ACTIVATION PATTERN OF TRUNK, THIGH AND LOWER LEG MUCLES DURING UNDERWATER DOLPHIN KICK IN SKILLED FEMALE SWIMMERS

This study investigated the muscle activation pattern between the agonist and the antagonist muscles in the trunk, thigh and lower leg during underwater dolphin kick. Thirteen female elite swimmers participated in this study and they performed 15 m underwater dolphin kick swimming at maximum effort. The surface electromyography (sEMG) of six muscles were measured and the muscle activation pattern between the agonist and antagonist muscles in the trunk, thigh and lower leg were estimated from the sEMG data. As results, the trunk and the thigh muscles showed a reciprocal activation pattern during one-kick cycle. However, the activation pattern of the lower leg muscles did not show a reciprocal pattern and it was clarified that the lower leg muscles were co-activated during the upward kick phase

Parameter identification of nonlinear viscoelastic model with impact area parameter for sport surface by using multi-intensity multi-area impact test

AbstractIn previous studies, we proposed various models of material and methods for identifying the parameters of these models by multi-intensity impact test. Especially, the exponential funtion type nonlinear Voigt model shows an excellent accuracy for identifying the property of material behavior. Although other papers show that this model is applicable to the case of varying impact duration and various temperatures, we have not yet discussed how the properties would change as the impact area changed. The purpose of this study is to propose an identification technique of nonlinear Voigt model with hysteresis and dependence on impact area by multi-intensity multi-area impact test. The nonlinear elastic element of this model is expressed by the exponential function based on displacement and impact area. And the nonlinear viscous element of the model is expressed by the product of the exponential function based on displacement and the exponential function based on velocity

二種の血清型特異性,すなわち血清型4のVP3と血清型3のVP7を有する組換え体ヒトロタウイルスの作製

The reassortment of viral genome segments has been reported to occur during coinfection of cultured cells with two different rotaviruses. Further, epidemiologic findings suggesting that genetic reassortment of viral RNAs may account for an antigenic shift in rotavirus in nature have also been accumulated. In the present study a reassortant virus, C148, was selected from fifty-one progeny virus clones obtained under an antibody pressure from a mixed infection of MA104 cells with human rotavirus serotype 3 (YO) and serotype 4 (Hochi) strains. Antigenic characterization and genotype analysis by polyacrylamide gel electrophoresis concluded that C148 virus possessed a mosaic antigenicity defined by two serotype-specific viral proteins (VP), i. e. the serotype 4-specific VP3 and the serotype 3-specific VP7. While the reassortant C148 was judged to belong to serotype 3 on the basis of its preferential neutralizability by serotype 3 antiserum, the antiserum prepared against C148 equally neutralized both serotype 3 and 4 viruses. These results seem to further support the possible emergence of a genetic reassortant in nature between human rotaviruses beloneinu to different serotypes

Tonic B cell activation by Radioprotective105/MD-1 promotes disease progression in MRL/lpr mice

Toll-like receptors (TLRs) have a crucial role in sensing microbial products and triggering immune responses. Recent reports have indicated that TLR7 and TLR9 have an important role in activating autoreactive B cells. In addition to TLR7 and TLR9, mouse B cells express TLR2, TLR4 and structurally related Radioprotective105 (RP105). We have previously shown that RP105 works in concert with TLR2/4 in antibody response to TLR2/4 ligands. We here report that B cells are constitutively activated by TLR2/4 and RP105. Such B cell activation was revealed by the γ3 germ line transcript and serum IgG3 production, both of which were impaired by the lack of RP105 or TLR2/4. Serum IgG3 was not altered in germ-free or antibiotics-treated mice, suggesting that the microbial flora hardly contributes to the continuous activation of B cells. The lack of RP105-dependent B cell activation ameliorated disease progression in lupus-prone MRL/lpr mice. RP105−/− MRL/lpr mice showed less lymphoadenopathy/splenomegaly and longer survival than MRL/lpr mice. Whereas glomerulonephritis and auto-antibody production were not altered, improvement in blood urea nitrogen and lower incidence of renal arteritis indicated that renal function was ameliorated in the absence of RP105. Our results suggest that RP105-dependent tonic B cell activation has a pathogenic role in MRL/lpr mic

Evidence for Activation of Toll-Like Receptor and Receptor for Advanced Glycation End Products in Preterm Birth

Objective. Individuals with inflammation have a myriad of pregnancy aberrations including increasing their preterm birth risk. Toll-like receptors (TLRs) and receptor for advanced glycation end products (RAGE) and their ligands were all found to play a key role in inflammation. In the present study, we reviewed TLR and RAGE expression, their ligands, and signaling in preterm birth. Research Design and Methods. A systematic search was performed in the electronic databases PubMed and ScienceDirect up to July 2010, combining the keywords “preterm birth,” “TLR”, “RAGE”, “danger signal”, “alarmin”, “genomewide,” “microarray,” and “proteomics” with specific expression profiles of genes and proteins. Results. This paper provides data on TLR and RAGE levels and critical downstream signaling events including NF-kappaB-dependent proinflammatory cytokine expression in preterm birth. About half of the genes and proteins specifically present in preterm birth have the properties of endogenous ligands “alarmin” for receptor activation. The interactions between the TLR-mediated acute inflammation and RAGE-mediated chronic inflammation have clear implications for preterm birth via the TLR and RAGE system, which may be acting collectively. Conclusions. TLR and RAGE expression and their ligands, signaling, and functional activation are increased in preterm birth and may contribute to the proinflammatory state

エリート女性競泳選手の水中ドルフィンキックにおける体幹，大腿，下腿の筋活動様式

 The purpose of this study was to clarify the pattern of muscular activity in the trunk, thigh and lower leg during the underwater dolphin kick in elite female competitive swimmers. The participants were 9 national-level competitive female swimmers who performed underwater dolphin kick swimming for 15 m at maximum effort. Sagittal movement was recorded for 2-D motion analysis, and surface electromyographic (EMG) data were recorded from 6 muscles: rectus abdominis (RA), elector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GAS). The EMG data were used to investigate the active phase during one kick cycle. Furthermore, the co-active phases between the agonist and the antagonist in the trunk, thigh and lower leg were evaluated in terms of estimated muscular coordination. The kinematic results indicated that the average swimming velocity and the strouhal number for these swimmers were similar to those for Olympic swimmers in a previous study. Furthermore, a whiplash-like action was observed in their underwater dolphin kick movement. The EMG results indicated that the active phases of all subjective muscles during one kick cycle were approximately 60%. Co-active phases were observed in all pairs (RA-ES: 24.1±10.1%, RF-BF: 23.2±5.5%, TA-GAS: 45.5±20.2%), and the co-active phase of TA-GAS was significantly larger than for the other pairs (p<0.05). From these results, two main findings emerged with regard to the muscular activity pattern during the underwater dolphin kick in elite female competitive swimmers: (1) the muscular activity patterns in the trunk and thigh muscles were reciprocal; (2) the co-active phase for the lower leg muscles was larger than for the other parts and occurred during the first half of the upward kick phase