Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-03-10T17:35:32Z No. of bitstreams: 2 Dissertação - Adriana Marcela Fonce Camacho - 2014.pdf: 981401 bytes, checksum: a14522ebe9ae77cf599946d25752f8b4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-14T14:08:40Z (GMT) No. of bitstreams: 2 Dissertação - Adriana Marcela Fonce Camacho - 2014.pdf: 981401 bytes, checksum: a14522ebe9ae77cf599946d25752f8b4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-14T14:08:40Z (GMT). No. of bitstreams: 2 Dissertação - Adriana Marcela Fonce Camacho - 2014.pdf: 981401 bytes, checksum: a14522ebe9ae77cf599946d25752f8b4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-08-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work is based mainly on the Brunder and Godinho article [2] which shows proof of the conjecture of Artin methods using p-adic, although the conjecture is stated on the real numbers which makes the proof is show an equivalence on the field of the number p-adic method with the help of colored variables ya contraction of variables so as to prove the statement, taking the first level and ensuring a nontrivial solution in the following levels. / Este trabalho é baseado principalmente no artigo de Brunder e Godinho [2] o qual mostra a prova da conjetura de Artin usando métodos p-ádicos, ainda que a conjetura se afirma sobre o números reais o que faz a prova é mostrar uma equivalência sobre o corpo dos número p-ádicos com ajuda do método de variáveis coloridas e a contração de variáveis para assim provar a afirmação, tomando o primeiro nível e assim garantindo uma solução não trivial nos níveis seguintes.

L’accouchement prématuré est un problème de santé publique dans le monde et notamment dans les pays économiquement développés avec un taux variant entre 7 et 12 % des naissances. Le diagnostic du risque d’accouchement prématuré est difficile à faire et les outils à notre disposition ont peu évolué ces dernières années. La contraction utérine est la conséquence directe de l’activité électrique au niveau du myomètre. Le type de contraction est lié à l’importance de l’excitabilité cellulaire et de sa diffusion à l’ensemble du myomètre. Le recueil et l’analyse de cette activité électrique par des électrodes de surface est aujourd’hui le seul moyen non invasif d’étudier, pendant la grossesse, les mécanismes qui sont à l’origine de la contraction. L’enregistrement de l’électromyogramme utérin ou électrohystérogramme (EHG) est donc prometteur pour réaliser un diagnostic et une surveillance des femmes à risque d’accouchement prématuré. Dans ce travail de thèse 3 études cliniques ont été réalisées. Dans la première, j’ai étudié différentes électrodes de surface permettant d’enregistrer les signaux électriques. Je propose à la fin de cette première partie un système d’électrodes pour permettre à la fois un enregistrement de qualité et une pose aisée compatible avec une application clinique. Dans la deuxième étude j’ai étudié la détection automatique des contractions par l’EHG avec des résultats encourageants pour l’application clinique et notamment en ambulatoire. Enfin dans la troisième étude j’ai étudié la prédiction du risque d’accouchement prématuré par l’analyse de paramètres électriques issus de l’EHG. Les résultats obtenus permettent d’améliorer la prédiction du risque d’accouchement prématuré par rapport aux outils utilisés en routine. / Premature birth is a public health problem in the world, particularly in economically developed countries with a rate varying between 7% and 12% of births. The diagnosis of the risk of premature labor is difficult to make and the tools at our disposal have changed little in recent years. Uterine contraction is a direct consequence of electrical activity at the level of the myometrium. The type of contraction is related to the importance of cell excitability and its diffusion to the entire myometrium. The analysis of this electrical activity by surface electrodes is currently the only non-invasive way to study the mechanisms that are at the origin of the contraction. The recording of the uterine electromyogram or electrohysterogram (EHG) is therefore promising for the diagnosis and surveillance of women at risk of preterm birth. In this thesis work 3 clinical studies have been carried out. In the first clinical study, different surface electrodes to record electrical signals were tested. I propose at the end of this first part a system of electrodes to allow at the same time a recording of quality and an easy pose compatible with a clinical application. In the second study , the automatic detection of contractions by the El-IG was studied with encouraging results for the clinical application and especially in ambulatory. Finally, in the third clinical experiment, I studied the prediction of the risk of premature delivery by the analysis of electrical parameters extracted from the EHG. The results obtained make it possible to improve the prediction of the risk of premature delivery compared to the tools used routinely.

The main objective of the study was to investigate and simulate skeletal muscleforce production during and after isometric contractions, active muscle lengtheningand active muscle shortening. The motivation behind this work was to improve thedominant model of muscle force generation based on the theories of Hill from 1938. Effects of residual force enhancement and force depression were observed after concentric and eccentric contractions, and also during stretch-shortening cycles. It wasshown that this force modification is not related to lengthening/shortening velocity, butinstead the steady-state force after non-isometric contractions can be well describedby an initial isometric force to which a modification is added. The modification isevaluated from the mechanical work performed by and on the muscle during lengthvariations. The time constants calculated for isometric force redevelopment appearedto be in certain relations with those for initial isometric force development, an observation which extended our basis for muscle modelling. A macroscopic muscular model consisting of a contractile element, and paralleland series elastic elements was supplemented with a history component and adoptedfor mouse soleus muscle experiments. The parameters from the experiment analysis, particularly the force modification after non-isometric contractions and the timeconstants, were reproduced by the simulations. In a step towards a general implementation, the history modification was introduced in the muscluloskeletal model ofOpenSim software, which was then used for simulations of full body movements. / QC 20120525

The purpose of this thesis was to determine whether practice-induced adjustments and retention of a goal directed isometric motor accuracy task were similar between ipsilateral upper and lower limb and whether there is an ipsilateral transfer between upper and lower limbs. In addition, this thesis project aimed to determine whether motor output variability and the activity of the involved agonist and antagonist muscles could predict any of the above stated changes. Sixteen young adults (8 men, 8 women; 22.1 or - 2.1 years) performed 80 trials of goal directed isometric contractions that involved accurately matching a target force of 25% MVC in 200 ms, either with the upper limb or the lower limb followed by the other limb. After an interval of 48 hours, 10 trials similar to the practice trials were performed to examine retention. Feedback of performance was provided in the form of a force-time trajectory along with numerical error values for force and time on each trial. End-point error was quantified as the absolute deviation from the targeted force and time. Motor output variability was quantified as the SD of force, SD of time to peak force and SD of force trajectory. The practice-induced adjustments for force and time endpoint accuracy were similar for the two limbs, however, two days later, retention of the force accuracy was better with the upper limb compared with the lower limb. Practice-induced reduction and practice-to-retention increase in force and time endpoint error were predicted by respective changes in peak force and time to peak force trial-to-trial variability for both limbs. In addition, the changes in accuracy were predicted by the changes in the activity of the involved agonist and antagonist muscles. Nonetheless, the changes in muscle activity differed between the two limbs. The adjustments in muscle activity were also different during the practice session despite the fact that the rate of improvement was similar for the two limbs. Finally, there was an asymmetric transfer of force accuracy from the lower limb to the ipsilateral upper limb, which was associated with the changes in motor output variability. The upper limb, which is inherently less variable as compared to the lower limb, may have retained the task better due to the formation of a stronger muscle synergy (or stronger internal model) to perform the contractions with accuracy. The lower limb, on the other hand may have formed a weaker internal model due to the greater interference from amplified signal-dependent noise (motor output variability) or an alternative motor plan, which may have been concerned primarily with the minimization of motor output variability instead of formation of a muscle synergy to perform the contractions accurately.

The main objective of the study was to investigate skeletal muscle force production during isometric contractions, active muscle stretches and shortenings. The motivation behind this work is to improve the dominant model of muscle contraction force generation based on the theories of Hill. The effect of force modification was observed after concentric and eccentric contractions and also stretch-shortening cycles. It has been shown that this force modification is not related to lengthening/shortening velocity, and the steady-state force after non-isometric contractions can be well described by initial isometric force and mechanical work performed by and on the muscle during length variations. The time constants calculated for isometric force redevelopment appeared to be in certain relations with those for initial isometric force development, an observation which extended our basis for ongoing muscle modeling. The main method of the project consists in two extensive series of experiments on mouse skeletal muscles. Analysis of the first series of experiments, concentric contractions, with an emphasis on the force depression has been presented in Paper 1. Paper 2 is based on contractions with various stretches and shortenings as well as their combination, force modification and its predictor are the quantities of interest. The third part of the project is also based on the second series of experiments. Timing aspects of the force production were calculated there. / QC 20120209

L'objectif de ce travail de thèse est d'étudier d'une part les spécificités de la commande nerveuse lors de la contraction excentrique en explorant les mécanismes impliqués au niveau spinal et d'autre part d'examiner les mécanismes nerveux responsables de la plasticité du système neuromusculaire après un entraînement de force excentrique sous-maximal. A travers ce travail de thèse, nous mettons en évidence la contribution de l'inhibition récurrente à la réduction de l'activation musculaire classiquement observée lors de la contraction excentrique. Par ailleurs, nous montrons que l'inhibition récurrente est majorée lors des contractions sous-maximales indépendamment du mode de contraction. Ces résultats soulignent le rôle important de l'inhibition récurrente dans la spécificité de la commande nerveuse lors de la contraction excentrique. Nous confirmons que le pilotage nerveux de la contraction excentrique peut être modulé par l'entraînement de force excentrique même si les modulations de l'excitabilité spinale semblent dépendre des caractéristiques de l'entraînement. / The purpose of this PhD research is, on the one hand, to study the neural drive specificities during eccentric contractions by exploring the neural mechanisms involved at spinal level and, on the other hand, to examine the neural mechanisms responsible for the modulations of neuromuscular system following a strength submaximal eccentric training. Through this PhD research we highlight the contribution of recurrent inhibition by the Renshaw cell to the decrease of muscular activation typically observed during eccentric contraction. Furthermore, we show that recurrent inhibition is enhanced during submaximal contractions regardless of the contraction type. These results emphasize the important role of recurrent inhibition in the specificity of neural control during eccentric contractions. We confirm that the neural drive of the eccentric contraction may be modulated by eccentric strength training although modulations of spinal excitability seem to depend on the characteristics of training.

Aims: To study the β-adrenoceptor subtypes involved in the relaxation responses to (-)-isoprenaline in carbachol-pre-contracted (CCh) mouse detrusor muscle with intact and denuded mucosa. Methods: Isolated muscle strips from the urinary bladder of male C57BL6 mice or β2-adrenoceptor knockout mice were pre-contracted with CCh, 1 µM and relaxed with increasing concentrations of the β-adrenoceptor (β-AR) agonist (-)-isoprenaline and forskolin. For estimating the β-AR subtypes involved, subtype-selective receptor blockers were used, that is, CGP 20712A (β1-ARs), ICI 118,551 (β2-ARs), and L748,337 (β3-ARs). Results: Unlike in KCl-pre-contracted muscle, the mucosa did not affect the sensitivity of the relaxation response to (-)-isoprenaline in CCh-pre-contracted murine detrusor strips. Increasing concentrations of (-)-isoprenaline produced a biphasic concentration-relaxation response without any difference both during the presence and absence of mucosa. The relaxation fraction produced by low (-)-isoprenaline concentrations was mediated by β2-AR as evidenced by a shift of the concentration-response curve to higher concentrations with ICI 118,551, but not with CGP 20712A and L748,337, and by the absence of this fraction in β2-AR-KO mice. The relaxation response with low sensitivity to (-)-isoprenaline was not affected by any of the β-AR subtype-selective blockers and was the only response detected in detrusor strips from β2-AR-KO mice. Conclusions: In CCh-pre-contracted mouse detrusor, β2-ARs are responsible for the relaxation component with high sensitivity to (-)-isoprenaline as indicated by the conversion of a biphasic into a monophasic CRC with ICI 118,551 or by its absence in β2-AR KO mice. The mucosa does not impair relaxation under these conditions. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

[pt] Um operador definido em um espaço de Hilbert é uniformemente estável se ele converge na topologia da norma para o operador nulo. O problema de Estabilidade Multiplicativa investiga quais são as classes de operadores que estabilizam uniformemente o operador original por uma perturbação multiplicativa. Neste trabalho colocamos este problema no contexto de produto tensorial e investigamos quais as classes que estabilizam multiplicativamente Contrações Fortemente Estáveis sob uma perturbação compacta. Em particular, apresentamos uma solução para o Problema de Estabilidade Multiplicativa para Contrações Fortemente Estáveis. / [en] An operator on a Hilbert space is uniformly stable if it converges to the null operator on the norm topology. The Multiplicative Stabilization Problem investigates which operators classes uniformly stabilize de original operator under multiplicative perturbation. This work consider the previous problem under the tensor product framework and investigates which operators classes multiplicative stabilize Strongly Stable Contraction under compact perturbations. We have established a solution to the Multiplicative Stabilization Problem for Strongly Stable Contractions.

La coactivation est un phénomène musculaire fondamental pour la stabilisation et la protection des articulations lors de contractions volontaires et joue un rôle essentiel dans le contrôle du mouvement. De nombreuses études ont montré que des mécanismes supraspinaux et spinaux contribuent à la régulation de la coactivation musculaire, mais l'implication du cortex moteur primaire (M1) est encore mal connue. Les modulations des oscillations corticales et des interactions cortico-musculaires ont été étudiées lors de contractions isométriques à différents niveaux de forces chez des participants présentant différents niveaux de coactivation musculaire en raison de leur spécialité sportive (entraînement en force (ST) vs. en endurance (ED)). Chez les ST, une moindre coactivation musculaire est associée à une plus grande activation du M1, ce qui pourrait s'expliquer par le contrôle d'un plus grand nombre de muscles, notamment des muscles antagonistes. Grâce à une méthode novatrice pour analyser les interactions cortico-musculaires, nous montrons qu'il existe un couplage entre le M1 est les muscles antagonistes chez l'ensemble des participants et dans toutes les directions de contraction. Cependant, la magnitude des interactions cortico-musculaires avec les muscles antagonistes est plus faible qu'avec les muscles agonistes, ce qui pourrait s'expliquer par une plus grande implication des mécanismes spinaux dans la régulation de la coactivation musculaire. L'estimation des moments musculaires agoniste et antagoniste à l'aide d'un modèle biomécanique EMG-assisté ouvre la perspective d'étudier directement les corrélats cérébraux des moments musculaires. Dans leur ensemble, nos résultats, obtenus à l'aide d'une approche combinant biomécanique et neurosciences, ont mis en évidence l'implication directe du M1 dans la régulation de la coactivation musculaire lors de contractions isométriques volontaires.

A bounded operator T on a complex separable Hilbert space is said to be homogeneous if '(T ) is unitarily equivalent to T for all ' in M•ob, where M•ob is the M•obius group. A complete description of all homogeneous weighted shifts was obtained by Bagchi and Misra. The first examples of irreducible bi-lateral homogeneous 2-shifts were given by Koranyi. We describe all irreducible homogeneous 2-shifts up to unitary equivalence completing the list of homogeneous 2-shifts of Koranyi. After completing the list of all irreducible homogeneous 2-shifts, we show that every homogeneous operator whose associated representation is a direct sum of three copies of a Complementary series representation, is reducible. Moreover, we show that such an operator is either a direct sum of three bi-lateral weighted shifts, each of which is a homogeneous operator or a direct sum of a homogeneous bi-lateral weighted shift and an irreducible bi-lateral 2-shift. It is known that the characteristic function T of a homogeneous contraction T with an associated representation is of the form T (a) = L( a) T (0) R( a); where L and R are projective representations of the M•obius group M•ob with a common multiplier. We give another proof of the \product formula". We point out that the defect operators of a homogeneous contraction in B2(D) are not always quasi-invertible (recall that an operator T is said to be quasi-invertible if T is injective and ran(T ) is dense). We prove that when the defect operators of a homogeneous contraction in B2(D) are not quasi-invertible, the projective representations L and R are unitarily equivalent to the holomorphic Discrete series representations D+ 1 and D++3, respectively. Also, we prove that, when the defect operators of a homogeneous contraction in B2(D) are quasi-invertible, the two representations L and R are unitarily equivalent to certain known pairs of representations D 1; 2 and D +1; 1 ; respectively. These are described explicitly. Let G be either (i) the direct product of n-copies of the bi-holomorphic automorphism group of the disc or (ii) the bi-holomorphic automorphism group of the polydisc Dn: A commuting tuple of bounded operators T = (T1; T2; : : : ; Tn) is said to be homogeneous with respect to G if the joint spectrum of T lies in Dn and '(T); defined using the usual functional calculus, is unitarily equivalent to T for all ' 2 G: We show that a commuting tuple T in the Cowen-Douglas class of rank 1 is homogeneous with respect to G if and only if it is unitarily equivalent to the tuple of the multiplication operators on either the reproducing kernel Hilbert space with reproducing kernel n 1 i=1 (1 ziwi) i or Q n i i n; are positive real numbers, according asQG is as in (i) or 1 ; where ; i, 1 i i=1 (1 z w ) (ii). Finally, we show that a commuting tuple (T1; T2; : : : ; Tn) in the Cowen-Douglas class of rank 2 is homogeneous with respect to M•obn if and only if it is unitarily equivalent to the tuple of the multiplication operators on the reproducing kernel Hilbert space whose reproducing kernel is a product of n 1 rank one kernels and a rank two kernel. We also show that there is no irreducible tuple of operators in B2(Dn), which is homogeneous with respect to the group Aut(Dn):