Géographies de la distance : terrains sud-africains

La pratique du terrain dans des aires culturelles différentes de celle dont est originaire le chercheur permet d'interroger nos pratiques, nos présupposés, nos idéologies même dans la mesure où le prisme de la distance — à la fois physique et culturelle — agit comme catalyseur et comme révélateur. En d'autres termes, cette distance agit doublement, en dévoilant l'identité du chercheur comme individu social et politique et en conditionnant les résultats qu'il obtient. Depuis 1994, « mon » terrain est l'Afrique du Sud post-apartheid. L'utilisation, facile et commune, du possessif, ne doit pas ici faire illusion : il serait plus juste d'inverser le sens de ce possessif pour parler, en terre africaine, de possession ou d'obsession par ce terrain. Il me semble que, comme souvent (pour les questions urbaines par exemple), le cas sud-africain peut servir de laboratoire aux interrogations épistémologiques évoquées ci-dessus

Numerical Simulations of Instabilities in Single-Hole Office Elements

An orifice element is commonly used in liquid rocket engine test facilities either as a flow metering device, a damper for acoustic resonance or to provide a large reduction in pressure over a very small distance in the piping system. While the orifice as a device is largely effective in stepping down pressure, it is also susceptible to a wake-vortex type instability that generates pressure fluctuations that propagate downstream and interact with other elements of the test facility resulting in structural vibrations. Furthermore in piping systems an unstable feedback loop can exist between the vortex shedding and acoustic perturbations from upstream components resulting in an amplification of the modes convecting downstream. Such was the case in several tests conducted at NASA as well as in the Ariane 5 strap-on P230 engine in a static firing test where pressure oscillations of 0.5% resulted in 5% thrust oscillations. Exacerbating the situation in cryogenic test facilities, is the possibility of the formation of vapor clouds when the pressure in the wake falls below the vapor pressure leading to a cavitation instability that has a lower frequency than the primary wake-vortex instability. The cavitation instability has the potential for high amplitude fluctuations that can cause catastrophic damage in the facility. In this paper high-fidelity multi-phase numerical simulations of an orifice element are used to characterize the different instabilities, understand the dominant instability mechanisms and identify the tonal content of the instabilities

Extrapulmonary Tuberculosis among Somalis in Minnesota1

To analyze extrapulmonary tuberculosis in Somalis living in Minnesota, we reviewed surveillance and public health case management data on tuberculosis cases in ethnic Somalis in Minnesota from 1993 through 2003. The presence of these recent immigrants substantially affects the local epidemiology and clinical manifestation of tuberculosis

Raquitismo en perros: generalidades, diagnóstico y tratamiento. Una revisión bibliográfica

Objective: to identify rickets in dogs: generalities, diagnosis and treatment. Method: Descriptive documentary. Conclusion: The understanding and management of rickets in dogs has been significantly advanced by research into the relationship between vitamin D, diet, and bone health, as well as the impact of conditions such as chronic kidney disease. However, the variability in dogs' response to diet and supplementation, along with the risk of toxicity from poorly administered supplements, underscores the need for a carefully monitored, individualized approach. Effective prevention and treatment of rickets in dogs requires continuous integration of new knowledge and personalized care to ensure optimal long-term health of the animals.Objetivo: identificar el raquitismo en perros: generalidades, diagnóstico y tratamiento. Método: Descriptivo documental. Conclusión: La comprensión y manejo del raquitismo en perros han avanzado significativamente gracias a la investigación sobre la relación entre la vitamina D, la dieta, y la salud ósea, así como el impacto de condiciones como la enfermedad renal crónica. Sin embargo, la variabilidad en la respuesta de los perros a la dieta y la suplementación, junto con el riesgo de toxicidad por suplementos mal administrados, subraya la necesidad de un enfoque individualizado y cuidadosamente monitoreado. La prevención y tratamiento eficaces del raquitismo en perros requieren una integración continua de nuevos conocimientos y una atención personalizada para garantizar la salud óptima de los animales a largo plazo

Bioactive glass in the treatment of infected pseudoarthrosis of the distal tibia in a thirty five years old man. Case report

Among the most serious complications of modern osteosyntheses are nonunion and infections. The pathology is challenging even for experienced surgeons, and the treatment often ends in failure. Bioactive glass represents an attractive alternative to conventional methods, as it combines a unique chemical formula (53% SiO2, 23% Na2O, 20% CaO and 4% P2O) that is osteoinductive and increases the local pH as well as the osmotic pressure, which leads to its antibacterial effect. Herein, we present a clinical case of a 35-year-old man with infected pseudarthrosis of the distal tibia treated with bioactive glass. The excellent clinical and radiological results at the 6-month follow-up and positive data from the literature lead us to be optimistic about the treatment of these severe conditions

Entrepreneurs transnationaux et commerce d’exportation de véhicules d’occasion : la filière Bruxelles-Cotonou

Cet article s’intéresse au profil migratoire des importateurs de véhicules d’occasion de la filière Bruxelles-Cotonou. Ces deux villes occupent une position de places marchandes au sein d’une filière commerciale transnationale. Après une rapide revue de la littérature, le concept d’entrepreneur migrant est mobilisé pour décrire les importateurs de véhicules. Les nombreuses différences observées entre les importateurs libanais et béninois permettent une analyse comparative. Une discussion théorique est engagée sur les concepts les plus à même de décrire le profil migratoire de ces entrepreneurs. Il apparaît ainsi que les importateurs libanais ont un profil de diaspora commerciale mettant à profit une appartenance ethnique commune pour développer leur activité économique. Les importateurs béninois, quant à eux, s’apparentent davantage à des entrepreneurs transfrontaliers actifs au sein d’un territoire circulatoire.This contribution focuses on the migratory profiles of second-hand cars importers operating between Brussels, Belgium and Cotonou, Benin. Those two cities are business hubs in a transnational import-export business. After a quick state of the art, the concept of migrant entrepreneur is used to describe those second-hand cars importers. Numerous differences between Lebanese and Beninese importers allow us to draft a comparative analysis between their migratory profiles. On the one hand, Lebanese importers have a status of trade diaspora. They use their common ethnic belonging to address technical challenges linked to a common commercial activity. On the other hand, native Beninese car importers have the status of cross-border entrepreneurs working in a territory of movement between various business hubs.Esta contribución se interesa en el perfil migratorio de importadores de vehículos usados de la sucursal en Bruselas, en Cotonou. Ambas ciudades ocupan una posición en el sector comercial a nivel transnacional. Después de una breve revisión de la literatura, el concepto de empresario migrante será empleado para describir a los importadores de vehículos. Las diversas diferencias observadas entre los importadores libaneses y benineses permiten un análisis comparativo. Una discusión teórica será emprendida sobre los conceptos clave a fin de describir el perfil migratorio de estos empresarios. De esta forma, pareciera que los importadores libaneses tienen un perfil de diáspora comercial aprovechando una etnicidad común para desarrollar su actividad económica, mientras que, por su lado, los importadores benineses parecen más empresarios transfronterizos activos al interior de un territorio circulatorio