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See detailUrban Development as a Continuum: A Multinomial Logistic Regression Approach
El Saeid Mustafa, Ahmed Mohamed ULg; Cools, Mario ULg; Saadi, Ismaïl ULg et al

in Gervasi, Osvaldo; Murgante, Beniamino; Misra, Sanjay (Eds.) et al Computational Science and Its Applications – ICCSA 2015, Part III (2015)

Urban development is a complex process influenced by a number of driving forces, including spatial planning, topography and urban economics. Identifying these drivers is crucial for the regulation of ... [more ▼]

Urban development is a complex process influenced by a number of driving forces, including spatial planning, topography and urban economics. Identifying these drivers is crucial for the regulation of urban development and the calibration of predictive models. Existing land-use models generally consider urban development as a binary process, through the identification of built versus non-built areas. This study considers urban development as a continuum, characterized by different level of densities, which can be related to different driving forces. A multinomial logistic regression model was employed to investigate the effects of drivers on different urban densities during the past decade in Wallonia, Belgium. Sixteen drivers were selected from sets of driving forces including accessibility, geophysical features, policies and socioeconomic factors. It appears that urban development in Wallonia is remarkably influenced by land-use policies and accessibility. Most importantly, our results highlight that the impact of different drivers varies along with urban density. [less ▲]

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See detailEngager le littéraire : le cas Sartre/Fanon
Cormann, Grégory ULg

Conference (2015, June 20)

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See detailQui sait ce que je veux dire ? Externalisme sémantique versus phénoménologie
Leclercq, Bruno ULg

Conference (2015, June 19)

L’objectivisme sémantique de Bolzano et Frege se présente d’abord comme une critique du psychologisme des théories modernes de la signification entendue comme idée, représentation ou image mentale ... [more ▼]

L’objectivisme sémantique de Bolzano et Frege se présente d’abord comme une critique du psychologisme des théories modernes de la signification entendue comme idée, représentation ou image mentale. Quoique solidaire de cette critique, Husserl entend bien, quant à lui, montrer que les significations sont néanmoins constituées dans des actes mentaux, les « intentions de signification ». En cela, il s’oppose au platonisme autant qu’au psychologisme. Or il en va exactement de même des thèses de Wittgenstein et Quine, qui, rejetant le(s) mythe(s) de la signification, insistent sur la constitution du sens dans les pratiques linguistiques. Mais l’assimilation du sens à l’usage social dépsychologise aussi les intentions de signification (le « vouloir dire » (meinen, mean)) ainsi que la « compréhension » (le « saisir » (begreifen, grasp)). A l’heure de l’externalisme (social mais aussi indexical), y a-t-il alors encore une place pour la phénoménologie en philosophie du langage ? [less ▲]

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See detailDevelopment of a new design method for the cross-section capacity of steel hollow sections
Nseir, Joanna ULg

Doctoral thesis (2015)

The cross-sectional behaviour of steel sections can be shown to be influenced by two extreme behaviors: the resistance and the instability. These boundaries are accounted for in current standards through ... [more ▼]

The cross-sectional behaviour of steel sections can be shown to be influenced by two extreme behaviors: the resistance and the instability. These boundaries are accounted for in current standards through a classification system consisting on rules depending on the cross-section dimensions. For example, in EN 1993-1-1, classes are defined spanning from stocky sections (class 1) able to develop their full plastic capacity, to slender sections (class 4) for which the effective properties are used with the use of the effective width method (EWM). However, for cold-formed steel sections, characterized by a non-linear material law, the cross-section resistance can go beyond its plastic capacity due to strain hardening effects. Moreover, with the emergence of high strength steel (i.e. cross-sections falling into class 4) and more complex cross-section shapes, the effective width method is becoming too complicated. Many other reasons and discrepancies are making the cross-section classification too complex and inconsistent. The Overall Interaction Concept (OIC) stands as a new design approach that aims at a straightforward design check of the stability and resistance of steel cross-sections. Based on the use of a generalized relative slenderness and so-called interaction curves, it can be applied to any type of cross-section, further includes potential non-linear material behaviour and covers combined loading cases. The main aim of this thesis is to develop and propose OIC interaction curves dedicated to steel hollow sections subjected to various load cases. A test program was carried out as a part of a European project named ‘HOLLOPOC’ to investigate the cross-sectional behavior of cold-formed hot-finished and hot-rolled square, rectangular and circular sections. 57 cross-sections tests including simple and combined load cases were performed. Besides, a finite element model was developed and calibrated on the basis of the tests, and its accuracy was seen to be sufficient to subsequently undergo an extensive numerical parametric study for hot-rolled and cold-formed cross-sections, leading to over than 40 000 numerical results. Based on these computations, design proposals were made within the context of the Overall Interaction Concept, using an extension of the Ayrton-Perry approach. Finally, a validation of the proposed formulae was made through a comparison with existing approach and worked examples were presented, in order to illustrate (i) the application of the method and (ii) its benefits in comparison to application of current EC3 rules. [less ▲]

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See detailDes bandes fleuries pour la lutte biologique : état des lieux, limites et perspectives en Wallonie – Une synthèse bibliographique.
Hatt, Séverin ULg; Uyttenbroeck, Roel ULg; Bodson, Bernard ULg et al

in Entomologie Faunistique = Faunistic Entomology (2015), 68

Managing field margins takes part of the Agri-Environmental Measures supported by the European Union in Wallonia. Among possible infrastructures, wildflower strips are known to conserve a wide diversity ... [more ▼]

Managing field margins takes part of the Agri-Environmental Measures supported by the European Union in Wallonia. Among possible infrastructures, wildflower strips are known to conserve a wide diversity of insects, including natural enemies that can be mobilized to biologically control pests. However, the efficiency of pest control is not guaranteed. It depends mainly on the ability of flowers to attract natural enemies at the right time and to keep them in this environment while favoring their migration into adjacent crops. A reflection on the composition of the floral mixtures may optimize their capacity in biological control. In this context, this review paper put forward the interest of considering functional traits of flowers and presents the concept of functional diversity. Furthermore, the sown perennial wildflower strips should be maintained by regular mowing. However, mowing affects both insect and plant populations due to momentary destruction of the habitat. An appropriate management of field margins is therefore needed to optimize the pest control service provided. [less ▲]

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See detailHigh-dose oral intake of serotonin induces valvular heart disease in rabbits.
Lancellotti, Patrizio ULg; NCHIMI LONGANG, Alain ULg; Hego, Alexandre ULg et al

in International Journal of Cardiology (2015), 197

Carcinoid tumors are rare neuroendocrine malignancies, often originating from enterochromaffin cells in the gastrointestinal tract. They can secrete serotonin (5-hydroxytryptamine, 5-HT), which is largely ... [more ▼]

Carcinoid tumors are rare neuroendocrine malignancies, often originating from enterochromaffin cells in the gastrointestinal tract. They can secrete serotonin (5-hydroxytryptamine, 5-HT), which is largely inactivated by the liver. Carcinoid heart disease occurs when tumor cells metastasize to the liver, as the vasoactive substances produced are able to reach the systemic circulation via the hepatic vein, causing deposition of fibrous tissue on the endocardial surfaces of the heart. It is predominantly manifested by right-sided valvular heart disease (VHD). Scavenging enzymes in the pulmonary endothelium may explain why left-sided cardiac involvement is unusual. The severity of cardiac damage is correlated with the plasmatic levels of serotonin, but the lowspecificity of serotonin for cardiac damage suggests that serotonin may be necessary but not sufficient to induce cardiac lesions. Therefore, other factors combined with serotonin might be required to induce VHD. However, recent animal studies confirmed the development of carcinoid-like valvular deposits in rats after 3 months of daily subcutaneous/intraperitoneal serotonin injections to avoid the liver first-pass clearance.Whether oral administration of serotonin can also induce VHD is unknown. We hypothesized that long-term oral serotonin overload in rabbits can lead to VHD, mimicking serotonin-induced lesions of carcinoid heart disease. We demonstrate, for the first time that high dose long-term oral administration of serotonin can lead to VHD in rabbits. [less ▲]

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See detailScreening for Osteonecrosis in children treated for ALL : Why bother?
Geurten, Claire ULg; Hoyoux, Claire

Conference (2015, June 19)

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See detailDécouverte d'un nouveau syndrome : X-LAG (pour X-Linked Acrogigantism)
Beckers, Albert ULg

Scientific conference (2015, June 19)

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See detailModelling of the response of a slender structure to vortex shedding in the atmospheric boundary layer
Wertz, Freddy ULg

Master's dissertation (2015)

This work is about modelling vortex induced vibrations on a 100 m height generic reinforced concrete pylon with a square cross-section and a 20 height/width ratio, vibrating in its first across-wind ... [more ▼]

This work is about modelling vortex induced vibrations on a 100 m height generic reinforced concrete pylon with a square cross-section and a 20 height/width ratio, vibrating in its first across-wind bending mode at a frequency of 0.35 Hz for a critical wind speed of 14.6 m/s. An equivalent aeroelastic model made of a copper spline modelling the dynamic behaviour and a foam blocks skin modelling the external geometry and adjusting the mass is realized. Similitude laws are discussed based on their relevance in the simulation. The model is validated through experimental modal analysis and is tested in wind tunnel uniform and boundary layer winds. 3 turbulence levels and 4 incidence angles are tested. Measured amplitudes are small (around 5 cm in full scale). The influence of turbulence is qualitatively visible in experimental results. Analytical and numerical estimation procedures are also implemented and discussed: The Eurocode norm, a harmonic load model and the spectral model of Vickery and Clark. The Eurocode approach gives the most conservative estimations and is followed by estimations from the harmonic load model having the correlation length as parameter. The spectral model gives estimations of the order of magnitude of experimental measurements in the wind tunnel for a spectral bandwidth of 0.2 and a correlation length comprised between 1 and 3 times the width of the cross-section. [less ▲]

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See detailLe règlement de la procédure en cas de dessaisissement du juge d’instruction incompétent ratione loci ?
Michiels, Olivier ULg

in Revue de Jurisprudence de Liège, Mons et Bruxelles (2015), (127), 1174-1178

Lorsque la chambre du conseil ordonne le dessaisissement du juge d’instruction pour incompétence territoriale, le procureur du Roi, auquel le dossier est renvoyé ne peut se dispenser de saisir le juge ... [more ▼]

Lorsque la chambre du conseil ordonne le dessaisissement du juge d’instruction pour incompétence territoriale, le procureur du Roi, auquel le dossier est renvoyé ne peut se dispenser de saisir le juge d’instruction territorialement compétent et faire l’économie du règlement de la procédure devant les juridictions d’instruction [less ▲]

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See detailResiliency of a Community of Buildings to Fire Following Earthquake
Gernay, Thomas ULg; Elhami Khorasani, Negar; Garlock, Maria

Conference (2015, June 19)

Cascading multi-hazard events, such as fires following an earthquake, can trigger progressive collapse of structures. In cascading earthquake and fire events, buildings that may have already experienced ... [more ▼]

Cascading multi-hazard events, such as fires following an earthquake, can trigger progressive collapse of structures. In cascading earthquake and fire events, buildings that may have already experienced damage due to a primary earthquake hazard, should cope with a secondary extreme event. This work provides a methodology to evaluate the risk of fire ignitions after an earthquake and building responses in a community. The work has two components: In the first part, a model is developed for predicting the probability of ignition in a building due to an earthquake. This probabilistic model relies on the data from seven significant earthquakes that took place in the U.S. between 1983 and 2014. The main parameters influencing the probability of ignition are found to be the peak ground acceleration, the type of building material, and the main features of the environment in which the buildings are located (i.e. the total square footage and the population density). In the second part of this work, fragility curves are developed for performance of structures under fire, to quantify the probability of exceeding a damage state given a fire scenario. The probabilistic ignition model is implemented in Ergo/Maeviz, a GIS based risk assessment software platform developed at the Mid-America Earthquake Center at UIUC. Ergo/Maeviz provides the probability of ignition after an earthquake for each building in a region of study, and the overall risk for the community. The developed package in Ergo/Maeviz is validated against number of historical fire following earthquake events. For the future work, the developed fragility curves for buildings under fire will be implemented in Ergo/Maeviz to integrate the probability of ignition and possible damage states of the buildings. This research integrates multi-hazard analysis and risk management to plan mitigation and recovery strategies, and to obtain resilient communities. [less ▲]

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See detailModel polyQ proteins based on the beta-lactamase BlaP: How non-polyQ regions influence the polyQ length-dependent aggregation process
Huynen, Céline ULg

Doctoral thesis (2015)

Neurodegenerative amyloid diseases are fatal disorders representing an important human health and economic burden. Amongst them, nine disorders are classified as polyglutamine (polyQ) diseases, for which ... [more ▼]

Neurodegenerative amyloid diseases are fatal disorders representing an important human health and economic burden. Amongst them, nine disorders are classified as polyglutamine (polyQ) diseases, for which no treatment is yet available. They are all characterized by the pathological expansion of a poly(CAG) sequence, above a specific threshold, within the coding sequence of nine unrelated genes, translated in nine polyQ proteins. The polyQ expansion, the only common point, is the critical determinant for polyQ disease development by triggering protein aggregation into amyloid fibrils. More recent studies however indicate that the protein context modulates the polyQ-induced aggregation process and the disease phenotype. The objectives of my thesis are to deeper investigate the molecular determinants of the complex interplay between the propensity of the polyQ tract to trigger protein aggregation and the modulating role of non-polyQ regions in order to allow the identification of strategies to interfere with the pathological aggregation process. For that purpose, model polyQ proteins, referred to as BlaP-polyQ chimeras, based on the β-lactamase BlaP and polyQ sequences (23 – 79Q) inserted at two positions (197, in between or not unstructured peptides, or 216), are used and their aggregation properties are characterized under several conditions. We first observe that the polyQ length is determinant for BlaP-polyQ chimera aggregation. Indeed, there is a Q-threshold for the aggregation into amyloid fibrils and for fibril elongation. Above this threshold, the aggregation in solution and the elongation rate increase with the length of the polyQ tract, with an exponential rise-to-maximum and a linear regression, respectively, independently of the conformation of the BlaP moiety, and of the position of the polyQ tract within BlaP. Longer polyQ tracts are likely to have a larger conformational flexibility allowing them to more easily adopt an amyloid-aggregation prone conformation. However, the Q-threshold for fibril elongation is much lower than for fibril formation in solution: the polyQ tract requires a larger conformational flexibility to nucleate the formation of fibrils than to elongate them. Secondly, the Q-threshold for fibril formation is lower once the BlaP moiety is unfolded, and BlaP-polyQ chimeras aggregate faster into amyloid fibrils under conditions favoring the unfolding of the BlaP moiety. The native structure of BlaP is likely to impose conformational constraints to moderate and long polyQ tracts that block and decrease, respectively, their propensity to form fibrils. The effects of constraints decrease with the polyQ length. Thirdly, BlaP chimeras with the polyQ tract in position 216 have an increased propensity to trigger the nucleation and the elongation of amyloid fibrils compared to chimeras with the polyQ in position 197. Advanced studies confirm that the propensity of the polyQ tract to aggregate into amyloid fibrils is linked to the conformational flexibility of the polyQ tract, which depends on (i) the polyQ length, (ii) the location of the polyQ tract within BlaP, i.e., a terminal location or embedded within a protein domain, and (iii) the structural properties of the polyQ flanking regions. Finally, we observe that the whole region flanking the polyQ tract in position 197 at its N-terminus has an anti-aggregating property that fully counterbalances the pro-aggregating property of that flanking at the C-terminus. The former imposes strong conformational constraints to the polyQ tract that reduce its conformational flexibility and hence its aggregation propensity. Moreover, these regions are likely to differently affect the solubility of the polyQ protein and hence the driving force for insoluble aggregation. Altogether, our data also suggest that BlaP chimeras aggregate via the commonly described nucleation-dependent polymerization mechanism during which the aggregation is first triggered by polyQ-polyQ interactions, and then a subsequent slight reorganization of the BlaP moiety is required for conversion of aggregates into amyloid fibrils. Based on these results, we should allow the development of therapeutic strategies, targeting specifically the molecular features of the complex interplay between the polyQ and non-polyQ regions during the nucleation and/or elongation of the pathological aggregation of polyQ proteins. [less ▲]

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See detailPourquoi se mobiliser pour la planète rouge?
Stiepen, Arnaud ULg

Conference given outside the academic context (2015)

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See detailWood, the material of tomorrow's retrofits
Ruellan, Guirec ULg; Attia, Shady ULg

in High-quality retrofit and redensification with timber construction systems (2015, June 18)

The construction sector has focused for many years on performance improvement of new constructions. Today's largest problem is the energetic retrofitting of existing buildings. The building retrofit is an ... [more ▼]

The construction sector has focused for many years on performance improvement of new constructions. Today's largest problem is the energetic retrofitting of existing buildings. The building retrofit is an important strategy for energy savings. Building retrofit is addressed towards the real estate in Europe and allows for substantial gains, especially for heating houses and urban densification. However retrofit requires the use of special construction techniques. The problem is quite different from that of the new buildings: adaptation to existing building, heritage conservation, elimination of thermal bridges, etc. In this context, wood is experiencing strong growth in its use in new constructions, due to its qualities. And we think that some of those allow more appropriate responses to retrofit than other traditional materials. In this study, we will first present succinctly the problems related to the renovation, then we will dedicate ourselves to define the characteristics of the wood. The focus will be on some problems that commonly arise in wood constructions. We will then discuss a case, highlighting different characteristics of wood that are particularly important in this particular renovation. This allows us to observe on the ground the coherence of the choice of wood in the renovation. A discussion will close the study by summarizing the advantages and limitations of the use of wood in the renovation This is not to show that wood is one of the most environmentally friendly building materials, or demonstrate the sustainable character of retrofit. This is to see that the timber construction systems can provide an adequate response to many retrofit issues. [less ▲]

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See detailLa limitation du cumul de mandats par les députés wallons
Grandjean, Geoffrey ULg

in Courrier Hebdomadaire du CRISP (2015), 2255-2256

En moyenne, les représentants politiques belges cumulent entre cinq et huit mandats (dont la moitié sont rémunérés). Cette pratique contribue au développement des sentiments de méfiance que nourrit une ... [more ▼]

En moyenne, les représentants politiques belges cumulent entre cinq et huit mandats (dont la moitié sont rémunérés). Cette pratique contribue au développement des sentiments de méfiance que nourrit une partie de la population à l’égard des élus et des institutions. Dans un souci de bonne gouvernance, de nombreux citoyens et acteurs politiques appellent dès lors à une limitation des possibilités légales de cumul de mandats. La traduction récente la plus emblématique de cette préoccupation éthique est le décret décumul adopté en Région wallonne en 2010. Désormais, un député wallon n’a plus le droit de cumuler son mandat avec une fonction de bourgmestre, d’échevin ou de président d’un conseil de l’action sociale. Un quart des membres de chaque groupe politique représenté au Parlement wallon est cependant autorisé à cumuler. Les députés qui bénéficient de cette exception sont désignés sur la base de leur taux de pénétration électorale. Ce mécanisme est le fruit d’un accord politique conclu entre les partenaires du gouvernement régional (PS, Écolo, CDH). Son adoption a fait l’objet de débats nombreux et souvent tendus entre les partis politiques, en ce compris au sein de la majorité. Ce Courrier hebdomadaire retrace l’ensemble du processus législatif à la base du décret décumul. Il replace l’initiative dans son contexte et analyse le jeu des différents acteurs, en réservant une attention particulière aux divers arguments politiques, techniques et surtout juridiques qui ont été mobilisés. G. Grandjean se penche également sur les effets que le décret a eus pour les députés élus lors du scrutin régional wallon du 25 mai 2014. Enfin, il s’interroge sur l’avenir du décret décumul, que certains voudraient réformer, voire supprimer. [less ▲]

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See detailLe saut d'index, on vire à droite ?
Grandjean, Geoffrey ULg

Conference given outside the academic context (2015)

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See detailScreening and analyzing retrofit systems for zero energy renovation and their potential application in Liège, Belgium
Attia, Shady ULg

in AEE INTEC (Ed.) High-quality retrofit and redensification with timber construction systems (2015, June 18)

Retrofit systems for Zero Energy Renovation comes energy as the most topical subject in the Belgian construction sector. Concepts and solutions for zero energy renovation are a new topic. Since 2006 ... [more ▼]

Retrofit systems for Zero Energy Renovation comes energy as the most topical subject in the Belgian construction sector. Concepts and solutions for zero energy renovation are a new topic. Since 2006, Belgium has been striving to achieve the European ambitions of fulfilling the Kyoto Protocol by insulating more effectively and reducing CO2 emissions associated with the use of fossil fuel for operational and embodied energy in buildings. In 2011, a Belgian decree mandated the construction of nearly zero and nets zero energy buildings by 2020. Following the German PassivHaus Standard performance requirements the Belgian residential sector is aiming to achieve an energy consumption to less than 15 kWh/m2/year and an onsite renewable energy production up to 60% for every newly construct household. In this, context the study will build on grounded knowledge developed and implemented by the IEA ECBCS Annex 50: Prefabricated Systems for Low Energy Renovation of Residential Buildings. The goal of this research is to screen and select a series of envelope retrofitting solutions. The focused aim is to demonstrate validated envelope prototypes and products of different zero energy, timber frame construction systems and composite components. This will include the comparison of timber retrofit systems with conventional systems. Thus inform and support the decision making of policy makers, municipalities, developers, and architects and building engineers in Belgium. [less ▲]

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