Cultural pressures

Another variable responsive to cultural pressures is maternal age. Fetal development is not independent of maternal age during pregnancy. Culture is the essential determinant of how women view the proper age range for bearing children. In the European Union between 1980 and 1993 the mean maternal age at first birth rose to 28.6 years. Between 1991 and 2001 in the United States, the percentage of women 35 to 39 years having first births increased by 36 percent, and for women 40 to 44 years by 70 percent.29... 

An engineer lacking a strong ethical value system that could offset cultural pressure within her/his firm and/or external political-economic pressure to engage in ethically questionable engineering practices. 

Many factors affect the mechanisms and kinetics of sorption and transport processes. For instance, differences in the chemical stmcture and properties, ie, ionizahility, solubiUty in water, vapor pressure, and polarity, between pesticides affect their behavior in the environment through effects on sorption and transport processes. Differences in soil properties, ie, pH and percentage of organic carbon and clay contents, and soil conditions, ie, moisture content and landscape position climatic conditions, ie, temperature, precipitation, and radiation and cultural practices, ie, crop and tillage, can all modify the behavior of the pesticide in soils. Persistence of a pesticide in soil is a consequence of a complex interaction of processes. Because the persistence of a pesticide can govern its availabiUty and efficacy for pest control, as weU as its potential for adverse environmental impacts, knowledge of the basic processes is necessary if the benefits of the pesticide ate to be maximized. 

Sucrose is often used as a decorative agent to impart a pleasing appearance to baked goods and confections (36). In jams and jeUies, sugar raises osmotic pressure and lowers water activity to prevent spoilage (18). Sucrose is a fermentation substrate for lactic acid in cultured buttermilk (40) and lowers the freezing point of ice cream and other frozen desserts to improve product mouthfeel and texture. 

A hybridoma can live indefinitely in a growth medium that includes salts, glucose, glutamine, certain amino acids, and bovine serum that provides essential components that have not been identified. Serum is expensive, and its cost largely determines the economic feasibihty of a particular ciilture system. Only recently have substitutes or partial replacements for serum been found. Antibiotics are often included to prevent infection of the culture. The pH, temperature and dissolved oxygen, and carbon dioxide concentration must be closely controlled. The salt determines the osmotic pressure to preserve the integrity of the fragile cell. 

Except as an index of respiration, carbon dioxide is seldom considered in fermentations but plays important roles. Its participation in carbonate equilibria affects pH removal of carbon dioxide by photosynthesis can force the pH above 10 in dense, well-illuminated algal cultures. Several biochemical reactions involve carbon dioxide, so their kinetics and equilibrium concentrations are dependent on gas concentrations, and metabolic rates of associated reactions may also change. Attempts to increase oxygen transfer rates by elevating pressure to get more driving force sometimes encounter poor process performance that might oe attributed to excessive dissolved carbon dioxide. 

The culture broth is sterilized by heating it under pressure at about 120°C for about 30 minutes. The broth is cooled and the above inoculant culture is added aseptically. The organism is grown in the broth for 4 days at a temperature of 26°C. During the growth period the broth is stirred and sterile air is blown through the broth at a rate of about 0.5 volume of air per volume of broth per minute. At the end of the growth period the broth shows an antibiotic activity equivalent to about 150 meg of erythromycin per ml of broth. 

Into each of 27 Erlenmeyer flasks are placed 150 mg of Kendall s Compound F (hydrocortisone). The flasks and contents are then sterilized for 15 minutes at 15 pounds steam pressure (120 C). To each flask are then added 5.0 ml of ethanol. The 24-hour bacterial culture is then transferred asepticaliy and the resulting suspensions are Shaken on a shake table at 220 rpm and 28°C for 48 hours. The pH at the end of the shake period is 7.0. 

The fungus isolated from the wastewater was used as a seed culture. The media for seed culture as a starter of each experimental run was prepared by using 1.0 g of glucose and 1.0 g of peptone in 100 ml of distilled water. The nutrients and minerals were obtained from Merck. The media was sterilised in an autoclave at 121 °C, 15 psig steam pressure for 20 minutes. 

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