1000 resultados para Motor Praxeology


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Personality differences based on fine motor precision performance were studied in early stage Parkinson's patients and an age-matched control group under two different test conditions: proprioceptive + visual information and proprioceptive information alone. A comparative data analysis for deviations of three measured movement types (transversal, frontal and sagittal) was done for both hands (dominant and non-dominant) with relation to personality dimensions. There were found significant differences between the two groups in decision making dimension and emotionality. After splitting the data for gender subgroups, some significant differences were found for men but not for women. The differences in fine motor task performance varied, being better in some directions for the Parkinson"s patients and worse in others. The findings may suggest that medication has both positive and negative effects on motor performance and provoke personality changes, being more pronounced in men.

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We report an experiment where participants observed an attack on their virtual body as experienced in an immersive virtual reality (IVR) system. Participants sat by a table with their right hand resting upon it. In IVR, they saw a virtual table that was registered with the real one, and they had a virtual body that substituted their real body seen from a first person perspective. The virtual right hand was collocated with their real right hand. Event-related brain potentials were recorded in two conditions, one where the participant"s virtual hand was attacked with a knife and a control condition where the knife only struck the virtual table. Significantly greater P450 potentials were obtained in the attack condition confirming our expectations that participants had a strong illusion of the virtual hand being their own, which was also strongly supported by questionnaire responses. Higher levels of subjective virtual hand ownership correlated with larger P450 amplitudes. Mu-rhythm event-related desynchronization in the motor cortex and readiness potential (C3C4) negativity were clearly observed when the virtual hand was threatened as would be expected, if the real hand was threatened and the participant tried to avoid harm. Our results support the idea that event-related potentials may provide a promising non-subjective measure of virtual embodiment. They also support previous experiments on pain observation and are placed into context of similar experiments and studies of body perception and body ownership within cognitive neuroscience.

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This booklet is a compilation of notes taken during motor grader operators workshops held at some 20 different locations throughout Iowa during the last two years. It is also the advice of 16 experienced motor grader operators and maintenance foremen (from 14 different counties around Iowa), who serve as instructors and assistant instructors at the "MoGo" workshops. The instructors have all said that they learn as much from the operators who attend the workshops as they impart. Motor grader operators from throughout Iowa have shown us new, innovative and better ways of maintaining gravel roads. This booklet is an attempt to pass on some of these "tips" that we have gathered from Iowa operators. It will need to be revised, corrected, and added to based on the advice we get from you, the operators who do the work here in Iowa.

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OBJECTIVES: In this study, we investigated the structural plasticity of the contralesional motor network in ischemic stroke patients using diffusion magnetic resonance imaging (MRI) and explored a model that combines a MRI-based metric of contralesional network integrity and clinical data to predict functional outcome at 6 months after stroke. METHODS: MRI and clinical examinations were performed in 12 patients in the acute phase, at 1 and 6 months after stroke. Twelve age- and gender-matched controls underwent 2 MRIs 1 month apart. Structural remodeling after stroke was assessed using diffusion MRI with an automated measurement of generalized fractional anisotropy (GFA), which was calculated along connections between contralesional cortical motor areas. The predictive model of poststroke functional outcome was computed using a linear regression of acute GFA measures and the clinical assessment. RESULTS: GFA changes in the contralesional motor tracts were found in all patients and differed significantly from controls (0.001 ≤ p < 0.05). GFA changes in intrahemispheric and interhemispheric motor tracts correlated with age (p ≤ 0.01); those in intrahemispheric motor tracts correlated strongly with clinical scores and stroke sizes (p ≤ 0.001). GFA measured in the acute phase together with a routine motor score and age were a strong predictor of motor outcome at 6 months (r(2) = 0.96, p = 0.0002). CONCLUSION: These findings represent a proof of principle that contralesional diffusion MRI measures may provide reliable information for personalized rehabilitation planning after ischemic motor stroke. Neurology® 2012;79:39-46.

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Background: We report the case of a chronic stroke patient (62 months after injury) showing total absence of motor activity evoked by transcranial magnetic stimulation (TMS) of spared regions of the left motor cortex, but near-to-complete recovery of motor abilities in the affected hand. Case presentation: Multimodal investigations included detailed TMS based motor mapping, motor evoked potentials (MEP), and Cortical Silent period (CSP) as well as functional magnetic resonance imaging (fMRI) of motor activity, MRI based lesion analysis and Diffusion Tensor Imaging (DTI) Tractography of corticospinal tract (CST). Anatomical analysis revealed a left hemisphere subinsular lesion interrupting the descending left CST at the level of the internal capsule. The absence of MEPs after intense TMS pulses to the ipsilesional M1, and the reversible suppression of ongoing electromyographic (EMG) activity (indexed by CSP) demonstrate a weak modulation of subcortical systems by the ipsilesional left frontal cortex, but an inability to induce efficient descending volleys from those cortical locations to right hand and forearm muscles. Functional MRI recordings under grasping and finger tapping patterns involving the affected hand showed slight signs of subcortical recruitment, as compared to the unaffected hand and hemisphere, as well as the expected cortical activations. Conclusions: The potential sources of motor voluntary activity for the affected hand in absence of MEPs are discussed. We conclude that multimodal analysis may contribute to a more accurate prognosis of stroke patients.

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Recent trends (1980-2007) in mortality from road traffic crashes in European countries, and, for comparative purposes, in the USA and Japan were reviewed. Data came from the World Health Organisation database. Age-standardised rates, at all ages and at 15-24, 25-64, >=65 years, were computed. Joinpoint regression analyses to evaluate significant changes in trends were performed. In the European Union as a whole rates declined from 20.2 in 1987 to 13.5/100,000 in 2007 in men, and from 6.3 to 3.7/100,000 in women; European Union rates remained lower than USA, but higher than Japanese ones. In 2007, the highest male rates were in Lithuania (36.7/100,000), the Russian Federation (35.2), Ukraine (29.8), and Latvia (28.5), and the lowest ones in the Netherlands (6.2) and Sweden (6.9); the highest female rates were in the Russian Federation (11.3), Lithuania (9.7), Belarus, Latvia, and Ukraine (around 8), and the lowest ones in Switzerland (1.7), the UK, and Nordic countries (around 2). Mortality from motor vehicle crashes declined in northern and western European countries and - though to a lesser extent - in southern European countries, too. Mortality trends were also favourable in the Czech Republic and Poland since the mid 1990's, whereas they were still upwards in Romania and the Russian Federation. No trend was observed in Hungary and Ukraine. Trends were consistent in various age groups considered. Thus, additional urgent and integrated intervention is required to prevent avoidable deaths from motor vehicle crashes, particularly in selected central and eastern European countries.

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Frontotemporal dementia (FTD) is the second most common degenerative dementia after Alzheimer's disease and its Lewy body variant. Clinical pathology can be subdivided in three main neuropathological subtypes: frontal lobe dementia, Pick's disease and FTD with motor neuron disease (MND), all characterised by distinct histological features. Until recently the presence of ubiquitin-positive intraneuronal inclusions in the dentate gyrus, and the temporal and frontal cortex was usually associated with the MND type. Such inclusions were also observed in a few sporadic cases of FTD without or with parkinsonism (FTDP) in the absence of MND. We present here clinical, neuropathological and immunohistochemical data about a Swiss FTD family with FTDP-like features but without MND. Spongiosis and mild gliosis were observed in the grey matter. No neurofibrillary tangles, Pick bodies, Lewy bodies, senile plaques or prion-positive signals were present. However, ubiquitin-positive intracytoplasmic inclusions were detected in various structures but predominantly in the dentate gyrus. These observations support the existence of a familial form of FTDP with ubiquitin-positive intracytoplasmic inclusions (Swiss FTDP family).

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The integration of electric motors and industrial appliances such as pumps, fans, and compressors is rapidly increasing. For instance, the integration of an electric motor and a centrifugal pump provides cost savings and improved performance characteristics. Material cost savings are achieved when an electric motor is integrated into the shaft of a centrifugal pump, and the motor utilizes the bearings of the pump. This arrangement leads to a smaller configuration that occupies less floor space. The performance characteristics of a pump drive can be improved by using the variable-speed technology. This enables the full speed control of the drive and the absence of a mechanical gearbox and couplers. When using rotational speeds higher than those that can be directly achieved by the network frequency the structure of the rotor has to be mechanically durable. In this thesis the performance characteristics of an axial-flux solid-rotor-core induction motor are determined. The motor studied is a one-rotor-one-stator axial-flux induction motor, and thus, there is only one air-gap between the rotor and the stator. The motor was designed for higher rotational speeds, and therefore a good mechanical strength of the solid-rotor-core rotor is required to withstand the mechanical stresses. The construction of the rotor and the high rotational speeds together produce a feature, which is not typical of traditional induction motors: the dominating loss component of the motor is the rotor eddy current loss. In the case of a typical industrial induction motor instead the dominating loss component is the stator copper loss. In this thesis, several methods to decrease the rotor eddy current losses in the case of axial-flux induction motors are presented. A prototype motor with 45 kW output power at 6000 min-1 was designed and constructed for ascertaining the results obtained from the numerical FEM calculations. In general, this thesis concentrates on the methods for improving the electromagnetic properties of an axial-flux solid-rotor-core induction motor and examines the methods for decreasing the harmonic eddy currents of the rotor. The target is to improve the efficiency of the motor and to reach the efficiency standard of the present-day industrial induction motors equipped with laminated rotors.

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Chronic pain refractory to medical therapy poses a therapeutic challenge. The repetitive Transcranial Magnetic Stimulation (rTMS) and transcranial Direct Current Stimulation (tDCS) modulate brain activity offering a new approach. Current evidence suggests a potential therapeutic efficacy of motor cortex stimulation for the treatment of pain, but does not (yet) support their recommendation for clinical practice. These methods allow to deepen our knowledge in the pathophysiology of chronic pain while providing new therapeutic approaches.

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Resumo: O objetivo deste trabalho foi quantificar o efeito do tipo de diesel e da concentração de biodiesel na mistura combustível sobre as emissões de gases por motor agrícola submetido a diferentes cargas. Foram testados dois tipos de diesel: S10, com baixo teor de enxofre; e S500, com alto teor de enxofre; bem como suas misturas com 5, 10, 15, 20, 50 e 100% de biodiesel. O motor, de quatro cilindros, turboalimentado e com 105 cv de potência máxima, foi submetido a oito modos de operação, sob diferentes rotações e torques. O ensaio seguiu a metodologia prevista na norma NBR ISSO 8174-4:2012, tendo-se analisado as emissões de O2, CO2, NO2, NO, CO e de hidrocarbonetos (HC). Somente as emissões de HC foram influenciadas pelo tipo de diesel utilizado. As emissões de NO2 e O2 aumentaram com o aumento da concentração de biodiesel na mistura, enquanto as emissões de CO2, NO, CO e HC diminuíram. A carga aplicada ao motor esteve diretamente relacionada às emissões, exceto para O2. O combustível S10, com 20% de biodiesel, reduz as emissões, em comparação ao diesel comercial (S500), sem perda no desempenho do motor.

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AIM: The aim of this cross-sectional study was to provide normative data (ordinal scores and timed performances) for gross and fine motor tasks in typically developing children between 3 and 5 years of age using the Zurich Neuromotor Assessment (ZNA). METHOD: Typically developing children (n=101; 48 males, 53 females) between 3 and 5 years of age were enrolled from day-care centres in the greater Zurich area and tested using a modified version of the ZNA; the tests were recorded digitally on video. Intraobserver reliability was assessed on the videos of 20 children by one examiner. Interobserver reliability was assessed by two examiners. Test-retest reliability was performed on an additional 20 children. The modelling approach summarized the data with a linear age effect and an additive term for sex, while incorporating informative missing data in the normative values. Normative data for adaptive motor tasks, pure motor tasks, and static and dynamic balance were calculated with centile curves (for timed performance) and expected ordinal scores (for ordinal scales). RESULTS: Interobserver, intraobserver, and test-retest reliability of tasks were moderate to good. Nearly all tasks showed significant age effects, whereas sex was significant only for stringing beads and hopping on one leg. INTERPRETATION: These results indicate that timed performance and ordinal scales of neuromotor tasks can be reliably measured in preschool children and are characterized by developmental change and high interindividual variability.