Tethered Swimming
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Determinação da coordenação de nado por meio da análise cinética e cinemática no estilo crawl
A coordenação espaço-temporal dos movimentos dos braços de nadadores competitivos tem demonstrado ser um importante fator ligado a velocidade de nado e ao desempenho desses atletas. Os modelos básicos de coordenação comumente percebidos são: (1) captura - caracterizado pela existência de períodos sem propulsão entre a execução de cada braçada;
Publicado em: 2009
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2. A relevancia do treinamento complexo no desempenho de nadadores competitivos / The relevance of complex training on competitive swimming performance
The aim of this study was to verify the effect of Complex Training (CT) in swimming performance. Fourteen state competitive swimmers were assigned in two groups: control (CG I n=6) and experimental (EG I n=8). Both groups performed the same training in water during six weeks, five days I week. Additionally, EG performed a high specific strength training call
Publicado em: 2006
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3. Rhizobium meliloti swims by unidirectional, intermittent rotation of right-handed flagellar helices.
The 5 to 10 peritrichously inserted complex flagella of Rhizobium meliloti MVII-1 were found to form right-handed flagellar bundles. Bacteria swam at speeds up to 60 microns/s, their random three-dimensional walk consisting of straight runs and quick directional changes (turns) without the vigorous angular motion (tumbling) seen in swimming Escherichia coli
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4. Effect of Intracellular pH on Rotational Speed of Bacterial Flagellar Motors†
Weak acids such as acetate and benzoate, which partially collapse the transmembrane proton gradient, not only mediate pH taxis but also impair the motility of Escherichia coli and Salmonella at an external pH of 5.5. In this study, we examined in more detail the effect of weak acids on motility at various external pH values. A change of external pH over the
American Society for Microbiology.
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5. Motility, chemokinesis, and methylation-independent chemotaxis in Azospirillum brasilense.
Observations of free-swimming and antibody-tethered Azospirillum brasilense cells showed that their polar flagella could rotate in both clockwise and counterclockwise directions. Rotation in a counterclockwise direction caused forward movement of free-swimming cells, whereas the occasional change in the direction of rotation to clockwise caused a brief rever
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6. Unidirectional, intermittent rotation of the flagellum of Rhodobacter sphaeroides.
The single flagellum of the photosynthetic bacterium Rhodobacter sphaeroides was found to be medially located on the cell body. Observation of free-swimming bacteria, and bacteria tethered by their flagellar filaments, revealed that the flagellum could only rotate in the clockwise direction; switching of the direction of rotation was never observed. Flagella
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7. Correlation between bacteriophage chi adsorption and mode of flagellar rotation of Escherichia coli chemotaxis mutants.
We studied the adsorption of phage chi to various behavioral mutants (che mutants) of Escherichia coli having different swimming modes. Bacteriophage chi infects only bacteria with active flagella, and it was therefore of interest to examine whether the mode of swimming has an effect on the susceptibility of the bacteria to the phage. Neither the mode of swi
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8. Motility response of Rhodobacter sphaeroides to chemotactic stimulation.
Tethered rotating cells of Rhodobacter sphaeroides varied widely in their stopping frequency; 45% of cells showed no stops of longer than 1 s, whereas others showed stops of up to several seconds. Individual cells alternated between stops and rotation at a fairly constant rate, without continuous variation. Addition of the chemoattractant propionate to free-
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9. Roles of Chemosensory Pathways in Transient Changes in Swimming Speed of Rhodobacter sphaeroides Induced by Changes in Photosynthetic Electron Transport
The response of free-swimming Rhodobacter sphaeroides to increases and decreases in the intensity of light of different wavelengths was analyzed. There was a transient (1 to 2 s) increase in swimming speed in response to an increase in light intensity, and there was a similar transient stop when the light intensity decreased. Measurement of changes in membra
American Society for Microbiology.
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10. Sensory adaptation and deadaptation by Bacillus subtilis.
Cells of Bacillus subtilis, when tethered by using antiflagellar antibody, rotate briefly counterclockwise (swimming behavior) or clockwise (tumbling behavior) when amino acids are added or removed, respectively. "Dissociation constants" for attractant-binding site interactions, calculated from duration of the rotational response to addition of amino acids,
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11. Mutant MotB proteins in Escherichia coli.
The MotB protein of Escherichia coli is an essential component in each of eight torque generators in the flagellar rotary motor. Based on its membrane topology, it has been suggested that MotB might be a linker that fastens the torque-generating machinery to the cell wall. Here, we report the isolation and characterization of a number of motB mutants. As fou
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12. Pausing of flagellar rotation is a component of bacterial motility and chemotaxis.
When bacterial cells are tethered to glass by their flagella, many of them spin. On the basis of experiments with tethered cells it has generally been thought that the motor which drives the flagellum is a two-state device, existing in either a counterclockwise or a clockwise state. Here we show that a third state of the motor is that of pausing, the duratio