145 research outputs found
Cloud computing applied to multi-modal treatment of in situ images for analyzing environmental dynamics
No full textL’analyse des paysages, de ses dynamiques et ses processus environnementaux, nécessite d’acquérir régulièrement des données des sites, notamment pour le bilan glaciaire au Spitsberg et en haute montagne. A cause des mauvaises conditions climatiques communes aux latitudes polaires et à cause de leur coût, les images satellites journalières ne sont pas toujours accessibles. De ce fait, les événements rapides comme la fonte de la neige ou l'enneigement ne peuvent pas être étudiés à partir des données de télédétection à cause de leur fréquence trop faible. Nous avons complété les images satellites par un ensemble de de stations photo automatiques et autonomes qui prennent 3 photos par jour. L’acquisition de ces photos génère une grande base de données d’images. Plusieurs traitements doivent être appliqués sur les photos afin d’extraire l’information souhaitée (modifications géométriques, gestion des perturbations atmosphériques, classification, etc). Seule l’informatique est à même de stocker et gérer toutes ces informations. Le cloud computing offre en tant que services des ressources informatiques (puissance de calcul, espace de stockage, applications, etc). Uniquement le stockage de la masse de données géographique pourrait être une raison d’utilisation du cloud computing. Mais en plus de son espace de stockage, le cloud offre une simplicité d’accès, une architecture scalable ainsi qu’une modularité dans les services disponibles. Dans le cadre de l’analyse des photos in situ, le cloud computing donne la possibilité de mettre en place un outil automatique afin de traiter l’ensemble des données malgré la variété des perturbations ainsi que le volume de données. A travers une décomposition du traitement d’images en plusieurs tâches, implémentées en tant que web services, la composition de ces services nous permet d’adapter le traitement aux conditions de chacune des données.Analyzing landscape, its dynamics and environmental evolutions require regular data from the sites, specifically for glacier mass balanced in Spitsbergen and high mountain area. Due to poor weather conditions including common heavy cloud cover at polar latitudes, and because of its cost, daily satellite imaging is not always accessible. Besides, fast events like flood or blanket of snow is ignored by satellite based studies, since the slowest sampling rate is unable to observe it. We complement satellite imagery with a set of ground based autonomous automated digital cameras which take 3 pictures a day. These pictures form a huge database. Each picture needs many processing to extract the information (geometric modifications, atmospheric disturbances, classification, etc). Only computer science is able to store and manage all this information. Cloud computing, being more accessible in the last few years, offers as services IT resources (computing power, storage, applications, etc.). The storage of the huge geographical data could, in itself, be a reason to use cloud computing. But in addition to its storage space, cloud offers an easy way to access , a scalable architecture and a modularity in the services available. As part of the analysis of in situ images, cloud computing offers the possibility to set up an automated tool to process all the data despite the variety of disturbances and the data volume. Through decomposition of image processing in several tasks, implemented as web services, the composition of these services allows us to adapt the treatment to the conditions of each of the data
Structure des analyses syntaxiques catégorielles (Application à l'inférence grammaticale)
No full textEn linguistique informatique, les structures des analyses syntaxiques catégorielles offrent une interface syntaxe sémantique directe et permettent l'apprentissage de grammaires à partir de phrases syntaxiquement correctes. Dans cette thèse, nous étudierons ces structures d'analyse pour les grammaires catégorielles de Lambek. Nous proposerons tout d'abord une transformation de ces structures vers des structures d'analyse dans les grammaires catégorielles classiques, en augmentant le nombre de types associés aux entrées lexicales. Nous en déduirons une sous-classe de grammaires de Lambek non associatives apprenable à partir d'exemples positifs. Nous montrerons enfin que la plupart des autres sous-classes de grammaires de Lambek ne sont pas apprenables à partir d'exemples positifs non structurés.RENNES1-BU Sciences Philo (352382102) / SudocLENS-CRIL (624982203) / SudocSudocFranceF
Temperature-dependent NIR-CPL spectra of chiral Yb(III) complexes
No full textChiral, enantiopure Yb(III) complexes are able to emit circularly polarized luminescence (CPL) in the near infrared (NIR) wavelength region, quantified by the dissymmetry factor (glum). Due to crystal field splitting (CFS), the excited state 2F5/2 consists of three mj\u27 sublevels, which are populated in accordance with the Boltzmann distribution. Consequently, room temperature CPL spectra are the sum of various - either positive or negative – contributions, that are practically impossible to quantify. Thanks to the use of an advanced setup enabling CPL measurements over a range of temperatures (300 to 4 K), the interrelation of CFS, glum and temperature was demonstrated on the example of a pair of enantiopure Yb(III) com-plexes. It was thereby confirmed that each mJ’ sublevel gives an independent contribution to the overall CPL spectrum. Hence, the CPL spectra of chiral lanthanide complexes were found to be indeed strongly temperature-dependent, as is the glum dissymmetry factor, as a consequence of the variation in thermal sublevel population. These results were additional-ly interpreted in the framework of multireference wave-function calculations
Biocompatible nanoparticles containing hydrophobic nickel-bis(dithiolene) complexes for NIR-mediated doxorubicin release and photothermal therapy
No full textInternational audienceBiocompatible nanoparticles (NPs) constituted by amphiphilic poly(ethylene glycol)-block-poly(benzyl malate), PEG-b-PMLABe, have been designed for site-specific PhotoThermal Controlled Release (PTCR) of drugs thanks to the presence of a near infra-red (NIR) photothermally active nickel-bis(dithiolene) complex in the inner core of the NPs, together with doxorubicin (Dox). A nanoprecipitation technique was used to prepare well-defined nickel-bis(dithiolene) and nickel-bis(dithiolene)/Dox loaded NPs, which were characterized by dynamic light scattering (DLS), zeta-potential measurements and Transmission Electron Microscopy (TEM). We have shown that the Dox release was effectively controlled by NIR irradiation (long or pulsed NIR laser irradiation). Cytotoxicity experiments on HeLa and MDA-MB-231 cells have shown that the incorporation of more than 10 w% of nickel-bis(dithiolene) complexes does not increase the intrinsic toxicity of the polymer nanoparticles. Finally, the viability of MDA-MB-231 cells was assessed after their incubation, for 24 hours, with empty NPs, Ni4C(12) loaded NPs, Dox loaded NPs or Ni4C(12)/Dox loaded NPs, without or with NIR irradiation. Above all, the results have highlighted that the Ni4C(12) loaded NPs after 5 min NIR laser irradiation can induce strong cell death up to 80% at 50 g mL(-1). These results demonstrate that these NPs are good candidates for photothermal therapy
Fine and Clean Photothermally Controlled NIR Drug Delivery from Biocompatible Nickel-bis(dithiolene)-Containing Liposomes
No full textInternational audienceThis work demonstrates that metal-bis(dithiolene) complexes can be efficiently incorporated inside organic nanocarriers and, that under near-infrared (NIR) irradiation, their high photothermal activity can be finely used to release encapsulated drugs on demand. In contrast to gold nanoparticles and other organic NIR dyes, nickel-bis(dithiolene) complexes do not produce singlet oxygen under irradiation, a highly desirable characteristic to preserve the chemical integrity and activity of the loaded drug during the NIR-triggered release from the nanocarriers. Finally, cytotoxicity experiments performed on various cell lines have shown that the incorporation of such metal complexes do not increase the toxicity of the final liposomal formulation. These results offer great promise for the development of innovative biocompatible drug nanocargos that are able to safely deliver their content on demand under NIR laser irradiation. Moreover, this work demonstrates that metal-bis(dithiolene) complexes, owing to their versatility of functionalization and metal complexation, are attractive photothermal agents for the development of original NIR-responsive materials for application not only in biotechnology but also in materials science
Copyright, contratto e accesso alla conoscenza: un’analisi comparata = Copyright, contract and access to knowledge: a comparative analysis.
No full textIl processo di digitalizzazione e lo sviluppo dei media, stravolgendo il paradigma tradizionale del copyright/diritto d’autore conducono a reazioni opposte. Da un lato, estendendo in vario modo l’ampiezza dell’esclusiva autorale favoriscono l’adozione di regole restrittive di accesso e uso dei contenuti; dall’altro, alimentano le logiche di condivisione, specie in alcune aree di produzione del sapere.
Il contratto, pur mutata la propria natura nella dimensione digitale, rappresenta la prima leva per l’affermazione di tali divergenti dinamiche, che, in entrambe le direzioni, riguardano anche la circolazione della conoscenza scientifica. Nel senso dell’apertura, lo strumento negoziale consente di perseguire i principi affermati dal movimento dell’Open Access (OA), abbattendo le barriere economiche e giuridiche all’accesso e utilizzo dei contenuti.
Dal deposito e pubblicazione su archivi istituzionali e disciplinari di opere transitate già attraverso i canali editoriali convenzionali, comunemente definita green road, alla pubblicazione su riviste ad accesso aperto, gold road, il fenomeno si sviluppa dal basso verso l’alto grazie alle dichiarazioni di principio e alle norme informali che hanno sin ora guidato le comunità accademiche nell’affermazione dell’OA. Di recente, tuttavia, i principi dell’OA sono oggetto di attenzione da parte del decisore pubblico che, pur timidamente, ne “impone” l’attuazione a tutte le comunità accademiche. Eppure, il diritto formale non sembra da solo sufficiente: è soltanto il primo tassello di una disciplina organica tesa a definire regole e incentivi per la produzione e la disseminazione della conoscenza scientifica, allo scopo di bilanciare la libertà “accademica” con il diritto di accesso alla conoscenza. = ENGLISH VERSION = Along with a comparative perspective that takes account of the U.S. and Italian law, this work aims to explore the interface between copyright and contract lae in publishing process.
In the current publishing environment, contracts and technology play a dominant role in the exploitation of copyrighted works. Publishers are granted by assignment of all copyright rights to reproduce and publish the work, but also to exercise control over its contents through technological protection measures. At the same time, mass digitization allows libraries and other organizations to make contents available online, which it entails a redefinition of the traditional publishing process and introduces new players to the scene (e.g., Google Books).
Hence, technology proves to be a powerful instrument for the spread of knowledge and it is on this pattern that Open Access (OA) is rapidly gaining ground.
Mostly based on a bottom-up approach that is on soft law, institutional policies and contracts, OA designs a new legal environment targeting the objectives of free accessibility, further distribution, and proper archiving of publications. These aims can be achieved through the creation of new open access business models to publish on OA journals (gold road) or to self-archive in institutional or disciplinary repositories works that have been originally published in conventional journals (green road).
However, in order for OA to be fully developed it is necessary to devise a principled and feasible approach to the dissemination of scholarly works against the current social, economic and legal background.
Indeed, the importance of OA is steadily recognized by legislators who integrate OA provisions into their legal system. This is an innovation of great significance, which was first fostered in the USA, and then extended in some European countries such as Italy and Germany in the European framework. Nevertheless, considering the different law systems, the formal law need to be combined with national strategies and institutional policies providing adequate incentives to the authors, while also promoting academic freedom and the right to knowledge access
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