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See detailEtude comparée de la radioécologie des eaux continentales des bassins mosan et rhodanien : Modélisation du transfert de Cobalt-60 entre l’eau et l’algue Scenedesmus
Smitz, Joseph ULg; Everbecq, Etienne ULg

Report (1988)

Entre 1985 et 1990, une étude comparée de la radioécologie des écosystèmes fluviaux de la Meuse et du Rhône a été réalisée par différents laboratoires français et belges. Cette étude, appuyée par les ... [more ▼]

Entre 1985 et 1990, une étude comparée de la radioécologie des écosystèmes fluviaux de la Meuse et du Rhône a été réalisée par différents laboratoires français et belges. Cette étude, appuyée par les Communautés européennes et Electrabel comportait des études in situ, des études expérimentales et de la modélisation mathématique. La modélisation mathématique de l’écosystème fluvial a été confiée au Centre Environnement de l’ULg dans le but de développer un modèle général du transfert des radionucléides en écosystème fluvial. Ce rapport présente les tâches de modélisation mathématique réalisées en 1988, soit la réalisation d’un modèle de transfert du Cobalt-60 entre l’eau et une algue phytoplanctonique (Scenedesmus Obliquus), sur base de données expérimentales obtenues au laboratoire de Radioécologie des Eaux Continentales de Cadarache. Le modèle comprend 4 compartiments : - L’eau - La biomasse algale - Les radioéléments dans l’eau - Les radioéléments sur et dans les algues (adsorption et désorption) [less ▲]

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See detailEtude comparée de paramètres écosystémiques dans des peuplements soumis à un amendement : modélisation des flux
Everbecq, Etienne ULg; Bourouag, Mohamed ULg

Report (1994)

La modélisation du fonctionnement d’un écosystème forestier représentatif du Massif de la Haute Ardenne belge (bassin de la Robinette) a été développée, avec comme but final de mieux comprendre le ... [more ▼]

La modélisation du fonctionnement d’un écosystème forestier représentatif du Massif de la Haute Ardenne belge (bassin de la Robinette) a été développée, avec comme but final de mieux comprendre le fonctionnement de l’écosystème et de mettre en évidence les mécanismes qui contribuent au dépérissement des forêts ou qui en sont la cause. La démarche générale consiste à modéliser les différents processus qui gouvernent les flux qui traversent l’écosystème forestier (représentation fonctionnelle de l’écosystème forestier). Cette démarche est le complément des études de terrain réalisées entre autres par le laboratoire d’écologie microbienne de l’ULg. Les éléments minéraux étant entrainés par l’eau, la modélisation de l’écosyst ème forestier est réalisée en deux sous-modèles couplés : • la modélisation du cycle hydrique, réalisée à l’aide d’un modèle global eau/énergie • la modélisation des différents échanges et flux des éléments minéraux (calcium, magnésium, …) Deux versions du modèle avaient été réalisées en 1987 (http://hdl.handle.net/2268/185068) et 1988 (http://hdl.handle.net/2268/185070). Dans le but de pouvoir simuler le devenir des éléments minéraux à la suite d’une coupe d’éclaircie, un sous-modèle de décomposition de litière a été ajouté au modèle (http://hdl.handle.net/2268/185072). Afin de pouvoir faire des simulations d’écosystèmes forestiers soumis à des traitements d’amendements, le modèle a encore été fortement modifié (entre autres pour simuler l’évolution des biomasses, http://hdl.handle.net/2268/185075). Ce rapport présente, d’une part une modification supplémentaire au modèle (prise en compte de l’eau capillaire) et d’autre part les résultats d’une simulation d’une fertilisation. [less ▲]

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See detailEtude comparée des parades sexuelles de quelques espèces de chéloniens: Pelomedusa s. subrufa (Lacépède), Sternotherus minor (Agassiz) et Kinixys belliana nogueyi (Bell)
Bels, Vincent; Libois, Roland ULg

in Cahiers d'Ethologie (1983), 3(1), 39-58

Next to a short analysis of the sexual interactions and the relative importance of the stimulation kinds performed with each behaviour pattern, we analyse the observed behavioural sequences in courtship ... [more ▼]

Next to a short analysis of the sexual interactions and the relative importance of the stimulation kinds performed with each behaviour pattern, we analyse the observed behavioural sequences in courtship and mating behaviour of three chelonian's species: Pelomedusa s. subrufa, Sternotherus minor and Kinixys belliana nogueyi. The study of the behavioural sequences emphasizes the great fluctiation between the exhibited behaviour patterns and specifies the means leading to the female's stabilization. The sexual behaviours (knowed from this study or the litterature) of P.s.subrufa, S. minor, K. belliana nogueyi, Geochelone carbonaria, Testudo g. graeca, Emys orbicularis, Chrysemys scripta elegans, Chemmys nigricans and Meosemys grandis were submitted to a discriminant analysis to establish certain phylogenetic relations by use of behavioural criteria. We emphasize here the difficulties of the interpretation of this lethod. However, we establish a relative ratification of the phylogeny founded on morphological characters. [less ▲]

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See detailEtude comparée du comportement de cour de Triturus alpestris alpestris (Laurenti, 1768) et Triturus alpestris cyreni (Wolterstorff, 1932) : approche évolutive
Denoël, Mathieu ULg

Master's dissertation (1996)

The species concept in the animal world is very abstract. With diverse methods scientists try to place boundaries between species. But this is generally theoretical. Indeed species are in continuous ... [more ▼]

The species concept in the animal world is very abstract. With diverse methods scientists try to place boundaries between species. But this is generally theoretical. Indeed species are in continuous evolution, located more regularly between two evolutionary categories than inside a well-defined one. In this study we are interested by the courtship of two allopatric subspecies of the Alpine newt, Triturus alpestris alpestris and T. a. cyreni. We investigate the behaviour of two closely related taxa, in experimental conditions, to display the basis of behaviour evolution and isolating mechanisms prominently. We have identified 24 behaviours in the male display and principally 3 in the female (negative, static, positive). Sexual encounter will be divided in four stages: orientation during which animals are meeting, fan and lean-in exhibition phases during which the male displays and the spermatophore transfer sequence where the male deposits a spermatophore and displays also. The qualitative differences between subspecies are weak and concern principally amplitude of movements. From a qualitative level some differences were underlined. So T. a. alpestris touches the female with its snout frequently, whereas T. a. cyreni whips more often. The two subspecies do not use the same tactic with a non-responsive female. Indeed the T. a. alpestris male can easily enter in spermatophore transfer phase without the positive response of female. In order to attract the latter, he executes worm-like movements: in this way he lures a negative female. On the contrary, T. a. cyreni rarely deposits a spermatophore when the female is not receptive. It therefore makes very little use of the lure system. The analysis of male behaviours in relation with female response have allowed us to establish a model which assumes that some behaviours are exhibited by the male only when its motivation and that of the female go beyond a particular level. Some stereotyped behaviours (e.g. distal fan) concern movements whose amplitude is variable. We think that this movement modulation could be the foundation of a behaviour evolution and isolating mechanism. The female is indeed sensitive to these variations: in this way communication is possible between transmitter and receiver. The new variants problem is thus resolved. The fanning frequencies vary with temperature. They are weak at low temperatures. We consider this modulation as an adaptation to extreme and unpredictable habitats, e.g. in high altitude lakes and temporary ponds. The observed behavioural differences are in a lower level than between separate species, like T. helveticus and T. vulgaris. Moreover sperm transfer is likely between the two taxa. In conclusion the present data confirm the existence of two distinct subspecies T. a. alpestris and T. a. cyreni as detected by previous authors using allozyme and osteological analysis. [less ▲]

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See detailEtude comparée du comportement de cour de Triturus alpestris alpestris (Laurenti, 1768) et Triturus alpestris cyreni (Wolterstorff, 1932) : approche évolutive.
Denoël, Mathieu ULg

Book published by Cahiers d'Ethologie (1996)

The species concept in the animal world is very abstract. With diverse methods scientists try to place boundaries between species. But this is generally theoretical. Indeed species are in continuous ... [more ▼]

The species concept in the animal world is very abstract. With diverse methods scientists try to place boundaries between species. But this is generally theoretical. Indeed species are in continuous evolution, located more regularly between two evolutionary categories than inside a well-defined one. In this study we are interested by the courtship of two allopatric subspecies of the Alpine newt, Triturus alpestris alpestris and T. a. cyreni. We investigate the behaviour of two closely related taxa, in experimental conditions, to display the basis of behaviour evolution and isolating mechanisms prominently. We have identified 24 behaviours in the male display and principally 3 in the female (negative, static, positive). Sexual encounter will be divided in four stages: orientation during which animals are meeting, fan and lean-in exhibition phases during which the male displays and the spermatophore transfer sequence where the male deposits a spermatophore and displays also. The qualitative differences between subspecies are weak and concern principally amplitude of movements. From a qualitative level some differences were underlined. So T. a. alpestris touches the female with its snout frequently, whereas T. a. cyreni whips more often. The two subspecies do not use the same tactic with a non-responsive female. Indeed the T. a. alpestris male can easily enter in spermatophore transfer phase without the positive response of female. In order to attract the latter, he executes worm-like movements: in this way he lures a negative female. On the contrary, T. a. cyreni rarely deposits a spermatophore when the female is not receptive. It therefore makes very little use of the lure system. The analysis of male behaviours in relation with female response have allowed us to establish a model which assumes that some behaviours are exhibited by the male only when its motivation and that of the female go beyond a particular level. Some stereotyped behaviours (e.g. distal fan) concern movements whose amplitude is variable. We think that this movement modulation could be the foundation of a behaviour evolution and isolating mechanism. The female is indeed sensitive to these variations: in this way communication is possible between transmitter and receiver. The new variants problem is thus resolved. The fanning frequencies vary with temperature. They are weak at low temperatures. We consider this modulation as an adaptation to extreme and unpredictable habitats, e.g. in high altitude lakes and temporary ponds. The observed behavioural differences are in a lower level than between separate species, like T. helveticus and T. vulgaris. Moreover sperm transfer is likely between the two taxa. In conclusion the present data confirm the existence of two distinct subspecies T. a. alpestris and T. a. cyreni as detected by previous authors using allozyme and osteological analysis. [less ▲]

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See detailEtude complémentaire de la cytotoxicite de la mélinonine F, alcaloide dérive de la beta-carboline
Bassleer, Roger ULg; Marnette, J. M.; Wiliquet, P. et al

in Planta Medica (1983), 49(11), 158-161

The cellular effects of melinonine F, an alkaloid isolated from STRYCHNOS MELINONIANA (South America) and STRYCHNOS USAMBARENSIS (Central Africa), are analysed in cancer or normal cells in culture. A ... [more ▼]

The cellular effects of melinonine F, an alkaloid isolated from STRYCHNOS MELINONIANA (South America) and STRYCHNOS USAMBARENSIS (Central Africa), are analysed in cancer or normal cells in culture. A cytotoxic action is noted in both types of cells, at least for relatively high concentrations. These effects are probably due to interaction of the drug with chromatin. Physico-chemical analysis demonstrates partial intercalation of melinonine F on pure DNA IN VITRO. [less ▲]

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See detailEtude complémentaire relative aux profils d'accessibilité - profils de mobilité
Daxhelet, Delphine; Kessler, Laurent; Lambotte, Jean-Marc ULg et al

Report (2002)

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See detailEtude complète d'une unité de sauvetage fluvial de grande puissance
Marchal, Jean ULg; Rodriguez, S.

Report (1980)

Detailed reference viewed: 13 (0 ULg)
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See detailÉtude concernant le secteur du logement privé en Belgique, dans le cadre du Baromètre de la diversite
Loopmans, Maarten; Minon, Caroline; Perrin, Nathalie ULg et al

in Centre Interfédéral pour l'Egalité des Chances (Ed.) Baromètre de la diversité - Logement (2014)

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See detailEtude contrastive de la notion temps/aspect dans les langues indo-européennes
Mouton, Charles ULg

in Slavica Gandensia (1998), (25/1), 29-41

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See detailEtude couplée pharmacocinétique et urodynamique de l'administration orale de différents dosages de phenylpropanolamine chez la chienne continente.
Noël, Stéphanie ULg

Master of advanced studies dissertation (2007)

The goal of this study is to establish the pharmacokinetic characteristics of oral administration of phenylpropanolamine at different dosages (1.5 mg/Kg once a day and three times a day), in continent ... [more ▼]

The goal of this study is to establish the pharmacokinetic characteristics of oral administration of phenylpropanolamine at different dosages (1.5 mg/Kg once a day and three times a day), in continent bitches, and to assess the associated urodynamic effects. The influence of phenylpropanolamine on systemic arterial pressure and heart rate is also studied. Maximal concentration appears two hours after the administration of phenylpropanolamine. Since the half-life lasts four hours and due to a mechanism of accumulation, a repeated daily administration induces an increase of the maximal concentration after each administration. After one week of a single administration of phenylpropanolamine per day, an increased urethral resistance and functional profile length are observed at the time of maximal concentration. This increase could explain the successful treatment of incontinent bitches with a single daily administration of phenylpropanolamine. However, a repeated administration of phenylpropanolamine three times a day does not increase the urethral resistance, probably after desensitization of the adrenergic receptors. The increase in arterial pressure after the administration of phenylpropanolamine is compensated by a decreased heart rate occurring at the time of maximal concentration. [less ▲]

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