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See detailValidation d'une méthode d'analyse quantitative de l'équol dans le lait par UPLC-MSMS
Daems, Frédéric ULg; Jasselette, Christophe; Lognay, Georges ULg et al

Poster (2013, June 04)

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See detailHot gas distribution in the wind of ζ Pup and ζ Ori
Herve, A.; Rauw, Grégor ULg; Nazé, Yaël ULg

Poster (2013, June 01)

We have developped a new X-ray modelling code based on embedded shocks which computes synthetic spectra as a function of plasma temperature, abundances and localization of the X-ray emitting shell in the ... [more ▼]

We have developped a new X-ray modelling code based on embedded shocks which computes synthetic spectra as a function of plasma temperature, abundances and localization of the X-ray emitting shell in the wind. We have also included a proper treatment of the radial dependence of the X-ray opacity of the cool matter as well as a treatment forthe Forbiden Inter combination Resonance (FIR) lines of He-like ions. Our code combines several synthetic spectra in order to fit all the lines of an X-ray spectrum simultaneously and coherently. Our results on two O-type stars ζ Pup and ζ Ori reveal non-porous winds with a mass loss rate consistent with studies in the optical domain as well as non-solar abundances for the CNO elements as expected for evolved stars. More important, the X-ray plasma starts emitting close to the stellarsurface. An improved version of our code allowing an analysis of the radial dependence of the hot gas filling factor reveals for ζ Ori a non continuity of the X-ray emission regions associated to high values of the hot gas filling factor. [less ▲]

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See detailSpectral Modelling with Interaction Effect of the Binary System Spica
Palate, Matthieu ULg; Koenigsberger, G.; Harrington, D. et al

Poster (2013, June 01)

Massive binary systems are crucial to improve our knowledge of the fundamental properties of massive stars, and synthetic spectra modelling with theoretical stellar atmospheres is commonly used in ... [more ▼]

Massive binary systems are crucial to improve our knowledge of the fundamental properties of massive stars, and synthetic spectra modelling with theoretical stellar atmospheres is commonly used in deriving some of these properties. However, the current stellar atmosphere models are designed for single spherical stars and therefore neglect interaction effects that occur in close binaries. We have developed a combined model that uses the TIDES code for computing the surface and the velocity field and the CoMBiSpeC model for the synthetic spectrum computation. This 2-in-1 model allows us to account for the interactions between the stars. We can now simulate the impact of the binarity on the spectra and refine the physical parameters of the binary systems. This model is presented here through the example of the spectral computation of Spica. In this particular system, the strongest effects due to the binarity appear in the line profile variations and the shape of the radial velocity curve. [less ▲]

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See detailThe Chandra Delta Ori Large Project: Occultation Measurements of the Shocked Gas in the Nearest Eclipsing O-Star Binary
Corcoran, Michael; Nichols, Joy; Leutenegger, Maurice et al

Poster (2013, June 01)

Delta Ori is the nearest massive, single-lined eclipsing binary (O9.5 II+OB, P=5.7324d). High resolution X-ray spectrometry offers a unique opportunity to geometrically measure the dynamics of the shocked ... [more ▼]

Delta Ori is the nearest massive, single-lined eclipsing binary (O9.5 II+OB, P=5.7324d). High resolution X-ray spectrometry offers a unique opportunity to geometrically measure the dynamics of the shocked gas around the primary star. We summarize our recent campaign of phase-constrained high-resolution X-ray spectra obtained with the CHANDRA/HETGS plus high-precision photometry with MOST. These observations provide local measurement of the distribution of the embedded, X-ray emitting shocks in the wind of an O star via radial velocity variations and occultation effects, along with standard f/i ratio diagnostics, and enable us to look for correlations with the broad-band photometric variability. We discuss how these observations can help determine the primary star's clumping-corrected mass loss rate, and resolve critical uncertainties in our understanding of the connection between stellar and mass loss parameters. [less ▲]

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See detailChange in viability of Acetobacter senegalensis cells during gluconic acid fermentation at high temperature
Zarmehrkhorshid, Raziyeh ULg; Shafiei, Rasoul ULg; Thonart, Philippe ULg

Poster (2013, June)

Introduction: Gluconic acid (GA) is a multifunctional carbonic acid with versatile applications in food, beverage and pharmaceutical industries. Although the production of GA and its derivative dating ... [more ▼]

Introduction: Gluconic acid (GA) is a multifunctional carbonic acid with versatile applications in food, beverage and pharmaceutical industries. Although the production of GA and its derivative dating backs decades, but use of this acid and its derivatives due to high prices is currently restricted. Using a thermotolerant bacterium in production of this acid at high temperature can provide a new option for industrially cost effective production. However, fermentation productivity may be negatively affected by factors (such as high temperature) leading to loss of cell viability. Objectives: In this study, the ability of a thermotolerant bacterium, Acetobacter senegalensis, in gluconic acid production at high temperature and its survival responses to some factors including temperature and carbon sources were evaluated. Materials and Method: Different batch fermentation processes were carried out at 38 °C, and then cell viability (total dehydrogenase activity) and culturability were assessed using flow cytometry and plate counting techniques, respectively. Results: A. senegalensis oxidized 95 g/L of glucose to gluconic acid at 38 °C. In exponential growth phase, cells were less subjected to damages; but upon transition of cells to stationary phase, cell viability and culturability reduced. Consequently, due to the lack of dehydrogenase activity the specific rate of glucose consumption and gluconic acid production decreased dramatically. High temperature (38 °C), oxidation of high amount of glucose and accumulation of inhibitory compounds (possibly gluconic acid) were dominant inducers leading cells into a viable but non-culturable state (VBNC) during the course of stationary phase. In contrast, presence of ethanol accompanied with glucose, and low incubation temperature assisted in resuscitation of senescent cells of stationary phase. Conclusions: A. senegalensis is able to produce gluconic acid at 38 °C. But, due to entrance of cells into VBNC state during stationary phase, the performance of batch fermentation is adversely affected. [less ▲]

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See detailDo we plagiarize more often when the content of the to-be-remembered material is emotional?
Beaufort, Aline ULg; Brédart, Serge ULg; Perfect, Timothy J. et al

Poster (2013, June)

This study examined the impact of the emotional content on rates of cryptomnesia using the Brown and Murphy (1989) paradigm. In a first stage, dyads of young (mean age = 21.5 years) participants (n = 96 ... [more ▼]

This study examined the impact of the emotional content on rates of cryptomnesia using the Brown and Murphy (1989) paradigm. In a first stage, dyads of young (mean age = 21.5 years) participants (n = 96, 48 females) were asked to generate alternately words corresponding to an emotional category (i.e.,“positive”, “negative” or “neutral”). One week later, participants were instructed (1) to recall the items that were generated by themselves and not by the other member of the dyad (Recall-Own task), (2) to generate four news items (Generate-New task) for each category and (3) to assign confidence ratings to their responses. About 17% of responses were plagiarisms in the recall-own task and the percentage almost reached 9% in the Generate-New task. No significant effects of valence were found on rates of plagiarism in Generate-New task nor on the confidence ratings assigned to the participants' responses. However, cryptomnesia was significantly higher for positive than neutral items while it did not differ significantly across negative and neutral items. Confidence ratings were lower for plagiarized responses than for correct responses but these ratings were higher for plagiarized items than for intrusions. [less ▲]

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See detailROBOT-ASSISTED SURGERY: THE MULTICENTER BELGIAN EXPERIENCE
GOFFIN, Frédéric ULg; Traen, koen; TIMMERMANS, Marie ULg et al

Poster (2013, June)

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See detailTo Be Afraid or to Be Proud? The Impact of Emotional Valence and Response Efficacy on Persuasion in Anti-Drink Driving Advertising
Hazee, Simon ULg

Poster (2013, June)

Social marketers traditionally use negative emotions although they can be ineffective on persuasion. However, few social marketers use positive emotions while commercial marketers use them extensively ... [more ▼]

Social marketers traditionally use negative emotions although they can be ineffective on persuasion. However, few social marketers use positive emotions while commercial marketers use them extensively. Accordingly, this study aims to understand the impact of positive versus negative emotional appeals on persuasion of young adults in a road safety context through a 2 (pride versus fear) × 2 (low versus high response efficacy) factorial design. ANCOVA results show the significant role of both types of emotions on persuasion, regardless the level of response efficacy. Surprisingly, “fear” is more persuasive than “pride”. Hence, social marketers should consider using emotions when building future models and communication campaigns targeting young adults. Future research should investigate under which conditions ‘pride’ can be the most persuasive. [less ▲]

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See detailBrain metabolic dysfunction in Capgras syndrome during Alzheimer’s disease: a positron emission tomography study
Jedidi, Haroun ULg; Daury, Noémy; Cappa, Rémi et al

Poster (2013, June)

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See detailOscillations in the basal ganglia: illustration of a cellular effect at the network level
Dethier, Julie ULg; Drion, Guillaume; Franci, Alessio et al

Poster (2013, June)

Parkinson’s disease (PD) is a neuro-degenerative pathology affecting the basal ganglia (BG), a set of small subcortical nervous system nuclei. The hallmark of the disease is a dopaminergic denervation of ... [more ▼]

Parkinson’s disease (PD) is a neuro-degenerative pathology affecting the basal ganglia (BG), a set of small subcortical nervous system nuclei. The hallmark of the disease is a dopaminergic denervation of the striatum, al- tering information patterns along movement-related ganglia-mediated path- ways in the brain. Severe motor symptoms result from the pathological state: tremor at rest, bradykinesia, akinesia, and rigidity. The transition to the disease state correlates with a switch in the firing mode of the neurons in the BG, from tonic pacemaker activity to burst firing. At the network level, macro-electrode recordings reveal excessive oscillations in the beta (8- 30Hz) frequency band. The oscillations generation mechanism and their functional role remain under debate. We propose a network model where a cellular mechanism controls the dynamical state of the network. In our model, the oscillatory state impacts the neural information processing prop- erties of the network. The network model predicts that a single decrease of the dopaminergic level in the parkinsonnian condition switches the network into an abnormal oscillatory dynamical and globally insensitive state. The brief dopaminergic increase prior to voluntary movements suppresses beta oscillations to drive the network to a conductive state to sensory processing and cognition. [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, June)

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See detailDynamic Modeling and control of a pilot CO2 postcombustion capture plant
Léonard, Grégoire ULg; Cabeza Mogador, Bruno; Belletante, Ségolène et al

Poster (2013, June)

A dynamic model of a post-combustion capture pilot plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A ... [more ▼]

A dynamic model of a post-combustion capture pilot plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A washing section where the flue gas from the absorber is washed with cold water is included to the process in order to reduce the emissions of amine to the air. Control of the water balance in the solvent loop is successfully achieved by changing the washing water temperature. In previous publications regarding CO2 capture pilot plants, the regulation of the water balance always required a water make-up flow which appears here as unnecessary. Rejection of disturbances and different load reduction scenarios are tested to confirm the efficiency of this strategy. Potential operational problems of this control strategy are identified and solved. [less ▲]

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See detailCaracterización de los factores implicados en la resistencia/sensibilidad a la infección del virus influenza en modelos murinos Mx-negativos
Casanova Bustos, Tomas Ronaldo ULg; Daniel, Desmecht; Mutien, Garigliany

Poster (2013, June)

DBA/2J mice and C57BL/6J are two extremes in terms of susceptibility to influenza A virus among Mxnegative mouse strains. Several research teams focused on the factors explaining this difference, mainly ... [more ▼]

DBA/2J mice and C57BL/6J are two extremes in terms of susceptibility to influenza A virus among Mxnegative mouse strains. Several research teams focused on the factors explaining this difference, mainly by genetic approaches using Recombinant Inbred Lines between those two strains. Several candidate-genes have been proposed, but it was not possible to determine their importance. We chose a phenotypic approach, by dissecting each stage of influenza A infection virus in mice of each line, aiming at identifying critical differences between C57BL/6J and DBA/2J. Preliminary observations suggest that either the viral infection of the airway epithelium of DBA/2J is more productive, either alveolar macrophages from C57BL/6J are more efficient in viral particles phagocytosis, or a combination of these two mechanisms. We isolated and cultured tracheal cells, pneumocytes and alveolar macrophages from both strains of mice to determine the permissiveness of the cells of the respiratory tree, quantify the specific receptors of influenza A virus and to compare the alveolar macrophage phagocytic abilities. We have demonstrated a greater presence of α2,3 receptors on alveolar macrophages and tracheal cells of DBA/2J and a higher in vitro viral amplification on DBA/2J respiratory cells. [less ▲]

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See detailIsolation and cultivation of cellulolytic and xylanolytic bacteria and molds extracted from the gut of the termite Reticulitermes santonensis (3DV.1.14)
Tarayre, Cédric ULg; Bauwens, Julien ULg; Mattéotti, Christel et al

Poster (2013, June)

Biofuel production can be based on the use of agro-residues, consisting in a complex lignocellulosic structure which is not easily hydrolysable. The digestive tract of the termite Reticulitermes ... [more ▼]

Biofuel production can be based on the use of agro-residues, consisting in a complex lignocellulosic structure which is not easily hydrolysable. The digestive tract of the termite Reticulitermes santonensis contains a diversified microflora able to hydrolyze the wood components. Bacteria, molds and protists form efficient consortia, able to break the lignocellulosic complex by producing enzymes, such as xylanases and cellulases. Our purpose is the isolation of microbial strains from termite guts in order to evaluate their potential for hydrolysis of lignocellulosic materials. Termites were fed using different diets chosen to improve the xylanolytic and cellulolytic microflora: wood, microcristalline cellulose (added with lignin or not), α-cellulose (added with lignin or not) and birchwood xylan. Then, dissections were realized to isolate the potential xylanolytic and cellulolytic strains. This approach led us to isolate and to study several strains of bacteria (Bacillus sp. strain CTGx and Chryseobacterium sp. strain CTGx) and molds (Trichoderma virens strain CTGx and Sarocladium kiliense strain CTGx). These microorganisms were able to hydrolyze starch, xylan, cellulose, carboxymethylcellulose, esculin, β-glucan and Whatman® filter paper. They can produce glucose and xylose monomers and oligomers which can be further fermented to produce bioethanol. [less ▲]

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See detailResearch of New Enzyme Producing Strains in the Gut of the Termite Reticulitermes santonensis
Tarayre, Cédric ULg; Bauwens, Julien ULg; Mattéotti, Christel et al

Poster (2013, June)

Termites contain a complex microflora inside of their guts. Inferior termites contain bacteria, mycetes and protists that interact to degrade vegetable components. These strains act as consortia to break ... [more ▼]

Termites contain a complex microflora inside of their guts. Inferior termites contain bacteria, mycetes and protists that interact to degrade vegetable components. These strains act as consortia to break natural materials by secreting various enzymes. Our aim was the isolation and cultivation of microorganisms in order to produce new enzymes that can be further used in green chemistry. Termites were fed with different diets: pinewood, microcristalline cellulose (added with lignin or not), α-cellulose (added with lignin or not) and birchwood xylan. Then, dissections were realized to isolate interesting strains. All the microorganisms were subjected to enzyme assays. That technique allowed us to isolate and to cultivate various strains of bacteria, molds and protists. Three strains of bacteria, two strains of molds and one strain of protist were isolated and displayed different enzymatic activities. The bacteria Bacillus subtilis strain ABGx, Bacillus sp. strain CTGx and Chryseobacterium sp. strain CTGx displayed amylase, cellulase and xylanase activities. The molds Trichoderma virens strain CTGx and Sarocladium kiliense strain CTGx were also able to produce those enzymes. However, the protist Poterioochromonas sp. was found to produce only amylase. In conlusion, the termite gut is a complex culivation medium that provides a habitat for many microorganisms that show interesting enzymatic activities. [less ▲]

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See detailMultivariate pattern interpretation using PRoNTo
Schrouff, Jessica ULg; Rosa, Maria; Rondina, Jane et al

Poster (2013, June)

Recently, machine learning models have been applied to neuroimaging data, allowing to make predictions about a variable of interest based on the pattern of activation or anatomy over a set of voxels. In ... [more ▼]

Recently, machine learning models have been applied to neuroimaging data, allowing to make predictions about a variable of interest based on the pattern of activation or anatomy over a set of voxels. In addition, they might lead to an increased sensitivity to detect the presence of a particular mental representation compared to univariate methods such as the General Linear Model (GLM). Application of these methods made it possible to decode the category of a seen object or the orientation of a striped pattern seen by the subject. They also allowed classification of patients and healthy controls and could therefore be used as a diagnostic tool due to their ability to predict the class of an unseen sample. The main disadvantage of multivariate machine learning models is that local inference with respect to the brain neuroanatomy is complex: although linear models generate weights for each voxel, the model predictions are based on the whole pattern and therefore one cannot threshold the weights to make regional statistical inferences as in univariate analysis. In the present work, we developed a methodology based on a labelled anatomical template (e.g. AAL or Brodmann) to display a smoothed version of the model weights and compute a ranking of the regions according their contribution to the predictive model. This work is distributed in PRoNTo (Pattern Recognition for Neuroimaging Toolbox), a user-friendly toolbox, making machine learning models available to every neuroscientist. [less ▲]

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See detailTowards the improvement of a rhizosecretion-based recombinant protein production system: Developing protease-depleted lines of Arabidopsis thaliana.
Lallemand, Jérôme ULg; Désiron, Carole ULg; Périlleux, Claire ULg et al

Poster (2013, June)

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 protein 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 protein 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 aimed at identifying active root-secreted (rhizosecreted) proteases in the model plant Arabidopsis thaliana. Their activity was assayed by in vitro degradation of a target protein (Bovine Serum Albumine, BSA) in a range of pH. The protease classes involved in BSA degradation were evaluated by inhibitor-based assays that revealed serine proteases as the major class involved in this degradation in any tested conditions. As a first step towards identification, and subsequent silencing, of the most active members of this class, rhizosecreted proteases are being analyzed by the “Activity-Based Protein Profiling” approach. [less ▲]

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See detailMaladie hémolytique néonatale modérée due à un anti‐RH46
MONFORT, Mélanie ULg

Poster (2013, June)

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See detailUse of VIS- and nir-infrared spectroscopy to determine cheese properties
Troch, Thibault ULg; Vanden Bossche, Sandrine; De Bisschop, Céline et al

Poster (2013, June)

Cheese processing is one of the possibilities of farm diversification. From 30 cow milks were made 60 cheeses on which several parameters were measured and on which NIR spectra were obtained. Our results ... [more ▼]

Cheese processing is one of the possibilities of farm diversification. From 30 cow milks were made 60 cheeses on which several parameters were measured and on which NIR spectra were obtained. Our results show that cheese spectra could be discriminated between different ripening times of cheeses and the access to pasture or not for the animals which had produced the milk from which the cheese was made. Moreover, highly significant correlations were obtained for the color and the texture of cheeses between the values measured in the laboratory and the NIR spectra. [less ▲]

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See detailA HYDROGEN BOND INFLUENCES THE 5-HT1A/D4 SELECTIVITY OF WAY-100635 ANALOGUES: AN IN SILICO APPROACH
Dilly, Sébastien ULg; Liégeois, Jean-François ULg

Poster (2013, June)

WAY-100635 is widely used in vitro and in vivo as an antagonist of 5-HT1A receptors. In terms of pharmacological tools and pharmacological investigations, the ideal reference molecule would be highly ... [more ▼]

WAY-100635 is widely used in vitro and in vivo as an antagonist of 5-HT1A receptors. In terms of pharmacological tools and pharmacological investigations, the ideal reference molecule would be highly selective for its target over other related and non-related targets. However WAY-100635 displays affinity for and activity at D4 dopamine receptors, and that "off-target" activity confounds its use in pharmacological studies, particularly when both receptors are present. In this context, we carried out various chemical modifications of the WAY-100635 structure in order to improve its 5-HT1A versus D4 selectivity. An important increase of selectivity was obtained when the basic side chain of WAY-100635 was replaced by a 4-phenylpiperazine or a 4-phenyl-1,2,3,6-tetrahydropyridine moiety. In contrast, the introduction of nitrogen atoms in the acyl group decreased the selectivity by reducing the affinity for 5-HT1A receptors, on the one hand, and enhancing the affinity for D4 receptors on the other hand. In order to explain the reduced 5-HT1A/D4 selectivity of aza-derivatives, the binding modes of the compounds were explored by docking analysis on homology models of the two receptors. It appears that the formation of an additional hydrogen bond within D4 receptors could be the key of the decreased selectivity. These results will be very helpful for developing molecules with an improved 5-HT1A/D4 selectivity. [less ▲]

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See detailA nap to recap: Reward strengthens relational memory during daytime sleep
Igloi, Kinga; Gaggioni, Giulia Alice ULg; Eryilmaz, Hamdi et al

Poster (2013, June)

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See detailThe hidden half of flowering
Bouché, Frédéric ULg; Mistiaen, Kevin ULg; D'Aloia, Maria ULg et al

Poster (2013, June)

Flowering is one of the most important developmental steps in plant life cycle and is therefore tightly controlled by environmental cues. The involvement of the aerial part of the plant in the molecular ... [more ▼]

Flowering is one of the most important developmental steps in plant life cycle and is therefore tightly controlled by environmental cues. The involvement of the aerial part of the plant in the molecular mechanisms leading to floral transition is well documented while participation of the roots received less attention. Nevertheless, the induction of flowering by photoperiod is known to involve systemic signals that move in phloem sap towards sinks, throughout the plants, including the roots. Transcriptomic analysis of roots tissues during the floral induction of flowering by a single long day of in Arabidopsis thaliana by a single long day allowed us to identify a large number of differentially expressed genes. How mutations We subsequently selected in some candidate genes affect plant development - including root architecture and flowering time - is being to analyze their flowering timefurther analyzed. Further analysis of those genes will permit us to unravel their role in the flowering induction process. [less ▲]

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See detailConnectome-based classification of BDNF Met allele carriers
Ziegler, Erik ULg; Foret, Ariane; Mascetti, Laura ULg et al

Poster (2013, June)

Secretion of brain-derived neurotrophic factor (BDNF) is essential for synaptic plasticity in the central nervous system during neurodevelopment [Huang]. A common human non-synonymous SNIP in the BDNF ... [more ▼]

Secretion of brain-derived neurotrophic factor (BDNF) is essential for synaptic plasticity in the central nervous system during neurodevelopment [Huang]. A common human non-synonymous SNIP in the BDNF gene (Val66Met, rs6265) decreases activity-dependent BDNF release in neurons transfected with the human A allele (Met-BDNF). We reasoned that the persistent differential activity-dependent BDNF release implied by this polymorphism should also be associated with differences in adult brain structure. The study population comprised 36 healthy subjects (aged 18-25): 15 (9 male) were identified as carrying the Met allele (“Met carrier” group) and 21 (9 male) were homozygotes for the Val allele (“Val/Val” group). The groups did not vary significantly in IQ, age nor scores for a battery of psychological tests. A high-resolution T1-weighted image (sMRI), 7 unweighted (b=0) and a set of diffusion-weighted (b=1000) images using 61 non-collinear directional gradients were acquired for each subject. The processing workflow relied on several pieces of software and was developed in Python and Nipype. The sMRIs were segmented using the automated labeling of Freesurfer [Desikan] and further parcellated using the Lausanne2008 atlas into 1015 regions of interest (ROIs) [Cammoun]. DWIs were corrected for image distortions (due to eddy currents) using linear coregistration functions from FSL [Smith]. Fractional anisotropy maps were generated, and a few single-fiber (high FA) voxels were used to estimate the spherical harmonic coefficients (order 8) of the response function from the DWIs [Tournier]. Then orientation distribution functions were obtained at each voxel. Probabilistic tractography was performed throughout the whole brain using seeds from subject-specific white-matter masks and a predefined number of tracts (300,000), see Fig. 1. The tracks were affine-transformed into the subject's structural space with Dipy [Garyfallidis]. Connectome mapping was performed by considering every contact point between each tract and the outlined ROIs (unlike in [Hagmann]): the connectivity matrix was incremented every time a single fiber traversed between any two ROIs. We trained a Gaussian Process Classifier [Rasmussen] (interfaced by PRoNTo [Schrouff]) on these connectivity matrices. The accuracy and generalization ability of the classification were assessed with a leave-one-subject-out cross-validation procedure. With this linear kernel method weights were also obtained indicating the contribution to the classification output (in favor of either genotypic group) of each edge in the network. The same method was employed to discriminate features related to the subjects' gender and genotype for the ADA gene. The classifier was able to discriminate between Val/Val and Met carriers with 86.1% balanced accuracy. The predictive value for the Val/Val and Met carrier groups were 94.4% (p=0.001) and 77.8% (p=0.003), respectively. In Fig. 2 the weights obtained by the classifier are visualized as edges in the brain network. For the classifier trained to identify gender or the subjects' ADA genotype, the global accuracy reached 63.9% (n.s.) and 58.3% (n.s.) respectively. Using high-resolution connectome mapping from normal young healthy human volunteers grouped based on the Met allele of the BNDF gene, we show that the BDNF genotype of an individual can be significantly identified from his structural brain wiring. These differences appear specific to this allele; no such difference could be found for the polymorphism in the ADA gene, or even for gender. We propose that the decreased availability of BDNF leads to deficits in axonal maintenance in Met carriers, and that this produces mesoscale changes in white matter architecture. Acknowledgements: the FNRS, the ULg, the Queen Elisabeth Medical Foundation, the Léon Fredericq Foundation, the Belgian Inter-University Attraction Program, the Welbio program, and the MCITN in Neurophysics (PITN-GA-2009-238593). Cammoun L. et al. (2011), ‘Mapping the human connectome at multiple scales with diffusion spectrum MRI’, J Neuroscience Methods, 203:386–397. Desikan R.S. et al. (2006), ‘An automated labeling system for subdividing the human cerebral cortex on MRI scans into gyral based regions of interest’, Neuroimage, 31:968-980. Hagmann P. et al. (2008), ‘Mapping the structural core of human cerebral cortex’, PLoS Biology, 6:e159 Huang E.J., Reichardt L.F. (2001), ‘Neurotrophins: roles in neuronal development and function’, Annual Review of Neuroscience, 24:677-736. Garyfallidis E. et al. (2011), ‘Dipy - a novel software library for diffusion MR and tractography’, 17th Annual Meeting of the Organization for Human Brain Mapping. http://nipy.sourceforge.net/dipy/ Rasmussen C.E. (2006), Gaussian processes for machine learning. Schrouff J. et al. (2012), ‘PRoNTo: Pattern Recognition for Neuroimaging Toolbox’, 18th Annual Meeting of the Organization for Human Brain Mapping. http://www.mlnl.cs.ucl.ac.uk/pronto Smith S.M. et al. (2004), ‘Advances in functional and structural MR image analysis and implementation as FSL’, Neuroimage, 23 Suppl 1:S208-S219. Tournier J.D., et al. (2007), ‘Robust determination of the fibre orientation distribution in diffusion MRI: non-negativity constrained super-resolved spherical deconvolution’, Neuroimage, 35:1459-1472. [less ▲]

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See detailA Pathway closely related to the D-tagatose pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis
Van Der Heiden, Edwige ULg; Delmarcelle, Michaël ULg; Lebrun, Sarah ULg et al

Poster (2013, June)

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium ... [more ▼]

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. [less ▲]

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See detailAu delà des nombres réels
Kreusch, Marie ULg

Poster (2013, June)

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See detailBiomass hydrolyzing enzymes identified by functional screening of a metagenomic library from algal biofilms.
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2013, June)

Biomass hydrolyzing enzymes are increasingly searched for the production of biofuels and renewable chemical compounds using biomass. Microorganisms living on algaes are an interesting reservoir of biomass ... [more ▼]

Biomass hydrolyzing enzymes are increasingly searched for the production of biofuels and renewable chemical compounds using biomass. Microorganisms living on algaes are an interesting reservoir of biomass hydrolyzing enzymes, as they are in constant interaction with algal biomass. Therefore, we are interested in looking for some of those enzymes synthesized by the microflora living on the surface of the brown algae Ascophyllum nodosum. Algae samples were collected in the winter 2012 and a microbial DNA extraction method was developed. The whole extracted microbial genomes of the microorganisms living on the algae were restricted, inserted in a cloning vector and ligated products were used for transformation of cultivable Escherichia coli host cells. This metagenomic library was then screened for diverse enzymatic activities (lipolytic enzymes, cellulases, beta-glucosidases, alpha-amylases, arabinanases, xylanases and proteases) on agar plates with specific substrates. Five putative lipolytic enzymes, one cellulase and one beta-glucosidase were identified. Sequence analysis revealed low (<50%) sequence identities with known enzymes sequences, meaning new enzymes from unknown genomes have been discovered. To our knowledge this is the first functional screening that was realized with a metagenomic library from algal biofilms and this is the first cellulase identified by marine metagenomics. A second library has been constructed from algae sample from summer 2012 and is currently being screened. New enzymatic tests are being developed for the identification of enzymes degrading specific algal polysaccharides like agarases, carrageenases, alginate lyases, laminarinases,… Those very specific enzymes aren’t well known yet, and our metagenomic approach will probably help us to identify new families and structures of those algal biomass hydrolyzing enzymes. [less ▲]

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See detailValidation of an accelerometer-based approach to quantify gait events
Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg; Stamatakis, Julien et al

Poster (2013, June)

Researchers rarely provide solid performance and validation information about their acceleometer-based approaches to human gait analysis. We present here a novel signal processing and analysis algorithm ... [more ▼]

Researchers rarely provide solid performance and validation information about their acceleometer-based approaches to human gait analysis. We present here a novel signal processing and analysis algorithm that automatically extracts four consecutive fundamental events of walking: heel strike (HS), toe strike (TS), heel off (HO), and toe off (TO). In addition, we validate this accelerometer-based technique by comparing these extracted gait events with those obtained by a kinematic 3D analysis system and a force plate, used as gold standards. [less ▲]

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See detailAnalysis of the interactions of xylose-based bolaforms with model membranes
Nasir, Mehmet Nail ULg; Monhonval, Pierre; Legrand, Vincent et al

Poster (2013, June)

Sugar-based surfactants are natural and biocompatible compounds. Among sugar-based surfactants, there is an increase of interest for the xylose-based bolaforms because of their potential applications in ... [more ▼]

Sugar-based surfactants are natural and biocompatible compounds. Among sugar-based surfactants, there is an increase of interest for the xylose-based bolaforms because of their potential applications in pharmaceutical and cosmetic fields and of their original physicochemical properties. Xylose-based bolaforms have interfacial and membrane-interacting properties making them potential molecules for drug delivery systems. For this work, we chemically synthetized by metathesis in the presence of Grubbs I catalyzer, a novel symmetric bolaform composed of two xylose polar heads connected by an ether link to a hydrocarbon chain having 18 carbon atoms with an unsaturation (BolaX). We were able to obtain two bolaforms differing only at the level of the anomeric configuration of the xylose moieties, or orBolaX). The surface activities of both compounds were analyzed. The anomeric configuration  gives interfacial properties at the air-water interface contrary to the  one. The interactions of the BolaX with model membranes were then analyzed in order to determine if it can be used for drug delivery systems. Our results show that BolaX were able to interact and insert within lipid monolayers containing phospholipids and sterols. In order to have informations at the molecular level of these interactions, another model membrane, called multilamellar vesicles (MLVs), containing phospholipids and sterols with or without  BolaX were prepared. Both MLVs were analyzed by the means of the FTIR spectroscopy. In parallel, we have calculated the interaction energy of the  BolaX with different lipid molecules by the means of the Hypermatrix method developed at our laboratory. Moreover, the insertion of the  BolaX within the lipid bilayers was simulated using our IMPALA method. Taking together, our findings indicate that BolaX would be a potential candidate for drug delivery systems because of its surface active properties and its ability to insert within membranes. [less ▲]

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See detailIMMUNE AND NEURO-ENDOCRINE RESPONSES OF GRAVID EURASIAN PERCH TO CHRONIC CONFINEMENT AND SOCIAL ISOLATION STRESS
Mandiki, SMN; Douxfils, Jessica; Massart, Sophie et al

Poster (2013, June)

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See detailLack of generalization as explicative factor of morphosyntactic difficulties in children with SLI: a longitudinal study
Leroy, Sandrine ULg; Parisse, Christophe; Marchat, Aurélie et al

Poster (2013, June)

Background. Constructivist approach (Goldberg, 2006; Tomasello, 2003) postulates that children build their linguistic system from their own linguistic experience. To be productive with their language ... [more ▼]

Background. Constructivist approach (Goldberg, 2006; Tomasello, 2003) postulates that children build their linguistic system from their own linguistic experience. To be productive with their language, children have to generalize construction schemas to never heard items. Because children with SLI show limited morphosyntactic creativity and variability, we hypothesized that they would have difficulties to generalize their construction schemas, which would hinder their access to the most abstract level of the linguistic competence. Our aim was to test whether children with SLI had more difficulties than children with TLD to generalize a schema to new items. Methods. Seven children with SLI matched with 6 children TLD based on linguistic age were recorded for this study. Two steps were repeated at three different moments spread out three years. The first step consisted in a recording of a parent/child interaction at their house. All interactions were transcribed and analyzed. The second step consisted in the creation of two tasks from each child’s own productions: an utterance repetition task and a priming task. Tasks were individualized. Items were created from schemas considered as “acquired” and schemas considered as “non-acquired”. Results. Priming task. Current statistical analyses revealed a significant “Group” effect, a significant “Time” effect and a no significant “Group” by “Time” effect. Analyses revealed a significant “Structure” effect and a significant “Group” by “Structure” effect. Difference between the two groups was more marked for items with “non-acquired” schemas. Repetition task. The same results were obtained; except for “Time” variable (no significant effect). Discussion. The two groups had more difficulties to generalize non-acquired schemas to new items, but children with SLI seemed to have more difficulties, which could mean that their productivity with new schemas was more hindered. Consequently, results are compatible with our hypothesis suggesting that children with SLI have more difficulties for generalizing a schema to new items. [less ▲]

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See detailUnravelling the roles of lysine acetylation by Elp3 during inner ear development
Mateo Sanchez, Susana ULg; Delacroix, Laurence ULg; Laguesse, Sophie ULg et al

Poster (2013, May 31)

Given the importance of acetylation homeostasis in controlling developmental processes, we planned to investigate its role in inner ear formation and focused our attention on Elp3 acetyl-transferase, a ... [more ▼]

Given the importance of acetylation homeostasis in controlling developmental processes, we planned to investigate its role in inner ear formation and focused our attention on Elp3 acetyl-transferase, a member of the Elongator complex recently implicated in neurogenesis. We first analysed the spatio-temporal pattern of ELp3 mRNA expression and showed that it was expressed in the early otocyst at E11.5 and persisted later in the sensory epithelium of the cochlea, the spiral ganglion, the stria vascularis and the vestibule. To unravel functions of Elp3 in the inner ear, we used conditional knock-out mice in which Elp3 gene is deleted from early otocyst (Elp3 cKO). We submitted these mice to a battery of vestibular testing and found significant abnormalities. Besides, the auditory brain stem response of Elp3 cKO indicated that these mice are severely deaf. At the cellular level, we detected some defaults in the planar orientation of the auditory hair cell bundle. In addition, the length of the kinocilium was significantly reduced both in vestibular and cochlear hair cells from Elp3 cKO mice. We were also able to demonstrate an increased level of apoptosis in the Elp3 cKO spiral ganglion at E14.5 leading to a reduced number of fibers innervating the cochlear hair cells as well as a reduced number of their synaptic ribbons. In conclusion, our results clearly show a role for Elp3 both in hearing and balance. We plan to go deeper in the mechanisms involved through the identification of the proteins that are targeted for acetylation by Elp3. [less ▲]

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See detailIn vitro and in vivo Characterization of Adult Bone Marrow Neural Crest Stem Cells
Coste, Cécile ULg; Neirinckx, Virginie ULg; Manguette, Jérôme et al

Poster (2013, May 31)

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See detailOsmotic dehydration of pomegranate seeds (PUNICA GRANATUM L.)
Bchir, Brahim ULg; Besbes, Souhail; Attia, Hamadi et al

Poster (2013, May 30)

Osmotic dehydration of pomegranate seeds was carried out at different temperatures (30, 40, 50°C) in a 55°Brix solution of sucrose, glucose, and mixture sucrose & glucose (50:50 wt/wt). The most ... [more ▼]

Osmotic dehydration of pomegranate seeds was carried out at different temperatures (30, 40, 50°C) in a 55°Brix solution of sucrose, glucose, and mixture sucrose & glucose (50:50 wt/wt). The most significant changes of water loss and solids gain took place during the first 20 min of dewatering. During this period, seeds water loss was estimated to 46% in sucrose, 37% in glucose and 41% in mix glucose/sucrose solution. The increase of temperature favoured the increase of water loss, weight reduction, solids gain and effective diffusivity. Differential scanning calorimetry data provided complementary information on the mobility changes of water and solute in osmodehydrated pomegranate seeds. The ratio between % frozen water and % unfreezable water decreased from 5 to 0.5 during the process. That involving the presence of very tightly bound water to the sample, which is very difficult to eliminate with this process. It also appeared that glass transition temperature depends on the types of sugar. [less ▲]

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See detailINFUSION OF THIRD-PARTY MESENCHYMAL STEM CELLS (MSC) AFTER KIDNEY AND LIVER TRANSPLANTATION: A PHASE I-II, OPEN-LABEL, CLINICAL STUDY (EudraCT 2011-001822-81 & NCT01429038)
DETRY, Olivier ULg; DELBOUILLE, Marie-Hélène ULg; LECHANTEUR, Chantal ULg et al

Poster (2013, May 30)

MSC cells have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aims to be the first evaluation of the safety and tolerability of third party MSC ... [more ▼]

MSC cells have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aims to be the first evaluation of the safety and tolerability of third party MSC infusion after cadaveric kidney and liver transplantation in a prospective phase I-II study, taking advantage of our centre expertise and experience in MSC use in graft-versus-host disease (GVHD) after bone marrow transplantation and using an already functioning GMP-compliant laboratory producing clinical-grade MSC. Secondary end-points will help to evaluate the immunosuppressive potential of MSC after organ transplantation, and the opportunity to develop larger randomised, controlled, phase III trials. After successful transplantation, 10 liver and 10 kidney transplant recipients under standard immunosuppression (tacrolimus, MMF, steroids) will receive an intravenous infusion of 1.5-3x106/kg of third-party MSC on post-operative day 3±2. These patients will be prospectively compared to 10 liver and 10 kidney recipients who meet the inclusion criteria but deny MSC infusion. Safety will be assessed by recording side effects, including opportunistic infections and cancers. Immunosuppressive potential will be evaluated by rejection episode rates, by graft/patient survivals, by immunohistology of 3-months kidney and 6-month liver graft biopsies and by in vitro evaluation of the immunity profile of the recipients. In a second step, reduction (kidney) and progressive weaning (liver) of immunosuppression will be attempted in recipients who received MSC. This ongoing study is supported by research grants from the CHU of Liège, University of Liège, and by the Senior Clinical Research Grant from ESOT. The first patients were included and treated in early 2012, and final results expected in late 2013. [less ▲]

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See detailNovel phenolic glycolipids: antioxidant activity and effect on membrane models
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Draguet, Florian et al

Poster (2013, May 30)

Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B ... [more ▼]

Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory 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 regards to their aromatic group.Theireffect on cell viability when an oxidative stress is induced was tested. In parallel, their interaction with cell models (liposomes) was studied through membrane fusion and permeability experiments. [less ▲]

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See detailUne méthode d’implantation de tours pour favoriser leur insertion dans le tissu urbain
Saint-Pierre, Claire ULg; Becue, Vincent; Diab, Youssef et al

Poster (2013, May 30)

La question de la verticalité est récemment revenue parmi les préoccupations et débats d'experts de la ville. Les tours continuent de faire l'objet de controverses mais la volonté de les utiliser comme ... [more ▼]

La question de la verticalité est récemment revenue parmi les préoccupations et débats d'experts de la ville. Les tours continuent de faire l'objet de controverses mais la volonté de les utiliser comme outil de développement urbain durable demeure. En France, le processus décisionnel de la construction des tours est linéaire et prend en considération relativement tard, les critères nécessaires à une bonne qualité d'insertion urbaine. L'article propose une méthode d'implantation de tours plus globale, permettant d'évaluer l'insertion urbaine d'une tour par rapport à son environnement ainsi que d'accompagner les acteurs impliqués dans leur prise de décision. [less ▲]

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See detailCombination of actor's play training and assertiveness program to reduce difficulties in self-affirmation: A preliminary study.
Wagener, Aurélie ULg; Delvaux, Muriel ULg; Sarto, Danielle et al

Poster (2013, May 28)

BACKGROUND. Difficulties in assertiveness are often reported by individuals suffering from various psychological problems involving anxiety, depression. Cognitive and behavioral therapeutic procedures ... [more ▼]

BACKGROUND. Difficulties in assertiveness are often reported by individuals suffering from various psychological problems involving anxiety, depression. Cognitive and behavioral therapeutic procedures have already proven their effectiveness in helping these patients. The aim of our study was to test the efficacy of new therapeutic procedure, inspired by the third wave of behavioral and cognitive psychotherapies. METHOD. Our study used an actor’s play training combined with an assertiveness program which comprised ten sessions: five of which were animated by an actress and five by a psychologist-psychotherapist. Each actor play’s session was given alternatively with a psychoeducation’s session. Twenty subjects participated in this program. They fulfilled these pre and post-test assessments: social self-efficacy questionnaire, self-affirmation scales, self-esteem scale, communication scale, anxiety and depression scales. Repeated measures’ ANOVAs have been used to compare pre and post-test results. RESULTS. Results showed statistically significant improvements on each dependent variable, except for the Communication Scale. The higher effects appeared for Beck Depression Inventory and Social Self-efficacy Questionnaire which presented an effect size of 0,74 and 0,56, respectively. Scores on STAI-A and B and on Self-affirmation Scale were over the effect size’s threshold. However, these improvements don’t attain control group’s scores reported in the scientific literature. DISCUSSION. The results highlighted that our program is effective in reducing difficulties in assertiveness. [less ▲]

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See detailPsychosocial needs and perception of inequity: How spouses react to the cancer of their partner?
Wagener, Aurélie ULg; Bragard, Isabelle ULg; Jonius, Bénédicte et al

Poster (2013, May 28)

Background. Several studies have highlighted the importance of psychosocial needs in cancer patients’ spouses. Our study’s aim was to reduce these spouses’ needs, using a combination of two ... [more ▼]

Background. Several studies have highlighted the importance of psychosocial needs in cancer patients’ spouses. Our study’s aim was to reduce these spouses’ needs, using a combination of two psychotherapeutic methods: 1. Psychosocial needs’ organization into a hierarchy; 2. Problem-solving method. We also assessed perception of inequity, which is a new concept used in psycho-oncology. This perception focusses on two feelings that spouses might experience in their relationships: firstly, the feeling of overbenefit and underinvestment; secondly, the feeling of underbenefit and overinvestment. Method. A longitudinal design with three assessments (T0,T1,T2) and two groups (experimental, control) was employed. Spouses fulfilled questionnaires: socio-demographic questionnaire, Psychosocial Needs Inventory, Perception of Inequity, Hospital Anxiety and Depression Scale. At T0, all participants organised their psychosocial needs into a hierarchy. Experimental group practiced problem-solving method before control group. Indeed, experimental group practiced it between T0 and T1 while control group practiced it only between T1 and T2. Results. Thirty-seven spouses participated: N experimental group=19; N control group=18. Whenever the combination was given, repeated measures’ ANOVAs highlighted a significant decrease in unsatisfied psychosocial needs when participants have received both methods. Nevertheless, our results did not replicate previous findings according to which spouses experience a higher feeling of overinvestment and underbenefit than feeling of underinvestment and overbenefit. Discussion. Our results underline the interest of proposing psychotherapeutic methods to cancer patients’ spouses to reduce unsatisfied psychosocial needs. [less ▲]

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See detailThe experience of chronic illness and psychopathology across the life stories: The case of hemophilic boys, obese adolescents and depressive hospitalized adolescents.
Jadin, Aurore ULg; Boulard, Aurore ULg

Poster (2013, May 28)

During an individual semi-structured interview, based on Mc Adams’ wor ks, each teenager’s life story was collected. Different measures were taken. CESD was used to identified depre ssed adolescents among ... [more ▼]

During an individual semi-structured interview, based on Mc Adams’ wor ks, each teenager’s life story was collected. Different measures were taken. CESD was used to identified depre ssed adolescents among sample. In all, we interviewed 66 adolescents. Each personal narrative was then retr anscribed and encoded. Finally, discursive analysis and textual data analysis softwares were used to examine the data base [less ▲]

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See detailInteraction between short-term and long-term memory in the musical domain: the impact of musical knowledge and musical expertise
Gorin, Simon ULg; Majerus, Steve ULg

Poster (2013, May 28)

While verbal short-term memory (STM) has received considerable research interest, STM for music has been given considerably less attention. The aim of this study is to show that STM for musical stimuli is ... [more ▼]

While verbal short-term memory (STM) has received considerable research interest, STM for music has been given considerably less attention. The aim of this study is to show that STM for musical stimuli is grounded in LTM, as has been shown for verbal STM. Interactions between LTM and musical STM were studied by exploring the impact of musical knowledge and musical expertise on STM performance. The role of musical knowledge was investigated by an implicit musical learning task, where participants were incidentally exposed to a sequence of tones whose succession was governed by an artificial musical grammar; after exposure, a musical STM task was presented where participants had to reproduce tone sequences of increasing length, half of the sequences being legal (obeying to the artificial musical grammar of the incidental learning task). The role of musical expertise was explored by administering the same task to two participant groups: adults with no musical training and adult musicians. For the role of newly acquired musical knowledge, the non-musician participants showed a significant advantage for reproducing legal musical sequences, showing that they had incidentally learned new musical knowledge and that this knowledge supports STM performance. The musicians did not present an incidental musical learning effect in STM recall, but overall outperformed the non-musicians for reproducing both legal and illegal tone sequences, showing an overall effect of musical expertise. This study is the first to document STM-LTM interactions in the musical domain, and this for both new and existing musical knowledge. [less ▲]

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See detailCharacterization of the zebrafish beta-cell transcriptome by RNA-seq
Manfroid, Isabelle ULg; Tarifeno, Estefania; Voz, Marianne ULg et al

Poster (2013, May 27)

The loss of pancreatic insulin-producing cells (beta-cells) is a hallmark of diabetes and more knowledge is needed to find new treatments. Thus, it is crucial to identify novel regulatory genes ... [more ▼]

The loss of pancreatic insulin-producing cells (beta-cells) is a hallmark of diabetes and more knowledge is needed to find new treatments. Thus, it is crucial to identify novel regulatory genes specifically expressed in this pancreatic cell subtype. In the present study, the main pancreatic islet was dissected from transgenic Tg(insulin:GFP) adult zebrafish and beta-cells were selectively recovered by FACS with 98% of purity. Illumina RNA-seq was used to sequence the transcriptome. 20 millions of sequenced reads (paired-end) were obtained, aligned on the zebrafish genome and assembled into transcripts (Tophat/Cufflinks softwares). The zebrafish beta-cells transcriptome includes all known regulatory genes involved in beta-cell differentiation such as pdx1, mnx1, pax6b, neuroD, isl1, insm1, as well as Hopx and Hdac9 genes, both recently identified in human beta-cells. In contrast, the alpha-cell specific transcription factor arx and the acinar marker ptf1a were not detected, confirming the high purity of our beta-cell preparation. Interestingly, many miRNAs were detected, such as dre-mir-375 and dre-mir-7, as well as several lncRNA recently described at embryonic stages. We are currently applying the same approach to the Tg(somatostatin:GFP) and Tg(glucagon:GFP) transgenic lines in to characterize the transcriptome of delta- and alpha-cells. The comparison of these different data will allow us to identify coding and non-coding genes specifically expressed in the different endocrine subtype cells, paving the way for further functional studies. [less ▲]

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See detailLesion size effect on variability in PET quantification in multicenter trials
Guiot, Thomas; Vanderlinden, Bruno; Seret, Alain ULg et al

Poster (2013, May 25)

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See detailEnergy spectrum and point spread function comparison of pin-hole and parallel-hole collimators for 90Y bremsstrahlung imaging
Walrand, Stephan; Hesse, Michel; Seret, Alain ULg et al

Poster (2013, May 25)

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See detailDevelopment of a quantitative approach to measure phospholipids in dried drops by Raman spectroscopy
Malherbe, Cédric ULg; Jadoul, Laure ULg; Gilbert, Bernard ULg et al

Poster (2013, May 24)

Phospholipids, PL, such as the phosphatidylcholine PC(18:0/18:1), play a role in the structure of living cells and are suspected to be part of the development of some diseases, for example cancers. Mass ... [more ▼]

Phospholipids, PL, such as the phosphatidylcholine PC(18:0/18:1), play a role in the structure of living cells and are suspected to be part of the development of some diseases, for example cancers. Mass spectrometry enables the structural analysis of PL in complex biological media but imaging mass spectrometry by MALDI-MS is rather limited for quantification purposes. Complementarily, Raman spectroscopy as a non invasive and non destructive method is a potential candidate to quantify and visualise the spatial distribution of the PL by molecular imaging. Unfortunately, the lack of specific chemical function in PL, compared to others biomolecules, limits the use of Raman spectroscopy in the identification process of those PL in complex biological samples. The results presented here belong to a first study of the application of the Raman analyses on dried residues of PL and mice brain tissue performed in the lab. [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)

Detailed reference viewed: 27 (3 ULg)
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 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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Peer Reviewed
See detailEndothelium-specific expression of the microRNA miR-146a by using the RCAS system
Fontaine, Marie ULg; Halkein, Julie; Tabruyn, Sébastien et al

Poster (2013, May 17)

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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 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 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 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 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 ▲]

Detailed reference viewed: 42 (23 ULg)