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See detailReactivación de las negociaciones Euro-Mercosur bajo el temor del ‘síndrome mejicano’?
Santander, Sébastian ULg

in Revista de Derecho Internacional y del Mercosur (2002), 1

L'UE agit semble avoir une stratégie réactive sur la scène internationale. La mise en place de l'ALENA a eu un effet de commerce important au détriment de l'UE mais au profit des Etats-Unis. Cette ... [more ▼]

L'UE agit semble avoir une stratégie réactive sur la scène internationale. La mise en place de l'ALENA a eu un effet de commerce important au détriment de l'UE mais au profit des Etats-Unis. Cette conséquence négative a poussé les instances européennes à négocier et conclure rapidement l'accord global avec le Mexique. La même situation semble se produire dans les relations avec le Mercosur. [less ▲]

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See detailReactivation of HIV-1 after an oxidative stress
Piette, Jacques ULg; Legrand-Poels, Sylvie; Vaira, Dolorès ULg et al

in Free Radicals in Biology and Medicine (1990), 9(Suppl. A), 5

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See detailReactivation of infectious bovine rhinotracheitis virus by transport.
Thiry, Etienne ULg; Saliki, J.; Bublot, M. et al

in Comparative Immunology, Microbiology and Infectious Diseases (1987), 10(1), 59-63

Transport was studied as a cause of reactivation of infectious bovine rhinotracheitis virus (Bovine herpesvirus-1; BHV-1) in heifers vaccinated 2-6 months before transport, using a double dose of the ... [more ▼]

Transport was studied as a cause of reactivation of infectious bovine rhinotracheitis virus (Bovine herpesvirus-1; BHV-1) in heifers vaccinated 2-6 months before transport, using a double dose of the thermosensitive (ts) vaccine strain (Tracherine). Eight out of 19 animals showed ts strain re-excretion over a period of 1-3 days, beginning, in 5 out of the 8 heifers, the day after transport. In 14 other heifers, only sera were examined by sero-neutralisation: only 1 out of these 14 animals showed a rise in BHV-1 neutralising antibodies. Transport can therefore be considered as a stimulus of BHV-1 reactivation. [less ▲]

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See detailReactive Attachment Disorder and socio-emotional development in childhood: Clinical review.
Wertz, Céline ULg; Gauthier, Jean-Marie ULg; Blavier, Adelaïde ULg

Poster (2011, May 27)

The quality of interactions experienced with primary attachment figures influence the development of emotional skills. On the other hand, we know how emotions fill a critical adaptive role for the social ... [more ▼]

The quality of interactions experienced with primary attachment figures influence the development of emotional skills. On the other hand, we know how emotions fill a critical adaptive role for the social adjustment, in that they assume both a communicative function and an informative value. In this research, we were particularly interested in how children’s patterns of attachment were expressed in terms of emotional regulation abilities. According to Laible & Thompson’s observations (1998), we tested the following hypothesis: insecure attachment representations are associated with a poverty of skills in decoding emotional signals. They especially would affect the perception of negative emotional expressions. We tested this hypothesis by the meeting of five children of primary school age (5 to 8 years old) with a reactive attachment disorder and through the establishment of two methodological tools. At first, the Attachment Story Completion Task (Bretherton et al., 1990) allowed us to identify attachment representations for each child. Secondly, inspired by Pollak & al.’s study, we developed a recognition task of facial emotional expressions. We observed in these children low average rates of identification of basic and primary emotions. Especially, the accuracy of judgments was not only a function of emotion’s valence, but was also dependant of the child’s attachment pattern. Finally, this research confirmed the observations, already showed in previous studies, that interpersonal difficulties presented by these children could be explained specifically by their inefficiency in interpreting social cues surrounding emotional events (Crick & Dodge, 1994). [less ▲]

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See detailReactive blending of functional PS and PMMA: interfacial behavior of in situ formed graft copolymers
Yin, Zhihui; Koulic, Christian; Pagnoulle, Christophe et al

in Macromolecules (2001), 34(15), 5132-5139

ω-Isocyanate PMMA, α-anhydride PMMA, and PS-co-PSNH2 have been prepared by atom transfer radical polymerization (ATRP) with controlled molecular weights (104 and 3.5 × 104) and low polydispersity (1.2 ... [more ▼]

ω-Isocyanate PMMA, α-anhydride PMMA, and PS-co-PSNH2 have been prepared by atom transfer radical polymerization (ATRP) with controlled molecular weights (104 and 3.5 × 104) and low polydispersity (1.2). They have been used as precursors of PS-g-PMMA copolymers and let to react in the melt (170 °C, for 10 min) under moderate shear rate. The well-controlled molecular characteristics of these precursors are a substantial advantage to study the effect of the kinetics of the interfacial reaction on the phase morphology. When the grafting reaction is fast (NH2/anhydride pair) and low molecular weight chains are used, the interfacial reaction is quasi-complete and a nanophase morphology is observed, whereas limited reaction and formation of microphases are observed in all the other cases. A high reaction yield requires not only that the functional groups are highly mutually reactive but also that the interface is anytime made available to the functional polymers for the reaction to progress. Then, a nanophase morphology may be observed, which is that of the copolymer formed by the interfacial reaction. A low reaction yield is dictated by either a slow interfacial reaction or a slow diffusion of the copolymer away from the interface. In the latter case, the phases formed by the unreacted precursors are stabilized by the copolymer which resides at the interface. [less ▲]

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See detailReactive compatibilization of PC/PVDF polymer blends by zinc carboxylate containing poly(methylmethacrylate)ionomers
Moussaif, Noureddine; Pagnoulle, Christophe; Jérôme, Robert ULg

in Polymer (2000), 41(15), 5551-5562

Polycarbonate (PC) has been reacted with a random copolymer of methylmethacrylate and 6 mol% of acrylic acid (poly(MMA-co-AA)) and with this copolymer neutralized (totally or not) by Zn cations. When ... [more ▼]

Polycarbonate (PC) has been reacted with a random copolymer of methylmethacrylate and 6 mol% of acrylic acid (poly(MMA-co-AA)) and with this copolymer neutralized (totally or not) by Zn cations. When conducted in solution at 240°C, the reaction leads to the grafting of PC onto the copolymer neutralized or not. In the melt at 235°C, the grafting reaction occurs only when the copolymer is at least partly neutralized. Whatever the experimental conditions (solution or bulk), PMMA does not react with PC, which confirms that the acidolysis of PC is at the origin of the grafting reaction. Poly(vinylidene fluoride) (PVDF) and PC have been melt blended at 235°C in the presence of the poly(MMA-co-AA) copolymer totally neutralized or not by Zn cations, the purpose being the reactive formation of PMMA-g-PC copolymer that would act as compatibilizer for the PC/PVDF blend. The phase morphology and the mechanical properties of the compatibilized PC/PVDF blends have been compared with the parent non-reactive polyblends. Compared to the modification of PVDF by 20 wt% of PMMA, the use of 20 wt% of the partly neutralized poly(MMA-co-AA) copolymer decreases further the average size of the dispersed phase, enhances its adhesion to the matrix, and results in a considerable increase of the elongation at break. The beneficial effect of zinc carboxylate in the PMMA copolymer is explained by the grafting of PC onto PMMA at the interface. [less ▲]

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See detailReactive compatibilization of SAN/EPR blends. 1. Dependence of the phase morphology development on the reaction kinetics
Pagnoulle, Christophe; Koning, Cor; Leemans, Luc et al

in Macromolecules (2000), 33(17), 6275-6283

SAN containing 20 wt % of reactive SAN-X has been melt blended with EPDM containing 50 wt % of EP chains grafted by maleic anhydride (EP-g-MA). Two types of reactive groups (X) have been attached to SAN ... [more ▼]

SAN containing 20 wt % of reactive SAN-X has been melt blended with EPDM containing 50 wt % of EP chains grafted by maleic anhydride (EP-g-MA). Two types of reactive groups (X) have been attached to SAN (2 mol % of X), i.e., a primary amine and a precursor of it at the processing temperature, i.e., a carbamate. The SAN/rubber weight composition was kept constant at 75/25. The development of the phase morphology from pellet-sized rubber particles to dispersed submicrometer droplets has been investigated during reactive mixing for the two types of reactive SAN and has been found to depend on the interpolymer reaction rate and thus on the relative reactivity of the amine and the carbamate groups attached to SAN toward the maleic anhydride function of EP. [less ▲]

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See detailReactive compatibilization of SAN/EPR blends. 2. Effect of type and content of reactive groups randomly attached to SAN
Pagnoulle, Christophe; Jérôme, Robert ULg

in Macromolecules (2001), 34(4), 965-975

Kinetics of the poly(styrene-co-acrylonitrile)/poly(ethylene-co-propylene) (SAN/EPR) interfacial reaction has been varied by changing both the average number of reactive groups per SAN chain and the ... [more ▼]

Kinetics of the poly(styrene-co-acrylonitrile)/poly(ethylene-co-propylene) (SAN/EPR) interfacial reaction has been varied by changing both the average number of reactive groups per SAN chain and the content of reactive SAN in the SAN phase, while keeping constant the overall SAN/EPR composition, i.e., 75/25 w/w. For this purpose, reactive SAN chains containing 0.004, 0.028, 0.049, and 0.078 mol/wt % of either primary amine or carbamate (an amine precursor) have been synthesized, and the content of reactive SAN in the SAN phase has been changed from 2.5 to 73.33 wt %. It appears that the number and type of reactive groups attached onto SAN affect not only the extent of the compatibilization reaction but also the compatibilization capability of the in situ formed graft copolymer in a strong dependence on molecular weight and molecular architecture. [less ▲]

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See detailReactive compatibilization of SAN/EPR blends: Effect of kinetics of the compatibilization reaction on the interfacial adhesion
Pagnoulle, Christophe; Jérôme, Robert ULg

in Macromolecular Symposia (2000), 149

The very poor adhesion between films of styrene and acrylonitrile random copolymer (SAN) and maleic anhydride grafted polypropylene (PP-g-MA) can be dramatically improved by an intermediate thin layer of ... [more ▼]

The very poor adhesion between films of styrene and acrylonitrile random copolymer (SAN) and maleic anhydride grafted polypropylene (PP-g-MA) can be dramatically improved by an intermediate thin layer of SAN bearing groups reactive toward maleic anhydride. The rate of the interfacial reaction, which is controlled by the reactive groups attached to SAN (amine vs. carbamate) and by the method used to build up the sandwich assembly, has a decisive effect on the capability of the SAN-g-PP graft copolymer formed at the interface to improve the fracture toughness in direct dependence on its molecular architecture. [less ▲]

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See detailReactive compatibilization of SAN/EPR blends: Effect of rubber content and reactivity of the SAN functional groups
Pagnoulle, Christophe; Martin, Philippe; Jérôme, Robert ULg

in Macromolecular Chemistry and Physics (2000), 201(16), 2181-2194

SAN containing 20 wt.-% reactive SAN-X was melt blended with EPDM containing 50 wt.-% maleic anhydride EPR grafted chains (EP-g-MA). The rubber content was changed from 15 to 80 wt.-%, and 2 types of ... [more ▼]

SAN containing 20 wt.-% reactive SAN-X was melt blended with EPDM containing 50 wt.-% maleic anhydride EPR grafted chains (EP-g-MA). The rubber content was changed from 15 to 80 wt.-%, and 2 types of reactive groups (X) were attached to SAN (0.028 mol X/ wt.-%), i. e. primary amines and carbamates which are primary amine precursors at the processing temperature. Phase morphology, tensile properties and impact strength depend not only on the rubber content but also on the relative reactivity of the amine and the carbamate groups towards maleic anhydride, in a strong dependence on the reaction rate and the reaction completeness. The dispersion mechanism has been discussed, including formation of sub-inclusions. Dependence of the impact resistance on the rubber phase content for non-reactive blends (□) and blends modified by SAN-NH2 (;) and SAN-carb (o), respectively. [less ▲]

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See detailReactive Oxygen Intermediate-Dependent Nf-Kappab Activation by Interleukin-1beta Requires 5-Lipoxygenase or Nadph Oxidase Activity
Bonizzi, Giuseppina; Piette, Jacques ULg; Haterte, Stéphanie ULg et al

in Molecular & Cellular Biology (1999), 19(3), 1950-60

We previously reported that the role of reactive oxygen intermediates (ROIs) in NF-kappaB activation by proinflammatory cytokines was cell specific. However, the sources for ROIs in various cell types are ... [more ▼]

We previously reported that the role of reactive oxygen intermediates (ROIs) in NF-kappaB activation by proinflammatory cytokines was cell specific. However, the sources for ROIs in various cell types are yet to be determined and might include 5-lipoxygenase (5-LOX) and NADPH oxidase. 5-LOX and 5-LOX activating protein (FLAP) are coexpressed in lymphoid cells but not in monocytic or epithelial cells. Stimulation of lymphoid cells with interleukin-1beta (IL-1beta) led to ROI production and NF-kappaB activation, which could both be blocked by antioxidants or FLAP inhibitors, confirming that 5-LOX was the source of ROIs and was required for NF-kappaB activation in these cells. IL-1beta stimulation of epithelial cells did not generate any ROIs and NF-kappaB induction was not influenced by 5-LOX inhibitors. However, reintroduction of a functional 5-LOX system in these cells allowed ROI production and 5-LOX-dependent NF-kappaB activation. In monocytic cells, IL-1beta treatment led to a production of ROIs which is independent of the 5-LOX enzyme but requires the NADPH oxidase activity. This pathway involves the Rac1 and Cdc42 GTPases, two enzymes which are not required for NF-kappaB activation by IL-1beta in epithelial cells. In conclusion, three different cell-specific pathways lead to NF-kappaB activation by IL-1beta: a pathway dependent on ROI production by 5-LOX in lymphoid cells, an ROI- and 5-LOX-independent pathway in epithelial cells, and a pathway requiring ROI production by NADPH oxidase in monocytic cells. [less ▲]

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See detailReactive oxygen species downregulate the expression of pro-inflammatory genes by human chondrocytes.
Mathy, Marianne ULg; Martin, G.; Devel, P. et al

in Inflammation Research (2003), 52(3), 111-8

OBJECTIVES: To determine the regulatory effects of reactive oxygen species (ROS) on the expression by human osteoarthritic chondrocytes of interleukin (IL)-1beta, -6 and -8, inducible nitric oxide ... [more ▼]

OBJECTIVES: To determine the regulatory effects of reactive oxygen species (ROS) on the expression by human osteoarthritic chondrocytes of interleukin (IL)-1beta, -6 and -8, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene in response to interleukin (IL)-1beta or lipopolysaccharide (LPS). METHODS: Human chondrocytes in monolayer culture were incubated for 3 h with ROS generating molecules such as S-nitroso-N-acetyl-D,L-penicillamine (SNAP, 100 microM), 3-morpholinosydnonimine (SIN-1, 100 microM), with chemically synthesised peroxynitrite (ONOO-, 10 microM) or hydrogen peroxide (H2O2, 100 microM). After treatment by ROS, chondrocytes were washed and then cultured for the next 24 h with or without lipopolysaccharide LPS (10 microg/ml) or IL-1beta (1.10(-11) M). IL-1beta, IL-6, IL-8, iNOS and COX-2 gene expression was analysed by real time and quantitative RT PCR. IL-6, IL-8 and prostaglandin (PG) E2 productions were assayed by specific immunoassays. Nitrite was measured in the culture supernatants by the Griess procedure. RESULTS: LPS and IL-1beta stimulated IL-1beta, IL-6, IL-8, iNOS and COX-2 gene expression. SNAP significantly downregulated LPS induced overall gene expressions, whereas SIN-1 had no effect. ONOO- inhibited iNOS and COX-2 gene expression but not that of the cytokine genes. When chondrocytes were incubated with IL-1beta, SIN-1 and ONOO dramatically decreased all gene expressions while SNAP was inefficient. H2O2 treatment inhibited both LPS and IL-1beta induced gene expressions. CONCLUSIONS: These data provide an evidence that ROS may have anti-inflammatory properties by depressing inflammatory gene expression. Further, we demonstrate that ROS effects are dependent on the nature of radical species and the signalling pathway that is activated. These findings should be taken into consideration for the management of antioxidant therapy in treatment of inflammatory joint diseases. [less ▲]

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See detailReactive oxygen species downregulate the expression of pro-inflammatry genes by humachondrocytes
Henrotin, Yves ULg; Mathy-Hartert, Marianne ULg; Martin, G. et al

in Osteoporosis International (2002, November), 13(Suppl. 3), 53

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See detailReactive transport modelling of a groundwater contamination by ammoniacal liquor
Haerens, Bruno; Prommer, Henning; Lerner, David N. et al

(2006)

A reactive transport modeling study was carried out to assess the fate of a groundwater contamination by ammoniacal liquor from a former coking plant and the associated geochemical response. The ... [more ▼]

A reactive transport modeling study was carried out to assess the fate of a groundwater contamination by ammoniacal liquor from a former coking plant and the associated geochemical response. The simulations over a 45-year period provide a conclusive explanation and quantitative description of all measured data from observation wells down gradient of the contaminant source. It is shown that cation exchange exerts the main control on the fate of the ammonium plume as it strongly retards the migration of dissolved ammonium. The sorption of ammonium is accompanied by the elution of native cations, an effect that can be seen in some observation wells where ammonium is absent. While phenol has not been detected in the observation wells in recent years, the modeling results suggest that it has completely degraded in the aquifer, which is inferred from the agreement between the simulated and the observed geochemical fingerprint that the degradation of phenol imposes on groundwater composition. [less ▲]

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See detailReactive transport modelling of Ammonium: 1D Conceptual modelling and comparison of reactive transport codes
Haerens, Bruno; Dassargues, Alain ULg; Lerner, David

in Acta Universitatis Carolinae. Geologica (2002), 46(2-3), 27-31

Contamination of NH4+, as main inorganic contaminant, resulted from disposal of ammoniacal liquor at a former coal carbonisation plant at Mansfield, UK. Previous research for evaluating natural ... [more ▼]

Contamination of NH4+, as main inorganic contaminant, resulted from disposal of ammoniacal liquor at a former coal carbonisation plant at Mansfield, UK. Previous research for evaluating natural attenuation (Davison, 1998; Davison and Lerner, 2000; Jones, 2001; Jones et al., 1998; Jones and Lerner, 2001) revealed strong retardation of NH4+ in the aquifer due to cation exchange with existing cations on the sediment. After disposal of ammoniacal liquor, NH4+ entered the aquifer and equilibrium took place between NH4+, the existing cations and the available exchange sites. An existing hydraulic gradient keeps flushing the contaminated aquifer with pristine background water. NH4+ desorbs progressively due to new cation exchange equilibrium when the input of NH4+ decreases or eventually stops. In order to be able to model the reactive transport of NH4+, a reaction module is set up for future 2D/3D reactive transport modelling of NH4+ using PHT3D. In a first approach a conceptual 1D-model example is considered and two multicomponent reactive transport models, PHT3D (Prommer and Barry, 2001; Prommer et al., 1999) and PHREEQC (Parkhurst and Appelo, 1999), are compared. In the 1D-model example, the flushing of ammonium contaminated groundwater by pristine background water is simulated. The included processes are advection, dispersion and cation exchange between NH4+, Ca2+, Mg2+, K+, Na+ and the sediment. As both models are using the same geochemical module, the comparison focuses on the coupling approach between the transport and geochemical modules. Results show that large numbers of pore volumes (i.e., a nondimensional time parameter where elapsed time is divided by the hydrodynamic residence time (Brusseau, 1994)) are needed to flush the NH4+ off the aquifer sediment. From the comparison of simulation results compiled with the two codes it is clear that an appropriate choice of the reaction step size for the sequential coupling between the transport and geochemistry modules, is a major point for accuracy of the model predictions. [less ▲]

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See detailReactively and physically compatibilized immiscible polymer blends: Stability of the copolymer at the interface
Harrats, Charef; Dedecker, Kristof; Groeninckx, Gabriel et al

in Macromolecular Symposia (2003), 198

This paper reports on the interfacial behaviour' of block and graft copolymers used as compatibilizers in immiscible polymer blends. A limited residence time of the copolymer at the interface has been ... [more ▼]

This paper reports on the interfacial behaviour' of block and graft copolymers used as compatibilizers in immiscible polymer blends. A limited residence time of the copolymer at the interface has been shown in both reactive blending and blend compatibilization by preformed copolymers. Polystyrene (PS)/polyamide6 (PA6), polyphenylene oxide (PPO)/ PA6 and polymethylmethaciylate (PMMA)/PA6 blends have . been reactively compatibilized by a styrene-maleic anhydride copolymer SMA. The extent of miscibility of SMA with PS, PPO and PMMA is a key criterion for the stability of the graft copolymer' at the interface. For the first 10 to 15 minutes of mixing, the in situ formed copolymer is able to decrease the particle size of the dispersed phase and to prevent it from coalescencing. However, upon increasing mixing time, the copolymer leaves the interface which results in phase coalescence. In PS/LDPE blends compatibilized by preformed PS / hydrogenated polybutadiene (hPB) block copolymers, a tapered diblock stabilizes efficiently a co-continuous two-phase morphology, in contrast to a triblock copolymer that was unable to prevent phase coarsening during annealing at 180°C for 150 minutes. [less ▲]

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