Conformational requirements at the prostaglandin cyclooxygenase receptor site: A template for designing non-steroidal anti-inflammatory drugs

When space-filling models of the peroxy radical precursor of PGG were compared with models of 2(S)-(3-chloro-4-cyclohexylphenyl) propionic acid and other acidic cyclooxygenase inhibitors several common structural features were revealed. This led us to propose a template for designing non-steroidal anti-inflammatory drugs (NSAID's) based on the conformation of the peroxy radical immediately prior to its cyclisation to PGG. The template can be equated with a complementary cyclooxygenase receptor site.     

Pollination biology ofOpuntia polyacantha andOpuntia phaeacantha (Cactaceae) in southern Colorado

The phenology, compatibility system, and pollinator fauna ofOpuntia polyacantha Haw. andO. phaeacantha Engelm. in southern Colorado were studied and compared. The total blooming periods overlap, but the peak of blooming differs between the species withO. polyacantha blooming first and for longer. Neither species is apomictic,O. polyacantha is largely self-incompatible andO. phaeacantha is self-compatible but may not automatically fully self-pollinate. Examination of flowering structures showed that the former has larger flowers with more perianth parts and heavier (but fewer) anthers. Further the flowers of the allogamous species are visited by greater diversity (but similar abundance) of pollinators. Medium to large bees of the generaDiadasia, Lithurge, Melissodes, Bombus, Agapostemon andMegachile were found to be effective pollinators of the Opuntias studied. The two species were compared as to their floral attributes, breeding systems, and pollinators, and the possible role of competition for pollinators is discussed with respect to its role in their evolutionary paths.     

Growing trees: risks and rewards for society

Forests provide 1.75 billion cubic meters of timber each year and a similar amount of fuel wood. Our understanding of forest ecosystems is far from complete. Biotechnology can provide means to speed up adaptation by forest species in response to pathogen introduction, climate change, or other perturbations. Consensus building on forest issues is always likely to be difficult, as diversity in the nature of forests and their cultural and historical significance must be recognized. The potential risks and possible benefits of deploying or choosing not to deploy forest biotechnology products must be considered on a case-by-case, product- rather than process-driven basis for rational, evidence-based decisions to be reached. Aspects of ecologically neutral field trials, ecological and social perceptions of risk, and steady state and dynamic paradigms of nature are discussed alongside challenges facing biotechnology in adequately avoiding or limiting risks to allow deployment in forests. Communicated by Ronald Sederoff