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See detailRelationship between propeptide pH unfolding and inhibitory ability during ProDer p 1 activation mechanism
Chevigné, Andy ULg; Barumandzadeh, Roya ULg; Groslambert, Sylvie et al

in Journal of Molecular Biology (2007), 374(1), 170-185

The major allergen Der p1 of the house dust mite Dermatophagoides pteronyssinus is a papain-like cysteine protease (CA1) produced as an inactive precursor and associated with allergic diseases. The ... [more ▼]

The major allergen Der p1 of the house dust mite Dermatophagoides pteronyssinus is a papain-like cysteine protease (CA1) produced as an inactive precursor and associated with allergic diseases. The propeptide of Der p I exhibits a specific fold that makes it unique in the CA1 propeptide family. In this study, we investigated the activation steps involved in the maturation of the recombinant protease Der p 1 expressed in Pichia pastoris and the interaction of the full-length and truncated soluble propepticles with their parent enzyme in terms of activity inhibition and BIAcore interaction analysis. According to our results, the activation of protease Der p 1 is a multistep mechanism that is characterized by at least two intermediates. The propeptide strongly inhibits unglycosylated and glycosylated recombinant Der p 1 (K-D = 7 nM) at neutral pH. This inhibition is pH dependent. It decreases from pH 7 to pH 4 and can be related to conformational changes of the propepticle characterized by an increase of its flexibility and formation of a molten globule state. Our results indicate that activation of the zymogen at pH 4 is a compromise between activity preservation and propeptide unfolding. (c) 2007 Elsevier Ltd. All rights reserved. [less ▲]

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See detailCompiling polymorphic miRNA-target interactions: the Patrocles database.
Hiard, Samuel ULg; Tordoir, Xavier ULg; Coppieters, Wouter ULg et al

Poster (2007, November 12)

Using positional cloning, we have recently identified the mutation responsible for muscular phenotype of the Texel sheep. It is located in the 3’UTR of the GDF8 gene - a known developmental repressor of ... [more ▼]

Using positional cloning, we have recently identified the mutation responsible for muscular phenotype of the Texel sheep. It is located in the 3’UTR of the GDF8 gene - a known developmental repressor of muscle growth - and creates an illegitimate target site for miRNA expressed in the same tissue. This causes miRNA-mediated translation inhibition of mutant GDF8 transcripts which leads to muscle hypertrophy. We followed up on this finding by searching for common polymorphisms and mutations that affect either (i) RNAi silencing machinery components, (ii) miRNA precursors or (iii) target sites. These might likewise alter miRNA-target interaction and could be responsible for substantial differences in gene expression level. They have been compiled in a public database (“Patrocles”: www.patrocles.org), where they are classified in (i) DNA sequence polymorphisms (DSP) affecting the silencing machinery, (ii) DSP affecting miRNA structure or expression and (iii) DSP affecting miRNA target sites. DSP from the last category were organized in four classes: destroying a target site conserved between mammals (DC), destroying a non-conserved target site (DNC), creating a non-conserved target site (CNC), or shifting a target site (S). To aid in the identification of the most relevant DSP (such as those were a target site is created in an antitarget gene), we have quantified the level of coexpression for all miRNA-gene pairs. Analysis of the numbers of Patrocles-DSP as well as their allelic frequency distribution indicates that a substantial proportion of them undergo purifying selection. The signature of selection was most pronounced for the DC class but was significant for the DNC and CNC class as well, suggesting that a significant proportion of non-conserved targets is truly functional. The Patrocles database allowed for the selection of DSP that are likely to affect gene function and possibly disease susceptibility. The effect of these DSP is being studied both in vitro and in vivo. In conclusion, Patrocles-DSP could be widespread and underlie an appreciable amount of phenotypic variation, including common disease susceptibility. [less ▲]

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See detailPREDetector : Prokaryotic Regulatory Element Detector
Hiard, Samuel ULg; Rigali, Sébastien ULg; Colson, Séverine ULg et al

Poster (2007, November 12)

Background: In the post-genomic area, in silico predictions of regulatory networks are considered as a powerful approach to decipher and understand biological pathways within prokaryotic cells. The ... [more ▼]

Background: In the post-genomic area, in silico predictions of regulatory networks are considered as a powerful approach to decipher and understand biological pathways within prokaryotic cells. The emergence of position weight matrices based programs has facilitated the access to this approach. However, a tool that automatically estimates the reliability of the predictions and would allow users to extend predictions in genomic regions generally regarded with no regulatory functions was still highly demanded. Result: Here, we introduce PREDetector, a tool developed for predicting regulons of DNA-binding proteins in prokaryotic genomes that (i) automatically predicts, scores and positions potential binding sites and their respective target genes, (ii) includes the downstream co-regulated genes, (iii) extends the predictions to coding sequences and terminator regions, (iv) saves private matrices and allows predictions in other genomes, and (v) provides an easy way to estimate the reliability of the predictions. Conclusion: We present, with PREDetector, an accurate prokaryotic regulon prediction tool that maximally answers biologists’ requests. PREDetector can be downloaded freely at http://www.montefiore.ulg.ac.be/~hiard/predetectorfr.html [less ▲]

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See detailLa face cachée des mots du pouvoir
Durand, Pascal ULg

Article for general public (2007)

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See detailTunable random packings
Lumay, Geoffroy ULg; Vandewalle, Nicolas ULg

in New Journal of Physics (2007), 9

We present an experimental protocol that allows one to tune the packing fraction eta of a random pile of ferromagnetic spheres from a value close to the lower limit of random loose packing eta(RLP ... [more ▼]

We present an experimental protocol that allows one to tune the packing fraction eta of a random pile of ferromagnetic spheres from a value close to the lower limit of random loose packing eta(RLP) similar or equal to 0.56 to the upper limit of random close packing eta(RCP) similar or equal to 0.64. This broad range of packing fraction values is obtained under normal gravity in air, by adjusting a magnetic cohesion between the grains during the formation of the pile. Attractive and repulsive magnetic interactions are found to affect stongly the internal structure and the stability of sphere packing. After the formation of the pile, the induced cohesion is decreased continuously along a linear decreasing ramp. The controlled collapse of the pile is found to generate various and reproducible values of the random packing fraction eta. [less ▲]

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See detailLa migration de remontée de l’anguille dans le bassin de la Meuse
Philippart, Jean-Claude ULg; Ovidio, Michaël ULg

Scientific conference (2007, November 07)

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See detailMise en oeuvre d'un outil de suivi des actions d'aménagement : développement de l'amandaie rifaine (Aknoul, Maroc)
Salmon, Marc ULg; Loukili, Mustapha; Abouyaala, Mohamed Abdou et al

in 1eres Journées Scientifiques Inter-Réseaux de l’AUF (2007, November 07)

Afin d’intensifier la production et de lutter contre l’érosion, l’Agence de Promotion et de Développement des Provinces du nord du Maroc (APDN), en collaboration avec le Ministère de l’Agriculture, du ... [more ▼]

Afin d’intensifier la production et de lutter contre l’érosion, l’Agence de Promotion et de Développement des Provinces du nord du Maroc (APDN), en collaboration avec le Ministère de l’Agriculture, du Développement Rural et des Pêches Maritimes, effectuent depuis plusieurs années des plantations dans la région d’Aknoul, au nord du Maroc, réputée pour ses amandiers. Une étude des potentialités des outils tels que les systèmes d’information géographique et la télédétection, au suivi de l’amandaie rifaine a été menée. Le but était d’évaluer l’importance de cette culture dans le secteur d’Aknoul, d’estimer l’état des anciennes et nouvelles plantations et d’orienter les futures actions d’aménagement. [less ▲]

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See detailPEGylated quaternized copolymer/DNA complexes for gene delivery
Vroman, Benoît; Ferreira, Isabel; Jérôme, Christine ULg et al

in International Journal of Pharmaceutics (2007), 344(1-2), 88-95

The aim of this study was to improve the colloidal stability, decrease unspecific interactions with cells and blood components of a novel gene delivery system composed of epsilon-caprolactone and ... [more ▼]

The aim of this study was to improve the colloidal stability, decrease unspecific interactions with cells and blood components of a novel gene delivery system composed of epsilon-caprolactone and quaternized epsilon-caprolactone. For this purpose, diblock 50/50 copolymer was used to generate complexes-with DNA by either the solvent evaporation technique and by dialysis. The size, surface charge and degree of interaction of the plasmid-loaded formulations were measured. Then, polyplexes were combined with a poly(CL)-b-PEG copolymer to create a hydrophilic corona on the surface of the complexes. The cytotoxicity, transfection efficiency and cellular uptake of polyplexes and their association with PEG were evaluated on HeLa cells. The dialysis method did not allow to reduce the size of complexes as compared to the solvent evaporation method. The zeta potential of polyplexes became positive from a charge ratio of 4. The degree of interaction of copolymer with plasmid DNA was very high. Cytotoxicity and transfection efficiency were found to be comparable to polyethylenimine 50 kDa. Association of polyplexes with poly(CL)-b-PEG copolymer led to a small increase in particle size and a sharp decrease of charge surface. Cytotoxicity, transfection efficiency and cellular uptake were significantly reduced relative to unshielded copolymer/DNA complexes. The PEGylated formulations may be an attractive approach for an in vivo application. [less ▲]

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See detailL'astronomie dans le monde
Manfroid, Jean ULg

Article for general public (2007)

Etoiles filantes; Aurigides; 6344 P-L; Japet; Encke perd sa queue; Météo de Titan; Pluton et son cortège; Hipparcos; GMT; Galaxie naine; Galaxies naines primitives; Rayons cosmiques

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See detailEclipse of the B3V companion and flaring of emission lines in V838 Monocerotis
Munari, U.; Corradi, R. L. M.; Henden, A. et al

in Astronomy and Astrophysics (2007), 474

After four years during which only the spectacular light echo was showing continuous and rapid evolution while the central star was nearly constant, in autumn 2006 V838 Mon began a sequence of events ... [more ▼]

After four years during which only the spectacular light echo was showing continuous and rapid evolution while the central star was nearly constant, in autumn 2006 V838 Mon began a sequence of events which profoundly altered its spectroscopic and photometric behavior: (a) an eclipse of the B3V companion, characterized by the disappearance and reappearance of the B3V companion from optical spectra, and an eclipse-like lightcurve of ~70 day duration and Δ B ˜ 1.15 mag, Δ V ˜ 0.55 mag, Δ R[SUB]C[/SUB] ˜ 0.10 mag maximum depth; (b) a large increase in intensity of the [FeII] and FeII emission lines, and the appearance in emission for the first time since the 2002 outburst of Hα and higher Balmer series lines. While the [FeII] and FeII lines maintained a very sharp and unresolved profile, the Hα developed into a wide and structured profile, characterized by a sharp central reversal at the same velocity as one of the CO radio emission components. The disappearance of the B3V companion is equally well explained by a grazing eclipse from the outbursting L-type supergiant or by an eclipse from a dust cloud characterized by E[SUB]B-V[/SUB]=0.55 and R[SUB]V[/SUB]=3.1. We believe the flaring of the emission lines occurred at a similar time as the B3V eclipse just by chance. Tables 2-4 are only available in electronic form at http://www.aanda.org Based on observations made with the Asiago 1.82 m of the INAF Astronomical Observatory of Padova, and with 4.2 m WHT and 2.5 m INT operated by the Isaac Newton Group of Telescopes, and with the 2.6 m NOT operated jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofísica de Canarias. [less ▲]

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See detailPatients infectes par le VIH. Et syndrome lipodystrophique
Uurlings, Françoise ULg; Moutschen, Michel ULg

in Revue Médicale de Liège (2007), 62(11), 669-74

Prolonged utilization of some antiretroviral drugs in patients infected by HIV can lead to the outbreak of a lipodystrophy syndrome. This syndrome is characterized by modification of fats corporal ... [more ▼]

Prolonged utilization of some antiretroviral drugs in patients infected by HIV can lead to the outbreak of a lipodystrophy syndrome. This syndrome is characterized by modification of fats corporal repartition, sometimes associated with metabolic disturbancies (dyslipemia and insulin resistance). Two antiretroviral classes are implicated in the pathophysiology of this syndrome, namely protease inhibitors (PIs) and nucleoside reverse transcriptase inhibitors (NRTIs). The PIs rather influence the differentiation of adipose tissue with its secretion. They are more often associated with visceral adiposity, insulin resistance and dyslipemia. The mitochondrial toxicity of the NRTIs is more frequently responsible for adipose tissue loss at the periphery. Other factors in relation to the patient influence the severity of this syndrome. Several therapeutic options are to be considered both when taking care of the patients suffering from this syndrome and when new patients are to be treated. [less ▲]

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See detailPratiques de commerce et protection du consommateur: la nouvelle donne
Gol, Déborah ULg

in Journal des Tribunaux (2007), 37

La loi du 5 juin 2007 transpose en droit belge la directive 2005/29/CE du 11 mai 2005 relative aux pratiques commerciales déloyales des entreprises vis-à-vis des consommateurs. Elle intègre les ... [more ▼]

La loi du 5 juin 2007 transpose en droit belge la directive 2005/29/CE du 11 mai 2005 relative aux pratiques commerciales déloyales des entreprises vis-à-vis des consommateurs. Elle intègre les modifications issues de la directive dans la loi du 14 juillet 1991 sur les pratiques de commerce, l'information et la protection des consommateurs en en modifiant essentiellement le chapitre VII, anciennement intitulé "Des pratiques contraires aux usages honnêtes". L'article analyse l'origine, le contenu et la portée des modifications apportées à la loi sur les pratiques de commerce. [less ▲]

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See detailCan Forwarding Loops Appear when Activating iBGP Multipath Load Sharing?
Balon, Simon ULg; Leduc, Guy ULg

in Lecture Notes in Computer Science (2007, November), 4866

We analyse the possible consequences of activating iBGP multipath load sharing in a given domain (or AS), which allows for load balancing over multiple exit routers. It has been stated that interdomain ... [more ▼]

We analyse the possible consequences of activating iBGP multipath load sharing in a given domain (or AS), which allows for load balancing over multiple exit routers. It has been stated that interdomain routing loops may appear in this case. We show that under reasonable assumptions (which reflect commercial relationships between ASes) such routing loops cannot appear. Furthermore we show that even if theses assumptions are not met, routing loops can only be transient. [less ▲]

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See detailInterférométrie de speckle en infrarouge thermique
Vandenrijt, Jean-François ULg; Georges, Marc ULg

in Résumés du Huitième colloque francophone Méthodes et Techniques Optiques pour l'Industrie (2007, November)

L’utilisation de l'interférométrie de speckle (ESPI) sur des objets opaques diffusants à une longueur d’onde de 10 µm en utilisant une caméra thermographique commerciale est présentée pour la première ... [more ▼]

L’utilisation de l'interférométrie de speckle (ESPI) sur des objets opaques diffusants à une longueur d’onde de 10 µm en utilisant une caméra thermographique commerciale est présentée pour la première fois à notre connaissance. L’idée d’utiliser une longueur d’onde plus grande que les longueurs d’onde visibles habituelles est de rendre les mesures de déplacements par des techniques holographiques moins sensibles aux perturbations extérieures. Dans cet article, nous discutons certains aspect particuliers dûs à l’accroissement de la longueur d’onde dans le domaine thermique de 10 µm. Nous montrons ensuite les résultats de mesures de rotations dans le plan d’une plaque métallique. Nous avons utilisé la technique du décalage de phase pour obtenir des mesures quantitatives qui sont corrélées par des mesures menées en parallèle avec un théodolite. [less ▲]

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See detailDe l'odeur à la qualité de l'air
Romain, Anne-Claude ULg

Conference given outside the academic context (2007)

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See detailL'image du mois. Hematome spontane du psoas
Robinet, S.; Pappalardo, Eric; Dekoster, Guy ULg et al

in Revue Médicale de Liège (2007), 62(11), 653

Detailed reference viewed: 45 (1 ULg)