Single threshold

At the same time, non-linear mechanisms may also possibly be involved in the transport, metabolism, repair and elimination processes involved in mutagenesis (Hoel et oL, 1983). A single threshold step in such a sequence would suffice to give the overall process a threshold. Furthermore, even if mutagenesis at low doses involved a combination... 

Furthermore, the results of Cain and Cometto-Muniz [14] indicate that complex chemical environments may enable chemosensory and particularly irritative detection when single VOCs lie far below their individual thresholds. This means that in gas mixtures the nose may detect even far below single thresholds, i.e. below the parts-per-trillion to parts-per-billion range. 

The current-versus-voltage dependence for a single-threshold device is written as... 

As another example of additional subtleties in the NAS (1977) report, the report addresses population heterogeneity by noting that such heterogeneity would result in multiple thresholds (for different people or populations) and that it would be difficult to establish a single threshold. The report also notes the difficulty in distinguishing statistically between models that hypothesize multiple thresholds and... 

In discussing thresholds for carcinogenesis, Rail (36) and Brown (37) argue against the existence of a single threshold, but rather that thresholds are likely to vary among members of the population at risk and may be modified by other environmental agents. Mantel, et al. (38) and Brown (37) show mathematically... 

Properties of the model in the absence of recycling excitability with a single threshold, oscillations and bistability... 

Fig. 3.12. Excitability with a single threshold. Despite the presence of two regions of negative slope on the product nullcline, a unique threshold is obtained for the excitable response, as a result of the position of the steady state with respect to the first of these regions (Moran Goldbeter, 1985).

The question arises as to whether thresholds are needed in the two cycles of the cascade of fig. 10.4, or if a single threshold in either one of these cycles suffices to allow for sustained oscillatory behaviour. Although the occurrence of thresholds in the transition curves for both M and X definitely favours oscillations, stability diagrams established as a function of the various parameters of the model indicate that periodic... 

Fig. 10.9. Sustained oscillations in the minimal cascade model involving cyclin and cdc2 kinase, in conditions where a single threshold exists in (a) the second or (b) the first cycle of the cascade (Guilmot Goldbeter, 1995). Figure 10.6, in contrast, was established for the case where a threshold occurs in both cycles. Parameter values are those of Fig. 10.8a. Initial conditions are C (in xM) = M = X = 0.5 in (a) and 0.2 in (b). Moreover, in (a) Ki = K2 100 and 0.001, while in (b) K =K2 = 0.001 and K = K = 100.

The existence of two thresholds clearly favours the occurrence of sustained oscillations of significant amplitude in both M and X (see fig. 10.6), even if a single threshold suffices for oscillatory behaviour. The domain of parameter values for which oscillations occur is, however, much reduced when only one cycle of the bicyclic cascade possesses a sharp threshold. It remains possible that the requirement for at least one threshold depends on the number of cycles comprised in the cascade. Extending the model to include additional phosphory-lation-dephosphorylation cycles allows us to address this issue as well as the influence of self-amplification in cdc2 kinase activation. 

Over years of study, tolerances have been established for most responses of the chest and abdomen. Table 53.1 provides tolerance levels from reviews by Cavanaugh [1993], and Rouhana [1993], Viano et al. [1989]. While these are single thresholds, they are commonly used to evaluate safety systems. The implication is that for biomechanical responses below tolerance, there is no injury, and for responses above tolerance, there is injury. An additional factor is biomechanical response scaling for individuals of different size and weight. The commonly accepted procedure involves equal stress and velocity, which enabled Mertz et al. [1989] to predict injury tolerances and biomechanical responses for different size adult dummies. 

The first type of gate is called a rigid gate where all necessary criteria must be passed in order to continue the project. Indeed, it is possible in the case of a rigid gate that the failure to reach even a single threshold could derail a new project. 

A typical single threshold-type aerogel Cherenkov counter (ACC) module looks as shown in Figure 28.12. TMSA tiles are stacked in a thin aluminum box of approximate dimensions 120 x 120 x 120 mm. In order to detect the Cherenkov light effectively, two fine mesh-type PMTs are attached directly to the aerogels at both sides of the box. The inner surface of the box (except for the phototube windows) is lined with a diffuse reflector... 

Several experiments are conducted with the BIT PCB and the results are analyzed. The data acquisition experiment environment is shown in Figure 10. The fixed BIT threshold is determined to be 3.3V, and an open fault is to be injected in the circuit. Table 1 lists several false alarm profiles, and the False Alarm Coverage Rates (FACR) of the BIT using the adaptive threshold and that using the single threshold are also given in Table 1, respectively. 

The analysis was performed, according to the British Standard recommendations, in the single threshold mode, with coincidence correction for, at least, 15 size cI asses. 

Theorem 5 (threshold) Successively thresholding an image at a level a followed by level b where b >= a, is equivalent to a single threshold at level b, ie ... 

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