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See detailSFX Knowledge Base Advisory Board (KBAB): goals and achievements after one year
Renaville, François ULg; Needleman, Mark

Conference (2014, September 16)

Founded in 2013 as a result of discussions at the 2012 Zurich Conference, the goal of the SFX Knowledge Base Advisory Board (KBAB) is to promote first class quality of the data stored in the SFX Knowledge ... [more ▼]

Founded in 2013 as a result of discussions at the 2012 Zurich Conference, the goal of the SFX Knowledge Base Advisory Board (KBAB) is to promote first class quality of the data stored in the SFX Knowledge Base by reviewing the quality assurance policies and processes together with Ex Libris. During its first year, the group identified several issues in order to improve the CKB quality. They shared them with Ex Libris which agreed to work on or to take a look at some. This session will explain how KBAB has been working, and present some of the issues and the improvements brought by Ex Libris. [less ▲]

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See detailMémoire épisodique et vieillissement normal : L'effet de la manipulation de la facilité de traitement perceptif en reconnaissance
Bastin, Christine ULg; Willems, Sylvie ULg

Poster (2014, September 16)

Etant donné que le vieillissement normal s’accompagne d’un déclin de la recollection tandis que la familiarité reste préservée, les tâches mnésiques facilitant l’utilisation de la familiarité ... [more ▼]

Etant donné que le vieillissement normal s’accompagne d’un déclin de la recollection tandis que la familiarité reste préservée, les tâches mnésiques facilitant l’utilisation de la familiarité permettraient de réduire les différences liées à l’âge en mémoire épisodique. Cette étude a évalué deux questions : 1) L’utilisation de la familiarité en reconnaissance peut-elle être favorisée en augmentant la différence de facilité de traitement perceptif (fluence) entre les items étudiés et les nouveaux items ? ; 2) Cette manipulation permet-elle de réduire l’effet de l’âge ? Deux tâches de reconnaissance ont été proposées à 24 participants jeunes et 24 participants âgés. Dans une tâche « sans recouvrement », les mots cibles et les mots nouveaux ne possédaient aucune lettre commune. L’exposition préalable aux mots cibles induisait donc une fluence sur les mots, mais également sur les lettres de sorte que la différence de fluence devenait un indice saillant et fiable pour distinguer cibles et distracteurs. Dans une tâche « avec recouvrement », les mots cibles et les mots nouveaux contenaient des lettres communes. Les résultats ont répliqué l’effet de l’âge sur la recollection (réponses Remember), avec préservation de la familiarité (réponses Know). Par ailleurs, nous observons 1) une amélioration de la discrimination dans la tâche « sans recouvrement », avec un plus grand nombre de reconnaissances correctes et moins de fausses reconnaissances (les deux basés sur la familiarité). De plus, 2) les différences liées à l’âge dans la capacité à discriminer cibles et distracteurs (reconnaissances correctes - fausses reconnaissances) étaient significativement réduites dans la tâche sans recouvrement par rapport à la tâche avec recouvrement. Ces données suggèrent que minimiser la similarité perceptive entre les mots cibles et les mots distracteurs, et donc augmenter la fluence, permet de réduire les différences liées à l’âge en reconnaissance en facilitant l’utilisation de la familiarité. [less ▲]

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See detailRoughness evolution of sol-gel optical coatings by ion beam sputtering
Gailly, Patrick ULg; Dubreuil, Olivier ULg; Fleury-Frenette, Karl ULg

Poster (2014, September 16)

The surface roughness evolution of two silica-based sol-gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol-gel solutions had been applied on silicon substrates ... [more ▼]

The surface roughness evolution of two silica-based sol-gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol-gel solutions had been applied on silicon substrates using the dip coating technique and then thermally cured to obtain solid thin films. Their thickness had then been controlled over the samples surface using spectroscopic ellipsometry. The surface roughness of the sol-gel films has been measured using both interferometric profilometry and atomic force microscopy at different sputtering depths. Roughness increases significantly faster with sputtering depth in sol-gel layers than on bulk fused silica. Interestingly, the sputtering rates of the sol-gel layers are also observed to be much higher that of bulk fused silica. The development of micron scale holes with relatively stable interstices rules the surface roughness evolution. AFM measurements revealed a regular submicron scale lateral structure which nanometric amplitude is amplified under sputtering. [less ▲]

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See detailNear-death experiences in non-life-threatening events and coma of different etiologies.
Charland-Verville, Vanessa ULg; Jourdan, Jean-Pierre; Thonnard, Marie ULg et al

Poster (2014, September 16)

Near death experiences (NDEs) are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. Empirical studies of NDEs have mostly been ... [more ▼]

Near death experiences (NDEs) are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. Empirical studies of NDEs have mostly been conducted in patients with life threatening situations such as cardiac arrest [1-5] or (albeit more rarely) in patients with severe traumatic brain injury[6]. To the best of our knowledge, no study has formally compared the influence of the cause of coma to the intensity or content of the NDE. Using the Greyson NDE scale [7], the present retrospective study aimed at: (1) exploring the NDE intensity and content in “NDE-like” accounts following non-life-threatening events versus “real NDE” following coma; (2) comparing the “real NDE” characteristics according to the etiology of the brain damage (anoxic, traumatic or other) and; (3) comparing our retrospectively obtained data in anoxic coma to historical previously published prospectively collected post-anoxic NDEs. [less ▲]

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See detailLe modèle de Living Lab au service de l’Agroalimentaire
Goffin, Dorothée ULg

Conference given outside the academic context (2014)

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See detailDevelopping a physically based groundwater vulnerability concept in a DPSIR framework
Beaujean, Jean ULg; Brouyère, Serge ULg; Lemieux, Jean-Michel et al

Conference (2014, September 15)

A general physically based method is presented to assess vulnerability of groundwater to external pressures with respect to quality and/or quantity issues. In the vulnerability assessments, many ... [more ▼]

A general physically based method is presented to assess vulnerability of groundwater to external pressures with respect to quality and/or quantity issues. In the vulnerability assessments, many scientific authors agree nowadays that ‘physically based’ methods must be preferred to traditional approaches based on empirical overlay and index methods where physical attributes are often mixed with implicitly embedded conventional priorities. Results from one or another of these last methods can consequently be very dissimilar for a given case study and decision makers are losing confidence in these tools. A methodology is proposed to reframe the groundwater vulnerability assessment in a Pressure-State-Impact causal chain that is familiar to decision makers. The DPSIR framework, for describing interactions between society and the environment, defines a chain of Drivers that exert Pressures on the State of a given resource, such as water, which then generates an Impact that will require an appropriate Response (Kristensen, 2004). The concept of groundwater vulnerability assessment considered here is based on the calculation of sensitivity coefficients for a user-defined groundwater state for which several physically-based indicators are proposed. These sensitivity coefficients reflect the easiness with which the groundwater state transmits pressures into impacts. They are grouped into a vulnerability matrix of pressures and impacts that quantify vulnerability for every combination of causal links identified in the DPSIR chain. For that reason, the sensitivity coefficients are converted to vulnerability, using the concept of ‘falling below a given threshold’, which is commonly used in socioeconomic sciences (Luers et al. 2003). Outside the careful selection of the sensitivity analysis method that can significantly influence the computational effort (Beaujean et al., 2013), emphasis will be given to the illustration of the general methodology on a simple case (of an alluvial aquifer with concerns related to water supply) demonstrating the potential use of this general and physically based vulnerability assessment method. While the methodology is general, the choice of causal chains has to be made prior to the calculation. The vulnerability is also related to a damaged state and is related to the ‘distance’ between the current state and a given threshold. This choice is arbitrary such that the vulnerability is sensitive to the choice of the threshold. The framework is general and, when applied to water, can include states that are not limited to quality such as, for example, water quantity and availability. [less ▲]

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See detailEtude de la fibrose pulmonaire idiopathique canine: analyse du transcriptome, investigation des voies du TGF beta 1 et recherche de biomarqueurs
Krafft, Emilie ULg

Doctoral thesis (2014)

Canine idiopathic pulmonary fibrosis (cIPF) is a fibrotic disease of the pulmonary parenchyma, mainly seen in the West Highland white terrier. It is characterized by exercise intolerance and cough with a ... [more ▼]

Canine idiopathic pulmonary fibrosis (cIPF) is a fibrotic disease of the pulmonary parenchyma, mainly seen in the West Highland white terrier. It is characterized by exercise intolerance and cough with a progressive deterioration until death from respiratory insufficiency. Clinical, tomodensitometric and histological characteristics of cIPF have been described recently. However, this disease remains largely unknown and the clinicians are dealing with two major challenges: confirmation of the diagnosis, which requires many complementary exams, and absence of effective treatment. Identification of a targeted therapy is difficult without having a good understanding of the mechanisms leading to pulmonary parenchyma fibrosis. A similar disease, the idiopathic pulmonary fibrosis (IPF) is recognized in humans and cIPF might be interesting as a spontaneous model. This project in dogs was undertaken to answer, at least partly, to these challenges. The aims were to elucidate some mechanisms involved in cIPF pathogenesis and to identify biomarkers that could be used in the diagnosis process. The hypotheses were first that analysis of the transcriptome through microarray experiment would identify altered biological functions in cIPF, highlight specific molecules with an altered expression and identify potential biomarkers. Another hypothesis was the transforming growth factor beta 1 (TGFB1) pathways, considered central in the pathogenesis of IPF, would also be modified in cIPF. Finally, ET1, a known biomarker in human IPF, might also be an interesting biomarker in dogs. Gene expression analysis through microarray analysis, combined with the use of IPA, a data analysis program, identified altered biological functions in cIPF: cellular growth and proliferation, developmental processes, cellular movement, cell to cell signaling and interaction and antigen presentation. Some genes highlighted in the microarray experiment were then analyzed individually. Quantitative RT-PCR analysis confirmed an upregulation of the expression of CCL2, CCL7, CXCL14, IL8 and FAP (fibroblast activation protein) as well as a downregulation of the expression of PLUNC (palate, lung and nasal epithelium associated). We then complete the gene expression analysis with a search for potential biomarkers. Thirty-four potential biomarkers were identified with 32 biomarkers potentially measurable in blood (including CCL2, serum amyloid 1, IL8) and 2 biomarkers measurable only in the bronchoalveolar lavage fluid (BALF) (PLUNC and mesothelin). This approach was validated by measurement in serum of one of this biomarker: CCL2. CCL2 serum concentration was higher in affected WHWT compared to healthy WHWT and also higher in dogs with cIPF compared to dogs with chronic bronchitis (CB) or eosinophilic bronchopneumopathy (EBP). Based on serum CCL2 determination, cIPF was diagnosed with a sensibility of 92% and a specificity of 80%. We then studied TGFB1 and part of its storage, activation and signaling pathways. TGFB1 gene expression was not significantly different in the pulmonary parenchyma between affected and control dogs. However, in affected dogs, increased TGFB1 protein levels were seen by immunohistochemistry in fibrotic areas. High expression of bothTGFB1 type I receptor and phosphorylated Smad2/3, markers of an active intracellular TGFB1 signal, were seen in epithelial cells. No difference in expression for the storage proteins LTBP1 and LTBP2 was seen while expression of LTBP4 was significantly decreased in dogs with cIPF. Concerning the proteins involved in TGFB1 activation, gene expression was decreased for integrin subunit β8, increased for thrombospondin-1 and not modified for integrin subunit β6. Expression of Smad 7, involved in intracellular TGFB1 signal inhibition, was not modified. No difference for TGFB1 serum concentration was seen between WHWT with cIPF and healthy WHWT. A multivariate analysis performed on healthy dogs showed no age effect but a significant breed effect with higher levels in predisposed breeds. We evaluated part of the serotonin pathway, as one of its receptor (5HTR2B) was highlighted during the gene expression analysis. Serotonin has also been involved in the pathogenesis of human IPF and described to be of potential use as a biomarker in degenerative mitral valve disease in dogs. Expression of 2 serotonin receptors (5HTR2A and 5HTR2B), evaluated by quantitative RT-PCR in pulmonary tissue, was not different between dogs with cIPF and control dogs while expression of the serotonin transporter (5HTT) was significantly lower in affected dogs. No difference in serotonin serum level was seen between affected and healthy WHWT or between dogs with cIPF, CB or EBP. ET1 was evaluated as a biomarker in serum and BALF. ET1 serum concentration was not different between healthy WHWT and Beagles. Covariance analysis did not reveal any significant age effect. Serum levels were significantly higher in dogs with cIPF compared to dogs with CB or EBP. ROC curve analysis was then used to evaluate its diagnostic performances. The area under the curve was 0,818 with a sensitivity of 91.7% and a specificity of 87.5%. ET1 was also measured in the BALF in a small number of dogs. Its concentration was measurable in all dogs with cIPF while it was below the detection limit in all other dogs tested (healthy and with CB). Even though cIPF and human IPF are not completely identical from clinical, tomodensitometric or histological points of view, these results show that both canine and human diseases share molecular pathways, supporting the idea that cIPF might have an interest as spontaneous model. This work allowed a better understanding of cIPF pathogenesis. Gene expression analysis in the pulmonary parenchyma of affected dogs first identified several altered biological functions that should be analyzed in details in further studies. A more targeted analysis of some genes confirmed an upregulated expression of CCL2, CCL7, CXCL14, IL8 and FAP. Such a positive regulation of the expression of various inflammatory cytokines tends to suggest that inflammation might have a role in cIPF pathogenesis. Some of these cytokines also have profibrotic properties. PLUNC was one of the top down-regulated genes. Roles of the protein are still largely unknown; it might have a role in the inflammatory response and in the innate immunity. Developmental pathways were also altered in cIPF and quantitative RT-PCR confirmed an upregulation of FAP, a protein normally expressed in areas of tissue remodeling during fetal development and also positively regulated in human IPF. This study has shown that there is an active TGFB1 signal in the lungs of dogs with cIPF, especially at the level of the pathological epithelium. TGFB1 storage and activation pathways also seemed to be altered. Elevated TGFB1 circulating levels were found in predisposed breeds, which might explain at least partly their susceptibility for cIPF. Because of these results and its well-known profibrotic properties, we can suggest that TGFB1 is probably involved in cIPF pathogenesis and that modulation of its storage, activation or intracellular signaling might offer potential therapeutic targets. Our preliminary results are not in favor of a significant modification of the serotonin pathways in cIPF, although a decreased expression of 5HTT was seen in affected dogs and might have an impact on the amount of serotonin present locally. However, other studies are needed to conclude. Finally, several potential biomarkers have been identified and some of them were evaluated in details. While serum measurements performed for TGFB1 and serotonin indicated that these molecules have no interest as diagnostic biomarkers, ET1 and CCL2 were identified as interesting candidates with good diagnostic performances. However these results need to be confirmed in an independent validation cohort and the interest of combining both biomarkers should be evaluated. [less ▲]

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

in Science of the Total Environment (2014), 493

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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See detailCrystallization behaviour of binary fat blends containing shea stearin as hard fat
Danthine, Sabine ULg; Delatte, S; Blecker, Christophe ULg et al

Conference (2014, September 15)

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

Conference (2014, September 15)

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

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

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

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

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See detailTranscriptomic characterization of pancreatic duct cells in adult zebrafish
Manfroid, Isabelle ULg

Poster (2014, September 13)

Transcriptomic characterization of pancreatic duct cells in adult zebrafish David Bergemann, Estefañia Tarifeño, Aurélie Ghaye, Marianne Voz, Bernard Peers and Isabelle Manfroid* Zebrafish Development and ... [more ▼]

Transcriptomic characterization of pancreatic duct cells in adult zebrafish David Bergemann, Estefañia Tarifeño, Aurélie Ghaye, Marianne Voz, Bernard Peers and Isabelle Manfroid* Zebrafish Development and Disease Models laboratory, Giga-Research, University of Liège, Belgium Loss of pancreatic beta cells is a hallmark of diabetes. To compensate the resulting deficit of insulin and maintain glucose homeostasis, beta cell replacement by transplantation or regeneration constitute promising strategies. Studies have shown beta cell neogenesis, though by mechanisms not fully understood. These beta cells can derive from replication of pre-existing beta cells1 or from conversion of alpha cells2. Besides these mechanisms, pancreatic ducts have also been hypothesized to contain progenitors/precursors for beta cell regeneration. However, the existence of such adult progenitors remains controversial. Zebrafish has been extensively used as a model for embryogenesis and regeneration. Their beta cells are very similar in development and function to their mammalian counterpart. Indeed, as in mammals, beta cells control glucose homeostasis in adult zebrafish. But, in contrast to mammals, adult zebrafish display the remarkable capacity to spontaneously, efficiently and rapidly regenerate their beta cells after ablation. The origin of these new beta cells is unknown but strong evidences collected in larvae argue in favour of a ductal origin. First, larval pancreatic ducts give rise to endocrine cells in normal condition and in response to the absence of beta cells4. Second, mutant larvae of the ductal marker sox9b harbour defects specifically in duct formation, and beta cell regeneration is impaired5. Here we show that adult pancreatic duct cells can give rise to beta cells. To get insight into this process, we established the transcriptome of adult duct cells by RNA-Seq. Comparison with the transcriptome of the other pancreatic cells identified known and novel ductal markers. Adult duct cells are also characterized by strong expression of embryonic pancreatic progenitor markers (sox9b, pdx1, nkx6.1 and components of the Notch pathway...). Future comparative analyses with ductal cells isolated from zebrafish in different conditions of beta cell (neo)genesis will help identify novel important players in beta cell formation from the ducts as well as regulators of beta cell regeneration. 1. Dor Y et al.(2004) Adult pancreatic beta-cells are formed by self-duplication rather than stem-cell differentiation. Nature 2. Thorel F et al. (2010) Conversion of adult pancreatic alpha-cells to beta-cells after extreme beta-cell loss. Nature 3. Moss JB et al. (2009) Regeneration of the pancreas in adult zebrafish. Diabetes 4. Ninov N et al. (2013) Metabolic regulation of cellular plasticity in the pancreas. Curr. Biol. 5. Manfroid I et al. (2012) Zebrafish sox9b is crucial for hepatopancreatic duct development and pancreatic endocrine cell regeneration. Dev. Biol. [less ▲]

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

Poster (2014, September 12)

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

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

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

Conference (2014, September 12)

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

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

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