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See detailLa dépression chez l'adolescent: Mieux comprendre pour mieux agir
Boulard, Aurore ULg

Conference given outside the academic context (2014)

La dépression à l’adolescence fait depuis quelques années l’objet d’études épidémiologiques. Chez les adolescents, les taux de prévalence varient de 5 à 7% pour l’épisode dépressif majeur (EDM) et touche ... [more ▼]

La dépression à l’adolescence fait depuis quelques années l’objet d’études épidémiologiques. Chez les adolescents, les taux de prévalence varient de 5 à 7% pour l’épisode dépressif majeur (EDM) et touche deux fois plus de filles que de garçons. Selon une estimation, deux tiers d’entre eux ne seraient pas médicalement et/ou psychologiquement soignés. Pourtant les conséquences de ces épisodes dépressifs sont nombreuses et graves: troubles du caractère, échecs scolaires, conduites suicidaires. Un rapport récent de l’OMS montre qu’à l’heure actuelle, la dépression chez les adolescents âgés de 12 à 19 ans est la première cause de maladie et de handicap. Face à ce constat, il est de la plus haute importance de mieux comprendre cette maladie qui ne s’exprime pas de la même manière qu’à l’âge adulte et se confond régulièrement avec la « crise d’adolescence » afin de pouvoir prendre en charge ces adolescents et les aider. [less ▲]

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See detailPollution and Siltation of Rivers in the Western Highlands of Cameroon: a Consequence of Farmland Erosion by Runoff
Djoukeng, Henri Grisseur ULg; Tankou, Christopher Mubeteneh; Degré, Aurore ULg

Conference (2014, November 05)

In the western highlands agro-ecological zone of Cameroon, rivers are constantly silted and polluted with waste from cultivated plots. This study investigated on the characterization and quantification of ... [more ▼]

In the western highlands agro-ecological zone of Cameroon, rivers are constantly silted and polluted with waste from cultivated plots. This study investigated on the characterization and quantification of sediment from plots cultivated in the watershed Méloh; among these sediment we highlighted soil, plant residues, chemical packages and plastic casing used for irrigation. In a natural rocky bottom wells, we performed for a period of three years the collection, differentiation and measurement of trapped sediment in the cultivated part of river that runs through the watershed. The total cultivated area is about 7.5 ha; slopes are operated between 14% and 17%. During the years 2012 and 2013 where farmers practiced both flatbed and ridging along the steepest slope, two methods of land preparation that do not contribute positively to water conservation, we collected an average of 10.429 t.ha-1. During the 2013 crop year, with the participation of curious farmers we experimented tied ridging in a potato; this technique was adopted on 75% of plots in 2014 and we collected 3.586 t.ha-1, a decrease of 65.61% compared to the average of previous years. This study showed that traditional agricultural practices are a cause of siltation and pollution of the Méloh river, thus almost all rivers in the study area by what the topography is similar and agriculture the main activity. Tied ridging significantly reduced siltation of rivers; it is thus an effective technique to fight against water pollution in mountain agriculture. [less ▲]

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See detailBlackouts: des vérités qui dérangent
Ernst, Damien ULg

Speech (2014)

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See detailÉmissions gazeuses en production porcine
Philippe, François-Xavier ULg

Conference (2014, November 04)

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See detailSouthern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection
Sana, H.; Le Bouquin, J.-B.; Lacour, S. et al

in Astrophysical Journal Supplement Series (2014), 215

Multiplicity is one of the most fundamental observable properties of massive O-type stars and offers a promising way to discriminate between massive star formation theories. Nevertheless, companions at ... [more ▼]

Multiplicity is one of the most fundamental observable properties of massive O-type stars and offers a promising way to discriminate between massive star formation theories. Nevertheless, companions at separations between 1 and 100 milliarcsec (mas) remain mostly unknown due to intrinsic observational limitations. At a typical distance of 2 kpc, this corresponds to projected ph [less ▲]

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See detailSupercritical Carbon Dioxide Assisted Impregnation to Prepare Drug-eluting Polymer Implants
Champeau, Mathilde ULg

Doctoral thesis (2014)

The scCO2 impregnation process is a promising alternative to other manufacturing process to prepare drug-eluting polymer implants. This work enabled to rationalize the influence of the key parameters ... [more ▼]

The scCO2 impregnation process is a promising alternative to other manufacturing process to prepare drug-eluting polymer implants. This work enabled to rationalize the influence of the key parameters governing this process and to determine in which extent this process can be used to prepare drug-eluting implants. We have combined the information obtained with traditional polymer characterization techniques and a newly characterization set-up we have developed that is based on in situ FTIR micro-spectroscopy. We have worked on the impregnation of sutures made of PLLA, PP and PET with two anti-inflammatory drugs namely ketoprofen and aspirin. Firstly, the thermodynamic behaviors of the systems drug/CO2 (solubility and speciation of the drug) and polymer/CO2 (CO2 sorption, polymer swelling, evolution of the polymer microstructure and of the tensile properties) were studied as a function of pressure and temperature. Then, the scCO2 impregnation process was investigated. The impact of the operational conditions on the drug loading (contact time, pressure, temperature and depressurization conditions) was explored and accounted regarding to the CO2 sorption, the swelling, the drug solubility as well as the changes in the polymer microstructure with the experimental conditions and the presence of the drug. The drug/polymer affinity was also explored. The tensile properties of the impregnated fibers were also evaluated. PLLA was more impregnated (up to 32%) than PP and PET (up to 5%) in the investigated conditions. Finally, we have shown that the drug release can be tuned from 3 days to 3 months by varying the impregnation and depressurization conditions on the system PLLA/Ketoprofen. [less ▲]

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See detailLe nouveau cadre d’action en matière de climat et d’énergie à l’horizon 2030
Habran, Maxime ULg

E-print/Working paper (2014)

Cette note a pour but de fournir un éclairage sur le nouveau cadre d'action européen en matière de climat et d'énergie

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See detailLes formations cambro-ordoviciennes du Massif de Stavelot et le conglomérat permien (Poudingue de Malmedy), sur les cartes Harzé- La Gleize et Stavelot - Malmedy.
Lamberty, Pauline ULg; Marion, Jean-Marc ULg

Diverse speeche and writing (2014)

Livret-guide de l'excursion réalisée dans le cadre du Programme* de Révision de la carte géologique de la Wallonie (*commandé par le SPW). La journée est dédiée aux formations cambriennes (Wanne, La Venne ... [more ▼]

Livret-guide de l'excursion réalisée dans le cadre du Programme* de Révision de la carte géologique de la Wallonie (*commandé par le SPW). La journée est dédiée aux formations cambriennes (Wanne, La Venne et La Gleize), ordoviciennes (Jalhay et Ottré), ainsi qu'aux dépôts conglomératiques permiens, connus sous le nom de "Poudingue de Malmedy" qui affleurent dans le Massif de Stavelot (localités de Trois-Ponts, Stavelot, Basse-Bodeux, Stoumont, ainsi que la vallée de la Lienne). [less ▲]

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See detailOccurence of Satellite RNAs associated with Cucumber mosaic virus isolated from banana (Musa sp.) in Ivory Coast
Kouadio, Kouakou Théodore; De Clerck, Caroline ULg; Agneroh, TA et al

in British Society for Plant Pathology - New Disease Reports (2014), 30

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See detailA Phylogenomic analysis of the origin of plastids
Cornet, Luc ULg; Javaux, Emmanuelle ULg; Wilmotte, Annick ULg et al

Conference (2014, November 03)

Cyanobacteria are a morphologically diverse phylum, with their first occurrence dating from the Precambrian. Oxygenic photosynthesis appeared in this group during the same geological period. Several ... [more ▼]

Cyanobacteria are a morphologically diverse phylum, with their first occurrence dating from the Precambrian. Oxygenic photosynthesis appeared in this group during the same geological period. Several publications have established, without any doubt, that plastids (both primary and complex) form a monophyletic ensemble emerging from Cyanobacteria. However, the exact position of plastids within Cyanobacteria is still uncertain, with several recent papers leading to very different hypotheses. Here we present a phylogenomic analysis of the origin of plastids. Our study takes advantage of all the available genomes and thus represents the best taxonomic sampling seen so far: 140 genomes of Cyanobacteria, 101 genomes of plastids and 27 outgroups taken in Melainabacteria and Chloroflexi. It esults in an analysis using state-of- the-art methods (e.g., orthology assessment using USEARCH and rthoMCL, phylogenetic inference using CAT and CAT-GTR models) based on more than 160 protein alignments totalizing over 20,000 unambiguously aligned amino acids. To confirm our results, we performed gene jackknife inferences and gene reconciliation analyses on the same dataset. We expect that out approach accounts for potential phylogenetic artefacts due to changes in the evolutionary process having occurred when the guest cyanobacterium became an endosymbiont and eventually a plastid. Meanwhile, we improve the phylogeny of Cyanobacteria per se, notably because of the presence of Melainabacteria in our dataset. [less ▲]

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See detailSearching for faint companions with VLTI/PIONIER. II. 92 main sequence stars from the Exozodi survey
Marion, Lindsay ULg; Absil, Olivier ULg; Ertel, S. et al

in Astronomy and Astrophysics (2014), 570

Context. The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been ... [more ▼]

Context. The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been carefully selected to avoid the presence of binary stars, the results of this survey can still be biased by the presence of unidentified stellar companions. <BR /> Aims: Using the PIONIER data set collected within the Exozodi survey in 2012, we aim to search for the signature of point-like companions around the Exozodi target stars. <BR /> Methods: We make use of both the closure phases and squared visibilities collected by PIONIER to search for companions within the ~100 mas interferometric field of view. The presence of a companion is assessed by computing the goodness of fit to the data for a series of binary models with various separations and contrasts. <BR /> Results: Five stellar companions are resolved for the first time around five A-type stars: HD 4150, HD 16555, HD 29388, HD 202730, and HD 224392 (although the companion to HD 16555 was independently resolved by speckle interferometry while we were carrying out the survey). In the most likely case of main sequence companions, their spectral types range from A5V to K4V. Three of these stars were already suspected to be binaries from Hipparcos astrometric measurements, although no information was available on the companions themselves so far. In addition to debiasing the statistics of the Exozodi survey, these results can also be used to revise the fraction of visual binaries among A-type stars, suggesting that an extra ~13% A-type stars are visual binaries in addition to the ones detected in previous direct imaging surveys. <BR /> Conclusions: We estimate that about half the population of nearby A-type stars could be resolved as visual binaries using a combination of state-of-the-art interferometry and single-aperture imaging, and we suggest that a significant fraction of these binaries remains undetected to date. [less ▲]

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See detailA near-infrared interferometric survey of debris-disk stars. IV. An unbiased sample of 92 southern stars observed in H band with VLTI/PIONIER
Ertel, S.; Absil, Olivier ULg; Defrere, D. et al

in Astronomy and Astrophysics (2014), 570

Context. Detecting and characterizing circumstellar dust is a way to study the architecture and evolution of planetary systems. Cold dust in debris disks only traces the outer regions. Warm and hot ... [more ▼]

Context. Detecting and characterizing circumstellar dust is a way to study the architecture and evolution of planetary systems. Cold dust in debris disks only traces the outer regions. Warm and hot exozodiacal dust needs to be studied in order to trace regions close to the habitable zone. <BR /> Aims: We aim to determine the prevalence and to constrain the properties of hot exozodiacal dust around nearby main-sequence stars. <BR /> Methods: We searched a magnitude-limited (H <= 5) sample of 92 stars for bright exozodiacal dust using our VLTI visitor instrument PIONIER in the H band. We derived statistics of the detection rate with respect to parameters, such as the stellar spectral type and age or the presence of a debris disk in the outer regions of the systems. We derived more robust statistics by combining our sample with the results from our CHARA/FLUOR survey in the K band. In addition, our spectrally dispersed data allowed us to put constraints on the emission mechanism and the dust properties in the detected systems. <BR /> Results: We find an overall detection rate of bright exozodiacal dust in the H band of 11% (9 out of 85 targets) and three tentative detections. The detection rate decreases from early type to late type stars and increases with the age of the host star. We do not confirm the tentative correlation between the presence of cold and hot dust found in our earlier analysis of the FLUOR sample alone. Our spectrally dispersed data suggest that either the dust is extremely hot or the emission is dominated by the scattered light in most cases. The implications of our results for the target selection of future terrestrial planet-finding missions using direct imaging are discussed. [less ▲]

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See detailBiostratigraphic and chemostratigraphic constraints of the Mbuji-Mayi Supergroup (Meso-Neoproterozoic age), Democratic Republic of Congo.
Kabamba Baludikay, Blaise ULg; Bekker, Andrey; Baudet, Daniel et al

Conference (2014, November 03)

The Mbuji-Mayi Supergroup is a sedimentary sequence unaffected by regional metamorphism [1]. It was deposited between 1174 ± 22 Ma and ca. 800 Ma in the intracratonic failed-rift SMLL “Sankuru-Mbuji-Mayi ... [more ▼]

The Mbuji-Mayi Supergroup is a sedimentary sequence unaffected by regional metamorphism [1]. It was deposited between 1174 ± 22 Ma and ca. 800 Ma in the intracratonic failed-rift SMLL “Sankuru-Mbuji-Mayi- Lomami- Lovoy” basin [2] which extends from SE to NW between Katanga and Kasai Provinces. And overlies the Mesoproterozoic Kibaran Belt Supergroup (in the eastern part of SMLL basin) while in the Western part, where we focused our work, it rests unconformably upon Archean Dibaya Granitic Complex [3]. The amygdaloidal basaltic pillow lavas (948 ± 20 Ma) overlie the Mbuji-Mayi Supergroup, at the confluence of Mbuji-Mayi and Sankuru rivers [4]. Lithostratigraphically, this Supergroup consists in two distinct successions: a lower siliciclastic sequence (~500m) of BI Group and an upper carbonatic sequence (~1000m) with stromatolitic build-ups and black shales of BII Group [2]. Our own and previous sedimentological observations [5] indicate facies ranging from subtidal, low-energy stromatolitic environments to overlying intertidal to supratidal evaporitic settings of lagoon and sabkha. Here we present data on microfossil diversity and carbon isotope chemostratigraphy from the Kanshi, Lubi and Kafuku drillholes. The well-preserved and diverse assemblage of acritarchs and filamentous forms includes prokaryotes and eukaryotes, and is similar to other coeval assemblages described worldwide outside of Africa. The presence of the acanthomorph acritarch Trachyhystrichosphaera aimika is significant as it is indicative of the late Meso- to early Neoproterozoic age elsewhere, and is reported for the first time in Central Africa. So far, 56 species belonging to 31 genera were identified, dramatically increasing the previously reported diversity [6, 7]. Chemostratigraphy based on δ13Ccarb values for 290 samples, records, for the BI Group, predominantly negative values down to -8 to -9 ‰ VPDB with few samples having more positive, up to +3 ‰, values. Although the siliciclastics-rich sediments in the lower part of the BI Group likely record early diagenetic signal, carbonates in the upper part of the BI Group show similar patterns in both the Lubi and Kafuku drill cores with the sharp fall from +1 to +3 ‰ values to -8 to -7 ‰ and recovery back to +1 ‰ values over 40 to 70 m of section. The BII Group shows a less dramatic rise from -1 ‰ to +4 to +5 ‰ over more than 150 m of section. These large-scale variations differ from the steady-state carbon cycle of the late Mesoproterozoic [8] and are typical of the early Neoproterozoic record [9]. The project is supported by the EU FP7 ERC Stg ELITE. [less ▲]

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See detailEconomic Statistical Design of the VP( X) ̅ Control Charts for Monitoring a Process under Non-normality
Seif, Asghar; Faraz, Alireza ULg; Saniga, Erwin

in International Journal of Operational Research (2014)

Recent studies proved that variable parameters (VP) X ̅ control charts not only detects process mean shifts quicker than the classical X ̅ control chart but also has better economic properties ... [more ▼]

Recent studies proved that variable parameters (VP) X ̅ control charts not only detects process mean shifts quicker than the classical X ̅ control chart but also has better economic properties. Furthermore, like most papers in control chart design, the fundamental assumption is that process data are normally distributed. Nevertheless, process quality variables may not be normal in application. In this paper, we investigate the economic statistical design of the VP X ̅ control chart when the underlying process distribution is non-normal. We illustrate the design procedure and perform a sensitivity analysis on the process and cost parameters based upon the degrees of skewness and kurtosis of the population using an industrial application. [less ▲]

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See detailLe langage et l’homme
Dubuisson, Francois ULg

in Bulletin d'Analyse Phénoménologique [En ligne] (2014), 10(11),

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See detailBuilding galaxies, stars, planets and the ingredients for life between the stars. The science behind the European Ultraviolet-Visible Observatory
Gómez de Castro, Ana I.; Appourchaux, Thierry; Barstow, Martin A. et al

in Astrophysics and Space Science (2014), 354

This contribution gathers the contents of the white paper submitted by the UV community to the Call issued by the European Space Agency in March 2013, for the definition of the L2 and L3 missions in the ... [more ▼]

This contribution gathers the contents of the white paper submitted by the UV community to the Call issued by the European Space Agency in March 2013, for the definition of the L2 and L3 missions in the ESA science program. We outlined the key science that a large UV facility would make possible and the instrumentation to be implemented. The growth of luminous structures and the building blocks of life in the Universe began as primordial gas was processed in stars and mixed at galactic scales. The mechanisms responsible for this development are not well-understood and have changed over the intervening 13 billion years. To follow the evolution of matter over cosmic time, it is necessary to study the strongest (resonance) transitions of the most abundant species in the Universe. Most of them are in the ultraviolet (UV; 950 Å-3000 Å) spectral range that is unobservable from the ground. A versatile space observatory with UV sensitivity a factor of 50-100 greater than existing facilities will revolutionize our understanding of the Universe. Habitable planets grow in protostellar discs under ultraviolet irradiation, a by-product of the star-disk interaction that drives the physical and chemical evolution of discs and young planetary systems. The electronic transitions of the most abundant molecules are pumped by this UV field, providing unique diagnostics of the planet-forming environment that cannot be accessed from the ground. Earth's atmosphere is in constant interaction with the interplanetary medium and the solar UV radiation field. A 50-100 times improvement in sensitivity would enable the observation of the key atmospheric ingredients of Earth-like exoplanets (carbon, oxygen, ozone), provide crucial input for models of biologically active worlds outside the solar system, and provide the phenomenological baseline to understand the Earth atmosphere in context. [less ▲]

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