Indirect population

Since the combination band anharmonicity (<10 cm 1) (84) is less than our spectral resolution ( 60 cm-1 in this measurement), excitation of the combination C-C stretch and C=N stretch is seen as excitation of both fundamentals (44). Pumping the combination band causes an instantaneous jump in the populations of the C-H stretch, C-C stretch, and C=N stretch. The directly pumped C=N stretch excitation rises to a level about 20 times greater than when it is indirectly populated with C-H stretch pumping. A C=N stretch and a C-C stretch on the same molecule can annihilate each other via cubic anharmonic coupling to create C-H stretch excitations (47). 

The quantum yield, O, for an excited state process is given by the ratio of the rate constants for the process of interest, divided by the sum of all the rate constants for the deactivation of a state for a directly populated state. For an indirectly populated state, this ratio is multiplied by the fraction of light that populates this state, Eq. (12). For emission from the MLCT state of [Ru(bpy)3] " in the absence of a quencher, is ... 

In situations where conserved internal markers caimot be used, such as in spills of essentially pure compounds, the evidence for enhanced biodegradation may have to be more indirect. Oxygen consumption, increases in microbial activity or population, and carbon dioxide evolution have all been used with success. 

Fig. 2. Electron drift velocities as a function of electric field for A, GaAs and B, Si The gradual saturation of curve B is characteristic of all indirect semiconductors. Curve A is characteristic of direct gap semiconductors and at low electric fields this curve has a steeper slope which reflects the larger electron mobiUty. The peak in curve A is the point at which a substantial fraction of the electrons have gained sufficient energy to populate the indirect L minimum which has a much larger electron-effective mass than the F minimum. Above 30 kV/cm (not shown) the drift velocity in Si exceeds that in...

An even simpler and perhaps more effective approach to the problem might be application of the resazurin test as applied in the milk industry for indirect estimation of bacterial population. Proctor and Greenlie (34) have suggested this application, and Wolford (38) has worked with it in a limited way. The test is based upon a color change involved in the reduction of the dye. The time required for reduction decreases with increase in bacterial numbers. Intensive investigation of this method and its application with respect to increasing its sensitivity, and correlation of reaction rates with bacterial population and quality characteristics of the product, might be of considerable value. 

A substantial amount of indirect evidence supports the contention that the induction of apoptosis in tumor cells is critical to successful therapy. Cancer therapy might therefore be viewed as an attempt to induce apoptosis in a population of cells that have undergone selection for apoptotic defects. If correct, this hypothesis would suggest why cancer therapy is in many cases unsuccessful. However, recent studies indicate that this fundamental problem can be circumvented. Progress in the identification of molecules key to the cell death pathways has led to a growing understanding of how apoptosis occurs [3]. It has become clear that pathways to apoptosis are numerous and often interconnected. A solution to the clinical problem of therapeutic resistance, then, may lie in the fact that there appears to be multiple ways that a cell death program can be implemented. 

Administrative representatives are often shy about developing water reuse projects. Evaluations of the risks related to water reuse have been twisted so as to be employed in political arguments during election campaigns, which may explain the reluctance of politicians. Examples of failure and success of indirect potable reuse projects in the United States are provided by [13]. Such experiences point out the importance of public education as regards the human interaction with the water cycle and the management of water resources. The population should be aware that... 

Hanvelt et al. (1994) estimated the nationwide indirect costs of mortality due to HIV/AIDS in Canada. A descriptive, population-based economic evaluation study was conducted. Data from Statistics Canada were used, which contained information about aU men aged 25-64 years for whom HIV/AIDS or another selected disease was listed as the underlying cause of death from 1987 to 1991. Based on the human capital approach, the present value of future earnings lost for men was calculated. The estimated total loss from 1987 to 1991 was US 2.11 billion, with an average cost of US 558,000 per death associated with HIV/AIDS. Future production loss due to HIV/AIDS was more than double during the period 1987 to 1991, from US 0.27 to US 0.60 billion. A more comprehensive update of this smdy was presented by Hanvelt et al. (1996). The same database and the same data section but for the calendar years 1987-1993 was used. The indirect cost of future production due to HIV/AIDS in Canada based on the human capital approach for that period was estimated to be US 3.28 billion. The authors also calculated the willingness-to-pay to prevent premature death due to HIV/AIDS, which was estimated based on... 

Broadly speaking, the direct behavioral effects of neurotoxic pollutants on wild animals may be on feeding, breeding, or avoidance of predation (Beitinger 1990), or any combination of these. Any of these changes may have adverse effects on populations. Additionally, in the natural world, populations may be affected indirectly because of neurotoxic and behavioral effects on other species. Thus, a population decline of one species due to a behavioral effect of a pollutant may lead to a consequent decline of its parasites or predators, even though they are not themselves directly affected by the chemical. Direct effects will now be discussed before considering indirect ones. 

Transfer of polarization from C nuclei to H nuclei and their subsequent detection leads to a 16-fold increase in sensitivity because the C magnetization is being measured indirectly through detecting it via the nucleus with the higher magnetogyric ratio (i.e., H). Irradiation of the protons between the scans causes a further threefold increase in the population of the C nuclei due to nOe, so an overall 50-fold increase in sensitivity is achievable in contrast to direct C measurements. However, because of... 

Three-spin effects arise when the nonequilibrium population of an enhanced spin itself acts to disturb the equilibrium of other spins nearby. For example, in a three-spin system, saturation of spin A alters the population of spin B from its equilibrium value by cross-relaxation with A. This change in turn disturbs the whole balance of relaxation at B, including its cross-relaxation with C, so that its population disturbance is ultimately transmitted also to C. This is the basic mechanism of indirect nOe, or the three-spin effect. 

---