TY - GEN A1 - Anton, Peter A1 - Köberle, Peter A1 - Laschewsky, André T1 - Recent developments in the field of micellar polymers N2 - This article describes recent achievements in the field of micellar polymers, or polysoaps. Taking advantage of zwitterionic model polymers, systematic variations of the molecular architecture have provided an improved understanding of the relationship between the molecular structure of the polymers and their key properties such as surface activity and solubilization capacity. Useful rules are established, which take into account much of the previous data in the literature. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 090 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17263 ER - TY - GEN A1 - Anton, Peter A1 - Laschewsky, André T1 - Zwitterionic polysoaps with reduced density of surfactant side groups N2 - Several zwitterionic polymers were prepared by radical homopolymerization of surfactant monomers which bear diallyl, diene or vinylcyclopropane moieties. These polymer systems were complemented by alternating copolymers of appropriate zwitterionic vinyl compounds. Thus, polymers with reduced (as compared with simple vinylic homopolymers, or statistical copolymers) and well defined density of surfactant side groups are obtained. The solubilities found for these polymers are dominated by polymer geometry rather than by the balance of hydrophilic and hydrophobic fragments, thus corroborating a main-chain spacer model proposed recently. All water-soluble polymers exhibit characteristic features of classical polysoaps, as shown by surface tension measurements and by solubilization of hydrophobic dyes. In contrast, the water-insoluble copolymers are capable to form stable monolayers at the air-water interface. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 091 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17301 ER - TY - BOOK A1 - Battaglia Mayer, Alexandra A1 - Schmidt, Hans-Jürgen T1 - The de Sitter space-time as attractor solution in eighth order gravity T3 - Preprint / Universität Potsdam, Fachbereich Mathematik Y1 - 1993 VL - 1993, 05 PB - Univ. CY - Potsdam ER - TY - BOOK A1 - Baumgärtel, Hellmut T1 - Some operatoralgebraic fundamentals of the algebraic quantum field theory T3 - Preprint / Universität Potsdam, Fachbereich Mathematik Y1 - 1993 VL - 1993, 09 PB - Univ. CY - Potsdam ER - TY - JOUR A1 - Besnard, Philippe A1 - Schaub, Torsten H. T1 - A context-based framework for default logics Y1 - 1993 SN - 0-262-51071-5 ER - TY - JOUR A1 - Brunkhorst, Martin T1 - Sidney, Shakespeare, and the Contingencies of Performance Y1 - 1993 ER - TY - JOUR A1 - Damaschun, Gregor A1 - Damaschun, Hilde A1 - Gast, Klaus A1 - Misselwitz, Rolf A1 - Müller, Jürgen J. A1 - Pfeil, Wolfgang A1 - Zirwer, Dietrich T1 - Cold denaturation-induced conformational changes in phosphoglycerate kinase from yeast Y1 - 1993 ER - TY - GEN A1 - Elsenbeer, Helmut A1 - Cassel, Keith A1 - Tinner, W. T1 - A daily rainfall erosivity model for Western Amazonia N2 - Rainfall erosivities as defined by the R factor from the universal soil loss equation were determined for all events during a two-year period at the station La Cuenca in western Amazonia. Three methods based on a power relationship between rainfall amount and erosivity were then applied to estimate event and daily rainfall erosivities from the respective rainfall amounts. A test of the resulting regression equations against an independent data set proved all three methods equally adequate in predicting rainfall erosivity from daily rainfall amount. We recommend the Richardson model for testing in the Amazon Basin, and its use with the coefficient from La Cuenca in western Amazonia. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 050 KW - MESOSCALE CONVECTIVE COMPLEXES KW - KINETIC-ENERGY KW - UNITED-STATES KW - EROSION Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16962 ER - TY - JOUR A1 - Gienow, Wilfried T1 - Integrating change : perspectives in english language teaching Y1 - 1993 ER - TY - GEN A1 - Grözinger, Karl Erich T1 - The Buber-Scholem Controversy about Hasidic Tale and Hasidism - is there a solution? N2 - Excerpt: The shrill sounds of the now seemingly outdated controversy between Gershom Scholem and Martin Buber at the beginning of the sixties are still in the minds of every student of Hasidic literature and thought. - The "Scholem-community" feels content and the "Buber-community" upset. We can summarize the case in a few words. Martin Buber, the pioneer of Hasidism in the Western World, held the position that whoever would want to understand Hasidism had to turn to Hasidic tale as here, in the tales of the Hasidim, real Hasidic life was to be found. Whereas in the Hasidic homilies we meet mere non-creative tradition especially in the form of Kabbalah. Buber did not totally deny the importance of the Hasidic Midrash but he regarded it just as a commentary, i.e. as secondhand material, whereas, in his view, the tale was a true mirror of real Hasidic life [...] T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 15 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18673 ER - TY - GEN A1 - Grözinger, Karl Erich T1 - Handling of holy traditions as a path to mystical unity in the Kitve ha-‘Iyyun N2 - Excerpt: The writings from the thirteenth century called by Gershom Scholem the "Writings of the 'lyyun circle" are one of the most intriguing chapters of early kabbalah - this I need not to elaborate on as it is a well known fact to anyone whoever had read these texts or the literature about them. When reading these texts, one gets the impression as if the authors had at hand a box full of terms and phrases into which everybody could just stick his hand and take terms and phrases out of it in order to arrange them according to his own taste, disregarding the meaning they have in the writings of his fellow kabbalists. The result was, that we now have before us a large number of varying mosaic pictures in which we detect again and again the same mosaic pebbles, however composed differently. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 09 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18577 ER - TY - GEN A1 - Hatzichristou, Chyrse A1 - Hopf, Diether T1 - Students with learning disabilities : academic and psychosocial aspects of adaptation N2 - This study explores learning-disabled students' academic and psychosocial adjustment as compared to their non-disabled classmates within the mainstream public education system in Greece. A brief description of the special education services in Greece is also presented. The sample of the study consisted of fifth and sixth grade elementary school students in northern Greece. The learning-disabled students were identified based on teachers' evaluation (N=30). The control group consisted of all classmates of these students (N=307). Teacher-, peer and self-ratings were used and achievement data were obtained. The learning-disabled students were found to exhibit various academic and psychosocial difficulties based on the perceptions of all raters. Implications of the findings are discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 115 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16869 ER - TY - JOUR A1 - Haufe, G. A1 - Rolle, U. A1 - Kleinpeter, Erich A1 - Kivikoski, J. A1 - Rissanen, K. T1 - N-Heterocyclization in electrophilic haloamination reactions of 1,5-cyclooctadiene : formation of the granatanine and homotropane skeletons Y1 - 1993 ER - TY - JOUR A1 - Hubrig, Swetlana A1 - Mathys, Gautier T1 - Mass loss, magnetic field and chemical inhomogenities in the he-weak star HD 21699 Y1 - 1993 ER - TY - JOUR A1 - Jonas, Peter A1 - Langer, Heinz T1 - Selfadjoint extensions of a closed linear relation of defect one in a Krein space Y1 - 1993 ER - TY - JOUR A1 - Junek, Heinz T1 - Factorization of operator ideals and the BB-property Y1 - 1993 ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Thomas, Steffen A1 - Uhlig, G. A1 - Rudorf, Wolf-Dieter T1 - Study of the distribution of pi-Electrons in Push-Pull Alkenes by 1H an 13C NMR spectroscopy Y1 - 1993 ER - TY - JOUR A1 - Klettke, Cornelia T1 - Bibliographie critique Y1 - 1993 ER - TY - JOUR A1 - Kleßmann, Christoph T1 - The burden of the past in the two German states Y1 - 1993 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 - JOUR A1 - Kliegl, Reinhold A1 - Lindenberger, Ulman T1 - Modeling intrusions and correct recall in episodic memory : adult age differences in encoding of list context Y1 - 1993 ER - TY - GEN A1 - Krapp, Andreas A1 - Schiefele, Ulrich A1 - Schreyer, Inge T1 - Metaanalyse des Zusammenhangs von Interesse und schulischer Leistung N2 - Der Artikel berichtet von den Ergebnissen einer Metaanalyse des Zusammenhangs zwischen der Ausprägung fachspezifischer Interessen und schulischer Leistung. Es konnten für den Zeitraum 1965—1990 21 relevante Untersuchungsberichte identifiziert werden, die insgesamt 127 voneinander unabhängige (d. h. auf verschiedenen Stichproben beruhende) Korrelationskoeffizienten berichten. Ungeachtet der Einflüsse von Moderatorvariablen ergab sich für den Zusammenhang von Interesse und Leistung eine Durchschnittskorrelation von .30. Darüber hinaus zeigte sich, daß für Jungen signifikant höhere Interesse-Leistungs-Korrelationen bestehen als für Mädchen. Zwischen den verschiedenen Fächern ergaben sich teilweise ebenfalls signifikante Unterschiede. Dagegen war kein signifikanter Moderatoreffekt der Klassenstufe zu beobachten. Abschließend erfolgt eine Diskussion der Befunde auf dem Hintergrund interessentheoretischer und methodischer Überlegungen. N2 - This article presents results from a meta-analysis of studies on the relation between subject-matter-related interest and school achievement. For the time period between 1965 and 1990 a total of 21 studies reporting 127 independent correlations (i. e., correlations based on independent samples) were identified. For the overall relation between interestand achievement a mean correlation of .30 was found. Male students exhibited significantly higher interest-achievement correlations than female students. In addition, significant differences among school subjects were observed. Grade level, however, did not produce a significant moderator effect. Finally, the results are discussed on the basis of theories of interest and methodological considerations. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 056 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33561 ER - TY - JOUR A1 - Kurths, Jürgen A1 - Schwarz, Udo T1 - Application of techniques of nonlinear dynamics to SS Cyg N2 - We look for structural properties in the light curve of the dwarf nova SS Cyg by means of techniques from nonlinear dynamics. Applying the popular Grassberger-Procaccia procedure, Cannizzo and Goddings (1988) showed that there is no evidence for a low-dimensional attractor underlying this record. Because there are some hints for order in the light curve, we search for other signatures of deterministic systems. Therefore, we use other methods recently developed in this theory, such as local linear prediction and recurrence maps. Our main findings are: i] the prediction error grows exponentially during outburst phases, but via a power law in the quiescent states, ii] there are some rather regular patterns in this light curve which sometimes recur, but the recurrence is not regular. This leads to the following conclusions: i] The outburst dynamics shows a higher degree of order than the quiescent one. There are some hints for deterministic chaos in the outburst behavior. ii] The light curve is a complex mixture of deterministic and stochastic structures. The analysis presented in this paper shows that methods of nonlinear dynamics can be an efficient tool for the study of complex processes, even if there is no evidence for a low-dimensional attractor. Y1 - 1993 UR - http://www.agnld.uni-potsdam.de/~shw/Paper/SS_Cyg_AIP.ps.gz SN - 0-7503-0282-8 ER - TY - GEN A1 - Laschewsky, André A1 - Schulz-Hanke, Wolfgang T1 - Ring-opening metathesis polymerization of amphiphilic norbornenes functionalized with non-linear optical (NLO) chromophores N2 - Contents: Potential of amphiphilic NLO polymers Ring-opening metathesis polymerization (ROMP) Properties of the polymers Monolayer properties Experimental part - Methods - Materials - Analytical data - General polymerization procedure Conclusions T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 092 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-26917 ER - TY - JOUR A1 - Lehmann, J. A1 - Kleinpeter, Erich T1 - 1H NMR Lanthanideinduced Shift (LIS) investigations of highly flexible molecules : a new approach ; Part II Y1 - 1993 ER - TY - JOUR A1 - Lehmann, J. A1 - Kleinpeter, Erich T1 - 1H NMR Lanthanideinduced Shift (LIS) investigations of highly flexible molecules : a new approach Y1 - 1993 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 - JOUR A1 - Lindenberger, Ulman A1 - Mayr, Ulrich A1 - Kliegl, Reinhold T1 - Speed and intelligence in old age Y1 - 1993 ER - TY - JOUR A1 - Louis, Alfred K. A1 - Maaß, Peter T1 - Contour reconstructions for 3D X-Ray CT-Images Y1 - 1993 ER - TY - JOUR A1 - Lüth, Christoph T1 - State-controlled and private education in Rousseau : two mutually exclusive theories? Y1 - 1993 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 - JOUR A1 - Mayr, Ulrich A1 - Kliegl, Reinhold T1 - Sequential and coordinative complexity : age-based processing limitations in figural transformation 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 (Exp 1), was obtained when age groups were equated in accuracy with criterion-referenced testing (Exp 2), and was corroborated by age-differential probabilities of error types (Exps 1 and 2). A model is proposed attributing age effects under coordinative complexity to 2 factors: (1) basic- level slowing and (2) time-consuming reiterations through the processing sequence due to age-related working memory failures. (PsycINFO Database Record (c) 2012 APA, all rights reserved) Y1 - 1993 SN - 0278-7393 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Liquid-liquid-extraction of copper from ammoniacal solution with 4-acylpyrazol-5-ones and ß-diketones Y1 - 1993 SN - 1-85861-042-7 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Liquid-Liquid-Extraction of copper from ammoniacal solution with cyclohexyl substituted ß-diketones Y1 - 1993 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Liquid-Liquid-Extraction of copper from ammoniacal solutions with 4-Acylpyrazolones Y1 - 1993 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 - JOUR A1 - Pfeiffer, Dorothea A1 - Scheller, Frieder W. A1 - Schubert, Florian A1 - Setz, K. T1 - Amperometric enzyme electrodes for lactate and glucose determinations in highly diluted and undiluted media Y1 - 1993 ER - TY - JOUR A1 - Pfeil, Wolfgang T1 - Thermodynamics of apocytochrome b5 unfolding Y1 - 1993 ER - TY - JOUR A1 - Pfeil, Wolfgang A1 - Nölting, Bengt A1 - Jung, Christiane T1 - Apocytochrome P450cam is a native protein with some intermediate-like properties Y1 - 1993 ER - TY - JOUR A1 - Pfeil, Wolfgang A1 - Nölting, Bengt A1 - Jung, Christiane T1 - Thermodynmic properties of apocytochrome P450cam Y1 - 1993 ER - TY - GEN A1 - Püschel, Gerhard Paul A1 - Hespeling, Ursula A1 - Oppermann, Martin A1 - Dieter, Peter T1 - Increase in prostanoid formation in rat liver macrophages (Kupffer cells) by human anaphylatoxin C3a N2 - Human anaphylatoxin C3a increases glycogenolysis in perfused rat liver. This action is inhibited by prostanoid synthesis inhibitors and prostanoid antagonists. Because prostanoids but not anaphylatoxin C3a can increase glycogenolysis in hepatocytes, it has been proposed that prostanoid formation in nonparenchymal cells represents an important step in the C3a-dependent increase in hepatic glycogenolysis. This study shows that (a) human anaphylatoxin C3a (0.1 to 10 mug/ml) dose-dependently increased prostaglandin D2, thromboxane B, and prostaglandin F2alpha formation in rat liver macrophages (Kupffer cells); (b) the C3a-mediated increase in prostanoid formation was maximal after 2 min and showed tachyphylaxis; and (c) the C3a-elicited prostanoid formation could be inhibited specifically by preincubation of C3a with carboxypeptidase B to remove the essential C-terminal arginine or by preincubation of C3a with Fab fragments of a neutralizing monoclonal antibody. These data support the hypothesis that the C3a-dependent activation of hepatic glycogenolysis is mediated by way of a C3a-induced prostanoid production in Kupffer cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 037 KW - lactate output KW - glucose KW - complement KW - flow KW - prostaglandin-f2-alpha Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16716 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 - 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 - BOOK A1 - Rainer, Martin T1 - Orientation duality of 4-dimensional real Lie algebras T3 - Preprint / Universität Potsdam, Fachbereich Mathematik Y1 - 1993 VL - 1993, 08 PB - Univ. CY - Potsdam ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Kirstein, Dieter A1 - Schubert, Florian A1 - Pfeiffer, Dorothea A1 - McNeil, C. J. T1 - Enzymes in electrochemical biosensors Y1 - 1993 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Wollenberger, Ursula A1 - Schubert, Florian A1 - Pfeiffer, Dorothea A1 - Markower, Alexander A1 - McNeil, C. J. T1 - Multienzyme biosensors : coupled enzyme reactions and enzyme activation Y1 - 1993 ER - TY - BOOK A1 - Schmidt, Hans-Jürgen T1 - Comment to a paper by J. Simon in Phys. Rev. D 45 (1992) 1953 T3 - Preprint / Universität Potsdam, Fachbereich Mathematik Y1 - 1993 VL - 1993, 06 PB - Univ. CY - Potsdam ER - TY - JOUR A1 - Schneider, Ingo A1 - Müller, Bernd A1 - Wilke, U.-B T1 - Saisonal variation of microorganisms in a sewage farm ares south of Berlin Y1 - 1993 ER - TY - JOUR A1 - Schulte, Christoph T1 - Le psychiatre et la critique de la culture : Max Nordau Y1 - 1993 SN - 2-204-04858-5 ER - TY - JOUR A1 - Schwarz, udo A1 - Benz, Arnold O. A1 - Kurths, Jürgen A1 - Witt, Annette T1 - Analysis of solar spike events by means of symbolic dynamics methods N2 - Using quantities of symbolic dynamics, such as mutual information, Shannon information and algorithmic complexity, we have searched for interrelations of spikes emitted simultaneously at different frequencies during the impulsive phase of a flare event. As the spikes are related to the flare energy release and are interpreted as emissions originating at different sites having different magnetic field strengths, any relation in frequency is interpretated as a relation in space. This approach is appropriate to characterize such spatio-temporal patterns, whereas the popular estimate of fractal dimensions can be applied to low-dimensional systems only. Depending on the energy release and emission processes, two types of fragmentation are possible: a scenario of global organization (spikes are emitted in a succession of similar events by the same system) or a scenario of local organization (many systems triggered by an initial event). Mutual information which is a generalization of correlation indicates a relation in frequency beyond the bandwidth of individual spikes. The scans in the spectrograms with large mutual information also show a low level of Shannon information and algorithmic complexity, indicating that the simultaneous appearance of spikes at other frequencies is not a completely stochastic phenomenon (white noise). It may be caused by a nonlinear deterministic system or by a Markov process. By means of mutual information we find a memory over frequency intervals up to 60 MHz. Shannon information and algorithmic complexity concern the mbox{whole} frequency region, i.e. the global source region. A global organization is also apparent in quasi-periodic changes of the Shannon information and algorithmic complexity in the range of 2 - 8 seconds. The finding is compatible with a scenario of local organization in which the information of one event spreads spatially and triggers further events at different places. The region is not an ensemble of independently flashing sources, each representing a system that cascades in energy after an initial trigger. On the contrary, there is a causal connection between the sources at any time. The analysis of the four spike events suggests that the structure in frequency is not stochastic but a process in which spikes at nearby locations are simultaneously triggered by a common exciter. Y1 - 1993 UR - http://www.astro.phys.ethz.ch/papers/benz/schwarz/schwarz/schwarz.html SN - 004-6361 ER -