Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailDictyonema interruptum, new for the Pyrenees
Etayo, Javier; Diederich, Paul; Sérusiaux, Emmanuël ULg

in Graphis Scripta (1995), 7

Detailed reference viewed: 10 (0 ULg)
Full Text
Peer Reviewed
See detailDid a Katian Large Igneous Province trigger the Late Ordovician glaciation ? A hypothesis tested with a carbon cycle model
Lefebvre, Vincent; Servais, Thomas; François, Louis ULg et al

in Palaeogeography, Palaeoclimatology, Palaeoecology (2010), 296

The Ordovician is known as a period with high temperatures and high sea levels and a cooling event at the end of the period, leading to the Hirnantian glaciation and the !rst of the ‘big !ve’ mass ... [more ▼]

The Ordovician is known as a period with high temperatures and high sea levels and a cooling event at the end of the period, leading to the Hirnantian glaciation and the !rst of the ‘big !ve’ mass extinctions of marine life. The cause of this cooling event remains unclear. Several authors correlate it with a drop in atmospheric pCO2 to a threshold permitting the ice accumulation on the Gondwana supercontinent. However, what are the reasons of the atmospheric pCO2 decrease? Here, we follow the hypothesis initiated by Barnes (2004) that an Ordovician superplume event occurred during the Middle to Late Ordovician. Such an event would not only have a large impact on the Ordovician biodiversi!cation (Barnes, 2004) but it would also be responsible for the climatic upheaval during the Late Ordovician by the emplacement of a low latitudinal continental basaltic province that had an impact on the atmospheric pCO2. There is no direct evidence of a superplume event or of basaltic traps and the present study is therefore a hypothetical modelling approach where we demonstrate with a numerical box model, including carbon, alkalinity and phosphorus cycles coupled with a 1D climate model (energy balance model-EBM) (François and Walker,1992), that such a scenario allows to explain both the mid-Ashgill (Katian) global warming event, known as the Boda Event (Fortey and Cocks, 2005), and the subsequent Late Ordovician (Hirnantian) glaciation. Because silicate weathering is enhanced upon warm and wet climate, we try to constrain the size and the latitudinal emplacement of the basaltic province leading to a suf!cient consumption of atmospheric pCO2 to the threshold proposed by Herrmann et al. (2004 a, b) to initiate a glaciation on Gondwana. [less ▲]

Detailed reference viewed: 66 (0 ULg)
See detailDid Pieter Brueghel the Younger See his Father's Paintings? Some methodoloical and critical reflections
Allart, Dominique ULg

in Van den Brink, Peter (Ed.) Brueghel Enterprises (2001)

Detailed reference viewed: 37 (2 ULg)
Full Text
Peer Reviewed
See detailDid Psychrophilic Enzymes Really Win the Challenge?
Zecchinon, Laurent ULg; Claverie, P.; Collins, T. et al

in Extremophiles : Life Under Extreme Conditions (2001), 5(5), 313-21

Organisms living in permanently cold environments, which actually represent the greatest proportion of our planet, display at low temperatures metabolic fluxes comparable to those exhibited by mesophilic ... [more ▼]

Organisms living in permanently cold environments, which actually represent the greatest proportion of our planet, display at low temperatures metabolic fluxes comparable to those exhibited by mesophilic organisms at moderate temperatures. They produce cold-evolved enzymes partially able to cope with the reduction in chemical reaction rates and the increased viscosity of the medium induced by low temperatures. In most cases, the adaptation is achieved through a reduction in the activation energy, leading to a high catalytic efficiency, which possibly originates from an increased flexibility of either a selected area of or the overall protein structure. This enhanced plasticity seems in return to be responsible for the weak thermal stability of cold enzymes. These particular properties render cold enzymes particularly useful in investigating the possible relationships existing between stability, flexibility, and specific activity and make them potentially unrivaled for numerous biotechnological tasks. In most cases, however, the adaptation appears to be far from being fully achieved. [less ▲]

Detailed reference viewed: 25 (0 ULg)
Full Text
See detailDid the savannah « flourished » 3000 years ago in the so-called Sangha River Interval of the Guineo-Congolian rainforest ? A retrospective study using stable isotopes and phytoliths
Bentaleb, Ilham; Freycon, Vincent; Gillet, Jean-François et al

Poster (2015, April)

We aim to improve our knowledge of the dynamic of the vegetation in Central Africa during the last 5 kyrs and to discuss the main hypothesis described in the literature - humans versus climatic impacts ... [more ▼]

We aim to improve our knowledge of the dynamic of the vegetation in Central Africa during the last 5 kyrs and to discuss the main hypothesis described in the literature - humans versus climatic impacts- both suggested as responsible of the Congo basin rainforest decline observed between 3 and 2.5 kyrs. We use the carbon isotopic composition of well-dated Central African soils to reconstruct the dynamic of the vegetation cover. We will discuss the carbon isotopic composition of the soil organic carbon methodology for reconstructing palaeovegetation in the light of Rayleigh distillation model. We showed that numerous sites exhibit a carbon isotopic ratios reflecting the Rayleigh distillation but few sites recorded real vegetation changes. Our study suggests that the vegetation of the Guineo-Congolian Region was disturbed between 3000 and 2000 BP (Before Present) without an extreme savannah expansion. We discussed the two hypotheses human versus climate impacts that may conduct to such new physiography of the vegetation. We suggest that the climate hypothesis is more likely than the human impact to explain the reduction of the Guineo-Congolian rainforest 3000 years ago. [less ▲]

Detailed reference viewed: 23 (2 ULg)
Full Text
Peer Reviewed
See detailA didactic presentation of Snijders’ lz* index of person fit with emphasis on response model selection and ability estimation
Magis, David ULg; Raîche, Gilles; Béland, Sébastien

in Journal of Educational & Behavioral Statistics (2012), 37

This paper focuses on two likelihood-based indices of person fit, the index lz (Drasgow, Levine & Williams, 1985) and the Snijders’ modified index lz* (Snijders, 2001). The first one is commonly used in ... [more ▼]

This paper focuses on two likelihood-based indices of person fit, the index lz (Drasgow, Levine & Williams, 1985) and the Snijders’ modified index lz* (Snijders, 2001). The first one is commonly used in practical assessment of person fit, although its asymptotic standard normal distribution is not valid when true abilities are replaced by sample ability estimates. The lz* index is a generalization of lz which corrects for this sampling variability. Surprisingly, it is not yet popular in the psychometric and educational assessment community. Moreover, there is some ambiguity about which type of item response model and ability estimation method can be used to compute the lz* index. The purpose of this paper is to present the index lz* in a simple and didactic approach. Starting from the relationship between lz and lz*, we develop the framework according to the type of logistic IRT model and the likelihood-based estimators of ability. The practical calculation of lz* is illustrated by analyzing a real data set about language skill assessment. [less ▲]

Detailed reference viewed: 55 (6 ULg)
Full Text
Peer Reviewed
See detailA DIDACTIC SURVEY OVER MAIN CHARACTERISTICS OF LAGRANGE'S THEOREM IN MATHEMATICS AND IN ECONOMICS
Xhonneux, Sebastian; Henry, Valérie ULg

in Proceedings of the 7th CERME Conference (2011)

Because of its many uses, the constrained optimization problem is presented in most calculus courses for mathematicians but also for economists. Looking at Lagrange's Theorem we are interested in studying ... [more ▼]

Because of its many uses, the constrained optimization problem is presented in most calculus courses for mathematicians but also for economists. Looking at Lagrange's Theorem we are interested in studying the teaching of this theorem in both branches of study, mathematics and economics. This paper faces a twofold objective: first, we show the methodology of our research project concerning the didactic transposition of Lagrange's Theorem in university mathematics courses. Secondly, we would like to compare two mathematics courses given at the universities of Namur and Louvain by means of the "Anthropological Theory of Didactics" of Yves Chevallard. [less ▲]

Detailed reference viewed: 29 (5 ULg)
Full Text
See detailUn didacticiel d'évaluation des connaissances sur le diabète chez l'enfant et l'adolescent
Ackermans, A.; Leclercq, Dieudonné ULg; Ernould, Céline ULg

in Leclercq, Dieudonné (Ed.) Handicaps et technologies (1986)

Un didacticiel a été conçu (et testé sur des enfants) pour évaluer les connaissances d'enfants diabétiques sur leur maladie. Le testing recourt à la mesure de la rapidité de réponse et au degré de ... [more ▼]

Un didacticiel a été conçu (et testé sur des enfants) pour évaluer les connaissances d'enfants diabétiques sur leur maladie. Le testing recourt à la mesure de la rapidité de réponse et au degré de certitude dans la réponse. La visualisation des résultats se fait sous la forme de briques d'une maison. Ces briques sont de couleurs différentes en fonction de la qualité (exact / inexacte) de la réponse, de sa rapidité (moins de 20 sec. vs plus de 20 sec) et de sa certitude. [less ▲]

Detailed reference viewed: 67 (3 ULg)
Peer Reviewed
See detailDidactics of mathematics as a scientific discipline
Schneider-Gilot, Marguerite ULg; Hauchart, Christiane

in Actes du 8eme congrès ICMI 1996 (1996)

Detailed reference viewed: 8 (0 ULg)
Peer Reviewed
See detailDidactics of Mathematics as a scientific discipline
Schneider-Gilot, Marguerite ULg; Hauchart, Christiane

Conference (1996)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailDidactique de l'énonciation, l'énonciation en didactique
Defays, Jean-Marc ULg

in Texte : Revue de Critique et de Théorie Littéraire (2001), (27-28), 209-218

Detailed reference viewed: 185 (3 ULg)
See detailDidactique de la géographie 1. Organiser les apprentissages
Merenne-Schoumaker, Bernadette ULg

Book published by Nathan (1994)

Deuxième édition refondue d'un manuel édité en 1986 par La FEGEPRO et qui sera réédité en 2005 par De Boeck (Bruxelles) sous le titre "Didactique de la Géographie. Organiser les apprentissages"

Detailed reference viewed: 32 (2 ULg)
Full Text
Peer Reviewed
See detailLa didactique de la géographie, Cent ans de géographie à l’Université de Liège, 1903-2003
Merenne-Schoumaker, Bernadette ULg

in Bulletin de la Société Géographique de Liège (2003), 43

100 years of training and research in didactics of geography at the University of Liege

Detailed reference viewed: 17 (0 ULg)
See detailDidactique de la Géographie. Organiser les apprentissages
Merenne-Schoumaker, Bernadette ULg

Book published by De Boeck - Nouvelle édition revue et mise à jour d'un ouvrage publié en 2006 par De Boeck (2012)

Fruit d'une expérience de plus de trente ans en matière de formation des enseignants et de multiples recherches et collaborations avec les milieux belges et étrangers de l'enseignement secondaire, l ... [more ▼]

Fruit d'une expérience de plus de trente ans en matière de formation des enseignants et de multiples recherches et collaborations avec les milieux belges et étrangers de l'enseignement secondaire, l'ouvrage propose aux enseignants et futurs enseignants un outil de formation organisé autour de quatre interrogations fondamentales : comment définir les objectifs des apprentissages, comment choisir et organiser les acquisitions de base, comment mettre en œuvre les démarches et les méthodes les plus adéquates, comment évaluer les acquis et les apprentissages ? Articulant géographie et pédagogie, théorie et pratique, le livre cherche aussi à travers des éléments de réflexion et des mises en œuvre concrètes à participer au renouveau de l'enseignement de la géographie. [less ▲]

Detailed reference viewed: 454 (5 ULg)
See detailDidactique de la Géographie. Organiser les apprentissages
Merenne-Schoumaker, Bernadette ULg

Book published by De Boeck - Nouvelle édition d'un ouvrage publié au préalable chez Nathan (2005)

Quelle géographie enseigner aujourd’hui et comment l’enseigner? Comment donner à tous les adolescents une réelle éducation géographique leur permettant de mieux se situer dans un monde de plus en plus ... [more ▼]

Quelle géographie enseigner aujourd’hui et comment l’enseigner? Comment donner à tous les adolescents une réelle éducation géographique leur permettant de mieux se situer dans un monde de plus en plus complexe et en évolution continuelle ? Comment organiser les apprentissages en tenant compte des besoins et des difficultés des élèves ? Comment mettre en place un enseignement qui prépare à apprendre, qui prépare à demain ? Telles sont quelques questions majeures posées à la didactique de la géographie, tant en Belgique que dans de nombreux pays étrangers, et auxquelles le livre tente d’apporter des réponses. [less ▲]

Detailed reference viewed: 63 (7 ULg)
See detailDidactique des langues anciennes et ordinateur
Denooz, Joseph ULg

Conference given outside the academic context (1987)

Detailed reference viewed: 33 (1 ULg)
See detailDidactique des langues et cultures
Defays, Jean-Marc ULg

Scientific conference (2013, May 28)

Detailed reference viewed: 29 (7 ULg)
See detailDidactique des langues et enseignement multilingue
Defays, Jean-Marc ULg

Conference (2010, October 01)

Detailed reference viewed: 17 (2 ULg)
See detailDidactique des langues sur objectifs spécifiques
Lucchini, Silvia ULg; Thyrion, Francine

Scientific conference (2005, April)

Detailed reference viewed: 25 (0 ULg)