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See detailSolid-supported synthesis of peptidoglycan fragments and their biological evaluation
Simon, Justine ULg

Doctoral thesis (2016)

In this work, a new methodology for the synthesis of peptidoglycan fragments containing (2S,6R)-A2pm is proposed. Thanks to a solid phase platform, cross metathesis was achieved between two easily ... [more ▼]

In this work, a new methodology for the synthesis of peptidoglycan fragments containing (2S,6R)-A2pm is proposed. Thanks to a solid phase platform, cross metathesis was achieved between two easily manufactured chiral synthons, allylglycine anchored to a resin and vinylglycine derivatives. Due to the need of fragments for the study of the peptidoglycan recycling, this modular efficient platform could be useful to synthesize diverse derivatives of other peptides and muropeptides containing (2S,6R)-A2pm. In the framework of this project, (S)-Ala-γ-(R)-Glu-(2S,6R)-A2pm-(R)-Ala and γ-(R)-Glu-(2S,6R)-A2pm were synthesized. Their interactions with the R39 peptidase were studied by X-ray diffraction. According to the crystallographic results, (S)-Ala-γ-(R)-Glu-(2S,6R)-A2pm-(R)-Ala 1 is a reversible covalent binding inhibitor of R39. These data are supported by an enzymatic study using the thioesterase activity of the R39 peptidase on (R)-S2d. Because of the specific affinity for the R enantiomer of thioesters, the enantioselective synthesis of (R)-S2d is described that makes use of the coupling agent T3P. A chromatographic method is proposed to evaluate the degree of thioester racemization. The kinetics of the interaction between the thioester and different PBPs were studied and a protocol for microtiter plate-based assays is developed allowing the screening of compound libraries for inhibitors of PBPs. In the future, the synthesized peptidoglycan fragments will be used as reference compounds in the framework of the NetRBI project. [less ▲]

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See detailCharacterization, dynamics and trophic ecology of macrofauna associated to seagrass macrophytodetritus accumulations (Calvi Bay, Mediterranean Sea)
Remy, François ULg

Doctoral thesis (2016)

Posidonia oceanica meadows are a major coastal Mediterranean ecosystem. Although highly productive this Mediterranean marine flower plant is not much consumed by herbivore organisms. During autumnal ... [more ▼]

Posidonia oceanica meadows are a major coastal Mediterranean ecosystem. Although highly productive this Mediterranean marine flower plant is not much consumed by herbivore organisms. During autumnal senescence, most (up to 90%) of the foliar primary production of P. oceanica ends in the “detrital compartment”. These dead leaves, also called “macrophytodetritus”, begin to degrade immediately inside the meadow, but a large amount will be rapidly exported to adjacent unvegetated accumulation zones, such as bare sand patches. Associated to drift macroalgae, living detached P. oceanica shoots, micro-organisms and fine sediment, these macrophytoderitus form what we call “exported P. oceanica litter”. This exported litter is a highly dynamic habitat for a whole community of invertebrates: meiofauna (38µm < size < 500µm) and macrofauna (size ≥ 500µm) on which we focused on. This dynamic nature of exported litter could play a major structuring role in terms of abundance, diversity and trophic ecology of this vagile macrofauna community at a seasonal, annual or spatial scale, but also during stochastic, brief and very strong perturbations: resource pulses. In this context, this PhD Thesis had 7 main objectives: i. Characterize for the first time exhaustively the macrofauna community. ii. Evaluate the spatiotemporal changes occurring at two different time scales in the detritus themselves and in the macrofauna community. iii. Relating these variations with measured environmental parameters. iv. Experimentally demonstrate the stratification occurring in a stable P. oceanica litter accumulation and the impact of this stratification on environmental conditions and on the macrofauna. v. Experimentally demonstrate the impact of resource pulses on the exported P. oceanica litter macrofauna community. vi. Unravel for the first time the global P. oceanica litter macrofauna food web using gut contents examinations and stable isotopes (C and N). vii. Evaluate the spatiotemporal changes of diet preferences of this community and determine if the observed changes are really synonym of true diet changes. This PhD Thesis demonstrated that exported P. oceanica litter was mainly composed of dead P. oceanica leaves (70-80%). It followed the natural annual cycle of P. oceanica and presented a maximum abundance in autumn just after leaves senescence. Measured environmental parameters also showed important variations linked to different factors such as force and direction of the wind, litter abundance and probably temperature. The continuous presence of the vagile macrofauna community throughout the year was demonstrated as well. This community was composed of 115 species and largely dominated by arthropods (77%), followed by annelids (12%) and mollusks (7%), while other taxa were much more anecdotal. Even if diversity is quite important, only a few species dominate largely the community. Indeed, 19 species represent more than 90% of the total abundance. One species to keep in mind: Gammarella fucicola, the most typical dominant and abundant amphipod species, representing 40-50% of the total abundance. In addition to this general pattern, litter vagile macrofauna presented important seasonal and annual variations. In the case of several species, these variations could be linked to some measured environmental parameters, but we had to recognize that most species did not seem to be influenced by environmental parameters measured during this PhD. However, oxygen concentration was the most important environmental parameter, potentially influencing 7 of the 19 most dominant and abundant species. The experimentally demonstrated physico-chemical stratification occurring inside litter accumulations was strongly related to this oxygen parameter. Indeed we demonstrated that several species were distributed in the different layers of a litter accumulation according to oxygen concentration and to a lesser extent, to nutrients concentration (mostly NH4). Besides, smaller time scale sampling allowed the identification of several stormy events corresponding to the definition of resource pulses. These pulses were demonstrated to play a potentially important role on the structure of the macrofauna community, favoring importantly the detritivore species and hypoxia tolerant species. It was also demonstrated that resource pulses could induce diet switching increasing the consumption of dead P. oceanica leaves just after the events, potentially increasing the litter decomposition by the macrofauna. The trophic web described in this PhD Thesis was composed of several trophic levels, from the primary herbivore/detritivore consumer, to second order carnivore predators. Different dietary preferences were highlighted, but major information was that dead P. oceanica leaves were ingested by a majority (85%) of the sampled species. Moreover, stable isotope analysis confirmed that P. oceanica litter was assimilated by most primary consumers and this “detrital signal” could be identified to the upper trophic levels, which is an argument in favor of the importance of macrofauna as major dead P. oceanica leaves decomposers. This also highlighted their potential role in terms of organic matter transfer from the P. oceanica meadow itself to the Mediterranean coastal food webs. Seasonal variations were observed in terms of trophic niches, and SIAR mixing model confirmed that this variability was sometimes caused by real diet modifications, potentially linked to the variable availability of food sources. This PhD Thesis, combining standardized sampling at two different time scales, trophic web analysis (gut contents and stable isotopes) and original experimentation allowed us to describe a diverse and abundant macrofauna community associated to P. oceanica exported litter, its temporal variations, potential responses to resource pulses as well as the link existing between some species and measured environmental parameters. This PhD also described the food web of this community and demonstrated the importance of dead P. oceanica leaves as food source for many invertebrates composing this community. These invertebrates thus seemed to play an important role in both litter decomposition and organic matter flux from the P. oceanica meadow to the Mediterranean coastal food webs. [less ▲]

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See detailMolecular detection of single nucleotide polymorphisms on whole blood without DNA extraction
Detemmerman, L.; BOEMER, François ULg; SEGERS, Karin ULg et al

Poster (2016, May 12)

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See detailLe passé en France au XVIIe siècle. Représentations, usages et transferts des savoirs historiques
Saal, Caroline ULg

Doctoral thesis (2016)

La majeure partie des études sur le passé au XVIIe siècle se porte sur l’historiographie, sur la théorie de l’histoire et sur son écriture à cette époque. Grâce au développement de l’histoire des idées et ... [more ▼]

La majeure partie des études sur le passé au XVIIe siècle se porte sur l’historiographie, sur la théorie de l’histoire et sur son écriture à cette époque. Grâce au développement de l’histoire des idées et de l’histoire culturelle, de nouvelles approches ont émergé. Pour l’histoire moderne française, elles prennent essentiellement la forme d’études de figures souvenirs et de leur prégnance dans une culture donnée. Mais deux postulats m’ont invitée à travailler autrement, hors des pratiques historiennes et sans choisir a priori de figures-souvenirs. Le premier tient à l’acquisition des savoirs historiques. La connaissance que possède une personne sur le passé de la communauté humaine résulte d’une multitude de vecteurs et de médias, de nature et d’objectifs divers, et, plus encore, elle résulte de leur croisement. Le second postulat provient des innovations en histoire des savoirs de ces dernières années : une société ancienne repose sur un système de pensée et sur une configuration des savoirs distincte de la nôtre. Pour travailler sur les savoirs sous l’Ancien Régime, il faut appréhender l’altérité d’un ancien régime des savoirs et, plutôt que de rechercher la généalogie de disciplines, regarder à l’œuvre ces savoirs mixtes, aux nombreuses ramifications, la manière de les créer, de se les approprier et de les utiliser. Certes, Reinhart Koselleck et Kristof Pomian avaient déjà produit d’importants enseignements sur les processus. On a longtemps considéré qu’ils avaient probablement tout dit. Il fallait pourtant vérifier la percolation de ces enseignements au-delà des génies créateurs et des penseurs institués. Cette thèse étudie ces processus dans des opérations d’appropriation des savoirs historiques au sein des publics alphabétisés et la compréhension de ces savoirs en société : les pamphlets « historiés » de la Fronde, les conférences du Bureau d’Adresse de Théophraste Renaudot et des estampes ludiques – jeux de carte et jeux de l’oie historiques. Elle démontre le rôle de ces imprimés de forme brève comme lieux d’acculturation des savoirs historiques, mettant à disposition un prêt-à-penser sur le passé. S’inspirant des grilles de lecture des théories de la pensée complexe, développée entre autres par Edgar Morin, elle éclaire la pluralité des questions que se posaient les hommes de l’époque moderne sur leur passé, et les liens entre ces questions, leur lieu social d’émergence, les pratiques de la connaissance et les paradigmes culturels. [less ▲]

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See detailDepositional Sequences of the Late Pleistocene Shoreline System, Bor Basin, Southern-Central Anatolia: Implications for Reconstructing Lake Level Changes
Bayer Altın, Türkan; El Ouahabi, Meriam ULg; Fagel, Nathalie ULg

Conference (2016, May 08)

The Bor Basin is located in the east part of the Konya-Ereğli Plain occupied by Pleistocene lake (Fig. 1). Paleo-shoreline deposits rising western margins of the basin marked the former extent of a now ... [more ▼]

The Bor Basin is located in the east part of the Konya-Ereğli Plain occupied by Pleistocene lake (Fig. 1). Paleo-shoreline deposits rising western margins of the basin marked the former extent of a now desiccated Late Pleistocene Lake. This study evaluates the former lake level changes and the sequential evolution of a shoreline system that developed at the western margin with lacustrine fills of the Bor paleolake near Zengen settlement. The fills belongs to alluvial fans formed by streams coming from the high volcanic mountains located within the northern part of the basin. The sediment sequence of the fan reflects receded and extended levels of the former lake. 23 samples were obtained at the sand-quarry representing of various facies of the lacustrine fills. These samples were analyzed for mineralogical characterization, using XRD and their CaCO3 values were quantified. According to analysis, three evident different phases of weathering were distinguished in this deposit (Fig. 2). Weathering conditions occurred at the bottom of the profile (level 7) with the appearance of the vermiculite and illite/smectite mixed layer clays. Aridification phases occurred at the level of sample 16 with the appearance of the palygorskite. At the shallow levels from the samples 21 to 22, another aridification phase occurred attested by the appearance of the palygorskite, the mixed layers clays (illite/smectite) and the neoformation of the chlorite by weathering. The palygorskite occurrence showed only in the clay fraction (<2µm) associated with dolomite levels which support its secondary formation during dry periods and pedogenetic transformation. Pedogenesis conditions were attested also by the presence of the mixed layers clays at those levels. [less ▲]

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See detailUne phénoménologie clinique du Rorschach : des masques et un malentendu
Englebert, Jérôme ULg

Conference (2016, May 04)

Afin d’évoquer la dimension phénoménologique intrinsèque du test de Rorschach, je propose de partir de l’ouvrage magistrale de Roland Kuhn Phénoménologie du masque à travers le test de Rorschach (1957) et ... [more ▼]

Afin d’évoquer la dimension phénoménologique intrinsèque du test de Rorschach, je propose de partir de l’ouvrage magistrale de Roland Kuhn Phénoménologie du masque à travers le test de Rorschach (1957) et des commentaires livrés à son propos par Gaston Bachelard et Jean Starobinski. Ce premier temps me permettra de « démasquer » une épistémologie, œuvrant en sourdine tant dans le test que dans la phénoménologie, celle des visages. Passant ensuite par Foucault – à travers son énigmatique attrait pour le test de Rorschach et sa fascination, toute son œuvre durant, pour les masques – j’interrogerai les notions d’autoréflexion (Foucault, 1966) et d’hyper-réflexivité (Sass, 1994) telles qu’elles se manifestent dans la clinique du patient schizophrène. Le second temps de mon exposé s’intéressera dès lors aux étranges réponses fournies par ces patients au test des taches d’encre lorsqu’ils expriment précisément : « ce ne sont que des taches ». Cette proposition, qui se révèle plus exacte qu’il n’y parait, révèle le malentendu visuel sur lequel repose le Psychodiagnostik de Rorschach. L’observation de ce malentendu nous permettra de conclure que le sujet, lorsqu’il est en « situation Rorschach », doit accepter implicitement le jeu paradoxal consistant à fournir une « fausse perception » et à tolérer un certain degré de violation de la réalité. [less ▲]

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See detailHow Service Managers Can Shape Frontline Employees' Organizational Values to Reduce Person-Role Conflicts
Selzer, Veronika Luisa; Schumann, Jan Hendrik; Büttgen, Marion et al

Conference (2016, May)

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See detailL’institutionnalisation du droit international (1869-1873). Les réseaux internationaux de Gustave Rolin-Jaequemyns
Genin, Vincent ULg

in Journal of the History of International Law / Revue d'Histoire du Droit International (2016), 18(2-3), 181-196

This article deals with a phenomenon which appears in a particular context: the institutionalisation of international law between 1869 (creation of the Revue de droit international et de législation ... [more ▼]

This article deals with a phenomenon which appears in a particular context: the institutionalisation of international law between 1869 (creation of the Revue de droit international et de législation comparée) and 1873 (birth of the Institut de Droit International), through the international networks of the Belgian lawyer Gustave Rolin-Jaequemyns. He was close to Pasquale Mancini, John Westlake, James Lorimer, Franz Von Holtzendorff, but also to the least-known Michael Corr-Van der Maeren, a publicist. Until this period of crystallisation this field was not structured and represented an aggregate of individualities. What can we say about such a process of institutionalisation on the basis of unpublished archives? The history of international law, until today, especially studied by lawyers, was very neglected by historians, whose methods and sources are complementary to those of the lawyer. Our contribution wishes to contribute to the development of a history of international law written by historians. [less ▲]

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See detailQuand les cultures alimentaires se rencontrent. (Re)définition et transmission des pratiques dans un atelier de cuisine arabe en Italie.
Mescoli, Elsa ULg

Conference (2016, May)

Le déplacement des individus est toujours accompagné par le mouvement de choses et pratiques qui voyagent avec eux. Ce fait permet d’étudier la culture matérielle engagée par la mobilité des personnes ... [more ▼]

Le déplacement des individus est toujours accompagné par le mouvement de choses et pratiques qui voyagent avec eux. Ce fait permet d’étudier la culture matérielle engagée par la mobilité des personnes. Cette culture inclut les habitudes alimentaires, qui font l’objet de plusieurs recherches portées sur les changements culinaires (ou les résistances) déterminés par la migration. Loin d’être le seul enjeu constaté lorsque l'on étudie les pratiques alimentaires des migrants – qui par ailleurs sont souvent considérées comme statiques avant la migration –, cette question amène souvent à négliger d'autres dynamiques importantes qui sont également à l’œuvre. Telles que celles qui se produisent lorsque des cultures alimentaires qui se prétendent différentes se rencontrent, ce qui conduit à la mobilisation d’appartenances par les membres de différents groupes culturels qui veulent prendre une position spécifique chacun par rapport à l'autre. Mon exposé vise à analyser cette rencontre. L'hypothèse est qu’elle façonne un espace qui correspond à un tertium quid, une dimension où les frontières des cultures alimentaires peuvent également s’atténuer en raison notamment de la (re)définition et de la transmission des pratiques. Afin de décrire ces dynamiques, je présenterai les données ethnographiques collectées durant un terrain ethnographique porté sur les pratiques culinaires d'un groupe de femmes migrantes marocaines vivant dans la périphérie de Milan, en Italie. Je vais également appuyer ma présentation sur des matériaux visuels recueillis lors des observations et des entretiens dans les maisons ainsi que dans des événements publics tel qu’un cours de cuisine arabe. [less ▲]

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See detailMot de cloture
Mescoli, Elsa ULg; Sarcinelli, Alice ULg

Conference (2016, May)

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See detailNouveaux visages des dieux en Égypte gréco-romaine
Veymiers, Richard ULg

in Quertinmont, Arnaud (Ed.) Dieux, génies, démons en Égypte ancienne. Musée royal de Mariemont, du 21 mai au 20 novembre 2016 (2016)

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See detailDeveloping Tourism Products and new Partnerships through Participative Action Research in Rural Cameroon
Schmitz, Serge ULg; Lekane Tsoubgou, Dieudonné

in Geographical Research (2016), 54(2), 143-152

The paper explores possible synergies between microfinance institutions and small and medium medium tourism businesses in the West Cameron Chiefdooms. Based on a research action the authors emphasise the ... [more ▼]

The paper explores possible synergies between microfinance institutions and small and medium medium tourism businesses in the West Cameron Chiefdooms. Based on a research action the authors emphasise the obstacles to the formation of partnership and describe how the researchers facilitated networking. [less ▲]

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See detailCarbon xerogels as model materials: toward a relationship between pore texture and electrochemical behavior as anodes for lithium-ion batteries
Piedboeuf, Marie-Laure ULg; Léonard, Alexandre ULg; Deschamps, Fabien ULg et al

in Journal of Materials Science (2016), 51(9), 4358-4370

The mechanisms of Li+ insertion in porous hard carbons used as anodes for Li-ion batteries are still a matter of debate, especially considering the divergence of electrochemical performances observed in ... [more ▼]

The mechanisms of Li+ insertion in porous hard carbons used as anodes for Li-ion batteries are still a matter of debate, especially considering the divergence of electrochemical performances observed in literature. Since these materials usually exhibit several levels of porosity, the pore texture vs. electrochemical behavior relationship is difficult to establish. In this paper, we propose to use carbon xerogels, prepared from aqueous resorcinol-formaldehyde mixtures, as model materials for Li-ion battery anodes to study the influence of the pore texture on the overall electrochemical behavior. Indeed, carbon xerogels are described as microporous nodules linked together to form meso- or macroporous voids inside a 3D gel structure; the size of these voids can be tuned by changing the synthesis conditions without affecting other parameters such as the micropore volume. The materials are chosen so as to obtain identical average particle sizes, homogeneous coatings with similar thicknesses and a comparable surface chemistry. The electrochemical behavior of carbon xerogels as Li-ion anodes are correlated with the surface accessible to the electrolyte and are not dependent on the total specific surface area calculated by the BET method from nitrogen adsorption isotherms. The key parameter proposed to understand their behavior is the external surface area of the nodules, which corresponds to the surface of the meso/macropores. [less ▲]

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See detailReflexive Loops on Scaling issues in Landscape Quality Assessment
Schmitz, Serge ULg; Vanderheyden, Vincent ULg

in Land Use Policy (2016), 53

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See detailChitosan-based nanofibers mats for tissue engineering
Aqil, Abdelhafid ULg; Croisier, Florence ULg; Colige, Alain ULg et al

Conference (2016, May)

Polymer hydrogels resemble the natural living tissue due to their high water content and soft consistency. They find many applications in the design and production of contact and intraocular lenses ... [more ▼]

Polymer hydrogels resemble the natural living tissue due to their high water content and soft consistency. They find many applications in the design and production of contact and intraocular lenses, biosensors membranes, matrices for repairing and regenerating a wide diversity of tissues and organs. Polysaccharides such as chitosan and hyaluronic acid based hydrogels have shown a great potential for biomedical and pharmaceutical applications, on account of their remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make them outstanding candidates for short- to medium-term applications, especially for tissue engineering. In this respect, the preparation of nanometric fibers mats based on this polysaccharide are highly interesting as such structure mimics the one of skin extracellular matrix. Such nanofibrous materials can be prepared by electrospinning (Figure 1). This technique uses a high voltage to create an electrically charged jet of polymer solution to obtain polymer fibers ranging from nanometers to a few microns in diameter. We thus have investigated strategies allowing to generate chitosan based nanofiber mats exhibiting a mechanical resistance strong enough to be easily handled while keeping the peculiar features of chitosan hydrogels favoring the interaction with cells and soft tissues to provide efficient tissue reconstruction. In a first strategy, polysaccharide-based nanofibers with a multilayered structure were prepared by combining electrospinning (ESP) and layer-by-layer (LBL) deposition techniques. Elastic nanofibers bearing charges at their surface were firstly prepared by electrospinning poly(ε-caprolactone) (PCL) with a polyelectrolyte precursor. After activation by adjusting the pH, the layer-by-layer deposition of chitosan and hyaluronic acid, can be used to coat the electrospun fibers. A multilayered structure is then achieved by alternating the deposition of the positively charged chitosan with the deposition of a negatively charged polyelectrolyte. These novel polysaccharide-coated PCL fiber mats remarkably combine the mechanical resistance typical of the core material (PCL) – particularly in the hydrated state –, with the surface properties of chitosan. Besides, crosslinked nanofibrous mats of chitosan and polyethylene oxide blends, were successfully prepared via electrospinning technique followed by heat mediated chemical crosslinking. This chemical cross-linking allows adjusting the mechanical resistance of the mats while preserving their biocompatibility. In both cases, the control of the nanofiber structure offered by the electrospinning technology, makes the developed processes very promising to precisely design biomaterials for tissue engineering. Preliminary cell culture tests corroborate the potential use of such systems in wound healing applications. [less ▲]

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