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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 ▲]

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See detailPhysiological response to the cross country phase in eventing horses
Amory, Hélène ULg; Art, Tatiana ULg; Linden, Annick ULg et al

in Journal of Equine Veterinary Science (1993), 13

Blood samples were collected for lactate concentration determination (Lacc) at the arrival of the cross-country phase from 40 horses of various class levels competing in 6 different three-day events ... [more ▼]

Blood samples were collected for lactate concentration determination (Lacc) at the arrival of the cross-country phase from 40 horses of various class levels competing in 6 different three-day events. Moreover, in 8 horses, heart rate (HR) was recorded every 5 seconds during the cross-country. Among them, 5 horses were submitted, at the beginning of the competition's season to a standardized exercise test (SET) on a track which allowed us to study the relationship between HR, blood lactate concentration and running speed on flat ground in these horses. The relationship between mean HR and mean speed, between Lacc and mean speed and between Lacc and HR during the cross-country were studied using regression analysis. Mean HR during the cross-country was linearly related to mean speed during this phase (r=0.87, p ≤ 0.01), but this relationship was shifted upwards in comparison with the corresponding curve obtained during the SET (r=0.97, p ≤ 0.001). In the same way, the relationship between Lacc and mean speed during the cross-country was exponential (r=0.93, p ≤ 0.001), but blood lactate accumulation occurred at a lower speed than during the SET (r=0.94, p ≤ 0.001). The correlation between Lacc and HR was stronger when Lacc was related to HR during the 15 last minutes of the cross (r = 0.84) than to mean HR during the whole cross (r = 0.75) or to HR during the 2 last (r = 0.74) or the last (r = 0.80) minute of the course, which indicated that continuous recording of HR allowed a more accurate estimation of the severity of exercise performed during the cross-country than Lacc. Heart rate ranged from 170 to 190 beats/min during the first part of the cross-country and reached or exceeded values of 190 to 200 beats/min at the end of the course. Therefore, the anaerobic threshold is reached during cross-country. Recruitment of anaerobic me tabolism at the end of the course was otherwise demonstrated by the high values of Lacc. These aerobic-anaerobic meta bolic requirements should be taken into account to design the training program of an eventing horse. [less ▲]

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See detailPhysiological responses of the scleractinian coral Pocillopora damicornis to bacterial stress from vibrio coralliilyticus
Vidal-Dupiol, Jérémie; Ladrière, Ophélie ULg; Meistertzheim, Anne-Leila et al

in Journal of Experimental Biology (2011), 214

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See detailPhysiological role of the putative ammonium transporter RhCG in the mouse
Biver, Sophie ULg; Scohy, Sophie; Szpirer, Josiane et al

in Transfusion Clinique et Biologique (2006), 13(1-2), 167-168

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See detailPhysiological role of the putative ammonium transporter RhCG in the mouse
Biver, Sophie ULg; Scohy, Sophie; Szpirer, Josiane et al

Conference (2006, May 05)

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See detailThe physiological status of the ovarian donor affects the in-vitro development of isolated bovine preantral follicles
FIGUEIREDO, J. R.; HULSHOF, S. C. J.; VANDENHURK, R. et al

in Theriogenology (1994), 42(8), 1303-1310

Described in the present paper is the effect of the physiological status of the ovarian donor on the development of isolated bovine preantral follicles during 5 d of culture. The preantral follicles were ... [more ▼]

Described in the present paper is the effect of the physiological status of the ovarian donor on the development of isolated bovine preantral follicles during 5 d of culture. The preantral follicles were isolated mechanically from ovaries of calves, or nonpregnant, pregnant and postpartum cows collected at the slaughterhouse. There were no differences observed among calves, nonpregnant and pregnant cows, neither in the percentages of morphologically normal follicles, nor in the mean diameter increase during culture. However, preantral follicles isolated from postpartum animals had a lower viability during culture, as demonstrated by significantly lower percentages of morphologically normal and growing follicles as well as by a levier mean diameter increase. Our findings show that the ovarian source may affect development of bovine preantral follicles in vitro, especially when preantral follicles from postpartum cows were used. [less ▲]

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See detailPhysiological studies of the pulmonary function in unsedated Friesian cattle
Lekeux, Pierre ULg

Doctoral thesis (1984)

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See detailPhysiological, pathophysiological and pharmacological studies of the mechanics of breathing in cattle
Lekeux, Pierre ULg; Amory, Hélène ULg; Art, Tatiana ULg et al

in Proceedings du Congrès National Vétérinaire Yougoslave (1990)

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See detailPhysiologically Based Pharmacokinetic (PBPK) Models for Lifetime Exposure to PCB 153 in Male and Female Harbor Porpoises (Phocoena phocoena): Model Development and Evaluation
Weijs, Liesbeth; Yang, Raymond; Covaci, Adrian et al

in Environmental Science & Technology (2010), 44

Physiologically based pharmacokinetic (PBPK) models were developed for the most persistent polychlorinated biphenyl (PCB 153) in male and female harbor porpoises (Phocoena phocoena) to elucidate processes ... [more ▼]

Physiologically based pharmacokinetic (PBPK) models were developed for the most persistent polychlorinated biphenyl (PCB 153) in male and female harbor porpoises (Phocoena phocoena) to elucidate processes such as uptake, distribution, and elimination. Due to its limited metabolic capacities, long life span, and top position in marine food chains, this species is highly sensitive to pollution. The models consist of 5 compartments, liver, blubber, kidney, brain, and a compartment which accounts for the rest of the body, all connected through blood. All physiological and biochemical parameters were extracted from the literature, except for the brain/blood partition coefficient and rate of excretion, which were both fitted to data sets used for validation of the models. These data sets were compiled from our own analyses performed with GCMS on tissue samples of harbor porpoises. The intake of PCB 153 was from milk from birth to 4 months, and after weaning fish was the main food source. Overall, these models reveal that concentrations of PCB 153 in males increase with age but suggest that,asthe animalsgrowolder, metabolic transformation can be a possible pathway for elimination as well. In contrast, the model for females confirms that gestation and lactation are key processes for eliminating PCB 153 as body burdens decrease with age. These PBPK models are capable of simulating the bioaccumulation of PCB 153 during the entire life span of approximately 20 years of the harbor porpoises. [less ▲]

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See detailPhysiologie
Stienon, Valérie ULg

in Aron, Paul; Saint-Jacques, Denis; Viala, Alain (Eds.) Le Dictionnaire du littéraire (2010)

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See detailPhysiologie (littéraire)
Stienon, Valérie ULg

in Grassin, Jean-Marie (Ed.) Le Dictionnaire International des Termes Littéraires (DITL) (2009)

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See detailPhysiologie Animale
Ancil, Michel; Baguet, Fernand; Charmantier, Mireille et al

Book published by De Boeck Université (2006)

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See detailPhysiologie de l'effort et médecine sportive équine
Art, Tatiana ULg; Lekeux, Pierre ULg

in Pratique Vétérinaire Equine (1991), 23(2), 5-14

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See detailLa physiologie de la branchie et la pression osmotique du sang de l'écrevisse
Fredericq, Léon ULg

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1898), XXXV

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See detailPhysiologie de la cellule enterochromaffin-like (ECL) dans la régulation de la sécrétion gastrique acide
Delwaide, Jean ULg; Belaiche, Jacques ULg; Latour, Pascale ULg

in Médecine & Chirurgie Digestives (1993), 22

Cette mise au point rappellera d'abord les grands mécanismes de la sécrétion gastrique acide en insistant sur le rôle pivot de l'histamine. Une question qui demeurait encore non résolue était de savoir ... [more ▼]

Cette mise au point rappellera d'abord les grands mécanismes de la sécrétion gastrique acide en insistant sur le rôle pivot de l'histamine. Une question qui demeurait encore non résolue était de savoir quelle était la cellule fundique qui produisait de l'histamine dans les conditions physiologiques. Deux cellules seront envisagées, les mastocytes et les cellules ECL qui sont des cellules endocrines exclusivement localisées dans le fundus. Quelques arguments seront développés, dont ceux provenant de notre expérience, permettant de penser que la cellule ECL contient de l'histamine. L'article se terminera par un essai d'intégration de la cellule ECL dans le schéma de la sécrétion gastrique acide en montrant son rôle essentiel potentiel. [less ▲]

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