The changes in power requirements and muscle efficiency during elevated force production in the fruit fly Drosophila melanogaster.
The changes in power requirements and muscle efficiency during elevated force production in the fruit fly Drosophila melanogaster.
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发表时间：
1997-04
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通讯作者：
F. Lehmann;M. Dickinson
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作者：
F. Lehmann;M. Dickinson
在“虚拟现实”飞行舞台上，通过调节功率需求，估计了拴着的黑腹果蝇的飞行性能极限。飞行肌肉在24摄氏度的环境下，可以承受高达80瓦公斤-1肌肉质量的机械输出力，这足以产生相当于动物体重150%的力量。当飞行力超过支撑体重所需的飞行力时，伴随着翼速的上升，这是由冲程幅度的增加和冲程频率的减少引起的。惯性成本，虽然大于外形或诱导功率，但即使是适度的弹性存储，也将是最小的，总的机械动力能量应该相当于单独的空气动力。由于在低雷诺数下预期的大剖面阻力，在所有发力级别上，剖面功率大约是诱导功率的两倍。因此，克服阻力的成本，而不是产生升力的成本，是果蝇飞行的主要要求。通过比较估计的机械功率输出和呼吸计测量的总功率输入，我们确定肌肉效率随着力量输出的增加而增加，最高可达10%。这种效率的变化可能反映了在产生峰值力期间增加的过桥激活或有利的应变制度。
The limits of flight performance have been estimated in tethered Drosophila melanogaster by modulating power requirements in a 'virtual reality' flight arena. At peak capacity, the flight muscles can sustain a mechanical power output of nearly 80 W kg-1 muscle mass at 24 degrees C, which is sufficient to generate forces of approximately 150% of the animal's weight. The increase in flight force above that required to support body weight is accompanied by a rise in wing velocity, brought about by an increase in stroke amplitude and a decrease in stroke frequency. Inertial costs, although greater than either profile or induced power, would be minimal with even modest amounts of elastic storage, and total mechanical power energy should be equivalent to aerodynamic power alone. Because of the large profile drag expected at low Reynolds numbers, the profile power was approximately twice the induced power at all levels of force generation. Thus, it is the cost of overcoming drag, and not the production of lift, that is the primary requirement for flight in Drosophila melanogaster. By comparing the estimated mechanical power output with respirometrically measured total power input, we determined that muscle efficiency rises with increasing force production to a maximum of 10%. This change in efficiency may reflect either increased crossbridge activation or a favorable strain regime during the production of peak forces.