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See detailDynamics of the active region in Jupiter’s aurorae
Bonfond, Bertrand ULg; Grodent, Denis ULg; Badman, Sarah et al

Conference (2015, September 29)

The Far-UV aurorae at Jupiter variety on a wide range of timescales. This study focuses on the dynamics of the active region on timescales of a few minutes. Up to now, only the time-tag mode of the Space ... [more ▼]

The Far-UV aurorae at Jupiter variety on a wide range of timescales. This study focuses on the dynamics of the active region on timescales of a few minutes. Up to now, only the time-tag mode of the Space Telescope Imaging Spectrograph provides access to such fast variations with a high spatial resolution. This active region, located on the dusk flank of the area inside the main auroral oval, is the locus of particularly bright (up to several mega Reyleighs) and sudden (a few tens of seconds) enhancements called flares. A previous study also showed that these flare could reoccur quasi-periodically every 2-3 minutes and propagate from dusk to dawn. Here we use data obtained in 2013 and 2014 to show that this quasi-periodic behavior is only present on half of the cases and that the affected region could either cover the whole active region or a much smaller area (∼5000km^2). We also found areas that were still during part of the observation sequence and then began to blink (see Figure 1). We also show that there no systematically preferred propagation direction. Finally, sequences acquired successively in the two hemispheres show that the quasi-periodic flares can be in phase [less ▲]

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See detailLes mains de l'Enseignement d'Amennakhte. Reconnecter le littéraire au documentaire
Polis, Stéphane ULg

Scientific conference (2015, September 29)

Dans cet exposé, je décris la redécouverte par les égyptologues de l'Enseignement d'Amennakhte en accordant une attention particulière aux mains hiératiques des scribes qui ont rédigé les témoins connus ... [more ▼]

Dans cet exposé, je décris la redécouverte par les égyptologues de l'Enseignement d'Amennakhte en accordant une attention particulière aux mains hiératiques des scribes qui ont rédigé les témoins connus de ce texte majeur de la 20e dynastie. Cette approche permet d'aboutir à trois conclusions principales. (1) Il n'est pas possible de montrer l'existence d'une véritable "école de mains" qui imiteraient celle du scribe de la Tombe Amennakhte (e.g. Eyre 1979 : 87). (2) Il est possible d'attribuer différents témoins du texte de l'Enseignement à une même main. (3) On peut établir le lien ferme entre des mains ayant copiés l'Enseignement d'Amennakhte et des mains documentaires connues de la première moitié de la 20e dynastie. Ce dernier point permet de revenir sur le mythe égyptologique d'une césure significative entre mains littéraires et mains documentaires : malgré certaines différences, la possibilité de suivre la main d'un scribe entre textes littéraires et documentaires est réelle. Cela n'est évidemment pas sans conséquences pour l'histoire culturelle de la Communauté de Deir el-Médineh. [less ▲]

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See detailStatistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in the Saturn's outer magnetosphere
Palmaerts, Benjamin ULg; Roussos, Elias; Krupp, Norbert et al

Poster (2015, September 29)

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See detailHull Optimization of Medium-Speed Monohull Passenger Ferries
Hetharia, Wolter Roberth ULg

Doctoral thesis (2015)

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See detailLes sols, richesses cachées de la planète
Garré, Sarah ULg; Carnol, Monique ULg; Cornelis, Jean-Thomas ULg

Speech/Talk (2015)

Toute forme de vie sur terre doit beaucoup aux sols. Aussi discrets que dynamiques, vitaux que complexes, les sols sont des réacteurs bio-physico-chimiques, situés à l’interface entre les roches, la ... [more ▼]

Toute forme de vie sur terre doit beaucoup aux sols. Aussi discrets que dynamiques, vitaux que complexes, les sols sont des réacteurs bio-physico-chimiques, situés à l’interface entre les roches, la végétation, l’air et l’eau. L’étude de cette ressource non renouvelable, soumise à des pressions croissantes, requiert une approche interdisciplinaire, indispensable pour une gestion raisonnée et durable des écosystèmes. Comment sont définis les sols, comment les étudions-nous, comment aborder leur diversité et leurs fonctionnalités ? Quels secrets ont-ils à nous livrer ? La leçon inaugurale abordera la formation des sols, leur diversité ainsi que leurs fonctions écologiques. La variété des organismes au sein des sols et la notion de qualité des sols seront évoquées à travers la triangulation biodiversité – fonctions – services écosystémiques. Des techniques innovantes, permettant d’étudier cette interface extrêmement complexe et diversifiée, seront présentées et le fonctionnement ainsi que l’intérêt des sols seront illustrés par des exemples concrets issus de recherches récentes. [less ▲]

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See detailExperimental and in silico approaches to study the interaction of Remorin with plant plasma membrane : specific interaction of the C-term domain with lipids
Deleu, Magali ULg; Nasir, Mehmet Nail ULg; Gronnier, Julien et al

Conference (2015, September 29)

The function of Remorins, a diverse family of plant-specific proteins (1) is far to be fully elucidated. One of them, StREM1.3 (for Solanum tuberosum Remorin from group 1, homolog 3) has been reported to ... [more ▼]

The function of Remorins, a diverse family of plant-specific proteins (1) is far to be fully elucidated. One of them, StREM1.3 (for Solanum tuberosum Remorin from group 1, homolog 3) has been reported to regulate cell-to-cell propagation of the potato virus X (2). It was also shown to be localized to the inner leaflet of plasma membranes (PMs) and along plasmodesmata, bridges connecting neighbor cells essential for cell-to-cell communication in plants (3). The mechanisms driving StREM1.3 association with PM is still an open question. It was shown recently that a domain of 28 residues at the C-terminus of the potato (RemCA) is required and sufficient for anchoring to the PM (4). Here we combined experimental and in silico biophysics to unravel the molecular bases of RemCA membrane binding. Biomimetic membrane models of plant PM such as monolayers and liposomes were used with various biophysical techniques (Langmuir monolayer technique, Fourier-transformed infrared spectroscopy, circular dichroïsm) and modeling tools (home-made methods and molecular dynamics) (5) to answer to three questions: (i) What is the conformation adopted by RemCA within a membrane?, (ii) Is there any membrane lipid specificity in the RemCA-membrane binding? (iii) What is the role of the two different RemCA domains in the interaction? Results show that RemCA displays a preference for plant phosphoinositide and sitosterol-enriched inner leaflet plasma membrane rafts. Within the membrane, the C-terminal and the N-terminal domains adopt a random coil and a -helical conformation respectively. The C-terminal domain acts as a driver to bind RemCA to the membrane while the N-terminal domain stabilizes the peptide at the membrane. Lysine residues have a crucial importance in this interaction. References (1) Raffaele et al., Plant Physiol., 2007, 145: 593–600 (2) Raffaela et al., Plant Cell, 2009, 21: 1541–1555. (3) Maule, Curr. Opin. Plant Biol., 2008, 11: 680–686. (4) Perraki et al., Plant Physiology, 2012, 160 : 624-637. (5) Deleu et al., Biochim. Biophys. Acta – Biomembranes, 2014, 1838 : 3171-3190. [less ▲]

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See detailHyporeactivity of Alveolar Macrophages and Higher Respiratory Cell Permissivity Characterize DBA/2J Mice Infected by Influenza A Virus Hyporeactivity of Alveolar Macrophages and Higher Respiratory Cell Permissivity Characterize DBA/2J Mice Infected by Influenza A Virus.
Casanova Bustos, Tomas Ronaldo ULg; Van de Paar, Els; Desmecht, Daniel ULg et al

in JOURNAL OF INTERFERON & CYTOKINE RESEARCH (2015), 35(10), 808-820

Influenza A virus remains a major public health problem. Mouse models have been widely used to study influenza infection in mammals. DBA/2J and C57BL/6J represent extremes in terms of susceptibility to ... [more ▼]

Influenza A virus remains a major public health problem. Mouse models have been widely used to study influenza infection in mammals. DBA/2J and C57BL/6J represent extremes in terms of susceptibility to influenza A infection among inbred laboratory mouse strains. Several studies focused specifically on the factors responsible for the susceptibility of DBA/2J or the resistance of C57BL/6J and resulted in impressive lists of candidate genes or factors over- or underexpressed in one of the strains. We adopted a different phenotypical approach to identify the critical steps of the infection process accounting for the differences between DBA/2J and C57BL/6J strains. We concluded that both a dysfunction of alveolar macrophages and an increased permissivity of respiratory cells rendered DBA/2J more susceptible to influenza infection. [less ▲]

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See detailTrace metal speciation? An essential aspect of biomonitoring to avoid wrong conclusions
Richir, Jonathan ULg; Lepoint, Gilles ULg; Donnay, Annick et al

Poster (2015, September 29)

The Mediterranean mussel Mytilus galloprovincialis is widely used as a bioindicator species in active monitoring surveys. As a filter feeder artificially maintained in the water column, it bioaccumulates ... [more ▼]

The Mediterranean mussel Mytilus galloprovincialis is widely used as a bioindicator species in active monitoring surveys. As a filter feeder artificially maintained in the water column, it bioaccumulates trace metals from the surrounding water in their dissolved and particulate forms. However, most monitoring surveys don’t take into account that speciation aspect when studying trace metal accumulation kinetics in mussels. In the framework of the STARECAPMED project, we monitored trace metal concentrations in the flesh of mussels together with their “most bioavailable” dissolved and particulate fractions in the water column for almost 5 months (February-June 2011). Mussels were purchased from 2 little contaminated French shellfish farms (SARL Etang de Diane and ferme marine des Aresquiers), placed in several pouches to allow regular sampling, and immerged near the Oceanographic Research Station STARESO in the Calvi bay, northwestern Corsica. Mussels and water samples for suspended matter filtration were collected every week to two weeks, as were deployed DGTs. Seawater samples were filtered through 47 mm hydrophilic PTFE membrane filters with a 0.45 µm pore size until clogging. In the laboratory, mussel flesh and filters were digested in Teflon vessels with acids (HNO3/H202) in a closed microwave digestion lab station. DGT resins were eluted for 24h in 1.0 M HNO3. Trace metal concentrations (Cr, Mn, Co, Ni, Cu, Zn, Ag, Cd, Pb) were measured by DRC-ICP-MS. Analytical accuracy was checked by analyzing CRMs. All the studied metals except Pb and Zn were present in the water column to over 80% in their dissolved form. The contribution of the dissolved pathway was thus likely to be predominant in the oligotrophic Calvi bay. Dissolved trace metals showed little temporal variability of their levels, likely resulting from the integration over time of their levels in the DGT probes and the lack of seasonality of this fraction. In contrast, Zn showed great variability of its particulate fraction during the survey. Such temporal variability was also observed for Cr, more abundant in its particulate form at the end of the survey, and for Mn and Pb that conversely tended to decrease. The dynamic of trace metals in the mussel flesh is regulated by the environmental bioavailability of dissolved and particulate metals, the ecophysiological status of mussels and the trophic conditions of the water body. In the oligotrophic Calvi bay, showing background contamination levels by metals, the trophic conditions played a major role once out of the spring plankton bloom. It led to the increase of metal concentrations measured in the flesh of mussels undergoing starvation. However, some metals such as Cu and Co displayed only little temporal variations of their concentrations, these essential micronutrients being well regulated. The combined study of trace metal bioavailability and mussel ecophysiology in defined environmental conditions allows discriminating against biotic and abiotic factors regulating contaminant uptake in mussels, thus avoiding wrong conclusions about the observed dynamics of the studied contaminants. Mussels are a good proxy of coastal water quality, but their proper use notably requires adjustment of raw contaminant concentrations with trophic status of monitored sites. [less ▲]

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See detailBetter tests better care : Syndrome-based diagnostics for respiratory tract infections
MELIN, Pierrette ULg

Conference (2015, September 29)

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See detailWhy Facebook is flying up high and Twitter can't fly away
Artige, Lionel ULg

Article for general public (2015)

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See detailMultifractality of quantum wave functions in the presence of perturbations
Dubertrand, Rémy ULg; Garcia-Mata, Ignacio; Georgeot, Bertrand et al

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2015), 92

We present a comprehensive study of the destruction of quantum multifractality in the presence of perturbations. We study diverse representative models displaying multifractality, including a ... [more ▼]

We present a comprehensive study of the destruction of quantum multifractality in the presence of perturbations. We study diverse representative models displaying multifractality, including a pseudointegrable system, the Anderson model, and a random matrix model. We apply several types of natural perturbations which can be relevant for experimental implementations. We construct an analytical theory for certain cases and perform extensive large-scale numerical simulations in other cases. The data are analyzed through refined methods including double scaling analysis. Our results confirm the recent conjecture that multifractality breaks down following two scenarios. In the first one, multifractality is preserved unchanged below a certain characteristic length which decreases with perturbation strength. In the second one, multifractality is affected at all scales and disappears uniformly for a strong-enough perturbation. Our refined analysis shows that subtle variants of these scenarios can be present in certain cases. This study could guide experimental implementations in order to observe quantum multifractality in real systems. [less ▲]

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See detailÀ propos de l'O. Caire JdE 72460 : faut-il continuer la quête de la tombe d'une reine de la XIXe dynastie dans la Vallée des Rois ?
Dorn, Andreas; Polis, Stéphane ULg

Scientific conference (2015, September 28)

Cet exposé s'articule en trois parties. (1) Nous proposons d'abord une introduction présentant l'état de l'art sur cet ostracon, dont le texte mentionne des distances entre différents lieux de la ... [more ▼]

Cet exposé s'articule en trois parties. (1) Nous proposons d'abord une introduction présentant l'état de l'art sur cet ostracon, dont le texte mentionne des distances entre différents lieux de la Nécropole thébaine et a été récemment utilisé pour tenter de localiser une tombe perdue, celle d'Isisnofret, dans la Vallée des Rois. (2) Nous proposons ensuite une traduction du texte du recto (ancien verso) et discutons les problèmes d'identification entre endroits mentionnés et structures archéologiques connues. (3) Nous passons ensuite à un examen du texte du verso (ancien recto) et construisons une représentation schématique des relations entre les emplacements mentionnés. Nous essayons alors de voir si cette schématisation abstraite correspond à des lieux connus dans la Vallées des Rois ou dans la Vallée des Reines. Nous concluons par la négative et proposons de renverser la perspective : les structures mentionnées sont à chercher au sein de la Tombe des fils de Ramsès II (KV 5) et non à l'extérieur dans la Vallée des Rois. [less ▲]

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See detailHigh-throughput sequencing of toxins with pharmacological interest: proof of concept and first applications
Echterbille, Julien ULg; Degueldre, Michel ULg; Boulanger, Madeleine ULg et al

Conference (2015, September 28)

Animal venoms are complex chemical cocktails, comprising wide ranges of biologically active reticulated peptides that target with high selectivity and efficacy varieties of membrane receptors. Assuming ... [more ▼]

Animal venoms are complex chemical cocktails, comprising wide ranges of biologically active reticulated peptides that target with high selectivity and efficacy varieties of membrane receptors. Assuming the fact that each of the 170,000 venomous species reported can produce more than 250 bioactive toxins, at least 40,000,000 bioactive peptides and proteins may be discovered. Among the four described species of mambas, Eastern Jameson’s mamba (Dendroaspis jamesonii kaimosae) venom is the less characterized since only 9 peptides are referenced in database. This work aims at developing a new strategy devoted to the deep analysis of animal venoms. Our approach consists in a first separation of the venom using cation exchange chromatography. Each primary fraction is then purified a second time by classical RP-HPLC. A total of 328 fractions, containing amongst 1 and 4 toxins, are finally collected. MALDI-MS analysis of each fraction is done in order (1) to obtain information about masses and (2) to obtain sequences of toxins thanks to MALDI-In Source Decay (ISD) dissociation coupled with on MALDI target plate reduction of the peptides. ISD has already been demonstrated efficient for toxin sequencing1, and especially when using 1,5-DAN as reducing matrix2. ISD yields to sequences that cover more than 50% of peptide sequences by series of singly charged c-type ions. Thanks to this methodology, we were able to obtain 85% of satisfactory results i.e. spectra giving quite long tags of amino acids (up to 20 residues). As a way to validate our method, a tag coming from ISD spectrum interpretation has found a match in database for an Eastern Jameson’s mamba toxin. The global sequence has then been obtained by extrapolation on the ISD spectrum. Since ISD spectra are simpler than classical MS/MS spectra, automation of spectra interpretation, difficult with other fragmentation techniques (CID, ETD…), is implementable. In the near future, sequences obtained with this approach will be used to direct tests of biological activity through sequence homologies with already known ligands for different kinds of membrane receptors. [less ▲]

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See detailLe projet expérimental multidisciplinaire (PEMD) en 3ème Bachelier à Gembloux
Colaux-Castillo, Catherine; Pochet, Bernard ULg

in Former aux compétences informationnelles à l'heure du web 2.0 et des discovery tools (2015, September 28)

Cette courte présentation, dans l'atelier 3 du colloque ILIB15, décrit l'intégration d'un cours (« littérature scientifique et méthodologie documentaire »), dont le titulaire est un bibliothécaire, dans ... [more ▼]

Cette courte présentation, dans l'atelier 3 du colloque ILIB15, décrit l'intégration d'un cours (« littérature scientifique et méthodologie documentaire »), dont le titulaire est un bibliothécaire, dans une unité d’apprentissage intégrée basée sur la résolution d'un problème concret de recherche dans un contexte scientifique non familier. Ce cours a été proposé pour la première fois durant l'année académique 2014-2015 à une partie des étudiants du bloc trois du Master Bioingénieur, orientation Sciences et technologies de l’environnement de l'Université de Liège. Cette activité se déroule en plusieurs phases sur les deux quadrimestres. [less ▲]

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See detailMilk production, milking frequency and rumination time of grazing dairy cows milked by a mobile milking robot.
Lessire, Françoise ULg; Hornick, Jean-Luc ULg; Minet, Julien ULg et al

in Conington, J; Klopcic, M; Lauridsen, C (Eds.) et al Book of abstracts of the 66th Annual meeting of the European Federation of animal science (2015, September 28)

In Europe, analysis of meteorological data shows that the average temperature has increased by ~1°C over the past hundred years (IPCC, 2013). Heat stress periods are thus expected to be more frequent even ... [more ▼]

In Europe, analysis of meteorological data shows that the average temperature has increased by ~1°C over the past hundred years (IPCC, 2013). Heat stress periods are thus expected to be more frequent even in temperate areas. The use of an automatic milking system (AMS) implies the need to stimulate cows’ traffic to the robot, especially with grazing cows. Describing how heat stress influenced cows’ traffic to the robot is the aim of this study. Grazing dairy cows milked by an automatic system (AMS) experienced heat stress (HS) periods, twice during the summer 2013 in July (J) and August (A). The daily temperature humidity index (THI) during these periods were higher than 75. Each HS period was compared with a “normal period”(N), presenting the same number of cows, similar lactation number, days in milk, distance to come back to the robot and an equal access to water. The first HS period of 5 days with a mean THI of 78.4 was chosen in J, and a second that lasted for 6 days in A with a THI value of 77.3. Heat stress periods were cut off with the same duration of days with no stress (N) and mean THI <70. Milk production, milkings and refusals to the robot during HS were compared with N periods. Milkings and refusals were significantly more numerous in HS periods in July (HS: 2.54 ± 0.11 vs N: 2.19 ± 0.08, 1.87 ± 0.20 vs 0.72 ± 0.16) but milk production dropped from 21.8 ±0.6 kg per cow and per day during N periods to 18.9 ± 0.8 kg in HS. In August, MY increased slightly during HS. This could be explained by less high ambient temperatures and decreased distance to walk inducing less energy expenditure. The increase in milkings and refusals to the robot during HS could be linked to water availability nearby the robot and confirmed previous findings (Lessire et al., 2014). [less ▲]

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See detailPsychological benefits of a multidisciplinary rehabilitation program after breast cancer
Leclerc, Anne-France ULg; FOIDART-DESSALLE, Marguerite ULg; Bury, Thierry ULg et al

Conference (2015, September 27)

Background : Breast cancer is the most frequent cancer in women, affecting 8 women out of 100. With early detection and improved treatments, the number of deaths linked to this disease has declined ... [more ▼]

Background : Breast cancer is the most frequent cancer in women, affecting 8 women out of 100. With early detection and improved treatments, the number of deaths linked to this disease has declined. However, the disease and its treatments are at the origin of many undesirable side effects such as fatigue, anxiety, weight gain and sleep disorders. The objective of this study is to determine the psychological benefits of a multidisciplinary rehabilitation program among women treated for breast cancer (on average six months after the end of the adjuvant radiotherapy or chimiotherapy). Material and methods : 122 patients were included into a control group (n = 61) and a treated group (n = 61). All participants were submitted to evaluations before the beginning of the trial and after three months. These evaluations included different questionnaires exploring the quality of life, anxiety, depression and various functions and other symptoms related to cancer (EORTC QLQ-C30, EQ-5D, STAI, HADS) and functional assessments. The control group has received no intervention unlike the treated group that received a three-month rehabilitation including supervised physical training (90 min) with three times a week and various psycho-educational sessions (120 min) once a week. Results : After three months, the health status (quality of life) (p < 0,0001), the functional role (p = 0,031), emotional state (p < 0,0001) and physical (p = 0,0045), cognitive (p = 0,0027) and social functions (p = 0,0018) improve significantly in the treated group. This observation also applies to symptoms of fatigue (p < 0,0001), insomnia (p < 0,0001), pain (p = 0,002), dyspnea (p = 0,009), loss of appetite (p = 0,04), anxiety (p < 0,0001) and depression (p < 0,0001) as well as physical parameters obtained through functional assessments. In the control group, these improvements do not appear. Conclusions : This study shows the feasibility and psychological benefits of such a multidisciplinary oncological rehabilitation program in women after their treatments for breast cancer. Additional studies are needed to know the optimal time of beginning (during treatments or after them) and the optimal management time for this support. [less ▲]

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See detailRamses Online. Un outil pour aider à l'édition de textes hiératiques
Polis, Stéphane ULg

Scientific conference (2015, September 27)

Après une présentation générale des fonctionnalités de Ramses Online (http://ramses.ulg.ac.be), cette intervention vise à montrer comment l'outil en question peut être utilisé pour l'identification de ... [more ▼]

Après une présentation générale des fonctionnalités de Ramses Online (http://ramses.ulg.ac.be), cette intervention vise à montrer comment l'outil en question peut être utilisé pour l'identification de textes littéraires inédits et, plus largement, l'aide à la lecture d'originaux rédigés en hiératique. [less ▲]

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