Defining Tolerance

2 Proximate Mechanisms of Herbivore Tolerance 10.2.1 Defining Tolerance  

When confronted with chemically rich seaweeds in their local communities, some herbivores have evolved a means to detect and avoid these foods. These feeding avoidance behaviors are probably mediated by taste, rather than smell, because 

If feeding behaviors, assimilation efficiency, or fitness are reasonable proxies for tolerance of secondary metabolites, then it is clear that herbivore individuals, populations, and species profoundly vary in their tolerance (Paul et al. 2001 Stachowicz 2001 Targett and Arnold 2001). Such differential tolerance was recognized early within the emerging field of marine plant-herbivore interactions (Hay 1992 Hay and Steinberg 1992 Paul 1992), much to the dismay of these scholars. The same metabolite may show considerable difference in its effects even on closely related species of herbivores (Paul 1992). 

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Figure 13.2 A typical Catalyst pharmacophore, where different colors indicate different chemical features and the spheres define tolerance spaces that each chemical feature would be allowed to occupy. See color plate.

For each NOESY cross peak, one or several initial assignments are determined based on chemical shift fitting within a user-defined tolerance range. 

In the last few years, a number of factors have led practitioners to abandon the concept of ultraclean processing (reducing the level of contaminants to below the level detectable with state-of-the-art equipment). The approach that seems to have taken hold instead is that of just clean enough, which requires a fundamental understanding of the specific effects of contaminants and as a consequence, the ability to define tolerable levels of contaminants. In the next section we review the characterization tools that can be used in this context. 

The linear range of a detector is defined as the range of concentration over which the sensitivity is constant to within a defined tolerance. S is obtained by performing a linear regression analysis of the data. A simple way to determine the linear portion is to draw a second line having a slope equal to 95% of that of the best-fit line. It intersects the response curve and determines the Unear range (Fig. 17). 

Linear range is the range of concentrations over which the sensitivity (5) is constant to within a defined tolerance (Figure 4.1). 

The root-mean-square of the forces must be essentially 0 (below the defined tolerance of 0.0003). 

Control of temperature and relative humidity, if necessary, within defined tolerances and, if possible, monitored continuously. 

Quahty is always defined by customer satisfaction. The customers decide what characteristics they want the product to have. A tire manufacturer, for example, could teU the rubber manufacturer that he will only buy his product if its viscosity is 45. This is the nominal specification value. However, since it is not realistic to expect that all the batches have exactly this value, the tire manufacturer, in practice, accepts a variation in the viscosity value of, say, three units. These values define tolerance limits for the viscosity specification no less than 42, and no more than 48. 

Creates optimized tool paths according to user-defined tolerances... 

Like most general methods for assessing structural similarity, XPac dispenses with traditional descriptions of unit cells and space groups by considering the environments of molecules [55, 56]. A reference molecule (referred to as the kernel molecule) is defined, and a coordination shell is generated on the basis of some distance criterion. A molecule is considered to form part of the coordination shell if it forms at least one contact to the kernel molecule in which the interatomic distance is less than the sum of the van der Waals radii plus some defined tolerance. The tolerance is usually set to a value of 1.5 A, which is liberal in the context of conventional views of what constitutes a significant intermolecular interaction. The kernel molecule and all associated shell molecules form... 

Note that the sharpness of the transition in the change on going from the depletion zone to the parabolic zone is due to limitations in the analytical function and does not reflect real transition behaviour. The more gentle transitions indicated in the theoretical SCF profile are more realistic. In the self-consistent field calculation a lattice model is not presumed the volume fraction of the tethered chains is calculated from a diffusion equation that involves polymer propagators and a (z-dependent) potential function that includes enthalpic interactions between the two copolymer blocks and between each block and the solvent. Initially the potential function is set to zero, the pol)nner propagators are calculated and then the volume fraction variation of the tethered block. A new potential is calculated from this volume fraction profile and the process reiterated imtil the difference in volume fraction profiles calculated by sequential iterations is smaller than some defined tolerance. The approach bears similarities to the SCF approach of Shull (1991) but makes no allowance for the dry brush case, i.e. that in which the relative molecular mass of the solvent approaches that of the tethered polymer molecule. 

With regard to metabolic stability bioisosteric replacements, that is, substituents that are interchangeable with minimal effect on metabolism, one could look at the most neutral transformations, that is, the ones that did not result in a favorable or unfavorable effect on metabolic stability, at least within the defined tolerance threshold of 25%. The substituents of these transformations are therefore, by definition, isosteres. The 12 most neutral transformations in terms of the percentage of examples that led to no significant change are listed in Table 6.4. 

The process of defining tolerable risk, confirming existing risk (both likelihood and consequence), and assigning a Safety Integrity Level (SIL)-rated safety function as needed to achieve a tolerable level of risk. See also Safety Integrity Level (SIL). 

High-pressure hydraulic pumps contain components that are made to closely defined tolerances. For this reason it is very important that the oil that is used within the system is clean. Contamination of the oil, down to particles too small to be seen by the human eye, leads to erosive wear of the pump and a gradual loss of system pressure. It is well worth ensuring that oil maintenance is given a high priority and that sub-standard oils are not used. 

Figure Al. The lowest level hierarchical structure for most quantum mechanical computational algorithms. The inner loop is used to converge the self-consistent field in order to establish the electronic structure to within a user-defined tolerance. The outer loop is used to optimize the structure to within a defined geometric tolerance.

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