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See detailLink between learning profile and school achievement in primary school; a transversal study
Frenkel, Stéphanie ULg; Nobile, Debora ULg

Conference (2014, July)

School achievement plays an essential role in terms of professional and social adaptation. However, all the students do not always perform as the system requires them to. In Belgium, at the end of ... [more ▼]

School achievement plays an essential role in terms of professional and social adaptation. However, all the students do not always perform as the system requires them to. In Belgium, at the end of compulsory education, one student out of two lags behind in their school education (Indicators from the Fédération Wallonie-Bruxelles [Walloon-Brussels Federation], 2012). In this context, we do not consider that there are “bad” learners. Instead, there are those students whose learning profile is more or less in line with the context’s requirements and those whose profile is not. In many works, the student’s learning profile is operationalised by measures on 3 levels: cognitive, metacognitive and psycho-affective. These psychological variables, which are major components of self-regulated learning, play a central role in the explanation of school performance (for more details, see Frenkel, in press; Frenkel & Deforge, in press). This profile is not fixed once and for all. It evolves over time and it represents the result of the interaction between these three variables with other factors, notably bio-medical, socio-demographical ones, factors related to family environment (Pourtois, Desmet & Lahaye, 2004; Trudel, Puentes-Neuman & Ntebutse, 2002) and the too often forgotten factors linked to class management and social interactions between students and teachers (see Wang, Haertel & Walberg, 1994). Determining the students’ learning profile enables us to identify their strengths and work on their weaknesses. Therefore, it is essential that psycho-educational teams have validated tools at their disposal in order to carry out this task. Our aim is to propose new tools which will complement the already-existing ones. In this presentation we propose to introduce and discuss our methodology and the results obtained. The starting target population was made up of 198 primary school students divided equitably into three levels (second year of primary school, fourth year of primary school and sixth year of primary school). A problem-solving task based on the DELF (Büchel & Büchel, 1995) was created. It was completed by two questionnaires to fill in before and after the task. The learning profile defined on this basis was analysed according to several variables (age, gender, socio-professional category, school results). Group testing is still in progress. We will also illustrate our presentation with the first results of individual testing which will begin in May 2014. References - Büchel, F.P. & Büchel, P. (1995). Découvrez vos capacités, rEalisez vos possibilités, pLanifiez votre démarche, soyez créatiFs. Le programme DELF. Russin, Switzerland: Centre d’éducation cognitive - Frenkel, S. (in press). Metacognitive components in learning to learn approaches. International Journal of Psychology: A Biopsychosocial Approach - Frenkel, S., & Deforge, H. (in press). Métacognition et réussite scolaire: Perspectives théoriques. In C. Giraudeau & G. Chasseigne (Eds.), Psychologie, Education et Vie scolaire. Tours, France: Editions Publibook Université - Pourtois, J.-P., Desmet, H., & Lahaye, W. (2004). Connaissances et pratiques en éducation familiale et parentale. Enfances, Familles, Générations, 1, 22-35 - Trudel, M., Puentes-Neuman, G., & Ntebutse J.G. (2002). Les conceptions contemporaines de l’enfant à risque et la valeur heuristique du construit de résilience en éducation. Revue Canadienne de l’Education, 27 (2 & 3), 153-173 - Wang, M.C., Haertel, G.D., & Walberg, H.J. (1994). What helps students learn? Educational Leadership, 51 (4), 74-79 [less ▲]

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See detailSoil compaction resulting from different soil tillage systems
Destain, Marie-France ULg; Roisin, Christian; Mercatoris, Benoît ULg

in ASABE - CSBE/ASABE Joint Meeting Presentation (2014, July)

The effects of long-term use (8 years) of two different tillage systems were assessed on a Luvisol, under temperate climate (Belgium). The tillage treatments were (i) conventional tillage (CT) with ... [more ▼]

The effects of long-term use (8 years) of two different tillage systems were assessed on a Luvisol, under temperate climate (Belgium). The tillage treatments were (i) conventional tillage (CT) with moldboard ploughing to 27 cm depth and (ii) reduced tillage (RT) with a spring tine cultivator to 10 cm depth. The measurements included bulk density (BD) and precompression stress (Pc) chosen as indicators of mechanical strength, and the pore size distribution (PSD) measured by mercury intrusion porosimetry (MIP). The tillage systems, the depth and their interaction had a significant effect on BD, Pc and PSD. In CT, in the topsoil, the soil strength was low and the total porosity n was about 50 %. In the subsoil, n decreased to 43 %. The PSD of CT was uni-modal in topsoil and subsoil in the MIP measurement range. The mean value of the mode rmax diminished from the topsoil toward the subsoil (from 2.5 microns to 1.9 microns). In RT, in the topsoil, the soil strength was higher than CT. BD did not vary much according to the depth. The total porosity n of RT was comprised between 40-45 % in the soil profile. The PSD was uni-modal and rmax increased from topsoil (around 2 microns) to subsoil (> 3 microns). This suggested the agglomeration of fine particles under the long-term action of mechanical loads, climatic agents, biological organisms or clay minerals acting as cementing agents. These phenomena could be at the origin of the increase of Pc with the depth without significant modification of BD. Such high values of Pc could be responsible of negative effects on root-growth leading to a more superficial root lateral development. [less ▲]

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See detailStability and bifurcation analysis of a Van der Pol–Duffing oscillator with a nonlinear tuned vibration absorber
Habib, Giuseppe ULg; Kerschen, Gaëtan ULg

Conference (2014, July)

The Van der Pol (VdP) oscillator is a paradigmatic model for description of self-excited oscillations, which are of practical interest in many engineering applications. In this paper the dynamics of a VdP ... [more ▼]

The Van der Pol (VdP) oscillator is a paradigmatic model for description of self-excited oscillations, which are of practical interest in many engineering applications. In this paper the dynamics of a VdP-Duffing (VdPD) oscillator with an attached nonlinear tuned vibration absorber (NLTVA) is considered; the NLTVA has both linear and nonlinear restoring force terms. In the first part of this work, the stability of the trivial solution of the system is investigated, following results of previous works. The analysis allows to define an optimal tuning rule for the linear parameters of the absorber, which substantially enlarges the domain of safe operation of the primary system. In this case, the system loses stability through a double Hopf bifurcation. In the second part of this work, the bifurcations occurring at the loss of stability are analytically investigated, using the technique of the center manifold reduction and transformation to normal form. The obtained results show the effects of the nonlinear parameter of the absorber, which, in turn, allows to define its optimal value in order to avoid subcriticality and reduce the amplitude of self-excited oscillations. [less ▲]

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See detailNegation, grammaticalization and subjectification: the development of polar, modal and mirative no way-constructions
Davidse, Kristin; Brems, Lieselotte ULg; Lesage, Jakob et al

Conference (2014, July)

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See detailAdvanced Aeroservoelastic Modeling for Horizontal axis Wind Turbines
Prasad, Chandra Shekhar ULg; Chen, Qiong-zhong; Dimitriadis, Grigorios ULg et al

in Cunha, A.; Caetano, E.; Riberio, P. (Eds.) et al Proceedings of the 9th International Conference on Structural Dynamics, EURODYN 2014 (2014, July)

This paper describes the development of a complete methodology for the unsteady aeroelastic and aeroservoelastic modeling of horizontal axis wind turbines at the design stage. The methodology is based on ... [more ▼]

This paper describes the development of a complete methodology for the unsteady aeroelastic and aeroservoelastic modeling of horizontal axis wind turbines at the design stage. The methodology is based on the implementation of unsteady aerodynamic modeling, advanced control strategies and nonlinear finite element calculations in the S4WT wind turbine design package. The aerodynamic modeling is carried out by means of the unsteady Vortex Lattice Method, including a free wake model. The complete model also includes a description of a doubly fed induction generator and its control system for variable speed operation and enhanced power output. The S4WT software features a non-linear finite element solver with multi-body dynamics capability. The complete methodology is used to perform complete aeroservoelastic simulations of a 2MW wind turbine prototype model. The interaction between the three components of the approach is carefully analyzed and presented here. [less ▲]

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See detailBiological indicators of soil quality over landscape spatial scales: a case study in Southern Belgium
Krüger, Inken ULg; Chartin, Caroline; Van Wesemael, Bas et al

Poster (2014, July)

Biological indicators are organisms or biological processes whose values give quantitative information on the capacity of a soil to function. Their fast dynamic allows to detect changes on short ... [more ▼]

Biological indicators are organisms or biological processes whose values give quantitative information on the capacity of a soil to function. Their fast dynamic allows to detect changes on short timescales. Five biological indicators (basal respiration, nitrogen mineralisation, microbial carbon and nitrogen, earthworm abundance and biomass, functional microbial diversity) as well as two ecophysiological indices (microbial quotient and metabolic quotient) were tested for their power to characterize the biological soil quality on a landscape level at 60 sites in two South-Belgian landscape units were investigated. All biological indicators differed significantly between the two landscape units showing the biological indicators to be discriminatory on a landscape level. Within each landscape unit, no relationships between biological indicators were found, underlining the need to measure multiple biological indicators. The results represent the first data for a South-Belgian monitoring network of biological soil quality. [less ▲]

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See detailOptimization Of A Heat Pump For Satellite Cooling
Bell, Ian ULg; Lemort, Vincent

in 15 th International Refrigeration and Air Conditioning Conference at Purdue (2014, July)

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See detailMars dayglow review
Stiepen, Arnaud ULg

Conference (2014, July)

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See detailEnhancement of ray tracing method for radiative heat transfer with new isocell quasi-monte carlo technique and application to EUI space instrument
Jacques, Lionel ULg; Masset, Luc ULg; Kerschen, Gaëtan ULg

in Proceedings of the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, HEFAT2014 (2014, July)

Monte Carlo ray tracing method for thermal analysis. The rationale for this research is the speed-up of radiative heat transfer computation with the Finite Element Method, widely used in mechanical ... [more ▼]

Monte Carlo ray tracing method for thermal analysis. The rationale for this research is the speed-up of radiative heat transfer computation with the Finite Element Method, widely used in mechanical engineering especially for space structure design but not yet often for thermal analysis of these structures. Based on Nusselt’s analogy, the ray direction sampling is done by sampling the unit disc to derive the ray directions. Stratified sampling is applied to the unit disc that is divided into cells or strata into which random points are generated. The isocell method relies on cells that have the particularity of presenting almost the same area and shape. This enhances the uniformity of the generated quasi-random sequence of ray directions and leads to faster convergence. The isocell method is associated with different surface sampling to derive REFs. The method is benchmarked against ESARAD, the standard ray tracing engine of the thermal analysis software used in the European aerospace industry. Various geometries are used. In particular, one entrance baffle of the Extreme Ultraviolet Imager (EUI) instrument developed at the Centre Spatial de Liège in Belgium is presented. The EUI instrument of the Solar Orbiter European Space Agency mission and will be launched in a 0.28 perihelion orbit around the Sun in 2018. [less ▲]

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See detailAt the Crossroads of Greek and Roman Medicine: the Contribution of Latin Papyri. I. Medical Texts
Marganne, Marie-Hélène ULg

in Maire, Brigitte (Ed.) 'Greek' and 'Roman' in Latin Medical Texts. Studies in Cultural Change and Exchange in Ancient Medicine (2014, July)

Far fewer Latin medical papyri, whether paraliterary, documentary or magical, have survived compared to Greek medical papyri, but they nonetheless provide interesting information about medical practices ... [more ▼]

Far fewer Latin medical papyri, whether paraliterary, documentary or magical, have survived compared to Greek medical papyri, but they nonetheless provide interesting information about medical practices in the Graeco-Roman world, the relationship between Greek and Latin medical languages, and the choices made to use one rather than the other, a subject that has never been exhaustively studied. As part of the update undertaken by CEDOPAL since 2008 of the Corpus Papyrorum Latinarum, published fifty years ago by the late Robert Cavenaile, we have inventoried Latin papyri containing medical references, classifying them by type or nature of content, provenance, form, layout and writing. We finally analyse their content and what it reveals about the reception of Greek medicine by Latin or Latin-speeking writers. [less ▲]

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See detailSentence repetition task as a powerful diagnostic tool in French children with SLI
Leclercq, Anne-Lise ULg

Poster (2014, July)

Sentence repetition is considered as a psycholinguistic marker of specific language impairment (SLI) (i.e., Redmond et al., 2011). However, little is known about specificity and sensitivity for most ... [more ▼]

Sentence repetition is considered as a psycholinguistic marker of specific language impairment (SLI) (i.e., Redmond et al., 2011). However, little is known about specificity and sensitivity for most language tests, especially in French (Thordardottir et al., 2011). This study aims at assessing the specificity and sensitivity of a sentence repetition task frequently used in clinical evaluations (Chevrie-Muller et al., 2010). This task could be especially interesting because clinicians can compute separate linguistic scores depending on the answers produced by the children, enabling them to get a glimpse of the areas of language difficulties in these children. Fourty-four school-age children with SLI, and 34 age-and-IQ-matched controls participated in this study. Children with SLI were diagnosed by certified speech-language pathologists and attained specific language classes in special needs schools from at least one year. Moreover, they scored more than -1.25 SD below expected normative performance in at least 2 language areas on other standardised tests used in previous studies including French children with SLI. Results show that both sensitivity and specificity of general scores were high (over 80%) at three cut-off points widely used in clinical practice: -1SD, -1.25 SD, -2 SD. Moreover, an exploratory factorial analysis indicates that two distinct factors can be dissociated in children productions: a morphosyntactic factor and a lexico-semantic factor, together explaining 96.48% of the variance in production scores. These results reveal that the sentence repetition task is a powerful diagnostic tool in French children with SLI. [less ▲]

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See detailVibration analysis by speckle interferometry with CO2 lasers and microbolometers arrays
Vandenrijt, Jean-François ULg; Thizy, Cédric ULg; Georges, Marc ULg

in OSA Technical Digest (online) (2014, July)

Speckle interferometry in the time-average mode in long wave infrared is shown for observing the mode shapes of vibrating objects. The long wavelength allows observing larger vibration displacements than ... [more ▼]

Speckle interferometry in the time-average mode in long wave infrared is shown for observing the mode shapes of vibrating objects. The long wavelength allows observing larger vibration displacements than what is achieved with visible wavelengths. [less ▲]

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See detailUpdate on investigation in IPF - Clinical presentation and epidemiology in domestic animals
Clercx, Cécile ULg

in Proceedings of the Fibrosis Across Species Consortium - Louisville - EU - 27th – 29th April 2014 (2014, July)

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See detailExcavation damaged zone modelling including hydraulic permeability evolution in unsaturated argilaceous rock
Pardoen, Benoît ULg; Levasseur, Séverine ULg; Collin, Frédéric ULg

in 6th International Conference on Unsaturated Soils (2014, July)

The drilling of galleries induces damage propagation in the surrounding medium and creates the Excavation Damaged Zone (EDZ) in which the material properties are modified. The prediction of the fracture ... [more ▼]

The drilling of galleries induces damage propagation in the surrounding medium and creates the Excavation Damaged Zone (EDZ) in which the material properties are modified. The prediction of the fracture structure and flow properties evolution within this zone are major issues especially in the context of underground nuclear waste storage. Since experimental results indicate that shear strain localisation appears prior to fractures, we model the EDZ with strain localisation in shear band mode using the coupled local second gradient model. The evolution of the intrinsic hydraulic permeability inside the fractures is taken into consideration as well as the influence of gallery ventilation on the rock desaturation. The numerical results provide information about the damaged zone extension, structure and behaviour with good correspondence to in situ measurements and observations. [less ▲]

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See detailOrder reduction in time integration caused by velocity projection
Arnold, Martin; Cardona, Alberto; Bruls, Olivier ULg

in Proceedings of the 3rd Joint International Conference on Multibody System Dynamics and the 7th Asian Conference on Multibody Dynamics (2014, July)

Holonomic constraints restrict the configuration of a multibody system to a subset of the configuration space. They imply so called hidden constraints at the level of velocity coordinates that may ... [more ▼]

Holonomic constraints restrict the configuration of a multibody system to a subset of the configuration space. They imply so called hidden constraints at the level of velocity coordinates that may formally be obtained from time derivatives of the original holonomic constraints. A numerical solution that satisfies hidden constraints as well as the original constraint equations may be obtained considering both types of constraints simultaneously in each time step (stabilized index-2 formulation) or using projection techniques. Both approaches are well established in the time integration of differential-algebraic equations. Recently, we have introduced a generalized- alpha Lie group time integration method for the stabilized index-2 formulation that achieves second order convergence for all solution components. In the present paper, we show that a separate velocity projection would be less favourable since it may result in an order reduction and in large transient errors after each projection step. This undesired numerical behaviour is analysed by a one-step error recursion that considers the coupled error propagation in differential and algebraic solution components. This one-step error recursion has been used before to prove second order convergence for the application of generalized-alpha methods to constrained systems. As a technical detail, we discuss the extension of these results from symmetric, positive definite mass matrices to the rank deficient case. [less ▲]

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See detailMetacognition and school learning: Individual use of the DELV program with teenagers
Frenkel, Stéphanie ULg; Nobile, Debora ULg

Conference (2014, July)

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010 ... [more ▼]

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010, 2011). It includes 8 types of decontextualized exercises which notably allow to develop the learner’s metacognitive knowledge and skills (for more details, see Büchel, 2013b). They also make it possible to work on cognitive and psycho-affective aspects. Transfer can thus be better developed. This tool has been used since its first version (Büchel & Büchel, 1995) both at the Atelier d’Apprentissage of the University of Genève (Unige, Switzerland) and at that of the University of Liège (ULg, Belgium) since their creation (respectively in 1996 and in 2009), (for more details, see Büchel, 2013a; Frenkel, in press (b)). Our main purpose is to present how we can use this tool individually in order to enable the student to activate his/her “sleeping potential” (for more details, see Frenkel, in press (a)). By focusing on adolescence, we will present (a) our theoretical background (conception of learning and intellectual functioning, criteria and levels of mediation), (b) the variables worked on, and (c) the results obtained. Note: Part of the Psychological and Speech therapy consultation Centre (CPLU, ULg), Belgium’s Atelier d’Apprentissage [Learning Workshop] intended for children and teenagers with temporary school learning difficulties. See www.cplu.ulg.ac.be References - Büchel, F.P. (2013a). L’intervention psychopédagogique auprès des enfants ayant des difficultés d’apprentissage. Un modèle métacognitif et d’autorégulation. In J.-L. Berger & F.P. Büchel (Eds.), L’autorégulation de l’apprentissage: Perspectives théoriques et applications (pp. 71- 105). Nice, France: Les Editions Ovadia. - Büchel, F.P. (2013b). Le programme DELV – Comprendre son propre apprentissage. Evaluation scientifique auprès d’enfants et d’adolescents sans ou avec difficultés d’apprentissage. In J.-L. Berger & F.P. Büchel (Eds.), L’autorégulation de l’apprentissage: Perspectives théoriques et applications (pp. 293-336). Nice, France: Les Editions Ovadia. - Büchel, F.P. & Büchel, P. (1995). Découvrez vos capacités, rEalisez vos possibilités, pLanifiez votre démarche, soyez créatiFs. Le programme DELF. Russin, Switzerland: Centre d’éducation cognitive. - Büchel, F.P., & Büchel, P. (1997). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens und Denkens für Jugendliche und Erwachsene. Aarau, Switzerland: Sauerländer. - Büchel, F.P. & Büchel, P. (2010). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens für Jugendliche und Erwachsene (4. überarbeitete Auflage). Berne, Switzerland: h.e.p. Verlag. - Büchel, F.P. & Büchel, P. (2011). DELV. Comprendre son propre apprentissage. Tegna, Suisse: Centre d’éducation cognitive. - Frenkel, S. (in press (a)). Metacognitive components in learning to learn approaches. International Journal of Psychology: A Biopsychosocial Approach. - Frenkel, S. (in press (b)). Métacognition et réussite scolaire : Applications. In C. Giraudeau & G. Chasseigne (Eds.), Psychologie, Education et Vie scolaire. Tours, France: Editions Publibook Université. - Frenkel, S., & Deforge, H. (in press). Métacognition et réussite scolaire: Perspectives théoriques. In C. Giraudeau & G. Chasseigne (Eds.), Psychologie, Education et Vie scolaire. Tours, France: Editions Publibook Université. [less ▲]

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See detailMetacognition and school learning: Use of the DELV program in primary school
Nobile, Debora ULg; Frenkel, Stéphanie ULg

Poster (2014, July)

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010 ... [more ▼]

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010, 2011). It includes 8 types of decontextualized exercises which notably allow to develop the learner’s metacognitive knowledge and skills (for more details, see Büchel, 2013). They also make it possible to work on cognitive and psycho-affective aspects. Transfer can thus be better developed. This tool is really useful (for more details, see Berger & Büchel, 2013) and, in our opinion, still not sufficiently known. Our main purpose is to present (a) its objectives, (b) the variables worked on (cognitive, metacognitive and psycho-affective), (c) possible uses in a school context within classes (e.g., the “sandwich method”) and (d) the outcome we can expect. References - Berger, J.-L., & Büchel, F.P. (2013), L’autorégulation de l’apprentissage: Perspectives théoriques et applications. Nice, France: Les Editions Ovadia. - - Büchel, F.P. (2013). Le programme DELV – Comprendre son propre apprentissage. Evaluation scientifique auprès d’enfants et d’adolescents sans ou avec difficultés d’apprentissage. In J.-L. Berger & F.P. Büchel (Eds.), L’autorégulation de l’apprentissage: Perspectives théoriques et applications (pp. 293-336). Nice, France: Les Editions Ovadia. - Büchel, F.P. & Büchel, P. (1995). Découvrez vos capacités, rEalisez vos possibilités, pLanifiez votre démarche, soyez créatiFs. Le programme DELF. Russin, Switzerland: Centre d’éducation cognitive. - Büchel, F.P., & Büchel, P. (1997). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens und Denkens für Jugendliche und Erwachsene. Aarau, Switzerland: Sauerländer. - Büchel, F.P. & Büchel, P. (2009). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens für Jugendliche und Erwachsene (3. vollständig überarbeitete Auflage). Berne, Switzerland: h.e.p. Verlag. - Büchel, F.P. & Büchel, P. (2010). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens für Jugendliche und Erwachsene (4. überarbeitete Auflage). Berne, Switzerland: h.e.p. Verlag. - Büchel, F.P. & Büchel, P. (2011). DELV. Comprendre son propre apprentissage. Tegna, Switzerland: Centre d’éducation cognitive. [less ▲]

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See detailLa flexicurité : vers une carrière transitionnelle?
Beuker, Laura ULg

Conference (2014, July)

Ces dernières années, les institutions Européennes ont joué un rôle clé dans la régulation et l’orientation des politiques publiques pour l’emploi des États-membres (Amparo-Serrano et Martin-Martin, 2012 ... [more ▼]

Ces dernières années, les institutions Européennes ont joué un rôle clé dans la régulation et l’orientation des politiques publiques pour l’emploi des États-membres (Amparo-Serrano et Martin-Martin, 2012). Dans ce cadre, la flexicurité s’est imposée comme une référence des politiques en matière de droit du travail, d’emploi, de sécurité sociale et de formation professionnelle (Conter et Orianne, 2011). En Belgique, cette exigence d’allier flexibilité et sécurité sur le marché du travail a constitué le cœur de nombreux discours et programmes politiques, pour finir par s’estomper progressivement, à la suite de crises financières et économiques l’ayant fortement éprouvé. Ce « concept » a-t-il pour autant effectivement disparu ? À partir d’une étude qualitative basée sur des entretiens semi-directifs menés auprès d’acteurs institutionnels – experts et analystes du marché du travail – nous nous sommes rendu compte que si la sémantique n’est plus, les principes de flexicurité sont, quant à eux, toujours présents dans le discours des individus. De plus, ces principes semblent détenir une portée normative de taille quant à la redéfinition de l’articulation des temporalités sociales : d’une sécurité de l’emploi, nous serions en train d’effectuer un glissement vers une sécurité en emploi de l’individu. La rhétorique n’est pas innocente : désormais, ce n’est plus tant l’individu qu’il s’agit de protéger (droit du travail, etc.) mais bien les transitions – multiples et sinueuses – opérées par ce dernier. Pour y parvenir, l’État le responsabilise : il doit désormais être capable de se prendre en mains : « c’est le passage d’un ‘État qui protège’ à un ‘État qui rend capable’ » (Vrancken, 2008). [less ▲]

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See detailGay and Lesbian Families Well-Beeing: Respectively Ten and Seven years after the legalization of Same-sex Marriage and Same-sex Adoption in Belgium, understanding heterosexual adults' attitudes.
Scali, Thérèse ULg; D'Amore, Salvatore ULg; Green, Robert-Jay

Conference (2014, July)

Belgium is one of the first European country to legalize marriage and adoption for same-sex couples (respectively in 2003 and 2006) and to state anti-discrimination laws (2008). Despite the legalization ... [more ▼]

Belgium is one of the first European country to legalize marriage and adoption for same-sex couples (respectively in 2003 and 2006) and to state anti-discrimination laws (2008). Despite the legalization, what can we say about adults’ attitudes? This study is part of an international project, and aims at studying the attitudes towards different kind of same-sex constellations – single gays and lesbians, couples, and families – and at examining the correlates to those attitudes. Attitudes were assessed through self-report questionnaires in a cohort of 366 heterosexual participants resident in Belgium, 72% females and 28% males aged from 26 to 40 (age class corresponding to transition lifecycle and parenting choices). Participants were asked to answer socio-demographic questions and to self-report their contact with homosexual people (frequency and satisfaction). Then different scales assessed their attitudes toward homosexuality (General Attitudes Toward Homosexuality, Da Costa, 2011; ATLG, Herek), same-sex marriage (Katuzny Scale on Same-Sex Marriage, 2012) and different types of same¬-sex parenting – adoption, alternative insemination, in vitro, ovocyte donation (D’Amore & Green Homoparentality Scale, 2012). It is hypothesized that correlates to positive attitudes will be associated with female gender, lower religiosity, non-protestant religions, liberal political ideology, and higher education and socioeconomic status. This presentation contributes to a better understanding of Belgian’s attitudes toward same-sex couples and same-sex families, by measuring the predictive variables of positive and negative attitudes. [less ▲]

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See detailEvaluation of process-driven spray retention model on ear-ly growth stage barley
Massinon, Mathieu ULg; Ouled Taleb Salah, Sofiene ULg; De Cock, Nicolas ULg et al

Conference (2014, July)

The efficiency of spray application of foliar plant protection products with hydraulic nozzles on vertically oriented and hydrophobic plants at early growth stages can be very low. The spray retention by ... [more ▼]

The efficiency of spray application of foliar plant protection products with hydraulic nozzles on vertically oriented and hydrophobic plants at early growth stages can be very low. The spray retention by crop leaves is affected by application parameters resulting from nozzle kind, size and operating pressure as well as spray mixture physicochemical properties. When optimizing the spray application, such targets are often used to perform retention trials for comparative purpose, i.e. indoor grown monocotyledonous at two leaves stage. A typical arrangement consists in spraying few plants sufficiently spaced underneath the nozzle to avoid interference due to secondary droplets from impacts on other plants. However, retention trials turn out to ineffective for significantly discriminating between application methods and mixtures due to the high variability between trials resulting from the different droplets retained by each plant. An alternative to retention trials is to tackle spray retention with a physical approach at the droplet scale. Such tests are often performed using high speed imaging with high magnification optics to characterize droplet impacts; adhesion, rebound or shatter on small excised leaf areas and neglect, however, the overall plant architecture. The aim of this paper is to evaluate a droplet interception model connecting actual spray retention with process-driven retention models. In this study, barley plants (BBCH11) were sprayed with 2 formulations using the same nozzle. The actual spray retention was assessed by dosing a fluorescent tracer added to the sprayed mixture. The plants were placed linearly below the center of a single moving nozzle during sprayings. Each plant was reconstructed in 3D afterwards using a structured light 3D scanner and used as input for the model. A virtual nozzle was built on the base of droplet size distributions measured with high speed shadow imaging by performing an adjustment of the distribution by the method of moments. A ran-dom droplet distribution was allocated for each spraying of a barley plant. Droplet velocities were given to droplets on the basis of the droplet velocity – diameter correlation by resolving the droplet transport equations for different droplet sizes. Initial droplet positions were ran-domly given. The interception model is based on a mathematical formalism for the intercep-tion between triangles of the 3D plant and droplet directions. If the droplet impacts a leaf, the amount actually retained by the leaf was computed on the basis of the droplet impact energy and impact behavior from experiments with high speed shadow imaging. In conclusion, the interception model allowed determining the spray retention by plants and discriminating ap-plication parameters by explaining the variability resulting from various droplet size distribu-tions intercepted by single plant. [less ▲]

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See detailIdentifying codes in vertex-transitive graphs
Gravier, Sylvain; Parreau, Aline ULg; Rottey, Sara et al

Conference (2014, July)

We consider the problem of computing identifying codes of graphs and its fractional relaxation. The ratio between the optimal integer and fractional solutions is between 1 and 2 log(|V|) where V is the ... [more ▼]

We consider the problem of computing identifying codes of graphs and its fractional relaxation. The ratio between the optimal integer and fractional solutions is between 1 and 2 log(|V|) where V is the set of vertices of the graph. We focus on vertex-transitive graphs for which we can compute the exact fractional solution. There are known examples of vertex-transitive graphs that reach both bounds. We exhibit infinite families of vertex-transitive graphs with integer and fractional identifying codes of order |V|^a with a in {1/4, 1/3, 2/5}. These families are generalized quadrangles (strongly regular graphs based on finite geometries). They also provide examples for metric dimension of graphs. [less ▲]

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See detailOrthanc - Logiciel libre pour l'imagerie médicale en milieu hospitalier
JODOGNE, Sébastien ULg; LENAERTS, Eric ULg; COUCKE, Philippe ULg et al

in Communications de la Conférence Francophone en Gestion et Ingénierie des Systèmes Hospitaliers (GISEH 2014) (2014, July)

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See detailThe Amik Lake in Southern Turkey over the last 4000 years, a new paleoseismological record of ruptures along the Northern Dead Sea Fault
Hubert, Aurelia ULg; El Ouahabi, Meriam ULg; Lebeau, Hèlène et al

Poster (2014, June 30)

The study focuses on the sedimentary record of the Amik Lake occupying the central part of a pull-apart basin. The Basin is crossed by The Dead Sea Fault (DSF), a major neotectonic structure in the Middle ... [more ▼]

The study focuses on the sedimentary record of the Amik Lake occupying the central part of a pull-apart basin. The Basin is crossed by The Dead Sea Fault (DSF), a major neotectonic structure in the Middle East extending from the Red Sea in the south to the East Anatolian Fault Zone in the north. Around the Amik Basin, continuous human occupation is attested since 6000-7000 BC. Indeed the low-lying Amuq plain is covered by tell settlements first explored by Robert Braidwood in the 1930s. Our objective in this presentation is to look at major paleo-environmental changes recorded in the Amik Lake over the last 4000 years and in particular its potential paleoseimic sedimentary record. The lake has been drained and progressively dried up since the mid-50s so that it is not watered during the summer season and constitutes a unique opportunity to collect sediment records. Sediments were collected at 1 cm to 2 cm intervals in a trench and in cores up to a depth of 5 meters in the clay deposits. A diverse array of complementary methods is applied to study the records: magnetic susceptibility, grain size, organic matter and inorganic carbon (L.O.I), XRD mineralogy, XRF geochemistry, carbon geochemistry and clay mineralogy. The age of the record is constrained combining radionuclide and radiocarbon dating. The sedimentary record shows large earthquake related structural disturbances and smaller siliciclastic sedimentary events. The siliciclastic input would be related to enhanced detritical sedimentation related to earthquake shaking. The latter is further investigated looking at intensities and shake maps related to the last 19th century M>7 earthquakes in the area and landslide prone area in the lake catchment. [less ▲]

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See detailLe questionnaire en recherche !
Pétré, Benoît ULg; Guillaume, Michèle ULg

Conference (2014, June 28)

Les pratiques médicales et paramédicales doivent prendre appui aujourd’hui sur les données dites probantes. Autrement dit, les données issues de la recherche guident l’action des professionnels de santé ... [more ▼]

Les pratiques médicales et paramédicales doivent prendre appui aujourd’hui sur les données dites probantes. Autrement dit, les données issues de la recherche guident l’action des professionnels de santé! La qualité des résultats attendus au terme d’un processus de recherche dépend profondément de la qualité de l’outil de collecte des données utilisé. Parmi les outils disponibles, le questionnaire est certainement celui le plus utilisé dans le domaine de la recherche médicale et paramédicale. Si la conception d’un questionnaire parait simple aux premiers abords, une lecture plus fine des principes qui sous-tendent la mesure (fidélité, validité, objectivité) rend compte des difficultés rencontrées pour développer un outil de qualité. Après avoir resitué le questionnaire dans le processus plus général de la recherche, les étapes de construction du questionnaire seront précisées et les qualités de l’outil seront discutées. Cette présentation permettra la mise en lumière des avantages et des limites inhérentes au questionnaire. Il sera démontré que nul questionnaire n’est parfait et que les inférences et les interprétations qui peuvent être tirées des informations recueillies à partir de cet outil, doivent être réalisées avec précaution. [less ▲]

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See detailLes botanistes verviétois au XIXème siècle
Genin, Vincent ULg

Conference (2014, June 28)

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See detailWorkshop on Pitch Analysis for Singing
Larrouy, Pauline ULg

Conference (2014, June 28)

Two methods are actually used in order to determine if a vocal performance is “in tune” or “out of tune”, to better understand the causes of poor-pitch singing or to evaluate the quality/progression of a ... [more ▼]

Two methods are actually used in order to determine if a vocal performance is “in tune” or “out of tune”, to better understand the causes of poor-pitch singing or to evaluate the quality/progression of a singer. The "subjective" method makes use of judges whereas the "objective" method uses computer tools to perform pitch analysis and to estimate the accuracy of sung performances. While the first method allows a rapid assessment, it lacks precision, which explains that the “objective” method seems currently preferred. However, several computer tools are available and each laboratory has its preference. In addition, the analytical procedure will depend on the purpose and data of the study. This workshop aims to provide an overview of the tools available and to discuss the advantages and limitations of existing methods. [less ▲]

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See detailPitch fluctuations in accurate and inaccurate singers: are they the same?
Larrouy, Pauline ULg; Pfordresher, Peter Q

Conference (2014, June 28)

The research presented here attempts to explore the fine-control of pitch during singing among accurate occasional singers and individuals whose singing reflects a Vocal Pitch Imitation Deficit (VPID ... [more ▼]

The research presented here attempts to explore the fine-control of pitch during singing among accurate occasional singers and individuals whose singing reflects a Vocal Pitch Imitation Deficit (VPID). Most past research addresses individual differences at the level of entire sung notes or melodies. By contrast, in the present research we addressed whether VPID singers differ from accurate singers with respect to the way to reach, maintain, and stop a sung tone. In order to describe the “scoops” at the beginning and ends of tone, as well as other forms of instability, we adapted the model of Large et al. (2002), originally designed to model entrainment of timing during synchronization. This model was applied to 1461 notes performed by 12 VPID and 17 accurate singers from the database of Pfordresher and Mantell (2014). Finally, the parameter values across the VPID and accurate singers were compared. The results showed that the model fits tones performed by accurate and VPID singers similarly well. As expected, the median pitch across the entire sung note deviated from the target to imitate for VPID singers; at the same time, the proportion of these deviations that were overshoots (“sharp”) versus undershoots (“flat”) were the same for VPID and accurate singers (2/3rd under and 1/3rd above). Thus accurate and VPID singers differ in the magnitude but not the type of overall deviation they exhibit. Whereas no difference occurred between the singers regarding the direction of the scoop (up or down) at the start and the end of the tone, the amplitude of the scoops was significantly different between VPID and accurate singers. The present study highlights the difficulty of VPID singers to reach and stop a sung tone, which supports the hypothesis of a fine motor control deficit in this population. Furthermore, the pitch fluctuations described by the model would have to be investigated in research on pitch accuracy perception. [less ▲]

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See detailL’ancrage dans les herbiers à Posidonia oceanica. Conséquences chimiques de la destruction mécanique ?
Abadie, Arnaud ULg

Poster (2014, June 26)

La plante marine endémique de Méditerranée Posidonia oceanica, ou posidonie, forme en Corse des herbiers colonisant les substrats depuis la surface jusqu’à 40 m de profondeur. Ces herbiers constituent un ... [more ▼]

La plante marine endémique de Méditerranée Posidonia oceanica, ou posidonie, forme en Corse des herbiers colonisant les substrats depuis la surface jusqu’à 40 m de profondeur. Ces herbiers constituent un véritable écosystème, l’un des plus riches en espèces de Méditerranée. Ils jouent un rôle écologique essentiel en oxygénant le milieu grâce à la photosynthèse et en séquestrant du CO2 au sein de leur complexe racinaire dans le sédiment (ou "matte"). Ces activités métaboliques entraînent une importante modification des conditions biogéochimiques du substrat qui favorisent le maintien de la plante. Les herbiers ont également une grande importance économique servant de nurserie pour de nombreuses espèces exploitées par la pêche commerciale et récréative. Les herbiers de posidonie se développant dans les zones côtières, ils sont impactés par les activités anthropiques (urbanisation, pollution, fermes aquacoles, ancrage) qui peuvent entraîner d’importantes destructions et des régressions de leur zone de recouvrement. L’ancrage intensif dans les herbiers à faible profondeur y génère des trouées, ou "intermattes". Les destructions engendrées par les navires de petite taille (< 10 m) peuvent, dans certaines conditions, être recolonisées par la posidonie. Cependant, dans la plupart des zones d’ancrage intensif en Corse, les intermattes ne sont pas recolonisées et leur surface peut souvent augmenter. De plus, certaines zones sont soumises à l’ancrage intensif de navires de plaisance de grande taille (> 20m), susceptibles de générer des intermattes d’une étendue plus importante. Ce phénomène d’expansion ne peut s’expliquer par la seule destruction mécanique. L’arrachage de la strate foliaire de la posidonie par les ancres semble entraîner de profondes modifications physiques et chimiques dans le sédiment. La photosynthèse via les feuilles étant ainsi altérée, il n’y a plus d’oxygénation du sédiment via les racines de la posidonie et un milieu anoxique défavorable à son développement paraît se créer. Des composés toxiques pour la plante, tel que le sulfure d’hydrogène (H2S), pourraient alors s’introduire dans ses tissues entraînant une limitation de son développement, voire sa disparition menant ainsi à une amplification des dégâts mécaniques de l’ancrage. Des observations seront réalisées tout autour de la Corse et notamment dans la Baie de Calvi, site atelier de la Méditerranée, qui a été définie pour mener la phase d’expérimentation. Les données récoltées à l’issue de ces travaux de recherches, réalisés dans le cadre d’un doctorat en entreprise (bourse CIFRE), seront compilées afin de mettre au point de nouveaux outils d’analyse de l’impact de l’ancrage. [less ▲]

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See detailPLANTIGRADY DUE TO A LOCALIZED MYOPATHY IN TWO NEWBORN BELGIAN BLUE CALVES
Genart, Marie; Evrard, Laurence ULg; Garcia da Fonseca et al

Poster (2014, June 26)

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See detailA probabilistic model of the adhesive contact forces between rough surfaces in the MEMS stiction context
Hoang Truong, Vinh ULg; Wu, Ling ULg; Arnst, Maarten ULg et al

Conference (2014, June 26)

Stiction is a common failure mechanism in microelectromechanical systems (MEMS) in which two interacting bodies permanently adhere together. This problem is due to the comparability of adhesive surface ... [more ▼]

Stiction is a common failure mechanism in microelectromechanical systems (MEMS) in which two interacting bodies permanently adhere together. This problem is due to the comparability of adhesive surface forces (e.g. Van der Waals forces, capillary forces) and body forces in the MEMS context. To predict the adhesive contact forces coupled with stiction phenomenon, the combination of the Nayak statistical approach with the asperity-based theories is a common solution. However, this method contains some limitations due to the underlying assumptions: infinite size of the interacting rough surfaces and negligibility of asperity interactions. Furthermore, the Nayak solution suffers from a considerable dependency on the choice of the minimum wave length considered in the surface representation, which remains diXcult to select. The main goal of our research is to propose an improved method (i) which accounts for the Vnite size of the interacting surfaces, (ii) accounts for the uncertainties related to these surface topologies, (iii) in which the minimum wave length selection is physically based, and (iv) in which the validity of the asperity-based theories is demonstrated. From the topology measurements of MEMS samples, an analysis of the power spectral density function is carried out to determine the minimum relevant wave length for the problem of interest (here capillary stiction). We also show that at this scale of interest the asperity-based theories remain valid for polysilicon materials. Moreover, instead of considering inVnite surfaces as in the Nayak approach, a set of surfaces, whose sizes are representative of the MEMS structure, is generated based on the approximated power spectral density analysis and using the Monte Carlo method. From this description of the contacting surfaces, the adhesive contact forces can be evaluated by applying the asperity contact theories, leading to a probabilistic distribution of the adhesive contact forces. In addition, as the contact forces are rooted from the micro-scale adhesive forces, while their consequence, stiction, happens at the macro-scale of the considered device, the multi-scale nature of the phenomenon is accounted for. To predict this macro-scale behavior in a probabilistic form, the uncertainty quantiVcation process is coupled with a multiscale analysis. [less ▲]

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See detailBone markers in patients with CKD
CAVALIER, Etienne ULg

Conference (2014, June 26)

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See detailVehicle routing problems with multiple trips: using specific local search operators
Arda, Yasemin ULg; Crama, Yves ULg; François, Véronique ULg et al

Conference (2014, June 25)

In vehicle routing problems with multiple trips (VRPM), each vehicle is allowed to perform more than one trip during its working period. Classical solution techniques for this problem make use of existing ... [more ▼]

In vehicle routing problems with multiple trips (VRPM), each vehicle is allowed to perform more than one trip during its working period. Classical solution techniques for this problem make use of existing VRP heuristics to create trips, together with bin packing methods aimed at assigning these trips to the available vehicles. The first contribution of this work is to propose specific local search operators for the VRPM. The operators directly integrate the multi-trip structure of the problem within well-known VRP operators. As a second contribution, heuristics using these operators are compared with classical solution techniques mentioned above. The comparison is performed by using the adaptive large neighborhood search metaheuristic as a common basis for both methods. The most classical version of the problem is studied as well as a variant involving time windows [less ▲]

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See detailTurning land to livelihood : what are the socio-economic and institutional determinations of local land use in Red River Delta region ?
Nguyen Thi, Dien; Lebailly, Philippe ULg; Vu Dinh, Ton

Conference (2014, June 24)

This research analyzes the determinations of household land use strategy in the context of the rapid rural changes due to the industrialization and urbanization in Vietnam. The mechanism that turns land ... [more ▼]

This research analyzes the determinations of household land use strategy in the context of the rapid rural changes due to the industrialization and urbanization in Vietnam. The mechanism that turns land to livelihood from both productive and non-productive processes is investigated to understand the different land use strategies of smallholders in Red River Delta region. Based on the presence of migrating members, the total selected 191 households in Hai Duong province were divided into 3 different groups to do the surveys. The research results show that local land use strategies are various in which 79.06% of surveyed households maintain the allocated land for agricultural production while 65.97% of households leave land idly at least once a year. The factors from productive process such as small landholding, high production cost and overall downward income from agricultural production meantime the greater opportunities from non-farm jobs are the main socio-economical determinations of agricultural land abandonment or less effective use. The security questions of shifting livelihood between farming and non – farming sectors, the inter-household arrangements, the social supports and the institutional constraints are non-productive elements that make the exchange and other forms of commercializing agricultural land are less prominent. The complexity of household land use strategy and its determinations not only reflects the dynamism and flexibility of peasant’s livelihood adaptation but also explain why the land concentration does not proceed faster in Red River Delta region of Vietnam. [less ▲]

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See detailA Phylogenomic analysis of the origin of plastids
Cornet, Luc ULg; Javaux, Emmanuelle ULg; Wilmotte, Annick ULg et al

Conference (2014, June 24)

Cyanobacteria are a morphologically diverse phylum, with their first occurrence dating from the Precambrian. Oxygenic photosynthesis appeared in this group during the same geological period. Several ... [more ▼]

Cyanobacteria are a morphologically diverse phylum, with their first occurrence dating from the Precambrian. Oxygenic photosynthesis appeared in this group during the same geological period. Several publications have established, without any doubt, that plastids (both primary and complex) form a monophyletic ensemble emerging from Cyanobacteria. However, the exact position of plastids within Cyanobacteria is still uncertain, with several recent papers leading to very different hypotheses. Here we present a phylogenomic analysis of the origin of plastids. Our study takes advantage of all the available genomes and thus represents the best taxonomic sampling seen so far: 140 genomes of Cyanobacteria, 101 genomes of plastids and 27 outgroups taken in Melainabacteria and Chloroflexi. It results in an analysis using state-of-the-art methods (e.g., orthology assessment using USEARCH and OrthoMCL, phylogenetic inference using CAT and CAT-GTR models) based on more than 160 protein alignments totalizing over 20,000 unambiguously aligned amino acids. To confirm our results, we performed gene jackknife inferences and gene reconciliation analyses on the same dataset. We expect that out approach accounts for potential phylogenetic artefacts due to changes in the evolutionary process having occurred when the guest cyanobacterium became an endosymbiont and eventually a plastid. Meanwhile, we improve the phylogeny of Cyanobacteria per se, notably because of the presence of Melainabacteria in our dataset. [less ▲]

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See detailProbing the conformational changes during desolvation of ions using orthogonal mobility methods (CE-IM MS)
Far, Johann ULg; Kune, Christopher ULg; Delvaux, Cédric ULg et al

Poster (2014, June 24)

Routine analyses using Mass Spectrometry (MS) detection became a very popular due to the low limit of detection, great sensitivity, selectivity and specificity. Moreover MS enables structural elucidation ... [more ▼]

Routine analyses using Mass Spectrometry (MS) detection became a very popular due to the low limit of detection, great sensitivity, selectivity and specificity. Moreover MS enables structural elucidation and physical (or physicochemical) properties determination using low amount of not especially pure samples. One of these properties is substantially the stoichiometry determination of non-covalent complexes such as Ligand receptor systems (e.g. DNA-drugs, Hormones/drugs-receptor, quaternary structure arrangement of polypeptides, …). MS determination in native condition (Native MS) of this stoichiometry allows large scale screening of potential drugs candidates in pharmaceutical context. The addition of Ion-Mobility (IM) to mass spectrometry (IM-MS) with computational chemistry support allows the structural conformation monitoring (as Collisional Cross Section or CCS) and the elucidation of interactions of the non-covalent complexes. Nonetheless such determinations suppose/assume that desolvation steps and gas phase transfer during MS detection do not modify the tridimensional structure of these systems or the magnitude order of the involved interactions (dipole-dipole, dipole-ion, ion-ion, hydrophobic interactions). Further studies (Circular Dichroism, Nuclear Magnetic resonance, UV-Visible spectra …) are generally required to confirm the MS data but there are unfortunately time consuming. This project proposes the coupling of Capillary Electrophoresis (CE) to IM-MS in order to obtain in one injection the quantitative and qualitative data of non-covalent complexes and the monitoring of tridimensional conformation modification between the liquid and gas phase. Indeed CE allows the determination of numerous physicochemical properties (dissociation constant, pK values, hydrodynamic radius determination …). The structural data (i.e. hydrodynamic radius and CCS) are compared to the data obtained by IM-MS as a proof of concept using tryptic digest of Bovine Serum Albumine (BSA). [less ▲]

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See detailStandardisation of 25(OH)-vitamin D assays: beware of limitations
CAVALIER, Etienne ULg

Conference (2014, June 24)

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See detailEvaluation of SFC interest for the determination of cholecalciferol and its impurities un pharmaceuticals
Andri, Bertyl ULg; Dispas, Amandine ULg; Klinkenberg, Régis et al

Poster (2014, June 23)

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See detailGeneration of artificial magnetic fields using dipole-dipole interactions
Cesa, Alexandre ULg; Martin, John ULg

Poster (2014, June 23)

In 1996, Lloyd [1] showed that the dynamics of complex many-body quantum systems can be efficiently simulated by quantum computers, an idea first put forward by Manin [2] and further developed by Feynman ... [more ▼]

In 1996, Lloyd [1] showed that the dynamics of complex many-body quantum systems can be efficiently simulated by quantum computers, an idea first put forward by Manin [2] and further developed by Feynman [3]. Although the first quantum computers of a few qubits have been realised experimentally [4, 5], the advent of scalable quantum computers might take another few decades. An alternative tool in the context of simulation is a highly controllable quantum system able to mimic the dynamics of other complex quantum systems, known as an analog quantum simulator. Cold neutral atoms and trapped ions have been shown to be versatile quantum simulators [6, 7] thanks to their high flexibility, controllability, and scalability. They permit one to study a wide range of problems arising from atomic physics, relativistic quantum physics, or cosmology [8]. Since neutral atoms do not carry any net charge, the simulation of electric and magnetic condensed matter phenomena, such as the spin Hall effect, seems out of reach. To overcome this apparent difficulty, the idea has been proposed to create artificial electromagnetic potentials for neutral atoms based on atom-light interaction [9– 12]. These artificial potentials act on neutral atoms as real electromagnetic potentials act on charged particles. Many works on artificial gauge potentials induced by atom-light interactions adopt a single-particle approach [12]. The predicted potentials are then supposed to be valid for a system of weakly interacting atoms. So far, the consequences of atom-atom interactions on the generation of artificial gauge fields has little been studied. The aim of this work is to study the artificial gauge fields arising from the interaction of two Rydberg atoms driven by a common laser field [13]. In this situation, we show that the combined atom-atom and atom-field interactions give rise to nonuniform, artificial gauge potentials. We identify the mechanism responsible for the emergence of these gauge potentials. Analytical expressions for the latter indicate that the strongest artificial magnetic fields are reached in the regime intermediate between the dipole blockade regime and the regime in which the atoms are sufficiently far apart such that atom-light interaction dominates over atom-atom interactions. We discuss the differences and similarities of artificial gauge fields originating from resonant dipole-dipole [14] and van der Waals [15] interactions. We also give an estimation of experimentally attainable artificial magnetic fields resulting from this mechanism and we discuss their detection through the deflection of the atomic motion. [1] S. Lloyd, Science 273, 1073 (1996). [2] Yu. I. Manin, Computable and uncomputable, Sovetskoye Radio, Moscow, 1980. [3] R. P. Feynman, Int. J. Theor. Phys. 21, 467 (1982). [4] L. DiCarlo, J. M. Chow, J. M. Gambetta, Lev S. Bishop, B. R. Johnson, D. I. Schuster, J. Majer, A. Blais, L. Frunzio, S. M. Girvin, and R. J. Schoelkopf, Nature 460, 240 (2009). [5] N. Xu, J. Zhu, D. Lu, X. Zhou, X. Peng, and J. Du, Phys. Rev. Lett. 108, 130501 (2012). [6] I. Buluta and F. Nori, Science 326, 108 (2009). [7] I. Bloch, J. Dalibard and S. Nascimbéne, Nature Physics 8, 267 (2012). [8] R. Blatt and C. F. Roos, Nature Physics 8, 277 (2012). [9] G. Juzeliunas and P. Öhberg, Phys. Rev. Lett. 93, 033602 (2004). [10] G. Juzeliunas, P. Öhberg, J. Ruseckas, and A. Klein, Phys. Rev. A 71, 053614 (2005). [11] G. Juzeliunas, J. Ruseckas, P. Öhberg, and M. Fleischhauer, Phys. Rev. A 73, 025602 (2006). [12] J. Dalibard, F. Gerbier, G. Juzeliu ̄nas, and P. Öhberg, Rev. Mod. Phys. 83, 1523 (2011). [13] A. Cesa and J. Martin, Phys. Rev. A 88,062703 (2013). [14] A. Gaëtan, Y. Miroshnychenko, T. Wilk, A. Chotia, M. Viteau, D. Comparat, P. Pillet, A. Browaeys, and P. Grangier, Nature Physics 5, 115 (2009). [15] L. Béguin, A. Vernier, R. Chicireanu, T. Lahaye, and A. Browaeys, Phys. Rev. Lett. 110, 263201 (2013). [less ▲]

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See detailDevelopment of a multiplexed surface-enhanced Raman scattering quantitative approach for bisphenols detection
De Bleye, Charlotte ULg; Dumont, Elodie ULg; Sacre, Pierre-Yves ULg et al

Conference (2014, June 23)

Over the last decade, bisphenol A (BPA) attracted a lot of attention. This molecule, commonly used as a precursor to produce epoxy-resin and plastics, is an endocrine disruptor presenting an estrogenic ... [more ▼]

Over the last decade, bisphenol A (BPA) attracted a lot of attention. This molecule, commonly used as a precursor to produce epoxy-resin and plastics, is an endocrine disruptor presenting an estrogenic activity [1]. Despite its health toxicity, BPA is present in a broad variety of consumer goods released from plastic bottles and packaging for example. Since the discovery of its adverse health effect of BPA, the manufacturers tend to use structural analogues of BPA such as BPS, BPF and BPB to produce plastic materials [2]. However, the health safety of these molecules is still not demonstrated. Currently, bisphenols are actively researched and quantified using solid phase extraction and chromatography techniques which are time and solvents consuming. Therefore, it could be very interesting to quantify simultaneously bisphenols using a fast and “green” technique. Surface-enhanced Raman scattering (SERS) exalts dramatically the Raman scattering of molecules adsorbed or very closed to metallic surface enabling to detect very low amounts of analytes while keeping the structural information obtained from the spectrum which is very interesting to consider multiplexed analyses [3-4]. Moreover, SERS, which is a solvent free and fast acquisition technique, is an attractive tool in “Green Chemistry” [5]. In this context, the development of a multiplexed quantitative approach to detect bisphenol was considered. Silver nanoparticles (AgNps) were selected as SERS substrate and their functionalization was investigated taking into account the weak affinity of phenolic molecules for gold and silver surface [6]. Pyridine was selected as surface modifier and allowed to attract bisphenols around metallic surface thanks to hydrophobic interaction and hydrogen bonds [7]. Afterwards, the SERS samples preparation was optimized playing on the concentrations of pyridine and aggregating agent used to get the nanoparticles closer to each other which promotes the SERS effect. Tap water samples were spiked with different concentration of BPA from 5 ppb to 1000 ppb and analyzed using the optimized SERS sample preparation. A good linearity of the response was observed and a calibration curve with coefficient of determination (R2) of 0.9922 was obtained by plotting the intensity of a principal band of BPA versus the concentration. This last step was repeated using BPB as analyte and a calibration curve with a R2 of 0.9991 was obtained for the same range of concentration using a specific band intensity of BPB. Finally, tap water samples were spiked with different concentrations of BPA and BPB simultaneously and analyzed using SERS and it was possible to detect selectively the two molecules thanks to specific bands and a good linearity of the response was observed for both. To conclude, promising results were obtained which pave the way to “green” multiplexed quantitative analyses of very low concentrated analytes using SERS. References: [1] J.-H. Kang et al., Toxicology 226 (2006) 79-89 [2] C. Liao et al., J. Agric. Food Chem. 61 (2013) 4655-4662 [3] K. Kneipp et al., Chem. Rev. 99 (1999) 2957-2975. [4] R.F. Aroca et al., Adv.Colloid Interface Sci. 116 (2005) 45-61. [5] C. De Bleye et al., Talanta 116 (2013) 899-905. [6] X.X. Han et al., Anal. Chem., 83 (2011) 8582-8588. [7] B. San Vicente et al., Anal. Bioanal. Chem. 380 (2004) 115-122. [less ▲]

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See detailSymmetric N-qubit anticoherent states
Baguette, Dorian ULg; Bastin, Thierry ULg; Martin, John ULg

Poster (2014, June 23)

Entanglement is among the key features of quantum mechanics. In the last decade, a lot of efforts has been made to quantify the amount of entanglement of various multipartite states, either pure or mixed ... [more ▼]

Entanglement is among the key features of quantum mechanics. In the last decade, a lot of efforts has been made to quantify the amount of entanglement of various multipartite states, either pure or mixed. In particular, the search for maximally entangled states (states maximizing certain measures of entanglement) has focused a great deal of attention, see e.g. Refs. [1–4]. In this work, we present a comprehensive study of maximally entangled symmetric N-qubit states with respect to the definition of Gisin [1]. According to this definition, a state is maximally entangled if all its one-qubit reduced density matrices are maximally mixed. These states maximize various entanglement measures, such as von Neumann and Meyer-Wallach entropies [5]. They are unique up to local unitaries within the class of states interconvertible under stochastic local operations and classical communication (SLOCC) [3]. Besides, they are conjectured to be maximally entangled with respect to the Negative Partial Transpose measure of entanglement [6]. As appreciated by B. Kraus, they play an important role in the determination of the local unitary equivalence of multiqubit states [7]. Moreover, they are maximally fragile (in the sense that they are the states which are the most sensitive to noise) and therefore have been proposed as ideal candidates for ultrasensitive sensors [1]. We provide general conditions for a symmetric state with an arbitrary number of qubits to be maximally entangled and identify families of SLOCC classes which do not contain any such states. We also compute various measure of entanglement associated with those states in order to characterize them further and find all maximally entangled states up to 4 qubits. We finally prove that maximally entangled states coincide with anticoherent states of order 1. According to the definition of Ref. [8], a symmetric state of N qubits is anticoherent to order t iff 〈(S·n)k〉 is independent of n for k = 1, . . . , t where n is a tridimensional unit vector and S is the collective spin operator associated to the N-qubit system. [1] N. Gisin, H. Bechmann-Pasquinucci, Phys. Lett. A 246 (1998). [2] A. Higuchi, A. Sudbery, Phys. Lett. A, 272, 213 (2000). [3] F. Verstraete, J. Dehaene, B. De Moor, Phys. Rev. A 68, 012103 (2003). [4] J. Martin, O. Giraud, P. A. Braun, D. Braun and T. Bastin, Phys. Rev. A 81, 062347 (2010). [5] D. A. Meyer, N. R. Wallach, J. Math. Phys. 43, 4273 (2002). [6] I. D. K. Brown, S. Stepney, A. Sudbery, and S. L. Braunstein, J. Phys. A 38, 1119 (2005). [7] B. Kraus, Phys. Rev. Lett. 104, 020504 (2010). [8] J. Zimba, EJTP 3, 10 (2006). [less ▲]

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See detailAlteration of decoherence-free states caused by dipole-dipole interactions
Damanet, François ULg; Martin, John ULg

Poster (2014, June 23)

Decoherence, known as the consequence of the coupling of any quantum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quantum ... [more ▼]

Decoherence, known as the consequence of the coupling of any quantum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quantum computers [1]. Decoherence-Free States (DFS) are considered as a possible solution to this problem. A set of trapped cold atoms placed in a DFS state will be immune against decoherence due to spontaneous emission. However, because of dipole-dipole interactions between atoms, induced dephasing effects are likely to destroy the coherence and drive the system out of its DFS [1, 2]. In this work, we study numerically the dynamics of a set of two-level atoms initially in a DFS with respect to dissipative processes by solving the master equation including both dissipative dynamics and dipole dipole interactions. We fo- cus our attention on the infuence of dipolar coupling on the radiated energy rate and coherence of the system as in [3]. In particular, by averaging over many realizations of close randomly distributed atomic positions, we show the formation of a superradiant-like pulse and we study its properties as a function of the dipolar coupling strength. [1] D. A. Lidar & K. B. Whaley, Lectures Notes in Phys., Vol. 622, p83-120, Springer (2003). [2] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [3] W. Feng, Y. Li & S-Y. Zhu, Phys. Rev. A 88, 033856 (2013). [less ▲]

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See detailNMR in the Pharmaceutical and Biomedical areas for identification and quantification of drugs and metabolomics applications
LAMBERT, Vincent ULg; Dufour, Gilles ULg; Chiap, Patrice ULg et al

Conference (2014, June 23)

Nuclear Magnetic Resonance (NMR) is probably, with mass spectrometry, the most powerful analytical tool for the structural determination of organic compounds. For a long time and due to technical ... [more ▼]

Nuclear Magnetic Resonance (NMR) is probably, with mass spectrometry, the most powerful analytical tool for the structural determination of organic compounds. For a long time and due to technical limitations, the main applications of NMR were focused on chemistry (organic, inorganic and medicinal chemistry) or biochemistry (i.e. proteins and proteins ligands analysis). Indeed, despite of very interesting potential in terms of structural information, reproducibility, specificity, quantification, NMR suffered of a lack of sensitivity and sometime of resolution in the case of complex mixture analysis in comparison with other technics. However, since several years, important technical improvements such as huge increase in sensitivity, hyphenation of NMR with LC system, automation and development of 2D and presaturation sequences have opened new putative applications for NMR, specifically in the pharmaceutical and biomedical areas. Then, beside the mass and chromatographic technics classically used for drug analysis, NMR represents an interesting and complementary tool for many applications. In this presentation, we will describe some NMR applications related to the pharma area. Starting from the identification of xenobiotic metabolites by coupling LC-SPE-NMR data with LC-MS/MS results, quantification of cyclodextrines in complex media, identification of illicit compounds, we will finish with our recent metabolomics NMR developments. [less ▲]

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See detailThe Belgian Tetris: assessing the political impact of metaphors on citizens' perceptions of Belgian federalism
Perrez, Julien ULg; Reuchamps, Min

Conference (2014, June 20)

In the literature, the political impact of metaphors has often been taken for granted from metaphor analysis in political discourse, be it elite discourse or media discourse. However, a more global ... [more ▼]

In the literature, the political impact of metaphors has often been taken for granted from metaphor analysis in political discourse, be it elite discourse or media discourse. However, a more global understanding of what this political impact could consist of, is still lacking from the current research agenda. As Koller (2009:121) puts it: “metaphor helps construct particular aspects of reality and reproduce (or subvert) dominant schemas.” To be able to account for how metaphors, through discourses, actively shape the political reality, it is important to look at the relationships between metaphorical discourses and their environment. Based on the idea that metaphors do not only reflect the perceived reality, but also function as cues through which citizens come to understand complex political processes and through which they shape political behaviors, the aim of this study is precisely to look at how specific metaphors might impact on the citizens’ framing of Belgian federalism. To measure the impact of metaphors on the citizens’ political representations and attitudes, we developed an experimental set-up based on an article published in the Belgian newspaper Le Soir (13-14 July 2013) in which Belgian federalism was deliberately compared to a Tetris game. The original article included a picture and a text (208 words), which were used as authentic experimental material. For this experiment, we distinguished three experimental conditions and one control condition. In the first experimental condition (full condition), the participants were exposed to the original article (including the text and the picture). In the second and third experimental conditions, the participants were respectively exposed either to the text (text condition) or the picture (picture condition). In the control condition, the participants weren’t exposed to any metaphorical material at all. In the second stage of the experiment, the participants were asked to achieve three interrelated tasks: (i) a free description task, based on a free description of their own perception of Belgian federalism, (ii) an association task, in which they had to select a picture which they found the most appropriate to describe Belgian federalism, and finally (iii) a questionnaire measuring the participants’ political knowledge of Belgian federalism and attitudes towards its future development. In a post-test held four weeks after the first experiment, the three tasks of the second stage have been replicated. This experiment has been conducted in autumn 2013 among 400 students. Comparing the various experimental conditions will make it possible (i) to measure the impact of the Tetris metaphor on the citizens’ perceptions and representations of Belgian federalism, (ii) to assess to what extent the different metaphorical media differently contribute to this impact and (iii) to measure the long-term impact of this metaphor on the citizens’ political representations and attitudes. In answering these questions, this study will contribute to a better understanding of the role and functions metaphors play in political discourse, and more globally in our everyday political interactions. [less ▲]

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See detailUn panorama du temps. Robida chroniqueur des Expositions universelles
Stienon, Valérie ULg

Conference (2014, June 19)

Robida est familier des Expositions universelles. Sa carrière de dessinateur-journaliste est en grande partie rythmée par les événements sociaux qu’elles constituent. Il illustre le démontage de ... [more ▼]

Robida est familier des Expositions universelles. Sa carrière de dessinateur-journaliste est en grande partie rythmée par les événements sociaux qu’elles constituent. Il illustre le démontage de l’Exposition de Paris de 1867 dans le Journal Amusant du 9 novembre 1867. Il est envoyé à Vienne comme dessinateur-correspondant du Monde illustré pour celle de 1873. Il visite l’Exposition de 1889 et en rend compte en double-page dans La Vie Parisienne du 11 mai 1889 (« Demandez, l’inauguration officielle de la Tour ! »). Enfin, il participe activement à l’Exposition de 1900 avec la reconstitution minutieuse, pendant près de deux ans, du « Vieux Paris », une attraction à succès située entre le Pont de l’Alma et la passerelle Debilly. En tant que manifestation très fréquentée, qui fait l’objet d’une abondante publicité et qui engage l’image d’une ville à dimension internationale, l’exposition dans ses diverses formes (universelle, internationale, industrielle) constitue un nouveau mode de communication et un lieu de sociabilité spécifique dans la seconde moitié du XIXe siècle. Le chroniqueur, le journaliste et le dessinateur sont amenés à commenter et à représenter ce type d’événement célébratif qui implique tout à la fois une esthétique de la monstration, une rhétorique publicitaire et une réflexivité patrimoniale sur le siècle. Lieu de présentation de l’innovation, animé par un imaginaire du progrès technique et industriel, l’exposition a pu ainsi constituer une matrice féconde pour l’œuvre d’anticipation de Robida. Cette communication propose d’examiner ce que la production de Robida doit aux discours et aux représentations liés aux Expositions universelles dans les deux décennies de 1880 et 1890. Des thématisations explicites, des visites fictives en mots et en images, ainsi qu’un abondant intertexte d’actualité témoignent de ce rapport à un discours social qui traverse une œuvre conjecturale ambiguë. Si les liens thématiques du Vingtième Siècle à l’Exposition Internationale d’Électricité de 1881 sont bien connus, il faut aussi envisager les aspects de la production de Robida qui impliquent le support journalistique. C’est le cas des dessins de presse qui préparent de manière critique la réception des Expositions, comme le montre la couverture de La Caricature du 16 juin 1886 faisant, trois ans à l’avance, l’éloge paradoxal du projet de métro aérien coupable d’encombrer le ciel parisien. C’est aussi le cas des inventions moquées dans sa correspondance fictive avec le dessinateur Christophe entre 1896 et 1901 dans « La Boîte aux lettres » du Petit Français illustré, où Robida-Théodule Asenbrouck imagine des machines telles que la « pince-scie-brosse-polissoir électrique » pour découper la Lune en douze tranches afin d’éclairer les grandes capitales, en particulier la Ville-Lumière. L’Exposition constitue également un cadre de transposition fictive créatif, comme en témoigne le récit sériel Jadis chez aujourd’hui du Petit Français illustré, imaginant Louis XIV et sa cour transportés à l’Exposition universelle de 1889 et visitant la Galerie des Machines avec un regard décalé sur l’époque contemporaine. Des éléments graphiques et stylistiques récurrents résultent de ce commentaire journalistique des Expositions, à l’image d’une tour Eiffel dont un seul pied suffit à constituer un indicateur chrono-topographique symbolisant la modernité contestée. Enfin, on peut considérer comment Robida prolonge à sa manière des inventions existantes, notamment dans l’illustration du texte d’Octave Uzanne La Locomotion future, paru dans Le Monde Moderne en 1895, ou avec la voiture aéroplane déclinée à partir du quadricycle Daimler apparu à l’Exposition de 1889. Le dialogue attentif et moqueur de Robida avec les projets et les discours des Expositions universelles permet de reconsidérer l’humour de l’anticipateur en le situant plus résolument dans les registres satirique et fantaisiste propres à prendre en charge les facéties du « feu congelé », du « poney-vapeur » ou du « perce-brouillard à hélice nasale », que dans la seule prospective pessimiste d’un génial visionnaire. Cet angle d’étude de l’œuvre d’anticipation offre aussi l’occasion d’examiner la part de l’intertexte d’actualité intervenant dans une pratique générique, graphique et éditoriale du panorama temporel. Entendons par là la littérature des guides pour visiteurs d’Expositions qui renoue avec une tradition des Petits-Paris initiée dans la littérature « panoramique » des années 1840. Ces parcours-découvertes balisés et ces bilans des curiosités urbaines ne sont pas sans évoquer ceux auxquels contribue Robida dans Le Vieux Paris. Guide historique, pittoresque et anecdotique (une cinquantaine de dessins), dans l’illustration du guide satirique L’Exposition comique (Dentu, 1889) ou encore dans le récit illustré du Dix-neuvième Siècle. S’ils s’articulent à un passé patrimonial sous la forme d’un inventaire du siècle qui se regarde réflexivement, ils ont aussi pu contribuer à l’anticipation en associant scènes dynamiques et vues d’ensemble dans un parcours temporel indissociable de ses dimensions topographiques. [less ▲]

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See detailSPATIODATA, un modèle de bâtiment non-constructif, collaboratif et multi-usage
Delfosse, Vincent ULg; Boulanger, Christelle ULg; Jeunejean, Aurélie ULg et al

in Actes du 6ème Séminaire de Conception Architecturale Numérique (2014, June 19)

There is an increasing number of mobile applications supporting specific activities related to the indoor building environment. SpatioData is a research project aiming at the development of a ... [more ▼]

There is an increasing number of mobile applications supporting specific activities related to the indoor building environment. SpatioData is a research project aiming at the development of a collaborative platform for the effective sharing of building-related data and supporting a wide range of different activities. This paper discusses the specific data model at the heart of the project. A comparison with the traditional BIM models is given in order to motivate the choices made in this project. [less ▲]

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See detailContribution of ion mobility for structural analysis and analytical chemistry: Use of selective IMS shift reagents (SSR)
Kune, Christopher ULg; Far, Johann ULg; Delvaux, Cédric ULg et al

Poster (2014, June 19)

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the ... [more ▼]

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the instrumental resolution. This work proposes a new method to overcome this limitation while providing additional structural information. A Selective Shift Reagent (SSR) is a ligand specifically modifying the CCS of ions. Indeed specific non-covalent complexes can be form with a suitable SSR to reach the required selectivity and the CCS induced shift. A CID dissociation of the complex may be used after IMS separation to produce specific MS/MS spectra of the targeted analyte. This concept paves the way for new analytical strategies by ion mobility based on non-covalent complex formation. [less ▲]

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See detailLes approches sémiotiques du portrait photographique. De l’identité à l’“air”
Dondero, Maria Giulia ULg

in COnTEXTES : Revue de Sociologie de la Littérature (2014, June 18), 14

L’objectif de cet article est d’abord méthodologique : il entend déployer les instruments de l’analyse sémiotique, et notamment énonciative et temporelle, des images photographiques. Ensuite, il vise à ... [more ▼]

L’objectif de cet article est d’abord méthodologique : il entend déployer les instruments de l’analyse sémiotique, et notamment énonciative et temporelle, des images photographiques. Ensuite, il vise à esquisser la spécificité du genre du portrait et à interroger l’identification de caractéristiques singularisant le portrait d’écrivain. [less ▲]

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See detailThe search for a core functionality network in chondrocyte differentiation using heuristic and genetic algorithms
Kerkhofs, Johan ULg

Conference (2014, June 18)

Introduction: In the growth plate a continuing process where cartilage is replaced by bone provides the fuel for bone growth until its closure towards the end of puberty. At the cellular level the growth ... [more ▼]

Introduction: In the growth plate a continuing process where cartilage is replaced by bone provides the fuel for bone growth until its closure towards the end of puberty. At the cellular level the growth rate is maintained by proliferation and enlargement of maturing cells (hypertrophy). Mature cartilage cells (hypertrophic chondrocytes) secrete Ihh, a growth factor that induces expression of PTHrP, another growth factor, in immature proliferating chondrocytes. Since PTHrP in turn inhibits chondrocyte maturation, Ihh secretion limits the number of maturing chondrocytes through a negative feedback loop, striking a balance between proliferation and hypertrophy [Kronenberg, 2003]. Materials and methods: A gene network centering on the control of Ihh, PTHrP and transcription factors Sox9 and Runx2, which are the master regulators of early and late chondrocyte differentiation respectively, was manually constructed from literature. The dynamics of this network are simulated in a discrete framework that divides reactions into two speed classes. In this framework all interactions are considered additive, and each interaction is associated with a weight. Starting from the observation that the gene network must activate Runx2 in the presence of Ihh and Sox9 in the presence of Ihh and PTHrP, we investigate which edges are vital in achieving this. To this end, we employ both a heuristic and a genetic algorithm where the weights attached to the edges function as variables. In the heuristic algorithm weights are uniformly distributed in [0,1] and the means (based on 450 samples) of the weights that satisfy the above mentioned observations are contrasted with those that do not. If the difference of the means passes a certain threshold, the weight of the corresponding edge is fixed at 1. Results and discussion: Preliminary results from the heuristic algorithm show that fixing 14 weights (out of 147) is sufficient to match the biological observations in about 22% of cases, all other weights being selected randomly. The selected edges show that the BMP pathway is crucial in effecting a switch between hypertrophy in the absence of PTHrP and proliferation in its presence. This observation can be substantiated by earlier findings that BMP signalling plays a crucial role in prehypertrophic cells that are on the verge of hypertrophy [Yoon, 2006]. References: Kronenberg, 2003, Nature, 423:332-336; Yoon et al., 2006, Development, 133:4667-4678. [less ▲]

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See detailLes univers vidéoludiques : des fictions mobiles et jouables
Barnabé, Fanny ULg

Poster (2014, June 18)

La question de la fiction constitue, depuis le début des années 2000, une clef d’entrée privilégiée pour étudier le médium vidéoludique. La capacité du jeu vidéo à prendre en charge la représentation ... [more ▼]

La question de la fiction constitue, depuis le début des années 2000, une clef d’entrée privilégiée pour étudier le médium vidéoludique. La capacité du jeu vidéo à prendre en charge la représentation d’une histoire par ses propres moyens (et non en empruntant ceux de la littérature ou du cinéma) a été tantôt affirmée (Ryan, 2003 ; Murray, 1998), tantôt contestée (Frasca, 1999 ; Juul, 2001 ; Eskelinen, 2001). Dès lors – même si les oppositions à son sujet sont aujourd’hui plus nuancées – elle demeure un objet problématique dont le traitement entraîne souvent d’importants détours théoriques. Les concepts de la narratologie « traditionnelle » (tels que celui d’un récit clos et prédéfini ou d’une narration « unidirectionnelle ») semblent a priori peu compatibles avec les impératifs d’interaction et de jouabilité qui sont au cœur de l’expérience vidéoludique. Quels outils adopter, en conséquence, pour décrire ce qui advient de la fiction lorsqu’elle est prise en charge par le jeu ? C’est à cette question que nous tâcherons de répondre en définissant les contours d’une notion souvent évoquée par la recherche, mais peu théorisée : celle d’« univers fictionnel ». Pour ce faire, nous nous nourrirons tant des avancées des games studies et des « play studies » (Triclot, 2011) que des théories de la fiction (Schaeffer, 1999) et de ses modes actuels de consommation par les amateurs (Jenkins, 2006). La distinction opérée par Amato (2005) entre les notions de cosmos, de diégèse et de ludiégèse permettra également de préciser la définition de ce qu’est un univers lorsqu’il est régi par le jeu. En effet, la narrativité propre au jeu vidéo ne semble pas répondre à la logique linéaire du récit : une grande part de l’histoire n’est généralement présente que de manière « latente » (Letourneux, 2005) dans une série d’éléments hétérogènes (le texte, l’interface, les décors, les sons, les objets…), situés à différents niveaux de l’œuvre et dont le sens narratif peut ou non être activé par le joueur (Guardiola, 2005 parle, à ce titre, de la dimension « permissive » du jeu vidéo). Pour décrire cette pluri-dimensionnalité et cette dispersion de l’histoire au sein d’« éléments de narrativisation » (Genvo, 2002), la notion de récit apparaît comme réductrice. À l’inverse, celle d’univers (définie dès lors comme un agencement d’éléments non hiérarchisés et éventuellement porteurs d’une narrativité latente) présente une forte opérationnalité, due principalement à deux de ses caractéristiques : son ouverture et sa nature modulable. Son ouverture, tout d’abord, car elle permet non seulement de prendre en compte l’ensemble des composantes de la fiction qui sont internes à l’œuvre vidéoludique, mais aussi celles qui lui sont externes (qu’il s’agisse du paratexte, des livrets des jeux, des bandes annonces,… ou encore de véritables développements narratifs autonomes, réalisés sur différents médias). Sa malléabilité, ensuite, car le concept d’univers, contrairement à celui de narration, admet l’interactivité : c’est le joueur qui actualise le récit (il participe à son énonciation) et qui, par la continuité de sa présence, organise les « éléments de narrativisation » en une configuration cohérente. En outre, concevoir la fiction comme un agencement de diverses composantes permet d’envisager les constantes évolutions que lui font subir les communautés d’amateurs : ceux-ci, en confrontant leurs représentations, développent par exemple des modèles collectifs « non officiels » (les « fanons » ; voir Hellekson et Busse, 2006) qui ont un impact certain sur la vie des fictions. L’univers fictionnel constitue, en somme, un outil théorique porteur qui rend possible la description des points de passage entre jeu et fiction et l’évaluation des contraintes que l’un exerce sur l’autre. Toutefois, bien qu’il ait initialement été élaboré pour correspondre au domaine spécifique du jeu vidéo, le concept semble déborder de ces premiers questionnements et s’adapter, plus généralement, à l’étude des modes actuels de production et de consommation de la fiction. En effet, son ouverture invite, d’une part, à élargir la conception traditionnelle de la narration et à l’envisager comme un ensemble transmédiatique. D’autre part, sa nature d’agencement n’est pas sans rappeler les théories d’Azuma (2008) selon lesquelles les fictions postmodernes ne sont plus considérées comme des unités finies et fermées, mais comme des agencements qui puisent dans un fonds commun, une « base de données » perpétuellement renouvelée. Chaque élément investi par la fiction intègre ce fonds commun et devient alors susceptible de connaître des continuations, des réappropriations, des réagencements. Les histoires conçues sur ce mode ne sont pas lues, mais vécues et explorées : la lecture devient une expérience et une expérimentation. [less ▲]

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See detailThe potentiality of PDMAEMA-based polycation for cardiovascular applications
Flebus, Luca ULg; Lombart, François ULg; Martinez, Lucia et al

Conference (2014, June 18)

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See detailAssessment of Solvent Degradation within a Global Process Model of Post-Combustion CO2 Capture
Léonard, Grégoire ULg; Heyen, Georges ULg; Toye, Dominique ULg

Conference (2014, June 17)

Solvent degradation may be a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. However, its influence on the ... [more ▼]

Solvent degradation may be a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. However, its influence on the process operations has rarely been studied. In the present work, a kinetics model describing solvent oxidative and thermal degradation has been developed based on own experimental results for the benchmark solvent, i.e. 30 wt% monoethanolamine (MEA) in water. This model has been included into a global Aspen Plus model of the CO2 capture process. The selected process modelling approaches are described in the present work. Using the resulting simulation model, optimal operating conditions can be identified to minimize both the energy requirement and the solvent degradation in the process. This kind of process model assessing solvent degradation may contribute to the design of large-scale CO2 capture plants to consider not only the process energy penalty, but also its environmental penalty. Indeed, both aspects are relevant for the large-scale deployment of the CO2 capture technology. [less ▲]

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See detailPrior light history impacts on higher order cognitive brain function
Chellappa, Sarah Laxhmi ULg; Ly, Julien; Meyer, Christelle ULg et al

Conference (2014, June 17)

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See detailThe circadian system sets the temporal organization of basic human neuronal function
Chellappa, Sarah Laxhmi ULg; Ly, Julien; Gaggioni, Giulia et al

Conference (2014, June 16)

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See detailDétermination de la teneur en équol dans les laits commercialisés en Wallonie (Belgique)
Daems, Frédéric ULg; Jasselette, Christophe; Franckson, Delphine et al

Poster (2014, June 13)

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See detailMeasuring the body, measuring through the body
Vangeebergen, Thomas ULg

Conference (2014, June 13)

Body is a particular relevant way to tackle design processes, because of the multiplicity of status it can acquire during these processes: a source of information, a target to fit, a device to perform, a ... [more ▼]

Body is a particular relevant way to tackle design processes, because of the multiplicity of status it can acquire during these processes: a source of information, a target to fit, a device to perform, a complex technology, an apparatus for the users. A specific body is presented in this paper: the measured body. Trough racial anthropology, sport performances, demographic statistics, medical treatments, psycho-cognitive surveys, quantified self, or in many other contexts, human body is subject to a wide range of various measures. I would on my own propose some thoughts grounded on field exploration, concerning sensory analysis practices, in various laboratories. According to the symmetrical glaze STS have gave from the beginning to both human and non-humans, objects and subjects, the body is for a start itself one of the “stuffs” overlapping categories, blurring distinctions between things and persons, at the same a time a given and an object to perform. The measures of the body, and made with/through the body, highlight how it could be enacted, revealed, understood, improved by technology, especially when it requires some quantitative data. But it allows us also to grasp how the body is viewed simultaneously as a technological device and as the data origin, to intervene during complex practices (e.g. standardization, lab experiments, and marketing surveys). One of the numerous outcomes of such research could be the role of these bodily measurements in the definition of the actors, as well individuals than collectives. By the way it takes on a share on the network tying body to numerical data and to materiality-other-than-human, to measure the body/ through the body seems to afford socio-materiality in a particularly productive manner. Many scholars have inquired about numbers, how they could bring objectivity, how they produce confidence and security, and how finally they participate to black-box the measures themselves. Here, the aim is to understand the specificity of the body as measurement issue, being the interface of the-objects-to-be-measured and the instrument-of-measure. [less ▲]

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See detailThe Discretionary Use of Strasbourg Jurisprudence by the International Criminal Court
Deprez, Christophe ULg

Conference (2014, June 13)

Although the case law of the European Court of Human Rights ("ECtHR") has had and still shows critical influence on the development of the practice of the International Criminal Court ("ICC"), it remains ... [more ▼]

Although the case law of the European Court of Human Rights ("ECtHR") has had and still shows critical influence on the development of the practice of the International Criminal Court ("ICC"), it remains unclear what the authority of such external jurisprudence is vis-à-vis the international criminal judge. While it is virtually undisputed that human rights law, in general terms, is applicable to proceedings before the ICC, many scholars tend to adopt a much nuanced approach to the authority of human rights case law in particular. This paper aims to shed further light on the issue by addressing the question whether ICC judges have used Strasbourg jurisprudence in a consistent manner, in particular as regards the authority which they decided to vest the latter with. It demonstrates that ICC Chambers have relied on European human rights practice, alternatively, as a mere source of inspiration, as binding interpretation, as a corpus having ambivalent authority, or as a source whose legal value it simply left unspecified. This leads us to conclude that, on the whole, the ICC has been mostly inconsistent regarding the value of ECtHR case law in the context of international criminal proceedings. Such inconsistency, we argue, amounts to a discretionary use of Strasbourg jurisprudence that further reinforces the Court's paradoxical position as the ultimate authority for defining the boundaries of its own human rights constraint. [less ▲]

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See detailInternet : support, médium ou épimédium ?
Barnabé, Fanny ULg; Dozo, Björn-Olav ULg

Conference (2014, June 11)

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See detailExperimental tests and numerical modelling on eight slender steel columns under increasing temperatures
Franssen, Jean-Marc ULg; Zhao, Bin; Gernay, Thomas ULg

in Li, G.Q.; Jiang, S.C.; Chen, Suwen (Eds.) et al Progress on Safety of Structures in Fire (2014, June 11)

In order to fill the lack of knowledge about slender elements behavior at elevated temperatures,, a European research project called FIDESC4 has been funded by the RFCS. This project involves experimental ... [more ▼]

In order to fill the lack of knowledge about slender elements behavior at elevated temperatures,, a European research project called FIDESC4 has been funded by the RFCS. This project involves experimental testing, parametric numerical analyses and development of simple design rules. The present paper reports the characteristics and the results of the FIDESC4 experimental test campaign performed at the University of Liege on slender steel columns at elevated temperatures. A total of eight columns have been tested, all of them with I shape section. Six columns were made of welded sections (some prismatic and some tapered members) and two columns were with hot rolled sections. The nominal length of the columns was 3 meters with the whole length being heated. The strength of the material (webs and flanges) was measured on sample before the tests. The order of magnitude of the initial geometrical imperfections was recorded. The columns were not restrained against longitudinal thermal elongation. The supports at the ends were cylindrical thus inducing a restrain against rotation in one plane while allowing rotation in the other plane. The allowed direction of rotation was chosen in each test to induce buckling around the strong or the weak axis. The load was applied at ambient temperature and maintained for a period of 15 minutes after which the temperature was increased under constant load. The load was applied concentrically on some tests and with an eccentricity in other tests. The load eccentricity was either applied at both ends, leading to constant bending moment distribution along the length, or at one end only, leading to a triangular bending moment distribution. Heating was applied by electrical resistances enclosed in ceramic pads. The columns and the ceramic pads were wrapped in ceramic wool insulating material. This technique was preferred to gas heating in a standard test furnace because it allows applying a slower and better controlled heating rate and thus obtaining a more uniform temperature distribution in the member. It is also easier to measured lateral displacements of the column. Preliminary blank tests were performed on unloaded specimen in order to determine the heating range to be used later on the loaded columns. The paper will also report on a modification of the heating technique that was applied and improved significantly the uniformity in the temperature distribution. Numerical simulations were performed before the tests using shell elements of the software SAFIR and assumed values of the material properties in order to predict the failure modes. It was essentially crucial to determine whether lateral supports at intermediate levels should be provided in order to ensure failure in the desired direction. Experience showed that the failure modes developed as predicted by the numerical simulations. Besides a thorough description of the experiments, the paper will also present the obtained results in terms of failure mode, ultimate temperature and evolution of longitudinal and transverse displacement. Some information will also be given about the level of detail that has to be used in the numerical model in order to get accurate results at a reasonable price. [less ▲]

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See detailLes remèdes d'origine égyptienne utilisés dans la médecine vétérinaire antique
Marganne, Marie-Hélène ULg

Conference (2014, June 10)

Recherche systématique des ingrédients d'origine égyptienne attestés dans les recettes des écrits vétérinaires grecs et latins, et comparaison de leur utilisation à celle de la médecine humaine, avec ... [more ▼]

Recherche systématique des ingrédients d'origine égyptienne attestés dans les recettes des écrits vétérinaires grecs et latins, et comparaison de leur utilisation à celle de la médecine humaine, avec évaluation de leur accessibilité et leur coût. [less ▲]

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See detailFe and Mg Isotope Fractionation in Olivine from the NWA 1068 Shergottite
Collinet, Max ULg; Charlier, Bernard ULg; Namur, Olivier et al

Conference (2014, June 09)

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See detailHigher Symmetries of the conformal Laplacian
Radoux, Fabian ULg

Conference (2014, June 09)

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See detailEffects of tillage practices and crop residue exportation on earthworm communities and soil physico-­chemical properties in silt loam arable soil (Belgium)
Lemtiri, Aboulkacem ULg; Colinet, Gilles ULg; Alabi, Taofic ULg et al

Poster (2014, June 08)

Earthworms are known to play integral roles in soils, and are often referred to as vital soil and ecosystem engineers due to their capacity to influence a wide range of chemical, physical, and biological ... [more ▼]

Earthworms are known to play integral roles in soils, and are often referred to as vital soil and ecosystem engineers due to their capacity to influence a wide range of chemical, physical, and biological properties of soil environments. Therefore, it is important to understand how earthworm communities are impacted by tillage systems and crop management practices. In the present study, earthworm and soil samples were collected from wheat cultivated fields in Gembloux, Belgium under the following four experimental treatments: (1) conventional tillage with crop residues left in the soil (CT/IN); (2) conventional tillage with crop residues removed from the field (CT/OUT); (3) reduced tillage with crop residues left in the soil (RT/IN); and (4) reduced tillage with crop residues removed from the field (RT/OUT). The different tillage systems were applied for four consecutive years prior to the initiation of the current study. Results indicated soil compaction was significantly higher in RT compared with CT up to a depth of 6–49 cm. Significant differences were not detected between residue incorporation depth systems, where results showed mean earthworm abundance was respectively 182.25 and 180 individuals.m-2 in CT and RT. Mean earthworm biomass was similarly not significantly different between CT and RT, where results were respectively 48.52 and 57.27 g.m-2. However, a significant difference was observed between IN and OUT treatments, suggesting the exportation of wheat residues will limit earthworm abundance and biomass in CT and RT plots. Data showed high representation of the endogeic earthworm ecological category, notably N. c. caliginosus regardless of treatment. Despite tillage system and exportation of crop residues, N. c. caliginosus, L. terrestris, and A. r. rosea exhibited high abundance, indicating tolerance to soil environmental conditions. For each depth, measures of soil physico-chemical properties showed significant differences among treatments. Furthermore, soil chemical property attributes were significantly higher in the first soil centimetres compared to lower soil layers. These results were attributable to earthworm activity and wheat residues, suggesting earthworms contributed to nutrient dynamics, particularly at increased soil depths. Overall, the results emphasise the influence of exportation of crop residues on earthworm community and also, the important influence of earthworm activity on soil physico-chemical properties change, processes which are closely linked. [less ▲]

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See detailFast Ambient Pressure Thermal cycling of space solar arrays samples under equivalent AM0 illumination conditions
Guiot, Marc ULg; Fernandez Lisbona, Emilio; Witteveen, Bob et al

Conference (2014, June 08)

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See detailComparison between wind speed observed at 100m height and wind speeds simulated by the WRF and MAR models
Doutreloup, Sébastien ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2014, June 06)

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the ... [more ▼]

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the WRF regional model (v.3.4.) forced by ERA-Interim model. Our analysis shows that wind speeds at 100m height simulated by WRF are systematically overestimated compared to wind speeds extracted from wind productions of two wind farms. In order to identify this problem, four comparisons were performed in this contribution. Firstly, we compare WRF model with reanalysis based forcing model. Secondly, we compare two WRF simulations, where one of them has a more precise spatial resolution. Thirdly, we smooth WRF outputs in time (6-hr running mean) in order to study the accuracy of the 30-min variability generated by WRF model. Finally, we comp compare the WRF model with the MAR (v3.3.) regional model using the same forcing at its lateral boundaries. This last one seems to suggest that the MAR model better simulates wind speeds at 10m and at 100m than WRF model and then that wind speed underestimation by WRF is well linked to the WRF physics itself. [less ▲]

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See detailOn-the-fly domain adaptation of binary classifiers
Pierard, Sébastien ULg; Marcos Alvarez, Alejandro ULg; Lejeune, Antoine ULg et al

in 23rd Belgian-Dutch Conference on Machine Learning (BENELEARN) (2014, June 06)

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to ... [more ▼]

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to negative and positive classes are supposed to be mixtures of the source distributions. Moreover, the mixture weights and the priors are only available at runtime. We present a theoretical solution to this problem, and demonstrate the effectiveness of the proposed approach on a real computer vision application. Our theoretical solution is applicable to any classifier approximating Bayes' classifier. [less ▲]

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See detail[18F]UCB-H AS A NEW PET RADIOTRACER FOR SYNAPTIC VESICLE PROTEIN 2A
Bahri, Mohamed Ali ULg; Bastin, Christine ULg; Aerts, Joël ULg et al

Poster (2014, June 06)

Synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown ... [more ▼]

Synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, for example, by the fact that it is a binding site and the primary mechanism of levetiracetam. Levetiracetam is an antiepileptic drug which has recently been suggested to reduce synaptic deficits in a mouse model for Alzheimer’s disease and to improve cognition in patients with amnestic mild cognitive impairment. We here aimed to investigate the cerebral distribution of [18F]UCB-H, a fluorine-18 radiolabelled PET imaging tracer, which has a high affinity with the SV2A. [18F]UCB-H was radiosynthesized under GMP conditions. Dynamic PET data of the head of four healthy volunteers were acquired over 100 minutes after injection of 170.4 ± 24.9 MBq of [18F]UCB-H. The arterial input function was obtained by blood sampling during the dynamic PET acquisition. The analysis of the blood data reveled a consistent amount of [18F]UCB-H in whole blood and plasma which indicates a very low degree of binding of the tracer to the red blood cells. The unchanged fraction of [18F]UCB-H in plasma showed a bi-exponential behavioral decrease with a starting fraction of 92% of the injected amount of the tracer, measured at 3 min post injection. This fraction decreased to about 50% at 10 min post injection. The [18F]UCB-H PET data showed a high and rapid uptake in the grey matter structures, matching the known ubiquitous distribution of the SV2A in the brain. The kinetics of the tracer in the brain was characterized by an initial high uptake phase followed by rapid washout allowing the standard compartmental modeling (1-tissue compartment, 2-tissue compartment, and Logan graphical analysis). The three models gave consistent results. The two-tissue compartment model fitted the experimental data best and provided a total distribution volume of the [18F]UCB-H in the brain greater than 7 mL/cm3 and a specific distribution volume around 3 mL/cm3. Our results suggest that [18F]UCB-H is a good candidate as radiotracer for brain SV2A proteins and could be used for human studies. In the future, SV2A modifications might be assessed in neurological pathologies such as Alzheimer’s disease. [less ▲]

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See detailLe sort des travailleurs d’une entreprise en réorganisation judiciaire
Kéfer, Fabienne ULg; Gailliet, Guillaume ULg

in Clesse, Jacques (Ed.) Questions choisies de droit social. Hommage à Michel Dumont (2014, June 06)

Le droit de l’entreprise en difficulté entretient avec le droit du travail des liens tendus. La préservation du potentiel économique de l’entreprise s’affronte aux dispositions visant à éviter la ... [more ▼]

Le droit de l’entreprise en difficulté entretient avec le droit du travail des liens tendus. La préservation du potentiel économique de l’entreprise s’affronte aux dispositions visant à éviter la dégradation de la situation des travailleurs. Le complexe normatif étudié reflète le point actuel du rapport de force entre le monde économique et les syndicats. Les salariés sont, en définitive, amenés à faire une grande partie du sacrifice nécessaire pour atteindre l’objectif économique recherché. Ce constat est perceptible dans l’hypothèse d’une réorganisation par accord collectif et dans celle du transfert sous autorité de justice, qui témoignent des rapports complexes entre les intérêts économiques et sociaux. La conciliation de ces intérêts divergents s’effectue sous la surveillance du juge. [less ▲]

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See detailMuti-scale methods with strain-softening: damage-enhanced MFH for composite materials and computational homogenization for cellular materials with micro-buckling
Wu, Ling ULg; Nguyen, Van Dung ULg; Adam, Laurent et al

Conference (2014, June 06)

In this work, multi-scale methods with strain softening are developed in the contexts of damage modeling for composite laminates and of buckling analyses in cellular materials. First, an anisotropic ... [more ▼]

In this work, multi-scale methods with strain softening are developed in the contexts of damage modeling for composite laminates and of buckling analyses in cellular materials. First, an anisotropic gradient–enhanced continuum damage model is embedded in a mean–field homogenization (MFH) process for elasto-plastic composites. The homogenization procedure is based on the newly developed incremental secant mean-field homogenization formulation, for which the residual stress and strain states reached in the phases upon a fictitious elastic unloading are considered as starting point to apply the secant method. The mean stress fields in the phases are then computed using isotropic secant tensors, which are naturally used to define the Linear Comparison–Composite The resulting multi– scale model is then applied to study the damage process at the meso–scale of laminates, and in particular the damaging of plies in a composite stack. By using the gradient–enhanced continuum damage model, the problem of losing uniqueness upon strain softening is avoided. Second, an efficient multi–scale finite element framework capturing the buckling instabilities in cellular materials is developed. As a classical multi–scale computational homogenization scheme loses accuracy with the apparition of the macroscopic localizations resulting from the micro–buckling, the second order multi–scale computational homogenization scheme is considered. This second–order computational framework is enhanced with the following novelties so that it can be used for cellular materials. At the microscopic scale, the periodic boundary condition is used because of its efficiency. As the meshes generated from cellular materials exhibit a large void part on the boundaries and are not conforming in general, the classical enforcement based on the matching nodes cannot be applied. A new method based on the polynomial interpolation2 without the requirement of the matching mesh condition on opposite boundaries of the representative volume element (RVE) is developed. Next, in order to solve the underlying macroscopic Mindlin strain gradient continuum of this second–order scheme by the displacement–based finite element framework, the treatment of high order terms is based on the discontinuous Galerkin (DG) method to weakly impose the C1-continuity. Finally, as the instability phenomena are considered at both scales of the cellular materials, the path following technique is adopted to solve both the macroscopic and microscopic problems. [less ▲]

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See detailA PREFERENTIAL FOLDED CONFORMATION OF SOME BIS-(8-ISOPROPYL-ISOQUINOLINIUM) DERIVATIVES EXPLAINS STEREOSELECTIVE REDUCTION BY SODIUM BOROHYDRIDE
Dilly, Sébastien ULg; Badarau, Eduard; Dufour, Fabien et al

Poster (2014, June 05)

Small conductance Ca2+-activated K+ (SK) channels play a role in modulating the firing rate and the firing pattern of neurons [Waroux, Eur J Neurosci, 2005, 22, 3111]. A blockade of these targets could be ... [more ▼]

Small conductance Ca2+-activated K+ (SK) channels play a role in modulating the firing rate and the firing pattern of neurons [Waroux, Eur J Neurosci, 2005, 22, 3111]. A blockade of these targets could be useful for the treatment of cognitive dysfunction, neuronal hyperexcitability or dopamine related disorders [Liégeois, Curr Med Chem, 2003, 10, 625]. At the peripheral level, the inhibition of these channels was demonstrated to prevent and terminate atrial fibrillation [Diness, Circ Arrhythm Electrophysiol, 2010, 3, 380]. Moreover, SK channels might represent potential targets for a new class of anticancer agents due to their involvement in breast cancer cell migration [Potier, Mol Cancer Ther, 2006, 5, 2946]. So far, available blockers are not suitable CNS pharmacological tools being either peptides or small molecules with permanent positive charges [Liégeois, Curr Med Chem, 2003, 10, 625; Graulich, J Med Chem, 2007, 50, 5070; Badarau, Bioorg Med Chem Lett, 2011, 21, 6756]. Therefore, symmetrical bis-isoquinolinium compounds have subsequently been transformed to 1,2,3,4-tetrahydroisoquinoline analogues by using sodium borohydride leading to a diastereoisomeric mixture (figure 1) in order to obtain potential CNS-penetrating agents [Graulich, Bioorg Med Chem Lett, 2008, 18, 3440; Neny, Proceedings of the 12th International Conference on In Vivo Methods, Vancouver, Canada, 2008, 267; Koulchitsky, Acta Physiologica, 2009, 195, 670]. Resolution of these mixtures and characterization of the corresponding stereoisomers [Wouters, Eur J Med Chem, 2010, 45, 3240] are necessary before further biological evaluation. In a series of 8- isopropyl analogues, chiral resolution failed for the analogues with propyl and m-xylyl linkers since two and one peaks, respectively, were detected [Nistor, J Pharm Biomed Anal, 2013, 74, 273]. Could these results be explained by an ineffective resolution or would another phenomenon be involved? Further analysis using chiral chromatography, mass spectroscopy and circular dichroism of a sample of the propyl analogue revealed that it is a racemic mixture. X-ray cristallography and conformational analysis indicated a folded conformation of the propyl and m-xylyl analogues (figure 2) responsible for a stereoselective attack of the borohydride reagent during the reduction step. Additional 1H-NMR investigations support structural features detected by theoretical analysis. [less ▲]

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See detailMALDI Mass Spectrometry Imaging: a new tool to decipher the antibiome of Bacillus amyloliquefaciens
Debois, Delphine ULg; Jourdan, Emmanuel; Cawoy, Hélène et al

Conference (2014, June 05)

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known ... [more ▼]

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known to exert different actions on the wellness of the producing strain such as fungitoxicity (iturin, fengycin) or motility, root colonization and immune stimulating agent (surfactin). Nevertheless, few is reported about the actual antibiome secreted in situ by Bacillus cells during confrontation with phytopathogens or plant root colonization. We developed a method mimicking the conditions prevailing in the rhizosphere and, taking advantage of the versatility of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging, we were able to localize and identify antibiotics produced in situ by bacterial cells. First, we applied this new methodology to bioassays in which Bacillus amyloliquefaciens 98S were grown together with Fusarium oxysporum, with the aim of deciphering the role of the different LP families during the phytopathogen growth inhibition. Our results showed that the three LP families were readily produced in different proportions. Especially, images of surfactins, iturins and fengycins demonstrated that iturins are the antibiotic family actually involved in the antagonism against Fusarium oxysporum. In a second approach, we used a “in planta” model in which Bacillus amyloliquefaciens S499 was simultaneously grown with Tomato and Arabidopsis thaliana roots. Imaging results, obtained during a time course analysis, showed that surfactin is always the major lipopeptide detected. In further experiments involving a refined time-window, we observed that surfactin is actually produced as soon as 24h post inoculation. These results were the starting point of a wider study showing that the early accumulation of surfactin is a complex phenomenon involving, among other mechanisms, cell-well components recognition by bacteria, and that this interaction is a win-win association for both plant and bacterial cells. [less ▲]

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See detailLa charge de confesseur princier au XVIIème siècle, une définition controversée
Pirlet, Pierre-François ULg

Conference (2014, June 05)

Si la mission d'un confesseur au début du XVIIème siècle est strictement définie par les textes canoniques du catholicisme comme celle d'un administrateur de sacrement, la définition des tâches revenant ... [more ▼]

Si la mission d'un confesseur au début du XVIIème siècle est strictement définie par les textes canoniques du catholicisme comme celle d'un administrateur de sacrement, la définition des tâches revenant au confesseur du Prince est étonnamment lâche. Du premier, on attendait qu'il jugeât les actes de son pénitent, propose une consolation – sous la forme d'exercices expiatoires – destinés à le réconcilier avec Dieu, et offre une direction spirituelle visant à prévenir les rechutes dans le péché. Mais confesser le Prince contraignait le religieux qui s’y attelait à un exercice bien plus complexe. Il lui revenait de juger et d'apporter une direction de conscience aux deux personnes du roi : l'humaine et l'institutionnelle. En effet, il eût été impossible de distinguer formellement l'âme du souverain de celle du mortel. De même, il échoyait au confesseur de conseiller son pénitent quant à l'aspect moral de ses décisions, que celles-ci n'impliquèrent que sa personne, ou au contraire l'ensemble des territoires et des sujets sous sa conduite. De cette difficulté naquit une controverse quant à l'implication nécessaire et raisonnable du confesseur princier dans les affaires temporelles : la papauté, les rois d'Espagne, les ecclésiastiques de cour madrilènes, les gouverneurs-généraux des Pays-Bas et les supérieurs des ordres religieux dont étaient issus les confesseurs – et particulièrement la Compagnie de Jésus – proposèrent tous une définition différente – et controversée – des prérogatives de ce religieux au cœur du pouvoir. En prenant appui sur la situation des confesseurs de la cour de Bruxelles durant la grande première moitié du XVIIème siècle, nous tâcherons au travers de cette communication de proposer un aperçu global des différentes définitions de la confession princière telles que défendues par les contemporains. Notre exposé proposera en outre un rapide regard sur les deux approches utilisées par les historiens pour reconstituer les différentes définitions de la charge : à la patiente collecte et à l'analyse des traces laissées dans les sources par l'activité au quotidien des confesseurs (approche bottom-up) se confronte une méthode cherchant une définition d'époque des prérogatives de ces religieux faisant autorité (approche top-down). Nous constaterons que ces deux approches, qui ne s'opposent pas, s’accommodent néanmoins difficilement l'une à l'autre, créant ainsi une controverse non plus dans l'objet, mais dans la méthode. [less ▲]

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See detailApproche lexicométrique des controverses climatiques
Scotto d'Apollonia, Lionel; Luxardo, Giancarlo; Piet, Grégory ULg

Poster (2014, June 05)

D’un point de vue historique, les controverses climatiques prennent racine à la fin du XIXe siècle et se sont déployées tout au long du XXe siècle. Elles prennent toutefois une tournure plus politique, en ... [more ▼]

D’un point de vue historique, les controverses climatiques prennent racine à la fin du XIXe siècle et se sont déployées tout au long du XXe siècle. Elles prennent toutefois une tournure plus politique, en ce début de XXIe siècle, en ce sens que le débat climatique « se priorise » dans les agendas politiques des Etats européens, de manière générale. Si les études sur les controverses climatiques tendent, certes, à se développer de plus en plus actuellement, l’approche linguistique demeure peu investie par rapport au potentiel analytique qu’elle pourrait apporter à la recherche sur le sujet. L’une des rares études lexicométriques concernant le climat est celle réalisée par Lamria Chetouani dont le corpus de textes s’étend de 1989 à 1990. Il faut aussi prendre en compte les travaux de Francis Chateauraynaud, qui a entrepris une démarche destinée au traitement des controverses s'appuyant sur un ensemble de techniques : la socio-informatique. Inscrit dans un cadre d’analyse socioépistémique des controverses socioscientifiques et en se basant sur un corpus de textes choisis autour de la période 2009 - 2010, notre article propose donc d'associer une analyse socio-informatique des controverses climatiques avec une utilisation d'outils lexicométriques. En nous concentrant sur le traitement discursif de quelques notions-clés, notamment l'incertitude et le risque, nous cherchons à croiser les résultats fournis par la lexicométrie (logiciel Lexico) avec ceux fournis par la socio-informatique (logiciel Prospero). En conclusion, nous ouvrons un espace de discussion sur les modes opératoires permettant d'articuler les deux approches. [less ▲]

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See detailLes médiateurs scolaires en action : des discours aux pratiques
Dethier, Baptiste ULg

Conference (2014, June 05)

En 1993, dans un contexte marqué les questions d’insécurité, de violence scolaire, de crise de confiance envers les institutions ou encore de décrochage scolaire, 28 médiateurs sont engagés dans autant ... [more ▼]

En 1993, dans un contexte marqué les questions d’insécurité, de violence scolaire, de crise de confiance envers les institutions ou encore de décrochage scolaire, 28 médiateurs sont engagés dans autant d’établissements scolaires aux publics défavorisés de la région bruxelloise. Ce projet pilote, voyant le jour sous la houlette du Ministère de l’enseignement, ne sera institutionnalisé qu’en 1998 dans un décret créant le Service de Médiation Scolaire, divisé en deux entités : 56 médiateurs internes à Bruxelles et 30 médiateurs externes (répartis par zones couvrant plusieurs établissements) en Wallonie. Par ailleurs, d’autres niveaux de pouvoir (communes, diocèses, écoles) créaient également, localement, leurs propres fonctions de médiateur scolaire. Actuellement, on en dénombre environ 120 en Belgique francophone. Ce nouvel acteur, bien que peu étudié, incarnerait un nouveau mode de régulation sociale (Bonafé-Schmitt, 1996) remettant en question les équilibres historiques du système scolaire (Verhoeven, 1997). En effet, il se présente comme un tiers neutre et indépendant de l’établissement, permettant ainsi la création d’un espace où peuvent se résoudre différents problèmes concernant les personnes demandeuses, qu’elles soient élèves, membres du personnel scolaire ou encore parents. Dans un premier temps, notre attention se porte sur l’ensemble des acteurs portant le nom de médiateurs scolaires (Kuty et al., 2012). Au sein d’un cadre légal ne définissant que vaguement leur fonction, ces derniers sont néanmoins globalement chargés de prévenir la violence et le décrochage scolaires et de favoriser, conserver ou rétablir le climat de confiance entre élèves, écoles et familles. À partir de là, ils ont progressivement construit leurs propres pratiques et leur identité, cherchant par là à trouver et à consolider leur place au sein d’un milieu scolaire déjà marqué par la présence de multiples acteurs. Dans un second temps, des études de cas approfondies dans six établissements d’enseignement secondaire permettent de constater que les médiateurs ne disposaient pas du monopole de la médiation (Dubois et Dethier, 2013), concept polysémique auquel de nombreux acteurs se réfèrent pour qualifier certains aspects de leur travail quotidien. En outre, le recours à la médiation ou aux médiateurs ne se révèle être qu’une solution parmi d’autres pour faire face aux différents problèmes rencontrés par les acteurs : violence, décrochage, absentéisme, échec scolaire, conflits, problèmes socio-économiques… Ces constats exigent une étude empirique approfondie du travail concret réalisé par les médiateurs scolaires, une étude attentive à leurs discours mais aussi à l’observation de leurs pratiques et interactions directes avec les différents acteurs scolaires. Les résultats de cette étude font l’objet de cette communication. Cette contribution se base sur un corpus composé de onze entretiens individuels, trois focus groups et trois périodes d’observation non participante auprès de médiateurs belges francophones membres d’un même service. Ces derniers revendiquent une posture de tiers neutre et indépendant dans l’école, ainsi que des principes basés sur le non-jugement, la confidentialité, l’accueil inconditionnel de la demande ou encore la non-expertise. Il s’agira par conséquent de rendre compte de la manière dont ces médiateurs traduisent leurs discours en pratiques au quotidien. [less ▲]

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See detailBiorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes
Tarayre, Cédric ULg; Fischer, Christophe ULg; De Clercq, Lies et al

Conference (2014, June 05)

At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs ... [more ▼]

At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs). Currently, sewage sludge, for example is usually used as a fertilizer in agriculture, in energy production or in the field of construction. Ashes originating from sludge incineration contain heavy metals and minerals in large quantities. Manure is mainly used in agriculture, although considerable amounts of nutrients are lost and cause pollution. Digestate is also used in agriculture, but other alternatives have been proposed, such as the energetic valorization. Better valorization of these wastes in agriculture (or other sectors) is however largely constrained by a multitude of legal requirements. An important problematic point is the concentration in MTEs that is found in those wastes. Consequently, recovery of nutrients and MTEsmay be a key solution for optimal valorization of wastes. Many unit operations used in the field of chemical and biochemical engineering (mechanical operations on fluids, solids, mass and heat transfers, chemical reactions, etc.) could be used in order to achieve an efficient recovery yield of nutrients and trace elements. The aim of the BioRefine Project is to make an inventory of all recovery techniques of nutrients and MTEs in five countries: Belgium, France, Germany, United Kingdom and The Netherlands. Pilot plants will also be tested to assess the efficiency of new treatment techniques after which the most efficient processes will be chosen to be applied on a larger scale. In addition, the collected data will be used to propose exploitation scenarios taking into account legal constraints and optimized logistics.This work is supported through an INTERREG IVB NWE programme(ref. 320J-BIOREFINE). [less ▲]

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See detailLa psychopathologie à la lumière des histoires de vie : Etude de la fonction narrative d’adolescents obèses et dépressifs.
Jadin, Aurore ULg; Gauthier, Jean-Marie ULg; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-Actes des 12èmes journées internationales d'analyse statistique de données textuelles (2014, June 05)

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these ... [more ▼]

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these youngs (High Authority of Health, 2011; Nietsen and Bruwier, 2007). The literature mentions depression as a pathology associated with obesity. Some researchers consider obesity as a cause of depressive symptoms while others researchers see depression like a risk factor for excessive weight gain (Blaine, 2008). Depression in adolescence has been the subject of epidemiological studies for some years. In adolescents, the prevalence rates vary from 5 to 7 % for major depressive episode (MDE) with a prevalence of 2 girls for one boy (Alvin and Marcelli, 2005). The specific symptoms of depressed mood are present in 30-40 % of schooled adolescents (Boulard et al., 2012). During adolescence, the individual acquires the ability to link the various elements of one’s life and build a coherent life story. The adolescent will write one’s story in a personal context. According to Habermas et al. (2008), both the form and the content of life stories show how the individual integrates the lived experiences in a coherent whole. Based on the statistical analysis of textual data, we compared the life stories of 28 obese adolescents, depressed schooled adolescents, depressed hospitalized adolescents and control ones. The first results show specific structures and particular contents depending on these groups. The use of pronouns, temporal markers and the reported events differ by groups. Beyond clinical results, this research also highlights the interest of statistical analysis of textual data (ADT) to improve the understanding of adolescent’s psychopathology. [less ▲]

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See detailExploration du récit de vie d’adolescents
Poudat, Céline; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-actes des 12èmes journées d'analyse statistique de données textuelles (2014, June 05)

The present paper follows on from the research we presented in previous JADT (Boulard, Poudat, Gauthier 2012). We still focus on the development of narrative competence (Habermas et Bluck 2000) in ... [more ▼]

The present paper follows on from the research we presented in previous JADT (Boulard, Poudat, Gauthier 2012). We still focus on the development of narrative competence (Habermas et Bluck 2000) in children and adolescents. Although children develop narrative skills, life narratives only emerge in adolescence. On the basis of a corpus made of spontaneous oral speech, we had empirically demonstrated that pre-adolescents aged of 12 had developed stabilized narrative skills enabling them to produce life narratives. Here, we propose a first exploration of the overall structure of adolescent life stories, thanks to a corpus of 268 oral self narratives completed with a questionnaire. [less ▲]

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See detailDesign and synthesis of high-affinity ligands of AMPA receptors and study of their Fluorine-18 radiolabeling
Deverdenne, François ULg; Goffin, Eric ULg; Plenevaux, Alain ULg et al

Poster (2014, June 05)

The AMPA subtype of glutamatergic receptors is the main actor in the excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the ... [more ▼]

The AMPA subtype of glutamatergic receptors is the main actor in the excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the maintenance of the long-term potentiation, a phenomenon closely linked to cognitive and memorization processes. Based on experimental data collected in recent years, the use of AMPA potentiators seems to be an interesting approach in the treatment of cognitive deficits (e.g. Alzheimer disease), schizophrenia or depression. Such AMPA signal potentiation could be mediated by positive allosteric modulators (PAMs) of the AMPA receptors, a class of compounds able to produce a fine signal tuning in the presence of the endogenous ligand in the synapse, providing less toxicity than direct agonists. With this approach, the laboratory of Medicinal Chemistry of Liège university developed many series of AMPA potentiators , among which 1,2,4-benzothiadiazine 1,1-dioxides (BTDs). In order to better understand the in vivo mapping of AMPA receptors and its evolution in neurological diseases, the present work aims at developing the design and the synthesis of BTDs positive allosteric modulators radiolabeled with a fluorine-18 atom. Based on previously synthesized series in this field, we investigate the synthesis of a new class of high-affinity AMPA potentiators characterized by the presence of a fluorine atom at selected positions on the structure of the AMPA potentiators. Thanks to in vitro pharmacological evaluations, we will further determine the best candidates for their fluorine-18 radiolabeling. [less ▲]

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