Formulation d’un Programme National du Secteur Rural robuste au Burkina Faso : Quelles thématiques nouvelles issues du processus des scénarios socio- économiques et climatiques?

Dans le cadre du partenariat initié en 2015 entre le Programme de recherche du CGIAR sur le Changement Climatique, l’Agriculture et la Sécurité Alimentaire (CCAFS) et le Secrétariat Permanent de la Coordination des Politiques Sectorielles Agricoles (SP-CPSA), en collaboration avec d’autres programmes et centres de recherche du CGIAR, une analyse du Programme National du Secteur Rural (PNSR) fondée sur les scénarios socio-économiques et climatiques du CCAFS a pu être menée avec la participation effective des parties prenantes du secteur rural du Burkina Faso. Les 22 recommandations qui en sont issues devraient permettre une prise en compte effective des facteurs socio- économiques, environnementaux et climatiques plausibles dans le futur proche et lointain, et ainsi aider à rendre le PNSR II plus robuste face aux incertitudes futures liées au changement climatique, aux dynamiques mondiales, aux évolutions socioéconomiques, aux changements des normes et valeurs, etc. En outre, un exercice avec l’ensemble des acteurs impliqués a consisté à traduire lesdites recommandations en actions et thématiques nouvelles à prendre en compte lors de la formulation du PNSR II. Les échanges entre acteurs ont également fait ressortir la nécessité d’une implication transversale de la recherche dans la mise en œuvre des activités de cet important outil politique qu’est le PNSR I

Formulation of a Robust National Rural Sector Program in Burkina Faso: What new themes have emerged from the socio-economic and climate scenarios process?

Under the partnership initiated in 2015 between the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) and the Permanent Secretariat for Coordination of Agricultural Sector Policies (SP-CPSA), in collaboration with other CGIAR research programs and centers, an analysis of the National Rural Sector Program (PNSR) based on the CCAFS socio-economic and climate scenarios was conducted with the effective participation of rural sector stakeholders in Burkina Faso. Twenty-two (22) recommendations were made to allow for the effective mainstreaming of plausible socio-economic, environmental and climatic factors in the near and distant future, that will make PNSR II more robust to face future uncertainties related to climate change, global dynamics, socio-economic changes, changes in norms and values, etc. In addition, an exercise with all the stakeholders helped in translating the said recommendations into new actions and themes to be taken into account when formulating PNSR II. Discussions between the stakeholders also underscored the need for crosscutting involvement of research in the implementation of the activities of PNSR II

Estimation of parameters in complex N-15 tracing models by Monte Carlo sampling

The most widely used method to quantify gross N transforination rates in soils is based on N-15 dilution and enrichment principles. To identify rate parameters, N-15-tracing experiments are analysed by models that are linked to algorithins that try to minimize the misfit between modelled and observed data. In Currently available N-15-tracing models optimization algorithms are based oil the Levenberg-Marquardt method that is suitable for the determination of small number of parameters. Therefore, these models are restricted to a few processes. Methods based on Monte Carlo sampling have the potential to overcome restrictions on parameter numbers but have not been tested for application in N-15-tracing models. Here, for the first time, we use a Markov chain Monte Carlo (MCMC) method with a tracing model to simultaneously determine the probability density functions (PDFs) of the whole set of parameters for a previously published data set [Muller, C., Stevens, R.J., Laughlin, R.J., 2004. A N-15 tracing model to analyse N transformations in old grassland soil. Soil Biology & Biochemistry 36, 619-632]. We show that the MCMC method can simultaneously determine PDFs of more than 8 parameters and demonstrate for the first time that it is possible to optimize models where transformations are described by Michaelis-Menten kinetics. Setting the NH4+ oxidation rate to Michaelis-Menten kinetics reduced the misfit by 19%. Together with monitoring diagnostics for parameter convergence, the MCMC method is a very efficient and robust technique to determine PDFs for parameters in N-15-tracing models that Contain large number of N transformations and complex process descriptions. (c) 2006 Elsevier Ltd. All rights reserved. [References: 29

Leaky nitrogen cycle in pristine African montane rainforest soil

Many pristine humid tropical forests show simultaneously high nitrogen (N) richness and sustained loss of bioavailable N forms. To better understand this apparent upregulation of the N cycle in tropical forests, process-based understanding of soil N transformations, in geographically diverse locations, remains paramount. Field-based evidence is limited and entirely lacking for humid tropical forests on the African continent. This study aimed at filling both knowledge gaps by monitoring N losses and by conducting an in situ 15N labeling experiment in the Nyungwe tropical montane forest in Rwanda. Here we show that this tropical forest shows high nitrate (NO3−) leaching losses, confirming findings from other parts of the world. Gross N transformation rates point to an open soil N cycle with mineralized N nitrified rather than retained via immobilization; gross immobilization of NH4+ and NO3− combined accounted for 37% of gross mineralization, and plant N uptake is dominated by ammonium (NH4+). This study provided new process understanding of soil N cycling in humid tropical forests and added geographically independent evidence that humid tropical forests are characterized by soil N dynamics and N inputs sustaining bioavailable N loss

Higher body mass index is associated with increased lung stiffness and less airway obstruction in individuals with asthma and fixed airflow obstruction.

Higher body mass index (BMI) is associated with less severe airway obstruction in older asthma patients with fixed airflow obstruction. This is potentially mediated through BMI-related mechanisms that increase lung stiffness (i.e. reduce lung compliance). https://bit.ly/3jBwCNy