Search results for "wt"
showing 10 items of 5424 documents
Impact of the growth of different maize genotypes on arbuscular mycorrhizal fungi
2001
International audience
Services provided by soil microorganisms to improve plant phosphate nutrition
2022
Since the first Green Revolution, agricultural practices have been based on the massive use of synthetic fertilisers and plant protection products. Since then, global consumption of phosphate fertilisers has more than tripled, reaching 47 million tonnes in 2019. Current projections estimate that phosphate rock stocks (natural phosphorus resources for fertiliser production) could be depleted within the next century, leading us to change our agricultural practices. In soils, P is mainly present in complexed forms that are not easily accessible to plants. To reduce the use of phosphate fertilisers, it is necessary to make this complexed phosphate accessible to plants. This can be done by benef…
Spatial distribution of ammonia-oxidizing bacteria and archaea across a 44-hectare farm related to ecosystem functioning
2011
Characterization of spatial patterns of functional microbial communities could facilitate the understanding of the relationships between the ecology of microbial communities, the biogeochemical processes they perform and the corresponding ecosystem functions. Because of the important role the ammonia-oxidizing bacteria (AOB) and archaea (AOA) have in nitrogen cycling and nitrate leaching, we explored the spatial distribution of their activity, abundance and community composition across a 44-ha large farm divided into an organic and an integrated farming system. The spatial patterns were mapped by geostatistical modeling and correlations to soil properties and ecosystem functioning in terms …
Economies d'agglomération et configurations spatiales dans les espaces ruraux
1997
The question to be addressed here is that of the agglomeration/dispersion forces that are likely to account for the location of people and jobs in rural areas and the way they explain spatial patterns in rural areas depending on urban influence. Economic geography models may provide suitable tools with which to investigate the organization of rural areas. We first review these models, focusing on dispersion forces, which rest basically on land consumption and transport costs. We suggest then a set of hypotheses concerning the main forces at work in rural areas. Intensity of agglomeration economies is hypothesized to be related to the urban size, which in turn induces increasing land rents a…
Dendro-archaeological contribution to the history of forest exploitation. The case of the Gallo-Roman settlement of Odenburg (Alsace, France) between…
2010
L'immigration dans quelques communes de la banlieue ouest : Asnières, Nanterre et Puteaux de 1830 à 1930
1990
A study of immigration for the period 1 830-1 930 for three communes in the western suburbs of Paris has been undertaken with the aid of official marriage certificates. The study tends to show that each suburban commune's immigrants, coming primarily from the provinces and secondarily from Paris, have been chosen to some extent since they reflect the economic activities and the social composition of the population of the commune of arrival. This selection occuring within national migration streams seems to favour the migrants insertion, at least until the beginning of the twentieth century.
TRIPS Agreement: From Minimum Standards to Double Standards of Intellectual Property Rights Protection in North-South Relations
2015
The WTO Trips agreement's basic objective of establishing minimum international standards for IP rights protection is based on a restrictive " one-fits-all " approach that denies the right to enact or not to enact intellectual property rights provisions to developing countries and least developed countries and restrict their ability to effectively adapt national laws to their own socioeconomic environment and development level. Developed countries had widely benefited from this privilege when no minimum binding standards of intellectual property existed in multilateral relations. The Trips agreement stabilizes the strong inequalities in terms of bargaining power between rich and poor countr…
Human capital and RD Driven Growth: analyse for France at regional level on the long run
2012
At the root of the Lisbon goal, for Europe, is placed the awareness for advocating a close link between growth and dissemination of advanced knowledge and innovation, on the one hand, and raising in general endowments in human capital, on the other hand, as to have power over the development of non-specific skills and boost efficiency. Much work in literature also stressed the interest of the position concerning traditional activities in the geography of innovation and links, in the long term, between the spatial distribution of longestablished skills and knowledge creation. Following Jones, in this approach, for which contribution to R&D and innovation explains half of the increase in weal…
Capital humain et croissance : l'apport des enquêtes internationales sur les acquis des élèves
2006
The estimation of the relationship between education and economic growth is marked by contradictions. These contradictions underline the lack of precision characterising indicators of human capital. This paper constructs new indicators based on a pool of international surveys concerning pupil assessment. Thus, our new database, which includes 105 countries, makes it possible to confirm or not the positive relationship between education and growth. Taking into account the endogeneity of education, we measure a positive effect of qualitative indicators of human capital and the growth of countries between 1960 and 2000. The contribution of education to growth therefore appears significant,…
Economic Returns to Education in France: OLS and Instrumental Variable Estimations
2013
En ligne sur : http://121.52.153.179/JOURNAL/LJE%20VOL%2018-2/Bhatti,%20Bourdon%20and%20Aslam.pdf; International audience; This article estimates the economic returns to schooling as well as analyzing other explanatory factors for the French labor market. It addresses the issue of endogeneity bias and proposes two new instruments for use in the instrumental variable two-stage least squares technique. Our results show that the proposed instruments are relevant and adequate, based on evidence from the available literature. After using the proposed instruments, we find that the OLS coefficients for schooling are biased downwards. Finally, we choose between the two proposed instruments.