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See detailBasaltic volcanism and mass extinction at the Permo-Triassic boundary: Environmental impact and modeling of the global carbon cycle
Grard, Aline ULg; François, Louis ULg; Dessert, C. et al

in Earth And Planetary Science Letters (2005), 234(1-2), 207-221

The Siberian Traps represent one of the most voluminous continental flood basalt provinces on Earth. The mass extinction at the end of the Permian was the most severe in the history of life. In the ... [more ▼]

The Siberian Traps represent one of the most voluminous continental flood basalt provinces on Earth. The mass extinction at the end of the Permian was the most severe in the history of life. In the present paper, these two major concurrent events that occurred are analysed and a geochemical model coupled with an energy balance model is used to calculate their environmental impact on atmospheric CO2, oceanic delta(13)C, and marine anoxia. The latitudinal temperature gradient is reduced relative to today, resulting in warmer temperatures at high latitudes. The warmer climate and the presence of fresh basaltic provinces increase the weatherability of the continental surfaces, resulting in an enhanced consumption of atmospheric CO2 through weathering. First, the eruption of the Siberian traps is accompanied by a massive volume of C-13 depleted CO2 degassed from the mantle and added to the ocean through silicate weathering, thus lowering marine delta(13)C. Second, the rapid collapse in productivity induces a strong decrease in the global organic carbon burial. This too tends to increase the proportion of light carbon in the ocean. These two effects can explain the low delta(13)C values across the PT boundary, and methane release need not be invoked to explain the delta(13)C fluctuations. It is proposed that the phosphorus cycle, which drives primary production in the model, plays an important role on the recovery of productivity and the delta(13)C variations. (c) 2005 Elsevier B.V All rights reserved. [less ▲]

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See detailBase de calcul pour le dimensionnement d'une tour de refroidissement à tirage naturel
Nicolas, Jacques ULg; Vasel, Jean-Luc ULg

in European Journal of Mechanical and Environmental Engineering (1992), 37

Le but de cet article est de fournir de façon exhaustive l'ensemble des relations qui permettent le calcul des transferts thermiques dans une tour de refroidissemenmt à contrecourant et à tirage naturel ... [more ▼]

Le but de cet article est de fournir de façon exhaustive l'ensemble des relations qui permettent le calcul des transferts thermiques dans une tour de refroidissemenmt à contrecourant et à tirage naturel. L'article se base sur les approches classiques décrites dans la littérature (Merkel, Chilton, Braun, ...), mais en uniformisant les symboles et les unités, de façon à fournir en un seul texte tous les éléments qui permettent de modéliser, pour des besoins de contrôle ou de dimensionnement, une tour de refroidissement et d'en estimer les performances.Quelques pratiques d'utilisation de ces relations sont étudiées, ainsi qu'une confrontation de différentes méthodes de résolution sur un même exemple. [less ▲]

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See detailBase de données des relevés phytosociologiques
Dufrêne, Marc ULg

Textual, factual or bibliographical database (2012)

Detailed reference viewed: 26 (3 ULg)
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See detailLa base de données du CIEL
Dozo, Björn-Olav ULg; Vanderpelen, Cécile

Conference (2008, December 04)

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See detailBase de données du Collectif interuniversitaire d'étude du littéraire (CIEL)
Dozo, Björn-Olav ULg; CIEL (Collectif interuniversitaire d'étude du littéraire)

Textual, factual or bibliographical database (2009)

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See detailBase de données mortalité et étude du régime alimentaire (Balbuzard)
Rosoux, René; Libois, Roland ULg; Schweyer, Jean Baptiste

Learning material (2010)

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See detailBase de données PMI - stratégie, exportation, innovation
Choffray, Jean-Marie ULg; Pras, Bernard; Roux, Elyette

Book published by FNEGE/ESSEC (1994)

Detailed reference viewed: 59 (5 ULg)
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See detailBase de données sols de REQUASUD - 3ème synthèse
Genot, Valérie ULg; Renneson, Malorie ULg; Colinet, Gilles ULg et al

Book published by ASBL REQUASUD - D/2012/8689/1 (2012)

Detailed reference viewed: 42 (16 ULg)
See detailBase de données sur les métiers du livre au Québec
Dozo, Björn-Olav ULg; Melançon, François; GRÉLQ (Groupe de recherche sur l'édition littéraire au Québec)

Textual, factual or bibliographical database (2010)

Detailed reference viewed: 18 (2 ULg)
See detailBase de données sur les prix artistiques dans l'entre-deux-guerres au Québec
Dozo, Björn-Olav ULg; Lapointe, Olivier

Textual, factual or bibliographical database (2008)

Detailed reference viewed: 18 (2 ULg)
See detailBase de la Politique Agricole Commune
Burny, Philippe ULg

Conference given outside the academic context (1995)

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See detailThe base for direct taxation: commentary
Pestieau, Pierre ULg

in Banks, J.; Diamond, P.; Mirrlees, J. (Eds.) The tax base for direct taxation (2008)

The chapter of J. Banks, P. Diamond and J. Mirrlees (BDM) presents an excellent survey of the existing literature on optimal taxation and discusses a number of lessons that can be drawn from that ... [more ▼]

The chapter of J. Banks, P. Diamond and J. Mirrlees (BDM) presents an excellent survey of the existing literature on optimal taxation and discusses a number of lessons that can be drawn from that literature. One of the main lessons on which their chapter focuses concerns the treatment of capital income. The authors argue that the finding that the optimal income tax schedule should not include tax on capital is based on too many restrictions, and is thus not robust for policy purposes. Another lesson is that taxation should vary with age. Not having any quarrel with these two points, I would like in this comment to discuss a number of points too quickly dealt with or deliberately neglected by BDM. They concern the issue of tagging, the problem raised by having more than one unobservable characteristic (besides ability), the issue of myopia and prodigality, the question of equal opportunities, the taxation of couples and the threat of tax competition [less ▲]

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See detailBase plate in bending and anchor bolts in tension
Wald, F.; Sokil, Z.; Jaspart, Jean-Pierre ULg

in Heron (2008), 53(1/2),

This paper describes the behaviour of the base plate in bending and the anchor bolts in tension, which are the major components of a base plate connection. An analytical model has been derived to predict ... [more ▼]

This paper describes the behaviour of the base plate in bending and the anchor bolts in tension, which are the major components of a base plate connection. An analytical model has been derived to predict the component characteristics – the resistance and the stiffness. A description is given of how the behaviour is influenced by contact between the base plate and the concrete surface. The presented analytical model has been verified by tests and a finite element simulation. [less ▲]

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See detailBase-dependent electron photodetachment from negatively charged DNA strands upon 260-nm laser irradiation
Gabelica, Valérie ULg; Rosu, Frédéric ULg; Tabarin, Thibault et al

in Journal of the American Chemical Society (2007), 129(15), 4706-4713

DNA multiply charged anions stored in a quadrupole ion trap undergo one-photon electron ejection (oxidation) when subjected to laser irradiation at 260 nm (4.77 eV). Electron photodetachment is likely a ... [more ▼]

DNA multiply charged anions stored in a quadrupole ion trap undergo one-photon electron ejection (oxidation) when subjected to laser irradiation at 260 nm (4.77 eV). Electron photodetachment is likely a fast process, given that photodetachment is able to compete with internal conversion or radiative relaxation to the ground state. The DNA [6-mer](3-) ions studied here show a marked sequence dependence of electron photodetachment yield. Remarkably, the photodetachment yield (dG(6) > dA(6) > dC(6) > dT(6)) is inversely correlated with the base ionization potentials (G < A < C < T). Sequences with guanine runs show increased photodetachment yield as the number of guanine increases, in line with the fact that positive holes are the most stable in guanine runs. This correlation between photodetachment yield and the stability of the base radical may be explained by tunneling of the electron through the repulsive Coulomb barrier. Theoretical calculations on dinucleotide monophosphates show that the HOMO and HOMO-1 orbitals are localized on the bases. The wavelength dependence of electron detachment yield was studied for dG(6)(3-). Maximum electron photodetachment is observed in the wavelength range corresponding to base absorption (260-270 nm). This demonstrates the feasibility of gas-phase UV spectroscopy on large DNA anions. The calculations and the wavelength dependence suggest that the electron photodetachment is initiated at the bases and not at the phosphates. This also indicates that, although direct photodetachment could also occur, autodetachment from excited states, presumably corresponding to base excitation, is the dominant process at 260 nm. Excited-state dynamics of large DNA strands still remains largely unexplored, and photo-oxidation studies on trapped DNA multiply charged anions can help in bridging the gap between gas-phase studies on isolated bases or base pairs and solution-phase studies on full DNA strands. [less ▲]

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See detailBaseline brain activity fluctuations predict somatosensory perception in humans
Boly, Mélanie ULg; Balteau, Evelyne ULg; Schnakers, Caroline ULg et al

in Proceedings of the National Academy of Sciences of the United States of America (2007), 104(29), 12187-12192

In perceptual experiments, within-individual fluctuations in perception are observed across multiple presentations of the same stimuli, a phenomenon that remains only partially understood. Here, by means ... [more ▼]

In perceptual experiments, within-individual fluctuations in perception are observed across multiple presentations of the same stimuli, a phenomenon that remains only partially understood. Here, by means of thulium-yttrium/aluminum- garnet laser and event-related functional MRI, we tested whether variability in perception of identical stimuli relates to differences in prestimulus, baseline brain activity. Results indicate a positive relationship between conscious perception of low-intensity somatosensory stimuli and immediately preceding levels of baseline activity in medial thalamus and the lateral frontoparietal network, respectively, which are thought to relate to vigilance and "external monitoring." Conversely, there was a negative correlation between subsequent reporting of conscious perception and baseline activity in a set of regions encompassing posterior cingulate/ precuneus and temporoparietal cortices, possibly relating to introspection and self-oriented processes. At nociceptive levels of stimulation, pain-intensity ratings positively correlated with baseline fluctuations in anterior cingulate cortex in an area known to be involved in the affective dimension of pain. These results suggest that baseline brain-activity fluctuations may profoundly modify our conscious perception of the external world. [less ▲]

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See detailBaseline data on cyanobacterial diversity near the new Princess Elizabeth Antarctic research station.
Fernandez Carazo, Rafael ULg; Namsaraev, Zorigto; Ertz, Damien et al

Poster (2009, July 27)

Detailed reference viewed: 14 (5 ULg)