248 research outputs found
Development of an Experimental EEG Paradigm to Investigate Dysfunctions in Schizophrenia: Predicting the Sensory Consequences of Oneâs Own Actions
Background:
Prediction mechanisms are crucial for efficient perception of the environment and ourselves as well as for discrimination between self-generated and external changed situations. Known as the internal forward model, an efference copy of the motor plan prepares the sensory areas for the reafferent feedback of oneâs own planned actions. In case of a match between predicted and actual sensory feedback, further processing of the sensory consequences can be damped. This can be seen in suppressed N1-ERP amplitudes in EEG as well as attenuated intensity perception in behavioural data. Moreover, agency for self-generated actions can be attributed correctly by means of this mechanism, whereas external actions cannot prepare the sensory cortex with efference copy and therefore are identified as externally-generated. Dysfunctions in the prediction mechanism for self-generated actions result in a mismatch in the internal forward model, which in turn results in external attribution of agency as well as abnormal neurophysiological and behavioural correlates. Disturbed prediction mechanisms and failure in efference copy are suggested to be a reason for several positive symptoms of schizophrenia like sensory hallucinations and passivity experiences.
Hypotheses/Objective:
In the first part of our study, we investigated efference copy based predictions in healthy subjects in an extensive button press experiment. We hypothesised that the analyses of a selected number of visual trials with the same intensity will be sufficient to show N1-ERP suppression in active conditions. We expected that the second stimulus is perceived as more intense significantly more often in active conditions. With the main aim to develop an optimised and suitable experiment for patients, we hypothesised clearer N1-ERP and behavioural effects after changing the experimental setup in the second part of our study by altering the time intervals, shortening the overall duration, changing the presentation format and focussing on the visual condition only. Finally, we suggested that participants are able to perform the optimised task well. We expected this to be evidenced by the Post-Experiment Questionnaire.
Material and Methods:
Participants pressed actively or passively a button followed by visual stimuli displayed on a computer monitor. Consequently, they judged whether the first or second stimulus was brighter by pressing one of the defined keys. For the total duration of the experiments, we recorded EEG. Additionally, participants were asked to complete a questionnaire about the optimised experiment to assess the performance and suitability.
Results:
For both experiments, we found significantly smaller N1 peak values in active trials than in passive conditions in healthy subjects. The difference between the two experiments themselves was not significant. Behavioural data for intensity perception showed no significant difference, neither in the individual experiments nor in comparing the two. In patients with schizophrenia, we found no significant results for the optimised experiment. However, patients as well as healthy subjects were able to perform well in the optimised experiment assessed by the Post-Experiment Questionnaire.
Discussion:
Our electrophysiological results go in line with prior research in healthy subjects in both experiments. We showed that the analyses of a selected number of visual trials with the same intensity was sufficient to show N1-ERP suppression in active conditions in the extensive experiment. In contrast to our expectations for the behavioural task, we did not find a significant difference between the two conditions for both experiments. This stands in contrast to the underÂŹstanding of sensory attenuation that self-initiated actions perceived as less intense than external ones. Therefore, further changes and studies are needed to show more robust effects for the visual system whereas most of the former studies focus on the other sensory modalities. However, the development of an EEG study which is suitable for patients with schizophrenia was successful regarding the Post-Experiment Questionnaire data.
Conclusion:
In conclusion, we demonstrated evidence of the neural (but not behavioural) mechanism in the visual modality. With the main aim to develop an experimental paradigm for patients to investigate dysfunctions in schizophrenia, we showed the suitability of the task assessed by the Post-Experiment Questionnaire. Further studies with a larger sample of patients are required to give more insight into the psychopathology and impaired predictive mechanisms in the visual domain in schizophrenia
Zur Wirkung von Cyclophilin A bei der Thrombozyten-Endothel Interaktion und bei ischÀmischen Kardiomyozyten
Comprehensive study on gluten composition and baking quality of winter wheat
Background and Objectives
Protein and gluten content and composition are important for the baking quality of wheat flours. Our aim was to provide a comprehensive characterization of 82 wheat flours to analyze the influence of protein composition on rheological and baking quality parameters.
Findings
Protein composition, starch gelatinization behavior, as well as rheological (microfarinograph, gluten aggregation, extensibility), and baking parameters were determined. The correlation matrix showed no significant correlations between gluten composition and loaf volume. Parameters of the gluten aggregation test allowed a prediction of gluten, gliadin, and glutenin content with an absolute root mean square error of cross validation of 7.5, 6.0, and 3.2âmg/g, respectively, using partial least squares regression. Starch gelatinization temperature had an effect on gluten aggregation.
Conclusions
The gluten aggregation test was suitable to predict gluten, gliadin, and glutenin content. The lack of correlations between protein composition and loaf volume indicates that baking quality is the result of a complex combination of different parameters.
Significance and Novelty
Our study is the first to comprehensively analyze 82 wheat flours, especially in terms of gluten composition. We show that flour blends can reach excellent baking quality even if quality indicators like crude protein or extensibility are comparatively low
Effekte von plĂ€ttchenreichem Plasma auf SchlĂŒsselzellen der kutanen Wundheilung nach externer Bestrahlung
Die Grundlage der physiologischen Wundheilung bildet ein koordiniertes Ineinandergreifen fein aufeinander abgestimmter Mechanismen, in denen Wachstumsfaktoren eine relevante Rolle spielen. Die Anwendung ionisierender Strahlung, die bei Malignomen im Kopf-Hals-Bereich zum primĂ€ren und adjuvanten Therapieregime zĂ€hlt, gehört zu den Faktoren, die dieses sensible Gleichgewicht empfindlich stören. Als Therapiemöglichkeit fĂŒr strahleninduzierte Wundheilungsstörungen wird u.a. die exogene Stammzelltherapie untersucht. Desweiteren gilt plĂ€ttchenreiches Plasma als potentes, autologes, pro-proliferatives Blutderivat. Dabei handelt es sich um ein autologes Blutplasma mit der 4-5-fachen Konzentration von Thrombozyten pro ÎŒl im Vergleich zu Vollblut. Die darin enthaltenen Wachstumsfaktoren könnten die lokale VerfĂŒgbarkeit von wundheilungsfördernden Mediatoren erhöhen und dadurch radiogenen Wundheilungsstörungen entgegenwirken. Um diese Hypothese auf zellulĂ€rer Ebene zu untersuchen, erarbeitete unsere Arbeitsgruppe zwei Modelle. Im ersten Modell wurden humane adipogene Stammzellen (hASC) und humane dermale mirkovaskulĂ€re Endothelzellen (HDMEC) in Mono- und Ko-Kultur mit 2 Gray (Gy), 6 Gy oder 12 Gy bestrahlt oder blieben als Positivkontrolle unbestrahlt. Im Vergleich dazu wurde einem Teil der Zellkulturen 5% PRP oder 10% PRP zugesetzt. Gemessen wurden VerĂ€nderungen bezĂŒglich der Zellzahlen und der Freisetzung von Wachstumsfaktoren (basic Fibroblast Growth Factor (bFGF), Vascular Endothelial Growth Factor (VEGF), Platelet-derived Growth Factor (PDGF)), Zytokinen (Interleukin (IL)-6) und AdhĂ€sionsmolekĂŒlen (soluble Intercellular Adhesion Molecule (sICAM) -1 und soluble Vascular Cellular Adhesion Molecule (sVCAM) -1), durch Applikation ansteigender Stahlendosen oder in Verbindung mit unterschiedlicher Konzentration des PRP. Die Konzentrationen der erwĂ€hnten EntzĂŒndungsmediatoren und Wachstumsfaktoren wurde in den ZellĂŒberstĂ€nden mittels ELISA bestimmt. FĂŒr das zweite Modell wurden pulmonale Fibroblasten mit HDMEC in einem Tube Formation Assay mit und ohne Zugabe von 5% PRP ko-kultiviert und zweimal mit jeweils 2 Gy bestrahlt und nach 7 Tagen der Effekt auf die GefĂ€Ăneubildung untersucht.
Als Ergebnis der Exposition mit ionisierender Strahlung, sank im ersten Modell die Zellzahl der HDMEC in Mono- und Ko-Kultur ab einer Strahlendosis von 6 Gy signifikant im Vergleich zur unbestrahlten Kontrolle ab. Bei hASC in Monokultur blieb
ein Strahleneffekt aus. Die Zugabe von 5% und 10% PRP zu hASC in Monokultur hingegen fĂŒhrte bei unbestrahlten und mit 2 Gy bestrahlten Kulturen zur Zellproliferation. Am deutlichsten konnte der pro-proliferative PRP-Effekt in der Ko-Kultur aus HDMEC und hASC gemessen werden. Hier zeigte sich eine signifikante Erhöhung der Zellzahl in unbestrahlten wie auch allen bestrahlten AnsĂ€tzen. In der unbestrahlten Kontrolle verdoppelte sich die Zellzahl der Ko-Kultur nach Zugabe des PRP nahezu, wĂ€hrend nach Bestrahlung mit 6 Gy und 12 Gy eine Addition von 10% PRP die Zellzahl zurĂŒck bis auf das Ausgangsniveau der unbestrahlten Kontrolle brachte. BezĂŒglich der Proteinexpression zeigten HDMEC in Monokultur nach Bestrahlung zum Teil eine signifikante strahlendosisabhĂ€ngige Steigerung der Konzentration von IL-6, PDGF, sICAM-1 und sVCAM-1. Die Zugabe von PRP verstĂ€rkte diesen Effekt bei der Expression von IL-6 und sICAM-1, wĂ€hrend die Konzentration von PDGF durch Addition von PRP konzentrationsabhĂ€ngig signifikant abfiel. In der Ko-Kultur konnte nach Bestrahlung eine dosisabhĂ€ngige Steigerung der Konzentration von bFGF nachgewiesen werden. PRP steigerte diesen Effekt in der Ko-Kultur in bestrahlten Kulturen weiter, wohingegen es bei hASC und HDMEC in Monokultur die Freisetzung von bFGF inhibierte. Die Monokultur von hASC reagierte auf ionisierende Strahlung mit einer Reduktion von IL-6 sowie mit einer tendenziellen Steigerung der VEGF-Konzentration. PRP verstĂ€rkte die Proteinfreisetzung von VEGF in der hASC-Monokultur noch. Im zweiten Modell ergab die Auswertung der Tube Formation Assays mittels Mikroskop und AngioquantÂź Software anti-angiogene Effekte durch wiederholte Bestrahlung.
Bislang existieren wenige Therapien fĂŒr radiogene Wundheilungsstörungen. Die daraus resultierende MorbiditĂ€t stellt jedoch ein klinisch relevantes Problem dar. Die topische Anwendung von plĂ€ttchenreichem Plasma greift durch die Erhöhung lokaler Wachstumsfaktoren, AdhĂ€sionsmolekĂŒle und Zytokine in die Proliferation und Proteinexpression der SchlĂŒsselzellen der Wundheilung sowie in die Ausbildung neuer GefĂ€Ăe ein. Insbesondere in Verbindung mit einer Ko-Kultur aus adipogenen Stammzellen und HDMEC können pro-proliferative Effekte des PRP nachgewiesen werden, die dem strahleninduzierten Zelluntergang effektiv entgegenwirken. Die Stimulation der Proteinexpression des Wachstumsfaktors bFGF durch PRP könnte hauptsĂ€chlich dazu beitragen. Mögliche negative Effekte des PRP, wie die Erhöhung von AdhĂ€sionsmolekĂŒlen, könnten durch die gleichzeitige PrĂ€senz von hASC abgeschwĂ€cht werden. Die Anwendung von PRP zusammen mit adipogenen Stammzellen könnte daher ein wirkungsvolles Instrument in der Therapie strahleninduzierter Wundheilungsstörungen darstellen
A behavioural syndrome, but less evidence for a relationship with cognitive traits in a spatial orientation context
Final LMMs with significant confounding factors on personality and cognitive traits in harvest mice. Table S2. Between-individual correlations among personality and cognitive traits (spatial recognition and spatial learning performance) in harvest mice, calculated from a multivariate mixed model. Table S3. Within-individual correlations between personality and cognitive traits (spatial recognition and spatial learning performance) in harvest mice, calculated from a multivariate mixed model. Table S4. Test for a cognitive syndrome caused by a speed-accuracy trade-off in harvest mice: Between-individual correlations among personality traits and decision styles (decision speed and accuracy) calculated from a multivariate mixed model. Table S5. Test for a cognitive syndrome caused by a speed-accuracy trade-off in harvest mice: Within-individual correlations between personality traits and decision styles (decision speed and accuracy) calculated from a multivariate mixed model. (PDF 324ĂÂ kb
The Northern Calcareous Alps revisited: Formation of a hyperextended margin and mantle exhumation in the Northern Calcareous Alps sector of the Neo-Tethys (Eastern Alps, Austria)
The Neo-Tethys margin evolution is preserved in the Northern Calcareous Alps (Eastern Alps), from Late Permian crustal stretching to Late Triassic oceanization. The Northern Calcareous Alps represent the salt-floored fold-and-thrust belt developed from the salt-influenced Triassic carbonate sedimentary cover of the ancestral European margin of the Neo-Tethys Ocean. A crustal scale model for the margin has been obtained by restoration of regional cross-sections of the Northern Calcareous Alps carbonate platforms. Lithospheric break-up was investigated from remnants of exhumed mantle found within an evaporitic melange, suggesting hyperextended crust underneath the distal Triassic platforms of the Northern Calcareous Alps preceding breakup. By modelling the thermal evolution of the margin in combination with excellent stratigraphic control, a detailed timeline has been established for the evolution of the Neo-Tethys margin, especially around the period of rapid mantle exhumation. Our study indicates that salt-floored carbonate shelfs can be used as a proxy to characterize the margins evolution, from crustal stretching to continental breakup. Diagnostic stratigraphic records are preserved in the carbonate platforms: pre- mantle exhumation carbonates are represented by aggrading isolated carbonate platforms first, followed by expanding and margin wide prograding carbonate shelfs once thermal subsidence dominates. In addition, a distinct clastic sequence is deposited as an immediate response to mantle exhumation, in between the pre- and post-mantle exhumation carbonate factory. Our study proposes a new refined model for the formation of the Neo-Tethys margin and provides new insights for the dynamic coupling of salt-controlled carbonate shelfs and the underlying lithosphere during continental breakup
Enabling Innovation in Engineering Education by providing Flexible Funds for teaching Staff
This study evaluated the influence of addition of 10% calcium chloride (CaCl(2)) on the setting time, solubility, disintegration, and pH of white MTA (WMTA) and white Portland cement (WPC). A test of the setting time was performed following the #57 ADA specifications and a test of the final setting time according to the ASTM. For the solubility tests disintegration and pH, Teflon rings were filled with the cements and weighed after setting. After 24 h in a desiccator, they were once again weighed. Thereafter, they were immersed in MiliQ water for 24 and 72 h and 7, 14, and 28 days, with maintenance in the desiccator and weighing between periods. The pH of water in which the rings were immersed was measured immediately after contact with them and in the other periods. The addition of CaCl(2) provided a significant reduction (50%) in the initial setting time of cements. The final setting time of WMTA was reduced in 35.5% and the final setting time of WPC in 68.5%. The WMTA with CaCl(2) absorbed water and gained weight with time, except for in the 24-h period. The addition of CaCl(2) to the WPC reduced its solubility. The addition of CaCl(2) increased the pH of WMTA in the immediate period and at 24 and 72 h and for WPC in the immediate period and at 24 h. The addition of CaCl(2) to WMTA and WPC reduced the setting times and solubility of both and increased the pH of cements in the initial periods. (J Endod 2009;35:550-554
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