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Coherence between an electroencephalogram (EEG) and an electromyogram (EMG) of the soleus (SOL) muscle during an isometric contraction is observed in the beta-band (15 to 35 Hz) regardless of the contraction force. However, the dynamics on how a variation in coherence occurs over time in the head of the gastrocnemius (GLH) muscle, which is also known to have the same role as the soleus muscle, have yet to be considered. In this study, we focused on GLH and measured an EEG and EMG taken of the GLH muscle when executing an isometric contraction through the dorsiflexion of the right ankle joint for a 1-min period. Moreover, we investigated changes in the EEG-EMG coherence based on the contraction force and elapsed time. As a result, in most subjects, the peak coherence during a weak contraction force was continuously observed in the β-band, whereas the peak coherence during a strong contraction force was observed in the γ-band (35 to 60 Hz) for only the first 12 s. In addition, no significant coherence was observed. Therefore, it was suggested that muscle fatigue induced by a strong contraction force affects the peak coherence. Meanwhile, the inconsistencies observed between the properties of the peak coherence and SOL might be due to the differences in muscle composition.

Riddles, such as "Why is A like B? Because they relate to C/C'," are a type of Japanese word game. The similarity between concepts in riddles reflect their semantic structures. In this research, the relationships between concept similarities and humor of the riddles were examined using the riddle-generation system on the Wikipedia corpus to cover enough concepts. The riddle-generation system provided riddles on the basis of similar concepts, which were estimated with word2vec using the Wikipedia corpus. The generated riddles were evaluated using the simulation results in order to clarify the relationships between concept similarities and humor. The experiment results suggested that riddles are funniest when the similarities between premises (A or B) and the reasons (C or C') are high and the similarity between the reasons themselves is low. Furthermore, an insufficient similarity between B and C' requires a sufficient amount of similarity between the reasons to elicit humor.

The coherence between electroencephalogram (EEG) and electromyogram (EMG) of the tibialis anterior (TA) muscle during isometric contraction is observed in the beta band (15 to 35 Hz). When the contraction force becomes stronger, the peak coherence frequency shifts to the gamma band (35 to 60 Hz). In contrast, based on the maintenance of contraction with the weak force, the peak coherence value increases. However, the manner in which coherence changes according to the maintenance of contraction with strong force remains unknown. In this study, five healthy male university students were directed to execute isometric contraction by dorsiflexion of their right ankle joint for 1 min with forces of 10 to 60% of the maximum voluntary contraction. During dorsiflexion, EEG and EMG of the TA muscle were performed. Then, the changes in coherence between EEG and EMG were examined, corresponding to the changes in contraction force and time course. In the majority of subjects, the peak coherence during the weak contraction force was observed in the beta band and lasted for 12 to 60 s. However, the peak coherence during the strong contraction force was observed in the gamma band only for the first 12 s. Subsequently, no significant coherence was observed. Therefore, muscle fatigue due to strong contraction forces and/or maintenance of the weak contraction force may have been observed as a different property of the peak coherence.

A new model triathlon suit (NMS) was developed to help the swimming performance of athletes. The NMS is made of highly compressed and highly water-repellent fabric, which is used in competitive swimwear. The aim of this study was to evaluate the NMS by measuring the passive drag and body position during underwater streamline position. The NMS and the old model suit (OMS) were worn by 11 highly competitive varsity swimmers (eight males and three females). The passive drag and body position were measured when both suits were worn in the circulating water channel. The coefficient of passive drag was calculated by the equation. On average, for the whole measurements, there was a reduction in passive drag when wearing the NMS suit of 1.1±5.3% compared with the OMS, whereas there was no statistically significant. The coefficient of the passive drag was not significant difference between both suits. Wearing the NMS showed higher body position compared to the OMS at any velocity, although not significantly. These results suggest that wearing the NMS might help improve swimming performance.

A new optimization system of cycling power was investigated in this paper. The developed system consisted of a newly designed biaxial load cells and analytical system using mechanical model of lower limb. The new biaxial load cells which were made by stainless steel (SUS304) were attached to the bottom of cycling-shoes instead of the plastic cleats. Cyclists are able to connect their cycling-shoes to pedals by the developed load cells. The sizes of load cells were almost same as plastic cleats (Shimano Corp) and measure the magnitude and direction of right and left pedal force using 16-strain gages, respectively. The analytical system solves the link model of human limbs to identify the positions and angles of each segment of lower limbs. The lower limbs model consisted of 3 segments, thigh, shank and foot. All position of every lower limb segments, joint torques and forces were calculated by this system. Additionally, the relationships between ankle angle and crank angle were also modelled by image-analysis software (TEMA 3D) with the high-speed camera (Photron FASTCAM SA4). This cycling power optimization system were applied to the amateur and expert cyclists to investigate applicability of our system.

This paper reports an investigation of enzymatic phosphorolysis of α(1→4)- linked oligo-d-glucosaminide substrates by thermo stable α-glucan phosphorylase (from Aquifex aeolicus VF5) catalysis. α-Glucan phosphorylase catalyzes both phosphorolysis and glucosylation/polymerization at the nonreducing end of α(1→4)-linked glucose substrates depending on conditions. The authors also found that α(1→4)-linked d-glucosaminide polymer (chitosan stereoisomer) was obtained by the thermostable α-glucan phosphorylase-catalyzed enzymatic polymerization of α-d-glucosamine 1-phosphate from a maltooligosaccharide primer. In the present study, we intend to reveal whether the enzyme catalyzes phosphorolysis of substrates containing such d-glucosaminide chains. The α(1→4)-linked oligo-d-glucosaminide substrates elongated from maltotriose were first prepared by the thermostable α-glucan phosphorylase-catalyzed enzymatic polymerization of α-d-glucosamine 1-phosphate from the maltotriose primer and subsequent purification by preparative HPLC. The phosphorolysis of the resulting substrates are conducted in the presence of thermostable α-glucan phosphorylase in phosphate buffer. The analytical results of the products fully supported the occurrence of phosphorolysis at the nonreducing end of both the chains of d-glucosamine-α(1→4)-d-glucosamine and d-glucosamine-α(1→4)-d-glucose sequences.

Thermostable α-glucan phosphorylase-catalyzed enzymatic copolymerization of α-d-glucose 1-phosphate (Glc-1-P) with its analogue monomer, α-d-glucosamine 1-phosphate (GlcN-1-P), from a maltotriose primer was performed to produce non-natural heteroaminopolysaccharides composed of Glc/GlcN units, that is, α(1→4)-linked glucosaminoglucans. The GlcN units in the products were further converted to N-acetyl-d-glucosamine (GlcNAc) units by N-acetylation. The structures of the products were evaluated by the MALDI-TOF MS, (1)H NMR, and (1)H-(1)H COSY NMR measurements, which were completely different from those of the natural glycosaminoglycans. The degrees of polymerization and Glc/GlcN compositional ratios of the products were relatively dependent on the Glc-1-P/Glc-1-P/Glc3 feed ratios. The noncrystalline natures of the present materials were supported by the X-ray diffraction measurement.

The relationship between two aminopolysaccharide stereoisomers, namely α-(1→4)- and β-(1→4)-linked (N-acetyl)-D-glucosamine polymers, is of significant interest within the field of polysaccharide science, as they correspond to amino analogs of the representative abundant natural polysaccharides, viz. amylose and cellulose. While the latter glucosamine polymer is the basis of well-known natural polysaccharides, chitin and chitosan (linear polysaccharides composed of β-(1→4)-linked N-acetyl-D-glucosamine and D-glucosamine), to the best of our knowledge, the former (α-(1→4)-linked) has not been observed in nature. For the purpose of these studies, the synthesis of such non-natural aminopolysaccharides was performed by the thermostable α-glucan phosphorylase (from Aquifex aeolicus VF5)-catalyzed enzymatic polymerization of α-D-glucosamine 1-phosphate (GlcN-1-P), via successive α-glucosaminylations, in ammonia buffer containing Mg(2+) ions, resulting in the production of the α-(1→4)-linked D-glucosamine polymers, corresponding to the structure of the chitosan stereoisomer. Subsequent N-acetylation of the products gave the aminopolysaccharides, corresponding to the chitin stereoisomer.

A visualization system for cycling pedaling technique is investigated in this paper. This system consists of the visualization of pedaling effectiveness and pedaling force vectors. Pedaling effectiveness is defined as the ratio of the tangential to total force applied to the pedals. New biaxial load cells were also developed to attach to the bottom of cycling shoes in place of plastic cleats. These load cells can be connected to the bicycle pedals to measure the magnitude and direction of pedaling forces of both pedals, respectively. The size of load cells is comparable with detachable plastic cleats (Shimano Corp). Therefore, cyclists were permitted to use their own bicycles for performance tests. For visualization of pedaling effectiveness, each force measured by the load cell was converted to coordinates respective to the tangential and radial directions of each crank. The crank angle was calculated from the signal of a magnetic transducer. The pedal angle was calculated using a link mechanism with the lower limbs: the length of the lower limbs, the length of the crank and the position of the greater trochanter were used as constant parameters for computational calculations. For visualization, the relationship between crank angle and force vectors was plotted on a computer, just after the performance tests. This information would be provided for coaches and cyclists in order to identify improvement points for pedaling technique.

A cystadenoma of the pancreas within the spleen from pancreatic heterotopia is described. The tumor was located in the hilum of the spleen and completely separated from the normal pancreatic tail. This fact strongly supports the possibility that this tumor arose from pancreatic heterotopia.