... mollusks respond to chronic mechanical stress. Once a week for 7 months, we compressed whole live California mussels ( Mytilus californianus ) for 15 cycles at ∼55% of their predicted one-time breaking force, a treatment known to cause fatigue damage in shells. We found mussels repaired their shells...

...Sharn P. Shelley; Rob S. James; Steven J. Eustace; Emma Eyre; Jason Tallis ABSTRACT This study examined the effect of stimulation frequency (140, 200, 230 and 260 Hz) on isometric force, work loop (WL) power and the fatigue resistance of extensor digitorum longus (EDL) muscle ( n =32), isolated...

... resistance to single impacts but perform poorly under multiple impacts owing to their layered structure; impact damage is often fatal but can be repaired. Limpet Patella vulgata Fatigue Damage Spalling Delamination The term ‘limpet’ is used rather loosely to include any aquatic snail...

... with thapsigargin reduced muscle fatigue resistance, but hypothyroidism had no effect on fatigue. Hence, thyroid hormone plays a role in determining isolated skeletal muscle mechanics, but its effects are more likely to be mediated by mechanisms other than affecting SERCA activity. Sustained swimming performance...

...Glen A. Lichtwark; Andrew G. Cresswell; Richard J. Newsham-West SUMMARY The elastic properties of the human Achilles tendon are important for locomotion; however, in vitro tests suggest that repeated cyclic contractions lead to tendon fatigue – an increase in length in response to stress applied...

..., suggesting one potential mechanism for maintenance of acute muscle performance. Soleus muscle fatigue resistance was significantly lower in torpid than in summer animals. Gastrocnemius muscle glycogen content was unchanged. However, state 3 and state 4 mitochondrial respiration rates were significantly...

... perennially underestimated rates of macroalgal breakage. Recent laboratory testing has established that some seaweeds fail by fatigue, accumulating damage over a series of force impositions. Failure by fatigue may thus account, in part, for the discrepancy between prior breakage predictions, based...

... [not significant (n.s.)]. Despite the lack of changes in stiffness, maximum tendon force during MVC was reduced from 3.5±0.6 kN to 2.8±0.7 kN ( P <0.01). As the proposed decline in stiffness was not observed, it is concluded that mechanical fatigue did not take place in the AT of healthy individuals after...

...Katharine J. Mach SUMMARY On rocky shores, wave-swept macroalgae experience dramatic and repeated wave-induced hydrodynamic forces. However, previous studies of macroalgal mechanics have shown that individual waves are not forceful enough to account for observed rates of breakage. Instead, fatigue...

... an alga. In contrast, intertidal macroalgae may experience more than 8000 waves a day. This repeated loading can cause cracks– introduced, for example, by herbivory or abrasion – to grow and eventually cause breakage, yet fatigue crack growth has not previously been taken into account. Here, we present...

... impositions of maximal field forces. Nonetheless, macroalgae break frequently. Here we investigate the possibility that repeated loading by sub-lethal forces can eventually cause fracture by fatigue. We determine fracture toughness, in the form of critical strain energy release rate, for several flat-bladed...

... times, absolute force, relative force (stress)and fatigue between male and female frogs. We found that ECR muscle mass and length were greater (tenfold and 1.4-fold, respectively), absolute tetanic muscle force and relative tetanic force (stress) were greater (16-fold and 2.2-fold, respectively...

... fish; running animals; piston engines; electric motors; jets) comprises motors that cycle rapidly, with significant internal and external accelerations, and for whom inertia and fatigue life appear to be important constraints. The scaling of inertial loads and fatigue life both appear to enforce F max...

... , but rather post-exercise inactivity. * e-mail: [email protected] 05 01 2000 10 02 2000 © 2000 by Company of Biologists 2000 exercise cortisol catecholamine glycogen lactate muscle swimming fatigue rainbow trout Oncorhynchus mykiss Metabolic...

...Graham N. Askew; Iain S. Young; John D. Altringham ABSTRACT The function of many muscles requires that they perform work. Fatigue of mouse soleus muscle was studied in vitro by subjecting it to repeated work loop cycles. Fatigue resulted in a reduction in force, a slowing of relaxation...

...Xiao Tong Wang; Robert F. Ker; R. Mcneill Alexander ABSTRACT Wallaby tail tendons fail after repeated application of stresses much lower than would be needed to break them in a single pull. We show that this is a fatigue phenomenon, distinct from the creep rupture that occurs after prolonged...

...Tomoaki Yoshikawa; Satoshi Mori; A. J. Santiesteban; T. C. Sun; Else Hafstad; Jie Chen; David B. Burr ABSTRACT There is anecdotal evidence that bone strains may increase to the point that bone becomes susceptible to rapid failure when muscles become fatigued. To determine whether neuromuscular...

... exhausted, although they would no longer swim at a steady speed. As pHi of the red muscle was the same at U crit for fish at neutral and at sublethal pH, it is suggested that U crit (fatigue) coincides with a particular pHi of the red muscles and possible mechanisms are discussed. 6 11 1992 ©...

... −1 ) tensions, and also fatigued less than muscles with limited blood supply but no stimulation. Histochemical estimation of capillary density (by staining for alkaline phosphatase) and slow (SO) and fast (FOG) fibres (by myosin ATPase staining) revealed similar capillary to fibre ratios (2.5...

... suited to optimize the release process at the terminal by utilizing a frequency-facilitation mechanism and by minimizing a mechanism of fatigue in the release process. The different properties of oxytocin and vasopressin neurones are of important physiological significance. The secretory terminals...