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See detailSound production in piranhas and relatives: preliminary results
Melotte, Geoffrey ULg; Michel, Christian ULg; Parmentier, Eric ULg

Poster (2014, December 12)

Acoustic communication plays an important role in the life of many teleost species where it is mainly involved in agonistic and/or courtship behaviour(s). Despite the large number of species in the family ... [more ▼]

Acoustic communication plays an important role in the life of many teleost species where it is mainly involved in agonistic and/or courtship behaviour(s). Despite the large number of species in the family Serrasalmidae (92 species), sound production has been described only in some of them, particularly in the genera Serrasalmus and Pygocentrus. The aim of this study is to investigate the sound producing abilities of different Serrasalmidae species and to understand the corresponding mechanisms. Two herbivorous species of Serrasalmidae, Piaractus brachypomus and Metynnis lippincottianus, produce sounds composed of a single pulse. The mechanism involved in these species is not yet understood. In contrast, the calls emitted by several species of Serrasalmus and Pygocentrus are harmonic sounds composed of several pulses without inter-pulse interval. Their mechanism results from the forced vibration of the swimbladder following the contraction of sonic muscles that are attached to tendons surrounding ventrally the bladder. Another species, Pygopristis denticulata, is able to produce two types of sounds. The first sound consists of several pulses with irregular pulse period and is likely produced by a sonic muscle inserting on the skull and on the rostral part of the swimbladder. The second sound is multi-pulsed and, contrary to all other sounds described here, possesses a high dominant frequency suggesting a mechanism that does not involve the swimbladder and that remains to be determined. According to these results, Serrasalmidae seems to contain many species able to produce sounds by means of different mechanisms. [less ▲]

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See detailA morphospace for the marine angelfishes (Pomacanthidae): patterns of diversity
Frederich, Bruno ULg

Poster (2014, December 12)

The Pomacanthidae (marine angelfishes) is an iconic reef fish family of about 88 species. They have a circum-global distribution on tropical to warm-temperate reefs. Marine angelfishes occupy a diverse ... [more ▼]

The Pomacanthidae (marine angelfishes) is an iconic reef fish family of about 88 species. They have a circum-global distribution on tropical to warm-temperate reefs. Marine angelfishes occupy a diverse range of trophic niches, ranging from spongivory and algivory to zooplanktivory. Previous morpho-functional analysis of this family mainly focused on the head region and gut morphology in a limited number of species. However a morphological study including a large sample of angelfish representatives is currently lacking. Here, I explore the diversity of body morphology in this reef fish group. I collected x-ray images of 228 museum specimens from 71 species and I used landmark-based geometric morphometrics to quantify the overall body shape variation within this family. In a test for interspecific allometry, the linear regression of shape variables onto size (LogTL; TL = total length) was significant (P < 0.001). However, the percentage of explained variance in this model (23%) showed no strong relation between size and body shape. Main shape variation across species was explored using a principal component analysis on shape variables. The two main axes (PC1 and PC2) explained 74% of the total variance of the dataset. Pomacanthus spp., which mainly feed on fixed invertebrates (sponges and tunicates), have deep body with high and angular cephalic profile (lowest values along PC1). Conversely, the zooplanktivorous Genicanthus spp., those have a more pelagic lifestyle, show a slender body with shorter anal fin (highest values along PC1). The pigmy angelfishes from the genus Centropyge, which group different diets (omnivory or algivory), show a more robust and rectangular body shape (high scores along PC2). This work provides the row data for future studies dealing with the mode of phenotypic diversification of Pomacanthidae during evolution. [less ▲]

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See detailKracauer : Photographie et Wirklichkeit
Barbion, Sébastien ULg

Scientific conference (2014, December 12)

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See detailDécouverte d'un gène du gigantisme
Beckers, Albert ULg

Scientific conference (2014, December 12)

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See detailFunambulisme, prudence et ruse. Analyse du contexte de travail des directeurs de prison en Belgique
Dubois, Christophe ULg

Scientific conference (2014, December 12)

Cette contribution à l’analyse sociologique du travail des directeurs de prison éclaire tout d’abord le fondement de ce métier : la gestion de la détention. Présentée comme "individualisée ... [more ▼]

Cette contribution à l’analyse sociologique du travail des directeurs de prison éclaire tout d’abord le fondement de ce métier : la gestion de la détention. Présentée comme "individualisée/individualisante" dans les discours politique, la gestion de la détention s'exerce toutefois dans des contextes de travail bureaucratisés (que l'on pense à la gestion du personnel, à la gestion logistique, à la gestion comptable ou à la gestion stratégique), composés de diverses scènes d’interaction (organisationnelle, politique, associative, administrative, judiciaire, interministérielle) et marqués par les « référentiels » (Muller, 2000) de judiciarisation et de managérialisation du secteur public. L’étude du travail des directeurs de prison met ensuite en lumière trois mécanismes de régulation des établissements pénitentiaires : le pouvoir des [chefs] surveillants au centre d’une « régulation autonome » (Reynaud, 1988) ; la multi-dépendance inter-organisationnelle des prisons éprouvée quotidiennement par les directeurs au centre d’une « régulation croisée » (Crozier et Thoenig, 1975) ; l’articulation ponctuelle et « prudente » (Champy, 2012), par les directeurs, des contraintes et des opportunités inhérentes aux différentes scènes sur lesquelles ils interagissent. L'analyse de certaines situations concrètes révèle enfin que le travail des directeurs n’est pas seulement technique (sur les plans juridiques et administratifs) mais aussi politique: il requiert une hiérarchisation des valeurs ou des finalités poursuivies dans leur activité. [less ▲]

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See detailRapid morphological change of barbels (Cyprinidae) after the dry-up of Sahara
Brahimi, Amina; Tarai, Nacer; Libois, Roland ULg

Poster (2014, December 12)

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See detailMise au point d'une forme stable de l'allergène Der p 3 de Dermatophagoides pteronyssinus pour le diagnostic rapide et le développement de nouvelles approches d'immunothérapie de l'allergie aux acariens
Bouaziz, Ahlem ULg

Doctoral thesis (2014)

L’allergie aux acariens touche 20 à 30 % de la population occidentale. L’allergène Der p 3 de l’acarien Dermatophagoides pteronyssinus est une protéase à serine active appartenant à la famille de la ... [more ▼]

L’allergie aux acariens touche 20 à 30 % de la population occidentale. L’allergène Der p 3 de l’acarien Dermatophagoides pteronyssinus est une protéase à serine active appartenant à la famille de la trypsine. Son activité protéolytique pourrait être un facteur adjuvant impliqué dans le développement et la chronicité de l’allergie. A l’heure actuelle, l’implication de Der p 3 dans l’allergie est peu connue et son taux de fixation des IgE provenant de patients allergiques est controversé. Cependant, ces différentes études ont été réalisées au moyen d’un allergène naturel très sujet à l’autolyse et pouvant être contaminé par d’autres protéase. Durant la première partie de cette étude, nous avons pu montrer que rDer p 3 produit en P.Pastoris présente les mêmes propriétés allergéniques que nDer p 3. En effet, les résultats obtenus par test ELISA, inhibition compétitive montrent que rDer p 3 est correctement replié et présente les mêmes épitopes B conformationnels que l’allergène naturel. Dans la deuxième partie de cette thèse, nous avons pu mettre en évidence que l’autolyse de Der p 3 durant le test ELISA a un effet sur la reconnaissance des IgE. En effet, le taux mesuré avec la forme inactive est deux fois supérieur par rapport à la forme active. Der p 3S196A pourrait être donc un meilleur outil de diagnostic pour l’allergie à Der p 3. Dans la troisième partie de cette thèse, nous avons pu montrer que le propeptide de proDer p 3 affecte l’allergénicité de Der p 3. Par une étude in vitro, nous avons prouvé par ELISA, par les tests de dégranulation des basophiles de rat humanisés et d’activation des basophiles humains, que proDer p 3 est moins bien reconnu par les IgE de patients allergiques que la forme mature Der p 3. Ensuite, nous avons montré que les souris sensibilisées par les formes mature et zymogène de l’allergène Der p 3 ont développé une réponse immune de type TH2 et TH1 respectivement. ProDer p 3 pourrait donc être considéré comme une forme hypoallergénique de l’allergène Der p 3. Dans la dernière partie, nous avons construit un modèle tridimensionnel de l’allergène Der p 3 afin de prédire les épitopes B conformationnels par approche bioinformatique. En effet, 3 épitopes B ont été prédits ainsi que les acides aminés impliqués dans la reconnaissance et la fixation des IgE au sein de chaque épitope. Enfin, au moyen de la technique du peptide array, nous avons pu mettre en évidence un épitope B linéaire de l’allergène Der p 3. [less ▲]

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See detailAufmerksamkeit - eine neue Form symbolischen Kapitals (?)
Houscheid, Karin ULg

Scientific conference (2014, December 11)

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See detailProhibitive strategies and prohibitive cycles in Ancient Egyptian
Grossman, Eitan; Polis, Stéphane ULg

Scientific conference (2014, December 11)

In this talk, we present the main prohibitive/negative jussive strategies attested for each state of the language in Ancient Egyptian and we describe the grammaticalization pathways of two prohibitive ... [more ▼]

In this talk, we present the main prohibitive/negative jussive strategies attested for each state of the language in Ancient Egyptian and we describe the grammaticalization pathways of two prohibitive constructions, from Old Egyptian down to Coptic. The paper is structured as follows. In the introduction (§1), a brief review of current typological studies of prohibitives will be given as background information. Then, we start with a description of the two main types of prohibitive constructions that one finds in Coptic, taking into dialectal variety (§2), namely mpr+V(ERB) and mn-V(ERB) “do not V”. Afterwards, we describe the grammaticalization pathway along which the first of these two constructions developed, from Old Egyptian down to Coptic (§3). Additionally, we provide a description of the main prohibitive (as well as negative jussive) strategies that are attested for Earlier (§4) and Later Egyptian (§5), in order to situate more precisely the grammaticalization process of the first strategy within the successive ‘synchronic’ systems of oppositions in the semantic field of prohibition. In a final section (§6), we discuss more in depth the second, more marginal, prohibitive construction of Coptic (mn-V) — investigating Coptic dialectal diversity — and we suggest a diachronic scenario that could account for the appearance and development of this second strategy. [less ▲]

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See detailAssessing spatio-temporal variability and trends in modelled and measured Greenland Ice Sheet albedo (2000–2013)
Alexander, P.; Tedesco, M.; Fettweis, Xavier ULg et al

in Cryosphere (The) (2014), 8

Accurate measurements and simulations of Greenland Ice Sheet (GrIS) surface albedo are essential, given the role of surface albedo in modulating the amount of absorbed solar radiation and meltwater ... [more ▼]

Accurate measurements and simulations of Greenland Ice Sheet (GrIS) surface albedo are essential, given the role of surface albedo in modulating the amount of absorbed solar radiation and meltwater production. In this study, we assess the spatio-temporal variability of GrIS albedo during June, July, and August (JJA) for the period 2000–2013. We use two remote sensing products derived from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS), as well as outputs from the Modèle Atmosphérique Régionale (MAR) regional climate model (RCM) and data from in situ automatic weather stations. Our results point to an overall consistency in spatio-temporal variability between remote sensing and RCM albedo, but reveal a difference in mean albedo of up to ~0.08 between the two remote sensing products north of 70° N. At low elevations, albedo values simulated by the RCM are positively biased with respect to remote sensing products by up to ~0.1 and exhibit low variability compared with observations. We infer that these differences are the result of a positive bias in simulated bare ice albedo. MODIS albedo, RCM outputs, and in situ observations consistently indicate a decrease in albedo of −0.03 to −0.06 per decade over the period 2003–2013 for the GrIS ablation area. Nevertheless, satellite products show a decline in JJA albedo of −0.03 to −0.04 per decade for regions within the accumulation area that is not confirmed by either the model or in situ observations. These findings appear to contradict a previous study that found an agreement between in situ and MODIS trends for individual months. The results indicate a need for further evaluation of high elevation albedo trends, a reconciliation of MODIS mean albedo at high latitudes, and the importance of accurately simulating bare ice albedo in RCMs. [less ▲]

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See detailPsychopathie, adaptation et traitement du stimulus émotionnel
Grandjean, Sylvie; Englebert, Jérôme ULg

Scientific conference (2014, December 11)

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See detailLaïcité à la française : de la prétention universaliste à l'obsession identitaire
Jacquemain, Marc ULg

Conference (2014, December 11)

Le mot "laïcité" est revendiqué par des groupes d'extrême-droite ouvertement racistes et conspirationnistes comme "Riposte laïque". L'article montre que le même imaginaire conspirationniste, sous la même ... [more ▼]

Le mot "laïcité" est revendiqué par des groupes d'extrême-droite ouvertement racistes et conspirationnistes comme "Riposte laïque". L'article montre que le même imaginaire conspirationniste, sous la même structure narrative peut être retrouvé sous des formes débarrassée de leur racisme explicite dans des textes considérés comme "mainstream" au sein de la laïcité, en analysant un texte du Rappel. A partir de là, on tente de montrer que cette "dérivation conspirationniste" peut trouver des prises dans des formulations "progressistes" de la laîcité dès lors que ces formulations partent pour point de départ le point de vue à la fois holiste et idéaliste d'un "laos" toujours-dejà-là, comme chez Peña ruiz [less ▲]

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See detailCystic Fibrosis screening by simultaneous ELISA for IRT1 and PAP proteins. A pilot study.
BOEMER, François ULg

Scientific conference (2014, December 11)

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See detailRGD surface functionalization of the hydrophilic acrylic intraocular lens material to control posterior capsular opacification
Huang, Yi-Shiang ULg; Bertrand, Virginie ULg; Bozukova, Dimitriya et al

in PLoS ONE (2014), 9(12), 32

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal ... [more ▼]

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient’s age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development. [less ▲]

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