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See detailPhysiological and physico-chemical factors modulating ISR elicitor production by Pseudomonas putida
Jourdan, Emmanuel ULg; Ongena, MARC ULg; Adam, Akram et al

in Bulletin OILB/SROP = IOBC/WPRS Bulletin (2006), 29(2)

Abstract: A better understanding of biotic and environmental factors that regulate the production of active metabolites by beneficial rhizobacteria is crucial for optimising biocontrol under pratical ... [more ▼]

Abstract: A better understanding of biotic and environmental factors that regulate the production of active metabolites by beneficial rhizobacteria is crucial for optimising biocontrol under pratical conditions. In this study, we wanted to evaluate the effect of some parameters on the production of the plant defence elicitor synthesized by Pseudomonas putida BTP1. This molecule is clearly dependant of the secondary metabolism and chemostat experiments showed that the elicitor is more efficiently produced at a very low cell growth rate. On another hand, the presence of free amino acids in the medium is necessary to obtain an optimal NABD production. A specific positive effect of phenylalanine was evidenced in pulsed continuous cultures suggesting that this residue could play a role as a precursor and/or act as a regulator in the biosynthetic pathway. [less ▲]

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See detailPhysiological and proteomic evidences that domestication process differentially modulates the immune status of juvenile Eurasian perch (Perca fluviatilis) under chronic confinement stress.
Douxfils, J.; Mathieu, Cédric; Mandiki, S. N. et al

in Fish & Shellfish Immunology (2011), 159(1), 92-9

The current study aimed to evaluate the influence of domestication process on the stress response and subsequent immune modulation in Eurasian perch juveniles (Perca fluviatilis) submitted to chronic ... [more ▼]

The current study aimed to evaluate the influence of domestication process on the stress response and subsequent immune modulation in Eurasian perch juveniles (Perca fluviatilis) submitted to chronic confinement. Briefly, F1 and F4 generations were confined into small-size tanks and sampled 7 and 55 days after stocking. Cortisol and glucose levels as well as lysozyme activity and immunoglobulin level were evaluated in the serum. Spleen Somatic Index and spleen ROS production were also measured. A proteomic analysis was performed on serum sampled on day 7. Finally, both generations were genetically characterized using a microsatellite approach. Globally, results revealed that chronic confinement did not elicit a typical stress response but resulted in a prolonged immune stimulation. Proteomic results suggested that domestication process influenced the immune status of perch submitted to chronic confinement as the F1 confined fish displayed lower abundance of C3 complement component, transferrin and Apolipoprotein E. Microsatellite data showed a strong genetic drift as well as reduced genetic diversity, allelic number and heterozygosity along with domestication process. The present work is the first to report that fish under domestication can develop an immune response, assessed by a combined approach, following recurrent challenges imposed by captive environment despite a reduced genetic variation. [less ▲]

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See detailPhysiological and proteomic responses of different willow clones (Salix fragilis x alba) exposed to dredged sediment contaminated by heavy metals
Evlard, Aricia ULg; Sergeant, Kjell; Ferrandis, Salvador et al

in International Journal of Phytoremediation (2014), 16(11), 1148-1169

High biomass producing species are considered as tools for remediation of contaminated soils. Willows (Salix spp.) are prominent study subjects in this regard. In this study, different willow clones ... [more ▼]

High biomass producing species are considered as tools for remediation of contaminated soils. Willows (Salix spp.) are prominent study subjects in this regard. In this study, different willow clones (Salix fragilis x alba) were planted on heavy-metal polluted dredging sludge. A first objective was assessment of the biomass production for these clones. Using a Gupta statistic, four clones were identified as high biomass producers (HBP). For comparison, a group of four clones with lowest biomass production were selected (LBP). A second objective was to compare metal uptake as well as the physiological and proteomic responses of these two groups. All these complementary data's allow us to have a better picture of the health of the clones that would be used in phytoremediation programs. Cd, Zn, and Ni total uptake was higher in the HBPs but Pb total uptake was higher in LBPs. Our proteomic and physiological results showed that the LBPs were able to maintain cellular activity as much as the HBPs although the oxidative stress response was more pronounced in the LBPs. This could be due to the high Pb content found in this group although a combined effect of the other metals cannot be excluded. [less ▲]

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See detailPhysiological characterization of Biofidobacterium for probiotic use.
Majad, L.; Evrard, P.; Thonart, Philippe ULg

Poster (2003, June)

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See detailPhysiological consequences of strenuous concentric and eccentric isokinetic exercises
Croisier, Jean-Louis ULg; Maquet, Didier ULg; Lehance, Cédric ULg et al

in Isokinetics & Exercise Science (2007), 15(1), 51

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See detailPhysiological effects of experimental verminous bronchitis in Friesian calves
Lekeux, Pierre ULg; Hajer, R.; Boon, J. H. et al

in Canadian Journal of Comparative Medicine (Gardenvale, Quebec) (1985), 49(2), 205-207

Pulmonary function values were measured in five Friesian calves of five months of age during the patent phase of an experimental moderate lungworm infection and were compared with the pulmonary function ... [more ▼]

Pulmonary function values were measured in five Friesian calves of five months of age during the patent phase of an experimental moderate lungworm infection and were compared with the pulmonary function values recorded in four control animals. All the nine calves were free of any previous challenge with Dictyocaulus viviparus and were submitted to the same standardized conditions of body conformation, housing, feeding and procedures for pulmonary function testing. A significant increase of respiratory rate, minute ventilation, total pulmonary resistance and power of breathing and a significant decrease of tidal volume, dynamic lung compliance and PaO2 were observed in the infested animals. The absolute intrapleural pressure values were also significantly more negative. The conclusions of the statistical analysis were almost identical when predicted instead of measured pulmonary function values were used in the control group. The clinical, functional and pathological findings in the infested animals were all consistent with the picture of a lower airway obstructive disease. [less ▲]

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See detailPhysiological factors associated with the onset of sweating
Mairiaux, Philippe ULg; Libert, J. P.

in Japanese Journal of Physiology (The) (1987), 37(4), 699-714

The influence of esophageal (Tes) and skin temperature (Tsk) variations, body heat storage, and individual parameters on the initiation of sweating was investigated in 9 unacclimated subjects during ... [more ▼]

The influence of esophageal (Tes) and skin temperature (Tsk) variations, body heat storage, and individual parameters on the initiation of sweating was investigated in 9 unacclimated subjects during thermal transients induced by exercise (25, 50, or 75 W) and by a step change in ambient temperature from 28 degrees C to 23, 28, 36.5, 45, or 50 degrees C. Seventy-four onsets of sweating were observed during the exposures, the sweating delay averaging 3 min at 45 and 50 degrees C, 6 min at 36.5 degrees C, and 9.5 min at 28 degrees C. In warm conditions (36.5 to 50 degrees C), the onset of sweating could mainly be related both to the level of Tsk and its rate component, whereas in cooler conditions (28 and 23 degrees C), the onset of sweating could only be related to a positive rate of Tes variation, the Tsk level being low and steady. On the whole set of data, the Tes changes at the onset were inversely related to the Tsk changes. The cumulated heat storage at the onset of sweating was 37 kJ/m2 (S.D. 25). It varied not only among subjects (range: 11-66 kJ/m2) but also within subjects even when differences in thermal state prior to exercise were accounted for. Among the individual parameters investigated, the magnitude of the decrease in Tes observed in response to the start of exercise was found to have a significant effect on the sweating delay. The Tes decrease was inversely related to the subject's skinfold thickness, and in a given subject, inversely related to the preexercise Tsk. It is concluded that the results are in agreement with a summation model of internal and mean skin temperatures on the sweating drive but that they do not verify the hypothesis of a critical level of heat storage at the onset of sweating. [less ▲]

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See detailPhysiological indicators of dehydration in broiler chickens
Vanderhasselt, R.; Sprenger, M.; Everaert, Nadia ULg et al

Poster (2010)

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See detailPhysiological interpretation of the slope during an isokinetic fatigue test of the knee
Bosquet, L.; Gouadec, K.; Berryman, N. et al

in European Journal of Sports Medicine (2013, September), 1(1), 151

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See detailPhysiological measurements in horses after strenuous exercise in hot, humid conditions
Art, Tatiana ULg; Votion, Dominique ULg; Lekeux, Pierre ULg

in Equine Veterinary Journal. Supplement (1995), 20

The purpose of this study was 1) to measure and compare some physiological parameters in horses during a standardised treadmill exercise performed either in temperate atmospheric conditions (TC) (ambient ... [more ▼]

The purpose of this study was 1) to measure and compare some physiological parameters in horses during a standardised treadmill exercise performed either in temperate atmospheric conditions (TC) (ambient temperature: 15 degrees C; relative humidity: 55%), or in hot and humid conditions (HHC) (ambient temperature: 30 degrees C; relative humidity: 75%) and 2) to follow the recovery of the same horses during 1 h after both tests. Five healthy fit Standardbred horses were investigated twice at 8 days interval, in TC and in HHC. Some measurements were made during a standardised treadmill exercise test (SET), others during a 1 h recovery period. The SET consisted of 8 min warm-up and 8 min exercise. During the SET, respiratory airflow and O2 and CO2 fraction in the respiratory gases were continuously recorded, using 2 ultrasonic pneumotachographs connected to a face mask and a mass spectrometer. Oxygen uptake (VO2), carbon dioxide output, respiratory quotient and expired minute volume (VE) were obtained on a breath-by-breath basis. The maximal values obtained during the highest intensity of the SET and the values obtained 2 min after the end of the test were used for the comparison between both tests. Heart rate (HR) and skin temperature were continuously recorded, using a heart rate recording system and a real time infrared thermographic unit, respectively. After both SETs in TC and HHC, the horses recovered in TC. Heart rate, respiratory frequency (f) and rectal temperature were regularly measured during 1 h after the test. Venous blood was sampled after the completion of the test for biochemical analysis, namely plasma electrolytes and enzymatic activities. Exercising in HHC induced a reduction of the aerobic metabolism to the total energy requirement, i.e. a 20% decrease of VO2 and 55% increase in lactate, as well as a decrease in VE. The increase in rectal and skin temperature, the dehydration and the weight loss were higher in HHC than in TC. During the recovery period the HR and f remained higher up to 30 min after the end of the SET in HHC while the rectal temperature remained higher up to 60 min after the end of this test. Therefore, despite the fact that our horses recovered in TC after exercising in HHC, there were significant differences between their physiological parameters measured during the recovery. This means that the recovery in air-conditioned unit would probably be an insufficient measure to ensure an adequate cooling of the horses and justify consequently the adaptations proposed by the Federation Equestre Internationale (FEI), i.e. the decrease of the distance of the run and the increase of the time devoted to the halt between phases [less ▲]

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See detailPhysiological mechanisms
Macar, F.; Greenwood, P.; Lejeune, Helga ULg et al

in Richelle, Marc; Lejeune, Helga (Eds.) Time in animal behaviour (1980)

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See detailPhysiological modeling, tight glycemic control, and the ICU clinician: what are models and how can they affect practice?
Chase, J. Geoffrey; Le Compte, Aaron J.; Preiser, Jean-Charles et al

in Annals of Intensive Care (2011), 1:11

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See detailA physiological overview of the genetics of flowering time control.
Bernier, Georges ULg; Périlleux, Claire ULg

in Plant Biotechnology Journal (2005), 3(1), 3-16

Physiological studies on flowering time control have shown that plants integrate several environmental signals. Predictable factors, such as day length and vernalization, are regarded as 'primary', but ... [more ▼]

Physiological studies on flowering time control have shown that plants integrate several environmental signals. Predictable factors, such as day length and vernalization, are regarded as 'primary', but clearly interfere with, or can even be substituted by, less predictable factors. All plant parts participate in the sensing of these interacting factors. In the case of floral induction by photoperiod, long-distance signalling is known to occur between the leaves and the shoot apical meristem (SAM) via the phloem. In the long-day plant, Sinapis alba, this long-distance signalling has also been shown to involve the root system and to include sucrose, nitrate, glutamine and cytokinins, but not gibberellins. In Arabidopsis thaliana, a number of genetic pathways controlling flowering time have been identified. Models now extend beyond 'primary' controlling factors and show an ever-increasing number of cross-talks between pathways triggered or influenced by various environmental factors and hormones (mainly gibberellins). Most of the genes involved are preferentially expressed in meristems (the SAM and the root tip), but, surprisingly, only a few are expressed preferentially or exclusively in leaves. However, long-distance signalling from leaves to SAM has been shown to occur in Arabidopsis during the induction of flowering by long days. In this review, we propose a model integrating physiological data and genes activated by the photoperiodic pathway controlling flowering time in early-flowering accessions of Arabidopsis. This model involves metabolites, hormones and gene products interacting as long- or short-distance signalling molecules. [less ▲]

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See detailPhysiological relevance and performance of a minimal lung model -- an experimental study in healthy and acute respiratory distress syndrome model piglets
Chiew, Y. S.; Chase, J. G.; LAMBERMONT, Bernard ULg et al

in BMC Pulmonary Medicine (2012), 12:59

Background: Mechanical ventilation (MV) is the primary form of support for acute respiratory distress syndrome (ARDS) patients. However, intra- and inter- patient-variability reduce the efficacy of ... [more ▼]

Background: Mechanical ventilation (MV) is the primary form of support for acute respiratory distress syndrome (ARDS) patients. However, intra- and inter- patient-variability reduce the efficacy of general protocols. Model-based approaches to guide MV can be patient-specific. A physiological relevant minimal model and its patient-specific performance are tested to see if it meets this objective above. Methods: Healthy anesthetized piglets weighing 24.0 kg [IQR: 21.0-29.6] underwent a step-wise PEEP increase manoeuvre from 5cmH2O to 20cmH2O. They were ventilated under volume control using Engstrom Care Station (Datex, General Electric, Finland), with pressure, flow and volume profiles recorded. ARDS was then induced using oleic acid. The data were analyzed with a Minimal Model that identifies patient-specific mean threshold opening and closing pressure (TOP and TCP), and standard deviation (SD) of these TOP and TCP distributions. The trial and use of data were approved by the Ethics Committee of the Medical Faculty of the University of Liege, Belgium.Results and discussions3 of the 9 healthy piglets developed ARDS, and these data sets were included in this study. Model fitting error during inflation and deflation, in healthy or ARDS state is less than 5.0% across all subjects, indicating that the model captures the fundamental lung mechanics during PEEP increase. Mean TOP was 42.4cmH2O [IQR: 38.2-44.6] at PEEP = 5cmH2O and decreased with PEEP to 25.0cmH2O [IQR: 21.5-27.1] at PEEP = 20cmH2O. In contrast, TCP sees a reverse trend, increasing from 10.2cmH2O [IQR: 9.0-10.4] to 19.5cmH2O [IQR: 19.0-19.7]. Mean TOP increased from average 21.2-37.4cmH2O to 30.4-55.2cmH2O between healthy and ARDS subjects, reflecting the higher pressure required to recruit collapsed alveoli. Mean TCP was effectively unchanged. Conclusion: The minimal model is capable of capturing physiologically relevant TOP, TCP and SD of both healthy and ARDS lungs. The model is able to track disease progression and the response to treatment. [less ▲]

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See detailPhysiological Relevance of a Minimal Model in Healthy Pigs Lungs
Chiew, YS; Desaive, Thomas ULg; LAMBERMONT, Bernard ULg et al

in Proceedings of BMS 2012 (2012)

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See detailPhysiological response of yeast to process perturbations: A mini-bioreactor approach
Lejeune, Annick ULg; Delvigne, Frank ULg; Thonart, Philippe ULg

in Cerevisia : Belgian Journal of Brewing and Biotechnology (2013), 38(1), 15-19

Large-scale production of yeast (Saccharomyces cerevisiae) is difficult to control, considering the drop of mixing and mass transfer efficiency during scale-up. The drop of hydrodynamic efficiency in ... [more ▼]

Large-scale production of yeast (Saccharomyces cerevisiae) is difficult to control, considering the drop of mixing and mass transfer efficiency during scale-up. The drop of hydrodynamic efficiency in large-scale bioreactors induces the formation of heterogeneities, i.e. mainly substrate and dissolved oxygen in process conditions. These extracellular fluctuations have several impacts at the level of the physiology of microorganisms, from metabolic shift to specific gene expression (stress response). Microbial cell responses to extracellular fluctuations are actually not fully understood. In this work, we propose to reproduce the main extracellular fluctuations at the level of a mini bioreactor platform. These mini-reactors are shake flasks equipped with dissolved oxygen probes. The cultures are realized with different fed-batch control strategies. A scale-down approach has been developed by considering slow release techniques and intermittent feeding, in order to reproduce the glucose and dissolved oxygen fluctuations experienced in large-scale reactors. The mini-reactor has been used to screen the response of several green fluorescent protein (GFP) reporter strains (adh2, tps2, pdc6 and hxt2). The GFP content of cells has been determined by flow cytometry in order to take into account population heterogeneity. In front of these results, the methodology presented in this work can be proposed as a scale-down tool. [less ▲]

Detailed reference viewed: 27 (15 ULg)