1,721,777 research outputs found
Cluster headache as a disorder of inner temporal organization
No full textReview di dati personali e della letteratura sulle evidenze che fanno considerare la cefalea a grappolo come risultato dell'alterazione dei meccanismi centrali di controllo dei ritmi biologic
Migraine as a complex disease:heterogeneity, comorbidity and genotype-phenotype interactions.
No full textMigraine is a chronic illness interspersed with acute signs and symptoms which is currently defined, according to IHS criteria, in terms of "attacks". However, this should not lead us to ignore a critical point emerging from the simple observation of patients, i.e. the variability of the combinations in which the disease manifests itself in the same individual and especially in different individuals. This heterogeneity underpins both migraine "as attacks" (e.g. presence/absence of aura, different pain severity) and migraine "as a disease" (e.g. different onset, occurrence, association with other diseases, evolution, outcome). Genetic determinants are certainly at the basis of some migraine forms, and the role of genetics is now increasing due to the better phenotypical characterization rendered possible by the 1988 criteria. In most cases, however, migraine occurs as multifactorial inherited character. The level of complexity is further increased by the effect of "modifying" genes (such as those encoding for dopamine receptors), by comorbidity (the non coincidental association with other neurological diseases), and by the fact that the expression of comorbidity varies over time (phenotypical heterochronia). The clinical-descriptive approach allows only a partial understanding of migraine, the nature of which is more complex and heterogeneous than previously thought
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
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