996 resultados para ARM MOVEMENTS


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The posterior inferior frontal gyrus (pIFG) and anterior inferior parietal lobule (aIPL) form the core regions of the human “mirror neuron system” that matches an observed movement onto its internal motor representation. We used event-related functional MRI to examine whether simple intransitive finger movements evoke “mirror activity” in the pIFG and aIPL. In separate sessions, participants either merely observed visuospatial stimuli or responded to them as quickly as possible with a spatially compatible finger movement. A picture of a relaxed hand with static dots on the tip of the index and little finger was continuously presented as high-level baseline. Four types of stimuli were presented in a pseudorandom order: a color change of a dot, a moving finger, a moving dot, or a simultaneous finger-dot movement. Dot movements were spatially and kinematically matched to finger movements. Participants were faster at imitating a finger movement than performing the same movement in response to a moving dot or a color change of a dot. Though imitative responses were facilitated, fMRI revealed no additional “mirror activity” in the pIFG and aIPL during the observation or imitation of finger movements as opposed to observing or responding to a moving dot. Mere observation of a finger movement alone failed to induce significant activation of the pIFG and aIPL. The lack of a signature of “mirror neuron activity” in the inferior frontoparietal cortex is presumably due to specific features of the task which may have favored stimulus–response mapping based on common spatial coding. We propose that the responsiveness of human frontoparietal mirror neuron areas to simple intransitive movements critically depends on the experimental context.

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The human mirror neuron system (MNS) has recently been a major topic of research in cognitive neuroscience. As a very basic reflection of the MNS, human observers are faster at imitating a biological as compared with a non-biological movement. However, it is unclear which cortical areas and their interactions (synchronization) are responsible for this behavioural advantage. We investigated the time course of long-range synchronization within cortical networks during an imitation task in 10 healthy participants by means of whole-head magnetoencephalography (MEG). Extending previous work, we conclude that left ventrolateral premotor, bilateral temporal and parietal areas mediate the observed behavioural advantage of biological movements in close interaction with the basal ganglia and other motor areas (cerebellum, sensorimotor cortex). Besides left ventrolateral premotor cortex, we identified the right temporal pole and the posterior parietal cortex as important junctions for the integration of information from different sources in imitation tasks that are controlled for movement (biological vs. non-biological) and that involve a certain amount of spatial orienting of attention. Finally, we also found the basal ganglia to participate at an early stage in the processing of biological movement, possibly by selecting suitable motor programs that match the stimulus.

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This article reflects on the UK coalition government’s ‘alternative models’ agenda, specifically in terms of the adoption of new models of service delivery by arm’s-length bodies (ALBs). It provides an overview of the alternative models agenda and discusses barriers to implementation. These include practical challenges involved in the set up of alternative models, the role of sponsor departments, and the effective communication of best practice. Finally, the article highlights some issues for further discussion.

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Long term recording of biomedical signals such as ECG, EMG, respiration and other information (e.g. body motion) can improve diagnosis and potentially monitor the evolution of many widespread diseases. However, long term monitoring requires specific solutions, portable and wearable equipment that should be particularly comfortable for patients. The key-issues of portable biomedical instrumentation are: power consumption, long-term sensor stability, comfortable wearing and wireless connectivity. In this scenario, it would be valuable to realize prototypes using available technologies to assess long-term personal monitoring and foster new ways to provide healthcare services. The aim of this work is to discuss the advantages and the drawbacks in long term monitoring of biopotentials and body movements using textile electrodes embedded in clothes. The textile electrodes were embedded into garments; tiny shirt and short were used to acquire electrocardiographic and electromyographic signals. The garment was equipped with low power electronics for signal acquisition and data wireless transmission via Bluetooth. A small, battery powered, biopotential amplifier and three-axes acceleration body monitor was realized. Patient monitor incorporates a microcontroller, analog-to-digital signal conversion at programmable sampling frequencies. The system was able to acquire and to transmit real-time signals, within 10 m range, to any Bluetooth device (including PDA or cellular phone). The electronics were embedded in the shirt resulting comfortable to wear for patients. Small size MEMS 3-axes accelerometers were also integrated. © 2011 IEEE.

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This paper explores the effectiveness of financial management tools in regulating the use of resources by arm’s length bodies (ALBs) in a period of fiscal stress. The paper presents research undertaken into the implementation of a new financial management tool for ALBs in the UK since the 2008 financial crisis. Drawing on conflict ambiguity theory, the paper shows how the effectiveness of such tools is affected by deep-rooted tensions implicit within arm’s length governance. This gives rise to micro-level conflict over the means of achieving fiscal regulation, underpinned by macro-level ambiguity over the logic of governance pursued by the government.

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A new topology of the high frequency alternating current (HFAC) inverter bridge arm is proposed which comprises a coupled inductor, a switching device and an active clamp circuit. Based on it, new single-phase and threephase inverters are proposed and their operating states are analysed along with the traditional H-bridge inverter. Multiphase and multi-level isolated inverters are also developed using the HFAC bridge arm. Furthermore, based on the proposed HFAC, a front-end DC-DC converter is also developed for photovoltaic systems to demonstrate the application of the proposed HFAC converter. Simulation and experimental results from prototype converters are carried out to validate the proposed topologies which can be utilised widely in high frequency power conversion applications such as induction heating and wireless power transfer.