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New findings What is the central question of this study? When performing skilful hand movement, motor command descends especially towards distal arm muscles. Does central command evoke a vascular response selectively in the distal arm muscles during skilful hand movement? What is the main finding and its importance? We found, using near-infrared spectroscopy, that unilateral skilful hand movement evoked a greater increase in oxygenation of the contralateral forearm muscle compared with that of the upper arm muscles. Mental imagery of the hand movement also increased oxygenation of the forearm muscle. These findings suggest that central command might contribute to the vasodilator response in the non-contracting forearm muscle during contralateral skilful hand movement. Abstract The human hand is a special organ to perform skilful movement in daily life. To meet metabolic demands of the working distal arm muscles, central command might evoke neurogenic vasodilatation in the muscles. Based on our previous demonstration that a centrally generated vasodilator signal is transmitted bilaterally to skeletal muscles during exercise, centrally induced vasodilatation might occur in the non-contracting distal arm muscles during contralateral skilful hand movement. To examine this possibility, we used near-infrared spectroscopy to measure the relative concentrations of oxygenated haemoglobin (Oxy-Hb; as an index of regional blood flow) in the non-contracting arm muscles during skilful hand movement (two-ball rotation) in 22 subjects. Two-ball rotation increased Oxy-Hb of both forearm and upper arm muscles, with little changes in perfusion pressure and cardiac output. The increased Oxy-Hb was greater in the forearm muscle than in the upper arm muscles. The increased Oxy-Hb of the forearm muscle during two-ball rotation was greater than that during one-armed cranking performed with no load. Mental imagery of two-ball rotation increased Oxy-Hb of the forearm and biceps muscles. The increases in Oxy-Hb of both forearm and upper arm muscles during two-ball rotation were reduced by decreasing the level of task difficulty. Intravenous administration of atropine attenuated the increases in Oxy-Hb of the arm muscles during two-ball rotation. It is likely that contralateral skilful hand movement evokes a selective increase in Oxy-Hb of the non-contracting forearm muscle via a sympathetic cholinergic mechanism and that the increase in oxygenation might be mediated, at least in part, by central command.

A stacked device called SEP (System Embedded Package) was developed to drastically increase LSI density relative to its area on the circuit board. This was achieved by fabricating an LSI package in a stacked structure. This device has been applied to mobile communication equipment. The bottom-side chip was made into a flip-chip structure and attached to the substrate by the NSD method, which involves the use of stud-bumps and adhesive encapsulation film. On the top of this flip-chip LSI, another LSI was stacked and interconnected by using low-profile wire-bonding technology. The use of flip-chip bonding for the bottom-side LSI permitted easy wire bonding on the topside LSI. Furthermore, this packaging technology was able to provide a super multi-pin system LSI with more than 600 pins. By adopting this package in a mobile communication product, the required package area on the circuit board could be reduced by 35%.

A dynamic analysis of free-piston Vuilleumier cycle heat pumps was carried out by a timestepping integration technique. The effects of external alternate force exciting a hot displacer piston upon the frequency response were taken into consideration as well as the viscous dissipation due to oscillating flow of working gas. We obtained a stable operation range in which the heat pump cycle is controllable and the cycle can be started with fairly small power on the external alternate force vs. operating frequency diagram. A mechanism to determine the amplitudes was explained based on the energy balance among the work done by the rod and by the dissipative and external forces. The internal force of the rod was found to play an important role in determining resonance frequencies.