Thibaudier Y, Hurteau MF. Sensory regulation of quadrupedal locomotion: a top-down or bottom-up control system? J Neurophysiol 108: 709-711, 2012. First published April 18, 2012;doi:10.1152/jn.00302.2012.-Propriospina...
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Thibaudier Y, Hurteau MF. Sensory regulation of quadrupedal locomotion: a top-down or bottom-up control system? J Neurophysiol 108: 709-711, 2012. First published April 18, 2012;doi:10.1152/jn.00302.2012.-Propriospinal pathways are thought to be critical for quadrupedal coordination by coupling cervical and lumbar central pattern generators (CPGs). However, the mechanisms involved in relaying information between girdles remain largely unexplored. Using an in vitro spinal cord preparation in neonatal rats, Juvin and colleagues (Juvin et al. 2012) have recently shown sensory inputs from the hindlimbs have greater influence on forelimb CPGs than forelimb sensory inputs on hindlimb CPGs, in other words, a bottom-up control system. However, results from decerebrate cats suggest a top-down control system. It may be that both bottom-up and top-down control systems exist and that the dominance of one over the other is task or context dependent. As such, the role of sensory inputs in controlling quadrupedal coordination before and after injury requires further investigation.
The notion that strategies in non-linear and combinatorial optimization can benefit by purposefully and systematically navigating between feasible and infeasible space has been around for many years, but still is some...
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The notion that strategies in non-linear and combinatorial optimization can benefit by purposefully and systematically navigating between feasible and infeasible space has been around for many years, but still is sometimes dismissed as having little relevance for creating more effective methods. To reinforce the case on behalf of approaches that endorse infeasible/feasible search trajectories, it is possible to formulate simple theorems disclosing useful properties of such trajectories in the context of integer programming. These results motivate a closer examination of integer programming search processes based on directional rounding processes, including a special variant called conditional directional rounding. From these foundations a variety of new strategies emerge for exploiting connections between feasible and infeasible space.
The role of plasma, UV/ozone, laser and carbon dioxide in cleaning process is discussed. It is found that plasma cleaning systems use excited gas-plasma to chemically crack and dislodge contaminants from the part'...
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The role of plasma, UV/ozone, laser and carbon dioxide in cleaning process is discussed. It is found that plasma cleaning systems use excited gas-plasma to chemically crack and dislodge contaminants from the part's surface. It is observed that due to low viscosity and surface tension, supercritical CO 2 (SCCO2) is able to penetrate pores and crevices.
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