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Peer Reviewed
See detailNo evidence for genetic differentiation between French and Belgian populations of the exotic tree Robinia pseudoacacia
Bouteiller, Xavier; Aikio, E; Raimbault, A et al

Poster (2016, May)

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Peer Reviewed
See detailStructuration of Robinia pseudoacacia L. genetic diversity in the American natural range and derived Belgian populations
Verdu, Cindy; Daïnou, Kasso; De Thier, Olivier et al

Poster (2016, May)

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See detailConvention relative à la réhabilitation du Saumon atlantique dans le bassin de la Meuse (Rapport 2015-2016)
Ovidio, Michaël ULg; Dierckx, Arnaud ULg; Benitez, Jean-Philippe ULg et al

Report (2016)

Le présent rapport d’activités intègre les travaux des deux équipes universitaires de Liège et de Namur (coordination Ulg – Dr M. Ovidio) dans la cadre de la subvention relative à la réhabilitation du ... [more ▼]

Le présent rapport d’activités intègre les travaux des deux équipes universitaires de Liège et de Namur (coordination Ulg – Dr M. Ovidio) dans la cadre de la subvention relative à la réhabilitation du saumon atlantique dans le bassin de la Meuse. [less ▲]

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See detailDerivation of cochlear cells from pathological or isogenic human iPSCs for modeling hereditary hearing loss
Czajkowski, Amandine ULg; Grobarczyk, Benjamin; Hanon, Kevin ULg et al

Poster (2016, May)

Alström Syndrome (AS) is a human autosomal recessive genetic disorder characterized by numerous clinical symptoms including deafness. AS is caused by mutations in the ALMS1 gene encoding for ALMS1 protein ... [more ▼]

Alström Syndrome (AS) is a human autosomal recessive genetic disorder characterized by numerous clinical symptoms including deafness. AS is caused by mutations in the ALMS1 gene encoding for ALMS1 protein expressed at the basal body and implicated in ciliogenesis, cell cycle and proliferation (Jagger et al., 2011; Zulato et al., 2011 & Shenje et al., 2014). We are interesting in understanding the unknown mechanisms involving this protein in the genetic deafness of AS patients. To develop a model as closer as possible to the human pathology, we are using human induced pluripotent stem cells (hiPSCs) generated from fibroblasts of healthy and AS patients. Using a stepwise protocol, we demonstrated that healthy hiPSCs (waiting for isogenic hiPSCs) can generate a population of cells with gene and protein expression patterns consistent with the ones of otic progenitor cells (OSCs). At this differentiation stage, we observed some proliferation and apoptotic defects between healthy and AS cells. When human OSCs are co-cultured with mouse feeder cells, they are able to differentiate into hair cells (HCs). We successfully differentiated AS hiPSCs generated from AS patients into HCs. We are currently confirming gene expression pattern and testing HCs functionality.  To exclude patient linked epigenetics and differentiation defects, we are correcting the genomic mutation in the AS hiPSCs to generate isogenic hiPSCs using the CRIPSR/Cas9 system. Thanks to the isogenic hiPSCs we will be able to confirm that these defects are well due to the ALMS1 mutation. [less ▲]

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See detailMixed Component Oleogels Prepared Using Synergistic Combinations of Monoglyceride and Phytosterols
Sintang, Mohd Dona Bin; Rimaux, Tom; Danthine, Sabine ULg et al

Conference (2016, May)

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See detailCoherent backscattering in the Fock space of Bose- and Fermi-Hubbard systems
Engl, Thomas; Dujardin, Julien; Tisserond, Emilie et al

Poster (2016, May)

Coherent backscattering generally refers to a significant and robust enhancement of the average backscattering probability of a wave within a disordered medium, which from a semiclassical point of view ... [more ▼]

Coherent backscattering generally refers to a significant and robust enhancement of the average backscattering probability of a wave within a disordered medium, which from a semiclassical point of view arises due to the constructive interference between backscattered trajectories and their time-reversed counterparts. We recently investigated the manifestation of this wave interference phenomenon in the Fock space of a disordered Bose-Hubbard system of finite extent [1], which can potentially be realized using ultracold bosonic atoms within optical lattices. Preparing the atoms in a well-defined Fock state of the lattice and letting the system evolve for a finite time will, for suitable parameters of the system and upon some disorder average over random on-site energies of the lattice, generally give rise to an equidistribution of the occupation probability within the energy shell of the Fock space that corresponds to the initial energy of the system, in accordance with the quantum microcanonical ensemble. We find, however, that the initial state is twice as often encountered as other Fock states with comparable total energy, which is a consequence of coherent backscattering [1]. Most recently, we showed that this phenomenon also arises in spin 1/2 Fermi-Hubbard rings that involve Rashba hopping terms (which combine inter-site hoppings with spin flips and arise from spin-orbit coupling), for which a newly developed semiclassical theory [2] correctly predicts a coherent enhancement of the occupation probabilities of the initial state and its spin-flipped counterpart. Moreover, performing a global spin flip within this Fermi-Hubbard system will give rise to significant spin echo peaks on those two Fock states, which is again a consequence of quantum many-body interference [3]. The semiclassical predictions of these enhancements and peaks are found to be in very good agreement with numerical findings obtained from the exact quantum time evolution within this Fermi-Hubbard system. References [1] T. Engl, J. Dujardin, A. Argüelles, P. Schlagheck, K. Richter, and J. D. Urbina, Phys. Rev. Lett. 112, 140403 (2014). [2] T. Engl, P. Plößl, J. D. Urbina, and K. Richter, Theoretical Chemistry Accounts 133, 1563 (2014). [3] T. Engl, J. D. Urbina, and K. Richter, arXiv:1409.5684. [less ▲]

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See detailLa scrittura che pensa: saggismo, letteratura, vita
Curreri, Luciano ULg; Cadoni, Alessandro; Dalmas, Davide et al

Book published by Nerosubianco (2016)

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Peer Reviewed
See detailDESIGN AND MODELIZATION OF ACONVEX GRATING FOR AN HYPERSPECTRAL IMAGER OF THE CHANDRAYAAN 2 INSTRUMENT FOR THE MOON PROBE IN THE INFRARED
Sabushimike, Bernard ULg; Horugavye, Georges ULg; Piron, Pierre ULg et al

in International Journal of Latest Research in Science and Technology (2016), 5(2), 69-74

For hyperspectral imaging, diffraction gratings based spectrometers exhibit high spectral resolution and optical performance. Among those spectrometers, the Offner type (which consists of an entrance slit ... [more ▼]

For hyperspectral imaging, diffraction gratings based spectrometers exhibit high spectral resolution and optical performance. Among those spectrometers, the Offner type (which consists of an entrance slit, two concave mirrors and convex grating) offers a lot of advantages. In this paper, we propose the design and modelization of a convex grating which covers a spectral band ranging from 0.7 μm to 5 μm with a minimum diffraction efficiency of 20% at 800 nm, 50% at 3000 nm and 25% at 5000 nm. For a so wide band, a grating with a single blaze cannot satisfy these requirements. We will therefore propose an approach of multi-blaze grating which is subdivided into different sections each with its own blaze angle. Meanwhile, we perform the diffraction efficiency prediction using the scalar and rigorous theories to prove the compliance of this design with the technical specifications. The rigorous theory will also allow us to study the polarization sensitivity of this grating and the calculation of the diffraction efficiency of a grating with a profile degraded by manufacturing errors to assess the impact on the diffraction efficiency and the sensitivity to polarization [less ▲]

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See detailCharles de Gaulle et les Belges francophones, 1940-1950 : la construction d’un mythe
Lanneau, Catherine ULg; Balace, Francis ULg

Conference given outside the academic context (2016)

Detailed reference viewed: 15 (1 ULg)
See detailTable ronde : Lecture/jeux vidéo, quelles expériences ?
Barnabé, Fanny ULg

Conference given outside the academic context (2016)

Le jeu vidéo et le texte sont de vieux compagnons de route. Des premiers jeux vidéo textuels à Skyrim, leur relation est pourtant compliquée. La Compagnie Rebonds d’histoires vous propose au cours de ... [more ▼]

Le jeu vidéo et le texte sont de vieux compagnons de route. Des premiers jeux vidéo textuels à Skyrim, leur relation est pourtant compliquée. La Compagnie Rebonds d’histoires vous propose au cours de cette table ronde de changer de point de vue : plutôt que de considérer les œuvres, intéressons-nous à l’expérience vécue par le lecteur et le joueur. Qu’en est-il des notions d’interactivité , de liberté, d’activité ? Quels liens entre lecteur/joueur, oeuvre et auteur ? Avec la participation de Léo HENRY (ed la Volte, Gallimard, Dystopia…) et de Fanny BARNABÉ (chercheuse en sociologie de la littérature). [less ▲]

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See detailGiser: Gestion intégrée sol-érosion-ruissellement - Rapport d'activités 2015-2016
Bielders, Charles; Degré, Aurore ULg; Demarcin, Pierre ULg et al

Report (2016)

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See detailOn Vulnerability and Vulnerabilities of Incident Reporting
Rossignol, Nicolas ULg

Doctoral thesis (2016)

This PhD thesis – composed of a series of five papers tied together by an introduction and conclusions – explores the functioning of an Incident Reporting System used in a high-risk organization. It aims ... [more ▼]

This PhD thesis – composed of a series of five papers tied together by an introduction and conclusions – explores the functioning of an Incident Reporting System used in a high-risk organization. It aims at understanding how safety is actually constructed by and through this reporting system and what it actually does to the meaning of safety when it prescribes a set of sociotechnical practices. From a conceptual point of view, this PhD thesis departs from classical risk or vulnerability analyses which tend to measure factors in order to produce what are supposed to be “objective” results and “manageable” recommendations for decision makers. By relying on a constructivist understanding of vulnerability, this research explores and characterizes situations and events the consequences of which are ambiguous and the probabilities of which are uncertain. It thus broadens the scope of classical risk or vulnerability analyses and complements it with a qualitative and discourse-based attention to organizational, cultural and ethical questions. [less ▲]

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See detailQuel projet pour l'accueil de toutes les familles ?
Pirard, Florence ULg

Conference given outside the academic context (2016)

Notre intervention interroge les enjeux d'accessibilité primaire et secondaire des lieux d'accueil de la petite enfance où sont potentiellement assurées trois fonctions qui peuvent entrer en tension : les ... [more ▼]

Notre intervention interroge les enjeux d'accessibilité primaire et secondaire des lieux d'accueil de la petite enfance où sont potentiellement assurées trois fonctions qui peuvent entrer en tension : les fonctions économique, sociale et éducative. Elle souligne l'importance de dispositifs de Recherche Action Formation qui soutiennent la réflexion et l'évaluation régulatrice des professionnel-le-s, mais aussi des parents sur les actions à mettre en oeuvre au bénéfice de tous dans une dynamique locale concertée avec l'ensemble des acteurs. [less ▲]

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See detail"Passer de voix en voix". Traduire le rythme selon Meschonnic
Viehöver, Vera ULg

Scientific conference (2016, April 29)

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See detailPhysical activity: an unknown concept
Cloes, Marc ULg

Conference (2016, April 29)

Physical educators do not have necesseraly good representations about physical activity and sedentariness. During the presentation, participants will be involved in an interactive process aiming to ... [more ▼]

Physical educators do not have necesseraly good representations about physical activity and sedentariness. During the presentation, participants will be involved in an interactive process aiming to underline the main concepts that they should use in order to become effective agents of physical activity promotion. [less ▲]

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See detailUse of stable isotope ratios to delineate coastal benthic food web structure in Adélie Land (East Antarctica)
Michel, Loïc ULg; Dubois, Philippe; Eleaume, Marc et al

Poster (2016, April 29)

Antarctica currently undergoes strong and contrasted impacts linked with 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 with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, in some parts of East Antarctica sea ice cover tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic production and/or modifications of benthic community structure (i.e. resource availability for benthic consumers). 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 stable isotope ratios of C, N and S, we examined importance of several organic matter sources (benthic macroalgae, benthic biofilm, sympagic algae, suspended particulate organic matter and penguin guano) for nutrition of over 20 taxa of benthic invertebrates (sponges, sea anemones, nemerteans, sessile and mobile polychaetes, gastropods, bivalves, sipunculids, pycnogonids, amphipods, sea stars, sea urchins and sea cucumbers) spanning most present functional guilds. 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. [less ▲]

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See detailThe CCAMBIO project to characterize the biodiversity and distribution of microorganisms in microbial mats of Antarctic lakes
Durieu, Benoit ULg; Lara, Yannick ULg; Obbels, Dagmar et al

Poster (2016, April 29)

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms in lacustrine microbial mats using a combination of techniques including microscopical observations (light and ... [more ▼]

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms in lacustrine microbial mats using a combination of techniques including microscopical observations (light and electronic microscopy), strain isolation, and molecular diversity assessment using Next Generation Sequencing. The samples were collected in different Antarctic and sub-Antarctic biogeographical regions. A detailed microscopic study of the Antarctic diatom diversity allowed to revise a number of taxa and discover new ones. A multivariate analysis of diatoms showed that these regions hosted different diatom flora. Endemic diatom taxa were also observed, and a multigene molecular phylogeny of Pinnularia borealis showed a high genetic diversity. Pilot studies were conducted for the microeukaryotes and cyanobacteria to select NGS protocols and bioinformatic pipelines. Preliminary multivariate analysis of over 100 samples revealed that distinct biogeographic zones could be recognized in both the prokaryote and eukaryote data, which is in agreement with the classical subdivision of the Antarctic Realm into Maritime Antarctica, Continental Antarctica and the Sub-Antarctic Islands generally observed in plants and animals. Moreover, Sub-Antarctic assemblages harboured more complex foodwebs, with quite diverse metazoan groups. Lakes on the continent, however, were characterised by fewer metazoan groups and a greater importance of microbial herbivores and secondary consumers, including a relative high diversity of ciliates and tardigrades. Variation partitioning analysis revealed that spatial variables that approximated large-scale regional contrasts in historical (e.g. deglaciation history, geological origin) and climatic factors (e.g. mean annual air temperature) significantly explained the largest portion of the observed variation in community structure for eukaryotes, while in the prokaryote data environmental gradients related to conductivity were more important. In a first analysis of microbial mats from five Antarctic lakes and an aquatic biofilm from the Sub-Antarctic, the majority of the cyanobacterial OTUs retrieved were related to filamentous taxa such as Leptolyngbya and Phormidium, which are common genera in Antarctic lacustrine microbial mats. However, other phylotypes related to different taxa such as Geitlerinema, Pseudanabaena, Synechococcus, Chamaesiphon, Calothrix and Coleodesmium were also found. Results revealed a higher diversity than what had been reported using traditional methods based on microscopic observations and cultivation and also highlighted remarkable differences between the cyanobacterial communities of the studied lakes. In the next months, the molecular diversity data will be deposited into the “Microbial Antarctic Resource System (MARS)” presently developed into the webportal ‘biodiversity.aq’. The better knowledge of the diversity and distribution of microorganisms will contribute to a better assessment of their resilience and local/regional responses to global change. [less ▲]

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See detailElucidating diversity of thin filamentous mat-forming Antarctic cyanobacteria
Lara, Yannick ULg; Durieu, Benoit ULg; Deblander, Victor ULg et al

Poster (2016, April 29)

Freshwater ecosystems range from glacial cryoecosystems, ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In ... [more ▼]

Freshwater ecosystems range from glacial cryoecosystems, ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In these mats, cyanobacteria form matrices that shelter other organisms, and carry out the primary production. Narrow filamentous cyanobacteria belonging to the genera Leptolyngbya and Phormidium are especially abundant in Antarctic microbial mats and are essential for the formation of matrix. However, the lack of morphological criteria and the small cell size of cyanobacteria belonging to these two genera make their identification problematic. Indeed, they are known as polyphyletic taxa according to botanical and bacteriological criteria. The characterization of strains is the first step for an assessment of the real diversity and for understanding their role in the environment. We designed a polyphasic approach that combines molecular analyses, environmental physiology experiments and microscopic observations. Briefly, we amplified and sequenced three loci (16S rRNA, ITS, and rpoC1) for 31 strains of Leptolyngbya and Phormidium. We performed whole genome sequencing for five strains. Cultures at different stage were observed by light and epifluorescence microscopy. Finally, selected strains were grown in nitrogen-limited. The Leptolyngbya and Phormidium strains were distributed into four lineages. Phylogenetic trees supported the distribution of P. priestleyi strains into at least two potentially new lineages, and L. antarctica strains were separated into one endemic and one cosmopolitan lineage. This was supported by the microscopic observations of 1-year old cultures. Genome analyses revealed the presence of sequences related to the production of secondary metabolites in strains from two of the studied lineages. Secondary metabolites are often known for their antimicrobial activities. Such properties would partly explain how cyanobacterial mats survive to predation and degradation by other bacteria. This work provides the first building block to the understanding of survival strategies developed by mat-forming cyanobacteria and how they succeeded as the most abundant phototrophs on the Antarctic continent. This work was realized in the frame of the BelSPo project CCAMBIO. [less ▲]

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See detailModeling in Air Transportation: Cargo Loading and Itinerary Choice
Lurkin, Virginie ULg

Doctoral thesis (2016)

We examine two problems as part of this dissertation. The first is a cargo loading problem. The aim is to load a set of containers and pallets into a cargo aircraft that serves multiple airports. Our work ... [more ▼]

We examine two problems as part of this dissertation. The first is a cargo loading problem. The aim is to load a set of containers and pallets into a cargo aircraft that serves multiple airports. Our work is the first to model cargo transport as a series of trips consisting of several legs at the end of which pickup and delivery operations might occur. This problem is crucial for airlines because in an attempt to reduce their costs, most airlines prefer to load as many containers as possible, even if all the loaded containers do not have the same final destination. Our results demonstrate that it is possible to quickly find near optimal or excellent feasible loading plans, and that our approach leads to substantial savings with respect to typical manual approaches currently used in practice. The second problem we examine involves the estimation of itinerary choice models that include price variables and correct for price endogeneity using a control function that uses several types of instrumental variables. The motivation for developing these models is to demonstrate the importance of accounting for price endogeneity and to estimate different price sensitivities as a function of advance purchase periods. This is important as the airline industry can use our results to incorporate different customer segments as revealed through high-yield and low-yield booking curves when evaluating the profitability of airline schedules. Results based on Continental U.S. markets for May 2013 departures showed that models that fail to account for price endogeneity overestimate customers' value of time and result in biased price estimates and incorrect pricing recommendations. The advanced models estimated (nested logit and ordered generalized extreme value (OGEV) models) are shown to outperform the baseline multinomial logit model with regard to statistical tests and behavioral interpretations. Additionally, results show that price sensitivities vary as a function of advance purchase periods, with those purchasing high-yield products being less price sensitive than those purchasing low-yield products (across any advance purchase periods) and those purchasing closer to departure being less price sensitive. Results also indicate that inter-alternative competition is strong for itineraries that share similar departure times. Finally, as part of the itinerary choice model developed in this dissertation, we estimate highly refined departure time of day preferences. Results are intuitive and show that departure time of day preferences vary across many dimensions including the length of haul, direction of travel, number of time zones crossed, departure day of week, and itinerary type (i.e., outbound, inbound, and one-way itineraries). To the best of our knowledge, these curves represent the most refined publicly-available estimates of airline passengers' time of day preferences. [less ▲]

Detailed reference viewed: 47 (7 ULg)