We briefly review the taxonomic history of the Podocarpaceae, with an emphasis on the recognition of numerous segregate genera out of Podocarpus sensu lato. Despite some controversy over the recognition of these genera, molecular data (DNA sequences) provide evidence that supports this taxonomy. The implications for African Podocarpaceae are discussed. In particular, molecular data support the recognition of Afrocarpus as distinct from Podocarpus. Additional taxonomic problems concerning the possible segregation of Podocarpus milanjianus from P. latifolius are addressed using DNA sequence data from the nuclear internal transcribed spacer 2 (ITS2) region. Results of this are inconclusive, and suggest that alternative DNA-based evidence, such as from AFLPs or microsatellites, may be more informative in resolving such species complexes in African Podocarpus.

Mycorrhizal fungi are intimately associated with plant roots, affecting plant growth, health and increasing the plants' tolerance to environmental stress. Several mycorrhizal types are recognized based primarily on morphological characteristics within plant roots. When considering propagation and management of an indigenous plant species, it is essential to know its mycorrhizal status. Root samples from 17 tree species common to the pockets of forest in the Eastern Cape province, and representing the families Rubiaceae, Scrophulariaceae, Oleaceae, Podocarpaceae, Myrsinaceae, Anacardiaceae, Caesalpinoideae, Papilionoideae, Rutaceae, Meliaceae, Celastraceae, Flacouticeae and Ebenaceae, were sampled and examined for mycorrhizal colonization. Microscopic examination of all the species produced evidence of morphological structures indicative of endomycorrhizal associations as indicated by the presence of intercellular hyphae combined with vesicles, arbuscules or hyphal coils. Hyphal coils (also known as Paris-type associations) appeared to be abundant, especially within the Cassine genus. Arbuscules (also known as Arum-type associations) were scarce but sometimes present, and vesicles were prolific in Olea capensis. Most of the tree species examined have been assigned arbuscular mycorrhizal status. No ectomycorrhizal associations were recorded.

There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.

We review and synthesize recent South African work that examines the role and importance of non-timber forest products (NTFPs) in the daily lives of rural people in South Africa. The most commonly used such products are wild spinaches, fuelwood, wooden utensils edible fruits, grass hand-brushes, and twig hand-brushes, used by 85% or more of households. More than half the households investigated also make use of edible insects, wood for construction, bushmeat, wild honey and reeds for weaving. Individual households may exploit dozens of animal and plant species. The range in annual, direct-use values is large, from less than R1000 per household per year to over R12 000. The value to rural households is manifest through a daily net function which represents a cost saving to the families involved and to the state, as well as through an emergency net, which serves as an insurance in times of misfortune, such as drought, disease, and unexpected economic hardship. The emergency net function has hardly been quantified in South Africa and internationally. Ad hoc trade in NTFPs is a common emergency net, which in some instances evolves into a permanent way of life. Financial returns from trade are variable, depending on resource type and hours worked, but are typically low. Despite the small cash incomes from trade, they provide an important contribution that complement the diverse livelihood strategies within a household, especially for the poorer sectors of rural society. Moreover, there are non-financial benefits of NTFP trade that are commonly overlooked.

Molecular chaperones consist of several highly conserved families of proteins, many of which consist of heat shock proteins. The primary function of molecular chaperones is to facilitate the folding or refolding of proteins, and therefore they play an important role in diverse cellular processes including protein synthesis, protein translocation, and the refolding or degradation of proteins after cell stress. Cells are often exposed to different stressors, resulting in protein misfolding and aggregation. It is now well established that the levels of certain molecular chaperones are elevated during stress to provide protection to the cell. The focus of this review is on the impact of molecular chaperones in biology, medicine and protein biotechnology, and thus covers both fundamental and applied aspects of chaperone biology. Attention is paid to the functions and applications of molecular chaperones from bacterial and eukaryotic cells, focusing on the heat shock proteins 90 (Hsp90), 70 (Hsp70) and 40 (Hsp40) classes of chaperones, respectively. The role of these classes of chaperones in human diseases is discussed, as well as the parts played by chaperones produced by the causative agents of malaria and trypanosomiasis. Recent advances have seen the application of chaperones in improving the yields of a particular target protein in recombinant protein production. The prospects for the targeted use of molecular chaperones for the over-production of recombinant proteins is critically reviewed, and current research on these chaperones at Rhodes University is also discussed.

Under stress conditions, proteins unfold or misfold, leading to the formation of aggregates. Molecular chaperones can be defined as proteins that facilitate the correct folding of other proteins, so that they attain a stable tertiary structure. In addition, they promote the refolding and degradation of denatured proteins after cellular stress. Heat shock proteins form one of the main classes of molecular chaperones. We are interested in determining if the genome of the coelacanth (Latimeria chalumnae) encodes a heat shock protein-based cytoprotection mechanism. We have isolated 50 kb and larger coelacanth genomic DNA from frozen skin tissue of L. chalumnae. From the alignments of several fish Hsp70 proteins, conserved regions at the N- and C-termini were identified. Codon usage tables were constructed from published coelacanth genes and degenerate primers were designed to isolate the full-length hsp70 gene and regions encoding the ATPase and the peptide binding domains. Since it is known that the tilapia and Fugu inducible hsp70 genes are intronless, we proceeded on the assumption that a coelacanth inducible hsp70 would also be intronless. A large fragment (1840 bp) encoding most of a coelacanth Hsp70 protein, and two partial fragments encoding a coelacanth Hsp70ATPase domain (1048 bp) and peptide binding domain (873 bp), were isolated by polymerase chain reaction amplification. Protein sequences translated from all the nucleotide sequences were closely identical to typical Hsp70s. This is the first study to provide evidence for a cytoprotection mechanism in the coelacanth involving an inducible Hsp70.

The comprehension of medicine instructions is essential for the safe and effective use of medicines. In cases where low literacy constitutes a possible barrier to understanding written medicine information fully, the inclusion of pictograms may facilitate comprehension. Twenty-three internationally available pictograms and 23 corresponding locally developed images were evaluated in 304 low-literate respondents from eight different South African language groups. Demographic data were collected and an English literacy test was administered to those respondents who had stated that they could read English. Interviewees were shown the 46 pictograms in random order and were asked for their interpretation. Preference for either the international or local version was assessed. Correct interpretation of individual pictograms ranged from 14% to 97%. Images which had been developed locally were more successful in eliciting correct interpretations than those obtained from an international source (USP pictograms). Only 2 of the 23 USP pictograms achieved the 85% criterion of the American National Standards Institute compared with 12 of 23 locally developed counterparts. Local pictograms were preferred over the American ones in all cases. Standard of education had a significant influence on interpretation, whereas no significant differences in interpretation could be attributed to cultural diversity between the African language groups. Almost all respondents (98%) reacted positively to the idea of having pictograms on their medicine labels. The success of the local pictograms highlighted the value of a rigorous and consultative design and test process. Results from one African language group can reliably be extrapolated to other groups in South Africa.

This review focuses on applications of the Baylis-Hillman reaction in the synthesis of various heterocyclic products, which include indolizines, chromenes, thiochromenes, coumarins and quinolines. Attention is also given to the mechanistic implications and the elaboration of various products to afford compounds with medicinal potential.

No description available.

Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.