Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailComparison of conjugation procedures for the preparation of monoclonal antibody-enzyme conjugates
Jeanson, Antoinette; Cloes, Jean-Michel; Bouchet, Mireille et al

in Journal of Immunological Methods (1988), 111(2), 261-270

Four monoclonal antibodies belonging to different subclasses and with differing isoelectric points were coupled to horseradish peroxidase (HRP) and alkaline phosphatase (AP) using various conjugation ... [more ▼]

Four monoclonal antibodies belonging to different subclasses and with differing isoelectric points were coupled to horseradish peroxidase (HRP) and alkaline phosphatase (AP) using various conjugation procedures. The conjugates were tested by enzyme immunoassay and their efficiency was characterized by the antibody and enzyme concentrations needed to obtain an arbitrary OD value. The suitability of antibody for conjugation through NH2 groups was tested by fluorodinitrobenzene (FDNB). HRP conjugates were produced by two variants of the sodium periodate procedure and two variants of the glutaraldehyde method, as well as by the heterobifunctional linker N-succinimidyl 3-(2-pyridyldithio)pro-pionate (SPDP). Two of the four antibodies were coupled by a third variant of the periodate method, through their carbohydrate moieties. The periodate-mediated conjugations, using sugar moieties on the enzyme, provided the most efficient HRP conjugates, regardless of the antibody subclass or isoelectric point. The glutaraldehyde procedures consistently gave the worst results. AP conjugates were prepared using the same methods. The most efficient and reproducible AP conjugates with all four monoclonal antibodies were obtained using the SPDP procedure. The efficiency of the other methods differed from one antibody to another. [less ▲]

Detailed reference viewed: 36 (0 ULg)
Full Text
See detailComparison of continuous background in-situ and column integrated CO2 observations at Jungfraujoch with an urban site in the city of Bern
Schibig, Michael; Leuenberger, Markus; Nyfeler, Peter et al

in Geophysical Research Abstracts (2014), 16

A six and a half year (January 2005 to May 2011) comparison of CO2 concentration observations has been performed at Jungfraujoch, Switzerland and the city of Bern using two different measurement ... [more ▼]

A six and a half year (January 2005 to May 2011) comparison of CO2 concentration observations has been performed at Jungfraujoch, Switzerland and the city of Bern using two different measurement techniques run by the University of Bern (UBE) and the University of Liege (UL). The UBE systems at Jungfraujoch and Bern are both combined systems for atmospheric oxygen and CO2 measurements. The cryogenically dried air is analysed for CO2 with a Maihak analyser based on the broad-band infrared absorption technique. The measurement frequency is every second but the final reported data are averages of six minute periods. UL is measuring the solar infrared spectrum since 1950 at Jungfraujoch. On its way through the atmosphere, the solar spectrum is modulated depending on the abundant gas species and their amount in the column. Since some gases like CO2 absorb the solar infrared radiation at particular wavelengths and the extinction is proportional to the gas concentration, it is possible to determine the gas concentration in the column above the sensor. At the conference, we will present the three observational records for the six and a half year period. The results show for all three records a distinct, but different seasonality. The seasonalities of the UL and UBE record at Jungfraujoch are lower than the seasonality in the city of Bern, i.e. 4.5 ppm per year and 9 ppm per year for the column and the in- situ record respectively, whereas the seasonality in the city of Bern is 31 ppm per year. Also the maxima and minima of the Jungfraujoch measurements are delayed by several weeks compared to the measurements in the city of Bern. The annual increase of the CO2 concentration of the UBE and UL records of Jungfraujoch are in good agreement with 1.94 ppm per year and 1.90 ppm per year, respectively. The annual increase of the CO2 concentration at the urban site is a bit higher at 2.01 ppm per year. [less ▲]

Detailed reference viewed: 14 (2 ULg)
Full Text
Peer Reviewed
See detailA Comparison of Contrast and Sensitivity in Tc-99m Thyroid Scintigraphy between Nine Nuclear Medicine Centres of a geographic area
Seret, Alain ULg

in Alasbimn Journal (2006), 32

Purpose: To compare with Picker’s thyroid phantom the contrast and the sensitivity obtained with ten cameras used for Tc-99m thyroid scintigraphy in a geographic area. Methods: The phantom image was ... [more ▼]

Purpose: To compare with Picker’s thyroid phantom the contrast and the sensitivity obtained with ten cameras used for Tc-99m thyroid scintigraphy in a geographic area. Methods: The phantom image was acquired with the collimator and the acquisition parameters used in clinical practice. Contrast for the 12 mm hot (H12) and for the 9 and 12 mm cold (C9, C12) nodules was measured, as well as sensitivity (S in cp/MBq/s). Results: Measured minimum-maximum values were as follows. Pinhole cameras (6): S = 62-131; H12 = 0.66-0.77; C12 = 0.77-0.90; C9 = 0.59-0.76. Non-pinhole cameras (4): S = 55-85; H12 = 0.52-0.59; C12 = 0.62-0.75; C9 = 0.30-50. Conclusions: The pinhole collimators outclass the parallel hole ones in contrast. The sensitivity was the highest (S > 96) for five of the six pinhole collimators. As a direct consequence of this study, two centres decided to switch to pinhole collimator for thyroid scintigraphy. [less ▲]

Detailed reference viewed: 34 (2 ULg)
Full Text
Peer Reviewed
See detailComparison of contrast enhanced three dimensional echocardiography with MIBI gated SPECT for the evaluation of left ventricular function
Cosyns, Bernard; Haberman, David; Droogmans, Steven et al

in Cardiovascular Ultrasound (2009), 7

Detailed reference viewed: 32 (3 ULg)
Full Text
Peer Reviewed
See detaila comparison of control strategies applied to an existing ice-storage system
Lemort, Vincent ULg

(2005, April)

While ice storage systems are designed according to a defined strategy for warm day loads, it is interesting to consider other conventional control strategies for mid-season day loads. These different ... [more ▼]

While ice storage systems are designed according to a defined strategy for warm day loads, it is interesting to consider other conventional control strategies for mid-season day loads. These different control strategies, applied to an existing cooling plant, are compared in terms of operating costs and energy consumption. A simplified cooling plant model is built. The chillers, cooling towers, and the ice storage system are modeled as different systems connected together. A time stage equal to 15 minutes is considered to simulate the different control strategies. Existing technical constraints and set points are met. The operating costs of the cooling plant are evaluated by taking into account both the energy and the demand cost rate. In off-design conditions, savings of operating costs are made only if the storage tanks are fully discharged after being fully charged. In this case, ice storage systems reduce the operating costs of the cooling plant by shifting a significant fraction of on-peak energy consumption to off-peak periods and by reducing the on-peak demand. But at the same time, the introduction of an ice storage system in a cooling plant causes the electrical energy consumption to rise because the thermal efficiency of the chillers is reduced when working in ice formation mode. [less ▲]

Detailed reference viewed: 26 (10 ULg)
Full Text
Peer Reviewed
See detailComparison of control strategies for waste heat recovery Organic Rankine Cycle systems
Lemort, Vincent ULg; Zoughaib, Assaad; Quoilin, Sylvain ULg

(2011, October)

This paper investigates the control of waste heat recovery Organic Rankine Cycle systems. A dynamic simulation model of the system was developed under Modelica language. This model associates the sub ... [more ▼]

This paper investigates the control of waste heat recovery Organic Rankine Cycle systems. A dynamic simulation model of the system was developed under Modelica language. This model associates the sub-models of the different components of the system: the evaporator, a scroll expander, the condenser, the liquid receiver and the pump. Both the speeds of the expander and of the pump are controlled in order to adjust the evaporating pressure and maintain the superheat at the outlet of the evaporator. Two types of controllers were implemented: Proportional Integral (PI) and Model Predictive Control (MPC) controllers. The PI controller on the expander speed is able to adjust the evaporating pressure with a high accuracy. It is also shown that the MPC controller on the pump speed maintains the superheat close to the set point value with a much better performance than the PI controller. Hence, the use of a MPC controller allows decreasing the set point value on the superheat without any risk of feeding the expansion machine with liquid droplets. [less ▲]

Detailed reference viewed: 496 (14 ULg)
See detailComparison of copy-methods of computer-generated holograms in dichromated gelatin
Habraken, Serge ULg; Roose, Stéphane ULg

in Proceedings of HOLO 3 (1991, November 20)

Detailed reference viewed: 7 (2 ULg)
Full Text
Peer Reviewed
See detailComparison of corticosterone, cortisol, triglycerides, aspartateaminotransferase and uric acid plasma concentrations during a foie gras production period in male mule ducks (Anas platyrhynchos X Cairina moschata)
Flament, Aline; Delleur, Valéry ULg; Poulipoulis, Anastassios ULg et al

in British Poultry Science (2012), 53(4), 408-414

1 Corticosterone, cortisol, triglycerides, aspartate aminotransferase (AST) and uric acid (UA) plasma concentration were measured at 8 and 12 weeks of age, at slaughtering and 45 min after an ... [more ▼]

1 Corticosterone, cortisol, triglycerides, aspartate aminotransferase (AST) and uric acid (UA) plasma concentration were measured at 8 and 12 weeks of age, at slaughtering and 45 min after an adrenocorticotrophic hormone (ACTH) stimulation test (8 weeks of age) in twelve male mule ducks. 2 No significant increase of corticosterone was found during the force feeding period. 3 Comparison of corticosterone and cortisol levels indicates that cortisol can be considered as a reliable acute stress indicator in future routine examinations. 4 Triglycerides and AST plasma concentrations progressively increased from pre-force feeding period to slaughtering. 5 UA plasma concentrations also increased from the start at 8 weeks of age to mid-force feeding time but no difference was noticed between mid-force feeding period and slaughtering. [less ▲]

Detailed reference viewed: 51 (7 ULg)
Full Text
Peer Reviewed
See detailComparison of cross-field pitting in fresh, dried and charcoalified softwoods
Gerards, Thomas ULg; Damblon, Freddy ULg; Wauthoz, B. et al

in Iawa Journal (2007), 28(1), 49-60

Cross-field pitting is one of the most reliable characters for softwood identifi cation. During charcoalification, a range of severe qualitative and quantitative modifications may occur in cross-field ... [more ▼]

Cross-field pitting is one of the most reliable characters for softwood identifi cation. During charcoalification, a range of severe qualitative and quantitative modifications may occur in cross-field pitting. As most fossil or archaeological wood remains are preserved as charcoal (fusain), the question arises whether these modifications hamper the accurate identification of some taxa. This work is a systematic biometric study of a wide range of gymnosperm cross-field pitting after experimental charcoalification. We focused on the window-like, piceoid, taxodioid, cupressoid, araucarioid and podocarpoid cross-field pitting types. Our main results are the following: 1) Cross-field pits of wood specimens dried out before charcoalification are hidden by a thin closing wall; in this case, it is often impossible to discriminate between the various types of cross-field pitting. 2) Piceoid cross-field pitting becomes taxodioid-like after charcoalification. 3) Biometric study of charred softwood cross-field pitting dimensions shows that the ratios between height and width of pit aperture and border allow us to distinguish and characterise four types of pitting (window-like, piceoid, taxodioid, cupressoid + araucarioid + podocarpoid [= CAP]). The discrimination within the CAP type requires further investigation. [less ▲]

Detailed reference viewed: 92 (3 ULg)
Full Text
See detailComparison of Data Transfer Methods between Meshes in the Frame of the Arbitrary Lagrangian Eulerien Formalism
Bussetta, Philippe ULg; Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Proceedings of "Fifth International Conference on Advanced COmputationalMethods in ENgineering" (2011, November)

In nonlinear solid Mechanics, the Arbitrary Lagrangian Eulerian (ALE) formalism is a common way to avoid mesh distortion when very large deformations occur in the modelled process. Usually, the ALE ... [more ▼]

In nonlinear solid Mechanics, the Arbitrary Lagrangian Eulerian (ALE) formalism is a common way to avoid mesh distortion when very large deformations occur in the modelled process. Usually, the ALE resolution procedure is based on an “operator split”, the second part of which is a Data Transfer between two meshes sharing the same topology (same number of nodes and same number of element neighbours for each of them). Thanks to this interesting property, classical ALE transfer algorithms can bemuchmore optimised in terms of CPU time than the ones that are used in the frame of a complete remeshing. However, the resulting CPU-efficient transfer schemes suffer from two main drawbacks. The first one is a spurious crosswind diffusion coming from the corner fluxes that have been neglected. The second issue is the number of explicit transfer steps which may become very large when the element size decreases. In this paper, these classical ALE Data Transfer methods are compared to more general algorithms which do not make any assumption on the topology of both meshes. [less ▲]

Detailed reference viewed: 49 (8 ULg)
Full Text
See detailComparison of Data Transfer Methods between two different meshes
Bussetta, Philippe ULg; Ponthot, Jean-Philippe ULg

in Proceedings of "IV International Conference on Computational Methods for Coupled Problems in Science and Engineering" (2011, June)

Many problems solved with the finite element method require more than one mesh (i.e. one specific mesh for each Physic or a remeshing is needed). The Data Transfer Method used, has a great importance in ... [more ▼]

Many problems solved with the finite element method require more than one mesh (i.e. one specific mesh for each Physic or a remeshing is needed). The Data Transfer Method used, has a great importance in the capacity to solve the problem and in the reliability of the solution. In general, the data is composed of two kinds of fields (defined thanks to the nodal values or at the integration points). In this paper, the more used Data Transfer Method is compared with the Data Transfer Methods based on a Weak Form (using Mortar Element or Finite Volume). [less ▲]

Detailed reference viewed: 71 (9 ULg)
Peer Reviewed
See detailComparison of deposition images obtained by use of an ultrafine 99m-technetium-labeled carbon dry aerosol with ventilation images obtained by use of 81m-krypton gas for evaluation of pulmonary dysfunction in calves.
Votion, Dominique ULg; Coghe, J. D.; Lekeux, Pierre ULg

in American Journal of Veterinary Research (2001), 62(12), 1881-6

OBJECTIVE: To characterize the accuracy of an ultrafine 99m-technetium-labeled carbon dry aerosol for use in assessment of regional ventilation in calves with pulmonary dysfunction. ANIMALS: 7 Belgian ... [more ▼]

OBJECTIVE: To characterize the accuracy of an ultrafine 99m-technetium-labeled carbon dry aerosol for use in assessment of regional ventilation in calves with pulmonary dysfunction. ANIMALS: 7 Belgian White and Blue calves. PROCEDURE: The ultrafine aerosol was assessed by comparing deposition (D) images with ventilation (V) images obtained by use of 81 m-krypton (81mKr) gas via D-to-V ratio (D:V) image analysis in calves during spontaneous breathing (SB) and during experimentally induced pulmonary dysfunction (ePD). RESULTS: Mismatching index (LrTot) calculated on the D:V images revealed a good match (LrTot, 0.96 +/- 0.01) between D and V distribution patterns in calves during SB. Calculation of the ultrafine aerosol penetration index relative to 81mKr (PIRel) revealed preferential distribution of the ultrafine aerosol in lung parenchyma (PIRel, 1.13 +/- 0.11). In ePD, heterogeneity in the D:V distribution was observed (LrTot, 0.78 +/- 0.10) as a result of ultrafine aerosol particles impaction in airways as indicated by PIRel (0.66 +/- 0.16) and a proportion of pixels more radioactive in D images, compared with V images, that was located in the central part of the lung (475 +/- 77% in ePD vs 32.8 +/- 5.7% in SB). However, this central deposition did not prevent visual examination of the entire ventilated lung. CONCLUSIONS AND CLINICAL RELEVANCE: The ultrafine aerosol appears suitable for use in examination of ventilated parts of lungs of cattle, even those with impaired pulmonary function. However, airway impaction of ultrafine aerosol particles impedes the quantification of regional ventilation in cattle with abnormal lung function. [less ▲]

Detailed reference viewed: 35 (6 ULg)
Full Text
Peer Reviewed
See detailComparison of Destructive Methods to Appraise the Mechanical Integrity of a Concrete Surface
Courard, Luc ULg; Bissonnette, Benoît; Vaysburd, Alex et al

in Concrete Repair Bulletin (2012), 25(4), 22-30

Depending on the technique being used, the concrete removal operation prior to repair can be harmful to the residual concrete skin left on the structure. Whenever a tight bond between the repair and the ... [more ▼]

Depending on the technique being used, the concrete removal operation prior to repair can be harmful to the residual concrete skin left on the structure. Whenever a tight bond between the repair and the old concrete is required, the soundness of the prepared surface should thus be assessed. Although this is widely recognized, there is no standard method intended to characterize the integrity of a concrete substrate after concrete removal. This paper presents the results of an investigation intended to assess and compare quantitatively different test methods, namely the Schmidt rebound hammer, the pull-out test and the pull-off test, to evaluate superficial mechanical integrity of a substrate after concrete removal operations. Although it does not yield a precise evaluation of compressive strength, the Schmidt rebound hammer test is recognized as a useful tool for performing quick surveys to assess concrete uniformity. The pull-off test is very well correlated with the splitting-tensile test, but it is not suited for vertical and overhead surfaces. The Capo pull-out test has limited interest for surface preparation, as it is applicable to flat surfaces only. Conversely, the accelerated pull-out test showed interesting potential as a simple and relatively rapid means for assessing the mechanical integrity of a concrete surface prior to repair for any type of concrete surface. More work is definitely required to refine the procedures and develop performance criteria. Nevertheless, it appears from the results generated in this study that the combination Schmidt hammer / pull-off test could fill the needs for the evaluation of horizontal surfaces after concrete removal, while the combination Schmidt hammer / accelerated pull-out test could be used effectively on vertical and overhead surfaces. [less ▲]

Detailed reference viewed: 74 (5 ULg)
Full Text
Peer Reviewed
See detailA comparison of diagnosis of pregnancy in the goat via transrectal ultrasound scanning, progesterone, and pregnancy-associated glycoprotein assays
Gonzalez, Fernando; Cabrera, F.; Batista, M. et al

in Theriogenology (2004), 62(6), 1108-1115

Real-time ultrasound scanning (US) via the transrectal route, progesterone (P4) assay, and pregnancy-associated glycoprotein (PAG) detection can be used to diagnose pregnancy at around 3 weeks after ... [more ▼]

Real-time ultrasound scanning (US) via the transrectal route, progesterone (P4) assay, and pregnancy-associated glycoprotein (PAG) detection can be used to diagnose pregnancy at around 3 weeks after breeding. Although several studies have been carried out to evaluate each of these different methods individually, it is difficult to establish adequate comparisons due to differences, such as the breed of goat, age, and farming conditions, among others. The aim of the present paper is to compare the accuracy of diagnosis of pregnancy using transrectal US, P4 assay and PAG detection at the same time and on the same animals. Canary dairy goats (n = 143) were synchronized with an 11-day fluorogestone acetate (FGA) intravaginal sponge followed by PGF(2 alpha), and eCG 2 days before the FGA withdrawal. Blood samples were collected on Days 20, 22, 24, and 26 after mating to determine P4 and PAG concentrations. Transrectal US examinations were performed at the same time. There were 79 pregnant goats and another 64 non-pregnant. The US via the transrectal method and the determination of PAG concentrations provide very accurate pregnancy diagnosis at 24-26 days after breeding; on the contrary, P4 assay on plasma samples performed on Day 22 after breeding was accurate, in this case, in detecting pregnant animals but did not always detect the non-pregnant does. [less ▲]

Detailed reference viewed: 52 (2 ULg)
Full Text
Peer Reviewed
See detailComparison of different approaches to evaluate External Quality Assessment Data.
Coucke, Wim; China, Bernard; Delattre, Isabelle et al

in Clinica Chimica Acta (2012), 413(5-6), 582-6

In EQA programs, Z-scores are used to evaluate laboratory performance. They should indicate poorly performing laboratories, regardless of the presence of outliers. For this, two different types of ... [more ▼]

In EQA programs, Z-scores are used to evaluate laboratory performance. They should indicate poorly performing laboratories, regardless of the presence of outliers. For this, two different types of approaches exist. The first type are "outlier-based" approaches, which first exclude outlying values, calculate the average and standard deviation on the remaining data and obtain Z-scores for all values (e.g., Grubbs and Dixon). The second type includes the "robust" approaches (e.g., Tukey and Qn or the algorithm recommended by ISO). The different approaches were assessed by randomly generated samples from the Normal and Student t distributions. Part of the sample data were contaminated with outliers. The number of false and true outliers was recorded and subsequently, Positive and Negative Predictive Values were derived. Also, the sampling mean and variability were calculated for location and scale estimators. The various approaches performed similarly for sample sizes above 10 and when outliers were at good distance from the centre. For smaller sample sizes and closer outliers, however, the approaches performed quite differently. Tukey's method was characterised by a high true and a high false outlier rate, while the ISO and Qn approaches demonstrated weak performance. Grubbs test yielded overall the best results. [less ▲]

Detailed reference viewed: 11 (1 ULg)
Full Text
Peer Reviewed
See detailComparison of different impulse response measurement techniques
Stan, Guy-Bart; Embrechts, Jean-Jacques ULg; Archambeau, Dominique

in Journal of the Audio Engineering Society (2002), 50(4), 249-262

The impulse response of an acoustical space or transducer is one of its most important characterizations. In order to perform the measurement of their impulse responses, four of the most suitable methods ... [more ▼]

The impulse response of an acoustical space or transducer is one of its most important characterizations. In order to perform the measurement of their impulse responses, four of the most suitable methods are compared: MLS (maximum-length sequence), IRS (inverse repeated sequence), time-stretched pulses, and SineSweep. These methods have already been described in the literature. Nevertheless, the choice of one of them depending on the measurement conditions is critical. Therefore an extensive comparison has been realized. This comparison was done through the implementation and realization of a complete, fast, reliable, and cheap measurement system. Finally, a conclusion for the use of each method according to the principal measurement conditions is presented. It is shown that in the presence of nonwhite noise, the MLS and IRS techniques seem to be more accurate. On the contrary, in quiet environments the logarithmic SineSweep method seems to be the most appropriate. [less ▲]

Detailed reference viewed: 549 (8 ULg)