Showing results 141 to 160 of 2885
   Study of the oxygen budget of the Black Sea waters using a 3D coupled hydrodynamical-biogeochemical modelGrégoire, Marilaure  ; in Journal of Marine Systems (2001), 31(1-mars Sp. Iss. SI), 175-202 The ventilation of the Black Sea waters by physical and biogeochemical processes is investigated using the Geohydrodynamics and Environment Research (GHER) laboratory 3D coupled hydrodynamical ... [more ▼] The ventilation of the Black Sea waters by physical and biogeochemical processes is investigated using the Geohydrodynamics and Environment Research (GHER) laboratory 3D coupled hydrodynamical-biogeochemical model. In particular, the penetration at depth of the winter mixing, the generation of unstable motions by frontal instabilities, the exchanges between the north-western shelf and the open sea along the shelf break, the primary production distribution, the generation of detritus and the resulting consumption of oxygen for their recycling are studied. The GHER 3D hydrodynamic model is used to simulate the Black Sea's general circulation and the associated synoptic and mesoscale structures. This model is coupled with a simple ecosystem model defined by a nitrogen cycle which is described by seven state variables: nitrate, ammonium, dissolved oxygen, phytoplankton, zooplankton, pelagic and benthic detritus. The model simulates the space-time variations of the biogeochemical state variables. In particular, the spatial variability of the phytoplankton biomass annual cycle, imparted by the horizontal and vertical variations of the physical and chemical properties of the water column, is clearly illustrated. For instance, on the north-western shelf, the seasonal variability of the circulation and in particular, the reversal of the surface current at the end of spring, has a strong influence on the transport of the rich nutrient Danube waters and, thus, on the repartition of the primary production. Furthermore, the results illustrate the seasonal and vertical variations of the dissolved oxygen concentration resulting (a) from its atmospheric and photosynthetic productions in the surface layer, (b) from its loss to the atmosphere in spring and summer and (c) from its consumption associated with the detritus decomposition, the ammonium oxidation during the nitrification process, as well as the oxidation of hydrogen sulfide. The simulated sea surface, phytoplankton fields are compared with satellite estimates of chlorophyll-a fields. Comparisons are made with seasonal mean pictures and snapshot images, illustrating the mesoscale motions of the main coastal current. In the central Black Sea and the Danube delta area, comparisons with available field data are also made. As a general rule, all these comparisons show a quite good qualitative agreement. In particular, at the surface, the simulated phytoplankton space-time distribution is in a good qualitative agreement with satellite observations. However, on a quantitative point of view, the model underestimates the bloom intensity especially in the Danube discharge area. (C) 2001 Elsevier Science B.V. All rights reserved. [less ▲] Detailed reference viewed: 24 (4 ULg)The control of preoptic aromatase activity by afferent inputs in Japanese quailAbsil, Philippe ; ; et alin Brain Research Reviews (2001), 37(1-mars Sp. Iss. SI), 38-58 This review summarizes current knowledge on the mechanisms that control aromatase activity in the quail preoptic area, a brain region that plays a key role in the control of reproduction. Aromatase and ... [more ▼] This review summarizes current knowledge on the mechanisms that control aromatase activity in the quail preoptic area, a brain region that plays a key role in the control of reproduction. Aromatase and aromatase mRNA synthesis in the preoptic area are enhanced by testosterone and its metabolite estradiol, but estradiol receptors of the alpha subtype are not regularly colocalized with aromatase. Estradiol receptors of the beta subtype are present in the preoptic area but it is not yet known whether these receptors are colocalized with aromatase. The regulation by estrogen of aromatase activity may be, in part, trans-synaptically mediated, in a manner that is reminiscent of the ways in which steroids control the activity of gonadotropic hormone releasing hormone neurons, Aromatase-immunoreactive neurons are surrounded by dense networks of vasotocin-immunoreactive and tyrosine hydroxylase-immunoreactive fibers and punctate structures. These inputs are in part steroid-sensitive and could therefore mediate the effects of steroids on aromatase activity. In vivo pharmacological experiments indicate that catecholaminergic depletions significantly affect aromatase activity presumably by modulating aromatase transcription. In addition, in vitro studies on brain homogenates or on preoptic-hypothalamic explants show that aromatase activity can be rapidly modulated by a variety of dopaminergic compounds. These effects do not appear to be mediated by the membrane dopamine receptors and could involve changes in the phosphorylation state of the enzyme, Together, these results provide converging evidence for a direct control of aromatase activity by catecholamines consistent with the anatomical data indicating the presence of a catecholaminergic innervation of aromatase cells. These dopamine-induced changes in aromatase activity are observed after several hours or days and presumably result from changes in aromatase transcription but rapid non-genomic controls have also been identified. The potential significance of these processes for the physiology of reproduction is critically evaluated. (C) 2001 Elsevier Science BY. All rights reserved. [less ▲] Detailed reference viewed: 15 (0 ULg)Comparison of the skull development in Damselfish (Pomacentridae): an ecomorphological approachFrederich, Bruno ; Parmentier, Eric ; Vandewalle, Pierre Poster (2001, November) Detailed reference viewed: 12 (1 ULg)Obituary : R.H. HARRIS ( Soul Stirrers, ....)Sacré, Robert in Soul Bag (2001), (161), 33 Rebert H. HARRIS 1916- 2000 - chanteur lead des Soul Stirrers Detailed reference viewed: 11 (0 ULg) Least-Cost Structural Optimization Oriented Preliminary DesignRigo, Philippe in Journal of Ship Production (2001) Detailed reference viewed: 60 (1 ULg)A Module-Oriented Tool for Optimum Design of Stiffened StructuresRigo, Philippe in Marine Structures (2001) Detailed reference viewed: 39 (1 ULg)The expanding role of Octreotide (Introductory lecture : Diagnosis course of disease and remission criteria)Beckers, Albert Scientific conference (2001, November) Detailed reference viewed: 2 (0 ULg)Cytological and ecological complexity in the Early Mesoproterozoic.Javaux, Emmanuelle ; ; Conference (2001, November) Detailed reference viewed: 2 (0 ULg)Diagnostisch beleid bij verhoogde transaminasenspiegelsDelwaide, Jean ; ; Detry, Olivier et alin Patient Care (Nederlandse Editie) (2001), 28(11), 33-41 Detailed reference viewed: 3 (0 ULg)La guerre et la medecine d'une culture de paix. 1. Quand s'ouvrent les portes du temple de janusPierard, Gérald in Revue Médicale de Liège (2001), 56(11), 785-7 More than 40 major wars took place during the past decade. The origins and the warlike means that were engaged were very different from those of older conflicts. Wars between nations are less numerous ... [more ▼] More than 40 major wars took place during the past decade. The origins and the warlike means that were engaged were very different from those of older conflicts. Wars between nations are less numerous. They have been replaced by civilian wars that are more rooted on cultural and religious grounds than on economic interests alone. During this short period of time, warfare was responsible for about 2 millions of direct deaths and 20 millions displaced people and refugees. The injured and victims of starvation and epidemics were innumerable and awaited for civilian medical help. [less ▲] Detailed reference viewed: 13 (2 ULg)L'image du mois. Un melanome masque chez un joueur de tennis; Henry, Frédérique ; Pierard-Franchimont, Claudine et alin Revue Médicale de Liège (2001), 56(11), 737-8 A man presented with a malignant melanoma of the scalp. The lesion reached a large size before being disclosed. Repetitive sunburns during tennis matches could be responsible for this cancer. Indeed, hair ... [more ▼] A man presented with a malignant melanoma of the scalp. The lesion reached a large size before being disclosed. Repetitive sunburns during tennis matches could be responsible for this cancer. Indeed, hair protects only partially the skin from ultraviolet damages. [less ▲] Detailed reference viewed: 7 (1 ULg), Simulation de l'injection de résine sur renforts fibreuxBéchet, Eric Scientific conference (2001, November) Detailed reference viewed: 5 (0 ULg)Normal ranges for the variability in heart rate in young infants while sleeping; Withofs, Nadia ; et alin Cardiology in the Young (2001), 11(6), 619-625 Objective: Measurements of the variability in heart rate are increasingly used as markers of cardiac autonomic activity. We sought to establish the development this variability in healthy young infants ... [more ▼] Objective: Measurements of the variability in heart rate are increasingly used as markers of cardiac autonomic activity. We sought to establish the development this variability in healthy young infants while sleeping. Patients: We carried out polygraphic studies with electrocardiographic recording in 587 healthy infants aged from 5 to 26 weeks. Methods: We determined several variables over a period of 400 minutes sleeping: mean RR interval, 5 time-domain (SDNN, SDNNi, SDANNi, RMSSD, and pNN50) and 5 frequency-domain indexes (spectral power over 3 regions of interest, total power and low-to-high frequency ratio). Frequency-domain indexes were also assessed separately for the periods of quiet sleep and those of rapid eye movement sleep. Results: Our data showed a significant correlation between the indexes of heart rate variability and the mean RR interval, the breathing rate, and the corrected age of the infants. We also demonstrated the importance of the maturation of the sleeping patterns. Conclusion: These data in a large cohort of healthy infants confirm a progressive maturation of the autonomic nervous system during sleep, and may be used to examine the influence of physiological and pathophysiological factors on autonomic control during polygraphic studies. [less ▲] Detailed reference viewed: 6 (0 ULg)Labyrinthine Granular LandscapesCaps, Hervé ; Vandewalle, Nicolas in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2001), 64(5, Pt 1), 52301 We have numerically studied a model of granular landscape eroded by wind. We show the appearance of labyrinthic patterns when the wind orientation turns by 90 degrees. The occurrence of such structures is ... [more ▼] We have numerically studied a model of granular landscape eroded by wind. We show the appearance of labyrinthic patterns when the wind orientation turns by 90 degrees. The occurrence of such structures is discussed. Moreover, we introduce the density n(k) of "defects" as the dynamic parameter governing the landscape evolution. A power-law behavior of n(k) is found as a function of time. In the case of wind variations, the exponent (drastically) shifts from two to one. The presence of two asymptotic values of n(k) implies the irreversibility of the labyrinthic formation process. [less ▲] Detailed reference viewed: 6 (2 ULg)Relationship between maternal concentrations of caprine pregnancy-associated glycoprotein in Alpine goats and the number of fetuses using a homologous radioimmunoassay; Sulon, Joseph ; et alin Small Ruminant Research (2001), 42(2), 105-109 The relationship between maternal caprine pregnancy-associated glycoprotein (cPAG) concentrations and fetal number was investigated in 21 nulliparous and 17 multiparous goats. Using a homologous ... [more ▼] The relationship between maternal caprine pregnancy-associated glycoprotein (cPAG) concentrations and fetal number was investigated in 21 nulliparous and 17 multiparous goats. Using a homologous radioimmunoassay (hm-RIA) cPAG was detected in plasma of pregnant goats from the 21st day of pregnancy. Statistical differences between goats bearing single and multiple fetuses were observed after 63 days to the end of pregnancy, except on day 133. After 126 days (3rd week pre-partum) cPAG levels began to decrease slowly in both the groups. The hm-RIA was an efficient method to describe the relationship between maternal PAO concentrations and number of fetuses in goats. (C) 2001 Published by Elsevier Science B.V. [less ▲] Detailed reference viewed: 11 (1 ULg)Plasma profile of pregnancy associated glycoprotein (PAG) in pregnant Alpine goats using two radioimmunoassay (RIA) systems; Sulon, Joseph ; et alin Small Ruminant Research (2001), 42(2), 111-118 This paper evaluates the profiles obtained for caprine pregnancy associated glycoprotein (cPAG) in pregnant multiparous and nulliparous goats using the heterologous-radioimmunoassay (htPAG-RIA) and the ... [more ▼] This paper evaluates the profiles obtained for caprine pregnancy associated glycoprotein (cPAG) in pregnant multiparous and nulliparous goats using the heterologous-radioimmunoassay (htPAG-RIA) and the homologous-RIA (hmPAG-RIA) systems during the pregnancy and postpartum periods. The results show that the cPAG concentrations detected through the hmPAG-RIA procedure were lower than those found through the htPAG-RIA method. No statistical differences were observed due to the maternal reproductive status (nulliparous or multiparous goats) during pregnancy using either one of the methods. However, pregnant and cyclic goats were distinguished from each other by cPAG concentrations verified through the hmPAG-RIA procedure. The lower cPAG concentrations detected through this method suggest that this system is more specific than the htPAG-RIA procedure to measure cPAG during pregnancy and postpartum period in goats. The homologous system was also an efficient method to predict pregnancies of only 35 days in both nulliparous and multiparous goats. (C) 2001 Published by Elsevier Science B.V. [less ▲] Detailed reference viewed: 25 (2 ULg)Presentation anatomo-clinique. Terato-carcinome testiculaire avec adenopathies thoraco-abdominales; ; et al in Revue Médicale de Liège (2001), 56(11), 777-84 This case report of a young man with a testicular germ cell-teratoma tumor illustrates the necessity of a multidisciplinary sequential approach to ensure chance of cure. The outcome of patients with ... [more ▼] This case report of a young man with a testicular germ cell-teratoma tumor illustrates the necessity of a multidisciplinary sequential approach to ensure chance of cure. The outcome of patients with advanced germ cell tumor depends on the optimal clinical management. Residual masses are frequent, and their histology can be different than the initial one (i.e., only residual mature teratoma cells or necrosis-fibrosis). Therefore a second surgery on residual masses with curative intent, may be important to optimalize the treatment and follow up. [less ▲] Detailed reference viewed: 12 (5 ULg)Modélisation mathématique de simulation des crues de la Chiers amont à l’aide des modèles MHM et MOHICANBourouag, Mohamed ; ; Everbecq, Etienne et alReport (2001) En 1999, l’Association Intercommunale pour la Valorisation de l’Eau (AIVE) a confié à l’Université de Liège (Laboratoire de Géologie de l’Ingénieur, d’Hydrogéologie et de Prospection géophysique (LGIH-ULG ... [more ▼] En 1999, l’Association Intercommunale pour la Valorisation de l’Eau (AIVE) a confié à l’Université de Liège (Laboratoire de Géologie de l’Ingénieur, d’Hydrogéologie et de Prospection géophysique (LGIH-ULG), Laboratoire d’Hydrodynamique appliquée (HYD-ULG), Centre d’Etude et de Modélisation de l’Environnement (CEME-ULG)), à la Faculté Universitaire des Sciences Agronomiques de Gembloux (Unité d’Hydraulique Agricole) et à l’Université Catholique de Louvain (Unité de Génie rural (GERU-UCL)), la mission de réaliser des modélisations mathématiques de simulations des crues de la CHIERS amont à l’aide des modèles MHM et MOHICAN. Le modèle MHM (« Modèle Hydrologique Maillé ») a été développé par l’Unité de Génie rural de l’UCL. Le modèle MOHICAN (« Modèle hydrologique intégré pour le calcul des crues et l’amplitude des niveaux d’eau ») a été développé conjointement par l’Université de Liège (Laboratoire d’hydrodynamique appliquée, Laboratoire de Géologie de l’Ingénieur et d’Hydrogéologie, Centre d’Etude et de Modélisation de l’environnement) et la Faculté Universitaire des Sciences Agronomiques de Gembloux Louvain (Unité d’Hydraulique agricole) pour le compte et avec le support du Ministère de l’Equipement et des Transports, Service d’Etudes Hydrologiques (MET/SETHY) de la Région wallonne. Le MET a donné l’autorisation d’utiliser le modèle MOHICAN dans le cadre de l’étude hydrologique de la CHIERS. L’étude est organisée en 3 étapes : (i) Elaboration des bases de données et exécution des modèles, (ii) Réalisation de tests des modèles et calibration et (iii) Simulation de scénarios. Le présent rapport présente d’abord le modèle MHM (chapitre 2) et le modèle MOHICAN (chapitre 3) ainsi que les bases de données nécessaires à leur utilisation (chapitre 4 : bases de données pour MHM, chapitre 5 : bases de données pour MOHICAN). Les premières étapes de simulation (phase de calibration et de validation) sont présentées au chapitre 6 (Modélisation MHM – Calibration/Validation) et au chapitre 7 (Modélisation MOHICAN – Calibration/Validation). Enfin, les simulations ont été réalisées : - pour le bassin de la Messancy à Athus, d’une superficie de 68 km² environ; - pour le bassin de la Chiers à Longlaville, représentant un bassin versant de 157 km² environ (comprenant le bassin de la Messancy). Ces simulations réalisées sur base de différents scénarios d’aménagement du bassin de la Chiers amont sont présentées au chapitre 8 (Modélisation MHM – Scénarios) et au chapitre 9 (Modélisation MOHICAN – Scénarios). [less ▲] Detailed reference viewed: 24 (4 ULg) Goethe und Lessing - Anatomie einer "Vergegegnung" (Rezension zu: Wilfried Barner: Goethe und Lessing : Eine schwierige Konstellation)Viehöver, Vera in IASL Online (2001) Detailed reference viewed: 15 (4 ULg)Les coûts de la désurbanisationHalleux, Jean-Marie Conference given outside the academic context (2001) Detailed reference viewed: 4 (1 ULg) |
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