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See detailIntermediate integer programming representations using value disjunctions
Louveaux, Quentin ULg

Conference (2006, January)

We introduce a general technique for creating an extended formulation of a mixed-integer program. We classify the integer variables into blocks, each of which generates a finite set of vector values. The ... [more ▼]

We introduce a general technique for creating an extended formulation of a mixed-integer program. We classify the integer variables into blocks, each of which generates a finite set of vector values. The extended formulation is constructed by creating a new binary variable for each generated value. Initial experiments show that the extended formulation can have a more compact complete description than the original formulation. We prove that, using this reformulation technique, the facet description decomposes into one “linking polyhedron” per block and the “aggregated polyhedron”. Each of these polyhedra can be analyzed separately. For the case of identical coefficients in a block, we provide a complete description of the linking polyhedron and a polynomial-time separation algorithm. Applied to the knapsack with a fixed number of distinct coefficients, this theorem provides a complete description in an extended space with a polynomial number of variables. On the basis of this theory, we propose a new branching scheme that analyzes the problem structure. It is designed to be applied in those subproblems of hard integer programs where LP-based techniques do not provide good branching decisions. Preliminary computational experiments show that it is successful for some benchmark problems of multi-knapsack type. [less ▲]

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See detailA unified extended thermodynamic description of diffusion, thermo-diffusion, suspensions, and porous media
Lebon, Georgy ULg; Desaive, Thomas ULg; Dauby, Pierre ULg

in Journal of Applied Mechanics-Transactions of the Asme (2006), 73(1), 16-20

It is shown that extended irreversible thermodynamics (EIT) provides a Unified description of a great variety of processes, including matter diffusion, thermo-diffusion, suspensions, and fluid flows in ... [more ▼]

It is shown that extended irreversible thermodynamics (EIT) provides a Unified description of a great variety of processes, including matter diffusion, thermo-diffusion, suspensions, and fluid flows in porous media. This is achieved by enlarging the set of classical variables, as mass, momentum and temperature by the corresponding fluxes of mass, momentum and heat. For simplicity, we consider only Newtonian fluids and restrict ourselves to a linear analysis: quadratic and higher order terms in the fluxes are neglected. In the case of diffusion in a binary mixture, the extra flux variable is the diffusion flux of one the constituents, say the solute. In thermo-diffusion, one adds the heat flux to the set of variables. The main result of the present approach is that the traditional equations of Fick, Fourier Soret, and Dufour are replaced by time-evolution equations for the matter and heat fluxes, such generalizations are useful in high-frequency processes. It is also shown that the analysis can be easily extended to the study of particle suspensions in fluids and to flows in porous media, when such systems can be viewed as binary mixtures with a solid and a fluid component. [less ▲]

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See detailLe cas clinique du mois. Necrose du cuir chevelu revelatrice d'une arterite a cellules geantes (maladie de Horton)
Smitz, S. S.; HEINEN, Vincent ULg; Van Damme, Hendrik ULg

in Revue Médicale de Liège (2006), 61(1), 5-7

Scalp necrosis is an uncommon manifestation of giant cell arteritis (GCA). In this paper, we report our experience with a 78-year old woman in whom extensive scalp necrosis developed as a complication of ... [more ▼]

Scalp necrosis is an uncommon manifestation of giant cell arteritis (GCA). In this paper, we report our experience with a 78-year old woman in whom extensive scalp necrosis developed as a complication of GCA. A left frontal defect (7 X 4 cm) involving full-thickness scalp was observed. The necrosis extended deeply, involving the epicranium and the outer table of the skull. The therapeutic approach included corticotherapy, anticoagulation and wound care. Severe wound infection (osteitis, subgaleal abscess) occurred, requiring prolonged antibiotherapy. Second intention healing was obtained using a conservative approach. During the healing process, areas of neovascularization developed beneath the exposed part of the outer table and the necrotic bone underwent resorption. [less ▲]

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See detailEffects of aripiprazole on serum lipids, a comparison with patients started on statin
Hanssens, L.; De Hert, M.; Van Eyck, D. et al

in Schizophrenia Research (2006, January), 81(Suppl. S), 135

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See detailCysteinyl-leukotrienes contribute to sputum eosinophil chemotactic activity in asthmatics
Hemelaers, L.; Henket, Monique ULg; Sele, Jocelyne ULg et al

in Allergy (2006), 61(1), 136-139

Background: Cysteinyl-leukotrienes are lipid derived mediators involved in asthma. They are able to stimulate eosinophil chemotaxis in vitro. Induced sputum from asthmatics has been shown to contain ... [more ▼]

Background: Cysteinyl-leukotrienes are lipid derived mediators involved in asthma. They are able to stimulate eosinophil chemotaxis in vitro. Induced sputum from asthmatics has been shown to contain eosinophil chemotactic activity. The purpose of our study was to evaluate the contribution of cysteinyl-leukotrienes to sputum eosinophil chemotactic activity in asthmatics and to seek whether there might be differences between asthmatics free of inhaled corticosteroids vs those regularly receiving this treatment. Methods: Twenty-two patients (11 corticosteroid free, mean FEV1 99% predicted, 11 corticosteroid-treated, mean FEV1 77% predicted) recruited from our asthma clinic underwent a sputum induction. Sputum was processed according to standard procedure. Eosinophil chemotactic activity contained in the fluid phase was assessed using Boyden microchamber model and expressed as chemotaxis index (CI). Cysteinyl-leukotrienes were measured in sputum supernatant by ELISA and their role in sputum eosionophil chemotactic activity was evaluated by using montelukast, a selective antagonist of a cys-LT1 receptor. Results: Cysteinyl-leukotrienes were well detectable in sputum supernatants from both steroid-naive (247 +/- 42 pg/ml) and steroid-treated (228 +/- 26 pg/ml) asthmatics. Sputum eosinophil chemotactic activity was indiscriminately present in both corticosteroid-naive (CI: 2.61 +/- 0.22) and corticosteroid-treated (2.98 +/- 0.35) asthmatics. Montelukast (100 mu M) significantly inhibited the eosinophil chemotactic activity in both groups achieving a mean inhibition of 54.2 +/- 9.2% (P < 0.001) and 64.7 +/- 7.8% (P < 0.001) in steroid-naive and steroid-treated asthmatics respectively. Conclusion: Cysteinyl-leukotrienes actively participate in sputum eosinophil chemotactic activity found in asthmatics irrespective of whether they are or not under treatment with inhaled corticoids. [less ▲]

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See detailEditorial 2006 : le RMLg entre dans la 7e décénnie
Kulbertus, Henri ULg; Giet, Didier ULg

in Revue Médicale de Liège (2006), 61(1), 1-2

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See detailImpact assessment and remediation of anthropogenic interventions on fish populations - (FISHGUARD)
DeBoeck, Gudrun; Blust, Ronny; Todorache, Christian et al

Report (2006)

The disruption of longitudinal river connectivity by man-made obstacles and the stocking of fish communities with non-indigenous species or genotypes threaten the fish fauna of Belgian rivers to various ... [more ▼]

The disruption of longitudinal river connectivity by man-made obstacles and the stocking of fish communities with non-indigenous species or genotypes threaten the fish fauna of Belgian rivers to various extents. Obstacles impede migrations between habitats that are vital for populations, and they may restrict the gene flow between populations, thereby reducing the effective size and genetic diversity of populations and increasing the risk of local extinction. Restocking programs often involve the introduction of non-indigenous genotypes in native populations. Moreover, although stocking programs lead to the temporal and superficial enrichment of local fish communities or gene pools, they generally result in a loss of biodiversity on a regional or international scale through the homogenisation of communities and the breakdown of genetic differentiation between populations. Thus, stocking programs cannot compensate for the loss of free migration by artificial obstructions. The impact of these changes on fish populations remains largely unknown, which complicates the priorisation of spots to preserve and spots to restore. Here, we present an integrated study on Belgian waters, both in Flanders and Wallonia, which analyses fish communities, gene flow and migration patterns in the field, as well as the swimming and leaping performances of fishes under controlled conditions. [less ▲]

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See detailCytokine production from sputum cells in eosinophilic versus non-eosinophilic asthmatics
Quaedvlieg, Valérie ULg; Henket, Monique ULg; Sele, Jocelyne ULg et al

in Clinical & Experimental Immunology (2006), 143(1), 161-166

The inflammatory pathways involved in asthma are more complex than the sole Th2-mediated eosinophilic airway inflammation. Different phenotypes of asthma have been recently highlighted and are probably ... [more ▼]

The inflammatory pathways involved in asthma are more complex than the sole Th2-mediated eosinophilic airway inflammation. Different phenotypes of asthma have been recently highlighted and are probably underlied by different immunological profiles. The aim of the study was to assess cytokine production from sputum cells in eosinophilic versus non-eosinophilic asthmatics. Induced sputum was obtained from 48 consecutive stable mild to moderate asthmatics (20 eosinophilic asthmatics, 28 non-eosinophilic asthmatics) and 31 healthy subjects. Cytokine released from sputum cells were measured by a home-made two-step sandwich immunoassay. Cytokines investigated were interleukin (IL)-4, IL-6, IL-10, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma. Sputum cells from eosinophilic asthmatics produced more IL-4 than those from both healthy subjects (P < 0.05) and non-eosinophilic asthmatics (P < 0.05). Conversely, sputum cells from eosinophilic asthma were found to release lower amounts of TNF-alpha than those from healthy subjects (P < 0.05). The group of non-eosinophilic asthmatics did not distinguish from healthy subjects with respect to any cytokines measured. Sputum cells from asthmatics exhibiting eosinophilic airway inflammation release more IL-4 and less TNF-alpha than those of healthy subjects. By contrast, non-eosinophilic asthmatics did not distinguish from healthy subjects by abnormal cytokine release from their sputum cells. [less ▲]

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See detail192-Ir or 125-I Prostate Brachytherapy as a Boost to External Beam Radiotherapy in Locally Advanced Prostatic Cancer: A Dosimetric Point of View
Nickers, Philippe ULg; Thissen, Benedicte ULg; Jansen, Nicolas ULg et al

in Radiotherapy & Oncology (2006), 78(1), 47-52

PURPOSE: This work aims at comparing the dosimetric possibilities of 125I or 192Ir prostate brachytherapy (Bt) as a boost to external beam radiotherapy in the treatment of locally advanced adenocarcinoma ... [more ▼]

PURPOSE: This work aims at comparing the dosimetric possibilities of 125I or 192Ir prostate brachytherapy (Bt) as a boost to external beam radiotherapy in the treatment of locally advanced adenocarcinoma. METHODS AND MATERIALS: From 1/1997 to 12/2002, 260 patients were treated. Until 12/2001 a low dose rate (LDR) treatment with 192Ir wires was used, later replaced by a high dose rate (HDR) delivered with an 192Ir stepping source technology. For the present work, we selected 40 patients including the last 20 treated, respectively, by LDR and HDR. The planning CT Scans of all these 40 patients were transferred into the 3D Prowess system for 125I permanent implants design according to the Seattle method. The reference data for dosimetric comparisons were the V100 and the prescribed dose for 192Ir as well as the dose delivered with 125I techniques to the 192Ir V100. We compared V100-150 data as well as doses to the organs at risks (OR) and cold spots (CS). RESULTS: The V100 is 85.3+/-8% for 192Ir LDR and 96+/-2% for HDR techniques (P < 0.0001). In comparison with 125I, the 192Ir LDR mode induces higher hyperdosage volumes inside the CTV but also more CS, while maximal doses to urethra and rectum are, respectively, 17 and 39% less with 125I (P < 0.0001). In comparison with the 192Ir HDR mode, 125I Bt induces higher hyperdosage volumes and slightly more CS deliberately planned around the bladder neck. If delivered doses to urethra are identical, those to the 20% anterior part of the rectum are 33% less with 125I (P < 0,0001). The 125I Bt technique was only possible in 24 out of the 40 patients studied due to pelvic bone arch interference. CONCLUSIONS: At the present time, there is no evident dosimetric superiority of one Bt method when all the criteria are taken into account. However, improving Bt techniques to implant any prostatic size could found the superiority of the 125I or permanent implants. 125I indeed allows large hyperdosage volumes inside the CTV in comparison with 192Ir HDR techniques while lowering doses to OR and minimizing CS. [less ▲]

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See detailA cross-sectional study of adiponectin in patients with schizophrenia
Hanssens, L.; De Hert, M.; Van Eyck, D. et al

in Schizophrenia Research (2006, January), 81(Suppl. S), 135

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See detailChemical interactions between Bi2Sr3CaO7(Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy))
Rahier, Sébastien ULg; Lafort, Adeline ULg; Henrist, Catherine ULg et al

in Superconductor Science & Technology (2006), 19(1), 39-43

The chemical interactions between Bi2Sr3CaO7 (Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy)) at 965 degrees C were investigated by means of: (i) an interdiffusion couple and (ii) layers deposited by dip ... [more ▼]

The chemical interactions between Bi2Sr3CaO7 (Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy)) at 965 degrees C were investigated by means of: (i) an interdiffusion couple and (ii) layers deposited by dip coating on oxidized nickel Substrates. The samples were characterized by optical and electron microscopies, energy-dispersive x-ray (EDX) analysis and x-ray diffraction. It turns out that at the peritectic temperature Of Bi-2212(Dy), the Bi-2310 phase reacts with the liquid phase resulting from the peritectic decomposition of the Bi-2212(Dy) phase. Dissolution of Bi-2310 leads to an enrichment in Sr and an impoverishment in Cu of the liquid phase, resulting in a shift of the composition of the insoluble phase towards the Ca-rich end of the (Ca, Sr)O Solid Solution. [less ▲]

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See detailLe monoxyde d'azote exhale: un nouveau biomarqueur des pathologies respiratoires
HEINEN, Vincent ULg; Claeys, Mathieu ULg; Louis, Renaud ULg

in Revue Médicale de Liège (2006), 61(1), 37-42

There has been a growing interest for exhaled biomarkers. We review studies examining NO as a potential marker of airway inflammation, enabling noninvasive repeated monitoring of airway inflammation. The ... [more ▼]

There has been a growing interest for exhaled biomarkers. We review studies examining NO as a potential marker of airway inflammation, enabling noninvasive repeated monitoring of airway inflammation. The measurement technique has been standardized. We have determined the local normal levels for the Liege region. The exhaled NO level is elevated in asthma, and can predict asthma exacerbation. Exhaled NO has a value for the diagnosis of cystic fibrosis and primary ciliary dyskinesia. [less ▲]

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See detailPoly (D,L-lactic acid) macroporous guidance scaffolds seeded with Schwann cells genetically modified to secrete bi-functional neurotrophin implanted in the completely transected adult rat thoracic spinal cord
Hurtado, Andres; Moon, Lawrence D F; Maquet, Véronique et al

in Biomaterials (2006), 27(3), 430-442

Freeze-dried poly(D,L-lactic acid) macroporous scaffold filled with a fibrin solution containing Schwann cells (SCs) lentivirally transduced to produce and secrete D15A, a bi-functional neurotrophin with ... [more ▼]

Freeze-dried poly(D,L-lactic acid) macroporous scaffold filled with a fibrin solution containing Schwann cells (SCs) lentivirally transduced to produce and secrete D15A, a bi-functional neurotrophin with brain-derived neurotrophic factor and neurotrophin-3 activity, and to express green fluorescent protein (GFP) were implanted in the completely transected adult rat thoracic spinal cord. Control rats were similarly injured and then implanted with scaffolds containing the fibrin solution with SCs lentivirally transduced to produce express GFP only or with the fibrin solution only. Transgene production and biological activity in vitro, SC survival within the scaffold in vitro and in vivo, scaffold integration, axonal regeneration and myelination, and hind limb motor function were analyzed at 1, 2, and 6 weeks after implantation. In vitro, lentivirally transduced SCs produced 87.5 ng/24 h/10(6) Cells of D15A as measured by neurotrophin-3 activity in ELISA. The secreted D15A was biologically active as evidenced by its promotion of neurite outgrowth of dorsal root ganglion neurons in culture. In vitro, SCs expressing GFP were present in the scaffolds for up to 6 It, the end of a typical surgery session. Implantation of SC-seeded scaffolds caused modest loss of spinal nervous tissue. Reactive astrocytes and chondroitin sulfate glycosaminoglycans were present in spinal tissue adjacent to the scaffold. Vascularization of the scaffold was ongoing at I week post-implantation. There were no apparent differences in scaffold integration and blood vessel formation between groups. A decreasing number of implanted (GFP-positive) SCs were found within the scaffold during the first 3 days after implantation. Apoptosis was identified as one of the mechanisms of cell death. At 1 week and later time points after implantation, few of the implanted SCs were present in the scaffold. Neurofilament-positive axons were found in the scaffold. At 6 weeks post-grafting, myelinated axons were observed within and at the external surface of the scaffold. Axons did not grow from the scaffold into the caudal cord. All groups demonstrated a similar improvement of hind limb motor function. Our findings demonstrated that few seeded SCs survived in vivo, which could account for the modest axonal regeneration response into and across the scaffold. For the development of SC-seeded macroporous scaffolds that effectively promote axonal regeneration in the injured spinal cord, the survival and/or total number of SCs in the scaffold needs to be improved. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailStatin therapy among schizophrenia patients with dyslipidemia
Wampers, M.; De Hert, M.; Hanssens, L. et al

in Schizophrenia Research (2006, January), 81(Suppl. S), 141

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See detailUse of x-ray microtomography to visualise dynamic adsorption of organic vapour and water vapour on activated carbon
Lodewyckx, Peter; Blacher, Silvia ULg; Léonard, Angélique ULg

in Adsorption (2006), 12(1), 19-26

X-ray microtomography coupled with image analysis was used to quantify the adsorption of vapours on activated carbon beds. This technique was tested using three different challenges: CCl4, water vapour ... [more ▼]

X-ray microtomography coupled with image analysis was used to quantify the adsorption of vapours on activated carbon beds. This technique was tested using three different challenges: CCl4, water vapour and a mixture of water- and organic vapour. It is shown that the used technique allows determining the adsorption front progress in the case of organic vapour and mixture of water and organic vapour whereas the existence of this front was not so obvious in the case of water vapour. Experimental results obtained for organic vapours were interpreted on the basis of the Wheeler-Jonas equation: a good agreement was found between experimental and theoretical breakthrough times. [less ▲]

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See detailEt Liège demain-carte blanche
Marchal, Jean ULg

in Gagner et Réussir (2006)

Réflexions sur le thème du développement du bassin liégeois. Son expérience dans les domaines de la mobilité et de la logistique est un atout pour notre province, sa compétence reconnue en Europe et dans ... [more ▼]

Réflexions sur le thème du développement du bassin liégeois. Son expérience dans les domaines de la mobilité et de la logistique est un atout pour notre province, sa compétence reconnue en Europe et dans le monde fait du professeur Marchal un témoin privilégié. [less ▲]

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See detailConséquences de la désertification
Ozer, Pierre ULg

Article for general public (2006)

La désertification est indissociablement liée à la pauvreté. Un sol épuisé prive le pays de sa capacité de résister à la sécheresse ou au surpâturage. Les récoltes enregistrent une baisse dramatique, qui ... [more ▼]

La désertification est indissociablement liée à la pauvreté. Un sol épuisé prive le pays de sa capacité de résister à la sécheresse ou au surpâturage. Les récoltes enregistrent une baisse dramatique, qui engendre la sous-alimentation, la faim et encore plus de pauvreté. Le déclin de l’environnement joue aussi un rôle dans l’émergence de conflits et de l’agitation sociale, et vice-versa. Et, une fois de plus, ce sont les plus démunis qui écopent. [less ▲]

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