Flexible Wedge Phased Array Transducers for Inspecting Variable-Geometry or Complex Components

The transmission of ultrasound from the transducer into the inspected component is a determining factor in the performance of ultrasound inspections. Various coupling solutions exist to ensure this transmission. The most frequently used are:• Immersion of the component in water tank: This coupling presents the best acoustic performance (low attenuation, coupling homogeneity, no intermediate interface). However, the inspected parts need to be fully immersed and thus complex control systems are required.• Coupling by direct contact with a liquid couplant, or via a rigid wedge or a delay line with liquid couplant at the interfaces: This coupling requires simpler control systems for the inspection, but the homogeneity of the couplant film and attenuation in the wedges deteriorate the signal. The geometry of the inspected part can make the coupling more difficult to setup, particularly if the surface is complex or varies from one point to another. The problem becomes critical when the dimensions of the transducer are large in comparison with the local curvature of the interface. The use of transducers that are flexible, or that are fitted with a flexible wedge, improves the quality of the coupling for components with complex or variable geometry, and in some cases, makes it possible to do certain inspections that currently have no solution. This article presents the recent developments and results obtained in the context of transducers with flexible wedges, in particular: • Design options; • Flexible membranes and mechanical interfaces development for PA transducers; • Mechanical supports development for manual or automated use; • Acoustic performance, and wear resistance tests; These studies have demonstrated the contribution of flexible wedge transducers to various applications, with acoustic performances similar to that of immersion and easy implementation comparable to standard contact inspections, while remaining compatible with an industrial use. The detailed results will be presented, as well as the possibilities for the future developments of transducers with flexible wedges

Feeding and rearing techniques used for larvae of Pleurodeles waltl (urodele amphibian) onboard the MIR space station

A research group in our laboratories works on development of amphibians under microgravity conditions. Several experiments were performed in space conditions using embryos or adults of the urodele amphibian, Pleurodeles waltl (Bautz et al., 1995; Dournon et al., 1997; Husson et al., 1998; Duprat et al., 1998; Aimar et al., 2000). In 1999, for the so-called Perseus French space mission onboard the MIR space station, the project was to rear embryos and larvae of Pleurodeles waltl in microgravity conditions to study the appearance and evolution of otoconia in the inner ear (Oukda et al., 1999a and b). The present paper reports the technique used to feed and rear Pleurodeles larvae in microgravity conditions with the assistance of a cosmonaut

DEVELOPMENT AND REPRODUCTION OF SALAMANDERS (URODELE AMPHIBIAN) HATCHED ONBOARD THE MIR SPACE STATION

In France many scientifics work in meteorology and correspond with Louis COTTE in Paris. After Alsace, Lorraine, Champagne and Ardennes this paper descrives the meteorology of Bourgogne. Many observations to «Société Royale de Médecine», «Académie Royale des Sciences» and «Société Royale d’Agriculture» show the climatical changes of the large and variable region.En France, beaucoup de scientifiques du XVIII ème siècle poursuivent des travaux en météorologie et correspondent avec Louis COTTE de Paris. Après l’Alsace, la Lorraine, la Champagne et les Ardennes, nous abordons la météorologie de la Bourgogne. Beaucoup d’observations météorologiques relatées par la Société Royale de Médecine, l ‘Académie Royale des Sciences et la Société Royale d’Agriculture décrivent les variations climatiques de cette région importante, très variée et d’une vaste superficie

Implication of free fatty acids in thrombin generation and fibrinolysis in vascular inflammation in Zucker rats and evolution with aging

Background: The metabolic syndrome (MetS) and aging are associated with modifications in blood coagulation factors, vascular inflammation, and increased risk of thrombosis. Objectives: Our aim was to determine concomitant changes in thrombin generation in the blood compartment and at the surface of vascular smooth muscle cells (VSMCs) and its interplay with adipokines, free fatty acids (FFA), and metalloproteinases (MMPs) in obese Zucker rats that share features of the human MetS. Methods: Obese and age-matched lean Zucker rats were compared at 25 and 80 weeks of age. Thrombin generation was assessed by calibrated automated thrombography (CAT). Results: Endogenous thrombin potential (ETP) was increased in obese rats independent of platelets and age. Clot half-lysis time was delayed with obesity and age. Interleukin (IL)-1β and IL-13 were increased with obesity and age respectively. Addition of exogenous fibrinogen, leptin, linoleic, or palmitic acid increased thrombin generation in plasma whereas adiponectin had an opposite effect. ETP was increased at the surface of VSMCs from obese rats and addition of exogenous palmitic acid further enhanced ETP values. Gelatinase activity was increased in aorta at both ages in obese rats and MMP-2 activity was increased in VSMCs from obese rats. Conclusions: Our study demonstrated in MetS an early prothrombotic phenotype of the blood compartment reinforced by procoagulant properties of dedifferentiated and inflammatory VSMCs. Mechanisms involved (1) increased fibrinogen and impaired fibrinolysis and (2) increased saturated fatty acids responsible for additive procoagulant effects. Whether specifically targeting this hypercoagulability using direct thrombin inhibitors would improve outcome in MetS is worth investigating

Scientific Opinion on the public health hazards to be covered by inspection of meat from farmed game

Salmonella spp. in farmed wild boar and Toxoplasma gondii in farmed deer and farmed wild boar were ranked as a high priority for meat inspection. Trichinella spp. in wild boar was ranked as low priority due to current controls, which should be continued. For chemical hazards, all substances were ranked as medium or lower potential concern. More effective control of biological hazards could be achieved using an integrated farm to chilled carcass approach, including improved food chain information (FCI) and risk-based controls. Further studies are required on Salmonella spp. in farmed wild boar and T. gondii in farmed wild boar and farmed deer. If new information confirms a high risk to public health from meat from these species, setting targets at carcass level should be considered. Palpation and incision should be omitted, as it will not detect biological hazards considered to be a high priority for meat inspection while increasing the potential spread and cross-contamination of the carcasses with Salmonella. Palpation and/or incision may be applied where abnormalities have been detected but away from the slaughter line. However the elimination of routine palpation and incision would be detrimental for detecting tuberculosis. As farmed deer and farmed wild boar can act as tuberculosis reservoirs, any reduction in the detection, due to changes in the post-mortem inspection procedures, will have consequences for the overall surveillance of tuberculosis. Monitoring programmes for chemical hazards should be more flexible and based on the risk of occurrence, taking into account FCI, which should be expanded to reflect the specific environmental conditions of the farms where the animals are reared, and the ranking of chemical substances, which should be regularly updated and include new hazards. Control programmes across the food chain, national residue control programmes, feed control and monitoring of environmental contaminants should be better integrated

Hypercoagulability associated with antiphospholipid antibodies : descrriptive and mechanistic approaches

L’objectif était d’identifier le ou le(s) mécanismes contribuant à l’hypercoagulabilité associée aux anticorps anti-phospholipides. L’activation plaquettaire induite par les anticorps ainsi que l’interférence des complexes anticorps/antigène avec les réactions dépendantes des phospholipides ont été étudiées. Des anticorps monoclonaux murins dirigés contre la ß2-glycoproteine I et la prothrombine ont été utilisés comme modèle des anticorps anti-phospholipides. Les résultats obtenus montrent que ces anticorps ont un effet anticoagulant qui se traduit par une diminution de la génération de thrombine et un effet procoagulant qui se traduit par une inhibition de l’activité de la protéine C activée. Ces anomalies surviennent indépendamment de l’activation plaquettaire. La résultante globale est une hypercoagulabilité. Une activation plaquettaire, suffisamment intense, augmente la quantité de phospholipides procoagulants et neutralise partiellement l’effet anticoagulant des anticorps anti-phospholipides. Ainsi, l’activation plaquettaire contribue à renforcer l’hypercoagulabilité due à la résistance à la protéine C activée. Les complexes anticorps/antigène interfèrent avec les complexes pro- et anticoagulants au niveau des surfaces plaquettaires. Les avidités respectives de chacun des partenaires étudiés pour les surfaces phospholipidiques participent aux mécanismes conduisant à l'hypercoagulabilité associée aux anticorps anti-phospholipides.The objective was to identify the mechanisms which contribute to the hypercoagulability associated with anti-phospholipid antibodies. Antibody-mediated platelet activation and interference of antibodies with phospholipid-dependent reactions were investigated. Murine monoclonal antibodies directed against ß2-glycoprotein I and prothrombin were used as model of anti-phospholipid antibodies. An anticoagulant effect, evidenced by impairment of thrombin generation and a procoagulant effect, by inhibition of activated protein C activity were shown. These phenomena occurs independently of platelet activation. The overall result was hypercoagulability. When immune-mediated platelet activation is sufficiently intense, it increases the amount of procoagulant phospholipids and antagonizes partially the anticoagulant effect of anti-phospholipid antibodies. Thus platelet activation contributes to reinforce the hypercoagulability due to activated protein C resistance. The antibody/antigen complexes interfere with pro- and anticoagulant complexes to the platelet surfaces. The avidity of each studied partners for the phospholipid surfaces take part in the mechanisms leading to hypercoagulability associated with antiphospholipid antibodies

Hypercoagulabilité associée aux anticorps anti-phospholipides : approches descriptives et mécanistiques

The objective was to identify the mechanisms which contribute to the hypercoagulability associated with anti-phospholipid antibodies. Antibody-mediated platelet activation and interference of antibodies with phospholipid-dependent reactions were investigated. Murine monoclonal antibodies directed against ß2-glycoprotein I and prothrombin were used as model of anti-phospholipid antibodies. An anticoagulant effect, evidenced by impairment of thrombin generation and a procoagulant effect, by inhibition of activated protein C activity were shown. These phenomena occurs independently of platelet activation. The overall result was hypercoagulability. When immune-mediated platelet activation is sufficiently intense, it increases the amount of procoagulant phospholipids and antagonizes partially the anticoagulant effect of anti-phospholipid antibodies. Thus platelet activation contributes to reinforce the hypercoagulability due to activated protein C resistance. The antibody/antigen complexes interfere with pro- and anticoagulant complexes to the platelet surfaces. The avidity of each studied partners for the phospholipid surfaces take part in the mechanisms leading to hypercoagulability associated with antiphospholipid antibodies.L'objectif était d'identifier le ou le(s) mécanismes contribuant à l'hypercoagulabilité associée aux anticorps anti-phospholipides. L'activation plaquettaire induite par les anticorps ainsi que l'interférence des complexes anticorps/antigène avec les réactions dépendantes des phospholipides ont été étudiées. Des anticorps monoclonaux murins dirigés contre la ß2-glycoproteine I et la prothrombine ont été utilisés comme modèle des anticorps anti-phospholipides. Les résultats obtenus montrent que ces anticorps ont un effet anticoagulant qui se traduit par une diminution de la génération de thrombine et un effet procoagulant qui se traduit par une inhibition de l'activité de la protéine C activée. Ces anomalies surviennent indépendamment de l'activation plaquettaire. La résultante globale est une hypercoagulabilité. Une activation plaquettaire, suffisamment intense, augmente la quantité de phospholipides procoagulants et neutralise partiellement l'effet anticoagulant des anticorps anti-phospholipides. Ainsi, l'activation plaquettaire contribue à renforcer l'hypercoagulabilité due à la résistance à la protéine C activée. Les complexes anticorps/antigène interfèrent avec les complexes pro- et anticoagulants au niveau des surfaces plaquettaires. Les avidités respectives de chacun des partenaires étudiés pour les surfaces phospholipidiques participent aux mécanismes conduisant à l'hypercoagulabilité associée aux anticorps anti-phospholipides

Etude de l'ostéogenèse dans différentes conditions expérimentales

Non disponible / Not availableL'histologie osseuse a fait d'incontestables progrès grâce à l'inclusionen résine plastique sans décalcification et à l'étude histomorphométriquedes paramètres dynamiques. Le but de ce travail est d'appliquer ces techniques à l'illustration de quelques aspects de la construction et de la reconstruction osseuses. La croissance de l'os de l'enfant est sous la dépendance de nombreuxparamètres. L'altération de l'un d'entre eux se traduit par un profil histomorphométrique en rapport avec son expression clinique. La consolidation des fractures diaphysaires constitue un retour à l'ostéogénèse. L'ossification du cal interne est endoconjonctive, celle du cal externe mixte endoconjonctive et endochondrale. La régénération osseuse en distraction procède d'un mécanisme différent : la zone centrale est fibreuse et subit l'ossification endoconjonctiveparallèlement à l'allongement. Les antimitotiques perturbent modérémentle processus ct'ostéogénèse