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See detailL’Okeanos végétalisé. Elaboration d’un thème iconographique
Derwael, Stéphanie ULg

Scientific conference (2012, November 16)

L’important développement que connaît la figure du dieu Océan dans la littérature latine du Ier siècle apr. J.-C., est contemporain de l’émergence d’un nouveau type iconographique : l’Okeanos végétalisé ... [more ▼]

L’important développement que connaît la figure du dieu Océan dans la littérature latine du Ier siècle apr. J.-C., est contemporain de l’émergence d’un nouveau type iconographique : l’Okeanos végétalisé. Cette innovation romaine s’impose rapidement comme la formulation plastique de son rôle de divinité primordiale, pourvoyeuse de toute vie et garante de prospérité. Le motif connaît alors une longue postérité dans l’art romain, où son utilisation semble répondre à certains schémas codifiés. L’étude de son cheminement nous mènera à travers des supports aussi variés que la mosaïque, la sculpture ou encore la céramique, et permettra ainsi de mieux comprendre les différentes phases d’élaboration et de diffusion d’un thème iconographique, de sa naissance à sa dissolution. [less ▲]

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See detailOkri, Ben (1959-)
Tunca, Daria ULg

in Juang, Richard M.; Morrissette, Noelle (Eds.) Africa and the Americas: Culture, Politics, and History (2008)

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See detailOld and new issues in differential item functioning (DIF): How to overcome current research conservatism?
Magis, David ULg

Scientific conference (2010, October 05)

In the context of differential item functioning (DIF), some issues have been pointed out more than 20 years ago, whereas other ones have appeared much more recently (often due to an incredible increase of ... [more ▼]

In the context of differential item functioning (DIF), some issues have been pointed out more than 20 years ago, whereas other ones have appeared much more recently (often due to an incredible increase of available information). In addition, there is some uprising evidence that the topic of DIF is becoming less attractive for journal editors. Explaining the reasons for this lack of interest in DIF, and why it should be actively countered, are the main goals of this talk. Three specific issues will be discussed: (a) the supremacy of the Mantel-Haenszel method, (b) the problem of item purification, and (c) the identification of DIF among multiple groups. Some recent and ongoing research results will be discussed to highlight why DIF should not be left alone in the years to come. [less ▲]

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See detailOld Cairo Development Project
Attia, Shady ULg; Zakareya, Mona

Diverse speeche and writing (2003)

Article about the development of Old Cairo, the historic centre in Cairo, Egypt. (arabic).

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See detailThe Old English copula weorðan and its replacement in Middle English
Petré, Peter ULg; Cuyckens, Hubert

in Gotti, Maurizio; Dossena, Marina; Dury, Richard (Eds.) English historical linguistics 2006. Volume I Historical syntax and morphology. Selected papers from the fourteenth International Conference on English Historical Linguistics (ICEHL 14), Bergamo, 21-25 August 2006 (2008)

With the aid of a specially compiled corpus, this paper accounts for the replacement – mainly by become – of weorðan ‘become’, whose use rapidly decreased in Middle English. Drawing on Goldbergian ... [more ▼]

With the aid of a specially compiled corpus, this paper accounts for the replacement – mainly by become – of weorðan ‘become’, whose use rapidly decreased in Middle English. Drawing on Goldbergian construction grammar, the paper posits the existence of a lexeme-independent network of copular constructions [Copula + np/ap/…]. Copular uses of weorðan are associated with this network, but also form part of a second network exclusive to weorðan, which, already in Old English, served as a model for the extension of becuman to copular uses. In early Middle English, weorðan reacted to changes in the lexeme-independent copular network. Weorðan was no longer used with adjectival participles when these were constructionally separated from its most frequent collocates, namely human propensity adjectives. Furthermore, reacting to an influx of various adjectives in predicate position, becuman, which had no collocational preferences, extended its use to these adjectives and eventually took over from weorðan completely. [less ▲]

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See detailThe Old Halo metallicity gradient: the trace of a self-enrichment process
Parmentier, Geneviève ULg; Jehin, Emmanuel ULg; Magain, Pierre ULg et al

in Astronomy and Astrophysics (2000), 363

Based on a model of globular cluster self-enrichment published in a previous paper, we present an explanation for the metallicity gradient observed throughout the galactic Old Halo. Our self-enrichment ... [more ▼]

Based on a model of globular cluster self-enrichment published in a previous paper, we present an explanation for the metallicity gradient observed throughout the galactic Old Halo. Our self-enrichment model is based on the ability of globular cluster progenitor clouds to retain the ejecta of a first generation of Type II Supernovae. The key point is that this ability depends on the pressure exerted on the progenitor cloud by the surrounding protogalactic medium and therefore on the location of the cloud in the protoGalaxy. Since there is no significant (if any) metallicity gradient in the whole halo, we also present a review in favour of a galactic halo partly built via accretions and mergers of satellite systems. Some of them bear their own globular clusters and therefore ``contaminate'' the system of globular clusters formed ``in situ'', namely within the original potential well of the Galaxy. Therefore, the comparison between our self-enrichment model and the observational data should be limited to the genuine galactic globular clusters, the so-called Old Halo group. [less ▲]

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See detailOld inks: pigments extracted from plants
Despy, Jessica; Wymeersch, Noémie; Bouchat, Isabelle et al

in BOOK OF SHORT ABSTRACTS - POSTER PRESENTATIONS 19TH NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES (2014, February 07)

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A ... [more ▼]

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years) located near Marseilles. Pigments and dyes can be classified into two broad categories and five families: natural pigments and dyes and those called artificial. The first one of these five families includes the mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay, brown clay) and the stones like lapis lazuli (blue). The second and third families gather the organic dyes and pigments. Those that have vegetal origins like indigo (blue) and madder (red) compose the second family and those that have animal origins like cochineal (red) and kermes dyers (carmine) form the third family. One family includes pigments and dyes stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one (family 5). All these pigments, although they have been used for centuries, have been replaced by synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil causes a renewed interest in natural preparations. We report the extraction of pigments from plants. [less ▲]

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See detailOld inks: plant-based inks
Wymeersch, Noémie; Despy, Jessica; Bouchat, Isabelle et al

Poster (2013, November 27)

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A ... [more ▼]

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years) located near Marseilles (France). Pigments and dyes can be classified into two broad categories: natural pigments and dyes and those called artificial. These categories are then subdivided into five families. The first one of these five families includes the mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay, brown clay) and the stones like lapis lazuli (blue) and malachite (green). The second and third families gather the organic dyes and pigments. Those that have vegetal origins like indigo (blue), weld (yellow) and madder (red) compose the family 2 and those that have animal origins like cochineal (red) and kermes dyers (carmine) form the family 3. One family includes pigments and dyes stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one (family 5). All these pigments, although they have been used for centuries, have been replaced by synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil causes a renewed interest in natural preparations. In such purpose, our laboratory in conjunction with the Abbey of Villers-la-Ville has decided to study natural derivatives for inks and focuses in particular on the extraction of pigments from plants. [less ▲]

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See detailOlder adults, physical activity and the internet: Exploring their behaviours, beliefs and opinions
Mouton, Alexandre ULg; Cloes, Marc ULg

in International Journal of Physical Education (2014), 51(1), 18-29

Despite the numerous health benefits, population physical activity (PA) levels are low and decline with age. As the population grows older, with some major implications in terms of public health cost ... [more ▼]

Despite the numerous health benefits, population physical activity (PA) levels are low and decline with age. As the population grows older, with some major implications in terms of public health cost, innovative interventions to promote PA in older adults are of major interest. The Internet holds potential for delivering effective PA interventions and older adults are the largest-growing group of Internet users. Therefore, the main purpose of this study was to explore the older adults’ behaviours, beliefs and opinions about PA and Internet. At baseline, 75 older adults participated in the two stages of the study: (1) an assessment of their behaviours and beliefs about PA and web-based PA promotion; and (2) the experimentation of a single session of home-exercising followed by an interview regarding their opinion on this session. Results exposed that a minority of the participants were regularly active according to the stage of change for PA. Depending on their knowledge of PA, participants mainly perceived social and health aspects as barriers or motivators for their practice of PA. Senior adults considered home-exercising delivered via the Internet sufficiently relevant, acceptable, original, appreciated and reproducible only if it goes along with a reinforced social support and a community-centred PA promotion. [less ▲]

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See detailOLED Light extraction improvement with surface nano-micro texturation based on speckle lithography.
Loicq, Jerôme ULg; Fleury-Frenette, Karl ULg; Viville, Pascal et al

in Physiscs and Optics of OLEDs (2012)

Part of the light rays generated within a luminescent medium with a higher refractive index than that of the exit medium, typically air, undergo total internal reflection phenomenon (TIR); these rays will ... [more ▼]

Part of the light rays generated within a luminescent medium with a higher refractive index than that of the exit medium, typically air, undergo total internal reflection phenomenon (TIR); these rays will be trapped and guided into the emissive material and will not be extracted out of an OLED device for instance. Trapped light is reabsorbed and eventually converted into heat that will be detrimental to the device performance and lifetime. The amount of trapped energy is highly dependent on the values of the refractive indices involved in the multilayer stack constituting the light emitting device. The amount of trapped energy can be extensive and can even reach as much as 75% in certain cases. Solutions to improve the outcoupling efficiency are therefore attractive. In this paper we propose to use laser speckle to produce a random surface with controlled parameters to enhance the OLED outcoupling. A laser speckle pattern is transferred onto a photoresist which will be subsequently converted into a surface relief profile. The optical setup parameters drive the properties of such surface and thus the outcoupling properties. The resulting surface has a quasi-random shape which could be assimilated to a corrugated surface. We will show that these typical surfaces exhibit light extraction enhancement properties. The generated pattern is then transferred onto the exit interfaces of the emitting device. An extraction improvement close to a factor 3 is measured. We finally discuss a practical case for which the laser speckle shape is applied to texture the surface of encapsulating cover glasses in a top-emitting OLED on steel substrates. [less ▲]

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See detailOlefin cyclopropanation and insertion into O-H bonds mediated by copper(I) and palladium(II) covalently anchored to silica xerogels
Sacco, Luigi; Lambert, Stéphanie ULg; Pirard, Jean-Paul ULg et al

in Journal of Catalysis (2005), 232(1), 51-59

Copper(I) and palladium(II) ligated to pyrazolylpyridine hearing a tethered (trimethoxysilyl)propyl group in position 4 of the pyrazole ring were chemically bonded to silica via a sol-gel process. The ... [more ▼]

Copper(I) and palladium(II) ligated to pyrazolylpyridine hearing a tethered (trimethoxysilyl)propyl group in position 4 of the pyrazole ring were chemically bonded to silica via a sol-gel process. The textural properties of the materials (Specific Surface area, porous volume, and pore size distribution) were characterized by nitrogen adsorption-desorption isotherms, mercury porosimetry, and TEM analysis. The hybrid materials were tested as catalysts in olefin cyclopropanation and as potential chemoselective catalysts in the reaction with unsaturated alcohols (double bond versus -OH group), with ethyl diazoacetate as a carbene precursor, and compared with the corresponding homogeneous complexes. © 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailOlefin metathesis as key step in the synthesis of bioactive compounds: Challenges in the total synthesis of (-)-kendomycin
Bicchielli, Dario; Borguet, Yannick ULg; Delaude, Lionel ULg et al

in Current Organic Synthesis (2012), 9(3), 397-405

In this short review article, we highlight the application of the olefin metathesis reaction as a key step in the total synthesis of (-)-kendomycin, a macrocyclic polyketide ansamycin exhibiting ... [more ▼]

In this short review article, we highlight the application of the olefin metathesis reaction as a key step in the total synthesis of (-)-kendomycin, a macrocyclic polyketide ansamycin exhibiting pronounced activity as an endothelin receptor antagonist and antiosteoporotic agent, as well as important antibiotic potency against multiresistant bacteria and remarkable cytotoxicity versus a series of human tumour cell lines. By selecting this example from the recent literature, we hope to illustrate the great synthetic ability of olefin metathesis, while also revealing some problems encountered in the syntheses. © 2012 Bentham Science Publishers. [less ▲]

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See detailOlefin metathesis as key step in the synthesis of bioactive compounds: Challenges in the total synthesis of irioteolides
Demonceau, Albert ULg; Dragutan, I.; Dragutan, V. et al

in Current Organic Synthesis (2012), 9

Iriomoteolides are novel macrolides possessing either a unique 15-membered or a 20-membered macrocycle, and displaying exceedingly potent cytotoxicity with IC50 values of up to 2 ng/mL. Thus far, over a ... [more ▼]

Iriomoteolides are novel macrolides possessing either a unique 15-membered or a 20-membered macrocycle, and displaying exceedingly potent cytotoxicity with IC50 values of up to 2 ng/mL. Thus far, over a period of about four years, ten research groups worldwide have published their synthetic efforts resulting in four total syntheses of iriomoteolides and a few diastereomers thereof, and a number of fragment and macrocyclic core syntheses. Interestingly, three total syntheses involved ring-closing metathesis as the key step for the construction of the macrocycle, whereas the synthesis of three fragments was accomplished using a cross-metathesis reaction. Herein we highlight assets and limitations of the olefin metathesis reaction in the synthesis of the title compounds. [less ▲]

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See detailOlefin metathesis reactions state of the art and outlook
Demonceau, Albert ULg; Delaude, Lionel ULg

in Chimica Oggi = Chemistry Today (2007), 25(5, SEP-OCT), 65-68

Olefin metathesis is a metal-catalysed organic reaction, which involves the statistical redistribution of carbon-carbon double bonds. Since its discovery in the 1950's, this transformation has gained ... [more ▼]

Olefin metathesis is a metal-catalysed organic reaction, which involves the statistical redistribution of carbon-carbon double bonds. Since its discovery in the 1950's, this transformation has gained widespread use in research laboratories and industry for making products ranging, from drugs and polymers to enhanced fuels. Its advantages include the ability to build up complex structural scaffolds with remarkable atom economy. Major industrial processes usually rely on inexpensive, ill-defined, multicomponent catalytic systems, while research laboratory applications take advantage of well-defined metal alkylidene complexes of molybdenum and ruthenium that combine high activities and ease of set-up under reproducible conditions, albeit at the price of a higher cost. [less ▲]

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See detailOlefin metathesis with ruthenium-arene catalysts bearing N-heterocyclic carbene ligands
Delaude, Lionel ULg; Demonceau, Albert ULg

in Dragutan, Valerian; Imamoglu, Yavuz (Eds.) Metathesis Chemistry. From nanostructure design to synthesis of advanced materials (2007)

In this chapter, we summarize the main results of our investigations on the ring-opening metathesis polymn. (ROMP) of cyclooctene catalyzed by various ruthenium (Ru)-arene complexes bearing imidazolin-2 ... [more ▼]

In this chapter, we summarize the main results of our investigations on the ring-opening metathesis polymn. (ROMP) of cyclooctene catalyzed by various ruthenium (Ru)-arene complexes bearing imidazolin-2-ylidene, imidazolidin-2-ylidene, or triazolin-5-ylidene ligands. Three major findings emerged from this study. First, we underscored the intervention of a photochem. activation step due to visible light illumination. Second, we established that the presence of an endocyclic double bond in the carbene ligand central heterocycle was not crucial to achieve high catalytic efficiencies. Third, we demonstrated that ortho-metalation of the N-heterocyclic carbene (NHC) ligand by the Ru center led to inactive catalysts. [less ▲]

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See detailLes oléo-protéagineux dans la CEE : perspectives d'avenir
Burny, Philippe ULg

in Revue de l'Agriculture (1989), 42(2), 741-753

L'agriculture européenne se trouve aujourd'hui dans une phase d'interrogations multiples. Après une période d'expansion extraordinaire, l'heure est à la limitation des productions. Le système des quotas ... [more ▼]

L'agriculture européenne se trouve aujourd'hui dans une phase d'interrogations multiples. Après une période d'expansion extraordinaire, l'heure est à la limitation des productions. Le système des quotas se généralise aux principales productions, sous diverses formes. Contrairement à la situation prévalant il y a quelques années, on dispose, actuellement de trop de terres. Que faut-il en faire ? Une des voies possibles est la culture des oléo-protéagineux, dont la Communauté est fortement déficitaire. Cet article tente de dégager les perspectives d'avenir dans ce secteur important. Pour cela, seront abordés successivement : la situation prévisible, en l'an 2000 et dans un cadre mondial, sur les marchés des huiles et des tourteaux; l'évolution probable dans les divers maillons de la filière (production, transformation, commerce, consommation); la tendance générale de la politique communautaire en ce domaine; les aspects favorables au développement des cultures oléo-protéagineuses dans la Communauté. Si de nombreux éléments entrent en ligne de compte et soulèvent des questions, l'avenir des oléo-protéagineux dépend avant tout de la volonté politique des dirigeants européens et de sa traduction sur le plan financier : ces cultures doivent être rémunératrices pour les producteurs. [less ▲]

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See detailOleuropein or rutin consumption decreases the spontaneous development of OA in Hartley guinea pig
Sanchez, Christelle ULg; Horcajada, Marie-Noëlle; Membrez, Fanny et al

in Arthritis and Rheumatism (2013), 65

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