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See detailOn-the-fly domain adaptation of binary classifiers
Pierard, Sébastien ULg; Marcos Alvarez, Alejandro ULg; Lejeune, Antoine ULg et al

in 23rd Belgian-Dutch Conference on Machine Learning (BENELEARN) (2014, June 06)

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to ... [more ▼]

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to negative and positive classes are supposed to be mixtures of the source distributions. Moreover, the mixture weights and the priors are only available at runtime. We present a theoretical solution to this problem, and demonstrate the effectiveness of the proposed approach on a real computer vision application. Our theoretical solution is applicable to any classifier approximating Bayes' classifier. [less ▲]

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See detailHydrogéologie et grands travaux du Génie Civil - Hydrogeologie en grote civieltechnische werken
Schroeder, Christian; Huysmans, Marijke; Dassargues, Alain ULg

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen & grondwater in België - Aquifères & eaux souterraines en Belgique (2014)

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See detailComparison between wind speed observed at 100m height and wind speeds simulated by the WRF and MAR models
Doutreloup, Sébastien ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2014, June 06)

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the ... [more ▼]

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the WRF regional model (v.3.4.) forced by ERA-Interim model. Our analysis shows that wind speeds at 100m height simulated by WRF are systematically overestimated compared to wind speeds extracted from wind productions of two wind farms. In order to identify this problem, four comparisons were performed in this contribution. Firstly, we compare WRF model with reanalysis based forcing model. Secondly, we compare two WRF simulations, where one of them has a more precise spatial resolution. Thirdly, we smooth WRF outputs in time (6-hr running mean) in order to study the accuracy of the 30-min variability generated by WRF model. Finally, we comp compare the WRF model with the MAR (v3.3.) regional model using the same forcing at its lateral boundaries. This last one seems to suggest that the MAR model better simulates wind speeds at 10m and at 100m than WRF model and then that wind speed underestimation by WRF is well linked to the WRF physics itself. [less ▲]

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See detailA wavelet-based analysis of surface air temperature variability
Deliège, Adrien ULg; Nicolay, Samuel ULg

Conference (2014, June 06)

We study the Hölder regularity of surface air temperature signals using the wavelet leaders method (WLM). This method has been successfully applied in several domains such as DNA analysis, fully ... [more ▼]

We study the Hölder regularity of surface air temperature signals using the wavelet leaders method (WLM). This method has been successfully applied in several domains such as DNA analysis, fully developped turbulence analysis, internet data traffic analysis,... to name just a few, and we now use it in climatology. We first define the notions of Hölder exponent, monofractal functions and spectrum of singularities before explaining the WLM. Then we use it to study surface air temperature signals from weather stations spread across Western and Eastern Europe and show that they are monofractal, i.e. their irregularity (in the sense of variability) is regular. After, we show that the stations can be classified according to their Hölder exponent and that this classification matches with the worldwide used Köppen-Geiger climate classification. A blind test is performed in order to confirm the results, which can be partly explained by the influence of the North Atlantic Oscillation. Our results can be helpful to test the accuracy of current climatic models. [less ▲]

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See detailAquifères et Eaux Souterraines en Belgique - Watervoerende Lagen en Grondwater in Belgïe
Dassargues, Alain ULg; Walraevens, Kristine

Book published by Academia Press (2014)

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See detailIntroduction générale et description du contexte hydrogéologique en Belgique - Algemene inleiding en beschrijving van de hydrogeologische context in Belgïe
Walraevens, Kristine; Biron, Jean-Paul; Dassargues, Alain ULg

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen & grondwater in België - Aquifères & eaux souterraines en Belgique (2014)

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See detailGraviers de la Meuse (alluvions modernes et anciennes) en Wallonie
Dassargues, Alain ULg; Wildemeersch, Samuel ULg; Rentier, Céline

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen & grondwater in België - Aquifères & eaux souterraines en Belgique (2014)

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See detailGéothermie de très basse température
Dassargues, Alain ULg; Wildemeersch, Samuel ULg

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen & grondwater in België - Aquifères & eaux souterraines en Belgique (2014)

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See detailConfidence levels for the cycles found in climatic data
Mabille, Georges ULg

Scientific conference (2014, June 06)

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See detailRemontées des nappes dans les anciens travaux miniers et activités de démergement - Modélisation hydrogéologique spécifique et exemple de la zone minière de Cheratte
Dassargues, Alain ULg; Wildemeersch, Samuel ULg; Orban, Philippe ULg et al

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen & grondwater in Belgïe – Aquifères & eaux souterraines en Belgique (2014)

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See detailEvaluation des états de conscience altérée en IRM multimodale
TSHIBANDA, Luaba ULg

Report (2014)

Notre travail s’articule autour de deux axes. D’une part nous participons aux travaux de recherches des membres du ComaScienceGroup utilisant les données de Tenseur de diffusion et de fMRI que nous ... [more ▼]

Notre travail s’articule autour de deux axes. D’une part nous participons aux travaux de recherches des membres du ComaScienceGroup utilisant les données de Tenseur de diffusion et de fMRI que nous acquérons en IRM 3 Tesla et d’autre part nous procédons à l’évaluation de l’intérêt de la spectroscopie protonique dans le bilan des états de conscience altérée par rapport au gold standard qu'est le PETScan FDG. [less ▲]

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See detailAquifère crayeux de Hesbaye
Orban, Philippe ULg; Brouyère, Serge ULg; Compère, Jean-michel et al

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen en grondwater in Belgïe - Aquifères et eaux souterraines en Belgique (2014)

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See detailRole of transcription factor sox4b in the differentiation of pituitary cells in zebrafish.
Quiroz O' Donova, Yobhana ULg

Doctoral thesis (2014)

The pituitary is a complex gland comprising different cell types each secreting specific hormones. The extensive network of signaling molecules and transcription factors required for determination and ... [more ▼]

The pituitary is a complex gland comprising different cell types each secreting specific hormones. The extensive network of signaling molecules and transcription factors required for determination and terminal differentiation of specific cell types is still not fully understood. The SRY-like HMG-box (SOX) transcription factor Sox4 plays important roles in many developmental processes and has two homologs in zebrafish, Sox4a and Sox4b. We show that the sox4b gene is expressed in the pituitary anlagen starting at 24hpf and later in the entire head region including the pituitary. At 48hpf, sox4b mRNA colocalizes with that for thyroid stimulating hormone (tsh), glycoprotein subunit  (gsu) and the Zn finger transcription factor Gata2a. Loss of Sox4b function, using morpholino knock-down or expression of a dominant negative Sox4 mutant, leads to a drastic decrease in tsh and gsu expression and reduced levels of gh, while other anterior pituitary gland markers including prl, slβ, pomc and lim3 are not affected. Sox4b is also required for expression of gata2a in the pituitary. Knockdown of gata2a leads to decreased tsh and gsu expression at 48hpf, similar to sox4b morphants. Injection of gata2a mRNA into sox4b morphants rescued tsh and gsu expression in thyrotrope cells. Finally, sox4b or gata2a knockdown causes a significant decrease of gonadotropin expression (lhβ and fshβ) at 4dpf. In summary, our results indicate that Sox4b is expressed in zebrafish during pituitary development and plays a crucial role in the differentiation of thyrotrope and gonadotrope cells through induction of gata2a expression in the developing pituitary. [less ▲]

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See detailLa psychopathologie à la lumière des histoires de vie : Etude de la fonction narrative d’adolescents obèses et dépressifs.
Jadin, Aurore ULg; Gauthier, Jean-Marie ULg; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-Actes des 12èmes journées internationales d'analyse statistique de données textuelles (2014, June 05)

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these ... [more ▼]

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these youngs (High Authority of Health, 2011; Nietsen and Bruwier, 2007). The literature mentions depression as a pathology associated with obesity. Some researchers consider obesity as a cause of depressive symptoms while others researchers see depression like a risk factor for excessive weight gain (Blaine, 2008). Depression in adolescence has been the subject of epidemiological studies for some years. In adolescents, the prevalence rates vary from 5 to 7 % for major depressive episode (MDE) with a prevalence of 2 girls for one boy (Alvin and Marcelli, 2005). The specific symptoms of depressed mood are present in 30-40 % of schooled adolescents (Boulard et al., 2012). During adolescence, the individual acquires the ability to link the various elements of one’s life and build a coherent life story. The adolescent will write one’s story in a personal context. According to Habermas et al. (2008), both the form and the content of life stories show how the individual integrates the lived experiences in a coherent whole. Based on the statistical analysis of textual data, we compared the life stories of 28 obese adolescents, depressed schooled adolescents, depressed hospitalized adolescents and control ones. The first results show specific structures and particular contents depending on these groups. The use of pronouns, temporal markers and the reported events differ by groups. Beyond clinical results, this research also highlights the interest of statistical analysis of textual data (ADT) to improve the understanding of adolescent’s psychopathology. [less ▲]

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See detailMALDI Mass Spectrometry Imaging: a new tool to decipher the antibiome of Bacillus amyloliquefaciens
Debois, Delphine ULg; Jourdan, Emmanuel; Cawoy, Hélène et al

Conference (2014, June 05)

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known ... [more ▼]

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known to exert different actions on the wellness of the producing strain such as fungitoxicity (iturin, fengycin) or motility, root colonization and immune stimulating agent (surfactin). Nevertheless, few is reported about the actual antibiome secreted in situ by Bacillus cells during confrontation with phytopathogens or plant root colonization. We developed a method mimicking the conditions prevailing in the rhizosphere and, taking advantage of the versatility of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging, we were able to localize and identify antibiotics produced in situ by bacterial cells. First, we applied this new methodology to bioassays in which Bacillus amyloliquefaciens 98S were grown together with Fusarium oxysporum, with the aim of deciphering the role of the different LP families during the phytopathogen growth inhibition. Our results showed that the three LP families were readily produced in different proportions. Especially, images of surfactins, iturins and fengycins demonstrated that iturins are the antibiotic family actually involved in the antagonism against Fusarium oxysporum. In a second approach, we used a “in planta” model in which Bacillus amyloliquefaciens S499 was simultaneously grown with Tomato and Arabidopsis thaliana roots. Imaging results, obtained during a time course analysis, showed that surfactin is always the major lipopeptide detected. In further experiments involving a refined time-window, we observed that surfactin is actually produced as soon as 24h post inoculation. These results were the starting point of a wider study showing that the early accumulation of surfactin is a complex phenomenon involving, among other mechanisms, cell-well components recognition by bacteria, and that this interaction is a win-win association for both plant and bacterial cells. [less ▲]

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See detailWarum sollen wir uns an den Ersten Weltkrieg erinnern?
Brüll, Christoph ULg

Conference given outside the academic context (2014)

Die Erinnerung an den Ersten Weltkrieg ist derzeit allgegenwärtig. Kaum ein Tag vergeht, ohne dass die Medien über den „Großen Krieg“ berichten. Die Erinnerung an „1914-1918“ scheint Pflichtprogramm für ... [more ▼]

Die Erinnerung an den Ersten Weltkrieg ist derzeit allgegenwärtig. Kaum ein Tag vergeht, ohne dass die Medien über den „Großen Krieg“ berichten. Die Erinnerung an „1914-1918“ scheint Pflichtprogramm für die Gesellschaft des Jahres 2014. Doch warum ist dies so? Was kann uns ein 100 Jahre zurückliegendes Ereignis heute noch sagen? Der Vortrag fragt nach Erklärung für diese starke Präsenz der Vergangenheit in der Gegenwart. Es reicht dabei nicht zu sagen, dass man aus der Geschichte lernen will. Die Beziehungen zwischen Geschichte und Erinnerung am Beispiel des Ersten Weltkriegs sind überaus vielschichtig und haben Folgen für die Gegenwart, derer wir uns oft gar nicht bewusst sind. An den Vortrag schließt eine Diskussion mit dem Publikum an. [less ▲]

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See detailLes médiateurs scolaires en action : des discours aux pratiques
Dethier, Baptiste ULg

Conference (2014, June 05)

En 1993, dans un contexte marqué les questions d’insécurité, de violence scolaire, de crise de confiance envers les institutions ou encore de décrochage scolaire, 28 médiateurs sont engagés dans autant ... [more ▼]

En 1993, dans un contexte marqué les questions d’insécurité, de violence scolaire, de crise de confiance envers les institutions ou encore de décrochage scolaire, 28 médiateurs sont engagés dans autant d’établissements scolaires aux publics défavorisés de la région bruxelloise. Ce projet pilote, voyant le jour sous la houlette du Ministère de l’enseignement, ne sera institutionnalisé qu’en 1998 dans un décret créant le Service de Médiation Scolaire, divisé en deux entités : 56 médiateurs internes à Bruxelles et 30 médiateurs externes (répartis par zones couvrant plusieurs établissements) en Wallonie. Par ailleurs, d’autres niveaux de pouvoir (communes, diocèses, écoles) créaient également, localement, leurs propres fonctions de médiateur scolaire. Actuellement, on en dénombre environ 120 en Belgique francophone. Ce nouvel acteur, bien que peu étudié, incarnerait un nouveau mode de régulation sociale (Bonafé-Schmitt, 1996) remettant en question les équilibres historiques du système scolaire (Verhoeven, 1997). En effet, il se présente comme un tiers neutre et indépendant de l’établissement, permettant ainsi la création d’un espace où peuvent se résoudre différents problèmes concernant les personnes demandeuses, qu’elles soient élèves, membres du personnel scolaire ou encore parents. Dans un premier temps, notre attention se porte sur l’ensemble des acteurs portant le nom de médiateurs scolaires (Kuty et al., 2012). Au sein d’un cadre légal ne définissant que vaguement leur fonction, ces derniers sont néanmoins globalement chargés de prévenir la violence et le décrochage scolaires et de favoriser, conserver ou rétablir le climat de confiance entre élèves, écoles et familles. À partir de là, ils ont progressivement construit leurs propres pratiques et leur identité, cherchant par là à trouver et à consolider leur place au sein d’un milieu scolaire déjà marqué par la présence de multiples acteurs. Dans un second temps, des études de cas approfondies dans six établissements d’enseignement secondaire permettent de constater que les médiateurs ne disposaient pas du monopole de la médiation (Dubois et Dethier, 2013), concept polysémique auquel de nombreux acteurs se réfèrent pour qualifier certains aspects de leur travail quotidien. En outre, le recours à la médiation ou aux médiateurs ne se révèle être qu’une solution parmi d’autres pour faire face aux différents problèmes rencontrés par les acteurs : violence, décrochage, absentéisme, échec scolaire, conflits, problèmes socio-économiques… Ces constats exigent une étude empirique approfondie du travail concret réalisé par les médiateurs scolaires, une étude attentive à leurs discours mais aussi à l’observation de leurs pratiques et interactions directes avec les différents acteurs scolaires. Les résultats de cette étude font l’objet de cette communication. Cette contribution se base sur un corpus composé de onze entretiens individuels, trois focus groups et trois périodes d’observation non participante auprès de médiateurs belges francophones membres d’un même service. Ces derniers revendiquent une posture de tiers neutre et indépendant dans l’école, ainsi que des principes basés sur le non-jugement, la confidentialité, l’accueil inconditionnel de la demande ou encore la non-expertise. Il s’agira par conséquent de rendre compte de la manière dont ces médiateurs traduisent leurs discours en pratiques au quotidien. [less ▲]

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See detailBiorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes
Tarayre, Cédric ULg; Fischer, Christophe ULg; De Clercq, Lies et al

Conference (2014, June 05)

At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs ... [more ▼]

At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs). Currently, sewage sludge, for example is usually used as a fertilizer in agriculture, in energy production or in the field of construction. Ashes originating from sludge incineration contain heavy metals and minerals in large quantities. Manure is mainly used in agriculture, although considerable amounts of nutrients are lost and cause pollution. Digestate is also used in agriculture, but other alternatives have been proposed, such as the energetic valorization. Better valorization of these wastes in agriculture (or other sectors) is however largely constrained by a multitude of legal requirements. An important problematic point is the concentration in MTEs that is found in those wastes. Consequently, recovery of nutrients and MTEsmay be a key solution for optimal valorization of wastes. Many unit operations used in the field of chemical and biochemical engineering (mechanical operations on fluids, solids, mass and heat transfers, chemical reactions, etc.) could be used in order to achieve an efficient recovery yield of nutrients and trace elements. The aim of the BioRefine Project is to make an inventory of all recovery techniques of nutrients and MTEs in five countries: Belgium, France, Germany, United Kingdom and The Netherlands. Pilot plants will also be tested to assess the efficiency of new treatment techniques after which the most efficient processes will be chosen to be applied on a larger scale. In addition, the collected data will be used to propose exploitation scenarios taking into account legal constraints and optimized logistics.This work is supported through an INTERREG IVB NWE programme(ref. 320J-BIOREFINE). [less ▲]

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