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 - Schiefele, Ulrich T1 - The influence of topic interest, prior knowledge, and cognitive capabilities on text comprehension N2 - The present study investigated the influence of topic interest on the comprehension of texts. The primary goals of the study were as follows: (1) to formulate a new definition of the concept "topic interest", (2) to control for cognitive capabilities (intelligence, short-term memory) and prior knowledge, and(3) to assess different levels of comprehension. A total of 53 male students, majoring in computer science, took part in the study. Subjects were presented with a text on "Psychology of Emotion". Prior to reading the text, they were asked to indicate their level of interest in the topic. After reading the text, subjects were given a test of comprehension involving open-ended questions. The questions were designed to represent different levels of comprehension. The results show that the effect of topic interest on text comprehension is especially pronounced when a deeper level of understanding is required. Surprisingly, prior knowledge had no effect on the level of comprehension. Verbal intelligence, on the other hand, showed a clear effect on comprehension, especially in answering questions of simple knowledge. The effects of interest and verbal intelligence could be shown to be independent of one another. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 047 Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33472 ER - TY - GEN A1 - Krahé, Barbara T1 - Situation cognition and coherence in personality : an individual-centered approach N2 - This volume reexamines the long-standing controversy about consistency in personality from a social psychological perspective. Barabara Krahé reconsiders the concept of consistency in terms of the systematic coherence of situation cognition and behaviour across situations. In the first part of the volume she undertakes an examination of recent social psychological models of situation cognition for their ability to clarify the principles underlying the perception of situational similarities. She then advances an individual-centred methedology in which nomothetic hypotheses about cross-situational coherence are tested on the basis of idiogrphic measurement of situation cognition and behaviour. In the second part of the volume, a series of empirical studies is reported which apply the individual-centred framework to the analysis of cross-situational coherence in the domain of anxiety-provoking situations. These studies are distinctive in that they extend over several months and use free-response data; they are based on idiographic sampling; and they employ explicit theoretical models to capture the central features of situation perception. The results demonstrate the benefits of integrating idiographic and nomothetic research strategies and exploiting the advantages of both perspectives. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 055 KW - Persönlichkeitsentwicklung KW - Konsistenz KW - Persönlichkeit KW - Kognition KW - soziale Situation KW - self-developement KW - consistency KW - personality KW - cognition KW - social situation Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33554 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 - Peter, Martin G. A1 - Förster, Hans T1 - On the structure of Eumelanins : identification of constitutional patterns by solid-state NMR spectroscopy N2 - Aus dem Inhalt: Melanins are complex polyphenolic polymers. They are usually formed in nature by enzyme-catalyzed oxidative polymerization of o-diphenols. The deep black eumelanins, derived from Dopa 1 or dopamine 3, are distinguished from the yellow to brown phaeomelanins obtained from Dopa in the presence of cysteine. Characteristic of eumelanins are the indole units, which are formed from catecholamines by intramolecular addition of the amino groups to the oxidatively generated o-quinones. [...] T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 053 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17027 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 - Püschel, Gerhard Paul A1 - Oppermann, Martin A1 - Muschol, Waldemar A1 - Götze, Otto A1 - Jungermann, Kurt T1 - Increase of glucose and lactate output and decrease of flow by human anaphylatoxin C3a but not C5a in perfused rat liver N2 - The complement fragments C3a and C5a were purified from zymosan-activated human serum by column chromatographic procedures after the bulk of the proteins had been removed by acidic polyethylene glycol precipitation. In the isolated in situ perfused rat liver C3a increased glucose and lactate output and reduced flow. Its effects were enhanced in the presence of the carboxypeptidase inhibitor DL-mercaptomethyl-3-guanidinoethylthio-propanoic acid (MERGETPA) and abolished by preincubation of the anaphylatoxin with carboxypeptidase B or with Fab fragments of an anti-C3a monoclonal antibody. The C3a effects were partially inhibited by the thromboxane antagonist BM13505. C5a had no effect. It is concluded that locally but not systemically produced C3a may play an important role in the regulation of local metabolism and hemodynamics during inflammatory processes in the liver. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 039 KW - Hepatic glucose balance KW - Hepatic lactate balance KW - Hepatic hemodynamics KW - Complement system KW - Anaphylatoxin Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16733 ER - TY - GEN A1 - Erdelen, C. A1 - Laschewsky, André A1 - Ringsdorf, H. A1 - Schneider, J. A1 - Schuster, A. T1 - Thermal behaviour of polymeric Langmuir-Blodgett multilayers N2 - Langmuir-Blodgett multilayers of hydrocarbon and fluorocarbon polymers with hydrophilic spacer, lipid-polyelectrolyte complexes and mesogenic polymers have been prepared. The thermal behaviour of the multilayers was studied by small angle X-ray scattering, IR and UV—visible spectroscopy. Good thermal stabilities were found for the various classes of polymers. In addition, for both complexed multilayers and mesogenic polymer films, reorientation processes were observed. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 080 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17378 ER - TY - GEN A1 - Laschewsky, André T1 - Monolayers and Langmuir-Blodgett multilayers of discotic liquid crystals? N2 - Contents: 1. Discotic Liquid Crystals 2. Monolayers and Langmuir-Blodgett Multilayers 3. Theoretical Considerations on the Molecular Packing of Discotic LCs in Monolayers and Multilayers 4. Spreading Experiments with Discotic LCs 5. LB-Multilayers of Discotic LCs 6. Polymeric Discotic LCs 7. Summary T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 061 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17396 ER - TY - GEN A1 - Biddle, M. B. A1 - Rickert, S. E. A1 - Lando, J. B. A1 - Laschewsky, André T1 - The use of the Langmuir-Blodgett technique to obtain ultra-thin polar films N2 - The piezoelectric and pyroelectric properties of oriented films possessing dipole moments are increasingly being used in pressure, acoustic, thermal and optical devices. The performance of these devices in many applications may be enhanced by thin-film technology.The developing Langmuir-Blodgett thin-film deposition technique offers the opportunity to obtain highly oriented and uniform organic-based films in the 10–5000 nm thickness range. Special techniques must be used, however, to assemble these molecules in such a way as to result in polar multilayer films. Several possible deposition techniques are investigated, with one resulting in a polar and pyroelectric film about 50 nm thick. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 098 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17185 ER - TY - GEN A1 - Krahé, Barbara T1 - Faking personality profiles on a standard personality inventory N2 - A study is reported which investigates the fakeability of personality profiles as measured by a standard personality inventory, the Freiburger Persönlichkeitsinventar (FPI). Unlike previous studies investigating laypersons' ability to fake a global good or bad impression, the present study examined individuals' ability to fake a specific personality profile. Four groups of subjects were instructed to fake their FPI scores so as to present themselves as high vs low scorers on the "social orientation" dimension or high vs low scorers on the "achievement orientation" dimension. The results clearly demonstrate that subjects are successful in manipulating their scores on the critical dimensions according to instruction. Moreover, they also fake related scales in a way that corroborates the intended image of a person with a high (or low) achievement (or social) orientation. The overall pattern of results reveals that subjects were able to distort their responses in a way that reflects their intuitive understanding of the dimensional structure of the FPI. The implications of the present findings for the use of personality inventories as valid diagnostic instruments are discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 084 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-34486 ER - TY - GEN A1 - Eckes, Thomas A1 - Krahé, Barbara A1 - Six, Bernd T1 - Predicting behavior in natural settings : four field studies N2 - Content Basic Concepts and Applied Perspectives in Attitude-Behavior Research Searching for Medium-Range Models of Behavior Prediction Putting the Models to Test General Discussion References T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 072 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33862 ER - TY - GEN A1 - Krahé, Barbara A1 - Semin, Gün R. T1 - In search of explanations : a rejoinder to Borkenau N2 - The main points raised by Borkenau against our challenge of the 'intuitive psychometrics' view of personality judgements are discussed, in particular his example of the link between school grades and intelligence. It is argued that the semantic similarity interpretation advanced in our paper is more adequate and more parsimonious than explanations in terms of psychometric reasoning. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 071 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33859 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 - TY - GEN A1 - Baltes, Paul B. A1 - Sowarka, Doris A1 - Kliegl, Reinhold T1 - Cognitive training research on fluid intelligence in old age : what can older adults achieve by themselves? N2 - Cognitive research on the plasticity of fluid intelligence has demonstrated that older adults benefit markedly from guided practice in cognitive skills and problem-solving strategies. We examined to what degree older adults are capable by themselves of achieving similar practice gains, focusing on the fluid ability of figural relations. A sample of 72 healthy older adults was assigned randomly to three conditions: control, tutor-guided training, self-guided training. Training time and training materials were held constant for the two training conditions. Posttraining performances were analyzed using a transfer of training paradigm in terms of three indicators: correct responses, accuracy, and level of item difficulty. The training programs were effective and produced a significant but narrow band of within-ability transfer. However, there was no difference between the two training groups. Older adults were shown to be capable of producing gains by themselves that were comparable to those obtained following tutor-guided training in the nature of test-relevant cognitive skills. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 152 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40297 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 - 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 - Laschewsky, André A1 - Ringsdorf, H. T1 - Polymerization of amphiphilic dienes in Langmuir-Blodgett multilayers N2 - Amphiphilic derivatives of octadiene and docosadiene were investigated in monolayers and Langmuir-Blodgett multilayers, with respect to their self-organization and their polymerization behavior. All amphiphiles investigated form monolayers. However, only acid and alcohol derivatives were able to build up multilayers. Those multilayers are rapidly photopolymerized in the layers via a two-step process: Irradiation with long-wavelength UV light yields soluble polymers, whereas additional irradiation with sfiort-wavelength UV light produces insoluble and presumably cross-linked polymers. The reaction meclianism is discussed according to the polymer characterization by UV spectroscopy, small-angle X-ray scattering, NMR spectroscopy, and gel permeation chromatography. All multilayers undergo structural changes during the polymerization; substantial changes result in defects in the polymerized layers as observed by scanning electron microscopy. In contrast to the acids and alcohols, the deposition of monolayers of the aldehyde derivatives did not yield well-ordered multilayers, but rather amorphous films. In this different film structure, the photopolymerization process differs from the one observed in multilayers. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 058 Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17176 ER - TY - GEN A1 - Lupo, Donald A1 - Prass, Werner A1 - Scheunemann, Ude A1 - Laschewsky, André A1 - Ringsdorf, Helmut A1 - Ledoux, Isabelle T1 - Second-harmonic generation in Langmuir-Blodgett monolayers of stilbazium salt and phenylhydrazone dyes N2 - Contents: 1. INTRODUCTION 2. SYNTHESIS OF THE COMPOUNDS 3. PREPARATION AND CHARACTERIZATION OF MONOLAYERS A. Monolayer Isotherms B. Langmuir-Blodgett Monolayer Films 4. EXPERIMENTAL SETUP FOR NONLINEAR MEASUREMENTS 5. NONLINEAR OPTICAL PROPERTIES 6. DISCUSSION 7. CONCLUSION T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 094 Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17401 ER - TY - GEN A1 - Krahé, Barbara A1 - Semin, Gün R. T1 - Explaining perceived cross-situational consistency : intuitive psychometrics or semantic mediation? N2 - Recent studies at the interface of social cognition and personality theory have stressed lay persons' ability to 'function as intuitive psychometricians' (Epstein and Teraspulsky, 1986). This research argues that lay persons not only show a substantial degree of accuracy in estimating cross-situational generality of behaviour, but also take into account principles of aggregation over time. In contrast, it is argued here that lay persons' perceptions of the degree of relatedness of different behaviours are mediated largely by the decontextualized semantic relationships between behavioural descriptions. This argument finds support in two experimental studies which demonstrate that the main source for subjects' judgments of 'cross-situational consistency' can be found in an abstracted knowledge base which is represented and mediated through language. The implications of the findings are drawn out for personality research. in particular with reference to domain and item selection in questionnaires for research. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 070 Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33847 ER -