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See detailComparison between new and old excipients
Hubert, Cédric ULg; Ziemons, Eric ULg; Hubert, Philippe ULg

Report (2011)

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See detailComparison between nonsteroidal and steroidal anti-inflammatory treatment in calf pasteurellosis model
Olaerts, J.; Van de Weerdt, M. L.; Lekeux, Pierre ULg

in Pflügers Archiv : European Journal of Physiology (1995), 430

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See detailComparison between Open and Closed Repair for Abdominal Aortic Aneurysms: A Word of Caution
Limet, Raymond ULg; CREEMERS, Etienne ULg

in Acta Chirurgica Belgica (2000), 100(1), 12-5

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See detailComparison between optical pulsed thermography and vibrothermography for the assessment of carbon fibers composite materials
Montrieux, Henri-Michel ULg; Demy, Philippe; Ibarra-Castanedo, Clemente et al

(2013, August 02)

Pulsed thermography and vibrothermography are two active thermography techniques characterized by different heating methods of the specimen. In pulsed phase thermography, a sample is heated by two flash ... [more ▼]

Pulsed thermography and vibrothermography are two active thermography techniques characterized by different heating methods of the specimen. In pulsed phase thermography, a sample is heated by two flash lamps for a short period to inject a Dirac impulse heat in the material. The cooling of the part is monitored with an infrared camera to detect thermal contrast in the image, characteristic of the presence of a defect. In vibrothermography, high frequency vibrations are injected into the sample causing an internal heating observed on surface right above the defect due to diverse phenomena as friction or viscoelastic hysteresis. If pulsed thermography is a well-known technique that has been integrated into the arsenal of industrial NDT methods, vibrothermography is a less common experimental method still subject to theoretical and practical investigations. This article aims to compare the effectiveness of the two methods in the case of different types of composites based on carbon fibers: carbon fiber reinforced plastic (CFRP) plates as well as a completely new material: carbon magnesium composite. [less ▲]

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See detailA Comparison between Optimal Allocations Based on the Modified VaR and on a Utility-Based Risk Measure
Bodson, Laurent ULg; Coën, Alain ULg; Hübner, Georges ULg

in Gregoriou, Greg N. (Ed.) The VaR Modeling Handbook: Practical Applications in Alternative Investing, Banking, Insurance, and Portfolio Management Book (2008)

Many empirical analyses have demonstrated that some financial asset returns like those of hedge funds depart from the normal distribution. From this observation, several new risk measures have been ... [more ▼]

Many empirical analyses have demonstrated that some financial asset returns like those of hedge funds depart from the normal distribution. From this observation, several new risk measures have been created to take into consideration the skewness and the kurtosis of the return distributions. We propose in this chapter to present the impact of higher moments on the optimal portfolio allocation comparing two four-moment risk measures, namely a utility-based risk measure with the preference-free modified VaR (MVaR). [less ▲]

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See detailA comparison between Optimal Allocations Based on the Modified VaR and those based on a Utility-Based Risk Measure
Bodson, Laurent ULg; Coën, Alain; Hübner, Georges ULg

in Gregoriou, Greg (Ed.) The VaR Modeling Handbook (2009)

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See detailComparison between Perkin-Elmer and Chromsytem Vitamin D kit on TQ 5500 from AB SCIEX
LE GOFF, Caroline ULg; PEETERS, Stéphanie ULg; CRINE, Yannick ULg et al

in Biochimica Clinica (2013, May), 37(SS), 471

Background: Twenty-five hydroxy-vitamin D (25(OH) D) determination is now routinely prescribed in the Laboratory. Recently, different new methods have been available for this determination. Among them ... [more ▼]

Background: Twenty-five hydroxy-vitamin D (25(OH) D) determination is now routinely prescribed in the Laboratory. Recently, different new methods have been available for this determination. Among them, LCMS/MS methods have emerged in some laboratories. However these methods are generally “home-brewed” and an important variability between them can be seen on different external quality controls, mainly due to a lack of standardization. Recently, Perkin-Elmer (PE) (Turku, Finland) and Chromsystem (CS) (Grafelfing, Germany) launched a standardised method for 25(OH )D determination on LCMS/MS. The aim of our study was to compare these methods on the AB SCIEX TQ5500 (Framingham, Massachusetts, USA) LCMS/MS to measure 25(OH) D3. Methods All the samples were treated according to our preanalyitical procedure: after sampling, they were spun at +4°c at 3500G, aliquoted and kept frozen at -20°c until determination. A method comparison was assessed with CS and PE for the measurement of the 25(OH)D3. We selected 110 remnant samples with 25(OH)D3 levels ranging from 1.6 to 136.7 ng/ml with the PE method to cover the range of usually values Slope and intercept were calculated using Passing and Bablock linear regression and we compared the methods with the Bland and Altman plots. Results For CS, the method is linear up to 250 µg/L, the LOQ is 3.6 µg/L, the intra-assay CV is < 5% and the inter-assay is < 7%. For PE, the method is linear up to 314 µg/L, the LOQ is 3.4 µg/L, the intra-assay CV is < 7.8% and the inter-assay is < 8.5%. On the whole range of measure (n=110), the regression equation is PE = 0.8521+0.9226 (CS) (95%CI of the intercept: (-0.0048;1.37) and 95% CI of the slope (0.89;0.95). The Bland and Altman plot does not show any bias between the two methods (mean difference CS-PE= -2.5 ng/ml) and the standard deviation of the mean is 3,98 ng/ml Conclusion: The performances of these methods are comparable on our new TQ 5500 from AB SCIEX. For now, there is no consensus on a “reference” method for vitamin D quantification. We notice only that the values obtained by CS are systematically a little bit lower than PE’s values, especially for results below 20 ng/ml. However, we have no clear explanation for such behaviour. [less ▲]

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See detailComparison between platelet-rich plasma (PRP) and vascular endothelial growth factor-111 (VEGF-111) as a therapeutic tool in tendon healing process
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent ULg et al

Poster (2010, March 20)

Introduction In spite of the availability of various treatments for tendinopathy, this pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Among them, the ... [more ▼]

Introduction In spite of the availability of various treatments for tendinopathy, this pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Among them, the injection of platelet-rich plasma (PRP) seems to be a promising one. Indeed, several animal models have demonstrated that injection of blood platelets can initiate and stimulate tendon and ligament repair by releasing growth factors (GF) locally. Among all the GF released by activated platelets, the vascular endothelial growth factor-A (VEGF-A) is known to induce positive effects on vascular function and angiogenesis, and could be implicated in the healing process of tendons. Recently, a novel VEGF-A isoform was identified, the VEGF-111, a biologically active and proteolysis-resistant VEGF-A isoform, also known to present beneficial effects on ischemic diseases. This prompted us to evaluate whether VEFF-111 would have a therapeutic interest within the framework of the tendon pathology. Aim of the study: We hypothesized that the healing of ruptured Achilles tendons, which is the last stage of the Blazina’s classification, could be improved by injection of VEGF-111 that was compared to the potential effect of PRP injections using a rat model. Methods: A 5mm defect was surgically induced in rat Achilles tendon after resection of plantaris tendon. Rats were divided into 3 groups: A: control (no injection), B: PRP treatment and C: VEGF-111 treatment. Rats received a local injection of PRP (50µL) or VEGF-111 (100ng) in situ after the surgery and were placed in their cage without immobilization. After 5, 15 and 30 days, the rats were euthanized in each group. The traumatized Achilles tendon of each rat was removed and dissected during the healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Results: Our results show that developed force necessary to induce tendon rupture during biomechanical tensile test was more important for tendons which had received an injection of PRP or VEGF-111. Moreover, the tensile force necessary to break tendons is higher with PRP than with VEGF-111. These results were already noticed from day 5 onwards. Conclusion: This experimentation has shown that both PRP and VEGF-111 injections stimulated tendon healing process as suggested by the increased force needed to break tendons during its healing process. Furthermore, this acceleration of the cicatrisation process was more significant with PRP than with VEGF-111. This could be explained by the release from platelets of a “cocktail” of growth factors acting in synergy on the healing process. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

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See detailComparison between player specialization, anthropometric characteristics and jumping ability in top-level volleybal players
Ciccarone, Guido; Croisier, Jean-Louis ULg; Fontani, G. et al

in Medicina dello Sport : Rivista di Fisiopatologia dello Sport (2008), 61

Aim. Volleyball is an open skill sport with predominant anaerobic alactic acid power. At higher skill levels, performance characteristics are mainly determined by speed and vertical jumping ability. The ... [more ▼]

Aim. Volleyball is an open skill sport with predominant anaerobic alactic acid power. At higher skill levels, performance characteristics are mainly determined by speed and vertical jumping ability. The aim of this study was to compare anthropometric parameters and jumping ability in a group of elite male volleyball players in relation to technical skills required by player position. Methods. The study population included 36 elite male volleyball players (coming from the Italian First and Second Division Championships). Subjects were grouped by playing position on the court: setters (7); blockers (10); hitters (16); liberos (3). Assessment included anthropometric parameters such as height, weight, body mass index (weight in kg/height in m2), indirect calculation of body fat mass by means of the Katch method (%BFM), measurement of reach with one hand (R1) and two hands (R2); and indirect measurement of explosive strength by means of the Bosco method: squat jump, countermovement jump (CMJ), CMJ with arm swing (CMJas), and repeated jumps for 15 s (R15”); measurement of motor coordination and jumping ability by means of the Vertec test combined with specific offense (Vertec attack [VA]) and defense (Vertec block [VB]) skills. Results. Significant differences were observed between player specialization and anthropometric parameters (height, weight, BMI, R1 and R2). Results of the Bosco (SJ, CMJ, CMJas) and Vertec tests (VA and VB) also differed significantly among the player groups. Conclusion. Functional assessment protocols that evaluate anthropometric characteristics and jumping ability by means of two different unrelated methods, confirming that the two measure different aspects of the same performance, provide more complete indications for selecting players, workload planning and monitoring of player development during training. [less ▲]

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See detailComparison between principal component analysis and independent component analysis in EEG modelling
Bugli, Céline; Lambert, Philippe ULg

in Biometrical Journal = Biometrische Zeitschrift (2007), 49

Principal Component Analysis (PCA) is a classical technique in statistical data analysis, feature extraction and data reduction, aiming at explaining observed signals as a linear combination of orthogonal ... [more ▼]

Principal Component Analysis (PCA) is a classical technique in statistical data analysis, feature extraction and data reduction, aiming at explaining observed signals as a linear combination of orthogonal principal components. Independent Component Analysis (ICA) is a technique of array processing and data analysis, aiming at recovering unobserved signals or ‘sources’ from observed mixtures, exploiting only the assumption of mutual independence between the signals. The separation of the sources by ICA has great potential in applications such as the separation of sound signals (like voices mixed in simultaneous multiple records, for example), in telecommunication or in the treatment of medical signals. However, ICA is not yet often used by statisticians. In this paper, we shall present ICA in a statistical framework and compare this method with PCA for electroencephalograms (EEG) analysis.We shall see that ICA provides a more useful data representation than PCA, for instance, for the representation of a particular characteristic of the EEG named event-related potential (ERP). [less ▲]

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See detailComparison between Pulmonary Resistance and Penh in Anaesthetised Rats with Tracheal Diameter Reduction and after Carbachol Inhalation
Kirschvink, N.; Vincke, G.; Onclinx, C. et al

in Journal of Pharmacological & Toxicological Methods (2005), 51(2, Mar-Apr), 123-128

Introduction: Single-chambered barometric whole-body plethysmography is frequently used as a noninvasive lung function test. However, the validity of the enhanced Pause (Penh), an index of airflow ... [more ▼]

Introduction: Single-chambered barometric whole-body plethysmography is frequently used as a noninvasive lung function test. However, the validity of the enhanced Pause (Penh), an index of airflow limitation, remains controversial. We compared Penh with pulmonary resistance (R(L)) to test whether Penh detects tracheal subobstruction and carbachol-induced airflow limitation in spontaneously breathing, anaesthetised rats. Methods: Fourteen male Sprague-Dawley rats underwent tracheal catheterisation, followed by measurements of R(L) and Penh. Six rats underwent tracheal subobstruction by the consecutive insertion into the lumen of the tracheal tube of two catheters of decreasing diameter. Eight rats received an inhaled saline challenge, followed by two noncumulative nebulizations of carbachol (1.25 mg/mL, 1 min). Results: In rats with tracheal calibre reductions, R(L) significantly increased at each reduction (0.218+/-0.052 vs. 0.417+/-0.058 vs. 0.820+/-0.258 cm H(2)O/mL s, p<0.05), whereas Penh only increased after the last reduction (1.88+/-0.25 vs. 2.47+/-0.26, p<0.05). Increases (Delta) of R(L) and Penh were not correlated. In comparison to postsaline values, carbachol induced a significant increase of Penh (1.93+/-0.44 vs. 4.05+/-1.45, p<0.005) and R(L) (0.137+/-0.04 vs. 0.284+/-0.084 cm H(2)O/mL.s, p<0.005). DeltaPenh and DeltaR(L) were significantly correlated (r=0.80, p<0.05). Discussion: This study showed, by comparing Penh with R(L), that single-chambered plethysmography measuring Penh allows to detect carbachol-induced airflow limitation in spontaneously breathing, anaesthetised Sprague-Dawley rats, but poorly detects an increase in R(L) due to tracheal calibre reductions. These findings suggest that Penh might be only be used as an index of airflow limitation under well-defined experimental conditions. [less ▲]

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See detailA comparison between pulse contour analysis and Doppler echocardiographic measurements of cardiac output in awake horses
Guidi, E; Amory, Hélène ULg; Borde, Laura ULg et al

in In Proceedings of the 3rd Annual Congress of the European College of Equine Internal Medicine (ECEIM) (2009)

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See detailComparison between Radioactive Aerosol, Technegas and Krypton for Ventilation Imaging in Healthy Calves
Coghe, Joost; Votion, Dominique ULg; Lekeux, Pierre ULg

in Veterinary Journal (2000), 160(1), 25-32

The use of lung scintigraphy in calves necessitates the validation of a ventilation (V) imaging agent compatible with clinical applications. This study aimed at defining the value of an inhaled ... [more ▼]

The use of lung scintigraphy in calves necessitates the validation of a ventilation (V) imaging agent compatible with clinical applications. This study aimed at defining the value of an inhaled radioactive aerosol (99mTc-DTPA) and a 'pseudogas' (Technegas) in the assessment of regional V in healthy conscious calves by comparing 99mTc-DTPA and Technegas deposition (D) images to V(V) images obtained from the steady-state inhalation of the short half-life krypton 81 (81mKr) gas. Images were compared by analysis of radioactivity distribution in computer-generated regions of interest within the right lung and D to V ratio images were generated in order to highlight areas of mismatching between 99mTc-DTPA or Technegas and 81mKr distributions. Results of this analysis showed that the 99mTc-DTPA aerosol droplets were unable to reach the lung parenchyma because of significant particle impaction in the major conducting airways. Better definition of the ventilated lung was obtained when using Technegas because of minimal deposition in conducting airways. Furthermore, the Technegas and 81mKr distribution patterns were highly equivalent. [less ▲]

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See detailComparison between satellite and in situ sea surface temperature data in the Western Mediterranean Sea
Alvera Azcarate, Aïda ULg; Troupin, Charles ULg; Barth, Alexander ULg et al

in Ocean Dynamics (2011), 61(6), 767-778

A comparison between in situ and satellite sea surface temperature (SST) is presented for the western Mediterranean Sea during 1999. Several international databases are used to extract in situ data (World ... [more ▼]

A comparison between in situ and satellite sea surface temperature (SST) is presented for the western Mediterranean Sea during 1999. Several international databases are used to extract in situ data (World Ocean Database (WOD), MEDAR/Medatlas, Coriolis Data Center, International Council for the Exploration of the Sea (ICES) and International Comprehensive Ocean-Atmosphere Data Set (ICOADS)). The in situ data are classified into different platforms or sensors (CTD, XBT, drifters, bottles, ships), in order to assess the relative accuracy of these type of data respect to AVHRR (Advanced Very High Resolution Radiometer) SST satellite data. It is shown that the results of the error assessment vary with the sensor type, the depth of the in situ measurements, and the database used. Ship data are the most heterogeneous data set, and therefore present the largest differences with respect to in situ data. A cold bias is detected in drifter data. The differences between satellite and in situ data are not normally distributed. However, several analysis techniques, as merging and data assimilation, usually require Gaussian-distributed errors. The statistics obtained during this study will be used in future work to merge the in situ and satellite data sets into one unique estimation of the SST. [less ▲]

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See detailComparison between single-beat and multiple-beat methods for estimation of right ventricular contractility.
Lambermont, Bernard ULg; Segers, Patrick; Ghuysen, Alexandre ULg et al

in Critical Care Medicine (2004), 32(9), 1886-90

OBJECTIVE: It was investigated whether pharmacologically induced changes in right ventricular contractility can be detected by a so-called "single-beat" method that does not require preload reduction ... [more ▼]

OBJECTIVE: It was investigated whether pharmacologically induced changes in right ventricular contractility can be detected by a so-called "single-beat" method that does not require preload reduction. DESIGN: Prospective animal research. SETTING: Laboratory at a large university medical center. SUBJECTS: Eight anesthetized pigs. INTERVENTIONS: End-systolic elastance values obtained by a recently proposed single-beat method (Eessb) were compared with those obtained using the reference multiple-beat method (Eesmb). MEASUREMENTS AND MAIN RESULTS: Administration of dobutamine increased Eesmb from 1.6 +/- 0.3 to 3.8 +/- 0.5 mm Hg/mL (p =.001), whereas there was only a trend toward an increase in Eessb from 1.5 +/- 0.2 to 1.7 +/- 0.4 mm Hg/mL. Esmolol decreased Eesmb from 1.7 +/- 0.3 to 1.1 +/- 0.2 mm Hg/mL (p =.006), whereas there was only a trend for a decrease in Eessb from 1.5 +/- 0.2 to 1.3 +/- 0.1. CONCLUSIONS: The present method using single-beat estimation to assess right ventricular contractility does not work as expected, since it failed to detect either increases or decreases in right ventricular contractility induced by pharmacologic interventions. [less ▲]

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See detailComparison between Solution-Phase Stability and Gas-Phase Kinetic Stability of Oligodeoxynucleotide Duplexes
Gabelica, Valérie ULg; De Pauw, Edwin ULg

in Journal of Mass Spectrometry [=JMS] (2001), 36(4), 397-402

The relative kinetic stabilities of different 16-mer oligonucleotide duplexes were investigated by source collision-induced dissociation (CID) in a heated capillary electrospray ion source. They were ... [more ▼]

The relative kinetic stabilities of different 16-mer oligonucleotide duplexes were investigated by source collision-induced dissociation (CID) in a heated capillary electrospray ion source. They were compared with the relative stabilities in solution obtained by thermal denaturation monitored by UV spectrophotometry. The results clearly show that both hydrogen bonding and base stacking interactions that are present in solution are maintained in the gas phase. This suggests that the electrospray process preserves the double-helix structure of DNA. A step by step opening of the double helix structure is proposed for the gas-phase dissociation, competing with the covalent bond cleavage of bases. We also draw attention to the fact that by source CID, it is the kinetic stability of the complexes that is probed. In particular, this implies that only complexes of the same size can be compared. [less ▲]

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See detailA comparison between subjective and objective methods for evaluating the vocal accuracy of a popular song
Larrouy, Pauline ULg; Lévêque, Yohana; Giovanni, Antoine et al

Poster (2012, July 25)

Vocal accuracy of a sung performance can be evaluated by two methods: acoustical analyses and subjective judgements. For one decade, acoustic analyses have been presented as a more reliable solution to ... [more ▼]

Vocal accuracy of a sung performance can be evaluated by two methods: acoustical analyses and subjective judgements. For one decade, acoustic analyses have been presented as a more reliable solution to evaluate vocal accuracy, avoiding the limitation of experts’ perceptive system and their variability. This paper presents for the first time a direct comparison of these methods. 166 occasional singers were asked to sing the popular song « Happy Birthday ». Acoustic analyses were performed to quantify the pitch interval deviation, the number of contour errors and the number of tonality modulations for each recording. Additionally, eighteen experts in singing voice or music rated the global pitch accuracy of these performances. The results showed a high inter-rater concordance within the judges. In addition, a high correlation occurred between acoustic measurements and subjective rating. The total model of acoustic analyses explained 81% of the variance of the judges’ scores. Their rating was influenced by both tonality modulations and interval deviations. This study highlights the congruence between objective and subjective measurements of vocal accuracy while the assessment is done by music or singing voice experts. Our results confirm the relevance of the “pitch interval deviation” criterion in vocal accuracy assessment. Furthermore, the “number of tonality modulations” is a salient criterion in perceptive rating and should be taken into account in studies using acoustical analyses. [less ▲]

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See detailComparison between swabbing and destructive methods for microbiological pig carcass sampling.
Ghafir, Yasmine; Daube, Georges ULg

in Letters in Applied Microbiology (2008), 47

Aims: To compare the Belgian swabbing sampling method for pig carcasses with the reference destructive method with regard to Escherichia coli and aerobic plate counts, Salmonella and Campylobacter ... [more ▼]

Aims: To compare the Belgian swabbing sampling method for pig carcasses with the reference destructive method with regard to Escherichia coli and aerobic plate counts, Salmonella and Campylobacter prevalence and their relationship. Methods and Results: Recovery was significantly lower for the swabbing method and corresponded to a recovery of 36% for E. coli counts and 81% for aerobic plate counts in comparison with the destructive method. There was no significant difference between the swabbing and destructive sampling methods for the prevalence of Salmonella or Campylobacter. A higher median for E. coli counts was detected for samples where Salmonella or Campylobacter were detected. The same association was also observed between the median for aerobic plate counts and the presence of Campylobacter. Conclusions: The method of swabbing used, covering 600 cm2 on each half-pig carcass, is efficient for the sampling of pig carcasses in comparison with the reference destructive method. Significance and Impact of the Study: This study describes an efficient method for microbiological pig carcass sampling. The Belgian swabbing method should continue to be used to allow the follow up of bacterial contamination in the Belgian meat production chain. [less ▲]

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