How a heavy-bodied snake strikes quickly: high-power axial musculature in the puff adder (Bitis arietans)

A biomechanical paradox in fish: swimming and suction feeding produce orthogonal strain gradients in the axial musculature

Scientific Reports ◽

10.1038/s41598-021-88828-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yordano E. Jimenez ◽

Richard L. Marsh ◽

Elizabeth L. Brainerd

Keyword(s):

High Power ◽

Strain Gradient ◽

Power Output ◽

Lepomis Macrochirus ◽

Bluegill Sunfish ◽

Muscle Strain ◽

Suction Feeding ◽

Optimal Velocity ◽

Axial Muscle ◽

Axial Musculature

AbstractThe axial musculature of fishes has historically been characterized as the powerhouse for explosive swimming behaviors. However, recent studies show that some fish also use their ‘swimming’ muscles to generate over 90% of the power for suction feeding. Can the axial musculature achieve high power output for these two mechanically distinct behaviors? Muscle power output is enhanced when all of the fibers within a muscle shorten at optimal velocity. Yet, axial locomotion produces a mediolateral gradient of muscle strain that should force some fibers to shorten too slowly and others too fast. This mechanical problem prompted research into the gearing of fish axial muscle and led to the discovery of helical fiber orientations that homogenize fiber velocities during swimming, but does such a strain gradient also exist and pose a problem for suction feeding? We measured muscle strain in bluegill sunfish, Lepomis macrochirus, and found that suction feeding produces a gradient of longitudinal strain that, unlike the mediolateral gradient for locomotion, occurs along the dorsoventral axis. A dorsoventral strain gradient within a muscle with fiber architecture shown to counteract a mediolateral gradient suggests that bluegill sunfish should not be able to generate high power outputs from the axial muscle during suction feeding—yet prior work shows that they do, up to 438 W kg−1. Solving this biomechanical paradox may be critical to understanding how many fishes have co-opted ‘swimming’ muscles into a suction feeding powerhouse.

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Dynamic Modeling and Wear-Based Remaining Useful Life Prediction of High Power Clutch Systems

Tribology Transactions ◽

10.1080/05698190590927451 ◽

2005 ◽

Vol 48 (2) ◽

pp. 208-217 ◽

Cited By ~ 32

Author(s):

Matthew Watson ◽

Carl Byington ◽

Douglas Edwards ◽

Sanket Amin

Keyword(s):

Dynamic Modeling ◽

High Power ◽

Life Prediction ◽

Remaining Useful Life ◽

Useful Life

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Less Power, Greater Conflict

Social Psychology ◽

10.1027/1864-9335/a000327 ◽

2018 ◽

Vol 49 (1) ◽

pp. 47-62 ◽

Cited By ~ 1

Author(s):

Petra C. Schmid

Keyword(s):

Low Power ◽

High Power ◽

Goal Pursuit ◽

Goal Conflict ◽

Personal Goals ◽

Multiple Goals ◽

Objective Performance ◽

The Future ◽

The Way

Abstract. Power facilitates goal pursuit, but how does power affect the way people respond to conflict between their multiple goals? Our results showed that higher trait power was associated with reduced experience of conflict in scenarios describing multiple goals (Study 1) and between personal goals (Study 2). Moreover, manipulated low power increased individuals’ experience of goal conflict relative to high power and a control condition (Studies 3 and 4), with the consequence that they planned to invest less into the pursuit of their goals in the future. With its focus on multiple goals and individuals’ experiences during goal pursuit rather than objective performance, the present research uses new angles to examine power effects on goal pursuit.

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