Ion exchanges in apatites. Effects on composition and properties

The modification of the composition of apatites materials can be made by several processes corresponding to ion exchange reactions which can conveniently be adapted to current coatings and ceramics and are an alternative to the set up of new synthesis methods. In addition to high temperature thermal treatments, which allow to virtually replace partly or totally monovalent OH- anion of stoichiometric hydroxyapatite by any halogen ion or carbonate, aqueous processes corresponding to dissolution-reprecipitation reactions have also been proposed and used. The most interesting possibilities are however provided by aqueous ion exchange reactions involving nanocrystalline apatites. These apatites are characterised by the existence on the crystal surface of a hydrated layer of loosely bound mineral ions which can be easily exchanged in solution. This layer offers a possibility to trap mineral ions and possibly active molecules which can modify the apatite properties. Such processes are involved in mineralised tissues and could be used in biomaterials for the release of active mineral species

A Behavioral Change Perspective of Maroon Soil Fertility Management in Traditional Shifting Cultivation in Suriname

In Suriname, the Maroons have practiced shifting cultivation for generations, but now the increasing influence of modern society is causing a trend of decreasing fallow periods with potentially adverse effects for the vulnerable tropical soils. Adoption of appropriate soil fertility management (SFM) practices is currently slow. Combining methods from cultural ecology and environmental psychology, this study identifies two groups with divergent behavioral intentions which we term semi-permanent cultivators and shifting cultivators. Semi-permanent cultivators intend to practice more permanent agriculture and experiment individually with plot-level SFM. Shifting cultivators rely on traditional knowledge that is not adequate for their reduced fallow periods, but perceive constraints that prevent them practicing more permanent agriculture. Semi-permanent cultivators act as a strong reference group setting a subjective norm, yet feel no need to exchange knowledge with shifting cultivators who are in danger of feeling marginalized. Drawing on a political ecology perspective, we conclude that cultural ecological knowledge declined due to negative perceptions of external actors setting a strong subjective norm. Semi-permanent cultivators who wish to enter the market economy are most likely to adopt SFM. We conclude that any future SFM intervention must be based on an in-depth understanding of each group’s behavior, in order to avoid exacerbating processes of marginalization

A framework for scabies control.

Scabies is a neglected tropical disease (NTD) that causes a significant health burden, particularly in disadvantaged communities and where there is overcrowding. There is emerging evidence that ivermectin-based mass drug administration (MDA) can reduce the prevalence of scabies in some settings, but evidence remains limited, and there are no formal guidelines to inform control efforts. An informal World Health Organization (WHO) consultation was organized to find agreement on strategies for global control. The consultation resulted in a framework for scabies control and recommendations for mapping of disease burden, delivery of interventions, and establishing monitoring and evaluation. Key operational research priorities were identified. This framework will allow countries to set control targets for scabies as part of national NTD strategic plans and develop control strategies using MDA for high-prevalence regions and outbreak situations. As further evidence and experience are collected and strategies are refined over time, formal guidelines can be developed. The control of scabies and the reduction of the health burden of scabies and associated conditions will be vital to achieving the targets set in WHO Roadmap for NTDs for 2021 to 2030 and the Sustainable Development Goals

Indigenous practices of water management for sustainable services : Case of Borana and Konso, Ethiopia

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Agricultural innovation system capacity development: Tools, principles or policies?

One of the most notable changes in the field of agricultural development has been the growing popularity of thinking in terms of innovation systems rather than just focusing on research. Addressing the scarcity of fodder: livestock in northern Nigeria. A persistent criticism of agricultural research, voiced by a whole generation of rural development practitioners and system thinkers, has been the unresponsiveness of research to the changing needs of clients. It has also been observed that while research is good at developing new technologies, the adoption of these technologies has been weak. Focusing on innovation rather than research shifts the emphasis to the application of knowledge and technology rather than just their production. Although there seems to be growing acceptance of this logic in the development research community, what seems to be less clear is how the idea of an innovation system can be translated into practice. The challenge in this is the highly context-specific nature of capacities that need to be developed. Researchers are now exploring a number of ways to nurture the development of these context-specific capacities

Renforcement des capacités des systèmes d’innovation agricoles : Des outils, des principes ou des politiques ?

L’une des évolutions les plus notables en matière de développement agricole est la manière dont la réflexion dans ce domaine s’intéresse davantage aux systèmes d’innovation plutôt qu’à la recherche en elle-même. Le problème récurrent de la pénurie de fourrage : bétail dans le nord du Nigeria. Une des principales critiques adressée à la recherche agricole, et exprimée par toute une génération de praticiens du développement rural et de penseurs systémiques, est que la recherche ne parvient pas à répondre aux besoins en constante évolution des agriculteurs. Ils soulignent également que si la recherche est un moteur de développement des technologies, l’adoption de celles-ci sur le terrain reste faible. Le centrage sur l’innovation plutôt que sur la recherche a pour avantage de mettre plus fortement l’accent sur l’application des connaissances et des technologies plutôt que sur la simple production de celles-ci. Même si cette logique est de plus en plus largement acceptée au sein du monde de la recherche sur le développement, il semble qu’il reste encore à définir comment la notion de système d’innovation peut être traduite dans la pratique. Le challenge à ce niveau est la nature, extrêmement spécifique au contexte, des capacités à développer. Les chercheurs explorent actuellement divers moyens de favoriser le développement de ces capacités spécifiques au contexte

Desarrollo de la capacidad de sistemas de innovación agrícola : ¿Instrumentos, principios o políticas?

Uno de los cambios más notables en materia de desarrollo agrícola ha sido la creciente aceptación de las teorías de sistemas innovadores, en lugar de limitarse a la investigación. Persiste el antiguo problema de la escasez de forraje: ganado en Nigeria septentrional. Una persistente crítica de la investigación agrícola, expresada por una generación de profesionales del desarrollo rural y teóricos de sistemas, ha sido que la investigación no ha respondido a las cambiantes necesidades de los agricultores; y también que, si bien la investigación es eficaz para desarrollar tecnologías, la adopción de éstas ha sido débil. Al centrarse en la innovación y no en la investigación, el énfasis pasa a la aplicación de conocimientos y tecnologías, en lugar de limitarse a su producción. Aunque, al parecer, esta lógica es cada vez más aceptable entre los investigadores del desarrollo, hay menos claridad sobre cómo la idea de un sistema de innovación puede traducirse en la práctica. La dificultad reside en la naturaleza de las capacidades a desarrollar, que son específicas para cada contexto. Actualmente, los investigadores están considerando varias maneras de promover el desarrollo de tales capacidades