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See detailAssessment of the effects of tree species diversity on forest biodiversity and ecosystem functioning (FORBIO) - Final Report
Verheyen, Kris; Carnol, Monique ULg; Branquart, Etienne et al

Report (2010)

Forests are biodiversity hotspots worldwide with 70% of terrestrial biodiversity being included in forested landscapes. However, deforestation, forest degradation and fragmentation lead to an increasing ... [more ▼]

Forests are biodiversity hotspots worldwide with 70% of terrestrial biodiversity being included in forested landscapes. However, deforestation, forest degradation and fragmentation lead to an increasing rate of species extinctions. Hence, predicting the consequences of changes in species numbers, in distribution patterns of taxa, and of shifts in dominance, has become a major challenge for community and ecosystem ecology. However, until now the relationships between biodiversity and ecosystem functioning in forests have been largely underexplored Therefore, the overall aims of the BELSPO cluster project FORBIO are: to review, synthesize and disseminate existing knowledge about the benefits and drawbacks of mixed stands vs monocultures (WP1); and to establish a highly innovative, large-scaled forest biodiversity experiment to evaluate the impact of increasing tree diversity on forest ecosystem functioning (WP2). To achieve the first objective, a so-called ‘white paper’ has been compiled by the FORBIO team members which has been published in Dutch as a special issue of the BosRevue and in French as a special issue of Forêt Wallone. Among stakeholders, many different opinions exist about the functioning of mixed forests and therefore the scientific evidence was confronted with stakeholder perceptions on ecosystem services in mixed forests compared to monocultures. The principal outcome was that stakeholders appear to have quite strong opinions on the functioning of mixed vs monoculture stands, whereas the review of the scientific literature highlighted the lack of specific information on forest ecosystem services in mixed forests compared to monocultures, in particular from studies where confounding factors can be eliminated or accounted for. The second objective was met by establishing two large-scaled tree diversity experiments in Zedelgem (Flanders) and Gedinne (Wallonia). Based on a state-of-the-art experimental design, 32 810 and 33 304 trees of five different species were planted in 42 and 44 experimental plots in Zedelgem and Gedinne, respectively. A third experiment with a similar design will be established in Hecthel-Eksel (Flanders) in 2011. FORBIO’s short-term contributions to sustainable development are mainly related to the fact that the project has introduced the state-of-the-art concepts and empirical support on the various relationships between biodiversity and ecosystem functioning to a large audience of forest owners, managers, users and scientists in Belgium. In the long-run, FORBIO will significantly contribute to a better understanding of the importance of tree species diversity for the functioning of forest ecosystems and the ecosystem services that they provide thanks to the establishment of the two (and soon three) large-scaled tree diversity experiments. Furthermore, the experiments, embedded in the worldwide TreeDivNetwork, will most likely continue to act as an attractor for researchers from Belgium and abroad. [less ▲]

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See detailAssessment of the Electric and Magnetic field levels in the vicinity of the HV overhead power lines in Belgium.
Hoeffelman, Jean; Decat, Gilbert; Lilien, Jean-Louis ULg et al

in Conférence Internationale des Grands Réseaux Electriques à Haute Tension - CIGRE (2004, August)

Maximum exposure levels in the vicinity of HV power lines in Belgium.

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See detailAssessment of the entering stock, migration dynamics and fish pass fidelity of european eel in the belgian meuse river
Nzau Matondo, Billy ULg; Benitez, Jean-Philippe ULg; Dierckx, Arnaud ULg et al

in River Research & Applications (2016)

Migration dynamics of incoming eels in Belgium via Lixhe in the Meuse River were investigated using two fish passes with different configurations— net traps and automatic detection stations—as tools to ... [more ▼]

Migration dynamics of incoming eels in Belgium via Lixhe in the Meuse River were investigated using two fish passes with different configurations— net traps and automatic detection stations—as tools to distinguish resident and migrating eels. From April to September 2013, 435 eels (P50 length, 403 mm; range, 196–836 mm) were caught (daily maxima catch, 90 eels per day), 90% between 13 June and 1 August (50 days) and P50 on 19 July. Eels migrated mostly at 19–26 °C (P50, 24.4 °C), river discharge 65–314m3 s 1 (P50, 84m3 s 1), during the dark at 00:00–05:00 h and during both the waxing and waning phases of moonlight. From 396 eels tagged and released 0.3 km downstream of the Lixhe dam, 6.8% of them were recaptured, and 37.4% were detected. Migration flux was estimated at 7184 eels (0.863 t) using the markrecapture method and decreased to 1156 eels (0.139 t) using automatic transponder detection. Most eels probably migrated through a sluice located downstream of Lixhe to reach the upper Meuse via the Albert Canal. Eels moved almost independently to the configuration of the fish passes and their location, but most eels displayed fidelity to the fish pass where they were captured. Migrant eels showed a wide range of size and life stages, with a higher proportion of eels (80%) belonging to the yellow eel stage. A lower proportion of eels (6%) had a larger size and presented an advanced continental silvering process corresponding to the migrating stage before their transatlantic migration. Copyright © 2016 John Wiley & Sons, Ltd. [less ▲]

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See detailAssessment of the functional role of tree diversity: the multi-site FORBIO experiment
Verheyen, Kris; Ceunen, Kris; Ampoorter, Evy et al

in Plant Ecology and Evolution (2013), 146(1), 26-35

Context – During the last two decades, functional biodiversity research has provided strong support for the hypothesis that more biodiverse ecosystems have the potential to deliver more and better ... [more ▼]

Context – During the last two decades, functional biodiversity research has provided strong support for the hypothesis that more biodiverse ecosystems have the potential to deliver more and better services. However, most empirical support for this hypothesis comes from simple structured communities that are relatively easy to manipulate. The impact of forest biodiversity on forest ecosystem functioning has been far less studied. Experiment design – In this paper, we present the recently established, large-scale FORBIO experiment (FORest BIOdiversity and Ecosystem Functioning), specifically designed to test the effects of tree species diversity on forest ecosystem functioning. FORBIO’s design matches with that of the few other tree diversity experiments worldwide, but at the same time, the FORBIO experiment is unique as it consists of a similar experimental set-up at three sites in Belgium (Zedelgem, Hechtel-Eksel and Gedinne) with contrasting edaphic and climatological c haracteristics. This design will help to provide answers to one of the most interesting unresolved questions in functional biodiversity research, notably whether the effects of complementarity on ecosystem functioning decrease in less stressful and more productive environments. At each site, FORBIO consists of 41 to 44 plots (127 plots in total) planted with monocultures and mixtures up to four species, selected from a pool of five site-adapted, functionally different tree species. When allocating the treatments to the plots, we maximally avoided any possible covariation between environmental factors. Monitoring of ecosystem functioning already started at the Zedelgem and Gedinne sites and will start soon in Hechtel-Eksel. Multiple processes are being measured and as the trees grow older, we plan to add even more processes. Expected results – Not only basic science, but also forest management will benefit from the results coming from the FORBIO experiment, as FORBIO is, for instance, also a test case for uncommon, not well-known tree species mixtures. To conclude, FORBIO is an important ecosystem experiment that has the potential to deliver badly needed insights into the multiple relationships between biodiversity and ecosystem functioning, which will be valuable for both science and practice. [less ▲]

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See detailAssessment of the health status of wild fish inhabiting a cotton basin heavily impacted by pesticides in Benin (West Africa).
Agbohessi, Prudencio T.; Imorou Toko, Ibrahim; Ouedraogo, Alfred et al

in The Science of the total environment (2015), 506-507

To determine the impact of agricultural pesticides used in cotton cultivation on the health status of fish living in a Beninese cotton basin, we compared the reproductive and hepatic systems of fish ... [more ▼]

To determine the impact of agricultural pesticides used in cotton cultivation on the health status of fish living in a Beninese cotton basin, we compared the reproductive and hepatic systems of fish sampled from rivers located in both contaminated and pristine conditions. Different types of biomarkers, including biometric indices (a condition factor K, a gonadosomatic index GSI, and a hepatosomatic index HSI), plasma levels of sex steroids (11-ketotestosterone 11-KT, testosterone T and estradiol-17beta E2) and the histopathology of the gonads and liver, were investigated for two different trophic levels of the following two fish species: the Guinean tilapia Tilapia guineensis and the African catfish Clarias gariepinus. The fish were captured during both the rainy season (when there is heavy use of pesticides on cotton fields) and the dry season from one site, in Pendjari River (reference site), which is located outside the cotton-producing basin, and from three other sites on the Alibori River within the cotton-producing basin. Comparing fish that were sampled from contaminated (high levels of endosulfan, heptachlor and DDT and metabolites) and reference sites, the results clearly indicated that agricultural pesticides significantly decreased K and GSI while they increased HSI, regardless of the season, species and sex of the fish. These pesticides also induced a decrease in the plasma levels of 11-KT and T and increased those of E2. The histopathology of the testes revealed, in both species, a high rate of testicular oocytes, up to 50% in the African catfish, downstream of the Alibori River, which indicated estrogenic effects from the pesticides. The disruption of male spermatogenesis primarily included necrosis, fibrosis and the presence of foam cells in the lobular lumen. The histopathology of the ovaries revealed high levels of pre-ovulatory follicular atresia, impaired oogenesis, a decrease in the oocyte vitellogenic diameter and other lesions, such as fibrosis, vacuolation and melano-macrophagic centers. The histopathology of the liver revealed the presence of necrosis, hypertrophic hepatocytes, foci of vacuolation, glycogen depletion and hemosiderin. An assessment of the general health of the fish indicated that all of the sampled fish from the polluted sites were in poorer health compared with those from the reference site but that the African catfish appeared much more affected than the Guinean tilapia, regardless of the sex and season. In conclusion, the overall results indicated that agricultural pesticides significantly impair the endocrine regulation of fish living in the Beninese cotton basin and that this would most likely be one of the causes of the severe damage observed in the liver and gonads and the reduced health condition. [less ▲]

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See detailAssessment of the importance of the carbonate pump in surface waters of the Bay of Biscay
Harlay, Jérôme ULg; Chou, Lei; Dedonder, Virginie et al

Poster (2003, January 07)

Marine carbon research in the past decade has been mainly devoted to the understanding and quantification of processes controlling the fluxes of organic matter in the ocean. Little attention has been paid ... [more ▼]

Marine carbon research in the past decade has been mainly devoted to the understanding and quantification of processes controlling the fluxes of organic matter in the ocean. Little attention has been paid until now to the particulate inorganic carbon whose net fluxes to the sediments are comparable to those of the organic matter. There remains still a large uncertainty in the production and the fate of biogenic calcium carbonate in the oceanic carbon cycle. 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 coccolithophorid blooms occur frequently. The study focuses on processes associated with the oceanic production and dissolution of calcium carbonate, by combining field investigations, laboratory experiments and modelling efforts. The rate of primary production and of calcification by phytoplankton is evaluated by 14C incubation experiments during a coccolithophorid bloom-forming period in the area of investigation. The relative production of organic matter and calcium carbonate in the photic zone along a transect from the continental shelf across the slope to deep waters will be presented. A tentative mass balance of the carbon fluxes for this area will be constructed. These preliminary results confirm the importance that the calcium carbonate pump may play in open ocean. [less ▲]

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See detailAssessment of the Influence of Inflammation and FCGR3A Genotype on Infliximab Pharmacokinetics and Time to Relapse in Patients with Crohn's Disease.
Ternant, David; Berkane, Zahir; Picon, Laurence et al

in Clinical pharmacokinetics (2015)

BACKGROUND AND OBJECTIVES: Infliximab is a monoclonal anti-tumor necrosis factor-alpha (anti-TNFalpha) antibody that profoundly modified the treatment of Crohn's disease (CD). The polymorphism of Fc ... [more ▼]

BACKGROUND AND OBJECTIVES: Infliximab is a monoclonal anti-tumor necrosis factor-alpha (anti-TNFalpha) antibody that profoundly modified the treatment of Crohn's disease (CD). The polymorphism of Fc fragment of IgG, low affinity IIIa, receptor (CD16a) [FCGR3A] influences the biological response to infliximab in patients with CD. Our aim was to study its influence on infliximab pharmacokinetics and risk of relapse after infliximab discontinuation. METHODS: In 111 CD patients in remission, infliximab was discontinued and its concentrations were measured for 30 months or until relapse. Infliximab pharmacokinetics were described using monocompartmental population modeling. RESULTS: The elimination rate of infliximab increased with C-reactive protein (CRP) [p = 0.00018] and was 16 % higher in FCGR3A-158V/V patients than in F carriers (p = 0.0028). Risk of relapse was higher in patients with baseline CRP >/=5 mg/L than in those with a lower value (p = 0.0000029). In addition, there was a first-order interaction between CRP and the FCGR3A genotype; in patients with high CRP, risk of relapse was higher for V/V patients than for F carriers (hazard ratio 4.80 and 2.84 for V/V and F carriers, respectively; p = 0.013). CONCLUSION: Both increased inflammation and FCGR3A-158V/V genotype are associated with increased infliximab elimination and risk of relapse after infliximab discontinuation in patients with CD. [less ▲]

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See detailAssessment of the long term changes of the SES ecosystem
Grégoire, Marilaure ULg

Conference (2011, April)

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See detailAssessment of the long term changes of the SES ecosystem
Grégoire, Marilaure ULg

Conference (2009, November)

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See detailAssessment of the long-term effect of vaccination on transmission of infectious bovine rhinotracheitis virus in cattle herds hyperimmunized with glycoprotein E-deleted marker vaccine
Ampe; Duchateau, L.; Speybroeck, N. et al

in American Journal of Veterinary Research (2012), 73

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See detailAssessment of the NeQuick model at mid-latitudes using GNSS TEC and ionosonde data
Bidaine, Benoît ULg; Warnant, René

in Advances in Space Research (2010), 45(9), 1122-1128

The modelling of the Total Electron Content (TEC) plays an important role in global navigation satellite systems (GNSS) accuracy, especially for single-frequency receivers, the most common ones ... [more ▼]

The modelling of the Total Electron Content (TEC) plays an important role in global navigation satellite systems (GNSS) accuracy, especially for single-frequency receivers, the most common ones constituting the mass market. For the latter and in the framework of Galileo, the NeQuick model has been chosen for correcting the ionospheric error contribution and will be integrated into a global algorithm providing the users with daily updated information. In order to reach the ionosphere error correction level objective, the model itself as well as its use for Galileo are investigated. In our comparison process, we take advantage of various ionosphere data from several European stations (Dourbes in Belgium, El Arenosillo and Roquetes in Spain) where ionosonde and GPS TEC data are available for different solar activity levels. These data allow us to study NeQuick representation of the ionosphere at mid-latitudes. Constraining the model with ionosonde measurements, we investigate the difference between GPS-derived vertical TEC and corresponding values from NeQuick for a high solar activity level (year 2002). With this approach, we reach residual errors of less than 20% in standard deviation. We especially highlight the improvements from the latest (second) version of NeQuick and show the critical importance of the topside formulation. [less ▲]

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See detailAssessment of the NeQuick Model at Mid-latitudes using GPS TEC and Ionosonde Data
Bidaine, Benoît ULg; Warnant, René ULg

Conference (2007, July 11)

The ionosphere plays a crucial role in GNSS accuracy. In extreme cases, this electrically charged part of the atmosphere can lead to errors in positioning exceeding 100m. At first approximation, the ... [more ▼]

The ionosphere plays a crucial role in GNSS accuracy. In extreme cases, this electrically charged part of the atmosphere can lead to errors in positioning exceeding 100m. At first approximation, the ionospheric effect depends on the frequency of the incident signal and on the total content in free electrons of the ionosphere (“total electron content”, TEC) which is the integral of the electron density on the path between the satellite and the receiver. The modelling of this parameter reveals then itself to be critical in particular for single-frequency receivers, the most common ones constituting the mass market, but also for multiple-frequency devices which will comprise a fallback mode in single frequency within the framework of critical applications such as civil aviation where the level of precision must be guaranteed in all circumstances. The NeQuick model, which has been chosen for correcting the ionospheric error contribution in GALILEO single frequency users, calculates the electron density at a given point of the ionosphere according to the time conditions and the solar activity. This electron density can be integrated along the path from the receiver to the considered satellite to provide the TEC. The NeQuick model depends on a parameter Az (“effective ionization level”) which will be daily updated by the GALILEO ground stations to give the solar activity information to the model. In order to reach the ionosphere error correction level objective (70% or 20 TECu whichever is larger), the model itself as well as its use for GALILEO are investigated. Different situations have to be considered: different latitude regions (space conditions), different hours, seasons and years (time conditions) and specific phenomena appearance (magnetic storms, Travelling Ionospheric Disturbances – TIDs). In addition the results can be compared to different data sets among which GPS slant or vertical TEC measurements, Global Ionospheric Maps, ionosonde profiles, topside soundings but also other ionosphere models results such as IRI. As a first step in a thorough comparison process, we take benefit of various ionosphere data from the Dourbes Observatory (Belgium) where ionosonde and GPS TEC data are available on a period of more than one solar cycle, to study the mid-latitudes. We first investigate the difference between GPS-derived vTEC for Dourbes station and vTEC values from NeQuick for the latest years (between solar maximum in 2000 and minimum in 2006) in order to observe the temporal dependencies towards Universal Time, season and solar activity. The paper analyses the different situations when NeQuick fails to represent TEC in an adequate way to provide an efficient correction for navigation. Ionosonde measurements will help in the interpretation of these situations. [less ▲]

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See detailAssessment of the NeQuick Model at Mid-latitudes using GPS TEC and Ionosonde Data
Bidaine, Benoît ULg; Warnant, René ULg

in First Colloquium Scientific and Fundamental Aspects of the Galileo Programme (2007, October)

The ionosphere plays a crucial role in Global Navigation Satellite Systems (GNSS) accuracy. In extreme cases, this electrically charged part of the atmosphere can lead to errors in positioning exceeding ... [more ▼]

The ionosphere plays a crucial role in Global Navigation Satellite Systems (GNSS) accuracy. In extreme cases, this electrically charged part of the atmosphere can lead to errors in positioning exceeding 100 $m$. At first approximation, ionospheric effects depend mainly on the total content in free electrons of the ionosphere ("total electron content", TEC). The modelling of the latter parameter reveals thus itself critical in particular for single frequency receivers, the most common ones constituting the mass market. In the framework of GALILEO, the NeQuick model has been chosen to this extent and will be integrated into a global algorithm providing the users with daily updated information. In order to reach the specified correction level, the model itself and its latest evolutions as well as its use for GALILEO are investigated. As a first step in a thorough analysis, we take benefit of ionosonde and GPS TEC data from the Dourbes Geophysical Observatory (Belgium) to study the mid-latitudes. Constraining the model with ionosonde measurements, we first investigate the difference between GPS-derived vertical TEC (vTEC) for Dourbes station and corresponding values from NeQuick for the latest years for solar maximum in 2002 and minimum in 2006. With this approach, we reach residual errors of about 20% RMS for 2002 and 30% for 2006. Through a focusing process, we identify then gradually best and worst months and days for which we observe the evolution between two versions of NeQuick. We highlight among others improvements from the latest modification in the topside formulation which appears clearly in the electron density profiles examined at the end of the assessment. [less ▲]

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See detailAssessment of the new immunological test Hemoblot for detecting occult blood in faeces
Jeanson, Antoinette; Jamart, J.; Maisin, J. M. et al

in European Journal of Cancer Prevention (1994), 3(5), 407-412

Hemoblot, a new immunological faecal occult blood test, produced by Gamma, Angleur, Belgium, was characterized and compared with another immunological test (HemeSelect, SmithKline Diagnostics, USA) and ... [more ▼]

Hemoblot, a new immunological faecal occult blood test, produced by Gamma, Angleur, Belgium, was characterized and compared with another immunological test (HemeSelect, SmithKline Diagnostics, USA) and with a guaiac test (Hemoccult II, SmithKline Diagnostics). The analytical sensitivity of Hemoblot is 0.15 mg haemoglobin/g faeces and the test is specific for human haemoglobin. In addition, 135 symptomatic patients who had to undergo a colonoscopy were tested using the three tests. Two criteria were considered for the analysis: (1) the blood criterion: any pathology likely to cause colorectal or other bleeding; and (2) the precancerous-cancerous criterion: the pathology being either a colorectal polyp > 0.5 cm or a colorectal cancer. Considering both criteria, the sensitivity of Hemoblot was significantly higher than the sensitivity of Hemoccult: 38% and 23%, respectively, for the blood criterion; and 54% and 29% for the precancerous-cancerous criterion. Sensitivity and specificity did not differ statistically between Hemoblot and HemeSelect but Hemoblot was faster and simpler to perform. It could be widely used in mass screening. [less ▲]

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See detailAssessment of the night weather parameters and their use in forecasting model of leaf rust.
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

Conference (2010, August 07)

Detailed reference viewed: 11 (0 ULg)