76 research outputs found

    Cholesteryl ester transfer protein: at the heart of the action of lipid-modulating therapy with statins, fibrates, niacin, and cholesteryl ester transfer protein inhibitors

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    Subnormal plasma levels of high-density lipoprotein cholesterol (HDL-C) constitute a major cardiovascular risk factor; raising low HDL-C levels may therefore reduce the residual cardiovascular risk that frequently presents in dyslipidaemic subjects despite statin therapy. Cholesteryl ester transfer protein (CETP), a key modulator not only of the intravascular metabolism of HDL and apolipoprotein (apo) A-I but also of triglyceride (TG)-rich particles and low-density lipoprotein (LDL), mediates the transfer of cholesteryl esters from HDL to pro-atherogenic apoB-lipoproteins, with heterotransfer of TG mainly from very low-density lipoprotein to HDL. Cholesteryl ester transfer protein activity is elevated in the dyslipidaemias of metabolic disease involving insulin resistance and moderate to marked hypertriglyceridaemia, and is intimately associated with premature atherosclerosis and high cardiovascular risk. Cholesteryl ester transfer protein inhibition therefore presents a preferential target for elevation of HDL-C and reduction in atherosclerosis. This review appraises recent evidence for a central role of CETP in the action of current lipid-modulating agents with HDL-raising potential, i.e. statins, fibrates, and niacin, and compares their mechanisms of action with those of pharmacological agents under development which directly inhibit CETP. New CETP inhibitors, such as dalcetrapib and anacetrapib, are targeted to normalize HDL/apoA-I levels and anti-atherogenic activities of HDL particles. Further studies of these CETP inhibitors, in particular in long-term, large-scale outcome trials, will provide essential information on their safety and efficacy in reducing residual cardiovascular risk

    Effect of a medical food on body mass index and activities of daily living in patients with Alzheimer's disease: secondary analyses from a randomized, controlled trial

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    Contains fulltext : 97852.pdf (publisher's version ) (Closed access)OBJECTIVES: To investigate the effect of a medical food (Souvenaid) on body mass index (BMI) and functional abilities in patients with mild Alzheimer's disease (AD). DESIGN/SETTING/PARTICIPANTS/INTERVENTION /MEASUREMENTS: These analyses were performed on data from a 12-week, double-blind, randomized, controlled, multicenter, proof-of-concept study with a similarly designed and exploratory 12-week extension period. Patients with mild AD (Mini-Mental State Examination score of 20-26) were randomized to receive either the active product or an iso-caloric control product. While primary outcomes included measures of cognition, the 23-item Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale was included as a secondary outcome. Both ADCS-ADL and BMI were assessed at baseline and Weeks 6, 12 and 24. Data were analyzed using a repeated-measures mixed model. RESULTS: Overall, data suggested an increased BMI in the active versus the control group at Week 24 (ITT: p = 0.07; PP: p = 0.03), but no treatment effect on ADCS-ADL was observed. However, baseline BMI was found to be a significant treatment effect modifier (ITT: p = 0.04; PP: p = 0.05), and an increase in ADCS-ADL was observed at Week 12 in patients with a 'low' baseline BMI (ITT: p = 0.02; PP: p = 0.04). CONCLUSIONS: These data indicate that baseline BMI significantly impacts the effect of Souvenaid on functional abilities. In addition, there was a suggestion that Souvenaid increased BMI

    Quantification of microseismic noise generation in the coastal band and implications for seismic imaging : contribution of distributed acoustic measurement on optical fiber

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    Les ocĂ©ans et mers, qui reprĂ©sentent plus de 70% de la surface de la terre sont jonchĂ©s de cĂąbles Ă  fibre optique exploitĂ©s par les rĂ©seaux de tĂ©lĂ©communications et malgrĂ© cette instrumentalisation massive, les fonds ocĂ©aniques restent relativement inconnus. Depuis une vingtaine d'annĂ©es, l'intĂ©rĂȘt pour les systĂšmes de capteurs acoustiques distribuĂ©s (DAS) ne cesse d'augmenter grĂące Ă  leur capacitĂ© Ă  transformer ces cĂąbles en capteurs sismiques capables de mesurer des perturbations extĂ©rieures. Ces interrogateurs DAS peuvent mesurer les interactions acoustiques (sous forme de taux de dĂ©formation) le long d'un cĂąble Ă  fibre optique. Ils fournissent une grande ouverture de dĂ©tection pour l'acquisition de donnĂ©es acoustiques et sismiques Ă  haute rĂ©solution dans les domaines temporel et spatial, Ă  terre ou en milieu marin ; l'enregistrement peut se faire sur une large gamme de frĂ©quences (du mHz au kHz) Ă  une rĂ©solution spatiale de l'ordre du mĂ©trique.Dans notre Ă©tude, nous exploitons un cĂąble de 42 km situĂ© au large de Toulon, France, allant de la marge (0 m) jusqu'Ă  la plaine abyssale (2500 m). Ainsi, nous quantifions prĂ©cisĂ©ment les ondes de gravitĂ© ocĂ©aniques voyageant jusqu'Ă  la cĂŽte, qui se rĂ©flĂ©chissent, et mĂšnent Ă  la gĂ©nĂ©ration de sources microsismiques (SM) dites « cĂŽtiĂšres ». En moyenne, 30% de ces ondes sont rĂ©flĂ©chies Ă  la cĂŽte ; leur intensitĂ© influe sur celle du bruit microsismique gĂ©nĂ©rĂ© localement, et leur azimut Ă  un impact sur la position des SM qui dominent les enregistrements. Par ailleurs, cette analyse a montrĂ© une forte diversitĂ© de vitesses apparentes utilisables pour produire une imagerie. Dans un deuxiĂšme temps, nous cherchons Ă  comprendre l'impact de ces changements de position des SM sur les vitesses apparentes que l'on sĂ©lectionne. Nous montrons que la vitesse rĂ©elle (i.e. la vitesse la plus faible) est toujours identique, quelle que soit la puissance de la houle, ce qui montre qu'il existe en tout temps des sources le long de la cĂŽte. Par ailleurs, lorsque nous pointons la plus haute Ă©nergie - habituellement utilisĂ© lors de tomographies traditionnelles, quelques diffĂ©rences apparaissent (quelques centaines de m/s). Nous montrons qu'il existe plusieurs sources sur des diagrammes de pointĂ©e traditionnels. De ce fait, nous avons fait une tomographie en utilisant 900 capteurs linĂ©aires issus d'un segment perpendiculaire Ă  la cĂŽte, oĂč la sensibilitĂ© de la fibre est maximale. Puis nous avons fait un autre modĂšle en utilisant des vitesses apparentes, corrigĂ© d'un angle correspondant Ă  la position de source dominante par rapport au cĂąble. Nous montrons qu'il y a des diffĂ©rences significatives entre ces 2 modĂšles, de quelques centaines de m/s Ă  presque 1000 m/s lorsqu'on augmente en profondeur.Oceans and Seas, which represent more than 70% of the earth's surface, are littered with fiber optic cables operated by telecommunication networks and despite this massive instrumentalization, the ocean floor remains relatively unknown. For the last twenty years, the interest in distributed acoustic sensor systems (DAS) has been growing due to their ability to transform these cables into seismic sensors capable of measuring external disturbances. These DAS interrogators can measure acoustic interactions (as strain-rate) along a fiber optic cable. They provide a large sensing aperture for acquiring high-resolution acoustic and seismic data in the time and space domains, on land or in the marine environment ; recording can be done over a wide frequency range (from mHz to kHz) at metric spatial resolution.In this work, we operate a 42 km cable located off Toulon, France, going from the margin (0 m) to the abyssal plain (2500 m). We quantify precisely the ocean gravity waves traveling to the coast, which reflect and lead to the generation of microseismic (MS) sources called "coastal reflection". On average, 30% of these waves are reflected at the coast ; their heigh influences the intensity of the microseismic noise generated locally, and their azimuth has an impact on the position of the SM that dominate the recordings. Furthermore, this analysis showed a high diversity of apparent velocities that can be used to produce an image. In a second step, we try to understand the impact of these changes in the position of the SM on the apparent velocities we pick. We show that the true velocity (i.e. the lowest velocity) is always the same, whatever the power of the swell, which shows that there are sources along the coast at all times. Moreover, when we point at the highest energy - usually used in traditional tomography, some differences appear (a few hundred m/s). We show that there are several sources on traditional pointing diagrams. Therefore, we made a tomography using 900 linear sensors from a segment perpendicular to the coast, where the sensitivity of the fiber is maximum. Then we made another model using apparent velocities, corrected by an angle corresponding to the dominant source position with respect to the cable. We show that there are significant differences between these two models, from a few hundred m/s to almost 1000 m/s when increasing in depth

    Quantification de la génération de bruits microsismiques dans la bande cÎtiÚre et implications pour l'imagerie sismique : apport de la mesure acoustique distribuée sur fibre optique

    No full text
    Oceans and Seas, which represent more than 70% of the earth's surface, are littered with fiber optic cables operated by telecommunication networks and despite this massive instrumentalization, the ocean floor remains relatively unknown. For the last twenty years, the interest in distributed acoustic sensor systems (DAS) has been growing due to their ability to transform these cables into seismic sensors capable of measuring external disturbances. These DAS interrogators can measure acoustic interactions (as strain-rate) along a fiber optic cable. They provide a large sensing aperture for acquiring high-resolution acoustic and seismic data in the time and space domains, on land or in the marine environment ; recording can be done over a wide frequency range (from mHz to kHz) at metric spatial resolution.In this work, we operate a 42 km cable located off Toulon, France, going from the margin (0 m) to the abyssal plain (2500 m). We quantify precisely the ocean gravity waves traveling to the coast, which reflect and lead to the generation of microseismic (MS) sources called "coastal reflection". On average, 30% of these waves are reflected at the coast ; their heigh influences the intensity of the microseismic noise generated locally, and their azimuth has an impact on the position of the SM that dominate the recordings. Furthermore, this analysis showed a high diversity of apparent velocities that can be used to produce an image. In a second step, we try to understand the impact of these changes in the position of the SM on the apparent velocities we pick. We show that the true velocity (i.e. the lowest velocity) is always the same, whatever the power of the swell, which shows that there are sources along the coast at all times. Moreover, when we point at the highest energy - usually used in traditional tomography, some differences appear (a few hundred m/s). We show that there are several sources on traditional pointing diagrams. Therefore, we made a tomography using 900 linear sensors from a segment perpendicular to the coast, where the sensitivity of the fiber is maximum. Then we made another model using apparent velocities, corrected by an angle corresponding to the dominant source position with respect to the cable. We show that there are significant differences between these two models, from a few hundred m/s to almost 1000 m/s when increasing in depth.Les ocĂ©ans et mers, qui reprĂ©sentent plus de 70% de la surface de la terre sont jonchĂ©s de cĂąbles Ă  fibre optique exploitĂ©s par les rĂ©seaux de tĂ©lĂ©communications et malgrĂ© cette instrumentalisation massive, les fonds ocĂ©aniques restent relativement inconnus. Depuis une vingtaine d'annĂ©es, l'intĂ©rĂȘt pour les systĂšmes de capteurs acoustiques distribuĂ©s (DAS) ne cesse d'augmenter grĂące Ă  leur capacitĂ© Ă  transformer ces cĂąbles en capteurs sismiques capables de mesurer des perturbations extĂ©rieures. Ces interrogateurs DAS peuvent mesurer les interactions acoustiques (sous forme de taux de dĂ©formation) le long d'un cĂąble Ă  fibre optique. Ils fournissent une grande ouverture de dĂ©tection pour l'acquisition de donnĂ©es acoustiques et sismiques Ă  haute rĂ©solution dans les domaines temporel et spatial, Ă  terre ou en milieu marin ; l'enregistrement peut se faire sur une large gamme de frĂ©quences (du mHz au kHz) Ă  une rĂ©solution spatiale de l'ordre du mĂ©trique.Dans notre Ă©tude, nous exploitons un cĂąble de 42 km situĂ© au large de Toulon, France, allant de la marge (0 m) jusqu'Ă  la plaine abyssale (2500 m). Ainsi, nous quantifions prĂ©cisĂ©ment les ondes de gravitĂ© ocĂ©aniques voyageant jusqu'Ă  la cĂŽte, qui se rĂ©flĂ©chissent, et mĂšnent Ă  la gĂ©nĂ©ration de sources microsismiques (SM) dites « cĂŽtiĂšres ». En moyenne, 30% de ces ondes sont rĂ©flĂ©chies Ă  la cĂŽte ; leur intensitĂ© influe sur celle du bruit microsismique gĂ©nĂ©rĂ© localement, et leur azimut Ă  un impact sur la position des SM qui dominent les enregistrements. Par ailleurs, cette analyse a montrĂ© une forte diversitĂ© de vitesses apparentes utilisables pour produire une imagerie. Dans un deuxiĂšme temps, nous cherchons Ă  comprendre l'impact de ces changements de position des SM sur les vitesses apparentes que l'on sĂ©lectionne. Nous montrons que la vitesse rĂ©elle (i.e. la vitesse la plus faible) est toujours identique, quelle que soit la puissance de la houle, ce qui montre qu'il existe en tout temps des sources le long de la cĂŽte. Par ailleurs, lorsque nous pointons la plus haute Ă©nergie - habituellement utilisĂ© lors de tomographies traditionnelles, quelques diffĂ©rences apparaissent (quelques centaines de m/s). Nous montrons qu'il existe plusieurs sources sur des diagrammes de pointĂ©e traditionnels. De ce fait, nous avons fait une tomographie en utilisant 900 capteurs linĂ©aires issus d'un segment perpendiculaire Ă  la cĂŽte, oĂč la sensibilitĂ© de la fibre est maximale. Puis nous avons fait un autre modĂšle en utilisant des vitesses apparentes, corrigĂ© d'un angle correspondant Ă  la position de source dominante par rapport au cĂąble. Nous montrons qu'il y a des diffĂ©rences significatives entre ces 2 modĂšles, de quelques centaines de m/s Ă  presque 1000 m/s lorsqu'on augmente en profondeur

    Quantification de la génération de bruits microsismiques dans la bande cÎtiÚre et implications pour l'imagerie sismique : apport de la mesure acoustique distribuée sur fibre optique

    No full text
    Oceans and Seas, which represent more than 70% of the earth's surface, are littered with fiber optic cables operated by telecommunication networks and despite this massive instrumentalization, the ocean floor remains relatively unknown. For the last twenty years, the interest in distributed acoustic sensor systems (DAS) has been growing due to their ability to transform these cables into seismic sensors capable of measuring external disturbances. These DAS interrogators can measure acoustic interactions (as strain-rate) along a fiber optic cable. They provide a large sensing aperture for acquiring high-resolution acoustic and seismic data in the time and space domains, on land or in the marine environment ; recording can be done over a wide frequency range (from mHz to kHz) at metric spatial resolution.In this work, we operate a 42 km cable located off Toulon, France, going from the margin (0 m) to the abyssal plain (2500 m). We quantify precisely the ocean gravity waves traveling to the coast, which reflect and lead to the generation of microseismic (MS) sources called "coastal reflection". On average, 30% of these waves are reflected at the coast ; their heigh influences the intensity of the microseismic noise generated locally, and their azimuth has an impact on the position of the SM that dominate the recordings. Furthermore, this analysis showed a high diversity of apparent velocities that can be used to produce an image. In a second step, we try to understand the impact of these changes in the position of the SM on the apparent velocities we pick. We show that the true velocity (i.e. the lowest velocity) is always the same, whatever the power of the swell, which shows that there are sources along the coast at all times. Moreover, when we point at the highest energy - usually used in traditional tomography, some differences appear (a few hundred m/s). We show that there are several sources on traditional pointing diagrams. Therefore, we made a tomography using 900 linear sensors from a segment perpendicular to the coast, where the sensitivity of the fiber is maximum. Then we made another model using apparent velocities, corrected by an angle corresponding to the dominant source position with respect to the cable. We show that there are significant differences between these two models, from a few hundred m/s to almost 1000 m/s when increasing in depth.Les ocĂ©ans et mers, qui reprĂ©sentent plus de 70% de la surface de la terre sont jonchĂ©s de cĂąbles Ă  fibre optique exploitĂ©s par les rĂ©seaux de tĂ©lĂ©communications et malgrĂ© cette instrumentalisation massive, les fonds ocĂ©aniques restent relativement inconnus. Depuis une vingtaine d'annĂ©es, l'intĂ©rĂȘt pour les systĂšmes de capteurs acoustiques distribuĂ©s (DAS) ne cesse d'augmenter grĂące Ă  leur capacitĂ© Ă  transformer ces cĂąbles en capteurs sismiques capables de mesurer des perturbations extĂ©rieures. Ces interrogateurs DAS peuvent mesurer les interactions acoustiques (sous forme de taux de dĂ©formation) le long d'un cĂąble Ă  fibre optique. Ils fournissent une grande ouverture de dĂ©tection pour l'acquisition de donnĂ©es acoustiques et sismiques Ă  haute rĂ©solution dans les domaines temporel et spatial, Ă  terre ou en milieu marin ; l'enregistrement peut se faire sur une large gamme de frĂ©quences (du mHz au kHz) Ă  une rĂ©solution spatiale de l'ordre du mĂ©trique.Dans notre Ă©tude, nous exploitons un cĂąble de 42 km situĂ© au large de Toulon, France, allant de la marge (0 m) jusqu'Ă  la plaine abyssale (2500 m). Ainsi, nous quantifions prĂ©cisĂ©ment les ondes de gravitĂ© ocĂ©aniques voyageant jusqu'Ă  la cĂŽte, qui se rĂ©flĂ©chissent, et mĂšnent Ă  la gĂ©nĂ©ration de sources microsismiques (SM) dites « cĂŽtiĂšres ». En moyenne, 30% de ces ondes sont rĂ©flĂ©chies Ă  la cĂŽte ; leur intensitĂ© influe sur celle du bruit microsismique gĂ©nĂ©rĂ© localement, et leur azimut Ă  un impact sur la position des SM qui dominent les enregistrements. Par ailleurs, cette analyse a montrĂ© une forte diversitĂ© de vitesses apparentes utilisables pour produire une imagerie. Dans un deuxiĂšme temps, nous cherchons Ă  comprendre l'impact de ces changements de position des SM sur les vitesses apparentes que l'on sĂ©lectionne. Nous montrons que la vitesse rĂ©elle (i.e. la vitesse la plus faible) est toujours identique, quelle que soit la puissance de la houle, ce qui montre qu'il existe en tout temps des sources le long de la cĂŽte. Par ailleurs, lorsque nous pointons la plus haute Ă©nergie - habituellement utilisĂ© lors de tomographies traditionnelles, quelques diffĂ©rences apparaissent (quelques centaines de m/s). Nous montrons qu'il existe plusieurs sources sur des diagrammes de pointĂ©e traditionnels. De ce fait, nous avons fait une tomographie en utilisant 900 capteurs linĂ©aires issus d'un segment perpendiculaire Ă  la cĂŽte, oĂč la sensibilitĂ© de la fibre est maximale. Puis nous avons fait un autre modĂšle en utilisant des vitesses apparentes, corrigĂ© d'un angle correspondant Ă  la position de source dominante par rapport au cĂąble. Nous montrons qu'il y a des diffĂ©rences significatives entre ces 2 modĂšles, de quelques centaines de m/s Ă  presque 1000 m/s lorsqu'on augmente en profondeur

    Quantification de la génération de bruits microsismiques dans la bande cÎtiÚre et implications pour l'imagerie sismique : apport de la mesure acoustique distribuée sur fibre optique

    No full text
    Oceans and Seas, which represent more than 70% of the earth's surface, are littered with fiber optic cables operated by telecommunication networks and despite this massive instrumentalization, the ocean floor remains relatively unknown. For the last twenty years, the interest in distributed acoustic sensor systems (DAS) has been growing due to their ability to transform these cables into seismic sensors capable of measuring external disturbances. These DAS interrogators can measure acoustic interactions (as strain-rate) along a fiber optic cable. They provide a large sensing aperture for acquiring high-resolution acoustic and seismic data in the time and space domains, on land or in the marine environment ; recording can be done over a wide frequency range (from mHz to kHz) at metric spatial resolution.In this work, we operate a 42 km cable located off Toulon, France, going from the margin (0 m) to the abyssal plain (2500 m). We quantify precisely the ocean gravity waves traveling to the coast, which reflect and lead to the generation of microseismic (MS) sources called "coastal reflection". On average, 30% of these waves are reflected at the coast ; their heigh influences the intensity of the microseismic noise generated locally, and their azimuth has an impact on the position of the SM that dominate the recordings. Furthermore, this analysis showed a high diversity of apparent velocities that can be used to produce an image. In a second step, we try to understand the impact of these changes in the position of the SM on the apparent velocities we pick. We show that the true velocity (i.e. the lowest velocity) is always the same, whatever the power of the swell, which shows that there are sources along the coast at all times. Moreover, when we point at the highest energy - usually used in traditional tomography, some differences appear (a few hundred m/s). We show that there are several sources on traditional pointing diagrams. Therefore, we made a tomography using 900 linear sensors from a segment perpendicular to the coast, where the sensitivity of the fiber is maximum. Then we made another model using apparent velocities, corrected by an angle corresponding to the dominant source position with respect to the cable. We show that there are significant differences between these two models, from a few hundred m/s to almost 1000 m/s when increasing in depth.Les ocĂ©ans et mers, qui reprĂ©sentent plus de 70% de la surface de la terre sont jonchĂ©s de cĂąbles Ă  fibre optique exploitĂ©s par les rĂ©seaux de tĂ©lĂ©communications et malgrĂ© cette instrumentalisation massive, les fonds ocĂ©aniques restent relativement inconnus. Depuis une vingtaine d'annĂ©es, l'intĂ©rĂȘt pour les systĂšmes de capteurs acoustiques distribuĂ©s (DAS) ne cesse d'augmenter grĂące Ă  leur capacitĂ© Ă  transformer ces cĂąbles en capteurs sismiques capables de mesurer des perturbations extĂ©rieures. Ces interrogateurs DAS peuvent mesurer les interactions acoustiques (sous forme de taux de dĂ©formation) le long d'un cĂąble Ă  fibre optique. Ils fournissent une grande ouverture de dĂ©tection pour l'acquisition de donnĂ©es acoustiques et sismiques Ă  haute rĂ©solution dans les domaines temporel et spatial, Ă  terre ou en milieu marin ; l'enregistrement peut se faire sur une large gamme de frĂ©quences (du mHz au kHz) Ă  une rĂ©solution spatiale de l'ordre du mĂ©trique.Dans notre Ă©tude, nous exploitons un cĂąble de 42 km situĂ© au large de Toulon, France, allant de la marge (0 m) jusqu'Ă  la plaine abyssale (2500 m). Ainsi, nous quantifions prĂ©cisĂ©ment les ondes de gravitĂ© ocĂ©aniques voyageant jusqu'Ă  la cĂŽte, qui se rĂ©flĂ©chissent, et mĂšnent Ă  la gĂ©nĂ©ration de sources microsismiques (SM) dites « cĂŽtiĂšres ». En moyenne, 30% de ces ondes sont rĂ©flĂ©chies Ă  la cĂŽte ; leur intensitĂ© influe sur celle du bruit microsismique gĂ©nĂ©rĂ© localement, et leur azimut Ă  un impact sur la position des SM qui dominent les enregistrements. Par ailleurs, cette analyse a montrĂ© une forte diversitĂ© de vitesses apparentes utilisables pour produire une imagerie. Dans un deuxiĂšme temps, nous cherchons Ă  comprendre l'impact de ces changements de position des SM sur les vitesses apparentes que l'on sĂ©lectionne. Nous montrons que la vitesse rĂ©elle (i.e. la vitesse la plus faible) est toujours identique, quelle que soit la puissance de la houle, ce qui montre qu'il existe en tout temps des sources le long de la cĂŽte. Par ailleurs, lorsque nous pointons la plus haute Ă©nergie - habituellement utilisĂ© lors de tomographies traditionnelles, quelques diffĂ©rences apparaissent (quelques centaines de m/s). Nous montrons qu'il existe plusieurs sources sur des diagrammes de pointĂ©e traditionnels. De ce fait, nous avons fait une tomographie en utilisant 900 capteurs linĂ©aires issus d'un segment perpendiculaire Ă  la cĂŽte, oĂč la sensibilitĂ© de la fibre est maximale. Puis nous avons fait un autre modĂšle en utilisant des vitesses apparentes, corrigĂ© d'un angle correspondant Ă  la position de source dominante par rapport au cĂąble. Nous montrons qu'il y a des diffĂ©rences significatives entre ces 2 modĂšles, de quelques centaines de m/s Ă  presque 1000 m/s lorsqu'on augmente en profondeur

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