A relatively simple method is presented for incorporating cross-bridge mechanisms into a muscle model. The method is based on representing force in a half sarcomere as the product of the stiffness of all parallel cross bridges and their average distortion. Differential equations for sarcomeric stiffness are derived from a three-state kinetic scheme for the cross-bridge cycle. Differential equat...

We investigated the effects of aging on Drosophila melanogaster indirect flight muscle from the whole organism to the actomyosin cross-bridge. Median-aged (49-day-old) flies were flight impaired, had normal myofilament number and packing, barely longer sarcomeres, and slight mitochondrial deterioration compared with young (3-day-old) flies. Old (56-day-old) flies were unable to beat their wings...

In the field of civil engineering and architecture, concept symmetry has been widely accepted. The bridge can be treated as a typical symmetrical structure buildings. Among them, Subgrade identified an important part to bear vehicle loads. Severe pavement problems service capabilities will caused by bridge–subgrade transition section. Therefore, setting rigid–flexible is method solve this probl...

Muscle fatigue reflects alterations of both activation and cross-bridge function, which will have markedly different affects on steady-state vs. dynamic performance. Such differences offer insight into the specific origins of fatigue, its mechanical manifestation, and its consequences for animal movement. These were inferred using dynamic contractions (twitches and cyclic work as might occur du...

Studies of the passive mechanical properties of cardiac tissue have traditionally been conducted at subphysiological temperatures and various concentrations of extracellular Ca(2+) ([Ca(2+)](o)). More recently, the negative inotropic agent 2,3-butanedione monoxime (BDM) has been used. However, there remains a lack of data regarding the influence of temperature, Ca(2+), and BDM on the passive me...

A previous paper [Woodhouse et al., Acta Acustica 5, 15 (2021) https://doi.org/10.1051/aacus/2021009 ] showed acoustical measurements of an American 5-string banjo alongside similar on a guitar, revealing strong contrast in bridge admittance. Theoretical and numerical modelling is now presented to probe the physics behind this contrast. Without strings, membrane has rising trend admittance asso...

The effects of halothane, isoflurane, and sevoflurane on elastic stiffness, which reflects the degree of cross-bridge attachment, were studied in intact cardiac muscle. Electrically stimulated (0.25 Hz, 25 degrees C), isometrically twitching right ventricular ferret papillary muscles (n = 15) at optimal length (L(max)) were subjected to sinusoidal length oscillations (40 Hz, 0.25- 0.50% of L(ma...

According to the cross-bridge theory, the steady-state isometric force of a muscle is given by the amount of actin-myosin filament overlap. However, it has been known for more than half a century that steady-state forces depend crucially on contractile history. Here, we examine history-dependent steady-state force production in view of the cross-bridge theory, available experimental evidence, a...