933 resultados para mesh: Neurophysiology
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Objectives: To investigate the clinical correlates of frontal intermittent rhythmic delta activity (FIRDA). Methods: we prospectively assessed all EEG studies recorded in our center over 3 months for the presence of frontal intermittent rhythmic delta activity (FIRDA). The FIRDA group was compared with a randomly selected control group from among EEGs recorded during the same period. Comparisons among FIRDA and non-FIRDA groups were performed using uni- and multi-variate analyses. Results: We found 36 patients with FIRDA among 559 EEG recordings (6%); the control group consisted of 80 subjects. While epilepsy was more frequent in the control group, structural brain lesions and encephalopathy were independently associated with the occurrence of FIRDA, but we could not identify any specific etiology. Asymmetric FIRDA was associated with an underlying brain lesion. Occasionally, FIRDA was recorded in otherwise healthy subjects during hyperventilation. Conclusion: FIRDA appears more common than previously reported, and is associated with a wide range of lesions and encephalopathic conditions. Significance: FIRDA occurrence should prompt investigations for toxic-metabolic disturbances and for structural lesions (particularly if asymmetric), but does not suggest an epileptic predilection.
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A targeted approach is being used in the Iowa Great Lakes Watershed with a keystone project featured within this project application in the heavily urbanized Center Lake Watershed. As identified in the Iowa Great Lakes Watershed Management Plan, urban runoff is the only remaining watershed concern in the Center Lake Watershed as the map in the attachments clearly shows. Fully one third of the watershed concerns of Center Lake will be treated through the installation of 7 keystone urban practices and will remove 63 pounds of phosphorous from entering the lake annually. Due to the interconnectedness of the Iowa Great Lakes (IGL), the watershed has been broken down into sub units called Resource Management Areas (RMA's) for priority practice implementation. This project will mesh with the existing Iowa Great Lakes Watershed Management Plan by reducing pollutant loads from the highest priority RMA's which are resulting in impaired water bodies. The majority of the funding needed for the specific practices specified in this proposal has already been secured through the Iowa DNR Section 319 and Lake Restoration Programs, The Water Quality Commission and the City of Spirit Lake. This funding request will simply bring the overall cost of these keystone practices into the range of affordability for the committed funders and the City of Spirit Lake
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We consider a methodology to optimally obtain reconfigurations of spacecraft formations. It is based on the discretization of the time interval in subintervals (called the mesh) and the obtainment of local solutions on them as a result of a variational method. Applied to a libration point orbit scenario, in this work we focus on how to find optimal meshes using an adaptive remeshing procedure and on the determination of the parameter that governs it
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Exposure to solar ultraviolet (UV) light is the main causative factor for skin cancer. UV exposure depends on environmental and individual factors. Individual exposure data remain scarce and development of alternative assessment methods is greatly needed. We developed a model simulating human exposure to solar UV. The model predicts the dose and distribution of UV exposure received on the basis of ground irradiation and morphological data. Standard 3D computer graphics techniques were adapted to develop a rendering engine that estimates the solar exposure of a virtual manikin depicted as a triangle mesh surface. The amount of solar energy received by each triangle was calculated, taking into account reflected, direct and diffuse radiation, and shading from other body parts. Dosimetric measurements (n = 54) were conducted in field conditions using a foam manikin as surrogate for an exposed individual. Dosimetric results were compared to the model predictions. The model predicted exposure to solar UV adequately. The symmetric mean absolute percentage error was 13%. Half of the predictions were within 17% range of the measurements. This model provides a tool to assess outdoor occupational and recreational UV exposures, without necessitating time-consuming individual dosimetry, with numerous potential uses in skin cancer prevention and research.
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O objetivo deste trabalho foi determinar a composição química, estimar o conteúdo de compostos fenólicos solúveis totais e de fitatos, e avaliar a capacidade antioxidante de grãos integrais de gergelim (Sesamum indicum) creme e preto. Amostras de ambos os tipos de grão foram submetidas a tratamento térmico em estufa de circulação de ar a 150ºC por 10 min e trituradas até granulometria de 20 mesh. O gergelim creme apresentou maior teor de lipídios, carboidratos, fibra alimentar solúvel e valor calórico, enquanto o gergelim preto apresentou maior teor de fibras alimentares insolúvel e total. O gergelim preto apresentou teor de compostos fenólicos solúveis totais de 261,9±7,5 mg em equivalente de ácido gálico (EAG) por 100 g de farinha, aproximadamente duas vezes superior ao do gergelim creme (147,5±31,7 mg por 100 g de EAG). O teor de fitatos do gergelim creme foi duas vezes inferior ao do gergelim preto (0,66±0,06 e 1,36±0,04 g por 100 g de ácido fítico, respectivamente). O gergelim preto apresenta maior potencial funcional relacionado à atividade antioxidante. Contudo, ambos os tipos de gergelim analisados podem ser considerados fontes de compostos antioxidantes naturais.
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BACKGROUND: Several recently developed therapies targeting motor disabilities in stroke sufferers have shown to be more effective than standard neurorehabilitation approaches. In this context, several basic studies demonstrated that music training produces rapid neuroplastic changes in motor-related brain areas. Music-supported therapy has been recently developed as a new motor rehabilitation intervention. METHODS AND RESULTS: In order to explore the plasticity effects of music-supported therapy, this therapeutic intervention was applied to twenty chronic stroke patients. Before and after the music-supported therapy, transcranial magnetic stimulation was applied for the assessment of excitability changes in the motor cortex and a 3D movement analyzer was used for the assessment of motor performance parameters such as velocity, acceleration and smoothness in a set of diadochokinetic movement tasks. Our results suggest that the music-supported therapy produces changes in cortical plasticity leading the improvement of the subjects' motor performance. CONCLUSION: Our findings represent the first evidence of the neurophysiological changes induced by this therapy in chronic stroke patients, and their link with the amelioration of motor performance. Further studies are needed to confirm our observations.
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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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Controversial results have been reported concerning the neural mechanisms involved in the processing of rewards and punishments. On the one hand, there is evidence suggesting that monetary gains and losses activate a similar fronto-subcortical network. On the other hand, results of recent studies imply that reward and punishment may engage distinct neural mechanisms. Using functional magnetic resonance imaging (fMRI) we investigated both regional and interregional functional connectivity patterns while participants performed a gambling task featuring unexpectedly high monetary gains and losses. Classical univariate statistical analysis showed that monetary gains and losses activated a similar fronto-striatallimbic network, in which main activation peaks were observed bilaterally in the ventral striatum. Functional connectivity analysis showed similar responses for gain and loss conditions in the insular cortex, the amygdala, and the hippocampus that correlated with the activity observed in the seed region ventral striatum, with the connectivity to the amygdala appearing more pronounced after losses. Larger functional connectivity was found to the medial orbitofrontal cortex for negative outcomes. The fact that different functional patterns were obtained with both analyses suggests that the brain activations observed in the classical univariate approach identifi es the involvement of different functional networks in the current task. These results stress the importance of studying functional connectivity in addition to standard fMRI analysis in reward-related studies.
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Playing a musical instrument demands the engagement of different neural systems. Recent studies about the musician"s brain and musical training highlight that this activity requires the close interaction between motor and somatosensory systems. Moreover, neuroplastic changes have been reported in motor-related areas after short and long-term musical training. Because of its capacity to promote neuroplastic changes, music has been used in the context of stroke neurorehabilitation. The majority of patients suffering from a stroke have motor impairments, preventing them to live independently. Thus, there is an increasing demand for effective restorative interventions for neurological deficits. Music-supported Therapy (MST) has been recently developed to restore motor deficits. We report data of a selected sample of stroke patients who have been enrolled in a MST program (1 month intense music learning). Prior to and after the therapy, patients were evaluated with different behavioral motor tests. Transcranial Magnetic Stimulation (TMS) was applied to evaluate changes in the sensorimotor representations underlying the motor gains observed. Several parameters of excitability of the motor cortex were assessed as well as the cortical somatotopic representation of a muscle in the affected hand. Our results revealed that participants obtained significant motor improvements in the paretic hand and those changes were accompanied by changes in the excitability of the motor cortex. Thus, MST leads to neuroplastic changes in the motor cortex of stroke patients which may explain its efficacy.
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Playing a musical instrument demands the engagement of different neural systems. Recent studies about the musician"s brain and musical training highlight that this activity requires the close interaction between motor and somatosensory systems. Moreover, neuroplastic changes have been reported in motor-related areas after short and long-term musical training. Because of its capacity to promote neuroplastic changes, music has been used in the context of stroke neurorehabilitation. The majority of patients suffering from a stroke have motor impairments, preventing them to live independently. Thus, there is an increasing demand for effective restorative interventions for neurological deficits. Music-supported Therapy (MST) has been recently developed to restore motor deficits. We report data of a selected sample of stroke patients who have been enrolled in a MST program (1 month intense music learning). Prior to and after the therapy, patients were evaluated with different behavioral motor tests. Transcranial Magnetic Stimulation (TMS) was applied to evaluate changes in the sensorimotor representations underlying the motor gains observed. Several parameters of excitability of the motor cortex were assessed as well as the cortical somatotopic representation of a muscle in the affected hand. Our results revealed that participants obtained significant motor improvements in the paretic hand and those changes were accompanied by changes in the excitability of the motor cortex. Thus, MST leads to neuroplastic changes in the motor cortex of stroke patients which may explain its efficacy.
Resumo:
Playing a musical instrument demands the engagement of different neural systems. Recent studies about the musician"s brain and musical training highlight that this activity requires the close interaction between motor and somatosensory systems. Moreover, neuroplastic changes have been reported in motor-related areas after short and long-term musical training. Because of its capacity to promote neuroplastic changes, music has been used in the context of stroke neurorehabilitation. The majority of patients suffering from a stroke have motor impairments, preventing them to live independently. Thus, there is an increasing demand for effective restorative interventions for neurological deficits. Music-supported Therapy (MST) has been recently developed to restore motor deficits. We report data of a selected sample of stroke patients who have been enrolled in a MST program (1 month intense music learning). Prior to and after the therapy, patients were evaluated with different behavioral motor tests. Transcranial Magnetic Stimulation (TMS) was applied to evaluate changes in the sensorimotor representations underlying the motor gains observed. Several parameters of excitability of the motor cortex were assessed as well as the cortical somatotopic representation of a muscle in the affected hand. Our results revealed that participants obtained significant motor improvements in the paretic hand and those changes were accompanied by changes in the excitability of the motor cortex. Thus, MST leads to neuroplastic changes in the motor cortex of stroke patients which may explain its efficacy.
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Enterocystoplasty and gastrocystoplasty have been developed to restore adequate bladder capacity but they still result in the undesired harmful contact of urine with the intestinal mucosa. In an attempt to prevent this nonphysiological interface we performed several modified enterocystoplasties in the mini-pig model using a pedicled, detubularized, de-epithelialized sigmoid patch. Five techniques of patch coverage were used to evaluate urothelial growth or survival on the sigmoid patch. All but 1 patch had intestinal mucosa remnants with mucocele formation. When no coverage was applied or a biodegradable polyglactin mesh was temporarily covering the pedicled, detubularized, de-epithelialized sigmoid patch, severe shrinkage occurred. Partial cover with autologous urothelium islets seemed to decrease shrinkage. Adequate urothelium survival and satisfactory elastic properties of the patch were observed when total cover of the sigmoid patch was achieved with a sheet of homologous urothelium recovering autologous urothelial islets or when the patch was applied to protruding urothelium obtained following sagittal posterior detrusor myotomy.
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Exposure to solar ultraviolet (UV) radiation is the main causative factor for skin cancer. UV exposure depends on environmental and individual factors, but individual exposure data remain scarce. UV irradiance is monitored via different techniques including ground measurements and satellite observations. However it is difficult to translate such observations into human UV exposure or dose because of confounding factors (shape of the exposed surface, shading, behavior, etc.) A collaboration between public health institutions, a meteorological office and an institute specialized in computing techniques developed a model predicting the dose and distribution of UV exposure on the basis of ground irradiation and morphological data. Standard 3D computer graphics techniques were adapted to develop this tool, which estimates solar exposure of a virtual manikin depicted as a triangle mesh surface. The amount of solar energy received by various body locations is computed for direct, diffuse and reflected radiation separately. The radiation components are deduced from corresponding measurements of UV irradiance, and the related UV dose received by each triangle of the virtual manikin is computed accounting for shading by other body parts and eventual protection measures. The model was verified with dosimetric measurements (n=54) in field conditions using a foam manikin as surrogate for an exposed individual. Dosimetric results were compared to the model predictions. The model predicted exposure to solar UV adequately. The symmetric mean absolute percentage error was 13%. Half of the predictions were within 17% range of the measurements. This model allows assessing outdoor occupational and recreational UV exposures, without necessitating time-consuming individual dosimetry, with numerous potential uses in skin cancer prevention and research. Using this tool, we investigated solar UV exposure patterns with respect to the relative contribution of the direct, diffuse and reflected radiation. We assessed exposure doses for various body parts and exposure scenarios of a standing individual (static and dynamic postures). As input, the model used erythemally-weighted ground irradiance data measured in 2009 at Payerne, Switzerland. A year-round daily exposure (8 am to 5 pm) without protection was assumed. For most anatomical sites, mean daily doses were high (typically 6.2-14.6 SED) and exceeded recommended exposure values. Direct exposure was important during specific periods (e.g. midday during summer), but contributed moderately to the annual dose, ranging from 15 to 24% for vertical and horizontal body parts, respectively. Diffuse irradiation explained about 80% of the cumulative annual exposure dose. Acute diffuse exposures were also obtained for cloudy summer days. The importance of diffuse UV radiation should not be underestimated when advocating preventive measures. Messages focused on avoiding acute direct exposures may be of limited efficiency to prevent skin cancers associated with chronic exposure (e.g., squamous cell carcinomas).
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In this paper, an advanced technique for the generation of deformation maps using synthetic aperture radar (SAR) data is presented. The algorithm estimates the linear and nonlinear components of the displacement, the error of the digital elevation model (DEM) used to cancel the topographic terms, and the atmospheric artifacts from a reduced set of low spatial resolution interferograms. The pixel candidates are selected from those presenting a good coherence level in the whole set of interferograms and the resulting nonuniform mesh tessellated with the Delauney triangulation to establish connections among them. The linear component of movement and DEM error are estimated adjusting a linear model to the data only on the connections. Later on, this information, once unwrapped to retrieve the absolute values, is used to calculate the nonlinear component of movement and atmospheric artifacts with alternate filtering techniques in both the temporal and spatial domains. The method presents high flexibility with respect to the required number of images and the baselines length. However, better results are obtained with large datasets of short baseline interferograms. The technique has been tested with European Remote Sensing SAR data from an area of Catalonia (Spain) and validated with on-field precise leveling measurements.
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INTRODUCTION: Hypospadias is associated with anomalies of the urinary tract, but the exact prevalence and significance of these anomalies are still controversial. OBJECTIVES: To assess the percentage of patients with hypospadias and associated urological anomalies, either requiring or not requiring medical or surgical attention. MATERIAL AND METHODS: We searched several databases using the following Mesh terms: hypospadias AND urination, ultrasonography, urinary tract/abnormalities, urinary bladder/radiography, ureteral obstruction, hydronephrosis or vesico-ureteral reflux. Type of uroradiological studies performed, type of urological anomalies, medical or surgical interventions, number of patients available, enrolled and undergoing uroradiological studies and number of patients with abnormal uroradiological exams were recorded. RESULTS: We found 24 studies. Four studies included 100% of available patients. In the other ones, the percentage of patients undergoing uroradiological screening varied from 12 to 82%. Frequency of anomalies varied from 0 to 56%. The most common anomalies were kidney position anomalies, vesico-ureteral reflux and hydronephrosis. CONCLUSIONS: The data published about screening patients with hypospadias for associated anomalies of their urinary tract are of poor quality. The clinical significance of the anomalies found is difficult to evaluate. We found no relationship between the severity of the hypospadias and associated anomalies of the upper or lower urinary tract.