Development of thromboxane A2 modulators as promising anti-metastatic and anti-angiogenic compounds

Conference (2004, May)

La copie de la "Cène" de Léonard de Vinci conservée à l'abbaye de Tongerlo

Conference (2004, April 30)

Greenland ice sheet melt: intercomparison between SSM/I and a regional climate model

Conference (2004, April 27)

The daily melt extent on the Greenland ice sheet can easily be retrieved from satellite observations and therefore is a very useful index to study the surface mass balance (SMB) evolution of the last ... [more ▼]

The daily melt extent on the Greenland ice sheet can easily be retrieved from satellite observations and therefore is a very useful index to study the surface mass balance (SMB) evolution of the last years. It is also particularly helpful for the validation of a model because there is little in-situ observations on the Greenland ice sheet. The remote sensing melt-detection algorithms use the changes in microwave brightness temperatures during snowmelt. The most used one on Greenland is the cross-polarized gradient ratio (XPGR) method from Abdalati and Steffen (1997)*. It was found from a comparison with simulations made by the regional climate model MAR (Modèle Atmosphérique Régional) that the rainfall on the ice sheet in summer perturbs the melt signal detected by XPGR via the 37-Ghz vertical channel. An improved XPGR algorithm was developed. We present here our motivation to modify the XPGR. An intercomparaison between the SSM/I derived observations and the MAR is performed. The aim is to validate our model, in order to study the SMB for future climate. The simulated extent and time evolution of the wet snow zone compares better with satellite derived data when the modified XPGR method is used. [less ▲]

Endovascular aneurysm treatment: angiographic and clinical follow-up in a series of 114 consecutive lesions

Conference (2004, April 27)

The main characteristics of Saturn's aurora

Conference (2004, April 25)

Methodological Approaches to the Analysis of Dead Languages. Semantics and Pragmatics of Verbal Clauses

Conference (2004, April 23)

Prévention des infections périnatales à streptocoques du groupe B: recommandations du Conseil Supérieur d'Hygiène

Conference (2004, April 22)

A nested-grid model with data assimilation in the Gulf of Lions

Conference (2004, April)

When a model combines the use of nested grids and data assimilation, a preliminary, simple, 1D test case showed the interest of combining the different state vectors coming from the different grids, into ... [more ▼]

When a model combines the use of nested grids and data assimilation, a preliminary, simple, 1D test case showed the interest of combining the different state vectors coming from the different grids, into one single vector, and using global error matrices covering all the grids at once. In this case, the assimilation procedure provides errorspace feedback from the fine grid to the coarser grid, which proves to be even more important than the statevector feedback. For data located in the fine grid, assimilation of the same data in the coarse grids is not necessary anymore, as both model and errorspace feedback is performed during assimilation. Large data transfers from local to basin-scale models can be avoided. The GHER hydrodynamic model (for a full description, see e.g. [1]) is applied to a three times nested model covering (a) the Mediterrannean Sea at 1/4 degree, (b) the Liguro-Provencal Bassin at 1/20 degree, and (c) the Gulf of Lions at 1/100 degree. The simulation starts on Januari 1st, 1998, using ECMWF atmospheric forcings and MODB4/MEDAR climatic data. As the model allows mode splitting, the simulation uses 2D timesteps of 3 seconds, and 3D timesteps of 3 minutes, on each grid. A twin experiment is performed. The perturbed initial condition is a delayed model state of the reference run. An initial reduced-rank model errorspace is constructed from 20 EOFs, themselves built from the reference run, over all three grids at the same time. Surface temperature and salinity from the reference run are assimilated in the model every 24 hours, using reduced-rank optimal interpolation (see [2]). Different simulations are implemented, using different ways to combine grid nesting and data assimilation: with or without state vector feedback, with data assimilation only in the local grid, or in the coarser grids, or both, and with or without errorspace feedback (i.e. with 3 separated statevectors or with one global statevector). The comparison of those experiments comfirms that using one global statevector reduces the error in the coarser grids much faster. The effect of data assimilation, and the performances of the different methods, can be examined by calculating RMS errors between the perturbed runs and the reference run. They can also be observed by following the model state trajectory in the EOFspace (for example, using the first three EOFs). In the context of the twin experiment described above, the first assimilation cycle clearly brings the model back in time. This is consistent with the choice of the perturbed initial conditions, being a delayed state of the reference run. The following assimilation cycles have little effect, as the trajectory is already almost brought back on the reference trajectory. If other parameters are modified too (e.g. the atmospheric fluxes), each assimilation cycle has an important effect on the modelstate trajectory. A new experiment performs assimilation in the Gulf of Lions in the spring of 1998 using real observations. Different variables can be assimilated, using data collected during the FETCH campaign: NOAA/AVHRR SST, temperature and salinity from Atalante CTDs, or altimetric data from the ERS2 or TOPEX satellites. [less ▲]

Forecast verification in the Ligurian Sea. Multiresolution analysis and study of the thermocline

Conference (2004, April)

The results of the GHER 3D model are analysed, in order to establish the benefits of a Sea Surface Temperature (SST) assimilation experiment. The influence of the assimilation into the results of the ... [more ▼]

The results of the GHER 3D model are analysed, in order to establish the benefits of a Sea Surface Temperature (SST) assimilation experiment. The influence of the assimilation into the results of the model is examined first in the studied domain, the Ligurian Sea. Then, the benefit of the assimilation outside this domain (in the nearby zones at the surface, and in the Ligurian Sea at depth) is also studied. Finally, the effect of the SST assimilation on the other variables is examined. The procedure for the skill assessment of the model is as follows. First, the classical verification tools are applied: Root Mean Square Error (RMSE), Anomaly Correlation Coefficient (ACC), and Mean Square Error Skill Score (MSESS). Climatology and a free run of the model are used as reference systems. After this, a multiresolution analysis is carried out, to decompose the model results into different spatial scales. At each scale, the error measures mentioned above are applied. This allows to establish which scales are mainly contributing to the error. For this multiresolution analysis, a Discrete Wavelet Transform is used. The study of the assimilation benefits at depth is made by comparison with CTDs. The aim is to study the position and strength of the thermocline, as this zone presents high variability and it has an important impact into the system. A good representation of the thermocline is thus interesting. [less ▲]

On Dictatorship, Economic Development and Stability

Conference (2004, April)

A reduced order data assimilation scheme coupled with a two-way nested model. Application to the Ligurian Sea

Conference (2004, April)

A system of nested models is coupled with a data assimilation module. The system is composed by a low resolution model (1/4 ) covering the whole Mediterranean Sea, an intermediate resolution model (1/20 ... [more ▼]

A system of nested models is coupled with a data assimilation module. The system is composed by a low resolution model (1/4 ) covering the whole Mediterranean Sea, an intermediate resolution model (1/20 ) of the Liguro-Provençal basin and a high resolution model (1/60 ) simulating the fine mesoscale structures in the Ligurian Sea. Boundary conditions and the averaged fields (feedback) are exchanged between two successive nesting levels. A reduced order, optimal interpolation data assimilation scheme was implemented. The state vector is composed by temperature, salinity and sea surface elevation. Novel in the present approach is that these variables from the three nested model grids are assembled to one multigrid state vector. This implementation allows to take into account the correlation of the variables across the nested model grids in order to avoid for example artificial gradients after an assimilation cycle. The eigenvectors of the covariance matrix are constructed by an EOF analysis of the free model run. Cross-grid correlations especially in the overlapping domains are thus consistently represented. Horizontal correlations over long distances are suppressed by multiplying each error mode with a set of radial Gaussian functions. This procedure increases considerably the rank of the covariance matrix but ensures the local impact of each observation. Sea surface temperature (SST, from the DLR EOWEB), sea surface height (SSH, from the CLS) and CTD profiles (SIRENA cruise from SACLANT Center and cruises from the MEDAR/Medatlas database) are assimilated into the model. In overlapping model grids the measurements are related to the highest resolution grid. Since the SSH has a resolution of 1/8 , the surface elevation of the Ligurian Sea and the Liguro-Provençal model are filtered in order to be coherent with the space scales present in the observations. Starting from the 1st January 1998 the low and intermediate resolution models are spun up for 18 months. The initial conditions for the Ligurian Sea are interpolated from the intermediate resolution model. The three models are then integrated until August 1999. During this period SST, SSH and the CTD profiles are assimilated. The results are compared with a free model run. In particular the model forecast just before the assimilation step are compared with the observations. The model forecast and the measurements are then independent and the difference is a measure of the model forecast skill and the impact of the previous assimilation cycles. [less ▲]

The inconsistencies between the traditional structures of social dialogue and the network organizations’ reality

Conference (2004, April)

Jets instabilities producing the slot-tone

Conference (2004, April)

The nature of the instability governing the self-sustained tones produced by a low Mach number free plane jet impinging on a slotted plate, known as slot-tone, is identified experimentally. The ... [more ▼]

The nature of the instability governing the self-sustained tones produced by a low Mach number free plane jet impinging on a slotted plate, known as slot-tone, is identified experimentally. The experimental apparatus permits to control the Reynolds number and the distance from the jet outlet to the plate. For a Reynolds number, the shear-layer natural frequency and the jet column mode frequency of the free jet without the obstacle are estimated and compared to the minimal and maximal frequencies of the tones (for any position of the plate). The frequency of both instabilities defines the frequency domain of the self sustained tones. The lowest frequencies of the tones, obtained when the plate is placed downstream the end of the potential core, are the result of the amplification of the column mode frequency. On the other hand, the maximal frequency of the tones, obtained when the plate is situated near the jet outlet, is close to the natural shear-layer frequency. Moreover, when the tones frequency is higher than the natural shear-layer frequency, the sound pressure level produced is very inferior to the maximal sound pressure level measured at the same Reynolds number. This confirms the prominent role of the shear-layer instability in the self-sustained tones process for the highest frequencies. Tones with a frequency lower than the jet column mode frequency are rarely observed. [less ▲]

Noyaux de dattes: étude de la composition physico-chimique et des profils caractéristiques de la fraction lipidique

Conference (2004, March 21)

Le trouble d'attention avec hyperactivité. Diagnostic, évaluation et perspective de prise en charge

Conference (2004, March 18)

Xérogels de carbone chargés en métaux par solubilisation de sels dans la solution de précurseurs : influence sur la texture des matériaux carbonés

Conference (2004, March 15)

L’actualité imaginaire de Sartre et Foucault

Conference (2004, March 13)

Hypertension artérielle : nouvelles directives de prise en charge.

Conference (2004, March 11)

ETUDE PAR IMAGERIE NUMERIQUE ET GRANULOMETRIE LASER DE L'INFLUENCE DE HUIT ADJUVANTS SUR LA FORMATION DU JET DE PULVERISATION POUR TROIS TYPES DE BUSES.

Conference (2004, March 11)

The liquid sheet characteristics as a function of the adjuvant were measured using digital images. The droplet size distribution was measured using a Malvern particle size analyser. It appears that the ... [more ▼]

The liquid sheet characteristics as a function of the adjuvant were measured using digital images. The droplet size distribution was measured using a Malvern particle size analyser. It appears that the dynamical surface tension plays a critical role in the spray formation. Spray formulation containing Li-700, Silwet L-77, Flofix and Actirob are characterised by a lower dynamical surface tension than those containing Tensiofix D03, Trend 90, Frigate and Break-thru S240. For the three agricultural spray nozzles tested and in comparaison with pure water, the first group shortened the length of the liquid sheet before a perforation break-up mode when the second group lengthened it slightly before a wave disintegration break-up mode. The lengthening of the liquid sheet, is followed by a diminution of the VMD. [less ▲]

Place du sartan dans l'hypertension artérielle

Conference (2004, March 04)

Reliable simulation of mechatronic systems using Newmark algorithms

Conference (2004, March)

In the framework of flexible multibody systems simulation, the stability and the accuracy of the time integration process can be guaranteed by a family of implicit integrators derived from the Newmark ... [more ▼]

In the framework of flexible multibody systems simulation, the stability and the accuracy of the time integration process can be guaranteed by a family of implicit integrators derived from the Newmark scheme (Hilber-Hughes-Taylor and Generalized- methods). This paper deals with the extension of those reliable integrators for the simulation of mechatronic systems. In order to account for the strong coupling between the mechanism and the control system, the coupled set of equations contains mechanical and control variables. The generation of those equations, their numerical treatment and their time integration may become unmanageable for realistic control systems. In many cases, it is however sufficient to consider a weak coupling, which means that the action of the control system is treated as an external force disturbing the dynamic equilibrium. The weak coupling assumption is fully justified when a digital controller is present in the control loop. Then, the control actions exhibit discontinuous transitions at each sampling instant. The standard form of the Newmark scheme assumes continuity of the acceleration variables, and is thus not appropriate for this situation. Therefore, we propose an adapted Newmark scheme which achieves an explicit treatment of the acceleration jumps throughout the integration process, so that the proper simulation of the mechatronic system is guaranteed. The paper describes the detailed modifications of the integration algorithm. Illustrative examples are used to point out the critical situations where they prevent from substantial integration errors. [less ▲]

Design of nanoobjects endowed with specific properties

Conference (2004, March)

Pulsed holographic interferometry with photorefractive crystals. Recent advances of the european “PHIFE” project

Conference (2004, March)

Preparation of biodegradable porous materials

Conference (2004, February 20)

Hypertension artérielle et diabète : comment gérer?

Conference (2004, February 19)

Directives actualisées pour le traitement de l'hypertension artérielle

Conference (2004, February 11)

Systems Biology: A Systems Theory Perspective

Conference (2004, February)

Vocal folds lesions consecutive to respiratory tract infections

Conference (2004, February)

Développement de la lecture chez les enfants trisomiques 21

Conference (2004, January 24)

Study of metal regulation in Arabidopsis halleri

Conference (2004, January 22)

Quel traitement antihypertenseur pour quel patient?

Conference (2004, January 16)

Hypertension artérielle et facteurs de risque

Conference (2004, January 14)

Etat de l'art de l'holographie dynamique : systèmes appliqués à la métrologie et au contrôle non destructif

Conference (2004, January)

Dans ce papier, nous présentons le résultat de plus de dix années de recherche et développement au Centre Spatial de Liège (CSL) concernant une caméra holographique (utilisant la technique de l ... [more ▼]

Dans ce papier, nous présentons le résultat de plus de dix années de recherche et développement au Centre Spatial de Liège (CSL) concernant une caméra holographique (utilisant la technique de l'interférométrie holographique) capable d'effectuer des mesures, sans contact et sur un grand champ, de déplacements dans la gamme des microns et submicrons. Les principales applications montrées sont la recherche de défauts, l'identification de modes de vibration et la métrologie de déplacements. [less ▲]

Dynamic holography for fringerprints detection

Conference (2004, January)

Fingerprint detection method is generally based on optical contrast technique. We present a special case of holographic interferometry use, that envisages fingerprint visualisation on base of their relief ... [more ▼]

Fingerprint detection method is generally based on optical contrast technique. We present a special case of holographic interferometry use, that envisages fingerprint visualisation on base of their relief. Background of the algorithm is first presented and discussed. We finish by practical application. [less ▲]

Palynology of the Jauf Formation from the Northeastern part of the Arabian Shield

Conference (2004)

Field forecast verifi cation in the Mediterranean Sea. Discrete wavelet transforms of an assimilation experiment in a two-way nested model of the Ligurian Sea

Conference (2004)

Landscape metrics for the evaluation of trend reliability in remote sensing imagery.

Conference (2004)

Crystal chemistry of the divalent cation in the alluaudite structure

Conference (2004)

La contribution de l’écologie du paysage à l’analyse et à la gestion de l’environnement.

Conference (2004)

Mécènes ou commanditaires ? La Principauté de Liège de Louis de Bourbon à Gérard de Groesbeeck (1456-1580)

Conference (2004)

Llandovery biostratigraphy of the Paraná Basin, East Paraguay

Conference (2004)

L'expression narrative des Douze Césars, une modèle stylistique pour l'Histoire Auguste ? L'apport des analyses quantitatives et statistiques

Conference (2004)

Position of the Moesian platform at the Lochkovian. Hypothesis based on miospores

Conference (2004)

Use of mapped SSR markers to assist the selection of low-gossypol seeds and high-gossypol plant cultivars in upland cotton

Conference (2004)

Late Eifelian to earliest Givetian miospore assemblages from Central Northern Saudi Arabia

Conference (2004)

Pas si bête ... ou le propre de l'animal.

Conference (2004)

L’agriculture wallonne : les défis de l’avenir

Conference (2004)

Rôle pléiotrope de la protéine CRP chez Streptomyces coelicolor

Conference (2004)

The extreme right in Europe: the case of the French Front national and the Vlaams Blok

Conference (2004)

Gappy data in oceanographic data sets. reconstruction of sst avhrr cloudy images of the adriatic sea

Conference (2004)