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See detailEtude dichronique et historique de l'évolution du trait de côte de la baie de Tanger (Maroc)
El Abdellaoui, Jamal Eddine ULg; Ozer, André ULg

in Télédétection  : Revue de Recherche et d'Application en Télédétection (2007), vol. 7(n° 1-2-3-4), 157-171

The diachronic analysis of air photos and Corona satellite images shows that the erosion of the sandy coast of Tangier bay occurred at variable speeds between 1972 and 1997. The period between 1972-1981 ... [more ▼]

The diachronic analysis of air photos and Corona satellite images shows that the erosion of the sandy coast of Tangier bay occurred at variable speeds between 1972 and 1997. The period between 1972-1981 shows generalized erosion with a rate of 4 m/year. The period of 1981-1997 registers a restoring of the average trend with the formation of three sectors, the first one in erosion with an average rate of 1,5 m/year, the second sector is stable and the third in accretion. Because of its remoteness from the production zones, the sandy beach evolves in a closed system. In fact, on the one hand, the construction of the harbour jetty intercepted the longshore drift generated by the west swell and, on the other hand, the development of the western hillside immobilized the sandy materials that do not contribute anymore to the current solid contribution. Finally, the longshore drift which redistributes the pebbles brought by the oued Halou is broken by the construction of a defence system. The fluvial discharges are henceforth immobilized between the breakwater and the eastern groyne and do not contribute to the sedimentary dynamics. This situation aggravates the impoverishment of the involved sedimentary stock. At present, the erosion that drew sediments of the beach from the most easterly beach to accrete that western portion can’t find more materials because of the erosion and of the quasitotal occupation of the beach. In fact, the western beach not nourished by sediments, will see its vulnerability increase gradually. The repairing of the beach further to successive storms is more difficult. This reality is already felt in 2006. On the other hand, a portion of the clayey coastal cliff of Tangier bay, considered as stable, sustains significant erosion. The mean rate of cliff retreat, recorded between 1981 and 1997, is estimated at 1,5m/year. The reconstructionof the natural coastal system and the monitoring of the successive developments in the bay show that the anthropization of the coast has unbalanced the system in an irreversible way. [less ▲]

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See detailCombination of electrografting and layer-by-layer deposition: an efficient way to tailor polymer coatings of (semi)-conductors
Charlot, Aurélia; Gabriel, Sabine ULg; Detrembleur, Christophe ULg et al

in Chemical Communications (2007), (44), 4656-4658

This communication reports on a novel, simple and highly versatile concept, which consists in combining the advantages of two complementary and relevant techniques (i) electrografting and (ii) layer-by ... [more ▼]

This communication reports on a novel, simple and highly versatile concept, which consists in combining the advantages of two complementary and relevant techniques (i) electrografting and (ii) layer-by-layer deposition process with the goal to tailor strongly adhering coatings to (semi)-conducting surfaces imparting them with tunable specific properties. [less ▲]

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See detailIsolation and identification of inulooligosaccharides resulting from inulin hydrolysis
Ronkart, Sebastien N; Blecker, Christophe ULg; Fourmanoir, Hélène et al

in Analytica Chimica Acta (2007), 604(1), 81-87

In this study, inulooligosaccharides (F-n-type inulin) resulting from the endo-inulinase hydrolysis of globe artichoke inulin were purified and characterized. The aim was to produce F-n oligomer standards ... [more ▼]

In this study, inulooligosaccharides (F-n-type inulin) resulting from the endo-inulinase hydrolysis of globe artichoke inulin were purified and characterized. The aim was to produce F-n oligomer standards with the intention of identifying them in the complex inulin chromatogram. Inulin was extracted from globe artichoke and presented a high average degree of polymerization (DP) of about 80 as determined by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD). This inulin was hydrolyzed by a commercial endo-inulinase yielding a product with a very high F-n/GF(n), molecule ratio, thus limiting the interference of GF(n) during the purification process. High performance size exclusion chromatography was used to individually isolate and collect each retention peak corresponding to a specific oligomer. The purity of these fractions was checked by HPAEC-PAD and showed that relatively pure molecules were produced. Electrospray ionization mass spectrometry allowed the molecular weight determination of these purified oligomers and ascertained their DP as F-2, F-3 and F-4. These F2-4 standards were used with glucose, fructose, sucrose and GF(2-4) (commercially available) to spike commercial oligofructose products in order to determine the elution profile in the HPAEC-PAD chromatogram. [less ▲]

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See detailA dynamic model of an experimental bloom of coccolithophores Emiliania huxleyi
Joassin, Pascal ULg; Borges, Alberto ULg; Chou, Lei et al

Conference (2007, November 27)

A dynamic model has been developed to represent biogeochemical events observed during an experimentally induced bloom of coccolithophores Emiliania huxleyi. This bloom occurred in a mesocosm experiment ... [more ▼]

A dynamic model has been developed to represent biogeochemical events observed during an experimentally induced bloom of coccolithophores Emiliania huxleyi. This bloom occurred in a mesocosm experiment (Bergen 2001 experiment) during which ecosystem development was followed over a 23-days period through changes of the stocks of inorganic nutrients (nitrate, ammonium and phosphate), dissolved inorganic carbon and pCO2, O2 concentration, pigments, particulate organic carbon and nitrogen, dissolved organic carbon, the production of Transparent Exopolymeric Particles (TEP), primary production, alkalinity, calcification and particulate inorganic carbon. The dynamic model is based on unbalanced algal growth and balanced growth for bacteria as described in Van den Meersche et al. (2004). In addition, in order to adequately reproduce the observations, the model has been extended by including an explicit description of calcification, T.E.P production and an enhanced mortality due to viruses. This last process, based on a critical promiscuity between cellular hosts and viral agents, successfully contributed to reproduce the bloom extinction as observed in the mesocosm experiment. This model will be implemented in a coupled physical-biogeochemical model of the Black Sea ecosystem in the framework of the EU Sesame project and in the Gulf of Biscay in the frame of the Belgian PEACE project. [less ▲]

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See detailPrinciples of European Contract Law and Consumer Construction Law
Kohl, Benoît ULg

Conference (2007, November 27)

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See detailAnalysis of ordinal longitudinal data
Donneau, Anne-Françoise ULg

Conference (2007, November 24)

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See detailVers une approche intégrée de la mobilité urbaine
Marchal, Jean ULg; Ndiaye, Alassane-Ballé ULg

in Congrès ISTLS 2007 (2007, November 20)

L’objectif n’est pas de créer un super modèle qui gérerait tous les aspects de la mobilité, mais de faire dialoguer judicieusement les meilleurs modules existants pour chaque aspect de la mobilité ... [more ▼]

L’objectif n’est pas de créer un super modèle qui gérerait tous les aspects de la mobilité, mais de faire dialoguer judicieusement les meilleurs modules existants pour chaque aspect de la mobilité. L’intégration est obtenue par la centralisation via une base de données, ce qui rend possible une vue globale du problème. L'approche repose à la fois sur le traitement et la gestion minutieuse des données grâce à des modules experts dans leur domaine (trafic, émissions polluantes, émissions sonores, aménagement du territoire, juridique, Etc.), en prenant ainsi en compte chaque aspect de la mobilité. L'approche repose à la fois sur le traitement et la gestion minutieuse des données grâce à des modules experts dans leurs domaines (trafic, émission polluante, émission sonore, aménagement du territoire, juridique, etc.), en prenant ainsi en compte chaque aspect de la mobilité. L’approche consiste en l’intégration des données et la communication entre les modules experts existants. L’intégration est obtenue par la centralisation via une base de donnée, ce qui rend possible une vue globale du problème. [less ▲]

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See detailDiet of crustaceans species associated to deep-sea wood falls
Hoyoux, Caroline ULg; Samadi, Sarah; Zbinden, Magali et al

Poster (2007, November 16)

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See detailASSESSMENT OF RETAINED AUSTENITIC PHASE IN INDEFINITE CHILL CAST IRON MICROSTRUCTURE TOWARDS VARIOUS TECHNIQUES
Tchuindjang, Jérôme Tchoufack ULg; Terziev, Liuben; Sinnaeve, Mario et al

Poster (2007, November 16)

Indefinite Chill Cast Irons also called ICDP when used as rolling mill rolls are high alloyed cast iron alloys belonging to the Fe-Cr-C system. ICDP exhibit improved properties regarding hot oxidation and ... [more ▼]

Indefinite Chill Cast Irons also called ICDP when used as rolling mill rolls are high alloyed cast iron alloys belonging to the Fe-Cr-C system. ICDP exhibit improved properties regarding hot oxidation and wear resistances as their microstructure is a mixture of a martensitic with bulky cementite (M3C) and lamellar graphite fully dispersed into the matrix. Mechanical properties involved depend either on the chemical composition of the alloy or the crystallisation behaviour and the heat treatments performed subsequently in order to lead to the desired microstructure. Thus hardenability of the matrix is of great concern as heat treatments sequence is intended to transform austenite in a more stable structure like martensite or even bainite, depending on Cr content. In fact austenite is known to be unstable during hot working conditions as hot temperature and external stresses could yield transformation of this phase into martensite with major volume distortions and even multiple cracks network on the component involved. To avoid such a hitch in service it is quite necessary to make sure all the austenite is completely transformed into martensite while performing subsequent heat treatments like quenching or tempering on the material obtained after casting process. Various techniques are allowable starting from classical ones (X-Ray Diffraction (XRD), Image Analysis, Vibrating Sample Magnetometer (VSM), Dilatometry) to more exotic one like Conversion Electron Mössbauer Spectroscopy (CEMS). From an industrial point of view, it is important to set a fast and reliable method to assess retained austenite presence into ICDP microstructure at the end of any step of the thermomechanical process. The present work is intended to compare different techniques used for retained austenite assessment in ICDP alloys as a first step prior to the calibration of a classical method like dilatometry. This calibration is to be set starting from complex XRD and CEMS spectrometers analyses. Dilatometry seems to overrate retained austenite volume fraction in the as-cast conditions while good agreements are made on the overall batch of techniques when considering heat treated material where retained austenite transformation occurred [less ▲]

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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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