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See detailInfluence of dipole-dipole interactions on the superradiant pulse
Damanet, François ULg; Martin, John ULg

Poster (2013, May 23)

Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and ... [more ▼]

Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and single photon cooperative emission [2]. The dissipative dynamics of the atoms is known to depend dramatically on the ratio between the typical inter-atomic distance and the atomic transition wavelength, notably because of dipole-dipole interactions [3]. In this work, we study the effects of these interactions on superradiance as in [4] by solving numerically the corresponding master equation. In particular, by averaging over many realizations of the randomly distributed atomic positions, we show that the decay of the radiated energy pulse height with the intensity of the dipolar coupling follows a power law. [1] E. Ackermans, A. Gero & R. Kaiser, Phys. Rev. Lett. 101, 103602 (2008). [2] R. Friedberg & J. T. Manassah, J. Phys. B 43, 035501 (2010). [3] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [4] B. Coffey & R. Friedberg, Phys. Rev. A 17, 1033 (1978). [less ▲]

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See detailAssessment of a 3S rotary atomizer
Ouled Taleb Salah, Sofiene ULg; Massinon, Mathieu ULg; Lebeau, Frédéric ULg

Poster (2013, May 23)

Spinning disc sprayers were first introduced to control cotton pests and diseases. These atomizers were recognized for their production of a uniform droplet size spectrum than conventional nozzles. They ... [more ▼]

Spinning disc sprayers were first introduced to control cotton pests and diseases. These atomizers were recognized for their production of a uniform droplet size spectrum than conventional nozzles. They have proved to be the most successful way of delivering pesticides in the form of Controlled Droplet Application (CDA) at very low volume application. But they were almost abandoned since the years of 1990 for high and medium volume application. Their use was found inefficient in arable crops such as cereals due to the use of inappropriate application rate and problem of penetration of spray in cereal canopies. However, these spray generators may be the best solution when the spray was to be targeted to a small weed with hydrophobic leaf surface where adhesion in the impact is essential for treatment efficiency while minimizing drift and splash thanks to reduced droplet span. In this study, aiming to maximize the control of black grass in cereals, characterization of the droplet size spectra was performed to predict the trajectory droplet and estimate the number that will hit the targeted surface. So, a CDA Micromax Ltd rotary atomizer 3S was operated at different rotation speeds (2000, 3500 and 5000 rpm), flow rates and pressures. A camera X stream -3S which allows the acquisition images in PIV mode, connected to a led lightening set at double mode exposure, were placed in front of the edge of the disc on a spray bench. Images were treated through a laboratory developed Matlab code for Particle Tracking Velocimetry Sizing. Droplets speeds according to diameters were extracted. Droplets cumulative volume according to diameters was also obtained. As the flow rate rose, the volume median diameter (VMD) increased. On the other hand, the VMD decreased as the rotation speed increased. Satellites droplets were observed when the atomizer was operating at a disc speed of 2000 rpm. For each flow rate corresponding to a drop size VMD, the number of droplets/cm2 that will affect pesticide coverage was calculated. Thus, the number of droplets that will effectively adhere depend on their impact at the moment of their arrival to the surface target. [less ▲]

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See detailThe most non-classical symmetric states of an N-qubit system
Baguette, Dorian ULg; Martin, John ULg

Poster (2013, May 23)

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See detailA clinical case of congenital tremors in piglets without evidence of PCV-1 and PCV-2
wavreille; Simon, Fanny (Co-first author); Servais, Vincent et al

Poster (2013, May 22)

Congenital tremor (CT) is a disease of newborn pigs characterized by spontaneous clonic contractions of one or more groups of voluntary muscles. Besides suspected or confirmed etiologies of CT such as ... [more ▼]

Congenital tremor (CT) is a disease of newborn pigs characterized by spontaneous clonic contractions of one or more groups of voluntary muscles. Besides suspected or confirmed etiologies of CT such as classical swine fever virus, pseudorabies virus, Japanese encephalomyelitis virus, hereditary disorders in Landrace or Saddleback pigs, organophosphorus poisoning etc., porcine circovirus (PCV) has been described as a potential cause of CT. The type AII seems to be the most common form of CT. Although a potential association between PCV1 or PCV2 and CT-AII has been observed, about 50% CT cases described up till now are caused by unknown reasons. In a PCV-seropositive 108-sow, farrow-to-finish Belgian pig farm breeding hyperprolific Landrace, 42 litters with shaking piglet(s) were reported since June 2006. On March 2012, piglets born from four sows of a 27 sow batch demonstrated CT. After exclusion of main etiologies of CT from these CT-affected piglets, it was hypothesized that PCV1 or PCV2 could be the reason. Necropsies (n=8) and histopathology (n=3) were performed and no evidence of macroscopic or microscopic lesions were seen in cerebrum, cerebellum and spinal cord. Pre-suckled and post-suckled (after 3 days of colostrum uptake) serum samples were also collected from 9 piglets to determine PCV1- and PCV2-specific Ab titres by an immuno-peroxidase monolayer assay (IPMA). No PCV-specific Ab titres were observed in pre-suckled serum samples (≤40), whereas IPMA Ab titres of ≥640 were observed in post-suckled serum samples. Both PCV1 and PCV2 could not be isolated (<101.7 TCID50/g tissue) from 4 tested piglets (in heart, brain and lungs). The present results do not support the hypothesis that PCV1 or PCV2 are linked to CT in newborn piglets. [less ▲]

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See detailPrevalence of PRRS virus in Wallonia (Belgium)
Czaplicki, Guy; Thilmant, Pierre ULg; Hooyberghs, Josef et al

Poster (2013, May 22)

Porcine reproductive and respiratory syndrome (PRRS) causes major economical losses in pig farms. In different parts of the world, there is a growing consensus that PRRS virus (PRRSv) eradication should ... [more ▼]

Porcine reproductive and respiratory syndrome (PRRS) causes major economical losses in pig farms. In different parts of the world, there is a growing consensus that PRRS virus (PRRSv) eradication should be performed on a regional basis, particularly in low density areas of pig production. The objective of the present study was to evaluate the apparent prevalence of PRRSv in Wallonia, a low density area of pig production (0.05 pig farms/km²). At this stage of the study, a phone survey has been addressed to 61/276 Walloon breeding pig owners. Fifty-eight answered to the questionnaire: 51 are responsible of a farrow-to-finish farm, 6 of a farrowing farm and 1 of a PRRS-free boar station. In 35% of the tested farms, sows are vaccinated with a modified live virus (MLV) PRRS vaccine (n=11) or with a killed PRRS vaccine (n=9). In two farms, both sows and piglets are vaccinated with a MLV PRRS vaccine. Replacement gilts are purchased in 33% farms. Among the 38 farms raising replacement gilts, 39% purchase boar(s). Boar semen is purchased in 86% of the farms: 56% purchase only boar semen; 30% purchase both semen and boar(s) and 14% of farms only purchase boar(s). In 22/57 tested farms, clinical signs evocative of PRRSv infection were observed over the last 10 years. In 30 farms a PRRS diagnostic test was performed in the past with a positive result in 17. When the pig owner did agree and if no vaccination was carried out on sows or on piglets, a serological Elisa test was performed in 10 breeding pigs and/or 5 feeder pigs >70 kg (or in all available sera if a smaller number of pigs was present). Globally, at herd level and at animal level, the apparent prevalence were respectively 35.2% (95% CI: 23.0-47.4%) and 23.4% (95% CI: 20.1-26.6%). [less ▲]

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See detailApplication of three entomopathogenic fungi for aphid control
Bawin, Thomas ULg; Seye, Fawrou; Boukraa, Slimane ULg et al

Poster (2013, May 21)

Aphids (Homoptera: Aphididae) are sap-sucking insect pests that feed on several plants of agronomical importance. Chemical pesticide application is the most commonly used method for aphid control. Due to ... [more ▼]

Aphids (Homoptera: Aphididae) are sap-sucking insect pests that feed on several plants of agronomical importance. Chemical pesticide application is the most commonly used method for aphid control. Due to rapid developments of resistance to pesticides and environmental pollution, integrated pest management, including biological control was promoted. In this context, entomopathogenic fungi are valuable tools for potential aphid control since various fungal strains are already commercially available. The present study aims to evaluate and compare the insecticidal activity of two Metarhizium and one Aspergillus strains against Acyrthosiphon pisum aphid. Fungi were cultivated on wheat bran media in flasks up to sporulation. The solid media were washed with aqueous solutions containing 0.05% Tween 80 before filtration. The content of conidia was determined by haemocytometer. Doses ranging from 10^3 to 10^7 conidia/ml were then applied on young plants with 20 adult parthenogenetic aphids. Batches were incubated at a 16L/8D photoperiod, 25±2°C and 75-80% relative humidity. Adult mortality was assessed in order to determine LD50, LD90 and LT50 values, and the number of nymphs produced was daily recorded. Five days after treatment, mortality rates ranged from 30 to 91% depending on the fungal strain and tested dose. Corresponding LD50 and LD90 values were 1.23 x 10^3 and 1.34 x 10^7, 3.67 x 10^3 and 9.71 x 10^7, 4.95 x 10^2 and 5.65 x 10^7 conidia/ml for Metarhizium sp., Metarhizium anisopliae and Aspergillus clavatus respectively. At the higher dose, the LT50 were reached within 2, 4 and 3 days respectively, whereas the LT50 were never reached in the controls. By contrast, the intrinsic growth rates were significantly different from uninfected aphids only in the case of A. clavatus with 10^6 and 10^7 conidia/ml doses five days after exposure. In conclusion, these fungal isolates induced A. pisum mortality with a similar impact and A. clavatus infection appeared to alter the adults’ fitness. This suggests that these fungi may be candidates for aphid control. Further investigations should be made in order to assess their host range specificity. Toxic metabolites leading to death have to be identified and their safety towards non-target organisms confirmed. Finally, their persistence in the environment as well as the compatibility with over means of aphid control must be verified in a view of a broad integrated pest management. [less ▲]

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See detailLight-induced Hetero-Diels Alder cycloaddition as a new coupling method to biomolecule radiolabeling
Dammicco, Sylvestre ULg; Luxen, André ULg; Thonon, David et al

Poster (2013, May 16)

The formation of a C-18F bond requires hard conditions which is problematic for the biomolecule radiolabelling. The alternative method which has been developed since a few decades consists in ... [more ▼]

The formation of a C-18F bond requires hard conditions which is problematic for the biomolecule radiolabelling. The alternative method which has been developed since a few decades consists in incorporating the 18F on a prosthetic group and coupling it to the biomolecule. The copper (I)-catalysed 1,2,3-triazole formation involving azides and terminal alkynes is a powerful and rapid method of coupling but present the inconvenient of the employment of cytotoxic reagents. The photoclick conjugation is a promising alternative with no need of catalyst[1]. Recently, a light-induced hetero-Diels Alder cycloaddition involving a 3-(hydroxymethyl)-2-naphthol derivative and an electron-rich olefin has been developed[2]. This reaction seems well adapted for the fast conjugation of radionuclides to biomolecules. Herein we report the synthesis of a [18F]fluoronaphtoquinone derivative as prosthetic group and its reaction with vinyl ethers. [less ▲]

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See detailDust historical record in ombrotrophic peat: The case study of a NW European bog
Allan, Mouhamd ULg; Fagel, Nathalie ULg; Le Roux, Gael et al

Poster (2013, May 16)

Ombrotrophic peatlands are unique environmental archives of natural and anthropogenic atmospheric dust deposition because their surface layers are exclusively fed by atmospheric inputs. Lead (Pb) isotopes ... [more ▼]

Ombrotrophic peatlands are unique environmental archives of natural and anthropogenic atmospheric dust deposition because their surface layers are exclusively fed by atmospheric inputs. Lead (Pb) isotopes have been often used to evidence any anthropogenic influence in peat, but they only record trace metal pollution. Another radiogenic isotope, the Neodymium (Nd), could be also use to discriminate the sources of dust in peat bogs. Dust fluxes were investigated over the last 2500 years in the Misten peat bog in Eastern Belgium. Our aims were to use Nd isotope signature to decipher between local and distal dust supplies, the Pb isotopes to trace the antropogenic influences. To address these aims we analyzed REE and lithogenic element analyses, as well as the Nd and Pb isotopes, using HR-ICP-MS and MC-ICP-MS, respectively in peat layers dated by 210Pb and 14C. Changes in REE concentration variations in peat samples are correlated with Ti, Al, and Zr that are lithogenic conservative elements, suggesting that REE are immobile in the studied peat bogs and can be used as tracers of dust deposition. Dust fluxes show pronounced increase at BC300, AD600, 1000AD, 1200AD and from 1700AD, recording either influence of human activities (regional erosion due to forest clearing and soil cultivation activities) or local and regional climate changes. Lead enrichments reveal strong human impact over the last 300 years. Lead isotope signatures are consistent with local and regional contamination by coal combustion and smelting activities. Neodymium isotopes allow to identify three periods characterised by dominant-distal sources (at 320AD, 1000 AD and 1700AD). Those periods are consistent with local wetter intervals as indicated by lower humification degree. Local erosion prevails durier drier (higher humification) intervals (-100AD, 600AD). On a global scale more distal supplies are driven during colder periods, in particular Oort and Maunder minima, confirming the hypothesis that cold climate conditions favor distal supplies. Combining geochemical elementary content and isotope data in ombrotrophic peat allows to decipher between dust flux changes related to human and climate forcing. [less ▲]

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See detailDesign and development of new polyamides by ring-opening polymerization for high performance composite materials
Tunc, Deniz; Carlotti, Stéphane; Lecomte, Philippe ULg et al

Poster (2013, May 16)

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See detailMacroporous polyhipes from CO2-in-water emulsion templates stabilized by new sugar-based surfactants
Boyère, Cédric ULg; Favrelle, Audrey; Léonard, Alexandre F. et al

Poster (2013, May 16)

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See detailBiophysical characterization of the interaction of novel aromatic glycolipid surfactants with membrane models.
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Draguet, Florian et al

Poster (2013, May 15)

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic ... [more ▼]

Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral and anti-inflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit could also be useful to target specific cells. In this study, novel aromatic glycolipids were synthesized as useful models for studying the structure–activity relationship, in particular as a function of their aromatic group. Their interaction with membranes was studied with monolayer models and was predicted by a computational approach. The relationships between these data and their cytotoxicity and antioxidant properties evaluated on cell cultures are discussed. [less ▲]

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See detailMICROSTRUCTURAL AND PHYSICOCHEMICAL CHARACTERIZATION OF PALYGORSKITE CLAYS FROM MARRAKECH HIGH ATLAS, MOROCCO
El Boudour El Idrissi, Hicham ULg; Knidiri, Abdelouahab; Daoudi, Lahcen et al

Poster (2013, May 09)

The studied palygorskite clay mineral has been collected from several localities of Marrakech High Atlas Tertiary series. These series consist of alternation of marl, dolomite, limestone, gypsum and ... [more ▼]

The studied palygorskite clay mineral has been collected from several localities of Marrakech High Atlas Tertiary series. These series consist of alternation of marl, dolomite, limestone, gypsum and phosphatic beds. Palygorskite currently constitutes more than 90% of the clay fraction of these facies. The aim of this study is to characterise the structure and the physicochemical properties of these fibrous clays. Several technics were performed to characterise these clay sediments: X-ray diffraction (XRD) patterns to study its crystal structure. XRF analysis was performed to study the chemical compositions. Differential thermogravimetric analyses (DTA) were used to study the weight loss due to dehydration and dehydroxylation. The microstructure of these fibrous clays is determined by transmission and scanning electron microscop (TEM/SEM). Physical properties were characterised using the plasticity index of Casagrande, the test for shear strength and the oedometer test. The parameter concerning the adsorption capacity of methylene blue is also determined. The palygorskite clays of the Marrakech High Atlas consist of a silty clay of uniform appearance, greyish in color, and very low organic plastic. The thickness of deposit varies from several meters to several hundred meters. SEM and TEM observations show that palygorskite clay minerals display bundle of long fibres wish occurs as interwoven fibrous mats forming the laminae and as coatings and pore-filling, and pore-bridging cements in dolomite. These fibres are characterized by Mg rich chemical compositions, high crystalline structure, high specific surface area and excellent sorptive capacity. XRD show reflections (110) at 10.5 A, associated with all harmonics. The ATD curves show three endothermic peaks (100-200, 250-300 and 400-500 °C) corresponding to different dehydration process. A fourth exotherm peak often preceded by an endothermic reaction (800-900 °C) reflet the crystallization of new mineral phases including mullite. Palygorskite rich samples exhibit a high plasticity index of about 70. The swelling index generally increases with increasing content of palygorskite. In addition, Palygorskite rich samples exhibit high cohesion and a low friction angle. However, the density of the samples decreases with the increase of the content of palygorskite. [less ▲]

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See detailLES GISEMENTS D'ARGILES DE LA REGION DE MARRAKECH, MAROC
El Boudour El Idrissi, Hicham ULg; Daoudi, Lahcen; Fagel, Nathalie ULg

Poster (2013, May 08)

L'argile est une matière première abondante à la surface de la Terre. En raison de ces propriétés physico-chimiques, elle possède une grande variété d'utilisations. Le Maroc est l'un des plus grands ... [more ▼]

L'argile est une matière première abondante à la surface de la Terre. En raison de ces propriétés physico-chimiques, elle possède une grande variété d'utilisations. Le Maroc est l'un des plus grands consommateurs au monde d'argiles, cependant, le domaine majoritaire d’utilisation d’argiles est celui de la céramique. Dans la région de Marrakech, les argiles sont surtout utilisées dans les domaines de basse classe tels que la céramique traditionnelle et la poterie. Jusqu’à présent très peu d’études sont effectués pour valoriser ces argiles. C’est dans cet objectif que s’inscrit l’étude que nous menons sur les argiles du Haut Atlas de Marrakech ; le présent travail a pour objectif de dresser un inventaire des principaux gisements d’argiles de cette région. Les séries du Primaire (en particulier le Viséen) de la région de Marrakech ne sont pas assez altérées pour exploiter les argiles, tel est le cas de la région de Benhmed qui approvisionne les usines céramiques de la région de Settat. Dans les formations triasiques, malgré l'épaisseur et l'apparence argileuse des séries, seuls quelques gisements d'argiles y sont exploités pour la poterie. Les faciès triasiques, riches en illite, sont en effet silteux et assez pauvres en argiles à l'exception de quelques niveaux très minces. Ces argiles sont utilisées au niveau d’Ourika pour la fabrication d’ustensiles rustiques, pots de terre et objets ornementaux. Ces argiles peuvent également constituées des matières premières pour l’élaboration de briques et de substrats pour le revêtement des murs et des sols. Les argiles des formations jurassiques et crétacées sont assez riches en carbonates, ce qui ne convient pas à leur utilisation dans l’industrie céramique. Les séries du Paléocène et de l’Eocène de toute la région sont riches en argiles fibreuses non exploitées, surtout la palygorskite (argile avec de grandes propriétés physiques), ce qui donne des perspective d’utilisation dans des différents domaines industriels. Le Mioplicoène largement développé au pied du Haut Atlas est surtout connu par sa richesse en smectite, plus particulièrement dans la région de Tassaout. En ce qui concerne les séries quaternaires, certains niveaux d’alluvions sont exploités dans la région pour l’industrie céramique (site potier de Tamsloht, Briqueterie Menara,…). Dans la région de Bouchane, le sol quaternaire est considéré comme la seule source d’argiles et d’ustensiles dans cette zone. Enfin des dépôts actuels sont également exploités (limons des oueds Tensift et N’fis, canal la Rocade) pour la fabrication de briques de murailles ou additionnés à d’autres argiles pour augmenter la consistance des pâtes céramiques. [less ▲]

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See detailThe influence of biogeochemical processes on the pH dynamics in the seasonally hypoxic saline Lake Grevelingen, The Netherlands
Hagens, M; Slomp, C; Meysman, F et al

Poster (2013, May 07)

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See detailOverview of the geophysical data derived from long-term FTIR monitoring activities at the Jungfraujoch NDACC site (46.5ºN) and the PYGCHEM project
Mahieu, Emmanuel ULg; Bovy, Benoît ULg; Bader, Whitney ULg et al

Poster (2013, May 07)

We present an overview of the geophysical data deduced from long-term monitoring activities conducted at the Jungfraujoch station by the University of Liège. Typical results and trend investigations are ... [more ▼]

We present an overview of the geophysical data deduced from long-term monitoring activities conducted at the Jungfraujoch station by the University of Liège. Typical results and trend investigations are presented for hydrogen chloride (HCl) and carbonyl sulfide (OCS). We further display and briefly describe time series for new target gases, namely methanol (CH3OH) and HCFC-142b. We also show some preliminary results for ammonia (NH3) and peroxyacetyl nitrate (PAN). Finally, we present the PyGChem project, a Python interface to the GEOS-Chem model currently under development at ULg. [less ▲]

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See detailAnatase TiO2 colloidal nanocrystal-based architectures: models to assess the role of porosity and NCs morphology in Li battery electrode
Krins, Natacha ULg; Buonsanti, Raffaella; Kim, Chunjoong et al

Poster (2013, May 03)

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See detailUser-friendly method for GCxGC optimization
Stefanuto, Pierre-Hugues ULg; Dimandja, Jean-Marie; Focant, Jean-François ULg

Poster (2013, May)

Almost 30 years are gone since the first paper about multidimensional GC was published by John B. Phillips 1. After several years of developing process, Comprehensive Two Dimensional Gas Chromatography ... [more ▼]

Almost 30 years are gone since the first paper about multidimensional GC was published by John B. Phillips 1. After several years of developing process, Comprehensive Two Dimensional Gas Chromatography systems are in the commercialization step of its live time. During this period, the advantages of GC×GC, regarding to classical D1 system, were clearly demonstrated 2. However, the new parameters involve in a GC×GC method are still not completely understand and people don’t use it at the maximum of its capacity. According to the literature more and more group are using GC×GC for different kind of applications. In most of these researches, GC×GC was used for its separation power. Unfortunately, the orthogonality and the column set are most of the time poorly optimized. To help people in this important step, we develop an user-friendly method to choose the best column combination and the best separation parameters for a particular application. All these developments were based on different mix of standard call the Century mix and the Dimandja mix. These are the descendants of the Phillips mix create in 2003 by J. Dimandja 3. These mixtures contain homologous series of compounds representing the polarity and the volatility range commonly sees in GC×GC. This method is based on the Retention Index obtained in a classical GC analysis and projected in the 2D space. Using this projection method, we identified four major types of orthogonality based on the peak dispersion obtained. We name those: Normal, Reverse, Hybrid and Transpose orthogonality. To characterize these observations, we developed the Orthogonality Index. Going back to the mathematical definition of orthogonality, this factor is the angle formed between the alkane line and the aromatic hydrocarbon line in the chromatographic space. Using this predictive tool, people should be able to choose the best column set and to optimize easily the separation parameters. 1. Phillips, J.B., Luu, D., Pawliszyn, J.B. & Carle, G.C. Multiplex gas chromatography by thermal modulation of a fused silica capillary column. Anal. Chem. 57, 2779–2787 (1985). 2. Dimandja, J.-M.D. Comprehensive 2-D GC provides high-performance separations in terms of selectivity, sensitivity, speed, and structure. Anal. Chem. 76, 167A–174A (2004). 3. Dimandja, J., Clouden, G. & Colón, I. Standardized test mixture for the characterization of comprehensive two-dimensional gas chromatography columns: the Phillips mix. J Chromatogr a 1019, 261–272 (2003). [less ▲]

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See detailEtude tribologique sur des lubrifants solides à haute température
Legros, Arnaud ULg; Zaïdi, Hamid; Diny, Mouad et al

Poster (2013, May)

Actuellement, environ 2/3 de l’énergie libérée par la combustion de l’essence est rejetée sous forme de chaleur, soit dans les gaz d’échappement, soit dans le liquide de refroidissement. Un cycle de ... [more ▼]

Actuellement, environ 2/3 de l’énergie libérée par la combustion de l’essence est rejetée sous forme de chaleur, soit dans les gaz d’échappement, soit dans le liquide de refroidissement. Un cycle de Rankine peut être utilisé afin de valoriser la chaleur des gaz d’échappement. Cependant, aucune machine de détente commerciale n’est adaptée aux conditions de récupération d’énergie sur gaz d’échappement. La tribologie, plus particulièrement celle des lubrifiants solides à haute température, peut intervenir afin d’étudier les couples de matériaux adéquats pour réaliser les joints de la machine de détente du cycle. Cela permet de réduire les pertes globales de la machine et d’en améliorer le rendement. [less ▲]

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See detailQuality controls of no-carrier-added aromatic amino acids such as FDOPA and FTYR produced at curie level
Libert, Lionel ULg; Lemaire, Christian ULg; Giacomelli, Fabrice ULg et al

Poster (2013, May)

Aromatic fluoro amino acids such as 2-[18F]fluoro-L-tyrosine (FTYR) and 6-[18F]fluoro-L-DOPA (FDOPA) are useful radiopharmaceuticals for oncologic studies and evaluation of the presynaptic dopaminergic ... [more ▼]

Aromatic fluoro amino acids such as 2-[18F]fluoro-L-tyrosine (FTYR) and 6-[18F]fluoro-L-DOPA (FDOPA) are useful radiopharmaceuticals for oncologic studies and evaluation of the presynaptic dopaminergic function using positron emission tomography. Recently, a no-carrier-added (nca) enantioselective synthesis of these compounds, based on an multistep PTC approach was automated in a FASTlabTM module from GE . From 185 GBq of [18F]fluoride and after 1 hour of synthesis, more than 37 GBq of FTYR or FDOPA are available . This automated production yields enough doses for many PET studies. A monograph for FDOPA prepared by electrophilic substitution exists , but it is not adapted to the nca nucleophilic synthesis of FDOPA and FTYR, as in this case specific activity, by products and possible impurities are different. A complete quality control (QC) has then be developed in accordance with the guidelines of the European Pharmacopeia (Eur. Ph.). [less ▲]

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See detailAnalysis of mainstream tobacco smoke by SPME-GC×GC-TOFMS
Brokl, Michal ULg; Bishop, L; Wright, C et al

Poster (2013, May)

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See detailNON-ANTHOCYANIN POLYPHENOLS QUANTIFICATION IN EUTERPE OLERACEA FRUITS BY A UHPLC−LTQ-ORBITRAP MS METHOD
Dias, Aecio; Rozet, Eric ULg; Chataigné, G et al

Poster (2013, May)

High antioxidant and anti-inflammatory activities have been observed from non-anthocyanin polyphenols of E. oleracea fruits [1-2]. The aim of this work was to quantify major non-anthocyanin polyphenols by ... [more ▼]

High antioxidant and anti-inflammatory activities have been observed from non-anthocyanin polyphenols of E. oleracea fruits [1-2]. The aim of this work was to quantify major non-anthocyanin polyphenols by an accurate UHPLC−LTQ-Orbitrap MS method. Fruits were harvested in Pará state (Brazil), processed to pulp and lyophilised. 0.5g of dry pulp powder was defatted by sonication with petroleum ether. The residue was then extracted five times with 5mL MeOH each time for 30 min (optimized conditions giving recovery rates > 90%). The extract was evaporated to dryness with a RapidVap® evaporator at 35°C. Solubilization of the dried extract was realised using 40% MeOH. For the UHPLC quantification, a HSS C18 column (1.8µm) was used with a gradient elution of MeOH and H2O both with 0.1% HCOOH and the ionisation source (ESI) was operated in NI mode. 26 compounds were identified, among them 7 identified for the first time in this fruit. Total error and accuracy profiles were used as validation criteria. Calibration in the matrix was found to be more accurate than calibration without matrix. Trueness, repeatability, intermediate precision, selectivity, response function, linearity and LOD/LOQ for 12 non-anthocyanin phenolic compounds were evaluated and the quantification method validated. [1] J. Kang et al., Food Chem. 122 (2010) 610–617. [2] J. Kang et al., Food Chem. 128 (2011) 152–157. [less ▲]

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See detailThermal adaptation of the ribosomal chaperone trigger factor
Godin, Amandine ULg; Schmidpeter, Phillip; Schmid, Franz et al

Poster (2013, May)

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See detailHuman papillomavirus entry into NK cells requires CD16 expression and triggers cytotoxic activity and cytokine secretion
Renoux, Virginie; Bisig, Bettina; Langers, Inge ULg et al

Poster (2013, May)

Human papillomavirus (HPV) infections account for more than 50% of infection-linked cancers in women worldwide. The immune system controls, at least partially, viral infection and around 90% of HPV ... [more ▼]

Human papillomavirus (HPV) infections account for more than 50% of infection-linked cancers in women worldwide. The immune system controls, at least partially, viral infection and around 90% of HPV-infected women clear the virus within two years. However, it remains unclear which immune cells are implicated in this process and no study has evaluated the direct interaction between HPVs and NK cells, a key player in host resistance to viruses and tumors. We demonstrated an NK-cell infiltration in HPV- associated preneoplastic cervical lesions. Since HPVs cannot grow in vitro, virus-like particles (VLPs) were used as a model for studying the NK-cell response against the virus. Interestingly, NK cells displayed higher cytotoxic activity and cytokine production (TNF-a and IFN-g) in the presence of HPV-VLPs. Using flow cytometry and microscopy, we observed that NK-cell stimulation was linked to rapid VLP entry into these cells by macropinocytosis. Using CD16+ and CD16- NK-cell lines and a CD16-blocking antibody, we demonstrated that CD16 is necessary for HPV–VLP internalization, as well as for degranulation and cytokine production. Thus, we show for the first time that NK cells interact with HPVs and can participate in the immune response against HPV-induced lesions. [less ▲]

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See detailInvestigation on human cadaveric VOC by TD-GCxGC-TOFMS
Stefanuto, Pierre-Hugues ULg; Stadler, Sonja; Pesesse, Romain et al

Poster (2013, May)

The study of the ‘smell of death’ is a challenging task. Analytical chemists who try to understand human decomposition are facing very complex mixtures of analytes present at various levels. For the last ... [more ▼]

The study of the ‘smell of death’ is a challenging task. Analytical chemists who try to understand human decomposition are facing very complex mixtures of analytes present at various levels. For the last few decades, investigations have been conducted to better learn the process of body decomposition by mean of the measurement of the Volatile Organic Compounds (VOCs) released during decay1. However, the chemical profile of the decomposition odor is still far from being elucidated. Indeed, the complexity of the VOC mixtures makes this profiling difficult to be carried out by a classical gas chromatography mass spectrometry (GC-MS) approach. In previous studies, we developed direct-sampling based approaches for cadaveric VOC analysis from grave soils and decaying bodies by mean of thermal desorption (TD) coupled to comprehensive two-dimensional GC coupled to time-of-flight MS (GC×GC-TOFMS)2,3,4. They were based on the use of human analogs (Sus domesticus L. carcasses). For the present study, we investigated the VOC profile of early stage decomposition of human bodies. We analyzed samples collected during different trials organized during different seasons in a body farm located in Texas. Samples included environmental controls, pig carcasses, and human bodies (protected or not from scavenger insects). The data processing was performed in the light of identifying possible seasonal and species variations. Both peak capacity enhancement and spectral deconvolution helped to characterize VOC mixtures and improve comparisons of profiles. Acknowledgements: Human samples were collected during the project “Development and validation of standard operating procedures for measuring microbial populations for estimating a post-mortem interval” Grant Award No. 2010-DN-BX-K243. The authors of that grant are acknowledged for giving us the opportunity to access cadavers for sampling. 1. Vass, A.A. et al. Decompositional odor analysis database. J Forensic Sci (2004) 49, 1–10. 2. Brasseur C. et al. Comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry for the forensic study of cadaveric volatile organic compounds released in soil by buried decaying pig carcasses. J Chromatogr A (2012) 1255, 163–170. 3. Dekeirsschieter, J. et al. Enhanced characterization of the smell of death by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOFMS). PLoS ONE (2012) 7, e39005. 4. Stadler, S. Characterization of volatile organic compounds from human analogue decomposition using thermal desorption coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. Anal Chem (2013) 85, 998–1005. [less ▲]

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See detailTowards a Standards-Based Cloud Service Manager
Ghrab, Amine; Skhiri, Sabri; Koener, Hervé et al

Poster (2013, May)

Migrating services to the cloud brings all the benefits of elasticity, scalability and cost-cutting. However, migrating services among different cloud infrastructures or outside of the cloud is not an ... [more ▼]

Migrating services to the cloud brings all the benefits of elasticity, scalability and cost-cutting. However, migrating services among different cloud infrastructures or outside of the cloud is not an obvious task. In addition, distributing services among multiple cloud providers, or on a hybrid installation requires a custom implementation effort that must be repeated at each infrastructure change. This situation raises the lock-in problem and discourages cloud adoption. Cloud computing open standards were designed to face this situation and to bring interoperability and portability to cloud environments. However, they target isolated resources, and do not take into account the notion of complete services. In this paper, we introduce an extension to OCCI, a cloud computing open standard, in order to support complete service definition and management automation. We support this proposal with an open-source framework for service management through compliant cloud infrastructures. [less ▲]

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See detailBiogeochemistry and carbon mass balance of a coccolithophore bloom in the northern Bay of Biscay (June 2006)
Harlay, Jérôme ULg; Chou, Lei; Van Oostende, Nicolas et al

Poster (2013, May)

Primary production (PP), calcification (CAL), bacterial production (BP) and dark community respiration (DCR) were measured along with a set of various biogeochemical variables, in early June 2006, at ... [more ▼]

Primary production (PP), calcification (CAL), bacterial production (BP) and dark community respiration (DCR) were measured along with a set of various biogeochemical variables, in early June 2006, at several stations at the shelf break of the northern Bay of Biscay. The cruise was carried out after the main spring diatom bloom that, based on the analysis of a time-series of remotely sensed chlorophyll-a (Chl-a), peaked in mid-April. Remotely sensed sea surface temperature (SST) indicated the occurrence of enhanced vertical mixing (due to internal tides) at the continental slope, while adjacent waters on the continental shelf were stratified, as confirmed by vertical profiles of temperature acquired during the cruise. The surface layer of the stratified water masses (on the continental shelf) was depleted of inorganic nutrients. Dissolved silicate (DSi) levels probably did not allow significant diatom development. We hypothesize that mixing at the continental slope allowed the injection of inorganic nutrients that triggered the blooming of mixed phytoplanktonic communities dominated by coccolithophores (Emiliania huxleyi) that were favoured with regards to diatoms due to the low DSi levels. Based on this conceptual frame, we used an indicator of vertical stratification to classify the different sampled stations, and to reconstruct the possible evolution of the bloom from the onset at the continental slope (triggered by vertical mixing) through its development as the water mass was advected on-shelf and stratified. We also established a carbon mass balance at each station by integrating in the photic layer PP, CAL and DCR. This allowed computation at each station of the contribution of PP, CAL and DCR to CO2 fluxes in the photic layer, and how they changed from one station to another along the sequence of bloom development (as traced by the stratification indicator). This also showed a shift from net autotrophy to net heterotrophy as the water mass aged (stratified), and suggested the importance of extracellular production of carbon to sustain the bacterial demand in the photic and aphotic layers. [less ▲]

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See detailYouth leaders’ representations about the role of youth organizations in physical activity promotion
Cloes, Marc ULg; Wilkin, Sophie

Poster (2013, May)

Purpose. Multisectorial actions are needed to fight against sedentariness. Youth organizations (YO) gather thousands of children and adolescents each weekend. Most of them propose to develop all ... [more ▼]

Purpose. Multisectorial actions are needed to fight against sedentariness. Youth organizations (YO) gather thousands of children and adolescents each weekend. Most of them propose to develop all dimensions of the individuals and to contribute to the education of the youth. Unfortunately, very few studies are available to confirm if this is the case. The purpose of this study was to determine if the youth leaders consider that they play a role in physical activity (PA) promotion. Methods. A questionnaire was developed and tested by a pilot study. It comprised four parts (Introduction, Descriptive variables; Youth leader’s representations about PA; Youth leader’s representations about the role of the YO in PA promotion). Most of the questions were Lickert scales. Answers of 232 youth leaders were analysed. They were belonging to all youth movements of the Liege area. Results. Youth leaders tended to support the idea that YO have to play a role in PA promotion: 57.3% totally agree on the fact that YO allows youth to be physically active; 40.1% consider that it is effectively the case. On the other hand, only 1.3% believes that their group attend to sports during YO’s activities and 4.7% that youth use what they learn about PA in YO in their everyday life. Conclusions This study emphasized that YO should be more involved as an determining actor in the overall PA promotion and that youth leaders should be more systematically informed and prepared about the potential role that they could play. [less ▲]

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See detailLuminescence dating of the Palaeolithic site of Kulbulak (Uzbekistan) using IR50 and pIRIR290 signals from K-feldspar
Vandenberghe, Dimitri; Van Nieuland, J.; De Dapper, Morgan et al

Poster (2013, May)

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See detailWhat are the barriers encountered by the physiotherapists in their role of physical activity promoters?
Cloes, Marc ULg; Fabre, Florian

Poster (2013, May)

Purpose. The fight against sedentariness needs multisectorial actions. Being experts in movement and exercise, physiotherapists (PT) consider themselves as ideally placed to promote, guide and prescribe ... [more ▼]

Purpose. The fight against sedentariness needs multisectorial actions. Being experts in movement and exercise, physiotherapists (PT) consider themselves as ideally placed to promote, guide and prescribe physical activity (PA). The purpose of this study was to identify the barriers that limit their PA promoting mission as well as proposals of solutions. Methods. Fifteen PT attended to a 3 hours meeting during which researchers applied the nominal group technique. After a short introduction summarizing basic notions about PA, subjects were invited to describe the problems that PTs encountered when they want to promote PA. In a second step, they selected 8 categories of barriers to be discussed. During the last part of the meeting, subgroups had to imagine solutions to deal with selected problems. Oral reports were shared. After the meeting, a written report was prepared by the researchers and validated by the subjects. Results. Out of the 13 identified categories, subject selected the following: Patients’ lack of awareness of PA’s interest for healthy living; Patients’ poor self perceptions and misrepresentations about PA; Patients’ difficulties to change their behaviour; PTs’ lack of knowledge about PA; PTs’ lack of informational resources; Patients’ lack of social support; Patients’ lack of facilities; PTs’ lack of interaction with other actors. The synthesis of the solutions was combined with written resources in a 19 pages brochure. Conclusions. This study pointed out that PTs are able to propose a plurality of ideas and approaches through a constructive group work. Such approach will be proposed in inservice education. [less ▲]

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See detailSelection of a spatial hypothesis in geographic profiling using graph theory
Trotta, Marie ULg

Poster (2013, May)

Geographic profiling is based on the spatial hypothesis of a distance decay effect around the offender’s anchor point and can be very useful for delineating prior search areas for individual ... [more ▼]

Geographic profiling is based on the spatial hypothesis of a distance decay effect around the offender’s anchor point and can be very useful for delineating prior search areas for individual investigations such as DNA testing. However, this spatial hypothesis fails to model a significant part of Belgian serial sexual offenders. In previous study, a complementary hypothesis, the minimisation of the variance (MOV) for the distances between the offender’s anchor point and the crime site, exploiting recent literature observation, is proposed to model unexplained behaviours. A systematic comparison of the distance decay and the MOV hypotheses show that their overall capacities to provide an effective geoprofile are similar, but their performances may differ, depending on the geometric pattern of crimes. Here, we use graph theory to describe the favourable patterns for the MOV, in order to select which spatial hypothesis is best suited for a new investigation. While star graphs represent patterns for which both hypotheses could be validated, wheels with preferred directions are only explained by the MOV hypothesis. Real patterns on the road network are a-posteriori evaluated thanks to the generation of the shortest path between the best solution of the MOV and all the crime locations thanks to the Dijkstra algorithm. [less ▲]

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See detailWhich characteristics for an internet-delivered intervention to promote physical activity? Opinions and usages of older adults
Rompen, Jérôme ULg; Mouton, Alexandre ULg; Cloes, Marc ULg

Poster (2013, May)

Purpose. Developing, in a Belgian French-speaking community, an internet-based intervention to promote physical activity among adults over 50 years old. Determining which mediators of this intervention ... [more ▼]

Purpose. Developing, in a Belgian French-speaking community, an internet-based intervention to promote physical activity among adults over 50 years old. Determining which mediators of this intervention are the most used by participants and which mediators are the most useful to improve their physical activity level. Methods. At baseline, 87 older adults (60.69 ± 7.85 years) from the same district were assigned to two groups that have received the intervention. This intervention comprised a comprehensive physical activity promotion website, with an emphasis on neighbourhood environment contents, and a monthly personalized e-mail based on the stages of change theory. Assessment tools included a post-satisfaction questionnaire and the measure of the number of visits of each page of the website. Results. According to participants, all parts of the intervention were useful. Indeed, all components received a score above 3/6. The most useful parts of the website, according to participants, were the following topics: “Hiking trails maps” (4.46/6), “Set your goals” (4.14/6) and “Tips for beginning” (4.1/6). The most consulted pages of the website were the pages “My activity log” (163), “News” (137) and “Activity programs examples” (114). Conclusions. In future actions, all parts of this intervention could be preserved. However, some elements could be added, like an online forum or regular sessions of physical activity with a coach. [less ▲]

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See detailThe contribution of Multidimensional IRT for modeling applicants performance on a SJT.
Lothe, Benoit ULg; Monseur, Christian ULg; Hansez, Isabelle ULg

Poster (2013, May)

Situational judgment tests (SJTs) are testing methods often used in Personnel Selection to appraise different constructs (Whetzel & McDaniel, 2009). In the framework of an overall career progression ... [more ▼]

Situational judgment tests (SJTs) are testing methods often used in Personnel Selection to appraise different constructs (Whetzel & McDaniel, 2009). In the framework of an overall career progression program in a Public Administration, SJTs were developed to assess several competencies relevant to both task (e.g. planning, managing, etc.) and contextual performance (e.g. helping behaviour, organizational loyalty, etc.). Each competency is a combination of KSAOs needed to perform efficiently in a specific context (Campion & al., 2012; Le Boterf 2008). Given the lack of internal consistency of SJT and the dichotomous nature of the data, we decide to use Multidimensional Item Response Theory (MIRT) model to examine the issue of construct validity. Based on Hartig & Höhler (2009), we use MIRT compensatory model to estimate the latent covariance structures of the SJT. Different model are tested and compared depending on the number of dimension involved, the nature of the items and latent variables relation (between or within-item multidimensionality) and the number of model parameter (one or two parameter model). The results and findings lead us to discuss some implications (gaining accuracy, modeling performance in complex task, etc.) and limitations (dealing with complex loading structure, etc.) of using IRT, over and above classical test theory, in the specific case of SJTs applicants performance. The originality of this communication also lies in the way we addressed SJTs reliability and construct validity issues with a measurement based model that differs from the one usually used in the field. [less ▲]

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See detailWhat is proposed to overweight and obese youth in a sample of fitness centres?
Cloes, Marc ULg; LEBRETHON, Marie-Christine ULg; Fortemps, Grégory

Poster (2013, May)

Purpose. Overweight and obesity take a growing place in the public health preoccupations as the proportion of people over the normal BMI limit increases dramatically year after year. This evolution could ... [more ▼]

Purpose. Overweight and obesity take a growing place in the public health preoccupations as the proportion of people over the normal BMI limit increases dramatically year after year. This evolution could have devastating consequences on the economy for years and possibly generations to come. Youth physical activity is pointed out as a priority. Fitness centres are possible partners of health services. This study aimed to know if overweight/obese youth could be welcomed into a sample of fitness centres. Methods. A sample of 13 fitness centres of the Liege area was visited. Fourteen interviews with the managers have been conducted. Specific questions were asked about what is proposed to overweight and obese people and specifically to youth group. Content analysis has been done from verbatim transcripts. Results. Most of the subjects consider that overweight/obese youth could encounter some difficulties to adhere to a fitness centre. Unfounded embarrassment about the look of others is underlined by 7 out of the managers. The real intrinsic motivation of the youth would be a key factor as well as real difficulties to use the equipment. Few fitness centres currently propose specific activities but 7 would be ready to collaborate with a medical unit in order to propose specific activities. Two decided to stop such initiatives according to the cost and lack of perseverance of the youth. Conclusions. This study showed that fitness centres managers would be interested to implement initiatives to offer specific services to overweight/obese youth but it would require collaboration with health services. [less ▲]

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See detailStudy on the sensitivity of three oat varieties to the saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae)
Censier, Florence ULg; Chavalle, Sandrine; San Martin y Gomez, Gilles et al

Poster (2013, May)

Saddle gall midge, Haplodiplosis marginata (von Roser) is a univoltine pest of cereals which occurs in Europe. The larvae overwinter in the soil. During the spring, the new emerged females lay eggs on the ... [more ▼]

Saddle gall midge, Haplodiplosis marginata (von Roser) is a univoltine pest of cereals which occurs in Europe. The larvae overwinter in the soil. During the spring, the new emerged females lay eggs on the leaves of cereals and grasses. After hatching, larvae migrate under the leaf sheath, where they develop at the expense of the plant. As a reaction, stems induce saddle-shaped galls of 5 to 10 mm long. Numerous galls can lead to stem breaks and important yield losses when they are numerous. After 40 years without any reporting, large populations of H. marginata and important damage have been observed since 2010 in wheat crops in Belgium, especially in the Flemish Polders where clay soils and intensive farming of cereals favour heavy infestations. According to some research conducted in the 60s during the last outbreak, oat (Avena sativa L.) is known to be one of the less attractive hosts to the saddle gall midge. Our study was thus performed in order to assess the host sensitivity of three oat varieties currently grown in Belgium (Evita, Effektiv and Freddy). Therefore, oat varieties were sown on infested ground in two separate enclosures in a glasshouse. In the first enclosure, only the three oat varieties were grown ; in the second one, these three oat varieties were grown together with two varieties of spring wheat (Granny and KWS Chamsin). Two parameters were measured: the percentage of leaves with laid eggs, and the number of galls per stem. The percentage of leaves with eggs showed that the infestation is significantly lower on oats when they are in presence of wheat. The infestation was also significantly higher on wheat than on oat, which means oat is a much less favoured host plant than spring wheat for laying. Oat varieties were significantly different regarding the number of galls per stem, but with very little damage compared to wheat. The Freddy variety even seemed to be completely resistant to saddle gall midge, as no galls were observed although there were a similar percentage of leaves with eggs for the three oat varieties. Cropping oat could thus contribute to reduce or even to eliminate infestations of H. marginata. [less ▲]

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See detailPhysical activity promotion among older adults: Short term effects of a neighbourhood environment internet-based intervention
Mouton, Alexandre ULg; Rompen, Jérôme ULg; Cloes, Marc ULg

Poster (2013, May)

Purpose. Recent research suggests that internet-based physical activity interventions can be suitable and effective, even for older adults. Besides, neighbourhood environment internet-based interventions ... [more ▼]

Purpose. Recent research suggests that internet-based physical activity interventions can be suitable and effective, even for older adults. Besides, neighbourhood environment internet-based interventions are currently considered as more effective than traditional motivational interventions. Therefore, the main purpose of this study was to explore the effects of a neighbourhood environment internet-based intervention on physical activity behaviours of older adults. Methods. At baseline, 87 older adults (60.69 ± 7.85 years) from the same district were assigned to an intervention (n = 41) or a control (n = 46) group. The two months intervention was composed of a comprehensive physical activity promotion website, with an emphasis on neighbourhood environment contents, and a monthly personalized email based on the stage of change theory. Physical activity behaviours were assessed by the IPAQ short-form and the stage of change questionnaire at baseline, after one and two month of the intervention, and after one month follow-up. Results. Significant improvements were observed for the stage of change questionnaire in the intervention group from baseline to the end of the intervention (p = 0.003), they remained at follow-up (p = 0.012) while the control group remained unchanged. Physical activity level declined progressively in the control group as it remained constant in the intervention group, with as significant difference between groups after two months intervention (p = 0.027). Conclusions. These findings suggest that a neighbourhood environment internet-based intervention can improve physical activity behaviours in older adults. Further research on this topic is needed to examine longer term effects with larger sample. [less ▲]

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See detailKnowledge about physical activity among older adults: Short term effects of a neighbourhood environment internet-based intervention
Mouton, Alexandre ULg; Rompen, Jérôme ULg; Cloes, Marc ULg

Poster (2013, May)

Purpose. Despite the numerous health benefits, population physical activity levels are low and decline with age. Few studies exposed that a better knowledge about physical activity could encourage people ... [more ▼]

Purpose. Despite the numerous health benefits, population physical activity levels are low and decline with age. Few studies exposed that a better knowledge about physical activity could encourage people to become physically active, which constitute a critical health challenge for older people. Moreover, neighbourhood environment internet-based interventions are recommended to promote physical activity. Therefore, the main purpose of this study was to explore the effects of a neighbourhood environment internet-based intervention on knowledge about physical activity among older adults. Methods. At baseline, 87 older adults (60.69 ± 7.85 years) from the same district were assigned to an intervention (n = 41) or a control (n = 46) group. The two months intervention was composed of a comprehensive physical activity promotion website, with an emphasis on neighbourhood environment contents, and a monthly personalized email based on the stage of change theory. Physical activity knowledge was assessed by questionnaires at baseline, after one and two month of the intervention, and after one month follow-up. Results. After the intervention, knowledge of the physical activity recommendations significantly improved in the intervention group (p = 0.032), while the control group remained unchanged. Besides, knowledge about environmental opportunities for physical activity increased slightly only in the intervention group. Conclusions. These findings suggest that a neighbourhood environment internet-based intervention can result in modest improvements of the physical activity knowledge in older adults. Further research should focus on alternative ways to improve the knowledge about local opportunities for physical activity and its relationship with long term effects on behaviour change. [less ▲]

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See detailLe référentiel "quartiers durables"
Marique, Anne-Françoise ULg; Loiseau, Véronique ULg; Godard, Florence et al

Poster (2013, April 30)

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See detailThe TRAPPIST survey of southern transiting planets – Physical properties of the WASP-36 planetary system
Delrez, Laetitia ULg; Gillon, Michaël ULg; Jehin, Emmanuel ULg et al

Poster (2013, April 29)

We present ten new transit light curves obtained with the TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) and Euler telescopes for the recently discovered planetary system WASP-36 (Smith ... [more ▼]

We present ten new transit light curves obtained with the TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) and Euler telescopes for the recently discovered planetary system WASP-36 (Smith et al. 2012). Thanks to this extensive data set, we are able to confirm and improve the parameters of the system. WASP-36 is a solar-mass G2 dwarf which hosts a giant planet on a 1.54 d orbit. With a mass of ~2.3 MJup and a radius of ~1.3 RJup, this planet is slightly denser than Jupiter. One of the most interesting properties of the system is its low stellar metallicity ([Fe/H] =-0.26+-0.10), as giant planets are actually known to be rare around such stars (e.g. Fischer & Valenti 2005). Furthermore, due to its small orbital distance and large radius, WASP-36b is an exquisite target for spectrophotometric emission measurements able to constrain the thermal and chemical properties of its atmosphere. [less ▲]

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See detailA comparative Genome-Wide Association Interaction study using BOOST and MB-MDR algorithms on Ankylosing Spondylitis
Bessonov, Kyrylo ULg

Poster (2013, April 29)

Genome-Wide Association (GWA) studies have gained popularity after the completion of the Human Genome Project and advancement of high-throughput technologies. These studies aim to scan thousands of ... [more ▼]

Genome-Wide Association (GWA) studies have gained popularity after the completion of the Human Genome Project and advancement of high-throughput technologies. These studies aim to scan thousands of genomic variations (e.g., SNPs) for their association to phenotypic variables (i.e. traits), such as disease related phenotypes, with the hope of extracting biologically and clinically relevant information. Understanding of genetic, environmental as well as other components of the disease brings the key insights into disease pathology and approaches us closer to the ultimate goal - personalized medicine. In this work we rely on a minimal GWAI protocol for genome-wide epistasis detection using SNPs, as developed in our lab [6][9]. Using the advanced non-parametric Model-Based Multifactor Dimensionality Reduction (MB-MDR) method [1] and BOolean Operation-based Screening and Testing (BOOST) algorithms [4][*] for detection of statistically significant epistatic SNP-SNP interactions, we investigate the effect of exhaustive (BOOST) and non-exhaustive (MB-MDR) marker processing strategies, LD effects, as well as different adjustment schemes for lower-order effects (i.e. epistasis). Our approach was tested on Ankylosing Spondylitis (AS) data as provided by the WTCCC2 consortium [1]. AS is a long-term / chronic disease characterized by inflammation of the joints between the spinal bones. Non-steroidal anti-inflammatory drugs calming down the immune system inflammatory responses are used as a treatment but there is no permanent cure for AS. The disease has also a strong environmental component and affects 3.5 - 13 per 1,000 people in USA [5] [less ▲]

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See detailPuff pastry margarines performances related to their physicochemical properties
Lefebure, Emilie ULg; Cavillot, Valérie; Blecker, Christophe ULg et al

Poster (2013, April 28)

Detailed reference viewed: 17 (3 ULg)
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See detailModeling simple lipid phase separation and effects of amphiphilic molecules on lipid domains
Lins, Laurence ULg; Deleu, Magali ULg; Mingeot-Leclercq, Marie-Paule et al

Poster (2013, April 28)

Detailed reference viewed: 15 (3 ULg)
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See detailComparison of Real-Time Aspergillus PCR with Platelia™AspergillusEIA in broncho-alveolar lavage fluids for the diagnosis of invasive aspergillosis in neutropenic and non-neutropenic patients
RUZICKA, NADIA; BOREUX, Raphaël ULg; LEVAUX, Laetitia ULg et al

Poster (2013, April 27)

Objectives. Because of low sensitivity of fungal cultures and lack of standardization of Aspergillus PCR, laboratory diagnosis of invasive aspergillosis still relies on galactomannan (GM) detection in ... [more ▼]

Objectives. Because of low sensitivity of fungal cultures and lack of standardization of Aspergillus PCR, laboratory diagnosis of invasive aspergillosis still relies on galactomannan (GM) detection in broncho-alveolar lavage (BAL) fluids and serum. The aim of this study was double: first, to assess the place of a 18S rRNA Aspergillus real-time PCR test performed in BAL fluid for the diagnosis of invasive aspergillosis (IA) in neutro- and non-neutropenic patients in comparison with GM detection; secondly, to evaluate the use of three different GM cut-off values. Materials and methods. A total of 111 neutropenic and non-neutropenic patients hospitalized at the University hospital of Liège from March to October 2012 with suspicion of IA were included in the study. A total of 138 broncho-alveolar lavage fluids were evaluated by three laboratory diagnostic methods: 1/ culture on Sabouraud agar slants with antibiotics (bioMérieux, France) incubated at 28°C for 28 days; 2/ GM detection (Platelia ™Aspergillus EIA, Biorad) using GM index cut-off values at 0.5, 0.8 and 1, performed three times a week; 3/ a real-time Aspergillus PCR assay performed daily and targeting the 18S rRNA genes by using an in-house method. Clinical, radiological and microbiological data were reviewed for classification of patients. Results. Nine patients developed probable or possible IA. The sensitivity/specificity/positive (VPP) and negative (NPV) predictive values (%) for culture, PCR, and GM using 0,5 as cut-off value were respectively 41/100/100/94, 58/97/70/96, and 91/83/34/99. The use of 0,8 and 1 as GM index cut-off values increased the specificity to 89 and 92% respectively, and the VPP to 44 and 54%. PCR had a better turn-around time and allowed the detection of Aspergillus colonisation. Conclusion: GM detection in BAL fluids using a cut-off value of 1 was the most efficient laboratory test for the diagnosis of IA in neutropenic and non-neutropenic patients. Despite a lower sensitivity, PCR had a better VPP, and allowed the detection of culture-negative Aspergillus colonisations. A shorter turnaround time (TAT) due to daily practice of PCR tests may reduce the time-to-treatment up to 24 hours. [less ▲]

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See detailIntraocular lenses with functionalized surfaces by biomolecules in relation with lens epithelial cell adhesion
Huang, Yi-Shiang ULg; Alexandre, Michaël ULg; Bozukova, Dimitriya et al

Poster (2013, April 25)

A cataract is pathology opacity of the lens or capsule of the eye, causing impairment of vision or even blindness. Surgery, with lens extraction and intraocular lens implantation, is still the only ... [more ▼]

A cataract is pathology opacity of the lens or capsule of the eye, causing impairment of vision or even blindness. Surgery, with lens extraction and intraocular lens implantation, is still the only currently available treatment. The most common complication after implantation of intraocular lenses (IOLs) is the posterior capsular opacification (PCO) or secondary cataract. This is the result of lens epithelial cells (LECs) proliferation and their transition to mesenchymal cells. In 1997, a Sandwich theory was proposed to elucidate the developmental process of PCO. [1] According to this model, an IOL with higher affinity to LECs will induce a less PCO. In our research, the pHEMA (Poly(2-hydroxyethyl methacrylate)) based acrylic hydrophilic polymer is subjected to the surface modification by conjugating with the bioactive peptides. The RGD sequence, known for its excellent biocompatibility, is designed to stimulate the biointegration between the LECs and the polymer implant. [2]. From our research, The RGD peptide immobilized onto pHEMA surfaces significantly facilitates the adhesion of the porcine LEC. The peptide immobilized surface retains its biological function even after 10 times of autoclave. On the other hand, the immobilized peptide does not alter the hydrophobicity of the surface, the light transmission, as well as the cytotoxicity of the material. This functionalized biomaterial would possibly prevent the formation of PCO. [1] J Cataract Refract Surg. 1997 Dec;23(10):1539-42 [2] Trends Biotechnol. 2008 Jul;26(7):382-92 [less ▲]

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See detailUse of supercritical carbon dioxide to elaborate drug-loaded polymeric implants
Champeau, Mathilde; Thomassin, Jean-Michel ULg; Jérôme, Christine ULg et al

Poster (2013, April 25)

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See detailReturn-To-Play criteria after hamstring injury: actual medicine practice in professional soccer
Delvaux, François ULg; Rochcongar, Pierre; Bruyère, Olivier ULg et al

Poster (2013, April 25)

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See detailTime variyng groundwater flux measurement using a single well tracer technique
Jamin, Pierre ULg; Brouyère, Serge ULg; Bour, Olivier et al

Poster (2013, April 24)

Contaminant mass discharge measurements are often performed at given times or integrated over a certain period of time, using active or passive sampling techniques. One problem arising is that such ... [more ▼]

Contaminant mass discharge measurements are often performed at given times or integrated over a certain period of time, using active or passive sampling techniques. One problem arising is that such measurements may not be representative of the temporal dynamics of the mass discharge variations. These variations can be caused by fluctuations in contaminant concentrations or, more frequently, by changes in the groundwater fluxes. Pollutant mass fluxes are typically estimated through a combination of solute concentrations and groundwater fluxes measured across a control plane made of several multi-level wells. Accurate measurements of local transient Darcy fluxes have been recognized as the weakest points in most of the developed techniques for groundwater contaminant mass flux measurements. The main objective here is to extend the FVPDM technique for temporal monitoring of groundwater fluxes and to demonstrate its ability to be used in combination with passive sampling devices for measurement of contaminant mass fluxes in groundwater. The Finite Volume Point Dilution Method (FVPDM) is a single well tracer technique for the measurement of local groundwater fluxes based on the continuous injection of tracer at very low injection rate (Brouyère et al. 2008). These developments are based on the application of the adapted technique on a case study in a fractured granitic aquifer in Ploemeur (France). This application investigates transient groundwater fluxes that are controlled by pumping in a well nearby the tested piezometers. Long monitoring time series have been recorded under these controlled conditions of transient groundwater flow. Results show the high sensivity of the FVPDM technique to small variations in groundwater flow velocities and its aptitude for long term monitoring of groundwater fluxes. The comparison between the results of FVPDM and classical point dilution tests performed in same conditions shows close correlation. Interpretation of FVPDM tests in transient conditions have been developed together with an evaluation of the uncertainties that can happen if the frequency of the groundwater flow variations is high. The tests carried on the Ploemeur site also illustrate the first ever application of the FVPDM technique between a double-packer system used for the investigation of a defined layer of an aquifer. This innovative application of the FVPDM using packers opens concrete perspectives for investigation of vertical heterogeneities of groundwater fluxes across a well. [less ▲]

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See detailCFD Modelisation of homogeneous distribution of solid particles in a stirred tank
Calvo, Sébastien ULg; Delafosse, Angélique ULg; Collignon, Marie-Laure ULg et al

Poster (2013, April 24)

In this work, we study the conditions needed to reach homogeneous distribution of solid particles of aluminium salts in water inside a torospherical bottom shaped stirred tank reactor of 70L equipped with ... [more ▼]

In this work, we study the conditions needed to reach homogeneous distribution of solid particles of aluminium salts in water inside a torospherical bottom shaped stirred tank reactor of 70L equipped with a Pfaudler RCI type impeller and three equi-spaced vertical baffles. The aim of the present study is to develop a CFD model describing the quality of particle distribution in industrial scale tanks. This model, validated with experimental data, is afterward used to developed scale-up and scale-down correlations to predict the minimum impeller speed needed to reach homogeneous solid distribution Nhs. The commercial CFD software Fluent 14 is used to model the fluid flow and the solid particle distribution in the tank. The 3D geometry of the tank and the associated mesh are respectively realized by Ansys 14 DesignModeler and Meshing. The Sliding-Mesh approach is used to take the impeller motion into account. Assuming that the discrete solid phase has no influence on the continuous liquid phase behaviour, the fluid flow dynamics may be simulated independently using the well-known k-ε turbulence model. The behaviour of the liquid-solid mixture is then described by implementing the Eulerian Mixture model. Liquid velocity fields simulated by CFD have been validated by comparison with PIV (Particle Image Velocimetry) measurements. Computed values of Nhs are compared with good agreement to experimental data obtained with a nephelometric probe. Results obtained at different scales allowed correlating the Nhs value to the volumetric power consumption. [less ▲]

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See detailEvaluation of Shielding Effectiveness in the Time Domain using a DG Method with an Efficient PML
Modave, Axel ULg; Geuzaine, Christophe ULg; Boubekeur, Mohamed et al

Poster (2013, April 24)

Development of new electric and electronic devices leads to an increasing importance for solving electromagnetic compatibility problems. In particular, the optimization of radiated emissions is ... [more ▼]

Development of new electric and electronic devices leads to an increasing importance for solving electromagnetic compatibility problems. In particular, the optimization of radiated emissions is increasingly done through numerical modeling. In this context, numerical methods allow to evaluate the effectiveness of more and more elaborate shielding enclosures. We propose an application of the nodal Discontinuous Galerkin method to evaluate the effectiveness of composite shieldings in the time domain. This numerical method provides convenient advantages to deal with shielding problems. Firstly, heterogeneous media are naturally included in the discrete formulation. After, the method is famous to allow a massive parallelization for the numerical resolution. Finally, a resolution in the time domain allows to consider transient signals. The numerical scheme is firstly validated using an academic benchmark. In the same way, the PML used to truncate the computational domain is optimized and validated. Applications are then presented for homogeneous and composite shieldings. The preliminary results are in conformity with classical predictive rules. [less ▲]

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See detailDiffuse urban and industrial groundwater pollution with metallic trace elements A comparison between affected and unaffected areas
Gesels, Julie ULg; Dollé, Fabien ULg; Leclercq, Julie et al

Poster (2013, April 22)

For metalic trace elements, spatially distributed background concentrations will be defined as a function of geological and hydrogeological context and considering the impact of diffuse pollution.

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See detailIntegrated field assessment of contaminant fate and transport in the unsaturated and saturated zone
Fernandez de Vera, Natalia ULg; Peña Hernandez, Juan Angel ULg; Jamin, Pierre ULg et al

Poster (2013, April 22)

In the poster, a multidisciplinary methodology is presented with the aim of characterizing fate and transport of pollutants in the vadose and the saturated zone of industrial sites. The methodology used ... [more ▼]

In the poster, a multidisciplinary methodology is presented with the aim of characterizing fate and transport of pollutants in the vadose and the saturated zone of industrial sites. The methodology used for the vadose zone consist in the combination of the Vadose Monitoring System, cross-hole and surface geophysics at a local scale. For saturated zone studies, the approach consist in the chemical and isotopic analysis of the various contaminants present on site at regional scale. [less ▲]

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See detailFunctional study of the Ser/Arg-rich splicing factor SRSF5a during zebrafish embryonic development.
Joris, Marine ULg; Larbuisson, Arnaud ULg; Muller, Marc ULg et al

Poster (2013, April 18)

To investigate the role of the splicing factor SRSF5a during zebrafish embryonic development, we performed SRSF5a knockdown by morpholino microinjection and we analysed control and morphant transcriptomes ... [more ▼]

To investigate the role of the splicing factor SRSF5a during zebrafish embryonic development, we performed SRSF5a knockdown by morpholino microinjection and we analysed control and morphant transcriptomes using RNA sequencing. [less ▲]

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See detailInfluence of the protein context in the aggregation of polyQ proteins into amyloid fibrils
Huynen, Céline ULg

Poster (2013, April 18)

Ten neurodegenerative diseases, referred to as polyglutamine (polyQ) diseases, are associated with the aggregation into amyloid fibrils of ten different proteins containing a polyQ expansion higher than a ... [more ▼]

Ten neurodegenerative diseases, referred to as polyglutamine (polyQ) diseases, are associated with the aggregation into amyloid fibrils of ten different proteins containing a polyQ expansion higher than a pathological threshold comprised between 35 to 45Q (1, 2). A large body of evidence indicate that the polyQ expansion is the critical determinant for the aggregation of these polyQ proteins. The aggregation process of polyQ proteins is, however, still not well understood. To better understand this mechanism at a molecular level, we have characterized model polyQ proteins made of the β-lactamase BlaP from Bacillus licheniformis 749/C and a polyQ tract of 0 to 79Q inserted either at position 197 or position 216 of BlaP. Those chimeras recapitulate the same aggregation behaviours than that of disease-associated polyQ proteins: there is a glutamine threshold for the aggregation into amyloid fibrils and the anticipation phenomenon. Most importantly, the threshold critically depends on the structural integrity of BlaP (3) which would impose some conformational and/or sterical constraints to the polyQ tract. Moreover the position of the polyQ insertion into BlaP modifies the aggregation propensity of BlaP chimeras. The present work aims to further investigate (i) how the protein context affects the different phases of the aggregation phenomenon (i.e. the nucleation and elongation phases) and (ii) the role of the oligomers formed during the early time of the aggregation process. The techniques used are mainly (1) quartz crystal microbalance (QCM) and atomic force microscopy (AFM) to study the elongation step of amyloid fibril formation and (2) dynamic light scattering (DLS) to study the evolution of the different populations formed during the aggregation time course. The results of these experiments indicate that the native conformation of BlaP197(Gln)55 interferes mainly with the nucleation but not with the elongation step of amyloid fibril formation. Moreover, these results demonstrate that the sequences flanking the polyQ tract significantly influence its propensity to elongate amyloid fibrils. Finally, they clearly indicate that the oligomers of BlaP197(Gln)79 observed at the early stage of the aggregation process are on the pathway of amyloid fibril formation, and likely constitute the aggregation nucleus. [less ▲]

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See detailMolecular analysis of root medium impact on Arabidopsis thaliana development
Bouché, Frédéric ULg; André, Julie; Tocquin, Pierre ULg et al

Poster (2013, April 18)

Hydroponics and soil are the most common media used for plant growth. Hydroponics has the main advantage of providing easy access to the root system and is therefore commonly used for gene expression ... [more ▼]

Hydroponics and soil are the most common media used for plant growth. Hydroponics has the main advantage of providing easy access to the root system and is therefore commonly used for gene expression analyses in molecular studies of the model plant Arabidopsis thaliana. However, the impact of root substrate on plant growth remains poorly documented. Here we show that hydroponics accelerates both shoot growth and developmental phases as compared with culture on soil. In order to identify molecular changes in the roots that could account for these medium effects, a transcriptomic comparison was performed by microarray analysis. This experiment revealed that more than 20% of the genes were differentially expressed in hydroponics vs soil. Among them, the flowering time gene FLOWERING LOCUS C and two clades of microRNA targeted genes. To further assess the role of these genes in roots, artificial microRNAs were designed for root specific expression in transgenic Arabidopsis plants. [less ▲]

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See detailStudy of the toxicity of migration products from food contact materials for children under 3 years old
Simon, Coraline ULg; Oghena, M.; Covaci, A. et al

Poster (2013, April 18)

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See detailTowards identification of active root-secreted proteases of Arabidopsis thaliana.
Lallemand, Jérôme ULg; Désiron, Carole ULg; Périlleux, Claire ULg et al

Poster (2013, April 18)

Besides traditional production systems, such as bacteria, yeasts and mammal cells, plants can now be used to produce eukaryotic recombinant proteins. Their advantages as hosts for proteins production ... [more ▼]

Besides traditional production systems, such as bacteria, yeasts and mammal cells, plants can now be used to produce eukaryotic recombinant proteins. Their advantages as hosts for proteins production include correct post-translational modifications, low cost of maintenance and no risk of contamination by human pathogens. Targeting heterologous proteins to the extracellular space is required for the correct folding of complex proteins and makes harvesting and purification easier. However, the quantity and the quality of recombinant proteins have been proved to be reduced by the action of endogenous co-secreted proteases. In this study, we characterized root-secreted proteases in the model plant Arabidopsis thaliana, at the activity and expression levels. Their activity was analyzed by in vitro degradation of a target protein (Bovine Serum Albumine, BSA) in a range of pH and in the presence of several proteases inhibitors. Serine proteases were identified as the major protease class involved in the degradation of BSA under all tested conditions. As a first step towards the identification of the key players, the expression level of selected members of this class was analyzed by quantitative RT-PCR in roots and leaves. [less ▲]

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See detailMicroorganisms living on algae : An interesting reservoir of enzymes hydrolyzing algal biomass
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2013, April 18)

Algal polysaccharides are increasingly used in food industry for their gelling properties and in pharmacology for their therapeutic properties. Furthermore, increasingly interest is taken on algae for ... [more ▼]

Algal polysaccharides are increasingly used in food industry for their gelling properties and in pharmacology for their therapeutic properties. Furthermore, increasingly interest is taken on algae for their use in the production of biofuels and bioenergies. To purify algal polysaccharides and degrade algal biomass, specific microbial enzymes are needed. Microorganisms living on algae are an interesting source of those enzymes, as they are in constant interaction with algal biomass. The aim of our study is to identify new enzymes degrading algae, produced by microorganisms living on the surface of algae. Therefore we developed a method for microbial DNA extraction from biofilms living on brown algae (Ascophyllum nodosum). Microbial DNA was extracted, restricted and inserted in cultivable host cells of Echerichia coli, for the construction of our metagenomic DNA library. This metagenomic library was first screened, on solid media with specific substrates, for enzymes generally used in the degradation of biomass (lipases, cellulases, proteases, beta-glucosidases, alpha-amylases, arabinanases and xylanases). Five lipolytic enzymes, one beta-glucosidase and one cellulase were identified. Those enzymes show very low percentages of sequences identities with known enzymes, meaning we identified new and unknown enzymes. Those enzymes and their activity are being characterized. Preliminary tests show interesting results, like a cellulase active at low temperature. Screening tests are now being developed to identify enzymes hydrolyzing algal polysaccharides like agarases, carrageenases, alginate lyases, laminarinases,… Those enzymes aren’t well known yet and we hope to identify new enzymes (families) with our rich DNA library by our approach. [less ▲]

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See detailImprovement of spray retention on barley leaves by adjuvants
Boukhalfa, Hassina dite Hafida ULg; Massinon, Mathieu ULg; Lebeau, Frédéric ULg

Poster (2013, April 18)

Adjuvants contribute to change the types of impact and thus the amount of spray retained by the leaves of the treated plant. We have performed tests of retention on barley plants on BBCH 12 stage and ... [more ▼]

Adjuvants contribute to change the types of impact and thus the amount of spray retained by the leaves of the treated plant. We have performed tests of retention on barley plants on BBCH 12 stage and small pieces of barley leaves at the same stage of growth. Spraying was done in three ways: water without adjuvant, water with Break-Thru® S240 and water with Li700®. The three slurries of fluorescein contained in an amount of 0.2 g / l. Fluorescein retained by the leaves in both cases is then measured by a spectrofluoremeter. The retention tests on whole plants show that it is tripled by the first adjuvant and doubled by the second. On the other side, on small pieces of barley leaves, the amount was increased by the use of surfactants but not to the same extend. This study concluded that the use of adjuvants in spray pesticides increases the amount of retention as a function of leaf area and the type of adjuvant. [less ▲]

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See detailGender Role Orientation, Emotional Intelligence and Anxiety Symptoms in Children
Stassart, Céline ULg; Dardenne, Benoît ULg; Etienne, Anne-Marie ULg

Poster (2013, April 18)

According to Gender Role Theory, girls and boys learn to develop interests and attitudes consistent with their gender, resulting in behaviors and characteristics known as “masculine” and “feminine” ... [more ▼]

According to Gender Role Theory, girls and boys learn to develop interests and attitudes consistent with their gender, resulting in behaviors and characteristics known as “masculine” and “feminine” (Golombok & Fivush, 1994). Several authors have claimed that gender role, more than sex (male vs. female), explains the higher prevalence of anxiety in girls than in boys (e.g., Palapattu, Kingery, & Ginsburg, 2006). The expression of fear and anxiety is accepted and even encouraged among girls but is inconsistent with the masculine gender role: Boys are expected to face their fears and use adaptive behavior to handle the situation (Bem, 1981). Although the link between anxiety and gender role is well known for adults, empirical evidence concerning children is much scarcer (Palapattu et al., 2006). In this study, we first examine the importance of gender role in children’s anxiety. We also investigate the influence of a possible moderator in the relation between anxiety and gender role: emotional intelligence (EI). EI has been shown to protect against the development of anxiety in children (Williams, Daley, Burnside, & Hammond-Rowley, 2010). Our sample included 200 Belgian children (105 girls) aged 9 to 13 years old. The questionnaires used were the State-Trait Anxiety Inventory for Children (STAIC; Spielberger, 1973), the Trait Emotional Intelligence Questionnaire Child Form (TEIQue-CSF; Mavrovelli & Petrides, 2008), and the Children’s Personal Attributes Questionnaire (CPAQ; Hall & Halberstadt, 1980). The latter questionnaire is composed of three subscales: Masculinity (M, male-stereotyped traits but socially desirable in both sexes, e.g., leadership), Femininity (F, female-stereotyped traits but socially desirable in both sexes, e.g., kindness), Masculinity-Femininity (M-F, traits socially more acceptable for one sex or the other, e.g., emotional vulnerability for females and aggressiveness for males). High scores on the M-F scale indicate tendencies toward masculinity. Hierarchical multiple regression analyses were conducted to investigate the effect of gender role on the STAIC score beyond biological sex and EI as a moderator in relations between gender role and anxiety. Results indicated that gender role explains the anxiety score better than biological sex. Also, EI and the interaction between EI and M-F scores (TEIQue-CSF*M-F) were significant predictors of anxiety score. The children with low M-F scores and low EI had significantly higher levels of anxiety, while those with high M-F scores and high EI had the lowest levels of anxiety. These findings reveal not only the effect of gender role in the development of anxiety, but also the moderating effect of EI. [less ▲]

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See detailValidation of a LC-MS analytical method for the measurement of aldehydes in meat and oil
Tihon, Angélique; Douny, Caroline ULg; Bayonnet, Pierre ULg et al

Poster (2013, April 18)

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See detailHydrocarbons contamination of smoked shrimp, an expanding food condiment in Beninese local markets
Kpoclou, Euloge; Brose, François ULg; Anihouvi, V.B. et al

Poster (2013, April 18)

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See detailStudy of a solar concentrator for space based on a diffractive/refractive optical combination
Michel, Céline ULg; Loicq, Jerôme ULg; Mazzoli, Alexandra ULg et al

Poster (2013, April 16)

This paper presents a new design of a planar solar concentrator for space applications focusing on two spatially separated PV cells, allowing independent control of output power of each cell. It has the ... [more ▼]

This paper presents a new design of a planar solar concentrator for space applications focusing on two spatially separated PV cells, allowing independent control of output power of each cell. It has the advantages of both spectral splitting and solar concentration by the combination of a blaze transmission diffraction grating and a flat cylindrical Fresnel lens. An optical optimization has been realized and two variations of configuration have been developed to improve tracking tolerance: first, a design completed by secondary reflective concentrators and second, a symmetrical configuration composed of two lenses. First numerical results are presented, highlighting the possibility to design a concentrator at about 10×, with an electrical output power about 290W/m² lens and less than 10% losses for tracking errors lower than ±0.9°. [less ▲]

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See detailEmulation of the MBM-MEDUSA model: exploring the sea level and the basin-to-shelf transfer influence on the system dynamics
Ermakov, Ilya; Munhoven, Guy ULg; Crucifix, Michel

Poster (2013, April 12)

Complex climate models require high computational burden. However, computational limitations may be avoided by using emulators. In this work we present several approaches for dynamical emulation (also ... [more ▼]

Complex climate models require high computational burden. However, computational limitations may be avoided by using emulators. In this work we present several approaches for dynamical emulation (also called metamodelling) of the Multi-Box Model (MBM) coupled to the Model of Early Diagenesis in the Upper Sediment A (MEDUSA) that simulates the carbon cycle of the ocean and atmosphere [1]. We consider two experiments performed on the MBM-MEDUSA that explore the Basin-to-Shelf Transfer (BST) dynamics. In both experiments the sea level is varied according to a paleo sea level reconstruction. Such experiments are interesting because the BST is an important cause of the CO2 variation and the dynamics is potentially nonlinear. The output that we are interested in is the variation of the carbon dioxide partial pressure in the atmosphere over the Pleistocene. The first experiment considers that the BST is fixed constant during the simulation. In the second experiment the BST is interactively adjusted according to the sea level, since the sea level is the primary control of the growth and decay of coral reefs and other shelf carbon reservoirs. The main aim of the present contribution is to create a metamodel of the MBM-MEDUSA using the Dynamic Emulation Modelling methodology [2] and compare the results obtained using linear and non-linear methods. The first step in the emulation methodology used in this work is to identify the structure of the metamodel. In order to select an optimal approach for emulation we compare the results of identification obtained by the simple linear and more complex nonlinear models. In order to identify the metamodel in the first experiment the simple linear regression and the least-squares method is sufficient to obtain a 99,9% fit between the temporal outputs of the model and the metamodel. For the second experiment the MBM’s output is highly nonlinear. In this case we apply nonlinear models, such as, NARX, Hammerstein model, and an ’ad-hoc’ switching model. After the identification we perform the parameter mapping using spline interpolation and validate the emulator on a new set of parameters. [less ▲]

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See detailValidation of the Structural-Thermal-Model of the Small Earth Observation Satellite Flying Laptop
Steinmetz, Fabian; Lengowski, Michael; Winter, Daniel et al

Poster (2013, April 10)

Thorough thermal design and testing is compulsory for every satellite mission. A well-known thermal behavior of the entire satellite system is therefore indispensable and needs to be verified during the ... [more ▼]

Thorough thermal design and testing is compulsory for every satellite mission. A well-known thermal behavior of the entire satellite system is therefore indispensable and needs to be verified during the spacecraft development. A Structural-Thermal-Model (STM) was constructed for the Flying Laptop, a satellite currently being developed at the Institute of Space Systems (IRS) of the University of Stuttgart, which enables the validation of mechanical and thermal simulations for the satellite’s Flight-Model. The STM was vibration and thermal-vacuum tested at the Centre Spatial Liège (CSL). This paper will de-scribe the design and construction of the STM as well as the facilities and test equipment used for the tests. Conclusions will be drawn from the actual test results. [less ▲]

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