Lo imaginario espacial y la geografía. En defensa de la geografía de las representaciones.

Sin resume

La différenciation de l’espace urbain de Québec : une application de l’analyse discriminante en géographie urbaine

Puisqu'il n'est pas de connaissance géographique sans différenciation des paysages, la géographie quantitative ne peut se contenter des seules méthodes factorielles. Avec l'analyse discriminante, les poids locaux ne constituent plus l'étape finale, mais le point de départ de l'analyse spatiale. Ainsi procédons-nous à l'étude des espaces socio-économiques et familiaux pour la région métropolitaine de Québec. Loin d'être conforme aux modèles nord-américains, cette ville présente un double aspect: l'un culturel et symbolique, favorisant la conservation de plusieurs secteurs centraux, l'autre économique, entraînant invasions et successions dans les aires périphériques. Même si l'analyse discriminante pose plusieurs problèmes méthodologiques, elle offre au géographe un instrument qui peut servir de support logique pour bâtir une théorie de la ville.Since geography implies the study of space and its influence on human behavior, quantitative geography must encompass more than standard factorial methods. The interpretation of factor loadings and the subsequent description of factor score patterns should thus not constitute the final stage of any spatial analysis but rather the starting point. We study the socio-economic and family « spaces » of the Québec city urban region. We find that the Québec model tends to differ from the classic North American model; symbolic and cultural factors make for a much more coherent and dense centre city while economic factors, as elsewhere on the continent, result in a pattern of concentric zones around the C.B.D. Even though the use of discriminant analysis poses certain methodological problems, we nonetheless found it to be a useful technique for understanding urban social space

A historical overview of the classification, evolution, and dispersion of Leishmania parasites and sandflies

Background The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Methodology and Principal Findings Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? Conclusions and Significance We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites