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The relation between occlusal force and general motor ability induced by lower-limb musculature is unclear. To identify indicators of oral and lower-limb muscle weakness, this study examined the relation between masticatory muscle strength and lower limb muscle force in 742 community-dwelling elderly adults (315 men and 427 women, mean age 733 +/- 5.5 years) living in Itabashi ward, Tokyo. Multiple regression analysis of the relation between occlusal force and knee extension torque, in relation to age and sex, showed a significant correlation between the two variables (r = 0.348, P < 0.001), which indicates that occlusal force is a determinant of knee extension torque. Occlusal force remained significantly correlated with knee extension torque after adjustment for factors known to be related to the latter. In conclusion, chewing function and lower-limb motor function were significantly correlated and thus might be indicators of muscle weakness in elderly adults.

To use millimeter wave bands in future cellular and wireless networks, characterization of the radio propagation channel in outdoor urban small cell or pico cell environment is vital. In this paper we present results from analysis of wideband full polarimetric directional channel measurements in an urban pico-cell environment using the double directional millimeter wave channel sounding system we developed. Multipath clusters with excess gain ranging from −9.6 dB to −22 dB in both line of sight (LOS) and obstructed LOS cases are seen. The most significant clusters were due to first and second order reflection, and diffraction. The clusters ranged from being highly specular in nature with very small (nearly 0°) angular spread to having angular spreads of up to 5.8° in azimuth and 6.3° in elevation. Similarly the delay spread of the clusters ranged up to 2.1 ns.

Purpose of the study Sarcopenia has been identified as a health hazard in elderly people. Although the association between sarcopenia and a decrease in masticatory function has been reported, the mechanism underlying this association has not been widely reported. Therefore, in order to elucidate the relationship between sarcopenia and masticatory function, we examined whether the masseter muscle thickness (MMT), which is a factor influencing masticatory function, in community-dwelling elders is associated with the appendicular skeletal muscle index (SMI), a diagnostic criterion for sarcopenia. Materials and methods MMT was measured in 774 community-dwelling elders aged 65 years or older at resting state via ultrasonography, and SMI was measured with the bioelectrical impedance method. The relationships were investigated by calculating Pearson's correlation coefficients. Multiple regression analyses adjusted for age and sex, SMI, and oral-related items were performed to determine the association between these factors. Results There was a significant correlation between the MMT and the SMI. The multiple regression analysis indicated that SMI was significantly associated with a decrease in MMT. Conclusions The reduction in whole-body skeletal muscle mass in sarcopenia may be involved in the reduction in MMT. Prevention of sarcopenia may be an important factor for maintaining masticatory function in the elderly.

In order to utilize higher frequency bands above 6 GHz which is an important technical challenge in fifth generation mobile systems and ultra-high speed WLANs, radio propagation channel properties in large variety of deployment scenarios should be thoroughly investigated. This paper presented measurement results in an atrium entrance hall environment at an millimeter-wave band of 58.5 GHz assuming an indoor hotspot access scenario. In this measurement, the channel transfer functions of a wideband signal with 400 MHz bandwidth were measured by rotating high gain horn antennas with 12 and 30 degree half power beamwidth at 25 receiver positions. From the measured double-directional angular delay power spectrum, the multi-path clusters were roughly identified by local peak detection. This paper presented delay and angle domain inter-cluster characteristics and identified the propagation mechanism of each cluster comparing with ray tracing simulation. The measurement results revealed that the dominant mechanisms of the multi-path clusters are the first-order specular reflection from environment specific large walls and scattering by columns and square pillars.

This paper presented dominant propagation mechanisms in an outdoor open area environment through the channel measurement and ray-tracing (RT) simulation at an mm-wave band of 58.5 GHz assuming an outdoor hotspot access scenario in 5G mobile systems and WLANs. From the data analysis, multi-path clusters by first- and second-order reflection, first-order diffraction and scattering mechanisms were identified. The measurement result revealed that the multi-path clusters have relatively small power less than approximately 20 dB to the direct path other than first-order reflection from nearby buildings that can be predicted in a deterministic manner, and the channel can be well expressed by the quasi-deterministic (Q-D) channel model which supports natural description of environment-specific deterministic components separately from the other random components. Based on Q-D model, this paper presented extracted statistical channel model parameters of the random components by using RT simulation.