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See detailPluto's atmosphere from stellar occultations in 2012 and 2013
Dias-Oliveira, Alex; Sicardy, Bruno; Lellouch, Emmanuel et al

in Bulletin of the American Astronomical Society (2015, November 01), 47

We present results from two Pluto stellar occultations observed on 18 July 2012 and 04 May 2013, and monitored respectively from five and six sites in South America. Both campaigns involved large ... [more ▼]

We present results from two Pluto stellar occultations observed on 18 July 2012 and 04 May 2013, and monitored respectively from five and six sites in South America. Both campaigns involved large telescopes (including the 8.2-m VLT at ESO/Paranal). The high SNR ratios and multi-chord coverage provide amoung the best Pluto atmospheric profiles ever obtained from the ground.We show that a spherically symmetric, clear (no-haze) and pure N2 atmosphere with a unique temperature profile satisfactorily fits the twelve lightcurves provided by the two events. We find, however, a small but significant increase of pressure of 6% (6-sigma level) between the two dates, with values of 2.16 ± 0.2 and 2.30 ± 0.01 μbar at the reference radius 1275 km, respectively.We provide atmospheric constrains between 1190 km and 1450 km from Pluto's center, and we determine the temperature profile with accuracy of a few km in vertical scale. Our model shows a stratosphere with strong positive gradient between 1190 km (at 36 K, 11 μbar) and r =1215 km (6.0 μbar), where a temperature maximum of 110 K is reached. Above it is a mesosphere with negative thermal gradient of -0.2 K/km up to 1,390 km (0.25 μbar), at which point, the mesosphere connects itself to a more isothermal upper branch at 81 K. This profile provides (assuming no troposphere) a Pluto surface radius of 1190 ± 5 km, consistent with preliminary values obtained by New Horizons. Currently measured CO abundances are too low to explain the negative mesospheric thermal gradient. We explore the possibility of an HCN (recently detected by ALMA) cooling. This model, however, requires largely supersaturated HCN. Zonal winds and vertical compositional variations of the atmosphere are also unable to explain the observed mesospheric trend.These events are the last useful ground-based occultations recorded before the 29 June 2015 occultation observed from Australia and New Zealand, and before the NASA's New Horizons flyby of July 2015. This work can serve as a benchmark in the New Horizons context, enabling comparisons between ground-based and space results concerning Pluto's atmospheric structure and temporal evolution. [less ▲]

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See detailIncapacité de travail prolongée. Revue des facteurs de risque professionnels et des stratégies d'intervention
Somville, Pierre ULg; Mairiaux, Philippe ULg

in Archives des Maladies Professionnelles et de l'Environnement (2015), 76(5), 458-467

Purpose of the study In the context of the general population aging and the increasing cost of work disability, public authorities pay special attention to the employability of workers with health ... [more ▼]

Purpose of the study In the context of the general population aging and the increasing cost of work disability, public authorities pay special attention to the employability of workers with health problems. In order to consider strategies for reducing the duration of disability and promoting the return-to-work, the Belgian Federal Public Service Work and Employment wished to have an update of the available scientific evidence on this topic. Methods This literature review is based on articles published in English between 2001 and 2011 and extracted from the MEDLINE database. The review first part deals with long term incapacity risk factors while the second one describes evidence as regards prevention measures and intervention strategies. Results Some risk factors significantly associated with long term disability have been identified: being employed in heavy jobs, fear-avoidance reactions and psychosocial occupational factors such as job dissatisfaction, lack of work control, insufficient support, poor relationships with colleagues, but also the worker own perception of his ability to return to work. Early detection of these perceived barriers to return to work is needed. With regard to intervention strategies, the review, limited to low back pain associated work absences, supports the interest of ergonomic changes in the working environment and the importance of participative interventions. The communication between the return to work actors (i.e. clinical physicians, occupational physicians, employers, insurers and the worker himself) is a key factor in the success of the intervention. Finally, in heavier workload occupations, promoting a systematic access to a transitory light duty position appears to be an interesting guideline. [less ▲]

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See detailLa mise en scène du travail à distance: proposition d'une lecture goffmanienne
Franssen, Marine ULg; Rondeaux, Giseline ULg

Conference (2015, November)

Cette communication s’appuie sur les résultats issus d’une recherche menée dans une entreprise européenne du secteur des télécommunications, portant sur le travail à distance. Elle valorise en particulier ... [more ▼]

Cette communication s’appuie sur les résultats issus d’une recherche menée dans une entreprise européenne du secteur des télécommunications, portant sur le travail à distance. Elle valorise en particulier les apports des travaux de Goffman dans l’analyse de ce phénomène, tant sur le plan méthodologique que sur le plan de l’analyse. Dans le cadre de cette étude, l’équipe de recherche a élaboré une méthodologie d’observation multifocale, visant à cerner certains aspects du travail à distance généralement oblitérés par la littérature, essentiellement basée sur des pratiques déclaratives. Le recours à cette méthode d’observation permet ainsi de mettre en évidence des stratégies d’interaction mises en place par les acteurs à distance, choisissant de rendre visibles ou, a contrario, de maintenir cachées certaines attitudes lors d’interactions à distance. Par ailleurs, la mobilisation du concept de cadres de l’expérience, au coeur des travaux de Goffman, met également en évidence deux enjeux pour lesquels les différents cadrages d’une même situation influence la perception de dispositifs RH. Les résultats obtenus enrichissent l’appréhension des dispositifs de gestion du travail et du management à distance, en intégrant la compréhension et l’expérience qu’ont les acteurs des dispositifs ainsi que la manière dont ils se les approprient. [less ▲]

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See detailThe harmonic balance method for bifurcation analysis of large-scale nonlinear mechanical systems
Detroux, Thibaut ULg; Renson, Ludovic ULg; Masset, Luc ULg et al

in Computer Methods in Applied Mechanics and Engineering (2015), 296

The harmonic balance (HB) method is widely used in the literature for analyzing the periodic solutions of nonlinear mechanical systems. The objective of this paper is to exploit the method for bifurcation ... [more ▼]

The harmonic balance (HB) method is widely used in the literature for analyzing the periodic solutions of nonlinear mechanical systems. The objective of this paper is to exploit the method for bifurcation analysis, i.e., for the detection and tracking of bifurcations of nonlinear systems. To this end, an algorithm that combines the computation of the Floquet exponents with bordering techniques is developed. A new procedure for the tracking of Neimark–Sacker bifurcations that exploits the properties of eigenvalue derivatives is also proposed. The HB method is demonstrated using numerical experiments of a spacecraft structure that possesses a nonlinear vibration isolation device. [less ▲]

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See detailNumerical modelling of transient cyclic vertical loading of suction caissons in sand
Cerfontaine, Benjamin ULg; Collin, Frédéric ULg; Charlier, Robert ULg

in Geotechnique (2015), 65(12),

This paper presents numerical investigations of the monotonic and cyclic behaviours of suction caissons upon vertical transient loading. Both drained and partially drained conditions are investigated ... [more ▼]

This paper presents numerical investigations of the monotonic and cyclic behaviours of suction caissons upon vertical transient loading. Both drained and partially drained conditions are investigated. Monotonic compression and traction simulations are carried out to qualitatively compare results with the literature and validate the model. They highlight the different modes of reaction of the caisson to both compression and traction loading. A sensitivity analysis points out the strong influence of some parameters on the resistance of the caisson but also on the failure mechanism. The transient behaviour of the caisson upon different kinds of cyclic load signals is analysed. Results reproduce the settlement and pore water pressure accumulations observed during experiments. The influence of the key design parameters on the settlement accumulation is also assessed. Finally a cyclic diagram is proposed to describe the evolution of the final settlement upon different magnitudes of loading. [less ▲]

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See detailElmore D. L'intégrale Frémeaux et Ass.
Sacré, Robert ULg

E-print/Working paper (2015)

Compte rendu Coffret 5 CDs + livret . La Wallon et le Blues , un mariage réussi

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See detailAu-delà de l'exil: la critique cynique de Peter Sloterdijk
Hamers, Jérémy ULg

in Durand, Pascal; Sindaco, Sarah (Eds.) Le discours "néo-réactionnaire". (2015)

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See detailPourquoi dort-on?
BARREA, Christophe ULg

in 72ème Congrès du Gbpf: De Morphée au cauchemar (2015, November)

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See detailModernisation des institutions judiciaires belges: vers un management de type 2.0
Schoenaers, Frédéric ULg

in Cahiers de la Sécurité (2015), 32

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See detailCOMMENT EXPLORER LES SYMPTOMES NEGATIFS DE LA PSYCHOSE CHEZ L'ENFANT: UNE SEMIOLOGIE DIMENSIONNELLE
SCHOLL, Jean-Marc ULg

in Acta Psychiatrica Belgica (2015), 117

Despite its high frequency, psychotic syndrome in childhood is little understood and is often diagnosed only after several years of development, and this during a time when the child’s psychosocial future ... [more ▼]

Despite its high frequency, psychotic syndrome in childhood is little understood and is often diagnosed only after several years of development, and this during a time when the child’s psychosocial future is at stake. Negative symptoms are systematically present at the prodromal phase and are the most stable thereafter. It is therefore essential to furnish clinicians with precise semiological markers to recognize it. This paper presents a dimensional semiology of the negative symptoms for use in anamnesis and in clinical observation of the child. Is also gives a guide to the interviewing process. [less ▲]

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See detailHypervulnerability to Sound Exposure through Impaired Adaptive Proliferation of Peroxisomes.
Delmaghani, Sedigheh; Defourny, Jean; Aghaie, Asadollah et al

in Cell (2015), 163(4), 894-906

A deficiency in pejvakin, a protein of unknown function, causes a strikingly heterogeneous form of human deafness. Pejvakin-deficient (Pjvk(-/-)) mice also exhibit variable auditory phenotypes ... [more ▼]

A deficiency in pejvakin, a protein of unknown function, causes a strikingly heterogeneous form of human deafness. Pejvakin-deficient (Pjvk(-/-)) mice also exhibit variable auditory phenotypes. Correlation between their hearing thresholds and the number of pups per cage suggest a possible harmful effect of pup vocalizations. Direct sound or electrical stimulation show that the cochlear sensory hair cells and auditory pathway neurons of Pjvk(-/-) mice and patients are exceptionally vulnerable to sound. Subcellular analysis revealed that pejvakin is associated with peroxisomes and required for their oxidative-stress-induced proliferation. Pjvk(-/-) cochleas display features of marked oxidative stress and impaired antioxidant defenses, and peroxisomes in Pjvk(-/-) hair cells show structural abnormalities after the onset of hearing. Noise exposure rapidly upregulates Pjvk cochlear transcription in wild-type mice and triggers peroxisome proliferation in hair cells and primary auditory neurons. Our results reveal that the antioxidant activity of peroxisomes protects the auditory system against noise-induced damage. [less ▲]

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See detailOpportunités pour la valorisation des végétaux riches en anthocyanes comme sources de colorants alimentaires (synthèse bibliographique)
Beye, Cheikh ULg; Tounkara, Lat Souk; Seck, Mamadou Amadou et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2015), 19(4), 392-401

Introduction. Très répandues dans le règne végétal, les anthocyanes sont le sujet d’un grand nombre d’études qui abordent en général les aspects concernant leur instabilité vis-à-vis des conditions dans ... [more ▼]

Introduction. Très répandues dans le règne végétal, les anthocyanes sont le sujet d’un grand nombre d’études qui abordent en général les aspects concernant leur instabilité vis-à-vis des conditions dans lesquelles elles sont employées ou l’effet bénéfique de leur consommation sur la santé. Littérature. Ces aspects sont particulièrement importants lorsqu’on envisage de les extraire en vue de leur utilisation comme colorant alimentaire naturel. Dans cette revue bibliographique, les propriétés des anthocyanes susceptibles d’être altérées lors de leur transformation ont été étudiées. Par la suite, un état des lieux sur les méthodes de fabrication de colorants à base d’anthocyanes a été fait afin de dégager des perspectives pour l’exploitation des matières végétales qui en contiennent de grandes quantités. Conclusions. Les fruits et légumes utilisables pour la fabrication de colorants alimentaires sont nombreux et variés. Les différences au niveau du contenu ont une influence sur la stabilité de la couleur des extraits, mais les progrès récents en matière de formulation ouvrent des perspectives pour la valorisation des végétaux riches en anthocyanes. [less ▲]

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See detailSpecies diversity and abundance of aphids and their natural enemies in a crop association
Chevalier Mendes Lopes, Thomas ULg; Hatt, Séverin ULg; Starý, Petr et al

Poster (2015, November)

Crop associations can be efficient to reduce aphid populations, by disrupting the visual and olfactory location of host plants. However, increasing the chemical and structural complexity of vegetation can ... [more ▼]

Crop associations can be efficient to reduce aphid populations, by disrupting the visual and olfactory location of host plants. However, increasing the chemical and structural complexity of vegetation can also decrease the searching efficiency of predators and parasitoids, which are not always more abundant in complex habitats. Using attractive semiochemicals such as methyl salicylate (MeSA) combined with a crop association seems promising to maximise aphid control. We compared the abundances of aphids and their natural enemies between a wheat-pea mixture (with and without MeSA) and pure stands, using yellow traps and observations on plants. Significantly higher numbers of pea aphids (Acyrthosiphon pisum) were observed in the pure stand of pea compared with the mixture (with and without MeSA) in 2013 and 2014. Concerning aphid natural enemies, hoverfly larvae abundance was not significantly different between treatments in both years. Parasitoid mummies were significantly more abundant in the pure stand of pea compared with the mixture (with and without MeSA) in 2014. Fifty-two aphid species were collected in yellow traps, as well as 12 Aphidiinae and four Aphelinus species. Acyrthosiphon primulae, Aphelinus daucicola, Aphelinus fusciscapus, Aphidius asteris, Aphidius eadyi, Metopolophium frisicum, Praon barbatum, and Trioxys auctus were recorded for the first time in Belgium. Besides determining the effects of a wheat-pea mixture (with or without MeSA) on aphid control, this study contributed to increase the knowledge on aphid and their parasitoid diversity in Belgium, by recording new species and establishing the first Aphidiinae and Aphelinus national checklist. [less ▲]

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See detailActivity vs. Stability: a multi-proxy approach to reconstruct fluvial morphodynamics of Wadi Selloum in the vicinity of the rock shelter Ifri n’ammar (Morocco)
Bartz, Melanie; Rhixon, Gilles; El Ouahabi, Meriam ULg et al

Conference (2015, November)

The impact of environmental changes on the emergence and dispersal of anatomically modern humans (AMH) is particularly important in North Africa, since the Straits of Gibraltar might have served as ... [more ▼]

The impact of environmental changes on the emergence and dispersal of anatomically modern humans (AMH) is particularly important in North Africa, since the Straits of Gibraltar might have served as western migration route for AMH from Africa to Europe. The prehistoric rock shelter of Ifri n’Ammar in NE Morocco reveals discontinuous Middle and Late Palaeolithic occupation phases since ~170 ka. Our study focuses on Wadi Selloum deposits to unravel palaeoenvironmental features and geomorphological aspects of the direct vicinity of Ifri n’Ammar. As a tributary of the Moulouya River, the catchment area of this ephemeral stream amounts to ~290 km², spanning elevations between ~700 and 200 m above sea level. Headwaters of the 35 km long Wadi Selloum drain Mesozoic limestone and dolomite. The application of luminescence dating techniques on Wadi Selloum deposits yielded burial ages between 1.3 ± 0.2 ka and 78 ± 7 ka, covering morphodynamically stable and active phases. Overbank fines include well-developed soil horizons as evidence of stability and of more humid periods than today around 80 ka and during the Holocene. This is supported by pedofeatures discovered in thin sections as well as the composition of clay minerals of the wadi sediments. Disordered clay minerals and partly illite/chlorite mixed-layer characterize the soil levels. Levels relatively rich in chlorite, illite, ankerite and quartz are interpreted as corresponding to relatively dry periods, while more humid periods lead to more intensive weathering and consequently to the dominance of clay minerals more advanced in the relative stability scale, such as kaolinite. Smectite is taken to indicate a climate with contrasting seasons and a pronounced dry season. In contrast, coarse-grained deposits, which are partly characterised by calcrete layers, point to drier conditions after 80 ka and 14 ka. In addition, the lack of palaeosols confirms morphodynamic activity during these periods. Acknowledgement. This research is supported by the German Research Foundation (DFG) within the framework of the CRC 806 “Our Way to Europe” (http://www.sfb806.uni-koeln.de/). [less ▲]

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See detailThe genome of a tortoise herpesvirus (testudinid herpesvirus 3) has a novel structure and contains a large region that is not required for replication in vitro or virulence in vivo.
Gandar, Frederic ULg; Wilkie, Gavin S.; Gatherer, Derek et al

in Journal of Virology (2015), 89(22), 11438-11456

Testudinid herpesvirus 3 (TeHV-3) is the causative agent of a lethal disease affecting several tortoise species. The threat that this virus poses to endangered animals is focusing efforts on ... [more ▼]

Testudinid herpesvirus 3 (TeHV-3) is the causative agent of a lethal disease affecting several tortoise species. The threat that this virus poses to endangered animals is focusing efforts on characterizing its properties, in order to enable the development of prophylactic methods. We have sequenced the genomes of the two most studied TeHV-3 strains (1976 and 4295). TeHV-3 strain 1976 has a novel genome structure and is most closely related to a turtle herpesvirus, thus supporting its classification into genus Scutavirus, subfamily Alphaherpesvirinae, family Herpesviridae. The sequence of strain 1976 also revealed viral counterparts of cellular interleukin-10 and semaphorin, which have not been described previously in members of subfamily Alphaherpesvirinae. TeHV-3 strain 4295 is a mixture of three forms (m1, m2, and M), in which, in comparison to strain 1976, the genomes exhibit large, partially overlapping deletions of 12.5 to 22.4 kb. Viral subclones representing these forms were isolated by limiting dilution assays, and each replicated in cell culture comparably to strain 1976. With the goal of testing the potential of the three forms as attenuated vaccine candidates, strain 4295 was inoculated intranasally into Hermann's tortoises (Testudo hermanni). All inoculated subjects died, and PCR analyses demonstrated the ability of the m2 and M forms to spread and invade the brain. In contrast, the m1 form was detected in none of the organs tested, suggesting its potential as the basis of an attenuated vaccine candidate. Our findings represent a major step toward characterizing TeHV-3 and developing prophylactic methods against it. [less ▲]

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See detailRimbaud fétiche
Saint-Amand, Denis ULg

Conference (2015, November)

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See detailHistoires sur Able Archer
Kluge, Alexander; Leyh, Valérie ULg

in Cahiers d'Etudes Germaniques (2015), 69

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