46 research outputs found

    THE COMPARSION OF CURVATURE RADIUS IN DIFFERENT PERFORMANCES

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    The purpose of this study was to compare the curvature radius of different performance (63.20m and 68.46m) of hammer throw. The subject, who is the present record holder in Taiwan, has 9 years of experience in hammer throw. Two Peak-Performance high-speed video cameras operating at 120Hz were used simultaneously to record the performances of the subject. The results indicated that the patterns were completely different between two performances of hammer throw. The better performance was more periodic than the other. Based on the results of this study, it has been suggested that other sport events that include aspects of rotation may also benefit by adjustment of the pattern from their curvature radius

    THE APPLICATION OF RANGE OF MOTION (ROM) AND COORDINATION ON VOLLEYBALL SPIKE

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    The purpose of this study was to investigate the suitable timing and coordination of body segments during volleyball spike, and find the critical concepts applied on spikinglearning in the air. Cinematography (250 frame/sec, sagittle plane) was used in this study, and Kwon 3D software was used to analyze the timing and coordination of arm swing motion in the air among top and second level female volleyball athletes. The results of this study as following: 1. Enough range of motion (ROM) before ball hitting is the main factor of spiking technique; 2. Proper time-distribution of back-swing, turn-swing and forward-swing cause the proper time of ball hitting. The conclusion of spiking technique was described as following hint concepts: 1. “lead”: leading back swing at the beginning of takeoff, 2. “pull”: back swing by pull of elbow and wrist, simultaneously. 3. “turn”: make a enough ROM of swing phase. 4. “up”: during up, 5. “hit”:hitting ball by arm and body momentum

    KINEMATIC ANALYSIS OF TENNIS VOLLEY

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    The purpose of this study was to examine selected kinematic variables of the tennis volley. Fifteen skilled tennis players performed volley strokes under five (right, rightmiddle, middle, left-middle, left) different lateral contact locations. A ball machine was modified so subjects could not predict the ball trajectory before it was released from the machine. Two high-speed cameras (250Hz) were genlocked to collect the data and the Kwon3D software was used to analyze the temporal and kinematic variables. The results indicated the middle location have the shortest pushing (0.249s) and stroke (0.466s) time than other locations. An ipsilateral side step occurred more often in Backhand (BH, 86%) than in Forehand (FH, 67%). In addition, more FH volley (55%) was used than BH (45%) when return the ball from middle location

    The adhesion G protein-coupled receptor GPR56/ADGRG1 is an inhibitory receptor on human NK cells

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    Natural killer (NK) cells possess potent cytotoxic mechanisms that need to be tightly controlled. We here explored the regulation and function of GPR56/ADGRG1, an adhesion G protein-coupled receptor implicated in developmental processes and expressed distinctively in mature NK cells. Expression of GPR56 was triggered by Hobit, a homolog of Blimp-1, and declined upon cell activation. Through studying NK cells from polymicrogyria patients with disease-causing mutations in the ADGRG1 gene, encoding GPR56, and NK-92 cells ectopically expressing the receptor, we found that GPR56 negatively regulates immediate effector functions, including production of inflammatory cytokines and cytolytic proteins, degranulation, and target cell killing. GPR56 pursues this activity by associating with the tetraspanin CD81. We conclude that GPR56 inhibits natural cytotoxicity of human NK cells

    An Overview of Regional Experiments on Biomass Burning Aerosols and Related Pollutants in Southeast Asia: From BASE-ASIA and the Dongsha Experiment to 7-SEAS

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    By modulating the Earth-atmosphere energy, hydrological and biogeochemical cycles, and affecting regional-to-global weather and climate, biomass burning is recognized as one of the major factors affecting the global carbon cycle. However, few comprehensive and wide-ranging experiments have been conducted to characterize biomass-burning pollutants in Southeast Asia (SEA) or assess their regional impact on meteorology, the hydrological cycle, the radiative budget, or climate change. Recently, BASEASIA (Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment) and the 7-SEAS (7- South-East Asian Studies) Dongsha Experiment were conducted during the spring seasons of 2006 and 2010 in northern SEA, respectively, to characterize the chemical, physical, and radiative properties of biomass-burning emissions near the source regions, and assess their effects. This paper provides an overview of results from these two campaigns and related studies collected in this special issue, entitled Observation, modeling and impact studies of biomass burning and pollution in the SE Asian Environment. This volume includes 28 papers, which provide a synopsis of the experiments, regional weatherclimate, chemical characterization of biomass-burning aerosols and related pollutants in source and sink regions, the spatial distribution of air toxics (atmospheric mercury and dioxins) in source and remote areas, a characterization of aerosol physical, optical, and radiative properties, as well as modeling and impact studies. These studies, taken together, provide the first relatively complete dataset of aerosol chemistry and physical observations conducted in the sourcesink region in the northern SEA, with particular emphasis on the marine boundary layer and lower free troposphere (LFT). The data, analysis and modeling included in these papers advance our present knowledge of source characterization of biomass-burning pollutants near the source regions as well as the physical and chemical processes along transport pathways. In addition, we raise key questions to be addressed by a coming deployment during springtime 2013 in northern SEA, named 7-SEASBASELInE (Biomass-burning Aerosols Stratocumulus Environment: Lifecycles and Interactions Experiment). This campaign will include a synergistic approach for further exploring many key atmospheric processes (e.g., complex aerosol-cloud interactions) and impacts of biomass burning on the surface-atmosphere energy budgets during the lifecycles of biomass burning emissions

    Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

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    © 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

    GPS autoproteolysis is required for CD97 to up-regulate the expression of N-cadherin that promotes homotypic cell-cell aggregation

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    Most adhesion-class G protein-coupled receptors (adhesion-GPCRs) undergo a novel self-catalytic cleavage at the GPCR proteolysis site (GPS) to form a hetero-dimeric complex containing the extracellular and seven-span transmembrane subunits. However, little is known about the role of GPS auto-proteolysis in the function of adhesion-GPCRs. Here we show that GPS cleavage is essential for the homotypic cell aggregation promoted by CD97 receptor, a leukocyte-restricted adhesion-GPCR often aberrantly expressed in carcinomas. We find that CD97 does not mediate cell aggregation directly. Instead, expression of the wild type - but not the GPS cleavage-deficient CD97 up-regulates the expression of N-cadherin, leading to Ca++-dependent cell-cell aggregation. Our results provide a clear evidence for the role of GPS proteolytic modification in the cellular function of adhesion-GPCRs
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