Qualitative interaction

Fig. 6. Qualitative interaction diagram, aromatic ketone and electron-rich olefin...

The solvent Stark term developed by Baur and Nicols 9) reflects the same qualitative interactions as the reaction field term, however, it concerns the situation when the solute is less polar (in the ideal case non-polar) than the surrounding solvent. Correlations with Stark effects are usually recognized as linear relations to the term... 

ICH makes the distinction between quantitative and qualitative interactions. A quantitative interaction refers to the situation where the treatment difference is consistently in one direction (for example A is always better than B), but there are differences in terms of magnitude. A qualitative interaction is where the treatment difference is in a different direction for some centres (for example A is better than B in some centres but B is better than A in other centres). The previous example is an example of a quantitative interaction. Had the A mean in centre 4 been 3.9 and the B mean 5.0, then the treatment difference (A — B) would equal —1.1 and we would have a qualitative interaction. 

Figure 13.8 Qualitative interaction between punch design and compression force...

If what we saw in Figure 13.7 was quantitative interaction , then Figure 13.8 may be said to show qualitative interaction . 

Figure 25.3 Center by treatment interaction qualitative interaction...

Although it would seem at first that only qualitative interaction information could be obtained from such screens, in fact, under certain conditions, data obtained could be semiquantitative. For example, one need only determine equilibrium concentrations of interacting species to find the equilibrium constant [see equation (1)]. If the transcription rate for the plasmids used could be determined from FP expression from the plasmid, for instance, and if the transcription rate... 

In Fig, 31 we derive the valence MO s of cubane in a qualitative interaction diagram On the left, twelve degenerate C-C localized MO s interact to yield the five CC energy levels of t u, tjg, Cg, ti and aig symmetry. On the right of Fig. 30, eight... 

Even a type III trial, however, will not provide adequate power to test differences in response to treatment of men and women. There are two reasons. First, we may expect that the difference in the treatment effect between one sex and another will be smaller than the larger of the two effects. (If this were not the case it would imply that the treatment was harmful for one sex and beneficial for another a so-called qualitative interaction.) Second, such interactive contrasts, have, in any case (other things being equal) higher variances. Thus a type IV trial will require even greater numbers of patients and recruitment times. 

A.2 The maximum possible difference in the treatment effects in the absence of qualitative interactions... 

Let the treatment effect for females be Tf and that for males be The difference is 8 = Xf - T. Suppose that there are no qualitative interactions and (without loss of generality) that Xj > 0 and x > 0. Suppose now that X > x, . Then, for given X the maximum value of 8 is attained when x , = 0, at which point it equals Xf. Suppose now that x > Xj, then similarly we may show that the maximum possible value of 8 is x j. Thus, in the absence of qualitative interactions, the difference in effects cannot be greater than the greater of the two effects. 

Karasz and McKnight (1977) have developed a model based on segmental interaction parameters in copolymers to quantify these qualitative interactions. Each segment in a copolymer conriibutes to both a configurational and an enthalpic term due to chemical interaction. A pair of copolymers can be miscible or immiscible, or a single polymer can act as a compatibilizer, or an immiscible blend polymer can act as a compatibilizer. Paul and Barlow have shown that A H may be negative in a blend due to dilution of more unfavorable interactions, where at least one component in the blend is a copolymer (Paul and Barlow, 1980). 

Gail M, Simon R. Testing for qualitative interactions between treatment effects and patient subsets. Biometrics, 41(2) 361-372,1985. 

More often than not, kinetic or other rate parameters are unknown in GRNs. Only the qualitative interactions between species are usually known, e.g., X activates Y or V inhibits W. As mentioned earlier, we can interpret the meaning of these qualitative interactions as follows S(dY/dt)/0X > 0 and 0(dW/dt)/0V < 0, respectively. A qualitative network can be defined as a set of nodes (species) and a set of qualitative interactions ( activation and... 

Equations (l)-(3) provide a connection between interfacial fluctuations, the surface tension, and intermolecular interactions (expressed by forces). Qualitatively, interactions of water with molecules of the organic liquid increase interfacial fluctuations and reduce the surface tension, compared with the liquid-vapor interface of water. For example, the surface tension of water at 7 = 298 K is 0.0727 N m whereas the surface tension at water-hexane and water-octanol at the same temperature is 0.051 and 0.0085 N m respectively. 

Tobolsky [10] observed that the slope of the relaxation curve, n, appears to be related to the relative stiffness of the polymer chain. This would indicate a qualitative interaction between the chain stiffness index Ng and n on the matrix. It became apparent after examining the literature that no quantitative assessment of this interaction has been presented, although the data available from several sources could be combined for such a purpose. 

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