21 research outputs found

    Keratinocytes as Depository of Ammonium-Inducible Glutamine Synthetase: Age- and Anatomy-Dependent Distribution in Human and Rat Skin

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    In inner organs, glutamine contributes to proliferation, detoxification and establishment of a mechanical barrier, i.e., functions essential for skin, as well. However, the age-dependent and regional peculiarities of distribution of glutamine synthetase (GS), an enzyme responsible for generation of glutamine, and factors regulating its enzymatic activity in mammalian skin remain undisclosed. To explore this, GS localization was investigated using immunohistochemistry and double-labeling of young and adult human and rat skin sections as well as skin cells in culture. In human and rat skin GS was almost completely co-localized with astrocyte-specific proteins (e.g. GFAP). While GS staining was pronounced in all layers of the epidermis of young human skin, staining was reduced and more differentiated among different layers with age. In stratum basale and in stratum spinosum GS was co-localized with the adherens junction component ß-catenin. Inhibition of, glycogen synthase kinase 3β in cultured keratinocytes and HaCaT cells, however, did not support a direct role of ß-catenin in regulation of GS. Enzymatic and reverse transcriptase polymerase chain reaction studies revealed an unusual mode of regulation of this enzyme in keratinocytes, i.e., GS activity, but not expression, was enhanced about 8–10 fold when the cells were exposed to ammonium ions. Prominent posttranscriptional up-regulation of GS activity in keratinocytes by ammonium ions in conjunction with widespread distribution of GS immunoreactivity throughout the epidermis allows considering the skin as a large reservoir of latent GS. Such a depository of glutamine-generating enzyme seems essential for continuous renewal of epidermal permeability barrier and during pathological processes accompanied by hyperammonemia

    Brain Painting: First Evaluation of a New Brain–Computer Interface Application with ALS-Patients and Healthy Volunteers

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    Brain–computer interfaces (BCIs) enable paralyzed patients to communicate; however, up to date, no creative expression was possible. The current study investigated the accuracy and user-friendliness of P300-Brain Painting, a new BCI application developed to paint pictures using brain activity only. Two different versions of the P300-Brain Painting application were tested: A colored matrix tested by a group of ALS-patients (n = 3) and healthy participants (n = 10), and a black and white matrix tested by healthy participants (n = 10). The three ALS-patients achieved high accuracies; two of them reaching above 89% accuracy. In healthy subjects, a comparison between the P300-Brain Painting application (colored matrix) and the P300-Spelling application revealed significantly lower accuracy and P300 amplitudes for the P300-Brain Painting application. This drop in accuracy and P300 amplitudes was not found when comparing the P300-Spelling application to an adapted, black and white matrix of the P300-Brain Painting application. By employing a black and white matrix, the accuracy of the P300-Brain Painting application was significantly enhanced and reached the accuracy of the P300-Spelling application. ALS-patients greatly enjoyed P300-Brain Painting and were able to use the application with the same accuracy as healthy subjects. P300-Brain Painting enables paralyzed patients to express themselves creatively and to participate in the prolific society through exhibitions

    Comparison de la Qualité des Open Data portails utilisant AHP

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    During recent years, more and more Open Data becomes available and used as part of the Open Data movement. However, there are reported issues with the quality of the metadata in data portals and the data itself. This is a seri- ous risk that could disrupt the Open Data project, as well as e-government initiatives since the data quality needs to be managed to guarantee the reliability of e-government to the public. First quality assessment frameworks emerge to eval- uate the quality for a given dataset or portal along various dimensions (e.g., information completeness). Nonetheless, a common problem with such frameworks is to provide mean- ingful ranking mechanisms that are able to integrate sev- eral quality dimensions and user preferences (e.g., a portal provider is likely to have different quality preferences than a portal consumer). To address this multi-criteria decision making problem, our research work applies AHP (Analytic Hierarchy Process), which compares 146 active Open Data portals across 44 countries, powered by the CKAN software

    Individual Differences Fill the Uncharted Intersections Between Cognitive Structure, Flexibility, and Plasticity in Multitasking

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    Broeker L, Bruning J, Fandakova Y, et al. Individual Differences Fill the Uncharted Intersections Between Cognitive Structure, Flexibility, and Plasticity in Multitasking. Psychological Review. 2022.It has been recently suggested that research on human multitasking is best organized according to three research perspectives, which differ in their focus on cognitive structure, flexibility, and plasticity. Even though it is argued that the perspectives should be seen as complementary, there has not been a formal approach describing or explaining the intersections between the three perspectives. With this theoretical note, we would like to show that the explicit consideration of individual differences is one possible way to elaborate in more detail on how and why the perspectives complement each other. We will define structure, flexibility, and plasticity; describe what constitutes individual differences; will outline selected empirical examples; and raise possible future research questions helping to develop the research field

    Out of the frying pan into the fire-the P300-based BCI faces real-world challenges

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    Brain-computer interfaces (BCIs) have been investigated for more than 20 years. Many BCIs use noninvasive electroencephalography as a measurement technique and the P300 event-related potential as an input signal (P300 BCI). Since the first experiment with a P300 BCI system in 1988 by Farwell and Donchin, not only data processing has improved but also stimuli presentation has been varied and a plethora of applications was developed and refined. Nowadays, these applications are facing the challenge of being transferred from the research laboratory into real-life situations to serve motor-impaired people in their homes as assistive technology. © 2011 Elsevier B.V

    A brain-computer interface as input channel for a standard assistive technology software

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    Recently brain-computer interface (BCI) control was integrated into the commercial assistive technology product QualiWORLD (QualiLife Inc., Paradiso-Lugano, CH). Usability of the first prototype was evaluated in terms of effectiveness (accuracy), efficiency (information transfer rate and subjective workload/NASA Task Load Index) and user satisfaction (Quebec User Evaluation of Satisfaction with assistive Technology, QUEST 2.0) by four end-users with severe disabilities. Three assistive technology experts evaluated the device from a third person perspective. The results revealed high performance levels in communication and internet tasks. Users and assistive technology experts were quite satisfied with the device. However, none could imagine using the device in daily life without improvements. Main obstacles were the EEG-cap and low speed

    Probing command following in patients with disorders of consciousness using a brain-computer interface.

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    peer reviewedOBJECTIVE: To determine if brain-computer interfaces (BCIs) could serve as supportive tools for detecting consciousness in patients with disorders of consciousness by detecting response to command and communication. METHODS: We tested a 4-choice auditory oddball EEG-BCI paradigm on 16 healthy subjects and 18 patients in a vegetative state/unresponsive wakefulness syndrome, in a minimally conscious state (MCS), and in locked-in syndrome (LIS). Subjects were exposed to 4 training trials and 10 -12 questions. RESULTS: Thirteen healthy subjects and one LIS patient were able to communicate using the BCI. Four of those did not present with a P3. One MCS patient showed command following with the BCI while no behavioral response could be detected at bedside. All other patients did not show any response to command and could not communicate with the BCI. CONCLUSION: The present study provides evidence that EEG based BCI can detect command following in patients with altered states of consciousness and functional communication in patients with locked-in syndrome. However, BCI approaches have to be simplified to increase sensitivity. SIGNIFICANCE: For some patients without any clinical sign of consciousness, a BCI might bear the potential to employ a "yes-no" spelling device offering the hope of functional interactive communication
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