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See detailRelevance of using a human microarray to study gene expression in heaves-affected horses.
Ramery, Eve ULg; Closset, Rodrigue; Bureau, Fabrice ULg et al

in Veterinary Journal (2008), 177(2), 216-221

Environmental causes of heaves are well described, but the molecular mechanisms of the disease remain unclear. Previous studies have highlighted the implications of variations in gene expression, most ... [more ▼]

Environmental causes of heaves are well described, but the molecular mechanisms of the disease remain unclear. Previous studies have highlighted the implications of variations in gene expression, most using reverse transcription polymerase chain reaction (RT-PCR). This well-known technique limits the number of genes that can be studied in a single assay. Microarray appears to be a valuable tool to by-pass this limitation, but so far there has been no equine-specific microarray available on the market. The present study was performed to determine whether a human microarray could be used to study gene expression in nucleated cells originating from peripheral blood and bronchoalveolar lavage fluid (BALF) in heaves-affected horses. With a four-fold cut-off, a total of 46 candidates were identified with differentially regulated genes between heaves-affected horses and controls. A real-time quantitative RT-PCR (RT-QPCR) conducted on a selection of genes, determined on the basis of previous publications, was used to validate the microarray results. The microarray failed to detect the presence of interleukin (IL)-1beta and IL-8 mRNA in the nucleated cells from BALF otherwise confirmed by real-time RT-QPCR. Although some candidate genes have been identified using this method, a complete expression profile of genes related to heaves could not be obtained with the use of the human microarray. [less ▲]

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See detail"Relevance vector machine" consciousness classifier applied to cerebral metabolism of vegetative and locked-in patients.
Phillips, Christophe ULg; Bruno, Marie-Aurélie ULg; Maquet, Pierre ULg et al

in NeuroImage (2011), 56(2), 797808

The vegetative state is a devastating condition where patients awaken from their coma (i.e., open their eyes) but fail to show any behavioural sign of conscious awareness. Locked-in syndrome patients also ... [more ▼]

The vegetative state is a devastating condition where patients awaken from their coma (i.e., open their eyes) but fail to show any behavioural sign of conscious awareness. Locked-in syndrome patients also awaken from their coma and are unable to show any motor response to command (except for small eye movements or blinks) but recover full conscious awareness of self and environment. Bedside evaluation of residual cognitive function in coma survivors often is difficult because motor responses may be very limited or inconsistent. We here aimed to disentangle vegetative from "locked-in" patients by an automatic procedure based on machine learning using fluorodeoxyglucose PET data obtained in 37 healthy controls and in 13 patients in a vegetative state. Next, the trained machine was tested on brain scans obtained in 8 patients with locked-in syndrome. We used a sparse probabilistic Bayesian learning framework called "relevance vector machine" (RVM) to classify the scans. The trained RVM classifier, applied on an input scan, returns a probability value (p-value) of being in one class or the other, here being "conscious" or not. Training on the control and vegetative state groups was assessed with a leave-one-out cross-validation procedure, leading to 100% classification accuracy. When applied on the locked-in patients, all scans were classified as "conscious" with a mean p-value of .95 (min .85). In conclusion, even with this relatively limited data set, we could train a classifier distinguishing between normal consciousness (i.e., wakeful conscious awareness) and the vegetative state (i.e., wakeful unawareness). Cross-validation also indicated that the clinical classification and the one predicted by the automatic RVM classifier were in accordance. Moreover, when applied on a third group of "locked-in" consciously aware patients, they all had a strong probability of being similar to the normal controls, as expected. Therefore, RVM classification of cerebral metabolic images obtained in coma survivors could become a useful tool for the automated PET-based diagnosis of altered states of consciousness. [less ▲]

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See detailRelevant radiological anatomy of the pig as a training model in interventional radiology
Dondelinger, R. F.; Ghysels, M. P.; Brisbois, D. et al

in European Journal of Radiology (1998), 8

The use of swine for teaching purposes in medicine and surgery has largely increased in recent years. Detailed knowledge of the porcine anatomy and physiology is a prerequisite for proper use of pigs as a ... [more ▼]

The use of swine for teaching purposes in medicine and surgery has largely increased in recent years. Detailed knowledge of the porcine anatomy and physiology is a prerequisite for proper use of pigs as a teaching or an experimental model in interventional radiology. A systematic study of the radiological anatomy was undertaken in more than 100 female pigs aged 6-8 weeks. All studies were performed under general anesthesia in a single session. Animals were sacrificed at the end of the study. Selective angiographies were systematically obtained in all anatomical territories. In other animals CT and MRI examinations were performed and were correlated to anatomical sections and acrylic casts of the vascular structures. Endoscopical examinations of the upper gastrointestinal tract, including retrograde opacification of the biliary and pancreatic ducts, were added in selected animals. The main angiographic aspects of the brain, head and neck, thorax, abdomen, and pelvis were recorded. Similarities and differences in comparison with human anatomy are stressed. Potential applications in interventional radiology are indicated. [less ▲]

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See detailRelever les défis environnementaux pour les filières cotonnières
Abou Abba,, A.; Hofs, Jean-Luc; Mergeai, Guy ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2006)

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See detailRELIABILITY ACCELERATED TESTING OF MEMS ACCCELEROMETERS
Bazu, Marius; Gălăţeanu, Lucian; Ilian, Virgil Emil et al

in IEEE Sensors Journal (2007), 1

An attempt to assess the reliability of a batch of MEMS accelerometers is presented. The testing plan is application oriented and contains combined tests: thermal and mechanical stresses (two variants ... [more ▼]

An attempt to assess the reliability of a batch of MEMS accelerometers is presented. The testing plan is application oriented and contains combined tests: thermal and mechanical stresses (two variants: vibration and tilting) were used. The results demonstrated the good reliability of the tested device, the failure rate being smaller than 6.10-8h-1. [less ▲]

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See detailReliability and validity of a new French-language triage algorithm : the ELISA scale
JOBE, Jérôme ULg; Ghuysen, Alexandre ULg; GERARD, P et al

in Emergency Medicine Journal (2014), 31(2), 115-20

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See detailReliability and validity of a new french-language triage algorithm : the ELISA scale
JOBE, Jérôme ULg; Ghuysen, Alexandre ULg; GERARD, Paul et al

in Emergency Medicine Journal (2012)

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See detailReliability and validity of the Quality of Life Systemic Inventory for Children (QLSI-C): Preliminary result of a modular assessment tool of quality of life using e-Health technologies
Toucheque, Malorie ULg; Etienne, Anne-Marie ULg

Poster (2014, March)

Objective: Use of generic versus specific tools in psychological assessment is a controversial issue. Generic instruments can be used to measure QOL for numerous chronic illnesses; however, they may not ... [more ▼]

Objective: Use of generic versus specific tools in psychological assessment is a controversial issue. Generic instruments can be used to measure QOL for numerous chronic illnesses; however, they may not be sensitive to particular aspects of the disease. Unfortunately, disease-specific measures cannot be used to compare results across diseases or conditions. The QLSI-C is an assessment tool that uses a modular approach developed to overcome these shortcomings. QLSI-C was devised as a generic scale to be integrated with disease specific modules. The purpose of this study is to report on reliability and validity of the QLSI-C generic scale and the cystic fibrosis (CF)-specific module. Methods: QLSI-C was administered to 20 children with CF and 20 healthy children (ages 8-12 years) in Belgium. Internal consistency was assessed using Cronbach’s coefficient. Validity of the QLSI-C was measured using the known-groups method, i.e., analysis of variance (ANOVA) to distinguish between healthy children and children with CF. To examine the validity of the QLSI-C, correlations were calculated between the generic scale and CF-specific module. Results: Internal consistency for the QLSI-C generic scale with the CF-specific module was good ( =.82). ANOVA results revealed a significant difference between CF and healthy children for the QOL score (p=.005), with higher average scores (i.e., lower QoL) for CF children (M=4.35) than healthy children (M=1.25). Correlations between QoL scores on the generic scale and CF-specific module demonstrated medium effect size (r=0.47; p=.04). Conclusions: To date, three specific modules are available for the QLSI-C: (1) cancer; (2) asthma; (3) cystic fibrosis. Originality of this tool is strengthened by use of e-Health technologies (i.e., iPad app for administering the QLSI-C). Satisfactory psychometric properties and state-of-the-art use of technology suggests that the QLSI-C has potential utility for use in clinical trials, research, and clinical practice. [less ▲]

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See detailRELIABILITY OF ANALYTICAL METHODS’ RESULTS: A BAYESIAN APPROACH TO ANALYTICAL METHOD VALIDATION
Rozet, Eric ULg; Govaerts, B.; Lebrun, Pierre ULg et al

Conference (2012, March)

Methods validation is mandatory in order to assess the fitness of purpose of the developed analytical method. Of core importance at the end of the validation is the evaluation of the reliability of the ... [more ▼]

Methods validation is mandatory in order to assess the fitness of purpose of the developed analytical method. Of core importance at the end of the validation is the evaluation of the reliability of the individual results that will be generated during the routine application of the method. Regulatory guidelines provide a general framework to assess the validity of a method, but none address the issue of results reliability. In this study, a Bayesian approach is proposed to address this concern. Results reliability is defined here as “the probability ()π of an analytical method to provide analytical results within predefined acceptance limits ()X()λ± around their reference or conventional true concentration values ()Tμ over a defined concentration range and under given environmental and operating conditions.” By providing the minimum reliability probability (minπ needed for the subsequent routine application of the method, as well as specifications or acceptance limits ()λ±, the proposed Bayesian approach provides the effective probability of obtaining reliable future analytical results over the whole concentration range investigated. This is summarized in a single graph: the reliability profile. This Bayesian reliability profile is also compared to two frequentist approaches, the first one derived from the work of Dewé et al. [1] and the second proposed by Govaerts et al. [2]. Furthermore, the applicability of the Bayesian reliability profile is shown using as example the validation of a bioanalytical method dedicated to the determination of ketoglutaric acid (KG) and hydroxymethylfurfural (HMF) in human plasma by SPE-HPLC-UV. [1] Dewé W., Govaerts B., Boulanger B., Rozet E., Chiap P., Hubert Ph., Chemometr. Intell. Lab. Syst. 85 (2007) 262-268. [2] B. Govaerts, W. Dewé, M. Maumy, B. Boulanger, Qual. Reliab. Engng. Int. 24 (2008) 667-680. [less ▲]

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See detailReliability of ERT-derived Temperature - Insights from Laboratory Measurements
Robert, Tanguy ULg; Hermans, Thomas ULg; Dumont, Gaël ULg et al

in EarthDoc - Near Surface Geosciences 2013 - 19th European Meeting of Environmental and Engineering Geophysics (2013, September)

We performed laboratory measurements on fully saturated sand samples in the context of deriving reliable temperature from time-lapse electrical resistivity tomography (ERT). The experiment consisted in ... [more ▼]

We performed laboratory measurements on fully saturated sand samples in the context of deriving reliable temperature from time-lapse electrical resistivity tomography (ERT). The experiment consisted in monitoring an increase of temperature in sand samples with electrical resistivity measurements. We neglected the effect of surface conductivity since experiments showed two orders of magnitude between surface and fluid conductivities. We show that using simple linear relationship between fluid electrical conductivity and temperature alone does not allow reliable temperature estimates. Indeed, chemical analyses highlight the importance of accounting chemical reactions occurring when temperature changes, including dissolution/precipitation processes. We performed two experiments based on typical in-situ conditions. We first simulated the injection of a less conductive tap water and second, the injection of heated formation water. In the second case, minerals solubility decreases and precipitation occurs, leading to an increase of bulk resistivity. This mechanism competes with dissolution of minerals when tap water is injected, since tap water is not in equilibrium with the medium. In any case, further research is needed to fully understand the mechanisms and to develop a fully integrated law to derive better temperature estimates. [less ▲]

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See detailReliability of resistivity-derived temperature: insights from laboratory measurements
Robert, Tanguy ULg; Hermans, Thomas ULg; Dumont, Gaël ULg et al

Conference (2013, December 06)

This contribution consists in studying the reliability of resistivity-derived temperature, for example from time-lapse electrical resistivity tomography (ERT) surveys. The idea of using temperature as a ... [more ▼]

This contribution consists in studying the reliability of resistivity-derived temperature, for example from time-lapse electrical resistivity tomography (ERT) surveys. The idea of using temperature as a quantitative tracer is growing in the hydrogeophysical community, especially to simulate geo/hydrothermal systems. However, plenty of physico-chemical processes are influenced by temperature and most of them impact directly resistivity measurements. Therefore, one needs to take them into account to retrieve quantitative temperature estimates from resistivity measurements but, up to now, it is seldom the case. The experiment we conducted consisted in simulating an ERT monitoring of heat storage in a sandy aquifer. We show that using experimental relationships between fluid electrical conductivity and temperature alone does not allow reliable temperature estimates, simply because rock-water interactions are neglected. Worst, from a certain temperature (45°C here), the bulk resistivity starts to increase with temperature although this is not expected from the experimental law. Chemical analyses made on water samples collected during the experiment highlight the importance of accounting chemical reactions (e.g. calcite precipitation with increasing temperature) occurring when temperature changes as well as their kinetics. Finally, other parameters as surface conductivity cannot always be neglected when estimating temperature from resistivity measurements. This means that retrieving reliable temperatures from bulk resistivity measurements (e.g. time-lapse ERT) requires the knowledge of water mineralization as well as the rock / soil mineralogy in order to fully integrate physico-chemical reactions between groundwater and the host rock, for example with a joint inversion scheme. [less ▲]

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See detailReliability of the TEC computed using GPS measurements: the problem of hardware biases
Warnant, René ULg

in Acta Geodaetica et Geophysica Hungarica (1997), 32(3-4), 451-459

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See detailReliability of transport models calibrated on field tracer experiments: breakthrough curve sensitivity to tracer injection conditions
Brouyère, Serge ULg; Dassargues, Alain ULg

in in Calibration and Reliability in Groundwater Modelling: A Few Steps Closer to Reality (2002)

The reliability of groundwater transport models depends strongly on accurate identification of hydrodispersive processes and quantification of corresponding parameters. Calibration of these models is ... [more ▼]

The reliability of groundwater transport models depends strongly on accurate identification of hydrodispersive processes and quantification of corresponding parameters. Calibration of these models is often performed using results of field tracer experiments. However, little attention is usually paid to the influence of injection conditions and well-aquifer interactions on resulting breakthrough curves at the sampling well. The tracer input function in the aquifer is often assimilated to a Dirac impulse and the breakthrough curve is supposed to reflect only the hydrodispersive processes affecting the tracer behaviour in groundwater. Actually, flow conditions, aquifer heterogeneity and well-aquifer interactions can have a significant influence on tracer injection. Using a new mathematical approach developed to model well-aquifer interactions and injection conditions in a more physical way, numerical experiments were conducted in order to highlight the potential impact of injection conditions on the results of radially converging flow tracer tests. This analysis clearly shows that neglecting the influence of actual injection conditions can lead to: (a) errors on fitted parameters; (b) misleading identification of the active transport processes. [less ▲]

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See detailReliable and efficient numerical simulation of a model of tissue differentiation in a bone chamber model
Gerisch, A.; Geris, Liesbet ULg; Van Oosterwyck, Hans et al

in Bischoff, G. (Ed.) Micro- and Nanostructures of Biological Systems (2005)

For the study of peri-implant tissue differentiation, a repeated sampling bone chamber has been developed. Mathematical models, which describe tissue differentiation, help to gain insight into the ... [more ▼]

For the study of peri-implant tissue differentiation, a repeated sampling bone chamber has been developed. Mathematical models, which describe tissue differentiation, help to gain insight into the processes taking place in the chamber. We consider here the numerical solution of a taxis-diffusion-reaction partial differential equation model. The general approach is the method of lines and we pay special attention to transfer qualitative features of the solution to the numerical approximation. These features are the conservation of mass principle and the nonnegativity of concentration values. This is achieved by following the finite volume idea and by employing positivity preserving spatial discretization, respectively. An instructive example is given. The time integration is performed with ROWMAP, a suitable implicit time integration method with time step size control. Altogether, this yields a reliable and efficient numerical solution technique. A numerical simulation of the tissue differentiation process in the chamber is presented and discussed. [less ▲]

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See detailReliable Approximation Schemes for Composite Structures Optimization"
Bruyneel, Michaël ULg; Vermaut, O.; Fleury, Claude ULg

in Van Keer, R.; Verhegghe, B.; Hogge, M. (Eds.) et al ACOMEN ’98 : an international conference on advanced computational methods in engineering : Ghent, 2-4 september 1998 (1998, September)

Detailed reference viewed: 13 (0 ULg)
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See detailA reliable finite volume scheme for quasi 3D dam-break flood wave propagations
Pirotton, Michel ULg

in Risk Analysis 2000 (2000)

Detailed reference viewed: 5 (1 ULg)
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See detailReliable Hashing Without Collision Detection
Wolper, Pierre ULg; Leroy, Denis

in Computer Aided Verification, Proc. 5th Int. Workshop (1993)

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See detailReliable hydraulic numerical modeling with multiblock grids and linked models
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Proc. Int. Conf. SimHydro 2010: Hydraulic modeling and uncertainty (2010)

Detailed reference viewed: 17 (4 ULg)