References of "2012"
     in
Bookmark and Share    
Full Text
See detailMulti-row approaches to cutting plane generation
Poirrier, Laurent ULg

Doctoral thesis (2012)

This thesis focuses on the use of cutting-plane techniques to improve general-purpose mixed-integer linear programming solvers. The first topic covered here is a fast separation method for two-row cuts ... [more ▼]

This thesis focuses on the use of cutting-plane techniques to improve general-purpose mixed-integer linear programming solvers. The first topic covered here is a fast separation method for two-row cuts. Two-row cuts are intersection cuts from two rows of a simplex tableau describing the LP relaxation of the problem. This type of cuts recently gathered a lot of attention from the scientific community following a paper by Andersen, Louveaux, Weismantel and Wolsey describing the facets of the underlying two-row model and providing an intuitive geometric classification the the derived cuts. The specificity of the approach adopted here is that it does not rely on an "infinite relaxation" point of view and generate intersection cuts from fixed lattice-free sets. Instead, given a fractional point, it aims at always finding a most violated facet-defining inequality for the two-row model. This can be achieved by optimizing over the polar set of the integer hull of the model. A fast way of performing this is provided, by means of a polyhedron that is equivalent to the polar for that purpose, but has a more compact representation. Moreover, a row-generation algorithm is developed in order to avoid the costly computations of integer hulls of two-dimensional cones. An implementation of the resulting algorithm performs separation of two-row cuts in a few milliseconds on average, on the standard MIPLIB 3 and 2003 testsets. While this two-row separator is quick, the measurements of the computational usefulness of the cuts do not yield satisfactory results. Since all the cuts generated are facet-defining, this might suggest that the underlying two-row models are too weak. This observation prompted the second part of this thesis, an attempt to evaluate the strength of various multi-row relaxations, on small instances, using a generic separator. To that end, a separator is developed, which is able to compute facet-defining inequalities from arbitrary (yet reasonably small) mixed-integer sets. A row-generation approach is again adopted, but this time the slave part consists in the resolution of a mixed-integer problem instead of a closed-form oracle. Some interesting computational tricks are developed, in order to speedup the inherently hard computations. [less ▲]

Detailed reference viewed: 66 (14 ULg)
See detailA propos de la notion de la "paysage attributif" : l’exemple de la céramique apulienne
Morard, Thomas ULg

Scientific conference (2012, December 17)

Detailed reference viewed: 32 (3 ULg)
See detailExploration of the neurocognitive mecanisms of memory awareness in Alzheimer’s disease (AD).
Genon, Sarah ULg

Scientific conference (2012, December 17)

Detailed reference viewed: 22 (3 ULg)
Full Text
See detailQualité de vie des enfants atteints de mucoviscidose et de leurs parents: Quels sont les prédicteurs?
Toucheque, Malorie ULg; Lemétayer, Fabienne; Missotten, Pierre ULg et al

Poster (2012, December 17)

Introduction. La mucoviscidose est une maladie génétique grave, limitant la durée de vie du patient et entraînant de nombreuses complications. Les progrès scientifiques et médicaux ont conduit à ... [more ▼]

Introduction. La mucoviscidose est une maladie génétique grave, limitant la durée de vie du patient et entraînant de nombreuses complications. Les progrès scientifiques et médicaux ont conduit à l’augmentation de l’espérance de vie, de sorte que l’âge moyen de survie est d’environ 40 ans. Dans ce contexte, la qualité de vie (QV) est devenue un objectif thérapeutique important pour les patients atteints de mucoviscidose. Cependant, malgré un intérêt croissant pour le QV, celle-ci a été sous-investiguée chez les enfants âgés de 6 à 12 ans. Parallèlement, on observe que les professionnels de la santé ne sont plus seuls à intervenir dans la prise en charge du jeune patient. L’essentiel du traitement ayant lieu à la maison, la responsabilité concernant la gestion de la maladie reposent désormais sur les épaules de la famille. Ainsi, les parents d’enfants atteints de mucoviscidose doivent faire face à une variété de stresseurs pouvant entraîner d’importantes implications pour le bien-être psychosocial du système familial. Ces dernières années, le rôle de la famille dans l’adaptation des enfants atteints d’une maladie chronique a reçu une attention particulière. À l’heure actuelle, on reconnaît l’importance et l’influence de la relation parent-enfant dans de multiples aspects du développement social et émotionnel de l’enfant. Cependant, dans les recherches en pédiatrie, les pères sont sous-représentés. C’est principalement la relation mère-enfant malade qui a été pris en considération en ignorant la relation père-enfant malade. Objectifs. Ce projet de thèse s’oriente autour de trois objectifs : (1) étudier l’impact de la mucoviscidose sur la QV et, de manière plus générale, sur l’ajustement de l’enfant et de ses parents ; (2) comprendre le lien entre l’ajustement des parents et celui de l’enfant et identifier les mécanismes spécifiques par lesquels les parents influent sur la QV de l’enfant ; (3) étudier l’effet du genre. Méthodologie. Chaque triade (enfant, père et mère) devra répondre à un ensemble de questionnaire évaluant l’ajustement émotionnel, cognitif et comportemental ainsi que le fonctionnement familial et la qualité de vie. Afin d'isoler la spécificité de la mucoviscidose, trois groupes seront créés : mucoviscidose – asthme – sain. Le début du recrutement est prévu en septembre 2012. Contribution. Cette recherche se veut intégrative et contribuera à mettre en évidence les facteurs prédicteurs de la résilience et des difficultés d’ajustement chez les enfants souffrant de mucoviscidose et leur parent. Les résultats contribueront à l’avancement des connaissances et nous permettraient d’influer sur les initiatives de prévention. [less ▲]

Detailed reference viewed: 97 (10 ULg)
See detailRéflexion pure, Vérité, Violence. Pour une pensée de la conditionnalité. Lecture croisée de Sartre et d'un texte tibétain
Filipucci, Alexis ULg

Doctoral thesis (2012)

In this work, a systematic reading of Sartre's philosophy is intended. Methodogically, we use a highly systematic thought of a Tibetan philosopher, Ju Mipham. Having translated one work of this Buddhist ... [more ▼]

In this work, a systematic reading of Sartre's philosophy is intended. Methodogically, we use a highly systematic thought of a Tibetan philosopher, Ju Mipham. Having translated one work of this Buddhist writer, we observe how the process of the hermeneutical spiral between two philosophies born in different cultural areas helps us to understand in a deeper manner these two thoughts. [less ▲]

Detailed reference viewed: 61 (10 ULg)
See detailThe functional neuroanatomy of tinnitus: insights from resting-state fMRI
Maudoux, Audrey ULg

Doctoral thesis (2012)

Detailed reference viewed: 15 (5 ULg)
Full Text
See detailLa fonction mitochondriale des cellules musculaires squelettiques équines en culture : effet de l'anoxie et des neutrophiles activés.
Ceusters, Justine ULg

Doctoral thesis (2012)

Introduction Horses are known to be remarkable athletes. However, to realize such repeated intense exercises, as competition horses do, and could also became a stressing condition leading to muscular ... [more ▼]

Introduction Horses are known to be remarkable athletes. However, to realize such repeated intense exercises, as competition horses do, and could also became a stressing condition leading to muscular dysfunctions but could also decrease their performances. In horses, lesions from ischemia/reperfusion are found in numerous clinical situations but also during intense exercise, the muscular oxygenation decreasing as a function of the exercise intensity. But it is during the reoxygenation, with the subsequent increase of the electron flux within the mitochondrial respiratory electron transport chain at the cessation of exercise, that an important increase of the reactive oxygen and nitrogen species (RNOS) production will be observed. The realization of such intense exercise provokes also an important systemic inflammatory reaction. Recently, some studies realized by our group on competing horses showed that intense exercise can activate the polymorphonuclear neutrophils (PMNs) which degranulate their myeloperoxidase (MPO) and elastase (ELT). The increase of MPO was not only plasmatic but also muscular, where it was associated with a decrease of the mitochondrial complex I activity, showing there a possible link between the MPO activity and the mitochondrial dysfunction in horses performing exercise. The relationship between ischemia/reperfusion, ROS production from mitochondria, muscular damages and inflammatory reaction is largely unexplored in horses. The principal objectives of this work were to study, on a primary culture of equine skeletal muscle cells obtained from muscular microbiopsies, the effect of anoxia/reoxygenation (A/R) and/or of MPO on their ROS production and mitochondrial respiratory function. Results Primary culture of equine skeletal muscle cells from muscular microbiopsies With muscular microbiopsies, we developed an efficient and convenient sampling method, usable in current practice and even on high level competing horses. By using the microbiopsies as explants, we obtained a primary culture of skeletal muscle cells, a suitable experimental model for the in vitro study of equine muscular function. Model of anoxia/reoxygenation applied on cultured equine skeletal muscle cells Thanks to the primary culture, we showed by fluorescence spectroscopy and gas chromatography, an increased ROS production by adherent cells submitted to 2 h of A/R. For the following investigations, 2 other models were designed on detached cells : a first one of cyclic A/R (2 x 30 min) and a second one of a single long period of 1 h, 2 h or 3 h of A/R. The first one showed a decrease of the routine respiration, but also of ROS production and of the mitochondrial complex I specific activity of the cells submitted to cyclic A/R. After a single long period of A/R, on the contrary, the routine respiration, the ROS production and the mitochondrial complex I specific activity of the cells were increased while the ATP production by these cells was decreased. This observation, arguing for an uncoupling of the oxidative phosphorylation, prompted us to investigate the uncoupling protein 3 (UCP3) expression by cultured cells. The indirect immunofluorescence, as well as the electrophoresis coupled with the western blot, showed that they expressed UCP3, in normoxia and after 2 h of A/R, but also that this expression varied as a function of the duration of the A/R, with a maximum observed for 2 h. The oxygraphic phosphorylation control protocol (PCP) applied on detached cells showed an increase of their routine but also of their non phosphorylating (after ATP synthase inhibition) respirations after a single long period of 2 h A/R. Their maximal respiratory capacity, per contra, decreased significantly. When regarding the flux control ratios (FCR, related to maximal respiratory capacity), we confirmed that cells submitted to 2 h of A/R need to function more to keep stable their energetic state (increase of the part of their maximal respiratory capacity used for oxidative phosphorylation because of a lesser efficiency). Inflammatory model Equine neutrophils activation in whole blood All the activation systems used, 12-phorbol 13-myristate acetate (PMA), cytochalasin B with N-formyl-methionyl-leucyl-phenylalanine (CB/fMLP), tumor necrosis factor-alpha (TNF- α), lipopolysaccharides (LPS) and LPS with TNF-α, induced a significant degranulation of total MPO by the PMNs activated in whole blood. Only the combinations CB/fMLP and LPS/TNF-α caused a significant release of active MPO. For the release of ELT by activated PMNs, only the action of the PMA was significant. Use of purified active equine MPO Initially, we showed that MPO incubated with equine skeletal muscle cells was able to bind to the cell membranes, but furthermore, thanks to the differential centrifugation protocol, that we demonstrated that it was able to enter within the cells, because we found it in the cytosolic fraction. Our following experiences showed that it was able, even alone, to increase the ROS produced by the cells, as demonstrated by fluorescence and gas chromatography. Furthermore, MPO worked harder than Horseradish peroxidase (HRP), our "peroxidasic control". The MPO seemed also to alter the mitochondrial respiratory function of cultured cells. Anyway, thanks to the oxygraphic PCP protocol, we showed that MPO alone decreased mostly their routine respiration and their maximal respiratory capacity. Paradoxically, we seen that it increased the part of the maximal respiratory capacity used for routine and non phosphorylating respirations. The second oxygraphic protocol, designed on permeabilized cells, seems to confirm these observations. Compared to control cells, the MPO-treated cells had a increased non phosphorylating respiration and a decreased maximal respiratory capacity, particularly via the mitochondrial complex I. Combined model: anoxia/reoxygenation in inflammatory conditions With fluorescence spectroscopy as well as with gas chromatography, the MPO amplifies the ROS production already increased with the A/R alone. Furthermore, with a 3,3-diaminobenzidine (DAB) coloration, we showed the persistence of the MPO (and of the HRP), within the cells, even after 2 h of A/R. The oxygraphic PCP protocol confirms that MPO seems to exacerbate the damage initiated by A/R. Thus, compared to what we observed with A/R alone, the addition of MPO causes a further decrease of the routine respiration and the maximal respiratory capacity of the cells and increases their non phosphorylating respiration. These observations, along the lines of an important mitochondrial dysfunction, were confirmed when regarding the FCR. Thus, MPO-treated cells, submitted to A/R need to use a greater part of their maximal respiratory capacity for routine respiration, but a greater part of it was also used for non efficient respiration. So, these cells need to work more intensely to keep stable their energetic state, what is reflected in our protocol by an increased part of the maximal respiratory capacity used for oxidative phosphorylation compared to what we observed after A/R alone. Conclusion and perspectives During intense exercise, some physiopathological conditions, inducing important mitochondrial and energetic alterations, seem to gather within the muscle of sport horses. As showed by our work, because of its implication in the mitochondrial regulation at the respiratory level as well as for RNOS production, and of its particular sensibility to nitration, the mitochondrial complex I could play a pivotal role. Although our results clearly indicate that MPO, by exacerbating the deleterious effects of A/R, is detrimental to cellular and mitochondrial functions, further precisions are needed to confirm the specific implication of mitochondrial complex I in the observed phenomena. The results obtained by our group in vivo on competing horses lead the way in this direction but, the adaptation of the oxygraphic protocol on permeabilized cells, combining A/R with the action of MPO, will help to confirm, in vitro, the hypothesis. On another way, the effect of nitration or nitrosation on the mitochondrial complex I will need to be further investigated. Finally, to consider in a largest way the action of the PMNs on the mitochondrial function, it will be interesting to use the whole blood model of PMNs activation in co-culture with equine skeletal myoblasts. By this way, the action of other inflammatory factors or mediators could be studied in conditions nearly to the ones observed in vivo. [less ▲]

Detailed reference viewed: 82 (25 ULg)
Full Text
Peer Reviewed
See detailFinal analysis of overall survival for the Phase III CONFIRM trial: fulvestrant 500 mg versus 250 mg
DI LEO, Angelo; JERUSALEM, Guy ULg; PETRUZELKA, Lubos et al

in Cancer Research. Supplement (2012, December 15), 72(24), 1-4

Detailed reference viewed: 16 (8 ULg)
Full Text
See detailHumanisation de la marque et web 2.0
Brandt, Céline ULg

Article for general public (2012)

La personnification est l’action de représenter sous les traits d’une personne une chose abstraite ou inanimée. Au sein des réseaux sociaux, les consommateurs souhaitent s’adresser directement au porte ... [more ▼]

La personnification est l’action de représenter sous les traits d’une personne une chose abstraite ou inanimée. Au sein des réseaux sociaux, les consommateurs souhaitent s’adresser directement au porte-parole de la marque, en général le dirigeant de la société. Les conséquences de ce type de communication personnelle sur le comportement du consommateur sont l’amélioration de la confiance, la satisfaction et l’engagement du consommateur. [less ▲]

Detailed reference viewed: 61 (11 ULg)
Full Text
Peer Reviewed
See detailAn in vitro whole blood model to test the effects of different stimuli conditions on the release of myeloperoxidase and elastase by equine neutrophils.
Ceusters, Justine ULg; Serteyn, Didier ULg; MINGUET, Grégory ULg et al

in Veterinary Immunology and Immunopathology (2012), 150(3-4), 221-7

Horses are particularly sensitive and exposed to excessive inflammatory responses evolving toward an important stimulation of polymorphonuclear neutrophils (PMNs). The aim of this work was to stimulate ... [more ▼]

Horses are particularly sensitive and exposed to excessive inflammatory responses evolving toward an important stimulation of polymorphonuclear neutrophils (PMNs). The aim of this work was to stimulate equine neutrophils in whole blood and to evaluate their response by measuring the release of total and active myeloperoxidase (MPO) and total elastase, considered as markers of neutrophil stimulation and degranulation. Because of the critical importance of the concomitant presence of LPS and TNF-alpha in equine pathological situations, we combined these two natural mediators to stimulate PMN and compared the response with those obtained after the PMN stimulation with each mediator used alone and well-known artificial stimulation systems such as 12-phorbol 13-myristate acetate (PMA) and the combination of cytochalasin B (CB) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). All the activation systems, PMA, CB/fMLP, TNF-alpha, LPS and LPS/TNF-alpha, induced a significant release of total MPO in whole blood but only the combinations CB/fMLP and LPS/TNF-alpha significantly favored the release of active MPO. Regarding the total elastase, we did not observe a significant release in all the stimulated conditions except with PMA. It appears clearly that the choice of the neutrophil stimulation model is fundamental for the selection of potentially active pharmacological agents, especially on MPO activity. [less ▲]

Detailed reference viewed: 32 (17 ULg)
See detailAdaptation et pathologie de l'adaptation : comment contourner le piège du pathomorphisme ?
Englebert, Jérôme ULg

Scientific conference (2012, December 15)

Detailed reference viewed: 42 (5 ULg)
Full Text
See detailViande rouge : toujours d'actualité !
Beckers, Yves ULg

Conference given outside the academic context (2012)

Detailed reference viewed: 50 (11 ULg)
See detailLe témoignage audiovisuel à l'ère des images digitales
Van Cauwenberge, Geneviève ULg

Conference (2012, December 14)

Detailed reference viewed: 14 (3 ULg)