226 research outputs found

    Transfert sécurisée d'une RI sans perte par une méthode d'insertion de données robuste à la compression JPEG

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    Dans cet article, nous prĂ©sentons une mĂ©thode d'insertion de donnĂ©es cachĂ©es originale permettant de protĂ©ger la haute rĂ©solution d'une rĂ©gion d'intĂ©rĂȘt. Les pertes de rĂ©solution dans la rĂ©gion d'intĂ©rĂȘt sont rĂ©cupĂ©rĂ©es puis insĂ©rĂ©es par marquage dans l'image. L'image avec la rĂ©gion d'intĂ©rĂȘt sans perte sera visible seulement aprĂšs l'extraction et la reconstruction de celle-ci. La mĂ©thode d'insertion s'appuie sur les coefficients DCT et sur la modification de la matrice de quantification. Cette technique a Ă©tĂ© dĂ©veloppĂ©e de maniĂšre Ă  ĂȘtre robuste Ă  la compression JPEG

    Data Hiding Based on Connectivity Modification of 3D Mesh

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    Day by day, the amount of digital data has been rapidly increasing on the Internet. The size of 3D objects is very large and these objects need fast transmissions. Moreover, 3D data security becomes increasingly important for many applications, e.g., confidential transmission, video surveillance, military and medical applications. In this paper we present two new approaches of 3D object data hiding without changing the position of vertices in the 3D space. The main idea of the two proposed methods is to find and to synchronize particular areas of the 3D objects used to embed the message. The embedding is done by changing the connectivity of edges in the selected areas composed of quadrangles. The first proposed approach of data hiding in 3D objects is based on minimum spanning tree (MST) while the second approach is based on the projection on a secret axis of the quadrangle centers. These methods are lossless in the sense that the positions of the vertices are unchanged. Moreover they are blind and do not depend of the order of the data in the files. These two approaches are very interesting when the 3D objects have been digitalized with high precision.De nos jours, des visualisations ainsi que des transferts d’objets 3D sont couramment effectuĂ©s pour de nombreuses applications allant du jeu vidĂ©o Ă  l’imagerie mĂ©dicale en passant par l’industrie manufacturiĂšre. Dans cet article nous proposons deux nouvelles mĂ©thodes permettant de dissimuler des donnĂ©es dans des objets 3D sans modifier la position des sommets. L’idĂ©e principale des deux mĂ©thodes prĂ©sentĂ©es est de trouver et de synchroniser des zones particuliĂšres dans l’objet 3D pouvant ĂȘtre utilisĂ©es pour insĂ©rer le message. L’insertion de donnĂ©es s’appuie sur la modification de la connexitĂ© des arĂȘtes dans les zones sĂ©lectionnĂ©es composĂ©es de quadrangles. La diffĂ©rence entre les deux mĂ©thodes prĂ©sentĂ©es est la maniĂšre de sĂ©lectionner et de synchroniser ces zones d’insertion. Alors que la premiĂšre mĂ©thode s’appuie sur un arbre couvrant minimum (ACM), la seconde mĂ©thode utilise un axe sur lequel sont projetĂ©s les centres des zones d’insertion. Ces deux mĂ©thodes aveugles, protĂ©gĂ©es par utilisation de clefs secrĂštes, rĂ©sistent Ă  des transformations gĂ©omĂ©triques tels que les rotations, translations ou changement d’échelle et ne sont pas perturbĂ©es par des modifications directes de l’ordre des donnĂ©es dans les fichiers originaux. Ces approches trouvent un intĂ©rĂȘt certain pour des objets 3D dont les sommets ont Ă©tĂ© acquis avec une grande prĂ©cision et dont la modification n’est pas acceptable

    Left atrial decompression through unidirectional left-to-right interatrial shunt for the treatment of left heart failure : first-inman experience with the V-Wave device

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    Aims: Elevated filling pressures of the left atrium (LA) are associated with poorer outcomes in patients with chronic heart failure. The V-Wave is a new percutaneously implanted device intended to decrease the LA pressure by the shunting of blood from the LA to the right atrium. This report describes the first-in-man experience with the V-Wave device. Methods and results: A 70-year-old man with a history of heart failure of ischaemic origin, left ventricular dysfunction (LVEF: 35%, pulmonary wedge: 19 mmHg), no right heart dysfunction, NYHA Class III and orthopnoea despite optimal treatment, was accepted for V-Wave device implantation. The device consists of an ePTFE encapsulated nitinol frame that is implanted at the level of the interatrial septum and contains a trileaflet pericardium tissue valve sutured inside which allows a unidirectional LA to right atrium shunt. The procedure was performed through a transfemoral venous approach under fluoroscopic and TEE guidance. The device was successfully implanted and the patient was discharged 24 hours after the procedure with no complications. At three-month follow-up a left-to-right shunt through the device was confirmed by TEE. The patient was in NYHA Class II, without orthopnoea, the Kansas City Cardiomyopathy index was 77.6 (from 39.1 at baseline) and NT-proBNP was 322 ng/mL (from 502 ng/mL at baseline). The QP/QS was 1.17 and the pulmonary wedge was 8 mmHg, with no changes in pulmonary pressure or right ventricular function. Conclusions: Left atrial decompression through a unidirectional left-to-right interatrial shunt represents a new concept for the treatment of patients with left ventricular failure. The present report shows the feasibility of applying this new therapy with the successful and uneventful implantation of the V-Wave device, which was associated with significant improvement in functional, quality of life and haemodynamic parameters at 90 days

    Resumeq: A Novel Way of Monitoring Equine Diseases Through the Centralization of Necropsy Data

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    The French surveillance network for causes of equine mortality (Resumeq) was created in 2015 for the qualitative surveillance of equine mortality through the centralization in a national database of necropsy data and their subsequent epidemiological analysis. It was designed to identify the causes of equine mortality, monitor their evolution over time and space, and detect emerging diseases as early as possible. Resumeq is an event-based surveillance system involving various players and structures. It is organized around a steering body, a scientific and technical support committee and a coordination unit. Different tools have been developed specifically for Resumeq. These include standardized necropsy protocols, a thesaurus for the anatomopathological terms and the causes of equine death, and an interactive web application so that network contributors can display data analysis results. The four French veterinary schools, seventeen veterinary laboratories, and ten veterinary clinics already contribute to the production and centralization of standardized data. To date, the data from around 1,000 equine necropsies have been centralized. While most deaths were located in western France, the geographic coverage is gradually improving. Data analysis allows the main causes of death to be ranked and major threats identified on a local, regional or national level. Initial results demonstrate the feasibility and benefits of this national surveillance tool. Moreover, in the future, this surveillance could take an international dimension if several countries decided to jointly capitalize on their necropsy data

    Myocardial injury following transcatheter aortic valve implantation : insights from delayed-enhancement cardiovascular magnetic resonance

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    Aims: The aim of this study was to evaluate the presence, localisation and extent of myocardial injury as determined by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging in patients undergoing transcatheter aortic valve implantation (TAVI). Methods and results: A total of 37 patients, who underwent successful TAVI with a balloon-expandable valve (transapical [TA], n=11; non-TA, n=26), were included. Cardiac biomarker (CK-MB and cTnT) lev- els were determined at baseline and following TAVI. CMR was performed within a week before and within 30 days following TAVI. Some increase in cardiac biomarkers was detected in 97% of the patients as deter- mined by a rise in cTnT, and in 49% of the patients as determined by a rise in CK-MB. Following TAVI, no new myocardial necrosis defects were observed with the non-TA approach. Nonetheless, all patients who underwent TAVI through the TA approach had new focal myocardial necrosis in the apex, with a median myo-cardial extent and necrotic mass of 5% [2.0-7.0] and 3.5 g [2.3-4.5], respectively. Conclusions: Although some increase in cardiac biomarkers of myocardial injury was systematically detected following TAVI, new myocardial necrosis as evaluated by CMR was observed only in patients undergoing the procedure through the TA approach, involving ~5% of the myocardium in the apex

    Defining the scope of the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet): a bottom-up and One Health approach

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    Background Building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet) was proposed to strengthen the European One Health antimicrobial resistance (AMR) surveillance approach. Objectives To define the combinations of animal species/production types/age categories/bacterial species/specimens/antimicrobials to be monitored in EARS-Vet. Methods The EARS-Vet scope was defined by consensus between 26 European experts. Decisions were guided by a survey of the combinations that are relevant and feasible to monitor in diseased animals in 13 European countries (bottom-up approach). Experts also considered the One Health approach and the need for EARS-Vet to complement existing European AMR monitoring systems coordinated by the ECDC and the European Food Safety Authority (EFSA). Results EARS-Vet plans to monitor AMR in six animal species [cattle, swine, chickens (broilers and laying hens), turkeys, cats and dogs], for 11 bacterial species (Escherichia coli, Klebsiella pneumoniae, Mannheimia haemolytica, Pasteurella multocida, Actinobacillus pleuropneumoniae, Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus hyicus, Streptococcus uberis, Streptococcus dysgalactiae and Streptococcus suis). Relevant antimicrobials for their treatment were selected (e.g. tetracyclines) and complemented with antimicrobials of more specific public health interest (e.g. carbapenems). Molecular data detecting the presence of ESBLs, AmpC cephalosporinases and methicillin resistance shall be collected too. Conclusions A preliminary EARS-Vet scope was defined, with the potential to fill important AMR monitoring gaps in the animal sector in Europe. It should be reviewed and expanded as the epidemiology of AMR changes, more countries participate and national monitoring capacities improve.Peer reviewe

    Characterization and Management of Stable Coronary Artery Disease in Patients Undergoing Transcatheter Aortic Valve Implantation.

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    Background/Objectives: To date, data regarding the characteristics and management of obstructive, stable coronary artery disease (CAD) encountered in patients undergoing transcatheter aortic valve implantation (TAVI) are sparse. The aim of the study was to analyze granular details, treatment, and outcomes of patients undergoing TAVI with obstructive, stable CAD from real-world practice. Methods: REVASC-TAVI (Management of myocardial REVASCularization in patients undergoing Transcatheter Aortic Valve Implantation with coronary artery disease) is an investigator-initiated, multicenter registry, which collected data from patients undergoing TAVI with obstructive stable CAD found during the pre-TAVI work-up. Results: A total of 2025 patients from 30 centers worldwide with complete follow-up were included in the registry. Most patients had single-vessel CAD (56.1%). An involvement of proximal coronary tracts was detected in 62.5% of cases, with 12.0% of patients having CAD in left main (LM). Most patients received percutaneous coronary intervention (PCI) (n = 1617, 79.9%), especially those with proximal CAD (90.4%). At 2 years, the rates of all-cause death [Kaplan-Meier (KM) estimates 20.1% vs. 18.8%, plog-rank = 0.86] and of the composite of all-cause death, stroke, myocardial infarction, and rehospitalization for heart failure (KM estimates 29.7% vs. 27.5%, plog-rank = 0.82) did not differ between patients undergoing PCI and those who were not. Conclusions: Patients undergoing TAVI with obstructive CAD more commonly had a single-vessel disease and an involvement of proximal coronary tracts. They were commonly treated with PCI, with similar outcomes compared to those treated conservatively
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