Journal articles on the topic 'Aquatic stroke data'
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Marinho-Buzelli, Andresa R., Alison M. Bonnyman, and Mary C. Verrier. "The effects of aquatic therapy on mobility of individuals with neurological diseases: a systematic review." Clinical Rehabilitation 29, no. 8 (November 13, 2014): 741–51. http://dx.doi.org/10.1177/0269215514556297.
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Objective:To summarize evidence on the effects of aquatic therapy on mobility in individuals with neurological diseases.Data sources:MEDLINE, EMBASE, PsycInfo, CENTRAL, CINAHL, SPORTDiscus, PEDro, PsycBITE and OT Seeker were searched from inception to 15 September 2014. Hand-searching of reference lists was performed in the selected studies.Review methods:The search included randomized controlled trials and quasi-experimental studies that investigated the use of aquatic therapy and its effect on mobility of adults with neurological diseases. One reviewer screened titles and abstracts of retrieved studies from the search strategy. Two reviewers independently examined the full texts and conducted the study selection, data extraction and quality assessment. A narrative synthesis of data was applied to summarize information from included studies. The Downs and Black Scale was used to assess methodological quality.Results:A total of 116 articles were obtained for full text eligibility. Twenty studies met the specified inclusion criteria: four Randomized Controlled Trials (RCTs), four non-randomized studies and 12 before-and-after tests. Two RCTs (30 patients with stroke in the aquatic therapy groups), three non-randomized studies and three before-and-after studies showed “fair” evidence that aquatic therapy increases dynamic balance in participants with some neurological disorders. One RCT (seven patients with stroke in the aquatic therapy group) and two before-and-after tests (20 patients with multiple sclerosis) demonstrated “fair” evidence on improvement of gait speed after aquatic therapy.Conclusion:Our synthesis showed “fair” evidence supporting the use of aquatic therapy to improve dynamic balance and gait speed in adults with certain neurological conditions.
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Iliescu, Alice Mary, Amanda McIntyre, Joshua Wiener, Jerome Iruthayarajah, Andrea Lee, Sarah Caughlin, and Robert Teasell. "Evaluating the effectiveness of aquatic therapy on mobility, balance, and level of functional independence in stroke rehabilitation: a systematic review and meta-analysis." Clinical Rehabilitation 34, no. 1 (October 18, 2019): 56–68. http://dx.doi.org/10.1177/0269215519880955.
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Objective: To meta-analyze and systematically review the effectiveness of aquatic therapy in improving mobility, balance, and functional independence after stroke. Data Sources: Articles published in Medline, Embase, CINAHL, PsycINFO, and Scopus up to 20 August 2019. Study Selection: Studies met the following inclusion criteria: (1) English, (2) adult stroke population, (3) randomized or non-randomized prospectively controlled trial (RCT or PCT, respectively) study design, (4) the experimental group received >1 session of aquatic therapy, and (5) included a clinical outcome measure of mobility, balance, or functional independence. Data Extraction: Participant characteristics, treatment protocols, between-group outcomes, point measures, and measures of variability were extracted. Methodological quality was assessed using Physiotherapy Evidence Database (PEDro) tool, and pooled mean differences (MD) ± standard error and 95% confidence intervals (CI) were calculated for Functional Reach Test (FRT), Timed Up and Go Test (TUG), gait speed, and Berg Balance Scale (BBS). Data Synthesis: Nineteen studies (17 RCTs and 2 PCTs) with a mean sample size of 36 participants and mean PEDro score of 5.6 (range 4–8) were included. Aquatic therapy demonstrated statistically significant improvements over land therapy on FRT (MD = 3.511 ± 1.597; 95% CI: 0.381–6.642; P = 0.028), TUG (MD = 2.229 ± 0.513; 95% CI: 1.224–3.234; P < 0.001), gait speed (MD = 0.049 ± 0.023; 95% CI: 0.005–0.094; P = 0.030), and BBS (MD = 2.252 ± 0.552; 95% CI: 1.171–3.334; P < 0.001). Conclusions: While the effect of aquatic therapy on mobility and balance is statistically significant compared to land-based therapy, the clinical significance is less clear, highly variable, and outcome measure dependent.
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Rimkutė, Evelina, Brigita Kreivinienė, Daiva Mockevičienė, Eglė Radzevičienė, Žilvinas Kleiva, and Sonata Mačiulskytė. "THE EFFECT OF THERAPEUTIC ACTIVITIES WITH DOLPHINS FOR BALANCE, GAIT AND QUALITY OF LIFE IN PATIENTS AFTER HEMORRHAGIC STROKE: CASE ANALYSIS." Visuomenės sveikata 29, no. 2 (April 27, 2019): 21–27. http://dx.doi.org/10.5200/sm-hs.2019.012.
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The aim of this research was to assess the effect of dolphin assisted specialized aquatic program applied in rehabilitation of psychomotor functions of persons after hemorrhagic stroke. The research was carried out in 2018 in Lithuania. Two persons with diagnosed hemorrhagic stroke have been surveyed. In the course of the investigation, the effect of aquatic dolphin assisted physical activities on coordination of arms, legs without using balance was assessed; static and dynamic change of dynamics, the effect on gait in water with dolphins were assessed. Additionally, the data on life quality aspects obtained by the SF-36 questionnaire was investigated. It is observed that after application of aquatic dolphin assisted therapeutic activities improvement of both static and dynamic balance has been recorded; three weeks later, most indicators remained the same. The conducted research revealed that therapy had a highly beneficial effect on persons with neurological diseases in terms of assessment of their dynamic balance, gait and gait speed (motor skills) as well as quality of life. Significant changes of motor skills in water in both surveyed individuals have been recorded. Therapeutic aquatic dolphin assisted activities are an effective method to improve the parameters of balance, gait and quality of life in patients; however, psycho-emotional and psycho-social factors, such as support of the social network supplementing continuing therapeutic activities, are a highly significant factor in ensuring further improvement of patient’s condition.
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van Dam, R. P., P. J. Ponganis, K. V. Ponganis, D. H. Levenson, and G. Marshall. "Stroke frequencies of emperor penguins diving under sea ice." Journal of Experimental Biology 205, no. 24 (December 15, 2002): 3769–74. http://dx.doi.org/10.1242/jeb.205.24.3769.
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SUMMARYDuring diving, intermittent swim stroke patterns, ranging from burst/coast locomotion to prolonged gliding, represent potential energy conservation mechanisms that could extend the duration of aerobic metabolism and, hence,increase the aerobic dive limit (ADL, dive duration associated with onset of lactate accumulation). A 5.6 min ADL for emperor penguins had been previously determined with lactate measurements after dives of <50 m depth. In order to assess locomotory patterns during such dives, longitudinal acceleration was measured with an attached accelerometer in 44 dives of seven adult birds diving from an isolated dive hole in the sea ice of McMurdo Sound, Antarctica. Detection of wing strokes in processed accelerometer data was verified in selected birds with analysis of simultaneous Crittercam underwater video footage. Mean dive duration of birds equipped with the accelerometer and a time-depth recorder (TDR) was 5.7±2.2 min; 48% of these dives were greater than the measured 5.6 min ADL (ADLM). Highest stroke frequencies (0.92±0.31 Hz, N=981) occurred during the initial descent to 12 m depth. Swimming effort was reduced to a mean stroke frequency<0.70 Hz during other phases of the dive (while traveling below 12 m depth,during foraging ascents/descents to and from the sub-ice surface, and during final ascents to exit). The longest stroke interval (8.6 s) occurred during a feeding excursion to the undersurface of the ice. In dives>ADLM, mean stroke frequency during travel segments was significantly less than that in dives <ADLM(P<0.05). Mean stroke frequency of the entire dive correlated inversely (P<0.05) with diving duration (r=-0.67) and with mean dive depth (r=-0.43). Emperor penguins did not exhibit any significant (>10 s) periods of prolonged gliding during these shallow(<60 m) foraging dives. However, a stroke/glide pattern was evident with more than 50% of strokes associated with a stroke interval >1.6 s, and with lower stroke frequency associated with increased dive duration.
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Schram, Ben, James Furness, Kevin Kemp-Smith, Jason Sharp, Matthew Cristini, Daniel Harvie, Emma Keady, et al. "A biomechanical analysis of the stand-up paddle board stroke: a comparative study." PeerJ 7 (November 1, 2019): e8006. http://dx.doi.org/10.7717/peerj.8006.
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Background Stand-up paddle boarding (SUP) is a rapidly growing global aquatic sport, with increasing popularity among participants within recreation, competition and rehabilitation. To date, few scientific studies have focused on SUP. Further, there is no research examining the biomechanics of the SUP paddle stroke. The purpose of this study was to investigate whether variations in kinematics existed among experienced and inexperienced SUP participants using three-dimensional motion analysis. This data could be of significance to participants, researchers, coaches and health practitioners to improve performance and inform injury minimization strategies. Methods A cross-sectional observational design study was performed with seven experienced and 19 inexperienced paddlers whereby whole-body kinematic data were acquired using a six-camera Vicon motion capture system. Participants paddled on a SUP ergometer while three-dimensional range of motion (ROM) and peak joint angles were calculated for the shoulders, elbows, hips and trunk. Mann–Whitney U tests were conducted on the non-normally distributed data to evaluate differences between level of expertise. Results Significant differences in joint kinematics were found between experienced and inexperienced participants, with inexperienced participants using greater overall shoulder ROM (78.9° ± 24.9° vs 56.6° ± 17.3°, p = 0.010) and less hip ROM than the experienced participants (50.0° ± 18.5° vs 66.4° ± 11.8°, p = 0.035). Experienced participants demonstrated increased shoulder motion at the end of the paddle stoke compared to the inexperienced participants (74.9° ± 16.3° vs 35.2° ± 28.5°, p = 0.001 minimum shoulder flexion) and more extension at the elbow (6.0° ± 9.2° minimum elbow flexion vs 24.8° ± 13.5°, p = 0.000) than the inexperienced participants. Discussion The results of this study indicate several significant kinematic differences between the experienced and inexperienced SUP participants. These variations in technique were noted in the shoulder, elbow and hip and are evident in other aquatic paddling sports where injury rates are higher in these joints. These finding may be valuable for coaches, therapists and participants needing to maximize performance and minimize injury risk during participation in SUP.
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Skipper, A. N., D. W. Murphy, and D. R. Webster. "Characterization of hop-and-sink daphniid locomotion." Journal of Plankton Research 41, no. 2 (February 25, 2019): 142–53. http://dx.doi.org/10.1093/plankt/fbz003.
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Abstract This study characterizes the hop-and-sink locomotion of Daphnia magna, a zooplankton species widely studied in a variety of biological fields. Time-resolved tomographic particle image velocimetry (tomo-PIV) is used to obtain 3D kinematics and flow field data with high spatial and temporal resolution. The kinematics data show that the daphniid’s velocity quickly increases during the power stroke, reaching maximum accelerations of 1000 body lengths/s2, then decelerates during the recovery stroke to a steady sinking speed. The hop-and-sink locomotion produces a viscous vortex ring located under each second antennae. These flow structures develop during the power stroke, strengthen during the recovery stroke, and then decay slowly during the sinking phase. The time records of vortex circulation are self-similar when properly normalized. The flow fields were successfully modeled using an impulsive stresslet, showing good agreement between the decay of circulation and a conceptual model of the impulse. While no relationships were found between kinematics or flow field parameters and body size, the total energy dissipated by the daphniid hop-and-sink motion was found to scale exponentially with the vortex strength.
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Battista, Nicholas A. "Diving into a Simple Anguilliform Swimmer’s Sensitivity." Integrative and Comparative Biology 60, no. 5 (September 16, 2020): 1236–50. http://dx.doi.org/10.1093/icb/icaa131.
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Synopsis Computational models of aquatic locomotion range from modest individual simple swimmers in 2D to sophisticated 3D multi-swimmer models that attempt to parse collective behavioral dynamics. Each of these models contain a multitude of model input parameters to which its outputs are inherently dependent, that is, various performance metrics. In this work, the swimming performance’s sensitivity to parameters is investigated for an idealized, simple anguilliform swimming model in 2D. The swimmer considered here propagates forward by dynamically varying its body curvature, similar to motion of a Caenorhabditis elegans. The parameter sensitivities were explored with respect to the fluid scale (Reynolds number), stroke (undulation) frequency, as well as a kinematic parameter controlling the velocity and acceleration of each upstroke and downstroke. The input Reynolds number and stroke frequencies sampled were from [450, 2200] and [1, 3] Hz, respectively. In total, 5000 fluid–structure interaction simulations were performed, each with a unique parameter combination selected via a Sobol sequence, in order to conduct global sensitivity analysis. Results indicate that the swimmer’s performance is most sensitive to variations in its stroke frequency. Trends in swimming performance were discovered by projecting the performance data onto particular 2D subspaces. Pareto-like optimal fronts were identified. This work is a natural extension of the parameter explorations of the same model from Battista in 2020.
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Ramamurti, Ravi, William C. Sandberg, Rainald Löhner, Jeffrey A. Walker, and Mark W. Westneat. "Fluid dynamics of flapping aquatic flight in the bird wrasse:three-dimensional unsteady computations with fin deformation." Journal of Experimental Biology 205, no. 19 (October 1, 2002): 2997–3008. http://dx.doi.org/10.1242/jeb.205.19.2997.
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SUMMARY Many fishes that swim with the paired pectoral fins use fin-stroke parameters that produce thrust force from lift in a mechanism of underwater flight. These locomotor mechanisms are of interest to behavioral biologists,biomechanics researchers and engineers. In the present study, we performed the first three-dimensional unsteady computations of fish swimming with oscillating and deforming fins. The objective of these computations was to investigate the fluid dynamics of force production associated with the flapping aquatic flight of the bird wrasse Gomphosus varius. For this computational work, we used the geometry of the wrasse and its pectoral fin,and previously measured fin kinematics, as the starting points for computational investigation of three-dimensional (3-D) unsteady fluid dynamics. We performed a 3-D steady computation and a complete set of 3-D quasisteady computations for a range of pectoral fin positions and surface velocities. An unstructured, grid-based, unsteady Navier—Stokes solver with automatic adaptive remeshing was then used to compute the unsteady flow about the wrasse through several complete cycles of pectoral fin oscillation. The shape deformation of the pectoral fin throughout the oscillation was taken from the experimental kinematics. The pressure distribution on the body of the bird wrasse and its pectoral fins was computed and integrated to give body and fin forces which were decomposed into lift and thrust. The velocity field variation on the surface of the wrasse body, on the pectoral fins and in the near-wake was computed throughout the swimming cycle. We compared our computational results for the steady, quasi-steady and unsteady cases with the experimental data on axial and vertical acceleration obtained from the pectoral fin kinematics experiments. These comparisons show that steady state computations are incapable of describing the fluid dynamics of flapping fins. Quasi-steady state computations, with correct incorporation of the experimental kinematics, are useful when determining trends in force production, but do not provide accurate estimates of the magnitudes of the forces produced. By contrast, unsteady computations about the deforming pectoral fins using experimentally measured fin kinematics were found to give excellent agreement, both in the time history of force production throughout the flapping strokes and in the magnitudes of the generated forces.
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CASEY, TIMOTHY M., and JERI R. HEGEL-LITTLE. "Instantaneous Oxygen Consumption and Muscle Stroke Work in Malacosoma Americanum During Pre-Flight Warm-Up." Journal of Experimental Biology 127, no. 1 (January 1, 1987): 389–400. http://dx.doi.org/10.1242/jeb.127.1.389.
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Instantaneous rates of oxygen consumption (VOO2), thoracic temperature (Tth) and wing stroke frequency (n) were continuously measured at several ambient temperatures (Ta) during pre-flight warm-up and subsequent cooling in a small volume (30ml), open flow (240–300 ml min−1) respirometer. Heat production (HP) was tightly coupled to Tth and independent of Ta. The rate of change of HP (mWmin−1) was directly related to Ta. Total cost of warm-up was strongly, inversely related to Ta. The energetic cost of cooling was a small fraction of the total cost of warm-up. Increased energy expenditure occurred as a result of increases in both n and stroke work input. The latter increased from 0.58 to 1.1 mJ stroke− at low Tth (13–25°C) and was essentially constant at higher Tth (25–40°C). Wing stroke frequency increased continuously and linearly with Tth. In contrast to previous estimates based on heat exchange analyses, stroke work during warm-up was equivalent to values measured during free hovering flight. These data are consistent with the hypothesis that energy expenditure is maximized during warm-up.
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LAI, N. CHIN, JEFFREY B. GRAHAM, WILLIAM R. LOWELL, and RALPH SHABETAI. "Elevated Pericardial Pressure And Cardiac Output In The Leopard Shark Triakis Semifasciata During Exercise: The Role Of The Pericardioperitoneal Canal." Journal of Experimental Biology 147, no. 1 (November 1, 1989): 263–77. http://dx.doi.org/10.1242/jeb.147.1.263.
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Changes in pericardial pressure, pericardial fluid volume, cardiac stroke volume and heart rate induced by swimming were monitored for Triakis semifasciata (Girard). Maximum pericardial pressure (Pmax, 0.07±0.03 kPa) in resting sharks was typically above ambient, whereas minimum pressure (Pmin, −0.08±0.03 kPa) was slightly subambient. During swimming, both Pmax (0.23±0.03 kPa) and Pmin (−0.02±0.03 kPa) became elevated, as did heart rate (51±2 to 55±2 beats min−1) and fractional cardiac stroke volume (0.49±0.03 to 0.65±0.04ml). After swimming, all variables fell, except fractional cardiac stroke volume. Estimates of total cardiac output from fractional cardiac stroke volume data during rest, exercise and recovery were 33.1, 56.2 and 60.4 ml kg ‘1 min’ 1, respectively. The occurrence of both elevated pericardial pressure and cardiac output during swimming argues against a primary role for pericardial-induced vis a fronte filling as the principal mechanism responsible for increasing cardiac output with exercise. Pericardial fluid loss via the pericardioperitoneal canal (PPC) occurs during swimming as a result of steady-state elevation of pericardial pressure, a series of transient high pericardial pressures, or both. Good general agreement seen for net pericardial fluid loss (0.6 ml kg−) and the net increase in cardiac stroke volume (0.45 ml kg−) during swimming establishes fluid displacement as a mechanism for increasing cardiac stroke volume and suggests that this is the primary function of the PPC.
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Fischer, Hanno, Harald Wolf, and Ansgar Büschges. "The locust tegula: kinematic parameters and activity pattern during the wing stroke." Journal of Experimental Biology 205, no. 11 (June 1, 2002): 1531–45. http://dx.doi.org/10.1242/jeb.205.11.1531.
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SUMMARY The tegula is a complex, knob-shaped sense organ associated with the base of the locust wing. Despite a detailed knowledge of its role in flight motor control, little is known about the relationship between the stroke parameters of the wing, movement of the tegula organ and the pattern of tegula activity. In this study, therefore, the kinematic parameters of the fore- and hindwings were investigated with respect to the tegula activity pattern during tethered flight. The following results were obtained. (i) The tegula moves through a complex three-dimensional trajectory during the wing stroke, involving inclination and rotation about its longitudinal axis. (ii) The kinematic parameters of tegula movement are phase-locked to the wing stroke and vary in conjunction with wing stroke parameters such as amplitude and cycle period.(iii) In accordance with these phase-locked kinematics, both the onset of tegula activity with respect to the downstroke (latency) and the discharge of the organ (burst duration and amplitude) vary in conjunction with downstroke movement and cycle period, resulting in an (almost) constant phase of tegula activation during the stroke cycle. (iv) The pattern of tegula activity during flight is largely independent of stroke amplitude. (v) The latency, burst duration and amplitude of tegula activity are strongly related to the angular velocity of the wing during the downstroke, with latency reaching a steady minimum value at higher angular velocities. The data suggest that the tegula encodes the timing and velocity of the downstroke and that it may be involved in the control of the stroke's angular velocity.
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Walker, J., and M. Westneat. "Labriform propulsion in fishes: kinematics of flapping aquatic flight in the bird wrasse Gomphosus varius (Labridae)." Journal of Experimental Biology 200, no. 11 (January 1, 1997): 1549–69. http://dx.doi.org/10.1242/jeb.200.11.1549.
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Labriform, or pectoral fin, propulsion is the primary swimming mode for many fishes, even at high relative speeds. Although kinematic data are critical for evaluating hydrodynamic models of propulsion, these data are largely lacking for labriform swimmers, especially for species that employ an exclusively labriform mode across a broad range of speeds. We present data on pectoral fin locomotion in Gomphosus varius (Labridae), a tropical coral reef fish that uses a lift-based mechanism to fly under water at sustained speeds of 1­6 total body lengths s-1 (TL s-1). Lateral- and dorsal-view video images of three fish swimming in a flow tank at 1­4 TL s-1 were recorded at 60 Hz. From the two views, we reconstructed the three-dimensional motion of the center of mass, the fin tip and two fin chords for multiple fin beats of each fish at each of four speeds. In G. varius, the fin oscillates largely up and down: the stroke plane is tilted by approximately 20 ° from the vertical. Both frequency and the area swept by the pectoral fins increase with swimming speed. Interestingly, there are individual differences in how this area increases. Relative to the fish, the fin tip in lateral view moves along the path of a thin, inclined figure-of-eight. Relative to a stationary observer, the fin tip traces a sawtooth pattern, but the teeth are recumbent (indicating net backwards movement) only at the slowest speeds. Distal fin chords pitch nose downward during the downstroke and nose upward during the upstroke. Hydrodynamic angles of attack are largely positive during the downstroke and negative during the upstroke. The geometry of the fin and incident flow suggests that the fin is generating lift with large upward and small forward components during the downstroke. The negative incident angles during the upstroke suggest that the fin is generating largely thrust during the upstroke. In general, the large thrust is combined with a downward force during the upstroke, but the net backwards motion of the fin at slow speeds generates a small upward component during slow swimming. Both the alternating sign of the hydrodynamic angle of attack and the observed reduced frequencies suggest that unsteady effects are important in G. varius aquatic flight, especially at low speeds. This study provides a framework for the comparison of aquatic flight by fishes with aerial flight by birds, bats and insects.
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Barlow, D., M. A. Sleigh, and R. J. White. "WATER FLOWS AROUND THE COMB PLATES OF THE CTENOPHORE PLEUROBRACHIA PLOTTED BY COMPUTER: A MODEL SYSTEM FOR STUDYING PROPULSION BY ANTIPLECTIC METACHRONISM." Journal of Experimental Biology 177, no. 1 (April 1, 1993): 113–28. http://dx.doi.org/10.1242/jeb.177.1.113.
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Patterns of water flow around steadily beating comb plates of Pleurobrachia pileus were tracked using suspended plastic beads. The positions of the beads and the comb plates in the plane of the central longitudinal axis of the comb row were digitised from high-speed cine films covering several beat cycles. All of the data from each sequence were combined using a computer program which integrated them into a standard cycle, and the resulting data were plotted by a second computer program to produce charts for different stages in the beat cycle showing the flow velocity at a grid of points. On these charts, contour maps were drawn to indicate the speed and direction of the water flow. Water is drawn towards each comb row from ahead and from the sides and accelerates strongly backwards in a fairly narrow stream which joins those from the other seven comb rows at the rear of the animal. At a beat frequency of 10 Hz the comb plates move with a tip speed of up to 70 mm s-1 in their effective stroke; they have an estimated Reynolds number of 9 in this stroke. Changes in inter- plate volume between adjacent antiplectically coordinated plates are very important in propulsion, particularly near the end of the effective stroke when pairs of adjacent plates close together and cause the high-speed water from around the ciliary tips to be shed into the overlying stream as a series of jets at speeds of 50 mm s-1 or more. The antiplectic coordination of the comb plates makes a major contribution to the efficiency of propulsion.
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Blank, Jason M., Jeffery M. Morrissette, Peter S. Davie, and Barbara A. Block. "Effects of temperature, epinephrine and Ca2+ on the hearts of yellowfin tuna (Thunnus albacares)." Journal of Experimental Biology 205, no. 13 (July 1, 2002): 1881–88. http://dx.doi.org/10.1242/jeb.205.13.1881.
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SUMMARYTuna are endothermic fish with high metabolic rates, cardiac outputs and aerobic capacities. While tuna warm their skeletal muscle, viscera, brain and eyes, their hearts remain near ambient temperature, raising the possibility that cardiac performance may limit their thermal niches. We used an in situ perfused heart preparation to investigate the effects of acute temperature change and the effects of epinephrine and extracellular Ca2+ on cardiac function in yellowfin tuna (Thunnus albacares). Heart rate showed a strong temperature-dependence, ranging from 20 beats min-1 at 10 °C to 109 beats min-1 at 25 °C. Maximal stroke volume showed an inverse temperature-dependence,ranging from 1.4 ml kg-1 at 15 °C to 0.9 ml kg-1 at 25 °C. Maximal cardiac outputs were 27 ml kg-1 min-1at 10 °C and 98 ml kg-1 min-1 at 25 °C. There were no significant effects of perfusate epinephrine concentrations between 1 and 100 nmoll-1 at 20 °C. Increasing extracellular Ca2+ concentration from 1.84 to 7.36 mmoll-1 at 20°C produced significant increases in maximal stroke volume, cardiac output and myocardial power output. These data demonstrate that changes in heart rate and stroke volume are involved in maintaining cardiac output during temperature changes in tuna and support the hypothesis that cardiac performance may limit the thermal niches of yellowfin tuna.
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Sato, M., and A. Azuma. "The flight performance of a damselfly Ceriagrion melanurum Selys." Journal of Experimental Biology 200, no. 12 (January 1, 1997): 1765–79. http://dx.doi.org/10.1242/jeb.200.12.1765.
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The local circulation method was applied to the free forward flight of the damselfly Ceriagrion melanurum Selys. The kinematic data used in the calculations were obtained by analyzing video-taped images of damselflies in free flight in a transparent container. The inclination of the stroke plane was smaller and the flapping amplitude was larger than those of dragonflies reported in other studies on odonate flight. However, the phase shift between the fore- and hindwings agreed with none of the previously reported patterns for damselflies: the forewings lead the hindwings by approximately a quarter-period. The calculated forces were within the expected range of error. The muscle-mass-specific power was between 40 and 80 W kg-1. The vorticity distribution of trailing and shed vortices in the wake was also analyzed. Strong trailing vortices were observed at the wing tips, whereas shed vortices were concentrated near the wing root as the stroke switched direction.
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Wells, D. J. "MUSCLE PERFORMANCE IN HOVERING HUMMINGBIRDS." Journal of Experimental Biology 178, no. 1 (May 1, 1993): 39–57. http://dx.doi.org/10.1242/jeb.178.1.39.
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The flight energetics of hovering hummingbirds was examined by simultaneous collection of metabolic and kinematic data followed by a morphometric analysis of wing characteristics. These data were then used for an aerodynamic analysis of the power output required to generate sufficient lift; this, together with the metabolic power input, allowed an estimate of the flight efficiency. The use of two closely related species demonstrated common design features despite a marked difference in wing loading. Considerations of the inertial power costs strongly suggest that hummingbirds are able to store kinetic energy elastically during deceleration of the wing stroke. This analysis predicts that hummingbirds hover with a muscle power output close to 100–120 W kg-1 at 9–11 % mechanochemical efficiency.
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Mogami, Y., S. Sekiguchi, and S. A. Baba. "BEATING OF CILIA OF SEA URCHIN EMBRYOS: A CRITICAL COMPARISON OF THE NORMAL AND REVERSED BEATING OF CILIA OF ISOLATED CELLS." Journal of Experimental Biology 175, no. 1 (February 1, 1993): 251–66. http://dx.doi.org/10.1242/jeb.175.1.251.
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Two different types of ciliary beating, normal and reversed, were analyzed on the same cilia on cells isolated from echinoplutei. Bends on the cilium in reversed beating were observed to increase in curvature during propagation in the effective stroke of the beat, whereas in normal beating, bends propagate with a constant curvature in both effective and recovery strokes. The proximal region of the cilium showed an almost identical oscillation of shear angle in both normal and reversed beating with respect to the time normalized to the average beat period, which was determined by the rotational movement of the cell body. In reversed beating, a common temporal profile generated at the proximal region was preserved in the oscillation over the length of the cilium. The local oscillations in normal beating, however, changed in temporal profile as seen from base to tip. The conversion of the temporal oscillatory profile from normal to reversed beating occurred in association with changes in the centre of the oscillation (static bias), whose difference increased with the distance from the base. The data indicate that the changes in bending pattern between normal and reversed beating of sea urchin embryo cilia are not due to changes in the initiation of the oscillation at the base, but largely to temporal and static changes in the pattern of propagation of the oscillatory activity.
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Penney, Chantelle M., Gordon W. Nash, and A. Kurt Gamperl. "Cardiorespiratory responses of seawater-acclimated adult Arctic char (Salvelinus alpinus) and Atlantic salmon (Salmo salar) to an acute temperature increase." Canadian Journal of Fisheries and Aquatic Sciences 71, no. 7 (July 2014): 1096–105. http://dx.doi.org/10.1139/cjfas-2013-0569.
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In this first study examining the thermal tolerance of adult Arctic char (Salvelinus alpinus) acclimated to seawater, we measured their critical thermal maximum (CTMax) and several cardiorespiratory parameters (oxygen consumption (MO2), heart rate (fH), stroke volume (SV), cardiac output (Q), ventilatory frequency (VF), opercular pressure (PO), and ventilatory effort (VE)) when exposed to a temperature increase of 2 °C·h−1. Further, we directly compared these results with those obtained for the eurythermal Atlantic salmon (Salmo salar) under identical conditions. There was no significant difference in cardiorespiratory values between the two species at their acclimation temperature (9.5–10 °C). In contrast, the slope of the MO2–temperature relationship was lower (by 27%) in the char as compared with that in the salmon, and the char had significantly lower values for maximum fH (by 13%), maximum MO2 (by 35%), absolute metabolic scope (by 39%), and CTMax (approximately 23 versus 26.5 °C, respectively). Although not a focus of the study, preliminary data suggest that interspecific differences in mitochondrial respiration (oxidative phosphorylation), and its temperature sensitivity, may partially explain the difference in thermal tolerance between the two species. These results provide considerable insights into why Atlantic salmon are displacing Arctic char in the current era of accelerated climate change.
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Bishop, C., and P. Butler. "Physiological modelling of oxygen consumption in birds during flight." Journal of Experimental Biology 198, no. 10 (October 1, 1995): 2153–63. http://dx.doi.org/10.1242/jeb.198.10.2153.
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This study combines data on changes in cardiovascular variables with body mass (Mb) and with exercise intensity to model the oxygen supply available to birds during flight. Its main purpose is to provide a framework for identifying the factors involved in limiting aerobic power input to birds during flight and to suggest which cardiovascular variables are the most likely to have been influenced by natural selection when considering both allometric and adaptive variation. It is argued that natural selection has acted on heart rate (fh) and cardiac stroke volume (Vs), so that the difference in the arteriovenous oxygen content (CaO2-Cv¯O2) in birds, both at rest and during flight, is independent of Mb. Therefore, the Mb exponent for oxygen consumption (V(dot)O2) during flight can be estimated from measurements of heart rate and stroke volume. Stroke volume is likely to be directly proportional to heart mass (Mh) and, using empirical data, values for the Mb coefficients and exponents of various cardiovascular variables are estimated. It is concluded that, as found for mammals, fh is the main adaptive variable when considering allometric variation, although Mh also shows a slight scaling effect. Relative Mh is likely to be the most important when considering adaptive specialisations. The Fick equation may be represented as: (V(dot)O2)Mbz = (fh)Mbw x (Vs)Mbx x (CaO2 - Cv¯O2)Mby , where w, x, y, z are the body mass exponents for each variable and the terms in parentheses represent the Mb coefficients. Utilising this formula and data from the literature, the scaling of minimum V(dot)O2 during flight for bird species with a 'high aerobic capacity' (excluding hummingbirds) is calculated to be: 166Mb0.77±0.09 = 574Mb-0.19±0.02 x 3.48Mb0.96±0.02 x 0.083Mb0.00±0.05 , and for hummingbirds (considered separately owing to their unique wing kinematics) it is: 314Mb0.90±0.22 = 617Mb-0.10±0.06 x 6.13Mb1.00±0.11 x 0.083Mb0.00±0.05 . These results are largely dependent on the cardiovascular values obtained from pigeons flying near to the minimum power speed of 10 m s-1, but would appear to provide realistic values. Both the measured and the estimated V(dot)O2 for hummingbirds appear to scale with a larger Mb exponent than that for all other birds, and it is suggested that this is as a result of the larger Mb exponent for flight muscle mass as the larger species of hummingbirds try to maintain hovering performance. It is proposed that estimated V(dot)O2 for birds during flight, which is based on Mh in combination with estimates of fh and CaO2-Cv¯O2, gives an indirect measure of relative aerobic power input and, when corrected for the estimated scaling influences of the mechano-chemical conversion efficiency and lift generation with respect to Mb, may be a useful indicator of the relative capacity of the muscle to sustain power output and lift production during flight.
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Videler, J., and P. Kamermans. "Differences between upstroke and downstroke in swimming dolphins." Journal of Experimental Biology 119, no. 1 (November 1, 1985): 265–74. http://dx.doi.org/10.1242/jeb.119.1.265.
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Steady swimming movements of dolphins were recorded in a search for direct evidence of asymmetry between upstrokes and downstrokes. Kinematic swimming and gliding data from frame-by-frame analysis of cine pictures taken at constant frame rates with a camera in a fixed position are presented. We estimated the propulsive forces generated by the tail blade with a simple hydrodynamic model. Dolphins accelerate during the downstroke and decelerate during the upstroke: the net hydrodynamic force in the animal is always positive during the downstroke and negative during the upstroke. Both parts of the stroke cycle are equally long. The propulsive forces of downstrokes are on average larger than the forces of the upstrokes. Occasionally the average forces within an upstroke are greater than within a downstroke of the same sequence. Our data suggest that the drag on the body during the upstroke exceeds the drag in the course of the downstroke. The specific swimming speed or stride length of dolphins swimming at low speeds is about 0.9 body lengths per tail beat.
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Jones, D. R., R. W. Brill, and P. G. Bushnell. "VENTRICULAR AND ARTERIAL DYNAMICS OF ANAESTHETISED AND SWIMMING TUNA." Journal of Experimental Biology 182, no. 1 (September 1, 1993): 97–112. http://dx.doi.org/10.1242/jeb.182.1.97.
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Cardiovascular dynamics of tuna have been investigated by recording blood pressures and flows in the central circulation of both anaesthetised and swimming individuals. In anaesthetised fish (N=5), heart rate averaged 112+/−21 beats min-1 (mean +/− s.e.) and stroke volume was 0.67+/−0.24 ml kg-1 when normoxic water flowed over the gills. Ventricular diastolic pressure was zero until atrial contraction filled the ventricle. Ventral aortic pressures were high (mean 12.08+/−1.15 kPa), and blood flow was continuous in the ventral aorta throughout diastole. Dorsal aortic pressure (mean 6.3+/−1.28 kPa; N=4) and flow were both pulsatile. Pressure pulsatility (pulse pressure as a proportion of mean pressure) was about one-quarter of flow pulsatility, indicating considerable compliance in the dorsal aortic circulation. Total peripheral resistance averaged 0.17+/−0.4 kPa ml-1 kg-1 min-1 of which gill resistance averaged 48+/−15 % (N=4). For the ventral aorta, impedance modulus fell markedly from the mean value and then declined more gradually towards zero with increasing harmonic frequencies. Impedance phase was negative (−0.8 to −1.1 rad) meaning that flow leads pressure at all harmonics. In swimming yellowfin tuna (N=5), heart rate averaged 108.8+/−12.1 beats min-1 and mean ventral and dorsal aortic pressures were 11.6+/−0.5 and 6.8+/−1.2 kPa, respectively, so gill resistance was 42 % of total peripheral resistance. Average stroke volume in three swimming kawakawa was 0.54+/−0.2 ml kg- 1 at a mean heart rate of 128+/−48 beats min-1. Data from swimming fish were within the range obtained from anaesthetised tuna. A simple model of the fish circulation consisting of two sets of compliant and resistive elements coupled in series (a second-order RC network) gave reasonable predictions of arterial pressure-flow relationships. Hence, we conclude that a ‘Windkessel’ dominates central cardiovascular dynamics of tuna despite heart rates and blood pressures that fall in the mammalian range.
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Herrel, A., P. Aerts, and F. De Vree. "Cranial kinesis in geckoes: functional implications." Journal of Experimental Biology 203, no. 9 (May 1, 2000): 1415–23. http://dx.doi.org/10.1242/jeb.203.9.1415.
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Although it is generally assumed that cranial kinesis is a plesiomorphic characteristic in squamates, experimental data tend to contradict this hypothesis. In particular, coupled kinesis (i.e. streptostyly and mesokinesis) presumably arose independently in only a limited number of highly specialised groups. In this study, we investigated cranial kinesis in one of the most specialised of these groups: geckoes. On the basis of cineradiographic and electromyographic data, the fast opening and the slow closing/power stroke phases were modelled to elucidate possible functions of the observed kinesis. The results of these analyses show that the retraction of the muzzle unit during crushing is a self-reinforcing system that increases bite force and reduces the joint forces; the active protraction of the kinetic system during jaw opening, in contrast, enhances opening speed through the coupling of the intracranial units. It can be argued that cranial kinesis in geckoes is probably not an adaptive trait as such but, instead, a consequence of the ‘Bauplan’ of the cranial system in these animals. Presumably as a result of constructional constraints on the size of the jaw musculature and eyes, the supratemporal and postorbital bars were lost, which resulted in enormous mobility in the skull. To counteract the potential negative factors associated with this (decrease in bite force, skull damage), the kinetic system may have become coupled, and thus functional.
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Herrel, A., J. Cleuren, and F. Vree. "Quantitative analysis of jaw and hyolingual muscle activity during feeding in the lizard Agama stellio." Journal of Experimental Biology 200, no. 1 (January 1, 1997): 101–15. http://dx.doi.org/10.1242/jeb.200.1.101.
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The activity of jaw and hyolingual muscles during the entire feeding sequence is examined in the lizard Agama stellio, with special focus on the intraoral transport and swallowing stages. Correlation of electromyography (EMG) data with kinematics shows that the kinematic phases (slow opening, SO; fast opening, FO; fast closing, FC; slow closing/power stroke, SC/PS) are characterised by distinct activities in the jaw and hyolingual muscles. The SO phase is clearly the result of tongue protraction (upon protraction, the tongue is pulled against the prey and consequently the lower jaw is pushed down), whereas the FO phase is caused by activity in the jaw opener and dorsal cervical muscles. Both the FC and SC/PS phases are characterised by pronounced activity in the jaw adductor muscles. Tongue retraction is produced by activity in the hyoid and tongue retractor muscles. A quantitative analysis of time-related EMG data shows that, in accordance with the kinematic analyses, three different stages can be recognised as components of the feeding cycle: prey capture, intraoral transport and swallowing. However, analysis of intensity-related data allowed a fourth stage, crushing, to be detected. Whereas there are indications that prey capture, intraoral transport and swallowing are controlled by different motor patterns, the differences between crushing and transport are likely to be caused by feedback mechanisms. Our results show the importance of including intensity-related data in quantitative analyses of EMG recordings in order to discriminate between feeding stages. Additionally, it is shown that both the jaw and the hyolingual muscles play crucial roles during feeding. During all stages, movements of the hyolingual apparatus are an essential part of the feeding cycle. Thus, when examining lizard feeding mechanisms, the activity patterns of the hyolingual muscles should not be neglected.
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Webber, DM, RG Boutilier, and SR Kerr. "Cardiac output as a predictor of metabolic rate in cod gadus morhua." Journal of Experimental Biology 201, no. 19 (October 1, 1998): 2779–89. http://dx.doi.org/10.1242/jeb.201.19.2779.
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Adult Atlantic cod (2 kg Gadus morhua) were fitted with Doppler ultrasonic flow-probes to measure ventral aortic outflow (i.e. cardiac output). The probes remained patent for upwards of 3 months, during which time detailed relationships between cardiac output (), heart rate (fh) and rate of oxygen consumption (O2) were determined as a function of swimming speed and temperature (5 degreesC and 10 degreesC). The rate of oxygen consumption increased linearly with and exponentially with swimming speed. A very good correlation was observed between O2 and (r2=0.86) compared with the correlation between O2 and fh (r2=0.50 for all 10 degreesC data and r2=0.86 for all 5 degreesC data). However, the O2 versus fh correlation gradually improved over approximately 1 week after surgery (r2=0.86). The relationship between O2 and was independent of temperature, while the relationship between O2 and fh changed with temperature. Hence, calculating O2 from is simpler and does not require that temperature be recorded simultaneously. Variations in cardiac output were determined more by changes in stroke volume (Vs) than by fh; therefore, fh was a less reliable predictor of metabolic rate than was . Given that can be used to estimate O2 so faithfully, the advent of a cardiac output telemeter would enable robust estimates to be made of the activity metabolism of free-ranging fish in nature, thereby strengthening one of the weakest links in the bioenergetic models of fisheries biology.
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Territo, P. R., and W. W. Burggren. "Cardio-respiratory ontogeny during chronic carbon monoxide exposure in the clawed frog Xenopus laevis." Journal of Experimental Biology 201, no. 9 (May 1, 1998): 1461–72. http://dx.doi.org/10.1242/jeb.201.9.1461.
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The present study investigates the ontogeny of cardio-respiratory physiology in Xenopus laevis where O2 transport is obstructed. Animals were raised from eggs (NF stage 1) to metamorphic climax (NF stage 63), while maintained either in air or in chronic 2 kPa CO, which functionally ablates O2 transport by hemoglobin (Hb). Whole-animal rate of oxygen consumption (.MO2), whole-body lactate concentration, individual mass, heart rate (fh) and stroke volume (Vs) were measured. Additionally, cardiac output (.Q) and the ratio of the rate of oxygen consumption to the total rate at which oxygen is transported in the blood (.MO2/.QO2) were calculated to determine limitations imparted when O2 transport is impaired. Our data on early development suggest that the onset of convective blood flow occurs prior to the absolute need for convection to supplement diffusive transport. Values for .MO2, whole-body lactate concentration, mass and fh did not differ significantly between controls and CO-exposed animals. However, CO-exposed animals showed a significant (P<0.05) increase in Vs, .MO2/.QO2 and .Q compared with controls. These results indicate that limiting blood O2 transport is not deleterious to metabolism and development as a whole and that convective oxygen transport via Hb is not essential for normal cardiovascular or respiratory function during larval development.
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Drucker, E., and G. Lauder. "Wake dynamics and fluid forces of turning maneuvers in sunfish." Journal of Experimental Biology 204, no. 3 (February 1, 2001): 431–42. http://dx.doi.org/10.1242/jeb.204.3.431.
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While experimental analyses of steady rectilinear locomotion in fishes are common, unsteady movement involving time-dependent variation in heading, speed and acceleration probably accounts for the greatest portion of the locomotor time budget. Turning maneuvers, in particular, are key elements of the unsteady locomotor repertoire of fishes and, by many species, are accomplished by generating asymmetrical forces with the pectoral fins. The development of such left-right asymmetries in force production is a critical and as yet unstudied aspect of aquatic locomotor dynamics. In this paper, we measure the fluid forces exerted by the left and right pectoral fins of bluegill sunfish (Lepomis macrochirus) during turning using digital particle image velocimetry (DPIV). DPIV allowed quantification of water velocity fields, and hence momentum, in the wake of the pectoral fins as sunfish executed turns; forces exerted during turning were compared with those generated by the immediately preceding fin beats during steady swimming. Sunfish generate the forces required for turning by modulating two variables: wake momentum and pectoral fin stroke timing. Fins on opposite sides of the fish play functionally distinct roles during turning maneuvers. The fin nearer the stimulus inducing the turn (i.e. the strong side fin) generates a laterally oriented vortex ring with a strong central jet whose associated lateral force is four times greater than that produced during steady swimming. Little posterior (thrust) force is generated by the strong-side fin, and this fin therefore acts to rotate the body away from the source of the stimulus. The contralateral (weak-side) fin generates a posteriorly oriented vortex ring with a thrust force nine times that produced by the fin during steady swimming. Minimal lateral force is exerted by the weak-side fin, and this fin therefore acts primarily to translate the body linearly away from the stimulus. Turning with the paired fins is not simply steady swimming performed unilaterally. Instead, turning involves asymmetrical fin movements and fluid forces that are distinct in both direction and magnitude from those used to swim forward at constant speed. These data reflect the plasticity of the teleost pectoral fin in performing a wide range of steady and unsteady locomotor tasks.
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Johansson, L. Christoffer, and Björn S. Wetterholm Aldrin. "Kinematics of diving Atlantic puffins (Fratercula arctica L.):evidence for an active upstroke." Journal of Experimental Biology 205, no. 3 (February 1, 2002): 371–78. http://dx.doi.org/10.1242/jeb.205.3.371.
Full textAbstract:
SUMMARY To examine the propulsion mechanism of diving Atlantic puffins (Fratercula arctica), their three-dimensional kinematics was investigated by digital analysis of sequential video images of dorsal and lateral views. During the dives of this wing-propelled bird, the wings are partly folded, with the handwings directed backwards. The wings go through an oscillating motion in which the joint between the radius-ulna and the hand bones leads the motion, with the wing tip following. There is a large rotary motion of the wings during the stroke, with the wings being pronated at the beginning of the downstroke and supinated at the end of the downstroke/beginning of the upstroke. Calculated instantaneous velocities and accelerations of the bodies of the birds show that, during the downstroke, the birds accelerate upwards and forwards. During the upstroke, the birds accelerate downwards and, in some sequences analysed, also forwards, but in most cases the birds decelerate. In all the upstrokes analysed, the forward/backward acceleration shows the same pattern, with a reduced deceleration or even a forward acceleration during ‘mid’ upstroke indicating the production of a forward force, thrust. Our results show that the Atlantic puffin can use an active upstroke during diving, in contradiction to previous data. Furthermore, we suggest that the partly folded wings of diving puffins might act as efficient aft-swept wingtips, reducing the induced drag and increasing the lift-to-drag ratio. A movie is available on-line.
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Fahlman, Andreas, Stefan Miedler, Luis Marti-Bonmati, Diana Ferrero Fernandez, Paola Muñoz Caballero, Julietta Arenarez, Julie Rocho-Levine, Todd Robeck, and Ashley Blawas. "Cardiorespiratory coupling in cetaceans; a physiological strategy to improve gas exchange?" Journal of Experimental Biology 223, no. 17 (July 17, 2020): jeb226365. http://dx.doi.org/10.1242/jeb.226365.
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ABSTRACTIn the current study we used transthoracic echocardiography to measure stroke volume (SV), heart rate (fH) and cardiac output (CO) in adult bottlenose dolphins (Tursiops truncatus), a male beluga whale calf [Delphinapterus leucas, body mass (Mb) range: 151–175 kg] and an adult female false killer whale (Pseudorca crassidens, estimated Mb: 500–550 kg) housed in managed care. We also recorded continuous electrocardiogram (ECG) in the beluga whale, bottlenose dolphin, false killer whale, killer whale (Orcinus orca) and pilot whale (Globicephala macrorhynchus) to evaluate cardiorespiratory coupling while breathing spontaneously under voluntary control. The results show that cetaceans have a strong respiratory sinus arrythmia (RSA), during which both fH and SV vary within the interbreath interval, making average values dependent on the breathing frequency (fR). The RSA-corrected fH was lower for all cetaceans compared with that of similarly sized terrestrial mammals breathing continuously. As compared with terrestrial mammals, the RSA-corrected SV and CO were either lower or the same for the dolphin and false killer whale, while both were elevated in the beluga whale. When plotting fR against fH for an inactive mammal, cetaceans had a greater cardiac response to changes in fR as compared with terrestrial mammals. We propose that these data indicate an important coupling between respiration and cardiac function that enhances gas exchange, and that this RSA is important to maximize gas exchange during surface intervals, similar to that reported in the elephant seal.
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Rosenberger, L. J., and M. W. Westneat. "Functional morphology of undulatory pectoral fin locomotion in the stingray taeniura lymma (Chondrichthyes: dasyatidae)." Journal of Experimental Biology 202, no. 24 (December 15, 1999): 3523–39. http://dx.doi.org/10.1242/jeb.202.24.3523.
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Rajiform locomotion is a unique swimming style found in the batoid fishes (skates and rays) in which thrust is generated by undulatory waves passing down the enlarged pectoral fins. We examined the kinematic patterns of fin motion and the motor patterns of pectoral fin muscles driving the locomotor system in the blue-spot stingray Taeniura lymma. Our goals in this study were to determine overall patterns of fin motion and motor control during undulatory locomotion, to discover how these patterns change with swimming velocity and to correlate muscle function with kinematics and pectoral morphology. Kinematic data were recorded from five individuals over a range of swimming speeds from 22 to 55 cm s(−)(1) (0.9-3.0 DL s(−)(1), where DL is body disc length). Electromyographic (EMG) data were recorded from three individuals over a range of velocities (1.2-3.0 DL s(−)(1)) at seven locations (four dorsal, three ventral) along the pectoral fin. As swimming velocity increases, fin-beat frequency, wavespeed and stride length increase, number of waves and reduced frequency decrease and fin amplitude remains constant. There is variability among individuals in frequency and amplitude at a given speed. An inverse relationship was found in which a high fin-beat frequency is associated with a low fin amplitude and a low fin-beat frequency is associated with a high fin amplitude. The motor pattern of undulatory locomotion is alternate firing activity in the dorsal and ventral muscles as the wave moves along the fin from anterior to posterior. Fin muscles are active along the entire length of the fin except at the lowest speeds. As swimming velocity and fin-beat frequency increase, the time of activation of posterior muscles becomes earlier relative to the onset of activity in the anterior dorsal muscles. The duration of muscle activity is longer in the ventral muscles than in the dorsal muscles, indicating that they play a central role in the power stroke of the fin-beat cycle. The anterior muscles (dorsal and ventral) are active for a relatively longer part of the stride cycle than the posterior muscles. Both the anterior position and the large duty factor of the anterior muscles reflect the role of these muscles in initial wave generation. Synchronous recordings of kinematic data with EMG data reveal that the anterior dorsal and middle ventral muscles do mostly positive work, whereas the dorsal and ventral posterior muscles do negative work at most swimming speeds.
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GLEESON, TODD T. "Patterns of Metabolic Recovery from Exercise in Amphibians and Reptiles." Journal of Experimental Biology 160, no. 1 (October 1, 1991): 187–207. http://dx.doi.org/10.1242/jeb.160.1.187.
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The physiological responses of amphibians and reptiles undergoing vigorous exercise are qualitatively similar to those of other vertebrates. Oxygen consumption increases rapidly to rates that are three- to 10-fold the rates at rest. The aerobic response to graded exercise in locomoting reptiles and amphibians is for the most part linear. Oxygen transport by the cardiovascular system during exercise is accomplished by factorial increases in heart rate and oxygen extraction from arterial blood in a fashion similar to that in mammals. Increments in stroke volume during exercise are small or in some cases negative. The influence of temperature or of intracardiac shunting on the cardiovascular function of active amphibians and reptiles is poorly understood. These aerobic responses to exercise are accompanied by robust anaerobic contributions to energy metabolism, resulting in significant lactate accumulation and glycogen depletion. The rate of lactate accumulation during exercise is generally greater in reptiles than in amphibians, but in all cases is so rapid that the only significant substrate source to support anaerobic energy production is muscle glycogen. Vigorous behavior in these animals is therefore limited to some degree by the maintenance and replenishment of muscle glycogen stores. Whereas data from rats and dogs suggest that most lactate is oxidized to CO2 following exercise, amphibians and reptiles appear to use lactate as a substrate for immediate muscle glycogen replenishment. Data from a variety of amphibians and lizards demonstrate that lactate removal following activity and glycogen replenishment are stoichiometrically and temporally related. Studies employing isotopically labelled compounds in intact frogs and lizards indicate that most lactate is resynthesized to glycogen during recovery. In vivo studies suggest skeletal muscle as the site for glycogenesis from lactate, and in vitro studies from many laboratories demonstrate a gluconeogenic capacity in skeletal muscle of lizards, frogs and salamanders. The liver appears to play no significant role in recovery metabolism in any of these classes. Data from lizard muscle suggest that oxidative fiber types have the most significant gluconeogenic capacity, and that the process may be stimulated by the hormonal milieu that exists following exercise. Whereas the recovery metabolism of many mammals seems to facilitate the rapid return of acid-base balance via lactate oxidation, the strategy of lactate removal employed by amphibians and reptiles provides for a mechanism of immediate muscle glycogen replenishment and consequently a reestablished capacity for subsequent activity.
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Butler, Patrick J., Peter B. Frappell, Tobias Wang, and Martin Wikelski. "The relationship between heart rate and rate of oxygen consumption in Galapagos marine iguanas (Amblyrhynchus cristatus) at two different temperatures." Journal of Experimental Biology 205, no. 13 (July 1, 2002): 1917–24. http://dx.doi.org/10.1242/jeb.205.13.1917.
Full textAbstract:
SUMMARY To enable the use of heart rate (fH) for estimating field metabolic rate (FMR) in free-ranging Galapagos marine iguanas Amblyrhynchus cristatus, we determined the relationships between fH and mass-specific rate of oxygen consumption(sV̇O2) in seven iguanas before and during exercise on a treadmill and during the post-exercise period. The experiments were conducted at 27 and 35°C, which are the temperatures that represent the lowest and highest average body temperatures of these animals in the field during summer. There were linear and significant relationships between fH and sV̇O2 at both temperatures (r2=0.86 and 0.91 at 27°C and 36°C,respectively). The slopes of the two regression lines did not differ, but there were significant differences in their intercepts. Thus, while heart rate can be used to predict FMR, the effects of temperature on the intercept of the regression must be taken into account when converting fH to sV̇O2. On the basis of our data, this can be achieved by applying the following formula: \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[\mathrm{s}{\dot{V}}_{\mathrm{o}_{2}}=0.0113f\mathrm{H}-0.2983\mathrm{Q}_{10}^{\frac{(T_{\mathrm{b}}-27)}{10}}.\] \end{document}The increase in sV̇O2 with elevated body temperature results from an increase in fH, with no significant change in mass-specific oxygen pulse (sO2 pulse;cardiac stroke volume times the difference in oxygen content between arterial and mixed venous blood). However, during exercise at both temperatures,increases in fH are insufficient to provide all of the additional O2 required and there are also significant increases in the sO2 pulses. This creates the situation whereby the same fH at the two temperatures can represent different values of sV̇O2.
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Jürgens, K. D., R. Fons, T. Peters, and S. Sender. "Heart and respiratory rates and their significance for convective oxygen transport rates in the smallest mammal, the Etruscan shrew Suncus etruscus." Journal of Experimental Biology 199, no. 12 (December 1, 1996): 2579–84. http://dx.doi.org/10.1242/jeb.199.12.2579.
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Heart and respiratory rates of the smallest mammal (mean adult body mass 2g), the Etruscan shrew Suncus etruscus, were determined at rest and under stress conditions. Heart rate was obtained from electrocardiograms (ECGs), recorded via foot electrodes. The mean +/- S.D. heart rate of resting animals (ambient temperature 22 degrees C) was 835 +/- 107 min-1, the mean maximal rate amounted to 1093 +/- 235 min-1. The highest single value recorded was 1511 min-1, which is the highest heart rate reported so far for an endotherm. The respiratory rate was also obtained from ECG recordings, which showed the electrical activity of the breathing muscles during inhalation, and additionally by recording the movements of the thoracic wall with a laser autofocus system. The mean resting respiratory rate was 661 +/- 93 min-1, the mean maximal rate was 758 +/- 109 min-1 and the highest single value recorded was 894 min-1. At 22 degrees C, the specific oxygen consumption rate is 67 times higher in resting S. etruscus than in resting humans. Under these conditions, the respiratory rate of the shrew is 47 times higher but the heart rate only 12 times higher than in man. Therefore, to achieve an adequate circulatory oxygen transport rate, the product of relative stroke volume and arterio-venous O2 difference has to be 5.6 times higher in the shrew than in man, whereas for an appropriate ventilatory oxygen transport rate the product of relative tidal volume and oxygen extraction has to be only 1.4 times higher in this small insectivore than in man. The maximal possible oxygen transport rates of the ventilatory and the circulatory system have been estimated and compared with the diffusional transport capacity of the lung. These rates amount to approximately 1000 ml O2 kg-1 min-1. According to our results and data in the literature, an aerobic scope of 7-10 seems to be realistic for the Etruscan shrew.
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LAUDER, G. V., and T. PRENDERGAST. "KINEMATICS OF AQUATIC PREY CAPTURE IN THE SNAPPING TURTLE CHELYDRA SERPENTINA." Journal of Experimental Biology 164, no. 1 (March 1, 1992): 55–78. http://dx.doi.org/10.1242/jeb.164.1.55.
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The kinematics of feeding on two prey types is studied quantitatively in the common snapping turtle, Chelydra serpentina, to provide a description of prey capture mechanisms and to determine whether kinematic patterns can be altered in response to prey that vary in escape capability. High-speed video recordings of prey capture (200 fields s−1) provide data for field-by-field analysis of 12 kinematic variables characterizing head and neck movement. Feedings on fish were accomplished in 78ms, with peak head extension velocities of 152.5cms−1. Worm feedings lasted 98ms with maximum head extension velocities of 54cms−1. Both univariate and multivariate statistical analyses demonstrate significant differences in kinematic patterns between fish and earthworm feedings: Chelydra serpentina possesses the ability to modulate its kinematic pattern depending on the prey. The pattern of bone movement during the fast opening phase of the gape cycle is similar to that found in ray-finned fishes, lungfishes and aquatic salamanders. However, movements of the cranium and lower jaw during the closing phase are markedly different. Our data show Chelydra to be predominantly a ram-feeder, with any intraoral negative pressures generated during the strike having a negligible effect on the prey, which remains largely stationary relative to a fixed background. Hyoid and esophageal expansion during the closing phase may function to allow a unidirectional flow of water and prey into the mouth until the gape closes and to delay reverse flow until the prey has been trapped inside the mouth. The independent evolutionary acquisition of aquatic feeding in fishes and turtles reveals some kinematic similarities that may be the result of hydrodynamic constraints on aquatic prey capture systems, as well as kinematic differences that result from the fundamentally different morphological design of the prey capture apparatus.
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Bernier, N. J., and S. F. Perry. "Cardiovascular effects of angiotensin-II-mediated adrenaline release in rainbow trout Oncorhynchus mykiss." Journal of Experimental Biology 202, no. 1 (January 1, 1999): 55–66. http://dx.doi.org/10.1242/jeb.202.1.55.
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To determine the contribution of plasma catecholamines to the cardiovascular effects of elevated levels of angiotensin II (Ang II) in trout, this study investigated (1) the stimulatory effects of [Asn1-Val5]-Ang II on plasma catecholamine levels, (2) the cardiovascular effects of Ang II with and without alpha-adrenoceptor blockade and (3) the relationship between plasma adrenaline concentrations and their cardiovascular effects. Bolus intravascular injections of Ang II (25–1200 pmol kg-1) elicited dose-dependent (between 75 and 1200 pmol kg-1) increases in plasma adrenaline levels; mean plasma noradrenaline levels only increased in response to a dose of 1200 pmol kg-1. Ang-II-elicited increases in plasma adrenaline levels ranged from 3.3+/−0.3 nmol l-1 for 75 pmol kg-1 Ang II to 125.1+/−40.0 nmol l-1 for 1200 pmol kg-1 Ang II. Injections of Ang II (25–1200 pmol kg-1) also elicited dose-dependent increases in dorsal aortic pressure (PDA), systemic resistance (RS), cardiac output (Q) and stroke volume (Vs). In fish first treated with the alpha -adrenoceptor blocker phenoxybenzamine, Ang II injections elicited a decrease in q_dot and Vs, and the increases in PDA and RS following administration of the 600 and 1200 pmol kg-1 Ang II doses were significantly reduced. Bolus injections of adrenaline (1.8×10(−10) to 1.4×10(−8) mol kg-1) elicited dose-dependent increases in PDA at a plasma adrenaline concentration of 16.5 nmol l-1 and in RS at a plasma adrenaline concentration of 50.5 nmol l-1. Adrenaline injections also elicited increases in Q and Vs at plasma adrenaline concentrations of 50.5 nmol l-1; however, higher plasma adrenaline concentrations were not associated with further increases in either Q or Vs. These results demonstrate that, in vivo, Ang II can act as a potent non-cholinergic secretagogue of humoral adrenaline in trout and that some of the cardiovascular effects of exogenous Ang II can be attributed to increased levels of plasma adrenaline. Our data also indicate that the cardiovascular effects of Ang-II-mediated humoral catecholamines are recruited in a dose-dependent manner and, as such, may require an acute stimulation of the renin-angiotensin system to contribute significantly to the pressor activity of endogenous angiotensins.
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Dickinson, M. H., and K. G. Gotz. "UNSTEADY AERODYNAMIC PERFORMANCE OF MODEL WINGS AT LOW REYNOLDS NUMBERS." Journal of Experimental Biology 174, no. 1 (January 1, 1993): 45–64. http://dx.doi.org/10.1242/jeb.174.1.45.
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The synthesis of a comprehensive theory of force production in insect flight is hindered in part by the lack of precise knowledge of unsteady forces produced by wings. Data are especially sparse in the intermediate Reynolds number regime (10<Re<1000) appropriate for the flight of small insects. This paper attempts to fill this deficit by quantifying the time-dependence of aerodynamic forces for a simple yet important motion, rapid acceleration from rest to a constant velocity at a fixed angle of attack. The study couples the measurement of lift and drag on a two-dimensional model with simultaneous flow visualization. The results of these experiments are summarized below. 1. At angles of attack below 13.5°, there was virtually no evidence of a delay in the generation of lift, in contrast to similar studies made at higher Reynolds numbers. 2. At angles of attack above 13.5°, impulsive movement resulted in the production of a leading edge vortex that stayed attached to the wing for the first 2 chord lengths of travel, resulting in an 80 % increase in lift compared to the performance measured 5 chord lengths later. It is argued that this increase is due to the process of detached vortex lift, analogous to the method of force production in delta-wing aircraft. 3. As the initial leading edge vortex is shed from the wing, a second vortex of opposite vorticity develops from the trailing edge of the wing, correlating with a decrease in lift production. This pattern of alternating leading and trailing edge vortices generates a von Karman street, which is stable for at least 7.5 chord lengths of travel. 4. Throughout the first 7.5 chords of travel the model wing exhibits a broad lift plateau at angles of attack up to 54°, which is not significantly altered by the addition of wing camber or surface projections. 5. Taken together, these results indicate how the unsteady process of vortex generation at large angles of attack might contribute to the production of aerodynamic forces in insect flight. Because the fly wing typically moves only 2–4 chord lengths each half-stroke, the complex dynamic behavior of impulsively started wing profiles is more appropriate for models of insect flight than are steady-state approximations.
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Wachter, B., and B. Mcmahon. "Haemolymph flow distribution, cardiac performance and ventilation during moderate walking activity in Cancer magister (Dana) (Decapoda, Crustacea)." Journal of Experimental Biology 199, no. 3 (March 1, 1996): 627–33. http://dx.doi.org/10.1242/jeb.199.3.627.
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Adult male Cancer magister (Dana) were equipped with pulsed-Doppler flowmeters and pressure transducers for simultaneous measurement of heart and ventilation frequencies, haemolymph flow through each of the major arterial systems and cardiac output and for calculation of stroke volume. Each variable was measured at rest and during two consecutive periods of moderate treadmill walking activity and recovery. During activity, haemolymph flow through the sternal and anterolateral arteries increased, while flow through the hepatic arterial system decreased. This resulted in a redistribution of haemolymph flow in which a proportion of cardiac output was shifted from the anterior, posterior and hepatic arterial systems to the sternal arterial system. The relative proportion of the cardiac output flowing through the anterolateral artery remained constant. This indicated that oxygen supply was shifted away from the digestive system to the muscles of the walking legs and the respiratory system. Cardiac output, heart rate and stroke volume all increased in response to activity. The increase in cardiac output is the result of a large increase in stroke volume and a small increase in heart rate. A doubling of ventilation rate also occurred during activity. Both the circulatory and ventilatory systems were restored to pre-activity values by 60 min of recovery.
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Wiebe, Peter H., Gareth L. Lawson, Andone C. Lavery, Nancy J. Copley, Erich Horgan, and Albert Bradley. "Improved agreement of net and acoustical methods for surveying euphausiids by mitigating avoidance using a net-based LED strobe light system." ICES Journal of Marine Science 70, no. 3 (March 13, 2013): 650–64. http://dx.doi.org/10.1093/icesjms/fst005.
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Abstract Wiebe, P. H., Lawson, G. L., Lavery, A. C., Copley, N. J., Horgan, E., and Bradley, A. 2013. Improved agreement of net and acoustical methods for surveying euphausiids by mitigating avoidance using a net-based LED strobe light system. – ICES Journal of Marine Science, 70: 650–664. Euphausiids are known for their ability to avoid capture by standard plankton nets. Repeat sampling was conducted in the Gulf of Maine with a 1 m2 MOCNESS equipped with a light-emitting diode (LED)-based strobe light concurrent to multifrequency acoustic data collection. On cruise one, the strobe light's efficacy in reducing euphausiid net avoidance was evaluated on two horizontal tows where four of the eight nets were sampled with the strobe flashing and four with the strobe off. With the strobe light on, there was a significant increase in euphausiid abundance by a factor of 4.5 at night and by a factor of 11.0 during the day. There was also a significant increase in biovolume catch of zooplankton when the strobe light was on by factors of 2.2 at night and 5.5 during the day due to a higher abundance of 10 and 35 mm euphausiids. Euphausiids caught with the strobe light on accounted for most of the observed backscattering, and acoustic and net estimates of their abundance agreed. Similar results were obtained on cruise two. Agreement of acoustic and net estimates when using the strobe light suggests that reduced avoidance enhanced the efficiency of catching euphausiids.
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Butte, Giacomo, Yady Tatiana Solano-Correa, Maria Valasia Peppa, Diana Marcela Ruíz-Ordóñez, Rachael Maysels, Nasser Tuqan, Xanthe Polaine, Carolina Montoya-Pachongo, Claire Walsh, and Thomas Curtis. "A Framework for Water Security Data Gathering Strategies." Water 14, no. 18 (September 17, 2022): 2907. http://dx.doi.org/10.3390/w14182907.
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At the international level, the term “water security” (WS) has gained increasing attention in recent decades. At the operational level, WS is assessed using tools that define the concept using a variety of dimensions and sub-dimensions, with qualitative and quantitative indicators and parameters. The breadth of tools and concepts is an obstacle to the operationalisation of the concept of water security (WS). Clearly, we need a range of diverse data to evaluate water security (WS). However, there are several barriers to designing an optimal Data Gathering Strategy (DGS). Such a strategy must strike a balance between a wide range of competing and overlapping data requirements and characteristics including: resources, information, and impact. The proposed framework aims at filling the existing gaps, not by providing a strict procedure, but instead acting as a “compass”: five interfaces between data and context are identified to orient practitioners towards an optimal DGS. The conceptual aim of the framework can be summarised as shifting the focus of the DGS from a “data-to-information approach” to a “data-to-action approach,” therefore stressing the importance of reaching key stakeholders with information. The specific aims of this paper are to: identify the key issues that should be addressed in designing a Data Gathering Strategy for Water Security (DGSxWS); communicate the key issues with a clear conceptual framework; and suggest approaches and activities that could help water practitioners in dealing with the issues identified.
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Saylor, Ryan, Dustin Sterling, Mark Bevelhimer, and Brenda Pracheil. "Within and Among Fish Species Differences in Simulated Turbine Blade Strike Mortality: Limits on the Use of Surrogacy for Untested Species." Water 12, no. 3 (March 4, 2020): 701. http://dx.doi.org/10.3390/w12030701.
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Use of surrogacy remains a useful method for prioritizing research on representatives of at-risk groups of fishes, yet quantifiable evidence in support of its use is generally not available. Blade strike impact represents one of the most traumatic stressors experienced by fish during non-volitional movements through hydropower turbines. Here, we use data generated from laboratory trials on blade strike impact experiments to directly test use of surrogacy for salmonid and clupeid fishes. Results of logistic regression indicated that a -taxonomic (genus) variable was not a significant predictor of mortality among large rainbow trout and brook trout. Similar results were found for young-of-the-year shad species, but genus-level taxonomy was a significant predictor of mortality while species was not. Multivariate analysis of morphometric data showed that shad clustered together based on similarities in fish shape which was also closely associated with genus. Logistic regression including size as a major covariate suggested total fish length was not a significant predictor of mortality, yet dose–response data suggest differential susceptibility to lower strike velocities. We suggest that use of surrogacy among species is justifiable but should be avoided within a species since the effects of size remain unclear.
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van Esch, B. P. M., and I. L. Y. Spierts. "Validation of a model to predict fish passage mortality in pumping stations." Canadian Journal of Fisheries and Aquatic Sciences 71, no. 12 (December 2014): 1910–23. http://dx.doi.org/10.1139/cjfas-2014-0035.
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A total of 1253 live cyprinids and eel were exposed to a centrifugal pump to study fish damage rates in a wide operating range. The observed types of injuries were consistent with a mechanical cause of damage. The measured mortality rates for cyprinids show a fair agreement with a blade strike model based on empirical data by Electric Power Research Institute. Analysis of the experiments with eel led to a new correlation for the blade mortality ratio for this species; lethal injury rate is shown to be zero up to a strike velocity of 8 m·s–1 and increases linearly to 42% for a strike velocity of 15 m·s–1. Use was made of video recordings that provided valuable information on the orientation and distribution of fish approaching the impeller. Results are presented using a new method to visualize fish mortality from a pump in its entire operating range using graphs of pressure head versus flow rate. The theory of pump hydrodynamics is used to derive a method to scale results of fish damage rate, obtained either by a model or by experiments, to different pump sizes, shaft speeds, or fish lengths. This will prove essential for a valid interpretation of pump experiments with fish.
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Stepanuk, JEF, EI Heywood, JF Lopez, RA DiGiovanni Jr, and LH Thorne. "Age-specific behavior and habitat use in humpback whales: implications for vessel strike." Marine Ecology Progress Series 663 (March 31, 2021): 209–22. http://dx.doi.org/10.3354/meps13638.
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Vessel strikes are a major threat impacting large whales globally. Juvenile whales often represent a high proportion of lethal vessel strikes, but few studies have investigated whether juvenile whales show different behaviors that might influence their risk of vessel strike. We evaluated how variability in habitat use and foraging behavior by age class influences the risk of vessel strike for humpback whales Megaptera novaeangliae in the New York Bight (NYB), a highly urbanized region with frequent vessel strikes. We used data from unmanned aerial vehicle (UAV) surveys to compare the habitat use and foraging behavior of adult and juvenile humpback whales and compared length measurements of foraging individuals with those confirmed to have been killed by vessel strikes. Further, using Automatic Information System data, we analyzed the speed and density of vessel traffic relative to humpback whale habitat use. The vast majority (93%) of humpback whales confirmed to have been struck by vessels in the NYB were juveniles. Whales foraging in nearshore waters were exclusively juveniles that were surface feeding, while both juveniles and adults foraged cooperatively in offshore waters. Passenger vessel density and speed were highest in nearshore waters. The habitat use and surface foraging behavior of juvenile humpback whales may make them particularly vulnerable to vessel strikes in nearshore waters, and passenger vessels in these waters may be a risk factor. This work highlights the importance of understanding age-specific differences in habitat use to better understand and mitigate the risk of anthropogenic threats to large whales.
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HARPER, DAVID G., and ROBERT W. BLAKE. "Prey Capture and the Fast-Start Performance of Northern Pike Esox Lucius." Journal of Experimental Biology 155, no. 1 (January 1, 1991): 175–92. http://dx.doi.org/10.1242/jeb.155.1.175.
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Fast-start performance of northern pike Esox lucius (mean length, 0.38m) during prey capture was measured with subcutaneously implanted accelerometers. Acceleration-time plots and simultaneous high-speed ciné films reveal four behaviours with characteristic kinematics and mechanics. The fast-start types are identified by the number of large peaks that appear in the acceleration-time and velocity-time data. Comparisons of mean performance were made between each type of feeding fast-start. Type I fast-starts were of significantly shorter duration (0.084 s) and displacement (0.132 m) than type III (0.148 s and 0.235 m) and type IV (0.189 s and 0.306 m) behaviours, and higher mean and maximum acceleration (38.6 and 130.3 ms−2, respectively) than type II (26.6 and 95.8 ms−2), type III (22.0 and 91.2 ms−2) and type IV (18.0 and 66.6 m s−2) behaviours. The type II behaviours were of shorter duration (0.115 s) and displacement (0.173 m) and of higher mean acceleration than type IV fast-starts, and were also of significantly shorter duration than type III behaviours. Prey-capture performance was compared to escapes by the same individuals. When data are combined, regardless of mechanical type, mean acceleration (37.6 vs25.5ms−2), maximum acceleration (120.2 vs 95.9ms−2), mean velocity (1.90 vs 1.57 ms−1) and maximum velocity (3.97 vs 3.09 ms−1) were found to be larger and duration shorter (0.108 vs 0.133 s) during escapes than during prey capture. No differences were found through independent comparisons of the performance of feeding and escape types II and III, but type I escapes had significantly higher mean velocity (2.27 vs 1.58 ms−1), maximum velocity (4.70 vs 3.12 ms−1) and mean acceleration (54.7 vs 38.6 ms−2) than type II feeding behaviours. Prey-capture performance was also related to prey size, apparent prey size (defined as the angular size of the prey on the pike's retina) and strike distance (the distance from the pike to the prey at the onset of the fast-start). Mean and maximum acceleration increased with apparent size and decreased with strike distance, while the duration of the event increased with strike distance and decreased with apparent size. No relationship was found between the actual prey size and any performance parameter. Strike distance ranged from 0.087 to 0.439 m and decreased as the apparent size increased from 2.6 to 9.9° (r2=0.75). The type I behaviour was usually employed when the strike distance was small and the prey appeared large. As strike distance increased and apparent size decreased, there was a progressive selection of type II, then III and then IV behaviours.
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Kier, W., and J. Leeuwen. "A kinematic analysis of tentacle extension in the squid Loligo pealei." Journal of Experimental Biology 200, no. 1 (January 1, 1997): 41–53. http://dx.doi.org/10.1242/jeb.200.1.41.
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High-speed cine recordings of prey capture by the squid Loligo pealei were used to analyze the kinematics of the rapid tentacular strike. The proximal portion of the tentacle, the stalk, elongates during the strike. The non-extensible distal portion of the tentacle, the club, contacts the prey and attaches using suckers. Seven sequences of prey capture filmed at 750 frames s-1 were analyzed frame by frame. The positions of the head, the tentacles and the prey were digitized, and the data were smoothed using quintic natural B-splines and the generalized cross-validation (GCV) criterion. During the strike, the animal swims forward at velocities ranging from 0.7-1.2 m s-1, and as the eight arms are flared, the tentacular stalks elongate. Tentacular extension occurred in approximately 20-40 ms with peak strains in the tentacular stalk ranging from 0.43-0.8. Peak longitudinal strain rates varied from 23-45 s-1. Maximum extension velocities of the stalk were calculated to be over 2 m s-1 with peak accelerations of approximately 250 m s-2. Once the tentacular clubs have contacted the prey, the tentacular stalks are frequently observed to buckle.
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Blais, Jules M., and Edward J. Maly. "Differential Predation by Chaoborus americanus on Males and Females of Two Species of Diaptomus." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 2 (February 1, 1993): 410–15. http://dx.doi.org/10.1139/f93-046.
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Feeding experiments were performed to determine relative feeding rates of fourth-instar Chaoborus americanus larvae (Diptera) on both sexes of two calanoid copepod species, Diaptomus leptopus and D. minutus. Feeding rates, using a single prey type, showed that predation rates by Chaoborus on female D. minutus were highest, followed by male D. minutus, male D. leptopus, and female D. leptopus, respectively, when exposed to Chaoborus individually. Selectivity experiments with the four prey types made available simultaneously confirmed this pattern. Prey sizes and swimming speeds were determined, and both strike efficiency and handling time of Chaoborus were measured. Data suggested that selection between prey species was determined primarily by prey size whereas selection between sexes was determined primarily by differential swimming speed.
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Cruz-Marrero, Wilmelie, Chelsea A. Harms-Tuohy, Richard S. Appeldoorn, and Bradley G. Stevens. "Comparison of video camera sled with diver surveys for queen conch Lobatus gigas density estimates in the west coast of Puerto Rico." Bulletin of Marine Science 96, no. 4 (October 1, 2020): 641–54. http://dx.doi.org/10.5343/bms.2019.0087.
Full textAbstract:
Queen conch Lobatus gigas is one the most important fishery species in the Caribbean. Currently, queen conch harvest is prohibited in the Exclusive Economic Zone (EEZ) in Puerto Rico. Since 1996, abundance estimates in Puerto Rico have been conducted by scuba divers at intervals of 5 yrs. Yet diver surveys are limited by depth and time. In contrast, underwater video or camera surveys are not constrained by these factors and also provide a permanent photo record of observations. We conducted a survey of queen conch density on the western shelf of Puerto Rico in 2016 using two different methods: divers and a camera sled. Divers surveyed eight transects of 2–3 km using diver propulsion vehicles and standardized, historical methods. The camera sled was fitted with a digital camera, synchronized strobe lights, and paired lasers, and was towed along the dive transects several days later. Conch densities (conch ha–1) estimated with the camera sled were significantly higher than those estimated by diver survey methods, while mean length was smaller. Both results were driven by the higher selectivity of the sled method for smaller conch. These results may lead to further applications or development of sled survey techniques, and improved data collection and analysis that can be used for management of queen conch in the Caribbean.
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Di-Meglio, Nathalie, Lea David, and Pascal Monestiez. "Sperm whale ship strikes in the Pelagos Sanctuary and adjacent waters: assessing and mapping collision risks in summer." J. Cetacean Res. Manage. 18, no. 1 (January 24, 2023): 135–47. http://dx.doi.org/10.47536/jcrm.v18i1.446.
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Collisions with large vessels potentially present a major conservation issue for sperm whales in the Pelagos Sanctuary in the northwestern Mediterranean Sea. The exact numbers and locations of ship strikes remain largely unknown at present. In this study, sightings of sperm whales in summer (June–September) were gathered for the period between 1998 and 2008 from nine French and Italian organisations, together covering an area of more than 68,000km. Working on a regular grid of 0.1° × 0.1° latitude/longitude cells, approximate surface density of the whales was calculated using kriging methods. A database of shipping lanes of ferries and merchant vessels was assembled, and traffic density was mapped (kilometres travelled per cell). The data was overlayed and multiplied, using ArcGis, to create a relative density surface map of sperm whales correlated with the relative density of maritime traffic. Several maps of collision risk were drawn up according to the speed class of the vessels. Of living animals that had been photo-identified, 9% had scars attributed to ship strike. Results show that sperm whales are at high risk from merchant vessels along the French and Italian continental coasts and at risk from conventional ferries on the east side of the islands of Corsica and Sardinia. It was calculated that 74 animals could be in a ship strike risk situation during the summer period in the Pelagos Sanctuary. Based on these results, mitigation measures already in place were reviewed and new measures to reduce ship strike risk are suggested.
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Vanderlaan, Angelia S. M., R. Kent Smedbol, and Christopher T. Taggart. "Fishing-gear threat to right whales (Eubalaena glacialis) in Canadian waters and the risk of lethal entanglement." Canadian Journal of Fisheries and Aquatic Sciences 68, no. 12 (December 2011): 2174–93. http://dx.doi.org/10.1139/f2011-124.
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Commercial fishing gear can potentially entangle any whale, and this is especially true for the endangered North Atlantic right whale ( Eubalaena glacialis ), for which entanglement is second only to vessel strike as being responsible for documented right whale deaths. We use right whale survey data and Canadian fishing-gear deployment data to estimate the relative threat of gear entanglement in a Scotia–Fundy study area and the relative risk of lethal entanglement in the Bay of Fundy and on Roseway Basin, Scotian Shelf, where Critical Habitat has been legislated. We focus on groundfish and pelagic hook-and-line; groundfish gillnet; and crab-, hagfish-, and inshore and offshore lobster-trap gear. Our analyses demonstrate that groundfish hook-and-line gear poses the greatest threat to right whales among the seven gear types analysed during the summer-resident period in Critical Habitat and that gear from the lobster fisheries poses the greatest threat during the spring and autumn periods when whales are migrating to and from Critical Habitat. We suggest that area-specific seasonal closures of some fisheries would reduce threat and risk to whales without unduly compromising fishing interests.
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David, B. O., M. Lake, M. K. Pine, J. Smith, and J. A. T. Boubée. "Use of a novel acoustic 'listening' method for detecting pump impellor strike on downstream migrating eels." Marine and Freshwater Research 71, no. 6 (2020): 571. http://dx.doi.org/10.1071/mf19205.
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Fish mortality through floodplain pumping stations is a recognised global issue, but few studies have quantified the degree of mortality that occurs during pumping. We investigated the potential of passive acoustic monitoring (PAM) as a tool to record sounds made by fish and their likely mortality as they passed through pumps during downstream migration. The acoustic properties made by freshly killed eels that were fed through an existing pump station were compared to those made by goldfish (Carassius auratus). Processing and analysis of acoustic data enabled the development of an ‘eel-specific’ algorithm for detecting eels passing through the pumping station. The duration of sound and filtered intensity were useful characteristics enabling reliable separation of the two fish species. The algorithm was then applied retrospectively to soundscape recordings obtained during a typical eel migration period at the test site. Although the tool is unlikely to be able to differentiate the sound of goldfish from ‘other’ potential sounds of short duration (e.g. sticks), differentiating eels from other sounds was demonstrated. We conclude that this tool has considerable potential for improving the understanding of the timing of eel migrations and likely mortality through pumping stations. The tool may also be used to inform the development of both remote and manual pump management options for reducing pump-related eel mortality.
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Wood, Hannah M. "Morphology and performance of the ‘trap-jaw’ cheliceral strikes in spiders (Araneae, Mecysmaucheniidae)." Journal of Experimental Biology 223, no. 14 (June 19, 2020): jeb219899. http://dx.doi.org/10.1242/jeb.219899.
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ABSTRACTMecysmaucheniidae spiders have evolved ultra-fast cheliceral strikes 4 times independently. The mechanism for producing these high-speed strikes is likely due to a latch/spring system that allows for stored energy to be rapidly released. This study examined two different sister lineages: Zearchaea has ultra-fast cheliceral strikes and Aotearoa, based on external morphology of the clypeus, is hypothesized to have slower strikes. Using high-speed videography, I first gathered kinematic data on each taxon. Then, using histology and data from micro-computed tomography scanning, I examined internal cheliceral muscle morphology to test whether shifts in muscle anatomy correspond to performance differences in cheliceral strike. Results from high-speed video analysis revealed that Zearchaea achieves peak angular velocities of 25.0×103±4.8×103 rad s−1 (mean±s.d.) in durations of 0.0843±0.017 ms. The fastest recorded strike had a peak angular and linear velocity of 30.8×103 rad s−1 and 18.2 m s−1, respectively. The slower striking sister species, Aotearoa magna, was three orders of magnitude slower in velocity and longer in duration. Histology revealed sarcomere length differences, with some muscles optimized for force, and other muscles for speed. 3D printed models revealed structural differences that explain how the chelicerae hinge open and close. Combining all of this evidence, I put forth a hypothesis for the ultra-fast trap-jaw mechanism. This research documents the morphological shifts that accompany ultra-fast movements that result in increased rotation in joints and increased muscle specialization.
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Brandon, John R., and Andre E. Punt. "Testing the Gray Whale Strike Limit Algorithm (SLA): allowing environmental variability to influence population dynamics." J. Cetacean Res. Manage. 13, no. 1 (February 8, 2023): 81–88. http://dx.doi.org/10.47536/jcrm.v13i1.558.
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The performance of the Gray Whale SLA is evaluated based on an operating model conditioned on available information for the eastern North Pacific stock of gray whales including: survey estimates of 1+ abundance; calf counts; strandings data; and the extent of sea-ice in the feeding grounds in the Bering Sea in the early season. Multiple scenarios are considered in the analyses to explore the impact of different sources of environmental variation, including scenarios in which future environmental forcing and episodic events are driven by the relationships between reproductive success and survival to sea ice. A variety of sources of uncertainty are considered, including parameter uncertainty, the uncertainty about the relationship between the extent of sea-ice and population dynamics, and observation error. The impact of these sources of uncertainty on the performance of the Gray Whale SLA is small. For all scenarios considered in the simulations, application of the SLA results in the stock being at or near carrying capacity at the end of a 92 year projection period for which sea-ice cover forecasts are available, while still satisfying the needs of aboriginal whalers.