278 research outputs found

    An estimation of the stability and the localisability functions of multistable processes

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    Multistable processes are tangent at each point to a stable process, but where the index of stability and the index of localisability varies along the path. In this work, we give two estimators of the stability and the localisability functions, and we prove the consistency of those two estimators. We illustrate these convergences with two classical examples, the Levy multistable process and the Linear Multifractional Multistable Motion

    The Hausdorff dimension of the range of the LĂ©vy multistable processes

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    International audienceWe compute the Hausdorff dimension of the image X(E) of a non random Borel set E ⊂ [0, 1], where X is a LĂ©vy multistable process in R. This extends the case where X is a classical stable LĂ©vy process by letting the stability exponent α be a smooth function, which leads to non-homogeneous processes because their increments are not stationary and not necessarily independent. Contrary to the situation where the stability parameter is a constant, the dimension depends on the version of the multistable LĂ©vy motion when the process has an infinite first moment

    Localisable moving average stable and multistable processes

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    We study a particular class of moving average processes which possess a property called localisability. This means that, at any given point, they admit a ``tangent process'', in a suitable sense. We give general conditions on the kernel g defining the moving average which ensures that the process is localisable and we characterize the nature of the associated tangent processes. Examples include the reverse Ornstein-Uhlenbeck process and the multistable reverse Ornstein-Uhlenbeck process. In the latter case, the tangent process is, at each time t, a L\'evy stable motion with stability index possibly varying with t. We also consider the problem of path synthesis, for which we give both theoretical results and numerical simulations

    Exponential inequalities for the supremum of some counting processes and their square martingales

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    We establish exponential inequalities for the supremum of martingales and square martingales obtained from counting processes, as well as for the oscillation modulus of these processes. Our inequalities, that play a decisive role in the control of errors in statistical procedures, apply to general non-explosive counting processes including Poisson, Hawkes and Cox models. Some applications for UU-statistics are discussed

    Odontoblasto : uma célula sensorial ao serviço na nocicepção

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    Dissertação para obtenção do grau de Mestre no Instituto UniversitĂĄrio Egas MonizO odontoblasto diferencia-se durante a odontogĂ©nese e desempenha diferentes funçÔes durante toda a vida do ĂłrgĂŁo dental. Contribuem primeiro para a formação e mineralização do dente, garantindo a proteção do dente pela produção de dentina reacional. Estas cĂ©lulas ciliadas tambĂ©m parecem desempenhar um papel na transmissĂŁo da dor. A sua localização espacial Ășnica, em estreita relação com as terminaçÔes nervosas da polpa, sugere que possam desempenhar um papel fundamental na transdução sensorial dos eventos que ocorrem no interior da dentina. Esta revisĂŁo narrativa pretende estudar a sensorialidade potencial dos odontoblastos, analisando a expressĂŁo de receptores sensoriais e mecanismos moleculares subjacentes, permitindo a percepção e transmissĂŁo de sinais nociceptivos da dor dentinĂĄria. Ao nĂ­vel dos mĂ©todos, para esta revisĂŁo narrativa, foi feita uma pesquisa bibliogrĂĄfica, utilizando os motores de pesquisa Pubmed/MEDLINE, Science Direct, Scopus, Cochrane Library e outras fontes secundĂĄrias. UtilizĂĄmos artigos em portuguĂȘs, espanhol, inglĂȘs e francĂȘs disponĂ­veis em texto completo publicados nos Ășltimos 15 anos e ainda outros estudos baseados em evidĂȘncias.The odontoblast differentiates itself during dentistry and performs different functions throughout the life of the dental organ. They first contribute to the formation and mineralization of the tooth, ensuring the protection of the tooth by the production of reactional dentin. These ciliated cells also seem to play a role in the transmission of pain. Their unique spatial location, in close relationship with the nerve endings of the pulp, suggests that they can play a key role in the sensory transduction of events occurring inside the dentin. This narrative review aims to study the potential sensoriality of odontoblasts by analysing the expression of sensory receptors and underlying molecular mechanisms, allowing the perception and transmission of nociceptive signals of dentin pain. In terms of methods, for this narrative review, a bibliographic search was made using Pubmed/MEDLINE, Science Direct, Scopus, Cochrane Library and other secondary sources. We have used articles in Portuguese, Spanish, English and French available in full text published in the last 15 years as well as other evidence-based studies
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