With the exponential growth of virtualization and cloud computing over the last decade, many companies in the telecommunications sector have started their journey towards cloud migration by exchanging a lot of specialized hardware for virtualized solutions. With more and more applications running in a cloud environment, it became essential to run these applications on heterogeneous systems with shared underlying hardware and software resources. However, running these applications in a heterogeneous cloud environment often leads to  unpredictable and non-deterministic performance, as all the applications compete for the shared resources to improve their individual performance. This becomes a problem when the interference from the co-hosted applications starts affecting the performance of the critical applications running on the same server. Ericsson is therefore investigating a solution to dynamically manage the low-level hardware and software resources to get deterministic performance on applications deployed using Kubernetes.  In this thesis, the Intent Driven Orchestration (IDO) model developed by Intel is used as the baseline model. This model was then extended by adding another tool to the setup called Container Runtime Interface-Resource Manager (CRI-RM), which is used to manipulate low-level software and hardware resources managed by a Kubernetes cluster at runtime. The results achieved in this thesis suggest that it is possible to get deterministic performance for an application deployed using Kubernetes, by identifying and isolating the CPU cores in the cluster on which the application is running.

The growth of distributed applications stand on a foundation of containers and their communication and have seen the rise and fall of many implementations throughout the years with a mix of proprietary and open sources. Today there are two implementations widely used as a result of the popularity of the huge project Kubernetes: CRI-O and Containerd. Both with the edge responsibility of managing containers using similar underlying software raising the question; do they have any implications on the containers they spawn? This thesis investigate these implementations from a performance perspective with a custom developed tool for direct communication to them and run a suite of benchmarks within the containers created by each. The suite consists of tests for throughput, latency, cpu, memory, random file read/write and sequential file read/write. Results conclude they perform similarly in all, but the file tests which showed overall CRI-O dominating in write speed and Containerd dominating the read speed.

Surface chemical gradients are materials that exhibit continuous, gradually varying chemical or physical properties along and across the length of a substrate. As a result, each point on the gradient surface can represent an individual sample. They are broadly classified as chemical and physical gradients depending upon the properties that the gradient exhibits. A physical gradient involves a continuous variation of physical properties such as surface roughness and film porosity on the micrometer scale. Chemical gradients involve a gradual variation of chemical properties such as polarity, acidity and basicity, etc. Such gradients have found various applications in cell adhesion, nanoparticle absorption, etc. Because of the multitude of potential applications of acid-base gradient materials in separation science and biological applications, the main work of this dissertation work is focused on the preparation and fundamental, molecular level investigation of acid-base gradients on siloxane surfaces. In this work, we focused on the preparation and characterization of surface charge gradients. Charged gradients are gradients that contain charged functional groups that are spatially distributed along the length of the substrate. They can interact with each other or with other species in solution by electrostatic interactions. They can also play a key role in governing the interaction of macromolecules and bacteria on surfaces, the wetting of surfaces, the layer-by-layer (LBL) assembly of thin films, reactions in catalysis, and the separation of charged species in chromatography. Therefore, understanding localized interactions between surface functional groups and charged species in solution are particularly relevant to the development of surfaces resistant to biofouling, antimicrobial surfaces, catalytic surfaces, multi-layered composite thin films, and imprinted surfaces for chemical sensing and separations. Thus, it is of great of interest to develop methodologies to create and study heterogeneous and homogeneous charged surfaces with well-defined properties. There have been several different methods developed for the preparation of charged gradients. First a chemical gradient is prepared and then the chemical gradient is converted to charged gradient by a chemical approach. Silane-based methods for the preparation of chemical gradients are among those that are widely used because of the straightforwardness of the chemistry involved and also the availability of silanes with various chemical functionalities. A few of these silane based approaches such as the vapor-diffusion method and liquid diffusion method have been used for various applications so far. Most of these methods are only able to prepare surface chemical gradients for a specific application mainly because of their limitations in terms of gradient-length scale and chemistry involved. In this work, we used a procedure already developed in our lab to prepare chemical gradients from different functionalized alkoxysilanes; we call this procedure the ‘controlled-rate infusion method (CRI)’. This method can be adapted to different substrates and can form gradients at various length-scales, such as few hundred microns to tens of centimeters. The CRI method involves the infusion of an organoalkoxysilane solution into a container with a substrate mounted vertically so that time-dependent exposure along the substrate forms a gradient in chemical functionality from bottom to the top. The most important attribute of this method is that the local steepness of the gradient can be systematically controlled by simply changing the rate of infusion. The steepness of the gradient can also be changed at predefined positions along its length by programming the rate of infusion. CRI can also be used to prepare gradients containing multiple functionalities, termed multicomponent chemical gradients. The different chemical functionalities can be oriented in different directions to produce gradients where functionalities can be oriented along the same or opposed directions producing aligned and opposed multicomponent chemical gradients, respectively. In this work, the multicomponent gradients were converted to charge gradients via chemical reaction with 30% H2O2. Using controlled rate infusion and this technique, aligned or opposed multicomponent charge gradients containing NH3+, SO3- and SiO- groups were prepared. By infusing 3-aminopropyltriethoxysilane (APTEOS) and 3-mercaptopropyltriethoxysilane (MPTMOS) in the same or opposed direction, gradients containing charged species in different locations relative to each other along the length of the substrate were made. The gradient properties in each case were different and correlated to the way they were prepared i.e., where the gradients were oriented in an aligned or opposed fashion. Surface wettability and local surface charge, etc were found to be entirely different depending on the type of charge gradients (aligned and opposed). In another example, SiO- and NH3+ opposed gradients were prepared by infusing APTEOS on different base layers prepared from tetramethoxysilane (TMOS), phenyltrimethoxysilane (PTMOS), dimethyldimethoxysilane (DMDMOS) or octyltrimethoxysilane (OTMOS) followed by protonation of the surface amines. The gradient profiles and surface wettability were found to be independent of each other and dependent of the type of the base layer. In summary, this dissertation work focuses mainly on the preparation of multicomponent charge gradients and their molecular level characterization by a multitude of different analytical methods including XPS spectroscopy, tapping mode atomic force microscopy (TM-AFM), zeta potential measurement, and SCA and DCA measurements. CRI has incredible flexibility and adaptability, which was confirmed by extending it to different siloxane base films and creating gradients with different functionalities. Multicomponent charge gradients containing acid and base functionalities can be prepared and optimized for and acid base catalysis reactions such Michael addition as well as aldol, Henry, and Knoevenagel condensations.

Les effets cardiovasculaires des alpha-2 agonistes, particulièrement importants chez les chiens, limitent leur utilisation en pratique vétérinaire. La perfusion à débit constant (PDC) de ces drogues, comme la médétomidine (MED) permettrait un contrôle plus précis de ces effets. Les effets hémodynamiques de plusieurs doses de MED en PDC ont été évalués chez le chien. Lors de cette étude prospective, réalisée en double aveugle, 24 chiens en santé, ont reçu de façon aléatoire une des 6 doses de MED PDC (4 chiens par groupe). Les chiens ont été ventilés mécaniquement pendant une anesthésie minimale standardisée avec de l’isoflurane dans de l’oxygène. Une dose de charge (DC) de médétomidine a été administrée aux doses de 0.2, 0.5, 1.0, 1.7, 4.0 ou 12.0 µg/kg pendant 10 minutes, après laquelle la MED PDC a été injectée à une dose identique à celle de la DC pendant 60 minutes. L’isoflurane a été administré seul pendant une heure après l’administration d’une combinaison d’ISO et de MED PDC pendant 70 minutes. La fréquence cardiaque (FC), la pression artérielle moyenne (PAM) et l’index du débit cardiaque (IC) ont été mesurés. Des prélèvements sanguins ont permis d’évaluer le profil pharmacocinétique. D’après ces études, les effets hémodynamiques de la MED PDC pendant une anesthésie à l’isoflurane ont été doses-dépendants. L’IC a diminué progressivement alors que la dose de MED augmentait avec: 14.9 (12.7), 21.7 (17.9), 27.1 (13.2), 44.2 (9.7), 47.9 (8.1), and 61.2 (14.1) % respectivement. Les quatre doses les plus basses n’ont provoqué que des changements minimes et transitoires de la FC, de la PAM et de l’IC. La pharmacocinétique apparaît clairement dose-dépendante. De nouvelles expériences seront nécessaires afin d’étudier l’utilisation clinique de la MED PDC. / The cardiovascular effects of alpha-2 agonists, particularly pronounced in dogs, limit their use in veterinary practice. The use of these drugs, namely medetomidine (MED), by constant rate infusion (CRI), could allow more precise control of the cardiovascular effects. The haemodynamic responses of MED CRI at several dosages in dogs were investigated. In a prospective, blinded study, 24 healthy beagles randomly received one of 6 MED CRI regimens (4 dogs per regimen). Dogs were mechanically ventilated to maintain stable low-level isoflurane (ISO) anaesthesia in oxygen. A loading MED infusion was administered at 0.2, 0.5, 1.0, 1.7, 4.0 or 12.0 µg•kg-1 for 10 min, followed by maintenance CRI for 60 min providing identical dose amounts for all dogs (total duration for MED and ISO: 70 min). Isoflurane was then administered alone for an additional hour. Heart rate (HR), mean arterial blood pressure (MAP), and cardiac index (CI) were recorded. Blood sampling was performed to establish pharmacokinetic profiles. Based on this study, the hemodynamic effects of MED CRI during ISO anaesthesia were found to be dose-dependent. Baseline CI decreased dose-dependently as MED dose increased by: 14.9 (12.7), 21.7 (17.9), 27.1 (13.2), 44.2 (9.7), 47.9 (8.1), and 61.2 (14.1) % respectively. The four lowest dosages created limited and transient changes in HR, MAP, and CI. Pharmacokinetics were dose-dependent. Further investigations for perioperative use are warranted.

Made available in DSpace on 2016-04-25T18:39:51Z (GMT). No. of bitstreams: 1 Mauricio Godoi Amaral Lima.pdf: 917720 bytes, checksum: 0806aea0afa76bf8a6856581ecf44982 (MD5) Previous issue date: 2012-10-08 / The Brazilian real estate market has been growing at high rates which makes us the question if the tools that have been currently used in SFH will be enough to meet the increasing demand for financings, taking into account that this form has the saving account as its main source of resources. To fulfill the need of alternative sources of housing finance, the SFI was created, that allowed another way of catchment, the real state receivables securitization, making a secondary market of real estate assets. A historical study has been done showing the main inefficiencies in housing financing system, from 1964 to 1997, with the creation of SFI. Going through all the legal scope developed for the implementation of this new system, trying to understand the main reason why securitization is not a tool in Brazil, compared to the high potential we have after macroeconomical stability. A historical data raising is made, applying the method to the bibliography and quantitative research to verify the maintenance of the current financial resources catchment way for real state credit, comparing the saving account resources directing, demand quantity by financing, and the ways that new catchment tools, such as securitization, can contribute for supporting the real estate credit in the future / O mercado imobiliário brasileiro vem crescendo em elevados índices o que faz refletir se as ferramentas que são atualmente praticadas no SFH serão suficientes para atender a crescente demanda por financiamentos, tendo em vista que essa forma, tem a caderneta de poupança como principal fonte de recursos. Para suprir essas necessidades de fontes alternativas para os financiamentos habitacionais, foi criado o SFI, que permitiu a captação sob outra forma, a securitização de recebíveis imobiliária, constituindo o mercado secundário de ativos imobiliários. É realizado um estudo histórico, mostrando as principais ineficiências no Sistema Financeiro da Habitação, com início em 1964 e chegando até 1997, com a criação do SFI. Passando por todo arcabouço jurídico desenvolvido para implantação desse novo sistema, buscando entender o principal motivo que a securitização não é uma ferramenta trabalhada no Brasil, comparada com o grande potencial que temos após a estabilidade macroeconômica. Efetua-se um levantamento de dados históricos, aplicando o método de pesquisa bibliográfica e quantitativa para verificar a manutenção da forma atual de captação de recursos financeiros destinados ao crédito imobiliário, comparando o direcionamento compulsório dos recursos de poupança, quantidade da demanda por financiamentos e as formas que as novas ferramentas de captação, como securitização, contribuirá para a sustentação do crédito imobiliário no futuro

Made available in DSpace on 2016-04-25T18:39:54Z (GMT). No. of bitstreams: 1 Claudio Goncalves dos Santos.pdf: 1107656 bytes, checksum: eabf420541f3dc3be47a28e1581159b5 (MD5) Previous issue date: 2013-06-27 / The market for financial disintermediation, through financial asset securitization in Brazil has been growing in recent years. Constant improvements in regulation, has contributed to closer business investors in a regulated environment, making it possible to carry out financial transactions outside the traditional banking financial market. There is much yet to be done by regulators to strengthen the market. This work seeks to contribute to the theme, suggesting some changes in the regulations. From 2000 to 2012, the securitization transactions through structures with CRI, FIDC, and FII moved R$ 149.8 billion, equivalent to 3.4% of the GDP in 2012. Operations tend to increase, however, there are some variables in the Brazilian market, which will be analyzed in this work, that need to be adjusted so that the securitization market is nimble robustly contributing to the financing of companies. In this paper we analyze the main sources of funding for companies, as equity and the various sources of debt, and securitization. Will also analyzed the market for corporate debt, without which the operations are limited to the traditional banking system. The development of the debt Market strengthens the growth of the securitization market / O mercado de desintermediação financeira, por meio de instrumentos de securitização de ativos, vem crescendo no Brasil nos últimos anos. Melhorias constantes na regulamentação têm contribuído para aproximar empresas de investidores, em ambiente regulado, tornando possível a realização de operações financeiras fora do mercado financeiro bancário tradicional. Mas ainda existe muito a ser feito pelos reguladores para fortalecer o mercado. Nesse sentido, este trabalho procura contribuir com o tema, sugerindo algumas mudanças na regulamentação. De 2000 a 2012, as operações de securitização por meio de estruturas como CRI, FIDC e FII, movimentaram R$ 149,8 bilhões, o equivalente a 3,4% do PIB brasileiro de 2012. As operações tendem a aumentar, porém existem algumas variáveis no mercado brasileiro, as quais serão analisadas ao longo deste trabalho, que precisam ser ajustadas, para que o mercado de securitização se desenvolva de forma robusta, contribuindo para o financiamento das empresas. Nesta dissertação, serão analisadas as principais fontes de recursos para empresas, como capital próprio e as diversas fontes de capital de terceiros, além da securitização. Será analisado, também, o mercado de dívida para empresas, sem o qual as operações ficam limitadas ao sistema bancário tradicional. O desenvolvimento do mercado de dívida fortalece o crescimento do mercado de securitização

La théorie de la sélection sexuelle a drastiquement orienté l’effort de recherche sur la communication acoustique chez les oiseaux : les mâles apprennent et produisent des chants élaborés et les femelles choisissent. Par conséquent (1) la production vocale chez les femelles a été négligée, (2) les cris (la majorité de la communication sociale) ont été peu étudiés. Contrairement aux chants, les cris ont été considérés comme innés et aucun effet de l’environnement sur leur structure n’était attendu. J’ai donc posé la question de la flexibilité vocale (court-terme) et de la plasticité vocale (au cours du développement) chez les femelles, en étudiant les cris majoritairement. J’ai étudié deux contextes où les deux sexes vocalisent: la communication dans le couple au nid et la communication parent-jeunes. Les vocalisations produites au nid par les couples montrent-elles de la flexibilité en réponse au bruit? Le développement des cris est-il influencé par l’environnement social ? J’ai travaillé sur deux espèces: le cincle plongeur, Cinclus cinclus et le diamant mandarin, Taeniopygia guttata. Chez les deux espèces, en réponse au bruit, les couples augmentent l’amplitude de leurs vocalisations. Chez le cincle une variation de la structure spectrale est observée dans les notes de chant mais pas dans les cris. Chez le diamant mandarin, les cris montrent des changements de leur structure spectrale: ils peuvent donc être flexibles en réponse au bruit. Les changements sont similaires chez les femelles et les mâles : la flexibilité n’est pas spécifique du sexe. Enfin, j’ai montré que l’environnement social précoce influence le développement des cris de quémande alimentaire chez le diamant mandarin : il existe une plasticité précoce des cris chez les mâles. J’ai montré que les femelles expriment des degrés de flexibilité similaires aux mâles mais que leur développement vocal peut prendre des trajectoires différentes. Les cris sont de bons objets de recherche pour étudier des variations de comportement vocal liées au sexe / The theory of sexual selection has drastically oriented research on acoustic communication in birds: males learn and sing conspicuous songs and females choose. Consequently, (1) female vocal production has been neglected, (2) birdcalls (most bird social communication) have been understudied. Birdcalls were supposed to be non-learned and no effect of the environment was expected on their structure (no flexibility, no learning). I thus focused my thesis on vocal flexibility (short-term) and vocal plasticity (developmental) of female vocalizations (mainly calls). I studied two contexts in which both sexes produce vocalizations: intrapair communication at the nest and parent-offspring communication. Do pairs express vocal flexibility in their calls in response to environmental noise? Is call development influenced by social environment? I studied two species: the white-throated dippers, Cinclus cinclus. (in which both sexes produce calls and songs) and the zebra finch, Taeniopygia guttata, (in which only males sing but both sexes use the same calls). I showed in both species, that in response to environmental noise, pairs increased the amplitude of their calls or song notes. In dippers, spectral flexibility was observed in song notes but not in calls. However, zebra finch calls showed spectral flexibility in response to noise. Both sexes showed similar changes in their calls: call spectral flexibility is not sex specific. Last, I showed that the structure of male begging calls changed in response to the early social environment, bringing evidence of early vocal plasticity in males. No change was found in females, showing that they either differ in their plasticity abilities or do not express plasticity because they receive different social feedbacks. My work showed that females and males show vocal flexibility but their vocal developmental trajectories may differ. Calls are thus good study objects to investigate sexual dimorphism in vocal behaviour

Cette étude s'intéresse à la remise en question de la conception traditionnelle de la citoyenneté canadienne par les revendications d'autodétermination des peuples autochtones. Nous nous penchons plus particulièrement sur le cas des Cris de la Baie James et des Inuit du Nunavik depuis la signature de la Convention de la Baie James et du Nord Québécois, en 1975. Nous postulons que ces deux peuples ont développé des régimes de citoyenneté distincts au sein de leur communauté politique régionale respective. Ces régimes de citoyenneté, qui évoluent tous deux à l'intérieur du cadre de la fédération canadienne, imposent des pressions différentes à la conception traditionnelle de la citoyenneté canadienne. Nous voyons quatre grands courants de pensée se dessiner dans la littérature à propos des façons d'accommoder les revendications des autochtones. Premièrement, le courant intégrationniste, qui a comme objectif l'assimilation des autochtones aux institutions de la majorité. Deuxièmement, le courant différentialiste, qui se dissocie des thèses assimilationnistes et qui croit en limportance d'accorder plus d'autonomie gouvernementale aux autochtones, mais qui demeure principalement préoccupé par l'unité du sujet politique canadien. Troisièmement, le courant multinational, qui propose une refonte de l'association entre les nations permettant à chaque peuple de trouver la place qui lui convient au sein de l'ensemble fédéral. Quatrièmement, le courant dualiste, qui aimerait voir l'instauration de systèmes politiques parallèles pour les autochtones, qui se sentent étrangers aux institutions politiques de la majorité. Selon nous, les Cris ont développé une forme de citoyenneté qui s'apparente au courant multinational, tandis que les Inuit ont développé une citoyenneté s'inscrivant dans le courant différentialiste. Nous postulons que ces différences dans les formes de citoyenneté développées par les Cris et les Inuit sont dues aux différences dans leur réalité démographique et dans leur histoire avec les gouvernements canadien et québécois. Afin d'analyser l'émergence et l'évolution de ces régimes de citoyenneté distincts, nous utilisons les trois dimensions de la citoyenneté de Joseph Carens -les dimensions légale, politique et psychologique. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Citoyenneté, Régime de citoyenneté, Autochtones, Cris de la Baie James, Inuit du Nunavik, Autonomie gouvernementale, Nationalisme, Multinationalisme.

Ce mémoire fait la démonstration de l'importance de la thématique territoriale en littérature autochtone. Ce thème participe, chez les auteurs amérindiens, d'un discours valorisant les appartenances territoriales dans la construction des identités individuelles et collectives. La théorie postcoloniale s'avère pertinente pour l'étude de la littérature autochtone, en autant que son contexte de production particulier soit pris en compte. Les réflexions d'Edward W. Said sur l'imaginaire du colonialisme présentent deux concepts importants de la thématique territoriale : la violence géographique et la réinscription. Tout mouvement de décolonisation devant inclure la restauration de l'identité géographique, qui peut s'effectuer de manière symbolique par la littérature, la réinscription permet en quelque sorte de remédier à la violence géographique. La saga des Béothuks propose une réflexion sur l'unité du passé historique et la transmission de la mémoire. La survie des Béothuks repose sur leur capacité à interpréter le paysage et ses repères, dont la présence est tributaire du fragile équilibre entre l'être humain, la terre et le sacré. La représentation littéraire des lieux reflète cet équilibre, puisque la disparition des passages descriptifs coïncide avec la dépossession territoriale des Béothuks. La rupture des liens entre les êtres humains et la terre mène à l'atomisation de la nation béothuke, transformant la volonté de survie collective en volonté de survie individuelle, processus également reflété par l'évolution du mode narratif : le rétrécissement du territoire se traduit par un point de vue narratif de plus en plus étroit. L'entreprise de Bernard Assiniwi consiste donc à occuper un territoire imaginaire laissé vacant et à réinvestir un récit historique jugé incomplet. La réinscription des Béothuks sur l'île de Terre-Neuve crée une faille dans l'imaginaire géographique du colonialisme. Pour sa part, Ourse bleue préconise une perspective crie du territoire de la baie James, en opposition au discours québécois qui se l'est approprié par un mythe de conquête. Les thèmes de la mémoire et du territoire reflètent les réalités cries, tout comme les transformations du territoire et des paysages de l'enfance de la narratrice, paysages porteurs de sens qui exigent une sensibilité accrue aux lieux. L'analyse des métaphores spatiales permet de confirmer l'influence, sur le récit, de l'évolution du rapport au territoire de Victoria. Par sa redécouverte de repères géographiques, culturels et familiaux, la narratrice se réinscrit dans l'univers culturel et le territoire cris. Ourse bleue pose donc les jalons d'un nouveau récit de la baie James, à la fois personnel et collectif. Le discours sur le territoire se complexifie : tandis que le territoire était avant tout une donnée collective propre à la nation dans la Saga, il se double dans Ourse bleue d'une approche individuelle et spirituelle. Les personnages effectuent des parcours inverses : les Béothuks vivent la dépossession et n'arrivent plus à faire corps avec leur terre, alors que Victoria redécouvre le territoire de sa famille et son identité crie. En somme, la Saga met en scène le rétrécissement de l'univers béothuk tandis qu'Ourse bleue participe de l'ouverture des espaces autochtones, mais ils constituent tous les deux une variation sur les thèmes de la mémoire et du territoire, en évoquant deux conditions cruciales de la survie des cultures autochtones : la transmission de la mémoire collective et la possibilité d'ancrer son identité dans un rapport toujours renouvelé avec le territoire. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : littérature autochtone du Québec, Bernard Assiniwi, Virginia Pésémapéo Bordeleau, territoire autochtone, études postcoloniales, Béothuks, Cris, Terre-Neuve, baie James.

Les effets cardiovasculaires des alpha-2 agonistes, particulièrement importants chez les chiens, limitent leur utilisation en pratique vétérinaire. La perfusion à débit constant (PDC) de ces drogues, comme la médétomidine (MED) permettrait un contrôle plus précis de ces effets. Les effets hémodynamiques de plusieurs doses de MED en PDC ont été évalués chez le chien. Lors de cette étude prospective, réalisée en double aveugle, 24 chiens en santé, ont reçu de façon aléatoire une des 6 doses de MED PDC (4 chiens par groupe). Les chiens ont été ventilés mécaniquement pendant une anesthésie minimale standardisée avec de l’isoflurane dans de l’oxygène. Une dose de charge (DC) de médétomidine a été administrée aux doses de 0.2, 0.5, 1.0, 1.7, 4.0 ou 12.0 µg/kg pendant 10 minutes, après laquelle la MED PDC a été injectée à une dose identique à celle de la DC pendant 60 minutes. L’isoflurane a été administré seul pendant une heure après l’administration d’une combinaison d’ISO et de MED PDC pendant 70 minutes. La fréquence cardiaque (FC), la pression artérielle moyenne (PAM) et l’index du débit cardiaque (IC) ont été mesurés. Des prélèvements sanguins ont permis d’évaluer le profil pharmacocinétique. D’après ces études, les effets hémodynamiques de la MED PDC pendant une anesthésie à l’isoflurane ont été doses-dépendants. L’IC a diminué progressivement alors que la dose de MED augmentait avec: 14.9 (12.7), 21.7 (17.9), 27.1 (13.2), 44.2 (9.7), 47.9 (8.1), and 61.2 (14.1) % respectivement. Les quatre doses les plus basses n’ont provoqué que des changements minimes et transitoires de la FC, de la PAM et de l’IC. La pharmacocinétique apparaît clairement dose-dépendante. De nouvelles expériences seront nécessaires afin d’étudier l’utilisation clinique de la MED PDC. / The cardiovascular effects of alpha-2 agonists, particularly pronounced in dogs, limit their use in veterinary practice. The use of these drugs, namely medetomidine (MED), by constant rate infusion (CRI), could allow more precise control of the cardiovascular effects. The haemodynamic responses of MED CRI at several dosages in dogs were investigated. In a prospective, blinded study, 24 healthy beagles randomly received one of 6 MED CRI regimens (4 dogs per regimen). Dogs were mechanically ventilated to maintain stable low-level isoflurane (ISO) anaesthesia in oxygen. A loading MED infusion was administered at 0.2, 0.5, 1.0, 1.7, 4.0 or 12.0 µg•kg-1 for 10 min, followed by maintenance CRI for 60 min providing identical dose amounts for all dogs (total duration for MED and ISO: 70 min). Isoflurane was then administered alone for an additional hour. Heart rate (HR), mean arterial blood pressure (MAP), and cardiac index (CI) were recorded. Blood sampling was performed to establish pharmacokinetic profiles. Based on this study, the hemodynamic effects of MED CRI during ISO anaesthesia were found to be dose-dependent. Baseline CI decreased dose-dependently as MED dose increased by: 14.9 (12.7), 21.7 (17.9), 27.1 (13.2), 44.2 (9.7), 47.9 (8.1), and 61.2 (14.1) % respectively. The four lowest dosages created limited and transient changes in HR, MAP, and CI. Pharmacokinetics were dose-dependent. Further investigations for perioperative use are warranted.