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See detailRachid Tahzima lauréat du journal of general virology for best oral scientific presentation award 2017
Massart, Sébastien ULg; Tahzima, Rachid

Article for general public (2017)

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See detailRelease of Neutrophils Extracellular Traps as a main trigger for asthma onset
Radermecker, Coraline ULg; Sabatel, Catherine ULg; Toussaint, Marie et al

Poster (2017, June 20)

Allergic asthma is an important Th2 associated immunopathology. Even if the pathology of the disease is well described, its etiology is still largely unknown. Nevertheless, some environmental factors like ... [more ▼]

Allergic asthma is an important Th2 associated immunopathology. Even if the pathology of the disease is well described, its etiology is still largely unknown. Nevertheless, some environmental factors like viral infections and exposition to low doses of lipopolysaccharide (LPS) strongly increase the risk of disease inception. Interestingly, these two particular risk factors both induce a strong recruitment of neutrophils into the lung. Recently, scientists highlighted the ability of neutrophils to form neutrophils extracellular traps (NETs) composed of a network of extracellular DNA associated to anti-microbial peptides. NETs release (or NETosis) is an important component in organism defence against pathogen invasion but has also been identified as initiator of pathophysiological conditions like erythematous systemic lupus, gout and diabetes. In this study, we investigated the role of NETs as potential asthma inducers in specific pro-Th2 environmental risk factors like respiratory viral infections and low LPS doses exposures (also known as hygiene hypothesis). First, we assessed the correlation between respiratory viral infection or low LPS exposure and NETosis using western blot and confocal microscopy analysis. An influenza A infection induced a strong NETs release between day three and seven after viral inoculation whereas exposition to low (100 ng LPS) but not to high (10 µg LPS) LPS doses also promoted NETosis within 24 hours following the exposition. Then we developed two mouse models, a virus-induced asthma model and a model of asthma promoted by exposition to low LPS doses. In these models, only previously infected mice or mice exposed to low LPS doses displayed all the characteristics of allergic asthma following sensitization and challenge to house dust mite (HDM). The role of NETs in asthma onset was then demonstrated using three NETosis inhibitors (DNAse, Cl-amidine and inhibitor of neutrophil elastase) in our models as infected or low LPS doses exposed mice exhibited strong decreased of all key asthma features when treated with NETs inhibitors compared to non-treated mice. Finally, to address how NETs could lead to a TH2 immune response, we analysed by flow cytometry the distinct subpopulations of lung dendritic cells (DCs) in our two mice models. We observed, during the NETs release phase, a recruitment of monocytic derived DCs (moDCs). In conclusion, we have demonstrated an unexpected role for NETs in asthma onset by recruiting lung moDCs. [less ▲]

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Peer Reviewed
See detailChromatographic analysis of alkaloids in Aconitum pollen : towards new insights in plant protection mechanisms
Vanderplanck, Maryse ULg; Glauser, Gaëtan; Tyteca, Eva ULg et al

Conference (2017, June 19)

Alkaloids are a class of naturally occurring organic nitrogen-containing bases that are found primarily in plants. They display a huge diversity with more than 3,000 different types already identified ... [more ▼]

Alkaloids are a class of naturally occurring organic nitrogen-containing bases that are found primarily in plants. They display a huge diversity with more than 3,000 different types already identified. Next to their different pharmacological and therapeutic effects, alkaloids can have a deleterious impact on organisms as they are known to be neurotoxic and cardiotoxic for mammals and insects. In the current context of worldwide bee decline, occurrence of such compounds in floral production, i.e. nectar and pollen, raises major concerns. They could be beneficial to bees by protecting them against disease and pathogens but they could also cause toxicity. Until now alkaloids, and their effect on human health, are mainly studied in vegetative parts of plants. More recently the natural occurrence of alkaloids in nectar was also studied to investigate their effect on bee health. Whereas nectar chemicals can relatively easily and quickly be analyzed by chromatography, extracting chemicals from low pollen amount remains a challenge because of pollen structure and complexity. However, characterization of pollen chemicals can lead to valuable insight in their impact on pollinators allowing the development of mitigation strategies. In this study, we used a UHPLC-(ESI)-Q-ToF/MS method allowing the identification and quantification of alkaloids in pollen matrices from four Aconitum species; A. lycoctonum, A. napellus compactum, A. napellus neomontanum and A. variegatum. Alkaloid extraction was performed using bead-beating disruption of the pollen sample and chromatographic analysis was carried out on an Acquity UPLC system interfaced with a Synapt G2 QTOF. The separation was achieved in gradient mode on an Acquity UPLC BEH C18 column and detection was performed in electrospray positive ionization mode (ES+). Alkaloid concentrations were measured as aconitine equivalents by using a pure aconitine standard as reference compound. The total amount of alkaloids in Aconitum pollen ranged from 0.75 to 1.20 mg/g with 859 different compounds detected, some of them being pollen-specific. Statistical analyses were conducted on the global dataset to assess both quantitative and qualitative interspecific differences. One-way analysis of variance was performed on the total alkaloid content while a permutational test of multivatiate analysis of variance was used to compare the alkaloid profiles among the four Aconitum species. Results are briefly discussed in an ecological context. [less ▲]

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See detailDEVELOPMENT OF A MULTISCALE CONVECTIVE LABSCALE DRYER
Fraikin, Laurent ULg; Salmon, Thierry ULg; Léonard, Angélique ULg

Poster (2017, June 19)

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception ... [more ▼]

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception rules lead to large energy consumptions. In the same perspective, the use of superheated steam as drying fluid expands and requests the improvement of the knowledge about this specific drying process. For this goal, the PEP’s developed a new convective labscale dryer to conduct various studies. This article presents the new dryer called VESAC. [less ▲]

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See detailSTUDY ON THE STRUCTURAL EVOLUTION OF SEWAGE SLUDGE DURING CONVECTIVE DRYING
Li, Jie; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Poster (2017, June 19)

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a ... [more ▼]

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a wastewater treatment plant (Grosses Battes WWTP, Belgium) was chosen for both lab-scale experiment and pilot-scale experiment. X-ray macrotomography (resolution: 0.36 mm per pixel) and X-ray microtomography (resolution: 41 μm per pixel) were used to explore the structure evolution of the sludge bed and the single extrudate respectively. 2D cross-sections of the sludge bed and the single extrudate were acquired, which supply a convenient way to investigate the evolution of the structure. The results show that the structure of both the sludge bed and the single extrudate distinctly changes during the drying process. [less ▲]

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Peer Reviewed
See detailOptimiaztion of an electrophoretic approach for the screening and the development of new antithrombotic drugs
Farcas, Elena ULg; Bouckaert, Charlotte; Servais, Anne-Catherine ULg et al

Poster (2017, June 19)

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations ... [more ▼]

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations. Fragment-based drug discovery (FBDD) approach is an attractive tool for the identification of new selective inhibitors of a target of interest, but its success largely depends on the ability to develop screening bioassays capable to detect and gauge weak affinity binders. To achieve this goal, we investigated capillary electrophoresis (CE) for identifying and ranking fragments from an initial library. Indeed, due to its ability to evaluate weak interactions, CE seems to be promising for fragment-based screening. This technique is a powerful analytical tool with a unique separation mechanism, speed, efficiency and versatility. Its main advantages are low protein consumption, higher throughput compared to NMR and X-ray crystallography and the fact that screening can be carried out using native protein in physiological solution without the need of immobilization. We developed a proof of concept study on thrombin, a serine protease implicated in the coagulation cascade using affinity capillary electrophoresis (ACE) for ranking fragments from an initial library. For this study, we followed a probe ligand, benzamidine, and we investigated interactions with the target by monitoring the changes of its electrophoretic mobility upon binding. The first step of this study consisted in the optimization of the experimental conditions suitable for the CE method (target and probe ligand concentrations, separation buffer composition, voltage, separation effective length, target partial filling…). Then, numerous thrombin inhibitors with a wide range of inhibitory potency (i.e. Ki 200 µM – 5 nM) were tested to validate our system demonstrating the possibility to fish binders in the optimized conditions. We also checked the absence of non-specific binding with the target using the inactivated enzyme at the binding site. It is noteworthy that in this operating system (ACE assay), binding occurs in free solution using physiological buffers, thus preventing artifacts that may result from target immobilization, which is a requirement for some techniques such as SPR. [less ▲]

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See detailMODELING MOISTURE TRANSFER OF MORTAR SUBMITED TO CONVECTIVE DRYING
Kahlerras, Loubna ULg

Poster (2017, June 19)

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See detailGeneralized Pascal triangles for binomial coefficients of finite words
Stipulanti, Manon ULg

Conference (2017, June 19)

We introduce a generalization of Pascal triangle based on binomial coefficients of finite words. These coefficients count the number of times a finite word appears as a subsequence of another finite word ... [more ▼]

We introduce a generalization of Pascal triangle based on binomial coefficients of finite words. These coefficients count the number of times a finite word appears as a subsequence of another finite word. Similarly to the Sierpiński gasket that can be built as the limit set, for the Hausdorff distance, of a convergent sequence of normalized compact blocks extracted from Pascal triangle modulo 2, we describe and study the first properties of the subset of [0, 1] × [0, 1] associated with this extended Pascal triangle modulo a prime p. Then we create a new sequence from this extended Pascal triangle that counts, on each row of this triangle, the number of positive binomial coefficients. We show that this sequence is 2-regular. To extend our work, we construct a Pascal triangle using the Fibonacci representations of all the nonnegative integers and we define the corresponding sequence of which we study the regularity. This regularity is an extension of the classical k-regularity of sequences. [less ▲]

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Peer Reviewed
See detailDesign and experimental validation of an adaptive control law to maximize power generation of a small-scale waste heat recovery system
Hernandez Naranjo, Jairo Andrés ULg; Desideri, Adriano ULg; Gusev, Sergei et al

in Applied Energy (2017), 203

Increasing the energy efficiency of industrial processes is a challenge that involves, not only improving the methodologies for design and manufacturing, but optimizing performance during part-load ... [more ▼]

Increasing the energy efficiency of industrial processes is a challenge that involves, not only improving the methodologies for design and manufacturing, but optimizing performance during part-load operation and transient conditions. A well-adopted solution consists of developing waste heat recovery (WHR) systems based on Organic Rankine Cycle (ORC) power units. The highest efficiency for such cycle is obtained at low superheating values, corresponding to the situation where the system exhibits time-varying nonlinear dynamics, triggered by the fluctuating nature of the waste heat source. In this paper, an adaptive control law using the Model Predictive Control (MPC) framework is proposed. This work goes a step beyond most of the existing scientific works in the field of ORC power systems, since the MPC controller is implemented in a lab-scale prototype, and its performance compared against a gain-scheduled PID strategy. The experimental results show that the adaptive MPC outperforms the gain-scheduled PID based strategy, as it allows to accurately regulate the evaporating temperature, while keeping vapor condition at the inlet of the expander i.e., the superheating, in a safe operating range, thus increasing the net power generation. [less ▲]

Detailed reference viewed: 21 (7 ULg)
See detailPanel moderator: enforcement and remedies
Van Cleynenbreugel, Pieter ULg

Scientific conference (2017, June 17)

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See detailENMG du pied (atelier)
WANG, François-Charles ULg

Conference (2017, June 17)

Detailed reference viewed: 19 (1 ULg)
See detailNCA independence in the context of EU Regulation 1/2003: time to take incongruent accountability realities (more) seriously?
Van Cleynenbreugel, Pieter ULg

Scientific conference (2017, June 16)

This paper argues that the Commission’s reform suggestions aimed at streamlining NCAs into independent administrative agencies appear to neglect this variety of accountability mechanisms underlying ... [more ▼]

This paper argues that the Commission’s reform suggestions aimed at streamlining NCAs into independent administrative agencies appear to neglect this variety of accountability mechanisms underlying current NCA institutional organisation and functioning. Given that those mechanisms each harbour incongruent expectations regarding the organisation and functioning of independent NCAs, failure to acknowledge such incongruence may in practice lead to less effective competition law enforcement. The purpose of this paper is therefore to uncover the different NCA independence perspectives underlying those accountability mechanisms and to look for legally sound ways to make them converge when designing or upgrading NCA independence in the context of the Regulation 1/2003 reform. [less ▲]

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See detailGeneralized Pascal triangles for binomial coefficients of finite words
Stipulanti, Manon ULg

Conference (2017, June 16)

We introduce a generalization of Pascal triangle based on binomial coefficients of finite words. These coefficients count the number of times a finite word appears as a subsequence of another finite word ... [more ▼]

We introduce a generalization of Pascal triangle based on binomial coefficients of finite words. These coefficients count the number of times a finite word appears as a subsequence of another finite word. Similarly to the Sierpiński gasket that can be built as the limit set, for the Hausdorff distance, of a convergent sequence of normalized compact blocks extracted from Pascal triangle modulo 2, we describe and study the first properties of the subset of [0, 1] × [0, 1] associated with this extended Pascal triangle modulo a prime p. Then we create a new sequence from this extended Pascal triangle that counts, on each row of this triangle, the number of positive binomial coefficients. We show that this sequence is 2-regular. To extend our work, we construct a Pascal triangle using the Fibonacci representations of all the nonnegative integers and we define the corresponding sequence of which we study the regularity. This regularity is an extension of the classical k-regularity of sequences. [less ▲]

Detailed reference viewed: 19 (4 ULg)
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See detailFirst Characterization of the Volatile Organic Compounds Emitted by Banana Plants (Musa sp.)
Berhal, Chadi ULg; De Clerck, Caroline ULg; LEVICEK, Carolina et al

Conference (2017, June 16)

Banana fruit (Musa sp.) ranks fourth in developing world's production, and has economical and nutritional key values. The popular and most dominant variety of the dessert banana group is the Cavendish ... [more ▼]

Banana fruit (Musa sp.) ranks fourth in developing world's production, and has economical and nutritional key values. The popular and most dominant variety of the dessert banana group is the Cavendish variety, and Plantain represents that status for the cooking banana group. Despite the importance of the Volatile Organic Compounds (VOCs), which are secondary metabolites with a high vapour pressure, in their utility in the plant protection and communication processes, they were never documented for the plant itself. Thus, the aim of this PHD thesis is to study the VOCs emitted by the plant, rather than their fruits or flowers. A protocol was optimized for the extraction of the banana plant's VOCs. The results of the first analysis showed 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/µl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivars, mainly (Z,E)-α-farnesene (799.64 ± 503.15),(E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). Most of these compounds belong to the terpenes group (8 for Cavendish, 10 for Pacific Plantain). The other compounds detected were ketones, esters and aldehydes. Eight compounds were common between the two varieties (myrcene, Z and E β-ocimene, 6-methyl-5-hepten-2 one, 6-methyl-3,5-hepadien-2-one, a-farnesene, methyl salicylate and β-ionone). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants. [less ▲]

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Peer Reviewed
See detailRelevance of early stretching in overhead athletes
Schwartz, Cédric ULg; Tubez, François ULg; Croisier, Jean-Louis ULg et al

Conference (2017, June 16)

Overhead athletes often develop, over time, a tightness of the posterior structures of the shoulder, which may be associated with injuries. Ten symptomatic (with pain) and ten asymptomatic players with a ... [more ▼]

Overhead athletes often develop, over time, a tightness of the posterior structures of the shoulder, which may be associated with injuries. Ten symptomatic (with pain) and ten asymptomatic players with a tight shoulder were compared and the effect of a self-applied stretching program was evaluated. Before and after the stretching program, pain and stiffness of the shoulder were evaluated. Our results demonstrate that risk factors for shoulder pain such as glenohumeral internal rotation deficit and total range of motion deficit may only be limited in symptomatic athletes. The mobility of the shoulder was significantly improved after the stretching program for both groups. Pain was reduced when present. Because of the limited differences between the symptomatic and asymptomatic athletes, clinicians may find it advantageous to initiate early prevention or rehabilitation programs. [less ▲]

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See detailFrammenti d’intonaci di I stile a Ostia Antica. Un lotto inedito proveniente dagli strati preparatori di un mosaico tardo-repubblicano (Domus dei Bucrani - Camera dei Nani)
Morard, Thomas ULg; Motta, Lucie ULg

Conference (2017, June 16)

Les fouilles entreprises durant les années 2002-2010 sur le site de la Schola del Traiano (IV, IV, 15) à Ostia Antica ont révélé l’existence d’une domus tardo-républicaine - la Domus aux Bucranes (60-20 ... [more ▼]

Les fouilles entreprises durant les années 2002-2010 sur le site de la Schola del Traiano (IV, IV, 15) à Ostia Antica ont révélé l’existence d’une domus tardo-républicaine - la Domus aux Bucranes (60-20 av. J.-C.) - dont le système décoratif de IIe style (pavements, enduits peints et reliefs de stuc, plafonds) est apparu exceptionnellement bien conservé dans les couches les plus profondes de la parcelle urbaine concernée. Ce système décoratif - actuellement en cours de publication - a déjà été présenté à la communauté scientifique lors de différents colloques et journées d’études internationales. Il n’est pas question d’y revenir dans le cadre de la prochaine rencontre de l’AIRPA. En revanche, nous souhaiterions y présenter un lot d’enduits peints de Ier style jetés pêle-mêle dans les couches de préparation du tapis de mosaïque de la Chambre des Nains - un oecus aménagé durant les années 40-30 au sein de cette même domus tardo-républicaine. Restés inédits jusqu’à ce jour, ces fragments comptent parmi les plus anciens jamais découverts à Ostia Antica et leur position stratigraphique - scellée entre deux pavements bien datés - offre à n’en pas douter matière à réflexion. L’ensemble de ces fragments a fait l’objet d’une documentation systématique et des analyses archéométriques ont été portées sur les mortiers et les pigments des éléments les plus significatifs. Ce sont les résultats de cette entreprise scientifique que nous souhaiterions présenter lors du colloque de l'Aquileia afin de pouvoir intégrer cet ensemble décoratif de Ier style dans un corpus plus large - une mise en relation étroite avec le matériel contemporain découvert dans le Latium. [less ▲]

Detailed reference viewed: 23 (2 ULg)