Influence of socioeconomic status on design of Batswana home gardens and associated plant diversity patterns in northern South Africa

Over the last two decades, home garden studies have markedly increased in both developed and developing countries. However, garden design and its influence on the overall biodiversity of the urban green infrastructure remains a neglected aspect of home garden research. Home garden surveys were conducted in the North West and Gauteng Provinces of South Africa to contribute to this research focus. The two questions asked in this paper were: (1) Are Batswana garden designs associated with socioeconomic status (SES)? (2) Are the different garden designs characterized by specific plant species richness patterns? We hypothesized that SES influences garden design and that, as the SES of Batswana residents increases, the garden design changes from tshimo to colonial. Our results indicated that garden design reflected less cultural influences and took on a more Westernized colonial design appearance with improvement of SES of Batswana inhabitants. Tshimo gardens tended to have more native and utilitarian species. In contrast, colonial gardens have more alien ornamental species. In affluent areas, sampled Batswana gardens completely changed from a tshimo to colonial garden design. This change indicates that improved socioeconomic status overrides traditional cultural practices.     

Virus Susceptibility of a New Simian Cell Line of Fetal Origin

The cultivation and characterization of a cell line derived from the foreskin of a fetal, rhesus monkey (rhfs2) are described. This cell line has proven satisfactory for isolation and assay of a variety of viral agents of human and simian origin. Virus titrations performed on foreskin cells yielded titers comparable to, or higher than, those obtained in rhesus monkey kidney cells (LLC-MK2). Replicate isolation attempts in our laboratory from simian clinical specimens have proven rhfs2 superior to LLC-MK2 for ease of detection and frequency of isolation.     

The activity of p-methoxybenzylisothiocyanate against Neisseria gonorrhoeae,Haemophilus ducreyi,and other microorganisms

p-Methoxybenzylisothiocyanate was isolated from Lepidium bonariense and found to be responsible for the plants antimicrobial and STD activity. MIC determinations were conducted for p-methoxybenzylisothiocyanate on Haemophilus ducreyi, Neisseria gonorrheae, Candida albicans, Bacillus subtilus, Micrococcus luteus, Staphylococcus aureus, Enterobacter sp., Escherichia coli, Klebsiella pneumoniae, and Psuedomanas aeruginosa. An in vitro cellular toxicity assay showed that at 100 microM (17,9 microg/mL) p-methoxybenzylisothiocyanate is not toxic to living cells.     

Intrinsically disordered C-terminal segments of voltage-activated potassium channels: a possible fishing rod-like mechanism for channel binding to scaffold proteins

Membrane-embedded voltage-activated potassium channels (Kv) bind intracellular scaffold proteins, such as the Post Synaptic Density 95 (PSD-95) protein, using a conserved PDZ-binding motif located at the channels' C-terminal tip. This interaction underlies Kv-channel clustering, and is important for the proper assembly and functioning of the synapse. Here we demonstrate that the C-terminal segments of Kv channels adjacent to the PDZ-binding motif are intrinsically disordered. Phylogenetic analysis of the Kv channel family reveals a cluster of channel sequences belonging to three out of the four main channel families, for which an association is demonstrated between the presence of the consensus terminal PDZ-binding motif and the intrinsically disordered nature of the immediately adjacent C-terminal segment. Our observations, combined with a structural analogy to the N-terminal intra-molecular ball-and-chain mechanism for Kv channel inactivation, suggest that the C-terminal disordered segments of these channel families encode an inter-molecular fishing rod-like mechanism for K(+) channel binding to scaffold proteins.     

Has the code for protein translocation been broken?

Polypeptides chains are segregated by the translocon channel into secreted or membrane-inserted proteins. Recent reports claim that an in vivo system has been used to break the "amino acid code" used by translocons to make the determination of protein type (i.e. secreted or membrane-inserted). However, the experimental setup used in these studies could have confused the derivation of this code, in particular for polar amino acids. These residues are likely to undergo stabilizing interactions with other protein components in the experiment, shielding them from direct contact with the inhospitable membrane. Hence, it is our view that the "code" for protein translocation has not yet been deciphered and that further experiments are required for teasing apart the various energetic factors contributing to protein translocation.