1,721,057 research outputs found
Pathophysiology of rigidity in Parkinson's disease: Another step forward
No full textnot applicable (editorial
Neurodegeneration and sensorimotor function
Full text linkSensorimotor integration is an essential function for both motor control and learning. Over recent decades, a growing body of evidence has emerged in support of the role of altered sensorimotor integration in the pathophysiology of various neurological conditions and movement disorders, particularly bradykinesia, tremor, and dystonia. However, the various causes and mechanisms underlying altered sensorimotor integration in movement disorders are still not entirely understood. The lack of complete insight into the pathophysiological role of altered sensorimotor integration in movement disorders is certainly due to the heterogeneity of movement disorders as well as to the variable occurrence of neurodegenerative phenomena, even in idiopathic movement disorders, which contribute to pathophysiology in a complex and often not easily interpretable way. Clarifying the possible relationship between neurodegenerative phenomena and sensorimotor deficits in movement disorders and other neurological conditions may guide the development of a more detailed disease prognosis and lead, perhaps, to the implementation of novel and individualized therapeutic interventions
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
Differential effects of motor skill acquisition on the primary motor and sensory cortices in healthy humans
No full textKey points: We explored the large variability in motor skill acquisition-related effects on the primary and sensory cortices. Namely, we tested whether this variability depends on interindividual variance or the type of motor task investigated. We compared different motor-learning tasks, i.e. model-free vs. model-based learning tasks, and their possible differential effects on the primary motor and sensory cortices by using transcranial magnetic stimulation techniques. The model-free learning task induced an increase in corticospinal excitability and a reduction in the amplitude of somatosensory-evoked potentials. Conversely, the model-based learning tasks induced a decrease in intracortical inhibition. No correlations were found between neurophysiological changes and motor performance, indicating that this differential modulation may be secondary to the motor skill acquisition. The study results suggest differential motor skill acquisition-related effects on cortical parameters, possibly due to the engagement of specific neurophysiological substrates. Abstract: A large variability in learning-related neurophysiological changes in the primary motor and sensory cortices has been observed. It is unclear whether these differential effects are due to the different tasks investigated or to interindividual variance. Only a few studies have assessed different motor-learning tasks and their effects on neurophysiological features within the same group of participants, and several issues are unclear. Here, we compared the effects of different tasks within each individual. We investigated the effects on motor and sensory cortex parameters after a model-free learning task, i.e. a ballistic motor task, compared with model-based learning tasks, i.e. visuomotor-learning tasks. Motor- and sensory-evoked potentials, intracortical excitability as assessed by short-interval intracortical inhibition, and sensorimotor interaction, i.e. short-latency afferent inhibition, were recorded from 15 healthy subjects before and after the tasks. The ballistic motor task induced an increase in corticospinal excitability but did not change motor cortex intracortical inhibition or sensorimotor integration. In addition, it decreased the amplitude of cortical components of the somatosensory-evoked potentials. The visuomotor-learning tasks induced a reduction in motor cortex intracortical inhibition but did not modulate corticospinal and sensory cortex excitability or sensorimotor integration. This differential modulation is likely to be secondary to the motor skill acquisition, since no correlation was observed between neurophysiological changes and motor performance. Our results demonstrate differential motor skill acquisition-related effects on cortical parameters, possibly reflecting the engagement of specific neurophysiological substrates, and contribute in-depth knowledge of the mechanisms involved in different types of motor skill acquisition in humans
Linee guida per un Piano di Azione per il miglioramento e la riorganizzazione del sistema di controllo e certificazione delle produzioni da agricoltura biologica
No full textAppropriate 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
- …
