Paris West University Nanterre La Défense

About: Paris West University Nanterre La Défense is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Finite element method. The organization has 895 authors who have published 1430 publications receiving 21712 citations.

Female canaries display to songs of early isolated males

Abstract: We tested the sexual responsiveness of female canaries,Serinus canaria, to two sets of different types of male conspecific songs. In each set, three of the male songs had been recorded in a young bird which was isolated at an early age from conspecifics. Each bird was recorded during three stages of the song ontogeny (early plastic songs, late plastic songs and crystallized songs). We used copulation solicitation displays (CSD) as an index of female sexual response. Playbacks were performed during a period of natural sexual responsiveness of the females to song. We demonstrated that, in both experiments, very weak sexual displays of female canaries were recorded to the two stages of ‘isolate’ plastic songs. Each of the two different types of ‘isolate’ crystallized songs elicited high levels of CSD. These levels are not significantly different from the adult domesticated control song. Taken together, these results suggest that even isolate songs may convey sexual information. We discuss prominent acoustic features that must be present to ensure female sexual responses.

Enfoque de redes sociales en las migraciones de América latina hacia Francia

Abstract: We comparatively analyse four types of migratory flows from Latin America to France: the South American exile, the “brain-drain”, the labour migration of a national group and the Haitian Diaspora. The focus of analysis shift from traditional macro social migratory categories to the “meso-level” or the intermediation level, between macro and micro social factors. We point up different types and fonctions of Latin Amercian social networks that illustrate four different uses of the concept of network. Despite its frequently diffuse application and its lack of consensus in social sciences, we conclude that the network approach can provide appropriate knowledge on a wide range of migratory modalities.

Etnoarqueología de las casas Huapula y Jíbaro

Abstract: El valle del Upano, en la alta Amazonia ecuatoriana, esta caracterizado por la presencia de numerosos monticulos artificiales de tierra precolombinos. Edificados y luego abandonados por las sociedades Upano entre 700 a.C. y 400 d.C., algunos de ellos fueron reocupados por grupos Huapula entre 800 y 1200 d.C. La excavacion horizontal de un monticulo revelo un piso habitacional muy bien conservado, autorizando un analisis espacial de las actividades practicadas. El estudio etnoarqueologico de esta habitacion Huapula muestra las grandes similitudes que existen con el modo de habitat actual de los grupos jibaros de la region.

The weak Hawkins-Simon Condition

Abstract: A real square matrix satisfies the weak Hawkins-Simon condition if its leading principal minors are positive (the condition was first studied by the French mathematician Maurice Potron). Three characterizations are given. Simple sufficient conditions ensure that the condition holds after a suitable reorderingof columns. A full characterization of this set of matrices should take into account the group of transforms which leave it invariant. A simple algorithm able, in some cases, to implement a suitable permutation of columns is also studied. The nonsingular Stiemke matrices satisfy the WHS condition after reorderings of both rows and columns.

Fossil fuel subsidies, income inequality and poverty. Evidence from developing countries

Abstract: The past two decades have witnessed widespread attempts to reform fossil fuel subsidies in developing countries. If the reforms are likely to improve economic efficiency, the expected effects on income distribution and poverty are more controversial. This paper reviews the recent literature that examines the impacts of fossil fuel subsidies and their reform on income inequality and poverty. It identifies the different channels that have been explored in the literature and surveys the empirical evidence on the importance ofthese channels in practice. Drawing on diverse country experiences, it also discusses why fossil fuel subsidies are particularly challenging to reform and highlights several ways in which efforts to reform may be feasible and successful.