182 research outputs found

    Guías clínicas para la cirugía de la epilepsia y de los trastornos del movimiento

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    The guidelines for the surgical treatment of the movement disorders and epilepsy have been performed by the functional and stereotactic group of the Spanish Society of Neurosugery (SENEC). The guidelines are recomendations in terms of indication for surgery including timing and methods. The format are supported by prospective studies based in scientific evidence and the expert opinion of the group

    Dianas quirúrgicas en el tratamiento de enfermedades psiquiátricas. Desde el movimiento a las emociones

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    Deep brain stimulation (DBS) for psychiatric disorders refractory to conventional treatments are currently been performed based in the knowledgment obtained in the motor disorder surgery and mainly in Parkinson´s disease. Depression, obsessive-compulsive disorder (OCD) and Tourette syndrome, all of them are cortico-striato-thalamo-cortical pathological process involved in the limbic loop of the basal ganglia. This review describes the different targets in these pathological neuro-psychiatric disorders. For OCD there are currently two targets, ventral striatum (VS) Accumbens nucleus (Nacc) and the subthalamic nucleus (STN). In refractory depression the subgenual area (25 Brodmann area) and VS/Nacc. For Tourette syndrome the ventralis oralis internus and centromedianum/ parafascicularis of the thalamus (Voi and CM/Pf) and the internal part of the globus pallidus (GPi). Currently there are no specific surgical target for each pathological disorder because clinical results reported are very similar after stimulation surgery. In other point, a selected surgical target also may improve different pathologies

    El discurso audiovisual en la divulgación de la ciencia de la UNAM: la construcción de un modelo de ciencia para divulgar

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    Trabajo de tesis en el que se estudian las capacidades, limitaciones y características expresivas de la producción audiovisual en el ámbito científico, específicamente en la divulgación de la ciencia. En esta investigación se averigua cuál es la noción de ciencia dominante contenida en los audiovisuales de divulgación científica de la UNAM. Para encontrarla se explora en el discurso de una selección de videos producidos por la Dirección General de Divulgación de la Ciencia, principal responsable de la divulgación científica en la Universidad Nacional. Con este proyecto se espera colocar en la mira de los investigadores la forma y contenidos de la divulgación científica audiovisual que se realiza en la UNAM para que así la comunidad académica comience a involucrarse en los procesos de creación de dichos audiovisuales y en el uso de las herramientas cinematográficas, que tienen la capacidad de potenciar los esfuerzos comunicativos realizados por dicha comunidad

    Encontros e desencontros da formação em serviço

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    Neste texto analisamos as tensões entre docentes de uma escola pública – em suas tentativas de mudanças no currículo por meio da construção de Projetos de Trabalho – e os gestores responsáveis pela formação em serviço, com seus aportes conceituais. Os encontros de formação foram marcados por mudanças na política educacional da cidade de Belo Horizonte, Brasil. Para compreensão das transformações que ocorreram nas produções curriculares dos professores utilizamos conceitos retirados do referencial teórico de René Kaës. Nosso objetivo é obter indicações que possibilitem compreender melhor a formação em serviço, tendo a escola como espaço privilegiado de formação. Os dilemas enfrentados, se por um lado mostram as dificuldades inerentes à construção de projetos coletivos, por outro levam ao reconhecimento, pela comunidade escolar, dos atores envolvidos neste processo

    Antioxidant peroxiredoxin 6 protein rescues toxicity due to oxidative stress and cellular hypoxia in vitro, and attenuates prion-related pathology in vivo

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    Protein misfolding, mitochondrial dysfunction and oxidative stress are common pathomechanisms that underlie neurodegenerative diseases. In prion disease, central to these processes is the post-translational transformation of cellular prion protein (PrPc) to the aberrant conformationally altered isoform; PrPSc. This can trigger oxidative reactions and impair mitochondrial function by increasing levels of peroxynitrite, causing damage through formation of hydroxyl radicals or via nitration of tyrosine residues on proteins. The 6 member Peroxiredoxin (Prdx) family of redox proteins are thought to be critical protectors against oxidative stress via reduction of H2O2, hydroperoxides and peroxynitrite. In our in vitro studies cellular metabolism of SK-N-SH human neuroblastoma cells was significantly decreased in the presence of H2O2 (oxidative stressor) or CoCl2 (cellular hypoxia), but was rescued by treatment with exogenous Prdx6, suggesting that its protective action is in part mediated through a direct action. We also show that CoCl2-induced apoptosis was significantly decreased by treatment with exogenous Prdx6. We proposed a redox regulator role for Prdx6 in regulating and maintaining cellular homeostasis via its ability to control ROS levels that could otherwise accelerate the emergence of prion-related neuropathology. To confirm this, we established prion disease in mice with and without astrocyte-specific antioxidant protein Prdx6, and demonstrated that expression of Prdx6 protein in Prdx6 Tg ME7-animals reduced severity of the behavioural deficit, decreased neuropathology and increased survival time compared to Prdx6 KO ME7-animals. We conclude that antioxidant Prdx6 attenuates prion-related neuropathology, and propose that augmentation of endogenous Prdx6 protein represents an attractive adjunct therapeutic approach for neurodegenerative diseases

    Revisión crítica de la estimulación subtalámica en la enfermedad de Parkinson

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    The authors critically review subthalamic nucleus (STN) stimulation for Parkinson's disease (PD) at long follow-up (3-5 years). Subthalamic stimulation induce a significant improvement during the "off" medication in the assessment motor score UPDRS (Unified Parkinson Disease Rating Scale) 3-5 years after surgery. Results show that the benefits obtained in tremor, rigidity, bradykinesia, dyskinesias induced by medication and levodopa reduction are significantly maintained during long term. The improvement in other clinical signs as gait and postural stability at long follow-up are not maintained comparing with the benefits obtained one year after surgery. A high percentage of patients show a cognitive disturbance during the follow-up period that may be correlated with the disease progression. The conclusion is that bilateral STN stimulation is an effective treatment for PD patients at long term but it should be considered earlier in the course of P

    Universal quantum computation by holonomic and nonlocal gates with imperfections

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    We present a nonlocal construction of universal gates by means of holonomic (geometric) quantum teleportation. The effect of the errors from imperfect control of the classical parameters, the looping variation of which builds up holonomic gates, is investigated. Additionally, the influence of quantum decoherence on holonomic teleportation used as a computational primitive is studied. Advantages of the holonomic implementation with respect to control errors and dissipation are presented.Comment: 5 pages, 2 figures, REVTEX, title changed, typos correcte

    An Experimental Realization of Quantum-vacuum Geometric Phases by Using the Gyrotropic-medium Optical Fiber

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    The connection between the quantum-vacuum geometric phases (which originates from the vacuum zero-point electromagnetic fluctuation) and the non-normal product procedure is considered in the present Letter. In order to investigate this physically interesting geometric phases at quantum-vacuum level, we suggest an experimentally feasible scheme to test it by means of a noncoplanarly curved fiber made of gyrotropic media. A remarkable feature of the present experimental realization is that one can easily extract the nonvanishing and nontrivial quantum-vacuum geometric phases of left- and/or right- handed circularly polarized light from the vanishing and trivial total quantum-vacuum geometric phases.Comment: 4 pages, Late

    The Effects of Degraded Digital Instrumentation and Control Systems on Human-system Interfaces and Operator Performance: HFE Review Guidance and Technical Basis

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    New and advanced reactors will use integrated digital instrumentation and control (I&C) systems to support operators in their monitoring and control functions. Even though digital systems are typically highly reliable, their potential for degradation or failure could significantly affect operator performance and, consequently, impact plant safety. The U.S. Nuclear Regulatory Commission (NRC) supported this research project to investigate the effects of degraded I&C systems on human performance and plant operations. The objective was to develop human factors engineering (HFE) review guidance addressing the detection and management of degraded digital I&C conditions by plant operators. We reviewed pertinent standards and guidelines, empirical studies, and plant operating experience. In addition, we conducted an evaluation of the potential effects of selected failure modes of the digital feedwater system on human-system interfaces (HSIs) and operator performance. The results indicated that I&C degradations are prevalent in plants employing digital systems and the overall effects on plant behavior can be significant, such as causing a reactor trip or causing equipment to operate unexpectedly. I&C degradations can impact the HSIs used by operators to monitor and control the plant. For example, sensor degradations can make displays difficult to interpret and can sometimes mislead operators by making it appear that a process disturbance has occurred. We used the information obtained as the technical basis upon which to develop HFE review guidance. The guidance addresses the treatment of degraded I&C conditions as part of the design process and the HSI features and functions that support operators to monitor I&C performance and manage I&C degradations when they occur. In addition, we identified topics for future research
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