87,551 research outputs found
Analysis of unsupported gait in toddlers with autism
No full textAnalysis of unsupported gait in toddlers with autism.
Esposito G, Venuti P, Apicella F, Muratori F.
Department of Cognitive Science and Education, University of Trento, Italy.
[email protected]
AIMS: A number of studies have suggested the importance of motor development in
autism. Motor development has been considered a possible bio-marker of autism
since it does not depend on either social or linguistic development. In this
study, using retrospective video analysis we investigated the first unsupported
gait in toddlers with autism.
METHODS: Fifty-five toddlers, belonging to three groups were recruited: toddlers
with autistic disorder (AD, n=20, age 14.2mo, sd 1.4mo) and as comparison groups:
typically developing toddlers (TD, n=20, age 12.9mo, sd 1.1mo) and toddlers with
non-autistic developmental delays of mixed aetiology (DD, n=15, age 13.1mo, sd
0.8mo). The Walking Observation Scale (WOS) and the Positional Pattern for
Symmetry during Walking (PPSW) were used to gather data on the first unsupported
gait. The WOS includes 11 items that analyze gait through three axes: foot
movements; arm movements; general movements while the PPSW analyses static and
dynamical symmetry during gait.
RESULTS: Our results have identified significant differences in gait patterns
among the group of toddlers with AD as opposed to the control groups. Significant
differences between AD and the two control groups were found for both WOS
(p<.001) and PPSW (p<.001).
CONCLUSION: The specificity of motor disturbances we have identified in autism
(postural asymmetry) is consistent with previous findings that implicated
cerebellar involvement in the motor symptoms of autism
Il manoscritto Ambrosiano B 36 inf. testimone del Liber Glossarum
No full textThis paper aims to give a new reference for the codex Ambrosianus B 36 inf. (manuscript A in the Liber Glossarum tradition); it is\ud
divided into three main parts. The first section provides a general description of the manuscript analyzing pagination, physical conditions,\ud
omissions, etc.; the second section highlights specific features of the Milanese manuscript, especially as concerns the endpapers, signatures, ancient annotations; the\ud
third section offers a short historical information about the circulation of the manuscript before it entered the Ambrosiana collection
Numerical validation of the generalized equivalent spectral model through crowd dynamics simulations
No full textThis paper aims to provide a validation of the Generalized Equivalent Spectral Model of pedestrian-induced loading through numerical simulations of crowd dynamics. Pedestrian flows with varying density are numerically simulated based on the social force model. The instantaneous step frequency of each pedestrian is obtained from his instantaneous velocity. Results obtained from numerical simulations are statistically analyzed to obtain probability density functions of the step frequency. Then, each pedestrian is modelled as a moving harmonic load, whose trajectory and velocity are obtained from crowd simulations. The power spectral density function of the modal force obtained from numerical simulations is then compared with the analytical expression provided by the Generalized Equivalent Spectral Model. Possible modifications of the original formulation are analyzed, in order to fit numerical results
Human-induced loading and dynamic response of footbridges in the vertical direction due to restricted pedestrian traffic
No full textDespite extensive research in the field of human-induced vibration in the last twenty years, there is
still lack of reliable load and response models to assess vibration serviceability of footbridges under
human-induced excitation, especially with reference to crowded conditions. This paper aims to provide
a reliable characterization of pedestrian-induced loading on footbridges in restricted traffic condition,
and to compare the reliability of current guidelines and advanced spectral models in the serviceability
assessment of footbridges with respect to vertical vibrations. Numerical simulations of restricted pedestrian traffic are carried out through an agent-based model, considering variable pedestrian densities
and deck widths. The probability distribution of the step frequency and the power spectral density
function of the modal force are obtained numerically. Based on the numerical results, a Modified
Generalized Equivalent Spectral Model is proposed. Finally, two numerical examples are analyzed to
assess the reliability of current guidelines and of the Modified Generalized Equivalent Spectral Model
in the estimate of the maximum footbridge acceleration
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