TY  - THES
A1  - Zorrijassateini, Darius
ED  - Hummel, Thomas R.
ED  - Wagner, Dieter
ED  - Zander, Ernst
T1  - Organisationsentwicklung als Lernkonzept zur Nutzung von Führungsinformationssystemen
T2  - Hochschulschriften zum Personalwesen
Y1  - 2000
SN  - 3-87988-472-2
SN  - 0179-325X
VL  - 30
PB  - Hampp; ZBW
CY  - München, Mering; Kiel, Hamburg
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
T1  - Control of insP(3)-induced Ca2+ oscillations in permeabilized blowfly salivary gland cells : contribution of mitochondria
Y1  - 2000
SN  - 0022-3751
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
T1  - Subcellular organization of agonist-evoked Ca2+ waves in the blowfly salivary gland
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zillmer, Rüdiger
A1  - Ahlers, Volker
A1  - Pikovskij, Arkadij
T1  - Scaling of Lyapunov exponents of coupled chaotic systems
N2  - We develop a statistical theory of the coupling sensitivity of chaos. The effect was first described by Daido [Prog. Theor. Phys. 72, 853 (1984)]; it appears as a logarithmic singularity in the Lyapunov exponent in coupled chaotic systems at very small couplings. Using a continuous-time stochastic model for the coupled systems we derive a scaling relation for the largest Lyapunov exponent. The singularity is shown to depend on the coupling and the systems' mismatch. Generalizations to the cases of asymmetrical coupling and three interacting oscillators are considered, too. The analytical results are confirmed by numerical simulations.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zillmer, Rüdiger
A1  - Ahlers, Volker
A1  - Pikovskij, Arkadij
T1  - Stochastic approach to Lapunov exponents in coupled chaotic systems
Y1  - 2000
SN  - 3-540-41074-0
ER  - 
TY  - JOUR
A1  - Zien, Alexander
A1  - Rätsch, Gunnar
A1  - Mika, Sebastian
A1  - Schölkopf, Bernhard
A1  - Lengauer, Thomas
A1  - Müller, Klaus-Robert
T1  - Engineering support vector machine kernels that recognize translation initiation sites
Y1  - 2000
SN  - 1367-4803
ER  - 
TY  - JOUR
A1  - Ziehmann, Christine
A1  - Smith, Leonard A.
A1  - Kurths, Jürgen
T1  - Localized Lyapunov exponents and the prediction of predictability
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Ziehe, Andreas
A1  - Müller, Klaus-Robert
A1  - Nolte, G.
A1  - Mackert, B.-M.
A1  - Curio, Gabriel
T1  - Artifact reduction in magnetoneurography based on time-delayed second-order correlations
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zhuang, Y.
A1  - Schelling, Christoph
A1  - Stangl, Jochen
A1  - Penn, C.
A1  - Senz, S.
A1  - Schäffler, Friedrich
A1  - Roche, T.
A1  - Daniel, A.
A1  - Grenzer, Jörg
A1  - Pietsch, Ullrich
A1  - Bauer, Günther
T1  - Structural and optical properties of Si/Si{1-x}Ge{x} wires
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zhuang, Y.
A1  - Pietsch, Ullrich
A1  - Stangl, Jochen
A1  - Holý, Vaclav
A1  - Darowski, Nora
A1  - Grenzer, Jörg
A1  - Zerlauth, S.
A1  - Schäffler, F.
A1  - Bauer, Günther
T1  - In-plane strain and shape analysis of Si/SiGe nanostructures by grazing incidence diffraction
Y1  - 2000
ER  - 
TY  - BOOK
A1  - Zendler, Andreas
T1  - X/Frame : Softwareentwicklungsumgebung für taxonomische Objektsysteme
T3  - Preprint / Universität Potsdam, Institut für Informatik
Y1  - 2000
SN  - 0946-7580
VL  - 1999, 12
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Zeimer, Ute
A1  - Bugge, F.
A1  - Gramlich, S.
A1  - Smirnitzki, V.
A1  - Weyers, Markus
A1  - Tränkle, G.
A1  - Grenzer, Jörg
A1  - Pietsch, Ullrich
A1  - Cassabois, G.
A1  - Emiliani, V.
A1  - Lienau, C.
T1  - Evidence for strain-induced lateral carrier confinement in InGaAs quantum wells by low-temperature near-field spectroscopy
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Park, Eun Hyoung
A1  - Kurths, Jürgen
T1  - On phase synchronization by periodic force in chaotic oscillators with saddle equilibria
Y1  - 2000
ER  - 
TY  - INPR
A1  - Zakharov, Venjamin E.
A1  - Meister, Claudia-Veronika
T1  - Acceleration and heating in the auroral magnetosphere by current driven electrostatic ion cyclotron turbulence
N2  - A numerical MHD model is developed to investigate acceleration and heating of both thermal and auroral plasma. This is done for magnetospheric flux tubes in which intensive field aligned currents flow. To give each of these tubes, the empirical Tsyganenko model of the magnetospheric field is used. The parameters of the background plasma outside the flux tube as well as the strength of the electric field of magnetospheric convection are given. Performing the numerical calculations, the distributions of the plasma densities, velocities, temperatures, parallel electric field and current, and of the coefficients of thermal conductivity are obtained in a self-consistent way. It is found that EIC turbulence develops effectively in the thermal plasma. The parallel electric field develops under the action of the anomalous resistivity. This electric field accelerates both the thermal and the auroral plasma. The thermal turbulent plasma is also subjected to an intensive heating. The increase of the plasma of the Earth's ionosphere. Besides, studying the growth and dispersion properties of oblique ion cyclotron waves excited in a drifting magnetized plasma, it is shown that under non-stationary conditions such waves may reveal the properties of bursts of polarized transverse electromagnetic waves at frequencies near the patron gyrofrequency.
T3  - NLD Preprints - 59 
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14959
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Kurths, Jürgen
A1  - Schimansky-Geier, Lutz
T1  - Doubly stochastic resonance
N2  - We report the effect of doubly stochastic resonance which appears in nonlinear extended systems if the influence of noise is twofold: A multiplicative noise induces bimodality of the mean field of the coupled network and an independent additive noise governs the dynamic behavior in response to small periodic driving. For optimally selected values of the additive noise intensity stochastic resonance is observed, which is manifested by a maximal coherence between the dynamics of the mean field and the periodic input. Numerical simulations of the signal-to-noise ratio and theoretical results from an effective two state model are in good quantitative agreement.
Y1  - 2000
UR  - http://link.aps.org/abstract/PRL/v85/p227
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Kurths, Jürgen
T1  - Additive noise and noise-induced nonequilibrium phase transitions
Y1  - 2000
SN  - 1-563-96826-6
ER  - 
TY  - JOUR
A1  - Yuan, X. H
A1  - Sobolev, Stephan Vladimir
A1  - Kind, Rainer
A1  - Oncken, Onno
A1  - Bock, Günter
A1  - Asch, Günter
A1  - Schurr, B.
A1  - Gräber, F.
A1  - Rudloff, Alexander
A1  - Hanka, W.
A1  - Wylegalla, Kurt
A1  - Tibi, R.
A1  - Haberland, Christian
A1  - Rietbrock, Andreas
A1  - Giese, Peter
A1  - Wigger, Peter
A1  - Rower, P.
A1  - Zandt, G.
A1  - Beck, S.
A1  - Wallace, T.
A1  - Pardo, M.
A1  - Comte, D.
T1  - Subduction and collision processes in the Central Andes constrained by converted seismic phases
Y1  - 2000
ER  - 
TY  - BOOK
A1  - Youssef, Mona
T1  - Sozialstrukturelle und ökonomische Bestimmungsgründe der Wettbewerbsfähigkeit
N2  - Gegenstand der Untersuchung ist die Wettbewerbsfähigkeit der OECD-Länder. Inhalt: 1. Einleitung 2. Ausgangspunkt der Untersuchung  3. Die theoretische Entwicklung des Pfadmodells 3.1. Die Zielvariablen  3.2. Die Einflußfaktoren der Wettbewerbsfähigkeit  4. Die empirische Analyse  4.1. Korrelationskoeffizienten 4.2. Multiple lineare Regression  5. Schlußbemerkungen
T3  - Potsdamer Beiträge zur Sozialforschung - 9 
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10652
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Two Isoflavanones from the Stem Bark of Erythrina sacleuxii
N2  - From the stem bark of Erythrina sacleuxii two new isoflavanones, (R)-5,7-dihydroxy-2',4',5'- trimethoxyisoflavanone (trivial name, (R)-2,3-dihydro-7-demethylrobustigenin) and (R)-5-hydroxy- 2',4',5'-trimethoxy-2'',2''- dimethylpyrano[5'',6'':6,7]isoflavanone (trivial name, (R)-saclenone) were isolated. In addition the known compounds shinpterocarpin, 2,3-dehydrokievitone, abyssinone V, abyssinone V-4'-methyl ether, erythrinasinate and 4'-O-methylsigmoidin B were isolated. The structures were determined on the basis of spectroscopic evidence.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Yasuhara, Jiro
A1  - Baumann, Otto
A1  - Takeyasu, Kunio
T1  - Localization of Na/K-ATPase in developing and adult Drosophila melanogaster photoreceptors
N2  - Drosophila melanogaster photoreceptors are highly polarized cells and their plasma membrane is organized into distinct domains. Zonula adherens junctions separate a smooth peripheral surface, the equivalent of the basolateral surface in other epithelial cells, from the central surface (cong apical surface). The latter consists of the microvillar rhabdomere and the juxtarhabdomeric domain, a nonmicrovillar area between the rhabdomere and the zonulae adherens. The distribution of Na/K-ATPase over these domains was examined by immunocytochemical, developmental, and genetic approaches. Immunofluorescence and immunogold labeling of adult compound eyes reveal that the distribution of Na/ K-ATPase is concentrated at the peripheral surface in the photoreceptors R1-R6, but extends over the juxtarhabdomeric domain to the rhabdomere in the photoreceptors R7/R8. Developmental analysis demonstrates further that Na/K-ATPase is localized over the entire plasma membrane in all photoreceptors in early pupal eyes. Redistribution of Na/K-ATPase in R1- R6 occurs at about 78% of pupal life, coinciding with the onset of Rh1-rhodopsin expression on the central surface of these cells. Despite the essential role of Rh1 in structural development and intracellular trafficking, Rh1 mutations do not affect the distribution of Na/K-ATPase. These results suggest that Na/K-ATPase and rhodopsin are involved in distinct intracellular localization mechanisms, which are maintained independent of each other.
Y1  - 2000
UR  - http://www.link.springer.de/link/service/journals/00441/bibs/030002/03000239.htm
ER  - 
TY  - JOUR
A1  - Wüstneck, Rainer
A1  - Prescher, Dietrich
A1  - Katholy, Stefan
A1  - Knochenhauer, Gerald
A1  - Brehmer, Ludwig
T1  - Surface dilatational rheological study of the trans-cis isomerisation of copolymers with trifluoromethoxy substituted metacrylate monolayers
Y1  - 2000
SN  - 0927-7757
ER  - 
TY  - JOUR
A1  - Wübbeler, G.
A1  - Ziehe, Andreas
A1  - Mackert, B.-M.
A1  - Müller, Klaus-Robert
A1  - Trahms, L.
A1  - Curio, Gabriel
T1  - Independent component analysis of noninvasively recorded cortical magnetic DC-fields in humans
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wölfl, S.
A1  - Tittel, Jörg
A1  - Zippel, Barbara
A1  - Kringel, R.
T1  - Occurrence of an algal mass development in an acidic (pH 2.5), iron and aluminium-rich coal mining pond
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wächter-Springer, Lydia
T1  - Wortschatz in Veränderung : Gereimtes und Ungereimtes
N2  - Aktuelle Veränderungsprozesse in der russischen Sprache der Gegenwart (das Auftreten einer schier unübersehbaren Menge neuer Wörter, die aus anderen Sprachen ins Russische übernommen wurden, aber auch andere Formen wie z.B. die Neubildungen auf der Grundlage bereits vorhandenen russischen Wortschatzes, das Zurückfallen von bisher gebräuchlichen Wörtern in den nur noch passiven Gebrauch, die "Reanimierung" anderer Teile des Lexikbestandes, die bis vor kurzem als altmodisch und ungebräuchlich galten) werden unter didaktischen Aspekten betrachtet und demonstriert. Im Mittelpunkt stehen verschiedene Varianten des unterrichtlichen Umgangs mit solchen aktuellen sprachlichen Phänomenen - so das Ausgehen von literarischen Texten oder Empfehlungen für die Bereitstellung eines "lexikologischen Grundwissens".
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wundke, K.
A1  - Pötting, Sierk
A1  - Auxier, John A.
A1  - Schülzgen, A.
A1  - Peyghambanian, N.
A1  - Borrelli, N. F.
T1  - PbS quantum-dot-doped glasses for ultrashort-pulse generation
Y1  - 2000
ER  - 
TY  - THES
A1  - Wulf, Sabine
T1  - Das tephrochronologische Referenzprofil des Lago Grande di Monticchio : eine detallierte Stratigraphie des süditalienischen explosiven Vulkanismus der letzten 100.000 Jahre
Y1  - 2000
UR  - http://www.gfz-potsdam.de/bib/pub/str0103/0103.pdf
UR  - https://nbn-resolving.org/urn:nbn:de:kobv:b103-010113
ER  - 
TY  - JOUR
A1  - Wong, P.
A1  - Besnard, Philippe
T1  - Paraconsistent reasoning as an analytical tool
Y1  - 2000
SN  - 1367-0751
ER  - 
TY  - JOUR
A1  - Wollenberger, Ursula
T1  - Integrierte Immuno-Extraktions-Probenahme und tragbarer Biosensor-Prototyp für vor-Ort Messungen
Y1  - 2000
ER  - 
TY  - BOOK
A1  - Wolf, Birgit
T1  - Sprache in der DDR : ein Wörterbuch
N2  - Dieses Wörterbuch beschreibt die linguistischen Besonderheiten des DDR-Wortschatzes, indem es nicht nur bestimmte Sprachauffälligkeiten (Jahresendflügelfigur) oder den Sprachgebrauch der SED (Kaderschmiede) beschreibt, sondern auch vor allem den unerwünscht kritischen, meißt mündlich wiedergegebenen Alltagswortschatz (blaue Fliese, Mumienexpress) dokumentiert. Die Artikelbeschreibung ist eine Mischung von Definitionen, Kommentar, Textbeispielen, Zitaten und Witzen. Dieser Beschreibungsansatz erlaubt es, die den Wörtern innewohnenden Wertungen, Emotionen und Empfindungen angemessen darzustellen. In diesem Wörterbuch finden ostdeutsche Leser ihre Vergangenheit wieder und westdeutsche lernen, sie besser zu verstehen.
Y1  - 2000
SN  - 3-11-016427-2
PB  - de Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wolf, Beate
A1  - Klonower, Rosemarie
T1  - Regionale Material- und Energieflußrechnungen
JF  - Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-3508
SN  - 1434-2375
SN  - 1611-9339
VL  - 9
SP  - 14
EP  - 24
ER  - 
TY  - JOUR
A1  - Wischer, Ilse
T1  - Grammaticalization versus lexicalization : 'methinks' there is some confusion
Y1  - 2000
SN  - 90-272-3056-0
ER  - 
TY  - JOUR
A1  - Wipper, Renate
T1  - Interaktive multimediale Bildungssoftware "Ökosystem Wald - Artenvielfalt in Brandenburg"
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wilkens, Martin
A1  - Illuminati, Fabrizio
A1  - Krämer, Meret
T1  - Transition temperature of the weakly interacting Bose gas: perturbative solution of the crossover equations in the canonical ensemble
N2  - We compute the shift of the critical temperature Tc with respect to the ideal case for a weakly interacting uniform Bose gas. We work in the framework of the canonical ensemble, extending the criterion of condensation provided by the canonical particle counting statistics for the zero-momentum state of the uniform ideal gas. The perturbative solution of the crossover equation to lowest order in power of the scattering length yields (Tc - Tc0)/Tc0=-0,93ap 1/3, where Tc0 is the transition temperature of the corresponding ideal Bose gas , a is the scattering length, and p is the particle number density. This is at vaiance with the standard grand canonical prediction of a null shift of the critical temperature in the lowest perturbative order. The non-equevalence of statistical ensemble for the ideal Bose gas is thus confirm (at the lowestperturbative level) also in the presence of interactions.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wilczek, Michael
A1  - Wolf, Christian
A1  - Bertling, Jürgen
A1  - Kümmel, Rolf
T1  - Gewinnung von feinteiligem Brennstoff aus Abfällen
JF  - Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-3330
SN  - 1434-2375
SN  - 1611-9339
VL  - 6
SP  - 178
EP  - 190
ER  - 
TY  - JOUR
A1  - Wiesner, Sebastian
A1  - Salmikangas, Paula
A1  - Auerbach, Daniel
A1  - Himmel, Mirko
A1  - Kempa, Stefan
A1  - Hayes, Kathrin
A1  - Pacholsky, Dirk
A1  - Taivainen, Anu
A1  - Schröder, Rolf
A1  - Carpen, Olli
A1  - Fürst, Dieter Oswald
T1  - Indications for a novel muscular dystrophy pathway : gamma-filamin, the muscle-specific filamin isoform, intgeracts with myotilin
Y1  - 2000
ER  - 
TY  - THES
A1  - Wierling, Dorothee
T1  - Geboren im Jahre Eins : der Jahrgang 1949 in der DDR ; Versuch einer Kollektivbiographie ; in 3 Bänden
Y1  - 2000
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Wiegert, Ralf
T1  - Banking sector and financial intermediation in the russian transformation process
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, T.
A1  - Jeltsch, Florian
T1  - Long-term dynamics in arid and semi-arid ecosystems : synthesis of a workshop
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Ward, D.
A1  - Thulke, Hans-Hermann
A1  - Jeltsch, Florian
T1  - From snap-shot information to long-term population dynamics of Acacias by a simulation model
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Schmidt, H.
A1  - Jeltsch, Florian
A1  - Ward, D.
T1  - Linking a spatially-explicit model of acacias to GIS and remotely-sensed data
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wiegand, K.
A1  - Jeltsch, Florian
A1  - Ward, D.
T1  - Do spatial effects play a role in the spatial distribution of desert dwelling Acacias?
Y1  - 2000
ER  - 
TY  - BOOK
A1  - Wiedebach, Hartwig
ED  - Holzhey, Helmut
ED  - Schoeps, Julius H.
ED  - Schulte, Christoph
T1  - Die Hermann-Cohen-Bibliothek
T3  - Werke / Hermann Cohen : Supplementa
Y1  - 2000
SN  - 3-487-11089-X
VL  - 2
PB  - Olms
CY  - Hildesheim; Hildesheim
ER  - 
TY  - THES
A1  - Wiechula, Angela
T1  - Stadtmarketing im Kontext eines Public Management : Kundenorientierung in der kommunalen Leistungserbringung, dargestellt am Beispiel der Stadt Potsdam
T2  - Recht und Verwaltung
Y1  - 2000
SN  - 3-17-016289-6
PB  - Kohlhammer
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Staudler, Holger
A1  - Haase, Peter
A1  - Burkart, Michael
T1  - Naturschutzfachliche Bewertung einer Pflegemaßnahme mit Galloways am Südufer des Gülper See unter Einfluß hydrologischer Dynamik
N2  - Since 1993 the southern shore of Lake Gülpe in western Brandenburg has been man-aged with Galloway cattle. This is supported by the so called "Vertragsnaturschutz" (i.e. contract nature conservation) in order to preserve the valuable, species-rich vegetation structure. This is an economically justifiable arrangement for the Galloway cattle-farmer. Permanent botanical plots were monitored in the area for four years. For most species, the observed changes in vegetation are considered as mere fluctuations on the basis of their known ecological requirements and data on hydrological dynamics during the study. Only a few species might indicate succession. A continuation of the present form of land management is recommended for the preservation of the current vegetation structure. However it is advisable to continue with monitoring of the vegetation in order to confirm the results over larger timescales. Until then the management with Galloway cattle is to acclaim as a proper treatment to preserve the southern shore of Lake Gülpe.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wichmann, Matthias
A1  - Burkart, Michael
T1  - Die Vegetationszonierung des Grünlandes am Südufer des Gülper See
N2  - Since 1992 the southern shore of the Lake Gülpe in western Brandenburg is managed with Galloway cattle to preserve species, vegetation and landscape pattern. This paper presents the vegetation zones which are influenced by the water balance being the most significant and dynamic location factor in the area. Following the plots from dry to wet sites the most important plant communities are: Diantho-Armerietum, Arrhenatheretalia-Gesellschaft (-community), Leonotodon saxatilis -Potentilla anserina-community, Caricetum gracilis as well as Glycerietum aquaticae and Cypero- Samoletum. 23 endangered species were found.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Ziehmann, Christine
A1  - Kurths, Jürgen
A1  - Meyerfeldt, Udo
A1  - Schirdewan, Alexander
A1  - Voss, Andreas
T1  - Short-term forecasting of life-threatening cardiac arrhythmias based on symbolic dynamics and finite-time growth rates
N2  - Ventricular tachycardia or fibrillation (VT-VF) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this study is to find early signs of sustained VT-VF in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they store the 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 17 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e., without a VT-VF event. To characterize these rather short data sets, we calculate heart rate variability parameters from the time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that neither the time nor the frequency domain parameters show significant differences between the VT-VF and the control time series. However, two parameters from symbolic dynamics as well as the finite-time growth rates discriminate significantly both groups. These findings could be of importance in algorithms for next generation ICD's to improve the diagnostics and therapy of VT-VF.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Voss, Andreas
A1  - Malberg, Hagen
A1  - Ziehmann, Christine
A1  - Voss, Henning U.
A1  - Schirdewan, Alexander
A1  - Meyerfeldt, Udo
A1  - Kurths, Jürgen
T1  - Nonlinear analysis of complex phenomena in cardiological data
N2  - The main intention of this contribution is to discuss different nonlinear approaches to heart rate and blood pressure variability analysis for a better understanding of the cardiovascular regulation. We investigate measures of complexity which are based on symbolic dynamics, renormalised entropy and the finite time growth rates. The dual sequence method to estimate the baroreflex sensitivity and the maximal correlation method to estimate the nonlinear coupling between time series are employed for analysing bivariate data. The latter appears to be a suitable method to estimate the strength of the nonlinear coupling and the coupling direction. Heart rate and blood pressure data from clinical pilot studies and from very large clinical studies are analysed. We demonstrate that parameters from nonlinear dynamics are useful for risk stratification after myocardial infarction, for the prediction of life-threatening cardiac events even in short time series, and for modelling the relationship between heart rate and blood pressure regulation. These findings could be of importance for clinical diagnostics, in algorithms for risk stratification, and for therapeutic and preventive tools of next generation implantable cardioverter defibrillators.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Voss, Andreas
A1  - Kurths, Jürgen
A1  - Schirdewan, Alexander
A1  - Hnatkova, Katarina
A1  - Malik, Marek
T1  - Evaluation of renormalised entropy for risk stratification using heart rate variability data
N2  - Standard time and frequency parameters of heart rate variability (HRV) describe only linear and periodic behaviour, whereas more complex relationships cannot be recognised. A method that may be capable of assessing more complex properties is the non-linear measure of 'renormalised entropy.' A new concept of the method, RE(AR), has been developed, based on a non-linear renormalisation of autoregressive spectral distributions. To test the hypothesis that renormalised entropy may improve the result of high-risk stratification after myocardial infarction, it is applied to a clinical pilot study (41 subjects) and to prospective data of the St George's Hospital post- infarction database (572 patients). The study shows that the new RE(AR) method is more reproducible and more stable in time than a previously introduced method (p<0.001). Moreover, the results of the study confirm the hypothesis that on average, the survivors have negative values of RE(AR) (-0.11+/-0.18), whereas the non-survivors have positive values (0.03+/-0.22, p<0.01). Further, the study shows that the combination of an HRV triangular index and RE(AR) leads to a better prediction of sudden arrhythmic death than standard measurements of HRV. In summary, the new RE(AR) method is an independent measure in HRV analysis that may be suitable for risk stratification in patients after myocardial infarction.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Schumann, Agnes
A1  - Wessel, Niels
A1  - Schumann, Agnes
A1  - Schirdewan, Alexander
A1  - Voss, Andreas
A1  - Kurths, Jürgen
T1  - Entropy measures in heart rate variability data
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Werner, Petra
T1  - Übereinstimmung oder Gegensatz?
BT  - Zum widersprüchlichen Verhältnis zwischen A. v. Humboldt und F. W. J. Schelling
JF  - HIN : Alexander von Humboldt im Netz ; international review for Humboldtian studies
N2  - The present paper investigates the conceptual development of Alexander on Humboldt. The point of reference is his relation to Schelling and to a series of investigators of nature and of physicians closely connected to Naturphilosophie. It is shown that in the correspondence of Humboldt with this group the content underwent a transformation. Scientific exchanges and a general interpretative consensus were over the years more and more replaced by social cooperation over academic appointments, and collaboration over other political problems within the scientific establishment. Humboldt fit Schelling and other partners with whom he cooperated into a network of relationships that rested on mutual social support.
N2  - El presente estudio investiga el desarrollo conceptual de Alexander von Humboldt. El punto de referencia es la conexión con Schelling y con una serie de investigadores de ciencias naturales y físicos asociados a la filosofía de la naturaleza. Mostrará que en la correspondencia de Humboldt con este grupo el contenido cambió. Intercambios científicos y un consenso general sobre la interpretación fueron reemplazados poco a poco por una cooperación relacionada a los deberes académicos y por una colaboración a nivel de otros problemas políticos con el establishment científico. Humboldt integró a Schelling y a otros colegas con los que cooperó en una red de amistades basada en el apoyo mutuo.
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-34380
SN  - 2568-3543
SN  - 1617-5239
VL  - I
IS  - 1
SP  - 71
EP  - 109
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  -