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See detailUnravelling Cemip expression and functions in the auditory portion of the inner ear.
Czajkowski, Amandine ULg; Chariot, Alain ULg; Delacroix, Laurence ULg et al

Poster (2015, May 29)

The inner ear is a complex organ composed of the vestibular system – which is the balancing system – and the cochlea – which is the earing system. The cochlea is a coiled shape organ composed of three ... [more ▼]

The inner ear is a complex organ composed of the vestibular system – which is the balancing system – and the cochlea – which is the earing system. The cochlea is a coiled shape organ composed of three main structures: the spiral ligament sitting on top of the stria vascularis, the organ of Corti with sensory hair cells and supporting cells and the spiral ganglion composed of neurons and glial cells. After an auditory stimulus, the sound wave progresses in the scala media filled with endolymph and induces a stimulation of sensory hair cells. These cells then transmit the information to the spiral ganglion neurons connected to them. Of course, the correct ionic homeostasis of endolymph is required for a good sound wave transmission. This homeostatic function is assured by the stria vascularis and the spiral ligament. The alteration of one of the structures mentioned before induces deafness. Currently, numerous genes have been associated to this kind of hearing loss. In the present work, we focus our attention Cemip – also known as KIAA1199 – that has been associated to human hereditary neurosensory deafness. Indeed, three missense mutations consisting in non-synonymous amino acid changes (R187L, R187H and H783Y) have been associated to this form of deafness. Therefore we would like to understand the role of Cemip in the cochlea. For that we have analysed Cemip mRNA pattern of expression by in situ hybridization at different developmental stages on cochlear sections. It seems Cemip mRNA is not present in the auditory portion of the inner ear at early embryonic stage 14 (E14) while it is largely present at E17 in the spiral ganglion, in supporting cells of the organ of Corti and in the spiral ligament. This expression is maintained post-nattily until P7. At P21 the expression is restricted to the spiral lamina - an osseous structure surrounding the spiral ganglion. Our on going work is aimed at revealing the biological role of Cemip in the cochlea in conditional knock-out mice. [less ▲]

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See detailUne nouvelle cause génétique d'acromégalie
Beckers, Albert ULg

Scientific conference (2015, May 29)

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See detailL'influence des conditions astrophysiques sur la chimie interstellaire
De Becker, Michaël ULg

Learning material (2015)

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See detailA Bayesian statistical model for the Ebola epidemic in Sierra Leone
Frasso, Gianluca ULg; Lambert, Philippe ULg; Bonou, Wilfried ULg

E-print/Working paper (2015)

The 2014 Ebola outbreak in Sierra Leone is analyzed using an extension of the SEIR compartmental model. The unknown parameters of the system of differential equations are estimated by combining data on ... [more ▼]

The 2014 Ebola outbreak in Sierra Leone is analyzed using an extension of the SEIR compartmental model. The unknown parameters of the system of differential equations are estimated by combining data on the number of new (laboratory confirmed) Ebola cases reported by the Ministry of Health and prior distributions for the transition rates elicited using information collected by the WHO Response Team (2014) during the follow-up of specific Ebola cases. The evolution over time of the disease transmission rate is modeled nonparametrically using penalized B-splines. Our framework represents a valuable and robust stochastic tool for the study of an epidemic dynamic from irregular and possibly aggregated case data. Simulations and the analysis of the 2014 Sierra Leone Ebola data highlight the merits of the proposed methodology. [less ▲]

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See detailVégetation aquatique et supra-aquatique des cours d'eau luxembourgeois
Sossey Alaoui, Khadija ULg

Book published by PRESSES ACADÉMIQUES FRANCOPHONES (2015)

La répartition des Macrophytes aquatiques (Phanérogames et Bryophytes) a été étudiée sur l’ensemble des cours d’eau luxembourgeois. Des prospections macrophytiques ont été réalisées pour 340 stations ... [more ▼]

La répartition des Macrophytes aquatiques (Phanérogames et Bryophytes) a été étudiée sur l’ensemble des cours d’eau luxembourgeois. Des prospections macrophytiques ont été réalisées pour 340 stations entre 2000 et 2003. Dans chacune d’entre elles, des paramètres mésologiques ont été mesurés et des analyses physico-chimiques des eaux ont été effectuées dans 63% des stations. La relation macrophytes-habitat a été envisagée selon deux approches : multidimensionnelle d’une part et par des profils écologiques d’autre part. Les principales espèces aquatiques et semi-aquatiques des rivières luxembourgeoises ont été classées en différents groupes par une Analyse Factorielle Multiple (AFM) sur base des descripteurs physico-chimiques et morpho-métriques impliqués dans la dispersion, l’établissement et la persistance des espèces aquatiques. Basée sur l’abondance de ces groupements, une typologie floristique des cours d’eau a conduit à l’individualisation de différents groupes de stations : 1 les têtes de bassins ardennais caractérisées par Chiloscyphus pallescens et C. polyanthos ainsi que par un éclairement faible et un substrat grossier ; 2 les cours principaux de l’Oesling à Ranunculus penicillatus, R. peltatus ; 3 Berula erecta et Veronica beccabunga caractérisent les zones amonts du Gutland dont les eaux montrent des teneurs élevées en nitrates ; 4 les cours principaux lorrains dont les eaux sont plus minéralisés et riches en SO42- sont caractérisés par P. crispus, E. canadensis, P. natans et Z. palustris ; 5 et finalement les zones fortement eutrophisées (rithrons) caractérisées par un grand nombre d’espèces (Potamogeton pectinatus, P. perfoliatus, Sparganium emersum….) et par des critères morpho-métriques très importants (profondeur, éclairement, largeur et température). Des profils écologiques et des cartes de distributions des principales espèces rencontrées (Phanérogames et Bryophytes) nous ont permis de délimiter leurs comportements vis a vis de l’eutrophisation et de la minéralisation. Les différences observées par rapport à la littérature témoignent d’une prolifération des espèces polluo-tolérantes d’une part et d’une pression anthropique importante le long du réseau hydrographique luxembourgeois d’autre part. Une méthode indicielle a été appliquée afin d’évaluer la qualité des rivières sur base des espèces inventoriées. Néanmoins, la faible occurrence des espèces et la non prise en compte des algues ont diminué l’acuité de la méthode. L’importance des formations végétales riveraines au sein des écosystèmes aquatiques et plus particulièrement dans le domaine de la bioindication a été étudiée également. Le pouvoir bioindicateur pour les facteurs acidité, azote, humidité, et lumière (ELLENBERG et al., 1992) a été précisé pour 220 espèces rivulaires inventoriées le long des sites de l’Oesling et du Gutland. Une typologie des biotopes riverains a été dégagée sur base de ces valeurs bioindicatrices. Le déterminisme de la richesse des sols riverains a été envisagé dans sa composante naturelle Oesling-Gutland, ainsi que dans sa composante anthropique. [less ▲]

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See detailDe l’ordre répressif étatique à celui de la Cour pénale internationale : la sensibilité du juge de Strasbourg à la gravité des faits en cause
Deprez, Christophe ULg

Conference (2015, May 29)

Cette présentation PowerPoint a servi de support à une communication orale dans le cadre de l'édition 2015 de la Conférence des Assistants en droit de Belgique (ACCA), organisée le 29 mai 2015 par l ... [more ▼]

Cette présentation PowerPoint a servi de support à une communication orale dans le cadre de l'édition 2015 de la Conférence des Assistants en droit de Belgique (ACCA), organisée le 29 mai 2015 par l'Université catholique de Louvain. [less ▲]

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See detailApproche processuelle de la dépression : Impact de processus psychologiques l'activation ou l'évitement en fonction du sexe
Wagener, Aurélie ULg

Conference (2015, May 29)

La dépression est caractérisée par des symptômes affectifs, cognitifs et somatiques. Elle est également caractérisée par une diminution du niveau d’engagement dans des activités ce qui peut être ... [more ▼]

La dépression est caractérisée par des symptômes affectifs, cognitifs et somatiques. Elle est également caractérisée par une diminution du niveau d’engagement dans des activités ce qui peut être conceptualisé comme de l’évitement comportemental (symptôme comportemental). Il est en effet fréquent que les patients dépressifs s’engagent de moins en moins dans des activités qui leur plaisaient auparavant (voir des amis, etc.) Ce faible niveau d’activités maintient leur humeur dépressive. Cette relation entre dépression et faible niveau d’engagement dans des activités est bien établie dans la littérature scientifique mais les relations entre les processus cognitifs sous-jacents sont encore mal connues. Selon les modèles théoriques de la dépression (Beck, 2008; Lewinsohn, 1985; Watkins, 2009), cinq types de processus psychologiques (PP) sont impliqués dans la symptomatologie dépressive : les pensées négatives répétitives, les stratégies de régulation émotionnelle non-adaptées, un faible niveau de satisfaction environnementale, une image de soi négative et une tendance à l’inhibition. Nous faisons l’hypothèse que ces PP pourraient être les facteurs explicatifs de l’évitement comportemental. Par ailleurs, nous faisons également l’hypothèse que d’autres PP pourraient être considérés comme des facteurs explicatifs de l’activation comportementale : les stratégies de régulation émotionnelle adaptées, un haut niveau de satisfaction environnementale, une image de soi positive, une tendance à l’approche et un concept de soi clair. Ces PP consisteraient en des facteurs protecteurs de la dépression. Dès lors, notre objectif est d’évaluer les liens entre évitement comportemental, activation comportementale et PP. Pour ce faire, en nous basant sur le modèle de Kinderman (2013), nous avons élaboré un modèle conceptualisant l’influence que peuvent avoir les PP précités sur, d’une part, l’évitement comportemental et, d’autre part, l’activation comportementale. De plus, l’étude évalue l’adéquation de ce modèle de façon à comparer les hommes et les femmes. 477 adultes issus de populations cliniques et non-cliniques (119 hommes, 358 femmes, âge moyen = 34,25, ET = 11,85) ont complété une étude en ligne évaluant les PP (pensées négatives répétitives, stratégies de régulation émotionnelles, satisfaction environnementale, image de soi, tendance à l’inhibition/l’approche, clarté du concept de soi), l’évitement comportemental et l’activation comportementale. Différents questionnaires évaluaient chacun de ces PP. Dès lors, des scores factoriels ont été réalisés pour représenter chaque PP. Les résultats préliminaires issus d’analyses factorielles confirmatoires semblent révéler des différences entre les hommes et les femmes. Pour les hommes, une image de soi négative, des stratégies de régulation émotionnelle non-adaptées et un faible niveau de satisfaction environnementale sont liés à l’évitement comportemental alors qu’un haut niveau de satisfaction environnementale et une image de soi positive sont liés à l’activation comportementale. Pour les femmes, un faible niveau de satisfaction environnementale, des stratégies de régulation émotionnelle non-adaptées et des pensées négatives répétitives sont liées à l’évitement comportemental alors qu’un haut niveau de satisfaction environnemental et une image de soi positive sont liées à l’activation comportementale. La collecte des données étant toujours en cours, les résultats globaux seront présentés durant le congrès. Les implications cliniques de ces résultats seront discutées telles que la pertinence de travailler sur le niveau de satisfaction environnementale. [less ▲]

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See detailToward a more precise terminology for impact damage and an improved understanding of hunting weapons: First results from a large scale systematic experiment
Coppe, Justin ULg; Rots, Veerle ULg

Conference (2015, May 29)

Projectile points have recently taken an important place in debates on the complexity of Palaeolithic human behaviour. While the appearance of hunting weapons in the archaeological record was an important ... [more ▼]

Projectile points have recently taken an important place in debates on the complexity of Palaeolithic human behaviour. While the appearance of hunting weapons in the archaeological record was an important element in the past, current discussions focus a lot on the appearance of particular hunting methods. Distinctions are made between simple and complex weaponry, the latter assumed to be linked with modern humans only. While most of the identifications of hunting weapons in the archaeological record rely on the examination of so-called diagnostic impact damage, no reliable reference yet exist for distinguishing between hunting methods. We present the first results of a large-scale and systematic experiment that intends to address hunting weapons in a systematic way. A thorough survey of the literature has highlighted some existing ambiguity in current terminological frameworks for describing impact fractures. Based on our experiments, we propose some attributes that may be relevant for improving these terminologies. Attention will also be devoted to the design and conceptual framework of our experimental program and to some first results concerning the essential variables influencing damage formation. The overall goal is to improve our understanding of the different fracture phenomena and their variability in order to enhance the reliability of the identification of hunting weapons and perhaps of their projecting mode. [less ▲]

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See detailTowards an experiment based protocol for extracting and identifying residues
Cnuts, Dries ULg; Rots, Veerle ULg

Conference (2015, May 29)

Residue analysis has recently become a widely applied method in reconstructing the lifecycle of prehistoric stone tools. The identification of residues is traditionally based on the distinctive ... [more ▼]

Residue analysis has recently become a widely applied method in reconstructing the lifecycle of prehistoric stone tools. The identification of residues is traditionally based on the distinctive morphologies of the residue fragments by means of light microscopy. The majority of residue fragments, however, tend to have an amorphous structure and are therefore not easy to identify. In addition, some residue categories can only be detected by using transmitted light microscopy, which requires the extraction of residues from the tool’s surface. Yet another challenge is to determine whether the residues were deposited on the tool’s surface as a result of use or due to other processes. Here we present the results of an experimental study that addresses these methodological issues. Stone tools from a new experimental reference collection were used to test 6 different analytical methods: the observation of residues on stone tools with incident light microscopy, dry sampling using tweezers and brushes, wet sampling with micropipettes using distilled water and a tri-mixture of acetonitrile, ethanol and water, and extraction with an ultrasonic scaler or bath. The experiments demonstrate that the choice of a particular extraction procedure may influence the amount and types of residues that are extracted. This implies that the analytical method has an impact on the results of a residue analysis. Building on these data, we designed a new protocol, which was subsequently submitted to blind testing in order to test its accuracy and precision. Certain key attributes were also identified that may prove useful in distinguishing between use-related and natural residues. We discuss the importance of adapting analytical protocols to the research question of the study. [less ▲]

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See detailParental and romantic attachments in teen datings : different meanings in boys' and girls' intimacy
Courtain, Audrey ULg; Lepas, Jennifer; Boulard, Aurore ULg et al

Poster (2015, May 28)

First proposing a relational understanding of the child’s very first years, attachment theory has since then been taken into consideration in friendships and romantic relationships. Indeed, the internal ... [more ▼]

First proposing a relational understanding of the child’s very first years, attachment theory has since then been taken into consideration in friendships and romantic relationships. Indeed, the internal working models (IWM) built upon early interactions are to be used on and on in many other situations as guidelines to understand what is going on for the self, this particular other and their specific relationship. Different attachment styles are thus likely to develop: secure or insecure (anxious/preoccupied, avoidant/dismissive, fearful). Considering teen dating, attachment is deeply involved, especially for two reasons: first, a certain questioning, but also re-actualization, of the attachment to parents; second, a new kind of attachment, meaning the one to the romantic partner. These elements lead us to test hypotheses linking attachment to parents and attachment to romantic partners, but also linking these attachments to some teen dating characteristics, such as the age when first dating, the number of love relationships, the longest-lasting love relationship and the fear of intimacy. Our hypothesis was tested among 283 teenagers (mean age = 17.43) with two self-administered questionnaires (the Behavioral Systems Questionnaire and the Fear of Intimacy Scale). Our statistical analyses were made of Pearson Chi², Anova and Post-Hoc Fisher (LSD). We see three types of interesting results. First, there is a significant relationship between attachment (parental and romantic attachments) and the number of love relationships and the fear of intimacy. Second, these relationships are differently established once considered the attachment modalities. Third, gender differences appear, girls looking more influenced by their attachment style than boys. [less ▲]

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See detailThe hot Jupiter WASP-­121 b: A planet heading towards its doom
Delrez, Laetitia ULg

Conference (2015, May 28)

We present here the discovery by the WASP-South survey, in close collaboration with the Euler and TRAPPIST telescopes, of WASP-121 b, a new remarkable short-period transiting hot Jupiter. WASP-121 b is a ... [more ▼]

We present here the discovery by the WASP-South survey, in close collaboration with the Euler and TRAPPIST telescopes, of WASP-121 b, a new remarkable short-period transiting hot Jupiter. WASP-121 b is a very inflated (1.86 Rjup) Jupiter-mass (1.18 Mjup) planet that transits every 1.27 days a bright active F6V star. A notable property of WASP-121b is that its orbital semi-major axis is only 15% larger than its Roche limit, which suggests that the planet might be close to tidal disruption. Furthermore, its large size and extreme irradiation (7.1 10^9 erg s^-1 cm^-2) make it an excellent target for atmospheric studies via secondary eclipse observations. Using the TRAPPIST robotic telescope, we indeed detect its thermal emission in the z’-band at better than ~4sigma, the measured occultation depth being 603+-130 ppm. This measurement is a first for a ground-based 60cm telescope. Finally, from a measurement of the Rossiter-McLaughlin effect with the CORALIE spectrograph, we infer a sky-projected spin-orbit angle of 257.8+-6 deg. This result indicates a significant misalignment between the spin axis of the host star and the orbital plane of the planet, the planet being in a nearly polar orbit. [less ▲]

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See detailQuelle marge de manœuvre pour l'Amérique latine face à la concurrence stratégique entre la Chine et l’Union européenne?
Wintgens, Sophie ULg

Scientific conference (2015, May 28)

Cet article interroge la marge de manœuvre conférée à l’Amérique latine par la concurrence stratégique entre la Chine et l’Union européenne, devenues deux importants partenaires extrarégionaux d’un sous ... [more ▼]

Cet article interroge la marge de manœuvre conférée à l’Amérique latine par la concurrence stratégique entre la Chine et l’Union européenne, devenues deux importants partenaires extrarégionaux d’un sous-continent traditionnellement tourné vers les États-Unis. [less ▲]

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See detailThe neural bases of proactive and reactive control processes in healthy aging
Manard, Marine ULg; François, Sarah ULg; SALMON, Eric ULg et al

Poster (2015, May 28)

Background. Research on cognitive control suggests an age-related decline in proactive control abilities (an anticipatory form of control) whereas reactive control (consecutive to conflict detection ... [more ▼]

Background. Research on cognitive control suggests an age-related decline in proactive control abilities (an anticipatory form of control) whereas reactive control (consecutive to conflict detection) seems to remain intact [1]. As proactive and reactive control abilities were associated to specific brain networks [2], this study investigated age-related effects on the neural substrates associated to each kind of control. Method. A modified form of the Stroop task was administered to 16 young and 16 older adults in an event-related fMRI experiment. In this version of the Stroop task, three different contexts were created: (1) a mostly congruent context (MC, inducing reactive control) with a majority of congruent items, (2) a mostly incongruent context (MI, inducing proactive control) with mainly interfering items, (3) a neutral context (MN) with mainly neutral items. Preprocessing and statistical analyses were performed with SPM8 (p<.001 uncorrected). Results. Behavioral results (p<0.05) indicated faster processing of interferent items in the MI than MC context in young participants only. With regard to neuroimaging data, the comparison of the two groups showed that the processing of interferent items in the MI context is associated to decreased activity in (mainly right-sided) frontal and temporal areas in the older group. On the contrary, in the MC context, increased activity was observed in bilateral frontal areas for older compared to younger participants. Discussion. Behavioral results confirm that older participants have difficulties with the implementation of proactive control that is associated to decreased brain activity (compared to young participants) in areas underlying Stroop performance. However, the recruitment of supplementary frontal areas we observed in the reactive control condition suggests compensation processes. So, aging seems to differentially affect the neural networks associated to the various kinds of cognitive control. [less ▲]

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