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See detailIdentification et analyse fonctionnelle de nouveaux variants d’épissage du CD46 des bovidés, le (co)-récepteur du virus BVD/MD
Alzamel, Nidal ULg

Doctoral thesis (2017)

The pestivirus bovine viral diarrhea virus (BVDV) is known to bind to the CD46 molecule, which subsequently promotes entry of the virus. Mapping of the BVD-virion-binding site has shown that two peptides ... [more ▼]

The pestivirus bovine viral diarrhea virus (BVDV) is known to bind to the CD46 molecule, which subsequently promotes entry of the virus. Mapping of the BVD-virion-binding site has shown that two peptides, 66EQIV69 and 82GQVLAL87, located on antiparallel beta sheets in the most distal complement control protein module (CCP1), provide the attachment platform. In the present study, we reveal new CD46-encoding transcripts that are predicted to encode CCP1-containing soluble forms. Further, we show that the serum of most adult cattle contains soluble CD46 (sCD46) and that a recombinant soluble isoform neutralizes BVDV infectivity in an in vitro assay. We have then established an ELISA for determination of plasma sCD46 in a large cohort of animals. Overall, serum sCD46 amounts to 8 ± 18 ng/mL (mean ± SD, n = 543), with a IC [95-105] ranging from 6,4 to 9,8 ng/mL and extreme values between 0 and 178 ng/mL. We found that sCD46 is not detectable in fetal and neonatal sera and that its plasma concentration increases progressively up to adulthood. We also detected high- and low-sCD46 performers and show that this phenotype does not depend of environment. As modern rearing techniques make it possible to disseminate genetically-determined phenotypes very quickly in a population, a large-scale study examining whether high-sCD46 animals provide epidemiological protection against BVDV infection and transmission should be undertaken [less ▲]

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See detailAn update on ozone profile trends for the period 2000 to 2016
Steinbrecht, Wolfgang; Froidevaux, Lucien; Fuller, Ryan et al

in Atmospheric Chemistry and Physics (2017), 17(17), 10675-10690

Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data by four techniques at stations of the Network for the Detection of Atmospheric ... [more ▼]

Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data by four techniques at stations of the Network for the Detection of Atmospheric Composition Change indicate significant ozone increases in the upper stratosphere, between 35 and 48 km altitude (5 and 1 hPa). Near 2 hPa (42 km), ozone has been increasing by about 1.5 % per decade in the tropics (20°S to 20°N), and by 2 to 2.5 % per decade in the 35° to 60° latitude bands of both hemispheres. At levels below 35 km (5 hPa), 2000 to 2016 ozone trends are smaller and not statistically significant. The observed trend profiles are consistent with expectations from chemistry climate model simulations. Using three to four more years of observations and updated data sets, this study confirms positive trends of upper stratospheric ozone already reported, e.g., in the WMO/UNEP Ozone Assessment 2014, or by Harris et al. (2015). The additional years, and the fact that nearly all individual data sets indicate these increases, give enhanced confidence. Nevertheless, a thorough analysis of possible drifts and differences between various data sources is still required, as is a detailed attribution of the observed increases to declining ozone depleting substances and to stratospheric cooling. Ongoing quality observations from multiple independent platforms are key for verifying that recovery of the ozone layer continues as expected. [less ▲]

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See detailContributions to deep reinforcement learning and its applications in smartgrids
François-Lavet, Vincent ULg

Doctoral thesis (2017)

Reinforcement learning and its extension with deep learning have led to a field of research called deep reinforcement learning. Applications of that research have recently shown the possibility to solve ... [more ▼]

Reinforcement learning and its extension with deep learning have led to a field of research called deep reinforcement learning. Applications of that research have recently shown the possibility to solve complex decision-making tasks that were previously believed extremely difficult for a computer. Yet, deep reinforcement learning requires caution and understanding of its inner mechanisms in order to be applied successfully in the different settings. As an introduction, we provide a general overview of the field of deep reinforcement learning. In the first part of this thesis, we provide an analysis of reinforcement learning in the particular setting of a limited amount of data and in the general context of partial observability. In this setting, we focus on the tradeoff between asymptotic bias (suboptimality with unlimited data) and overfitting (additional suboptimality due to limited data), and theoretically show that while potentially increasing the asymptotic bias, a smaller state representation decreases the risk of overfitting. An original theoretical contribution relies on expressing the quality of a state representation by bounding $L_1$ error terms of the associated belief states. We also discuss and empirically illustrate the role of other parameters to optimize the bias-overfitting tradeoff: the function approximator (in particular deep learning) and the discount factor. In addition, we investigate the specific case of the discount factor in the deep reinforcement learning setting case where additional data can be gathered through learning. In the second part of this thesis, we focus on a smartgrids application that falls in the context of a partially observable problem and where a limited amount of data is available (as studied in the first part of the thesis). We consider the case of microgrids featuring photovoltaic panels (PV) associated with both long-term (hydrogen) and short-term (batteries) storage devices. We propose a novel formalization of the problem of building and operating microgrids interacting with their surrounding environment. In the deterministic assumption, we show how to optimally operate and size microgrids using linear programming techniques. We then show how to use deep reinforcement learning to solve the operation of microgrids under uncertainty where, at every time-step, the uncertainty comes from the lack of knowledge about future electricity consumption and weather dependent PV production. [less ▲]

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See detailDiscours en hommage à François Bovesse
Behrendt, Christian ULg

Speech/Talk (2017)

Discours d'Hommage prononcé le 11 septembre 2017 au Palais provincial de Namur

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See detailA tiny magic drawing board to track the penetration of magnetic flux in superconductors
Silhanek, Alejandro ULg

Conference (2017, September 11)

Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit ... [more ▼]

Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit cards and computer hard drives. Here we experimentally show that a similar principle can be applied for imprinting the trajectory of quantum units of flux (vortices), travelling in a superconducting film (Nb), into a soft magnetic layer of permalloy (Py). In full analogy with the magnetic drawing board, vortices act as tiny magnetic scribers leaving a wake of polarized magnetic media in the Py board. The mutual interaction between superconducting vortices and ferromagnetic domains has been investigated by the magneto-optical imaging technique. For thick Py layers, the stripe magnetic domain pattern guides both the smooth magnetic flux penetration as well as the abrupt vortex avalanches in the Nb film. It is however in thin Py layers without stripe domains where superconducting vortices leave the clearest imprints of locally polarized magnetic moment along their paths. In all cases, we observe that the flux is delayed at the border of the magnetic layer. Our findings open the quest for optimizing magnetic recording of superconducting vortex trajectories. [less ▲]

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See detailPreliminary Phytochemical Content and Antidiabetic Potential Investigations of Panda oleosa (Pierre) Used in Kisangani Areas
Katemo Muhoya, Frédéric; Kadima Ntokamunda, Justin; Njakarinala Ranarivelo et al

in American Journal of Analytical Chemistry (2017), 8

Panda oleosa Pierre (POP), a tropical plant tree, has been used in traditional medicine in Kisangani city and around to treat various diseases including diabètes and HIV/AIDs. This study aims to evaluate ... [more ▼]

Panda oleosa Pierre (POP), a tropical plant tree, has been used in traditional medicine in Kisangani city and around to treat various diseases including diabètes and HIV/AIDs. This study aims to evaluate the chemical composition of POP extracts while setting up chromatographic fingerprints for their quality control, and the anti-hyperglycemic potential of trunk bark aqueous extracts of POP. Common chemical reactions were used for identification of main secondary metabolic groups. Thin layer chromatography was used to set up several chromatographic fingerprints of water and alcoholic extracts while evaluating chemical composition. Oral glucose tolerance test served to induce hyperglycemia in a rabbit model. The extracts were given as 25 mg/kg, 50 mg/kg, and 100 mg/kg body weight, 30 minutes before loading animals with glucose 4 g/kg. Blood samples were collected at various times: just before extracts (T-30), before (T0) and after glucose load (T30, T60, T120, and T180). Blood glucose levels were measured with One Touch Glucometer. The identification tests revealed the presence of saponins (3.58%), tannins (5%); alkaloids, quinones, flavonoids, and terpenes sterols could not be formerly detected by the reagents used. Interesting chromatographic spots were observed whose behaviors are of catechic tannin proanthocyanes. The extract significantly reduced glucose levels in dose dependent manner as compared to control and glibenclamide reference groups. The average of mean percentage of reduction in glucose level at T120 with the extract 100 mg/kg was close to that of glibenclamide 0.25 mg/kg (49% and 40.2%). These findings back the traditional use of the plant to treat diabetic patients and constitute a foundation for an extensive study to find a new antidiabetic phythomedicine. [less ▲]

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See detailNos cours d'eau, une source d'énergie renouvelable passée, présente et future
Erpicum, Sébastien ULg

Conference given outside the academic context (2017)

L’exploitation de l’énergie hydraulique, verte & renouvelable, a façonné au fil des siècles nombre de nos cours d’eau. Dans le contexte actuel de décentralisation de la production électrique ... [more ▼]

L’exploitation de l’énergie hydraulique, verte & renouvelable, a façonné au fil des siècles nombre de nos cours d’eau. Dans le contexte actuel de décentralisation de la production électrique & d’exploitation des sources non polluantes, l’hydroélectricité trouve un regain d’intérêt qui peut souvent s’accompagner de la remise en valeur d’un patrimoine bâti d’exception. La conférence détaillera ces points & les illustrera par de nombreux exemples. Parmi ceux-ci, la turbine hydroélectrique récemment mise en service au centre de Comblain-au-Pont, avec l’aide de la Région Wallonne, pour assurer l’autonomie énergétique de la Maison communale. [less ▲]

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See detailWho are “the people” in populist rhetoric? The case of the “Front National” (FN) and the “Freiheitliche Partei Österreichs” (FPÖ)
Debras, François ULg

Conference (2017, September 09)

In recent years, the “Front National” (FN) in France has claimed to be the “defender of the people” and “guarantor of their interests”. In 2017, the campaign slogan of Marine Le Pen, party leader and ... [more ▼]

In recent years, the “Front National” (FN) in France has claimed to be the “defender of the people” and “guarantor of their interests”. In 2017, the campaign slogan of Marine Le Pen, party leader and candidate in the presidential election, was “in the name of the people”. In Austria, the “Freiheitliche Partei Österreichs” (FPÖ) stood as the “voice of the oppressed majority”. The party is demanding “a direct democracy in order to let the people speak”. These elements lead us to question the notion of “the people”. How should we define “the people”? What reality does it refer to? What are the underlying political and ideological issues? Firstly, to answer this question, I aim to clarify the term “the people” in populist rhetoric. The FN and the FPÖ are often described as “far-right parties”. However, many scholars also refer to them as “populist parties”. These terms clearly need explaining. Secondly, this work will analyse the political discourse of the FN and the FPÖ. The focus will be on the political programmes and oral communication coming from their principal representatives. This analysis is discursive. It isn’t an examination of the work performed by party supporters or members (parliamentary work, action in local authorities, etc.). Apparently, the rhetoric from both parties is structured around two dichotomies: 1) the removal of social boundaries in favour of a people/elite opposition; 2) the affirmation of cultural boundaries in favour of an opposition between natives to a country and foreigners. I will explain why these notions of social and cultural boundaries have a prominent place in rhetoric in line with populist theory. The desire to suppress social boundaries, allows us to identity a first issue: sovereignty. The affirmation of cultural boundaries illustrates a second issue: unity. Finally, a third issue is transmitted through the notion of sovereignty and unity: identity. To conclude, I will return to the classification of the “Front National” and the “Freiheitliche Partei Österreichs” as “right-wing-populist” parties. I will end by answering the question: “who are ‘the people’”? This will explain why populist rhetoric responds to a feeling of unease within society and, more generally, within Western democracies. [less ▲]

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See detailInscription, iteration, transformation
De Winter, Mélanie ULg; Slomian, Cynthia ULg

Conference (2017, September 09)

In “Knowledge in policy”, Freeman and Sturdy propose a phenomenology with the aim of “knowing knowledge” (Freeman & Sturdy, 2014, p. 2). Knowledge can have different forms called “inscribed”, “embodied” ... [more ▼]

In “Knowledge in policy”, Freeman and Sturdy propose a phenomenology with the aim of “knowing knowledge” (Freeman & Sturdy, 2014, p. 2). Knowledge can have different forms called “inscribed”, “embodied” and “enacted”. This framework is presented as a way to categorize and describe the form, the circulation and the transformation of knowledge in policymaking. In this paper, we intend to focus on inscribed knowledge, and particularly on documents conceived as essential artefacts of public policies (Freeman & Maybin, 2011). Freeman and Sturdy defined inscribed knowledge as “written down in texts, or represented in pictures and diagrams; or it may be incorporated into instruments, tools and machines, among other things”(Freeman & Sturdy, 2014, p. 10). This form of knowledge is particularly “stable”, “easily reproducible” and “highly mobile” so “it can be communicated or made available to many different individuals separated in time and/or space”(Freeman & Sturdy, 2014, p. 10). This statement draws from works in sociology of science and technology. These works, especially Latour’s (1987) studies of the laboratory work and Law's (1986) analysis of control at distance particularly emphasize the power of inscriptions in constraining social action over time and space. Through the analysis of the implementation of two policy plans in the Belgian healthcare sector, we question and put the role of inscriptions in perspective with moments of enactment, by focusing on meetings. We intend to show that some documents are crucial at particular moments and lose value at other moments. In the same vein, we also aim to show the importance of iteration, moments, duration, and rhythms in public action. By doing so, we show how the public policy itself is transformed through time, documents and meetings. We address this issue by drawing on two PhD researches focusing on the devising and implementation of the policy plans mentioned above. By relying on interviews, observations and document analysis, we describe the policy strategies inscribed in documents as well as key moments of both documents’ trajectories. In so doing, we emphasise that documents and meetings articulate with each other in an iterative process that in turn transforms the public policies themselves. [less ▲]

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See detailTowards a web-based platform for plotting, visualizing and enriching diachronic semantic maps: With a case study on the Greek and Egyptian temporal semantic field
Georgakopoulos, Athanasios ULg; Polis, Stéphane ULg

Conference (2017, September 09)

Semantic maps aim at detecting cross-linguistic regularities and recurrent patterns in semantic structure (Haspelmath 2003). This method was initially applied to the grammatical domain, mostly in a ... [more ▼]

Semantic maps aim at detecting cross-linguistic regularities and recurrent patterns in semantic structure (Haspelmath 2003). This method was initially applied to the grammatical domain, mostly in a synchronic perspective (with some exceptions, see, e.g., van der Auwera & Plungian 1998). Recent research, however, has drawn attention to the lexical domain, showing that the model can also include lexical semantics (see, e.g., François 2008). Intimately related to the semantic map method has been the issue of finding appropriate ways of creating those maps and of capturing visually the semantic regularities. Up until recently, the maps were plotted and drawn manually. However, Regier et al. (2013) showed that a good approximation algorithm exists for inferring semantic maps based on polysemy data. Elaborating on their method, this paper aims to demonstrate that information about the directionality and the weight of the edges can be automatically added, thereby providing valuable information regarding the paths of semantic extensions and their frequency. In order to illustrate the method, we take the example of the semantic extension of time-related lexemes (e.g. TIME, HOUR, SEASON, DAY) in Ancient Greek (8th – 1st c. BC) and Ancient Egyptian – Coptic (26th c. BC – 10th c. AD). Both languages give access to significant diachronic material, allowing us to trace long term processes of semantic change. The results of our diachronic investigations are then checked against databases giving information on synchronic polysemies (e.g., List et al. 2014). In doing so, we also assess the adequacy of the use of polysemy as a tool to investigate semantic change. [less ▲]

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See detailCreativity and Innovation
Artige, Lionel ULg

Conference (2017, September 08)

Detailed reference viewed: 24 (0 ULg)
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See detailThe γ Dor stars as revealed by Kepler: A key to reveal deep-layer rotation in A and F stars
Salmon, Sébastien ULg; Ouazzani, R.-M.; Antoci, V. et al

in EPJ Web of Conferences (2017, September 08), 152

See detailUp-scalable spray-drying synthesis of Na2Ti3O7
Piffet, Caroline ULg; Vertruyen, Bénédicte ULg; Mahmoud, Abdelfattah ULg et al

Poster (2017, September 07)

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Peer Reviewed
See detailOptimization of hydroxyapatite synthesis via sol-gel process for bone reconstruction application
Tilkin, Rémi ULg; Regibeau, Nicolas ULg; Grandfils, Christian ULg et al

Poster (2017, September 07)

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently ... [more ▼]

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently based on the realization of temporary porous matrices, also called "scaffolds". Scaffolds are highly porous matrices notably designed to structure the development of cells, but also to guarantee the function of the implant during the regeneration process. Several materials have been proposed for the conception of scaffold. These have to meet strict criteria regarding biocompatibility, degradability, mechanical and surface properties. As a result of their biomimetism, bioceramics, like hydroxyapatite (Ca5(PO4)3(OH)), have been widely developed during the past few years for bone reconstruction. The aim of this study is the optimization of the synthesis of hydroxyapatite by sol-gel process to be used in the conception of scaffold for bone reconstruction application. In this optic, powder obtained from two synthesis processes (wet precipitation and sol-gel process) were compared with commercial hydroxyapatite. For wet precipitation process, calcium nitrate and phosphoric acid were used as reagent. For sol-gel process, calcium acetate was used as the source of calcium and triethylphosphate as the source of phosphate. Reagents were mixed and the solution was aged. The powder was then dried and sintered. Finally, particles were washed in HCl to remove CaO and then dried. Those new materials were characterized, particularly in terms of chemical composition (XRD, FTIR), crystallinity (XRD), morphology (SEM, TEM), size (TEM, DLS) and Ca/P ratio (EDX). [less ▲]