Cloud file sharing using PREaaS

This paper proposes a new method of features extraction for handwritten, printed and isolated numeral recognition. It is essential today for a company to store its data in an encrypted way when it uses Cloud Computing. However, the manipulation of this encrypted data remains complex, and it is very difficult in this case to be able to share the encrypted data between different users. One of the solutions for sharing encrypted data is to use PRE (Proxy Reencryption) which allows both the re-encryption of the data, but also the delegation of this operation by a third party via the use of a specific key. In this article, we propose a solution for sharing encrypted files between users that uses a classic storage system in the Cloud and PRE (re-encryption PRoxy). We present an improvement of an existing PRE algorithm by applying it to elliptical curves in order to improve its performance. Finally, we implement this architecture in the form of a cloud service called PREaaS (PRE as a Service) which allows this mechanism to be used on demand with an API

Tégée/Nikli et la période byzantine

E. ØstbyInternational audienc

La diplomatie médio-byzantine et l’Antiquité

Il est bien connu que Byzance jouit d’un héritage ancien considérable, dont le sens exact ne lui est plus toujours compréhensible d’ailleurs. Venant compléter d’autres études antérieures, cet article fait le point sur les différentes manières avec lesquelles les autorités byzantines ont pu employer cet héritage dans leur activité diplomatique, entre les viiie et xiie siècles. C’est tout d’abord le patrimoine visible, architectural et monumental qu’elles ont pu exposer à des délégations étrangères et hôtes de marque. Le poids des manuscrits échangés dans le cadre de la politique extérieure de l’Empire est ensuite appréhendé. S’il paraît important dans le cadre des relations avec l’Islam, il semble le devenir progressivement dans les contacts avec l’Occident chrétien. Quelques éléments conduisent à voir en ces manuscrits provenant de la cour impériale une arme possible dans les tractations diplomatiques. Enfin, d’autres aspects dans nos sources mettent en évidence les liens récurrents entre la diplomatie médio-byzantine et l’Antiquité.It is a well-known fact that Byzantium enjoyed a rich ancient heritage, the exact meaning of which was by the way not always comprehensible to her. Coming as a complement to other previous studies, this article sums up the various ways in which the Byzantine authorities may have used that heritage in their diplomatic activity between the VIIIth and XIIth centuries. First and foremest it was the visible heritage, architectural and monumental, they are likely to have exhibited to foreign delegations and distinguished visitors. The weight of the exchanged manuscripts within the framework of the Empire’s foreign policy is then examined. While it seems important in the relationships with Islam, it looks as if it gradually grew in importance in the contacts with the Christian West. Some elements lead one to see in those manuscripts from the Imperial court a likely weapon in the diplomatic transactions. Lastly, other aspects of our sources set into prominence the recurrent links between medio-Byzantine diplomacy and Antiquity

La diplomatie médio-byzantine et l’Antiquité

Il est bien connu que Byzance jouit d’un héritage ancien considérable, dont le sens exact ne lui est plus toujours compréhensible d’ailleurs. Venant compléter d’autres études antérieures, cet article fait le point sur les différentes manières avec lesquelles les autorités byzantines ont pu employer cet héritage dans leur activité diplomatique, entre les viiie et xiie siècles. C’est tout d’abord le patrimoine visible, architectural et monumental qu’elles ont pu exposer à des délégations étrangères et hôtes de marque. Le poids des manuscrits échangés dans le cadre de la politique extérieure de l’Empire est ensuite appréhendé. S’il paraît important dans le cadre des relations avec l’Islam, il semble le devenir progressivement dans les contacts avec l’Occident chrétien. Quelques éléments conduisent à voir en ces manuscrits provenant de la cour impériale une arme possible dans les tractations diplomatiques. Enfin, d’autres aspects dans nos sources mettent en évidence les liens récurrents entre la diplomatie médio-byzantine et l’Antiquité.It is a well-known fact that Byzantium enjoyed a rich ancient heritage, the exact meaning of which was by the way not always comprehensible to her. Coming as a complement to other previous studies, this article sums up the various ways in which the Byzantine authorities may have used that heritage in their diplomatic activity between the VIIIth and XIIth centuries. First and foremest it was the visible heritage, architectural and monumental, they are likely to have exhibited to foreign delegations and distinguished visitors. The weight of the exchanged manuscripts within the framework of the Empire’s foreign policy is then examined. While it seems important in the relationships with Islam, it looks as if it gradually grew in importance in the contacts with the Christian West. Some elements lead one to see in those manuscripts from the Imperial court a likely weapon in the diplomatic transactions. Lastly, other aspects of our sources set into prominence the recurrent links between medio-Byzantine diplomacy and Antiquity

Absolute localisations in indoor environment based on omnidirectionnal vision

In this article, we present two localization methods based on the omnidirectional SYCLOP sensor. The first method is a static one and is based on a matching between one real image and a base of synthetics panoramic pictures. This base is computed with the help of a modelling and a calibration of the SYCLOP sensor. The second method is a dynamic one and is based on multi target tracking. The originality of this method is its capability to manage and propagate uncertainties during the localization process. This multi-level uncertainty propagation stage is based on the use of the Dempster-Shafer theory. In this work, SYCLOP is associated with a panoramic range finder. It enables to treat complementary and redundant data and thus to construct a robust sensorial model which integrates an important number of significant primitives. Based on this model, we treat the problem of maintaining a matching and propagating uncertainties on each matched primitive in order to obtain a global uncertainty about the robot configuration.Dans cet article, nous présentons deux méthodes de localisation basées sur l'utilisation du capteur omnidirectionnel SYCLOP. La première méthode, statique, consiste à rechercher la configuration du robot d'une manière absolue par la mise en correspondance d'une image réelle avec une base d'images panoramiques synthétiques. Cette base est obtenue grâce à la modélisation et la calibration du capteur SYCLOP. La deuxième méthode, dynamique, est basée sur de la poursuite multi-cibles. L'originalité de cette méthode réside dans sa capacité à gérer et propager des incertitudes durant le processus de localisation. Cette propagation multi-niveaux d'incertitudes est basée sur l'utilisation de la théorie de Dempster Shafer. Dans ce travail, SYCLOP est associé à un capteur de profondeur. Ceci permet de traiter des données à la fois complémentaires et redondantes et donc de construire un modèle sensoriel robuste intégrant un nombre important de primitives significatives. En nous appuyant sur ce modèle, nous traitons le problème de maintien d'un appariement et de la propagation d'une incertitude sur chaque primitive appariée, ceci dans le but d'obtenir une incertitude globale qui caractérise l'estimation de configuration du robot

Combination of optison with ultrasound and electroporation increases albumin and thrompoietin transgene expression whilst elongation factor promoter prolongs its duration

Hypoalbuminaemia and thrombocytopaenia are two clinical problems frequently encountered in patients with chronic liver failure or cancer following treatment with chemotherapy. The current study was designed to assess the magnitude and duration of thrombopoietin and albumin transgene expression hoping to increase the production of albumin and platelets. Immunocompetent and immunocompromised (nude) mice were injected intramuscularly with plasmids expressing either human serum albumin or human thrombopoietin. The therapeutic expression cassette of the plasmids was driven by either CMV or elongation factor 1- promoters respectively. In order to achieve muscle specific expression both gene constructs included the myosin light chain enhancer. The experiment was conducted in a group of mice which were injected with the transgene plasmid either in normal saline or plasmid followed by electroporation, ultrasound, optison and a combination of all three to increase transgene expression. The result showed that plasmids with the CMV promoter induced the highest transgenic expression lasting for one week whilst plasmids with the elongation factor 1-alpha promoter produced a weaker expression lasting for a longer and more stable duration of expression up to 3 months in both immunocompetent and nude mice. The combination of electroporation and ultrasound with Optison TM provided the highest transgene expression. We concluded that it would be possible to increase albumin and platelets production by an intramuscular injection of plasmids expressing human albumin and thromopoietin. A combination of electroporation and ultrasound with Optison TM can increase their expression

Natural Occurrence of 2′,5′-Linked Heteronucleotides in Marine Sponges

2′,5′-oligoadenylate synthetases (OAS) as a component of mammalian interferon-induced antiviral enzymatic system catalyze the oligomerization of cellular ATP into 2′,5′-linked oligoadenylates (2-5A). Though vertebrate OASs have been characterized as 2′-nucleotidyl transferases under in vitro conditions, the natural occurrence of 2′,5′-oligonucleotides other than 2-5A has never been demonstrated. Here we have demonstrated that OASs from the marine sponges Thenea muricata and Chondrilla nucula are able to catalyze in vivo synthesis of 2-5A as well as the synthesis of a series 2′,5′-linked heteronucleotides which accompanied high levels of 2′,5′-diadenylates. In dephosphorylated perchloric acid extracts of the sponges, these heteronucleotides were identified as A2′p5′G, A2′ p5′U, A2′p5′C, G2′p5′A and G2′ p5′U. The natural occurrence of 2′-adenylated NAD+ was also detected. In vitro assays demonstrated that besides ATP, GTP was a good substrate for the sponge OAS, especially for OAS from C. nucula. Pyrimidine nucleotides UTP and CTP were also used as substrates for oligomerization, giving 2′,5′-linked homo-oligomers. These data refer to the substrate specificity of sponge OASs that is remarkably different from that of vertebrate OASs. Further studies of OASs from sponges may help to elucidate evolutionary and functional aspects of OASs as proteins of the nucleotidyltransferase family