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See detailOn the modelling of coupled hydro-mechanical behaviour of interfaces for offshore foundations
Cerfontaine, Benjamin ULiege; Collin, Frédéric ULiege

in Rasmussen, Amalie (Ed.) Marine Engineering: Emerging Developments and Global Challenges (2017)

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See detailEarly detection of university students with potential difficulties
Hoffait, Anne-Sophie ULiege; Schyns, Michael ULiege

Conference (2017, July)

Using data mining methods, this paper presents a new means of identifying freshmen's profiles likely to face major difficulties to complete their first academic year. We aim at early detection of ... [more ▼]

Using data mining methods, this paper presents a new means of identifying freshmen's profiles likely to face major difficulties to complete their first academic year. We aim at early detection of potential failure using student data available at registration, i.e. school records and environmental factors, with a view to timely and efficient remediation and/or study reorientation. We adapt three data mining methods, namely random forest, logistic regression and artificial neural network algorithms. We design algorithms to increase the accuracy of the prediction when some classes are of major interest. These algorithms are context independent and can be used in different fields. They rely on a dynamic split of the observations into subclasses during the training process, so as to maximize an accuracy criterion. Four classes are so built: high risk of failure, risk of failure, expected success or high probability of success. Real data pertaining to undergraduates at the University of Liège (Belgium), illustrates our methodology. With our approach, we are now able to identify with a high rate of confidence (90%) a subset of 12.2% of students facing a very high risk of failure, almost the quadruple of those identified with a non-dynamic approach. By testing some confidence levels, our approach makes it possible to rank the students by levels of risk and a sensitivity analysis allows us to find out why some students are likely to encounter difficulties. [less ▲]

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See detailGood practices in adapted physical activity for cancer patients and survivors: opinion of the Raviva program participants
Rompen, Jérôme ULiege; Scharff, Jules; Cloes, Marc ULiege

Conference (2017, July)

Introduction The Belgian Foundation against Cancer proposes an adapted physical activity (APA) program for cancer patients and survivors, called Raviva (http://www.cancer.be/raviva-bouger-pour-se-sentir ... [more ▼]

Introduction The Belgian Foundation against Cancer proposes an adapted physical activity (APA) program for cancer patients and survivors, called Raviva (http://www.cancer.be/raviva-bouger-pour-se-sentir-mieux).The activities are supervised by instructors with inconstant trainings and experiences. Contrary to other countries, Belgian APA instructors do not necessarily need to follow specific education programs such those proposed by the ACSM (Schmitz et al., 2010) or other organizations that propose exercise guidelines for cancer survivors. The aim of this study was to identify good practices in APA for cancer patients and survivors concerning activity characteristics and instructors behaviors, from the point of view of the Raviva program participants. Methods Firstly, an online questionnaire was submitted to Raviva participants; 72 of them filled it in. Secondly, 3 video-stimulated recall interviews were conducted after 3 different Raviva sessions (fitness, yoga and aqua-aerobics), each time with another participant. Results and discussion The sessions characteristics that participants like the most are related to the choice and quality of the proposed exercises (22% of responses) and to the perceived benefits of the activities (20%). The most appreciated qualities for an instructor are related to his/her human qualities (43%) and his/her expertise (32%). What participants like least about the sessions is a poor organization (27%) and what they like least about the instructors is linked to bad choices of exercises (18%). The video-stimulated recall interviews confirmed these data and provided more precision. Finally, we noticed that differences in responses were observed depending on the type of activity participants took part in. These findings could help instructors adapt their practices to their participants’ needs in order to promote adherence to physical activity among this population. References Schmitz, K. H., Courneya, K. S., Matthews, C., Demark-Wahnefried, W., Galvão, D. a, Pinto, B. M., … Schwartz, A. L. (2010). American College of Sports Medicine roundtable on exercise guidelines for cancer survivors. Medicine and Science in Sports and Exercise, 42(7), 1409‑26. https://doi.org/10.1249/MSS.0b013e3181e0c112 [less ▲]

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See detailImpact of endophytic entomopathogenic fungus on plant attractivity in aphid-virus-plant interactions
Fingu Mabola, Junior Corneille ULiege; Bosquée, Emilie ULiege; Boullis, Antoine ULiege et al

Poster (2017, July)

Endophytic entomopathogenic fungi (EEPF) are biological control agents able to live in their host plants in a symbiotic interaction and secrete secondary metabolites in the host plant tissues interacting ... [more ▼]

Endophytic entomopathogenic fungi (EEPF) are biological control agents able to live in their host plants in a symbiotic interaction and secrete secondary metabolites in the host plant tissues interacting with pests and phytopathogenic agents like plants virus. This is the case of Barley yellow dwarf virus (BYDV) transmitted by the Bird cherry oat aphid (Rhopalosiphum padi Linnaeus) and the Grain aphid (Sitobion avenae Fabricius). This virus is one of the most economically important phytoviruses affecting major world cereal crops such as wheat, rice and corn, causing significant yield losses. In this study, we investigated the influence of EEPF presence in the plant tissues on the vector’s orientation preference by considering the insect virus-infection status. We performed a choice test in Petri dishes and collection of volatile compounds emitted by plants. The impact of these interactions between plant-fungi-virus is finally discussed. [less ▲]

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See detailLanguage and analogical reasoning in children with Specific Language Impairment: The effect of articulatory suppression
Krzemien, Magali ULiege; Thibaut, Jean-Pierre; Stoffels, Valentine ULiege et al

Poster (2017, July)

Analogical reasoning shares a mutual influence with language development: analogical reasoning is improved by labelling analogical items with words describing the relations that they contain. Conversely ... [more ▼]

Analogical reasoning shares a mutual influence with language development: analogical reasoning is improved by labelling analogical items with words describing the relations that they contain. Conversely, structural alignment, a core mechanism of analogical reasoning, allows the acquisition of novel words and the development of grammar (Gentner, 2010). Given those findings, some authors have taken interest in the analogical reasoning ability of children with language disorders, and specifically of children with Specific Language Impairment (SLI). Those children have worse performance than their age-matched peers without language disorders in linguistic or non-linguistic analogical tasks (Leroy, Maillart, & Parisse, 2014). Our aim here is to see if this weakness is due to their language disorders and if they use the same verbal strategies as their peers to solve an analogical task. To experience these assumptions, we use a perceptual analogical task following an A:B::C:D paradigm: participants have to find the relation between two geometric forms A and B and to apply it to the C term in order to find the D term among distractors. The distractors either share perceptual features with the C term, what creates a competition that shall be inhibited, or not. Moreover, children are faced with three interfering task conditions: one without any interfering task, one with an articulatory suppression secondary task and one with a tapping secondary task, which is used in order to measure the general dual task demands. Comparing the results of these conditions will allow us to evaluate the impact of language and verbal strategies on analogical reasoning in control and SLI children. [less ▲]

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See detailThe Poetics of (In)visibility: A Stylistic Analysis of Caryl Phillips's Foreigners: Three English Lives
Tunca, Daria ULiege

in Ariel : A Review of International English Literature (2017), 48(3-4), 159-186

Caryl Phillips’s multi-voiced texts have often been studied through the lens of Bakhtinian polyphony. In this essay, I focus on the volume of fictionalized biographies Foreigners: Three English Lives ... [more ▼]

Caryl Phillips’s multi-voiced texts have often been studied through the lens of Bakhtinian polyphony. In this essay, I focus on the volume of fictionalized biographies Foreigners: Three English Lives (2007) to demonstrate that the polyphonic nature of Phillips’s work resides not only in the structural confrontation of characters’ and narrators’ voices but also in the inscription of the writer’s own subjectivity within these individual discourses. Borrowing methods from the discipline of stylistics, I first focus on the use of adjectives and modality in the opening section of Foreigners, “Dr. Johnson’s Watch,” to establish how the first-person narrator’s gradual transition from tentativeness to self-confidence constitutes a way for the implied author, on the one hand, to expose the thwarted logic of the colonially-tinted discourse of his eighteenth-century narrator and, on the other, to offer larger reflections on the process of ideological encoding inherent in the writing of historiography. Such an investigation based on modality furthers allow me to challenge the critical consensus according to which the second section of the book, “Made in Wales,” is a straightforward factual account. Indeed, I suggest that the story of the rise and fall of mixed-race boxer Randolph Turpin is in fact a highly polyphonic narrative featuring increasingly marked clashes in modality and point of view. These, I argue, may draw attention precisely to the problematic construction of historiographical discourse deceptively made to appear so commonsense by the narrator of “Dr. Johnson’s Watch.” [less ▲]

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See detailIs a new definition of intermodal transport interesting for transferring flows from road to more environmentally friendly modes?
Mostert, Martine ULiege; Limbourg, Sabine ULiege; Caris, An

Conference (2017, July)

Road remains the most used mode in Europe. Even if it is appreciated for its responsiveness, flexibility, and quickness, road transport is however responsible for negative impacts on its environment like ... [more ▼]

Road remains the most used mode in Europe. Even if it is appreciated for its responsiveness, flexibility, and quickness, road transport is however responsible for negative impacts on its environment like air pollution or climate change. Intermodal freight transport i.e. the transportation of goods using two or more modes of transport, in the same loading unit, without handling of the goods themselves is identified by the European Commission as an interesting solution for limiting the negative impacts of transport. In the classical conception of intermodal transport, pre- and post-haulage travels are supposed to be short, and to be performed by road transport, whereas the long-haul travel is done using rail or inland waterways (IWW). The objective of this study is to determine the impact on intermodal attractiveness of allowing other combinations of modes than the classical road-rail/IWW-road combination, during an intermodal travel. The goal is to determine the flow distribution of goods between direct transportation by road, rail or IWW, and any combination of these modes using intermodal transport. The novelty consists in taking into account three modes of transport in a mixed integer programming model, and to allow the transfer from any mode to any other at intermodal terminals where these modes coexist. For testing the hypothesis of intermodal transport attractiveness on medium to long distance, the model is applied to experimental data at the European level. [less ▲]

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See detailAn overview of the quality of interactions in Belgian pre-kindergarten classrooms
Leroy, Sandrine ULiege; Desmottes, Lise ULiege; Bergeron-Morin, Lisandre ULiege et al

Poster (2017, July)

Quality of teacher-children interactions during early childhood plays a protective effect on language development, more particularly with the more vulnerable children (Dickinson, 2011). However, the ... [more ▼]

Quality of teacher-children interactions during early childhood plays a protective effect on language development, more particularly with the more vulnerable children (Dickinson, 2011). However, the quality of these interactions, especially those supporting language development, is not always optimal (Piasta et al., 2012). It is of great concern in Belgium, where there is a need to prevent, during early childhood, an educational gap that too often depends on the socio-economic status of a child’s family (Vandenbroeck, 2015). Supporting the quality of teacher-children interactions in kindergarten may be a way to preventively support language development and educational achievement. But to date, little is known about what children experience in Belgium kindergarten, regarding language development support. The objective of this study is to document the quality of teacher-children interactions, in the second year of nursery school (4-5 years old) in the French-speaking part of Belgium. Observations take place in 23 classes. The CLASS Pre-K (Classroom Assessment Scoring System®, Pianta et al., 2008) is used for measuring the quality of teacher-children interactions. Trained observers have assessed quality of interactions along three domains: Emotional Support, Classroom Organization and Instructional support including language modeling. Results have revealed a lower quality in instructional support while showing a medium-high quality in the emotional support and classroom organization. However, scores in the instructional support increase when teachers propose activities deliberately dedicated to language. A more detailed analysis of the observations in 23 classes, in relation with number of children in the classroom and type of proposed activities will be discussed. These results will be interpreted within the particular context of kindergarten in Belgium. The present study aims at enabling a more global reflection on the modalities that can better support language development in an educational context, more particularly with more vulnerable children. [less ▲]

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See detailComparison of a dynamic model and experimental results of a residential heat pump with vapor injection and variable speed scroll compressor
Dechesne, Bertrand ULiege; Gendebien, Samuel ULiege; Lemort, Vincent ULiege et al

in PROCEEDINGS OF ECOS 2017 (2017, July)

The first part of this paper presents a Modelica-based dynamic model of the system. Finite-volume models are used for the heat exchangers and the evaporator model takes into account frost formation. A ... [more ▼]

The first part of this paper presents a Modelica-based dynamic model of the system. Finite-volume models are used for the heat exchangers and the evaporator model takes into account frost formation. A thermodynamic model of the vapor injection scroll compressor is developed using empirical correlations for the volumetric efficiency, isentropic efficiency and the ratio between the injection and suction mass flow rate. The second part presents experimental results of a vapor injection and variable speed scroll compressor air to water residential heat pump. The unit is a 10kW residential system working with R410a as working fluid and capable of providing floor heating and domestic hot water. It was tested in a controlled environment in order to achieve a wide range of outdoor, including frosting conditions, and indoor conditions. The model predictions and experimental results are compared in order to validate the component models in steady state. The experimental investigations showed that there is room for improvement on the control side of the system and the developed model can be used in order to develop model based control of the injection and outdoor electronic expansion valves. [less ▲]

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See detailLong-range dispersion forces between molecules subject to attosecond pulses from ab initio calculations
Verstraete, Matthieu ULiege

Scientific conference (2017, July)

The London-van der Waals dispersion forces arising from instantaneously induced dipoles in molecules are a key ingredient in a wide range of phenomena in physics, chemistry, and biology. Therefore, the ... [more ▼]

The London-van der Waals dispersion forces arising from instantaneously induced dipoles in molecules are a key ingredient in a wide range of phenomena in physics, chemistry, and biology. Therefore, the ability to control and manipulate dispersion forces between atoms and molecules is of great importance. Because those dispersion interactions depend crucially on the electronic properties of the molecular systems, a simple route to achieve this would consist in manipulating their electronic states. The recent development of ultra-short optical pulses has given researchers unprecedented control over the electronic degrees of freedom. These pulses, tailored in their frequency and envelope, allow the generation of a strongly out of equilibrium population of electronic states. We show how the Hamacker constants characterizing the London-van der Waals interaction between two molecules subject to an optical pulse can be calculated using time-dependent density functional theory (TD-DFT) or standard quantum chemistry methods and present several test cases of molecules subjected to IR and UV attosecond pulses. [less ▲]

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See detailTrajectory planning of soft link robots with improved intrinsic safety
Lismonde, Arthur ULiege; Sonneville, Valentin; Bruls, Olivier ULiege

in IFAC-PapersOnLine (2017, July)

For human-robot cooperation, intrinsic safety approaches aim at reducing the energy involved in the motion of the robotic system and at increasing the system compliance in order to reduce the risk of ... [more ▼]

For human-robot cooperation, intrinsic safety approaches aim at reducing the energy involved in the motion of the robotic system and at increasing the system compliance in order to reduce the risk of injury in case of an unexpected collision. Robots based on lightweight and inherently exible links exhibit attractive features in this context but the control of their motion then leads to a tremendous challenge. This paper presents a novel trajectory planning method for 3D robots which aims at improving the tracking accuracy despite the link exibility. [less ▲]

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See detailCrossoads ( juillet 2017) - chaque mercredi de 18h à20h - rediffusion: samedis de 22h à minuit
Sacré, Robert ULiege

Diverse speeche and writing (2017)

Programme radio hebdomadaire consacré aux musiques africaines-américaines ; streaming : www.equinoxefm.be ; podcasts www.mixcloud.com/robertsacre9

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See detailMonitoring of comets activity and composition with the TRAPPIST-North telescope
Moulane, Youssef ULiege; Benkhaldoun, Zouhair; Jehin, Emmanuel ULiege et al

in Journal of Physics: Conference Series (2017, July), 869

TRAPPIST-North (TRAnsiting Planets and PlanetesImals Small Telescope) is a 60-cm robotic telescope that was installed in May 2016 at the Oukaimeden Observatory. The project is led by the University of ... [more ▼]

TRAPPIST-North (TRAnsiting Planets and PlanetesImals Small Telescope) is a 60-cm robotic telescope that was installed in May 2016 at the Oukaimeden Observatory. The project is led by the University of Liège (Belgium) and the Caddi Ayad University of Marrakech (Morocco). This telescope is a twin of the TRAPPIST-South telescope, which was installed at the ESO La Silla Observatory in 2010. The TRAPPIST telescopes are dedicated to the detection and characterization of planets orbiting stars other than our Sun (exoplanets) and the study of comets and other small bodies in our solar system. For the comets research, these telescopes have very sensitive CCD cameras with complete sets of narrow band filters to measure the production rates of several gases (OH, NH, CN, C3 and C2) and the dust. With TRAPPIST-North we can also observe comets that would not be visible in the southern hemisphere. Therfore, with these two telescopes, we can now observe continuously the comets around their orbit. We project to study individually the evolution of the activity, chemical composition, dust properties, and coma morphology of several comets per year and of different origins (New comets and Jupiter Family comets) over a wide range of heliocentric distances, and on both sides of perihelion. We measure the production rates of each daughter molecules using a Haser model, in addition to the Afρ parameter to estimate the dust production in the coma. In this work, we present the first measurements of the production rates of comet C/2013 X1 (PANSTARRS) observed with TN in June 2016, and the measurements of comet C/2013 V5 (Oukaimeden) observed in 2014 with TRAPPIST-South. [less ▲]

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See detailBack to America: tracking the origin of European introduced populations of Quercus rubra L.
Merceron, Nastasia; Leroy, Thibault; Chancerel, Emilie et al

in Genome = Génome (2017), 60

Abstract: Quercus rubra has been introduced in Europe since the end of the 17th century. It is widely distributed today across this continent and considered invasive in some countries. Here, we ... [more ▼]

Abstract: Quercus rubra has been introduced in Europe since the end of the 17th century. It is widely distributed today across this continent and considered invasive in some countries. Here, we investigated the distribution of genetic diversity of both native and introduced populations with the aim of tracing the origin of introduced populations. A large sampling of 883 individuals from 73 native and 38 European locations were genotyped at 69 SNPs. In the natural range, we found a continuous geographic gradient of variation with a predominant latitudinal component. We explored the existence of ancestral populations by performing Bayesian clustering analysis and found support for two or three ancestral genetic clusters. Approximate Bayesian Computations analyses based on these two or three clusters support recent extensive secondary contacts between them, suggesting that present-day continuous genetic variation resulted from recent admixture. In the introduced range, one main genetic cluster was not recovered in Europe, suggesting that source populations were preferentially located in the northern part of the natural distribution. However, our results cannot refute the introduction of populations from the southern states that did not survive in Europe. [less ▲]

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See detailCompte-rendu de Rebeca Martín / Joaquim Parellada (eds.): Una horma para el cuento
Ceballos Viro, Alvaro ULiege

in Iberoamericana (2017), 65

Detailed reference viewed: 27 (0 ULiège)
See detailCan we use semiochemicals to control Aphis craccivoraKoch?
Bayendi-Loudit, Sandrine ULiege; Yarou, Boni Barthélémy ULiege; Boullis, Antoine ULiege et al

Poster (2017, July)

Amaranthus hybridus L. (Amaranthaceae) is among the most important vegetable crop in several sub-Saharan countries. Aphis craccivora Koch (Homoptera: Aphididae) is an aphid species that cause significant ... [more ▼]

Amaranthus hybridus L. (Amaranthaceae) is among the most important vegetable crop in several sub-Saharan countries. Aphis craccivora Koch (Homoptera: Aphididae) is an aphid species that cause significant losses in absence of chemical control. In this laboratory research, we evaluate the efficiency of informative substances (E-b-farnesene, methyl salicylate, essential oil of Ocimum gratissimum L. and Ocimum basilicum L.) to repel aphids from their host plant. Our assays were carried out in plastic trays containing twenty-five amaranth plants. In each tray, twenty apterous A. craccivora adults were placed on the central plant (release plant) associated with a semiochemical releaser containing 100 µl of the substance to be tested diluted in paraffin oil. The number of aphids was then counted on each plant surrounding plants every three-days for twelve days. We observed a significant repulsive effect of O. gratissimum and O. basilicum essential oils, that considerably reduced the aphid population on the treated plant, compared to control. However, no repulsive effect of E-b-farnesene and methyl salicylate on aphids was observed. Bioactivities of these substances and their using as alternative aphicidal in integrated pest management are discussed [less ▲]

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See detailMigraine triggers and habituation of visual evoked potentials
Lisicki Martinez, Marco ULiege; Ruiz-Romagnoli, Emiliano; Piedrabuena, Raul et al

in Cephalalgia : An International Journal of Headache (2017)

Background: Identifying specific subsets of patients within the clinical spectrum of migraine could help in personalizing migraine treatment. Profiling patients by combining clinical characteristics and ... [more ▼]

Background: Identifying specific subsets of patients within the clinical spectrum of migraine could help in personalizing migraine treatment. Profiling patients by combining clinical characteristics and neurophysiological biomarkers is largely unexplored. We studied the association between migraine attack triggers and habituation of visual evoked potentials. Methods: We personally interviewed 25 patients about their migraine triggers following a structured list, and measured the N1-P1 habituation slope over six blocks of 100 averaged pattern-reversal VEP afterwards. Results: The mean number of triggers per patient was 4.52 1.42. Habituation slopes differed significantly between subjects who reported stress as a migraine trigger (deficient VEP habituation) and subjects who did not (preserved VEP habituation). For the remaining categories, the mean amplitude slope was always positive, indicating deficient habituation, and was not significantly different between subgroups. Conclusions: Migraine patients not reporting perceived stress as a trigger for their attacks might constitute a distinct clinic-physiological subset within the migraine spectrum. [less ▲]

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