Adapting, to change

Overall, use of learning systems has two main advantages. First, the construction cost may be lower, certainly if the system is not construeted from scratch but uses existing software tools and components. Second, a learning system is able to adapt to changing conditions, though not always on-line. 

On the other hand it is well known that the hnman eye can adapt to changing inspection conditions in recognizing flaws while a camera system is not able to adapt automatically. 

Concomitantly with the increase in hardware capabilities, better software techniques will have to be developed. It will pay us to continue to learn how nature tackles problems. Artificial neural networks are a far cry away from the capabilities of the human brain. There is a lot of room left from the information processing of the human brain in order to develop more powerful artificial neural networks. Nature has developed over millions of years efficient optimization methods for adapting to changes in the environment. The development of evolutionary and genetic algorithms will continue. 

Neurotransmitter receptors have evolved as one of the key components in the ability of the central nervous system to coordinate the behaviour of the whole animal, to process and respond to sensory input, and to adapt to change in the environment. These same receptors are therefore ideal targets for drug action because of their central role in the activity of the nervous system. A rational approach to the development of new therapeutic strategies involving the action of drugs at receptors in the nervous system is based on knowledge of receptor structure, distribution and function. 

All living organisms have two primary objectives to maintain their vital functions and to relay their genetic information by reproduction. To exercise this task successfully a creature has to react flexibly upon its environment. It has to escape from enemies, it has to adapt to changes in temperatures like heat or... 

All these transport processes are of comparable importance for an organism in order to adapt to changing conditions and to exist in a given environment. This book focuses on the mass transfer aspects across biomembranes, involving ions, molecules, and particles. 

This knowledge ensures that a high standard of quality of the commercial products is maintained and that polystyrene can continue to adapt to changing economic situations and new applications. 

The SSP plant for repelletized PET is similar to a virgin SSP plant. It is usually smaller, because of smaller feed stock availability, and should provide the flexibility to adapt to changing product requirements. Another difference results from the IV increase rate of recycled PET, which tends to be lower. This is attributed to a lower activity of the transesterification catalyst in recycled PET. 

Natural proteins have been selected not only to fold into stable structures, but to do so under various conditions and in reasonable time. More obviously, they have been selected for particular functions that often require hydrophobic surface groups and nonregular secondary structures. Finally, most extant proteins have been indirectly selected to be insensitive to most mutations. We note that those early proteins that could not accept numerous mutations without loss of function or structure would not adapt to changing conditions or functional requirements. All of these factors mean that natural proteins are unlikely to fit any single optimization concept. 

A very small percentage of all mutations actually have a positive effect. These mutations lead to new versions of proteins that help an organism and its future generations better adapt to changes in their environment. For example, a beneficial mutation could result in a protein that protects the organism from a new strain of bacteria. 

Learning metabolism requires a step back to focus, initially at least, not on the minute details but on the biological purpose(s) of a pathway. Look for patterns and similarities between pathways and always ask the questions what does this pathway do for meV and how does this pathway adapt to changing physiological situations Be an active learner and make it personal ... 

The transition from rest to mild activity and then to strenuous activity provides us with a good example of metabolism adapting to changes in the physiological situation. Exercise-related biochemistry is a major subject of research and a detailed description is beyond the scope of this text and the interested reader is referred to a specialized source. A brief overview is given below. 

Prokaryotes have the capacity to rapidly adapt to changes in their chemical environment. Proteins needed for growth are normally synthesized at levels sufficient to support maximal growth rate on a given substrate. In Nature, however, the cells are usually exposed to a mixture of nutrients, and complex regulatory networks guarantee a hierarchical utilization of the substrates, guided by metabolic efficiency. 

In the course of phylogeny an efficient control system evolved that enabled the functions of individual organs to be orchestrated in increasingly complex life forms and permitted rapid adaptation to changing environmental conditions. 

Enzymes are biological catalysts—i. e substances of biological origin that accelerate chemical reactions (see p. 24). The orderly course of metabolic processes is only possible because each cell is equipped with its own genetically determined set of enzymes. It is only this that allows coordinated sequences of reactions (metabolic pathways see p. 112). Enzymes are also involved in many regulatory mechanisms that allow the metabolism to adapt to changing conditions (see p.ll4). Almost all enzymes are proteins. However, there are also catalytically active ribonucleic acids, the ribozymes" (see pp. 246, 252). 

---