Linking Biotechnology and Agricultural Biodiversity Resources in Holistic Strategy in West Africa

Modern economic activities are heavily dependent on using diversity of biological resources. Africa has a wealth of biodiversity resources which, with the appropriate application of biotechnological tools for conservation and use, can serve as sources of wealth creation. Proper harnessing of the linkages between biotechnology and the diversity of biological resources is required to meet challenges of food security, health, poverty and wealth creation in West African countries. The paper explores some of the key applications of biotechnology for conservation of agricultural biodiversity resources, and considers the potential threat of biotechnology to diversity of genetic resources. It also explores complex issues that inform current policy debates. It concludes that Government support is required for theconservation and breeding of farmers’ varieties, or landraces by public breeding programmes, and the design of private and public mechanisms to ensure that the pursuit of biotechnology does not compromise the diversity in biological resources. It would be strategic for West African countries to establish and explore beneficial linkages between the subregional genetic resources conservation initiative and biotechnology programmes. Some pertinent questions are raised on how to best manage the strategic interplay between biotechnology and diversity in agricultural biodiversity resources. The provision of adequate information is highlighted to inform decisions and choices based on the real valueand potential risks of biotechnology

Structural-Properties Of Amorphous Hydrogenated Carbon .1. A High-Resolution Neutron-Diffraction Study

The structure of samples of amorphous hydrogenated carbon, prepared from acetylene and propane precursors, containing 35 and 32 at.% hydrogen, respectively, was investigated by time-of-flight neutron diffraction in the range 0.2-50 angstrom-1 using the ISIS spallation source. The large dynamic range of the data ensures a real-space resolution sufficient to reveal directly the proportions of sp2 and sp3 hybridized carbon. The results show that, in these hard carbon materials, the carbon-atom sites are predominantly sp2 bonded, and the carbon-carbon single bond:carbon-carbon double bond ratio is about 2.5:1. The detailed information on atomic correlations thus provided is used to discuss current structural models, and in particular the data are used to show that these models require significant modification

The effect of hydrogen dilution on the structure of a-C : H

Two a-C:H samples were prepared using a fast-atom deposition system from acetylene and an acetylene/hydrogen gas mixture. Their structure was investigated using neutron and x-ny diffraction and infrared spectroscopy measurements. Compositional analysis shows that a 1:1 C2H2:H-2 mixture results in a change from a-C-77:H-23 to a-C-79:H-21, i.e. has a very small effect on the composition. The diffraction data also show that the addition of hydrogen to the precursor gas has no significant effect on the average bond distances and angles but shows a small change in the H-C-H and C-C-H correlations between the two samples. However, the infrared data show that there are significant changes in the bonding of hydrogen within the sample-changes which do not affect the average network structure. We observe a decrease in the amount of sp(3) CH2 and CH3 groups, and an increase in the fraction of sp(2) and sp(3) CH groups, with the formation of a second sp(2) CH bonding environment in the hydrogen-diluted sample. Therefore, in addition to providing useful structural information on these a-C:H samples, this set of experiments illustrates very well the complementary nature of the data from diffraction and spectroscopic techniques

A spectroscopic study of the structure of amorphous hydrogenated carbon

A range of amorphous hydrogenated carbon (a-C:H) samples have been studied using inelastic neutron spectroscopy (INS) and Fourier transform infrared (FTIR) spectroscopy. Using these complementary techniques, the bonding environments of both carbon and hydrogen can be probed in some detail, with the INS data providing not only qualitative but also quantitative information. By comparing the data from each of the samples we have been able to examine the effects of different deposition conditions, i.e. precursor gas, deposition energy and deposition method, on the atomic-scale structure of a-C:H

Biodiversity, traditional medicine and public health: where do they meet?

Given the increased use of traditional medicines, possibilities that would ensure its successful integration into a public health framework should be explored. This paper discusses some of the links between biodiversity and traditional medicine, and addresses their implications to public health. We explore the importance of biodiversity and ecosystem services to global and human health, the risks which human impacts on ecosystems and biodiversity present to human health and welfare

Задача о рюкзаке с выпуклыми монотонными сепарабельными функциями

Рассмотрена модельная задача о рюкзаке. Предложена схема решения задачи о рюкзаке с выпуклыми монотонными сепарабельными функциями