Growth curve studies

For growth studies, 10 cells/ml (optical density A = 0.1) culture of Candida cells were inoculated and grown aerobically in YPD broth for control along with varied concentrations of test materials in individual flasks. Growth was recorded turbidometrically at 595 nm using Labomed Inc. Spectrophotometer (USA) as reported previously [62]. The growth rate study of different Candida species in absence as well as in presence of inhibitor was performed for each concentration in triplicate, average of which was taken into consideration. 

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The focus on productivity in growing systems requires a time component in the study of ecosystem responses. The response of productivity to stress must therefore be considered in three dimensions (Fig. 6). This figure illustrates the effects of a stress at any particular time on the classic sigmoid curve of growth (productivity). Positive production will occur only if the stress is less than the ultimate stress and the residual strain (permanent productivity reduction) will be seen as a lowering of the growth curve below the upper boundary (the z dimension in Fig. 6). 

Maeda, K., Murao, F., Yoshiga, T., Yamauchi, C., and Tsuzaki, T. (1986). Experimental studies on the suppression of cultured cell growth curves after irradiation with CW and pulsed ultrasound. IEEE Trans. UFFC 33,186-93. [173]... 

In order to study the virus growth curve a one-step growth cycle is performed. A high multiplicity of infection (m.o.i.) is used to ensure every cell is infected — usually 10 plaque forming units (p.f.u.) per cell is adequate. For virus production, however, the infection is prolonged under conditions where secondary infection can occur and a low m.o.i. is recommended especially where there is a tendency for defective virus particles to be produced. 

We happened to belong to this category, but just the same we did look at our tubes before they were ready for analysis—the reason being that we were unhappy about the lack of linearity of the responses. The response curves varied, not so much from one experiment to another, but strangely from one amino acid to another. This is how we came to study the growth curves. 

Benzene. The unreactive benzene-NOa. system was also studied in the presence and absence of CO. When 5 ppm benzene and 4.5 ppm NOa, were irradiated in the absence of CO, only about 1% of the benzene reacted in seven hours. The curve for the growth of NO2 was the same as that shown in Figure 1 for irradiating NO in the absence of hydrocarbons. When benzene and NO were irradiated with 2,000 ppm CO, about 5% of the benzene reacted after 7 hours, and there was some increase in the oxidation rate of NO. However the NO2 growth curve was almost identical to the one shown in Figure 1 for irradiating NO. in the presence of 2,000 ppm CO. These results suggest that benzene affected the oxidation rate of NO very little. 

The study of tumor growth forms the foundation for many of the basic principles of modem cancer chemotherapy. The growth of most tumors is illustrated by the Gompertzian tumor growth curve (Fig. 124-5). Gompertz was a German insurance actuary who described the relationship between age and expected death. This mathematical model also approximates tumor-cell proliferation. In the... 

FIGURE 4.8 Crustal growth curves based upon transport-balance modeling (Nagler Si Kramers, 1998), U-Pb zircon ages from juvenile crust (Condie, 2000) and Nb/U ratios for the depleted mantle (Collerson Si Kamber, 1999). The Nagler and Kramers model assumes either 0% crust at 4.4 Ga (A) or 10% crust at 4.4 Ga (B), and their calculations are consistent with Pb isotope modeling and Hf-isotope studies. 

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