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See detailGlobal regression model for moisture content determination using near-infrared spectroscopy
Clavaud, Matthieu ULg; Roggo, Yves; Degardin, Klara et al

in European Journal of Pharmaceutics and Biopharmaceutics (2017)

Near-infrared (NIR) global quantitative models were evaluated for the moisture content (MC) determination of three different freeze-dried drug products. The quantitative models were based on 3822 spectra ... [more ▼]

Near-infrared (NIR) global quantitative models were evaluated for the moisture content (MC) determination of three different freeze-dried drug products. The quantitative models were based on 3822 spectra measured on two identical spectrometers to include variability. The MC, measured with the reference Karl Fischer (KF) method, were ranged from 0.05% to 4.96%. Linear and non-linear regression models using Partial Least Square (PLS), Decision Tree (DT), Bayesian Ridge Regression (Bayes-RR), K-Nearest Neighbors (KNN), and Support Vector Regression (SVR) algorithms were created and evaluated. Among them, the SVR model was retained for a global application. The Standard Error of Calibration (SEC) and the Standard Error of Prediction (SEP) were respectively 0.12% and 0.15%. This model was then evaluated in terms of total error and risk-based assessment, linearity, and accuracy. It was observed that MC can be fastly and simultaneously determined in freeze-dried pharmaceutical products thanks to a global NIR model created with different medicines. This innovative approach allows to speed up the validation time and the in-lab release analyses. [less ▲]

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See detailEffects of an experimental resource pulse on the macrofaunal assemblage inhabiting seagrass macrophytodetritus
Remy, François ULg; Gobert, Sylvie ULg; Lepoint, Gilles ULg

in Belgian Journal of Zoology (2017), 147(1), 1-15

Physical disturbances and resource pulses are major structuring drivers of terrestrial and aquatic ecosystems. The accumulations of exported dead leaves from the Neptune grass, Posidonia oceanica (L ... [more ▼]

Physical disturbances and resource pulses are major structuring drivers of terrestrial and aquatic ecosystems. The accumulations of exported dead leaves from the Neptune grass, Posidonia oceanica (L.) Delile are ephemeral and highly dynamic detrital habitats offering food sources and shelter for vagile macrofauna community. These habitats are frequently subject to wind and storms which can add “new” detrital material to previous accumulations; these can be defined as resource pulses and could potentially impact the associated macrofauna. This study assesses the impact of an experimental resource pulse on the macrofauna associated with exported P. oceanica litter accumulations. The experimental design consisted of two pulse treatments (the addition of dead leaves with and without the associated fauna), and two controls (one procedural, and one total control), where the added material was left underwater for 14 days. Invertebrates then present in the sampled detritus were all identified and counted. Our data suggest that the responses of these invertebrates to resource pulses present intermediate characteristics between aquatic and terrestrial ecosystems responses. Inputting a moderate amount of dead P. oceanica leaves into experimental mesocosms had a non-negligible impact and rapidly affected the macrofauna community. Specialist detritivores species were boosted while herbivore/detritivore species dramatically decreased. Predators also showed a modest but significant density increase, demonstrating the fast propagation of the pulse response throughout the entire community and through several trophic levels. Strict hypoxia-tolerant species were also only observed in the treated mesocosms, indicating the strong influence of resource pulses on physico-chemical conditions occurring inside litter accumulations. [less ▲]

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See detailCosmological Time, Entropy and Infinity
Hauret, Clémentine ULg; Magain, Pierre ULg; Biernaux, Judith ULg

in Entropy (2017), 19(7),

Time is a parameter playing a central role in our most fundamental modelling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative ... [more ▼]

Time is a parameter playing a central role in our most fundamental modelling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motion and on the strength of the gravitational field in which they are embedded. In standard cosmology, the time parameter is the one measured by fundamental clocks (i.e., clocks at rest with respect to the expanding space). This proper time is assumed to flow at a constant rate throughout the whole history of the universe. We make the alternative hypothesis that the rate at which the cosmological time flows depends on the dynamical state of the universe. In thermodynamics, the arrow of time is strongly related to the second law, which states that the entropy of an isolated system will always increase with time or, at best, stay constant. Hence, we assume that the time measured by fundamental clocks is proportional to the entropy of the region of the universe that is causally connected to them. Under that simple assumption, we find it possible to build toy cosmological models that present an acceleration of their expansion without any need for dark energy while being spatially closed and finite, avoiding the need to deal with infinite values. [less ▲]

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See detailUndoing Art
Delville, Michel ULg

Conference (2017, July 13)

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See detailHighly efficient doped nanocristalline TiO2 for water Treatment
Mahy, Julien ULg; Léonard, Géraldine ULg; Zubiaur, Anthony ULg et al

Conference (2017, July 13)

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See detailDu dessin au design. Seth comme auteur-rééditeur
Crucifix, Benoît ULg

Conference (2017, July 13)

Depuis ces dernières années, l’édition de bande dessinée connaît un véritable boom de rééditions patrimoniales. Dans le contexte nord-américain, ce sont justement les auteurs associés au « roman ... [more ▼]

Depuis ces dernières années, l’édition de bande dessinée connaît un véritable boom de rééditions patrimoniales. Dans le contexte nord-américain, ce sont justement les auteurs associés au « roman graphique » – ceux-là même qui ont exploré le livre en tant qu’objet en réalisant eux-mêmes le design de leurs œuvres – qui sont aussi invités à prendre en charge la conception graphique de ces rééditions d’œuvres du passé qu’ils aident à faire (re)découvrir. Cette communication a pour but d’étudier les designs réalisés par l’auteur canadien Seth pour plusieurs œuvres complètes : The Complete Peanuts, The John Stanley Library et The Collected Doug Wright. Les designs de Seth se caractérisent par leur mise-en-avant d’une esthétique idiosyncratique, comme il l’a lui-même exprimé : « when I design something it really is too much about me » (Spurgeon, 143). Elles se lient donc intimement à la production « propre » de l’auteur. Dans le cas de Stanley et Doug Wright, ces rééditions sont d’ailleurs liées à des essais écrits par Seth, relevant d’un travail autant esthétique qu’historiographique. Il s’agira d’abord de comprendre la spécificité culturelle de cette pratique de réédition dans l’édition « alternative » américaine, qui diffère du contexte éditorial européen ; plus en avant, le cas de Seth permettra de comprendre comment cette pratique ressort d’un mécanisme de canonisation particulier (Heer), mais aussi de montrer à quel point ce type d’objets met en avant une « fonction-auteur » (Foucault) inextricablement liée à une activité historiographique, éditoriale et patrimoniale. [less ▲]

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See detailPanel “Quand la bande dessinée se reproduit : imitation, reprise et rétro-réflexivité”
Crucifix, Benoît ULg; Busi-Rizzi, Giorgio

Diverse speeche and writing (2017)

Co-organisation et présidence du panel "Quand la bande dessinée se reproduit : imitation, reprise et rétro-réflexivité" – Dans une industrie culturelle basée sur les principes de série et d’imitation, les ... [more ▼]

Co-organisation et présidence du panel "Quand la bande dessinée se reproduit : imitation, reprise et rétro-réflexivité" – Dans une industrie culturelle basée sur les principes de série et d’imitation, les questions de reproduction occupent une place toute particulière, illustrée par ce terme spécifique de swipe utilisé dans l’industrie du comic book. L’imitation s’est instituée comme principe éditorial autant dans la bande dessinée nord-américaine que dans la bande dessinée franco-belge : le style graphique se constitue ainsi souvent par imitation et reproduction, comme le montre l’exemple de l’émulation des styles ‘singuliers’ d’artistes tels que Jack Kirby ou André Franquin. Les rééditions des œuvres du passé tout comme les reprises de série classique s’épanouissent aujourd’hui et, simultanément, la bande dessinée s’empare de plus en plus de son propre passé, invoquant les connaissances encyclopédiques de ses lecteurs et s’engageant dans une forme de « rétro-réflexivité » (Brett Camper). Ces pratiques de reproduction par imitation indiquent différentes manières de penser la mise-à-disposition du passé dans le présent. Elles négocient ainsi de façon spécifique et historique le rapport à la reproductibilité en bande dessinée, par le biais de diverses techniques (recopiage, décalquage, collage, dessin, détournement, réinterprétation graphique, photocopie, clins d’œil, copier/coller, etc.) : à chaque fois, elles semblent alors interroger le rapport entre dessin et reproduction, que celle-ci soit manuelle, mécanique ou numérique. Cette session portera sur la prégnance de la reproduction par imitation dans la bande dessinée afin d’en examiner les enjeux culturels et esthétiques qui la lient à son passé et à son histoire. Comment la bande dessinée se reproduit-elle elle-même ? Quelles sont les pratiques de citation qui lui sont propres ? Comment ce rapport au passé a-t-il changé ? [less ▲]

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See detailPrésidence de la session "Réappropriations: recyclages, effacements, détournements"
Delville, Michel ULg

Diverse speeche and writing (2017)

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See detailEffect of surface modification of polylactides on fibroblasts L-929 and osteoblasts MG-63
Tilkin, Rémi ULg; Regibeau, Nicolas ULg; Lambert, Stéphanie ULg et al

Conference (2017, July 12)

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently ... [more ▼]

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently based on the realization of temporary porous matrices, also called "scaffolds", design as model and structure for the development of cells. Surface properties of those biomaterials are some determinant criteria for cell adhesion and proliferation. The scope of this work is the study of adhesion and proliferation of fibroblasts L-929 and osteoblasts MG-63 on untreated, hydrolyzed or aminolyzed polylactides. First, these substrates are developed: poly-L,D-lactide (PDLLA) powder is pressed into disks. The surface of disks was chemically modified by hydrolysis and aminolysis surface treatments. Surface modifications were based on previous studies. [1,2] The hydrolysis process is carried out by immersing PDLLA disks in 2 M NaOH for 20 min at room temperature (24°C) under constant agitation. The aminolysis process is performed by placing PDLLA disks in 15 % ethylenediamine in isopropanol for 5 min at room temperature (24°C) under constant agitation. Substrates are characterized by optical microscopy, Scanning Electron Microscopy and water contact angle. Finally, cell adhesion, proliferation, and viability on these substrates are assessed by cell counting and MTT assay after 1, 4, and 8 days of cell culture. Results from surface characterization show an increase of roughness for hydrolyzed polylactide. Regarding water contact angle measurements, values are smaller on treated substrates even though the difference with untreated substrates appears smaller than expected in the literature. [1,2] Cell counting and MTT assay show an increase of cell proliferation and cell viability for treated polylactide substrates in the case of fibroblasts and a decrease of cell proliferation for aminolyzed polylactide substrates in the case of osteoblasts. In conclusions, this work highlights the different effects of surface modification on fibroblasts and osteoblasts viability. References : [1]. Wang YQ, Cai JY. Enhanced cell affinity of poly(L-lactic acid) modified by base hydrolysis: wettability and surface roughness at nanometer scale. Current Applied Physics 2007, 7(S1):e108–e111. [2]. Lin Y, Chrzanowski W, Knowles J, Bishop A, Bismarck A. Functionalized poly(D,L-lactide) for pulmonary epithelial cell culture. Advanced Engineering Materials 2010, 12(4): B101–B112. [less ▲]

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See detailAdvanced oxidative treatment for waste water contaminated by pharmaceutical products
Wolfs, Cédric ULg; Vreuls, Christelle; Gillard, Nathalie et al

Conference (2017, July 12)

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with pharmaceutical products. The aim is to validate a physico-chemical ... [more ▼]

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with pharmaceutical products. The aim is to validate a physico-chemical process that has to be placed downstream a classical biological treatment in existing waste water treatment plants (domestic, industrial or hospital). [less ▲]

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See detailRhétorique du détournement vidéoludique. Le cas de Pokémon
Barnabé, Fanny ULg

Doctoral thesis (2017)

La présente recherche se situe au croisement de plusieurs traditions disciplinaires – les sciences du jeu, les études littéraires, la rhétorique, les cultural studies – et de plusieurs objets – le jeu, le ... [more ▼]

La présente recherche se situe au croisement de plusieurs traditions disciplinaires – les sciences du jeu, les études littéraires, la rhétorique, les cultural studies – et de plusieurs objets – le jeu, le détournement, les fanfictions, machinimas, speedruns, let’s plays et mods. Sans prétendre opérer ici leur synthèse ou leur conciliation, nous tenterons de dégager, entre ces différents domaines, de nouvelles ouvertures : nous montrerons, en circulant parmi eux, qu’ils sont pris dans des tensions, des dynamiques, des questionnements similaires et, surtout, centraux pour la compréhension de la culture populaire contemporaine. Plusieurs objectifs nous animent : définir le détournement et, à travers lui, éclairer sous un autre jour le fonctionnement du jeu ; développer un métadiscours à même de soutenir l’analyse des œuvres produites par les joueurs ; enfin, par la même occasion, défendre l’intérêt d’étudier de près ces œuvres amateurs, trop souvent délaissées par la recherche au profit des pratiques, et qui sont pourtant des épicentres essentiels autour desquels se développent les cultures ludiques. La poursuite de ces objectifs, toutefois, ne va pas sans soulever des questions complexes, qui traversent toute la thèse : quels parallèles et quelle frontière établir entre le détournement et le jeu ? Comment une œuvre est-elle reconnue, étiquetée, classée comme un détournement ? Qu’est-ce au juste qu’une œuvre dans un domaine où l’intertextualité, la reprise, la réinterprétation sont des normes ? Avec quels outils décrire les formes du détournement, et qu’ont en commun les genres disparates regroupés sous cette dénomination ? Nous traiterons ces diverses interrogations en deux temps. La première partie de la thèse, qui comporte deux sous-sections, en constituera le socle théorique : un premier chapitre y aborde les relations intimes entre jeu et détournement, tout en resituant notre recherche dans les différents champs qu’elle fait se croiser ; le second chapitre s’attache à la constitution d’un cadre métadiscursif inspiré de la rhétorique, visant à définir ce que pourraient être des « figures » du détournement vidéoludique. La deuxième partie, plus analytique, servira d’application au cadre précédemment construit, en montrant son utilité sur des études d’œuvres concrètes. Celles-ci sont réparties en trois grandes catégories : les détournements par le play (let’s plays, speedruns, tool-assisted speedruns et machinimas), les détournements du game (fanfictions et mods) et les recontextualisations (« Twitch plays… »). Par ailleurs, en guise de fil conducteur, toutes ces œuvres – de formes et de genres variés – auront pour point commun essentiel d’être dérivées d’un même univers fictionnel : celui de la licence Pokémon. [less ▲]

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See detailGestion intégrée et systémique du risque tempête au sein de la filière forêt-bois
Riguelle, Simon ULg

Scientific conference (2017, July 11)

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See detailDetermining fine population structure using iterative pruning
Chaichoompu, Kridsadakorn ULg; Yazew, Fentaw Abegaz; Tongsima, Sissades et al

Poster (2017, July 10)

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an ... [more ▼]

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an unsupervised clustering algorithm called the iterative pruning method to capture population structure (IPCAPS). Our method supports ordinal data which can be applied directly to SNP data to identify fine-level population structure and it is built on the iterative pruning Principal Component Analysis (ipPCA) algorithm (Intarapanich et al. 2009). The IPCAPS involves an iterative process using multiple splits based on multivariate Gaussian mixture modeling of principal components and Clustering EM estimation as in Lebret et al. (2015). In each iteration, rough clusters and outliers are also identified using our own method called RubikClust. The fixation index (FST) is known to measure a distance between populations and FST = 0.001 may be said to be genetically distinct among the European populations (Tian et al. 2008, Huckins et al. 2014). To observe fine-level population structure using FST, we examined simulated scenarios of one population, 500-8,000 individuals, 5,000-10,000 independent SNPs in HWE (Balding and Nichols 1995), with 100 replicates for each scenario. The simulated SNPs were encoded as additive coding and there was no missing genotype generated. We introduced negative control by subjecting individuals to be separated into two groups using kmeans. We observed that FST values of divided groups were lower than 0.0008, which can be defined as the minimum FST to detect fine-level population structure. To evaluate the performance of our method, we tested different simulated data sets of 2-3 populations, 250 individuals per population, 10,000 independent SNPs in HWE, and FST=[0.0008,0.005], with 100 replicates for each data set. For real-life data sets, we applied the IPCAPS to Thai (Wangkumhang et al. 2013) and HapMap populations. Our method showed that a population classification accuracy was superior to the ipPCA in simulated scenarios of extremely subtle structure (FST=[0.0009,0.005]). In case of the Thai population, results to detect fine-level structure were obtained as well as in case of the HapMap populations. We are convinced that the IPCAPS has a potential to detect fine-level structure and it will be important in molecular reclassification studies of patients once underlying population structure has been removed. [less ▲]

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See detailIncreased sea ice cover disrupts food web structure in Antarctic coastal benthic ecosystem
Michel, Loïc ULg; Danis, Bruno; Dubois, Philippe et al

Conference (2017, July 10)

Antarctica currently undergoes strong and contrasted impacts linked to climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice ... [more ▼]

Antarctica currently undergoes strong and contrasted impacts linked to climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, the sea ice cover of East Antarctica unexpectedly tends to increase. Here, we studied shallow (0-20 m) benthic food web structure on the coasts of Petrels Island (Adélie Land, East Antarctica) during an event of unusually high spatial and temporal (two successive austral summers without seasonal break-up) sea ice cover. Using time-tested integrative trophic markers (stable isotope ratios of carbon, nitrogen and sulfur) and state-of-the-art data analysis tools (Bayesian ecological models), we studied the structure of the food web associated to benthic macroinvertebrates communities. In total, 28 taxa spanning most present animal groups (sponges, sea anemones, nemerteans, nematods, sipunculids, sessile and mobile polychaetes, gastropods, bivalves, pycnogonids, crustaceans, sea stars, sea urchins, brittle stars and sea cucumbers) and functional guilds (grazers, deposit feeders, filter feeders, predators, scavengers) were investigated. Our results indicate that the absence of seasonal sea ice breakup deeply influences coastal benthic food webs. We recorded marked differences from literature data, both in terms of horizontal (i.e. primary producers and resources supporting animal populations) and vertical (i.e. trophic level of the studied consumers) structure of the food web. Overall, sympagic algae dominated the diet of many key consumers, and the trophic levels of invertebrates were low, suggesting omnivore consumers relied less on predation and/or scavenging than in normal environmental conditions. Surprisingly, few animals seemed to feed on the extremely abundant benthic biofilm, whose exceptional development was also presumably linked with the peculiar sea ice conditions. Comparison of data obtained in the austral summers of 2013-2014 (first year without seasonal breakup) and 2014-2015 (second year without seasonal breakup) clearly showed that the observed trends were linked to actual temporal changes in invertebrate feeding habits rather than with other potential ecological drivers. Our results provide insights about how Antarctic benthic consumers, which have evolved in an extremely stable environment, might adapt their feeding habits in response to sudden changes in environmental conditions and trophic resource availability. They also show that local and/or global trends of sea ice increase in Antarctica have the potential to cause drastic changes in food web structure and therefore impact benthic communities. This research was funded by the Belgian Federal Science Policy Office (BELSPO) in the framework of the vERSO project (http://www.versoproject.be). [less ▲]

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See detailThermal treatments for tailoring the microstructure and wear behaviour of friction stir processed Aluminium-C fibres composites
Mertens, Anne ULg; Storti, Marco; Simar, Aude et al

Conference (2017, July 10)

A new and simple method for the production of metal matrix composite by friction stir processing (FSP) sandwiches made from metal sheets (e.g. Mg- or Al-based alloy) intercalated with a reinforcing ... [more ▼]

A new and simple method for the production of metal matrix composite by friction stir processing (FSP) sandwiches made from metal sheets (e.g. Mg- or Al-based alloy) intercalated with a reinforcing material e.g. a carbon fabric has recently been devised by the present authors [A. Mertens et al., Mater. Charact. 107 (2015), 125-133]. This process allowed the production of large-size sound metal matrix composites, but the usage properties (e.g. wear resistance,...) of these composites are not yet optimised. Indeed, the matrix of the composite may be softened after processing as FSP is known to cause dissolution of the precipitates responsible for strengthening Mg- or Al-based alloys [A. Simar et al., Mater. Sci. Eng. A 486 (2008), 85-95]. This work thus aims at investigating the potential of thermal treatments for tailoring the microstructure and wear behaviour of age hardenable aluminium alloy 6005 – C fibres composites. The effect of (solution and) ageing treatments on the microstructure and hardness of FSPed Al-C composites has been investigated using optical and scanning electron microscopy, along with Vickers hardness tests. The wear behaviour of the as-FSPed and of the heat treated specimens has been characterized using a pin-on-disc tribometer. Moreover, reference AA6005 samples without C fibres have been produced and tested under similar conditions. The comparison of the reference and of the composite samples allows a better understanding of the role of the C fibres in controlling the grain size of the Al matrix by influencing recrystallisation during FSP and grain growth during thermal treatments. [less ▲]

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