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See detailUn dispositif à visée professionnalisante
Beckers, Jacqueline ULg; Delchambre, Marie ULg; Lourtie, Emilie ULg

in Puzzle (2007), 22

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See detailFasciola hepatica: An assessment of the vectorial capacity of Radix labiata and R. balthica commonly found in Belgium
Caron, Yannick ULg; Lasri, Saadia; Losson, Bertrand ULg

Conference (2007, August)

A previous study in Belgium revealed that genetic material of Fasciola sp. was present in four local snail species: Galba truncatula, Radix peregra, Radix ovata and Lymnaea stagnalis. Laboratory cultures ... [more ▼]

A previous study in Belgium revealed that genetic material of Fasciola sp. was present in four local snail species: Galba truncatula, Radix peregra, Radix ovata and Lymnaea stagnalis. Laboratory cultures of these four species were experimentally infected with F. hepatica. The collected metacercariae were fed to rats and the infection in that vertebrate hosts was monitored through several techniques. The mortality rates in the breeding unit was less than 10 % in G. truncatula, R. peregra, and L. stagnalis colonies. Microscopy revealed the presence of larval stages in 78.3 % and 48 % of G. truncatula and R. peregra snails, respectively. These data were confirmed by a PCR that amplifies a parasite specific sequence. R. peregra shed fewer metacercariae and more irregularly than G. truncatula. In R. ovata and L. stagnalis the infection rates were low. Specific DNA was detected in both cases by PCR but no metacercariae were shed. The metacercariae shed by R. peregra were as infective to rats as those from G. truncatula. The PCR technique was more sensitive than microscopic examination. This study demonstrated that R. peregra may act as an accidental intermediate host for F. hepatica in Belgium. [less ▲]

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See detailThe 8 Learning Events Model: a Pedagogic Conceptual Tool Supporting Diversification of Learning Methods Experienced by the Online Student
Verpoorten, Dominique ULg; Poumay, Marianne ULg; Leclercq, Dieudonné ULg

in Interactive Learning Environments (2007), 15(2), 151-160

This paper presents the 8 Learning Events Model (8LEM), a pedagogical reference framework which was used, in more than 100 online course, as a starting point for instructional planning. Besides supporting ... [more ▼]

This paper presents the 8 Learning Events Model (8LEM), a pedagogical reference framework which was used, in more than 100 online course, as a starting point for instructional planning. Besides supporting teachers in early stages of the learning design continuum, the paper shows how this learning/teaching model, as a professional development tool, prompts them to diversify the learning methods experienced by students in their courses. A two-pronged rationale about the importance of this diversification with respect to "mathetic" competence development and epistemology is also proposed to discussion. [less ▲]

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See detailRhythmic feedback control of a blind planar juggler
Ronsse, R.; Lefevre, Philippe; Sepulchre, Rodolphe ULg

in IEEE Transactions on Robotics (2007), 23(4), 790-802

The paper considers the feedback stabilization of periodic orbits in a planar juggler. The juggler is "blind," i.e, he has no other sensing capabilities than the detection of impact times. The robustness ... [more ▼]

The paper considers the feedback stabilization of periodic orbits in a planar juggler. The juggler is "blind," i.e, he has no other sensing capabilities than the detection of impact times. The robustness analysis of the proposed control suggests that the arms acceleration at impact is a crucial design parameter even though it plays no role in the stability analysis. Analytical results and convergence proofs are provided for a simplified model of the juggler. The control law is then adapted to a more accurate model and validated in an experimental setup. [less ▲]

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See detailShoulder motion analysis using simultaneous skin shape registration.
Schwartz, Cédric ULg; Burdin, V.; Jacq, J. J. et al

in Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (2007, August)

A new non-invasive approach is proposed to study joint motions. It is based on dynamic tracking of the skin shape. A robust simultaneous registration algorithm (Iterative Median Closest Point) is used to ... [more ▼]

A new non-invasive approach is proposed to study joint motions. It is based on dynamic tracking of the skin shape. A robust simultaneous registration algorithm (Iterative Median Closest Point) is used to follow the evolving shape and compute the rigid motion of the underlying bone structures. This new method relies on the differentiation of the rigid and elastic parts of the shape motion. A skin marker network is tracked by a set of infrared cameras. Unlike usual techniques, the algorithm tracks the instantaneous polyhedral shape embedding this network. This innovating approach is expected to minimize bias effect of skin sweeps and give some new information about the underlying soft tissue activities. Current application addresses the motion of the shoulder complex (humerus, clavicle and scapula). It is compared with two marker-based methods published in the literature. Preliminary results show significant differences between these three approaches. The new approach measurements give rise to greater rotations. [less ▲]

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See detailAnti-angiogenic therapy of exudative age-related macular degeneration: current progress and emerging concepts
Noël, Agnès ULg; Jost, Maud; Lambert, Vincent ULg et al

in Trends in Molecular Medicine (2007), 13(8), 345-352

Age-related macular degeneration (AMD) is the leading cause of blindness in elderly patients. The more aggressive exudative form is characterized by abnormal blood-vessel development that occurs beneath ... [more ▼]

Age-related macular degeneration (AMD) is the leading cause of blindness in elderly patients. The more aggressive exudative form is characterized by abnormal blood-vessel development that occurs beneath the retina as a result of choroidal neovascularization (CNV). Vascular endothelial growth factor [VEGF) has emerged as the key mediator of CNV formation; this has led to intensive research on VEGF and the recent approval of anti-VEGF compounds by the US Food and Drug Administration. Despite this successful introduction of anti-angiogenic therapies into the clinical setting, there is still a lack of treatments that definitively reverse damaged vision. Here, we consider the importance of putative molecular targets other than VEGF that might have been underestimated. Emerging cellular mechanisms offer additional opportunities for innovative therapeutic approaches. [less ▲]

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See detailComparaison par modélisation de la production de ruissellement de toitures stockantes (toitures végétalisées et toiture bac)
Beckers, Eléonore ULg

Master's dissertation (2007)

Rainwater runoff management is becoming extremely complex as the result of the increasingly impervious nature of urban and suburban surfaces. Urbanisation can indeed lead to high volumes of surface water ... [more ▼]

Rainwater runoff management is becoming extremely complex as the result of the increasingly impervious nature of urban and suburban surfaces. Urbanisation can indeed lead to high volumes of surface water runoff. This undesirable effect could be reduced by disconnecting roofs from the sewer system. This study represents a first attempt to establish a model concerning green roofs and flat roof storage systems based on a physical approach method. The aim is to deduce their respective effect on water runoff management by analysing and comparing their performance based on a long period of meteorological conditions data (1989-1995). [less ▲]

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See detailInterdomain loop mutation Asp190Cys of the tetracycline efflux transporter TetA(B) decreases affinity for substrate
Sapunaric, Frédéric ULg; Levy, Stuart B.

in Antimicrobial Agents and Chemotherapy (2007)

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See detailMitochondrial complex I encephalomyopathy and cerebral 5-methyltetrahydrofolate deficiency
RAMAEKERS, Vincent ULg; Wels, J.; Sequeira, J. M. et al

in Neuropediatrics (2007), 38(4), 184-187

Folate transport to the brain depends on ATP-driven folate receptor-mediated transport across choroid plexus epithelial cells. Failure of ATP production in Kearns-Sayre syndrome syndrome provides one ... [more ▼]

Folate transport to the brain depends on ATP-driven folate receptor-mediated transport across choroid plexus epithelial cells. Failure of ATP production in Kearns-Sayre syndrome syndrome provides one explanation for the finding of low spinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) levels in this condition. Therefore, we suspect the presence of reduced folate transport across the blood-spinal fluid barrier in other mitochondrial encephalopathies. In the present patient with mitochondrial complex I encephalomyopathy a low 5-methyltetrahydrofolate level was found in the CSF. Serum folate receptor autoantibodies were negative and could not explain the low spinal fluid folate levels. The epileptic seizures did not respond to primidone monotherapy, but addition of ubiquinone-10 and radical scavengers reduced seizure frequency. Add-on treatment with folinic acid led to partial clinical improvement including full control of epilepsy, followed by marked recovery from demyelination of the brainstem, thalamus, basal ganglia and white matter. Cerebral folate deficiency is not only present in Kearns-Sayre syndrome but may also be secondary to the failure of mitochondrial ATP production in other mitochondrial encephalopathies. Treatment with folinic acid in addition to supplementation with radical scavengers and cofactors of deficient respiratory enzymes can result in partial clinical improvement and reversal of abnormal myelination patterns on neuro-imaging. © Georg Thieme Verlag KG Stuttgart. [less ▲]

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See detailFolate receptor autoantibodies and spinal fluid 5-methyltetrahydrofolate deficiency in Rett syndrome
Ramaekers, Vincent ULg; Sequeira, J. M.; Artuch, R. et al

in Neuropediatrics (2007), 38(4), 179-183

Rett syndrome was associated with low cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) in 42-50% of European patients whereas approximately 93% of the patients from North-America had a normal ... [more ▼]

Rett syndrome was associated with low cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) in 42-50% of European patients whereas approximately 93% of the patients from North-America had a normal CSF 5MTHF status. We determined the CSF folate status in Rett patients living in North- and South-Western Europe and measured serum folate receptor (FR) autoantibodies of the blocking type to explain the reduced folate transport across the choroid plexus. Irrespective of their MECP2 genotype and despite normal plasma folate values, 14 of 33 Rett patients (42%) had low CSF folate levels. Blocking FR autoantibodies were found in 8 of the Rett patients (24%), 6 of whom had low CSF folate levels. FR autoimmunity was primarily found within the group of Rett patients with low CSF folate status with a higher incidence in North-Western Europe. In Rett patients from North-America 74 of 76 girls had higher folate values in both serum and CSF than European patients. The food folate fortification in North-America may account for the higher folate levels and may prevent CFD in these Rett patients. FR autoimmunity occurred predominantly in Rett patients from North-Western Europe and may contribute to cerebral folate deficiency (CFD). © Georg Thieme Verlag KG Stuttgart. [less ▲]

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See detailElucidating the altered transcriptional programs in breast cancer using independent component analysis
Teschendorff, A. E.; Journee, Michel ULg; Absil, P.-A. et al

in PLoS Computational Biology (2007), 3(8), 1539-1554

The quantity of mRNA transcripts in a cell is determined by a complex interplay of cooperative and counteracting biological processes. Independent Component Analysis ( ICA) is one of a few number of ... [more ▼]

The quantity of mRNA transcripts in a cell is determined by a complex interplay of cooperative and counteracting biological processes. Independent Component Analysis ( ICA) is one of a few number of unsupervised algorithms that have been applied to microarray gene expression data in an attempt to understand phenotype differences in terms of changes in the activation/ inhibition patterns of biological pathways. While the ICA model has been shown to outperform other linear representations of the data such as Principal Components Analysis ( PCA), a validation using explicit pathway and regulatory element information has not yet been performed. We apply a range of popular ICA algorithms to six of the largest microarray cancer datasets and use pathway- knowledge and regulatory- element databases for validation. We show that ICA outperforms PCA and clustering- based methods in that ICA components map closer to known cancer- related pathways, regulatory modules, and cancer phenotypes. Furthermore, we identify cancer signalling and oncogenic pathways and regulatory modules that play a prominent role in breast cancer and relate the differential activation patterns of these to breast cancer phenotypes. Importantly, we find novel associations linking immune response and epithelial - mesenchymal transition pathways with estrogen receptor status and histological grade, respectively. In addition, we find associations linking the activity levels of biological pathways and transcription factors ( NF1 and NFAT) with clinical outcome in breast cancer. ICA provides a framework for a more biologically relevant interpretation of genomewide transcriptomic data. Adopting ICA as the analysis tool of choice will help understand the phenotype - pathway relationship and thus help elucidate the molecular taxonomy of heterogeneous cancers and of other complex genetic diseases. [less ▲]

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See detailQuantitative onvergence analysis of multi-agent systems
tuna, S. E.; Sepulchre, Rodolphe ULg

in Proceedings of the 7th IFAC Symposium on Nonlinear Control Systems (2007, August)

We introduce a characterization of contraction for bounded convex sets. For discrete-time multi-agent systems we provide an explicit upperbound on the rate of convergence to a consensus under the ... [more ▼]

We introduce a characterization of contraction for bounded convex sets. For discrete-time multi-agent systems we provide an explicit upperbound on the rate of convergence to a consensus under the assumptions of contractiveness and (weak) connectedness (across an interval). Convergence is shown to be exponential when either the system of the function characterizing the contraction is linear [less ▲]

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See detailQualitative—not Quantitative—Deliberative Polling ?
Reuchamps, Min ULg

Conference (2007, July 30)

The last twenty years have seen the emergence of a new generation of polls: the deliberative polls. Unlike usual polling, deliberative polling—first suggested by Fishkin and Luskin—emphasizes not only the ... [more ▼]

The last twenty years have seen the emergence of a new generation of polls: the deliberative polls. Unlike usual polling, deliberative polling—first suggested by Fishkin and Luskin—emphasizes not only the representation of polling but also the deliberation. The deliberative poll attempts to represent all in a given population, through a statistical microcosm empowered to think about the issues in question under favorable conditions—the sample population takes a questionnaire, then is informed through a learning process that alternates discussions in small groups and with experts and politicians, and eventually re-takes the same questionnaire. Although—quantitative—deliberative polling catches the big picture—what people think before and after and how their opinions vary, it hardly gives any insight on why the citizens change their opinions and, above all, what it means after the learning process. This question is especially important in topics where little change of opinions may be expected such as political preferences and identities. Specifically, the qualitative deliberative polling is used to explore the relationship between the citizens’ perception (understood as knowledge, legitimacy, identity, and perception of the others) of the federal government in both Belgium and Canada and their federal preferences vis-à-vis the evolution of the regime. Conducting qualitative and quantitative deliberative polling in those cases seem to offer the best result since the quantitative aspect provides a general picture of the change of opinions while the qualitative aspect endeavors to understand the change of opinions. Qualitative deliberative polling relies on a systematic qualitative content analysis of the focus groups’ discussions and interaction between the participants and the experts. To combine qualitative methods with—quantitative—deliberative polling has the potential to provide a finer picture of the citizens’ opinions on a broad variety of topics and issues. [less ▲]

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See detailImmersive digital games: the interfaces for next-generation e-learning?
Kickmeier-Rust, M. D.; Peirce, N.; Conlan, O. et al

in Lecture Notes in Computer Science (2007), 4556(2007), 647-656

The intrinsic motivation to play, and therefore to learn, that might be provided by digital educational games teases researchers and developers. However, existing educational games often fail in their ... [more ▼]

The intrinsic motivation to play, and therefore to learn, that might be provided by digital educational games teases researchers and developers. However, existing educational games often fail in their attempt to compete with commercial games and to provide successful learning. Often some learning is added to digital games or some gameplay is added to educational applications. Successful educational games, however, require merging professional game design with sound pedagogical strategies, creating a new hybrid format. Moreover, a methodology is required that allows continuously balancing gaming and learning challenges and the learner's abilities and knowledge in order to retain an immersive gaming experience. In this article we introduce approaches to game design and didactic design, as well as a framework for adaptive interventions in educational games. [less ▲]

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See detailStainless steel beam-columns in case of fire
Lopes, Nuno; Vila Real, Paulo; Da Silva, Luis et al

in Beale, R. G. (Ed.) proceedings of the 6th International Conference on Steel and Aluminium Structures ICSAS'07 (2007, July 25)

Eurocode 3 states that stainless steel structural members, subjected to high temperatures, must be designed with the same expressions used on carbon steel members. However, as these two materials have ... [more ▼]

Eurocode 3 states that stainless steel structural members, subjected to high temperatures, must be designed with the same expressions used on carbon steel members. However, as these two materials have different constitutive laws, it should be expected that different formulae for the calculation of member stability should be used for room temperature design. In a recent work, the authors have proposed a more accurate procedure for the evaluation of the fire resistance of stainless steel columns which necessarily affects the beam-column design formulae. This work presents a numerical study of the behaviour of stainless steel beam-columns subjected to fire. [less ▲]

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See detailRise of oceanographic barriers in continuous populations of a cetacean: the genetic structure of harbour porpoises in Old World waters
Fontaine, Michaël C. ULg; Baird, Stuart J. E.; Piry, Sylvain et al

in BMC Biology (2007), 5

BACKGROUND: Understanding the role of seascape in shaping genetic and demographic population structure is highly challenging for marine pelagic species such as cetaceans for which there is generally ... [more ▼]

BACKGROUND: Understanding the role of seascape in shaping genetic and demographic population structure is highly challenging for marine pelagic species such as cetaceans for which there is generally little evidence of what could effectively restrict their dispersal. In the present work, we applied a combination of recent individual-based landscape genetic approaches to investigate the population genetic structure of a highly mobile extensive range cetacean, the harbour porpoise in the eastern North Atlantic, with regards to oceanographic characteristics that could constrain its dispersal. RESULTS: Analyses of 10 microsatellite loci for 752 individuals revealed that most of the sampled range in the eastern North Atlantic behaves as a 'continuous' population that widely extends over thousands of kilometres with significant isolation by distance (IBD). However, strong barriers to gene flow were detected in the south-eastern part of the range. These barriers coincided with profound changes in environmental characteristics and isolated, on a relatively small scale, porpoises from Iberian waters and on a larger scale porpoises from the Black Sea. CONCLUSION: The presence of these barriers to gene flow that coincide with profound changes in oceanographic features, together with the spatial variation in IBD strength, provide for the first time strong evidence that physical processes have a major impact on the demographic and genetic structure of a cetacean. This genetic pattern further suggests habitat-related fragmentation of the porpoise range that is likely to intensify with predicted surface ocean warming. [less ▲]

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See detailExperimental investigations on the behaviour of a composite frame after the loss of a column
Demonceau, Jean-François ULg; Jaspart, Jean-Pierre ULg

in Beale, R. G. (Ed.) Proceeding of the 6th International Conference on Steel and Aluminium Structures (2007, July 24)

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under exceptional loading, i.e. other accidental loads than ... [more ▼]

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under exceptional loading, i.e. other accidental loads than those already taken into consideration in the design process. According to Eurocodes and some other national design codes, the structural integrity of civil engineering structures should be ensured through appropriate measures but, in most of the cases, no precise practical guidelines on how to achieve this goal are provided. Even basic requirements to fulfil are generally not clearly expressed. An European RFCS project called “Robust structures by joint ductility” has been set up in 2004, for three years, with the aim to provide requirements and practical guidelines allowing to ensure the structural integrity of steel and composite structures under exceptional loading through an appropriate robustness. This project involves analytical, numerical and experimental investigations; in particular, one substructure test simulating the loss of a column in a composite building, because of an unexpected impact, was performed in September 2006 at the University of Liège. This paper describes the experimental test carried out at the University of Liège, as part of this European project, and the first interpretation of the results. [less ▲]

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See detailPromoter-dependent effect of IKK alpha on NF-kappa B/p65 DNA binding
Gloire, Geoffrey ULg; Horion, Julie; El Mjiyad, Nadia ULg et al

in Journal of Biological Chemistry (2007), 282(29), 21308-21318

IKK alpha regulates many chromatin events in the nuclear phase of the NF-kappa B program, including phosphorylation of histone H3 and removal of co-repressors from NF-kappa B-dependent promoters. However ... [more ▼]

IKK alpha regulates many chromatin events in the nuclear phase of the NF-kappa B program, including phosphorylation of histone H3 and removal of co-repressors from NF-kappa B-dependent promoters. However, all of the nuclear functions of IKK alpha are not understood. In this study, using mouse embryonic fibroblasts IKK alpha knock-out and reexpressing IKK alpha after retroviral transduction, we demonstrate that IKK alpha contributes to NF-kappa B/p65 DNA binding activity on an exogenous kappa B element and on some, but not all, endogenous NF-kappa B-target promoters. Indeed, p65 chromatin immunoprecipitation assays revealed that IKK alpha is crucial for p65 binding on kappa B sites of icam-1 and mcp-1 promoters but not on i kappa b alpha promoter. The mutation of IKK alpha putative nuclear localization sequence, which prevents its nuclear translocation, or of crucial serines in the IKK alpha activation loop completely inhibits p65 binding on icam-1 and mcp-1 promoters and rather enhances p65 binding on the i kappa b alpha promoter. Further molecular studies demonstrated that the removal of chromatin-bound HDAC3, a histone deacetylase inhibiting p65 DNA binding, is differentially regulated by IKK alpha in a promoter-specific manner. Indeed, whereas the absence of IKK alpha induces HDAC3 recruitment and repression on the icam-1 promoter, it has an opposite effect on the i kappa b alpha promoter, where a better p65 binding occurs. We conclude that nuclear IKK alpha is required for p65 DNA binding in a gene-specific manner. [less ▲]

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