A potential pitfall with stop-time experiments comes with temporal instability of responses. When a steady-state sustained response is observed with time, then a linear portion of the production of reporter can be found (see Figure 5.15b). However, if there is desensitization or any other process that makes the temporal responsiveness of the system change the area under the curve will not assume the linear character seen with sustained equilibrium reactions. For example, Figure 5.16 shows a case where the production of cyclic AMP with time is transient. Under these circumstances, the area under the curve does not assume linearity. Moreover, if the desensitization is linked to the strength of signal (i.e., becomes more prominent at higher stimulations) the dose-response relationship may be lost. Figure 5.16 shows a stop-time reaction dose-response curve to a temporally stable system and a temporally unstable system where the desensitization is linked to the... [Pg.89]

FIGURE 5.15 Different modes of response measurement, (a) Real time shows the time course of the production of response such as the agonist-stimulated formation of a second messenger in the cytosol, (b) The stop-time mode measures the area under the curve shown in panel A. The reaction is stopped at a designated time (indicated by the dotted lines joining the panels) and the amount of reaction product is measured. It can be seen that in the early stages of the reaction, before a steady state has been attained (i.e., a plateau has not yet been reached in panel A), the area under the curve is curvilinear. Once the rate of product formation has attained a steady state, the stop-time mode takes on a linear character. [Pg.90]

The function of I2g> (T) in the vicinity of the phase transition to centrosymmetric conditions usually has a linear character. Such behavior corresponds to ferroelectrics that undergo type II phase transitions and for which the SHG signal, l2Curie temperature is described by the Curie - Weiss Equation ... [Pg.230]

However, serious difficulties appeared later when efforts were made to attack more general problems not necessarily of the nearly-linear character. In terms of the van der Pol equation this occurs when the parameter is not small. Here the progress was far more difficult and the results less definite moreover there appeared two distinct theories, one of which was formulated by physicists along the lines of the theory of shocks in mechanics, and the other which was analytical and involved the use of the asymptotic expansions (Part IV of this chapter). The latter, however, turned out to be too complicated for practical purposes, and has not been extended sufficiently to be of general usefulness. [Pg.322]

Along with spectroscopic techniques, the presence of — Sn... 0=C in the copolymers studied was confirmed by viscosimetric data 2). /Ns-The dependence of intrinsic viscosity on concentration has a non-linear character, which is probably due to the conformational changew caused by the destruction of... [Pg.123]

Although extremely useful in practice, the Butler-Volmer law is entirely empirical, with no justification of its linear character and no prediction of how the rate constants could be related to the molecular structure of the... [Pg.32]

Another important aspect of the Marcus theory has also been systematically investigated with organic molecules, namely the quadratic, or at least the non-linear, character of the activation-driving force relationship for outer sphere electron transfer. In other words, does the transfer coefficient (symmetry factor) vary with the driving force, i.e. with the electrode... [Pg.17]

In formalism, this is really no different than the classical situation just described, except that the electronic-charge distribution is continuous, as opposed to discretized, and the non-linear character of the equations introduces an iterative component to the SCRF procedure that goes hand in hand with permitting relaxation of the charge distribution. That being the case, the methods used to represent the reaction field are essentially the same as those used in the classical situation. For example, SCRF schemes solving for the reaction field on a three-dimensional grid have been described by both Chen et al. (1994) and Tannor et al. (1994). [Pg.400]

As a conclusion, our experimental/simulation study of the supercritical Ar solvent response, upon a Rydberg transition, reveals a highly non-linear character of the medium reorganisation. Simple model systems, such as the one used here, may provide a working basis for the development of a formal description of the non-linear response in condensed phase media. [Pg.256]

This substitution has only a small effect on the form of kinetic equations in particular, the linear character of the dependence of S0l on PC2h4o/Po2 is preserved. [Pg.237]

From Lemma 12.4.1(h), (iii) and Corollary 9.4.4(h) we know that there exists a linear character st such that, for each element l in L, st(ai) = —1. The linear character st is called the Steinberg character of CS. [Pg.267]

Table 6.2 confirms the highly directional, near-linear character of a-hole bonds the relevant angles are mostly between 170° and 180°. The separations between the interacting atoms are less than or about equal to the sums of the respective van der Waals radii (given in a footnote in the table). [Pg.157]

The names should be linear character strings, to permit lexicographic... [Pg.6]

At this point it should be noted that both conformers of Figure 1 have this essentially 1-dimensional (linear) character. However, when either ... [Pg.19]

The detailed solution of Eqs. (2.2) and (2.3), subject to the given boundary and/or mean-field conditions, represents a formidable problem and has been solved only for a small number N of particles. However, making use of the linear character of the governing equations, much can nonetheless be formally concluded regarding the functional dependence of the solution. In such context, we consider the formalism of Brenner and O Neill (1972) in the following paragraph, albeit with minor modifications. [Pg.8]

The values of a(BET) in Table 9.1 are the BET-nitrogen areas, which were derived from the linear regions of the BET plots, with the molecular area assumed to be 0.162 nm2. The values of a(ext) in Table 9.1 are obviously much smaller than the corresponding values of a(BET). The question naturally arises does the BET method provide a reliable assessment of the total area (i.e. internal plus the external area) The non-linear character of the low-pressure region of each as-pk>t is a clear indication that the isotherm is distorted in the monolayer region and we may therefore conclude that a(BET) does not represent a real surface area. Additional support for this interpretation comes from the microcalorimetric data, which are discussed later in this section. More detailed discussion of some of the results in Table 9.1 is given in Chapter 12. [Pg.257]

If the bubble distribution analysis does not take into account a certain fraction, for example R < Rn, then the linear character of the distribution curves in the logarithmic probability system is sharply disturbed close to the point corresponding to radius R the curves acquire a vertical asymptotic character. [Pg.28]

The temperature dependence of conductivity of poly(thienylpyrrole) is shown in Figure 6. The non-linear character of the conductivity throughout the whole range of temperatures studied here (room temperature to liquid nitrogen) indicates that the conduction mechanism could be different in different temperature... [Pg.563]

The structure of the complex appears to retain its linear character when HF is replaced by HCl, on the basis of SCF computations, coupled with observation of IR and Raman spectra in Ar matrices or IR absorption and microwave spectroscopy in the gas phase. When CO2 is paired with HBr, the geometry loses its H-bond character the H atom approaches the C atom, with the HBr axis perpendicular to (Another recent mi-... [Pg.295]

See also in sourсe #XX -- [ Pg.176 ]

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