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See detail(Ex)communication
Dumortier, Jean-Louis ULg

in Lettre de la DLFM (2003), 32

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See detail(Ex-)smoking asthma patients in general and specialized Belgian practice.
Decramer, M.; Louis, Renaud ULg; Joos, G. et al

in Respiratory medicine (2011), 105(8), 1203-1210

INTRODUCTION: Smokers are often excluded from asthma studies. In the present study, data are presented on the prevalence, characteristics and management approach of this patient population in the Belgian ... [more ▼]

INTRODUCTION: Smokers are often excluded from asthma studies. In the present study, data are presented on the prevalence, characteristics and management approach of this patient population in the Belgian practice both at the level of general practitioners (GPs) and specialists. MATERIALS AND METHODS: One hundred and nineteen smoking, non-smoking and ex-smoking patients (25-65 yrs) with asthma, COPD or both, were recruited by 33 GPs and 33 specialists. Data were obtained retrospectively from medical records. However, only a small number of files were complete. RESULTS: The majority of COPD patients were (ex-)smokers: 94% in the specialist group, 78% in the GP group. Cardiovascular comorbidity appeared in both groups in the same frequency order: COPD>(ex-)smoking patients with asthma (AS)>non-smoking patients with asthma (ANS), with a significant difference between AS and ANS in the specialist population. Chronic cough during more than 3 months in two consecutive years was reported in 97% of COPD patients, in 71% of the AS patients and in only 25% of the ANS patients. The type of cough differed between AS and ANS in the GP group, with a higher prevalence of productive cough in the former. Treatment patterns observed were as expected according to diagnosis except for a disproportionate use of Tiotropium in AS in the GP group. CONCLUSION: AS were somewhere in between COPD patients and ANS for a large number of the characteristics studied, suggesting that they are an intermediate phenotype between COPD and asthma. [less ▲]

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See detailEx-situ’ conservation of Antarctic cyanobacteria : a culture collection to explore diversity and bioactivity
Wilmotte, Annick ULg; Renard, Marine ULg; Kleinteich, J et al

Poster (2014, August)

Cyanobacteria appear as the dominant phototrophs in Antarctic terrestrial and freshwater ecosystems. Since 2011, the Belgian Science Policy Office has funded the BCCM/ULC public collection of (sub)polar ... [more ▼]

Cyanobacteria appear as the dominant phototrophs in Antarctic terrestrial and freshwater ecosystems. Since 2011, the Belgian Science Policy Office has funded the BCCM/ULC public collection of (sub)polar cyanobacteria. It is currently holding 102 Antarctic cyanobacterial strains and the catalogue is available on http://bccm.belspo.be/db/ulc_search_form.php. A Quality Management System was implemented and an ISO9001 certificate was obtained for the public deposition and distribution of strains. The strains are kept as living cultures, and their cryopreservation is in progress. The Antarctic cyanobacterial strains were isolated from samples of the three main biogeographic provinces. The purpose of this public collection is to gather a representative portion of the cyanobacterial diversity with different ecological origins (limnetic microbial mats, soil crusts, cryoconites, endoliths, etc.) and make it available for researchers to study the diversity, evolution, adaptations to the environmental conditions, and genomic make-up. Three cyanobacterial orders are represented: Chroococcales, Oscillatoriales and Nostocales. This is particularly important in view of the emerging use of metagenomic approaches on environmental samples, where the comparisons with the genome sequences from well-defined strains is very useful. They could also serve as references for compounds such as fatty acids and pigments. In addition, cyanobacteria produce a range of secondary metabolites (e.g. alkaloides, cyclic and linear peptides, polyketides) with different bioactive potential (e.g. antibiotic, antiviral, anticancer, cytotoxic, genotoxic). Bioassays have shown antifungal activities of the cell extracts of strains Plectolyngbya hodgsonii ULC009 and Phormidium priestleyi ULC026. Due to the geographic isolation and the strong environmental stressors of the habitat, the exploration of these metabolites in Antarctic cyanobacterial strains seems especially promising for biotechnology or biomedical applications. In summary, the BCCM/ULC public collection could serve as a general reference for Antarctic cyanobacteria with multiple applications, as well as a resource for novel bioactive compounds. [less ▲]

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See detail‘Ex-situ’ preservation and characterization of Antarctic cyanobacteria in the BCCM/ULC collection
Kleinteich, Julia ULg; Renard, Marine ULg; Simons, Véronique et al

Poster (2015, June 09)

The BCCM/ULC public collection of (sub)polar cyanobacteria is funded since 2011 by the Belgian Science Policy Office. An ISO9001 certificate was obtained for the public deposition and distribution of ... [more ▼]

The BCCM/ULC public collection of (sub)polar cyanobacteria is funded since 2011 by the Belgian Science Policy Office. An ISO9001 certificate was obtained for the public deposition and distribution of strains, as part of the multi-site certification for the BCCM consortium. BCCM/ULC is currently holding 160 public cyanobacterial strains and the catalogue is available on http://bccm.belspo.be/catalogues/ulc-catalogue-search. Continuous maintenance of living cultures, some of which are also cryopreserved, ensure the preservation and the possibility to rapidly deliver strains to clients for fundamental and applied research. The main holding of the collection concerns (sub)polar strains isolated from different biotopes and representative of a large taxonomic diversity. The molecular characterization is underway, on the basis of 16S rRNA and ITS sequences, but also Multiple Locus Sequence Analysis and genome sequencing. In addition, cyanobacteria are known to produce a range of secondary metabolites (e.g. alkaloides, cyclic and linear peptides, polyketides) with various bioactive potential. The presence of genes involved in the production of microcystin is currently studied by PCR, and analytical methods are used to confirm the toxin production. Due to the geographic isolation and the strong environmental stressors of the habitat, the exploration of these metabolites in Antarctic cyanobacterial strains seems especially promising for biotechnology or biomedical applications. [less ▲]

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See detailEx-vivo cytokine production by whole blood cells from cancer patients
De Groote, Donat; Vrindts-Gevaert, Yvonne; Lopez Y Cadenas, Miguel ULg et al

in Cancer Detection & Prevention (1996), 20

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See detailLes exacerbations dans la BPCO: un fardeau a reduire
Corhay, Jean-Louis ULg; Nguyen Dang, Delphine ULg; Louis, Renaud ULg

in Revue Médicale de Liège (2006), 61(10), 691-6

Exacerbations of chronic obstructive pulmonary disease (COPD) play a very important role. Unfortunately they were neglected a long time in the therapeutic tests. However exacerbations influence the ... [more ▼]

Exacerbations of chronic obstructive pulmonary disease (COPD) play a very important role. Unfortunately they were neglected a long time in the therapeutic tests. However exacerbations influence the decline of the respiratory function over time, cause important deterioration of the quality of life of the patients, increase morbidity and mortality of COPD, and finally represent a burden for health care. Reducing the number of exacerbations could potentially slow down the progression of the disease. Thus the prevention of exacerbations should be the "corner stone" of the maintenance treatment of the COPD. In this review we propose to recall the importance of exacerbations in COPD and to present the treatment which have been shown to reduce exacerbation rate in COPD. [less ▲]

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See detailExact algorithms for the Equitable Traveling Salesman Problem
Kinable, Joris; Smeulders, Bart ULg; Delcour, Eline et al

in European Journal of Operational Research (2017)

Given a weighted graph G = (V,E), the Equitable Traveling Salesman Problem (ETSP) asks for two perfect matchings in G such that (1) the two matchings together form a Hamiltonian cycle in G and (2) the ... [more ▼]

Given a weighted graph G = (V,E), the Equitable Traveling Salesman Problem (ETSP) asks for two perfect matchings in G such that (1) the two matchings together form a Hamiltonian cycle in G and (2) the absolute difference in costs between the two matchings is minimized. The problem is shown to be NP-Hard, even when the graph G is complete. We present two integer programming models to solve the ETSP problem and compare the strength of these formulations. One model is solved through branch-and-cut, whereas the other model is solved through a branch-and-price framework. A simple local search heuristic is also implemented. We conduct computational experiments on different types of instances, often derived from the TSPLib. It turns out that the behavior of the different approaches varies with the type of instances. For small and medium sized instances, branch-and-bound and branch-and-price produce comparable results. However, for larger instances branch-and- bound outperforms branch-and-price. [less ▲]

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See detailExact and Heuristic Solution Methods for a VRP with Time Windows and Variable Service Start Time
Michelini, Stefano ULg; Arda, Yasemin ULg; Crama, Yves ULg et al

Conference (2015, February 05)

We consider a VRP with time windows in which the total cost of a solution depends on the duration of the vehicle routes, and the starting time for each vehicle is a decision variable. We first develop a ... [more ▼]

We consider a VRP with time windows in which the total cost of a solution depends on the duration of the vehicle routes, and the starting time for each vehicle is a decision variable. We first develop a Branch-and-Price algorithm considering the pricing subproblem, an elementary shortest path problem with resource constraints (ESPPRC). We discuss research on this exact solution methodology, based on a bidirectional dynamic programming approach for the ESPPRC, and on the design of a matheuristic. [less ▲]

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See detailExact and Heuristic Solution Methods for a VRP with Time Windows and Variable Service Start Time
Michelini, Stefano ULg; Arda, Yasemin ULg; Crama, Yves ULg et al

Conference (2015, June 10)

We consider a VRP with time windows in which the total cost of a solu- tion depends on the total duration of the vehicle routes, and the starting time for each vehicle is a decision variable. We first ... [more ▼]

We consider a VRP with time windows in which the total cost of a solu- tion depends on the total duration of the vehicle routes, and the starting time for each vehicle is a decision variable. We first develop a Branch- and-Price (BP) algorithm considering the related pricing subproblem, an elementary shortest path problem with resource constraints (ESP- PRC). We discuss past, present and planned research on this exact so- lution methodology, based on a bidirectional dynamic programming approach for the ESPPRC, and on the design of a matheuristic. [less ▲]

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See detailAn exact bi-directional dynamic programming algorithm for an elementary shortest path problem with variable service start time
Arda, Yasemin ULg; Crama, Yves ULg; Kucukaydin, Hande ULg

Conference (2014, January 31)

We consider an elementary shortest path problem with resource constraints (ESPPRC), where a capacitated single vehicle serves customers by respecting their associated time windows. The vehicle can start ... [more ▼]

We consider an elementary shortest path problem with resource constraints (ESPPRC), where a capacitated single vehicle serves customers by respecting their associated time windows. The vehicle can start servicing the customers at any desired time, but it can be used for a fixed amount of time. The total transportation cost depends on the total distance traveled and the total amount of time that the vehicle spends by performing the assigned trip. On the other hand, each served customer yields a revenue. Thus, the aim is to identify the path to be followed and the start time of the vehicle from the depot that minimize the total transportation cost minus the gained revenues. This kind of a problem can be encountered as a pricing subproblem when a branch-and-price algorithm is applied to solve vehicle routing problems with additional constraints. In such a case, the revenues correspond to the dual prices of the visited vertices. It is known that the classical ESPPRC can be solved to optimality by implementing a dynamic programming (DP) algorithm. However, our problem has to take an infinite number of Pareto-optimal states into consideration, since the vehicle can leave the depot at any point in time and charges depending on the total traveling and waiting time. We propose an exact DP algorithm which can deal with an infinite number of Pareto-optimal states by representing total traveling and waiting time as a piecewise linear function of the service start time at the depot and develop suitable dominance rules. Furthermore, a column generation algorithm is devised for solving the relaxed set covering formulation of the related vehicle routing problem where new columns are determined by the proposed DP algorithm. Finally, computational results are presented. [less ▲]

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See detailExact Model Reduction of Combinatorial Reaction Networks
Conzelmann, Holger; Fey, Dirk ULg; Gilles, E. D.

in BMC Systems Biology (2008), 2

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See detailExact Representation of Interfaces Using Enriched Level-Set Technique
Asadi Kalameh, Hossein ULg; Pierard, Olivier; Béchet, Eric ULg

Conference (2015, July)

This work aims to improve implicit representation of complex industrial work-pieces by reducing the existing gap between Computer Aided Design (CAD) and Computer Aided Engineering (CAE). The proposed ... [more ▼]

This work aims to improve implicit representation of complex industrial work-pieces by reducing the existing gap between Computer Aided Design (CAD) and Computer Aided Engineering (CAE). The proposed approach is based on the level-set technique [1]. Limitations of the latter technique results in the miss-capturing of corners lying on the interface (iso-0 level-set) and other sharp features. These limitations also have a significant impact on surrounding elements. In order to avoid undesired over-smoothing to the sharp features, especially corners, an enhanced representation is proposed that is based on level sets method is introduced. This technique, referred in what follows by “level-set+” ,enriches the classical level-set by using data related to the corner points. This is done by automatically detecting geometrical points and using this information in the implicit representation. Elements containing these geometrical points and surrounding elements will be re-subdivided according to the updated iso-contour. This technique helps to employ classical level set and preserve current data structure for most of the creation of the iso-0 level set. Although the method is general enough to handle most possible configurations in terms of the corner locations, there are still limitations which have been handled in such a way to prevent computational failure. Also, the technique is effective at reducing the memory requirements by automatically erasing sharp features that are no longer existing after e.g. boolean operations. Some novel results illustrates accurate implicit representations of boundaries including the exact capture of sharp features in 2D and 3D. All the developments are implemented in our in-house finite element software Morfeo. There are numerous applications which can benefit from the above mentioned developments including crack propagation with the X-FEM method and transient machining simulations. [less ▲]

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See detailAn exact Riemann Solver and Godunov Scheme for Simulating Highly Transient Mixed Flows
Kerger, François ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in Journal of Computational & Applied Mathematics (2011), 235

Detailed reference viewed: 137 (27 ULg)
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See detailExact solution of the dynamic epidemic model on the Bethe lattice
Vandewalle, Nicolas ULg; Ausloos, Marcel ULg

in Physica A: Statistical Mechanics and its Applications (1996), 230(1-2), 1-10

The dynamic epidemic model considers the spreading of a cluster in a medium containing a fraction x of mobile particles which are pushed by the propagation front. This model is analytically studied on the ... [more ▼]

The dynamic epidemic model considers the spreading of a cluster in a medium containing a fraction x of mobile particles which are pushed by the propagation front. This model is analytically studied on the Bethe lattice for any branching rate z. We give the exact solution x(c)= (z(2) - 1)/z(2) for the percolation threshold. This is in contrast with the x(c) = (z - 1)/z result for static particles. Moreover, we calculate the critical exponents y = 1 and v = 1 characterizing respectively the divergence of the cluster mass and the correlation length at x(c). These exponents are found to be the same as for the case of static particles, i.e. for random percolation on the Bethe lattice. [less ▲]

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See detailExact solution to the relative orbital motion in a central force field
Condurache, D.; Martinusi, Vladimir ULg

in 2nd International Symposium on Systems and Control in Aerospace and Astronautics, 2008. ISSCAA 2008. (2008)

The paper presents the exact solution to the relative orbital motion that takes place in a central force field.This problem is a generalization of the problem of the Keplerian relative motion in a central ... [more ▼]

The paper presents the exact solution to the relative orbital motion that takes place in a central force field.This problem is a generalization of the problem of the Keplerian relative motion in a central force field. The solution is presented in a coordinate free vectorial form, offering closed form expressions for the law of motion and the velocity. The solution is offered to the non-linear model of the relative motion problem, and itgeneralizes the solutions found by Clohessy-Wiltshire, Lawden and Tschauner-Hempel for the case of the Keplerian relative motion. The applications of this problem are in satellite formation flying, satellite constellations and orbital rendezvous. [less ▲]

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See detailExact solution to the relative orbital motion in eccentric orbits
Condurache, Daniel; Martinusi, Vladimir ULg

in Solar System Research (2009), 43

This paper studies the relative orbital motion between arbitrary Keplerian trajectories. A closed-form vectorial solution to the nonlinear initial value problem that models this type of motion with ... [more ▼]

This paper studies the relative orbital motion between arbitrary Keplerian trajectories. A closed-form vectorial solution to the nonlinear initial value problem that models this type of motion with respect to a noninertial reference frame is offered. Without imposing any particular conditions on the leader or the deputy satellites trajectories, exact expressions for the relative law of motion and relative velocity are obtained in a closed form. This solution allows the parameterization of the relative motion manifold and offers new methods to study its geometrical and topological properties. The result presented in this paper opens the way to obtain new classes of approximate solutions to the equations of relative motion with time, an eccentric or true anomaly as independent variables. [less ▲]

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See detailExact validation of breeding value prediction software
Leclerc, H.; Druet, Tom ULg; Ducrocq, V.

in Proceedings of the 8th World Congress on Genetics Applied to Livestock Production (2006)

Detailed reference viewed: 12 (0 ULg)