Enjeux et dynamiques de la circulation internationale d'un modèle agricole sensible à la nutrition : compréhension par les études de transfert politique

In the last past years, development international agencies have published a growing number of guidelines on how to impact the nutritional aspect of agricultural interventions. The "nutrition sensitive agriculture" concept they develop offers a new vision on how agriculture can or should be considered. If a growing number of actors takes position on this topic at international level, several studies demonstrated however its lack of concrete implementation at country level. Through a Policy Transfer framework, this master degree thesis proposes to analyze how the interactions among actors led to the development of a nutrition sensitive agricultural model, to its exportation and implementation. The goal of this study will be to develop a thought on the nature of the transferred model and to try to understand if this nature could have led to the current limits in implementation.Depuis quelques années, on constate un positionnement accru des principales institutions et instances de l'aide internationale quant aux impacts nutritionnels que peuvent avoir les interventions agricoles. Le concept d'une "agriculture sensible à la nutrition" développé dans ces positionnements propose un profond changement de vision dans la façon de comprendre le secteur agricole. Toutefois, si un nombre croissant d'acteurs semblent se positionner sur le sujet, de nombreuses études soulignent le manque d'application concrète de ce concept, ce dernier connaissant des difficultés à être mis en œuvre au niveau des pays souhaitant lutter contre la sous-nutrition. Ce mémoire de fin d'étude propose donc, à travers le cadre analytique des études de Transfert Politique (Policy Transfert), de s'intéresser aux jeux d'acteurs ayant structuré l'émergence d'un modèle agricole sensible à la nutrition et ayant organisé sa mise en circulation et son transfert. Le but sera ici d'organiser une réflexion autour de la nature du modèle transféré, et de tenter de comprendre si la faible appropriation constaté au niveau des pays peut être inhérente aux modalités dans lesquelles s'effectue ce transfert

Frequency comb metrology with an optical parametric oscillator

We report on the first demonstration of absolute frequency comb metrology with an optical parametric oscillator (OPO) frequency comb. The synchronously-pumped OPO operated in the 1.5-μm spectral region and was referenced to an H-maser atomic clock. Using different techniques, we thoroughly characterized the frequency noise power spectral density (PSD) of the repetition rate frep, of the carrier-envelope offset frequency fCEO, and of an optical comb line νN. The comb mode optical linewidth at 1557 nm was determined to be ~70 kHz for an observation time of 1 s from the measured frequency noise PSD, and was limited by the stability of the microwave frequency standard available for the stabilization of the comb repetition rate. We achieved a tight lock of the carrier envelope offset frequency with only ~300 mrad residual integrated phase noise, which makes its contribution to the optical linewidth negligible. The OPO comb was used to measure the absolute optical frequency of a near-infrared laser whose second-harmonic component was locked to the F = 2→3 transition of the 87Rb D2 line at 780 nm, leading to a measured transition frequency of νRb = 384,228,115,346 ± 16 kHz. We performed the same measurement with a commercial fiber-laser comb operating in the 1.5-μm region. Both the OPO comb and the commercial fiber comb achieved similar performance. The measurement accuracy was limited by interferometric noise in the fibered setup of the Rb-stabilized laser