Feeding history

Head, E.J.H., and Harris, L.R. (1996) Chlorophyll destruction by Calanus grazing on phytoplankton kinetic effects of ingestion rate and feeding history, and a mechanistic interpretation. Mar. Ecol. Prog. Ser. 135, 223-235. 

When the system follows Langmuir competitive equilibrium behavior, the coherence condition defines a grid of coherent composition paths to which the system is restricted once the coherence condition is satisfied. Knowing the feed history, i.e., the boxmdary condition, one can use this grid, find the composition routes for the column and predict the column effluent history. 

The effluent concentration history is the breakthrough curve, also shown in Fig. 16-3. The effluent concentration stays at or near zero or a low residual concentration until the transition reaches the column outlet. The effluent concentration then rises until it becomes unacceptable, this time being called the breakthrough time. The feed step must stop and, for a regenerative system, the regeneration step begins. 

In this chapter, by using the examples of -lactams we have briefly examined how microbial cultures may be used to produce sufficient antibiotics to meet market demands. We have also explained how enzymes (or cells) may be used to biotransform, and thereby diversify, antibiotics. By outlining the history of penicillin production, we explained how analysis and manipulation of culture regimes may be used to enhance the yields of antibiotics (and other secondary products). These studies led to die concept of directed biosynthesis by precursor feeding. 

Anticoagulants History of local radiotherapy History of Keloid formation Pregnancy/breast-feeding Heavy smokers... 

As explained in Chapter 1, the toxicity of natural xenobiotics has exerted a selection pressure upon living organisms since very early in evolutionary history. There is abundant evidence of compounds produced by plants and animals that are toxic to species other than their own and which are nsed as chemical warfare agents (Chapter 1). Also, as we have seen, wild animals can develop resistance mechanisms to the toxic componnds prodnced by plants. In Anstralia, for example, some marsupials have developed resistance to natnrally occnrring toxins produced by the plants upon which they feed (see Chapter 1, Section 1.2.2). 

PCDD/PCDFs accumulate in human adipose tissue, and the level reflects the history of intake by the individual. Several factors have been shown to affect adipose tissue concentrations/body burdens, notably age, the number of children and period of breastfeeding, and dietary habits. Breast-milk represents the most useful matrix for evaluating time trends of dioxins and many other POPs. Several factors affect the PCDD/PCDFs content of human breast-milk, most notably the mothers age, the duration of breast-feeding and the fat content of the milk. Studies should therefore ideally... 

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