Percentage of control

The application of control technology to air pollution problems assumes that a source can be reduced to a predetermined level to meet a regulation or some unknown minimum value. Control technology carmot be applied to an uncontrollable source, such as a volcano, nor can it be expected to control a source completely to reduce emissions to zero. The cost of controlling any given air pollution source is usually an exponential function of the percentage of control and therefore becomes an important consideration in the level of control required (1). Figure 28-1 shows a typical cost curve for control equipment. 

Table I. Helianthus armuus. Growth Inhibition of L. minor. The Effect of the Fractions of Fronds as Percentage of Control after 5 Days Exposure...

David and coworkers (Canada) investigated the effect of ECT on amelanotic melanoma (Tl-4) solid tumors in hamsters.75 The treatment consisted of a passage of currents from 0.1 to 2.4 mA, for lh/day for live consecutive days. Treated tumors decreased in mass (as a percentage of controls) to 89% at 0.1 mA and to 2% at... 

The supernatant was replaced after 3 days of exposure of cells (tumor and normal) to plant extracts and the cells were washed with PBS, then 500 pL MTT solution (0.25 mg/mL) was added to each well. The cells were washed after 3 h of incubation at 37 C, the formazan crystals formed in hving cells solubilized with 1 mL isopropanol, and the absorbance measured at 570 run with a Jasco UV-Vis spectrometer. Cell viability was expressed as a percentage of control treated with different concentrations of plant extracts. 

Figure 6. Proliferation of the murine Myl-D7 stem cell line is stimulated efficiendy only by membrane-bound CSF-1. 2-10 Myl-D7 cells were cultured on MMCE cells expressing the different CSF-1 isoforms in 48-well plates. Cloning efficiencies were determined weekly and Myl-D7 clones (>10 cells) were transferred onto new MMCE cells. Values of Myl-D7/MS5 cocultures were set to 100% at each time point (data not shown). Results are expresses as percentage of control Myl-D7/MS5 cultures and are mean values +SD (four experiments). After 3 weeks in coculture a) no difference was found in the proliferation rates of cells stimulated by either wildtype- or soluble CSF-1 (P>.05) b) mean values for populations stimulated by membrane-bound- or soluble CSF-1 were significantly different (P<.001).

Percent prolongation of life, except for figures in parentheses which represent percentages of control tumor growth (data from Ref. 14). 

Fig. 6.6 Effect of beta blockers on post-infarction mortality. Etifference in mortality rates is expressed as a percentage of control rate in six controlled trials of beta blockers (95% confidence intervals based on odds ratio consideration). Narrow confidence intervals are associated with the largest trials that are the major contributors to the pooled result.

Table I. Alkyl Pyrazines Thermally Generated in Matrix with Soy Proteins (Percentage of Control)...

Fig. 4. Agonist dependence of desensitization of 5-HT2C receptor-mediated IP accumulation and AA release. Cells were pretreated for 0-60 min with maximal concentrations (at least 20X KA) of the agonists 5-HT (10 xM), quipazine (30 pM), LSD (100 nM), TFMPP (10 xM), m-CPP (20 M) or bufotenin (10 pM), washed, and AA release and IP accumulation measured in response to 10 pA/ 5-HT for 10 min. AA release and IP accumulation were measured simultaneously, from the same cells. Data are expressed as a percentage of control 5-HT stimulation and are reproduced from ref. 85 with permission.

Table 8. Inhibition of incorporation of (6- C) -D-glucose into chitin fractions of Pieris brassicae larvae by diflubenzuron and polyoxin D, as percentage of controls.

Benzene also affects functional immune responses, as indicated by decreased resistance to infectious agents. Pre-exposure to benzene at >30 ppm for 5-12 days increased the bacterial counts in mice on day 4 of infection with Listeria monocytogenes (Rosenthal and Snyder 1985). Recovery of the immune system was noted on day 7. The effects did not occur at 10 ppm. In addition, a concentration-dependent statistically significant depression was noted in T- and B-lymphocyte populations from day 1 through day 7 at 30 ppm and above. B-cells were more sensitive to benzene than were T-cells on a percentage-of-control basis. This indicates a benzene-induced delay in immune response to L. monocytogenes. Concentrations of 200 or 400 ppm for 4-5 weeks (5 days per week) suppressed the primary antibody response to tetanus toxin in mice, but there was no effect at 50 ppm (Stoner et al. 1981). In another intermediate-duration exposure study, no changes were noted in the numbers of splenic B-cells, T-cells, or... 

Express the minimal antiviral inhibitory concentration as the IC50, or the concentration required to inhibit virus-induced CPE or plaque formation by 50%. IC50s are estimated from (semilogarithmic) graphic plots of the number of plaques (percentage of control) or percentage of CPE as a function of the concentration of the test compound. 

In chronic studies, the data often are expressed as a percentage of control, although this is certainly not necessary. Hatchability, percentage weight gain,... 

Fig. 8. Fabric breaking strengths and abrasion data expressed as percentages of control in relation to nitrogen content. P = pad-dry-cure M mi Id-cure S steam-cure (47) ...

Figure. 1. Effect of tetrodotoxin (left) and Mn2+ (right) on stimulated Ca uptake by rat brain synaptosomes. Uptake of 45Ca was stimulated by exposing synaptosomal suspensions to 5 /zM veratridine (9) for 5 min or to 64 mM K+ (O) for 15 s in the absence or presence of the indicated concentrations of tetrodotoxin or MnCl2. Values are expressed as percentage of control (absence of tetrodotoxin and Mn) stimulation (4.1 0.7 fjjnol Ca accumulated/g prot). Each point and vertical line represents the mean and SEM, respectively, of triplicate samples.

IgG , preimmune rabbit serum IgG IgGj, anti-SCP2 rabbit serum IgG. The IgG fractions contained 160 fig protein. Immunotitrations and mitochondrial incubations were conducted as described [30], Results are expressed as percentage of control S.E. 

FIG. 4. (A) Representative iinmunoblois of lysate.s from cortical neurons exposed to chlorpyrifos (CPF)-OxOn for 1 hr using antibodies that recognize pCREB (top) or de-tubulin (bottom). (B) Mem optical density of bands from immunohlois of ly.sates from cortical neurons exposed to CPF-oxon (0-10 nM) for I hr probed with pCREB or a-tubulin. Data are expressed as a percentage of control values on each gel. (C) Mean optical densities from additional studies widi lower doses of CPF-oxon (O-lOpM) indicating that the concentration of CPF that elicits half-maximal response (EC50) is below 30 fM. Each bar or point is the mean of 5-17 cultures error bars arc SEM Adapted from Schuh et al. (2002). 

Valiies expressed as percentage of control. Means of four experiments with ten seeds each. 

The values are expressed as a percentage of control s radial diameter obtained 3 to 12 days (depending on species) following inoculation with a Sima plug. A - P. cactorum without added cholesterol, B - P. cactorum with added cholesterol, C -Gibberella fujikuroi. D - Saproleania ferax. E - Achlya bisexualis, male strain, P - Achlva bisexualis. female strain. 

Inhibition type u (velocity) Percentage of Control Relationship (IC50 and Ki) ([S] = Km)... 

Methyl oleate concentration (mAf) Lipid uptake (nmol/mg protein) Rate of Ca uptake (percentage of control)"... 

Fig. 2. Hepatocyte phospholipid fatty acid changes in rats fed an eicosapentaenoic acid (EPAVy-linolenic acid (CLA) diet. Results are means SEM, n = 7, and are expressed as a percentage of control.

Figure 1. Effect of thia fatty acids on nit plasma cholesterol. The values represent the mean iSD for lour animals in each experimental group. Measurements perlbrmed in rat F.DTA plasma. All values given as percentage of control (CMC). The rats were treated with a dose of i SO or 34X)ing/d/Kg body mass for 7 days...

---