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See detailThe effect of size, weight, body compartment, sex and reproductive status on the bioaccumulation of 19 trace elements in rope-grown Mytilus galloprovincialis
Richir, Jonathan ULg; Gobert, Sylvie ULg

in Ecological Indicators (2014), 36

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the ... [more ▼]

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the use of bioindicator species, such as the Mediterranean mussel Mytilus galloprovincialis (Lamarck, 1819). That species has been widely used to monitor the chemical pollution of coastal ecosystems by Cr, Ni, Cu, Zn, Cd, Pb, As, Ag and V. Conversely, environmental levels of Be, Al, Fe, Mn, Co, Se, Mo, Sn, Sb and Bi have been little or not monitored so far in mussel watch programs. Bioaccumulation processes of these 19 TEs in rope-grown M. galloprovincialis purchased from a salt pond with good chemical water quality were thus investigated in the present study. Mussels efficiently accumulated the 19 studied TEs. Bioaccumulation processes were driven by numerous mutually dependent biological parameters such as the mussel size and flesh weight, the sex and the reproductive status and the body compartment considered. TE bioaccumulation was a power function of the mussel soft body dry weight; total contents linearly increased with the shell length. Small-size mussels overall concentrated more TEs, with a high inter-individual variability, consequently influencing the modelling of their bioaccumulation in the whole rope population. Although a large range of rope-grown M. galloprovincialis sizes can be used for monitoring purposes, one will thus take care not to use extreme size individuals. The influence of gametogenesis in determining female body higher TE concentrations prior to spawning could not be neglected and varied depending on the element. TEs were preferentially accumulated in the hepatopancreas, except for Zn, Se, Cd and Mo, more concentrated in gills. Gametogenesis did not influence TE distribution between body compartments, but likely diluted their concentrations as a direct consequence of massive reproductive tissue production. So, results from the present study underline the potential use of M. galloprovincialis in the biomonitoring of numerous little studied TEs and give some insights into the decisive role played by some relevant biological parameters in bioaccumulation processes of the 19 investigated TEs in rope-grown mussels. [less ▲]

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See detailEffect of SK channel blockade on the firing of dorsal raphe neurons in anaesthetized rats
Alleva, Livia ULg; Rouchet, Nathalie; Waroux, Olivier ULg et al

Poster (2006, October 17)

K channels are small conductance calcium-activated potassium channels which trigger an outward current generating an afterhyperpolarization (AHP). This AHP follows a single or a train of action potential ... [more ▼]

K channels are small conductance calcium-activated potassium channels which trigger an outward current generating an afterhyperpolarization (AHP). This AHP follows a single or a train of action potential, and therefore is important in the regulation of the firing frequency and/or pattern of many types of neurons. Serotonergic (5-HT) neurons from the raphe nuclei express SK channels and exhibit a significant AHP which can be efficiently blocked in vitro by apamin and N-methyl laudanosine (NML) (Scuvée-Moreau et al, 2004). In the later study, we found that some but not all neurons (50%) had a significantly increase in their firing rate when positive current was injected after SK channel blockade. In order to determine the physiological relevance of these channels in vivo, single unit extracellular recordings were carried out in anesthetized rats and combined with iontophoresis of the specific non-peptidic SK channel blocker, UCL1684. 5-HT neurons were tested for their inhibitory response to locally applied 5-HT and histological analysis confirmed the localization of the recording site. UCL 1684 was used at a concentration of 200 µM. Out of 11 neurons recorded, 6 showed a significant increase in the production of doublets, with no effect on their mean firing rate as compared to the control condition. The other neurons were completely unaffected. These results suggest that the responsiveness of presumed 5-HT neurons to SK channel block is variable. Although the use of 200 µM UCL allow us to be sure of a sufficient SK blockade at the recording site (Waroux et al, 2005), we can not rule out the possibility that SK channels present at the dendritic level were not completely blocked. In conclusion, SK channels in vivo might play a role in controlling the firing pattern of a subgroup of 5-HT neurons. [less ▲]

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See detailThe effect of social security on saving: the case of Belgium with a particular emphasis on the behaviour of the aged
Pestieau, Pierre ULg; Perelman, Sergio ULg

in Empirical Economics (1984), (9), 15-26

Based on a consumer expenditure function estimated with Belgian time series data, this paper analyses the impact of social security on personal saving. It shows that social security has a depressive ... [more ▼]

Based on a consumer expenditure function estimated with Belgian time series data, this paper analyses the impact of social security on personal saving. It shows that social security has a depressive effect, mainly by affecting the saving behavior of the aged. [less ▲]

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See detailThe Effect of Sodium Monofluorophosphate Plus Calcium on Vertebral Fracture Rate in Postmenopausal Women with Moderate Osteoporosis. A Randomized, Controlled Trial
Reginster, Jean-Yves ULg; Meurmans, L.; Zegels, Brigitte ULg et al

in Annals of Internal Medicine (1998), 129(1), 1-8

BACKGROUND: Fluoride is effective in increasing trabecular bone mineral density (BMD) in the spine, but its efficacy in reducing vertebral fracture rates and its effect on BMD at cortical sites are ... [more ▼]

BACKGROUND: Fluoride is effective in increasing trabecular bone mineral density (BMD) in the spine, but its efficacy in reducing vertebral fracture rates and its effect on BMD at cortical sites are controversial. OBJECTIVE: To study the effect of low-dose fluoride (sodium monofluorophosphate [MFP]) plus a calcium supplement over 4 years on vertebral fractures and BMD at the lumbar spine and total hip in postmenopausal women with moderately low BMD of the spine. DESIGN: Randomized, double-blind, controlled clinical trial. SETTING: Outpatient clinic for osteoporosis at a university medical center. PATIENTS: 200 postmenopausal women with osteoporosis (according to the World Health Organization definition) and a T-score less than -2.5 for BMD of the spine. INTERVENTION: Women were randomly assigned (100 patients per group) to continuous daily treatment for 4 years with 1) oral MFP (20 mg of equivalent fluoride) plus 1000 mg of calcium (as calcium carbonate) or 2) calcium only. MEASUREMENTS: Lateral spine radiographs were taken at enrollment and at each year of follow-up for detection of new vertebral fractures (defined as a reduction > or =20% and > or =4 mm from baseline in any of the heights of a vertebral body). Nonvertebral fractures were also recorded. All analyses were done with the intention-to-treat approach. RESULTS: Radiologic follow-up was possible for 164 of 200 patients (82%). The rate of new vertebral fractures during the 4 years of the study was lower in the MFP-plus-calcium group (2 of 84 patients; 2.4% [95% CI, 0.3% to 8.3%]) than in the calcium-only group (8 of 80 patients; 10% [CI, 4.4% to 18.8%]). The difference between the groups was 7.6 percentage points (CI, 0.3 to 15 percentage points) (P = 0.05). A moderate but progressive increase in BMD of the spine (10.0% +/- 1.5% at 4 years) was found for MFP plus calcium compared with calcium only (P < 0.001), whereas the more modest increase in BMD of the total hip seen with MFP plus calcium (1.8% +/- 0.6%) did not differ from the increase seen with calcium only. CONCLUSIONS: Low-dose fluoride (20 mg/d) given continuously with calcium for prolonged periods can decrease vertebral fracture rates compared with calcium alone in patients with mild to moderate osteoporosis. [less ▲]

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See detailEffect of sodium nitroprusside on complement activation induced by cardiopulmonary bypass: A clinical and experimental study
Seghaye, Marie-Christine ULg; Duchateau, J.; Grabitz, R. G. et al

in Journal of Thoracic and Cardiovascular Surgery (1996), 111(4), 882-892

Complement activation and leukocyte stimulation were prospectively studied during and after cardiopulmonary bypass in 16 children receiving sodium nitroprusside-a nitrovasodilator releasing nitric oxide ... [more ▼]

Complement activation and leukocyte stimulation were prospectively studied during and after cardiopulmonary bypass in 16 children receiving sodium nitroprusside-a nitrovasodilator releasing nitric oxide-for vasodilation during the cooling and rewarming periods of extracorporeal circulation. Results were compared with those in 29 patients who were not treated with sodium nitroprusside during the operation. Patients treated with sodium nitroprusside had significantly less C3 conversion during cardiopulmonary bypass as measured by the ratio C3d/C3 (p < 0.05) and significantly less C5a liberation immediately after cardiopulmonary bypass (p < 0.005) than patients not treated with sodium nitroprusside. C4 was not overtly consumed in our series. Leukocyte count during the rewarming period of cardiopulmonary bypass, but not leukocyte elastase release during cardiopulmonary bypass, was significantly reduced in patients treated with sodium nitroprusside (p < 0.05). In vitro experiments were conducted to analyze the effect of sodium nitroprusside on complement hemolytic activity initiated by the classic and the alternate pathways and on zymosan-induced C3 conversion by the activation of the alternate pathway. The in vitro experiments clearly demonstrate inhibition of complement hemolytic activity by sodium nitroprusside in the sera tested. The 50% inhibitory concentration of sodium nitroprusside on the available complement hemolytic activity was less through the alternate pathway than through the classic one (4.2 ± 0.8 mmol/L and 14.0 ± 2.88 mmol/L, respectively). The decrease of complement hemolytic activity measured was dose-dependent and was enhanced by the sodium nitroprusside preincubation of the sera tested. This effect was related to the duration of preincubation. Sodium nitroprusside photodegradation (enhancing nitric oxide release) increased the anticomplementary effect of the drug, reducing the 50% inhibitory concentration on complement hemolytic activity to 0.24 to 0.02 mmol/L for the alternate pathway and 2.74 o 0.3 mmol/L for the classic pathway. The zymosan-induced C3 conversion was inhibited by sodium nitroprusside. Nitroglycerin and isosorbide dinitrate (other nitric oxide donors) had in vitro effects on complement hemolytic activity similar to those of nonphotodegraded sodium nitroprusside at similar concentrations (1 mmol/L). Our results suggest that sodium nitroprusside, both in vitro and in vivo, has an inhibiting effect on complement activation initiated by both classic and alternate pathways and that this effect is mediated by nitric oxide release from sodium nitroprusside. This is the first report on the anticomplementary effect of sodium nitroprusside by nitric oxide release. [less ▲]

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See detailEffect of soft sulfidization Ore : Kansanshi (Zambia) : HG5
Bastin, David ULg; Kottgen, Axel

Report (2009)

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See detailEffect of somatic growth on pulmonary function values in healthy Friesian cattle
Lekeux, Pierre ULg; Hajer, R.; Breukink, H. J.

in American Journal of Veterinary Research (1984), 45(10), 2003-2007

Growth-related changes in pulmonary function values (PFV) of cattle were investigated by a cross-sectional study of 40 healthy Dutch Friesian cattle, 3 days to 13 years of age and weighing 37 to 660 kg ... [more ▼]

Growth-related changes in pulmonary function values (PFV) of cattle were investigated by a cross-sectional study of 40 healthy Dutch Friesian cattle, 3 days to 13 years of age and weighing 37 to 660 kg. Technical and methodologic procedures and body conformation and condition were standardized. A regression analysis was done with 4 independent variables (body weight, thoracic perimeter, body surface area, and age) and with PFV measured in this study. Ventilation values, dynamic lung compliance, and viscous work of breathing changed linearly with somatic growth. Respiratory frequency, total pulmonary resistance, and arterial oxygen tension showed an exponential relationship with all the independent variables. On the other hand, intrapleural pressure values were weakly correlated with body size indexes. The most important growth-related changes in PFV occurred at approximately 1 year of age. A significant (P less than or equal to 0.05) difference between immature and mature cattle was shown for the blood-gas values and the specific values of the breathing mechanics. The dynamic lung compliance/lung weight was lower and the total pulmonary resistance X minute volume was higher in cattle than in other domestic mammals. The regression equation, giving the best fit of the data, was selected for each PFV. [less ▲]

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See detailEffect of somatic growth, strain and sex on double-chamber plethymosgraphic respiratory function values in healthy mice
Flandre, Th.; Leroy, Pascal ULg; Desmecht, Daniel ULg

in Journal of Applied Physiology (2003), 94(3), 1129-1136

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See detailEffect of somatic growth, strain and sex on double-chamber plethysmographic respiratory function values in healthy mice
Flandre, Thierry; Leroy, Pascal ULg; Desmecht, Daniel ULg

in Journal of Applied Physiology (2003), 94

Double-chamber plethysmography has been recognized since 1979 as a reference technique to measure pulmonary function values in guinea pigs, but it has not gained attention for use in mice. Theoretically ... [more ▼]

Double-chamber plethysmography has been recognized since 1979 as a reference technique to measure pulmonary function values in guinea pigs, but it has not gained attention for use in mice. Theoretically, however, this technique combines the advantages of single-chamber plethysmography with a quantitative assessment of flow and/or volume and a calculated resistance, the interpretation of which in terms of bronchoconstriction is not disputed. Here we show that, when appropriately preconditioned, mice are able to gradually grow accustomed to the apparatus and display extremely stable nasal and thoracoabdominal flow tracings. Overall, strain, sex, and somatic growth had a significant effect on pulmonary function values. The changes in specific airway resistance (sRaw) and enhanced pause (Penh) values were never in the same direction, indicating that they measure different things. The respiratory frequency was far higher in C57BL/6 compared with BALB/c mice. Peak flows, minute volume, specific tidal and minute volumes, and sRaw were also higher, but Penh was smaller. Males breathed at a higher frequency than females, leading to a higher minute volume. Nevertheless, the specific volumes were considerably higher among females. Penh was lower in males, whereas sRaw was identical in both sexes. Changes associated with somatic growth were rapid and important between 5 and 9 wk, then slowed down between 9 and 12-13 wk and became almost imperceptible after. [less ▲]

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See detailEffect of some extrusion parameters on ruminal and intestinal in sacco disappearance of pea (Pisum sativum) proteins ans starch.
Thewis, André ULg; Walhain, P.; Foucart, M.

in First European Conference of Grain Legumes, Angers (Fr), June 1-3, 1992 (1992, June)

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See detailEffect of some insecticides on acetylcholinesterase from beneficial insects: Coccinella septempunctata, Chrysoperla carnea and Forficula auricularia
Boszic, Andras; Francis, Frédéric ULg; Gaspar, Charles et al

in Med. Fac. Landbouw. Univ. Gent (2002), 67(3), 671-677

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See detailEffect of some organophosphate insecticides on acetylcholinesterase of adult Coccinella septempunctata (Coccinellidae)
Bozsik, Andras; Haubruge, Eric ULg; Gaspar, Charles

in Journal of Environmental Science & Health. Part. B, Pesticides, Food Contaminants, & Agricultural Wastes (1996)

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See detailEffect of Spinal Cord Stimulation on Regional Myocardial Perfusion Assessed by Positron Emission Tomography
de Landsheere, Christian ULg; Mannheimer, C.; Habets, A. et al

in American Journal of Cardiology (1992), 69(14), 1143-9

Spinal cord stimulation (SCS) can relieve symptoms in patients with severe angina pectoris refractory to conventional medical or surgical therapy. This symptomatic improvement may result from decreased ... [more ▼]

Spinal cord stimulation (SCS) can relieve symptoms in patients with severe angina pectoris refractory to conventional medical or surgical therapy. This symptomatic improvement may result from decreased myocardial ischemia. To test this hypothesis, positron emission tomography (PET) and potassium-38 as a flow tracer were used in 8 patients for the quantitative evaluation of regional myocardial perfusion at rest and after exercise, before and during SCS. Potassium uptake was evaluated as myocardial clearance (flow times net extraction) in ml/min/100 g. Tomographic segments were categorized as nonaffected and affected on the basis of the absence or presence of arterial stenosis on coronary angiography and on the basis of thallium scintigraphic data. In nonaffected segments, before SCS, regional myocardial clearance significantly increased from rest (28 +/- 4) to exercise (47 +/- 13 clearance units; p less than 0.004). A similar increase occurred after SCS. In affected segments, before SCS, regional myocardial clearance barely increased (p = 0.065) from rest (26 +/- 6) to exercise (33 less than or equal to 12). In comparison, after SCS, the resting regional myocardial clearance was slightly elevated (29 +/- 8) reflecting an increased double product, but did not increase (p = 0.192) with exercise (34 +/- 12). However, the magnitude and duration of ST-segment depression decreased during treatment with SCS. Anginal pain occurred in all patients during control exercise, but was attenuated in all but one with SCS. These results indicate that SCS improves exercise-induced angina and electrocardiographic signs of ischemia but this influence does not appear to be mediated by changes in regional myocardial perfusion. [less ▲]

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See detailThe effect of spontaneous self-reference on memory: a replication
Brédart, Serge ULg; François, Sarah; Guimond, Serge

in Année Psychologique (L') (2013), 113(2), 161-167

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See detailEffect of steam explosion pre-treatment on enzymatic saccharification of lignocellulosic material
Meyer, Laurence ULg; Jacquet, Nicolas ULg; Vanderghem, Caroline ULg et al

Poster (2011, September 08)

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to ... [more ▼]

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to produce biofuels. The “first generation” biofuels are highly controversial because of the use of food plant material. The aim of the “second generation” biofuels is to take lignocellulosic non-food plant material as raw material. Lignocellulosic biomass has a very complex structure made of linkages between lignins, cellulose and hemicelluloses. The saccharification of these lignocellulosic materials requires the fractionation of its constituents. Research has lead to many lignocellulosic biomass fractionation pre-treatments. This study particularly focuses on the steam explosion pretreatment followed by an enzymatic saccharification. Steam explosion is a thermomechanical process which allows the breakdown of the lignocellulosic material structure by the combined action of steam heating, hydrolysis induced by the organic acids formed during the process and shear stress resulting from the pressure rough drop. This treatment leads to modification of the physical parameters such as water retention capacity, cristallinity rate of the cellulosic fraction, hydrolysis of the hemicellulosic fraction and rearrangement in the lignin structure. Such modifications are supposed to make cellulose enzymatic hydrolysis from complex lignocellulosic material easier. In order to verify this hypothesis, different lignocellulosic raw materials have been pre-treated by steam explosion. These materials were sugar beet pulp, corn straw and miscanthus. In order to check the effect of steam explosion pre-treatment on cellulose, a microcrystalline cellulose was also treated. Steam explosion was performed at a vapor pressure of 18 bars and with a retention time of 2 minutes. The steam exploded lignocellulosic materials and the untreated one were submitted to a hydrolysis with a mixture of enzymes composed of cellulases and cellobiase activities during 24 hours. The quantification of glucose in the hydrolysates at different times was performed by HPAEC-PAD. Rate of cellulose converted into glucose were better with steam exploded raw material showing that steam explosion allows improvement of lignocellulosic material for enzymatic saccharification. [less ▲]

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See detailEffect of stellar rotation on oscillation frequencies
Ouazzani, R. M.; Goupil, M. J.; Dupret, Marc-Antoine ULg et al

in Astrophysics & Space Science (2010), 328

We investigate whether the rotational splittings of β Cephei stars can give some clue about the existence of a differential rotation in latitude, and if they are contaminated by the cubic order effects ... [more ▼]

We investigate whether the rotational splittings of β Cephei stars can give some clue about the existence of a differential rotation in latitude, and if they are contaminated by the cubic order effects of rotation on oscillation frequencies. We also study some properties of splitting asymmetries and axisymmetric mode frequencies which provide seismic constrains on the distortion of the star. We find that only non-perturbative methods are able to reproduce those two seismic characteristics within 0.01% error bars for stars when they rotate faster than 3.3% Ω [SUB] k [/SUB]. If error bars of 1% are acceptable, the threshold of validity of perturbative methods is extended to 10% Ω [SUB] k [/SUB]. [less ▲]

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