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Ce mémoire présente une analyse des capacités d'un réseau de neurones à décharges à quatre couches comportant des neurones complexes, dont le champ récepteur est défini par des entrées synchrones, dans le contexte d'une application de reconnaissance de formes. Avec le développement d'un modèle informatique basé sur les études neurophysiologiques, un procédé de projection de l'information vers les neurones complexes est présenté. De plus, une corrélation temporelle est utilisée pour établir la reconnaissance de formes. Une première étape permet de segmenter des images sources à l'aide d'une communication synaptique intra-couche. Puis, une projection sur deux nouvelles couches de neurones complexes et une communication synaptique extra-couche permettent de comparer des formes semblables. S'il y a correspondance entre deux ou plusieurs régions, une synchronisation des neurones complexes est décelée, sinon, il n'y aura pas de synchronisation des neurones. L'objectif est d'employer, dans un premier temps, cette nouvelle structure de réseau de neurones à décharges pour la reconnaissance de formes ayant divers niveaux de complexité, et, dans un deuxième temps, de comprendre les apports des choix de conception sur le comportement du réseau. Les expérimentations posées ont permis de conclure que le réseau développé, SyncOsc, est globalement plus performant que le réseau de comparaison ODLM. SyncOsc se montre en effet plus stable, bien plus rapide et apte à traiter des images de grandes tailles, ce que ODLM ne peut réaliser.

Inflammatory pain is a debilitating condition that can occur following tissue injury or inflammation and results in touch evoked pain (allodynia), exaggerated pain (hyperalgesia) and spontaneous pain, yet the neural plasticity underlying these symptoms is not fully understood. However, it is known that lamina I neurokinin 1 receptor expressing (NK1R+) spinal cord output neurons are crucial for the manifestation of inflammatory pain. There is also evidence that the afferent input to and the postsynaptic response of these neurons may be altered in inflammatory pain, which could be relevant for inflammatory pain hypersensitivity. Therefore, the aim of this thesis was to study inflammatory pain spinal plasticity mechanisms by investigating the synaptic input to lamina I NK1R+ neurons. In ex vivo spinal cord and dorsal root preparations from the rat, electrophysiological techniques were used to assess inflammation-induced changes in and pharmacological manipulation of the primary afferent drive to lamina I NK1R+ neurons. The excitatory input to lamina I NK1R+ neurons was examined and it was found that inflammation did not alter the relative distribution of the type of primary afferent input received and did not potentiate monosynaptic A δ or monosynaptic C-fibre input, the predominant input to these neurons. Spontaneous excitatory input was significantly elevated in the subset of neurons that received monosynaptic A δ-fibre input only, regardless of inflammation. It has recently been shown that the chemerin receptor 23 (ChemR23) represents a novel inflammatory pain target, whereby ChemR23 agonists can decrease inflammatory pain hypersensitivity, by a mechanism that involves the attenuation of potentiated spinal cord responses. This study has found that the ChemR23 agonist, chemerin, attenuated capsaicin potentiation of excitatory input to lamina I NK1R+ neurons and significantly reduced monosynaptic C-fibre input to a subset of these neurons in inflammatory pain. However, chemerin was without effect in non-potentiated conditions. In exploring potential inflammatory pain spinal plasticity mechanisms, I have investigated a phenomenon called activity-dependent slowing (ADS), whereby repetitive stimulation of C-fibres at frequencies of 1Hz or above results in a progressive slowing of action potential conduction velocity, which manifests as a progressive increase in response latency. This is proposed to limit nociceptive input to the spinal cord, thus regulating plasticity. Results demonstrate that inflammation significantly attenuated C-fibre ADS in isolated dorsal roots. Furthermore, ADS in monosynaptic C-fibre input to lamina I NK1R+ neurons was significantly reduced in inflammatory pain, which could facilitate nociceptive drive to these key spinal cord output neurons and promote inflammatory pain spinal cord plasticity. In conclusion, the major novel findings of this thesis are firstly, that chemerin can attenuate primary afferent input to lamina I NK1R+ neurons in potentiated conditions, which supports recent studies that suggest ChemR23 is a potential target for the development of new analgesics. Secondly, it was discovered that ADS in monosynaptic C-fibre inputs to lamina I NK1R+ neurons is altered in inflammatory pain, which could be relevant for inflammatory pain spinal plasticity. The findings presented in this thesis could contribute to the development of novel inflammatory pain treatments.

縮基法(RBM) 是對參數化的曲線求逼近解的一個方法，基本上乃使用投影法將解曲線投射到解空間的一子空間中，如此一來，可將原問題轉換成一較小的系統，並經由數值計算出小系統的解，來求得大系統的一逼近解。在本篇論文中主要的乃探討RBM在常微分方程組初始值問題上的應用，並發展一套含有誤差控制的演算法。 本篇論文中所採用的ODE Solver 乃由Gordon 和Shampine 基於Adams PECE方法所發展的。在求解的過程中，對於計算解誤差的控制我們除了利用ODE Solver 的誤差估計，另外我們又發展對縮基解(reduced basis solution) 的後(Aposteriori) 誤差估計，以確保數值計算解的準確性。我們所考慮使用的子空間有三種Taylor, Lagrange , Hermite 。同時為了要增加數值的特定性及簡化小系統的求解工作，我們先行將子空間的基底直交化。因此，除了誤差的控制外，我們也討論了roundoff error 對向量直交化及形成小系統時所造成的影響，並設立誤差標準以判別何時誤差過大到嚴重影響縮基解的準確度。 本篇論文的目的是希望利用RBM發展出一套解常微分方程組初始值問題的求算法，以期計算解能在較短的時間內準確的被計算出來。 / The reduced basis method(RBM) is a scheme for approximating parametric solution curves. The basic technique of RBM is projection. By applying the method, we can find an approximate solution of the original system which satisfies a system of smaller size. In this paper, we mainly concern the applications of RBM for ODE initial value problems and develop an algorithm which contains a set of error controls. The ODE solver used in this paper is developed by Gordon and Shampine based on Adams PECE formulas. To assure the accuracy of the reduced basis approximation, we set up an appropriate automatic error control in calling GS solver and develop an a posteriori error estimate to keep the reduction error under control. The subspaces considered are Taylor, Lagrange and Hermite subspaces.In the meantime, in order to improve the numerical stability and simplify the computation of the reduced basis solution, we orthogonalize the generators of reduced subspaces. We also discuss the roundoff errors in the orthogonalization process and build up a criterion for identifying the case the accuracy of the reduced basis solution up a criterion for identifying the case the accuracy of the reduced basis solution is destroyed by the errors. The aim of this paper is to develop an algorithm to solve the ODE initial value problems efficiently.

Neointimal hyperplasia, the proliferative growth of the innermost layer of the blood vessel wall, is a key process in the response to vascular injury, underlying conditions such as post-interventional restenosis and vein/arterial graft disease. One of the many mediators implicated in this process is endothelin-1 (ET-1), a potent vasoconstrictor with pro-inflammatory and pro-mitogenic actions, which acts through ETA and ETB receptor subtypes. It is well established that ET-1 increases, and ETA blockade reduces, neointima formation following vascular injury. The role of ETB is less clear because these receptors mediate potentially beneficial actions in endothelial cells (EC; such as nitric oxide production, and ET-1 clearance) but detrimental effects elsewhere (such as vascular smooth muscle) and it has been recently reported that non-cell-specific ETB deficiency is associated with increased neointimal lesion size following injury. The work described in this thesis addressed the hypothesis that endogenous ET-1 contributes to neointimal hyperplasia by activation of the ETA receptor, and that this action is moderated by concurrent activation of the ETB receptor expressed in EC. The role of ET receptors in neointimal lesion development was assessed using two models of femoral arterial injury in the mouse: (i) an established method of intraluminal wire-injury, and (ii) adaptation of a model of ligation injury that induces robust neointimal lesion formation without physical damage to the endothelium. Lesion development was assessed using standard histological techniques and this was augmented by development of quantitative optical projection tomography (OPT) to allow three-dimensional analysis of lesions. The role of ETA and ETB receptors in these models was addressed using suitable pharmacological ET receptor antagonists. Following wire-injury, selective ETB blockade (A192621; 30mg.kg-1.day-1; 35 days) increased lesion size and blood pressure without significant altering lesion composition. In contrast, selective ETA blockade (atrasentan; 10mg.kg-1.day-1; 35 days) reduced lesion size and blood pressure. Combined ETA+ETB antagonism had no effect on lesion size, despite reducing blood pressure, and reducing collagen content of the lesions. In the ligation model, neither ETA selective, ETB selective nor ETA+ETB blockade altered lesion size as assessed by standard histology but analysis by OPT indicated that ETA blockade, with or without concurrent ETB blockade, reduced lesion volume. The influence of ETB receptors expressed by ECs on lesion formation was addressed using EC-specific ETB knockout mice. Small vessel myography indicated that endothelium-dependent relaxation was unaltered in femoral arteries from these mice. In addition, no effect on lesion size or rate of development was observed in either wire- or ligation-injury models of neointima formation (although subtle effects on lesion and medial composition were apparent after intra-luminal injury). These results indicate that ETB receptor activation can moderate the detrimental actions of the ETA receptor on neointimal lesion progression, and that this role is dependent on the mode of vascular injury. Furthermore, in this setting, this beneficial action is not primarily mediated by ETB expressed by EC, suggesting that ETB in other cell types can reduce lesion development through another, unidentified mechanism. Therefore, while both ETA selective and non-selective ETA/B antagonists are currently in clinical use, in conditions where similar arterial remodelling processes occur, selective ETA receptor antagonists might be preferred.

Two types of problems are studied in this thesis: reconstruction and visualization of polygons and polyhedra. <br /><br /> Three problems are considered in reconstruction of polygons and polyhedra, given a set of projection characteristics. The first problem is to reconstruct a closed convex polygon (polyhedron) given the number of visible edges (faces) from each of a set of directions <em>S</em>. The main results for this problem include the necessary and sufficient conditions for the existence of a polygon that realizes the projections. This characterization gives an algorithm to construct a feasible polygon when it exists. The other main result is an algorithm to find the maximum and minimum size of a feasible polygon for the given set <em>S</em>. Some special cases for non-convex polygons and for perspective projections are also studied. <br /><br /> For reconstruction of polyhedra, it is shown that when the projection directions are co-planar, a feasible polyhedron (i. e. a polyhedron satisfying the projection properties) can be constructed from a feasible polygon and vice versa. When the directions are covered by two planes, if the number of visible faces from each of the directions is at least four, then an algorithm is presented to decide the existence of a feasible polyhedron and to construct one, when it exists. When the directions see arbitrary number of faces, the same algorithm works, except for a particular sub-case. <br /><br /> A polyhedron is, in general, called equiprojective, if from any direction the size of the projection or the projection boundary is fixed, where the "size" means the number of vertices, edge, or faces. A special problem on reconstruction of polyhedra is to find all equiprojective polyhedra. For the case when the size is the number of vertices in the projection boundary, main results include the characterization of all equiprojective polyhedra and an algorithm to recognize them, and finding the minimum equiprojective polyhedra. Other measures of equiprojectivity are also studied. <br /><br /> Finally, the problem of efficient visualization of polyhedra under given constraints is considered. A user might wish to find a projection that highlights certain properties of a polyhedron. In particular, the problem considered is given a set of vertices, edges, and/or faces of a convex polyhedron, how to determine all projections of the polyhedron such that the elements of the given set are on the projection boundary. The results include efficient algorithms for both perspective and orthogonal projections, and improved adaptive algorithm when only edges are given and they form disjoint paths. A related problem of finding all projections where the given edges, faces, and/or vertices are not on the projection boundary is also studied.

There is an abundance of reports and articles on the extent of future bioenergy usage. Decision-makers might turn to bioenergy projections in hopes of making informed decisions for policies or investments. This report aims to highlight irregularities and differences regarding calculations and results in 15 global bioenergy projection studies for the year 2050, and to find underlying connections by applying a metaanalysis with a methodological focus. Statistical distributions were made for the projected global bioenergy potentials. A growth rate study based on the projected global bioenergy potentials was made and used as a simple “reality check”. Regarding Sweden and the EU, it was investigated whether decisions has been made based on estimated bioenergy potentials. The final aim was to make recommendations for bioenergy decision-makers and policy-makers. There are many statistical distributions fitting the projections for 2050. The distribution functions showed that with a 95 % confidence level, the bioenergy projections in 2050 is 151.3 EJ. The interquartile range of all studies included in this report for primary bioenergy in the year 2050 was shown to be 120-400 EJ, with minimum value of 30 EJ and maximum of 1600 EJ. A mere third of the projection values were in the vicinity of a linear or exponential trendline based on historical values. The historical annual average growth rate for bioenergy from 1971 to 2011 was found to be 1.9 percent. A higher growth rate is required to achieve the larger quantities that are projected in most studies, the most extreme rate was 7.6 percent, which is far above the average. The EU has adopted a biomass action plan partly based on bioenergy projections by the European Energy Agency in 2006. National and international energy projection reports influence Swedish politics, albeit not directly in propositions. The difference between individual reports and articles projected bioenergy level in 2050 is significant. It is recommended to read more than one. Most forecasting models and estimates will likely perform poorly numerically, so it is recommended to look for underlying factors, connected longterm trends, or behavioral consequences.

Night of Glass is for chamber orchestra with an estimated performance time of 14 minutes. The instrumentation for the work, using one player per part, is Flute (also small glass wind chimes), Oboe (also 1 tuned water crystal), Clarinet in A (also small glass wind chimes), Bassoon (also 1 tuned water crystal), Horn in F (also 1 tuned water crystal), Trumpet in C (also 2 tuned water crystals), Percussion (Vibraphone, Glockenspiel, Chimes, Bell Tree, Hammered Dulcimer, 3 Suspended Cymbals, 1 Large Tam-tam, 4 Roto Toms, 3 Tympani), Piano, 1st Violin, 2nd Violin, Viola, Cello, and Double Bass, While not programmatic, the work is divided into six sections each expressing a predetermined emotional content: fragility, anxiety, solitude, fear, catharsis, and reconciliation. All are emotional contents which are found in the dream-state that is reflected in the work's title. All aspects of Night of Glass (i.e., pitch material, form structure, and structural density) are centered around the unifying factor of emotional projection within each section. The work seeks emotional content through the expansion of composition procedures while being accessible to listeners.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

La projection par plasma de suspension d’hydroxyapatite, d’oxyde de titane et de zircone yttriée permettant d’obtenir des revêtements biocompatibles, des barrières thermiques ou encore des surfaces photo-catalytiques est étudiée. Les revêtements sont projetés à l’aide d’une torche plasma SG-100. La puissance électrique se situe entre 27 et 40 kW et les distances de projection entre 40 et 70 mm, selon le type de matériau projeté. La stabilité de la suspension est déterminée par des mesures de potentiels Zeta. Les propriétés mécaniques des revêtements d’hydroxyapatite après projection et après immersion dans un fluide physiologique sont comparées. Il en résulte que la dureté augmente avec la durée d’immersion. Pour les revêtements de titane, l’essai de rayure a confirmé la bonne adhérence et la bonne cohésion de ce type de revêtement. Nous avons également observé que les revêtements testés montrent de meilleures propriétés photo-catalytiques que les revêtements commerciaux Pilkington Active™ glass. L’étude des revêtements à base d’oxydes de zircone s’est focalisée sur les propriétés mécaniques et le transport thermique. L’indentation instrumentée confirme les très bonnes propriétés mécaniques de ces revêtements, jusque 3.5 GPa pour la dureté et jusque 130 GPa pour le module d’élasticité. Nous avons aussi observé que les valeurs de conductivité thermique des revêtements testés sont plus faibles que celles des revêtements projetés avec des méthodes conventionnelles.En conclusion, les revêtements obtenus par projection plasma présentent des propriétés qui les rendent utilisables dans de nombreuses applications. / The basics of thermal spraying were presented. Suspension plasma spraying method was described and also possible applications, as biocompatible coatings, thermal barrier or photo-catalytic surfaces were presented. Instrumented indentation test was characterized. In work hydroxyapatite, titanium dioxide, yttria stabilized zirconia and yttria with ceria stabilized zirconia were used. Set-up of plasma spray installation was presented. The stability of suspension was determined by zeta potential measurements. Coatings were sprayed with plasma torch SG-100. Electric power was in range from 27 to 40 kW and spray distance varying from 40 to 70 mm, depending on type of sprayed material.Mechanical properties of hydroxyapatite coatings as-sprayed, as well as soaked in simulated body fluid were tested. Influence of soaking time on coatings hardness was noted, which increases with increasing time of soaking. In case of titania coatings, mechanical and photo-catalytic properties were estimated. Scratch test confirmed high values of cohesion and adhesion. Tested coatings exhibit better photo-catalytic properties than commercial Pilkington Active™ glass. Investigation of coatings based on zirconium oxide concerned on mechanical and thermal transport properties. Instrumented indentation test confirmed very good mechanical properties, up to 3.5 GPa and up to 130 GPa for hardness and elastic modulus, respectively. Values of thermal conductivity of tested coatings were lower than coatings sprayed with conventional methods. Based on conducted studies was found that suspension plasma sprayed coatings exhibit properties, which made possible its application on different fields of technique.