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See detailThe Fish Migrate and so Must We': the Relationship between International and Internal Environmental Mobility in a Senegalese Fishing Community
Zickgraf, Caroline ULg

Conference (2015, April)

In 2008, the UN designated Saint-Louis “the city most threatened by rising sea levels in the whole of Africa”. The people of Guet Ndar, a densely populated fishing quarter, are coping with environmental ... [more ▼]

In 2008, the UN designated Saint-Louis “the city most threatened by rising sea levels in the whole of Africa”. The people of Guet Ndar, a densely populated fishing quarter, are coping with environmental challenges on two fronts: 1) coastal erosion and intensifying storms have destroyed sea-front homes, and, 2) overfishing and climate change’s maritime impacts are making local fishing less feasible as a livelihood strategy. Based on a local case study, this paper examines Guet Ndarian migration as an adaptive response to environmental risks and more specifically climate change: 1) through the intensification of fishing migration to Mauritania, and 2) through home construction on the mainland away from the encroaching sea. Although these population movements respond to different environmental challenges, this paper identifies their enmeshment as the former facilitates the latter. Furthermore, it embeds these migratory dynamics in their socio-economic context and applies mobility and transnational paradigms to environmentally vulnerable areas. [less ▲]

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See detailMise en perspective de l'après-midi de rencontre avec les maîtres de stages du Cifen
Simons, Germain ULg

in Didactiques en pratique (2015), 1

Ce texte est le discours du Président du Cifen qui a été prononcé à l'occasion de la première journée officielle de rencontre entre le Centre et les maitres de stages (5 novembre 2014). Ce discours ... [more ▼]

Ce texte est le discours du Président du Cifen qui a été prononcé à l'occasion de la première journée officielle de rencontre entre le Centre et les maitres de stages (5 novembre 2014). Ce discours succinct reprend la question qui a servi de fil rouge à cette journée : "Comment collaborer efficacement pour accompagner au mieux nos stagiaires ?" et en détaille chaque composante. [less ▲]

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See detailGAIMS: a tool specifically developed for the clinical gait analysis of patients with multiple sclerosis
Pierard, Sébastien ULg; Phan-Ba, Rémy; Giet, Amaury et al

Poster (2015, April)

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See detailDoes the soil’s effective hydraulic conductivity adapt in order to obey the Maximum Entropy Production principle? A lab experiment
Westhoff, Martijn ULg; Zehe, Erwin; Erpicum, Sébastien ULg et al

Conference (2015, April)

The Maximum Entropy Production (MEP) principle is a conjecture assuming that a medium is organized in such a way that maximum power is subtracted from a gradient driving a flux (with power being a flux ... [more ▼]

The Maximum Entropy Production (MEP) principle is a conjecture assuming that a medium is organized in such a way that maximum power is subtracted from a gradient driving a flux (with power being a flux times its driving gradient). This maximum power is also known as the Carnot limit. It has already been shown that the atmosphere operates close to this Carnot limit when it comes to heat transport from the Equator to the poles, or vertically, from the surface to the atmospheric boundary layer. To reach this state close to the Carnot limit, the effective thermal conductivity of the atmosphere is adapted by the creation of convection cells (e.g. wind). The aim of this study is to test if the soil’s effective hydraulic conductivity also adapts itself in such a way that it operates close to the Carnot limit. The big difference between atmosphere and soil is the way of adaptation of its resistance. The soil’s hydraulic conductivity is either changed by weathering processes, which is a very slow process, or by creation of preferential flow paths. In this study the latter process is simulated in a lab experiment, where we focus on the preferential flow paths created by piping. Piping is the process of backwards erosion of sand particles subject to a large pressure gradient. Since this is a relatively fast process, it is suitable for being tested in the lab. In the lab setup a horizontal sand bed connects two reservoirs that both drain freely at a level high enough to keep the sand bed always saturated. By adding water to only one reservoir, a horizontal pressure gradient is maintained. If the flow resistance is small, a large gradient develops, leading to the effect of piping. When pipes are being formed, the effective flow resistance decreases; the flow through the sand bed increases and the pressure gradient decreases. At a certain point, the flow velocity is small enough to stop the pipes from growing any further. In this steady state, the effective flow resistance of the sand bed will be compared with the theoretical optimal flow resistance obtained with the MEP principle. For this study, different magnitudes of the forcing will be tested, while also the effect of dry spells will be explored. [less ▲]

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See detailTeaching and learning Quaternary prevention
Gomes, Luis Enrique; Gusso, Gustavo; Jamoulle, Marc ULg

in Revista Brasileira de Medicina de Família e Comunidade (2015)

This article presents an overview of different techniques and skills required for teaching and learning quaternary prevention (P4). It adopts the Expertise Model that defines the competences required in ... [more ▼]

This article presents an overview of different techniques and skills required for teaching and learning quaternary prevention (P4). It adopts the Expertise Model that defines the competences required in P4 for each level: novice, competent, proficient, and expert. This should be used as a step-wise roadmap for teachers in order to achieve high standard levels of performance. This is complemented by a list of methods used in teaching and assessment of learners’ performance and competence. By covering a range of learning and teaching issues, those who aim to teach quaternary prevention can explore the proposed framework. Quaternary prevention is a research and teaching fertile medical field that requires the integration of different areas such as health service organization, epidemiology, communication skills, and andragogy either at the macro or the micro levels health related activities. [less ▲]

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See detailBiogenic Volatile Organic Compound (BVOC) emissions from agricultural crop species: is guttation a possible source for methanol emissions following light/dark transition?
Mozaffar, Ahsan ULg; Amelynck, Crist; Bachy, Aurélie ULg et al

in Geophysical Research Abstracts (2015, April), 17(EGU2015-2110-1),

In the framework of the CROSTVOC (CROp STress VOC) project, the exchange of biogenic volatile organic compounds (BVOCs) between two important agricultural crop species, maize and winter wheat, and the ... [more ▼]

In the framework of the CROSTVOC (CROp STress VOC) project, the exchange of biogenic volatile organic compounds (BVOCs) between two important agricultural crop species, maize and winter wheat, and the atmosphere has recently been measured during an entire growing season by using the eddy covariance technique. Because of the co-variation of BVOC emission drivers in field conditions, laboratory studies were initiated in an environmental chamber in order to disentangle the responses of the emissions to variations of the individual environmental parameters (such as PPFD and temperature) and to diverse abiotic stress factors. Young plants were enclosed in transparent all-Teflon dynamic enclosures (cuvettes) through which BVOC-free and RH-controlled air was sent. BVOC enriched air was subsequently sampled from the plant cuvettes and an empty cuvette (background) and analyzed for BVOCs in a high sensitivity Proton-Transfer Reaction Mass Spectrometer (hs-PTR-MS) and for CO2 in a LI-7000 non-dispersive IR gas analyzer. Emissions were monitored at constant temperature (25 °C) and at a stepwise varying PPFD pattern (0-650 µmol m-2 s-1). For maize plants, sudden light/dark transitions at the end of the photoperiod were accompanied by prompt and considerable increases in methanol (m/z 33) and water vapor (m/z 39) emissions. Moreover, guttation droplets appeared on the sides and the tips of the leaves within a few minutes after light/dark transition. Therefore the assumption has been raised that methanol is also coming out with guttation fluid from the leaves. Consequently, guttation fluid was collected from young maize and wheat plants, injected in an empty enclosure and sampled by PTR-MS. Methanol and a large number of other compounds were observed from guttation fluid. Recent studies have shown that guttation from agricultural crops frequently occurs in field conditions. Further research is required to find out the source strength of methanol emissions by this guttation phenomenon in real environmental conditions. [less ▲]

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See detailTowards a Middlebox Policy Taxonomy: Path Impairments
Edeline, Korian ULg; Donnet, Benoît ULg

in International Workshop on Network Science for Communication Networks (NetSciCom): Hong Kong April 27 2015 (2015, April)

Recent years have seen the rise of middleboxes, such as firewalls, NATs, proxies, or Deep Packet Inspectors. Those middleboxes play an important role in today's Internet, including enterprise networks and ... [more ▼]

Recent years have seen the rise of middleboxes, such as firewalls, NATs, proxies, or Deep Packet Inspectors. Those middleboxes play an important role in today's Internet, including enterprise networks and cellular networks. However, despite their huge success in modern network architecture, they have a negative impact on the Internet evolution as they can slow down the TCP protocol evolution and its extensions. Making available a summary of the potential middlebox network interferences is of the highest importance as it could allow researchers to confront their new transport protocol to potential issues caused by middleboxes. And, consequently, allowing again innovation in the Internet. This is exactly what we tackle in this paper. We propose a path impairment oriented middlebox taxonomy that aims at categorizing the initial purpose of a middlebox policy as well as its potential unexpected complications. Based on a measurement campaign on IPv4 and IPv6 networks, we confront our taxonomy to the real world. Our dataset is freely available. [less ▲]

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See detailClimatic risk assessment to improve nitrogen fertilisation recommendations : A strategic crop model-based approach
Dumont, Benjamin ULg; Basso, Bruno; Bodson, Bernard ULg et al

in European Journal of Agronomy (2015), 65(10-17),

Within the context of nitrogen (N) management, since 1950, with the rapid intensification of agriculture, farmers have often applied much larger fertiliser quantities than what was required to reach the ... [more ▼]

Within the context of nitrogen (N) management, since 1950, with the rapid intensification of agriculture, farmers have often applied much larger fertiliser quantities than what was required to reach the yield potential. However, to prevent pollution of surface and groundwater induced by nitrates, The European Community launched The European Nitrates Directive 91/6/76/EEC. In 2002, in Wallonia (Belgium), the Nitrates Directive has been transposed under the Sustainable Nitrogen Management in Agriculture Program (PGDA), with the aim of maintaining productivity and revenue for the country’s farmers, while reducing the environmental impact of excessive N application. A feasible approach for addressing climatic uncertainty lies in the use of crop models such as the one commonly known as STICS (simulateur multidisciplinaire pour les cultures standard). These models allow the impact on crops of the interaction between cropping systems and climatic records to be assessed. Comprehensive historical climatic records are rare, however, and therefore the yield distribution values obtained using such an approach can be discontinuous. In order to obtain better and more detailed yield distribution information, the use of a high number of stochastically generated climate time series was proposed, relying on the LARS-Weather Generator. The study focused on the interactions between varying N practices and climatic conditions. Historically and currently, Belgian farmers apply 180 kg N ha−1, split into three equal fractions applied at the tillering, stem elongation and flag-leaf stages. This study analysed the effectiveness of this treatment in detail, comparing it to similar practices where only the N rates applied at the flag-leaf stage were modified. Three types of farmer decision-making were analysed. The first related to the choice of N strategy for maximising yield, the second to obtaining the highest net revenue, and the third to reduce the environmental impact of potential N leaching, which carries the likelihood of taxation if inappropriate N rates are applied. The results showed reduced discontinuity in the yield distribution values thus obtained. In general, the modulation of N levels to accord with current farmer practices showed considerable asymmetry. In other words, these practices maximised the probability of achieving yields that were at least superior to the mean of the distribution values, thus reducing risk for the farmers. The practice based on applying the highest amounts (60–60–100 kg N ha−1) produced the best yield distribution results. When simple economical criteria were computed, the 60–60–80 kg N ha−1 protocol was found to be optimal for 80–90% of the time. There were no statistical differences, however, between this practice and Belgian farmers’ current practice. When the taxation linked to a high level of potentially leachable N remaining in the soil after harvest was considered, this methodology clearly showed that, in 3 years out of 4, 30 kg N ha−1 could systematically be saved in comparison with the usual practice. [less ▲]

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See detailModelling carbon fluxes of forest and grassland ecosystems in Western Europe using the CARAIB dynamic vegetation model: evaluation against eddy covariance data.
Henrot, Alexandra-Jane ULg; François, Louis ULg; Dury, Marie ULg et al

in Geophysical Research Abstracts (2015, April), 17

Eddy covariance measurements are an essential resource to understand how ecosystem carbon fluxes react in response to climate change, and to help to evaluate and validate the performance of land surface ... [more ▼]

Eddy covariance measurements are an essential resource to understand how ecosystem carbon fluxes react in response to climate change, and to help to evaluate and validate the performance of land surface and vegetation models at regional and global scale. In the framework of the MASC project (« Modelling and Assessing Surface Change impacts on Belgian and Western European climate »), vegetation dynamics and carbon fluxes of forest and grassland ecosystems simulated by the CARAIB dynamic vegetation model (Dury et al., iForest - Biogeosciences and Forestry, 4:82-99, 2011) are evaluated and validated by comparison of the model predictions with eddy covariance data. Here carbon fluxes (e.g. net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (RECO)) and evapotranspiration (ET) simulated with the CARAIB model are compared with the fluxes measured at several eddy covariance flux tower sites in Belgium and Western Europe, chosen from the FLUXNET global network (http://fluxnet.ornl.gov/). CARAIB is forced either with surface atmospheric variables derived from the global CRU climatology, or with in situ meteorological data. Several tree (e.g. Pinus sylvestris, Fagus sylvatica, Picea abies) and grass species (e.g. Poaceae, Asteraceae) are simulated, depending on the species encountered on the studied sites. The aim of our work is to assess the model ability to reproduce the daily, seasonal and interannual variablility of carbon fluxes and the carbon dynamics of forest and grassland ecosystems in Belgium and Western Europe. [less ▲]

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See detailImproving energy partitioning and the nighttime energy balance by implementation of a multi-layer energy budget in ORCHIDEE-CAN
Chen, Yiying; Ryder, James; Naudts, Kim et al

in Geophysical Research Abstracts (2015, April), 17

Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions as it determines the energy and scalar exchanges between land surface and overlay air mass. In ... [more ▼]

Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions as it determines the energy and scalar exchanges between land surface and overlay air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget (Ryder et al., 2014) in a land surface model, ORCHIDEE-CAN (Naudts et al., 2014), which simulates canopy structure and can be coupled to an atmospheric model using an implicit procedure. Furthermore, a vertical discrete drag parametrization scheme was also incorporated into this model, in order to obtain a better description of the sub-canopy wind profile simulation. Site level datasets, including the top-of-the-canopy and sub-canopy observations made available from eight flux observation sites, were collected in order to conduct this evaluation. The geo-location of the collected observation sites crossed climate zones from temperate to boreal and the vegetation types included deciduous, evergreen broad leaved and evergreen needle leaved forest with maximum LAI ranging from 2.1 to 7.0. First, we used long-term top-of-the-canopy measurements to analyze the performance of the current one-layer energy budget in ORCHIDEE-CAN. Three major processes were identified for improvement through the implementation of a multi-layer energy budget: 1) night time radiation balance, 2) energy partitioning during winter and 3) prediction of the ground heat flux. Short-term sub-canopy observations were used to calibrate the parameters in sub-canopy radiation, turbulence and resistances modules with an automatic tuning process following the maximum gradient of the user-defined objective function. The multi-layer model is able to capture the dynamic of sub-canopy turbulence, temperature and energy fluxes with imposed LAI profile and optimized parameter set at a site level calibration. The simulation result shows the improvement both on the nighttime energy balance and energy partitioning during winter and presents a better Taylor skill score, compared to the result from single layer simulation. The importance of using the multi-layer energy budget in a land surface model for coupling to the atmospheric model will also be discussed in this presentation. [less ▲]

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See detailMeasuring and modelling the intra-day variability of the CO2 & CO2 vertical soil profile production in a Scots pine forest
Longdoz, Bernard; Goffin, Stéphanie; Parent, Florian et al

in Geophysical Research Abstracts (2015, April), 17

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See detailThe CROSTVOC project – an integrated approach to study the effect of stress on BVOC exchange between agricultural crops and grassland ecosystems and the atmosphere
Amelynck, Crist; Heinesch, Bernard ULg; Aubinet, Marc ULg et al

in Geophysical Research Abstracts (2015, April), 17

Global changes in atmospheric composition and climate are expected to affect BVOC exchange between terrestrial vegetation and the atmosphere through changes in the drivers of constitutive BVOC emissions ... [more ▼]

Global changes in atmospheric composition and climate are expected to affect BVOC exchange between terrestrial vegetation and the atmosphere through changes in the drivers of constitutive BVOC emissions and by increases in frequency and intensity of biotic or abiotic stress episodes. Indeed, several studies indicate changes in the emission patterns of constitutive BVOCs and emission of stress-induced BVOCs following heat, drought and oxidative stress, amongst others. Relating changes in BVOC emissions to the occurrence of one or multiple stressors in natural environmental conditions is not straightforward and only few field studies have dealt with it, especially for agricultural crop and grassland ecosystems. The CROSTVOC project aims to contribute in filling this knowledge gap in three ways. Firstly, it aims at performing long-term BVOC emission field measurements from maize (Zea mays L.) and wheat (Triticum aestivum L.), two important crop species on the global scale, and from grassland. This should lead to a better characterization of (mainly oxygenated) BVOC emissions from these understudied ecosystems, allowing a better representation of those emissions in air quality and atmospheric chemistry and transport models. BVOC fluxes are obtained by the Disjunct Eddy Covariance by mass scanning (DEC-MS) technique, using a hs-PTR-MS instrument for BVOC analysis. Secondly, the eddy covariance BVOC flux measurements (especially at the grassland site) will be accompanied by ozone flux, chlorophyll fluorescence, photosynthesis and soil moisture measurements, amongst others, to allow linking alterations in BVOC emissions to stress episodes. Simultaneously, automated dynamic enclosures will be deployed in order to detect specific abiotic and biotic stress markers by PTR-MS and identify them unambiguously by GC-MS. Thirdly, the field measurements will be accompanied by laboratory BVOC flux measurements in an environmental chamber in order to better disentangle the responses of the BVOC emissions to driving factors that co-occur in field conditions and to determine the influence of single abiotic stressors on BVOC emissions. Next to a general presentation, some preliminary results of the project will be shown. [less ▲]

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See detailDiurnal and seasonal variability of CO2 fluxes over a degraded Woodland under a Sudanian climate in Northern Benin (West Africa)
Ago, Expédit Evariste; Serça, Dominique; Agbossou, Euloge Kossi et al

in Geophysical Research Abstracts (2015, April), 17

Turbulent CO2 exchanges over a degraded woodland were measured during 17 months (from November 2005 to March 2007) by an eddy-covariance system at Nangatchori in the northern part of Benin, West Africa ... [more ▼]

Turbulent CO2 exchanges over a degraded woodland were measured during 17 months (from November 2005 to March 2007) by an eddy-covariance system at Nangatchori in the northern part of Benin, West Africa. The site (Lat 9.65°N, Long 1.74°E, Alt: 432 m), under a Sudanian climate, is one of the sites that were equipped in the framework of the international AMMA-CATH program. The site was highly disturbed during preceding years by illegal tree logging, agricultural activities, cattle pasture, and bushfire. The footprint area is mainly formed by herbs and crops with some sparse shrubs and trees. Fluxes data were completed during the same period by meteorological measurements made at the Nalohou site located approximately 20 km from Nangatchori, and by an inventory of dominating species on 1km2 area around the tower during the wet season. Fluxes response to climatic variables was analyzed. The annual drought and moisture cycle was found to be the main controlling factor of the ecosystem dynamics. A very clear response of CO2 fluxes to PPFD appears, but is different according to seasons. During wet season, CO2 uptake increases with increasing PPFD following a typical curvilinear function and saturates for high PPFD (PPFD > 1000 µmol m-2 s-1), while during dry season, a very weak linear response of CO2 fluxes was observed. No clear dependency of the total ecosystem respiration on temperature was observed. At an annual scale (from November 1st 2005 to October 31st 2006), net carbon sequestered by the ecosystem was 18 +- 5 g C m-2. Finally, with respect to the water use the ecosystem appeared to be more efficient during morning and wet season than during afternoon and dry period. [less ▲]

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See detailIn the name of Benedetto Varchi: Agnolo Bronzino artist and poet
Geremicca, Antonio ULg

Scientific conference (2015, March 28)

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See detailLa collaboration entre différentes disciplines médicales : ou est le problème ? Etude Partnership in Medicine
Vanmeerbeek, Marc ULg; Govers, Patrick ULg; Schippers, Nathalie ULg et al

Conference (2015, March 27)

Objectifs Les maladies ou problèmes médicaux d’origine professionnelle, ou en lien avec le travail, impliquent à des degrés divers les médecins généralistes (MG), les médecins du travail (MT) et les ... [more ▼]

Objectifs Les maladies ou problèmes médicaux d’origine professionnelle, ou en lien avec le travail, impliquent à des degrés divers les médecins généralistes (MG), les médecins du travail (MT) et les médecins-conseils des mutuelles (MC). Le manque de relation fonctionnelle entre eux peut compliquer ou retarder le retour au travail du patient. L’étude cherchait des pistes d’amélioration de la collaboration. Méthode Deux méthodes de consensus ont été successivement utilisées parmi les trois professions : huit groupes nominaux (GN) ont réunis 74 médecins de terrain; deux rondes Delphi ont concerné 28 décideurs. Résultats Un seul médecin a été perdu de vue entre les 2 tours du Delphi. Les propositions issues des GN concernaient le transfert d’informations (surtout les MT et les MC), la collaboration (surtout les MG et les MT), les connaissances, et le cadre légal et réglementaire (surtout les MC). Cinq questions sur 14 n’ont pas fait consensus (≥75%) au 1er tour du Delphi, et 10 propositions sur 13 ont été rejetées au 2e tour. Les désaccords portaient sur la nature des données à transférer, les modalités de transfert d’information, la disponibilité des données de contact des médecins. Un processus d’évitement spécifique a été mis en évidence. Certains commentaires montraient un déni de la capacité des autres à comprendre son champ professionnel, et une difficulté à considérer leur spécificité propre. Conclusions L’étude montre que le patient n’est pas un objet partagé de la relation. Le modèle Resource Dependence Institutional Cooperation (De Rijk) permet de distinguer les entraves à la volonté de coopérer (dépendance perçue) des limitations dans la capacité à le faire (manque de ressources). Le modèle quadridimensionnel de la collaboration (D’Amour) identifie un déficit d’internalisation du côté relationnel (reconnaissance des autres), et un déficit de gouvernance et de formalisation du côté organisationnel, où des initiatives volontaristes des autorités seraient bienvenues. [less ▲]

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See detailLa dynastie belge et la science, 1909-1959
Pirot, Pascal ULg

Doctoral thesis (2015)

The project consists in investigating the role of the Belgian dynasty in scientific development since the beginning of the reign of king Albert I (1909), until the establishment of the National Council ... [more ▼]

The project consists in investigating the role of the Belgian dynasty in scientific development since the beginning of the reign of king Albert I (1909), until the establishment of the National Council for Science Policy (CNPS) in 1959, during king Baudouin's reign, following the publication of the work of the "National Commission on Science" which released its conclusions in the same year. The study deals with the action of the sovereign and the networks he formed with his entourage (the queen, the crown prince, the advisers of the court, some close relations of the king, the ministers in charge of scientific affairs) in the field of science, along various research themes; how these people saw the role of science in society; what influence they had in the development of science (institutions, initiatives, projects); what relationships existed between the dynasty and the scientific institutions; what the relationships between the dynasty and the Congo were in the realm of science. This perspective, which focuses on three Belgian sovereigns of the twentieth century, should make it possible to assess the development and progressive implementation of the "science policy". To date, no study has been specifically devoted to this topic. [less ▲]

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