TY - THES A1 - Abel, Markus T1 - Turbulent flows : transport, analysis and modeling Y1 - 2005 CY - Potsdam ER - TY - JOUR A1 - Abel, Markus A1 - Ahnert, Karsten A1 - Kurths, R. A1 - Mandelj, S. T1 - Additive nonparametric reconstruction of dynamical systems from time series N2 - We present a nonparametric way to retrieve an additive system of differential equations in embedding space from a single time series. These equations can be treated with dynamical systems theory and allow for long-term predictions. We apply our method to a modified chaotic Chua oscillator in order to demonstrate its potential Y1 - 2005 SN - 1063-651X ER - TY - BOOK A1 - Aizenberg, Lev A. A1 - Tarkhanov, Nikolai Nikolaevich T1 - Stable expansions in homogeneous polynomials T3 - Preprint / Universität Potsdam, Institut für Mathematik, Arbeitsgruppe Partiell Y1 - 2005 SN - 1437-739X PB - Univ. CY - Potsdam ER - TY - INPR A1 - Aizenberg, Lev A. A1 - Tarkhanov, Nikolai Nikolaevich T1 - Stable expansions in homogeneous polynomials N2 - An expansion for a class of functions is called stable if the partial sums are bounded uniformly in the class. Stable expansions are of key importance in numerical analysis where functions are given up to certain error. We show that expansions in homogeneous functions are always stable on a small ball around the origin, and evaluate the radius of the largest ball with this property. T3 - Preprint - (2005) 16 Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29925 ER - TY - JOUR A1 - Alarcon, Julio A1 - Alderete, Joel B. A1 - Aguila, Sergio A1 - Peter, Martin G. T1 - Regio and stereoselective hydroxylation of alpha-agarofuran by biotransformation of rhizopus nigricans N2 - A new synthesis of 9 alpha-hydroxy-alpha-agarofuran (6 alpha) is described, using a microbiological hydroxylation alpha-agarofuran (5) as the key reaction. The stereochemistry of the biohydroxylation was determined on the basis of a NOESY-experiment and GIAO calculations at the B3LYP/cc-pVDZ level. A strong gamma-effect was observed at C15 of the agarofuran ring which was correctly predicted by the GIAO-B3LYP calculations Y1 - 2005 ER - TY - THES A1 - Ali, Abu Md. Imroz T1 - Morphology control in nanoscopic composite polymer particles Y1 - 2005 CY - Potsdam ER - TY - JOUR A1 - Allefeld, Carsten T1 - Phase vs. amplitude correlations in event-related potentials Y1 - 2005 SN - 0898-929X ER - TY - JOUR A1 - Allefeld, Carsten A1 - Frisch, Stefan A1 - Schlesewsky, Matthias T1 - Detection of early cognitive processing by event-related phase synchronization analysis N2 - In order to investigate the temporal characteristics of cognitive processing, we apply multivariate phase synchronization analysis to event-related potentials. The experimental design combines a semantic incongruity in a sentence context with a physical mismatch (color change). In the ERP average, these result in an N400 component and a P300-like positivity, respectively. Synchronization analysis shows an effect of global desynchronization in the theta band around 288 ms after stimulus presentation for the semantic incongruity, while the physical mismatch elicits an increase of global synchronization in the alpha band around 204 ms. Both of these effects clearly precede those in the ERP aver-age. Moreover, the delay between synchronization effect and ERP component correlates with the complexity Of the cognitive processes. (C) 2005 Lippincott Williams Wilkins Y1 - 2005 SN - 0959-4965 ER - TY - GEN A1 - Allefeld, Carsten A1 - Frisch, Stefan A1 - Schlesewsky, Matthias T1 - Detection of early cognitive processing by event-related phase synchronization analysis N2 - In order to investigate the temporal characteristics of cognitive processing, we apply multivariate phase synchronization analysis to event-related potentials. The experimental design combines a semantic incongruity in a sentence context with a physical mismatch (color change). In the ERP average, these result in an N400 component and a P300-like positivity, respectively. The synchronization analysis shows an effect of global desynchronization in the theta band around 288ms after stimulus presentation for the semantic incongruity, while the physical mismatch elicits an increase of global synchronization in the alpha band around 204ms. Both of these effects clearly precede those in the ERP average. Moreover, the delay between synchronization effect and ERP component correlates with the complexity of the cognitive processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 074 KW - phase synchronization KW - coherence KW - semantic incongruity KW - color change KW - N400 KW - P300 KW - theta KW - alpha Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-20126 ER - TY - THES A1 - Andersen, Audrée T1 - Surfactant dynamics at interfaces : a series of second harmonic generation experiments T1 - Surfactant Dynamik an Grenzflächen : eine Studie über SHG-Experimente N2 - Adsorption layers of soluble surfactants enable and govern a variety of phenomena in surface and colloidal sciences, such as foams. The ability of a surfactant solution to form wet foam lamellae is governed by the surface dilatational rheology. Only systems having a non-vanishing imaginary part in their surface dilatational modulus, E, are able to form wet foams. The aim of this thesis is to illuminate the dissipative processes that give rise to the imaginary part of the modulus. There are two controversial models discussed in the literature. The reorientation model assumes that the surfactants adsorb in two distinct states, differing in their orientation. This model is able to describe the frequency dependence of the modulus E. However, it assumes reorientation dynamics in the millisecond time regime. In order to assess this model, we designed a SHG pump-probe experiment that addresses the orientation dynamics. Results obtained reveal that the orientation dynamics occur in the picosecond time regime, being in strong contradiction with the two states model. The second model regards the interface as an interphase. The adsorption layer consists of a topmost monolayer and an adjacent sublayer. The dissipative process is due to the molecular exchange between both layers. The assessment of this model required the design of an experiment that discriminates between the surface compositional term and the sublayer contribution. Such an experiment has been successfully designed and results on elastic and viscoelastic surfactant provided evidence for the correctness of the model. Because of its inherent surface specificity, surface SHG is a powerful analytical tool that can be used to gain information on molecular dynamics and reorganization of soluble surfactants. They are central elements of both experiments. However, they impose several structural elements of the model system. During the course of this thesis, a proper model system has been identified and characterized. The combination of several linear and nonlinear optical techniques, allowed for a detailed picture of the interfacial architecture of these surfactants. N2 - Amphiphile vereinen zwei gegensätzliche Strukturelemente in einem Molekül, eine hydrophile Kopfgruppe und ein hydrophobe, meist aliphatische Kette. Aufgrund der molekularen Asymmetrie erfolgt eine spontane Adsorption an der Wasser-Luft Grenzfläche. Die Adsorptionsschicht verändert die makroskopischen Eigenschaften des Materials, z.B. die Grenzflächenspannung wird erniedrigt. Amphiphile sind zentrale Bauelemente der Kolloid- und Grenzflächenforschung, die Phänomene, wie Schäume ermöglichen. Eine Schaumlamelle besteht aus einem dünnen Wasserfilm, der durch zwei Adsorptionsschichten stabilisiert wird. Die Stabilität der Lamelle wird durch die Grenzflächenrheologie entscheidend geprägt. Die wesentliche makroskopische Größe in diesem Zusammenhang ist das so genannte Grenzflächendilatationsmodul E. Es beschreibt die Fähigkeit des Systems die Gleichgewichtsgrenzflächenspannung nach einer Expansion oder Dilatation der Adsorptionschicht wieder herzustellen. Das Modul E ist eine komplexe Größe, in dem der Imaginärteil direkt mit der Schaumstabilität korreliert. Diese Arbeit widmet sich der Grenzflächenrheologie. In der Literatur werden zwei kontroverse Modelle zur Interpretation dieser Größe diskutiert. Diese Modelle werden experimentell in dieser Arbeit überprüft. Dies erfordert die Entwicklung neuer experimenteller Aufbauten basierend auf nichtlinearen, optischen Techniken. Mit diesen Experimenten konnte eines der Modelle bestätigt werden. KW - Tensid KW - Grenzflächenchemie KW - Nichtlineare Spektroskopie KW - Oscillating Bubble KW - surfactants KW - nonlinear optics KW - surface rheology KW - air-water interface KW - oscillating bubble Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6553 ER - TY - THES A1 - Andersen, Katja ED - Gronau, Norbert T1 - Design and use patterns of adaptability in enterprise systems T2 - Reihe Wirtschaftsinformatik : technische und organisatorische Gestaltungsoptionen Y1 - 2005 SN - 3-936771-78-2 VL - 5 PB - Gito-Verl. CY - Berlin ER - TY - THES A1 - Andersen, Morten I. T1 - Low-mass pre-main-sequence stars in the massive star clusters NGC 3603 and 30 Dor Y1 - 2005 ER - TY - JOUR A1 - Andresen, Katja A1 - Gronau, Norbert T1 - Seeking Optimal IT-Strategies by the Determination of Adaptability in Domain-Specific Software Applications N2 - Adaptability of information systems has become a substantial competition factor. Today's insufficient methodical support for the realization of adaptability frequently leads to unused potentials of deployed information technology in enterprises. In this contribution a procedure is presented, which addresses the demand to determine the necessary adaptability of an enterprise related to its surrounding environmental environment. Y1 - 2005 UR - http://wi.uni-potsdam.de ER - TY - JOUR A1 - Andresen, Katja A1 - Gronau, Norbert T1 - An Approach to Increase Adaptability in ERP Systems N2 - The concept of adaptability has been widely recognised as research field in recent years. Business information systems play a key part in terms of business performance. Adaptability of information systems therefore is a primary goal of vendors and end-users. However, so far concepts that help to determine the adaptability of Information Systems are missing. Based on research results of the project CHANGE1 this contribution presents an integrated process model addressing the problem and a possible solution. Y1 - 2005 UR - http://wi.uni-potsdam.de ER - TY - JOUR A1 - Andrianov, Igor V. A1 - Klamroth, Tillmann A1 - Saalfrank, Peter A1 - Bovensiepen, U. A1 - Gahl, Cornelius A1 - Wolf, M. M. T1 - Quantum theoretical study of electron solvation dynamics in ice layers on a Cu(111) surface N2 - Recent experiments using time- and angle-resolved two-photon photoemission (2PPE) spectroscopy at metal/polar adsorbate interfaces succeeded in time-dependent analysis of the process of electron solvation. A fully quantum mechanical, two-dimensional simulation of this process, which explicitly includes laser excitation, is presented here, confirming the origin of characteristic features, such as the experimental observation of an apparently negative dispersion. The inference of the spatial extent of the localized electron states from the angular dependence of the 2PPE spectra has been found to be non-trivial and system-dependent. (C) 2005 American Institute of Physics Y1 - 2005 SN - 0021-9606 ER - TY - JOUR A1 - Anger, Christian A1 - Gebser, Martin A1 - Linke, Thomas A1 - Neumann, Andre A1 - Schaub, Torsten H. T1 - The nomore++ approach to answer set solving Y1 - 2005 UR - http://www.cs.uni-potsdam.de/wv/pdfformat/angelinesc05c.pdf ER - TY - JOUR A1 - Anger, Christian A1 - Gebser, Martin A1 - Linke, Thomas A1 - Neumann, Andre A1 - Schaub, Torsten H. T1 - The nomore++ approach to answer set solving Y1 - 2005 UR - http://www.cs.uni-potsdam.de/wv/pdfformat/angelinesc05c.pdf ER - TY - JOUR A1 - Anger, Christian A1 - Konczak, Kathrin A1 - Linke, Thomas A1 - Schaub, Torsten H. T1 - A Glimpse of Answer Set Programming Y1 - 2005 UR - http://www.cs.uni-potsdam.de/~konczak/Papers/ankolisc05.pdf SN - 0170-4516 ER - TY - JOUR A1 - Apitz, Sabine E. A1 - Bell, Elanor M. A1 - Damgaard, Lars A1 - Gilbert, Franck A1 - Glud, R A1 - Hall, P. O. J. A1 - Kershaw, P. J. A1 - Nickel, L A1 - Parker, R A1 - Rabouille, Christophe A1 - Shimmield, Grahamm A1 - Solan, Martin A1 - Soltwedel, Thomas A1 - Spagnoli, Federico A1 - Witte, Ursula T1 - Coastal Ocean Benthic Observatories (COBO) : integrated tools for the in situ observation and study of benthic ecosystem biogeochemical processes Y1 - 2005 ER - TY - THES A1 - Arrivault, Stéphanie T1 - Functional characterization of Arabidopsis thaliana MTP3, a putative metal transport protein of the cation diffusion facilitator (CDF) family Y1 - 2005 ER - TY - THES A1 - Asfaw, Mesfin T1 - Adhesion of multi-component membbranes and strings Y1 - 2005 CY - Potsdam ER - TY - THES A1 - Aulbert, Carsten T1 - Finding millisecond binary pulsars in 47 tucanae by applying the hough transformation to radio data Y1 - 2005 CY - Potsdam ER - TY - JOUR A1 - Baake, Ellen A1 - Baake, Michael A1 - Bovier, Anton A1 - Klein, Markus T1 - An asymptotic maximum principle for essentially linear evolution models N2 - Recent work on mutation-selection models has revealed that, under specific assumptions on the fitness function and the mutation rates, asymptotic estimates for the leading eigenvalue of the mutation-reproduction matrix may be obtained through a low-dimensional maximum principle in the limit N --> infinity (where N, or N-d with d greater than or equal to 1, is proportional to the number of types). In order to extend this variational principle to a larger class of models, we consider here a family of reversible matrices of asymptotic dimension N-d and identify conditions under which the high-dimensional Rayleigh-Ritz variational problem may be reduced to a low-dimensional one that yields the leading eigenvalue up to an error term of order 1/N. For a large class of mutation-selection models, this implies estimates for the mean fitness, as well as a concentration result for the ancestral distribution of types Y1 - 2005 SN - 0303-6812 ER - TY - JOUR A1 - Bagnich, Sergey A. A1 - Bassler, H. A1 - Neher, Dieter T1 - Exciton dynamics in ladder-type methyl-poly(para-phenylene) doped with phosphorescent dyes N2 - The luminescence of a ladder-type methyl-poly(para-phenylene) (MeLPPP) doped with platinum-porphyrin dye PtOEP covering the concentration 10(-3)-5% by weight has been measured employing cw and transient techniques. Upon excitation into the range of absorption of the host, strong phosphorescence of the dopant is observed. Possible ways of populating the dopant triplet state are considered. (c) 2004 Elsevier B.V. All rights reserved Y1 - 2005 SN - 0022-2313 ER - TY - JOUR A1 - Bahrs, Julian A1 - Bogen, Jane A1 - Schmid, Simone T1 - Pattern based Analysis and Redesign of Knowledge Intensive Business Processes N2 - Knowledge management aims at increasing efficiency of knowledge related work. The Knowledge Modelling and Description language offers a modelling and analysis approach to knowledge intensive business processes, which results in improved processes. Y1 - 2005 UR - http://wi.uni-potsdam.de ER - TY - JOUR A1 - Bahrs, Julian A1 - Müller, Claudia T1 - Modelling and analysis of knowledge intensive business processes N2 - This contribution gives an overview on the scientific discipline of business process oriented knowledge management. It presents results and recent developments as well as an overview of this year's workshop on Modelling and Analysis of Knowledge Intensive Business Processes (KiBP 2005) Y1 - 2005 ER - TY - JOUR A1 - Ballato, Paolo A1 - Cruciani, G. A1 - Dalconi, M. C. A1 - Fabbri, B. A1 - Macchiarola, M. T1 - Mineralogical study of historical bricks from the Great Palace of the Byzantine Emperors in Istanbul based on powder X-ray diffraction data N2 - This study concerns the Quantitative Phase Analysis (QPA) of historical bricks coming from the complex of the Great Palace of the Byzantine Emperors in Istanbul. The studied samples are characterised by different chemical compositions (low and high calcium content), variable firing temperatures and different amounts of soluble salts as damage products. In the low-Ca samples, the decrease of the phyllosilicate content (from 23.4 to 6.9 wt%) is associated to the increase of the amorphous fraction (from 24 to 48%). This clear negative correlation between the phyllosilicate content and the amorphous fraction indicates that in low-Ca systems vitrification processes are overwhelming with respect to nucleation and recrystallisation processes. By contrast, high-Ca samples present newly formed Ca(Mg) silicates (diopside from 5.7 to 27.2%; anorthite from 1.4 to 8.7%) and aluminium silicates (gehlenite only in two samples, 6.2 and 7.7%) associated to the decrease of quartz (from 27.7 to 11.5%), phyllosilicate (from 6.5% until complete break down) and amorphous (from 30 to 14%) phase fractions. These findings support the role played by the CaO(MgO) content deriving from carbonates decomposition which reacts with Al2O3 and SiO2 oxides from dehydroxylated clay minerals and quartz grains. The above results have been obtained by X-ray powder diffraction data using the combined Rietveld refinement - internal standard method in order to estimate both the crystalline and the amorphous phase fractions. In addition, the coexistence of two distinct plagioclases in high-Ca samples was modelled as follows: a primary albite, which tends to incorporate Ca during the firing process as demonstrated by the increasing of gamma crystallographic angle, and a newly formed anorthite. Finally, by difference between the X-ray fluorescence data and the chemical compositions inferred by QPA, it proved possible to roughly estimate the residual chemical composition attributable to the amorphous fraction. On the basis of our data, we believe that Rietveld refinement combined with the internal standard method represent a powerful tool to better characterise complex polycrystalline and amorphous mixture as in the case of historical bricks Y1 - 2005 SN - 0935-1221 ER - TY - JOUR A1 - Banning, Anja A1 - Deubel, S. A1 - Kluth, Dirk A1 - Zhou, Z. W. A1 - Brigelius-Flohé, Regina T1 - The GI-GPx gene is a target for Nrf2 N2 - The gastrointestinal glutathione peroxidase (GI-GPx, GPx2) is a selenoprotein that was suggested to act as barrier against hydroperoxide absorption but has also been implicated in the control of inflammation and malignant growth. In CaCo-2 cells, GI-GPx was induced by t-butyl hydroquinone (tBHQ) and sulforaphane (SFN), i.e., "antioxidants" known to activate the "antioxidant response element" (ARE) via electrophilic thiol modification of Keap1 in the Nrf2/ Keap1 system. The functional significance of a putative ARE in the GI-GPx promoter was validated by transcriptional activation of reporter gene constructs upon exposure to electrophiles (tBHQ, SFN, and curcumin) or overexpression of Nrf2 and by reversal of these effects by mutation of the ARE in the promoter and by overexpressed Keap1. Binding of Nrf2 to the ARE sequence in authentic gpx2 was corroborated by chromatin immunoprecipitation. Thus, the presumed natural antioxidants sulforaphane and curcumin may exert their anti-inflammatory and anticarcinogenic effects not only by induction of phase 2 enzymes but also by the up-regulation of the selenoprotein GI-GPx Y1 - 2005 SN - 0270-7306 ER - TY - JOUR A1 - Baptista, Murilo da Silva A1 - Kraut, Suso A1 - Grebogi, Celso T1 - Poincare recurrence and measure of hyperbolic and nonhyperbolic chaotic attractors N2 - We study Poincare recurrence of chaotic attractors for regions of finite size. Contrary to the standard case, where the size of the recurrent regions tends to zero, the measure is no longer supported solely by unstable periodic orbits of finite length inside it, but also by other special recurrent trajectories, located outside that region. The presence of the latter leads to a deviation of the distribution of the Poincare first return times from a Poissonian. Consequently, by taking into account the contribution of these special recurrent trajectories, a corrected estimate of the measure is obtained. This has wide experimental implications, as in the laboratory all returns can exclusively be observed for regions of finite size, and only unstable periodic orbits of finite length can be detected Y1 - 2005 SN - 0031-9007 ER - TY - JOUR A1 - Baptista, Murilo da Silva A1 - Kurths, Jürgen T1 - Chaotic channel N2 - This work combines the theory of chaotic synchronization with the theory of information in order to introduce the chaotic channel, an active medium formed by connected chaotic systems. This subset of a large chaotic net represents the path along which information flows. We show that the possible amount of information exchange between the transmitter, where information enters the net, and the receiver, the destination of the information, is proportional to the level of synchronization between these two special subsystems Y1 - 2005 SN - 1539-3755 ER - TY - JOUR A1 - Baptista, Murilo da Silva A1 - Pereira, Tiago A1 - Sartorelli, J. C. A1 - Caldas, Ibere Luiz A1 - Kurths, Jürgen T1 - Non-transitive maps in phase synchronization N2 - Concepts from Ergodic Theory are used to describe the existence of special non-transitive maps in attractors of phase synchronous chaotic oscillators. In particular, it is shown that, for a class of phase-coherent oscillators, these special maps imply phase synchronization. We illustrate these ideas in the sinusoidally forced Chua's circuit and two coupled Rossler oscillators. Furthermore, these results are extended to other coupled chaotic systems. In addition, a phase for a chaotic attractor is defined from the tangent vector of the flow. Finally, it is discussed how these maps can be used for the real-time detection of phase synchronization in experimental systems. (c) 2005 Elsevier B.V. All rights reserved Y1 - 2005 ER - TY - JOUR A1 - Barbier, Guillaume A1 - Oesterhelt, Christine A1 - Larson, Matthew D. A1 - Halgren, Robert G. A1 - Wilkerson, Curtis A1 - Garavito, Michael R. A1 - Benning, Christoph A1 - Weber, Andreas P. M. T1 - Comparative genomics of two closely related unicellular thermo-acidophilic red algae, Galdieria sulphuraria and Cyanidioschyzon merolae, reveals the molecular basis of the metabolic flexibility of Galdieria sulphuraria and sigant differences in carbohydrate metabolism of both algae N2 - Unicellular algae serve as models for the study and discovery of metabolic pathways, for the functional dissection of cell biological processes such as organellar division and cell motility, and for the identification of novel genes and gene functions. The recent completion of several algal genome sequences and expressed sequence tag collections and the establishment of nuclear and organellar transformation methods has opened the way for functional genomics approaches using algal model systems. The thermo-acidophilic unicellular red alga Galdieria sulphuraria represents a particularly interesting species for a genomics approach owing to its extraordinary metabolic versatility such as heterotrophic and mixotrophic growth on more than 50 different carbon sources and its adaptation to hot acidic environments. However, the ab initio prediction of genes required for unknown metabolic pathways from genome sequences is not trivial. A compelling strategy for gene identification is the comparison of similarly sized genomes of related organisms with different physiologies. Using this approach, candidate genes were identified that are critical to the metabolic versatility of Galdieria. Expressed sequence tags and high-throughput genomic sequence reads covering >70% of the G. sulphuraria genome were compared to the genome of the unicellular, obligate photoautotrophic red alga Cyanidioschyzon merolae. More than 30% of the Galdieria sequences did not relate to any of the Cyandioschyzon genes. A closer inspection of these sequences revealed a large number of membrane transporters and enzymes of carbohydrate metabolism that are unique to Galdieria. Based on these data, it is proposed that genes involved in the uptake of reduced carbon compounds and enzymes involved in their metabolism are crucial to the metabolic flexibility of G. sulphuraria Y1 - 2005 ER - TY - JOUR A1 - Barden, Marco A1 - Rix, Hans-Walter A1 - Somerville, Rachel S. A1 - Bell, Eric F. A1 - Häußler, Boris A1 - Peng, Chen Y. A1 - Borch, Andrea A1 - Beckwith, Steven V. W. A1 - Caldwell, John A. R. A1 - Heymans, Catherine A1 - Jahnke, Knud A1 - Jogee, Shardha A1 - McIntosh, Daniel H. A1 - Meisenheimer, Klaus A1 - Sanchez, Sebastian F. A1 - Wisotzki, Lutz A1 - Wolf, C. T1 - GEMS : the surface brightness and surface mass density evolution of disk galaxies N2 - We combine HST imaging from the GEMS ( Galaxy Evolution from Morphologies and SEDs) survey with photometric redshifts from COMBO-17 to explore the evolution of disk-dominated galaxies since z less than or similar to 1.1. The sample is composed of all GEMS galaxies with Sersic indices n < 2.5, derived from fits to the galaxy images. We account fully for selection effects through careful analysis of image simulations; we are limited by the depth of the redshift and HST data to the study of galaxies with M-V less than or similar to -20, or equivalently, log (M/M-circle dot) greater than or similar to 10. We find strong evolution in the magnitude-size scaling relation for galaxies with M-V less than or similar to -20, corresponding to a brightening of similar to 1 mag arcsec(-2) in rest-frame V band by z similar to 1. Yet disks at a given absolute magnitude are bluer and have lower stellar mass-to-light ratios at z similar to 1 than at the present day. As a result, our findings indicate weak or no evolution in the relation between stellar mass and effective disk size for galaxies with log (M/M-circle dot) greater than or similar to 10 over the same time interval. This is strongly inconsistent with the most naive theoretical expectation, in which disk size scales in proportion to the halo virial radius, which would predict that disks are a factor of 2 denser at fixed mass at z similar to 1. The lack of evolution in the stellar mass-size relation is consistent with an "inside-out'' growth of galaxy disks on average (galaxies increasing in size as they grow more massive), although we cannot rule out more complex evolutionary scenarios Y1 - 2005 ER - TY - THES A1 - Bari, Rajendra P. T1 - Molecular characterization of phosphate signaling in arabidopsis thaliana Y1 - 2005 CY - Potsdam ER - TY - JOUR A1 - Baron, Frank T1 - From Alexander von Humboldt to Frederic Edwin Church BT - Voyages of Scientific Exploration and Creativity JF - HIN : Alexander von Humboldt im Netz ; international review for Humboldtian studies N2 - Stephen Jay Gould wrote recently that “when Church began to paint his great canvases, Alexander von Humboldt may well have been the world’s most famous and influential intellectual.” Humboldt’s influence in the case of the landscape artist Church is especially interesting. If we examine the precise relationship between the German explorer and his American admirer, we gain an insight into how Humboldt transformed Church’s life and signaled a new phase in the career of the artist. Church retraced Humboldt’s travels in Ecuador and in Mexico. If we compare the texts available to Church and the comparison of Church’s paintings and the texts and images of Humboldt’s works we can arrive at new perspectives on Humboldt’s extraordinary influence on American landscape painting in the nineteenth century. N2 - Der amerikanische Wissenschaftshistoriker Stephen Jay Gould stellte fest, daß Alexander von Humboldt um die Mitte des neunzehnten Jahrhunderts vielleicht der berühmteste und einflußreichste Intellektuelle gewesen sei. Zu diesem Zeitpunkt bietet Humboldts Einfluß auf den Landschaftsmaler Church einen besonders interessanten Fall. Wenn wir die Beziehungen zwischen dem deutschen Entdeckungsreisenden und seinem amerikanischen Bewunderer näher betrachten, erfahren wir, wie die Impulse von Humboldt das Leben und die Karriere des Künstlers in ganz neue Richtungen führten. Church besuchte mehrere von Humboldt beschriebene Orte in Ekuador und Mexiko. Der Vergleich der veröffentlichten Texte und Abbildungen Humboldts mit den Gemälden von Church liefert neue Perspektiven, in welcher Weise Humboldt die amerikanische Landschaftsmalerei des neunzehnten Jahrhunderts beeinflußt hat. N2 - El historiador norteamericano Stephen Jay Gould afirmó que Alexander von Humboldt fue posiblemente el más famoso e influyente intelectual a mediados del siglo XIX. Para ese entonces, la influencia de Humboldt sobre el paisajista Church ofrece un caso especialmente interesante. Si analizamos las relaciones entre el explorador alemán y su admirador norteamericano con mayor detalle, nos enteramos cómo los impulsos de Humboldt llevaron la vida y carrera del artista por carriles totalmente nuevos. Church visitó varios de los lugares descritos por Humboldt en Ecuador y México. La comparación de los textos e ilustraciones publicados de Humboldt con las pinturas de Church ofrece nuevas perspectivas acerca de la extraordinaria influencia de Humboldt en la pintura paisajista norteamericana del siglo XIX. KW - bildende Kunst KW - Humboldt als Vorbild KW - Frederic Edwin Church Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-35194 SN - 1617-5239 SN - 2568-3543 VL - VI IS - 10 SP - 7 EP - 20 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Bauer, Niclas Alexandre T1 - Carbon capture and sequestration : an option to buy time? T1 - Kohlenstoffabscheidung und Sequestrierung : eine Option um Zeit zu kaufen? N2 - The thesis assesses the contribution of technology option of Carbon Capture and Sequestration (CCS) to climate change mitigation. CCS means that CO2 is captured at large industrial facilities and sequestered in goelogical structures. The technology uses the endogenous growth model MIND. Herein the various climate change mitigation options of reducing economic growth, increasing energy efficiency, changing the energy mix and CCS are assessed simultaneously. An important question is whether CCS is a temporary or long-term solution. The results show that in the middle of the 21st century CCS has its peak contribution, which allows prolonged use of relatively cheap fossil energy carriers. However, this leads to delayed introduction of renewable energy carriers. The technology path ways are accombined with different costs of climate change mitigation. The use of CCS delays and reduces the costs of climate change mitigation. However, the delayed introduction of renewable energy carriers leads to reduced technological learning, which induces higher costs in the longer term. All in all the temporary use of CCS reduces the costs of climate change mitigation costs. The result is robust, which is tested with various uncertainty analysis. N2 - Die Arbeit befasst sich mit der Bewertung der technischen Option zum Klimaschutz CO2 an grossen industriellen Anlagen abzufangen und in geologischen Lagerstätten zu speichern. Die Technologiebewertung wird mit Hilfe des endogenen Wachstummodells MIND untersucht. Darin werden die Klimaschutzoptionen geringere wirtschaftliche Entwicklung, Steigerung der Energieeffizienz, Veränderung des Energiemixes und eben CO2 Abscheidung simultan bewertet. Eine wichtige Frage ist ob die Abscheidung von CO2 eine langfristige oder eine Zwischenlösung ist. Es zeigt sich, dass sie um die Mitte des 21ten Jahrhunderts ihren grössten Beitrag zum Klimaschutz leistet und die Nutzung der relativ kostengünstigen fossilen Energieträger verlängert. Das führt zu einer späteren Einführung erneuerbarer Energietechnologieen. Mit diesen unterschiedlichen Technologiepfaden gehen auch verschiedene ökonomische Kostenverläufe des Klimaschutzes einher. Die Verwendung von CO2 Abscheidung verschiebt die Kosten in die Zukunft und drückt ihre Spitze. Da es aber gleichzeitig zu geringerer Technologieentwicklung bei erneuerbaren Energieen führt entstehen wiederum Kosten. Unterm Strich lohnt sich die Einführung der CO2 Abscheidung als temporärer Beitrag zum Klimaschutz. Dieses Ergebnis konnte mit einer Reihe von Unsicherheitsanalysen erhärtet werden. KW - Endogenes Wirtschaftswachstum KW - Klimaschutz KW - Technologiebewertung KW - Edongenous Economic Growth KW - Climate Change Mitigation KW - Technology Assessment Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6544 ER - TY - JOUR A1 - Baumgaertel, Hellmut A1 - Grundling, H. T1 - Superselection in the presence of constraints N2 - Superselection and constraints occur together in many gauge theories, and here we begin a study of such systems. Our main focus will be to analyze compatibility questions between constraining and superselection, and we will develop an example modelled on QED in which our framework is realized. We proceed from a generalization of Doplicher- Roberts superselection theory to the case of the nontrivial center, and a set of Dirac quantum constraints and find conditions under which the superselection structures will survive constraining in some form. This involves an analysis of the restriction and factorization of superselection structures. (c) 2005 American Institute of Physics Y1 - 2005 SN - 0022-2488 ER - TY - THES A1 - Becker, Christian T1 - On the Riemannian geometry of Seiberg-Witten moduli spaces T1 - Über die Riemannsche Geometrie von Seiberg-Witten-Modulräumen N2 - In this thesis, we give two constructions for Riemannian metrics on Seiberg-Witten moduli spaces. Both these constructions are naturally induced from the L2-metric on the configuration space. The construction of the so called quotient L2-metric is very similar to the one construction of an L2-metric on Yang-Mills moduli spaces as given by Groisser and Parker. To construct a Riemannian metric on the total space of the Seiberg-Witten bundle in a similar way, we define the reduced gauge group as a subgroup of the gauge group. We show, that the quotient of the premoduli space by the reduced gauge group is isomorphic as a U(1)-bundle to the quotient of the premoduli space by the based gauge group. The total space of this new representation of the Seiberg-Witten bundle carries a natural quotient L2-metric, and the bundle projection is a Riemannian submersion with respect to these metrics. We compute explicit formulae for the sectional curvature of the moduli space in terms of Green operators of the elliptic complex associated with a monopole. Further, we construct a Riemannian metric on the cobordism between moduli spaces for different perturbations. The second construction of a Riemannian metric on the moduli space uses a canonical global gauge fixing, which represents the total space of the Seiberg-Witten bundle as a finite dimensional submanifold of the configuration space. We consider the Seiberg-Witten moduli space on a simply connected Käuhler surface. We show that the moduli space (when nonempty) is a complex projective space, if the perturbation does not admit reducible monpoles, and that the moduli space consists of a single point otherwise. The Seiberg-Witten bundle can then be identified with the Hopf fibration. On the complex projective plane with a special Spin-C structure, our Riemannian metrics on the moduli space are Fubini-Study metrics. Correspondingly, the metrics on the total space of the Seiberg-Witten bundle are Berger metrics. We show that the diameter of the moduli space shrinks to 0 when the perturbation approaches the wall of reducible perturbations. Finally we show, that the quotient L2-metric on the Seiberg-Witten moduli space on a Kähler surface is a Kähler metric. N2 - In dieser Dissertationsschrift geben wir zwei Konstruktionen Riemannscher Metriken auf Seiberg-Witten-Modulräumen an. Beide Metriken werden in natürlicher Weise durch die L2-Metrik des Konfiguartionsraumes induziert. Die Konstruktion der sogenannten Quotienten-L2-Metrik entspricht der durch Groisser und Parker angegebenen Konstruktion einer L2-Metrik auf Yang-Mills-Modulräumen. Zur Konstruktion einer Quotienten-Metrik auf dem Totalraum des Seiberg-Witten-Bündels führen wir die sogenannte reduzierte Eichgruppe ein. Wir zeigen, dass der Quotient des Prämodulraumes nach der reduzierten Eichgruppe als U(1)-Bündel isomorph ist zu dem Quotienten nach der basierten Eichgruppe. Dadurch trägt der Totalraum des Seiberg-Witten Bündels eine natürliche Quotienten-L2-Metrik, bzgl. derer die Bündelprojektion eine Riemannsche Submersion ist. Wir berechnen explizite Formeln für die Schnittrümmung des Modulraumes in Ausdrücken der Green-Operatoren des zu einem Monopol gehörigen elliptischen Komplexes. Ferner konstruieren wir eine Riemannsche Metrik auf dem Kobordismus zwischen Modulräumen zu verschiedenen Störungen. Die zweite Konstruktion einer Riemannschen Metrik auf Seiberg-Witten-Modulräumen benutzt eine kanonische globale Eichfixierung, vermöge derer der Totalraum des Seiberg-Witten-Bündels als endlich-dimensionale Untermannigfaltigkeit des Konfigurationsraumes dargestellt werden kann. Wir betrachten speziell die Seiberg-Witten-Modulräume auf einfach zusammenhängenden Kähler-Mannigfaltigkeiten. Wir zeigen, dass der Seiberg-Witten-Modulraum (falls nicht-leer) im irreduziblen Fall ein komplex projektiver Raum its und im reduziblen Fall aus einem einzelnen Punkt besteht. Das Seiberg-Witten-Bündel läßt sich mit der Hopf-Faserung identifizieren. Die L2-Metrik des Modulraumes auf der komplex projektiven Fläche CP2 (mit einer speziellen Spin-C-Struktur) ist die Fubini-Study-Metrik; entsprechend sind die Metriken auf dem Totalraum Berger-Metriken. Wir zeigen, dass der Durchmesser des Modulraumes gegen 0 konvergiert, wenn die Störung sich dem reduziblen Fall nähert. Schließlich zeigen wir, dass die Quotienten-L2-Metrik auf dem Seiberg-Witten-Modulraum einer Kählerfläche eine Kähler-Metrik ist. KW - Eichtheorie KW - Seiberg-Witten-Invariante KW - Modulraum KW - Riemannsche Geometrie KW - Kähler-Mannigfaltigkeit KW - Unendlichdimensionale Mannigfaltigkeit KW - L2-Metrik KW - 4-Mannigfaltigkeiten KW - Gauge theory KW - Seiberg-Witten theory KW - Moduli spaces KW - Infinite dimensional manifolds KW - L2 metrics Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-5425 ER - TY - JOUR A1 - Beerenwinkel, Niko A1 - Sing, Tobias A1 - Lengauer, Thomas A1 - Rahnenfuhrer, Joerg A1 - Roomp, Kirsten A1 - Savenkov, Igor A1 - Fischer, Roman A1 - Hoffmann, Daniel A1 - Selbig, Joachim A1 - Korn, Klaus A1 - Walter, Hauke A1 - Berg, Thomas A1 - Braun, Patrick A1 - Faetkenheuer, Gerd A1 - Oette, Mark A1 - Rockstroh, Juergen A1 - Kupfer, Bernd A1 - Kaiser, Rolf A1 - Daeumer, Martin T1 - Computational methods for the design of effective therapies against drug resistant HIV strains N2 - The development of drug resistance is a major obstacle to successful treatment of HIV infection. The extraordinary replication dynamics of HIV facilitates its escape from selective pressure exerted by the human immune system and by combination drug therapy. We have developed several computational methods whose combined use can support the design of optimal antiretroviral therapies based on viral genomic data Y1 - 2005 ER - TY - JOUR A1 - Beim Graben, Peter T1 - Symbolic resonance analysis of event-related potentials distinguishes different physiological processes Y1 - 2005 SN - 0898-929X ER - TY - JOUR A1 - Beim Graben, Peter A1 - Frisch, Stefan A1 - Fink, A. A1 - Saddy, Douglas A1 - Kurths, Jürgen T1 - Topographic voltage and coherence mapping of brain potentials by means of the symbolic resonance analysis N2 - We apply the recently developed symbolic resonance analysis to electroencephalographic measurements of event- related brain potentials (ERPs) in a language processing experiment by using a three-symbol static encoding with varying thresholds for analyzing the ERP epochs, followed by a spin-flip transformation as a nonlinear filter. We compute an estimator of the signal-to-noise ratio (SNR) for the symbolic dynamics measuring the coherence of threshold-crossing events. Hence, we utilize the inherent noise of the EEG for sweeping the underlying ERP components beyond the encoding thresholds. Plotting the SNR computed within the time window of a particular ERP component (the N400) against the encoding thresholds, we find different resonance curves for the experimental conditions. The maximal differences of the SNR lead to the estimation of optimal encoding thresholds. We show that topographic brain maps of the optimal threshold voltages and of their associated coherence differences are able to dissociate the underlying physiological processes, while corresponding maps gained from the customary voltage averaging technique are unable to do so Y1 - 2005 SN - 1539-3755 ER - TY - JOUR A1 - Beissenhirtz, Moritz Karl T1 - Electrochemical quartz crystal microbalance studies on cytochrome c/polyelectrode multilayer assemblies on gold electrodes N2 - Polyelectrolyte multilayer assemblies containing proteins are of interest for applications such as sensors, bioreactors, and bioelectronics. A multilayer electrode was built up by the layer-by-layer strategy consisting of alternating layers of cytochrome c and poly(aniline sulfonic acid). The electrode showed a linear increase of redox active protein with the number of deposited layers. The principle of electrode preparation was transferred from needle electrodes to planar surfaces in order to further the understanding of electron transfer through the layer assembly by means of electrochemical quartz crystal microbalance studies. The deposition process was followed on-line by detection of the frequency shift of the crystals and was found to be rather fast (minutes). The total mass deposited was found to correlate well with the electrochemical response of the immobilized cyt.c. Furthermore, the influence of the polyelectrolyte was investigated by addition of PSS to the PASA solution. The strong interaction of the former polyelectrolyte seemed to hinder the electron transfer although a multilayer formation was proved. Dilution of the protein solution with redox inactive apo-cyt.c led to a strong decrease of the voltammetric signal, well beyond the percentage of apo-cyt.c inside the assembly. Thus, arguments for an electron transfer via protein-protein interaction were found Y1 - 2005 ER - TY - JOUR A1 - Belina, Bernd T1 - Anglophones : If you want us to understand you, you will have to speak understandably! Y1 - 2005 SN - 0066-4812 ER - TY - JOUR A1 - Belling, Detlev W. ED - Rasmussen-Bonne, Hans-Eric ED - Freer, Richard ED - Lüke, Wolfgang ED - Weitnauer, Wolfgang T1 - The church`s right of self-determination in Germany Y1 - 2005 SN - 3-8005-1437-0 ER - TY - JOUR A1 - Belykh, Vladimir N. A1 - Osipov, Grigory V. A1 - Kuckländer, Nina A1 - Blasius, Bernd A1 - Kurths, Jürgen T1 - Automatic control of phase synchronization in coupled complex oscillators N2 - We present an automatic control method for phase locking of regular and chaotic non-identical oscillations, when all subsystems interact via feedback. This method is based on the well known principle of feedback control which takes place in nature and is successfully used in engineering. In contrast to unidirectional and bidirectional coupling, the approach presented here supposes the existence of a special controller, which allows to change the parameters of the controlled systems. First we discuss general principles of automatic phase synchronization (PS) for arbitrary coupled systems with a controller whose input is given by a special quadratic form of coordinates of the individual systems and its output is a result of the application of a linear differential operator. We demonstrate the effectiveness of our approach for controlled PS on several examples: (i) two coupled regular oscillators, (ii) coupled regular and chaotic oscillators, (iii) two coupled chaotic R"ossler oscillators, (iv) two coupled foodweb models, (v) coupled chaotic R"ossler and Lorenz oscillators, (vi) ensembles of locally coupled regular oscillators, (vii) ensembles of locally coupled chaotic oscillators, and (viii) ensembles of globally coupled chaotic oscillators. Y1 - 2005 UR - http://www.agnld.uni-potsdam.de/~bernd/papers/physica_D.pdf ER - TY - JOUR A1 - Bergien, Rüdiger T1 - Reminiscent of Dennewitz : a battle and its interpretation in two centuries Y1 - 2005 SN - 0044-2828 ER - TY - JOUR A1 - Bergmann, Corinna A1 - Basta, Dietmar A1 - Ptok, Martin A1 - Ernst, Arne T1 - Quality of pronase dissociation of mature inferior colliculus neurons N2 - One major advantage of acutely dissociated inferior colliculus (IC) neurons in electrophysiological investigations is their complete isolation from the surrounding cellular network. In this way, patch-clamp recordings can be performed under controlled conditions to study membrane properties of IC neurons in more detail. The aim of the present study was to adapt a dissociation method for immature IC neurons to the highly sensitive, fragile and vulnerable mature IC neurons of mammals (mice). The modification of a pronase-based dissociation protocol with respect to concentration, incubation time and handling (trituration) of the cells yielded intact, live IC neurons with a clean cell surface so that they were well suited for further electrophysiological investigations in our study. The largely modified dissociation protocol is described in detail and critically discussed Y1 - 2005 ER - TY - JOUR A1 - Bexte, Peter T1 - Heinz von Foerster in the art department : a collide-oscope in four parts N2 - Purpose - To provide illumination of how systems tend to produce an output nobody expected. It is in these moments that observers may learn something about their own expectations. Design/methodology/approach - The paper discusses two cases in the history of art: faked Vermeer paintings and a test Heinz von Foerster did in the art department at the University of Illinois. Findings - McLuhan's notion "collide-oscope" is applied to the way Heinz von Foerster (ab)uses images in his own texts; furthermore it is applied to the way the Biological Computer Laboratory (BCL) was organized. The formal structure of the "collide-oscope" offers a model of perception. Originality/value - Provides a discussion of a fundamental message of cybernetics - that we cannot escape collisions and disturbances. They are its essence Y1 - 2005 SN - 0368-492X ER - TY - JOUR A1 - Bihler, Hermann A1 - Eing, C. A1 - Hebeisen, S. A1 - Roller, A. A1 - Czempinski, Katrin A1 - Bertl, Adam T1 - TPK1 is a vacuolar ion channel different from the slow-vacuolar cation channel N2 - TPK1 ( formerly KCO1) is the founding member of the family of two-pore domain K 1 channels in Arabidopsis ( Arabidopsis thaliana), which originally was described following expression in Sf9 insect cells as a Ca2(+)- and voltage- dependent outwardly rectifying plasma membrane K 1 channel. In plants, this channel has been shown by green fluorescent protein fusion to localize to the vacuolar membrane, which led to speculations that the TPK1 gene product would be a component of the nonselective, Ca2+ and voltage- dependent slow-vacuolar (SV) cation channel found in many plants species. Using yeast ( Saccharomyces cerevisiae) as an expression system for TPK1, we show functional expression of the channel in the vacuolar membrane. In isolated vacuoles of yeast yvc1 disruption mutants, the TPK1 gene product shows ion channel activity with some characteristics very similar to the SV-type channel. The open channel conductance of TPK1 in symmetrically 100mM KCl is slightly asymmetric with roughly 40 pS at positive membrane voltages and 75 pS at negative voltages. Similar to the SV-type channel, TPK1 is activated by cytosolic Ca2+, requiring micromolar concentration for activation. However, in contrast to the SV- type channel, TPK1 exhibits strong selectivity for K+ over Na+, and its activity turned out to be independent of the membrane voltage over the range of +/- 80mV. Our data clearly demonstrate that TPK1 is a voltage- independent, Ca2+- activated, K+- selective ion channel in the vacuolar membrane that does not mediate SV- type ionic currents Y1 - 2005 ER - TY - JOUR A1 - Binzenhöfer, Birgit A1 - Schroder, B. A1 - Strauss, B. A1 - Biedermann, Robert A1 - Settele, Josef T1 - Habitat models and habitat connectivity analysis for butterflies and burnet moths : the example of Zygaena carniolica and Coenonympha arcania N2 - In this paper, habitat models were used to predict potential habitat for endangered species, which is an important question in landscape and conservation planning. Based on logistic regression, we developed habitat distribution models for the burnet moth Zygaena carniolica and the nymphalid butterfly Coenonympha arcania in Northern Bavaria, Germany. The relation between adult occurrence and habitat parameters, including the influence of landscape context, was analyzed on, 118 sites. Habitat connectivity analyses were carried out on the basis of (1) habitat suitability maps generated from these models and (2) dispersal data from mark recapture studies. Our results showed that (1) the presence of the burnet depended mainly on the presence of nectar plants and of nutrient-poor dry grasslands in direct vicinity, that of the nymphalid on larger areas of extensively used dry grasslands within 100 m vicinity in combination with small patches of higher shrubs and bushes. (2) Internal as well as external validation indicated the robustness and general applicability of the models. Transferability in time and space indicated their high potential relevance for applications in nature conservation, such as predicting possible effects of land use changes. (3) Habitat connectivity analyses revealed a high degree of habitat connectivity within the study area. Thus, we could show no effects of isolation or habitat size for both species. (c) 2005 Elsevier Ltd. All rights reserved Y1 - 2005 ER -