Contracts timing

Inter-digestive migrating contraction Time for 50% emptying of the stomach Technetium-99m... 

There is probably no biological phenomenon that has excited more interest among biochemists than the movement caused by the contractile fibers of muscles. Unlike the motion of bacterial flagella, the movement of muscle is directly dependent on the hydrolysis of ATP as its source of energy. Several types of muscle exist within our bodies. Striated (striped) skeletal muscles act under voluntary control. Closely related are the involuntary striated heart muscles, while smooth involuntary muscles constitute a third type. Further distinctions are made between fast-twitch and slow-twitch fibers. Fast-twitch fibers have short isometric contraction times, high maximal velocities for shortening, and high rates of ATP hydrolysis. 

Figure 5.5 Dependence of experimental and calculated rates of methane consumption on the contract time rexp is the experimental rate rca c(l) is the rate calculated from equations (5.31)—(5.35) and rcaic(2) is the rate calculated from equation (5.36).

Other new echocardiographic methods have been employed in evaluation of PAH. One of them is strain imaging, which measures deformation over time it has been used in concert with TAPSE and RV Tei index (isovolumic contraction time and relaxation time/ejec-tion time [TVt - RVt]/RVt), and has been shown to be reduced in patients with acute pulmonary embolus and improved after stabilization (37). Using parameters of the eccentricity index, which highlight RV/LV interdependence, it was shown that an eccentricity index less than median was associated with improved survival and freedom from a composite endpoint (38). Lastly, the newer technique of vector velocity imaging applied to the right ventricle is promising as a quantitative assessment of RV function and reserve. 

Measurements of twitch contraction times reflect the rates of Ca flow into and out of the myoplasm. The time to peak twitch force is influenced by the rate of increase in myoplasmic Ca . Conversely, half relaxation time of twitch force is influenced by the rate of decrease in myoplasmic Ca " (reflecting primarily SERCA activity). Values for time to peak twitch force and half relaxation time of twitch force also vary across muscles, such that muscles composed of predominantly type II fibers have shorter times compared to those composed of predominantly type I fibers (Larsson et al, 1994 Vedsted et al, 2003). 

Figure 111.4 Isometric twitch contraction times. Time to peak twitch force (a) and half relaxation time of twitch force (b) are plotted for rat diaphragm muscle strips. Hypothyroidism was induced for 3 months in the rats prior to tissue extraction and in vitro evaluation. Hypothyroidism resulted in prolonged time to peak twitch force and half relaxation time. lndicates statistically significant difference from control muscle strips (p < 0.05). Error bars are SEM.

The force generated by a muscle is proportional to the contraction time. The longer the contraction time, the greater the force development up to the point of maximum tension. Slower contraction leads to greater force production because more time is allowed for the tension produced in contractile elements to be transferred through the noncontractile components to the tendon. This is the force-time relationship. Tension in the tendon will reach the maximum tension developed by the contractile tissues only if the active contraction process is of adequate (even up to 300 msec) duration [Sukop and Nelson, 1974). 

The completion The contract time limit for a project performance... 

If the contract timing can be made as flexible as possible then the contractor can maximise plant efficiently and avoid undesirable weather seasons. 

Long contract times with effluent may be needed... 

Multisite atrial pacing techniques have been shown to prevent atrial dilatation, decrease total atrial contraction time, and decrease the conduction slowing which occurs with atrial pranature beats which can trigger atrial fibrillation (86-88). Consequently, there has been significant interest in the... 

Length Contraction, Time Diiation, and Proper Time... 

Diazomethane can be prepared by decomposing p-toluenesulphonamide in an alcohol in alkali solution [550]. The ether solution of diazomethane is placed in a closed glass apparatus with a polymer film. Ether is then allowed to evaporate. The contract time with the film is 3 h at — 78°C (closed system) [2316]. 

There can be no float time in any of the activities which form a part of the critical path, since a delay on any of these activities would delay completion of the contract. On the other two paths some delay could occur without affecting the overall contract time. 

The critical path is therefore path 3, via events 1 -3-6 7, and the total contract time is 10 weeks. 

Komandur S, Johnson P, Storch R.L (2008) Relation between mouse button click duration and muscle contraction time. 30th Annual International IEEE EMBS Conference... 

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