Search results for "Field experiments"
showing 9 items of 9 documents
Relationship between N-cycling communities and ecosystem functioning in a 50-year-old fertilization experiment.
2009
The relative importance of size and composition of microbial communities in ecosystem functioning is poorly understood. Here, we investigated how community composition and size of selected functional guilds in the nitrogen cycle correlated with agroecosystem functioning, which was defined as microbial process rates, total crop yield and nitrogen content in the crop. Soil was sampled from a 50-year fertilizer trial and the treatments comprised unfertilized bare fallow, unfertilized with crop, and plots with crop fertilized with calcium nitrate, ammonium sulfate, solid cattle manure or sewage sludge. The size of the functional guilds and the total bacterial community were greatly affected by …
LES DISCRIMINATIONS A L'EMBAUCHE DANS LA SPHERE PUBLIQUE : EFFETS RESPECTIFS DE L'ADRESSE ET DE L'ORIGINE
2016
Cette étude évalue la discrimination dans l’accès à l’emploi dans trois professions présentes à la fois dans le secteur privé et dans la Fonction Publique. Deux dimensions sont examinées : l’effet de la réputation du lieu de résidence et l’effet de l’origine maghrébine. Elle est réalisée sur données expérimentales de testing réalisé dans trois professions en tension pour lesquelles la discrimination devrait a priori être très réduite : les responsables administratifs de catégorie A, les techniciens de maintenance de catégorie B et les aides soignantes de catégorie C. Pour chaque profession, nous avons construit 3 profils fictifs de candidats à l’emploi similaires en tout point à l’exception…
Improving Teachers' Professionalism on an Experimental Basis
2013
International audience; While education economists have paid considerable attention to the performance of the education sectors, they have placed little emphasis on the management of the pedagogical process. In the context of developing countries, there are clear signs of weak management and too many school personnel neglect tasks deemed essential for student learning. Using data from a large - scale experiment conducted recently in Madagascar, thearticle analyzes the variations in impact of a set of management interventions designed to improve the engagement at work of public primary school teachers. While school - level interventions raise the teachers' level of professionalism on average…
El esfuerzo en el trabajo de los docentes: el impacto del experimento AGEMAD
2014
International audience; Utilizando datos de un experimento randomizado realizado en Madagascar durante dos años escolares completos, se evalúan las heterogeneidades de impacto de unas intervenciones específicamente diseñadas para mejorar la gestión del proceso pedagógico en la escuelas primarias. Nuestros resultados muestran que intervenciones intensivas y directas a lo largo de la jerarquía educativa permiten cambiar el comportamiento de los docentes de manera significativa. Sin embargo, el impacto medio del programa oculta una gran heterogeneidad. Los maestros que tenían pocos alumnos así como los que tenían unas buenas condiciones de trabajo se beneficiaron más de las mismas. Por el cont…
Actuar para mejorar la implicacion en el trabajo de los docentes: resultados diferenciados de un experimento randomizado
2013
En ligne sur http://2013.economicsofeducation.com/user/pdfsesiones/106.pdf?PHPSESSID=vg6pgcqhd5dl52aenlhacj17k6; International audience; Utilizando datos de un experimento randomizado realizado en Madagascar durante dos años escolares completos, se evalúan las heterogeneidades de impacto de unas intervenciones específicamente diseñadas para mejorar la gestión del proceso pedagógico en la escuelas primarias. Nuestros resultados muestran que intervenciones intensivas y directas a lo largo de la jerarquía educativa permiten cambiar el comportamiento de los docentes de manera significativa. Sin embargo, el impacto medio del programa oculta una gran heterogeneidad. Los maestros que tenían pocos …
Risk aversion in prediction markets: A framed-field experiment
2016
International audience; To make better decisions today, companies and other economic agents are interested in getting accurate predictions of future events. Prediction markets can, at least potentially, give those accurate forecasts for the probability of the event by aggregating information from traders. However, formal studies highlight that the risk attitudes of market participants may bias the market equilibrium prices, and consequently make the prediction unreliable. This research examines the effect of participants' risk attitudes on prediction market prices, through a framed field experiment on the two semifinals at the 2015 NCAA Men's Division Basketball Tournament. The results of t…
The design of artificial nestboxes for the study of secondary hole-nesting birds: A review of methodological inconsistencies and potential biases
2010
The widespread use of artificial nestboxes has led to significant advances in our knowledge of the ecology, behaviour and physiology of cavity nesting birds, especially small passerines. Nestboxes have made it easier to perform routine monitoring and experimental manipulation of eggs or nestlings, and also repeatedly to capture, identify and manipulate the parents. However, when comparing results across study sites the use of nestboxes may also introduce a potentially significant confounding variable in the form of differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained. However, the use of …
Effets de quartier, effet de département : discrimination liée au lieu de résidence et accès à l'emploi
2013
L’objet de cette étude est de mesurer la discrimination à l’embauche à l’encontre des jeunes en Ile-de-France en raison du lieu de résidence en considérant plusieurs échelles spatiales de façon à distinguer l’effet de la réputation du département (Paris et la Seine-Saint-Denis), celui de la localité et celui du quartier. L’évaluation est réalisée sur données expérimentales auto-construites de testing selon un protocole permettant d’examiner les effets propres à chacune de ces trois échelles sur l’accès à l’emploi ainsi que leurs effets cumulés. On s’intéresse aux discriminations pour deux professions en tension du secteur de la restauration pour laquelle les discriminations devraient a prio…
Soil inoculation with symbiotic microorganisms promotes plant growth and nutrient transporter genes expression in durum wheat
2015
In a field experiment conducted in a Mediterranean area of inner Sicily, durum wheat was inoculated with plant growth-promoting rhizobacteria (PGPR), with arbuscular mycorrhizal fungi (AMF), or with both to evaluate their effects on nutrient uptake, plant growth, and the expression of key transporter genes involved in nitrogen (N) and phosphorus (P) uptake. These biotic associations were studied under either low N availability (unfertilized plots) and supplying the soil with an easily mineralizable organic fertilizer. Regardless of N fertilization, at the tillering stage, inoculation with AMF alone or in combination with PGPR increased the aboveground biomass yield compared to the uninocula…