WorldWideScience

Sample records for short distance swimming

  1. 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. ...

  2. EFFECTS OF DISTANCE SPECIALIZATION ON THE BACKSTROKE SWIMMING KINEMATICS

    Directory of Open Access Journals (Sweden)

    Cortesi Matteo

    2012-09-01

    Full Text Available The purpose of the present study was to investigate different biomechanical variables of backstroke technique in swimmers specialized in different distance events, in order to investigate the capacity to modify the timing of the arm stroke when changing the swimming velocity from sub-maximal to maximal. Two 25-m backstroke trials respectively at 70% of maximum velocity (V70 and at 100% of maximum velocity (Vmax were performed by 9 200-m distance swimmers and 9 50-m distance swimmers. Swimming velocity, stroke length, stroke rate, duration of different phases of the arm stroke and selected kinematic variables were assessed in both cases. In the 50-m distance swimmers, the duration of the propulsive phase at Vmax, expressed as a percentage of the duration of the total underwater arm stroke, increased significantly (p = 0.001 with increasing swimming velocity. Specifically, both the pull and push phases were fundamental in the increase of duration of the propulsive phase. When compared to 200-m specialists, 50-m distance swimmers seem to be more able to modify their arm stroke phases duration when increasing the swimming velocity in backstroke

  3. Energy cost of swimming of elite long-distance swimmers.

    Science.gov (United States)

    Zamparo, P; Bonifazi, M; Faina, M; Milan, A; Sardella, F; Schena, F; Capelli, C

    2005-08-01

    The aim of this study was: (1) to assess the energy cost of swimming (C(s), kJ km(-1)) in a group of male (n = 5) and female (n = 5) elite swimmers specialised in long-distance competitions; (2) to evaluate the possible effect of a 2-km trial on the absolute value of C(s). C(s) was assessed during three consecutive 400-m trials covered in a 50-m pool at increasing speeds (v1, v2, v3). After these experiments the subjects swam a 2-km trial at the 10-km race speed (v2km) after which the three 400-m trials were repeated at the same speed as before (v5 = v1, v6 = v2, v7 = v3). C(s) was calculated by dividing the net oxygen uptake at steady state VO2ss by the corresponding average speed (v, m s(-1)). VO2ss was estimated by using back extrapolation technique from breath-to-breath VO2 recorded during the first 30 s of recovery after each test. C(s) increased (from 0.69 kJ m(-1) to 1.27 kJ m(-1)) as a function of v (from 1.29 m s(-1) to 1.50 m s(-1)), its values being comparable to those measured in elite short distance swimmers at similar speeds. In both groups of subjects the speed maintained during the 2-km trial (v2km) was on the average only 1.2% faster than of v2 and v6 (P>0.05), whereas C(s) assessed at the end of the 2-km trial (v2km) turned out to be 21 +/- 26% larger than that assessed at v2 and v6 (P<0.05); the average stroke frequency (SF, cycles min(-1)) during the 2-km trial turned to be about 6% (P<0.05) faster than that assessed at v2 and v6. At v5, C(s) turned out to be 19 +/- 9% (P<0.05) and 22 +/- 27% (0.1 < P = 0.05) larger than at v1 in male and female subjects (respectively). SF was significantly faster (P<0.05, in male subjects) and the distance per stroke (Ds = v/SF) significantly shorter (P<0.05) in female subjects at v5 and v6 than at v1 and v2. These data suggest that the increase of C(s) found after the 2-km trial was likely related to a decrease in propelling efficiency, since the latter is related to the distance per stroke.

  4. 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...... 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...

  5. Three short distance structures from quantum algebras

    International Nuclear Information System (INIS)

    Kempf, A.

    1997-01-01

    Known results are reviewed and new results are given on three types of short distance structures of observables which typically appear in studies of quantum group related algebras. In particular, one of the short distance structures is shown to suggest a new mechanism for the introduction of internal symmetries

  6. Physiological characteristics of elite short- and long-distance triathletes.

    Science.gov (United States)

    Millet, Grégoire P; Dréano, Patrick; Bentley, David J

    2003-01-01

    The purpose of this study was to compare the physiological responses in cycling and running of elite short-distance (ShD) and long-distance (LD) triathletes. Fifteen elite male triathletes participating in the World Championships were divided into two groups (ShD and LD) and performed a laboratory trial that comprised submaximal treadmill running, maximal then submaximal ergometry cycling and then an additional submaximal run. "In situ" best ShD triathlon performances were also analysed for each athlete. ShD demonstrated a significantly faster swim time than LD whereas .VO(2max) (ml kg(-1) min(-1)), cycling economy (W l(-1) min(-1)), peak power output (.W(peak),W) and ventilatory threshold (%.VO(2max)) were all similar between ShD and LD. Moreover, there were no differences between the two groups in the change (%) in running economy from the first to the second running bout. Swimming time was correlated to .W(peak)(r=-0.76; Ptriathlon was correlated to .W(peak)(r=-0.83; P<0.05) in LD. In conclusion, ShD triathletes had a faster swimming time but did not exhibit different maximal or submaximal physiological characteristics measured in cycling and running than LD triathletes.

  7. Short-distance structure of instantons

    International Nuclear Information System (INIS)

    Carlitz, R.D.; Creamer, D.B.

    The short distance structure of a quark propagator in an instanton background field is analyzed. This analysis describes the influence of instantons upon physical processes such as electron-position annihilation and the deep inelastic scattering of leptons from hadrons

  8. A Novel Method for Short Distance Measurements

    International Nuclear Information System (INIS)

    Fernandez, M.G.; Ferrando, A.; Josa, M.I.; Molinero, A.; Oller, J.C.; Arce, P.; Calvo, E.; Figueroa, C.F.; Garcia, C.F.; Rodigrido, T.; Vila, I.; Virto, A.L.

    1998-01-01

    A new, accurate and un expensive device for measuring short distances, intended for monitoring in LHC experiments is presented. Data taken with a very simple prototype are shown and performance is extracted. (Author) 4 refs

  9. Operator expansion at short distance in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Hubschmid, W [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik; Mallik, S [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik

    1982-11-01

    We present a method of calculating coefficients of gluon operators in the operator product expansion of two-point functions at short distance. It is based on a short-distance expansion of the singular part of the quark propagator in the gluon field, the latter being treated as external. We verify in full generality that the spin zero, gluon operator of dimension six does not contribute to the two-point functions of quark bilinears.

  10. Regional variation in short distance homogamy

    OpenAIRE

    Haandrikman, Karen; van Wissen, Leo

    2011-01-01

    A third of all Dutch cohabiters choose a partner from the same municipality, so-called short distance homogamy. This article analyses the regional variation in this phenomenon, and it explains this variation in terms of geographical, socioeconomic, demographic and cultural determinants. Population register data on all new cohabiters in 2004 were used. Regression methods were employed to explain spatial patterns. Regional variation in short distance homogamy is largely explained by geographica...

  11. 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.

  12. Regional variation in short distance homogamy

    NARCIS (Netherlands)

    Haandrikman, K.; van Wissen, L.J.G.

    2011-01-01

    A third of all Dutch cohabiters choose a partner from the same municipality, so-called short distance homogamy. This article analyses the regional variation in this phenomenon, and it explains this variation in terms of geographical, socioeconomic, demographic and cultural determinants. Population

  13. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water

    Science.gov (United States)

    2014-01-01

    Polar bears (Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004-2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.

  14. Analysis of speed, stroke rate, and stroke distance for world-class breaststroke swimming.

    Science.gov (United States)

    Garland Fritzdorf, Stephen; Hibbs, Angela; Kleshnev, Valery

    2009-02-15

    Speed in aquatic locomotion is determined by stroke distance and stroke rate, but it does not always follow that an increase in stroke rate will lead to an increase in speed. Kleshnev (2006) developed a method to evaluate the relationship between speed and stroke rate during rowing - the effective work per stroke. In this case study, the effective work per stroke was determined for a male world-class 100-m breaststroke swimmer for seven races in major championships and compared between: each of the seven races; each quarter within each race; and the best swims of this case study and seven other world-class swimmers. The effective work per stroke was related to race performance, with the fastest race having the highest effective work per stroke and lowest stroke rate, with slower races having low effectiveness and high stroke rate (R(2) = 0.85). The effective work per stroke was reduced in a race as the swimmer fatigued. The within-race standard deviation of effectiveness was lower in fast swims (R(2) = 0.84). This analysis has identified some characteristics of fast swimming: high effectiveness, optimal stroke rate, and a flat effectiveness profile. Training and racing strategies can now be devised to improve performance by increasing the sensitivity of assessment of strengths and weaknesses in individuals.

  15. Short-Term Changes in Respiratory Biomarkers after Swimming in a Chlorinated Pool

    OpenAIRE

    Font-Ribera, Laia; Kogevinas, Manolis; Zock, Jan-Paul; G?mez, Federico P.; Barreiro, Esther; Nieuwenhuijsen, Mark J.; Fernandez, Pilar; Lourencetti, Carolina; P?rez-Olabarr?a, Maitane; Bustamante, Mariona; Marcos, Ricard; Grimalt, Joan O.; Villanueva, Cristina M.

    2010-01-01

    Background Swimming in chlorinated pools involves exposure to disinfection by-products (DBPs) and has been associated with impaired respiratory health. Objectives We evaluated short-term changes in several respiratory biomarkers to explore mechanisms of potential lung damage related to swimming pool exposure. Methods We measured lung function and biomarkers of airway inflammation [fractional exhaled nitric oxide (FeNO), eight cytokines, and vascular endothelial growth factor (VEGF) in exhaled...

  16. Technical and tactical action modeling of highly trained athletes specializing in breaststroke swimming at various length distances

    Directory of Open Access Journals (Sweden)

    Olga Pilipko

    2017-08-01

    Full Text Available Purpose: definition of model parameters of technical and tactical actions of highly trained athletes specializing in breaststroke swimming at various length distances. Material & Methods: analysis of literary sources, video shooting, timing, methods of mathematical data processing. The contingent of the surveyed was made up of athletes who specialized in distances of 50, 100 and 200 meters in breaststroke swimming and had the level of sports qualification of master of sports of Ukraine, Master of Sports of International grade. Result: authors found that the technical and tactical actions of highly trained athletes during the swim of distances of 50, 100 and 200 meters by the breaststroke have their own characteristics; degree of influence of speed, pace and "step" of the strokes cycle on the result of swim distances of 50, 100 and 200 meters is determined; developed their model characteristics. Conclusion: the definition of distance specialization in breaststroke swimming should be carried out taking into account the compliance of individual indicators of technical and tactical actions of athletes to model parameters.

  17. Age and gender interactions in short distance triathlon performance.

    Science.gov (United States)

    Etter, Franziska; Knechtle, Beat; Bukowski, Arkadiusz; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2013-01-01

    This study investigated the participation and performance trends as well as the age and gender interaction at the Olympic distance 'Zürich Triathlon' (1.5 km swim, 40 km cycle and 10 km run) from 2000 to 2010 in 7,939 total finishers (1,666 females and 6,273 males). Female triathletes aged from 40 to 54 years significantly (P distance triathlon performance increased after the age of 35 years, which appeared earlier compared to long distance triathlon as suggested by previous studies. Future investigations should compare gender difference in performance for different endurance events across age to confirm a possible effect of exercise duration on gender difference with advancing age.

  18. Effects of Short-Interval and Long-Interval Swimming Protocols on Performance, Aerobic Adaptations, and Technical Parameters: A Training Study.

    Science.gov (United States)

    Dalamitros, Athanasios A; Zafeiridis, Andreas S; Toubekis, Argyris G; Tsalis, George A; Pelarigo, Jailton G; Manou, Vasiliki; Kellis, Spiridon

    2016-10-01

    Dalamitros, AA, Zafeiridis, AS, Toubekis, AG, Tsalis, GA, Pelarigo, JG, Manou, V, and Kellis, S. Effects of short-interval and long-interval swimming protocols on performance, aerobic adaptations, and technical parameters: A training study. J Strength Cond Res 30(10): 2871-2879, 2016-This study compared 2-interval swimming training programs of different work interval durations, matched for total distance and exercise intensity, on swimming performance, aerobic adaptations, and technical parameters. Twenty-four former swimmers were equally divided to short-interval training group (INT50, 12-16 × 50 m with 15 seconds rest), long-interval training group (INT100, 6-8 × 100 m with 30 seconds rest), and a control group (CON). The 2 experimental groups followed the specified swimming training program for 8 weeks. Before and after training, swimming performance, technical parameters, and indices of aerobic adaptations were assessed. ΙΝΤ50 and ΙΝΤ100 improved swimming performance in 100 and 400-m tests and the maximal aerobic speed (p ≤ 0.05); the performance in the 50-m swim did not change. Posttraining V[Combining Dot Above]O2max values were higher compared with pretraining values in both training groups (p ≤ 0.05), whereas peak aerobic power output increased only in INT100 (p ≤ 0.05). The 1-minute heart rate and blood lactate recovery values decreased after training in both groups (p training in both groups (p ≤ 0.05); no changes were observed in stroke rate after training. Comparisons between groups on posttraining mean values, after adjusting for pretraining values, revealed no significant differences between ΙΝΤ50 and ΙΝΤ100 for all variables; however, all measures were improved vs. the respective values in the CON (p training.

  19. Spin physics and inclusive processes at short distances

    International Nuclear Information System (INIS)

    Craigie, N.S.

    1982-10-01

    The following aspects of spin physics at short distances are studied: 1. the factorization theorem in perturbative QCD and helicity asymmetries in inclusive processes, 2. the effect of higher order radiative corrections on helicity asymmetries, 3. the higher order power mechanism and spin asymmetries, 4. difficulties in understanding transverse spin in perturbative QCD, 5. helicity asymmetries of short distances as a means of recognizing supersymmetric interactions. Experiments are suggested for the verification of theoretical conclusions. Although spin-physics at short distances is difficult to demonstrate experimentally it may provide a valuable tool to show how perturbative QCD operates in the presence of the non-perturbative hadronic structure. It may also prove valuable to show new interactions which might occur at very short distances

  20. On the short distance behavior of string theories

    International Nuclear Information System (INIS)

    Guida, R.; Konishi, K.; Provero, P.

    1991-01-01

    Short distance behavior of string theories is investigated by the use of the discretized path-integral formulation. In particular, the minimum physical length and the generalized uncertainty relation are re-derived from a set of Ward-Takahashi identities. In this paper several issues related to the form of the generalized uncertainty relation and to its implications are discussed. A consistent qualitative picture of short distance behavior of string theory seems to emerge from such a study

  1. Short distance line of sight laser communication

    International Nuclear Information System (INIS)

    Mudassar, A.A.; Hussain, H.; Jamil-ur-Rehman

    1998-01-01

    Communication methods based on lasers as carrier are well known. In our work we have made a two way laser based communication system for short range (<2 Km) line of sight communication. A small piece of plane mirror (100% reflector) was mounted on the centre of a speaker cone. The speaker was positioned close to the opening of laser such that He-Ne laser beam (10 mW) after reflection from the mirror is directed towards the receiver. There is a pre-amplifier and an amplifier between a microphone and the speaker. When the diagram of the speaker vibrates, it positionally modulates the laser beam. On the receiving end, there is a photo diode, a pre-amplifier, an amplifier and a head phone. So the man on the receiving end can decode the sound signal. On each stage there is a transmitter and a receiver assembled close to each other. So the two way communication is possible in the range 20 to 20 Khz. (author)

  2. Latent lifestyle and mode choice decisions when travelling short distances

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Halldórsdóttir, Katrín; Nielsen, Otto Anker

    2016-01-01

    In the quest for sustainable travel, short distances appear the most amenable to curbing the use of the automobile. Existing studies about short trips evaluate the potential of shifting from the automobile to sustainable travel options while considering the population as homogeneous in its prefer...

  3. Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod.

    Science.gov (United States)

    Michalec, François-Gaël; Holzner, Markus; Barras, Alexandre; Lacoste, Anne-Sophie; Brunet, Loïc; Lee, Jae-Seong; Slomianny, Christian; Boukherroub, Rabah; Souissi, Sami

    2017-09-01

    Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod Eurytemora affinis. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 μg L -1 ) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment

  4. Short-term changes in respiratory biomarkers after swimming in a chlorinated pool.

    Science.gov (United States)

    Font-Ribera, Laia; Kogevinas, Manolis; Zock, Jan-Paul; Gómez, Federico P; Barreiro, Esther; Nieuwenhuijsen, Mark J; Fernandez, Pilar; Lourencetti, Carolina; Pérez-Olabarría, Maitane; Bustamante, Mariona; Marcos, Ricard; Grimalt, Joan O; Villanueva, Cristina M

    2010-11-01

    Swimming in chlorinated pools involves exposure to disinfection by-products (DBPs) and has been associated with impaired respiratory health. We evaluated short-term changes in several respiratory biomarkers to explore mechanisms of potential lung damage related to swimming pool exposure. We measured lung function and biomarkers of airway inflammation [fractional exhaled nitric oxide (FeNO), eight cytokines, and vascular endothelial growth factor (VEGF) in exhaled breath condensate], oxidative stress (8-isoprostane in exhaled breath condensate), and lung permeability [surfactant protein D (SP-D) and the Clara cell secretory protein (CC16) in serum] in 48 healthy nonsmoking adults before and after they swam for 40 min in a chlorinated indoor swimming pool. We measured trihalomethanes in exhaled breath as a marker of individual exposure to DBPs. Energy expenditure during swimming, atopy, and CC16 genotype (rs3741240) were also determined. Median serum CC16 levels increased from 6.01 to 6.21 microg/L (average increase, 3.3%; paired Wilcoxon test p = 0.03), regardless of atopic status and CC16 genotype. This increase was explained both by energy expenditure and different markers of DBP exposure in multivariate models. FeNO was unchanged overall but tended to decrease among atopics. We found no significant changes in lung function, SP-D, 8-isoprostane, eight cytokines, or VEGF. We detected a slight increase in serum CC16, a marker of lung epithelium permeability, in healthy adults after they swam in an indoor chlorinated pool. Exercise and DBP exposure explained this association, without involving inflammatory mechanisms. Further research is needed to confirm the results, establish the clinical relevance of short-term serum CC16 changes, and evaluate the long-term health impacts.

  5. Consequences of long-distance swimming and travel over deep-water pack ice for a female polar bear during a year of extreme sea ice retreat

    Science.gov (United States)

    Durner, George M.; Whiteman, J.P.; Harlow, H.J.; Amstrup, Steven C.; Regehr, E.V.; Ben-David, M.

    2011-01-01

    Polar bears (Ursus maritimus) prefer to live on Arctic sea ice but may swim between ice floes or between sea ice and land. Although anecdotal observations suggest that polar bears are capable of swimming long distances, no data have been available to describe in detail long distance swimming events or the physiological and reproductive consequences of such behavior. Between an initial capture in late August and a recapture in late October 2008, a radio-collared adult female polar bear in the Beaufort Sea made a continuous swim of 687 km over 9 days and then intermittently swam and walked on the sea ice surface an additional 1,800 km. Measures of movement rate, hourly activity, and subcutaneous and external temperature revealed distinct profiles of swimming and walking. Between captures, this polar bear lost 22% of her body mass and her yearling cub. The extraordinary long distance swimming ability of polar bears, which we confirm here, may help them cope with reduced Arctic sea ice. Our observation, however, indicates that long distance swimming in Arctic waters, and travel over deep water pack ice, may result in high energetic costs and compromise reproductive fitness.

  6. Going the distance: Service delivery for the Danish National swimming team during the Olympics

    DEFF Research Database (Denmark)

    Larsen, Carsten Hvid

    In this presentation I will outline the service delivery for the Danish National swimming team and provide an example of my work based on mindfulness and acceptance and commitment therapy (ACT) with an individual swimmer during the Olympics. Being part of the Olympics involves a range of stressors...... and distractions such as a tight packed swimming schedule (up to 12 starts across seven days), a lot of media attention, social media, others and own expectations. In my service delivery during the Olympics I tried to create an awareness of these stressors and distractions. On a normal day at the Olympics I had...

  7. Swimming activity in marine fish.

    Science.gov (United States)

    Wardle, C S

    1985-01-01

    Marine fish are capable of swimming long distances in annual migrations; they are also capable of high-speed dashes of short duration, and they can occupy small home territories for long periods with little activity. There is a large effect of fish size on the distance fish migrate at slow swimming speeds. When chased by a fishing trawl the effect of fish size on swimming performance can decide their fate. The identity and thickness of muscle used at each speed and evidence for the timing of myotomes used during the body movement cycle can be detected using electromyogram (EMG) electrodes. The cross-sectional area of muscle needed to maintain different swimming speeds can be predicted by relating the swimming drag force to the muscle force. At maximum swimming speed one completed cycle of swimming force is derived in sequence from the whole cross-sectional area of the muscles along the two sides of the fish. This and other aspects of the swimming cycle suggest that each myotome might be responsible for generating forces involved in particular stages of the tail sweep. The thick myotomes at the head end shorten during the peak thrust of the tail blade whereas the thinner myotomes nearer the tail generate stiffness appropriate for transmission of these forces and reposition the tail for the next cycle.

  8. Short distance modification of the quantum virial theorem

    Science.gov (United States)

    Zhao, Qin; Faizal, Mir; Zaz, Zaid

    2017-07-01

    In this letter, we will analyse the deformation of a semi-classical gravitational system from minimal measurable length scale. In the semi-classical approximation, the gravitational field will be analysed as a classical field, and the matter fields will be treated quantum mechanically. Thus, using this approximation, this system will be represented by a deformation of Schrödinger-Newton equation by the generalised uncertainty principle (GUP). We will analyse the effects of this GUP deformed Schrödinger-Newton equation on the behaviour of such a semi-classical gravitational system. As the quantum mechanical virial theorem can be obtained using the Schrödinger-Newton equation, a short distance modification of the Schrödinger-Newton equation will also result in a short distance modification of the quantum mechanical virial theorem.

  9. Short-distance perturbation theory for the leading logarithm models

    International Nuclear Information System (INIS)

    Adler, S.L.

    1983-01-01

    I derive a short-distance perturbation expansion for the static potential of quasi-abelian quark and antiquark source charges, in the models in which renormalization group radiative corrections are retained in the gauge gluon effective dielectric functional. A natural running coupling parameter zeta for the models is identified, and the scale mass #betta#sub(p) appearing in zeta is computed by requiring the vanishing of the O(zeta 2 ) term in the perturbation expansions. The models are shown to give unsatisfactory results beyond one-loop order in the short-distance expansion, as a result of the breakdown in the ultraviolet of the assumption that the effective action is a local functional of the field strength. The same argument indicates that the assumption of a local effective action becomes self-consistent in the large-distance limit. The coupling parameter zeta is identified as a running coupling which evolves in field strength, rather than momentum, and which becomes infinite in the large-distance limit. (orig.)

  10. Scattering and short-distance properties in field theory models

    International Nuclear Information System (INIS)

    Iagolnitzer, D.

    1987-01-01

    The aim of constructive field theory is not only to define models but also to establish their general properties of physical interest. We here review recent works on scattering and on short-distance properties for weakly coupled theories with mass gap such as typically P(φ) in dimension 2, φ 4 in dimension 3 and the (renormalizable, asymptotically free) massive Gross-Neveu (GN) model in dimension 2. Many of the ideas would apply similarly to other (possibly non renormalizable) theories that might be defined in a similar way via phase-space analysis

  11. A short working distance multiple crystal x-ray spectrometer

    Science.gov (United States)

    Dickinson, B.; Seidler, G.T.; Webb, Z.W.; Bradley, J.A.; Nagle, K.P.; Heald, S.M.; Gordon, R.A.; Chou, I.-Ming

    2008-01-01

    For x-ray spot sizes of a few tens of microns or smaller, a millimeter-sized flat analyzer crystal placed ???1 cm from the sample will exhibit high energy resolution while subtending a collection solid angle comparable to that of a typical spherically bent crystal analyzer (SBCA) at much larger working distances. Based on this observation and a nonfocusing geometry for the analyzer optic, we have constructed and tested a short working distance (SWD) multicrystal x-ray spectrometer. This prototype instrument has a maximum effective collection solid angle of 0.14 sr, comparable to that of 17 SBCA at 1 m working distance. We find good agreement with prior work for measurements of the Mn K?? x-ray emission and resonant inelastic x-ray scattering for MnO, and also for measurements of the x-ray absorption near-edge structure for Dy metal using L??2 partial-fluorescence yield detection. We discuss future applications at third- and fourth-generation light sources. For concentrated samples, the extremely large collection angle of SWD spectrometers will permit collection of high-resolution x-ray emission spectra with a single pulse of the Linac Coherent Light Source. The range of applications of SWD spectrometers and traditional multi-SBCA instruments has some overlap, but also is significantly complementary. ?? 2008 American Institute of Physics.

  12. Short distance modifications to Newton's law in SUSY braneworld scenarios

    International Nuclear Information System (INIS)

    Palma, G.A.

    2007-10-01

    In braneworld models coming from string theory one generally encounters massless scalar degrees of freedom -moduli- parameterizing the volume of small compact extra-dimensions. Here we discuss the effects of such moduli on Newton's law for a fairly general 5-D supersymmetric braneworld scenario with a bulk scalar field φ.We show that the Newtonian potential describing the gravitational interaction between two bodies localized on the visible brane picks up a non-trivial contribution at short distances that depends on the shape of the superpotential W(φ) of the theory. In particular, we compute this contribution for dilatonic braneworld scenarios W(φ) ∝ e αφ (where a is a constant) and discuss the particular case of 5-D Heterotic M-theory. (orig.)

  13. Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms

    Directory of Open Access Journals (Sweden)

    Christopher A. Loebach

    2018-03-01

    were dropped on furs and rotated as before, then the furs were agitated for one hour. The seeds retained in the fur were counted. Results For the seed dispersal experiment, the 2Dt function provided the best fit and was the most biologically meaningful. It predicted that seed density rapidly declined with distance from the point source. Mean dispersal distance was 0.52 m and 95% of seeds dispersed within 1.14 m. The epizoochory field experiment showed increased mammal activity and A. petiolata seedlings in germination trays of the MIT compared to control. Laboratory studies showed 3–26% of seeds were attached and retained by raccoon and deer fur. Retention significantly increased if either seed or fur were wet (57–98%. Discussion Without animal seed vectors, most seeds fall within a short distance of the seed source; however, long distance dispersal may be accomplished by epizoochory. Our data are consistent with A. petiolata’s widespread distribution and development of dense clusters of the species in invaded areas.

  14. Role of the Short Distance Order in Glass Reactivity

    Directory of Open Access Journals (Sweden)

    María Vallet-Regi

    2018-03-01

    Full Text Available In 2005, our group described for the first time the structural characterization at the atomic scale of bioactive glasses and the influence of the glasses’ nanostructure in their reactivity in simulated body fluids. In that study, two bioactive sol-gel glasses with composition 80%SiO2–20%CaO and 80%SiO2–17%CaO–3%P2O5 (in mol-% were characterized by High-Resolution Transmission Electron Microscopy (HRTEM. Such characterization revealed unknown features of the glasses’ structure at the local scale that allowed the understanding of their different in vitro behaviors as a consequence of the presence or absence of P2O5. Since then, the nanostructure of numerous bioactive glasses, including melt-prepared, sol-gel derived, and mesoporous glasses, was investigated by HRTEM, Nuclear Magnetic Resonance (NMR spectroscopy, Molecular Dynamics (MD simulations, and other experimental techniques. These studies have shown that although glasses are amorphous solids, a certain type of short distance order, which greatly influences the in vitro and in vivo reactivity, is always present. This paper reviews the most significant advances in the understanding of bioactive glasses that took place in the last years as a result of the growing knowledge of the glasses’ nanostructure.

  15. Role of the Short Distance Order in Glass Reactivity

    Science.gov (United States)

    2018-01-01

    In 2005, our group described for the first time the structural characterization at the atomic scale of bioactive glasses and the influence of the glasses’ nanostructure in their reactivity in simulated body fluids. In that study, two bioactive sol-gel glasses with composition 80%SiO2–20%CaO and 80%SiO2–17%CaO–3%P2O5 (in mol-%) were characterized by High-Resolution Transmission Electron Microscopy (HRTEM). Such characterization revealed unknown features of the glasses’ structure at the local scale that allowed the understanding of their different in vitro behaviors as a consequence of the presence or absence of P2O5. Since then, the nanostructure of numerous bioactive glasses, including melt-prepared, sol-gel derived, and mesoporous glasses, was investigated by HRTEM, Nuclear Magnetic Resonance (NMR) spectroscopy, Molecular Dynamics (MD) simulations, and other experimental techniques. These studies have shown that although glasses are amorphous solids, a certain type of short distance order, which greatly influences the in vitro and in vivo reactivity, is always present. This paper reviews the most significant advances in the understanding of bioactive glasses that took place in the last years as a result of the growing knowledge of the glasses’ nanostructure. PMID:29534481

  16. Modeling of morpho-functional profile of sportsmen of high qualification who specialize in swimming in way butterfly stroke at distances of various lengths.

    Directory of Open Access Journals (Sweden)

    Olga Pilipko

    2017-02-01

    Full Text Available Purpose: the development of modern morpho-functional models of sportsmen of high qualification who specialize in swimming in way butterfly stroke at distances of various lengths. Material & Methods: the analysis of scientifically-methodical literature, timekeeping, measurement of morpho-functional indicators with application of private techniques, methods of mathematical statistics. The contingent of the investigated was made by sportsmen who specialized in distances of 50, 100 and 200 meters in way butterfly stroke and had the level of sports qualification: MSU, MSIC. Results: it is established that the morpho-functional profile of the sportsmen specializing in swimming in way butterfly stroke at distances of various length has the features; model morpho-functional characteristics of sportsmen, who act in swimming in way butterfly stroke at distances of 50, 100 and 200 meters, are developed. Conclusions: the definition of compliance of individual characteristics of the sportsman to the morpho-functional status will allow choosing correctly remote specialization of the swimmer, to open his potential opportunities most fully.

  17. A Short-Range Distance Sensor with Exceptional Linearity

    Science.gov (United States)

    Simmons, Steven; Youngquist, Robert

    2013-01-01

    A sensor has been demonstrated that can measure distance over a total range of about 300 microns to an accuracy of about 0.1 nm (resolution of about 0.01 nm). This represents an exceptionally large dynamic range of operation - over 1,000,000. The sensor is optical in nature, and requires the attachment of a mirror to the object whose distance is being measured. This work resulted from actively developing a white light interferometric system to be used to measure the depths of defects in the Space Shuttle Orbiter windows. The concept was then applied to measuring distance. The concept later expanded to include spectrometer calibration. In summary, broadband (i.e., white) light is launched into a Michelson interferometer, one mirror of which is fixed and one of which is attached to the object whose distance is to be measured. The light emerging from the interferometer has traveled one of two distances: either the distance to the fixed mirror and back, or the distance to the moving mirror and back. These two light beams mix and produce an interference pattern where some wavelengths interfere constructively and some destructively. Sending this light into a spectrometer allows this interference pattern to be analyzed, yielding the net distance difference between the two paths. The unique feature of this distance sensor is its ability to measure accurately distance over a dynamic range of more than one million, the ratio of its range (about 300 microns) to its accuracy (about 0.1 nanometer). Such a large linear operating range is rare and arises here because both amplitude and phase-matching algorithms contribute to the performance. The sensor is limited by the need to attach a mirror of some kind to the object being tracked, and by the fairly small total range, but the exceptional dynamic range should make it of interest.

  18. Physiological responses at short distances from a parametric speaker

    Directory of Open Access Journals (Sweden)

    Lee Soomin

    2012-06-01

    Full Text Available Abstract In recent years, parametric speakers have been used in various circumstances. In our previous studies, we verified that the physiological burden of the sound of parametric speaker set at 2.6 m from the subjects was lower than that of the general speaker. However, nothing has yet been demonstrated about the effects of the sound of a parametric speaker at the shorter distance between parametric speakers the human body. Therefore, we studied this effect on physiological functions and task performance. Nine male subjects participated in this study. They completed three consecutive sessions: a 20-minute quiet period as a baseline, a 30-minute mental task period with general speakers or parametric speakers, and a 20-minute recovery period. We measured electrocardiogram (ECG photoplethysmogram (PTG, electroencephalogram (EEG, systolic and diastolic blood pressure. Four experiments, one with a speaker condition (general speaker and parametric speaker, the other with a distance condition (0.3 m and 1.0 m, were conducted respectively at the same time of day on separate days. To examine the effects of the speaker and distance, three-way repeated measures ANOVA (speaker factor x distance factor x time factor were conducted. In conclusion, we found that the physiological responses were not significantly different between the speaker condition and the distance condition. Meanwhile, it was shown that the physiological burdens increased with progress in time independently of speaker condition and distance condition. In summary, the effects of the parametric speaker at the 2.6 m distance were not obtained at the distance of 1 m or less.

  19. Sex Difference in Draft-Legal Ultra-Distance Events - A Comparison between Ultra-Swimming and Ultra-Cycling.

    Science.gov (United States)

    Salihu, Lejla; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat

    2016-04-30

    Recent studies reported that the sex difference in performance in ultra-endurance sports such as swimming and cycling changed over the years. However, the aspect of drafting in draft-legal ultra-endurance races has not yet been investigated. This study investigates the sex difference in ultra-swimming and ultra-cycling draft-legal races where drafting - swimming or cycling behind other participants to save energy and have more power at the end of the race to overtake them, is allowed. The change in performance of the annual best and the annual three best in an ultra-endurance swimming race (16-km 'Faros Swim Marathon') over 38 years and in a 24-h ultra-cycling race ('World Cycling Race') over 13 years were compared and analysed with respect to sex difference. Furthermore, performances of the fastest female and male finishers ever were compared. In the swimming event, the sex difference of the annual best male and female decreased non-significantly (P = 0.262) from 5.3% (1976) to 1.0% (2013). The sex gap of speed in the annual three fastest swimmers decreased significantly (P = 0.043) from 5.9 ± 1.6% (1979) to 4.7 ± 3.1% (2013). In the cycling event, the difference in cycling speed between the annual best male and female decreased significantly (P = 0.026) from 33.31% (1999) to 10.89% (2011). The sex gap of speed in the annual three fastest decreased significantly (P = 0.001) from 32.9 ± 0.6% (1999) to 16.4 ± 5.9% (2011). The fastest male swimmer ever (swimming speed 5.3 km/h, race time: 03:01:55 h:min:s) was 1.5% faster than the fastest female swimmer (swimming speed 5.2 km/h, race time: 03:04:09 h:min:s). The three fastest male swimmers ever (mean 5.27 ± 0.13 km/h) were 4.4% faster than the three fastest female swimmers (mean 5.05 ± 0.20 km/h) (P swimming and cycling, the sex difference in the annual top and annual top three swimmers and cyclists decreased (i.e. non-linearly in swimmers and linearly in cyclists) over the years. The sex difference of the

  20. On the quark-antiquark potential at short distances

    International Nuclear Information System (INIS)

    Altevogt, P.

    1994-12-01

    We investigate the static quark-antiquark potential up to distances of 8 lattice units for pure SU(2) gauge theory on lattices with anisotropic couplings. The action is the Wilson action with a coupling fro time-like plaquettes which differs from those for space-like ones. Numerical simulations are performed in a large range of β. The potential is obtained by fitting 'cooled' Wilson loops with up to 4 exponential terms. An interpolation of the potentials by a sum of a perturbative term, a linear term and by lattice artifacts shows poor scaling in comparison with the isotropic case. If the coupling in the time-like region is reduced, the linear term is much smaller than in the isotropic case, and vice versa. Consequences for the bag picture for hadrons are discussed. (orig.)

  1. Scattered P'P' waves observed at short distances

    Science.gov (United States)

    Earle, Paul S.; Rost, Sebastian; Shearer, Peter M.; Thomas, Christine

    2011-01-01

    We detect previously unreported 1 Hz scattered waves at epicentral distances between 30° and 50° and at times between 2300 and 2450 s after the earthquake origin. These waves likely result from off-azimuth scattering of PKPbc to PKPbc in the upper mantle and crust and provide a new tool for mapping variations in fine-scale (10 km) mantle heterogeneity. Array beams from the Large Aperture Seismic Array (LASA) clearly image the scattered energy gradually emerging from the noise and reaching its peak amplitude about 80 s later, and returning to the noise level after 150 s. Stacks of transverse versus radial slowness (ρt, ρr) show two peaks at about (2, -2) and (-2,-2) s/°, indicating the waves arrive along the major arc path (180° to 360°) and significantly off azimuth. We propose a mantle and surface PKPbc to PKPbc scattering mechanism for these observations because (1) it agrees with the initiation time and distinctive slowness signature of the scattered waves and (2) it follows a scattering path analogous to previously observed deep-mantle PK•KP scattering (Chang and Cleary, 1981). The observed upper-mantle scattered waves and PK•KP waves fit into a broader set of scattered waves that we call P′•d•P′, which can scatter from any depth, d, in the mantle.

  2. Long and Short Distance Migration in Italy : The Role of Economic, Social and Environmental Characteristics

    NARCIS (Netherlands)

    Biagi, Bianca; Faggian, Alessandra; McCann, Philip

    2011-01-01

    This paper analyses Italian interregional migration flows. The approach taken is to decompose labour mobility flows into short distance and long distance migration and to model the effects of economic variables, social capital and quality of life variables, and amenity variables, on the mobility

  3. Relics of short distance effects for the neutron electric dipole moment

    International Nuclear Information System (INIS)

    Eeg, J.O.

    1982-12-01

    The Feynman diagrams which dominate the estimates of the electric dipole moment of the neutron with Kobayashi-Maskawa CP violation are considered. The extracted long distance contributions and the relics of short distance contributions are shown to be complementary and of the same magnitude, resulting in mod(Dsub(n)/e) approximately = (10 - 31 - 10 - 30 ) cm. (Auth.)

  4. Microstructural Abnormalities of Short-Distance White Matter Tracts in Autism Spectrum Disorder

    Science.gov (United States)

    Shukla, Dinesh K.; Keehn, Brandon; Smylie, Daren M.; Muller, Ralph-Axel

    2011-01-01

    Recent functional connectivity magnetic resonance imaging and diffusion tensor imaging (DTI) studies have suggested atypical functional connectivity and reduced integrity of long-distance white matter fibers in autism spectrum disorder (ASD). However, evidence for short-distance white matter fibers is still limited, despite some speculation of…

  5. gmos: Rapid Detection of Genome Mosaicism over Short Evolutionary Distances.

    Science.gov (United States)

    Domazet-Lošo, Mirjana; Domazet-Lošo, Tomislav

    2016-01-01

    Prokaryotic and viral genomes are often altered by recombination and horizontal gene transfer. The existing methods for detecting recombination are primarily aimed at viral genomes or sets of loci, since the expensive computation of underlying statistical models often hinders the comparison of complete prokaryotic genomes. As an alternative, alignment-free solutions are more efficient, but cannot map (align) a query to subject genomes. To address this problem, we have developed gmos (Genome MOsaic Structure), a new program that determines the mosaic structure of query genomes when compared to a set of closely related subject genomes. The program first computes local alignments between query and subject genomes and then reconstructs the query mosaic structure by choosing the best local alignment for each query region. To accomplish the analysis quickly, the program mostly relies on pairwise alignments and constructs multiple sequence alignments over short overlapping subject regions only when necessary. This fine-tuned implementation achieves an efficiency comparable to an alignment-free tool. The program performs well for simulated and real data sets of closely related genomes and can be used for fast recombination detection; for instance, when a new prokaryotic pathogen is discovered. As an example, gmos was used to detect genome mosaicism in a pathogenic Enterococcus faecium strain compared to seven closely related genomes. The analysis took less than two minutes on a single 2.1 GHz processor. The output is available in fasta format and can be visualized using an accessory program, gmosDraw (freely available with gmos).

  6. gmos: Rapid Detection of Genome Mosaicism over Short Evolutionary Distances.

    Directory of Open Access Journals (Sweden)

    Mirjana Domazet-Lošo

    Full Text Available Prokaryotic and viral genomes are often altered by recombination and horizontal gene transfer. The existing methods for detecting recombination are primarily aimed at viral genomes or sets of loci, since the expensive computation of underlying statistical models often hinders the comparison of complete prokaryotic genomes. As an alternative, alignment-free solutions are more efficient, but cannot map (align a query to subject genomes. To address this problem, we have developed gmos (Genome MOsaic Structure, a new program that determines the mosaic structure of query genomes when compared to a set of closely related subject genomes. The program first computes local alignments between query and subject genomes and then reconstructs the query mosaic structure by choosing the best local alignment for each query region. To accomplish the analysis quickly, the program mostly relies on pairwise alignments and constructs multiple sequence alignments over short overlapping subject regions only when necessary. This fine-tuned implementation achieves an efficiency comparable to an alignment-free tool. The program performs well for simulated and real data sets of closely related genomes and can be used for fast recombination detection; for instance, when a new prokaryotic pathogen is discovered. As an example, gmos was used to detect genome mosaicism in a pathogenic Enterococcus faecium strain compared to seven closely related genomes. The analysis took less than two minutes on a single 2.1 GHz processor. The output is available in fasta format and can be visualized using an accessory program, gmosDraw (freely available with gmos.

  7. Effects of short-term swimming exercise on bone mineral density, geometry, and microstructural properties in sham and ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Foong Kiew Ooi

    2014-12-01

    Full Text Available Little information exists about the effects of swimming exercise on bone health in ovariectomized animals with estrogen deficiency, which resembles the postmenopausal state and age-related bone loss in humans. This study investigated the effects of swimming exercise on tibia and femur bone mineral density (BMD, geometry, and microstructure in sham and ovariectomized rats. Forty 3-month-old female rats were divided into four groups: sham operated-sedentary control (Sham-control, sham operated with swimming exercise group (Sham-Swim, ovariectomy-sedentary control (OVx-control, and ovariectomy and swimming exercise (OVx-Swim groups. Swimming sessions were performed by the rats 90 minutes/day for 5 days/week for a total of 8 weeks. At the end of the study, tibial and femoral proximal volumetric total BMD, midshaft cortical volumetric BMD, cross-sectional area, and cross-sectional moment of inertia (MOI, and bone microstructural properties were measured for comparison. Data were analyzed using one-way analysis of variance (ANOVA. The Sham-Swim group exhibited significantly (p < 0.05; one-way ANOVA greater values in bone geometry parameters, that is, tibial midshaft cortical area and MOI compared to the Sham-control group. However, no significant differences were observed in these parameters between the Ovx-Swim and Ovx-control groups. There were no significant differences in femoral BMD between the Sham-Swim and Sham-control groups. Nevertheless, the Ovx-Swim group elicited significantly (p < 0.05; one-way ANOVA higher femoral proximal total BMD and improved bone microstructure compared to the Ovx-Sham group. In conclusion, the positive effects of swimming on bone properties in the ovariectomized rats in the present study may suggest that swimming as a non- or low-weight-bearing exercise may be beneficial for enhancing bone health in the postmenopausal population.

  8. Pregnancy swimming causes short- and long-term neuroprotection against hypoxia-ischemia in very immature rats.

    Science.gov (United States)

    Sanches, Eduardo Farias; Durán-Carabali, Luz Elena; Tosta, Andrea; Nicola, Fabrício; Schmitz, Felipe; Rodrigues, André; Siebert, Cassiana; Wyse, Angela; Netto, Carlos

    2017-09-01

    BackgroundHypoxia-ischemia (HI) is a major cause of neurological damage in preterm newborn. Swimming during pregnancy alters the offspring's brain development. We tested the effects of swimming during pregnancy in the very immature rat brain.MethodsFemale Wistar rats (n=12) were assigned to the sedentary (SE, n=6) or the swimming (SW, n=6) group. From gestational day 0 (GD0) to GD21 the rats in the SW group were made to swim for 20 min/day. HI on postnatal day (PND) 3 rats caused sensorimotor and cognitive impairments. Animals were distributed into SE sham (SESH), sedentary HIP3 (SEHI), swimming sham (SWSH), and swimming HIP3 (SWHI) groups. At PND4 and PND5, Na + /K + -ATPase activity and brain-derived neurotrophic factor (BDNF) levels were assessed. During lactation and adulthood, neurological reflexes, sensorimotor, anxiety-related, and cognitive evaluations were made, followed by histological assessment at PND60.ResultsAt early stages, swimming caused an increase in hippocampal BDNF levels and in the maintenance of Na + /K + -ATPase function in the SWHI group. The SWHI group showed smaller lesions and the preservation of white matter tracts. SEHI animals showed a delay in reflex maturation, which was reverted in the SWHI group. HIP3 induced spatial memory deficits and hypomyelination in SEHI rats, which was reverted in the SWHI group.ConclusionSwimming during pregnancy neuroprotected the brains against HI in very immature neonatal rats.

  9. A Simple Method for Determination of Critical Swimming Velocity in Swimming Flume

    OpenAIRE

    高橋, 繁浩; 若吉, 浩二; Shigehiro, TAKAHASHI; Kohji, WAKAYOSHI; 中京大学; 奈良教育大学教育学部

    2001-01-01

    The purpose of this study was to investigate a simple method for determination of critical swimming velocity (Vcri). Vcri is defined by Wakayoshi et al. (1992) as the swimming speed which could theoretically be maintained forever without exhaustion, and is expressed as the slope of a regression line between swimming distance (D) and swimming time (T) obtained at various swimming speeds. To determine Vcri, 20 well-trained swimmers were measured at several swimming speeds ranging from 1.25 m/se...

  10. On the short-distance double penguin contribution to the K0 - anti K0 mixing

    International Nuclear Information System (INIS)

    Eeg, J.O.

    1985-04-01

    The short-distance contribution of the double penguin box diagram to the K 0 - anti K 0 mixing is investigated. Compared with previous work of other authors, the present paper takes into account the momentum dependence of the box loop, both the non-local part of the penguin and the previously considered local part and the crossed diagrams, which make a class of double penguin diagrams complete. With such new ingredients, is is concluded that the short-distance part of the double penguin is physically irrelevant. After eliminating this particular mechanism for the K 0 - anti K 0 mixing, other potentially relevant mechanisms are pointed out

  11. Formation of metal nanoparticles by short-distance sputter deposition in a reactive ion etching chamber

    International Nuclear Information System (INIS)

    Nie Min; Meng, Dennis Desheng; Sun Kai

    2009-01-01

    A new method is reported to form metal nanoparticles by sputter deposition inside a reactive ion etching chamber with a very short target-substrate distance. The distribution and morphology of nanoparticles are found to be affected by the distance, the ion concentration, and the sputtering time. Densely distributed nanoparticles of various compositions were fabricated on the substrates that were kept at a distance of 130 μm or smaller from the target. When the distance was increased to 510 μm, island structures were formed, indicating the tendency to form continuous thin film with longer distance. The observed trend for nanoparticle formation is opposite to the previously reported mechanism for the formation of nanoparticles by sputtering. A new mechanism based on the seeding effect of the substrate is proposed to interpret the experimental results.

  12. Glucose uptake patterns in exercised skeletal muscles of elite male long-distance and short-distance runners.

    Science.gov (United States)

    Tai, Suh-Jun; Liu, Ren-Shyan; Kuo, Ya-Chen; Hsu, Chi-Yang; Chen, Chi-Hsien

    2010-04-30

    The aim of this study was to determine glucose uptake patterns in exercised skeletal muscles of elite male long-distance and short-distance runners. Positron emission tomography (PET) using 18F-fluoro-2-deoxyglucose (FDG) was performed to determine the patterns of glucose uptake in lower limbs of short-distance (SD group, n=8) and long-distance (LD group, n=8) male runners after a modified 20 min Bruce treadmill test. Magnetic resonance imaging (MRI) was used to delineate the muscle groups in lower limbs. Muscle groups from hip, knee, and ankle movers were measured. The total FDG uptake and the standard uptake value (SUV) for each muscle group were compared between the 2 groups. For the SD and LD runners, the 2 major muscle groups utilizing glucose during running were knee extensors and ankle plantarflexors, which accounted for 49.3 +/- 8.1% (25.1 +/- 4.7% and 24.2 +/- 6.0%) of overall lower extremity glucose uptake for SD group, and 51.3 +/- 8.0% (27.2 +/- 2.7% and 24.0 +/- 8.1%) for LD group. No difference in muscle glucose uptake was noted for other muscle groups. For SD runners, the SUVs for the muscle groups varied from 0.49 +/- 0.27 for the ankle plantarflexors, to 0.20 +/- 0.08 for the hip flexor. For the LD runners, the highest and lowest SUVs were 0.43 +/- 0.15 for the ankle dorsiflexors and 0.21 +/- 0.19 for the hip. For SD and LD groups, no difference in muscle SUV was noted for the muscle groups. However, the SUV ratio between the ankle dorsiflexors and plantarflexors in the LD group was significantly greater than that in the SD group. We thus conclude that the major propelling muscle groups account for approximately 50% of lower limb glucose utilization during running. Thus, the other muscle groups involving maintenance of balance, limb deceleration, and shock absorption utilize an equal amount. This result provides a new insight into glucose distribution in skeletal muscle, suggesting that propellers and supporters are both energetically important

  13. Lifetimes of #betta#'s and μ's and short-distance nuclear phenomena

    International Nuclear Information System (INIS)

    Kisslinger, L.S.

    1982-06-01

    It is shown that short distance phenomena and thus quark structure play vital roles in the theory of #betta# and μ decays in nuclei. A hybrid two-baryon-quark shell model is used to estimate the lifetimes for nonmesonic decays of #betta#'s and μ's in nuclear matter

  14. Prediction of short-distance aerial movement of Phakopsora pachyrhizi urediniospores using machine learning

    Science.gov (United States)

    Dispersal of urediniospores by wind is the primary means of spread for Phakopsora pachyrhizi, the cause of soybean rust. Our research focused on the short distance movement of urediniospores from within the soybean canopy and up to 61 m from field-grown soybean rust infected plants. Environmental va...

  15. Modification of quantum mechanics at short distances: a simple approach to confinement and asymptotic freedom

    International Nuclear Information System (INIS)

    Mahajan, S.M.; Qadir, A.; Valanju, P.M.

    1979-07-01

    To make quantum mechanics a suitable description of short-distance (less than or equal to 10 -13 cm) physics, a spatial variation of Planck's constant anti h is introduced. It is shown that the new theory implies asymptotic freedom and quark confinement in a simple way. 10 references

  16. Risk models for lower extremity injuries among short- and long distance runners : A prospective cohort study

    NARCIS (Netherlands)

    van Poppel, Dennis; Scholten-Peeters, Gwendolijne G.M.; van Middelkoop, Marienke; Koes, Bart W.; Verhagen, Arianne P.

    2018-01-01

    Background: Running injuries are very common. Risk factors for running injuries are not consistently described across studies and do not differentiate between runners of long- and short distances within one cohort. Objectives: The aim of this study is to determine risk factors for running injuries

  17. Short Distance Standoff Raman Detection of Extra Virgin Olive Oil Adulterated with Canola and Grapeseed Oils.

    Science.gov (United States)

    Farley, Carlton; Kassu, Aschalew; Bose, Nayana; Jackson-Davis, Armitra; Boateng, Judith; Ruffin, Paul; Sharma, Anup

    2017-06-01

    A short distance standoff Raman technique is demonstrated for detecting economically motivated adulteration (EMA) in extra virgin olive oil (EVOO). Using a portable Raman spectrometer operating with a 785 nm laser and a 2-in. refracting telescope, adulteration of olive oil with grapeseed oil and canola oil is detected between 1% and 100% at a minimum concentration of 2.5% from a distance of 15 cm and at a minimum concentration of 5% from a distance of 1 m. The technique involves correlating the intensity ratios of prominent Raman bands of edible oils at 1254, 1657, and 1441 cm -1 to the degree of adulteration. As a novel variation in the data analysis technique, integrated intensities over a spectral range of 100 cm -1 around the Raman line were used, making it possible to increase the sensitivity of the technique. The technique is demonstrated by detecting adulteration of EVOO with grapeseed and canola oils at 0-100%. Due to the potential of this technique for making measurements from a convenient distance, the short distance standoff Raman technique has the promise to be used for routine applications in food industry such as identifying food items and monitoring EMA at various checkpoints in the food supply chain and storage facilities.

  18. Perturbative renormalization of composite operators via flow equations. Pt. 2. Short distance expansion

    Energy Technology Data Exchange (ETDEWEB)

    Keller, G. (Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut); Kopper, C. (Goettingen Univ. (Germany). Inst. fuer Theoretische Physik)

    1993-04-01

    We give a rigorous and very detailed derivation of the short distance expansion for a product of two arbitrary composite operators in the framework of the perturbative Euclidean massive [Phi][sub 4][sup 4]. The technically almost trivial proof rests on an extension of the differential flow equation method to Green functions with bilocal insertions, for which we also establish a set of generalized Zimmermann identities and Lowenstein rules. (orig.).

  19. On cutoff effects in lattice QCD from short to long distances

    International Nuclear Information System (INIS)

    Della Morte, Michele; Sommer, Rainer; Takeda, Shinji

    2009-01-01

    We discuss kinematical enhancements of cutoff effects at short and intermediate distances. Starting from a pedagogical example with periodic boundary conditions, we switch to the case of the Schroedinger functional, where the theoretical analysis is checked by precise numerical data with N f =2 dynamical O(a)-improved Wilson quarks. Finally we present an improved determination of the renormalization of the axial current in that theory

  20. On cutoff effects in lattice QCD from short to long distances

    Energy Technology Data Exchange (ETDEWEB)

    Della Morte, Michele [CERN, Physics Department, TH Division, Geneva (Switzerland); Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Takeda, Shinji [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik

    2008-07-15

    We discuss kinematical enhancements of cutoff effects at short and intermediate distances. Starting from a pedagogical example with periodic boundary conditions, we switch to the case of the Schroedinger functional, where the theoretical analysis is checked by precise numerical data with N{sub f}=2 dynamical O(a)-improved Wilson quarks. Finally we present an improved determination of the renormalization of the axial current in that theory. (orig.)

  1. On cutoff effects in lattice QCD from short to long distances

    International Nuclear Information System (INIS)

    Della Morte, Michele; Sommer, Rainer; Takeda, Shinji

    2008-07-01

    We discuss kinematical enhancements of cutoff effects at short and intermediate distances. Starting from a pedagogical example with periodic boundary conditions, we switch to the case of the Schroedinger functional, where the theoretical analysis is checked by precise numerical data with N f =2 dynamical O(a)-improved Wilson quarks. Finally we present an improved determination of the renormalization of the axial current in that theory. (orig.)

  2. Topological effects in QCD and the problem of short-distance singularities

    International Nuclear Information System (INIS)

    Luescher, Martin

    2004-01-01

    The topological susceptibility and the higher moments of the topological charge distribution in QCD are expressed through certain n-point functions of the scalar and pseudo-scalar quark densities at vanishing momenta, which are free of short-distance singularities. Since the normalization of the correlation functions is determined by the non-singlet chiral Ward identities, these formulae provide an unambiguous regularization-independent definition of the moments and thus of the charge distribution

  3. On short-distance CP-violating contributions to the KL,S→γγ processes

    International Nuclear Information System (INIS)

    Eeg, J.O.

    1987-07-01

    New short-distance penguin-induced quark diagrams for K o anti (K o ) → γγ within the standard model are considered. These diagrams leave the total CP-conserving amplitude essentially unchanged. However, the CP-violating amplitude receives a sizeable contribution comparable with the pole contribution, which has so far been considered to be the only contribution including direct CP-violation

  4. Fundamental tests and measures of the structure of matter at short distances

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1981-07-01

    Recent progress in gauge field theories has led to a new perspective on the structure of matter and basic interactions at short distances. It is clear that at very high energies quantum electrodynamics, together with the weak and strong interactions, are part of a unified theory with new fundamental constants, new symmetries, and new conservation laws. A non-technical introduction to these topics is given, with emphasis on fundamental tests and measurements. 21 references

  5. Photoluminescence decay dynamics in γ-Ga2O3 nanocrystals: The role of exclusion distance at short time scales

    Science.gov (United States)

    Fernandes, Brian; Hegde, Manu; Stanish, Paul C.; Mišković, Zoran L.; Radovanovic, Pavle V.

    2017-09-01

    We developed a comprehensive theoretical model describing the photoluminescence decay dynamics at short and long time scales based on the donor-acceptor defect interactions in γ-Ga2O3 nanocrystals, and quantitatively determined the importance of exclusion distance and spatial distribution of defects. We allowed for donors and acceptors to be adjacent to each other or separated by different exclusion distances. The optimal exclusion distance was found to be comparable to the donor Bohr radius and have a strong effect on the photoluminescence decay curve at short times. The importance of the exclusion distance at short time scales was confirmed by Monte Carlo simulations.

  6. Pacing in Swimming: A Systematic Review.

    Science.gov (United States)

    McGibbon, Katie E; Pyne, D B; Shephard, M E; Thompson, K G

    2018-03-20

    Pacing strategy, or how energy is distributed during exercise, can substantially impact athletic performance and is considered crucial for optimal performance in many sports. This is particularly true in swimming given the highly resistive properties of water and low mechanical efficiency of the swimming action. The aim of this systematic review was to determine the pacing strategies utilised by competitive swimmers in competition and their reproducibility, and to examine the impact of different pacing strategies on kinematic, metabolic and performance variables. This will provide valuable and practical information to coaches and sports science practitioners. The databases Web of Science, Scopus, SPORTDiscus and PubMed were searched for published articles up to 1 August 2017. A total of 23 studies examining pool-based swimming competitions or experimental trials in English-language and peer-reviewed journals were included in this review. In short- and middle-distance swimming events maintenance of swimming velocity is critical, whereas in long-distance events a low lap-to-lap variability and the ability to produce an end spurt in the final lap(s) are key. The most effective strategy in the individual medley (IM) is to conserve energy during the butterfly leg to optimise performance in subsequent legs. The pacing profiles of senior swimmers remain relatively stable irrespective of opponents, competition stage or type, and performance time. Implementing event-specific pacing strategies should benefit the performance of competitive swimmers. Given differences between swimmers, there is a need for greater individualisation when considering pacing strategy selection across distances and strokes.

  7. High energy colliders as black hole factories: The end of short distance physics

    International Nuclear Information System (INIS)

    Giddings, Steven B.; Thomas, Scott

    2002-01-01

    If the fundamental Planck scale is of order of a TeV, as is the case in some extra-dimension scenarios, future hadron colliders such as the CERN Large Hadron Collider will be black hole factories. The nonperturbative process of black hole formation and decay by Hawking evaporation gives rise to spectacular events with up to many dozens of relatively hard jets and leptons with a characteristic ratio of hadronic to leptonic activity of roughly 5:1. The total transverse energy of such events is typically a sizable fraction of the beam energy. Perturbative hard scattering processes at energies well above the Planck scale are cloaked behind a horizon, thus limiting the ability to probe short distances. The high energy black hole cross section grows with energy at a rate determined by the dimensionality and geometry of the extra dimensions. This dependence therefore probes the extra dimensions at distances larger than the Planck scale

  8. On the short-distance double penguin contribution to the K0-anti K0 mixing

    International Nuclear Information System (INIS)

    Eeg, J.O.

    1985-01-01

    We investigate the short-distance contribution of the double penguin box diagram to the K 0 -anti K 0 mixing. Compared with previous work of other authors, the present paper takes into account (i) the momentum dependence of the box loop, (ii) both the non-local part of the penguin and the previously considered local part and (iii) the crossed diagrams, which make a class of double penguin diagrams complete. With such new ingredients, we arrive at the conclusion that the SD part of the double penguin is physically irrelevant. After eliminating this particular mechanism for the K 0 -anti K 0 mixing, we point out other potentially relevant mechanisms. (orig.)

  9. Short-distance tumour irradiation system for interstitial and intracavitary use, with preselectable isodose programme

    International Nuclear Information System (INIS)

    Sauerwein, K.

    1976-01-01

    The report describes a new development of the short distance irradiation system for interstitial and intracavitary use, GammaMedsup((R)). First, the main data of GammaMed I are summarized. Next, the development in cooperation with M. Busch of the Essen University Radiation Clinic of GammaMed II is outlined. The new unit includes an Ir-192 point source emitter which scans the applicator probe in accordance with a computer program which can be preselected at random. In this way, all isodose distributions can be achieved which are needed in practice. (orig./HP) [de

  10. Hadronic wave functions at short distances and the operator product expansion

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Lepage, G.P.

    1980-01-01

    The operator product expansion, of appropriate products of quark fields, is used to find the anamalous dimensions which control the short distance behavior of hadronic wave functions. This vehavior in turn controls the high-Q 2 limit of hadronic form factors. In particular, we relate each anamalous dimension of the nonsinglet structure functions to a corresponding logarithmic correction factor to the nominal αsub(s)(Q 2 )/Q 2 fall off of meson form factors. Unlike the case of deep inelastic lepton-hadron scattering, the operator product necessary here involves extra terms which do not contribute to forward matrix elements. (orig.)

  11. Communication with diode laser: short distance line of sight communication using fiber optics

    International Nuclear Information System (INIS)

    Mirza, A.H.

    1999-01-01

    The objective of this project is to carry audio signal from transmitting station to a short distance receiving station along line of sight and also communication through fiber optics is performed, using diode laser light as carrier. In this project optical communication system, modulation techniques, basics of laser and causes of using diode laser are discussed briefly. Transmitter circuit and receiver circuit are fully described. Communication was performed using pulse width modulation technique. Optical fiber communication have many advantages over other type of conventional communication techniques. This report contains the description of optical fiber communication and compared with other communication systems. (author)

  12. Two-photon collisions and short-distance tests of quantum chromodynamics

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1978-12-01

    The physics of two-photon collisions in e +- storage rings is reviewed with emphasis on the predictions of perturbative quantum chromodynamics for high transverse momentum reactions. It is noted that because of the remarkable scaling properties predicted by the theory, two-photon collisions may be proved one of the cleanest tests of the quantum chromodynamics picture of short distance hadron dynamics. In order to contrast these predictions for photon-induced reactions with those for incident hadrons, predictions from quantum chromodynamics for hadron structure functions and form factors at large momentum transfer are also discussed. 55 references

  13. Distance distributions of short polypeptides recovered by fluorescence resonance energy transfer in the 10 A domain.

    Science.gov (United States)

    Sahoo, Harekrushna; Roccatano, Danilo; Zacharias, Martin; Nau, Werner M

    2006-06-28

    Fluorescence resonance energy transfer (FRET) between tryptophan (Trp) as donor and 2,3-diazabicyclo[2.2.2]oct-2-ene (Dbo) as acceptor was studied by steady-state and time-resolved fluorescence spectroscopy. The unique feature of this FRET pair is its exceptionally short Förster radius (10 A), which allows one to recover distance distributions in very short structureless peptides. The technique was applied to Trp-(GlySer)n-Dbo-NH2 peptides with n = 0-10, for which the average probe/quencher distance ranged between 8.7 and 13.7 A experimentally (in propylene glycol, analysis according to wormlike chain model) and 8.6-10.2 A theoretically (for n = 0-6, GROMOS96 molecular dynamics simulations). The larger FRET efficiency in steady-state compared to time-resolved fluorescence experiments was attributed to a static quenching component, suggesting that a small but significant part (ca. 10%) of the conformations are already in van der Waals contact when excitation occurs.

  14. Short-distance matrix elements for $D$-meson mixing for 2+1 lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chia Cheng [Univ. of Illinois, Champaign, IL (United States)

    2015-01-01

    We study the short-distance hadronic matrix elements for D-meson mixing with partially quenched Nf = 2+1 lattice QCD. We use a large set of the MIMD Lattice Computation Collaboration's gauge configurations with a2 tadpole-improved staggered sea quarks and tadpole-improved Lüscher-Weisz gluons. We use the a2 tadpole-improved action for valence light quarks and the Sheikoleslami-Wohlert action with the Fermilab interpretation for the valence charm quark. Our calculation covers the complete set of five operators needed to constrain new physics models for D-meson mixing. We match our matrix elements to the MS-NDR scheme evaluated at 3 GeV. We report values for the Beneke-Buchalla-Greub-Lenz-Nierste choice of evanescent operators.

  15. Coulomb systems distorted at short distances in atomic and nuclear physics

    International Nuclear Information System (INIS)

    Popov, V.S.

    1987-01-01

    In systems bound by the Coulomb interaction distorted at short distances there may appear, under certain conditions, a rearrangment of atomic spectrum (or the Zel'dovich effect). Specific features of this effect are discussed for states with an arbitrary angular momentum l (both with and without the absorption). The equation is studied which connects nuclear level shifts with the low-energy scattering parameters a l , r l . The conditions have been found under which the rearrangement of spectrum is replaced by oscillations of atomic levels. The Coulomb renormalization of scattering lengths and that of effective ranges is discussed. Some manifestations of the Zel'dovich effect in the physics of hadronic atoms and mesomolecules are considered

  16. Measurement of the phase difference between short- and long-distance amplitudes in the [Formula: see text] decay.

    Science.gov (United States)

    Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Babuschkin, I; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baker, S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Baszczyk, M; Batozskaya, V; Batsukh, B; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Bel, L J; Bellee, V; Belloli, N; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Berezhnoy, A; Bernet, R; Bertolin, A; Betancourt, C; Betti, F; Bettler, M-O; van Beuzekom, M; Bezshyiko, Ia; Bifani, S; Billoir, P; Bird, T; Birnkraut, A; Bitadze, A; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Boettcher, T; Bondar, A; Bondar, N; Bonivento, W; Bordyuzhin, I; Borgheresi, A; Borghi, S; Borisyak, M; Borsato, M; Bossu, F; Boubdir, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britsch, M; Britton, T; Brodzicka, J; Buchanan, E; Burr, C; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D H; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cavallero, G; Cenci, R; Chamont, D; Charles, M; Charpentier, Ph; Chatzikonstantinidis, G; Chefdeville, M; Chen, S; Cheung, S-F; Chobanova, V; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombs, G; Coquereau, S; Corti, G; Corvo, M; Costa Sobral, C M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Da Cunha Marinho, F; Dall'Occo, E; Dalseno, J; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Serio, M; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Demmer, M; Dendek, A; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Dijkstra, H; Dordei, F; Dorigo, M; Dosil Suárez, A; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Dungs, K; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Déléage, N; Easo, S; Ebert, M; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Farley, N; Farry, S; Fay, R; Fazzini, D; Ferguson, D; Fernandez Prieto, A; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fini, R A; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fleuret, F; Fohl, K; Fontana, M; Fontanelli, F; Forshaw, D C; Forty, R; Franco Lima, V; Frank, M; Frei, C; Fu, J; Funk, W; Furfaro, E; Färber, C; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Garcia Martin, L M; García Pardiñas, J; Garra Tico, J; Garrido, L; Garsed, P J; Gascon, D; Gaspar, C; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gizdov, K; Gligorov, V V; Golubkov, D; Golutvin, A; Gomes, A; Gorelov, I V; Gotti, C; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Griffith, P; Grillo, L; Gruberg Cazon, B R; Grünberg, O; Gushchin, E; Guz, Yu; Gys, T; Göbel, C; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hatch, M; He, J; Head, T; Heister, A; Hennessy, K; Henrard, P; Henry, L; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hombach, C; Hopchev, H; Hulsbergen, W; Humair, T; Hushchyn, M; Hutchcroft, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jiang, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Karacson, M; Kariuki, J M; Karodia, S; Kecke, M; Kelsey, M; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Koliiev, S; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Kosmyntseva, A; Kozachuk, A; Kozeiha, M; Kravchuk, L; Kreplin, K; Kreps, M; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Leflat, A; Lefrançois, J; Lefèvre, R; Lemaitre, F; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, T; Li, Y; Likhomanenko, T; Lindner, R; Linn, C; Lionetto, F; Liu, X; Loh, D; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Lyu, X; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Maltsev, T; Manca, G; Mancinelli, G; Manning, P; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marinangeli, M; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massacrier, L M; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurice, E; Maurin, B; Mazurov, A; McCann, M; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Melnychuk, D; Merk, M; Merli, A; Michielin, E; Milanes, D A; Minard, M-N; Mitzel, D S; Mogini, A; Molina Rodriguez, J; Monroy, I A; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Morgunova, O; Moron, J; Morris, A B; Mountain, R; Muheim, F; Mulder, M; Mussini, M; Müller, D; Müller, J; Müller, K; Müller, V; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, T D; Nguyen-Mau, C; Nieswand, S; Niet, R; Nikitin, N; Nikodem, T; Nogay, A; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Oldeman, R; Onderwater, C J G; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Pais, P R; Palano, A; Palombo, F; Palutan, M; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parker, W; Parkes, C; Passaleva, G; Pastore, A; Patel, G D; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petrov, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pikies, M; Pinci, D; Pistone, A; Piucci, A; Placinta, V; Playfer, S; Plo Casasus, M; Poikela, T; Polci, F; Poluektov, A; Polyakov, I; Polycarpo, E; Pomery, G J; Popov, A; Popov, D; Popovici, B; Poslavskii, S; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Quagliani, R; Rachwal, B; Rademacker, J H; Rama, M; Ramos Pernas, M; Rangel, M S; Raniuk, I; Ratnikov, F; Raven, G; Redi, F; Reichert, S; Dos Reis, A C; Remon Alepuz, C; Renaudin, V; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Rogozhnikov, A; Roiser, S; Rollings, A; Romanovskiy, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rudolph, M S; Ruf, T; Ruiz Valls, P; Saborido Silva, J J; Sadykhov, E; Sagidova, N; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schellenberg, M; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schubert, K; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Simone, S; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, I T; Smith, J; Smith, M; Snoek, H; Soares Lavra, L; Sokoloff, M D; Soler, F J P; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefko, P; Stefkova, S; Steinkamp, O; Stemmle, S; Stenyakin, O; Stevens, H; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Sun, L; Sutcliffe, W; Swientek, K; Syropoulos, V; Szczekowski, M; Szumlak, T; T'Jampens, S; Tayduganov, A; Tekampe, T; Tellarini, G; Teubert, F; Thomas, E; van Tilburg, J; Tilley, M J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Toriello, F; Tournefier, E; Tourneur, S; Trabelsi, K; Traill, M; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tully, A; Tuning, N; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valassi, A; Valat, S; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Venkateswaran, A; Vernet, M; Vesterinen, M; Viana Barbosa, J V; Viaud, B; Vieira, D; Vieites Diaz, M; Viemann, H; Vilasis-Cardona, X; Vitti, M; Volkov, V; Vollhardt, A; Voneki, B; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Vázquez Sierra, C; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wang, J; Ward, D R; Wark, H M; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wicht, J; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wraight, K; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yao, Y; Yin, H; Yu, J; Yuan, X; Yushchenko, O; Zarebski, K A; Zavertyaev, M; Zhang, L; Zhang, Y; Zhang, Y; Zhelezov, A; Zheng, Y; Zhu, X; Zhukov, V; Zucchelli, S

    2017-01-01

    A measurement of the phase difference between the short- and long-distance contributions to the [Formula: see text] decay is performed by analysing the dimuon mass distribution. The analysis is based on pp collision data corresponding to an integrated luminosity of 3[Formula: see text] collected by the LHCb experiment in 2011 and 2012. The long-distance contribution to the [Formula: see text] decay is modelled as a sum of relativistic Breit-Wigner amplitudes representing different vector meson resonances decaying to muon pairs, each with their own magnitude and phase. The measured phases of the [Formula: see text] and [Formula: see text] resonances are such that the interference with the short-distance component in dimuon mass regions far from their pole masses is small. In addition, constraints are placed on the Wilson coefficients, [Formula: see text] and [Formula: see text], and the branching fraction of the short-distance component is measured.

  17. Voluntary resistance running with short distance enhances spatial memory related to hippocampal BDNF signaling.

    Science.gov (United States)

    Lee, Min Chul; Okamoto, Masahiro; Liu, Yu Fan; Inoue, Koshiro; Matsui, Takashi; Nogami, Haruo; Soya, Hideaki

    2012-10-15

    Although voluntary running has beneficial effects on hippocampal cognitive functions if done abundantly, it is still uncertain whether resistance running would be the same. For this purpose, voluntary resistance wheel running (RWR) with a load is a suitable model, since it allows increased work levels and resultant muscular adaptation in fast-twitch muscle. Here, we examined whether RWR would have potential effects on hippocampal cognitive functions with enhanced hippocampal brain-derived neurotrophic factor (BDNF), as does wheel running without a load (WR). Ten-week-old male Wistar rats were assigned randomly to sedentary (Sed), WR, and RWR (to a maximum load of 30% of body weight) groups for 4 wk. We found that in RWR, work levels increased with load, but running distance decreased by about half, which elicited muscular adaptation for fast-twitch plantaris muscle without causing any negative stress effects. Both RWR and WR led to improved spatial learning and memory as well as gene expressions of hippocampal BDNF signaling-related molecules. RWR increased hippocampal BDNF, tyrosine-related kinase B (TrkB), and cAMP response element-binding (CREB) protein levels, whereas WR increased only BDNF. With both exercise groups, there were correlations between spatial memory and BDNF protein (r = 0.41), p-CREB protein (r = 0.44), and work levels (r = 0.77). These results suggest that RWR plays a beneficial role in hippocampus-related cognitive functions associated with hippocampal BDNF signaling, even with short distances, and that work levels rather than running distance are more determinant of exercise-induced beneficial effects in wheel running with and without a load.

  18. Particle transport patterns of short-distance soil erosion by wind-driven rain, rain and wind

    Science.gov (United States)

    Marzen, Miriam; Iserloh, Thomas; de Lima, João L. M. P.; Ries, Johannes B.

    2015-04-01

    Short distance erosion of soil surface material is one of the big question marks in soil erosion studies. The exact measurement of short-distance transported soil particles, prior to the occurrence of overland flow, is a challenge to soil erosion science due to the particular requirements of the experimental setup and test procedure. To approach a quantification of amount and distance of each type of transport, we applied an especially developed multiple-gutter system installed inside the Trier Portable Wind and Rainfall Simulator (PWRS). We measured the amount and travel distance of soil particles detached and transported by raindrops (splash), wind-driven rain (splash-saltation and splash-drift) and wind (saltation). The test setup included three different erosion agents (rain/ wind-driven rain/ wind), two substrates (sandy/ loamy), three surface structures (grain roughness/ rills lengthwise/ rills transversal) and three slope angles (0°/+7°/-7°). The results present detailed transport patterns of the three erosion agents under the varying soil and surface conditions up to a distance of 1.6 m. Under the applied rain intensity and wind velocity, wind-driven rain splash generates the highest erosion. The erodibility and travel distance of the two substrates depend on the erosion agent. The total erosion is slightly higher for the slope angle -7° (downslope), but for wind-driven rain splash, the inclination is not a relevant factor. The effect of surface structures (rills) changes with traveling distance. The wind driven rain splash generates a much higher amount of erosion and a further travel distance of the particles due to the combined action of wind and rain. The wind-driven rain factor appears to be much more significant than the other factors. The study highlights the effects of different erosion agents and surface parameters on short-distance particle transport and the powerful impact of wind-driven rain on soil erosion.

  19. Short-distance behavior of the Bethe--Salpeter wave function in the ladder approximation

    International Nuclear Information System (INIS)

    Guth, A.H.; Soper, D.E.

    1975-01-01

    We investigate the short-distance behavior of the (Wick-rotated) Bethe--Salpeter wave function for the two spin-1/2 quarks bound by the exchange of a massive vector meson. We use the ladder-model kernel, which has the same p -4 scaling behavior as the true kernel in a theory with a fixed point of the renormalization group at g not equal to 0. For a bound state with the quantum numbers of the pion, the leading asymptotic behavior is chi (q/sup μ/) approx. cq/sup -4 + epsilon(g)/γ 5 , where epsilon (g) =1- (1-g 2 /π 2 ) 1 / 2 . Our method also provides the full asymptotic series, although it should be noted that the nonleading terms will depend on the nonleading behavior of the ladder-model kernel. A general term has the form cq - /sup a/(lnq)/sup n/phi (q/sup μ/), where c is an unknown constant, a may be integral or nonintegral, n is an integer, and phi (q/sup μ/) is a representation function of the rotation group in four dimensions

  20. Hawking radiation from acoustic black holes, short distance and back reaction effects

    International Nuclear Information System (INIS)

    Balbinot, R.; Fabbri, A.; Parentani, R.

    2004-01-01

    Using the action principle we first review how linear density perturbations (sound waves) in an Eulerian fluid obey a relativistic equation: the d'Alembert equation. This analogy between propagation of sound and that of a massless scalar field in a Lorentzian metric also applies to non-homogeneous flows. In these cases, sound waves effectively propagate in a curved four-dimensional acoustic metric whose properties are determined by the flow. Using this analogy, we consider regular flows which become supersonic, and show that the acoustic metric behaves like that of a black hole. The analogy is so good that, when considering quantum mechanics, acoustic black holes should produce a thermal flux of Hawking phonons. We then focus on two interesting questions related to Hawking radiation which are not fully understood in the context of gravitational black holes due to the lack of a theory of quantum gravity. The first concerns the calculation of the modifications of Hawking radiation which are induced by dispersive effects at short distances, approaching the atomic scale when considering sound. We generalize existing treatments and calculate the modifications caused by the propagation near the black-hole horizon. The second question concerns back reaction effects. We return to the Eulerian action, compute second-order effects, and show that the back reaction of sound waves on the fluid's flow can be expressed in terms of their stress-energy tensor. Using this result in the context of Hawking radiation, we compute the secular effect on the background flow

  1. Circular swimming in mice after exposure to a high magnetic field.

    Science.gov (United States)

    Houpt, Thomas A; Houpt, Charles E

    2010-06-16

    There is increasing evidence that exposure to high magnetic fields of 4T and above perturbs the vestibular system of rodents and humans. Performance in a swim test is a sensitive test of vestibular function. In order to determine the effect of magnet field exposure on swimming in mice, mice were exposed for 30 min within a 14.1T superconducting magnet and then tested at different times after exposure in a 2-min swim test. As previously observed in open field tests, mice swam in tight counter-clockwise circles when tested immediately after magnet exposure. The counter-clockwise orientation persisted throughout the 2-min swim test. The tendency to circle was transient, because no significant circling was observed when mice were tested at 3 min or later after magnet exposure. However, mice did show a decrease in total distance swum when tested between 3 and 40 min after magnet exposure. The decrease in swimming distance was accompanied by a pronounced postural change involving a counter-clockwise twist of the pelvis and hindlimbs that was particularly severe in the first 15s of the swim test. Finally, no persistent difference from sham-exposed mice was seen in the swimming of magnet-exposed mice when tested 60 min, 24h, or 96 h after magnet exposure. This suggests that there is no long-lasting effect of magnet exposure on the ability of mice to orient or swim. The transient deficits in swimming and posture seen shortly after magnet exposure are consistent with an acute perturbation of the vestibular system by the high magnetic field. (c) 2010 Elsevier Inc. All rights reserved.

  2. Modification of quantum mechanics at short distances: a simple approach to confinement and asymptotic freedom. [Planck constant

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, S.M.; Qadir, A.; Valanju, P.M.

    1979-07-01

    To make quantum mechanics a suitable description of short-distance (less than or equal to 10/sup -13/ cm) physics, a spatial variation of Planck's constant anti h is introduced. It is shown that the new theory implies asymptotic freedom and quark confinement in a simple way. 10 references.

  3. Modeling of competitive activity of skilled athletes specialized at 1500 m distance on short-track skating

    Directory of Open Access Journals (Sweden)

    O.S. Kholodova

    2013-10-01

    Full Text Available Background: Models of competitive activity at the 1500 m distance on short-track skating are developed on the basis of defining the relationship between sports results and major characteristics which describe speed of running at different parts of the distance. Material: we analyzed reports of competitions at the European and World Championships, World Cups 2007-2011. The dynamics of the speed finalists of the competition at the 1500 m - in hits (n = 33, quarterfinals (n = 34, semi-finals (n = 32 and finals (n = 39. Results: it was determined that for a distance of 1500 m short track skating is the most appropriate model with factors of influence: the speed of the first to sixth part of distance , the speed difference between the first and second half of the distance, time of the slowest circle, the difference between the time of the slowest and fastest circles. Conclusions: time of overcoming of distance will diminish at the rational change of model indexes. It will allow to increase possibility of output in the next circle of competitions and accordingly improve a place in final protocol.

  4. Short term effects of kinesiotaping on acromiohumeral distance in asymptomatic subjects: a randomised controlled trial.

    Science.gov (United States)

    Luque-Suarez, A; Navarro-Ledesma, S; Petocz, P; Hancock, M J; Hush, J

    2013-12-01

    The first aim of this study was to investigate whether kinesiotaping (KT) can increase the acromiohumeral distance (AHD) in asymptomatic subjects in the short term. The second aim was to investigate whether the direction of kinesiotaping application influences AHD. In recent years, the use of KT has become increasingly popular for a range of musculoskeletal conditions and for sport injuries. To date, we are unaware of any research investigating the effect of kinesiotaping on AHD. Moreover, it is unknown whether the direction of kinesiotaping application for the shoulder is important. Forty nine participants were randomly assigned to one of three groups: kinesiotaping group 1 (KT1), kinesiotaping group 2 (KT2) and sham kinesiotaping (KT3). AHD ultrasound measurements at 0° and 60° of shoulder elevation were collected at baseline and immediately after kinesiotape application. The results showed significant improvements in AHD after kinesiotaping, compared with sham taping. The mean difference in AHD between KT1 and KT3 groups was 1.28 mm (95% CI: 0.55, 2.03), and between KT2 and KT3 was 0.98 mm (95% CI: 0.23, 1.74). Comparison of KT1 and KT2 groups, which was performed to identify whether the direction of taping influences the AHD, indicated there were no significant differences. KT increases AHD in healthy individuals immediately following application, compared with sham kinesiotape. No differences were found with respect to the direction in which KT was applied. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Long-distance propagation of intense short laser pulse in air

    International Nuclear Information System (INIS)

    Yu Wei; Yu, M.Y.; Zhang, J.; Qian, L.J.; Yuan, X.; Lu, P.X.; Li, R.X.; Sheng, Z.M.; Liu, J.R.; Xu, Z.Z.

    2004-01-01

    Long-distance propagation of intense laser pulse in air is reconsidered analytically by generalizing the analogy between the laser spotsize and the orbit of a classical particle. It is shown that multiphoton ionization introduces unique features to the laser-air interaction, thereby enabling the long-distance behavior. Several interesting characteristics of the latter are pointed out

  6. Immobility time during the forced swimming test predicts sensitivity to amitriptyline, whereas traveled distance in the circular corridor indicates resistance to treatment in female Wistar rats.

    Science.gov (United States)

    Flores-Serrano, Ana G; Zaldívar-Rae, Jaime; Salgado, Humberto; Pineda, Juan C

    2015-03-25

    Among the main issues in the pharmacological treatment of depression are the wide variation in response to antidepressants among individual patients and the lack of indexes that allow prediction of which drug will be effective in a particular case. We evaluated whether differential sensitivity to amitriptyline is related to dichotomous categorization of individuals on the basis of their behavioral responses to two common paradigms used to evaluate the potential of tricyclic drugs as antidepressants. Hence, we categorized a cohort of 38 female rats on the basis of their immobility time in the conditioning phase of the forced swimming test [FST; high immobility (HI) vs. low immobility (LI) rats] and their locomotor behavior in the circular corridor test [high locomotor response (HR) vs. low locomotor response (LR) rats]. We subjected the rodents to the FST while under the influence of vehicle (n=20) or amitriptyline (15 mg/kg; n=18). We found no statistical evidence of dependence between categorizations of rats on the basis of their behavior in the FST and circular corridor test. Rats categorized as HI/LI and HR/LR significantly differed in their sensitivity/resistance to amitriptyline, as evidenced by changes (or lack thereof) in their immobility time, climbing time, and swimming time during the FST. These results confirm that different behavioral styles among rats are linked to differential sensitivity/resistance to antidepressants. However, we specifically found that categorizing rats as HI/LI better reflected sensitivity to amitriptyline, whereas categorizing them as HR/LR better revealed resistance to the drug. These differential responses should be considered in experimental approaches. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

  7. Short bi-iliac distance in prenatal Ullrich-Turner syndrome

    DEFF Research Database (Denmark)

    Hartling, Ulla B; Hansen, Birgit Fischer; Keeling, Jean W

    2002-01-01

    The purpose of the present study is to evaluate the bi-iliac distance and the caudo-cranial position of the iliac bones in Ullrich-Turner syndrome (UTS) fetuses compared to recently published standards for normal fetuses. Whole-body radiographs in antero-posterior projections of 24 UTS fetuses...... in normal fetuses. The bi-iliac distance and the iliac bone position have not previously been described in Ullrich-Turner syndrome fetuses....

  8. The short distance contribution to the Bs → γγ decay in the SM and MSSM

    International Nuclear Information System (INIS)

    Devidze, G.G.

    2000-06-01

    The complete calculation of the short distance contributions to the B s → γγ decay in the SM and MSSM are presented. The branching ratio and relative part of CP-even state of final photons are calculated. The branching ratio and relative part of CP-even state of final photons in the MSSM maybe significantly larger than the standard model estimate. (author)

  9. Effect of race distance on muscle oxygenation in short-track speed skating.

    Science.gov (United States)

    Hesford, Catherine M; Laing, Stewart; Cardinale, Marco; Cooper, Chris E

    2013-01-01

    Previous work identified an asymmetry in tissue desaturation changes in the left and right quadriceps muscles during on-ice skating at maximal speed in males. The effect of changing race distance on the magnitude of desaturation or leg asymmetry is unknown. Six elite male skaters (age = 23 ± 1.8 yr, height = 1.8 ± 0.1 m, mass = 80.1 ± 5.7 kg, midthigh skinfold thickness = 7 ± 2 mm) and four elite female skaters (age = 21 ± 4 yr, height = 1.6 ± 0.1 m, mass = 65.2 ± 4.3 kg, midthigh skinfold thickness = 10 ± 1 mm) were studied. Subjects completed time trials over three race distances. Blood lactate concentration and O2 uptake measurements were combined with near-infrared spectroscopy measures of muscle oxygenation (TSI) and blood volume (tHb) in the right and left vastus lateralis. Neither race distance nor gender had a significant effect on the magnitude of maximal muscle desaturation (ΔTSI(max)). Pattern of local changes in tHb during individual laps was dependent upon subtle differences in skating technique used for the different race distances. Linear regression analysis revealed asymmetry between the right and left leg desaturation in males during the final stages of each race distance, but not in females. At all race distances, local muscle desaturation reached maximal values much more quickly than global VO(2peak). The use of wearable near-infrared spectroscopy devices enabled measurement of muscle oxygenation during competitive race simulation, thus providing unique insight into the effects of velocity and technique changes on local muscle oxygenation. This may have implications for training and race pacing in speed skating.

  10. In situ swimming speed and swimming behaviour of fish feeding on the krill Meganyctiphanes norvegica

    OpenAIRE

    Onsrud, M. S. R.; Kaartvedt, Stein; Breien, M. T.

    2005-01-01

    In situ swimming speed and swimming behaviour of dielly migrating planktivorous fish were studied at a 120-m-deep location. Acoustic target tracking was performed using a hull-mounted transducer and submersible transducers located on the sea bottom and free hanging in the water column. The original data displayed a relationship between distance to transducer and swimming speed. A simplistic smoother applied during post-processing, appeared to break this relationship. Target tracki...

  11. Functional magnetic resonance microscopy of long- and short-distance water transport in trees

    NARCIS (Netherlands)

    Homan, N.

    2009-01-01

    Due to their long life span, changing climatic conditions are of particular importance for trees. Climate changes will affect the water balance, which can become an important limiting factor for photosynthesis and growth. Long-distance water transport in trees is directly related to the

  12. Galaxy as fundamental calibrator of the extragalactic distance scale. I. The basic scale factors of the galaxy and two kinematic tests of the long and short distance scales

    International Nuclear Information System (INIS)

    de Vaucouleurs, G.

    1983-01-01

    A new version of the oldest approach to estimating the distances of galaxies (direct comparison with our Galaxy) is proposed to relate the extragalactic distance scale to the basic metric, photometric, and kinematic scale factors of the Galaxy. These include the galactocentric distance of the Sun, R/sub sun/, the total magnitude of the Galaxy, M 0 /sub T/, and its spheroidal component, M 0 /sub I/, the galactic rotation velocity of the local standard of rest, V(R/sub sun/), the central velocity dispersion sigma/sub ν/(0) of the spheroidal component, and related parameters. The following ''most probable'' values and their mean errors are adopted from a variety of recent determinations: morphological type of galaxy, SABX(rXs)bc(T = 4 +- 0.5), R/sub sun/ = 8.5 +- 0.5 kpc, M 0 /sub T/(B) = -20.2 +- 0.15, (B-V) 0 /sub T/ = 0.53 +- 0.04, M 0 /sub I/(B) = -18.2 +- 0.3, (B-V) 0 /sub I/ = 0.65 +- 0.05, V(R/sub sun/) = 220 +- 15 km s -1 , sigma/sub ν/(0) = 130 +- 7 km s -1 . 1. The zero points of the Tully-Fisher (T-F) relations, -M 0 /sub T/(B) = a(B)+5(log V/sub M/ -2.2), in the B/sub T/ system, and -M/sup c/(H) = a(H)+10(log W 20 -2.5), in the H/sub -0.5/ system, are determined in terms of the galactocentric distance of the Sun R/sub sun/, and the galactic rotation velocity of the local standard of rest, V(R/sub sun/)equivalentV 0 roughly-equalV/sub M/, or the corresponding line width W 20 . The galactic zero point a(B) agrees within 0.1 mag with that (19.4 +- 0.15) previously derived on the short scale from 11 nearby calibrating galaxies

  13. K0-anti K0 mixing: Approaching its short-distance origin and heavy flavours through loops

    International Nuclear Information System (INIS)

    Picek, I.

    1986-03-01

    There have been three 'mysteries' in the history of the K-meson system: two of the pre-1964 physics as summarized by Feynman, 1) the unknown reasons for strangeness, 2) the unknown inner machinery of the K 0 -anti K 0 mixing, and the third, revealed to us in 1964, 3) CP violation. The attempts to explain these puzzles have been crucial in building the present, standard-model (SM) picture for understanding of elementary particle physics. As regards the first two points, I first want to illustrate how their study has opened the door to heavy flavours. Then I focus on some recently proposed short-distance K 0 -anti K 0 mixing mechanisms, and also remind the reader of the problem of separating short-distance (SD) from long-distance (LD) effects. As for CP violation 3), it is often considered to be just on the border of the SM. The observation of CP violation, still restricted to the K 0 meson, makes it that the K 0 -anti K 0 system is still one of the most intriguing systems in nature. The increasing body of data from heavy-quark physics have a chance to move the kaon from such a 'strange' (if not distinguished) place, and to provide a valuable test of the SM. (orig.)

  14. Short binary convolutional codes with maximal free distance for rates 2/3 and 3/4

    DEFF Research Database (Denmark)

    Paaske, Erik

    1974-01-01

    . Farther, the search among the remaining codes is started in a subset in which we expect the possibility of finding codes with large values ofd_{free}to be good. A number of short, optimum (in the sense of maximizingd_{free}), rate-2/3 and 3/4 codes found by the search procedure are listed.......A search procedure is developed to find good short binary(N,N - 1)convolutional codes. It uses simple rules to discard from the complete ensemble of codes a large fraction whose free distanced_{free}either cannot achieve the maximum value or is equal tod_{free}of some code in the remaining set...

  15. 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

  16. Plume dispersion and deposition processes of tracer gas and aerosols in short-distance experiments

    International Nuclear Information System (INIS)

    Taeschner, M.; Bunnenberg, C.

    1988-01-01

    Data used in this paper were extracted from field experiments carried out in France and Canada to study the pathway of elementary tritium after possible emissions from future fusion reactors and from short-range experiments with nutrient aerosols performed in a German forest in view of a therapy of damaged coniferous trees by foliar nutrition. Comparisons of dispersion parameters evaluated from the tritium field experiments show that in the case of the 30-min release the variations of the wind directions represent the dominant mechanism of lateral plume dispersion under unstable weather conditions. This corresponds with the observation that for the short 2-min emission the plume remains more concentrated during propagation, and the small lateral dispersion parameters typical for stable conditions have to be applied. The investigations on the dispersion of aerosol plumes into a forest boundary layer show that the Gaussian plume model can be modified by a windspeed factor to be valid for predictions on aerosol concentrations and depositions even in a structured topography like a forest

  17. Signature of short distance physics on inflation power spectrum and CMB anisotropy

    International Nuclear Information System (INIS)

    Das, Suratna; Mohanty, Subhendra

    2009-01-01

    The inflaton field responsible for inflation may not be a canonical fundamental scalar. It is possible that the inflaton is a composite of fermions or it may have a decay width. In these cases the standard procedure for calculating the power spectrum is not applicable and a new formalism needs to be developed to determine the effect of short range interactions of the inflaton on the power spectrum and the CMB anisotropy. We develop a general formalism for computing the power spectrum of curvature perturbations for such non-canonical cases by using the flat space Källén-Lehmann spectral function in curved quasi-de Sitter space assuming implicitly that the Bunch-Davis boundary conditions enforces the inflaton mode functions to be plane wave in the short wavelength limit and a complete set of mode functions exists in quasi-de Sitter space. It is observed that the inflaton with a decay width suppresses the power at large scale while a composite inflaton's power spectrum oscillates at large scales. These observations may be vindicated in the WMAP data and confirmed by future observations with PLANCK

  18. Hadronic light-by-light scattering in the muon g-2: A new short-distance constraint on pion exchange

    International Nuclear Information System (INIS)

    Nyffeler, Andreas

    2009-01-01

    Recently it was pointed out that for the evaluation of the numerically dominant pion-exchange contribution to the hadronic light-by-light scattering correction in the muon g-2, a fully off-shell pion-photon-photon form factor should be used. Following this proposal, we first derive a new short-distance constraint on the off-shell form factor which enters at the external vertex for the muon g-2 and show that it is related to the quark condensate magnetic susceptibility in QCD. We then evaluate the pion-exchange contribution in the framework of large-N C QCD using an off-shell form factor which fulfills all short-distance constraints. With a value for the magnetic susceptibility as estimated in the same large-N C framework, we obtain the result a μ LbyL;π 0 =(72±12)x10 -11 . Updating our earlier results for the contributions from the exchanges of the η and η ' using simple vector-meson dominance form factors, we obtain a μ LbyL;PS =(99±16)x10 -11 for the sum of all light pseudoscalars. Combined with available evaluations for the other contributions to hadronic light-by-light scattering this leads to the new estimate a μ LbyL;had =(116±40)x10 -11 .

  19. RELIABILITY AND ACCURACY OF 10 HZ GPS DEVICES FOR SHORT-DISTANCE EXERCISE

    Directory of Open Access Journals (Sweden)

    Julen Castellano

    2011-03-01

    Full Text Available The use of GPS technology for training and research purposes requires a study of the reliability, validity and accuracy of the data generated (Petersen et al., 2009. To date, studies have focused on devices with a logging rate of 1 Hz and 5 Hz (Coutts and Duffield, 2010; Duffield et al., 2010; Jennings et al., 2010; MacLeod et al., 2009; Petersen et al., 2009; Portas et al., 2010, although it seems that more frequent sampling can increase the accuracy of the information provided by these devices (Jennings et al., 2010; MacLeod et al., 2009, Portas et al., 2010. However, we are unaware of any study of the reliability and accuracy of GPS devices using a sampling frequency of 10 Hz. Thus, the aim of the present research was to determine the reliability and accuracy of GPS devices operating at a sampling frequency of 10 Hz, in relation here to sprints of 15 m and 30 m and using both video and photoelectric cells.Nine trained male athletes participated in the study. Each participant completed 7 and 6 linear runs of 15 m and 30 m, respectively (n = 117, with only one GPS device being used per participant. Each repetition required them to complete the route as quickly as possible, with 1 min recovery between sets. Distance was monitored through the use of GPS devices (MinimaxX v4.0, Catapult Innovations, Melbourne, Australia operating at the above mentioned sampling frequency of 10 Hz. In addition, all tests were filmed with a video camera operating at a sampling frequency of 25 frames. Data were collected during what were considered to be good GPS conditions in terms of the weather and satellite conditions (number of satellites = 10.0 ± 0.2 and 10.3 ± 0.4 for sprints of 15 m and 30 m, respectively.Distance was measured using a tape measure. Electronic timing gates (TAG- Heuer, CP 520 Training model, Switzerland were used to obtain a criterion sprint time accurate to 0.01 s, with gates being placed at the beginning and end of the route (Petersen et

  20. On the Inclusion of Short-distance Bystander Effects into a Logistic Tumor Control Probability Model.

    Science.gov (United States)

    Tempel, David G; Brodin, N Patrik; Tomé, Wolfgang A

    2018-01-01

    Currently, interactions between voxels are neglected in the tumor control probability (TCP) models used in biologically-driven intensity-modulated radiotherapy treatment planning. However, experimental data suggests that this may not always be justified when bystander effects are important. We propose a model inspired by the Ising model, a short-range interaction model, to investigate if and when it is important to include voxel to voxel interactions in biologically-driven treatment planning. This Ising-like model for TCP is derived by first showing that the logistic model of tumor control is mathematically equivalent to a non-interacting Ising model. Using this correspondence, the parameters of the logistic model are mapped to the parameters of an Ising-like model and bystander interactions are introduced as a short-range interaction as is the case for the Ising model. As an example, we apply the model to study the effect of bystander interactions in the case of radiation therapy for prostate cancer. The model shows that it is adequate to neglect bystander interactions for dose distributions that completely cover the treatment target and yield TCP estimates that lie in the shoulder of the dose response curve. However, for dose distributions that yield TCP estimates that lie on the steep part of the dose response curve or for inhomogeneous dose distributions having significant hot and/or cold regions, bystander effects may be important. Furthermore, the proposed model highlights a previously unexplored and potentially fruitful connection between the fields of statistical mechanics and tumor control probability/normal tissue complication probability modeling.

  1. Short distance movement of genomic negative strands in a host and nonhost for Sugarcane mosaic virus (SCMV

    Directory of Open Access Journals (Sweden)

    Hernández-Vela Juan

    2011-01-01

    Full Text Available Abstract Background In order to obtain an initial and preliminary understanding of host and nonhost resistance in the initial step of potyvirus replication, both positive and negative Sugarcane mosaic virus (SCMV strands where traced in inoculated and systemic leaves in host and nonhost resistant maize and sugarcane for one Mexican potyviral isolate (SCMV-VER1. Intermediary replication forms, such as the negative viral strand, seem to only move a short distance as surveyed by RT-PCR analysis and ELISA in different leaves. Virus purification was also done in leaves and stems. Results Susceptible maize plants allowed for viral SCMV replication, cell-to-cell, and long distance movement, as indicated by the presence of the coat protein along the plant. In the host resistant maize plants for the SCMV-VER1 isolate, the virus was able to establish the disease though the initial steps of virus replication, as detected by the presence of negative strands, in the basal area of the inoculated leaves at six and twelve days post inoculation. The nonhost sugarcane for SCMV-VER1 and the host sugarcane for SCMV-CAM6 also allowed the initial steps of viral replication for the VER1 isolate in the local inoculated leaf. SCMV-VER1 virions could be extracted from stems of susceptible maize with higher titers than leaves. Conclusion Nonhost and host resistance allow the initial steps of potyvirus SCMV replication, as shown by the negative strands' presence. Furthermore, both hosts allow the negative viral strands' local movement, but not their systemic spread through the stem. The presence of larger amounts of extractable virions from the stem (as compared to the leaves in susceptible maize lines suggests their long distance movement as assembled particles. This will be the first report suggesting the long distance movement of a monocot potyvirus as a virion.

  2. Short communication: Microbial quality of raw milk following commercial long-distance hauling.

    Science.gov (United States)

    Darchuk, Emily M; Meunier-Goddik, Lisbeth; Waite-Cusic, Joy

    2015-12-01

    Hauling is a critical part of the commercial milk supply chain, yet very few studies have aimed to understand its effect on raw milk quality. This study focused on the effect of extended-duration tanker use during hauling on raw milk quality at a commercial facility. Standard tanker use [cleaned-in-place (CIP) once per 24h] served as a control and an incremental between-load water rinse with sanitizer treatment (RS) was evaluated to mitigate any effect from extended duration hauling. During this study, 1 commercial truck with 2 trailers was monitored for 10d. The truck collected milk at a large dairy farm, transported the milk to a manufacturing facility, and then returned to the same farm for a second load. Each round-trip journey took between 10 and 12h, allowing for 2 loads per 24-h use period. Following the second delivery, the truck was cleaned by CIP treatment starting a new treatment day. Producer samples were collected from the raw milk bulk tank on the farm before loading milk into the tanker. The same milk was sampled directly out of the tanker truck before unloading at the manufacturer. Effect on individual bacteria count, thermophilic spore count, and preliminary incubation count was quantified through common industry tests. Surface sponge swabs were also used to monitor tanker sanitation and the efficacy of cleaning treatments. Results did not identify a negative effect on raw milk quality due to extended duration hauling. Whereas the addition of RS did not provide any measurable quality benefits for the microbial milk quality, swab results demonstrated that the RS treatment was able to reduce surface bacteria in the tanker, although not to the same level as the full CIP treatment. Based on this study, current CIP practices for long distance milk hauling appear to be effective in mitigating any measurable effect on raw milk quality. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Human-Structure Dynamic Interaction during Short-Distance Free Falls

    Directory of Open Access Journals (Sweden)

    E. Shahabpoor

    2016-01-01

    Full Text Available The dynamic interactions of falling human bodies with civil structures, regardless of their potentially critical effects, have sparsely been researched in contact biomechanics. The physical contact models suggested in the existing literature, particularly for short-distant falls in home settings, assume the human body falls on a “rigid” (not vibrating ground. A similar assumption is usually made during laboratory-based fall tests, including force platforms. Based on observations from a set of pediatric head-first free fall tests, the present paper shows that the dynamics of the grounded force plate are not always negligible when doing fall test in a laboratory setting. By using a similar analogy for lightweight floor structures, it is shown that ignoring the dynamics of floors in the contact model can result in an up to 35% overestimation of the peak force experienced by a falling human. A nonlinear contact model is suggested, featuring an agent-based modelling approach, where the dynamics of the falling human and the impact object (force plate or a floor structure here are each modelled using a single-degree-of-freedom model to simulate their dynamic interactions. The findings of this research can have wide applications in areas such as impact biomechanics and sports science.

  4. Polycomb domain formation depends on short and long distance regulatory cues.

    Directory of Open Access Journals (Sweden)

    Bernd Schuettengruber

    Full Text Available BACKGROUND: Polycomb group (PcG proteins dynamically define cellular identities through the epigenetic repression of key developmental genes. In Drosophila, cis-regulatory regions termed PcG response elements (PREs act as nucleation sites for PcG proteins to create large repressive PcG domains that are marked by trimethylation of lysine 27 on histone H3 (H3K27me3. In addition to an action in cis, PREs can interact over long distances, thereby enhancing PcG dependent silencing. How PcG domains are established, which factors limit their propagation in cis, and how long range interactions of PREs in trans affect the chromatin structure is largely unknown. PRINCIPAL FINDINGS: We demonstrate that the insertion of a PRE-containing transgene in the Drosophila genome generates an artificial PcG domain and we analyze its organization by quantitative ChIP and ChIP-on-chip experiments. Intriguingly, a boundary element and known insulator proteins do not necessarily interfere with spreading of H3K27me3. Instead, domain borders correlate with the presence of promoter regions bound by RNA Polymerase II and active chromatin marks. In contrast, genes that are silent during early fly development get included within the PcG domain and this incorporation interferes with gene activation at later developmental stages. Moreover, trans-interaction of the transgenic PRE with its homologous endogenous PRE results in increased PcG binding, correlating with reinforced silencing of genes within the domain borders. CONCLUSIONS: Our results suggest that higher-order organization of PcG-bound chromatin can stabilize gene silencing within PcG domains. Further we propose that multi-protein complexes associated with active promoters are able to define the limits of PcG domains. Future work aimed to pinpoint the factors providing this barrier function will be required to understand the precise molecular mechanism by which active promoter regions can act as boundaries to stop

  5. 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.

  6. COTS low-cost 622-Mb/s free-space laser communications link for short-distance commercial applications

    Science.gov (United States)

    Morrison, Kenneth A.

    2000-05-01

    The results from a low cost 622 Mb/s, free-space laser communication link operating at 850 nm for short distance commercial applications is presented. The test results demonstrate the use of a free-space laser communications transceiver for building to building applications such as LAN, WAN and ATM operations, etc. This illustrates the potential for wide-use commercial computer network applications. The transceiver is constructed of commercial off-the-shelf materials for the development of a low-cost laser communications data link. The test system configuration utilizes standard Personal Computers with network cards and signal conversion cards for the copper to optical medical conversion. These tests precede the development of an increased data rate device operating at 2.5 Gb/s.

  7. 'Bluetooth' for radio-connecting short distance; Kinkyori wo musen setsuzokusuru 'Bluetooth'

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    'Bluetooth' is a new connection method for radio-connecting a short distance by means of mobile equipment including a note PC, PC peripheral equipment and portable telephone, using 2.4GHz ISM (Industrial Scientific Medical) band. It is capable of making a network without a complex operation, enabling data and audio communications. In May, 1998, an operation for deciding on the specifications was started under the leadership of five companies consisting of Ericsson, Nokia, Intel, IBM and Toshiba, with the specification version 1.0 completed in July, 1999 and opened to the public. (readable on http://www.bluetooth.com). Using such features as low power consumption, low cost and small size, the 'Bluetooth' will be mounted on various kinds of mobile equipment and developed in mobile PAN (Personal Area Network). (translated by NEDO)

  8. Gender and distance influence performance predictors in young swimmers

    Directory of Open Access Journals (Sweden)

    Paulo Victor Mezzaroba

    2013-12-01

    Full Text Available Predictors of performance in adult swimmers are constantly changing during youth especially because the training routine begins even before puberty in the modality. Therefore this study aimed to determine the group of parameters that best predict short and middle swimming distance performances of young swimmers of both genders. Thirty-three 10-to 16-years-old male and female competitive swimmers participated in the study. Multiple linear regression (MLR was used considering mean speed of maximum 100, 200 and 400 m efforts as dependent variables, and five parameters groups as possible predictors (anthropometry, body composition, physiological and biomechanical parameters, chronological age/pubic hair. The main results revealed explanatory powers of almost 100% for both genders and all performances, but with different predictors entered in MLR models of each parameter group or all variables. Thus, there are considerable differences in short and middle swimming distance, and males and females predictors that should be considered in training programs.

  9. Upward swimming of a sperm cell in shear flow.

    Science.gov (United States)

    Omori, Toshihiro; Ishikawa, Takuji

    2016-03-01

    Mammalian sperm cells are required to swim over long distances, typically around 1000-fold their own length. They must orient themselves and maintain a swimming motion to reach the ovum, or egg cell. Although the mechanism of long-distance navigation is still unclear, one possible mechanism, rheotaxis, was reported recently. This work investigates the mechanism of the rheotaxis in detail by simulating the motions of a sperm cell in shear flow adjacent to a flat surface. A phase diagram was developed to show the sperm's swimming motion under different shear rates, and for varying flagellum waveform conditions. The results showed that, under shear flow, the sperm is able to hydrodynamically change its swimming direction, allowing it to swim upwards against the flow, which suggests that the upward swimming of sperm cells can be explained using fluid mechanics, and this can then be used to further understand physiology of sperm cell navigation.

  10. Swimming pool cleaner poisoning

    Science.gov (United States)

    Swimming pool cleaner poisoning occurs when someone swallows this type of cleaner, touches it, or breathes in ... The harmful substances in swimming pool cleaner are: Bromine ... copper Chlorine Soda ash Sodium bicarbonate Various mild acids

  11. Swimming pool granuloma

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001357.htm Swimming pool granuloma To use the sharing features on this page, please enable JavaScript. A swimming pool granuloma is a long-term (chronic) skin ...

  12. Laryngoscopy during swimming

    DEFF Research Database (Denmark)

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

    2017-01-01

    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....

  13. Diarrhea and Swimming

    Science.gov (United States)

    ... 888) 232-6348 Contact CDC–INFO Healthy Swimming Health Benefits of Water-based Exercise Swimmer Protection Steps of ... Disinfection Microbial Testing & Disinfection Swimming Pool Chemicals Injuries & Outdoor Health International Recreational Water RWIs, Swimmer Hygiene, & Behavioral ...

  14. Gender and distance influence performance predictors in young swimmers

    OpenAIRE

    Mezzaroba, Paulo Victor; Papoti, Marcelo; Machado, Fabiana Andrade

    2013-01-01

    Predictors of performance in adult swimmers are constantly changing during youth especially because the training routine begins even before puberty in the modality. Therefore this study aimed to determine the group of parameters that best predict short and middle swimming distance performances of young swimmers of both genders. Thirty-three 10-to 16-years-old male and female competitive swimmers participated in the study. Multiple linear regression (MLR) was used considering mean speed of max...

  15. Quiet swimming at low Reynolds number

    DEFF Research Database (Denmark)

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

    2015-01-01

    The stresslet provides a simple model of the flow created by a small, freely swimming and neutrally buoyant aquatic organism and shows that the far field fluid disturbance created by such an organism in general decays as one over distance squared. Here we discuss a quieter swimming mode that elim......The stresslet provides a simple model of the flow created by a small, freely swimming and neutrally buoyant aquatic organism and shows that the far field fluid disturbance created by such an organism in general decays as one over distance squared. Here we discuss a quieter swimming mode...... that eliminates the stresslet component of the flow and leads to a faster spatial decay of the fluid disturbance described by a force quadrupole that decays as one over distance cubed. Motivated by recent experimental results on fluid disturbances due to small aquatic organisms, we demonstrate that a three......-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...

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Flow disturbances generated by feeding and swimming zooplankton

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, Haisong; Goncalves, R. J.

    2014-01-01

    that zooplankton, in which feeding and swimming are separate processes, produce flow disturbances during swimming with a much faster spatial attenuation (velocity u varies with distance r as u ∝ r−3 to r−4) than that produced by zooplankton for which feeding and propulsion are the same process (u ∝ r−1 to r−2...... vortex rings, or by “breast-stroke swimming.” Both produce rapidly attenuating flows. The more “noisy” swimming of those that are constrained by a need to simultaneously feed is due to constantly beating flagella or appendages that are positioned either anteriorly or posteriorly on the (cell) body...

  18. Cost-effective up to 40 Gbit/s transmission performance of 1310 nm directly modulated lasers for short to medium range distances

    NARCIS (Netherlands)

    Huiszoon, B.; Jonker, R.J.W.; Bennekom, van P.K.; Khoe, G.D.; Waardt, de H.

    2005-01-01

    This paper presents successful 20 and 40 Gb/s potentially low-cost transmission experiments using 1310 nm directly modulated distributed feedback lasers (DMLs) in the very-short- to medium-range distances. This paper will recommend operating conditions for error-free transmission at these bit rates

  19. Swimming-pool piles

    International Nuclear Information System (INIS)

    Trioulaire, M.

    1959-01-01

    In France two swimming-pool piles, Melusine and Triton, have just been set in operation. The swimming-pool pile is the ideal research tool for neutron fluxes of the order of 10 13 . This type of pile can be of immediate interest to many research centres, but its cost must be reduced and a break with tradition should be observed in its design. It would be an advantage: - to bury the swimming-pool; - to reject the experimental channel; - to concentrate the cooling circuit in the swimming-pool; - to carry out all manipulations in the water; - to double the core. (author) [fr

  20. The correlation between sports results in swimming and general and special muscle strength

    Directory of Open Access Journals (Sweden)

    Wioletta Lubkowska

    2017-12-01

    Full Text Available Introduction. Swimming as a sport encompasses various styles and distances (from 50 up to 1,500 meters. The correlation between sports results and general/special muscle strength seems unquestionable. Aim. The purpose of this paper is to answer the question related to maintaining the proportion between muscle strength development (which depends mainly on land-based trainings and endurance trainings in water. Material and methods. The study covered 14 leading swimmers from MKP Szczecin who specialized mainly in short and medium distances; they were members of the national senior and junior teams in the 2013/14 training year. The general strength tests were conducted at the beginning and at the end of the winter and summer preparatory periods. The following tests were performed: bench-pressing, pull-ups and bar dips. At the end of the main research period, a thrust test was conducted on land (on a swim bench, as well as a thrust test in the water. Results. All participants demonstrated progress in results between the summer season and the winter season. The range of training loads was higher in the summer due to the length of preparation (by about 100%. The individual progress was, however, very varied. Conclusions. The level of sports progress achieved by individual swimmers was greatly diversified. The relatively high level of general and special strength in the tested swimmers was linked to their need to display these motor skills while swimming. Subjects who showed the greatest progress in the general and special strength trials, displayed the biggest improvement in their swimming performance during the competition season. Swimmers with a fairly high level of strength, but a moderate sports level should analyze and improve their swimming technique. Subjects whose progress in general and special strength tests was the least significant, should try and achieve progress by developing other technical and coordination skills.

  1. LOL--Limitations of Online Learning--Are We Selling the Open and Distance Education Message Short?

    Science.gov (United States)

    Todhunter, Barrie

    2013-01-01

    The thesis of this paper is that the open and distance education sector is based on a framework of terminology that is typologically inconsistent and which lacks clarity, and open and distance education teaching and learning models are examined to explore these concerns. The findings of this analysis are then used to assist in the articulation of…

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

    Science.gov (United States)

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

    1998-01-01

    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 distance and time (Distance = critical velocity x time + anaerobic swimming capacity) is used to determine the individual capacity of the aerobic and anaerobic metabolic pathways. Although there is confidence that critical velocity and anaerobic swimming capacity are fitness measures that separate aerobic and anaerobic components, a firm theoretical basis for the interpretation of these results does not exist. The purpose of this study was to evaluate the critical power concept and anaerobic swimming capacity as measures of the aerobic and anaerobic capacity using a modeling approach. A systems model was developed that relates the mechanics and energetics involved in front crawl swimming performance. From actual swimming flume measurements, the time dependent aerobic and anaerobic energy release was modeled. Data derived from the literature were used to relate the energy cost of front crawl swimming to swimming velocity. A balance should exist between the energy cost to swim a distance in a certain time and the concomitant aerobic and anaerobic energy release. The ensuing model was used to predict performance times over a range of distances (50-1500 m) and to calculate the regression line between swimming distance and time. Using a sensitivity analysis, it was demonstrated that the critical velocity is indicative for the capacity of the aerobic energy system. Estimates of the anaerobic swimming capacity, however, were influenced by variations in both anaerobic and aerobic energy release. Therefore, it was concluded that the anaerobic swimming capacity does not provide a reliable estimate of the anaerobic capacity.

  3. 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'.

  4. 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...

  5. 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

  6. A calculation method of the optimal distance of the long-drawn short-pressure type localfan in minebased on the principle of the jet and Suction volume

    Science.gov (United States)

    Fu, Shaotong

    2018-01-01

    In order to dilute the harmful smoke and dust of the working surface in the production of the roadway in the mine shaft, the combination of mine local ventilation is often considered when conditions permitting. However there is no definite method to determine the distance between fan and working surface. Considering the concentration of smoke, the size of working face, the ventilation time, the wind speed of the working face and the principle of suction volume, this paper analyzes the long - drawn short - pressure type of the ventilation scheme, and presents an optimal algorithm for the distance between the exhaust ventilator and the working face:{{L}}{{o}}=\\frac{{({{{v}}}{{f}}{{t}})}{{Z}}{{{S}}}{{o}}\\frac{\\exists }{{{z}}{{β }}}}{3.398{{{S}}}W\\frac{1}{{{z}}{{A}}}}. Then this paperpresentsa reference distance for different wind speed requirements of a project.

  7. Experimental hydrodynamics of swimming in fishes

    Science.gov (United States)

    Tytell, Eric Daniel

    2005-11-01

    The great diversity of fish body shapes suggests that they have adapted to different selective pressures. For many fishes, the pressures include hydrodynamic demands: swimming efficiently or accelerating rapidly, for instance. However, the hydrodynamic advantages or disadvantages to specific morphologies are poorly understood. In particular, eels have been considered inefficient swimmers, but they migrate long distances without feeding, a task that requires efficient swimming. This dissertation, therefore, begins with an examination of the swimming hydrodynamics of American eels, Anguilla rostrata, at steady swimming speeds from 0.5 to 2 body lengths (L) per second and during accelerations from -1.4 to 1.3 L s -2. The final chapter examines the hydrodynamic effects of body shape directly by describing three-dimensional flow around swimming bluegill sunfish, Lepomis macrochirus. In all chapters, flow is quantified using digital particle image velocimetry, and simultaneous kinematics are measured from high-resolution digital video. The wake behind a swimming eel in the horizontal midline plane is described first. Rather than producing a wake with fluid jets angled backwards, like in fishes such as sunfish, eels have a wake with exclusively lateral jets. The lack of downstream momentum indicates that eels balance the axial forces of thrust and drag evenly over time and over their bodies, and therefore do not change axial fluid momentum. This even balance, present at all steady swimming speeds, is probably due to the relatively uniform body shape of eels. As eels accelerate, thrust exceeds drag, axial momentum increases, and the wake approaches that of other fishes. During steady swimming, though, the lack of axial momentum prevents direct efficiency estimation. The effect of body shape was examined directly by measuring flow in multiple transverse planes along the body of bluegill sunfish swimming at 1.2 L s-1. The dorsal and anal fin, neglected in many previous

  8. Short (

    NARCIS (Netherlands)

    Telleman, Gerdien; den Hartog, Laurens

    2013-01-01

    Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

  9. Swimming Pool Safety

    Science.gov (United States)

    ... Spread the Word Shop AAP Find a Pediatrician Safety & Prevention Immunizations All Around At Home At Play ... Español Text Size Email Print Share Swimming Pool Safety Page Content ​What is the best way to ...

  10. Swimming pool special; Zwembadspecial

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-05-15

    This issue includes a few articles and messages on the use of heat pump systems in swimming pools. [Dutch] Dit nummer bevat onder meer een paar artikelen over het gebruik van warmtepompsystemen in zwembaden.

  11. Static and Dynamic Accuracy of an Innovative Miniaturized Wearable Platform for Short Range Distance Measurements for Human Movement Applications

    Directory of Open Access Journals (Sweden)

    Stefano Bertuletti

    2017-06-01

    Full Text Available Magneto-inertial measurement units (MIMU are a suitable solution to assess human motor performance both indoors and outdoors. However, relevant quantities such as step width and base of support, which play an important role in gait stability, cannot be directly measured using MIMU alone. To overcome this limitation, we developed a wearable platform specifically designed for human movement analysis applications, which integrates a MIMU and an Infrared Time-of-Flight proximity sensor (IR-ToF, allowing for the estimate of inter-object distance. We proposed a thorough testing protocol for evaluating the IR-ToF sensor performances under experimental conditions resembling those encountered during gait. In particular, we tested the sensor performance for different (i target colors; (ii sensor-target distances (up to 200 mm and (iii sensor-target angles of incidence (AoI (up to 60 ∘ . Both static and dynamic conditions were analyzed. A pendulum, simulating the oscillation of a human leg, was used to generate highly repeatable oscillations with a maximum angular velocity of 6 rad/s. Results showed that the IR-ToF proximity sensor was not sensitive to variations of both distance and target color (except for black. Conversely, a relationship between error magnitude and AoI values was found. For AoI equal to 0 ∘ , the IR-ToF sensor performed equally well both in static and dynamic acquisitions with a distance mean absolute error <1.5 mm. Errors increased up to 3.6 mm (static and 11.9 mm (dynamic for AoI equal to ± 30 ∘ , and up to 7.8 mm (static and 25.6 mm (dynamic for AoI equal to ± 60 ∘ . In addition, the wearable platform was used during a preliminary experiment for the estimation of the inter-foot distance on a single healthy subject while walking. In conclusion, the combination of magneto-inertial unit and IR-ToF technology represents a valuable alternative solution in terms of accuracy, sampling frequency, dimension and power consumption

  12. Geneva 24 hours swim

    CERN Document Server

    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

  13. Geneva 24 Hours Swim

    CERN Document Server

    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

  14. A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

    Science.gov (United States)

    Loturco, I; Barbosa, A C; Nocentini, R K; Pereira, L A; Kobal, R; Kitamura, K; Abad, C C C; Figueiredo, P; Nakamura, F Y

    2016-03-01

    Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=- 0.82 and -0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=- 0.85 and -0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=- 0.72 and -0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=- 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers. © Georg Thieme Verlag KG Stuttgart · New York.

  15. 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 ...

  16. 2012 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.

  17. Healthy Swimming/Recreational Water

    Science.gov (United States)

    ... Medical Professionals En Español Publications, Data, & Statistics Healthy Swimming Resources Health Promotion Materials Find Your State Training & ... Announcements Outbreak Response Toolkits CDC at Work: Healthy Swimming Fast Facts Index of Water-Related Topics Model ...

  18. Representing distance, consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    Title: Representing Distance, Consuming Distance Abstract: Distance is a condition for corporeal and virtual mobilities, for desired and actual travel, but yet it has received relatively little attention as a theoretical entity in its own right. Understandings of and assumptions about distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...

  19. Double peak-induced distance error in short-time-Fourier-transform-Brillouin optical time domain reflectometers event detection and the recovery method.

    Science.gov (United States)

    Yu, Yifei; Luo, Linqing; Li, Bo; Guo, Linfeng; Yan, Jize; Soga, Kenichi

    2015-10-01

    The measured distance error caused by double peaks in the BOTDRs (Brillouin optical time domain reflectometers) system is a kind of Brillouin scattering spectrum (BSS) deformation, discussed and simulated for the first time in the paper, to the best of the authors' knowledge. Double peak, as a kind of Brillouin spectrum deformation, is important in the enhancement of spatial resolution, measurement accuracy, and crack detection. Due to the variances of the peak powers of the BSS along the fiber, the measured starting point of a step-shape frequency transition region is shifted and results in distance errors. Zero-padded short-time-Fourier-transform (STFT) can restore the transition-induced double peaks in the asymmetric and deformed BSS, thus offering more accurate and quicker measurements than the conventional Lorentz-fitting method. The recovering method based on the double-peak detection and corresponding BSS deformation can be applied to calculate the real starting point, which can improve the distance accuracy of the STFT-based BOTDR system.

  20. Quiet swimming at low Reynolds number

    Science.gov (United States)

    Andersen, Anders; Wadhwa, Navish; Kiørboe, Thomas

    2015-04-01

    The stresslet provides a simple model of the flow created by a small, freely swimming and neutrally buoyant aquatic organism and shows that the far field fluid disturbance created by such an organism in general decays as one over distance squared. Here we discuss a quieter swimming mode that eliminates the stresslet component of the flow and leads to a faster spatial decay of the fluid disturbance described by a force quadrupole that decays as one over distance cubed. Motivated by recent experimental results on fluid disturbances due to small aquatic organisms, we demonstrate that a three-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 are valid surprisingly close to the organism. Finally, we discuss point force models as a general framework for hypothesis generation and experimental exploration of fluid mediated predator-prey interactions in the planktonic world.

  1. Development of an imaging-planning program for screen/film and computed radiography mammography for breasts with short chest wall to nipple distance.

    Science.gov (United States)

    Dong, S L; Su, J L; Yeh, Y H; Chu, T C; Lin, Y C; Chuang, K S

    2011-04-01

    Imaging breasts with a short chest wall to nipple distance (CWND) using a traditional mammographic X-ray unit is a technical challenge for mammographers. The purpose of this study is the development of an imaging-planning program to assist in determination of imaging parameters of screen/film (SF) and computed radiography (CR) mammography for short CWND breasts. A traditional mammographic X-ray unit (Mammomat 3000, Siemens, Munich, Germany) was employed. The imaging-planning program was developed by combining the compressed breast thickness correction, the equivalent polymethylmethacrylate thickness assessment for breasts and the tube loading (mAs) measurement. Both phantom exposures and a total of 597 exposures were used for examining the imaging-planning program. Results of the phantom study show that the tube loading rapidly decreased with the CWND when the automatic exposure control (AEC) detector was not fully covered by the phantom. For patient exposures with the AEC fully covered by breast tissue, the average fractional tube loadings, defined as the ratio of the predicted mAs using the imaging-planning program and mAs of the mammogram, were 1.10 and 1.07 for SF and CR mammograms, respectively. The predicted mAs values were comparable to the mAs values, as determined by the AEC. By applying the imaging-planning program in clinical practice, the experiential dependence of the mammographer for determination of the imaging parameters for short CWND breasts is minimised.

  2. 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.

  3. 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.

  4. Biochemical and hematological changes following the 120-km open-water marathon swim.

    Science.gov (United States)

    Drygas, Wojciech; Rębowska, Ewa; Stępień, Ewa; Golański, Jacek; Kwaśniewska, Magdalena

    2014-09-01

    Data on physiological effects and potential risks of a ultraendurance swimming are scarce. This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim on the Warta River, Poland. Pre-swimming examinations revealed favorable conditions (blood pressure, 110/70 mmHg; rest heart rate, 54 beats/minute, ejection fraction, 60%, 20.2 metabolic equivalents in a maximal exercise test). The swimming time and distance covered were 27 h 33 min and 120 km, respectively. Blood samples for hematological and biochemical parameters were collected 30 min, 4 hrs, 10 hrs and 8 days after the swim. The body temperature of the swimmer was 36.7°C before and 35.1°C after the swim. The hematological parameters remained within the reference range in the postexercise period except for leucocytes (17.5 and 10.6 x G/l noted 30 minutes and 4 hours after the swim, respectively). Serum urea, aspartate aminotransferase and C-reactive protein increased above the reference range reaching 11.3 mmol/l, 1054 nmol/l/s and 25.9 mg/l, respectively. Symptomatic hyponatremia was not observed. Although the results demonstrate that an experienced athlete is able to complete an ultra-marathon swim without negative health consequences, further studies addressing the potential risks of marathon swimming are required. Key pointsData on biochemical changes due to long-distance swimming are scarce.This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim.An experienced athlete is able to complete an ultra-marathon swim without serious health consequences.Regarding the growing popularity of marathon swimming further studies addressing the potential risks of such exhaustive exercise are required.

  5. Sleep habits, alertness, cortisol levels, and cardiac autonomic activity in short-distance bus drivers: differences between morning and afternoon shifts.

    Science.gov (United States)

    Diez, Joaquín J; Vigo, Daniel E; Lloret, Santiago Pérez; Rigters, Stephanie; Role, Noelia; Cardinali, Daniel P; Chada, Daniel Pérez

    2011-07-01

    To evaluate sleep, alertness, salivary cortisol levels, and autonomic activity in the afternoon and morning shifts of a sample of short-distance bus drivers. A sample of 47 bus drivers was evaluated. Data regarding subjects and working characteristics, alertness (psychomotor vigilance task), sleep habits (Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Actigraphy), endocrine stress response (salivary cortisol), and autonomic activity (heart-rate variability) were collected. Sleep restriction was highly prevalent. Drivers in the morning shift slept 1 hour less than those in the afternoon shift, showed lower reaction time performance, a flattening of cortisol morning-evening difference, and higher overweight prevalence. The differences found between morning and afternoon shifts point out to the need of the implementation of educational strategies to compensate the sleep loss associated with an early work schedule.

  6. Stirring by swimming bodies

    International Nuclear Information System (INIS)

    Thiffeault, Jean-Luc; Childress, Stephen

    2010-01-01

    We consider the stirring of an inviscid fluid caused by the locomotion of bodies through it. The swimmers are approximated by non-interacting cylinders or spheres moving steadily along straight lines. We find the displacement of fluid particles caused by the nearby passage of a swimmer as a function of an impact parameter. We use this to compute the effective diffusion coefficient from the random walk of a fluid particle under the influence of a distribution of swimming bodies. We compare with the results of simulations. For typical sizes, densities and swimming velocities of schools of krill, the effective diffusivity in this model is five times the thermal diffusivity. However, we estimate that viscosity increases this value by two orders of magnitude.

  7. Searching for Criteria in Evaluating the Monofin Swimming Turn from the Perspective of Coaching and Improving Technique

    Science.gov (United States)

    Rejman, Marek; Borowska, Grażyna

    2008-01-01

    This study aims to analysise the selected kinematic parameters of the monofin swimming turn. The high complexity of performing turns is hindered by the large surface of the monofin, which disturbs control and sense of the body in water. A lack of objective data available on monofin swimming turns has resulted in field research connected with the specification of parameters needed for the evaluation of the technique. Therefore, turns observed in elite swimmers contain underlying conclusions for objective criteria, ensuring the highest level of coaching and the improving of turns in young swimmers. Six, high level, male swimmers participated in the study. The subject of the analysis was the fastest turn, from one out of three trial turns made after swimming a distance of 25 m. Images of the turns were collected from two cameras located under water in accordance with the procedures of the previous analyses of freestyle turns. The images were digitized and analysed by the SIMI®- Movement Analysis System. The interdependency of the total turn time and the remaining recorded parameters, constituted the basis for analysis of the kinematic parameters of five turn phases. The interdependency was measured using r- Pearson’s correlation coefficients. The novel character of the subject covered in this study, forced interpretation of the results on the basis of turn analyses in freestyle swimming. The results allow for the creation of a diagram outlinig area of search for an effective and efficient monofin swimming turn mechanism. The activities performed from the moment of wall contact until the commencement of stroking seem to be crucial for turn improvement. A strong belief has resulted that, the correct monofin swimming turn, is more than just a simple consequence of the fastest performance of all its components. The most important criteria in evaluating the quality of the monofin swimming turn are: striving for the optimal extension of wall contact time, push-off time

  8. Intra- and Intersexual swim bladder dimorphisms in the plainfin midshipman fish (Porichthys notatus): Implications of swim bladder proximity to the inner ear for sound pressure detection.

    Science.gov (United States)

    Mohr, Robert A; Whitchurch, Elizabeth A; Anderson, Ryan D; Forlano, Paul M; Fay, Richard R; Ketten, Darlene R; Cox, Timothy C; Sisneros, Joseph A

    2017-11-01

    The plainfin midshipman fish, Porichthys notatus, is a nocturnal marine teleost that uses social acoustic signals for communication during the breeding season. Nesting type I males produce multiharmonic advertisement calls by contracting their swim bladder sonic muscles to attract females for courtship and spawning while subsequently attracting cuckholding type II males. Here, we report intra- and intersexual dimorphisms of the swim bladder in a vocal teleost fish and detail the swim bladder dimorphisms in the three sexual phenotypes (females, type I and II males) of plainfin midshipman fish. Micro-computerized tomography revealed that females and type II males have prominent, horn-like rostral swim bladder extensions that project toward the inner ear end organs (saccule, lagena, and utricle). The rostral swim bladder extensions were longer, and the distance between these swim bladder extensions and each inner-ear end organ type was significantly shorter in both females and type II males compared to that in type I males. Our results revealed that the normalized swim bladder length of females and type II males was longer than that in type I males while there was no difference in normalized swim bladder width among the three sexual phenotypes. We predict that these intrasexual and intersexual differences in swim bladder morphology among midshipman sexual phenotypes will afford greater sound pressure sensitivity and higher frequency detection in females and type II males and facilitate the detection and localization of conspecifics in shallow water environments, like those in which midshipman breed and nest. © 2017 Wiley Periodicals, Inc.

  9. Swimming education in Australian society.

    OpenAIRE

    Lynch, TJ

    2014-01-01

    Abstract: The purpose of this paper is to explore a community swimming program using autoethnography qualitative research. Autoethnography is an approach to research and writing that seeks to describe and systematically analyze (graphy) personal experience (auto) in order to understand cultural experience (ethno) (Ellis 2004; Holman Jones 2005). Through childhood reflection of lived swimming experiences, and adult life reflection of lived swimming teaching experiences as a primary school teac...

  10. Short philtrum

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003302.htm Short philtrum To use the sharing features on this page, please enable JavaScript. A short philtrum is a shorter than normal distance between ...

  11. Short-distance expansion for the electromagnetic half-space Green's tensor: general results and an application to radiative lifetime computations

    International Nuclear Information System (INIS)

    Panasyuk, George Y; Schotland, John C; Markel, Vadim A

    2009-01-01

    We obtain a short-distance expansion for the half-space, frequency domain electromagnetic Green's tensor. The small parameter of the theory is ωε 1 L/c, where ω is the frequency, ε 1 is the permittivity of the upper half-space, in which both the source and the point of observation are located, and which is assumed to be transparent, c is the speed of light in vacuum and L is a characteristic length, defined as the distance from the point of observation to the reflected (with respect to the planar interface) position of the source. In the case when the lower half-space (the substrate) is characterized by a complex permittivity ε 2 , we compute the expansion to third order. For the case when the substrate is a transparent dielectric, we compute the imaginary part of the Green's tensor to seventh order. The analytical calculations are verified numerically. The practical utility of the obtained expansion is demonstrated by computing the radiative lifetime of two electromagnetically interacting molecules in the vicinity of a transparent dielectric substrate. The computation is performed in the strong interaction regime when the quasi-particle pole approximation is inapplicable. In this regime, the integral representation for the half-space Green's tensor is difficult to use while its electrostatic limiting expression is grossly inadequate. However, the analytical expansion derived in this paper can be used directly and efficiently. The results of this study are also relevant to nano-optics and near-field imaging, especially when tomographic image reconstruction is involved

  12. 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.

  13. Design and analysis of InN - In0.25Ga0.75N single quantum well laser for short distance communication wavelength

    Science.gov (United States)

    Polash, Md. Mobarak Hossain; Alam, M. Shah; Biswas, Saumya

    2018-03-01

    A single quantum well semiconductor laser based on wurtzite-nitride is designed and analyzed for short distance communication wavelength (at around 1300 nm). The laser structure has 12 Å well layer of InN, 15 Å barrier layer of In0.25Ga0.75N, and 54 Å separate confinement heterostructure layer of GaN. To calculate the electronic characteristics of the structure, a self-consistent method is used where Hamiltonian with effective mass approximation is solved for conduction band while six-bands Hamiltonian matrix with k · p formalism including the polarization effect, valence-band mixing effect, and strain effect is solved for valence band. The interband optical transition elements, optical gain, differential gain, radiative current density, spontaneous emission rate, and threshold characteristics have been calculated. The wave function overlap integral is found to be 45.93% for TE-polarized structure. Also, the spontaneous emission rate is found to be 6.57 × 1027 s - 1 cm - 3 eV - 1 at 1288.21 nm with the carrier density of 5 × 1019 cm - 3. Furthermore, the radiative current density and the radiative recombination rate are found to be 121.92 A cm - 2 and 6.35 × 1027 s - 1 cm - 3, respectively, while the TE-polarized optical gain of the structure is 3872.1 cm - 1 at 1301.7 nm.

  14. Circulating β-endorphin, adrenocorticotrophic hormone and cortisol levels of stallions before and after short road transport: stress effect of different distances

    Directory of Open Access Journals (Sweden)

    Grasso Loredana

    2008-03-01

    Full Text Available Abstract Background Since transport evokes physiological adjustments that include endocrine responses, the objective of this study was to examine the responses of circulating β-endorphin, adrenocorticotrophic hormone (ACTH and cortisol levels to transport stress in stallions. Methods Forty-two healthy Thoroughbred and crossbred stallions were studied before and after road transport over distances of 100, 200 and 300 km. Blood samples were collected from the jugular vein: first in a single box immediately before loading (pre-samples, then immediately after transport and unloading on arrival at the breeding stations (post-samples. Results An increase in circulating β-endorphin levels after transport of 100 km (P P P P P > 0.05 between horses of different ages and different breeds were observed for β-endorphin, ACTH and cortisol levels. Conclusion The results obtained for short term transportation of stallions showed a very strong reaction of the adrenocortical system. The lack of response of β-endorphin after transport of 200–300 km and of ACTH after transport of 300 km seems to suggest a soothing effect of negative feedback of ACTH and cortisol levels.

  15. 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...

  16. 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...

  17. Biochemical and Hematological Changes Following the 120-Km Open-Water Marathon Swim

    Directory of Open Access Journals (Sweden)

    Wojciech Drygas, Ewa Rębowska, Ewa Stępień, Jacek Golański, Magdalena Kwaśniewska

    2014-09-01

    Full Text Available Data on physiological effects and potential risks of a ultraendurance swimming are scarce. This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim on the Warta River, Poland. Pre-swimming examinations revealed favorable conditions (blood pressure, 110/70 mmHg; rest heart rate, 54 beats/minute, ejection fraction, 60%, 20.2 metabolic equivalents in a maximal exercise test. The swimming time and distance covered were 27 h 33 min and 120 km, respectively. Blood samples for hematological and biochemical parameters were collected 30 min, 4 hrs, 10 hrs and 8 days after the swim. The body temperature of the swimmer was 36.7°C before and 35.1°C after the swim. The hematological parameters remained within the reference range in the postexercise period except for leucocytes (17.5 and 10.6 x G/l noted 30 minutes and 4 hours after the swim, respectively. Serum urea, aspartate aminotransferase and C-reactive protein increased above the reference range reaching 11.3 mmol/l, 1054 nmol/l/s and 25.9 mg/l, respectively. Symptomatic hyponatremia was not observed. Although the results demonstrate that an experienced athlete is able to complete an ultra-marathon swim without negative health consequences, further studies addressing the potential risks of marathon swimming are required.

  18. Backfitting swimming pool reactors

    International Nuclear Information System (INIS)

    Roebert, G.A.

    1978-01-01

    Calculations based on measurements in a critical assembly, and experiments to disclose fuel element surface temperatures in case of accidents like stopping of primary coolant flow during full power operation, have shown that the power of the swimming pool type research reactor FRG-2 (15 MW, operating since 1967) might be raised to 21 MW within the present rules of science and technology, without major alterations of the pool buildings and the cooling systems. A backfitting program is carried through to adjust the reactor control systems of FRG-2 and FRG-1 (5 MW, housed in the same reactor hall) to the present safety rules and recommendations, to ensure FRG-2 operation at 21 MW for the next decade. (author)

  19. Warm-up and performance in competitive swimming.

    Science.gov (United States)

    Neiva, Henrique P; Marques, Mário C; Barbosa, Tiago M; Izquierdo, Mikel; Marinho, Daniel A

    2014-03-01

    Warm-up before physical activity is commonly accepted to be fundamental, and any priming practices are usually thought to optimize performance. However, specifically in swimming, studies on the effects of warm-up are scarce, which may be due to the swimming pool environment, which has a high temperature and humidity, and to the complexity of warm-up procedures. The purpose of this study is to review and summarize the different studies on how warming up affects swimming performance, and to develop recommendations for improving the efficiency of warm-up before competition. Most of the main proposed effects of warm-up, such as elevated core and muscular temperatures, increased blood flow and oxygen delivery to muscle cells and higher efficiency of muscle contractions, support the hypothesis that warm-up enhances performance. However, while many researchers have reported improvements in performance after warm-up, others have found no benefits to warm-up. This lack of consensus emphasizes the need to evaluate the real effects of warm-up and optimize its design. Little is known about the effectiveness of warm-up in competitive swimming, and the variety of warm-up methods and swimming events studied makes it difficult to compare the published conclusions about the role of warm-up in swimming. Recent findings have shown that warm-up has a positive effect on the swimmer's performance, especially for distances greater than 200 m. We recommend that swimmers warm-up for a relatively moderate distance (between 1,000 and 1,500 m) with a proper intensity (a brief approach to race pace velocity) and recovery time sufficient to prevent the early onset of fatigue and to allow the restoration of energy reserves (8-20 min).

  20. 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...

  1. 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...

  2. Muscle Activity during Dryland Swimming while Wearing a Triathlon Wetsuit

    Directory of Open Access Journals (Sweden)

    Ciro Agnelli

    2018-01-01

    Full Text Available Background: Triathletes typically wear a wetsuit during the swim portion of an event, but it is not clear if muscle activity is influenced by wearing a wetsuit. Purpose: To investigate if shoulder muscle activity was influenced by wearing a full-sleeve wetsuit vs. no wetsuit during dryland swimming. Methods: Participants (n=10 males; 179.1±13.2 cm; 91.2±7.25 kg; 45.6±10.5 years completed two dry land swimming conditions on a swim ergometer: No Wetsuit (NW and with Wetsuit (W. Electromyography (EMG of four upper extremity muscles was recorded (Noraxon telemetry EMG, 500 Hz during each condition: Trapezius (TRAP, Triceps (TRI, Anterior Deltoid (AD and Posterior Deltoid (PD. Each condition lasted 90 seconds with data collected during the last 60 seconds. Resistance setting was self-selected and remained constant for both conditions. Stroke rate was controlled at 60 strokes per minute by having participants match a metronome. Average (AVG and Root Mean Square (RMS EMG were calculated over 45 seconds and each were compared between conditions using a paired t-test (α=0.05 for each muscle. Results: PD and AD AVG and RMS EMG were each greater (on average 40.0% and 66.8% greater, respectively during W vs. NW (p0.05. Conclusion: The greater PD and AD muscle activity while wearing a wetsuit might affect swimming performance and /or stroke technique on long distance event.

  3. Increased Prevalence of the IL-6-174C Genetic Polymorphism in Long Distance Swimmers.

    Science.gov (United States)

    Ben-Zaken, Sigal; Meckel, Yoav; Nemet, Dan; Kassem, Eias; Eliakim, Alon

    2017-09-01

    The IL-6 -174G/C single nucleotide polymorphism (SNP) functionally affects IL-6 activity, with the G-allele associated with increased IL-6 levels. The C-allele was found to be associated with exercise-induced skeletal muscle damage. The aim of the present study was to examine the association between the IL-6 -174G/C polymorphism and athletic performance among elite swimmers and runners. The study sample included 180 track and field athletes and 80 swimmers. Track and field athletes were assigned to three sub-groups: long-distance runners, middle-distance runners and short-distance runners. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. The control group consisted of 123 non-athletic healthy individuals. Genomic DNA was extracted from peripheral blood following a standard protocol. Genotyping was performed using polymerase chain reaction (PCR). The CC genotype and C-allele frequency were significantly higher in the long-distance swimmers (18 and 43%, respectively) compared to the long-distance runners (3 and 14%, respectively, p < 0.001); middle-distance runners (4 and 22%, respectively, p < 0.001); and controls (5 and 19%, respectively, p < 0.001). In addition, the CC genotype and C-allele frequency were significantly higher (p < 0.001) in long-distance swimmers compared to short-distance swimmers (18 versus 5% and 43 versus 29% for the CC genotype and C-allele frequency, respectively). The higher frequency of the C-allele and CC genotype among long-distance swimmers suggests that the rarity of exercise-associated rhabdomyolysis among swimmers is probably related to other sports-specific or water-related protective mechanisms. It is possible that swimming selection in talented endurance athletes who are C-allele carriers represents an example of genetically-dependent sports selection.

  4. Increased Prevalence of the IL-6 -174C Genetic Polymorphism in Long Distance Swimmers

    Directory of Open Access Journals (Sweden)

    Ben-Zaken Sigal

    2017-08-01

    Full Text Available The IL-6 -174G/C single nucleotide polymorphism (SNP functionally affects IL-6 activity, with the G-allele associated with increased IL-6 levels. The C-allele was found to be associated with exercise-induced skeletal muscle damage. The aim of the present study was to examine the association between the IL-6 -174G/C polymorphism and athletic performance among elite swimmers and runners. The study sample included 180 track and field athletes and 80 swimmers. Track and field athletes were assigned to three sub-groups: long-distance runners, middle-distance runners and short-distance runners. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. The control group consisted of 123 non-athletic healthy individuals. Genomic DNA was extracted from peripheral blood following a standard protocol. Genotyping was performed using polymerase chain reaction (PCR. The CC genotype and C-allele frequency were significantly higher in the long-distance swimmers (18 and 43%, respectively compared to the long-distance runners (3 and 14%, respectively, p < 0.001; middle-distance runners (4 and 22%, respectively, p < 0.001; and controls (5 and 19%, respectively, p < 0.001. In addition, the CC genotype and C-allele frequency were significantly higher (p < 0.001 in long-distance swimmers compared to short-distance swimmers (18 versus 5% and 43 versus 29% for the CC genotype and C-allele frequency, respectively. The higher frequency of the C-allele and CC genotype among long-distance swimmers suggests that the rarity of exercise-associated rhabdomyolysis among swimmers is probably related to other sports-specific or water-related protective mechanisms. It is possible that swimming selection in talented endurance athletes who are C-allele carriers represents an example of genetically-dependent sports selection.

  5. 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 ...

  6. Effect of swimming suit design on the energy demands of swimming.

    Science.gov (United States)

    Starling, R D; Costill, D L; Trappe, T A; Jozsi, A C; Trappe, S W; Goodpaster, B H

    1995-07-01

    Eight competitive male swimmers completed a standardized 365.8 m (400 yd) freestyle swimming trial at a fixed pace (approximately 90% of maximal effort) while wearing a torso swim suit (TOR) or a standard racing suit (STD). Oxygen uptake (VO2), blood lactate, heart rate (HR), and distance per stroke (DPS) measurements were obtained. In addition, a video-computer system was used to collect velocity data during a prone underwater glide following a maximal leg push-off from the side of the pool while wearing the TOR and STD suits. These data were used to calculate the total distance covered during the glides. VO2 (3.76 +/- 0.16 vs 3.92 +/- 0.18 l.min-1) and lactate (8.08 +/- 0.53 vs, 9.66 +/- 0.66 mM) were significantly (P 0.05) between the TOR (170.1 +/- 5.1 b.min-1) and STD (173.5 +/- 5.7 b.min-1) trials. DPS was significantly greater during the TOR (2.70 +/- 0.066 m.stroke-1) versus STD (2.58 +/- 0.054 m.stroke-1) trial. A significantly greater total distance was covered during the prone glide while wearing the TOR (2.05 +/- 0.067 m) compared to the STD (2.00 +/- 0.080 m) suit. These findings demonstrate that a specially designed torso suit reduces the energy demand of swimming compared to a standard racing suit which may be due to a reduction in body drag.

  7. Removal of spike frequency adaptation via neuromodulation intrinsic to the Tritonia escape swim central pattern generator.

    Science.gov (United States)

    Katz, P S; Frost, W N

    1997-10-15

    For the mollusc Tritonia diomedea to generate its escape swim motor pattern, interneuron C2, a crucial member of the central pattern generator (CPG) for this rhythmic behavior, must fire repetitive bursts of action potentials. Yet, before swimming, repeated depolarizing current pulses injected into C2 at periods similar those in the swim motor program are incapable of mimicking the firing rate attained by C2 on each cycle of a swim motor program. This resting level of C2 inexcitability is attributable to its own inherent spike frequency adaptation (SFA). Clearly, this property must be altered for the swim behavior to occur. The pathway for initiation of the swimming behavior involves activation of the serotonergic dorsal swim interneurons (DSIs), which are also intrinsic members of the swim CPG. Physiologically appropriate DSI stimulation transiently decreases C2 SFA, allowing C2 to fire at higher rates even when repeatedly depolarized at short intervals. The increased C2 excitability caused by DSI stimulation is mimicked and occluded by serotonin application. Furthermore, the change in excitability is not caused by the depolarization associated with DSI stimulation or serotonin application but is correlated with a decrease in C2 spike afterhyperpolarization. This suggests that the DSIs use serotonin to evoke a neuromodulatory action on a conductance in C2 that regulates its firing rate. This modulatory action of one CPG neuron on another is likely to play a role in configuring the swim circuit into its rhythmic pattern-generating mode and maintaining it in that state.

  8. Swimming literacy field hockey woman player ground.

    OpenAIRE

    Baštová, Miroslava

    2012-01-01

    Title: Swimming literacy field hockey woman player ground. Objectives: To obtain and analyze data on the level ground swimming literacy field hockey woman player. Their perception swimming literacy for life, the use of non-specific regeneration and as a training resource. Methods: Analysis of scientific literature, survey, case study, data analysis and graphical presentation of results. Results of the work: field hockey player as swimming literate, benefits swimming but not used as a means of...

  9. Free Swimming in Ground Effect

    Science.gov (United States)

    Cochran-Carney, Jackson; Wagenhoffer, Nathan; Zeyghami, Samane; Moored, Keith

    2017-11-01

    A free-swimming potential flow analysis of unsteady ground effect is conducted for two-dimensional airfoils via a method of images. The foils undergo a pure pitching motion about their leading edge, and the positions of the body in the streamwise and cross-stream directions are determined by the equations of motion of the body. It is shown that the unconstrained swimmer is attracted to a time-averaged position that is mediated by the flow interaction with the ground. The robustness of this fluid-mediated equilibrium position is probed by varying the non-dimensional mass, initial conditions and kinematic parameters of motion. Comparisons to the foil's fixed-motion counterpart are also made to pinpoint the effect that free swimming near the ground has on wake structures and the fluid-mediated forces over time. Optimal swimming regimes for near-boundary swimming are determined by examining asymmetric motions.

  10. 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.

  11. 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....

  12. Distance Learning

    National Research Council Canada - National Science Library

    Braddock, Joseph

    1997-01-01

    A study reviewing the existing Army Distance Learning Plan (ADLP) and current Distance Learning practices, with a focus on the Army's training and educational challenges and the benefits of applying Distance Learning techniques...

  13. Solar swimming pool

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    This report examines the feasibility of using solar collectors to heat the water in a previously unheated outdoor swimming pool. The solar system is used in conjunction with a pool blanket, to conserve heat when the pool is not in use. Energy losses through evaporation can be reduced by as much as 70% by a pool blanket. A total of 130 m{sup 2} of highly durable black synthetic collectors were installed on a support structure at a 30{degree} angle from the horizontal, oriented to the south. Circulation of pool water though the collectors, which is controlled by a differential thermostat, was done with the existing pool pump. Before installation the pool temperature averaged 16{degree}C; after installation it ranged from 20{degree} to 26{degree}C. It was hard to distinguish how much pool heating was due to the solar system and how much heat was retained by the pool blanket. However, the pool season was extended by five weeks and attendance tripled. 2 figs.

  14. 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.

  15. The Impact of Immediate Verbal Feedback on the Improvement of Swimming Technique

    Science.gov (United States)

    Zatoń, Krystyna; Szczepan, Stefan

    2014-01-01

    The present research attempts to ascertain the impact of immediate verbal feedback (IVF) on modifications of stroke length (SL). In all swimming styles, stroke length is considered an essential kinematic parameter of the swimming cycle. It is important for swimming mechanics and energetics. If SL shortens while the stroke rate (SR) remains unchanged or decreases, the temporal-spatial structure of swimming is considered erroneous. It results in a lower swimming velocity. Our research included 64 subjects, who were divided into two groups: the experimental – E (n=32) and the control – C (n=32) groups. A pretest and a post-test were conducted. The subjects swam the front crawl over the test distance of 25m at Vmax. Only the E group subjects were provided with IVF aiming to increase their SL. All tests were filmed by two cameras (50 samples•s-1). The kinematic parameters of the swimming cycle were analyzed using the SIMI Reality Motion Systems 2D software (SIMI Reality Motion Systems 2D GmbH, Germany). The movement analysis allowed to determine the average horizontal swimming velocity over 15 meters. The repeated measures analysis of variance ANOVA with a post-hoc Tukey range test demonstrated statistically significant (pswimming velocity. IVF brought about a 6.93% (Simi method) and a 5.09% (Hay method) increase in SL, as well as a 2.92% increase in swimming velocity. PMID:25114741

  16. 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).

  17. A swimming pool array for ultra high energy showers

    Science.gov (United States)

    Yodh, Gaurang B.; Shoup, Anthony; Barwick, Steve; Goodman, Jordan A.

    1992-11-01

    A very preliminary design concept for an array using water Cherenkov counters, built out of commercially available backyard swimming pools, to sample the electromagnetic and muonic components of ultra high energy showers at large lateral distances is presented. The expected performance of the pools is estimated using the observed lateral distributions by scintillator and water Cherenkov arrays at energies above 1019 eV and simulations.

  18. 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.

  19. Study of the short distance interaction between two nucleons in helium-3 and helium-4 nuclei through (e,e'p) reaction

    International Nuclear Information System (INIS)

    Le Goff, Jean-Marc

    1991-01-01

    A recent experiment has shown that it was possible to scatter inelastically on a pair of nucleons interacting at short distance inside a 3-Helium nucleus without interacting with the third nucleon. In order to study the same process in a more compact nucleus, 4-Helium, we have measured the cross section of the 4 He(e,e'p)x reaction for recoil momenta between 225 and 500 MeV/c. This experiment clearly exhibits a pair of nucleons interacting inside the 4-helium nucleus. From the kinematical point of view, the continuum shows a 'bumpy' shape, this bump shifts with increasing recoil momentum in a characteristic way. From the dynamical point of view, an overall agreement is observed between the data and a microscopic calculation, this calculation predicts that scattering on an interacting pair is the dominant process. Furthermore, above 250 MeV/c, the momentum distribution in the continuum appears very close to the momentum distribution of deuterium. In order to get a better understanding of the reaction mechanism in these measurements of high momentum, we have performed a transverse longitudinal separation of the 3 He(e,e'p)x cross section at the highest possible recoil momentum, 260 MeV/c. Since the two responses involve different couplings (respectively magnetic and coulomb coupling), this technique provides us with a very good test of our understanding of the reaction. The experimental responses have been compared to a microscopic calculation. This calculation cannot reproduce simultaneously the two responses. According to the wave function, it either slightly overestimates the longitudinal and strongly underestimates the transverse, or it clearly overestimates the longitudinal and slightly underestimates the transverse. It is interesting to consider the ratio between the integral of the longitudinal and the transverse one, since it is independent of the wave function: its theoretical value is 0.429, whereas a ratio of 0.175±0.046±0.049 is

  20. 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...... are represented in instructions for carrying out and running swimming baths. If you follow the instructions you can achieve less investments, less heat consumption and a better comfort to the bathers....

  1. Paramecium swimming in capillary tube

    Science.gov (United States)

    Jana, Saikat; Um, Soong Ho; Jung, Sunghwan

    2012-04-01

    Swimming organisms in their natural habitat need to navigate through a wide range of geometries and chemical environments. Interaction with boundaries in such situations is ubiquitous and can significantly modify the swimming characteristics of the organism when compared to ideal laboratory conditions. We study the different patterns of ciliary locomotion in glass capillaries of varying diameter and characterize the effect of the solid boundaries on the velocities of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight lines as the diameter of the capillary tubes decreases. We predict the swimming velocity in capillaries by modeling the system as a confined cylinder propagating longitudinal metachronal waves that create a finite pressure gradient. Comparing with experiments, we find that such pressure gradient considerations are necessary for modeling finite sized ciliary organisms in restrictive geometries.

  2. Optimal swimming of a sheet.

    Science.gov (United States)

    Montenegro-Johnson, Thomas D; Lauga, Eric

    2014-06-01

    Propulsion at microscopic scales is often achieved through propagating traveling waves along hairlike organelles called flagella. Taylor's two-dimensional swimming sheet model is frequently used to provide insight into problems of flagellar propulsion. We derive numerically the large-amplitude wave form of the two-dimensional swimming sheet that yields optimum hydrodynamic efficiency: the ratio of the squared swimming speed to the rate-of-working of the sheet against the fluid. Using the boundary element method, we show that the optimal wave form is a front-back symmetric regularized cusp that is 25% more efficient than the optimal sine wave. This optimal two-dimensional shape is smooth, qualitatively different from the kinked form of Lighthill's optimal three-dimensional flagellum, not predicted by small-amplitude theory, and different from the smooth circular-arc-like shape of active elastic filaments.

  3. Swimming in an Unsteady World

    Science.gov (United States)

    Koehl, M. A. R.

    2016-02-01

    When animals swim in marine habitats, the water through which they move is usually flowing. Therefore, an important part of understanding the physics of how animals swim in nature is determining how they interact with the fluctuating turbulent water currents in their environment. The research systems we have been using to address this question are microscopic marine animals swimming in turbulent, wavy water flow over spatially-complex communities of organisms growing on surfaces. Field measurements of water motion were used to design realistic turbulent flow in a laboratory wave-flume over different substrata, particle-image velocimetry was used to measure fine-scale, rapidly-varying water velocity vector fields, and planar laser-induced fluorescence was used to measure concentrations of chemical cues from the substratum. We used individual-based models of small animals swimming in this unsteady flow to determine how their trajectories and contacts with substrata were affected by their locomotion through the water, rotation by local shear, response to odors, and transport by ambient flow. We found that the shears, accelerations, and odor concentrations encountered by small swimmers fluctuate rapidly, with peaks much higher than mean values lasting fractions of a second. We identified ways in which the behavior of small, weak swimmers can bias how they are transported by ambient flow (e.g. sinking during brief encounters with shear or odor enhances settlement onto substrata below, whereas constant swimming enhances contact with surfaces above or beside larvae). Although microscopic organisms swim slowly relative to ambient water flow, their locomotory behavior in response to the rapidly-fluctuating shears and odors they encounter can affect where they are transported by ambient water movement.

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 1968 Listing of Swimming Pool Equipment.

    Science.gov (United States)

    National Sanitation Foundation, Ann Arbor, MI. Testing Lab.

    An up-to-date listing of swimming pool equipment including--(1) companies authorized to display the National Sanitation Foundation seal of approval, (2) equipment listed as meeting NSF swimming pool equipment standards relating to diatomite type filters, (3) equipment listed as meeting NSF swimming pool equipment standard relating to sand type…

  9. Undulatory fish swimming : from muscles to flow

    NARCIS (Netherlands)

    Müller, U.K.; Leeuwen, van J.L.

    2006-01-01

    Undulatory swimming is employed by many fish for routine swimming and extended sprints. In this biomechanical review, we address two questions: (i) how the fish's axial muscles power swimming; and (ii) how the fish's body and fins generate thrust. Fish have adapted the morphology of their axial

  10. 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 ...

  11. 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…

  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. Sex differences in elite swimming with advanced age are less than marathon running.

    Science.gov (United States)

    Senefeld, J; Joyner, M J; Stevens, A; Hunter, S K

    2016-01-01

    The sex difference in marathon performance increases with finishing place and age of the runner but whether this occurs among swimmers is unknown. The purpose was to compare sex differences in swimming velocity across world record place (1st-10th), age group (25-89 years), and event distance. We also compared sex differences between freestyle swimming and marathon running. The world's top 10 swimming times of both sexes for World Championship freestyle stroke, backstroke, breaststroke, and butterfly events and the world's top 10 marathon times in 5-year age groups were obtained. Men were faster than women for freestyle (12.4 ± 4.2%), backstroke (12.8 ± 3.0%), and breaststroke (14.5 ± 3.2%), with the greatest sex differences for butterfly (16.7 ± 5.5%). The sex difference in swimming velocity increased across world record place for freestyle (P swimming (P swimming increased with world record place and age, but was less than for marathon running. Collectively, these results suggest more depth in women's swimming than marathon running. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. 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:

  15. Sodium bicarbonate improves swimming performance.

    Science.gov (United States)

    Lindh, A M; Peyrebrune, M C; Ingham, S A; Bailey, D M; Folland, J P

    2008-06-01

    Sodium bicarbonate ingestion has been shown to improve performance in single-bout, high intensity events, probably due to an increase in buffering capacity, but its influence on single-bout swimming performance has not been investigated. The effects of sodium bicarbonate supplementation on 200 m freestyle swimming performance were investigated in elite male competitors. Following a randomised, double blind counterbalanced design, 9 swimmers completed maximal effort swims on 3 separate occasions: a control trial (C); after ingestion of sodium bicarbonate (SB: NaHCO3 300 mg . kg (-1) body mass); and after ingestion of a placebo (P: CaCO3 200 mg . kg (-1) body mass). The SB and P agents were packed in gelatine capsules and ingested 90 - 60 min prior to each 200 m swim. Mean 200 m performance times were significantly faster for SB than C or P (1 : 52.2 +/- 4.7; 1 : 53.7 +/- 3.8; 1 : 54.0 +/- 3.6 min : ss; p bicarbonate were all elevated pre-exercise in the SB compared to C and P trials (p < 0.05). Post-200 m blood lactate concentrations were significantly higher following the SB trial compared with P and C (p < 0.05). It was concluded that SB supplementation can improve 200 m freestyle performance time in elite male competitors, most likely by increasing buffering capacity.

  16. The hydrodynamics of swimming microorganisms

    International Nuclear Information System (INIS)

    Lauga, Eric; Powers, Thomas R

    2009-01-01

    Cell motility in viscous fluids is ubiquitous and affects many biological processes, including reproduction, infection and the marine life ecosystem. Here we review the biophysical and mechanical principles of locomotion at the small scales relevant to cell swimming, tens of micrometers and below. At this scale, inertia is unimportant and the Reynolds number is small. Our emphasis is on the simple physical picture and fundamental flow physics phenomena in this regime. We first give a brief overview of the mechanisms for swimming motility, and of the basic properties of flows at low Reynolds number, paying special attention to aspects most relevant for swimming such as resistance matrices for solid bodies, flow singularities and kinematic requirements for net translation. Then we review classical theoretical work on cell motility, in particular early calculations of swimming kinematics with prescribed stroke and the application of resistive force theory and slender-body theory to flagellar locomotion. After examining the physical means by which flagella are actuated, we outline areas of active research, including hydrodynamic interactions, biological locomotion in complex fluids, the design of small-scale artificial swimmers and the optimization of locomotion strategies.

  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. Efficient collective swimming by harnessing vortices through deep reinforcement learning.

    Science.gov (United States)

    Verma, Siddhartha; Novati, Guido; Koumoutsakos, Petros

    2018-06-05

    Fish in schooling formations navigate complex flow fields replete with mechanical energy in the vortex wakes of their companions. Their schooling behavior has been associated with evolutionary advantages including energy savings, yet the underlying physical mechanisms remain unknown. We show that fish can improve their sustained propulsive efficiency by placing themselves in appropriate locations in the wake of other swimmers and intercepting judiciously their shed vortices. This swimming strategy leads to collective energy savings and is revealed through a combination of high-fidelity flow simulations with a deep reinforcement learning (RL) algorithm. The RL algorithm relies on a policy defined by deep, recurrent neural nets, with long-short-term memory cells, that are essential for capturing the unsteadiness of the two-way interactions between the fish and the vortical flow field. Surprisingly, we find that swimming in-line with a leader is not associated with energetic benefits for the follower. Instead, "smart swimmer(s)" place themselves at off-center positions, with respect to the axis of the leader(s) and deform their body to synchronize with the momentum of the oncoming vortices, thus enhancing their swimming efficiency at no cost to the leader(s). The results confirm that fish may harvest energy deposited in vortices and support the conjecture that swimming in formation is energetically advantageous. Moreover, this study demonstrates that deep RL can produce navigation algorithms for complex unsteady and vortical flow fields, with promising implications for energy savings in autonomous robotic swarms.

  19. Physical forces shape group identity of swimming Pseudomonas putida cells

    Directory of Open Access Journals (Sweden)

    David Rodriguez-Espeso

    2016-09-01

    Full Text Available The often striking macroscopic patterns developed by motile bacterial populations on agar plates are a consequence of the environmental conditions where the cells grow and spread. Parameters such as medium stiffness and nutrient concentration have been reported to alter cell swimming behavior, while mutual interactions among populations shape collective patterns. One commonly observed occurrence is the mutual inhibition of clonal bacteria when moving towards each other, which results in a distinct halt at a finite distance on the agar matrix before having direct contact. The dynamics behind this phenomenon (i.e. intolerance to mix in time and space with otherwise identical others has been traditionally explained in terms of cell-to-cell competition/cooperation regarding nutrient availability. In this work, the same scenario has been revisited from an alternative perspective: the effect of the physical mechanics that frame the process, in particular the consequences of collisions between moving bacteria and the semi-solid matrix of the swimming medium. To this end we set up a simple experimental system in which the swimming patterns of Pseudomonas putida were tested with different geometries and agar concentrations. A computational analysis framework that highlights cell-to-medium interactions was developed to fit experimental observations. Simulated outputs suggested that the medium is compressed in the direction of the bacterial front motion. This phenomenon generates what was termed a compression wave that goes through the medium preceding the swimming population and that determines the visible high-level pattern. Taken together, the data suggested that the mechanical effects of the bacteria moving through the medium created a factual barrier that impedes to merge with neighboring cells swimming from a different site. The resulting divide between otherwise clonal bacteria is thus brought about by physical forces –not genetic or metabolic

  20. 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.

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

    Science.gov (United States)

    Palstra, Arjan P; van den Thillart, Guido E E J M

    2010-09-01

    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 approximately 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.

  2. modelling distances

    Directory of Open Access Journals (Sweden)

    Robert F. Love

    2001-01-01

    Full Text Available Distance predicting functions may be used in a variety of applications for estimating travel distances between points. To evaluate the accuracy of a distance predicting function and to determine its parameters, a goodness-of-fit criteria is employed. AD (Absolute Deviations, SD (Squared Deviations and NAD (Normalized Absolute Deviations are the three criteria that are mostly employed in practice. In the literature some assumptions have been made about the properties of each criterion. In this paper, we present statistical analyses performed to compare the three criteria from different perspectives. For this purpose, we employ the ℓkpθ-norm as the distance predicting function, and statistically compare the three criteria by using normalized absolute prediction error distributions in seventeen geographical regions. We find that there exist no significant differences between the criteria. However, since the criterion SD has desirable properties in terms of distance modelling procedures, we suggest its use in practice.

  3. Heart rate variability and swimming.

    Science.gov (United States)

    Koenig, Julian; Jarczok, Marc N; Wasner, Mieke; Hillecke, Thomas K; Thayer, Julian F

    2014-10-01

    Professionals in the domain of swimming have a strong interest in implementing research methods in evaluating and improving training methods to maximize athletic performance and competitive outcome. Heart rate variability (HRV) has gained attention in research on sport and exercise to assess autonomic nervous system activity underlying physical activity and sports performance. Studies on swimming and HRV are rare. This review aims to summarize the current evidence on the application of HRV in swimming research and draws implications for future research. A systematic search of databases (PubMed via MEDLINE, PSYNDEX and Embase) according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (a) empirical investigation (HRV) in humans (non-clinical); (b) related to swimming; (c) peer-reviewed journal; and (d) English language. The search revealed 194 studies (duplicates removed), of which the abstract was screened for eligibility. Fourteen studies meeting the inclusion criteria were included in the review. Included studies broadly fell into three classes: (1) control group designs to investigate between-subject differences (i.e. swimmers vs. non-swimmers, swimmers vs. other athletes); (2) repeated measures designs on within-subject differences of interventional studies measuring HRV to address different modalities of training or recovery; and (3) other studies, on the agreement of HRV with other measures. The feasibility and possibilities of HRV within this particular field of application are well documented within the existing literature. Future studies, focusing on translational approaches that transfer current evidence in general practice (i.e. training of athletes) are needed.

  4. 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

  5. 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.

  6. Feeding rates in the chaetognath Sagitta elegans : effects of prey size, prey swimming behaviour and small-scale turbulence

    DEFF Research Database (Denmark)

    Saito, H.; Kiørboe, Thomas

    2001-01-01

    distances. We develop a simple prey encounter rate model by describing the swimming prey as a 'force dipole' and assuming that a critical signal strength is required to elicit an attack. By fitting the model to the observations, a critical signal strength of 10(-2) cm s(-1) is estimated; this is very...... at rates up to an order of magnitude higher than similarly sized females, probably owing to differences in swimming behaviour. Sagitta elegans is an ambush predator that perceives its prey by hydromechanical signals. Faster swimming prey generates stronger signals and is, hence, perceived at longer...

  7. The SYOEKSY research project. Electrically-powered vehicles in ring rail line feeder traffic and short-distance travel; Saehkoeiset ajoneuvot kehaeradan syoettoe- ja asiointiliikenteessae. SYOEKSY-tutkimushankkeen loppuraportti 21.9.2011

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    The research report is divided into three sections: a general description of the project, separate reports on each of the themes investigated and a summary of the research results and recommendations. Section 2 deals with themes such as: Low-emissions-technology solutions for traffic and their technical prerequisites in an urban environment and the results obtained from pilot projects. New service models based on electrically-powered traffic technology with an assessment of their feasibility and their effect on urban infrastructure and levels of CO{sub 2} emissions. User needs in new feeder traffic, short-distance travel and other journeys on personal business together with proposals for planning measures which will promote sustainable mobility in new residential areas. The prerequisites for electrically-powered feeder traffic and short-distance travel are therefore handled in a wide-ranging manner. A condensed version of the project conclusions and recommendations is provided in Section 3. A list of the data sources and publications resulting from project work can be found at the end of the report

  8. Comparison of physical fitness tests in swimming

    OpenAIRE

    Dostálová, Sabina

    2015-01-01

    Title: Comparison of physical fitness tests in swimming. Objective: The aim of this thesis is to evaluate specific tests, used while testing selected physical abilities in swimming. By specific tests we mean tests realized in the water. Selected tests are intended for swim coaches, who train junior to senior age groups. Methods: The chosen method was a comparison of studies, that pursue selected specific tests. We created partial conclusions for every test by summing up the results of differe...

  9. Hydrodynamic attraction of swimming microorganisms by surfaces

    OpenAIRE

    Berke, Allison P.; Turner, Linda; Berg, Howard C.; Lauga, Eric

    2008-01-01

    Cells swimming in confined environments are attracted by surfaces. We measure the steady-state distribution of smooth-swimming bacteria (Escherichia coli) between two glass plates. In agreement with earlier studies, we find a strong increase of the cell concentration at the boundaries. We demonstrate theoretically that hydrodynamic interactions of the swimming cells with solid surfaces lead to their re-orientation in the direction parallel to the surfaces, as well as their attraction by the c...

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

    Science.gov (United States)

    2016-08-01

    ERDC/TN ANSRP-16-1 August 2016 Approved for public release; distribution is unlimited. Swimming Performance of Adult Asian Carp: Field...Assessment Using a Mobile Swim Tunnel by Jan Jeffrey Hoover, Jay A. Collins, Alan W. Katzenmeyer, and K. Jack Killgore PURPOSE: Empirical swim speed...test in traditional laboratory swim tunnels. Biologists from the Engineer Research and Development Center (ERDC) Environmental Laboratory (EL), with

  11. Antidepressant-like effects of nicotine and mecamylamine in the mouse forced swim and tail suspension tests: role of strain, test and sex

    DEFF Research Database (Denmark)

    Andreasen T., Jesper; Redrobe, John P

    2009-01-01

    , but not mecamylamine, increased swim distance in C57BL/6J mice. Both drugs increased swim distance in BALB/c mice. Effects in the mFST were independent of sex. In the mTST, mecamylamine decreased immobility in NMRI mice only, independent of sex. Nicotine was devoid of effects in the mTST, except in female C57BL/6J...

  12. 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...

  13. 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.

  14. The backstroke swimming start: state of the art.

    Science.gov (United States)

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

    2014-09-29

    As sprint swimming events can be decided by margins as small as .01 s, thus, an effective start is essential. This study reviews and discusses the 'state of the art' literature regarding backstroke start biomechanics from 23 documents. 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 of Biomechanics in Sports Conference Proceedings, one from a Biomechanics Congress and one academic (PhD) thesis. The studies had diverse aims, including swimmers' proficiency levels and data collection settings. There was no single consensus for defining phase descriptions; and kinematics, kinetics and EMG approaches were implemented in laboratory settings. However, researchers face great challenges in improving methods of quantifying valid, reliable and accurate data between laboratory and competition conditions. For example, starting time was defined from the starting signal to distances as disparate as ∼5 m to 22.86 m in several studies. Due to recent rule changes, some of the research outcomes now refer to obsolete backstroke start techniques, and only a few studies considered the actual international rules. This literature review indicated that further research is required, in both laboratory and competition settings focusing on the combined influences of the current rules and block configuration on backstroke starting performances.

  15. Coordination of multiple appendages in drag-based swimming.

    Science.gov (United States)

    Alben, Silas; Spears, Kevin; Garth, Stephen; Murphy, David; Yen, Jeannette

    2010-11-06

    Krill are aquatic crustaceans that engage in long distance migrations, either vertically in the water column or horizontally for 10 km (over 200,000 body lengths) per day. Hence efficient locomotory performance is crucial for their survival. We study the swimming kinematics of krill using a combination of experiment and analysis. We quantify the propulsor kinematics for tethered and freely swimming krill in experiments, and find kinematics that are very nearly metachronal. We then formulate a drag coefficient model which compares metachronal, synchronous and intermediate motions for a freely swimming body with two legs. With fixed leg velocity amplitude, metachronal kinematics give the highest average body speed for both linear and quadratic drag laws. The same result holds for five legs with the quadratic drag law. When metachronal kinematics is perturbed towards synchronous kinematics, an analysis shows that the velocity increase on the power stroke is outweighed by the velocity decrease on the recovery stroke. With fixed time-averaged work done by the legs, metachronal kinematics again gives the highest average body speed, although the advantage over synchronous kinematics is reduced.

  16. Academic integration of university students as a determining factor of student dropout in the short term. An analysis of the distance education system in Ecuador

    Directory of Open Access Journals (Sweden)

    Luis Fabian Moncada Mora

    2014-06-01

    Full Text Available This study addresses the problem of the abandonment (dropout of university students from the point of view of their level of integration. This approach is used with the aim of locating the factor(s that provide(s the greatest amount of information regarding the decision to continue or to abandon one’s studies. The theoretical characterization of this phenomenon has become one of the underlying factors that are used to explain the theory behind students dropping out of their courses. Based on this theory, we can determine the incidence of student drop out, and determine the (high incidence, where immediate results serve as a means of measuring academic integration and the decision to continue or to quit one’s studies. Statistical information is grouped in such a way that it is possible to follow the guidelines and expectations outlined in the theory and also helps us to understand typical characteristics of this phenomenon. To generate empirical evidence, we worked with data from 6,715 students, who belonged to the April-August 2012 group at the Universidad Técnica Particular de Loja,  which represents 82% of the student population of Ecuador enrolled in the distance learning system. Evidence for this study was obtained from the following sources: first, there was a description of the data and an application of the characterization process. In this phase, it was determined that 40.6% of students dropped out for academic reasons; 8.9% dropped out for non-academic reasons; 32.6% stayed for academic reasons; and 17.5% remained for non-academic reasons. Second, we estimated probabilistic models that confirmed the negative relationship between the immediate results (calculated as an average of academic integration and factors concerning the decision to quit one’s studies.

  17. Unsteady turbulent boundary layers in swimming rainbow trout.

    Science.gov (United States)

    Yanase, Kazutaka; Saarenrinne, Pentti

    2015-05-01

    The boundary layers of rainbow trout, Oncorhynchus mykiss, swimming at 1.02±0.09 L s(-1) (mean±s.d., N=4), were measured by the particle image velocimetry (PIV) technique at a Reynolds number of 4×10(5). The boundary layer profile showed unsteadiness, oscillating above and beneath the classical logarithmic law of the wall with body motion. Across the entire surface regions that were measured, local Reynolds numbers based on momentum thickness, which is the distance that is perpendicular to the fish surface through which the boundary layer momentum flows at free-stream velocity, were greater than the critical value of 320 for the laminar-to-turbulent transition. The skin friction was dampened on the convex surface while the surface was moving towards a free-stream flow and increased on the concave surface while retreating. These observations contradict the result of a previous study using different species swimming by different methods. Boundary layer compression accompanied by an increase in local skin friction was not observed. Thus, the overall results may not support absolutely the Bone-Lighthill boundary layer thinning hypothesis that the undulatory motions of swimming fish cause a large increase in their friction drag because of the compression of the boundary layer. In some cases, marginal flow separation occurred on the convex surface in the relatively anterior surface region, but the separated flow reattached to the fish surface immediately downstream. Therefore, we believe that a severe impact due to induced drag components (i.e. pressure drag) on the swimming performance, an inevitable consequence of flow separation, was avoided. © 2015. Published by The Company of Biologists Ltd.

  18. Short fusion

    CERN Multimedia

    2002-01-01

    French and UK researchers are perfecting a particle accelerator technique that could aid the quest for fusion energy or make X-rays that are safer and produce higher-resolution images. Led by Dr Victor Malka from the Ecole Nationale Superieure des Techniques Avancees in Paris, the team has developed a better way of accelerating electrons over short distances (1 page).

  19. 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

  20. 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…

  1. 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

  2. Strouhal number for free swimming

    Science.gov (United States)

    Saadat, Mehdi; van Buren, Tyler; Floryan, Daniel; Smits, Alexander; Haj-Hariri, Hossein

    2015-11-01

    In this work, we present experimental results to explore the implications of free swimming for Strouhal number (as an outcome) in the context of a simple model for a fish that consists of a 2D virtual body (source of drag) and a 2D pitching foil (source of thrust) representing cruising with thunniform locomotion. The results validate the findings of Saadat and Haj-Hariri (2012): for pitching foils thrust coefficient is a function of Strouhal number for all gaits having amplitude less than a certain critical value. Equivalently, given the balance of thrust and drag forces at cruise, Strouhal number is only a function of the shape, i.e. drag coefficient and area, and essentially a constant for high enough swimming speeds for which the mild dependence of drag coefficient on the speed vanishes. Furthermore, a dimensional analysis generalizes the findings. A scaling analysis shows that the variation of Strouhal number with cruising speed is functionally related to the variation of body drag coefficient with speed. Supported by ONR MURI Grant N00014-14-1-0533.

  3. Swimming

    Science.gov (United States)

    ... back on them. Then you'll know what's coming. Water Parks Kids love water parks — and why shouldn't they? Wave pools, giant slides, and squirting fountains are a lot of fun. To stay safe, find out what each attraction is like and how deep the water is. ...

  4. swimming

    Science.gov (United States)

    Locations Recycling Sludge/Biosolids Solid Waste Watershed Protection Nonpoint Source Pollution Total Watershed Protection Wellhead Protection Funding Water and Waste Funding Drinking Water Funding Sanitary and Permit Oil and Gas Waste Management Water Rights All Permits/Forms (Alphabetical) All Permits/Forms (by

  5. Distance learning

    Directory of Open Access Journals (Sweden)

    Katarina Pucelj

    2006-12-01

    Full Text Available I would like to underline the role and importance of knowledge, which is acquired by individuals as a result of a learning process and experience. I have established that a form of learning, such as distance learning definitely contributes to a higher learning quality and leads to innovative, dynamic and knowledgebased society. Knowledge and skills enable individuals to cope with and manage changes, solve problems and also create new knowledge. Traditional learning practices face new circumstances, new and modern technologies appear, which enable quick and quality-oriented knowledge implementation. The centre of learning process at distance learning is to increase the quality of life of citizens, their competitiveness on the workforce market and ensure higher economic growth. Intellectual capital is the one, which represents the biggest capital of each society and knowledge is the key factor for succes of everybody, who are fully aware of this. Flexibility, openness and willingness of people to follow new IT solutions form suitable environment for developing and deciding to take up distance learning.

  6. Swimming of the Honey Bees

    Science.gov (United States)

    Roh, Chris; Gharib, Morteza

    2016-11-01

    When the weather gets hot, nursing honey bees nudge foragers to collect water for thermoregulation of their hive. While on their mission to collect water, foragers sometimes get trapped on the water surface, forced to interact with a different fluid environment. In this study, we present the survival strategy of the honey bees at the air-water interface. A high-speed videography and shadowgraph were used to record the honey bees swimming. A unique thrust mechanism through rapid vibration of their wings at 60 to 150 Hz was observed. This material is based upon work supported by the National Science Foundation under Grant No. CBET-1511414; additional support by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469.

  7. 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.

  8. Krill (Meganyctiphanes norvegica) swim faster at night

    KAUST Repository

    Klevjer, Thor A.; Kaartvedt, Stein

    2011-01-01

    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.

  9. Comparison of Effect of Two Methods of Face-to-Face Education and Distance Education (via Short Message Service on Amount of Following Remedial Diet in Patients Suffering From Hypertension

    Directory of Open Access Journals (Sweden)

    Basiri

    2016-04-01

    Full Text Available Background A large amount of money is allocated to hypertension in terms of remedial and care costs, but fighting against this disease begins with education. Objectives This study has been conducted with the aim of comparing the effect of two methods: face-to-face education and distance education (via short message service [SMS] on amount of following remedial diet in patients suffering from hypertension. Patients and Methods In this clinical trial study, 72 patients who were suffering from hypertension participated. They were selected by the purposeful sampling from three hospitals in Abadan city, Iran. Each of the three groups were similar in terms of age, gender, level of education, marital status, and duration of suffering from hypertension. The first group was under face-to-face education for eight sessions of 30 minutes; the second group under distance education (via SMS; and the third group did not receive any education as they were the control group. The tools used for collecting data involved three questionnaires (demographic data [two parts], following medicinal diet (three parts: MMAS-3, therapeutic lifestyle changes, and dietary approach to stop hypertension, and evaluating the amount of patients’ awareness about their disease. This study applied descriptive and deductive statistics with SPSS Version 20 for statistical analysis. Results The results showed that the mean of examined realms, after interference in both the face-to-face and the distance education groups, had a significant statistical difference with the before-interference mean (P = 0.0001. Inter-group comparison between systolic and diastolic blood pressure and awareness realms showed that there was a significant statistical difference between the face-to-face education group compared with the control group (P < 0.05. However, in other realms, no significant statistical difference was observed between the two educational groups (P < 0.05. Conclusions Having access to

  10. Effects of Microphallus turgidus (Trematoda: Microphallidae) on the predation, behavior, and swimming stamina of the grass shrimp Palaemonetes pugio.

    Science.gov (United States)

    Kunz, Alyssa K; Pung, Oscar J

    2004-06-01

    The effect of the trematode Microphallus turgidus on its second intermediate host, the grass shrimp, Palaemonetes pugio, was tested. To do so, we measured the susceptibility of infected and uninfected shrimp to predation by the mummichog, Fundulus heteroclitus. Shrimp behavior was compared in the presence and absence of a fish predator, and the swimming stamina and backthrust escape responses of infected and uninfected shrimp were measured. Infected shrimp were more likely to be eaten by a predator than uninfected shrimp, had lower swimming stamina, and spent more time swimming and less time motionless in the presence of a predator. There was no difference between backthrust distances traveled in response to a stimulus by either infected or uninfected shrimp. Thus, M. turgidus may increase the predation of P. pugio in the wild, possibly by affecting the swimming stamina and predator avoidance responses of the shrimp.

  11. Dynamic states of swimming bacteria in a nematic liquid crystal cell with homeotropic alignment

    International Nuclear Information System (INIS)

    Zhou, Shuang; Harvard University, Cambridge, MA; Tovkach, Oleh; University of Massachusetts, Amherst, MA; Golovaty, Dmitry

    2017-01-01

    Flagellated bacteria such as Escherichia coli and Bacillus subtilis exhibit effective mechanisms for swimming in fluids and exploring the surrounding environment. In isotropic fluids such as water, the bacteria change swimming direction through the run-and-tumble process. Lyotropic chromonic liquid crystals (LCLCs) have been introduced recently as an anisotropic environment in which the direction of preferred orientation, the director, guides the bacterial trajectories. In this work, we describe the behavior of bacteria B. subtilis in a homeotropic LCLC geometry, in which the director is perpendicular to the bounding plates of a shallow cell. We demonstrate that the bacteria are capable of overcoming the stabilizing elastic forces of the LCLC and swim perpendicularly to the imposed director (and parallel to the bounding plates). The effect is explained by a finite surface anchoring of the director at the bacterial body; the role of surface anchoring is analyzed by numerical simulations of a rod realigning in an otherwise uniform director field. Shear flows produced by a swimming bacterium cause director distortions around its body, as evidenced both by experiments and numerical simulations. These distortions contribute to a repulsive force that keeps the swimming bacterium at a distance of a few micrometers away from the bounding plates. The homeotropic alignment of the director imposes two different scenarios of bacterial tumbling: one with an 180° reversal of the horizontal velocity and the other with the realignment of the bacterium by two consecutive 90° turns. Finally, in the second case, the angle between the bacterial body and the imposed director changes from 90° to 0° and then back to 90°; the new direction of swimming does not correlate with the previous swimming direction.

  12. 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.

  13. A Review of Swimming Cues and Tips for Physical Education

    Science.gov (United States)

    Higginson, Kelsey; Barney, David

    2016-01-01

    Swimming is a low-impact activity that causes little stress on joints so it can be done for a lifetime. Many teachers may wish to teach swimming but do not have cues or ideas for doing so. This article reviews swimming cues, relays and equipment that can help a physical education teacher include a swimming unit in their curriculum. Certification…

  14. 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...

  15. Guide for decontaminating swimming pool at schools

    International Nuclear Information System (INIS)

    Matsuhashi, Shimpei; Kurikami, Hiroshi; Yasuda, Ryo; Takano, Takao; Seko, Noriaki; Naganawa, Hirochika; Kuroki, Ryota; Saegusa, Jun

    2012-07-01

    Because of TEPCO Fukushima Dai-ichi Nuclear Power Plant accident due to the Great East Japan Earthquake, a huge amount of radioactive materials was widely dispersed and precipitated into the environment. Swimming pools in Fukushima prefectures were contaminated with the radioactives. We JAEA carried out several demonstration tests to decontaminate the radioactives and discharge the pool water safely. We concluded the results obtained from the tests as 'Guide for decontaminating Swimming Pool at School' and released it quickly. Following this, we also released the guide in English. This manuscript, as an experimental report of the swimming pool water decontamination, is consisted from the guide in Japanese and English prepared. (author)

  16. Guide for decontaminating swimming pool at schools

    Energy Technology Data Exchange (ETDEWEB)

    Matsuhashi, Shimpei; Kurikami, Hiroshi; Yasuda, Ryo; Takano, Takao; Seko, Noriaki; Naganawa, Hirochika; Kuroki, Ryota; Saegusa, Jun

    2012-07-15

    Because of TEPCO Fukushima Dai-ichi Nuclear Power Plant accident due to the Great East Japan Earthquake, a huge amount of radioactive materials was widely dispersed and precipitated into the environment. Swimming pools in Fukushima prefectures were contaminated with the radioactives. We JAEA carried out several demonstration tests to decontaminate the radioactives and discharge the pool water safely. We concluded the results obtained from the tests as 'Guide for decontaminating Swimming Pool at School' and released it quickly. Following this, we also released the guide in English. This manuscript, as an experimental report of the swimming pool water decontamination, is consisted from the guide in Japanese and English prepared. (author)

  17. 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).

  18. Short distance neutrino oscillations with Borexino

    Directory of Open Access Journals (Sweden)

    Caminata A.

    2016-01-01

    Full Text Available The Borexino detector has convincingly shown its outstanding performances in the low energy, sub-MeV regime through its unprecedented accomplishments in the solar and geo-neutrinos detection. These performances make it the ideal tool to accomplish a state-of-the-art experiment able to test unambiguously the long-standing issue of the existence of a sterile neutrino, as suggested by the several anomalous results accumulated over the past two decades, i.e. the outputs of the LSND and Miniboone experiments, the results of the source calibration of the two Gallium solar neutrino experiments, and the recently hinted reactor anomaly. The SOX project will exploit two sources, based on Chromium and Cerium, respectively, which deployed under the experiment, in a location foreseen on purpose at the time of the construction of the detector, will emit two intense beams of neutrinos (Cr and anti-neutrinos (Ce. Interacting in the active volume of the liquid scintillator, each beam would create an unmistakable spatial wave pattern in case of oscillation of the νe (or ν̅e into the sterile state: such a pattern would be the smoking gun proving the existence of the new sterile member of the neutrino family. Otherwise, its absence will allow setting a very stringent limit on its existence.

  19. Anagrus breviphragma Soyka Short Distance Search Stimuli

    Directory of Open Access Journals (Sweden)

    Elisabetta Chiappini

    2015-01-01

    Full Text Available Anagrus breviphragma Soyka (Hymenoptera: Mymaridae successfully parasitises eggs of Cicadella viridis (L. (Homoptera: Cicadellidae, embedded in vegetal tissues, suggesting the idea of possible chemical and physical cues, revealing the eggs presence. In this research, three treatments were considered in order to establish which types of cue are involved: eggs extracted from leaf, used as a control, eggs extracted from leaf and cleaned in water and ethanol, used to evaluate the presence of chemicals soluble in polar solvents, and eggs extracted from leaf and covered with Parafilm (M, used to avoid physical stimuli due to the bump on the leaf surface. The results show that eggs covered with Parafilm present a higher number of parasitised eggs and a lower probing starting time with respect to eggs washed with polar solvents or eggs extracted and untreated, both when the treatments were singly tested or when offered in sequence, independently of the treatment position. These results suggest that the exploited stimuli are not physical due to the bump but chemicals that can spread in the Parafilm, circulating the signal on the whole surface, and that the stimuli that elicit probing and oviposition are not subjected to learning.

  20. Ideas on hadronic physics at short distances

    International Nuclear Information System (INIS)

    Preparata, G.

    1989-01-01

    The ideas underlying Perturbative QCD and its rival theory ACD/QGD, that has been developed by the author with a number of collaborators, are described and confronted upon an anthology of experimental data in e + e - annihilation, deep inelastic scattering and high p T physics. (author). 32 refs.; 20 figs.; 1 tab

  1. Factors influencing termination of swimming career of children at sport swimming classes

    OpenAIRE

    Pištěková, Petra

    2007-01-01

    Title: The Cause ofan Early End ofPupils' Swimming Career The aim of the thesis: Determination ofthe most frequent reasons for an early end ofpupils' swimming career. Method: The reasons for an early end ofpupils' swimming career were discovered by using questionnaires. Forty-five former pupils from special sports elementary schools were questioned and then the data were compared with available literature. Results: Research investigated changes in the most frequent reasons for an early end of...

  2. Analysis of Sport Nutrition and Diet for Swimming Athletes

    OpenAIRE

    Jun An

    2014-01-01

    This current study analyzed nutrition and dietary structure of swimming athletes to clarify issues in nutrition and dietary structure of swimming athletes, based on which we designed achievable nutrition and diet strategies to equip the swimming athletes with the tools to achieve an adequate sport nutrition which helps them improve results. Firstly, we collected literatures about nutrition and diet of swimming athletes. Secondly, 40 swimming athletes were assigned to the test group and the co...

  3. 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.

  4. 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...... 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...... constant cross-section of red muscle along much of the body suggests that positive power for swimming is generated fairly uniformly along the length of the fish....

  5. 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...

  6. Swimming of Paramecium in confined channels

    Science.gov (United States)

    Jung, Sunghwan

    2012-02-01

    Many living organisms in nature have developed a few different swimming modes, presumably derived from hydrodynamic advantage. Paramecium is a ciliated protozoan covered by thousands of cilia with a few nanometers in diameter and tens of micro-meters in length and is able to exhibit both ballistic and meandering motions. First, we characterize ballistic swimming behaviors of ciliated microorganisms in glass capillaries of different diameters and explain the trajectories they trace out. We develop a theoretical model of an undulating sheet with a pressure gradient and discuss how it affects the swimming speed. Secondly, investigation into meandering swimmings within rectangular PDMS channels of dimension smaller than Paramecium length. We find that Paramecium executes a body-bend (an elastic buckling) using the cilia while it meanders. By considering an elastic beam model, we estimate and show the universal profile of forces it exerts on the walls. Finally, we discuss a few other locomotion of Paramecium in other extreme environments like gel.

  7. 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.

  8. Anisotropic swim stress in active matter with nematic order

    Science.gov (United States)

    Yan, Wen; Brady, John F.

    2018-05-01

    Active Brownian particles (ABPs) transmit a swim pressure {{{\\Pi }}}{{swim}}=n\\zeta {D}{{swim}} to the container boundaries, where ζ is the drag coefficient, D swim is the swim diffusivity and n is the uniform bulk number density far from the container walls. In this work we extend the notion of the isotropic swim pressure to the anisotropic tensorial swim stress {{\\boldsymbol{σ }}}{{swim}}=-n\\zeta {{\\boldsymbol{D}}}{{swim}}, which is related to the anisotropic swim diffusivity {{\\boldsymbol{D}}}{{swim}}. We demonstrate this relationship with ABPs that achieve nematic orientational order via a bulk external field. The anisotropic swim stress is obtained analytically for dilute ABPs in both 2D and 3D systems. The anisotropy, defined as the ratio of the maximum to the minimum of the three principal stresses, is shown to grow exponentially with the strength of the external field. We verify that the normal component of the anisotropic swim stress applies a pressure {{{\\Pi }}}{{swim}}=-({{\\boldsymbol{σ }}}{{swim}}\\cdot {\\boldsymbol{n}})\\cdot {\\boldsymbol{n}} on a wall with normal vector {\\boldsymbol{n}}, and, through Brownian dynamics simulations, this pressure is shown to be the force per unit area transmitted by the active particles. Since ABPs have no friction with a wall, the difference between the normal and tangential stress components—the normal stress difference—generates a net flow of ABPs along the wall, which is a generic property of active matter systems.

  9. Does the hearing sensitivity in thorny catfishes depend on swim bladder morphology?

    Directory of Open Access Journals (Sweden)

    Angelika Zebedin

    Full Text Available BACKGROUND: Thorny catfishes exhibit large variations in swim bladder morphology. These organs are of different sizes, forms and may have simple or branched diverticula. The swim bladder plays an important role in otophysans because it enhances their hearing sensitivity by transmitting sound pressure fluctuations via ossicles to the inner ear. METHODOLOGY/PRINCIPAL FINDINGS: To investigate if a form-function relationship exists, the swim bladder morphology and hearing ability were analyzed in six species. The morphology was quantified by measuring the length, width and height and calculating a standardized swim bladder length (sSBL, which was then used to calculate the relative swim bladder length (rSBL. Hearing was measured using the auditory evoked potential (AEP recording technique. Two species had simple apple-shaped and four species heart-shaped (cordiform bladders. One of the latter species had short unbranched diverticula on the terminal margin, two had a secondary bladder and two had many long, branched diverticula. The rSBL differed significantly between most of the species. All species were able to detect frequencies between 70 Hz and 6 kHz, with lowest thresholds found between 0.5 and 1 kHz (60 dB re 1 µPa. Hearing curves were U-shaped except in Hemidoras morrisi in which it was ramp-like. Mean hearing thresholds of species possessing smaller rSBLs were slightly lower (maximum 8.5 dB than those of species having larger rSBLs. CONCLUSIONS/SIGNIFICANCE: The current findings reveal a relationship between swim bladder form and its function among thorny catfishes. Relatively smaller swim bladders resulted in relatively better hearing. This is in contrast to a prior inter-familial study on catfishes in which species with large unpaired bladders possessed higher sensitivity at higher frequencies than species having tiny paired and encapsulated bladders.

  10. Attempts to retreat from a dead-ended long capillary by backward swimming in Paramecium

    Directory of Open Access Journals (Sweden)

    Itsuki eKunita

    2014-06-01

    Full Text Available We have observed how the ciliate Paramecium attempts to retreat from the dead-end of a long capillary that is too narrow for turning. After many trial-and-error episodes of short-term backward swimming (SBS, which is the conventional avoidance behavior exhibited in free swimming when an obstacle is faced, long-term backward swimming (LBS that lasted five to ten times longer was developed. LBS may have a beneficial effect for complete withdrawal from the capillary space, although in our experiment it was impossible for the organism to do so due to the capillary length. In order to identify a physically possible mechanism for LBS, we propose model equations for the membrane potential of Hodgkin-Huxley type, which describe the control of ciliary movement. The physiological implications and physical mechanism of the development of LBS are discussed.

  11. Relative Contribution of Arms and Legs in 30 s Fully Tethered Front Crawl Swimming

    Directory of Open Access Journals (Sweden)

    Pedro G. Morouço

    2015-01-01

    Full Text Available The relative contribution of arm stroke and leg kicking to maximal fully tethered front crawl swimming performance remains to be solved. Twenty-three national level young swimmers (12 male and 11 female randomly performed 3 bouts of 30 s fully tethered swimming (using the whole body, only the arm stroke, and only the leg kicking. A load-cell system permitted the continuous measurement of the exerted forces, and swimming velocity was calculated from the time taken to complete a 50 m front crawl swim. As expected, with no restrictions swimmers were able to exert higher forces than that using only their arm stroke or leg kicking. Estimated relative contributions of arm stroke and leg kicking were 70.3% versus 29.7% for males and 66.6% versus 33.4% for females, with 15.6% and 13.1% force deficits, respectively. To obtain higher velocities, male swimmers are highly dependent on the maximum forces they can exert with the arm stroke (r=0.77, P<0.01, whereas female swimmers swimming velocity is more related to whole-body mean forces (r=0.81, P<0.01. The obtained results point that leg kicking plays an important role over short duration high intensity bouts and that the used methodology may be useful to identify strength and/or coordination flaws.

  12. Feasibility of Using a Novel 2.45 GHz Double Short Distance Slot Coaxial Antenna for Minimally Invasive Cancer Breast Microwave Ablation Therapy: Computational Model, Phantom, and In Vivo Swine Experimentation

    Science.gov (United States)

    Cepeda Rubio, M. F. J.; Leija, L.

    2018-01-01

    Microwave ablation (MWA) by using coaxial antennas is a promising alternative for breast cancer treatment. A double short distance slot coaxial antenna as a newly optimized applicator for minimally invasive treatment of breast cancer is proposed. To validate and to analyze the feasibility of using this method in clinical treatment, a computational model, phantom, and breast swine in vivo experimentation were carried out, by using four microwave powers (50 W, 30 W, 20 W, and 10 W). The finite element method (FEM) was used to develop the computational model. Phantom experimentation was carried out in breast phantom. The in vivo experimentation was carried out in a 90 kg swine sow. Tissue damage was estimated by comparing control and treated micrographs of the porcine mammary gland samples. The coaxial slot antenna was inserted in swine breast glands by using image-guided ultrasound. In all cases, modeling, in vivo and phantom experimentation, and ablation temperatures (above 60°C) were reached. The in vivo experiments suggest that this new MWA applicator could be successfully used to eliminate precise and small areas of tissue (around 20–30 mm2). By modulating the power and time applied, it may be possible to increase/decrease the ablation area. PMID:29854360

  13. Gastrointestinal illness among triathletes swimming in non-polluted versus polluted seawater affected by heavy rainfall, Denmark, 2010-2011.

    Directory of Open Access Journals (Sweden)

    Nina Majlund Harder-Lauridsen

    Full Text Available Recent years have seen an increase in the frequency of extreme rainfall and subsequent flooding across the world. Climate change models predict that such flooding will become more common, triggering sewer overflows, potentially with increased risks to human health. In August 2010, a triathlon sports competition was held in Copenhagen, Denmark, shortly after an extreme rainfall. The authors took advantage of this event to investigate disease risks in two comparable cohorts of physically fit, long distance swimmers competing in the sea next to a large urban area. An established model of bacterial concentration in the water was used to examine the level of pollution in a spatio-temporal manner. Symptoms and exposures among athletes were examined with a questionnaire using a retrospective cohort design and the questionnaire investigation was repeated after a triathlon competition held in non-polluted seawater in 2011. Diagnostic information was collected from microbiological laboratories. The results showed that the 3.8 kilometer open water swimming competition coincided with the peak of post-flooding bacterial contamination in 2010, with average concentrations of 1.5x10(4 E. coli per 100 ml water. The attack rate of disease among 838 swimmers in 2010 was 42% compared to 8% among 931 swimmers in the 2011 competition (relative risk (RR 5.0; 95% CI: 4.0-6.39. In 2010, illness was associated with having unintentionally swallowed contaminated water (RR 2.5; 95% CI: 1.8-3.4; and the risk increased with the number of mouthfuls of water swallowed. Confirmed aetiologies of infection included Campylobacter, Giardia lamblia and diarrhoeagenic E. coli. The study demonstrated a considerable risk of illness from water intake when swimming in contaminated seawater in 2010, and a small but measureable risk from non-polluted water in 2011. This suggests a significant risk of disease in people ingesting small amounts of flood water following extreme rainfall in

  14. Gastrointestinal illness among triathletes swimming in non-polluted versus polluted seawater affected by heavy rainfall, Denmark, 2010-2011.

    Science.gov (United States)

    Harder-Lauridsen, Nina Majlund; Kuhn, Katrin Gaardbo; Erichsen, Anders Christian; Mølbak, Kåre; Ethelberg, Steen

    2013-01-01

    Recent years have seen an increase in the frequency of extreme rainfall and subsequent flooding across the world. Climate change models predict that such flooding will become more common, triggering sewer overflows, potentially with increased risks to human health. In August 2010, a triathlon sports competition was held in Copenhagen, Denmark, shortly after an extreme rainfall. The authors took advantage of this event to investigate disease risks in two comparable cohorts of physically fit, long distance swimmers competing in the sea next to a large urban area. An established model of bacterial concentration in the water was used to examine the level of pollution in a spatio-temporal manner. Symptoms and exposures among athletes were examined with a questionnaire using a retrospective cohort design and the questionnaire investigation was repeated after a triathlon competition held in non-polluted seawater in 2011. Diagnostic information was collected from microbiological laboratories. The results showed that the 3.8 kilometer open water swimming competition coincided with the peak of post-flooding bacterial contamination in 2010, with average concentrations of 1.5x10(4) E. coli per 100 ml water. The attack rate of disease among 838 swimmers in 2010 was 42% compared to 8% among 931 swimmers in the 2011 competition (relative risk (RR) 5.0; 95% CI: 4.0-6.39). In 2010, illness was associated with having unintentionally swallowed contaminated water (RR 2.5; 95% CI: 1.8-3.4); and the risk increased with the number of mouthfuls of water swallowed. Confirmed aetiologies of infection included Campylobacter, Giardia lamblia and diarrhoeagenic E. coli. The study demonstrated a considerable risk of illness from water intake when swimming in contaminated seawater in 2010, and a small but measureable risk from non-polluted water in 2011. This suggests a significant risk of disease in people ingesting small amounts of flood water following extreme rainfall in urban areas.

  15. Evaluation of swimming capability and potential velocity barrier problems for fish. Part A: Swimming performance of selected warm and cold water fish species relative to fish passage and fishway design

    International Nuclear Information System (INIS)

    Scruton, D. A.; Goosney, R. G.; McKinley, R. S.; Booth, R. K.; Peake, S.

    1998-08-01

    The objective of this study was to provide information about the swimming capability of several widely distributed, economically or recreationally important fish species, for use in mitigating potential velocity barrier problems associated with hydroelectric power facilities. Swimming capability of anadromous and landlocked Atlantic salmon, brook trout, brown trout, lake sturgeon, and walleye, collected from various locations throughout Canada, were investigated to develop criteria for sustained, prolonged, burst swimming performance characteristics of the study species, fish physiology, life history and migration distance on swimming performance. Swimming performance characteristics in the wild, especially the use of physiological telemetry, as well as development of new methodology for the measurement of burst speed was also central to the study. Models were derived to describe swimming capabilities for each study species/life stage in relation to fish length, water velocity, water temperature, and other significant environmental factors. The data will form the basis of guideline development and decision making to improve design and evaluation of fish passage facilities. A series of annotated bibliographies resulting from the study are described in Appendix B. 74 refs., 8 tabs., figs., 2 appendices

  16. Determination of n, γ radiation field around the building of the swimming-pool reactor

    International Nuclear Information System (INIS)

    Jiang Jinling; Wen Youqin; Chen Changmao

    1986-01-01

    This work has measured the dose distribution of n, gamma radiation field around the building of the swimming-pool reactor by use of the highly sensitive neutron Rem counter and PTB-H 7907 exposure ratemeter. The measured datum show that the maximum value of n, gamma dose are 3-4 times greater than the background on certain distance from the building. Generally, the neutron doses are 2-3 times larger than gamma doses on most points

  17. Energetic and biomechanical constraints on animal migration distance.

    Science.gov (United States)

    Hein, Andrew M; Hou, Chen; Gillooly, James F

    2012-02-01

    Animal migration is one of the great wonders of nature, but the factors that determine how far migrants travel remain poorly understood. We present a new quantitative model of animal migration and use it to describe the maximum migration distance of walking, swimming and flying migrants. The model combines biomechanics and metabolic scaling to show how maximum migration distance is constrained by body size for each mode of travel. The model also indicates that the number of body lengths travelled by walking and swimming migrants should be approximately invariant of body size. Data from over 200 species of migratory birds, mammals, fish, and invertebrates support the central conclusion of the model - that body size drives variation in maximum migration distance among species through its effects on metabolism and the cost of locomotion. The model provides a new tool to enhance general understanding of the ecology and evolution of migration. © 2011 Blackwell Publishing Ltd/CNRS.

  18. Effect of fastskin suits on performance, drag, and energy cost of swimming.

    Science.gov (United States)

    Chatard, Jean-Claude; Wilson, Barry

    2008-06-01

    To investigate the effect of fastskin suits on 25- to 800-m performances, drag, and energy cost of swimming. The performances, stroke rate and distance per stroke, were measured for 14 competitive swimmers in a 25-m pool, when wearing a normal suit (N) and when wearing a full-body suit (FB) or a waist-to-ankle suit (L). Passive drag, oxygen uptake, blood lactate, and the perceived exertion were measured in a flume. There was a 3.2% +/- 2.4% performance benefit for all subjects over the six distances covered at maximal speed wearing FB and L when compared with N. When wearing L, the gain was significantly lower (1.8% +/- 2.5%, P energy cost of swimming was significantly reduced when wearing FB and L by 4.5% +/- 5.4% and 5.5% +/- 3.1%, respectively (P energy cost of submaximal swimming and an increased distance per stroke, at the same stroke rates, and reduced freestyle performance time.

  19. Swimming trajectories of a three-sphere microswimmer near a wall

    Science.gov (United States)

    Daddi-Moussa-Ider, Abdallah; Lisicki, Maciej; Hoell, Christian; Löwen, Hartmut

    2018-04-01

    The hydrodynamic flow field generated by self-propelled active particles and swimming microorganisms is strongly altered by the presence of nearby boundaries in a viscous flow. Using a simple model three-linked sphere swimmer, we show that the swimming trajectories near a no-slip wall reveal various scenarios of motion depending on the initial orientation and the distance separating the swimmer from the wall. We find that the swimmer can either be trapped by the wall, completely escape, or perform an oscillatory gliding motion at a constant mean height above the wall. Using a far-field approximation, we find that, at leading order, the wall-induced correction has a source-dipolar or quadrupolar flow structure where the translational and angular velocities of the swimmer decay as inverse third and fourth powers with distance from the wall, respectively. The resulting equations of motion for the trajectories and the relevant order parameters fully characterize the transition between the states and allow for an accurate description of the swimming behavior near a wall. We demonstrate that the transition between the trapping and oscillatory gliding states is first order discontinuous, whereas the transition between the trapping and escaping states is continuous, characterized by non-trivial scaling exponents of the order parameters. In order to model the circular motion of flagellated bacteria near solid interfaces, we further assume that the spheres can undergo rotational motion around the swimming axis. We show that the general three-dimensional motion can be mapped onto a quasi-two-dimensional representational model by an appropriate redefinition of the order parameters governing the transition between the swimming states.

  20. Sex differences associated with intermittent swim stress.

    Science.gov (United States)

    Warner, Timothy A; Libman, Matthew K; Wooten, Katherine L; Drugan, Robert C

    2013-11-01

    Various animal models of depression have been used to seek a greater understanding of stress-related disorders. However, there is still a great need for novel research in this area, as many individuals suffering from depression are resistant to current treatment methods. Women have a higher rate of depression, highlighting the need to investigate mechanisms of sex differences. Therefore, we employed a new animal model to assess symptoms of depression, known as intermittent swim stress (ISS). In this model, the animal experiences 100 trials of cold water swim stress. ISS has already been shown to cause signs of behavioral depression in males, but has yet to be assessed in females. Following ISS exposure, we looked at sex differences in the Morris water maze and forced swim test. The results indicated a spatial learning effect only in the hidden platform task between male and female controls, and stressed and control males. A consistent spatial memory effect was only seen for males exposed to ISS. In the forced swim test, both sexes exposed to ISS exhibited greater immobility, and the same males and females also showed attenuated climbing and swimming, respectively. The sex differences could be due to different neural substrates for males and females. The goal of this study was to provide the first behavioral examination of sex differences following ISS exposure, so the stage of estrous cycle was not assessed for the females. This is a necessary future direction for subsequent experiments. The current article highlights the importance of sex differences in response to stress.

  1. 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 ).

  2. Research on Relative Age in Hungarian Swimming

    Directory of Open Access Journals (Sweden)

    Nagy Nikoletta

    2015-12-01

    Full Text Available In 2017, the 19th World Swimming Championship will be organized in Hungary. Up to now, many people have already been working with swimmers to achieve good results. However, in the next period they must work even harder to ensure that the national swimmers of a country as small as Hungary can achieve the outstanding results of their predecessors. Since high-level competitions in swimming have become more intense, innovations including scientific studies are needed during preparation for the event. The purpose of this paper is to present the major results of an independent study carried out by the authors about the relative age of the best Hungarian swimmers with the aim of contributing to their preparation. The research population consisted of selected age groups of swimmers registered by the Hungarian Swimming Association (N=400. The method for data collection was an analysis of documents. To evaluate the data, the Chi-square and Kruskal-Wallis tests were used. The results are presented according to the period of the competitor’s date of birth, gender, and age group. The results confirm only partly the hypothesis that people born in the first quarters of the year play a dominant role in Hungarian national swimming teams. In the conclusion, the authors recommend further research on relative age in swimming and in other sports.

  3. 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

  4. Settling distances of benthic invertebrates in a sediment mobilization simulation in semi-natural flumes

    Directory of Open Access Journals (Sweden)

    Maria Cristina Bruno

    2015-10-01

    Full Text Available Drift time and distance depend on the ability of the drifting invertebrates to alter their body posture or by swimming, and these behaviors may change according to the local hydraulic environment, resulting in different distances travelled before exiting the drift. Such drift and settlement mediated invertebrate movement determine dispersal processes and ultimately generates distribution patterns within streams. We conducted an experiment in an open-air, artificial flume system directly fed by an Alpine stream, where we disturbed the sediment in the flumes, inducing catastrophic drift in the benthic community, and then assessed the settlement distances of benthic invertebrates. For each flume, we collected drift samples by disturbing the substrate at 1.5 m intervals, at increasing distance from the downstream end, for a total of 7 disturbances and a maximum settling distance of 10 m in each flume, with five replicates (i.e., five flumes for each disturbance. The disturbances induced a massive catastrophic drift in Ephemeroptera, Plecoptera and Trichoptera, always higher than the behaviorally-occurring basedrift. The Settling Index calculated over the total drift collected at each distance increased with increasing distance, and after 10 m, 90% of the drifting animals had settled. Evenness and taxa richness progressively decrease with increasing settling distance. All drifting taxa were represented mainly by young instars. We used the drift collected at 1 m from the disturbance to standardize the remaining samples, based on the assumption that 1 m is not a distance long enough to allow animals to settle at that water velocity. We calculated the percentage of possible drifters which settled by computing a Settling Index for each taxon. The drifting taxa listed by decreasing Settling Index scores were Epeorus sp., Rhithrogena semicolorata, Isoperla spp., Sericostoma spp., Ecdyonurus spp., Nemoura spp., Leuctra spp., Baetis spp., Hydropsyche spp

  5. 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.

  6. 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.

  7. Is swimming during pregnancy a safe exercise?

    DEFF Research Database (Denmark)

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

    2010-01-01

    ,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......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......, bicyclists were included as an additional comparison group. RESULTS: Risk estimates were similar for swimmers and bicyclists, including those who swam throughout pregnancy and those who swam more than 1.5 hours per week. Compared with nonexercisers, women who swam in early/mid-pregnancy had a slightly...

  8. The distal short consensus repeats 1 and 2 of the membrane cofactor protein CD46 and their distance from the cell membrane determine productive entry of species B adenovirus serotype 35.

    Science.gov (United States)

    Fleischli, Christoph; Verhaagh, Sandra; Havenga, Menzo; Sirena, Dominique; Schaffner, Walter; Cattaneo, Roberto; Greber, Urs F; Hemmi, Silvio

    2005-08-01

    The human regulator of complement activation membrane cofactor protein (CD46) has recently been identified as an attachment receptor for most species B adenoviruses (Ads), including Ad type 3 (Ad3), Ad11, and Ad35, as well as species D Ad37. To characterize the interaction between Ad35 and CD46, hybrid receptors composed of different CD46 short consensus repeat (SCR) domains fused to immunoglobulin-like domains of CD4 and a set of 36 CD46 mutants containing semiconservative changes of single amino acids within SCR domains I and II were tested in binding and in Ad35-mediated luciferase transduction assays. In addition, anti-CD46 antibodies and soluble polypeptides constituting various CD46 domains were used in binding inhibition studies. Our data indicate that (i) CD46 SCR I or SCR II alone confers low but significant Ad35 binding; (ii) the presence of SCR I and II is required for optimal binding and transgene expression; (iii) transduction efficiencies equivalent to that of full-length CD46 are obtained if SCR I and II are at an appropriate distance from the cell membrane; (iv) ablation of the N-glycan attached to SCR I has no influence on receptor function, whereas ablation of the SCR II N-glycan results in about a two- to threefold reduction of binding and transgene expression; (v) most putative Ad35 binding residues are located on the same solvent-exposed face of the SCR I or SCR II domain, which are twisted by about 90 degrees ; and (vi) the putative Ad35 binding sites partly overlap with the measles virus binding surface.

  9. 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

  10. Infections Unlikely to be Spread Through Swimming Pools

    Science.gov (United States)

    ... Water Home Infections Unlikely to be Spread Through Swimming Pools Language: English (US) Español (Spanish) Recommend on ... included below. Infections Unlikely to be Spread by Swimming Pools Head Lice Head lice are unlikely to ...

  11. 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...

  12. IMMEDIATE EFFECTS OF DEEP TRUNK MUSCLE TRAINING ON SWIMMING START PERFORMANCE.

    Science.gov (United States)

    Iizuka, Satoshi; Imai, Atsushi; Koizumi, Keisuke; Okuno, Keisuke; Kaneoka, Koji

    2016-12-01

    In recent years, deep trunk muscle training has been adopted in various sports, including swimming. This is performed both in everyday training and as part of the warm-up routine before competitive races. It is suggested that trunk stabilization exercises are effective in preventing injury, and aid in improving performance. However, conclusive evidence of the same is yet to be obtained. The time of start phase of swimming is a factor that can significantly influence competition performance in a swimming race. If trunk stabilization exercises can provide instantaneous trunk stability, it is expected that they will lead to performance improvements in the start phase of swimming. The purpose of this study was to investigate the immediate effect of trunk stabilization exercises on the start phase in swimming. Intervention study. Nine elite male swimmers (mean age 20.2 ± 1.0 years; height 174.4 ± 3.5 cm; weight 68.9 ± 4.1 kg) performed the swimming start movement. The measurement variables studied included flying distance, and the time and velocity of subjects at hands' entry and on reaching five meters. Measurements were taken in trials immediately before and after the trunk stabilization exercises. A comparison between pre- and post-exercise measurements was assessed. The time to reach five meters (T 5m ) decreased significantly after trunk stabilization exercises, by 0.019 s (p = 0.02). Velocity at entry (V entry ) did not demonstrate significant change, while velocity at five meters (V 5m ) increased significantly after the exercises (p = 0.023). In addition, the speed reduction rate calculated from V entry and V 5m significantly decreased by 5.17% after the intervention (p = 0.036). Trunk stabilization exercises may help reduce the time from start to five meters in the start phase in swimming. The results support the hypothesis that these exercises may improve swimming performance. Level 3b.

  13. 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...... a swimming pool with that collected from a flume, as a function of the swimmer's stroke rate and stroke count, with the objective of identifying the impact on the swimmer's performance. The differences were determined by the analysis of the stroke's features, comparing several strokes normalized to one...

  14. Paramecium swimming in a capillary tube

    Science.gov (United States)

    Jana, Saikat; Jung, Sunghwan

    2010-03-01

    Micro-organisms exhibit different strategies for swimming in complex environments. Many micro-swimmers such as paramecium congregate and tend to live near wall. We investigate how paramecium moves in a confined space as compared to its motion in an unbounded fluid. A new theoretical model based on Taylor's sheet is developed, to study such boundary effects. In experiments, paramecia are put inside capillary tubes and their swimming behavior is observed. The data obtained from experiments is used to test the validity of our theoretical model and understand how the cilia influence the locomotion of paramecia in confined geometries.

  15. Water baths for farmed mink: intra-individual consistency and inter-individual variation in swimming behaviour, and effects on stereotyped behaviour

    Directory of Open Access Journals (Sweden)

    J. MONONEN

    2008-12-01

    Full Text Available Swimming behaviour and effects of water baths on stereotyped behaviour in farmed mink (Mustela vison were studied in three experiments. The singly-housed mink had access from their home cages to extra cages with 20.5 litre water baths. Two short-term experiments aimed to investigate how quickly adult and juvenile mink start using and how consistently they use water baths over 10 days, and whether the extent of the use correlates between dams and their females kits. A four-month experiment was designed to compare the development of stereotyped behaviour in juvenile mink housed with and without swimming opportunity. The behavioural analyses were based on several 24-hour video recordings carried out in all three experiments. There were obvious inter-individual differences and intra-individual consistency in swimming frequency and time. Farmed mink’s motivation to swim can be assessed in short-term experiments, and measurement of water losses from the swimming baths and use of instantaneous sampling with 10 min sampling intervals provide quite reliable measures of the amount of swimming. The bath use of the juveniles correlated with that of their dams, indicating that an individual mink’s eagerness to swim may have a genetic component. The lower amount of stereotyped behaviour in mink housed with water baths indicates that long-term access to baths may alleviate frustration in singly-housed juvenile farmed mink.;

  16. (Important hygienic aspects for swimming pools (author's transl))

    Energy Technology Data Exchange (ETDEWEB)

    Somosi, G

    1981-01-01

    The major epidemics which occurred in Hungary and originated from water in swimming pools are reported. The difficulties encountered in producing epidemiological evidence and in monitoring infections originating from water in swimming pools are mentioned. The possibilities of controlling the water quality in swimming pools and of preventing infections are discussed. Reference is made to the existing bacteriological limit values in Hungary to be observed in the recirculation of water in swimming pools.

  17. Physiological demands of a swimming-based video game: Influence of gender, swimming background, and exergame experience.

    Science.gov (United States)

    Soltani, Pooya; Figueiredo, Pedro; Ribeiro, João; Fernandes, Ricardo J; Vilas-Boas, João Paulo

    2017-07-12

    Active video games (exergames) may provide short-term increase in energy expenditure. We explored the effects of gender and prior experience on aerobic and anaerobic energy systems contributions, and the activity profiles of 40 participants playing with a swimming exergame. We recorded oxygen consumption and assessed blood lactate after each swimming technique. We also filmed participants' gameplays, divided them into different phases and tagged them as active or inactive. Anaerobic pathway accounted for 8.9 ± 5.6% of total energy expenditure and although experienced players were less active compared to novice counterparts (η² increase in physiological measures might happen in the beginning of gameplay because of unfamiliarity with the game mechanics. Despite low levels of activity compared to real sport, both aerobic and anaerobic energy systems should be considered in the evaluation of exergames. Game mechanics (involving the whole body) and strategies to minimize pragmatic play might be used for effective and meaningful game experience.

  18. Gesture Interaction at a Distance

    NARCIS (Netherlands)

    Fikkert, F.W.

    2010-01-01

    The aim of this work is to explore, from a perspective of human behavior, which gestures are suited to control large display surfaces from a short distance away; why that is so; and, equally important, how such an interface can be made a reality. A well-known example of the type of interface that is

  19. 76 FR 60732 - Drawbridge Operation Regulations; Navesink (Swimming) River, NJ

    Science.gov (United States)

    2011-09-30

    ... Operation Regulations; Navesink (Swimming) River, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... (Swimming) River between Oceanic and Locust Point, New Jersey. The deviation is necessary to facilitate...: The Oceanic Bridge, across the Navesink (Swimming) River, mile 4.5, between Oceanic and Locust Point...

  20. Do all frogs swim alike? The effect of ecological specialization on swimming kinematics in frogs

    Czech Academy of Sciences Publication Activity Database

    Robovská-Havelková, P.; Aerts, P.; Roček, Zbyněk; Přikryl, Tomáš; Fabre, A.-C.; Herrel, A.

    2014-01-01

    Roč. 217, č. 20 (2014), s. 3637-3644 ISSN 0022-0949 Institutional support: RVO:67985831 Keywords : Anura * kinematics * locomotion * swimming Subject RIV: EG - Zoology Impact factor: 2.897, year: 2014

  1. Gene expression changes in blood RNA after swimming in a chlorinated pool.

    Science.gov (United States)

    Salas, Lucas A; Font-Ribera, Laia; Bustamante, Mariona; Sumoy, Lauro; Grimalt, Joan O; Bonnin, Sarah; Aguilar, Maria; Mattlin, Heidi; Hummel, Manuela; Ferrer, Anna; Kogevinas, Manolis; Villanueva, Cristina M

    2017-08-01

    Exposure to disinfection by-products (DBP) such as trihalomethanes (THM) in swimming pools has been linked to adverse health effects in humans, but their biological mechanisms are unclear. We evaluated short-term changes in blood gene expression of adult recreational swimmers after swimming in a chlorinated pool. Volunteers swam 40min in an indoor chlorinated pool. Blood samples were drawn and four THM (chloroform, bromodichloromethane, dibromochloromethane and bromoform) were measured in exhaled breath before and after swimming. Intensity of physical activity was measured as metabolic equivalents (METs). Gene expression in whole blood mRNA was evaluated using IlluminaHumanHT-12v3 Expression-BeadChip. Linear mixed models were used to evaluate the relationship between gene expression changes and THM exposure. Thirty-seven before-after pairs were analyzed. The median increase from baseline to after swimming were: 0.7 to 2.3 for MET, and 1.4 to 7.1μg/m 3 for exhaled total THM (sum of the four THM). Exhaled THM increased on average 0.94μg/m 3 per 1 MET. While 1643 probes were differentially expressed post-exposure. Of them, 189 were also associated with exhaled levels of individual/total THM or MET after False Discovery Rate. The observed associations with the exhaled THM were low to moderate (Log-fold change range: -0.17 to 0.15). In conclusion, we identified short-term gene expression changes associated with swimming in a pool that were minor in magnitude and their biological meaning was unspecific. The high collinearity between exhaled THM levels and intensity of physical activity precluded mutually adjusted models with both covariates. These exploratory results should be validated in future studies. Copyright © 2017. Published by Elsevier B.V.

  2. Biomechanics of swimming in developing larval fish

    NARCIS (Netherlands)

    Voesenek, Cees J.; Muijres, Florian T.; Leeuwen, Van Johan L.

    2018-01-01

    Most larvae of bony fish are able to swim almost immediately after hatching. Their locomotory system supports several vital functions: fish larvae make fast manoeuvres to escape from predators, aim accurately during suction feeding and maymigrate towards suitable future habitats. Owing to their

  3. 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.…

  4. 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…

  5. Swimming-pool piles; Piles piscines

    Energy Technology Data Exchange (ETDEWEB)

    Trioulaire, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In France two swimming-pool piles, Melusine and Triton, have just been set in operation. The swimming-pool pile is the ideal research tool for neutron fluxes of the order of 10{sup 13}. This type of pile can be of immediate interest to many research centres, but its cost must be reduced and a break with tradition should be observed in its design. It would be an advantage: - to bury the swimming-pool; - to reject the experimental channel; - to concentrate the cooling circuit in the swimming-pool; - to carry out all manipulations in the water; - to double the core. (author) [French] En France, deux piles piscines, Melusine et Triton, viennent d'entrer en service. La pile piscine est l'outil de recherche ideal pour des flux de neutrons de l'ordre de 10{sup 13}. Ce type de pile peut interesser des maintenant de nombreux centres de recherches mais il faut reduire son prix de revient et rompre avec le conformisme de sa conception. Il y a avantage: - a enterrer la piscine; - a supprimer les canaux experimentaux; - a concentrer le circuit de refrigeration dans la piscine; - a effectuer toutes les manipulations dans l'eau; - a doubler le coeur. (auteur)

  6. Swimming in air-breathing fishes.

    Science.gov (United States)

    Lefevre, S; Domenici, P; McKenzie, D J

    2014-03-01

    Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise. © 2014 The Fisheries Society of the British Isles.

  7. Locomotor activity during the frenzy swim: analysing early swimming behaviour in hatchling sea turtles.

    Science.gov (United States)

    Pereira, Carla M; Booth, David T; Limpus, Colin J

    2011-12-01

    Swimming effort of hatchling sea turtles varies across species. In this study we analysed how swim thrust is produced in terms of power stroke rate, mean maximum thrust per power stroke and percentage of time spent power stroking throughout the first 18 h of swimming after entering the water, in both loggerhead and flatback turtle hatchlings and compared this with previous data from green turtle hatchlings. Loggerhead and green turtle hatchlings had similar power stroke rates and percentage of time spent power stroking throughout the trial, although mean maximum thrust was always significantly higher in green hatchlings, making them the most vigorous swimmers in our three-species comparison. Flatback hatchlings, however, were different from the other two species, with overall lower values in all three swimming variables. Their swimming effort dropped significantly during the first 2 h and kept decreasing significantly until the end of the trial at 18 h. These results support the hypothesis that ecological factors mould the swimming behaviour of hatchling sea turtles, with predator pressure being important in determining the strategy used to swim offshore. Loggerhead and green turtle hatchlings seem to adopt an intensely vigorous and energetically costly frenzy swim that would quickly take them offshore into the open ocean in order to reduce their exposure to near-shore aquatic predators. Flatback hatchlings, however, are restricted in geographic distribution and remain within the continental shelf region where predator pressure is probably relatively constant. For this reason, flatback hatchlings might use only part of their energy reserves during a less vigorous frenzy phase, with lower overall energy expenditure during the first day compared with loggerhead and green turtle hatchlings.

  8. 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…

  9. Unsteady propulsion by an intermittent swimming gait

    Science.gov (United States)

    Akoz, Emre; Moored, Keith W.

    2018-01-01

    Inviscid computational results are presented on a self-propelled swimmer modeled as a virtual body combined with a two-dimensional hydrofoil pitching intermittently about its leading edge. Lighthill (1971) originally proposed that this burst-and-coast behavior can save fish energy during swimming by taking advantage of the viscous Bone-Lighthill boundary layer thinning mechanism. Here, an additional inviscid Garrick mechanism is discovered that allows swimmers to control the ratio of their added mass thrust-producing forces to their circulatory drag-inducing forces by decreasing their duty cycle, DC, of locomotion. This mechanism can save intermittent swimmers as much as 60% of the energy it takes to swim continuously at the same speed. The inviscid energy savings are shown to increase with increasing amplitude of motion, increase with decreasing Lighthill number, Li, and switch to an energetic cost above continuous swimming for sufficiently low DC. Intermittent swimmers are observed to shed four vortices per cycle that form into groups that are self-similar with the DC. In addition, previous thrust and power scaling laws of continuous self-propelled swimming are further generalized to include intermittent swimming. The key is that by averaging the thrust and power coefficients over only the bursting period then the intermittent problem can be transformed into a continuous one. Furthermore, the intermittent thrust and power scaling relations are extended to predict the mean speed and cost of transport of swimmers. By tuning a few coefficients with a handful of simulations these self-propelled relations can become predictive. In the current study, the mean speed and cost of transport are predicted to within 3% and 18% of their full-scale values by using these relations.

  10. SWIM (Soil and Water Integrated Model)

    Energy Technology Data Exchange (ETDEWEB)

    Krysanova, V; Wechsung, F; Arnold, J; Srinivasan, R; Williams, J

    2000-12-01

    The model SWIM (Soil and Water Integrated Model) was developed in order to provide a comprehensive GIS-based tool for hydrological and water quality modelling in mesoscale and large river basins (from 100 to 10,000 km{sup 2}), which can be parameterised using regionally available information. The model was developed for the use mainly in Europe and temperate zone, though its application in other regions is possible as well. SWIM is based on two previously developed tools - SWAT and MATSALU (see more explanations in section 1.1). The model integrates hydrology, vegetation, erosion, and nutrient dynamics at the watershed scale. SWIM has a three-level disaggregation scheme 'basin - sub-basins - hydrotopes' and is coupled to the Geographic Information System GRASS (GRASS, 1993). A robust approach is suggested for the nitrogen and phosphorus modelling in mesoscale watersheds. SWIM runs under the UNIX environment. Model test and validation were performed sequentially for hydrology, crop growth, nitrogen and erosion in a number of mesoscale watersheds in the German part of the Elbe drainage basin. A comprehensive scheme of spatial disaggregation into sub-basins and hydrotopes combined with reasonable restriction on a sub-basin area allows performing the assessment of water resources and water quality with SWIM in mesoscale river basins. The modest data requirements represent an important advantage of the model. Direct connection to land use and climate data provides a possibility to use the model for analysis of climate change and land use change impacts on hydrology, agricultural production, and water quality. (orig.)

  11. An Evaluation of the Usefulness of Stroke Index Values in the Swimming Training of People with Disabilities

    Directory of Open Access Journals (Sweden)

    Seidel Wojciech

    2016-09-01

    Full Text Available Introduction. When evaluating the swimming technique of people with disabilities, a particularly important factor, besides physiological aspects, is the efficiency of the effort expended. This suggests that assessing and monitoring the effectiveness of swimming should be a regular part of training for swimmers with disabilities. Therefore, it seems important to distinguish how changes occur in the parameters that determine the effectiveness of swimming. This is especially true of anaerobic lactic exercise as the lactic acid concentration in the blood increases significantly. The aim of this study was to evaluate the usefulness of calculating velocity and the stroke index in the swimming training of people with disabilities, along with the progressive fatigue of a high-intensity interval training workout. Material and methods. The sample comprised 12 elite competitors with a disability. The experiment consisted in swimming sequential distances of 48 m, 50 m, 52 m, and 54 m at maximum intensity. Competitors performed four sets of four repetitions with a 75-second interval between repetitions and 15 minutes of active resting between sets. All sets were recorded using five digital cameras with a frequency of 50 frames per second. The recorded material was analysed with the use of motion analysis software, and the stroke index was calculated. Results. There was found to be no significant change in the average swimming velocity during each set and corresponding repetition, which means that the participants were able to tolerate the training intensity. Also, the stroke index did not change to a statistically significant degree in either of the subsequent sets or the subsequent repetitions (p < 0.05. Conclusions. We conclude that analysing the value of the swimming stroke index for people with disabilities can be a diagnostic method for assessing the effectiveness of high-intensity interval training.

  12. SEARCHING FOR CRITERIA IN EVALUATING THE MONOFIN SWIMMING TURN FROM THE PERSPECTIVE OF COACHING AND IMPROVING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Marek Rejman

    2008-03-01

    Full Text Available This study aims to analysise the selected kinematic parameters of the monofin swimming turn. The high complexity of performing turns is hindered by the large surface of the monofin, which disturbs control and sense of the body in water. A lack of objective data available on monofin swimming turns has resulted in field research connected with the specification of parameters needed for the evaluation of the technique. Therefore, turns observed in elite swimmers contain underlying conclusions for objective criteria, ensuring the highest level of coaching and the improving of turns in young swimmers. Six, high level, male swimmers participated in the study. The subject of the analysis was the fastest turn, from one out of three trial turns made after swimming a distance of 25 m. Images of the turns were collected from two cameras located under water in accordance with the procedures of the previous analyses of freestyle turns. The images were digitized and analysed by the SIMI®- Movement Analysis System. The interdependency of the total turn time and the remaining recorded parameters, constituted the basis for analysis of the kinematic parameters of five turn phases. The interdependency was measured using r- Pearson's correlation coefficients. The novel character of the subject covered in this study, forced interpretation of the results on the basis of turn analyses in freestyle swimming. The results allow for the creation of a diagram outlinig area of search for an effective and efficient monofin swimming turn mechanism. The activities performed from the moment of wall contact until the commencement of stroking seem to be crucial for turn improvement. A strong belief has resulted that, the correct monofin swimming turn, is more than just a simple consequence of the fastest performance of all its components. The most important criteria in evaluating the quality of the monofin swimming turn are: striving for the optimal extension of wall contact

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

    Science.gov (United States)

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

    2013-01-21

    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 performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs. An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

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

    Directory of Open Access Journals (Sweden)

    Castro Vicente

    2013-01-01

    Full Text Available 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 performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously. Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis and gene expression analyses of the host response in selected organs. Results An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. Conclusions This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

  15. Enhancing swimming pool safety by the use of range-imaging cameras

    Science.gov (United States)

    Geerardyn, D.; Boulanger, S.; Kuijk, M.

    2015-05-01

    Drowning is the cause of death of 372.000 people, each year worldwide, according to the report of November 2014 of the World Health Organization.1 Currently, most swimming pools only use lifeguards to detect drowning people. In some modern swimming pools, camera-based detection systems are nowadays being integrated. However, these systems have to be mounted underwater, mostly as a replacement of the underwater lighting. In contrast, we are interested in range imaging cameras mounted on the ceiling of the swimming pool, allowing to distinguish swimmers at the surface from drowning people underwater, while keeping the large field-of-view and minimizing occlusions. However, we have to take into account that the water surface of a swimming pool is not a flat, but mostly rippled surface, and that the water is transparent for visible light, but less transparent for infrared or ultraviolet light. We investigated the use of different types of 3D cameras to detect objects underwater at different depths and with different amplitudes of surface perturbations. Specifically, we performed measurements with a commercial Time-of-Flight camera, a commercial structured-light depth camera and our own Time-of-Flight system. Our own system uses pulsed Time-of-Flight and emits light of 785 nm. The measured distances between the camera and the object are influenced through the perturbations on the water surface. Due to the timing of our Time-of-Flight camera, our system is theoretically able to minimize the influence of the reflections of a partially-reflecting surface. The combination of a post image-acquisition filter compensating for the perturbations and the use of a light source with shorter wavelengths to enlarge the depth range can improve the current commercial cameras. As a result, we can conclude that low-cost range imagers can increase swimming pool safety, by inserting a post-processing filter and the use of another light source.

  16. 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...

  17. Reduced swimming performance repeatedly evolves upon loss of migration in landlocked populations of Alewife

    Science.gov (United States)

    Velotta, Jonathan P.; McCormick, Stephen; Jones, Andrew W.; Schultz, Eric T.

    2018-01-01

    Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology and physiology influences whole-organism performance will yield insight into the factors that shape its own evolution. We demonstrate that nonmigratory populations of alewife (Alosa pseudoharengus) have evolved reduced swimming performance in parallel, compared with their migratory ancestor. In contrast to theoretically and empirically based predictions, poor swimming among nonmigratory populations is unrelated to the evolution of osmoregulation and occurs despite the fact that nonmigratory alewives have a more fusiform (torpedo-like) body shape than their ancestor. Our results suggest that elimination of long-distance migration from the life cycle has shaped performance more than changes in body shape and physiological regulatory capacity.

  18. Amoeboid swimming: a generic self-propulsion of cells in fluids by means of membrane deformations.

    Science.gov (United States)

    Farutin, Alexander; Rafaï, Salima; Dysthe, Dag Kristian; Duperray, Alain; Peyla, Philippe; Misbah, Chaouqi

    2013-11-27

    Microorganisms, such as bacteria, algae, or spermatozoa, are able to propel themselves forward thanks to flagella or cilia activity. By contrast, other organisms employ pronounced changes of the membrane shape to achieve propulsion, a prototypical example being the Eutreptiella gymnastica. Cells of the immune system as well as dictyostelium amoebas, traditionally believed to crawl on a substratum, can also swim in a similar way. We develop a model for these organisms: the swimmer is mimicked by a closed incompressible membrane with force density distribution (with zero total force and torque). It is shown that fast propulsion can be achieved with adequate shape adaptations. This swimming is found to consist of an entangled pusher-puller state. The autopropulsion distance over one cycle is a universal linear function of a simple geometrical dimensionless quantity A/V(2/3) (V and A are the cell volume and its membrane area). This study captures the peculiar motion of Eutreptiella gymnastica with simple force distribution.

  19. The evolution of phenotypic plasticity in fish swimming

    Science.gov (United States)

    Oufiero, Christopher E.; Whitlow, Katrina R.

    2016-01-01

    Abstract Fish have a remarkable amount of variation in their swimming performance, from within species differences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to temperature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention: temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastically respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect effects of environmental variation on swimming performance, including changes in swimming kinematics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming. PMID:29491937

  20. Assessment of three-dimensional joint kinematics of the upper limb during simulated swimming using wearable inertial-magnetic measurement units.

    Science.gov (United States)

    Fantozzi, Silvia; Giovanardi, Andrea; Magalhães, Fabrício Anício; Di Michele, Rocco; Cortesi, Matteo; Gatta, Giorgio

    2016-01-01

    The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first-third quartile) of 0.97 (0.93-0.95) and 0.99 (0.97-0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.

  1. 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

    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...... swimming and pectoral fin movement over a wide speed range, presumably to support swimming stability and control, is an inefficient swimming behaviour. Finally, transition to burst-assisted swimming was associated with an increase in aerobic metabolic rate. Our study highlights factors other than swimming...

  2. Analytic processing of distance.

    Science.gov (United States)

    Dopkins, Stephen; Galyer, Darin

    2018-01-01

    How does a human observer extract from the distance between two frontal points the component corresponding to an axis of a rectangular reference frame? To find out we had participants classify pairs of small circles, varying on the horizontal and vertical axes of a computer screen, in terms of the horizontal distance between them. A response signal controlled response time. The error rate depended on the irrelevant vertical as well as the relevant horizontal distance between the test circles with the relevant distance effect being larger than the irrelevant distance effect. The results implied that the horizontal distance between the test circles was imperfectly extracted from the overall distance between them. The results supported an account, derived from the Exemplar Based Random Walk model (Nosofsky & Palmieri, 1997), under which distance classification is based on the overall distance between the test circles, with relevant distance being extracted from overall distance to the extent that the relevant and irrelevant axes are differentially weighted so as to reduce the contribution of irrelevant distance to overall distance. The results did not support an account, derived from the General Recognition Theory (Ashby & Maddox, 1994), under which distance classification is based on the relevant distance between the test circles, with the irrelevant distance effect arising because a test circle's perceived location on the relevant axis depends on its location on the irrelevant axis, and with relevant distance being extracted from overall distance to the extent that this dependency is absent. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 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...... is a strong oxidant it oxidizes the organic matter in the pool water and forms disinfection byproducts (DBPs). More than 100 different DBPs have been identified. Some of these have been found to be genotoxic and may pose an increased cancer risk for the bathers. The aim of this thesis was to give an overview...... of the strategies which can be used to achieve microbiological safe water with low levels of DBPs to ensure healthy environment for bathers. There are different approaches to achieve healthy environment in public swimming pools which in this thesis are divided into three strategies: alternatives to chlorination...

  4. Swimming versus swinging effects in spacetime

    International Nuclear Information System (INIS)

    Gueron, Eduardo; Maia, Clovis A. S.; Matsas, George E. A.

    2006-01-01

    Wisdom has recently unveiled a new relativistic effect, called 'spacetime swimming', where quasirigid free bodies in curved spacetimes can 'speed up', 'slow down' or 'deviate' their falls by performing local cyclic shape deformations. We show here that for fast enough cycles this effect dominates over a nonrelativistic related one, named here 'space swinging', where the fall is altered through nonlocal cyclic deformations in Newtonian gravitational fields. We expect, therefore, to clarify the distinction between both effects leaving no room to controversy. Moreover, the leading contribution to the swimming effect predicted by Wisdom is enriched with a higher order term and the whole result is generalized to be applicable in cases where the tripod is in large redshift regions

  5. 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.

  6. Comparative jet wake structure and swimming performance of salps.

    Science.gov (United States)

    Sutherland, Kelly R; Madin, Laurence P

    2010-09-01

    Salps are barrel-shaped marine invertebrates that swim by jet propulsion. Morphological variations among species and life-cycle stages are accompanied by differences in swimming mode. The goal of this investigation was to compare propulsive jet wakes and swimming performance variables among morphologically distinct salp species (Pegea confoederata, Weelia (Salpa) cylindrica, Cyclosalpa sp.) and relate swimming patterns to ecological function. Using a combination of in situ dye visualization and particle image velocimetry (PIV) measurements, we describe properties of the jet wake and swimming performance variables including thrust, drag and propulsive efficiency. Locomotion by all species investigated was achieved via vortex ring propulsion. The slow-swimming P. confoederata produced the highest weight-specific thrust (T=53 N kg(-1)) and swam with the highest whole-cycle propulsive efficiency (eta(wc)=55%). The fast-swimming W. cylindrica had the most streamlined body shape but produced an intermediate weight-specific thrust (T=30 N kg(-1)) and swam with an intermediate whole-cycle propulsive efficiency (eta(wc)=52%). Weak swimming performance variables in the slow-swimming C. affinis, including the lowest weight-specific thrust (T=25 N kg(-1)) and lowest whole-cycle propulsive efficiency (eta(wc)=47%), may be compensated by low energetic requirements. Swimming performance variables are considered in the context of ecological roles and evolutionary relationships.

  7. 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.

  8. Intra-abdominal pressure during swimming.

    Science.gov (United States)

    Moriyama, S; Ogita, F; Huang, Z; Kurobe, K; Nagira, A; Tanaka, T; Takahashi, H; Hirano, Y

    2014-02-01

    The present study aimed to determine the intra-abdominal pressure during front crawl swimming at different velocities in competitive swimmers and to clarify the relationships between stroke indices and changes in intra-abdominal pressure. The subjects were 7 highly trained competitive collegiate male swimmers. Intra-abdominal pressure was measured during front crawl swimming at 1.0, 1.2 and 1.4 m · s(-1) and during the Valsalva maneuver. Intra-abdominal pressure was taken as the difference between minimum and maximum values, and the mean of 6 stable front crawl stroke cycles was used. Stroke rate and stroke length were also measured as stroke indices. There were significant differences in stroke rate among all velocities (P pressure and stroke rate or stroke length (P pressure and stroke indices when controlling for swimming velocity. These findings do not appear to support the effectiveness of trunk training performed by competitive swimmers aimed at increasing intra-abdominal pressure. © Georg Thieme Verlag KG Stuttgart · New York.

  9. The swimming of a perfect deforming helix

    Science.gov (United States)

    Koens, Lyndon; Zhang, Hang; Mourran, Ahmed; Lauga, Eric

    2017-11-01

    Many bacteria rotate helical flagellar filaments in order to swim. When at rest or rotated counter-clockwise these flagella are left handed helices but they undergo polymorphic transformations to right-handed helices when the motor is reversed. These helical deformations themselves can generate motion, with for example Rhodobacter sphaeroides using the polymorphic transformation of the flagellum to generate rotation, or Spiroplasma propagating a change of helix handedness across its body's length to generate forward motion. Recent experiments reported on an artificial helical microswimmer generating motion without a propagating change in handedness. Made of a temperature sensitive gel, these swimmers moved by changing the dimensions of the helix in a non-reciprocal way. Inspired by these results and helix's ubiquitous presence in the bacterial world, we investigate how a deforming helix moves within a viscous fluid. Maintaining a single handedness along its entire length, we discuss how a perfect deforming helix can create a non-reciprocal swimming stroke, identify its principle directions of motion, and calculate the swimming kinematics asymptotically.

  10. Desipramine restricts estral cycle oscillations in swimming.

    Science.gov (United States)

    Contreras, C M; Martínez-Mota, L; Saavedra, M

    1998-10-01

    1. Desipramine (DMI) is a tricyclic antidepressant which reduces the immobility in rats forced to swim; however, it is unknown whether estral cycle phases impinge on DMI actions on immobility in daily swimming tests during several weeks. 2. In female wistar rats, vaginal smears taken before testing defined four estral phases. Afterwards, the authors assessed the latency for the first period of immobility in five-min forced swim tests practiced on 21-day DMI (DMI group), 21-day washout saline given after a 21-day DMI treatment (washout-saline group), or non-treated rats (control group). 3. We observed a longer latency for the first period of immobility in proestrus-estrus from the control and washout-saline groups. The 21-day treatment with DMI (2.1 mg/kg i.p., once a day) significantly (p estral cycle phase. 4. It is concluded that proestrus-estrus relates to increased struggling behavior. DMI enhances struggling behavior independently of hormonal state.

  11. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2016-01-01

    This 4th edition of the leading reference volume on distance metrics is characterized by updated and rewritten sections on some items suggested by experts and readers, as well a general streamlining of content and the addition of essential new topics. Though the structure remains unchanged, the new edition also explores recent advances in the use of distances and metrics for e.g. generalized distances, probability theory, graph theory, coding theory, data analysis. New topics in the purely mathematical sections include e.g. the Vitanyi multiset-metric, algebraic point-conic distance, triangular ratio metric, Rossi-Hamming metric, Taneja distance, spectral semimetric between graphs, channel metrization, and Maryland bridge distance. The multidisciplinary sections have also been supplemented with new topics, including: dynamic time wrapping distance, memory distance, allometry, atmospheric depth, elliptic orbit distance, VLBI distance measurements, the astronomical system of units, and walkability distance. Lea...

  12. 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

  13. 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…

  14. Heat stroke risk for open-water swimmers during long-distance events.

    Science.gov (United States)

    Macaluso, Filippo; Barone, Rosario; Isaacs, Ashwin W; Farina, Felicia; Morici, Giuseppe; Di Felice, Valentina

    2013-12-01

    Open-water swimming is a rapidly growing sport discipline worldwide, and clinical problems associated with long-distance swimming are now better recognized and managed more effectively. The most prevalent medical risk associated with an open-water swimming event is hypothermia; therefore, the Federation Internationale De Natation (FINA) has instituted 2 rules to reduce this occurrence related to the minimum water temperature and the time taken to complete the race. Another medical risk that is relevant to open-water swimmers is heat stroke, a condition that can easily go unnoticed. The purpose of this review is to shed light on this physiological phenomenon by examining the physiological response of swimmers during long-distance events, to define a maximum water temperature limit for competitions. We conclude that competing in water temperatures exceeding 33°C should be avoided. Copyright © 2013 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  15. 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...

  16. 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.

  17. Muscle activation behavior in a swimming exergame: Differences by experience and gaming velocity.

    Science.gov (United States)

    Soltani, Pooya; Figueiredo, Pedro; Fernandes, Ricardo J; Vilas-Boas, João Paulo

    2017-11-01

    The effects of playing intensity and prior exergame and sport experience on the activation patterns of upper limb muscles during a swimming exergame were investigated. Surface electromyography of Biceps Brachii, Triceps Brachii, Latissimus Dorsi, Upper Trapezius, and Erector Spinae of twenty participants was recorded, and the game play was divided into normal and fast. Mean muscle activation, normalized to maximum voluntary isometric contraction (MVIC), ranged from 4.9 to 95.2%MVIC and differed between normal and fast swimming for all techniques (pswimming. These behaviors are likely to happen when players understand the game mechanics, even after a short exposure. Such evaluation might help in adjusting the physical demands of sport exergames, for safe and meaningful experiences. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. 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.

  19. TECHNIQUE AND METHODOLOGY OF TRAINING IN SWIMMING CRAWL

    Directory of Open Access Journals (Sweden)

    Selim Alili

    2013-07-01

    Full Text Available The paper shows the technique and methodology training crawl swimming. Developed: the position of the head and body, footwork, hand movements, exercises for training footwork training drills and exercises for improving coordination technique on dry land and in water. Stated that accomplishes this swimmer swimming technique allows fast and is the fastest discipline. Therefore we can say that it is a favorite way of swimming and a pleasure to watch on the big stage.

  20. Swimming of Microorganisms Viewed from String and Membrane Theories

    OpenAIRE

    Kawamura, Masako; Sugamoto, Akio; Nojiri, Shin'ichi

    1993-01-01

    Swimming of microorganisms is studied from a viewpoint of extended objects (strings and membranes) swimming in the incompressible f luid of low Reynolds number. The flagellated motion is analyzed in two dimensional fluid, by using the method developed in the ciliated motion with the Joukowski transformation. Discussion is given on the conserved charges and the algebra which are associated with the area (volume)- preserving diffeomorphisms giving the swimming motion of microorganisms. It is al...

  1. Training for Distance Teaching through Distance Learning.

    Science.gov (United States)

    Cadorath, Jill; Harris, Simon; Encinas, Fatima

    2002-01-01

    Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

  2. The Distance Standard Deviation

    OpenAIRE

    Edelmann, Dominic; Richards, Donald; Vogel, Daniel

    2017-01-01

    The distance standard deviation, which arises in distance correlation analysis of multivariate data, is studied as a measure of spread. New representations for the distance standard deviation are obtained in terms of Gini's mean difference and in terms of the moments of spacings of order statistics. Inequalities for the distance variance are derived, proving that the distance standard deviation is bounded above by the classical standard deviation and by Gini's mean difference. Further, it is ...

  3. Swimming and cycling overloaded training in triathlon has no effect on running kinematics and economy.

    Science.gov (United States)

    Palazzetti, S; Margaritis, I; Guezennec, C Y

    2005-04-01

    The aim of the study was to verify whether an overloaded training (OT) in triathlon deteriorates running kinematics (RK) and running economy (RE). Thirteen well-trained male long-distance triathletes (age: 28.1 +/- 4.3 yrs; V.O (2max): 65.0 +/- 3.1 ml O (2) . min (-1) . kg (-1)) were divided into two groups: completed an individualized OT program (OG; n = 7) or maintained a normal level of training (NT) (CG; n = 6) for a duration of 3 weeks. Every week, each triathlete completed a standardized questionnaire to quantify the influence of training loads on mood state. To reach OT, total training load (h . 3 wk (-1)) was increased by 24 %; swimming and cycling total volumes were increased by 46 and 57 %, respectively, but the distance run was not modified in order to limit the risk of injuries. RK and RE were determined on treadmill test at 12 km . h (-1) before and after the 3 weeks. The 3-week swimming and cycling OT in triathlon was sufficiently stressful to alter mood state but not to deteriorate the running kinematics and economy parameters in our previously well-trained male long-distance triathletes.

  4. Roll and Yaw of Paramecium swimming in a viscous fluid

    Science.gov (United States)

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

    2012-11-01

    Many free-swimming microorganisms like ciliates, flagellates, and invertebrates exhibit helical trajectories. In particular, the Paramecium spirally swims along its anterior direction by the beating of cilia. Due to the oblique beating stroke of cilia, the Paramecium rotates along its long axis as it swims forward. Simultaneously, this long axis turns toward the oral groove side. Combined roll and yaw motions of Paramecium result in swimming along a spiral course. Using Particle Image Velocimetry, we measure and quantify the flow field and fluid stress around Paramecium. We will discuss how the non-uniform stress distribution around the body induces this yaw motion.

  5. 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

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Violet Mwaffo

    2017-11-01

    Full Text Available 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.

  8. Scaling the Thrust Production and Energetics of Inviscid Intermittent Swimming

    Science.gov (United States)

    Akoz, Emre; Moored, Keith

    2015-11-01

    Many fish have adopted an intermittent swimming gait sometimes referred as a burst-and-coast behavior. By using this gait, fish have been estimated at reducing their energetic cost of swimming by about 50%. Lighthill proposed that the skin friction drag of an undulating body can be around 400% greater than a rigidly-held coasting body, which may explain the energetic savings of intermittent swimming. Recent studies have confirmed the increase in skin friction drag over an undulating body, however, the increase is on the order of 20-70%. This more modest gain in skin friction drag is not sufficient to lead to the observed energy savings. Motivated by these observations, we investigate the inviscid mechanisms behind intermittent swimming for parameters typical of biology. We see that there is an energy savings at a fixed swimming speed for intermittent swimming as compared to continuous swimming. Then we consider three questions: What is the nature of the inviscid mechanism that leads to the observed energy savings, how do the forces and energetics of intermittent swimming scale with the swimming parameters, and what are the limitations to the benefit? Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI grant number N00014-14-1-0533.

  9. Effect of the Pacing Strategies on the Open Water 10km World Swimming Championships Performances.

    Science.gov (United States)

    Rodriguez, Luis; Veiga, Santiago

    2017-10-16

    The aim of the present research was 1) to compare the pacing strategies of different level open water swimmers during the 10km race of the FINA 2015 World Swimming Championships (WCH), and 2) to relate these pacing strategies to the race performance. Final and intermediate split times as well as intermediate race positions from the 10-kilometer race participants (69 men and 51 women) were collected from the public domain and were divided into five groups (G1 to G5) depending on their finishing positions. Medalists and finalists (G1 and G2, respectively) presented an even pacing profile with similar swimming velocities to the less successful swimmers (G3 to G5) on the initial and mid stages of the race but a 1.5-3% increase in swimming velocity in the last quarter of the race. This fast end spurt was largely related to the race performance and was not observed in the G3 and G4 (even-paced profile) or in the G5 (positive pacing profile) groups. Intermediate race positions and lap rankings were negatively related to finishing position indicating a delayed positioning of the most successful swimmers at 25%, 50% and 75% of race distance. The adoption of a conservative starting strategy by open water swimmers with a negative pacing profile and delayed partial positioning seems to increase the chances of overall race success as it allows a fast end spurt that is highly related to successful finishing race positions.

  10. 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.

  11. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2014-01-01

    This updated and revised third edition of the leading reference volume on distance metrics includes new items from very active research areas in the use of distances and metrics such as geometry, graph theory, probability theory and analysis. Among the new topics included are, for example, polyhedral metric space, nearness matrix problems, distances between belief assignments, distance-related animal settings, diamond-cutting distances, natural units of length, Heidegger’s de-severance distance, and brain distances. The publication of this volume coincides with intensifying research efforts into metric spaces and especially distance design for applications. Accurate metrics have become a crucial goal in computational biology, image analysis, speech recognition and information retrieval. Leaving aside the practical questions that arise during the selection of a ‘good’ distance function, this work focuses on providing the research community with an invaluable comprehensive listing of the main available di...

  12. 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.

  13. Unveiling the neurotoxicity of methylmercury in fish (Diplodus sargus) through a regional morphometric analysis of brain and swimming behavior assessment.

    Science.gov (United States)

    Puga, Sónia; Pereira, Patrícia; Pinto-Ribeiro, Filipa; O'Driscoll, Nelson J; Mann, Erin; Barata, Marisa; Pousão-Ferreira, Pedro; Canário, João; Almeida, Armando; Pacheco, Mário

    2016-11-01

    The current study aims to shed light on the neurotoxicity of MeHg in fish (white seabream - Diplodus sargus) by the combined assessment of: (i) MeHg toxicokinetics in the brain, (ii) brain morphometry (volume and number of neurons plus glial cells in specific brain regions) and (iii) fish swimming behavior (endpoints associated with the motor performance and the fear/anxiety-like status). Fish were surveyed for all the components after 7 (E7) and 14 (E14) days of dietary exposure to MeHg (8.7μgg -1 ), as well as after a post-exposure period of 28days (PE28). MeHg was accumulated in the brain of D. sargus after a short time (E7) and reached a maximum at the end of the exposure period (E14), suggesting an efficient transport of this toxicant into fish brain. Divalent inorganic Hg was also detected in fish brain along the experiment (indicating demethylation reactions), although levels were 100-200 times lower than MeHg, which pinpoints the organic counterpart as the great liable for the recorded effects. In this regard, a decreased number of cells in medial pallium and optic tectum, as well as an increased hypothalamic volume, occurred at E7. Such morphometric alterations were followed by an impairment of fish motor condition as evidenced by a decrease in the total swimming time, while the fear/anxiety-like status was not altered. Moreover, at E14 fish swam a greater distance, although no morphometric alterations were found in any of the brain areas, probably due to compensatory mechanisms. Additionally, although MeHg decreased almost two-fold in the brain during post-exposure, the levels were still high and led to a loss of cells in the optic tectum at PE28. This is an interesting result that highlights the optic tectum as particularly vulnerable to MeHg exposure in fish. Despite the morphometric alterations reported in the optic tectum at PE28, no significant changes were found in fish behavior. Globally, the effects of MeHg followed a multiphasic profile, where

  14. Determining the influence of muscle operating length on muscle performance during frog swimming using a bio-robotic model

    International Nuclear Information System (INIS)

    Clemente, Christofer J; Richards, Christopher

    2012-01-01

    Frogs are capable of impressive feats of jumping and swimming. Recent work has shown that anuran hind limb muscles can operate at lengths longer than the ‘optimal length’. To address the implications of muscle operating length on muscle power output and swimming mechanics, we built a robotic frog hind limb model based upon Xenopus laevis. The model simulated the force–length and force–velocity properties of vertebrate muscle, within the skeletal environment. We tested three muscle starting lengths, representing long, optimal and short starting lengths. Increasing starting length increased maximum muscle power output by 27% from 98.1 W kg −1 when muscle begins shortening from the optimal length, to 125.1 W kg −1 when the muscle begins at longer initial lengths. Therefore, longer starting lengths generated greater hydrodynamic force for extended durations, enabling faster swimming speeds of the robotic frog. These swimming speeds increased from 0.15 m s −1 at short initial muscle lengths, to 0.39 m s −1 for the longest initial lengths. Longer starting lengths were able to increase power as the muscle's force–length curve was better synchronized with the muscle's activation profile. We further dissected the underlying components of muscle force, separating force–length versus force–velocity effects, showing a transition from force–length limitations to force–velocity limitations as starting length increased. (paper)

  15. 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

  16. Hydrodynamic interaction between two trapped swimming model micro-organisms.

    Science.gov (United States)

    Matas Navarro, R; Pagonabarraga, I

    2010-09-01

    We present a theoretical study of the behaviour of two active particles under the action of harmonic traps kept at a fixed distance away from each other. We classify the steady configurations the squirmers develop as a function of their self-propelling velocity and the active stresses the swimmers induce around them. We have further analyzed the stability of such configurations, and have found that the ratio between their self-propelling velocity and the apolar flow generated through active stresses determines whether collinear parallel squirmers or perpendicularly swimming particles moving away from each other are stable. Therefore, there is a close connection between the stable configurations and the active mechanisms leading to the particle self-propulsion. The trap potential does not affect the stability of the configurations; it only modifies some of their relevant time scales. We have also observed the development of characteristic frequencies which should be observable. Finally, we show that the development of the hydrodynamic flows induced by the active particles may be relevant even when its time scale orders of magnitude smaller than the other present characteristic time scales and may destabilize the stable configurations.

  17. Environmental and personal determinants of the uptake of disinfection by-products during swimming.

    Science.gov (United States)

    Font-Ribera, Laia; Kogevinas, Manolis; Schmalz, Christina; Zwiener, Christian; Marco, Esther; Grimalt, Joan O; Liu, Jiaqi; Zhang, Xiangru; Mitch, William; Critelli, Rossana; Naccarati, Alessio; Heederik, Dick; Spithoven, Jack; Arjona, Lourdes; de Bont, Jeroen; Gracia-Lavedan, Esther; Villanueva, Cristina M

    2016-08-01

    Trihalomethanes (THMs) in exhaled breath and trichloroacetic acid (TCAA) in urine are internal dose biomarkers of exposure to disinfection by-products (DBPs) in swimming pools. We assessed how these biomarkers reflect the levels of a battery of DBPs in pool water and trichloramine in air, and evaluated personal determinants. A total of 116 adults swam during 40min in a chlorinated indoor pool. We measured chloroform, bromodichloromethane, dibromochloromethane and bromoform in exhaled breath and TCAA in urine before and after swimming, trichloramine in air and several DBPs in water. Personal determinants included sex, age, body mass index (BMI), distance swum, energy expenditure, heart rate and 12 polymorphisms in GSTT1, GSTZ1 and CYP2E1 genes. Median level of exhaled total THMs and creatinine adjusted urine TCAA increased from 0.5 to 14.4µg/m(3) and from 2.5 to 5.8µmol/mol after swimming, respectively. The increase in exhaled brominated THMs was correlated with brominated THMs, haloacetic acids, haloacetonitriles, haloketones, chloramines, total organic carbon and total organic halogen in water and trichloramine in air. Such correlations were not detected for exhaled chloroform, total THMs or urine TCAA. Exhaled THM increased more in men, urine TCAA increased more in women, and both were affected by exercise intensity. Genetic variants were associated with differential increases in exposure biomarkers. Our findings suggest that, although affected by sex, physical activity and polymorphisms in key metabolizing enzymes, brominated THMs in exhaled breath could be used as a non-invasive DBP exposure biomarker in swimming pools with bromide-containing source waters. This warrants confirmation with new studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Swimming pool reactor reliability and safety analysis

    International Nuclear Information System (INIS)

    Li Zhaohuan

    1997-01-01

    A reliability and safety analysis of Swimming Pool Reactor in China Institute of Atomic Energy is done by use of event/fault tree technique. The paper briefly describes the analysis model, analysis code and main results. Meanwhile it also describes the impact of unassigned operation status on safety, the estimation of effectiveness of defense tactics in maintenance against common cause failure, the effectiveness of recovering actions on the system reliability, the comparison of occurrence frequencies of the core damage by use of generic and specific data

  19. Brownian distance covariance

    OpenAIRE

    Székely, Gábor J.; Rizzo, Maria L.

    2010-01-01

    Distance correlation is a new class of multivariate dependence coefficients applicable to random vectors of arbitrary and not necessarily equal dimension. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but generalize and extend these classical bivariate measures of dependence. Distance correlation characterizes independence: it is zero if and only if the random vectors are independent. The notion of covariance with...

  20. Swimming direction reversal of flagella through ciliary motion of mastigonemes

    NARCIS (Netherlands)

    Namdeo, S.; Khaderi, S. N.; den Toonder, J.M.J.; Onck, P. R.; Colin, S.; Morini, G.L.

    Bio-inspired designs can provide an answer to engineering problems such as swimming strategies at the micron or nano-scale. Scientists are now designing artificial micro-swimmers that can mimic flagella-powered swimming of micro-organisms. In an application such as lab-on-a-chip in which

  1. Solar collectors for swimming pools still going strong

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    According to the opinion of the experts, solar energy heating may be technically 'mature' but the profitability is by no means that far. However, solar systems are a good alternative for heating the water in swimming pools. Four solar collector systems developed by different firms to heat swimming pools, including prices, are presented.

  2. Swimming performance of a biomimetic compliant fish-like robot

    Science.gov (United States)

    Epps, Brenden P.; Valdivia Y Alvarado, Pablo; Youcef-Toumi, Kamal; Techet, Alexandra H.

    2009-12-01

    Digital particle image velocimetry and fluorescent dye visualization are used to characterize the performance of fish-like swimming robots. During nominal swimming, these robots produce a ‘V’-shaped double wake, with two reverse-Kármán streets in the far wake. The Reynolds number based on swimming speed and body length is approximately 7500, and the Strouhal number based on flapping frequency, flapping amplitude, and swimming speed is 0.86. It is found that swimming speed scales with the strength and geometry of a composite wake, which is constructed by freezing each vortex at the location of its centroid at the time of shedding. Specifically, we find that swimming speed scales linearly with vortex circulation. Also, swimming speed scales linearly with flapping frequency and the width of the composite wake. The thrust produced by the swimming robot is estimated using a simple vortex dynamics model, and we find satisfactory agreement between this estimate and measurements made during static load tests.

  3. 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

  4. 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

  5. 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...

  6. Geometric Aspects of Force Controllability for a Swimming Model

    International Nuclear Information System (INIS)

    Khapalov, A. Y.

    2008-01-01

    We study controllability properties (swimming capabilities) of a mathematical model of an abstract object which 'swims' in the 2-D Stokes fluid. Our goal is to investigate how the geometric shape of this object affects the forces acting upon it. Such problems are of interest in biology and engineering applications dealing with propulsion systems in fluids

  7. 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 ...

  8. Biomechanical aspects of peak performance in human swimming

    NARCIS (Netherlands)

    Toussaint, H.M.; Truijens, M.J.

    2005-01-01

    Peak performances in sport require the full deployment of all the powers an athlete possesses. How factors such as mechanical power output, technique and drag, each individually, but also in concert, determine swimming performance is the subject of this enquiry. This overview of swimming

  9. Body dynamics and hydrodynamics of swimming larvae: a computational study

    NARCIS (Netherlands)

    Li, G.; Müller, U.K.; Leeuwen, van J.L.; Liu, H.

    2012-01-01

    To understand the mechanics of fish swimming, we need to know the forces exerted by the fluid and how these forces affect the motion of the fish. To this end, we developed a 3-D computational approach that integrates hydrodynamics and body dynamics. This study quantifies the flow around a swimming

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Distance-regular graphs

    NARCIS (Netherlands)

    van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

    2016-01-01

    This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

  15. 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

  16. EFFECTS OF THREE FEEDBACK CONDITIONS ON AEROBIC SWIM SPEEDS

    Directory of Open Access Journals (Sweden)

    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

  17. Haptic Discrimination of Distance

    Science.gov (United States)

    van Beek, Femke E.; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

    2014-01-01

    While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive) and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices. PMID:25116638

  18. Haptic discrimination of distance.

    Directory of Open Access Journals (Sweden)

    Femke E van Beek

    Full Text Available While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices.

  19. Interface Simulation Distances

    Directory of Open Access Journals (Sweden)

    Pavol Černý

    2012-10-01

    Full Text Available The classical (boolean notion of refinement for behavioral interfaces of system components is the alternating refinement preorder. In this paper, we define a distance for interfaces, called interface simulation distance. It makes the alternating refinement preorder quantitative by, intuitively, tolerating errors (while counting them in the alternating simulation game. We show that the interface simulation distance satisfies the triangle inequality, that the distance between two interfaces does not increase under parallel composition with a third interface, and that the distance between two interfaces can be bounded from above and below by distances between abstractions of the two interfaces. We illustrate the framework, and the properties of the distances under composition of interfaces, with two case studies.

  20. Tourists consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    The environmental impact of tourism mobility is linked to the distances travelled in order to reach a holiday destination, and with tourists travelling more and further than previously, an understanding of how the tourists view the distance they travel across becomes relevant. Based on interviews...... contribute to an understanding of how it is possible to change tourism travel behaviour towards becoming more sustainable. How tourists 'consume distance' is discussed, from the practical level of actually driving the car or sitting in the air plane, to the symbolic consumption of distance that occurs when...... travelling on holiday becomes part of a lifestyle and a social positioning game. Further, different types of tourist distance consumers are identified, ranging from the reluctant to the deliberate and nonchalant distance consumers, who display very differing attitudes towards the distance they all travel...

  1. Swimming Improves Pain and Functional Capacity of Patients With Fibromyalgia: A Randomized Controlled Trial.

    Science.gov (United States)

    Fernandes, Giovana; Jennings, Fabio; Nery Cabral, Michele Vieira; Pirozzi Buosi, Ana Letícia; Natour, Jamil

    2016-08-01

    To evaluate the effect of swimming on pain, functional capacity, aerobic capacity, and quality of life in patients with fibromyalgia (FM). Randomized controlled trial. Rheumatology outpatient clinics of a university hospital. Women with FM (N=75; age range, 18-60y) randomly assigned to a swimming group (SG) (n=39) or a walking group (WG) (n=36). The SG performed 50 minutes of swimming 3 times a week for 12 weeks, with a heart rate at 11 beats under the anaerobic threshold. The WG performed walking with a heart rate at the anaerobic threshold, with the same duration and frequency as the SG. Participants were evaluated before the exercise protocols (t0), at 6 weeks (t6), and at 12 weeks (t12) after the onset of the protocols. The primary outcome measure was the visual analog scale for pain. The secondary measurements were the Fibromyalgia Impact Questionnaire and the Medical Outcomes Study 36-Item Short-Form Health Survey for quality of life; a spiroergometric test for cardiorespiratory variables; and the timed Up & Go test for functional performance. Patients in both groups experienced improvement in pain after the 12-week program, with no difference between groups (P=.658). The same results were found regarding functional capacity and quality of life. Moreover, no statistical difference between groups was found regarding aerobic capacity over time. Swimming, like walking, is an effective method for reducing pain and improving both functional capacity and quality of life in patients with FM. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. Kinematic hand parameters in front crawl at different paces of swimming.

    Science.gov (United States)

    Samson, Mathias; Monnet, Tony; Bernard, Anthony; Lacouture, Patrick; David, Laurent

    2015-11-05

    The aim of this study was to investigate the evolution of kinematic hand parameters (sweepback angle, angle of attack, velocity, acceleration and orientation of the hand relative to the absolute coordinate system) throughout an aquatic stroke and to study the possible modifications caused by a variation of the swimming pace. Seventeen competitive swimmers swam at long distance, middle distance and sprint paces. Parameters were calculated from the trajectory of seven markers on the hand measured with an optoelectronic system. Results showed that kinematic hand parameters evolve differently depending on the pace. Angle of attack, sweepback angle, acceleration and orientation of the hand do not vary significantly. The velocity of the hand increases when the pace increases, but only during the less propulsive phases (entry and stretch and downsweep to catch). The more the pace increases and the more the absolute durations of the entry and stretch and downsweep to catch phases decrease. Absolute durations of the insweep and upsweep phases remain constant. During these phases, the propulsive hand forces calculated do not vary significantly when the pace increases. The increase of swimming pace is then explained by the swimmer's capacity to maintain propulsive phases rather than increasing the force generation within each cycle. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Nutrition for power sports: middle-distance running, track cycling, rowing, canoeing/kayaking, and swimming.

    Science.gov (United States)

    Stellingwerff, Trent; Maughan, Ronald J; Burke, Louise M

    2011-01-01

    Contemporary training for power sports involves diverse routines that place a wide array of physiological demands on the athlete. This requires a multi-faceted nutritional strategy to support both general training needs--tailored to specific training phases--as well as the acute demands of competition. Elite power sport athletes have high training intensities and volumes for most of the training season, so energy intake must be sufficient to support recovery and adaptation. Low pre-exercise muscle glycogen reduces high-intensity performance, so daily carbohydrate intake must be emphasized throughout training and competition phases. There is strong evidence to suggest that the timing, type, and amount of protein intake influence post-exercise recovery and adaptation. Most power sports feature demanding competition schedules, which require aggressive nutritional recovery strategies to optimize muscle glycogen resynthesis. Various power sports have different optimum body compositions and body weight requirements, but increasing the power-to-weight ratio during the championship season can lead to significant performance benefits for most athletes. Both intra- and extracellular buffering agents may enhance performance, but more research is needed to examine the potential long-term impact of buffering agents on training adaptation. Interactions between training, desired physiological adaptations, competition, and nutrition require an individual approach and should be continuously adjusted and adapted.

  4. To Swim or Not to Swim: Potential Transmission of Balaenophilus manatorum (Copepoda: Harpacticoida) in Marine Turtles.

    Science.gov (United States)

    Domènech, Francesc; Tomás, Jesús; Crespo-Picazo, José Luis; García-Párraga, Daniel; Raga, Juan Antonio; Aznar, Francisco Javier

    2017-01-01

    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 (turtles that occur at very low densities (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.

  5. 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.

  6. The role of the entry-and-stretch phase at the different paces of race in front crawl swimming.

    Science.gov (United States)

    Samson, Mathias; Monnet, Tony; Bernard, Anthony; Lacouture, Patrick; David, Laurent

    2015-01-01

    The aim of this study was to determine the role played by the entry-and-stretch phase in the coordination of swimming, at the different paces of race. Three national level swimmers (two men and one woman) were recorded, in lateral and bottom views, in three swimming paces: sprint (50 m and 100 m), middle-distance (200 m and 400 m) and long-distance (800 m and 1500 m). Anatomical landmark positions were obtained by manual digitalisation of the videos. Computational fluid dynamics and experimental studies (with a strain gauge balance and particle image velocimetry method) were used to measure and to calculate the external forces applied to the hand and to the forearm and to visualise the flow around the profile. Entry-and-stretch is the phase which varies the most according to the swimming pace. This phase can be decomposed into two sub-phases: one, the extension forward coordinated with the insweep of the opposite arm, and another one, the rotation downward coordinated with the upsweep. Results show that, at the three paces, this phase is not propulsive and could contribute essentially to maintain the horizontal balance of the body.

  7. Differences in the effects of 5-HT1A receptor agonists on forced swimming behavior and brain 5-HT metabolism between low and high aggressive mice

    NARCIS (Netherlands)

    Veenema, AH; Cremers, TIFH; Jongsma, ME; Steenbergen, PJ; de Boer, SF; Koolhaas, JM; Jongsma, Minke E.

    Rationale: Male wild house- mice genetically selected for long attack latency ( LAL) and short attack latency ( SAL) differ in structural and functional properties of postsynaptic serotonergic- 1A ( 5- HT1A) receptors. These mouse lines also show divergent behavioral responses in the forced swimming

  8. Mechanical Study of Standard Six Beat Front Crawl Swimming by Using Swimming Human Simulation Model

    Science.gov (United States)

    Nakashima, Motomu

    There are many dynamical problems in front crawl swimming which have not been fully investigated by analytical approaches. Therefore, in this paper, standard six beat front crawl swimming is analyzed by the swimming human simulation model SWUM, which has been developed by the authors. First, the outline of the simulation model, the joint motion for one stroke cycle, and the specifications of calculation are described respectively. Next, contribution of each fluid force component and of each body part to the thrust, effect of the flutter kick, estimation of the active drag, roll motion, and the propulsive efficiency are discussed respectively. The following results were theoretically obtained: The thrust is produced at the upper limb by the normal drag force component. The flutter kick plays a role in raising the lower half of the body. The active drag coefficient in the simulation becomes 0.082. Buoyancy determines the primal wave of the roll motion fluctuation. The propulsive efficiency in the simulation becomes 0.2.

  9. 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.

  10. Transitions between three swimming gaits in Paramecium escape.

    Science.gov (United States)

    Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuis-Williams, Pascale; Baroud, Charles N

    2011-05-03

    Paramecium and other protists are able to swim at velocities reaching several times their body size per second by beating their cilia in an organized fashion. The cilia beat in an asymmetric stroke, which breaks the time reversal symmetry of small scale flows. Here we show that Paramecium uses three different swimming gaits to escape from an aggression, applied in the form of a focused laser heating. For a weak aggression, normal swimming is sufficient and produces a steady swimming velocity. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which begin by producing oscillating swimming velocities and later give way to the usual gait. Finally, escape from a life-threatening aggression is achieved by a "jumping" gait, which does not rely on the cilia but is achieved through the explosive release of a group of trichocysts in the direction of the hot spot. Measurements through high-speed video explain the role of trichocysts in defending against aggressions while showing unexpected transitions in the swimming of microorganisms. These measurements also demonstrate that Paramecium optimizes its escape pattern by taking advantage of its inertia.

  11. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    International Nuclear Information System (INIS)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-01-01

    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 [ 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

  12. 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.

  13. 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.

  14. 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

  15. Traversing psychological distance.

    Science.gov (United States)

    Liberman, Nira; Trope, Yaacov

    2014-07-01

    Traversing psychological distance involves going beyond direct experience, and includes planning, perspective taking, and contemplating counterfactuals. Consistent with this view, temporal, spatial, and social distances as well as hypotheticality are associated, affect each other, and are inferred from one another. Moreover, traversing all distances involves the use of abstraction, which we define as forming a belief about the substitutability for a specific purpose of subjectively distinct objects. Indeed, across many instances of both abstraction and psychological distancing, more abstract constructs are used for more distal objects. Here, we describe the implications of this relation for prediction, choice, communication, negotiation, and self-control. We ask whether traversing distance is a general mental ability and whether distance should replace expectancy in expected-utility theories. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Abundance, Fishing Season and Management Strategy for Blue Swimming Crab (Portunus pelagicus) in Pangkajene Kepulauan, South Sulawesi, Indonesia.

    Science.gov (United States)

    Wiyono, Eko Sri; Ihsan

    2018-03-01

    In order to manage blue swimming crabs in Pangkajene Kepulauan, management measures are required. Since the environment which affects the abundance of the blue swimming crab varies seasonally, it is necessary to take into account the seasonal nature with the aim of developing a management strategy. The objectives of this study are to define the abundance of and fishing season of blue swimming crabs in the Pangkajene Kepulauan waters, South Sulawesi, Indonesia. The fishing season was analysed using seasonal index analysis, while fish abundance was analysed by means of Equilibrium-Schaefer. The result of this study demonstrated that fishermen allocate their fishing gear all year, although the fish catch is seasonal. Based on analysis of the result, the fishing season for the blue swimming crabs is short. The peak fishing season starts in May and finishes in June. However, in order to enable their families to earn a living, fishermen operated their fishing gear throughout the year. As a result, both catch landing and effort were close to maximum sustainable yield (MSY). In order to reduce fishing pressure, it is necessary to reduce fishing gear and have a seasonal arrangement regarding fishing gear allocation.

  17. 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

  18. 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...

  19. 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...

  20. Numerical distance protection

    CERN Document Server

    Ziegler, Gerhard

    2011-01-01

    Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

  1. A tentative theory of large distance physics

    International Nuclear Information System (INIS)

    Friedan, Daniel

    2003-01-01

    A theoretical mechanism is devised to determine the large distance physics of spacetime. It is a two dimensional nonlinear model, the lambda model, set to govern the string world surface in an attempt to remedy the failure of string theory, as it stands. The lambda model is formulated to cancel the infrared divergent effects of handles at short distance on the world surface. The target manifold is the manifold of background spacetimes. The coupling strength is the spacetime coupling constant. The lambda model operates at 2d distance Δ -1 , very much shorter than the 2d distance μ -1 where the world surface is seen. A large characteristic spacetime distance L is given by L 2 ln(Δ/μ). Spacetime fields of wave number up to 1=L are the local coordinates for the manifold of spacetimes. The distribution of fluctuations at 2d distances shorter than Δ -1 gives the a priori measure on the target manifold, the manifold of spacetimes. If this measure concentrates at a macroscopic spacetime, then, nearby, it is a measure on the spacetime fields. The lambda model thereby constructs a spacetime quantum field theory, cutoff at ultraviolet distance L, describing physics at distances larger than L. The lambda model also constructs an effective string theory with infrared cutoff L, describing physics at distances smaller than L. The lambda model evolves outward from zero 2d distance, Δ -1 = 0, building spacetime physics starting from L ∞ and proceeding downward in L. L can be taken smaller than any distance practical for experiments, so the lambda model, if right, gives all actually observable physics. The harmonic surfaces in the manifold of spacetimes are expected to have novel nonperturbative effects at large distances. (author)

  2. Comparison of Temporal Parameters of Swimming Rescue Elements When Performed Using Dolphin and Flutter Kick with Fins - Didactical Approach

    Science.gov (United States)

    Rejman, Marek; Wiesner, Wojciech; Silakiewicz, Piotr; Klarowicz, Andrzej; Abraldes, J. Arturo

    2012-01-01

    The aim of this study was an analysis of the time required to swim to a victim and tow them back to shore, while perfoming the flutter-kick and the dolphin-kick using fins. It has been hypothesized that using fins while using the dolphin-kick when swimming leads to reduced rescue time. Sixteen lifeguards took part in the study. The main tasks performed by them, were to approach and tow (double armpit) a dummy a distance of 50m while applying either the flutter-kick, or the dolphin-kick with fins. The analysis of the temporal parameters of both techniques of kicking demonstrates that, during the approach to the victim, neither the dolphin (tmean = 32.9s) or the flutter kick (tmean = 33.0s) were significantly faster than the other. However, when used for towing a victim the flutter kick (tmean = 47.1s) was significantly faster when compared to the dolphin-kick (tmean = 52.8s). An assessment of the level of technical skills in competitive swimming, and in approaching and towing the victim, were also conducted. Towing time was significantly correlated with the parameter that linked the temporal and technical dimensions of towing and swimming (difference between flutter kick towing time and dolphin-kick towing time, 100m medley time and the four swimming strokes evaluation). No similar interdependency has been discovered in flutter kick towing time. These findings suggest that the dolphin-kick is a more difficult skill to perform when towing the victim than the flutter-kick. Since the hypothesis stated was not confirmed, postulates were formulated on how to improve dolphin-kick technique with fins, in order to reduce swimming rescue time. Key points The source of reduction of swimming rescue time was researched. Time required to approach and to tow the victim while doing the flutter kick and the dolphin-kick with fins was analyzed. The propulsion generated by dolphin-kick did not make the approach and tow faster than the flutter kick. More difficult skill to realize of

  3. 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

  4. 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

  5. Effects of dietary 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47) exposure on medaka (Oryzias latipes) swimming behavior.

    Science.gov (United States)

    Sastre, Salvador; Fernández Torija, Carlos; Carbonell, Gregoria; Rodríguez Martín, José Antonio; Beltrán, Eulalia María; González-Doncel, Miguel

    2018-02-01

    A diet fortified with 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47: 0, 10, 100, and 1000 ng/g) was dosed to 4-7-day-old post-hatch medaka fish for 40 days to evaluate the effects on the swimming activity of fish using a miniaturized swimming flume. Chlorpyrifos (CF)-exposed fish were selected as the positive control to assess the validity and sensitivity of the behavioral findings. After 20 and 40 days of exposure, the locomotor activity was analyzed for 6 min in a flume section (arena). The CF positive control for each time point were fish exposed to 50 ng CF/ml for 48 h. Swimming patterns, presented as two-dimensional heat maps of fish movement and positioning, were obtained by geostatistical analyses. The heat maps of the control groups at time point 20 revealed visually comparable swimming patterns to those of the BDE-47-treated groups. For the comparative fish positioning analysis, both the arenas were divided into 15 proportional areas. No statistical differences were found between residence times in the areas from the control groups and those from the BDE-47-treated groups. At time point 40, the heat map overall patterns of the control groups differed visually from that of the 100-ng BDE-47/g-treated group, but a comparative analysis of the residence times in the corresponding 15 areas did not reveal consistent differences. The relative distances traveled by the control and treated groups at time points 20 and 40 were also comparable. The heat maps of CF-treated fish at both time points showed contrasting swim patterns with respect to those of the controls. These differential patterns were statistically supported with differences in the residence times for different areas. The relative distances traveled by the CF-treated fish were also significantly shorter. These results confirm the validity of the experimental design and indicate that a dietary BDE-47 exposure does not affect forced swimming in medaka at growing stages. Copyright © 2017 Elsevier Ltd

  6. ORDERED WEIGHTED DISTANCE MEASURE

    Institute of Scientific and Technical Information of China (English)

    Zeshui XU; Jian CHEN

    2008-01-01

    The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.

  7. Distance-transitive graphs

    NARCIS (Netherlands)

    Cohen, A.M.; Beineke, L.W.; Wilson, R.J.; Cameron, P.J.

    2004-01-01

    In this chapter we investigate the classification of distance-transitive graphs: these are graphs whose automorphism groups are transitive on each of the sets of pairs of vertices at distance i, for i = 0, 1,.... We provide an introduction into the field. By use of the classification of finite

  8. Distance Education in Entwicklungslandern.

    Science.gov (United States)

    German Foundation for International Development, Bonn (West Germany).

    Seminar and conference reports and working papers on distance education of adults, which reflect the experiences of many countries, are presented. Contents include the draft report of the 1979 International Seminar on Distance Education held in Addis Ababa, Ethiopia, which was jointly sponsored by the United Nations Economic Commission for Africa…

  9. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2009-01-01

    Distance metrics and distances have become an essential tool in many areas of pure and applied Mathematics. This title offers both independent introductions and definitions, while at the same time making cross-referencing easy through hyperlink-like boldfaced references to original definitions.

  10. Distance Education in Turkey

    Directory of Open Access Journals (Sweden)

    Dr. Nursel Selver RUZGAR,

    2004-04-01

    Full Text Available Distance Education in Turkey Assistant Professor Dr. Nursel Selver RUZGAR Technical Education Faculty Marmara University, TURKEY ABSTRACT Many countries of the world are using distance education with various ways, by internet, by post and by TV. In this work, development of distance education in Turkey has been presented from the beginning. After discussing types and applications for different levels of distance education in Turkey, the distance education was given in the cultural aspect of the view. Then, in order to create the tendencies and thoughts of graduates of Higher Education Institutions and Distance Education Institutions about being competitors in job markets, sufficiency of education level, advantages for education system, continuing education in different Institutions, a face-to-face survey was applied to 1284 graduates, 958 from Higher Education Institutions and 326 from Distance Education Institutions. The results were evaluated and discussed. In the last part of this work, suggestions to become widespread and improve the distance education in the country were made.

  11. 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.

  12. Avoiding Swimming Sickness (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    Pools, water parks, and other recreational water venues are popular places to relax and stay cool, but they can be sources of serious illness. In this podcast, Ashley Andujar discusses ways to stay safe while going swimming this summer.

  13. Allegheny County Public Swimming Pool, Hot Tub, and Spa Inspections

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Public swimming pool, hot tub, and spa facilities are licensed and inspected once each year to assure proper water quality, sanitation, lifeguard coverage and...

  14. Protection of swimming-induced oxidative stress in some vital ...

    African Journals Online (AJOL)

    Protection of swimming-induced oxidative stress in some vital organs by the treatment of composite extract of Withania somnifera, Ocimum sanctum and Zingiber officinalis in male rat. D Misra, B Maiti, D Ghosh ...

  15. Swimming Behavior of Individual Zooplankters During Night-Time Foraging

    National Research Council Canada - National Science Library

    McGehee, Duncan

    1998-01-01

    Amatzia Genin, Jules Jaffe, Duncan McGehee developed a method for automatically tracking individual plankters swimming through the imaging volume, and applied the method to track approximately 280,000 animals...

  16. Thermal analyses of solar swimming pool heating in Pakistan

    International Nuclear Information System (INIS)

    Ahmad, I.

    2011-01-01

    Hotels and swimming clubs in Pakistan pay huge gas bills for heating Swimming pools in winter. Winter days in most parts of Pakistan remain sunny and unglazed low cost solar collectors may be used to extend the swimming season. Installing the pool in a wind-protected area, which receives unobstructed solar radiation, may further reduce the size of the solar collectors required to heat the swimming pools. The pools should be covered with plastic sheet to eliminate evaporative heat losses and to prevent dust and tree leaves falling in the pool. The results of the thermal analysis show that in some parts of the country, a solar exposed pool can maintain comfortable temperature simply by using a plastic sheet on the pool surface. On the other hand, there are cities where solar collector array equal to twice the surface area of the pool is required to keep desired temperature in winter. (author)

  17. Safe Swimming (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    Swimmers can take simple steps to help protect themselves and others from germs that can spread in the water and cause illness. In this podcast Michele Hlavsa discusses ways to stay healthy while swimming.

  18. Effects of the swimming exercise on the consolidation and persistence of auditory and contextual fear memory.

    Science.gov (United States)

    Faria, Rodolfo Souza; Gutierres, Luís Felipe Soares; Sobrinho, Fernando César Faria; Miranda, Iris do Vale; Reis, Júlia Dos; Dias, Elayne Vieira; Sartori, Cesar Renato; Moreira, Dalmo Antonio Ribeiro

    2016-08-15

    Exposure to negative environmental events triggers defensive behavior and leads to the formation of aversive associative memory. Cellular and molecular changes in the central nervous system underlie this memory formation, as well as the associated behavioral changes. In general, memory process is established in distinct phases such as acquisition, consolidation, evocation, persistence, and extinction of the acquired information. After exposure to a particular event, early changes in involved neural circuits support the memory consolidation, which corresponds to the short-term memory. Re-exposure to previously memorized events evokes the original memory, a process that is considered essential for the reactivation and consequent persistence of memory, ensuring that long-term memory is established. Different environmental stimuli may modulate the memory formation process, as well as their distinct phases. Among the different environmental stimuli able of modulating memory formation is the physical exercise which is a potent modulator of neuronal activity. There are many studies showing that physical exercise modulates learning and memory processes, mainly in the consolidation phase of the explicit memory. However, there are few reports in the literature regarding the role of physical exercise in implicit aversive associative memory, especially at the persistence phase. Thus, the present study aimed to investigate the relationship between swimming exercise and the consolidation and persistence of contextual and auditory-cued fear memory. Male Wistar rats were submitted to sessions of swimming exercise five times a week, over six weeks. After that, the rats were submitted to classical aversive conditioning training by a pairing tone/foot shock paradigm. Finally, rats were evaluated for consolidation and persistence of fear memory to both auditory and contextual cues. Our results demonstrate that classical aversive conditioning with tone/foot shock pairing induced

  19. Short-range fundamental forces

    International Nuclear Information System (INIS)

    Antoniadis, I.; Baessler, S.; Buchner, M.; Fedorov, V.V.; Hoedl, S.; Nesvizhevsky, V.V.; Pignol, G.; Protasov, K.V.; Lambrecht, A.; Reynaud, S.; Sobolev, Y.

    2010-01-01

    We consider theoretical motivations to search for extra short-range fundamental forces as well as experiments constraining their parameters. The forces could be of two types: 1) spin-independent forces; 2) spin-dependent axion-like forces. Different experimental techniques are sensitive in respective ranges of characteristic distances. The techniques include measurements of gravity at short distances, searches for extra interactions on top of the Casimir force, precision atomic and neutron experiments. We focus on neutron constraints, thus the range of characteristic distances considered here corresponds to the range accessible for neutron experiments

  20. Exercise-training intervention studies in competitive swimming.

    Science.gov (United States)

    Aspenes, Stian Thoresen; Karlsen, Trine

    2012-06-01

    Competitive swimming has a long history and is currently one of the largest Olympic sports, with 16 pool events. Several aspects separate swimming from most other sports such as (i) the prone position; (ii) simultaneous use of arms and legs for propulsion; (iii) water immersion (i.e. hydrostatic pressure on thorax and controlled respiration); (iv) propulsive forces that are applied against a fluctuant element; and (v) minimal influence of equipment on performance. Competitive swimmers are suggested to have specific anthropometrical features compared with other athletes, but are nevertheless dependent on physiological adaptations to enhance their performance. Swimmers thus engage in large volumes of training in the pool and on dry land. Strength training of various forms is widely used, and the energetic systems are addressed by aerobic and anaerobic swimming training. The aim of the current review was to report results from controlled exercise training trials within competitive swimming. From a structured literature search we found 17 controlled intervention studies that covered strength or resistance training, assisted sprint swimming, arms-only training, leg-kick training, respiratory muscle training, training the energy delivery systems and combined interventions across the aforementioned categories. Nine of the included studies were randomized controlled trials. Among the included studies we found indications that heavy strength training on dry land (one to five repetitions maximum with pull-downs for three sets with maximal effort in the concentric phase) or sprint swimming with resistance towards propulsion (maximal pushing with the arms against fixed points or pulling a perforated bowl) may be efficient for enhanced performance, and may also possibly have positive effects on stroke mechanics. The largest effect size (ES) on swimming performance was found in 50 m freestyle after a dry-land strength training regimen of maximum six repetitions across three

  1. London 2012 Paralympic swimming: passive drag and the classification system.

    Science.gov (United States)

    Oh, Yim-Taek; Burkett, Brendan; Osborough, Conor; Formosa, Danielle; Payton, Carl

    2013-09-01

    The key difference between the Olympic and Paralympic Games is the use of classification systems within Paralympic sports to provide a fair competition for athletes with a range of physical disabilities. In 2009, the International Paralympic Committee mandated the development of new, evidence-based classification systems. This study aims to assess objectively the swimming classification system by determining the relationship between passive drag and level of swimming-specific impairment, as defined by the current swimming class. Data were collected on participants at the London 2012 Paralympic Games. The passive drag force of 113 swimmers (classes 3-14) was measured using an electro-mechanical towing device and load cell. Swimmers were towed on the surface of a swimming pool at 1.5 m/s while holding their most streamlined position. Passive drag ranged from 24.9 to 82.8 N; the normalised drag (drag/mass) ranged from 0.45 to 1.86 N/kg. Significant negative associations were found between drag and the swimming class (τ = -0.41, p < 0.01) and normalised drag and the swimming class (τ = -0.60, p < 0.01). The mean difference in drag between adjacent classes was inconsistent, ranging from 0 N (6 vs 7) to 11.9 N (5 vs 6). Reciprocal Ponderal Index (a measure of slenderness) correlated moderately with normalised drag (r(P) = -0.40, p < 0.01). Although swimmers with the lowest swimming class experienced the highest passive drag and vice versa, the inconsistent difference in mean passive drag between adjacent classes indicates that the current classification system does not always differentiate clearly between swimming groups.

  2. Trends in swimming training for individual medley events

    OpenAIRE

    Brtník, Tomáš

    2013-01-01

    Title: Trends in swimming training for individual medley events Objectives: The aim of our study was to analyze performance and training for 200 and 400 m individual medley events and describe new trends in training for these swimming events Methods: Our research design was a case study. We were interested in training of three swimmers of elite performance in the 200 and 400 m individual medley events. To identify cases, we used the analysis of documents and literature, to a limited extent, t...

  3. Cryptosporidium and Giardia in Swimming Pools, Atlanta, Georgia

    Centers for Disease Control (CDC) Podcasts

    In this podcast, Dan Rutz speaks with Dr. Joan Shields, a guest researcher with the Healthy Swimming Program at CDC, about an article in June 2008 issue of Emerging Infectious Diseases reporting on the results of a test of swimming pools in the greater Atlanta, Georgia area. Dr. Shields tested 160 pools in metro Atlanta last year for Cryptosporidium and Giardia. These germs cause most recreational water associated outbreaks.

  4. 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. PMID:23675322

  5. 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.

  6. a case series in habitual distance runners

    African Journals Online (AJOL)

    muscle injury, aponeurotic tears, ligament injuries, tendinopathy and evaluation of soft tissue ... the point of preventing visualisation of sections of the vessel lumen. (Figure 6). ... 11 constant, then intermittent. Short distances ... Gielen S, Schuler G, Adams V. Cardiovascular effects of exercise training: molecular mechanisms.

  7. Wearable inertial sensors in swimming motion analysis: a systematic review.

    Science.gov (United States)

    de Magalhaes, Fabricio Anicio; Vannozzi, Giuseppe; Gatta, Giorgio; Fantozzi, Silvia

    2015-01-01

    The use of contemporary technology is widely recognised as a key tool for enhancing competitive performance in swimming. Video analysis is traditionally used by coaches to acquire reliable biomechanical data about swimming performance; however, this approach requires a huge computational effort, thus introducing a delay in providing quantitative information. Inertial and magnetic sensors, including accelerometers, gyroscopes and magnetometers, have been recently introduced to assess the biomechanics of swimming performance. Research in this field has attracted a great deal of interest in the last decade due to the gradual improvement of the performance of sensors and the decreasing cost of miniaturised wearable devices. With the aim of describing the state of the art of current developments in this area, a systematic review of the existing methods was performed using the following databases: PubMed, ISI Web of Knowledge, IEEE Xplore, Google Scholar, Scopus and Science Direct. Twenty-seven articles published in indexed journals and conference proceedings, focusing on the biomechanical analysis of swimming by means of inertial sensors were reviewed. The articles were categorised according to sensor's specification, anatomical sites where the sensors were attached, experimental design and applications for the analysis of swimming performance. Results indicate that inertial sensors are reliable tools for swimming biomechanical analyses.

  8. Swimming as physical activity and recreation for women

    Directory of Open Access Journals (Sweden)

    Yfanti Maria

    2014-01-01

    Full Text Available The present study reviews all data that establish swimming as an everyday lifestyle and recreational activity for women, since it promotes wellness, well-being and longevity. Swimming as a natural, physical activity is one of the most effective ways of exercise, since it affects and work outs the whole body. It is the most suitable sport for all age groups, because it combines beneficial results, for both body and soul and is also a low-risk-injury physical exercise. Aim of this study is to record the effect of recreational swimming in physical condition indexes and in quality of life in women. In particular to record the benefits, since studies have shown that swimming can help in prevention and treatment of chronic diseases and improves quality of life, of well-being and longevity. Results of all studies showed that swimming, as a great natural recreational activity has multiple beneficial effects on the female body that are not limited to the physical characteristics but are extended to the mental ones. Challenges for the application and development fields of this particular method of exercise, are the quality of service provided and the staffing of departments and programs in multiple carriers, private or public. Researchers and writers agree that there are great prospects for growth for women through partnerships, with programs and systematic research in the field of recreational swimming.

  9. Ovarian and uterine alterations following forced swimming: An immunohistochemical study.

    Science.gov (United States)

    Seyed Saadat, Seyedeh Nazanin; Mohammadghasemi, Fahimeh; Ebrahimi, Hannan; Rafati Sajedi, Hanieh; Chatrnour, Gelayol

    2016-10-01

    Physical exercise is known to be a stressor stimulus that leads to reproductive disruption. The aim of this study was to evaluate the effect of forced swimming on the uterus and ovaries in mice. Adult mice (N=24) were divided into the following three groups: A, control; B, swimming in water (10 o C); and C, swimming in water (23 o C). Swimmers swam for 5 min daily for 5 consecutive days/ wk during 2 wks. An enzyme linked immunosorbent assay was used to determine serum estradiol, follicle stimulating hormone (FSH) and testosterone levels. Immunohistochemistry was performed to study apoptotic cells or estrogen receptor (ER) expression in uterine epithelial cells and ovaries. ANOVA was used for statistical analysis. Swimming in both groups reduced the serum FSH and estradiol levels (pForced swimming of 2 wks duration reduces the serum levels of FSH and estradiol without having effects on apoptosis in the ovaries or uteri of mice. Over a long period of time, forced swimming may have an adverse effect on fertility.

  10. 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.

  11. 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.

  12. 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.

  13. 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).

  14. Simulation of swimming strings immersed in a viscous fluid flow

    Science.gov (United States)

    Huang, Wei-Xi; Sung, Hyung Jin

    2006-11-01

    In nature, many phenomena involve interactions between flexible bodies and their surrounding viscous fluid, such as a swimming fish or a flapping flag. The intrinsic dynamics is complicate and not well understood. A flexible string can be regarded as a one-dimensional flag model. Many similarities can be found between the flapping string and swimming fish, although different wake speed results in a drag force for the flapping string and a propulsion force for the swimming fish. In the present study, we propose a mathematical formulation for swimming strings immersed in a viscous fluid flow. Fluid motion is governed by the Navier-Stokes equations and a momentum forcing is added in order to bring the fluid to move at the same velocity with the immersed surface. A flexible inextensible string model is described by another set of equations with an additional momentum forcing which is a result of the fluid viscosity and the pressure difference across the string. The momentum forcing is calculated by a feedback loop. Simulations of several numerical examples are carried out, including a hanging string which starts moving under gravity without ambient fluid, a swinging string immersed in a quiescent viscous fluid, a string swimming within a uniform surrounding flow, and flow over two side-by-side strings. The numerical results agree well with the theoretical analysis and previous experimental observations. Further simulation of a swimming fish is under consideration.

  15. Comparison of the effects of active, passive and mixed warm ups on swimming performance.

    Science.gov (United States)

    Adams, S; Psycharakis, S G

    2014-10-01

    The aim of this paper was to compare the effects of an active (AWU), passive (PWU) and mixed warm up (MWU) on swimming performance. Eight male competitive swimmers completed each type of WU and, following a 20-minute rest, performed a maximum 100m test on their specialised stroke. The order of WUs was randomized and there was a 7-day period between subsequent testing sessions. The time taken to complete the 100m trial was the performance measure. The rating of perceived exertion (RPE) was measured immediately post WU, while heart rate (HR) was measured pre and post WU and pre and post the maximum swim. During the 20-minute rest, the swimmers' psychological state was assessed with the CSAI-2 questionnaire. Post WU HR and RPE had the lowest values following the AWU and the highest values following the PWU (Pperformance HR increased significantly relative to pre WU HR for all conditions (P≤0.01). Swimmers had relatively low levels of anxiety and modest to high levels of self confidence for all conditions. No WU appeared to be superior to the others with respect to swimming performance. The MWU produced nearly identical values to the AWU for most variables, and was therefore found to be an appropriate alternative WU type that swimmers may use before competition. The PWU also seemed to be appropriate, but the somewhat worse performance and lower cognitive anxiety and self confidence scores recorded, albeit non-significant, suggested that more swimmers and distances are tested before any firm conclusions regarding its effectiveness can be drawn.

  16. 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.

  17. 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

  18. Swimming against the tide: explaining the Higgs

    CERN Multimedia

    Emma Sanders

    2012-01-01

    "Never before in the field of science journalism have so few journalists understood what so many physicists were telling them!" tweeted the UK Channel 4’s Tom Clarke from last December’s Higgs seminar. As a consequence, most coverage focused on debates over the use of the label “god particle” and the level of excitement of the physicists (high), whilst glossing over what this excitement was actually all about.   So what is the Higgs? Something fundamental. Something to do with mass. If your interest in physics is more than simply passing, you may find that rooms full of chattering politicians or the use of different footwear when walking through snow just don’t do the job in convincing you why the Higgs is so important. And if images of fish make you feel like a fish out of water - or at least one swimming against a strong current - then perhaps you would appreciate a different approach. The need for the Higgs Whilst gauge th...

  19. Do swimming animals mix the ocean?

    Science.gov (United States)

    Dabiri, John

    2013-11-01

    Perhaps. The oceans are teeming with billions of swimming organisms, from bacteria to blue whales. Current research efforts in biological oceanography typically focus on the impact of the marine environment on the organisms within. We ask the opposite question: can organisms in the ocean, especially those that migrate vertically every day and regionally every year, change the physical structure of the water column? The answer has potentially important implications for ecological models at local scale and climate modeling at global scales. This talk will introduce the still-controversial prospect of biogenic ocean mixing, beginning with evidence from measurements in the field. More recent laboratory-scale experiments, in which we create controlled vertical migrations of plankton aggregations using laser signaling, provide initial clues toward a mechanism to achieve efficient mixing at scales larger than the individual organisms. These results are compared and contrasted with theoretical models, and they highlight promising avenues for future research in this area. Funding from the Office of Naval Research and the National Science Foundation is gratefully acknowledged.

  20. Nutrition for synchronized swimming: a review.

    Science.gov (United States)

    Lundy, Bronwen

    2011-10-01

    Synchronized swimming enjoys worldwide popularity and has been part of the formal Olympic program since 1984. Despite this, relatively little research has been conducted on participant nutrition practices and requirements, and there are significant gaps in the knowledge base despite the numerous areas in which nutrition could affect performance and safety. This review aimed to summarize current findings and identify areas requiring further research. Uniform physique in team or duet events may be more important than absolute values for muscularity or body fat, but a lean and athletic appearance remains key. Synchronized swimmers appear to have an increased risk of developing eating disorders, and there is evidence of delayed menarche, menstrual dysfunction, and lower bone density relative to population norms. Dietary practices remain relatively unknown, but micronutrient status for iron and magnesium may be compromised. More research is required across all aspects of nutrition status, anthropometry, and physiology, and both sports nutrition and sports medicine support may be required to reduce risks for participants.

  1. 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

  2. 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.

  3. A forced damped oscillation framework for undulatory swimming provides new insights into how propulsion arises in active and passive swimming.

    Directory of Open Access Journals (Sweden)

    Amneet Pal Singh Bhalla

    Full Text Available 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.

  4. Motivation in Distance Leaming

    Directory of Open Access Journals (Sweden)

    Daniela Brečko

    1996-12-01

    Full Text Available It is estimated that motivation is one of the most important psychological functions making it possible for people to leam even in conditions that do not meet their needs. In distance learning, a form of autonomous learning, motivation is of outmost importance. When adopting this method in learning an individual has to stimulate himself and take learning decisions on his or her own. These specific characteristics of distance learning should be taken into account. This all different factors maintaining the motivation of partici­pants in distance learning are to be included. Moreover, motivation in distance learning can be stimulated with specific learning materials, clear instructions and guide-lines, an efficient feed back, personal contact between tutors and parti­cipants, stimulating learning letters, telephone calls, encouraging letters and through maintaining a positive relationship between tutor and participant.

  5. Einstein at a distance

    Energy Technology Data Exchange (ETDEWEB)

    Lambourne, Robert [Department of Physics and Astronomy, Open University, Milton Keynes (United Kingdom)

    2005-11-01

    This paper examines the challenges and rewards that can arise when the teaching of Einsteinian physics has to be accomplished by means of distance education. The discussion is mainly based on experiences gathered over the past 35 years at the UK Open University, where special and general relativity, relativistic cosmology and other aspects of Einsteinian physics, have been taught at a variety of levels, and using a range of techniques, to students studying at a distance.

  6. Long distance quantum teleportation

    Science.gov (United States)

    Xia, Xiu-Xiu; Sun, Qi-Chao; Zhang, Qiang; Pan, Jian-Wei

    2018-01-01

    Quantum teleportation is a core protocol in quantum information science. Besides revealing the fascinating feature of quantum entanglement, quantum teleportation provides an ultimate way to distribute quantum state over extremely long distance, which is crucial for global quantum communication and future quantum networks. In this review, we focus on the long distance quantum teleportation experiments, especially those employing photonic qubits. From the viewpoint of real-world application, both the technical advantages and disadvantages of these experiments are discussed.

  7. Benefits and Enjoyment of a Swimming Intervention for Youth With Cerebral Palsy: An RCT Study.

    Science.gov (United States)

    Declerck, Marlies; Verheul, Martine; Daly, Daniel; Sanders, Ross

    2016-01-01

    To investigate enjoyment and specific benefits of a swimming intervention for youth with cerebral palsy (CP). Fourteen youth with CP (aged 7 to 17 years, Gross Motor Function Classification System levels I to III) were randomly assigned to control and swimming groups. Walking ability, swimming skills, fatigue, and pain were assessed at baseline, after a 10-week swimming intervention (2/week, 40-50 minutes) or control period, after a 5-week follow-up and, for the intervention group, after a 20-week follow-up period. The level of enjoyment of each swim-session was assessed. Levels of enjoyment were high. Walking and swimming skills improved significantly more in the swimming than in the control group (P = .043; P = .002, respectively), whereas fatigue and pain did not increase. After 20 weeks, gains in walking and swimming skills were retained (P = .017; P = .016, respectively). We recommend a swimming program for youth with CP to complement a physical therapy program.

  8. Development of a swim-type ROV for narrow space inspection

    International Nuclear Information System (INIS)

    Okada, Satoshi; Otani, Kenichi; Kobayashi, Ryosuke; Ohno, Kazunori

    2017-01-01

    The swim-type remotely operated vehicle (ROV) for inspection of narrow spaces in nuclear power plants has been developed. Many structures are crowded in a confined space at regular intervals in the bottom area of a reactor. So, the thickness of the ROV shape is an important design point to ensure that the ROV can move in the space. The developed ROV has a three-dimensional swimming mechanism using six thrusters, three cameras for observing the position while moving and for making inspections easily, and a localization system. The localization system combines two elements: a gyroscope to detect the progression direction; and a slit laser that detects the progression distance using the optical cutting method. The localization method is called the modified inertial navigation (MIN) method and it was evaluated in a mock-up examination. The ROV was able to move smoothly using the MIN method and its position could be detected without making a mistake in the route followed. (author)

  9. Differential behavioral effects of the antidepressants reboxetine, fluoxetine, and moclobemide in a modified forced swim test following chronic treatment.

    Science.gov (United States)

    Cryan, John F; Page, Michelle E; Lucki, Irwin

    2005-11-01

    The forced swim test (FST) is the most widely used model for assessing potential antidepressant activity in rodents following acute or short-term treatment. However, few studies have compared the effects of short- and long-term antidepressant treatment on behaviors in the test, despite the need to treat patients chronically to produce clinical effects. The current studies examined whether antidepressants from different classes produce different behavioral effects following short-term treatment and whether such effects change following administration for a longer duration. The effects of administering short-term (3 days) and long-term (14 days) treatments of antidepressants from three different chemical classes with distinct mechanisms of action via osmotic minipump were examined: the selective norepinephrine reuptake inhibitor reboxetine (10 and 60 mg kg(-1) day(-1)), the selective serotonin reuptake inhibitor fluoxetine (2.5 and 15 mg kg(-1) day(-1)), and the reversible inhibitor of monoamine oxidase moclobemide (2.5 and 15 mg kg(-1) day(-1)). All testing was carried out in a 15-min test with no preswim session in order to negate any confounding aspect of an induction procedure. The majority of antidepressant-sensitive behavioral changes were observed in the first 5 min of the test. The low dose of reboxetine failed to alter behavior in the test after 3 days but significantly decreased immobility and increased climbing behavior following administration for 14 days, whereas the high dose of reboxetine was equally effective following 3 and 14 days of treatment. In a similar fashion, the low dose of fluoxetine failed to alter behavior in the test following 3 days, but showed an augmented response on immobility and increased swimming following administration for 14 days. The high dose of fluoxetine was slightly more effective at reducing immobility following administration for 14 days than 3 days. The low dose of moclobemide decreased immobility and increased climbing

  10. A Angústia pela Diferença em At Swim, Two Boys de Jamie O'Neill

    Directory of Open Access Journals (Sweden)

    Victor Augusto da Cruz Pacheco

    2016-12-01

    Full Text Available By reading the critical bibliography on contemporary Irish novel At Swim, Two Boys (2001 by Jamie O'Neill, it was noticed that the critics pointed to a relationship with the work of James Joyce, without a detailed comparative analysis between both writers. With that, the article proposes to analyze the construction of Eveline MacMurrough compared with the short story "Eveline" from the book Dubliners (1914 by James Joyce. Based on the theoretical work on intertextuality and the idea of "anxiety of influence" proposed by the American critic Harold Bloom, the article dialogues critically with these essays and the bibliography of At Swim, Two Boys, proposing that the literary re-creation in the novel is based on an anxiety of difference, showing the artistic elaboration made by the Irish writer Jamie O'Neill. From this anxiety, one realizes that the main motivation for the intertextuality is the renewal of the corporeal representation of Ireland.

  11. Swimming with multiple propulsors: measurement and comparison of swimming gaits in three species of neotropical cichlids.

    Science.gov (United States)

    Feilich, Kara L

    2017-11-15

    Comparative studies of fish swimming have been limited by the lack of quantitative definitions of fish gaits. Traditionally, steady swimming gaits have been defined categorically by the fin or region of the body that is used as the main propulsor and named after major fish clades (e.g. carangiform, anguilliform, balistiform, labriform). This method of categorization is limited by the lack of explicit measurements, the inability to incorporate contributions of multiple propulsors and the inability to compare gaits across different categories. I propose an alternative framework for the definition and comparison of fish gaits based on the propulsive contribution of each structure (body and/or fin) being used as a propulsor relative to locomotor output, and demonstrate the effectiveness of this framework by comparing three species of neotropical cichlids with different body shapes. This approach is modular with respect to the number of propulsors considered, flexible with respect to the definition of the propulsive inputs and the locomotor output of interest, and designed explicitly to handle combinations of propulsors. Using this approach, gait can be defined as a trajectory through propulsive space, and gait transitions can be defined as discontinuities in the gait trajectory. By measuring and defining gait in this way, patterns of clustering corresponding to existing categorical definitions of gait may emerge, and gaits can be rigorously compared across categories. © 2017. Published by The Company of Biologists Ltd.

  12. Breaking the Myth That Relay Swimming Is Faster Than Individual Swimming.

    Science.gov (United States)

    Skorski, Sabrina; Etxebarria, Naroa; Thompson, Kevin G

    2016-04-01

    To investigate if swimming performance is better in a relay race than in the corresponding individual race. The authors analyzed 166 elite male swimmers from 15 nations in the same competition (downloaded from www.swimrankings.net). Of 778 observed races, 144 were Olympic Games performances (2000, 2004, 2012), with the remaining 634 performed in national or international competitions. The races were 100-m (n = 436) and 200-m (n = 342) freestyle events. Relay performance times for the 2nd-4th swimmers were adjusted (+ 0.73 s) to allow for the "flying start." Without any adjustment, mean individual relay performances were significantly faster for the first 50 m and overall time in the 100-m events. Furthermore, the first 100 m of the 200-m relay was significantly faster (P > .001). During relays, swimmers competing in 1st position did not show any difference compared with their corresponding individual performance (P > .16). However, swimmers competing in 2nd-4th relay-team positions demonstrated significantly faster times in the 100-m (P individual events (P team positions were adjusted for the flying start no differences were detected between relay and individual race performance for any event or split time (P > .17). Highly trained swimmers do not swim (or turn) faster in relay events than in their individual races. Relay exchange times account for the difference observed in individual vs relay performance.

  13. [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.

  14. Repeated rat-forced swim test: reducing the number of animals to evaluate gradual effects of antidepressants.

    Science.gov (United States)

    Mezadri, T J; Batista, G M; Portes, A C; Marino-Neto, J; Lino-de-Oliveira, C

    2011-02-15

    The forced swim test (FST) is a pre-clinical test to short and long term treatment with antidepressant drugs (ADT), which requires between-subject designs. Herein a modified protocol of the FST using within-subject design (repeated rat-FST) was evaluated. Male Wistar rats were submitted to 15 min of swimming (Day 1: pretest) followed by three subsequent 5 min-swimming tests one week apart (Day 2: test, Day 7: retest 1, Day 14: retest 2). To determine the temporal and factorial characteristics of the variables scored in the repeated rat-FST, the protocol was carried out in untreated animals (E1). To validate the method, daily injections of Fluoxetine (FLX, 2.5mg/kg, i.p.) or saline were given over a 2-week period (E2). Tests and retests have been videotaped for further register of the latency, frequency and duration of behaviors. Over retesting the latency to immobility decreased whereas duration of immobility tended to increase. Factorial analysis revealed that the test, the retest 1 as well as the retest 2 have variables suitable to detection of antidepressant-like effects of ADT. Compared to saline, FLX chronically administrated reduced duration of immobility whereas increased duration of swimming in retest 2. The data suggest that repeated rat-FST detected the gradual increase in the efficacy of low doses of FLX over time. Therefore, repeated rat-FST seemed suitable to detect short and long term effects of selective serotonin reuptake inhibitors, or other ADT, thus reducing the number of animals used in the screenings of this type of compounds. © 2010 Elsevier B.V. All rights reserved.

  15. Fish-robot interactions in a free-swimming environment: Effects of speed and configuration of robots on live fish

    Science.gov (United States)

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

    2014-03-01

    We explore fish-robot interactions in a comprehensive set of experiments designed to highlight the effects of speed and configuration of bioinspired robots on live zebrafish. The robot design and movement is inspired by salient features of attraction in zebrafish and includes enhanced coloration, aspect ratio of a fertile female, and carangiform/subcarangiformlocomotion. The robots are autonomously controlled to swim in circular trajectories in the presence of live fish. Our results indicate that robot configuration significantly affects both the fish distance to the robots and the time spent near them.

  16. Impaired swim bladder inflation in early-life stage fathead ...

    Science.gov (United States)

    The present study investigated whether inhibition of deiodinase, the enzyme which converts thyroxine (T4) to the more biologically-active form, 3,5,3'-triiodothyronine (T3), would impact inflation of the posterior and/or anterior chamber of the swim bladder, processes previously demonstrated to be thyroid-hormone regulated. Two experiments were conducted using a model deiodinase inhibitor, iopanoic acid (IOP). In the first study, fathead minnow (Pimephales promelas) embryos were exposed to 0.6, 1.9, or 6.0 mg IOP/L or control water in a flow-through system until reaching 6 days post-fertilization (dpf) at which time posterior swim bladder inflation was assessed. To examine effects on anterior swim bladder inflation, a second study was conducted with 6 dpf larvae exposed to the same IOP concentrations until reaching 21 dpf. Fish from both studies were sampled for T4/T3 measurements, gene transcription analyses, and thyroid histopathology. In the embryo study, incidence and length of inflated posterior swim bladders were significantly reduced in the 6.0 mg/L treatment at 6 dpf. Incidence of inflation and length of anterior swim bladder in larval fish were significantly reduced in all IOP treatments at 14 dpf, but inflation recovered by 18 dpf. Throughout the larval study, whole body T4 concentrations were significantly increased and T3 concentrations were significantly decreased in all IOP treatments. Consistent with hypothesized compensatory responses, sig

  17. On the swimming motion of spheroidal magnetotactic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cui Zhen; Kong Dali; Zhang Keke [Department of Mathematical Sciences, University of Exeter, Exeter EX4 4QF (United Kingdom); Pan Yongxin, E-mail: kzhang@ex.ac.uk [Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing (China)

    2012-10-15

    We investigate, via both theoretical and experimental methods, the swimming motion of magnetotactic bacteria having the shape of an elongated prolate spheroid in a viscous liquid under the influence of an imposed magnetic field. A fully three-dimensional Stokes flow, driven by the translation and rotation of a swimming bacterium, exerts a complicated viscous drag/torque on the motion of a non-spherical bacterium. By assuming that the body of the bacterium is non-deformable and that the interaction between different bacteria is weak and hence negligible, we have derived a system of 12 coupled nonlinear ordinary differential equations that govern both the motion and the orientation of a swimming spheroidal magnetotactic bacterium. The focus of the study is on how the shape of a non-spherical magnetotactic bacterium, marked by the size of its eccentricity, affects the pattern of its swimming motion. It is revealed that the pattern/speed of a swimming spheroidal magnetotactic bacterium is highly sensitive not only to the direction of its magnetic moment but also to its shape. We also compare the theoretical pattern obtained from the solutions of the 12 coupled differential equations with that observed in the laboratory experiments using the magnetotactic bacteria found in Lake Miyun near Beijing, China, showing that the observed pattern can be largely reproduced with an appropriate set of parameters in our theoretical model. (paper)

  18. Swimming mechanics and propulsive efficiency in the chambered nautilus

    Science.gov (United States)

    Neil, Thomas R.; Askew, Graham N.

    2018-02-01

    The chambered nautilus (Nautilus pompilius) encounters severe environmental hypoxia during diurnal vertical movements in the ocean. The metabolic cost of locomotion (Cmet) and swimming performance depend on how efficiently momentum is imparted to the water and how long on-board oxygen stores last. While propulsive efficiency is generally thought to be relatively low in jet propelled animals, the low Cmet in Nautilus indicates that this is not the case. We measured the wake structure in Nautilus during jet propulsion swimming, to determine their propulsive efficiency. Animals swam with either an anterior-first or posterior-first orientation. With increasing swimming speed, whole cycle propulsive efficiency increased during posterior-first swimming but decreased during anterior-first swimming, reaching a maximum of 0.76. The highest propulsive efficiencies were achieved by using an asymmetrical contractile cycle in which the fluid ejection phase was relatively longer than the refilling phase, reducing the volume flow rate of the ejected fluid. Our results demonstrate that a relatively high whole cycle propulsive efficiency underlies the low Cmet in Nautilus, representing a strategy to reduce the metabolic demands in an animal that spends a significant part of its daily life in a hypoxic environment.

  19. Study on water evaporation rate from indoor swimming pools

    Directory of Open Access Journals (Sweden)

    Rzeźnik Ilona

    2017-01-01

    Full Text Available The air relative humidity in closed spaces of indoor swimming pools influences significantly on users thermal comfort and the stability of the building structure, so its preservation on suitable level is very important. For this purpose, buildings are equipped with HVAC systems which provide adequate level of humidity. The selection of devices and their technical parameters is made using the mathematical models of water evaporation rate in the unoccupied and occupied indoor swimming pool. In the literature, there are many papers describing this phenomena but the results differ from each other. The aim of the study was the experimental verification of published models of evaporation rate in the pool. The tests carried out on a laboratory scale, using model of indoor swimming pool, measuring 99cm/68cm/22cm. The model was equipped with water spray installation with six nozzles to simulate conditions during the use of the swimming pool. The measurements were made for conditions of sports pools (water temperature 24°C and recreational swimming pool (water temperature 34°C. According to the recommendations the air temperature was about 2°C higher than water temperature, and the relative humidity ranged from 40% to 55%. Models Shah and Biasin & Krumm were characterized by the best fit to the results of measurements on a laboratory scale.

  20. On the swimming motion of spheroidal magnetotactic bacteria

    International Nuclear Information System (INIS)

    Cui Zhen; Kong Dali; Zhang Keke; Pan Yongxin

    2012-01-01

    We investigate, via both theoretical and experimental methods, the swimming motion of magnetotactic bacteria having the shape of an elongated prolate spheroid in a viscous liquid under the influence of an imposed magnetic field. A fully three-dimensional Stokes flow, driven by the translation and rotation of a swimming bacterium, exerts a complicated viscous drag/torque on the motion of a non-spherical bacterium. By assuming that the body of the bacterium is non-deformable and that the interaction between different bacteria is weak and hence negligible, we have derived a system of 12 coupled nonlinear ordinary differential equations that govern both the motion and the orientation of a swimming spheroidal magnetotactic bacterium. The focus of the study is on how the shape of a non-spherical magnetotactic bacterium, marked by the size of its eccentricity, affects the pattern of its swimming motion. It is revealed that the pattern/speed of a swimming spheroidal magnetotactic bacterium is highly sensitive not only to the direction of its magnetic moment but also to its shape. We also compare the theoretical pattern obtained from the solutions of the 12 coupled differential equations with that observed in the laboratory experiments using the magnetotactic bacteria found in Lake Miyun near Beijing, China, showing that the observed pattern can be largely reproduced with an appropriate set of parameters in our theoretical model. (paper)

  1. Energetics of swimming by the ferret: consequences of forelimb paddling.

    Science.gov (United States)

    Fish, Frank E; Baudinette, Russell V

    2008-06-01

    The domestic ferret (Mustela putorius furo) swims by alternate strokes of the forelimbs. This pectoral paddling is rare among semi-aquatic mammals. The energetic implications of swimming by pectoral paddling were examined by kinematic analysis and measurement of oxygen consumption. Ferrets maintained a constant stroke frequency, but increased swimming speed by increasing stroke amplitude. The ratio of swimming velocity to foot stroke velocity was low, indicating a low propulsive efficiency. Metabolic rate increased linearly with increasing speed. The cost of transport decreased with increasing swimming speed to a minimum of 3.59+/-0.28 J N(-1) m(-1) at U=0.44 m s(-1). The minimum cost of transport for the ferret was greater than values for semi-aquatic mammals using hind limb paddling, but lower than the minimum cost of transport for the closely related quadrupedally paddling mink. Differences in energetic performance may be due to the amount of muscle recruited for propulsion and the interrelationship hydrodynamic drag and interference between flow over the body surface and flow induced by propulsive appendages.

  2. Distance Teaching on Bornholm

    DEFF Research Database (Denmark)

    Hansen, Finn J. S.; Clausen, Christian

    2001-01-01

    The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology and the organi......The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology...

  3. Femtosecond frequency comb based distance measurement in air

    NARCIS (Netherlands)

    Balling, P.; Kren, P.; Masika, P.; van den Berg, S.A.

    2009-01-01

    Interferometric measurement of distance using a femtosecond frequency comb is demonstrated and compared with a counting interferometer displacement measurement. A numerical model of pulse propagation in air is developed and the results are compared with experimental data for short distances. The

  4. Theoretical Principles of Distance Education.

    Science.gov (United States)

    Keegan, Desmond, Ed.

    This book contains the following papers examining the didactic, academic, analytic, philosophical, and technological underpinnings of distance education: "Introduction"; "Quality and Access in Distance Education: Theoretical Considerations" (D. Randy Garrison); "Theory of Transactional Distance" (Michael G. Moore);…

  5. Just Keep Swimming: Neuroendocrine, Metabolic, and Behavioral Changes After a Forced Swimming Test in Zebrafish.

    Science.gov (United States)

    da Rosa, João Gabriel Santos; Barcellos, Heloísa Helena de Alcântara; Idalencio, Renan; Marqueze, Alessandra; Fagundes, Michele; Rossini, Mainara; Variani, Cristiane; Balbinoti, Francine; Tietböhl, Tássia Michele Huff; Rosemberg, Denis Broock; Barcellos, Leonardo José Gil

    2017-02-01

    In this study, we show that an adaptation of the spinning test can be used as a model to study the exercise-exhaustion-recovery paradigm in fish. This forced swimming test promotes a wide range of changes in the hypothalamus-pituitary-interrenal axis functioning, intermediary metabolism, as well in fish behavior at both exercise and recovery periods. Our results pointed that this adapted spinning test can be considered a valuable tool for evaluating drugs and contaminant effects on exercised fish. This can be a suitable protocol both to environmental-to evaluate contaminants that act in fish energy mobilization and recovery after stressors-and translational perspectives-effects of drugs on exercised or stressed humans.

  6. The role of students’ self-confidence in relation with swimming routines, frequency, and tutor in swimming class

    Science.gov (United States)

    Hartoto, S.; Khory, F. D.; Prakoso, B. B.

    2018-01-01

    It is compulsory for prospective physical education teachers to have the ability to perform swimming. The average of students’ passing in swimming class has reached 72%. Most students who failed to pass the class are those who have had aquaphobia, the condition in which one failed to perceive a situation in a positive and objective, some of which are hard to detect. This perception may come from past experience and it could diminish students’ confidence. Furthermore, the lack of confidence in students may cause unsatisfactory learning results. Therefore it is critical for the teachers to have a comprehensive knowledge of their students’ past experience in formulating a lesson. This research used descriptive qualitative approach. The aim of this article is to investigate the correlation between students’ confidence level and swimming routines, frequency, and tutors in order to succeed swimming class. This article will attempt to describe the results of a research conducted to 139 students of Department of Sport Education Universitas Negeri Surabaya as prospective physical education teachers in Indonesia who took swimming class. Past experience and confidence level are measured by a questionnaire. The results of the research show that students who have a higher level of confidence are those who follow practice routines with adequate frequency and helped by a compatible tutor.

  7. THE IMPACT OF TECHNICAL ABILITY TO SWIMMING PERFORMANCE OF THE MIXED SWIMMING AT 100m IN COLLEGE FASTO

    Directory of Open Access Journals (Sweden)

    Elvira Beganović

    2011-08-01

    Full Text Available The aim of this study was to determine the impact of technical ability to swim (the starting point, the techniques and turns, within each of these techniques of swimming (freestyle, backstroke, breaststroke and butterfly marked as input or predictor variables, the performance of mixed swimming in the 100m, marked as output or criterion variable. The study was conducted on a sample of 31 students, females, aged from 20-24 years, with the help of the testing (assessment, technical skills of swimming (start, the techniques and turns: OCJKSTR, OCJKTEH, OCJKOKR, OCJLSTR, OCJLTEH, OCJLOKR, OCJPSTR, OCJPTEH, OCJPOKR, OCJDSTR, OCJDTEH, OCJDOKR and mixed swimming in the 100m (OCJPM100, the following order: butterfly, back, breaststroke, freestyle. Analyzing the presented results of regression analysis can be stated that after testing (assessment of all predictor system statistically the most significant impact on the criterion variable had the following variables: assessment techniques freestyle (OCJKTEH, evaluation of starting breast stroke (OCJPSTR and assessment of breast stroke turns (OCJPOKR.

  8. 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

  9. The prediction of swimming performance in competition from behavioral information.

    Science.gov (United States)

    Rushall, B S; Leet, D

    1979-06-01

    The swimming performances of the Canadian Team at the 1976 Olympic Games were categorized as being improved or worse than previous best times in the events contested. The two groups had been previously assessed on the Psychological Inventories for Competitive Swimmers. A stepwise multiple-discriminant analysis of the inventory responses revealed that 13 test questions produced a perfect discrimination of group membership. The resultant discriminant functions for predicting performance classification were applied to the test responses of 157 swimmers at the 1977 Canadian Winter National Swimming Championships. Using the same performance classification criteria the accuracy of prediction was not better than chance in three of four sex by performance classifications. This yielded a failure to locate a set of behavioral factors which determine swimming performance improvements in elite competitive circumstances. The possibility of sets of factors which do not discriminate between performances in similar environments or between similar groups of swimmers was raised.

  10. 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.

  11. Further evidence for conditioned taste aversion induced by forced swimming.

    Science.gov (United States)

    Masaki, Takahisa; Nakajima, Sadahiko

    2005-01-31

    A series of experiments with rats reported that aversion to a taste solution can be established by forced swimming in a water pool. Experiment 1 demonstrated that correlation of taste and swimming is a critical factor for this phenomenon, indicating associative (i.e., Pavlovian) nature of this learning. Experiment 2 showed that this learning obeys the Pavlovian law of strength, by displaying a positive relationship between the duration of water immersion in training and the taste aversion observed in subsequent testing. Experiment 3 revealed that swimming rather than being wet is the critical agent, because a water shower did not endow rats with taste aversion. Experiment 4 found that taste aversion was a positive function of water level of the pools in training (0, 12 or 32 cm). These results, taken together, suggest that energy expenditure caused by physical exercise might be involved in the development of taste aversion.

  12. Fast Computing for Distance Covariance

    OpenAIRE

    Huo, Xiaoming; Szekely, Gabor J.

    2014-01-01

    Distance covariance and distance correlation have been widely adopted in measuring dependence of a pair of random variables or random vectors. If the computation of distance covariance and distance correlation is implemented directly accordingly to its definition then its computational complexity is O($n^2$) which is a disadvantage compared to other faster methods. In this paper we show that the computation of distance covariance and distance correlation of real valued random variables can be...

  13. Effects of inorganic mercury on the respiration and the swimming activity of shrimp larvae, Pandalus borealis

    International Nuclear Information System (INIS)

    St-Amand, L.; Gagnon, R.; Packard, T.T.; Savenkoff, C.

    1999-01-01

    In order to test the sensitivity of respiration (physiological and potential) to mercury (Hg) contamination, larval shrimp Pandalus borealis were exposed to inorganic Hg (0-160 ppb) for 27 h in the laboratory. Oxygen consumption rates (RO 2 ), potential respiration (determined by respiratory electron transfer system activity, ETSA), protein content, and swimming activity for zoeae III and zoeae V stages were measured. For both zoeae stages, ETSA and protein content remained constant after 27 h exposure to 160 ppb Hg whereas RO 2 and swimming activity decreased. This study revealed the impact of different Hg levels and different exposure times on RO 2 of shrimp larvae. After 10 h exposure to 160 ppb Hg, the RO 2 decreased by 43 and 49% in zoeae III and zoeae V stages, respectively. Exposure time of 27 h to 80 ppb Hg and higher, induced paralysis in nearly 100% larvae. Surprisingly, the paralysed larvae displayed almost 50% of the control's RO 2 . The results showed that Hg disturbs a part of the respiration process without modifying the maximum activity of the enzymes involved in the ETSA assay. Therefore, the ETSA assay can not be used as a sublethal bioanalytic probe to detect Hg in short-term exposures. The decline of the RO 2 /ETSA ratios reported here, indicates an inability of contaminated larvae to adapt their metabolism to physiological stress caused by Hg. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. The diel vertical migration patterns and individual swimming behavior of overwintering sprat Sprattus sprattus

    KAUST Repository

    Solberg, Ingrid

    2016-11-27

    We addressed the behavioral patterns and DVM dynamics of sprat overwintering in a 150 m Norwegian fjord with increasing hypoxia by depth. An upward-facing echosounder deployed at the bottom and cabled to shore provided 4 months of continuous acoustic data. This enabled detailed studies of individual behavior, specifically allowing assessment of individual vertical migrations at dusk and dawn in relation to light, analysis of so-called rise-and-sink swimming, and investigation of the sprat’ swimming activity and behavior in severely hypoxic waters. Field campaigns supplemented the acoustic studies. The acoustic records showed that the main habitat for sprat was the upper ∼ 65 m where oxygen concentrations were ⩾ 0.7 mL O2 L-1. The sprat schooled at ∼ 50 m during daytime and initiated an upward migration about 1 hour prior to sunset. While some sprat migrated to surface waters, other individuals interrupted the ascent when at ∼20-30 m, and returned to deeper waters ∼ 20-50 min after sunset. Sprat at depth was on average larger, yet individuals made excursions to- and from upper layers. Sprat were swimming in a “rise and sink” pattern at depth, likely related to negative buoyancy. Short-term dives into waters with less than 0.45 mL O2 L-1 were interpreted as feeding forays for abundant overwintering Calanus spp. The deep group of sprat initiated a dawn ascent less than 1 hour before sunrise, ending at 20-30 m where they formed schools. They subsequently returned to deeper waters about ∼20 min prior to sunrise. Measurements of surface light intensities indicated that the sprat experienced lower light levels in upper waters at dawn than at dusk. The vertical swimming speed varied significantly between the behavioral tasks. The mixed DVM patterns and dynamic nocturnal behavior of sprat persisted throughout winter, likely shaped by individual strategies involving optimized feeding and predator avoidance, as well as relating to temperature, hypoxia and

  15. Is Swimming Safe in Heart Failure? A Systematic Review.

    Science.gov (United States)

    Shah, Parin; Pellicori, Pierpaolo; Macnamara, Alexandra; Urbinati, Alessia; Clark, Andrew L

    It is not clear whether swimming is safe in patients with chronic heart failure. Ten studies examining the hemodynamic effects of acute water immersion (WI) (155 patients; average age 60 years; 86% male; mean left ventricular ejection fraction (LVEF) 29%) and 6 randomized controlled trials of rehabilitation comparing swimming with either medical treatment only (n = 3) or cycling (n = 1) or aerobic exercise (n = 2), (136 patients, average age 59 years; 84% male, mean LVEF 31%) were considered. In 7 studies of warm WI (30-35°C): heart rate (HR) fell (2% to -15%), and both cardiac output (CO) (7-37%) and stroke volume (SV) increased (13-41%). In 1 study of hot WI (41°C), systemic vascular resistance (SVR) fell (41%) and HR increased (33%). In 2 studies of cold WI (12-22°C), there were no consistent effects on HR and CO. Compared with medical management, swimming led to a greater increase in peak VO2 (7-14%) and 6 minute walk test (6MWT) (7-13%). Compared with cycle training, combined swimming and cycle training led to a greater reduction in resting HR (16%), a greater increase in resting SV (23%) and SVR (15%), but no changes in resting CO and a lesser increase in peak VO2 (6%). Compared with aerobic training, combined swimming and aerobic training lead to a reduction in resting HR (19%) and SVR (54%) and a greater increase in SV (34%), resting CO (28%), LVEF (9%), and 6MWT (70%). Although swimming appears to be safe, the studies conducted have been small, very heterogeneous, and inconclusive.

  16. 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.

  17. Do swimming goggles limit microbial contamination of contact lenses?

    Science.gov (United States)

    Wu, Yvonne T; Tran, Jess; Truong, Michelle; Harmis, Najat; Zhu, Hua; Stapleton, Fiona

    2011-04-01

    Wearing goggles over contact lenses while swimming is often recommended by eye care professionals. Limited data are available to assess this recommendation. The purpose of this study was to examine whether wearing goggles while swimming limits bacterial colonization on contact lenses and whether the type of lens worn affects contamination rates. Twenty-three subjects underwent two swimming sessions at an ocean (salt water) pool (Maroubra beach Rock Pool, Sydney, Australia). Silicone hydrogel (Ciba Focus Night and Day) or hydrogel lenses (Ciba Focus Daily) were inserted into subjects' eyes before 30 min of swimming sessions, and subjects used modified goggles to mimic goggled and non-goggled conditions. At the end of each session, lenses were collected for microbial investigation. Viable bacterial colonies were classified as gram positive and gram negative and enumerated. The level of bacterial colonization on contact lenses between goggled and non-goggled conditions and between the two lens materials were compared. The range of colony forming units recovered from goggled lenses were 0 to 930 compared with 0 to 1210 on non-goggled lenses. The majority of subjects (16/23) had more microorganisms in the non-goggled condition than when wearing goggles (p = 0.03). Gram negative organisms were found in three non-goggled lenses. No significant difference was shown in the number of bacteria isolated from silicone hydrogel and hydrogel lenses (p > 0.6) irrespective of wearing goggles. Water samples had consistently higher numbers of bacterial counts than those adhered to the lenses; however, no association was found between the number of bacteria in the water sample and those found on the contact lenses. Consistently, fewer bacterial colonies were found on the goggled contact lens, thus suggesting goggles offer some protection against bacterial colonization of contact lenses while swimming. These data would support the recommendation encouraging lens wearers to use goggles

  18. The Fastskin Revolution From Human Fish to Swimming Androids

    Directory of Open Access Journals (Sweden)

    Jennifer Craik

    2011-04-01

    Full Text Available The story of fastskin swimsuits reflects some of the challenges facing the impact of technology in postmodern culture. Introduced in 1999 and ratified for the Sydney 2000 Olympic Games, fastskin swimsuits were touted as revolutionising competitive swimming. Ten years later, they were banned by the world’s swimming regulatory body FINA (the Fédération Internationale de Natation, with the ban taking effect from January 2010 (Shipley 2009. The reason was the controversy caused by the large number of world records that were broken by competitors wearing polyurethane swimsuits, the next generation of the original fast skin suits. These suits were deemed to be providing an artificial advantage by increasing buoyancy and reducing drag. This had been an issue ever since they were introduced, yet FINA had approved the suits and, thereby, unleashed an unstoppable technological revolution of the sport of competitive swimming. Underlying this was the issue about its implications of the transformation of a sport based on the movement of the human body through water without the aid of artificial devices or apparatus. This article argues that the advent of the fastskin has not only transformed the art of swimming but has created a new image of the swimmer as a virtual android rather than a human fish. In turn, the image of the sport of swimming has been re-mapped as a technical artefact and sci-fi spectacle based on a radically transformed concept of the swimming body as a material object that has implications for the ideal of the fashionable body.

  19. Planning with Reachable Distances

    KAUST Repository

    Tang, Xinyu; Thomas, Shawna; Amato, Nancy M.

    2009-01-01

    reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot's number of degrees of freedom. In addition

  20. De-severing distance

    DEFF Research Database (Denmark)

    Jensen, Hanne Louise; de Neergaard, Maja

    2016-01-01

    De-severing Distance This paper draws on the growing body of mobility literature that shows how mobility can be viewed as meaningful everyday practices (Freudendal –Pedersen 2007, Cresswell 2006) this paper examines how Heidegger’s term de-severing can help us understand the everyday coping with ...

  1. The Euclidean distance degree

    NARCIS (Netherlands)

    Draisma, J.; Horobet, E.; Ottaviani, G.; Sturmfels, B.; Thomas, R.R.; Zhi, L.; Watt, M.

    2014-01-01

    The nearest point map of a real algebraic variety with respect to Euclidean distance is an algebraic function. For instance, for varieties of low rank matrices, the Eckart-Young Theorem states that this map is given by the singular value decomposition. This article develops a theory of such nearest

  2. Electromagnetic distance measurement

    CERN Document Server

    1967-01-01

    This book brings together the work of forty-eight geodesists from twenty-five countries. They discuss various new electromagnetic distance measurement (EDM) instruments - among them the Tellurometer, Geodimeter, and air- and satellite-borne systems - and investigate the complex sources of error.

  3. Determining average yarding distance.

    Science.gov (United States)

    Roger H. Twito; Charles N. Mann

    1979-01-01

    Emphasis on environmental and esthetic quality in timber harvesting has brought about increased use of complex boundaries of cutting units and a consequent need for a rapid and accurate method of determining the average yarding distance and area of these units. These values, needed for evaluation of road and landing locations in planning timber harvests, are easily and...

  4. Prospect of Distance Learning

    Science.gov (United States)

    Rahman, Monsurur; Karim, Reza; Byramjee, Framarz

    2015-01-01

    Many educational institutions in the United States are currently offering programs through distance learning, and that trend is rising. In almost all spheres of education a developing country like Bangladesh needs to make available the expertise of the most qualified faculty to her distant people. But the fundamental question remains as to whether…

  5. 80537 based distance relay

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen

    1999-01-01

    A method for implementing a digital distance relay in the power system is described.Instructions are given on how to program this relay on a 80537 based microcomputer system.The problem is used as a practical case study in the course 53113: Micocomputer applications in the power system.The relay...

  6. Feasibility of Serial Saliva Collection for Surveillance of Swimming-Associated Illness

    Science.gov (United States)

    BACKGROUND. The symptoms of many swimming-associated illnesses overlap, and clinical diagnoses often require serum or stool samples. Therefore, it has been difficult to determine the contributions of different etiologic agents to swimming-associated illness. OBJECTIVES. We collec...

  7. Swimming pool attendance and respiratory symptoms and allergies among Dutch children

    NARCIS (Netherlands)

    Jacobs, J.H.; Fuertes, E.; Krop, E.J.M.; Spithoven, J.; Tromp, P.; Heederik, D.J.J.

    2012-01-01

    OBJECTIVES To describe associations among swimming, respiratory health, allergen sensitisation and Clara cell protein 16 (CC16) levels in Dutch schoolchildren. Trichloramine levels in swimming pool air were determined to assess potential exposure levels. METHODS Respiratory health and pool

  8. DEVELOPMENT OF EXPOSURE-RESPONSE RELATIONSHIPS BETWEEN INDICATORS OF WATER QUALITY AND SWIMMING-ASSOCIATED ILLNESS

    Science.gov (United States)

    Exposure to contaminated water during recreational swimming has long been associated with adverse health effects. Swimming in rivers, streams and lakes with high levels of fecal contamination are regularly linked to outbreaks of gastrointestinal illness and related infections. Wh...

  9. 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...... and   during forced activity was also established. During spontaneous activity, 2.5 times more energy was used than in forced swimming at a speed of 0.5 BL s-1. This indicates that spontaneous swimming costs may be considerably higher compared with those of a fixed swimming speed. However, comparing...... 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...

  10. Indoor swimming pool attendance and respiratory and dermal health in schoolchildren: HITEA Catalonia.

    NARCIS (Netherlands)

    Font-Ribera, L.; Villanueva, C.M.; Gracia-Lavedan, E.; Borràs-Santos, A.; Kogevinas, M.; Zock, J.P.

    2014-01-01

    Background: Health benefits of swimming in pools may outweigh adverse health outcomes in children, but evidence from epidemiological studies is scarce or inconclusive for different health outcomes. We evaluated the association between indoor swimming pool attendance during childhood and respiratory

  11. From a distance: implications of spontaneous self-distancing for adaptive self-reflection.

    Science.gov (United States)

    Ayduk, Ozlem; Kross, Ethan

    2010-05-01

    Although recent experimental work indicates that self-distancing facilitates adaptive self-reflection, it remains unclear (a) whether spontaneous self-distancing leads to similar adaptive outcomes, (b) how spontaneous self-distancing relates to avoidance, and (c) how this strategy impacts interpersonal behavior. Three studies examined these issues demonstrating that the more participants spontaneously self-distanced while reflecting on negative memories, the less emotional (Studies 1-3) and cardiovascular (Study 2) reactivity they displayed in the short term. Spontaneous self-distancing was also associated with lower emotional reactivity and intrusive ideation over time (Study 1). The negative association between spontaneous self-distancing and emotional reactivity was mediated by how participants construed their experience (i.e., less recounting relative to reconstruing) rather than avoidance (Studies 1-2). In addition, spontaneous self-distancing was associated with more problem-solving behavior and less reciprocation of negativity during conflicts among couples in ongoing relationships (Study 3). Although spontaneous self-distancing was empirically related to trait rumination, it explained unique variance in predicting key outcomes. 2010 APA, all rights reserved

  12. Operator product expansion in QCD at short distance. Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, S

    1984-03-19

    We describe a simple momentum-space method of evaluating Wilson coefficients of gluon operators in an operator product expansion (OPE). This extends an earlier configuration-space method suitable for calculating the coefficients for light quarks. The method is illustrated by calculating the coefficients of the Lorentz scalar gluon operator of dimension four appearing in different two-point functions.

  13. Quantum chromodynamics and hadronic interactions at short distances

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Huang, T.; Lepage, G.P.

    1982-01-01

    The main purpose of this lecture is to begin to extend QCD phenomenology by taking into account the physics of hadronic wavefunctions. The eventual goal is to obtain a parametrization of the wavefunctions which will bridge the gap between the non-perturbative and perturbative aspects of QCD. The lack of knowledge of hadronic matrix elements is the main difficulty in computing and normalizing dynamical higher twist contributions for many processes

  14. The transverse spin structure of the pion at short distances

    International Nuclear Information System (INIS)

    Diehl, Markus; Szymanowski, Lech; Ecole Polytechnique, CNRS, Palaiseau; Paris-Sud Univ., CNRS, Orsay

    2010-03-01

    We study the form factors of the quark tensor currents in the pion at large squared momentum transfer Q 2 . It turns out that certain form factors can be evaluated using collinear factorization, whereas others receive important contributions from the end-point regions of the longitudinal quark momenta in the pion. We derive simple analytic expressions for the dominant terms at high Q 2 and illustrate them numerically. (orig.)

  15. Electron and photon, short distance nuclei observation tools

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    State of nucleus and nuclear force models -at low energy meson exchange, at high: quark theory- and their limits are recalled, the authors strike quickly the balance of electron and photon beam contribution to the nucleus knowledge. Numerous problems still exist related to nuclear interactions: the next electron accelerator generation should allow to give an answer. Their characteristics will extend the investigation field to the greatest part of the transition zone: nucleon + meson → quark, together with the nuclear phenomena related to Δ resonance [fr

  16. The transverse spin structure of the pion at short distances

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus, E-mail: mdiehl@mail.desy.d [Deutsches Elektronen-Synchroton DESY, 22603 Hamburg (Germany); Szymanowski, Lech [Soltan Institute for Nuclear Studies, Warsaw (Poland); Centre de Physique Theorique, Ecole Polytechnique, CNRS, 91128 Palaiseau (France); Laboratoire de Physique Theorique, Universite Paris-Sud, CNRS, 91405 Orsay (France)

    2010-06-14

    We study the form factors of the quark tensor currents in the pion at large squared momentum transfer Q{sup 2}. It turns out that certain form factors can be evaluated using collinear factorization, whereas others receive important contributions from the end-point regions of the longitudinal quark momenta in the pion. We derive simple analytic expressions for the dominant terms at high Q{sup 2} and illustrate them numerically.

  17. The transverse spin structure of the pion at short distances

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Szymanowski, Lech [Soltan Inst. for Nuclear Studies, Warsaw (Poland); Ecole Polytechnique, CNRS, Palaiseau (France). Centre de Physique Theorique; Paris-Sud Univ., CNRS, Orsay (France). Lab. de Physique Theorique

    2010-03-15

    We study the form factors of the quark tensor currents in the pion at large squared momentum transfer Q{sup 2}. It turns out that certain form factors can be evaluated using collinear factorization, whereas others receive important contributions from the end-point regions of the longitudinal quark momenta in the pion. We derive simple analytic expressions for the dominant terms at high Q{sup 2} and illustrate them numerically. (orig.)

  18. Factorization for short distance hadron-hadron scattering

    International Nuclear Information System (INIS)

    Collins, J.C.; Illinois Inst. of Tech., Chicago; Soper, D.E.; Sterman, G.

    1985-01-01

    We show that factorization holds at leading twist in the Drell-Yang cross section dsigma/dQ 2 dy and related inclusive hadron-hadron cross sections. We review the heuristic arguments for factorization, as well as the difficulties which must be overcome in a proof. We go on to give detailed arguments for the all order cancellation of soft gluons, and to show how this leads to factorization. (orig.)

  19. Short-distance Schwinger-mechanism and chiral symmetry

    DEFF Research Database (Denmark)

    McGady, David A.; Brogård, Jon

    2017-01-01

    rates depend only on the ratio between the capacitor plate separation, $\\ell$, and the length-scale of the force-field, $\\ell_F$. Chirality ensures that fermion production smoothly vanishes with $\\ell/\\ell_F$. Scalar pair production though diverges exponentially quickly in this limit. The same limit...... of the smooth tanh-potential does not diverge; divergences seem tied to singularities in current and charge densities....

  20. Nuclear phenomena and the short distance structure of hadrons

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1979-09-01

    In certain cases, nuclear corrections to hadronic phenomena depend in detail on the nature of quark and gluon interactions, as well as the effects of jet development within the nuclear medium. Applications of quantum chromodynamics to fast particle production in nuclear collisions, nuclear form factors, and shadowing in deep inelastic lepton processes are reviewed. Also discussed is a new approach to particle production in hadron-nucleus, nucleus-nucleus and deep-inelastic nuclear reactions from the standpoint of a color-neutralization model. 74 references

  1. Polarization asymmetries and gauge theory interactions at short distances

    International Nuclear Information System (INIS)

    Craigie, N.S.

    1983-01-01

    In this talk, we give the arguments as to why spin asymmetries test fundamental properties of the underlying gauge theories of elementary particles, concentrating mainly on electro-weak and QCD interactions, but also looking at the future and possible signatures for supersymmetric strong interactions. We also mention briefly the role helicity asymmetry measurements can play as regards higher order corrections, including higher twist, in QCD. (orig./HSI)

  2. Psychostimulants and forced swim stress interaction: how activation of the hypothalamic-pituitary-adrenal axis and stress-induced hyperglycemia are affected.

    Science.gov (United States)

    Gagliano, Humberto; Ortega-Sanchez, Juan Antonio; Nadal, Roser; Armario, Antonio

    2017-10-01

    We recently reported that simultaneous exposure to amphetamine and various stressors resulted in reduced hypothalamic-pituitary-adrenal (HPA) and glycemic responses to the stressors. Since this is a new and relevant phenomenon, we wanted to further explore this interaction. This study aims (i) to characterize the effect of various doses of amphetamine on the physiological response to a predominantly emotional stressor (forced swim) when the drug was given immediately before stress; (ii) to study if an interaction appears when the drug was given 30 min or 7 days before swim; and (iii) to know whether cocaine causes similar effects when given just before stress. Adult male rats were used and plasma levels of ACTH, corticosterone, and glucose were the outcomes. Amphetamine caused a dose-dependent activation of the HPA axis, but all doses reduced HPA and glycemic responses to swim when given just before the stressor. Importantly, during the post-swim period, the stressor potently inhibited the ACTH response to amphetamine, demonstrating mutual inhibition between the two stimuli. The highest dose of amphetamine also reduced the response to swim when given 30 min before stress, whereas it caused HPA sensitization when given 7 days before. Cocaine also reduced stress-induced HPA activation when given just before swim. The present results demonstrate a negative synergy between psychostimulants (amphetamine and cocaine) and stress regarding HPA and glucose responses when rats were exposed simultaneously to both stimuli. The inhibitory effect of amphetamine is also observed when given shortly before stress, but not some days before.

  3. SWIMS, Sigmund and Winterbon Multiple Scattering of Ion Beams

    International Nuclear Information System (INIS)

    Eyeberger, L.

    1999-01-01

    1 - Description of program or function - SWIMS calculates the angular dispersion of ion beams that undergo small-angle, incoherent multiple scattering by gaseous or solid media. 2 - Method of solution - SWIMS uses the tabulated angular distributions of Sigmund and Winterbon for a Thomas-Fermi screened Coulomb potential. The fraction of the incident beam scattered into a cone defined by the polar angle is computed as a function of that angle for a reduced thickness over the rang of 0.01 to 10

  4. Cryptosporidium and Giardia in Swimming Pools, Atlanta, Georgia

    Centers for Disease Control (CDC) Podcasts

    2008-05-29

    In this podcast, Dan Rutz speaks with Dr. Joan Shields, a guest researcher with the Healthy Swimming Program at CDC, about an article in June 2008 issue of Emerging Infectious Diseases reporting on the results of a test of swimming pools in the greater Atlanta, Georgia area. Dr. Shields tested 160 pools in metro Atlanta last year for Cryptosporidium and Giardia. These germs cause most recreational water associated outbreaks.  Created: 5/29/2008 by Emerging Infectious Diseases.   Date Released: 5/29/2008.

  5. Short communication

    African Journals Online (AJOL)

    Pranisha

    2014-12-11

    Dec 11, 2014 ... eliminate a contributory factor to PSE meat in South Africa. Transport over long distances to ... Keywords: MH gene, halothane gene, PSE meat, ryanodine receptor, seed stock herds ..... In vitro PNMR studies on biopsy skeletal ...

  6. PREFACE: Swimming at low Reynolds numbers—motility of micro-organisms Swimming at low Reynolds numbers—motility of micro-organisms

    Science.gov (United States)

    Garstecki, Piotr; Cieplak, Marek

    2009-05-01

    another striking feature of the microbial motility—at low values of the Reynolds number the hydrodynamic interactions are long range on the scale of the swimmer. This leads to conditions that are surprising for a macroswimmer—nobody swimming in a pool expects to be affected by the activity of another swimmer separated by a distance of, say, 30 lengths of a typical body (50 meters for humans). Yet at the microscale this is exactly what happens, and this feature leads to very interesting effects of interaction between swimmers, and between swimmers and solid walls. Felderhof [10] discusses the hydrodynamic interactions of a 'peristaltic sheet' with the proximate walls or with a second sheet, while Hernandez-Ortiz et al elaborate on the physical mechanisms behind one of the most fascinating behaviors of micro-organisms—collective swimming [11]. Recently, new stimuli in the research of motility of micro-organisms came from the experimental realizations of motile microstructures—artificial microswimmers. An important contribution here comes from Dreyfus et al who showed a micro-scale swimmer comprised of elastically linked colloidal particles [12]. In this issue, Alexander et al [13] discuss a similar model of Najafi and Golestanian [14] and analyze the interactions between such swimmers. Coq et al [15] investigate a different mechanism of swimming and report on the most important 'organelle' of structures that propel by rotating a helical element—they discuss the mechanics of a rotated elastic rod. Depending on the type of forcing, the rod, when subject to an increasing torque, either smoothly transforms into an increasingly deformed helical shape providing growing net flow in the direction of rotation, or shows a discontinuous transition of the shape with a sudden change in the efficiency of propulsion. Finally, Garstecki et al [16]demonstrate experimentally elastic artificial microswimmers powered by an external rotating magnetic field. They show that in order to

  7. Changes over swim lessons in parents' perceptions of children's supervision needs in drowning risk situations: "His swimming has improved so now he can keep himself safe".

    Science.gov (United States)

    Morrongiello, Barbara A; Sandomierski, Megan; Spence, Jeffrey R

    2014-07-01

    The aim of this longitudinal study was to determine how children's participation in swim lessons impacts parents' appraisals of children's drowning risk and need for supervision. Parents with 2-5-year old children enrolled in community swim lessons completed the same survey measures up to 4 times over an 8-month period. Multilevel regression analyses examining temporal relationships between parents' perceptions of their child's swim ability, supervision needs around water, and children's ability to keep themselves safe in drowning risk situations revealed that as children progressed through swim lessons, parents' perceptions of their child's swim ability and their belief that children are capable of keeping themselves safe around water increased. Further, the relation between parents' perceptions of swim ability and judgments of children's supervision needs was mediated through parents' judgment about their child's ability to secure their own safety near water. As parents perceive their child to be accumulating swim skills, they increasingly believe that children are capable of keeping themselves from drowning, and as a result, that less active parent supervision of their child is necessary. Implications of these findings for intervention efforts to counter this unwelcome way of thinking that may arise through continued participation in swim lessons are discussed. Incorporating a parent-focused component into children's learn-to-swim programs to promote more realistic appraisals of children's supervision needs and drowning risks may further enhance the positive benefits that swim lessons have for children's safety.

  8. Swimming black-crowned night-herons (Nycticorax nycticorax) Kleptoparasitize American coots (Fulica americana)

    DEFF Research Database (Denmark)

    Graves, Gary R.

    2015-01-01

    I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid.......I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid....

  9. Mathematical modelling and simulation of the thermal performance of a solar heated indoor swimming pool

    OpenAIRE

    Mančić Marko V.; Živković Dragoljub S.; Milosavljević Peđa M.; Todorović Milena N.

    2014-01-01

    Buildings with indoor swimming pools have a large energy footprint. The source of major energy loss is the swimming pool hall where air humidity is increased by evaporation from the pool water surface. This increases energy consumption for heating and ventilation of the pool hall, fresh water supply loss and heat demand for pool water heating. In this paper, a mathematical model of the swimming pool was made to assess energy demands of an indoor swimming po...

  10. 76 FR 42048 - Safety Zones; Swimming Events in Captain of the Port Boston Zone

    Science.gov (United States)

    2011-07-18

    ...-AA00 Safety Zones; Swimming Events in Captain of the Port Boston Zone AGENCY: Coast Guard, DHS. ACTION... events within the Captain of the Port (COTP) Boston Zone for swimming events. This action is necessary to... property on navigable waters from the hazardous nature of swimming events such as large numbers of swimmers...

  11. Schooling reduces energy consumption in swimming male European eels, Anguilla anguilla L.

    NARCIS (Netherlands)

    Burgerhout, E.; Tudorache, C.; Brittijn, S.A.; Palstra, A.P.; Dirks, R.P.; Thillart, G.E.E.J.M.

    2013-01-01

    During migration, swimming in schools provides fish with a number of behavioural and ecological advantages, including increased food supply and reduced predation risk. Previous work shows that carangiform and tunniform swimming result in energetic advantages for individuals using a diamond swimming

  12. Swimming Lessons: Learning, New Materialisms, Posthumanism, and Post Qualitative Research Emerge through a Pool Poem

    Science.gov (United States)

    McKnight, Lucinda

    2016-01-01

    This article shifts from the formal learning spaces of school and university to an Australian public swimming pool to playfully engage some of the dilemmas that recent theory poses for curriculum studies. The article enacts multiple diffractions (Barad, 2007) as theory becomes swimming and swimming becomes theory, and ideas and movements are…

  13. 77 FR 41271 - Safety Zone; Newburgh to Beacon Swim, Newburgh, Hudson River, NY

    Science.gov (United States)

    2012-07-13

    ... 1625-AA00 Safety Zone; Newburgh to Beacon Swim, Newburgh, Hudson River, NY AGENCY: Coast Guard, DHS... navigable waters of the Hudson River, NY in the vicinity of Newburgh, NY for the annual Newburgh Beacon Swim... Beacon Swim is an annual recurring event that has a permanent safety zone found at 33 CFR 165.160. The...

  14. 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…

  15. 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

    Full Text Available On the sample of 32 fourth grade students of some Belgrade highs schools, who had the physical education classes carried out at the city’s swimming pools, an attempt was made to evaluate the effects of the two different programmes of swimming training in different intensity zones, defi ned relative to the anaerobic threshold. The examinees were divided into two groups out of 15 i.e. 17 participants who were not (according to statistics signifi cantly different in terms of average time and heart frequency during the 400 m swimming test and heart frequency and time measured after 50 m in the moment of reaching the anaerobic threshold. The fi rst training model consisted of swimming at the intensity level within the zone below anaerobic threshold, while the second model involved occasional swimming at a higher intensity sometimes surpassing the anaerobic threshold. The experimentalprogramme with both sub-groups lasted 8 weeks with 3 training sessions per week, 2 ‘of which we’re identical for both experimental groups, with the third one differing regarding the swimming intensity, this in the fi rst group being still in the zone below, and in the second group occasionally in the zone above the anaerobic threshold. The amount of training and the duration were the same in both programmes. The aim of the research , was to evaluate and to compare the effects of the two training models, using as the basic criteria possible changes of average time and heart frequency during the 400 m swimming test and heart frequency and time measured after 50 m in the moment of reaching the anaerobic thereshold. On the basis of the statistical analysis of the obtained data, it is possible to conclude that in both experimental groups there were statistically signifi cant changes of average values concerning all the physiological variables. Although the difference in effi ciency of applied experimental programmes is not defi ned, we can claim that both of experimental

  16. Critical force during tethered swimming for the evaluation of aerobic capacity and prediction of performances in freestyle swimming

    OpenAIRE

    Marcelo Papoti; Ricardo Vitório; Gustavo Gomes Araújo; Luiz Eduardo Barreto Martins; Sérgio Augusto Cunha; Claudio Alexandre Gobatto

    2010-01-01

    The present study investigated the relationship of critical force (Fcrit) with lactate threshold (LLNA) and the intensity corresponding to VO2max (iVO2max) in tethered swimming (TS), and their correlation with maximal performance in 400-m (V400) and 30-min (VT30) freestyle swimming (FS). Seven swimmers were submitted to a TS incremental test for the determination of LLNA and iVO2max. For the determination of Fcrit, the swimmers performed four exercises to exhaustion at intensities (F) corresp...

  17. Distance between images

    Science.gov (United States)

    Gualtieri, J. A.; Le Moigne, J.; Packer, C. V.

    1992-01-01

    Comparing two binary images and assigning a quantitative measure to this comparison finds its purpose in such tasks as image recognition, image compression, and image browsing. This quantitative measurement may be computed by utilizing the Hausdorff distance of the images represented as two-dimensional point sets. In this paper, we review two algorithms that have been proposed to compute this distance, and we present a parallel implementation of one of them on the MasPar parallel processor. We study their complexity and the results obtained by these algorithms for two different types of images: a set of displaced pairs of images of Gaussian densities, and a comparison of a Canny edge image with several edge images from a hierarchical region growing code.

  18. THE EXTRAGALACTIC DISTANCE DATABASE

    International Nuclear Information System (INIS)

    Tully, R. Brent; Courtois, Helene M.; Jacobs, Bradley A.; Rizzi, Luca; Shaya, Edward J.; Makarov, Dmitry I.

    2009-01-01

    A database can be accessed on the Web at http://edd.ifa.hawaii.edu that was developed to promote access to information related to galaxy distances. The database has three functional components. First, tables from many literature sources have been gathered and enhanced with links through a distinct galaxy naming convention. Second, comparisons of results both at the levels of parameters and of techniques have begun and are continuing, leading to increasing homogeneity and consistency of distance measurements. Third, new material is presented arising from ongoing observational programs at the University of Hawaii 2.2 m telescope, radio telescopes at Green Bank, Arecibo, and Parkes and with the Hubble Space Telescope. This new observational material is made available in tandem with related material drawn from archives and passed through common analysis pipelines.

  19. Distance to Cure

    OpenAIRE

    Capachi, Casey

    2013-01-01

    Distance to Cure A three-part television series by Casey Capachi www.distancetocure.com   Abstract   How far would you go for health care? This three-part television series, featuring two introductory segments between each piece, focuses on the physical, cultural, and political obstacles facing rural Native American patients and the potential of health technology to break down those barriers to care.   Part one,Telemedici...

  20. Ultrametric Distance in Syntax

    Directory of Open Access Journals (Sweden)

    Roberts Mark D.

    2015-04-01

    Full Text Available Phrase structure trees have a hierarchical structure. In many subjects, most notably in taxonomy such tree structures have been studied using ultrametrics. Here syntactical hierarchical phrase trees are subject to a similar analysis, which is much simpler as the branching structure is more readily discernible and switched. The ambiguity of which branching height to choose, is resolved by postulating that branching occurs at the lowest height available. An ultrametric produces a measure of the complexity of sentences: presumably the complexity of sentences increases as a language is acquired so that this can be tested. All ultrametric triangles are equilateral or isosceles. Here it is shown that X̅ structure implies that there are no equilateral triangles. Restricting attention to simple syntax a minimum ultrametric distance between lexical categories is calculated. A matrix constructed from this ultrametric distance is shown to be different than the matrix obtained from features. It is shown that the definition of C-COMMAND can be replaced by an equivalent ultrametric definition. The new definition invokes a minimum distance between nodes and this is more aesthetically satisfying than previous varieties of definitions. From the new definition of C-COMMAND follows a new definition of of the central notion in syntax namely GOVERNMENT.