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See detailMesozoic marine crises and ichthyosaur history: a non-direct relationship
Fischer, Valentin ULg

Conference (2014, October)

Marine ecosystems underwent several profound crises throughout the Mesozoic; many of them are correlated with supra-regional to worldwide anoxic events. The impact of these crises is relatively well ... [more ▼]

Marine ecosystems underwent several profound crises throughout the Mesozoic; many of them are correlated with supra-regional to worldwide anoxic events. The impact of these crises is relatively well understood among animals occupying lower trophic levels but their influence on top predators of that time, fishes and marine reptiles, remains unclear. The fossil record of marine reptiles is of fluctuating quality but thoroughly revised taxonomic and phylogenetic frameworks now allow assessment of the influence of past climatic and oceanic changes on these top predators, by quantifying their cladogenesis and extinction rates across selected intervals. Here, I focus on ichthyosaurs, a successful clade of marine reptiles that colonized marine ecosystems during most of the Mesozoic. The ichthyosaur record indicates relatively few severe turnovers and a non direct relationship with environmental drivers, notably anoxic events. New fossils from France reveal the middle-late Norian extinctions did not eradicate the clade of whale-sized shastasaurid ichthyosaurs; similarly, the severe early Toarcian anoxic event, the end-Jurassic climate changes and several Cretaceous anoxic events did not impacted ichthyosaurs significantly, at least at the suprageneric level. On the other hand, severe turnovers or extinctions occurred during the latest Triassic and the Cenomanian and are coincident with a number of profound environmental and biotic changes. This indicates that unique drivers fail to explain the turnover patterns in ichthyosaur evolutionary history. Notably, oceanic anoxic events only impacted ichthyosaurs during the end-Cenomanian and did so during a period of intense climatic and biological upheavals. These major crises in ichthyosaur history are seemingly protracted over several million years and are probably best explained by a conjunction of causes. This is part of a wider project that will incorporate data from other contemporaneous groups to shed a new light on the general turnover patterns among marine top predators of the Mesozoic and the influence of ancient environmental changes in shaping their biodiversity. [less ▲]

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See detailMesozoic marine reptile palaeobiogeography in response to drifting plates
Bardet, Nathalie; Falconnet, Jocelyn; Fischer, Valentin ULg et al

in Gondwana Research (2014)

During the Mesozoic, various groups of reptiles underwent a spectacular return to an aquatic life, colonizing most marine environments. They were highly diversified both systematically and ecologically ... [more ▼]

During the Mesozoic, various groups of reptiles underwent a spectacular return to an aquatic life, colonizing most marine environments. They were highly diversified both systematically and ecologically, and most were the largest top-predators of the marine ecosystems of their time. The main groups were Ichthyosauria, Sauropterygia, Thalattosauria, and several lineages of Testudinata, Crocodyliformes, Rhynchocephalia and Squamata. Here we show that the palaeobiogeographical distribution of these marine reptiles closely followed the break-up of the supercontinent Pangaea and that they globally used the main marine corridors created by this break-up to disperse. Most Mesozoic marine reptile clades exhibit a cosmopolitan, or at least pandemic, distribution very early in their evolutionary history. The acquisition of morphological adaptations to a fully aquatic life, combined to special thermophysiological characteristics, are probably responsible for these animals to become efficient long-distance open-marine cruisers. Generally, Early Triassic taxa were near-shore animals mainly linked to the Tethys or Panthalassa coastlines. By the end of the Triassic and during the Jurassic, the break-up of Pangaea resulted in the formation of large marine corridors connecting the Tethys to the North Atlantic and Pacific realms, a trend increasing on during the Cretaceous with the expansion of the Atlantic Ocean and the break-up of the southern Gondwana, allowing open-sea marine reptiles to spread out over large distances. However, if large faunal interchanges were possible at a global scale following a dispersal model, some provinces, such as the Mediterranean Tethys, were characterized by a peculiar faunal identity, illustrating an absence of migration with time despite the apparent lack of barriers. So, if Continental Drift enabled global circulations and faunal interchanges via dispersals among Mesozoic marine reptiles, others parameters, such as ecological and biological constraints, probably also played a role in the local endemic distribution of some of these marine groups, as they do today. [less ▲]

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See detailMesozoic marine reptile palaeobiogeography in response to drifting plates
Bardet, Nathalie; Fischer, Valentin ULg; Houssaye, Alexandra et al

Conference (2012, September)

Mesosaurus Broom, 1913, from the Early Permian, is the first aquatic reptile known in the fossil record. Its co-occurrence in both South Africa (South Africa) and South America (Brazil, Uruguay) made it ... [more ▼]

Mesosaurus Broom, 1913, from the Early Permian, is the first aquatic reptile known in the fossil record. Its co-occurrence in both South Africa (South Africa) and South America (Brazil, Uruguay) made it one of the key-fossils - with the pteridospermatophyta plant Glossopteris - used by the German meteorologist / geophysician Alfred Wegener to support his theory of the Continental Drift (Kontinentalverschiebung), first published in 1912. But Mesosaurus was only the “tip of the iceberg” as, during the Mesozoic, various clades of reptiles massively invaded the aquatic, and more especially, the marine realm. They were highly diversified both systematically and ecologically, and some of them were large top-predators of the marine ecosystems. The main groups were, in order of appearance in the fossil record, Ichthyosauria (earliest Triassic – early Late Cretaceous), Sauropterygia (nothosaurs, pachypleurosaurs, placodonts, plesiosaurs; Early Triassic – latest Cretaceous), Thalattosauria (Middle-Late Triassic), Pleurosauria (Early Jurassic–Early Cretaceous), as well as, among others, several lineages of Chelonians (e.g. chelonioids, bothremydids, “thalassemyds”), Crocodyliformes (thalattosuchians, dyrosaurids, pholidosaurids, gavialoids) and Squamates (mosasauroids, “dolichosaurs”, marine snakes). During the Mesozoic, the palaeobiogeographical distributions and the dispersion events of these marine reptiles closely followed the break-off of the Pangea induced by plate tectonic movements. Although marine reptiles can help in determining the possible date of opening of marine corridors, the information they provide are less precise than that delivered by terrestrial faunas, as the marine realm is a more open system and various migration ways are always possible. Generally, the Triassic taxa were animals with a restricted palaeobiogeographical distribution living near the coastlines of the Pangea. From the end of the Triassic and during the Jurassic, the break-off of the Pangea resulted in the formation of large marine corridors, allowing open-sea marine reptiles such as ichthyosaurs, plesiosaurs and crocodyliformes to spread out over large distances. As an example, similar marine reptile faunas are known from the Jurassic of Europe and southern South America, as a result of dispersion events via the Hispanic Corridor that connected the Tethys / North Atlantic and Pacific realms at this time. During the Cretaceous, and notably with the expansion of the Atlantic Ocean, most of these reptiles were cosmopolite and open-sea forms (plesiosaurs, mosasaurid squamates, chelonioid turtles). However, even if large faunal interchanges were possible, some provinces such as the Northern and Southern margins of the Tethys were characterized by a peculiar faunal identity, notably concerning mosasaurids, despite the apparent absence of barriers. So, if Continental Drift enabled circulation and faunal interchanges, other parameters such as ecological constraints probably also played a role in the distribution of these marine reptile faunas. [less ▲]

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See detailMESS (Mass-loss of Evolved StarS), a Herschel Key Program
Groenewegen, M. A. T.; Waelkens, C.; Barlow, M. J. et al

in Astronomy and Astrophysics (2011), 526

MESS (Mass-loss of Evolved StarS) is a Guaranteed Time Key Program that uses the PACS and SPIRE instruments on board the Herschel Space Observatory to observe a representative sample of evolved stars ... [more ▼]

MESS (Mass-loss of Evolved StarS) is a Guaranteed Time Key Program that uses the PACS and SPIRE instruments on board the Herschel Space Observatory to observe a representative sample of evolved stars, that include asymptotic giant branch (AGB) and post-AGB stars, planetary nebulae and red supergiants, as well as luminous blue variables, Wolf-Rayet stars and supernova remnants. In total, of order 150 objects are observed in imaging and about 50 objects in spectroscopy. This paper describes the target selection and target list, and the observing strategy. Key science projects are described, and illustrated using results obtained during Herschel's science demonstration phase. Aperture photometry is given for the 70 AGB and post-AGB stars observed up to October 17, 2010, which constitutes the largest single uniform database of far-IR and sub-mm fluxes for late-type stars. [less ▲]

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See detailMessage et ambassade chez les historiens latins : une approche lexicométrique
Longrée, Dominique ULg

in Jacquin, Gérard (Ed.) Récits d'ambassades et figures du messager (2007)

Detailed reference viewed: 21 (1 ULg)
See detailMessage reçu. Prévoyons traitement longue durée. Espérons aide efficace.
Dumortier, Jean-Louis ULg

in Promotion de l'Enseignement en Français (1988)

Detailed reference viewed: 3 (0 ULg)
See detailLe Messager du Livre. Genèses de Mallarmé
Durand, Pascal ULg

Doctoral thesis (1994)

Detailed reference viewed: 44 (19 ULg)
Peer Reviewed
See detailUn messager intercellulaire original, le NO (monoxyde d'azote)
Liégeois, Jean-François ULg; Damas, Jacques ULg

in Revue Médicale de Liège (1993), 48(7), 406-13

Detailed reference viewed: 10 (2 ULg)
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See detailLes messagers de la floraison
Périlleux, Claire ULg

Conference given outside the academic context (2005)

Detailed reference viewed: 5 (0 ULg)
Peer Reviewed
See detailMessenger RNA expression for a TSH receptor variant in the thymus of a two-year old child
Paschke, Ralf; Geenen, Vincent ULg

in Journal of Molecular Medicine (1995), 73577-580

We recently described the presence of a TSH receptor variant in orbital tissues. The presence of this TSH receptor variant in the thymus suggests that induction of immune tolerance to this TSH receptor ... [more ▼]

We recently described the presence of a TSH receptor variant in orbital tissues. The presence of this TSH receptor variant in the thymus suggests that induction of immune tolerance to this TSH receptor-transcript is possible. A lack of tolerance induction for this TSH receptor variant could provide an explanation for a possible antigenic link between Graves' disease and thyroid-associated orbitopathy. [less ▲]

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See detailLes messicoles, fleurs des moissons
Legast, Marie ULg; Mahy, Grégory ULg; Bodson, Bernard ULg

Book published by Claude Delbeuck/Direction générale de l'Agriculture (2008)

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See detailMessinian vegetation maps of the Mediterranean region using models and interpolated pollen data
Favre, Eric ULg; François, Louis ULg; Fluteau, Frederic et al

in Geobios (2007), 40(3), 433-443

This study proposes to compare the outputs from the CARAIB vegetation model forced by results from the LMD General Circulation Model with interpolated pollen data (Kriging method) from the Mediterranean ... [more ▼]

This study proposes to compare the outputs from the CARAIB vegetation model forced by results from the LMD General Circulation Model with interpolated pollen data (Kriging method) from the Mediterranean region during the Messinian. The vegetation maps that have been obtained represent distinct phases of the salinity crisis: before the crisis and during the marginal evaporitic phase (interpolated map), and during the complete desiccation phase (simulated map). However, they are comparable in terms of vegetation density and agree on a strong contrast between the Northern (forest vegetation) and Southern (open vegetation) Mediterranean regions. Main differences concern the type of forests in the northern Mediterranean region, which are explained by discrepancies between precipitation amount predicted by the model and that calculated by a transfer function using pollen records. The interpolation method has been successfully tested in France using interpolated current pollen records by comparison with the present-day potential vegetation map. The resulting Messinian map is useful to validate or improve model simulation which does not take into account the depth of the Mediterranean Basin when it dried up. The Southern Mediterranean landscapes were open, with a steppe-like vegetation to the West and a savannah-like vegetation to the East. Forests prevailed to the North, organized in a mosaic system mainly controlled by relief. Such a contrast provides some explanation of the large number of deep fluvial canyons cut on the Northern margin at opposed to the South during the Mediterranean desiccation. (C) 2007 Elsevier Masson SAS. All rights reserved. [less ▲]

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See detailLa mesure ambulatoire de la pression artérielle permet d'améliorer la définition de l'hypertension artérielle
Warling, X.; Carlier, P. G.; Krzesinski, Jean-Marie ULg et al

in Archives des Maladies du Coeur et des Vaisseaux (1988), 81 Spec No

The lack of effect of treatment of mild hypertension on the coronary heart disease has motivated researches for a better diagnosis of hypertension. One of the approaches presently under study uses the ... [more ▼]

The lack of effect of treatment of mild hypertension on the coronary heart disease has motivated researches for a better diagnosis of hypertension. One of the approaches presently under study uses the recording of ambulatory blood pressure using semi-automatic devices. The usefulness of these apparatus is however restricted by the lack of reference values recorded in normotensive control patients. We have recorded ambulatory blood pressure (PAA) in 24 normotensives, 22 untreated hypertensives and 45 treated hypertensive patients, and compared the data obtained to the blood pressure recorded during medical examination (PAC). If a good correlation is usually observed between PAA and PAC, very large and unpredictable discordances are frequently observed. No correlation is found between the difference PAA-PAC and the variability of PAA. This variability does not fully explain the difference observed between PAA and PAC. This variability expressed in mmHg increases with age and the level of BP. Ambulatory BP appears to be a very reproducible value which may allow to improve the definition of hypertension and therefore the cardiovascular risk. [less ▲]

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See detailMesure ambulatoire de la pression artérielle, son utilité en pratique quotidienne
Krzesinski, Jean-Marie ULg

in Revue Médicale de Liège (1994), 49(9), 475-480

Si la nécessité du traitement de l'hypertension artérielle est un fait accepté de façon universelle, la question à propos des niveaux de pression artérielle qui méritent une intervention reste débattue ... [more ▼]

Si la nécessité du traitement de l'hypertension artérielle est un fait accepté de façon universelle, la question à propos des niveaux de pression artérielle qui méritent une intervention reste débattue. Cette difficulté trouve son origine dans une telle variabilité de la pression artérielle que les mesures au cabinet de consultation représentent seulement une vue limitée de son réel profil sur 24 heures. Le développement d'enregistreurs portatifs de la pression artérielle par méthode non invasive a permis d'étudier la variabilité remarquable de cette pression artérielle tout au long des activités habituelles des patients. Bien que cette technique de mesure ambulatoire de la pression artérielle (MAPA) ne remplace pas la mesure traditionnelle de la pression artérielle, elle s'impose de plus en plus comme complément indispensable et non invasif dans certaines indications cliniques spécifiques (hypertensions de la blouse blanche, limite, réfractaire, ou encore vérification de l'efficacité du contrôle tensionnel). [less ▲]

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See detailMesure de coefficient de dilatation thermique de matériaux composites par holographie dynamique
Georges, Marc ULg; Ryhon, S.; Thizy, Cédric ULg et al

in Actes du 3e colloque francophone Méthodes et Techniques Optiques pour l'Industrie (2002, November)

Une méthode de mesure de coefficient de dilatation thermique par interférométrie holographique est présentée. Nous passerons rapidement en revue le principe de la caméra holographique dynamique utilisée ... [more ▼]

Une méthode de mesure de coefficient de dilatation thermique par interférométrie holographique est présentée. Nous passerons rapidement en revue le principe de la caméra holographique dynamique utilisée pour la mesure puis nous montrerons l’application à plusieurs cas concrets de R&D industriels. Il s’agit d’éprouvettes simples de matériaux composite et de structures plus complexes alliant ces matériaux à des métaux. La mesure consiste à observer le déplacement différentiel entre la partie supérieure de l’objet étudié et une plaque de base sur laquelle il est posé et ce lorsqu’un échauffement ou refroidissement de l’ensemble est opéré [less ▲]

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See detailMesure de l'effet de l'hyperimmunisation pour le contrôle de la rhinotrachéite infectieuse bovine dans les troupeaux laitiers en Belgique : analyse de survie
Dispas, Marc; Kerkhofs, Pierre; Thiry, Etienne ULg

in Epidémiologie et Santé Animale (2003), 44

Detailed reference viewed: 11 (1 ULg)