Résidence, tenure foncière, alliance dans une société bilinéaire (Sérèr du Sine et du Baol, Sénégal)

M. Dupire, A. Lericollais, B. Delpech et J.-M. Gastellu — Residence, Land Tenure and Marriage in a Double-Descent Society: The Serer from the Sine and Baol Regions of Senegal. This society is characterized by virilocal residence, double-descent, and matrilineal inheritance of non-consumable goods. Residential compounds are inherited in both the agnatic and the uterine lines, the relative proportion of each type of succession varying in the four villages under study. A compound may be divided into 'wards', 'kitchens', and, further down, 'uterine huts', each of these units corresponding to a specifie economic function. Starting from K. Gough's five types of residential categories, we define seven different patterns, the form most frequently found being the patrilocal extended family, the elementary family and a composite type of avuncular family, in that order. There is a significant correlation between residence patterns and inheritance of traditional offices. 'Kitchens' differ from compounds insofar as they can be matrilocal and chiefly consist of elementary families. While married sons often live in the same 'kitchen' with their fathers, nephews seldom cohabit with their MB. The 'uterine hut' is the primary unit of economic accumulation. The bilineal pattern of inheritance is also found in the four-level System of land-rights, with a correlation between land-rights and residence. Residential patterns and pre-ferential marriages tend to counterbalance the dispersal of a matrilineage's women resulting from virilocality.Dupire Marguerite, Lericollais André, Delpech Bernard, Gastellu Jean-Marc. Résidence, tenure foncière, alliance dans une société bilinéaire (Serer du Sine et du Baol, Sénégal).. In: Cahiers d'études africaines, vol. 14, n°55, 1974. pp. 417-452

Hedged Monte-Carlo: low variance derivative pricing with objective probabilities

We propose a new `hedged' Monte-Carlo (HMC) method to price financial derivatives, which allows to determine simultaneously the optimal hedge. The inclusion of the optimal hedging strategy allows one to reduce the financial risk associated with option trading, and for the very same reason reduces considerably the variance of our HMC scheme as compared to previous methods. The explicit accounting of the hedging cost naturally converts the objective probability into the `risk-neutral' one. This allows a consistent use of purely historical time series to price derivatives and obtain their residual risk. The method can be used to price a large class of exotic options, including those with path dependent and early exercise features.Comment: LaTeX, 10 pp, 3 eps figures (in text

Maillage fixe et domaine mobile

COMPIEGNE-BU (601592101) / SudocSudocFranceF

Un nouveau périphérique : la flûte virtuelle

International audienceNous décrivons dans cet article un nouveau périphérique, la flûte virtuelle, inspiré de la flûte à bec. Ce périphérique permet de faire converger deux domaines a priori éloignés : la musique et les jeux vidéo

Revue d'intelligence artificielle - Jeu sérieux, révolution pédagogique ou effet de mode ?

National audienceIl y a, au delà des mots « Serious Game », des problèmes qui méritent d'être analysés.Si l'on cherche à définir ce terme en couvrant tous les objets et applications qui s'en réclament, on tombe, non pas dans le vide, mais dans le trop plein. Il ne reste qu'une définition qui convienne : « Tout objet relevant du numérique qui n'est pas destiné aux loisirs et qui utilise soit une technologie soit des principes de conception développés à l'origine pour le jeu vidéo »...

Résidence, tenure foncière, alliance dans une société bilinéaire (Serer du Sine et du Baol, Sénégal).

M. Dupire, A. Lericollais, B. Delpech et J.-M. Gastellu — Residence, Land Tenure and Marriage in a Double-Descent Society: The Serer from the Sine and Baol Regions of Senegal. This society is characterized by virilocal residence, double-descent, and matrilineal inheritance of non-consumable goods. Residential compounds are inherited in both the agnatic and the uterine lines, the relative proportion of each type of succession varying in the four villages under study. A compound may be divided into 'wards', 'kitchens', and, further down, 'uterine huts', each of these units corresponding to a specifie economic function. Starting from K. Gough's five types of residential categories, we define seven different patterns, the form most frequently found being the patrilocal extended family, the elementary family and a composite type of avuncular family, in that order. There is a significant correlation between residence patterns and inheritance of traditional offices. 'Kitchens' differ from compounds insofar as they can be matrilocal and chiefly consist of elementary families. While married sons often live in the same 'kitchen' with their fathers, nephews seldom cohabit with their MB. The 'uterine hut' is the primary unit of economic accumulation. The bilineal pattern of inheritance is also found in the four-level System of land-rights, with a correlation between land-rights and residence. Residential patterns and pre-ferential marriages tend to counterbalance the dispersal of a matrilineage's women resulting from virilocality.Dupire Marguerite, Lericollais André, Delpech Bernard, Gastellu Jean-Marc. Résidence, tenure foncière, alliance dans une société bilinéaire (Serer du Sine et du Baol, Sénégal).. In: Cahiers d'études africaines, vol. 14, n°55, 1974. pp. 417-452

How Are Landscapes under Agroecological Transition Perceived and Appreciated? A Belgian Case Study

peer reviewedAn increasing number of agricultural transition initiatives are taking place, seeking more autonomy and resilience on the farms. This undeniably reshapes the landscape and the delivery of ecosystem services (ES). To date, little research includes the knowledge and perceptions of local communities on rural landscapes in agricultural transition. Yet, farmers shape the landscape and ES delivery, and local inhabitants are directly impacted. The present work aims at assessing the extent to which locals (local inhabitants and farmers) appreciate and view landscapes undergoing agricultural transitions. To do so, questionnaires were submitted to locals enquiring about appreciation and ES perceptions of transitioning landscapes. These landscapes were shown in manipulated photographs simulating an agroecological landscape, a conventional agriculture landscape, and landscapes including each isolated agroecological practice (resulting in six ‘scenarios’). In order to put locals’ perceptions in perspective, the same questionnaire was submitted to ‘ES experts’, and ES perceptions were compared to field-based ES measurements in agroecological and conventional parcels of the same study region. The results show that locals and ES experts appreciate and perceive these scenarios similarly. The agroecological scenario was seen as the most appreciated and the one delivering the most ES, while the conventional one was the least appreciated and seen as the one delivering the least ES. These perceptions of ES delivery partially correspond to the ES field measurements, which showed a similar productivity within agroecological and conventional parcels and more regulating ES in agroecological parcels. We discuss how our results call for the assessment of the multi-performance of agricultural systems in terms of ES rather than focusing on yield only, and how future research addressing agroecological transition should rely on integrated valuations and mixed methods to better embrace the complexity of such transitioning systems

Characterization of the molecular structure of two highly isotactic polypropylenes

Two polypropylenes, PP1 and PP2, produced with different heterogeneous Ziegler-Natta catalytic systems were studied in this work. Preliminary characterization of the non-fractionated materials showed that a low difference in their average tacticity (PP2 > PP1) leads to an important modification of their rigidity properties. In order to establish correlation between the molecular structure parameters and the rigidity properties of these polymers, fractionation of the materials according to crystallizability was performed by means of temperature rising elution fractionation (TREF). Analysis of the fractions of both PP1 and PP2 was carried out by means of C-13 NMR, size exclusion chromatography (SEC), differential scanning calorimetry (DSC) and atomic force microscopy (AFM). The results first showed that TREF does not strictly fractionate PP according to tacticity, but according to the longest crystallizable sequence in a chain. C-13 NMR, SEC and DSC analysis of the fractions demonstrated that the inter-chain tacticity distributions of the polypropylenes is affected by the change of the polymerization conditions, which, in turn, modifies the rigidity properties of the materials. Some results also seem to indicate that the intrachain tacticity distributions are different for the two PP. An AFM study of the elastic modulus was carried out for the first time on the TREE fractions. It showed that the rigidity or the fractions strongly increases as the TREF elution temperature increases in accordance with a concomitant increase of isotacticity and the crytallinity of the fractions. PP2 TREE fractions were, moreover, found to exhibit a higher elastic modulus than PP1 TREF fractions at all elution temperatures. This study allowed us to further identify the TREF fractions that were responsible for differences in rigidity. To summarize, it is shown how the experimentally observed increase of the average rigidity of one of these two polypropylenes can be rationalized via information collected from a TREF fractionation. (C) 2000 Published by Elsevier Science Ltd