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See detailA flow cytometric study on the effect of myeloperoxidase on stallion spermatozoal motility and structure
Ponthier, Jérôme ULg; Parrilla Hernandez, Sonia ULg; Van Den Berghe, Femke ULg et al

in Journal of Equine Veterinary Science (2012, August), 32(8), 509

Myeloperoxidase (MPO) is a pro-oxidant enzyme that is normally contained in neutrophils. MPO has recently been associated with keratinized cells and with decreased post-thaw motility in stallion semen [1 ... [more ▼]

Myeloperoxidase (MPO) is a pro-oxidant enzyme that is normally contained in neutrophils. MPO has recently been associated with keratinized cells and with decreased post-thaw motility in stallion semen [1]. The aim of the study was to determine effects of experimental addition of active MPO on motility, mitochondrial potential, apoptosis induction, membrane and acrosome integrity in equine semen. Three stallions were used and semen was collected four times. Extended (INRA96TM) semen was processed for density gradient centrifugation (Equipure Bottom Layer®) [2]. Purified pellet was re-extended to 100x106spermatozoa/ml in INRA96TM and divided in 3 samples. One sample was used for control and active human MPO (Calbiochem, Merck) was added in the other two samples to final concentration of 5 or 50 ng/ml. After incubation (2 hours, 20°C), motility was analysed with Computer Assisted Semen Analysis (IVOS, Hamilton-Throne, Beverly, MA, USA) and cytometric analyzes were perfomed with EasyCyte (IMV). Mitochondrial potential and apoptosis were assayed using Guava Mitopotential JC-1 and 7-AAD kit (Millipore). Membrane and acrosome integrity were respectively assayed with PI (Propidium Iodide) (Invitrogen) and PNA (Peanut Agglutinin-Fluorescein Iso Thio Cyanate) (Sigma-Aldrich). Statistical differences (p<0.05) were determined using Kruskall-Wallis test. No effect of the stallions was observed on parameters assayed in this study. Unlike total motility, progressive motility was decreased in both MPO concentrations (p<0.001). MPO addition had no effect on membrane and acrosome integrity. No differences were detected for the percentages of spermatozoa having polarised or depolarised mitochondria. Apoptosis, assayed by 7-AAD fluorescence, was not increased by the treatments. Our results agree with previously published effects of in vitro ROS production systems with xanthine oxidase [3], showing an effect on motility but no influence on mitochondria and membrane or acrosome integrity. However, membrane lipoperoxidation was increased by ROS in this study [3], and it could be linked to the impaired motility also observed in our protocol. Further studies with increasing concentrations of added MPO should be conducted to correlate motility with lipoperoxidation. References [1] Ponthier J, Desvals M, Franck T, de la Rebiere de Pouyade G, Spalart M, Palmer E, Serteyn D, Deleuze S. Myeloperoxidase in equine semen: Concentration and Localization during freezing processing. Journal of Equine Veterinary Science 2012;32: 32-37. [2] Edmond AJ, Teague SR, Brinsko SP, Comerford KL, Waite JA, Mancill SS, Love CC, Varner DD. Effect of density-gradient centrifugation on quality and recovery rate of equine spermatozoa. Animal Reproduction Science 2008;107: 318-318. [3] Baumber J, Ball BA, Gravance CG, Medina V, Davies-Morel MC. The effect of reactive oxygen species on equine sperm motility, viability, acrosomal integrity, mitochondrial membrane potential, and membrane lipid peroxidation. J Androl 2000;21: 895-902. [less ▲]

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See detailFlow cytometry estimation of nuclear size and ploidy level of habituated calli of sugar beet
Kevers, Claire ULg; Greimers, Roland ULg; Franck, Thierry ULg et al

in Biologia Plantarum (1999), 42(3), 321-332

A fully habituated (auxin- and cytokinin-independent) self-regenerating (organogenic) sugar beet cell line (HO) and a fully habituated non-organogenic one (HNO) derived from the former one, were analyzed ... [more ▼]

A fully habituated (auxin- and cytokinin-independent) self-regenerating (organogenic) sugar beet cell line (HO) and a fully habituated non-organogenic one (HNO) derived from the former one, were analyzed as to their nuclear size and DNA content. Flow cytometry and image analysis were used and cells of certified diploid leaves of the same sugar beet strain served as controls. The HNO cells had been shown previously to have many characteristics of cancerous cells. The analyses made on leaves and HNO cells indicated the presence of only one population of cycling cells. In HO cells. two cycling populations were detected: the first one had the same DNA content as the leaves while the second one contained two fold more DNA than the first population. HNO cells showed the higher nuclear size and DNA content. HNO cells also showed evidence of aneuploidy. Thus, nuclear size, DNA content and ploidy level increase together with the neoplasic progression to culminate in HNO cells with the loss of organogenic totipotency. [less ▲]

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See detailFlow Cytometry for the follow-up of Trypanosoma evansi infection in a mouse model
Antoine-Moussiaux, Nicolas ULg; Leroy, ; Faisca, et al

Poster (2005, November 18)

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See detailFlow cytometry for the follow-up of Trypanosoma evansi infection in a mouse model
Antoine-Moussiaux, Nicolas ULg; Leroy, ; Faisca, et al

Poster (2006, April)

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See detailFlow cytometry in prostate cancer: Histological and clinical correlation
de Leval, Laurence ULg; Waltregny, David ULg; Greimers, Roland ULg et al

in Acta Urologica Belgica (1994), 62(1), 37-43

DNA histograms were obtained by flow cytometry for 39 human prostate carcinomas (27 total prostatectomy specimens, 5 biopsies and 7 transuretral resections). The study was performed on formalin-fixed and ... [more ▼]

DNA histograms were obtained by flow cytometry for 39 human prostate carcinomas (27 total prostatectomy specimens, 5 biopsies and 7 transuretral resections). The study was performed on formalin-fixed and paraffin-embedded material. In this report, ploidy index did not seem to be a good marker of prognosis as no significant variation in ploidy was found neither among the different stages nor among the different Gleason categories. Proliferative index of the tumors seemed to be a more sensitive parameter; a significant relation was observed between proliferative index and stage of the tumor. The authors discuss these results under the light of previously reported observations. [less ▲]

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See detailFlow in shallow rectangular basins: experimental study and 2D numerical simulations
Kantoush, Sameh A.; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in Proc. 8th International Conference on Hydro-Science and Engineering (ICHE) (2008)

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See detailFlow interruption effects on intake rate and rill erosion in two soils
Sirjacobs, Damien ULg; Shainberg, Itzhak; Rapp, Ido et al

in Soil Science Society of America Journal (2001), 65

Efficiency of surface irrigation is often low because of poor infiltration uniformity, resulting from relatively long periods of infiltration at the upstream end and short periods of infiltration at the ... [more ▼]

Efficiency of surface irrigation is often low because of poor infiltration uniformity, resulting from relatively long periods of infiltration at the upstream end and short periods of infiltration at the downstream end of the field. Surge irrigation, the intermittent supply of water to furrows, generally reduces soil intake rate (IR) and improves moisture uniformity over the entire field. However, IR reduction varies from one irrigation scheme to another, depends on soil and water properties, and is difficult to predict. A laboratory study using miniflumes was designed to investigate the effect of interrupted flow on IR and soil loss from short rills. Two soils differing in their textures, a silt loam (Calcic Haploxeralf) derived from loess and a clay soil (Typic Haploxerert), were studied. Intake rate in the clay soil was greater than that in the silt loam. Therefore, different inflow rates were applied to the two soils to achieve similar runoff flow rates from the two soils. Cumulative infiltration decreased from 646 mL in continuous flow to 539 mL in interrupted flow for the silt loam and from 1142 to 1068 mL in the clay soil. Interrupted flow also reduced cumulative soil loss by 84% in the clay soil but had only a small effect on soil loss from the silt loam. However, when flow rate was increased from 80 to 320 mL min−1, interrupted flow reduced soil loss in the silt loam as much as in the clay soil. Consolidation of the soil surface and formation of cohesive forces between soil particles of the silt loam with unstable structure during flow interruption was suggested as the explanation for the effect of flow interruption on intake rate and soil detachment. These results need to be verified in field experiments. [less ▲]

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See detailFlow modeling in an underground gasifier at great depth by the Boundary-Element Method
MATHY, B.; PIRLOT, Pierre; Pirard, Jean-Paul ULg et al

in In Situ (1994), 18(4), 399-418

In order to simulate the cavity growth of an underground gasifier in thin seams at great depth, Wilks1 has developed an original model that solves the continuity equation in the horizontal plane with the ... [more ▼]

In order to simulate the cavity growth of an underground gasifier in thin seams at great depth, Wilks1 has developed an original model that solves the continuity equation in the horizontal plane with the hypothesis of radial fluid flow around the injection well. In the model presented here, the continuity equation in the horizontal plane has been taken into account, removing the limiting assumption on flow (radial direction) assumed by Wilks. The simultaneous solution of the continuity equation and the Darcy law has been carried out using the Boundary Element Method (BEM); this method is particularly suitable for solving problems where boundary conditions are of prime importance. The model enables the influences of the permeability of the medium and gasifier geometry to be demonstrated. [less ▲]

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See detailFlow of magnetized grains in a rotating drum
Lumay, Geoffroy ULg; Vandewalle, Nicolas ULg

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2010)

We have experimentally investigated the influence of a magnetic interaction between the grains on the flow of a granular material in a rotating drum.

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See detailFlow Pattern Evolution With Time Mixing Of Non-Newtonian Fluid In A Stirred Tank Using Particle Image Velocimetry
Fransolet, Emmanuelle; Marchot, Pierre ULg; Toye, Dominique ULg et al

in American Society of Mechanical Engineering (ASME) (Ed.) Proccedings of 7th Biennal ASME Conference, Engineering Systems Design and Analysis – ESDA 2004, Manchester, United Kingdom,19 – 22 July 2004 (2004)

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See detailFlow patterns and sediment deposition in rectangular shallow reservoirs
Dufresne, Matthieu; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in Water & Environment Journal (2012), 26(4), 504-510

This work involves the experimental investigation of flow patterns, preferential regions of deposition and trapping efficiency in rectangular shallow reservoirs. The main flow patterns that can be ... [more ▼]

This work involves the experimental investigation of flow patterns, preferential regions of deposition and trapping efficiency in rectangular shallow reservoirs. The main flow patterns that can be encountered in rectangular shallow reservoirs are described: symmetrical flows without any reattachment point (S0), asymmetrical flows with one reattachment point (A1), and asymmetrical flows with two reattachment points (A2). The influence of geometrical and hydraulic parameters on reattachment lengths is intensively investigated. A shape parameter is introduced to classify symmetrical and asymmetrical flows. For each flow pattern, the preferential regions of deposition are studied. To conclude, a number of practical recommendations are given. Reservoirs with a shape parameter lower than 6.2 limit sediment deposition. Reservoirs with a shape parameter greater than 6.8 are favourable for sediment deposition. Finally, perspectives for maximizing and minimizing deposition are given, respectively by exploiting the great trapping potential of the flow pattern A1 and the poor trapping potential of the flow pattern S0. [less ▲]

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See detailFlow Processing and the Rise of Commodity Network Hardware
Greenhalgh, Adam; Huici, Felipe; Hoerdt, Mickael et al

in ACM SIGCOMM Computer Communication Review (2009)

The Internet has seen a proliferation of specialized middlebox devices that carry out crucial network functionality such as load balancing, packet inspection and intrusion detection. Recent advances in ... [more ▼]

The Internet has seen a proliferation of specialized middlebox devices that carry out crucial network functionality such as load balancing, packet inspection and intrusion detection. Recent advances in CPU power, memory, buses and network connectivity have turned commodity PC hardware into a powerful network platform. Furthermore, commodity switch technologies have recently emerged offering the possibility to control the switching of flows in a fine-grained manner. Exploiting these new technologies, we present a new class of network architectures which enables flow processing and forwarding at unprecedented flexibility and low cost. [less ▲]

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See detailFlow rate dependency of critical wall shear stress in a radial-flow cell
Detry, Jean G; Jensen, Bo Boye Busk; Sindic, Marianne ULg et al

in Journal of Food Engineering (2009), 92(1), 86-99

In the present work, a radial-flow cell was used to study the removal of starch particle aggregates from several solid substrates (glass, stainless steel, polystyrene and PTFE) in order to determine the ... [more ▼]

In the present work, a radial-flow cell was used to study the removal of starch particle aggregates from several solid substrates (glass, stainless steel, polystyrene and PTFE) in order to determine the critical wall shear stress value for each case. The particle aggregates were formed by aspersion of a water or ethanol suspension of starch granules on the surfaces. Depending on the substrate and on the suspending liquid, the aggregates differed in size and shape. Aggregate removal was studied at two flow rates. At the lower flow rate (Re-inlet = 955), the values of critical wall shear stress for the different surfaces suggested that capillary forces were, for all of them, playing an important role in aggregate adhesion since aqueous based aggregates were always more difficult to remove. At the higher flow rate (Re-inlet = 2016) the critical wall shear stress increased as a result of the change in the flow pattern in the vicinity of the aggregates and not because of changes in the type of particle adhesion. This raises the importance of the experimental conditions on assessing the critical wall shear stress since this parameter may not be always only directly related to the soil adhesion strength. (C) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailFlow rate quality of new flat fan nozzles
Huyghebaert, Bruno; Debouche, Charles ULg; Mostade, Olivier

in Transactions of the ASAE (2001), 44(4), 769-773

Manufacturers of spraying nozzles have established manufacturing tolerances to guarantee the quality of their products. They control, among other things, the new nozzles’ flow rate by comparison with the ... [more ▼]

Manufacturers of spraying nozzles have established manufacturing tolerances to guarantee the quality of their products. They control, among other things, the new nozzles’ flow rate by comparison with the nominal flow rate. When the deviation exceeds a set limit, the nozzles are rejected. A survey carried out among three manufacturers made it possible to determine the manufacturing tolerances and limits that manufacturers impose upon themselves. The flow rates of 1565 new nozzles collected on the market from these manufacturers were measured on a device developed for this study. Different statistical tests assessed the performances and characteristics of the products. The quality standards announced by the manufacturers were not checked for every nozzle. On average, 20% of the new nozzles exceeded the manufacturing tolerances. The average flow rate of the nozzle sets equalled the nominal flow rate. In practice, the probability distribution of the flow rate of new nozzles should be normal. The dispersion of the new nozzle flow rates was slightly higher than the theoretical one. The quality of the products differed from one manufacturer to another. [less ▲]

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See detailThe flow structure of the Norwegian Atlantic Current
Hopkins, T. S.; Mouchet, Anne ULg; Giannecchinni, P.

Conference (1989, March)

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See detailFlow through porous media
Dassargues, Alain ULg

Scientific conference (1995)

Detailed reference viewed: 6 (0 ULg)
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See detailFlow Visualization and Proper Orthogonal Decomposition of Aeroelastic Phenomena
Andrianne, Thomas ULg; Norizham, Abdul Razak ULg; Dimitriadis, Grigorios ULg

in Okamoto, Satoru (Ed.) Wind Tunnels (2011)

The modal decomposition of unsteady flowfields was proposed in the 1990s by several authors. Proper Orthogonal Decomposition (POD) is one method that can be used in order to perform this modal ... [more ▼]

The modal decomposition of unsteady flowfields was proposed in the 1990s by several authors. Proper Orthogonal Decomposition (POD) is one method that can be used in order to perform this modal decomposition; it became popular for aerodynamics research in the 2000s, although it was first proposed for use in fluid dynamics in the 1960s. The objective of the present work is to expand the methodology of the application of POD to experimental flowfields. There are two aspects to this expansion: 1. Allow the models to oscillate. The source of the unsteadiness will then be the movement of the model, as well as any unsteadiness due to flow separation. 2. Study the interaction between the different sources of unsteadiness. In particular observe how the modes generated by one source of unsteadiness interact with the modes generated by the other. Determine if it is possible to separate the structural from the aerodynamic sources of unsteadiness. [less ▲]

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