Minerals and the Common Fund for Commodities

This paper reviews the role of minerals in the Integrated Programme for Commodities and the objectives and problems of the Second Account of the Common Fund for Commodities (CFC). It focuses on the least developed countries in Africa, providing specific suggestions for R&D to improve mineral exploration techniques in rain forest and savanna regions; to reduce mine exploration costs; to design equipment suitable for mining narrow veins; to improve concentrating methods for certain ores and to optimize byproduct recovery; to reduce environmental impacts; and to use the waste products of mining. It also discusses demand oriented CFC projects and their policy implications.     

Dynamics of skeleton formation in the Lake Baikal sponge Lubomirskia baicalensis. Part II. Molecular biological studies

In a preceding study it has been reported that the freshwater sponge Lubomirskia baicalensis, living in Lake Baikal (East Siberia), is composed of spicules forming a characteristic pattern which follows radiate accretive growth. Here we report that the spicules are synthesized by the enzyme silicatein, a protein which is related to cathepsin L. The cDNAs for silicatein and the related cathepsin L were isolated and used as probes to show that the mRNA levels of silicatein in the bases of the spicule skeleton of the animals are low, while the mRNA level of cathepsin L in this region exceeds that of the growing zone. This is the first comprehensive study on the importance of the axial filament/silicatein as an essential structural and functional component determining the growth and stability of demosponge spicules.Note: Sequences from Lubomirskia baicalensis have been deposited in the EMBL/GenBank; cDNAs for the putative silicatein (LBSILICA) are deposited under the accession no. AJ786771 and for cathepsin L (LBCATL) under the accession no. AJ786770.