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See detailLe pouvoir politique des juges
Grandjean, Geoffrey ULg

Conference given outside the academic context (2017)

Notre société est marquée par un phénomène de judiciarisation qui voit une emprise croissante des juges dans les systèmes politiques et sociaux. Certains représentants n'hésitent d'ailleurs plus à ... [more ▼]

Notre société est marquée par un phénomène de judiciarisation qui voit une emprise croissante des juges dans les systèmes politiques et sociaux. Certains représentants n'hésitent d'ailleurs plus à fustiger le « gouvernement des juges ». Quels pouvoirs les juges exercent-ils dans nos systèmes démocratiques ? Pour répondre à cette question, il est proposé de présenter les trois grandes fonctions politiques des juges : 1) la production de normes, 2) l'arbitrage de valeurs morales et 3) la stabilisation du système politique. Ces trois fonctions sont autant de déclinaisons du pouvoir politique des juges qui concrétisent un nouvel équilibre entre les pouvoirs. De nombreuses décisions de jurisprudence illustrent le propos. [less ▲]

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See detailMorphology Development and Mechanical Properties Variation during Cold-Drawing of Polyethylene-Clay Nanocomposite Fibers
Coppola, Bartolomeo ULg; Scarfato, Paola; Incarnato, Loredana et al

in Polymers (2017), 9(6), 235-251

In this work, the influence of composition and cold-drawing on nano- and micro-scale morphology and tensile mechanical properties of PE/organoclay nanocomposite fibers was investigated. Nanocomposites ... [more ▼]

In this work, the influence of composition and cold-drawing on nano- and micro-scale morphology and tensile mechanical properties of PE/organoclay nanocomposite fibers was investigated. Nanocomposites were prepared by melt compounding in a twin-screw extruder, using a maleic anhydride grafted linear low density polyethylene (LLDPE–g–MA) and an organomodified montmorillonite (Dellite 67G) at three different loadings (3, 5 and 10 wt %). Fibers were produced by a single-screw extruder and drawn at five draw ratios (DRs): 7.25, 10, 13.5, 16 and 19. All nanocomposites, characterized by XRD, SEM, TEM, and FT-IR techniques, showed an intercalated/exfoliated morphology. The study evidenced that the nanoclay presence significantly increases both elastic modulus (up to +115% for fibers containing 10 wt % of D67G) and drawability of as-spun nanocomposite fibers. Moreover, at fixed nanocomposite composition, the cold-drawing process increases fibers elastic modulus and tensile strength at increasing DRs. However, at high DRs, “face-to-edge” rearrangement phenomena of clay layers (i.e., clay layers tend to rotate and touch each other) arise in fibers at high nanoclay loadings. Finally, nanocomposite fibers show a lower diameter reduction during drawing, with respect to the plain system, and surface feature of adjustable roughness by controlling the composition and the drawing conditions. [less ▲]

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See detailCharacterisation of Luvisol compaction under two different tillage systems and field traffic zones by assessing soil mechanical properties
Taguem Ngoualadjio, Eric Martial ULg; Destain, Marie-France ULg; ROISIN, Christian et al

Conference (2017, June 20)

Compaction of arable soils is a consequence of tillage systems and agricultural machinery traffic year after year. Its negative effects on crop production and on the environment have been put into ... [more ▼]

Compaction of arable soils is a consequence of tillage systems and agricultural machinery traffic year after year. Its negative effects on crop production and on the environment have been put into evidence by several studies. However, soil compaction is a complex phenomenon and the understanding of the involved mechanisms related to agricultural practices still remains limited. This contribution aims to study the influence of the interaction between traffic intensity and tillage system on soil compaction. Soil samples were taken from topsoil (0.07-0.25 m), plough pan (0.30-0.35 m) and subsoil (0.35 – 0.52 m), on plots under long-term reduced tillage (RT) and conventional tillage (CT). For each tillage system, intensive traffic zones (IT) and non-intensive traffic zones (NT) were considered. Swelling index (Cs), compression index (Cc), precompression stress (Pc) obtained by oedometer test, porosity (n) and water content obtained by gravimetric determination were chosen to characterise the soil mechanical properties. An analysis of covariance (ANCOVA) was performed to study the effect of the depth, the tillage and the traffic intensity on the variables measured, with the water content as covariable. The results show that, after ten years of reconversion from CT to RT, the plough pan is still present in RT and its compaction appears as important as in CT ( nRT-30cm = 36.9% , nCT-30cm = 38.0%, p-value = 0.098). In subsoil, the compression index was high in CT, as well as in RT (CcRT = 0.150 kPa-1, CcCT = 0.148 kPa-1, p-value = 0.617), involving that this layer remains susceptible to compaction under heavy loads. Moreover, the mean value of the precompression stress (meanPc = 92±34 kPa) remains lower than stresses induced by heavy machines such as beet harvesters. The results also show that the presence of two traffic zones induces a spatial heterogeneity in the field (CcIT = 0.138 kPa-1; CcNT = 0.154 kPa-1, p-value = 0.031). These main results could be used in computational modelling to develop decision support systems to mitigate the effects of soil compaction. [less ▲]

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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)

Detailed reference viewed: 19 (3 ULg)
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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See detailOptimization 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

Conference (2017, June 20)

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

Poster (2017, June 19)

Detailed reference viewed: 18 (1 ULg)
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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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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 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 ▲]

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See detailDEVELOPMENT AND VALIDATION OF A FAST SFC METHOD FOR THE ANALYSIS OF FLAVONOIDS IN PLANT EXTRACTS
Huang, Yang ULg; Jiang, Zhengjin; Fillet, Marianne ULg et al

Poster (2017, June 18)

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the ... [more ▼]

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the separation of 12 flavonoids. After careful optimization, the 12 flavonoids were baseline separated on a ZORBAX RX-SIL column using gradient elution. A 0.1% phosphoric acid solution in methanol was found to be the most suitable polar mobile phase component for the separation of flavonoids. From the viewpoint of retention and resolution, a backpressure of 200 bar and a temperature of 40 °C were shown to give the best results. Compared with a previously developed reverse phase liquid chromatography method, the SFC method could provide flavonoid separations that were about three times faster, while maintaining good peak shape and comparable peak efficiency. This SFC method was validated and applied to the analysis of five flavonoids (kaempferol, luteolin, quercetin, luteoloside, buddleoside) present in Chrysanthemum morifolium Ramat. from different cultivars (Chuju, Gongju, Hangju, Boju). The results indicated a good repeatability and sensitivity for the quantification of the five analytes with RSDs for overall precision lower than 3%. The limits of detection ranged from 0.73 to 2.34 μg/mL, while the limits of quantification were between 2.19 and 5.86 μg/mL. The method showed that SFC could be employed as a useful tool for the quality assessment of Traditional Chinese medicines (TCMs) containing flavonoids as active components. [less ▲]

Detailed reference viewed: 11 (1 ULg)
See detailPanel moderator: enforcement and remedies
Van Cleynenbreugel, Pieter ULg

Scientific conference (2017, June 17)

Detailed reference viewed: 13 (0 ULg)
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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 ▲]

Detailed reference viewed: 6 (0 ULg)