Fractional population

Sensitometric tests at variable light intensity I under conditions of photography, achieved on emulsions doped at the relative concentration of 10 mol HCO2 per mol Ag, confirmed the photo-induced bielectronic transfer (Fig. 15, bottom) [200]. The emulsion is completely stable in the dark. The number of photons required to induce development of the same grain population fraction is 5 times less (after immediate development) or 10 times less (development delayed by 20 min after exposure) in doped than in undoped emulsions where < eff=0.20. The quantum yield is thus close to the theoretical limit atom/photon in immediately developed doped emulsion (7 = 0),... 

In general, different population fractions have different propagation speeds. An interesting particular case is that for which the replication and disappearance rate coefficients... 

And the population fraction of higher energy levels at T = 275 K is obtained from the following expression ... 

We have recently developed a quasi-species approach for analyzing mutation and selection in catalytic reactions of varying order. We discussed how the error catastrophe that reflects the transition from localized to delocalized quasi-species population is affected by catalytic replication of different reaction orders. Specifically, the second-order mechanisms lead to a discontinuity in the mean fimess of the popnlation at the error threshold. This is in contrast to the behavior of the first-order, antocatalytic replication mechanism, considered in the standard quasi-species model. This suggested that quasi-species models with higher order of replication mechanisms produce discontinuities in the mean fitness and, hence, in the viable population fraction, at the error threshold, while lower-order replication mechanisms yield a continuous mean fitness fnnction. 

Two different tests can be applied to check whether the denaturation of a given protein can be described with the two-state transition model, namely, the population test and the Vant Hoff test. The population fractions of native and denatured state, fN(/) and fi)(7), are independently evaluated [154,184] (see Figure A3) ... 

Figure A3. Population fraction test in the case of (a) RNase A (one step denaturation), and (b) RNase BS (more complex behaviour).

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