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Sample records for sustainable swimming speed

  1. Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi).

    Science.gov (United States)

    Palstra, Arjan P; Mes, Daan; Kusters, Kasper; Roques, Jonathan A C; Flik, Gert; Kloet, Kees; Blonk, Robbert J W

    2014-01-01

    Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (U opt in m s(-1) or body lengths s(-1), BL s(-1)) were assessed and then applied to determine the effects of long-term forced and sustained swimming at U opt on growth performance of juvenile yellowtail kingfish. U opt was quantified in Blazka-type swim-tunnels for 145, 206, and 311 mm juveniles resulting in values of: (1) 0.70 m s(-1) or 4.83 BL s(-1), (2) 0.82 m s(-1) or 3.25 BL s(-1), and (3) 0.85 m s(-1) or 2.73 BL s(-1). Combined with literature data from larger fish, a relation of U opt (BL s(-1)) = 234.07(BL)(-0.779) (R (2) = 0.9909) was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s(-1) ("swimmers") or allowed to perform spontaneous activity at low water flow ("resters") in a newly designed 3600 L oval flume (with flow created by an impeller driven by an electric motor), were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n = 23) showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n = 23). As both groups were fed equal rations, feed conversion ratio (FCR) for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31%) in the ventral aorta of swimmers vs. resters (44 ± 3 vs. 34 ± 3 mL min(-1), respectively, under anesthesia). Thus, growth performance can be rapidly improved by optimal swimming, without larger feed investments.

  2. Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi

    Directory of Open Access Journals (Sweden)

    Arjan P. Palstra

    2015-01-01

    Full Text Available Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (Uopt in m s-1 or body lengths s-1, BL s-1 were assessed and then applied to determine the effects of long-term forced and sustained swimming at Uopt on growth performance of juvenile yellowtail kingfish. Uopt was quantified in Blazka-type swim-tunnels for 145 mm, 206 mm and 311 mm juveniles resulting in values of: 1 0.70 m s-1 or 4.83 BL s-1, 2 0.82 m s-1 or 3.25 BL s-1 and 3 0.85 m s-1 or 2.73 BL s-1. Combined with literature data from larger fish, a relation of Uopt (BL s-1 = 234.07(BL-0.779 (R2= 0.9909 was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s-1 (‘swimmers’ or allowed to perform spontaneous activity at low water flow (‘resters’ in a newly designed 3,600 L oval flume (with flow created by an impeller driven by an electric motor, were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n= 23 showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n= 23. As both groups were fed equal rations, feed conversion ratio (FCR for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31% in the ventral aorta of swimmers vs. resters (44 ± 3 mL min-1 vs. 34 ± 3 mL min-1, respectively, under anesthesia. Thus growth performance can be rapidly improved by optimal swimming, without larger feed investments.

  3. Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi)

    NARCIS (Netherlands)

    Palstra, A.P.; Mes, D.; Kusters, K.; Roques, J.A.C.; Flik, G.; Kloet, K.; Blonk, R.J.W.

    2015-01-01

    Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (U-opt in m s(-1) or body lengths s(-1), BL s(-1)) were assessed and then applied to determine the effects of long-term forced and

  4. Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

    DEFF Research Database (Denmark)

    Farrell, A P; Steffensen, J F

    1987-01-01

    a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance.......The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...

  5. Intraspecific variation in aerobic and anaerobic locomotion: gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata) do not exhibit a trade-off between maximum sustained swimming speed and minimum cost of transport.

    Science.gov (United States)

    Svendsen, Jon C; Tirsgaard, Bjørn; Cordero, Gerardo A; Steffensen, John F

    2015-01-01

    Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; U crit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3) there is a trade-off between maximum sustained swimming speed (U sus) and minimum cost of transport (COTmin); and (4) variation in U sus correlates positively with optimum swimming speed (U opt; i.e., the speed that minimizes energy expenditure per unit of distance traveled). Data collection involved swimming respirometry and video analysis. Results showed that anaerobic swimming costs (i.e., EPOC) increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg(-1). Data are consistent with a previous study on striped surfperch (Embiotoca lateralis), a labriform swimmer, suggesting that the metabolic cost of burst swimming is similar across various types of locomotion. There was no correlation between U crit and MS or anaerobic capacity in S. aurata indicating that other factors, including morphological or biomechanical traits, influenced U crit. We found no evidence of a trade-off between U sus and COTmin. In fact, data revealed significant negative correlations between U sus and COTmin, suggesting that individuals with high U sus also exhibit low COTmin. Finally, there were positive correlations between U sus and U opt. Our study demonstrates the energetic importance of anaerobic metabolism during unsteady swimming, and provides intraspecific evidence that superior maximum sustained swimming speed is associated with superior swimming

  6. Intraspecific variation in aerobic and anaerobic locomotion: gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata) do not exhibit a trade-off between maximum sustained swimming speed and minimum cost of transport

    Science.gov (United States)

    Svendsen, Jon C.; Tirsgaard, Bjørn; Cordero, Gerardo A.; Steffensen, John F.

    2015-01-01

    Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; Ucrit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3) there is a trade-off between maximum sustained swimming speed (Usus) and minimum cost of transport (COTmin); and (4) variation in Usus correlates positively with optimum swimming speed (Uopt; i.e., the speed that minimizes energy expenditure per unit of distance traveled). Data collection involved swimming respirometry and video analysis. Results showed that anaerobic swimming costs (i.e., EPOC) increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg−1. Data are consistent with a previous study on striped surfperch (Embiotoca lateralis), a labriform swimmer, suggesting that the metabolic cost of burst swimming is similar across various types of locomotion. There was no correlation between Ucrit and MS or anaerobic capacity in S. aurata indicating that other factors, including morphological or biomechanical traits, influenced Ucrit. We found no evidence of a trade-off between Usus and COTmin. In fact, data revealed significant negative correlations between Usus and COTmin, suggesting that individuals with high Usus also exhibit low COTmin. Finally, there were positive correlations between Usus and Uopt. Our study demonstrates the energetic importance of anaerobic metabolism during unsteady swimming, and provides intraspecific evidence that superior maximum sustained swimming speed is associated with superior swimming economy and

  7. Intraspecific variation in aerobic and anaerobic locomotion: gilthead sea bream (Sparus aurata and Trinidadian guppy (Poecilia reticulata do not exhibit a trade-off between maximum sustained swimming speed and minimum cost of transport.

    Directory of Open Access Journals (Sweden)

    Jon Christian Svendsen

    2015-02-01

    Full Text Available Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata and Trinidadian guppy (Poecilia reticulata, both axial swimmers, this study tested four hypotheses: 1 gait transition from steady to unsteady (i.e. burst-assisted swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC; 2 variation in swimming performance (critical swimming speed; Ucrit correlates with metabolic scope (MS or anaerobic capacity (i.e. maximum EPOC; 3 there is a trade-off between maximum sustained swimming speed (Usus and minimum cost of transport (COTmin; and 4 variation in Usus correlates positively with optimum swimming speed (Uopt; i.e. the speed that minimizes energy expenditure per unit of distance travelled. Data collection involved swimming respirometry and video analysis. Results showed that anaerobic swimming costs (i.e. EPOC increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg-1. Data are consistent with a previous study on striped surfperch (Embiotoca lateralis, a labriform swimmer, suggesting that the metabolic cost of burst swimming is similar across various types of locomotion. There was no correlation between Ucrit and MS or anaerobic capacity in S. aurata indicating that other factors, including morphological or biomechanical traits, influenced Ucrit. We found no evidence of a trade-off between Usus and COTmin. In fact, data revealed significant negative correlations between Usus and COTmin, suggesting that individuals with high Usus also exhibit low COTmin. Finally, there were positive correlations between Usus and Uopt. Our study demonstrates the energetic importance of anaerobic metabolism during unsteady swimming, and provides intraspecific evidence that superior maximum sustained swimming speed is associated with superior swimming economy and optimum

  8. Ion-swimming speed variation of Vibrio cholerae cells

    Indian Academy of Sciences (India)

    In the present work we report the variation in swimming speed of Vibrio cholerae with respect to the change in concentration of sodium ions in the medium. We have also studied the variation in swimming speed with respect to temperature. We find that the swimming speed initially shows a linear increase with the increase of ...

  9. Kinematics and critical swimming speed of juvenile scalloped hammerhead sharks

    Science.gov (United States)

    Lowe

    1996-01-01

    Kinematics and critical swimming speed (Ucrit) of juvenile scalloped hammerhead sharks Sphyrna lewini were measured in a Brett-type flume (635 l). Kinematic parameters were also measured in sharks swimming in a large pond for comparison with those of sharks swimming in the flume. Sharks in the flume exhibited a mean Ucrit of 65±11 cm s-1 (± s.d.) or 1.17±0.21 body lengths per second (L s-1), which are similar to values for other species of sharks. In both the flume and pond, tailbeat frequency (TBF) and stride length (LS) increased linearly with increases in relative swimming speed (Urel=body lengths traveled per second). In the flume, tailbeat amplitude (TBA) decreased with increasing speed whereas TBA did not change with speed in the pond. Differences in TBF and LS between sharks swimming in the flume and the pond decreased with increases in Urel. Sharks swimming at slow speeds (e.g. 0.55 L s-1) in the pond had LS 19 % longer and TBF 21 % lower than sharks in the flume at the same Urel. This implies that sharks in the flume expended more energy while swimming at comparable velocities. Comparative measurements of swimming kinematics from sharks in the pond can be used to correct for effects of the flume on shark swimming kinematics and energetics.

  10. The Effect of Concurrent Visual Feedback on Controlling Swimming Speed

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    Szczepan Stefan

    2016-03-01

    Full Text Available Introduction. Developing the ability to control the speed of swimming is an important part of swimming training. Maintaining a defined constant speed makes it possible for the athlete to swim economically at a low physiological cost. The aim of this study was to determine the effect of concurrent visual feedback transmitted by the Leader device on the control of swimming speed in a single exercise test. Material and methods. The study involved a group of expert swimmers (n = 20. Prior to the experiment, the race time for the 100 m distance was determined for each of the participants. In the experiment, the participants swam the distance of 100 m without feedback and with visual feedback. In both variants, the task of the participants was to swim the test distance in a time as close as possible to the time designated prior to the experiment. In the first version of the experiment (without feedback, the participants swam the test distance without receiving real-time feedback on their swimming speed. In the second version (with visual feedback, the participants followed a beam of light moving across the bottom of the swimming pool, generated by the Leader device. Results. During swimming with visual feedback, the 100 m race time was significantly closer to the time designated. The difference between the pre-determined time and the time obtained was significantly statistically lower during swimming with visual feedback (p = 0.00002. Conclusions. Concurrently transmitting visual feedback to athletes improves their control of swimming speed. The Leader device has proven useful in controlling swimming speed.

  11. EFFECTS OF THREE FEEDBACK CONDITIONS ON AEROBIC SWIM SPEEDS

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    Pedro Pérez Soriano

    2009-03-01

    Full Text Available The purpose of this study was twofold: (a to develop an underwater chronometer capable to provide feedback while the athlete is swimming, as well as being a control tool for the coach, and (b to analyse its feedback effect on swim pace control compared with feedback provided by the coach and with no feedback, in 25 m and 50 m swimming pools. 30 male swimmers of national level volunteer to participate. Each swimmer swam 3 x 200 m at aerobic speed (AS and 3 x 200 m just under the anaerobic threshold speed (AnS, each swam repetition with a different feedback condition: chronometer, coach and without feedback. Results (a validate the chronometer system developed and (b show that swimmers pace control is affected by the type of feedback provided, the swim speed elected and the size of the swimming pool

  12. Costs of swimming measured at optimum speed: scale effects, differences between swimming styles, taxonomic groups and submerged and surface swimming.

    Science.gov (United States)

    Videler, J J; Nolet, B A

    1990-01-01

    1. Data on swimming energy expenditure of 30 submerged and nine surface swimmers, covering different swimming styles and taxonomic groups, are selected from the literature. 2. The costs of transport at the optimum speed are compared and related to body mass and Re numbers. 3. Fish and turtles use relatively less and most surface swimmers slightly more energy than the other submerged swimmers; man and mink are poorly adapted to swimming. 4. The metabolic rate in W at optimum speed is approximately equal to the body mass in kg for fish and turtles and three times the mass figure for the other submerged swimmers.

  13. The influence of temperature on muscle velocity and sustained performance in swimming carp.

    Science.gov (United States)

    Rome, L C; Funke, R P; Alexander, R M

    1990-11-01

    The aim of this study was to evaluate how fish locomote at different muscle temperatures. Sarcomere length excursion and muscle shortening velocity, V, were determined from high-speed motion pictures of carp, Cyprinus carpio (11-14 cm), swimming steadily at various sustained speeds at 10, 15 and 20 degrees C. In the middle and posterior regions of the carp, sarcomeres of the lateral red muscle underwent cyclical excursions of 0.31 microns, centered around the resting length of 2.06 microns (i.e. from 1.91 to 2.22 microns). The amplitudes of the sarcomere length excursions were essentially independent of swimming speed and temperature. As tail-beat frequency increased linearly with swimming speed regardless of temperature, the sarcomeres underwent the same length changes in a shorter time. Thus, V increased in a linear and temperature-independent manner with swimming speed. Neither temperature nor swimming speed had an influence on tail-beat amplitude or tail height. Our findings indicate that muscle fibres are used only over a narrow, temperature-independent range of V/Vmax (0.17-0.36) where power and efficiency are maximal. Carp start to recruit their white muscles at swimming speeds where the red muscle V/Vmax becomes too high (and thus power output declines). When the V/Vmax of the active muscle falls too low during steady swimming, carp switch to 'burst-and-coast' swimming, apparently to keep V/Vmax high. Because Vmax (maximum velocity of shortening) of carp red muscle has a Q10 of 1.63, the transition speeds between swimming styles are lower at lower temperatures. Thus, carp recruit their white anaerobic muscle at a lower swimming speed at lower temperatures (verified by electromyography), resulting in a lower maximum sustainable swimming speed. The present findings also indicate that, to generate the same total force and power to swim at a given speed, carp at 10 degrees C must recruit about 50% greater fibre cross-sectional area than they do at 20 degrees C.

  14. Swimming Speeds of Filaments in Viscous Fluids with Resistance

    Science.gov (United States)

    Ho, Nguyenho; Olson, Sarah

    2015-11-01

    Spermatozoa and bacteria can utilize lateral and spiral bending waves to propagate in a fluid. Often, they encounter different fluid environments filled with mucus, cells, hormones, and other large proteins. These extra materials act as friction, possibly preventing or enhancing forward progression of swimmers. To understand these effects, we employ Taylor's techniques to calculate the asymptotic swimming speeds of a cylinder of infinite extent in a viscous fluid with resistance known as a Brinkman fluid. We find that, up to the second order expansion, the swimming speeds are enhanced as resistance increases. The Stokes limit can also be also recovered from this result as resistance goes to zero. In addition, we show numerical results for a Lagrangian algorithm of a rod waving in a porous medium and compare numerical results to asymptotic swimming speeds.

  15. On the development of inexpensive speed and position tracking system for swimming

    DEFF Research Database (Denmark)

    Trangbæk, Søren; Rasmussen, Cuno; Andersen, Thomas Bull

    2016-01-01

    A semi-automated tracking system was developed for the analysis of swimming, using cameras, an LED diode marker, and a red swim cap. Four experienced young swimmers were equipped with a marker and a swim cap and their position and speed was tracked throughout above-water and under-water swimming...

  16. Body Fineness Ratio as a Predictor of Maximum Prolonged-Swimming Speed in Coral Reef Fishes

    Science.gov (United States)

    Walker, Jeffrey A.; Alfaro, Michael E.; Noble, Mae M.; Fulton, Christopher J.

    2013-01-01

    The ability to sustain high swimming speeds is believed to be an important factor affecting resource acquisition in fishes. While we have gained insights into how fin morphology and motion influences swimming performance in coral reef fishes, the role of other traits, such as body shape, remains poorly understood. We explore the ability of two mechanistic models of the causal relationship between body fineness ratio and endurance swimming-performance to predict maximum prolonged-swimming speed (Umax) among 84 fish species from the Great Barrier Reef, Australia. A drag model, based on semi-empirical data on the drag of rigid, submerged bodies of revolution, was applied to species that employ pectoral-fin propulsion with a rigid body at Umax. An alternative model, based on the results of computer simulations of optimal shape in self-propelled undulating bodies, was applied to the species that swim by body-caudal-fin propulsion at Umax. For pectoral-fin swimmers, Umax increased with fineness, and the rate of increase decreased with fineness, as predicted by the drag model. While the mechanistic and statistical models of the relationship between fineness and Umax were very similar, the mechanistic (and statistical) model explained only a small fraction of the variance in Umax. For body-caudal-fin swimmers, we found a non-linear relationship between fineness and Umax, which was largely negative over most of the range of fineness. This pattern fails to support either predictions from the computational models or standard functional interpretations of body shape variation in fishes. Our results suggest that the widespread hypothesis that a more optimal fineness increases endurance-swimming performance via reduced drag should be limited to fishes that swim with rigid bodies. PMID:24204575

  17. PACING DEVICE FOR SWIMMING. MECHANICAL CONSTRUCTION OF CONSTANT SPEED

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    MESSINIS S.

    2010-04-01

    Full Text Available The pace in swimming is very important because it allows swimmers to allocate their forces accordingly, and therefore a distance to travel as quickly as possible. The training pace at different swimmingspeeds and combinations thereof, is an important part of training before the competitions.The definition and maintenance of the stable and swimmer specific speed is difficult to achieve and requires considerable effort and experience. To determine the desired rate of accuracy by the researchers and their coaches used till now, various audio and visual media.However, some of these institutions did not very accurately measure the rate and not all styles of swimming, while other aspects affect the proper swimming. In this construction, a key objective is to solve the problems occurring in the previous constructions, the modern technological development of them and the adaption of the specificities of different swimming styles.This device consists of an electro 3 / 8 of the horse, a flange, a single inverter from 3 / 8 to ½ of the horse, pulleys with taper Bush, flange axle, pulleys, platforms and a 52 meters cable. The assembly and operation is as follows: At the edge of the pool next to the platform is placed the base of pulleys, the electro setis connected to the inverter and the axle flange.Precisely opposite is positioned the other base. Along the pool «moves» the cable that connects the two bases, located 150 cm above the water. A fixed point on the cable is marked with paint in order to be visible to the swimmer during backstroke swimming while for other styles we adapt a lamination at the cable vertically inthe pool, above the surface a sheet of 15 cm which is painted with strong color that is visible from the athlete and will precede him. Setting the speed with inverter it starts from one end of the tank leading to the other, doing a circular motion.The swimmer is required to follow the marked point of the cable in the backstroke or

  18. Mechanisms of temperature-dependent swimming: the importance of physics, physiology and body size in determining protist swimming speed.

    Science.gov (United States)

    Beveridge, Oliver S; Petchey, Owen L; Humphries, Stuart

    2010-12-15

    Body temperatures and thus physiological rates of poikilothermic organisms are determined by environmental temperature. The power an organism has available for swimming is largely dependent on physiological rates and thus body temperature. However, retarding forces such as drag are contingent on the temperature-dependent physical properties of water and on an organism's size. Consequently, the swimming ability of poikilotherms is highly temperature dependent. The importance of the temperature-dependent physical properties of water (e.g. viscosity) in determining swimming speed is poorly understood. Here we propose a semi-mechanistic model to describe how biological rates, size and the physics of the environment contribute to the temperature dependency of microbial swimming speed. Data on the swimming speed and size of a predatory protist and its protist prey were collected and used to test our model. Data were collected by manipulating both the temperature and the viscosity (independently of temperature) of the organism's environment. Protists were either cultured in their test environment (for several generations) or rapidly exposed to their test environment to assess their ability to adapt or acclimate to treatments. Both biological rates and the physics of the environment were predicted to and observed to contribute to the swimming speed of protists. Body size was not temperature dependent, and protists expressed some ability to acclimate to changes in either temperature or viscosity. Overall, using our parameter estimates and novel model, we are able to suggest that 30 to 40% (depending on species) of the response in swimming speed associated with a reduction in temperature from 20 to 5°C is due to viscosity. Because encounter rates between protist predators and their prey are determined by swimming speed, temperature- and viscosity-dependent swimming speeds are likely to result in temperature- and viscosity-dependent trophic interactions.

  19. Hydroacoustic measurement of swimming speed of North Sea saithe in the field

    DEFF Research Database (Denmark)

    Pedersen, Jan

    2001-01-01

    . the uncertainty or target location increased with depth and resulted in calculated average swimming speeds of 0.15 m s(-1) even for a stationary target. With increasing swimming speed the average error decreased to Om s ' for speeds >0.34 m s(-1). Species identity was verified by trawling in a pelagic layer...

  20. Swimming speed alteration in the early developmental stages of Paracentrotus lividus sea urchin as ecotoxicological endpoint.

    Science.gov (United States)

    Morgana, Silvia; Gambardella, Chiara; Falugi, Carla; Pronzato, Roberto; Garaventa, Francesca; Faimali, Marco

    2016-04-01

    Behavioral endpoints have been used for decades to assess chemical impacts at concentrations unlikely to cause mortality. With recently developed techniques, it is possible to investigate the swimming behavior of several organisms under laboratory conditions. The aims of this study were: i) assessing for the first time the feasibility of swimming speed analysis of the early developmental stage sea urchin Paracentrotus lividus by an automatic recording system ii) investigating any Swimming Speed Alteration (SSA) on P. lividus early stages exposed to a chemical reference; iii) identifying the most suitable stage for SSA test. Results show that the swimming speed of all the developmental stages was easily recorded. The swimming speed was inhibited as a function of toxicant concentration. Pluteus were the most appropriate stage for evaluating SSA in P. lividus as ecotoxicological endpoint. Finally, swimming of sea urchin early stages represents a sensitive endpoint to be considered in ecotoxicological investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Evolution of Gamete Motility Differences I. Relation Between Swimming Speed and Pheromonal Attraction

    NARCIS (Netherlands)

    Hoekstra, Rolf F.; Janz, Robert F.; Schilstra, A.J.

    1984-01-01

    An analysis is made using population genetic models of the evolution of gamete motility differences as a consequence of a pheromonal gametic approach mechanism. A stable swimming speed dimorphism may arise via disruptive selection on swimming speed, resulting from selection favouring a high

  2. Swim Speed Tests as a Method for Differentiating the Profiles of Young Swimmers

    Directory of Open Access Journals (Sweden)

    Klara Šiljeg

    2017-09-01

    Full Text Available Swimming tests are used in every training cycle and seasons with purpose of estimating swimming performance and evaluate certain training types. The focus of this study is an attempt to distinguish between the potential short-distance and longer-distance swimmers, as well as the swimmers who could have desirable profiles for particular swimming styles. For this purpose, several aims are given: ( to determine the latent dimensions of the performances in swimming tests, conducted on various distances and performed using different swimming styles; 2 to determine the correlations between speeds on various distances using different swimming styles; 3 to determine the differences in various distance speeds at the same swimmers ; 4 to determine the profiles of swimmers, based on the various distance speeds (4. Male swimmers (N=68, aged 14 to 16 from five Zagreb clubs were tested. Four swimming tests were used to measure speed (25-m freestyle, backstroke, breaststroke, butterfly, five swimming tests measured speed endurance (50-m freestyle, 100-m freestyle, backstroke, breaststroke, butterfly, while only one test measured endurance (800-m freestyle. The results revealed two interpretable and highly reliable latent dimensions of swimming tests. Factor analysis of the scores in swimming tests differentiated the variables of swimming tests that describe breaststrokes and other strokes. Most of the scores in the swimming tests are positively correlated (in range 0.25–0.85, while no differences in various distance speeds among the same swimmers are found. The results indicate the importance of using swimming tests, especially in breaststrokes styles, because of their specific motor structure.

  3. Fluid-mediated stability and speed-increase for heaving hydrofoils swimming side-by-side

    Science.gov (United States)

    Newbolt, Joel; Zhang, Jun; Ristroph, Leif

    2017-11-01

    As an example of collective motion in active swimmers we study the fluid-mediated interaction between two heaving hydrofoils that swim with a fixed transverse separation (between the heaving mid-heights) but are free to independently choose their forward swimming speeds and positions. Experiments reveal that out-of-phase foils are attracted to a side-by-side configuration which also increases the swimming speed of the pair (up to 59% faster for our parameters), while in-phase foils are repelled from this configuration. Because this type of swimming is qualitatively similar to that of fish and birds this interaction could be important to schooling and flocking.

  4. Swimming Speed of Larval Snail Does Not Correlate with Size and Ciliary Beat Frequency

    Science.gov (United States)

    Chan, Kit Yu Karen; Jiang, Houshuo; Padilla, Dianna K.

    2013-01-01

    Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8–4 body lengths s−1) that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton. PMID:24367554

  5. Optimization of sustaining swimming speed of matrinxã Brycon amazonicus: performance and adaptive aspects Otimização da velocidade de nado sustentado em matrinxã Brycon amazonicus: rendimento e aspectos adaptativos

    Directory of Open Access Journals (Sweden)

    Gustavo Arbeláez-Rojas

    2010-01-01

    Full Text Available Deleterious changes in metabolism, growth performance and body composition may be observed if fish are constrained to swimming continuously or intermittently at over-speeds. This study evaluates effects of four water speeds on growth, body composition and hematologic profile of juvenile matrinxã, Brycon amazonicus. Fish (33.3 ± 0.9 g and 13.44 ± 0.1 cm were held for 90 days in five water speeds (0.0 - control, 1.0, 1.5, 2.0 and 2.5 body lengths per second - BLAt swimming speeds ranging on 1.0 and 1.5 BL s–1, in fish growth was 20% higher. Hemoglobin and red blood cells at 1.5 BL s–1 increased 24% and 18% respectively; hematocrit was 17% higher in all exercised fish; protein content of white muscle at 1.0 BL s–1 was 2% higher; lipid deposition in red muscle at 1.0 BL s–1 was 22% higher and water retention 3% lower. Crude energy levels enhanced 10% in all exercised fish; liver water retention was 6% lower at 1.0 BL s–1; liver lipid composition was 29% higher than control and 34% higher than 1.5 BL s–1; liver crude energy increased at 1.0 BL s–1 as compared with control and 2.5 BL s–1. Lipid deposition in ventral muscle was 9% higher at 2.0 BL s–1. Although high lipid deposition of matrinxã has been achieved in moderate swimming speeds, lipids may be the main fuel source to maintain the metabolic demands of exercised matrinxã. The best water flow speed for optimized growth of matrinxã ranged on 1.0 and 1.5 BL s–1.Modificações deletérias no metabolismo, rendimento de crescimento e composição corporal podem ser observadas em peixes forçados à natação contínua ou intermitente sob velocidades excessivas. Neste trabalho, os efeitos de quatro velocidades de água no crescimento, composição corporal e perfil hematológico foram avaliados em matrinxãs juvenis, Brycon amazonicus. Os peixes (33,3 ± 0,9 g e 13,44 ± 0,1 cm foram mantidos durante 90 dias em cinco velocidades de água (0,0 – controle; 1,0; 1,5; 2,0 e 2

  6. Swimming Speeds of Waving Cylindrical Tails in Viscous Fluids with Resistance

    CERN Document Server

    Ho, Nguyenho

    2015-01-01

    The mathematical analysis of swimming speeds for microorganisms in a 3D fluid is investigated by studying a cylinder propagating lateral or spiral waves of displacement at zero Reynolds number. Since many microorganisms swim in a highly heterogeneous environment with obstacles to swimming, we study swimming speeds of an infinite cylinder in a fluid governed by the Brinkman equation. This represents the effective flow due to a sparse, stationary network of obstructions (e.g. fibers or polymers) in a Newtonian fluid. For a fixed propagating wave of bending, we find that swimming speeds are enhanced due to the resistance from the obstructions. Additionally, we examine the work done per unit area on the surface of a cylindrical filament and recover the limit for the Stokes case as the resistance goes to zero.

  7. Experiment of Critical Swimming Speed of Fingerling Masu Salmon (Oncorhynchus masou masou) Using River Water

    Science.gov (United States)

    Izumi, Mattashi; Kato, Koh

    The authors conducted a field swimming experiment using cultured masu salmon (Oncorhynchus masou masou) fingerlings in order to study their critical swimming speed during their release into the river in the Iwaki River diversion weir. The experimental equipment was a small, rectangular cross-section channel, which was installed in a local riverbed at the fishway. The experiment was conducted using an average cross-sectional water flow velocity of 17 to 92 cm·s-1, and using masu salmon fingerlings from 4.8 to 7.1 cm in the length. River water temperature was between 13.7 and 20.6 °C. The critical swimming speed measured over 60 minutes was between 16 and 41 cm·s-1 and a positive correlation was found between the critical swimming speed and body length. The critical swimming speed measured by body length (BL) was 3.5 to 6.9 times (that is, the distance travelled per second based on body length), and the mean critical swimming speed was 5.5 (with a standard deviation of 1.1). Results showed that water temperature differences in the experiment had no significant effect on the critical swimming speed measured over 60 minutes.

  8. How body torque and Strouhal number change with swimming speed and developmental stage in larval zebrafish

    NARCIS (Netherlands)

    Leeuwen, van J.L.; Voesenek, C.J.; Müller, U.K.

    2015-01-01

    Small undulatory swimmers such as larval zebrafish experience both inertial and viscous forces, the relative importance of which is indicated by the Reynolds number (Re). Re is proportional to swimming speed (vswim) and body length; faster swimming reduces the relative effect of viscous forces.

  9. Optimal swimming speed in head currents and effects on distance movement of winter-migrating fish.

    Directory of Open Access Journals (Sweden)

    Jakob Brodersen

    Full Text Available Migration is a commonly described phenomenon in nature that is often caused by spatial and temporal differences in habitat quality. However, as migration requires energy, the timing of migration may depend not only on differences in habitat quality, but also on temporal variation in migration costs. Such variation can, for instance, arise from changes in wind or current velocity for migrating birds and fish, respectively. Whereas behavioural responses of birds to such changing environmental conditions have been relatively well described, this is not the case for fish, although fish migrations are both ecologically and economically important. We here use passive and active telemetry to study how winter migrating roach regulate swimming speed and distance travelled per day in response to variations in head current velocity. Furthermore, we provide theoretical predictions on optimal swimming speeds in head currents and relate these to our empirical results. We show that fish migrate farther on days with low current velocity, but travel at a greater ground speed on days with high current velocity. The latter result agrees with our predictions on optimal swimming speed in head currents, but disagrees with previously reported predictions suggesting that fish ground speed should not change with head current velocity. We suggest that this difference is due to different assumptions on fish swimming energetics. We conclude that fish are able to adjust both swimming speed and timing of swimming activity during migration to changes in head current velocity in order to minimize energy use.

  10. Optimal swimming speed in head currents and effects on distance movement of winter-migrating fish

    DEFF Research Database (Denmark)

    Brodersen, J.; Nilsson, P.A.; Ammitzbøl, J.

    2008-01-01

    ecologically and economically important. We here use passive and active telemetry to study how winter migrating roach regulate swimming speed and distance travelled per day in response to variations in head current velocity. Furthermore, we provide theoretical predictions on optimal swimming speeds in head....... Such variation can, for instance, arise from changes in wind or current velocity for migrating birds and fish, respectively. Whereas behavioural responses of birds to such changing environmental conditions have been relatively well described, this is not the case for fish, although fish migrations are both...... currents and relate these to our empirical results. We show that fish migrate farther on days with low current velocity, but travel at a greater ground speed on days with high current velocity. The latter result agrees with our predictions on optimal swimming speed in head currents, but disagrees...

  11. THE EFFECTS OF DIFFERENT MODELS OF SWIMMING TRAINING (DEFINED IN RELATION TO ANAEROBIC THRESHOLD ON THE INCREASE OF SWIM SPEED

    Directory of Open Access Journals (Sweden)

    Dragan Krivokapić

    2007-05-01

    treatments had signifi cant impact on the increase of swim speed at 400m and 50 m measured in the moment of reaching the anaerobic threshold.

  12. Scaling of swim speed and stroke frequency in geometrically similar penguins: they swim optimally to minimize cost of transport

    Science.gov (United States)

    Sato, Katsufumi; Shiomi, Kozue; Watanabe, Yuuki; Watanuki, Yutaka; Takahashi, Akinori; Ponganis, Paul J.

    2010-01-01

    It has been predicted that geometrically similar animals would swim at the same speed with stroke frequency scaling with mass−1/3. In the present study, morphological and behavioural data obtained from free-ranging penguins (seven species) were compared. Morphological measurements support the geometrical similarity. However, cruising speeds of 1.8–2.3 m s−1 were significantly related to mass0.08 and stroke frequencies were proportional to mass−0.29. These scaling relationships do not agree with the previous predictions for geometrically similar animals. We propose a theoretical model, considering metabolic cost, work against mechanical forces (drag and buoyancy), pitch angle and dive depth. This new model predicts that: (i) the optimal swim speed, which minimizes the energy cost of transport, is proportional to (basal metabolic rate/drag)1/3 independent of buoyancy, pitch angle and dive depth; (ii) the optimal speed is related to mass0.05; and (iii) stroke frequency is proportional to mass−0.28. The observed scaling relationships of penguins support these predictions, which suggest that breath-hold divers swam optimally to minimize the cost of transport, including mechanical and metabolic energy during dive. PMID:19906666

  13. How body torque and Strouhal number change with swimming speed and developmental stage in larval zebrafish.

    Science.gov (United States)

    van Leeuwen, Johan L; Voesenek, Cees J; Müller, Ulrike K

    2015-09-06

    Small undulatory swimmers such as larval zebrafish experience both inertial and viscous forces, the relative importance of which is indicated by the Reynolds number (Re). Re is proportional to swimming speed (vswim) and body length; faster swimming reduces the relative effect of viscous forces. Compared with adults, larval fish experience relatively high (mainly viscous) drag during cyclic swimming. To enhance thrust to an equally high level, they must employ a high product of tail-beat frequency and (peak-to-peak) amplitude fAtail, resulting in a relatively high fAtail/vswim ratio (Strouhal number, St), and implying relatively high lateral momentum shedding and low propulsive efficiency. Using kinematic and inverse-dynamics analyses, we studied cyclic swimming of larval zebrafish aged 2-5 days post-fertilization (dpf). Larvae at 4-5 dpf reach higher f (95 Hz) and Atail (2.4 mm) than at 2 dpf (80 Hz, 1.8 mm), increasing swimming speed and Re, indicating increasing muscle powers. As Re increases (60 → 1400), St (2.5 → 0.72) decreases nonlinearly towards values of large swimmers (0.2-0.6), indicating increased propulsive efficiency with vswim and age. Swimming at high St is associated with high-amplitude body torques and rotations. Low propulsive efficiencies and large yawing amplitudes are unavoidable physical constraints for small undulatory swimmers. © 2015 The Author(s).

  14. Ontogeny of swimming speed, schooling behaviour and jellyfish avoidance by Japanese anchovy Engraulis japonicus.

    Science.gov (United States)

    Masuda, R

    2011-05-01

    The ontogeny of swimming speed, schooling behaviour and jellyfish avoidance was studied in hatchery-reared Japanese anchovy Engraulis japonicus to compare its life-history strategy with two other common pelagic fishes, jack mackerel Trachurus japonicus and chub mackerel Scomber japonicus. Cruise swimming speed of E. japonicus increased allometrically from 1·4 to 3·9 standard length (L(S) ) per s (L(S) s(-1) ) from early larval to metamorphosing stage. Burst swimming speed also increased from 6·1 to 28 L(S) s(-1) in these stages. Cruise speed was inferior to that of S. japonicus, as was burst speed to that of T. japonicus. Engraulis japonicus larvae were highly vulnerable to predation by moon jellyfish Aurelia aurita and were readily eaten until they reached 23 mm L(S) , but not at 26 mm L(S) . Schooling behaviour (indicated by parallel swimming) started at c. 17 mm L(S) . Average distance to the nearest neighbour was shorter than values reported in other pelagic fishes. The relatively low predator avoidance capability of E. japonicus may be compensated for by their transparent and thus less conspicuous body, in addition to their early maturation and high fecundity. © 2011 The Author. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  15. Instrumental Develovement of 50 Meters Free Style Swimming Speed Measurement Based on Microcontroller Arduino Uno

    Science.gov (United States)

    Badruzaman; Rusdiana, A.; Gilang, M. R.; Martini, T.

    2017-03-01

    This study is purposed to make a software and hardware instrument in controlling the velocity of 50 meters free style swimming speed measurement based on microcontroller Arduino Uno. The writer uses 6 participants of advanced 2015 college students of sport education. The materials he uses are electronical series of microcontroller Arduino Uno base, laser sensors shone on light dependent resistor, laser receiver functions as a detector of laser cutting block, cables as connector transfering the data. This device consist of 4 installable censors in every 10 meters with the result of swimming speed showed on the monitors using visual basic 6.0 software. This instrument automatically works when the buzzer is pushed and also runs the timer on the application. For the procedure, the writer asks the participants to swim in free style along 50 meters. When the athlete swims, they will cut the laser of every censors so that it gives a signal to stop the running timer on the monitoring application. The output result the writer gets from this used instrument is to know how fast a swimmer swim in maximum speed, to know the time and distance of acceleration and decelaration that happens. The result of validity instrument shows 0,605 (high), while the reliability is 0,833 (very high).

  16. Swimming

    Science.gov (United States)

    ... But you might run into some jellyfish or Portuguese man-of-wars. These umbrella-shaped, nearly clear ... Here are some other good water safety tips: Learn to swim. Ask your parents to contact your ...

  17. Radio-transmitted electromyogram signals as indicators of swimming speed in lake trout and brown trout

    DEFF Research Database (Denmark)

    Thorstad, E.B.; Økland, F.; Koed, Anders

    2000-01-01

    Swimming speed and average electromyogram (EMG) pulse intervals were highly correlated in individual lake trout Salvelinus namaycush (r(2)=0.52-0.89) and brown trout Salmo trutta (r(2)=0.45-0.96). High correlations were found also for pooled data in both lake trout (r(2)=0.90) and brown trout...

  18. Planimetric frontal area in the four swimming strokes: implications for drag, energetics and speed.

    Science.gov (United States)

    Gatta, Giorgio; Cortesi, Matteo; Fantozzi, Silvia; Zamparo, Paola

    2015-02-01

    The purpose of this study was to use the planimetric method to determine frontal area (Ap) throughout the stroke cycle in the four swimming strokes as well as during "streamlined leg kicking". The minimum Ap values in all strokes are similar to those assessed during "streamlined leg kicking" (about 0.13m(2)). Active drag (Da=1/2ρ Cd Ap v(2)) was then calculated/estimated based on the average Ap values, as calculated for a full cycle in each condition. Da is the lowest in the "streamlined leg kicking" condition (Da=19.5v(2), e.g., similar to the values of passive drag reported in the literature), is similar in front crawl (Da=30.0v(2)), backstroke (Da=26.9v(2)) and butterfly (Da=28.5v(2)) and is the largest in the breaststroke (Da=37.5v(2)). Based on the C vs. v relationships reported in the literature for the four strokes it is then possible to estimate drag efficiency: for a speed of 1.5ms(-1), it ranges from 0.035-0.038 (breaststroke and backstroke, respectively) to 0.052-0.058 (butterfly and front crawl, respectively). This study is the first to establish Ap values throughout the swimming cycle for all swimming strokes and these findings have implications for active drag estimates, for the energetics of swimming and for swimming speed. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Center of mass motion in swimming fish: effects of speed and locomotor mode during undulatory propulsion.

    Science.gov (United States)

    Xiong, Grace; Lauder, George V

    2014-08-01

    Studies of center of mass (COM) motion are fundamental to understanding the dynamics of animal movement, and have been carried out extensively for terrestrial and aerial locomotion. But despite a large amount of literature describing different body movement patterns in fishes, analyses of how the center of mass moves during undulatory propulsion are not available. These data would be valuable for understanding the dynamics of different body movement patterns and the effect of differing body shapes on locomotor force production. In the present study, we analyzed the magnitude and frequency components of COM motion in three dimensions (x: surge, y: sway, z: heave) in three fish species (eel, bluegill sunfish, and clown knifefish) swimming with four locomotor modes at three speeds using high-speed video, and used an image cross-correlation technique to estimate COM motion, thus enabling untethered and unrestrained locomotion. Anguilliform swimming by eels shows reduced COM surge oscillation magnitude relative to carangiform swimming, but not compared to knifefish using a gymnotiform locomotor style. Labriform swimming (bluegill at 0.5 body lengths/s) displays reduced COM sway oscillation relative to swimming in a carangiform style at higher speeds. Oscillation frequency of the COM in the surge direction occurs at twice the tail beat frequency for carangiform and anguilliform swimming, but at the same frequency as the tail beat for gymnotiform locomotion in clown knifefish. Scaling analysis of COM heave oscillation for terrestrial locomotion suggests that COM heave motion scales with positive allometry, and that fish have relatively low COM oscillations for their body size. Copyright © 2014 Elsevier GmbH. All rights reserved.

  20. Acidification reduced growth rate but not swimming speed of larval sea urchins

    Science.gov (United States)

    Chan, Kit Yu Karen; García, Eliseba; Dupont, Sam

    2015-01-01

    Swimming behaviors of planktonic larvae impact dispersal and population dynamics of many benthic marine invertebrates. This key ecological function is modulated by larval development dynamics, biomechanics of the resulting morphology, and behavioral choices. Studies on ocean acidification effects on larval stages have yet to address this important interaction between development and swimming under environmentally-relevant flow conditions. Our video motion analysis revealed that pH covering present and future natural variability (pH 8.0, 7.6 and 7.2) did not affect age-specific swimming of larval green urchin Strongylocentrotus droebachiensis in still water nor in shear, despite acidified individuals being significantly smaller in size (reduced growth rate). This maintenance of speed and stability in shear was accompanied by an overall change in size-corrected shape, implying changes in swimming biomechanics. Our observations highlight strong evolutionary pressure to maintain swimming in a varying environment and the plasticity in larval responses to environmental change. PMID:25978405

  1. Energetics of swimming at maximal speeds in humans.

    Science.gov (United States)

    Capelli, C; Pendergast, D R; Termin, B

    1998-10-01

    The energy cost per unit of distance (Cs, kilojoules per metre) of the front-crawl, back, breast and butterfly strokes was assessed in 20 elite swimmers. At sub-maximal speeds (v), Cs was measured dividing steady-state oxygen consumption (VO2) by the speed (v, metres per second). At supra-maximal v, Cs was calculated by dividing the total metabolic energy (E, kilojoules) spent in covering 45.7, 91.4 and 182.9 m by the distance. E was obtained as: E = Ean + alphaVO2maxtp - alphaVO2maxtau(1 - e(-(tp/tau))), where Ean was the amount of energy (kilojoules) derived from anaerobic sources, VO2max litres per second was the maximal oxygen uptake, alpha( = 20.9 kJ x 1 O2(-1)) was the energy equivalent of O2, tau (24 s) was the time constant assumed for the attainment of VO2max at muscle level at the onset of exercise, and tp (seconds) was the performance time. The lactic acid component was assumed to increase exponentially with tp to an asymptotic value of 0.418 kJ x kg(-1) of body mass for tp> or =120 s. The lactic acid component of Ean was obtained from the net increase of lactate concentration after exercise (delta[La]b) assuming that, when delta[La]b = 1 mmol x 1(-1) the net amount of metabolic energy released by lactate formation was 0.069 kJ x kg(-1). Over the entire range of v, front crawl was the least costly stroke. For example at 1 m x s(-1), Cs amounted, on average, to 0.70, 0.84, 0.82 and 0.124 kJ x m(-1) in front crawl, backstroke, butterfly and breaststroke, respectively; at 1.5 m x s(-1), Cs was 1.23, 1.47, 1.55 and 1.87 kJ x m(-1) in the four strokes, respectively. The Cs was a continuous function of the speed in all of the four strokes. It increased exponentially in crawl and backstroke, whereas in butterfly Cs attained a minimum at the two lowest v to increase exponentially at higher v. The Cs in breaststroke was a linear function of the v, probably because of the considerable amount of energy spent in this stroke for accelerating the body during the

  2. Comparative evidence for the evolution of sperm swimming speed by sperm competition and female sperm storage duration in passerine birds.

    Science.gov (United States)

    Kleven, Oddmund; Fossøy, Frode; Laskemoen, Terje; Robertson, Raleigh J; Rudolfsen, Geir; Lifjeld, Jan T

    2009-09-01

    Sperm swimming speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm swimming speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm swimming speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm swimming speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm swimming speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm swimming speed.

  3. Effects of temperature, swimming speed and body mass on standard and active metabolic rate in vendace (Coregonus albula).

    Science.gov (United States)

    Ohlberger, Jan; Staaks, Georg; Hölker, Franz

    2007-11-01

    This study gives an integrated analysis of the effects of temperature, swimming speed and body mass on standard metabolism and aerobic swimming performance in vendace (Coregonus albula (L.)). The metabolic rate was investigated at 4, 8 and 15 degrees C using one flow-through respirometer and two intermittent-flow swim tunnels. We found that the standard metabolic rate (SMR), which increased significantly with temperature, accounted for up to 2/3 of the total swimming costs at optimum speed (U (opt)), although mean U (opt) was high, ranging from 2.0 to 2.8 body lengths per second. Net swimming costs increased with swimming speed, but showed no clear trend with temperature. The influence of body mass on the metabolic rate varied with temperature and activity level resulting in scaling exponents (b) of 0.71-0.94. A multivariate regression analysis was performed to integrate the effects of temperature, speed and mass (AMR = 0.82M (0.93) exp(0.07T) + 0.43M (0.93) U (2.03)). The regression analysis showed that temperature affects standard but not net active metabolic costs in this species. Further, we conclude that a low speed exponent, high optimum speeds and high ratios of standard to activity costs suggest a remarkably efficient swimming performance in vendace.

  4. Data from: How body torque and Strouhal number change with swimming speed and developmental stage in larval zebrafish

    NARCIS (Netherlands)

    Leeuwen, van J.L.; Voesenek, C.J.; Müller, U.K.

    2015-01-01

    Small undulatory swimmers such as larval zebrafish experience both inertial and viscous forces, the relative importance of which is indicated by the Reynolds number (Re). Re is proportional to swimming speed (vswim) and body length; faster swimming reduces the relative effect of viscous forces.

  5. Development tools students' speed qualities in a period of swimming butterfly

    Directory of Open Access Journals (Sweden)

    Balamutova N.M.

    2010-02-01

    Full Text Available Three trainings systems are developed for speeding up for students with the middle level of qualification. 9 sportsmen took part in research. Among them there are 6 youths and 3 girls. For three months of trainings for the sportsmen of the second group it was exhaust 9 the most essential technical elements in swimming on 50 m. A middle index of improvement of results is 1,46 s. The considerable improvement of results is marked for students the first and third groups (used a method: to power and speed endurance.

  6. Energy savings in sea bass swimming in a school: measurements of tail beat frequency and oxygen consumption at different swimming speeds

    DEFF Research Database (Denmark)

    Herskin, J; Steffensen, JF

    1998-01-01

    Tail beat frequency of sea bass, Dicentrarchus labrax (L.) (23.5 ± 0·5 cm, LT), swimming at the front of a school was significantly higher than when swimming at the rear, for all water velocities tested from 14·8 to 32 cm s-1. The logarithm of oxygen consumption rate, and the tail beat frequency...... of solitary swimming sea bass (28·8 ± 0·4 cm, LT), were each correlated linearly with swimming speed, and also with one another. The tail beat frequency of individual fish was 9-14% lower when at the rear of a school than when at the front, corresponding to a 9-23% reduction in oxygen consumption rate....

  7. The Effects of Leg Kick on Swimming Speed and Arm-Stroke Efficiency in the Front Crawl.

    Science.gov (United States)

    Silveira, Ricardo Peterson; de Souza Castro, Flávio Antônio; Figueiredo, Pedro; Vilas-Boas, João Paulo; Zamparo, Paola

    2017-07-01

    To analyze the effects of swimming pace on the relative contribution of leg kick to swimming speed and to compare arm-stroke efficiency (ηF) assessed when swimming with the arms only (SAO) and while swimming front crawl (FCS) using individual and fixed adjustments to arm-stroke and leg-kick contribution to forward speed. Twenty-nine master swimmers (21 men, 8 women) performed SAO and FCS at 6 self-selected speeds from very slow to maximal. The average swimming speed (v), stroke frequency (SF), and stroke length (SL) were assessed in the central 10 m of the swimming pool. Then, a 2nd-order polynomial regression was used to obtain values of v at paired SF. The percentage difference in v between FCS and SAO, for each paired SF, was used to calculate the relative contributions of the arm stroke (AC) and leg kick (LC) to FCS. Then ηF was calculated using the indirect "paddle-wheel" approach in 3 different ways: using general, individual, and no adjustments to AC. The LC increased with SF (and speed) from -1% ± 4% to 11% ± 1% (P arm stroke and leg kick should be individually estimated to reduce errors when calculating arm-stroke efficiency at different speeds and in different swimmers.

  8. Efficiency analysis of the speed turns in the crawl stroke swimming.

    Directory of Open Access Journals (Sweden)

    Savchenko M.I.

    2011-02-01

    Full Text Available Contemporary approaches to improving technique of the speed in the crawl stroke swimming, namely roll-forward turn were considered in the paper. The performance efficiency is defined by the time covering 15 meter distance. The students of the sports mastering group aged 16-20 took part in the experiment. The video recordings of the Ukrainian, European and World Championships and Deflympic Games, and also chronometration during the department trainings served as the experimental data. The research showed that white improving the technical level of turns performance, the attention should be paid to the exact performance of all the elements of the turns.

  9. Swimming performance assessment in fishes.

    Science.gov (United States)

    Tierney, Keith B

    2011-05-20

    Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, pollution, hypoxia and temperature. This paper describes a flexible protocol to assess fish swimming performance using equipment in which water velocity can be controlled. The protocol involves one to several stepped increases in flow speed that are intended to cause fish to fatigue. Step speeds and their duration can be set to capture swimming abilities of different physiological and ecological relevance. Most frequently step size is set to determine critical swimming velocity (U(crit;)), which is intended to capture maximum sustained swimming ability. Traditionally this test has consisted of approximately ten steps each of 20 min duration. However, steps of shorter duration (e.g. 1 min) are increasingly being utilized to capture acceleration ability or burst swimming performance. Regardless of step size, swimming tests can be repeated over time to gauge individual variation and recovery ability. Endpoints related to swimming such as measures of metabolic rate, fin use, ventilation rate, and of behavior, such as the distance between schooling fish, are often included before, during and after swimming tests. Given the diversity of fish species, the number of unexplored research questions, and the importance of many species to global ecology and economic health, studies of fish swimming performance will remain popular and invaluable for the foreseeable future.

  10. Not So Fast: Swimming Behavior of Sailfish during Predator-Prey Interactions using High-Speed Video and Accelerometry.

    Science.gov (United States)

    Marras, Stefano; Noda, Takuji; Steffensen, John F; Svendsen, Morten B S; Krause, Jens; Wilson, Alexander D M; Kurvers, Ralf H J M; Herbert-Read, James; Boswell, Kevin M; Domenici, Paolo

    2015-10-01

    Billfishes are considered among the fastest swimmers in the oceans. Despite early estimates of extremely high speeds, more recent work showed that these predators (e.g., blue marlin) spend most of their time swimming slowly, rarely exceeding 2 m s(-1). Predator-prey interactions provide a context within which one may expect maximal speeds both by predators and prey. Beyond speed, however, an important component determining the outcome of predator-prey encounters is unsteady swimming (i.e., turning and accelerating). Although large predators are faster than their small prey, the latter show higher performance in unsteady swimming. To contrast the evading behaviors of their highly maneuverable prey, sailfish and other large aquatic predators possess morphological adaptations, such as elongated bills, which can be moved more rapidly than the whole body itself, facilitating capture of the prey. Therefore, it is an open question whether such supposedly very fast swimmers do use high-speed bursts when feeding on evasive prey, in addition to using their bill for slashing prey. Here, we measured the swimming behavior of sailfish by using high-frequency accelerometry and high-speed video observations during predator-prey interactions. These measurements allowed analyses of tail beat frequencies to estimate swimming speeds. Our results suggest that sailfish burst at speeds of about 7 m s(-1) and do not exceed swimming speeds of 10 m s(-1) during predator-prey interactions. These speeds are much lower than previous estimates. In addition, the oscillations of the bill during swimming with, and without, extension of the dorsal fin (i.e., the sail) were measured. We suggest that extension of the dorsal fin may allow sailfish to improve the control of the bill and minimize its yaw, hence preventing disturbance of the prey. Therefore, sailfish, like other large predators, may rely mainly on accuracy of movement and the use of the extensions of their bodies, rather than resorting

  11. Effects of crude oil and dispersed crude oil on the critical swimming speed of puffer fish, Takifugu rubripes.

    Science.gov (United States)

    Yu, Xiaoming; Xu, Chuancai; Liu, Haiying; Xing, Binbin; Chen, Lei; Zhang, Guosheng

    2015-05-01

    In order to examine the effects of crude oil and dispersed crude oil (DCO) on the swimming ability of puffer fish, Takifugu rubripes, the critical swimming speeds (U crit) of fish exposed to different concentrations of water-soluble fraction (WSF) of crude oil and DCO solution were determined in a swimming flume. WSF and DCO significantly affected the U crit of puffer fish (p puffer fish exposed to 136 mg L(-1) WSF and 56.4 mg L(-1) DCO decreased 48.7 % and 43.4 %, respectively. DCO was more toxic to puffer fish than WSF. These results suggested that crude oil and chemically dispersed oil could weaken the swimming ability of puffer fish.

  12. Validity and reliability of critical speed, critical stroke rate, and anaerobic capacity in relation to front crawl swimming performances.

    Science.gov (United States)

    Dekerle, J; Sidney, M; Hespel, J M; Pelayo, P

    2002-02-01

    The purpose of this investigation was to determine whether the concepts of critical swimming speed, critical stroke rate and anaerobic swimming capacity could be used by coaches as a reliable index in order to monitor endurance performances in competitive swimmers. The results of this study conducted with well-trained swimmers showed that the 30-min test velocity (V30) is not different from the critical swimming speed determined from 200- and 400-m tests but is overestimated by 3.2 %. Furthermore, a regression analysis of the number of stroke cycles on time calculated for each swimmer showed a linear relationship (r(2) greater than 0.99 and p less than 0.01). The 30-min stroke rate test (SR30) was not different from the critical stroke rate determined from 200- and 400-m tests after a correction of minus 3.9 %. These data suggest that the slope of this regression line represents the critical stroke rate defined as the maximal stroke rate value, which can theoretically be maintained continuously without exhaustion. Coaches could easily use critical swimming speed combined with critical stroke rate in order not only to set aerobic training loads but also to control the swimming technique during training. Besides, anaerobic swimming capacity (ASC) values defined as the y-intercept of the regression line between distance and time were not correlated (p > 0.05) with the determined distance over which a significant drop in the maximal speed could be noticed on a 25-m test. Thus, ASC does not provide a reliable estimation of the anaerobic capacity.

  13. Effects of feeding ration on larval swimming speed and responsiveness to predator attacks: Implications for cohort survival

    Science.gov (United States)

    Chick, J.H.; Van Den Avyle, M.J.

    2000-01-01

    We conducted laboratory experiments to examine the effects of feeding ration on the routine swimming speed of larval striped bass (Morone saxatilis) and their responsiveness to simulated-predator attacks. Striped bass were reared in low (7 prey ?? L-1), medium (354 prey ?? L-1), or high (740 prey ?? L-1) prey treatments from age 4 to 14 days posthatch. Larvae reared in the low-prey treatment had slower routine swimming speeds and shorter reactive distances and were less responsive to simulated-predator attacks. These differences were most pronounced after age 10 and appeared to be an effect of deteriorating larval condition rather than an effect of size. Simulation models were constructed for two potential fish predators, Alosa aestivalis and Pomoxis nigromaculatus, to examine how variation in growth rate, swimming speed, and responsiveness to predator attacks might influence mortality rate. Our simulations predicted that cohort mortality rate would decrease with increasing larval growth rates, even though faster routine swimming speed and growth rate increased encounter rates with predators. The influence of larval growth rate and responsiveness on mortality rate varied between the two predators, but cohorts experiencing no growth always had the greatest mortality rate.

  14. Swim Speed Tests as a Method for Differentiating the Profiles of Young Swimmers

    OpenAIRE

    Klara Šiljeg; Joško Sindik; Goran Leko

    2017-01-01

    Swimming tests are used in every training cycle and seasons with purpose of estimating swimming performance and evaluate certain training types. The focus of this study is an attempt to distinguish between the potential short-distance and longer-distance swimmers, as well as the swimmers who could have desirable profiles for particular swimming styles. For this purpose, several aims are given: () to determine the latent dimensions of the performances in swimming tests, conducted on various di...

  15. The Effect of Rehearsal Learning and Warm-up on the Speed of Different Swimming Strokes

    Science.gov (United States)

    Magno, Carlo; Mascardo, Elizabeth

    2009-01-01

    The study investigated the effects of rehearsal learning and warm-up exercise on the time of performing different swimming strokes. The study was conducted among 202 college freshmen students taking up a course on physical education concentrated in swimming. The design employed is a mixed factorial (2 X 2) where time of swimming is measured before…

  16. Simulated front crawl swimming performance related to critical speed and critical power

    NARCIS (Netherlands)

    Toussaint, H.M.; Wakayoshi, K.; Hollander, A.P.; Ogita, F.

    1998-01-01

    Purpose: Competitive pool swimming events range in distance from 50 to 1500 m. Given the difference in performance times (±23-1000 s), the contribution of the aerobic and anaerobic energy systems changes considerably with race distance. In training practice the regression line between swimming

  17. Swim speed, behavior, and movement of North Atlantic right whales (Eubalaena glacialis) in coastal waters of northeastern Florida, USA.

    Science.gov (United States)

    Hain, James H W; Hampp, Joy D; McKenney, Sheila A; Albert, Julie A; Kenney, Robert D

    2013-01-01

    In a portion of the coastal waters of northeastern Florida, North Atlantic right whales (Eubalaena glacialis) occur close to shore from December through March. These waters are included within the designated critical habitat for right whales. Data on swim speed, behavior, and direction of movement--with photo-identification of individual whales--were gathered by a volunteer sighting network working alongside experienced scientists and supplemented by aerial observations. In seven years (2001-2007), 109 tracking periods or "follows" were conducted on right whales during 600 hours of observation from shore-based observers. The whales were categorized as mother-calf pairs, singles and non-mother-calf pairs, and groups of 3 or more individuals. Sample size and amount of information obtained was largest for mother-calf pairs. Swim speeds varied within and across observation periods, individuals, and categories. One category, singles and non mother-calf pairs, was significantly different from the other two--and had the largest variability and the fastest swim speeds. Median swim speed for all categories was 1.3 km/h (0.7 kn), with examples that suggest swim speeds differ between within-habitat movement and migration-mode travel. Within-habitat right whales often travel back-and-forth in a north-south, along-coast, direction, which may cause an individual to pass by a given point on several occasions, potentially increasing anthropogenic risk exposure (e.g., vessel collision, fishing gear entanglement, harassment). At times, mothers and calves engaged in lengthy stationary periods (up to 7.5 h) that included rest, nursing, and play. These mother-calf interactions have implications for communication, learning, and survival. Overall, these behaviors are relevant to population status, distribution, calving success, correlation to environmental parameters, survey efficacy, and human-impacts mitigation. These observations contribute important parameters to conservation biology

  18. Swim speed, behavior, and movement of North Atlantic right whales (Eubalaena glacialis in coastal waters of northeastern Florida, USA.

    Directory of Open Access Journals (Sweden)

    James H W Hain

    Full Text Available In a portion of the coastal waters of northeastern Florida, North Atlantic right whales (Eubalaena glacialis occur close to shore from December through March. These waters are included within the designated critical habitat for right whales. Data on swim speed, behavior, and direction of movement--with photo-identification of individual whales--were gathered by a volunteer sighting network working alongside experienced scientists and supplemented by aerial observations. In seven years (2001-2007, 109 tracking periods or "follows" were conducted on right whales during 600 hours of observation from shore-based observers. The whales were categorized as mother-calf pairs, singles and non-mother-calf pairs, and groups of 3 or more individuals. Sample size and amount of information obtained was largest for mother-calf pairs. Swim speeds varied within and across observation periods, individuals, and categories. One category, singles and non mother-calf pairs, was significantly different from the other two--and had the largest variability and the fastest swim speeds. Median swim speed for all categories was 1.3 km/h (0.7 kn, with examples that suggest swim speeds differ between within-habitat movement and migration-mode travel. Within-habitat right whales often travel back-and-forth in a north-south, along-coast, direction, which may cause an individual to pass by a given point on several occasions, potentially increasing anthropogenic risk exposure (e.g., vessel collision, fishing gear entanglement, harassment. At times, mothers and calves engaged in lengthy stationary periods (up to 7.5 h that included rest, nursing, and play. These mother-calf interactions have implications for communication, learning, and survival. Overall, these behaviors are relevant to population status, distribution, calving success, correlation to environmental parameters, survey efficacy, and human-impacts mitigation. These observations contribute important parameters to

  19. Regulation of stroke pattern and swim speed across a range of current velocities: Diving by common eiders wintering in polynyas in the Canadian Arctic

    NARCIS (Netherlands)

    Heath, J.P.; Gilchrist, H.G.; Ydenberg, R.C.

    2006-01-01

    Swim speed during diving has important energetic consequences. Not only do costs increase as drag rises non-linearly with increasing speed, but speed also affects travel time to foraging patches and therefore time and energy budgets over the entire dive cycle. However, diving behaviour has rarely

  20. Swim Speed Tests as a Method for Differentiating the Profiles of Young Swimmers

    National Research Council Canada - National Science Library

    Klara Šiljeg; Joško Sindik; Goran Leko

    2017-01-01

    .... The focus of this study is an attempt to distinguish between the potential short-distance and longer-distance swimmers, as well as the swimmers who could have desirable profiles for particular swimming styles...

  1. Determination of Swimming Speeds and Energetic Demands of Upriver Migrating Fall Chinook Salmon (Oncorhynchus Tshawytscha) in the Klickitat River, Washington.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard S.; Geist, David R.; Confederated Tribes and Bands of the Yakama Nation, Washington

    2002-08-30

    This report describes a study conducted by Pacific Northwest National Laboratory for the Bonneville Power Administration's Columbia Basin Fish and Wildlife Program during the fall of 2001. The objective was to study the migration and energy use of adult fall chinook salmon (Oncorhynchus tshawytscha) traveling up the Klickitat River to spawn. The salmon were tagged with either surgically implanted electromyogram (EMG) transmitters or gastrically implanted coded transmitters and were monitored with mobile and stationary receivers. Swim speed and aerobic and anaerobic energy use were determined for the fish as they attempted passage of three waterfalls on the lower Klickitat River and as they traversed free-flowing stretches between, below, and above the falls. Of the 35 EMG-tagged fish released near the mouth of the Klickitat River, 40% passed the first falls, 24% passed the second falls, and 20% made it to Lyle Falls. None of the EMG-tagged fish were able to pass Lyle Falls, either over the falls or via a fishway at Lyle Falls. Mean swimming speeds ranged from as low as 52.6 centimeters per second (cm s{sup -1}) between falls to as high as 189 (cm s{sup -1}) at falls passage. Fish swam above critical swimming speeds while passing the falls more often than while swimming between the falls (58.9% versus 1.7% of the transmitter signals). However, fish expended more energy swimming the stretches between the falls than during actual falls passage (100.7 to 128.2 kilocalories [kcals] to traverse areas between or below falls versus 0.3 to 1.0 kcals to pass falls). Relationships between sex, length, and time of day on the success of falls passage were also examined. Average swimming speeds were highest during the day in all areas except at some waterfalls. There was no apparent relationship between either fish condition or length and successful passage of waterfalls in the lower Klickitat River. Female fall chinook salmon, however, had a much lower likelihood of

  2. Changes in sex difference in swimming speed in finalists at FINA World Championships and the Olympic Games from 1992 to 2013.

    Science.gov (United States)

    Wild, Stefanie; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat

    2014-01-01

    This study investigated swimming speeds and sex differences of finalists competing at the Olympic Games (i.e. 624 female and 672 male athletes) and FINA World Championships (i.e. 990 women and 1008 men) between 1992 and 2013. Linear, non-linear and multi-level regression models were used to investigate changes in swimming speeds and sex differences for champions and finalists. Regarding finalists in FINA World Championships and Olympic Games, swimming speed increased linearly in both women and men in all disciplines and race distances. Male world champions' swimming speed remained stable in 200 m butterfly, 400 m, 800 m and 1,500 m freestyle. Considering women, swimming speed remained unchanged in 50 m and 400 m freestyle. In the Olympic Games, swimming speed of male champions remained unchanged in 200 m breaststroke, 50 m, 400 m, 800 m and 1,500 m freestyle. Female Olympic champions' swimming speed remained stable in 100 m and 200 m backstroke, 100 m butterfly, 200 m individual medley, 50 m and 200 m freestyle. Evaluating sex differences between finalists in FINA World Championships, results showed a linear decrease in 100 m breaststroke and 200 m butterfly and a non-linear increase in 100 m backstroke. In finals at the Olympic Games, the sex difference decreased linearly for 100 m backstroke, 400 m and 800 m freestyle. However, a linear increase for 200 m butterfly can be reported. Considering Olympic and world champions, the sex difference remained stable in all disciplines and race distances. Swimming speed of the finalists at the Olympic Games and FINA World Championships increased linearly. The top annual female swimmers increased swimming speed rather at longer race distances (i.e. 800 m and 1,500 m freestyle, 200 m butterfly, and 400 m individual medley), whereas the top annual male swimmers increased it rather at shorter race distances (i.e. 100 m and 200 m freestyle, 100 m butterfly, and 100 m breaststroke). Sex difference

  3. Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length

    DEFF Research Database (Denmark)

    Svendsen, Morten Bo Søndergaard; Domenici, Paolo; Marras, Stefano

    2016-01-01

    , and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s(-1)), followed by barracuda (6.2±1.0 m s(-1)), little tunny (5.6±0.2 m s(-1)) and dorado (4...

  4. Growth-promoting effects of sustained swimming in fingerlings of gilthead sea bream (Sparus aurata L.).

    Science.gov (United States)

    Blasco, Josefina; Moya, A; Millán-Cubillo, A; Vélez, E J; Capilla, E; Pérez-Sánchez, J; Gutiérrez, J; Fernández-Borrás, J

    2015-12-01

    Fish growth is strongly influenced by environmental and nutritional factors and changing culture conditions can help optimize it. The importance of early-life experience on the muscle phenotype later in life is well known. Here, we study the effects of 5 weeks of moderate and sustained swimming activity (5 BL s(-1)) in gilthead sea bream during early development. We analysed growth and body indexes, plasma IGF-I and GH levels, feed conversion, composition [proximate and isotopic ((15)N/(13)C)] and metabolic key enzymes (COX, CS, LDH, HOAD, HK, ALAT, ASAT) of white muscle. Moderate and continuous exercise in fingerlings of gilthead sea bream increased plasma IGF-I, whereas it reduced plasma GH. Under these conditions, growth rate improved without any modification to feed intake through an increase in muscle mass and a reduction in mesenteric fat deposits. There were no changes in the content and turnover of muscle proteins and lipid reserves. Glycogen stores were maintained, but glycogen turnover was higher in white muscle of exercised fish. A lower LDH/CS ratio demonstrated an improvement in the aerobic capacity of white muscle, while a reduction in the COX/CS ratio possibly indicated a functional adaptation of mitochondria to adjust to the tissue-specific energy demand and metabolic fuel availability in exercised fish. We discuss the synergistic effects of dietary nutrients and sustained exercise on the different mitochondrial responses.

  5. Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

    Science.gov (United States)

    Gvoždík, Lumír; Smolinský, Radovan

    2015-11-02

    Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator-prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator-prey interactions and food web dynamics.

  6. The effect of thermal acclimation on aerobic scope and critical swimming speed in Atlantic salmon, Salmo salar.

    Science.gov (United States)

    Hvas, Malthe; Folkedal, Ole; Imsland, Albert; Oppedal, Frode

    2017-08-01

    The Atlantic salmon is extensively studied owing to conservation concerns and its economic importance in aquaculture. However, a thorough report of their aerobic capacity throughout their entire thermal niche has not been described. In this study, Atlantic salmon (∼450 g) were acclimated for 4 weeks at 3, 8, 13, 18 or 23°C, and then tested in a large Brett-type swimming respirometer in groups of 10 per trial. Both standard metabolic rate and active metabolic rate continued to increase with temperature, which resulted in an aerobic scope that also increased with temperature, but was statistically similar between 13, 18 and 23°C. The critical swimming speed peaked at 18°C (93.1±1.2 cm s-1), and decreased significantly at the extreme temperatures to 74.8±0.5 and 84.8±1.6 cm s-1 at 3 and 23°C, respectively. At 23°C, the accumulated mortality reached 20% over 4 weeks, while no fish died during acclimation at colder temperatures. Furthermore, fish at 23°C had poor appetite and lower condition factor despite still having a high aerobic scope, suggesting that oxygen uptake was not the limiting factor in the upper thermal niche boundary. In conclusion, Atlantic salmon were able to maintain a high aerobic capacity and good swimming capabilities throughout the entire thermal interval tested, thus demonstrating a high level of flexibility in respiratory capacity towards different temperature exposures. © 2017. Published by The Company of Biologists Ltd.

  7. Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited

    Directory of Open Access Journals (Sweden)

    Morten B. S. Svendsen

    2016-10-01

    Full Text Available Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s−1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s−1, followed by barracuda (6.2±1.0 m s−1, little tunny (5.6±0.2 m s−1 and dorado (4.0±0.9 m s−1; although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s−1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues.

  8. Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited.

    Science.gov (United States)

    Svendsen, Morten B S; Domenici, Paolo; Marras, Stefano; Krause, Jens; Boswell, Kevin M; Rodriguez-Pinto, Ivan; Wilson, Alexander D M; Kurvers, Ralf H J M; Viblanc, Paul E; Finger, Jean S; Steffensen, John F

    2016-10-15

    Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s-1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s-1), followed by barracuda (6.2±1.0 m s-1), little tunny (5.6±0.2 m s-1) and dorado (4.0±0.9 m s-1); although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s-1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues. © 2016. Published by The Company of Biologists Ltd.

  9. Sustained impairment of respiratory function and swim performance following acute oil exposure in a coastal marine fish.

    Science.gov (United States)

    Johansen, J L; Esbaugh, A J

    2017-06-01

    Acute exposure to crude oil polycyclic aromatic hydrocarbons (PAH) can severely impair cardiorespiratory function and swim performance of larval fish; however, the effects of acute oil exposure on later life stages and the capacity for subsequent recovery is less clear. Red drum (Sciaenops ocellatus) is an economically important apex predator native to the Gulf of Mexico, which was directly exposed to the 2010 Deep Water Horizon (DWH) oil spill. Here we examine impact and recovery of young adult red drum from exposure to concentrations of 0, 4.1, and 12.1μgL(-1) ΣPAH50 naturally weathered oil-water accommodated fractions (geometric mean), which are well within the range of concentrations measured during the DWH incident. We focused on aerobic scope (ASc), burst- and critical swimming speeds (Uburst and Ucrit), cost of transport (COT), as well as the capacity to repay oxygen debt following exhaustive exercise (EPOC), which are critical parameters for success of all life stages of fishes. A 24h acute exposure to 4.1μgL(-1) ΣPAH caused a significant 9.7 and 12.6% reduction of Uburst and Ucrit respectively, but no change in ASc, COT or EPOC, highlighting a decoupled effect on the respiratory and swimming systems. A higher exposure concentration, 12.1μgL(-1) ΣPAH, caused an 8.6 and 8.4% impairment of Uburst and Ucrit, as well as an 18.4% reduction in ASc. These impairments persisted six weeks post-exposure, suggesting that recorded impacts are entrenched. Large predatory fishes are critically dependent on the cardiorespiratory and swimming systems for ecological fitness, and long-term impairment of performance due to acute oil exposure suggests that even acute exposure events may have long lasting impacts on the ecological fitness of affected populations. Copyright © 2017. Published by Elsevier B.V.

  10. Swimming behaviour of juvenile Pacific lamprey, Lampetra tridentata

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, Dennis D.; Moursund, Russell A.; Bleich, Matthew D.

    2006-02-01

    Actively migrating juvenile Pacific lamprey (Lampetra tridentata Richardson, 1836) were collected from hydroelectric bypass facilities in the Columbia River and transferred to the laboratory to study their diel movement patterns and swimming ability. Volitional movement of lamprey was restricted mainly to night, with 94% of all swimming activity occurring during the 12-hr dark period. Burst speed of juvenile lamprey ranged from 56 to 94 cm/s with a mean of 71 ±5 cm/s or an average speed of 5.2 body lengths (BL)/s. Sustained swim speed for 5-min test intervals ranged from 0 to 46 cm/s with a median of 23 cm/s. Critical swimming speed was 36.0±10.0 cm/s and 2.4±0.6 BL/s. There was no significant relationship between fish length and critical swimming speed. Overall swimming performance of juvenile Pacific lamprey is low compared to that of most anadromous teleosts. Their poor swimming ability provides a challenge during the freshwater migration interval to the Pacific Ocean.

  11. The effects of course length on freestyle swimming speed in elite female and male swimmers - a comparison of swimmers at national and international level.

    Science.gov (United States)

    Wolfrum, Mathias; Knechtle, Beat; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2013-01-01

    Freestyle swimming performance over 50 m, 100 m, 200 m, 400 m, 800 m and 1,500 m was compared on short (25 m) and long (50 m) course for 92,196 national swimmers (i.e. annual high score list Switzerland) and 1,104 international swimmers (i.e. finalists FINA World Championships) from 2000 to 2012. National and international swimmers of both sexes were on average 2.0 ± 0.6% faster on short than on long course. Sex-related differences in swimming speed were greater on short than on long course for international and national swimmers from 50 m to 800 m. Freestyle swimming performance improved across years for international swimmers in both short- and long-course whereas only male national swimmers were able to improve on short and long course events except for short course events on 800 m and 1,500 m. Performance in national women competing in short and long course events showed only improvements on 50 m, 100 m and 1,500 m across years. The sex-related differences in freestyle swimming performance showed no change for international swimmers. For national swimmers, the sex-related differences in freestyle swimming performance increased over time in long course from 50 m to 800 m, but decreased for 1,500 m. In conclusion, elite female and male freestyle swimmers at national and international level were about 2% faster on 25 m compared to 50 m course. During the 2000-2012 period, international as well as national swimmers (i.e. for national level predominantly men) improved freestyle swimming performance in both long and short course. More vigorous and optimized training programs focused on muscular force production in combination with efficient swimming skills might close the performance gap between elite swimmers at national level and FINA finalists. Further research especially including effects of anthropometric, biomechanical, and physiological factors is required to fully understand the effects of course length on freestyle swimming performance, and to determine

  12. Function of the medial red muscle during sustained swimming in common thresher sharks: contrast and convergence with thunniform swimmers.

    Science.gov (United States)

    Bernal, Diego; Donley, Jeanine M; McGillivray, David G; Aalbers, Scott A; Syme, Douglas A; Sepulveda, Chugey

    2010-04-01

    Through convergent evolution tunas and lamnid sharks share thunniform swimming and a medial position of the red, aerobic swimming musculature. During continuous cruise swimming these muscles move uniformly out of phase with local body curvature and the surrounding white muscle tissue. This design results in thrust production primarily from the caudal fin rather than causing whole-body undulations. The common thresher shark (Family Alopiidae) is the only other fish known to share the same medial red muscle anatomy as the thunniform swimmers. However, the overall body shape and extremely heterocercal caudal fin of the common thresher is not shared with the thunniform swimmers, which have both fusiform bodies and high aspect-ratio, lunate caudal fins. Our study used sonomicrometry to measure the dynamics of red and white muscle movement in common thresher sharks swimming in the ocean to test whether the medial position of red muscle is associated with uncoupling of muscle shortening and local body bending as characteristic of thunniform swimmers. Common threshers ( approximately 60-100kg) instrumented with sonomicrometric and electromyographic (EMG) leads swam alongside of the vessel with a tail-beat frequency of approximately 0.5Hz. EMG signals confirmed that only the red muscle was active during sustained swimming. Despite the more medial position of the red muscle relative to the white muscle, its strain was approximately 1.5-times greater than that of the overlying white muscle, and there was a notable phase shift between strain trajectories in the red muscle and adjacent white muscle. These results suggest an uncoupling (shearing) of the red muscle from the adjacent white muscle. Although the magnitude of the phase shift between red and white muscle strain was relatively constant within individuals, it varied among sharks, ranging from near zero (red and white in phase) to almost 180 degrees out of phase. This extent in variability has not been documented

  13. Swimming Performance Assessment in Fishes

    OpenAIRE

    Tierney, Keith B.

    2011-01-01

    Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, pollution, hypoxia and temperature. This paper describes a flexible protocol to assess fish swimming performance using equipment in which water velocity can be controlled. The protocol involves one to several stepped increases in flow speed that are intended to cause fish to fatigue. Step speeds and their duration can be set to capture swimming ...

  14. Swimming Performance and Metabolism of Golden Shiners

    Science.gov (United States)

    The swimming ability and metabolism of golden shiners, Notemigonus crysoleucas, was examined using swim tunnel respirometery. The oxygen consumption and tail beat frequencies at various swimming speeds, an estimation of the standard metabolic rate, and the critical swimming speed (Ucrit) was determ...

  15. Swimming performance of the small characin Bryconamericus stramineus (Characiformes: Characidae

    Directory of Open Access Journals (Sweden)

    Miriam A. de Castro

    2010-01-01

    Full Text Available Very little research has been conducted on the swimming capacity of Neotropical fish. The few studies available have focused on large migratory species. The present study used fixed and increasing velocity tests to determine prolonged and sustained speeds of the "pequira", Bryconamericus stramineus Eigenmann, 1908, a small, abundant species found in fish passages implemented at the Paraná basin, Brazil. The results of increasing velocity tests showed significant relationships between critical speeds, total and standard lengths, and body weight. When compared with other Neotropical fish, the "pequira" is able to swim faster than individuals of other species of similar length. The point of change from sustained to prolonged swimming was found to occur at an approximate speed of 8.7 lengths per second. These data provide guidance and criteria for design and proper maintenance of structures such as fishways, fish screens and other systems that aim to facilitate or avoid upstream passages as part of management strategies.

  16. Energetics of swimming of a sea turtle.

    Science.gov (United States)

    Prange, H D

    1976-02-01

    Young (mean mass 735 g) green turtles (Chelonia mydas) were able to swim in a water channel at sustained speeds between 0-14 and 0-35 m.s-1. Oxygen consumption at rest was was 0-07 l.kg-1.h-1; at maximum swimming speed oxygen consumption was 3-4 times greater than at rest for a given individual. In comparison with other animals of the same body mass the cost of transport for the green turtle (0.186lO2.kg-1.km-1) is less than that for flying birds but greater than that for fish. From drag measurements it was calculated that the aerobic efficiency of swimming was between 1 and 10%; the higher efficiencies were found at the higher swimming speeds. Based upon the drag calculations for young turtles, it is estimated that adult turtles making the round-trip breeding migration between Brazil and Ascension Island (4800 km) would require the equivalent of about 21% of their body mass in fat stores to account for the energetic cost of swimming.

  17. Averaged Propulsive Body Acceleration (APBA Can Be Calculated from Biologging Tags That Incorporate Gyroscopes and Accelerometers to Estimate Swimming Speed, Hydrodynamic Drag and Energy Expenditure for Steller Sea Lions.

    Directory of Open Access Journals (Sweden)

    Colin Ware

    Full Text Available Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion-an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expenditures despite being unable to distinguish rotational movements from linear movements. However, recent miniaturizations of gyroscopes offer the possibility of resolving this shortcoming and obtaining better estimates of body accelerations of swimming animals. We derived accelerations using gyroscope data for swimming Steller sea lions (Eumetopias jubatus, and determined how well the measured accelerations correlated with actual swimming speeds and with theoretical drag. We also compared dive averaged dynamic body acceleration estimates that incorporate gyroscope data, with the widely used Overall Dynamic Body Acceleration (ODBA metric, which does not use gyroscope data. Four Steller sea lions equipped with biologging tags were trained to swim alongside a boat cruising at steady speeds in the range of 4 to 10 kph. At each speed, and for each dive, we computed a measure called Gyro-Informed Dynamic Acceleration (GIDA using a method incorporating gyroscope data with accelerometer data. We derived a new metric-Averaged Propulsive Body Acceleration (APBA, which is the average gain in speed per flipper stroke divided by mean stroke cycle duration. Our results show that the gyro-based measure (APBA is a better predictor of speed than ODBA. We also found that APBA can estimate average thrust production during a single stroke-glide cycle, and can be used to estimate energy expended during swimming. The gyroscope-derived methods we describe should be generally applicable in swimming animals where propulsive accelerations can be clearly identified in the signal

  18. Averaged Propulsive Body Acceleration (APBA) Can Be Calculated from Biologging Tags That Incorporate Gyroscopes and Accelerometers to Estimate Swimming Speed, Hydrodynamic Drag and Energy Expenditure for Steller Sea Lions

    Science.gov (United States)

    Trites, Andrew W.; Rosen, David A. S.; Potvin, Jean

    2016-01-01

    Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion—an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expenditures despite being unable to distinguish rotational movements from linear movements. However, recent miniaturizations of gyroscopes offer the possibility of resolving this shortcoming and obtaining better estimates of body accelerations of swimming animals. We derived accelerations using gyroscope data for swimming Steller sea lions (Eumetopias jubatus), and determined how well the measured accelerations correlated with actual swimming speeds and with theoretical drag. We also compared dive averaged dynamic body acceleration estimates that incorporate gyroscope data, with the widely used Overall Dynamic Body Acceleration (ODBA) metric, which does not use gyroscope data. Four Steller sea lions equipped with biologging tags were trained to swim alongside a boat cruising at steady speeds in the range of 4 to 10 kph. At each speed, and for each dive, we computed a measure called Gyro-Informed Dynamic Acceleration (GIDA) using a method incorporating gyroscope data with accelerometer data. We derived a new metric—Averaged Propulsive Body Acceleration (APBA), which is the average gain in speed per flipper stroke divided by mean stroke cycle duration. Our results show that the gyro-based measure (APBA) is a better predictor of speed than ODBA. We also found that APBA can estimate average thrust production during a single stroke-glide cycle, and can be used to estimate energy expended during swimming. The gyroscope-derived methods we describe should be generally applicable in swimming animals where propulsive accelerations can be clearly identified in the signal—and they should

  19. Reaction time, processing speed and sustained attention in schizophrenia: impact on social functioning.

    Science.gov (United States)

    Lahera, Guillermo; Ruiz, Alicia; Brañas, Antía; Vicens, María; Orozco, Arantxa

    Previous studies have linked processing speed with social cognition and functioning of patients with schizophrenia. A discriminant analysis is needed to determine the different components of this neuropsychological construct. This paper analyzes the impact of processing speed, reaction time and sustained attention on social functioning. 98 outpatients between 18 and 65 with DSM-5 diagnosis of schizophrenia, with a period of 3 months of clinical stability, were recruited. Sociodemographic and clinical data were collected, and the following variables were measured: processing speed (Trail Making Test [TMT], symbol coding [BACS], verbal fluency), simple and elective reaction time, sustained attention, recognition of facial emotions and global functioning. Processing speed (measured only through the BACS), sustained attention (CPT) and elective reaction time (but not simple) were associated with functioning. Recognizing facial emotions (FEIT) correlated significantly with scores on measures of processing speed (BACS, Animals, TMT), sustained attention (CPT) and reaction time. The linear regression model showed a significant relationship between functioning, emotion recognition (P=.015) and processing speed (P=.029). A deficit in processing speed and facial emotion recognition are associated with worse global functioning in patients with schizophrenia. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Individual variation in thermal performance curves: swimming burst speed and jumping endurance in wild-caught tropical clawed frogs.

    Science.gov (United States)

    Careau, Vincent; Biro, Peter A; Bonneaud, Camille; Fokam, Eric B; Herrel, Anthony

    2014-06-01

    The importance of studying individual variation in locomotor performance has long been recognized as it may determine the ability of an organism to escape from predators, catch prey or disperse. In ectotherms, locomotor performance is highly influenced by ambient temperature (Ta), yet several studies have showed that individual differences are usually retained across a Ta gradient. Less is known, however, about individual differences in thermal sensitivity of performance, despite the fact that it could represent adaptive sources of phenotypic variation and/or additional substrate for selection to act upon. We quantified swimming and jumping performance in 18 wild-caught tropical clawed frogs (Xenopus tropicalis) across a Ta gradient. Maximum swimming velocity and acceleration were not repeatable and individuals did not differ in how their swimming performance varied across Ta. By contrast, time and distance jumped until exhaustion were repeatable across the Ta gradient, indicating that individuals that perform best at a given Ta also perform best at another Ta. Moreover, thermal sensitivity of jumping endurance significantly differed among individuals, with individuals of high performance at low Ta displaying the highest sensitivity to Ta. Individual differences in terrestrial performance increased with decreasing Ta, which is opposite to results obtained in lizards at the inter-specific and among-individual levels. To verify the generality of these patterns, we need more studies on individual variation in thermal reaction norms for locomotor performance in lizards and frogs.

  1. SWIMMING BEHAVIOR OF DEVELOPMENTAL STAGES OF THE CALANOID COPEPOD TEMORA-LONGICORNIS AT DIFFERENT FOOD CONCENTRATIONS

    NARCIS (Netherlands)

    VANDUREN, LA; VIDELER, JJ

    1995-01-01

    The swimming behaviour of developmental stages of the marine calanoid copepod Temora longicornis was studied using 2-dimensional observations under a microscope and a 3-dimensional filming technique to analyze swimming mode, swimming speed and swimming trajectories under different food

  2. Ciliary-propelling mechanism, effect of temperature and viscosity on swimming speed, and adaptive significance of ‘jumping’ in the ciliate Mesodinium rubrum

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2009-01-01

    law Vs ~ µ^-n, n~1.93. For small M. rubrum, swimming velocity decreased from 6.1 +/- 1.3 mm/s at 21.1C to 3.8 +/- 0.3 mm/s at 9.5C, while the power-law exponent was n ~ 1.4 and 3 for changing temperature and temperature equivalent, respectively, but with n ~ 1.96 for all data taken together....... The results, supplemented with an analysis of a hydrodynamic model for self-propagation of an idealized micro-organism, support the hypothesis that the response is mainly physical/mechanical rather than biological. Since the jump-speed of M. rubrum is nearly the same for all tracks of varying jumplengths...

  3. Swimming performance and metabolism of cultured golden shiners

    Science.gov (United States)

    The swimming ability and metabolism of golden shiners, Notemigonus crysoleucas, was examined using swim tunnel respirometery. The oxygen consumption and tail beat frequencies at various swimming speeds, an estimation of the standard metabolic rate, and the critical swimming speed (Ucrit) was determ...

  4. Estimating Burst Swim Speeds and Jumping Characteristics of Silver Carp (Hypophthalmichthys molitrix) Using Video Analyses and Principles of Projectile Physics

    Science.gov (United States)

    2016-09-01

    Applying principles of projectile physics to a subset of those fish (N=4), burst speeds were estimated as 7.78- 9.74 m/s, angle of leap as 44-70º, and...rectilinear and boundary layer flow. Journal of Applied Ichthyology 27:226–230. ERDC/TN ANSRP-16-2 September 2016 11 Hunn, J. B., and W. D. Youngs...1980. Role of physical barriers in the control of sea lamprey (Petromyzon marinus). Canadian Journal of Fisheries and Aquatic Sciences 37(11):2118–2122

  5. An analysis of the energetic cost of the branchial and cardiac pumps during sustained swimming in trout

    DEFF Research Database (Denmark)

    FARRELL, AP; STEFFENSEN, JF

    1987-01-01

    Experimental data are available for the oxygen cost of the branchial and cardiac pumps in fish. These data were used to theoretically analyze the relative oxygen cost of these pumps during rest and swimming in rainbow troutSalmo gairdneri. Efficiency of the heart increases with activity and so...

  6. Velocidade crítica em natação: fundamentos e aplicação Critical speed in swimming: theoretical basis and application

    Directory of Open Access Journals (Sweden)

    Marcos Franken

    2011-03-01

    Full Text Available O objetivo deste artigo foi efetuar uma revisão da origem do conceito e da aplicação da velocidade crítica (VC na natação. Em relação ao significado fisiológico, aumentos substanciais de alguns marcadores fisiológicos (concentração de lactato, consumo de oxigênio e frequência cardíaca foram observados durante esforços em intensidade retangular à VC, sugerindo que esta se situe acima do limiar anaeróbio e também da máxima fase estável de lactato. É sugerido que a VC seja influenciada por alguns fatores como: (1 utilização de diferentes combinações de distâncias para a sua determinação; (2 diferentes faixas etárias e (3 nível de experiência do nadador. Pode-se concluir que a VC é um adequado parâmetro para o controle dos efeitos do treinamento, e pode ser obtida de maneira simples em relação a outras formas de controle. No entanto, sua utilização como ferramenta para a predição do desempenho em natação ainda necessita ser melhor investigada.The aim of this paper was to review the origin of the critical speed (CS concept and how it may be applied to swimming. Regarding the physiological significance, substantial increases in some physiological markers (blood lactate, oxygen consumption and heart rate were observed in rectangular intensity efforts during the CS, suggesting that this is above the anaerobic threshold and the maximal steady state lactate. Factors influencing CS are thought to include (1 using different combinations of distances used in the test to determine CS, (2 age of the individual, and (3 the swimmer's level of experience. It can be concluded that the CS represents an adequate tool for controlling training intensity and has the benefit of being comparatively simple to measure in relation to others forms of control. However, use of CS as a tool for predicting performance in swimming still needs further investigation.

  7. Hydrodynamic advantages of swimming by salp chains.

    Science.gov (United States)

    Sutherland, Kelly R; Weihs, Daniel

    2017-08-01

    Salps are marine invertebrates comprising multiple jet-propelled swimming units during a colonial life-cycle stage. Using theory, we show that asynchronous swimming with multiple pulsed jets yields substantial hydrodynamic benefit due to the production of steady swimming velocities, which limit drag. Laboratory comparisons of swimming kinematics of aggregate salps (Salpa fusiformis and Weelia cylindrica) using high-speed video supported that asynchronous swimming by aggregates results in a smoother velocity profile and showed that this smoother velocity profile is the result of uncoordinated, asynchronous swimming by individual zooids. In situ flow visualizations of W. cylindrica swimming wakes revealed that another consequence of asynchronous swimming is that fluid interactions between jet wakes are minimized. Although the advantages of multi-jet propulsion have been mentioned elsewhere, this is the first time that the theory has been quantified and the role of asynchronous swimming verified using experimental data from the laboratory and the field. © 2017 The Author(s).

  8. Energetics of median and paired fin swimming, body and caudal fin swimming, and gait transition in parrotfish (Scarus schlegeli) and triggerfish (Rhinecanthus aculeatus)

    DEFF Research Database (Denmark)

    Korsmeyer, Keith E; Steffensen, John Fleng; Herskin, Jannik

    2002-01-01

    To determine the energetic costs of rigid-body, median or paired-fin (MPF) swimming versus undulatory, body-caudal fin (BCF) swimming, we measured oxygen consumption as a function of swimming speed in two MPF swimming specialists, Schlegel's parrotfish and Picasso triggerfish. The parrotfish swam.......1 L s(-1) (30 min U(crit)). In both species, the rates of increase in oxygen consumption with swimming speed were higher during BCF swimming than during rigid-body MPF swimming. Our results indicate that, for these species, undulatory swimming is energetically more costly than rigid-body swimming......, and therefore support the hypothesis that MPF swimming is more efficient. In addition, use of the BCF gait at higher swimming speed increased the cost of transport in both species beyond that predicted for MPF swimming at the same speeds. This suggests that, unlike for terrestrial locomotion, gait transition...

  9. Swimming physiology.

    Science.gov (United States)

    Holmér, I

    1992-05-01

    Swimming takes place in a medium, that presents different gravitational and resistive forces, respiratory conditions and thermal stress compared to air. The energy cost of propulsion in swimming is high, but a considerable reduction occurs at a given velocity as result of regular swim training. In medley swimmers the energy cost is lowest for front crawl, followed by backstroke, butterfly and breast-stroke. Cardiac output is probably not limiting for performance since swimmers easily achieve higher values during running. Maximal heart rate, however, is lowered by approx. 10 beats/min during swimming compared to running. Most likely active muscle mass is smaller and rate of power production lesser in swimming. Local factors, such as peripheral circulation, capillary density, perfusion pressure and metabolic capacity of active muscles, are important determinants of the power production capacity and emphasize the role of swim specific training movements. Improved swimming technique and efficiency are likely to explain much of the continuous progress in performance. Rational principles based on improved understanding of the biomechanics and physiology of swimming should be guidelines for swimmers and coaches in their efforts to explore the limits of human performance.

  10. Comparison between swimming in clothes and swimming in swimming wear in view of physical and physiological exercise intensity in a group of children.

    OpenAIRE

    崔, 勝旭; 黒川, 隆志; 仰木, 孝治; 胡,泰志

    1995-01-01

    The comparison of the effect of swimming in swimming wear and swimming in T-shirts or in T-shirts and pants to the swimming speed, frequency and length of strokes, and heart rate was made with a view to preventing children from drowning accidents. Ten children were allowed to devote all their energy to swim a span of 25m with the front crawl stroke, the breast stroke and the back crawl stroke. The results were as follows: (1) The front crawl stroke in swimming wear showed the fastest swim...

  11. Swimming ability and physiological response to swimming fatigue in ...

    African Journals Online (AJOL)

    The swimming endurance of kuruma shrimp, Marsupenaeus japonicus (11.04 ± 2.43 g) at five swimming speeds (23.0, 26.7, 31.0, 34.6 and 38.6 cm s-1) was determined in a circulating flume at 25.7 ± 0.7°C. The plasma glucose and total protein, hepatopancreas and pleopods muscle glycogen concentrations were ...

  12. No evidence for a bioenergetic advantage from forced swimming in rainbow trout under a restrictive feeding regime

    DEFF Research Database (Denmark)

    Skov, Peter Vilhelm; Lund, Ivar; Margarido Pargana, Alexandre

    2015-01-01

    Sustained swimming at moderate speeds is considered beneficial in terms of the productive performance of salmonids, but the causative mechanisms have yet to be unequivocally established. In the present study, the effects of moderate exercise on the bioenergetics of rainbow trout were assessed...

  13. Estimating energy expenditure during front crawl swimming using accelerometers

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai Baastrup; Espinosa, Hugo G.; Van Thiel, David H

    2014-01-01

    The determination of energy expenditure is of major interest in training load and performance assessment. Small, wireless accelerometer units have the potential to characterise energy expenditure during swimming. The correlation between absorbed oxygen versus flume swimming speed and absorbed oxy...

  14. Speed Bumps on the Road to Sustainability - Energy Technology and Geopolitics

    Energy Technology Data Exchange (ETDEWEB)

    Mandil, C.; Taylor, P.; Van Der Linde, C.; Buchner, B.; Ramsay, W.C.; Lipponen, J.; Meier, A.; Berkeley, L.; Di Paola-Galloni, J.L.; Jaureguy-Naudin, M.; Charpin, J.M.; Segar, Ch.; Zaleski, P.; Lesourne, J.; Pires Santos, A.; Menard, D.; Neuhoff, K.; Oettinger, G.

    2011-07-01

    This document gathers the slides of the available presentations given at the 2011 issue of the annual Conference of the Ifri (French Institute of International Relations) Energy Program: 1 - An Energy revolution under way (Peter Taylor, Head of the Energy Technology Division, International Energy Agency); 2 - A look back at Cancun: 'top down' versus 'bottom up' (Barbara Buchner, Director of the CPI - Climate Policy Initiative - Venice office; 3 - CCS: Still in the Starting Blocks? (Juho Lipponen, Head of CCS Unit, International Energy Agency); 4 - Energy Efficiency: Does Anyone Care? (Alan Meier, Senior Scientist and Principal Investigator, Lawrence Berkeley National Laboratory); 5 - The Transport Sector: Anything Goes? (Jean-Luc di Paola-Galloni, Corporate Vice-President, Sustainable Development and External Affairs, Valeo Group); 6 - The Mediterranean Ring: Power or Politics? (Jean-Michel Charpin, Inspecteur General des Finances); 7 - Iran gas and Iraq oil (Chris Segar, Regional Analyst/Middle East and North Africa, International Energy Agency); 8 - Nuclear Power: New Players, New Game, New Rules (Pierre Zaleski, General delegate for the Center of Geopolitics of Energy and Raw Materials, Universite Paris-Dauphine); 9 - The Grid: a Generic Speed Bump (Antonio Pires Santos, Energy and Utilities Industry Leader, Southwest Europe, IBM); 10 - Intellectual Property Rights/Technology transfer (Dominique Menard, Partner, Hogan Lovells (Paris) LLP); 11 - Energy Markets: Conducive to Sustainability (Karsten Neuhoff, Director of the CPI - Climate Policy Initiative - Berlin office, German Institute for Economic Research, DIW Berlin)

  15. Swimming Droplets

    Science.gov (United States)

    Maass, Corinna C.; Krüger, Carsten; Herminghaus, Stephan; Bahr, Christian

    2016-03-01

    Swimming droplets are artificial microswimmers based on liquid droplets that show self-propelled motion when immersed in a second liquid. These systems are of tremendous interest as experimental models for the study of collective dynamics far from thermal equilibrium. For biological systems, such as bacterial colonies, plankton, or fish swarms, swimming droplets can provide a vital link between simulations and real life. We review the experimental systems and discuss the mechanisms of self-propulsion. Most systems are based on surfactant-stabilized droplets, the surfactant layer of which is modified in a way that leads to a steady Marangoni stress resulting in an autonomous motion of the droplet. The modification of the surfactant layer is caused either by the advection of a chemical reactant or by a solubilization process. Some types of swimming droplets possess a very simple design and long active periods, rendering them promising model systems for future studies of collective behavior.

  16. Theory of swimming filaments in viscoelastic media

    Science.gov (United States)

    Fu, Henry

    2008-03-01

    Microorganisms often encounter and must move through complex media. What aspects of propulsion are altered when swimming in viscoelastic gels and fluids? Motivated by the swimming of sperm through the mucus of the female mammalian reproductive tract, we examine the swimming of filaments in nonlinearly viscoelastic fluids. We obtain the swimming velocity and hydrodynamic force exerted on an infinitely long cylinder with prescribed beating pattern. We apply these results to study the swimming of a simplified sliding-filament model for a sperm flagellum. Viscoelasticity tends to decrease swimming speed. The viscoelastic response of the fluid can change the shapes of beating patterns, and changes in the beating patterns can even lead to reversal of the swimming direction.

  17. Krill (Meganyctiphanes norvegica) swim faster at night

    KAUST Repository

    Klevjer, Thor A.

    2011-05-01

    Krill are key members in marine food webs, and measurement of swimming speed is vital to assess their bioenergetic budgets, feeding, and encounters with predators. We document a consistent and marked diel signal in swimming speed of krill in their natural habitat that is not related to diel vertical migration. The results were obtained using a bottom-mounted, upward-looking echo sounder at 150-m depth in the Oslofjord, Norway, spanning 5 months from late autumn to spring at a temporal resolution of ~1–2 records s−1. Swimming speed was assessed using acoustic target tracking of individual krill. At the start of the registration period, both daytime and nocturnal average swimming speeds of Meganyctiphanes norvegica were ~ 3.5 cm s−1 (~ 1 body lengths ([bl] s−1) in waters with oxygen concentrations of ~ 15–20% O2 saturation. Following intrusion of more oxygenated water, nocturnal average swimming speeds increased to ~ 10 cm s−1 (~ 3 bl s−1), i.e., more than double that of daytime swimming speeds in the same period. We hypothesize that krill activity during the first period was limited by oxygen, and the enhanced swimming at night subsequent to the water renewal is due to increased feeding activity under lessened danger of predation in darkness.

  18. Swimming dynamics of bidirectional artificial flagella

    NARCIS (Netherlands)

    Namdeo, S.; Khaderi, S. N.; Onck, P. R.

    2013-01-01

    We study magnetic artificial flagella whose swimming speed and direction can be controlled using light and magnetic field as external triggers. The dependence of the swimming velocity on the system parameters (e. g., length, stiffness, fluid viscosity, and magnetic field) is explored using a

  19. Influence of time scale wind speed data on sustainability analysis for irrigating greenhouse crops

    Science.gov (United States)

    Díaz Méndez, Rodrigo; García Llaneza, Joaquín; Peillón, Manuel; Perdigones, Alicia; Sanchez, Raul; Tarquis, Ana M.; Garcia, Jose Luis

    2014-05-01

    Appropriate water supply at crop/farm level, with suitable costs, is becoming more and more important. Energy management is closely related to water supply in this context, being wind energy one of the options to be considered, using wind pumps for irrigation water supply. Therefore, it is important to characterize the wind speed frequency distribution to study the technical feasibility to use its energy for irrigation management purpose. The general objective of this present research is to analyze the impact of time scale recorded wind speed data in the sustainability for tomato (Solanum lycopersicum L.) grown under greenhouse at Cuban conditions using drip irrigation system. For this porpoise, a daily estimation balance between water needs and water availability was used to evaluate the feasibility of the most economic windmill irrigation system. Several factors were included: wind velocity (W, m/s) in function of the time scale averaged, flow supplied by the wind pump as a function of the elevation height (H, m) and daily greenhouse evapotranspiration. Monthly volumes of water required for irrigation (Dr, m3/ha) and in the water tank (Vd, m3), as well as the monthly irrigable area (Ar, ha), were estimated by cumulative deficit water budgeting taking in account these factors. Three-hourly wind velocity (W3h, m/s) data from 1992 till 2008 was available for this study. The original data was grouped in six and twelve hourly data (W6h and W12h respectively) as well as daily data (W24h). For each time scale the daily estimation balance was applied. A comparison of the results points out a need for at least three-hourly data to be used mainly in the months in which mean wind speed are close or below the pumps threshold speed to start-up functioning. References Manuel Esteban Peillon Mesa, Ana Maria Tarquis Alfonso, José Luis García Fernández, and Raúl Sánchez Calvo. The use of wind pumps for irrigating greenhouse tomato crops: a case study in Cuba. Geophysical

  20. A mechanism for efficient swimming

    Science.gov (United States)

    Haj-Hariri, Hossein; Saadat, Mehdi; Brandes, Aaron; Saraiya, Vishaal; Bart-Smith, Hilary

    2015-11-01

    We present experimental measurements of hydrodynamic performance as well as wake visualization for a freely swimming 3D foil with pure pitching motion. The foil is constrained to move in its axial direction. It is shown that the iso-lines for speed and input power (or economy) coincide in the dimensional frequency versus amplitude plane, up to a critical amplitude. The critical amplitude is independent from swimming speed. It is shown that all swimming gaits (combination of frequency and amplitude) share a single value for Strouhal number (for amplitudes below the critical amplitude), when plotted in non-dimensional frequency vs. amplitude plane. Additionally, it is shown that the swimming gaits with amplitudes equal to the critical amplitude are energetically superior to others. This finding provides a fundamental mechanism for an important observation made by Bainbridge (1958) namely, most fish (such as trout, dace, goldfish, cod and dolphins) maintain constant tail-beat amplitude during cruise, and their speed is correlated linearly with their tail-beat frequency. The results also support prior findings of Saadat and Haj-Hariri (2013). Supported by ONR MURI Grant N00014-14-1-0533.

  1. Swimming Eigenworms

    Science.gov (United States)

    van Bussel, Frank; Khan, Zeina; Rahman, Mizanur; Vanapalli, Siva; Blawzdziewicz, Jerzy

    2014-03-01

    The nematode C. Elegans is a much studied organism, with a fully mapped genome, cell structure, and nervous system; however, aspects of its behavior have yet to be elucidated, particularly with respect to motility under various conditions. Recently the ``Eigenworm'' technique has emerged as a promising avenue of exploration: via principle component analysis it has been shown that the state space of a healthy crawling worm is low dimensional, in that its shape can be well described by a linear combination of just four eigenmodes. So far, use of this methodology with swimming worms has been somewhat tentative, though medical research such as drug screening is commonly done with nematodes in fluid environments e.g. well plates. Here we give initial results for healthy worms swimming in liquids of varying viscosity. The main result is that at the low viscosities (M9 buffer solution) the state space is even lower dimensional than that for the crawling worm, with only two significant eigenmodes; and that as viscosity increases so does the number of modes needed for an adequate shape description. As well, the shapes of the eigenmodes undergo significant transitions across the range of viscosities looked at.

  2. Designing Sustainable Public Transportation: Integrated Optimization of Bus Speed and Holding Time in a Connected Vehicle Environment

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2016-11-01

    Full Text Available Developing public transportation and giving priority to buses is a feasible solution for improving the level of public transportation service, which facilitates congestion alleviation and prevention, and contributes to urban development and city sustainability. This paper presents a novel bus operation control strategy including both holding control and speed control to improve the level of service of transit systems within a connected vehicle environment. Most previous work focuses on optimization of signal timing to decrease the bus signal delay by assuming that holding control is not applied; the speed of buses is given as a constant input and the acceleration and deceleration processes of buses can be neglected. This paper explores the benefits of a bus operation control strategy to minimize the total cost, which includes bus signal delay, bus holding delay, bus travel delay, acceleration cost due to frequent stops and intense driving. A set of formulations are developed to explicitly capture the interaction between bus holding control and speed control. Experimental analysisand simulation tests have shown that the proposed integrated operational model outperforms the traditional control, speed control only, or holding control only strategies in terms of reducing the total cost of buses. The sensitivity analysis has further demonstrated the potential effectiveness of the proposed approach to be applied in a real-time bus operation control system under different levels of traffic demand, bus stop locations, and speed limits.

  3. Evaluation of the Finis Swimsense® and the Garmin SwimTM activity monitors for swimming performance and stroke kinematics analysis

    National Research Council Canada - National Science Library

    Mooney, Robert; Quinlan, Leo; Corley, Gavin; Godfrey, Alan; Osborough, Conor; ÓLaighin, Gearóid

    2017-01-01

    .... Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed...

  4. Factors affecting swimming performance of fasted rainbow trout with implications of exhaustive exercise on overwinter mortality

    Science.gov (United States)

    Simpkins, D.G.; Hubert, W.A.; Del Rio, C.M.; Rule, D.C.

    2004-01-01

    We evaluated the effects of body size, water temperature, and sustained swimming activity on swimming performance and the effects of exhaustive exercise on mortality of fasted juvenile rainbow trout. Fasting caused swimming performance to decline more rapidly for small fish than large fish, and warmer water temperatures and sustained swimming activity further decreased swimming performance. Exhaustive exercise increased mortality among fasted fish. Our observations suggest that juvenile rainbow trout with little or no food intake during winter can swim for long periods of time with little effect on mortality, but swimming to exhaustion can enhance mortality, especially among the smallest juveniles.

  5. Synchronised Swimming of Two Fish

    CERN Document Server

    Novati, Guido; Alexeev, Dmitry; Rossinelli, Diego; van Rees, Wim M; Koumoutsakos, Petros

    2016-01-01

    We study the fluid dynamics of two fish-like bodies with synchronised swimming patterns. Our studies are based on two-dimensional simulations of viscous incompressible flows. We distinguish between motion patterns that are externally imposed on the swimmers and self-propelled swimmers that learn manoeuvres to achieve certain goals. Simulations of two rigid bodies executing pre-specified motion indicate that flow-mediated interactions can lead to substantial drag reduction and may even generate thrust intermittently. In turn we examine two self-propelled swimmers arranged in a leader-follower configuration, with a-priori specified body-deformations. We find that the swimming of the leader remains largely unaffected, while the follower experiences either an increase or decrease in swimming speed, depending on the initial conditions. Finally, we consider a follower that synchronises its motion so as to minimise its lateral deviations from the leader's path. The leader employs a steady gait while the follower use...

  6. Comprehensive Sustainability Evaluation of High-Speed Railway (HSR Construction Projects Based on Unascertained Measure and Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Yongzhi Chang

    2018-02-01

    Full Text Available This paper aims to evaluate the sustainability of high-speed railway (HSR construction projects in a comprehensive manner. To this end, the author established an index system, involving 4 primary indices, 9 secondary indices, and 32 tertiary indices. The analytic hierarchy process (AHP and the unascertained measure were introduced to calculate the weights of these indices. Then, the index system was applied to evaluate the sustainability of the China’s Harbin-Dalian Passenger Dedicated Line (PDL. The results show that the Harbin-Dalian PDL project achieved good results in terms of process, economic benefit, impact, and sustainability, and will bring long-term benefits in the fields of tourism, economy, and transport capacity, as well as many other fields. In spite of its good overall sustainability, the project needs to further increase its economic benefits and reduce its negative environmental impact. For this purpose, it is necessary to adopt the management mode of “separation between network and transportation” and apply noise prevention measures like noise barriers, tunnels, and overhead viaducts. This research lays a solid basis for the sustainability evaluation of HSR construction projects, and simplifies the modelling process for designers of HSR.

  7. Optimal swimming strategies in mate searching pelagic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2008-01-01

    Male copepods must swim to find females, but swimming increases the risk of meeting predators and is expensive in terms of energy expenditure. Here I address the trade-offs between gains and risks and the question of how much and how fast to swim using simple models that optimise the number...... of lifetime mate encounters. Radically different swimming strategies are predicted for different feeding behaviours, and these predictions are tested experimentally using representative species. In general, male swimming speeds and the difference in swimming speeds between the genders are predicted...... and observed to increase with increasing conflict between mate searching and feeding. It is high in ambush feeders, where searching (swimming) and feeding are mutually exclusive and low in species, where the matured males do not feed at all. Ambush feeding males alternate between stationary ambush feeding...

  8. Swimming without a spine: Computational modeling and analysis of the swimming hydrodynamics of the Spanish Dancer.

    Science.gov (United States)

    Zhou, Zhuoyu; Mittal, Rajat

    2017-10-16

    Incompressible flow simulations are used to study the swimming of a Spanish Dancer (Hexabranchus sanguineus), a soft-bodied invertebrate marine gastropod that swims by combining body pitching with undulations of its large mantle. A simple model based on a field video is employed as the basis for the model and coupling of the flow with the body acceleration enables us to examine the free swimming of this animal. Simulations indicate propulsive efficiencies of up to about 57% and terminal swimming speeds of 1.33 body lengths per cycle. Examination of the effect of body planform on the swimming hydrodynamics suggests that the planform of this animal is likely adapted to enhance its swimming performance. © 2017 IOP Publishing Ltd.

  9. Sustainability Aspects of Energy Conversion in Modern High-Speed Trains with Traction Induction Motors

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2015-03-01

    Full Text Available Some aspects are illustrated of energy conversion processes during the operation of electric railway vehicles with traction induction motors, in order to support transport systems’ sustainability. Increasing efforts are being expended to enhance the sustainability of transportation technologies and systems. Since electric drive systems are used with variable voltage variable frequency (VVVF inverters and traction induction motors, these machines with appropriate controls can realize both traction and electric braking regimes for electric traction vehicles. In line with this idea, this paper addresses the operation sustainability of electric railway vehicles highlighting the chain of interactions among the main electric equipment on an electrically driven railway system supplied from an a.c. contact line: The contact line-side converter, the machine-side converter and the traction induction motor. The paper supports the findings that electric traction drive systems using induction motors fed by network-side converters and VVVF inverters enhance the sustainable operation of railway trains.

  10. Sustainability Aspects of Energy Conversion in Modern High-Speed Trains with Traction Induction Motors

    OpenAIRE

    Marc A. Rosen; Doru A. Nicola; Cornelia A. Bulucea; Daniel C. Cismaru

    2015-01-01

    Some aspects are illustrated of energy conversion processes during the operation of electric railway vehicles with traction induction motors, in order to support transport systems’ sustainability. Increasing efforts are being expended to enhance the sustainability of transportation technologies and systems. Since electric drive systems are used with variable voltage variable frequency (VVVF) inverters and traction induction motors, these machines with appropriate controls can realize both tra...

  11. PROPERTIES OF SWIMMING WATER

    Directory of Open Access Journals (Sweden)

    Tayfun KIR

    2004-10-01

    Full Text Available Swimming waters may be hazardous on human health. So, The physicians who work in the facilities, which include swimming areas, are responsible to prevent risks. To ensure hygiene of swimming water, European Swimming Water Directive offers microbiological, physical, and chemical criteria. [TAF Prev Med Bull 2004; 3(5.000: 103-104

  12. Real-time monitoring of swimming performance.

    Science.gov (United States)

    Delgado-Gonzalo, R; Lemkaddem, A; Renevey, Ph; Calvo, E Muntane; Lemay, M; Cox, K; Ashby, D; Willardson, J; Bertschi, M

    2016-08-01

    This article presents the performance results of a novel algorithm for swimming analysis in real-time within a low-power wrist-worn device. The estimated parameters are: lap count, stroke count, time in lap, total swimming time, pace/speed per lap, total swam distance, and swimming efficiency (SWOLF). In addition, several swimming styles are automatically detected. Results were obtained using a database composed of 13 different swimmers spanning 646 laps and 858.78 min of total swam time. The final precision achieved in lap detection ranges between 99.7% and 100%, and the classification of the different swimming styles reached a sensitivity and specificity above 98%. We demonstrate that a swimmers performance can be fully analyzed with the smart bracelet containing the novel algorithm. The presented algorithm has been licensed to ICON Health & Fitness Inc. for their line of wearables under the brand iFit.

  13. Repetition priming in picture naming: sustained learning through the speeding of multiple processes.

    Science.gov (United States)

    Francis, Wendy S

    2014-10-01

    Picture naming has been used by vision researchers to study object identification, by language researchers to study word production, and by memory researchers to study implicit memory. Response times for naming repeated pictures decrease with successive repetitions. Repetition priming in picture naming involves an implicit, nonhippocampal form of memory. In this review, the processes speeded with repetition are decomposed, the time course of the effect is characterized, the factors affecting the magnitude of priming are enumerated, and possible mechanisms of priming are evaluated. Both behavioral response time and neuroimaging studies are considered. The processes that are speeded with repetition include high-level object identification and word production processes, but not low-level visual processes or articulation. Repetition priming lasts for at least several weeks and follows a typical forgetting function. The mechanism of priming is concluded to be speeded completion of the component processes of picture naming.

  14. Exposure to cerium dioxide nanoparticles differently affect swimming performance and survival in two daphnid species

    National Research Council Canada - National Science Library

    Artells, Ester; Issartel, Julien; Auffan, Mélanie; Borschneck, Daniel; Thill, Antoine; Tella, Marie; Brousset, Lenka; Rose, Jérôme; Bottero, Jean-Yves; Thiéry, Alain

    2013-01-01

    .... Acute toxicity bioassays were performed to determine EC₅₀ of exposed daphnids. Video-recorded swimming behavior of both daphnids was used to measure swimming speeds after various exposures to aggregated CeO₂ NPs...

  15. Swimming and feeding of mixotrophic biflagellates

    DEFF Research Database (Denmark)

    Dölger, Julia; Nielsen, Lasse Tor; Kiørboe, Thomas

    2017-01-01

    Many unicellular flagellates are mixotrophic and access resources through both photosynthesis and prey capture. Their fitness depends on those processes as well as on swimming and predator avoidance. How does the flagellar arrangement and beat pattern of the flagellate affect swimming speed...... with variable position next to a no-slip sphere. Utilizing the observations and the model we find that puller force arrangements favour feeding, whereas equatorial force arrangements favour fast and quiet swimming. We determine the capture rates of both passive and motile prey, and we show that the flow...

  16. Swimming Motility Reduces Deposition to Silica Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Nanxi [Univ. of Illinois, Urbana-Champaign, IL (United States); Massoudieh, Arash [The Catholic Univ. of America, Washington, DC (United States); Liang, Xiaomeng [The Catholic Univ. of America, Washington, DC (United States); Hu, Dehong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kamai, Tamir [Agricultural Research Organization, Bet Dagan (Israel); Ginn, Timothy R. [Univ. of California, Davis, CA (United States); Zilles, Julie L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Nguyen, Thanh H. [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2015-01-01

    The role of swimming motility on bacterial transport and fate in porous media was evaluated. We present microscopic evidence showing that strong swimming motility reduces attachment of Azotobacter vinelandii cells to silica surfaces. Applying global and cluster statistical analyses to microscopic videos taken under non-flow conditions, wild type, flagellated A. vinelandii strain DJ showed strong swimming ability with an average speed of 13.1 μm/s, DJ77 showed impaired swimming averaged at 8.7 μm/s, and both the non-flagellated JZ52 and chemically treated DJ cells were non-motile. Quantitative analyses of trajectories observed at different distances above the collector of a radial stagnation point flow cell (RSPF) revealed that both swimming and non-swimming cells moved with the flow when at a distance of at least 20 μm from the collector surface. Near the surface, DJ cells showed both horizontal and vertical movement diverging them from reaching surfaces, while chemically treated DJ cells moved with the flow to reach surfaces, suggesting that strong swimming reduced attachment. In agreement with the RSPF results, the deposition rates obtained for two-dimensional multiple-collector micromodels were also lowest for DJ, while DJ77 and JZ52 showed similar values. Strong swimming specifically reduced deposition on the upstream surfaces of the micromodel collectors.

  17. Shape Optimization of Swimming Sheets

    Energy Technology Data Exchange (ETDEWEB)

    Wilkening, J.; Hosoi, A.E.

    2005-03-01

    The swimming behavior of a flexible sheet which moves by propagating deformation waves along its body was first studied by G. I. Taylor in 1951. In addition to being of theoretical interest, this problem serves as a useful model of the locomotion of gastropods and various micro-organisms. Although the mechanics of swimming via wave propagation has been studied extensively, relatively little work has been done to define or describe optimal swimming by this mechanism.We carry out this objective for a sheet that is separated from a rigid substrate by a thin film of viscous Newtonian fluid. Using a lubrication approximation to model the dynamics, we derive the relevant Euler-Lagrange equations to optimize swimming speed and efficiency. The optimization equations are solved numerically using two different schemes: a limited memory BFGS method that uses cubic splines to represent the wave profile, and a multi-shooting Runge-Kutta approach that uses the Levenberg-Marquardt method to vary the parameters of the equations until the constraints are satisfied. The former approach is less efficient but generalizes nicely to the non-lubrication setting. For each optimization problem we obtain a one parameter family of solutions that becomes singular in a self-similar fashion as the parameter approaches a critical value. We explore the validity of the lubrication approximation near this singular limit by monitoring higher order corrections to the zeroth order theory and by comparing the results with finite element solutions of the full Stokes equations.

  18. ARC Code TI: Swim

    Data.gov (United States)

    National Aeronautics and Space Administration — Swim is a software information service for the grid built on top of Pour, which is an information service framework developed at NASA. Swim provides true software...

  19. Swimming Pool Safety

    Science.gov (United States)

    ... Prevention Listen Español Text Size Email Print Share Swimming Pool Safety Page Content ​What is the best way to keep my child safe around swimming pools? An adult should actively watch children at ...

  20. 2012 Swimming Season Factsheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  1. A computational model of amoeboid cell swimming

    Science.gov (United States)

    Campbell, Eric J.; Bagchi, Prosenjit

    2017-10-01

    Amoeboid cells propel by generating pseudopods that are finger-like protrusions of the cell body that continually grow, bifurcate, and retract. Pseudopod-driven motility of amoeboid cells represents a complex and multiscale process that involves bio-molecular reactions, cell deformation, and cytoplasmic and extracellular fluid motion. Here we present a 3D model of pseudopod-driven swimming of an amoeba suspended in a fluid without any adhesion and in the absence of any chemoattractant. Our model is based on front-tracking/immersed-boundary methods, and it combines large deformation of the cell, a coarse-grain model for molecular reactions, and cytoplasmic and extracellular fluid flow. The predicted shapes of the swimming cell from our model show similarity with experimental observations. We predict that the swimming behavior changes from random-like to persistent unidirectional motion, and that the swimming speed increases, with increasing cell deformability and protein diffusivity. The unidirectionality in cell swimming is observed without any external cues and as a direct result of a change in pseudopod dynamics. We find that pseudopods become preferentially focused near the front of the cell and appear in greater numbers with increasing cell deformability and protein diffusivity, thereby increasing the swimming speed and making the cell shape more elongated. We find that the swimming speed is minimum when the cytoplasm viscosity is close to the extracellular fluid viscosity. We further find that the speed increases significantly as the cytoplasm becomes less viscous compared with the extracellular fluid, resembling the viscous fingering phenomenon observed in interfacial flows. While these results support the notion that softer cells migrate more aggressively, they also suggest a strong coupling between membrane elasticity, membrane protein diffusivity, and fluid viscosity.

  2. Methodics of obstacle swimming

    OpenAIRE

    Picka, Matěj

    2015-01-01

    Title: Methodics of Obstacle swimming Objective: The objectve of my disertation is to define requirments for Obstacle swimming and present the most effective methods for mastering in this discipline of Military Penthatlon Methods: Methods of pedagogical research Methods or theoretical and empirical research Results: The outcome of this thesis is to create methodics for obstacle swimming, show major mistakes in overcoming obstacles and give examples for ideal training session for swimming itse...

  3. HEALTHY AND SAFETY SWIMMING

    OpenAIRE

    Suleyman CEYLAN

    2005-01-01

    Swimming is a sport which has own rules, styles, and fields, however, is one of the most performed avocation as amateur and a joke especially at summer months. Although one of the most beneficial sports, swimming can cause a number of several health problems such as infectious diseases, allergic events, or traumas, if it is not done at adequate conditions and eligible style. In this paper, the factors such as preparing to swimming, health and safety features of swimming areas, important healt...

  4. Swimming Performance of Toy Robotic Fish

    Science.gov (United States)

    Petelina, Nina; Mendelson, Leah; Techet, Alexandra

    2015-11-01

    HEXBUG AquaBotsTM are a commercially available small robot fish that come in a variety of ``species''. These models have varying caudal fin shapes and randomly-varied modes of swimming including forward locomotion, diving, and turning. In this study, we assess the repeatability and performance of the HEXBUG swimming behaviors and discuss the use of these toys to develop experimental techniques and analysis methods to study live fish swimming. In order to determine whether these simple, affordable model fish can be a valid representation for live fish movement, two models, an angelfish and a shark, were studied using 2D Particle Image Velocimetry (PIV) and 3D Synthetic Aperture PIV. In a series of experiments, the robotic fish were either allowed to swim freely or towed in one direction at a constant speed. The resultant measurements of the caudal fin wake are compared to data from previous studies of a real fish and simplified flapping propulsors.

  5. Undulatory swimming in fluids with polymer networks

    CERN Document Server

    Gagnon, D A; Arratia, P E

    2013-01-01

    The motility behavior of the nematode Caenorhabditis elegans in polymeric solutions of varying concentrations is systematically investigated in experiments using tracking and velocimetry methods. As the polymer concentration is increased, the solution undergoes a transition from the semi-dilute to the concentrated regime, where these rod-like polymers entangle, align, and form networks. Remarkably, we find an enhancement in the nematode's swimming speed of approximately 65% in concentrated solutions compared to semi-dilute solutions. Using velocimetry methods, we show that the undulatory swimming motion of the nematode induces an anisotropic mechanical response in the fluid. This anisotropy, which arises from the fluid micro-structure, is responsible for the observed increase in swimming speed.

  6. Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis

    National Research Council Canada - National Science Library

    Robert Mooney; Leo R Quinlan; Gavin Corley; Alan Godfrey; Conor Osborough; Gearóid ÓLaighin

    2017-01-01

    .... Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed...

  7. Zebrafish swimming in the flow: a particle image velocimetry study

    Science.gov (United States)

    Romero Cruz, Sebastián

    2017-01-01

    Zebrafish is emerging as a species of choice for the study of a number of biomechanics problems, including balance development, schooling, and neuromuscular transmission. The precise quantification of the flow physics around swimming zebrafish is critical toward a mechanistic understanding of the complex swimming style of this fresh-water species. Although previous studies have elucidated the vortical structures in the wake of zebrafish swimming in placid water, the flow physics of zebrafish swimming against a water current remains unexplored. In an effort to illuminate zebrafish swimming in a dynamic environment reminiscent of its natural habitat, we experimentally investigated the locomotion and hydrodynamics of a single zebrafish swimming in a miniature water tunnel using particle image velocimetry. Our results on zebrafish locomotion detail the role of flow speed on tail beat undulations, heading direction, and swimming speed. Our findings on zebrafish hydrodynamics offer a precise quantification of vortex shedding during zebrafish swimming and demonstrate that locomotory patterns play a central role on the flow physics. This knowledge may help clarify the evolutionary advantage of burst and cruise swimming movements in zebrafish. PMID:29158978

  8. The effects of swimming pattern on the energy use of gilthead seabream (Sparus aurata L.)

    DEFF Research Database (Denmark)

    Steinhausen, Maria Faldborg; Steffensen, John Fleng; Andersen, Niels Gerner

    2010-01-01

    Oxygen consumption ( ) was measured for gilthead seabream (Sparus aurata) during spontaneous and forced activities. During spontaneous activity, the swimming pattern was analysed for the effect on   on the average speed (U), turning rate (¿) and change in speed (¿U). All swimming characteristics ......   at the respective optimum swimming speeds with the lowest cost of transport (Uopt) resulted in similar values independent of swimming mode. This could be an important observation in estimating energetic costs of free-ranging fishes.......Oxygen consumption ( ) was measured for gilthead seabream (Sparus aurata) during spontaneous and forced activities. During spontaneous activity, the swimming pattern was analysed for the effect on   on the average speed (U), turning rate (¿) and change in speed (¿U). All swimming characteristics...... contributed significantly to the source of spontaneous swimming costs, and the models explained up to 58% of the variation in   Prediction of   of fish in field studies can thereby be improved if changes in speed and direction are determined in addition to swimming speed. A relationship between swimming speed...

  9. Swimming and the heart.

    Science.gov (United States)

    Lazar, Jason M; Khanna, Neel; Chesler, Roseann; Salciccioli, Louis

    2013-09-20

    Exercise training is accepted to be beneficial in lowering morbidity and mortality in patients with cardiac disease. Swimming is a popular recreational activity, gaining recognition as an effective option in maintaining and improving cardiovascular fitness. Swimming is a unique form of exercise, differing from land-based exercises such as running in many aspects including medium, position, breathing pattern, and the muscle groups used. Water immersion places compressive forces on the body with resulting physiologic effects. We reviewed the physiologic effects and cardiovascular responses to swimming, the cardiac adaptations to swim training, swimming as a cardiac disease risk factor modifier, and the effects of swimming in those with cardiac disease conditions such as coronary artery disease, congestive heart failure and the long-QT syndrome. Published by Elsevier Ireland Ltd.

  10. HEALTHY AND SAFETY SWIMMING

    Directory of Open Access Journals (Sweden)

    Suleyman CEYLAN

    2005-08-01

    Full Text Available Swimming is a sport which has own rules, styles, and fields, however, is one of the most performed avocation as amateur and a joke especially at summer months. Although one of the most beneficial sports, swimming can cause a number of several health problems such as infectious diseases, allergic events, or traumas, if it is not done at adequate conditions and eligible style. In this paper, the factors such as preparing to swimming, health and safety features of swimming areas, important health behavior, wearing, feeding etc. that effected healthy swimming will be reviewed and evaluated. At the last part of the paper, it will be made some proposals to readers on healthy and safety swimming. [TAF Prev Med Bull 2005; 4(4.000: 209-221

  11. Undulatory swimming in viscoelastic fluids

    CERN Document Server

    Shen, Xiaoning

    2011-01-01

    The effects of fluid elasticity on the swimming behavior of the nematode \\emph{Caenorhabditis elegans} are experimentally investigated by tracking the nematode's motion and measuring the corresponding velocity fields. We find that fluid elasticity hinders self-propulsion. Compared to Newtonian solutions, fluid elasticity leads to 35% slower propulsion speed. Furthermore, self-propulsion decreases as elastic stresses grow in magnitude in the fluid. This decrease in self-propulsion in viscoelastic fluids is related to the stretching of flexible molecules near hyperbolic points in the flow.

  12. Fast-swimming hydromedusae exploit velar kinematics to form an optimal vortex wake

    OpenAIRE

    Dabiri, John O.; Colin, Sean P.; Costello, John H.

    2006-01-01

    Fast-swimming hydromedusan jellyfish possess a characteristic funnel-shaped velum at the exit of their oral cavity that interacts with the pulsed jets of water ejected during swimming motions. It has been previously assumed that the velum primarily serves to augment swimming thrust by constricting the ejected flow in order to produce higher jet velocities. This paper presents high-speed video and dye-flow visualizations of free-swimming Nemopsis bachei hydromedusae, which instead indicate tha...

  13. Regeneration in Swimming

    OpenAIRE

    Lehocký, Jan

    2006-01-01

    Topic: Regeneration in the swimming Aim: Using a questionnaire to find out information and views on the need of regeneration and its use. Process the results and evaluate the survey data into synoptic tables and graphs. Giving a comprehensive overview of the field of regeneration in the swimming sport. Method: The research group of our work happened 30 swimmers - participants Championship Czech Republic 2005 in short swimming pool at the age of 15-33 years. Results: It was confirmed that most...

  14. Nutritional recommendations for synchronized swimming.

    Science.gov (United States)

    Robertson, Sherry; Benardot, Dan; Mountjoy, Margo

    2014-08-01

    The sport of synchronized swimming is unique, because it combines speed, power, and endurance with precise synchronized movements and high-risk acrobatic maneuvers. Athletes must train and compete while spending a great amount of time underwater, upside down, and without the luxury of easily available oxygen. This review assesses the scientific evidence with respect to the physiological demands, energy expenditure, and body composition in these athletes. The role of appropriate energy requirements and guidelines for carbohydrate, protein, fat, and micronutrients for elite synchronized swimmers are reviewed. Because of the aesthetic nature of the sport, which prioritizes leanness, the risks of energy and macronutrient deficiencies are of significant concern. Relative Energy Deficiency in Sport and disordered eating/eating disorders are also of concern for these female athletes. An approach to the healthy management of body composition in synchronized swimming is outlined. Synchronized swimmers should be encouraged to consume a well-balanced diet with sufficient energy to meet demands and to time the intake of carbohydrate, protein, and fat to optimize performance and body composition. Micronutrients of concern for this female athlete population include iron, calcium, and vitamin D. This article reviews the physiological demands of synchronized swimming and makes nutritional recommendations for recovery, training, and competition to help optimize athletic performance and to reduce risks for weight-related medical issues that are of particular concern for elite synchronized swimmers.

  15. [Swimming performance in the aged].

    Science.gov (United States)

    Letzelter, M; Jungermann, C; Freitag, W

    1986-01-01

    The deterioration of performance caused by aging was examined in 3,469 swimmers divided into 9 age groups and 4 styles of swimming. Comparisons using cross and longitudinal sections show that older swimmers become progressively slower, and the reduction of speed in all styles of swimming follows a quadratic trend. The losses of efficiency increase with age group, being by far the most in back-stroke and the least in crawl swimming. The combined longitudinal and cross sectional comparisons confirm this result, but not without any exception, for very often no statistically significant differences could be recognized between adjacent age groups. The interindividual comparison shows that it is also possible to maintain or even improve the efficiency over 10 to 12 years, even in the fifth or sixth decade of age, if the intensity and volume of training can be increased. The curve comprising reductions in the later stages of life may additionally be caused by the smaller number of persons per group and the deficient homogeneity within these groups. In addition to this, the tendency towards higher losses in older age groups is not significant, if only the best competitors of each age group are compared.

  16. Swimming behavior and prey retention of the polychaete larvae Polydora ciliata (Johnston)

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Jacobsen, Hans Henrik; Andersen, Anders

    2010-01-01

    The behavior of the ubiquitous estuarine planktotrophic spionid polychaete larvae Polydora ciliata was studied. We describe ontogenetic changes in morphology, swimming speed and feeding rates and have developed a simple swimming model using low Reynolds number hydrodynamics. In the model we assumed...... that the ciliary swimming apparatus is primarily composed of the prototroch and secondarily by the telotroch. The model predicted swimming speeds and feeding rates that corresponded well with the measured speeds and rates. Applying empirical data to the model, we were able to explain the profound decrease...... in specific feeding rates and the observed increase in the difference between upward and downward swimming speeds with larval size. We estimated a critical larval length above which the buoyancy-corrected weight of the larva exceeds the propulsion force generated by the ciliary swimming apparatus and thus...

  17. The effect of external dummy transmitters on oxygen consumption and performance of swimming Atlantic cod

    DEFF Research Database (Denmark)

    Steinhausen, M.F.; Andersen, Niels Gerner; Steffensen, J.F.

    2006-01-01

    Decreased critical swimming speed and increased oxygen consumption (Mo-2) was found for externally tagged Atlantic cod Gadus morhua swimming at a high speed of 0 center dot 9 body length (total length, L-Gamma) s(-1). No difference was found in the standard metabolic rate, indicating...

  18. Spatial organization and Synchronization in collective swimming of Hemigrammus bleheri

    Science.gov (United States)

    Ashraf, Intesaaf; Ha, Thanh-Tung; Godoy-Diana, Ramiro; Thiria, Benjamin; Halloy, Jose; Collignon, Bertrand; Laboratoire de Physique et Mécanique des Milieux Hétérogènes (PMMH) Team; Laboratoire Interdisciplinaire des Energies de Demain (LIED) Team

    2016-11-01

    In this work, we study the collective swimming of Hemigrammus bleheri fish using experiments in a shallow swimming channel. We use high-speed video recordings to track the midline kinematics and the spatial organization of fish pairs and triads. Synchronizations are characterized by observance of "out of phase" and "in phase" configurations. We show that the synchronization state is highly correlated to swimming speed. The increase in synchronization led to efficient swimming based on Strouhal number. In case of fish pairs, the collective swimming is 2D and the spatial organization is characterized by two characteristic lengths: the lateral and longitudinal separation distances between fish pairs.For fish triads, different swimming patterns or configurations are observed having three dimensional structures. We performed 3D kinematic analysis by employing 3D reconstruction using the Direct Linear Transformation (DLT). We show that fish still keep their nearest neighbor distance (NND) constant irrespective of swimming speeds and configuration. We also point out characteristic angles between neighbors, hence imposing preferred patterns. At last we will give some perspectives on spatial organization for larger population. Sorbonne Paris City College of Doctoral Schools. European Union Information and Communication Technologies project ASSISIbf, FP7-ICT-FET-601074.

  19. Kinematics of swimming and thrust production during powerstroking bouts of the swim frenzy in green turtle hatchlings.

    Science.gov (United States)

    Booth, David T

    2014-09-04

    Hatchling sea turtles emerge from nests, crawl down the beach and enter the sea where they typically enter a stereotypical hyperactive swimming frenzy. During this swim the front flippers are moved up and down in a flapping motion and are the primary source of thrust production. I used high-speed video linked with simultaneous measurement of thrust production in tethered hatchlings, along with high-speed video of free swimming hatchlings swimming at different water speeds in a swim flume to investigate the links between kinematics of front flipper movement, thrust production and swimming speed. In particular I tested the hypotheses that (1) increased swimming speed is achieved through an increased stroke rate; (2) force produced per stroke is proportional to stroke amplitude, (3) that forward thrust is produced during both the down and up phases of stroking; and (4) that peak thrust is produced towards the end of the downstroke cycle. Front flipper stroke rate was independent of water speed refuting the hypothesis that swimming speed is increased by increasing stroke rate. Instead differences in swimming speed were caused by a combination of varying flipper amplitude and the proportion of time spent powerstroking. Peak thrust produced per stroke varied within and between bouts of powerstroking, and these peaks in thrust were correlated with both flipper amplitude and flipper angular momentum during the downstroke supporting the hypothesis that stroke force is a function of stroke amplitude. Two distinct thrust production patterns were identified, monophasic in which a single peak in thrust was recorded during the later stages of the downstroke, and biphasic in which a small peak in thrust was recorded at the very end of the upstroke and this followed by a large peak in thrust during the later stages of the downstroke. The biphasic cycle occurs in ∼20% of hatchlings when they first started swimming, but disappeared after one to two hours of swimming. The

  20. Kinematics of swimming and thrust production during powerstroking bouts of the swim frenzy in green turtle hatchlings

    Directory of Open Access Journals (Sweden)

    David T. Booth

    2014-09-01

    Full Text Available Hatchling sea turtles emerge from nests, crawl down the beach and enter the sea where they typically enter a stereotypical hyperactive swimming frenzy. During this swim the front flippers are moved up and down in a flapping motion and are the primary source of thrust production. I used high-speed video linked with simultaneous measurement of thrust production in tethered hatchlings, along with high-speed video of free swimming hatchlings swimming at different water speeds in a swim flume to investigate the links between kinematics of front flipper movement, thrust production and swimming speed. In particular I tested the hypotheses that (1 increased swimming speed is achieved through an increased stroke rate; (2 force produced per stroke is proportional to stroke amplitude, (3 that forward thrust is produced during both the down and up phases of stroking; and (4 that peak thrust is produced towards the end of the downstroke cycle. Front flipper stroke rate was independent of water speed refuting the hypothesis that swimming speed is increased by increasing stroke rate. Instead differences in swimming speed were caused by a combination of varying flipper amplitude and the proportion of time spent powerstroking. Peak thrust produced per stroke varied within and between bouts of powerstroking, and these peaks in thrust were correlated with both flipper amplitude and flipper angular momentum during the downstroke supporting the hypothesis that stroke force is a function of stroke amplitude. Two distinct thrust production patterns were identified, monophasic in which a single peak in thrust was recorded during the later stages of the downstroke, and biphasic in which a small peak in thrust was recorded at the very end of the upstroke and this followed by a large peak in thrust during the later stages of the downstroke. The biphasic cycle occurs in ∼20% of hatchlings when they first started swimming, but disappeared after one to two hours of

  1. The swimming mechanics of Artemia Salina

    Science.gov (United States)

    Ruiz-Angulo, A.; Ramos-Musalem, A. K.; Zenit, R.

    2013-11-01

    An experimental study to analyze the swimming strategy of a small crustacean (Artemia Salina) was conducted. This animal has a series of eleven pairs of paddle-like appendices in its thorax. These legs move in metachronal-wave fashion to achieve locomotion. To quantify the swimming performance, both high speed video recordings of the legs motion and time-resolved PIV measurements of the induced propulsive jet were conducted. Experiments were conducted for both tethered and freely swimming specimens. We found that despite their small size, the propulsion is achieved by an inertial mechanism. An analysis of the efficiency of the leg wave-like motion is presented and discussed. A brief discussion on the mixing capability of the induced flow is also presented.

  2. The swimming activity of the staggerer mutant mouse.

    Science.gov (United States)

    Goodall, G; Guastavino, J M; Gheusi, G

    1986-09-01

    Four experiments investigated the swimming behaviour of staggerer mutant mice. The results partially confirmed previous reports that a mouse's swimming is unaffected by the staggerer mutation. In terms of speed and distance there are indeed no measurable differences between normal and staggerer mice, when first placed in the water. The stagger's resistance was however shown to be much lower than a normal's and the genetic difference was also associated with different styles of swimming. Furthermore, whereas the normal mouse's swimming behaviour evolves with increased time in the water, the staggerer's remains constant. The differences are interpreted on the basis of abnormal novelty reactions by the staggerer mutants. Thus, swimming appears to be a better tool for investigating the higher-level cognitive functions of this mutant than terrestrial locomotion. Copyright © 1986. Published by Elsevier B.V.

  3. Swimming pool granuloma

    Science.gov (United States)

    Aquarium granuloma; Fish tank granuloma; Mycobacterium marinum infection ... A swimming pool granuloma occurs when water containing Mycobacterium marinum bacteria enter a break in the skin. Signs of a skin infection appear ...

  4. Diarrhea and Swimming

    Science.gov (United States)

    ... Externa) "Swimmer's Ear" (Otitis Externa) Prevention Head Lice MRSA Pinworm & Swimming Other Recreational Water-related Issues Pools & ... Professionals Aquatics Staff Travelers En Español Publications, Data, & Statistics Disease & Outbreak Tracking Prevention Commentaries Diarrhea & Vomiting Skin, ...

  5. Critical stroke rate as a parameter for evaluation in swimming

    Directory of Open Access Journals (Sweden)

    Marcos Franken

    2013-12-01

    Full Text Available The purpose of this study was to investigate the critical stroke rate (CSR compared to the average stroke rate (SR when swimming at the critical speed (CS. Ten competitive swimmers performed five 200 m trials at different velocities relative to their CS (90, 95, 100, 103 and 105% in front crawl. The CSR was significantly higher than the SR at 90% of the CS and lower at 105% of the CS. Stroke length (SL at 103 and 105% of the CS were lower than the SL at 90, 95, and 100% of the CS. The combination of the CS and CSR concepts can be useful for improving both aerobic capacity/power and technique. CS and CSR could be used to reduce the SR and increase the SL, when swimming at the CS pace, or to increase the swimming speed when swimming at the CSR.

  6. Laryngoscopy during swimming

    DEFF Research Database (Denmark)

    Walsted, Emil S; Swanton, Laura L; van van Someren, Ken

    2017-01-01

    Exercise-induced laryngeal obstruction (EILO) is a key differential diagnosis for respiratory symptoms in athletes and is particularly prevalent in aquatic athletes. A definitive diagnosis of EILO is dependent on laryngoscopy, performed continuously, while an athlete engages in the sport...... that precipitates their symptoms. This report provides the first description of the feasibility of performing continuous laryngoscopy during exercise in a swimming environment. The report describes the methodology and safety of the use of continuous laryngoscopy while swimming. Laryngoscope, 2017....

  7. Swimming efficiency in a shear-thinning fluid

    Science.gov (United States)

    Nganguia, Herve; Pietrzyk, Kyle; Pak, On Shun

    2017-12-01

    Micro-organisms expend energy moving through complex media. While propulsion speed is an important property of locomotion, efficiency is another factor that may determine the swimming gait adopted by a micro-organism in order to locomote in an energetically favorable manner. The efficiency of swimming in a Newtonian fluid is well characterized for different biological and artificial swimmers. However, these swimmers often encounter biological fluids displaying shear-thinning viscosities. Little is known about how this nonlinear rheology influences the efficiency of locomotion. Does the shear-thinning rheology render swimming more efficient or less? How does the swimming efficiency depend on the propulsion mechanism of a swimmer and rheological properties of the surrounding shear-thinning fluid? In this work, we address these fundamental questions on the efficiency of locomotion in a shear-thinning fluid by considering the squirmer model as a general locomotion model to represent different types of swimmers. Our analysis reveals how the choice of surface velocity distribution on a squirmer may reduce or enhance the swimming efficiency. We determine optimal shear rates at which the swimming efficiency can be substantially enhanced compared with the Newtonian case. The nontrivial variations of swimming efficiency prompt questions on how micro-organisms may tune their swimming gaits to exploit the shear-thinning rheology. The findings also provide insights into how artificial swimmers should be designed to move through complex media efficiently.

  8. Sex-related differences and age of peak performance in breaststroke versus freestyle swimming.

    Science.gov (United States)

    Wolfrum, Mathias; Knechtle, Beat; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2013-12-19

    Sex-related differences in performance and in age of peak performance have been reported for freestyle swimming. However, little is known about the sex-related differences in other swimming styles. The aim of the present study was to compare performance and age of peak performance for elite men and women swimmers in breaststroke versus freestyle. Race results were analyzed for swimmers at national ranked in the Swiss high score list (during 2006 through 2010) and for international swimmers who qualified for the finals of the FINA World Swimming Championships (during 2003 through 2011). The sex-related difference in swimming speed was significantly greater for freestyle than for breaststroke over 50 m, 100 m, and 200 m race distances for Swiss swimmers, but not for FINA finalists. The sex-related difference for both freestyle and breaststroke swimming speeds decreased significantly with increasing swimming distance for both groups. Race distance did not affect the age of peak performance by women in breaststroke, but age of peak performance was four years older for FINA women than for Swiss women. Men achieved peak swimming performance in breaststroke at younger ages for longer race distances, and the age of peak swimming performance was six years older for FINA men than for Swiss men. In freestyle swimming, race distance did not affect the age of peak swimming performance for Swiss women, but the age of peak swimming performance decreased with increasing race distance for Swiss men and for both sexes at the FINA World Championships. Results of the present study indicate that (i) sex-related differences in swimming speed were greater for freestyle than for breaststroke for swimmers at national level, but not for swimmers at international level, and (ii) both female and male swimmers achieved peak swimming speeds at younger ages in breaststroke than in freestyle. Further studies are required to better understand differences between trends at national and

  9. A coin vibrational motor swimming at low Reynolds number

    CERN Document Server

    Quillen, Alice C; Kelley, Douglas H; Friedmann, Tamar; Oakes, Patrick W

    2016-01-01

    Low-cost coin vibrational motors, used in haptic feedback, exhibit rotational internal motion inside a rigid case. Because the motor case motion exhibits rotational symmetry, when placed into a fluid such as glycerin, the motor does not swim even though its vibrations induce steady streaming in the fluid. However, a piece of rubber foam stuck to the curved case and giving the motor neutral buoyancy also breaks the rotational symmetry allowing it to swim. We measured a 1 cm diameter coin vibrational motor swimming in glycerin at a speed of a body length in 3 seconds or at 3 mm/s. The swim speed puts the vibrational motor in a low Reynolds number regime similar to bacterial motility, but because of the vibration it is not analogous to biological organisms. Rather the swimming vibrational motor may inspire small inexpensive robotic swimmers that are robust as they contain no external moving parts. A time dependent Stokes equation planar sheet model suggests that the swim speed depends on a steady streaming veloc...

  10. Critical evaluation of oxygen-uptake assessment in swimming.

    Science.gov (United States)

    Sousa, Ana; Figueiredo, Pedro; Pendergast, David; Kjendlie, Per-Ludvik; Vilas-Boas, João P; Fernandes, Ricardo J

    2014-03-01

    Swimming has become an important area of sport science research since the 1970s, with the bioenergetic factors assuming a fundamental performance-influencing role. The purpose of this study was to conduct a critical evaluation of the literature concerning oxygen-uptake (VO2) assessment in swimming, by describing the equipment and methods used and emphasizing the recent works conducted in ecological conditions. Particularly in swimming, due to the inherent technical constraints imposed by swimming in a water environment, assessment of VO2max was not accomplished until the 1960s. Later, the development of automated portable measurement devices allowed VO2max to be assessed more easily, even in ecological swimming conditions, but few studies have been conducted in swimming-pool conditions with portable breath-by-breath telemetric systems. An inverse relationship exists between the velocity corresponding to VO2max and the time a swimmer can sustain it at this velocity. The energy cost of swimming varies according to its association with velocity variability. As, in the end, the supply of oxygen (whose limitation may be due to central-O2 delivery and transportation to the working muscles-or peripheral factors-O2 diffusion and utilization in the muscles) is one of the critical factors that determine swimming performance, VO2 kinetics and its maximal values are critical in understanding swimmers' behavior in competition and to develop efficient training programs.

  11. Pop up satellite tags impair swimming performance and energetics of the European eel (Anguilla anguilla.

    Directory of Open Access Journals (Sweden)

    Caroline Methling

    Full Text Available Pop-up satellite archival tags (PSATs have recently been applied in attempts to follow the oceanic spawning migration of the European eel. PSATs are quite large, and in all likelihood their hydraulic drag constitutes an additional cost during swimming, which remains to be quantified, as does the potential implication for successful migration. Silver eels (L(T = 598.6±29 mm SD, N = 9 were subjected to swimming trials in a Steffensen-type swim tunnel at increasing speeds of 0.3-0.9 body lengths s(-1, first without and subsequently with, a scaled down PSAT dummy attached. The tag significantly increased oxygen consumption (MO(2 during swimming and elevated minimum cost of transport (COT(min by 26%. Standard (SMR and active metabolic rate (AMR as well as metabolic scope remained unaffected, suggesting that the observed effects were caused by increased drag. Optimal swimming speed (U(opt was unchanged, whereas critical swimming speed (U(crit decreased significantly. Swimming with a PSAT altered swimming kinematics as verified by significant changes to tail beat frequency (f, body wave speed (v and Strouhal number (St. The results demonstrate that energy expenditure, swimming performance and efficiency all are significantly affected in migrating eels with external tags.

  12. Pop up satellite tags impair swimming performance and energetics of the European eel (Anguilla anguilla).

    Science.gov (United States)

    Methling, Caroline; Tudorache, Christian; Skov, Peter V; Steffensen, John F

    2011-01-01

    Pop-up satellite archival tags (PSATs) have recently been applied in attempts to follow the oceanic spawning migration of the European eel. PSATs are quite large, and in all likelihood their hydraulic drag constitutes an additional cost during swimming, which remains to be quantified, as does the potential implication for successful migration. Silver eels (L(T) = 598.6±29 mm SD, N = 9) were subjected to swimming trials in a Steffensen-type swim tunnel at increasing speeds of 0.3-0.9 body lengths s(-1), first without and subsequently with, a scaled down PSAT dummy attached. The tag significantly increased oxygen consumption (MO(2)) during swimming and elevated minimum cost of transport (COT(min)) by 26%. Standard (SMR) and active metabolic rate (AMR) as well as metabolic scope remained unaffected, suggesting that the observed effects were caused by increased drag. Optimal swimming speed (U(opt)) was unchanged, whereas critical swimming speed (U(crit)) decreased significantly. Swimming with a PSAT altered swimming kinematics as verified by significant changes to tail beat frequency (f), body wave speed (v) and Strouhal number (St). The results demonstrate that energy expenditure, swimming performance and efficiency all are significantly affected in migrating eels with external tags.

  13. Kinematical changes in swimming front Crawl and Breaststroke with the AquaTrainer snorkel.

    Science.gov (United States)

    Barbosa, Tiago; Silva, António José; Reis, António Malvas; Costa, Mário; Garrido, Nuno; Policarpo, Fernando; Reis, Victor Machado

    2010-08-01

    The aim of the present study was to assess the kinematical changes when swimming maximal bouts in Front Crawl and Breaststroke with the AquaTrainer snorkel. Thirteen male swimmers (7 at Breaststroke and 6 at Front Crawl) of national level performed randomly two maximal bouts of 100-m swims: one bout using the AquaTrainer snorkel (snorkel swim) and another one without the snorkel (free swim). The swims were videotaped in sagittal plane with a pair of cameras providing 2D kinematics evaluation. The following measures were assessed: swimming performance (T100), stroke cycle period (P), stroke rate (SR), stroke length (SL), swimming velocity (v), swimming efficiency as estimated by the stroke index (SI), speed fluctuation (dv) and the mathematical characterisation of dv. T100 was significantly higher when swimming with the snorkel than in free swimming at Breaststroke (Delta = 6.26%) and at Front Crawl (Delta = 4.75%). P, SR and SL, as well as SI and dv did not present significant differences. The main finding of the study was that changes in the swimming velocity imposed by the use of the Aquatrainer do not seem due to changes in general kinematics or swimming efficiency.

  14. Use of chiral cell shape to ensure highly directional swimming in trypanosomes.

    Science.gov (United States)

    Wheeler, Richard John

    2017-01-01

    Swimming cells typically move along a helical path or undergo longitudinal rotation as they swim, arising from chiral asymmetry in hydrodynamic drag or propulsion bending the swimming path into a helix. Helical paths are beneficial for some forms of chemotaxis, but why asymmetric shape is so prevalent when a symmetric shape would also allow highly directional swimming is unclear. Here, I analyse the swimming of the insect life cycle stages of two human parasites; Trypanosoma brucei and Leishmania mexicana. This showed quantitatively how chirality in T. brucei cell shape confers highly directional swimming. High speed videomicrographs showed that T. brucei, L. mexicana and a T. brucei RNAi morphology mutant have a range of shape asymmetries, from wild-type T. brucei (highly chiral) to L. mexicana (near-axial symmetry). The chiral cells underwent longitudinal rotation while swimming, with more rapid longitudinal rotation correlating with swimming path directionality. Simulation indicated hydrodynamic drag on the chiral cell shape caused rotation, and the predicted geometry of the resulting swimming path matched the directionality of the observed swimming paths. This simulation of swimming path geometry showed that highly chiral cell shape is a robust mechanism through which microscale swimmers can achieve highly directional swimming at low Reynolds number. It is insensitive to random variation in shape or propulsion (biological noise). Highly symmetric cell shape can give highly directional swimming but is at risk of giving futile circular swimming paths in the presence of biological noise. This suggests the chiral T. brucei cell shape (associated with the lateral attachment of the flagellum) may be an adaptation associated with the bloodstream-inhabiting lifestyle of this parasite for robust highly directional swimming. It also provides a plausible general explanation for why swimming cells tend to have strong asymmetries in cell shape or propulsion.

  15. Use of chiral cell shape to ensure highly directional swimming in trypanosomes.

    Directory of Open Access Journals (Sweden)

    Richard John Wheeler

    2017-01-01

    Full Text Available Swimming cells typically move along a helical path or undergo longitudinal rotation as they swim, arising from chiral asymmetry in hydrodynamic drag or propulsion bending the swimming path into a helix. Helical paths are beneficial for some forms of chemotaxis, but why asymmetric shape is so prevalent when a symmetric shape would also allow highly directional swimming is unclear. Here, I analyse the swimming of the insect life cycle stages of two human parasites; Trypanosoma brucei and Leishmania mexicana. This showed quantitatively how chirality in T. brucei cell shape confers highly directional swimming. High speed videomicrographs showed that T. brucei, L. mexicana and a T. brucei RNAi morphology mutant have a range of shape asymmetries, from wild-type T. brucei (highly chiral to L. mexicana (near-axial symmetry. The chiral cells underwent longitudinal rotation while swimming, with more rapid longitudinal rotation correlating with swimming path directionality. Simulation indicated hydrodynamic drag on the chiral cell shape caused rotation, and the predicted geometry of the resulting swimming path matched the directionality of the observed swimming paths. This simulation of swimming path geometry showed that highly chiral cell shape is a robust mechanism through which microscale swimmers can achieve highly directional swimming at low Reynolds number. It is insensitive to random variation in shape or propulsion (biological noise. Highly symmetric cell shape can give highly directional swimming but is at risk of giving futile circular swimming paths in the presence of biological noise. This suggests the chiral T. brucei cell shape (associated with the lateral attachment of the flagellum may be an adaptation associated with the bloodstream-inhabiting lifestyle of this parasite for robust highly directional swimming. It also provides a plausible general explanation for why swimming cells tend to have strong asymmetries in cell shape or propulsion.

  16. Geneva 24 Hours Swim

    CERN Multimedia

    2003-01-01

    The 18th edition of the Geneva 24 hours swim competition will take place at the Vernets Swimming Pool on the 4th and 5th of October. More information and the results of previous years are given at: http://www.carouge-natation.com/24_heures/home_24_heures.htm Last year, CERN obtained first position in the inter-company category with a total of 152.3 kms swam by 45 participants. We are counting on your support to repeat this excellent performance this year. For those who would like to train, the Livron swimming pool in Meyrin is open as from Monday the 8th September. For further information please do not hesitate to contact us. Gino de Bilio and Catherine Delamare

  17. Geneva 24 hours swim

    CERN Multimedia

    2003-01-01

    The 18th edition of the Geneva 24 hours swim competition will take place at the Vernets Swimming Pool on the 4th and 5th of October. More information and the results of previous years are given at: http://www.carouge-natation.com/24_heures/home_24_heures.htm Last year, CERN obtained first position in the inter-company category with a total of 152.3 kms swam by 45 participants. We are counting on your support to repeat this excellent performance this year. For those who would like to train, the Livron swimming pool in Meyrin is open as from Monday the 8th September. For further information please do not hesitate to contact us. Gino de Bilio and Catherine Delamare

  18. Swimming intensity during triathlon: a review of current research and strategies to enhance race performance.

    Science.gov (United States)

    Peeling, Peter; Landers, Grant

    2009-08-01

    The swim section of Sprint- and Olympic-distance triathlon race formats is integral to the success of subsequent cycle and running disciplines, and to overall race performance. The current body of swimming-based triathlon research suggests that the energy used, and the positioning gained among competitors during the swim, is important in determining the success of an athlete's race, especially professional athletes in draft-legal settings. Furthermore, by swimming at a reduced intensity, it has been shown that the performance of the subsequent disciplines may be enhanced. However, reductions in energy output can be obtained without compromising swimming speed. This review highlights the importance of swimming intensity during a triathlon and how it impacts on the ensuing cycle and run. Furthermore, consideration is given to current methods used to manipulate swimming performance.

  19. Establishing Zebrafish as a Novel Exercise Model: Swimming Economy, Swimming-Enhanced Growth and Muscle Growth Marker Gene Expression

    Science.gov (United States)

    Rovira, Mireia; Brittijn, Sebastiaan A.; Burgerhout, Erik; van den Thillart, Guido E. E. J. M.; Spaink, Herman P.; Planas, Josep V.

    2010-01-01

    Background Zebrafish has been largely accepted as a vertebrate multidisciplinary model but its usefulness as a model for exercise physiology has been hampered by the scarce knowledge on its swimming economy, optimal swimming speeds and cost of transport. Therefore, we have performed individual and group-wise swimming experiments to quantify swimming economy and to demonstrate the exercise effects on growth in adult zebrafish. Methodology/Principal Findings Individual zebrafish (n = 10) were able to swim at a critical swimming speed (Ucrit) of 0.548±0.007 m s−1 or 18.0 standard body lengths (BL) s−1. The optimal swimming speed (Uopt) at which energetic efficiency is highest was 0.396±0.019 m s−1 (13.0 BL s−1) corresponding to 72.26±0.29% of Ucrit. The cost of transport at optimal swimming speed (COTopt) was 25.23±4.03 µmol g−1 m−1. A group-wise experiment was conducted with zebrafish (n = 83) swimming at Uopt for 6 h day−1 for 5 days week−1 for 4 weeks vs. zebrafish (n = 84) that rested during this period. Swimming zebrafish increased their total body length by 5.6% and body weight by 41.1% as compared to resting fish. For the first time, a highly significant exercise-induced growth is demonstrated in adult zebrafish. Expression analysis of a set of muscle growth marker genes revealed clear regulatory roles in relation to swimming-enhanced growth for genes such as growth hormone receptor b (ghrb), insulin-like growth factor 1 receptor a (igf1ra), troponin C (stnnc), slow myosin heavy chain 1 (smyhc1), troponin I2 (tnni2), myosin heavy polypeptide 2 (myhz2) and myostatin (mstnb). Conclusions/Significance From the results of our study we can conclude that zebrafish can be used as an exercise model for enhanced growth, with implications in basic, biomedical and applied sciences, such as aquaculture. PMID:21217817

  20. Establishing zebrafish as a novel exercise model: swimming economy, swimming-enhanced growth and muscle growth marker gene expression.

    Directory of Open Access Journals (Sweden)

    Arjan P Palstra

    Full Text Available BACKGROUND: Zebrafish has been largely accepted as a vertebrate multidisciplinary model but its usefulness as a model for exercise physiology has been hampered by the scarce knowledge on its swimming economy, optimal swimming speeds and cost of transport. Therefore, we have performed individual and group-wise swimming experiments to quantify swimming economy and to demonstrate the exercise effects on growth in adult zebrafish. METHODOLOGY/PRINCIPAL FINDINGS: Individual zebrafish (n = 10 were able to swim at a critical swimming speed (U(crit of 0.548±0.007 m s(-1 or 18.0 standard body lengths (BL s(-1. The optimal swimming speed (U(opt at which energetic efficiency is highest was 0.396±0.019 m s(-1 (13.0 BL s(-1 corresponding to 72.26±0.29% of U(crit. The cost of transport at optimal swimming speed (COT(opt was 25.23±4.03 µmol g(-1 m(-1. A group-wise experiment was conducted with zebrafish (n = 83 swimming at U(opt for 6 h day(-1 for 5 days week(-1 for 4 weeks vs. zebrafish (n = 84 that rested during this period. Swimming zebrafish increased their total body length by 5.6% and body weight by 41.1% as compared to resting fish. For the first time, a highly significant exercise-induced growth is demonstrated in adult zebrafish. Expression analysis of a set of muscle growth marker genes revealed clear regulatory roles in relation to swimming-enhanced growth for genes such as growth hormone receptor b (ghrb, insulin-like growth factor 1 receptor a (igf1ra, troponin C (stnnc, slow myosin heavy chain 1 (smyhc1, troponin I2 (tnni2, myosin heavy polypeptide 2 (myhz2 and myostatin (mstnb. CONCLUSIONS/SIGNIFICANCE: From the results of our study we can conclude that zebrafish can be used as an exercise model for enhanced growth, with implications in basic, biomedical and applied sciences, such as aquaculture.

  1. Healthy Swimming/Recreational Water

    Science.gov (United States)

    ... Tub/Spa Test Strips Inflatable & Plastic Kiddie Pools Water Play Areas & Interactive Fountains Swim Diapers & Swim Pants Breastfeeding in Pools & Hot Tubs/Spas Recreational Water Illnesses Diarrheal Illness Rashes Ear Infections Respiratory Infections ...

  2. 2008 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  3. 2010 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  4. Swimming Pools and Molluscum Contagiosum

    Science.gov (United States)

    ... Travelers’ Health: Smallpox & Other Orthopoxvirus-Associated Infections Poxvirus Swimming Pools Recommend on Facebook Tweet Share Compartir The ... often ask if molluscum virus can spread in swimming pools. There is also concern that it can ...

  5. 2009 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  6. 2007 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  7. 2006 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  8. Are fish less responsive to a flow stimulus when swimming?

    Science.gov (United States)

    Feitl, Karla E; Ngo, Victoria; McHenry, Matthew J

    2010-09-15

    Fish use the lateral line system to sense the water flow created by a predator's strike. Despite its potential importance to the survival of a diversity of species, it is unclear whether this ability becomes compromised when a fish swims. Therefore, the present study compared the behavioral responsiveness of swimming and motionless zebrafish (Danio rerio) larvae when exposed to the flow of a suction-feeding predator. This flow was generated with an impulse chamber, which is a device that we developed to generate a repeatable stimulus with a computer-controlled servo motor. Using high-speed video recordings, we found that about three-quarters (0.76, N=121) of motionless larvae responded to the stimulus with an escape response. These larvae were 66% more likely to respond to flow directed perpendicular than flow running parallel to the body. Swimming larvae exhibited a 0.40 response probability and were therefore nearly half as likely to respond to flow as motionless larvae. However, the latency between stimulus and response was unaffected by swimming or the direction of flow. Therefore, swimming creates changes in the hydrodynamics or neurophysiology of a larval fish that diminish the probability, but not the speed, of their response to a flow stimulus. These findings demonstrate a sensory benefit to the intermittent swimming behavior observed among a broad diversity of fishes.

  9. Swimming of a Tiny Subtropical Sea Butterfly with Coiled Shell

    Science.gov (United States)

    Murphy, David; Karakas, Ferhat; Maas, Amy

    2017-11-01

    Sea butterflies, also known as pteropods, include a variety of small, zooplanktonic marine snails. Thecosomatous pteropods possess a shell and swim at low Reynolds numbers by beating their wing-like parapodia in a manner reminiscent of insect flight. In fact, previous studies of the pteropod Limacina helicina have shown that pteropod swimming hydrodynamics and tiny insect flight aerodynamics are dynamically similar. Studies of L. helicina swimming have been performed in polar (0 degrees C) and temperate conditions (12 degrees C). Here we present measurements of the swimming of Heliconoides inflatus, a smaller yet morphologically similar pteropod that lives in warm Bermuda seawater (21 degrees C) with a viscosity almost half that of the polar seawater. The collected H. inflatus have shell sizes less than 1.5 mm in diameter, beat their wings at frequencies up to 11 Hz, and swim upwards in sawtooth trajectories at speeds up to approximately 25 mm/s. Using three-dimensional wing and body kinematics collected with two orthogonal high speed cameras and time-resolved, 2D flow measurements collected with a micro-PIV system, we compare the effects of smaller body size and lower water viscosity on the flow physics underlying flapping-based swimming by pteropods and flight by tiny insects.

  10. Swimming of a Sea Butterfly with an Elongated Shell

    Science.gov (United States)

    Karakas, Ferhat; Maas, Amy E.; Murphy, David W.

    2017-11-01

    Sea butterflies (pteropods) are small, zooplanktonic marine snails which swim by flapping highly flexible parapodia. Previous studies show that the swimming hydrodynamics of Limacina helicina, a polar pteropod with a spiraled shell, is similar to tiny insect flight aerodynamics and that forward-backward pitching is key for lift generation. However, swimming by diverse pteropod species with different shell shapes has not been examined. We present measurements of the swimming of Cuvierina columnella, a warm water species with an elongated non-spiraled shell collected off the coast of Bermuda. With a body length of 9 mm, wing beat frequency of 4-6 Hz and swimming speed of 35 mm/s, these organisms swim at a Reynolds number of approximately 300, larger than that of L. helicina. High speed 3D kinematics acquired via two orthogonal cameras reveals that the elongated shell correlates with reduced body pitching and that the wings bend approximately 180 degrees in each direction, overlapping at the end of each half-stroke. Time resolved 2D flow measurements collected with a micro-PIV system reveal leading edge vortices present in both power and recovery strokes. Interactions between the overlapping wings and the shell also likely play a role in lift generation.

  11. Turtle mimetic soft robot with two swimming gaits.

    Science.gov (United States)

    Song, Sung-Hyuk; Kim, Min-Soo; Rodrigue, Hugo; Lee, Jang-Yeob; Shim, Jae-Eul; Kim, Min-Cheol; Chu, Won-Shik; Ahn, Sung-Hoon

    2016-05-04

    This paper presents a biomimetic turtle flipper actuator consisting of a shape memory alloy composite structure for implementation in a turtle-inspired autonomous underwater vehicle. Based on the analysis of the Chelonia mydas, the flipper actuator was divided into three segments containing a scaffold structure fabricated using a 3D printer. According to the filament stacking sequence of the scaffold structure in the actuator, different actuating motions can be realized and three different types of scaffold structures were proposed to replicate the motion of the different segments of the flipper of the Chelonia mydas. This flipper actuator can mimic the continuous deformation of the forelimb of Chelonia mydas which could not be realized in previous motor based robot. This actuator can also produce two distinct motions that correspond to the two different swimming gaits of the Chelonia mydas, which are the routine and vigorous swimming gaits, by changing the applied current sequence of the SMA wires embedded in the flipper actuator. The generated thrust and the swimming efficiency in each swimming gait of the flipper actuator were measured and the results show that the vigorous gait has a higher thrust but a relatively lower swimming efficiency than the routine gait. The flipper actuator was implemented in a biomimetic turtle robot, and its average swimming speed in the routine and vigorous gaits were measured with the vigorous gait being capable of reaching a maximum speed of 11.5 mm s(-1).

  12. Changes in breaststroke swimming performances in national and international athletes competing between 1994 and 2011 -a comparison with freestyle swimming performances.

    Science.gov (United States)

    Wolfrum, Mathias; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald; Knechtle, Beat

    2014-01-01

    The purpose of the present study was to analyse potential changes in performance of elite breaststroke swimmers competing at national and international level and to compare to elite freestyle swimming performance. Temporal trends in performance of elite breaststroke swimmers were analysed from records of the Swiss Swimming Federation and the FINA (Fédération Internationale de Natation) World Swimming Championships during the 1994-2011 period. Swimming speeds of elite female and male breaststroke swimmers competing in 50 m, 100 m, and 200 m were examined using linear regression, non-linear regression and analysis of variance. Results of breaststroke swimmers were compared to results of freestyle swimmers. Swimming speed in both strokes improved significantly (p < 0.0001-0.025) over time for both sexes, with the exception of 50 m breaststroke for FINA men. Sex differences in swimming speed increased significantly over time for Swiss freestyle swimmers (p < 0.0001), but not for FINA swimmers for freestyle, while the sex difference remained stable for Swiss and FINA breaststroke swimmers. The sex differences in swimming speed decreased significantly (p < 0.0001) with increasing race distance. The present study showed that elite male and female swimmers competing during the 1994-2011 period at national and international level improved their swimming speed in both breaststroke and freestyle. The sex difference in freestyle swimming speed consistently increased in athletes competing at national level, whereas it remained unchanged in athletes competing at international level. Future studies should investigate temporal trends for recent time in other strokes, to determine whether this improvement is a generalized phenomenon.

  13. Changes in breaststroke swimming performances in national and international athletes competing between 1994 and 2011 –a comparison with freestyle swimming performances

    Science.gov (United States)

    2014-01-01

    Background The purpose of the present study was to analyse potential changes in performance of elite breaststroke swimmers competing at national and international level and to compare to elite freestyle swimming performance. Methods Temporal trends in performance of elite breaststroke swimmers were analysed from records of the Swiss Swimming Federation and the FINA (Fédération Internationale de Natation) World Swimming Championships during the 1994–2011 period. Swimming speeds of elite female and male breaststroke swimmers competing in 50 m, 100 m, and 200 m were examined using linear regression, non-linear regression and analysis of variance. Results of breaststroke swimmers were compared to results of freestyle swimmers. Results Swimming speed in both strokes improved significantly (p < 0.0001-0.025) over time for both sexes, with the exception of 50 m breaststroke for FINA men. Sex differences in swimming speed increased significantly over time for Swiss freestyle swimmers (p < 0.0001), but not for FINA swimmers for freestyle, while the sex difference remained stable for Swiss and FINA breaststroke swimmers. The sex differences in swimming speed decreased significantly (p < 0.0001) with increasing race distance. Conclusions The present study showed that elite male and female swimmers competing during the 1994–2011 period at national and international level improved their swimming speed in both breaststroke and freestyle. The sex difference in freestyle swimming speed consistently increased in athletes competing at national level, whereas it remained unchanged in athletes competing at international level. Future studies should investigate temporal trends for recent time in other strokes, to determine whether this improvement is a generalized phenomenon. PMID:24826211

  14. Effects of intraspecific variation in reproductive traits, pectoral fin use and burst swimming on metabolic rates and swimming performance in the Trinidadian guppy (Poecilia reticulata)

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Banet, Amanda I.; Christensen, Rune Haubo Bojesen

    2013-01-01

    of reproductive traits, pectoral fin use and burse-assisted swimming on swimming metabolic rate, standard metabolic rate (MO2std) and prolonged swimming performance (Ucrit). Reproductive traits included reproductive allocation and pregnancy stage, the former defined as the mass of the reproductive tissues divided......There is considerable intraspecific variation in metabolic rates and locomotor performance in aquatic ectothermic vertebrates; however, the mechanistic basis remains poorly understood. Using pregnant Trinidadian guppies (Poecilia reticulata), a livebearing teleost, we examined the effects...... by the total body mass. Results showed that the metabolic rate increased curvilinearly with swimming speed. The slope of the relationship was used as an index of swimming cost. There was no evidence that reproductive traits correlated with swimming cost, MO2std or Ucrit. In contrast, data revealed strong...

  15. Effective propulsion in swimming : Grasping the hydrodynamics of hand and arm movements

    NARCIS (Netherlands)

    Van Houwelingen, Josje; Schreven, Sander; Smeets, Jeroen B J; Clercx, Herman J H; Beek, Peter J.

    2017-01-01

    In this paper, a literature review is presented regarding the hydrodynamic effects of different hand and arm movements during swimming with the aim to identify lacunae in current methods and knowledge, and to distil practical guidelines for coaches and swimmers seeking to increase swimming speed.

  16. Flow patterns of larval fish: undulatory swimming in the intermediate flow regime

    NARCIS (Netherlands)

    Müller, U.K.; Boogaart, van den J.G.M.; Leeuwen, van J.L.

    2008-01-01

    Fish larvae, like many adult fish, swim by undulating their body. However, their body size and swimming speeds put them in the intermediate flow regime, where viscous and inertial forces both play an important role in the interaction between fish and water. To study the influence of the relatively

  17. Effect of dissolved oxygen on swimming ability and physiological response to swimming fatigue of whiteleg shrimp (Litopenaeus vannamei)

    Science.gov (United States)

    Duan, Yan; Zhang, Xiumei; Liu, Xuxu; Thakur, Dhanrajsingh N.

    2013-11-01

    The swimming endurance of whiteleg shrimp (Litopenaeus vannamei, 87.66 mm ± 0.25 mm, 7.73 g ± 0.06 g) was examined at various concentrations of dissolved oxygen (DO, 1.9, 3.8, 6.8 and 13.6 mg L-1) in a swimming channel against one of the five flow velocities (v 1, v 2, v 3, v 4 and v 5). Metabolite contents in the plasma, hepatopancreas and pleopods muscle of the shrimp were quantified before and after swimming fatigue. The results revealed that the swimming speed and DO concentration were significant factors that affected the swimming endurance of L. vannamei. The relationship between swimming endurance and swimming speed at various DO concentrations can be described by the power model (ν·t b = a). The relationship between DO concentration (mg L-1) and the swimming ability index (SAI), defined as SAI = Σ{0/9000} vdt(cm), can be described as SAI = 27.947 DO0.137 (R 2 = 0.9312). The level of DO concentration directly affected the physiology of shrimp, and exposure to low concentrations of DO led to the increases in lactate and energetic substrate content in the shrimp. In responding to the low DO concentration at 1.9 mg L-1 and the swimming stress, L. vannamei exhibited a mix of aerobic and anaerobic metabolism to satisfy the energetic demand, mainly characterized by the utilization of total protein and glycogen and the production of lactate and glucose. Fatigue from swimming led to severe loss of plasma triglyceride at v 1, v 2, and v 3 with 1.9 mg L-1 DO, and at v 1 with 3.8, 6.8 and 13.6 mg L-1 DO, whereas the plasma glucose content increased significantly at v 3, v 4 and v 5 with 3.8 and 6.8 mg L-1 DO, and at v 5 with 13.6 mg L-1 DO. The plasma total protein and hepatopancreas glycogen were highly depleted in shrimp by swimming fatigue at various DO concentrations, whereas the plasma lactate accumulated at high levels after swimming fatigue at different velocities. These results were of particular value to understanding the locomotory ability of whiteleg

  18. Gait transition and oxygen consumption in swimming striped surfperch Embiotoca lateralis Agassiz

    DEFF Research Database (Denmark)

    Cannas, M.; Schaefer, J.; Domenici, P.

    2006-01-01

    A flow-through respirometer and swim tunnel was used to estimate the gait transition speed (Up-c) of striped surfperch Embiotoca lateralis, a labriform swimmer, and to investigate metabolic costs associated with gait transition. The Up-c was defined as the lowest speed at which fish decrease...... the use of pectoral fins significantly. While the tail was first recruited for manoeuvring at relatively low swimming speeds, the use of the tail at these low speeds [as low as 0·75 body (fork) lengths s-1, LF s-1) was rare (..., either in addition to pectoral fins or during burst-and-coast mode. Oxygen consumption increased exponentially with swimming speeds up to gait transition, and then levelled off. Similarly, cost of transport (CT) decreased with increasing speed, and then levelled off near Up-c. When speeds =Up...

  19. Mechanics of Mammalian Swimming

    Science.gov (United States)

    Wei, Timothy; Legac, Paul; Fish, Frank; Williams, Terrie; Mark, Russell; Hutchison, Sean

    2008-03-01

    Propulsion of large mammals (i.e. dolphins and humans) has been of great interest for both technological and athletic reasons. The foundational question is how fast can a mammal swim? Digital Particle Image Velocimetry (DPIV) has been modified to be safely used on swimmers and dolphins. Experiments of dolphins performing various swimming behaviors were performed at the Long Marine Laboratory, University of California, Santa Cruz. Vortices generated by the dolphins' tail motions were used to estimate thrust production. Also, a two-dimensional dynamic force balance was constructed to study and improve the mechanics of elite swimmers. Paired with an underwater video camera, the forces seen could be directly related to the motion of the swimmer. These force measurements could be correlated to time resolved DPIV measurements of flow around the swimmers. Measurements made with swimmers, Megan Jendrick (2000 Olympic gold medalist) and Ariana Kukors (4x US National Champion), as well as data from trials with two dolphins will be presented.

  20. Water droplets also swim!

    Science.gov (United States)

    van der Linden, Marjolein; Izri, Ziane; Michelin, Sébastien; Dauchot, Olivier

    2015-03-01

    Recently there has been a surge of interest in producing artificial swimmers. One possible path is to produce self-propelling droplets in a liquid phase. The self-propulsion often relies on complex mechanisms at the droplet interface, involving chemical reactions and the adsorption-desorption kinetics of the surfactant. Here, we report the spontaneous swimming of droplets in a very simple system: water droplets immersed in an oil-surfactant medium. The swimmers consist of pure water, with no additional chemical species inside: water droplets also swim! The swimming is very robust: the droplets are able to transport cargo such as large colloids, salt crystals, and even cells. In this talk we discuss the origin of the spontaneous motion. Water from the droplet is solubilized by the reverse micellar solution, creating a concentration gradient of swollen reverse micelles around each droplet. By generalizing a recently proposed instability mechanism, we explain how spontaneous motion emerges in this system at sufficiently large Péclet number. Our water droplets in an oil-surfactant medium constitute the first experimental realization of spontaneous motion of isotropic particles driven by this instability mechanism.

  1. Do resonating bells increase jellyfish swimming performance?

    Science.gov (United States)

    Hoover, Alexander; Miller, Laura

    2013-11-01

    A current question in swimming and flight is whether or not driving flexible appendages at their resonant frequency results in faster or more efficient locomotion. It has been suggested that jellyfish swim faster and/or more efficiently when the bell is driven at its resonant frequency. Previous work has modeled the jellyfish bell as a damped harmonic oscillator, and this simplified model suggests that work done by the bell is maximized when force is applied at the resonant frequency of the bell. We extend the idea of resonance phenomena of the jellyfish bell to a fluid structure interaction framework using the immersed boundary method. We first examine the effects of the bending stiffness of the bell on its resonant frequency. We then further our model with the inclusion of a ``muscular'' spring that connects the two sides of a 2D bell and drives it near its resonant frequency. We use this muscular spring to force the bell at varying frequencies and examine the work done by these springs and the resulting swimming speed. We finally augment our model with a flexible, passive bell margin to examine its role in propulsive efficiency.

  2. The determination of the swimming performance of rainbow trout (Oncorhynchus mykiss) under the effect of detergent

    Science.gov (United States)

    Esenbuǧa, Hülya; Alak, Gonca; Atamanalp, Muhammed

    2017-04-01

    Detergent residues can lead to continuous damage in the cell membranes and make them become sensitive to the harmful effects of other toxic substances and infection factors. In this study, the behavioral responses of rainbow trout have been studied at the end of 21 days, where they have been exposed to different concentrations of Sodium Dodecyl Sulphate (SDS). In the fish which have been exposed to two different doses of SDS material, the swimming performance has been examined for behavior analysis with emphasis on critical swimming speed. The effect of SDS on critical swimming speed has been found to be significant (p <0.05).

  3. Fasting goldfish, Carassius auratus, and common carp, Cyprinus carpio, use different metabolic strategies when swimming.

    Science.gov (United States)

    Liew, Hon Jung; Sinha, Amit Kumar; Mauro, Nathalie; Diricx, Marjan; Blust, Ronny; De Boeck, Gudrun

    2012-11-01

    Fish need to balance their energy use between digestion and other activities, and different metabolic compromises can be pursued. We examined the effects of fasting (7 days) on metabolic strategies in goldfish and common carp at different swimming levels. Fasting had no significant effect on swimming performance (U(crit)) of either species. Feeding and swimming profoundly elevated total ammonia (T(amm)) excretion in both species. In fed goldfish, this resulted in increased ammonia quotients (AQ), and additionally plasma and tissue ammonia levels increased with swimming reflecting the importance of protein contribution for aerobic metabolism. In carp, AQ did not change since oxygen consumption (MO(2)) and T(amm) excretion followed the same trend. Plasma ammonia did not increase with swimming suggesting a balance between production and excretion rate except for fasted carp at U(crit). While both species relied on anaerobic metabolism during exhaustive swimming, carp also showed increased lactate levels during routine swimming. Fasting almost completely depleted glycogen stores in carp, but not in goldfish. Both species used liver protein for basal metabolism during fasting and muscle lipid during swimming. In goldfish, feeding metabolism was sacrificed to support swimming metabolism with similar MO(2) and U(crit) between fasted and fed fish, whereas in common carp feeding increased MO(2) at U(crit) to sustain feeding and swimming independently. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. A Forced Damped Oscillation Framework for Undulatory Swimming Provides New Insights into How Propulsion Arises in Active and Passive Swimming

    Science.gov (United States)

    Bhalla, Amneet Pal Singh; Griffith, Boyce E.; Patankar, Neelesh A.

    2013-01-01

    A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions (“active” swimming) or by forces imparted by the surrounding fluid (“passive” swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained. PMID:23785272

  5. Unsteady bio-fluid dynamics in flying and swimming

    Science.gov (United States)

    Liu, Hao; Kolomenskiy, Dmitry; Nakata, Toshiyuki; Li, Gen

    2017-08-01

    Flying and swimming in nature present sophisticated and exciting ventures in biomimetics, which seeks sustainable solutions and solves practical problems by emulating nature's time-tested patterns, functions, and strategies. Bio-fluids in insect and bird flight, as well as in fish swimming are highly dynamic and unsteady; however, they have been studied mostly with a focus on the phenomena associated with a body or wings moving in a steady flow. Characterized by unsteady wing flapping and body undulation, fluid-structure interactions, flexible wings and bodies, turbulent environments, and complex maneuver, bio-fluid dynamics normally have challenges associated with low Reynolds number regime and high unsteadiness in modeling and analysis of flow physics. In this article, we review and highlight recent advances in unsteady bio-fluid dynamics in terms of leading-edge vortices, passive mechanisms in flexible wings and hinges, flapping flight in unsteady environments, and micro-structured aerodynamics in flapping flight, as well as undulatory swimming, flapping-fin hydrodynamics, body-fin interaction, C-start and maneuvering, swimming in turbulence, collective swimming, and micro-structured hydrodynamics in swimming. We further give a perspective outlook on future challenges and tasks of several key issues of the field.

  6. Mechanics of undulatory swimming in a frictional fluid.

    Directory of Open Access Journals (Sweden)

    Yang Ding

    Full Text Available The sandfish lizard (Scincus scincus swims within granular media (sand using axial body undulations to propel itself without the use of limbs. In previous work we predicted average swimming speed by developing a numerical simulation that incorporated experimentally measured biological kinematics into a multibody sandfish model. The model was coupled to an experimentally validated soft sphere discrete element method simulation of the granular medium. In this paper, we use the simulation to study the detailed mechanics of undulatory swimming in a "granular frictional fluid" and compare the predictions to our previously developed resistive force theory (RFT which models sand-swimming using empirically determined granular drag laws. The simulation reveals that the forward speed of the center of mass (CoM oscillates about its average speed in antiphase with head drag. The coupling between overall body motion and body deformation results in a non-trivial pattern in the magnitude of lateral displacement of the segments along the body. The actuator torque and segment power are maximal near the center of the body and decrease to zero toward the head and the tail. Approximately 30% of the net swimming power is dissipated in head drag. The power consumption is proportional to the frequency in the biologically relevant range, which confirms that frictional forces dominate during sand-swimming by the sandfish. Comparison of the segmental forces measured in simulation with the force on a laterally oscillating rod reveals that a granular hysteresis effect causes the overestimation of the body thrust forces in the RFT. Our models provide detailed testable predictions for biological locomotion in a granular environment.

  7. Mechanics of Undulatory Swimming in a Frictional Fluid

    Science.gov (United States)

    Ding, Yang; Sharpe, Sarah S.; Masse, Andrew; Goldman, Daniel I.

    2012-01-01

    The sandfish lizard (Scincus scincus) swims within granular media (sand) using axial body undulations to propel itself without the use of limbs. In previous work we predicted average swimming speed by developing a numerical simulation that incorporated experimentally measured biological kinematics into a multibody sandfish model. The model was coupled to an experimentally validated soft sphere discrete element method simulation of the granular medium. In this paper, we use the simulation to study the detailed mechanics of undulatory swimming in a “granular frictional fluid” and compare the predictions to our previously developed resistive force theory (RFT) which models sand-swimming using empirically determined granular drag laws. The simulation reveals that the forward speed of the center of mass (CoM) oscillates about its average speed in antiphase with head drag. The coupling between overall body motion and body deformation results in a non-trivial pattern in the magnitude of lateral displacement of the segments along the body. The actuator torque and segment power are maximal near the center of the body and decrease to zero toward the head and the tail. Approximately 30% of the net swimming power is dissipated in head drag. The power consumption is proportional to the frequency in the biologically relevant range, which confirms that frictional forces dominate during sand-swimming by the sandfish. Comparison of the segmental forces measured in simulation with the force on a laterally oscillating rod reveals that a granular hysteresis effect causes the overestimation of the body thrust forces in the RFT. Our models provide detailed testable predictions for biological locomotion in a granular environment. PMID:23300407

  8. Mechanics of undulatory swimming in a frictional fluid.

    Science.gov (United States)

    Ding, Yang; Sharpe, Sarah S; Masse, Andrew; Goldman, Daniel I

    2012-01-01

    The sandfish lizard (Scincus scincus) swims within granular media (sand) using axial body undulations to propel itself without the use of limbs. In previous work we predicted average swimming speed by developing a numerical simulation that incorporated experimentally measured biological kinematics into a multibody sandfish model. The model was coupled to an experimentally validated soft sphere discrete element method simulation of the granular medium. In this paper, we use the simulation to study the detailed mechanics of undulatory swimming in a "granular frictional fluid" and compare the predictions to our previously developed resistive force theory (RFT) which models sand-swimming using empirically determined granular drag laws. The simulation reveals that the forward speed of the center of mass (CoM) oscillates about its average speed in antiphase with head drag. The coupling between overall body motion and body deformation results in a non-trivial pattern in the magnitude of lateral displacement of the segments along the body. The actuator torque and segment power are maximal near the center of the body and decrease to zero toward the head and the tail. Approximately 30% of the net swimming power is dissipated in head drag. The power consumption is proportional to the frequency in the biologically relevant range, which confirms that frictional forces dominate during sand-swimming by the sandfish. Comparison of the segmental forces measured in simulation with the force on a laterally oscillating rod reveals that a granular hysteresis effect causes the overestimation of the body thrust forces in the RFT. Our models provide detailed testable predictions for biological locomotion in a granular environment.

  9. Partition of aerobic and anaerobic swimming costs related to gait transitions in a labriform swimmer

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Tudorache, Christian; Jordan, Anders D.

    2010-01-01

    was to partition aerobic and anaerobic swimming costs at speeds below and above the Up–c in the striped surfperch Embiotoca lateralis using swimming respirometry and video analysis to test the hypothesis that the gait transition marks the switch from aerobic to anaerobic power output. Exercise oxygen consumption...... rate was measured at 1.4, 1.9 and 2.3 L s–1. The presence and magnitude of excess post-exercise oxygen consumption (EPOC) were evaluated after each swimming speed. The data demonstrated that 1.4 L s–1 was below the Up–c, whereas 1.9 and 2.3 L s–1 were above the Up–c. These last two swimming speeds...

  10. Paramecia swimming in viscous flow

    Science.gov (United States)

    Zhang, P.; Jana, S.; Giarra, M.; Vlachos, P. P.; Jung, S.

    2015-12-01

    Ciliates like Paramecia exhibit fore-aft asymmetry in their body shapes, and preferentially swim in the direction of the slender anterior rather than the wider posterior. However, the physical reasons for this preference are not well understood. In this work, we propose that specific features of the fluid flow around swimming Paramecia confer some energetic advantage to the preferred swimming direction. Therefore, we seek to understand the effects of body asymmetry and swimming direction on the efficiency of swimming and the flux of fluid into the cilia layer (and thus of food into the oral groove), which we assumed to be primary factors in the energy budgets of these organisms. To this end, we combined numerical techniques (the boundary element method) and laboratory experiments (micro particle image velocimetry) to develop a quantitative model of the flow around a Paramecium and investigate the effect of the body shape on the velocity fields, as well as on the swimming and feeding behaviors. Both simulation and experimental results show that velocity fields exhibit fore-aft asymmetry. Moreover, the shape asymmetry revealed an increase of the fluid flux into the cilia layer compared to symmetric body shapes. Under the assumption that cilia fluid intake and feeding efficiency are primary factors in the energy budgets of Paramecia, our model predicts that the anterior swimming direction is energetically favorable to the posterior swimming direction.

  11. Turning Mechanics During Swimming by Oblate Hydromedusae

    Science.gov (United States)

    Costello, J.; Colin, S.; Sutherland, K.; Gemmell, B. J.

    2016-02-01

    Maneuverability is critical to the success of many species. Selective forces acting over millions of years have resulted in a range of capabilities currently unmatched by machines. Thus, understanding animal control of fluids for maneuvering has both biological and engineering applications. Medusae are radially symmetrical swimmers that must use asymmetric body motions to change direction during turning maneuvers. But what types of asymmetric motions are useful and how do they interact with surrounding fluids to generate rotational forces? We used high speed digital particle image velocimetry (DPIV) to investigate comparative swimming patterns of three hydromedusan species (Aequorea victoria, Clytia gregaria and Mitrocoma cellularia). We provide evidence for consistent animal-fluid interactions that underlie turning mechanics of oblate hydromedusae and provide new insights into the modulation and control of vorticity for low-speed animal maneuvering.

  12. Partition of aerobic and anaerobic swimming costs related to gait transitions in a labriform swimmer.

    Science.gov (United States)

    Svendsen, Jon C; Tudorache, Christian; Jordan, Anders D; Steffensen, John F; Aarestrup, Kim; Domenici, Paolo

    2010-07-01

    Members of the family Embiotocidae exhibit a distinct gait transition from exclusively pectoral fin oscillation to combined pectoral and caudal fin propulsion with increasing swimming speed. The pectoral-caudal gait transition occurs at a threshold speed termed U(p-c). The objective of this study was to partition aerobic and anaerobic swimming costs at speeds below and above the U(p-c) in the striped surfperch Embiotoca lateralis using swimming respirometry and video analysis to test the hypothesis that the gait transition marks the switch from aerobic to anaerobic power output. Exercise oxygen consumption rate was measured at 1.4, 1.9 and 2.3 L s(-1). The presence and magnitude of excess post-exercise oxygen consumption (EPOC) were evaluated after each swimming speed. The data demonstrated that 1.4 L s(-1) was below the U(p-c), whereas 1.9 and 2.3 L s(-1) were above the U(p-c). These last two swimming speeds included caudal fin propulsion in a mostly steady and unsteady (burst-assisted) mode, respectively. There was no evidence of EPOC after swimming at 1.4 and 1.9 L s(-1), indicating that the pectoral-caudal gait transition was not a threshold for anaerobic metabolism. At 2.3 L s(-1), E. lateralis switched to an unsteady burst and flap gait. This swimming speed resulted in EPOC, suggesting that anaerobic metabolism constituted 25% of the total costs. Burst activity correlated positively with the magnitude of the EPOC. Collectively, these data indicate that steady axial propulsion does not lead to EPOC whereas transition to burst-assisted swimming above U(p-c) is associated with anaerobic metabolism in this labriform swimmer.

  13. The Impact of Baby Swimming on Introductory and Elementary Swimming Training

    OpenAIRE

    Břízová, Gabriela

    2007-01-01

    THESIS ANNOTATION Title: The Impact of Baby Swimming on Introductory and Elementary Swimming Training Aim: To assess the impact of 'baby swimming' on the successfulness in introductory and partly in elementary swimming training, and to find out whether also other circumstances (for example the length of attendance at 'baby swimming') have some influence on introductory swimming training. Methods: We used a questionnaire method for the parents of children who had attended 'baby swimming' and f...

  14. Swimming level of pupils from elementary schools with own swimming pool

    OpenAIRE

    Zálupská, Klára

    2012-01-01

    Title: Swimming level of pupils from primary school with private swimming pool. Work objectives: The aim is to identify assess level of swimming of pupils from first to ninth grade of primary school with a private pool in Chomutov district using continuous swimming test with regular swimming lessons, which is started in the first grade and persists until the ninth grade. The condition was organizing a school swimming lessons once a week for 45 minutes in all grades. Methodology: Swimming leve...

  15. Stokesian swimming of a prolate spheroid at low Reynolds number

    CERN Document Server

    Felderhof, B U

    2016-01-01

    The swimming of a spheroid immersed in a viscous fluid and performing surface deformations periodically in time is studied on the basis of Stokes equations of low Reynolds number hydrodynamics. The average over a period of time of the swimming velocity and the rate of dissipation are given by integral expressions of second order in the amplitude of surface deformations. The first order flow velocity and pressure, as functions of spheroidal coordinates, are expressed as sums of basic solutions of Stokes equations. Sets of superposition coefficients of these solutions which optimize the mean swimming speed for given power are derived from an eigenvalue problem. The maximum eigenvalue is a measure of the efficiency of the optimal stroke within the chosen class of motions. The maximum eigenvalue for sets of low order is found to be a strongly increasing function of the aspect ratio of the spheroid.

  16. Analytical insights into optimality and resonance in fish swimming

    Science.gov (United States)

    Kohannim, Saba; Iwasaki, Tetsuya

    2014-01-01

    This paper provides analytical insights into the hypothesis that fish exploit resonance to reduce the mechanical cost of swimming. A simple body–fluid fish model, representing carangiform locomotion, is developed. Steady swimming at various speeds is analysed using optimal gait theory by minimizing bending moment over tail movements and stiffness, and the results are shown to match with data from observed swimming. Our analysis indicates the following: thrust–drag balance leads to the Strouhal number being predetermined based on the drag coefficient and the ratio of wetted body area to cross-sectional area of accelerated fluid. Muscle tension is reduced when undulation frequency matches resonance frequency, which maximizes the ratio of tail-tip velocity to bending moment. Finally, hydrodynamic resonance determines tail-beat frequency, whereas muscle stiffness is actively adjusted, so that overall body–fluid resonance is exploited. PMID:24430125

  17. Computer assisted video analysis of swimming performance in a forced swim test: simultaneous assessment of duration of immobility and swimming style in mice selected for high and low swim-stress induced analgesia.

    Science.gov (United States)

    Juszczak, Grzegorz R; Lisowski, Paweł; Sliwa, Adam T; Swiergiel, Artur H

    2008-10-20

    In behavioral pharmacology, two problems are encountered when quantifying animal behavior: 1) reproducibility of the results across laboratories, especially in the case of manual scoring of animal behavior; 2) presence of different behavioral idiosyncrasies, common in genetically different animals, that mask or mimic the effects of the experimental treatments. This study aimed to develop an automated method enabling simultaneous assessment of the duration of immobility in mice and the depth of body submersion during swimming by means of computer assisted video analysis system (EthoVision from Noldus). We tested and compared parameters of immobility based either on the speed of an object (animal) movement or based on the percentage change in the object's area between the consecutive video frames. We also examined the effects of an erosion-dilation filtering procedure on the results obtained with both parameters of immobility. Finally, we proposed an automated method enabling assessment of depth of body submersion that reflects swimming performance. It was found that both parameters of immobility were sensitive to the effect of an antidepressant, desipramine, and that they yielded similar results when applied to mice that are good swimmers. The speed parameter was, however, more sensitive and more reliable because it depended less on random noise of the video image. Also, it was established that applying the erosion-dilation filtering procedure increased the reliability of both parameters of immobility. In case of mice that were poor swimmers, the assessed duration of immobility differed depending on a chosen parameter, thus resulting in the presence or lack of differences between two lines of mice that differed in swimming performance. These results substantiate the need for assessing swimming performance when the duration of immobility in the FST is compared in lines that differ in their swimming "styles". Testing swimming performance can also be important in the

  18. [Swimming, physical activity and health: a historical perspective].

    Science.gov (United States)

    Conti, A A

    2015-01-01

    Swimming, which is the coordinated and harmonic movement of the human body inside a liquid medium by means of the combined action of the superior and inferior limbs, is a physical activity which is diffused throughout the whole world and it is practiced by healthy and non-healthy subjects. Swimming is one of the physical activities with less contraindications and, with limited exceptions, can be suggested to individuals of both sexes and of every age range, including the most advanced. Swimming requires energy both for the floating process and for the anterograde progression, with a different and variable osteo-arthro-muscular involvement according to the different styles. The energetic requirement is about four times that for running, with an overall efficiency inferior to 10%; the energetic cost of swimming in the female subject is approximately two thirds of that in the male subject. The moderate aerobic training typical of swimming is useful for diabetic and hypertensive individuals, for people with painful conditions of rachis, as also for obese and orthopaedic patients. Motor activity inside the water reduces the risk of muscular-tendinous lesions and, without loading the joints in excess, requires the harmonic activation of the whole human musculature. Swimming is an activity requiring multiple abilities, ranging from a sense of equilibrium to that of rhythm, from reaction speed to velocity, from joint mobility to resistance. The structured interest for swimming in the perspective of human health from the beginning of civilization, as described in this contribution, underlines the relevance attributed to this activity in the course of human history.

  19. 21 CFR 1250.89 - Swimming pools.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Swimming pools. 1250.89 Section 1250.89 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.89 Swimming pools. (a) Fill and draw swimming pools shall not be installed or used. (b) Swimming pools of the recirculation type shall be...

  20. Efficient swimming of an assembly of rigid spheres at low Reynolds number

    CERN Document Server

    Felderhof, B U

    2015-01-01

    The swimming of an assembly of rigid spheres immersed in a viscous fluid of infinite extent is studied in low Reynolds number hydrodynamics. The instantaneous swimming velocity and rate of dissipation are expressed in terms of the time-dependent displacements of sphere centers about their collective motion. For small amplitude swimming with periodically oscillating displacements, optimization of the mean swimming speed at given mean power leads to an eigenvalue problem involving a velocity matrix and a power matrix. The corresponding optimal stroke permits generalization to large amplitude motion in a model of spheres with harmonic interactions and corresponding actuating forces. The method allows straightforward calculation of the swimming performance of structures modeled as assemblies of interacting rigid spheres. A model of three collinear spheres with motion along the common axis is studied as an example.

  1. System Wide Information Management (SWIM)

    Science.gov (United States)

    Hritz, Mike; McGowan, Shirley; Ramos, Cal

    2004-01-01

    This viewgraph presentation lists questions regarding the implementation of System Wide Information Management (SWIM). Some of the questions concern policy issues and strategies, technology issues and strategies, or transition issues and strategies.

  2. Public swimming in Roudnice nad Labem

    OpenAIRE

    Trč, Stanislav

    2014-01-01

    Title: Public swimming in Roudnice nad Labem Target: This thesis aims to explore the public's interest in swimming, chart the course of their visits to the swimming pool and find out personal interest in improving swimming techniques. Assess the importance of the swimming section for the public with regard to the possibility of physical activity for children and youth. Methods: Information from public in Roudnice nad Labem were obtained by using questionnaires. The results of the questionnair...

  3. Fast-swimming hydromedusae exploit velar kinematics to form an optimal vortex wake.

    Science.gov (United States)

    Dabiri, John O; Colin, Sean P; Costello, John H

    2006-06-01

    Fast-swimming hydromedusan jellyfish possess a characteristic funnel-shaped velum at the exit of their oral cavity that interacts with the pulsed jets of water ejected during swimming motions. It has been previously assumed that the velum primarily serves to augment swimming thrust by constricting the ejected flow in order to produce higher jet velocities. This paper presents high-speed video and dye-flow visualizations of free-swimming Nemopsis bachei hydromedusae, which instead indicate that the time-dependent velar kinematics observed during the swimming cycle primarily serve to optimize vortices formed by the ejected water rather than to affect the speed of the ejected flow. Optimal vortex formation is favorable in fast-swimming jellyfish because, unlike the jet funnelling mechanism, it allows for the minimization of energy costs while maximizing thrust forces. However, the vortex ;formation number' corresponding to optimality in N. bachei is substantially greater than the value of 4 found in previous engineering studies of pulsed jets from rigid tubes. The increased optimal vortex formation number is attributable to the transient velar kinematics exhibited by the animals. A recently developed model for instantaneous forces generated during swimming motions is implemented to demonstrate that transient velar kinematics are required in order to achieve the measured swimming trajectories. The presence of velar structures in fast-swimming jellyfish and the occurrence of similar jet-regulating mechanisms in other jet-propelled swimmers (e.g. the funnel of squid) appear to be a primary factor contributing to success of fast-swimming jetters, despite their primitive body plans.

  4. Volumetric flow imaging reveals the importance of vortex ring formation in squid swimming tail-first and arms-first

    National Research Council Canada - National Science Library

    Bartol, Ian K; Krueger, Paul S; Jastrebsky, Rachel A; Williams, Sheila; Thompson, Joseph T

    2016-01-01

    .... Defocusing digital particle tracking velocimetry, a volumetric velocimetry technique, and high-speed videography were used to study arms-first and tail-first swimming of brief squid Lolliguncula...

  5. Grundfoss: Chlorination of Swimming Pools

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Hogan, John; Andreassen, Viggo

    1998-01-01

    Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools.......Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools....

  6. Is paramecium swimming autonomic?

    Science.gov (United States)

    Bandyopadhyay, Promode R.; Toplosky, Norman; Hansen, Joshua

    2010-11-01

    We seek to explore if the swimming of paramecium has an underlying autonomic mechanism. Such robotic elements may be useful in capturing the disturbance field in an environment in real time. Experimental evidence is emerging that motion control neurons of other animals may be present in paramecium as well. The limit cycle determined using analog simulation of the coupled nonlinear oscillators of olivo-cerebellar dynamics (ieee joe 33, 563-578, 2008) agrees with the tracks of the cilium of a biological paramecium. A 4-motor apparatus has been built that reproduces the kinematics of the cilium motion. The motion of the biological cilium has been analyzed and compared with the results of the finite element modeling of forces on a cilium. The modeling equates applied torque at the base of the cilium with drag, the cilium stiffness being phase dependent. A low friction pendulum apparatus with a multiplicity of electromagnetic actuators is being built for verifying the maps of the attractor basin computed using the olivo-cerebellar dynamics for different initial conditions. Sponsored by ONR 33.

  7. Swimming with the Shoal

    Science.gov (United States)

    Childs, Ann

    2017-10-01

    This article responds to Yuli Rahmawati and Peter Charles Taylor's piece and explores my role as a science teacher, science teacher educator and researcher in two contexts, Sierra Leone and Bhutan. In the first part of the article I reflect on my 3 years as a science teacher in Sierra Leone and demonstrate resonances with Yuli's accounts of culture shock and with her positioning of herself in a third space. I also reflect on the importance of colleagues in helping me reshape my identity as a science teacher in this new context. The second part of the article reflects on much shorter periods of time in Bhutan and my work as a teacher educator and researcher where, unlike Sierra Leone, it was not possible because of the short periods I worked there, to occupy a third space. I close by discussing how in Bhutan, but also Sierra Leone, collaboration with colleagues allowed me to contribute my own expertise, despite my lack of a deep understanding of the cultural context, in a way that was as valuable as possible. I liken this way of collaborative working in my professional life as `swimming with the shoal'.

  8. Pop up satellite tags impair swimming performance and energetics of the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Methling, Caroline; Tudorache, Christian; Skov, Peter Vilhelm

    2011-01-01

    increased oxygen consumption (MO(2)) during swimming and elevated minimum cost of transport (COT(min)) by 26 Standard (SMR) and active metabolic rate (AMR) as well as metabolic scope remained unaffected, suggesting that the observed effects were caused by increased drag. Optimal swimming speed (U......Pop-up satellite archival tags (PSATs) have recently been applied in attempts to follow the oceanic spawning migration of the European eel. PSATs are quite large, and in all likelihood their hydraulic drag constitutes an additional cost during swimming, which remains to be quantified, as does...... and efficiency all are significantly affected in migrating eels with external tags....

  9. Volumetric flow imaging reveals the importance of vortex ring formation in squid swimming tail-first and arms-first.

    Science.gov (United States)

    Bartol, Ian K; Krueger, Paul S; Jastrebsky, Rachel A; Williams, Sheila; Thompson, Joseph T

    2016-02-01

    Squids use a pulsed jet and fin movements to swim both arms-first (forward) and tail-first (backward). Given the complexity of the squid multi-propulsor system, 3D velocimetry techniques are required for the comprehensive study of wake dynamics. Defocusing digital particle tracking velocimetry, a volumetric velocimetry technique, and high-speed videography were used to study arms-first and tail-first swimming of brief squid Lolliguncula brevis over a broad range of speeds [0-10 dorsal mantle lengths (DML) s(-1)] in a swim tunnel. Although there was considerable complexity in the wakes of these multi-propulsor swimmers, 3D vortex rings and their derivatives were prominent reoccurring features during both tail-first and arms-first swimming, with the greatest jet and fin flow complexity occurring at intermediate speeds (1.5-3.0 DML s(-1)). The jet generally produced the majority of thrust during rectilinear swimming, increasing in relative importance with speed, and the fins provided no thrust at speeds >4.5 DML s(-1). For both swimming orientations, the fins sometimes acted as stabilizers, producing negative thrust (drag), and consistently provided lift at low/intermediate speeds (swimming orientation, and η for swimming sequences with clear isolated jet vortex rings was significantly greater (η=78.6±7.6%, mean±s.d.) than that for swimming sequences with clear elongated regions of concentrated jet vorticity (η=67.9±19.2%). This study reveals the complexity of 3D vortex wake flows produced by nekton with hydrodynamically distinct propulsors. © 2016. Published by The Company of Biologists Ltd.

  10. Warm water and cool nests are best. How global warming might influence hatchling green turtle swimming performance.

    Directory of Open Access Journals (Sweden)

    David T Booth

    Full Text Available For sea turtles nesting on beaches surrounded by coral reefs, the most important element of hatchling recruitment is escaping predation by fish as they swim across the fringing reef, and as a consequence hatchlings that minimize their exposure to fish predation by minimizing the time spent crossing the fringing reef have a greater chance of surviving the reef crossing. One way to decrease the time required to cross the fringing reef is to maximize swimming speed. We found that both water temperature and nest temperature influence swimming performance of hatchling green turtles, but in opposite directions. Warm water increases swimming ability, with hatchling turtles swimming in warm water having a faster stroke rate, while an increase in nest temperature decreases swimming ability with hatchlings from warm nests producing less thrust per stroke.

  11. Influence of pre-school swimming on level of swimming abilities of early schol age children

    OpenAIRE

    Velová, Lenka

    2011-01-01

    My thesis paper is focused on children swimming from their birth to early school age. The pivotal part of the paper is the comparison of swimming abilities between primary school children who have passed pre-school swimming training and those who have had no training at all. Theoretical framework of the paper is then focused on general swimming theory, characteristics of children's evolutionary stages within the context of swimming and definition of basic swimming skills.

  12. Effect of morphological fin curl on the swimming performance and station-holding ability of juvenile shovelnose sturgeon

    Science.gov (United States)

    Deslauriers, David; Johnston, Ryan; Chipps, Steven R.

    2016-01-01

    We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

  13. Travel at low energetic cost by swimming and wave-riding bottlenose dolphins.

    Science.gov (United States)

    Williams, T M; Friedl, W A; Fong, M L; Yamada, R M; Sedivy, P; Haun, J E

    1992-02-27

    Over the past 50 years there has been much speculation about the energetic cost of swimming and wave-riding by dolphins. When aligned properly in front of the bow of moving ships in the stern wake of small boats, on wind waves, and even in the wake of larger cetaceans, the animals appear to move effortlessly through the water without the benefit of propulsive strokes by the flukes. Theoretically, body streamlining as well as other anatomical and behavioural adaptations contribute to low transport costs in these animals. The economy of movement permitted by wave-riding has been perceived as an energetic advantage for the swimming dolphin, but has been hard to prove in the absence of physiological data for exercising cetaceans. Here we determine the aerobic and anaerobic costs of swimming and wave-riding in bottlenose dolphins and find that the minimum cost of transport for swimming dolphins is 1.29 +/- 0.05 J kg-1 m-1 at a cruising speed of 2.1 m s-1. Aerobic costs are nearly twice as high for swimming seals and sea lions, and 8-12 times higher for human swimmers. Wave-riding by dolphins provides additional benefits in terms of speed. The results indicate that behavioural, physiological and morphological factors make swimming an economical form of high-speed travel for dolphins.

  14. Pectoral fin beat frequency predicts oxygen consumption during spontaneous activity in a labriform swimming fish (Embiotoca lateralis)

    DEFF Research Database (Denmark)

    Tudorache, Christian; Jordan, Anders D.; Svendsen, Jon Christian

    2009-01-01

    The objective of this study was to identify kinematic variables correlated with oxygen consumption during spontaneous labriform swimming. Kinematic variables (swimming speed, change of speed, turning angle, turning rate, turning radius and pectoral fin beat frequency) and oxygen consumption (MO2....... Complementary to other methods within biotelemetry such as EMG it is suggested that such correlations of pectoral fin beat frequency may be used to measure the energy requirements of labriform swimming fish such as E. lateralis in the field, but need to be taken with great caution since movement and oxygen...

  15. Nutrition for swimming.

    Science.gov (United States)

    Shaw, Gregory; Boyd, Kevin T; Burke, Louise M; Koivisto, Anu

    2014-08-01

    Swimming is a sport that requires considerable training commitment to reach individual performance goals. Nutrition requirements are specific to the macrocycle, microcycle, and individual session. Swimmers should ensure suitable energy availability to support training while maintaining long term health. Carbohydrate intake, both over the day and in relation to a workout, should be manipulated (3-10 g/kg of body mass/day) according to the fuel demands of training and the varying importance of undertaking these sessions with high carbohydrate availability. Swimmers should aim to consume 0.3 g of high-biological-value protein per kilogram of body mass immediately after key sessions and at regular intervals throughout the day to promote tissue adaptation. A mixed diet consisting of a variety of nutrient-dense food choices should be sufficient to meet the micronutrient requirements of most swimmers. Specific dietary supplements may prove beneficial to swimmers in unique situations, but should be tried only with the support of trained professionals. All swimmers, particularly adolescent and youth swimmers, are encouraged to focus on a well-planned diet to maximize training performance, which ensures sufficient energy availability especially during periods of growth and development. Swimmers are encouraged to avoid rapid weight fluctuations; rather, optimal body composition should be achieved over longer periods by modest dietary modifications that improve their food choices. During periods of reduced energy expenditure (taper, injury, off season) swimmers are encouraged to match energy intake to requirement. Swimmers undertaking demanding competition programs should ensure suitable recovery practices are used to maintain adequate glycogen stores over the entirety of the competition period.

  16. Disease resistance is related to inherent swimming performance in Atlantic salmon.

    OpenAIRE

    Castro Vicente; Grisdale-Helland Barbara; Jørgensen Sven M; Helgerud Jan; Claireaux Guy; Farrell Anthony P; Krasnov Aleksei; Helland Ståle J; Takle Harald

    2013-01-01

    Abstract Background Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming p...

  17. Swimming and other activities: applied aspects of fish swimming performance

    Science.gov (United States)

    Castro-Santos, Theodore R.; Farrell, A.P.

    2011-01-01

    Human activities such as hydropower development, water withdrawals, and commercial fisheries often put fish species at risk. Engineered solutions designed to protect species or their life stages are frequently based on assumptions about swimming performance and behaviors. In many cases, however, the appropriate data to support these designs are either unavailable or misapplied. This article provides an overview of the state of knowledge of fish swimming performance – where the data come from and how they are applied – identifying both gaps in knowledge and common errors in application, with guidance on how to avoid repeating mistakes, as well as suggestions for further study.

  18. Numerical study on the hydrodynamics of thunniform bio-inspired swimming under self-propulsion.

    Directory of Open Access Journals (Sweden)

    Ningyu Li

    Full Text Available Numerical simulations are employed to study the hydrodynamics of self-propelled thunniform swimming. The swimmer is modeled as a tuna-like flexible body undulating with kinematics of thunniform type. The wake evolution follows the vortex structures arranged nearly vertical to the forward direction, vortex dipole formation resulting in the propulsion motion, and finally a reverse Kármán vortex street. We also carry out a systematic parametric study of various aspects of the fluid dynamics behind the freely swimming behavior, including the swimming speed, hydrodynamic forces, power requirement and wake vortices. The present results show that the fin thrust as well as swimming velocity is an increasing function of both tail undulating amplitude Ap and oscillating amplitude of the caudal fin θm. Whereas change on the propulsive performance with Ap is associated with the strength of wake vortices and the area of suction region on the fin, the swimming performance improves with θm due to the favorable tilting of the fin that make the pressure difference force more oriented toward the thrust direction. Moreover, the energy loss in the transverse direction and the power requirement increase with Ap but decrease with θm, and this indicates that for achieving a desired swimming speed increasing θm seems more efficiently than increasing Ap. Furthermore, we have compared the current simulations with the published experimental studies on undulatory swimming. Comparisons show that our work tackles the flow regime of natural thunniform swimmers and follows the principal scaling law of undulatory locomotion reported. Finally, this study enables a detailed quantitative analysis, which is difficult to obtain by experiments, of the force production of the thunniform mode as well as its connection to the self-propelled swimming kinematics and vortex wake structure. The current findings help provide insights into the swimming performance and mechanisms of self

  19. Numerical study on the hydrodynamics of thunniform bio-inspired swimming under self-propulsion.

    Science.gov (United States)

    Li, Ningyu; Liu, Huanxing; Su, Yumin

    2017-01-01

    Numerical simulations are employed to study the hydrodynamics of self-propelled thunniform swimming. The swimmer is modeled as a tuna-like flexible body undulating with kinematics of thunniform type. The wake evolution follows the vortex structures arranged nearly vertical to the forward direction, vortex dipole formation resulting in the propulsion motion, and finally a reverse Kármán vortex street. We also carry out a systematic parametric study of various aspects of the fluid dynamics behind the freely swimming behavior, including the swimming speed, hydrodynamic forces, power requirement and wake vortices. The present results show that the fin thrust as well as swimming velocity is an increasing function of both tail undulating amplitude Ap and oscillating amplitude of the caudal fin θm. Whereas change on the propulsive performance with Ap is associated with the strength of wake vortices and the area of suction region on the fin, the swimming performance improves with θm due to the favorable tilting of the fin that make the pressure difference force more oriented toward the thrust direction. Moreover, the energy loss in the transverse direction and the power requirement increase with Ap but decrease with θm, and this indicates that for achieving a desired swimming speed increasing θm seems more efficiently than increasing Ap. Furthermore, we have compared the current simulations with the published experimental studies on undulatory swimming. Comparisons show that our work tackles the flow regime of natural thunniform swimmers and follows the principal scaling law of undulatory locomotion reported. Finally, this study enables a detailed quantitative analysis, which is difficult to obtain by experiments, of the force production of the thunniform mode as well as its connection to the self-propelled swimming kinematics and vortex wake structure. The current findings help provide insights into the swimming performance and mechanisms of self

  20. The swimming behavior of flagellated bacteria in viscous and viscoelastic media

    Science.gov (United States)

    Qu, Zijie; Henderikx, Rene; Breuer, Kenneth

    2016-11-01

    The motility of bacteria E.coli in viscous and viscoelastic fluids has been widely studied although full understanding remains elusive. The swimming mode of wild-type E.coli is well-described by a run-and-tumble sequence in which periods of straight swimming at a constant speed are randomly interrupted by a tumble, defined as a sudden change of direction with a very low speed. Using a tracking microscope, we follow cells for extended periods of time and find that the swimming behavior can be more complex, and can include a wider variety of behaviors including a "slow random walk" in which the cells move at relatively low speed without the characteristic run. Significant variation between individual cells is observed, and furthermore, a single cell can change its motility during the course of a tracking event. Changing the viscosity and viscoelasticy of the swimming media also has profound effects on the average swimming speed and run-tumble nature of the cell motility, including changing the distribution, duration of tumbling and slow random walk events. The reasons for these changes are explained using a Purcell-style resistive force model for the cell and flagellar behavior as well as model for the changes in flagellar bundling in different fluid viscosities. National Science Foundation.

  1. Resolving shifting patterns of muscle energy use in swimming fish.

    Directory of Open Access Journals (Sweden)

    Shannon P Gerry

    Full Text Available Muscle metabolism dominates the energy costs of locomotion. Although in vivo measures of muscle strain, activity and force can indicate mechanical function, similar muscle-level measures of energy use are challenging to obtain. Without this information locomotor systems are essentially a black box in terms of the distribution of metabolic energy. Although in situ measurements of muscle metabolism are not practical in multiple muscles, the rate of blood flow to skeletal muscle tissue can be used as a proxy for aerobic metabolism, allowing the cost of particular muscle functions to be estimated. Axial, undulatory swimming is one of the most common modes of vertebrate locomotion. In fish, segmented myotomal muscles are the primary power source, driving undulations of the body axis that transfer momentum to the water. Multiple fins and the associated fin muscles also contribute to thrust production, and stabilization and control of the swimming trajectory. We have used blood flow tracers in swimming rainbow trout (Oncorhynchus mykiss to estimate the regional distribution of energy use across the myotomal and fin muscle groups to reveal the functional distribution of metabolic energy use within a swimming animal for the first time. Energy use by the myotomal muscle increased with speed to meet thrust requirements, particularly in posterior myotomes where muscle power outputs are greatest. At low speeds, there was high fin muscle energy use, consistent with active stability control. As speed increased, and fins were adducted, overall fin muscle energy use declined, except in the caudal fin muscles where active fin stiffening is required to maintain power transfer to the wake. The present data were obtained under steady-state conditions which rarely apply in natural, physical environments. This approach also has potential to reveal the mechanical factors that underlie changes in locomotor cost associated with movement through unsteady flow regimes.

  2. Resolving Shifting Patterns of Muscle Energy Use in Swimming Fish

    Science.gov (United States)

    Gerry, Shannon P.; Ellerby, David J.

    2014-01-01

    Muscle metabolism dominates the energy costs of locomotion. Although in vivo measures of muscle strain, activity and force can indicate mechanical function, similar muscle-level measures of energy use are challenging to obtain. Without this information locomotor systems are essentially a black box in terms of the distribution of metabolic energy. Although in situ measurements of muscle metabolism are not practical in multiple muscles, the rate of blood flow to skeletal muscle tissue can be used as a proxy for aerobic metabolism, allowing the cost of particular muscle functions to be estimated. Axial, undulatory swimming is one of the most common modes of vertebrate locomotion. In fish, segmented myotomal muscles are the primary power source, driving undulations of the body axis that transfer momentum to the water. Multiple fins and the associated fin muscles also contribute to thrust production, and stabilization and control of the swimming trajectory. We have used blood flow tracers in swimming rainbow trout (Oncorhynchus mykiss) to estimate the regional distribution of energy use across the myotomal and fin muscle groups to reveal the functional distribution of metabolic energy use within a swimming animal for the first time. Energy use by the myotomal muscle increased with speed to meet thrust requirements, particularly in posterior myotomes where muscle power outputs are greatest. At low speeds, there was high fin muscle energy use, consistent with active stability control. As speed increased, and fins were adducted, overall fin muscle energy use declined, except in the caudal fin muscles where active fin stiffening is required to maintain power transfer to the wake. The present data were obtained under steady-state conditions which rarely apply in natural, physical environments. This approach also has potential to reveal the mechanical factors that underlie changes in locomotor cost associated with movement through unsteady flow regimes. PMID:25165858

  3. Human sperm swimming in a high viscosity mucus analogue.

    Science.gov (United States)

    Ishimoto, Kenta; Gadêlha, Hermes; Gaffney, Eamonn A; Smith, David J; Kirkman-Brown, Jackson

    2018-02-17

    Remarkably, mammalian sperm maintain a substantive proportion of their progressive swimming speed within highly viscous fluids, including those of the female reproductive tract. Here, we analyse the digital microscopy of a human sperm swimming in a highly viscous, weakly elastic mucus analogue. We exploit principal component analysis to simplify its flagellar beat pattern, from which boundary element calculations are used to determine the time-dependent flow field around the sperm cell. The sperm flow field is further approximated in terms of regularized point forces, and estimates of the mechanical power consumption are determined, for comparison with analogous low viscosity media studies. This highlights extensive differences in the structure of the flows surrounding human sperm in different media, indicating how the cell-cell and cell-boundary hydrodynamic interactions significantly differ with the physical microenvironment. The regularized point force decomposition also provides cell-level information that may ultimately be incorporated into sperm population models. We further observe indications that the core feature in explaining the effectiveness of sperm swimming in high viscosity media is the loss of cell yawing, which is related with a greater density of regularized point force singularities along the axis of symmetry of the flagellar beat to represent the flow field. In turn this implicates a reduction of the wavelength of the distal beat pattern - and hence dynamical wavelength selection of the flagellar beat - as the dominant feature governing the effectiveness of sperm swimming in highly viscous media. Copyright © 2018. Published by Elsevier Ltd.

  4. Water Evaporation in Swimming Baths

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which are repres......This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which...

  5. Surface Waters Information Management System (SWIMS)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Surface Waters Information Management System (SWIMS) has been designed to meet multi-agency hydrologic database needs for Kansas. The SWIMS project was supported...

  6. Strategies for swimming: explorations of the behaviour of a neuro-musculo-mechanical model of the lamprey

    Science.gov (United States)

    Williams, Thelma L.; McMillen, Tyler

    2015-01-01

    ABSTRACT Experiments were performed on a neuro-musculo-mechanical model of a lamprey, to explore the strategies for controlling swimming speed. The muscle component of the model was based on previous experiments on isolated lamprey muscle. The patterns of muscle activation were those found in EMG studies on swimming lampreys. The fluid mechanics were modelled with G.I. Taylor's simplification. Tail beat frequencies of 2–6 sec−1 were combined with muscle activation strengths of 0.1% to 20% of maximum tetanic isometric strength. The resulting forward swimming speed and changing body shape were recorded. From the changing body shape the speed of the backward-travelling wave of curvature was calculated, as well as the ratio between the speeds of the waves of activation and curvature. For any given activation strength there was a tail beat frequency that gave maximal forward speed. Furthermore, for all the combinations of activation strength and tail beat frequency that gave such maximum swimming speeds, the ratio of the speed of the wave of curvature to the wave of muscle activation was approximately 0.75. This is similar to the ratio found in swimming lampreys. PMID:25661866

  7. Strategies for swimming: explorations of the behaviour of a neuro-musculo-mechanical model of the lamprey

    Directory of Open Access Journals (Sweden)

    Thelma L. Williams

    2015-02-01

    Full Text Available Experiments were performed on a neuro-musculo-mechanical model of a lamprey, to explore the strategies for controlling swimming speed. The muscle component of the model was based on previous experiments on isolated lamprey muscle. The patterns of muscle activation were those found in EMG studies on swimming lampreys. The fluid mechanics were modelled with G.I. Taylor's simplification. Tail beat frequencies of 2–6 sec−1 were combined with muscle activation strengths of 0.1% to 20% of maximum tetanic isometric strength. The resulting forward swimming speed and changing body shape were recorded. From the changing body shape the speed of the backward-travelling wave of curvature was calculated, as well as the ratio between the speeds of the waves of activation and curvature. For any given activation strength there was a tail beat frequency that gave maximal forward speed. Furthermore, for all the combinations of activation strength and tail beat frequency that gave such maximum swimming speeds, the ratio of the speed of the wave of curvature to the wave of muscle activation was approximately 0.75. This is similar to the ratio found in swimming lampreys.

  8. Modelling swimming hydrodynamics to enhance performance

    OpenAIRE

    D.A. Marinho; Rouboa, A.; Barbosa, Tiago M.; Silva, A.J.

    2010-01-01

    Swimming assessment is one of the most complex but outstanding and fascinating topics in biomechanics. Computational fluid dynamics (CFD) methodology is one of the different methods that have been applied in swimming research to observe and understand water movements around the human body and its application to improve swimming performance. CFD has been applied attempting to understand deeply the biomechanical basis of swimming. Several studies have been conducted willing to analy...

  9. Effects of loss of visual feedback on performance of two swimming strokes.

    Science.gov (United States)

    Cicciarella, C F

    1982-12-01

    20 subjects, aged 11 to 21 yr., skilled in competitive swimming in both the crawl and the breaststroke, performed a total of 8 timed swimming trials of 25 yd. in both strokes both with and without blindfolds to test the hypothesis that the loss in performance which would occur with loss of visual feedback is related to the complexity of the motor skill being performed. After correction for differences in the speed of each stroke, the loss in speed (performance decrement) in the more complex stroke (crawl) was significantly greater than the decrement in the less complex (breast) stroke.

  10. 36 CFR 327.5 - Swimming.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Swimming. 327.5 Section 327.5 Parks, Forests, and Public Property CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY RULES AND REGULATIONS... Swimming. (a) Swimming, wading, snorkeling or scuba diving at one's own risk is permitted, except at...

  11. 36 CFR 331.10 - Swimming.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Swimming. 331.10 Section 331.10 Parks, Forests, and Public Property CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY REGULATIONS..., KENTUCKY AND INDIANA § 331.10 Swimming. Swimming is prohibited unless authorized in writing by the District...

  12. 43 CFR 423.36 - Swimming.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Swimming. 423.36 Section 423.36 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR... Swimming. (a) You may swim, wade, snorkel, scuba dive, raft, or tube at your own risk in Reclamation waters...

  13. The dynamics of the swimming speed of the participants in the “24 Aquamasters” swimming marathon

    Directory of Open Access Journals (Sweden)

    Marcel RĂSĂDEAN

    2012-06-01

    Full Text Available Besides a short presentation of the event, through the present paper we aim to study the impact of the factors that influence sportive performance on the participants in such a competition.

  14. Physiological and biomechanical in different swimming intensities

    Directory of Open Access Journals (Sweden)

    Sebastião Iberes Lopes de Melo

    2004-06-01

    Full Text Available The objective of this study was to analyze the physiological and biomechanical responses of swimmers at different swimming intensities. The intentionally selected sample was composed by seven athletes with swimming times for qualifying on the Brazilian Swimming Championship. A series of 8x200 free style swimming at speeds of 80%, 85%, 90%, 95% and 100% of individual maximum effort was used as the task. A film camera of 60 Hz and an Accusport mMol lactimeter were used for data collection. Descriptive statistics, analysis of variance (ANOVA with “post-hoc” Tukey test and Spearman’s correlation were used for statistical analyses to identify the differences between athletes for the variables blood lactate, crawl stroke frequency (FB and dimension (BR at different intensities. The level of significance was set at 0.05. Based on the results, there were significant differences on swimming technique among effort intensities, for both the physiological and mechanical responses, especially at levels above 95% individual maximum effort. The high correlation between blood lactate and crawl stroke frequency and length, and between crawl stroke frequency and length, with the last two correlations being negative, indicated that the proposed series was adequate to analyze physiological and biomechanical response. It was concluded that as the intensity increases, there is a need for mechanical adjustments to enable the athletes to endure different speeds. It was also possible to establish the ideal swimming speed for each energetic zone, providing data for coaches and athletes to train both speed and technique within the specific energetic zones. RESUMO O objetivo deste estudo foi analisar as respostas fisiológicas e biomecânicas de nadadores em diferentes intensidades de nado. A amostra, intencionalmente escolhida, foi composta por sete atletas que possuíam índices de participação em campeonato brasileiro absoluto. Foi utilizada como tarefa de

  15. The influence of elements of synchronized swimming on technique of the selected swimming strokes

    OpenAIRE

    Široký, Michal

    2015-01-01

    Title: The influence of elements of synchronized swimming on technique of the selected swimming strokes Objectives: The objective of the thesis is to assess the effect of the elements of synchronized swimming at improving the techniques of swimming. Methods: The results were detected by overt observation with active participation and subsequent scaling on the ordinal scale 1 to 5. Results: The results show that the influence of the elements of synchronized swimming on improving the technique ...

  16. Fluid Mechanics of Fish Swimming

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 1. Fluid Mechanics of Fish Swimming - Lift-based Propulsion. Jaywant H Arakeri. General Article Volume 14 Issue 1 January 2009 pp 32-46. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. Sports Medicine Meets Synchronized Swimming.

    Science.gov (United States)

    Wenz, Betty J.; And Others

    This collection of articles contains information about synchronized swimming. Topics covered include general physiology and cardiovascular conditioning, flexibility exercises, body composition, strength training, nutrition, coach-athlete relationships, coping with competition stress and performance anxiety, and eye care. Chapters are included on…

  18. Fluid Mechanics of Fish Swimming

    Indian Academy of Sciences (India)

    user

    shark). Redrawn from Review of Fish. Swimming Modes for Aquatic. Locomotion, IEEE Journal of. Oceanic Engineering, Vol.24,. No.2, pp. 237–252, 1999, D M. Lane, M Sfakiotakis and J B C. Davies, Heriot-Watt University. undulatory → oscillatory caudaltail¯n (B C F ) m otions are know n collectively as. B C F sw im m ers.

  19. Disentangling the Functional Roles of Morphology and Motion in the Swimming of Fish

    Science.gov (United States)

    Tytell, Eric D.; Borazjani, Iman; Sotiropoulos, Fotis; Baker, T. Vernon; Anderson, Erik J.; Lauder, George V.

    2010-01-01

    In fishes the shape of the body and the swimming mode generally are correlated. Slender-bodied fishes such as eels, lampreys, and many sharks tend to swim in the anguilliform mode, in which much of the body undulates at high amplitude. Fishes with broad tails and a narrow caudal peduncle, in contrast, tend to swim in the carangiform mode, in which the tail undulates at high amplitude. Such fishes also tend to have different wake structures. Carangiform swimmers generally produce two staggered vortices per tail beat and a strong downstream jet, while anguilliform swimmers produce a more complex wake, containing at least two pairs of vortices per tail beat and relatively little downstream flow. Are these differences a result of the different swimming modes or of the different body shapes, or both? Disentangling the functional roles requires a multipronged approach, using experiments on live fishes as well as computational simulations and physical models. We present experimental results from swimming eels (anguilliform), bluegill sunfish (carangiform), and rainbow trout (subcarangiform) that demonstrate differences in the wakes and in swimming performance. The swimming of mackerel and lamprey was also simulated computationally with realistic body shapes and both swimming modes: the normal carangiform mackerel and anguilliform lamprey, then an anguilliform mackerel and carangiform lamprey. The gross structure of simulated wakes (single versus double vortex row) depended strongly on Strouhal number, while body shape influenced the complexity of the vortex row, and the swimming mode had the weakest effect. Performance was affected even by small differences in the wakes: both experimental and computational results indicate that anguilliform swimmers are more efficient at lower swimming speeds, while carangiform swimmers are more efficient at high speed. At high Reynolds number, the lamprey-shaped swimmer produced a more complex wake than the mackerel-shaped swimmer

  20. The Effect of Swimming Experience on Acquisition and Retention of Swimming-Based Taste Aversion Learning in Rats

    Science.gov (United States)

    Masaki, Takahisa; Nakajima, Sadahiko

    2010-01-01

    Swimming endows rats with an aversion to a taste solution consumed before swimming. The present study explored whether the experience of swimming before or after the taste-swimming trials interferes with swimming-based taste aversion learning. Experiment 1 demonstrated that a single preexposure to 20 min of swimming was as effective as four or…

  1. Ordering dynamics in collectively swimming Surf Scoters.

    Science.gov (United States)

    Lukeman, Ryan

    2014-08-21

    One striking feature of collective motion in animal groups is a high degree of alignment among individuals, generating polarized motion. When order is lost, the dynamic process of reorganization, directly resulting from the individual interaction rules, provides significant information about both the nature of the rules, and how these rules affect the functioning of the collective. By analyzing trajectories of collectively swimming Surf Scoters (Melanitta perspicillata) during transitions between order and disorder, I find that individual speed and polarization are positively correlated in time, such that individuals move more slowly in groups exhibiting lower alignment. A previously validated zone-based model framework is used to specify interactions that permit repolarization while maintaining group cohesion and avoiding collisions. Polarization efficiency is optimized under the constraints of cohesion and collision-avoidance for alignment-dominated propulsion (versus autonomous propulsion), and for repulsion an order of magnitude larger than attraction and alignment. The relative strengths of interactions that optimize polarization also quantitatively recover the speed-polarization dependence observed in the data. Parameters determined here through optimizing polarization efficiency are essentially the same as those determined previously from a different approach: a best-fit model for polarized Surf Scoter movement data. The rules governing these flocks are therefore robust, accounting for behavior across a range of order and structure, and also highly responsive to perturbation. Flexibility and efficient repolarization offers an adaptive explanation for why specific interactions in such animal groups are used. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Suspension biomechanics of swimming microbes.

    Science.gov (United States)

    Ishikawa, Takuji

    2009-10-06

    Micro-organisms play a vital role in many biological, medical and engineering phenomena. Some recent research efforts have demonstrated the importance of biomechanics in understanding certain aspects of micro-organism behaviours such as locomotion and collective motions of cells. In particular, spatio-temporal coherent structures found in a bacterial suspension have been the focus of many research studies over the last few years. Recent studies have shown that macroscopic properties of a suspension, such as rheology and diffusion, are strongly affected by meso-scale flow structures generated by swimming microbes. Since the meso-scale flow structures are strongly affected by the interactions between microbes, a bottom-up strategy, i.e. from a cellular level to a continuum suspension level, represents the natural approach to the study of a suspension of swimming microbes. In this paper, we first provide a summary of existing biomechanical research on interactions between a pair of swimming micro-organisms, as a two-body interaction is the simplest many-body interaction. We show that interactions between two nearby swimming micro-organisms are described well by existing mathematical models. Then, collective motions formed by a group of swimming micro-organisms are discussed. We show that some collective motions of micro-organisms, such as coherent structures of bacterial suspensions, are satisfactorily explained by fluid dynamics. Lastly, we discuss how macroscopic suspension properties are changed by the microscopic characteristics of the cell suspension. The fundamental knowledge we present will be useful in obtaining a better understanding of the behaviour of micro-organisms.

  3. Micro- and nanorobots swimming in heterogeneous liquids.

    Science.gov (United States)

    Nelson, Bradley J; Peyer, Kathrin E

    2014-09-23

    Essentially all experimental investigations of swimming micro- and nanorobots have focused on swimming in homogeneous Newtonian liquids. In this issue of ACS Nano, Schamel et al. investigate the actuation of "nanopropellers" in a viscoelastic biological gel that illustrates the importance of the size of the nanostructure relative to the gel mesh size. In this Perspective, we shed further light on the swimming performance of larger microrobots swimming in heterogeneous liquids. One of the interesting results of our work is that earlier findings on the swimming performance of motile bacteria in heterogeneous liquids agree, in principle, with our results. We also discuss future research directions that should be pursued in this fascinating interdisciplinary field.

  4. Significant problems of swimming in Ukraine

    Directory of Open Access Journals (Sweden)

    Kachurovs'kyy D.O.

    2009-12-01

    Full Text Available The variants of decision of problems of swimming are considered in the article. Are presented prognoses of possible results. Complex approach is offered in the decision of the marked problems. Directions are rotined forming for the citizens of vitally important skill of swimming. The variants of decision of problem of teaching swimming of rural population and increase of amount of gettings busy are offered swimming. Traditions of domestic rest are considered in swimming complexes. The ways of increase of level of physical preparation are set student, worker and servicemen.

  5. Effective Propulsion in Swimming: Grasping the Hydrodynamics of Hand and Arm Movements.

    Science.gov (United States)

    van Houwelingen, Josje; Schreven, Sander; Smeets, Jeroen B J; Clercx, Herman J H; Beek, Peter J

    2017-02-01

    In this paper, a literature review is presented regarding the hydrodynamic effects of different hand and arm movements during swimming with the aim to identify lacunae in current methods and knowledge, and to distil practical guidelines for coaches and swimmers seeking to increase swimming speed. Experimental and numerical studies are discussed, examining the effects of hand orientation, thumb position, finger spread, sculling movements, and hand accelerations during swimming, as well as unsteady properties of vortices due to changes in hand orientation. Collectively, the findings indicate that swimming speed may be increased by avoiding excessive sculling movements and by spreading the fingers slightly. In addition, it appears that accelerating the hands rather than moving them at constant speed may be beneficial, and that (in front crawl swimming) the thumb should be abducted during entry, catch, and upsweep, and adducted during the pull phase. Further experimental and numerical research is required to confirm these suggestions and to elucidate their hydrodynamic underpinnings and identify optimal propulsion techniques. To this end, it is necessary that the dynamical motion and resulting unsteady effects are accounted for, and that flow visualization techniques, force measurements, and simulations are combined in studying those effects.

  6. Characterisation of the swimming muscles of two Subantarctic notothenoids

    Directory of Open Access Journals (Sweden)

    Daniel Alfredo Fernández

    1999-12-01

    Full Text Available The histochemical characteristics and distribution of muscle fibre types have been investigated in the swimming muscles of the róbalo, Eleginops maclovinus and the lorcho, Patagonotothen tessellata, Subantarctic notothenioids that inhabit the Beagle Channel. The fibre types were differentiated on the basis of glycogen and lipid contents and succinate dehydrogenase and myofibrillar ATPase (mATPase activities. White, red, intermediate and tonic fibres were present in the axial muscle of both species. The same fibre types were identified in the pectoral fin adductor muscles, although the intermediate type was absent. The mATPase technique performed at room temperature (21ºC allowed a good differentiation of fibre types, overcoming the problems found by previous researchers when applying this technique to Antarctic notothenioids. Four different zones (peripheral, mosaic, main and adjacent to the bone were found in the adductor profundis muscle. The proportion of the zones varied along the length of the adductor muscle. For both species, the percentage of red fibres found in the axial muscles was less than 5%, indicating that sustained swimming ability is not dependent on these muscles. The pectoral muscle mass/carcase mass ratio was significantly greater in E. maclovinus than in P. tessellata, reflecting a greater capacity for sustained swimming using pectoral fins.

  7. Digesting or swimming? Integration of the postprandial metabolism, behavior and locomotion in a frequently foraging fish.

    Science.gov (United States)

    Nie, Li-Juan; Cao, Zhen-Dong; Fu, Shi-Jian

    2017-02-01

    Fish that are active foragers usually perform routine activities while digesting their food; thus, their postprandial swimming capacity and related behavior adjustments might be ecologically important. To test whether digestion affect swimming performance and the relationships of digestion with metabolism and behavior in an active forager, we investigated the postprandial metabolic response, spontaneous swimming activities, critical swimming speed (Ucrit), and fast-start escape performance of both fasted and digesting (3h after feeding to satiation) juvenile rose bitterling (Rhodeus ocellatus). Feeding to satiation elicited a 50% increase in the oxygen consumption rate, which peaked at 3h after feeding and returned to the prefeeding state after another 3h. However, approximately 50% and 90% of individuals resumed feeding behavior at 2 and 3h postfeeding, respectively, although the meal size varied substantially. Digestion showed no effect on either steady swimming performance as suggested by the Ucrit or unsteady swimming performance indicated by the maximum linear velocity in fast-start escape movement. However, digesting fish showed more spontaneous activity as indicated by the longer total distance traveled, mainly through an increased percentage of time spent moving (PTM). A further analysis found that fasting individuals with high swimming speed were more inclined to increase their PTM during digestive processes. The present study suggests that as an active forager With a small meal size and hence limited postprandial physiological and morphological changes, the swimming performance of rose bitterling is maintained during digestion, which might be crucial for its active foraging mode and anti-predation strategy. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Pre-task music improves swimming performance.

    Science.gov (United States)

    Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

    2015-12-01

    The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

  9. The ontogenetic scaling of hydrodynamics and swimming performance in jellyfish (Aurelia aurita).

    Science.gov (United States)

    McHenry, Matthew J; Jed, Jason

    2003-11-01

    It is not well understood how ontogenetic changes in the motion and morphology of aquatic animals influence the performance of swimming. The goals of the present study were to understand how changes in size, shape and behavior affect the hydrodynamics of jet propulsion in the jellyfish Aurelia aurita and to explore how such changes affect the ontogenetic scaling of swimming speed and cost of transport. We measured the kinematics of jellyfish swimming from video recordings and simulated the hydrodynamics of swimming with two computational models that calculated thrust generation by paddle and jet mechanisms. Our results suggest that thrust is generated primarily by jetting and that there is negligible thrust generation by paddling. We examined how fluid forces scaled with body mass using the jet model. Despite an ontogenetic increase in the range of motion by the bell diameter and a decrease in the height-to-diameter ratio, we found that thrust and acceleration reaction scaled with body mass as predicted by kinematic similarity. However, jellyfish decreased their pulse frequency with growth, and speed consequently scaled at a lower exponential rate than predicted by kinematic similarity. Model simulations suggest that the allometric growth in Aurelia results in swimming that is slower, but more energetically economical, than isometric growth with a prolate bell shape. The decrease in pulse frequency over ontogeny allows large Aurelia medusae to avoid a high cost of transport but generates slower swimming than if they maintained a high pulse frequency. Our findings suggest that ontogenetic change in the height-to-diameter ratio and pulse frequency of Aurelia results in swimming that is relatively moderate in speed but is energetically economical.

  10. Experimental Studies and Dynamics Modeling Analysis of the Swimming and Diving of Whirligig Beetles (Coleoptera: Gyrinidae)

    Science.gov (United States)

    Jia, Xinghua; Zhang, Mingjun

    2012-01-01

    Whirligig beetles (Coleoptera, Gyrinidae) can fly through the air, swiftly swim on the surface of water, and quickly dive across the air-water interface. The propulsive efficiency of the species is believed to be one of the highest measured for a thrust generating apparatus within the animal kingdom. The goals of this research were to understand the distinctive biological mechanisms that allow the beetles to swim and dive, while searching for potential bio-inspired robotics applications. Through static and dynamic measurements obtained using a combination of microscopy and high-speed imaging, parameters associated with the morphology and beating kinematics of the whirligig beetle's legs in swimming and diving were obtained. Using data obtained from these experiments, dynamics models of both swimming and diving were developed. Through analysis of simulations conducted using these models it was possible to determine several key principles associated with the swimming and diving processes. First, we determined that curved swimming trajectories were more energy efficient than linear trajectories, which explains why they are more often observed in nature. Second, we concluded that the hind legs were able to propel the beetle farther than the middle legs, and also that the hind legs were able to generate a larger angular velocity than the middle legs. However, analysis of circular swimming trajectories showed that the middle legs were important in maintaining stable trajectories, and thus were necessary for steering. Finally, we discovered that in order for the beetle to transition from swimming to diving, the legs must change the plane in which they beat, which provides the force required to alter the tilt angle of the body necessary to break the surface tension of water. We have further examined how the principles learned from this study may be applied to the design of bio-inspired swimming/diving robots. PMID:23209398

  11. Swim performance and thermoregulatory effects of wearing clothing in a simulated cold-water survival situation.

    Science.gov (United States)

    Bowes, Heather; Eglin, Clare M; Tipton, Michael J; Barwood, Martin J

    2016-04-01

    Accidental cold-water immersion (CWI) impairs swim performance, increases drowning risk and often occurs whilst clothed. The impact of clothing on thermoregulation and swim performance during CWI was explored with the view of making recommendations on whether swimming is viable for self-rescue; contrary to the traditional recommendations. Ten unhabituated males (age 24 (4) years; height 1.80 (0.08) m; mass 78.50 (10.93) kg; body composition 14.8 (3.4) fat %) completed four separate CWIs in 12 °C water. They either rested clothed or naked (i.e. wearing a bathing costume) or swum self-paced clothed or naked for up to 1 h. Swim speed, distance covered, oxygen consumption and thermal responses (rectal temperature (T re), mean skin temperature (T msk) and mean body temperature T b) were measured. When clothed, participants swum at a slower pace and for a significantly shorter distance (815 (482) m, 39 (19) min) compared to when naked (1264 (564) m, 52 (18) min), but had a similar oxygen consumption indicating clothing made them less efficient. Swimming accelerated the rate of T msk and T b cooling and wearing clothing partially attenuated this drop. The impairment to swimming performance caused by clothing was greater than the thermal benefit it provided; participants withdrew due to exhaustion before hypothermia developed. Swimming is a viable self-rescue method in 12 °C water, however, clothing impairs swimming capability. Self-rescue swimming could be considered before clinical hypothermia sets in for the majority of individuals. These suggestions must be tested for the wider population.

  12. Effects of feeding, digestion and fasting on the respiration and swimming capability of juvenile sterlet sturgeon (Acipenser ruthenus, Linnaeus 1758).

    Science.gov (United States)

    Cai, Lu; Johnson, David; Fang, Min; Mandal, Prashant; Tu, Zhiying; Huang, Yingping

    2017-02-01

    The objective of this study is to provide information on changes in swimming capability and respiration of the sterlet sturgeon (Acipenser ruthenus, Linnaeus 1758) caused by different levels of fasting. Before testing, the four groups of sturgeon (body length: 12.1-15.4 cm, body mass: 10.0-20.2 g) fasted for 6 h, 2 days, 1 and 2 weeks, respectively. Swimming tests were then performed to measure critical swimming speed and oxygen consumption at 20 ± 0.5 °C. Results show: (1) Fasting times shorter than 2 days has little effect on swimming capability, but it decreases significantly when the fasting time is longer than a week. (2) After 2 weeks of fasting, swimming efficiency is significantly reduced. (3) Anaerobic capacity increases when digestion nears completion.

  13. Hydrokinetic turbine effects on fish swimming behaviour.

    Directory of Open Access Journals (Sweden)

    Linus Hammar

    Full Text Available Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their movements through the area when the rotor was present. This deterrent effect on fish increased with current speed. Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms(-1. The effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish movements, particularly for large species, with possible effects on habitat connectivity if migration routes are exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of several metres width to allow large fish to pass through. In combination with further research the insights from this study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological impacts.

  14. Hydrokinetic turbine effects on fish swimming behaviour.

    Science.gov (United States)

    Hammar, Linus; Andersson, Sandra; Eggertsen, Linda; Haglund, Johan; Gullström, Martin; Ehnberg, Jimmy; Molander, Sverker

    2013-01-01

    Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their movements through the area when the rotor was present. This deterrent effect on fish increased with current speed. Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms(-1). The effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish movements, particularly for large species, with possible effects on habitat connectivity if migration routes are exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of several metres width to allow large fish to pass through. In combination with further research the insights from this study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological impacts.

  15. Flagellar Kinematics and Swimming of Algal Cells in Viscoelastic Fluids

    Science.gov (United States)

    Qin, B.; Gopinath, A.; Yang, J.; Gollub, J. P.; Arratia, P. E.

    2015-03-01

    The motility of microorganisms is influenced greatly by their hydrodynamic interactions with the fluidic environment they inhabit. We show by direct experimental observation of the bi-flagellated alga Chlamydomonas reinhardtii that fluid elasticity and viscosity strongly influence the beating pattern - the gait - and thereby control the propulsion speed. The beating frequency and the wave speed characterizing the cyclical bending are both enhanced by fluid elasticity. Despite these enhancements, the net swimming speed of the alga is hindered for fluids that are sufficiently elastic. The origin of this complex response lies in the interplay between the elasticity-induced changes in the spatial and temporal aspects of the flagellar cycle and the buildup and subsequent relaxation of elastic stresses during the power and recovery strokes.

  16. Swimming physiology of European silver eels (Anguilla anguilla L.): energetic costs and effects on sexual maturation and reproduction

    Science.gov (United States)

    van den Thillart, Guido E. E. J. M.

    2010-01-01

    The European eel migrates 5,000–6,000 km to the Sargasso Sea to reproduce. Because they venture into the ocean in a pre-pubertal state and reproduce after swimming for months, a strong interaction between swimming and sexual maturation is expected. Many swimming trials have been performed in 22 swim tunnels to elucidate their performance and the impact on maturation. European eels are able to swim long distances at a cost of 10–12 mg fat/km which is 4–6 times more efficient than salmonids. The total energy costs of reproduction correspond to 67% of the fat stores. During long distance swimming, the body composition stays the same showing that energy consumption calculations cannot be based on fat alone but need to be compensated for protein oxidation. The optimal swimming speed is 0.61–0.67 m s−1, which is ~60% higher than the generally assumed cruise speed of 0.4 m s−1 and implies that female eels may reach the Sargasso Sea within 3.5 months instead of the assumed 6 months. Swimming trials showed lipid deposition and oocyte growth, which are the first steps of sexual maturation. To investigate effects of oceanic migration on maturation, we simulated group-wise migration in a large swim-gutter with seawater. These trials showed suppressed gonadotropin expression and vitellogenesis in females, while in contrast continued sexual maturation was observed in silver males. The induction of lipid deposition in the oocytes and the inhibition of vitellogenesis by swimming in females suggest a natural sequence of events quite different from artificial maturation protocols. PMID:20390348

  17. Paramecium swimming in capillary tube

    CERN Document Server

    Jana, Saikat; Jung, Sunghwan

    2010-01-01

    Swimming organisms in their natural habitat navigate through a wide array of geometries and chemical environments. Interaction with the boundaries is ubiquitous and can significantly modify the swimming characteristics of the organism as observed under ideal conditions. We study the dynamics of ciliary locomotion in Paramecium multimicronucleatum and observe the effect of the solid boundaries on the velocities in the near field of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight line motion as the diameter of the capillary tubes decrease. Theoretically this system is modeled as an undulating cylinder with pressure gradient and compared with experiments; showing that such considerations are necessary for modeling finite sized organisms in the restrictive geometries.

  18. Can polish university female students swim?

    Directory of Open Access Journals (Sweden)

    Podstawski Robert

    2013-06-01

    Full Text Available Background and aim of the work: There are only few studies in Polish and foreign literature providing solid information on swimming skills of university students. The aim of the study carried out at the University of Warmia & Mazury in Olsztyn was to determine swimming skills of Polish university female students starting their studies. Material and methods: The study was conducted in 2012 on 298 female students of the 1 st year course, at the age of 19 – 20. Anonymous questionnaire was used in the research. Results: It has been shown that almost 72% of the women could not swim at all, and 26% swam poorly. Within the group of women able to swim, the greatest percentage was set by women using classical style (49% and “their own” one (27% and only 13% of the students used crawl, 9% - back stroke and 2% - butterfly style. Of all the women declaring swimming abilities, the biggest percentage (16% could cover the distance of only 20 – 50 m; fewer students (6% covered the distance of 50 – 100 m; and 5% could swim only 20 m. Only a marginal number of students (2% could cover the distance from 100 to 1000 m; none could swim more than 1000 m. Conclusions: The study showed a very pessimistic picture of swimming skills of Polish university female students in respect of the number of women able to swim, their knowledge of swimming styles, and the length of the covered distance.

  19. Cetacean Swimming with Prosthetic Limbs

    Science.gov (United States)

    Bode-Oke, Ayodeji; Ren, Yan; Dong, Haibo; Fish, Frank

    2016-11-01

    During entanglement in fishing gear, dolphins can suffer abrasions and amputations of flukes and fins. As a result, if the dolphin survives the ordeal, swimming performance is altered. Current rehabilitation technques is the use of prosthesis to regain swimming ability. In this work, analyses are focused on two dolphins with locomotive impairment; Winter (currently living in Clearwater Marine Aquarium in Florida) and Fuji (lived in Okinawa Churaumi Aquarium in Japan). Fuji lost about 75% of its fluke surface to necrosis (death of cells) and Winter lost its tail due to amputation. Both dolphins are aided by prosthetic tails that mimic the shape of a real dolphin tail. Using 3D surface reconstruction techniques and a high fidelity Computational Fluid Dynamics (CFD) flow solver, we were able to elucidate the kinematics and hydrodynamics and fluke deformation of these swimmers to clarify the effectiveness of prostheses in helping the dolphins regain their swimming ability. Associated with the performance, we identified distinct features in the wake structures that can explain this gap in the performance compared to a healthy dolphin. This work was supported by ONR MURI Grant Number N00014-14-1-0533.

  20. Whole-field visual motion drives swimming in larval zebrafish via a stochastic process.

    Science.gov (United States)

    Portugues, Ruben; Haesemeyer, Martin; Blum, Mirella L; Engert, Florian

    2015-05-01

    Caudo-rostral whole-field visual motion elicits forward locomotion in many organisms, including larval zebrafish. Here, we investigate the dependence on the latency to initiate this forward swimming as a function of the speed of the visual motion. We show that latency is highly dependent on speed for slow speeds (1.5 s, which is much longer than neuronal transduction processes. What mechanisms underlie these long latencies? We propose two alternative, biologically inspired models that could account for this latency to initiate swimming: an integrate and fire model, which is history dependent, and a stochastic Poisson model, which has no history dependence. We use these models to predict the behavior of larvae when presented with whole-field motion of varying speed and find that the stochastic process shows better agreement with the experimental data. Finally, we discuss possible neuronal implementations of these models. © 2015. Published by The Company of Biologists Ltd.

  1. The Effect of Drag and Attachment Site of External Tags on Swimming Eels: Experimental Quantification and Evaluation Tool

    Science.gov (United States)

    Tudorache, Christian; Burgerhout, Erik; Brittijn, Sebastiaan; van den Thillart, Guido

    2014-01-01

    Telemetry studies on aquatic animals often use external tags to monitor migration patterns and help to inform conservation effort. However, external tags are known to impair swimming energetics dramatically in a variety of species, including the endangered European eel. Due to their high swimming efficiency, anguilliform swimmers are very susceptibility for added drag. Using an integration of swimming physiology, behaviour and kinematics, we investigated the effect of additional drag and site of externally attached tags on swimming mode and costs. The results show a significant effect of a) attachment site and b) drag on multiple energetic parameters, such as Cost Of Transport (COT), critical swimming speed (Ucrit) and optimal swimming speed (Uopt), possibly due to changes in swimming kinematics. Attachment at 0.125 bl from the tip of the snout is a better choice than at the Centre Of Mass (0.35 bl), as it is the case in current telemetry studies. Quantification of added drag effect on COT and Ucrit show a (limited) correlation, suggesting that the Ucrit test can be used for evaluating external tags for telemetry studies until a certain threshold value. Uopt is not affected by added drag, validating previous findings of telemetry studies. The integrative methodology and the evaluation tool presented here can be used for the design of new studies using external telemetry tags, and the (re-) evaluation of relevant studies on anguilliform swimmers. PMID:25409179

  2. The effect of drag and attachment site of external tags on swimming eels: experimental quantification and evaluation tool.

    Science.gov (United States)

    Tudorache, Christian; Burgerhout, Erik; Brittijn, Sebastiaan; van den Thillart, Guido

    2014-01-01

    Telemetry studies on aquatic animals often use external tags to monitor migration patterns and help to inform conservation effort. However, external tags are known to impair swimming energetics dramatically in a variety of species, including the endangered European eel. Due to their high swimming efficiency, anguilliform swimmers are very susceptibility for added drag. Using an integration of swimming physiology, behaviour and kinematics, we investigated the effect of additional drag and site of externally attached tags on swimming mode and costs. The results show a significant effect of a) attachment site and b) drag on multiple energetic parameters, such as Cost Of Transport (COT), critical swimming speed (Ucrit) and optimal swimming speed (Uopt), possibly due to changes in swimming kinematics. Attachment at 0.125 bl from the tip of the snout is a better choice than at the Centre Of Mass (0.35 bl), as it is the case in current telemetry studies. Quantification of added drag effect on COT and Ucrit show a (limited) correlation, suggesting that the Ucrit test can be used for evaluating external tags for telemetry studies until a certain threshold value. Uopt is not affected by added drag, validating previous findings of telemetry studies. The integrative methodology and the evaluation tool presented here can be used for the design of new studies using external telemetry tags, and the (re-) evaluation of relevant studies on anguilliform swimmers.

  3. The effect of drag and attachment site of external tags on swimming eels: experimental quantification and evaluation tool.

    Directory of Open Access Journals (Sweden)

    Christian Tudorache

    Full Text Available Telemetry studies on aquatic animals often use external tags to monitor migration patterns and help to inform conservation effort. However, external tags are known to impair swimming energetics dramatically in a variety of species, including the endangered European eel. Due to their high swimming efficiency, anguilliform swimmers are very susceptibility for added drag. Using an integration of swimming physiology, behaviour and kinematics, we investigated the effect of additional drag and site of externally attached tags on swimming mode and costs. The results show a significant effect of a attachment site and b drag on multiple energetic parameters, such as Cost Of Transport (COT, critical swimming speed (Ucrit and optimal swimming speed (Uopt, possibly due to changes in swimming kinematics. Attachment at 0.125 bl from the tip of the snout is a better choice than at the Centre Of Mass (0.35 bl, as it is the case in current telemetry studies. Quantification of added drag effect on COT and Ucrit show a (limited correlation, suggesting that the Ucrit test can be used for evaluating external tags for telemetry studies until a certain threshold value. Uopt is not affected by added drag, validating previous findings of telemetry studies. The integrative methodology and the evaluation tool presented here can be used for the design of new studies using external telemetry tags, and the (re- evaluation of relevant studies on anguilliform swimmers.

  4. VARIABILITY OF COORDINATION PARAMETERS AT 400-M FRONT CRAWL SWIMMING PACE

    Directory of Open Access Journals (Sweden)

    Christophe Schnitzler

    2009-06-01

    Full Text Available This study examined the variability of physiological, perceptual, stroke and coordination parameters in both genders during several swim trials at the 400-m pace speed. Twelve national level competitors (6 men, 6 women swam 400-m at maximal speed. They then swam three additional trials (100, 200 and 300-m at the pace (speed of the previous 400-m. Three cameras were used to determine stroke cycle [speed (V, stroke length (SL, stroke rate (SR] and coordination [index of coordination (IdC, stroke phases] parameters. Physiological [heart rate (HR and lactate [La-] and perceptual [subjective workload (TWL] parameters were assessed after each swim trial. Inter-trial data indicated that HR, [La-] and TWL increased significantly with the distance swum (p 0.05. Thus, despite changes in both physiological and perceptual responses consecutive to increasing fatigue, coordination parameters remained stable during an all-out 400-m freestyle swim. The examination of these parameters based on short-distance trials appears then to be valid, which offers interesting perspectives for swim testing.

  5. Partition of aerobic and anaerobic swimming costs and their correlation to tail-beat frequency and burst activity in Sparus aurata

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2012-01-01

    until fatigue at 10°C. The anaerobic swimming cost was measured as the excess postexercise oxygen consumption (EPOC) following each swimming speed. To determine tail-beat frequency, amplitude and burst and coast behaviour, the peduncle position was determined at 25 s·' by video tracking. The data showed......, and resulted in a total anaerobic capacity of 170 mg O2 kg·'. Normalized tail-beat amplitude and frequency both predicted the swimming speed but only tail-beat frequency was able to predict the aerobic swimming cost. The change to burst and coast swimming was correlated to the first measurements of EPOC...... and both the burst frequency (bursts min·') and burst distance (percentage burst distance) were found to predict EPOC by linear regressions. The low temperature used in the present study resulted in a prolonged recovery time, which increased with the anaerobic contribution to 10 hours after fatigue. Due...

  6. Sodium-coupled motility in a swimming cyanobacterium.

    OpenAIRE

    Willey, J M; Waterbury, J B; Greenberg, E P

    1987-01-01

    The energetics of motility in Synechococcus strain WH8113 were studied to understand the unique nonflagellar swimming of this cyanobacterium. There was a specific sodium requirement for motility such that cells were immotile below 10 mM external sodium and cell speed increased with increasing sodium levels above 10 mM to a maximum of about 15 microns/s at 150 to 250 mM sodium. The sodium motive force increased similarly with increasing external sodium from -120 to -165 mV, but other energetic...

  7. Scaling in Free-Swimming Fish and Implications for Measuring Size-at-Time in the Wild

    Science.gov (United States)

    Broell, Franziska; Taggart, Christopher T.

    2015-01-01

    This study was motivated by the need to measure size-at-age, and thus growth rate, in fish in the wild. We postulated that this could be achieved using accelerometer tags based first on early isometric scaling models that hypothesize that similar animals should move at the same speed with a stroke frequency that scales with length-1, and second on observations that the speed of primarily air-breathing free-swimming animals, presumably swimming ‘efficiently’, is independent of size, confirming that stroke frequency scales as length-1. However, such scaling relations between size and swimming parameters for fish remain mostly theoretical. Based on free-swimming saithe and sturgeon tagged with accelerometers, we introduce a species-specific scaling relationship between dominant tail beat frequency (TBF) and fork length. Dominant TBF was proportional to length-1 (r2 = 0.73, n = 40), and estimated swimming speed within species was independent of length. Similar scaling relations accrued in relation to body mass-0.29. We demonstrate that the dominant TBF can be used to estimate size-at-time and that accelerometer tags with onboard processing may be able to provide size-at-time estimates among free-swimming fish and thus the estimation of growth rate (change in size-at-time) in the wild. PMID:26673777

  8. Helicobacter pylori displays spiral trajectories while swimming like a cork-screw in solutions

    Science.gov (United States)

    Constantino, Maira A.; Hardcastle, Joseph M.; Bansil, Rama; Jabbarzadeh, Mehdi; Fu, Henry C.

    Helicobacter pylori is a helical shaped bacterium that causes gastritis, ulcers and gastric cancer in humans and other animals. In order to colonize the harsh acidic environment of the stomach H. pylori has evolved a unique biochemical mechanism to go across the viscoelastic gel-like gastric mucus layer. Many studies have been conducted on the swimming of H. pylori in viscous media. However a yet unanswered question is if the helical cell shape influences bacterial swimming dynamics or confers any advantage when swimming in viscous solution. We will present measurements of H. pylori trajectories displaying corkscrew motion while swimming in solution obtained by tracking single cells using 2-dimensional phase contrast imaging at high magnification and fast frame rates and simultaneously imaging their shape. We observe a linear relationship between swimming speed and rotation rate. The experimental trajectories show good agreement with trajectories calculated using a regularized Stokeslet method to model the low Reynolds number swimming behavior. Supported by NSF PHY 1410798 (PI: RB).

  9. Kinematics and energetics of swimming performance during acute warming in brown trout Salmo trutta.

    Science.gov (United States)

    Lea, J M D; Keen, A N; Nudds, R L; Shiels, H A

    2016-01-01

    This study examined how acute warming of water temperature affects the mechanical efficiency of swimming and aerobic capabilities of the brown trout Salmo trutta. Swimming efficiency was assessed using the relationship between swimming kinematics and forward speed (U), which is thought to converge upon an optimum range of a dimensionless parameter, the Strouhal number (St ). Swim-tunnel intermittent stopped-flow respirometry was used to record kinematics and measure oxygen consumption (ṀO2) of S. trutta during warming and swimming challenges. Salmo trutta maintained St between 0·2 and 0·3 at any given U over a range of temperatures, irrespective of body size. The maintenance of St within the range for maximum efficiency for oscillatory propulsion was achieved through an increase in tail-beat frequency (ftail) and a decrease in tail-beat amplitude (A) as temperature increased. Maintenance of efficient steady-state swimming was fuelled by aerobic metabolism, which increased as temperature increased up to 18° C but declined above this temperature, decreasing the apparent metabolic scope. As St was maintained over the full range of temperatures whilst metabolic scope was not, the results may suggest energetic trade-offs at any given U at temperatures above thermal optima. © 2015 The Fisheries Society of the British Isles.

  10. Developmental changes in head movement kinematics during swimming in Xenopus laevis tadpoles.

    Science.gov (United States)

    Hänzi, Sara; Straka, Hans

    2017-01-15

    During the post-embryonic developmental growth of animals, a number of physiological parameters such as locomotor performance, dynamics and behavioural repertoire are adjusted to match the requirements determined by changes in body size, proportions and shape. Moreover, changes in movement parameters also cause changes in the dynamics of self-generated sensory stimuli, to which motion-detecting sensory systems have to adapt. Here, we examined head movements and swimming kinematics of Xenopus laevis tadpoles with a body length of 10-45 mm (developmental stage 46-54) and compared these parameters with fictive swimming, recorded as ventral root activity in semi-intact in vitro preparations. Head movement kinematics was extracted from high-speed video recordings of freely swimming tadpoles. Analysis of these locomotor episodes indicated that the swimming frequency decreased with development, along with the angular velocity and acceleration of the head, which represent self-generated vestibular stimuli. In contrast, neither head oscillation amplitude nor forward velocity changed with development despite the ∼3-fold increase in body size. The comparison between free and fictive locomotor dynamics revealed very similar swimming frequencies for similarly sized animals, including a comparable developmental decrease of the swimming frequency. Body morphology and the motor output rhythm of the spinal central pattern generator therefore develop concurrently. This study thus describes development-specific naturalistic head motion profiles, which form the basis for more natural stimuli in future studies probing the vestibular system. © 2017. Published by The Company of Biologists Ltd.

  11. Concentration-dependent toxicity effect of SDBS on swimming behavior of freshwater fishes.

    Science.gov (United States)

    Zhang, Ying; Ma, Jing; Zhou, Siyun; Ma, Fang

    2015-07-01

    Sodium dodecyl benzene sulfonate (SDBS) is a kind of widely used anionic surfactant and its discharge may pose potential risk to the receiving aquatic ecosystem. The aim of our study is to investigate the toxic effect of SDBS on fish swimming behavior quantitatively, followed by examination whether there are significant differences of swimming behavior among applied fish species (i.e. zebra fish (Danio rerio), Japanese medaka (Oryzias latipes) and red carp (Cyprinus carpio)). The swimming speed and vertical position were analyzed after the fish exposed to SDBS aiming to reflect the toxicity of SDBS on fish. Our results showed that the swimming behavior of three fishes was significantly affected by SDBS, although there were slight differences of swimming pattern changes among three fish species when they exposed to the same concentration of SDBS. It could be seen that red carp, one of the native fish species in China, can be used as a model fish to reflect the water quality changes as well as zebra fish and Japanese medaka which are commonly used as model fishes. Our study also illustrated that the swimming behavior monitoring may have a good application prospect in pre-warning of water quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Current Methodologies in Baby and Infant Swimming

    OpenAIRE

    Boldišová, Šárka

    2009-01-01

    Thesis describes history of infant a baby swimming in Czech republic and worlwide. It brings an overview of current methods and methodologies of infant a baby swimming worlwide and in the Czech republic. Thesis describes in a reasonable detail methodology, developed by BabyClub Plaváček. Second - practical part of the thesis tries to evaluate hypothesis concerning methodologies used in infant and baby swimming. Evaluation is done upon questionaries and their evaluation. This thesis describes ...

  13. Kinematical Analysis along Maximal Lactate Steady State Swimming Intensity

    Directory of Open Access Journals (Sweden)

    Pedro Figueiredo, Rafael Nazario, Marisa Sousa, Jailton Gregório Pelarigo, João Paulo Vilas-Boas, Ricardo Fernandes

    2014-09-01

    Full Text Available The purpose of this study was to conduct a kinematical analysis during swimming at the intensity corresponding to maximal lactate steady state (MLSS. Thirteen long distance swimmers performed, in different days, an intermittent incremental protocol of n x 200 m until exhaustion and two to four 30-min submaximal constant speed bouts to determine the MLSS. The video analysis, using APAS System (Ariel Dynamics Inc., USA, allowed determining the following relevant swimming determinants (in five moments of the 30-min test: 0, 25, 50, 75, and 100%: stroke rate, stroke length, trunk incline, intracyclic velocity variation, propelling efficiency, index of coordination and the time allotted to propulsion per distance unit. An ANOVA for repeated measures was used to compare the parameters mean values along each moment of analysis. Stoke rate tended to increase and stroke length to decrease along the test; a tendency to decrease was also found for intracyclic velocity variation and propelling efficiency whereas the index of coordination and the propulsive impulse remained stable during the MLSS test. It can be concluded that the MLSS is not only an intensity to maintain without a significant increase of blood lactate concentration, but a concomitant stability for some biomechanical parameters exists (after an initial adaptation. However, efficiency indicators seem to be more sensitive to changes occurring during swimming at this threshold intensity.

  14. Ciliary contact interactions dominate surface scattering of swimming eukaryotes.

    Science.gov (United States)

    Kantsler, Vasily; Dunkel, Jörn; Polin, Marco; Goldstein, Raymond E

    2013-01-22

    Interactions between swimming cells and surfaces are essential to many microbiological processes, from bacterial biofilm formation to human fertilization. However, despite their fundamental importance, relatively little is known about the physical mechanisms that govern the scattering of flagellated or ciliated cells from solid surfaces. A more detailed understanding of these interactions promises not only new biological insights into structure and dynamics of flagella and cilia but may also lead to new microfluidic techniques for controlling cell motility and microbial locomotion, with potential applications ranging from diagnostic tools to therapeutic protein synthesis and photosynthetic biofuel production. Due to fundamental differences in physiology and swimming strategies, it is an open question of whether microfluidic transport and rectification schemes that have recently been demonstrated for pusher-type microswimmers such as bacteria and sperm cells, can be transferred to puller-type algae and other motile eukaryotes, because it is not known whether long-range hydrodynamic or short-range mechanical forces dominate the surface interactions of these microorganisms. Here, using high-speed microscopic imaging, we present direct experimental evidence that the surface scattering of both mammalian sperm cells and unicellular green algae is primarily governed by direct ciliary contact interactions. Building on this insight, we predict and experimentally verify the existence of optimal microfluidic ratchets that maximize rectification of initially uniform Chlamydomonas reinhardtii suspensions. Because mechano-elastic properties of cilia are conserved across eukaryotic species, we expect that our results apply to a wide range of swimming microorganisms.

  15. A swimming robot actuated by living muscle tissue

    Directory of Open Access Journals (Sweden)

    Herr Hugh

    2004-10-01

    Full Text Available Abstract Biomechatronics is the integration of biological components with artificial devices, in which the biological component confers a significant functional capability to the system, and the artificial component provides specific cellular and tissue interfaces that promote the maintenance and functional adaptation of the biological component. Based upon functional performance, muscle is potentially an excellent mechanical actuator, but the larger challenge of developing muscle-actuated, biomechatronic devices poses many scientific and engineering challenges. As a demonstratory proof of concept, we designed, built, and characterized a swimming robot actuated by two explanted frog semitendinosus muscles and controlled by an embedded microcontroller. Using open loop stimulation protocols, the robot performed basic swimming maneuvers such as starting, stopping, turning (turning radius ~400 mm and straight-line swimming (max speed >1/3 body lengths/second. A broad spectrum antibiotic/antimycotic ringer solution surrounded the muscle actuators for long term maintenance, ex vivo. The robot swam for a total of 4 hours over a 42 hour lifespan (10% duty cycle before its velocity degraded below 75% of its maximum. The development of functional biomechatronic prototypes with integrated musculoskeletal tissues is the first critical step toward the long term objective of controllable, adaptive and robust biomechatronic robots and prostheses.

  16. Anomalous swimming behavior of bacteria in nematic liquid crystals

    Science.gov (United States)

    Sokolov, Andrey; Zhou, Shuang; Lavrentovich, Oleg; Aranson, Igor

    2015-03-01

    Flagellated bacteria stop swimming in isotropic media of viscosity higher than 0.06kgm-1s-1. However, Bacillus Subtilis slows down by only about 30% in a nematic chromonic liquid crystal (CLC, 14wt% DSCG in water), where the anisotropic viscosity can be as high as 6kgm-1s-1. The bacteria velocity (Vb) is linear with the flagella rotation frequency. The phase velocity of the flagella Vf ~ 2Vb in LC, as compared to Vf ~ 10Vb in water. The flow generated by the bacteria is localized along the bacterial body axis, decaying slowly over tens of micrometers along, but rapidly over a few micrometers across this axis. The concentrated flow grants the bacteria new ability to carry cargo particles in LC, ability not seen in their habitat isotropic media. We attribute these anomalous features to the anisotropy of viscosity of the CLC, namely, the viscosities of splay and twist is hundreds times higher than that of bend deformation, which provides extra boost of swimming efficiency and enables the bacteria swim at considerable speed in a viscous medium. Our findings can potentially lead to applications such as particle transportation in microfluidic devices. A.S and I.A are supported by the US DOE, Office of Science, BES, Materials Science and Engineering Division. S.Z. and O.D.L are supported by NSF DMR 1104850, DMS-1434185.

  17. Fluid mechanics of swimming bacteria with multiple flagella.

    Science.gov (United States)

    Kanehl, Philipp; Ishikawa, Takuji

    2014-04-01

    It is known that some kinds of bacteria swim by forming a bundle of their multiple flagella. However, the details of flagella synchronization as well as the swimming efficiency of such bacteria have not been fully understood. In this study, swimming of multiflagellated bacteria is investigated numerically by the boundary element method. We assume that the cell body is a rigid ellipsoid and the flagella are rigid helices suspended on flexible hooks. Motors apply constant torque to the hooks, rotating the flagella either clockwise or counterclockwise. Rotating all flagella clockwise, bundling of all flagella is observed in every simulated case. It is demonstrated that the counter rotation of the body speeds up the bundling process. During this procedure the flagella synchronize due to hydrodynamic interactions. Moreover, the results illustrated that during running the multiflagellated bacterium shows higher propulsive efficiency (distance traveled per one flagellar rotation) over a bacterium with a single thick helix. With an increasing number of flagella the propulsive efficiency increases, whereas the energetic efficiency decreases, which indicates that efficiency is something multiflagellated bacteria are assigning less priority to than to motility. These findings form a fundamental basis in understanding bacterial physiology and metabolism.

  18. Partition of aerobic and anaerobic swimming costs related to gait transitions in a labriform fish

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Tudorache, Christian; Jordan, Anders Drud

    ) is below the Up-c, whereas both 1.9 and 2.3 bl s-1 are above the Up-c. Exercise oxygen consumption (MO2) while the fish were swimming at these speeds was determined. The presence and magnitude of excessive post exercise oxygen consumption (EPOC) was evaluated after the three swimming speeds....... There was no evidence of EPOC after swimming 1.4 and 1.9 bl s-1 indicating that the gait transition from pectoral oscillation to axial undulation is not a threshold for anaerobic metabolism. In contrast, swimming at 2.3 bl s-1 resulted in EPOC being 51.7 mg O2 kg-1 suggesting that anaerobic metabolism added about 34......% to the exercise MO2. E. lateralis switched to an unsteady burst and flap gait at 2.3 bl s-1. Burst activity correlated linearly and positively with the magnitude of the resulting EPOC. Collectively, these data suggest that steady axial propulsion does not lead to EPOC whereas transition to burst assisted swimming...

  19. Teaching children the freestyle swimming stroke

    OpenAIRE

    Vajglová, Kateřina

    2017-01-01

    The aim of this study is to compare two groups of children both practicing the freestyle swimming stroke. One group attended the Juklík swimming club from an early age and the second group attended swimming lessons provided through primary school. An integral part of this study was to compare the teaching methods, preparations and objectives used in the two models. Results of these observations are displayed in the form of graphs based on the results of an identical swimming test. KEYWORDS Sw...

  20. Efficient Management Design for Swimming Exercise Treatment

    National Research Council Canada - National Science Library

    Kim, Kyunghun; Kyung, Taewon; Kim, Wonhyun; Shin, Chungsick; Song, Youngjae; Lee, Moo Yeol; Lee, Hyunwoo; Cho, Yongchan

    2009-01-01

    Exercise-mediated physical treatment has attracted much recent interest. In particular, swimming is a representative exercise treatment method recommended for patients experiencing muscular and cardiovascular diseases...

  1. Metabolic responses at various intensities relative to critical swimming velocity.

    Science.gov (United States)

    Toubekis, Argyris G; Tokmakidis, Savvas P

    2013-06-01

    To avoid any improper training load, the speed of endurance training needs to be regularly adjusted. Both the lactate threshold (LT) velocity and the velocity corresponding to the maximum lactate steady state (MLSS) are valid and reliable indices of swimming aerobic endurance and commonly used for evaluation and training pace adjustment. Alternatively, critical velocity (CV), defined as the velocity that can be maintained without exhaustion and assessed from swimming performance of various distances, is a valid, reliable, and practical index of swimming endurance, although the selection of the proper distances is a determinant factor. Critical velocity may be 3-6 and 8-11% faster compared with MLSS and LT, respectively. Interval swimming at CV will probably show steady-lactate concentration when the CV has been calculated by distances of 3- to 15-minute duration, and this is more evident in adult swimmers, whereas increasing or decreasing lactate concentration may appear in young and children swimmers. Therefore, appropriate corrections should be made to use CV for training pace adjustment. Findings in young and national level adult swimmers suggest that repetitions of distances of 100-400 m, and velocities corresponding to a CV range of 98-102% may be used for pacing aerobic training, training at the MLSS, and possibly training for improvement of VO2max. Calculation of CV from distances of 200-400, 50-100-200-400, or 100-800 m is an easy and practical method to assess aerobic endurance. This review intends to study the physiological responses and the feasibility of using CV for aerobic endurance evaluation and training pace adjustment, to help coaches to prescribe training sets for different age-group swimmers.

  2. A Comparative Analysis of Swimming Styles in Competitive Swimming

    Science.gov (United States)

    von Loebbecke, Alfred; Mittal, Rajat; Gupta, Varun; Mark, Russell

    2007-11-01

    High-fidelity numerical simulations are being used to conduct a critical evaluation of swimming strokes in competitive swimming. We combine computational fluid dynamics (CFD), laser body scans, animation software, and video footage to develop accurate models of Olympic level swimmers and use these to examine contrasting styles of the dolphin kick as well as the arm strokes in back and front crawl stroke. In the dolphin kick, the focus is on examining the effects of Strouhal number, kick amplitude, frequency, and technique on thrust production. In the back stroke, we examine the performance of the so called ``flat stroke'' versus the ``deep catch,'' The most important aspect that separates the two major types of back stroke is the alignment or angle of attack of the palm during the stroke. In one style of front crawl arm stroke, there is greater elbow joint flexion, shoulder abduction and sculling whereas the other style consists of a straight arm pull dominated by simple shoulder flexion. Underlying the use of these two styles is the larger and more fundamental issue of the role of lift versus drag in thrust production and we use the current simulations to examine this issue in detail.

  3. Knee pain in competitive swimming.

    Science.gov (United States)

    Rodeo, S A

    1999-04-01

    The high volume of training in competitive swimming results in cumulative overload injuries. Knee pain ranks second to shoulder pain as a common complaint in competitive swimmers. Most knee pain occurs on the medial side of the knee and, most commonly, in breaststroke swimmers; however, knee pain may accompany all strokes. This article reviews the incidence of knee pain, the biomechanic and anatomic factors predisposing to injury, specific injury patterns, injury diagnosis, and the treatment and prevention of injury to the knee in swimmers.

  4. Analysis of Relationships between the Level of Errors in Leg and Monofin Movement and Stroke Parameters in Monofin Swimming.

    Science.gov (United States)

    Rejman, Marek

    2013-01-01

    The aim of this study was to analyze the error structure in propulsive movements with regard to its influence on monofin swimming speed. The random cycles performed by six swimmers were filmed during a progressive test (900m). An objective method to estimate errors committed in the area of angular displacement of the feet and monofin segments was employed. The parameters were compared with a previously described model. Mutual dependences between the level of errors, stroke frequency, stroke length and amplitude in relation to swimming velocity were analyzed. The results showed that proper foot movements and the avoidance of errors, arising at the distal part of the fin, ensure the progression of swimming speed. The individual stroke parameters distribution which consists of optimally increasing stroke frequency to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors. Identification of key elements in the stroke structure based on the analysis of errors committed should aid in improving monofin swimming technique. Key pointsThe monofin swimming technique was evaluated through the prism of objectively defined errors committed by the swimmers.The dependences between the level of errors, stroke rate, stroke length and amplitude in relation to swimming velocity were analyzed.Optimally increasing stroke rate to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors.Propriety foot movement and the avoidance of errors arising at the distal part of fin, provide for the progression of swimming speed.The key elements improving monofin swimming technique, based on the analysis of errors committed, were designated.

  5. Analysis of Relationships between the Level of Errors in Leg and Monofin Movement and Stroke Parameters in Monofin Swimming

    Science.gov (United States)

    Rejman, Marek

    2013-01-01

    The aim of this study was to analyze the error structure in propulsive movements with regard to its influence on monofin swimming speed. The random cycles performed by six swimmers were filmed during a progressive test (900m). An objective method to estimate errors committed in the area of angular displacement of the feet and monofin segments was employed. The parameters were compared with a previously described model. Mutual dependences between the level of errors, stroke frequency, stroke length and amplitude in relation to swimming velocity were analyzed. The results showed that proper foot movements and the avoidance of errors, arising at the distal part of the fin, ensure the progression of swimming speed. The individual stroke parameters distribution which consists of optimally increasing stroke frequency to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors. Identification of key elements in the stroke structure based on the analysis of errors committed should aid in improving monofin swimming technique. Key points The monofin swimming technique was evaluated through the prism of objectively defined errors committed by the swimmers. The dependences between the level of errors, stroke rate, stroke length and amplitude in relation to swimming velocity were analyzed. Optimally increasing stroke rate to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors. Propriety foot movement and the avoidance of errors arising at the distal part of fin, provide for the progression of swimming speed. The key elements improving monofin swimming technique, based on the analysis of errors committed, were designated. PMID:24149742

  6. Propulsive force in front crawl swimming

    NARCIS (Netherlands)

    Berger, M.A.M.; de Groot, G.; Hollander, A.P.

    1999-01-01

    To evaluate the propulsive forces in front crawl arm swimming, derived from a three-dimensional kinematic analysis, these values were compared with mean drag forces. The propulsive forces during front crawl swimming using the arms only were calculated using three-dimensional kinematic analysis

  7. Swimming and muscle structure in fish

    NARCIS (Netherlands)

    Spierts, I.L.Y.

    1999-01-01

    In this series of studies the relations between swimming behaviour of fish in general and extreme swimming responses in particular (called fast starts or escape responses) and the structure and ontogeny of the muscle system was investigated. Special attention was paid to relate functional

  8. Basic Land Drills for Swimming Stroke Acquisition

    Science.gov (United States)

    Zhang, Peng

    2014-01-01

    Teaching swimming strokes can be a challenging task in physical education. The purpose of the article is to introduce 12 on land drills that can be utilized to facilitate the learning of swimming strokes, including elementary back stroke, sidestroke, front crawl, back stroke, breaststroke, and butterfly. Each drill consists of four components…

  9. Optimal Swimming at low Reynolds numbers

    OpenAIRE

    Avron, J. E.; Gat, O.; Kenneth, O.

    2004-01-01

    Efficient swimming at low Reynolds numbers is a major concern of microbots. To compare the efficiencies of different swimmers we introduce the notion of ``swimming drag coefficient'' which allows for the ranking of swimmers. We find the optimal swimmer within a certain class of two dimensional swimmers using conformal mappings techniques.

  10. Swimming Dynamics and Propulsive Efficiency of Squids throughout Ontogeny

    National Research Council Canada - National Science Library

    Ian K. Bartol; Paul S. Krueger; Joseph T. Thompson; William J. Stewart

    2008-01-01

    .... These morphological changes and varying flow conditions affect swimming performance in squids. To determine how swimming dynamics and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV...

  11. The Backstroke Swimming Start: State of the Art

    National Research Council Canada - National Science Library

    Karla de Jesus; Kelly de Jesus; Ricardo J. Fernandes; João Paulo Vilas-Boas; Ross Sanders

    2014-01-01

    .... These included two swimming specific publications, eight peer-reviewed journal articles, three from the Biomechanics and Medicine in Swimming Congress series, eight from the International Society...

  12. Peculiarities of a backstroke swimming technique acceleration in elementary education

    National Research Council Canada - National Science Library

    Liliya Sheyko

    2016-01-01

    Purpose: to research the possibility of intensification and improvement of the efficiency of swimming training for adults by use of accelerated learning backstroke swimming techniques. Material & Methods...

  13. Swimming level classification of young school age children and their success in a long distance swimming test

    OpenAIRE

    Nováková, Martina

    2010-01-01

    Title: Swimming level classification of young school age children and their success in a long distance swimming test Work objectives: The outcome of our work is comparison and evaluation of the initial and final swimming lenght in a test of long distance swimming. This test is taken during one swimming course. Methodology: Data which were obtained by testing a certain group of people and were statistically processed, showed the swimming level and performance of the young school age children. ...

  14. The swim force as a body force

    Science.gov (United States)

    Yan, Wen; Brady, John

    2015-11-01

    Net (as opposed to random) motion of active matter results from an average swim (or propulsive) force. It is shown that the average swim force acts like a body force - an internal body force [Yan and Brady, Soft Matter, DOI:10.1039/C5SM01318F]. As a result, the particle-pressure exerted on a container wall is the sum of the swim pressure [Takatori et al., Phys. Rev. Lett., 2014, 113, 028103] and the `weight' of the active particles. A continuum mechanical description is possible when variations occur on scales larger than the run length of the active particles and gives a Boltzmann-like distribution from a balance of the swim force and the swim pressure. Active particles may also display `action at a distance' and accumulate adjacent to (or be depleted from) a boundary without any external forces. In the momentum balance for the suspension - the mixture of active particles plus fluid - only external body forces appear.

  15. Prey capture by freely swimming flagellates

    Science.gov (United States)

    Andersen, Anders; Dolger, Julia; Nielsen, Lasse Tor; Kiorboe, Thomas

    2017-11-01

    Flagellates are unicellular microswimmers that propel themselves using one or several beating flagella. Here, we explore the dependence of swimming kinematics and prey clearance rate on flagellar arrangement and determine optimal flagellar arrangements and essential trade-offs. To describe near-cell flows around freely swimming flagellates we consider a model in which the cell is represented by a no-slip sphere and each flagellum by a point force. For uniflagellates pulled by a single flagellum the model suggests that a long flagellum favors fast swimming, whereas high clearance rate is favored by a very short flagellum. For biflagellates with both a longitudinal and a transversal flagellum we explore the helical swimming kinematics and the prey capture sites. We compare our predictions with observations of swimming kinematics, prey capture, and flows around common marine flagellates. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

  16. Winter swimming improves general well-being.

    Science.gov (United States)

    Huttunen, Pirkko; Kokko, Leena; Ylijukuri, Virpi

    2004-05-01

    This study deals with the effects of regular winter swimming on the mood of the swimmers. Profile of Mood State (POMS) and OIRE questionnaires were completed before (October) and after (January) the four-month winter swimming period. In the beginning, there were no significant differences in the mood states and subjective feelings between the swimmers and the controls. The swimmers had more diseases (about 50%) diagnosed by a physician. Tension, fatigue, memory and mood negative state points in the swimmers significantly decreased with the duration of the swimming period. After four months, the swimmers felt themselves to be more energetic, active and brisk than the controls. Vigour-activity scores were significantly greater (p winter swimming had relieved pains. Improvement of general well-being is thus a benefit induced by regular winter swimming.

  17. Is swimming during pregnancy a safe exercise?

    DEFF Research Database (Denmark)

    Juhl, Mette; Kogevinas, Manolis; Andersen, Per Kragh

    2010-01-01

    BACKGROUND: Exercise in pregnancy is recommended in many countries, and swimming is considered by many to be an ideal activity for pregnant women. Disinfection by-products in swimming pool water may, however, be associated with adverse effects on various reproductive outcomes. We examined...... the association between swimming in pregnancy and preterm and postterm birth, fetal growth measures, small-for-gestational-age, and congenital malformations. METHODS: We used self-reported exercise data (swimming, bicycling, or no exercise) that were prospectively collected twice during pregnancy for 74......,486 singleton pregnancies. Recruitment to The Danish National Birth Cohort took place 1996-2002. Using Cox, linear and logistic regression analyses, depending on the outcome, we compared swimmers with physically inactive pregnant women; to separate a possible swimming effect from an effect of exercise...

  18. Shaping Physiological Indices, Swimming Technique, and Their Influence on 200m Breaststroke Race in Young Swimmers

    Directory of Open Access Journals (Sweden)

    Marek Strzala

    2015-03-01

    Full Text Available The aim of this study was to investigate somatic properties and physiological capacity, and analyze kinematic parameters in the 200 m breaststroke swimming race. Twenty-seven male swimmers participated in the study. They were 15.7±1.98 years old. Their average height was 1.80 ± 0.02 m and lean body mass (LBM was 62.45 ± 8.29 kg. Physiological exercise capacity was measured in two separate 90 sec. all-out tests, one for the arms and second for legs. During the tests total work of arm cranking (TWAR and cycling (TWLG as well as peak of VO2 for arm (VO2peakAR and leg (VO2peakLG were measured. The underwater swimmers body movements were recorded during the all-out swimming 200m breaststroke speed test using an underwater camera installed on a portable trolley. The swimming kinematic parameters and propulsive or non-propulsive movement phases of the arms and legs as well as average speed (V200, surface speed (V200surface and swimming speed in turn zones (V200turns were extracted. V200surface was significantly related to the percentage of leg propulsion and was shown to have large effect on VO2peakLG in the Cohen analysis. V200turns depended significantly on the indicators of physiological performance and body structure: TWAR, VO2peak LG and LBM, LBM, which in turn strongly determined the measured results of TWAR, TWLG, VO2peakAR and VO2peakLG. The V200turns and V200surface were strongly associated with V200, 0.92, p < 0.001 and 0.91, p < 0.001 respectively. In each lap of the 200m swimming there was an increased percentage of propulsion of limb movement observed simultaneously with a reduction in the gliding phase in the breaststroke cycles.

  19. Noiseless propulsion for swimming robotic structures using polyelectrolyte ion-exchange membrane

    Science.gov (United States)

    Mojarrad, Mehran; Shahinpoor, Mohsen

    1996-02-01

    In this paper a NafionTM polyelectrolyte ion-exchange membrane (IEM) was used as a propulsion fin for robotic swimming structures such as a boat or fish-like object swimming in water or aqueous medium. The Nafion membrane was chemically plated with platinum. The resulting membrane was cut in a strip to resemble a fish-like caudal fin for propulsion. A small function generator circuit was designed and built to produce approximately plus or minus 2.0 V amplitude square wave at varying frequency up to 50 Hz. The circuit board was mounted on a buoyant styrofoam shaped like a boat or a tadpole. The fin was attached to the rear of the boat. By setting the signal frequency to the desired value and thereby setting the frequency of bending oscillation of the membrane, a proportional forward propulsion speed could be obtained. The speed was then measured using a high speed camera. Several theoretical hydrodynamic models were then presented to characterize speed-frequency of the forward motion using available theories on biological fish motion. The results were compared to experimental data which showed close agreement. It turned out that the forward speed of the object was directly proportional to the product of frequency and amplitude of the fin oscillation as in biological fishes. This relation was further simplified by keeping the voltage constant and therefore amplitude of the oscillation. The proportionality constant could be measured for a known geometry of the fin-boat assembly and reactivity of the Nafion membrane used. The system as a whole presented an autonomous robotic swimming structure with frequency modulated propulsion to investigate application of polyelectrolyte hydrogel membranes and their effect on hydrodynamic behavior of an undulating swimming object. As in fishes the thrust force of the robot was generated by evolution of vortices on the sides of the undulating fin. For a constant forward speed, this thrust is equal to the drag force due to geometry

  20. Three-Minute All-Out Test in Swimming.

    Science.gov (United States)

    Tsai, Ming-Chang; Thomas, Scott G

    2017-01-01

    To validate the 3-minute all-out exercise test (3MT) protocol against the traditional critical-speed (CS) model (CSM) in front-crawl swimming. Ten healthy swimmers or triathletes (mean ± SD age 35.2 ± 10.5 y, height 176.5 ± 5.4 cm, body mass 69.6 ± 8.2 kg) completed 5 tests (3MT, 100m, 200m, 400m, 800m) over 2 wk on separate days. Traditional CS and anaerobic distance capacity (D') were determined for each of the 3 traditional CSMs (linear distance-time, LIN; linear speed/time, INV; nonlinear time-speed, NLIN) from the 4 set-distance time trials. For the 3MT, CS was determined as the mean speed during the final 30 s of the test and D' was estimated as the power-time integral above the CS. Our results indicated no significant difference between the CS estimates determined from the traditional CSM and 3MT except for the INV model (P = .0311). Correlations between traditional CSMs and 3MT were high (r = .95, P .1). In addition, Bland-Altman plots between the traditional CSMs and 3MT CS estimates showed scattered points above and below the zero line, suggesting there is no consistent bias of one approach versus the other. The 3MT is a valid protocol for swimming to estimate CS. The demonstrated concurrent validity of the 3MT may allow more widespread use of CSMs to evaluate participants and responses to training.

  1. Divergence in physiological factors affecting swimming performance between anadromous and resident populations of brook charr Salvelinus fontinalis.

    Science.gov (United States)

    Crespel, A; Dupont-Prinet, A; Bernatchez, L; Claireaux, G; Tremblay, R; Audet, C

    2017-05-01

    In this study, an anadromous strain (L) and a freshwater-resident (R) strain of brook charr Salvelinus fontinalis as well as their reciprocal hybrids, were reared in a common environment and submitted to swimming tests combined with salinity challenges. The critical swimming speeds (Ucrit ) of the different crosses were measured in both fresh (FW) and salt water (SW) and the variations in several physiological traits (osmotic, energetic and metabolic capacities) that are predicted to influence swimming performance were documented. Anadromous and resident fish reached the same Ucrit in both FW and SW, with Ucrit being 14% lower in SW compared with FW. The strains, however, seemed to use different underlying strategies: the anadromous strain relied on its streamlined body shape and higher osmoregulatory capacity, while the resident strain had greater citrate synthase (FW) and lactate dehydrogenase (FW, SW) capacity and either greater initial stores or more efficient use of liver (FW, SW) and muscle (FW) glycogen during exercise. Compared with R♀ L♂ hybrids, L♀ R♂ hybrids had a 20% lower swimming speed, which was associated with a 24% smaller cardio-somatic index and higher physiological costs. Thus swimming performance depends on cross direction (i.e. which parental line was used as dam or sire). The study thus suggests that divergent physiological factors between anadromous and resident S. fontinalis may result in similar swimming capacities that are adapted to their respective lifestyles. © 2017 The Fisheries Society of the British Isles.

  2. An immersed boundary method for two-phase fluids and gels and the swimming of Caenorhabditis elegans through viscoelastic fluids

    Science.gov (United States)

    Lee, Pilhwa; Wolgemuth, Charles

    2016-11-01

    While swimming in Newtonian fluids has been examined extensively, only recently have investigations into microorganism swimming through non-Newtonian fluids and gels been explored. The equations that govern these more complex media are often nonlinear and require computational algorithms to study moderate to large amplitude motions of the swimmer. Here we develop an immersed boundary method for handling fluid-structure interactions in a general two-phase medium, where one phase is a Newtonian fluid and the other phase is viscoelastic. We use this algorithm to investigate the swimming of an undulating, filamentary swimmer in 2D. A novel aspect of our method is that it allows one to specify how forces produced by the swimmer are distributed between the two phases of the fluid. The algorithm is validated by comparison to theoretical predictions for small amplitude swimming in gels and viscoelastic fluids. We show how the swimming velocity depends on material parameters of the fluid and the interaction between the fluid and swimmer. In addition, we simulate the swimming of Caenorhabditis elegans in viscoelastic fluids and find good agreement between the swimming speeds and fluid flows in our simulations and previous experimental measurements. NIH R01 GM072004, NIH P50GM094503.

  3. The interaction between water currents and salmon swimming behaviour in sea cages.

    Directory of Open Access Journals (Sweden)

    David Johansson

    Full Text Available Positioning of sea cages at sites with high water current velocities expose the fish to a largely unknown environmental challenge. In this study we observed the swimming behaviour of Atlantic salmon (Salmo salar L. at a commercial farm with tidal currents altering between low, moderate and high velocities. At high current velocities the salmon switched from the traditional circular polarized group structure, seen at low and moderate current velocities, to a group structure where all fish kept stations at fixed positions swimming against the current. This type of group behaviour has not been described in sea cages previously. The structural changes could be explained by a preferred swimming speed of salmon spatially restricted in a cage in combination with a behavioural plasticity of the fish.

  4. Swimming eel-like robot

    OpenAIRE

    Vanderwegen, Gilles; Barbason, Martin

    2017-01-01

    Le mémoire "Swimming eel-like robot" consiste en la réalisation d'un robot à nage anguilliforme afin d'obtenir des résultats expérimentaux permettant de critiquer des simulations réalisées dans le cadre d'un doctorat à l'Université Catholique de Louvain. Les étapes importantes du projet sont la conception, le dimensionnement, le contrôle du robot et l'analyse cinématique et dynamique de sa nage. La phase de conception est basée sur deux critères restrictifs. Le premier est le respect du "desi...

  5. SWIM EVERYDAY TO KEEP DEMENTIA AWAY

    Directory of Open Access Journals (Sweden)

    Nirmal Singh

    2005-03-01

    Full Text Available A sound mind resides in a sound body. Many individuals with an active lifestyle show sharp mental skills at an advanced age. Regular exercise has been shown to exert numerous beneficial effects on brawn as well as brain. The present study was undertaken to evaluate the influence of swimming on memory of rodents. A specially designed hexagonal water maze was used for the swimming exposures of animals. The learning and memory parameters were measured using exteroceptive behavioral models such as Elevated plus-maze, Hebb-Williams maze and Passive avoidance apparatus. The rodents (rats and mice were divided into twelve groups. The swimming exposure to the rodents was for 10- minute period during each session and there were two swimming exposures on each day. Rats and mice were subjected to swimming for -15 and -30 consecutive days. Control group animals were not subjected to swimming during above period. The learning index and memory score of all the animals was recorded on 1st, 2nd, 15th, 16th, 30th and 31st day employing above exteroceptive models. It was observed that rodents that underwent swimming regularly for 30- days showed sharp memories, when tested on above behavioral models whereas, control group animals showed decline in memory scores. Those animals, which underwent swimming for 15- days only showed good memory on 16th day, which however, declined after 30-days. These results emphasize the role of regular physical exercise particularly swimming in the maintenance and promotion of brain functions. The underlying physiological mechanism for improvement of memory appears to be the result of enhanced neurogenesis.

  6. Endosulfan induces changes in spontaneous swimming activity and acetylcholinesterase activity of Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, M.L. [Facultad de Ciencias Exactas, Fisicas y Naturales, Catedra Diversidad Animal II, Universidad Nacional de Cordoba, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Durando, P.E. [Facultad de Ciencias Exactas, Fisicas y Naturales, Departamento de Biologia, Catedra de Fisiologia Animal, Universidad Nacional de San Juan, Complejo ' Islas Malvinas' , Av. Jose I. de la Roza y Meglioli, Rivadavia, San Juan (Argentina); Nores, M.L. [Facultad de Ciencias Medicas, Universidad Nacional de Cordoba-CONICET, Ciudad Universitaria, Cordoba (Argentina); Diaz, M.P. [Facultad de Ciencias Medicas, Catedra de Estadistica y Bioestadistica, Escuela de Nutricion, Universidad Nacional de Cordoba, Pabellon Chile, Ciudad Universitaria, 5000 Cordoba (Argentina); Bistoni, M.A., E-mail: mbistoni@com.uncor.ed [Facultad de Ciencias Exactas, Fisicas y Naturales, Catedra Diversidad Animal II, Universidad Nacional de Cordoba, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Wunderlin, D.A. [Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica-CIBICI, Universidad Nacional de Cordoba-CONICET, Haya de la Torre esq. Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2009-05-15

    We assessed changes in spontaneous swimming activity and acetylcholinesterase (AchE) activity of Jenynsia multidentata exposed to Endosulfan (EDS). Females of J. multidentata were exposed to 0.072 and 1.4 mug L{sup -1} EDS. Average speed and movement percentage were recorded during 48 h. We also exposed females to EDS at five concentrations between 0.072 and 1.4 mug L{sup -1} during 24 h, and measured the AchE activity in brain and muscle. At 0.072 mug L{sup -1} EDS swimming motility decreased relative to the control group after 45 h, while at 1.4 mug L{sup -1} EDS swimming motility decreased after 24 h. AchE activity significantly decreased in muscle when J. multidentata were exposed to EDS above 0.072 mug L{sup -1}, while no significant changes were observed in brain. Thus, changes in swimming activity and AchE activity in muscle are good biomarkers of exposure to EDS in J. multidentata. - This work reports changes observed in spontaneous swimming activity and AchE activity of Jenynsia multidentata exposed to sublethal concentrations of Endosulfan.

  7. Swimming kinematic and flotation analysis of conscious and sedated dogs using 3 canine flotation devices.

    Science.gov (United States)

    Corum, China Prentice; Wichtowski, Maja; Hetts, Suzanne; Estep, Dan; Bertone, Joseph J

    2014-12-01

    Canine flotation devices (CFDs) are very popular; however, their efficacy is still under debate. There is no oversight to standardize device testing, certification, or qualification for use. We set out to assess the biomechanical and behavioral effects of 3 CFDs on swim and flotation characteristics of dogs. High-speed video recordings were used to measure behavior, range of motion (ROM), maximum flexion angle, and cycles of motion per minute while swimming and roll, yaw, and fear or panic scoring while floating. Predictably, swimming with no CFD yielded the largest ROM and flexion angles. CFDINF was associated with the least ROM. During flotation, CFDAB and CFDRW caused significant rolling and fear, whereas CFDINF was the most stable. CFDAB was associated with cranial downpitch in 2 dogs. Interpretation of the kinematics for CFDAB and CFDRW suggests that decreased stability in the water leads to a greater forced ROM when the position of the dog was conducive to swimming. When positioning forced the dog into a downward pitch, ROM was decreased because of the increased effort for the dogs to keep their head above water. CFDINF was most stable overall owing to a decreased swim effort, with most dogs showing the lowest fear scores and absolute relaxation. CFDAB and CFDRW caused the dogs significant rolling, fear, and distress, with obvious fighting of sedation. We hope to disseminate these results to dog owners in the hopes of providing a valid assessment of these devices. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis)

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Jessie L.; McGeer, James C., E-mail: jmcgeer@wlu.ca

    2016-04-15

    Highlights: • Exposure to 18 nM waterborne Cd induced plasma Ca loss that recovered by day 30 for lake whitefish but not brown trout. • Ucrit measured after an initial swim to 85% of Ucrit and a 30 min rest period was reduced in 18 nM Cd exposed fish compared to controls. • Swimming to 85% of Ucrit resulted in decreased muscle glycogen and increased lactate that was not recovered in the 30 min recovery period. • Second swim impairment is not related to metabolic processes in white muscle. - Abstract: This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18 nM) in moderately hard water (120 mg L{sup −1} CaCO{sub 3}) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (U{sub crit}) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the U{sub crit} of control fish, a 30 min recovery period and finally a second swim challenge to determine U{sub crit}. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim U{sub crit} and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure

  9. Mechanical models of sandfish locomotion reveal principles of high performance subsurface sand-swimming

    Science.gov (United States)

    Maladen, Ryan D.; Ding, Yang; Umbanhowar, Paul B.; Kamor, Adam; Goldman, Daniel I.

    2011-01-01

    We integrate biological experiment, empirical theory, numerical simulation and a physical model to reveal principles of undulatory locomotion in granular media. High-speed X-ray imaging of the sandfish lizard, Scincus scincus, in 3 mm glass particles shows that it swims within the medium without using its limbs by propagating a single-period travelling sinusoidal wave down its body, resulting in a wave efficiency, η, the ratio of its average forward speed to the wave speed, of approximately 0.5. A resistive force theory (RFT) that balances granular thrust and drag forces along the body predicts η close to the observed value. We test this prediction against two other more detailed modelling approaches: a numerical model of the sandfish coupled to a discrete particle simulation of the granular medium, and an undulatory robot that swims within granular media. Using these models and analytical solutions of the RFT, we vary the ratio of undulation amplitude to wavelength (A/λ) and demonstrate an optimal condition for sand-swimming, which for a given A results from the competition between η and λ. The RFT, in agreement with the simulated and physical models, predicts that for a single-period sinusoidal wave, maximal speed occurs for A/λ ≈ 0.2, the same kinematics used by the sandfish. PMID:21378020

  10. The effect of water temperature on routine swimming behaviour of new born guppies (Poecilia reticulata

    Directory of Open Access Journals (Sweden)

    Maud Kent

    2015-03-01

    Full Text Available Guppies have successfully established populations in places with thermal regimes very different from the Tropical conditions in their native range. This indicates a remarkable capacity for thermal adaptation. Given their vulnerability to predation as juveniles, acute changes in temperature, which can alter predator-prey relationships, can impact juvenile survival and have amplified consequences at the population level. To understand how temperature may impact juvenile survival and gain insight into their success as an invasive species, we researched the effect of acute temperature changes on the routine swimming behaviour of juvenile guppies. Using a novel 3-dimensional tracking technique, we calculated 4 routine swimming parameters, speed, depth, and variation in speed or depth, at 6 different test temperatures (17, 20, 23, 26, 29, or 32°C. These temperatures cover their natural thermal range and also extended past it in order to include upper and lower thermal limits. Using model selection, we found that body length and temperature had a significant positive relationship with speed. Variation in speed decreased with rising temperatures and fish swam slightly closer to the bottom at higher temperatures. All juveniles increased variation in depth at higher temperatures, though larger individuals maintained slightly more consistent depths. Our results indicate that guppies have a large thermal range and show substantial plasticity in routine swimming behaviours, which may account for their success as an invasive species.

  11. The effect of water temperature on routine swimming behaviour of new born guppies (Poecilia reticulata).

    Science.gov (United States)

    Kent, Maud; Ojanguren, Alfredo F

    2015-03-06

    Guppies have successfully established populations in places with thermal regimes very different from the Tropical conditions in their native range. This indicates a remarkable capacity for thermal adaptation. Given their vulnerability to predation as juveniles, acute changes in temperature, which can alter predator-prey relationships, can impact juvenile survival and have amplified consequences at the population level. To understand how temperature may impact juvenile survival and gain insight into their success as an invasive species, we researched the effect of acute temperature changes on the routine swimming behaviour of juvenile guppies. Using a novel 3-dimensional tracking technique, we calculated 4 routine swimming parameters, speed, depth, and variation in speed or depth, at 6 different test temperatures (17, 20, 23, 26, 29, or 32°C). These temperatures cover their natural thermal range and also extended past it in order to include upper and lower thermal limits. Using model selection, we found that body length and temperature had a significant positive relationship with speed. Variation in speed decreased with rising temperatures and fish swam slightly closer to the bottom at higher temperatures. All juveniles increased variation in depth at higher temperatures, though larger individuals maintained slightly more consistent depths. Our results indicate that guppies have a large thermal range and show substantial plasticity in routine swimming behaviours, which may account for their success as an invasive species. © 2015. Published by The Company of Biologists Ltd.

  12. Biomechanics, energetics and coordination during extreme swimming intensity: effect of performance level.

    Science.gov (United States)

    Ribeiro, João; Figueiredo, Pedro; Morais, Sara; Alves, Francisco; Toussaint, Huub; Vilas-Boas, João Paulo; Fernandes, Ricardo Jorge

    2017-08-01

    The present study aimed to examine how high- and low-speed swimmers organise biomechanical, energetic and coordinative factors throughout extreme intensity swim. Sixteen swimmers (eight high- and eight low-speed) performed, in free condition, 100-m front crawl at maximal intensity and 25, 50 and 75-m bouts (at same pace as the previous 100-m), and 100-m maximal front crawl on the measuring active drag system (MAD-system). A 3D dual-media optoelectronic system was used to assess speed, stroke frequency, stroke length, propelling efficiency and index of coordination (IdC), with power assessed by MAD-system and energy cost by quantifying oxygen consumption plus blood lactate. Both groups presented a similar profile in speed, power output, stroke frequency, stroke length, propelling efficiency and energy cost along the effort, while a distinct coordination profile was observed (F (3, 42)  = 3.59, P = 0.04). Speed, power, stroke frequency and propelling efficiency (not significant, only a tendency) were higher in high-speed swimmers, while stroke length and energy cost were similar between groups. Performing at extreme intensity led better level swimmers to achieve superior speed due to higher power and propelling efficiency, with consequent ability to swim at higher stroke frequencies. This imposes specific constraints, resulting in a distinct IdC magnitude and profile between groups.

  13. Hydrodynamic study of freely swimming shark fish propulsion for marine vehicles using 2D particle image velocimetry.

    Science.gov (United States)

    Babu, Mannam Naga Praveen; Mallikarjuna, J M; Krishnankutty, P

    Two-dimensional velocity fields around a freely swimming freshwater black shark fish in longitudinal (XZ) plane and transverse (YZ) plane are measured using digital particle image velocimetry (DPIV). By transferring momentum to the fluid, fishes generate thrust. Thrust is generated not only by its caudal fin, but also using pectoral and anal fins, the contribution of which depends on the fish's morphology and swimming movements. These fins also act as roll and pitch stabilizers for the swimming fish. In this paper, studies are performed on the flow induced by fins of freely swimming undulatory carangiform swimming fish (freshwater black shark, L = 26 cm) by an experimental hydrodynamic approach based on quantitative flow visualization technique. We used 2D PIV to visualize water flow pattern in the wake of the caudal, pectoral and anal fins of swimming fish at a speed of 0.5-1.5 times of body length per second. The kinematic analysis and pressure distribution of carangiform fish are presented here. The fish body and fin undulations create circular flow patterns (vortices) that travel along with the body waves and change the flow around its tail to increase the swimming efficiency. The wake of different fins of the swimming fish consists of two counter-rotating vortices about the mean path of fish motion. These wakes resemble like reverse von Karman vortex street which is nothing but a thrust-producing wake. The velocity vectors around a C-start (a straight swimming fish bends into C-shape) maneuvering fish are also discussed in this paper. Studying flows around flapping fins will contribute to design of bioinspired propulsors for marine vehicles.

  14. Measurement of hydrodynamic force generation by swimming dolphins using bubble DPIV.

    Science.gov (United States)

    Fish, Frank E; Legac, Paul; Williams, Terrie M; Wei, Timothy

    2014-01-15

    Attempts to measure the propulsive forces produced by swimming dolphins have been limited. Previous uses of computational hydrodynamic models and gliding experiments have provided estimates of thrust production by dolphins, but these were indirect tests that relied on various assumptions. The thrust produced by two actively swimming bottlenose dolphins (Tursiops truncatus) was directly measured using digital particle image velocimetry (DPIV). For dolphins swimming in a large outdoor pool, the DPIV method used illuminated microbubbles that were generated in a narrow sheet from a finely porous hose and a compressed air source. The movement of the bubbles was tracked with a high-speed video camera. Dolphins swam at speeds of 0.7 to 3.4 m s(-1) within the bubble sheet oriented along the midsagittal plane of the animal. The wake of the dolphin was visualized as the microbubbles were displaced because of the action of the propulsive flukes and jet flow. The oscillations of the dolphin flukes were shown to generate strong vortices in the wake. Thrust production was measured from the vortex strength through the Kutta-Joukowski theorem of aerodynamics. The dolphins generated up to 700 N during small amplitude swimming and up to 1468 N during large amplitude starts. The results of this study demonstrated that bubble DPIV can be used effectively to measure the thrust produced by large-bodied dolphins.

  15. Oxygen Consumption and Swimming Performance in Hypoxia-Acclimated Rainbow Trout Salmo Gairdneri

    DEFF Research Database (Denmark)

    BUSHNELL, PG; STEFFENSEN, JF; JOHANSEN, K

    1984-01-01

    1. Swimming performance and oxygen consumption of normoxic (control) and hypoxia-acclimated (P002=40 mmHg) rainbow trout, Salmo gairdneri Richardson, were monitored at >145, 60 and 40mmHg. 2. Maximum swimming velocity at 40mmHg was reduced from >54.8cm s-1 to 41.4cm s1 in controls and to 40.6 cm s......Hg did not significantly change oxygen consumption in control animals, although no fish (control or hypoxia acclimated) completed swimming trials at 54.8cm s-1 in 40mmHg. 5. Oxygen consumption of hypoxia-acclimated fish at 5.5cm s-1 and 40 mmHg was significantly higher than oxygen uptake in normoxia...... at the same speed. This relative increase was not maintained, however, as oxygen consumption at higher swimming speeds was similar to that in normoxia. 6. Blood studies showed that hypoxia-acclimated fish had lower ATP concentrations and P50 values. While these factors may increase the blood oxygen loading...

  16. Ingestion of swimming pool water by recreational

    Data.gov (United States)

    U.S. Environmental Protection Agency — Swimming pool water ingestion data. This dataset is associated with the following publication: Dufour, A., L. Wymer, M. Magnuson, T. Behymer, and R. Cantu. Ingestion...

  17. Optimal Strouhal number for swimming animals

    CERN Document Server

    Eloy, Christophe

    2011-01-01

    To evaluate the swimming performances of aquatic animals, an important dimensionless quantity is the Strouhal number, St = fA/U, with f the tail-beat frequency, A the peak-to-peak tail amplitude, and U the swimming velocity. Experiments with flapping foils have exhibited maximum propulsive efficiency in the interval 0.25 < St < 0.35 and it has been argued that animals likely evolved to swim in the same narrow interval. Using Lighthill's elongated-body theory to address undulatory propulsion, it is demonstrated here that the optimal Strouhal number increases from 0.15 to 0.8 for animals spanning from the largest cetaceans to the smallest tadpoles. To assess the validity of this model, the swimming kinematics of 53 different species of aquatic animals have been compiled from the literature and it shows that their Strouhal numbers are consistently near the predicted optimum.

  18. The Fluid Dynamics of Competitive Swimming

    Science.gov (United States)

    Wei, Timothy; Mark, Russell; Hutchison, Sean

    2014-01-01

    Nowhere in sport is performance so dependent on the interaction of the athlete with the surrounding medium than in competitive swimming. As a result, understanding (at least implicitly) and controlling (explicitly) the fluid dynamics of swimming are essential to earning a spot on the medal stand. This is an extremely complex, highly multidisciplinary problem with a broad spectrum of research approaches. This review attempts to provide a historical framework for the fluid dynamics-related aspects of human swimming research, principally conducted roughly over the past five decades, with an emphasis on the past 25 years. The literature is organized below to show a continuous integration of computational and experimental technologies into the sport. Illustrations from the authors' collaborations over a 10-year period, coupling the knowledge and experience of an elite-level coach, a lead biomechanician at USA Swimming, and an experimental fluid dynamicist, are intended to bring relevance and immediacy to the review.

  19. Can phoretic particles swim in two dimensions?

    CERN Document Server

    Sondak, David; Heng, Siyu; Vinsonhaler, Rebecca; Lauga, Eric; Thiffeault, Jean-Luc

    2016-01-01

    Artificial phoretic particles swim using self-generated gradients in chemical species (self-diffusiophoresis) or charges and currents (self-electrophoresis). These particles can be used to study the physics of collective motion in active matter and might have promising applications in bioengineering. In the case of self-diffusiophoresis, the classical physical model relies on a steady solution of the diffusion equation, from which chemical gradients, phoretic flows and ultimately the swimming velocity, may be derived. Motivated by disk-shaped particles in thin films and under confinement, we examine the extension to two dimensions. Because the two-dimensional diffusion equation lacks a steady state with the correct boundary conditions, Laplace transforms must be used to study the long-time behavior of the problem and determine the swimming velocity. For fixed chemical fluxes on the particle surface, we find that the swimming velocity ultimately always decays logarithmically in time. In the case of finite Pecl...

  20. Swimming training at the lower school of primary schools

    OpenAIRE

    Vavrošová, Karolína

    2014-01-01

    This thesis is aimed on the topic of swimming training on the first grade of primary school. The theoretical part is processed according to available resources, history and importance of swimming, characterized by basic swimming training of children at school age and younger. The practical part is focused on the research sample, a swimming schools and children who participated in basic swimming training. Following sections of this thesis are analyzing the research sample, which consists of sw...

  1. Current state of swimming teaching to preschool children in Prague

    OpenAIRE

    Krischová, Jitka

    2012-01-01

    Abstraction The subject of the bachelor thesis is the current situation of swimming courses for kindergartens. The paper aims to study the quality and conditions of teaching basic swimming skills in selected swimming schools and provides approximate number and age of children participating in the courses in Prague. The theoretical part of the thesis deals with swimming and its importance in general and describes methodological and organizational specifics of swimming teaching at preschool age...

  2. Trunk muscle activity during front crawl swimming

    OpenAIRE

    Martens, Jonas; Pellegrims, Ward; Einarsson, Ingi Thor; Fernandes, Ricardo; Staes, Filip; Daly, Daniel

    2013-01-01

    Introduction Core stability training is of increasing interest to both researchers and coaches. Sufficient core stability is needed to balance forces generated by the upper and lower extremities separately (Hibbs et al., 2008). In swimming the development of wireless EMG has created new possibilities to study underwater muscle activity with little hinder. The purpose here was to analyze lower trunk muscle activation during front crawl swimming and examine how trunk muscle activity is relat...

  3. Winter swimming improves general well-being

    OpenAIRE

    Huttunen, Pirkko; Kokko, Leena; Ylijukuri, Virpi

    2004-01-01

    Objectives. This study deals with the effects of regular winter swimming on the mood of the swimmers. Methods. Profile of Mood State (POMS) and OIRE questionnaires were completed before (October) and after (January) the fourmonth winter swimming period. Results. In the beginning, there were no significant differences in the mood states and subjective feelings between the swimmers and the controls. The swimmers had more diseases (about 50%) diagnosed by a physician. Tension, fatigue, memory an...

  4. The kinematic determinants of anuran swimming performance: an inverse and forward dynamics approach.

    Science.gov (United States)

    Richards, Christopher T

    2008-10-01

    The aims of this study were to explore the hydrodynamic mechanism of Xenopus laevis swimming and to describe how hind limb kinematics shift to control swimming performance. Kinematics of the joints, feet and body were obtained from high speed video of X. laevis frogs (N=4) during swimming over a range of speeds. A blade element approach was used to estimate thrust produced by both translational and rotational components of foot velocity. Peak thrust from the feet ranged from 0.09 to 0.69 N across speeds ranging from 0.28 to 1.2 m s(-1). Among 23 swimming strokes, net thrust impulse from rotational foot motion was significantly higher than net translational thrust impulse, ranging from 6.1 to 29.3 N ms, compared with a range of -7.0 to 4.1 N ms from foot translation. Additionally, X. laevis kinematics were used as a basis for a forward dynamic anuran swimming model. Input joint kinematics were modulated to independently vary the magnitudes of foot translational and rotational velocity. Simulations predicted that maximum swimming velocity (among all of the kinematics patterns tested) requires that maximal translational and maximal rotational foot velocity act in phase. However, consistent with experimental kinematics, translational and rotational motion contributed unequally to total thrust. The simulation powered purely by foot translation reached a lower peak stroke velocity than the pure rotational case (0.38 vs 0.54 m s(-1)). In all simulations, thrust from the foot was positive for the first half of the power stroke, but negative for the second half. Pure translational foot motion caused greater negative thrust (70% of peak positive thrust) compared with pure rotational simulation (35% peak positive thrust) suggesting that translational motion is propulsive only in the early stages of joint extension. Later in the power stroke, thrust produced by foot rotation overcomes negative thrust (due to translation). Hydrodynamic analysis from X. laevis as well as forward

  5. Simulations of Unsteady Aquatic Locomotion: From Unsteadiness in Straight-Line Swimming to Fast-Starts.

    Science.gov (United States)

    Borazjani, Iman

    2015-10-01

    Unsteady aquatic locomotion is not an exception, but rather how animals often swim. It includes fast-starts (C-start or S-start), escape maneuvers, turns, acceleration/deceleration, and even during steady locomotion the swimming speed fluctuates, i.e., there is unsteadiness. Here, a review of the recent work on unsteady aquatic locomotion with emphasis on numerical simulations is presented. The review is started by an overview of different theoretical and numerical methods that have been used for unsteady swimming, and then the insights provided by these methods on (1) unsteadiness in straight-line swimming and (2) unsteady fast-starts and turns are discussed. The swimming speed's unsteady fluctuations during straight-line swimming are typically less than 3% of the average swimming speed, but recent simulations show that body shape affects fluctuations more than does body kinematics, i.e., changing the shape of the body generates larger fluctuations than does changing its kinematics. For fast-starts, recent simulations show that the best motion to maximize the distance traveled from rest are similar to the experimentally observed C-start maneuvers. Furthermore, another set of simulations, which are validated against measurements of flow in experiments with live fish, investigate the role of fins during the C-start. The simulations showed that most of the force is generated by the body of the fish (not by fins) during the first stage of the C-start when the fish bends itself into the C-shape. However, in the second stage, when it rapidly bends out of the C-shape, more than 70% of the instantaneous hydrodynamic force is produced by the tail. The effect of dorsal and anal fins was less than 5% of the instantaneous force in both stages, except for a short period of time (2 ms) just before the second stage. Therefore, the active control and the erection of the anal/dorsal fins might be related to retaining the stability of the sunfish against roll and pitch during the C

  6. Fluid Dynamics of Competitive Swimming: A Computational Study

    Science.gov (United States)

    Mittal, Rajat; Loebbeck, Alfred; Singh, Hersh; Mark, Russell; Wei, Timothy

    2004-11-01

    The dolphin kick is an important component in competitive swimming and is used extensively by swimmers immediately following the starting dive as well as after turns. In this stroke, the swimmer swims about three feet under the water surface and the stroke is executed by performing an undulating wave-like motion of the body that is quite similar to the anguilliform propulsion mode in fish. Despite the relatively simple kinematics of this stoke, considerable variability in style and performance is observed even among Olympic level swimmers. Motivated by this, a joint experimental-numerical study has been initiated to examine the fluid-dynamics of this stroke. The current presentation will describe the computational portion of this study. The computations employ a sharp interface immersed boundary method (IBM) which allows us to simulate flows with complex moving boudnaries on stationary Cartesian grids. 3D body scans of male and female Olympic swimmers have been obtained and these are used in conjuction with high speed videos to recreate a realistic dolphin kick for the IBM solver. Preliminary results from these computations will be presented.

  7. Controlling swimming and crawling in a fish robot using a central pattern generator

    OpenAIRE

    Crespi, Alessandro; Lachat, Daisy; Pasquier, Ariane; Ijspeert, Auke Jan

    2008-01-01

    Online trajectory generation for robots with multiple degrees of freedom is still a difficult and unsolved problem, in particular for non-steady state locomotion, that is, when the robot has to move in a complex environment with continuous variations of the speed, direction, and type of locomotor behavior. In this article we address the problem of controlling the non-steady state swimming and crawling of a novel fish robot. For this, we have designed a control architecture based on a central ...

  8. [Chlorine concentrations in the air of indoor swimming pools and their effects on swimming pool workers].

    Science.gov (United States)

    Fernández-Luna, Álvaro; Burillo, Pablo; Felipe, José Luis; Gallardo, Leonor; Tamaral, Francisco Manuel

    2013-01-01

    To describe chlorine levels in the air of indoor swimming pools in Castilla-La Mancha (Spain) and relate them to other chemical parameters in the installation and to the health problems perceived by swimming pool workers. We analyzed 21 pools with chlorine as chemical treatment in Castilla-La Mancha. The iodometry method was applied to measure chlorine concentrations in the air. The concentrations of free and combined chlorine in water, pH and temperature were also evaluated. Health problems were surveyed in 230 swimming pool workers in these facilities. The mean chlorine level in the air of swimming pools was 4.3 ± 2.3mg/m(3). The pH values were within the legal limits. The temperature parameters did not comply with regulations in 17 of the 21 pools analyzed. In the pools where chlorine values in the air were above the legal regulations, a significantly higher percentage of swimming pool workers perceived eye irritation, dryness and irritation of skin, and ear problems. Chlorine values in the air of indoor swimming pools were higher than those reported in similar studies. Most of the facilities (85%) exceeded the concentration of 1.5mg/m(3) established as the limit for the risk of irritating effects. The concentration of chlorine in indoor swimming pool air has a direct effect on the self-perceived health problems of swimming pool workers. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

  9. Speed mathematics

    CERN Document Server

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  10. Influence of robotic shoal size, configuration, and activity on zebrafish behavior in a free-swimming environment.

    Science.gov (United States)

    Butail, Sachit; Polverino, Giovanni; Phamduy, Paul; Del Sette, Fausto; Porfiri, Maurizio

    2014-12-15

    In animal studies, robots have been recently used as a valid tool for testing a wide spectrum of hypotheses. These robots often exploit visual or auditory cues to modulate animal behavior. The propensity of zebrafish, a model organism in biological studies, toward fish with similar color patterns and shape has been leveraged to design biologically inspired robots that successfully attract zebrafish in preference tests. With an aim of extending the application of such robots to field studies, here, we investigate the response of zebrafish to multiple robotic fish swimming at different speeds and in varying arrangements. A soft real-time multi-target tracking and control system remotely steers the robots in circular trajectories during the experimental trials. Our findings indicate a complex behavioral response of zebrafish to biologically inspired robots. More robots produce a significant change in salient measures of stress, with a fast robot swimming alone causing more freezing and erratic activity than two robots swimming slowly together. In addition, fish spend more time in the proximity of a robot when they swim far apart than when the robots swim close to each other. Increase in the number of robots also significantly alters the degree of alignment of fish motion with a robot. Results from this study are expected to advance our understanding of robot perception by live animals and aid in hypothesis-driven studies in unconstrained free-swimming environments. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Swimming performance in surf: the influence of experience.

    Science.gov (United States)

    Tipton, M; Reilly, T; Rees, A; Spray, G; Golden, F

    2008-11-01

    This study tested the hypothesis (H1) that surf swimming involves a quantifiable experience component. Sixty-five beach lifeguards with (n = 35) and without surf experience (n = 30) completed: a best effort 200-m swim in a 25-m pool, a calm and a surf sea; an anthropometric survey; maximum effort 30-s swim bench test; 50-m pool swim (25 m underwater). In both groups, time to swim 200 m was slower in calm seas than in the pool and slower in surf than in either calm seas or the pool (p surf conditions (p surf experience as a predictor of surf swim time (R(2) = 0.32, p surf swimming. This limits the usefulness of pool swim times and other land-based tests as predictors of surf swimming performance. The hypothesis (H1) is accepted.

  12. Swimming as a Positive Moderator of Cognitive Aging: A Cross-Sectional Study with a Multitask Approach

    Directory of Open Access Journals (Sweden)

    Amira Abou-Dest

    2012-01-01

    Full Text Available This study examined whether regular swimming in older adults was related to better cognitive functioning and whether there were any global or selective positive effects of this physical activity (PA on cognition. The cognitive performances of three groups of sixteen volunteer participants (young adults, sedentary older adults, and older adults who regularly practice swimming were evaluated using a multitask approach. All participants performed a battery of ten tasks: two reaction time tasks assessing information processing speed and eight experimental tasks assessing three executive functions (EFs, (behavioral inhibition, working memory updating, and cognitive flexibility. The results showed that young adults performed significantly better than older adults on all examined cognitive functions. However, in older adults, regular swimming was related to better performance on the three EFs, but not on information processing speed. More precisely, five experimental tasks out of the eight tapping EFs were shown to be sensitive to positive effects from swimming practice. Finally, the demonstrated benefits of swimming on EFs were not necessarily linked to better cardiorespiratory fitness. The present findings illustrate the validity of using a multitask approach in examining the potential benefits of regular PA on cognitive aging.

  13. Swimming as a positive moderator of cognitive aging: a cross-sectional study with a multitask approach.

    Science.gov (United States)

    Abou-Dest, Amira; Albinet, Cédric T; Boucard, Geoffroy; Audiffren, Michel

    2012-01-01

    This study examined whether regular swimming in older adults was related to better cognitive functioning and whether there were any global or selective positive effects of this physical activity (PA) on cognition. The cognitive performances of three groups of sixteen volunteer participants (young adults, sedentary older adults, and older adults who regularly practice swimming) were evaluated using a multitask approach. All participants performed a battery of ten tasks: two reaction time tasks assessing information processing speed and eight experimental tasks assessing three executive functions (EFs), (behavioral inhibition, working memory updating, and cognitive flexibility). The results showed that young adults performed significantly better than older adults on all examined cognitive functions. However, in older adults, regular swimming was related to better performance on the three EFs, but not on information processing speed. More precisely, five experimental tasks out of the eight tapping EFs were shown to be sensitive to positive effects from swimming practice. Finally, the demonstrated benefits of swimming on EFs were not necessarily linked to better cardiorespiratory fitness. The present findings illustrate the validity of using a multitask approach in examining the potential benefits of regular PA on cognitive aging.

  14. Analysis of sex differences in open-water ultra-distance swimming performances in the FINA World Cup races in 5 km, 10 km and 25 km from 2000 to 2012.

    OpenAIRE

    Zingg, Matthias,; Rüst, Christoph,; Rosemann, Thomas; Lepers, Romuald; Knechtle, Beat

    2014-01-01

    International audience; BACKGROUND: The present study investigated the changes in swimming speeds and sex differences for elite male and female swimmers competing in 5 km, 10 km and 25 km open-water FINA World Cup races held between 2000 and 2012. METHODS: The changes in swimming speeds and sex differences across years were analysed using linear, non-linear, and multi-level regression analyses for the annual fastest and the annual ten fastest competitors. RESULTS: For the annual fastest, swim...

  15. Drag force and jet propulsion investigation of a swimming squid

    Directory of Open Access Journals (Sweden)

    Tabatabaei Mahdi

    2015-01-01

    Full Text Available In this study, CAD model of a squid was obtained by taking computer tomography images of a real squid. The model later placed into a computational domain to calculate drag force and performance of jet propulsion. The drag study was performed on the CAD model so that drag force subjected to real squid was revealed at squid’s different swimming speeds and comparison has been made with other underwater creatures (e.g., a dolphin, sea lion and penguin. The drag coefficient (referenced to total wetted surface area of squid is 0.0042 at Reynolds number 1.6x106 that is a %4.5 difference from Gentoo penguin. Besides, jet flow of squid was simulated to observe the flow region generated in the 2D domain utilizing dynamic mesh method to mimic the movement of squid’s mantle cavity.

  16. The kinematics of swimming and relocation jumps in copepod nauplii

    DEFF Research Database (Denmark)

    Borg, Marc Andersen; Bruno, Eleonora; Kiørboe, Thomas

    2012-01-01

    of pelagic copepods: Temora longicornis, Oithona davisae and Acartia tonsa. The kinematics of jumping is similar between the three species. Jumps result in a very erratic translation with no phase of passive coasting and the nauplii move backwards during recovery strokes. This is due to poorly synchronized...... recovery strokes and a low beat frequency relative to the coasting time scale. For the same reason, the propulsion efficiency of the nauplii is low. Given the universality of the nauplius body plan, it is surprising that they seem to be inefficient when jumping, which is different from the very efficient...... larger copepodites. A slow-swimming mode is only displayed by T. longicornis. In this mode, beating of the appendages results in the creation of a strong feeding current that is about 10 times faster than the average translation speed of the nauplius. The nauplius is thus essentially hovering when...

  17. Locomotion of free-swimming ghost knifefish: anal fin kinematics during four behaviors.

    Science.gov (United States)

    Youngerman, Eric D; Flammang, Brooke E; Lauder, George V

    2014-10-01

    The maneuverability demonstrated by the weakly electric ghost knifefish (Apteronotus albifrons) is a result of its highly flexible ribbon-like anal fin, which extends nearly three-quarters the length of its body and is composed of approximately 150 individual fin rays. To understand how movement of the anal fin controls locomotion we examined kinematics of the whole fin, as well as selected individual fin rays, during four locomotor behaviors executed by free-swimming ghost knifefish: forward swimming, backward swimming, heave (vertical) motion, and hovering. We used high-speed video (1000 fps) to examine the motion of the entire anal fin and we measured the three-dimensional curvature of four adjacent fin rays in the middle of the fin during each behavior to determine how individual fin rays bend along their length during swimming. Canonical discriminant analysis separated all four behaviors on anal fin kinematic variables and showed that forward and backward swimming behaviors contrasted the most: forward behaviors exhibited a large anterior wavelength and posterior amplitude while during backward locomotion the anal fin exhibited both a large posterior wavelength and anterior amplitude. Heave and hover behaviors were defined by similar kinematic variables; however, for each variable, the mean values for heave motions were generally greater than for hovering. Individual fin rays in the middle of the anal fin curved substantially along their length during swimming, and the magnitude of this curvature was nearly twice the previously measured maximum curvature for ray-finned fish fin rays during locomotion. Fin rays were often curved into the direction of motion, indicating active control of fin ray curvature, and not just passive bending in response to fluid loading. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Application of regression and neural models to predict competitive swimming performance.

    Science.gov (United States)

    Maszczyk, Adam; Roczniok, Robert; Waśkiewicz, Zbigniew; Czuba, Miłosz; Mikołajec, Kazimierz; Zajac, Adam; Stanula, Arkadiusz

    2012-04-01

    This research problem was indirectly but closely connected with the optimization of an athlete-selection process, based on predictions viewed as determinants of future successes. The research project involved a group of 249 competitive swimmers (age 12 yr., SD = 0.5) who trained and competed for four years. Measures involving fitness (e.g., lung capacity), strength (e.g., standing long jump), swimming technique (turn, glide, distance per stroke cycle), anthropometric variables (e.g., hand and foot size), as well as specific swimming measures (speeds in particular distances), were used. The participants (n = 189) trained from May 2008 to May 2009, which involved five days of swimming workouts per week, and three additional 45-min. sessions devoted to measurements necessary for this study. In June 2009, data from two groups of 30 swimmers each (n = 60) were used to identify predictor variables. Models were then constructed from these variables to predict final swimming performance in the 50 meter and 800 meter crawl events. Nonlinear regression models and neural models were built for the dependent variable of sport results (performance at 50m and 800m). In May 2010, the swimmers' actual race times for these events were compared to the predictions created a year prior to the beginning of the experiment. Results for the nonlinear regression models and perceptron networks structured as 8-4-1 and 4-3-1 indicated that the neural models overall more accurately predicted final swimming performance from initial training, strength, fitness, and body measurements. Differences in the sum of absolute error values were 4:11.96 (n = 30 for 800m) and 20.39 (n = 30 for 50m), for models structured as 8-4-1 and 4-3-1, respectively, with the neural models being more accurate. It seems possible that such models can be used to predict future performance, as well as in the process of recruiting athletes for specific styles and distances in swimming.

  19. Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis.

    Science.gov (United States)

    Mooney, Robert; Quinlan, Leo R; Corley, Gavin; Godfrey, Alan; Osborough, Conor; ÓLaighin, Gearóid

    2017-01-01

    The study aims were to evaluate the validity of two commercially available swimming activity monitors for quantifying temporal and kinematic swimming variables. Ten national level swimmers (5 male, 5 female; 15.3±1.3years; 164.8±12.9cm; 62.4±11.1kg; 425±66 FINA points) completed a set protocol comprising 1,500m of swimming involving all four competitive swimming strokes. Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed. Video recordings were also obtained and used as a criterion measure to evaluate performance. A significant positive correlation was found between the monitors and video for the identification of each of the four swim strokes (Garmin: X2 (3) = 31.292, pGarmin: bias -0.065, 95% confidence intervals -3.828-6.920; Finis bias -0.02, 95% confidence intervals -3.095-3.142). However laps performed at the beginning and end of an interval were not as accurately timed. Additionally, a statistical difference was found for stroke count measurements in all but two occasions (p<0.05). These differences affect the accuracy of stroke rate, stroke length and average speed scores reported by the monitors, as all of these are derived from lap times and stroke counts. Both monitors were found to operate with a relatively similar performance level and appear suited for recreational use. However, issues with feature detection accuracy may be related to individual variances in stroke technique. It is reasonable to expect that this level of error would increase when the devices are used by recreational swimmers rather than elite swimmers. Further development to improve accuracy of feature detection algorithms, specifically for lap time and stroke count, would also increase their suitability within competitive settings.

  20. CeleST: computer vision software for quantitative analysis of C. elegans swim behavior reveals novel features of locomotion.

    Directory of Open Access Journals (Sweden)

    Christophe Restif

    2014-07-01

    Full Text Available In the effort to define genes and specific neuronal circuits that control behavior and plasticity, the capacity for high-precision automated analysis of behavior is essential. We report on comprehensive computer vision software for analysis of swimming locomotion of C. elegans, a simple animal model initially developed to facilitate elaboration of genetic influences on behavior. C. elegans swim test software CeleST tracks swimming of multiple animals, measures 10 novel parameters of swim behavior that can fully report dynamic changes in posture and speed, and generates data in several analysis formats, complete with statistics. Our measures of swim locomotion utilize a deformable model approach and a novel mathematical analysis of curvature maps that enable even irregular patterns and dynamic changes to be scored without need for thresholding or dropping outlier swimmers from study. Operation of CeleST is mostly automated and only requires minimal investigator interventions, such as the selection of videotaped swim trials and choice of data output format. Data can be analyzed from the level of the single animal to populations of thousands. We document how the CeleST program reveals unexpected preferences for specific swim "gaits" in wild-type C. elegans, uncovers previously unknown mutant phenotypes, efficiently tracks changes in aging populations, and distinguishes "graceful" from poor aging. The sensitivity, dynamic range, and comprehensive nature of CeleST measures elevate swim locomotion analysis to a new level of ease, economy, and detail that enables behavioral plasticity resulting from genetic, cellular, or experience manipulation to be analyzed in ways not previously possible.

  1. Strong static magnetic fields elicit swimming behaviors consistent with direct vestibular stimulation in adult zebrafish.

    Directory of Open Access Journals (Sweden)

    Bryan K Ward

    Full Text Available Zebrafish (Danio rerio offer advantages as model animals for studies of inner ear development, genetics and ototoxicity. However, traditional assessment of vestibular function in this species using the vestibulo-ocular reflex requires agar-immobilization of individual fish and specialized video, which are difficult and labor-intensive. We report that using a static magnetic field to directly stimulate the zebrafish labyrinth results in an efficient, quantitative behavioral assay in free-swimming fish. We recently observed that humans have sustained nystagmus in high strength magnetic fields, and we attributed this observation to magnetohydrodynamic forces acting on the labyrinths. Here, fish were individually introduced into the center of a vertical 11.7T magnetic field bore for 2-minute intervals, and their movements were tracked. To assess for heading preference relative to a magnetic field, fish were also placed in a horizontally oriented 4.7T magnet in infrared (IR light. A sub-population was tested again in the magnet after gentamicin bath to ablate lateral line hair cell function. Free-swimming adult zebrafish exhibited markedly altered swimming behavior while in strong static magnetic fields, independent of vision or lateral line function. Two-thirds of fish showed increased swimming velocity or consistent looping/rolling behavior throughout exposure to a strong, vertically oriented magnetic field. Fish also demonstrated altered swimming behavior in a strong horizontally oriented field, demonstrating in most cases preferred swimming direction with respect to the field. These findings could be adapted for 'high-throughput' investigations of the effects of environmental manipulations as well as for changes that occur during development on vestibular function in zebrafish.

  2. Fish Swimming and Bird/Insect Flight

    Science.gov (United States)

    Wu, Theodore Yaotsu

    2011-01-01

    This expository review is devoted to fish swimming and bird/insect flight. (a) The simple waving motion of an elongated flexible ribbon plate of constant width propagating a wave distally down the plate to swim forward in a fluid, initially at rest, is first considered to provide a fundamental concept on energy conservation. It is generalized to include variations in body width and thickness, with appended dorsal, ventral and caudal fins shedding vortices to closely simulate fish swimming, for which a nonlinear theory is presented for large-amplitude propulsion. (b) For bird flight, the pioneering studies on oscillatory rigid wings are discussed with delineating a fully nonlinear unsteady theory for a two-dimensional flexible wing with arbitrary variations in shape and trajectory to provide a comparative study with experiments. (c) For insect flight, recent advances are reviewed by items on aerodynamic theory and modeling, computational methods, and experiments, for forward and hovering flights with producing leading-edge vortex to yield unsteady high lift. (d) Prospects are explored on extracting prevailing intrinsic flow energy by fish and bird to enhance thrust for propulsion. (e) The mechanical and biological principles are drawn together for unified studies on the energetics in deriving metabolic power for animal locomotion, leading to the surprising discovery that the hydrodynamic viscous drag on swimming fish is largely associated with laminar boundary layers, thus drawing valid and sound evidences for a resounding resolution to the long-standing fish-swim paradox proclaimed by Gray (1936, 1968 ).

  3. Swimming Pool Electrical Injuries: Steps Toward Prevention.

    Science.gov (United States)

    Tashiro, Jun; Burnweit, Cathy A

    2017-01-09

    Electrical injuries in swimming pools are an important pediatric public health concern. We sought to (1) improve our understanding of the clinical presentation and outcomes following and (2) describe the epidemiology of swimming pool electrical injuries in the United States. We reviewed 4 cases of pediatric (public (23.9%) and sports facilities (19.1%). Electrical outlets or receptacles (39.8%) were most commonly implicated, followed by electrical system doors (18.2%), electric wiring systems (17.0%), thermostats (16.3%), hair dryers (4.6%), and radios (4.1%). Pediatric cases represented 48.4% of swimming pool-related electrical injuries reported to NEISS. Electrical injuries occurring in and around swimming pools remain an important source of morbidity and mortality. Although NEISS monitors sentinel events, current efforts at preventing such cases are less than adequate. All electrical outlets near swimming pools should be properly wired with ground fault circuit interrupter devices. Possible approaches to increasing safe electrical device installation are through strengthening public awareness and education of the potential for injury, as well as changes to current inspection regulations.

  4. Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis.

    Directory of Open Access Journals (Sweden)

    Robert Mooney

    Full Text Available The study aims were to evaluate the validity of two commercially available swimming activity monitors for quantifying temporal and kinematic swimming variables.Ten national level swimmers (5 male, 5 female; 15.3±1.3years; 164.8±12.9cm; 62.4±11.1kg; 425±66 FINA points completed a set protocol comprising 1,500m of swimming involving all four competitive swimming strokes. Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed. Video recordings were also obtained and used as a criterion measure to evaluate performance.A significant positive correlation was found between the monitors and video for the identification of each of the four swim strokes (Garmin: X2 (3 = 31.292, p<0.05; Finis:X2 (3 = 33.004, p<0.05. No significant differences were found for swim distance measurements. Swimming laps performed in the middle of a swimming interval showed no significant difference from the criterion (Garmin: bias -0.065, 95% confidence intervals -3.828-6.920; Finis bias -0.02, 95% confidence intervals -3.095-3.142. However laps performed at the beginning and end of an interval were not as accurately timed. Additionally, a statistical difference was found for stroke count measurements in all but two occasions (p<0.05. These differences affect the accuracy of stroke rate, stroke length and average speed scores reported by the monitors, as all of these are derived from lap times and stroke counts.Both monitors were found to operate with a relatively similar performance level and appear suited for recreational use. However, issues with feature detection accuracy may be related to individual variances in stroke technique. It is reasonable to expect that this level of error would increase when the devices are used by recreational swimmers rather than elite swimmers. Further development to improve

  5. Ontogenetic changes in larval swimming and orientation of pre-competent sea urchin Arbacia punctulata in turbulence.

    Science.gov (United States)

    Wheeler, Jeanette D; Chan, Kit Yu Karen; Anderson, Erik J; Mullineaux, Lauren S

    2016-05-01

    Many marine organisms have complex life histories, having sessile adults and relying on the planktonic larvae for dispersal. Larvae swim and disperse in a complex fluid environment and the effect of ambient flow on larval behavior could in turn impact their survival and transport. However, to date, most studies on larvae-flow interactions have focused on competent larvae near settlement. We examined the importance of flow on early larval stages by studying how local flow and ontogeny influence swimming behavior in pre-competent larval sea urchins, Arbacia punctulata We exposed larval urchins to grid-stirred turbulence and recorded their behavior at two stages (4- and 6-armed plutei) in three turbulence regimes. Using particle image velocimetry to quantify and subtract local flow, we tested the hypothesis that larvae respond to turbulence by increasing swimming speed, and that the increase varies with ontogeny. Swimming speed increased with turbulence for both 4- and 6-armed larvae, but their responses differed in terms of vertical swimming velocity. 4-Armed larvae swam most strongly upward in the unforced flow regime, while 6-armed larvae swam most strongly upward in weakly forced flow. Increased turbulence intensity also decreased the relative time that larvae spent in their typical upright orientation. 6-Armed larvae were tilted more frequently in turbulence compared with 4-armed larvae. This observation suggests that as larvae increase in size and add pairs of arms, they are more likely to be passively re-oriented by moving water, rather than being stabilized (by mechanisms associated with increased mass), potentially leading to differential transport. The positive relationship between swimming speed and larval orientation angle suggests that there was also an active response to tilting in turbulence. Our results highlight the importance of turbulence to planktonic larvae, not just during settlement but also in earlier stages through morphology-flow interactions

  6. Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

    Science.gov (United States)

    Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge

    2013-01-01

    Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

  7. Determinant kinantropometric factors in swimming

    Directory of Open Access Journals (Sweden)

    João Paulo Vilas-Boas

    2002-12-01

    Full Text Available The aim of this work is to present a bibliographic review, based on the specialized literature, of the kineantropometric characteristics of swimmers and their importance for swimming performance. The main conclusions were: (i swimmers are taller and heavier than the general population; (ii swimmers present an high index of arm span/height (explained by a large biacromial diameter and long the upper arm; (iii high values for the biacromial/bicristal diameter ratio were found, offering a lower drag coeffi cient; (iv high length and surface area arm and leg values were observed (which positively infl uence their propulsion capacity; (v elite male swimmers presents a ectomorph-endomorph somatotype and elite female swimmers are central or balanced mesomorphs (vi swimmers exhibit a higher percentage of body mass than other athletes, which may benefi t positively their floatation. RESUMO O objetivo deste trabalho é apresentar uma revisão bibliográfi ca das principais características cineantropométricas do nadador e a forma como estas infl uenciam a sua prestação na modalidade. As principais conclusões obtidas foram as seguintes: (i os nadadores são mais altos e pesados do que a população em geral; (ii os nadadores apresentam um elevado índice envergadura/ altura, explicitando valores elevados do diâmetro biacromial e do comprimento dos MS; (iii verifi ca-se uma elevada razão entre os diâmetros biacromial e bicristal, traduzindo um fator decisivo na modalidade: a promoção de um coefi ciente de arrasto inferior; (iv foram observados elevados valores de comprimento e superfície dos membros dos nadadores (afetando positivamente a sua capacidade propulsiva; (v os nadadores de elite apresentam um somatótipo médio ecto-mesomorfo e as nadadoras são centrais ou mesomorfas equilibradas; (vi como grupo, os nadadores apresentam um maior percentual de massa gorda do que outros desportistas, fator este que poderá beneficiálos relativamente

  8. An integrative CFD model of lamprey swimming

    Science.gov (United States)

    Hsu, Chia-Yu; McMillen, Tyler; Fauci, Lisa

    2008-11-01

    Swimming due to sinusoidal body undulations is observed across the full spectrum of swimming organisms, from microscopic flagella to fish. These undulations are achieved due to internal force-generating mechanisms, which, in the case of lamprey are due to a wave of neural activation from head to tail which gives rise to a wave of muscle activation. These active forces are also mediated by passive structural forces. Here we present recent results on a computational model of a swimming lamprey that couples activation of discrete muscle segments, passive elastic forces, and a surrounding viscous, incompressible fluid. The fluid dynamics is modeled by the Navier-Stokes equations at appropriate Reynolds numbers, where the resulting flow field and vortex shedding may be measured.

  9. Flow analysis of C. elegans swimming

    Science.gov (United States)

    Montenegro-Johnson, Thomas; Gagnon, David; Arratia, Paulo; Lauga, Eric

    2015-11-01

    Improved understanding of microscopic swimming has the potential to impact numerous biomedical and industrial processes. A crucial means of analyzing these systems is through experimental observation of flow fields, from which it is important to be able to accurately deduce swimmer physics such as power consumption, drag forces, and efficiency. We examine the swimming of the nematode worm C. elegans, a model system for undulatory micro-propulsion. Using experimental data of swimmer geometry and kinematics, we employ the regularized stokeslet boundary element method to simulate the swimming of this worm outside the regime of slender-body theory. Simulated flow fields are then compared with experimentally extracted values confined to the swimmer beat plane, demonstrating good agreement. We finally address the question of how to estimate three-dimensional flow information from two-dimensional measurements.

  10. Particle Image Velocimetry Around Swimming Paramecia

    Science.gov (United States)

    Giarra, Matthew; Jana, Saikat; Jung, Sunghwan; Vlachos, Pavlos

    2011-11-01

    Microorganisms like paramecia propel themselves by synchronously beating thousands of cilia that cover their bodies. Using micro-particle image velocimetry (μPIV), we quantitatively measured velocity fields created by the movement of Paramecium multimicronucleatum through a thin (~100 μm) film of water. These velocity fields exhibited different features during different swimming maneuvers, which we qualitatively categorized as straight forward, turning, or backward motion. We present the velocity fields measured around organisms during each type of motion, as well as calculated path lines and fields of vorticity. For paramecia swimming along a straight path, we observed dipole-like flow structures that are characteristic of a prolate-spheroid translating axially in a quiescent fluid. Turning and backward-swimming organisms showed qualitatively different patterns of vortices around their bodies. Finally, we offer hypotheses about the roles of these different flow patterns in the organism's ability to maneuver.

  11. Virulent Naegleria fowleri in indoor swimming pool.

    Science.gov (United States)

    Kadlec, V; Skvárová, J; Cerva, L; Nebáznivá, D

    1980-01-01

    Naegleria fowleri was isolated from water during a hygienic inspection of a swimming pool in December 1977. This swimming pool was identified as a source of the infectious agent in the years 1962-1965, when a large outbreak of primary amoebic meningoencephalitis (PAME) occurred. First two strains of N. fowleri, pathogenic for white mice after intracerebral and intranasal inoculation, were isolated from water of outlet troughs, additional strains were then isolated from various places; particularly from a cavity in the damaged wall of the pool. The incubation temperature did not inhibit a simultaneous growth of amoebae of the genera Acanthamoeba, Flabellula, Hartmannella and Vahlkampfia in the primocultures. Epidemiological investigations did not reveal any new case of PAME in relation with the occurrence of pathogenic N. fowleri in the swimming pool.

  12. Muscle dynamics in fish during steady swimming

    DEFF Research Database (Denmark)

    Shadwick, RE; Steffensen, JF; Katz, SL

    1998-01-01

    SYNOPSIS. Recent research in fish locomotion has been dominated by an interest in the dynamic mechanical properties of the swimming musculature. Prior observations have indicated that waves of muscle activation travel along the body of an undulating fish faster than the resulting waves of muscular...... contraction, suggesting that the phase relation between the muscle strain cycle and its activation must vary along the body. Since this phase relation is critical in determining how the muscle performs in cyclic contractions, the possibility has emerged that dynamic muscle function may change with axial...... position in swimming fish. Quantification of muscle contractile properties in cyclic contractions relies on in vitro experiments using strain and activation data collected in vivo. In this paper we discuss the relation between these parameters and body kinematics. Using videoradiographic data from swimming...

  13. Energetics of swimming of schooling fish

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2012-01-01

    , i.e. nearest neighbour distance, water temperature, gill oxygen extraction, gill ventilation capacity, etc. Fish swimming in a school have been shown to have energetic advantages when trailing behind neighbours, resulting in up to 20% energy saving. The effect of this energy saving is that the fish......Soc for experimental Biol Annual Meeting - Salzburg 2012 John F. Steffensen (University of Copenhagen, Denmark) When a fish school swims through the water, every individual consumes a certain amount of oxygen, which means that less will be available for the trailing fish in the school. In 1967 Mc......Farland and Moss reported that the oxygen saturation decreased approximately 30% from the front to the rear of an approximately 150-m long school of mullets swimming in normoxic water. They also observed that the decline in oxygen saturation at the rear resulted in the school disintegrating into smaller separate...

  14. Analysis of swimming performance: perceptions and practices of US-based swimming coaches.

    Science.gov (United States)

    Mooney, Robert; Corley, Gavin; Godfrey, Alan; Osborough, Conor; Newell, John; Quinlan, Leo Richard; ÓLaighin, Gearóid

    2016-01-01

    In elite swimming, a broad range of methods are used to assess performance, inform coaching practices and monitor athletic progression. The aim of this paper was to examine the performance analysis practices of swimming coaches and to explore the reasons behind the decisions that coaches take when analysing performance. Survey data were analysed from 298 Level 3 competitive swimming coaches (245 male, 53 female) based in the United States. Results were compiled to provide a generalised picture of practices and perceptions and to examine key emerging themes. It was found that a disparity exists between the importance swim coaches place on biomechanical analysis of swimming performance and the types of analyses that are actually conducted. Video-based methods are most frequently employed, with over 70% of coaches using these methods at least monthly, with analyses being mainly qualitative in nature rather than quantitative. Barriers to the more widespread use of quantitative biomechanical analysis in elite swimming environments were explored. Constraints include time, cost and availability of resources, but other factors such as sources of information on swimming performance and analysis and control over service provision are also discussed, with particular emphasis on video-based methods and emerging sensor-based technologies.

  15. Determination of a quantitative parameter to evaluate swimming technique based on the maximal tethered swimming test.

    Science.gov (United States)

    Soncin, Rafael; Mezêncio, Bruno; Ferreira, Jacielle Carolina; Rodrigues, Sara Andrade; Huebner, Rudolf; Serrão, Julio Cerca; Szmuchrowski, Leszek

    2017-06-01

    The aim of this study was to propose a new force parameter, associated with swimmers' technique and performance. Twelve swimmers performed five repetitions of 25 m sprint crawl and a tethered swimming test with maximal effort. The parameters calculated were: the mean swimming velocity for crawl sprint, the mean propulsive force of the tethered swimming test as well as an oscillation parameter calculated from force fluctuation. The oscillation parameter evaluates the force variation around the mean force during the tethered test as a measure of swimming technique. Two parameters showed significant correlations with swimming velocity: the mean force during the tethered swimming (r = 0.85) and the product of the mean force square root and the oscillation (r = 0.86). However, the intercept coefficient was significantly different from zero only for the mean force, suggesting that although the correlation coefficient of the parameters was similar, part of the mean velocity magnitude that was not associated with the mean force was associated with the product of the mean force square root and the oscillation. Thus, force fluctuation during tethered swimming can be used as a quantitative index of swimmers' technique.

  16. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Science.gov (United States)

    Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

    2017-01-01

    ABSTRACT Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. PMID:28302669

  17. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Directory of Open Access Journals (Sweden)

    Fan Jizhuang

    2017-04-01

    Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

  18. Biological implications of the hydrodynamics of swimming at or near the surface and in shallow water

    Energy Technology Data Exchange (ETDEWEB)

    Blake, R W [Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada)], E-mail: blake@zoology.ubc.ca

    2009-03-01

    The origins and effects of wave drag at and near the surface and in shallow water are discussed in terms of the dispersive waves generated by streamlined technical bodies of revolution and by semi-aquatic and aquatic animals with a view to bearing on issues regarding the design and function of autonomous surface and underwater vehicles. A simple two-dimensional model based on energy flux, allowing assessment of drag and its associated wave amplitude, is applied to surface swimming in Lesser Scaup ducks and is in good agreement with measured values. It is argued that hydrodynamic limitations to swimming at speeds associated with the critical Froude number ({approx}0.5) and hull speed do not necessarily set biological limitations as most behaviours occur well below the hull speed. From a comparative standpoint, the need for studies on the hull displacement of different forms is emphasized. For forms in surface proximity, drag is a function of both Froude and Reynolds numbers. Whilst the depth dependence of wave drag is not particularly sensitive to Reynolds number, its magnitude is, with smaller and slower forms subject to relatively less drag augmentation than larger, faster forms that generate additional resistance due to ventilation and spray. A quasi-steady approach to the hydrodynamics of swimming in shallow water identifies substantial drag increases relative to the deeply submerged case at Froude numbers of about 0.9 that could limit the performance of semi-aquatic and aquatic animals and autonomous vehicles. A comparative assessment of fast-starting trout and upside down catfish shows that the energy losses of fast-starting fish are likely to be less for fish in surface proximity in deep water than for those in shallow water. Further work on unsteady swimming in both circumstances is encouraged. Finally, perspectives are offered as to how autonomous surface and underwater vehicles in surface proximity and shallow water could function to avoid prohibitive

  19. A wake-based correlate of swimming performance in seven jellyfish species

    Science.gov (United States)

    Dabiri, John; Colin, Sean; Katija, Kakani; Costello, John

    2009-11-01

    Animal-fluid interactions have been hypothesized as a principal selective pressure on the evolution of aquatic and aerial animals. However, attempts to discover the fluid dynamic mechanisms that dictate the fitness of an animal---or even to quantify `fitness'---have been limited by an inability to measure the fluid interactions of freely moving animals (i.e., in the absence of tethers or artificial water/wind currents) in comparative studies of multiple species with similar evolutionary histories. We used digital particle image velocimetry (DPIV) measurements to calculate wake kinetic energy, drag, and swimming speed of the seven co-occurring species of free-swimming jellyfish. Using this new data, we demonstrate that the swimming and foraging behavior are related to a robust fluid dynamic threshold between two distinct configurations of the wake vortices. The transition between the two wake vortex configurations is known as optimal vortex formation, because it maximizes the fluid dynamic thrust generated for a given energy input (Krueger and Gharib, Phys. Fluids 2003). By comparing the observed wake structures created by each jellyfish species with the optimal vortex configuration, we are able to predict their relative swimming efficiencies and proficiencies and to deduce their corresponding ecological niches.

  20. Undulatory swimming in shear-thinning fluids: Experiments with Caenorhabditis elegans

    Science.gov (United States)

    Gagnon, David; Arratia, Paulo

    2015-11-01

    The swimming behavior of microorganisms can be strongly affected by the rheology of their fluidic environment. In this talk, we experimentally investigate the swimming behavior of the nematode Caenorhabditis elegans (~1 mm length, 80 μm diameter) in shear-thinning fluids using tracking and velocimetry methods. We find substantial differences in the resulting flow fields between the shear-thinning and Newtonian cases, even though the swimming kinematics (e.g. speed and frequency) remain similar. For example, velocimetry data show that shear-thinning viscosity enhances vorticity and increases circulation near the strongest body vortex, located near the head of the nematode. These findings are in good agreement with recent theoretical and numerical results. We then estimate the local viscosity around the swimmer, measure the spatial decay of the flow field, and estimate the mechanical power (i.e. viscous dissipation) due to the worm's motion in shear-thinning fluids. We find that the flow decays more slowly in shear-thinning fluids than in Newtonian fluids, but the resulting mechanical power is approximately the same for swimming in shear-thinning fluids when compared to the Newtonian case.

  1. Swimming-based pica in rats.

    Science.gov (United States)

    Nakajima, Sadahiko

    2016-09-01

    We have recently demonstrated that voluntary or forced running in activity wheels yields pica behavior (kaolin clay intake) in rats (Nakajima, 2016; Nakajima and Katayama, 2014). The present study provides experimental evidence that a single 40-min session of swimming in water also generates pica in rats, while showering rats with water does not produce such behavior. Because kaolin intake has been regarded as a measure of nausea in rats, this finding suggests that swimming activity, as well as voluntary or forced running, induces nausea in rats. Copyright © 2016. Published by Elsevier B.V.

  2. The Swimming Efficiency of Magnetotactic Bacteria

    Science.gov (United States)

    Newell, A. J.

    2005-12-01

    Magnetotactic bacteria are widespread in the oxic-anoxic transition zone (OATZ) of freshwater and marine sediments. They have chains of magnetic particles and exert a high degree of control over their synthesis. Evidently they find it worth the energy cost of synthesizing these particles. The existing model for magnetotaxis compare a one-dimensional search along a magnetic field line with the three-dimensional "run and tumble" behavior of bacteria like E. coli. However, this model is inadequate in more than one respect. First, a search along a field line is only advantageous for relatively steep field lines. Second, most bacterial moments are too small for the one-dimensional approximation to be accurate. Third, it will be shown that tumbling behavior is incompatible with at least one kind of magnetotaxis. Instead, all known magnetotactic bacteria can reverse their direction of swimming. Models are developed for the swimming efficiency of the two kinds of magnetotaxis identified by Frankel et al. (1997). These are polar and axial magneto-aerotaxis (MA), where aerotaxis is an energy-sensing behavior that helps the bacterium find the optimal oxygen concentration. In both kinds of taxis torque on the magnetic chains tends to align the bacteria with the Earth's field. This torque is countered by viscous drag and Brownian rotation. Polar MA has a switch-like response of swimming direction to the oxygen concentration. This type of aerotaxis also uses the direction of the magnetic field to determine which way to swim. In zero field or in a field with the wrong sign this mechanism fails. Axial MA uses a more conventional aerotaxis that responds to gradients in the energy or redox state. This mechanism works reasonably well even in zero field, and also for any field direction as long as the field is not too large. The swimming efficiency of magnetotactic bacteria is determined by two factors: a geometrical factor based on the distribution of bacterial orientations, and the

  3. REHABILITATION OF LUMBAR HYPERLORDOSIS THROUGH SWIMMING-SPECIFIC EXERCISES

    OpenAIRE

    Petrea Renato-Gabriel; Rusu Diana-Elena

    2014-01-01

    The purpose of this paper is to show the importance and utility of swimming within rehabilitation and therapeutic programs for posture deficiencies, in our context for the rehabilitation of lumbar hyperlordosis. We consider that, by using exercises specific to swimming and means specific to acquiring swimming procedures, we will reduce the range of lumbar hyperlordosis. More precisely, we believe that, through exercises specific to swimming, we will reduce the range of lumbar hyperlordosis by...

  4. Specifies of teaching swimming to children with autism spectrum disorder

    OpenAIRE

    Baštová, Miroslava

    2017-01-01

    Title: Specifics of teaching swimming to children with autism spectrum disorder. Objectives: Creation and implementation of the concept of preparatory and basic swimming lessons for children with autism spectrum disorder. Evaluation of information on continuing education and the achieved level of swimming skills and swimming locomotion observed in children with autism spectrum disorder. Presentation and qualitative assessment of the four case studies and subsequent design of guidelines for sw...

  5. Mitigating the impact of swimming pools on domestic water demand ...

    African Journals Online (AJOL)

    ... the impact that swimming pools have on domestic water demand. The results support the contention that properties with swimming pools use significantly more water than those without. This study estimated the additional demand resulting from swimming pools at between 2.2–2.4 kℓ/month or 7–8% of total water demand.

  6. Current Trends in Swimming Lessons of Preschool Children

    OpenAIRE

    Duspivová, Hana

    2010-01-01

    The thesis charts current options in preschool children swimming learning, organization, procedures, objectives and results achieved in specific groups through observation, interviews and questionnaires. The aim ofthe thesis was based on the observed data and recommended procedure to create its own methodology, which was verified by their own practice. Keywords Child, preschool age, swimming lessons (methods, procedures, organization), swimming methods.

  7. 76 FR 60732 - Drawbridge Operation Regulations; Navesink (Swimming) River, NJ

    Science.gov (United States)

    2011-09-30

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Navesink (Swimming) River, NJ AGENCY... the Oceanic Bridge at mile 4.5 across the Navesink (Swimming) River between Oceanic and Locust Point...-9826. SUPPLEMENTARY INFORMATION: The Oceanic Bridge, across the Navesink (Swimming) River, mile 4.5...

  8. Turns and maneuvers during swimming

    Science.gov (United States)

    Bhalla, Amneet; Mosberg, Noah; Bale, Rahul; Patankar, Neelesh

    2011-11-01

    In this work we use fully resolved fluid dynamics computations based on an immersed body approach to study fish turns and maneuvers. We present a numerical method to control the trajectory of fish during turns and maneuvers. Fish tracking a prey is presented as an example case. Numerical simulations are carried out on spatially adaptive grid for speed and accuracy. The effect of deformation kinematics and Reynolds number (Re), on the turn radius of an undulatory swimmer, is studied. Power spent during turning at different turn radii and Re is also reported. These results can be used to quantify the cost of various maneuvers and to identify efficient maneuvers to attain the same objective, e.g., reaching a target location during prey tracking. NSF support is gratefully acknowledged.

  9. Investigation of Thunniform Swimming Using Material Testing, Biomimetic Robotics and Particle Image Velocimetry

    Science.gov (United States)

    Zhu, Ruijie; Saraiya, Vishaal; Zhu, Jianzhong; Lewis, Gregory; Bart-Smith, Hilary

    2015-11-01

    Thunniform swimming is well recognized as an efficient method for high-speed long-distance underwater travelers such as tuna. Previous research has shown that tuna relies on contraction and relaxation of red muscle to generate angular motion of its large, crescent-shaped caudal fin through its peduncle. However, few researchers conduct deep investigation of material properties of tuna caudal fin and peduncle. This research project is composed of two parts, first of which is determining mechanical properties of components such as spine joints, tendons, fin rays and cartilage, from which the biomechanics of tuna tail can be better understood. The second part is building a robotic system mimicking a real tuna tail based on previously retrieved information, and testing the system inside a flow tank. With the help of PIV (Particle Image Velocimetry), fluid-structure interaction of the biomimetic fin is visualized and data such as swimming speed and power consumption are retrieved through the robotic system. The final outcome should explain how the material properties of tuna tail affect fluid dynamics of thunniform swimming. This project is supported by Office of Naval Research (ONRBAA13-022).

  10. The sustained speed of kill of ticks (Rhipicephalus sanguineus) and fleas (Ctenocephalides felis felis) on dogs by a spot-on combination of fipronil and permethrin (Effitix®) compared with oral afoxolaner (NexGard®).

    Science.gov (United States)

    Cvejić, Dejan; Schneider, Claudia; Neethling, Willem; Hellmann, Klaus; Liebenberg, Julian; Navarro, Christelle

    2017-08-30

    .05) on Days 7, 14 and 21. Flea efficacies, 24h after infestation were >98% and similar for both treated groups on all infestation days (P >0.05). The topically applied fipronil-permethrin containing ectoparasiticide Effitix ® offers rapid efficacy against R. sanguineus and C. felis which persists for one month after a single administration in dogs. Afoxolaner is also effective although speed of kill is slower. The rapid and sustained speed of kill of both parasites by fipronil-permethrin should contribute to effective management not only of these parasites and their direct adverse effects including irritancy and allergy, but also to reducing the risk of transmitting infections. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Front crawl swimming analysis using accelerometers

    DEFF Research Database (Denmark)

    Espinosa, Hugo G; Nordsborg, Nikolai Baastrup; Thiel, David V

    2015-01-01

    Biomechanical characteristics such as stroke rate and stroke length can be used to determine the velocity of a swimmer and can be analysed in both a swimming pool and a flume. The aim of the present preliminary study was to investigate the differences between the acceleration data collected from ...

  12. Fluid viscoelasticity promotes collective swimming of sperm.

    Science.gov (United States)

    Tung, Chih-Kuan; Lin, Chungwei; Harvey, Benedict; Fiore, Alyssa G; Ardon, Florencia; Wu, Mingming; Suarez, Susan S

    2017-06-09

    From flocking birds to swarming insects, interactions of organisms large and small lead to the emergence of collective dynamics. Here, we report striking collective swimming of bovine sperm in dynamic clusters, enabled by the viscoelasticity of the fluid. Sperm oriented in the same direction within each cluster, and cluster size and cell-cell alignment strength increased with viscoelasticity of the fluid. In contrast, sperm swam randomly and individually in Newtonian (nonelastic) fluids of low and high viscosity. Analysis of the fluid motion surrounding individual swimming sperm indicated that sperm-fluid interaction was facilitated by the elastic component of the fluid. In humans, as well as cattle, sperm are naturally deposited at the entrance to the cervix and must swim through viscoelastic cervical mucus and other mucoid secretions to reach the site of fertilization. Collective swimming induced by elasticity may thus facilitate sperm migration and contribute to successful fertilization. We note that almost all biological fluids (e.g. mucus and blood) are viscoelastic in nature, and this finding highlights the importance of fluid elasticity in biological function.

  13. Swimming Pools. Managing School Facilities, Guide 2.

    Science.gov (United States)

    Department for Education and Employment, London (England). Architects and Building Branch.

    This guide for schools with swimming pools offers advice concerning appropriate training for pool managers, the importance of water quality and testing, safety in the handling of chemicals, maintenance and cleaning requirements, pool security, and health concerns. The guide covers both indoor and outdoor pools, explains some technical terms,…

  14. Effect of winter swimming on haematological parameters.

    Science.gov (United States)

    Lombardi, Giovanni; Ricci, Cristian; Banfi, Giuseppe

    2011-01-01

    Winter swimming represents an intensive short-term exposure to cold, and thus it is considered a strong physical stress. Cold-based treatments, i.e. immersions in cold water, are spreading in sport medicine for improving recovery following muscle traumas, although a universal acceptance of that method is not still achieved. Fifteen healthy subjects (13 males and 2 females) were recruited among the participants to a 150 meters long swimming race in cold water (6 degrees C). Blood samples were collected the day before and immediately after the race and a panel of haematological parameters was evaluated. Swimming in cold water induced a significant variation in the blood cell fraction composition compared to the rest condition, as measured the day before the competition. Red blood cells, white blood cells and platelets count increased significantly (4.7%, P = 0.005; 40.6%, P mere haemoconcentration. When represented by brief exposure to cold water, winter swimming induces strong non-pathological modifications of haematological homeostasis.

  15. The Chemistry of Swimming Pool Maintenance

    Science.gov (United States)

    Salter, Carl; Langhus, David L.

    2007-01-01

    The study of chemistry involved in the maintenance of a swimming pool provides a lot of chemical education to the students, including the demonstration of the importance of pH in water chemistry. The various chemical aspects hidden in the maintenance of the pool are being described.

  16. Quiet swimming at low Reynolds number

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Wadhwa, Navish; Kiørboe, Thomas

    2015-01-01

    -Stokeslet model of a swimming organism which uses breast stroke type kinematics is an example of such a quiet swimmer. We show that the fluid disturbance in both the near field and the far field is significantly reduced by appropriately arranging the propulsion apparatus, and we find that the far field power laws...

  17. Hydrodynamics of undulatory underwater swimming: a review.

    Science.gov (United States)

    Connaboy, Chris; Coleman, Simon; Sanders, Ross H

    2009-11-01

    Undulatory underwater swimming (UUS) occurs in the starts and turns of three of the four competitive swimming strokes and plays a significant role in overall swimming performance. The majority of research examining UUS is comparative in nature, dominated by studies comparing aquatic animals' undulatory locomotion with the UUS performance of humans. More recently, research directly examining human forms of UUS have been undertaken, providing further insight into the factors which influence swimming velocity and efficiency. This paper reviews studies which have examined the hydromechanical, biomechanical, and coordination aspects of UUS performance in both animals and humans. The present work provides a comprehensive evaluation of the key factors which combine to influence UUS performance examining (1) the role of end-effector frequency and body amplitudes in the production of a propulsive waveform, (2) the effects of morphology on the wavelength of the propulsive waveform and its subsequent impact on the mode of UUS adopted, and (3) the interactions of the undulatory movements to simultaneously optimise propulsive impulse whilst minimising the active drag experienced. In conclusion, the review recommends that further research is required to fully appreciate the complexity of UUS and examine how humans can further optimise performance.

  18. What Research Tells the Coach About Swimming.

    Science.gov (United States)

    Faulkner, John A.

    This booklet is designed to make research findings about swimming available with interpretations for practical application. Chapter 1, "Physical Characteristics of Swimmers," discusses somatotyping, body composition, and growth. Chapter 2, "Physiological Characteristics of Swimmers," discusses resting rate, vital capacity, effects of water…

  19. [Lumbar hypermobility: where swimming becomes hydrotherapy].

    Science.gov (United States)

    Mergeay, D; De Neve, M

    1990-01-01

    In this paper the authors discuss the clinical problem of lumbar hypermobility. The therapeutical possibilities are resumed briefly. The philosophy of medical training therapy ("Heilgymnastik") is described. More extensive the extra-advantages of hydrotherapy (methodical back-stroke swimming) are searched for in a theoretical deductive way. The authors found that: 1. swimming is a low-impact sport so far as the articulations are concerned, 2. back-stroke is done mainly in a lumbar kyphosis, 3. swimming is also an excellent cardiopulmonary training, 4. when swimming the muscles of the shoulder girdle and pelvic girdle are trained in a nearly isokinetic way (power-endurance), 5. the short transverso-spinal muscles are indirectly trained in their tonic more than phasic stretch reflex (posture function), 6. the muscles of the trunk are trained in a nearly isometric way in the appropriate angles (erect position), 7. the position of the head in the water facilitates the abdominal muscles (tonic neck reflex), 8. the cool temperature of the water generates training-enhancing stress-responses, 9. endurance-training is ideal for the postural function of the lower back muscles (especially the deeper layers near the spine) which are anatomical and physiological suited for this purpose, 10. warming-up and cooling-down procedures prepare the neuromuscular, the cardiovascular and metabolic functions before the workout-session (a cold shower afterwards acts to tonicize the skin and muscles).

  20. Surveillance and Conformity in Competitive Youth Swimming

    Science.gov (United States)

    Lang, Melanie

    2010-01-01

    Underpinned by a Foucauldian analysis of sporting practices, this paper identifies the disciplinary mechanism of surveillance at work in competitive youth swimming. It highlights the ways in which swimmers and their coaches are subject to and apply this mechanism to produce embodied conformity to normative behaviour and obedient, docile bodies.…

  1. Healthy Swimming Is a Partnership Effort

    Science.gov (United States)

    Grosse, Susan J.

    2009-01-01

    While one cannot control the water chemistry, he/she can control personal hygiene and facility cleanliness. Giardia and cryptosporidium (crypto) are only two of the many recreational water illnesses (RWIs) that can turn happy swim memories into serious illness situations. In this article, the author discusses three factors that determine how…

  2. Swimming overuse injuries associated with triathlon training.

    Science.gov (United States)

    Bales, James; Bales, Karrn

    2012-12-01

    Most triathlon overuse injuries occur due to the running and cycling aspects of the sport. By nature of swimming being a non-weight-bearing sport, triathletes have a tendency to use swimming for rehabilitation and recovery. Swimming has a significantly lower injury rate than the other 2 disciplines in a triathlon. Most triathletes use the freestyle stroke, because it is typically the first stroke learned, it is for many the fastest stroke, and by lifting the head the freestyle stroke allows triathletes to sight their direction, which is important in open water swimming. During the freestyle stroke, the shoulder undergoes repetitive overhead motion, and shoulder pain is the most common and well-documented site of musculoskeletal pain in competitive swimmers. It is felt that the pathologic process is attributable to repetitive overhead motion causing microtrauma in the shoulder from either mechanical impingement or generalized laxity or both. Without sufficient rest and recovery, the development of inflammation and pain may result. Depending on the age of the triathlete and the exact etiology of the shoulder pain, treatment options range from nonsurgical to surgical in nature.

  3. Extreme swimming: The oceanic migrations of anguillids

    DEFF Research Database (Denmark)

    Righton, David; Aarestrup, Kim; Jellyman, Don

    2013-01-01

    to their natal habitat to spawn. In temperate species, the migrations are extreme, requiring larvae and adults to swim thousands of km before reaching their destination, but the migrations of tropical species (hundreds of km) are still remarkable in comparison with many other fish species. To achieve...

  4. Swimming Performance of Adult Asian Carp: Field Assessment Using a Mobile Swim Tunnel

    Science.gov (United States)

    2016-08-01

    left side, outflow is located on the right side. The collimator grid can be seen at right . The mobile tunnel was newly designed and constructed by...chute with the river (Varble et al. 2007). The Silver Carp contained in the chute were abundant, large, and sexually mature. Methods. The swim...robustness were < 12% (Table 4). Swimming performance is influenced by a complex suite of factors. These may be intrinsic, such as fish size, reproductive

  5. Winter temperatures decrease swimming performance and limit distributions of tropical damselfishes.

    Science.gov (United States)

    Johansen, Jacob L; Steffensen, John F; Jones, Geoffrey P

    2015-01-01

    Coral reefs within 10° of the equator generally experience ≤3°C seasonal variation in water temperature. Ectotherms that have evolved in these conditions are therefore expected to exhibit narrow thermal optima and be very sensitive to the greater thermal variability (>6°C) experienced at higher latitudes (≥10°N/S). The impact of increased thermal variability on the fitness and distribution of thermally sensitive reef ectotherms is currently unknown. Here, we examine site-attached planktivorous coral reef damselfishes that rely on their physiological capacity to swim and forage in the water column year round. We focus on 10 species spanning four evolutionarily distinct genera from a region of the Great Barrier Reef that experiences ≥6°C difference between seasons. Four ecologically important indicators showed reduced performance during the winter low (23°C) compared with the summer peak (29°C), with effect sizes varying among species and genera, as follows: (i) the energy available for activity (aerobic scope) was reduced by 35-45% in five species and three genera; (ii) the energetically most efficient swimming speed was reduced by 17% across all species; and (iii) the maximal critical swimming speed and (iv) the gait transition speed (the swimming mode predominantly used for foraging) were reduced by 16-42% in six species spanning all four genera. Comparisons with field surveys within and across latitudes showed that species-specific distributions were strongly correlated with these performance indicators. Species occupy habitats where they can swim faster than prevailing habitat currents year round, and >95% of individuals were observed only in habitats where the gait transition speed can be maintained at or above habitat currents. Thermal fluctuation at higher latitudes appears to reduce performance as well as the possible distribution of species and genera within and among coral reef habitats. Ultimately, thermal variability across latitudes may

  6. Kick, Stroke and Swim: Complement Your Swimming Program by Engaging the Whole Body on Dry Land and in the Pool

    Science.gov (United States)

    Flynn, Susan; Duell, Kelly; Dehaven, Carole; Heidorn, Brent

    2017-01-01

    The Kick, Stroke and Swim (KSS) program can be used to engage students in swimming-skill acquisition and fitness training using a variety of modalities, strategies and techniques on dry land. Practicing swim strokes and techniques on land gives all levels of swimmers--from beginner to competitive--a kinesthetic awareness of the individual…

  7. Features of technical and tactical actions of highly skilled athletes at swimming of competitive distances of 50, 100 and 200 meters way to crawl on his back

    Directory of Open Access Journals (Sweden)

    Olga Pilipko

    2014-12-01

    Full Text Available Purpose: to identify the features of technical and tactical actions of highly skilled athletes, specializing in swimming crawl on way back to the distances of different lengths. Material and Methods: we used analysis of scientific and methodical literature, teacher observation, video, timing, methods of mathematical processing of the data. Collection of digital material was carried out during the Championship and Cup of Ukraine on swimming. Surveyed group consisted of participants of the final swim at distances of 50, 100 and 200 meters way to crawl on his back. Results: characterized by changes of speed, tempo and "step" cycle paddle movements in the process of overcoming competitive distances of 50, 100 and 200 meters way to crawl on his back, given their comparative characteristics. Conclusions: the nature of the technical and tactical actions of highly skilled athletes, specializing in swimming crawl on way back, depending on the length of competitive distance.

  8. Optimal search direction for an animal flying or swimming in a wind or current.

    Science.gov (United States)

    Dusenbery, D B

    1989-11-01

    The problem of the optimal direction in which a flying or swimming animal should search for a chemical plume was addressed. Active spaces were approximated by sphere, prolate ellipsoids, or rectangular parallelepipeds of various length-to-width ratios. The optimum course direction for the sphere was in the direction of flow (downwind). For active spaces that were highly elongated along the direction of the wind or current, the optimal course heading (with respect to the moving medium) was nearly across the flow. For intermediate shapes, the optimal course was intermediate. Because of the effect of the moving medium, these course headings resulted in actual ground tracks that were more in the direction of the flow, depending on the relative speeds of flying (swimming) and the wind (current). When the two speeds were equal, the magnitude of the advantage of choosing the optimum direction over a random direction was close to 50% with a small dependence on the shape of the active space. If the active space was spherical or highly elongated or locomotor speed was much greater than the speed of the current, the advantage approached a factor of π/2 (≈ 1.57).

  9. Relationships among traits of aerobic and anaerobic swimming performance in individual European sea bass Dicentrarchus labrax.

    Directory of Open Access Journals (Sweden)

    Stefano Marras

    Full Text Available Teleost fishes exhibit wide and temporally stable inter-individual variation in a suite of aerobic and anaerobic locomotor traits. One mechanism that could allow such variation to persist within populations is the presence of tradeoffs between aerobic and anaerobic performance, such that individuals with a high capacity for one type of performance have a reduced capacity for the other. We investigated this possibility in European seabass Dicentrarchuslabrax, each measured for a battery of indicators of maximum locomotor performance. Aerobic traits comprised active metabolic rate, aerobic scope for activity, maximum aerobic swimming speed, and stride length, using a constant acceleration test. Anaerobic traits comprised maximum speed during an escape response, maximum sprint speed, and maximum anaerobic burst speed during constant acceleration. The data provided evidence of significant variation in performance among individuals, but there was no evidence of any trade-offs among any traits of aerobic versus anaerobic swimming performance. Furthermore, the anaerobic traits were not correlated significantly among each other, despite relying on the same muscular structures. Thus, the variation observed may reflect trade-offs with other morphological, physiological or behavioural traits.

  10. Setting the pace: new insights into central pattern generator interactions in box jellyfish swimming.

    Directory of Open Access Journals (Sweden)

    Anna Lisa Stöckl

    Full Text Available Central Pattern Generators (CPGs produce rhythmic behaviour across all animal phyla. Cnidarians, which have a radially symmetric nervous system and pacemaker centres in multiples of four, provide an interesting comparison to bilaterian animals for studying the coordination between CPGs. The box jellyfish Tripedalia cystophora is remarkable among cnidarians due to its most elaborate visual system. Together with their ability to actively swim and steer, they use their visual system for multiple types of behaviour. The four swim CPGs are directly regulated by visual input. In this study, we addressed the question of how the four pacemaker centres of this radial symmetric cnidarian interact. We based our investigation on high speed camera observations of the timing of swim pulses of tethered animals (Tripedalia cystophora with one or four rhopalia, under different simple light regimes. Additionally, we developed a numerical model of pacemaker interactions based on the inter pulse interval distribution of animals with one rhopalium. We showed that the model with fully resetting coupling and hyperpolarization of the pacemaker potential below baseline fitted the experimental data best. Moreover, the model of four swim pacemakers alone underscored the proportion of long inter pulse intervals (IPIs considerably. Both in terms of the long IPIs as well as the overall swim pulse distribution, the simulation of two CPGs provided a better fit than that of four. We therefore suggest additional sources of pacemaker control than just visual input. We provide guidelines for future research on the physiological linkage of the cubozoan CPGs and show the insight from bilaterian CPG research, which show that pacemakers have to be studied in their bodily and nervous environment to capture all their functional features, are also manifest in cnidarians.

  11. Setting the pace: new insights into central pattern generator interactions in box jellyfish swimming.

    Science.gov (United States)

    Stöckl, Anna Lisa; Petie, Ronald; Nilsson, Dan-Eric

    2011-01-01

    Central Pattern Generators (CPGs) produce rhythmic behaviour across all animal phyla. Cnidarians, which have a radially symmetric nervous system and pacemaker centres in multiples of four, provide an interesting comparison to bilaterian animals for studying the coordination between CPGs. The box jellyfish Tripedalia cystophora is remarkable among cnidarians due to its most elaborate visual system. Together with their ability to actively swim and steer, they use their visual system for multiple types of behaviour. The four swim CPGs are directly regulated by visual input. In this study, we addressed the question of how the four pacemaker centres of this radial symmetric cnidarian interact. We based our investigation on high speed camera observations of the timing of swim pulses of tethered animals (Tripedalia cystophora) with one or four rhopalia, under different simple light regimes. Additionally, we developed a numerical model of pacemaker interactions based on the inter pulse interval distribution of animals with one rhopalium. We showed that the model with fully resetting coupling and hyperpolarization of the pacemaker potential below baseline fitted the experimental data best. Moreover, the model of four swim pacemakers alone underscored the proportion of long inter pulse intervals (IPIs) considerably. Both in terms of the long IPIs as well as the overall swim pulse distribution, the simulation of two CPGs provided a better fit than that of four. We therefore suggest additional sources of pacemaker control than just visual input. We provide guidelines for future research on the physiological linkage of the cubozoan CPGs and show the insight from bilaterian CPG research, which show that pacemakers have to be studied in their bodily and nervous environment to capture all their functional features, are also manifest in cnidarians.

  12. Current-oriented swimming by jellyfish and its role in bloom maintenance.

    Science.gov (United States)

    Fossette, Sabrina; Gleiss, Adrian Christopher; Chalumeau, Julien; Bastian, Thomas; Armstrong, Claire Denise; Vandenabeele, Sylvie; Karpytchev, Mikhail; Hays, Graeme Clive

    2015-02-02

    Cross-flows (winds or currents) affect animal movements [1-3]. Animals can temporarily be carried off course or permanently carried away from their preferred habitat by drift depending on their own traveling speed in relation to that of the flow [1]. Animals able to only weakly fly or swim will be the most impacted (e.g., [4]). To circumvent this problem, animals must be able to detect the effects of flow on their movements and respond to it [1, 2]. Here, we show that a weakly swimming organism, the jellyfish Rhizostoma octopus, can orientate its movements with respect to currents and that this behavior is key to the maintenance of blooms and essential to reduce the probability of stranding. We combined in situ observations with first-time deployment of accelerometers on free-ranging jellyfish and simulated the behavior observed in wild jellyfish within a high-resolution hydrodynamic model. Our results show that jellyfish can actively swim countercurrent in response to current drift, leading to significant life-history benefits, i.e., increased chance of survival and facilitated bloom formation. Current-oriented swimming may be achieved by jellyfish either directly detecting current shear across their body surface [5] or indirectly assessing drift direction using other cues (e.g., magnetic, infrasound). Our coupled behavioral-hydrodynamic model provides new evidence that current-oriented swimming contributes to jellyfish being able to form aggregations of hundreds to millions of individuals for up to several months, which may have substantial ecosystem and socioeconomic consequences [6, 7]. It also contributes to improve predictions of jellyfish blooms' magnitude and movements in coastal waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A New Method to Calibrate Attachment Angles of Data Loggers in Swimming Sharks

    Science.gov (United States)

    Kawatsu, Shizuka; Sato, Katsufumi; Watanabe, Yuuki; Hyodo, Susumu; Breves, Jason P.; Fox, Bradley K.; Grau, E. Gordon; Miyazaki, Nobuyuki

    2009-12-01

    Recently, animal-borne accelerometers have been used to record the pitch angle of aquatic animals during swimming. When evaluating pitch angle, it is necessary to consider a discrepancy between the angle of an accelerometer and the long axis of an animal. In this study, we attached accelerometers to 17 free-ranging scalloped hammerhead shark ( Sphyrna lewini) pups from Kaneohe Bay, Hawaii. Although there are methods to calibrate attachment angles of accelerometers, we confirmed that previous methods were not applicable for hammerhead pups. According to raw data, some sharks ascended with a negative angle, which differs from tank observations of captive sharks. In turn, we developed a new method to account for this discrepancy in swimming sharks by estimating the attachment angle from the relationship between vertical speed (m/s) and pitch angle obtained by each accelerometer. The new method can be utilized for field observation of a wide range of species.

  14. Coordination and propulsion and non-propulsion phases in 100 meter breaststroke swimming.

    Science.gov (United States)

    Strzała, Marek; Krężałek, Piotr; Kucia-Czyszczoń, Katarzyna; Ostrowski, Andrzej; Stanula, Arkadiusz; Tyka, Anna K; Sagalara, Andrzej

    2014-01-01

    The main purpose of this study was to analyze the coordination, propulsion and non-propulsion phases in the 100 meter breaststroke race. Twenty-seven male swimmers (15.7 ± 1.98 years old) with the total body length (TBL) of 247.0 ± 10.60 [cm] performed an all-out 100 m breaststroke bout. The bouts were recorded with an underwater camera installed on a portable trolley. The swimming kinematic parameters, stroke rate (SR) and stroke length (SL), as well as the coordination indices based on propulsive or non-propulsive movement phases of the arms and legs were distinguished. Swimming speed (V100surface breast) was associated with SL (R = 0.41, p importance of proper execution of this phase (AP3) and in reducing the resistance recovery phases in consecutive ones.

  15. A New Method to Calibrate Attachment Angles of Data Loggers in Swimming Sharks

    Directory of Open Access Journals (Sweden)

    Shizuka Kawatsu

    2010-01-01

    Full Text Available Recently, animal-borne accelerometers have been used to record the pitch angle of aquatic animals during swimming. When evaluating pitch angle, it is necessary to consider a discrepancy between the angle of an accelerometer and the long axis of an animal. In this study, we attached accelerometers to 17 free-ranging scalloped hammerhead shark (Sphyrna lewini pups from Kaneohe Bay, Hawaii. Although there are methods to calibrate attachment angles of accelerometers, we confirmed that previous methods were not applicable for hammerhead pups. According to raw data, some sharks ascended with a negative angle, which differs from tank observations of captive sharks. In turn, we developed a new method to account for this discrepancy in swimming sharks by estimating the attachment angle from the relationship between vertical speed (m/s and pitch angle obtained by each accelerometer. The new method can be utilized for field observation of a wide range of species.

  16. Fast, automated measurement of nematode swimming (thrashing without morphometry

    Directory of Open Access Journals (Sweden)

    Sattelle David B

    2009-07-01

    less than 30 s and can therefore be deployed in rapid screens. Conclusion We demonstrate that a covariance-based method yields a fast, reliable, automated measurement of C. elegans motility which can replace the far more time-consuming, manual method. The absence of a morphometry step means that the method can be applied to any nematode that swims in liquid and, together with its speed, this simplicity lends itself to deployment in large-scale chemical and genetic screens.

  17. Octopus-inspired multi-arm robotic swimming.

    Science.gov (United States)

    Sfakiotakis, M; Kazakidi, A; Tsakiris, D P

    2015-05-13

    The outstanding locomotor and manipulation characteristics of the octopus have recently inspired the development, by our group, of multi-functional robotic swimmers, featuring both manipulation and locomotion capabilities, which could be of significant engineering interest in underwater applications. During its little-studied arm-swimming behavior, as opposed to the better known jetting via the siphon, the animal appears to generate considerable propulsive thrust and rapid acceleration, predominantly employing movements of its arms. In this work, we capture the fundamental characteristics of the corresponding complex pattern of arm motion by a sculling profile, involving a fast power stroke and a slow recovery stroke. We investigate the propulsive capabilities of a multi-arm robotic system under various swimming gaits, namely patterns of arm coordination, which achieve the generation of forward, as well as backward, propulsion and turning. A lumped-element model of the robotic swimmer, which considers arm compliance and the interaction with the aquatic environment, was used to study the characteristics of these gaits, the effect of various kinematic parameters on propulsion, and the generation of complex trajectories. This investigation focuses on relatively high-stiffness arms. Experiments employing a compliant-body robotic prototype swimmer with eight compliant arms, all made of polyurethane, inside a water tank, successfully demonstrated this novel mode of underwater propulsion. Speeds of up to 0.26 body lengths per second (approximately 100 mm s(-1)), and propulsive forces of up to 3.5 N were achieved, with a non-dimensional cost of transport of 1.42 with all eight arms and of 0.9 with only two active arms. The experiments confirmed the computational results and verified the multi-arm maneuverability and simultaneous object grasping capability of such systems.

  18. Flagellar swimming in viscoelastic fluids: role of fluid elastic stress revealed by simulations based on experimental data.

    Science.gov (United States)

    Li, Chuanbin; Qin, Boyang; Gopinath, Arvind; Arratia, Paulo E; Thomases, Becca; Guy, Robert D

    2017-10-01

    Many important biological functions depend on microorganisms' ability to move in viscoelastic fluids such as mucus and wet soil. The effects of fluid elasticity on motility remain poorly understood, partly because the swimmer strokes depend on the properties of the fluid medium, which obfuscates the mechanisms responsible for observed behavioural changes. In this study, we use experimental data on the gaits of Chlamydomonas reinhardtii swimming in Newtonian and viscoelastic fluids as inputs to numerical simulations that decouple the swimmer gait and fluid type in order to isolate the effect of fluid elasticity on swimming. In viscoelastic fluids, cells employing the Newtonian gait swim faster but generate larger stresses and use more power, and as a result the viscoelastic gait is more efficient. Furthermore, we show that fundamental principles of swimming based on viscous fluid theory miss important flow dynamics: fluid elasticity provides an elastic memory effect that increases both the forward and backward speeds, and (unlike purely viscous fluids) larger fluid stress accumulates around flagella moving tangent to the swimming direction, compared with the normal direction. © 2017 The Author(s).

  19. Numerical investigation of the hydrodynamics of carangiform swimming in the transitional and inertial flow regimes.

    Science.gov (United States)

    Borazjani, Iman; Sotiropoulos, Fotis

    2008-05-01

    We employ numerical simulation to investigate the hydrodynamics of carangiform locomotion as the relative magnitude of viscous and inertial forces, i.e. the Reynolds number (Re), and the tail-beat frequency, i.e. the Strouhal number (St), are systematically varied. The model fish is a three-dimensional (3D) mackerel-like flexible body undulating with prescribed experimental kinematics of carangiform type. Simulations are carried out for three Re spanning the transitional and inertial flow regimes, Re=300 and 4000 (viscous flow), and infinity (inviscid flow). For each Re there is a critical Strouhal number, St*, at which the net mean force becomes zero, making constant-speed self-propulsion possible. St* is a decreasing function of Re and approaches the range of St at which most carangiform swimmers swim in nature (St approximately 0.25) only as Re approaches infinity. The propulsive efficiency at St* is an increasing function of Re while the power required for swimming is decreasing with Re. For all Re, however, the swimming power is shown to be significantly greater than that required to tow the rigid body at the same speed. We also show that the variation of the total drag and its viscous and form components with St depend on the Re. For Re=300, body undulations increase the drag over the rigid body level, while significant drag reduction is observed for Re=4000. This difference is shown to be due to the fact that at sufficiently high Re the drag force variation with St is dominated by its form component variation, which is reduced by undulatory swimming for St>0.2. Finally, our simulations clarify the 3D structure of various wake patterns observed in experiments--single and double row vortices--and suggest that the wake structure depends primarily on the St. Our numerical findings help elucidate the results of previous experiments with live fish, underscore the importance of scale (Re) effects on the hydrodynamic performance of carangiform swimming, and help

  20. Analysis of swimming performance in FINA World Cup long-distance open water races.

    Science.gov (United States)

    Zingg, Matthias Alexander; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald; Knechtle, Beat

    2014-01-02

    Age and peak performance in ultra-endurance athletes have been mainly investigated in long-distance runners and triathletes, but not for long-distance swimmers. The present study investigated the age and swimming performance of elite ultra-distance swimmers competing in the 5-, 10- and 25-km Fédération Internationale de Natation (FINA) World Cup swimming events. The associations of age and swimming speed in elite male and female swimmers competing in World Cup events of 5-, 10- and 25-km events from 2000 to 2012 were analysed using single and multi-level regression analyses. During the studied period, the swimming speed of the annual top ten women decreased significantly from 4.94 ± 0.20 to 4.77 ± 0.09 km/h in 5 km and from 4.60 ± 0.04 to 4.44 ± 0.08 km/h in 25 km, while it significantly increased from 4.57 ± 0.01 to 5.75 ± 0.01 km/h in 10 km. For the annual top ten men, peak swimming speed decreased significantly from 5.42 ± 0.04 to 5.39 ± 0.02 km/h in 5 km, while it remained unchanged at 5.03 ± 0.32 km/h in 10 km and at 4.94 ± 0.35 km/h in 25 km. The age of peak swimming speed for the annual top ten women remained stable at 22.5 ± 1.2 years in 5 km, at 23.4 ± 0.9 years in 10 km and at 23.8 ± 0.9 years in 25 km. For the annual top ten men, the age of peak swimming speed increased from 23.7 ± 2.8 to 28.0 ± 5.1 years in 10 km but remained stable at 24.8 ± 1.0 years in 5 km and at 27.2 ± 1.1 years in 25 km. Female long-distance swimmers competing in FINA World Cup races between 2000 and 2012 improved in 10 km but impaired in 5 and 25 km, whereas men only impaired in 5 km. The age of peak performance was younger in women (approximately 23 years) compared to men (about 25-27 years).

  1. ANALYSIS OF RELATIONSHIPS BETWEEN THE LEVEL OF ERRORS IN LEG AND MONOFIN MOVEMENT AND STROKE PARAMETERS IN MONOFIN SWIMMING

    Directory of Open Access Journals (Sweden)

    Marek Rejman

    2013-03-01

    Full Text Available The aim of this study was to analyze the error structure in propulsive movements with regard to its influence on monofin swimming speed. The random cycles performed by six swimmers were filmed during a progressive test (900m. An objective method to estimate errors committed in the area of angular displacement of the feet and monofin segments was employed. The parameters were compared with a previously described model. Mutual dependences between the level of errors, stroke frequency, stroke length and amplitude in relation to swimming velocity were analyzed. The results showed that proper foot movements and the avoidance of errors, arising at the distal part of the fin, ensure the progression of swimming speed. The individual stroke parameters distribution which consists of optimally increasing stroke frequency to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors. Identification of key elements in the stroke structure based on the analysis of errors committed should aid in improving monofin swimming technique

  2. Swimming Dynamics of the Lyme Disease Spirochete

    Science.gov (United States)

    Vig, Dhruv K.; Wolgemuth, Charles W.

    2012-11-01

    The Lyme disease spirochete, Borrelia burgdorferi, swims by undulating its cell body in the form of a traveling flat wave, a process driven by rotating internal flagella. We study B. burgdorferi’s swimming by treating the cell body and flagella as linearly elastic filaments. The dynamics of the cell are then determined from the balance between elastic and resistive forces and moments. We find that planar, traveling waves only exist when the flagella are effectively anchored at both ends of the bacterium and that these traveling flat waves rotate as they undulate. The model predicts how the undulation frequency is related to the torque from the flagellar motors and how the stiffness of the cell body and flagella affect the undulations and morphology.

  3. Biomechanics of competitive front crawl swimming.

    Science.gov (United States)

    Toussaint, H M; Beek, P J

    1992-01-01

    Essential performance-determining factors in front crawl swimming can be analysed within a biomechanical framework, in reference to the physiological basis of performance. These factors include: active drag forces, effective propulsive forces, propelling efficiency and power output. The success of a swimmer is determined by the ability to generate propulsive force, while reducing the resistance to forward motion. Although for a given competitive stroke a range of optimal stroking styles may be expected across a sample of swimmers, a common element of technique related to a high performance level is the use of complex sculling motions of the hands to generate especially lift forces. By changing the orientation of the hand the propulsive force acting on the hand is aimed successfully in the direction of motion. Furthermore, the swimming velocity (v) is related to drag (A), power input (Pi, the rate of energy liberation via the aerobic/anaerobic metabolism), the gross efficiency (eg), propelling efficiency (ep), and power output (Po) according to: [formula; see text] Based on the research available at present it is concluded that: (a) drag in groups of elite swimmers homogeneous with respect to swimming technique is determined by anthropometric dimensions; (b) total mechanical power output (Po) is important since improvement in performance is related to increased Po. Furthermore, it shows dramatic changes with training and possibly reflects the size of the 'swimming engine'; (c) propelling efficiency seems to be important since it is much higher in elite swimmers (61%) than in triathletes (44%); and (d) distance per stroke gives a fairly good indication of propelling efficiency and may be used to evaluate individual progress in technical ability.

  4. Quality Versus Quantity Debate in Swimming: Perceptions and Training Practices of Expert Swimming Coaches

    Directory of Open Access Journals (Sweden)

    Nugent Frank J.

    2017-06-01

    Full Text Available The debate over low-volume, high-intensity training versus high-volume, low-intensity training, commonly known as Quality versus Quantity, respectively, is a frequent topic of discussion among swimming coaches and academics. The aim of this study was to explore expert coaches’ perceptions of quality and quantity coaching philosophies in competitive swimming and to investigate their current training practices. A purposeful sample of 11 expert swimming coaches was recruited for this study. The study was a mixed methods design and involved each coach participating in 1 semi-structured interview and completing 1 closed-ended questionnaire. The main findings of this study were that coaches felt quality training programmes would lead to short term results for youth swimmers, but were in many cases more appropriate for senior swimmers. The coaches suggested that quantity training programmes built an aerobic base for youth swimmers, promoted technical development through a focus on slower swimming and helped to enhance recovery from training or competition. However, the coaches continuously suggested that quantity training programmes must be performed with good technique and they felt this was a misunderstood element. This study was a critical step towards gaining a richer and broader understanding on the debate over Quality versus Quantity training from an expert swimming coaches’ perspective which was not currently available in the research literature.

  5. Quality versus Quantity Debate in Swimming: Perceptions and Training Practices of Expert Swimming Coaches.

    Science.gov (United States)

    Nugent, Frank J; Comyns, Thomas M; Warrington, Giles D

    2017-06-01

    The debate over low-volume, high-intensity training versus high-volume, low-intensity training, commonly known as Quality versus Quantity, respectively, is a frequent topic of discussion among swimming coaches and academics. The aim of this study was to explore expert coaches' perceptions of quality and quantity coaching philosophies in competitive swimming and to investigate their current training practices. A purposeful sample of 11 expert swimming coaches was recruited for this study. The study was a mixed methods design and involved each coach participating in 1 semi-structured interview and completing 1 closed-ended questionnaire. The main findings of this study were that coaches felt quality training programmes would lead to short term results for youth swimmers, but were in many cases more appropriate for senior swimmers. The coaches suggested that quantity training programmes built an aerobic base for youth swimmers, promoted technical development through a focus on slower swimming and helped to enhance recovery from training or competition. However, the coaches continuously suggested that quantity training programmes must be performed with good technique and they felt this was a misunderstood element. This study was a critical step towards gaining a richer and broader understanding on the debate over Quality versus Quantity training from an expert swimming coaches' perspective which was not currently available in the research literature.

  6. Controlled-frequency breath swimming improves swimming performance and running economy.

    Science.gov (United States)

    Lavin, K M; Guenette, J A; Smoliga, J M; Zavorsky, G S

    2015-02-01

    Respiratory muscle fatigue can negatively impact athletic performance, but swimming has beneficial effects on the respiratory system and may reduce susceptibility to fatigue. Limiting breath frequency during swimming further stresses the respiratory system through hypercapnia and mechanical loading and may lead to appreciable improvements in respiratory muscle strength. This study assessed the effects of controlled-frequency breath (CFB) swimming on pulmonary function. Eighteen subjects (10 men), average (standard deviation) age 25 (6) years, body mass index 24.4 (3.7) kg/m(2), underwent baseline testing to assess pulmonary function, running economy, aerobic capacity, and swimming performance. Subjects were then randomized to either CFB or stroke-matched (SM) condition. Subjects completed 12 training sessions, in which CFB subjects took two breaths per length and SM subjects took seven. Post-training, maximum expiratory pressure improved by 11% (15) for all 18 subjects (P swimming may improve muscular oxygen utilization during terrestrial exercise in novice swimmers. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Volumetric flow around a swimming lamprey

    Science.gov (United States)

    Lehn, Andrea M.; Colin, Sean P.; Costello, John H.; Leftwich, Megan C.; Tytell, Eric D.

    2015-11-01

    A primary experimental technique for studying fluid-structure interactions around swimming fish has been planar dimensional particle image velocimetry (PIV). Typically, two components of the velocity vector are measured in a plane, in the case of swimming studies, directly behind the animal. While useful, this approach provides little to no insight about fluid structure interactions above and below the fish. For fish with a small height relative to body length, such as the long and approximately cylindrical lamprey, 3D information is essential to characterize how these fish interact with their fluid environment. This study presents 3D flow structures along the body and in the wake of larval lamprey, P etromyzon m arinus , which are 10-15 cm long. Lamprey swim through a 1000 cm3 field of view in a standard 10 gallon tank illuminated by a green laser. Data are collected using the three component velocimeter V3V system by TSI, Inc. and processed using Insight 4G software. This study expands on previous works that show two pairs of vortices each tail beat in the mid-plane of the lamprey wake. NSF DMS 1062052.

  8. [Effects of starvation on the consumption of energy sources and swimming performance in juvenile Gambusia affinis and Tanichthys albonubes].

    Science.gov (United States)

    Li, Jiang-tao; Lin, Xiao-tao; Zhou, Chen-hui; Zeng, Peng; Xu, Zhong-neng; Sun, Jun

    2016-01-01

    To explore the consumption of energy sources and swimming performance of juvenile Gambusia affinis and Tanichthys albonubes after starvation, contents of glycogen, lipid and protein, burst swimming speeds (Uburst), and critical swimming speeds (Ucrit) at different starvation times (0, 10, 20, 30 and 40 days) were evaluated. The results showed that, at 0 day, contents of glycogen and lipid were significantly lower in G. affinis than those in T. albonubes, whereas no significant difference in content of protein between two experimental fish was found. Swimming speeds in G. affinis were significantly lower than those in T. albonubes for all swimming performances. After different starvation scenarios, content of glycogen both in G. affinis and T. albonubes decreased significantly in power function trend with starvation time and were close to zero after starvation for 10 days, whereas the contents of lipid and protein were linearly significantly decreased. The slope of line regression equation between content of lipid and starvation time in G. affinis was significantly lower than that in T. albonubes, whereas there was a significantly higher slope of line equation between content of protein and starvation time in G. affinis. 40 days later, the consumption rate of glycogen both in G. affinis and T. albonubes were significantly higher than that of lipid, while the consumption rate of protein was the least. Consumption amounts of glycogen in all experimental fish were the least, G. affinis consumed more protein than lipid, and T. albonubes consumed more lipid than protein. Uburst and Ucrit decreased significantly linearly with starvation time for all experimental fish. Slope of linear equation between Uburst and starvation time was not significantly different between G. affinis and T. albonubes. However, the straight slope between Ucrit and starvation time was significantly lower in G. affinis than that in T. albonubes. These findings indicated that there was close

  9. Speeding Up Innovation

    DEFF Research Database (Denmark)

    Sørensen, Flemming; Mattsson, Jan

    2016-01-01

    . Much innovation today takes place in open structures in which networks play an important role. However, little is known about how innovation networks can facilitate parallel innovation processes. This paper discusses how innovation network structures develop and support exploration and exploitation......Minimisation of time-to-market strategies can provide companies with a competitive advantage in dynamic and competitive environments. Using parallel innovation processes has been emphasised as one strategy to speed up innovation processes and consequently minimise the time-to-market of innovations...... in parallel innovation processes and in this way sustain speedy innovation processes. A case study of an innovation network is carried out by analysing communication structures and the information contents of emails related to a particular innovation process. The analysis shows how certain characteristics...

  10. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming

    Science.gov (United States)

    Choi, Kevin

    2015-01-01

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg−1·min−1 and boost glucose disposal to 40.1 ± 13 μmol·kg−1·min−1. These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. PMID:26719305

  11. Widespread utilization of passive energy recapture in swimming medusae.

    Science.gov (United States)

    Gemmell, Brad J; Colin, Sean P; Costello, John H

    2018-01-11

    Recently, it has been shown that some medusae are capable of swimming very efficiently, i.e. with a low cost of transport, and that this is in part due to passive energy recapture (PER) which occurs during bell relaxation. We compared the swimming kinematics among a diverse array of medusae, varying in taxonomy, morphology and propulsive and foraging modes, in order to evaluate the prevalence of PER in medusae. We found that while PER was common among taxa, the magnitude of the contribution to overall swimming varied greatly. The ability of medusae to utilize PER was not related to morphology and swimming performance but was controlled by their swimming kinematics. Utilizing PER required the medusae to pause after bell expansion and individuals could modulate their PER by changing their pause duration. PER can greatly enhance swimming efficiency but there appear to be trade-offs associated with utilizing PER. © 2018. Published by The Company of Biologists Ltd.

  12. SWIMMING CLASSES IN JUNIOR HIGH SCHOOL STUDENTS’ OPINION

    Directory of Open Access Journals (Sweden)

    Grzegorz Bielec

    2013-02-01

    Full Text Available The role of modern physical education is not only to develop motor abilities of the students, but most of all prevent them from epidemic youth diseases such as obesity or postural defects. Positive attitudes to swimming as a long-life physical activity, instilled in adolescence should be beneficial in adult life. The group of 130 boys and 116 girls of 7th grade junior high school (mean age 14.6 was asked in the survey to present their opinion of obligatory swimming lessons at school. Students of both sexes claimed that they liked swimming classes because they could improve their swimming skills (59% of answers and because of health-related character of water exercises (38%. 33% of students regarded swimming lessons as boring and monotonous, and 25% of them complained about poor pool conditions like chlorine smell, crowded lanes, too low temperature. Majority of the surveyed students saw practical role of swimming in saving others life.

  13. The fluid dynamics of swimming by jumping in copepods

    DEFF Research Database (Denmark)

    Jiang, Houshuo; Kiørboe, Thomas

    2011-01-01

    Copepods swim either continuously by vibrating their feeding appendages or erratically by repeatedly beating their swimming legs resulting in a series of small jumps. The two swimming modes generate different hydrodynamic disturbances and therefore expose the swimmers differently to rheotactic...... limited and temporally ephemeral owing to jump-impulsiveness and viscous decay. In contrast, continuous steady swimming generates two well-extended long-lasting momentum jets both in front of and behind the swimmer, as suggested by the well-known steady stresslet model. Based on the observed jump-swimming...... kinematics of a small copepod Oithona davisae, we further showed that jump-swimming produces a hydrodynamic disturbance with much smaller spatial extension and shorter temporal duration than that produced by a same-size copepod cruising steadily at the same average translating velocity. Hence, small copepods...

  14. Laryngoscopy during swimming: A novel diagnostic technique to characterize swimming-induced laryngeal obstruction.

    Science.gov (United States)

    Walsted, Emil S; Swanton, Laura L; van van Someren, Ken; Morris, Tessa E; Furber, Matthew; Backer, Vibeke; Hull, James H

    2017-10-01

    Exercise-induced laryngeal obstruction (EILO) is a key differential diagnosis for respiratory symptoms in athletes and is particularly prevalent in aquatic athletes. A definitive diagnosis of EILO is dependent on laryngoscopy, performed continuously, while an athlete engages in the sport that precipitates their symptoms. This report provides the first description of the feasibility of performing continuous laryngoscopy during exercise in a swimming environment. The report describes the methodology and safety of the use of continuous laryngoscopy while swimming. Laryngoscope, 127:2298-2301, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  15. The Physiology and Mechanics of Undulatory Swimming: A Student Laboratory Exercise Using Medicinal Leeches

    Science.gov (United States)

    Ellerby, David J.

    2009-01-01

    The medicinal leech is a useful animal model for investigating undulatory swimming in the classroom. Unlike many swimming organisms, its swimming performance can be quantified without specialized equipment. A large blood meal alters swimming behavior in a way that can be used to generate a discussion of the hydrodynamics of swimming, muscle…

  16. Two dimensional immersed boundary simulations of swimming jellyfish

    OpenAIRE

    Fang, Haowen

    2013-01-01

    The swimming behavior of jellyfish, driven by the periodic contraction of body muscles,can be modeled using a two dimensional bell-shaped membrane immersed in fluid with aperiodic contraction force exerted along the membrane. We aim to use a simple two dimensional elastic membrane to simulate the swimming behavior without imposing any given membrane configuration, in which the swimming behavior is driven naturally by the interaction between the elastic membrane and fluid and solved by the imm...

  17. Motivation of women to cultivate thein self rescue swimming skills

    OpenAIRE

    Stralczynská, Anna

    2012-01-01

    Work name: Motivation of women to cultivate thein self rescue swimming skills. Aim of work: Defining a set of basic self rescue swimming skills, motivation survey of women aged 18-60 years to cultivate these skills. Detection of awareness of theimportance of swimming skills of the interviewed women. Method: Literature search, questionnaire design, survey implementation, analysis and evaluation of data, graphical presentation of results. Results: The interviewed women realize the importance an...

  18. The swimming literacy of women in term sof self rescue

    OpenAIRE

    Vokurková, Eva

    2012-01-01

    Work name: The swimming literacy of women in term of self rescue Aim of work: To acquire and analyze data about the level of the swimming literacy and self rescue skills of women aged 18 - 72 years, whether they can handle and use them. Method: Literature search, creation of the questionnaire, implementation survey, data analysis and graphical presentation of results. Results: The analysis of the swimming literacy and self rescue skills of women. Key words: literacy, physical literacy, swimmi...

  19. Dehumidification by heat pump in indoor swimming pools

    Energy Technology Data Exchange (ETDEWEB)

    Eymery, J.C. (Electricite de France, 75 - Paris)

    1982-10-01

    The values of the quantity of water evaporated in an indoor swimming pool are determined and technical alternatives for dehumidification are discussed; standard process by air replacement; new process by heat pump, with recovery of the latent heat of the moist air in the swimming pool hall. The author offers an example of the dimensioning of the heat pump and gives energy balances (fuel and electricity comsumption) of existing swimming pools equipped subsequently.

  20. Specifics of swimming teaching children with autism spectrum disorder.

    OpenAIRE

    Baštová, Miroslava

    2015-01-01

    Title: Specifics of swimming teaching children with autism spectrum disorder. Objectives: Application of the structured learning by the concept of common preparatory and basic swimming lessons for children with autism spectrum disorder. Presentation and evaluation of nine case studies and subsequent implementation of policy for teaching swimming to children with autism spectrum disorder. Methods: Analysis of specialized literature, case studies, surveys, interviews, scaling observation and st...

  1. Impacts of Deepwater Horizon crude oil exposure on adult mahi-mahi (Coryphaena hippurus) swim performance.

    Science.gov (United States)

    Stieglitz, John D; Mager, Edward M; Hoenig, Ronald H; Benetti, Daniel D; Grosell, Martin

    2016-10-01

    The temporal and geographic attributes of the Deepwater Horizon incident in 2010 likely exposed pelagic game fish species, such as mahi-mahi, to crude oil. Although much of the research assessing the effects of the spill has focused on early life stages of fish, studies examining whole-animal physiological responses of adult marine fish species are lacking. Using swim chamber respirometry, the present study demonstrates that acute exposure to a sublethal concentration of the water accommodated fraction of Deepwater Horizon crude oil results in significant swim performance impacts on young adult mahi-mahi, representing the first report of acute sublethal toxicity on adult pelagic fish in the Gulf of Mexico following the spill. At an exposure concentration of 8.4 ± 0.6 µg L(-1) sum of 50 selected polycyclic aromatic hydrocarbons (PAHs; mean of geometric means ± standard error of the mean), significant decreases in the critical and optimal swimming speeds of 14% and 10%, respectively (p crude oil exposure concentrations and a commercially and ecologically valuable Gulf of Mexico fish species, the present results provide insight into the effects of the Deepwater Horizon oil spill on adult pelagic fish. Environ Toxicol Chem 2016;35:2613-2622. © 2016 SETAC. © 2016 SETAC.

  2. Influence of pacing manipulation on performance of juniors in simulated 400-m swim competition.

    Science.gov (United States)

    Skorski, Sabrina; Faude, Oliver; Abbiss, Chris R; Caviezel, Seraina; Wengert, Nina; Meyer, Tim

    2014-09-01

    To date, there has been limited research examining the influence of pacing pattern (PP) on middle-distance swimming performance. As such, the purpose of the current study was to examine the influence of PP manipulation on 400-m freestyle swimming performance. 15 front-crawl swimmers (5 female, 10 male; age 18 ± 2 y) performed 3 simulated 400-m swimming events. The initial trial was self-selected pacing (PPSS). The following 2 trials were performed in a counterbalanced order and required participants to complete the first 100 m more slowly (PPSLOW: 4.5% ± 2.2%) or quickly (PPFAST: 2.4% ± 1.6%) than the PPSS trial. 50-m split times were recorded during each trial. Overall performance time was faster in PPSS (275.0 ± 15.9 s) than in PPFAST (278.5 ± 16.4 s, P = .05) but not significantly different from PPSLOW (277.5 ± 16.2 s, P = .22). However, analysis for practical relevance revealed that pacing manipulation resulted in a "likely" (>88.2%) decrease in performance compared with PPSS. Moderate manipulation of the starting speed during simulated 400-m freestyle races seems to affect overall performance. The observed results indicate that PPSS is optimal in most individuals, yet it seems to fail in some swimmers. Future research should focus on the identification of athletes possibly profiting from manipulations.

  3. Mechanics of swimming of multi-body bacterial swarmers using non-labeled cell tracking algorithm

    Science.gov (United States)

    Phuyal, Kiran; Kim, Min Jun

    2013-01-01

    To better understand the survival strategy of bacterial swarmers and the mechanical advantages offered by the linear chain (head-tail) attachment of the multiple bacterial bodies in an individual swarmer cell at low Reynolds number, a non-labeled cell tracking algorithm was used to quantify the mechanics of multi-body flagellated bacteria, Serratia marcescens, swimming in a motility buffer that originally exhibited the swarming motility. Swarming is a type of bacterial motility that is characterized by the collective coordinated motion of differentiated swarmer cells on a two-dimensional surface such as agar. In this study, the bacterial swarmers with multiple cell bodies (2, 3, and 4) were extracted from the swarm plate, and then tracked individually after resuspending in the motility medium. Their motion was investigated and compared with individual undifferentiated swimming bacterial cells. The swarmers when released into the motility buffer swam actively without tumbles. Their speeds, orientations, and the diffusive properties were studied by tracking the individual cell trajectories over a short distance in two-dimensional field when the cells are swimming at a constant depth in a bulk aqueous environment. At short time scales, the ballistic trajectory was dominant for both multi-body swarmers and undifferentiated cells.

  4. Modelling and Fuzzy Control of an Efficient Swimming Ionic Polymer-Metal Composite Actuated Robot

    Directory of Open Access Journals (Sweden)

    Qi Shen

    2013-10-01

    Full Text Available In this study, analytical techniques and fuzzy logic methods are applied to the dynamic modelling and efficient swimming control of a biomimetic robotic fish, which is actuated by an ionic polymer-metal composite (IPMC. A physical-based model for the biomimetic robotic fish is proposed. The model incorporates both the hydrodynamics of the IPMC tail and the actuation dynamics of the IPMC. The comparison of the results of the simulations and experiments shows the feasibility of the dynamic model. By using this model, we found that the harmonic control of the actuation frequency and voltage amplitude of the IPMC is a principal mechanism through which the robotic fish can obtain high thrust efficiency while swimming. The fuzzy control method, which is based on the knowledge of the IPMC fish's dynamic behaviour, successfully utilized this principal mechanism. By comparing the thrust performance of the robotic fish with other control methods via simulation, we established that the fuzzy controller was able to achieve faster acceleration compared with what could be achieved with a conventional PID controller. The thrust efficiency during a steady state was superior to that with conventional control methods. We also found that when using the fuzzy control method the robotic fish can always swim near a higher actuation frequency, which could obtain both the desired speed and high thrust efficiency.

  5. Inhibition of P-glycoprotein in the blood-brain barrier alters avermectin neurotoxicity and swimming performance in rainbow trout.

    Science.gov (United States)

    Kennedy, Christopher J; Tierney, Keith B; Mittelstadt, Matthew

    2014-01-01

    The importance of the blood brain barrier (BBB) and the contribution to its function by the efflux transporter P-glycoprotein (P-gp) in teleosts were examined using the P-gp substrates and central nervous system neurotoxins ivermectin (22,23-dihydroavermectin B1a+22,23-dihydroavermectin B1b) [IVM]) and emamectin benzoate (4″-deoxy-49″epimethylaminoavermectin B1 benzoate [EB]). Trout were injected intraperitoneally with 0.01-1.0 and 1-50mg/kg of IVM or EB, respectively either alone or in combination with cyclosporin A (CsA: a P-gp substrate) at 1mg/kg. IVM affected the swimming performance (critical swimming speed, burst swimming distance, and schooling) at significantly lower concentrations than EB. When fish were exposed to IVM or EB in the presence of CsA, alterations to swimming were increased, suggesting that competition for P-gp in the BBB by CsA increased IVM and EB penetration into the CNS and decreased swimming capabilities. The effect of co-administration of CsA on swimming-related toxicity was different between IVM and EB-treated fish; EB toxicity was increased to a greater extent than IVM toxicity. The greater chemosensitization effect of EB vs. IVM was examined using a P-gp competitive inhibition assay in isolated trout hepatocytes with rhodamine 123 as a substrate. At the cellular level, IVM was a more potent inhibitor of P-gp than EB, which allowed for a greater accumulation of R123 in hepatocytes. These results provide evidence for a role of P-gp in the BBB of fish, and suggest that this protein protects fish from environmental neurotoxins. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture.

    Science.gov (United States)

    Trivedi, Chintan A; Bollmann, Johann H

    2013-01-01

    Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach, and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed toward the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  7. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture

    Directory of Open Access Journals (Sweden)

    Chintan A Trivedi

    2013-05-01

    Full Text Available Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed towards the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim-triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  8. Association between infant swimming and rhinovirus-induced wheezing.

    Science.gov (United States)

    Schuez-Havupalo, Linnea; Karppinen, Sinikka; Toivonen, Laura; Kaljonen, Anne; Jartti, Tuomas; Waris, Matti; Peltola, Ville

    2014-11-01

    Infant swimming has been considered as a risk factor for wheezing, but the role that respiratory viruses play is unclear. We explored the effects of infant swimming on the risk of all wheezing illnesses and wheezing associated with rhinoviruses. We followed up a birth cohort of 1827 children until 17 months of age, collecting data on infant swimming, other risk factors and physician-diagnosed bronchiolitis or recurrent wheezing. Viral diagnostics were performed in a subset of children with all respiratory tract infections. Data on infant swimming were obtained for 1038 children, with viral follow-up for 635 children. At least one wheezing illness was documented in 45/469 (9.6%) swimming children versus 39/569 (6.9%) nonswimming children (p = 0.11), and rhinoviruses were associated with wheezing in 11/296 (3.7%) swimming children versus 4/339 (1.2%) nonswimming children (p = 0.04). In adjusted logistic regression analyses, swimming had an odds ratio of 1.71 (p = 0.05) for bronchiolitis and 3.57 (p = 0.06) for rhinovirus-associated wheezing. An association between infant swimming and rhinovirus-associated wheezing was detected for children with atopic eczema (p = 0.006). There may be a link between infant swimming and rhinovirus-induced wheezing illnesses in atopic infants. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  9. Creatine supplementation and swim performance: a brief review.

    Science.gov (United States)

    Hopwood, Melissa J; Graham, Kenneth; Rooney, Kieron B

    2006-03-01

    Nutritional supplements are popular among athletes participating in a wide variety of sports. Creatine is one of the most commonly used dietary supplements, as it has been shown to be beneficial in improving performance during repeated bouts of high-intensity anaerobic activity. This review examines the specific effects of creatine supplementation on swimming performance, and considers the effects of creatine supplementation on various measures of power development in this population. Research performed on the effect of creatine supplementation on swimming performance indicates that whilst creatine supplementation is ineffective in improving performance during a single sprint swim, dietary creatine supplementation may benefit repeated interval swim set performance. Considering the relationship between sprint swimming performance and measurements of power, the effect of creatine supplementation on power development in swimmers has also been examined. When measured on a swim bench ergometer, power development does show some improvement following a creatine supplementation regime. How this improvement in power output transfers to performance in the pool is uncertain. Although some evidence exists to suggest a gender effect on the performance improvements seen in swimmers following creatine supplementation, the majority of research indicates that male and female swimmers respond equally to supplementation. A major limitation to previous research is the lack of consideration given to the possible stroke dependant effect of creatine supplementation on swimming performance. The majority of the research conducted to date has involved examination of the freestyle swimming stroke only. The potential for performance improvements in the breaststroke and butterfly swimming strokes is discussed, with regards to the biomechanical differences and differences in efficiency between these strokes and freestyle. Key PointsCreatine supplementation does not improve single sprint

  10. Biomechanical Analysis of the Swim-Start: A Review

    Directory of Open Access Journals (Sweden)

    Julien Vantorre, Didier Chollet, Ludovic Seifert

    2014-06-01

    Full Text Available This review updates the swim-start state of the art from a biomechanical standpoint. We review the contribution of the swim-start to overall swimming performance, the effects of various swim-start strategies, and skill effects across the range of swim-start strategies identified in the literature. The main objective is to determine the techniques to focus on in swimming training in the contemporary context of the sport. The phases leading to key temporal events of the swim-start, like water entry, require adaptations to the swimmer’s chosen technique over the course of a performance; we thus define the swim-start as the moment when preparation for take-off begins to the moment when the swimming pattern begins. A secondary objective is to determine the role of adaptive variability as it emerges during the swim-start. Variability is contextualized as having a functional role and operating across multiple levels of analysis: inter-subject (expert versus non-expert, inter-trial or intra-subject (through repetitions of the same movement, and inter-preference (preferred versus non-preferred technique. Regarding skill effects, we assume that swim-start expertise is distinct from swim stroke expertise. Highly skilled swim-starts are distinguished in terms of several factors: reaction time from the start signal to the impulse on the block, including the control and regulation of foot force and foot orientation during take-off; appropriate amount of glide time before leg kicking commences; effective transition from leg kicking to break-out of full swimming with arm stroking; overall maximal leg and arm propulsion and minimal water resistance; and minimized energy expenditure through streamlined body position. Swimmers who are less expert at the swim-start spend more time in this phase and would benefit from training designed to reduce: (i the time between reaction to the start signal and impulse on the block, and (ii the time in transition (i

  11. Determinants of the energy cost of front-crawl swimming in children.

    Science.gov (United States)

    Poujade, B; Hautier, C A; Rouard, A

    2002-05-01

    The aim of the present study was to define the determinants of the energy cost of swimming (Cs) in children. Eleven healthy children [mean (SD) age: 12.42 (0.53) years] who practised 7.5-8.5 h x week(-1) volunteered to take part in this study. Anthropometric dimensions such as height (H), body mass (BM), hydrostatic lift (HL) and body surface area (SA) were measured. Forty-eight hours later when maximal oxygen consumption (VO(2max)) had been measured during 400 m of front-crawl swimming, Cs was measured over 200 m for three submaximal swimming speeds (0.9, 1.0 and 1.1 m x s(-1)). Oxygen consumption (Douglas bag method), stroke frequency (SF) and stroke length (SL) were calculated during the last 50 m of each 200 m. The mean (SD) VO(2max) of the young swimmers was 2.19 (0.38) l x min(-1) at a maximal aerobic velocity of 1.19 (0.03) m x s(-1). The values of for Cs at 0.9 m x s(-1), 1.0 m x s(-1) and 1.1 m x s(-1) were 29.27 (3.13) ml x m(-1), 30.25 (3.68) ml x m(-1) and 32.91 (3.59) ml x m(-1), respectively. There was a significant increase in Cs with increasing swim speed. In addition, SF increased with velocity when SL remained constant. The values for SF at 0.9 m x s(-1), 1.0 m x s(-1) and 1.1 m x s(-1) were 31.28 (4.36) strokes x min(-1), 34.10 (5.09) strokes x min(-1) and 38.31 (5.90) strokes x min(-1), respectively. No significant correlation was obtained between Cs and the anthropometric or stroking parameters. It was concluded that for young swimmers, anthropometric characteristics, SF and SL are not good predictors of Cs in front-crawl swimming, and that further studies are needed to explore the influence of underwater torque on Cs in prepubertal children.

  12. VO2 OFF TRANSIENT KINETICS IN EXTREME INTENSITY SWIMMING

    Directory of Open Access Journals (Sweden)

    Ana Sousa

    2011-09-01

    Full Text Available Inconsistencies about dynamic asymmetry between the on- and off- transient responses in oxygen uptake are found in the literature. Therefore, the purpose of this study was to characterize the oxygen uptake off-transient kinetics during a maximal 200-m front crawl effort, as examining the degree to which the on/off regularity of the oxygen uptake kinetics response was preserved. Eight high level male swimmers performed a 200-m front crawl at maximal speed during which oxygen uptake was directly measured through breath-by-breath oxymetry (averaged every 5 s. This apparatus was connected to the swimmer by a low hydrodynamic resistance respiratory snorkel and valve system. Results: The on- and off-transient phases were symmetrical in shape (mirror image once they were adequately fitted by a single-exponential regression models, and no slow component for the oxygen uptake response was developed. Mean (± SD peak oxygen uptake was 69.0 (± 6.3 mL·kg-1·min-1, significantly correlated with time constant of the off- transient period (r = 0.76, p < 0.05 but not with any of the other oxygen off-transient kinetic parameters studied. A direct relationship between time constant of the off-transient period and mean swimming speed of the 200-m (r = 0.77, p < 0.05, and with the amplitude of the fast component of the effort period (r = 0.72, p < 0.05 were observed. The mean amplitude and time constant of the off-transient period values were significantly greater than the respective on- transient. In conclusion, although an asymmetry between the on- and off kinetic parameters was verified, both the 200-m effort and the respectively recovery period were better characterized by a single exponential regression model

  13. Fueling the engine: induction of AMP-activated protein kinase in trout skeletal muscle by swimming.

    Science.gov (United States)

    Magnoni, Leonardo J; Palstra, Arjan P; Planas, Josep V

    2014-05-15

    AMP-activated protein kinase (AMPK) is well known to be induced by exercise and to mediate important metabolic changes in the skeletal muscle of mammals. Despite the physiological importance of exercise as a modulator of energy use by locomotory muscle, the regulation of this enzyme by swimming has not been investigated in fish. We found that sustained swimming (40 days at 0.75 body lengths s(-1)) increased AMPK activity in red and white trout skeletal muscle (3.9- and 2.2-fold, respectively) as well as the expression of AMPK target genes involved in energy use: lipoprotein lipase and citrate synthase in red and white muscle and CPT1β1b and PGC-1α in red muscle. Furthermore, electrical pulse stimulation of cultured trout myotubes increased AMPK activity and glucose uptake (1.9- and 1.2-fold, respectively) in an AMPK-dependent manner. These results suggest that AMPK may play an important mediatory role in the metabolic adaptation to swimming in fish skeletal muscle. © 2014. Published by The Company of Biologists Ltd.

  14. Identification of the Ca2+ conductance responsible for K+-induced backward swimming in Paramecium caudatum.

    Science.gov (United States)

    Oami, K; Takahashi, M

    2002-11-15

    Membrane potential responses of Paramecium caudatum to an application of K+-rich solution were examined to understand the mechanisms underlying K+-induced backward swimming. A wild-type cell impaled by a microelectrode produced action potentials followed by a sustained depolarization in response to an application of a K+-rich test solution. After termination of the application, a prolongation of the depolarization (depolarizing after-potential) took place. Behavioral mutants incapable of exhibiting K+-induced backward swimming did not show depolarizing afterpotentials. Upon short application of K+-rich solution, the timing and duration of the ciliary reversal of the wild-type cell coincided well with the K+-induced depolarization. The duration of the depolarizing afterpotential decreased as the duration of the application increased. The depolarizing afterpotential recovered slowly after it had been suppressed by a preceding application of the K+-rich solution. By injection of an outward current into the wild-type cell, the action potentials were evoked normally during the period when the K+-induced depolarizing afterpotential was suppressed. We concluded that the prolongation of the depolarizing membrane potential response following the application of the K+-rich solution represents the Ca2+ conductance responsible for the K+-induced backward swimming in P. caudatum and that the characteristics of the K+-induced Ca2+ conductance are distinct from those of the Ca2+ conductance responsible for the action potentials.

  15. Paths and patterns: the biology and physics of swimming bacterial populations

    Science.gov (United States)

    Kessler, J. O.; Strittmatter, R. P.; Swartz, D. L.; Wiseley, D. A.; Wojciechowski, M. F.

    1995-01-01

    The velocity distribution of swimming micro-organisms depends on directional cues supplied by the environment. Directional swimming within a bounded space results in the accumulation of organisms near one or more surfaces. Gravity, gradients of chemical concentration and illumination affect the motile behaviour of individual swimmers. Concentrated populations of organisms scatter and absorb light or consume molecules, such as oxygen. When supply is one-sided, consumption creates gradients; the presence of the population alters the intensity and the symmetry of the environmental cues. Patterns of cues interact dynamically with patterns of the consumer population. In suspensions, spatial variations in the concentration of organisms are equivalent to variations of mean mass density of the fluid. When organisms accumulate in one region whilst moving away from another region, the force of gravity causes convection that translocates both organisms and dissolved substances. The geometry of the resulting concentration-convection patterns has features that are remarkably reproducible. Of interest for biology are (1) the long-range organisation achieved by organisms that do not communicate, and (2) that the entire system, consisting of fluid, cells, directional supply of consumables, boundaries and gravity, generates a dynamic that improves the organisms' habitat by enhancing transport and mixing. Velocity distributions of the bacterium Bacillus subtilis have been measured within the milieu of the spatially and temporally varying oxygen concentration which they themselves create. These distributions of swimming speed and direction are the fundamental ingredients required for a quantitative mathematical treatment of the patterns. The quantitative measurement of swimming behaviour also contributes to our understanding of aerotaxis of individual cells.

  16. Numerical investigation of the hydrodynamics of anguilliform swimming in the transitional and inertial flow regimes.

    Science.gov (United States)

    Borazjani, Iman; Sotiropoulos, Fotis

    2009-02-01

    We employ numerical simulation to investigate the hydrodynamic performance of anguilliform locomotion and compare it with that of carangiform swimming as the Reynolds number (Re) and the tail-beat frequency (Strouhal number, St) are systematically varied. The virtual swimmer is a 3-D lamprey-like flexible body undulating with prescribed experimental kinematics of anguilliform type. Simulations are carried out for three Reynolds numbers spanning the transitional and inertial flow regimes, Re=300, 4000 (viscous flow), and infinity (inviscid flow). The net mean force is found to be mainly dependent on the tail-beat frequency rather than the tail-beat amplitude. The critical Strouhal number, St, at which the net mean force becomes zero (constant-speed self-propulsion) is, similar to carangiform swimming, a decreasing function of Re and approaches the range of St numbers at which most anguilliform swimmers swim in nature (St approximately 0.45) only as Re increases. The anguilliform swimmer's force time series is characterized by significantly smaller fluctuations above the mean than that for carangiform swimmers. In stark contrast with carangiform swimmers, the propulsive efficiency of anguilliform swimmers at St is not an increasing function of Re but instead is maximized in the transitional regime. Furthermore, the power required for anguilliform swimming is less than that for the carangiform swimmer at the same Re. We also show that the form drag decreases while viscous drag increases as St increases. Finally, our simulations reinforce our previous finding for carangiform swimmers that the 3-D wake structure depends primarily on the Strouhal number.

  17. Hippocampal mossy fibers and swimming navigation learning in two vole species occupying different habitats.

    Science.gov (United States)

    Pleskacheva, M G; Wolfer, D P; Kupriyanova, I F; Nikolenko, D L; Scheffrahn, H; Dell'Omo, G; Lipp, H P

    2000-01-01

    We showed previously for mice that size differences of the infrapyramidal hippocampal mossy fiber projection (IIP-MF) correlate with spatial learning abilities. In order to clarify the role of the IIP-MF in a natural environment, we studied the bank vole (Clethrionomys glareolus), adapted to a wide range of different habitats, and the root vole (Microtus oeconomus), living in homogenous grassland habitats with small home ranges. Morphometry on Timm-stained horizontal brain sections of six C. glareolus and six M. oeconomus revealed that the size of the entire mossy fiber projection was 42% larger in C. glareolus than M. oeconomus. C. glareolus had also an IIP-MF projection about 230% larger than that of the root vole. A sample of captured animals was then transferred to the laboratory (C. glareolus, n = 23; M. oeconomus, n = 15) and underwent testing for swimming navigation according to a standardized protocol used to assess water maze learning in about 2,000 normal and transgenic mice. Both species learned faster than laboratory mice. Overall escape times showed no differences, but path length was significantly reduced in C. glareolus, which also showed superior performance in a variety of scores assessing spatial search patterns. On the other hand, M. oeconomus showed faster swimming speed, and strong thigmotaxis combined with circular swimming. M. oeconomus also scored at chance levels during the probe trial, about as poorly as mutant knockout mice considered to be deficient in spatial memory. These differences probably reflect differential styles of water maze learning rather than spatial memory deficits: C. glareolus appears to be superior in inhibiting behavior interfering with proper spatial search behavior, while M. oeconomus succeeds in escaping by using rapid circular swimming. We assume that size variations of the IIP-MF correspond to a mechanism stabilizing hippocampal processing during spatial learning or complex activities. This corresponds to the

  18. TUNING IN TO FISH SWIMMING WAVES - BODY FORM, SWIMMING MODE AND MUSCLE FUNCTION

    NARCIS (Netherlands)

    WARDLE, CS; VIDELER, JJ; ALTRINGHAM, JD

    Most fish species swim with lateral body undulations running from head to tail, These waves run more slowly than the waves of muscle activation causing them, reflecting the effect of the interaction between the fish's body and the reactive forces from the water, The coupling between both waves

  19. Combined inhalation of beta2 -agonists improves swim ergometer sprint performance but not high-intensity swim performance

    DEFF Research Database (Denmark)

    Kalsen, Anders; Hostrup, Morten; Bangsbo, Jens

    2014-01-01

    ), in permitted doses within the World Anti-Doping Agency 2013 prohibited list, in elite swimmers with (AHR, n = 13) or without (non-AHR, n = 17) AHR. Maximal voluntary isometric contraction of m. quadriceps (MVC), sprint performance on a swim ergometer and performance in an exhaustive swim test at 110% of VO2max...... were determined. Venous plasma interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured post-exercise. No improvement was observed in the exhaustive swim test, but swim ergometer sprint time was improved (P ...

  20. More efficient swimming by spreading your fingers

    Science.gov (United States)

    van de Water, Willem; van Houwelingen, Josje; Willemsen, Dennis; Breugem, Wim Paul; Westerweel, Jerry; Delfos, Rene; Grift, Ernst Jan

    2016-11-01

    A tantalizing question in free-style swimming is whether the stroke efficiency during the pull phase depends on spreading the fingers. It is a subtle effect-not more than a few percent-but it could make a big difference in a race. We measure the drag of arm models with increasing finger spreading in a wind tunnel and compare forces and moments to the results of immersed boundary simulations. Virtual arms were used in the simulations and their 3D-printed real versions in the experiment. We find an optimal finger spreading, accompanied by a marked increase of coherent vortex shedding. A simple actuator disk model explains this optimum.

  1. Water Penetration into Middle Ear Through Ventilation Tubes in Children While Swimming

    Directory of Open Access Journals (Sweden)

    Mao-Che Wang

    2009-02-01

    Conclusion: Water penetration into the middle ear through ventilation tubes and middle ear infection are not likely when surface swimming. Children with ventilation tubes can enjoy swimming without protection in clean chlorinated swimming pools.

  2. A kinematic and dynamic comparison of surface and underwater displacement in high level monofin swimming

    OpenAIRE

    Nicolas, Guillaume; Bideau, Benoit

    2009-01-01

    Abstract Fin-swimming performance can be divided into underwater and surface water races. World records are about 10% faster for underwater swimming vs. surface swimming, but little is known about the advantage of underwater swimming for monofin swimming. Some authors reported that the air-water interface influences the kinematics and leads to a narrow vertical amplitude of the fin. On the one hand, surface swimming is expected to affect drag parameters (cross-sectional area (S) an...

  3. Kinematic characteristics of the backstroke swimming technique of the qualified swimmers with the effects of cerebral palsy

    Directory of Open Access Journals (Sweden)

    Vasiliy Bosko

    2017-04-01

    Full Text Available Purpose: to determine kinematic characteristics of backstroke swimming technique of athletes with spastic cerebral palsy (CP. Material & Methods: 12 swimmers with consequences of cerebral palsy were involved in the experiment (level of sports qualification – master of sports and candidate of master of sports; Video shooting and computer video analysis of their technique of backstroke swimming; The obtained data were analyzed and generalized using the methods of mathematical statistics. Results: kinematic characteristics of the technique of backstroke swimming of disabled athletes with spastic diplegia and a hemiparetic form of CP, such as the body position of swimmer in water (angle of attack, angle of rotation of the trunk around the longitudinal axis, position and work the hands and feet of the swimmer (the angles of flexion the main joints and their movement, integral characteristics (cycle time, step, rate and ratio of these characteristics at a constant swimmer speed. Conclusions: determined biomechanical characteristics motions skilled swimmers with spastic CP forms, which indicate the specificity of their technique of backstroke swimming, so we recommend that you take into account the findings in the search for effective means and methods of sports training.

  4. The commonest mistakes in the basic swimming techniques after a 20-hour swimming course in the first cycle of the primary school

    OpenAIRE

    Jerina, Nina

    2015-01-01

    The main object of the study in this thesis is identifying the commonest mistakes in the basic swimming techniques after a 20-hour swimming course in the first cycle of the primary school. In our swimming learning system we document the number of swimmers and non-swimmers and titles acquired to eight-scale ranking (Slovenian scale for assessing swimming skills), but we do not document the correctness of performed swimming technique. Consequently we do not have information about the common...

  5. Viscoelasticity promotes collective swimming of sperm

    Science.gov (United States)

    Tung, Chih-Kuan; Harvey, Benedict B.; Fiore, Alyssa G.; Ardon, Florencia; Suarez, Susan S.; Wu, Mingming

    From flocking birds to swarming insects, interactions of organisms large and small lead to the emergence of collective dynamics. Here, we report striking collective swimming of bovine sperm, with sperm orienting in the same direction within each cluster, enabled by the viscoelasticity of the fluid. A long-chain polyacrylamide solution was used as a model viscoelastic fluid such that its rheology can be fine-tuned to mimic that of bovine cervical mucus. In viscoelastic fluid, sperm formed dynamic clusters, and the cluster size increased with elasticity of the polyacrylamide solution. In contrast, sperm swam randomly and individually in Newtonian fluids of similar viscosity. Analysis of the fluid motion surrounding individual swimming sperm indicated that sperm-fluid interaction is facilitated by the elastic component of the fluid. We note that almost all biological fluids (e.g. mucus and blood) are viscoelastic in nature, this finding highlights the importance of fluid elasticity in biological function. We will discuss what the orientation fluctuation within a cluster reveals about the interaction strength. Supported by NIH Grant 1R01HD070038.

  6. Nutrition considerations for open-water swimming.

    Science.gov (United States)

    Shaw, Gregory; Koivisto, Anu; Gerrard, David; Burke, Louise M

    2014-08-01

    Open-water swimming (OWS) is a rapidly developing discipline. Events of 5-25 km are featured at FINA World Championships, and the international circuit includes races of 5-88 km. The Olympic OWS event, introduced in 2008, is contested over 10 km. Differing venues present changing environmental conditions, including water and ambient temperatures, humidity, solar radiation, and unpredictable tides. Furthermore, the duration of most OWS events (1-6 hr) creates unique physiological challenges to thermoregulation, hydration status, and muscle fuel stores. Current nutrition recommendations for open-water training and competition are either an extension of recommendations from pool swimming or are extrapolated from other athletic populations with similar physiological requirements. Competition nutrition should focus on optimizing prerace hydration and glycogen stores. Although swimmers should rely on self-supplied fuel and fluid sources for shorter events, for races of 10 km or greater, fluid and fuel replacement can occur from feeding pontoons when tactically appropriate. Over the longer races, feeding pontoons should be used to achieve desirable targets of up to 90 g/ hr of carbohydrates from multitransportable sources. Exposure to variable water and ambient temperatures will play a significant role in determining race nutrition strategies. For example, in extreme environments, thermoregulation may be assisted by manipulating the temperature of the ingested fluids. Swimmers are encouraged to work with nutrition experts to develop effective and efficient strategies that enhance performance through appropriate in-competition nutrition.

  7. Intrinsic viscosity of actively swimming microalgae suspensions

    Science.gov (United States)

    Ewoldt, Randy; Caretta, Lucas; Chengala, Anwar; Sheng, Jian

    2011-11-01

    Suspensions of actively swimming microorganisms exhibit an effective viscosity which may depend on volume fraction, cell shape, and the nature of locomotion (e.g. ``pushers'' vs. ``pullers''). Although several dilute-regime theories have been offered for active suspensions, no experimental study to our knowledge has been able to resolve the dilute-regime intrinsic viscosity of actively swimming microorganism suspensions. Here we use a cone-and-plate rheometer to experimentally measure the dynamic shear viscosity for motile and non-motile suspensions of unicellular green algae (Dunaliella primolecta, a biflagellated ``puller''). The low viscosity biological samples require careful experimental protocols to avoid settling and flow-induced migration, and to minimize precision error. With these protocols in place we can distinguish the intrinsic viscosity which we show is higher for the motile ``puller'' swimmers compared to the immobilized counterparts. This observation is consistent with recently proposed dilute-regime theories which predict that ``pullers'' should have a higher viscosity than non-motile suspensions.

  8. The Complex Hydrodynamics of Swimming in the Spanish Dancer

    Science.gov (United States)

    Zhou, Zhuoyu; Mittal, Rajat

    2016-11-01

    The lack of a vertebra seems to have freed marine gastropods to explore and exploit a stupendous variety of swimming kinematics. In fact, examination of just a few animals in this group reveal locomotory modes ranging from insect-like flapping, to fish-like undulatory swimming, jet propulsion, and rajiform (manta-like) swimming. There are also a number of marine gastropods that have bizarre swimming gaits with no equivalent among fish or marine mammals. In this latter category is the Spanish Dancer (Hexabranchus sanguineus) a sea slug that swims with a complex combination of body undulations and flapping parapodia. While the neurobiology of these animals has been relatively well-studied, less is known about their propulsive mechanism and swimming energetics. In this study, we focus on the hydrodynamics of two distinct swimmers: the Spanish Dancer, and the sea hare Aplysia; the latter adopts a rajiform-like mode of swimming by passing travelling waves along its parapodia. In the present study an immersed boundary method is employed to examine the vortex structures, hydrodynamic forces and energy costs of the swimming in these animals. NSF Grant No. 1246317.

  9. How to improve hygienic behaviour in holiday park swimming pools

    NARCIS (Netherlands)

    Stronks, I.; Keuten, M.G.A.

    2016-01-01

    Previous studies on contamination of swimming pool water showed that the hygienic behaviour of swimmers is the most important factor. The suggested hygienic behaviour is; having a pre-swim shower and using the toilet when nature calls. Knowing the importance of hygienic behaviour is one thing,

  10. Swimming & Diving: Special Olympics Sports Skills Instructional Program.

    Science.gov (United States)

    Joseph P. Kennedy, Jr. Foundation, Washington, DC.

    One of five parts of the Special Olympics' Sports Skills Instructional Program, the booklet addresses ways to teach swimming and diving to mentally retarded students. Short term objectives of the program encompass warmup, basic swimming and diving skills, safety, and good sportsmanship. The long term goal focuses on acquisition of basic skills,…

  11. 78 FR 23329 - Aircraft Access to SWIM Working Group Meeting

    Science.gov (United States)

    2013-04-18

    ... Federal Aviation Administration Aircraft Access to SWIM Working Group Meeting Meeting Announcement... attend and participate in an Aircraft Access to SWIM Working Group Meeting scheduled for Thursday, May 16..., Phone Number, U.S. Citizen (Y/N). RSVPs to Corey Muller are required by COB May 1, 2013. Aircraft Access...

  12. Stokesian swimming of a sphere at low Reynolds number

    CERN Document Server

    Felderhof, B U

    2016-01-01

    Explicit expressions are derived for the matrices determining the mean translational and rotational swimming velocities and the mean rate of dissipation for Stokesian swimming at low Reynolds number of a distorting sphere in a viscous incompressible fluid. As an application an efficient helical propeller-type stroke is found and its properties are calculated.

  13. Relationship between Muscle Strength and Front Crawl Swimming Velocity

    Directory of Open Access Journals (Sweden)

    Gola Radosław

    2014-08-01

    Full Text Available Purpose. competitive performance in swimming depends on a number of factors including, among others, the development of relevant muscle groups. The aim of the study was to clarify the relationship between muscle strength and swimming velocity and the role of individual muscle groups in front crawl swimming. Methods. sixteen physical education university students participated in the study. The strength values, defined as torque produced during isometric contractions, of eight upper and lower extremity muscle groups were measured. Data were compared with participants' front crawl swim times in the 25m and 50m distances. Results. correlation analysis demonstrated a relationship between muscle strength and swimming velocity. statistically significant relationships were observed between swimming velocity and the torque values of the elbow flexor and shoulder extensor muscles as well as the sum of upper extremity muscle torque values (p ⋋ 0.05. Conclusions. The results indicate the need for a focus on training those muscle groups identified as having a statistically significant relationship with swimming velocity for a given distance, as the sample showed deficiencies in the strength of those muscle groups responsible for generating propulsive force in the front crawl. Additionally, the collected data can serve as a diagnostic tool in evaluating the development of muscle groups critical for swimming performance.

  14. Quantification of continual anthropogenic pollutant release in swimming pools (poster)

    NARCIS (Netherlands)

    Peters, M.C.F.M.; Keuten, M.G.A.; Daanen, H.; De Kreuk, M.K.; Rietveld, L.C.; Van Loosdrecht, M.C.M.; Dijk, H.

    2013-01-01

    The amount of pollutants brought into the swimming pool water by swimmers is called anthropogenic pollutant release. The continual pollutant release is the amount of pollutants which is released during the submerged swimming period. The actual level of the continual pollutant release has not been

  15. A meta-analysis of steady undulatory swimming

    NARCIS (Netherlands)

    van Weerden, J. Fransje; Reid, Daniel A. P.; Hemelrijk, Charlotte K.

    The mechanics underlying undulatory swimming are of great general interest, both to biologists and to engineers. Over the years, more data of the kinematics of undulatory swimming have been reported. At present, an integrative analysis is needed to determine which general relations hold between

  16. Metabolic Responses to Swimming Exercise in the Infected Rat.

    Science.gov (United States)

    1981-06-29

    but were only slightly diminished in noninfected controls. Swimming also caused an amplification of fasting ketosis (Fig. 4). During infection, induced... ketosis , the increase in hepatic ketogenesis coming from elevated lipolysis and FFA utilization under hormonal influence. Results indicate that swimming

  17. Physiological responses to swimming fatigue of juvenile white-leg ...

    African Journals Online (AJOL)

    Swimming performance is one of the crucial factors determining the lifestyle and survival of Penaeid shrimps. This study examined under controlled laboratory conditions, the physiological responses to swimming fatigue of juvenile white-leg shrimp Litopenaeus vannamei (8.85 ± 0.05 cm TL) exposed to different current ...

  18. Glucocorticoids facilitate the retention of acquired immobility during forced swimming

    NARCIS (Netherlands)

    Veldhuis, H D; De Korte, C C; De Kloet, E R

    1985-01-01

    The adrenalectomy-induced decrease in the level of immobility during a 5 min retest period in the Porsolt swimming test could be reversed by glucocorticoids administered s.c. 15 min after the initial forced swimming exposure. The synthetic glucocorticoids dexamethasone and RU 28362 were active in

  19. Health risks associated with swimming at an inland river

    Science.gov (United States)

    Swimming exposure to fecally-contaminated oceans and lakes has been associated with an increased risk of gastrointestinal (GI) illness. Although treated and untreated sewage are often discharged to rivers, the health risks of swimming exposure on rivers has been less frequently ...

  20. 33 CFR 117.734 - Navesink River (Swimming River).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navesink River (Swimming River). 117.734 Section 117.734 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1 through...

  1. Wild-type Zebrafish subjected to swim-training

    NARCIS (Netherlands)

    Fiaz, Ansa

    2014-01-01

    Genome-wide microarray analysis of the effects of swim-training on zebrafish larval development. Zebrafish were subjected to swim-training from 5 days post fertilization (dpf) until 10 dpf. Subsequently, we performed a genome-wide microarray analysis of trained and control fish at 10 dpf. The goal

  2. Efficacy of a modified tapering protocol on swimming performance ...

    African Journals Online (AJOL)

    Total time and split times for each length, stroke rate, distance per stroke, and stroke index in a performance swim were determined as well as heart rate (HR), profile of mood state (POMS), rating of perceived exertion (RPE) and muscle pain during each taper. Results. Mean swim times for the modified and conventional ...

  3. Peculiarities of a backstroke swimming technique acceleration in elementary education

    Directory of Open Access Journals (Sweden)

    Liliya Sheyko

    2016-02-01

    Full Text Available Purpose: to research the possibility of intensification and improvement of the efficiency of swimming training for adults by use of accelerated learning backstroke swimming techniques. Material & Methods: the study involved a total of 43 people aged 30–40 years. Applied: analysis and generalization of scientific and methodological literature; analysis of the learning process of swimming training for adults; development and approbation of an accelerated backstroke swimming technique on the base of the recreational sports complex LLC «Technocom» (Kharkiv, Author's swimming school of U. Blyzniuk, teacher observation, experiment. Results: a study shows that developing of swimming skills of people tested occurs faster and more effectively if the accelerated procedure is used. Backstroke swimming skill formation time for examinees: check group had 26 to 36 lessons, there were 25 to 32 exercises with and without use of supporting means; the experimental group had 12 to 24 lessons with use of 15 exercises without supporting means. Conclusions: as a result of the experiment, it was found that the use of the proposed accelerated training method allows to intensify backstroke swimming learning process for people aged 30–40, due to training course total duration reduction (2 times and number of exercises used, and also allows to master quicker the main improving distance according to age of the engaged.

  4. Evaluation of swimming performance for fish passage of longnose dace Rhinichthys cataractae using an experimental flume.

    Science.gov (United States)

    Dockery, D R; McMahon, T E; Kappenman, K M; Blank, M

    2017-03-01

    The swimming performance of longnose dace Rhinichthys cataractae, the most widely distributed minnow (Cyprinidae) in North America, was assessed in relation to potential passage barriers. The study estimated passage success, maximum ascent distances and maximum sprint speed in an open-channel flume over a range of water velocities and temperatures (10·7, 15·3 and 19·3° C). Rhinichthys cataractae had high passage success (95%) in a 9·2 m flume section at mean test velocities of 39 and 64 cm s(-1) , but success rate dropped to 66% at 78 cm s(-1) . Only 20% of fish were able to ascend a 2·7 m section with a mean velocity of 122 cm s(-1) . Rhinichthys cataractae actively selected low-velocity pathways located along the bottom and corners of the flume at all test velocities and adopted position-holding behaviour at higher water velocities. Mean volitional sprint speed was 174 cm s(-1) when fish volitionally sprinted in areas of high water velocities. Swimming performance generally increased with water temperature and fish length. Based on these results, fishways with mean velocities 100 cm s(-1) within structures should be limited to short distance (swimming performance metrics in an open-channel flume, which can simulate the hydraulic features of fishways and allow for behavioural observations that can facilitate the design of effective passage structures. © 2016 The Fisheries Society of the British Isles.

  5. Enhancement of microbial motility due to speed-dependent nutrient absorption

    CERN Document Server

    Di Salvo, Mario E

    2013-01-01

    Marine microorganisms often reach high swimming speeds, either to take advantage of evanescent nutrient patches or to beat Brownian forces. Since this implies that a sizable part of their energetic budget must be allocated to motion, it is reasonable to assume that some fast-swimming microorganisms may increase their nutrient intake by increasing their speed v. We formulate a model to investigate this hypothesis and its consequences, finding the steady state solutions and analyzing their stability. Surprisingly, we find that even modest increases in nutrient absorption may lead to a significant increase of the microbial speed. In fact, evaluations obtained using realistic parameter values for bacteria indicate that the speed increase due to the enhanced nutrient absorption may be quite large.

  6. In-silico experiments of zebrafish behaviour: modeling swimming in three dimensions

    Science.gov (United States)

    Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

    2017-01-01

    Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to reduce the number of subjects, refine experimental designs, and replace live animals. Inspired by the demonstrated advantages of computational studies in other life science domains, we establish an authentic data-driven modelling framework to simulate zebrafish swimming in three dimensions. The model encapsulates burst-and-coast swimming style, speed modulation, and wall interaction, laying the foundations for in-silico experiments of zebrafish behaviour. Through computational studies, we demonstrate the ability of the model to replicate common ethological observables such as speed and spatial preference, and anticipate experimental observations on the correlation between tank dimensions on zebrafish behaviour. Reaching to other experimental paradigms, our framework is expected to contribute to a reduction in animal use and suffering.

  7. Swimming bacteria promote dispersal of non-motile staphylococcal species.

    Science.gov (United States)

    Samad, Tahoura; Billings, Nicole; Birjiniuk, Alona; Crouzier, Thomas; Doyle, Patrick S; Ribbeck, Katharina

    2017-08-01

    Swimming motility is considered a beneficial trait among bacterial species as it enables movement across fluid environments and augments invasion of tissues within the host. However, non-swimming bacteria also flourish in fluid habitats, but how they effectively spread and colonize distant ecological niches remains unclear. We show that non-motile staphylococci can gain motility by hitchhiking on swimming bacteria, leading to extended and directed motion with increased velocity. This phoretic interaction was observed between Staphylococcus aureus and Pseudomonas aeruginosa, Staphylococcus epidermidis and P. aeruginosa, as well as S. aureus and Escherichia coli, suggesting hitchhiking as a general translocation mechanism for non-motile staphylococcal species. By leveraging the motility of swimming bacteria, it was observed that staphylococci can colonize new niches that are less available in the absence of swimming carriers. This work highlights the importance of considering interactions between species within polymicrobial communities, in which bacteria can utilize each other as resources.

  8. EFFECT OF FLEXIBILITY ON THE RESULTS OF DOLPHIN SWIMMING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Slađana Tošić

    2011-09-01

    Full Text Available In order to determine the impact of flexibility on the results in swimming, we conducted a study on a sample of 50 female patients aged 11-14 years of age who are in the training process in the swimming clubs „Nis 2005“ and „Sveti Nikola“ in Nis. The study is applied to 14 measuring instruments that were divided into three groups: Measuring instruments for the assessment of flexibility (11; Measuring instruments for assessing the results of swimming (1; Measuring instruments for evaluation of morphological characteristics (2. The regression analysis determined the impact of flexibility on the results in swimming. The regression analysis didn't confirmed the assumption that there is a statistically significant effect of flexibility variables on results in swimming for female swimmers

  9. The effects of swimming exercise and dissolved oxygen on growth performance, fin condition and precocious maturation of early-rearing Atlantic salmon Salmo salar

    Science.gov (United States)

    Waldrop, Thomas; Summerfelt, Steven T.; Mazik, Patricia M.; Good, Christopher

    2018-01-01

    Swimming exercise, typically measured in body-lengths per second (BL/s), and dissolved oxygen (DO), are important environmental variables in fish culture. While there is an obvious physiological association between these two parameters, their interaction has not been adequately studied in Atlantic salmon Salmo salar. Because exercise and DO are variables that can be easily manipulated in modern aquaculture systems, we sought to assess the impact of these parameters, alone and in combination, on the performance, health and welfare of juvenile Atlantic salmon. In our study, Atlantic salmon fry were stocked into 12 circular 0.5 m3 tanks in a flow-through system and exposed to either high (1.5–2 BL/s) or low (<0.5 BL/s) swimming speeding and high (100% saturation) or low (70% saturation) DO while being raised from 10 g to approximately 350 g in weight. Throughout the study period, we assessed the impacts of exercise and DO concentration on growth, feed conversion, survival and fin condition. By study's end, both increased swimming speed and higher DO were independently associated with a statistically significant increase in growth performance (p < .05); however, no significant differences were noted in survival and feed conversion. Caudal fin damage was associated with low DO, while right pectoral fin damage was associated with higher swimming speed. Finally, precocious male sexual maturation was associated with low swimming speed. These results suggest that providing exercise and dissolved oxygen at saturation during Atlantic salmon early rearing can result in improved growth performance and a lower incidence of precocious parr.

  10. Effect of ectoparasite infestation density and life history stages on the swimming performance of Atlantic salmon Salmo salar

    Directory of Open Access Journals (Sweden)

    Samantha Bui

    2016-06-01

    Full Text Available To overcome sustainability obstacles and improve operations, the Atlantic salmon farming industry is testing novel approaches to production. Redistributing farm sites to offshore locations is one such solution; however, tolerance to high-current velocity sites must be considered, particularly if fish health status is compromised by parasites. We tested the effect of parasite density and life-history stage on the swimming performance of Atlantic salmon Salmo salar using a swim flume. Salmon with 3 different salmon lice Lepeophtheirus salmonis densities (0, 0.02 � 0.01 and 0.11 � 0.01 lice cm-2 [mean � SE] were tested across the 4 major life-history stages of lice (copepodid, chalimus, pre-adult and adult for critical swimming performance (Ucrit. Salmon Ucrit declined slightly by a mean of 0.04 to 0.10 body lengths s-1 with high parasite densities compared to uninfested and low densities, across the lice stages, while progression through the parasite life-history stages had little effect on swimming performance. Our results suggest that increasing infestation density of salmon lice incurs negative fitness consequences for farmed Atlantic salmon held in high-current velocity sites, with little difference in costs associated with attachment by different life-history stages of the lice.

  11. Effect of the underwater torque on the energy cost, drag and efficiency of front crawl swimming.

    Science.gov (United States)

    Zamparo, P; Capelli, C; Termin, B; Pendergast, D R; di Prampero, P E

    1996-01-01

    Underwater torque (T') is defined as the product of the force with which the swimmer's feet tend to sink times the distance between the feet and the centre of volume of the lungs. It has previously been shown that experimental changes of T', obtained by securing around the swimmer's waist a plastic tube filled, on different occasions, with air, water or 2-kg lead, were accompanied by changes in the energy cost of swimming per unit of distance (Cs) at any given speed. The aim of this study was to investigate whether the observed increases of Cs with T' during front crawl swimming were due to an increase of active body drag (Db), a decrease of drag efficiency (eta /d) or both. The effect of experimental changes of T' on Cs, Db and eta /d were therefore studied on a group of eight male elite swimmers at two submaximal speeds (1.00 and 1.23 m.s-1). To compare different subjects and different speeds, the individual data for Cs, Db, eta /d and T' were normalized dividing them by the corresponding individual averages. These were calculated from all individual data (of Cs, Db, eta /d and T') obtained from that subject at that speed. It was found that, between the two extremes of this study (tube filled with air and with 2-kg lead), T' increased by 73% and that Cs, Db and eta /d increased linearly with T'. The increase of Cs between the two extremes was intermediate (approximately 20%) between that of Db (approximately 35%) and of eta /d (approximately 16%). Thus, the actual strategy implemented by the swimmers to counteract T', was to tolerate a large increase of Db. This led also to a substantial (albeit smaller) increase of r/d, the effect of which was to reduce the increase of Cs that would otherwise have occurred.

  12. The swimming behavior of Artemia (Anostraca): new experimental and observational data.

    Science.gov (United States)

    Anufriieva, Elena V; Shadrin, Nickolai V

    2014-12-01

    Artemia (Anostraca) is among the most primitive and ancient groups of crustaceans. Artemia spp. play a dominant role in the ecosystems of hypersaline waters, and often they are the only animals in these extreme biotopes. Most ethological studies on Artemia have been conducted on nauplii and metanauplii. We made ethological observations on Artemia under laboratory conditions and in the natural waters of Crimea, where we studied growth and ontogenetic changes of swimming behavior. Growth occurred during the first 50 days up to a size of 9.5-10.5mm, after which time the size did not increase (some females lived up to 6.5 months). A strong positive relation was found between maximal speed and individual length, which varied between 0.4 and 10.5mm; it may be approximated by the power equation: Vmax=1.205·K(0.820), where Vmax is the maximal speed of Artemia (in mms(-1)) of the length K (in mm). There is no similar relation between average speed and length of Artemia. The average speed of adults was 40-60% lower in environments with microalgae compared to media without food. The duration of the "riding position" for mating pairs of Artemia urmiana in our experiments varied from 10 to 27 days. In lakes we observed different Artemia aggregations varying in size and form. We conclude that the swimming behavior of Artemia is quite complex and diverse, and develops during ontogeny. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Sustainable Food & Sustainable Economics

    OpenAIRE

    Alvarez, Mavis Dora

    2012-01-01

    Cuba today is immersed in a very intense process of perfecting its agricultural production structures with the goal of making them more efficient and sustainable in their economic administration and in their social and environmental management. Agricultural cooperatives in Cuba have the responsibility of producing on 73% of the country's farmland. Their contributions are decisive to developing agricultural production and to ensuring more and better food for the population, in addition to redu...

  14. Swimming metabolic rates vary by sex and development stage, but not by species, in three species of Australian otariid seals.

    Science.gov (United States)

    Ladds, Monique A; Slip, David J; Harcourt, Robert G

    2017-04-01

    Physiology may limit the ability for marine mammals to adapt to changing environments. Depth and duration of foraging dives are a function of total available oxygen stores, which theoretically increase as animals grow, and metabolic costs. To evaluate how physiology may influence the travelling costs for seals to foraging patches in the wild, we measured metabolic rates of a cross-section of New Zealand fur seals, Australian fur seals and Australian sea lions representing different foraging strategies, development stages, sexes and sizes. We report values for standard metabolic rate, active metabolic rate (obtained from submerged swimming), along with estimates of cost of transport (COT), measured via respirometry. We found a decline in mass-specific metabolic rate with increased duration of submerged swimming. For most seals mass-specific metabolic rate increased with speed and for all seals mass-specific COT decreased with speed. Mass-specific metabolic rate was higher for subadult than adult fur seals and sea lions, corresponding to an overall higher minimum COT. Some sex differences were also apparent, such that female Australian fur seals and Australian sea lions had higher mass-specific metabolic rates than males. There were no species differences in standard or active metabolic rates for adult males or females. The seals in our study appear to operate at their physiological optimum during submerged swimming. However, the higher metabolic rates of young and female fur seals and sea lions may limit their scope for increasing foraging effort during times of resource limitation.

  15. Swimming and Persons with Mild Persistant Asthma

    Directory of Open Access Journals (Sweden)

    Mirjana Arandelovic

    2007-01-01

    Full Text Available The aim of our study was to analyze the effect of recreational swimming on lung function and bronchial hyperresponsiveness (BHR in patients with mild persistent asthma. This study included 65 patients with mild persistent asthma, who were divided into two groups: experimental group A (n = 45 and control group B (n = 20. Patients from both groups were treated with low doses of inhaled corticosteroids (ICS and short-acting β2 agonists salbutamol as needed. Our program for patients in group A was combined asthma education with swimming (twice a week on a 1-h basis for the following 6 months. At the end of the study, in Group A, we found a statistically significant increase of lung function parameters FEV1 (forced expiratory volume in 1 sec (3.55 vs. 3.65 (p < 0.01, FVC (forced vital capacity (4.27 vs. 4.37 (p < 0.05, PEF (peak expiratory flow (7.08 vs. 7.46 (p < 0.01, and statistically significant decrease of BHR (PD20 0.58 vs. 2.01 (p < 0.001. In Group B, there was a statistically significant improvement of FEV1 3.29 vs. 3.33 (p < 0.05 and although FVC, FEV1/FVC, and PEF were improved, it was not significant. When Groups A and B were compared at the end of the study, there was a statistically significant difference of FVC (4.01 vs. 4.37, FEV1 (3.33 vs. 3.55, PEF (6.79 vs.7.46, and variability (p <0.001, and statistically significantly decreased BHR in Group A (2.01 vs. 1.75 (p < 0.001. Engagement of patients with mild persistent asthma in recreational swimming in nonchlorinated pools, combined with regular medical treatment and education, leads to better improvement of their parameters of lung function and also to more significant decrease of their airway hyperresponsiveness compared to patients treated with traditional medicine

  16. The effects of feeding on the swimming performance and metabolic response of juvenile southern catfish, Silurus meridionalis, acclimated at different temperatures.

    Science.gov (United States)

    Pang, Xu; Cao, Zhen-Dong; Peng, Jiang-Lan; Fu, Shi-Jian

    2010-02-01

    To test whether the effects of feeding on swimming performance vary with acclimation temperature in juvenile southern catfish (Silurus meridionalis), we investigated the specific dynamic action (SDA) and swimming performance of fasting and feeding fish at acclimation temperatures of 15, 21, 27, and 33 degrees C. Feeding had no effect on the critical swimming speeding (U(crit)) of fish acclimated at 15 degrees C (p=0.66), whereas it elicited a 12.04, 18.70, and 20.98% decrease in U(crit) for fish acclimated at 21, 27 and 33 degrees C, respectively (pcatfish's central cardio-respiratory, peripheral digestive and locomotory capacities. The different metabolic strategies of juvenile southern catfish at different temperatures may relate to changes in oxygen demand, imbalances in ion fluxes and dissolved oxygen levels with changes in temperature. 2009 Elsevier Inc. All rights reserved.

  17. High speed data converters

    CERN Document Server

    Ali, Ahmed MA

    2016-01-01

    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  18. To Swim or Not to Swim: Potential Transmission of Balaenophilus manatorum (Copepoda: Harpacticoida in Marine Turtles.

    Directory of Open Access Journals (Sweden)

    Francesc Domènech

    Full Text Available Species of Balaenophilus are the only harpacticoid copepods that exhibit a widespread, obligate association with vertebrates, i.e., B. unisetus with whales and B. manatorum with marine turtles and manatees. In the western Mediterranean, juveniles of the loggerhead sea turtle, Caretta caretta are the only available hosts for B. manatorum, which has been found occurring at high prevalence (>80% on them. A key question is how these epibionts are transmitted from host to host. We investigated this issue based on experiments with live specimens of B. manatorum that were cultured with turtle skin. Specimens were obtained from head-started hatchlings of C. caretta from the western Mediterranean. Hatched nauplii crawled only on rough substrates and lacked the ability to swim. Only copepodites IV and V, and adults, were able to perform directional swimming. Legs 2, 3 and 4 played a major role in swimming and were only well-developed in these stages. Nauplii reared in wells with turtle skin readily fed on this item. Late copepodites and adults also fed on turtle skin but did not consume other potential food items such as fish skin, baleen plates or planktonic algae. Evidences suggest that the transmission of B. manatorum should rely on hosts' bodily contacts and/or swimming of late developmental stages between spatially close hosts. The possibility of long-ranged dispersal is unlikely for two reasons. First, all developmental stages seem to depend on turtle skin as a food resource. Second, the average clutch size of ovigerous females was small (< 70 eggs for free-living phases to successfully contact turtles that occur at very low densities (< 0.6 turtles·km-2 in the western Mediterranean. The high prevalence of B. manatorum in loggerhead turtles in this area raises the question whether these turtles have contacts, or tend to closely aggregate, more than is currently believed.

  19. EFFECTS OF SODIUM BICARBONATE INGESTION ON SWIM PERFORMANCE IN YOUTH ATHLETES

    Directory of Open Access Journals (Sweden)

    Jozef Langfort

    2009-03-01

    Full Text Available The purpose of this study was to evaluate the effect of oral administration of sodium bicarbonate (300 mg·kg-1 b.w. on swim performance in competitive, (training experience of 6.6 ± 0.6 years youth, (15.1 ± 0.6 years male swimmers. The subjects completed a test trial, in a double blind fashion, on separate days, consisting of 4 x 50m front crawl swims with a 1st minute passive rest interval twice, on two occasions: after ingestion of bicarbonate or placebo, 72 hours apart, at the same time of the day. Blood samples were drawn from the finger tip three times during each trial; upon arrival to the laboratory, 60 min after ingestion of placebo or the sodium bicarbonate solution and after the 4 x 50m test, during the 1st min of recovery. Plasma lactate concentration, blood pH, standard bicarbonate and base excess were evaluated. The total time of the 4 x 50 m test trial improved from 1.54.28 to 1.52.85s, while statistically significant changes in swimming speed were recorded only during the first 50m sprint (1.92 vs. 1.97 m·s-1, p < 0.05. Resting blood concentration of HCO-3 increased following the ingestion of sodium bicarbonate from 25.13 to 28.49 mM (p < 0.05. Sodium bicarbonate intake had a statistically significant effect on resting blood pH (7.33 vs. 7.41, p < .05 as well as on post exercise plasma lactate concentration (11.27 vs. 13.06 mM, p < 0.05. Collectively, these data demonstrate that the ingestion of sodium bicarbonate in youth athletes is an effective buffer during high intensity interval swimming and suggest that such a procedure can be used in youth athletes to increase training intensity as well as swimming performance in competition at distances from 50 to 200 m

  20. Behavioral Dynamics in Swimming: The Appropriate Use of Inertial Measurement Units

    Science.gov (United States)

    Guignard, Brice; Rouard, Annie; Chollet, Didier; Seifert, Ludovic

    2017-01-01

    Motor control in swimming can be analyzed using low- and high-order parameters of behavior. Low-order parameters generally refer to the superficial aspects of movement (i.e., position, velocity, acceleration), whereas high-order parameters capture the dynamics of movement coordination. To assess human aquatic behavior, both types have usually been investigated with multi-camera systems, as they offer high three-dimensional spatial accuracy. Research in ecological dynamics has shown that movement system variability can be viewed as a functional property of skilled performers, helping them adapt their movements to the surrounding constraints. Yet to determine the variability of swimming behavior, a large number of stroke cycles (i.e., inter-cyclic variability) has to be analyzed, which is impossible with camera-based systems as they simply record behaviors over restricted volumes of water. Inertial measurement units (IMUs) were designed to explore the parameters and variability of coordination dynamics. These light, transportable and easy-to-use devices offer new perspectives for swimming research because they can record low- to high-order behavioral parameters over long periods. We first review how the low-order behavioral parameters (i.e., speed, stroke length, stroke rate) of human aquatic locomotion and their variability can be assessed using IMUs. We then review the way high-order parameters are assessed and the adaptive role of movement and coordination variability in swimming. We give special focus to the circumstances in which determining the variability between stroke cycles provides insight into how behavior oscillates between stable and flexible states to functionally respond to environmental and task constraints. The last section of the review is dedicated to practical recommendations for coaches on using IMUs to monitor swimming performance. We therefore highlight the need for rigor in dealing with these sensors appropriately in water. We explain the

  1. Thrust production by a mechanical swimming lamprey

    Science.gov (United States)

    Leftwich, M. C.; Smits, A. J.

    2011-05-01

    To develop a comprehensive model of lamprey locomotion, we use a robotic lamprey to investigate the formation of the wake structure, the shedding vorticity from the body, and the relationship between thrust production and pressure on the surface of the robot. The robot mimics the motion of living lamprey in steady swimming by using a programmable microcomputer to actuate 13 servomotors that produce a traveling wave along the length of the lamprey body. The amplitude of the phase-averaged surface pressure distribution along the centerline of the robot increases toward the tail, which is consistent with previous momentum balance experiments. This indicates that thrust is produced mainly at the tail. The phase relationship between the pressure signal and the vortex shedding from the tail is also examined, showing a clear connection between the location of vortex structures and the fluctuations of the pressure signal.

  2. A Study of a Mechanical Swimming Lamprey

    Science.gov (United States)

    Leftwich, Megan; Hultmark, Marcus; Smits, Alexander

    2007-11-01

    In order to develop a comprehensive model of lamprey locomotion, we use a swimming robotic lamprey as a means of investigating the surface pressure, thrust and wake structure. A programmable microcomputer actuates 13 servomotors that produce a traveling wave along the length of the lamprey's body. This waveform is based on the motion of the American eel (Anguilla rostrata), as described by Tytell and Lauder (2004). Dye flow visualization and particle image velocimetry (PIV) are used to study the wake structure generated by the robot and the flowfield along the body. These visualization methods show that two distinct, oppositely signed vortices are shed each half cycle; whereas along the body, no large scale vortical shedding can be observed, suggesting that most of the thrust is produced by the tail. Thrust data based on momentum balances support this suggestion. The project is supported by NIH Grant 1RO1NS054271.

  3. Thrust Production in a Mechanical Swimming Lamprey

    Science.gov (United States)

    Leftwich, Megan; Smits, Alexander

    2008-11-01

    To develop a comprehensive model of lamprey locomotion, we use a robotic lamprey as a means of investigating the surface pressure and wake structure during swimming. A programmable microcomputer actuates 11 servomotors that produce a traveling wave along the length of the lamprey body. The waveform is based on the motion of the American eel (Anguilla rostrata), as described by Tytell and Lauder (2004) and kinematic studies of living lamprey. The amplitude of the phase-averaged surface pressure distribution along the centerline of the robot increases toward the tail, which is consistent with previous momentum balance experiments indicating that thrust is produced mainly at the tail. The phase relationship between the pressure signal and the vortex shedding from the tail is also examined. The project is supported by NIH CNRS Grant 1R01NS054271.

  4. Effective viscosity of actively swimming algae suspensions

    Science.gov (United States)

    Ewoldt, Randy; Caretta, Lucas; Chengala, Anwar; Sheng, Jian

    2010-11-01

    Suspensions of actively swimming microorganisms exhibit an effective viscosity which may depend on volume fraction, cell shape, and the nature of locomotion (e.g. "pushers" vs. "pullers"). Here we report experimental measurements of shear viscosity for suspensions of unicellular green algae (Dunaliella primolecta, a biflagellated "puller"). We use a cone-and-plate rheometer to measure the dynamic shear viscosity for both motile and non-motile suspensions of D. primolecta. Viscosity increases with concentration for both cases, but the active suspensions of "pullers" have a comparatively lower effective viscosity than passive suspensions. This observation contrasts recently proposed theories which predict that "pullers" should instead have a higher viscosity than non-motile suspensions. Additionally, we observe shear-induced migration of active suspensions and consider its impact on the resulting effective shear viscosity.

  5. Forces and energetics of intermittent swimming

    Science.gov (United States)

    Floryan, Daniel; Van Buren, Tyler; Smits, Alexander J.

    2017-08-01

    Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry (PIV) flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

  6. Targeted delivery of colloids by swimming bacteria

    Science.gov (United States)

    Koumakis, N.; Lepore, A.; Maggi, C.; Di Leonardo, R.

    2013-01-01

    The possibility of exploiting motile microorganisms as tiny propellers represents a fascinating strategy for the transport of colloidal cargoes. However, delivery on target sites usually requires external control fields to steer propellers and trigger cargo release. The need for a constant feedback mechanism prevents the design of compact devices where biopropellers could perform their tasks autonomously. Here we show that properly designed three-dimensional (3D) microstructures can define accumulation areas where bacteria spontaneously and efficiently store colloidal beads. The process is stochastic in nature and results from the rectifying action of an asymmetric energy landscape over the fluctuating forces arising from collisions with swimming bacteria. As a result, the concentration of colloids over target areas can be strongly increased or depleted according to the topography of the underlying structures. Besides the significance to technological applications, our experiments pose some important questions regarding the structure of stationary probability distributions in non-equilibrium systems. PMID:24100868

  7. Strategies for chemically healthy public swimming pools

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht

    spreading of pathogens between swimmers because of its residual disinfection effect. In addition to potential contamination of pathogenic microorganisms, swimming pool water is polluted by organic matter deposited from the bathers such as saliva, urine, sweat, hair and personal care products. Since chlorine...... avoided. Hair and skin cells are precursors for DBPs so good filtration with fast removal of particles could also be an option to obtain lower DBPs formation. Another way to remove precursors is to ozonate the pool water, since ozonation of the precursors leads to organic compound which is less reactive...... affected the investigated groups of DBPs differently. An analogue consisting of the main component in urine and sweat and particles consisting of skin cells and hair were used as precursor material and in both cases the formation of THMs decreased with decreasing pH while HAN formation increased...

  8. Chronic Rhodiola rosea extract supplementation enforces exhaustive swimming tolerance.

    Science.gov (United States)

    Lee, Fang-Tsai; Kuo, Tz-Yin; Liou, Shaw-Yih; Chien, Chiang-Ting

    2009-01-01

    We explored the effects and mechanisms of Rhodiola rosea extract supplementation on swimming-induced fatigue in rats. The concentrations of active components in Rhodiola rosea have been determined by high performance liquid chromatography-mass spectrometer. The Rhodiola rosea extract supplementation in water for 2-4 weeks was evaluated in male Wistar rats with 90-min unloaded swimming exercise and 5% body weight loaded swimming up to fatigue. We measured the fatigue biomarkers, including blood urea nitrogen (BUN), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), hepatic glycogen content, the activity of fat metabolism enzymes, sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FAS), the tissue oxygen content and ratio of red and white skeletal muscle fibers in rats. Rhodiola rosea significantly increased liver glycogen, SREBP-1, FAS, heat shock protein 70 expression, Bcl-2/Bax ratio and oxygen content before swimming. Rhodiola rosea supplementation significantly increased the swimming time in a dose-dependent manner and reduced swimming-enhanced serum BUN, GOT and GPT levels. The ratio of red and white muscle fibers was not altered after chronic Rhodiola rosea extract supplementation. Chronic Rhodiola rosea supplementation significantly improved exhaustive swimming-induced fatigue by the increased glycogen content, energy supply of lipogenic enzyme expressions and protective defense mechanisms.

  9. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  10. Health impact of disinfection by-products in swimming pools

    Directory of Open Access Journals (Sweden)

    Cristina M. Villanueva

    2012-12-01

    Full Text Available This article is focused on the epidemiological evidence on the health impacts related to disinfection by-products (DBPs in swimming pools, which is a chemical hazard generated as an undesired consequence to reduce the microbial pathogens. Specific DBPs are carcinogenic, fetotoxic and/or irritant to the airways according to experimental studies. Epidemiological evidence shows that swimming in pools during pregnancy is not associated with an increased risk of reproductive outcomes. An epidemiological study suggested an increased risk of bladder cancer with swimming pool attendance, although evidence is inconclusive. A higher prevalence of respiratory symptoms including asthma is found among swimming pool workers and elite swimmers, although the causality of this association is unclear. The body of evidence in children indicates that asthma is not increased by swimming pool attendance. Overall, the available knowledge suggests that the health benefits of swimming outweigh the potential health risks of chemical contamination. However, the positive effects of swimming should be enhanced by minimising potential risks.

  11. CREATINE SUPPLEMENTATION AND SWIM PERFORMANCE: A BRIEF REVIEW

    Directory of Open Access Journals (Sweden)

    Melissa J. Hopwood

    2006-03-01

    Full Text Available Nutritional supplements are popular among athletes participating in a wide variety of sports. Creatine is one of the most commonly used dietary supplements, as it has been shown to be beneficial in improving performance during repeated bouts of high-intensity anaerobic activity. This review examines the specific effects of creatine supplementation on swimming performance, and considers the effects of creatine supplementation on various measures of power development in this population. Research performed on the effect of creatine supplementation on swimming performance indicates that whilst creatine supplementation is ineffective in improving performance during a single sprint swim, dietary creatine supplementation may benefit repeated interval swim set performance. Considering the relationship between sprint swimming performance and measurements of power, the effect of creatine supplementation on power development in swimmers has also been examined. When measured on a swim bench ergometer, power development does show some improvement following a creatine supplementation regime. How this improvement in power output transfers to performance in the pool is uncertain. Although some evidence exists to suggest a gender effect on the performance improvements seen in swimmers following creatine supplementation, the majority of research indicates that male and female swimmers respond equally to supplementation. A major limitation to previous research is the lack of consideration given to the possible stroke dependant effect of creatine supplementation on swimming performance. The majority of the research conducted to date has involved examination of the freestyle swimming stroke only. The potential for performance improvements in the breaststroke and butterfly swimming strokes is discussed, with regards to the biomechanical differences and differences in efficiency between these strokes and freestyle

  12. Declines in swimming performance with age: a longitudinal study of Masters swimming champions

    Directory of Open Access Journals (Sweden)

    Rubin RT

    2013-03-01

    Full Text Available Robert T Rubin,1,2 Sonia Lin,3 Amy Curtis,4 Daniel Auerbach,5 Charlene Win6 1Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; 2UCLA Bruin Masters Swim Club, Los Angeles, CA, USA; 3Saint Louis University School of Medicine, Saint Louis, MO, USA; 4Indiana University School of Medicine, Indianapolis, IN, USA; 5University of California, Berkeley, CA, USA; 6Loyola Marymount University, Los Angeles, CA, USA Introduction: Because of its many participants and thorough records, competitive Masters swimming offers a rich data source for determining the rate of physical decline associated with aging in physically fit individuals. The decline in performance among national champion swimmers, both men and women and in short and long swims, is linear, at about 0.6% per year up to age 70–75, after which it accelerates in quadratic fashion. These conclusions are based primarily on cross-sectional studies, and little is known about individual performance declines with aging. Herein we present performance profiles of 19 male and 26 female national and international champion Masters swimmers, ages 25 to 96 years, participating in competitions for an average of 23 years. Methods and results: Swimmers’ longitudinal data were compared with the fastest times of world record holders across ages 35–100 years by two regression methods. Neither method proved to accurately model this data set: compared with the rates of decline estimated from the world record data, which represent the best recorded times at given ages, there was bias toward shallower rates of performance decline in the longitudinal data, likely owing to a practice effect in some swimmers as they began their Masters programs. In swimmers’ later years, once maximum performance had been achieved, individual profiles followed the decline represented in the world records, and a few swimmers became the world record holders. In some instances

  13. Optimal translational swimming of a sphere at low Reynolds number

    CERN Document Server

    Felderhof, B U

    2015-01-01

    Swimming velocity and rate of dissipation of a sphere with surface distortions are discussed on the basis of the Stokes equations of low Reynolds number hydrodynamics. At first the surface distortions are assumed to cause an irrotational axisymmetric flow pattern. The efficiency of swimming is optimized within this class of flows. Subsequently more general axisymmetric polar flows with vorticity are considered. This leads to a considerably higher maximum efficiency. An additional measure of swimming performance is proposed based on the energy consumption for given amplitude of stroke.

  14. An introduction to the hydrodynamics of swimming microorganisms

    Science.gov (United States)

    Yeomans, J. M.; Pushkin, D. O.; Shum, H.

    2014-09-01

    This manuscript is a summary of a set of lectures given at the Geilo School 2013 Soft Matter Confinement: from Biology to Physics. It aims to provide an introduction to the hydrodynamics that underlies the way in which microorganisms, such as bacteria and algae, and fabricated microswimmers, swim. We focus on two features peculiar to bacterial swimming: the Scallop theorem and the dipolar nature of the far flow field. We discuss the consequences of these to the velocity field of a swimmer suspension and to the motion of passive tracers as a bacterium swims past.

  15. [The striatum and the organization of forced swimming in rats].

    Science.gov (United States)

    Batrurin, V A; Shchetinin, E V; Arushanian, E B; Manzhikova, G I

    1989-01-01

    Prolonged repeated electric stimulation of rats striatum causes stable behavioural depression and reorganization of temporal dynamics of forced swimming. Simultaneously increases the depression index offered by us as ratio of the number of immobilization cycles shorter than 6 s to the total number of active swimming cycles. Striatectomy and amphetamine administration (1 mg/kg) uniformly change the rhythmic structure of swimming with an increase of animals general motor activity without change of the depression index. It is suggested to use striatal inactivation as a model of depression state.

  16. Energy conservation in outdoor swimming pools. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Roskam, F.

    1987-11-01

    Part two of the report discusses the energy characteristics of three more BMFT/EC-supported demonstration plants (outdoor and indoor swimming pools) intended to investigate into low-cost energy supplies. Photographs, schematic sketches, tables, and figures facilitate access to the solar systems (collector surfaces, heat exchangers, water supply), the coverings (plastic foils), heat recovery systems recovering heat from the outgoing air (indoor swimming pools) and from filter backwash water as well as to other important aspects (swimming pool structures, site selection, climatic conditions). Water treatment and water heating systems are shown in a function diagram. (HWJ).

  17. 36 CFR 3.17 - What regulations apply to swimming areas and beaches?

    Science.gov (United States)

    2010-07-01

    ... swimming areas and beaches? 3.17 Section 3.17 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.17 What regulations apply to swimming areas and beaches? (a) The superintendent may designate areas as swimming areas or swimming beaches in...

  18. Survival and swimming behavior of insecticide-exposed larvae and pupae of the yellow fever mosquito Aedes aegypti.

    Science.gov (United States)

    Tomé, Hudson Vv; Pascini, Tales V; Dângelo, Rômulo Ac; Guedes, Raul Nc; Martins, Gustavo F

    2014-04-24

    The yellow fever mosquito Aedes aegypti is essentially a container-inhabiting species that is closely associated with urban areas. This species is a vector of human pathogens, including dengue and yellow fever viruses, and its control is of paramount importance for disease prevention. Insecticide use against mosquito juvenile stages (i.e. larvae and pupae) is growing in importance, particularly due to the ever-growing problems of resistance to adult-targeted insecticides and human safety concerns regarding such use in human dwellings. However, insecticide effects on insects in general and mosquitoes in particular primarily focus on their lethal effects. Thus, sublethal effects of such compounds in mosquito juveniles may have important effects on their environmental prevalence. In this study, we assessed the survival and swimming behavior of A. aegypti 4th instar larvae (L4) and pupae exposed to increasing concentrations of insecticides. We also assessed cell death in the neuromuscular system of juveniles. Third instar larvae of A. aegypti were exposed to different concentrations of azadirachtin, deltamethrin, imidacloprid and spinosad. Insect survival was assessed for 10 days. The distance swam, the resting time and the time spent in slow swimming were assessed in 4th instar larvae (L4) and pupae. Muscular and nervous cells of L4 and pupae exposed to insecticides were marked with the TUNEL reaction. The results from the survival bioassays were subjected to survival analysis while the swimming behavioral data were subjected to analyses of covariance, complemented with a regression analysis. All insecticides exhibited concentration-dependent effects on survival of larvae and pupae of the yellow fever mosquito. The pyrethroid deltamethrin was the most toxic insecticide followed by spinosad, imidacloprid, and azadirachtin, which exhibited low potency against the juveniles. All insecticides except azadirachtin reduced L4 swimming speed and wriggling movements. A

  19. Survival and swimming behavior of insecticide-exposed larvae and pupae of the yellow fever mosquito Aedes aegypti

    Science.gov (United States)

    2014-01-01

    Background The yellow fever mosquito Aedes aegypti is essentially a container-inhabiting species that is closely associated with urban areas. This species is a vector of human pathogens, including dengue and yellow fever viruses, and its control is of paramount importance for disease prevention. Insecticide use against mosquito juvenile stages (i.e. larvae and pupae) is growing in importance, particularly due to the ever-growing problems of resistance to adult-targeted insecticides and human safety concerns regarding such use in human dwellings. However, insecticide effects on insects in general and mosquitoes in particular primarily focus on their lethal effects. Thus, sublethal effects of such compounds in mosquito juveniles may have important effects on their environmental prevalence. In this study, we assessed the survival and swimming behavior of A. aegypti 4th instar larvae (L4) and pupae exposed to increasing concentrations of insecticides. We also assessed cell death in the neuromuscular system of juveniles. Methods Third instar larvae of A. aegypti were exposed to different concentrations of azadirachtin, deltamethrin, imidacloprid and spinosad. Insect survival was assessed for 10 days. The distance swam, the resting time and the time spent in slow swimming were assessed in 4th instar larvae (L4) and pupae. Muscular and nervous cells of L4 and pupae exposed to insecticides were marked with the TUNEL reaction. The results from the survival bioassays were subjected to survival analysis while the swimming behavioral data were subjected to analyses of covariance, complemented with a regression analysis. Results All insecticides exhibited concentration-dependent effects on survival of larvae and pupae of the yellow fever mosquito. The pyrethroid deltamethrin was the most toxic insecticide followed by spinosad, imidacloprid, and azadirachtin, which exhibited low potency against the juveniles. All insecticides except azadirachtin reduced L4 swimming speed and

  20. Swimming with predators and pesticides: how environmental stressors affect the thermal physiology of tadpoles.

    Science.gov (United States)

    Katzenberger, Marco; Hammond, John; Duarte, Helder; Tejedo, Miguel; Calabuig, Cecilia; Relyea, Rick A

    2014-01-01

    To forecast biological responses to changing environments, we need to understand how a species's physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4°C higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5°C, while exposure to the herbicide marginally lowered Topt by 0.4°C. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5°C higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.