1,720,974 research outputs found
The sway density curve and the underlying postural stabilization process.
No full textThe sway-density curve (SDC) is computed by counting, for each time instant, the number of consecutive samples of the statokinesigram falling inside a circle of "small" radius R. The authors evaluated the sensitivity of the curve to the variation of R and found that in the range 3-5 mm the sensitivity was low, indicating that SDC is a robust descriptor of posturographic patterns. In addition, they investigated the relationship between SDC and the underlying postural stabilization process by decomposing the total ankle torque into three components: a tonic component (over 69% of the total torque), an elastic torque caused by ankle stiffness (about 19%), and an anticipatory active torque (about 12%). The last component, although the smallest in size, is the most critical for the overall stability of the standing posture and appears to be correlated with the SDC curve
FUNCTIONAL EFFECT OF SHORT-TERM IMMOBILIZATION: KINEMATIC CHANGES AND RECOVERY ON REACHING-TO-GRASP
No full textAlthough previous investigations agree in showing significant cortical modifications related to short-term limb immobilization, little is known about the functional changes induced by non-use. To address this issue, we studied the kinematic effect of 10. h of hand immobilization. In order to prevent any movement, right handed healthy participants wore on their dominant hand a soft bandage. They were requested to perform the same reaching-to-grasping task immediately after immobilization, 1. day before (baseline 1) and in other two following days without non-use (baseline 2 and baseline 3). While no differences were found among baseline conditions, an increase of the total duration of reaching movement together with an anticipation of the time to peak velocity were observed in the first trial after immobilization. Interestingly, these initial effects decreased quickly trial-by-trial, following an exponential function till reaching values equal to those observed in the control conditions. The present findings show firstly that the transport phase of the reaching-to-grasp task was affected by a temporary reduction of sensory and motor information. Secondly, a trial-by-trial recovery of the immobilization-related changes, likely driven by the sensory inputs and motor outputs associated to the repetition of the movement has been observed. All together these results confirm a fundamental role of a continuous stream of sensorimotor signals in maintaining motor efficiency and in driving recovery process. © 2012 IBRO
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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