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See detailCHEMOKINE (CC-MOTIF) LIGAND 2 AS A PROGNOSTIC SERUM MARKER IN CANINE IDIOPATHIC PULMONARY FIBROSIS
Roels, Elodie ULg; Holopainen, S.; Teske, Erik ULg et al

Poster (2015, September 11)

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See detailSedimentary development and correlation of long-term off-reef to shallow-water Devonian carbonate records in Europe
Pas, Damien ULg

Doctoral thesis (2015)

The Devonian Period was characterized by extensive shallow-marine regions, with the largest carbonate platform development of the Phanerozoic Eon. The research carried out in this thesis integrates field ... [more ▼]

The Devonian Period was characterized by extensive shallow-marine regions, with the largest carbonate platform development of the Phanerozoic Eon. The research carried out in this thesis integrates field work, petrographic analysis, conodont biostratigraphy, elemental and carbon isotope geochemistry, magnetic susceptibility and magnetic hysteresis measurement. The aim, to better understand and characterize the environmental conditions that led to the development of three of the largest European Devonian carbonate platforms. This multi-disciplinary study also proposes to validate the use of magnetic susceptibility as a reliable tool for palaeoenvironmental reconstruction and long-distance correlation in marine carbonate. Fieldwork was conducted on four key sections of the European Pre-Mesozoic massifs: the Ardennes (La Thure and Fromelennes-Flohimont), the Rheinisches Schiefergebirge (Burgberg) and the Carnic Alps (Freikofel). The large quantity and in-depth analysis of rock samples and thin-sections has demonstrated the fascinating environmental diversity that shaped the carbonate platforms in the Rhenohecynian and Paleotethys oceans towards the mid-late Devonian times. The aforementioned analysis has enabled the development of reconstructed sedimentary models and large-scale shallowing-deepening histories for each section. New and published biostratigraphic data provided reliable age constraints for the foremost environmental changes evident in each of the sections. δ13C results from the Frasnian – Famennian boundary in the Burgberg and Freikofel sections have revealed Kellwasser events in limestone lithologies. Based on the analysis of ±1800 samples, a high-resolution magnetic susceptibility (in) curve for each section has been developed, highlighting the strong link between the in signatures and the syn-sedimentary parameters, such as carbonate productivity/sedimentation rate, water agitation and siliciclastic input. The comparison betweenin and elemental geochemistry datasets has demonstrated the inherent-parallel link existing between the siliciclastic input proxies and the variation in in signature in each of the sections. Magnetic hysteresis measurements have shown that ferromagnetic minerals such as magnetite control the in signal. By comparing our data sets with published data we could confirm that our in signal is remagnetized. However links between siliciclastic input proxies and in, and between in and environmental parameters have proven a relatively good preservation of the primary depositionally-induced in signal. Finally, by integrating complete data and establishing a correlation chart including the four long-term in curves, it is apparent that on a regional scale long-term in trends can be correlated, as long as the evolution of the main depositional setting in the sections studied remains comparable. The significant impact of syn-sedimentary parameters on the final in signature seems to obscure the imprint of parameters driving variations in continental erosion (e.g., climate, sea-level and tectonic variations) and therefore limiting the inter-regional correlations. This collaborative project on time-series analysis of long-term high-resolution in records in the Dinant Syncline has revealed the imprint of astronomical parameters, giving rise to a more accurate estimate of the Givetian Stage’s duration. [less ▲]

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See detailIdentification et caractérisation des progéniteurs pancréatiques et des précurseurs endocrines durant l'embryogenèse chez le poisson-zèbre
Ghaye, Aurélie ULg

Doctoral thesis (2015)

Le diabète survient lorsque le nombre ou la fonction des cellules β, productrices d’insuline est affecté. Le nombre de personnes atteintes par cette maladie croît de manière impressionnante d’année en ... [more ▼]

Le diabète survient lorsque le nombre ou la fonction des cellules β, productrices d’insuline est affecté. Le nombre de personnes atteintes par cette maladie croît de manière impressionnante d’année en année. Bien qu’il puisse être contrôlé par des injections régulières d’insuline, ce traitement est contraignant, coûteux et ne permet pas d’éliminer toute une série d’effets secondaires chez le patient diabétique. Un des challenges à l’heure actuelle est de développer des stratégies qui permettraient de remplacer ces cellules. La régénération in vivo constitue une approche thérapeutique attrayante. Cependant, cette régénération est peu efficace chez les mammifères et un défi majeur consisterait à la stimuler. Contrairement aux mammifères, le poisson-zèbre (Danio rerio), est un modèle de choix pour étudier la régénération puisqu’il possède le remarquable pouvoir de régénérer les cellules β rapidement et efficacement après leur ablation ciblée. Néanmoins, il est important d’identifier et de caractériser les cellules pancréatiques qui donnent naissance aux cellules β afin de connaître l'ensemble des facteurs et voies de signalisation contrôlant leur formation. Le but de mon doctorat s’est inscrit dans cette démarche d’identification et de caractérisation des cellules progénitrices. Pour ce faire, nous avons généré deux lignées transgéniques qui nous ont permis de suivre le destin des cellules exprimant le facteur de transcription Nkx6.1 et Ascl1b. Par des expériences de traçage de lignée, nous avons montré que les cellules Nkx6.1+ marquent des progéniteurs pancréatiques qui donnent naissance à toutes les lignées pancréatiques alors que les cellules Ascl1b marquent des précurseurs endocrines qui ne donnent naissance qu’à la lignée endocrine. Nous avons aussi montré qu’au début du développement pancréatique, les deux facteurs sont exprimés dans les mêmes cellules pancréatiques puis se séparent rapidement. Cette ségrégation n’est pas la conséquence d’une répression mutuelle entre Ascl1b et Nkx6.1 mais est due à un effet opposé de la voie de signalisation Notch qui maintient l’expression de nkx6.1 et réprime l’expression d’ascl1b. [less ▲]

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See detailAls Staat stabilisiert, als Nation gescheitert? Belgien in der Nachkriegszeit (1945-ca. 1950)
Brüll, Christoph ULg

Scientific conference (2015, September 09)

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See detailIconic virtues of diagrams. Peirce and ampliative reasoning
Leclercq, Bruno ULg

Conference (2015, September 08)

In his Critic of pure reason, Immanuel Kant notoriously claimed that, being grounded on the forms of sense intuition, arithmetical and geometrical propositions are both synthetic (i.e. informative) and a ... [more ▼]

In his Critic of pure reason, Immanuel Kant notoriously claimed that, being grounded on the forms of sense intuition, arithmetical and geometrical propositions are both synthetic (i.e. informative) and a priori. Bernard Bolzano, followed in this by the logicist movement (from Gottlob Frege to Rudolf Carnap), answered that the generality and necessity of mathematical propositions and proofs can only be grounded on conceptual analysis. Even though, just like Frege, he is one of the fathers of formal logic, Charles Sanders Peirce provides some semiotic reasons to think that Kant was right: diagrams do convey general meanings and provide some knowledge which is necessary yet non-trivial. Unlike logical analysis, visual presentation of concepts in schemas or diagrams helps to explore concepts by stressing some of their “side” features in such a way that new knowledge is gained: « diagrams evolve what was involved » (CP4/86). This is why, according to Kant’s notion of intuitive construction, mathematical inferences are not merely deductive but are inventive and ampliative. My talk aims at identifying some iconic virtues of diagrams which, according to Peirce, explain their epistemic productivity. A first one lies in the “formal” nature of icons, which allows them to express syntactic relations between descriptive (symbols) and demonstrative (indices) components of structured information. On this respect, even algebraic and ideographic expressions are icons exhibiting a general form – a “rheme” – in which places for indices are filled with variables “x” and “y” meaning “any individual”. For this reason, even though they are singular, diagrams are “abstractions” in the sense that they represent relations rather than their terms. Only with this in prospect can a second, and more studied, feature of diagrams matter, namely their two-dimensionality, which helps to exhibit complex relations that cannot be seen on linear linguistic expressions. Finally, a third feature of diagrams lies in their imaginary rather than referential character. Icons connote without denoting, and therefore they can be informational without this information being limited to singular individuals. Furthermore, this non referential character of icons is what makes them open to virtual exploratory manipulations that allow to consider and investigate possibilities which in turn inform us on not obvious properties of the presently visible configuration. [less ▲]

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See detailDétection automatique de glomérules en pathologie digitale
Marée, Raphaël ULg; Jean-Christophe, Olivo-Marin; Vannary, Meas-Yedid

Scientific conference (2015, September 08)

Dans cet article, nous proposons une méthodologie de détection de glomérules au sein d’images de biopsies rénales. Elle combine des techniques de traitement d’images et d’apprentissage supervisé. Nous ... [more ▼]

Dans cet article, nous proposons une méthodologie de détection de glomérules au sein d’images de biopsies rénales. Elle combine des techniques de traitement d’images et d’apprentissage supervisé. Nous évaluons l’approche sur des images présentant plusieurs sources de variations et montrons que les comptages automatiques sont très bien corrélés avec les comptages des experts [less ▲]

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See detailA stochastic computational multiscale approach; Application to MEMS resonators
Lucas, Vincent ULg; Golinval, Jean-Claude ULg; Paquay, Stéphane et al

in Computer Methods in Applied Mechanics & Engineering (2015), 294

The aim of this work is to develop a stochastic multiscale model for polycrystalline materials, which accounts for the uncertainties in the micro-structure. At the finest scale, we model the micro ... [more ▼]

The aim of this work is to develop a stochastic multiscale model for polycrystalline materials, which accounts for the uncertainties in the micro-structure. At the finest scale, we model the micro-structure using a random Voronoi tessellation, each grain being assigned a random orientation. Then, we apply a computational homogenization procedure on statistical volume elements to obtain a stochastic characterization of the elasticity tensor at the meso-scale. A random field of the meso-scale elasticity tensor can then be generated based on the information obtained from the SVE simulations. Finally, using a stochastic finite element method, these meso-scale uncertainties are propagated to the coarser scale. As an illustration we study the resonance frequencies of MEMS micro-beams made of poly-silicon materials, and we show that the stochastic multiscale approach predicts results in agreement with a Monte Carlo analysis applied directly on the fine finite-element model, i.e. with an explicit discretization of the grains. [less ▲]

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See detailOrganocatalytic promoted coupling of carbon dioxide with epoxides: a rational investigation of the cocatalytic activity of various hydrogen bond donors
Alves, Margot ULg; Grignard, Bruno ULg; Gennen, Sandro ULg et al

in Catalysis Science & Technology (2015), 5(9), 4636-4643

A catalytic platform based on an onium salt used in combination with organic cocatalysts of various structures was developed for the efficient CO2/epoxide coupling under mild conditions. Through detailed ... [more ▼]

A catalytic platform based on an onium salt used in combination with organic cocatalysts of various structures was developed for the efficient CO2/epoxide coupling under mild conditions. Through detailed kinetic studies by in-situ FT-IR spectroscopy, a rational investigation of the efficiency of a series of commercially available hydrogen bond donors co-catalysts was realized and the influence of different parameters such as the pressure, the temperature, the catalyst loading, and the nature of the epoxide on the reaction kinetics was evaluated. Fluorinated alcohols were found to be more efficient than other hydrogen bond donor activators proposed previously in the literature under similar conditions. [less ▲]

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See detailThe changing UV and X-ray properties of the Of?p star CPD -28°2561
Nazé, Yaël ULg; Sundqvist, Jon O.; Fullerton, Alex W. et al

in Monthly Notices of the Royal Astronomical Society (2015), 452

The Of?p star CPD -28°2561 was monitored at high energies with XMM-Newton and HST. In X-rays, this magnetic oblique rotator displays bright and hard emission that varies by ~55 per cent with rotational ... [more ▼]

The Of?p star CPD -28°2561 was monitored at high energies with XMM-Newton and HST. In X-rays, this magnetic oblique rotator displays bright and hard emission that varies by ~55 per cent with rotational phase. These changes occur in phase with optical variations, as expected for magnetically confined winds; there are two maxima and two minima in X-rays during the 73 d rotational period of CPD -28°2561. However, contrary to previously studied cases, no significant hardness variation is detected between minima and maxima, with the exception of the second minimum which is slightly distinct from the first one. In the UV domain, broad-band fluxes remain stable while line profiles display large variations. Stronger absorptions at low velocities are observed when the magnetic equator is seen edge-on, which can be reproduced by a detailed 3D model. However, a difference in absorption at high velocities in the C IV and N V lines is also detected for the two phases where the confined wind is seen nearly pole-on. This suggests the presence of strong asymmetries about the magnetic equator, mostly in the free-flowing wind (rather than in the confined dynamical magnetosphere). [less ▲]

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See detailDroit d'auteur et compétence internationale : de la territorialité à la mode de la Cour de justice
Wautelet, Patrick ULg

in LAMBRECHT, Maxime; Fossoul, Virginie; Delforge, Véronique (Eds.) et al 20 ans de la loi sur le droit d'auteur (2015)

Ce texte fait le point sur la jurisprudence de la Cour de justice relative au contentieux de la contrefaçon du droit d'auteur. Il s'intéresse en particulier à l'application de l'article 7(2) du Règlement ... [more ▼]

Ce texte fait le point sur la jurisprudence de la Cour de justice relative au contentieux de la contrefaçon du droit d'auteur. Il s'intéresse en particulier à l'application de l'article 7(2) du Règlement Bruxelles IIbis à ce contentieux [less ▲]

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See detailBifacial serrated technology in the southern African Still Bay: new data from Sibudu Cave, Kwazulu-Natal
Schmid, Viola; Porraz, Guillaume; Rots, Veerle ULg et al

Conference (2015, September)

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See detailRegional occurence of greenhouses gases in groundwater: Initial results in shallow Belgian aquifers.
Hakoun, Vivien ULg; Gesels, Julie ULg; Tseng, Jean Hsiao-Chun et al

Poster (2015, September)

Currently, the lack of robust, context-distributed subsurface greenhouses gases (GHG) concentrations data is a key bottleneck to reduce the uncertainty range of GHG groundwater input to continental ... [more ▼]

Currently, the lack of robust, context-distributed subsurface greenhouses gases (GHG) concentrations data is a key bottleneck to reduce the uncertainty range of GHG groundwater input to continental surface water bodies such as rivers or lakes estimates. Carbon dioxyde (CO2), methane (CH4) and nitrous oxyde (N2O) are likely to be indirectly transferred to the atmosphere through groundwater discharge into continental surface water bodies. We aim to extend regional-scale estimates of indirect GHG emissions by screening, in numerous hydrogeological (such as alluvial, sandstone, chalk and limestone aquifers) and land use contexts (such as industrial and agricultural), the occurence of these gases. Here, we report and discuss CO2, CH4 and N2O concentrations from an initial survey conducted over selected sites (n= 40) within shallow (0-100 m depth) aquifers in Wallonia (Belgium) for the first time. The preliminary results obtained in this study show that the range of GHG concentrations varies between 5160 and 47544 ppm, 0 and 1064 nmol.L-1, as well as 1 and 5637 nmol.L-1 for the partial pressure of CO2, CH4 and N2O respectively. This new and unique regional dataset provides a first step in developping a refined understanding of favorable contexts for GHG occurence in groundwater which may be used to reduce the uncertainties related to indirect emissions of GHG through groundwater-surface water transfers. [less ▲]

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See detailInsolvabilité européenne et procédures secondaires
Wautelet, Patrick ULg

in Brulard, Yves (Ed.) Règlement 2015/848 relatif aux procédures d'insolvabilité - premier commentaire (2015)

Ce texte tente d'éclairer la portée des dispositions du Règlement N° 2015/848 du 20 mai 2015 relatives aux procédures secondaires : après un bilan sommaire de l'application des dispositions du Règlement ... [more ▼]

Ce texte tente d'éclairer la portée des dispositions du Règlement N° 2015/848 du 20 mai 2015 relatives aux procédures secondaires : après un bilan sommaire de l'application des dispositions du Règlement 1346/2000 relatives aux procédures secondaires, qui s'appuie principalement sur la jurisprudence de la Cour de justice, le texte commente les principales innovations du Règlement révisé. Une attention particulière est accordée à la technique de l'engagement par laquelle le syndic de la procédure principale peut éviter l'ouverture d'une procédure secondaire. [less ▲]

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See detailUncertainty in biology: a computational modeling approach
Geris, Liesbet ULg; Gomez-Cabrero, David

Book published by Springer (2015)

Computational modeling of biomedical processes is gaining more and more weight in the current research into the etiology of biomedical problems and potential treatment strategies. Computational modeling ... [more ▼]

Computational modeling of biomedical processes is gaining more and more weight in the current research into the etiology of biomedical problems and potential treatment strategies. Computational modeling allows to reduce, refine and replace animal experimentation as well as to translate findings obtained in these experiments to the human background. However these biomedical problems are inherently complex with a myriad of influencing factors, which strongly complicates the model building and validation process. This book wants to address four main issues related to the building and validation of computational models of biomedical processes: 1. Modeling establishment under uncertainty 2. Model selection and parameter fitting 3. Sensitivity analysis and model adaptation 4. Model predictions under uncertainty In each of the abovementioned areas, the book discusses a number of key-techniques by means of a general theoretical description followed by one or more practical examples. This book is intended for graduate students and researchers active in the field of computational modeling of biomedical processes who seek to acquaint themselves with the different ways in which to study the parameter space of their model as well as its overall behavior. [less ▲]

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See detailIUVS observations of Nitric Oxide nightglow
Stiepen, Arnaud ULg; The IUVS team

Conference (2015, September)

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See detailContribution of the Finite Volume Point Dilution Method for measurement of groundwater fluxes in a fractured aquifer
Jamin, Pierre ULg; Goderniaux, Pascal; Bour, Olivier et al

Conference (2015, September)

The measurement of groundwater fluxes is the basis of all hydrogeological studies. Groundwater flux calculation with Darcy’s law from piezometric gradient measurements and estimation of hydraulic ... [more ▼]

The measurement of groundwater fluxes is the basis of all hydrogeological studies. Groundwater flux calculation with Darcy’s law from piezometric gradient measurements and estimation of hydraulic conductivity with pumping/slug tests may lead to cumulated errors on spatial variability, in particular in heterogeneous contexts such as fractured aquifers. Alternative methods, such as point dilution tracer tests to obtain a direct measurement of local groundwater fluxes, are promising. In this study classical Point Dilution Method (PDM) and Finite Volume Point Dilution Method (FVPDM) are compared on the fractured crystalline aquifer of Ploemeur, France. The manipulation includes the first use of the FVPDM in a fractured aquifer using a double packer. This configuration limits the vertical extent of the tested zone to target a precise fracture zone of the aquifer. The result of this experiment wasa continuous monitoring of groundwater flux that lasted more than 4 days. Measurements of groundwater flow rate in the fracture (Qt) by PDM only provide good estimates if the mixing volume (Vw) (volume of water in which the tracer is mixed) is known precisely. Conversely, FVPDM allows for an independent estimation of Vw and Qt, leading to better precision in case of complex experimental setup such as this one. The precision of PDM does not depend upon the duration of the experiment while FVPDM may require long experimental duration to guarantee a precise result. Classical PDM should be used to rapidly estimate the groundwater flux using a simple experimental setup. However, FVPDM is a more precise method with great potential for development but it may require a longer experiment duration to achieve high precision if the groundwater flux investigated islow and/or the mixing volume is large. [less ▲]

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See detailDiscovery of Diffure Aurora on Mars
Stiepen, Arnaud ULg; Schneider; Jain et al

Conference (2015, September)

The Imaging Ultraviolet Spectrograph (IUVS, McClintock et al., 2014) onboard the MAVEN spacecraft has discovered diffuse aurora in Mars’ northern hemisphere spanning a wide range of geographic latitudes ... [more ▼]

The Imaging Ultraviolet Spectrograph (IUVS, McClintock et al., 2014) onboard the MAVEN spacecraft has discovered diffuse aurora in Mars’ northern hemisphere spanning a wide range of geographic latitudes and longitudes (Figure 1). This widespread aurora differs from the small auroral patches discovered by the SPICAM instrument onboard the Mars Express spacecraft (Bertaux et al., 2005; Leblanc et al., 2008; Gérard et al., submitted; Soret et al., submitted) restricted to regions of crustal magnetic fields in the southern hemisphere. Furthermore, the northern diffuse aurora appears to peak at altitudes below 100 km, while the crustal field aurora peaked around 120 km. [less ▲]

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See detailFirst Results From MAVEN’s Imaging UV Spectrograph
Schneider; McClintock; Stewart et al

Conference (2015, September)

We report the first results from The Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN) spacecraft orbiting Mars. The instrument is accomplishing its ... [more ▼]

We report the first results from The Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN) spacecraft orbiting Mars. The instrument is accomplishing its goals of characterizing the atmospheric composition and structure, enabling studies of atmospheric escape that will contribute to our understanding of Mars’ atmospheric evolution. In addition, the instrument has made unexpected discoveries concerning meteor showers, aurora and nightglow on Mars. [less ▲]

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