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See detailAnnual activity cycle of adult brown trout (Salmo trutta L.): A radio-telemetry study in a small stream of the Belgian Ardenne
Ovidio, Michaël ULg

in Bulletin Français de la Pêche et de la Pisciculture (1999), (352), 1-18

During a study period of 26 months, twenty trout (26.0-57.0 cm FL; 198-1,685 g) were daily located from 16 to 466 days in a small stream of the Belgian Ardenne, the Aisne stream (tributary of the river ... [more ▼]

During a study period of 26 months, twenty trout (26.0-57.0 cm FL; 198-1,685 g) were daily located from 16 to 466 days in a small stream of the Belgian Ardenne, the Aisne stream (tributary of the river Ourthe) in order to characterize their annual pattern of mobility. Daily movements were more frequent and longer during the spawning period (October-December) than at any other time of the year. Upstream migrations (max.: 25 km) generally occurred during October and the first fortnight of November and were triggered by a combination of Variations of water temperature and water level within a thermal range of 10-14 degrees C. Spawning activity (second fortnight of November until late December) took place in the Aisne stream (max. width : 10 m) or in its small tributaries. Trout surviving spawning undertook a fast (max.:9,200 m in 24 h) and precise post reproductive homing. From winter to summer, daily movements were shorter and mainly corresponded to changes of residences within a home range of which the size was proportional to the trout's size. In March and June, some trout made long upstream unidirectional migrations of which the biological signification is still unknown. These results are discussed within the context of life history strategies and management of trout populations. [less ▲]

Detailed reference viewed: 198 (23 ULg)
Peer Reviewed
See detailAnnual congress of the international league for competition law.
Petit, Nicolas ULg

Conference (2009, October 25)

Detailed reference viewed: 7 (1 ULg)
See detailAnnual dynamics of pCO2 within bulk sea ice and related CO2 fluxes at Cape Evans (Antarctica)
Van Der Linden, Fanny ULg; Champenois, Willy ULg; Heinesch, Bernard ULg et al

Poster (2016, February 12)

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice ... [more ▼]

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice-Atmosphere Exchanges), annual dynamics of sea ice pCO2 was compared with CO2 fluxes measured by automated accumulation chambers at Cape Evans (Ross Island, Antarctica). Results confirmed a general trend of brine pCO2 supersaturation with respect to the atmosphere during the late winter (concentration of dissolved inorganic carbon - DIC - in brine and brine expulsion in the brine skim) leading to CO2 degassing, and undersaturation during the spring (carbon-uptake by autotrophs and brine dilution) leading to atmospheric CO2 uptake. Despite high primary production at the bottom of the ice in spring, DIC profiles suggest that sea ice as a whole appears to be net heterotrophic. Still, sea ice absorbs CO2 from the atmosphere, as a result of physical processes. Some variability in the CO2 fluxes (both in magnitude and sign) could not be explained by variability in sea ice pCO2 but rather seemed driven by variability in atmospheric conditions and sea ice surface properties. For instance, in late spring, CO2 fluxes showed a diurnal variability (from CO2 degassing to uptake) related to atmospheric temperature variations. Large and episodic CO2 fluxes were systematically positively correlated with strong wind events, and large CO2 degassing was observed over thin, wet and salty snow cover. [less ▲]

Detailed reference viewed: 49 (14 ULg)
See detailAnnual dynamics of pCO2 within bulk sea ice and related CO2 fluxes at Cape Evans (Antarctica)
Van Der Linden, Fanny ULg; Champenois, Willy ULg; Heinesch, Bernard ULg et al

Poster (2016, February 26)

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice ... [more ▼]

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice-Atmosphere Exchanges), annual dynamics of sea ice pCO2 was compared with CO2 fluxes measured by automated accumulation chambers at Cape Evans (Ross Island, Antarctica). Results confirmed a general trend of brine pCO2 supersaturation with respect to the atmosphere during the late winter (concentration of dissolved inorganic carbon - DIC - in brine and brine expulsion in the brine skim) leading to CO2 degassing, and undersaturation during the spring (carbon-uptake by autotrophs and brine dilution) leading to atmospheric CO2 uptake. Despite high primary production at the bottom of the ice in spring, DIC profiles suggest that sea ice as a whole appears to be net heterotrophic. Still, sea ice absorbs CO2 from the atmosphere, as a result of physical processes. Some variability in the CO2 fluxes (both in magnitude and sign) could not be explained by variability in sea ice pCO2 but rather seemed driven by variability in atmospheric conditions and sea ice surface properties. For instance, in late spring, CO2 fluxes showed a diurnal variability (from CO2 degassing to uptake) related to atmospheric temperature variations. Large and episodic CO2 fluxes were systematically positively correlated with strong wind events, and large CO2 degassing was observed over thin, wet and salty snow cover. [less ▲]

Detailed reference viewed: 42 (3 ULg)
See detailAnnual Efficiency of Separated Systems for Heating and Domestic Hot Water Needs in dwellings
Hauglustaine, Jean-Marie ULg

Conference (1982, March)

Any designer (architect, consulting engineer...), who must choose the technical solution of a heating installation in a house, is always confronted with the same alternatives: combined production of both ... [more ▼]

Any designer (architect, consulting engineer...), who must choose the technical solution of a heating installation in a house, is always confronted with the same alternatives: combined production of both hot water for heating needs and domestic hot water, assured by a combined boiler or a boiler producing only heating hot water and a separate water heater (instantaneous or with storage) for domestic hot water needs. The objective of this present study is to give the designer simple graphs which become an easy way to assume, with a good accuracy, the “global annual efficiency” of each solution, and allow a sensitivity study of efficiency to main parameters of each system. [less ▲]

Detailed reference viewed: 41 (2 ULg)
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See detailAnnual Greenland accumulation rates (2009–2012) from airborne snow radar
Koenig, L.; Ivanoff, A.; Alexander, P. et al

in Cryosphere (The) (2016), 10

Contemporary climate warming over the Arctic is accelerating mass loss from the Greenland Ice Sheet through increasing surface melt, emphasizing the need to closely monitor its surface mass balance in ... [more ▼]

Contemporary climate warming over the Arctic is accelerating mass loss from the Greenland Ice Sheet through increasing surface melt, emphasizing the need to closely monitor its surface mass balance in order to improve sea-level rise predictions. Snow accumulation is the largest component of the ice sheet's surface mass balance, but in situ observations thereof are inherently sparse and models are difficult to evaluate at large scales. Here, we quantify recent Greenland accumulation rates using ultra-wideband (2–6.5 GHz) airborne snow radar data collected as part of NASA's Operation IceBridge between 2009 and 2012. We use a semiautomated method to trace the observed radiostratigraphy and then derive annual net accumulation rates for 2009–2012. The uncertainty in these radar-derived accumulation rates is on average 14 %. A comparison of the radar-derived accumulation rates and contemporaneous ice cores shows that snow radar captures both the annual and long-term mean accumulation rate accurately. A comparison with outputs from a regional climate model (MAR) shows that this model matches radar-derived accumulation rates in the ice sheet interior but produces higher values over southeastern Greenland. Our results demonstrate that snow radar can efficiently and accurately map patterns of snow accumulation across an ice sheet and that it is valuable for evaluating the accuracy of surface mass balance models. [less ▲]

Detailed reference viewed: 29 (0 ULg)
Peer Reviewed
See detailAnnual meeting of the SBN/BVN
BOUQUEGNEAU, Antoine ULg; DELANAYE, Pierre ULg; CAVALIER, Etienne ULg et al

Conference (2013)

Detailed reference viewed: 5 (2 ULg)
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See detailAnnual net ecosystem carbon exchange by a sugar beet crop
Moureaux, Christine ULg; Debacq, Alain ULg; Bodson, Bernard ULg et al

in Agricultural and Forest Meteorology (2006), 139(1-2), 25-39

Detailed reference viewed: 37 (12 ULg)
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See detailAnnual nitrogen budget of the seagrass Posidonia oceanica as determined by in situ uptake experiments
Lepoint, Gilles ULg; Millet, S.; Dauby, Patrick ULg et al

in Marine Ecology. Progress Series (2002), 237

The uptake of nitrate and ammonium by the roots and leaves of Posidonia oceanica were determined between February 1993 and June 1999 by in situ experiments using the isotope 15 of nitrogen (N-15) as a ... [more ▼]

The uptake of nitrate and ammonium by the roots and leaves of Posidonia oceanica were determined between February 1993 and June 1999 by in situ experiments using the isotope 15 of nitrogen (N-15) as a tracer in a nutrient-poor coastal zone of the NW Mediterranean Sea (Revellata Bay, Corsica). Nitrate and ammonium leaf uptakes are recorded at 0.05 and 0.1 muM respectively. The high variability observed cannot be explained solely by the variation of the substrate concentrations in the water column. For leaves, mean specific uptake rates were 43 +/- 45 and 43 +/- 64 mug N g N-1 h(-1). Nitrate and ammonium leaf uptake fluxes (g N m(-2) yr(-1)) seem to have the same importance on an annual basis. :Nitrate uptake occurs mainly in winter and early spring, when nitrate concentrations in the water column are highest. The uptake of N, and mainly of ammonium, is significant throughout the year with maxima at the beginning of spring, but it is insufficient to meet the annual N requirement of the plant. Posidonia root biomass was very high and corresponded to high specific N uptake rates by the roots. Ammonium was incorporated by the roots 6 times faster than nitrate. In the sediment, this uptake capacity is limited by the nutrient diffusion rate, and the root uptake is therefore insufficient to meet the N requirements of the plant. In fact, P. oceanica of Revellata Bay have a complex N budget involving uptake and recycling processes and allowing the plants to meet their N requirements in one of the most nutrient-poor areas of the NW Mediterranean Sea. We calculated that leaf and root would contribute to 40 and 60% of the annual N uptake, respectively, and 60% of the annual N requirement of the plant. [less ▲]

Detailed reference viewed: 162 (19 ULg)
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See detailAnnual report 2009 of the IGCP-580 Project.
Da Silva, Anne-Christine ULg; Whalen, Michael; Hladil, Jindrich et al

Report (2009)

Detailed reference viewed: 2 (0 ULg)
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See detailAnnual report 2010 of the IGCP-580 Project.
Da Silva, Anne-Christine ULg; Whalen, Michael; Hladil, Jindrich et al

Report (2010)

Detailed reference viewed: 5 (0 ULg)
See detailANNUAL SCIENTIFIC REPORT - Climate change and Antarctic microbial biodiversity (CCAMBIO)
Tytgat, Bjorn; Willems, Anne; Sweetlove, Maxime et al

Report (2015)

Detailed reference viewed: 40 (12 ULg)
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See detailANNUAL SCIENTIFIC REPORT PHASE II "Impact of Phenology and Environmental Conditions on BVOC Emissions from Forest Ecosystems" "IMPECVOC"
Dewulf, Jo; Joó, Eva; Steppe, Kathy et al

Report (2009)

Detailed reference viewed: 10 (5 ULg)