Effects of Repetitive Finger Movements on the Short-Latency Somatosensory-Evoked Potentials

When performing a movement, many features of sensory information are used as inputs and integrated. Smooth movement is possible by selecting necessary information from all‐sensory inputs. The somatosensory input of movement is adjusted at different levels such as at the level of the spinal cord, brainstem, and sensory cortex. However, sensory tests used by physical therapists provide only the sensory information that is perceivable through the parietal association fields. On the other hand, there is a somatosensory‐evoked potentials (SEPs) in the tests of the somatic sensory function. An understanding of the SEPs enables the evaluation of the posterior track. Therefore, it is possible to determine if the adjustment of somatosensory inputs occurs at any stage. The SEP amplitude is decreased by passive and voluntary movement. Further, characteristic decrease in the SEP amplitude is noted with an increase in the speed and intensity of movement. Thus, it is important for us to understand the relationship between motor tasks and somatosensory inputs. In this chapter, we introduce our study on the relationship between physical movements and somatosensory inputs, and make recommendations for practicing physical therapy

Unconventional critical scaling of magnetization in uranium ferromagnetic superconductors UGe2_2 and URhGe

We report a dc magnetization study of the critical phenomenon around the ferromagnetic transition temperature T_C in high-quality single crystals of uranium ferromagnetic superconductors UGe2 and URhGe. The critical exponents, beta for the temperature dependence of the magnetization below T_C, gamma for the magnetic susceptibility, and delta for the magnetic isothermal at T_C have been determined with a modified Arrott plot, a Kouvel-Fisher plot, and the scaling analysis. Magnetization in the ferromagnetic state has strong uniaxial magnetic anisotropy in the two compounds. However, the universality class of the critical phenomena do not belong to the three dimensional (3D) Ising system. Although the values of beta in UGe2 and URhGe are close to those in the 3D magnets, the values of gamma are close to unity, that expected from the mean field theory. Similar critical exponents have been reported previously for the 3D Ising ferromagnet UIr where superconductivity appears under high pressure. The critical behavior may be limited to a very narrow Ginzburg critical region of 1 mK because of the strong itinerant character of the 5f electrons in the ferromagnetic superconductor UCoGe where the mean field behavior of the magnetization has been reported. The unconventional critical scaling of magnetization in UGe2, URhGe and UIr cannot be explained via previous approaches to critical phenomena. The ferromagnetic correlation between the 5f electrons differs from that in the 3D Ising system and this difference may be a key point for the understanding of the ferromagnetism where superconductivity emerges.Comment: 8 pages, 5 figure

PRELIMINARY ASSESSMENT OF THE EFFECT OF TRAPEZE POSTURES ON RIGHTING FORCE IN SAILING

This study examined the effect of change of “Trapeze” postures in sailing on the horizontal force for righting the boat. Three healthy university sailors participated. The subjects were instructed to successively change their trapeze posture. The traction force of the wire was measured from which its horizontal component for righting the boat (FH) was computed. A distinct change of FH was observed when the subjects extend their legs during trapezing. From this result, it can be suggested that the change of the trapeze posture by extending the leg linked to expand the angle between the wire and mast, thereby contributing to the increase the resultant FH