TY - GEN A1 - Ungelenk, Johannes T1 - Narcissus and Echo BT - A Political Reading of George Eliot's Daniel Deronda N2 - George Eliot’s late novel Daniel Deronda tackles big, fundamental political questions that radiate from the societal circumstances of the novel’s production and reach deep into our present-day life. The novel critically analyses the capitalistic, morally flawed and standard-less English society and narrates the title hero’s proto-Zionist mission to found a Jewish nation that re-establishes history, meaning and ethical values. This study attempts to trace the novel’s two models of society and time by bringing them into resonance with the myth of Narcissus and Echo famously rendered by Ovid. The unloving, self-referential, visual Narcissus is read as the model for the capitalistic world of spectacle and speculation. Echo’s loving, memory-bearing voice forms an important part in the construction of the sublating unity of the Jewish nation-to-come. Guided by this resonance between George Eliot’s novel and Ovid’s myth pieces of critical theory and philosophy are woven into the study’s fabric. The resulting analysis dissects and deconstructs the novel’s fascinating and highly complex patterns of conditions of possibility for the fabrication of the redeeming Jewish nation, the very same conditions that the novel presents as the conditions of possibility for narrating a meaningful story. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 186 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-599966 SN - 1866-8380 IS - 186 ER - TY - GEN A1 - Mardoukhi, Yousof A1 - Jeon, Jae-Hyung A1 - Metzler, Ralf T1 - Geometry controlled anomalous diffusion in random fractal geometries BT - looking beyond the infinite cluster T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - We investigate the ergodic properties of a random walker performing (anomalous) diffusion on a random fractal geometry. Extensive Monte Carlo simulations of the motion of tracer particles on an ensemble of realisations of percolation clusters are performed for a wide range of percolation densities. Single trajectories of the tracer motion are analysed to quantify the time averaged mean squared displacement (MSD) and to compare this with the ensemble averaged MSD of the particle motion. Other complementary physical observables associated with ergodicity are studied, as well. It turns out that the time averaged MSD of individual realisations exhibits non-vanishing fluctuations even in the limit of very long observation times as the percolation density approaches the critical value. This apparent non-ergodic behaviour concurs with the ergodic behaviour on the ensemble averaged level. We demonstrate how the non-vanishing fluctuations in single particle trajectories are analytically expressed in terms of the fractal dimension and the cluster size distribution of the random geometry, thus being of purely geometrical origin. Moreover, we reveal that the convergence scaling law to ergodicity, which is known to be inversely proportional to the observation time T for ergodic diffusion processes, follows a power-law ∼T−h with h < 1 due to the fractal structure of the accessible space. These results provide useful measures for differentiating the subdiffusion on random fractals from an otherwise closely related process, namely, fractional Brownian motion. Implications of our results on the analysis of single particle tracking experiments are provided. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 980 KW - plasma-membrane KW - mechanisms KW - motion KW - nonergodicity KW - models Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474864 SN - 1866-8372 IS - 980 SP - 30134 EP - 30147 ER - TY - GEN A1 - Gebel, Arnd A1 - Lüder, Benjamin A1 - Granacher, Urs T1 - Effects of Increasing Balance Task Difficulty on Postural Sway and Muscle Activity in Healthy Adolescents T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - Evidence-based prescriptions for balance training in youth have recently been established. However, there is currently no standardized means available to assess and quantify balance task difficulty (BTD). Therefore, the objectives of this study were to examine the effects of graded BTD on postural sway, lower limb muscle activity and coactivation in adolescents. Thirteen healthy high-school students aged 16 to 17 volunteered to participate in this cross-sectional study. Testing involved participants to stand on a commercially available balance board with an adjustable pivot that allowed six levels of increasing task difficulty. Postural sway [i.e., total center of pressure (CoP) displacements] and lower limb muscle activity were recorded simultaneously during each trial. Surface electromyography (EMG) was applied in muscles encompassing the ankle (m. tibialis anterior, medial gastrocnemius, peroneus longus) and knee joint (m. vastus medialis, biceps femoris). The coactivation index (CAI) was calculated for ankle and thigh muscles. Repeated measures analyses of variance revealed a significant main effect of BTD with increasing task difficulty for postural sway (p < 0.001; d = 6.36), muscle activity (p < 0.001; 2.19 < d < 4.88), and CAI (p < 0.001; 1.32 < d < 1.41). Multiple regression analyses showed that m. tibialis anterior activity best explained overall CoP displacements with 32.5% explained variance (p < 0.001). The observed increases in postural sway, lower limb muscle activity, and coactivation indicate increasing postural demands while standing on the balance board. Thus, the examined board can be implemented in balance training to progressively increase BTD in healthy adolescents. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 583 KW - balance training KW - balance strategy KW - muscle coactivation KW - youth KW - training intensity Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439211 SN - 1866-8364 IS - 583 ER - TY - GEN A1 - Grafe, Marianne A1 - Batsios, Petros A1 - Meyer, Irene A1 - Lisin, Daria A1 - Baumann, Otto A1 - Goldberg, Martin W. A1 - Gräf, Ralph T1 - Supramolecular Structures of the Dictyostelium Lamin NE81 T2 - Potsprint der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized Dictyostelium NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural level that the Dictyostelium NE81 is also capable of assembling into filaments, just as metazoan lamin filament assemblies. Using field-emission scanning electron microscopy, we show that NE81 expressed in Xenopous oocytes forms filamentous structures with an overall appearance highly reminiscent of Xenopus lamin B2. The in vitro assembly properties of recombinant His-tagged NE81 purified from Dictyostelium extracts are very similar to those of metazoan lamins. Super-resolution stimulated emission depletion (STED) and expansion microscopy (ExM), as well as transmission electron microscopy of negatively stained purified NE81, demonstrated its capability of forming filamentous structures under low-ionic-strength conditions. These results recommend Dictyostelium as a non-mammalian model organism with a well-characterized nuclear envelope involving all relevant protein components known in animal cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 682 KW - lamin KW - NE81 KW - Dictyostelium KW - nuclear envelope KW - nuclear lamina KW - expansion microscopy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425976 SN - 1866-8372 IS - 682 ER - TY - GEN A1 - Tremblay, Jean Christophe A1 - Blanco-Rey, Maria T1 - Manipulating interfacial hydrogens at palladium via STM N2 - In this contribution, we provide a detailed dynamical analysis of the interfacial hydrogen migration mediated by scanning tunneling microscopy (STM). Contributions from the STM-current and from the non-adiabatic couplings are taken into account using only first principle models. The slight asymmetry of the tunnelling rates with respect to the potential bias sign inferred from experimental observations is reproduced by weighting the contributions of the metal acceptor–donor states for the propagation of the impinging electrons. The quasi-thermal inelastic collision mechanism is treated perturbatively. The influence of hydrogen pre-coverage is also investigated using new potential energy surfaces obtained from periodic density functional theory calculations. Fully quantum dynamical simulations of the system evolution are performed by solving the Pauli master equation, providing insight into the reaction mechanism of STM manipulation of subsurface hydrogens. It is observed that the hydrogen impurity favors resurfacing over occupation of the bulk and subsurface sites whenever possible. The present simulations give strong indication that the experimentally observed protuberances after STM-excitation are due to hydrogen accumulating in the vicinity of the surface. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 291 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-99511 ER - TY - GEN A1 - Thieken, Annegret A1 - Bessel, Tina A1 - Kienzler, Sarah A1 - Kreibich, Heidi A1 - Müller, Meike A1 - Pisi, Sebastian A1 - Schröter, Kai T1 - The flood of June 2013 in Germany BT - how much do we know about its impacts? T2 - National Hazards Earth System Science N2 - In June 2013, widespread flooding and consequent damage and losses occurred in Central Europe, especially in Germany. This paper explores what data are available to investigate the adverse impacts of the event, what kind of information can be retrieved from these data and how well data and information fulfil requirements that were recently proposed for disaster reporting on the European and international levels. In accordance with the European Floods Directive (2007/60/EC), impacts on human health, economic activities (and assets), cultural heritage and the environment are described on the national and sub-national scale. Information from governmental reports is complemented by communications on traffic disruptions and surveys of flood-affected residents and companies. Overall, the impacts of the flood event in 2013 were manifold. The study reveals that flood-affected residents suffered from a large range of impacts, among which mental health and supply problems were perceived more seriously than financial losses. The most frequent damage type among affected companies was business interruption. This demonstrates that the current scientific focus on direct (financial) damage is insufficient to describe the overall impacts and severity of flood events. The case further demonstrates that procedures and standards for impact data collection in Germany are widely missing. Present impact data in Germany are fragmentary, heterogeneous, incomplete and difficult to access. In order to fulfil, for example, the monitoring and reporting requirements of the Sendai Framework for Disaster Risk Reduction 2015–2030 that was adopted in March 2015 in Sendai, Japan, more efforts on impact data collection are needed. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-97207 ER - TY - GEN A1 - Priewe, Marc T1 - Walter W. Woodward, Prospero´s America: John Winthrop, Jr., Alchemy, and the Creation of New England Culture, 1606-1676 / [rezensiert von] Marc Priewe N2 - Rezensiertes Werk: Walter W. Woodward: Prospero’s America: John Winthrop, Jr., Alchemy, and the Creation of New England Culture, 1606-1676. Chapel Hill: University of North Carolina Press, 2010. Hb. 336pp. ISBN 978-0-8078-3301-8. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 104 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-93713 SP - 199 EP - 200 ER - TY - GEN A1 - Mkandawire, Thandika T1 - The death of Mandela and Africa’s liberation struggle N2 - The name Mandela became first inscribed in the annals of African liberation as nothing particularly unusual at the time. The late fifties was an era of trials and detentions in the colonies. The Treason Trial, which took place from 1956 to 1961, was closely followed by those of my generation largely through Drum Magazine. KW - Africa KW - South Afrika KW - Nelson Mandela KW - Apartheid Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-69964 ER - TY - GEN A1 - Lindenmaier, Falk A1 - Zehe, Erwin A1 - Dittfurth, Angela A1 - Ihringer, Jürgen T1 - Process identification at a slow-moving landslide in the Vorarlberg Alps N2 - A fine-grained slope that exhibits slow movement rates was investigated to understand how geohydrological processes contribute to a consecutive development of mass movements in the Vorarlberg Alps, Austria. For that purpose intensive hydrometeorological, hydrogeological and geotechnical observations as well as surveying of surface movement rates were conducted during 1998–2001. Subsurface water dynamics at the creeping slope turned out to be dominated by a three-dimensional pressure system. The pressure reaction is triggered by fast infiltration of surface water and subsequent lateral water flow in the south-western part of the hillslope. The related pressure signal was shown to propagate further downhill, causing fast reactions of the piezometric head at 5Ð5 m depth on a daily time scale. The observed pressure reactions might belong to a temporary hillslope water body that extends further downhill. The related buoyancy forces could be one of the driving forces for the mass movement. A physically based hydrological model was adopted to model simultaneously surface and subsurface water dynamics including evapotranspiration and runoff production. It was possible to reproduce surface runoff and observed pressure reactions in principle. However, as soil hydraulic functions were only estimated on pedotransfer functions, a quantitative comparison between observed and simulated subsurface dynamics is not feasible. Nevertheless, the results suggest that it is possible to reconstruct important spatial structures based on sparse observations in the field which allow reasonable simulations with a physically based hydrological model. Copyright  2005 John Wiley & Sons, Ltd. KEY WORDS rainfall-induced landslides; soil creep; hydrological modelling; Vorarlberg; Austria; pressure propagation Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-60226 ER - TY - GEN A1 - Thiel, Marco A1 - Romano, Maria Carmen A1 - Kurths, Jürgen A1 - Rolfs, Martin T1 - Twin Surrogates to Test for Complex Synchronisation N2 - We present an approach to generate (multivariate) twin surrogates (TS) based on recurrence properties. This technique generates surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system starting at different initial conditions. We show that these surrogates are well suited to test for complex synchronisation and exemplify this for the paradigmatic system of R¨ossler oscillators. The proposed test enables to assess the statistical relevance of a synchronisation analysis from passive experiments which are typical in natural systems. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 264 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57231 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Nuthmann, Antje A1 - Engbert, Ralf T1 - Tracking the Mind During Reading: The Influence of Past, Present, and Future Words on Fixation Durations N2 - Reading requires the orchestration of visual, attentional, language-related, and oculomotor processing constraints. This study replicates previous effects of frequency, predictability, and length of fixated words on fixation durations in natural reading and demonstrates new effects of these variables related to previous and next words. Results are based on fixation durations recorded from 222 persons, each reading 144 sentences. Such evidence for distributed processing of words across fixation durations challenges psycholinguistic immediacy-of-processing and eye-mind assumptions. Most of the time the mind processes several words in parallel at different perceptual and cognitive levels. Eye movements can help to unravel these processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 263 KW - eye movements KW - fixation duration KW - gaze KW - word recognition KW - reading Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57225 ER - TY - GEN A1 - Dambacher, Michael A1 - Kliegl, Reinhold T1 - Synchronizing timelines: Relations between fixation durations and N400 amplitudes during sentence reading N2 - We examined relations between eye movements (single-fixation durations) and RSVP-based event-related potentials (ERPs; N400’s) recorded during reading the same sentences in two independent experiments. Longer fixation durations correlated with larger N400 amplitudes. Word frequency and predictability of the fixated word as well as the predictability of the upcoming word accounted for this covariance in a path-analytic model. Moreover, larger N400 amplitudes entailed longer fixation durations on the next word, a relation accounted for by word frequency. This pattern offers a neurophysiological correlate for the lag-word frequency effect on fixation durations: Word processing is reliably expressed not only in fixation durations on currently fixated words, but also in those on subsequently fixated words. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 262 KW - sentence reading KW - eye-movements KW - fixation durations KW - rapid serial visual presentation (RSVP) KW - event-related potentials (ERP) KW - N400 KW - path analysis Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57212 ER - TY - GEN A1 - Hohenstein, Sven A1 - Laubrock, Jochen A1 - Kliegl, Reinhold T1 - Semantic preview benefit in eye movements during reading: a parafoveal past-priming study N2 - Eye movements in reading are sensitive to foveal and parafoveal word features. Whereas the influence of orthographic or phonological parafoveal information on gaze control is undisputed, there has been no reliable evidence for early parafoveal extraction of semantic information in alphabetic script. Using a novel combination of the gaze-contingent fast-priming and boundary paradigms, we demonstrate semantic preview benefit when a semantically related parafoveal word was available during the initial 125 ms of a fixation on the pre-target word (Experiments 1 and 2). When the target location was made more salient, significant parafoveal semantic priming occurred only at 80 ms (Experiment 3). Finally, with short primes only (20, 40, 60 ms) effects were not significant but numerically in the expected direction for 40 and 60 ms (Experiment 4). In all experiments, fixation durations on the target word increased with prime durations under all conditions. The evidence for extraction of semantic information from the parafoveal word favors an explanation in terms of parallel word processing in reading. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 261 KW - eye movements KW - reading KW - parafoveal preview KW - semantic priming Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57203 ER - TY - GEN A1 - Kliegl, Reinhold T1 - Publication Statistics Show Collaboration, Not Competition T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 258 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57198 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Risse, Sarah A1 - Laubrock, Jochen T1 - Preview Benefit and Parafoveal-on-Foveal Effects from Word N+2 N2 - Using the gaze-contingent boundary paradigm with the boundary placed after word n, we manipulated preview of word n+2 for fixations on word n. There was no preview benefit for first-pass reading on word n+2, replicating the results of Rayner, Juhasz, and Brown (2007), but there was a preview benefit on the three-letter word n+1, that is, after the boundary, but before word n+2. Additionally, both word n+1 and word n+2 exhibited parafoveal-on-foveal effects on word n. Thus, during a fixation on word n and given a short word n+1, some information is extracted from word n+2, supporting the hypothesis of distributed processing in the perceptual span. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 257 KW - eye movements KW - reading KW - preview benefit KW - parafoveal-on-foveal effects Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57186 ER - TY - GEN A1 - Valsecchi, Matteo A1 - Dimigen, Olaf A1 - Kliegl, Reinhold A1 - Sommer, Werner A1 - Turatto, Massimo T1 - Microsaccadic Inhibition and P300 Enhancement in a Visual Oddball Task N2 - It has recently been demonstrated that the presentation of a rare target in a visual oddball paradigm induces a prolonged inhibition of microsaccades. In the field of electrophysiology, the amplitude of the P300 component in event-related potentials (ERP) has been shown to be sensitive to the stimulus category (target vs. non target) of the eliciting stimulus, its overall probability, and the preceding stimulus sequence. In the present study we further specify the functional underpinnings of the prolonged microsaccadic inhibition in the visual oddball task, showing that the stimulus category, the frequency of a stimulus and the preceding stimulus sequence influence microsaccade rate. Furthermore, by co-recording ERPs and eye-movements, we were able to demonstrate that, despite being largely sensitive to the same experimental manipulation, the amplitude of P300 and the microsaccadic inhibition predict each other very weakly, and thus constitute two independent measures of the brain’s response to rare targets in the visual oddball paradigm. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 256 KW - Visual Oddball Paradigm KW - Microsaccades KW - Microsaccadic Inhibition KW - ERPs KW - P300Psychophysiology KW - 46 (3) 2009 KW - S. 635-644 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57170 ER - TY - GEN A1 - Fanselow, Gisbert A1 - Schlesewsky, Matthias A1 - Cavar, Damir A1 - Kliegl, Reinhold T1 - Optimal parsing: syntactic parsing preferences and optimality theory T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 255 Y1 - 1999 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57164 ER - TY - GEN A1 - Boston, Marisa Ferrara A1 - Hale, John T. A1 - Vasishth, Shravan A1 - Kliegl, Reinhold T1 - Parallel processing and sentence comprehension difficulty N2 - Eye fixation durations during normal reading correlate with processing difficulty but the specific cognitive mechanisms reflected in these measures are not well understood. This study finds support in German readers’ eyefixations for two distinct difficulty metrics: surprisal, which reflects the change in probabilities across syntactic analyses as new words are integrated, and retrieval, which quantifies comprehension difficulty in terms of working memory constraints. We examine the predictions of both metrics using a family of dependency parsers indexed by an upper limit on the number of candidate syntactic analyses they retain at successive words. Surprisal models all fixation measures and regression probability. By contrast, retrieval does not model any measure in serial processing. As more candidate analyses are considered in parallel at each word, retrieval can account for the same measures as surprisal. This pattern suggests an important role for ranked parallelism in theories of sentence comprehension. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 252 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57159 ER - TY - GEN A1 - Engbert, Ralf A1 - Nuthmann, Antje A1 - Richter, Eike M. A1 - Kliegl, Reinhold T1 - SWIFT: A Dynamical Model of Saccade Generation during Reading N2 - Mathematical models have become an important tool for understanding the control of eye movements during reading. Main goals of the development of the SWIFT model (Engbert, Longtin, & Kliegl, 2002)were to investigate the possibility of spatially distributed processing and to implement a general mechanism for all types of eye movements we observe in reading experiments. Here, we present an advanced version of SWIFT which integrates properties of the oculomotor system and effects of word recognition to explain many of the experimental phenomena faced in reading research. We propose new procedures for the estimation of model parameters and for the test of the model’s performance. A mathematical analysis of the dynamics of the SWIFT model is presented. Finally, within this framework, we present an analysis of the transition from parallel to serial processing. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 254 Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57145 ER - TY - GEN A1 - Boston, Marisa Ferrara A1 - Hale, John A1 - Kliegl, Reinhold A1 - Patil, Umesh A1 - Vasishth, Shravan T1 - Parsing costs as predictors of reading difficulty: An evaluation using the Potsdam Sentence Corpus N2 - The surprisal of a word on a probabilistic grammar constitutes a promising complexity metric for human sentence comprehension difficulty. Using two different grammar types, surprisal is shown to have an effect on fixation durations and regression probabilities in a sample of German readers’ eye movements, the Potsdam Sentence Corpus. A linear mixed-effects model was used to quantify the effect of surprisal while taking into account unigram and bigram frequency, word length, and empirically-derived word predictability; the so-called “early” and “late” measures of processing difficulty both showed an effect of surprisal. Surprisal is also shown to have a small but statistically non-significant effect on empirically-derived predictability itself. This work thus demonstrates the importance of including parsing costs as a predictor of comprehension difficulty in models of reading, and suggests that a simple identification of syntactic parsing costs with early measures and late measures with durations of post-syntactic events may be difficult to uphold. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 253 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57139 ER - TY - GEN A1 - Angele, Bernhard A1 - Slattery, Timothy J. A1 - Yang, Jinmian A1 - Kliegl, Reinhold A1 - Rayner, Keith T1 - Parafoveal processing in reading: Manipulating n+1 and n+2 previews simultaneously N2 - The boundary paradigm (Rayner, 1975) with a novel preview manipulation was used to examine the extent of parafoveal processing of words to the right of fixation. Words n+1 and n+2 had either correct or incorrect previews prior to fixation (prior to crossing the boundary location). In addition, the manipulation utilized either a high or low frequency word in word n+1 location on the assumption that it would be more likely that n+2 preview effects could be obtained when word n+1 was high frequency. The primary findings were that there was no evidence for a preview benefit for word n+2 and no evidence for parafoveal-on-foveal effects when word n+1 is at least four letters long. We discuss implications for models of eye-movement control in reading. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 251 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57128 ER - TY - GEN A1 - Ming, Yan A1 - Kliegl, Reinhold A1 - Shu, Hua A1 - Pan, Jinger A1 - Zhou, Xiaolin T1 - Parafoveal Load of Word N+1 Modulates Preprocessing Effectivenessof Word N+2 in Chinese Reading N2 - Preview benefits (PBs) from two words to the right of the fixated one (i.e., word N+2)and associated parafoveal-on-foveal effects are critical for proposals of distributed lexical processing during reading. This experiment examined parafoveal processing during reading of Chinese sentences, using a boundary manipulation of N+2-word preview with low- and high-frequency words N+1. The main findings were (a) an identity PB for word N+2 that was (b) primarily observed when word N+1 was of high frequency (i.e., an interaction between frequency of word N+1 and PB for word N+2), and (c) a parafoveal-on-foveal frequency effect of word N+1 for fixation durations on word N. We discuss implications for theories of serial attention shifts and parallel distributed processing of words during reading. T2 - Ming Yan; Reinhold Kliegl; Hua Shu; Jinger Pan; Xiaolin Zhou T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 250 Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57103 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Rolfs, Martin A1 - Laubrock, Jochen A1 - Engbert, Ralf T1 - Microsaccadic Modulation of Response Times in Spatial Attention Tasks N2 - Covert shifts of attention are usually reflected in RT differences between responses to valid and invalid cues in the Posner spatial attention task. Such inferences about covert shifts of attention do not control for microsaccades in the cue target interval. We analyzed the effects of microsaccade orientation on RTs in four conditions, crossing peripheral visual and auditory cues with peripheral visual and auditory discrimination targets. Reaction time was generally faster on trials without microsaccades in the cue-target interval. If microsaccades occurred, the target-location congruency of the last microsaccade in the cuetarget interval interacted in a complex way with cue validity. For valid visual cues, irrespective of whether the discrimination target was visual or auditory, target-congruent microsaccades delayed RT. For invalid cues, target-incongruent microsaccades facilitated RTs for visual target discrimination, but delayed RT for auditory target discrimination. No reliable effects on RT were associated with auditory cues or with the first microsaccade in the cue-target interval. We discuss theoretical implications on the relation about spatial attention and oculomotor processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 249 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57098 ER - TY - GEN A1 - Rolfs, Martin A1 - Kliegl, Reinhold A1 - Engbert, Ralf T1 - Microsaccade orientation supports attentional enhancement opposite to a peripheral cue: Commentary on Tse, Sheinberg, and Logothetis T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 248 Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57081 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Masson, Michael E. J. A1 - Richter, Eike M. T1 - A linear mixed model analysis of masked repetition priming N2 - We examined individual differences in masked repetition priming by re-analyzing item-level response-time (RT) data from three experiments. Using a linear mixed model (LMM) with subjects and items specified as crossed random factors, the originally reported priming and word-frequency effects were recovered. In the same LMM, we estimated parameters describing the distributions of these effects across subjects. Subjects’ frequency and priming effects correlated positively with each other and negatively with mean RT. These correlation estimates, however, emerged only with a reciprocal transformation of RT (i.e., -1/RT), justified on the basis of distributional analyses. Different correlations, some with opposite sign, were obtained (1) for untransformed or logarithmic RTs or (2) when correlations were computed using within-subject analyses. We discuss the relevance of the new results for accounts of masked priming, implications of applying RT transformations, and the use of LMMs as a tool for the joint analysis of experimental effects and associated individual differences. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 247 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57073 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Philipp, Doris A1 - Luckner, Matthias A1 - Krampe, Ralf T. T1 - Face Memory Skill Acquisition T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 246 Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57067 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Bates, Douglas T1 - International Collaboration in Psychology is on the Rise N2 - There has been a substantial increase in the percentage for publications with co-authors located in departments from different countries in 12 major journals of psychology. The results are evidence for a remarkable internationalization of psychological research, starting in the mid 1970s and increasing in rate at the beginning of the 1990s. This growth occurs against a constant number of articles with authors from the same country; it is not due to a concomitant increase in the number of co-authors per article. Thus, international collaboration in psychology is obviously on the rise. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 244 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57045 ER - TY - GEN A1 - Rolfs, Martin A1 - Laubrock, Jochen A1 - Kliegl, Reinhold T1 - Shortening and Prolongation of Saccade Latencies Following Microsaccades N2 - When the eyes fixate at a point in a visual scene, small saccades rapidly shift the image on the retina. The effect of these microsaccades on the latency of subsequent large-scale saccades may be twofold. First, microsaccades are associated with an enhancement of visual perception. Their occurrence during saccade target perception should, thus, decrease saccade latencies. On the other hand, microsaccades likely indicate activity in fixation-related oculomotor neurons. These represent competitors to saccade-related cells in the interplay of gaze holding and shifting. Consequently, an increase in saccade latencies after microsaccades would be expected. Here, we present evidence for both aspects of microsaccadic impact on saccade latency. In a delayed response task, participants made saccades to visible or memorized targets. First, microsaccade occurrence up to 50 ms before target disappearance correlated with 18 ms (or 8%) faster saccades to memorized targets. Second, if microsaccades occurred shortly (i.e., < 150 ms) before a saccade was required, saccadic reaction times in visual and memory trials were increased by about 40 ms (or 16%). Hence, microsaccades can have opposite consequences for saccade latencies, pointing at a differential role of these fixational eye movements in preparation of motor programs. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 242 KW - Fixational eye movements KW - Memory-guided saccades KW - Visually-guided saccades Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57012 ER - TY - GEN A1 - Risse, Sarah A1 - Kliegl, Reinhold T1 - Adult age differences in the perceptual span during reading N2 - Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, & Yang, 2009), we compared old and young adults in an N+2-boundary paradigm in which a nonword preview of word N+2 or word N+2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N+1 was always three letters long. Gaze durations on word N+2 were significantly shorter for identical than nonword N+2 preview both for young and for old adults with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N+1. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 241 KW - age differences KW - perceptual span KW - N+2-boundary paradigm KW - preview benefit KW - parafoveal-on-foveal effect KW - compensation strategies Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56935 ER - TY - GEN A1 - Dimigen, Olaf A1 - Valsecchi, Matteo A1 - Sommer, Werner A1 - Kliegl, Reinhold T1 - Human Microsaccade-Related Visual Brain Responses N2 - Microsaccades are very small, involuntary flicks in eye position that occur on average once or twice per second during attempted visual fixation. Microsaccades give rise to EMG eye muscle spikes that can distort the spectrum of the scalp EEG and mimic increases in gamma band power. Here we demonstrate that microsaccades are also accompanied by genuine and sizeable cortical activity, manifested in the EEG. In three experiments, high-resolution eye movements were corecorded with the EEG: during sustained fixation of checkerboard and face stimuli and in a standard visual oddball task that required the counting of target stimuli. Results show that microsaccades as small as 0.15° generate a field potential over occipital cortex and midcentral scalp sites 100 –140 ms after movement onset, which resembles the visual lambda response evoked by larger voluntary saccades. This challenges the standard assumption of human brain imaging studies that saccade-related brain activity is precluded by fixation, even when fully complied with. Instead, additional cortical potentials from microsaccades were present in 86% of the oddball task trials and of similar amplitude as the visual response to stimulus onset. Furthermore, microsaccade probability varied systematically according to the proportion of target stimuli in the oddball task, causing modulations of late stimulus-locked event-related potential (ERP) components. Microsaccades present an unrecognized source of visual brain signal that is of interest for vision research and may have influenced the data of many ERP and neuroimaging studies. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 240 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56923 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Engbert, Ralf T1 - How tight is the link between lexical processing and saccade programs? N2 - We question the assumption of serial attention shifts and the assumption that saccade programs are initiated or canceled only after stage one of word identification. Evidence: (1) Fixation durations prior to skipped words are not consistently higher compared to those prior to nonskipped words. (2) Attentional modulation of microsaccade rate might occur after early visual processing. Saccades are probably triggered by attentional selection. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 239 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56919 ER - TY - GEN A1 - Thiel, Marco A1 - Romano, Maria Carmen A1 - Kurths, Jürgen A1 - Rolfs, Martin A1 - Kliegl, Reinhold T1 - Generating Surrogates from Recurrences N2 - In this paper we present an approach to recover the dynamics from recurrences of a system and then generate (multivariate) twin surrogate (TS) trajectories. In contrast to other approaches, such as the linear-like surrogates, this technique produces surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system visiting the attractor in a different way. We show that these surrogates are well suited to test for complex synchronization, which makes it possible to systematically assess the reliability of synchronization analyses. We then apply the TS to study binocular fixational movements and find strong indications that the fixational movements of the left and right eye are phase synchronized. This result indicates that there might be one centre only in the brain that produces the fixational movements in both eyes or a close link between two centres. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 238 KW - Æ Recurrence Plots KW - Surrogate Data KW - Hypothesis Test KW - Phase Synchronization Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56906 ER - TY - GEN A1 - Engbert, Ralf A1 - Kliegl, Reinhold T1 - The game of word skipping: Who are the competitors? N2 - Computational models such as E-Z Reader and SWIFT are ideal theoretical tools to test quantitatively our current understanding of eye-movement control in reading. Here we present a mathematical analysis of word skipping in the E-Z Reader model by semianalytic methods, to highlight the differences in current modeling approaches. In E-Z Reader, the word identification system must outperform the oculomotor system to induce word skipping. In SWIFT, there is competition among words to be selected as a saccade target. We conclude that it is the question of competitors in the “game” of word skipping that must be solved in eye movement research. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 237 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56899 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Wei, Ping A1 - Dambacher, Michael A1 - Yan, Ming A1 - Zhou, Xiaolin T1 - Experimental effects and individual differences in linear mixed models: Estimating the relationship between spatial, object, and attraction effects in visual attention N2 - Linear mixed models (LMMs) provide a still underused methodological perspective on combining experimental and individual-differences research. Here we illustrate this approach with two-rectangle cueing in visual attention (Egly et al., 1994). We replicated previous experimental cue-validity effects relating to a spatial shift of attention within an object (spatial effect), to attention switch between objects (object effect), and to the attraction of attention toward the display centroid (attraction effect), also taking into account the design-inherent imbalance of valid and other trials. We simultaneously estimated variance/covariance components of subject-related random effects for these spatial, object, and attraction effects in addition to their mean reaction times (RTs). The spatial effect showed a strong positive correlation with mean RT and a strong negative correlation with the attraction effect. The analysis of individual differences suggests that slow subjects engage attention more strongly at the cued location than fast subjects. We compare this joint LMM analysis of experimental effects and associated subject-related variances and correlations with two frequently used alternative statistical procedures T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 236 KW - linear mixed model KW - individual differences KW - visual attention KW - spatial attention KW - object-based attention Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56859 ER - TY - GEN A1 - Rolfs, Martin A1 - Engbert, Ralf A1 - Kliegl, Reinhold T1 - Crossmodal coupling of oculomotor controland spatial attention in vision and audition N2 - Fixational eye movements occur involuntarily during visual fixation of stationary scenes. The fastest components of these miniature eye movements are microsaccades, which can be observed about once per second. Recent studies demonstrated that microsaccades are linked to covert shifts of visual attention [e.g., Engbert & Kliegl (2003), Vision Res 43:1035-1045]. Here,we generalized this finding in two ways. First, we used peripheral cues, rather than the centrally presented cues of earlier studies. Second, we spatially cued attention in vision and audition to visual and auditory targets. An analysis of microsaccade responses revealed an equivalent impact of visual and auditory cues on microsaccade-rate signature (i.e., an initial inhibition followed by an overshoot and a final return to the pre-cue baseline rate). With visual cues or visual targets,microsaccades were briefly aligned with cue direction and then opposite to cue direction during the overshoot epoch, probably as a result of an inhibition of an automatic saccade to the peripheral cue. With left auditory cues and auditory targets microsaccades oriented in cue direction. Thus, microsaccades can be used to study crossmodal integration of sensory information and to map the time course of saccade preparation during covert shifts of visual and auditory attention. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 234 KW - Microsaccades KW - Covert orienting KW - Fixational eye movements KW - Multisensory Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56804 ER - TY - GEN A1 - Ong, James Kwan Yau A1 - Kliegl, Reinhold T1 - Conditional co-occurrence probability acts like frequency in predicting fixation durations N2 - The predictability of an upcoming word has been found to be a useful predictor in eye movement research, but is expensive to collect and subjective in nature. It would be desirable to have other predictors that are easier to collect and objective in nature if these predictors were capable of capturing the information stored in predictability. This paper contributes to this discussion by testing a possible predictor: conditional co-occurrence probability. This measure is a simple statistical representation of the relatedness of the current word to its context, based only on word co-occurrence patterns in data taken from the Internet. In the regression analyses, conditional co-occurrence probability acts like lexical frequency in predicting fixation durations, and its addition does not greatly improve the model fits. We conclude that readers do not seem to use the information contained within conditional co-occurrence probability during reading for meaning, and that similar simple measures of semantic relatedness are unlikely to be able to replace predictability as a predictor for fixation durations. Keywords: Co-occurrence probability, Cloze predictability, frequency, eye movement, fixation duration. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 232 KW - Co-occurrence probability KW - Cloze predictability KW - eye movement KW - frequency KW - fixation duration Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56771 ER - TY - GEN A1 - Busch, Jan Philip A1 - Meißner, Tobias A1 - Potthoff, Annegret A1 - Oswald, Sascha T1 - Plating of nano zero-valent iron (nZVI) on activated carbon : a fast delivery method of iron for source remediation? N2 - The use of nano zerovalent iron (nZVI) for environmental remediation is a promising new technique for in situ remediation. Due to its high surface area and high reactivity, nZVI is able to dechlorinate organic contaminants and render them harmless. Limited mobility, due to fast aggregation and sedimentation of nZVI, limits the capability for source and plume remediation. Carbo-Iron is a newly developed material consisting of activated carbon particles (d50 = 0,8 µm) that are plated with nZVI particles. These particles combine the mobility of activated carbon and the reactivity of nZVI. This paper presents the first results of the transport experiments. N2 - Der Einsatz von elementarem Nanoeisen ist eine vielversprechende Technik zur Sanierung von Altlastenschadensfällen. Aufgrund der hohen Oberfläche und der hohen Reaktivität kannn ZVI chlororganische Schadstoffe dechlorieren und zu harmlosen Substanzen umwandeln. Der Einsatz von Nanoeisen zur Quellen- und Fahnensanierung wird jedoch durch mangelnde Mobilität im Boden im eingeschränkt. Carbo-Iron ist ein neu entwickeltes Material, das aus Aktivkohlepartikeln (d50 = 0,8 µm) und nZVI besteht. Diese Partikel kombinieren die Mobilit ät von Aktivkohle mit der Reaktivität von nZVI. Dieser Artikel beschreibt erste Ergebnisse von Transportuntersuchungen. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 165 KW - Carbo-Iron KW - Nanoeisen KW - nZVI KW - Grundwassersanierung KW - Carbo-Iron KW - nano zero-valent iron KW - nZVI KW - remediation Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-53792 ER - TY - GEN A1 - Gardemann, Andreas A1 - Püschel, Gerhard Paul A1 - Jungermann, Kurt T1 - Nervous control of liver metabolism and hemodynamics N2 - Content: Anatomy of hepatic innervation In vivo studies on the role of hepatic nerves Effects of hepatic nerves in isolated perfused liver Mechanism of action of sympathetic hepatic nerves T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 164 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-51346 ER - TY - GEN A1 - Plath, Martin A1 - Hermann, Bernd A1 - Schröder, Christine A1 - Riesch, Rüdiger A1 - Tobler, Michael A1 - García de León, Francisco J. A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - Locally adapted fish populations maintain small-scale genetic differentiation despite perturbation by a catastrophic flood event N2 - Background: Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence, lead to speciation. Perturbations by catastrophic events, however, can distort such parapatric ecological speciation processes. Here, we asked whether an exceptionally strong flood led to homogenization of gene pools among locally adapted populations of the Atlantic molly (Poecilia mexicana, Poeciliidae) in the Cueva del Azufre system in southern Mexico, where two strong environmental selection factors (darkness within caves and/or presence of toxic H2S in sulfidic springs) drive the diversification of P. mexicana. Nine nuclear microsatellites as well as heritable female life history traits (both as a proxy for quantitative genetics and for trait divergence) were used as markers to compare genetic differentiation, genetic diversity, and especially population mixing (immigration and emigration) before and after the flood. Results: Habitat type (i.e., non-sulfidic surface, sulfidic surface, or sulfidic cave), but not geographic distance was the major predictor of genetic differentiation. Before and after the flood, each habitat type harbored a genetically distinct population. Only a weak signal of individual dislocation among ecologically divergent habitat types was uncovered (with the exception of slightly increased dislocation from the Cueva del Azufre into the sulfidic creek, El Azufre). By contrast, several lines of evidence are indicative of increased flood-induced dislocation within the same habitat type, e.g., between different cave chambers of the Cueva del Azufre. Conclusions: The virtual absence of individual dislocation among ecologically different habitat types indicates strong natural selection against migrants. Thus, our current study exemplifies that ecological speciation in this and other systems, in which extreme environmental factors drive speciation, may be little affected by temporary perturbations, as adaptations to physico-chemical stressors may directly affect the survival probability in divergent habitat types. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 162 Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48599 ER - TY - GEN A1 - Jeličić, Aleksandra A1 - Friedrich, Alwin A1 - Jeremić, Katarina A1 - Siekmeyer, Gerd A1 - Taubert, Andreas T1 - Polymer hydrogel/polybutadiene/iron oxide nanoparticle hybrid actuators for the characterization of NiTi implants N2 - One of the main issues with the use of nickel titanium alloy (NiTi) implants in cardiovascular implants (stents) is that these devices must be of very high quality in order to avoid subsequent operations due to failing stents. For small stents with diameters below ca. 2 mm, however, stent characterization is not straightforward. One of the main problems is that there are virtually no methods to characterize the interior of the NiTi tubes used for fabrication of these tiny stents. The current paper reports on a robust hybrid actuator for the characterization of NiTi tubes prior to stent fabrication. The method is based on a polymer/hydrogel/magnetic nanoparticle hybrid material and allows for the determination of the inner diameter at virtually all places in the raw NiTi tubes. Knowledge of the inner structure of the raw NiTi tubes is crucial to avoid regions that are not hollow or regions that are likely to fail due to defects inside the raw tube. The actuator enables close contact of a magnetic polymer film with the inner NiTi tube surface. The magnetic signal can be detected from outside and be used for a direct mapping of the tube interior. As a result, it is possible to detect critical regions prior to expensive and slow stent fabrication processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 161 KW - NiTi KW - inner surface KW - hydrogel KW - polybutadiene KW - magnetic nanoparticles Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48589 ER - TY - GEN A1 - Bielawski, Martina A1 - Jurišić, J. A1 - Lenz, T. A1 - Maxian Rusche, T. A1 - Nippert, C. T1 - Via : communis Europa ; Europe's architecture in 2020 N2 - Forum: EU-Diplomatie im Jahre 2020 KW - Europäische Union KW - Europaidentität KW - Außenpolitik KW - Verteidigungspolitik KW - European Union KW - European identity KW - foreign policy KW - defence policy Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48454 ER - TY - GEN A1 - Koasidis, Jannis T1 - Bridges to the east : Poland and the European foreign policy by 2020 N2 - Forum: EU-Diplomatie im Jahre 2020 KW - Gemeinsame Außen- und Sicherheitspolitik KW - Europäische Union KW - Europäische Nachbarschaftspolitik KW - Ostpolitik KW - Common Foreign and Security Policy KW - European Union KW - European Neighborhood Policy KW - Eastern policy Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48404 ER - TY - GEN A1 - Christmann, Olivia A1 - Warlouzet, Laurent T1 - Scenarios of "Europe-puissance" : the French foreign policy in Europe by 2020 N2 - Forum: EU-Diplomatie im Jahre 2020 KW - Europäische Verfassung KW - Supermacht KW - Politik KW - Wirtschaft KW - Regierungskooperation KW - European Constitution KW - superpower KW - politics KW - economy KW - intergovernmental cooperation Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48399 ER - TY - GEN A1 - Jacobi-Dittrich, Juliane T1 - Growing up female in the nineteenth century N2 - Content: I Konnte ich nicht auch ein Wolkenschwimmer werden? II La réalité ne se forme que dans la memoire. III Girls in the family - Sexuality and eroticism before and after puberty - Searching for and selecting a husband - School and girls' education IV Normal childhood experiences T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 213 Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-47705 ER - TY - GEN A1 - Jacobi-Dittrich, Juliane T1 - Compulsory education for german immigrant children in the United States of America during the second half of the nineteenth century : the case of rural Wisconsin T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 212 Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-47690 ER - TY - GEN A1 - Zapf, Wolfgang T1 - Modernization theory – in the non-western world N2 - The article starts with an overview of modernization theories, its history of ups and downs as well as its present status. This first part is followed by an analysis of basic social structure distributions and trends in human development in selected countries. One major focal point of the paper is the Non-Western world and the Arab countries, in particular. The author looks at modernization and modernity in that region and comes to the conclusion that the Western world can no longer expect to be able to simply export its own values and its way of life to the rest of the world. KW - Modernisierung KW - Moderne KW - Modernisierungstheorie KW - Modernization KW - modernity KW - modernization theory Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-47181 ER - TY - GEN A1 - Abdollahyan, Hamid T1 - The generations gap in contemporary Iran N2 - This paper offers a new theoretical framework for studying the problem of generations and social change in contemporary Iran. It offers a model which is called „articulation of cultural modes“. The paper agrees with Ronald Inglehart that ‘culture’ is now playing a more dominant role in the social formation of current societies, as ‘technology’ once did in the modern era. But it goes one step further by arguing that culture cannot be approached as a holistic concept building on a comprehensive theoretical framework. KW - Iran KW - Gesellschaftstheorie KW - Kulturwissenschaft KW - Iran KW - social theory KW - cultural studies Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-47167 ER - TY - GEN A1 - Nateghpour, Mohamad Javad T1 - Islamic councils and social democracy in Iran N2 - For the first time when the new Islamic councils began their Operation, many intellectuals and politicians proclaimed that there would be no room for the young Islamic councils to proceed. In political terms, because of the new challenges between the rightists and leftists, many people had no hope to see the results of the councils. Still others believed that under the dominating ruling system of Iran there is no space for public opinion and participation in local decision-making. This paper focuses on the role of the Islamic Councils as a new form of social democracy, which decentralizes power and creates good local governance. The paper also discusses the obstacles for the Councils in the development of the region. KW - Iran KW - Modernisierung KW - Islam KW - Iran KW - modernization KW - Islam Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-47145 ER - TY - GEN A1 - Reich, Sebastian T1 - On the local qualitative behavior of differential-algebraic equations N2 - A theoretical famework for the investigation of the qualitative behavior of differential-algebraic equations (DAEs) near an equilibrium point is established. The key notion of our approach is the notion of regularity. A DAE is called regular locally around an equilibrium point if there is a unique vector field such that the solutions of the DAE and the vector field are in one-to-one correspondence in a neighborhood of this equili Drium point. Sufficient conditions for the regularity of an equilibrium point are stated. This in turn allows us to translate several local results, as formulated for vector fields, to DAEs that are regular locally around a g: ven equilibrium point (e.g. Local Stable and Unstable Manifold Theorem, Hopf theorem). It is important that ihese theorems are stated in terms of the given problem and not in terms of the corresponding vector field. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 159 Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46739 ER - TY - GEN A1 - Reich, Sebastian T1 - On an existence and uniqueness theory for nonlinear differential-algebraic equations N2 - An existence and uniqueness theory is developed for general nonlinear and nonautonomous differential-algebraic equations (DAEs) by exploiting their underlying differential-geometric structure. A DAE is called regular if there is a unique nonautonomous vector field such that the solutions of the DAE and the solutions of the vector field are in one-to-one correspondence. Sufficient conditions for regularity of a DAE are derived in terms of constrained manifolds. Based on this differential-geometric characterization, existence and uniqueness results are stated for regular DAEs. Furthermore, our not ons are compared with techniques frequently used in the literature such as index and solvability. The results are illustrated in detail by means of a simple circuit example. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 158 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46706 ER - TY - GEN A1 - Pedersen, Karin Hilmer A1 - Johannsen, Lars T1 - The real challenge for change : public administration in new EU member states N2 - Executive responsibility for EU policies is by tradition delegated to the member states and their internal administrative bodies. It is therefore of outmost importance that the new Central and East European members have the capacity to administer the acquis communitaire once they are full members of the EU. Based on a survey among current and former top-level decision-makers (ministers), this article argues that although there are significant implementation problems, efficiency gains can be made through administrative reform and not the least education aimed at changing the worldview and knowledge of the individual civil servant. However, there seem to be significant differences in how these countries tackle implementation problems and administrative reform. KW - Europäische Union KW - öffentliche Verwaltung KW - European Union KW - public administration Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46718 ER - TY - GEN A1 - Reich, Sebastian T1 - On a geometrical interpretation of differential-algebraic equations N2 - The subject of this paper is the relation of differential-algebraic equations (DAEs) to vector fields on manifolds. For that reason, we introduce the notion of a regular DAE as a DAE to which a vector field uniquely corresponds. Furthermore, a technique is described which yields a family of manifolds for a given DAE. This socalled family of constraint manifolds allows in turn the formulation of sufficient conditions for the regularity of a DAE. and the definition of the index of a regular DAE. We also state a method for the reduction of higher-index DAEs to lowsr-index ones that can be solved without introducing additional constants of integration. Finally, the notion of realizability of a given vector field by a regular DAE is introduced, and it is shown that any vector field can be realized by a regular DAE. Throughout this paper the problem of path-tracing is discussed as an illustration of the mathematical phenomena. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 157 Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46683 ER - TY - GEN A1 - Reich, Sebastian T1 - Differential-algebraic equations and applications in circuit theory N2 - Technical and physical systems, especially electronic circuits, are frequently modeled as a system of differential and nonlinear implicit equations. In the literature such systems of equations are called differentialalgebraic equations (DAEs). It turns out that the numerical and analytical properties of a DAE depend on an integer called the index of the problem. For example, the well-known BDF method of Gear can be applied, in general, to a DAE only if the index does not exceed one. In this paper we give a geometric interpretation of higherindex DAEs and indicate problems arising in connection with such DAEs by means of several examples. N2 - Die mathematische Modellierung technisch physikalischer Systeme wie elektrische Netzwerke, führt häufig auf ein System von Differentialgleichungen und nichtlinearen impliziten Gleichungen sogenannten Algebrodifferentialgleichungen (ADGL). Es zeigt sich, daß die numerischen und analytischen Eigenschaften von ADGL durch den Index des Problems charakterisiert werden können. Insbesondere können die bekannten Integrationsformeln von Gear im allgemeinen nur auf ADGL mit dem Index eins angewendet werden. In diesem Beitrag wird eine geometrische Interpretation von ADGL mit einem höheren Index gegeben sowie auf Probleme im Zusammenhang mit derartigen ADGL an Hand verschiedener Beispiele hingewiesen. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 156 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46646 ER - TY - GEN A1 - Campbell, Edwina S. T1 - Berlin : look to the world! N2 - In the spring 2004 issue of WeltTrends, Professor Gunther Hellmann made a „plea for offensive idealism“ and „against the power political resocialization of German foreign policy“. To a long-time outside observer of that foreign policy, this plea is unsurprising, but depressing. In keeping with Professor Hellmann’s own willingness, „notwendige Differenzierungen [zu] vernachlässigen zugunsten einer bewussten Zuspitzung“ I will comment on the aspects of his argument that strike an American colleague as particularly disturbing. KW - Deutschland KW - Außenpolitik KW - Resozialisierung KW - Germany KW - foreign policy KW - resocialisation Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46591 ER - TY - GEN A1 - Winkler, Eckart A1 - Heinken, Thilo T1 - Spread of an ant-dispersed annual herb : an individual-based simulation study on population development of Melampyrum pratense L. N2 - The paper presents a simulation and parameter-estimation approach for evaluating stochastic patterns of population growth and spread of an annual forest herb, Melampyrum pratense (Orobanchaceae). The survival of a species during large-scale changes in land use and climate will depend, to a considerable extent, on its dispersal and colonisation abilities. Predictions on species migration need a combination of field studies and modelling efforts. Our study on the ability of M. pratense to disperse into so far unoccupied areas was based on experiments in secondary woodland in NE Germany. Experiments started in 1997 at three sites where the species was not yet present, with 300 seeds sown within one square meter. Population development was then recorded until 2001 by mapping of individuals with a resolution of 5 cm. Additional observations considered density dependence of seed production. We designed a spatially explicit individual-based computer simulation model to explain the spatial patterns of population development and to predict future population spread. Besides primary drop of seeds (barochory) it assumed secondary seed transport by ants (myrmecochory) with an exponentially decreasing dispersal tail. An important feature of populationpattern explanation was the simultaneous estimation of both population-growth and dispersal parameters from consistent spatio-temporal data sets. As the simulation model produced stochastic time series and random spatially discrete distributions of individuals we estimated parameters by minimising the expectation of weighted sums of squares. These sums-ofsquares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25*25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sums of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1…2 m was indispensable for explaining the observed population spread that led to distances of at most 8 m from population origin within 3 years. Projections of population development over 4 additional years gave a diffusion-like increase of population area without any “outposts”. This prediction generated by the simulation model gave a hypothesis which should be revised by additional field observations. Some structural deviations between observations and model output already indicated that for full understanding of population spread the set of dispersal mechanisms assumed in the model may have to be extended by additional features of plant-animal mutualism. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 152 KW - Pattern-oriented parameter estimation KW - spatially explicit modelling KW - individual-based model KW - Melampyrum pratense KW - seed dispersal Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46491 ER - TY - GEN A1 - Heinken, Thilo A1 - Schmidt, Marcus A1 - von Oheimb, Goddert A1 - Kriebitzsch, Wolf-Ulrich A1 - Ellenberg, Hermann T1 - Soil seed banks near rubbing trees indicate dispersal of plant species into forests by wild boar N2 - Current knowledge about processes that generate long-distance dispersal of plants is still limited despite its importance for persistence of populations and colonization of new potential habitats. Today wild large mammals are presumed to be important vectors for long-distance transport of diaspores within and between European temperate forest patches, and in particular wild boars recently came into focus. Here we use a specific habit of wild boar, i.e. wallowing in mud and subsequent rubbing against trees, to evaluate epizoic dispersal of vascular plant diaspores. We present soil seed bank data from 27 rubbing trees versus 27 control trees from seven forest areas in Germany. The mean number of viable seeds and the plant species number were higher in soil samples near rubbing trees compared with control trees. Ten of the 20 most frequent species were more frequent, and many species exclusively appeared in the soil samples near rubbing trees. The large number of plant species and seeds – approximated > 1000 per tree – in the soils near rubbing trees is difficult to explain unless the majority were dispersed by wild boar. Hooked and bristly diaspores, i.e. those adapted to epizoochory, were more frequent, above that many species with unspecialised diaspores occurred exclusively near rubbing trees. Different to plant species closely tied to forest species which occur both in forest and open vegetation, and non-forest species were more frequent near rubbing trees compared with controls. These findings are consistent with previous studies on diaspore loads in the coats and hooves of shot wild boars. However, our method allows to identify the transport of diaspores from the open landscape into forest stands where they might especially emerge after disturbance, and a clustered distribution of epizoochorically dispersed seeds. Moreover, accumulation of seeds of wetness indicators near rubbing trees demonstrates directed dispersal of plant species inhabiting wet places between remote wallows. N2 - Das aktuelle Wissen über Prozesse, die zur Fernausbreitung von Pflanzen führen, ist trotz ihrer Bedeutung für das Überleben von Populationen und die Besiedlung neuer potenzieller Habitate noch immer sehr begrenzt. Wildlebende Großsäuger sind heutzutage vermutlich wichtige Vektoren für den Ferntransport von Diasporen innerhalb und zwischen den einzelnen Waldflächen in Mitteleuropa, und speziell das Wildschwein (Sus scrofa L.) spielt dabei offenbar eine herausragende Rolle. Wir nutzen hier ein spezifisches Verhalten des Wildschweins – Suhlen im Schlamm und nachfolgendes Scheuern an sogenannten Malbäumen – um die epizoochore Ausbreitung von Gefäßpflanzen-Diasporen einzuschätzen. Dargestellt werden die Ergebnisse von Samenbank-Untersuchungen von 27 Malbäumen im Vergleich zu 27 Kontrollbäumen aus sieben Waldgebieten in Deutschland. Sowohl die mittlere Zahl lebensfähiger Samen als auch die Artenzahl waren höher in Bodenproben neben Malbäumen. Zehn der 20 in der Samenbank verbreitetsten Pflanzenarten hatten hier ihren Schwerpunkt, und viele Arten kamen ausschließlich in den neben Malbäumen gewonnenen Proben vor. Die große Zahl von Pflanzenarten und Samen – zumindest > 1000 pro Baum – im Boden an Malbäumen lässt sich nur durch die Aktivität der Wildschweine erklären. Mit Haken oder Borsten ausgestattete, d.h. an Epizoochorie angepasste Diasporen waren häufiger, aber auch viele Arten mit unspezialisierten Diasporen kamen ausschließlich in der Samenbank bei Malbäumen vor. Anders als weitgehend an Wald gebundene Pflanzenarten waren solche, die sowohl im Wald und im Offenland vorkommen, sowie nicht im Wald vorkommende Arten häufiger neben Malbäumen als neben Kontrollbäumen. Diese Befunde stimmen mit denen früherer Untersuchungen von Diasporenladungen im Fell und in den Hufen geschossener Wildschweine überein. Unsere Methode erlaubt darüber hinaus aber die Identifizierung des Diasporentransports aus dem Offenland in die Waldbestände, wo sie insbesondere nach Störungen keimen dürften, sowie einer ungleichmäßigen Verteilung epizoochor ausgebreiteter Diasporen. Außerdem zeigt die Akkumulation von Samen von Nässezeigern neben den Malbäumen eine gezielte Ausbreitung nasse Standorte bewohnender Pflanzenarten zwischen entfernt gelegenen Suhlen. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 150 KW - Diaspore morphology KW - directed dispersal KW - epizoochory KW - long-distance dispersal KW - Sus scrofa Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46476 ER - TY - GEN A1 - Jorgensen, Knud Erik T1 - Three doctrines on European foreign policy N2 - Taking its departure from the debate on the Iraq war, the article examines three so-called „doctrines“ on European foreign policy. According to the first one, there is no such thing as an EU foreign policy. This may come as a surprise for policy-makers but is a common view among media commentators, analysts and some diplomats. The second doctrine holds that the EU’s foreign policy has been, is, and always will be a failure. Reasons for this gloomy view show considerable variations and are most likely unsustainable in the long run. The third approach is more optimistic, counting on the EU’s material volume, yet often ignoring the need to politically cash in if international clout is the quest. T2 - Drei Doktrinen zur europäischen Außenpolitik KW - Europäische Union KW - Außenpolitik KW - European Union KW - European Foreign Policy Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-46318 ER - TY - GEN A1 - Hespeling, Ursula A1 - Püschel, Gerhard Paul A1 - Jungermann, Kurt A1 - Götze, Otto A1 - Zwirner, Jörg T1 - Stimulation of glycogen phosphorylase in rat hepatocytes via prostanoid release from Kupffer cells by recombinant rat anaphylatoxin C5a but not by native human C5a in hepatocyte/Kupffer cell co-cultures N2 - Human anaphylatoxin C3a had previously been shown to increase glycogenolysis in perfused rat liver and prostanoid formation in rat liver macrophages. Surprisingly, human C5a, which in other systems elicited stronger responses than C3a, did not increase glycogenolysis in perfused rat liver. Species incompatibilities within the experimental system had been supposed to be the reason. The current study supports this hypothesis: (1) In rat liver macrophages that had been maintained in primary culture for 72 h recombinant rat anaphylatoxin C5a in concentrations between 0.1 and 10 pg/ml increased the formation of thromboxane A₂, prostaglandin D₂, E₂ and F₂α6- to 12-fold over basal within 10 min. In contrast, human anaphylatoxin C5a did not increase prostanoid formation in rat Kupffer cells. (2) The increase in prostanoid formation by recombinant rat C5a was specific. It was inhibited by a neutralizing monoclonal antibody. (3) In co-cultures of rat hepatocytes and rat Kupffer cells but not in hepatocyte mono-cultures recombinant rat C5a increased glycogen phosphorylase activity 3-fold over basal. This effect was inhibited by incubation of the co-cultures with 500 μM acetylsalicyclic acid. Thus, C5a generated either locally in the liver or systemically e.g. in the course of sepsis, may increase hepatic glycogenolysis by a prostanoid-mediated intercellular communication between Kupffer cells and hepatocytes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 117 Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45909 ER - TY - GEN A1 - Muschol, Waldemar A1 - Püschel, Gerhard Paul A1 - Hülsmann, Martina A1 - Jungermann, Kurt T1 - Eicosanoid-mediated increase in glucose and lactate output as well as decrease and redistribution of flow by complement-activated rat serum in perfused rat liver N2 - Rat serum, in which the complement sytem had been activated by incubation with zymosan, increased the glucose and lactate output, and reduced and redistributed the flow in isolated perfused rat liver clearly more than the control serum. Heat inactivation of the rat serum prior to zymosan incubation abolished this difference. Metabolic and hemodynamic alterations caused by the activated serum were dose dependent. They were almost completely inhibited by the cyclooxygenase inhibitor indomethacin and by the thromboxane antagonist 4-[2-(4-chlorobenzenesulfonamide)-ethyl]-benzene-acetica cid (BM 13505), but clearly less efficiently by the 5’-lipoxygenase inhibitor nordihydroguaiaretic acid and the leukotriene antagonist N-{3-[3-(4-acetyl-3-hydroxy-2-propyl-phenoxy)-propoxy]-4-chlorine-6-methyl-phenyl}-1H-tetrazole-5-carboxamide sodium salt (CGP 35949 B). Control serum and to a much larger extent complement-activated serum, caused an overflow of thromboxane B₂ and prostaglandin F₂α into the hepatic vein. It is concluded that the activated complement system of rat serum can influence liver metabolism and hemodynamics via release from nonparenchymal liver cells of thromboxane and prostaglandins, the latter of which can in turn act on the parenchymal cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - pape 116 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45892 ER - TY - GEN A1 - Püschel, Gerhard Paul A1 - Miura, Hisayuki A1 - Neuschäfer-Rube, Frank A1 - Jungermann, Kurt T1 - Inhibition by the protein kinase C activator 4β-phorbol 12-myristate 13-acetate of the prostaglandin F₂α-mediated and noradrenaline-mediated but not glucagon-mediated activation of glycogenolysis in rat liver N2 - In perfused rat livers, infusion of prostaglandin F₂α (PGF₂α) or noradrenaline increased glucose and lactate output and reduced flow. Glucagon increased glucose output and decreased lactate output without influence on flow. Infusion of phorbol 13-myristate 14-acetate (PMA) for 20 min prior to these stimuli strongly inhibited the metabolic and hemodynamic effects of noradrenaline, reduced the metabolic actions of PGF₂α but did not alter the effects of glucagon. In isolated rat hepatocytes PGF₂α, noradrenaline and glucagon activated glycogen phosphorylase but only PGF₂α and noradrenaline increased intracellular inositol 1,4,5-1risphosphalc (InsP₃). The noradrenaline- or PGF₂α-elicited activation of glycogen phosphorylase and increase in InsP₃ were largely reduced after preincubation of the cells for 10 min with PMA, whereas the glucagon-mediated enzyme activation was not affected. In contra\t to PMA, the phorbol ester 4a-phorbol 13,14-didecanoate. which does not activate protein kinase C, did not attenuate the PGF₂α- and noradrenaline-elicited stimulation of glucose output, glycogen phosphorylase and InsP, formation. Stimulation of InsP₃ formation by AlF₄⁻, which activates phospholipase C independently of the receptor, was not attenuated by prior incubation with PMA. Plasma membranes purified from isolated hepatocytes had both a high-capacity, low-affinity and a low-capacity, high-affinity binding site for PGF₂α. The Kd of the high-capacity, low-affinity binding site was close to the concentration of PGF₂α that increased glycogen phosphorylase activity halfmaximally. Binding to the high-capacity, low-affinity binding site was enhanced by guanosine 5'- 0-(3-thio)triphosphate (GTP[S]). This high-capacity, low-affinity site might thus represent the receptor. The Bmax and Kd of the high-capacity site, as well as the enhancement by GTP[S] of PGF₂α binding to this site, remained unaffected by PMA pretreatment. It is concluded that, in hepatocytes, activation of protein kinase C by PMA interrupted the InsP₃-mediated signal pathway from PGF₂α via a PGF₂α receptor and phospholipase C to glycogen phosphorylase at a point distal of the receptor prior to phospholipase C. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 115 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45889 ER - TY - GEN A1 - Püschel, Gerhard Paul A1 - Mentlein, Rolf A1 - Heymann, Eberhard T1 - Isolation and characterization of Dipeptidyl Peptidase IV from human placenta N2 - Human placenta is surprisingly rich in post-proline dipeptidyl peptidase activity. Among various cell fractions, microsomes have the highest specific activity. A homogeneous enzyme preparation is obtained in a six-step purification procedure. The final preparation appears homogeneous upon dodecyl sulfate electrophoresis, but analytical isoelectric focussing reveals various active bands with isoelectric points in the range of pH 3 - 4. The enzyme is a glycoprotein containing about 30% carbohydrate. Treatment with neuraminidase lowers the isoelectric points but does not reduce the heterogeneity of the band pattern. The subunit molecular weight is 120000 as estimated by dodecyl sulfate electrophoresis, whereas Mr of the native enzyme is > 200000, as can be concluded from gel filtration experiments. The purified dipeptidyl peptidase cleaves various synthetic and natural peptides, including substance P, kentsin, casomorphin and a synthetic renin inhibitor. In general, the specificity of the placenta peptidase is similar to that of post-proline dipeptidyl peptidase from other sources. Phenylalanylprolyl-P-naphthylamide (Km = 0.02 mM, I/ = 92 Ujmg) is the best substrate among various synthetic peptide derivatives. Only peptides with a free N-terminal amino group and proline, hydroxyproline, or alanine in position 2 of the N-terminal sequence are cieaved. However, X-Pro-Pro- . . . structures, e. g. as in bradykinin, are not attacked. 1 mM bis-(6nitrophenyI)phosphate or 1 mM diisopropylfluorophosphate completely inactivate the peptidase within 30 min at 30°C (pH 8). The peptidase is also completely inhibited by 1 mM Zn²⁺ and by other heavy metals. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 114 Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45875 ER - TY - GEN A1 - Neuschäfer-Rube, Frank A1 - Püschel, Gerhard Paul A1 - Jungermann, Kurt T1 - Characterization of prostaglandin-F₂α-binding sites on rat hepatocyte plasma membranes N2 - Prostaglandin (PG)F₂α has previously been shown to increase glucose output from perfused livers and isolated hepatocytes, where it stimulated glycogen phosphorylase via an inositol-trisphosphatedependent signal pathway. In this study, PGF₂α binding sites on hepatocyte plasma membranes, that might represent the putative receptor, were characterized. Binding studies could not be performed with intact hepatocytes, because PGF₂α accumulated within the cells even at 4°C. The intracellular accumulation was an order of magnitude higher than binding to plasma membranes. Purified hepatocyte plasma membranes had a high-affinity/low-capacity and a low-affinity/highcapacity binding'site for PGF₂α. The respective binding constants for the high-affinity site were Kd = 3 nM and Bmax = 6 fmol/mg membrane protein, and for the low-affinity site Kd = 426 nM and Bmax = 245 fmol/mg membrane protein. Specific PGF₂α binding to the low-affinity site, but not to the high-affinity site, could be enhanced most potently by GTP[γS] followed by GDP[ϐS] and GTP, but not by ATP[γS] or GMP. PGF₂α competed most potently with [³H]PGF₂α for specific binding to hepatocyte plasma membranes, followed by PGD₂ and PGE₂. Since the low-affinity PGF₂α-binding site had a Kd in the concentration range in which PG had previously been shown to be half-maximally active, and since this binding site showed a sensitivity to GTP, it is concluded that it might represent the receptor involved in the PGF₂α signal chain in hepatocytes. A biological function of the high-affinity site is currently not known. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 113 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45863 ER - TY - GEN A1 - Püschel, Gerhard Paul A1 - Kirchner, C. A1 - Schröder, A. A1 - Jungermann, Kurt T1 - Glycogenolytic and antiglycogenolytic prostaglandin E₂ actions in rat hepatocytes are mediated via different signalling pathways N2 - Prostaglandin E₂ has been reported both to stimulate glycogen-phosphorylase activity (glycogenolytic effect) and to inhibit the glucagon-stimulated glycogen-phosphorylase activity (antiglycogenolytic effect) in rat hepatocytes. It was the purpose of this study to resolve this apparent contradiction and to characterize the signalling pathways and receptor subtypes involved in the opposing prostaglandin E₂ actions. Prostaglandin E₂ (10 μM) increased glucose output, glycogen-phosphorylase activity and inositol trisphosphate formation in hepatocyte cell culture andor suspension. In the same systems, prostaglandin E₂ decreased the glucagon-stimulated (1 nM) glycogen-phosphorylase activity and cAMP formation. The signalling pathway leading to the glycogenolytic effect of PGE₂ was interrupted by incubation of the hepatocytes with 4P-phorbol 12-myristate 13-acetate (100 nM) for 10 min, while the antiglycogenolytic effect of prostaglandin E₂ was not attenuated. The signalling pathway leading to the antiglycogenolytic effect of prostaglandin E₂ was interrupted by an incubation of cultured hepatocytes with pertussis toxin (100 ng/ml) for 18 h, whereas the glycogenolytic effect of prostaglandin E₂ was enhanced. The EP₁/EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Sulproston had a stronger glycogenolytic potency than the EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Misoprostol. The antiglycogenolytic potency of both agonists was equal. It is concluded that the glycogenolytic and the antiglycogenolytic effects of prostaglandin E₂ are mediated via different signalling pathways in hepatocytes possibly involving EP₁ and EP₃ prostaglandin E₂ receptors, respectively. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 112 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45853 ER - TY - GEN A1 - Püschel, Gerhard Paul A1 - Jungermann, Kurt T1 - Activation of inositol phosphate formation by circulating noradrenaline but not by sympathetic nerve stimulation with a similar increase of glucose release in perfused rat liver N2 - In the isolated rat liver perfused in situ, stimulation of the nerve bundles around the hepatic artery and portal vein caused an increase of glucose and lactate output and a reduction of perfusion flow. These changes could be inhibited completely by α-receptor blockers. The possible involvement of inositol phosphates in the intracellular signal transmission was studied. 1. In cell-suspension experiments, which were performed as a positive control, noradrenaline caused an increase in glucose output and, in the presence of 10 mM LiCl, a dose-dependent and time-dependent increase of inositol mono, bis and trisphosphate. 2. In the perfused rat liver 1 μM noradrenaline caused an increase of glucose and lactate output and in the presence of 10 mM LiCl a time-dependent increase of inositol mono, bis and trisphosphate that was comparable to that observed in cell suspensions. 3. In the perfused rat liver stimulation of the nerve bundles around the portal vein and hepatic artery caused a similar increase in glucose and lactate output to that produced by noradrenaline, but in the presence of 10 mM LiCl there was a smaller increase of inositol monophosphate and no increase of inositol bis and trisphosphate. These findings are in line with the proposal that circulating noradrenaline reaches every hepatocyte, causing a clear overall increase of inositol phosphate formation and thus calcium release from the endoplasmic reticulum, while the hepatic nerves reach only a few cells causing there a small local change of inositol phosphate metabolism and thence a propagation of the signal via gap junctions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 110 Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45846 ER - TY - GEN A1 - Neuschäfer-Rube, Frank A1 - DeVries, Christa A1 - Hänecke, Kristina A1 - Jungermann, Kurt A1 - Püschel, Gerhard Paul T1 - Molecular cloning and expression of a prostaglandin E₂ receptor of the EP₃ϐ subtype from rat hepatocytes N2 - Rat hepatocytes have previously been reported to possess prostaglandin E₂ receptors of the EP₃-type (EP₃-receptors) that inhibit glucagonstimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP₃ϐ receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95% homology to the EP₃ϐ receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE₂ with an apparent Kd of 15 nM. PGE₂ > PGF₂α > PGD₂ competed for [³H]PGE₂ binding sites as did the EP₃ receptor agonists M&B 28767 = sulprostone > misoprostol but not the EP₁ receptor antagonist SC 19220. In stably transfected CHO cells M&B 28767 > sulprostone = PGE₂ > misoprostol > PGF₂α inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP₃ϐ receptor of rat hepatocytes closely resemble those of the EP₃ϐ receptor of mouse mastocytoma. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 108 KW - Prostaglandin receptor KW - Hepatocyte (rat) KW - Molecular cloning and expression Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45830 ER - TY - GEN A1 - Püschel, Gerhard Paul A1 - Christ, Bruno T1 - Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes N2 - In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 045 KW - Prostaglandin E₂ KW - Glucagon KW - Phosphoenolpyruvate carboxykinase KW - Inflammation KW - mRNA degradation Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45792 ER - TY - GEN A1 - Dortay, Hakan A1 - Müller-Röber, Bernd T1 - A highly efficient pipeline for protein expression in Leishmania tarentolae sing infrared fluorescence protein as marker N2 - Background: Leishmania tarentolae, a unicellular eukaryotic protozoan, has been established as a novel host for recombinant protein production in recent years. Current protocols for protein expression in Leishmania are, however, time consuming and require extensive lab work in order to identify well-expressing cell lines. Here we established an alternative protein expression work-flow that employs recently engineered infrared fluorescence protein (IFP) as a suitable and easy-to-handle reporter protein for recombinant protein expression in Leishmania. As model proteins we tested three proteins from the plant Arabidopsis thaliana, including a NAC and a type-B ARR transcription factor. Results: IFP and IFP fusion proteins were expressed in Leishmania and rapidly detected in cells by deconvolution microscopy and in culture by infrared imaging of 96-well microtiter plates using small cell culture volumes (2 μL - 100 μL). Motility, shape and growth of Leishmania cells were not impaired by intracellular accumulation of IFP. In-cell detection of IFP and IFP fusion proteins was straightforward already at the beginning of the expression pipeline and thus allowed early pre-selection of well-expressing Leishmania clones. Furthermore, IFP fusion proteins retained infrared fluorescence after electrophoresis in denaturing SDS-polyacrylamide gels, allowing direct in-gel detection without the need to disassemble cast protein gels. Thus, parameters for scaling up protein production and streamlining purification routes can be easily optimized when employing IFP as reporter. Conclusions: Using IFP as biosensor we devised a protocol for rapid and convenient protein expression in Leishmania tarentolae. Our expression pipeline is superior to previously established methods in that it significantly reduces the hands-on-time and work load required for identifying well-expressing clones, refining protein production parameters and establishing purification protocols. The facile in-cell and in-gel detection tools built on IFP make Leishmania amenable for high-throughput expression of proteins from plant and animal sources. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 122 KW - System KW - Donovani Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44773 ER - TY - GEN A1 - Selting, Margret T1 - Speech style in conversation as an interactive achievement N2 - Content: 1. Introduction 2. The notion of speech style: from a dependent variable to contextualization cue 3. Speech styles in conversation from a German Sozialamt 3.1 Extracts from conversation 3.2 Speech style constituting cues 3.3 Choice and alternation of speech styles in conversation 4. Summary and conclusions T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 67 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-43189 ER - TY - GEN A1 - Selting, Margret T1 - Question intonation revisited : the intonation of conversational questions N2 - Content: 1. Introduction 2. Aim and approach of the present analysis 3. Non-restrictive 'open' conversational questions 4. More restrictive "narrower" questions 5. "Deviant cases" 6. Conclusions T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 66 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-43179 ER - TY - GEN A1 - Tsukamoto, Junko A1 - Heabel, Sophie A1 - Valenca, Gustavo P. A1 - Peter, Martin A1 - Franco, Telma T1 - Enzymatic direct synthesis of acrylic acid esters of mono- and disaccharides N2 - BACKGROUND: There is an increased need to replace materials derived from fossil sources by renewables. Sugar-cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the preparation of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous preparation of protected sugar derivatives, such as glycosides, or activated acrylates, such as vinyl acrylate. RESULTS: Lipase catalyzed esterification of three mono- and two disaccharides with acrylic acid, in the presence or absence of molecular sieves was investigated. The reactions were monitored by high-performance liquid chromatography (HPLC) and the products were analyzed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. The main products are mono- and diacrylates, while higher esters are formed as minor products. The highest conversion to sugar acrylates was observed for the D-glucose and D-fructose, followed by D-xylose and D-maltose. Molecular sieves had no pronounced effect on the conversion CONCLUSIONS: A feasible method is described to produce and to characterize sugar acrylates, including those containing more than two acrylate groups. The process for production of these higher esters could potentially be optimized further to produce molecules for cross-linking in acrylate polymerization and other applications. The direct enzymatic esterification of free carbohydrates with acrylic acid is unprecedented. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 106 KW - carbohydrate esters KW - enzymatic esterification KW - acrylic acid esters KW - MALDI-TOF mass spectrometry Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42652 ER - TY - GEN A1 - Oliveira Jr, E. N. A1 - Gueddari, Nour E. El A1 - Moerschbacher, Bruno M. A1 - Peter, Martin A1 - Franco, Telma T1 - Growth of phytopathogenic fungi in the presence of partially acetylated chitooligosaccharides N2 - Four phytopathogenic fungi were cultivated up to six days in media containing chitooligosaccharide mixtures differing in average DP and FA. The three different mixtures were named Q3 (which contained oligosaccharides ofDP2–DP10, withDP2–DP7 asmain components), Q2 (which contained oligosaccharides of DP2–DP12, with DP2–DP10 as main components) and Q1 (which derived from Q2 and contained oligomers of DP5–DP8 with hexamer and a heptamer as the main components). The novel aspect of this work is the description of the effect of mixtures of oligosaccharides with different and known composition on fungal growth rates. The growth rate of Alternaria alternata and Rhizopus stolonifer was initially inhibited by Q3 and Q2 at higher concentrations. Q1 had a growth stimulating effect on these two fungi. Growth of Botrytis cinerea was inhibited by Q3 and Q2, while Q1 had no effect on the growth of this fungus. Growth of Penicillium expansum was only slightly inhibited by higher concentrations of sample Q3, while Q2 and Q1 had no effect. The inhibition of growth rates or their resistance toward chitooligosaccharides correlated with the absence or presence of chitinolytic enzymes in the culture media, respectively. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 105 KW - Chitosan KW - Chitinase KW - Fungi KW - Oligosaccharides KW - Phytopathogens Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42646 ER - TY - GEN A1 - Bringmann, Gerhard A1 - Mutanyatta-Comar, Joan A1 - Maksimenka, Katja A1 - Wanjohi, John M. A1 - Heydenreich, Matthias A1 - Brun, Reto A1 - Müller, Werner E. G. A1 - Peter, Martin A1 - Midiwo, Jacob O. A1 - Yenesew, Abiy T1 - Joziknipholones A and B : the First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens N2 - From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 104 KW - antimalarial activity KW - chirality KW - joziknipholones KW - natural products KW - structure elucidation Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42638 ER - TY - GEN A1 - Henkel, Carsten A1 - Courtois, Jean-Yves A1 - Kaiser, Robin A1 - Westbrook, C. A1 - Aspect, Alain T1 - Phase shifts of atomic de Broglie waves at an evanescent wave mirror N2 - A detailed theoretical investigation of the reflection of an atomic de Broglie wave at an evanescent wave mirror is presented. The classical and the semiclassical descriptions of the reflection process are reviewed, and a full wave-mechanical approach based on the analytical soution of the corresponding Schrödinger equation is presented. The phase shift at reflection is calculated exactly and interpreted in terms of instantaneous reflection of the atom at an effective mirror. Besides the semiclassical regime of reflection describable by the WKB method, a pure quantum regime of reflection is identified in the limit where the incident de Broglie wavelength is large compared to the evanescent wave decay length. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 103 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42289 ER - TY - GEN A1 - Henkel, Carsten A1 - Steane, Andrew M. A1 - Kaiser, Robin A1 - Dalibard, Jean T1 - A modulated mirror for atomic interferometry N2 - A novel atomic beam splitter, using reflection of atoms off an evanescent light wave, is investigated theoretically. The intensity or frequency of the light is modulated in order to create sidebands on the reflected de Broglie wave. The weights and phases of the various sidevands are calculated using three different approaches: the Born approximation, a semiclassical path integral approach, and a numerical solution of the time-dependent Schrdinger equation. We show how this modulated mirror could be used to build practical atomic interferometers. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 102 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42279 ER - TY - GEN A1 - Henkel, Carsten A1 - Courtois, Jean-Yves A1 - Aspect, Alain T1 - Atomic diffraction by a thin phase grating N2 - We present a semiclassical perturbation method for the description of atomic diffraction by a weakly modulated potential. It proceeds in a way similar to the treatment of light diffraction by a thin phase grating, and consists in calculating the atomic wavefunction by means of action integrals along the classical trajectories of the atoms in the absence of the modulated part of the potential. The capabilities and the validity condition of the method are illustrated on the well-known case of atomic diffraction by a Gaussian standing wave. We prove that in this situation the perturbation method is equivalent to the Raman-Nath approximation, and we point out that the usually-considered Raman-Nath validity condition can lead to inaccuracies in the evaluation of the phases of the diffraction amplitudes. The method is also applied to the case of an evanescent wave reflection grating, and an analytical expression for the diffraction pattern at any incidence angle is obtained for the first time. Finally, the application of the method to other situations is briefly discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 101 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42269 ER - TY - GEN A1 - Selting, Margret T1 - The role of intonation in the organization of repair and problem handling sequences in conversation N2 - Transcripts of repair and/or problem handling sequences from natural conversations are presented and analyzed with special reference to the role of intonation in the interactive organization of these sequences. It is shown that (a) in the initiation of so-called repair or local problem handling sequences, intonation is used as a type-distinctive device, and (b) in the handling of a global problem handling sequence, intonation is systematically used as a means to constitute and control participant cooperation. In general, intonation is analyzed as one contextualization cue cooccurring with specific syntactic, semantic and discourse organizational devices to signal the status of an utterance in conversational context. It is hypothesized that especially in the global problem handling sequence, different categories of intonation, i.e. different accent and contour types, are systematically used to signal and control participants' interactive problem handling in different, indexically relevant ways simultaneously. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 54 Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41992 ER - TY - GEN A1 - Selting, Margret T1 - Descriptive categories for the auditive analysis of intonation in conversation N2 - A system of descriptive categories for the notation and analysis of intonation in natural conversation is presented and discussed in relation to other systems currently suggested for incorporation in discourse analysis, The categories are based on purely auditive criteria. They differ from e.g. tonetic approaches by relying more on transcribers' and analysts' perception of the form and internal cohesiveness of contours, especially with respect to rhythmicality and/or pitch contour (gestalt). Intonation is conceived of as a relational phenomenon; the role of intonation in conversational utterances can only be analyzed by considering its co-occurrence with other properties of utterances like syntactic, semantic and discourse organizational structures and devices. In general, intonation is viewed as one signalling system contributing to the contextualization of utterances in their conversational context. A broad functional differentiation between different types of intonation categories seems plausible: Local categories like accents might fulfill mainly semantic functions, while global categories like different contour types might fulfill primarily functions with respect to the interactive coordination of activities in conversation. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 53 Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41986 ER - TY - GEN A1 - Selting, Margret T1 - Intonation as a contextualization device : case studies on the role of prosody, especially intonation, in contextualizing story telling in conversation N2 - Content: 1. Introduction 2. Premisses and descriptive categories 3. A first example 4. A second example 4.1. The internal structure of the story 4.2. The embedding of the story into the surrounding conversation 4.3. Some other relations within the sequence 5. Conclusions T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 45 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41903 ER - TY - GEN A1 - Selting, Margret T1 - Emphatic speech style : with special focus on the prosodic signalling of heightened emotive involvement in conservation N2 - After a review of previous work on the prosody of emotional involvement, data extracts from natural conversations are analyzed in order to argue for the constitution of an 'emphatic (speech) style', which linguistic devices are used to signal heightened emotive involvement. Participants use prosodic cues, in co-occurrence with syntactic and lexical cues, to contextualize turn-constructional units as 'emphatic'. Only realizations of prosodic categories that are marked in relation to surrounding uses of these categories have the power to contextualize units as displaying 'more-than-normal involvement'. In the appropriate context, and in cooccurrence with syntactic and lexical cues and sequential position, the context-sensitive interpretation of this involvement is 'emphasis'. Prosodic marking is used in addition to various unmarked cues that signal and constitute different activity types in conversation. Emphatic style highlights and reinforms particular conversational activities, and makes certain types of recipient responses locally relevant. In particular, switches from non-emphatic to emphatic style are used to contextualize 'peaks of involvement' or 'climaxes' in story-telling. These are shown in the paper to be 'staged' by speakers and treated by recipients as marked activities calling for displays of alignment with respect to the matter at hand. Signals of emphasis are deployable as techniques for locally organizing demonstrations of shared understanding and participant reciprocity in conversational interaction. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 41 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-37933 ER - TY - GEN A1 - Selting, Margret T1 - Levels of style-shifting : exemplified in the interaction strategies of a moderator in a listener participation programme N2 - This paper investigates speech styles and style-shifting in the speech of the moderator of a German radio participation programme. Style-shifting is shown to affect several distinct linguistic levels: phonetic, morphophonemic, syntactic, and lexical. The functions of style-shifting are related both to the discourse context and the broader institutional context. Relying on listeners' co-occurrence expectations with respect to language use in contexts and exploiting listeners' evaluations of processes of speech convergence and divergence, the moderator uses stereotypic markers at different style levels in locally strategic functions in discourse. On the one hand, thematic development is controlled by reinforcing obligations on the addressee. On the other hand, global social reciprocity patterns are constituted and secured. Patterns of reciprocity vary with different types of addressees. The conversational analysis of language variation shows that variation is not only a quantitative correlate of regional, social and contextual parameters as predominantly conceived of in sociolinguistics. Language variation is furthermore used as a means to signal social and interactive meaning in conversations. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 40 Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41273 ER - TY - GEN A1 - Selting, Margret T1 - Prosody in conversational questions N2 - My analysis of question-word questions in conversational question-answer sequences results in the decomposition of the conversational question into three systems of constitutive cues, which signal and contextualize the particular activity type in conversational interaction: (1) syntactic structure, (2) semantic relation to prior turn, and (3) prosody. These components are used and combined by interlocutors to distinguish between different activity types which (4) sequentially implicate different types of answers by the recipient in the next turn. Prosody is only one cooccurring cue, but in some cases it is the only distinctive one. It is shown that prosody, and in particular intonation, cannot be determined or even systematically related to syntactic sentence structure type or other sentence-grammatical principles, as most former and current theories of intonation postulate. Instead, prosody is an independent, autonomous signalling system, which is used as a contextualization device for the constitution of interactively relevant activity types in conversation. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 38 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-36635 ER - TY - GEN A1 - Jacobi-Dittrich, Juliane T1 - The struggle for an identity BT - working-class autobigraphies by women in nineteenth-century germany N2 - Contents: - Clara Mueller-Jahnke - Adelheid Popp - Marie Wegrainer T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 176 Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32369 SP - 321 EP - 345 ER - TY - GEN A1 - Schäfer-Bung, Boris A1 - Nest, Mathias T1 - Correlated dynamics of electrons with reduced two-electron density matrices N2 - We present an approach to the correlated dynamics of many-electron systems. We show, that the twoelectron reduced density matrix (2RDM) can provide a suitable description of the real time evolution of a system. To achieve this, the hierarchy of equations of motion must be truncated in a practical way. Also, the computational effort, given that the 2RDM is represented by products of two-electron determinants, is discussed, and numerical model calculations are presented. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 100 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41774 SN - 1866-8372 ER - TY - GEN A1 - Baltes, Paul B. A1 - Kliegl, Reinhold T1 - On the dynamics between growth and decline in the aging of intelligence and memory N2 - Content: - Different Intellectual Abilities Age Differently - Cultural Change and Interindividual Variability in Aging - Cognitive Intervention Research on Plasticity in Old Age * Psychological Evidence * Brain-Physiological Evidence - Age Differences and Testing-the-Limits - Conclusions - Summary T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 171 Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41116 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Volbrecht, Vicki J. A1 - Werner, John S. T1 - Influences of variation in lenticular and macular pigmentation on dichromatic neutral points N2 - Protanopie, deuteranopic and tritanopic neutral points were computed by determining the wavelength of light that produced the same quantal-catch ratio in the photopigments as that produced by a broad-band light of specified color temperature (range: 2 800—6 600 K). The Vos-Walraven primaries were used as photopigment absorption spectra that were screened by varying densities of ocular (0.5—2.5 at 400 nm) and macular (0.0—1.0 at 460 nm) pigmentation. The computations were carried out in 1 nm steps for the wavelength range of 380 to 720 nm. Most of the empirically determined mean, neutral-point loci in the literature were predicted from these computations to within 1—2nm when average ocular and macular pigment densities were used. The neutral-point range associated with the extreme values of the prereceptoral screening pigments was up to 25 nm for protanopes and deuteranopes and up to 13 nm for tritanopes. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 170 Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41101 ER - TY - GEN A1 - Simon, Tony A1 - Cabrera, Angel A1 - Kliegl, Reinhold T1 - A new approach to the study of subitizing as distinct enumeration processing N2 - This paper presents a new methodology for examining the phenomenon of subitizing. Subjects were presented with a standard numerosity-detection task but for a range of presentation times to allow Task-Accuracy Functions to be computed for individual subjects. The data appear to show a continuous change in processing for numerosities from 2 to 5 when the data are aggregated across subjects. At the level of individual subjects, there appear to be qualitative shifts in enumeration processing after 3 or 4 objects. The approach used in this experiment may be used to test the claim that subitizing is a distinct enumeration process that can be used for small numbers of objects. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 168 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41083 ER - TY - GEN A1 - Olson, Richard K. A1 - Kliegl, Reinhold A1 - Davidson, Brian J. T1 - Dyslexic and normal readers' eye movements N2 - Dyslexic and normal readers' eye movements were compared while tracking a moving fixation point and in reading. Contrary to previous reports, the dyslexic and normal readers did not differ in their number of saccades, percentage of regressions, or stability of fixations in the tracking task. Thus, defective oculomotor control was not associated with or a causal factor in dyslexia, and the dyslexics' abnormal eye movements in reading must be related to differences in higher cognitive processes. However, individual differences in oculmotor efficiency, independent of reading ability, were found within both the dyslexic and normal groups, and these differences were correlated in reading and tracking tasks. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 167 Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41071 ER - TY - GEN A1 - Altenberger, Uwe T1 - Stress-induced natural transformation of ortho- to clinohypersthene in metagabbros of the Ivrea Zone, Northern Italy N2 - Orthopyroxenes of a high temperature protomylonite of the Ivrea Zone, Northern Italy show twin like polysynthetic lamellae parallel to {210} of the hypersthene host. The transformation is caused by plastic deformation under high metamorphic conditions which has resulted in dynamic recrystallization of pyroxene and plagioclase. The lamellae consist of clinohypersthene. The twin plane and the lamellar clino-orthoinversion of hypersthene due to natural deformation have not been described hitherto. N2 - Orthopyroxene aus hoch temperierten Protomyloniten der Ivrea-Zone, Nord Italien zeigen polysynthetische Lamellen parallel {210} des Wirtes. Ihr Erscheinungsbild entspricht Deformationszwillingen. Die Lamellen sind invertiert zu Klinohypersthen. Die Ortho-Klino-Transformation ist auf eine Hochtemperaturdeformation zurückzuführen, wie dies anhand der dynamischen Rekristallisation der Pyroxene und Plagioklase bewiesen werden kann. Weder die speziellen Verwachsungsflächen noch die Ortho-Klino-Inversion durch natürliche Deformation wurden bisher beschrieben. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 099 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40778 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Mayr, Ulrich A1 - Krampe, Ralf T1 - Time-accuracy functions for determining process and person differences : an application to cognitive aging N2 - A paradigm for the determination of time-accuracy functions (TAFs) for individual participants is introduced for two pairs of tasks differing in cognitive complexity, that is, word scanning vs cued recognition and figural scanning vs figural reasoning. TAFs can be used to test dissociations of cognitive processes beyond scale-related ambiguities of ordinal interactions. The approach is applied to examine the cognitive-aging hypothesis that a single slowing factor can account for interactions between adult age and cognitive task complexity. Twenty young and 20 old adults participated in 17 sessions. Presentation times required for 75, 87.5, and 100% accuracies were determined for each task with a variant of the psychophysical method of limits. Accuracy was fit by negatively accelerated functions of presentation time. State-trace analyses showed that different slowing factors are required for high- and low-complexity tasks. Relations to speed-accuracy and performance-resource functions are discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 166 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17101 ER - TY - GEN A1 - Kliegl, Reinhold T1 - From presentation time to processing time : a psychopchysics approach to episodic memory N2 - Manipulations of presentation time have a long history in research on the development of memory, with a number of paradoxical results deriving from methodological shortcomings as well as from insufficient theoretical specifications. After a look at some of the problems in earlier research, a psychophysics approach to investigate episodic memory functions is presented in which criterion-referenced manipulation of presentation time is used to estimate the effects of experimental manipulations and the effects of individual differences. Criterion'referenced presentation time (CRPT), defined as the time required to score at an a priori specified level of accuracy, is interpreted as a preliminary indicator of internal processing time. CRPTs are shown to be valid predictors of traditional measures of memory accuracy. Moreover, an extension of this psychophysics approach yields estimates of complete condition-specific timeaccuracy functions and of function-specific processing times (plus other parameters) for individual subjects. It is argued that both from a cognitive and a developmental perspective it is often advantageous to trade experimental equivalence in presentation times for functional equivalence in accuracy of performance; this applies not only to episodic memory processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 165 Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40438 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Mayr, Ulrich A1 - Krampe, R. T. T1 - Process dissociations in cognitive aging N2 - One undisputed finding of cognitive aging research is that the two main clusters of intellectual abilities, fluid and crystallized abilities, exhibit differential age-related trends. Healthy older adults perform less well than young adults on almost any task that requires fast responses or taps the fluid or mechanical aspects of intelligence; they show much less of a decline, if any at all, in tasks requiring the access of their crystallized knowledge (Baltes, 1987; Horn, 1970). These age-differential trends are the prototype of what we will refer to as a process dissociation. We will show how process dissociations can be established within the domain of fluid intelligence that pass more stringent tests than is customary in experimental research on cognitive aging. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 164 Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40428 ER - TY - GEN A1 - Mayr, Ulrich A1 - Kliegl, Reinhold T1 - Sequential and coordinative complexity : age-based processing limitations in figural transformations N2 - Dimensions of cognitive complexity in figural transformations were examined in the context of adult age differences. Sequential complexity was manipulated through figural transformations of single objects in a multiple-object array. Coordinative complexity was induced through spatial or nonspatial transformations of the entire array. Results confirmed the prediction that age-related slowing is larger in coordinative complexity than in sequential complexity conditions. The effect was stable across 8 sessions (Experiment 1), was obtained when age groups were equated in accuracy with criterion-referenced testing (Experiment 2), and was corroborated by age-differential probabilities of error types (Experiments 1 and 2). A model is proposed attributing age effects under coordinative complexity to 2 factors: (a) basic-level slowing and (b) time-consuming reiterations through the processing sequence due to age-related working memory failures. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 163 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40416 ER - TY - GEN A1 - Lindenberger, Ulman A1 - Mayr, Ulrich A1 - Kliegl, Reinhold T1 - Speed and intelligence in old age N2 - Past research suggests that age differences in measures of cognitive speed contribute to differences in intellectual functioning between young and old adults. To investigate whether speed also predicts age-related differences in intellectual performance beyond age 70 years, tests indicating 5 intellectual abilities—speed, reasoning, memory, knowledge, and fluency—were administered to a close-to-representative, age-stratified sample of old and very old adults. Age trends of all 5 abilities were well described by a negative linear function. The speed-mediated effect of age fully explained the relationship between age and both the common and the specific variance of the other 4 abilities. Results offer strong support for the speed hypothesis of old age cognitive decline but need to be qualified by further research on the reasons underlying age differences in measures of speed. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 162 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40402 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Lindenberger, Ulman T1 - Modeling intrusions and correct recall in episodic memory : adult age differences in encoding of list context N2 - A model for correct recall and intrusions in cued recall of word lists is introduced. Intrusions are false responses that were correct in an earlier list. The model assumes 3 exclusive states for memory traces after encoding: with a list tag (i.e., with information about list origin), without list tags, and missing. Across lists, a trace can lose its list tag or its content. For retrieval, an optimal strategy of response selection was assumed. Younger and older laboratory-trained mnemonists participated in 2 experiments in which recall of permutations of a single word list across a single set of cues was held constant with individually adjusted presentation times. With correct recall equated to younger adults, older adults were more susceptible to intrusions. Age differences were restricted to model parameters estimating the probability of generation of list tags. Alternative accounts of age differences in context memory are discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 161 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40397 ER - TY - GEN A1 - Lindenberger, Ulman A1 - Kliegl, Reinhold A1 - Bates, Paul B. T1 - Professional expertise does not eliminate age differences in imagery-based memory performance during adulthood N2 - Using a testing-the-limits paradigm, the authors investigated the modulation (attenuation) o f negative adult age differences in imagery-based memory performance as a function of professional expertise. Six older graphic designers, 6 normal older adults, 6 younger graphic design students, and 6 normal younger students participated in a 19-session program with a cued-recall variant of the Method of Loci. Older graphic designers attained higher levels o f mnemonic performance than normal older adults but were not able to reach younger adults' level of performance; a perfect separation of age groups was achieved. Spatial visualization was a good predictor of mnemonic performance. Results suggest that negative adult age differences in imagery-based memory are attenuated but not eliminated by the advantages associated with criterion-relevant ability (talent) and experience. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 160 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40384 ER - TY - GEN A1 - Baltes, Paul B. A1 - Kliegl, Reinhold T1 - Further testing of limits of cognitive plasticity : negative age differences in a mnemonic skill are robust N2 - Earlier testing-the-limits research on age differences in cognitive plasticity of a memory skill was extended by 18 additional assessment and training sessions to explore whether older adults were able to catch up with additional practice and improved training conditions. The focus was on the method of loci, which requires mental imagination to encode and retrieve lists of words from memory in serial order. Of the original 37 subjects, 35 (16 young, ranging from 20 to 30 years of age, and 19 older adults, ranging from 66 to 80 years of age) participated in the follow-up study. Older adults showed sizable performance deficits when compared with young adults and tested for limits of reserve capacity. The negative age difference was substantial, resistant to extensive practice, and applied to all subjects studied. The primary origin for this negative age difference may be a loss in the production and use of mental imagination for operations of the mind. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 159 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40373 ER - TY - GEN A1 - Dittmann-Kohli, Freya A1 - Lachmann, Margie E. A1 - Kliegl, Reinhold A1 - Baltes, Paul B. T1 - Effects of cognitive training and testing on intellectual efficacy beliefs in elderly adults N2 - Elderly adults (N = 116; average age = 73 years) were randomly assigned to one of four treatment groups varying in the amount of training and testing on fluid intelligence tests. They were compared before and after treatment on self-efficacy and utility beliefs for intelligence tests and everyday competence. Although both ability training and extended retest practice resulted in significant gains in objective test performance (Baltes, Kliegl, & Dittmann-Kohli, 1988), only ability training resulted in positive changes in self-efficacy. However, these changes were restricted to testrelated self-efficacy. Training had no impact on perceived utility or on everyday self-efficacy beliefs. Implications of the results are discussed with regard to interventions to increase intellectual self-efficacy in elderly persons. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 157 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40351 ER - TY - GEN A1 - Thompson, Laura A. A1 - Kliegl, Reinhold T1 - Adult age effects of plausibility on memory : the role of time constraints during encoding N2 - We investigated the role of training-induced knowledge Schemas and encoding time on adult age differences in recall. High-plausible (schema coherent) words were recalled better than lowplausible (schema discrepant) words in both age groups. This difference was larger for old-adults than for young adults for presentation times ranging from 3 s to 11 s per word. After equating participants in overall recall (i.e., at 50% correct) by dynamic adjustment of presentation time, old adults again showed a stronger plausibility effect than young adults when recall was above criterion. In a second experiment with self-paced encoding, old adults used more time than young adults only for low-plausible pairs, yet they still remembered fewer of them. In a third experiment, both age groups preferred to imagine high- rather than low-plausible words, but this effect was more pronounced in old adults. The results indicate that, compared with young adults, old adults find it particularly difficult to form elaborative mental images of schema-discrepant information under a wide variety of time constraints during encoding. Results are discussed in relation to explanations based on age-related mental slowing. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 156 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40347 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Smith, Jacqui A1 - Baltes, Paul B. T1 - On the locus and process of magnification of age differences during mnemonic training N2 - The focus of this study was on developmental reserve capacity in old age as revealed by testing-thelimits. We examined (a) the time course of training-related magnification of age differences in serial word recall and (b) predictability of training gains by pretest individual differences in cognitive abilities. In 20 sessions, young (n = 18) and old (n = 19) adults were taught to recall lists of 30 words using the Method of Loci. Age differences were magnified early in practice at long presentation times (20 s and 15 s per word) and later at 5 s per word. Regression of posttraining scores on various pretraining abilities revealed significant effects of digit symbol substitution. Also, consistent with the assumption of age-related decline in developmental reserve capacity, the unique variance in serial word recall associated with age group became more salient as the training unfolded. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 155 Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40336 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Smith, Jacqui A1 - Baltes, Paul B. T1 - Testing-the-limits and the study of adult age differences in cognitive plasticity of a mnemonic skill N2 - Investigated the range and limits of cognitive reserve capacity as a general approach to the understanding of age differences in cognitive functioning. Testing-the-limits is proposed as a research strategy, Data are reported from 2 training studies involving old (65 to 83 years old) and young adults (19 to 29 years old). The training, designed to engineer an expertise in serial word recall, involved instruction and practice in the Method of Loci. Substantial plasticity was evident in pretest to posttest comparisons. Participants raised their serial word recall several times above that of pretest baseline. Age-differential limits in reserve capacity were evident in amount of training gain but not in responses to conditions of increased test difficulty (speeded stimulus presentation). Group differences were magnified by the training to such a degree that age distributions barely overlapped at posttests. Testing-the-limits offers promise in terms of understanding the extent and nature of cognitive plasticity. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 153 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40311 ER -