Centro de Estudos Municipais e Metropolitanos: CEMME

1 fôlder (4 p.) : color. ; 14 x 21 cmFôlder de apresentação do "Centro de Estudos Municipais e Metropolitanos (CEMME)", departamento da Fundação João Pinheiro (FJP), mostrando seus objetivos e projetos para o segundo semestre de 1996 e primeiro semestre de 1997

Model and experiences of initiating collaboration with traditional healers in validation of ethnomedicines for HIV/AIDS in Namibia

Many people with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) in Namibia have access to antiretroviral drugs but some still use traditional medicines to treat opportunistic infections and offset side-effects from antiretroviral medication. Namibia has a rich biodiversity of indigenous plants that could contain novel anti-HIV agents. However, such medicinal plants have not been identified and properly documented. Various ethnomedicines used to treat HIV/AIDS opportunistic infections have not been scientifically validated for safety and efficacy. These limitations are mostly attributable to the lack of collaboration between biomedical scientists and traditional healers. This paper presents a five-step contextual model for initiating collaboration with Namibian traditional healers in order that candidate plants that may contain novel anti-HIV agents are identified, and traditional medicines used to treat HIV/AIDS opportunistic infections are subjected to scientific validation. The model includes key structures and processes used to initiate collaboration with traditional healers in Namibia; namely, the National Biosciences Forum, a steering committee with the University of Namibia (UNAM) as the focal point, a study tour to Zambia and South Africa where other collaborative frameworks were examined, commemorations of the African Traditional Medicine Day (ATMD), and consultations with stakeholders in north-eastern Namibia. Experiences from these structures and processes are discussed. All traditional healers in north-eastern Namibia were willing to collaborate with UNAM in order that their traditional medicines could be subjected to scientific validation. The current study provides a framework for future collaboration with traditional healers and the selection of candidate anti-HIV medicinal plants and ethnomedicines for scientific testing in Namibia

One step forward, one step sideways? Expanding research capacity for neglected diseases

<p>Abstract</p> <p>Background</p> <p>There is general agreement, including from the pharmaceutical industry, that current market based methods of generating research into the development of pharmaceutical products that are relevant for developing countries do not work. This conclusion is relevant not just for the most neglected diseases such as leishmaniasis but even for global diseases such as cancer and cardiovascular disease.</p> <p>Discussion</p> <p>Stimulating research will mean overcoming barriers such as patent thickets, poor coordination of research activities, exclusive licensing of new technologies by universities and the structural problems that inhibit conducting appropriate clinical trials in developing countries. In addition, it is necessary to ensure that the priorities for research reflect the needs of developing countries and not just donors. This article will explore each of these issues and then look at three emerging approaches to stimulating research -paying for innovation, priority review sales or vouchers and public-private partnerships, - and evaluate their strengths and weaknesses.</p> <p>Summary</p> <p>All of the stakeholders agree that there is a pressing need for a major expansion in the level of R&D. Whatever that new model turns out to be, it will have to deal with the 5 barriers outlined in this paper. Finally, none of the three proposals considered here for expanding research is free from major limitations.</p

The role of interfaces in the high temperature deformation and failure of polycrystalline alumina

Numerous studies on high temperature deformation of polycrystalline alumina in compression and bending have yielded stress exponents for deformation of n~2, where &epsi;�?$\sigma^n$ and &epsi; and σ are the strain rate and stress, respectively. Since a stress exponent of ~2 is typical of superplastic metals, it was anticipated that alumina will exhibit large elongations to failure, in a manner similar to the large strains reported in compression. However, tensile testing of pure alumina has revealed that pure alumina fails prematurely due to extensive cavitation, so that the elongations to failure are typically on the order of only ~20%. This report examines the role of interfaces in the high temperature deformation and failure of polycrystalline alumina, with a special emphasis on grain boundary mobility and energy. The reported experimental data will be compared with existing theoretical models, and additional factors not considered in theoretical models will be outlined. Furthermore, this report discusses strategies to enhance the tensile ductility of polycrystalline alumin

Diffusion creep in ceramics

At sufficiently low stresses, where intragranular dislocation mobility is rather limited, plastic deformation can occur solely by the diffusion of vacancies either through the matrix (Nabarro-Herring) or along grain boundaries (Coble). The process of diffusion creep has been modelled theoretically for over 50 years now, although there still remain some doubts over the experimental validation of the models. It has been suggested that low intragranular dislocation mobility leads to more frequent observations of diffusion creep in ceramics compared to metals. In ceramics, the diffusion creep process is more complex than in metals due to the need to account for charge balance and the transport of two or more ionic species along two different paths (lattice or grain boundary). The report critically evaluates the experimental observations of diffusion creep in some oxide-based ceramic systems. In addition, the process of ambipolar diffusion in ceramics is examined with two different considerations: (a) the total flux to grain boundaries is in the appropriate stoichiometric ratio, so that the cations and anions may be transported along different paths, and (b) the flux along each transport path is in the appropriate stoichiometric ratio. It is demonstrated that the above two considerations lead to substantially different predictions on rate controlling processe

Superplastic ceramics

The ability of some fine grained crystalline metals to exhibit very large elongations to failure, termed superplasticity, is being utilized to form complex-shaped components for aerospace and other applications. Recently, there has been considerable research activity into extending the concept of superplasticity to ceramics, and large strains to failure have been demonstrated in several fine grained ceramic systems. The paper reviews the mechanical properties of superplastic metals, and examines conditions favorable for observing superplasticity in ceramic

The influence of grain size on deformation of copper

It is well know that grain boundaries enhance strength at low temperatures by acting as obstacles to dislocation motion, and they retard strength at higher temperatures by processes involving grain boundary sliding. The available data on the influence of grain boundaries on deformation in copper is summarized. Equi-channel angular extrusion offers a convenient means for imposing severe plastic deformation to refine the grain size in bulk materials. Experimental data on fine grained copper produced by equi-channel angular extrusion will be described, and the implications of the data for diffusion creep and superplasticity will be discussed

Superplasticity in electrodeposited nanocrystalline nickel

Electrodeposited nanocrystalline Ni films were processed with different levels of S, to evaluate the role of S on superplasticity. All the materials exhibited high strain rate superplasticity at a relatively low temperature of 777 K. Microstructural characterization revealed that the S was converted to a Ni3S2 phase which melts at 908 K; no S could be detected at grain boundaries. There was no consistent variation in ductility with S content. Superplasticity was associated with a strain rate sensitivity of similar to 0.8 and an inverse grain size exponent of similar to 1 both of which are unusual observations in superplastic flow of metals. Based on the detailed experiments and analysis, it is concluded that superplasticity in nano-Ni is related to an interface controlled diffusion creep process, and it is not related to the presence of S at grain boundaries or a liquid phase at grain boundaries. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved