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See detailRegistres de la langue en néo-égyptien: le cas des Tomb Robberies
Winand, Jean ULg

Conference (2014, December 05)

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See detailNanocomposites based on MWCNT and polystyrene, styrene-acrylonitrile copolymer, or polymethylmethacrylate, obtained by miniemulsion polymerization
Donescu, Dan; Corobea, Mihai Cosmin; Petcu, Cristian et al

in Journal of Applied Polymer Science (2014), 131(23), 411481-10

Free radical miniemulsion polymerization of styrene (St), St/acrylonitrile 3 : 1 mixture or methylmethacrylate in the presence of multiwalled carbon nanotubes (MWCNT) was proven as a convenient way to ... [more ▼]

Free radical miniemulsion polymerization of styrene (St), St/acrylonitrile 3 : 1 mixture or methylmethacrylate in the presence of multiwalled carbon nanotubes (MWCNT) was proven as a convenient way to obtain homogenous hybrids with perspectives in associated applications like foams specialties materials. Miniemulsion polymerization was viable up to 2% wt. MWCNT to monomer, without agglomerations. The grafting on MWCNT during the polymerization occurs without the need for supplementary functionalization and the polymer grafted nanotubes showed stable dispersions in the polymer solvent. Monomer polarity affected the grafting ability during the polymerization process. The nanocomposites obtained after purification and drying were used in foaming process. MWCNT presence in the related nanocomposites decreased the pore sizes in foam-like materials (for all three different matrices). At 1 wt % MWCNT content, low density (< 0.3 g/cm3), low pore size (< 10 μm) and high cell density (>109 cell/cm3) were achieved. [less ▲]

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See detailCan Electrical Resistivity Tomography offer us a dynamic view on what happens in the soil-plant continuum?
Garré, Sarah ULg

Conference (2014, December 05)

Root water and nutrient uptake and its relation to environmental factors is one of the least understood components in the terrestrial water balance and is of high importance for water resources management ... [more ▼]

Root water and nutrient uptake and its relation to environmental factors is one of the least understood components in the terrestrial water balance and is of high importance for water resources management, ecology and agriculture. As the processes in the soil-plant continuum are complex and inextricably intertwined, alternative, non-invasive measurement methods are necessary to unravel spatial and temporal dynamics of the system. Electrical resistivity tomography (ERT) has been proposed as a promising technique, since bulk resistivity maps and their temporal evolution may serve as a proxy for changes in soil moisture and pore water salinity, amongst others. However, the variables affecting the measured bulk electrical resistivity often change simultaneously in natural environments and not all influencing factors are yet well understood (e.g. influence of root biomass). Therefore, the method needs field-specific calibration. In addition to limitations due to signal-to-noise ratio and data inversion strategies, this implies that ERT still needs further development and research efforts for its use to characterize the soil-plant continuum. [less ▲]

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See detailEtude de la flore spontanée de la carrière de Loën pour de futures restaurations - Résultats
Pitz, Carline ULg; Mahy, Grégory ULg; Monty, Arnaud ULg et al

Conference given outside the academic context (2014)

Ce projet a pour objectif de caractériser la flore recolonisant spontanément les zones xériques non exploitées récemment de la carrière de Loën, du point de vue de la diversité spécifique et de la ... [more ▼]

Ce projet a pour objectif de caractériser la flore recolonisant spontanément les zones xériques non exploitées récemment de la carrière de Loën, du point de vue de la diversité spécifique et de la fonctionnalité écologique. Les communautés végétales ont été caractérisées au sein du site de Loën (diversité alpha) et d’un ensemble d’autres carrières représentatives de la diversité des contextes géographiques des carrières calcaires en Région Wallonne (diversité béta). L’étude a montré que, sur des laps de temps de plusieurs décennies, un processus de succession écologique s’est mis en place au sein du site de Loën, mais que cette succession ne tend pas vers une formation typique de pelouse sèche. Les explications peuvent être d’une part, que la disponibilité et l’apport de graines de pelouses sèches avoisinantes est insuffisant, et d’autre part, que le contexte abiotique pourrait être plus favorable à d’autres types de végétations herbacées. Cette étude illustre que des expériences de semis seraient souhaitable afin de définir les objectifs de restauration de la carrière de Loën et des carrières qui se trouvent dans des situations comparables. [less ▲]

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See detailMid-winter freeze experiment in the Arctic Ocean: Norwegian Young sea ICE cruise (N-ICE2015)
Nomura, Daiki; Granskog, Mats A.; Fransson, Agneta et al

Poster (2014, December 02)

In mid-January 2015, RV Lance will freeze into the ice north of Svalbard, Arctic Ocean at around 83.25°N 30°E, and passively drift with the ice as part of the Norwegian Young sea ICE cruise (N-ICE2015 ... [more ▼]

In mid-January 2015, RV Lance will freeze into the ice north of Svalbard, Arctic Ocean at around 83.25°N 30°E, and passively drift with the ice as part of the Norwegian Young sea ICE cruise (N-ICE2015). Judging from historic sea ice drift trajectories, it is likely that RV Lance will drift in a SW direction and the ship will probably be freed from the ice in mid spring after about two to three months of drift. Thereafter, RV Lance will return to her starting position and start a new drift. Under all circumstances, the ice drift project will end in late June 2015. Throughout the cruise the focus will be on the interaction of the atmosphere-ice-ocean system and the response of the marine ecosystem to the thinner ice regime. The overall goal of the project team is to improve our understanding of the role of the younger ice pack in the Arctic on greenhouse gas fluxes and to ultimately assess whether the Arctic Ocean is a sink or source of greenhouse gases. We plan to conduct long-term synchronous observations of Arctic snow and sea ice biogeochemistry and physics and fluxes of carbon dioxide, methane, nitrous oxide and bromoform. This work targets at filling a crucial gap in our understanding of the role of Arctic sea ice in the climate system. This is done by conducting state of the art observations on Arctic sea ice in the polar night, when observations are basically non-existent. Further we are focusing on the new thinner ice regime, which is even less documented. We aim to understand how the thinner sea ice in the Arctic basin contributes (i) to important greenhouse gas exchange between the atmosphere and ocean and (ii) to aerosol formation, that contribute to the radiative balance of the planet. This work will increase direct collaboration between Japanese and European scientists in the Arctic, and combines complimentary expertise and experience from several international partners to carry out the interdisciplinary work proposed. [less ▲]

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See detailPsychometrics and bibliometrics: Overview of future possible interactions
Magis, David ULg

Scientific conference (2014, December 02)

Bibliometrics is a growing research field with the main aim of collecting bibliometric information (citations, publications, awards...) to infer valuable rankings or to predict future academic performance ... [more ▼]

Bibliometrics is a growing research field with the main aim of collecting bibliometric information (citations, publications, awards...) to infer valuable rankings or to predict future academic performance. However, most bibliometric approaches are based either on pairwise comparisons of "objects" (authors, funding applications, academics...) with respect to selected "criteria" (publications, citation rate, h-index...), or on modeling observable academic outcomes using observed such criteria. The purpose of this talk is twofold. First, an improvement of the pairwise comparison approach will be outlined on the basis of so-called multicriteria decision aid (MCDA) routines, which will imply an increased flexibility and added freedom for the decision process. Second, we will start a deeper reflexion on possible connections between bibliometrics and psychometrics. Among others, the possibility of modeling latent "academic ability" as outcome of interest, given manifest criteria, will be put to an open discussion and exchange with the listeners [less ▲]

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See detailAlignment of quasar polarizations with large-scale structures
Hutsemekers, Damien ULg; Braibant, Lorraine ULg; Pelgrims, Vincent ULg et al

in Astronomy and Astrophysics (2014), 572

We have measured the optical linear polarization of quasars belonging to Gpc scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar ... [more ▼]

We have measured the optical linear polarization of quasars belonging to Gpc scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar polarization vectors are either parallel or perpendicular to the directions of the large-scale structures to which they belong. Statistical tests indicate that the probability that this effect can be attributed to randomly oriented polarization vectors is on the order of 1%. We also found that quasars with polarization perpendicular to the host structure preferentially have large emission line widths while objects with polarization parallel to the host structure preferentially have small emission line widths. Considering that quasar polarization is usually either parallel or perpendicular to the accretion disk axis depending on the inclination with respect to the line of sight, and that broader emission lines originate from quasars seen at higher inclinations, we conclude that quasar spin axes are likely parallel to their host large-scale structures. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 092.A-0221.Table 1 is available in electronic form at <A href="http://www.aanda.org/10.1051/0004-6361/201424631/olm">http://www.aanda.org</A> [less ▲]

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See detailAdolescent Risk Behaviours and Protective Factors Against Peer Influence
Cattelino, Elena; Glowacz, Fabienne ULg; Born, Michel ULg et al

in Journal of Adolescence (2014), 37(8), 1353-1362

This study examined the relationships between protective factors and involvement in risk behaviour of Italian adolescents with friends involved in risk. Protective factors were drawn from models of peers ... [more ▼]

This study examined the relationships between protective factors and involvement in risk behaviour of Italian adolescents with friends involved in risk. Protective factors were drawn from models of peers and from individual skills (perceived regulatory self-efficacy, intolerant attitudes about deviance) and orientation (to health, school, religion). The data are from two waves, 1 year apart, of a questionnaire survey of adolescents in northwestern Italy. Participants were 908 adolescents (42% boys) ages 14–16 years. Results of a hierarchical regression revealed that religiosity is a protective factor and that friends’ models for conventional behaviours and positive attitude about health can mitigate the influence of deviant friends on adolescent risk behaviour 1 year later, even after controlling for prior levels of risk behaviour. Possible implications of this study suggest the importance of implementing preventive interventions by involving the peer group, especially at about 16 years, and working with heterogeneous (deviant and nondeviant) groups. [less ▲]

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See detailThe sentence repetition task: A powerful diagnostic tool for French children with specific language impairment
Leclercq, Anne-Lise ULg; Quémart, Pauline; Magis, David ULg et al

in Research in Developmental Disabilities (2014), 35

This study assesses the diagnostic accuracy and construct validity of a sentence repetition task that is commonly used for the identification of French children with specific language impairment (SLI ... [more ▼]

This study assesses the diagnostic accuracy and construct validity of a sentence repetition task that is commonly used for the identification of French children with specific language impairment (SLI). Thirty-four school-aged children with a confirmed, diagnostically based diagnosis of SLI, and 34 control children matched on age and nonverbal abilities performed the sentence repetition task. Two general scoring measures took into account the verbatim repetition of the sentence and the number of words accurately repeated. Moreover, five other scoring measures were applied to their answers in order to separately take into account their respect of lexical items, functional items, syntax, verb morphology, and the general meaning of the sentence. Results show good to high levels of sensitivity and specificity at the three cut-off points for all scoring measures. A principal component analysis revealed two factors. Scoring measures for the respect of functional words, syntax and verb morphology provided the largest loadings to the first factor, while scoring measures for the respect of lexical words and general semantics provided the largest loadings to the second factor. Sentence repetition appears to be a valuable tool to identify SLI in French children, and the ability to repeat sentences correctly is supported by two factors: a morphosyntactic factor and a lexical factor. [less ▲]

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See detailToward a tool aimed to quantify soil compaction risks at a regional scale: application to Wallonia (Belgium)
D'Or, Dimitri; Destain, Marie-France ULg

in Soil & Tillage Research (2014), 144

The spatial analysis of the soil compaction risk has been developed at the regional level and applied to Wallonia (Belgium). The methodology is based on the estimation of the probability of exceeding the ... [more ▼]

The spatial analysis of the soil compaction risk has been developed at the regional level and applied to Wallonia (Belgium). The methodology is based on the estimation of the probability of exceeding the preconsolidation stress due to the application of loads on the soil. Preconsolidation stresses (Pc) are computed from the pedotransfer functions of Horn and Fleige (2003) at pF 1.8 and 2.5 and classified into 6 categories ranging from very low Pc (< 30 kPa) to extremely high Pc (> 150 kPa). The computation requires the knowledge of pedological (texture, organic content), mechanical (bulk density, cohesion, internal friction angle), and hydraulic variables (water content available, non-available water content, air capacity, saturated hydraulic conductivity). These variables are obtained from databases like HYPRES or AARDEWERK or from pedotransfer functions. The computation of Pc takes into account the spatial structure of the data: in some cases, data are abundant (e.g. texture data) and spatial variability is taken into account through geostatistical methods. In other cases, the data is sparse but uncertainty information can be extracted from the knowledge of the statistical distribution. Maps of the most probable Pc class are produced. Uncertainty is computed as the classification error probability. Implementation of these methods in Wallonia showed that Pc values higher than 120 kPa are reached either on 64 % of the territory at pF 2.5 or on 55 % at pF 1.8. A higher uncertainty was found at pF 2.5 than at pF 1.8. Uncertainty was also found higher for clay and clayed loess than for other textural classes present in Wallonia. The risk of compaction is defined as the probability that Pc is exceeded by the stress created by a load applied to the soil at a depth of 40 cm, the loads being similar to those induced by agricultural or forestry tires. It appeared that subsoil compaction risks exist mainly in loamy forest soils with small coarse fragments supporting loads similar to that existing on logging machines. In the zones where the uncertainty is low, the developed tool could be used as a basis for providing policy measures in order to promote soil-friendly farming and forest practices. [less ▲]

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See detailGrey-box identification of a non-linear solar array structure using cubic splines
Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg; Foltête, Emmanuel et al

in International Journal of Non-Linear Mechanics (2014), 67

Most identification methods in non-linear structural dynamics assume in advance a mathematical model of the non-linearities. This is however possible in specific situations only, since non-linear effects ... [more ▼]

Most identification methods in non-linear structural dynamics assume in advance a mathematical model of the non-linearities. This is however possible in specific situations only, since non-linear effects may be caused by numerous phenomena and a priori knowledge is generally limited. The present paper investigates the usefulness of piecewise third-order polynomials, termed cubic splines, to identify the complex non-linear dynamics of solar arrays in their stowed configuration. The estimation of the model parameters is achieved using the frequency-domain non-linear subspace identification (FNSI) method. A distinct advantage of the FNSI approach is its capability to calculate accurately a large number of parameters, while maintaining an acceptable computational burden. This makes tractable the use of cubic splines to represent non-linearity in real-life mechanical systems, as the dimensionality of the inverse problem is known to increase dramatically in this case. The experimental structure of interest consists of two parallel aluminium plates assembled with bolted connections. This application is challenging because of the existence of impacts between the two plates at high excitation amplitude, and of the activation of complicated stiffness and damping mechanisms within the bolted connections. [less ▲]

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See detailConclusion
Famerie, Etienne ULg

in La diplomatie romaine sous la République : réflexions sur une pratique (2014)

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See detailEvaluation of pairwise calibration techniques for range cameras and their ability to detect a misalignment
Lejeune, Antoine ULg; Grogna, David ULg; Van Droogenbroeck, Marc ULg et al

in International Conference on 3D Imaging (IC3D) (2014, December)

Many applications require the use of multiple cameras to cover a larger volume. In this paper, we evaluate several pair-wise calibration techniques dedicated to range cameras. We compare the precision of ... [more ▼]

Many applications require the use of multiple cameras to cover a larger volume. In this paper, we evaluate several pair-wise calibration techniques dedicated to range cameras. We compare the precision of a self-calibration technique based on the movement in front of the cameras to object based calibration. While the self-calibration method is less precise than its counterparts, it yields a first estimation of the transformation between the cameras and permits to detect when the cameras become mis-aligned. Therefore it is useful in a practical situations. [less ▲]

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See detailWood digestion in lower termites: multidisciplinary approaches based on differential feeding
Bauwens, Julien ULg; Brasseur, Catherine ULg; Tarayre, Cédric ULg et al

Poster (2014, December)

Termites digestive tract and hindgut especially still holds many secrets despites hundreds of years of research. The complexity of the symbiotic microbial community and the contrast of physio-chemical ... [more ▼]

Termites digestive tract and hindgut especially still holds many secrets despites hundreds of years of research. The complexity of the symbiotic microbial community and the contrast of physio-chemical environments found in lower termites paunch are potentially the key point to explain the efficiency of ligno-cellulose digestion. Contribution of advancing technologies accelerates the progress of our knowledge in this field. Here, we present multiple approaches combining old and recent techniques used to highlight the effect of ligno-cellulosic compounds on termite gut and the role of populations from the symbiotic microbial community. Termites Reticulitermes flavipes (Kollar) submitted to various artificial diets showed variations in flagellates populations profile and enzymatic activities. Differential protein expression was investigated using 2D-DIGE MALDI-TOF-TOF and 2D-LC-MS/MS using high resolution orbitrap analyzer. Results from both proteomic experiments tend to support each-other and bring complementary points of view. The gel-free analysis resulted in highly contrasted identification of enzymes involved in ligno-cellulose digestion and metabolism. Finally, differential feeding experiments leaded to in vivo selection of different symbiotic communities. These communities were characterized following some metabolism assays and allowed the cultivation of diverse microbial consortia using media closely related to the respective artificial diets. This work provides relevant data on termite and associated microbial community response to alimentary diets. [less ▲]

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See detailA finite-element reciprocity solution for EEG forward modeling with realistic individual head models
Ziegler, Erik ULg; Chellappa, Sarah Laxhmi ULg; Gaggioni, Giulia ULg et al

in NeuroImage (2014), 103

Highlights • Creates EEG forward models suitable for high-resolution source localization. • Automatic T1-based whole-head finite element meshing and leadfield computation. • Pipelines can incorporate ... [more ▼]

Highlights • Creates EEG forward models suitable for high-resolution source localization. • Automatic T1-based whole-head finite element meshing and leadfield computation. • Pipelines can incorporate conductivity tensors from diffusion-weighted images. • Open-source toolbox shared under a permissive software license. • Accuracy comparable to SimBio FEM and superior to OpenMEEG BEM solutions. [less ▲]

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