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See detailQuid des acquis culturels de nos élèves au sortir du secondaire ? Étude transversale (2002-2009)
Jadoulle, Jean-Louis ULg; Stevens, Xavier ULg

Scientific conference (2015, January 14)

La recherche dont il est fait état porte sur la culture historique scolaire. Quels sont les "savoirs culturels" à caractère historique des élèves de 6e année de l'enseignement secondaire général ? Quel ... [more ▼]

La recherche dont il est fait état porte sur la culture historique scolaire. Quels sont les "savoirs culturels" à caractère historique des élèves de 6e année de l'enseignement secondaire général ? Quel est leur niveau de maîtrise de ces savoirs ? Dans quelle mesure cette maîtrise dépend-t-elle de l'indice socio-économique moyen de l'école et de la filière d'enseignement qu'ils fréquentent ? Ou du profil de l'école ? Comment cette maîtrise a-t-elle évolué durant la période 2002-2009, soit celle au cours de laquelle les nouveaux programmes, inspirés de l'approche par compétences, ont été implémantés ? [less ▲]

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See detail(Tissue PET) Vascular metabolic imaging and peripheral plasma biomakers in the evolution of chronic arotic dissections
SAKALIHASAN, Natzi ULg; NIENABER, Christoph; HUSTINX, Roland ULg et al

in European Heart Journal - Cardiovascular Imaging (2015)

Enhanced FDG uptake may be considered as a complementary imaging marker associated with secondary complications in type B dissections. During follow-up, aneurysmal progression is related to PET/CT and ... [more ▼]

Enhanced FDG uptake may be considered as a complementary imaging marker associated with secondary complications in type B dissections. During follow-up, aneurysmal progression is related to PET/CT and biomarkers of thrombus renewal and lysis. [less ▲]

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See detailPolitiques d'éducation et de formation : une approche par les capacités
Orianne, Jean-François ULg

Scientific conference (2015, January 13)

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See detailIntroduction to item response theory (IRT) and computerized adaptive testing (CAT) with the R software
Magis, David ULg

Scientific conference (2015, January 13)

Item response theory (IRT) has become an important field of research for psychology and educational assessment. Recently, with the increase of computational power, several IRT-related topics have emerged ... [more ▼]

Item response theory (IRT) has become an important field of research for psychology and educational assessment. Recently, with the increase of computational power, several IRT-related topics have emerged, among others, computerized adaptive testing (CAT). The main aim of CAT is to provide a framework for individualized assessment by means of optimal item selection and administration to the test takers. CAT has several assets to linear (non-adaptive) testing: individualized assessment, limited risk of cheating or fraud, shorter tests providing the same amount of information as longer linear tests, automatic scoring and reporting at the end of the test. Practical use of CAT, however, remains limited so far due to several factors (lack of available large item banks, content validity and security, lack of suitable software for practical CAT assessment, ethical issues in administering different tests to estimate the same ability, etc.). The purpose of this workshop is threefold: (a) to provide a general overview of IRT and CAT, (b) to introduce the R software in a user-oriented way, as well as several IRT tools (including the package catR for CAT simulations), (c) to perform practical training sessions with the participants. The workshop will be a mix of oral presentations, demonstrations related to the R software, and practical sessions where participants will be invited to train with R and catR. The R software is an open-source platform for statistical inference and testing, graphical display and data visualization. It also holds several add-on packages for specific IRT purposes (item calibration, ability estimation, multidimensional scaling, equating, differential item functioning etc.). The R community is worldwide and proposes free exchanges of shared R packages through the CRAN (comprehensive R archive network). In this workshop, the R package catR will be examined and used in the practical sessions. [less ▲]

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See detailLes institutions politiques belges après la sixième Réforme de l'État
Grandjean, Geoffrey ULg

Learning material (2015)

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See detailTable ronde : quand évoquer une maladie du motoneurone ?
WANG, François-Charles ULg; TINANT, France ULg

Scientific conference (2015, January 13)

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See detailCOPPER LEACHING FROM WASTE ELECTRIC CABLES BY BIOHYDROMETALLURGY
Lambert, Fanny ULg; Bastin, David ULg; Gaydardzhiev, Stoyan ULg et al

in Minerals Engineering (2015)

This study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption ... [more ▼]

This study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption. Operational parameters such as the nature of the oxidant (Fe3+, O2), the initial ferric iron concentration (0-10 g/L) and the temperature (21-50°C) were identified to have an important influence on the degree of copper solubilisation. At optimal process conditions, copper extraction above 90% was achieved in both leaching systems, with a leaching duration of 1 day. The bacterial leaching system slightly outperformed the chemical one but the positive effect of regeneration of Fe3+ was limited. It appears that the Fe2+ bio-oxidation is not sufficiently optimised. Best results in terms of copper solubilisation kinetics were obtained for the abiotic test at 50°C and for the biotic test at 35°C. Moreover, the study showed that in same operating conditions, a lower acid consumption was recorded for the biotic test than for the abiotic test. [less ▲]

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See detailGrandeur et misère du système politique belge
Grandjean, Geoffrey ULg

Conference given outside the academic context (2015)

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See detailFeedback loops: From cellular to network principles
Dethier, Julie ULg

Scientific conference (2015, January 12)

Biological rhythms play a major role in the functioning of the brain. However, the generation mechanisms and functions of these rhythms are still under debate and the question of which cellular details ... [more ▼]

Biological rhythms play a major role in the functioning of the brain. However, the generation mechanisms and functions of these rhythms are still under debate and the question of which cellular details must be retained at the network level is largely open. In this presentation, I will highlight that cellular properties have a major impact at the network level, especially in the study of modulation and robustness. I will focus on a particular cellular property, a positive feedback loop in a specific timescale, and illustrate its network level impact with two simple examples: the modulation and robustness of an half-center oscillator, a very simple central pattern generator composed of two reciprocal-inhibitory populations, and the control of transient beta-band oscillations in the basal ganglia, a group of subcortical nuclei that act as a cohesive functional unit, in relation to motor movements. [less ▲]

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See detailLa managérialisation de l’administration publique locale en Wallonie Comment l’autorité régionale tente de rationaliser l’action publique locale
Fallon, Catherine ULg

Scientific conference (2015, January 10)

A travers cette contribution, nous développerons une analyse critique des transformations actuelles du recours aux théories et méthodes du management public dans la gestion des politiques, à partir d’une ... [more ▼]

A travers cette contribution, nous développerons une analyse critique des transformations actuelles du recours aux théories et méthodes du management public dans la gestion des politiques, à partir d’une étude des développements récents de l’administration locale en Belgique (Wayenberg et al. 2015). Les autorités locales, politiques et administratives, se voient confrontées à une multiplication des injonctions à une approche stratégique de la gestion publique et aux démarches évaluatives en matière d’analyse politique. Ces outils de rationalisation sont couplés à une extension de la contractualisation de l’administration au niveau des cadres supérieurs. Ces démarches gestionnaires et stratégiques sont diffusées à travers les injonctions réglementaires, les programmes de financement des autorités régionales ainsi que les bureaux de consultants. Elles sont aussi couplées à une extension des processus participatifs, les citoyens étant plus souvent intégrés dans le développement et le pilotage de l’action publique, voire son évaluation. Il s’agit de mettre en évidence les effets réciproques des processus de rationalisation de l’action publique et de sa démocratisation. [less ▲]

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See detailProfession art-thérapeute?
Vandeninden, Elise ULg

Conference (2015, January 09)

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See detailManaging the carnivore comeback: assessing the adaptive capacity of the Eurasian lynx (Lynx lynx) to cohabit with humans in shared landscapes
Bouyer, Yaëlle ULg

Doctoral thesis (2015)

Conflicts between humans and large carnivores are one of the most visible examples of the challenges that arise when seeking to achieve coexistence between humans and wildlife. With their large spatial ... [more ▼]

Conflicts between humans and large carnivores are one of the most visible examples of the challenges that arise when seeking to achieve coexistence between humans and wildlife. With their large spatial requirements and predatory behavior, large carnivores are among the most difficult species to preserve in our modern day landscapes. Although large carnivores are usually considered as the epitomes of wilderness, because of human population growth and habitat fragmentation they are inexorably and increasingly faced with the need to live in human-modified landscapes. As a direct consequence, conflicts over depredation on livestock, competition for game species and sometimes over human injury or death will only increase if clear management measures are not taken. This is particularly true in Europe, where, after many decades of absence, large carnivores are recolonizing areas where millions of people are present and where landscapes have been drastically modified. Two approaches to integrating wildlife into a human-dominated world have been proposed at an international scale. The first solution is called land sparing, in which wildlife lives exclusively in protected or wilderness areas where contact between animals and humans will be reduced to the minimum. The second solution, called land sharing, proposes to integrate human activities and wildlife in the same landscapes in non-protected interface zones in what is often called a coexistence approach. In a context of scarce true wilderness areas and a continuum of human-modified habitats, land sharing (i.e. the coexistence approach) is seen as the only possible approach valid for Europe. While a coexistence approach can be readily implemented with smaller species, it can represent a major challenge for species with large space requirements and with predatory behavior. To help manage these species in a long-term conservation vision and to predict where potential conflicts could arise between humans and carnivores, information on large carnivores and their habitat use in anthropogenic landscapes is a pre-requisite. With the return of Eurasian lynx Lynx lynx in Western Europe, the most densely populated areas of the continent_ information on the species tolerance to human land use will help predict where it is likely to occur in anthropogenic landscapes. Data collected in Scandinavia over 15 years were used to assess the use of landscape by lynx. In this study, we explored the effect of anthropogenic and environmental factors on Eurasian lynx habitat use in Scandinavia. The work was developed along two main axes. The first axis aims to explore large scale potential patterns of lynx distribution through transferability of results obtained from habitat modelling to geographically different areas. Transferability of results was tested in two steps. Firstly, transferability success (i.e. predictive ability of the map) was tested at a regional scale using data on roe-deer, the main prey of lynx, to create a map of relative distribution and abundance of prey in southeastern Norway (Chapter 1). Secondly, transferability success was assessed at a larger extent and using data obtained from different sampling method (Chapter 2). A habitat suitability map for Eurasian lynx was produced to be used in management planning in geographically differentiated lynx management zones in Scandinavia. The results indicated that transferability of results from one region to an ecologically different region must be taken with caution. Nevertheless, the habitat suitability maps we constructed on the basis of extrapolation are a valuable asset to help management of the Scandinavian lynx population. The second axis deals with lynx habitat use in relation to anthropogenic and environmental predictors. Lynx tolerance to human presence was first explored by looking at the orientation of home range in the landscape, taking into account proxies of human presence (Chapter 3). Values of these proxies were compared both inside home ranges and within a buffer surrounding the home ranges for several lynx inhabiting an anthropogenic gradient going from near-wilderness to urban periphery. Results showed a high diversity in the extent to which individual lynx are exposed to human influence, indicating that lynx are highly adaptable in terms of living space. Lynx seemed to be able to orientate their home range in order to avoid highest human impacts and select for areas of medium human impacts. Building on these results, finer scale information on lynx habitat use in an anthropogenic landscape were obtained taking into consideration different types of behavior (day-beds, moving and killing) displayed by adult lynx, as well as the effect of cumulative anthropogenic pressures on habitat selection (Chapter 4). Our results showed that lynx select for areas with medium levels of human modification, avoiding both the areas with highest and least modification. Females in general appear to be less tolerant to human modification than males, especially for day-beds. Our study shows that Eurasian lynx can be considered as a species that is adaptable to human- induced changes in landscape even if its motivation to tolerate human presence is clearly linked to the presence and density level of its main prey, the roe deer. Our work shows that, contrary to much of the public and many conservation professionals’ opinions, land sharing with large carnivores in Europe may be possible – even in the immediate proximity to urban centers. However, it is important to bear in mind that these results were obtained from countries with a relatively low human population density; even though some individuals observed lived in the periphery of large cities, the level of habitat fragmentation is less severe than in most of Western Europe. In order to properly assess the capacity of Eurasian lynx to live in highly populated areas, such as the Benelux, more detailed information on lynx distribution from continental European will be needed. However, our results underline the value of combining both correlational and mechanistic studies, and the need for caution in extrapolating data too far from its original context. As large carnivore recovery continues to progress in Europe we may not yet have seen the limits of these species' abilities to adapt. [less ▲]

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See detailImproving the performance of μ-ORC systems
Declaye, Sébastien ULg

Doctoral thesis (2015)

This thesis contributes to the knowledge and the characterization of micro Organic Rankine Cycles (ORC). It is based on experimental data and simulation models. An oil-free scroll expander is tested in a ... [more ▼]

This thesis contributes to the knowledge and the characterization of micro Organic Rankine Cycles (ORC). It is based on experimental data and simulation models. An oil-free scroll expander is tested in a wide range of operating conditions in order to better characterize its performance. Particular attention is paid to the tightness of the machine which is obtained using a magnetic coupling. The measured isentropic efficiency reaches 75% which is higher than typical values reported in the literature. From the experimental results, a performance map of the expander is generated. This performance map can be used to provide fast and accurate calculation of the volumetric and isentropic performance of the expander in a wide range of operating conditions. Five displacement pumps adapted to μ-ORC systems are also tested. These pumps are diaphragm, piston, plunger and gear types. The measured values include the overall efficiency, the volumetric efficiency and the NPSH. A deep analysis of the performance is performed to quantify the losses of each pump, of their electric motor and of their frequency drive. This analysis shows that the weakness of the overall effectiveness (max. 46%) of the pumps tested is mainly due to the low efficiency of the electric motor. A semi-empirical model of the diaphragm pump is proposed and validated based on manufacturer data. This model can predict the mechanical power of the pump and the flow delivered with a good accuracy. The simulation models developed for the expander and the pump are used to simulate a configuration including the pump, the generator and the expander on a single shaft. This configuration aims to avoid the use of a motor and a frequency drive whose performance is poor in the range of power consumed by the pump of a μ-ORC system. The results show a significant increase in the net power produced using the integrated configuration Finally, performance of a prototype of μ-ORC suitable for recovering heat from a two-stage screw compressor are measured and analyzed. The prototype allows generating maximum 3.9% of the electrical power consumed by the compressor. Several optimization options of the prototype are evaluated numerically, showing that the power generation could be increased up to 5.4% of the compressor consumption. These options include using the integrated configuration and optimizing the intercooler boiler design. [less ▲]

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See detailAnalyse de l'actualité fédérale et régionale par le prisme des finances publiques
Piron, Damien ULg

Conference given outside the academic context (2015)

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See detailLes médiateurs scolaires : une ressource pour la gestion des désordres scolaires
Dethier, Baptiste ULg

Conference (2015, January 09)

Dans de nombreux pays, principalement anglo-saxons, la médiation par les pairs s’est développée dans les écoles. Cependant, la spécificité de la Belgique francophone réside dans le développement, par des ... [more ▼]

Dans de nombreux pays, principalement anglo-saxons, la médiation par les pairs s’est développée dans les écoles. Cependant, la spécificité de la Belgique francophone réside dans le développement, par des fonctionnaires publics spécialisés, de dispositifs de médiation scolaire (Kuty et al., 2012). Censés prévenir la violence et le décrochage scolaires et agir sur le climat de l’école, ces dispositifs ne sont pas uniquement destinés à résoudre les problèmes posés par les élèves perturbateurs (ou plutôt de ces élèves en tant que problèmes eux-mêmes) mais aussi à stimuler la participation, l’implication et la responsabilisation des adultes, principalement les enseignants. De ce fait, ils interrogent les formes scolaires traditionnelles, voire bousculent les équilibres historiques du système (Verhoeven, 1997), en ouvrant davantage que des espaces de « traitement » des élèves dits « à problèmes ». Sur base de dix entretiens semi-directifs, cinq focus groups et trois périodes d’observation non participante auprès de médiateurs scolaires belges francophones, cette communication a pour objectif de décrire le cœur du travail de ces derniers pour mieux en saisir les caractéristiques et les enjeux. En effet, à partir d’un cadre légal restreint et flou initié dans les années 1990, les médiateurs ont développé des pratiques et des dispositifs s’inscrivant dans une logique de médiation, organisés sur le principe de l’intervention d’un tiers dit neutre et indépendant visant à aider au rétablissement d’une relation entre deux parties. Ces dispositifs cherchent à rompre avec les logiques historiques de stigmatisation des élèves perturbateurs, que nous interrogerons. [less ▲]

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See detailErosion and sedimentation issues in a hydropower project: assessing impacts and opportunities
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Schüttrumpf, Holger (Ed.) Offene Gewässer: Strahlwirkung, Fischaufstieg, Fischabstieg, Sedimente, Schadstoffe (2015, January 09)

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See detailSymmetry breaking patterns in 3HDM
Ivanov, Igor ULg; Nishi, Celso

in Journal of High Energy Physics [=JHEP] (2015), 15

An attractive feature of New Physics models with multiple Higgs fields is that they are equipped with discrete symmetry groups in the Higgs and flavour sectors. These symmetry groups are often broken at ... [more ▼]

An attractive feature of New Physics models with multiple Higgs fields is that they are equipped with discrete symmetry groups in the Higgs and flavour sectors. These symmetry groups are often broken at the global minimum of the Higgs potential, either completely or to a proper subgroup, with certain phenomenological consequences. Here, we systematically explore these symmetry breaking patterns in the scalar sector of the three-Higgs-doublet model (3HDM). We use the full list of discrete symmetry groups allowed in 3HDM, and for each group we find all possible ways it can break by the Higgs vacuum expectation value alignment. We also discuss the interplay between these symmetry groups and various forms of CP-violation in the scalar sector of 3HDM. Not only do our results solve the problem for 3HDM, but they also hint at several general features in multi-scalar sectors. [less ▲]

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