Urban and Peri-urban agriculture, social inclusion of migrant population and right to the city:practices in Lisbon and London

Two main questions are addressed in this paper, namely: to what extent can urban and peri-urban agriculture (UPA) contribute to the social inclusion of migrants? And does UPA practised by urban farmers of foreign origin contribute to the expansion of biodiversity in cities? A comparative analysis of current peri-urban agriculture practices in Lisbon and London was carried out in allotment gardens and other spaces far from the centre in and on the edges of these capital cities. In both cases, a significant proportion of the migrant population is involved in two different frameworks: regulated in London and non-regulated in Lisbon. The paper concludes that patterns of social inclusion are quite city specific: urban farming communities from the Cape Verde islands maintain and strengthen community bonds through their activity but this does not necessary lead to better social integration within the wider Portuguese society. In London, migrants of foreign origin become part of an integrated communitarism on an individual basis. Concerning the contribution of peri-urban agriculture to biodiversity, evidence gathered strongly suggests that urban farmers of foreign origin do contribute to broadening biodiversity primarily in Lisbon and to a lesser extent in London. Final observations note to what extent these urban practices contribute to the Right to the City and thus if they are, more broadly, of an emancipatory and transformative nature

Multidimensional simple waves in fully relativistic fluids

A special version of multi--dimensional simple waves given in [G. Boillat, {\it J. Math. Phys.} {\bf 11}, 1482-3 (1970)] and [G.M. Webb, R. Ratkiewicz, M. Brio and G.P. Zank, {\it J. Plasma Phys.} {\bf 59}, 417-460 (1998)] is employed for fully relativistic fluid and plasma flows. Three essential modes: vortex, entropy and sound modes are derived where each of them is different from its nonrelativistic analogue. Vortex and entropy modes are formally solved in both the laboratory frame and the wave frame (co-moving with the wave front) while the sound mode is formally solved only in the wave frame at ultra-relativistic temperatures. In addition, the surface which is the boundary between the permitted and forbidden regions of the solution is introduced and determined. Finally a symmetry analysis is performed for the vortex mode equation up to both point and contact transformations. Fundamental invariants and a form of general solutions of point transformations along with some specific examples are also derived.Comment: 21 page

Agricultura orgânica em áreas urbanas e periurbanas com base na agroecologia.

A agricultura orgânica com base na agroecologia é o mote tecnológico adequado à realidade dos agroecossistemas urbanos. Este artigo ressalta a necessidade de se desenvolver tecnologias e insumos específicos. A partir de experiências com agricultura urbana em diferentes países em desenvolvimento, evidencia-se a necessidade de se buscar capacidades locais e apoio do poder público, especialmente nas iniciativas da sociedade organizada e mobilizada para a produção agrícola urbana

Traditional knowledge and cultural importance of Borassus aethiopum Mart. in Benin: interacting effects of socio-demographic attributes and multi-scale abundance

ResearchBackground: Eliciting factors affecting distribution of traditional knowledge (TK) and cultural importance of plant resources is central in ethnobiology. Socio-demographic attributes and ecological apparency hypothesis (EAH) have been widely documented as drivers of TK distribution, but their synergistic effect is poorly documented. Here, we focused on Borassus aethiopum, a socio-economic important agroforestry palm in Africa, analyzing relationships between the number of use-reports and cultural importance on one hand, and informant socio-demographic attributes (age category and gender) on the other hand, considering the EAH at multi-scale contexts. Our hypothesis is that effects of socio-demographic attributes on use-reports and cultural importance are shaped by both local (village level) and regional (chorological region level) apparency of study species. We expected so because distribution of knowledge on a resource in a community correlates to the versatility in the resource utilization but also connections among communities within a region. Methods: Nine hundred ninety-two face-to-face individual semi-structured interviews were conducted in six villages of low versus high local abundance of B. aethiopum spanning three chorological regions (humid, sub-humid and semiarid) also underlying a gradient of increasing distribution and abundance of B. aethiopum. Number of use-reports and score of importance of uses of B. aethiopum were recorded in six use-categories including medicine, food, handcraft, construction, firewood, and ceremonies and rituals. Data were analyzed using Poisson and ordered logistic modelsinfo:eu-repo/semantics/publishedVersio

Relations entre le parasitisme du rat par

En se plaçant dans des conditions rigoureuses pour essayer de limiter les agressions expérimentales et de respecter la réalisation d’un équilibre endocrine, les expériences réalisées étudient l’influence sur le parasitisme par Strongyloides ratti de l’ovariectomie et des traitements, des rates castrées ou non, par l’œstradiol, l’hexoestrol, le diéthylstilboestrol, la progestérone, l’association mestranol, chlormadinone. Parallèlement, les réactions corticosurrénales (corticostérone) au traitement et au parasitisme sont enregistrées. L’analyse des résultats conduit à penser que la fonction gluco-corticostéroïde du cortex surrénal pourrait être l’un des relais entre les gonades et l’évolution du parasitisme (intensité, déparasitage)

Periodic motions of coupled impact oscillators

International audienceWe study the existence and stability of time-periodic oscillations in a chain of coupled impact oscillators, for rigid impacts without energy dissipation. We formulate the search of periodic solutions as a boundary value problem incorporating unilateral constraints. This problem is solved analytically in the vicinity of the uncoupled limit and numerically for larger coupling constants. Different solution branches corresponding to nonlinear localized modes (breathers) and normal modes are computed