42 research outputs found

    Differences in muscle power between the dominant and nondominant upper limbs of baseball players

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    We examined the differences in muscle power between the dominant and nondominant upper limbs of 33 healthy, right-handed, university baseball players (mean age, 20.4±1.1 years) with an average baseball experience >11 years. After measuring maximal voluntary contraction (MVC) of hand grip, elbow flexion, and shoulder internal rotation in both upper limbs, the muscle power of each joint was measured at 40%, 50%, and 60% MVC. No significant differences were observed in the main factors affecting MVC and elbow flexion power loads between dominant and nondominant upper limbs. For handgrip power, load factors at 40% MVC in the dominant hand were lower than those at 60% MVC in the same hand and those at 50% and 60% MVC in the nondominant hand. Significant differences were observed in shoulder internal rotation power between dominant and nondominant upper limbs, with the dominant limb having greater power at all loads. Correlations between muscle power of both upper limbs for handgrip and elbow flexion were significant and moderately high at all loads. For shoulder internal rotation power, the degree of correlation was significant and moderately high at 40% MVC but low to moderate at 50% and 60% MVC. Therefore, baseball players have marked lateral dominance in shoulder internal rotation power unlike handgrip and elbow flexion power, although the relationship between shoulder internal rotation muscle powers of both upper limbs becomes lower with increasing load. The dominance of muscle power of each joint varied even in the same upper limb. It is thus beneficial for baseball players to train with even loads on both arms or adopt simultaneous workout of both arms after adjusting for strength differences. © 2013 National Strength and Conditioning Association

    Age differences between the controlled force exertion measured by a computer-generated sinusoidal and a bar chart display

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    It is important to develop an accurate method of measuring controlled force exertion. This study examined the age differences between the controlled force exertion measured by a sinusoidal waveform and a bar chart display. The participants comprised 175 right-handed male adults aged 20-86 years. The participants were divided into three age groups: young (n=53), middle-aged (n=71), and elderly (n=51). They matched the submaximal grip strength exerted by their dominant hand to changing demand values displayed as either a sinusoidal waveform or a bar chart appearing on a personal computer screen. The participants performed the controlled force exertion test three times with a 1-min inter-trial interval using their dominant hand. The dependent variable was the total sum of the percentage values of the differences between the demand value and grip exertion value for more than 25s. The coefficient of variance had almost the same range in all age groups in both displays (CVSW=28.0-36.9, CVBC=29.1-32.6), but the elderly group showed a somewhat higher value with the sinusoidal waveform. Significant correlations were found between the scores with sinusoidal waveform and bar chart displays in the young, middle-aged, and elderly groups (r=0.47-0.68), but the correlations did not differ significantly between the age groups. Scores over 1500% in sinusoidal and bar chart display were found in one and two participants, respectively, in the middle-aged group and in 12% and 16% of the participants, respectively, in the elderly group. Furthermore, among all participants, only 8% of participants in the elderly group scored over 1500% in both displays. Scores over 1500% in both displays are considered to be considerably worse in controlled force exertion than lower scores. © 2013 Elsevier Ireland Ltd

    Effect of maximum grip strength on controlled force exertion measured by a computer-generated sinusoidal waveform in young adult males

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    Context: It is important to develop a method to accurately measure controlled force exertion (CFE). Objectives: This study aimed to examine the effect of maximum grip strength on CFE measured by a sinusoidal waveform in 81 right-handed young males aged 15-29 years. Methods: On the basis of grip strength measurements, participants were divided into the following three groups: low (males 20; mean age 19.5 years; standard deviation (SD) = 5.0 years), medium (males 41; mean age 22.8 years; SD = 4.2 years), and high (males 20; mean age 23.7 years; SD = 3.4 years). Participants adjusted the submaximal grip strength of the dominant hand with changes in the demand values that were displayed as a sinusoidal waveform with a frequency of 0.1 Hz on a computer screen. The abovementioned test was performed three times with a 1-min interval after one practice trial. Each trial lasted 40 s. The sum of the differences between the demand value and grip exertion strength value for 25 s was considered as the evaluation parameter. Results: Controlled force exertion values demonstrated insignificant correlations with age and maximum grip strength in all groups (r = 0.07; r = -0.12; p > 0.05). No significant differences were found between CFE mean scores that was adjusted for age and varying maximum grip strength in the three groups (F = 1.95; p > 0.05). Conclusions: Based on the sinusoidal waveform display, we inferred that maximum grip strength has little effect on CFE evaluation in young males. © 2014 Springer-Verlag Italia

    A flexible representation of omic knowledge for thorough analysis of microarray data

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    BACKGROUND: In order to understand microarray data reasonably in the context of other existing biological knowledge, it is necessary to conduct a thorough examination of the data utilizing every aspect of available omic knowledge libraries. So far, a number of bioinformatics tools have been developed. However, each of them is restricted to deal with one type of omic knowledge, e.g., pathways, interactions or gene ontology. Now that the varieties of omic knowledge are expanding, analysis tools need a way to deal with any type of omic knowledge. Hence, we have designed the Omic Space Markup Language (OSML) that can represent a wide range of omic knowledge, and also, we have developed a tool named GSCope3, which can statistically analyze microarray data in comparison with the OSML-formatted omic knowledge data. RESULTS: In order to test the applicability of OSML to represent a variety of omic knowledge specifically useful for analysis of Arabidopsis thaliana microarray data, we have constructed a Biological Knowledge Library (BiKLi) by converting eight different types of omic knowledge into OSML-formatted datasets. We applied GSCope3 and BiKLi to previously reported A. thaliana microarray data, so as to extract any additional insights from the data. As a result, we have discovered a new insight that lignin formation resists drought stress and activates transcription of many water channel genes to oppose drought stress; and most of the 20S proteasome subunit genes show similar expression profiles under drought stress. In addition to this novel discovery, similar findings previously reported were also quickly confirmed using GSCope3 and BiKLi. CONCLUSION: GSCope3 can statistically analyze microarray data in the context of any OSML-represented omic knowledge. OSML is not restricted to a specific data type structure, but it can represent a wide range of omic knowledge. It allows us to convert new types of omic knowledge into datasets that can be used for microarray data analysis with GSCope3. In addition to BiKLi, by collecting various types of omic knowledge as OSML libraries, it becomes possible for us to conduct detailed thorough analysis from various biological viewpoints. GSCope3 and BiKLi are available for academic users at our web site

    Immunological profile in a family with nephrogenic diabetes insipidus with a novel 11 kb deletion in AVPR2 and ARHGAP4 genes

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    <p>Abstract</p> <p>Background</p> <p>Congenital nephrogenic diabetes insipidus (NDI) is characterised by an inability to concentrate urine despite normal or elevated plasma levels of the antidiuretic hormone arginine vasopressin. We report a Japanese extended family with NDI caused by an 11.2-kb deletion that includes the entire <it>AVPR2 </it>locus and approximately half of the <it>Rho GTPase-activating protein 4 </it>(<it>ARHGAP4</it>) locus. ARHGAP4 belongs to the RhoGAP family, Rho GTPases are critical regulators of many cellular activities, such as motility and proliferation which enhances intrinsic GTPase activity.</p> <p>ARHGAP4 is expressed at high levels in hematopoietic cells, and it has been reported that an NDI patient lacking <it>AVPR2 </it>and all of <it>ARHGAP4 </it>showed immunodeficiency characterised by a marked reduction in the number of circulating CD3+ cells and almost complete absence of CD8+ cells.</p> <p>Methods</p> <p>PCR and sequencing were performed to identify the deleted region in the Japanese NDI patients. Immunological profiles of the NDI patients were analysed by flow cytometry. We also investigated the gene expression profiles of peripheral blood mononuclear cells (PBMC) from NDI patients and healthy controls in microarray technique.</p> <p>Results</p> <p>We evaluated subjects (one child and two adults) with 11.2-kb deletion that includes the entire <it>AVPR2 </it>locus and approximately half of the <it>ARHGAP4</it>. Hematologic tests showed a reduction of CD4+ cells in one adult patient, a reduction in CD8+ cells in the paediatric patient, and a slight reduction in the serum IgG levels in the adult patients, but none of them showed susceptibility to infection. Gene expression profiling of PBMC lacking <it>ARHGAP4 </it>revealed that expression of RhoGAP family genes was not influenced greatly by the lack of <it>ARHGAP4</it>.</p> <p>Conclusion</p> <p>These results suggest that loss of <it>ARHGAP4 </it>expression is not compensated for by other family members. ARHGAP4 may play some role in lymphocyte differentiation but partial loss of <it>ARHGAP4 </it>does not result in clinical immunodeficiency.</p

    Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome.

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    The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP
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