The ability to sustain steady straight-ahead walking is one goal of gait rehabilitation for individuals with unilateral above-knee (UAK) amputation. Despite the morphological and musculoskeletal asymmetry resulting from limb loss, mediolateral ground-reaction-impulse (GRI) should be counterbalanced between affected unaffected limbs during walking. Therefore, we investigated strategies ground-re...

According to the Gri th criterion, a crack propagation occurs provided that the derivative of the energy functional with respect to the crack length reaches some critical value. We consider a generalization of this criterion to the case of nonlinear cracks satisfying a non-penetration condition and investigate the dependence of the shape derivative of the energy functional on the crack shape. I...

Spiral arms, if they are massive, exert gravitational torques on stars that transport angular momentum radially within galactic disks. These torques depend not on the pattern speed or permanence of the arms but only on the nonaxisymmetric mass distribution. Hence the torques can be measured directly from photometry. We demonstrate this using gri CCD data for M100 (NGC 4321). Since we nd consist...

We survey recent work on normal functions, including limits and singularities of admissible normal functions, the Gri ths-Green approach to the Hodge conjecture, algebraicity of the zero-locus of a normal function, Néron models, and MumfordTate groups. Some of the material and many of the examples, esp. in §§5− 6, are original. In a talk on the theory of motives, A. A. Beilinson remarked that a...