Search results for "Quantitative"
showing 10 items of 2409 documents
Juxtaposition ou imbrications des analyses qualitative et quantitative. Journées Scientifiques de l'Université de Nantes
2009
De l'école unifiée aux écoles plurielles. Évaluation internationale des politiques de différenciation et de diversification de l'offre éducative
2004
The last two decades have been marked in many developed and emerging countries by major educational reforms, around special themes: decentralization, the differentiation of courses and school content and the free choice of school. These three education policies, which aim to differentiate and diversify the educational offer, call into question the traditional organization of modern educational systems. This study seeks to evaluate the effects of these reforms on the performance of education systems, thanks to an econometric analysis based, on the one hand, on the results of the PISA 2000 international evaluation and, on the other, on a a fine description of the institutional characteristics…
Matrices de pondérations et contexte spatio-temporel en économétrie spatiale
2013
International audience
La répression du travail illégal à l'épreuve des "faux" indépendants
2022
Un comité interministériel « anti-fraude consacré à la lutte contre le travail illégal », réuni le 11 mars 2022, a présenté le bilan du Plan national de lutte contre le travail illégal 2019-2021 et les premières orientations pour le plan 2022-2024, dans lequel est en particulier pointé le développement des fraudes entourant le « faux » travailleur indépendant, notamment par le biais des plateformes de mise en relation et la « gig economy ». Où fixer la frontière entre le salariat et le travail indépendant ? la présente contribution étudie dans quelle mesure la situation d’un« faux » indépendant peut être identifiée et relever du travail illégal, avant de s’interroger sur l’efficacité de l’a…
Coumarin-Phosphine-Based Smart Probes for Tracking Biologically Relevant Metal Complexes: From Theoretical to Biological Investigations
2016
International audience; Ten metal-based complexes and associated ligands have been synthesized and characterized. One of the metal ligands is a coumarin-phosphine derivative, which displays tunable fluorescence properties. The fluorescence is quenched in the case of the free ligand and ruthenium and osmium complexes, whereas it is strong for the gold complexes and phosphonium derivatives. These trends were rationalized by theoretical calculations, which revealed non-radiative channels involving a dark state for the free ligands that is lower in energy than the emissive state and is responsible for the quenching of fluorescence. For the Ru-II and Os-II complexes, other non-radiative channels…
Identifiability problem for recovering the mortality rate in an age-structured population dynamics model
2014
In this article is studied the identifiability of the age-dependent mortality rate of the Von Foerster–Mc Kendrick model, from the observation of a given age group of the population. In the case where there is no renewal for the population, translated by an additional homogeneous boundary condition to the Von Foerster equation, we give a necessary and sufficient condition on the initial density that ensures the mortality rate identifiability. In the inhomogeneous case, modelled by a non-local boundary condition, we make explicit a sufficient condition for the identifiability property, and give a condition for which the identifiability problem is ill-posed. We illustrate this latter case wit…
Climate and agriculture: empirical evidence for countries and agroecological zones of the Sahel
2022
International audience; ow heterogenous is the impact of climate change across space and the type of agricultural production? In this paper, we investigate the relationship between climate change and variability, measured by temperature and rainfall, and agricultural production at the country and agroecological zone levels of the Sahel. We consider a crop production index and five cereals (maize, millet, sorghum, wheat and rice). Based on an original climate database and an agricultural production function estimated for the period 1961–2016, we show that average rainfall and temperature during the growing season indeed have highly heterogeneous effects on agricultural production, depending …
Composantes de l’architecture racinaire de la plante associées aux QTL de résistance à Aphanomyces euteiches dans des lignées quasi-isogéniques de po…
2021
Pea (Pisum sativum L.) is the most cultivated seed legume in the world after common bean. But it issubject to a disease against which there is no effective treatment, root rot caused by Aphanomyceseuteiches. The only sustainable solution to control A. euteiches is genetic control. Previous studies haveidentified a positive correlation between the root area or biomass of lines and their level of resistance toroot rot caused by A. euteiches. The aim of the internship, which was part of the research project"Diversification and Combination of Aphanomyces Resistance QTLs in Protein Pea (DORA)", was toidentify whether changes in the components of the root system architecture of pea are induced by…
Role of nitric oxide synthase (NOS) of Klebsormidium nitens: Identification and characterization of partners
2021
National audience; Nitric oxide (NO) is an important cellular signaling molecule across kingdoms. During bioticor abiotic stresses, NO burst is detected in both plants and mammals although no sequenceencoding the well described mammalian NO synthase (NOS) is highlighted in plants. Comparedto terrestrial plants, some algae present transcripts encoding the NOS-like enzyme. Amongthem, Klebsormidium nitens the model alga to study the early transition step from aquatic algaeto land plants is found. As mechanisms governing NO synthesis and signaling in green lineageremain unclear, the study of NOS from K. nitens (KnNOS) through (i) the identification ofregulator proteins, (ii) the identification …
Correction des hétérogénéités de champ RF b1+ pour l'optimisation de l'IRM quantitative du sodium dans des aliments réels
2021
Grace aux corrections présentées, des données quantitatives de répartition du sodium sont recueillies sur différents aliments salés pour étudier l'effet matrice (carotte, pâte, viande, pomme de terre), l'effet structure (carotte entière, purée de carotte, potage de carotte) et l'effet moment de salage (pendant la cuisson ou à l'assiette) sur la répartition finale du sel. Dans un second temps ces données seront mises en regard de données de relargage du sodium en bouche et de perception gustative. L'objectif du projet étant de fournir des indications aux familles pour utiliser plus efficacement le sel de table : en préservant leur santé et en respectant leurs attentes gustatives.