number of clinical studies to supplement conventional MRI as it is able to provide in vivo biochemical assay of a given brain tissue. Brain data on several neurometabolic diseases suggest that 1H-MRS can provide in vivo chemical-pathologic characterization of the abnormality visualized by magnetic resonance imaging (MRI) and can detect metabolic alterations in tissue appearing normal on conventional MRI. This may help for differential diagnosis and can be important in the evaluation of disease outcome. Indices provided by 1H-MRS have been demonstrated to be relevant to patients' clinical status, to represent sensitive indicators of early neurologic involvement and to be helpful in monitoring effects of therapeutic interventions. This suggests that, in the next future, a more extensive use of brain 1H-MRS in the management of patients with metabolic disorders affecting CNS should be encouraged
Leukoencephalopathies and metabolic diseases
No full textLeukoencephalopathies and metabolic diseases comprise a great number of heterogeneous disorders. Diagnosis of these disorders may be challenging at times, requiring sophisticated laboratory investigations. Magnetic resonance imaging (MRI) is useful in supporting diagnosis even though it bears problems of specificity. Quantitative MRI techniques, providing information on cerebral metabolites and tissue microstructure within and outside visible lesions, have proven to be important for understanding the pathogenic mechanisms leading to tissue damage and monitoring disease evolution and response to treatment. This has prompted a more extensive use of these techniques in the clinical setting as a complement to the traditional MRI
New perspectives in clinical neurology: the promise of non-conventional magnetic resonance techniques
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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
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 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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