TY - JOUR A1 - Bestenlehner, J. M. T1 - Stellar parameters from photometric data for fainter and more distant Wolf-Rayet stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Spectroscopy is the preferred way to study the physical and wind properties of Wolf-Rayet (WR) stars, but with decreasing brightness and increasing distance of the object spectroscopy become very expensive. However, photometry still delivers a high signal to noise ratio. Current and past astronomical surveys and space missions provide large data sets, that can be harvested to discover new WR stars and study them over a wide metallicity range with the help of state of the art stellar atmosphere and evolutionary models. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88390 SP - 354 ER - TY - JOUR A1 - Bethge, Joseph A1 - Serth, Sebastian A1 - Staubitz, Thomas A1 - Wuttke, Tobias A1 - Nordemann, Oliver A1 - Das, Partha-Pratim A1 - Meinel, Christoph T1 - TransPipe BT - A Pipeline for Automated Transcription and Translation of Videos JF - EMOOCs 2021 N2 - Online learning environments, such as Massive Open Online Courses (MOOCs), often rely on videos as a major component to convey knowledge. However, these videos exclude potential participants who do not understand the lecturer’s language, regardless of whether that is due to language unfamiliarity or aural handicaps. Subtitles and/or interactive transcripts solve this issue, ease navigation based on the content, and enable indexing and retrieval by search engines. Although there are several automated speech-to-text converters and translation tools, their quality varies and the process of integrating them can be quite tedious. Thus, in practice, many videos on MOOC platforms only receive subtitles after the course is already finished (if at all) due to a lack of resources. This work describes an approach to tackle this issue by providing a dedicated tool, which is closing this gap between MOOC platforms and transcription and translation tools and offering a simple workflow that can easily be handled by users with a less technical background. The proposed method is designed and evaluated by qualitative interviews with three major MOOC providers. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516943 VL - 2021 SP - 79 EP - 94 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Betz, Hariolf A1 - Raiser, Frank A1 - Frühwirth, Thom T1 - Persistent constraints in constraint handling rules N2 - In the most abstract definition of its operational semantics, the declarative and concurrent programming language CHR is trivially non-terminating for a significant class of programs. Common refinements of this definition, in closing the gap to real-world implementations, compromise on declarativity and/or concurrency. Building on recent work and the notion of persistent constraints, we introduce an operational semantics avoiding trivial non-termination without compromising on its essential features. Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41547 ER - TY - CHAP A1 - Beyssade, Claire A1 - Marandin, Jean-Marie T1 - From complex to simple speech acts : a bidimensional analysis of illocutionary N2 - We present a new analysis of illocutionary forces in dialogue. We analyze them as complex conversational moves involving two dimensions: what Speaker commits herself to and what she calls on Addressee to perform. We start from the analysis of speech acts such as confirmation requests or whimperatives, and extend the analysis to seemingly simple speech acts, such as statements and queries. Then, we show how to integrate our proposal in the framework of the Grammar for Conversation (Ginzburg, to app.), which is adequate for modelling agents' information states and how they get updated. Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10319 ER - TY - JOUR A1 - Bibby, J. A1 - Shara, M. A1 - Zurek, D. A1 - Crowther, P. A. A1 - Moffat, Anthony F. J. A1 - Drissen, L. A1 - Wilde, M. T1 - The Distribution of Massive Stars in M101 JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 75 WR stars and 164 RSGs are identified in a single WFC3 pointing of our M101 survey. We find that within it's large star-forming complex NGC 5462 WR stars are preferentially located in the core whilst RSGs are found in the halo, suggesting two bursts of star-formation. A review of our WR candidates reveals that only ∼30% are detected in the archival broad-band ACS imaging whilst only ∼50% are associated with HII regions. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88402 SP - 355 ER - TY - GEN A1 - Biddle, M. B. A1 - Rickert, S. E. A1 - Lando, J. B. A1 - Laschewsky, André T1 - The use of the Langmuir-Blodgett technique to obtain ultra-thin polar films N2 - The piezoelectric and pyroelectric properties of oriented films possessing dipole moments are increasingly being used in pressure, acoustic, thermal and optical devices. The performance of these devices in many applications may be enhanced by thin-film technology.The developing Langmuir-Blodgett thin-film deposition technique offers the opportunity to obtain highly oriented and uniform organic-based films in the 10–5000 nm thickness range. Special techniques must be used, however, to assemble these molecules in such a way as to result in polar multilayer films. Several possible deposition techniques are investigated, with one resulting in a polar and pyroelectric film about 50 nm thick. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 098 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17185 ER - TY - GEN A1 - Bielawski, Martina A1 - Jurišić, J. A1 - Lenz, T. A1 - Maxian Rusche, T. A1 - Nippert, C. T1 - Via : communis Europa ; Europe's architecture in 2020 N2 - Forum: EU-Diplomatie im Jahre 2020 KW - Europäische Union KW - Europaidentität KW - Außenpolitik KW - Verteidigungspolitik KW - European Union KW - European identity KW - foreign policy KW - defence policy Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48454 ER - TY - GEN A1 - Billard, Isabelle A1 - Ansoborlo, Eric A1 - Apperson, Kathleen A1 - Arpigny, Sylvie A1 - Azenha, M. Emilia A1 - Birch, David A1 - Bros, Pascal A1 - Burrows, Hugh D. A1 - Choppin, Gregory A1 - Kumke, Michael Uwe T1 - Aqueous solutions of Uranium(VI) as studied by time-resolved emission spectroscopy : a Round-Robin Test N2 - Results of an inter-laboratory round-robin study of the application of time-resolved emission spectroscopy (TRES) to the speciation of uranium(VI) in aqueous media are presented. The round-robin study involved 13 independent laboratories, using various instrumentation and data analysis methods. Samples were prepared based on appropriate speciation diagrams and, in general, were found to be chemically stable for at least six months. Four different types of aqueous uranyl solutions were studied: (1) acidic medium where UO22+aq is the single emitting species, (2) uranyl in the presence of fluoride ions, (3) uranyl in the presence of sulfate ions, and (4) uranyl in aqueous solutions at different pH, promoting the formation of hydrolyzed species. Results between the laboratories are compared in terms of the number of decay components, luminescence lifetimes, and spectral band positions. The successes and limitations of TRES in uranyl analysis and speciation in aqueous solutions are discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 005 KW - uranium (VI) KW - intercomparison KW - speciation Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12318 ER - TY - JOUR A1 - Bièvre-Perrin, Fabien ED - Bièvre-Perrin, Fabien ED - Carlà-Uhink, Filippo ED - Rollinger, Christian ED - Walde, Christine T1 - “Everything is a copy of a copy of a copy” BT - Preface JF - thersites 13: Antiquipop – Chefs d’œuvres revisités N2 - A quote from Fight Club (Chuck Palahniuk, 1996) may seem unusual for a Classicist. Nevertheless, this famous sentence summarises the contents of this special issue of thersites perfectly. As specialists in classical reception frequently witness, there is a sort of déjà-vu effect when it comes to the presence of Antiquity within popular culture. In 2019, to try to better understand the phenomenon, Antiquipop invited researchers to take an interest in the construction and semantic path of these “masterpieces” in contemporary popular culture, with a particular focus on the 21st century. Y1 - 2021 U6 - https://doi.org/10.34679/thersites.vol13.191 SN - 2364-7612 VL - 2021 IS - 13 SP - i EP - v ER - TY - JOUR A1 - Blackwell, Virginia Katherine A1 - Wiltrout, Mary Ellen T1 - Learning During COVID-19 BT - Engagement and Attainment in an Introductory Biology MOOC JF - EMOOCs 2021 N2 - During the COVID-19 pandemic, learning in higher education and beyond shifted en masse to online formats, with the short- and long-term consequences for Massive Open Online Course (MOOC) platforms, learners, and creators still under evaluation. In this paper, we sought to determine whether the COVID-19 pandemic and this shift to online learning led to increased learner engagement and attainment in a single introductory biology MOOC through evaluating enrollment, proportional and individual engagement, and verification and performance data. As this MOOC regularly operates each year, we compared these data collected from two course runs during the pandemic to three pre-pandemic runs. During the first pandemic run, the number and rate of learners enrolling in the course doubled when compared to prior runs, while the second pandemic run indicated a gradual return to pre-pandemic enrollment. Due to higher enrollment, more learners viewed videos, attempted problems, and posted to the discussion forums during the pandemic. Participants engaged with forums in higher proportions in both pandemic runs, but the proportion of participants who viewed videos decreased in the second pandemic run relative to the prior runs. A higher percentage of learners chose to pursue a certificate via the verified track in each pandemic run, though a smaller proportion earned certification in the second pandemic run. During the pandemic, more enrolled learners did not necessarily correlate to greater engagement by all metrics. While verified-track learner performance varied widely during each run, the effects of the pandemic were not uniform for learners, much like in other aspects of life. As such, individual engagement trends in the first pandemic run largely resemble pre-pandemic metrics but with more learners overall, while engagement trends in the second pandemic run are less like pre-pandemic metrics, hinting at learner “fatigue”. This study serves to highlight the life-long learning opportunity that MOOCs offer is even more critical when traditional education modes are disrupted and more people are at home or unemployed. This work indicates that this boom in MOOC participation may not remain at a high level for the longer term in any one course, but overall, the number of MOOCs, programs, and learners continues to grow. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-517251 SN - 978-3-86956-512-5 VL - 2021 SP - 219 EP - 236 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Blahušiaková, Andrea A1 - Röper-Kühnemann, Christian A1 - Staufenbiel, Christoph A1 - Vozárová, Hana T1 - Relating to students JF - Potsdamer geographische Praxis N2 - 1. The Assignment 'Devotion to Religion and acitive Citizenship' 2. The Assignment 'How are religious spread across Europe' 3. The Assignment 'Is football as important as religion?' 4. The Assignment 'Why be religious?' 5. The Assignment 'Lucky charms' 6. The Assignment 'No Creo en el Jamas' (Life after death) 7. The Assignment 'Religion and its influence on politics ans policies' 8. The Assignment 'Secularisation in Europe' 9. The Assignment 'The meaning of religious places' 10. The Assignment 'Unity in diversity' 11. Which conceptions did you find? KW - Europäische Werteerziehung KW - Familie KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - Family KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-65769 SN - 2194-1599 SN - 2194-1602 IS - 1 SP - 25 EP - 31 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Blanc, Olivier A1 - Constant, Matthieu A1 - Watrin, Patrick T1 - Segmentation in super-chunks with a finite-state approach N2 - Since Harris’ parser in the late 50s, multiword units have been progressively integrated in parsers. Nevertheless, in the most part, they are still restricted to compound words, that are more stable and less numerous. Actually, language is full of semi-fixed expressions that also form basic semantic units: semi-fixed adverbial expressions (e.g. time), collocations. Like compounds, the identification of these structures limits the combinatorial complexity induced by lexical ambiguity. In this paper, we detail an experiment that largely integrates these notions in a finite-state procedure of segmentation into super-chunks, preliminary to a parser.We show that the chunker, developped for French, reaches 92.9% precision and 98.7% recall. Moreover, multiword units realize 36.6% of the attachments within nominal and prepositional phrases. Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27133 ER - TY - JOUR A1 - Blaszczak, Joanna A1 - Dipper, Stefanie A1 - Fanselow, Gisbert A1 - Ishihara, Shinishiro A1 - Petrova, Svetlana A1 - Skopeteas, Stavros A1 - Weskott, Thomas A1 - Zimmermann, Malte T1 - Syntax JF - Interdisciplinary studies on information structure : ISIS N2 - The guidelines for syntactic annotation contain the layers that are especially relevant for queries related to the interaction of information structure with syntax. The layers of this level are constituent structure, grammatical functions, and semantic roles. Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-22253 SN - 1614-4708 SN - 1866-4725 IS - 7 SP - 95 EP - 133 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Blaszczak, Joanna A1 - Dipper, Stefanie A1 - Fanselow, Gisbert A1 - Ishihara, Shinishiro A1 - Petrova, Svetlana A1 - Skopeteas, Stavros A1 - Weskott, Thomas A1 - Zimmermann, Malte T1 - Morphology JF - Interdisciplinary studies on information structure : ISIS N2 - The guidelines for morphological annotation contain the layers that are necessary for understanding the structure of the words in the object language: morphological segmentation, glossing, and annotation of part-of-speech. Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-22247 SN - 1614-4708 SN - 1866-4725 IS - 7 SP - 55 EP - 94 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Blomme, R. T1 - Corotating Interaction Regions and clumping N2 - We present hydrodynamical models for Corotating Interaction Regions, which were used by Lobel (2007) to model the Discrete Absorption Components in HD 64760. We also discuss our failure to model the rotational modulations seen in the same star. Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18100 ER - TY - JOUR A1 - Bobda, Augustin Simo T1 - Irish presence in colonial Cameroon and its linguistic legacy JF - The Celtic Englishes IV : the interface between English and the Celtic languages ; proceedings of the fourth international colloquium on the "Celtic Englishes" held at the University of Potsdam in Golm (Germany) from 22-26 September 2004 N2 - Content: 1. Survey of Foreign Influences on English in Cameroon 1.1. Early Foreign Influences in the Formation of English in Cameroon 1.2. Later Influences 2. Irish Linguistic Legacy 2.1. Language Policy 2.2. Structural Aspects of English Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41011 SP - 217 EP - 233 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Bogost, Ian T1 - The phenomenology of videogames N2 - Jesper Juul has convincingly argued that the conflict over the proper object of study has shifted from “rules or story” to “player or game.” But a key component of digital games is still missing from either of these oppositions: that of the computer itself. This paper offers a way of thinking about the phenomenology of the videogame from the perspective of the computer rather than the game or the player. Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-24547 ER - TY - JOUR A1 - Boldrighini, Carlo A1 - Frigio, Sandro A1 - Maponi, Pierluigi A1 - Pellegrinotti, Alessandro A1 - Sinai, Yakov G. T1 - 3-D incompressible Navier-Stokes equations: Complex blow-up and related real flows JF - Lectures in pure and applied mathematics KW - random point processes KW - statistical mechanics KW - stochastic analysis Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472201 SN - 978-3-86956-485-2 SN - 2199-4951 SN - 2199-496X IS - 6 SP - 185 EP - 194 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Bomans, Dominik J. A1 - Becker, Andrew C. A1 - Kleemann, B. A1 - Weis, K. A1 - Pasquali, A. T1 - Luminous Wolf-Rayet stars at low metallicity JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - The evolution of massive stars in very low metallicity galaxies is less well observationally constrained than in environments more similar to the Milky Way, M33, or the LMC. We discuss in this contribution the current state of our program to search for and characterize Wolf-Rayet stars (and other massive emission line stars) in low metallicity galaxies in the Local Volume. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-87635 SP - 51 EP - 54 ER - TY - CHAP A1 - Bonfante, Guillaume A1 - Le Roux, Joseph T1 - Intersection optimization is NP-complete N2 - Finite state methods for natural language processing often require the construction and the intersection of several automata. In this paper, we investigate the question of determining the best order in which these intersections should be performed. We take as an example lexical disambiguation in polarity grammars. We show that there is no efficient way to minimize the state complexity of these intersections. Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27146 ER - TY - JOUR A1 - Borg, Erik A1 - Fichtelmann, Bernd T1 - Land-water masks: basis for automated pre- and thematic processing of remote sensing data JF - Potsdamer Geographische Praxis N2 - Earth observation data have become an outstanding basis for analyzing environmental aspects. The increasing availability of remote sensing data is accompanied by an increasing user demand. Within the scope of the COOPERNICUS-initiative, the automatic processing of remote sensing data is important for supplying value- added-information products. The use of additional data like land-water-masks in the context of deriving value-added information products can stabilize and improve the product quality of information products. The authors of this contribution would like to discuss different automated processing algorithms which are based on land-water masks for value-added data interpretation. These developments were supported or accompanied by Prof. Hartmut Asche. Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-103454 SN - 978-3-86956-389-3 SN - 2194–1599 SN - 2194–1602 IS - 12 SP - 77 EP - 99 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Bornkessel-Schlesewsky, Ina D. A1 - Schlesewsky, Matthias T1 - Is it a bird? Is it a mammal? BT - Perspectives on the learnability/trainability of new grammatical constructions JF - Of trees and birds. A Festschrift for Gisbert Fanselow KW - Festschrift KW - Informationsstruktur KW - Linguistik KW - Morphologie KW - Syntax KW - festschrift KW - information structure KW - linguistics KW - morphology KW - syntax Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-432534 SN - 978-3-86956-457-9 SP - 275 EP - 286 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Bortfeld, Silvia T1 - Analysis of Medicago truncatula transcription factors involved in the arbuscular mycorrhizal symbiosis T1 - Analyse von Medicago truncatula Transkriptionsfaktoren, die während der arbuskulären Mykorrhiz-Symbiose eine Rolle spielen N2 - For the first time the transcriptional reprogramming of distinct root cortex cells during the arbuscular mycorrhizal (AM) symbiosis was investigated by combining Laser Capture Mirodissection and Affymetrix GeneChip® Medicago genome array hybridization. The establishment of cryosections facilitated the isolation of high quality RNA in sufficient amounts from three different cortical cell types. The transcript profiles of arbuscule-containing cells (arb cells), non-arbuscule-containing cells (nac cells) of Rhizophagus irregularis inoculated Medicago truncatula roots and cortex cells of non-inoculated roots (cor) were successfully explored. The data gave new insights in the symbiosis-related cellular reorganization processes and indicated that already nac cells seem to be prepared for the upcoming fungal colonization. The mycorrhizal- and phosphate-dependent transcription of a GRAS TF family member (MtGras8) was detected in arb cells and mycorrhizal roots. MtGRAS shares a high sequence similarity to a GRAS TF suggested to be involved in the fungal colonization processes (MtRAM1). The function of MtGras8 was unraveled upon RNA interference- (RNAi-) mediated gene silencing. An AM symbiosis-dependent expression of a RNAi construct (MtPt4pro::gras8-RNAi) revealed a successful gene silencing of MtGras8 leading to a reduced arbuscule abundance and a higher proportion of deformed arbuscules in root with reduced transcript levels. Accordingly, MtGras8 might control the arbuscule development and life-time. The targeting of MtGras8 by the phosphate-dependent regulated miRNA5204* was discovered previously (Devers et al., 2011). Since miRNA5204* is known to be affected by phosphate, the posttranscriptional regulation might represent a link between phosphate signaling and arbuscule development. In this work, the posttranscriptional regulation was confirmed by mis-expression of miRNA5204* in M. truncatula roots. The miRNA-mediated gene silencing affects the MtGras8 transcript abundance only in the first two weeks of the AM symbiosis and the mis-expression lines seem to mimic the phenotype of MtGras8-RNAi lines. Additionally, MtGRAS8 seems to form heterodimers with NSP2 and RAM1, which are known to be key regulators of the fungal colonization process (Hirsch et al., 2009; Gobbato et al., 2012). These data indicate that MtGras8 and miRNA5204* are linked to the sym pathway and regulate the arbuscule development in phosphate-dependent manner. N2 - Die Leguminose Medicago truncatula (gehört zur Gattung des Schneckenklees) ist in der Lage sowohl eine Symbiose mit stickstofffixierenden Bakterien (Rhizobien), als auch mit Mykorrhiza-Pilzen einzugehen. Der Mykorrhiza-Pilz Rhizophagus irregularis dringt in die Wurzelrindenzellen ein und bildet Strukturen aus, die als Arbuskeln bezeichnet werden. Diese ermöglichen den Transfer von Nährstoffen, wie Phosphat in die Wurzelzellen. Die Pflanze liefert hingegen bis zu 20 % ihrer Photosyntheseprodukte an den Pilz. Da die Lebenszeit der Arbuskeln nur wenige Tage beträgt, können Wurzelrindenzellen mehrere Arbuskeln nacheinander beherbergen. Somit können neben arbuskelhaltigen, auch nicht-arbuskelhaltige Zellen in kolonisierten Wurzeln auftreten. Die nicht-arbuskelhaltigen Zellen beeinträchtigen die Sensitivität von Genregulationsanalysen, wenn die Genregulation während der Mykorrhiza-Symbiose anhand von ganzen kolonisierten Wurzeln untersucht wird. In dieser Arbeit konnte eine Zelltyp-spezifische Analyse der Genregulation von arbuskelhaltigen und nicht-arbuskelhaltigen Zellen durchgeführt, und eine Erhöhung der Sensitivität erreicht werden. Mittels Laser Capture Microdissection wurden Zellen aus Gefrierschnitten von Wurzeln isoliert. Aus den so gewonnen Zellen konnte RNA von ausreichender Qualität und Quantität extrahiert werden, um das Transkriptom der beiden Zelltypen mittels Mikroarrayhybridisierung zu untersuchen. Transkriptionsfaktoren (TFs) spielen wahrscheinlich eine Schlüsselrolle in der Umprogrammierung von Wurzelzellen während der Mykorrhiza-Symbiose. Daher wurde die Genregulation von TF-Genen in den zwei Zelltypen gezielt untersucht. Anhand von quantitativer RT-PCR und Promoter-Reporter-Fusionen wurde die differentielle Expression von mehreren TF-Transkripten in den verschiedenen Zelltypen bestätigt. Die Charakterisierung eines potentiellen GRAS TF (MtGRAS8) konnte eine stark Symbiose- und Phosphat-abhängige Induktion von Transkripten bestätigt werden. Mutanten mit verringerter MtGras8 Transkriptmenge wiesen eine verringerte Arbuskelzahl und deformierte Arbuskeln auf. MtGras8 scheint daher an der Arbuskelentwicklung beteiligt zu sein. Vorherige Experimente zeigten, dass MtGras8 Transkripte, von der Phosphat-regulierten MikroRNA5204* geschnitten werden (Devers et al., 2011). Dies konnte durch Überexpression der MikroRNA5204* in vivo bestätigt werden. Weiterhin konnten Protein-Protein-Interaktionen von MtGras8 mit bekannten GRAS TFs (NSP1, NSP2, RAM1) nachgewiesen und daraus eine Verbindung zu bekannten Symbiose-induzierten Signalkaskaden geschlossen werden. In dieser Arbeit wurde erstmals die Umprogrammierung von nicht-arbuskelhaltigen Zellen untersucht und neue Regulationselemente für die Kontrolle der Arbuskelentwicklung, wie MtGRAS8 und MikroRNA5204*, charakterisiert. KW - arbuskuläre Mykorrhiza-Symbiose KW - Transkriptionsfaktoren KW - Zelltyp-spezifisch KW - Transkriptomanalyse KW - arbuscular mycorrhizal symbiosis KW - transcription factors KW - cell type-specific KW - transcriptome analysis Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-70664 ER - TY - GEN A1 - Boston, Marisa Ferrara A1 - Hale, John A1 - Kliegl, Reinhold A1 - Patil, Umesh A1 - Vasishth, Shravan T1 - Parsing costs as predictors of reading difficulty: An evaluation using the Potsdam Sentence Corpus N2 - The surprisal of a word on a probabilistic grammar constitutes a promising complexity metric for human sentence comprehension difficulty. Using two different grammar types, surprisal is shown to have an effect on fixation durations and regression probabilities in a sample of German readers’ eye movements, the Potsdam Sentence Corpus. A linear mixed-effects model was used to quantify the effect of surprisal while taking into account unigram and bigram frequency, word length, and empirically-derived word predictability; the so-called “early” and “late” measures of processing difficulty both showed an effect of surprisal. Surprisal is also shown to have a small but statistically non-significant effect on empirically-derived predictability itself. This work thus demonstrates the importance of including parsing costs as a predictor of comprehension difficulty in models of reading, and suggests that a simple identification of syntactic parsing costs with early measures and late measures with durations of post-syntactic events may be difficult to uphold. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 253 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57139 ER - TY - GEN A1 - Boston, Marisa Ferrara A1 - Hale, John T. A1 - Vasishth, Shravan A1 - Kliegl, Reinhold T1 - Parallel processing and sentence comprehension difficulty N2 - Eye fixation durations during normal reading correlate with processing difficulty but the specific cognitive mechanisms reflected in these measures are not well understood. This study finds support in German readers’ eyefixations for two distinct difficulty metrics: surprisal, which reflects the change in probabilities across syntactic analyses as new words are integrated, and retrieval, which quantifies comprehension difficulty in terms of working memory constraints. We examine the predictions of both metrics using a family of dependency parsers indexed by an upper limit on the number of candidate syntactic analyses they retain at successive words. Surprisal models all fixation measures and regression probability. By contrast, retrieval does not model any measure in serial processing. As more candidate analyses are considered in parallel at each word, retrieval can account for the same measures as surprisal. This pattern suggests an important role for ranked parallelism in theories of sentence comprehension. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 252 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57159 ER - TY - JOUR A1 - Bottino, Rosa A1 - Chioccariello, Augusto T1 - Computational Thinking BT - Videogames, Educational Robotics, and other Powerful Ideas to Think with JF - KEYCIT 2014 - Key Competencies in Informatics and ICT N2 - Digital technology has radically changed the way people work in industry, finance, services, media and commerce. Informatics has contributed to the scientific and technological development of our society in general and to the digital revolution in particular. Computational thinking is the term indicating the key ideas of this discipline that might be included in the key competencies underlying the curriculum of compulsory education. The educational potential of informatics has a history dating back to the sixties. In this article, we briefly revisit this history looking for lessons learned. In particular, we focus on experiences of teaching and learning programming. However, computational thinking is more than coding. It is a way of thinking and practicing interactive dynamic modeling with computers. We advocate that learners can practice computational thinking in playful contexts where they can develop personal projects, for example building videogames and/or robots, share and discuss their construction with others. In our view, this approach allows an integration of computational thinking in the K-12 curriculum across disciplines. KW - Computational thinking KW - programming in context KW - informatics education Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-82820 SN - 1868-0844 SN - 2191-1940 IS - 7 SP - 301 EP - 309 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Bouret, J.-C. A1 - Lanz, T. A1 - Hillier, D. J. A1 - Foellmi, C. T1 - Clumping in O-type Supergiants N2 - We have analyzed the spectra of seven Galactic O4 supergiants, with the NLTE wind code CMFGEN. For all stars, we have found that clumped wind models match well lines from different species spanning a wavelength range from FUV to optical, and remain consistent with Hα data. We have achieved an excellent match of the P V λλ1118, 1128 resonance doublet and N IV λ1718, as well as He II λ4686 suggesting that our physical description of clumping is adequate. We find very small volume filling factors and that clumping starts deep in the wind, near the sonic point. The most crucial consequence of our analysis is that the mass loss rates of O stars need to be revised downward significantly, by a factor of 3 and more compared to those obtained from smooth-wind models. Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17662 ER - TY - JOUR A1 - Bowler, Margit ED - Grubic, Mira ED - Mucha, Anne T1 - The status of degrees in Warlpiri JF - Proceedings of the Semantics of African, Asian and Austronesian Languages (TripleA) 2 N2 - Recent work in semantics has shown that languages can vary in whether or not they include degrees (that is, elements of type < d >) in their semantic ontology. Several authors have argued that their languages of study lack degrees, including Bochnak (2013) for Washo (isolate, USA), Pearson (2009) for Fijian (Austronesian, Fiji), and Beck, et al. (2009) for Motu (Austronesian, Papua New Guinea). In this paper, I follow the tests proposed in Beck, et al. (2009) to assess the status of degrees in Warlpiri (Pama-Nyungan, Australia). I use Warlpiri data collected following the Beck, et al. survey to argue that Warlpiri gradable predicates do not combine with a degree argument. (Like many other Australian languages, adjectival concepts like big and small are expressed using nouns in Warlpiri (Dixon 1982, Bittner & Hale 1995, among others). I refer to these lexical items as “gradable predicates” in this paper.) This paper represents a first pass at assessing the status of degrees in an Australian language, which have otherwise been unexamined from the point of view of degree semantics. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-92295 SP - 1 EP - 17 ER - TY - CHAP A1 - Brass, Stefan T1 - Range restriction for general formulas N2 - Deductive databases need general formulas in rule bodies, not only conjuctions of literals. This is well known since the work of Lloyd and Topor about extended logic programming. Of course, formulas must be restricted in such a way that they can be effectively evaluated in finite time, and produce only a finite number of new tuples (in each iteration of the TP-operator: the fixpoint can still be infinite). It is also necessary to respect binding restrictions of built-in predicates: many of these predicates can be executed only when certain arguments are ground. Whereas for standard logic programming rules, questions of safety, allowedness, and range-restriction are relatively easy and well understood, the situation for general formulas is a bit more complicated. We give a syntactic analysis of formulas that guarantees the necessary properties. Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41521 ER - TY - JOUR A1 - Bratkin, Dimitri T1 - Manuscripts, Images, and Biographies of Daniel Chwolson BT - New Details from the Archives of St. Petersburg JF - PaRDES : Zeitschrift der Vereinigung für Jüdische Studien e. V. N2 - The St. Petersburg Branch of the Archive of the Russian Academy (PFA RAN) contains two manuscript biographies of Daniel Chwolson, the Russian-Jewish Orientalist, advocate of Jewish scholarship, and bridge builder to the Breslau Jewish Theological Seminary. They were written by his pupil and colleague, Pavel Kokovtsov, and his grandson Yevgeny Chwolson, respectively. These two texts are studied against the background of published texts and popular opinion of Chwolson in late Imperial Russia. Apart from some details, these manuscripts offer limited additional information as factual sources, most of their contents being mere variation of published texts. However, the biography of Chwolson written by his grandson is a valuable source on the reception of Chwolson and illustrates the potential of further mythological appreciation of his personality and works in the Soviet time as a defense strategy for Chwolson’s family. It also contains crucial information on the fate of Chwolson’s archive. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-417884 SP - 171 EP - 189 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - INPR A1 - Brauer, Uwe A1 - Karp, Lavi T1 - Local existence of classical solutions for the Einstein-Euler system using weighted Sobolev spaces of fractional order N2 - We prove the existence of a class of local in time solutions, including static solutions, of the Einstein-Euler system. This result is the relativistic generalisation of a similar result for the Euler-Poisson system obtained by Gamblin [8]. As in his case the initial data of the density do not have compact support but fall off at infinity in an appropriate manner. An essential tool in our approach is the construction and use of weighted Sobolev spaces of fractional order. Moreover, these new spaces allow us to improve the regularity conditions for the solutions of evolution equations. The details of this construction, the properties of these spaces and results on elliptic and hyperbolic equations will be presented in a forthcoming article. T3 - Preprint - (2006) 17 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-30175 ER - TY - INPR A1 - Brauer, Uwe A1 - Karp, Lavi T1 - Well-posedness of Einstein-Euler systems in asymptotically flat spacetimes N2 - We prove a local in time existence and uniqueness theorem of classical solutions of the coupled Einstein{Euler system, and therefore establish the well posedness of this system. We use the condition that the energy density might vanish or tends to zero at infinity and that the pressure is a certain function of the energy density, conditions which are used to describe simplified stellar models. In order to achieve our goals we are enforced, by the complexity of the problem, to deal with these equations in a new type of weighted Sobolev spaces of fractional order. Beside their construction, we develop tools for PDEs and techniques for hyperbolic and elliptic equations in these spaces. The well posedness is obtained in these spaces. T3 - Preprint - (2008) 07 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-30347 ER - TY - RPRT A1 - Braun, Harald T1 - Berlin – New York BT - A Few Observations on Germany in the United Nations T2 - KFG Working Paper Series N2 - Beginning in January 2019, the new German government will face a particular new responsibility for world affairs: provided the elections in June 2018 lead to the desired result, Germany will be an elected member of the UN Security Council for two years from January 2019 until December 2020. However, Germany has been a respected and highly relevant member of the United Nations not only during its terms on the Security Council but also in “normal” times. The present article attempts to shed light on a few aspects of Germany’s role in the UN during Merkel’s chancellorship with an emphasis on her third term (2014-2017), such as the cooperative relationship between Germany and the UN Secretary-General in important policy fields, Germany’s financial contributions to the UN, the impact of Germany’s EU membership on its UN membership and the country’s efforts with regard to the reform of the Security Council. The paper further provides context for Germany’s abstention in the vote on Security Council Resolution 1973 on Libya in 2011. It concludes by ascertaining that Germany with its approach of active multilateralism has taken its place as one of the leading nations in Europe and is ready to take on responsibility with its partners to achieve a peaceful and stable world order. T3 - KFG Working Paper Series - 11 Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-421984 SN - 2509-3770 SN - 2509-3762 IS - 11 ER - TY - INPR A1 - Braun, Robert A1 - Feudel, Fred T1 - Supertransient chaos in the two-dimensional complex Ginzburg-Landau equation N2 - We have shown that the two-dimensional complex Ginzburg-Landau equation exhibits supertransient chaos in a certain parameter range. Using numerical methods this behavior is found near the transition line separating frozen spiral solutions from turbulence. Supertransient chaos seems to be a common phenomenon in extended spatiotemporal systems. These supertransients are characterized by an average transient lifetime which depends exponentially on the size of the system and are due to an underlying nonattracting chaotic set. T3 - NLD Preprints - 29 Y1 - 1996 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14099 ER - TY - INPR A1 - Braun, Robert A1 - Feudel, Fred A1 - Guzdar, Parvez T1 - The route to chaos for a two-dimensional externally driven flow N2 - We have numerically studied the bifurcations and transition to chaos in a two-dimensional fluid for varying values of the Reynolds number. These investigations have been motivated by experiments in fluids, where an array of vortices was driven by an electromotive force. In these experiments, successive changes leading to a complex motion of the vortices, due to increased forcing, have been explored [Tabeling, Perrin, and Fauve, J. Fluid Mech. 213, 511 (1990)]. We model this experiment by means of two-dimensional Navier-Stokes equations with a special external forcing, driving a linear chain of eight counter-rotating vortices, imposing stress-free boundary conditions in the vertical direction and periodic boundary conditions in the horizontal direction. As the strength of the forcing or the Reynolds number is raised, the original stationary vortex array becomes unstable and a complex sequence of bifurcations is observed. Several steady states and periodic branches and a period doubling cascade appear on the route to chaos. For increasing values of the Reynolds number, shear flow develops, for which the spatial scale is large compared to the scale of the forcing. Furthermore, we have investigated the influence of the aspect ratio of the container as well as the effect of no-slip boundary conditions at the top and bottom, on the bifurcation scenario. T3 - NLD Preprints - 46 Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14717 ER - TY - INPR A1 - Braun, Robert A1 - Feudel, Fred A1 - Seehafer, Norbert T1 - Bifurcations and chaos in an array of forced vortices N2 - We have studied the bifurcation structure of the incompressible two-dimensional Navier-Stokes equations with a special external forcing driving an array of 8×8 counterrotating vortices. The study has been motivated by recent experiments with thin layers of electrolytes showing, among other things, the formation of large-scale spatial patterns. As the strength of the forcing or the Reynolds number is raised the original stationary vortex array becomes unstable and a complex sequence of bifurcations is observed. The bifurcations lead to several periodic branches, torus and chaotic solutions, and other stationary solutions. Most remarkable is the appearance of solutions characterized by structures on spatial scales large compared to the scale of the forcing. We also characterize the different dynamic regimes by means of tracers injected into the fluid. Stretching rates and Hausdorff dimensions of convected line elements are calculated to quantify the mixing process. It turns out that for time-periodic velocity fields the mixing can be very effective. T3 - NLD Preprints - 37 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14564 ER - TY - BOOK A1 - Breest, Martin A1 - Bouché, Paul A1 - Grund, Martin A1 - Haubrock, Sören A1 - Hüttenrauch, Stefan A1 - Kylau, Uwe A1 - Ploskonos, Anna A1 - Queck, Tobias A1 - Schreiter, Torben T1 - Fundamentals of Service-Oriented Engineering N2 - Since 2002, keywords like service-oriented engineering, service-oriented computing, and service-oriented architecture have been widely used in research, education, and enterprises. These and related terms are often misunderstood or used incorrectly. To correct these misunderstandings, a deeper knowledge of the concepts, the historical backgrounds, and an overview of service-oriented architectures is demanded and given in this paper. T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 16 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-33801 SN - 978-3-939469-35-3 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Briesemeister, Benny B. A1 - Hofmann, Markus J. A1 - Kuchinke, Lars A1 - Jacobs, Arthur M. T1 - The BAWL databases in research on emotional word processing JF - Potsdam cognitive science series N2 - Inhalt: Introduction A two-dimensional affective space: Valence and arousal effects in word processing Higher dimensional affective space: a role of discrete emotions in word processing? A direct comparison of the affective space models References Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-62377 SN - 2190-4545 SN - 2190-4553 IS - 3 SP - 61 EP - 66 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Brilke, Clara A1 - Werner, Eva ED - Rollinger, Christian T1 - I am not sure that I feel like singing, thanks very much for asking! BT - Interview with Natalie Haynes JF - thersites 12 N2 - In her writings on ancient myth, the British author Natalie Haynes moves women to the centre of attention. Her two latest books, A Thousand Ships and Pandora’s Jar – a fiction novel and a non-fiction one – approach this topic from two different perspectives. This interview takes stock of Haynes’ motives and methodology as well as of the challenges she faces in the process of writing. KW - Women in Ancient Myth KW - Classical Reception KW - Classics in Popular Culture Y1 - 2021 U6 - https://doi.org/10.34679/thersites.vol12.189 SN - 2364-7612 VL - 2020 IS - 12 SP - 104 EP - 115 ER - TY - GEN A1 - Bringmann, Gerhard A1 - Mutanyatta-Comar, Joan A1 - Maksimenka, Katja A1 - Wanjohi, John M. A1 - Heydenreich, Matthias A1 - Brun, Reto A1 - Müller, Werner E. G. A1 - Peter, Martin A1 - Midiwo, Jacob O. A1 - Yenesew, Abiy T1 - Joziknipholones A and B : the First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens N2 - From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 104 KW - antimalarial activity KW - chirality KW - joziknipholones KW - natural products KW - structure elucidation Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42638 ER - TY - JOUR A1 - Brodehser, Peter T1 - Quo Vadis Infrastructure Financing? JF - Protokollband 2013 N2 - 1. Introduction 2. The project finance market in 2006/2007 3. Areas affected by the global financial crisis 4. Areas affected by the euro financial crisis 5. Basel III and the consequences for infrastructure financing 6. Outlook – Where do we go from here? Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-68738 SP - 119 EP - 132 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Brodt, Eliezer T1 - Mattityahu Strashun (1817–1885) and His Relationship with the Early Founders of Wissenschaft des Judentums JF - PaRDES : Zeitschrift der Vereinigung für Jüdische Studien e. V. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-417788 SP - 27 EP - 45 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Broekhuis, Hans T1 - Derivations (MP) and evaluations (OT) JF - Linguistics in Potsdam N2 - The main claim of this paper is that the minimalist framework and optimality theory adopt more or less the same architecture of grammar: both assume that a generator defines a set S of potentially well-formed expressions that can be generated on the basis of a given input, and that there is an evaluator that selects the expressions from S that are actually grammatical in a given language L. The paper therefore proposes a model of grammar in which the strengths of the two frameworks are combined: more specifically, it is argued that the computational system of human language CHL from MP creates a set S of potentially well-formed expressions, and that these are subsequently evaluated in an optimality theoretic fashion. KW - Minimalist Program KW - Optimality Theory KW - Derivation-and-Evaluation model KW - Object Shift Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-32347 SN - 1616-7392 SN - 1864-1857 IS - 25 SP - 137 EP - 193 ER - TY - JOUR A1 - Brooks, Clare T1 - The EVE curriculum framework BT - developments on the second phase JF - Potsdamer geographische Praxis N2 - 1. Evaluations 2. Main changes to the curriculum Framework 3. Looking Forwards KW - Europäische Werteerziehung KW - Familie KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - Family KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-66128 SN - 2194-1599 SN - 2194-1602 IS - 1 SP - 17 EP - 20 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Brooks, Clare T1 - The EVE curriculum framework BT - the third instalment JF - Potsdamer geographische Praxis N2 - 1. The new approach 2. Changes to the Curriculum Framework KW - Europäische Werteerziehung KW - Familie KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - Family KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-65918 SN - 2194-1599 SN - 2194-1602 IS - 3 SP - 23 EP - 27 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Brothers, Soren M. T1 - Carbon gains, losses, and feedbacks in shallow, eutrophic lakes of phytoplankton and macrophyte dominance T1 - Kohlenstoff-Gewinne, Verluste und Rückkopplungen in flachen, nährstoffreichen Seen mit Dominanz von Phytoplankton und Makrophyten N2 - Lakes are increasingly being recognized as an important component of the global carbon cycle, yet anthropogenic activities that alter their community structure may change the way they transport and process carbon. This research focuses on the relationship between carbon cycling and community structure of primary producers in small, shallow lakes, which are the most abundant lake type in the world, and furthermore subject to intense terrestrial-aquatic coupling due to their high perimeter:area ratio. Shifts between macrophyte and phytoplankton dominance are widespread and common in shallow lakes, with potentially large consequences to regional carbon cycling. I thus compared a lake with clear-water conditions and a submerged macrophyte community to a turbid, phytoplankton-dominated lake, describing differences in the availability, processing, and export of organic and inorganic carbon. I furthermore examined the effects of increasing terrestrial carbon inputs on internal carbon cycling processes. Pelagic diel (24-hour) oxygen curves and independent fluorometric approaches of individual primary producers together indicated that the presence of a submerged macrophyte community facilitated higher annual rates of gross primary production than could be supported in a phytoplankton-dominated lake at similar nutrient concentrations. A simple model constructed from the empirical data suggested that this difference between regime types could be common in moderately eutrophic lakes with mean depths under three to four meters, where benthic primary production is a potentially major contributor to the whole-lake primary production. It thus appears likely that a regime shift from macrophyte to phytoplankton dominance in shallow lakes would typically decrease the quantity of autochthonous organic carbon available to lake food webs. Sediment core analyses indicated that a regime shift from macrophyte to phytoplankton dominance was associated with a four-fold increase in carbon burial rates, signalling a major change in lake carbon cycling dynamics. Carbon mass balances suggested that increasing carbon burial rates were not due to an increase in primary production or allochthonous loading, but instead were due to a higher carbon burial efficiency (carbon burial / carbon deposition). This, in turn, was associated with diminished benthic mineralization rates and an increase in calcite precipitation, together resulting in lower surface carbon dioxide emissions. Finally, a period of unusually high precipitation led to rising water levels, resulting in a feedback loop linking increasing concentrations of dissolved organic carbon (DOC) to severely anoxic conditions in the phytoplankton-dominated system. High water levels and DOC concentrations diminished benthic primary production (via shading) and boosted pelagic respiration rates, diminishing the hypolimnetic oxygen supply. The resulting anoxia created redox conditions which led to a major release of nutrients, DOC, and iron from the sediments. This further transformed the lake metabolism, providing a prolonged summertime anoxia below a water depth of 1 m, and leading to the near-complete loss of fish and macroinvertebrates. Pelagic pH levels also decreased significantly, increasing surface carbon dioxide emissions by an order of magnitude compared to previous years. Altogether, this thesis adds an important body of knowledge to our understanding of the significance of the benthic zone to carbon cycling in shallow lakes. The contribution of the benthic zone towards whole-lake primary production was quantified, and was identified as an important but vulnerable site for primary production. Benthic mineralization rates were furthermore found to influence carbon burial and surface emission rates, and benthic primary productivity played an important role in determining hypolimnetic oxygen availability, thus controlling the internal sediment loading of nutrients and carbon. This thesis also uniquely demonstrates that the ecological community structure (i.e. stable regime) of a eutrophic, shallow lake can significantly influence carbon availability and processing. By changing carbon cycling pathways, regime shifts in shallow lakes may significantly alter the role of these ecosystems with respect to the global carbon cycle. N2 - Seen werden zunehmend als wichtige Komponente im globalen Kohlenstoffkreislauf anerkannt. Natürliche Veränderungen und anthropogene Aktivitäten beeinflussen die Struktur der Artengemeinschaft von Seen, was Auswirkungen auf den Transport und Umsatz von Kohlenstoff hat. Diese Arbeit konzentriert sich auf die Beziehung zwischen Kohlenstoffkreislauf und der Gemeinschaftsstruktur der Primärproduzenten in kleinen Flachseen. Diese sind der weltweit häufigste Seentyp und weisen durch ihren im Vergleich zur Fläche großen Umfang eine intensive aquatisch-terrestrische Kopplung auf. In Flachseen treten oft Regimewechsel zwischen Makrophyten- und Phytoplankton-Dominanz auf. Diese können potenziell große Konsequenzen für den regionalen Kohlenstoffkreislauf haben. In dieser Dissertation vergleiche ich einen Klarwassersee mit submersen Makrophyten und einen trüben, Phytoplankton-dominierten See hinsichtlich Verfügbarkeit, Umsatz und Export von organischem und anorganischem Kohlenstoff. Des Weiteren habe ich den Effekt der erhöhten Zufuhr von terrestrischem Kohlenstoff auf den internen Kohlenstoffumsatz untersucht. Sowohl die Tagesgänge der pelagischen Sauerstoff-Konzentrationen als auch Fluoreszenz-basierte Messungen der Primärproduktion bewiesen, dass die Präsenz von submersen Makrophyten eine höhere jährliche Brutto-Primärproduktion im Vergleich zu einem Phytoplankton-dominierten See mit ähnlichen Nährstoffkonzentrationen ermöglicht. Ein einfaches, auf den empirischen Daten basierendes Model zeigt, dass diese Unterschiede in der Brutto-Primärproduktion typisch sind für moderat eutrophe Seen mit einer mittleren Tiefe von unter 3 bis vier Metern. In diesen Seen leistet die benthische Primärproduktion den Hauptbeitrag zur Primärproduktion des ganzen Sees. Daraus wird ersichtlich, dass Regimewechsel von Makrophyten- zur Phytoplankton-Dominanz in Flachseen die Verfügbarkeit von autochthonem organischem Kohlenstoff für das Nahrungsnetz reduzieren. Paläolimnologische Analysen in Sedimentkernen beider Seen wiesen darauf hin, dass der Verlust der Makrophyten mit einer vierfachen Zunahme der Kohlenstoff-Speicherraten einhergeht, und somit zu einer großen Veränderung der Dynamik des Kohlenstoffkreislaufs im See führt. Unsere Kohlenstoff-Massenbilanzen zeigen, dass die Erhöhung der Kohlenstoff-Speicherung im Sediment nicht durch die Erhöhung der Primärproduktion oder durch externe Quellen, sondern durch erhöhte der Effizienz der Speicherung begründet war. Dies geht mit einer reduzierten benthischen Mineralisierungsrate und einer erhöhten Calcitfällung einher und führt zu reduzierten Kohlendioxid-Emissionen. Eine Periode ungewöhnlich hoher Niederschläge mit erhöhten Wasserständen führte im Phytoplankton-dominierten See zu zu einem starken Anstieg der Konzentrationen an gelöstem organischem Kohlenstoff (DOC) und zu anoxischen Bedingungen. Es wurde postuliert, dass zwischen diesen Prozessen eine positive Rückkopplung besteht. Die hohen Wasserstände und DOC-Konzentrationen reduzierten die Lichtversorgung und damit die Primärproduktion im Benthal und erhöhten die pelagischen Respirationsraten. Dadurch verringerte sich die Sauerstoffverfügbarkeit im Hypolimnion. Die dadurch erzeugten Redox-Verhältnisse führten zu einer Freisetzung großer Mengen an Nährstoffen, DOC und Eisen aus dem Sediment. Die während des gesamten Sommers andauernden anoxischen Verhältnisse in Wassertiefen unter 1 m führten zu einem fast vollständigen Verlust von Fischen und Makroinvertebraten. Zusätzlich wurde der pH-Wert im Pelagial signifikant erniedrigt und die Kohlenstoffdioxid-Emissionen im Vergleich zu früheren Jahren verzehnfacht. Insgesamt trägt diese Dissertation wesentliche Aspekte zum besseren Verständnis der Bedeutung des Benthals für den Kohlenstoffkreislauf in Flachseen bei. Der Anteil der benthischen Zone an der Primärproduktion in kleinen Flachseen wurde in Relation zur Gesamtproduktion des Systems quantifiziert. Letztlich zeigt diese Arbeit, dass die Gemeinschaftsstruktur der Primärproduzenten eines eutrophen Flachsees die Verfügbarkeit und den Umsatz von Kohlenstoff signifikant beeinflusst. Regimewechsel in Flachseen können durch Änderungen im internen Kohlenstoffkreislauf deren Rolle im globalen Kohlenstoffkreislauf verändern. KW - Carbon Cycling KW - Primärproduktion KW - Anoxie KW - Brownification KW - Carbon cycling KW - primary production KW - anoxia KW - brownification Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-68200 ER - TY - JOUR A1 - Bröker, Kathrin A1 - Kastens, Uwe A1 - Magenheim, Johannes T1 - Competences of Undergraduate Computer Science Students JF - KEYCIT 2014 - Key Competencies in Informatics and ICT N2 - The paper presents two approaches to the development of a Computer Science Competence Model for the needs of curriculum development and evaluation in Higher Education. A normativetheoretical approach is based on the AKT and ACM/IEEE curriculum and will be used within the recommendations of the German Informatics Society (GI) for the design of CS curricula. An empirically oriented approach refines the categories of the first one with regard to specific subject areas by conducting content analysis on CS curricula of important universities from several countries. The refined model will be used for the needs of students’ e-assessment and subsequent affirmative action of the CS departments. KW - Competences KW - Competence Measurement KW - Curriculum Development KW - Computer Science Education KW - Recommendations for CS-Curricula in Higher Education Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-82613 SN - 1868-0844 SN - 2191-1940 IS - 7 SP - 77 EP - 96 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Bubeck, Christoph A1 - Laschewsky, André A1 - Lupo, Donald A1 - Neher, Dieter A1 - Ottenbreit, Petra A1 - Paulus, Wolfgang A1 - Prass, Werner A1 - Ringsdorf, Helmut A1 - Wegner, Gerhard T1 - Amphiphilic dyes for nonlinear optics: Dependence of second harmonic generation on functional group substitution T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 082 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17201 ER - TY - JOUR A1 - Buchem, Ilona A1 - Okatan, Ebru T1 - Using the Addie Model to Produce MOOCs BT - Experiences from the Oberred Project JF - EMOOCs 2021 N2 - MOOCs have been produced using a variety of instructional design approaches and frameworks. This paper presents experiences from the instructional approach based on the ADDIE model applied to designing and producing MOOCs in the Erasmus+ strategic partnership on Open Badge Ecosystem for Research Data Management (OBERRED). Specifically, this paper describes the case study of the production of the MOOC “Open Badges for Open Science”, delivered on the European MOOC platform EMMA. The key goal of this MOOC is to help learners develop a capacity to use Open Badges in the field of Research Data Management (RDM). To produce the MOOC, the ADDIE model was applied as a generic instructional design model and a systematic approach to the design and development following the five design phases: Analysis, Design, Development, Implementation, Evaluation. This paper outlines the MOOC production including methods, templates and tools used in this process including the interactive micro-content created with H5P in form of Open Educational Resources and digital credentials created with Open Badges and issued to MOOC participants upon successful completion of MOOC levels. The paper also outlines the results from qualitative evaluation, which applied the cognitive walkthrough methodology to elicit user requirements. The paper ends with conclusions about pros and cons of using the ADDIE model in MOOC production and formulates recommendations for further work in this area. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-517274 SN - 978-3-86956-512-5 VL - 2021 SP - 249 EP - 258 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - INPR A1 - Buchholz, Thilo A1 - Schulze, Bert-Wolfgang T1 - Volterra operators and parabolicity : anisotropic pseudo-differential operators N2 - Parabolic equations on manifolds with singularities require a new calculus of anisotropic pseudo-differential operators with operator-valued symbols. The paper develops this theory along the lines of sn abstract wedge calculus with strongly continuous groups of isomorphisms on the involved Banach spaces. The corresponding pseodo-diferential operators are continuous in anisotropic wedge Sobolev spaces, and they form an alegbra. There is then introduced the concept of anisotropic parameter-dependent ellipticity, based on an order reduction variant of the pseudo-differential calculus. The theory is appled to a class of parabolic differential operators, and it is proved the invertibility in Sobolev spaces with exponential weights at infinity in time direction. T3 - Preprint - (1998) 11 Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-25231 ER -