Lattice defects of organic molecular crystals affect their optical or electrical properties by changing the local energy structure. Lattice defects also playa very important role in the chemical and physical properties, for example, as an active site of a catalyst or an initiating point of a solid state reaction. However, very little has been reported on the defect structure of real organic crystals. In the past ten years it became clear that the origin and the structure of the defects depend on the geometrical and chemical nature of the building units of the crystal, the molecules. Molecular size, form and anisotropy, charge distribution, etc. cause the characteristic structure of the defect. Accordingly, a defect structure found in one compound may not be found in others. The defect structure of an organic crystal cannot be defined solely by the displacement of the molecular center from the normal lattice site. A rotational displacement of a molecule is frequently accompanied by a parallel shift of the molecular center. In addition to the usual geometrical crystallographic defects, chemical defects are important too which originate, for example, from differences in the substitution sites of molecules carrying side groups. In order to reveal such defect structures, direct imaging of molecules by high resolution electron microscopy is the only direct method.

The first three chapters of Vol. 3 of Bio-organic Marine Chemistry deal with the chemistry and function of peptides. Chapter 1 by Ireland and coworkers serves as an introduction to marine-derived peptides. It is arranged phyletically and encompasses the entire range from dipeptides to a compound with 95 amino acid residues. Peptides involved in primary metabolism and hence belonging to the realm of macromolecular biochemistry are excluded. However, it might be mentioned in passing that the dividing line between large and small molecule chemistry is continually becoming less distinct. Not only are more compounds of intermediate size, from 1,000 to 10,000 dalton, being discovered, but instruments and techniques, particularly in mass spectrometry and nuclear magnetic resonance have been developed for their structural elucidation by what is considered small molecule methodology. Two groups of peptides are discussed in separate chapters. Biologists who have observed and described the mating behavior of diverse species of marine invertebrates have long surmised that a chemical mechanism might be operating in many cases of individual as well as mass fertilization. The chemical activators of sea urchin sperm prove to be a series of peptides, whose structures and activity are discussed by Suzuki.

This book examines the relationship between Chinese Canadian ethnicity and the use of complementary and alternative medicine (CAM) and explores some of the factors that contribute to CAM use among this visible minority group. Using data from the 2003 Canadian Community Health Survey, multivariate logistic regression techniques are used herein to investigate the extent to which CAM use varies among Chinese Canadians and non-Chinese Canadians. Two three-way interactions, which demonstrate how the combination of certain identity markers increases their predictive value within the model, are also examined. The results indicate that use of complementary and alternative medicine varies according to ethnicity, with Chinese Canadians being more likely to use than non-Chinese Canadians.