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See detailSurentrainement et efforts d'endurance
Jidovtseff, Boris ULg; Crielaard, Jean-Michel ULg

in Revue Médicale de Liège (2001), 56(5), 343-52

Optimal training results in exercise-recovery harmonious balance. High frequency and volumic training, associated with insufficient recovery may induce overtraining. It depends on the kind of exercise but ... [more ▼]

Optimal training results in exercise-recovery harmonious balance. High frequency and volumic training, associated with insufficient recovery may induce overtraining. It depends on the kind of exercise but occurs mainly in endurance sports. The high frequency of upper respiratory track infection in endurance sportsmen results from a temporary immunosuppression state, possibly associated with overtraining. Many immune and haematological parameters have been associated with overtraining, but none seemed really efficient for diagnosis. Hormonal parameters, despite contradictions in studies, appear to give a good insight of athlete's staleness and are more predictive of overtraining. Actually, overtraining detection needs a combination of different parameters, and cannot sustain on isolated factors. [less ▲]

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See detailArchaeopteris from the Upper Famennian of Belgium: Heterospory, Nomenclature, and Palaeobiogeography
Fairon-Demaret, Muriel ULg; Leponce, Isabelle ULg; Streel, Maurice ULg

in Review of Palaeobotany & Palynology (2001), 115(1-2), 79-97

New fertile specimens of Archaeopteris roemeriana from Upper (but not uppermost) Famennian strata of Belgium have been studied. Crowded sporangia are borne on non-laminate, three times bifurcate fertile ... [more ▼]

New fertile specimens of Archaeopteris roemeriana from Upper (but not uppermost) Famennian strata of Belgium have been studied. Crowded sporangia are borne on non-laminate, three times bifurcate fertile leaves helically arranged around the fertile ultimate axes. Vegetative leaves occur both proximal and distal to the fertile leaves. Heterospory is demonstrated with miospores belonging to the Geminospora-Aneurospora complex and macrospores most probably to Contagisporites genus. The established morphological traits allow us to substantiate a synonymy between A. roemeriana and A. halliana. The apparent dominance of A. halliana on the eastern side of the Acadian mountains during Late Famennian times is discussed. [less ▲]

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See detailLes possibilités d’utilisation du matériel GPS en forêt
Lejeune, Philippe ULg

Learning material (2001)

Introduction Le matériel GPS a fait une percée très remarquée dans de nombreuses applications civiles au cours des cinq dernières années (transports, génie civil, topographie, randonnée, …). La gestion ... [more ▼]

Introduction Le matériel GPS a fait une percée très remarquée dans de nombreuses applications civiles au cours des cinq dernières années (transports, génie civil, topographie, randonnée, …). La gestion forestière, pour laquelle la dimension spatiale joue un rôle important, n’échappe pas à la règle et les possibilités d’application de cette nouvelle technologie y sont multiples. Le présent document a pour objectif d'expliquer les grands principes de fonctionnement des récepteurs GPS et de présenter les possibilités d'utilisation de ces appareils en forêt. L’accent est mis sur les niveaux de précision à espérer en fonction des conditions d’utilisation. Le type d’appareil considéré dans ce document est celui des récepteurs de bas de gamme (GPS dits de "randonnée"), dont le prix d'achat varie entre 250 et 500 €. Ce choix délibéré est lié non seulement au coût abordable de cette gamme d’appareils, mais également à sa simplicité de mise en oeuvre. [less ▲]

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See detailIsocinétisme et traumatologie sportive
Croisier, Jean-Louis ULg; Crielaard, Jean-Michel ULg

in Revue Médicale de Liège (2001), 56(5), 360-8

The assessment of human muscle strength is of considerable value in various pathological states with modifications of the performance level. The original concept of isokinetic dynamometry provides a ... [more ▼]

The assessment of human muscle strength is of considerable value in various pathological states with modifications of the performance level. The original concept of isokinetic dynamometry provides a precise and reliable quantification of strength. Identification of underlying deficits in bilateral and reciprocal muscle group relationships plays a great role in the treatment of anterior cruciate ligament (ACL) reconstruction and muscle injuries. The value of this type of assessment for prevention in uninjured subjects practicing sports at risk is suggested. Rehabilitative use of isokinetic includes muscle strengthening and tendinitis treatment by means of eccentric exercises. [less ▲]

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See detailSeismic behaviour and design of composite steel concrete structures
Plumier, André ULg; Doneux, Catherine

Report (2001)

The report presents research activities on the seismic behaviour of composite steel concrete moment frames co-ordinated in Europe within the ICONS project. Research has been focused on problems of ... [more ▼]

The report presents research activities on the seismic behaviour of composite steel concrete moment frames co-ordinated in Europe within the ICONS project. Research has been focused on problems of ductility and resistance in the case where the connections of the steel parts are full strength "rigid". Tests have been realised on subassemblages, on elements, on a plane frame and on a 3-D frame. Some tests were run quasi statically, others on shaking tables. Numerical modelling was done in parallel. Summary reports of these activities are presented. Based on that research and on literature data, for the structural types and elements other than those of typical European composite moment frames, design rules have been developed. These rules, which are now under implementation within the 2001 EN version of Eurocode 8 are presented with comments and reference to background. [less ▲]

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See detailElectromyostimulation en medecine du sport
Vanderthommen, Marc ULg; Crielaard, Jean-Michel ULg

in Revue Médicale de Liège (2001), 56(5), 391-5

Neuromuscular electrical stimulation (NMES) is frequently used to strengthen the normal muscle. In medicine, several investigators have highlighted the value of NMES when treating amyotrophy related to ... [more ▼]

Neuromuscular electrical stimulation (NMES) is frequently used to strengthen the normal muscle. In medicine, several investigators have highlighted the value of NMES when treating amyotrophy related to immobilization. The efficacy of NMES of the quadriceps during rehabilitation following anterior cruciate ligament surgery has been well documented. These electrical stimulation programs are composed of stimulation--rest cycles and are performed with the aid of percutaneous electrodes situated in regard to muscle motor points. The stimulation frequency is chosen to induce tetanic contractions and is generally situated between 50 and 100 Hz. During NMES, the trainer or the physiotherapist can accurately modulate a large number of parameters but the sensory discomfort linked to the current intensity remains the major limitation for strength improvement. In the context of rehabilitation, the association of NMES with voluntary exercises is superior to the isolated utilization of the classic program composed of isometric voluntary contractions. To explain this advantage of associating NMES with voluntary contractions, it has been hypothesized that the electrically induced contractions impose specific patterns of muscle recruitment and a particular metabolic solicitation. [less ▲]

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See detailSport et hypertension artérielle
Krzesinski, Jean-Marie ULg; Ancion, G.

in Revue Médicale de Liège (2001), 56(5), 306-312

Regular physical exercise belongs to the non pharmacological tools for the control of high blood pressure. When practising it almost daily at low intensity during 30 minutes, and mainly on a dynamic mode ... [more ▼]

Regular physical exercise belongs to the non pharmacological tools for the control of high blood pressure. When practising it almost daily at low intensity during 30 minutes, and mainly on a dynamic mode, blood pressure can decrease almost of the same order of magnitude as with an antihypertensive drug. In severe hypertension, blood pressure must be first controlled by drugs before starting the physical exercise training. An exercise test is preferable before exercise suggestion in sedentary people older than 40 years. In hypertensive people who enter sportive competition, diuretics and betablockers are forbidden. These agents can also reduce performance. [less ▲]

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See detailPoly(D,L-lactide) foams modified by poly(ethylene oxide)-block-poly(D,L-lactide) copolymers and a-FGF: in vitro and in vivo evaluation for spinal cord regeneration
Maquet, Véronique; Martin, Didier ULg; Scholtes, Félix ULg et al

in Biomaterials (2001), 22(10), 1137-1146

The first goal of this study was to examine the influence that poly(ethylene oxide)-block-poly(D,L-lactide) (PELA) copolymer can have on the wettability, the in vitro controlled delivery capability, and ... [more ▼]

The first goal of this study was to examine the influence that poly(ethylene oxide)-block-poly(D,L-lactide) (PELA) copolymer can have on the wettability, the in vitro controlled delivery capability, and the degradation of poly(D,L-lactide) (PDLLA) foams. These foams were prepared by freeze-drying and contain micropores (10 μm) in addition of macropores (100 μm) organized longitudinally. Weight loss, water absorption, changes in molecular weight, polymolecularity (Mw/Mn) and glass transition temperature ( Tg) of PDLLA foams mixed with various amounts of PELA were followed with time. It was found that 10 wt% of PELA increased the wettability and the degradation rate of the polymer foams. The release of sulforhodamine (SR) was compared for PDLLA and PDLLA-PELA foams in relation with the foam porosity. An initial burst release was observed only in the case of the 90:10 PDLLA/PELA foam. The ability of the foam of this composition to be integrated and to promote tissue repair and axonal regeneration in the transected rat spinal cord was investigated. After implantation of ca. 20 polymer rods assembled with fibrin-glue, the polymer construct was able to bridge the cord stumps by forming a permissive support for cellular migration, angiogenesis and axonal regrowth. [less ▲]

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See detailConsistance du lissage des contraintes par convolution
Debongnie, Jean-François ULg

Report (2001)

A systematic stress smoothing procedure is proposed on the basis of a convolution process. It is then found that in order to be effective, use has to be made of kernels satisfying to a consistency ... [more ▼]

A systematic stress smoothing procedure is proposed on the basis of a convolution process. It is then found that in order to be effective, use has to be made of kernels satisfying to a consistency condition, that is, the true stress has not to be changed by the convolution process. A family of consistent kernels is then obtained for biharmonic stresses through a step whose inspiration comes from a book of Parton and Perline. Examples are given. [less ▲]

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See detailWind turbines turbulence effects on cable structures in their vicinity
Lilien, Jean-Louis ULg; keutgen, Renaud; raimarckers, Nicolas

in Proceedings of the ISCD 2001 (2001, May)

Actual wind turbines size can be as large as 80 meters diameter (1 MW and over). Behind the wind turbines, mean wind speed is sensibly reduced (approximately 50%) and turbulence severely increased. The ... [more ▼]

Actual wind turbines size can be as large as 80 meters diameter (1 MW and over). Behind the wind turbines, mean wind speed is sensibly reduced (approximately 50%) and turbulence severely increased. The spectral density power of disturbed wind can be assumed similar to classical wind but centred on the rotational speed of the motor. Due to classical speed and shape of wind turbine, corresponding key frequency for disturbed wind is close to one Hz. Any structure in the vicinity of wind turbine can be disturbed by the new wind spectrum created by the turbine, thus existing most of the time for wind speed up to 25 m/s. Cable structure, f.e. overhead lines, have clearly 1 Hz in their first modal shapes. This make them very sensible to buffeting due to the disturbed wind induced by the turbine. Due to continuous excitation, most of the year, fatigue may occur near clamping point and extra damping may be required as well as minimum distance from the wind turbine may be recommended. The anchoring tower (whose first eigenfrequency is generally close to 1 Hz for high voltage lines) will also be affected. This paper will present some simulations of overhead lines disturbances induced by wind turbine in their vicinity. The power spectral density of wind behind the turbine will be deduced from classical spectra of Davenport, but with adaptation due to the rotation of the turbine. Effects on cable will be shown and tentative recommendations of damping as well as clearances from the turbine will be suggested. [less ▲]

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See detailDown-Regulation of Vascular Endothelial Growth Factor by Tissue Inhibitor of Metalloproteinase-2: Effect on in Vivo Mammary Tumor Growth and Angiogenesis
Hajitou, Amin; Sounni, Nor Eddine ULg; Devy, Laetitia et al

in Cancer Research (2001), 61(8), 3450-7

The tissue inhibitor of metalloproteinases-2 (TIMP-2) has at least two independent functions, i.e., regulation of matrix metalloproteinases and growth promoting activity. We investigated the effects of ... [more ▼]

The tissue inhibitor of metalloproteinases-2 (TIMP-2) has at least two independent functions, i.e., regulation of matrix metalloproteinases and growth promoting activity. We investigated the effects of TIMP-2 overexpression, induced by retroviral mediated gene transfer, on the in vivo development of mammary tumors in syngeneic mice inoculated with EF43.fgf-4 cells. The EF43.fgf-4 cells established by stably infecting the normal mouse mammary EF43 cells with a retroviral expression vector for the fgf-4 oncogene, are highly tumorigenic and overproduce vascular endothelial growth factor (VEGF). Despite a promotion of the in vitro growth rate of EF43.fgf-4 cells overexpressing timp-2, the in vivo tumor growth was delayed. At day 17 post-cell injection, the volume of tumor derived from TIMP-2-overexpressing cells was reduced by 80% as compared with that obtained with control cells. Overexpression of TIMP-2 was associated with a down-regulation of VEGF expression in vitro and in vivo, a reduction of vessel size, density, and blood supply in the induced tumors. In addition, TIMP-2 completely inhibited the angiogenic activity of EF43.fgf-4 cell-conditioned medium in vitro using a rat aortic ring model. Our findings suggest that overexpression of TIMP-2 delays growth and angiogenesis of mammary carcinoma in vivo and that down-regulation of VEGF expression may play an important role in this TIMP-2-mediated antitumoral and antiangiogenic effects. Finally the in vivo delivery of TIMP-2, as assessed by i.v. injection of recombinant adenoviruses vectors, significantly reduced the growth of the EF43.fgf-4-induced tumors. This effect of TIMP-2 was shown to be equally comparable with that of angiostatin, a known potent inhibitor of angiogenesis. [less ▲]

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See detailRadiothérapie vasculaire : un nouveau standard
Coucke, Philippe ULg; Hu Phuoc, Do; Urban, Ph. et al

in Médecine et Hygiène (2001), (3000),

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See detailLessons from the past for a better future: Ethnoecology, a promising link between tradition and science regarding biodiversity management
Malaisse, François ULg

Conference (2001, April 06)

After reviewing biological diversity data concerning tropical countries, main biodiversity issues and challenges are listed. The evolution of the “ethnoecology” concept and its present meaning are ... [more ▼]

After reviewing biological diversity data concerning tropical countries, main biodiversity issues and challenges are listed. The evolution of the “ethnoecology” concept and its present meaning are examined. Starting from two or four roots, including ethnoagronomy, ethnoecology is taking progressively a dominant position regarding local knowledge as well as in modern ecosystems’ management. The various levels of environmental knowledge are pinpointed from examples taken in Tibet, pre-Saharan Morocco, Guinea-Bisseau, Upper Katanga and Zambia, and finally Bolivia. Lessons from the past are highlighted through present ecological studies and interaction outputs are stressed and discussed. Finally, a success story of validation of non-woody forest product is presented, with the establishment of a business subject regarding wild edible mushrooms from the wetter miombo area of South Central Africa. [less ▲]

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See detailCombination of Electrografting and Ring-Opening Metathesis Polymerization: An Efficient Way to Prepare Polynorbornene Brushes on Conducting Substrates
Detrembleur, Christophe ULg; Jérôme, Christine ULg; Claes, Michaël et al

in Angewandte Chemie (International ed. in English) (2001), 40(7), 1268-1271

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See detailPsychological Evolution and Assessment in Patients Undergoing Orthotopic Heart Transplantation
Triffaux, Jean-Marc ULg; Wauthy, Jacques ULg; Bertrand, Jean-Marie ULg et al

in European Psychiatry (2001), 16(3), 180-5

BACKGROUND: Orthotopic heart transplantation (OHT) is a major surgical intervention inducing distress and anxiety. Psychiatric evaluation of organ transplant candidates is now routinely proposed. This ... [more ▼]

BACKGROUND: Orthotopic heart transplantation (OHT) is a major surgical intervention inducing distress and anxiety. Psychiatric evaluation of organ transplant candidates is now routinely proposed. This study purposed to assess the psychological evolution in patients having received psychological and/or psychiatric assistance before and during 1-6 postoperative months. METHODS: Twenty-two consecutive transplant candidates were psychically evaluated as part of the preoperative protocol. In the waiting period, 1 and 6 months after OHT, they were asked to fill out the following questionnaires: the General Health Questionnaire, the Spielberger's State-Trait Anxiety Inventory, the Beck Depression Inventory, the Perceived Social Support Scale, the Toronto Alexithymia Scale and the Personal Reaction Inventory. RESULTS: A DSM-IV Axis I diagnosis was found in nine patients (41%); four patients (18%) presented with an Axis II diagnosis. One month after OHT, scores of depression, anxiety and general health significantly improved, while scores of social support, alexithymia and social desirability did not differ. In the sixth postoperative month, all psychological scores remained stable. CONCLUSIONS: A high prevalence of preoperative psychopathology was reported in 22 candidates who received OHT. Surgical intervention obviously improved the quality of life after cardiac transplantation. If the impact of psychological and/or psychiatric aid remains difficult to appraise, these results emphasize the positive impact of surgery on psychological status and the appropriateness of the psychosomatician's social support intervention on patients facing the transplant process. [less ▲]

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See detailRobust global state feedback stabilization of cement mills
Grognard, F.; Jadot, F.; Magni, L. et al

in IEEE Transactions on Automatic Control (2001), 46(4), 618-623

Plugging is well known to be a major cause of instability in industrial cement mills. A simple nonlinear model able to simulate the plugging phenomenon is presented. It is shown how a nonlinear robust ... [more ▼]

Plugging is well known to be a major cause of instability in industrial cement mills. A simple nonlinear model able to simulate the plugging phenomenon is presented. It is shown how a nonlinear robust controller can be designed in order to fully prevent the mill from plugging [less ▲]

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See detailMicellization of quaternized poly(2-(dimethylamino)ethyl methacrylate)-block-poly(methyl methacrylate) copolymers in water
Antoun, Sayed; Gohy, Jean-François; Jérôme, Robert ULg

in Polymer (2001), 42(8), 3641-3648

Micellization of a series of amphiphilic quaternized poly(2-(dimethylamino)ethyl methacrylate)-block-poly(methyl methacrylate) (PQDMAEMA-b-PMMA) copolymers has been studied in water. The alkyl halide used ... [more ▼]

Micellization of a series of amphiphilic quaternized poly(2-(dimethylamino)ethyl methacrylate)-block-poly(methyl methacrylate) (PQDMAEMA-b-PMMA) copolymers has been studied in water. The alkyl halide used for the quaternization of the aminated block has an effect on the solution properties of the diblocks, that have been investigated by dynamic light scattering and surface tension measurements. When a short length alkyl halide is used, the diblock copolymers behave like traditional amphiphiles, whereas their behavior is similar to polysoaps in case of long alkyl halides. The size of the micelles increases when 1-bromopropan-3-ol is substituted for 1-bromopropane in the quaternization reaction. It is, however, independent of the structure of butyl bromide, i.e. n-butyl vs tert-butyl bromide. The solution properties of a star-shaped PQDMAEMA-b-PMMA copolymer have also been studied and compared to the linear counterpart. The star-shaped architecture actually prevents the block copolymer to be properly oriented at the air/water interface in agreement with the formation of unimer micelles. [less ▲]

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See detailCold-Adapted Beta-Galactosidase from the Antarctic Psychrophile Pseudoalteromonas Haloplanktis
Hoyoux, A.; Jennes, I.; Dubois, P. et al

in Applied and Environmental Microbiology (2001), 67(4), 1529-35

The beta-galactosidase from the Antarctic gram-negative bacterium Pseudoalteromonas haloplanktis TAE 79 was purified to homogeneity. The nucleotide sequence and the NH(2)-terminal amino acid sequence of ... [more ▼]

The beta-galactosidase from the Antarctic gram-negative bacterium Pseudoalteromonas haloplanktis TAE 79 was purified to homogeneity. The nucleotide sequence and the NH(2)-terminal amino acid sequence of the purified enzyme indicate that the beta-galactosidase subunit is composed of 1,038 amino acids with a calculated M(r) of 118,068. This beta-galactosidase shares structural properties with Escherichia coli beta-galactosidase (comparable subunit mass, 51% amino sequence identity, conservation of amino acid residues involved in catalysis, similar optimal pH value, and requirement for divalent metal ions) but is characterized by a higher catalytic efficiency on synthetic and natural substrates and by a shift of apparent optimum activity toward low temperatures and lower thermal stability. The enzyme also differs by a higher pI (7.8) and by specific thermodynamic activation parameters. P. haloplanktis beta-galactosidase was expressed in E. coli, and the recombinant enzyme displays properties identical to those of the wild-type enzyme. Heat-induced unfolding monitored by intrinsic fluorescence spectroscopy showed lower melting point values for both P. haloplanktis wild-type and recombinant beta-galactosidase compared to the mesophilic enzyme. Assays of lactose hydrolysis in milk demonstrate that P. haloplanktis beta-galactosidase can outperform the current commercial beta-galactosidase from Kluyveromyces marxianus var. lactis, suggesting that the cold-adapted beta-galactosidase could be used to hydrolyze lactose in dairy products processed in refrigerated plants. [less ▲]

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See detailOn Comparison Meaningfulness of Aggregation Functions
Marichal, Jean-Luc; Mathonet, Pierre ULg

in Journal of Mathematical Psychology (2001), 45(2), 213-223

This paper will give a description of all continuous functions which are comparison meaningful in the sense of measurement theory.

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