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See detailInvestigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Lagadic, Laurent; Barsi, Alpar et al

in Science of the Total Environment (2014), 493

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active ... [more ▼]

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to μg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 μg/L and 17.6 μg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests. [less ▲]

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See detailInteractions discursives et graphiques en conception architecturale à distance
Joachim, Guillaume ULg

in Leclercq, Pierre (Ed.) Communication multimodale et collaboration instrumentée. Regards croisés sur Énonciations, Représentations, Modalités (2014, September 15)

Cet article présente une analyse qualitative de la conception architecturale à distance outillée par un dispositif de communication multimodale synchrone. À partir d’une transcription et d’un codage de ... [more ▼]

Cet article présente une analyse qualitative de la conception architecturale à distance outillée par un dispositif de communication multimodale synchrone. À partir d’une transcription et d’un codage de vidéos d’architectes qui collaborent en dessinant et discourant simultanément, nous étudions comment ces professionnels utilisent différentes ressources graphiques et verbales pour élaborer collectivement des connaissances. [less ▲]

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See detailRandom forests with random projections of the output space for high dimensional multi-label classification
Joly, Arnaud ULg; Geurts, Pierre ULg; Wehenkel, Louis ULg

in Machine Learning and Knowledge Discovery in Databases (2014, September 15)

We adapt the idea of random projections applied to the out- put space, so as to enhance tree-based ensemble methods in the context of multi-label classification. We show how learning time complexity can ... [more ▼]

We adapt the idea of random projections applied to the out- put space, so as to enhance tree-based ensemble methods in the context of multi-label classification. We show how learning time complexity can be reduced without affecting computational complexity and accuracy of predictions. We also show that random output space projections may be used in order to reach different bias-variance tradeoffs, over a broad panel of benchmark problems, and that this may lead to improved accuracy while reducing significantly the computational burden of the learning stage. [less ▲]

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See detailLes Mooc : étude énonciative d’une pédagogie multimodale
Dondero, Maria Giulia ULg; Eléni, Mouratidou

in Leclercq, Pierre (Ed.) Communication multimodale et collaboration instrumentée. Regards croisés sur Énonciations, Représentations, Modalités (2014, September 15)

Cette contribution interroge les pratiques de pédagogie multimodale instrumentée des Massive Open Online Courses au travers d’une étude énonciative. Partant du principe que la communication multimodale ... [more ▼]

Cette contribution interroge les pratiques de pédagogie multimodale instrumentée des Massive Open Online Courses au travers d’une étude énonciative. Partant du principe que la communication multimodale instrumentée utilise différentes médiations sémiotiques (vidéo, peinture, dessin à la main, graphique, schéma, sonorité, musique etc.) nous nous proposons d’observer et d’analyser ces types de modalités communicationnelles telles que mises en place par les mooc. Ce, dans l’objectif de saisir la variété des pratiques multimodales auxquelles recourent les Massive Open Online Courses. Nous tentons également de souligner ce qui définit la spécificité de ces pratiques et la manière dont l’étude sémiotique des stratégies énonciatives peut-elle contribuer aux questionnements actuels en sciences de la communication. Nous répondons à ces questions à travers l’analyse de deux mooc issus de deux plateformes différentes : The Future of Storytelling de la plateforme Iversity et Scientific Humanities de la plateforme France Université Numérique. [less ▲]

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See detailAppropriation et gestion d’une activité collaborative distante. Le cas d’un atelier pédagogique de la conception architecturale
Dondero, Maria Giulia ULg; Shirkhodaei, Shima ULg

in Leclercq, Pierre (Ed.) Communication multimodale et collaboration instrumentée. Regards croisés sur Énonciations, Représentations, Modalités (2014, September 15)

Cette étude porte sur l’utilisation du dispositif SDC (Studio Digital Collaboratif) dans un projet collaboratif pédagogique de conception architecturale. Dans une perspective sémiotique, nous étudions le ... [more ▼]

Cette étude porte sur l’utilisation du dispositif SDC (Studio Digital Collaboratif) dans un projet collaboratif pédagogique de conception architecturale. Dans une perspective sémiotique, nous étudions le fonctionnement de la communication médiatisée dans les ateliers de formation par projet. Dans ces ateliers, les encadrants suivent l’avancement du projet de la conception architecturale des étudiants à travers les séances hebdomadaires de correction des documents. Ainsi, nous nous focalisons sur le rôle de l’opérateur — ici une des équipes collaboratrices — en adoptant le point de vue de la sémiotique des pratiques (J. Fontanille, Pratiques sémiotiques, Paris, PUF, 2008). Une perturbation dans l’activité collaborative des étudiants pendant l’atelier est au centre de notre propos et nous permettra de problématiser la question de l’appropriation, de la désappropriation et de la réappropriation de la pratique distante et simultanée. Cette perturbation nous permettra également de valoriser le rôle de l’opérateur dans la gestion d’une activité collaborative outillée en cours d’accomplissement. [less ▲]

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See detailIntegrated modelling and uncertainty analysis for assessment of climate change effects on groundwater resource
Goderniaux, Pascal; Wildemeersch, Samuel ULg; Dassargues, Alain ULg

Conference (2014, September 15)

Climate change will bring new pressure on surface and groundwater resources (e.g. Allen et al., 2004; Goderniaux et al., 2009; Van Roosmalen et al., 2009) in many parts of the world. Additional work is ... [more ▼]

Climate change will bring new pressure on surface and groundwater resources (e.g. Allen et al., 2004; Goderniaux et al., 2009; Van Roosmalen et al., 2009) in many parts of the world. Additional work is required to help water managers to plan for future changes. For example, most of studies provide projections for a stationary climate representative of the end of the century, although information is demanded for the near-future. A sophisticated transient weather generator (WG) in combination with an integrated surface-subsurface hydrological model (HydroGeoSphere) are used for producing a stochastic generation of large numbers of equiprobable climatic time series, representing transient climate change, and assess impacts on groundwater resources in a probabilistic way. This new methodology is applied for the unconfined chalky aquifer of Hesbaye (Geer basin in Belgium). The following uncertainty sources are studied : (1) the uncertainty linked to the calibration of the hydrological model, using 'UCODE_2005' (Poeter et al., 2005); (2) the uncertainty linked to the global and regional climatic models (GCMs and RCMs), by using a multi-model ensemble; (3) the uncertainty linked to the natural variability of the weather, by using stochastic climate change scenarios. 30 equiprobable climate change scenarios from 2010 to 2085 have been generated for each of 6 different RCMs. Results show that although the 95% confidence intervals calculated around projected groundwater levels remain large, the climate change signal becomes stronger than that of natural climate variability by 2085. Additionally, the WG ability to simulate transient climate change enabled the assessment of the likely timescale and associated uncertainty of a specific impact. This methodology constitutes a real improvement in the field of groundwater projections under climate change conditions as it enables water managers to analyse risks and take decisions with full knowledge of projected impact and their degree of confidence. [less ▲]

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See detailSleep homeostasis and the circadian timing system set the dynamics and excitability of neuronal ensembles
Vandewalle, Gilles ULg

in Journal of Sleep Research (2014, September 14), Suppl

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See detailPsychological processes mediating the link between depression severity and the level of behavioural activation: Assessment of a conceputal model
Wagener, Aurélie ULg; Baeyens, Céline; Blairy, Sylvie ULg

Poster (2014, September 12)

INTRODUCTION. Depression is a common psychopathology characterized by a decrease of the level of behavioural activation (BA) that is the level of engagement in activities. The relationship between ... [more ▼]

INTRODUCTION. Depression is a common psychopathology characterized by a decrease of the level of behavioural activation (BA) that is the level of engagement in activities. The relationship between depression and BA is well-established in the scientific literature. According to theoretical models of depression, psychopathology is also characterized by biases in five sets of psychological processes (PP): self-image (e.g. self-esteem), negative repetitive thoughts (e.g. ruminative thoughts), experiential avoidance (e.g. mindfulness), environmental satisfaction (e.g. environmental reward observation) and emotional regulation (e.g. distress tolerance). Therefore, the present study aims to identify PP mediating the relationship between depression and the level of BA. In order to reach this objective, a conceptual model is tested. METHOD. 361 adults (x ̅ age=36, σ=15), from clinical and non-clinical settings, fulfilled a series of questionnaires assessing several variables: sociodemographic data, depression, anxiety, level of BA and the above-cited five sets of PP. Covariance structure analysis will be conducted in order to test the conceptual model mentioned above. RESULTS. Some preliminary results are presented. As expected, a negative significant correlation between depression and BA (r=-.66, p<.01) have been highlighted. Negative significant correlation appeared between BA and the measured PP: self-esteem (r=-.27, p<.01), ruminative thinking (r=-.53, p<.01), environmental reward observation (=-.13, p<.05). Positive significant correlations appeared between BA and mindfulness (r=.49, p<.01) and distress tolerance (r=.26, p<.01). DISCUSSION. The preliminary results are in line with our hypotheses. Indeed, the level of BA is negatively linked to PP usually biased in depression such as self-esteem. The mediating role of these PP between depression and the level of BA will be discussed. [less ▲]

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See detailJupiter’s magnetopause: A search for wave and reconnection signatures
Bonfond, Bertrand ULg; Kivelson, M. G.; Khurana, K. K. et al

Conference (2014, September 12)

Surface waves and magnetic reconnection are two key processes taking place at the planetary magnetopause. They allow the coupling, through energy (and particle) transfer, of the interplanetary medium and ... [more ▼]

Surface waves and magnetic reconnection are two key processes taking place at the planetary magnetopause. They allow the coupling, through energy (and particle) transfer, of the interplanetary medium and the magnetosphere. The relative importance of large scale Dungey reconnection and viscous interaction (including small-scale intermittent reconnection associated with Kelvin-Helmholtz vortices) are expected to be different at Jupiter compared to the Earth’s case. Such differences would be due to the combination of a) a weaker solar wind pressure and Alfvén velocity as the distance to the Sun increases, b) a high-β plasma sheet, originating from Io’s outgassing, which inflates the Jovian magnetosphere, c) the rapid rotation of the planet relative to its size (e.g. Desroche et al. 2012). Here we analyse the signatures of wave activity and reconnection on the magnetopause of Jupiter, based on magnetic field and energetic particle measurements from the successive spacecraft that explored the Jovian system. Up to now, 7 spacecraft equipped with a magnetometer have crossed the Jovian magnetopause: Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, Ulysses, Galileo and Cassini. We make use of several normal direction finding techniques, such as the Minimum Variance Analysis, in order to identify waves and Kelvin-Helmholtz vortices. As far as the reconnection is concerned, small scale signatures of flux-tube events (FTEs) had been identified by Walker and Russell (1985), based on a limited data-set from the Pioneers’ and Voyagers’ fly-bys. Here we will extend this search to the extensive dataset from all the missions that explored Jupiter’s system. [less ▲]

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See detailValorisation de l’information pédologique numérisée pour la modélisation de la percolation des pesticides vers les eaux souterraines
Bah, Boubacar Billo ULg

Doctoral thesis (2014)

In Wallonia (southern Belgium), 81% of human drinking water is captured from groundwater tables. In spite of actions implemented under the European directives and thematic strategies, the required ... [more ▼]

In Wallonia (southern Belgium), 81% of human drinking water is captured from groundwater tables. In spite of actions implemented under the European directives and thematic strategies, the required standard (0.1 µg L-1 by pesticide and 0.5 µg L-1 for all pesticides) for human drinking water is most often exceeded at some catchments. Tools such as mechanistic models are appropriate since they allow an a priori estimation of pesticide concentrations leached at the bottom of soil profile, which could reach the groundwater tables. However, simulations often lead to a degree of uncertainty due to the approximations noted in the models, or due to the reliability of available data. The main objective of this thesis was to improve the usefulness of the Digital Soil Map of Wallonia (DSMW) and the associated soil analysis database named “Aardewerk” in the framework of the evaluation of the groundwater table contamination by pesticides, in order to reduce approximations associated with the GeoPEARL model and its meta-model MetaPEARL in the area of Condroz. In order to cover the broad spectrum of pesticides used in agriculture in Wallonia, nine theoretical pesticides have been defined. The first research question is to measure the sensitivity of GeoPEARL to two soil data parameterization schemes at the regional scale, depending on whether we first aggregate soil data at a regional scale before application of the model (AC approach); or we first apply the model to soil profiles and aggregate simulated leached concentrations afterwards (CA approach). The results show a significant difference between the two approaches, compared on the basis of a spatial threshold (80th percentile) calculated by soil type. Moreover, this difference varies depending on pesticide type, and is more important when the simulated concentrations are very low. It is also clear from this analysis that only pesticides located in certain ranges of DT50 (30 and 67 days) and Kom (58 and 252 dm3 kg-1) give concentrations more often above water potability standard of 0.1 µg L-1. The second research question is to calibrate MetaPEARL metamodel (simplified model) based on GeoPEARL simulated concentrations, from which it was derived by considering only the most sensitive parameters of GeoPEARL. The objective by developing a metamodel is to provide a simple tool, usable for a first evaluation of pesticides leaching in order to identify the most risk-prone areas, but also readily transposable for a global decision support system. In contrast to the approach of MetaPEARL calibration used until now, taking into account soil morphology through soil horizons (layers) types explains about 80% of the spatial variability of pesticide concentrations obtained from the complete original GeoPEARL model. The third research question is to take into account the spatial variability of input variables within the same soil typological unit using stochastic simulations to assess the uncertainty associated with deterministic simulations (taking into account average values by soil type for the input variables at the regional scale) obtained from MetaPEARL. The random spread of soil characteristics variability leads to a very significant spreading of simulated pesticide concentrations. Moreover, we obtain values of 80th spatial probabilistic percentile higher than those obtained from the deterministic approach. Consequently, for a risk mapping designed to aid decision-making tools, the probabilistic approach should be used since it allows, by taking into account the spatial variability of the model input parameters, to obtain more realistic concentrations of leached pesticides. [less ▲]

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See detailRebuilding the educational system in post-conflict context in Kosovo - Survival of the Unmik’s provisions to support the living together through primary education
Pierre, Alexia ULg

Poster (2014, September 12)

In the aftermaths of the Cold War, the International Community adopts the objective of Education for All. Indeed, Education appears as a tool of social and economical development worldwide and supports ... [more ▼]

In the aftermaths of the Cold War, the International Community adopts the objective of Education for All. Indeed, Education appears as a tool of social and economical development worldwide and supports global development. Education allows individuals to take part effectively and actively in the collective life of the society they belong to. Soon after the adoption of this objective, the war is identified as the major obstacle in the fulfillment of this objective of Education for All. The international stakeholders takes their stand in favor of the continuation of the schooling during protracted crisis and wars, what lead to the education in emergency. This education has to spread values, behaviors and attitudes that attack the roots of the conflict. An objective of peace building and conflict prevention is since added to education. In a same temporality, the Kosovo Albanians were submitted to a segregationist policy headed by the Government of Milosevic, the Republika Srpska. This Government aims to make the Kosovo an unmixed territory, inhabited only by Serbs. Kosovo Albanians are rejected from all the state positions and state-owned entreprises. Education appears as a convergent point of the communities antagonisms and a critical issue between Serbs and Albanians in Kosovo. The freedom of being educated in their mother tongue is denied to the Kosovo Albanians through the policy of the Republika Srpska. The Kosovo Albanians react in setting up a parallel education system, in which virtually all the Albanian children intend school from 1992 to 1998. This parallel education system can be seen as a strong element of the pacific resistance of the Kosovo Albanians and a factor of social strength. This parallel educational system collapsed in 1998 due to the war situation in Kosovo. During this internal armed conflict, violations of the Law of war and of the International humanitarian Law are so huge that Nato intervenes through a military air campaign. This military intervention is immediately followed by a civil administration mission, the Unmik, whose mandate is to normalize the life of the inhabitants of Kosovo. Unmik is a restorative model not dedicated to the war victims. The restorative aspects for victims can be seen in the reinstallation of the Kosovo Albanians as full-right citizens. When arriving in Kosovo, Unmik faces two systems of education. Unmik’s first objective is to rebuild a unified education system in Kosovo. Along with objectives of democratization and modernization of a system inherited from a communist model. This intervention is an opportunity to promote and support peace education and conflict prevention through education, in echo with the latest international provisions on education. To achieve this objective of peace building and conflict prevention through education, the pedagogical methods, the contents of teaching and the structure of the education system has to be reformed and restructured. My work aims to explore the reconstruction process of the education system in Kosovo and the operationalization of the provisions that turn education as a tool of peace and conflict prevention, in the primaries schools of Prishtina. My approach is qualitative, inspired by the systemic perspective. The aim of this research is not to evaluate the results of the new Kosovo education system. This work is designed to explore the process of this post-war reconstruction, and to understand how international provisions come within this process and are effectively implemented in the primaries schools. The research question is on the present survival and effectiveness of these provisions in the primaries schools of Prishtina. This work was done first by a confrontation between a corpus of international normative texts on education and a legislative and normative corpus of local texts on education. This first step was dedicated to the selection of the special provisions relative to education as a tool of peace building. It appears that Civic Education and History are the two main teachings in the broadcasting of elements that helps to create a social cohesion. The tools for the data collection were based on the elements selected through this bibliographical research, as the analysis table of the empirical datas. Standardized questionnaires has been completed by teachers in History and Civic Education, and by Directors of the primaries school of Prishtina. Interviews with Kosovo people who were involved in the rebuilding process of the education system were carried out. The results highlights that International Community massively imposed this new model of education, what is visible through the identical profiles of all the schools that participated to the research. It appears that such an intervention is limited by the specificities and the reality of the Kosovo, which were not taken into consideration enough to make this new education system fit well to the very specific aspects of Kosovo. The question of the adaptability of such a model, created out of the Kosovo and without sufficient rely on the local population, is raised through this study. Indeed, the actual education system in Prishtina faces huge challenges in terms of equipment, funding and space. These challenges were not met by the Unmik’s work and are still existing, when the legislative and normative frame is continually developed in respect of the international developments in the matter. Indeed, fundamental education has to be a way to get competencies leading to a democratic citizenship, instead of a way to acquire only school basic knowledge. The potential in peace building and conflict prevention of the present education system in Kosovo is not able to be fully developed. If all the international provisions are well translated into the local provisions and operationalized in the primaries schools, the system has reached its limits and is not able to overcome its numerous challenges. Moreover, there is still two independent systems of education in Kosovo, and the education dedicated to the peace building and conflict prevention reaches only children intended schools of the official system. Serbs children are still educated in the same perspective than during the war. In a long terme perspective, the Kosovo education system will not be able to produce the expected outcomes. This contains risks of resurgence of the conflict. [less ▲]

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See detailBiologie de la reproduction et analyse du déterminisme et de la différenciation du sexe à des stades précoces chez le tilapia du Nil, Oreochromis niloticus
Gennotte, Vincent ULg

Doctoral thesis (2014)

La reproduction des poissons téléostéens se caractérise par une diversité des types de sexualité (gonochorisme vs hermaphrodisme) et des systèmes de déterminisme du sexe (génétique et/ou environnemental ... [more ▼]

La reproduction des poissons téléostéens se caractérise par une diversité des types de sexualité (gonochorisme vs hermaphrodisme) et des systèmes de déterminisme du sexe (génétique et/ou environnemental), ainsi que par une plasticité du contrôle génétique et endocrinien de la différenciation sexuelle incomparables parmi les autres vertébrés. Le tilapia du Nil (Oreochromis niloticus) est un cichlidé gonochorique possédant un système chromosomique de déterminisme sexuel à homogamétie femelle XX/XY, complété par un déterminisme environnemental, les hautes températures pouvant modifier le développement phénotypique du sexe. L’intérêt porté à cette espèce en aquaculture à conduit au développement de différentes techniques de contrôle du sexe (par traitement hormonal) permettant la production de poissons présentant différentes combinaisons de phénotype/génotype sexuels (mâles XX, XY, YY, femelles XX, XY et YY). Ces derniers constituent des outils majeurs de l’étude du déterminisme et de la différenciation du sexe et soulèvent de nombreuses questions concernant les interactions génotype/phénotype sexuels chez cette espèce. Au regard de ces considérations, nous nous sommes fixés 2 objectifs principaux : 1. Déterminer l’influence du génotype sexuel sur certains aspects liés à la biologie reproductive chez le tilapia du Nil tels que la qualité du sperme, les taux de stéroïdes sexuels (testostérone, T ; 17β-œstradiol, E2 ; 11-cétotestostérone, 11KT) et les comportements agressifs. Le génotype sexuel ne semble pas avoir d’influence sur la qualité gamétique des mâles, puisqu’aucune différence n’est observée entre les individus XX, XY et YY, alors que paradoxalement, les taux de 11KT sont plus élevés chez les mâles XX. De la même manière, les femelles présentent des taux croissants d’E2 chez les individus XX, XY et YY. Ces différences de taux de stéroïdes sexuels pourraient être liées aux taux d’agressivité (évalué par la quantification de huit comportements agonistiques dans des confrontations mâle-femelle) plus élevés des mâles XX et des femelles XY et YY et engendrer des perturbations des comportements reproducteurs. Des recherches complémentaires sont nécessaires d’une part, pour évaluer l’effet du génotype sur la qualité des gamètes des femelles et d’autre part, pour déterminer si les modifications phénotypiques observées sont liées à l’expression du génotype sexuel ou à des perturbations engendrées par les traitements hormonaux d’inversion sexuelle administrés durant la période de différenciation des gonades. 2. Explorer les mécanismes du déterminisme et de la différenciation à des stades précoces du développement. Grâce à la mise au point d’une technique d’inversion sexuelle ciblant les périodes embryonnaire et larvaire (avant 10 jpf) par des expositions courtes (4h) d’embryons âgés d’un jpf à des androgènes (11KT, 17α-méthyltestostérone), un inhibiteur de l’aromatase (Fadrozole) ou un œstrogène (17α-éthynylœstradiol), nous avons confirmé l’existence d’une période sensible de la différenciation sexuelle avant le développement des gonades. Les voies de différenciation phénotypique semblent être différentes en fonction du génotype, puisque la masculinisation des embryons XX est moins efficace (max 10%) que la féminisation d’embryons XY (max 91%). De la même manière, un probable effet chromosomique rend inefficace la féminisation d’embryons YY. La féminisation des individus XY est concomitante avec une augmentation des taux de T et d’E2 et d’expression de l’aromatase cérébrale à 4 jpf qui pourrait indiquer un rôle précoce du cerveau dans la différenciation sexuelle. Dans l’ensemble, nos résultats nous permettent de suggérer, d’une part, que les premiers événements moléculaires de la différenciation sexuelle du tilapia sont initiés avant la formation des gonades, et d’autre part, que chez les individus sexuellement inversés, des différences sexuelles peuvent apparaître dans le cerveau avant ou en même temps que le développement des gonades et induire des modifications comportementales à l’âge adulte. La question du rôle possible du cerveau dans la différenciation des gonades reste ouverte. [less ▲]

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See detailMultiqubit symmetric states with maximally mixed one-qubit reductions
Baguette, Dorian ULg; Bastin, Thierry ULg; Martin, John ULg

in Physical Review. A (2014), 90

We present a comprehensive study of maximally entangled symmetric states of arbitrary numbers of qubits in the sense of the maximal mixedness of the one-qubit reduced density operator. A general criterion ... [more ▼]

We present a comprehensive study of maximally entangled symmetric states of arbitrary numbers of qubits in the sense of the maximal mixedness of the one-qubit reduced density operator. A general criterion is provided to easily identify whether given symmetric states are maximally entangled in that respect or not. We show that these maximally entangled symmetric (MES) states are the only symmetric states for which the expectation value of the associated collective spin of the system vanishes, as well as in corollary the dipole moment of the Husimi function. We establish the link between this kind of maximal entanglement, the anticoherence properties of spin states, and the degree of polarization of light fields. We analyze the relationship between the MES states and the classes of states equivalent through stochastic local operations with classical communication (SLOCC). We provide a nonexistence criterion of MES states within SLOCC classes of qubit states and show in particular that the symmetric Dicke state SLOCC classes never contain such MES states, with the only exception of the balanced Dicke state class for even numbers of qubits. The 4-qubit system is analyzed exhaustively and all MES states of this system are identified and characterized. Finally the entanglement content of MES states is analyzed with respect to the geometric and barycentric measures of entanglement, as well as to the generalized N-tangle. We show that the geometric entanglement of MES states is ensured to be larger than or equal to 1/2, but also that MES states are not in general the symmetric states that maximize the investigated entanglement measures. [less ▲]

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See detailDer Einfluss der Historischen Rechtsschule auf Belgien
Gerkens, Jean-François ULg

Scientific conference (2014, September 12)

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See detailWeakening of Jupiter’s main auroral emission in response to magnetospheric hot plasma injections
Badman, Sarah; Bonfond, Bertrand ULg; Fujimoto, M. et al

Conference (2014, September 11)

We present images of Jupiter’s northern UV aurorae taken by the Hubble Space Telescope as part of a large observing campaign in January 2014. The high time resolution observations allow the dynamics of ... [more ▼]

We present images of Jupiter’s northern UV aurorae taken by the Hubble Space Telescope as part of a large observing campaign in January 2014. The high time resolution observations allow the dynamics of the different components of the aurorae to be observed. Particular features of interest are large regions of diffuse emission, which occurred equatorward of the main oval, enveloping the auroral footprint of Ganymede. These diffuse, low latitude emissions are caused by the injection of hot plasma from the outer magnetosphere, a process which has previously been related to interchange between the flux tubes from the outer magnetosphere and outward-moving flux tubes loaded with iogenic plasma. Over the two-week observing interval the auroral signatures of two large injection events were observed, while the main oval generally decreased in intensity. We suggest that the overall dimming of the main oval results from the weakening of the corotation-enforcement currents that drive the main emission, following the replacement of the radially-stretched, mass-loaded flux tubes by more dipolar flux tubes containing rarefied hot plasma. [less ▲]

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See detailHighlights of the 2014 Jupiter observing campaign by multi - spectral remote sensing using space telescopes
Kimura, T.; Badman, S.; Tao, C. et al

Conference (2014, September 11)

From January to April 2014, two observing campaigns by multi-wavelength remote sensing from X-ray to radio were performed to uncover energy transport process in Jupiter’s plasma environment using space ... [more ▼]

From January to April 2014, two observing campaigns by multi-wavelength remote sensing from X-ray to radio were performed to uncover energy transport process in Jupiter’s plasma environment using space telescopes and ground-based facilities. These campaigns were triggered by the new Hisaki spacecraft launched in September 2013, which is an extremely ultraviolet (EUV) space telescope of JAXA designed specifically for planetary observations. In the first campaign in January, Hubble Space Telescope made imaging of far ultraviolet (FUV) aurora with a high special resolution (0.08”) through two weeks while Hisaki continuously monitored aurora and plasma torus emissions in EUV wavelength with a high temporal resolution (1 min<). We discovered new magnetospheric activities from the campaign data: e.g., internally-driven type auroral brightening associated with hot plasma injection, and plasma and electromagnetic filed modulations in the inner magnetosphere externally driven by the solar wind modulation. The second campaign in April was performed by Chandra X-ray Observatory, XMM newton, and Suzaku satellite simultaneously with Hisaki. Relativistic auroral accelerations in the polar region and hot plasma in the inner magnetosphere were captured by the X-ray space telescopes simultaneously with EUV monitoring of aurora and plasma torus. In this presentation, we show remarkable scientific results obtained these campaigns mainly focusing on Jupiter’s aurora. [less ▲]

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See detailEffects of concentrate level on milk production and traffic of grazing cows milked by a mobile automatic milking system on pasture
Lessire, Françoise ULg; Hornick, Jean-Luc ULg; Dufrasne, Isabelle ULg

in Hopkins, Alan; Collins, Rosemary; Fraser, Marieacia (Eds.) et al EGF at 50: The future of European Grasslands (2014, September 10)

Cows milked by an automatic milking system in pastures were assigned in 2 groups receiving different amounts of concentrates (2.1 kg vs 4.1 kg). The effect of concentrates’ level on milk yield (MY) and ... [more ▼]

Cows milked by an automatic milking system in pastures were assigned in 2 groups receiving different amounts of concentrates (2.1 kg vs 4.1 kg). The effect of concentrates’ level on milk yield (MY) and returns to the robot was assessed. Concentrates’ level had a positive influence on daily milk production over the grazing period as cows of low concentrates group produced 21.43 ± 0.62 kg compared with 24.33 ± 0.62 kg in high concentrates group. However this effect was modulated subsequently to grass quality and availability. Regarding daily voluntary returns to the robot, high concentrates group showed higher frequency (3.66 ± 0.05, compared with 3.22 ± 0.04 in low concentrates group) demonstrating positive impact of complement distribution on cows’ traffic. [less ▲]

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