TY - THES A1 - Schmallowsky, Antje T1 - Visualisierung dynamischer Raumphänomene in Geoinformationssystemen T1 - Visualization of dynamic spatial phenomena in geographic information systems N2 - Die visuelle Kommunikation ist eine effiziente Methode, um dynamische Phänomene zu beschreiben. Informationsobjekte präzise wahrzunehmen, einen schnellen Zugriff auf strukturierte und relevante Informationen zu ermöglichen, erfordert konsistente und nach dem formalen Minimalprinzip konzipierte Analyse- und Darstellungsmethoden. Dynamische Raumphänomene in Geoinformationssystemen können durch den Mangel an konzeptionellen Optimierungsanpassungen aufgrund ihrer statischen Systemstruktur nur bedingt die Informationen von Raum und Zeit modellieren. Die Forschung in dieser Arbeit ist daher auf drei interdisziplinäre Ansätze fokussiert. Der erste Ansatz stellt eine echtzeitnahe Datenerfassung dar, die in Geodatenbanken zeitorientiert verwaltet wird. Der zweite Ansatz betrachtet Analyse- und Simulationsmethoden, die das dynamische Verhalten analysieren und prognostizieren. Der dritte Ansatz konzipiert Visualisierungsmethoden, die insbesondere dynamische Prozesse abbilden. Die Symbolisierung der Prozesse passt sich bedarfsweise in Abhängigkeit des Prozessverlaufes und der Interaktion zwischen Datenbanken und Simulationsmodellen den verschiedenen Entwicklungsphasen an. Dynamische Aspekte können so mit Hilfe bewährter Funktionen aus der GI-Science zeitnah mit modularen Werkzeugen entwickelt und visualisiert werden. Die Analyse-, Verschneidungs- und Datenverwaltungsfunktionen sollen hierbei als Nutzungs- und Auswertungspotential alternativ zu Methoden statischer Karten dienen. Bedeutend für die zeitliche Komponente ist das Verknüpfen neuer Technologien, z. B. die Simulation und Animation, basierend auf einer strukturierten Zeitdatenbank in Verbindung mit statistischen Verfahren. Methodisch werden Modellansätze und Visualisierungstechniken entwickelt, die auf den Bereich Verkehr transferiert werden. Verkehrsdynamische Phänomene, die nicht zusammenhängend und umfassend darstellbar sind, werden modular in einer serviceorientierten Architektur separiert, um sie in verschiedenen Ebenen räumlich und zeitlich visuell zu präsentieren. Entwicklungen der Vergangenheit und Prognosen der Zukunft werden über verschiedene Berechnungsmethoden modelliert und visuell analysiert. Die Verknüpfung einer Mikrosimulation (Abbildung einzelner Fahrzeuge) mit einer netzgesteuerten Makrosimulation (Abbildung eines gesamten Straßennetzes) ermöglicht eine maßstabsunabhängige Simulation und Visualisierung des Mobilitätsverhaltens ohne zeitaufwendige Bewertungsmodellberechnungen. Zukünftig wird die visuelle Analyse raum-zeitlicher Veränderungen für planerische Entscheidungen ein effizientes Mittel sein, um Informationen übergreifend verfügbar, klar strukturiert und zweckorientiert zur Verfügung zu stellen. Der Mehrwert durch visuelle Geoanalysen, die modular in einem System integriert sind, ist das flexible Auswerten von Messdaten nach zeitlichen und räumlichen Merkmalen. N2 - Visual communication is an efficient method to describe dynamic phenomena. Perceiving information objects precisely and facilitating quick access to structured and relevant information requires consistent analysis and presentation methods conceived according to the formal minimisation principle. Because of the lack of conceptual optimisation adaptations due to their static system structure, dynamic space phenomena in geoinformation systems can only model the information of time and space conditionally. This is why research in this paper focuses on three interdisciplinary approaches. The first approach represents data collection close to real-time which is administered in geodatabases in a time-oriented manner. The second approach looks at analysis and simulation methods that analyse and forecast dynamic behaviour. The third approach conceives visualisation methods that model dynamic processes in particular. Where required, the symbolising of processes adapts to the various development phases depending on the process flow and the interaction between databases and simulation models. This allows dynamic aspects to be developed and visualised in a timely manner using modular tools with the help of proven geoscience functions. The analysis, intersection and data administration functions are intended to serve as utilisation and analysis potential as an alternative to static chart methods. For the time component, linking new technologies such as simulation and animation is significant based on a structured time database in connection with statistical methods. Modelling approaches and visualisation techniques are methodically developed and transferred to the traffic field. Dynamic traffic phenomena that cannot be modelled cohesively and comprehensively are separated into a service-oriented modular architecture in order to present them visually on different levels of space and time. Past developments and forecasts are modelled and visually analysed using various calculation methods. Linking a micro-simulation (modelling individual vehicles) to a network-controlled macro-simulation (modelling an entire road network) makes it possible to simulate and visualise mobility behaviour regardless of scale without time-consuming analysis model calculations. In the future, the visual analysis of space-time changes for planning decisions will be an efficient tool in order to make comprehensive, clearly structured and appropriate information available. The flexible analysis of measurement data according to time and space criteria represents the added value of visual geoanalysis integrated into a system with a modular structure. KW - Visualisierung KW - dynamischer Raumphänomene KW - GIS KW - Dynamik KW - Kartographie KW - Kommunikation KW - Geodaten KW - Zeit GIS KW - temporale Symbolik KW - Visualization KW - dynamic spatial phenomena KW - GIS KW - dynamics KW - cartography KW - communication KW - spatial data KW - geosience KW - temporale Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41262 ER - TY - JOUR A1 - Prengel, Annedore T1 - Vielfalt Y1 - 2009 SN - 978-3-17-019631-5 ER - TY - BOOK A1 - Bogumil, Jörg A1 - Jann, Werner ED - Benz, Arthur ED - Lütz, Susanne ED - Simonis, Georg ED - Benz, Arthur ED - Döhler, Marian ED - Lauth, Hans-Joachim T1 - Verwaltung und Verwaltungswissenschaft in Deutschland : Einführung in die Verwaltungswissenschaft T3 - Grundwissen Politik Y1 - 2009 SN - 978-3-531-16172-3 U6 - https://doi.org/10.1007/978-3-531-91341-4 VL - 36 PB - VS Verl. für Sozialwiss CY - Wiesbaden ER - TY - JOUR A1 - Sebti, Samira A1 - Saddiqi, Omar A1 - El Haimer, Fatima Zahra A1 - Michard, André A1 - Ruiz, Geoffrey A1 - Bousquet, Romain A1 - Baidder, Lahssen A1 - de Lamotte, Dominique Frizon T1 - Vertical movements at the fringe of the West African Craton : first zircon fission track datings from the Anti- Atlas Precambrian basement, Morocco N2 - The post-Variscan uplift of the western Anti-Atlas Precambrian core is studied by zircon fission track (ZFT) analysis of ten samples of granites and schists from the Kerdous and Ifni inliers. All samples yield Carboniferous ZFT ages ranging from 358 +/- 31 Ma to 319 +/- 32 Ma, with nine dates younger than 338 +/- 35 Ma. The weighted mean age calculated for these nine samples is 328 +/- 30 Ma. These results compare with the available K-Ar datings of white mica and biotite from the same rocks or from the overlying Ediacaran-Cambrian low-grade metasediments. The fact that different systems with distinct closure temperatures yield similar ages suggests the occurrence of a short Carboniferous thermal event followed by rapid cooling. Consistent with the regional geological framework, the thermal event is assigned to the Variscan folding, being followed by rapid exhumation and cooling related to the post-folding erosion. To cite this article: S. Sebti et aL, C. R. Geoscience 341 (2009). Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/16310713 U6 - https://doi.org/10.1016/j.crte.2008.11.006 SN - 1631-0713 ER - TY - JOUR A1 - Rodríguez-Quiles y García, José A. T1 - Vergleichende Musikpädagogik am Beispiel der Länder Spanien und Deutschland JF - Potsdamer Schriftenreihe zur Musikpädagogik N2 - Inhalt: 1. Musikpädagogik in Spanien: ein neues Forschungsgebiet 2. Konzeptionelle Rahmenbedingungen 3. Aktueller Stand und geplante Fortführung des Forschungsprojektes KW - Interkulturelle Musikerziehung KW - Transkulturelle Musikpädagogik KW - Kulturelle Vielfalt KW - Komparative Musikpädagogik Deutschland-Spanien KW - Intercultural Music Education KW - Trans-Cultural Music Education KW - Cultural Diversity KW - Comparative Music Education Germany-Spain Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32116 SN - 1861-8529 SN - 2196-5080 IS - 2 SP - 26 EP - 33 ER - TY - BOOK A1 - Bahro, Berno A1 - Braun, Jutta A1 - Teichler, Hans Joachim T1 - Vergessene Rekorde : jüdische Leichtathletinnen vor und nach 1933 Y1 - 2009 SN - 978-3-86650-038-9 PB - vbb Verl. für Berlin-Brandenburg CY - Berlin ER - TY - BOOK A1 - Andrae, Marianne A1 - Ebert, Johannes A1 - Garbe-von Kuczkowski, Angela A1 - Garbe, Roland A1 - Grabow, Christian A1 - Klees-Wambach, Marie-Luise A1 - Kofler, Rolf A1 - Mittmann, Michael A1 - Nickel, Michael A1 - Nöthen, Thomas A1 - Schrader-Kroschewski, Karen A1 - Schramm, Barbara A1 - Ulrich, Christoph ED - Garbe, Roland T1 - Verfahren in Familiensachen : FamFG ; ZPO ; BGB T3 - Nomos ProzessHandbuch Y1 - 2009 SN - 978-3-8329-3973-1 PB - Nomos; Beck-Online CY - Baden-Baden; München ER - TY - BOOK A1 - Höppner, Dörte A1 - Wohlrath, Christin T1 - Venture Capital als Finanzierungsalternative für Unternehmensgründungen Y1 - 2009 SN - 978-3-89936-799-7 ER - TY - JOUR A1 - Fuhr, Harald A1 - Lederer, Markus T1 - Varieties of carbon governance in newly industrializing Y1 - 2009 SN - 1070-4965 ER - TY - JOUR A1 - Salzmann, Martin T1 - Variation in resumption requires violable constraints BT - a case study in Alemannic relativization JF - Linguistics in Potsdam N2 - Variation in dative resumption among and within Alemannic varieties of German strongly favors an Evaluator component that makes use of optimality-theoretic evaluation rather than filters as in the Minimalist Program (MP). At the same time, the variation is restricted to realizational requirements. This supports a model of syntax like the Derivations and Evaluations framework (Broekhuis 2008) that combines a restrictive MP-style Generator with an Evaluator that includes ranked violable (interface) constraints. KW - resumption KW - Swiss German KW - variation KW - evaluator KW - Reference Set KW - Candidate Set KW - dative KW - constraints KW - oblique case KW - relative clauses Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32251 SN - 1616-7392 SN - 1864-1857 IS - 28 SP - 99 EP - 132 ER - TY - BOOK ED - Kügler, Frank ED - Féry, Caroline ED - van de Vijver, Ruben T1 - Variation and gradience in phonetics and phonology T3 - Phonology and Phonetics Y1 - 2009 SN - 978-3-11-021931-9 VL - 14 PB - Mouton de Gruyter CY - Berlin ER - TY - JOUR A1 - Riesch, Rüdiger A1 - Duwe, Virginia A1 - Herrmann, Nina A1 - Padur, Lisa A1 - Ramm, Annemarie A1 - Scharnweber, Inga Kristin A1 - Schulte, Matthias A1 - Schulz-Mirbach, Tanja A1 - Ziege, Madlen A1 - Plath, Martin T1 - Variation along the shy-bold continuum in extremophile fishes (Poecilia mexicana, Poecilia sulphuraria) N2 - One potential trade-off that bold individuals face is between increased predation risks and gains in resources. Individuals experiencing high predation and hungry individuals (or individuals with low body condition) are predicted to show increased boldness. We examined one behavioral trait previously reported to be associated with boldness (the time individual fish needed to emerge from shelter) in various populations of mollies (Poecilia spp.). Our study system included several southern Mexican surface streams with high piscine predation and high food availability, sulfidic surface streams with high avian predation, in which the inhabiting fish show reduced body condition, and a sulfidic cave, where predation and body condition are low. Our comparison revealed very short times to emerge from the start box in populations from non-sulfidic streams. In sulfidic habitats (whether surface or cave), it took individual Poecilia mexicana considerably longer to emerge from the start box, and the same difference was also found in an independent comparison between P. mexicana and the closely related, highly sulfide-adapted Poecilia sulphuraria. Fish reared under common garden conditions (in the absence of predators and hydrogen sulfide) showed intermediate boldness scores to the extremes observed in the field. Our data thus indicate that (a) boldness is shaped by environmental conditions/ experiential effects, but is not heritable, (b) predation affects boldness in the predicted direction, but (c) low body condition leads to reduced boldness. Extremophile Poecilia spp. spend most of their time surfacing to survive under sulfidic and hypoxic conditions, which exposes them to increased levels of predations, but the fish forage on the bottom. Hence, in this system, increased boldness does not increase foraging success. We argue that energy limitation favors reducing energetically costly behaviors, and exploring novel environments may be just one of them. Y1 - 2009 UR - http://www.springerlink.com/content/100464 U6 - https://doi.org/10.1007/s00265-009-0780-z SN - 0340-5443 ER - TY - JOUR A1 - Stein, Ruediger A1 - Hefter, Jens A1 - Gruetzner, Jens A1 - Voelker, Antje A1 - Naafs, B. David A. T1 - Variability of surface water characteristics and Heinrich-like events in the Pleistocene midlatitude North Atlantic Ocean: Biomarker and XRD records from IODP Site U1313 (MIS 16-9) N2 - A reconstruction of Milankovitch to millennial-scale variability of sea surface temperature (SST) and sea surface productivity in the Pleistocene midlatitude North Atlantic Ocean (marine isotope stage (MIS) 16-9) and its relationship to ice sheet instability was carried out on sediments from Integrated Ocean Drilling Program (IODP) Site U1313. This reconstruction is based on alkenone and n-alkane concentrations, U-37(K)' index, total organic carbon (TOC) and carbonate contents, X-ray diffraction data, magnetic susceptibility, and accumulation rates. Increased input of ice-rafted debris occurred during MIS 16, 12, and 10, characterized by high concentrations of dolomite, quartz, and feldspars and elevated accumulation rates of terrigenous matter. Minimum input values of terrigenous matter, on the other hand, were determined for MIS 13 and 11. Peak values of dolomite, coinciding with quartz, plagioclase, and kalifeldspar peaks and maxima in long-chain n-alkanes indicative for land plants, are interpreted as Heinrich-like events related to sudden instability of the Laurentide Ice Sheet during early and late (deglacial) phases of the glacials. The coincidence of increased TOC values with elevated absolute concentrations of alkenones suggests increased glacial productivity, probably due to a more southern position of the Polar Front. Alkenone-based SST reached absolute maxima of about 19 degrees C during MIS 11.3 and absolute minima of <10 degrees C during MIS 12 and 10. Within MIS 11, prominent cooling events (MIS 11.22 and 11.24) occurred. The absolute SST minima recorded directly before and after the glacial maxima MIS 10.2 and 12.2 are related to Heinrich-like event meltwater pulses, as supported by the coincidence of SST minima and maxima in C-37:4 alkenones and dolomite. These sudden meltwater pulses, especially during terminations IV and V, probably caused a collapse of phytoplankton productivity as indicated by the distinct drop in alkenone concentrations. Ice sheet disintegration and subsequent surges and outbursts of icebergs and meltwater discharge may have been triggered by increased insolation in the northern high latitudes. Y1 - 2009 UR - http://www.agu.org/journals/pa/ U6 - https://doi.org/10.1029/2008pa001639 SN - 0883-8305 ER - TY - JOUR A1 - de Libero, Loretana T1 - Vae victis! Das Schicksal der Besiegten in der römischen Antike Y1 - 2009 SN - 978-3-8062-2279-1 ER - TY - GEN A1 - Voss, Martin A1 - Blenau, Wolfgang A1 - Walz, Bernd A1 - Baumann, Otto T1 - V-ATPase deactivation in blowfly salivary glands is mediated by protein phosphatase 2C N2 - The activity of vacuolar H+-ATPase (V-ATPase) in the apical membrane of blowfly (Calliphora vicina) salivary glands is regulated by the neurohormone serotonin (5-HT). 5-HT induces, via protein kinase A, the phosphorylation of V-ATPase subunit C and the assembly of V-ATPase holoenzymes. The protein phosphatase responsible for the dephosphorylation of subunit C and V-ATPase inactivation is not as yet known. We show here that inhibitors of protein phosphatases PP1 and PP2A (tautomycin, ocadaic acid) and PP2B (cyclosporin A, FK-506) do not prevent V-ATPase deactivation and dephosphorylation of subunit C. A decrease in the intracellular Mg2+ level caused by loading secretory cells with EDTA-AM leads to the activation of proton pumping in the absence of 5-HT, prolongs the 5-HT-induced response in proton pumping, and inhibits the dephosphorylation of subunit C. Thus, the deactivation of V-ATPase is most probably mediated by a protein phosphatase that is insensitive to okadaic acid and that requires Mg2+, namely, a member of the PP2C protein family. By molecular biological techniques, we demonstrate the expression of at least two PP2C protein family members in blowfly salivary glands. © 2009 Wiley Periodicals, Inc. KW - vacuolar H+-ATPase KW - assembly KW - regulation KW - protein phosphatise KW - dephosphorylation Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44360 ER - TY - BOOK A1 - Kimminich, Eva T1 - Utopien, Jugendkulturen und Lebenswirklichkeiten : ästhetische Praxis als politisches Handeln T3 - Welt - Körper - Sprache Y1 - 2009 SN - 978-3-631-59938-9 VL - 7 PB - Lang CY - Frankfurt am Main ER - TY - JOUR A1 - Schröder, Miriam T1 - Utilizing the clean development mechanism for the deployment of renewable energies in China N2 - This article discusses how much the clean development mechanism (CDM) can contribute to the deployment of renewable energies (RE) in China. While there are at least two general barriers to utilizing CDM finance for RE deployment - namely high project costs and the proof of additionality - this article argues that an appropriate national regulation Can lead RE technologies to a stage of commercialisation at which CDM financing can become crucial. For an assessment of the current policy mix in place in China for the deployment of renewable energies, the article compares the national Chinese regulations for renewable energies and China's specific CDM rules for their impact: where do general and CDM-specific regulations for the promotion of renewable energies provide synergies, where does the policy- making on these two levels collide? Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/03062619 U6 - https://doi.org/10.1016/j.apenergy.2008.04.019 SN - 0306-2619 ER - TY - JOUR A1 - Tittel, Joerg A1 - Wiehle, Ines A1 - Wannicke, Nicola A1 - Kampe, Heike A1 - Poerschmann, Juergen A1 - Meier, Jutta A1 - Kamjunke, Norbert T1 - Utilisation of terrestrial carbon by osmotrophic algae N2 - Terrestrial-derived dissolved organic carbon (DOC) contributes significantly to the energetic basis of many aquatic food webs. Although heterotrophic bacteria are generally considered to be the sole consumers of DOC, algae and cyanobacteria of various taxonomic groups are also capable of exploiting this resource. We tested the hypothesis that algae can utilise DOC in the presence of bacteria if organic resources are supplied in intervals by photolysis of recalcitrant DOC. In short-term uptake experiments, we changed irradiation in the range of minutes. As model substrates, polymers of radiolabelled coumaric acid (PCA) were used, which during photolysis are known to release aromatic compounds comparable to terrestrial-derived and refractory DOC. Three cultured freshwater algae readily assimilated PCA photoproducts equivalent to a biomass-specific uptake of 5-60% of the bacterial competitors present. Algal substrate acquisition did not depend on whether PCA was photolysed continuously or in intervals. However, the data show that photoproducts of terrestrial DOC can be a significant resource for osmotrophic algae. In long-term growth experiments, interval light was applied one hour per day. We allowed cultured Chlamydomonas to compete for ambient DOC of low concentration. We found higher abundances of Chlamydomonas when cultures were irradiated intermittently rather than continuously. These data suggest that photolysis of DOC supports algal heterotrophy, and potentially facilitates growth, when light fluctuations are large, as during the diurnal light cycle. We concluded that osmotrophic algae can efficiently convert terrestrial carbon into the biomass of larger organisms of aquatic food webs. Y1 - 2009 UR - http://www.springerlink.com/content/101191 U6 - https://doi.org/10.1007/s00027-008-8121-2 SN - 1015-1621 ER - TY - GEN A1 - Blume, Theresa A1 - Zehe, Erwin A1 - Bronstert, Axel T1 - Use of soil moisture dynamics and patterns at different spatio-temporal scales for the investigation of subsurface flow processes N2 - Spatial patterns as well as temporal dynamics of soil moisture have a major influence on runoff generation. The investigation of these dynamics and patterns can thus yield valuable information on hydrological processes, especially in data scarce or previously ungauged catchments. The combination of spatially scarce but temporally high resolution soil moisture profiles with episodic and thus temporally scarce moisture profiles at additional locations provides information on spatial as well as temporal patterns of soil moisture at the hillslope transect scale. This approach is better suited to difficult terrain (dense forest, steep slopes) than geophysical techniques and at the same time less cost-intensive than a high resolution grid of continuously measuring sensors. Rainfall simulation experiments with dye tracers while continuously monitoring soil moisture response allows for visualization of flow processes in the unsaturated zone at these locations. Data was analyzed at different spacio-temporal scales using various graphical methods, such as space-time colour maps (for the event and plot scale) and binary indicator maps (for the long-term and hillslope scale). Annual dynamics of soil moisture and decimeterscale variability were also investigated. The proposed approach proved to be successful in the investigation of flow processes in the unsaturated zone and showed the importance of preferential flow in the Malalcahuello Catchment, a datascarce catchment in the Andes of Southern Chile. Fast response times of stream flow indicate that preferential flow observed at the plot scale might also be of importance at the hillslope or catchment scale. Flow patterns were highly variable in space but persistent in time. The most likely explanation for preferential flow in this catchment is a combination of hydrophobicity, small scale heterogeneity in rainfall due to redistribution in the canopy and strong gradients in unsaturated conductivities leading to self-reinforcing flow paths. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 125 KW - Repellent sandy soil KW - Poorly gauged catchment KW - Volcanic ash soils KW - Water repellency KW - Preferential flow Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44924 ER - TY - JOUR A1 - Gebhardt, Constance A1 - Hirschberger, Johannes A1 - Rau, Stefanie A1 - Arndt, Gisela A1 - Krainer, Karen A1 - Schweigert, Florian J. A1 - Brunnberg, Leo A1 - Kaspers, Bernd A1 - Kohn, Barbara T1 - Use of C-reactive protein to predict outcome in dogs with systemic inflammatory response syndrome or sepsis N2 - Background There is a high mortality rate in patients with systemic inflammatory response syndrome (SIRS) or sepsis. Therefore, an early diagnosis and prognostic assessment is important for optimal therapeutic intervention. The objective of the study was to evaluate if baseline values and changes in serum C-reactive protein (CRP) might predict survival in dogs with SIRS and sepsis. Design Prospective study; July 2004 to July 2005. Setting Small Animal Clinic, Berlin, Clinic of Small Animal Medicine, Munich. Animals Sixty-one dogs. Measurements and Main Results For the CRP analysis blood was drawn on day 0, 1, and 2; CRP was measured using a commercial ELISA test kit. Thirteen dogs suffered from nonseptic SIRS and 48 dogs from sepsis. The 14-day survival rate was 61% (69% nonseptic SIRS, 58% sepsis). Serum CRP was higher in sick dogs compared with controls (P < 0.001). Over the 3-day period surviving dogs (n=31) displayed a significantly greater decrease in CRP than nonsurvivors (n=10) (P=0.001). No correlation was found between the initial CRP concentrations and the survival rate. The changes in CRP corresponded to the survival rate (P=0.01). Conclusion There was no significant relationship between the survival rate in dogs with nonseptic SIRS or sepsis and the initial serum CRP concentrations. There was a correlation between decreasing CRP concentrations and recovery from disease. However, the changes in CRP concentrations over a 3-day period correctly predicted survival in 94% of dogs and death in 30% of the dogs (false positive rate 22%). Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=1479-3261 U6 - https://doi.org/10.1111/j.1476-4431.2009.00462.x SN - 1479-3261 ER - TY - JOUR A1 - de Libero, Loretana T1 - Usbekistan in der Antike Y1 - 2009 ER - TY - JOUR A1 - Nagl, Britta A1 - Loui, Andrea A1 - Raila, Jens A1 - Felderhoff-Mueser, Ursula A1 - Obladen, Michael A1 - Schweigert, Florian J. T1 - Urinary vitamin A excretion in very low birth weight infants N2 - Vitamin A (VA) deficiency in very low birth weight (VLBW) infants is associated with an increased risk for disorders related to kidney and lung maturation and function. VA losses through increased urinary retinol (ROH) excretion might contribute to this deficiency risk. The mechanism accounting for ROH loss in the urine has not yet been clarified. The aim of this study was to assess the excretion of ROH, retinol-binding protein 4 (RBP4) and transthyretin (TTR) in urine from VLBW infants in comparison with that in term infants in relation to kidney function. Urine specimens were collected from 15 VLBW infants (birth weight < 1,500 g) as well as from 20 term infants during the first 2 days after birth. ROH in urine was detectable in 14 of the 15 VLBW infants at a median concentration of 234 nmol/g creatinine. In the group of term infants, 17 of the 20 excreted ROH, but at an approximately five-times lower concentration (P<0.001). Excretion of RBP4 and TTR was also much higher in VLBW infants (both P<0.001). The urinary ROH excretion in VLBW infants may be related to the impaired tubular handling of its carrier proteins RBP4 and TTR. Thus, ROH excretion might contribute to an increased risk of VA deficiency, especially in VLBW infants. Y1 - 2009 UR - http://www.springerlink.com/content/100382 U6 - https://doi.org/10.1007/s00467-008-0965-0 SN - 0931-041X ER - TY - THES A1 - Ulrich, Jan Nicolaus T1 - Urherrecht und Satellitenrundfunk : Kollisionsrecht und materielles Recht Y1 - 2009 SN - 978-3-8305-1693-4 PB - BWV CY - Berlin ER - TY - JOUR A1 - Oberauer, Klaus A1 - Vockenberg, Kerstin T1 - Updating of working memory : lingering bindings N2 - Three experiments investigated proactive interference and proactive facilitation in a memory-updating paradigm. Participants remembered several letters or spatial patterns, distinguished by their spatial positions, and updated them by new stimuli up to 20 times per trial. Self-paced updating times were shorter when an item previously remembered and then replaced reappeared in the same location than when it reappeared in a different location. This effect demonstrates residual memory for no-longer-relevant bindings of items to locations. The effect increased with the number of items to be remembered. With one exception, updating times did not increase, and recall of final values did not decrease, over successive updating steps, thus providing little evidence for proactive interference building up cumulatively. Y1 - 2009 UR - http://www.informaworld.com/openurl?genre=journal&issn=1747-0218 U6 - https://doi.org/10.1080/17470210802372912 SN - 1747-0218 ER - TY - BOOK A1 - Brechenmacher, Thomas T1 - Unveröffentliche Dokumente aus dem Nachlaß des Ministerialdirektors Rudolf Buttmann zur Geschichte des Reichskonkordates (1933-1935) Y1 - 2009 SN - 978-3-506-76465-2 ER - TY - THES A1 - Apel, Wiebke T1 - Untersuchung und Veränderung der Genexpression und Proteinstabilität in Plastiden höherer Pflanzen Y1 - 2009 CY - Potsdam ER - TY - THES A1 - Schmidt, Antje T1 - Untersuchung des Recyclings Kaede-fusionierter Corticotropin-Releasing-Factor Rezeptoren Typ 1 T1 - Use of Kaede-Fusions to Visualize Recycling of the Corticotropin-Releasing Factor Receptor Type 1 N2 - Aktivierte G-Protein-gekoppelte Rezeptoren (GPCR) werden schnell desensitisiert, internalisiert und anschließend entweder lysosomal degradiert oder zur Plasmamembran (PM) recycelt. Zur Resensitisierung der Zellen tragen neben recycelten auch neusynthetisierte Rezeptoren bei. Die Überlagerung beider Prozesse erschwert die Untersuchung des Rezeptorrecyclings. In dieser Arbeit sollte mit Hilfe des photokonvertierbaren Fluoreszenzproteins Kaede eine Technik entwickelt werden, mit der es möglich ist Recycling- von Neusyntheseprozessen zu trennen und das Recycling von GPCR mikroskopisch in Echtzeit zu beobachten. Als Modellproteine wurden der Vasopressin-1a-Rezeptor V1aR (recycelnder Rezeptor), der Vasopressin-2-Rezeptor V2R (degradierter Rezeptor) und der Corticotropin-Releasing Factor-Rezeptor Typ 1 (CRF1R) verwendet, wobei bei Letzterem untersucht werden sollte, ob er nach Stimulation zur PM zurücktransportiert wird. Da Kaede als fluoreszierendes Protein mit den GPCR fusioniert wird, wurde zunächst überprüft, ob es die Eigenschaften der Rezeptoren verändert und generell für Transportstudien geeignet ist. Eventuell könnte die bereits publizierte Tetramerisierung von Kaede seine Anwendung verhindern oder erschweren. Mittels Fluoreszenz-Korrelationsspektroskopie konnte gezeigt werden, dass Kaede nicht tetramerisiert, wenn es an ein Membranprotein fusioniert ist. Außerdem konnte in in vitro- und Zellkulturexperimenten belegt werden, dass die native und die photokonvertierte Form von Kaede gleichermaßen stabil sind. Darüber hinaus zeigten Kaede-fusionierte GPCR sowohl in Kolokalisationsstudien als auch in Agonistbindungs- und Rezeptoraktivierungsexperimenten die gleichen Eigenschaften wie CFP- bzw. die unfusionierte Rezeptoren. Lediglich die Expression der Kaede-fusionierten Rezeptoren war geringer. Parallel wurde anhand der bereits publizierten Kaede-Struktur versucht, die Tetramerisierung des Proteins durch den Austausch interagierender Aminosäuren zu unterbinden. Die eingeführten Mutationen bewirkten aber eine Fehlfaltung des Proteins und damit den Verlust der Fluoreszenz. Da zuvor gezeigt werden konnte, dass Kaede-fusionierte Membranproteine nicht tetramerisieren und nicht die Eigenschaften der fusionierten Proteine verändern, war monomerisiertes Kaede zur Untersuchung des Rezeptorrecyclings nicht notwendig. Im zweiten Teil der Arbeit wurde mit Hilfe von Kaede-Fusionsproteinen und mikroskopischer Testsysteme das noch unbekannte Recyclingverhalten des CRF1R untersucht. Hierfür wurden die Kaede-fusionierten Rezeptoren in eukaryotischen Zellen exprimiert und mit Agonisten internalisiert. Die internalisierten Rezeptoren wurden in Endosomen selektiv mit UV-Strahlung photokonvertiert. Anschließend wurde der Transport der photokonvertierten Form verfolgt. Sowohl beim CRF1R als auch beim V1aR wurden Signale in der PM detektiert, beim V2R hingegen nicht. Dies zeigt, dass es sich beim CRF1R um einen recycelnden Rezeptor handelt. Die als Kontrolle eingesetzten Rezeptoren verhielten sich in diesem Experiment wie erwartet: Der V1aR wurde zur PM zurücktransportiert, der V2R nicht. Diese Ergebnisse konnten mit Hilfe biochemischer und durchflusscytometrischer Experimente bestätigt werden. Die Internalisierung des CRF1R verläuft Clathrin-vermittelt in Anwesenheit von β-Arrestin. Je nach Stabilität der β Arrestin-Interaktion unterscheidet man zwei Klassen von Rezeptoren: Klasse A-Rezeptoren interagieren transient mit β Arrestin und können recyceln. Im Gegensatz dazu gehen Klasse B-Rezeptoren eine stabile Interaktion mit β Arrestin ein und werden nach Internalisierung degradiert. In mikroskopischen Untersuchungen konnte für die aktivierten CRF1R und V1aR eine Rekrutierung von β Arrestin zur PM und eine transiente Interaktion mit β Arrestin gezeigt werden (Klasse A-Rezeptoren). Für den V2R wurde dagegen eine stabile Interaktion mit β Arrestin beobachtet (Klasse B-Rezeptor). Diese Daten stützen die Ergebnisse des Kaede-basierten Recyclingversuchs und zeigen, dass der CRF1R ein recycelnder Rezeptor ist. Ferner wurde untersucht, ob der CRF1R zu den schnell oder langsam recycelnden Rezeptoren zählt. Schnell recycelnde Rezeptoren werden direkt aus frühen Endosomen, langsam recycelnde hingegen über das Trans-Golgi-Netzwerk (TGN) bzw. über Recycling-Endosomen zur PM transportiert. Als Marker für das TGN oder die Recycling-Endosomen wurde Rab11 verwendet. In Kolokalisationsstudien konnte gezeigt werden, dass der CRF1R den langsam recycelnden Rezeptoren zugeordnet werden kann. Zusammenfassend konnte in dieser Arbeit belegt werden, dass Kaede als Fusionspartner für Membranproteine genutzt werden kann um deren Transport in Echtzeit zu studieren. Damit wurde erstmals eine mikroskopische Methode etabliert, die es erlaubt recycelnde von neusynthetisierten Rezeptoren zu unterscheiden. Mit Hilfe dieser Methode war es möglich zu zeigen, dass der CRF1R ein recycelnder Rezeptor ist. N2 - Upon ligand binding and receptor activation, G protein-coupled receptors (GPCR) are rapidly desensitized, internalized and subsequently degraded in lysosomes or recycled back to the plasma membrane. Resensitization of the cell is enabled by both recycling receptors and newly synthesized receptors. The overlap of recycling and synthesis processes largely complicates the study of GPCR recycling mechanisms. One aim of this thesis was to develop a new microscopic technique for real-time visualization of GPCR recycling using the photoconvertible Kaede protein allowing to differentiate newly synthesized from recycling receptors. As model proteins, the V1aR (recycling receptor), the V2R (degraded receptor) and the CRF1R were used. In the case of the CRF1R, it was unknown whether this receptor recycles to the plasma membrane following agonist-promoted internalization. The study of the CRF1R recycling behaviour was another objective of this work. As the Kaede protein is fused C-terminally to the GPCRs, an influence on the pharmacological and trafficking properties of the receptors must be excluded. The previously published tetramerization of Kaede, for example, might hinder or even prevent its usability. To assess for the applicability of Kaede, fluorescence correlation spectroscopy experiments were performed and it was demonstrated that Kaede fused to membrane proteins cannot form tetramers in contrast to the soluble form. In vitro studies and experiments in cell culture revealed that both the native and the photoconverted Kaede are equally stable. Moreover Kaede-fused GPCR displayed the same pharmacological and trafficking properties as the untagged or CFP-tagged receptors. Only the expression levels of the Kaede fusion proteins were reduced, yet this did not affect the microscopic experiments. In parallel to these experiments, the interacting amino acids of the tetrameric Kaede were substituted according to the previously published crystal structure of the protein. Unfortunately, these mutations induced protein misfolding thereby causing loss of fluorescence functions. However, since it could be shown that membrane protein-fused Kaede cannot tetramerize, the monomerized Kaede was no more essential for the microscopic study of receptor recycling. In the second part of this work, Kaede-fusions were used to study the recycling behaviour of the CRF1R and the V1aR and V2R control proteins by the novel real-time recycling assay at the laser scanning microscope. To this end, HEK 293 cells expressing the Kaede-fused receptors were treated with agonist to induce receptor internalization. Internalized receptors were selectively photoconverted in endosomes using UV-irradiation and the subcellular fate of the new fluorescence signals was studied. In the case of the CRF1R, signals of the photoconverted receptors could be detected in the plasma membrane indicating that the CRF1R belongs to the family of recycling receptors. The control receptors showed the expected results: The V1aR recycled back to the plasma membrane whereas the V2R did not. These results were confirmed with biochemical and flow cytometry measurements. The CRF1R internalizes in a clathrin-dependent way via the adaptor protein AP2, dynamin and β arrestin. Depending on the stability of the resulting receptor-β-arrestin-complex, two classes of receptors can be differentiated. Class A receptors are recycling receptors undergoing a more transient β-arrestin interaction. In contrast, class B receptors stably interact with β-arrestin and are degraded after internalization. In the case of the CRF1R and V1aR, microscopic analyzes demonstrated that β arrestin transiently interacts with the stimulated CRF1R and V1aR indicating again that these receptors are recycling GPCRs (class A receptors). The V2R, in contrast, revealed a stable interaction (class B receptor). Moreover, it was studied whether the CRF1R recycles rapidly or more slowly to the plasma membrane. Rapidly recycling receptors are recruited out of early endosomes whereas slowly recycling receptors pass the trans-golgi-network or recycling endosomes before reaching the cell surface. Rab11 colocalization studies demonstrated that the CRF1R belongs to the family of slowly recycling receptors. In conclusion, a novel microscopic technique was established allowing to study GPCR recycling in real-time and to differentiate recycling and synthesis processes. Moreover, it was shown that the CRF1R belongs to the family of recycling receptors. The Kaede technique seems to be very well suited to study membrane protein trafficking in general. KW - Corticotropin-Releasing Factor Rezeptor Typ 1 KW - Recycling KW - GPCR KW - Kaede KW - Corticotropin-Releasing Factor Receptor Type 1 KW - Recycling KW - GPCR KW - Kaede Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-34902 ER - TY - JOUR A1 - Koubek, Jochen T1 - Unterstützung der Lehre mit partizipativen Medien JF - Commentarii informaticae didacticae : (CID) N2 - Es gibt eine Vielzahl an partizipativen Medien, die zur Unterstützung von Lehrveranstaltungen eingesetzt werden können. Im Beitrag wird ein Kategorienschema vorgestellt, auf ausgewählte Fallbeispiele angewendet und mit Blick auf den didaktischen Einsatz ausgewertet. KW - Informatik KW - Ausbildung KW - Didaktik KW - Hochschuldidaktik Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29628 SN - 1868-0844 SN - 2191-1940 IS - 1 SP - 25 EP - 38 ER - TY - THES A1 - Dittmer, Mareike T1 - Unterricht, E-Mail und Internet in Kombination für das Lernen im Chemieunterricht Y1 - 2009 CY - Potsdam ER - TY - THES A1 - Hartmann, Alexander T1 - Unterlassungsansprüche im Internet : Störerhaftung für nutzgenerierte Inhalte T2 - Information und Recht Y1 - 2009 SN - 978-3-406-59658-2 VL - 75 PB - Beck CY - München ER - TY - JOUR A1 - Koehler, Andreas A1 - Ohrnberger, Matthias A1 - Scherbaum, Frank T1 - Unsupervised feature selection and general pattern discovery using Self-Organizing Maps for gaining insights into the nature of seismic wavefields N2 - This study presents an unsupervised feature selection and learning approach for the discovery and intuitive imaging of significant temporal patterns in seismic single-station or network recordings. For this purpose, the data are parametrized by real-valued feature vectors for short time windows using standard analysis tools for seismic data, such as frequency-wavenumber, polarization, and spectral analysis. We use Self-Organizing Maps (SOMs) for a data-driven feature selection, visualization and clustering procedure, which is in particular suitable for high-dimensional data sets. Our feature selection method is based on significance testing using the Wald-Wolfowitz runs test for-individual features and on correlation hunting with SOMs in feature subsets. Using synthetics composed of Rayleigh and Love waves and real-world data, we show the robustness and the improved discriminative power of that approach compared to feature subsets manually selected from individual wavefield parametrization methods. Furthermore, the capability of the clustering and visualization techniques to investigate the discrimination of wave phases is shown by means of synthetic waveforms and regional earthquake recordings. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00983004 U6 - https://doi.org/10.1016/j.cageo.2009.02.004 SN - 0098-3004 ER - TY - JOUR A1 - Uba, Cornelius Eji A1 - Kley, Jonas A1 - Strecker, Manfred A1 - Schmitt, Axel K. T1 - Unsteady evolution of the Bolivian Subandean thrust belt : the role of enhanced erosion and clastic wedge progradation N2 - The Subandean fold and thrust belt of Bolivia constitutes the easternmost part of the Andean orogen that reflects thin-skinned shortening and eastward propagation of the Andean deformation front. The exact interplay of tectonics, climate, and erosion in the deposition of up to 7.5 km of late Cenozoic strata exposed in the Subandes remains unclear. To better constrain these relationships, we use four W-E industry seismic reflection profiles, eight new zircon U-Pb ages from Mio-Pliocene sedimentary strata, and cross-section balancing to evaluate the rates of thrust propagation, shortening, and deposition pinch-out migration. Eastward thrusting arrived in the Subandean belt at similar to 12.4 +/- 0.5 Ma and propagated rapidly toward the foreland unit approximately 6 Ma. This was followed by out-of- sequence deformation from ca. 4 to 2.1 Ma and by renewed eastward propagation thereafter. Our results show that the thrust-front propagation- and deposition pinch-out migration rates mimic the sediment accumulation rate. The rates of deposition pinchout migration and thrust propagation increased three- and two fold, respectively (8 mm/a; 3.3 mm/a) at 86 Ma. The three-fold increase in deposition pinch-out migration rate at this time is an indication of enhanced erosional efficiency in the hinterland, probably coupled with flexural rebound of the basin. Following the pulse of pinch-out migration, the Subandean belt witnessed rapid similar to 80 km eastward propagation of thrusting to the La Vertiente structure at 6 Ma. As there is no evidence for this event of thrust front migration being linked to an increase in shortening rate, the enhanced frontal accretion suggests a shift to supercritical wedge taper conditions. We propose that the supercritical state was due to a drop in basal strength, caused by sediment loading and pore fluid overpressure. This scenario implies that climate-controlled variation in erosional efficiency was the driver of late Miocene mass redistribution, which induced flexural rebound of the Subandean thrust belt, spreading of a large clastic wedge across the basin, and subsequent thrust-front propagation. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/0012821X U6 - https://doi.org/10.1016/j.epsl.2009.02.010 SN - 0012-821X ER - TY - JOUR A1 - de Frenne, Pieter A1 - Kolb, Annette A1 - Verheyen, Kris A1 - Brunet, Johanne A1 - Chabrerie, Olivier A1 - Decocq, Guillaume A1 - Diekmann, Martin A1 - Eriksson, Ove A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Jõgar, Ülle A1 - Stanton, Sara A1 - Quataert, Paul A1 - Zindel, Renate A1 - Zobel, Martin A1 - Graae, Bente Jessen T1 - Unravelling the effects of temperature, latitude and local environment on the reproduction of forest herbs N2 - Aim To investigate the effect of temperature, latitude and local environment on the reproductive traits of widespread perennial forest herbs to better understand the potential impacts of rising temperatures on their population dynamics and colonization capacities. Location Six regions along a latitudinal gradient from France to Sweden. Methods Within each region, we collected data from three to five populations of up to six species. For each species, several variables were recorded in each region (temperature, latitude) and population (local abiotic and biotic environmental variables), and seed production and germination were estimated. Resource investment in reproduction (RIR) was quantified as seed number ¥ seed mass, while germinable seed output (GSO) was expressed as seed number ¥ germination percentage.We performed linear regression and mixed effect models to investigate the effects of temperature (growing degree hours), latitude and local abiotic and biotic environment on RIR and GSO. Results Temperature and latitude explained most of the variation in RIR and GSO for early flowering species with a northerly distribution range edge (Anemone nemorosa, Paris quadrifolia and Oxalis acetosella). Reproduction of the more southerly distributed species (Brachypodium sylvaticum, Circaea lutetiana and Primula elatior), in contrast, was independent of temperature/latitude. In the late summer species, B. sylvaticum and C. lutetiana, variation in RIR and GSO was best explained by local environmental variables, while none of the investigated variables appeared to be related to reproduction in P. elatior. Main conclusions We showed that reproduction of only two early flowering, northerly distributed species was related to temperature. This suggests that the potential reproductive response of forest herbs to climate warming partly depends on their phenology and distribution, but also that the response is to some extent species dependent. These findings should be taken into account when predictions about future shifts in distribution range are made. Y1 - 2009 UR - http://www3.interscience.wiley.com/journal/118545893/home U6 - https://doi.org/10.1111/j.1466-8238.2009.00487.x SN - 1466-822X ER - TY - JOUR A1 - Shkilnyy, Andriy A1 - Gräf, Ralph A1 - Hiebl, Bernhard A1 - Neffe, Axel T. A1 - Friedrich, Alwin A1 - Hartmann, Juergen A1 - Taubert, Andreas T1 - Unprecedented, low cytotoxicity of spongelike calcium phosphate/poly(ethylene imine) hydrogel composites N2 - Covalently crosslinked PEI hydrogels are efficient templates for calcium phosphate mineralization in SBF. In contrast to the PEI hydrogels, non-crosslinked PEI does not lead to calcium phosphate nucleation and growth in SBF. The precipitate is a mixture of brushite and hydroxyapatite. The PEI/calcium phosphate composite material exhibits a sponge like morphology and a chemical composition that is interesting for implants. Cytotoxicity tests using Dictyostelium discoideum amoebae show that both the non-mineralized and mineralized hydrogels have a very low cytotoxicity. This suggests that next generation PEI hydrogels, where also the degradation products are non-toxic, could be interesting for biomedical applications. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/77002860 U6 - https://doi.org/10.1002/mabi.200800266 SN - 1616-5187 ER - TY - JOUR A1 - Weiss, Norman T1 - Universelle Menschenrechte in einer fragmentierten Welt Y1 - 2009 SN - 978-3- 7917-2214-6 ER - TY - THES A1 - Butkote, Runglawan T1 - Universal-algebraic and Semigroup-theoretical Properties of Boolean Operations Y1 - 2009 CY - Potsdam ER - TY - BOOK A1 - Denecke, Klaus-Dieter A1 - Wismath, Shelly L. T1 - Universal Algebra and Coalgebra Y1 - 2009 SN - 978-981-283745-5 PB - World Scientific Publ. Co CY - Singapore ER - TY - JOUR A1 - Gerth, Sabrina A1 - Beim Graben, Peter T1 - Unifying syntactic theory and sentence processing difficulty through a connectionist minimalist parser N2 - Syntactic theory provides a rich array of representational assumptions about linguistic knowledge and processes. Such detailed and independently motivated constraints on grammatical knowledge ought to play a role in sentence comprehension. However most grammar-based explanations of processing difficulty in the literature have attempted to use grammatical representations and processes per se to explain processing difficulty. They did not take into account that the description of higher cognition in mind and brain encompasses two levels: on the one hand, at the macrolevel, symbolic computation is performed, and on the other hand, at the microlevel, computation is achieved through processes within a dynamical system. One critical question is therefore how linguistic theory and dynamical systems can be unified to provide an explanation for processing effects. Here, we present such a unification for a particular account to syntactic theory: namely a parser for Stabler's Minimalist Grammars, in the framework of Smolensky's Integrated Connectionist/Symbolic architectures. In simulations we demonstrate that the connectionist minimalist parser produces predictions which mirror global empirical findings from psycholinguistic research. Y1 - 2009 UR - http://www.springerlink.com/content/1871-4099 U6 - https://doi.org/10.1007/s11571-009-9093-1 SN - 1871-4080 ER - TY - BOOK A1 - Späth, Daniela T1 - Uni goes Facebook : Evaluatonsstudie zur Förderung von Kooperativen Lernprozessen mithilfe des Tools virtPresenter : eLearning UP 2009 : Sonderveranstaltung 2009-11-25 Y1 - 2009 UR - http://info.ub.uni-potsdam.de/multimedia/show_projekt.php?projekt_id=55 PB - Univ.-Bibl. CY - Potsdam ER - TY - JOUR A1 - Ianoş, Ioan A1 - Cepoiu, Andreea-Loreta A1 - Pintilii, Radu-Daniel T1 - Ungleichmäßige intraregionale Entwicklung der Nordost-Region Rumäniens JF - Potsdamer geographische Forschungen Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-38834 SN - 0940-9688 IS - 28 SP - 103 EP - 121 ER - TY - JOUR A1 - Mochan, Christiane T1 - Ungesetzlicher Gewaltgebrauch durch die Polizei JF - Beiträge zu einer vergleichenden Soziologie der Polizei N2 - Inhalt: Probleme bei der Erforschung des Themas - Forschungsstand in Deutschland Definition der ungesetzlichen Gewaltanwendung durch die Polizei Kennzeichen übermäßiger Gewaltanwendung durch PolizistInnen Individuelle Erklärungsansätze - Arbeitsbelastungen und Situation - Authority Maintenance Theory nach Alpert und Dunham Die Organisation von Polizei als Erklärungsansatz - Cop Culture Mögliche Auswege Resümee KW - Polizei KW - Polizeisoziologie KW - Police KW - Sociology Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29409 SP - 18 EP - 32 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Pingel, Patrick A1 - Zen, Achmad A1 - Neher, Dieter A1 - Lieberwirth, Ingo A1 - Wegner, Gerhard A1 - Allard, Sybille A1 - Scherf, Ullrich T1 - Unexpectedly high field-effect mobility of a soluble, low molecular weight oligoquaterthiophene fraction with low polydispersity N2 - Layers made from soluble low molecular weight polythiophene PQT-12 with low polydispersity exhibit a highly ordered structure and charge-carrier mobilities of the order of 10(-3) cm(2)/(V s), which we attribute to its proximity to monodispersity. We propose that polydispersity is a decisive factor with regard to structure formation and transport properties of soluble low molecular weight polythiophenes. Y1 - 2009 UR - http://www.springerlink.com/content/100501 U6 - https://doi.org/10.1007/s00339-008-4994-0 SN - 0947-8396 ER - TY - JOUR A1 - Laggner, Benno T1 - UN-Politik der Schweiz: Handlungsmöglichkeiten eines Staates mittlerer Größe JF - Die Vereinten Nationen in den internationalen Beziehungen , 9. Potsdamer UNO-Konferenz am 28. Juni 2008 N2 - 1. Vorbemerkung 2. Geopolitische Rahmenbedingungen der aktuellen UN-Politik 3. Engagement der Schweiz in der UNO 4. Zwei konkrete Beispiele für schweizerische Initiativen im UN-Rahmen 5. Schlussbemerkung Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-101625 VL - 2009 IS - 8 SP - 15 EP - 22 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - RPRT T1 - Umweltdaten Brandenburg [2008/09] KW - Brandenburg KW - Umweltschutz KW - Klimaschutz KW - Strahlenschutz KW - Luftqualität Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-bbdig-238 VL - 2008/09 ER - TY - JOUR A1 - Hanke, Christine T1 - Umstrittenes Terrain : Perspektiven der Wissenschafts- und Technikforschung Y1 - 2009 ER - TY - JOUR A1 - Esser, Günter T1 - Umschriebene Entwicklungsstörungen Y1 - 2009 SN - 9788-3-642-01476-5 ER - TY - THES A1 - Radziuk, Darya V. T1 - Ultrasonic activation of nanocatalysts and formation of binary nanoparticles Y1 - 2009 CY - Potsdam ER - TY - JOUR A1 - Woerner, Michael A1 - von Korff Schmising, Clemens A1 - Bargheer, Matias A1 - Zhavoronkov, Nickolai A1 - Vrejoiu, Ionela A1 - Hesse, Dietrich A1 - Alexe, Marin A1 - Elsaesser, Thomas T1 - Ultrafast structural dynamics of perovskite superlattices N2 - Femtosecond x-ray diffraction provides direct insight into the ultrafast reversible lattice dynamics of materials with a perovskite structure. Superlattice (SL) structures consisting of a sequence of nanometer-thick layer pairs allow for optically inducing a tailored stress profile that drives the lattice motions and for limiting the influence of strain propagation on the observed dynamics. We demonstrate this concept in a series of diffraction experiments with femtosecond time resolution, giving detailed information on the ultrafast lattice dynamics of ferroelectric and ferromagnetic superlattices. Anharmonically coupled lattice motions in a SrRuO3/PbZr0.2Ti0.8O3 (SRO/ PZT) SL lead to a switch-off of the electric polarizations on a time scale of the order of 1 ps. Ultrafast magnetostriction of photoexcited SRO layers is demonstrated in a SRO/SrTiO3 (STO) SL. Y1 - 2009 UR - http://www.springerlink.com/content/100501 U6 - https://doi.org/10.1007/s00339-009-5174-6 SN - 0947-8396 ER - TY - JOUR A1 - Klamroth, Tillmann A1 - Nest, Mathias T1 - Ultrafast electronic excitations of small sodium clusters and the onset of electron thermalization N2 - In this paper we report simulations of the ultrafast laser excitation and relaxation of the correlated valence electrons of a Na-8 cluster. The aim is twofold: first, while the total energy stays constant when the exciting laser pulse is over, we observe that the entropy computed from the reduced one electron density matrix rises on a much longer time scale. We discuss whether this can be understood as the onset of the thermalization of a finite system. Second, we describe this process with eight different methods of wavefunction-based electronic structure theory, which have been adapted for an explicitly time-dependent description. Their respective advantages and limitations for the simulation of the excitation and subsequent relaxation are explained. Y1 - 2009 UR - http://pubs.rsc.org/en/Journals/JournalIssues/CP U6 - https://doi.org/10.1039/B813619j SN - 1463-9076 ER - TY - JOUR A1 - Denz, Rebekka T1 - Ulrich Knufinke: Bauwerke jüdischer Friedhöfe in Deutschland / [rezensiert von] Rebekka Denz JF - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien e.V. N2 - rezensiertes Werk: Knufinke, Ulrich: Bauwerke jüdischer Friedhöfe in Deutschland. - Petersberg : Imhof Verlag, 2007. - 456 S. (Schriftenreihe der Bet Tfila-Forschungsstelle für jüdische Architektur in Europa ; 3) ISBN 978-3-86568-206-2 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-38091 SN - 1614-6492 SN - 1862-7684 IS - 15 SP - 167 EP - 170 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Goelzer, Heiko A1 - Levermann, Anders A1 - Rahmstorf, Stefan T1 - Two-way coupling of an ENSO model to the global climate model CLIMBER-3 alpha N2 - We present a model study that investigates to what extent it is possible to introduce ENSO variability to an Earth system Model of Intermediate Complexity (EMIC). The Zebiak-Cane ENSO model is dynamically coupled to the EMIC CLIMBER-3 alpha, which by itself exhibits no interannual or multidecadal variability. ENSO variability is introduced to CLIMBER-3 alpha by adding ENSO-related sea surface temperature anomalies to the upper layers of the model ocean. For the other coupling direction, changes in the mean CLIMBER-3 alpha climate on decadal time scales are used to change the background state of the ENSO model, achieving a two-way coupling. We compare typical ENSO-related patterns of a fully coupled pre-industrial model run to reanalysis data and point out the possibilities and limitations of this model configuration. Although introduced ENSO-related SST anomalies and other related variables like the Southern Oscillation Index are well reproduced by the EMIC in the forcing domain, teleconnections to other regions are damped, especially in meridional direction. The reason for this limitation is the atmospheric model, which does not sufficiently resolve the necessary transport mechanisms. Despite this limitation the presented coupling method may still be a useful tool in combination with higher resolution atmospheric models as being in development for the successor model CLIMBER-3 and possibly other EMICs. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/14635003 U6 - https://doi.org/10.1016/j.ocemod.2009.03.004 SN - 1463-5003 ER - TY - JOUR A1 - Hille, Carsten A1 - Lahn, Mattes A1 - Löhmannsröben, Hans-Gerd A1 - Dosche, Carsten T1 - Two-photon fluorescence lifetime imaging of intracellular chloride in cockroach salivary glands Y1 - 2009 UR - http://www.rsc.org/Publishing/Journals/pp/index.asp U6 - https://doi.org/10.1039/B813797H SN - 1474-905X ER - TY - JOUR A1 - Ostermeyer, Martin A1 - Korn, Dietmar A1 - Puhlmann, Dirk A1 - Henkel, Carsten A1 - Eisert, Jens T1 - Two-dimensional characterization of spatially entangled photon pairs N2 - We characterize the entanglement in position and momentum of photon pairs generated in type-II parametric down- conversion. Coincidence maps of the photon positions in the near-field and far-field planes are observed in two transverse dimensions using scanning fiber probes. We estimate the covariance matrix of an effective two-mode system and apply criteria for entanglement based on covariance matrices to certify space-momentum entanglement. The role of higher- order spatial modes for observing spatial entanglement between the two photons is discussed. Y1 - 2009 UR - http://www.informaworld.com/openurl?genre=journal&issn=0950-0340 U6 - https://doi.org/10.1080/09500340903359962 SN - 0950-0340 ER - TY - JOUR A1 - Wischerhoff, Erik A1 - Glatzel, Stefan A1 - Uhlig, Katja A1 - Lankenau, Andreas A1 - Lutz, Jean-Francois A1 - Laschewsky, André T1 - Tuning the thickness of polymer brushes grafted from nonlinearly growing multilayer assemblies N2 - A new versatile method for tuning the thickness of surface-tethered polymer brushes is introduced. It is based on the combination of polyelectrolyte multilayer deposition and surface-initiated atom transfer radical polymerization. To control the thickness of the brushes, the nonlinear growth of certain polyelectrolyte multilayer systems is exploited. The method is demonstrated to work with different polyelectrolytes and different monomers. The relevance for applications is demonstrated by cell adhesion experiments oil grafted thermoresponsive polymer layers with varying thickness. Y1 - 2009 UR - http://pubs.acs.org/journal/langd5 U6 - https://doi.org/10.1021/La804197j SN - 0743-7463 ER - TY - JOUR A1 - Kamjunke, Norbert A1 - Vogt, Bernhard A1 - Woelfl, Stefan T1 - Trophic interactions of the pelagic ciliate Stentor spp. in North Patagonian lakes N2 - The zooplankton of oligotrophic lakes in North Patagonia is often dominated by mixotrophic ciliates, particularly Stentor amethystinus and Stentor araucanus. Therefore, we tested whether Stentor spp. (i) is an important food for juvenile endemic (Cheirodon australe, Galaxias maculatus, Odontesthes mauleanum, Percichthys trucha) and introduced (Oncorhynchus mykiss) fish species, and (ii) represents a remarkable grazer of bacteria. Ingestion rates of fish estimated by disappearance of Stentor in feeding experiments ranged between 8 (G. maculatus) and 53 (C australe) ciliates per fish and day, and assimilation rates measured by using radioactively labelled Stentor ranged between 3 (P. trucha) and 52 (C australe) ciliates per fish and day. However, although we detected the consumption of Stentor by fish, the daily consumption amounted to at most 0.2% of the fish biomass which can not cover the energy requirement of the fish. Furthermore, the daily consumption was equivalent to a maximum of 1.6% of the Stentor standing stock so that fish predation does not seem to be an important mortality factor for the ciliates. The clearance rate of Stentor sp. on natural bacteria was on average 3.8 mu l cil(-1) h(-1). The daily ingestion (mean 3.9 ngC cil(-1) d(-1)) was about 3.5% of the individual biomass of Stentor sp. Therefore, bacteria ingestion might explain a ciliate growth rate of appr. 1% d(-1), which was about 17% of the photosynthesis of endosymbiotic algae. The maximum density of Stentor sp. in the take could ingest about 1 mu g C L-1 d(-1) bacteria which is only 3% of average bacterial production. Thus, grazing by Stentor sp. does not seem to be a main loss factor for the bacteria. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00759511 U6 - https://doi.org/10.1016/j.limno.2008.08.001 SN - 0075-9511 ER - TY - JOUR A1 - König, Carolin T1 - TRIPS – als Schutz von oder als Schutz vor Piraten? BT - Verschiedene Blickwinkel auf das internationale Rechtssystem zum Schutz geistigen Eigentums JF - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen N2 - Inhaltsübersicht I. Der Schutz geistigen Eigentums und seine gestiegene Bedeutung im Informationszeitalter II. Die Kehrseite der Medaille – der Schutz geistigen Eigentums im Konflikt mit anderen Menschenrechten III. Die einander entgegenstehenden Menschenrechte und menschenrechtlichen Pflichten IV. Schlussbemerkung Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-35509 SN - 1434-2820 VL - 14 IS - 1 SP - 5 EP - 21 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Scheller, Frieder W. T1 - Tribute to Guenter Gauglitz (Editorial) Y1 - 2009 UR - http://www.springerlink.com/content/100417 U6 - https://doi.org/10.1007/s00216-008-2548-0 SN - 1618-2642 ER - TY - JOUR A1 - Trauth, Martin H. A1 - Larrasoaña, Juan C. A1 - Mudelsee, Manfred T1 - Trends, rhythms and events in plio-pleistocene African climate N2 - We analyzed published records of terrigenous dust flux from marine sediments off subtropical West Africa, the eastern Mediterranean Sea, and the Arabian Sea, and lake records from East Africa using statistical methods to detect trends, rhythms and events in Plio-Pleistocene African climate. The critical reassessment of the environmental significance of dust flux and lake records removes the apparent inconsistencies between marine vs. terrestrial records of African climate variability. Based on these results, major steps in mammalian and hominin evolution occurred during episodes of a wetter, but highly variable climate largely controlled by orbitally induced insolation changes in the low latitudes. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/02773791 U6 - https://doi.org/10.1016/j.quascirev.2008.11.003 SN - 0277-3791 ER - TY - JOUR A1 - Treydte, Anna C. A1 - Grant, Rina C. C. A1 - Jeltsch, Florian T1 - Tree size and herbivory determine below-canopy grass quality and species composition in savannahs N2 - Large single-standing trees are rapidly declining in savannahs, ecosystems supporting a high diversity of large herbivorous mammals. Savannah trees are important as they support both a unique flora and fauna. The herbaceous layer in particular responds to the structural and functional properties of a tree. As shrubland expands stem thickening occurs and large trees are replaced by smaller trees. Here we examine whether small trees are as effective in providing advantages for grasses growing beneath their crowns as large trees are. The role of herbivory in this positive tree- grass interaction is also investigated. We assessed soil and grass nutrient content, structural properties, and herbaceous species composition beneath trees of three size classes and under two grazing regimes in a South African savannah. We found that grass leaf content (N and P) beneath the crowns of particularly large (ca. 3.5 m) and very large trees (ca. 9 m) was as much as 40% greater than the same grass species not growing under a tree canopy, whereas nutrient contents of grasses did not differ beneath small trees (< 2.3 m). Moderate herbivory enhanced these effects slightly. Grass species composition differed beneath and beyond the tree canopy but not between tree size classes. As large trees significantly improve the grass nutrient quality for grazers in contrast to smaller trees, the decline of the former should be halted. The presence of trees further increases grass species diversity and patchiness by favouring shade- tolerant species. Both grazing wildlife and livestock will benefit from the presence of large trees because of their structural and functional importance for savannahs. Y1 - 2009 UR - http://www.springerlink.com/content/100125 U6 - https://doi.org/10.1007/s10531-009-9694-3 SN - 0960-3115 ER - TY - JOUR A1 - Berger, Alfons A1 - Bousquet, Romain A1 - Engi, Martin A1 - Janots, Emilie A1 - Rubatto, Daniela A1 - Schmid, Stefan A1 - Wiederkehr, Michael T1 - Transport of heat and mass in a Barrovian belt : what do we know from nature? Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00167037 U6 - https://doi.org/10.1016/j.gca.2009.05.002 SN - 0016-7037 ER - TY - JOUR A1 - Zhang, Gong A1 - Hubalewska, Magdalena A1 - Ignatova, Zoya T1 - Transient ribosomal attenuation coordinates protein synthesis and co-translational folding N2 - Clustered codons that pair to low-abundance tRNA isoacceptors can form slow-translating regions in the mRNA and cause transient ribosomal arrest. We report that folding efficiency of the Escherichia coli multidomain protein Sufl can be severely perturbed by alterations in ribosome-mediated translational attenuation. Such alterations were achieved by global acceleration of the translation rate with tRNA excess in vitro or by synonymous substitutions to codons with highly abundant tRNAs both in vitro and in vivo. Conversely, the global slow-down of the translation rate modulated by low temperature suppresses the deleterious effect of the altered translational attenuation pattern. We propose that local discontinuous translation temporally separates the translation of segments of the peptide chain and actively coordinates their co-translational folding. Y1 - 2009 UR - http://www.nature.com/nsmb/ U6 - https://doi.org/10.1038/Nsmb.1554 SN - 1545-9985 ER - TY - THES A1 - Zhang, Gong T1 - Transient ribosomal attenuation as a generic mechanism to coordinate protein biosynthesis and biogenesis Y1 - 2009 CY - Potsdam ER - TY - THES A1 - Bange, Sebastian T1 - Transient optical and electrical effects in polymeric semiconductors T1 - Transiente optische und elektrische Effekte in polymeren Halbeitern N2 - Classical semiconductor physics has been continuously improving electronic components such as diodes, light-emitting diodes, solar cells and transistors based on highly purified inorganic crystals over the past decades. Organic semiconductors, notably polymeric, are a comparatively young field of research, the first light-emitting diode based on conjugated polymers having been demonstrated in 1990. Polymeric semiconductors are of tremendous interest for high-volume, low-cost manufacturing ("printed electronics"). Due to their rather simple device structure mostly comprising only one or two functional layers, polymeric diodes are much more difficult to optimize compared to small-molecular organic devices. Usually, functions such as charge injection and transport are handled by the same material which thus needs to be highly optimized. The present work contributes to expanding the knowledge on the physical mechanisms determining device performance by analyzing the role of charge injection and transport on device efficiency for blue and white-emitting devices, based on commercially relevant spiro-linked polyfluorene derivatives. It is shown that such polymers can act as very efficient electron conductors and that interface effects such as charge trapping play the key role in determining the overall device efficiency. This work contributes to the knowledge of how charges drift through the polymer layer to finally find neutral emissive trap states and thus allows a quantitative prediction of the emission color of multichromophoric systems, compatible with the observed color shifts upon driving voltage and temperature variation as well as with electrical conditioning effects. In a more methodically oriented part, it is demonstrated that the transient device emission observed upon terminating the driving voltage can be used to monitor the decay of geminately-bound species as well as to determine trapped charge densities. This enables direct comparisons with numerical simulations based on the known properties of charge injection, transport and recombination. The method of charge extraction under linear increasing voltages (CELIV) is investigated in some detail, correcting for errors in the published approach and highlighting the role of non-idealized conditions typically present in experiments. An improved method is suggested to determine the field dependence of charge mobility in a more accurate way. Finally, it is shown that the neglect of charge recombination has led to a misunderstanding of experimental results in terms of a time-dependent mobility relaxation. N2 - Klassische Halbleiterphysik beschäftigt sich bereits seit mehreren Jahrzehnten erfolgreich mit der Weiterentwicklung elektronischer Bauteile wie Dioden, Leuchtdioden, Solarzellen und Transistoren auf der Basis von hochreinen anorganischen Kristallstrukturen. Im Gegensatz hierzu ist das Forschungsgebiet der organischen, insbesondere der polymeren Halbleiter noch recht jung: Die erste Leuchtdiode auf der Basis von "leitfähigem Plastik" wurde erst 1990 demonstriert. Polymere Halbleiter sind hierbei von besonderem Interesse für hochvolumige Anwendungen im Beleuchtungsbereich, da sie sich kostengünstig herstellen und verarbeiten lassen ("gedruckte Elektronik"). Die vereinfachte Herstellung bedingt dabei eine vergleichsweise geringe Komplexität der Bauteilstruktur und verringert die Optimierungsmöglichkeiten. Die vorliegende Arbeit leistet einen Beitrag zum Verständnis der Vorgänge an Grenzflächen und im Volumen von polymeren Leuchtdioden und ermöglicht damit ein besseres Verständnis der Bauteilfunktion. Im Fokus steht hierbei mit einem spiro-verknüpften Polyfluorenderivat ein kommerziell relevanter Polymertyp, der amorphe und hochgradig temperaturstabile Halbleiterschichten bildet. Ausgehend von einer Charakterisierung der Ladungstransporteigenschaften wird im Zusammenspiel mit numerischen Simulationen der Bauteilemission gezeigt, welche Rolle die polymeren und metallenen Kontaktelektroden für die Bauteilfunktion und -effizienz spielen. Des Weiteren wird ein weiß-emittierendes Polymer untersucht, bei dem die Mischung von blauen, grünen und roten Farbstoffen die Emissionsfarbe bestimmt. Hierbei wird das komplexe Wechselspiel aus Energieübertrag zwischen den Farbstoffen und direktem Ladungseinfang aufgeklärt. Es wird ein quantitatives Modell entwickelt, das die beobachtete Verschiebung der Emissionsfarbe unter wechselnden elektrischen Betriebsparametern erklärt und zusätzlich die Vorhersage von Temperatur- und elektrischen Konditionierungseffekten ermöglicht. Ausgehend von leicht messbaren Parametern wie Stromstärken und Emissionsspektren ermöglicht es Rückschlüsse auf mikroskopische Vorgänge wie die Diffusion von Ladungen hin zu Farbstoffen. Es wird gezeigt, dass im Gegensatz zu bisherigen Erkenntnissen der Ladungseinfang durch Drift im elektrischen Feld gegenüber der Diffusion überwiegt. In einem eher methodisch orientierten Teil zeigt die Arbeit, wie die beim Abschalten von Leuchtdioden beobachtbare Emission dazu verwendet werden kann, Erkenntnisse zu Ladungsdichten während der Betriebsphase zu gewinnen. Es wird abschließend nachgewiesen, dass eine gängige Methode zur Bestimmung von Ladungsbeweglichkeiten unter typischen Messbedingungen fehlerbehaftet ist. Ergebnisse, die bisher als eine zeitliche Relaxation der Beweglichkeit in ungeordneten Halbleitern interpretiert wurden, können damit auf die Rekombination von Ladungen während der Messung zurückgeführt werden. Es wird außerdem gezeigt, dass eine Modifikation der bei der Auswertung verwendeten Analytik die genauere Vermessung der Feldstärkeabhängigkeit der Beweglichkeit ermöglicht. KW - Organische Halbleiter KW - Ladungstransport KW - OLED KW - Polymer Electronics KW - Organic Semiconductors KW - Charge Transport KW - OLED KW - Polymerelektronik Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-36314 ER - TY - THES A1 - Najafabadi, Masood Soltani T1 - Transcription factor networks in the initial ohase of drouht stress in rice (Oryza sativa L.) Y1 - 2009 CY - Potsdam ER - TY - INPR A1 - Eckstein, Lars T1 - Transatlantic slavery and the literary imagination Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-85548 ER - TY - GEN A1 - Eckstein, Lars T1 - Transatlantic slavery and the literary imagination N2 - Transatlantic slavery and the literary imagination The challenges of turning transatlantic slavery into literature A polyphony of historical voices: Caryl Phillips’s dialogic imagination Literary imagination and the Zong Massacre: Fred D’Aguiar and David Dabydeen Perspectives T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 81 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-59201 ER - TY - JOUR A1 - Ette, Ottmar T1 - Transareale Perspektive : Plädoyer für ein neues Verständnis der Tropen Y1 - 2009 ER - TY - JOUR A1 - Stillmark, Hans-Christian T1 - Tragödie mit Gespenstern - Zu Volker Brauns "Iphigenie in Freiheit" Y1 - 2009 SN - 978-3-89754-308-9 ER - TY - JOUR A1 - Scott, James M. A1 - Cooper, Alan F. A1 - Palin, J. Michael A1 - Tulloch, Andy J. A1 - Kula, Joseph L. A1 - Jongens, Richard A1 - Spell, Terry L. A1 - Pearson, Norman J. T1 - Tracking the influence of a continental margin on growth of a magmatic arc, Fiordland, New Zealand, using thermobarometry, thermochronology, and zircon U-Pb and Hf isotopes N2 - Geothermobarometric, radiogenic isotopic and thermochronologic data are used to track the influence of an ancient continental margin (Western Province) on development of an adjacent Carboniferous-Cretaceous magmatic arc (Outboard Median Batholith) in Fiordland, New Zealand. The data show a record of complicated Mesozoic Gondwana margin growth. Paragneiss within the Outboard Median Batholith is of Carboniferous to Jurassic age and records burial to middle crustal depths in Late Jurassic-Early Cretaceous during subduction-related plutonism and arc thickening. In contrast, Western Province metasedimentary rocks in the area of study immediately west of the Outboard Median Batholith are Late Cambrian-Early Ordovician in age, recrystallized at the amphibolite facies in the Late Devonian-Early Carboniferous and exhibit no evidence for Mesozoic textural or isotopic reequilibration. A phase of deformation, between 128 and 116 Ma deformed, exhumed, and cooled the Outboard Median Batholith to greenschist facies temperatures, while large parts of the Western Province underwent >= 9 kbar metamorphic conditions. Zircon grains from Mesozoic inboard plutons are isotopically more evolved (epsilon Hf(t) = +2.3 to +4.0) than those in the Outboard Median Batholith (epsilon Hf(t) = +9.4 to +11.1). The contrasting zircon Hf isotope ratios, absence of S-type plutons or Proterozoic-Early Paleozoic inherited zircon, and the apparent absence of Early Paleozoic metasedimentary rocks indicates that the Outboard Median Batholith is unlikely to be underlain by the Western Province continental lithosphere. The new data are consistent with the Outboard Median Batholith representing an allochthonous (although not necessarily exotic) arc that was juxtaposed onto the Gondwana continental margin along the intervening Grebe Mylonite Zone. Y1 - 2009 UR - http://www.agu.org/journals/tc/ U6 - https://doi.org/10.1029/2009tc002489 SN - 0278-7407 ER - TY - BOOK A1 - Rolfes, Manfred A1 - Steinbrink, Malte A1 - Uhl, Christina T1 - Townships as attraction : an empirical study of township tourism in Cape Town N2 - Since the end of the Apartheid international tourism in South Africa has increasingly gained importance for the national economy. The centre of this PKS issue’s attention is a particular form of tourism: Township tourism, i.e. guided tours to the residential areas of the black population. About 300,000 tourists per year visit the townships of Cape Town. The tours are also called Cultural, Social, or Reality Tours. The different aspects of township tourism in Cape Town were subject of a geographic field study, which was undertaken during a student research project of Potsdam University in 2007. The text at hand presents the empirical results of the field study, and demonstrates how townships are constructed as spaces of tourism. N2 - Seit dem Ende der Apartheid gewinnt in Südafrika der internationale Tourismus eine immer größere ökonomische Bedeutung. In diesem PKS-Heft steht eine besondere Form des Tourismus im Mittelpunkt, der Township Tourismus. Dabei handelt es sich um geführte Touren in die Wohngebiete der schwarzen Bevölkerung. Etwa 300.000 Touristen besuchen in Kapstadt jährlich die Townships. Die Touren werden auch als Cultural, Social oder Reality Tours bezeichnet. Im Jahr 2007 untersuchten Potsdamer Geographen/innen im Rahmen eines Studienprojektes die unterschiedlichen Aspekte des Township Tourismus in Kapstadt. In der vorliegenden Arbeit werden die empirischen Ergebnisse dieses Forschungsaufenthaltes vorgestellt. Es wird gezeigt, wie Townships als touristische Räume konstruiert werden. T3 - Praxis Kultur- und Sozialgeographie | PKS - 46 KW - township tourism KW - South Africa KW - Cape Town KW - spatial construction KW - slumming KW - Township Tourismus KW - Südafrika KW - Kapstadt KW - Raumkonstruktion KW - Slumming Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-28947 SN - 978-3-940793-79-9 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Grimbs, Sergio T1 - Towards structure and dynamics of metabolic networks T1 - Struktur und Dynamik metabolischer Netzwerke N2 - This work presents mathematical and computational approaches to cover various aspects of metabolic network modelling, especially regarding the limited availability of detailed kinetic knowledge on reaction rates. It is shown that precise mathematical formulations of problems are needed i) to find appropriate and, if possible, efficient algorithms to solve them, and ii) to determine the quality of the found approximate solutions. Furthermore, some means are introduced to gain insights on dynamic properties of metabolic networks either directly from the network structure or by additionally incorporating steady-state information. Finally, an approach to identify key reactions in a metabolic networks is introduced, which helps to develop simple yet useful kinetic models. The rise of novel techniques renders genome sequencing increasingly fast and cheap. In the near future, this will allow to analyze biological networks not only for species but also for individuals. Hence, automatic reconstruction of metabolic networks provides itself as a means for evaluating this huge amount of experimental data. A mathematical formulation as an optimization problem is presented, taking into account existing knowledge and experimental data as well as the probabilistic predictions of various bioinformatical methods. The reconstructed networks are optimized for having large connected components of high accuracy, hence avoiding fragmentation into small isolated subnetworks. The usefulness of this formalism is exemplified on the reconstruction of the sucrose biosynthesis pathway in Chlamydomonas reinhardtii. The problem is shown to be computationally demanding and therefore necessitates efficient approximation algorithms. The problem of minimal nutrient requirements for genome-scale metabolic networks is analyzed. Given a metabolic network and a set of target metabolites, the inverse scope problem has as it objective determining a minimal set of metabolites that have to be provided in order to produce the target metabolites. These target metabolites might stem from experimental measurements and therefore are known to be produced by the metabolic network under study, or are given as the desired end-products of a biotechological application. The inverse scope problem is shown to be computationally hard to solve. However, I assume that the complexity strongly depends on the number of directed cycles within the metabolic network. This might guide the development of efficient approximation algorithms. Assuming mass-action kinetics, chemical reaction network theory (CRNT) allows for eliciting conclusions about multistability directly from the structure of metabolic networks. Although CRNT is based on mass-action kinetics originally, it is shown how to incorporate further reaction schemes by emulating molecular enzyme mechanisms. CRNT is used to compare several models of the Calvin cycle, which differ in size and level of abstraction. Definite results are obtained for small models, but the available set of theorems and algorithms provided by CRNT can not be applied to larger models due to the computational limitations of the currently available implementations of the provided algorithms. Given the stoichiometry of a metabolic network together with steady-state fluxes and concentrations, structural kinetic modelling allows to analyze the dynamic behavior of the metabolic network, even if the explicit rate equations are not known. In particular, this sampling approach is used to study the stabilizing effects of allosteric regulation in a model of human erythrocytes. Furthermore, the reactions of that model can be ranked according to their impact on stability of the steady state. The most important reactions in that respect are identified as hexokinase, phosphofructokinase and pyruvate kinase, which are known to be highly regulated and almost irreversible. Kinetic modelling approaches using standard rate equations are compared and evaluated against reference models for erythrocytes and hepatocytes. The results from this simplified kinetic models can simulate acceptably the temporal behavior for small changes around a given steady state, but fail to capture important characteristics for larger changes. The aforementioned approach to rank reactions according to their influence on stability is used to identify a small number of key reactions. These reactions are modelled in detail, including knowledge about allosteric regulation, while all other reactions were still described by simplified reaction rates. These so-called hybrid models can capture the characteristics of the reference models significantly better than the simplified models alone. The resulting hybrid models might serve as a good starting point for kinetic modelling of genome-scale metabolic networks, as they provide reasonable results in the absence of experimental data, regarding, for instance, allosteric regulations, for a vast majority of enzymatic reactions. N2 - In dieser Arbeit werden mathematische und informatische Ansätze zur Behandlung diverser Probleme im Zusammenhang mit der Modellierung metabolischer Netzwerke vorgestellt, insbesondere unter Berücksichtigung der eingeschränkten Verfügbarkeit detaillierter Enzymkinetiken. Es wird gezeigt, dass präzise mathematische Formulierungen der Probleme notwendig sind, um erstens angemessene und, falls möglich, effiziente Algorithmen zur Lösung zu entwickeln. Und zweitens, um die Güte der so gefundenen Lösungen zu bewerten. Des weiteren werden Methoden zur Analyse dynamischer Eigenschaften metabolischer Netzwerke eingeführt, welche entweder nur auf der Struktur der Netzwerke basieren oder zusätzlich noch Informationen über stationäre Zustände mit berücksichtigen. Außerdem wird eine Strategie zur Bestimmung von Schlüsselreaktionen eines Netzwerkes vorgestellt, welche die Entwicklung kinetischer Modelle vereinfacht. Der Erfolg neuer Technologien ermöglicht eine immer billigere und schnellere Sequenzierung des Genoms. Dies wird in naher Zukunft die Analyse biologischer Netzwerke nicht nur für Spezies, sondern auch für einzelne Individuen ermöglichen. Die automatische Rekonstruktion metabolischer Netzwerke ist bestens dafür geeignet, diese großen Datenmengen auszuwerten. Eine mathematische Formulierung der Rekonstruktion als Optimierungsproblem wird vorgestellt, die sowohl bereits vorhandenes Wissen als auch theoretische Vorhersagen verschiedenster bioinformatischer Methoden berücksichtigt. Die rekonstruierten Netzwerke sind hinsichtlich möglichst großer und plausibler Zusammenhangskomponenten hin optimiert, um fragmentierte und isolierte Teilnetzwerke zu vermeiden. Als Beispiel dient die Rekonstruktion der Saccharosesynthese in Chlamydomonas reinhardtii. Es wird gezeigt, dass das Problem sehr rechenintensiv ist und somit Approximationsalgorithmen erforderlich macht. Das 'inverse scope' Problem hat als Optimierungsziel, für ein gegebenes metabolisches Netzwerk die minimale Menge notwendiger Metabolite zu bestimmen, um eine ebenfalls gegebene Menge von gewünschten Zielmetaboliten zu produzieren. Diese Zielmetabolite können entweder durch experimentellen Messungen festgelegt werden, oder sie sind die gewünschten Endprodukte einer biotechnologischen Anwendung. Es wird gezeigt, dass das 'inverse scope' Problem rechenintensiv ist. Allerdings wird angenommen, dass die Berechnungskomplexität stark von der Anzahl gerichteter Zyklen innerhalb des metabolischen Netzwerkes abhängt. Dies könnte die Entwicklung effizienter Approximationsalgorithmen ermöglichen. Unter der Annahme von Massenwirkungskinetiken erlaubt es die 'chemical reaction network theory' (CRNT), anhand der Struktur metabolischer Netzwerke Rückschlüsse auf Multistabilität zu ziehen. Auch weitere Kinetiken können durch Modellierung von Enzymmechanismen mit berücksichtigt werden. CRNT wird zum Vergleich von mehreren Modellen des Calvinzyklus, welche sich in Größe und Abstraktionsniveau unterscheiden, verwendet. Obwohl für kleinere Modelle Ergebnisse erzielt werden, erlauben es die verfügbaren Theoreme und Algorithmen der CRNT nicht, Aussagen für größere Modelle zu machen, da die gegenwärtigen Implementierungen der Algorithmen an ihre Berechnungsgrenzen stoßen. Sind sowohl die Stoichiometrie eines metabolischen Netzwerkes, als auch die Metabolitkonzentrationen und Flüsse im stationären Zustand bekannt, so kann 'structural kinetic modelling' angewandt werden, um das dynamische Verhalten des Netzwerkes zu analysieren, selbst wenn die expliziten Ratengleichung unbekannt sind. Dieser Ansatz wird verwendet, um den stabilisierenden Einfluss allosterischer Regulation in menschlichen Erythrozyten zu untersuchen. Des weiteren werden die Reaktionen anhand ihrer Bedeutung hinsichtlich Stabilität im stationären Zustand angeordnet. Die wichtigsten Reaktionen bezüglich dieser Ordnung sind Hexokinase, Phosphofructokinase und Pyruvatkinase, welche bekanntermaßen stark reguliert und irreversibel sind. Kinetische Modelle, die auf generischen Ratengleichung beruhen, werden mit detaillierten Referenzmodellen für Erythrozyten und Hepatozyten verglichen. Die generischen Modelle simulieren das Verhalten nur in der Nähe eines gegebenen stationären Zustandes recht gut. Der zuvor erwähnte Ansatz, wichtige Reaktionen bezüglich Stabilität zu identifizieren, wird zur Bestimmung von Schlüsselreaktionen genutzt. Diese Schlüsselreaktionen werden im Detail modelliert, während für alle anderen Reaktionen weiterhin generische Ratengleichung verwendet werden. Die so entstandenen Hybridmodelle können das Verhalten des Referenzmodells signifikant besser beschreiben. Die Hybridmodelle können als Ausgangspunkt zur Erstellung genomweiter kinetischer Modelle dienen. KW - metabolische Netzwerke KW - Modellierung KW - Struktur KW - Dynamik KW - Bioinformatik KW - metabolic networks KW - modelling KW - structure KW - dynamics KW - bioinformatics Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32397 ER - TY - JOUR A1 - Goldobin, Denis S. A1 - Zaikin, Alexey T1 - Towards quantitative prediction of proteasomal digestion patterns of proteins N2 - We discuss the problem of proteasomal degradation of proteins. Though proteasomes are important for all aspects of cellular metabolism, some details of the physical mechanism of the process remain unknown. We introduce a stochastic model of the proteasomal degradation of proteins, which accounts for the protein translocation and the topology of the positioning of cleavage centers of a proteasome from first principles. For this model we develop a mathematical description based on a master equation and techniques for reconstruction of the cleavage specificity inherent to proteins and the proteasomal translocation rates, which are a property of the proteasome species, from mass spectroscopy data on digestion patterns. With these properties determined, one can quantitatively predict digestion patterns for new experimental set-ups. Additionally we design an experimental set-up for a synthetic polypeptide with a periodic sequence of amino acids, which enables especially reliable determination of translocation rates. Y1 - 2009 UR - http://iopscience.iop.org/1742-5468/ U6 - https://doi.org/10.1088/1742-5468/2009/01/P01009 SN - 1742-5468 ER - TY - BOOK A1 - Linz, Juan José T1 - Totalitäre und autoritäre Regime T3 - Potsdamer Textbücher Y1 - 2009 SN - 978-3-941880-00-9 VL - 4 PB - WeltTrends CY - Potsdam ER - TY - GEN A1 - Eckstein, Lars T1 - Torpedoing the authorship of popular music : a reading of Gorillaz’ ‘Feel Good Inc.’ N2 - This article addresses problems of authorship and creative authority in popular music, in particular in view of a pervasive split between modes of aesthetic production (involving modernist assemblage, multiple authorship, and the late capitalist logic of major label policies) and modes of aesthetic reception (which tend to take popular music as the organic output of individual performers). While rock musicians have attempted to come to terms with this phenomenon by either performing a ‘Romantic’ sense of authenticity (basically by importing folk values to the production process) or ‘Modernist authenticity’ (by highlighting experimen- tation and alienation), Damon Albarn and Jamie Hewlett, creators of Gorillaz, found a third way which ingeniously allows them to do both. By creating a virtual rock band, and by hiding their own media personalities behind those of their virtual alter egos, they brought themselves into a position which allows them to produce ‘sincere’ popular music which ‘playfully’ stages the absurdities of major label music business while very successfully operating within its very confines. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 80 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-59116 ER - TY - JOUR A1 - Elsner, Birgit T1 - Tools and goals : a social-cognition perspective on infant learning of object function Y1 - 2009 SN - 978-1-405-16217-3 ER - TY - THES A1 - Apfelbache, Rémy T1 - Tolerierbare Inkonsistenzen in Konzeptbeschreibungen Y1 - 2009 CY - Potsdam ER - TY - JOUR A1 - Bahlburg, Heinrich A1 - Vervoort, Jeffrey D. A1 - du Frane, S. Andrew A1 - Bock, Barbara A1 - Augustsson, Carita A1 - Reimann, Cornelia T1 - Timing of crust formation and recycling in accretionary orogens : insights learned from the western margin of South America N2 - Accretionary orogens are considered major sites of formation of juvenile continental crust. In the central and southern Andes this is contradicted by two observations: siliciclastic fills of Paleozoic basins in the central Andean segment of the accretionary Terra Australis Orogen consist almost exclusively of shales and mature sandstones; and magmatic rocks connected to the Famatinian (Ordovician) and Late Paleozoic magmatic arcs are predominantly felsic and characterized by significant crustal contamination and strongly unradiogenic Nd isotope compositions. Evidence of juvenile crustal additions is scarce. We present laser ablation (LA)-ICPMS U-Pb ages and LA-MC-ICPMS Hf isotope data of detrital zircons from seven Devonian to Permian turbidite sandstones incorporated into a Late Paleozoic accretionary wedge at the western margin of Gondwana in northern Chile. The combination with Nd whole-rock isotope data permits us to trace the evolution of the South American continental crust through several Proterozoic and Paleozoic orogenic cycles. The analyzed detrital zircon spectra reflect all Proterozoic orogenic cycles representing the step-wise evolution of the accretionary SW Amazonia Orogenic System between 2.0 and 0.9 Ga, followed by the Terra Australis Orogen between 0.9 and 0.25 Ga. The zircon populations are characterized by two prominent maxima reflecting input from Sunsas (Grenville) age magmatic rocks (1.2-0.9 Ga) and from the Ordovician to Silurian Famatinian magmatic arc (0.52-0.42 Ga). Grains of Devonian age are scarce or absent from the analyzed zircon populations. The Hf isotopic compositions of selected dated zircons at the time of their crystallization (epsilon Hf-(T); T = 3.3-0.25 Ga) vary between -18 and +11. All sandstones have a significant juvenile component; between 20 and 50% of the zircons from each sedimentary rock have positive epsilon Hf-(T) and can be considered juvenile. The majority of the juvenile grains have Hf-depleted mantle model ages (Hf T-DM) between 1.55 and 0.8 Ga. the time of the Rondonia-San Ignacio and Sunsas orogenic events on the Amazonia craton. The corresponding whole-rock epsilon Nd-(T) values fot these same rocks are between -8 and -3 indicating a mixture of older evolved and juvenile sources. Nd-depleted mantle model ages (Nd T-DM*) are between 1.5 and 1.2 Ga and coincide broadly with the zircon Hf model ages. Our data indicate that the Paleo- and Mesoproterozoic SW Amazonia Orogenic System, and the subsequent Neoproterozoic and Paleozoic Terra Australis Orogen in the region of the central and southern Andes, developed following two markedly different patterns of accretionary orogenic crustal evolution. The SW Amazonia Orogenic System developed by southwestward growth over approximately 1.1 Ga through a combination of accretion of juvenile material and crustal recycling typical of the extensional or retreating mode of accretionary orogens. In contrast, the central Andean segment of the Terra Australis Orogen evolved from 0.9 to 0.25 Ga in the compressional or advancing mode in a relatively fixed position without the accretion of oceanic crustal units or large scale input of juvenile material to the orogenic crust. Here, recycling mainly of Mesoproterozoic continental crust has been the dominant process of crustal evolution. (C) 2009 Elsevier B.V. All rights reserved. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00128252 U6 - https://doi.org/10.1016/j.earscirev.2009.10.006 SN - 0012-8252 ER - TY - GEN A1 - Koseska, Aneta A1 - Zaikin, Alexey A1 - Kurths, Jürgen A1 - García-Ojalvo, Jordi T1 - Timing cellular decision making under noise via cell-cell communication N2 - Many cellular processes require decision making mechanisms, which must act reliably even in the unavoidable presence of substantial amounts of noise. However, the multistable genetic switches that underlie most decision-making processes are dominated by fluctuations that can induce random jumps between alternative cellular states. Here we show, via theoretical modeling of a population of noise-driven bistable genetic switches, that reliable timing of decision-making processes can be accomplished for large enough population sizes, as long as cells are globally coupled by chemical means. In the light of these results, we conjecture that cell proliferation, in the presence of cell-cell communication, could provide a mechanism for reliable decision making in the presence of noise, by triggering cellular transitions only when the whole cell population reaches a certain size. In other words , the summation performed by the cell population would average out the noise and reduce its detrimental impact. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 148 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45260 ER - TY - INPR A1 - Louis, Pierre-Yves A1 - Rouquier, Jean-Baptiste T1 - Time-to-Coalescence for interacting particle systems : parallel versus sequential updating N2 - Studying the influence of the updating scheme for MCMC algorithm on spatially extended models is a well known problem. For discrete-time interacting particle systems we study through simulations the effectiveness of a synchronous updating scheme versus the usual sequential one. We compare the speed of convergence of the associated Markov chains from the point of view of the time-to-coalescence arising in the coupling-from-the-past algorithm. Unlike the intuition, the synchronous updating scheme is not always the best one. The distribution of the time-to-coalescence for these spatially extended models is studied too. T3 - Mathematische Statistik und Wahrscheinlichkeitstheorie : Preprint - 2009, 03 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-49454 ER - TY - JOUR A1 - Paramonov, Guennaddi K. A1 - Saalfrank, Peter T1 - Time-evolution operator method for non-Markovian density matrix propagation in time and space representation : application to laser association of OH in an environment N2 - An efficient method for the numerical solution of a non-Markovian, open-system density matrix equation of motion in coordinate representation is developed. We apply the scheme to model simulations of the laser-assisted O+H -> OH association reaction in an environment. The suggested approach is based on the application of the time-evolution operator to the "closed-system" part of the overall Hamiltonian and transformation of the open-system equation of motion to the Heisenberg picture suitable for numerical propagation. A dual role of the system-environment coupling with respect to the infrared (ir) laser-driven association of OH is demonstrated: the association probability is increased due to the coupling at relatively weak laser fields, but decreased at strong laser fields. Moreover, at a certain strength of the ir laser field, the association probability does not depend on the strength of the system-bath coupling at all. Y1 - 2009 UR - http://pra.aps.org/ U6 - https://doi.org/10.1103/Physreva.79.013415 SN - 1050-2947 ER - TY - THES A1 - Hakimhashemi, Amir Hossein T1 - Time-dependent occurrence rates of large earthquakes in the Dead Sea fault zone and applications to probabilistic seismic hazard assessments T1 - Zeitabhängige Auftretensrate großer Erdbeben entlang der Tote-Meer-Störungszone und ihre Einbeziehung in eine probabilistische seismische Gefährdungseinschätzung N2 - Die relativ hohe seismische Aktivität der Tote-Meer-Störungszone (Dead Sea Fault Zone - DSFZ) ist mit einem hohen Gefahrenpotential verbunden, welches zu einem erheblichen Erdbebenrisiko für die Ballungszentren in den Ländern Syrien, Libanon, Palästina, Jordanien und Israel führt. Eine Vielzahl massiver, zerstörerischer Erdbeben hat sich in diesem Raum in den letzten zwei Jahrtausenden ereignet. Ihre Wiederholungsrate zeigt Anzeichen für eine zeitliche Abhängigkeit, insbesondere wenn lange Zeiträume in Betracht gezogen werden. Die Berücksichtigung der zeitlichen Abhängigkeit des Auftretens von Erdbeben ist für eine realistische seismische Gefährdungseinschätzung von großer Bedeutung. Ziel der vorliegenden Arbeit ist es, anhand des zeitabhängigen Auftretens von Erdbeben eine robuste wahrscheinlichkeitstheoretische seismische Gefährdungseinschätzung am Beispiel der DSFZ zu entwickeln. Mittels dieser Methode soll die zeitliche Abhängigkeit des Auftretens von großen Erdbeben (Mw ≥ 6) untersucht und somit eine Gefährdungseinschätzung für das Untersuchungsgebiet getroffen werden. Primär gilt es zu prüfen, ob das Auftreten von großen Erdbeben tatsächlich einer zeitlichen Abhängigkeit unterliegt und wenn ja, inwiefern diese bestimmt werden kann. Zu diesem Zweck werden insgesamt vier zeitabhängige statistische Verteilungen (Weibull, Gamma, Lognormal und Brownian Passage Time (BPT)) sowie die zeitunabhängige Exponentialverteilung (Poisson-Prozess) getestet. Zur Abschätzung der jeweiligen Modellparameter wird eine modifizierte Methode der gewichteten Maximum-Likelihood-Schätzung (MLE) verwendet. Um einzuschätzen, ob die Wiederholungsrate von Erdbeben einer unimodalen oder multimodalen Form folgt, wird ein nichtparametrischer Bootstrap-Test für Multimodalität durchgeführt. Im Falle einer multimodalen Form wird neben der MLE zusätzlich eine Erwartungsmaximierungsmethode (EM) herangezogen. Zur Auswahl des am besten geeigneten Modells wird zum einem das Bayesschen Informationskriterium (BIC) und zum anderen der modifizierte Kolmogorow-Smirnow-Goodness-of-Fit-Test angewendet. Abschließend werden mittels der Bootstrap-Methode die Konfidenzintervalle der geschätzten Parameter berechnet. Als Datengrundlage werden Erdbeben mit Mw ≥ 6 seit dem Jahre 300 n. Chr. herangezogen. Das Untersuchungsgebiet erstreckt sich von 29.5° N bis 37° N und umfasst ein ca. 40 km breites Gebiet entlang der DSFZ. Aufgrund der seismotektonischen Situation im Untersuchungsgebiet wird zwischen einer südlichen, zentralen und nördlichen Subzone unterschieden. Dabei kann die südliche Subzone aus Mangel an Daten nicht für die Analysen herangezogen werden. Die Ergebnisse für die zentrale Subzone zeigen keinen signifikanten multimodalen Verlauf der Wiederholungsrate von Erdbeben. Des Weiteren ist kein signifikanter Unterschied zwischen den zeitabhängigen und dem zeitunabhängigem Modell zu verzeichnen. Da das zeitunabhängige Modell vergleichsweise einfach interpretierbar ist, wird die Wiederholungsrate von Erdbeben in dieser Subzone unter Annahme der Exponentialverteilungs-Hypothese abgeschätzt. Sie wird demnach als zeitunabhängig betrachtet und beträgt 9.72 * 10-3 Erdbeben (mit Mw ≥ 6) pro Jahr. Einen besonderen Fall stellt die nördliche Subzone dar. In diesem Gebiet tritt im Durchschnitt alle 51 Jahre ein massives Erdbeben (Mw ≥ 6) auf. Das letzte Erdbeben dieser Größe ereignete sich 1872 und liegt somit bereits 137 Jahre zurück. Somit ist in diesem Gebiet ein Erdbeben dieser Stärke überfällig. Im statistischen Mittel liegt die Zeit zwischen zwei Erdbeben zu 96% unter 137 Jahren. Zudem wird eine deutliche zeitliche Abhängigkeit der Erdbeben-Wiederauftretensrate durch die Ergebnisse der in der Arbeit neu entwickelten statistischen Verfahren bestätigt. Dabei ist festzustellen, dass die Wiederholungsrate insbesondere kurz nach einem Erdbeben eine sehr hohe zeitliche Abhängigkeit aufweist. Am besten repräsentiert werden die seismischen Bedingungen in der genannten Subzone durch ein bi-modales Weibull-Weibull-Modell. Die Wiederholungsrate ist eine glatte Zeitfunktion, welche zwei Häufungen von Datenpunkten in der Zeit nach dem Erdbeben zeigt. Dabei umfasst die erste Häufung einen Zeitraum von 80 Jahren, ausgehend vom Zeitpunkt des jeweiligen Bebens. Innerhalb dieser Zeitspanne ist die Wiederholungsrate extrem zeitabhängig. Die Wiederholungsrate direkt nach einem Beben ist sehr niedrig und steigert sich in den folgenden 10 Jahren erheblich bis zu einem Maximum von 0.024 Erdbeben/Jahr. Anschließend sinkt die Rate und erreicht ihr Minimum nach weiteren 70 Jahren mit 0.0145 Erdbeben/Jahr. An dieses Minimum schließt sich die zweite Häufung von Daten an, dessen Dauer abhängig von der Erdbebenwiederholungszeit ist. Innerhalb dieses Zeitfensters nimmt die Erdbeben-Wiederauftretensrate annähernd konstant um 0.015 Erdbeben/Jahr zu. Diese Ergebnisse bilden die Grundlage für eine zeitabhängige probabilistische seismische Gefährdungseinschätzung (PSHA) für die seismische Quellregion, die den nördlichen Raum der DSFZ umfasst. N2 - The seismicity of the Dead Sea fault zone (DSFZ) during the last two millennia is characterized by a number of damaging and partly devastating earthquakes. These events pose a considerable seismic hazard and seismic risk to Syria, Lebanon, Palestine, Jordan, and Israel. The occurrence rates for large earthquakes along the DSFZ show indications to temporal changes in the long-term view. The aim of this thesis is to find out, if the occurrence rates of large earthquakes (Mw ≥ 6) in different parts of the DSFZ are time-dependent and how. The results are applied to probabilistic seismic hazard assessments (PSHA) in the DSFZ and neighboring areas. Therefore, four time-dependent statistical models (distributions), including Weibull, Gamma, Lognormal and Brownian Passage Time (BPT), are applied beside the exponential distribution (Poisson process) as the classical time-independent model. In order to make sure, if the earthquake occurrence rate follows a unimodal or a multimodal form, a nonparametric bootstrap test of multimodality has been done. A modified method of weighted Maximum Likelihood Estimation (MLE) is applied to estimate the parameters of the models. For the multimodal cases, an Expectation Maximization (EM) method is used in addition to the MLE method. The selection of the best model is done by two methods; the Bayesian Information Criterion (BIC) as well as a modified Kolmogorov-Smirnov goodness-of-fit test. Finally, the confidence intervals of the estimated parameters corresponding to the candidate models are calculated, using the bootstrap confidence sets. In this thesis, earthquakes with Mw ≥ 6 along the DSFZ, with a width of about 20 km and inside 29.5° ≤ latitude ≤ 37° are considered as the dataset. The completeness of this dataset is calculated since 300 A.D. The DSFZ has been divided into three sub zones; the southern, the central and the northern sub zone respectively. The central and the northern sub zones have been investigated but not the southern sub zone, because of the lack of sufficient data. The results of the thesis for the central part of the DSFZ show that the earthquake occurrence rate does not significantly pursue a multimodal form. There is also no considerable difference between the time-dependent and time-independent models. Since the time-independent model is easier to interpret, the earthquake occurrence rate in this sub zone has been estimated under the exponential distribution assumption (Poisson process) and will be considered as time-independent with the amount of 9.72 * 10-3 events/year. The northern part of the DSFZ is a special case, where the last earthquake has occurred in 1872 (about 137 years ago). However, the mean recurrence time of Mw ≥ 6 events in this area is about 51 years. Moreover, about 96 percent of the observed earthquake inter-event times (the time between two successive earthquakes) in the dataset regarding to this sub zone are smaller than 137 years. Therefore, it is a zone with an overdue earthquake. The results for this sub zone verify that the earthquake occurrence rate is strongly time-dependent, especially shortly after an earthquake occurrence. A bimodal Weibull-Weibull model has been selected as the best fit for this sub zone. The earthquake occurrence rate, corresponding to the selected model, is a smooth function of time and reveals two clusters within the time after an earthquake occurrence. The first cluster begins right after an earthquake occurrence, lasts about 80 years, and is explicitly time-dependent. The occurrence rate, regarding to this cluster, is considerably lower right after an earthquake occurrence, increases strongly during the following ten years and reaches its maximum about 0.024 events/year, then decreases over the next 70 years to its minimum about 0.0145 events/year. The second cluster begins 80 years after an earthquake occurrence and lasts until the next earthquake occurs. The earthquake occurrence rate, corresponding to this cluster, increases extremely slowly, such as it can be considered as an almost constant rate about 0.015 events/year. The results are applied to calculate the time-dependent PSHA in the northern part of the DSFZ and neighbouring areas. KW - Zeitanhängig KW - seismische Gefährdung KW - Tote Meer KW - Auftretensrate KW - Erdbeben KW - time dependent KW - seismic hazard KW - Dead Sea KW - occurrence rate KW - earthquake Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-52486 ER - TY - JOUR A1 - Kaspers, Birte T1 - Till Müller-Heidelberg u. a. (Hrsg.), Grundrechte-Report 2009 ; Heiner Bielefeldt u. a. (Hrsg.), Jahrbuch Menschenrechte 2009 / [rezensiert von] Birte Kaspers JF - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen N2 - Rezensierte Werke: Till Müller-Heidelberg u. a. (Hrsg.), Grundrechte-Report 2009 – Zur Lage der Bürger- und Menschenrechte in Deutschland, Fischer Taschenbuch Verlag, 2009, 272 Seiten, ISBN 978- 3-596-18373-9, 9,95 €; Heiner Bielefeldt u. a. (Hrsg.), Jahrbuch Menschenrechte 2009 – Religionsfreiheit, Böhlau Verlag, 2008, 293 Seiten, ISBN 978-3-205-78190-5, 19,90 €. Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-40171 SN - 1434-2820 VL - 14 IS - 2 SP - 264 EP - 266 ER - TY - JOUR A1 - Marwan, Norbert A1 - Kurths, Jürgen A1 - Thomsen, Jesper Skovhus A1 - Felsenberg, Dieter A1 - Saparin, Peter T1 - Three-dimensional quantification of structures in trabecular bone using measures of complexity N2 - The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three-dimensional (3D) imaging of bone challenges the development of data analysis techniques able to assess changes of the 3D microarchitecture of trabecular bone. We introduce an approach based on spatial geometrical properties and define structural measures of complexity for 3D image analysis. These measures evaluate different aspects of organization and complexity of 3D structures, such as complexity of its surface or shape variability. We apply these measures to 3D data acquired by high-resolution microcomputed tomography (mu CT) from human proximal tibiae and lumbar vertebrae at different stages of osteoporotic bone loss. The outcome is compared to the results of conventional static histomorphometry and exhibits clear relationships between the analyzed geometrical features of trabecular bone and loss of bone density, but also indicate that the measures reveal additional information about the structural composition of bone, which were not revealed by the static histomorphometry. Finally, we have studied the dependency of the developed measures of complexity on the spatial resolution of the mu CT data sets. Y1 - 2009 UR - http://pre.aps.org/ U6 - https://doi.org/10.1103/Physreve.79.021903 SN - 1539-3755 ER - TY - JOUR A1 - Grözinger, Karl E. T1 - Thomas Meyer: Vom Ende der Emanzipation. Jüdische Philosophie und Theologie nach 1933 / [rezensiert von] Karl E. Grözinger JF - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien e.V. N2 - rezensiertes Werk: Meyer, Thomas: Vom Ende der Emanzipation : Jüdische Philosophie und Theologie nach 1933. - Göttingen : Vandenhoeck & Ruprecht, 2008. - 207 S. ISBN 978-3-525-35094-2 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-38086 SN - 1614-6492 SN - 1862-7684 IS - 15 SP - 163 EP - 166 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Frank, Ulrike T1 - Therapie bei tracheotomierten Patienten mit schwerer Dysphagie JF - Spektrum Patholinguistik N2 - Inhalt: 1. Einleitung 2. Fragestellungen 3. Methoden 3.1 Methodisches Vorgehen: Interdisziplinäre Trachealkanülenentwöhnung und Dekanülierungsentscheidung im Basler Ansatz 3.2 Methodisches Vorgehen: Probanden und Messverfahren 4. Ergebnisse 4.1 Effektivität und Effizienz des multidisziplinären Ansatzes: Dekanülierungs- und Komplikationsraten und Therapiedauer bis zur Dekanülierung 4.2 Einfluss der Dekanülierung auf den Rehabilitationsverlauf funktioneller Fähigkeiten: Vergleich der funktionellen Selbständigkeit vor vs. nach der Dekanülierung 4.3 Entwicklung der Schluckfunktion und oralen Nahrungsaufnahme nach der Dekanülierung 5. Diskussion 6. Fazit 7. Literatur 8. Danksagung KW - Patholinguistik KW - Bilingualismus KW - Mehrsprachigkeit KW - Sprachtherapie KW - Sprachförderung KW - patholinguistics KW - bilingualism KW - speech and language therapy Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32654 SN - 1866-9085 SN - 1866-9433 VL - 2 SP - 95 EP - 112 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - BOOK A1 - Frank, Ulrike T1 - Theraphie bei tracheotomierteen Patienten mit schwerer Dysphagie Y1 - 2009 ER - TY - JOUR A1 - Hafner, Johann Evangelist T1 - Theologie und Religionswissenschaft : ein Vorschlag zur Integration jener in diese Y1 - 2009 SN - 978-3-402-12812-1 ER - TY - JOUR A1 - Gliwicka, Marta A1 - Balazadeh, Salma A1 - Caldana, Camila A1 - Müller-Röber, Bernd A1 - Gaj, Malgorzata D. T1 - The use of multi-qPCR platform and tan1 mutant in identification of TF genes involved in somatic embryogenesis in Arabidopsis Y1 - 2009 UR - http://www.ib.uj.edu.pl/abc/index.php?d=06 SN - 0001-5296 ER - TY - THES A1 - Sennema-Skowronek, Anke T1 - The use of focus markers in second language word processing T1 - Der Gebrauch von Fokusmarkierungen in der fremdsprachlichen Wortverarbeitung N2 - There are many factors which make speaking and understanding a second language (L2) a highly complex challenge. Skills and competencies in in both linguistic and metalinguistic areas emerge as parts of a multi-faceted, flexible concept underlying bilingual/multilingual communication. On the linguistic level, a combination of an extended knowledge of idiomatic expressions, a broad lexical familiarity, a large vocabulary size, and the ability to deal with phonetic distinctions and fine phonetic detail has been argued necessary for effective nonnative comprehension of spoken language. The scientific interest in these factors has also led to more interest in the L2’s information structure, the way in which information is organised and packaged into informational units, both within and between clauses. On a practical level, the information structure of a language can offer the means to assign focus to a certain element considered important. Speakers can draw from a rich pool of linguistic means to express this focus, and listeners can in turn interpret these to guide them to the highlighted information which in turn facilitates comprehension, resulting in an appropriate understanding of what has been said. If a speaker doesn’t follow the principles of information structure, and the main accent in a sentence is placed on an unimportant word, then there may be inappropriate information transfer within the discourse, and misunderstandings. The concept of focus as part of the information structure of a language, the linguistic means used to express it, and the differential use of focus in native and nonnative language processing are central to this dissertation. Languages exhibit a wide range of ways of directing focus, including by prosodic means, by syntactic constructions, and by lexical means. The general principles underlying information structure seem to contrast structurally across different languages, and they can also differ in the way they express focus. In the context of L2 acquisition, characteristics of the L1 linguistic system are argued to influence the acquisition of the L2. Similarly, the conceptual patterns of information structure of the L1 may influence the organization of information in the L2. However, strategies and patterns used to exploit information structure for succesful language comprehension in the native L1, may not apply at all, or work in different ways or todifferent degrees in the L2. This means that L2 learners ideally have to understand the way that information structure is expressed in the L2 to fully use the information structural benefit in the L2. The knowledge of information structural requirements in the L2 could also imply that the learner would have to make adjustments regarding the use of information structural devices in the L2. The general question is whether the various means to mark focus in the learners’ native language are also accessible in the nonnative language, and whether a L1-L2 transfer of their usage should be considered desirable. The current work explores how information structure helps the listener to discover and structure the forms and meanings of the L2. The central hypothesis is that the ability to access information structure has an impact on the level of the learners’ appropriateness and linguistic competence in the L2. Ultimately, the ability to make use of information structure in the L2 is believed to underpin the L2 learners’ ability to effectively communicate in the L2. The present study investigated how use of focus markers affects processing speed and word recall recall in a native-nonnative language comparison. The predominant research question was whether the type of focus marking leads to more efficient and accurate word processing in marked structures than in unmarked structures, and whether differences in processing patterns can be observed between the two language conditions. Three perception studies were conducted, each concentrating on one of the following linguistic parameters: 1. Prosodic prominence: Does prosodic focus conveyed by sentence accent and by word position facilitate word recognition? 2. Syntactical means: Do cleft constructions result in faster and more accurate word processing? 3. Lexical means: Does focus conveyed by the particles even/only (German: sogar/nur) facilitate word processing and word recall? Experiments 2 and 3 additionally investigated the contribution of context in the form of preceding questions. Furthermore, they considered accent and its facilitative effect on the processing of words which are in the scope of syntactic or lexical focus marking. All three experiments tested German learners of English in a native German language condition and in English as their L2. Native English speakers were included as a control for the English language condition. Test materials consisted of single sentences, all dealing with bird life. Experiment 1 tested word recognition in three focus conditions (broad focus, narrow focus on the target, and narrow focus on a constituent than the target) in one condition using natural unmanipulated sentences, and in the other two conditions using spliced sentences. Experiment 2 (effect of syntactic focus marking) and Experiment 3 (effect of lexical focus marking) used phoneme monitoring as a measure for the speed of word processing. Additionally, a word recall test (4AFC) was conducted to assess the effective entry of target-bearing words in the listeners’ memory. Experiment 1: Focus marking by prosodic means Prosodic focus marking by pitch accent was found to highlight important information (Bolinger, 1972), making the accented word perceptually more prominent (Klatt, 1976; van Santen & Olive, 1990; Eefting, 1991; Koopmans-van Beinum & van Bergem, 1989). However, accent structure seems to be processed faster in native than in nonnative listening (Akker& Cutler, 2003, Expt. 3). Therefore, it is expected that prosodically marked words are better recognised than unmarked words, and that listeners can exploit accent structure better for accurate word recognition in their L1 than they do in the L2 (L1 > L2). Altogether, a difference in word recognition performance in L1 listening is expected between different focus conditions (narrow focus > broad focus). Results of Experiments 1 show that words were better recognized in native listening than in nonnative listening. Focal accent, however, doesn’t seem to help the German subjects recognize accented words more accurately, in both the L1 and the L2. This could be due to the focus conditions not being acoustically distinctive enough. Results of experiments with spliced materials suggest that the surrounding prosodic sentence contour made listeners remember a target word and not the local, prosodic realization of the word. Prosody seems to indeed direct listeners’ attention to the focus of the sentence (see Cutler, 1976). Regarding the salience of word position, VanPatten (2002; 2004) postulated a sentence location principle for L2 processing, stating a ranking of initial > final > medial word position. Other evidence mentions a processing adantage of items occurring late in the sentence (Akker & Cutler, 2003), and Rast (2003) observed in an English L2 production study a trend of an advantage of items occurring at the outer ends of the sentence. The current Experiment 1 aimed to keep the length of the sentences to an acceptable length, mainly to keep the task in the nonnative lnaguage condition feasable. Word length showed an effect only in combination with word position (Rast, 2003; Rast & Dommergues, 2003). Therefore, word length was included in the current experiment as a secondary factor and without hypotheses. Results of Experiment 1 revealed that the length of a word doesn’t seem to be important for its accurate recognition. Word position, specifically the final position, clearly seems to facilitate accurate word recognition in German. A similar trend emerges in condition English L2, confirming Klein (1984) and Slobin (1985). Results don’t support the sentence location principle of VanPatten (2002; 2004). The salience of the final position is interpreted as recency effect (Murdock, 1962). In addition, the advantage of the final position may benefit from the discourse convention that relevant background information is referred to first, and then what is novel later (Haviland & Clark, 1974). This structure is assumed to cue the listener as to what the speaker considers to be important information, and listeners might have reacted according to this convention. Experiment 2: Focus marking by syntactic means Atypical syntactic structures often draw listeners’ attention to certain information in an utterance, and the cleft structure as a focus marking device appears to be a common surface feature in many languages (Lambrecht, 2001). Surface structure influences sentence processing (Foss & Lynch, 1969; Langford & Holmes, 1979), which leads to competing hypotheses in Experiment 2: on the one hand, the focusing effect of the cleft construction might reduce processing times. On the other, cleft constructions in German were found to be used less to mark fo than in English (Ahlemeyer & Kohlhof, 1999; Doherty, 1999; E. Klein, 1988). The complexity of the constructions, and the experience from the native language might work against an advantage of the focus effect in the L2. Results of Experiment 2 show that the cleft structure is an effective device to mark focus in German L1. The processing advantage is explained by the low degree of structural markedness of cleft structures: listeners use the focus function of sentence types headed by the dummy subject es (English: it) due to reliance on 'safe' subject-prominent SVO-structures. The benefit of cleft is enhanced when the sentences are presented with context, suggesting a substantial benefit when focus effects of syntactic surface structure and coherence relation between sentences are integrated. Clefts facilitate word processing for English native speakers. Contrary to German L1, the marked cleft construction doesn’t reduce processing times in English L2. The L1-L2 difference was interpreted as a learner problem of applying specific linguistic structures according to the principles of information structure in the target language. Focus marking by cleft did not help German learners in native or in nonnative word recall. This could be attributed to the phonological similarity of the multiple choice options (Conrad & Hull, 1964), and to a long time span between listening and recall (Birch & Garnsey, 1995; McKoon et al., 1993). Experiment 3: Focus marking by lexical means Focus particles are elements of structure that can indicate focus (König, 1991), and their function is to emphasize a certain part of the sentence (Paterson et al., 1999). I argue that the focus particles even/only (German: sogar/nur) evoke contrast sets of alternatives resp. complements to the element in focus (Ni et al., 1996), which causes interpretations of context. Therefore, lexical focus marking isn’t expected to lead to faster word processing. However, since different mechanisms of encoding seem to underlie word memory, a benefit of the focusing function of particles is expected to show in the recall task: due to focus particles being a preferred and well-used feature for native speakers of German, a transfer of this habitualness is expected, resulting in a better recall of focused words. Results indicated that focus particles seem to be the weakest option to mark focus: Focus marking by lexical particle don’t seem to reduce word processing times in either German L1, English L2, or in English L1. The presence of focus particles is likely to instantiate a complex discourse model which lets the listener await further modifying information (Liversedge et al., 2002). This semantic complexity might slow down processing. There are no indications that focus particles facilitate native language word recall in German L1 and English L1. This could be because focus particles open sets of conditions and contexts that enlarge the set of representations in listeners rather than narrowing it down to the element in the scope of the focus particle. In word recall, the facilitative effect of focus particles emerges only in the nonnative language condition. It is suggested that L2 learners, when faced with more demanding tasks in an L2, use a broad variety of means that identify focus for a better representation of novel words in the memory. In Experiments 2 and 3, evidence suggests that accent is an important factor for efficient word processing and accurate recall in German L1 and English L1, but less so in English L2. This underlines the function of accent as core speech parameter and consistent cue to the perception of prominence native language use (see Cutler & Fodor, 1979; Pitt & Samuel, 1990a; Eriksson et al., 2002; Akker & Cutler, 2003); the L1-L2 difference is attributed to patterns of expectation that are employed in the L1 but not (yet?) in the L2. There seems to exist a fine-tuned sensitivity to how accents are distributed in the native language, listeners expect an appropriate distribution and interpret it accordingly (Eefting, 1991). This pleads for accent placement as extremely important to L2 proficiency; the current results also suggest that accent and its relationship with other speech parameters has to be newly established in the L2 to fully reveal its benefits for efficient processing of speech. There is evidence that additional context facilitates processing of complex syntactic structures but that a surplus of information has no effect if the sentence construction is less challenging for the listener. The increased amount of information to be processed seems to impede better word recall, particularly in the L2. Altogether, it seems that focus marking devices and context can combine to form an advantageous alliance: a substantial benefit in processing efficiency is found when parameters of focus marking and sentence coherence are integrated. L2 research advocates the beneficial aspects of providing context for efficient L2 word learning (Lawson & Hogben, 1996). The current thesis promotes the view that a context which offers more semantic, prosodic, or lexical connections might compensate for the additional processing load that context constitutes for the listeners. A methodological consideration concerns the order in which language conditions are presented to listeners, i.e., L1-L2 or L2-L1. Findings suggest that presentation order could enforce a learning bias, with the performance in the second experiment being influenced by knowledge acquired in the first (see Akker & Cutler, 2003). To conclude this work: The results of the present study suggest that information structure is more accessible in the native language than it is in the nonnative language. There is, however, some evidence that L2 learners have an understanding of the significance of some information-structural parameters of focus marking. This has a beneficial effect on processing efficiency and recall accuracy; on the cognitive side it illustrates the benefits and also the need of a dynamic exchange of information-structural organization between L1 and L2. The findings of the current thesis encourage the view that an understanding of information structure can help the learner to discover and categorise forms and meanings of the L2. Information structure thus emerges as a valuable resource to advance proficiency in a second language. N2 - Das Sprechen und Verstehen einer Fremdsprache (L2) stellt eine komplexe Leistung für einen Nicht-Muttersprachler dar. Kenntnisse und Fertigkeiten auf verschiedenen sprachlichen und außersprachlichen Ebenen wirken dabei zusammen, wie z.B. eine andere Grammatik, neue Lautbildungen in der Aussprache, der Aufbau von Wortschatz, und auch die Sensibilisierung für mögliche kulturell unterschiedliche Kommunikationsformen oder das Training kommunikativer Kompetenz. Eine wichtige Hilfe bei der muttersprachlichen wie der fremdsprachlichen Sprachverarbeitung bieten Mittel, mit denen sprachliche Information gegliedert wird, um sie verständlich zu machen. Die Informationsstruktur ermöglicht es, zum Beispiel den Fokus einer Äußerung zu markieren und damit Intentionen sprachlich zu vermitteln. In gesprochener Sprache sind es vor allem prosodische Mittel wie Satzakzent, die es dem Hörer ermöglichen, die wichtigen Informationen in der Äußerung herauszufinden. Aber auch durch die Verwendung unterschiedlicher grammatischer Strukturen oder durch besondere Wortwahl können Sprecher Satzteile markieren, die sie für besonders wichtig halten, und sie damit hervorheben. Wird die Informationsstruktur eines Satzes verletzt, indem zum Beispiel der Satzakzent auf ein eher unwichtiges Wort gelegt wird, kann der Gesprächspartner/die Gesprächspartnerin einen anderen Teil des Satzes als im Fokus stehend interpretieren als den vom Sprecher eigentlich intendierten Teil. Dies kann - in Kombination mit anderen Faktoren wie ungeschickter Wortwahl - zu Missverständnissen führen. Nun kann eine Sprache prosodische, syntaktische oder lexikalische Möglichkeiten der Markierung besitzen, die entweder in einer anderen Sprache nicht vorkommen, oder die andere Funktionen in Bezug auf die Interpretation von Äußerungen erfüllen, die in dieser Form in der jeweils anderen Sprache nicht existieren. Dies betrifft zum Beispiel Unterschiede zwischen Intonations- und Tonsprachen oder zwischen silbenzählenden und akzentzählenden Sprachen. Ruft der Fremdsprachenlerner die Strukturen sprachlicher Information in der Muttersprache (L1) ab und überträgt sie auf die Fremdsprache, kann dies bei gleicher informationsstruktureller Organisation der Sprache zu einer erfolgreichen Strategie des fremdsprachlichen Verstehens führen. Wird aber Informationsstruktur in der Fremdsprache mit anderen Mitteln als in der Muttersprache ausgedrückt, entsteht ein Spannungsfeld zwischen Verarbeitungsstrategien der Muttersprache und denen der Fremdsprache. Die vorliegende Arbeit befasst sich mit der Rolle informationsstruktureller Parameter in der muttersprachlichen und fremdsprachlichen Sprachverarbeitung. Es wird untersucht, wie Fremdsprachenlerner Fokusmarkierung in der Muttersprache (hier: Deutsch) und in der Fremdsprache (hier: Englisch) zu effizienter Sprachverarbeitung nutzen. Das Ziel ist eine tiefere Einsicht, wie sich Informationsstruktur in der Fremdsprache erschließt; die grundlegende Annahme ist dabei, dass ein Verständnis und eine Sensibilisierung für Informationsstruktur dem Fremdsprachenlerner hilft, Form und Bedeutung von Sprache zu erkennen. Eine solche Einsicht in Informationsstruktur unterstützt die Erweiterung und Festigung fremdsprachlicher Kompetenz. Die Frage nach dem Gebrauch von Informationsstruktur in einer Fremdsprache wird in drei experimentellen Studien untersucht, die sich auf jeweils eines der folgenden sprachlichen Mittel zur Fokusmarkierung konzentrieren: 1. Prosodische Mittel der Fokusmarkierung: Unterstützen Satzakzent und Wortposition im Satz eine bessere Worterkennung? 2. Syntaktische Mittel der Fokusmarkierung: Ermöglicht die Konstruktion eines Spaltsatzes (Englisch: cleft) eine schnellere Verarbeitung des fokussierten Elements im Satz als eine kanonische Wortstellung, und kann sich der Hörer auch zu einem späteren Zeitpunkt noch besser an ein syntaktisch markiertes als an ein unmarkiertes Element erinnern? 3. Lexikalische Mittel der Fokusmarkierung: Bewirken Fokuspartikel (hier: nur/sogar) eine schnellere Verarbeitung des fokussierten Elements, und kann sich der Hörer auch zu einem späteren Zeitpunkt noch besser an das fokussierte als an das nicht-fokussierte Element erinnern? Zusätzlich wird in Experiment 2 und in Experiment 3 untersucht, welchen Einfluss einleitende Fragen haben, die zur Fokusmarkierung eines Elements im Folgesatz dienen. Außerdem wird nachgegangen, welche Rolle es spielt, wenn ein syntaktisch oder lexikalisch fokussiertes Element einen Tonhöheakzent bekommt oder wenn dieser auf dem vorangegangenen Adjektiv realisiert wird. Die Probanden sind deutsche Muttersprachler, die Englisch als Fremdsprache gelernt haben. In den Experimenten werden den Testpersonen jeweils Sprachaufnahmen von deutschen Sätzen und Aufnahmen von parallel dazu konstruierten englischen Sätzen dargeboten. Als Kontrollgruppe für den englischen Teil der Experimente werden englische Muttersprachler getestet, um Referenzdaten für die Ergebnisse der Fremdsprachenlerner zu erhalten. Die Experimente sind als Perzeptionsexperimente konzipiert. Experiment 1 (prosodische Fokusmarkierung) untersucht Worterkennung in drei Bedingungen mitunterschiedlichem Fokus (weiter und enger Fokus, enger Fokus auf anderem Satzelement als dem Zielwort), und zwei Bedingungen mit künstlich durch splicing verändertem Sprachmaterial. In Experiment 2 (syntaktische Fokusmarkierung) und Experiment 3 (lexikalische Fokusmarkierung) wird im Hörexperiment als Methode phoneme monitoring angewandt, wobei die Reaktionszeiten zum Erkennen des fokussierten Worts (welches ein vorher spezifiziertes Phonem enthält) gemessen werden. Im Anschluss an den Hörteil wird in diesen zwei Experimenten außerdem ein Erinnerungstest durchgeführt, bei dem die fokussierten Elemente mit einem Multiple-Choice-Verfahren (4AFC) noch einmal abgefragt werden und die Anzahl der richtigen Antworten gewertet wird. Zu 1.: Prosodische Mittel der Fokusmarkierung Akzentuierung ist ein Mittel, um im Satz wichtige Information hervorzuheben (Bolinger, 1972), was zu einer besseren Wahrnehmung solch akzentuierter Information führt (siehe z.B. van Santen & Olive, 1990; Eefting, 1991). Akzentstruktur scheint jedoch schneller in der L1 als in der L2 verarbeitet zu werden (Akker & Cutler, 2003). Es wird daher angenommen, dass in der L1 eine Fokusmarkierung durch Tonhöheakzent zu besserer Worterkennung eines solchermaßen markierten Wortes führt. Akzentstruktur sollte sich auch in der L2 erschließen, wenn auch in geringerem Maß (L1 > L2). Insgesamt wird ein unterschiedlich starker Fokuseffekt je nach Fokusbedingung erwartet (enger Fokus > weiter Fokus). Die Ergebnisse von Experiment 1 bestätigen, dass Worte in der Muttersprache besser erkannt werden als in der Fremdsprache. Ein unterschiedlicher, als Satzakzent realisierter Fokus hilft allerdings den Probanden weder in der Muttersprache noch in der Fremdssprache, fokussierte Worte schneller zu erkennen. Dies könnte auf ungenügende akustische Unterschiede in der Realisierung der unterschiedlichen Fokuskonditionen in den Sprachaufnahmen zurückzuführen sein. Die Experimente mit synthetisch, durch splicing manipuliertem Sprachmaterial ergeben, dass die umgebende Satzprosodie eher zur Worterkennung beiträgt als die einzelne Akzentmarkierung des Wortes (Cutler, 1976). Für die Salienz der Wortposition im Satz postulierte VanPatten (2004) für fremdsprachliche Wahrnehmung die Reihenfolge von initialer > finaler > medialer Position. Akker und Cutler (2003) erwähnen für L1 und L2 einen Verarbeitungsvorteil von später im Satz auftretenden Worten gegenüber früher Auftretenden. Des weiteren fand Rast (2003) in einer L2-Produktionsstudie einen Vorteil der äußeren Satzpositionen gegenüber der medialen Position. Im vorliegenden Experiment werden die Sätze vor allem wegen der fremdsprachlichen Testbedingung in akzeptabler Länge gehalten, was Aussagen über die Position an den äußeren Satzenden ermöglicht, aber weniger deutliche Effekte für die medial Position erwarten lässt. Wortlänge wurde als Nebenfaktor mit in das Experiment aufgenommen ohne eigenständige Hypothesen dafür zu formulieren. In einer früheren L2 Studie zeigte Wortlänge nur in Abhängigkeit zur Position des Wortes im Satz einen Effekt (Rast, 2003; Rast & Dommergues, 2003). Die Ergebnisse von Experiment 1 zeigen, dass die Länge der Zielworte keine entscheidende Rolle für deren korrekte Erkennung spielt. Die Wortposition im Satz, und hier besonders die finale Position, trägt jedoch entscheidend zur korrekten Worterkennung im Deutschen bei. Ein ähnlicher Trend zeigt sich für die Worterkennung in der Fremdsprache Englisch (siehe Klein, 1984; Slobin, 1985). Das Lokalitätsprinzip von VanPatten (2004) mit dem Verarbeitungsvorteil von initial > final > medial kann nicht bestätigt werden, und die besondere Salienz der finalen Position wird mit Murdock (1962) als recency effect erklärt. Außerdem könnte die finale Position von der Konvention für die Integration neuer Information profitieren: bekannte Information wird vor neuer Information genannt (Haviland & Clark, 1974). Hörer handeln nach dieser üblichen Diskursstruktur und richten ihre Aufmerksamkeit auf Information, die in finaler Position genannt wird. Zu 2.: Syntaktische Mittel der Fokusmarkierung Die Abweichung von kanonischer Satzstruktur lenkt die Aufmerksamkeit auf bestimmte Elemente im Satz, und der Spaltsatz ist in vielen Sprachen eine bekannte Art der Fokussierung (Lambrecht, 2001). Die Oberflächenstruktur eines Satzes beeinflusst seine Verarbeitung (Foss & Lynch, 1969; Langford & Holmes, 1979) und in Experiment 2 stehen zwei Hypothesen gegenüber: Der fokussierende Effekt von Spaltsätzen könnte einen Verarbeitungsvorteil bewirken. Andererseits sind Spaltsätze im Deutschen seltener und weniger gebräuchlich als im Englischen (Ahlemeyer & Kohlhof, 1999; Doherty, 1999; E. Klein, 1988); die syntaktische Komplexität von Spaltsätzen und die Erfahrung der Muttersprache könnten einem Verarbeitungsvorteil in Deutsch L1 und Englisch L2 entgegenwirken. Die Ergebnisse von Experiment 2 zeigen, dass der Spaltsatz ein effektives Mittel der Fokusmarkierung im Deutschen ist. Dies wird auf die geringe strukturelle Markiertheit des Ersatz-Subjekts ‚es’ zurückgeführt, da es an kanonischer, initialer Stelle steht. Die Prominenz dieses Subjekts setzt das nachfolgende Subjekt-Element in Fokus und verleiht ihm Subjekt-Prominenz. Der verarbeitungsfördernde Effekt von Spaltsätzen wird noch erhöht, wenn Oberflächenstruktur (Spaltsatz) und Satzzusammenhang (Kontext) integriert werden. Der Spaltsatz wird jedoch nicht in der Fremdsprache als ein effektives Mittel der Fokusmarkierung genutzt. Englische Muttersprachler nutzen den Fokuseffekt des Spaltsatzes zur schnellen Worterkennung, aber dieses informationsstrukturelle Mittel der L2 wird nicht von Fremdsprachenlernern erkannt und verwertet. Dies wird als Lernerproblem interpretiert: linguistische Strukturen der Muttersprache werden nicht adäquat nach informationsstrukturellen Prinzipien in der Fremdsprache angewandt. Der Spaltsatz trägt weder im Deutschen noch im Englischen zu einer besseren Erinnerungsleistung bei. Das kann zum einen an der starken phonologischen Ähnlichkeit der im Test angebotenen Antwortoptionen liegen (Conrad & Hull, 1964); zum anderen kann es mit der Zeitspanne zusammenhängen, die zwischen Hörexperiment und Erinnerungstest liegen und die die Erinnerung an ein bestimmtes Wort zu sehr erschwert (Birch & Garnsey, 1995; McCoon et.al., 1993). Zu 3.: Lexikalische Mittel der Fokusmarkierung Fokuspartikel sind Exponenten von Fokusstruktur und sie markieren Satzelemente (König, 1991; Paterson et al., 1999). Die untersuchten Fokuspartikel evozieren Kontrast und Alternativmengen zu dem fokussierten Element, was Interpretationen von Kontext bewirkt (Ni et al., 1996; Liversedge et al., 2002). Von daher wird keine schnellere Verarbeitung von fokussierten Worten erwartet. Ihre förderliche Eigenschaft zeigt sich jedoch in der Erinnerungsleistung, da sich dieser Prozess auf andere Erschließungsmechanismen zu stützen scheint: es wird erwartet, dass der bevorzugte Gebrauch von lexikalischen Mitteln zur Fokusmarkierung im Deutschen (König, 1991; Ahlemeyer & Kohlhof, 1999) sich positiv auf die Erinnerung von fokussierten Worten auswirkt. Die Fokuspartikel nur und sogar in Experiment 3 erweisen sich in der Experimentreihe als schwächste Exponenten von Fokusmarkierung: Weder im Deutschen noch in Englischen als Fremdsprache noch in der englischen Kontrollgruppe bewirken diese Fokuspartikel eine schnellere Verarbeitung des fokussierten Elements. Dies erklärt sich durch die Eigenschaft von Fokuspartikeln, eine Menge an Alternativen zu evozieren und dadurch beim Hörer komplexe Diskursmodelle anzuregen, die sowohl das Element in Fokus als auch Alternativen dazu beinhalten (siehe Ni et al., 1996; Liversedge et al., 2002). Verarbeitung und Interpretation der Fokusstruktur benötigen dann einen erhöhten Zeitaufwand. Im Erinnerungstest kommt der Fokuseffekt nur in der fremdsprachlichen Testbedingung zum Tragen: Werden Lerner hinsichtlich mit hinsichtlich ihrer L2-Fertigkeit anspruchsvollen Situationen konfrontiert, wird Fokusstruktur zu einer besseren Repräsentation in der Erinnerung genutzt. Übergreifend zeigt sich aus Experiment 2 und Experiment 3, dass ein zusätzlicher Satzakzent in Sätzen mit syntaktischer oder lexikalischer Fokusmarkierung in muttersprachlichem Deutsch und Englisch genutzt wird, aber in der Fremdsprache nicht gleichermaßen effektiv verarbeitet wird. Ein bedeutender Parameter wie Tonhöheakzent wird in der Fremdsprache scheinbar weniger genutzt, wenn gleichzeitig andere Mittel der Markierung auftreten. Vor allem deutet dieser Effekt jedoch auf eine weitaus differenziertere Wahrnehmung und Interpretation von Tonhöheakzent in der Muttersprache hin. Des weiteren scheint die Reihenfolge, in der die Testsprachen den Probanden angeboten werden (L1-L2,oder L2-L1) von Bedeutung zu sein, da ein Lerneffekt aus der ersten Testsprache die Leistung in der zweiten Testsprache beeinflussen kann. Dies erschwert die Erhebung vergleichbarer Daten für zwei Sprachen von derselben Probandengruppe (siehe Akker & Cutler, 2003). Im Hinblick auf die Auswirkungen von Kontext auf die Wortverarbeitung weisen die Ergebnisse darauf hin, dass vorangestellte Fragen dem Fremdsprachenlerner nur bedingt Hilfe bei der zügigen Verarbeitung von z.B. schwierigeren Satzkonstruktionen bieten. Zusätzlicher Kontext scheint außerdem die Erinnerungsleistung zu erschweren, vor allem in der Fremdsprache. Sowohl in der Fremdsprachenforschung als auch in der Fremdsprachendidaktik hat die Einbettung in einen Kontext bei dem Erlernen von Worten eine große Bedeutung (Lawson & Hogben, 1996). Es wird dahingehend argumentiert, dass eine Form von Kontext, die mehr semantische, prosodische oder lexikalische Verbindungen schafft, den zusätzlichen Verarbeitungsaufwand kompensieren müsste. Die Ergebnisse der vorliegenden Arbeit weisen darauf hin, dass sich Informationsstruktur eher in der Muttersprache als in der Fremdsprache erschließt. Einzelne informationsstrukturelle Parameter werden jedoch sehr wohl von den Fremdsprachenlernern erfolgreich ausgewertet, was sich in einer schnelleren und nachhaltigeren sprachlichen Verarbeitung äußert. Auf der kognitiven Ebene zeigt die vorliegende Arbeit die vorteilhafte Wirkung auf, wenn Informationsstruktur von Mutter- und Fremdsprache in dynamischem Austausch stehen. Die Ergebnisse bestärken die Annahme, dass ein Verständnis von Informationsstruktur dem Fremdsprachenlerner helfen kann, Form und Bedeutung der Fremdsprache zu erkennen. Informationsstruktur erweist sich als potentiell wertvolle Ressource in der Entwicklung und Stärkung fremdsprachlicher Kompetenz. KW - Informationsstruktur KW - fremdsprachliche Worterkennung KW - Sprachverarbeitung KW - Fokus KW - Fremdsprachenerwerb KW - information structure KW - L2 word recognition KW - L2 processing KW - focus KW - L2 acquisition Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-37237 ER - TY - BOOK A1 - Iro, Andrea T1 - The UN Peacebuilding Commission : lessons from Sierra Leone N2 - “The UN Peacebuilding Commission – Lessons from Sierra Leone” by political scientist Andrea Iro is an assessment of the United Nations Peacebuilding Commission (PBC) and the United Nations Peacebuilding Fund (PBF) by analysing their performance over the last two years in Sierra Leone, one of the first PBC focus countries. The paper explores the key question of how the PBC/PBF’s mandate has been translated into operational practice in the field. It concludes that though the overall impact has been mainly positive and welcomed by the country, translating the general mandate into concrete activities remains a real challenge at the country level. T3 - WeltTrends Thesis - 6 KW - Vereinte Nationen KW - Sierra Leone KW - Friedensforschung KW - United Nations KW - Sierra Leone KW - Peace Studies Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29599 SN - 978-3-940793-77-5 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Hejazi, Mahdi A1 - Fettke, Jörg A1 - Paris, Oskar A1 - Steup, Martin T1 - The two plastidial starch-related dikinases sequentially phosphorylate glucosyl residues at the surface of both the a- and b-type allomorphs of crystallized maltodextrins but the mode of action differs N2 - In this study, two crystallized maltodextrins were generated that consist of the same oligoglucan pattern but differ strikingly in the physical order of double helices. As revealed by x-ray diffraction, they represent the highly ordered A- and B-type allomorphs. Both crystallized maltodextrins were similar in size distribution and birefringence. They were used as model substrates to study the consecutive action of the two starch-related dikinases, the glucan, water dikinase and the phosphoglucan, water dikinase. The glucan, water dikinase and the phosphoglucan, water dikinase selectively esterify glucosyl residues in the C6 and C3 positions, respectively. Recombinant glucan, water dikinase phosphorylated both allomorphs with similar rates and caused complete glucan solubilization. Soluble neutral maltodextrins inhibited the glucan, water dikinase-mediated phosphorylation of crystalline particles. Recombinant phosphoglucan, water dikinase phosphorylated both the A- and B-type allomorphs only following a prephosphorylation by the glucan, water dikinase, and the activity increased with the extent of prephosphorylation. The action of the phosphoglucan, water dikinase on the prephosphorylated A- and B-type allomorphs differed. When acting on the B-type allomorph, by far more phosphoglucans were solubilized as compared with the A type. However, with both allomorphs, the phosphoglucan, water dikinase formed significant amounts of mono-phosphorylated phosphoglucans. Thus, the enzyme is capable of acting on neutral maltodextrins. It is concluded that the actual carbohydrate substrate of the phosphoglucan, water dikinase is defined by physical rather than by chemical parameters. A model is proposed that explains, at the molecular level, the consecutive action of the two starch-related dikinases. Y1 - 2009 UR - http://www.plantphysiol.org/ U6 - https://doi.org/10.1104/pp.109.138750 SN - 0032-0889 ER - TY - JOUR A1 - Bardi, Anat A1 - Lee, Julie Anne A1 - Hofmann-Towfigh, Nadi A1 - Soutar, Geoffrey T1 - The structure of intraindividual value change N2 - Values are assumed to be relatively stable during adulthood. Yet, little research has examined value stability and change, and there are no studies on the structure of value change. On the basis of S. H. Schwartz's (1992) value theory, the authors propose that the structure of intraindividual value change mirrors the circumplexlike structure of values so that conflicting values change in opposite directions and compatible values change in the same direction. Four longitudinal studies, varying in life contexts, time gaps, populations, countries, languages, and value measures, supported the proposed structure of intraindividual value change. An increase in the importance of any one value is accompanied by slight increases in the importance of compatible values and by decreases in the importance of conflicting values. Thus, intraindividual changes in values are not chaotic, but occur in a way that maintains Schwartz's value structure. Furthermore, the greater the extent of life-changing events, the greater the value change found, whereas age was only a marginal negative predictor of value change when life events were taken into account. Implications for the structure of personality change are discussed. Y1 - 2009 UR - http://www.apa.org/pubs/journals/psp/index.aspx U6 - https://doi.org/10.1037/A0016617 SN - 0022-3514 ER - TY - JOUR A1 - Schorck, Torben A1 - Christlieb, Norbert A1 - Cohen, Judy G. A1 - Beers, Timothy C. A1 - Shectman, Steve A1 - Thompson, Ian A1 - McWilliam, Andrew A1 - Bessell, Michael S. A1 - Norris, John E. A1 - Meléndez, Jorge A1 - Ramïrez, Solange A1 - Haynes, D. A1 - Cass, Paul A1 - Hartley, Malcolm A1 - Russell, Ken A1 - Watson, Fred A1 - Zickgraf, Franz-Josef A1 - Behnke, Berit A1 - Fechner, Cora A1 - Fuhrmeister, Birgit A1 - Barklem, Paul S. A1 - Edvardsson, Bengt A1 - Frebel, Anna A1 - Wisotzki, Lutz A1 - Reimers, Dieter T1 - The stellar content of the Hamburg/ESO survey : V. the metallicity distribution function of the Galactic halo N2 - We determine the metallicity distribution function (MDF) of the Galactic halo by means of a sample of 1638 metal-poor stars selected from the Hamburg/ESO objective-prism survey (HES). The sample was corrected for minor biases introduced by the strategy for spectroscopic follow-up observations of the metal-poor candidates, namely "best and brightest stars first". Comparison of the metallicities [Fe/H] of the stars determined from moderate-resolution (i.e., R similar to 2000) follow-up spectra with results derived from abundance analyses based on high-resolution spectra (i.e., R > 20 000) shows that the [Fe/H] estimates used for the determination of the halo MDF are accurate to within 0.3 dex, once highly C-rich stars are eliminated. We determined the selection function of the HES, which must be taken into account for a proper comparison between the HES MDF with MDFs of other stellar populations or those predicted by models of Galactic chemical evolution. The latter show a reasonable agreement with the overall shape of the HES MDF for [Fe/H] > -3.6, but only a model of Salvadori et al. (2007) with a critical metallicity for low-mass star formation of Z(cr) = 10(-3.4) Z(circle dot) reproduces the sharp drop at [Fe/H] similar to -3.6 present in the HES MDF. Although currently about ten stars at [Fe/H] < -3.6 are known, the evidence for the existence of a tail of the halo MDF extending to [Fe/H] similar to -5.5 is weak from the sample considered in this paper, because it only includes two stars [Fe/H] < -3.6. Therefore, a comparison with theoretical models has to await larger statistically complete and unbiased samples. A comparison of the MDF of Galactic globular clusters and of dSph satellites to the Galaxy shows qualitative agreement with the halo MDF, derived from the HES, once the selection function of the latter is included. However, statistical tests show that the differences between these are still highly significant. Y1 - 2009 UR - http://www.aanda.org/ U6 - https://doi.org/10.1051/0004-6361/200810925 SN - 0004-6361 ER - TY - JOUR A1 - Hoke, Gregory D. A1 - Garzione, Carmala N. A1 - Araneo, Diego C. A1 - Latorre, Claudio A1 - Strecker, Manfred A1 - Williams, Kendra J. T1 - The stable isotope altimeter : do quaternary pedogenic carbonates predict modern elevations? N2 - Stable isotope altimetry is a useful tool for estimating paleoelevation in sedimentary records. Yet questions remain regarding how source moisture, climate, and local topography can influence these estimates. Here we present stable isotope altimetry results on late Quaternary pedogenic carbonates of known elevation on both flanks of the Andean orogen at 33 degrees S. We measured delta O-18 values of pedogenic carbonates and river water samples from small drainages at regular elevation increments within the Rio Aconcagua (Chile) and Rio Mendoza (Argentina) catchments. The delta O-18 values of river waters correlate well with elevation and show similar isotopic gradients between the Chilean (-3.7 parts per thousand/km) and Argentine (-4.8 parts per thousand/km) sides of the range. Uncertainties associated with scatter in the river water data and assumptions about the temperature of carbonate formation indicate that elevation estimates have 1 sigma errors of 350-450 m. We estimate the isotopic composition of soil water from pedogenic carbonates on both sides of the range by assuming mean annual temperatures based the modern temperature lapse rate from meteorological station data. Combined, our data show that stable isotope altimetry produces reasonable estimates of modern elevation, with the majority of our samples (60%) within the 1 sigma uncertainties and 77% within 2 sigma. Y1 - 2009 UR - http://geology.gsapubs.org/ U6 - https://doi.org/10.1130/G30308a.1 SN - 0091-7613 ER - TY - JOUR A1 - Naso, Alessia A1 - Dreyer, Ingo A1 - Pedemonte, Laura A1 - Testa, Ilaria A1 - Gomez-Porras, Judith Lucia A1 - Usai, Cesare A1 - Müller-Röber, Bernd A1 - Diaspro, Alberto A1 - Gambale, Franco A1 - Picco, Cristiana T1 - The role of the C-terminus for functional heteromerization of the plant channel KDC1 N2 - Voltage-gated potassium channels are formed by the assembly of four identical (homotetramer) or different (heterotetramer) subunits. Tetramerization of plant potassium channels involves the C-terminus of the protein. We investigated the role of the C-terminus of KDC1, a Shaker-like inward-rectifying K+ channel that does not form functional homomeric channels, but participates in the formation of heteromeric complexes with other potassium alpha- subunits when expressed in Xenopus oocytes. The interaction of KDC1 with KAT1 was investigated using the yeast two- hybrid system, fluorescence and electrophysiological studies. We found that the KDC1-EGFP fusion protein is not targeted to the plasma membrane of Xenopus oocytes unless it is coexpressed with KAT1. Deletion mutants revealed that the KDC1 C- terminus is involved in heteromerization. Two domains of the C-terminus, the region downstream the putative cyclic nucleotide binding domain and the distal part of the C-terminus called K-HA domain, contributed to a different extent to channel assembly. Whereas the first interacting region of the C-terminus was necessary for channel heteromerization, the removal of the distal KHA domain decreased but did not abolish the formation of heteromeric complexes. Similar results were obtained when coexpressing KDC1 with the KAT1-homolog KDC2 from carrots, thus indicating the physiological significance of the KAT1/KDC1 characterization. Electrophysiological experiments showed furthermore that the heteromerization capacity of KDC1 was negatively influenced by the presence of the enhanced green fluorescence protein fusion. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00063495 U6 - https://doi.org/10.1016/j.bpj.2009.02.055 SN - 0006-3495 ER - TY - THES A1 - Cruz Centeno, Danilo da T1 - The role of malate in the development of tomato fruit Y1 - 2009 CY - Potsdam ER - TY - JOUR A1 - Mora, Andrés A1 - Gaona, Tatiana A1 - Kley, Jonas A1 - Montoya, Diana A1 - Parra, Mauricio A1 - Quiroz, Luis Ignacio A1 - Reyes, German A1 - Strecker, Manfred T1 - The role of inherited extensional fault segmentation and linkage in contractional orogenesis : a reconstruction of Lower Cretaceous inverted rift basins in the Eastern Cordillera of Colombia N2 - Lower Cretaceous early syn-rift facies along the eastern flank of the Eastern Cordillera of Colombia, their provenance, and structural context, reveal the complex interactions between Cretaceous extension, spatio-temporal trends in associated sedimentation, and subsequent inversion of the Cretaceous Guatiquia paleo-rift. South of 4 degrees 30'N lat, early syn-rift alluvial sequences in former extensional footwall areas were contemporaneous with fan- delta deposits in shallow marine environments in adjacent hanging-wall areas. In general, footwall erosion was more pronounced in the southern part of the paleorift. In contrast, early syn-rift sequences in former footwall areas in the northern rift sectors mainly comprise shallow marine supratidal sabkha to intertidal strata, whereas hanging-wall units display rapid transitions to open-sea shales. In comparison with the southern paleo-rift sector, fan-delta deposits in the north are scarce, and provenance suggests negligible footwall erosion. The southern graben segment had longer, and less numerous normal faults, whereas the northern graben segment was characterized by shorter, rectilinear faults. To the east, the graben system was bounded by major basin-margin faults with protracted activity and greater throw as compared with intrabasinal faults to the west. Intrabasinal structures grew through segment linkage and probably interacted kinematically with basin-margin faults. Basin-margin faults constitute a coherent fault system that was conditioned by pre-existing basement fabrics. Structural mapping, analysis of present-day topography, and balanced cross sections indicate that positive inversion of extensional structures was focused along basin-bounding faults, whereas intrabasinal faults remained unaffected and were passively transported by motion along the basin-bounding faults. Thus, zones of maximum subsidence in extension accommodated maximum elevation in contraction, and former topographic highs remained as elevated areas. This documents the role of basin-bounding faults as multiphased, long-lived features conditioned by basement discontinuities. Inversion of basin-bounding faults was more efficient in the southern than in the northern graben segment, possibly documenting the inheritance and pivotal role of fault-displacement gradients. Our observations highlight similarities between inversion features in orogenic belts and intra-plate basins, emphasizing the importance of the observed phenomena as predictive tools in the spatiotemporal analysis of inversion histories in orogens, as well as in hydrocarbon and mineral deposits exploration. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0950-091X U6 - https://doi.org/10.1111/j.1365-2117.2008.00367.x SN - 0950-091X ER - TY - JOUR A1 - Florence, Gerson A1 - Dahlem, Markus A. A1 - Almeida, Antônio-Carlos G. A1 - Bassani, José W. M. A1 - Kurths, Jürgen T1 - The role of extracellular potassium dynamics in the different stages of ictal bursting and spreading depression : a computational study N2 - Experimental evidences point Out the participation of nonsynaptic mechanisms (e.g., fluctuations in extracellular tons) in epileptiform bursting and spreading depression (SD). During these abnormal oscillatory patterns, it is observed an increase of extracellular potassium concentration [K+](o) and a decrease of extracellular calcium concentration [Ca2+](o) which raises the neuronal excitability. However, whether the high [K+](o) triggers and propagates these abnormal neuronal activities or plays a secondary role into this process is unclear. To better understand the influence of extracellular potassium dynamics in these oscillatory patterns, the experimental conditions of high [K+](o) and zero [Ca2+](o) were replicated in an extended Golomb model where we added important regulatory mechanisms of ion concentration as Na+-K+ pump, ion diffusion and glial buffering. Within these Conditions, simulations of the cell model exhibit seizure-like discharges (ictal bursting). The SD was elicited by the interruption of the Na+- K+ pump activity, mimicking the effect of cellular hypoxia (an experimental protocol to elicit SD, the hypoxia-induced SD). We used the bifurcation theory and the fast-slow method to analyze the interference of K+ dynamics in the cellular excitability. This analysis indicates that the system loses its stability at a high [K+](o), transiting to an elevated state of neuronal excitability. Effects of high [K+](o), are observed in different stages of ictal bursting and SD. In the initial stage, the increase of [K+](o) creates favorable conditions to trigger both oscillatory patterns. During the neuronal activity, a continuous growth of [K+](o) by outward K+ flow depresses K+ Currents in a positive feedback way. At the last stage, due to the depression of K+ currents, the Na+-K+ pump is the main mechanism in the end of neuronal activity. Thus, this work suggests that [K+](o) dynamics may play a fundamental role in these abnormal oscillatory patterns. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00225193 U6 - https://doi.org/10.1016/j.jtbi.2009.01.032 SN - 0022-5193 ER - TY - JOUR A1 - Wolf, Hans-Georg A1 - Igboanusi, Herbert T1 - The role of ethnically mixed marriages in language shift : a case study of Nigeria's minority languages N2 - As the foundation of homes, the marriage institution is an important agent of sociali- zation. In this regard, marriage can be relied upon as a major factor in language and cultural maintenance. However, mixed marriages may contribute to language shift in the home because they can lead to a change in language use patterns among minority language speakers and their children. This means that the likelihood of preserving a minority language is greater in marriages among individuals who speak the same indigenous language than in situations in which spouses speak different languages. This study uses questionnaire data from parents of ethnically mixed marriages to explain how mixed marriages contribute to language shift from minority languages to English (Nigeria's official language), Nigerian Pidgin (informal lingua franca) and the major languages (i.e. Hausa, Igbo and Yoruba) in the home domains. The study shows that the future of minority languages will largely depend on the roles of families and the value attached to minority ethnic identity by young people, particularly those from mixed homes. Keywords: language shift; maintenance; family; minority languages; intermarriage; nigeria Y1 - 2009 ER - TY - JOUR A1 - Schröder, Christoph A1 - Menz, Astrid T1 - The reviewer punishes the messenger : a reply to Mark Kirchner's review of Tüerkiye'de dil tartismalari Y1 - 2009 SN - 1431-4983 ER -