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See detailModeling of the cyclic lipodepsipeptide Pseudodesmin A self-assembly through molecular dynamic simulations
Crowet, Jean-Marc ULg; Sinnaeve, Davy; Fehér, Krisztina et al

Conference (2014, September 30)

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a ... [more ▼]

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a cyclic lipodepsipeptide of nine residues which presents a moderate antibacterial activity and whose structure has been resolved by X-ray and NMR. In acetonitrile, Pseudodesmine A is monomeric while in chloroform, it has the same structure but assembles in a supramolecular complex. This structure could associate with membranes and be responsible for the biological activity of the peptide. Comparison of NMR data in the two solvents has given indications on the intermolecular contacts that arise in chloroform and a model for the self-association was proposed. To study in more details this assembly, molecular dynamics simulations have been carried on. The resultswere compared with detailed information given by NMR, regarding the dimensions of the assembly and the orientation of the individual peptide building blocks inside the supramolecular assembly. In acetonitrile, the simulations show that the peptide has transient interactions while in chloroform, interactions between monomers are always observed. In agreement with NMR, these interactions arise mainly between the backbone protons of the LEU1 and the GLN2, the GLN2 sidechain and the loop located on the opposite end of the monomer structure. From 10 simulations of dimerization, hydrogen bonds were followed and specific interaction patterns were identified regarding the hydrogen bonds formed. Peptide interactions are mainly described by 13 interaction patterns characterized by 2 to 4 hydrogen bonds. In dimers, the peptides can have a linear, a perpendicular or a side by side configuration. From the linear dimer, it is possible to reconstruct filaments and, by combining a linear and a lateral dimer, it is possible to build fibrils with multifilaments, as found in the NMR-derived model. Two self-consistent supramolecular models can be built from dimers and they present a very good correlation with NMR data regarding the supramolecular organization. Besides, the perpendicular dimer can gives peptide rings that can also explain the potential ability of this peptide to form ion pores in membranes. [less ▲]

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See detailEtude de la flore spontanée de la carrière de Loën pour de futures restaurations - Rapport final
Pitz, Carline ULg; Mahy, Grégory ULg; Monty, Arnaud ULg et al

Report (2014)

Ce projet a pour objectif de caractériser la flore recolonisant spontanément les zones xériques non exploitées récemment de la carrière de Loën, du point de vue de la diversité spécifique et de la ... [more ▼]

Ce projet a pour objectif de caractériser la flore recolonisant spontanément les zones xériques non exploitées récemment de la carrière de Loën, du point de vue de la diversité spécifique et de la fonctionnalité écologique. Les communautés végétales ont été caractérisées au sein du site de Loën (diversité alpha) et d’un ensemble d’autres carrières représentatives de la diversité des contextes géographiques des carrières calcaires en Région Wallonne (diversité béta). L’étude a montré que, sur des laps de temps de plusieurs décennies, un processus de succession écologique s’est mis en place au sein du site de Loën, mais que cette succession ne tend pas vers une formation typique de pelouse sèche. Les explications peuvent être d’une part, que la disponibilité et l’apport de graines de pelouses sèches avoisinantes est insuffisant, et d’autre part, que le contexte abiotique pourrait être plus favorable à d’autres types de végétations herbacées. Cette étude illustre que des expériences de semis seraient souhaitable afin de définir les objectifs de restauration de la carrière de Loën et des carrières qui se trouvent dans des situations comparables. [less ▲]

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See detailPrevenção Quaternária e limites em medicina
Jamoulle, Marc ULg; Gomes, Luis

in Revista Brasileira de Medicina de Família e Comunidade (2014), 9(31),

O conceito de Prevenção Quaternária, um questionamento sobre a base da ação médica, nasceu na articulação da relação médico-paciente. Refere-se a toda a atividade médica, sendo uma importante ferramenta ... [more ▼]

O conceito de Prevenção Quaternária, um questionamento sobre a base da ação médica, nasceu na articulação da relação médico-paciente. Refere-se a toda a atividade médica, sendo uma importante ferramenta para a medicina de família. É uma interrogação ética sobre os excessos da demasiada e demasiadamente pouca medicina e fornece algumas respostas. [less ▲]

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See detailLa Belgique et les conventions internationales du travail
Detienne, Quentin ULg

in Journal des Tribunaux du Travail (2014)

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See detailDesign Thinking: l'approche empathique, clé de voûte de l'entreprise créative ?
Elsen, Catherine ULg

Conference given outside the academic context (2014)

La posture créative est à l’innovation ce que l’excellence opérationnelle est à l’entreprise: une démarche désormais incontournable. Et pourtant les plus sceptiques poussent nos communautés, avec raison ... [more ▼]

La posture créative est à l’innovation ce que l’excellence opérationnelle est à l’entreprise: une démarche désormais incontournable. Et pourtant les plus sceptiques poussent nos communautés, avec raison, à poursuivre la réflexion: que reste-t-il à apprendre des méthodes créatives divergentes, comme le brainstorming par exemple ? Comment éviter à l’avenir la mise en œuvre répétitive et décontextualisée de recettes « toutes faites » qui dénaturent la créativité et nuisent à sa crédibilité ? Ces inquiétudes seront analysées par Catherine Elsen à la lumière du Design Thinking, cette approche méthodologique qui pourrait bien faire favorablement évoluer les représentations et accompagner chaque entreprise dans la mise en œuvre d’un modèle créatif qui lui correspond réellement. Esquissée dès la fin des années 80 aux Etats-Unis par des entrepreneurs et innovateurs tels que David Kelley (fondateur d’IDEO, directeur de la d.school, Université de Stanford) ou Tim Brown (CEO actuel d’IDEO), la méthode repose sur deux piliers fondamentaux: l’approche empathique (du marché, des utilisateurs, mais aussi de l’entreprise elle-même) et le « quick and rough prototyping » (ou « protocept »), soit une matérialisation itérative précoce des idées, que certains qualifient d’agile. L’intervention abordera ces fondamentaux théoriques et leur mise en œuvre pratique au travers d’exemples d’applications et d’outils ré-appropriables. [less ▲]

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See detailInter-professional cooperation between family, occupational and social insurance physicians in managing long-term sickness absence
Mairiaux, Philippe ULg; Vanmeerbeek, Marc ULg; Schippers, Nathalie ULg et al

Conference (2014, September 30)

Background In the Belgian health system, sickness absence (SA) management implies complementary roles for general practitioners (GPs), social insurance physicians (SIPs) and occupational physicians (OPs ... [more ▼]

Background In the Belgian health system, sickness absence (SA) management implies complementary roles for general practitioners (GPs), social insurance physicians (SIPs) and occupational physicians (OPs): GPs deliver sick notes and treatment, SIPs control SA benefits and OPs strive to adapt work environments to workers’ remaining capacities. In practice however, there is little cooperation between the three physicians. In 2009, the Ministry of Employment commissioned a study to identify GP-OP-SIP cooperation channels in order to prevent long-term work disability. Methods The study involved two phases. 1) Researchers from the three groups agreed on 15 proposals to enhance cooperation: to establish a formal contact between GP, SIP and OP for patients with > 3 months SA (n=3) ; SIP decision to end SA benefit to be forwarded to the GP (n=2) ; work-related information to be provided by the OP to GP and/or SIP (n=4); website giving contact data of GPs, SIPs, and OPs (n=2) ; initial and continuous education focusing on inter-physician cooperation (n=3); electronic data exchange when dealing with long-term SA (n=1). 2) A Delphi study was conducted in 2012 to validate these proposals: 61 experts representing professional groups of physicians (GP, SIP, OP), patients, government, employers and labor unions were asked to participate. A 18-items questionnaire (the 15 proposals and 3 open questions) was used in a 2-round Delphi study. Proposals were accepted if 80% of experts agreed. For drafting the final proposals, the research team relied on a multidisciplinary expert group. Results Participation rate was 77% (47/61 experts) in round 1 and 7 out of the 15 proposals were accepted. During round 2, participation rate was 94% (44/47); 2 of the remaining proposals reached agreement level. Public authorities were thus advised to invest in a) promotion of pre-return to work visit with the OP for sick-listed patients; b) a website with OPs contact data; c) joint guidelines for return to work guidance; d) joint training of the 3 physician groups; 5) methods ensuring safe electronic information exchange. Conclusions The need for inter-physician cooperation in disability management may exceed individual goodwill and should best be organised by public authorities. The current study may be a first step in this process. [less ▲]

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See detailTable ronde autour de "Psychopathologie de l'homme en situation"
Englebert, Jérôme ULg

Scientific conference (2014, September 29)

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See detailEtude du rôle des sites de N-glycosylation dans la pathogenèse induite par le virus de la leucémie bovine
De Brogniez, Alix ULg

Doctoral thesis (2014)

Le virus de la leucémie bovine (BLV) est un deltarétrovirus responsable d’une maladie lymphoproliférative chez le bovin. Cette maladie, appelée leucose bovine enzootique, est responsable de pertes ... [more ▼]

Le virus de la leucémie bovine (BLV) est un deltarétrovirus responsable d’une maladie lymphoproliférative chez le bovin. Cette maladie, appelée leucose bovine enzootique, est responsable de pertes économiques importantes dans l’industrie laitière et viandeuse de nombreux pays dont notamment les Etats-Unis, l’Argentine et le Brésil. Ce rétrovirus infecte les lymphocytes B à l’aide de ses glycoprotéines virales SU et TM qui fusionnent avec la membrane cellulaire. Bien que de nombreuses études se soient penchées sur la caractérisation de la propagation virale, les composants cellulaires et viraux impliqués dans le contrôle de ce mécanisme ne sont toujours pas élucidés. Mon projet de thèse s’est donc attaché à la compréhension du rôle joué par les 8 sites potentiels de glycosylation présents sur la protéine SU du BLV. Chaque site du gène a été muté individuellement par mutagenèse dirigée. L’expression, la localisation, la capacité de fusion cellulaire et la stabilité protéique ont d’abord été étudiées en culture. Des provirus mutés ont ensuite été inoculés à des moutons afin d’évaluer leur potentiel infectieux et de suivre l’évolution de la pathogenèse induite. Nos études ont permis de mettre en évidence un mécanisme de glycosylation qui limite la réplication virale et ralentit la pathogenèse en faveur de la persistance virale. [less ▲]

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See detailMulti-period stochastic optimization problems in transportation management (Ph. D. Thesis Summary)
Pironet, Thierry ULg

in 4OR : Quarterly Journal of the Belgian, French and Italian Operations Research Societies (2014)

Ph. D Thesis summary see other reference on ORBI

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See detailQue sont devenus les manuels d'histoire d'antan ? Pour un nouveau concept de manuel scolaire
Jadoulle, Jean-Louis ULg

Conference given outside the academic context (2014)

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See detailCoordination of alkali metal ions to model branched hexasaccharides dictates fragment yield in MALDI in-source decay with hydrogen abstraction using 5-nitrosalicylic acid as the matrix
Asakawa, Daiki; Smargiasso, Nicolas ULg; De Pauw, Edwin ULg

in Journal of Mass Spectrometry [=JMS] (2014), 49

The differences among MALDI-ISD spectra of hexasaccharides cationized with various alkali metals are reflected in the different stabilities of the ‘hydrogen-deficient’ glycan radical. The stability order ... [more ▼]

The differences among MALDI-ISD spectra of hexasaccharides cationized with various alkali metals are reflected in the different stabilities of the ‘hydrogen-deficient’ glycan radical. The stability order of alkali metal-glycan radical complexes is proportional to the size of the alkali metal cation, K+ > Na+ > Li+. The Coordination of alkali metal ions to model branched hexasaccharides is the major parameter that dictates the fragment yield in MALDI in-source decay with hydrogen abstraction using 5-nitrosalicylic acid as the matrix [less ▲]

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See detailFrench good practice guidelines for the management of the low back pain risk among workers exposed to manual handling
Petit, Audrey; Mairiaux, Philippe ULg; FASSIER, Jean-Baptiste et al

Poster (2014, September 29)

Background Manual handling of loads (MHL) is a widespread practice in the workplace and is the leading cause of work accidents. In particular, MHL is associated with a risk of low back injuries which can ... [more ▼]

Background Manual handling of loads (MHL) is a widespread practice in the workplace and is the leading cause of work accidents. In particular, MHL is associated with a risk of low back injuries which can compromise staying at work and worker's career in the case of recurrence or chronicity. This communication aims to set forth the French occupational Guidelines for the management of the low back pain (LBP) risk among workers exposed to MHL, published in October 2013. Methods These Good Practice Guidelines were written according to the Clinical Practice Guidelines method proposed by the French National Authority for Health. They emanated from a synthesis of the literature by a multidisciplinary working party of 24 experts and were peer reviewed by a committee of 50 experts. These Guidelines are designed to define the components of an appropriate surveillance program for all workers exposed to MHL activities at the workplace and especially suffering from LBP and still at work, or suffering LBP and on sick leave. Results Because of the potential impact on workers’ fears and beliefs, the information provided by the various actors must be consistent, or even reassuring in relation to the prognosis of LBP. Among LBP workers, it is recommended to look for signs of severity or an underlying disease at the acute, subacute and chronic stages of LBP; to encourage continuation or resumption of physical activity; situate the current episode of LBP in the worker’s work history (recent changes of working conditions) and evaluate the impact of LBP on the worker’s job. In the case of persistent or recurrent LBP, it is recommended to evaluate biopsychosocial and socioeconomic risk factors likely to influence chronicity, prolonged incapacity and delay return to work. If workers are on prolonged and/or repeated sick leave for LBP, a pre-return-to-work visit is recommended to evaluate the pain and functional disability and their repercussions, as well as the main factors of prolonged work incapacity; encourage and help the worker to develop a return to work dynamic; identify the main difficulties related to work and possible job adjustments and evaluate the need to initiate a job staying at work approach. Conclusions Primary, secondary and tertiary prevention are necessary for the management of low back pain at work. [less ▲]

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See detailDétermination de la durabilité des complexes parois et toitures vis-à-vis d’attaques biologiques
Jourez, Benoît ULg; Hebert, Jacques ULg; Christiaens, Christophe ULg et al

Conference given outside the academic context (2014)

Le secteur de la construction est en perpétuel évolution et de nouveaux systèmes constructifs sont proposés aux candidats bâtisseurs. Ils vissent à répondre aux nouvelles exigences de performance ... [more ▼]

Le secteur de la construction est en perpétuel évolution et de nouveaux systèmes constructifs sont proposés aux candidats bâtisseurs. Ils vissent à répondre aux nouvelles exigences de performance (mécanique, acoustique, thermique), de développement durable ainsi qu'à des exigences économiques. Néanmoins, ces nouveaux systèmes constructifs innovants, pour lesquels un manque de recul est observé, doivent encore démontrer leur capacité à maintenir dans le temps leur efficacité initiale et leur durabilité afin d'aboutir à des systèmes performants, durables et sans risques de pathologie. A ce titre, ces complexes, la paroi perspirante et la toiture plate compacte, doivent faire l'objet d'investigations en vue d'évaluer leur durabilité vis-à-vis des attaques par les agents de dégradation biologique. La tendance actuelle s'oriente vers des complexes constitués en majorité de matériaux biodégradables (bois, panneau, isolant naturel) tout en évitant l'emploi de produits nocifs pour la santé des habitants qui sont de plus en plus conscients de leur empreinte écologique et réticents à l'incorporation de substances chimiques potentiellement nocives. Il est à noter cependant que les constituants de ces complexes bien que biodégradables doivent aussi faire preuve d'une durabilité suffisante qui ne devrait pas être limitée à la durée de la garantie décennale assumée par le concepteur/entrepreneur du bâtiment mais s'étendre à la durée de vie de celui-ci. L'origine du projet OPTIDUBO repose sur le fait que le comportement hygroscopique de ces complexes et leur durabilité face à l'attaque des agents biologiques de dégradation (insectes xylophages et champignons lignivores) sont peu connus ou documentés alors que ceux-ci sont de plus en plus utilisés dans la construction d'habitations. Ce chapitre se focalise sur la détermination de la durabilité des complexes parois perspirantes et toiture plate compacte vis-à-vis des agents biologiques de dégradation. Il vise à répondre aux deux questions suivantes:  Dans ces complexes, un ou plusieurs des constituants de la paroi sont-ils attaquables ?  Le traitement de l'isolant au sel de bore est-il susceptible de protéger efficacement le complexe de toute attaque? [less ▲]

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See detailTheoretical studies of PbTiO3 and SrTiO3 under uniaxial mechanical constraints combining first-principles calculations and phenomenological Landau theory
Sharma, Henu ULg

Doctoral thesis (2014)

In the present thesis we present theoretical studies of perovskite compounds under uniaxial mechanical constraints combining first-principles DFT calculations approach and phenomenological Landau theory ... [more ▼]

In the present thesis we present theoretical studies of perovskite compounds under uniaxial mechanical constraints combining first-principles DFT calculations approach and phenomenological Landau theory. ABO$_3$ perovskites form a very important class of functional materials that can exhibit a broad range of properties (e.g., superconductivity, magnetism, ferroelectricity, multiferroism, metal-insulator transitions\ldots) within small distortions of the same simple prototype cubic structure. Though these compounds have been extensively studied both experimentally and computationally, there are still unresolved issues regarding the effect of pressure. In recent years, strain engineering has reported to be an original approach to tune the ferroelectric properties of perovskite ABO$_3$ compounds. While the effect of epitaxial biaxial strain and hydrostatic strain is rather well understood in this class of materials, very little is yet known regarding the effect of uniaxial mechanical constraints. Our study is motivated by the little existing understanding of the effect of uniaxial strain and stress, that has been up to now almost totally neglected. Two prototype compounds are studied in detail: PbTiO$_3$ and SrTiO$_3$. After a general introduction on ABO$_3$ compounds and calculations techniques (ab initio and phenomenological Landau model), we studied the effect of mechanical constraints in these compounds in our thesis. PbTiO$_3$ is a prototypical ferroelectric compound and also one of the parent components of the Pb(Zr,Ti)O$_3$ solid solution (PZT), which is the most widely used piezoelectrics. For PbTiO$_3$, we have shown that irrespectively of the uniaxial mechanical constraint applied, the system keeps a purely ferroelectric ground-state, with the polarization aligned either along the constraint direction ($FE_z$ phase) or along one of the pseudo-cubic axis perpendicular to it ($FE_x$ phase). This contrasts with the case of isotropic or biaxial mechanical constraints for which novel phases combining ferroelectric and antiferrodistortive motions have been previously reported. Under uniaxial strain, PbTiO$_3$ switches from a $FE_x$ ground state under compressive strain to $FE_z$ ground-state under tensile strain, beyond a critical strain $\eta_{zz}^c \approx +1$\%. Under uniaxial stress, PbTiO$_3$ exhibits either a $FE_x$ ground state under compression ($\sigma_{zz} < 0$) or a $FE_z$ ground state under tension ($\sigma_{zz} > 0$). Here, however, an abrupt jump of the structural parameters is also predicted under both compressive and tensile stresses at critical values $\sigma_{zz} \approx$ $+2$ GPa and $- 8$ GPa. This behavior appears similar to that predicted under negative isotropic pressure and might reveal practically useful to enhance the piezoelectric response in nanodevices. The second compound of interest is SrTiO$_3$. It has been widely studied in the past decades due to its unusual properties at low temperature. In this work, we have extended our previous investigations on PbTiO$_3$ by exploring theoretically the pressure effects on perovskite SrTiO$_3$ combining the first-principles calculations and a phenomenological Landau model. We have discussed the evolution of phonon frequencies of SrTiO$_3$ with the three isotropic, uniaxial and biaxial strains using first-principles calculations. We also reproduce the previous work done in SrTiO$_3$ with epitaxial strain and hydrostatic strain. Finally, we have calculated the phase diagram of SrTiO$_3$ under uniaxial strain, as obtained from Landau theory and discussed how it compares with the first-principles calculations. [less ▲]

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See detailFITNESS EVALUATION OF A RECOMBINANT MURINE NOROVIRUS DURING SERIAL PASSAGES IN CELL CULTURE
Oliveira-Filho, Edmilson; Di Felice, Elisabetta; Toffoli, Barbara et al

Poster (2014, September 28)

Noroviruses are single stranded positive sense RNA viruses which can infect human and different animal species. Human norovirus (NoV) infections are among the most important causes of gastroenteritis in ... [more ▼]

Noroviruses are single stranded positive sense RNA viruses which can infect human and different animal species. Human norovirus (NoV) infections are among the most important causes of gastroenteritis in both children and adults. Infections often occur as outbreaks which may be foodborne. Due to the lack of an efficient cell culture system as well as a workable animal model, many aspects of the NoV infection in human are still poorly understood. The murine norovirus (MuNoV) grows easily in cell culture in contrast to the Human NoV, and constitutes an excellent animal model. Recombination can dramatically change virulence properties of the viruses and has been evidenced in silico for different human NoV strains isolated from clinical cases. Recently, after in vitro coinfection of RAW264.7 cells with parental MuNoV strains CW1 and Wu20, we obtained a recombinant Wu20/CW1 strain. This recombinant strain showed reduced plaque size compared to the parental strains. The aim of the study was to observe and molecularly characterize the natural genetic evolution of the recombinant MuNoV strain across in vitro replications. Viral fitness is a complex concept. Here we defined this fitness as the ability of a viral population to adapt to the cell culture system. Thus, the recombinant strain was serially replicated in vitro in RAW264.7 cells (up to 14 passages). Viral plaque sizes of early and late progenies were compared with the Image J software. A significant difference was shown between them with the Mann and Whitney non parametric statistical test. Afterwards, viruses from different cell passages were cloned and sequenced. The average plaque size increased from the earlier to the later progenies (from 0.1 mm2 to around 0.5 mm2). Molecular investigations are currently performed in order to specify in which genetic region mutations occur and whether or not this could explain fitness modifications during in vitro evolution. In addition, two other parameters of in vitro virulence modification will be investigated: (i) virus production and (ii) one step growth kinetics. The data should provide interesting information about genetic evolution in the genus Norovirus, especially regarding recombination events and explain how a recombinant strain, first disadvantaged compared to its parental strains, could regain fitness by genetic evolution. [less ▲]

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See detailLe rôle des historiens dans le processus de reconversion des sites industriels en Wallonie
Destatte, Julien ULg; Defechereux, Olivier ULg; Peters, Arnaud ULg

Conference given outside the academic context (2014)

Detailed reference viewed: 11 (4 ULg)