References of "1997"
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See detailIPM in Asia - A review of existing projects in the Philippines and Indonesia
Wynn, Nigel R.; Schiffers, Bruno ULg; Seghers, N. et al

in Agro-Chemicals News in Brief (1997), XX(2), 1-18

Integrated Pest Management means a pest management system that, in the context of the associated environment and the population dynamics of the pest species, utilizes ail suitable techniques and methods ... [more ▼]

Integrated Pest Management means a pest management system that, in the context of the associated environment and the population dynamics of the pest species, utilizes ail suitable techniques and methods in as compatible a manner as possible and maintains the pest populations at levels below those causing economically unacceptable damage or 1055. FAO-Code- of Conduct 1984. [less ▲]

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See detailLe transport intermodal en Belgique
Jacob, Damien ULg

in Le rail et la route : le commerce ou la dispute (1997)

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See detailThe use of a food frequency questionnaire in a adolescent population
Paulus, D.; Saint-Remy, Annie ULg; Jeanjean, Michel et al

in Gaceta Sanitaria (1997, November), 11(suppl 2), 37

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See detailWhole-body 18FDG positron emission tomography in the staging of non-small cell lung cancer.
Bury, Thierry ULg; Dowlati, A.; Paulus, Patrick et al

in European Respiratory Journal (1997), 10(11), 2529-34

Despite advances in morphological imaging, some patients with lung cancer are found to have nonresectable disease at surgery or die of recurrence within yr of surgery. We performed a prospective study in ... [more ▼]

Despite advances in morphological imaging, some patients with lung cancer are found to have nonresectable disease at surgery or die of recurrence within yr of surgery. We performed a prospective study in 109 patients to compare the accuracy of whole-body positron emission tomography (PET) using fluorine-18 deoxyglucose (18FDG) and conventional imaging (CI) methods for the staging of non-small cell lung cancer (NSCLC). When CI or PET study suggested metastatic disease, confirmation was obtained by biopsy or follow-up information. As compared to CI, 18FDG-PET correctly changed the N stage in 22 patients (33%) and the M stage in 15 patients (14%). For the detection of distant metastases, PET study showed five false-positive sites and no false-negative cases. Currently, the accuracy of PET in the detection of M stage is 96%. Our study shows that visual interpretation of whole-body fluorine-18 deoxyglucose-positron emission tomography images can improve the diagnostic accuracy in the staging of non-small cell lung cancer. Further experience is needed to establish if metabolic imaging would be a cost-effective tool in the future management of lung cancer. [less ▲]

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See detailA Computer Aided Design of a Secure Registration Protocol
Germeau, François; Leduc, Guy ULg

in Formal Description Techniques and Protocol Specification, Testing and Verification (1997, November)

We use the formal language LOTOS to specify a registration protocol between a user and a Trusted Third Party, that requires mutual authentication. We explain how a model-based verification method can be ... [more ▼]

We use the formal language LOTOS to specify a registration protocol between a user and a Trusted Third Party, that requires mutual authentication. We explain how a model-based verification method can be used to verify its robustness to attacks by an intruder. This method is also used to find a simpler protocol that remains secure. [less ▲]

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See detailPort-Soudan, le roman d’un soixante-huitard. Entretien avec Olivier Rolin
Willson, Patricia ULg

in Revue de la SAPFESU (1997), (15), 28-33

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See detailUne méthode naturelle de traitement des potentiels flottants associée à la méthode des éléments finis
Dular, Patrick ULg; Henrotte, François; Meys, Benoît et al

in Journal de physique. III (1997), 7(11), 2201-2209

Une méthode efficace de traitement des potentiels flottants, utilisée dans le cadre de la méthode des éléments finis et appliquée au problème de l'électrostatique, est présentée. De plus, cette méthode ... [more ▼]

Une méthode efficace de traitement des potentiels flottants, utilisée dans le cadre de la méthode des éléments finis et appliquée au problème de l'électrostatique, est présentée. De plus, cette méthode conduit à une technique pour l'évaluation de la charge électrique, technique qui se base sur un calcul moyenné en accord parfait avec la formulation faible discrétisée du problème. La méthode générale offre alors l'avantage de donner directement accès, lors du calcul, aux charges électriques totales des conducteurs à potentiels fixés ou flottants, tout en préservant le caractère symétrique de la matrice du système, ce qui permet un couplage aisé entre charges et potentiels tant au niveau de la formulation qu'au niveau de la résolution. Elle permet ainsi d'aborder tout problème électrostatique sans aucune technique intermédiaire de calcul, par exemple de différentiation. [less ▲]

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See detailNew polybutadiene-based thermoplastic elastomers: synthesis, morphology and mechanical properties
Dubois, Philippe ULg; Yu, Yisong; Teyssié, Philippe et al

in Rubber Chemistry & Technology (1997), 70(5), 714-726

Well defined poly[styrene-b-butadiene-b-styrene] block copolymers (SBS) end-capped with poly(t-butyl methacrylate) (PtBMA) and poly(methacrylic acid) (PMA) outer blocks, respectively, have been ... [more ▼]

Well defined poly[styrene-b-butadiene-b-styrene] block copolymers (SBS) end-capped with poly(t-butyl methacrylate) (PtBMA) and poly(methacrylic acid) (PMA) outer blocks, respectively, have been synthesized by the sequential anionic polymerization of butadiene, styrene and tBMA, followed by the selective hydrolysis of the PtBMA blocks into the corresponding PMA blocks. The structure-property relationships of these new thermoplastic elastomers have been investigated, with a special emphasis on the effect of the ester or acid outer blocks on the bulk properties. As a rule, tensile strength is improved by increasing the length of the ester or acid outer blocks from 0 to 140 methacrylic units. Dipole-dipole intermolecular interaction of the PtBMA blocks and hydrogen bonding of the PMA blocks may account for enhanced mechanical properties. However, too high a degree of strong intermolecular interactions can constitute a deterrent to good phase separation. This is supported by morphological observations and loss in tensile properties when the relative content of the ester or acid outer blocks exceeds some critical value. In the case of a high acid content, DSC analysis shows two thermal transitions at -70 ??C and 230 ??C for PBD and PMA blocks, respectively. [less ▲]

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See detailDifunctional initiator based on 1,3-diisopropenylbenzene. 7. Mechanical and thermal properties of new butadiene-based thermoplastic elastomers
Yu, Yisong; Dubois, Philippe ULg; Jérôme, Robert ULg et al

in Rubber Chemistry and Technology (1997), 70(5), 820-838

Mechanical and thermal properties of SBS thermoplastic elastomers, in which S stands for polystyrene and B for polybutadiene, can be remarkably improved through end-capping by syndiotactic poly(methyl ... [more ▼]

Mechanical and thermal properties of SBS thermoplastic elastomers, in which S stands for polystyrene and B for polybutadiene, can be remarkably improved through end-capping by syndiotactic poly(methyl methacrylate) sequences. Furthermore, the upper service temperature of these sPMMA teleblock copolymers can also be enhanced by blending with isotactic PMMA so that the rubbery PBD soft segments are connected to high-melting stereocomplexed hard segments. The factors which affect the mechanical and thermal properties of these novel thermoplastic elastomers have been extensively investigated. [less ▲]

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See detailLipopeptides alter Bacillus subtilis hydrophobicity by adsorbing onto cell surfaces
Ahimou, François; Razafindralambo, Hary ULg; Paquot, Michel ULg

Poster (1997, October 29)

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See detailNitrogen deposition and nitrification in coniferous forests’
Carnol, Monique ULg

Doctoral thesis (1997)

The increased inorganic nitrogen (N) deposition in the last decades has become a major concern for the health of forest ecosystems. High anthropogenic N emissions, mainly from fossil fuel combustion and ... [more ▼]

The increased inorganic nitrogen (N) deposition in the last decades has become a major concern for the health of forest ecosystems. High anthropogenic N emissions, mainly from fossil fuel combustion and livestock agriculture, have resulted in both high gaseous concentrations and high deposition in rainfall and throughfall. In forest ecosystem, where N is no longer limiting to primary production due to high inputs, the excess N is thought to be related to forest decline and a concept of ‘N saturation ‘ has been developed. In particular, N in the form of NH4, in excess to plant and microbial demands could lead to soil acidification if nitrified in the soil and leached, causing loss of base cations or mobilisation of phytotoxic aluminium. Nutrient imbalances due to high soil solution NH4/cation ratios or damaged root systems may also occur. The fate of the incoming NH4 is central to determining the effects on the ecosystem, and is closely related to the controls of nitrification. Although this process has been intensely studied in pure cultures for some nitrifying bacteria, the organisms responsible and controlling factors in acid forest soils are still poorly understood. A better comprehension of the fate of NH4 deposition is necessary to determine ‘Critical Loads for N’, the threshold deposition not damaging to the ecosystem, which is used as a political tool for quantifying pollution limits. In this thesis, I focused on a) the effects of increased (NH4)2SO4 deposition on soil solution chemistry of six coniferous forest sites the presence of live roots, b) the impacts of (NH4)2SO4 deposition on Norway spruce (Picea abies [L.] Karst) and Scots pine (Pinus sylvestris L.) fine roots, and c) the controls of nitrification in an acid forest soil. The work was part of the CEC project ‘CORE’, investigating the effects of atmospheric pollution on nutrient turnover in soils. An identical field experiment was performed in six coniferous sites, situated in five European countries. Chronically increased NH4 deposition by 75 kg N ha-1 a-1 through (NH4)2SO4 application, demonstrated the contrasting responses of the different ecosystems. Soil solution concentrations and yearly ionic fluxes were analysed. (NH4)2SO4 treatment resulted in deposition of 79 to 93 kg N ha-1 a-1 at the different sites. In the two less acidic, clay/clay loam soils, only 6% of the added NH4 was lost through leaching. The two sandy soils lost up to 75% of the added NH4, and the two remaining sites lost ca. 25%. Leaching of added NH4 was thought to be related to soil physico-chemical characteristics, such as pH, C and N content and texture. NO3 leaching was increased at three sites, only 4-9 months after starting the (NH4)2SO4 treatment, with a maximum doubling of concentrations. One sandy soil failed to nitrify under any condition, and the other sandy soil showed high NO3 leaching under all treatments, but no increase due to increased N inputs. The presence of live roots reduced NO3 leaching in two sites, delaying the increase in soil solution NO3 concentrations in response to the (NH4)2SO4 deposition in one of them. In all nitrifying soils, soil solution NO3 concentrations were related to cation concentrations, with Al being the dominant cation in the more acid soils with low base saturation. This experiment demonstrated the importance of soil N storage capacity and nitrification potential in determining the consequences of increased NH4 deposition, and the strong relationship between NO3 and cation leaching. Ionic fluxes and soil solution chemistry were further analysed in one of the six sites (Grizedale, UK). In this Norway spruce stand on clay soil, NO3 fluxes were increased by increased (NH4)2SO4 deposition, and mainly balanced by increased Al losses. This soil had a pHH2O around 3.6, and was characterised by over 90% of the exchange complex being occupied by Al. Independent of treatment, soil solution changed from Ca to Al leaching during the 18 month field experiment, with a decrease in soil solution pH from 4.9 to 3.8. At the end of the experiment, soil solution Al concentrations were higher for the (NH4)2SO4 treatments. It was suggested that nitrification had caused the pH decrease, with a further lowering of the base saturation, linked to a abrupt increase in soil solution Al concentrations. The impacts of increased (NH4)2SO4 deposition and soil characteristics on Norway spruce root biomass and vitality, and on Norway spruce and Scots pine fine root chemistry, were investigated with an ingrowth core technique. The same experiment was performed in a Norway spruce stand on clay soil (Grizedale, UK) and a Scots pine stand on sandy soil (Wekerom, NL), using soil from each of the two sites. For Norway spruce, root biomass and numbers of fine root tips were higher in the organic than in the mineral horizon of the clay and sandy soils. This was related to higher fine root Al and lower Ca contents in the mineral horizon. Root biomass and the proportion of dead roots were higher in the clay soil, compared to the sandy soil, with higher root Al contents, despite lower soil solution Al concentrations than in the sandy soil. For Norway spruce, a negative correlation between root biomass and fine root Al content was established. Enhanced N deposition caused an increase in the total number of root tips and in the proportion of dead roots in the sandy soil. Effects of increased (NH4)2SO4 deposition on root biomass were not significant for the clay soil, yet caused increased fine root N content in the organic horizon for both species. Scots pine fine roots also showed higher Al and lower Ca contents in the mineral horizon. (NH4)2SO4 treatment caused increased fine root Al content and a decreased Mg/Al ratio in the mineral layer of the sandy soil, with opposite effects in the clay soil. This (NH4)2SO4 treatment effect in the sandy soil for Scots pine was the only indication of a potential adverse effect of (NH4)2SO4 deposition on fine roots. Results demonstrated the dominant importance of inherent soil characteristics and the stratification into soil horizons on fine root growth and chemical composition. The effects of temperature, throughfall volume and NH4 deposition on soil solution NO3 concentrations, N2O emissions and numbers of NH4 oxidisers were investigated for the Grizedale soil in a controlled laboratory experiment. Multiple regression and surface response analysis revealed temperature as the most important factor, with an optimum for NO3 leaching and numbers of NH4 oxidisers in the mineral horizon at 11°C. Volume acted independently of temperature with a minimum at 870 mm throughfall 2 weeks-1. The relatively low optimum temperature compared to other studies was explained by the minimum disturbance of the soil in the current study. NO3 fluxes increased quadratically with throughfall volume. N2O fluxes increased quadratically with temperature and throughfall volume, and showed high variability. It was suggested that the temperature optimum for net nitrification depended on the physico-chemical characteristics of the soil and on the activity of decomposers, by competition for O2 and NH4. Optimum temperatures may have been overestimated in previous studies using disturbed soils. The regression model for NO3 leaching derived from the laboratory experiment was applied to data from the previous field experiment and tested with different time intervals for temperature input parameters. A model including two-monthly mean temperatures yielded the best fit between measured and simulated values, as determined by correlation and minimum sum of squared residuals. Simulated NO3 leaching was over-estimated in the second part of the field study. The good correspondence between field temperature frequency distribution and the optimum temperature determined by the regression model, as well as the high correlation between measured and simulated values, demonstrated the adequacy of a quadratic model with a relatively low temperature optimum to describe field NO3 leaching, determined for the same soil with an identical sampling design. [less ▲]

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See detailOptimisation et Scale up des Fermentations de Production de Starters Lactiques.
Hamdi, M.; Hamza, S.; Amor, L. et al

Poster (1997, October 27)

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See detailLes applications des bactéries lactiques
Thonart, Philippe ULg

Conference (1997, October 27)

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See detailIdentification de la flore lactique du lait fermenté traditionnel tunisien (lben) et évaluation des composés aromatisants
Ben Amor, K.; Cornelius, C.; Mahjoub, A. et al

Poster (1997, October 27)

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See detailA comparison of two methods for pulmonary function testing in horses with upper and lower airway obstruction
Van Erck, Emmanuelle; Duvivier, D. H.; Art, Tatiana ULg et al

Poster (1997, October 24)

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See detailX ray in RDS with HFOV and surfactant: what has changed ?
Rausin, L; Khamis, J; Bertand, JM et al

Conference (1997, October 24)

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See detailspontaneous pneumothorax treated by HFOV (abstract 42)
Petermans, MF; Battisti, Oreste ULg; François, A. et al

Conference (1997, October 24)

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See detailA two year experience with primary high frequency ventilation in neonatal respiratory distress syndrome (abstract 14)
Detaille, T; Battisti, Oreste ULg; François, A. et al

Conference (1997, October 24)

Detailed reference viewed: 32 (6 ULg)