921 research outputs found

    Early Modern Self-narratives from German-speaking Areas in a Transcultural Perspective

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    Autobiographical texts have long been seen, from a micro-level perspective, as evidence of the ‘individuality’ of the writer, and, from a macro-level perspective, as evidence of the long-term historical development of European or Western individual-oriented society. However, recent research has undertaken to deconstruct this notion, suggesting that ‘Western’ texts are as deeply embedded in a social world and in social-oriented perspectives as those from other world regions. The individualised person is now recognised as just one among many concepts of the person. This article summarises the research that has been conducted during the past two decades on early modern autobiographical writings, primarily from German-speaking areas of the world. It closely examines the interplay between individual and society in one particular autobiography, that of the Zurich professor of Old Testament Studies Konrad Pellikan (1478–1556). Using the concept of the ‘autobiographical person’, it shows his work to be typical of the autobiographies written by one social group—early modern scholars. By comparing this Christian male scholar with his Jewish and Muslim colleagues, the article aims to attain a transcultural, gendered perspective on autobiography. In an attempt to reach some methodological and theoretical conclusions, a set of analytical tools is proposed to distinguish between the perspectives of authors and of later scholars, and also between (a) real persons and their personhood, (b) ‘autobiographical persons’ and (c) cultural concepts of ‘person’. In this way, the ‘person’ is taken into account by scholars as an analytical category, as well as being a set of real-life practices and conceptual notions used by actors in various social, cultural and historical settings

    The relationship between corpus callosum size and forebrain volume

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    Using high-resolution in vivo magnetic resonance morphometry we measured forebrain volume (FBV), midsagittal size of the corpus callosum (CC) and four CC subareas in 120 young and healthy adults (49 women, 71 men). We found moderate linear and quadratic correlations, indicating that the CC and all CC subareas increase with FBV both in men and women (multiple r2 ranging from 0.10 to 0.28). Allometric equations revealed that these increases were less than proportional to FBV (r2 ranging from 0.02 to 0.30). Absolute CC measurements, as well as CC subareas relative to total CC or FBV (the latter measures termed the CC ratios), were further analyzed with regard to possible effects of handedness, gender, or handedness by gender interaction. Contrary to previous reports, left-handers did not show larger CC measurements compared to right-handers. The only apparent influence of gender was on the CC ratios, which were larger in women. However, smaller brains had larger CC ratios which were mainly independent of gender, a result of the less than proportional increase of callosal size with FBV. We suggest that the previously described gender differences in CC anatomy may be better explained by an underlying effect of brain size, with larger brains having relatively smaller callosa. This lends empirical support to the hypothesis that brain size may be an important factor influencing interhemispheric connectivity and lateralizatio

    Bridging the gap: a model of common neural mechanisms underlying the Fröhlich effect, the flash-lag effect, and the representational momentum effect

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    In recent years, the study and interpretation of mislocalization phenomena observed with moving objects have caused an intense debate about the processing mechanisms underlying the encoding of position. We use a neurophysiologically plausible recurrent network model to explain visual illusions that occur at the start, midposition, and end of motion trajectories known as the Fröhlich, the flash-lag, and the representational momentum effect, respectively. The model implements the idea that trajectories are internally represented by a traveling activity wave in position space, which is essentially shaped by local feedback loops within pools of neurons. We first use experimentally observed trajectory representations in the primary visual cortex of cat to adjust the spatial ranges of lateral interactions in the model.We then show that the readout of the activity profile at adequate points in time during the build-up, midphase, and decay of the wave qualitatively and quantitatively explain the known dependence of the mislocalization errors on stimulus attributes such as contrast and speed. We conclude that cooperative mechanisms within the network may be responsible for the three illusions, with a possible intervention of top-down influences that modulate the efficacy of the lateral interactions.Deutscher Akademischer Austauschdienst (DAAD) / Conselho de Reitores das Universidades Portuguesas (CRUP) - As AcçÔes Integradas Luso - AlemĂŁsBundesministerium fĂŒr Bildung und Forschungthe (BMBF

    Neuronal Modifications During Visuomotor Association Learning Assessed by Electric Brain Tomography

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    Summary: In everyday life specific situations need specific reactions. Through repetitive practice, such stimulus-response associations can be learned and performed automatically. The aim of the present EEG study was the illustration of learning dependent modifications in neuronal pathways during short-term practice of visuomotor associations. Participants performed a visuomotor association task including four visual stimuli, which should be associated with four keys, learned by trial and error. We assumed that distinct cognitive processes might be dominant during early learning e.g., visual perception and decision making. Advanced learning, however, might be indicated by increased neuronal activation in integration- and memory-related regions. For assessment of learning progress, visual- and movement-related brain potentials were measured and compared between three learning stages (early, intermediate, and late). The results have revealed significant differences between the learning stages during distinct time intervals. Related to visual stimulus presentation, Low Resolution Electromagnetic Brain Tomography (LORETA) revealed strong neuronal activation in a parieto-prefrontal network in time intervals between 100-400 ms post event and during early learning. In relation to the motor response neuronal activation was significantly increased during intermediate compared to early learning. Prior to the motor response (120-360 ms pre event), neuronal activation was detected in the cingulate motor area and the right dorsal premotor cortex. Subsequent to the motor response (68-430 ms post event) there was an increase in neuronal activation in visuomotor- and memory-related areas including parietal cortex, SMA, premotor, dorsolateral prefrontal, and parahippocampal cortex. The present study has shown specific time elements of a visuomotor-memory-related network, which might support learning progress during visuomotor association learnin

    Artists' Advance: Decreased Upper Alpha Power while Drawing in Artists Compared with Non-Artists

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    Brain mechanisms associated with artistic talents or skills are still not well understood. This exploratory study investigated differences in brain activity of artists and non-artists while drawing previously presented perspective line-drawings from memory and completing other drawing-related tasks. Electroencephalography (EEG) data were analyzed for power in the frequency domain by means of a Fast Fourier Transform (FFT). Low Resolution Brain Electromagnetic Tomography (LORETA) was applied to localize emerging significances. During drawing and related tasks, decreased power was seen in artists compared to non-artists mainly in upper alpha frequency ranges. Decreased alpha power is often associated with an increase in cognitive functioning and may reflect enhanced semantic memory performance and object recognition processes in artists. These assumptions are supported by the behavioral data assessed in this study and complement previous findings showing increased parietal activations in non-artists compared to artists while drawing. However, due to the exploratory nature of the analysis, additional confirmatory studies will be neede

    Brain stimulation modulates driving behavior

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    BACKGROUND: Driving a car is a complex task requiring coordinated functioning of distributed brain regions. Controlled and safe driving depends on the integrity of the dorsolateral prefrontal cortex (DLPFC), a brain region, which has been shown to mature in late adolescence. METHODS: In this study, driving performance of twenty-four male participants was tested in a high-end driving simulator before and after the application of transcranial direct current stimulation (tDCS) for 15 minutes over the left or right DLPFC. RESULTS: We show that external modulation of both, the left and the right, DLPFC directly influences driving behavior. Excitation of the DLPFC (by applying anodal tDCS) leads to a more careful driving style in virtual scenarios without the participants noticing changes in their behavior. CONCLUSION: This study is one of the first to prove that external stimulation of a specific brain area can influence a multi-part behavior in a very complex and everyday-life situation, therefore breaking new ground for therapy at a neural level

    NMR-spektroskopische Untersuchung der Reaktion von 3-Aminopropyltriethoxysilan mit KieselsÀurelösungen

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    29Si- und 14N-NMR-Untersuchungen der Reaktion von Aminopropyltriethoxysilan (APTS) und KieselsĂ€ure (KS) in sauren wĂ€ĂŸrigen Lösungen (MolverhĂ€ltnis APTS/KS = 1:1, CSiO2 = 0,45 M; pH = 2,3) zeigen, daß durch APTS die Kondensationsreaktionen der KS stark verlangsamt werden. Als Ursachen werden partielle Kondensationsreaktionen des APTS mit der KS und das Vorliegen von NH3+-OSi Bindungen diskutiert. Durch die Dominanz von NH3+ gegenĂŒber NH2-Gruppen bis pH 10,1 liegen auch in neutralen und schwach basischen APTS/KS-Lösungen kondensationsbestĂ€ndige KieselsĂ€uren bzw. Silicatanionen vor. Durch Konzentrieren der APTS/KS-Lösungen sind kieselsĂ€urereiche, wasserlösliche Feststoffe darstellbar

    Virtual Reference for Video Collections: System Infrastructure, User Interface and Pilot User Study

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    A new video-based Virtual Reference (VR) tool called VideoHelp was designed and developed to support video navigation escorting, a function that enables librarians to co-navigate a digital video with patrons in the web-based environment. A client/server infrastructure was adopted for the VideoHelp system and timestamps were used to achieve the video synchronization between the librarians and patrons. A pilot usability study of using VideoHelp prototype in video seeking was conducted and the preliminary results demonstrated that the system is easy to learn and use, and real-time assistance from virtual librarians in video navigation is desirable on a conditional basis

    Modellierung der ZuverlÀssigkeit bei Entwurf und Verifikation von Mixed-Signal-Schaltungen

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    Die zunehmende Verbreitung von Elektronik im Alltag und die weitere Verringerung der StrukturgrĂ¶ĂŸen stellen neue Anforderungen an die ZuverlĂ€ssigkeit und VerfĂŒgbarkeit integrierter Schaltungen. Die Arbeit zeigt ein systematisches Vorgehen zur Modellierung des funktionalen Schaltungsverhaltens und ergĂ€nzt es um neue Verfahren zur BerĂŒcksichtigung zuverlĂ€ssigkeitsrelevanter Schaltungseigenschaften. Etablierte Verfahren aus der Mechanik zur Behandlung der ZuverlĂ€ssigkeit werden auf die Degradationseffekte integrierter Halbleiterbauelemente angewandt. Entsprechende Lebensdauermodelle zu relevanten Degradationsmechanismen sind dargestellt. Ausgehend davon werden allgemeine Maße zur ZuverlĂ€ssigkeitsbewertung von Bauelementen unter Anwendungsbedingungen abgeleitet. Die Diskussion von Methoden zur Analyse der ZuverlĂ€ssigkeit ganzer Schaltungen im Entwurf rundet die Darstellung ab. Die entwickelten Verfahren dienen der UnterstĂŒtzung eines schnellen und fehlerfreien Entwurfs sicherer und zuverlĂ€ssiger Schaltungen. Die Optimierung einer Schaltung hinsichtlich ihres Alterungsverhaltens verdeutlicht diesen Nutzen.The widespread use of electronics in everyday life and its ongoing miniaturization poses new demands in terms of reliability and dependability of integrated circuits. Modeling as a means to support circuit and system design has been used for many years, mainly to represent the functional behavior. This thesis aims at the following objectives: ‱ For known modeling techniques regarding the functional behavior a systematic methodology is developed and structured in an integrated modelling flow. ‱ The developed methodology is extended by modeling non-functional characteristics particularly with regard to reliability. In this work reliability modeling covers primarily degradation effects that occur during normal operation and affect the electrical behavior of integrated devices. As an important precondition for the developed methods to consider electrical degradation, linear damage accumulation is assumed. That is, the sequence in time of the applied stress is not important, the damage accumulates linearly over time. As a result a systematic process to model the functional behavior of analog and mixed signal circuits is presented. It is amended by new methods to include reliability relevant characteristics of the circuit. Established methods from mechanical engineering to describe and analyze reliability are adopted and applied to the degradation effects of integrated semiconductor devices. Respective lifetime models for relevant degradation effects are presented. Starting from a generic model structure general measures are derived to assess reliability of devices exposed to application conditions. In addition methods to analyze reliability of large circuits in the design process are discussed. The developed methods support a fast and correct design of safe and reliable circuits. As an example the optimization of a circuit with respect to its degradation behavior is demonstrated.Die zunehmende Verbreitung von Elektronik im Alltag und die weitere Verringerung der StrukturgrĂ¶ĂŸen stellt neue Anforderungen an die ZuverlĂ€ssigkeit und VerfĂŒgbarkeit integrierter Schaltungen. Modellierung zur UnterstĂŒtzung des Schaltkreis- und Systementwurfs wird seit langer Zeit eingesetzt, bisher hauptsĂ€chlich zur Nachbildung des funktionalen Verhaltens einer Schaltung. Die vorliegende Arbeit verfolgt zwei Ziele: ‱ Zu bekannten Modellierungsverfahren fĂŒr das funktionale Verhalten wird eine Systematik entwickelt und in einen durchgĂ€ngigen Modellierungsablauf abgebildet. ‱ Die Methodik wird um die Modellierung nichtfunktionaler Eigenschaften erweitert, insbesondere werden Verfahren zur BerĂŒcksichtigung der ZuverlĂ€ssigkeit entwickelt. FĂŒr die ZuverlĂ€ssigkeitsmodellierung werden in erster Linie Degradationseffekte betrachtet, die wĂ€hrend des bestimmungsgemĂ€ĂŸen Betriebs entstehen und sich auf das elektrische Verhalten integrierter Bauelemente auswirken. Als eine wesentliche Voraussetzung fĂŒr die entwickelten Verfahren zur BerĂŒcksichtigung der elektrischen Degradation wird lineare Schadensakkumulation angenommen. Dies bedeutet, dass die zeitliche Abfolge des anliegenden Stresses keine Rolle spielt, sondern sich die entstehende SchĂ€digung linear akkumuliert. Das Ergebnis der Arbeit ist eine systematische Vorgehensweise zur Modellierung des funktionalen Verhaltens von analogen und Mixed-Signal-Schaltungen. Diese wird ergĂ€nzt um neue Verfahren zur BerĂŒcksichtigung zuverlĂ€ssigkeitsrelevanter Eigenschaften der Schaltung. Analogien zur Mechanik erlauben es, in diesem Bereich etablierte Vorgehensweisen zur Beschreibung und Analyse der ZuverlĂ€ssigkeit zu ĂŒbernehmen und auf die Degradationseffekte integrierter Halbleiterbauelemente anzuwenden. Entsprechende Lebensdauermodelle zu relevanten Degradationsmechanismen sind dargestellt. Ausgehend von der generellen Struktur solcher Modelle werden allgemeine Maße zur ZuverlĂ€ssigkeitsbewertung von Bauelementen unter Anwendungsbedingungen abgeleitet. Die Diskussion von Methoden zur Analyse der ZuverlĂ€ssigkeit ganzer Schaltungen im Entwurf rundet die Darstellung ab. Die entwickelten Verfahren dienen der UnterstĂŒtzung eines schnellen und fehlerfreien Entwurfs sicherer und zuverlĂ€ssiger Schaltungen. Anhand der Optimierung einer Schaltung auf der Grundlage ihres Alterungsverhaltens wird dieser Nutzen verdeutlicht
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