227 research outputs found

    Proprioceptive feedback facilitates motor imagery-related operant learning of sensorimotor β-band modulation

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    Motor imagery (MI) activates the sensorimotor system independent of actual movements and might be facilitated by neurofeedback. Knowledge on the interaction between feedback modality and the involved frequency bands during MI-related brain self-regulation is still scarce. Previous studies compared the cortical activity during the MI task with concurrent feedback (MI with feedback condition) to cortical activity during the relaxation task where no feedback was provided (relaxation without feedback condition). The observed differences might, therefore, be related to either the task or the feedback. A proper comparison would necessitate studying a relaxation condition with feedback and a MI task condition without feedback as well. Right-handed healthy subjects performed two tasks, i.e., MI and relaxation, in alternating order. Each of the tasks (MI vs. relaxation) was studied with and without feedback. The respective event-driven oscillatory activity, i.e., sensorimotor desynchronization (during MI) or synchronization (during relaxation), was rewarded with contingent feedback. Importantly, feedback onset was delayed to study the task-related cortical activity in the absence of feedback provision during the delay period. The reward modality was alternated every 15 trials between proprioceptive and visual feedback. Proprioceptive input was superior to visual input to increase the range of task-related spectral perturbations in the α- and β-band, and was necessary to consistently achieve MI-related sensorimotor desynchronization (ERD) significantly below baseline. These effects occurred in task periods without feedback as well. The increased accuracy and duration of learned brain self-regulation achieved in the proprioceptive condition was specific to the β-band. MI-related operant learning of brain self-regulation is facilitated by proprioceptive feedback and mediated in the sensorimotor β-band

    Определение содержания тетрациклина в молоке методом капиллярного электрофореза

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    Mentalizing, i.e. the process of inferring another person's mental state, is thought to be primarily subserved by three brain regions, the VMPFC (ventromedial prefrontal cortex), precuneus and TPJ (temporo-parietal junction). However, it is still unclear what the exact roles of these regions in mentalizing are. Here, we compare activity within, and functional connectivity between, the VMPFC, precuneus and TPJ during two different mentalizing tasks. Specifically, we examine whether inferring another person's emotion (“emotion mentalizing”) and inferring another person's intention (“intention mentalizing”) activate similar or distinct subregions within the VMPFC, precuneus and TPJ, and whether these different kinds of mentalizing are associated with different patterns of functional connectivity between these regions. Our results indicate that emotion mentalizing and intention mentalizing activate partly distinct subregions of the right and left TPJ that can be spatially separated across participants. These subregions also showed different patterns of functional connectivity with the VMPFC: a more anterior region of the right and left TPJ, which was more strongly activated during emotion mentalizing, showed stronger functional connectivity with the VMPFC, particularly during emotion mentalizing, than a more posterior region that was more strongly activated during intention mentalizing. Critically, this double dissociation became evident only when the fine-scale distribution of activity within activated regions was analysed, and despite the fact that there was also a significant overlap of activity during the two tasks. Our findings provide first evidence that different neural modules might have evolved within the TPJ that show distinct patterns of functional connectivity and might subserve slightly different subfunctions of mentalizing

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    Abstract. Brain-Computer Interfaces based on electrocorticography (ECoG) or electroencephalography (EEG), in combination with robot-assisted active physical therapy, may support traditional rehabilitation procedures for patients with severe motor impairment due to cerebrovascular brain damage caused by stroke. In this short report, we briefly review the state-of-the art in this exciting new field, give an overview of the work carried out at the Max Planck Institute for Biological Cybernetics and the University of Tübingen, and discuss challenges that need to be addressed in order to move from basic research to clinical studies. Current rehabilitation methods for patients with severe motor impairment due to cerebrovascular brain damage are limited in providing significant long-term functional recovery. In stroke patients, functional recovery beyond one year post-stroke is rare (Johnston et al. [2004]), and functional independence often displays a long-term decline (Dhamoon et al. [2009]). As such, novel strategies in stroke rehabilitation are required. Robot-assisted physical therapy (Riener et al. [2005]) and motor imagery (Dijkerman et al. [2004], Page et al. [2007]) have been shown to be beneficial in stroke rehabilitation

    Gyrate atrophy of the choroid and retina with hyper-ornithinemia responsive to vitamin B6: a case report

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    <p>Abstract</p> <p>Background</p> <p>Gyrate atrophy of the retina and choroid is a rare autosomal recessive inherited disease, characterized by progressive chorioretinal atrophy that results in progressive deterioration of peripheral and night vision and leading to blindness.</p> <p>Case presentation</p> <p>This report presents a case of a 28-year-old man consulting for a progressive fall of visual acuity with hemeralopia. Eye fundoscopy showed regions of confluent rounded chorioretinal atrophy. The visual field and retinal angiography were altered. A high level of plasma ornithine (629 nmol/mL) was detected and a diagnosis of gyrate atrophy of the retina and choroid was made. The patient was treated with high dose Pyridoxine supplement (300 mg/d for 6 months) and the ornithine level of his serum was successfully reduced.</p> <p>Conclusion</p> <p>The exact mechanism of chorioretinal atrophy in hyper-ornithinemia is not known and a small percentage of the affected people respond to Vitamin B6 supplementation.</p

    Predictive factors for beneficial application of high-frequency electromagnetics for tumour vaporization and coagulation in neurosurgery

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    <p>Abstract</p> <p>Objective</p> <p>To identify preoperative and intraoperative factors and conditions that predicts the beneficial application of a high-frequency electromagnetic field (EMF) system for tumor vaporization and coagulation.</p> <p>Methods</p> <p>One hundred three subsequent patients with brain tumors were microsurgically treated using the EMF system in addition to the standard neurosurgical instrumentarium. A multivariate analysis was performed regarding the usefulness (ineffective/useful/very helpful/essential) of the new technology for tumor vaporization and coagulation, with respect to tumor histology and location, tissue consistency and texture, patients' age and sex.</p> <p>Results</p> <p>The EMF system could be used effectively during tumor surgery in 83 cases with an essential contribution to the overall success in 14 cases. In the advanced category of effectiveness (very helpful/essential), there was a significant difference between hard and soft tissue consistency (50 of 66 cases vs. 3 of 37 cases). The coagulation function worked well (very helpful/essential) for surface (73 of 103 cases) and spot (46 of 103 cases) coagulation when vessels with a diameter of less than one millimeter were involved. The light-weight bayonet hand piece and long malleable electrodes made the system especially suited for the resection of deep-seated lesions (34 of 52 cases) compared to superficial tumors (19 of 50 cases).</p> <p>The EMF system was less effective than traditional electrosurgical devices in reducing soft glial tumors. Standard methods where also required for coagulation of larger vessels.</p> <p>Conclusion</p> <p>It is possible to identify factors and conditions that predict a beneficial application of high-frequency electromagnetics for tumor vaporization and coagulation. This allows focusing the use of this technology on selective indications.</p

    New Variant of Varicella-Zoster Virus

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    In 1998, a varicella-zoster virus glycoprotein E (gE) mutant virus (VZV-MSP) was isolated from a child with chickenpox. VZV-MSP, representing a second VZV serotype, was considered a rarity. We isolated another VZV-MSP-like virus from an elderly man with herpes zoster. These gE mutant viruses may have arisen through independent mutation or may represent a distinct VZV subpopulation that emerged more than 50 years ago

    Transition from the locked in to the completely locked-in state: A physiological analysis

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    h i g h l i g h t s This represents the first documentation of transition of a patient with ALS from the Locked In State the to Completely Locked In State, and the first EMG documentation of loss of all muscle activities, including sphincter function, but with retained cognition as measured with ERPs. In this patient, any stimulation, communication or learning using visual and tactile stimuli was lost. Visual BCI was useless. The findings suggest ALS as a multisystem disorder, even affecting afferent sensory pathways. a b s t r a c t Objective: To clarify the physiological and behavioral boundaries between locked-in (LIS) and the completely locked-in state (CLIS) (no voluntary eye movements, no communication possible) through electrophysiological data and to secure brain-computer-interface (BCI) communication. Methods: Electromyography from facial muscles, external anal sphincter (EAS), electrooculography and electrocorticographic data during different psychophysiological tests were acquired to define electrophysiological differences in an amyotrophic lateral sclerosis (ALS) patient with an intracranially implanted grid of 112 electrodes for nine months while the patient passed from the LIS to the CLIS. Results: At the very end of the LIS there was no facial muscle activity, nor external anal sphincter but eye control. Eye movements were slow and lasted for short periods only. During CLIS event related brain potentials (ERP) to passive limb movements and auditory stimuli were recorded, vibrotactile stimulation of different body parts resulted in no ERP response. Conclusions: The results presented contradict the commonly accepted assumption that the EAS is the last remaining muscle under voluntary control and demonstrate complete loss of eye movements in CLIS. The eye muscle was shown to be the last muscle group under voluntary control. The findings suggest ALS as a multisystem disorder, even affecting afferent sensory pathways. Significance: Auditory and proprioceptive brain-computer-interface (BCI) systems are the only remaining communication channels in CLIS

    A review of high impact weather for aviation meteorology

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    This review paper summarizes current knowledge available for aviation operations related to meteorology and provides suggestions for necessary improvements in the measurement and prediction of weather-related parameters, new physical methods for numerical weather predictions (NWP), and next-generation integrated systems. Severe weather can disrupt aviation operations on the ground or in-flight. The most important parameters related to aviation meteorology are wind and turbulence, fog visibility, aerosol/ash loading, ceiling, rain and snow amount and rates, icing, ice microphysical parameters, convection and precipitation intensity, microbursts, hail, and lightning. Measurements of these parameters are functions of sensor response times and measurement thresholds in extreme weather conditions. In addition to these, airport environments can also play an important role leading to intensification of extreme weather conditions or high impact weather events, e.g., anthropogenic ice fog. To observe meteorological parameters, new remote sensing platforms, namely wind LIDAR, sodars, radars, and geostationary satellites, and in situ instruments at the surface and in the atmosphere, as well as aircraft and Unmanned Aerial Vehicles mounted sensors, are becoming more common. At smaller time and space scales (e.g., < 1 km), meteorological forecasts from NWP models need to be continuously improved for accurate physical parameterizations. Aviation weather forecasts also need to be developed to provide detailed information that represents both deterministic and statistical approaches. In this review, we present available resources and issues for aviation meteorology and evaluate them for required improvements related to measurements, nowcasting, forecasting, and climate change, and emphasize future challenges

    Long-term treatment with lanthanum carbonate reduces mineral and bone abnormalities in rats with chronic renal failure

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    Background. Lanthanum carbonate (FOSRENOL®, Shire Pharmaceuticals) is an effective non-calcium, non-resin phosphate binder for the treatment of hyperphosphataemia in patients with chronic kidney disease (CKD). In this study, we used a rat model of chronic renal failure (CRF) to examine the long-term effects of controlling serum phosphorus with lanthanum carbonate treatment on the biochemical and bone abnormalities associated with CKD–mineral and bone disorder (CKD–MBD)

    Perisylvian white matter connectivity in the human right hemisphere

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    Background By using diffusion tensor magnetic resonance imaging (DTI) and subsequent tractography, a perisylvian language network in the human left hemisphere recently has been identified connecting Brocas's and Wernicke's areas directly (arcuate fasciculus) and indirectly by a pathway through the inferior parietal cortex. Results Applying DTI tractography in the present study, we found a similar three-way pathway in the right hemisphere of 12 healthy individuals: a direct connection between the superior temporal and lateral frontal cortex running in parallel with an indirect connection. The latter composed of a posterior segment connecting the superior temporal with the inferior parietal cortex and an anterior segment running from the inferior parietal to the lateral frontal cortex. Conclusion The present DTI findings suggest that the perisylvian inferior parietal, superior temporal, and lateral frontal corticies are tightly connected not only in the human left but also in the human right hemisphere
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