Element Of Diversity Research Articles

Will natural products remain an important source of drug research for the future?

In the highly competitive environment of contemporary pharmaceutical research, natural products provide a unique element of molecular diversity and biological functionality which is indispensable for drug discovery. The emergence of strategies to deliver drug leads from natural products within the same time frame as synthetic chemical screening has eliminated a major limitation of the past. At a more functional level, the application of molecular genetics techniques has permitted the manipulation of biosynthetic pathways for the generation of novel chemical species as well as rendering hitherto uncultivatable microorganisms accessible for secondary metabolite generation. These developments augur well for an industry confronted with the challenge of finding lead compounds directed at the plethora of new targets arising from genomics projects. The exploitation of structural chemical databases comprising a wide variety of chemotypes, in conjunction with databases on target genes and proteins, will facilitate the creation of new chemical entities through computational molecular modelling for pharmacological evaluation.

Librarians: An element of diversity within the faculty

Librarians: An element of diversity within the faculty

Les tempêtes nord-atlantiques : Essai d'analyse géographique. IIe partie : la diversité des tempêtes

SUMMARY The gales which partly make up the features of seasons set an element of diversity through the Atlantic area. The tremendous but unusual tempests raised by hurricanes (5.3 % of the total of gales) move along narrow channels ; they affect the South-Western Atlantic Ocean ; most of them take place from august to november. In winter and early spring, the polar outbreaks (18.4 %) blow less raging but more lasting and widely spread storms, which trace their preferential paths on the cold-water outflows coming from the Arctic Basin. The exlratropical cyclones remain the principal distributors of gales (76.3 %) ; they regulate their own activity and seasonal frequency upon the thermal gradients between the high latitudes and the subtropical ones, between the oceanic and the continental source regions. The spatial distribution of these different gale factors vary the regional features, all through and oceanic climatic area which is often identified with the only « model » of the Land's End regions, in North-Western Europe.

Molecular Restriction of Anti-Hapten Antibody Elicited in Neonatal Rabbits: Antibody Production in Littermates

Abstract The structurally complex antigen dinitrophenylated bovine γ globulin (DNP-BGG) was used to study the immune response of neonatal rabbits. The results of these studies indicated that neonates frequently produce structurally restricted anti-DNP antibody. The isoelectric spectra of certain of these antibodies resembled myeloma proteins or antibodies produced by cell clones. The binding characteristics of these antibodies were consistent with monoclonality or structural homogeneity. An examination of anti-DNP antibody produced by littermates demonstrated that there was no simple genetic control or antibody heterogeneity early in life. Each neonate possessed the potential for anti-DNP antibody production with a differing capacity to express this potential. The results were consistent with the presence at birth of an extensive set of germ-line variable-region genes. while the element of somatic diversity could not be ruled out, somatic processes probably added little to the extent of antibody diversity present in the neonate.