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See detailBacillus-based biocontrol of Fusarium disease on tomato cultures in Burundi
Nihorimbere, Venant; Ongena, Marc ULg; Cawoy, Hélène ULg et al

Poster (2009, May 19)

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See detailMONITORING OF THE ENTOMOLOGICAL DIVERSITY IN A PESTICIDE FREE ORCHARD: INVESTIGATION OF THE GEMBLOUX AGRICULTURAL UNIVERSITY CONSERVATORY
Poligui, René Noël ULg; Haubruge, Eric ULg; Francis, Frédéric ULg

Poster (2009, May 19)

In orchards, the fruit production is currently oriented to integrated pest management. In order to develop efficient pest control strategy by using entomophagous beneficial and lowering the application of ... [more ▼]

In orchards, the fruit production is currently oriented to integrated pest management. In order to develop efficient pest control strategy by using entomophagous beneficial and lowering the application of pesticides, sufficient knowledge of entomological populations is needed. Here, a systematic monitoring of insect diversity and abundance in a conservatory orchard of Gembloux was performed. Combining yellow traps and visual observations, 19 pest and 34 beneficial families were identified among the 10766 and 3985 insects caught in yellow traps and visual observations respectively. Calculation of diversity indices allowed us to demonstrate the variability according to fruit tree species and insects observation method. Highest insects diversity was registered in apple, then in cherry and finally in the apple-pear association and plum. Pests and beneficials represented 27% and 39% of the insect collections respectively. Aphids represented from 81% to 95%of pests depending on fruit tree species and observation method. The predominant specie was Brachycaudus helychrysi (Kaltenbach). Aphidophagous guild was largely present and mainly constituted by coccinellids and hoverflies. Harmonia axyridis Pallas and Episyrphus balteatus De Geer were the most abundant. Aphididae was found to be the most common orchard pests with a range of related aphidophagous beneficials. These results highlight the need leading to potential reasoning . [less ▲]

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See detailPreparation of living polymer microspheres by dispersion atom transfer radical polymerization in scCO2 using fluorinated macroligands
Grignard, Bruno ULg; Calberg, Cédric ULg; Jérôme, Christine ULg et al

Poster (2009, May 19)

Due to an increasing need for polymers with well-defined architecture (diblock-, graft-, star-shaped copolymers), molecular weight and/or functional end-groups, the use of controlled radical ... [more ▼]

Due to an increasing need for polymers with well-defined architecture (diblock-, graft-, star-shaped copolymers), molecular weight and/or functional end-groups, the use of controlled radical polymerization (CRP) in scCO2 has started to gain attention. Among all the controlled processes, Atom Transfer Radical Polymerization has emerged as a robust tool for the preparation of polymers with well-defined molecular weight, architecture and chain-end functionality. In a very recent paper, we reported the first efficient dispersion ATRP of methyl methacrylate (MMA) in scCO2 using a fluorinated polymeric ligand that had a dual role, i.e., the complexation of the copper salt and the stabilization of PMMA growing particles. In this contribution, we extended this new system to the dispersion ATRP of styrene, to the synthesis of diblock copolymers beads and the controlled synthesis of hyperbranched copolymers. Finally, because both ATRP and alkyne-azide Huisgen’s 1,3-dipolar cycloaddition relies on the use of a Cu(I) catalyst, synthesis of pyrene end-functionalized polymers by simultaneous dispersion ATRP and click reaction was also investigated in supercritical carbon dioxide. [less ▲]

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See detailEvaluation of two protein extraction protocols for Pichia anomala proteome analysis.
Bajji, Mohammed; Delaplace, Pierre ULg; Mauro, Sergio et al

Poster (2009, May 19)

Pichia anomala (strain Kh6) was isolated from the surface of apple fruits and selected for its high and reliable biocontrol activity against Botrytis cinerea and Penicillium expansum. Its main modes of ... [more ▼]

Pichia anomala (strain Kh6) was isolated from the surface of apple fruits and selected for its high and reliable biocontrol activity against Botrytis cinerea and Penicillium expansum. Its main modes of action have until now been studied using essentially microbiological and molecular approaches. The study continues now using the proteomic approach and considering the in situ P. anomala/B. cinerea/apple interaction. Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is one of the most powerful tools used for proteomic analysis. It combines two sequential separation steps, the first dimension via isoelectric focusing (IEF) and the second one by SDS PAGE. Although recent advances in 2-D PAGE, the extraction of the whole proteome and the removal of interfering contaminants still limit its application. Sample preparation constitutes indeed a critical influential step for IEF which in turn affects 2-D gel quality. The objective of the present work was thus to develop an effective protein extraction protocol designed for 2-D PAGE analysis of the proteome of P. anomala strain Kh6. As a starting point, two contrasting protein extraction protocols were chosen to be evaluated in terms of protein yield and one-dimensional (1-D) SDS PAGE and 2-D PAGE gel patterns. The first protocol uses a urea/thiourea-based lysis buffer whereas the second protocol utilizes a hot SDS-based lysis buffer with an additional precipitation step. The comparison model used consisted of apples treated with strain Kh6 alone (K) and apples first treated with Kh6 and then inoculated with B. cinerea conidia (KB). Growth kinetics of strain Kh6 on wounded apples was determined and found to be not affected by the presence of B. cinerea conidia. Proteins were extracted from yeast pellets collected at both the exponential and stationary phases of strain Kh6 growth on apples. The evaluation of both extraction protocols indicates that more proteins were extracted with the SDS protocol and, according to 1-D assays, higher molecular weight proteins were obtained with the ‘urea/thiourea’ protocol and, regardless of the protocol used, more bands were obtained during the exponential phase. 2-D assays are currently underway and the corresponding results will be presented. [less ▲]

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See detailFunctionalization of aliphatic polyesters by “click chemistry” in supercritical carbon dioxide
Grignard, Bruno ULg; Schmeits, Stephanie ULg; Riva, Raphaël ULg et al

Poster (2009, May 14)

The combination of ring-opening polymerization of lactones and “click” copper-catalyzed Huisgen’s [3+2] cycloaddition is known to be a very efficient strategy for the functionalization of poly(ε ... [more ▼]

The combination of ring-opening polymerization of lactones and “click” copper-catalyzed Huisgen’s [3+2] cycloaddition is known to be a very efficient strategy for the functionalization of poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA). Whenever the “click” reaction occurs in an organic solvent (THF or DMF), at relatively low temperature (35°C) and within short reaction time (2 hours), no significant degradation of polyester chains is detected. This strategy was implemented in previous works to graft alkynes substituted by different functional groups, such as hydroxyl, tertiary amines, acrylates or ammonium salts onto azide-functionalized PCL. Moreover, this approach was previously extended to the synthesis of grafted copolymers, either by the grafting of omega-alkyne-PEO onto azide-functionalized aliphatic PLA or PCL (“grafting onto” technique) either by grafting of an ATRP initiator followed by the polymerization of vinyl monomers, such as styrene (“grafting from” technique). These functionalized aliphatic polyesters are promising materials for the development of new biomedical devices. In this work, novel conditions were implemented for the “click” reaction in order to avoid the use of organic solvents and to limit the amount of catalyst remnants in functionalized aliphatic polyesters. Toward this end, if was found that the functionalization by “click” chemistry can be efficiently carried out in supercritical carbon dioxide rather than in THF or DMF. For that sake, it turned out necessary to synthesize a perfluorinated polyamine in order to solubilize the catalyst in supercritical carbon dioxide. Aliphatic polyesters are not soluble in supercritical carbon dioxide. Nevertheless, even under heterogeneous conditions, the functionalization of aliphatic polyesters by “click” chemistry is quantitative. Interestingly enough, no degradation was observed. Last but not least, the copper catalyst was easily removed by supercritical fluid extraction leading to a very low content of residual copper in the final copolyester. [less ▲]

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See detailMannosylated amphiphilic and degradable PEO-b-PCL copolymers for drug delivery systems: preparation and sugar availability characterizations
Freichels, Hélène ULg; Imberty, Anne; Auezély-Velty, Rachel et al

Poster (2009, May 14)

Over the last decade, polymer micelles and nanoparticles attracted an increasing interest in pharmaceutical research because they can be used as efficient drug delivery systems. In this field, amphiphilic ... [more ▼]

Over the last decade, polymer micelles and nanoparticles attracted an increasing interest in pharmaceutical research because they can be used as efficient drug delivery systems. In this field, amphiphilic copolymers combining poly(ethylene oxide) and aliphatic polyester (such as poly(ε-caprolactone) (PCL) or polylactide (PLA)) are particularly of interest because (i) PEO has unique protein- repellent properties and thus provides a stealth behaviour to the drug carriers and (ii) aliphatic polyesters are biocompatible and biodegradable hydrophobic matrices well-suited for the incorporation of an hydrophobic drug. By end-capping the hydrophilic segment by a targeting moiety so that they may interact with membrane receptors, the biodistribution of polymeric micelles and nanoparticles stabilized with this copolymer can be modulated and can induce specific cellular uptake by receptor-mediated endocytosis. One class of interesting targeting agent is the saccharides, in particular the mannose, because of its specific interaction with mannose receptor, which are found on peripheral and bone marrow macrophages, dendritic cells and sinusoidal liver cells. In this study, the reductive amination reaction is use to attach this targeting agent. After optimisation of the reaction with amino fluorescein, a model amine, mannosylated copolymer of PEO and PCL has been prepared. The surface availability of the saccharide upon the micelles in aqueous phosphate buffer was then assessed by DLS through binding with the protein Concanavalin A (ConA), a known mannose receptor. The interactions between the Bcla lectin and the mannosylated micelles have then been studied by Isothermal Titration Calorimetry (ITC) and the thermodynamic parameters have been obtained. This polymer is particularly useful for the stabilization of PLGA nanoparticles with the goal to target M cells for oral vaccination. [less ▲]

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See detailDispersion nitroxide mediated polymerization of MMA in supercritical carbon dioxide
Grignard, Bruno ULg; Gigmes, Didier; Jérôme, Christine ULg et al

Poster (2009, May 14)

Controlled dispersion Nitroxide Mediated Polymerization (NMP) of methyl methacrylate (MMA) was successfully carried out for the first time in supercritical carbon dioxide (scCO2) in the presence of CO2 ... [more ▼]

Controlled dispersion Nitroxide Mediated Polymerization (NMP) of methyl methacrylate (MMA) was successfully carried out for the first time in supercritical carbon dioxide (scCO2) in the presence of CO2-philic perfluorinated surfactant that was generated “in situ”. The control of the MMA polymerization relies on the strategy developed by Charleux et al. that consists of using a SG1-based alkoxyamine, i.e. the block-builder, in the presence of small amount of styrene. In a first step, CO2 soluble polyheptadecafluorodecylacrylate was prepared in scCO2 using block-builder as an alkoxyamine. In a second step, nitroxide SG1 mediated dispersion polymerization of MMA was conducted at 70°C and 300 bar in the presence of 5 w% of SG1 terminated surfactant compared to the monomer. Different monomer to alkoxyamine molar ratios were investigated in order to target different molecular weights. In each case, the monomer conversion was high (>90 %), the experimental molecular weight was in good agreement with the theoretical value and the polydispersity was narrow (Mw/Mn ~1.2). Moreover, after depressurisation of the cell, PMMA was collected as a free flowing powder consisting of small sized microspheres. [less ▲]

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See detailpH-sensitive micellar systems for controlled drug delivery: synthesis and structural characterization by small-angle neutron scattering
Joset, Arnaud ULg; Jérôme, Christine ULg; Brulet, Annie et al

Poster (2009, May 14)

The aim of the project is the preparation of micellar nanocarriers made of biocompatibles copolymers and their structural analysis by Small Angle Neutron Scattering (SANS). These micelles could be used in ... [more ▼]

The aim of the project is the preparation of micellar nanocarriers made of biocompatibles copolymers and their structural analysis by Small Angle Neutron Scattering (SANS). These micelles could be used in drug delivery applications to fight cancer1. The hydrophobic polycaprolactone (PCL) core is intended to incorporate the drug. The corona of hydrophilic polyethylene oxide (PEO) stabilizes the nanocarriers with respect to the plasma proteins. The pH in the neighborhood of the tumoral cells is lower than in the healthy cells. We incorporated a pH-sensitive sequence of poly(2-vinylpyridine) (P2VP). As a result, these micelles are expected to deliver their drug near the cancerous cells without affecting the healthy cells. When the pH is acidic, the P2VP is protonated and the chains are repulsive. The micellar size is then larger than in basic pH, when the P2VP is precipitated on the PCL core. We prepared PCL65-b-P2VP31 / PCL65-b-PEO114 and PCL32-b-P2VP52 / PCL36-b-PEO114 50:50 mixtures of diblocks copolymers. The resulting mixed micelles are analyzed by SANS. We developed a theoretical model with a spherical water-free PCL core. The PEO corona is described as consisting of gaussian chains with a thickness estimated as twice the chain gyration radius, Rg. We propose two alternatives for handling the P2VP zone. The P2VP molecules are either assumed to be Gaussian chains or they fill a shell of thickness L with possible water penetration.The fitting of the models to the experimental scattering cross sections leads to important structural parameters like the aggregation number, the core radius, the gyration radius and the thickness of the P2VP shell. [less ▲]

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See detailSupporting cell cytoskeleton during development of the organ of Corti in rat
Johnen, Nicolas ULg; Thelen, Nicolas ULg; Malgrange, Brigitte ULg et al

Poster (2009, May 11)

The mammalian auditory organ, the organ of Corti (OC), is composed of mechanosensory hair cells and nonsensory supporting cell types. Based on their morphology and physiology, a least four types of ... [more ▼]

The mammalian auditory organ, the organ of Corti (OC), is composed of mechanosensory hair cells and nonsensory supporting cell types. Based on their morphology and physiology, a least four types of supporting cells can be identified in the OC: inner pillar cell, outer pillar cell, phalangeal cell and Deiter’s cells. All supporting cells are highly specialized cells that are characterized by the presence of bundled microtubules with 15 protofilaments instead of 13. Using antibobies against different proteins of cytoskeleton (tubulin, cutokeratin and vimentin), we investigated by confocal microscopy the setting up of supporting cells' cytoskeleton during the differentiation of the OC in art from the embryonic day 18 (E18) to the postnatal 15 (P15). We showed that the inner pillar cells are labelled with an anti-beta IV tubulin from P0. Using an antibody to cytokeratin, a labelling appeared in Deiters' cells from E22. We also revealed that during the development of the OC, supporting cells were labelled with an anti-vimentin antibody from P0. [less ▲]

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See detailA role for PSA-NCAM-dependent neuron-glia interactions in the control of GnRH neuron activity
Franceschini, Isabelle; Desroziers, Elodie ULg; Lomet, Didier et al

Poster (2009, May)

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See detailValidation of a measure of leader behavioral adequacy
De Zanet, Fabrice ULg; Stinglhamber, Florence; Dujardin, Jean-Marie ULg

Poster (2009, May)

Detailed reference viewed: 33 (13 ULg)
See detailCombine pedigree and marker information into a single estimator for the calculation of relationships
Bömcke, Elisabeth ULg; Gengler, Nicolas ULg

Poster (2009, May)

Relationship coefficients are particularly useful to improve genetic management of endangered populations. Estimation of relationships was traditionally based on pedigree data but, today, numerous methods ... [more ▼]

Relationship coefficients are particularly useful to improve genetic management of endangered populations. Estimation of relationships was traditionally based on pedigree data but, today, numerous methods already exist to replace pedigrees by molecular data. However, genotyping a complete population for a sufficient number of markers can be impossible, e.g., in case of local and/or rare breeds. The idea was therefore to develop a new method to estimate relationship by combining molecular with pedigree data into a single estimator. Originally developed for the management of an endangered horse population, it will be useful for specific situations, where neither pedigree nor molecular data are complete. Two questions appeared: What and how to combine? Following the principle that things have to be similar to be combined, we compared two coefficients that have the advantage to be similarly defined: the additive relationship coefficient (axy) calculated from pedigrees and the total allelic relationship (taxy) obtained from markers. Wright relationship coefficient (rped,xy) were also compared to taxy, transformed into rmol,xy, to highlight the influence of inbreeding. The results showed the influence of inbreeding, of marker quality and the tendency of molecular coefficients to overestimate the relationship among individuals. The method to combine the selected coefficients was also determined. Various parameters were taken into account in the model: number of markers and quality (e.g. marker informativeness), mutation rate, pedigree quality (e.g. generation-equivalents), … The combined estimator has several advantages. Especially, negative relationship values obtained in literature with molecular-based estimators in case of small inbred populations can be avoided. [less ▲]

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See detailAn instrument to analyse the representation of socio-constructivist approach in Wallonian physical education teachers
Cloes, Marc ULg; Berwart, Gilles; Frédéric, Olivier

Poster (2009, May)

Socio-constructivism is a learning process where people build their knowledge with help of interactions with others as well as with their milieu. The support to teaching strategies respecting the ... [more ▼]

Socio-constructivism is a learning process where people build their knowledge with help of interactions with others as well as with their milieu. The support to teaching strategies respecting the principles of socio-constructivist approaches is growing in the field of education. hysical education teacher educators propose more and more this concept as a guide to their students. Interventions are also proposed to make inservice teachers sensitive to it. ... [less ▲]

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See detailNEMA NU1-2001 performance tests of two Philips Brightview cameras
Seret, Alain ULg

Poster (2009, May)

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See detailIs hypoxia-inducible factor 1 an actor in migraine pathogenesis?
TRUONG, Julie ULg; Mascetti, Laura; Schoenen, Jean ULg et al

Poster (2009, May)

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See detailAnalysis of the representations of school and physical education roles in combating obesity
Cloes, Marc ULg; Ziant, Nicolas

Poster (2009, May)

Obesity is currently one of the priorities for interventions in health promotion. This study aimed to identify the perceptions of two groups of subjects about what school and PE could/should do in ... [more ▼]

Obesity is currently one of the priorities for interventions in health promotion. This study aimed to identify the perceptions of two groups of subjects about what school and PE could/should do in relation to the issues of obesity among young people. [less ▲]

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See detailSeasonal variability of carbon dioxide and methane in the rivers and lagoons of Ivory Coast (West Africa)
Koné, Y.J.M.; Abril, G.; Delille, Bruno ULg et al

Poster (2009, May)

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See detailInfluence functions of the error rates of classification based on clustering
Ruwet, Christel ULg; Haesbroeck, Gentiane ULg

Poster (2009, May)

Cluster analysis may be performed when one wishes to group similar objects into a given number of clusters. Several algorithms are available in order to construct these clusters. In this poster, focus ... [more ▼]

Cluster analysis may be performed when one wishes to group similar objects into a given number of clusters. Several algorithms are available in order to construct these clusters. In this poster, focus will be on two particular cases of the generalized k-means algorithm : the classical k-means procedure as well as the k-medoids algorithm, while the data of interest are assumed to come from an underlying population consisting of a mixture of two groups. Among the outputs of these clustering techniques, a classification rule is provided in order to classify the objects into one of the clusters. When classification is the main objective of the statistical analysis, performance is often measured by means of an error rate. Two types of error rates can be computed : a theoretical one and a more empirical one. The first one can be written as ER(F, Fm) where F is the distribution of the training sample used to set up the classification rule and Fm (model distribution) is the distribution under which the quality of the rule is assessed (via a test sample). The empirical error rate corresponds to ER(F, F), meaning that the classification rule is tested on the same sample as the one used to set up the rule. In case there are some outliers in the data, the classification rule may be corrupted. Even if it is evaluated at the model distribution, the theoretical error rate may then be contaminated, while the effect of contamination on the empirical error rate is two-fold : the rule but also the test sample are contaminated. To measure the robustness of classification based on clustering, influence functions have been computed, both for the theoretical and the empirical error rates. When using the theoretical error rate, similar results as those derived by Croux et al (2008) and Croux et al (2008) in discriminant analysis were observed. More specifically, under optimality (which happens when the model distribution is FN = 0.5N(μ1, ) + 0.5N(μ2, ), Qiu and Tamhane 2007), the contaminated error rate can never be smaller than the optimal value, resulting in a first order influence function identically equal to 0. Second order influence functions would then need to be computed, as this will be done in future research. When the optimality does not hold, the first order influence function of the theoretical error rate does not vanish anymore and shows that contamination may improve the error rate achieved under the non-optimal model. Similar computations have been performed for the empirical error rate, as the poster will show. The first and, when required, second order influence functions of the theoretical and empirical error rates are useful in their own right to compare the robustness of the 2-means and 2-medoids classification procedures. They have also other applications. For example, they may be used to derive diagnostic tools in order to detect observations having an unduly large influence on the error rate. Also, under optimality, the second order influence function of the theoretical error rate can yield asymptotic relative classification efficiencies. [less ▲]

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See detailAir-ice CO2 fluxes in the Arctic coastal area
Geilfus, Nicolas-Xavier ULg; Tison, Jean Louis; Carnat, Gauthier et al

Poster (2009, May)

Detailed reference viewed: 73 (3 ULg)
See detailLatitudinal and local time distribution of the O2 infrared nightglow and O density in the lower thermosphere
Soret, Lauriane ULg; Gérard, Jean-Claude ULg; Saglam, Adem et al

Poster (2009, May)

Atomic oxygen is the major component in the Earth’s upper thermosphere. The O density reaches a maximum of about 3x1010 cm-3 near 100 km. The 1.27 µm emission of the IR Atmospheric bands generated by ... [more ▼]

Atomic oxygen is the major component in the Earth’s upper thermosphere. The O density reaches a maximum of about 3x1010 cm-3 near 100 km. The 1.27 µm emission of the IR Atmospheric bands generated by recombination of O atoms has been observed in the nightglow. On the night side, the O2 airglow peaks at ~95 km with a value of ~10 MR. <br />Atomic oxygen is present in the Martian atmos-phere but that the intensities values are below the cur-rent instrument detectability threshold. The Mars at-mosphere oxygen density is highly variable, depending on the altitude, temperature, latitude and longitude. <br />On Venus, atomic oxygen has been measured in situ only above 145 km on both the day and the night sides. Limb observations obtained with the Venus In-frared Thermal Imaging Spectrometer (VIRTIS) on board Venus Express show that the O2 infrared nightglow peaks at ~97 km, with a mean intensity val-ue of about 1,3 MR [1, 2]. Yet, the distribution is largely inhomogeneous, with an enhanced region of ~3 MR statistically located near the midnight meridian at low latitude [3]. The oxygen density can be mapped using the O2 airglow and CO2 density vertical distribu-tions [4]. The O2 volume emission rates are obtained with an Abel inversion of the O2 limb profiles and CO2 vertical distributions are taken from the Venus International Reference Atmosphere (VIRA) model. The results show that the O density peak is located between 93 and 105 km (with a mean value of 104 km) and ranges from 2.8x1010 to 8.5x1011 cm-3 (with a mean value of 2.2x1011 cm-3). No correlations between the peak altitude and the latitude or the peak altitude and the local time are observed. However, the O density decreases and its variability increases while moving away from the antisolar point. [less ▲]

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See detailProduction of Biopolymers from Sugar Beet Pulp
Meyer, Laurence ULg; Paquot, Michel ULg; Dubois, Philippe

Poster (2009, May)

Sugar beet pulp is an important by-product of the sugar industry. In order to make the most of this waste, pectin extraction can constitute an economical solution. Pectin is commonly used in food industry ... [more ▼]

Sugar beet pulp is an important by-product of the sugar industry. In order to make the most of this waste, pectin extraction can constitute an economical solution. Pectin is commonly used in food industry as a gelling agent. However, in the present study another use of pectin is considered: its potential embedding into biodegradable polymer films which can further be used in plastic industry. At first, different pectin extraction methods have been developed on sugar beet pulp in order to obtain four different types of pectins characterized at the same time by their molecular weight degree of esterification. Acidic extraction leads to pectin of high molecular weight and high degree of esterification. From this pectin, a de-esterification and a de-polymerization allow us to obtain, respectively, a pectin of high molecular weight and low degree of esterification and a pectin of low molecular weight and high degree of esterification. On the other hand, a basic extraction leads to pectin of low molecular weight and degree of esterification. Preliminary, tests have been conducted on mixes comprising 5, 10, 15, 20 % of commercial pectin and PLA (polylactic acid) or PBAT (Polybutylen-adipate terephtalate). In all cases, the products were not stable and therefore the use of a compatibilizing agent was required. Glycerol and D-Sorbitol were thus studied for that purpose, in mixing ratios between 40-80 % with commercial pectin. The best mechanical properties (Young modulus; yield stress and yield strain) were obtained with the pectin/sorbitol 50/50 mix. This proportion was then used with our different sugar beet pulp extracted pectins to produce PLA/pectin/Sorbitol 50/25/25 formulations. The best mechanical properties were reached with the low molecular weight end degree of esterification pectin. Indeed, the relative small size of this pectin with the lack of esterified groups enables interactions between pectin chains plastified by sorbitol and PLA. These interactions lead to a better cohesion of the high pectic content biomaterial. [less ▲]

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See detailALMA - Parentalité et alimentation dans les milieux d'accueil collectifs de la petite enfance
Absil, Gaëtan ULg; Demarteau, Michel; Bauwens, Hélène et al

Poster (2009, May)

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See detailDetection and characterization of tilted peptides in amyloid proteins
Crowet, Jean-Marc ULg; Lins, Laurence ULg; Brasseur, Robert ULg

Poster (2009, April 25)

The study of amyloidogenic proteins is of interest in biochemistry because these proteins undergo conformational changes and aggregation. Both processes are largely implicated in several diseases ... [more ▼]

The study of amyloidogenic proteins is of interest in biochemistry because these proteins undergo conformational changes and aggregation. Both processes are largely implicated in several diseases including Alzheimer’s, Parkinson’s or Creutzfeldt-Jakob’s disease. These phenomena are not completely understood, either at a structural or energetical point of view. Tilted peptides are short protein fragment (11 to 19 residues) that adopt a tilted orientation when inserted into biological membranes and destabilise them. Recently, tilted peptides have been detected in two amyloidogenic proteins involved in neurodegenerative diseases; the amyloid  peptide responsible for Alzheimer’s disease, and the PrP protein that causes Creutzfeldt-Jakob’s disease. Tilted peptides could be responsible for the neurotoxic effects of these proteins. Due to their destabilising properties, they could interact directly with the membrane leading to cell death. Tilted peptides could also be involved in the transconformational process of the proteins. The aim of this work is to detect tilted fragments in other amyloidogenic proteins by molecular modelling and to study some of these peptides experimentally to evidence their lipid destabilizing properties, their structure and their toxicity. Twenty-four tilted peptides from 18 different proteins have been detected among 53 amyloidogenic proteins and 7 peptides were tested experimentally. The results support the hypothesis that some tilted peptides could be involved in transconformational processes and/or cytotoxicity related to amyloidogenic proteins. [less ▲]

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See detailNovel (co)polymers by cobalt-mediated radical polymerization
Debuigne, Antoine ULg; Piette, Yasmine ULg; Poli, Rinaldo et al

Poster (2009, April 24)

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See detail3D modelling of the Black Sea ecosystem
Capet, Arthur ULg; Beckers, Jean-Marie ULg; Joassin, Pascal et al

Poster (2009, April 24)

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See detailThe 1958-2008 Greenland ice sheet surface mass balance variability simulated by the regional climate model MAR
Fettweis, Xavier ULg

Poster (2009, April 24)

Results made with the regional climate model MAR over 1958-2008 show a very high interannual variability of the Greenland ice sheet (GrIS) surface mass balance (SMB) modelled in average to be 330 +/- 130 ... [more ▼]

Results made with the regional climate model MAR over 1958-2008 show a very high interannual variability of the Greenland ice sheet (GrIS) surface mass balance (SMB) modelled in average to be 330 +/- 130 km^3/yr. To a first approximation, the SMB variability is driven by the annual precipitation anomaly minus the meltwater run-off rate variability. Sensitivity experiments carried out by the MAR model evaluate the impacts on the surface melt of (i) the summer SST around the Greenland, (ii) the snow pack temperature at the beginning of the spring, (iii) the winter snow accumulation, (iv) the solid and liquid summer precipitations and (v) the summer atmospheric circulation. This last one, by forcing the summer air temperature above the ice sheet, explains mainly the surface melt anomalies. [less ▲]

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See detailInterannual variability of CO2 fluxes and yield by a winter wheat crop (Triticum aestivum L.)
Dufranne, Delphine ULg; Vancutsem, Françoise ULg; Moureaux, Christine ULg et al

Poster (2009, April 20)

In this study, two winter wheat (Triticum aestivum L.) cropping seasons were compared at the Lonzée (Belgium) experimental site. The site, crop management, sowing and harvest dates were similar on the two ... [more ▼]

In this study, two winter wheat (Triticum aestivum L.) cropping seasons were compared at the Lonzée (Belgium) experimental site. The site, crop management, sowing and harvest dates were similar on the two years. The main difference between the seasons was due to to climate conditions. Continuous eddy-covariance fluxes, leaf scale photosynthesis measurements and crop development monitoring were performed during the whole vegetation periods. Globally, the two years were characterised by a higher than normal air temperature (9.9 °C and 11.9 °C respectively against 9.4 °C for standard) and lower than normal rainfalls (595.1 mm and 675.1 mm respectively against 772 mm for standard). In addition, the second season (2006-2007) was characterised by an exceptionally mild winter, dry and hot conditions in April and by humid and cloudy conditions during the last vegetation phases. These particular conditions induced earlier growth stages and the comparison of global fluxes gives contrasting results: gross primary productivity (GPP) was larger in 2007 but, on the contrary, net primary productivity (NPP) and crop productivity were lower on this year. The bad yields could be explained, on one hand by the drought in April 2007 that induced abnormally small flag leaves, on the other hand by cloudy and humid conditions from end May to harvest, that induced an assimilation reduction due to low radiation and favoured disease development. The simultaneous higher GPP and lower NPP and productivity in 2006-2007 raise the question of carbon allocation. It suggests that the excess carbon assimilated in 2006-2007 was not stored in grain or straw and thus that it would have been stored in the roots or in vegetation parts that decompose before the harvest. Further biomass measurements (and especially root biomass) are necessary to confirm this hypothesis. [less ▲]

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See detailA new mechanism of upwelling generated filaments based on potential vorticity balance
Troupin, Charles ULg; Mason, Evan; Beckers, Jean-Marie ULg et al

Poster (2009, April 19)

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See detailBiogeochemistry and carbon budget during a coccolithophorid bloom in the northern Bay of Biscay (June 2006)
Harlay, Jérôme ULg; Borges, Alberto ULg; De Bodt, Caroline et al

Poster (2009, April 19)

Carbon cycling processes (primary production (PPp), calcification (CAL), bacterial production and pelagic community respiration (PCR)) and variables (partial pressure of CO2 (pCO2) and total alkalinity ... [more ▼]

Carbon cycling processes (primary production (PPp), calcification (CAL), bacterial production and pelagic community respiration (PCR)) and variables (partial pressure of CO2 (pCO2) and total alkalinity (TA)) were measured in early June 2006 at several stations in the northern Bay of Biscay. These measurements were characterized with respect to the coccolithophorid blooming (growth or decline) based on satellite remote sensing (high reflectance (HR)) and other biogeochemical measurements i.e. inorganic nutrients, chlorophyll-a (Chl-a), phaeopigments (Phaeo), particulate inorganic carbon (PIC), particulate organic carbon (POC) and particulate nitrogen (PN)). The major HR patch was located over the shelf, along the continental margin and corresponded to declining bloom conditions characterized by moderate Chl-a <1.0 µg L-1, dissolved phosphate (PO4) depletion, low (<2.0 µmol L-1) dissolved silicate (DSi), low potential primary production (<0.25 µmol C L-1 h-1) and calcification rates (0.02-0.10 µmol C L-1 h-1). Yet, surface waters were undersaturated in CO2 with respect to atmospheric equilibrium. We present a coherent scheme of the C dynamics of a coccolithophorid bloom along the continental margin of the Bay of Biscay, an active hydrodynamic area, based on standing stocks and processes including 14C-based particulate primary production, CAL and PCR. A carbon budget obtained by integrating PPp, CAL and PCR over the water column highlights the importance of C extracellular production to sustain the bacterial demand in the twilight zone, which has also several repercussions on the fate of organic and inorganic C production in the photic zone during the different stages of the bloom. [less ▲]

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See detailS,T-climatologies of the North Sea using the Variational Inverse Method
Scory, Serge; Ouberdous, Mohamed ULg; Troupin, Charles ULg et al

Poster (2009, April 19)

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See detailPlant growth promotion of tomato under field conditions in Burundi
Cawoy, Hélène ULg; Nihorimbere, Venant; Kakana, Pascal et al

Poster (2009, April 02)

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See detailNanocoatings of inorganic surfaces by the layer by layer (LbL) technology
Faure, Emilie ULg; Zocchi, Germaine ULg; Lenoir, Sandrine et al

Poster (2009, April 02)

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See detailLight scattering properties of exopolysaccharide solutions.
Lespineux, David; Sevrin, Chantal ULg; Freitas, F et al

Poster (2009, April 01)

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See detailBiodegradable microcarriers for tissue engineering.
Tsoy, A; Markvicheva, E; Lespineux, David et al

Poster (2009, April 01)

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See detailAnomalous behaviour in the diffusion of polyethylene oxide through dialysis membrane
Vignisse, Julie ULg; Gustin, Audrey; Lespineux et al

Poster (2009, April 01)

Dialysis is a common technique adopted in biochemistry to purify biopharmaceutical drugs. This methodology is also of interest in macromolecular chemistry and pharmaceutical nanotechnology in order to ... [more ▼]

Dialysis is a common technique adopted in biochemistry to purify biopharmaceutical drugs. This methodology is also of interest in macromolecular chemistry and pharmaceutical nanotechnology in order to purify synthetic macromolecules and nanodrug carriers designed for drug delivery purposes. However, based on their original applications, the diffusion characteristic of the dialysis membrane is given in respect to the diffusion rate of globular proteins. So the diffusion capacity is function of molecular weight cut-off, i.e. corresponding to the maximum molecular weight of a globular macromolecule to be able to cross the membrane. The diffusion kinetics of synthetic macromolecules is expected to differ significantly from globular proteins due to at least the following differences : Specific relationship between hydrodynamic diameter and molecular weight, Flexibility Ionic density Solubility/miscibility/adsorption behaviour with the dialysis membrane Polymer chain entanglement above a critical concentration. In view to validate the application of this technique to purify synthetic macromolecules, we have compared the diffusion ability of neutral polyethyetylene oxide (PEO) standards or poly(dimethyl-aminoethyl-methacrylate) (PMADAM) to protein standards (human insulin and ovalbumin). [less ▲]

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See detailHemoreactivity of poly (dimethyl-aminoethyl-methacrylate) designed for the production of stealth red blood cells
Cerda, B; Pérez, E; Flores, H et al

Poster (2009, April 01)

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See detailDetermination of phospholipids extracted from Tsukamurella paurometabola C-924 after freeze-drying and during the subsequent storage.
Coulibaly, Ibourahema ULg; Yao, Amenan Anastasie ULg; Dubois Dauphin, Robin ULg et al

Poster (2009, April 01)

The total lipids of Tsukamurella paurometabola C-924 were analysed after freeze-drying. Seven individual lipids classes were identified namly neutral lipids (NLs), fatty acids (FAs), phospholipids (PLs ... [more ▼]

The total lipids of Tsukamurella paurometabola C-924 were analysed after freeze-drying. Seven individual lipids classes were identified namly neutral lipids (NLs), fatty acids (FAs), phospholipids (PLs), sterol ester (SEs), triglycerides (TGs), diglycerides (DGs) and monoglycerides (MGs). The principal fatty acids identified in most lipid classes were palmitic (C16:0), palmitoleic (C16:1), oleic (C18:1), linoleic (C18:2), and linolenic (C18:3). PLs were the major constituents and accounted for 50-60% of the total lipids. PLs were fractionated. . PLs of Tsukamurella paurometabola content phosphatidic acid (PA), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), sphingomyelin (SM), lysophosphatidylcholine (LPC) and phosphatidylglycerol (PG). It was observed that PG had the highest proportion at most points relative to other PLs and was the predominant component of PLs (30%-56%). Evolution of individual rate was followed during stored at 20°C and 40°C with or without lithothamne400®, respectively. [less ▲]

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See detailPhysico-chemical characterization of new polyhydroxyburates (PHB).
Ottevaere, M; Lespineux, David; Sevrin, Chantal ULg et al

Poster (2009, April 01)

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See detailActivation of the complement by PLGA nanoparticles : an in vitro study.
Sevrin, Chantal ULg; Cerda, B; Patronidou, C et al

Poster (2009, April 01)

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See detailPreparations and characterisations of semi-solid formulations containing a hydrophilic drug for vaginal administration
Coia, Isabelle ULg; Evrard, Brigitte ULg; Piette, Marie ULg

Poster (2009, April 01)

The purpose of this study is to demonstrate the effect of different types of semi-solid formulations (aqueous gels, liquid jellified emulsions and hydrophilic or lipophilic creams) for vaginal ... [more ▼]

The purpose of this study is to demonstrate the effect of different types of semi-solid formulations (aqueous gels, liquid jellified emulsions and hydrophilic or lipophilic creams) for vaginal administration on the release kinetic of a hydrophilic drug. This drug is an acidic and hydrophilic (log P (octanol/water) = -3.3) molecule with an aqueous solubility upper than 170mg/ml at pH 6-8. The formulations characterisations consisted in the in vitro evaluation of the drug release kinetic and the measure of all formulations viscosity as well as the creams stability and emulsions droplets size. [less ▲]

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See detailCycles in the Temperature Data Are Induced by the Sun
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

Poster (2009, April)

The presence of two cycles of period of 30 and 42 months approximatively has been observed in temperature records and climatic indices. Moreover, it has been shown that these cycles are statistically ... [more ▼]

The presence of two cycles of period of 30 and 42 months approximatively has been observed in temperature records and climatic indices. Moreover, it has been shown that these cycles are statistically significant. Here we outline the role played by the Sun in the presence of these cycles, observed in time series. To do so, we use IPCC AR4 climatic models, sunspot number data and the Morlet wavelet method. [less ▲]

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See detailEffects of consolidation of procedural motor memory traces on slow and fast spindles
Barakat, M; Doyon, J; Debas, K et al

Poster (2009, April)

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See detailExperimental evaluation of flux footprint by natural tracer experiment
Arriga, N.; Aubinet, Marc ULg; Carrara, A. et al

Poster (2009, April)

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See detailGreenland ice sheet projections from IPCC AR4 global models
Franco, Bruno ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2009, April)

The atmosphere-ocean general circulation models (AOGCMs) used for the IPCC 4th Assessment Report (IPCC AR4) are evaluated for the Greenland ice sheet (GrIS) current climate modelling. The most efficient ... [more ▼]

The atmosphere-ocean general circulation models (AOGCMs) used for the IPCC 4th Assessment Report (IPCC AR4) are evaluated for the Greenland ice sheet (GrIS) current climate modelling. The most efficient AOGCMs are chosen by comparison between the 1970-1999 outputs of the Climate of the twentieth Century experiment (20C3M) and reanalyses (ECMWF, NCEP/NCAR). This comparison reveals that surface parameters such as temperature and precipitation are highly correlated to the atmospheric circulation (500 hPa geopotential height) and its interannual variability (North Atlantic oscillation). The outputs of the three most efficient AOGCMs are then used to assess the changes planned by three IPCC greenhouse gas emissions scenarios (SRES) for the 2070-2099 period. Future atmospheric circulation changes should dampen the west-to-east circulation (zonal flow) and should enhance the Meridional Overturning Circulation (MOC). As a consequence, this provides more heat and moisture to the GrIS, increasing temperature on the whole ice sheet and precipitation on the north-eastern region. It is also shown that the GrIS surface mass balance (SMB) anomalies from the SRES A1B scenario are about -300 km³/yr with respect to the 1970-1999 period, leading to 5 cm of global sea-level rise (SLR) for the end of the 21st century. This work helps to choose the boundaries conditions for AOGCMs downscaled future projections. [less ▲]

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See detailChronologie de l’architecture médiévale : application à l’église Saint-Irénée de Lyon (69)
Bouvier, Armel; Reynaud, Jean-François; Guibert, Pierre et al

Poster (2009, April)

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See detailCO2 fluxes exchanged by a 4-year crop rotation cycle
Aubinet, Marc ULg; Moureaux, Christine ULg; Bodson, Bernard ULg et al

Poster (2009, April)

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See detailN-REM sleep slow oscillations amplitude and density in the young and middle-aged men and women
Viens, I; Lafortune, M; Poirier, G et al

Poster (2009, April)

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See detailEffects of aging and daytime recovery sleep on N-REM slow oscillations
Lafortune, M; Viens, I; Poirier, J et al

Poster (2009, April)

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See detailDetermination of isotopic fractionation delta13C of methane from ground-based FTIR observations performed at the Jungfraujoch
Duchatelet, Pierre ULg; Mahieu, Emmanuel ULg; Sussmann, Ralf et al

Poster (2009, April)

Atmospheric methane (CH4) is a strong greenhouse gas that has important chemical impacts on both the troposphere and the stratosphere. In the troposphere, oxidation of methane is a major regulator of OH ... [more ▼]

Atmospheric methane (CH4) is a strong greenhouse gas that has important chemical impacts on both the troposphere and the stratosphere. In the troposphere, oxidation of methane is a major regulator of OH and is a source of formaldehyde, carbon monoxide and hydrogen. In the stratosphere, CH4 plays a central role (i), due to its contribution to the stratospheric water vapor budget, and (ii), as a sink for chlorine atoms which reduces the rate of stratospheric ozone depletion. Because the different sources of methane (natural and anthropogenic like wetlands, rice paddies, termites, natural gas escape, biomass burning, etc) have distinct 13C/12C ratios (usually reported in “delta” notation δ13C), measurements of atmospheric 13CH4 content, in addition to those of the main isotopologue (12CH4), can be used to investigate individual source strengths as well as their spatial and temporal distributions. Characterization of the isotopic fractionation of methane is therefore important, for example, to help models constrain estimates of the global methane budget. However, experimental data for the 13C/12C isotope ratio are sparse. The currently accepted average value of δ13C in atmospheric methane is about -47‰ (Platt et al., 2004). The first goal of this work is to develop and to characterize (in terms of information content and error budget) an original retrieval approach to derive 13CH4 columns from ground-based Fourier transform infrared (FTIR) spectra recorded at the International Scientific Station of the Jungfraujoch (ISSJ; 46.5°N, 8.0°E, 3580m a.s.l., Swiss Alps). The retrieval strategy is based on a Tikhonov L1 approach which has been originally developed for 12CH4 by Sussmann et al. (2008) [see also contributions by Sussmann et al. to this conference (EGU2009-7869)]. In order to validate our 13CH4 products, comparisons with satellite ACE-FTS (Atmospheric Chemistry Experiment - Fourier Transform Spectrometer) measurements are performed. Then, atmospheric δ13C ratios derived from the FTIR measurements will be compared to values published in the literature and critically discussed. References: Platt, U., W. Allan and D. Lowe, Hemispheric average Cl atom concentration from 13C/12C ratios in atmospheric methane, Atmos. Chem. Phys., 4, 2393-2399, 2004. Sussmann, R., Forster, F., Borsdorff, T., et al.: Satellite validation of column-averaged methane on global scale: ground-based data from 15 FTIR stations versus last generation ENVISAT/SCIAMACHY retrievals, IGAC 10th International Conference, Annecy, France, 7-12 Sep 2008. [less ▲]

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See detailLayer-by-layer self-assembled chitosan coating on electrospun nanofibers
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, April)

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well-known method for surface ... [more ▼]

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyions including synthetic and natural materials, with designable layer structure, defined wall thickness and size. Electrospinning (ESP) technique allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fibers mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to obtain charges on fibers surface. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the existence of a multilayered shell, obtaining hollow fibers. [less ▲]

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See detailEvidence of an atypical scale development during the settlement phase of a coral reef fish
Frederich, Bruno ULg; Lecchini, David; Vandewalle, Pierre ULg

Poster (2009, April)

As the majority of coral reef fishes, the Convict Surgeonfish Acanthurus triostegus (Acanthuridae) has a complex life cycle that involves an ontogenetic change in morphology, physiology and behaviour as ... [more ▼]

As the majority of coral reef fishes, the Convict Surgeonfish Acanthurus triostegus (Acanthuridae) has a complex life cycle that involves an ontogenetic change in morphology, physiology and behaviour as its pelagic larval stage colonizes the benthic habitat. Abrupt and spectacular changes in skeletal structures occurring when a fish takes on its juvenile form were highlighted in flatfish, bonefish, tarpon, eels, pearlfish and lampreys. However, few studies are devoted to the changes in skeleton during the settlement period of demersal coral reef fishes. In the present study conducted at Rangiroa Atoll (French Polynesia), we highlight an unexpected scales development in A. trisostegus during a fifteen days period just after the reef settlement. Fish was collected during the settlement and reared in aquaria. The osseous skeleton was displayed by a standard Alizarin red S staining technique. At settlement (t0) (SL = 22-25 mm), A. triostegus showed calcified and very long plates, lying in the dermis on the whole body. After three days, some small scales developed on the caudal peduncle. The plates seemed unchanged from the head to the pectoral girdle but were thinner on the trunk. The thin plates are pricked with whitish spots, which seem to indicate a poorer fixation of the alizarin corresponding to a decalcification process. Six days after the settlement, the squamation extended anteriorly to the pectoral girdle by the addition of new scales. Thin plates were always present on the head. Then the density of scales rapidly increased along the trunk during the following three days. The scales appeared on the head nine days after the settlement. Clearly, the plates do not transform into scales. The plates disappearance and the scales appearance appear as two parallel phenomena in the development. [less ▲]

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See detailConfidence Levels for the Cycles Found in Air Temperature Data
Mabille, Georges ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2009, April)

Recently, new cycles have been observed in air temperature data and proxy series using a wavelet-based methodology. Although many evidences attest the validity of this method applied to climatic data, no ... [more ▼]

Recently, new cycles have been observed in air temperature data and proxy series using a wavelet-based methodology. Although many evidences attest the validity of this method applied to climatic data, no systematic study of its efficiency has been carried out. Here, we estimate the confidence levels for this approach and show that the observed cycles are significant. [less ▲]

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See detailDétection des sapovirus porcins par RT-PCR en temps réel
Mauroy, Axel ULg; Scipioni, Alexandra; Mathijs, Elisabeth et al

Poster (2009, April)

Les sapovirus appartiennent à la famille virale des Caliciviridae. Ces virus sont responsables de gastroentérites épidémiques dans l’espèce humaine et sont actuellement majoritairement détectés en Asie ... [more ▼]

Les sapovirus appartiennent à la famille virale des Caliciviridae. Ces virus sont responsables de gastroentérites épidémiques dans l’espèce humaine et sont actuellement majoritairement détectés en Asie. Des souches de sapovirus ont également été isolées dans l’espèce porcine. Trois pays européens seulement ont rapporté la présence de souches de sapovirus porcins dans leurs troupeaux: la Hongrie (Reuter et al., 2007), l’Italie (Martella et al., 2008) et tout récemment la Belgique (Mauroy et al., 2008). La détection moléculaire de la présence de séquences de sapovirus porcins dans des pays où densités d’élevages et de population humaine se conjuguent posent des questions d’ordre zoonotique, problème déjà en discussion pour des virus qui leur sont proches: les norovirus humains et animaux (Scipioni et al., 2008). De plus l’identification de ces nouveaux pathogènes pour l’espèce porcine suggèrent également d’en évaluer les impacts économique, sanitaire et clinique pour cette filière. Ces questions ne pourront être correctement évaluées que si ces virus sont recherchés et que des méthodes fiables de détection sont développées. Dans une précédente étude (Mauroy et al., 2008), le couple d’amorce p289/p290, développé par Jiang et collaborateurs (1999) pour la détection des calicivirus humains (norovirus et sapovirus), avait permis la détection de séquences génomiques de sapovirus et de norovirus porcins. Les amorces p289/290 ont été utilisées dans cette étude dans une RT-PCR en temps réel mettant à profit la technologie SYBR green. L’étude des courbes de dissociation obtenues nous a permis de pouvoir différencier des échantillons de matières fécales positifs pour la présence de séquences génomiques de sapovirus porcins de ceux qui étaient positifs pour la présence de différents calicivirus humains ou animaux (norovirus humains, sapovirus humains, norovirus bovin et porcin, vésivirus félin isolé de tractus respiratoire, vésivirus félin isolé de tractus digestif). Cette méthode devra être dans un premier temps appliquée à un échantillon plus important de matières fécales confirmées positives pour la présence de sapovirus porcins pour pouvoir être validée. La validation de cette méthode pourra ensuite permettre aux laboratoires de diagnostic de disposer d’une méthode rapide et fiable de détection de ces virus dans les filières concernées. [less ▲]

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