Rational learning

Materials selection is as much an art as a rigorous science, and another computational approach to it, based on ideas of artificial intelligence, has been proposed by Arunachalam and Bhaskar (1999). They call their approach bounded rationality and exploit it to analyse the background to some notorious disasters based on material failure. We can always learn from failure as well as from success. 

My interest in the periodic table has at least two aspects. Firstly, like so many people before me, I fell in love with the rational beauty of the periodic chart that appears to systematize all the kinds of elementary substances that a student of chemistry would ever encounter.1 The extent to which students are exposed to the periodic table and the stage at which this takes place seems to vary a good deal depending on geographical location and on the era in which they learn chemistry. In my own case it was in London in the 1960s where we were not initially taught the periodic table, although it was displayed on the classroom walls. 

Learning the chemistry that enables a person to become a more informed citizen for example, to be able to discuss the use of sustainable energy sottrces in a rational way ... 

Michelspacher s title-page is not, in fact, a monument to empirical learning, but takes the form of a memento mori. Far from applauding the new Renaissance humanism, on the contrary, he employs the science of anatomy as a metaphor to demonstrate the futility of rational knowledge in the face of death and decay.The prospect of immortality is available only to those who seek an intuitive Gnosis, a divine epiphany concerning God s work in Nature. 

Although impressive progress has been made in unraveling the mechanism of ORR catalysis by cofacial porphyrins, much remains to be learned before we can understand how this mechanism relates to those in heme enzymes and simple metalloporphyrins and use our mechanistic knowledge to rationally design improved metalloporphyrin catalysts for the ORR. 

Boerhaave, Herman. A new method of chemistry including the theory and practice of that art laid down on mechanical priciples, and accommodated to the uses of life. The whole making a clear and rational system of chemical philosophy. To which is prefix d a critical history of chemistry and chemists, from the origin of the art to the present time. Written by the very learned H. Boerhaave. .. translated from the printed ed., collated with the best manuscript copies. By P. Shaw, M.D. and E. Chambers. .. with additional notes and sculptures. 3rd ed ed. Translated by Peter Shaw and Ephraim Chambers. London J. Osborn T. Longman, 1727. 2 vols (xvi, 383, 335, [43] p.)... 

In effect, we are adding a very large real pole to the derivative transfer function. Later, after learning root locus and frequency response analysis, we can make more rational explanations, including why the function is called a lead-lag element. We ll see that this is a nice strategy which is preferable to using the ideal PD controller. 

In conclusion, we have learned a lot from studying chiral dendrimers, about the behavior of such large chiral molecules and about the contributions of the different building blocks to the whole structure. It remains a great challenge to rationalize the origin of the dramatic diastereoselectivity effects observed in the synthesis of certain chiral dendrimers. 

By manipulating genes, chemists have learned to create new enzymes with new functions. To do this rationally and predictably, it is critical to understand the structures and mechanisms of the genes that are being modified. Enzymes and other biological components often function in clusters, in multicomponent sys-... 

Structural factors are important regarding rational design approaches that lead to predicting stable protein folds. Can anything be learned about protein stability from different structural elements, amino acids, and packing of the native folds... 

Vague arrows Some mechanisms have arrows going in all sorts of directions. Arrows must flow from start to finish they should not veer off in different directions. Many of the arrows do not represent electron movements, and it would appear that, as a last resort, students have tried to memorize the mechanism rather than rationalizing it. This is both dangerous and really rather unnecessary. The logical approach gets the right answer, requires relatively little effort, and cuts out the need to learn the mechanism. Mechanisms should not be learnt they should be deduced. 

For the rational design of transition metal catalyzed reactions, as well as for fine-tuning, it is vital to know about the catalytic mechanism in as much detail as possible. Apart from kinetic measurements, the only way to learn about mechanistic details is direct spectroscopic observation of reactive intermediates. In this chapter, we have demonstrated that NMR spectroscopy is an invaluable tool in this respect. In combination with other physicochemical effects (such as parahydrogen induced nuclear polarization) even reactive intermediates, which are present at only very low concentrations, can be observed and fully characterized. Therefore, it might be worthwhile not only to apply standard experiments, but to go and exploit some of the more exotic techniques that are now available and ready to use. The successful story of homogeneous hydrogenation with rhodium catalysts demonstrates impressively that this really might be worth the effort. 

The Drug Information Centre provides a unique learning environment for the education of clinical pharmacologists, other medical doctors, information pharmacists or information technicians, and for any other health care personnel that need training in clinical pharmacology, drug evaluation and the rational use of drugs. 

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