1,082 research outputs found
Development at the border : policies and national integration in Côte d'Ivoire and its neighbors
En appliquant plusieurs méthodes de régressions par discontinuité à un ensemble d'enquêtes auprès des ménages pour les années 1980 et 1990, nous examinons si la richesse macroéconomique de la Côte d'Ivoire se constatait aux frontières avec les pays voisins. A la frontière du Ghana et à la fin des années 1980, de larges discontinuités sont détectées en matière de consommation, de retard de croissance infantile, et d'accès à l'électricité ou à l'eau. Les discontinuités frontalières de consommation peuvent être expliquées par les différences de politiques concernant les cultures d'exportation (café et cacao). Quand ces politiques ont convergé dans les années 1990, seules les différences d'infrastructures rurales ont persisté. Dans le Nord, le revenu des cultures d'exportation (coton) engendrait aussi une différence en matière de consommation et de nutrition (cas du Mali). D'un côté, de larges différences de bien-être peuvent s'observer aux frontières divisant des pays africains, malgré leur supposée porosité. D'un autre côté, les discontinuités frontalières semblent refléter l'impact de politiques publiques réversibles, plutôt que des caractéristiques institutionnelles intangibles
Introduction générale. Circulations de normes et réseaux d'acteurs. La gouvernance internationale de l'environnement entre fragmentation et défragmentation
International audienceLa gouvernance internationale de l'environnement s'est construite progressivement autour de différentes questions se traduisant par l'émergence de multiples espaces juridiques et institution-nels relativement autonomes. Les chercheurs, et notamment Stephan Krasner, ont produit la notion de « régime » pour les décrire (Krasner, 1983). Ce faisant, ils ont probablement aussi contribué à leur construction. Originaire de la science politique, la notion de « régime » a été adoptée par les juristes qui l'ont trouvée utile. Cette expression permet de commodément désigner, par exemple, une convention internationale de protection de l'environnement, les institutions créées en son sein et l'ensemble de son droit dérivé, ainsi que d'éventuels mécanismes financiers. En englobant sous un même vocable un ensemble de normes et d'institutions qui vont bien au-delà d'un traité institu-tif, la notion de « régime » permet ainsi de décrire une réalité qui n'est pas ou très imparfaitement nommée en droit et regroupe un ensemble parfois disparate d'organisations, d'organes et de normes internationales traitant d'une question donnée. Sociologues, politistes, juristes, économistes, se sont attachés à mieux cerner l'émergence et la formation de ces régimes, leur fonctionnement (par le biais d'une décomposition analytique en identifiant les variables et les « constituants ») ainsi que leurs résultats (Young, 1989 ; Birnie, Boyle, 1992 ; Barret, 2005). Orientés vers la résolution d'un « problème » soit problem driven 3 , ces régimes spécialisés ont proliféré au gré de l'identification de nouvelles menaces et de nouveaux problèmes à résoudre. Ils se comptent aujourd'hui par dizaines, si bien que la question de la coordination sinon de la cohérence de ce paysage fragmenté s'est rapidement posée. La multiplication des régimes a entrainé par défi-nition des concurrences, collisions, doubles emplois, de plus en plus fréquents. À cela s'est ajoutée la prise de conscience que les enjeux environnementaux sont étroitement interconnectés, comme le montrent les relations entre la lutte contre les changements climatiques d'une part et la protection de la couche d'ozone, la conservation de la biodiversité, la désertification, la protection des forêts ou des océans d'autre part. Dès lors, une gouvernance trop fragmentée ne peut être effective, car elle risque de conduire à défaire d'un côté ce que l'on fait de l'autre (Bierman, 2012). En d'autres termes, « in order to govern processes of complex change, complexity in the external world must be matched by complexity in the governance system » (Duit, 2010). 3 Avec ce que cela suppose par rapport au fait que les acteurs en présence ne sont pas toujours d'accord sur la formulation du problème et l'importance à lui accorder
from new space to big space how commercial space dream is becoming a reality
Abstract New space is a misleading expression. Many new trends steer the evolution of space activities. Development of commercial space, with start-ups and space ventures, is one of the most visible trends in space. Stimulated by the first initiatives related to space tourism, access to space and the growing use of small satellites, space activities have attracted new entrepreneurs, both start-ups and big web actors with substantial investment capacity. This revolution started in the Silicon Valley and spread worldwide. Start-ups have attracted around $21.8 billion of investment from 2000 to 2018. It is far below the annual institutional budgets but the pace gained momentum since 2006 and specially 2012. Between teenage crisis and age of reason, New space is now old: the first start-ups shall confirm their promises, while new players pop up and try to find their way. It shakes the legacy players but they demonstrate resilience and adaptation capacity. It is now the right time to take stock of the first lessons learnt. Start-ups disrupt the established industry? Instead of a simplistic shortcut, this paper reports an "organisational ecology" study. With a deliberate industrial viewpoint, its ambition is to help understanding complex evolutions in the space ecosystem. The first part of the paper introduces the current ecosystem, its actors, the key trends and the main types of activities. Through facts and figures on technology, investments and markets, the second part reviews how "new space" trends is preparing the advent of big space. The third part summarises lessons from other industries and typical disruption scenarios that could affect space activities. The drivers of New space are discussed in section four. The last part is a foresight exercise, discussing possible evolutions and impacts, threats and opportunities. The decisive role of institutional actors and the « new New space » with more and more space-faring nations is also highlighted. Something big is happening in space. While it is too early to depict the new landscape, this study shows that the future picture will not be black and white but more colourful. The size and the age of the company are less important than agility, mindset, ability to manage risks and to cooperate. A big vision for the future, from entrepreneurs or from nations, is also needed
Formally verified optimizing compilation in ACG-based flight control software
International audienceThis work presents an evaluation of the CompCert formally specified and verified optimizing compiler for the development of DO-178 level A flight control software. First, some fundamental characteristics of flight control software are presented and the case study program is described. Then, the use of CompCert is justified: its main point is to allow optimized code generation by relying on the formal proof of correctness and additional compilation information instead of the current un-optimized generation required to produce predictable assembly code patterns. The evaluation of its performance (measured using WCET and code size) is presented and the results are compared to those obtained with the currently used compiler
The use of distributed hydrological models for the Gard 2002 flash flood event: Analysis of associated hydrological processes
Summary This paper presents a detailed analysis of the September 8-9, 2002 flash flood event in the Gard region (southern France) using two distributed hydrological models: CVN built within the LIQUID® hydrological platform and MARINE. The models differ in terms of spatial discretization, infiltration and water redistribution representation, and river flow transfer. MARINE can also account for subsurface lateral flow. Both models are set up using the same available information, namely a DEM and a pedology map. They are forced with high resolution radar rainfall data over a set of 18 sub-catchments ranging from 2.5 to 99Â km2 and are run without calibration. To begin with, models simulations are assessed against post field estimates of the time of peak and the maximum peak discharge showing a fair agreement for both models. The results are then discussed in terms of flow dynamics, runoff coefficients and soil saturation dynamics. The contribution of the subsurface lateral flow is also quantified using the MARINE model. This analysis highlights that rainfall remains the first controlling factor of flash flood dynamics. High rainfall peak intensities are very influential of the maximum peak discharge for both models, but especially for the CVN model which has a simplified overland flow transfer. The river bed roughness also influences the peak intensity and time. Soil spatial representation is shown to have a significant role on runoff coefficients and on the spatial variability of saturation dynamics. Simulated soil saturation is found to be strongly related with soil depth and initial storage deficit maps, due to a full saturation of most of the area at the end of the event. When activated, the signature of subsurface lateral flow is also visible in the spatial patterns of soil saturation with higher values concentrating along the river network. However, the data currently available do not allow the assessment of both patterns. The paper concludes with a set of recommendations for enhancing field observations in order to progress in process understanding and gather a larger set of data to improve the realism of distributed models
Wipe sampling procedure coupled to LC-MS/MS analysis for the simultaneous determination of 10 cytotoxic drugs on different surfaces
A simple wipe sampling procedure was developed for the surface contamination determination of ten cytotoxic drugs: cytarabine, gemcitabine, methotrexate, etoposide phosphate, cyclophosphamide, ifosfamide, irinotecan, doxorubicin, epirubicin and vincristine. Wiping was performed using Whatman filter paper on different surfaces such as stainless steel, polypropylene, polystyrol, glass, latex gloves, computer mouse and coated paperboard. Wiping and desorption procedures were investigated: The same solution containing 20% acetonitrile and 0.1% formic acid in water gave the best results. After ultrasonic desorption and then centrifugation, samples were analysed by a validated liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in selected reaction monitoring mode. The whole analytical strategy from wipe sampling to LC-MS/MS analysis was evaluated to determine quantitative performance. The lowest limit of quantification of 10ng per wiping sample (i.e. 0.1ngcm−2) was determined for the ten investigated cytotoxic drugs. Relative standard deviation for intermediate precision was always inferior to 20%. As recovery was dependent on the tested surface for each drug, a correction factor was determined and applied for real samples. The method was then successfully applied at the cytotoxic production unit of the Geneva University Hospitals pharmacy. Figure Wipe sampling procedure for the determination of cytotoxic drug
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