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See detailDissolved inorganic carbon dynamics and air-sea carbon dioxide fluxes during coccolithophorid blooms in the Northeast European continental margin (northern Bay of Biscay)
Suykens, Kim; Delille, Bruno ULg; Chou, Lei et al

Poster (2010, May 03)

Balch et al. (2007) evaluated global pelagic contemporary calcification from remote sensing data (mainly associated to coccolithophores) to 1.6 ± 0.3 Pg PIC yr-1 (1 Pg = 1015 g; PIC = particulate ... [more ▼]

Balch et al. (2007) evaluated global pelagic contemporary calcification from remote sensing data (mainly associated to coccolithophores) to 1.6 ± 0.3 Pg PIC yr-1 (1 Pg = 1015 g; PIC = particulate inorganic carbon). This would imply that coccolithophores would be the most important pelagic calcifier in the oceans, since other estimates of contemporary global pelagic calcification range between 0.7 Pg PIC yr-1 based on accumulation rates and sediment trap data (Milliman et al. 1999), and 1.4 Pg PIC yr-1, based on the seasonal cycle of total alkalinity (TA) in the euphotic zone (Lee 2001). The development of coccolithophorid blooms affects the seawater carbonate chemistry, and air-sea CO2 fluxes, through the organic carbon pump and the carbonate counter-pump. The ratio between calcification (carbonate counter-pump), and organic carbon production (organic carbon pump), the C:P ratio, depends on the life cycle (bloom development), and growth conditions of coccolithophores. At the onset of the coccolithophorid bloom, when nutrients are available for growth, organic carbon production dominates over calcification (C:P << 1, the so-called organic phase). At the end of the bloom, in nutrient depleted conditions, and high irradiances (due to stronger stratification), organic carbon production decreases and calcification increases (C:P ≤ 1, the so-called inorganic phase). Several manipulative experiments to test the effect of ocean acidification on coccolithophores have shown that while calcification would decrease, the export of organic carbon would increase mainly through increasing transparent exopolymer particles (TEP) production. For a credible implementation in mathematical models of such feed-back mechanisms to allow the projection of a future evolution of carbon biogeochemistry under global change, it is required to understand present day biogeochemistry and ecology of naturally occurring pelagic calcifying communities. In particular, the overall effect of phytoplankton communities on the C:P ratio, and the net effect on carbonate chemistry, and related air-sea CO2 fluxes. [less ▲]

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See detailDissolved inorganic carbon dynamics and air-sea carbon dioxide fluxes during coccolithophorid blooms in the Northeast European continental margin (northern Bay of Biscay)
Suykens, Kim; Delille, Bruno ULg; Chou, Lei et al

Poster (2010, May 02)

We present a data-set of dissolved inorganic carbon (DIC) obtained during three cruises in the northern Bay of Biscay carried out in June 2006, May 2007, and May 2008. During these cruises, blooms of ... [more ▼]

We present a data-set of dissolved inorganic carbon (DIC) obtained during three cruises in the northern Bay of Biscay carried out in June 2006, May 2007, and May 2008. During these cruises, blooms of coccolithophores occurred, as indicated by patches of high reflectance on remote sensing images, phytoplankton pigment signatures, and microscopic examinations. Total alkalinity (TA) showed a non-conservative behaviour as a function of salinity due to the cumulated effect of net community calcification (NCC) during bloom development on seawater carbonate chemistry. The cumulated impact of NCC and net community production (NCP) on DIC and the partial pressure of CO2 (pCO2) were evaluated. The decrease of DIC (and increase of pCO2) due to NCC was overwhelmingly lower than the decrease of DIC (and decrease of pCO2) due to NCP (NCC:NCP « 1). During the cruises, the northern Bay of Biscay acted as a sink of atmospheric CO2 (on average -9.7 mmol C m-2 d-1 for the 3 cruises). The overall effect of NCC in decreasing the CO2 sink during the cruises was low (on average 12% of total air-sea CO2 flux). If this is a general feature in naturally occurring phytoplankton blooms in the northern North Atlantic Ocean (where coccolithophorid blooms are the most intense and recurrent), and in the global ocean, then the potential feed-back on increasing atmospheric CO2 of the projected decrease of pelagic calcification due to thermodynamic CO2 “production” from calcification is probably minor compared to feed-backs related to changes of NCP. [less ▲]

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See detailDissolved inorganic carbon dynamics in the Gulf of Biscay (June 2006)
Suykens, K.; Delille, Bruno ULg; Borges, Alberto ULg

Poster (2007, April)

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See detailDissolved Inorganic Carbon dynamics in the northern Bay of Biscay during a Coccolithophore bloom
Harlay, Jérôme ULg; van der Zee, Claar; Schiettecatte, Laure-Sophie et al

Poster (2005, May 02)

In the framework of the Belgian global change programme, we have developed a project devoted to the study of the inorganic carbon cycle in the Bay of Biscay where coccolithophore blooms occur frequently ... [more ▼]

In the framework of the Belgian global change programme, we have developed a project devoted to the study of the inorganic carbon cycle in the Bay of Biscay where coccolithophore blooms occur frequently. The study focuses on processes associated with the oceanic production and dissolution of calcium carbonate and related CO2 fluxes. Real time remote sensing allowed to localize the coccolithophore bloom that the R.V. Belgica visited in June 2004 during a multidisciplinary scientific cruise. We will present vertical profiles of pH, Talk, along with other parameters (salinity, temperature, chlorophyll a and phaeopigments) and 14C incorporation experiments. Inorganic carbon fluxes will be discussed in the photic zone, in correlation with the biological activity of phytoplankton (biological and carbonate pumps). [less ▲]

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See detailDissolved inorganic carbon dynamics in the waters surrounding forested mangroves of the Ca Mau Province (Vietnam)
Koné, J. M.; Borges, Alberto ULg

in Estuarine Coastal & Shelf Science (2008), 7(3), 409-421

Dissolved inorganic carbon (DIC) and ancillary data were obtained during the dry and rainy seasons in the waters surrounding two 10-yearold forested mangrove sites (Tam Giang and Kieˆn Va`ng) located in ... [more ▼]

Dissolved inorganic carbon (DIC) and ancillary data were obtained during the dry and rainy seasons in the waters surrounding two 10-yearold forested mangrove sites (Tam Giang and Kieˆn Va`ng) located in the Ca Mau Province (South-West Vietnam). During both seasons, the spatial variations of partial pressure of CO2 (pCO2) were marked, with values ranging from 704 ppm to 11481 ppm during the dry season, and from 1209 ppm to 8136 ppm during the rainy season. During both seasons, DIC, pCO2, total alkalinity (TAlk) and oxygen saturation levels (%O2) were correlated with salinity in the mangrove creeks suggesting that a combination of lower water volume and longer residence time (leading to an increase in salinity due to evaporation) enhanced the enrichment in DIC, pCO2 and TAlk, and an impoverishment in O2. The low O2 and high DIC and pCO2 values suggest that heterotrophic processes in the water column and sediments controlled these variables. The latter processes were meaningful since the high DIC and TAlk values in the creek waters were related to some extent to the influx of pore waters, consistent with previous observations. This was confirmed by the stochiometric relationship between TAlk and DIC that shows that anaerobic processes control these variables, although this approach did not allow identifying unambiguously the dominant diagenetic carbon degradation pathway. During the rainy season, dilution led to significant decreases of salinity, TAlk and DIC in both mangrove creeks and adjacent main channels. In the Kieˆn Va`ng mangrove creeks a distinct increase of pCO2 and decrease of %O2 were observed. The increase of TSM suggested enhanced inputs of organic matter probably from land surrounding the mangrove creeks, that could have led to higher benthic and water column heterotrophy. However, the flushing of water enriched in dissolved CO2 originating from soil respiration and impoverished in O2 could also have explained to some extent the patterns observed during the rainy season. Seasonal variations of pCO2 were more pronounced in the Kieˆn Va`ng mangrove creeks than in the Tam Giang mangrove creeks. The airewater CO2 fluxes were 5 times higher during the rainy season than during the dry season in the Kieˆn Va`ng mangrove creeks. In the Tam Giang mangrove creeks, the airewater CO2 fluxes were similar during both seasons. The airewater CO2 fluxes ranged from 27.1 mmol C m 2 d 1 to 141.5 mmol C m 2 d 1 during the dry season, and from 81.3 mmol m 2 d 1 to 154.7 mmol m 2 d 1 during the rainy season. These values are within the range of values previously reported in other mangrove creeks and confirm that the emission of CO2 from waters surrounding mangrove forests are meaningful for the carbon budgets of mangrove forests. [less ▲]

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See detailDissolved primary production and heterotrophic prokaryote reassimilation in a large oligotrophic tropical lake (Lake Kivu, Eastern Africa)
Morana, Cédric; Sarmento, Hugo; Bouillon, Steven et al

Conference (2012, July 11)

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See detailDissonance cognitive en contexte postcolonial africain: contradictions dans les valeurs et normes juridiques de succession
Bomda, Joseph ULg; Vaidis, David

Conference (2012, July)

La communication fait suite à la doléance de Leon Festinger de voir les recherches psychosociologiques sur la dissonance cognitive sortir des laboratoires pour aller au contact du réel dans le monde réel ... [more ▼]

La communication fait suite à la doléance de Leon Festinger de voir les recherches psychosociologiques sur la dissonance cognitive sortir des laboratoires pour aller au contact du réel dans le monde réel. (Festinger, 1999). Le cas des conflits de normes successorales (tradition vs. modernité) en rapport avec la veuve et la jeune fille dans le contexte postcolonial camerounais est considéré. L’existence d’un processus de dissonance (vécu et gestion) différencié est postulée. Cependant, il diffère selon l’état matrimonial des parents et l’âge des victimes. Trois-cent-quatre-vingt-deux camerounaises victimes du conflit de normes successorales entre la tradition et la modernité ont rendu compte de leur vécu et de la gestion psychologiques de ce vécu. Un questionnaire d’affects et de stratégies de gestion auto-rapportés a été utilisé à cet effet. Les résultats confirment l’influence de l’état matrimonial des parents et de l’âge des enfants filles comme des facteurs étiologique et de vulnérabilité à la dissonance cognitive. [less ▲]

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See detailDissuasion française et Pesdc
Dumoulin, André ULg

in Sébastien Boussois, Christophe Wasinski (Ed.) Armement et désarmement nucléaires. Perspectives euro-atlantiques (2011)

Cette contribution à un ouvrage collectif reprenant les actes d'un colloque international intitulé "L'Alliance atlantique et l'Europe au défi de l'armement et du désarmement nucléaires" et organisé ... [more ▼]

Cette contribution à un ouvrage collectif reprenant les actes d'un colloque international intitulé "L'Alliance atlantique et l'Europe au défi de l'armement et du désarmement nucléaires" et organisé conjointement par l'ULB et l'Université de Montréal le 30 avril 2010. [less ▲]

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See detailLa dissuasion nucléaire du futur
Dumoulin, André ULg

in Défense et sécurité internationale hors série (2012), 23(23),

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See detailLa dissuasion nucléaire en mutation
Dumoulin, André ULg

Book published by GRIP (1996)

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See detailDissuasion nucléaire et Europe. Entre zones grises et zones floues
Dumoulin, André ULg

in Défense et sécurité internationale (2009)

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See detailLa dissuasion nucléaire française : paramètres doctrinaux, politiques et techniques. Révolution ou inflexion de la stratégie en post-guerre froide (1990-2006) ?
Dumoulin, André ULg

Report (2006)

Ce rapport édité par le Département de science économique de l'Ecole royale militaire (Bruxelles) analyse l'évolution de la stratégie nucléaire française entre 1990 et 2006 du point de vue doctrinal ... [more ▼]

Ce rapport édité par le Département de science économique de l'Ecole royale militaire (Bruxelles) analyse l'évolution de la stratégie nucléaire française entre 1990 et 2006 du point de vue doctrinal, politique et idéologique. [less ▲]

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See detailLa dissuasion. Histoire du nucléaire militaire français
Dumoulin, André ULg

in Histoire & Stratégie (2012), (10),

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See detailDistal ERBB2 promoter fragment displays specific transcriptional and nuclear binding activities in ERBB2 overexpressing breast cancer cells
Delacroix, Laurence ULg; Begon, Dominique ULg; Chatel, Guillaume et al

in DNA & Cell Biology (2005), 24(9), 582-594

Overexpression of the ERBB2 gene occurs in 30% of human breast cancers and is correlated with poor prognosis. The deregulation is the consequence of an increased transcription level and gene amplification ... [more ▼]

Overexpression of the ERBB2 gene occurs in 30% of human breast cancers and is correlated with poor prognosis. The deregulation is the consequence of an increased transcription level and gene amplification. Several laboratories, including our own, have identified, in the proximal promoter, enhancers implicated in the gene overexpression. However, our previous studies of a 6-kb ERBB2 promoter fragment revealed the presence of repressing fragments, which were able to overcome the effect of the proximal enhancers. These repressing elements were functional in all cell lines, regardless of their endogenous ERBB2 expression level. Here, we show that a distal ERBB2 promoter region restores high transcription rates specifically in ERBB2 overexpressing breast cancer cells. This distal promoter region thus contains enhancers essential for the overexpression of the gene. By EMSA, performed with nuclear extract of cells overexpressing (BT-474) or not (MDA-MB-231) the ERBB2 gene, we show that at least two sequences of the distal promoter region are bound exclusively by BT-474 extract. Further experiments reveal that AP-2 transcription factors contribute to this differential binding activity, by binding recognition sequences located 4500 bp and 4000 bp upstream of the transcription start site. These sites are occupied by AP2 in vivo, as demonstrated by ChIP assay. Inactivation of AP-2 proteins in ERBB2 overexpressing cells reduces the distal promoter activity up to 70%, indicating the AP-2 factors are implicated in the strong distal enhancing effect. Moreover, we identified a 54-bp fragment that is bound specifically by BT-474 nuclear extract. Further experiments did not lead to the identification of the protein responsible for this binding. Our results thus highlight the importance of ERBB2 distal promoter region and further implicate AP-2 in ERBB2 overexpression in breast cancer cells. [less ▲]

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See detailDistance and location processes in memory for time : An update
Bastin, Christine ULg; Friedman, William J.

Conference (2004)

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible ... [more ▼]

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible neurological basis of location-based processes. In an ERP study, adults performed tasks thought to bias subjects to use distance or location processes. Late frontal activity was specifically linked to location-based processes. In another study using the same tasks, aging was found to disrupt location-based processes more than distance-based processes. Age-related differences in the use of location-based processes were mediated by speed of processing and by working-memory capacities. [less ▲]

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See detailDistance and location processes in memory for time: An update
Bastin, Christine ULg; Friedman, William J.

in Proceedings of the 28th International Congress of Psychology (2005)

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible ... [more ▼]

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible neurological basis of location-based processes. In an ERP study, adults performed tasks thought to bias subjects to use distance or location processes. Late frontal activity was specifically linked to location-based processes. In another study using the same tasks, aging was found to disrupt location-based processes more than distance-based processes. Age-related differences in the use of location-based processes were mediated by speed of processing and by working-memory capacities. [less ▲]

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See detailDistance correlations and dynamics of liquid GeSe: An ab initio molecular dynamics study
Raty, Jean-Yves ULg; Godlevsky, V. V.; Gaspard, Jean-Pierre ULg et al

in Physical Review. B, Condensed Matter and Materials Physics (2001), 64

We analyze the structure and dynamics of semiconducting liquid GeSe using ab initio molecular-dynamics simulations. We show the local order of the liquid to be close to that of the low-temperature ... [more ▼]

We analyze the structure and dynamics of semiconducting liquid GeSe using ab initio molecular-dynamics simulations. We show the local order of the liquid to be close to that of the low-temperature crystalline phase. alpha -GeSe. In particular, we show that the Peierls distortion, which defines the a phase and vanishes in the high-temperature beta crystalline phase, reenters GeSe in the melt. Examining the distance histograms allows one to analyze the Ge environment as consisting of a Gese(3) unit and having one Ge-Ge defective bond. Evidence is presented that Peierls distortion is directly responsible for the semiconducting behavior of the melt. The calculated viscosity and electrical conductivity are in agreement with the experiment. An additional neutron-diffraction experiment indicates that this liquid structure is unmodified 200 K above the melting point. [less ▲]

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See detailDistance intertextuelle et classement des textes d'après leur structure : méthodes de découpage et analyses arborées
Longrée, Dominique ULg; Mellet, Sylvie; Luong, Xuan

in Viprey, Jean-Marie; Condé, Claude; Lelu, A. (Eds.) et al JADT 2006, 8èmes Journées internationales d’Analyse statistique des Données Textuelles (2006)

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