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Kurt Schwenk - One of the best experts on this subject based on the ideXlab platform.

  • The Mechanics of air Breathing in gray tree frog tadpoles, Hyla versicolor (Anura: Hylidae).
    The Journal of Experimental Biology, 2020
    Co-Authors: Jackson R. Phillips, Amanda E. Hewes, Kurt Schwenk
    Abstract:

    ABSTRACT We describe air-Breathing Mechanics in gray tree frog tadpoles (Hyla versicolor). We found that H. versicolor tadpoles breathe by ‘bubble-sucking’, a Breathing mode typically employed by tadpoles too small to break the water9s surface tension, in which a bubble is drawn into the buccal cavity and compressed into the lungs. In most tadpoles, bubble-sucking is replaced by breach Breathing (breaking the surface to access air) at larger body sizes. In contrast, H. versicolor tadpoles bubble-suck throughout the larval period, despite reaching body sizes at which breaching is possible. Hyla versicolor tadpoles exhibit two bubble-sucking behaviors: ‘single bubble-sucking’, previously described in other tadpole species, is characterized by a single suction event followed by a compression phase to fill the lungs; ‘double bubble-sucking’ is a novel, apparently derived form of bubble-sucking that adds a second suction event. Hyla versicolor tadpoles transition from single bubble-sucking to double bubble-sucking at approximately 5.7 mm snout–vent length (SVL), which corresponds to a period of rapid lung maturation when they transition from low to high vascularization (6.0 mm SVL). Functional, behavioral and morphological evidence suggests that double bubble-sucking increases the efficiency of pulmonary gas exchange by separating expired, deoxygenated air from freshly inspired air to prevent mixing. Hyla versicolor, and possibly other hylid tadpoles, may have specialized for bubble-sucking in order to take advantage of this increased efficiency. Single and double bubble-sucking represent two- and four-stroke ventilation systems, which we discuss in the context of other anamniote air-Breathing mechanisms.

  • the Mechanics of air Breathing in gray tree frog tadpoles hyla versicolor leconte 1825 anura hylidae
    The Journal of Experimental Biology, 2020
    Co-Authors: Jackson R. Phillips, Amanda E. Hewes, Kurt Schwenk
    Abstract:

    ABSTRACT We describe air-Breathing Mechanics in gray tree frog tadpoles (Hyla versicolor). We found that H. versicolor tadpoles breathe by ‘bubble-sucking’, a Breathing mode typically employed by tadpoles too small to break the water9s surface tension, in which a bubble is drawn into the buccal cavity and compressed into the lungs. In most tadpoles, bubble-sucking is replaced by breach Breathing (breaking the surface to access air) at larger body sizes. In contrast, H. versicolor tadpoles bubble-suck throughout the larval period, despite reaching body sizes at which breaching is possible. Hyla versicolor tadpoles exhibit two bubble-sucking behaviors: ‘single bubble-sucking’, previously described in other tadpole species, is characterized by a single suction event followed by a compression phase to fill the lungs; ‘double bubble-sucking’ is a novel, apparently derived form of bubble-sucking that adds a second suction event. Hyla versicolor tadpoles transition from single bubble-sucking to double bubble-sucking at approximately 5.7 mm snout–vent length (SVL), which corresponds to a period of rapid lung maturation when they transition from low to high vascularization (6.0 mm SVL). Functional, behavioral and morphological evidence suggests that double bubble-sucking increases the efficiency of pulmonary gas exchange by separating expired, deoxygenated air from freshly inspired air to prevent mixing. Hyla versicolor, and possibly other hylid tadpoles, may have specialized for bubble-sucking in order to take advantage of this increased efficiency. Single and double bubble-sucking represent two- and four-stroke ventilation systems, which we discuss in the context of other anamniote air-Breathing mechanisms.

Jackson R. Phillips - One of the best experts on this subject based on the ideXlab platform.

  • The Mechanics of air Breathing in gray tree frog tadpoles, Hyla versicolor (Anura: Hylidae).
    The Journal of Experimental Biology, 2020
    Co-Authors: Jackson R. Phillips, Amanda E. Hewes, Kurt Schwenk
    Abstract:

    ABSTRACT We describe air-Breathing Mechanics in gray tree frog tadpoles (Hyla versicolor). We found that H. versicolor tadpoles breathe by ‘bubble-sucking’, a Breathing mode typically employed by tadpoles too small to break the water9s surface tension, in which a bubble is drawn into the buccal cavity and compressed into the lungs. In most tadpoles, bubble-sucking is replaced by breach Breathing (breaking the surface to access air) at larger body sizes. In contrast, H. versicolor tadpoles bubble-suck throughout the larval period, despite reaching body sizes at which breaching is possible. Hyla versicolor tadpoles exhibit two bubble-sucking behaviors: ‘single bubble-sucking’, previously described in other tadpole species, is characterized by a single suction event followed by a compression phase to fill the lungs; ‘double bubble-sucking’ is a novel, apparently derived form of bubble-sucking that adds a second suction event. Hyla versicolor tadpoles transition from single bubble-sucking to double bubble-sucking at approximately 5.7 mm snout–vent length (SVL), which corresponds to a period of rapid lung maturation when they transition from low to high vascularization (6.0 mm SVL). Functional, behavioral and morphological evidence suggests that double bubble-sucking increases the efficiency of pulmonary gas exchange by separating expired, deoxygenated air from freshly inspired air to prevent mixing. Hyla versicolor, and possibly other hylid tadpoles, may have specialized for bubble-sucking in order to take advantage of this increased efficiency. Single and double bubble-sucking represent two- and four-stroke ventilation systems, which we discuss in the context of other anamniote air-Breathing mechanisms.

  • the Mechanics of air Breathing in gray tree frog tadpoles hyla versicolor leconte 1825 anura hylidae
    The Journal of Experimental Biology, 2020
    Co-Authors: Jackson R. Phillips, Amanda E. Hewes, Kurt Schwenk
    Abstract:

    ABSTRACT We describe air-Breathing Mechanics in gray tree frog tadpoles (Hyla versicolor). We found that H. versicolor tadpoles breathe by ‘bubble-sucking’, a Breathing mode typically employed by tadpoles too small to break the water9s surface tension, in which a bubble is drawn into the buccal cavity and compressed into the lungs. In most tadpoles, bubble-sucking is replaced by breach Breathing (breaking the surface to access air) at larger body sizes. In contrast, H. versicolor tadpoles bubble-suck throughout the larval period, despite reaching body sizes at which breaching is possible. Hyla versicolor tadpoles exhibit two bubble-sucking behaviors: ‘single bubble-sucking’, previously described in other tadpole species, is characterized by a single suction event followed by a compression phase to fill the lungs; ‘double bubble-sucking’ is a novel, apparently derived form of bubble-sucking that adds a second suction event. Hyla versicolor tadpoles transition from single bubble-sucking to double bubble-sucking at approximately 5.7 mm snout–vent length (SVL), which corresponds to a period of rapid lung maturation when they transition from low to high vascularization (6.0 mm SVL). Functional, behavioral and morphological evidence suggests that double bubble-sucking increases the efficiency of pulmonary gas exchange by separating expired, deoxygenated air from freshly inspired air to prevent mixing. Hyla versicolor, and possibly other hylid tadpoles, may have specialized for bubble-sucking in order to take advantage of this increased efficiency. Single and double bubble-sucking represent two- and four-stroke ventilation systems, which we discuss in the context of other anamniote air-Breathing mechanisms.

Amanda E. Hewes - One of the best experts on this subject based on the ideXlab platform.

  • The Mechanics of air Breathing in gray tree frog tadpoles, Hyla versicolor (Anura: Hylidae).
    The Journal of Experimental Biology, 2020
    Co-Authors: Jackson R. Phillips, Amanda E. Hewes, Kurt Schwenk
    Abstract:

    ABSTRACT We describe air-Breathing Mechanics in gray tree frog tadpoles (Hyla versicolor). We found that H. versicolor tadpoles breathe by ‘bubble-sucking’, a Breathing mode typically employed by tadpoles too small to break the water9s surface tension, in which a bubble is drawn into the buccal cavity and compressed into the lungs. In most tadpoles, bubble-sucking is replaced by breach Breathing (breaking the surface to access air) at larger body sizes. In contrast, H. versicolor tadpoles bubble-suck throughout the larval period, despite reaching body sizes at which breaching is possible. Hyla versicolor tadpoles exhibit two bubble-sucking behaviors: ‘single bubble-sucking’, previously described in other tadpole species, is characterized by a single suction event followed by a compression phase to fill the lungs; ‘double bubble-sucking’ is a novel, apparently derived form of bubble-sucking that adds a second suction event. Hyla versicolor tadpoles transition from single bubble-sucking to double bubble-sucking at approximately 5.7 mm snout–vent length (SVL), which corresponds to a period of rapid lung maturation when they transition from low to high vascularization (6.0 mm SVL). Functional, behavioral and morphological evidence suggests that double bubble-sucking increases the efficiency of pulmonary gas exchange by separating expired, deoxygenated air from freshly inspired air to prevent mixing. Hyla versicolor, and possibly other hylid tadpoles, may have specialized for bubble-sucking in order to take advantage of this increased efficiency. Single and double bubble-sucking represent two- and four-stroke ventilation systems, which we discuss in the context of other anamniote air-Breathing mechanisms.

  • the Mechanics of air Breathing in gray tree frog tadpoles hyla versicolor leconte 1825 anura hylidae
    The Journal of Experimental Biology, 2020
    Co-Authors: Jackson R. Phillips, Amanda E. Hewes, Kurt Schwenk
    Abstract:

    ABSTRACT We describe air-Breathing Mechanics in gray tree frog tadpoles (Hyla versicolor). We found that H. versicolor tadpoles breathe by ‘bubble-sucking’, a Breathing mode typically employed by tadpoles too small to break the water9s surface tension, in which a bubble is drawn into the buccal cavity and compressed into the lungs. In most tadpoles, bubble-sucking is replaced by breach Breathing (breaking the surface to access air) at larger body sizes. In contrast, H. versicolor tadpoles bubble-suck throughout the larval period, despite reaching body sizes at which breaching is possible. Hyla versicolor tadpoles exhibit two bubble-sucking behaviors: ‘single bubble-sucking’, previously described in other tadpole species, is characterized by a single suction event followed by a compression phase to fill the lungs; ‘double bubble-sucking’ is a novel, apparently derived form of bubble-sucking that adds a second suction event. Hyla versicolor tadpoles transition from single bubble-sucking to double bubble-sucking at approximately 5.7 mm snout–vent length (SVL), which corresponds to a period of rapid lung maturation when they transition from low to high vascularization (6.0 mm SVL). Functional, behavioral and morphological evidence suggests that double bubble-sucking increases the efficiency of pulmonary gas exchange by separating expired, deoxygenated air from freshly inspired air to prevent mixing. Hyla versicolor, and possibly other hylid tadpoles, may have specialized for bubble-sucking in order to take advantage of this increased efficiency. Single and double bubble-sucking represent two- and four-stroke ventilation systems, which we discuss in the context of other anamniote air-Breathing mechanisms.

Tony G Babb - One of the best experts on this subject based on the ideXlab platform.

  • weight loss via diet and exercise improves exercise Breathing Mechanics in obese men
    Chest, 2011
    Co-Authors: Tony G Babb, Brenda L Wyrick, P J Chase, Darren S Delorey, Susan G Rodder, Mabel Y Feng, Kamalini G Ranasinghe
    Abstract:

    Background Obesity alters Breathing Mechanics during exercise. Weight loss improves lung function at rest, but the effect of weight loss, especially regional fat loss, on exercise Breathing Mechanics is unclear. We hypothesized that weight loss, especially a decrease in abdominal fat, would improve Breathing Mechanics during exercise because of an increase in end-expiratory lung volume (EELV). Methods Nine obese men were studied before and after weight loss (13% ± 8% of total fat weight, mean ± SD). Subjects underwent pulmonary function testing, underwater weighing, fat distribution estimates (MRI), and graded cycle ergometry before and after a 12-week diet and exercise program. In seven men, esophageal and gastric pressures were measured. The effects of weight loss were analyzed at rest, at ventilatory threshold (VTh), and during peak exercise by dependent Student t test, and the relationship among variables was determined by correlation analysis. Results Subjects lost 7.4 ± 4.2 kg of body weight (P Conclusions Modest weight loss improves Breathing Mechanics during submaximal exercise in otherwise healthy obese men, which is clinically encouraging. Improvement appears to be related to the cumulative loss of chest wall fat.

  • Breathing Mechanics during exercise with added dead space reflect mechanisms of ventilatory control
    Respiratory Physiology & Neurobiology, 2009
    Co-Authors: Helen E Wood, Gordon S Mitchell, Tony G Babb
    Abstract:

    Small increases in external dead space (V(D)) augment the exercise ventilatory response via a neural mechanism known as short-term modulation (STM). We hypothesized that Breathing Mechanics would differ during exercise, increased V(D) and STM. Men were studied at rest and during cycle exercise (10-50W) without (Control) and with added V(D) (200-600ml). With added V(D), V(T) increased via increased end-inspiratory lung volume (EILV), with no change in end-expiratory lung volume (EELV), indicating recruitment of inspiratory muscles only. With exercise, V(T) increased via both decreased EELV and increased EILV, indicating recruitment of both expiratory and inspiratory muscles. A significant interaction between the effects of exercise and V(D) on mean inspiratory flow indicated that the augmented exercise ventilatory response with added V(D) (i.e. STM) resulted from increased drive to the inspiratory muscles. These results reveal different patterns of respiratory muscle recruitment among experimental conditions. Hence, we conclude that fundamental differences exist in the neural control of ventilatory responses during exercise, increased V(D) and STM.

P Sliwinski - One of the best experts on this subject based on the ideXlab platform.

  • expiratory muscle pressure and Breathing Mechanics in chronic obstructive pulmonary disease
    European Respiratory Journal, 2000
    Co-Authors: Sheng Yan, C Sinderby, P Bielen, J Beck, N Comtois, P Sliwinski
    Abstract:

    Expiratory muscle recruitment is common in stable chronic obstructive pulmonary disease (COPD) patients. Due to airway obstruction, there is little reason to believe that active expiration in COPD would be mechanically effective in lowering operating lung volume. The physiological significance of expiratory muscle recruitment in COPD, therefore, remains unknown. The purpose of this study was to assess, in COPD patients Breathing at rest, the effect of expiratory muscle contraction on force generating ability of the diaphragm. The force generating ability of the diaphragm was evaluated from its pressure swing (Pdi) for a given diaphragm electrical activity (Edi), where Edi was normalized as % of its maximal value (Pdi/Edi/Edi,max). Phasic expiratory muscle contraction was measured as the total expiratory rise in gastric pressure (Pga,exp.rise). Nineteen seated patients with moderate to severe COPD, participated in the study and 10 exhibited phasic rise in Pga during expiration with a mean Pga,exp.rise of 1.91+/-0.89 cmH2O. The patients were thus divided into passive expiration (PE) and active expiration (AE) groups. There was no significant difference in various lung function and Breathing pattern parameters between the two groups. Pdi/Edi/Edi,max was 0.63+/-0.07 and 0.54+/-0.07 cmH2O/% in PE and AE groups, respectively, and was not significantly different between each other. Compared with PE group, AE group not only recruited expiratory muscles, but also preferentially recruited inspiratory rib cage muscles and derecruited the diaphragm. The results do not support a significant improvement of the force-generating ability of the diaphragm by phasic contraction of expiratory muscles at rest in chronic obstructive pulmonary disease patients.