Predicting class probabilities and other real-valued quantities is often more useful than binary classification, but comparatively little work in PAC-style learning addresses this issue. We show that two rich classes of real-valued functions are learnable in the probabilisticconcept framework of Kearns and Schapire. Let X be a subset of Euclidean space and f be a real-valued function on X. We s...

We have experimentally observed uphill solitary waves in the surface flow on a granular material. A heap is constructed by injecting sand between two vertical glass plates separated by a distance much larger than the average grain size, with an open boundary. As the heap reaches the open boundary, solitary fluctuations appear on the flowing layer and move "up the hill" (i.e., against the direct...

Although the balance difficulties accompanying vestibular loss are well known, the underlying cause remains unclear. We examined the role of vestibular inputs in the automatic postural response (APR) to pitch and roll rotations of the support surface in freely standing cats before and in the first week after bilateral labyrinthectomy. Support surface rotations accelerate the body center of mass...

BACKGROUND Plantarflexor tightness due to muscle degenerations has been frequently documented in children with spastic cerebral palsy but the contractile behavior of muscles during ambulation is largely unclear. Especially the adaptability of gastrocnemius muscle contraction on sloped surface could be relevant during therapy. METHODS Medial gastrocnemius contractions were measured during flat...

Lizards commonly move on steep inclines in nature, but no previous studies have investigated whether the kinematics of the limbs of lizards differ on inclined surfaces compared with level surfaces. Therefore, we examined how the kinematics of the hindlimb were affected by both incline (downhill 30 degrees, level and uphill 30 degrees) and different speeds of steady locomotion (50-250 cm s-1) in...