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See detailNavigating the uncertain seas of controversies – A pedagogical wind rose
Verpoorten, Dominique ULg

in Melard, François; Stassart, Pierre M (Eds.) Proceedings of the International Interdisciplinary Working Conference "Teaching complexity and uncertainty on Environmental Issues - Practices, Theories and Products" (2014, December 23)

The Arlon conference brought together lecturers willing to share and discuss aspects of their practice of “controversies”, seen as a teaching/learning method suited to the contextual needs and demands of ... [more ▼]

The Arlon conference brought together lecturers willing to share and discuss aspects of their practice of “controversies”, seen as a teaching/learning method suited to the contextual needs and demands of higher education environmental studies. The paper contributes to this joint reflective effort by providing conceptual tools helping to interpret the practice, to question what it puts at stake and to detect, from a pedagogical viewpoint, key issues and upcoming questions. The contribution falls within the Conference's aim n°2: “share theories or conceptual propositions that make it possible to equip the teaching approaches and to give them theoretical and methodological foundations” (Program Arlon Conference 2014, p. 2). The article takes a traditional stance, looking at the contributions to the conference through “constructive alignment”(Biggs, 1996), a basic principle meant to secure the pedagogical validity of any given learning situation by establishing a triple consistency (Kovertaite & Leclercq, 2006; Leclercq, 1995; Petit, Castaigne, & Verpoorten, 2007; Tyler, 1949) between objectives, methods and assessment. [less ▲]

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See detailThe Politics of National Accounting: Assessing Walloon Public Debt
Piron, Damien ULg

Conference (2014, December 19)

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See detailSize Matters, book-to-market does not! The F&F empirical CAPM revisited
Lambert, Marie ULg; Hübner, Georges ULg

Conference (2014, December 18)

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See detailUncertainty in Training-Image Based Inversion of Hydraulic Head Data Constrained to ERT Data: Workflow and Case Study
Hermans, Thomas ULg; Nguyen, Frédéric ULg; Caers, Jef

Conference (2014, December 18)

In inverse problems, investigating the relationship between data and prior models and the uncertainty related to the posterior distribution of model parameters are as important as matching the data. In ... [more ▼]

In inverse problems, investigating the relationship between data and prior models and the uncertainty related to the posterior distribution of model parameters are as important as matching the data. In recent years, many efforts have been done to assess the posterior distribution of a given problem with reasonable computational costs through inversion techniques such as McMC. The derived posterior distribution is always dependent on the prior distribution. However, most of the studies ignore modeling the prior with realistic uncertainty. In this paper, we propose a workflow to assess the uncertainty of inversion of hydraulic heads data through the addition of electrical resistivity tomography (ERT) constraining data. The workflow is divided in three successive steps: 1) Construction of prior: we generate multiple alternative geological scenarios from literature data (architecture of facies) as well as site specific data (proportions of facies). Spatial uncertainty within each scenario is integrated hierarchically through geostatistics (multiple-point statistics simulation of facies constrained by ERT data as soft data). 2) Validation of prior scenarios: we transform prior facies scenarios into resistivity distribution scenarios through forward and inverse modeling. The scenarios are validated by comparison with field ERT data. The comparison is made through distance calculation and projection into a low dimensional space to calculate the probability of each scenario given field ERT data. 3) Matching dynamical data: we use the probability perturbation method, within each scenario, to integrate hydraulic heads to our models. We account for scenario probabilities, calculated in 2, in determining how many models per scenario we have to consider for building a reliable posterior distribution. As an illustration, the method is applied on a field case study in an alluvial aquifer (Belgium) where we consider prior uncertainty related to the type of elements (gravel channels or bars) and to their size. This study shows the importance of considering the uncertainty of the prior in inverse problems as it has a strong influence on model predictions and decision-making problems. [less ▲]

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See detailAllergie moléculaire & Diagnostic in-vitro, Optimalisation de la prescription
GADISSEUR, Romy ULg

Conference (2014, December 17)

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See detailCancer du sein et retour au travail
Schippers, Nathalie ULg; Van Hoof, Elke; Mairiaux, Philippe ULg

Poster (2014, December 17)

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See detailDe l’intention au comportement physiquement actif chez les seniors : étude de l’influence des perceptions environnementales
Mouton, Alexandre ULg; Peels, Denise; Bolman, Catherine et al

Conference (2014, December 17)

The aim of this study was to analyse whether the perception of the local opportunities and the perception about the quality of the environment for physical activity (PA) mediate or moderate the intention ... [more ▼]

The aim of this study was to analyse whether the perception of the local opportunities and the perception about the quality of the environment for physical activity (PA) mediate or moderate the intention-behaviour relationship for PA in older adults. Data from two existing longitudinal studies (n = 149 and n = 1262) were used, assessing intention at baseline (T1), environmental variables at six months (T2) and PA behaviour at one year (T3). Results exposed a significant mediating role of the perception of the local PA opportunities (accounting for 15.5% in study 1 and 11.9% in study 2) and of the perception about the quality of the PA environment (accounting for respectively 19.6% and 18.2%) on the intention-behaviour relationship for PA. A moderation effect on the intention-behaviour relationship for PA was found in participants with a moderate perception of the local PA opportunities and in participants with a low or moderate perception about the quality of the environment for PA in both studies. This is the first longitudinal study that provides insight in the mediating and moderating role of environmental perceptions in the intention-behaviour relation for PA. Improving environmental perceptions could help future PA promotion interventions to bridge the intention-behaviour gap. [less ▲]

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See detailVieillissement réussi: quel lien avec la qualité de vie des personnes âgées?
Missotten, Pierre ULg; Dupuis, Gilles; Adam, Stéphane ULg

Conference (2014, December 16)

Introduction: Selon des théories du « bien vieillir », un sujet doit 1) vivre dans le présent et se focaliser sur des informations émotionnelles positives si il a un sentiment de finitude élevé (FTP)1 ; 2 ... [more ▼]

Introduction: Selon des théories du « bien vieillir », un sujet doit 1) vivre dans le présent et se focaliser sur des informations émotionnelles positives si il a un sentiment de finitude élevé (FTP)1 ; 2) sélectionner des tâches prioritaires (SOC-Sélection) pour les pratiquer plus (SOC-Optimisation) tout en modifiant ses manières de procéder (SOC-Compensation)2 ; 3) réajuster ses buts en tenant compte des limitations de l’environnement ou du self (Flexibilité) et non essayer de changer la situation existante (Ténacité)3. Si on peut penser que ces théories sont liées à la qualité de vie (qdv), aucune recherche empirique n’a testé ces liens. Méthodologie: Cette étude investigue dans quelle mesure les opérationnalisations de trois théories du vieillissement réussi (SOC, FTP, Flexibilité-Ténacité) sont bien liées à la qualité de vie (WHOQOL-OLD et ISQV-65+ bref©) de personnes âgées de plus de 65 ans vivant à domicile (n=61). Résultats: Un faible sentiment de finitude (FTP), une tendance à investir son énergie dans les buts importants (SOC-Optimisation), à chercher des alternatives (SOC-Compensation) et une bonne capacité de réajustement des buts (Flexibilité) constituent des indices liés à une meilleure Qdv (tous r>.30 mais <.70; p<.05). Conclusion: Le vieillissement réussi est bien lié à la qdv: les deux concepts sont différents mais complémentaires. En regard de la théorie FTP, il est toutefois nécessaire de déterminer si la mauvaise qdv des sujets ayant un sentiment de finitude élevé est causée par le fait de ne pas vivre dans le présent et de ne pas s’orienter vers des buts émotionnels. 1. Carstensen, L. (1995). Current Directions in Psychological Science, 4, 151-156. 2. Baltes & Baltes (1990). In P. B. Baltes & M. M. Baltes (Eds.), Successful aging: Perspectives from the behavioral sciences (pp. 1–34). New York: Cambridge University Press. 3. Brandtstädter, J. & Renner, G. (1990). Psychology and Aging 5 (1), 58–67. [less ▲]

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See detailEnvironmental changes in developing countries: from moving to trapped populations
Ozer, Pierre ULg; De Longueville, Florence ULg; Zickgraf, Caroline ULg et al

in Young Researchers Overseas' Day - Book of Abstracts (2014, December 16)

Over the last decades, environmental changes driven and/or compounded by population pressures and climate change have dramatically impacted human mobility, including population displacements or migration ... [more ▼]

Over the last decades, environmental changes driven and/or compounded by population pressures and climate change have dramatically impacted human mobility, including population displacements or migration, especially in developing countries. Slow onset degradation processes (aridification, desertification, wind and water erosion, deforestation, shoreline erosion, etc.) and sudden disasters (extreme climate events such as floods, droughts, storms, heat waves, etc.) have intensified since the 1950s in terms of frequency, intensity and duration, as well as in their socio-economic consequences. In the absence of an international objective to reduce greenhouse gas emissions, global warming and its wide range of negative impacts are not likely to be contained in the future [...] [less ▲]

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See detail"Gérer ses émotions et agir : Pleine conscience et ACT" : Etude préliminaire de l'efficacité d'un groupe thérapeutique
Wagener, Aurélie ULg; Dierickx, Christophe; Herbeuval, Sandrine et al

Poster (2014, December 16)

Introduction : L’apprentissage de la gestion des émotions est une demande très fréquente en psychothérapie. Les techniques issues des programmes de pleine conscience et des thérapies d’acceptation et ... [more ▼]

Introduction : L’apprentissage de la gestion des émotions est une demande très fréquente en psychothérapie. Les techniques issues des programmes de pleine conscience et des thérapies d’acceptation et d’engagement ont notamment pour objectif de guider les clients dans cet apprentissage. Afin de répondre à cette demande, nous avons mis en place un groupe « Gérer ses émotions et agir : pleine conscience et ACT » et mené une recherche-action afin d’en tester l’efficacité. Méthodologie : Le cycle thérapeutique comportait 3 séances (3x3 heures) sur un délai de 6 semaines et 2 temps d’évaluation (avant la première séance [T0] et après la dernière [T1]). Les évaluations adminis-trées aux différents temps concernaient les données socio-démographiques, l’humeur, le niveau de pleine conscience, la flexibilité psychologique, le niveau d’engagement dans des activités, la mo-tivation et le sentiment d’auto-efficacité. Résultats : Cinq adultes (M âge = 37,46; ET = 7,96) ont participé à ce premier cycle. Les analyses prélimi-naires indiquent un effet significatif du facteur temps (N = 5). Ainsi, une augmentation du niveau d’engagement dans des activités (F(1) = 20,07, p = 0,01), de la motivation (F(1) = 15,00, p = 0,02) et du sentiment d’auto-efficacité (F(1) = 17,48, p = 0,02) est observée entre le T0 et le T1. Conclusion : Les résultats préliminaires semblent indiquer que les participants au groupe thérapeutique tirent des bénéfices de la participation à ce cycle thérapeutique. La récolte des données et la constitution d’un groupe contrôle se poursuivent. Les résultats seront plus longuement discutés lors du congrès. [less ▲]

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See detailHistoWeb - Toward a new learning ecology for histology
Vincke, Grégoire ULg; Marée, Raphaël ULg; Wehenkel, Louis ULg et al

Conference (2014, December 16)

HistoWeb targets the transformation of the professional tool Cytomineinto a comprehensive and innovative teaching platform, valuing the notions of learning ecology and new learning dimensions seeking for ... [more ▼]

HistoWeb targets the transformation of the professional tool Cytomineinto a comprehensive and innovative teaching platform, valuing the notions of learning ecology and new learning dimensions seeking for lifelong competencies. The poster was released at the Digital Learning round table, organized by the European Commission around H2020 funding instruments and call 2 "ICT-20 Technologies for better human learning" [less ▲]

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See detailAnxiété et dépression chez l'enfant parentifié. Mieux identifier pour mieux intervenir.
Haxhe, Stéphanie ULg; Stassart, Martine ULg; D'Amore, Salvatore ULg

Poster (2014, December 16)

La parentification reste un phénomème mal connu. Pourtant, les conséquences pour l'enfant sont à prendre au sérieux.

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

Poster (2014, December 16)

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See detailUnstudied species of Lepilemur of Northwest Madagascar
Wilmet, Leslie ULg; Beudels-Jamar, Roseline C.; Schwitzer, Christoph et al

Poster (2014, December 16)

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See detailProgramme de revalidation multidisciplinaire post-cancer du sein : analyse des bénéfices éventuels sur la fonction physique et la qualité de vie
LECLERC, Anne-France ULg; FOIDART-DESSALLE, Marguerite ULg; COUCKE, Philippe ULg et al

in AFPSA - 8e congrès francophone, Psychologie de la Santé - Evolutions sociales, innovations & politiques - Résumé des communications (2014, December 16)

Introduction : Le cancer du sein ainsi que ses traitements sont à l'origine de nombreux effets secondaires indésirables. L'objectif de l'étude est de déterminer les bénéfices éventuels, tant sur le plan ... [more ▼]

Introduction : Le cancer du sein ainsi que ses traitements sont à l'origine de nombreux effets secondaires indésirables. L'objectif de l'étude est de déterminer les bénéfices éventuels, tant sur le plan physique que psychologique, d’un programme de revalidation multidisciplinaire chez des femmes ayant été traitées pour un cancer du sein. Méthodologie : 122 patientes ont été recrutées, 61 faisant partie du groupe contrôle et 61 du groupe traité. Celui-ci a bénéficié d’une revalidation de trois mois comprenant un entraînement physique supervisé et diverses sessions psycho-éducatives. Les évaluations, effectuées avant et après la prise en charge, ont inclus des mesures anthropométriques et de composition corporelle, une évaluation des capacités fonctionnelles et différents questionnaires. Résultats : Au terme des trois mois, l’état de santé (qualité de vie), le rôle fonctionnel, l’état émotionnel et les fonctions physiques, cognitives et sociales s’améliorent significativement au sein du groupe traité. Cette observation s’applique également aux symptômes de fatigue, d'insomnie, de douleur, de dyspnée, de perte d'appétit, d’anxiété et de dépression ainsi qu'aux paramètres physiques obtenus par l'intermédiaire des évaluations fonctionnelles. Au sein du groupe contrôle, ces améliorations n’apparaissent pas et une augmentation significative de l'indice de masse corporelle et du pourcentage de graisse corporelle est observée. Conclusion : Cette étude préliminaire montre ainsi la faisabilité et les effets bénéfiques d’une prise en charge multidisciplinaire chez des femmes au terme de leurs traitements pour le cancer du sein. [less ▲]

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See detailLe genre Erythrophleum (Fabaceae) en Afrique, un modèle pour l’étude des mécanismes de différenciation de niches climatiques
Gorel, Anaïs ULg; Duminil, Jérôme; Doucet, Jean-Louis ULg et al

Conference (2014, December 16)

Comprendre l’origine des patrons de diversité est un défi en écologie des communautés et en écologie évolutive, notamment dans le contexte du futur changement climatique. Ce poster aura deux objectifs : i ... [more ▼]

Comprendre l’origine des patrons de diversité est un défi en écologie des communautés et en écologie évolutive, notamment dans le contexte du futur changement climatique. Ce poster aura deux objectifs : i) présenter pourquoi le genre Erythrophleum en Afrique est un modèle d’étude idéal à la compréhension des mécanismes de différenciation de niche et de spéciation au sein d’une lignée d’arbre en région tropicale; ii) mettre en lumière les démarches statistiques et expérimentales permettant de valider et de comprendre ces mécanismes. Le genre Erythrophleum, largement distribué en Afrique, est représenté par quatre espèces d’arbre : E. ivorense, E. suaveolens, E. africanum et E. lasianthum. Ces espèces morphologiquement très proches, présentent des aires de distribution géographiques et climatiques adjacentes. Elles sont distribuées de façon parapatrique sur un gradient pluviométrique, du plus humide pour E. ivorense ou plus sec pour E. lasianthum. Ce mode de distribution apparent, combiné à des données issues d’études phylogénétiques, suggère un rôle majeur des gradients climatiques comme pilotes des différenciations spécifiques du genre et pourrait donc confirmer l’hypothèse du gradient écologique (« The ecological gradient hypothesis » suppose que des gradients environnementaux peuvent induire des spéciations parapatriques sans que les populations ne soient isolées géographiquement. Néanmoins, des études sur les niches climatiques et leurs degrés de conservatisme sont indispensables pour valider cette hypothèse. Aujourd’hui, ces études sont rendues plus aisées grâce au développement de nouvelles techniques de modélisation des niches environnementales (Species Distribution Model ou SDM) et de tests statistiques de quantification du conservatisme/divergence de niche (voire Warren et al., 2008). En complément de la modélisation des niches observées (c.à.d. niches réalisées selon la définition de Hutchison (1957)), il est intéressant de comprendre les stratégies fonctionnelles sous-jacentes aux différenciations de niche. Les différenciations de niche au sein des espèces du genre sont probablement issues d’une distinction de leurs stratégies d’utilisation des ressources (lumière/eau) et de leurs différents positionnements au sein du slow-fast continuum (sensu Reich, 2014). Cette hypothèse peut être testée par la mise en place d’expériences en milieu contrôlé mesurant les réponses des individus à des stress environnementaux. [less ▲]

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See detailRuzagayura, la grande famine du Rwanda moderne
Singiza, Dantès ULg

Poster (2014, December 16)

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See detailPersonnel soignant et âgisme: quelles conséquences cliniques ?
Schroyen, Sarah ULg; Missotten, Pierre ULg; JERUSALEM, Guy ULg et al

Conference (2014, December 16)

Introduction : Le cancer est un problème de santé majeur dont l’âge constitue un facteur de risque avéré1. Paradoxalement, les personnes âgées souffrant d’un cancer sont souvent exclues des essais ... [more ▼]

Introduction : Le cancer est un problème de santé majeur dont l’âge constitue un facteur de risque avéré1. Paradoxalement, les personnes âgées souffrant d’un cancer sont souvent exclues des essais cliniques et sous-traitées comparativement à des patients plus jeunes1. Un élément explicateur de ces constats est la stigmatisation liée à l’âge² (c.à.d. nos stéréotypes liés à l’âge, et donc l’âgisme). Méthodologie : Nous avons interrogé 76 infirmiers (-ères) travaillant en oncologie. A l’aide de fiches cli-niques, nous leur avons demandé s’ils encourageraient à des patients un traitement expérimental (40 vs 70 ans), une chimiothérapie ou une reconstruction mammaire (35, 55 ou 75 ans), tout paramètres cliniques étant équivalents par ailleurs. Résultats : L’encouragement d’un traitement expérimental est moins fréquente pour une personne de 70 ans comparativement à une personne de 40 ans (p<.001). De plus, le personnel soignant encourage moins fréquemment une chimiothérapie pour une personne de 75 ans comparativement aux per-sonnes de 55 et 35 ans (p<.001). Au niveau de la reconstruction mammaire, une différence est vi-sible dès 55 ans : la reconstruction mammaire est moins encouragée pour une personne de cet âge par rapport à une personne de 35 ans (p=.02) et encore moins encouragée pour une personne de 75 ans comparativement à une personne de 55 ans (p<.001). L’âge des infirmiers (M = 35.8) a une influence sur ces encouragement : plus ils sont âgés, plus ils encouragent le traitement chimiothérapeutique d’une per-sonne de 75 ans (p = .005) de même que le traitement expérimental pour une personne de 70 ans (p = .01). Conclusion : A l’instar d’autres études3, 4, nous confirmons que tant du point de vue esthétique que cura-tif, le personnel médical encourage moins fréquemment un traitement aux patients plus âgés compa-rativement aux plus jeunes. 1. Hurria, A., et al. (2012). J Natl Compr Canc Netw, 10, 162-209. 2. Penson, R. T., et al. (2004). The Oncologist, 9, 343-352. 3. Madan, A. K., et al. (2001). Acad Med, 76, 282-284. 4. Protière, C., et al. (2010). Crit Rev Oncol Hematol, 75, 138-150. [less ▲]

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See detailPhytochemical Study of Plants of Interest for Cosmetics in Mayotte
Saive, Matthew ULg; Fauconnier, Marie-Laure ULg; Danflous, Jean-Paul

Poster (2014, December 16)

This study takes place in a bigger project aiming to identify and to make an inventory of the French Pharmacopeia. Its aim is to identify plants or plant families regularly used in traditional cosmetics ... [more ▼]

This study takes place in a bigger project aiming to identify and to make an inventory of the French Pharmacopeia. Its aim is to identify plants or plant families regularly used in traditional cosmetics in Mayotte. In order to give a direction to the research, two technics where used. At first, the plants and their families used in the pharmacopeia of neighboring regions were inventoried using the literature. The resulting inventory was then compared with the flora of the Mahoran territory. The second technique was the realization of a semi-structured survey with people known for their plant-use knowledge in Mayotte. In order to have significant results, the ethnobotanical survey was done following Trotter & Logan’s protocol. (1986) According to that protocol, the gathered data has to be the following: common name, place of harvest, part used and the posology. Moreover the number of informant has to be big enough in order to integrate the data in several indicators such as: The informant agreement ration (IAR), the fidelity level (FL) and use value (UV). The number of informant was determined based on the population density of the different communes of the island. Another critical factor for this study is the correct identification of each sample. To achieve that when a sample was realized, it was taken twice. One for the analysis, the second sample was pressed and dried so as to enter a herbarium for identification. The last important step of this part of the study is the development of fast technics to establish the samples’ physiological activity. These test will give us qualitative information in order the isolate the plants that show a true potential. The targeted activities and tests being: - Anti-tyrosinase activity through an inhibition of tyrosinase test. - Anti-free-radicals activity through the DPPH test. - Anti-inflammatory activity through an inhibition of lipoxygenase an cyclooxygenase test The following steps of the study is the complete analysis of the physiologically active plants extracts in order to identify the active molecules. The end of the study will result in the creation of cosmetics originating from Mayotte’s flora. The way the cosmetics will be developed is thought so as it can be easily and durably done in Mayotte allowing this study to have a positive impact on the development of the island. [less ▲]

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See detailComment conceptualiser les liens entre caractéristiques dépressives, processus psychologiques et niveau d'engagement dans des activités (activation versus évitement) ? Implications en psychologie clinique
Wagener, Aurélie ULg; Blairy, Sylvie ULg; Baeyens, Céline

Conference (2014, December 16)

Introduction : La dépression est caractérisée par une diminution du niveau d’activation comportementale (ACT) et par une augmentation du niveau d’évitement (EV). Selon les modèles théoriques de la dépres ... [more ▼]

Introduction : La dépression est caractérisée par une diminution du niveau d’activation comportementale (ACT) et par une augmentation du niveau d’évitement (EV). Selon les modèles théoriques de la dépres-sion, elle est également caractérisée par des biais dans six ensembles de processus psychologiques (PP): pensées négatives répétitives, stratégies de régulation émotionnelle, satisfaction environne-mentale, tendance à l’approche ou à l’inhibition, image de soi et clarté de l’identité. Cette étude a pour objectif de préciser l’influence des caractéristiques dépressives et des PP sur l’ACT et l’EV. Ces résultats seront intégrés au modèle élaboré par Kinderman en 2013 afin de construire un mo-dèle conceptuel de l’ensemble de ces liens, fondé empiriquement. Méthodologie : 477 adultes ( âge = 34, σ = 12), issus d’échantillons tout-venants ou fréquentant des services de psychiatrie, ont rempli une série de questionnaires évaluant plusieurs variables: données sociodé-mographiques, dépression, ACT, EV et les six ensembles de PP cités ci-dessus. Résultats : Le modèle testé via des analyses factorielles confirmatoires présente une adéquation raisonnable (RMSEA = 0,8). L’ACT est le plus influencée par des stratégies de régulation émotionnelle adap-tatives, des hauts niveaux de satisfaction environnementale et une image de soi positive. L’EV est le plus influencé par des pensées négatives répétitives, des stratégies de régulation émotionnelle non-adaptatives et de faibles niveaux de satisfaction environnementale. Conclusion : Les stratégies de régulation émotionnelle et la satisfaction environnementale sont les deux fac-teurs influençant le plus les niveaux d’ACT et celui d’EV. Les implications cliniques de ces résultats seront discutées. [less ▲]

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See detailVariability of Jupiter’s Main Auroral Emission in Response to Magnetospheric Hot Plasma Injections
Badman, Sarah; Bonfond, Bertrand ULg; Fujimoto, Masaki et al

Poster (2014, December 16)

We present observations of Jupiter’s FUV aurora acquired by the Hubble Space Telescope during a two-week interval in January 2014. The variability of the main auroral emission was studied using ... [more ▼]

We present observations of Jupiter’s FUV aurora acquired by the Hubble Space Telescope during a two-week interval in January 2014. The variability of the main auroral emission was studied using latitudinal profiles of intensity. The main oval intensity was found to be reduced when bright patches of diffuse emission were present at lower latitudes. These low latitude emissions are interpreted as the signatures of hot plasma injections 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. The main emission was also observed to broaden and shift in latitude, and occasionally display a double peak structure. These observations are interpreted with reference to the expected changes in auroral field-aligned currents associated with the replacement of the radially-stretched, mass-loaded flux tubes in the middle magnetosphere by more dipolar flux tubes containing rarefied hot plasma. [less ▲]

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See detailCorporate Board Attributes and Conditional Accounting Conservatism Evidence from French Firms
Boussaid, Nabila ULg; Sougné, Danielle ULg; Hamza, Taher

Conference (2014, December 16)

In this paper we investigate the relationship between boards of directors’ attributes and conditional accounting conservatism in the French context. Using a pooled regression model to evaluate this ... [more ▼]

In this paper we investigate the relationship between boards of directors’ attributes and conditional accounting conservatism in the French context. Using a pooled regression model to evaluate this relationship for the period 2009-2012, our empirical results can be summarized as follows. Firstly, greater board activity encourages more conservative reporting in financial statements. Secondly, greater board size diminishes conditional accounting conservatism. Lastly, there is a positive relationship between gender diversity and conservatism. To ensure robustness we have calculated our results usingalternative measures of accounting conservatism, namely time series and accrual-based measures in addition to asymmetric timeliness of earnings. These findings suggest that boards of directors’ attributes are an important factor in determining the financial reporting quality of French firms. [less ▲]

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See detailPerception du bien-être chez les étudiants de l’Université de Liège
Cloes, Marc ULg; Etienne, Anne-Marie ULg; Maslah, Olfa et al

Conference (2014, December 15)

This study is focused on the analysis of the wellness perception of a representative sample of students of the University of Liege. Findings confirm those of the literature as males at students who ... [more ▼]

This study is focused on the analysis of the wellness perception of a representative sample of students of the University of Liege. Findings confirm those of the literature as males at students who consider to be physically active have higher scores of wellness. The study reveals also that students who are still leaving with their parents have higher scores of wellness. [less ▲]

Detailed reference viewed: 44 (8 ULg)
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See detailRelation entre fatigue et travail chez des patients atteints de sclérose en plaques
DELRUE, Gaël ULg; Blavier, Adelaïde ULg; Hennen, Julie et al

Poster (2014, December 15)

Fatigue is one of the most frequent symptom in multiple sclerosis patients (MS patients). We showed significant correlations between fatigue levels and difficulties encountered by our patients at work ... [more ▼]

Fatigue is one of the most frequent symptom in multiple sclerosis patients (MS patients). We showed significant correlations between fatigue levels and difficulties encountered by our patients at work evaluated through a specific questionnaire we already validated . This complaint must be carefully managed by professionnals in order to help the patients cope with it in the best way for maintaining work situation. [less ▲]

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See detailMulti-wavelength observations of Jupiter's aurora coordinated with Hisaki and other space telescopes
Kimura, Tomoki; Badman, Sarah; Tao, Chihiro et al

Conference (2014, December 15)

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 for planetary observations. In the first campaign in January, Hubble Space Telescope (HST) 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 (CXO), 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. Auroral intensity in EUV indicated a clear periodicity of 45 minutes whereas the periodicity was not evident in X-ray intensity although previous observations by CXO indicated clear 40-minute periodicity in the polar cap X-ray aurora. In this presentation, we show remarkable scientific results obtained these campaigns. [less ▲]

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See detailTiming pubertaire perçu et conduites à risque et déviantes à l’adolescence
Glowacz, Fabienne ULg

Conference (2014, December 15)

Le processus de maturation pubertaire a des répercussions sur la représentation de soi et sur l’établissement des relations sociales à l’adolescence. La poussée staturo-pondérale, comme l’atteinte de la ... [more ▼]

Le processus de maturation pubertaire a des répercussions sur la représentation de soi et sur l’établissement des relations sociales à l’adolescence. La poussée staturo-pondérale, comme l’atteinte de la maturité sexuelle, ne se produisent pas en même temps chez tous les adolescents. Cette variabilité interindividuelle a des effets au niveau de la construction identitaire, de la perception de soi et du rapport aux autres. Nos recherches se centrent sur les liens entre le timing pubertaire et l’engagement dans des comportements délictueux, usage de drogue, conduites sexuelles et autres comportements exploratoires et déviants. Notre recherche porte sur un échantillon de 316 adolescents âgés de 13 à 18 ans, et un échantillon de 47 adolescents ayant commis une agression sexuelle. L’estime de soi, l’agressivité, les relations aux pairs, les comportements sexuels, les conduites délinquantes et le timing pubertaire perçu (TPP) ont été évalués pour chaque sujet. Des analyses comparatives entre les types de TPP (avancé-retardé-normal) ont permis d’analyser l’impact de la perception par l’adolescent d’une désynchronisation de son timing pubertaire au niveau des dimensions étudiées et de l’adoption de conduites à risque et déviantes. Nos résultats montrent une surreprésentation de « pubertés» décalées (avancées ou retardées) chez les adolescents engagés dans des conduites à risques et des conduites déviantes au niveau de la sexualité. Ils seront discutés dans une perspective bio-psychosociale à partir des théories développementales. [less ▲]

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See detailFirst monitoring results of three straw bale buildings in Belgium
Evrard, Arnaud; Dubois, Samuel ULg; Louis, Arnaud et al

Conference (2014, December 13)

Straw bale use in buildings may be an interesting way to decrease our energy needs and our impact on environment. The present paper describes an experimental set up to monitor three straw bale buildings ... [more ▼]

Straw bale use in buildings may be an interesting way to decrease our energy needs and our impact on environment. The present paper describes an experimental set up to monitor three straw bale buildings recently built in Belgium. For each building, results on temperature and relative humidity, inside and outside, are analyzed, as well as internal evolution of temperature and humidity distribution in the walls. The first building is an office building where two finishing are compared. Measurements also provide additional data on CO2 levels and electric consumption. The two other buildings are dwellings where live one single family. In the first one, a wall in the bedroom and a retaining wall are analyzed. In the second one, a wall in the bedroom and a wall in the bathroom are analyzed. Their hygrothermal behavior is discussed based on simulation results obtained with WUFI Pro and WUFI Plus software. The criterion for the validation of wall behavior is based on water content distribution through the walls. The paper confirms the great potential of this type of building technology and helps to identify how to assess and validate their effective hygrothermal behavior. [less ▲]

Detailed reference viewed: 37 (1 ULg)
See detailBelgien- und Deutschlandbilder als Spiegel der ostbelgischen Nachkriegsgesellschaft
Brüll, Christoph ULg

Conference (2014, December 13)

Detailed reference viewed: 9 (0 ULg)
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See detailDetection of rRNA synthesis sites within reptilian nucleoli
Bartholomé, Odile ULg; Thiry, Marc ULg; Franck, Claire

Poster (2014, December 13)

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See detailDe quoi Radius est-il le nom? Enjeux et enseignements de la création d'une cellule de reporting institutionnel dans une université.
Hoerner, Céline ULg; Bachelet, Jean-François ULg

Conference (2014, December 13)

The contemporary university has to deal with an important pressure in order to adopt an operating and organisational system from the companies. The university is now encouraged to reconcile efficacy and ... [more ▼]

The contemporary university has to deal with an important pressure in order to adopt an operating and organisational system from the companies. The university is now encouraged to reconcile efficacy and financial viability goals in a competitive context between institutions. On the basis of a case study undertaken in a french--¿speaking Belgian university, we will think about the way dashboards and institutional reporting enable the university to respond to change injunctions, how they constitute a strategic management support, as well as the effects of their implementation in the administrative organisation. We will explain why Radius has been created at the university, its structure and how it works. We will see that its impact has been significant on the institution¿s staff. The creation of Radius, which aroused misgivings from administrations who have lost some of their prerogatives, reflects a shift of the administrative activity, whose part of the power is now concentrated in the hands of the authorities. [less ▲]

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See detailNew technologies in conservation: monitoring African wildlife with UAS
Linchant, Julie ULg; Semeki, Jean; Lejeune, Philippe ULg et al

Conference (2014, December 13)

In the vast protected areas of Africa, traditional wildlife surveys performed by plane or foot are logistically difficult to implement due to the lack of means and appropriate materials. Moreover, the ... [more ▼]

In the vast protected areas of Africa, traditional wildlife surveys performed by plane or foot are logistically difficult to implement due to the lack of means and appropriate materials. Moreover, the possibilities of encountering poachers in the field pose a serious risk to the monitoring teams. Over the last decade, civilian UAS (Unmanned Aerial Systems) boomed in natural resource monitoring. One of the biggest challenges of the UAS is to replace traditional wildlife censuses for the application of wildlife conservation. Parameters have to be approached in a different way than before. We performed test flights in the open savannah of the Garamba National Park during the wet season using the Falcon Unmanned UAS. Both photos (Sony Nex7, 24Mp) and videos, including thermal infrared videos (Tamarisk 640x480), have been used. Flight altitude ranged from 50 to 200m and pictures showed that animals can be effectively detected at 100m. We spotted elephants, hippopotamus and buffaloes as well as other smaller species such as hartebeests, kobs and warthogs. Thermal videos gave medium quality results during the day due to the heat but performed well during the night. The limited range and endurance of the UAS suggest a rethink of the usual census protocols. We therefore tested new flight plans in a rosette shape to take advantage of the higher points in the park, with transects having the length of the maximal range. Twelve transects of 10km can be covered in half a day with pictures covering a 15.6km² area. Human activities could also be detected. Pictures showed areas burned by poachers and the thermal infrared camera allows the detection of fires from a high altitude. Future developments need to be investigated such as automatic detection to review the huge amount of data collected and statistical methods must be adapted to those challenging situations. [less ▲]

Detailed reference viewed: 39 (9 ULg)
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See detailBelowground Chemical Ecology: The Case of Wireworms
Barsics, Fanny ULg; Delory, Benjamin ULg; Delaplace, Pierre ULg et al

Conference (2014, December 13)

Detailed reference viewed: 13 (6 ULg)
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See detailLiquidity patterns on the US corporate bond market
Heck, Stéphanie ULg; Margaritis, Dimitri; Muller, Aline ULg

Conference (2014, December 13)

Liquidity commonality exists and empirical evidence (e.g. Lin et al., 2011) indicates that exposure to this common liquidity factor is priced in the cross-section of corporate bonds. The existence of ... [more ▼]

Liquidity commonality exists and empirical evidence (e.g. Lin et al., 2011) indicates that exposure to this common liquidity factor is priced in the cross-section of corporate bonds. The existence of commonality implies that part of a bond’s illiquidity is left as idiosyncratic. In this paper, we study how illiquidity components explain the cross-section of bond yields and how this relationship varies over time and across bond categories. We use a factor decomposition to break down total illiquidity into a common and an idiosyncratic component and analyze how yields relate differentially to each of these two components. We find that a bond’s idiosyncratic illiquidity is important, which might reflect informational asymmetries compounded by the lack of diversification in the institutional investors’ portfolios. Moreover, the relation between illiquidity and yield spreads appears to be negative during the recent crisis period. [less ▲]

Detailed reference viewed: 27 (3 ULg)
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See detailTuta absoluta (Lepidoptera: Gelechiidae) ability to localize and develop on wild and cultivated solanaceous plant species
Bawin, Thomas ULg; Dujeu, David ULg; Fagan, Maud ULg et al

Conference (2014, December 13)

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important cultivated solanaceous crop plants, including tomatoes and potatoes. Little ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important cultivated solanaceous crop plants, including tomatoes and potatoes. Little is known about the ability of this microlepidoptera to encounter and develop on alternative wild and agricultural plant species. These plants could provide refuges and have to be identified for more efficient integrated management strategies. In the present study, we assessed the ability of T. absoluta to develop on wild (Solanum nigrum, Atropa belladonna, Datura stramonium) and cultivated (Solanum tuberosum) solanaceous plant species under laboratory conditions. Fitness tests were performed in Petri dishes by isolating single individuals with excised leaf from one of the host plants. We found that Solanum species allowed higher larval survivability and shorter development time (from egg to adult emergency) compared to the other plants. Two choice behavioral assays performed in flying tunnels (S. tuberosum versus another plant) revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to the other tested plants. These results appeared to be consistent with survival rates and development times. Because larval survivability depends on the female’s oviposition choice, the hypothesis that host plant choice is influenced by plant volatile organic compounds has to be tested. It can be concluded that Solanum species remain the more suitable hosts for T. absoluta development among the tested plants. Other plant species could be opportunistically colonized with little incidence but care should be taken in these results as genetic variability in insects and plants, as well as plant physiological state, might have an impact on the pest survivabilty. [less ▲]

Detailed reference viewed: 79 (24 ULg)
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See detailEvaluation of two capture methods in the assessment of species richness of eusocial bees in Gabon
Fabre Anguilet, Edgard ULg; Bengone Ndong, Toussaint; Francis, Frédéric ULg et al

Poster (2014, December 13)

Detailed reference viewed: 13 (0 ULg)
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See detailMarty and the 4th Logical Investigation: What is the disagreement really about?
Seron, Denis ULg

Conference (2014, December 13)

Detailed reference viewed: 49 (2 ULg)
Peer Reviewed
See detailA gammaherpesvirus infection protects against allergic asthma.
Machiels, Bénédicte ULg; Dourcy, Mickael ULg; Sabatel, Catherine ULg et al

Poster (2014, December 12)

The “hygiene hypothesis” proposes that the augmentation of allergic diseases in developed countries could be linked to a reduced exposure to infections during childhood. Surprisingly, the potential ... [more ▼]

The “hygiene hypothesis” proposes that the augmentation of allergic diseases in developed countries could be linked to a reduced exposure to infections during childhood. Surprisingly, the potential protective role of herpesvirus infections against allergy development has never been addressed directly. In this study, we used the Murid herpesvirus 4 (MuHV-4) to study the impact of a persistent gammaherpesvirus infection on the development of House Dust Mites (HDM)-induced allergic asthma. Our results revealed that MuHV-4 infection affects both the sensitization and the challenging phases of HDM-induced airway allergy. In particular, we highlighted that MuHV-4 infection strongly impacts the lung innate immune response. Indeed, while the dendritic cells remained competent to uptake antigens and to migrate to the draining lymph nodes, MuHV-4 infection impaired their ability to trigger HDM sensitization. In the future, these results could allow us to develop strategies to prevent the development of TH2-skewed responses against respiratory allergens. [less ▲]

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See detailOpen Access, dream or reality for scholars: The ULg experience
Thirion, Paul ULg

Conference (2014, December 12)

Since the “serial price crisis”, no institution in the world has been able anymore to provide to scholars with the scientific literature they need. Although it was the first reason why the scientific ... [more ▼]

Since the “serial price crisis”, no institution in the world has been able anymore to provide to scholars with the scientific literature they need. Although it was the first reason why the scientific community developed Open Access initiatives, it’s absolutely not the only one. Nowadays, the awareness has become so large that many research players have put OA on the agenda (NIH, WHO, H2020, Wellcome Trust, FRS-FNRS…). The two main existing complementary ways will be described (Green and Gold) and Fools’ Gold will be denounced (unfair gold, hybrid journals, predatory journals). The University of Liege is one of the world leaders in OA with Green and Gold initiatives. What benefits can scholars expect from OA as authors and as readers on the basis of that experience? [less ▲]

Detailed reference viewed: 59 (7 ULg)
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See detailAre amphipods influenced by Posidonia oceanica seagrass features?
Sturaro, Nicolas ULg; Lepoint, Gilles ULg; Michel, Loïc ULg et al

Poster (2014, December 12)

In the Mediterranean Sea, the seagrass Posidonia oceanica plays an important role as habitat for invertebrates, among which amphipod crustaceans represent a dense and diverse assemblage. Recent studies ... [more ▼]

In the Mediterranean Sea, the seagrass Posidonia oceanica plays an important role as habitat for invertebrates, among which amphipod crustaceans represent a dense and diverse assemblage. Recent studies have observed that amphipod density and biomass vary significantly on small spatial scales. This patchiness may be caused by different factors, such as recruitment, competition, and predation; however, habitat features, resulting in availability of resources such as food or shelter, may also be important in structuring these assemblages. This study examined the relationships between amphipod and habitat features in a P. oceanica meadow of the Revellata Bay (Corsica). The sampling was carried out in a continuous meadow colonizing soft substrates at constant depth in August 2008. We quantified the density and biomass of each amphipod species, as well as habitat features, namely shoot density, leaf and epiphyte biomasses, percentage of leaves per shoot having alteration marks and litter biomass. Using multiple regression analyses, few weak significant relationships were identified between amphipod and habitat features. The number of species and the diversity appeared unaffected by the measured habitat features. In contrast, total amphipod density and biomass were generally positively related to the shoot density and epiphyte biomass of P. oceanica, respectively. Overall, habitat features accounted for 0-30% of the variation in the densities of the amphipod species. A distance-based linear model explained a total of 25.8% of the variation of the amphipod assemblages (of which 18.6% was explained by litter biomass). Amphipods are therefore influenced by some P. oceanica features, but only weakly. Furthermore, some features appeared to influence individual species whereas others functioned at the assemblage level. The main challenge remains in evaluating the scale at which these features act and the way in which they influence the structure of assemblages. [less ▲]

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See detailShedding light on two unstudied species of Lepilemur in Northwest Madagascar
Wilmet, Leslie ULg; Beudels-Jamar, Roseline C.; Schwitzer, Christoph et al

Poster (2014, December 12)

Detailed reference viewed: 23 (2 ULg)
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See detailUmbilical hernia under local anaesthesia: tips and tricks
DETRY, Olivier ULg

Conference (2014, December 12)

Despite many studies confirming the feasibility and the interest of local anaesthesia for umbilical repair, its use is not generalized amongst the abdominal surgeons. The advantages of local anaesthesia ... [more ▼]

Despite many studies confirming the feasibility and the interest of local anaesthesia for umbilical repair, its use is not generalized amongst the abdominal surgeons. The advantages of local anaesthesia are indeed clear, including reduced costs, reduced hospital stay and reduced post operative pain. The success of the procedure depends on the skills and the motivation of the surgeon, of the nursing teams, and of the patient him/herself. The Mayo repair is ideally performed under local anaesthesia, but should be proposed to patients suffering from limited umbilical hernia with small defects. Prosthetic repairs might also be proposed under local anaesthesia, but large defects with rectus diastasis might require a full Rives/Stoppa repair in which local anaesthesia could not be sufficient. In obese patients, laparoscopic repair might be beneficial despite higher cost and longer hospital stay. Practically local anaesthesia requires some patience and quiet in the operative room. Operators should be aware that the action of local anaesthesia is delayed after injection. Local anaesthetics should be buffered and at body temperature at time of injection. Local anaesthetics containing Adrenalin allow longer pain control, with limitation of bleeding and less toxicity. Large and brutal movements should be avoided. Ligature and section of parts of greater omentum are feasible under local anaesthesia without patient discomfort. Tension free repair should be favoured, and during Mayo repair, the only painful part of the repair is often the closure of the defect with the different stiches. The surgical and anaesthetic techniques for umbilical hernia repair should be tailored to the specific characteristics of the umbilical hernia and of the patient. There is no method of choice that might fit for every patient. [less ▲]

Detailed reference viewed: 19 (2 ULg)
Peer Reviewed
See detailGenetic structure of fragmented southern populations of African Cape Buffalo (Syncerus caffer caffer) based on microsatellite analysis
Smitz, Nathalie ULg; Cornélis, Daniel; Chardonnet, Philippe et al

Poster (2014, December 12)

Detailed reference viewed: 12 (3 ULg)
Peer Reviewed
See detailThe cerato-mandibular ligament: an innovation for sound production and feeding in damselfishes (Pomacentridae).
Olivier, Damien ULg; Frederich, Bruno ULg; Spanopoulos-Zarco, Milton et al

Conference (2014, December 12)

The success of a taxonomic group can be promoted by a key character that allows the group to interact with its environment in a different way and to potentially occupy new niches. The Pomacentridae ... [more ▼]

The success of a taxonomic group can be promoted by a key character that allows the group to interact with its environment in a different way and to potentially occupy new niches. The Pomacentridae possess a synapomorphic trait, the cerato-mandibular (c-md) ligament, which joins the hyoid bar to the inner part of the lower jaw. It has previously been shown that this ligament is a key trait in communication in damselfishes because it enables them to slam the oral jaws shut causing teeth collision and sound production. This specific behavior of mouth closing could, however, also be used for other tasks, such as feeding. Many territorial damselfishes are referred to as farmers, due to their ability to manage algal crops on which they feed. This study hypothesizes that the c-md ligament provides an advantage for grazing filamentous algae, and should thus be considered a key trait for farming behavior. The kinematic patterns associated with sound production and biting filamentous algae or attached animal prey are all based on the same mechanism and are associated with a slam of the oral jaws. We observed that transection of the c-md ligaments makes the fish unable to perform such actions. This study shows that the c-md ligament is a key trait both for sound production and for grazing activities in damselfishes. The buccal jaw slam enables the fish to perform accurate strikes on small filamentous algae. This kind of bite probably plays a major role in farming activity and allows grazing damselfishes to occupy distinct niches, possibly increasing their competitive evolutionary success. [less ▲]

Detailed reference viewed: 19 (4 ULg)
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See detailNegations in Late Egyptian: the general trends. A functional and typological perspective
Winand, Jean ULg

Conference (2014, December 12)

Detailed reference viewed: 30 (1 ULg)
See detailPolyplex based on polycarbonate polymers for an efficient delivery of HDAC5 and HDAC7 siRNA
Frère, Antoine ULg; Evrard, Brigitte ULg; Mespouille, Laetitia et al

Conference (2014, December 12)

Detailed reference viewed: 10 (3 ULg)
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Peer Reviewed
See detailSound production in piranhas and relatives: preliminary results
Melotte, Geoffrey ULg; Michel, Christian ULg; Parmentier, Eric ULg

Poster (2014, December 12)

Acoustic communication plays an important role in the life of many teleost species where it is mainly involved in agonistic and/or courtship behaviour(s). Despite the large number of species in the family ... [more ▼]

Acoustic communication plays an important role in the life of many teleost species where it is mainly involved in agonistic and/or courtship behaviour(s). Despite the large number of species in the family Serrasalmidae (92 species), sound production has been described only in some of them, particularly in the genera Serrasalmus and Pygocentrus. The aim of this study is to investigate the sound producing abilities of different Serrasalmidae species and to understand the corresponding mechanisms. Two herbivorous species of Serrasalmidae, Piaractus brachypomus and Metynnis lippincottianus, produce sounds composed of a single pulse. The mechanism involved in these species is not yet understood. In contrast, the calls emitted by several species of Serrasalmus and Pygocentrus are harmonic sounds composed of several pulses without inter-pulse interval. Their mechanism results from the forced vibration of the swimbladder following the contraction of sonic muscles that are attached to tendons surrounding ventrally the bladder. Another species, Pygopristis denticulata, is able to produce two types of sounds. The first sound consists of several pulses with irregular pulse period and is likely produced by a sonic muscle inserting on the skull and on the rostral part of the swimbladder. The second sound is multi-pulsed and, contrary to all other sounds described here, possesses a high dominant frequency suggesting a mechanism that does not involve the swimbladder and that remains to be determined. According to these results, Serrasalmidae seems to contain many species able to produce sounds by means of different mechanisms. [less ▲]

Detailed reference viewed: 41 (12 ULg)
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See detailSeasonal sampling and stable isotopes use to delineate seagrass phytodetritus macrofauna trophic ecology: baseline variation or actual diet change?
Remy, François ULg; Mascart, Thibaud ULg; Dauby, Patrick ULg et al

Conference (2014, December 12)

In Mediterranean exported seagrass macrophytodetritus accumulations, a diverse (more than 130 species) and abundant (up to 4900 id.m-2) macrofauna assemblage is found alongside meiofauna, microalgae ... [more ▼]

In Mediterranean exported seagrass macrophytodetritus accumulations, a diverse (more than 130 species) and abundant (up to 4900 id.m-2) macrofauna assemblage is found alongside meiofauna, microalgae, fungi and bacteria. Macrophytodetritus are mainly composed of poorly digestible yet highly colonized material: the dead leaves of the very productive (300 to 2000 g dry wt m-2 yr-1) endemic seagrass Posidonia oceanica. A key role may be played by macrofauna, and more particularly by litter vagile macroinvertebrates (invertebrates > 500µm), in the degradation, enrichment and carbon transfer from P. oceanica to coastal food webs. Indeed, results of gut content observations of the most abundant species show that even if only a few of these species ingest a large proportion of P.oceanica dead leaves fragments, most of the others ingest a small but non-negligible part, suggesting a potential role of the whole community in the mechanical fragmentation of the dead leaves. Mediterranean exported macrophytodetritus accumulations are very dynamic habitats with very variable food availability, quality, and composition. Such an inconstant habitat may result in drastic modifications of the invertebrate community but also of its trophic structure and ecology. To test this hypothesis of influence of pulsed availability, quality and composition of food sources on the vagile macrofauna diet, we took seasonal samples in Calvi Bay (Corsica, 8°45’E; 42°35’N), at two sites between August 2011 and May 2012. Gut content observations and C/N/S stable isotope analysis of bulk tissues were conducted on both the macrofauna and their potential food sources. Significant seasonal and spatial differences of ingestion patterns of the most abundant species were emphasised as were differences of isotopic signatures. “SIAR” Bayesian mixing model and “SIBER” package were used to analyse isotopic data and determine if these differences were due to actual diet modifications or only to baselines isotopic composition variations. [less ▲]

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Peer Reviewed
See detailRapid morphological change of barbels (Cyprinidae) after the dry-up of Sahara
Brahimi, Amina; Tarai, Nacer; Libois, Roland ULg

Poster (2014, December 12)

Detailed reference viewed: 25 (2 ULg)
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See detailSymptômes neurologiques du bord latéral du pied et de la cheville
WANG, François-Charles ULg

Conference (2014, December 12)

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See detailColonization of a new habitat by copepods: An in situ experiment
Mascart, Thibaud ULg; Lepoint, Gilles ULg; Biondo, Renzo ULg et al

Conference (2014, December 12)

Colonization of new habitats by a biological community is conspicuous and this dynamic process is one of the architectural forces of the biogeographical distribution we know today. Within the meiofauna ... [more ▼]

Colonization of new habitats by a biological community is conspicuous and this dynamic process is one of the architectural forces of the biogeographical distribution we know today. Within the meiofauna (<1mm), copepods (Crustacea) have successfully adapted to nearly every ecosystem and heir colonization power of permanent habitats is therefore well-established. However, few studies tackled the colonization of new naturally occurring provisional habitats, which are of ecological interest since they are rich in organic material, structurally complex and devoted of native fauna. Hence, the present study investigated the copepod colonization of provisional macrophytodetritus (mainly composed of senescent leaves and drift macroalgae) accumulated on bare sand patches inside a Mediterranean Posidonia oceanica seagrass meadow. General motive of colonization such as food and shelter are well-defined. However, little is known regarding the mode of the colonization and source pool of the associated colonists. Here, an in situ experiment was deployed in order to understand the mode of copepod’s colonization to fauna deprived macrophytodetritus. The objectives were: (1) assessing the adjacent colonist’s source pool (i.e. sediment, water column or P. oceanica canopy), (2) investigating the speed of settlement and (3) quantifying the species composition of the colonizing copepods. In summary: (1) species from every source pool actively colonized the macrophytodetritus through the water column and through the sediment-macrophytodetritus interface. (2) The initial settlement occurred within the first 24 hours. (3) The species composition showed to be different than the source’s composition. After 24h, the composition was similar to 45% of the P. oceanica, 28% of the water column and 25% of the sediments. After 96h, the composition was similar to 24% of the P. oceanica, 13% of the water column and 10% of the sediments. Indicating an evolution towards a macrophytodetritus copepod specific community composed of a mixture of the adjacent habitats first colonizers. [less ▲]

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See detailSpatial variation in the concentrations of mercury and persistent organic pollutants in free-ranging bottlenose dolphins (Tursiops truncatus) from South Florida
Damseaux, France ULg; Kiszka, Jeremy; Heithaus et al

Poster (2014, December 12)

The bottlenose dolphin (Tursiops truncatus) is an abundant apex predator found in nearshore waters of South Florida, especially in the Lower Florida Keys (Key West) and the coastal waters of Everglades ... [more ▼]

The bottlenose dolphin (Tursiops truncatus) is an abundant apex predator found in nearshore waters of South Florida, especially in the Lower Florida Keys (Key West) and the coastal waters of Everglades National Park (ENP). The objective of this study was to assess variation in contamination levels of total mercury (T-Hg) and persistent organic pollutants (NDL-PCBs, PBDEs, DDT, HCH, HCB, PCDD/Fs and DL-PCBs) in bottlenose dolphins found offshore of the densely populated Key West (n = 27) and from undeveloped ENP (n = 20). T-Hg and POPs were analysed in skin and blubber, respectively, by the mean of Direct Mercury analyser (for THg), GC-ECD (POPs) and GC-HRMS (DLCs). The 7 ICES PCBs were the main compounds found in bottlenose dolphins from Key West (8229 ng.g-1 lipids) and the ENP (2289 ng.g-1 lipids), while the concentrations of PCDD/Fs remained low (Key West: 104 pg.g-1 lipids, ENP: 102 ng.g-1 lipids). POP concentrations were higher in individuals from Key West compared to those from the ENP. However, POPs concentrations in Key West dolphins were lower than those from other locations in Florida and around the world. Unlike organic pollutants, T-Hg concentrations were significantly higher in ENP dolphins (Key West: 2941 ng.g-1 dw versus ENP: 9314 ng.g-1 dw) highlighting the specific cycle of Hg in mangrove ecosystems. To conclude, sources of T-Hg and POPs differed between Key West and ENP as reflected by their concentrations in skin and blubber of free-ranging bottlenose dolphins highlighting their role as sentinels of their environment. [less ▲]

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See detailWhen microplastic is not microplastic: ingestion of artificial cellulose fibers by macrofauna living in seagrass macrophytodetritus
Collard, France ULg; Remy, François ULg; Gilbert, Bernard ULg et al

Poster (2014, December 12)

Vagile macroinvertebrates associated with Posidonia oceanica exported litter were sampled in August 2011, November 2011 and March 2012 in the Calvi Bay (Corsica), near the STARESO oceanographic station ... [more ▼]

Vagile macroinvertebrates associated with Posidonia oceanica exported litter were sampled in August 2011, November 2011 and March 2012 in the Calvi Bay (Corsica), near the STARESO oceanographic station. Contents of digestive tracts were analyzed and fibers of various sizes and colors were found. Fibers were found in 27.6% of the digestive tracts in the nine dominant species. No correlation was found between number of fibers and taxonomic or trophic level. There were no seasonal or spatial preferences and thus we hypothesize that the organisms ingest these fibers randomly throughout the year. Analyses performed with a Raman spectroscope showed that these fibers were composed of cellulose associated with a coloring agent following the fiber color. Red fibers were dyed with the Direct Red 28, blue fibers were dyed with Direct Blue 22. Analyses by a scanning electron microscope (SEM) showed that cellulose fibers had the particular morphology of artificial cellulose fibers called: viscose. Our SEM analyses were compared to literature. This comparison assessed that fibers found in digestive tracts were made of viscose. In a first approach, viscose fibers looked like microplastic fibers because of their color and shape. However, it appeared that these fibers were made of artificial cellulose which is very different than plastic in terms of impacts and fate in the organisms. This study highlights the importance of physico-chemical analyses such as Raman spectroscopy and SEM to certainly identify the composition of particles ingested by organisms. From an ecological point of view, the red coloring agent is known to be carcinogenic in mammals and fish. Consequently, this pollution could provoke an environmental problem for the P. oceanica litter vagile macrofauna. [less ▲]

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See detailAnalphabétisme secondaire, raison cynique et la culture pour tous.
Hamers, Jérémy ULg

Conference (2014, December 12)

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See detailImpact of Climate Change on “Aphid - Natural Enemies” Relationship
Boullis, Antoine ULg; Oostrom, Marjolein; Francis, Frédéric ULg et al

Poster (2014, December 12)

While the effects of global atmospheric changes on vegetation and associated insect populations (bottom-up interactions) are increasingly studied, how these gases affect the interactions between insects ... [more ▼]

While the effects of global atmospheric changes on vegetation and associated insect populations (bottom-up interactions) are increasingly studied, how these gases affect the interactions between insects and their natural enemies (top-down interactions) is less clear. As the efficacy of natural enemies is governed largely by behavioral mechanisms, changes in their prey-seeking behavior or the behavior of insect prey defenses can change the dynamics of insect populations. The impact of increases in atmospheric carbon dioxide concentrations on aphid population dynamic is well documented. However, nothing about their chemical ecology is reported in the literature. Aphids are using many chemical signals to communicate with each other or with their environment. For example aphids produce an alarm pheromone to signal the presence of a natural enemy (such as a predator or a parasitoid) in the colony. Moreover, this pheromone is used by natural enemies as a kairomone to locate aphid prey, and is thus at the center of aphid – natural enemies interactions. In this study, the impact of elevated CO2 concentration on the emission of the alarm pheromone in the aphid A. pisum is studied. Using a zNoseTM (Gas chromatograph enabling the fast analyze of the chemical composition of a sample), the kinetic of the EBF emission in real-time is set up for a single individual predated by a coccinellid predator Harmonia axyridis Pallas. This experimentation is done both for aphids reared under ambient atmospheric conditions and for individuals reared under elevated CO2 concentrations. We present the differences in terms of emission dynamic and discuss the potential of these results in terms of biological control. [less ▲]

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See detailImpact of goldfish on terrestrial and aquatic microhabitat use in the palmate newt
Darnet, Elodie; Winandy, Laurane ULg; Denoël, Mathieu ULg

Poster (2014, December 12)

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See detailCo-evolution of the parasitic fungi Pneumocystis and their Muridae rodent hosts in Southeast Asia
Latinne, Alice ULg; Bezé, François; Morand, Serge et al

Conference (2014, December 12)

Pneumocystis species are opportunistic and airborne-transmitted fungi that infect the lungs of numerous mammalian species. These highly diversified fungi are characterized by strong host specificity ... [more ▼]

Pneumocystis species are opportunistic and airborne-transmitted fungi that infect the lungs of numerous mammalian species. These highly diversified fungi are characterized by strong host specificity, probably associated with co-speciation. In this study, we investigate the Pneumocystis genetic diversity and infection rate in Muridae rodents of Southeast Asia in relation to environmental habitats. A total of 445 wild rodents belonging to 18 Southeast Asian Muridae species were tested for the presence of Pneumocystis in their lungs through PCR amplification of two Pneumocystis mitochondrial genes (mtLSU rRNA and mtSSU rRNA). Pneumocystis DNA was detected in 215 (48.3%) out of these 445 rodents. Eight highly divergent Pneumocystis lineages were retrieved in our phylogenetic tree. Three of these lineages correspond to the described species Pneumocystis murina (infecting Mus species), P. carinii (infecting Rattus species) and P. wakefieldiae (also infecting Rattus species). Three individuals belonging to Rattus norvegicus were found co-infected by both P. carinii and P. wakefieldiae. The five remaining lineages may correspond to several new undescribed Pneumocystis species and infect the lungs of Cannomys (lineage 1), Bandicota (lineage 2), Berylmys (lineage 3), Rattus (lineage 4) and Maxomys, Niviventer and Leopoldamys (lineage 5) Muridae genera. The congruence between phylogenies of Pneumocystis and their rodent hosts has been tested using co-phylogenetic analyses and the number of inferred co-speciation events is significantly greater than expected by chance. Rodent species, age and sex have no influence on the Pneumocystis infection rate among Muridae rodents but individuals trapped close to human settlements in patchy habitat were more likely infected by Pneumocystis parasites. [less ▲]

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See detailA morphospace for the marine angelfishes (Pomacanthidae): patterns of diversity
Frederich, Bruno ULg

Poster (2014, December 12)

The Pomacanthidae (marine angelfishes) is an iconic reef fish family of about 88 species. They have a circum-global distribution on tropical to warm-temperate reefs. Marine angelfishes occupy a diverse ... [more ▼]

The Pomacanthidae (marine angelfishes) is an iconic reef fish family of about 88 species. They have a circum-global distribution on tropical to warm-temperate reefs. Marine angelfishes occupy a diverse range of trophic niches, ranging from spongivory and algivory to zooplanktivory. Previous morpho-functional analysis of this family mainly focused on the head region and gut morphology in a limited number of species. However a morphological study including a large sample of angelfish representatives is currently lacking. Here, I explore the diversity of body morphology in this reef fish group. I collected x-ray images of 228 museum specimens from 71 species and I used landmark-based geometric morphometrics to quantify the overall body shape variation within this family. In a test for interspecific allometry, the linear regression of shape variables onto size (LogTL; TL = total length) was significant (P < 0.001). However, the percentage of explained variance in this model (23%) showed no strong relation between size and body shape. Main shape variation across species was explored using a principal component analysis on shape variables. The two main axes (PC1 and PC2) explained 74% of the total variance of the dataset. Pomacanthus spp., which mainly feed on fixed invertebrates (sponges and tunicates), have deep body with high and angular cephalic profile (lowest values along PC1). Conversely, the zooplanktivorous Genicanthus spp., those have a more pelagic lifestyle, show a slender body with shorter anal fin (highest values along PC1). The pigmy angelfishes from the genus Centropyge, which group different diets (omnivory or algivory), show a more robust and rectangular body shape (high scores along PC2). This work provides the row data for future studies dealing with the mode of phenotypic diversification of Pomacanthidae during evolution. [less ▲]

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See detailStable isotope ratios reveal trophic niche partitioning among hermit crabs from tropical polyspecific seagrass meadows
Michel, Loïc ULg; Frederich, Bruno ULg; Lavitra, Thierry et al

Poster (2014, December 12)

Polyspecific seagrass meadows are ubiquitous features of tropical coastal zones. These ecosystems are of critical ecological importance, and provide a wide range of socio-economical services to local ... [more ▼]

Polyspecific seagrass meadows are ubiquitous features of tropical coastal zones. These ecosystems are of critical ecological importance, and provide a wide range of socio-economical services to local populations. Meadows however undergo multiple threats linked to human activities (increased nutrient input, overfishing, invertebrate overharvesting, etc.). It is currently hard to assess how seagrass meadows could respond to anthropogenic impacts due to poor knowledge of their functional ecology. In an effort to unravel trophic interactions ruling the food webs associated to seagrass beds of the Toliara Great Reef (SW Madagascar), we studied resource segregation between two common Diogenidae hermit crabs (Dardanus scutellatus and Ciliopagurus tricolor) using stable isotope ratios. Interspecific differences were noted in isotopic composition of carbon (δ13C = -12.22 ± 1.73 ‰ for D. scutellatus, δ13C = -14.55 ± 0.73 ‰ for C. tricolor), nitrogen (δ15N = 4.73 ± 0.53 ‰ for D. scutellatus, δ15N = 5.20 ± 0.61 ‰ for C. tricolor) and sulfur (δ34S = 14.08 ± 2.32 ‰ for D. scutellatus, δ34S = 16.73 ± 1.49 ‰ for C. tricolor), suggesting that the two species do not feed on the same items. In addition, SIBER (Stable Isotope Bayesian Ellipses in R) modeling based on C and N data clearly showed that no overlap was present in the core isotopic niches of the two species. It also indicated that the isotopic niche of D. scutellatus was greater than the one of C. tricolor, implying that the former feeds on a greater number of items than the latter. While hermit crabs are generally considered as omnivorous species, this study highlighted differences in the foraging ecology of D. scutellatus and C. tricolor. These differences could help to limit competition for food between these two species, and facilitate their coexistence in Malagasy seagrass beds. [less ▲]

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See detailMaintaining the coexistence of forest species of different shade tolerances with close-to-nature forestry
Ligot, Gauthier ULg; Philippe, Balandier

Conference (2014, December 12)

Continuous-cover forestry has the goal of relying on natural regeneration, and maintaining irregular stand structure and tree species mixture. However, maintaining mixture of species with different shade ... [more ▼]

Continuous-cover forestry has the goal of relying on natural regeneration, and maintaining irregular stand structure and tree species mixture. However, maintaining mixture of species with different shade tolerances appears arduous with such a silvicultural system. Successfully managing irregular and mixed forests, relying on natural processes, requires a strong knowledge of the ecology of natural regeneration. In theory, regeneration dynamics depends upon the amount of transmitted radiation: shade-tolerant species dominate the regeneration under closed canopies whereas less shade-tolerant species dominate the regeneration under partially open canopies. Nevertheless, it explains hardly the difficulties faced by forest managers to maintain the coexistence of species of different shade tolerances. The purpose of this research is to define light requirements of two species with contrasting shade tolerances (Fagus sylvatica L. and Quercus petraea (Matt.) Liebl.) and, next, determining how understory light can be controlled by forest managers. We find that, contrary to our expectations, the shade-tolerant species outgrow the less shade-tolerant species in all light conditions. We next examine the effects of canopy structure and composition on understory light availability with a model of light interception by heterogeneous canopies. Various silvicultural treatments are tested in order to provide favorable understory light conditions for natural regeneration. The results underline that creating favorable understory light conditions for natural regeneration can be achieved with various regeneration treatments. However, the adequate reduction of stand density depends upon the chosen silvicultural strategies. The outcomes of this study highlight that the control of understory light can be insufficient to maintain the coexistence of species of contrasting shade tolerance, and provide guidelines for the management of understory light in heterogeneous forests. [less ▲]

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See detailImpact of aging technique, muscle and previous vacuum storage time on oxidative stability of beef packaged under high-oxygen atmosphere
Didimo Imazaki, Pedro Henrique ULg; Douny, Caroline ULg; Scippo, Marie-Louise ULg et al

Conference (2014, December 11)

The aim of this study was to compare the effect of aging technique (wet-aging vs. carcass-aging), muscle (longissimus dorsi vs. rectus femoris) and previous vacuum storage time on color and lipid ... [more ▼]

The aim of this study was to compare the effect of aging technique (wet-aging vs. carcass-aging), muscle (longissimus dorsi vs. rectus femoris) and previous vacuum storage time on color and lipid stability of beef packaged in high-oxygen atmosphere. After a seven-day wet- or carcass-aging step, longissimus dorsi and rectus femoris muscle cuts from 4 Belgian Blue cows were vacuum packaged and stored at −1 °C for up to 28 days. At different times, part of these samples was repackaged under modified atmosphere – 70 % O2:30 % CO2 –, and stored during 7 days at +4 °C. The following parameters were evaluated at different intervals: color (CIE L*a*b*), metmyoglobin %, lipid oxidation (TBARS), antioxidant enzyme activities (catalase, glutathione peroxidase and superoxide dismutase), alpha-tocopherol and fat content. The sensitivity of modified atmosphere repacked meat cuts to oxidation was influenced by the conditions of the previous aging period (wet > carcass conditions), muscle (rectus femoris > longissimus dorsi) and length of the vacuum storage. Oxidation stability could be associated with catalase activity, and no association could be established with the alpha-tocopherol content. [less ▲]

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See detailLaïcité à la française : de la prétention universaliste à l'obsession identitaire
Jacquemain, Marc ULg

Conference (2014, December 11)

Le mot "laïcité" est revendiqué par des groupes d'extrême-droite ouvertement racistes et conspirationnistes comme "Riposte laïque". L'article montre que le même imaginaire conspirationniste, sous la même ... [more ▼]

Le mot "laïcité" est revendiqué par des groupes d'extrême-droite ouvertement racistes et conspirationnistes comme "Riposte laïque". L'article montre que le même imaginaire conspirationniste, sous la même structure narrative peut être retrouvé sous des formes débarrassée de leur racisme explicite dans des textes considérés comme "mainstream" au sein de la laïcité, en analysant un texte du Rappel. A partir de là, on tente de montrer que cette "dérivation conspirationniste" peut trouver des prises dans des formulations "progressistes" de la laîcité dès lors que ces formulations partent pour point de départ le point de vue à la fois holiste et idéaliste d'un "laos" toujours-dejà-là, comme chez Peña ruiz [less ▲]

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See detailImpact of net metering programs on optimal load management in US residential housing – a case study
Georges, Emeline ULg; Braun, J. E.; Groll, E. et al

in Proceedings of 9th International Conference on System Simulation in Buildings (2014, December 11)

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See detailDe l’immigration marocaine à la présence musulmane
Husson, Jean-François ULg

Conference (2014, December 11)

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See detailIntegrating phylogenetic and environmental niche models to explore speciation mechanisms in the Erythrophleum genus in tropical Africa
Gorel, Anaïs ULg; Fayolle, Adeline ULg; Doucet, Jean-Louis ULg et al

Conference (2014, December 10)

In the context of global climate change, it is of primary importance to understand the species response to climate (habitat tracking or adaptation). In this study we investigated the evolutionary history ... [more ▼]

In the context of global climate change, it is of primary importance to understand the species response to climate (habitat tracking or adaptation). In this study we investigated the evolutionary history of the climatic niche between and within closely related tropical tree species of the Erythrophleum genus (Fabaceae, Caesalpinioideae): E. ivorense, E. suaveolens and E. africanum. Two major hypotheses, the refuge theory and the ecological gradient hypothesis, have been developed to explain the current distribution of tree clades across tropical Africa. To identify the speciation mechanisms, we used a combination of geographic data and environmental factors to quantify the degree of niche conservatism (or divergence). We used two sets of distribution data for the purpose of this study. Species distribution data for the whole of tropical Africa were gathered from herbarium records. Distribution data of the two sister species E. ivorense and E. suaveolens assigned to genetic cluster were available for the lowland tropical forests of western and central Africa. Using a Species Distribution Model (SDM) approach based on MaxEnt algorithm, we tested for the environmental differences (BIOCLIM data) between species and genetic clusters within species. We developed SDMs for each of the three Erythrophleum species (over the whole range) and for each of the five genetic clusters. We quantified the niche overlap using new niche similarity metrics. At species level, the climatic niches differed significantly and overlapped only sligthly, suggesting a parapatric speciation along a climatic gradient. Within the two sister species, the niche of the parapatric central African clusters strongly overlapped, suggesting a secondary contact following the recolonization from different forest refugia. The west African cluster however showed contrasted climatic niches possibly due to either recent (< 100 yrs) climate change in west Africa, or ongoing differentiation on the dry part of the climatic gradient. [less ▲]

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See detailPlaidoyer pour une recherche-compagne
Havelange, Carl ULg

Conference (2014, December 10)

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See detailLa communauté du ressentiment. Analyse d'une posture énonciative
Servais, Christine ULg

Conference (2014, December 10)

Cette communication propose de caractériser la posture énonciative des « nouveaux réactionnaires » en analysant la manière dont ils s’adressent à leurs destinataires en tant que communauté politique. Par ... [more ▼]

Cette communication propose de caractériser la posture énonciative des « nouveaux réactionnaires » en analysant la manière dont ils s’adressent à leurs destinataires en tant que communauté politique. Par conséquent, on n’y conduit pas une simple analyse des représentations, mais une analyse des postures énonciatives en termes d’adresse au récepteur, étant entendu que, en convoquant une référence, le discours convoque également le destinataire dans un monde, auquel et duquel celui-ci est appelé à répondre. C’est à caractériser cet « appel » au récepteur dans le discours des « nouveaux réactionnaires » que cette intervention est consacrée. [less ▲]

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See detailSur quelques conditions médiatiques de la posture néo-réactionnaire
Durand, Pascal ULg

Conference (2014, December 10)

Ceux qu'il est convenu de rassembler sous l'étiquette sans doute trop extensible de « Nouveaux Réactionnaires » appartiennent pour la plupart à un système inséparablement journalistique et éditorial, dans ... [more ▼]

Ceux qu'il est convenu de rassembler sous l'étiquette sans doute trop extensible de « Nouveaux Réactionnaires » appartiennent pour la plupart à un système inséparablement journalistique et éditorial, dans lequel c’est avec une grande symétrie que se répondent et se rencontrent, d’un coté, des « intellectuels médiatiques », auteurs d’essais à rotation rapide leur garantissant de fortes couvertures de presse et un fort taux de présence dans les émissions de radio et de télévision et, de l’autre côté, des journalistes prolongeant leur propre activité par des recueils de chroniques ou des ouvrages sur des questions de politique ou de société. L’intersection de plus en plus forte de l’univers des médias, de l’univers de l’édition et de l’univers intellectuel est d’autant moins étrangère à ce courant de pensée et de discours que certains de ses représentants les plus visibles apparaissent à l’évidence comme les produits de cette intersection même. Les logiques à l’œuvre dans cette intersection sont bien connues : elles vont de l’emprise croissante de la télévision sur le champ journalistique à l’emprise à son tour croissante de ce champ sur l’univers de la production éditoriale et intellectuelle (comme encore sur les formes du débat et de la représentation politiques). L'objet de la présente communication est de mettre en évidence que la nouvelle parole pamphlétaire semble bien avoir trouvé, dans ce nouvel écosystème discursif dominé par le médium télévisuel et notamment les dispositifs du talk show, les conditions idéales à sa propre montée en force et à la propagation de ses effets. [less ▲]

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See detailBias-variance decomposition in Random Forests
Louppe, Gilles ULg

Conference (2014, December 09)

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See detailMoustiques (Diptera : Culicidae) de la région de Ghardaïa et (ré)-émergence des maladies vectorielles
Boukraa, Slimane ULg; Baba Aissa, Nadir; Abdel Azize, Brahim et al

Conference (2014, December 09)

Les maladies vectorielles (ré)-émergentes sont généralement dues à un changement de la distribution des agents infectieux et/ou leurs arthropodes vecteurs. Les changements climatiques, la mondialisation ... [more ▼]

Les maladies vectorielles (ré)-émergentes sont généralement dues à un changement de la distribution des agents infectieux et/ou leurs arthropodes vecteurs. Les changements climatiques, la mondialisation des échanges commerciaux internationaux ainsi que les flux migratoires des populations peuvent affecter cette distribution. De nombreuses espèces de moustiques sont susceptibles de jouer un rôle dans la transmission de divers agents pathogènes responsables des maladies infectieuses humaines et animales comme le paludisme et la fièvre du Nile occidentale. D'autres, outre leur rôle vecteur, sont un véritable fléau par les piqûres douloureuses qu’ils occasionnent et, constituent de ce fait un grand problème de nuisance. L'identification précise et la connaissance de la biodiversité fonctionnelle des vecteurs est un pas essentiel pour la compréhension du risque de (ré)-émergence et la dynamiques des maladies vectorielles. Le présent travail est une étude rétrospective des inventaires des Culicidae réalisés sur le terrain dans la région du M’Zab (Ghardaïa, Algérie) durant les années allant de 2008 à 2012. Les résultats de l’étude morphotaxonomique des Culicidae inventoriés ont montré la présence de dix espèces réparties en cinq genres (Culex, Culiseta, Ochlerotatus, Anopheles et Uranotaenia). Un aperçu sur le rôle vectoriel des espèces signalées dans la région et leur importance au niveau de la santé médicale et vétérinaire sont présentés. Une analyse particulière a été également proposée sur l’épidémie du paludisme de 2013 où 38 cas ont été enregistrés sur l’ensemble de la Wilaya de Ghardaïa. Les espèces potentiellement vectrices d’arbovirus (Virus de Nile occidentale et Virus de la Vallée du Rift) et de protozoaires (Plasmodium spp) qui peuvent causer des problèmes épidémiologique au niveau de la région de Ghardaïa sont Cx. pipiens sl L., 1758, Cx. theileri Theobald, 1903, Ochlerotatus caspius Pallas, 1771, Anopheles sergentii Theobald, 1907, An. dthali Patton, 1905 et An. multicolor Cambouliu, 1902. [less ▲]

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See detailDevelopment and validation of a 3D kinematic-based method for determining gait events during overground walking
Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg; Denoël, Vincent ULg et al

in IEEE International Conference on 3D Imaging (IC3D) (2014, December 09)

A new signal processing algorithm is developed for quantifying heel strike (HS) and toe-off (TO) event times solely from measured heel and toe coordinates during overground walking. It is based on a rough ... [more ▼]

A new signal processing algorithm is developed for quantifying heel strike (HS) and toe-off (TO) event times solely from measured heel and toe coordinates during overground walking. It is based on a rough estimation of relevant local 3D position signals. An original piecewise linear fitting method is applied to these local signals to accurately identify HS and TO times without the need of using arbitrary experimental coefficients. We validated the proposed method with nine healthy subjects and a total of 322 trials. The extracted temporal gait events were compared to reference data obtained from a force plate. HS and TO times were identified with a temporal accuracy ± precision of 0.3 ms ± 7.1 ms, and –2.8 ms ± 7.2 ms in comparison with reference data defined with a force threshold of 10 N. This algorithm improves the accuracy of the HS and TO detection. Furthermore, it can be used to perform stride-by-stride analysis during overground walking with only recorded heel and toe coordinates. [less ▲]

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See detailIdentifying the best technical trading rule: a .632 bootstrap approach.
Hambuckers, julien ULg; Heuchenne, Cédric ULg

Conference (2014, December 07)

In this paper, we estimate the out-of-sample predictive ability of a set of trading rules. Usually, this ability is estimated using a rolling-window sample-splitting scheme, true out-of-sample data being ... [more ▼]

In this paper, we estimate the out-of-sample predictive ability of a set of trading rules. Usually, this ability is estimated using a rolling-window sample-splitting scheme, true out-of-sample data being rarely available. We argue that this method makes a poor use of the available information and creates data mining possibilities. Instead, we introduce an alternative bootstrap approach, based on the .632 bootstrap principle. This method enables to build in-sample and out-of-sample bootstrap data sets that do not overlap and exhibit the same time dependencies. We illustrate our methodology on IBM and Microsoft daily stock prices, where we compare 11 trading rules specifications. For the data sets considered, two different filter rule specifications have the highest out-of-sample mean excess returns. However, all tested rules cannot beat a simple buy-and-hold strategy when trading at a daily frequency. [less ▲]

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See detailEvidence based medicine - Tendon and platelet-rich plasma (PRP)
Kaux, Jean-François ULg

in Annual Congress RSBPRM (2014, December 06)

Platelets have known roles in coagulation, inflammatory processes, and immunity modulation; they also have ‘‘restorative’’ properties. Indeed, during degranulation, platelets release different cytokines ... [more ▼]

Platelets have known roles in coagulation, inflammatory processes, and immunity modulation; they also have ‘‘restorative’’ properties. Indeed, during degranulation, platelets release different cytokines and growth factors (VEGF, PDGF, TGF-B, IGF-I, and HGF) that promote angiogenesis, tissue remodeling (bone, skin, muscle, tendon, etc.), and wound healing. PRP is obtained by centrifuging autologous blood to obtain a concentration of platelets, usually between 3 and 10 times that of whole blood, depending on the isolation method. For this reason, different PRP preparation techniques cannot provide a consistently identical final product, but there is currently no international consensus on this issue. Overall, PRP could be an attractive therapeutic option for treating chronic musculoskeletal conditions, such as tendinopathy or plantar fasciitis. Tendons do not have a high metabolic index. Growth factors released by platelets promote tenocyte proliferation, stimulate angiogenesis and have analgesic properties. Thus it could stimulate and accelerate tissue regeneration in animal models. In addition to PRP, optimal tissue quality requires the application of mechanical loads. PRP should be considered for chronic tendinopathies. Indeed, the goal is to initiate an acute inflammatory reaction that quickly moves on to the proliferative phase that involves collagen synthesis. The latter is necessary for appropriate tendon healing. PRP should therefore not be used for acute tendinitis or tenosynovitis. Even if most of the preclinical studies showed that PRP stimulates the tendon healing process, clinical series remain more controversial. Based on literature and our clinical experience, we suggest some ideas for improving this treatment. Optimization of the technique for collecting the PRP is paramount. Different risk factors must be corrected before infiltration, and chronic tendinopathies must be carefully selected. Finally, post-infiltration rehabilitation remains absolutely necessary. Standardisation of the use of PRP remains necessary in order to optimise the results. [less ▲]

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See detailL'Aurignacien de la grotte Yafteh et son contexte
Otte, Marcel ULg; Flas, Damien ULg; Zwyns, Nicolas et al

Poster (2014, December 06)

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See detailLes ressources génétiques caprines en Algérie
Moula, Nassim ULg; Philippe, François-Xavier ULg; Ait Kaki, Asma et al

Poster (2014, December 06)

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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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