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See detailLarge Scale Preparation of [18]Fluoromethoxybenzyl Bromides, Key Precursors for 2-[18F]Fluoro-L-Tyrosine and 6-[18F]Fluoro-L-Dopa
Libert, Lionel ULg; Lemaire, Christian ULg; Wouters, Ludovic ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 292

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See detailLarge Scale Preparation of Purified Exocellular DD-carboxypeptidase-Transpeptidase of Streptomyces Strain R61
Fossati, P.; Saint-Ghislain, M.; Sicard, P. J. et al

in Biotechnology and Bioengineering (1978), 20

The exocellular DD-carboxypeptidase–transpeptidase that Streptomyces R61 excretes during growth has been produced in large fermentation units of 15 m3 total capacity. The yield from 15,000 liter culture ... [more ▼]

The exocellular DD-carboxypeptidase–transpeptidase that Streptomyces R61 excretes during growth has been produced in large fermentation units of 15 m3 total capacity. The yield from 15,000 liter culture filtrate was 1.080 g purified enzyme (92% purity) with a total recovery of 29% and at least a 2000-fold increased specific activity. [less ▲]

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See detailLarge scale production of 13-hydroperoxilinolenic acid using soybean lipoxygenase
Fauconnier, Marie-Laure ULg; Dessart, V.; Marlier, M.

Conference (1996, September 26)

Detailed reference viewed: 18 (0 ULg)
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See detailLarge scale serological detection in Belgium of enzootic bovine leucosis.
Mammerickx, Marc; Otte, J.; Rase, F. et al

in Zentralblatt für Veterinarmedizin. Reihe B = Journal of Veterinary Medicine. Series B (1978), 25

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See detailLarge Scale Structural Optimization by Finite Elements
Fleury, Claude ULg

in Atrek, E.; Zienkiewicz, O. C.; Ragsdell, K. M. (Eds.) et al New Directions in Optimum Structural Design (1984)

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See detailLarge scale surface – subsurface hydrological model to assess climate change impacts on groundwater reserves
Goderniaux, Pascal ULg; Brouyère, Serge ULg; Fowler, Hayley J. et al

in Journal of Hydrology (2009), 373

Estimating the impacts of climate change on groundwater represents one of the most difficult challenges faced by water resources specialists. One difficulty is that simplifying the representation of the ... [more ▼]

Estimating the impacts of climate change on groundwater represents one of the most difficult challenges faced by water resources specialists. One difficulty is that simplifying the representation of the hydrological system often leads to discrepancies in projections. This study provides an improved methodology for the estimation of the impacts of climate change on groundwater reserves, where a physically-based surface – subsurface flow model is combined with advanced climate change scenarios for the Geer basin (465 km²), Belgium. Coupled surface–subsurface flow is simulated with the finite element model HydroGeoSphere. The simultaneous solution of surface and subsurface flow equations in HydroGeoSphere, as well as the internal calculation of the actual evapotranspiration as a function of the soil moisture at each node of the defined evaporative zone, improve the representation of interdependent processes like recharge, which is crucial in the context of climate change. More simple models or externally coupled models do not provide the same level of realism. Fully integrated surface – subsurface flow models have recently gained attention, but have not been used in the context of climate change impact studies. Climate change simulations were obtained from 6 regional climate model (RCM) scenarios assuming the SRES A2 emission (medium-high) scenario. These RCM scenarios were downscaled using a quantile mapping bias-correction technique that, rather than applying a correction only to the mean, forces the probability distributions of the control simulations of daily temperature and precipitation to match the observed distributions. The same corrections are then applied to RCM scenarios for the future. Climate change scenarios predict hotter and drier summer and warmer and wetter winters. The combined use of an integrated surface – subsurface modelling approach, a spatial representation of the evapotranspiration processes and sophisticated climate change scenarios improves the model realism and projections of climate change impacts on groundwater reserves. For the climatic scenarios considered, the integrated flow simulations show that significant decreases are expected in the groundwater levels (up to 8 meters) and in the surface water flow rates (between 9% and 33%) by 2080. [less ▲]

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See detailA LARGE STRAIN ELASTO-VISCOPLASTIC NUMERICAL MODEL
Careglio, Claudio; Canales Cardenas, Cristian ULg; Ribero, Melisa et al

in Bustamante, Roger (Ed.) Proceedings of PACAM XIV (2014)

A large strain elasto-viscoplastic Perzyna model was proposed by Ponthot. The resultant numerical model computes the elastic response using an hypoelastic model. A viscoplastic multiplier was proposed ... [more ▼]

A large strain elasto-viscoplastic Perzyna model was proposed by Ponthot. The resultant numerical model computes the elastic response using an hypoelastic model. A viscoplastic multiplier was proposed, then both inviscid (elastoplastic) and elastic limiting cases can be easily recovered. More recently the authors have included this viscoplastic model in a large strain constitutive model based on hyperelasticity and multiplicative decomposition of deformation gradient tensor. In this work a brief summary of both, hypoelastic and hyperelastic based large strain models of viscoplasticity is provided. Large strain examples are simulated in order to test the discussed models. Different parameters of the constitutive model are tested in order to study the sensitivity of the resultant algorithm. From the obtained results can be said that both models show a very good agree and represent very well the characteristic of the viscoplastic constitutive model. [less ▲]

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See detailLarge strain elasto/viscoplastic constitutive model. Theory and numerical scheme
Ponthot, Jean-Philippe ULg; GARCIA-GARINO, C.; MIRASSO, A.

in MECOM 2005, Mecanica Computational (2005)

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See detailLarge trees drive forest aboveground biomass variation in moist lowland forests accross the tropics
Slik, J. W. Ferry; Paoli, Gary; McGuire, Krista et al

in Global Ecology & Biogeography (2013), 22

Aim Large trees (d.b.h. 70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here ... [more ▼]

Aim Large trees (d.b.h. 70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore which intrinsic (species trait) and extrinsic (environment) variables are associated with the density of large trees and forest biomass at continental and pan-tropical scales. Location Pan-tropical. Methods Aboveground biomass (AGB) was calculated for 120 intact lowland moist forest locations. Linear regression was used to calculate variation in AGB explained by the density of large trees. Akaike information criterion weights (AICcwi) were used to calculate averaged correlation coefficients for all possible multiple regression models between AGB/density of large trees and environmental and species trait variables correcting for spatial autocorrelation. Results Density of large trees explained c. 70% of the variation in pan-tropical AGB and was also responsible for significantly lower AGB in Neotropical [287.8 (mean) 105.0 (SD) Mg ha-1] versus Palaeotropical forests (Africa 418.3 91.8 Mg ha-1; Asia 393.3 109.3 Mg ha-1). Pan-tropical variation in density of large trees and AGB was associated with soil coarseness (negative), soil fertility (positive), community wood density (positive) and dominance of wind dispersed species (positive), temperature in the coldest month (negative), temperature in the warmest month (negative) and rainfall in the wettest month (positive), but results were not always consistent among continents. Main conclusions Density of large trees and AGB were significantly associated with climatic variables, indicating that climate change will affect tropical forest biomass storage. Species trait composition will interact with these future biomass changes as they are also affected by a warmer climate. Given the importance of large trees for variation in AGB across the tropics, and their sensitivity to climate change, we emphasize the need for in-depth analyses of the community dynamics of large trees. [less ▲]

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See detailLarge white organic light-emitting diode lighting panel on metal foils
Guaino, Philippe; Mazeri, Fabrizo; Hofmann, Michael et al

in Journal of Photonics for Energy [=JPE] (2011), 1

Large-area top-emitting PIN structure (highly p- and n- type doped transport layers for electrons and holes and an undoped emitter layer)–organic light-emitting diode (OLED) on advanced metal foils were ... [more ▼]

Large-area top-emitting PIN structure (highly p- and n- type doped transport layers for electrons and holes and an undoped emitter layer)–organic light-emitting diode (OLED) on advanced metal foils were fabricated for lighting applications. ArcelorMittal has developed a new surface treatment on metal foils, suitable for roll-to-roll production and dedicated to large-area device integration. Both monochromatic and white devices are realized on advanced metal foils. Power efficiencies at 1000 cd/m2 of >70 lm/W (green), moreover, power efficiency of white devices of >22 lm/W are achieved. Furthermore, first large-area 60 × 60 cm white OLED sources on metal foils are presented. [less ▲]

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See detailLarge-distance effects on spin observables at RHIC
Selyugin, Oleg V; Cudell, Jean-René ULg; Predazzi, E.

in Aulenbacher, K.; Bradamante, F.; Bressan, A. (Eds.) et al 16th International Spin Physics Symposium (SPIN 2004) (2004)

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See detailLarge-Eddy Simulations of microcarrier exposure to potentially damaging eddies inside mini-bioreactors
Collignon, Marie-Laure ULg; Delafosse, Angélique; Calvo, Sébastien ULg et al

in Biochemical Engineering Journal (in press)

Mechanically stirred vessels equipped with rotating impellers generate heterogeneous transitional or turbulent flows. However, some cells as animal or human mesenchymal stem cells (hMSC) adhered on ... [more ▼]

Mechanically stirred vessels equipped with rotating impellers generate heterogeneous transitional or turbulent flows. However, some cells as animal or human mesenchymal stem cells (hMSC) adhered on microcarriers, are reputed sensitive to hydromechanical stresses arising from stirring. Many publications, especially using Computational Fluid Dynamics, characterize spatial fields of velocity and turbulence inside bioreactors but the exposure frequency to these stresses is never taken into account in the case of animal cell culture bioreactor description. To fill this gap, this study used both CFD Reynolds-Averaged and Large-Eddy Simulations to characterize the hydrodynamics inside 250 mL mini-bioreactors, which is a relevant volume for hMSC cultures. Five impeller geometries were studied. From the velocity and turbulence fields calculated, an energy dissipation/circulation function, related to both frequency and intensity of potentially damaging hydrodynamic events for the cells, was determined for various operating conditions. Based on the simulation results, the marine propeller operating in up-pumping mode seems to be the most adapted condition, since it exhibits a low frequency of exposure to an acceptable intensity of the turbulent dissipation rate. From a general point of view, the new methodology proposed should be used in the future to screen the most adapted bioreactor geometry to biological constraints. [less ▲]

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See detailLarge-pore membrane hemofiltration increases cytokine clearance and improves right ventricular-vascular coupling during endotoxic shock in pigs
Lambermont, Bernard ULg; Delanaye, Pierre ULg; Dogné, Jean-Michel ULg et al

in Artificial Organs (2006), 30(7), 560-564

Hemodynamic improvement in patients suffering from both septic shock and renal failure who received hemofiltration suggested that an extrarenal epuration technique could be of interest in patients with ... [more ▼]

Hemodynamic improvement in patients suffering from both septic shock and renal failure who received hemofiltration suggested that an extrarenal epuration technique could be of interest in patients with septic shock alone. However, most of the studies using continuous venovenous hemofiltration (CVVH) in this setting evidenced neither cytokine clearance nor significant reduction in their plasma level. Lack of significant clearance was explained in part by the small size of the membrane pores. Therefore, we investigated the effects of large-pore membrane hemofiltration (LPHF) during endotoxic shock in pigs on interleukin 6 (IL-6) and interleukin 10 (IL-10) clearances, and on right ventricular (RV)-vascular coupling. Thirteen anesthetized healthy pigs weighing 20-30 kg were divided into two groups. In the Endo group (n = 6), the pigs received a 0.5-mg/kg endotoxin infusion over a period of 30 mins from T0 to T30. In the EndoHF group (n = 7), LPHF (cutoff = 80 kDa) and an ultrafiltration rate of 45 mL/kg/h were started 30 mins after the end of the endotoxin infusion, from T60 to T240. In this model of porcine endotoxic shock, LPHF was responsible for a significant clearance of IL-6 (20 mL/min) and Il-10 (14 mL/min), and for an improvement in RV-vascular coupling. [less ▲]

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See detailLarge-scale alignments of quasar polarisations: a detailed study of the spinless-particle scenario
Payez, Alexandre ULg

Doctoral thesis (2013)

The main motivation for our work has been a puzzling observation concerning quasars. No one expected the existence of correlations in the polarisation of visible light coming from objects separated by ... [more ▼]

The main motivation for our work has been a puzzling observation concerning quasars. No one expected the existence of correlations in the polarisation of visible light coming from objects separated by gigaparsecs, until they were first reported in the form of a redshift-dependent effect that has become more and more significant with the growth of the data sample. In close connexion with the observational group, we have studied in detail the most widely considered scenario, involving axion-photon mixing in extragalactic magnetic fields. After a systematic investigation, we conclude that it is very unlikely that these observations can be accounted for by axion-like particles, given current data and constraints. We also derive new limits on the parameters describing these particles. This thesis gives in particular a detailed account of the consequences of axion-photon mixing on polarisation, studies the influence of averages over the frequency (including a wave-packet treatment of the mixing), and discusses the consequences of different magnetic-field morphologies. [less ▲]

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See detailLarge-scale alignments of quasar polarization vectors. Observational evidence and possible implications for cosmology and fundamental physics
Hutsemekers, Damien ULg

Scientific conference (2014, March 05)

Based on a sample of 355 quasars with significant optical linear polarization and using various statistical methods, we show that quasar polarization vectors are not randomly oriented over the sky with a ... [more ▼]

Based on a sample of 355 quasars with significant optical linear polarization and using various statistical methods, we show that quasar polarization vectors are not randomly oriented over the sky with a probability often in excess of 99.9%. The polarization vectors appear coherently aligned over huge regions of the sky (~1 Gpc), located at both low (z ~0.5) and high (z ~1.5) redshifts and characterized by different preferred directions of the polarization. These characteristics make the alignment effect difficult to explain in terms of contamination by instrumental or interstellar polarization in our Galaxy. We notice that the region of the sky where the alignments are prominent is not far from preferred directions tentatively identified in the Cosmic Microwave Background. Polarization alignments may thus reveal structures at scales beyond the homogeneity scale of concordance cosmology. Several interpretations are discussed. In particular, we show that the dichroism and birefringence predicted by photon pseudo-scalar oscillation along the line of sight cannot reproduce the observed properties of the alignments. Besides, accurate measurements of quasar circular polarization allow us to strongly constrain the parameter space of axion-like particles. [less ▲]

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See detailLarge-Scale Alignments of Quasar Polarization Vectors: Evidence at Cosmological Scales for Very Light Pseudoscalar Particles Mixing with Photons ?
Hutsemekers, Damien ULg; Payez, Alexandre ULg; Cabanac, R et al

in Bastien, Pierre (Ed.) Astronomical Polarimetry 2008: Science from Small to Large Telescopes. ASPC 449 (2011, November 01)

Based on a sample of 355 quasars with significant optical polarization, we found that quasar polarization vectors are not randomly oriented over the sky as naturally expected. The probability that the ... [more ▼]

Based on a sample of 355 quasars with significant optical polarization, we found that quasar polarization vectors are not randomly oriented over the sky as naturally expected. The probability that the observed distribution of polarization angles is due to chance is lower than 0.1%. The polarization vectors of the light from quasars are aligned although the sources span huge regions of the sky (˜ 1 Gpc). Groups of quasars located along similar lines of sight but at different redshifts (typically z ≍ 0.5 and z ≍ 1.5) are characterized by different preferred directions of polarization. These characteristics make the observed alignment effect difficult to explain in terms of a local contamination by interstellar polarization in our Galaxy. Interpreted in terms of a cosmological-size effect, we show that the dichroism and birefringence predicted by a mixing between photons and very light pseudoscalar particles within a magnetic field can qualitatively reproduce the observations. We find that circular polarization measurements could help constrain this mechanism. [less ▲]

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See detailLarge-scale Analysis of the human genome: from DNA sequence analysis to the modeling of replication in higher eukaryotes
Arneodo, Alain; d'Aubenton-Carafa, Y.; Audit, B. et al

in Proceeding of the 14th EUSIPCO (2006)

We explore large-scale nucleotide compositional fluctuations along the human genome through the optics of the wavelet transform mi- croscope. Analysis of the TA and GC skews reveals the existence of ... [more ▼]

We explore large-scale nucleotide compositional fluctuations along the human genome through the optics of the wavelet transform mi- croscope. Analysis of the TA and GC skews reveals the existence of strand asymmetries associated to transcription and/or replication The investigation of 14854 intron-containing genes shows that both skews display a characteristic step-like profile exhibiting sharp tran- sitions between transcribed (finite bias) and non-transcribed (zero bias) regions. As we observe for 7 out of 9 origins of replica- tion experimentally identified so far, the (AT+GC) skew exhibits rather sharp upward jumps, with a linear decreasing profile in be- tween two successive jumps. We describe a multi-scale method- ology that allows us to predict 1012 replication origins in the 22 human autosomal chromosomes. We present a model of replica- tion with well-positioned replication origins and random termina- tion sites that accounts for the observed characteristic serrated skew profiles. We emphasize these putative replication initiation zones as regions where the chromatin fiber is likely to be more open so that DNA be easily accessible. In the crowded environment of the cell nucleus, these intrinsic decondensed structural defects actually predisposes the fiber to spontaneously form rosette-like structures that provide an attractive description of genome organization into replication foci that are observed in interphase mammalian nuclei. [less ▲]

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See detailLarge-Scale Clinical Expansion of Mesenchymal Stem Cells in the GMP-Compliant, Closed Automated Quantum® Cell Expansion System: Comparison with Expansion in Traditional T-Flasks
LECHANTEUR, Chantal ULg; Baila, Stefano; Janssen, Michel Etienne et al

in Journal of Stem Cell Research & Therapy (2014), 4(8),

Objectives: Significant advances have been achieved regarding the knowledge of the immunoregulatory properties of mesenchymal stem cells (MSC). We are currently involved in several clinical protocols ... [more ▼]

Objectives: Significant advances have been achieved regarding the knowledge of the immunoregulatory properties of mesenchymal stem cells (MSC). We are currently involved in several clinical protocols evaluating these properties in different settings including hematopoietic cells or solid organ transplantation, and severe or refractory autoimmune disorders. Considering the large number of ex-vivo expanded cells required for these clinical protocols (MSC dose varies from 1 to 4x10-6 MSC/kg patient per infusion), we evaluated the Quantum® device, a GMPcompliant, functionally closed, automated hollow fiber bioreactor system and compared it with our traditional clinical culture system in flasks. Methods: Primary and pre-enriched MSC expansions were simultaneously conducted in both culture systems and evaluated in terms of expansion rates and compliance with quality specifications and ISCT-release criteria. Due to practical considerations, most of the experiments conducted in the bioreactor (P1 and P2 expansions) used thawed MSC. These were compared with both fresh and thawed MSC expansions in flasks. Results: The Quantum® device reproducibly produced therapeutic MSC doses that fulfill ISCT-release criteria, are sterile, devoid of mycoplasma and endotoxin, have normal karyotypes and demonstrate immunosuppressive and differentiation capacities in vitro. Cells also grew faster in the bioreactor than in flasks during passage P1 (doubling time 40 compared to 56 hours in flasks) and P2 expansions but not during the primary expansion phase (P0). Seeding 20x10-6 thawed P2-preselected cells on the device allowed us to harvest 110-276x10-6 MSC after a 7 day expansion; seeding 50x10-6 cells resulted in 291-334x10-6 MSC harvested. Conclusion: In conclusion, the Quantum® device is an excellent system to produce a clinical dose of MSC but cost-effectiveness varies as a function of the manufacturing strategy in place. For our particular situation, the use of the Quantum device didn't result in a cost saving solution. [less ▲]

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See detailLarge-scale coherent orientations of quasar polarisation vectors: interpretation in terms of axion-like particles
Payez, Alexandre ULg; Hutsemekers, Damien ULg; Cudell, Jean-René ULg

in AIP Conference Proceedings (2010), 1274,

The observation of redshift-dependent coherent orientations of quasar polarisation vectors over cosmological distances in some regions of the sky is reviewed. Based on a good-quality sample of 355 ... [more ▼]

The observation of redshift-dependent coherent orientations of quasar polarisation vectors over cosmological distances in some regions of the sky is reviewed. Based on a good-quality sample of 355 measured quasars, this observation seems to infer the existence of a new effect acting on light propagation on such huge distances. A solution in terms of nearly massless axion-like particles has been proposed in the literature and its current status is discussed. [less ▲]

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See detailLarge-scale eradication of rabies using recombinant vaccinia-rabies vaccine
Brochier, Bernard; Kieny, M. P.; Costy, F. et al

in Nature (1991), 354(19/26 December), 520-521

Detailed reference viewed: 40 (4 ULg)