TY  - GEN
A1  - Zyla, Benjamin
T1  - Multilateralism à la Carte? : The Bush II administration and US foreign policy
N2  - The use of unilateral force under George W. Bush is not a new phenomenon in US foreign policy. As the author argues, it is merely a continuation of Bill Clinton’s foreign policy and is deeply rooted in both the foreign policy traditions of Jacksonianism and Wilsonianism. The analysis concludes that Clinton used unilateralist foreign policy with a 'smile' whereas the Bush administration uses it with an attitude.
N2  - Die unilaterale Außenpolitik unter George W. Bush ist kein neues Phänomen der US-Diplomatie. Dem Autor zufolge ist sie vielmehr eine Fortführung der Politik der Clinton-Regierung und hat ihre Wurzeln in den Traditionen eines Andrew Jackson und Woodrow Wilson. Clinton vermochte jedoch seine unilaterale Politik mit einem "Lächeln" zu verkaufen, wohingegen die Art und Weise der Bush-Administration stets Irritationen hervorrief.
KW  - US-Außenpolitik
KW  - George W. Bush
KW  - Unilateralismus
KW  - US foreign policy
KW  - George W. Bush
KW  - unilateralism
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13439
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  - 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  - Werner, John S.
A1  - Donnelly, Seaneen K.
A1  - Kliegl, Reinhold
T1  - Aging and human macular pigment density : appended with translations from the work of Max Schultze and Ewald Hering
N2  - The optical density of human macular pigment was measured for 50 observers ranging in age from 10 to 90 years. The psychophysical method required adjusting the radiance of a 1°, monochromatic light (400–550 nm) to minimize flicker (15 Hz) when presented in counterphase with a 460 nm standard. This test stimulus was presented superimposed on a broad-band, short-wave background. Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5° temporally. This difference spectrum, measured for 12 observers, matched Wyszecki and Stiles's standard density spectrum for macular pigment. To study variation in macular pigment density for a larger group of observers, measurements were made at only selected spectral points (460, 500 and 550 nm). The mean optical density at 460 nm for the complete sample of 50 subjects was 0.39. Substantial individual differences in density were found (ca. 0.10–0.80), but this variation was not systematically related to age.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 037 
KW  - Macular pigment
KW  - Color vision Aging
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16836
ER  - 
TY  - GEN
A1  - Werner, John S.
A1  - Cicerone, Carola M.
A1  - Kliegl, Reinhold
A1  - DellaRosa, Denise
T1  - Spectral efficiency of blackness induction
N2  - The spectral efficiency of blackness induction was measured in three normal trichromatic observers and in one deuteranomalous observer. The psychophysical task was to adjust the radiance of a monochromatic 60–120′ annulus until a 45′ central broadband field just turned black and its contour became indiscriminable from a dark surrounding gap that separated it from the annulus. The reciprocal of the radiance required to induce blackness with annulus wavelengths between 420 and 680 nm was used to define a spectral-efficiency function for the blackness component of the achromatic process. For each observer, the shape of this blackness-sensitivity function agreed with the spectral-efficiency function based on heterochromatic flicker photometry when measured with the same 60–120′ annulus. Both of these functions matched the Commission Internationale de l'Eclairage Vλ function except at short wavelengths. Ancillary measurements showed that the latter difference in sensitivity can be ascribed to nonuniformities of preretinal absorption, since the annular field excluded the central 60′ of the fovea. Thus our evidence indicates that, at least to a good first approximation, induced blackness is inversely related to the spectral-luminosity function. These findings are consistent with a model that separates the achromatic and the chromatic pathways.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 040 
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16897
ER  - 
TY  - GEN
A1  - Watanabe, Yuji
A1  - Püschel, Gerhard Paul
A1  - Gardemann, Andreas
A1  - Jungermann, Kurt
T1  - Presinusoidal and proximal intrasinusoidal confluence of hepatic artery and portal vein in rat liver : functional evidence by orthograde and retrograde bivascular perfusion
N2  - The site of confluence of the artery and the portal vein in the liver still appears to be controversial. Anatomical studies suggested a presinusoidal or an intrasinusoidal confluence in the first, second or even final third of the sinusoids. The objective of this investigation was to study the problem with functional biochemical techniques. Rat livers were perfused through the hepatic artery and simultaneously either in the orthograde direction from the portal vein to the hepatic vein or in the retrograde direction from the hepatic vein to the portal vein. Arterial how was linearly dependent on arterial pressure between 70 cm H2O and 120 cm H2O at a constant portal or hepatovenous pressure of 18 cm H2O. An arterial pressure of 100 cm H2O was required for the maintenance of a homogeneous orthograde perfusion of the whole parenchyma and of a physiologic ratio of arterial to portal how of about 1:3. Glucagon was infused either through the artery or the portal vein and hepatic vein, respectively, to a submaximally effective ''calculated'' sinusoidal concentration after mixing of 0.1 nmol/L. During orthograde perfusions, arterial and portal glucagon caused the same increases in glucose output. Yet during retrograde perfusions, hepatovenous glucagon elicited metabolic alterations equal to those in orthograde perfusions, whereas arterial glucagon effected changes strongly reduced to between 10% and 50%. Arterially infused trypan blue was distributed homogeneously in the parenchyma during orthograde perfusions, whereas it reached clearly smaller areas of parenchyma during retrograde perfusions. Finally, arterially applied acridine orange was taken up by all periportal hepatocytes in the proximal half of the acinus during orthograde perfusions but only by a much smaller portion of periportal cells in the proximal third of the acinus during retrograde perfusions. These findings suggest that in rat liver, the hepatic artery and the portal vein mix before and within the first third of the sinusoids, rather than in the middle or even last third.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 067 
KW  - Hepatic artery
KW  - Portal vein
KW  - Confluence
KW  - Rat
KW  - Animal
KW  - Experimental study
KW  - Anatomy
KW  - Biochemical analysis
KW  - Technique
KW  - Perfusion
KW  - Exploration
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16702
ER  - 
TY  - GEN
A1  - Ward, Colleen
A1  - Newlon, Betty
A1  - Krahé, Barbara
A1  - Myambo, Kathleen
A1  - Payne, Monica
A1  - Tastaban, Yildiz
A1  - Yuksel, Sahika
A1  - Ghadially, Rehana
A1  - Kumar, Usha
A1  - Lee, Hing-chu B
A1  - Cheung, Fanny M.
A1  - Upadhyaya, Shirpati
A1  - Patnoe, Jerry
A1  - Kirby, Carol
A1  - Gomez, Antonio Vasquez
A1  - Parra, Elena
A1  - Colosio, Laura
T1  - The attitudes toward rape victims scale : psychometric data from 14 countries
N2  - Content: Synopsis The Attitudes toward Rape Victims Scale: Psychometric Data from 14 Countries Scale Construction and Validation - Study One: Preliminary Analyses - Study Two: Test-Retest Reliability - Study Three: Construct Validity Cross-cultural Extensions - United States - United Kingdom - Germany - New Zealand - Canada - West Indies - Israel - Turkey - India - Hong Kong - Malaysia - Zimbabwe - Mexico - Metric Equivalence Discussion
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 085 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-34495
ER  - 
TY  - GEN
A1  - Wacker, Alexander
A1  - von Elert, Eric
T1  - Polyunsaturated fatty acids : evidence for non-substitutable biochemical resources in Daphnia galeata
N2  - The factors that determine the efficiency of energy transfer in aquatic food webs have been investigated for many decades. The plant-animal interface is the most variable and least predictable of all levels in the food web. In order to study determinants of food quality in a large lake and to test the recently proposed central importance of the long-chained eicosapentaenoic acid (EPA) at the pelagic producer-grazer interface, we tested the importance of polyunsaturated fatty acids (PUFAs) at the pelagic producerconsumer interface by correlating sestonic food parameters with somatic growth rates of a clone of Daphnia galeata. Daphnia growth rates were obtained from standardized laboratory experiments spanning one season with Daphnia feeding on natural seston from Lake Constance, a large pre-alpine lake. Somatic growth rates were fitted to sestonic parameters by using a saturation function. A moderate amount of variation was explained when the model included the elemental parameters carbon (r2 = 0.6) and nitrogen (r2 = 0.71). A tighter fit was obtained when sestonic phosphorus was incorporated (r2 = 0.86). The nonlinear regression with EPA was relatively weak (r2 = 0.77), whereas the highest degree of variance was explained by three C18-PUFAs. The best (r2 = 0.95), and only significant, correlation of Daphnia's growth was found with the C18-PUFA α-linolenic acid (α-LA; C18:3n-3). This correlation was weakest in late August when C:P values increased to 300, suggesting that mineral and PUFA-limitation of Daphnia's growth changed seasonally. Sestonic phosphorus and some PUFAs showed not only tight correlations with growth, but also with sestonic α-LA content. We computed Monte Carlo simulations to test whether the observed effects of α-LA on growth could be accounted for by EPA, phosphorus, or one of the two C18-PUFAs, stearidonic acid (C18:4n-3) and linoleic acid (C18:2n-6). With >99 % probability, the correlation of growth with α-LA could not be explained by any of these parameters. In order to test for EPA limitation of Daphnia's growth, in parallel with experiments on pure seston, growth was determined on seston supplemented with chemostat-grown, P-limited Stephanodiscus hantzschii, which is rich in EPA. Although supplementation increased the EPA content 80-800x, no significant changes in the nonlinear regression of the growth rates with α-LA were found, indicating that growth of Daphnia on pure seston was not EPA limited. This indicates that the two fatty acids, EPA and α-LA, were not mutually substitutable biochemical resources and points to different physiological functions of these two PUFAs. These results support the PUFA-limitation hypothesis for sestonic C:P < 300 but are contrary to the hypothesis of a general importance of EPA, since no evidence for EPA limitation was found. It is suggested that the resource ratios of EPA and α-LA rather than the absolute concentrations determine which of the two resources is limiting growth.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 063 
KW  - alga
KW  - consumer
KW  - Daphnia
KW  - fatty acid
KW  - food quality
KW  - grazer
KW  - herbivore
KW  - Lake Constance
KW  - European Alps
KW  - PUFA
KW  - seston
Y1  - 2001
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17587
ER  - 
TY  - GEN
A1  - Wacker, Alexander
A1  - von Elert, Eric
T1  - Strong influences of larval diet history on subsequent post-settlement growth in the freshwater mollusc Dreissena polymorpha
N2  - Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 064 
KW  - Dreissena polymorpha
KW  - food quality
KW  - fatty acid
KW  - life history
KW  - metamorphosis
KW  - PUFA
Y1  - 2002
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17627
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  - 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  - Tsukruk, Vladimir
A1  - Mischenko, Nikolay
A1  - Köberle, Peter
A1  - Laschewsky, André
T1  - The structural order of some novel ionic polymers; 2. : Models of molecular packing
N2  - The molecular packing and spatial correlations of two isomeric zwitterionic polymethacrylates and one polyacrylate analog are studied by means of X-ray analysis and conformational calculations. The analysis of the correlation functions and density distribution profiles suggest a double-layered molecular packing which is discussed for the three polymers investigated, with respect to their different chemical structures. Whereas the zwitterionic polymethacrylates studied exhibit liquid-like short-range order, the polyacrylate analog exhibits an ordered double-layered superstructure.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 096 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17256
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  - 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  - 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  - 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  - 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  - 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  - Tavassoli, Gholam-Abbas
T1  - Islamic movements in Iran
N2  - The modernist Islamic Movement sought to reconcile modern values and Islamic faith and attempted to express these values through an Islamic discourse and to reform political, religious and educational institutions along modernist lines. However, such a movement in the Islamic Republic of Iran raised controversy among the traditional leadership and secular intellectual groups. The aim of this paper is to discuss how far modernist Islam could progress in an islamic republic with an old tradition.
KW  - Iran
KW  - Modernisierung
KW  - Islam
KW  - islamistische Bewegungen
KW  - Iran
KW  - modernization
KW  - Islam
KW  - Islamic movements
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-9699
ER  - 
TY  - GEN
A1  - Stieglitz, Stefan
A1  - Fuchß, Christoph
A1  - Lattemann, Christoph
T1  - Mobile learning by using ad hoc messaging network
N2  - The requirements of modern e-learning techniques change. Aspects such as community interaction, flexibility, pervasive learning and increasing mobility in communication habits become more important. To meet thesechallenges e-learning platforms must provide support on mobile learning. Most approaches try to adopt centralized and static elearning mechanisms to mobile devices. However, often technically it is not possible for all kinds of devices to be connected to a central server. Therefore we introduce an application of a mobile e-learning network which operates totally decentralized with the help of an underlying ad hoc network architecture. Furthermore the concept of ad hoc messaging network (AMNET) is used as basis system architecture for our approach to implement a platform for pervasive mobile elearning.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - paper 014 
KW  - mobile learning
KW  - ad hoc learning
KW  - e-learning platform
KW  - AMNET
KW  - ad hoc messaging network
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-19979
SN  - 1867-5808
ER  - 
TY  - GEN
A1  - Stieglitz, Stefan
A1  - Fuchß, Christoph
A1  - Hillmann, Oliver
A1  - Lattemann, Christoph
T1  - Mobile learning by using ad hoc messaging network
N2  - The requirements of modern e-learning techniques change. Aspects such as community interaction, flexibility, pervasive learning and increasing mobility in communication habits become more important. To meet these challenges e-learning platforms must provide support on mobile learning. Most approaches try to adopt centralised and static e-learning mechanisms to mobile devices. However, often technically it is not possible for all kinds of devices to be connected to a central server. Therefore we introduce an application of a mobile e-learning network which operates totally decentralised with the help of an underlying ad hoc network architecture. Furthermore the concept of ad hoc messaging network (AMNET) is used as basis system architecture for our approach to implement a platform for pervasive mobile e-learning.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - paper 015 
KW  - Mobile learning
KW  - ad hoc learning
KW  - community
KW  - e-learning platform
KW  - AMNET
KW  - ad hoc messaging network
KW  - pervasive learning
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-19960
SN  - 1867-5808
ER  - 
TY  - GEN
A1  - Six, Bernd
A1  - Krahé, Barbara
T1  - Implicit psychologists' estimates of attitude-behaviour consistencies
N2  - To investigate the relationship between implicit psychological hypotheses and explicit empirical findings, summaries of twenty published studies on attitude-behaviour consistency were presented to a sample of forty-eight psychology undergraduates. Subjects were asked to estimate the percentage of agreement between attitudes and behaviour obtained by each study. Correlations between subjects' covariation judgements and empirically obtained attitude-behaviour consistencies were minimal and nonsignificant. Results are discussed in the light of more recent research on attitudebehaviour relationship.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 078 
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-34427
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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - Schuler, Benjamin
A1  - Lipman, Everett A.
A1  - Steinbach, Peter J.
A1  - Kumke, Michael Uwe
A1  - Eaton, William A.
T1  - Polyproline and the "spectroscopic ruler" revisited with single-molecule fluorescence
N2  - To determine whether Förster resonance energy transfer (FRET) measurements can provide quantitative distance information in single-molecule fluorescence experiments on polypeptides, we measured FRET efficiency distributions for donor and acceptor dyes attached to the ends of freely diffusing polyproline molecules of various lengths. The observed mean FRET efficiencies agree with those determined from ensemble lifetime measurements but differ considerably from the values expected from Förster theory, with polyproline treated as a rigid rod. At donor–acceptor distances much less than the Förster radius R0, the observed efficiencies are lower than predicted, whereas at distances comparable to and greater than R0, they are much higher. Two possible contributions to the former are incomplete orientational averaging during the donor lifetime and, because of the large size of the dyes, breakdown of the point-dipole approximation assumed in Förster theory. End-to-end distance distributions and correlation times obtained from Langevin molecular dynamics simulations suggest that the differences for the longer polyproline peptides can be explained by chain bending, which considerably shortens the donor–acceptor distances.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 008 
KW  - Förster resonance energy transfer
KW  - molecular dynamics
KW  - polypeptide
KW  - FRET
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12229
ER  - 
TY  - GEN
A1  - Schmälzlin, Elmar
A1  - Walz, Bernd
A1  - Klimant, Ingo
A1  - Schewe, Bettina
A1  - Löhmannsröben, Hans-Gerd
T1  - Monitoring hormone-induced oxygen consumption in the salivary glands of the blowfly, Calliphora vicina, by use of luminescent microbeads
N2  - The salivary glands of the blowfly were injected with luminescent oxygen-sensitive microbeads. The changes in oxygen content within individual gland tubules during hormone-induced secretory activity were quantified. The measurements are based on an upgraded phase-modulation technique, where the phase shift of the sensor phosphorescence is determined independently from concentration and background signals. We show that the combination of a lock-in amplifier with a fluorescence microscope results in a convenient setup to measure oxygen concentrations within living animal tissues at the cellular level.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 006 
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12206
ER  - 
TY  - GEN
A1  - Schmälzlin, Elmar
A1  - Dongen, Joost T. van
A1  - Klimant, Ingo
A1  - Marmodée, Bettina
A1  - Steup, Martin
A1  - Fishahn, Joachim
A1  - Geigenberger, Peter
A1  - Löhmannsröben, Hans-Gerd
T1  - An optical multifrequency phase-modulation method using microbeads for measuring intracellular oxygen concentrations in plants
N2  - A technique has been developed to measure absolute intracellular oxygen concentrations in green plants. Oxygen-sensitive phosphorescent microbeads were injected into the cells and an optical multifrequency phase-modulation technique was used to discriminate the sensor signal from the strong autofluorescence of the plant tissue. The method was established using photosynthesis-competent cells of the giant algae Chara corallina L., and was validated by application to various cell types of other plant species.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 007 
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12232
ER  - 
TY  - GEN
A1  - Schiefele, Ulrich
T1  - Topic interest and levels of text comprehension
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 067 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33696
ER  - 
TY  - GEN
A1  - Schiefele, Ulrich
T1  - The importance of motivational factors for the acquisition and representation of knowledge
N2  - Motivational conditions have been thus far largely neglected by contemporary theoretical approaches in knowledge psychology. The present article attempts to demonstrate the necessity for the greater integration of both. Suggestions are made regarding the choice and conceptualization of relevant motivational factors. Two possible groups of factors can be distinguished: (1) motivational factors of personality, and (2) motivational effects of action. Available theoretical approaches (e.g., the "levels of processing" approach) and examples are used to clarify the potential effects of these factors on the acquisition and representation of knowledge. Finally, a review is made of empirical studies allowing confirmatory allegations about the posited relationships between motivational factors and processes related to knowledge. This review reveals substantial research deficits on this topic.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 044 
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33421
ER  - 
TY  - GEN
A1  - Schiefele, Ulrich
T1  - Interest, learning, and motivation
N2  - Recent research related to the concept of interest is reviewed. It is argued that current constructs of motivation fail to include crucial aspects of the meaning of interest emphasized by classical American and German educational theorists. In contrast with many contemporary concepts (e.g., intrinsic learning orientation), interest is defined as a content-specific motivational characteristic composed of intrinsic feeling-related and value-related valences. Results from a number of studies are presented that indicate the importance of interest for the depth of text comprehension, the use of learning strategies, and the quality of the emotional experience while learning. The implications of these results and possible directions for future research are discussed.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 053 
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33536
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  - Sanner, Helge
T1  - Imperfect goods and labor markets, and the union wage gap
N2  - Existing theoretical literature fails to explain satisfactorily the differences between the pay of workers that are covered by collective agreements and others who are not. This study aims at providing a model framework which is amenable for an analysis of this issue. Our general-equilibrium approach integrates a dual labor market and a two-sector product market. The results suggest that the so-called 'union wage gap' is largely determined by the degree of centralization of the bargains, and, to a somewhat lesser extent, by the expenditure share of the unionized sector's goods.
KW  - Verhandlungstheorie
KW  - Monopolistische Konkurrenz
KW  - Gewerkschaften
KW  - union wage premium
KW  - comparative analysis
KW  - wage differentials
KW  - dual labor market
KW  - monopolistic competition
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6511
ER  - 
TY  - GEN
A1  - Rozanski, Stanislaw A.
A1  - Kremer, Friedrich
A1  - Köberle, Peter
A1  - Laschewsky, André
T1  - Relaxation and charge transport in mixtures of zwitterionic polymers and inorganic salts
N2  - Dielectric spectroscopy is employed to analyze the molecular dynamics and the charge transport in mixtures of zwitterionic polymers of the type poly{3 [N(-methacryloyloxyalkyl)] N, [N-dimethylammonio propanesulfonate] with sodium iodide in the frequency range of 10²Hz-10(up)7 Hz and in the temperature range of 110 K-400 K. The amount of inorganic salt added varies from 0-200 mol-% relative to the number of zwitterionic groups present in the polymer, contributing strongly to the conductivity. One relaxation process is observed whose relaxation rate depends strongly on the length of the aliphatic spacer between the polymethacrylate main chain and the zwitterionic group. Exhibiting an Arrhenius-like temperature depence with activation energy EA = 47 KJ/mol, this relaxation process is assigned to fluctuation of the quaternary ammonium groups in the side chains. At higher temperatures, the dielectric properties and the conductivity are primarily dominated by the mobile inorganic ions: conductivity strongly depends on the salt concentration, showing a pronounced electrode polarization effect. The frequency and salt concentration, dependences of the conductivity can be quantitatively described as hopping of charge carriers being subject to spatially randomly varying energy barriers. For the low-frequency regime and for the critical frequency marking the onset of the conductivity's dispersion, the Barton-Nakajima-Namikawa (BNN) relationship is fulfilled.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 093 
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17438
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  - 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  - 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  - 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  - Reich, Sebastian
T1  - Smoothed dynamics of highly oscillatory Hamiltonian systems
N2  - We consider the numerical treatment of Hamiltonian systems that contain a potential which grows large when the system deviates from the equilibrium value of the potential. Such systems arise, e.g., in molecular dynamics simulations and the spatial discretization of Hamiltonian partial differential equations. Since the presence of highly oscillatory terms in the solutions forces any explicit integrator to use very small step size, the numerical integration of such systems provides a challenging task. It has been suggested before to replace the strong potential by a holonomic constraint that forces the solutions to stay at the equilibrium value of the potential. This approach has, e.g., been successfully applied to the bond stretching in molecular dynamics simulations. In other cases, such as the bond-angle bending, this methods fails due to the introduced rigidity. Here we give a careful analysis of the analytical problem by means of a smoothing operator. This will lead us to the notion of the smoothed dynamics of a highly oscillatory Hamiltonian system. Based on our analysis, we suggest a new constrained formulation that maintains the flexibility of the system while at the same time suppressing the high-frequency components in the solutions and thus allowing for larger time steps. The new constrained formulation is Hamiltonian and can be discretized by the well-known SHAKE method.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 031 
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-15639
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  - 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  - Momentum conserving symplectic integrators
N2  - In this paper, we show that symplectic partitioned Runge-Kutta methods conserve momentum maps corresponding to linear symmetry groups acting on the phase space of Hamiltonian differential equations by extended point transformation. We also generalize this result to constrained systems and show how this conservation property relates to the symplectic integration of Lie-Poisson systems on certain submanifolds of the general matrix group GL(n).
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 044 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16824
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  - Reich, Oliver
A1  - Löhmannsröben, Hans-Gerd
A1  - Schael, Frank
T1  - Optical sensing with photon density waves: investigation of model media
N2  - Investigations with frequency domain photon density waves allow elucidation of absorption and scattering properties of turbid media. The temporal and spatial propagation of intensity modulated light with frequencies up to more than 1 GHz can be described by the P1 approximation to the Boltzmann transport equation. In this study, we establish requirements for the appropriate choice of turbid model media and characterize mixtures of isosulfan blue as absorber and polystyrene beads as scatterer. For these model media, the independent determination of absorption and reduced scattering coefficients over large absorber and scatterer concentration ranges is demonstrated with a frequency domain photon density wave spectrometer employing intensity and phase measurements at various modulation frequencies.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 026 
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13147
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Oppermann, Martin
A1  - Neuschäfer-Rube, Frank
A1  - Götze, Otto
A1  - Jungermann, Kurt
T1  - Differential effects of human anaphylatoxin C3a on glucose output and flow in rat liver during orthograde and retrograde perfusion : the periportal scavenger cell hypothesis
N2  - 1) During orthograde perfusion of rat liver human anaphylatoxin C3a caused an increase in glucose and lactate output and reduction of flow. These effects could be enhanced nearly twofold by co-infusion of the carboxypeptidase inhibitor MERGETPA, which reduced inactivation of C3a to C3adesArg. 2) During retrograde perfusion C3a caused a two- to threefold larger increase in glucose and lactate output and reduction of flow than in orthograde perfusions. These actions tended to be slightly enhanced by MERGETPA. 3) The elimination of C3a plus C3adesArg immunoreactivity during a single liver passage was around 67%, irrespective of the perfusion direction and the presence of the carboxypeptidase inhibitor MERGETPA; however, less C3adesArg and more intact C3a appeared in the perfusate in the presence of MERGETPA in orthograde and retrogade perfusions It is concluded that rat liver inactivated human anaphylatoxin C3a by conversion to C3adesArg and moreover eliminated it by an additional process. The inactivation to C3adesArg seemed to be located predominantly in the proximal periportal region of the liver sinusoid, since C3a was less effective in orthograde perfusions, when C3a first passed the proximal periportal region before reaching the predominant mass of parenchyma as its site of action, than in retrograde perfusions, when it first passed the perivenous area. These data may be evidence for a periportal scavenger mechanism, by which the liver protects itself from systemically released mediators of inflammation that interfere with the local regulation of liver metabolism and hemodynamics.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 040 
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16747
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  - Püschel, Gerhard Paul
A1  - Nath, Annegret
A1  - Jungermann, Kurt
T1  - Increase of urate formation by stimulation of sympathetic hepatic nerves, circulating noradrenaline and glucagon inthe perfused rat liver
N2  - In the isolated rat liver perfused in situ stimulation of the nerve bundles around the portal vein and the hepatic artery caused an increase of urate formation that was inhibited by the α1-blocker prazosine and the xanthine oxidase inhibitor allopurinol. Moreover, nerve stimulation increased glucose and lactate output and decreased perfusion flow. Infusion of noradrenaline had similar effects. Compared to nerve stimulation infusion of glucagon led to a less pronounced increase of urate formation and a twice as large increase in glucose output but a decrease in lactate release without affecting the flow rate. Insulin had no effect on any of the parameters studied.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 038 
KW  - Urate
KW  - Allantoin
KW  - Hepatic nerve
KW  - Catecholamine
KW  - Glucagon
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16728
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  - 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  - 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  - 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  - 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  - 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  - 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  - Peter, Martin G.
A1  - Andersen, Svend Olav
A1  - Hartmann, Rudolf
A1  - Miessner, Merle
A1  - Roepstorff, Peter
T1  - Catecholamine-protein conjugates : isolation of 4-phenylphenoxazin-2-ones from oxidative coupling of N-acetyldopamine with alipathic amino acids
N2  - 4-Phenylphenoxazinones were isolated after biomimetic oxidation, using diphenoloxidases of insect cuticle, mushroom tyrosinase, or after autoxidation of N-acetyldopamine (Image ) in the presence of β-alanine, β-alanine methyl ester or N-acetyl-L-lysine. They are formed presumably by addition of 2-aminoalkyl-5-alkylphenols to the o-quinone of biphenyltetrol which, in turn, arises from oxidative coupling of. The structures of present the first examples for the assembly of reasonably stable intermediates in the rather complex process of chemical modifications of aliphatic amino acid residues by o-quinones.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 062 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17571
ER  - 
TY  - GEN
A1  - Peter, Martin G.
T1  - Products of in vitro oxidation of N-acetyldopamine as possible components in the sclerotization of insect cuticle
N2  - [1-14C]-N-Acetyldopamine (NADA) was oxidized in the presence of methyl [3-3H]-β-alanate with mushroom tyrosinase. The complex mixture of reaction products was partly resolved by chromatographic procedures and analyzed by spectroscopic methods. Methyl-β-alanate is incorporated to only a small extent into oxidation products of NADA which inter alia are presumed to be oligomeric hydroxyquinones. After oxidation of [1-14C, 2-3H]-NADA with preparations from tanning Manduca sexta pupal cuticle, N-acetylnoradrenalin was identified as one of the products. Binding of radioactivity to melanin-like material was also observed. These results suggest that oxidation products different from those formulated usually for the crosslinkages between protein amino groups and N-acetyldopaquinone are deposited in darkly brown coloured insect cuticles during sclerotization.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 041 
KW  - N-acetyldopamine
KW  - sclerotization
KW  - tyrosinase; o-quinones
KW  - tanning agents
Y1  - 1980
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16759
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  - Ott, Susan
A1  - van de Vijver, Ruben
A1  - Höhle, Barbara
T1  - The effect of phonotactic constraints in German-speaking children with delayed phonological acquisition : evidence from production of word-initial consonant clusters
N2  - In this study the effect of phonotactic constraints concerning word-initial consonant clusters in children with delayed phonological acquisition was explored. Twelve German-speaking children took part (mean age 5;1). The spontaneous speech of all children was characterized by the regular appearance of the error patterns fronting, e.g., Kuh (cow) → /tu:/, or stopping, e.g., Schaf (sheep) → /ta:f/, which were inappropriate for their chronological age. The children were asked to produce words (picture naming task, word repetition task) with initial consonant clusters, in which the application of the error patterns would violate phonotactic sequence constraints. For instance, if fronting would apply in /kl-/, e.g., Kleid (dress), it would be realized as the phontactically illegal consonant cluster /tl-/. The results indicate that phonotactic constraints affect word production in children with delayed phonological developments. Surprisingly, we found that children with fronting produced the critical consonants correctly significantly more often in word-initial consonant clusters than in words in which they appeared as singleton onsets. In addition, the results provide evidence for a similar developmental trajectory of acquisition in children with typical development and in children with delayed phonological acquisition. Keywords: Children with delayed phonological acquisition, phonotactic constraints, word-initial consonant clusters, fronting, stopping.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 027 
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16316
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  - Olson, Richard K.
A1  - Kliegl, Reinhold
A1  - Davidson, Brian J.
A1  - Foltz, Gregory
T1  - Individual and developmental differences in reading disability
N2  - I. Introduction A. Theoretical Framework and Selection of Tests B. Related Studies of Reading Disability Subtypes C. Overview of Specific Questions and Article Outline II. Selection criteria nd performance on standardized measures III. Group differences between disabled and normal readers A. Phonetic Memory B. Picture-Naming Speed and Automatic Responses to Print C. Phonological and Orthographic Skill D. Easy Regular and Exception Word Reading E. Difficult Regular and Exception Words IV. Individual diferences in reading disability A. Phonological Skill, Orthographic Skill, and the Regularity Effect B. Phonological Skill, Orthographic Skill, and Spelling Errors V. Eye movement reading style A. The "Plodder-Explorer" Dimension of Eye Movement Reading Style B. Eye Movements, Coding Skills, and Spelling Ratings C. Verbal Intelligence and the Plodder-Explorer Dimension D. Eye Movements in a Nonreading Task and the "Visual-Spatial" Subtype VI. Distribution and etiology of reading disabilities A. Distribution Issues B. Etiology of Reading Disabilities VII. Summary and new directions in research
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 142 
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-39916
ER  - 
TY  - GEN
A1  - Olson, Richard K.
A1  - Kliegl, Reinhold
A1  - Davidson, Brian J.
T1  - Eye Movements in Reading Disability
N2  - Contents: I. Introduction II. Word Coding Processes A. Word Recognition B. Orthographic Coding C. Phonological Coding III. Eye Monitor and Reading Task IV. Group Differences V. Dimensions of Individual Differences A. Regressive Fixation Index and Word Recognition B. Regressive Fixation Index and IQ C. Regressive Fixation Index and Saccade Length D. Regressive Fixation Index and Relative Phonological Skill VI. Multiple Regression Models of Individual Differences A. Disabled Readers in the Aloud Condition B. Disabled Readers in the Silent Condition C. Normal Readers in Silent and Aloud Conditions VII. Conclusions
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 139 
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-39880
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  - Olson, Richard K.
A1  - Davidson, Brian J.
A1  - Kliegl, Reinhold
A1  - Davies, Susan E.
T1  - Development of phonetic memory in disabled and normal readers
N2  - The development of phonetic codes in memory of 141 pairs of normal and disabled readers from 7.8 to 16.8 years of age was tested with a task adapted from L. S. Mark, D. Shankweiler, I. Y. Liberman, and C. A. Fowler (Memory & Cognition, 1977, 5, 623–629) that measured false-positive errors in recognition memory for foil words which rhymed with words in the memory list versus foil words that did not rhyme. Our younger subjects replicated Mark et al., showing a larger difference between rhyming and nonrhyming false-positive errors for the normal readers. The older disabled readers' phonetic effect was comparable to that of the younger normal readers, suggesting a developmental lag in their use of phonetic coding in memory. Surprisingly, the normal readers' phonetic effect declined with age in the recognition task, but they maintained a significant advantage across age in the auditory WISC-R digit span recall test, and a test of phonological nonword decoding. The normals' decline with age in rhyming confusion may be due to an increase in the precision of their phonetic codes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 039 
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16888
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  - Niederkrüger, Matthias
A1  - Salb, Christian
A1  - Beck, Michael
A1  - Hildebrandt, Niko
A1  - Löhmannsröben, Hans-Gerd
A1  - Marowsky, Gerd
T1  - Improvement of a fluorescence immunoassay with a compact diode-pumped solid state laser at 315 nm
N2  - We demonstrate the improvement of fluorescence immunoassay (FIA) diagnostics in deploying a newly developed compact diode-pumped solid state (DPSS) laser with emission at 315 nm. The laser is based on the quasi-three-level transition in Nd:YAG at 946 nm. The pulsed operation is either realized by an active Q-switch using an electro-optical device or by introduction of a Cr<SUP>4+</SUP>:YAG saturable absorber as passive Q-switch element. By extra-cavity second harmonic generation in different nonlinear crystal media we obtained blue light at 473 nm. Subsequent mixing of the fundamental and the second harmonic in a β-barium-borate crystal provided pulsed emission at 315 nm with up to 20 μJ maximum pulse energy and 17 ns pulse duration. Substitution of a nitrogen laser in a FIA diagnostics system by the DPSS laser succeeded in considerable improvement of the detection limit. Despite significantly lower pulse energies (7 μJ DPSS laser versus 150 μJ nitrogen laser), in preliminary investigations the limit of detection was reduced by a factor of three for a typical FIA.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 016 
KW  - Immunoassay
KW  - Fluoreszenz-Resonanz-Energie-Transfer
KW  - Neodym-YAG-Laser
KW  - 946 nm
KW  - 473 nm
KW  - 315 nm
KW  - gepulster DPSS Laser
KW  - sättigbarer Absorber
KW  - fluorescence immunoassay
KW  - 946 nm
KW  - 473 nm
KW  - 315 nm
KW  - pulsed DPSS laser
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10150
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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - MacWhinney, Brian
A1  - Bates, Elizabeth
A1  - Kliegl, Reinhold
T1  - Cue validity and sentence interpretation in English, German, and Italian
N2  - Linguistic and psycholinguistic accounts based on the study of English may prove unreliable as guides to sentence processing in even closely related languages. The present study illustrates this claim in a test of sentence interpretation by German-, Italian-, and English-speaking adults. Subjects were presented with simple transitive sentences in which contrasts of (1) word order, (2) agreement, (3) animacy, and (4) stress were systematically varied. For each sentence, subjects were asked to state which of the two nouns was the actor. The results indicated that Americans relied overwhelming on word order, using a first-noun strategy in NVN and a second-noun strategy in VNN and NNV sentences. Germans relied on both agreement and animacy. Italians showed extreme reliance on agreement cues. In both German and Italian, stress played a role in terms of complex interactions with word order and agreement. The findings were interpreted in terms of the “competition model” of Bates and MacWhinney (in H. Winitz (Ed.), Annals of the New York Academy of Sciences Conference on Native and Foreign Language Acquisition. New York: New York Academy of Sciences, 1982) in which cue validity is considered to be the primary determinant of cue strength. According to this model, cues are said to be high in validity when they are also high in applicability and reliability.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 038 
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16847
ER  - 
TY  - GEN
A1  - Löhmannsröben, Hans-Gerd
A1  - Beitz, Toralf
A1  - Luadien, Robert
A1  - Schultze, Rainer
T1  - Laser-based ion mobility spectrometry for sensing  of aromatic compounds
N2  - The drift time spectra of polycyclic aromatic hydrocarbons (PAH), alkylbenzenes and alkylphenylethers were recorded with a laser-based ion mobility (IM) spectrometer. The ion mobilities of all compounds were determined in helium as drift gas. This allows the calculation of the diffusion cross sections (Omegacalc) on the basis of the exact hard sphere scattering model (EHSSM) and their comparison with the experimentally determined diffusion cross sections (Omegaexp). These Omegaexp/Omegacalc-correlations are presented for molecules with a rigid structure like PAH and prove the reliability of the theoretical model and experimental method. The increase of the selectivity of IM spectrometry is demonstrated using resonance enhanced multiphoton ionisation (REMPI) at atmospheric pressure, realized by tuneable lasers. The REMPI spectra of nine alkylbenzenes and alkylphenylethers are investigated. On the basis of these spectra, the complete qualitative distinction of eight compounds in a mixture is shown. These experiments are extended to alkylbenzene isomer mixtures.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 003 
KW  - Laser
KW  - REMPI
KW  - Ion mobility spectrometry
KW  - PAH
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-11892
ER  - 
TY  - GEN
A1  - Löhmannsröben, Hans-Gerd
A1  - Beck, Michael
A1  - Hildebrandt, Niko
A1  - Schmälzlin, Elmar
A1  - van Dongen, Joost T.
T1  - New challenges in biophotonics : laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring
N2  - Two examples of our biophotonic research utilizing nanoparticles are presented, namely laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring. Results of the work include significantly enhanced sensitivity of a homogeneous fluorescence immunoassay and markedly improved spatial resolution of oxygen gradients in root nodules of a legume species.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 018 
KW  - Sauerstoff
KW  - Quantenpunkt
KW  - Lumineszenz
KW  - Immunoassay
KW  - Energietransfer
KW  - Fluoreszenz-Resonanz-Energie-Transfer
KW  - Nanopartikel
KW  - Lanthanoide
KW  - Optode
KW  - Förster Resonanz Energie Transfer
KW  - Biophotonik
KW  - biophotonics
KW  - nanoparticles
KW  - immunoassay
KW  - oxygen
KW  - optode
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10120
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  - Louis, Pierre-Yves
T1  - Ergodicity of PCA
BT  - equivalence between spatial and temporal mixing conditions
N2  - For a general attractive Probabilistic Cellular Automata on S-Zd, we prove that the (time-) convergence towards equilibrium of this Markovian parallel dynamics, exponentially fast in the uniform norm, is equivalent to a condition (A). This condition means the exponential decay of the influence from the boundary for the invariant measures of the system restricted to finite boxes. For a class of reversible PCA dynamics on {1,+1}(Zd), wit a naturally associated Gibbsian potential rho, we prove that a (spatial-) weak mixing condition (WM) for rho implies the validity of the assumption (A); thus exponential (time-) ergodicity of these dynamics towards the unique Gibbs measure associated to rho hods. On some particular examples we state that exponential ergodicity holds as soon as there is no phase transition.
KW  - Wahrscheinlichkeitstheorie
KW  - Wechselwirkende Teilchensysteme
KW  - Stochastische Zellulare Automaten
KW  - Interacting particle systems
KW  - Probabilistic Cellular Automata
KW  - ERgodicity of Markov Chains
KW  - Gibbs measures
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6589
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  - 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  - 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  - Lemke, Matthias
A1  - Fernández-Trujillo, Rebeca
A1  - Löhmannsröben, Hans-Gerd
T1  - In-situ LIF analysis of biological and petroleum-based hydraulic oils on soil
N2  - Absorption and fluorescence properties of 4 hydraulic oils (3 biological and 1 petroleum-based) were investigated. In-situ LIF (laser-induced fluorescence) analysis of the oils on a brown sandy loam soil was performed. With calibration, quantitative detection was achieved. Estimated limits of detection were below ca. 500 mg/kg for the petroleum-based oil and ca. 2000 mg/kg for one biological oil. A semi-quantitative classification scheme is proposed for monitoring of the biological oils. This approach was applied to investigate the migration of a biological oil in soil-containing compartments, namely a soil column and a soil bed.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 011 
KW  - in-situ
KW  - optical oil sensor
KW  - lubricants
KW  - hydraulic oils
KW  - soil
KW  - laser induced
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12268
ER  - 
TY  - GEN
A1  - Leimkuhler, Benedict
A1  - Reich, Sebastian
T1  - Symplectic integration of constrained Hamiltonian systems
N2  - A Hamiltonian system in potential form (formula in the original abstract) subject to smooth constraints on q can be viewed as a Hamiltonian system on a manifold, but numerical computations must be performed in Rn. In this paper methods which reduce "Hamiltonian differential algebraic equations" to ODEs in Euclidean space are examined. The authors study the construction of canonical parameterizations or local charts as well as methods based on the construction of ODE systems in the space in which the constraint manifold is embedded which preserve the constraint manifold as an invariant manifold. In each case, a Hamiltonian system of ordinary differential equations is produced. The stability of the constraint invariants and the behavior of the original Hamiltonian along solutions are investigated both numerically and analytically.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 032 
KW  - differential-algebraic equations
KW  - constrained Hamiltonian systems
KW  - canonical discretization schemes
KW  - symplectic methods
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-15653
ER  - 
TY  - GEN
A1  - Lau, Steffen
A1  - Salffner, Katharina
A1  - Löhmannsröben, Hans-Gerd
T1  - Isotopic resolution of carbon monoxide and carbon dioxide by NIR diode laser spectroscopy
N2  - Near-infrared (NIR) absorption spectroscopy with tunable diode lasers allows the simultaneous detection of the three most important isotopologues of carbon dioxide (<SUP>12</SUP>CO<SUB>2</SUB>, <SUP>13</SUP>CO<SUB>2</SUB>, <SUP>12</SUP>C<SUP>18</SUP>O<SUP>16</SUP>O) and carbon monoxide (<SUP>12</SUP>CO, <SUP>13</SUP>CO, <SUP>12</SUP>C<SUP>18</SUP>O). The flexible and compact fiber-optic tunable diode laser absorption spectrometer (TDLAS) allows selective measurements of CO<SUB>2</SUB> and CO with high isotopic resolution without sample preparation since there is no interference with water vapour. For each species, linear calibration plots with a dynamic range of four orders of magnitude and detection limits (LOD) in the range of a few ppm were obtained utilizing wavelength modulation spectroscopy (WMS) with balanced detection in a Herriott-type multipass cell. The high performance of the apparatus is illustrated by fill-evacuation-refill cycles.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 017 
KW  - Isotop
KW  - Kohlenmonoxid
KW  - Kohlendioxid
KW  - Diodenlaserspektroskopie
KW  - isotope
KW  - carbon monoxide
KW  - carbon dioxide
KW  - diode laser spectroscopy
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10135
ER  - 
TY  - GEN
A1  - Lattemann, Christoph
A1  - Stieglitz, Stefan
T1  - Framework for Governance in Open Source Communities
N2  - In recent years, the development of software in open source communities has attracted immense attention from research and practice. The idea of commercial quality, free software, and open source code accelerated the development of well-designed open source software such as Linux, Apache tools, or Perl. Intrinsic motivation, group identification processes, learning, and career concerns are the key drivers for a successful cooperation among the participants. These factors and most mechanisms of control, coordination, and monitoring forms of open source communities can hardly be explained by traditional organizational theories. In particular, the micro and macro structures of open source communities and their mode of operation are hardly compatible with the central assumption of the New Institutional Theory, like opportunistic behavior. The aim of this contribution is to identify factors that sustain the motivation of the community members over the entire life cycle of an open source project. Adequate coordination and controlling mechanisms for the governance in open source communities may be extracted.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - paper 013 
KW  - Governance
KW  - Open Source
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-19941
SN  - 1867-5808
ER  - 
TY  - GEN
A1  - Lattemann, Christoph
A1  - Kupke, Sören
A1  - Stieglitz, Stefan
A1  - Fetscherin, Marc
T1  - The governance of virtual corporations
N2  - The concept of the virtual corporation (VC), which describes a modern form of collaboration among organizations, was introduced in the scientific discussion in the mid 1990th. The practice shows that VCs need new forms of governance because the traditional mechanisms of control, management, and steering are hardly applicable. Until now there is only a few research related to the question how to govern VC. The main problems to govern a VC are to coordinate the communication among dispersed partners and to motivate employees to actively involve themselves into the network. Open source projects are confronted with similar problems. As several governance mechanisms are already analyzed in this context, the authors analyze and adopt governance concepts from open source projects to extract a governance framework for virtual corporations. This new approach leads to innovative insights in governing virtual corporations by using community techniques as an appropriate way for communication and collaboration purposes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - paper 016 
KW  - virtual corporation
KW  - governance
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-19988
SN  - 1867-5808
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  - GEN
A1  - Laschewsky, André
A1  - Ringsdorf, H.
A1  - Schneider, J.
T1  - Oriented supramolecular systems-polymeric monolayers and multilayers from prepolymerized amphiphiles
N2  - Oriented polymeric membranes were originally prepared by polymerization or polycondensation of preoriented monomers. The introduction of hydrophilic spacer groups into the polymeric amphiphiles allowed the formation of highly ordered systems (monolayers, liposomes, multilayers) from prepolymerized amphiphiles: due to the partial decoupling of the different mobilities and orientation tendencies of the polymer chain and the amphiphilic side groups, these polymers are able to self-organize. In monolayer experiments the high order of these membranes could be demonstrated by their surface pressure area-diagrams. In addition the combination of order and mobility of these spacer groups containing polymeric amphiphiles allowed the formation of Langmuir-Blodgett-multilyers with a high layer correlation. Thus, disturbancies in highly oriented layers can be avoided normally taking place during the polymerization reaction (e.g. contractions) or oriented monomeric layers.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 056 
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17131
ER  - 
TY  - GEN
A1  - Laschewsky, André
A1  - Ringsdorf, H.
A1  - Schmidt, G.
A1  - Schneider, J.
T1  - Self-organization of polymeric lipids with hydrophilic spacers in side groups and main chain : investigation in monolayers and multilayers
N2  - Several polymerizable lipids were synthesized and polymerized to amphiphilic homopolymers and to copolymers with the help of hydrophilic comonomers. The self-organization of these polymeric lipids was investigated in monolayers and Langmuir-Blodgett multilayers. The self-organization of these polymers in model membranes is due to hydrophilic spacer groups in the amphiphilic side groups as well as to hydrophilic spacer groups in the polymer backbone. Thus, highly ordered monolayers and LB-multilayers are easily obtained.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 057 
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17147
ER  - 
TY  - GEN
A1  - Laschewsky, André
A1  - Ringsdorf, H.
A1  - Schmidt, G.
T1  - Polymerization of hydrocarbon and fluorocarbon amphiphiles in Langmuir-Blodgett multilayers
N2  - Langmuir-Blodgett multilayers of polymerizable carboxylic acids with hydrocarbon or fluorocarbon chains were prepared. The multilayers were polymerized by UV light and the reactions were studied by UV/visible spectroscopy. The polyreactions strongly influence the multilayer structures which were investigated by X-ray small-angle scattering and scanning electron microscopy. The spreading behaviour of the monomers, the preparation of multilayers, their reactivities in multilayers and structural effects caused by the polyreactions are discussed with regard to the hydrophilic head groups, the polymerizable groups and the hydrophobic chains.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 055 
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17096
ER  -