TY - BOOK A1 - Mientus, Lukas A1 - Klempin, Christiane A1 - Nowak, Anna A1 - Wyss, Corinne A1 - Aufschnaiter, Claudia von A1 - Faix, Ann-Christin A1 - te Poel, Kathrin A1 - Wahbe, Nadia A1 - Pieper, Martin A1 - Höller, Katharina A1 - Kallenbach, Lea A1 - Förster, Magdalena A1 - Redecker, Anke A1 - Dick, Mirjam A1 - Holle, Jörg A1 - Schneider, Edina A1 - Rehfeldt, Daniel A1 - Brauns, Sarah A1 - Abels, Simone A1 - Ferencik-Lehmkuhl, Daria A1 - Fränkel, Silvia A1 - Frohn, Julia A1 - Liebsch, Ann-Catherine A1 - Pech, Detlef A1 - Schreier, Pascal A1 - Jessen, Moiken A1 - Großmann, Uta A1 - Skintey, Lesya A1 - Voerkel, Paul A1 - Vaz Ferreira, Mergenfel A. A1 - Zimmermann, Jan-Simon A1 - Buddeberg, Magdalena A1 - Henke, Vanessa A1 - Hornberg, Sabine A1 - Völschow, Yvette A1 - Warrelmann, Julia-Nadine A1 - Malek, Jennifer A1 - Tinnefeld, Anja A1 - Schmidt, Peggy A1 - Bauer, Tobias A1 - Jänisch, Christopher A1 - Spitzer, Lisa A1 - Franken, Nadine A1 - Degeling, Maria A1 - Preisfeld, Angelika A1 - Meier, Jana A1 - Küth, Simon A1 - Scholl, Daniel A1 - Vogelsang, Christoph A1 - Watson, Christina A1 - Weißbach, Anna A1 - Kulgemeyer, Christoph A1 - Oetken, Mandy A1 - Gorski, Sebastian A1 - Kubsch, Marcus A1 - Sorge, Stefan A1 - Wulff, Peter A1 - Fellenz, Carolin D. A1 - Schnell, Susanne A1 - Larisch, Cathleen A1 - Kaiser, Franz A1 - Knott, Christina A1 - Reimer, Stefanie A1 - Stegmüller, Nathalie A1 - Boukrayâa Trabelsi, Kathrin A1 - Schißlbauer, Franziska A1 - Lemberger, Lukas A1 - Barth, Ulrike A1 - Wiehl, Angelika A1 - Rogge, Tim A1 - Böhnke, Anja A1 - Dietz, Dennis A1 - Großmann, Leroy A1 - Wienmeister, Annett A1 - Zoppke, Till A1 - Jiang, Lisa A1 - Grünbauer, Stephanie A1 - Ostersehlt, Dörte A1 - Peukert, Sophia A1 - Schäfer, Christoph A1 - Löbig, Anna A1 - Bröll, Leena A1 - Brandt, Birgit A1 - Breuer, Meike A1 - Dausend, Henriette A1 - Krelle, Michael A1 - Andersen, Gesine A1 - Falke, Sascha A1 - Kindermann-Güzel, Kristin A1 - Körner, Katrina A1 - Lottermoser, Lisa-Marie A1 - Pügner, Kati A1 - Sonnenburg, Nadine A1 - Akarsu, Selim A1 - Rechl, Friederike A1 - Gadinger, Laureen A1 - Heinze, Lena A1 - Wittmann, Eveline A1 - Franke, Manuela A1 - Lachmund, Anne-Marie A1 - Böttger, Julia A1 - Hannover, Bettina A1 - Behrendt, Renata A1 - Conty, Valentina A1 - Grundmann, Stephanie A1 - Ghassemi, Novid A1 - Opitz, Ben A1 - Brämer, Martin A1 - Gasparjan, David A1 - Sambanis, Michaela A1 - Köster, Hilde A1 - Lücke, Martin A1 - Nordmeier, Volkhard A1 - Schaal, Sonja A1 - Haberbosch, Maximilian A1 - Meissner, Maren A1 - Schaal, Steffen A1 - Brüchner, Melanie A1 - Riehle, Tamara A1 - Leopold, Bengta Marie A1 - Gerlach, Susanne A1 - Rau-Patschke, Sarah A1 - Skorsetz, Nina A1 - Weber, Nadine A1 - Damköhler, Jens A1 - Elsholz, Markus A1 - Trefzger, Thomas A1 - Lewek, Tobias A1 - Borowski, Andreas ED - Mientus, Lukas ED - Klempin, Christiane ED - Nowak, Anna T1 - Reflexion in der Lehrkräftebildung BT - Empirisch – Phasenübergreifend – Interdisziplinär T3 - Potsdamer Beiträge für Lehrkräftebildung und Bildungsforschung N2 - Reflexion ist eine Schlüsselkategorie für die professionelle Entwicklung von Lehrkräften, welche als Ausbildungsziel in den Bildungsstandards für die Lehrkräftebildung verankert ist. Eine Verstetigung universitär geprägter Forschung und Modellierung in der praxisnahen Anwendung im schulischen Kontext bietet Potentiale nachhaltiger Professionalisierung. Die Stärkung reflexionsbezogener Kompetenzen durch Empirie und Anwendung scheint eine phasenübergreifende Herausforderung der Lehrkräftebildung zu sein, die es zu bewältigen gilt. Ziele des Tagungsbandes Reflexion in der Lehrkräftebildung sind eine theoretische Schärfung des Konzeptes „Reflexive Professionalisierung“ und der Austausch über Fragen der Einbettung wirksamer reflexionsbezogener Lerngelegenheiten in die Lehrkräftebildung. Forschende und Lehrende der‚ drei Phasen (Studium, Referendariat sowie Fort- und Weiterbildung) der Lehrkräftebildung stellen Lehrkonzepte und Forschungsprojekte zum Thema Reflexion in der Lehrkräftebildung vor und diskutieren diese. Gemeinsam mit Teilnehmenden aller Phasen und von verschiedenen Standorten der Lehrkräftebildung werden zukünftige Herausforderungen identifiziert und Lösungsansätze herausgearbeitet. T3 - Potsdamer Beiträge zur Lehrkräftebildung und Bildungsforschung - 4 KW - Reflexion KW - Lehrkräftebildung KW - Reflexionskompetenz KW - Reflexivität KW - Feedback KW - Reflection KW - Teacher Education KW - Reflection Skills KW - Reflexivity KW - Feedback Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-591717 SN - 978-3-86956-566-8 SN - 2626-3556 SN - 2626-4722 IS - 4 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Comas-Bru, Laia A1 - Harrison, Sandy P. A1 - Werner, Martin A1 - Rehfeld, Kira A1 - Scroxton, Nick A1 - Veiga-Pires, Cristina A1 - Ahmad, Syed Masood A1 - Brahim, Yassine Ait A1 - Mozhdehi, Sahar Amirnezhad A1 - Arienzo, Monica A1 - Atsawawaranunt, Kamolphat A1 - Baker, Andy A1 - Braun, Kerstin A1 - Breitenbach, Sebastian Franz Martin A1 - Burstyn, Yuval A1 - Chawchai, Sakonvan A1 - Columbu, Andrea A1 - Deininger, Michael A1 - Demeny, Attila A1 - Dixon, Bronwyn A1 - Hatvani, Istvan Gabor A1 - Hu, Jun A1 - Kaushal, Nikita A1 - Kern, Zoltan A1 - Labuhn, Inga A1 - Lachniet, Matthew S. A1 - Lechleitner, Franziska A. A1 - Lorrey, Andrew A1 - Markowska, Monika A1 - Nehme, Carole A1 - Novello, Valdir F. A1 - Oster, Jessica A1 - Perez-Mejias, Carlos A1 - Pickering, Robyn A1 - Sekhon, Natasha A1 - Wang, Xianfeng A1 - Warken, Sophie A1 - Atkinson, Tim A1 - Ayalon, Avner A1 - Baldini, James A1 - Bar-Matthews, Miryam A1 - Bernal, Juan Pablo A1 - Boch, Ronny A1 - Borsato, Andrea A1 - Boyd, Meighan A1 - Brierley, Chris A1 - Cai, Yanjun A1 - Carolin, Stacy A1 - Cheng, Hai A1 - Constantin, Silviu A1 - Couchoud, Isabelle A1 - Cruz, Francisco A1 - Denniston, Rhawn A1 - Dragusin, Virgil A1 - Duan, Wuhui A1 - Ersek, Vasile A1 - Finne, Martin A1 - Fleitmann, Dominik A1 - Fohlmeister, Jens Bernd A1 - Frappier, Amy A1 - Genty, Dominique A1 - Holzkamper, Steffen A1 - Hopley, Philip A1 - Johnston, Vanessa A1 - Kathayat, Gayatri A1 - Keenan-Jones, Duncan A1 - Koltai, Gabriella A1 - Li, Ting-Yong A1 - Lone, Mahjoor Ahmad A1 - Luetscher, Marc A1 - Mattey, Dave A1 - Moreno, Ana A1 - Moseley, Gina A1 - Psomiadis, David A1 - Ruan, Jiaoyang A1 - Scholz, Denis A1 - Sha, Lijuan A1 - Smith, Andrew Christopher A1 - Strikis, Nicolas A1 - Treble, Pauline A1 - Unal-Imer, Ezgi A1 - Vaks, Anton A1 - Vansteenberge, Stef A1 - Voarintsoa, Ny Riavo G. A1 - Wong, Corinne A1 - Wortham, Barbara A1 - Wurtzel, Jennifer A1 - Zhang, Haiwei T1 - Evaluating model outputs using integrated global speleothem records of climate change since the last glacial JF - Climate of the past : an interactive open access journal of the European Geosciences Union N2 - Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data–model comparisons. Here, we illustrate this using 456 globally distributed speleothem δ18O records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data–model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on δ18O values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices. Y1 - 2019 U6 - https://doi.org/10.5194/cp-15-1557-2019 SN - 1814-9324 SN - 1814-9332 VL - 15 IS - 4 SP - 1557 EP - 1579 PB - Copernicus CY - Göttingen ER - TY - BOOK A1 - Neumann, Martin A1 - Brandt-Wardenberg, Henriette A1 - Brodowsky, Kristin A1 - Ebert, Daniel A1 - Hose, Susanne A1 - Junge, Katrin A1 - Kappler, Anna A1 - Karges, Melanie A1 - Lehnert, Annette A1 - Richter, Olivia A1 - Schirrmeister, Sebastian A1 - Solich, Raphaela A1 - Thaele, Liisa A1 - Trenkner, Christina A1 - Tschöpel, Sebastian A1 - Unger, Katharina A1 - Winkler, Anja A1 - Zimmermann, Steven A1 - Kirschke, Andreas A1 - Ladusch, Manfred T1 - Sorben (Wenden) - Eine Brandenburger Minderheit und ihre Thematisierung im Unterricht : Teil III: Krabat - Aspekte einer sorbischen Sage N2 - Die vorliegende Publikation fällt ein wenig aus dem Rahmen der Reihe „Sorben (Wenden) - Eine Brandenburger Minderheit und ihre Thematisierung im Unterricht“. Im Gegensatz zu den anderen Teilen widmet sie sich nur einem Gegenstand - dem Stoff der Krabat-Sagen. Damit richtet sie sich hauptsächlich an Lehrkräfte im Fach Deutsch, wobei auch fachübergreifende und Fächer verbindende Aspekte berücksichtigt werden. Die Krabat-Sage zählt vor allem in der Bearbeitung von Preußler zu den bekanntesten sorbischen Stoffen. Diese sorbischen Wurzeln werden allerdings nur selten thematisiert. Daher sind viele der vorliegenden Betrachtungen zu ausgewählten Aspekten auch als Anregungen zu verstehen, unter welchen Gesichtspunkten Krabat behandelt oder gar neu interpretiert und weiterentwickelt werden könnte. Diese Handreichung ist so konzipiert, dass sie je nach Interesse ausschnittweise gelesen werden kann: Auf einen Überblick über verschiedene Krabat-Bearbeitungen folgen Betrachtungen sorbischer Aspekte als auch Möglichkeiten einer Thematisierung über den Deutsch-Unterricht hinaus. Dabei wird auf Möglichkeiten einer Exkursion in die historische Krabat-Region in der Lausitz eingegangen. Es folgen Texte zu ausgewählten Einzelaspekten. Zudem enthält diese Publikation eine Zusammenstellung von verschiedenen Krabat-Materialien und Hinweise auf Unterrichtsprojekte zur Anregung, weiteren Vertiefung bzw. für den eigenen Unterrichtseinsatz. KW - Sorben KW - Wenden KW - Unterricht KW - Krabat Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27315 ER - TY - BOOK A1 - Christians, Heiko A1 - Möring, Sebastian A1 - Distelmeyer, Jan A1 - Pohl, Manuela A1 - Riemer, Nathanael A1 - Ernst, Sebastian A1 - Brendel, Heiko A1 - Thiele-Schwez, Martin A1 - Czauderna, André A1 - Günzel, Stephan ED - Riemer, Nathanael ED - Möring, Sebastian T1 - Videospiele als didaktische Herausforderung T3 - DIGAREC Series N2 - Mit zunehmender Schnelligkeit etablieren sich neue Medien, Kommunikationsmittel und Kunstformen innerhalb unserer Gesellschaften. Oft sind es Jugendliche, die sich als „digital natives“ unbefangen auf diese Entwicklungen einlassen können. Der Ruf nach einem kritischen Umgang mit Medien, einer systematischen Medienerziehung und Medienbildung wird seit geraumer Zeit formuliert. Allerdings existieren bisher wenige Bemühungen die angehenden Pädagoginnen und Pädagogen mit entsprechenden Methoden, Ideen und Materialien auszustatten. Der vorliegende Band der DIGAREC Series enthält Beiträge der interdisziplinären Ringvorlesung „Videospiele als didaktische Herausforderung“, die im Sommersemester 2017 an der Philosophischen Fakultät der Universität Potsdam durchgeführt wurde. Die Beiträge machen Vorschläge zum Einsatz von Computer- und Videospielen im schulischen Unterricht und für Aktivitäten in außerschulischen Jugendeinrichtungen. Die Autorinnen und Autoren erörtern aus den jeweiligen Perspektiven ihrer Fachdisziplinen konkrete Methoden und Anwendungsmöglichkeiten anhand von ausgewählten Computerspielen. Schwerpunkt des Interesses bilden dabei Videospiele, die in erster Linie zur Unterhaltung eingesetzt werden, da der Einsatz von „Serious Games“/“Educational Games“ in jüngster Zeit schon breiter wahrgenommen wird. T3 - DIGAREC Series - 08 KW - Computerspiele KW - Bildung KW - Didaktik KW - Medien KW - Unterricht KW - computer games KW - education KW - didactics KW - media KW - teaching Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-429329 SN - 978-3-86956-467-8 SN - 1867-6219 SN - 1867-6227 IS - 08 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Comparot-Moss, Sylviane A1 - Koetting, Oliver A1 - Stettler, Michaela A1 - Edner, Christoph A1 - Graf, Alexander A1 - Weise, Sean E. A1 - Streb, Sebastian A1 - Lue, Wei-Ling A1 - MacLean, Daniel A1 - Mahlow, Sebastian A1 - Ritte, Gerhard A1 - Steup, Martin A1 - Chen, Jychian A1 - Zeeman, Samuel C. A1 - Smith, Alison M. T1 - A putative phosphatase, LSF1, is required for normal starch turnover in Arabidopsis leaves N2 - A putative phosphatase, LSF1 (for LIKE SEX4; previously PTPKIS2), is closely related in sequence and structure to STARCH-EXCESS4 (SEX4), an enzyme necessary for the removal of phosphate groups from starch polymers during starch degradation in Arabidopsis (Arabidopsis thaliana) leaves at night. We show that LSF1 is also required for starch degradation: lsf1 mutants, like sex4 mutants, have substantially more starch in their leaves than wild-type plants throughout the diurnal cycle. LSF1 is chloroplastic and is located on the surface of starch granules. lsf1 and sex4 mutants show similar, extensive changes relative to wild-type plants in the expression of sugar-sensitive genes. However, although LSF1 and SEX4 are probably both involved in the early stages of starch degradation, we show that LSF1 neither catalyzes the same reaction as SEX4 nor mediates a sequential step in the pathway. Evidence includes the contents and metabolism of phosphorylated glucans in the single mutants. The sex4 mutant accumulates soluble phospho- oligosaccharides undetectable in wild-type plants and is deficient in a starch granule-dephosphorylating activity present in wild-type plants. The lsf1 mutant displays neither of these phenotypes. The phenotype of the lsf1/sex4 double mutant also differs from that of both single mutants in several respects. We discuss the possible role of the LSF1 protein in starch degradation. Y1 - 2010 UR - http://www.plantphysiol.org/ U6 - https://doi.org/10.1104/pp.109.148981 SN - 0032-0889 ER - TY - JOUR A1 - Kunnus, Kristjan A1 - Rajkovic, Ivan A1 - Schreck, Simon A1 - Quevedo, Wilson A1 - Eckert, Sebastian A1 - Beye, Martin A1 - Suljoti, Edlira A1 - Weniger, Christian A1 - Kalus, Christian A1 - Gruebel, Sebastian A1 - Scholz, Mirko A1 - Nordlund, Dennis A1 - Zhang, Wenkai A1 - Hartsock, Robert W. A1 - Gaffney, Kelly J. A1 - Schlotter, William F. A1 - Turner, Joshua J. A1 - Kennedy, Brian A1 - Hennies, Franz A1 - Techert, Simone A1 - Wernet, Philippe A1 - Föhlisch, Alexander T1 - A setup for resonant inelastic soft x-ray scattering on liquids at free electron laser light sources JF - Review of scientific instruments : a monthly journal devoted to scientific instruments, apparatus, and techniques N2 - We present a flexible and compact experimental setup that combines an in vacuum liquid jet with an x-ray emission spectrometer to enable static and femtosecond time-resolved resonant inelastic soft x-ray scattering (RIXS) measurements from liquids at free electron laser (FEL) light sources. We demonstrate the feasibility of this type of experiments with the measurements performed at the Linac Coherent Light Source FEL facility. At the FEL we observed changes in the RIXS spectra at high peak fluences which currently sets a limit to maximum attainable count rate at FELs. The setup presented here opens up new possibilities to study the structure and dynamics in liquids. Y1 - 2012 U6 - https://doi.org/10.1063/1.4772685 SN - 0034-6748 VL - 83 IS - 12 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Giesers, Benjamin David A1 - Kamann, Sebastian A1 - Dreizler, Stefan A1 - Husser, Tim-Oliver A1 - Askar, Abbas A1 - Göttgens, Fabian A1 - Brinchmann, Jarle A1 - Latour, Marilyn A1 - Weilbacher, Peter Michael A1 - Wendt, Martin A1 - Roth, Martin M. T1 - A stellar census in globular clusters with MUSE: Binaries in NGC 3201 JF - Astronomy and astrophysics : an international weekly journal N2 - We utilise multi-epoch MUSE spectroscopy to study binary stars in the core of the Galactic globular cluster NGC 3201. Our sample consists of 3553 stars with 54 883 spectra in total comprising 3200 main-sequence stars up to 4 magnitudes below the turn-off. Each star in our sample has between 3 and 63 (with a median of 14) reliable radial velocity measurements within five years of observations. We introduce a statistical method to determine the probability of a star showing radial velocity variations based on the whole inhomogeneous radial velocity sample. Using HST photometry and an advanced dynamical MOCCA simulation of this specific cluster we overcome observational biases that previous spectroscopic studies had to deal with. This allows us to infer a binary frequency in the MUSE field of view and enables us to deduce the underlying true binary frequency of (6.75 +/- 0.72)% in NGC 3201. The comparison of the MUSE observations with the MOCCA simulation suggests a large portion of primordial binaries. We can also confirm a radial increase in the binary fraction towards the cluster centre due to mass segregation. We discovered that in the core of NGC 3201 at least (57.5 +/- 7.9)% of blue straggler stars are in a binary system. For the first time in a study of globular clusters, we were able to fit Keplerian orbits to a significant sample of 95 binaries. We present the binary system properties of eleven blue straggler stars and the connection to SX Phoenicis-type stars. We show evidence that two blue straggler formation scenarios, the mass transfer in binary (or triple) star systems and the coalescence due to binary-binary interactions, are present in our data. We also describe the binary and spectroscopic properties of four sub-subgiant (or red straggler) stars. Furthermore, we discovered two new black hole candidates with minimum masses (M sin i) of (7.68 +/- 0.50)M-circle dot, (4.4 +/- 2.8)M-circle dot, and refine the minimum mass estimate on the already published black hole to (4.53 +/- 0.21)M-circle dot, These black holes are consistent with an extensive black hole subsystem hosted by NGC 3201. KW - binaries: general KW - blue stragglers KW - stars: black holes KW - techniques: radial velocities KW - techniques: imaging spectroscopy KW - globular clusters: individual: NGC 3201 Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201936203 SN - 0004-6361 SN - 1432-0746 VL - 632 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Göttgens, Fabian A1 - Weilbacher, Peter Michael A1 - Roth, Martin M. A1 - Dreizler, Stefan A1 - Giesers, Benjamin A1 - Husser, Tim-Oliver A1 - Kamann, Sebastian A1 - Brinchmann, Jarle A1 - Kollatschny, Wolfram A1 - Monreal-Ibero, Ana A1 - Schmidt, Kasper Borello A1 - Wendt, Martin A1 - Wisotzki, Lutz A1 - Bacon, Roland T1 - Discovery of an old nova remnant in the Galactic globular cluster M 22 JF - Astronomy and astrophysics : an international weekly journal N2 - A nova is a cataclysmic event on the surface of a white dwarf in a binary system that increases the overall brightness by several orders of magnitude. Although binary systems with a white dwarf are expected to be overabundant in globular clusters compared with in the Galaxy, only two novae from Galactic globular clusters have been observed. We present the discovery of an emission nebula in the Galactic globular cluster M 22 (NGC 6656) in observations made with the integral-field spectrograph MUSE. We extracted the spectrum of the nebula and used the radial velocity determined from the emission lines to confirm that the nebula is part of NGC 6656. Emission-line ratios were used to determine the electron temperature and density. It is estimated to have a mass of 1-17 x 10(-5) M-circle dot. This mass and the emission-line ratios indicate that the nebula is a nova remnant. Its position coincides with the reported location of a "guest star", an ancient Chinese term for transients, observed in May 48 BCE. With this discovery, this nova may be one of the oldest confirmed extra-solar events recorded in human history. KW - globular clusters: individual: NGC 6656 KW - novae, cataclysmic variables KW - techniques: imaging spectroscopy Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201935221 SN - 1432-0746 VL - 626 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Kamann, Sebastian A1 - Husser, T. -O. A1 - Dreizler, S. A1 - Emsellem, E. A1 - Weilbacher, Peter Michael A1 - Martens, S. A1 - Bacon, R. A1 - den Brok, M. A1 - Giesers, B. A1 - Krajnovic, Davor A1 - Roth, Martin M. A1 - Wendt, Martin A1 - Wisotzki, Lutz T1 - A stellar census in globular clusters with MUSE BT - the contribution of rotation to cluster dynamics studied with 200 000 stars JF - Monthly notices of the Royal Astronomical Society N2 - This is the first of a series of papers presenting the results from our survey of 25 Galactic globular clusters with the MUSE integral-field spectrograph. In combination with our dedicated algorithm for source deblending, MUSE provides unique multiplex capabilities in crowded stellar fields and allows us to acquire samples of up to 20 000 stars within the half-light radius of each cluster. The present paper focuses on the analysis of the internal dynamics of 22 out of the 25 clusters, using about 500 000 spectra of 200 000 individual stars. Thanks to the large stellar samples per cluster, we are able to perform a detailed analysis of the central rotation and dispersion fields using both radial profiles and two-dimensional maps. The velocity dispersion profiles we derive show a good general agreement with existing radial velocity studies but typically reach closer to the cluster centres. By comparison with proper motion data, we derive or update the dynamical distance estimates to 14 clusters. Compared to previous dynamical distance estimates for 47 Tuc, our value is in much better agreement with other methods. We further find significant (>3 sigma) rotation in the majority (13/22) of our clusters. Our analysis seems to confirm earlier findings of a link between rotation and the ellipticities of globular clusters. In addition, we find a correlation between the strengths of internal rotation and the relaxation times of the clusters, suggesting that the central rotation fields are relics of the cluster formation that are gradually dissipated via two-body relaxation. KW - techniques: imaging spectroscopy KW - stars: kinematics and dynamics KW - globular clusters: general Y1 - 2017 U6 - https://doi.org/10.1093/mnras/stx2719 SN - 0035-8711 SN - 1365-2966 VL - 473 IS - 4 SP - 5591 EP - 5616 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Göttgens, Fabian A1 - Husser, Tim-Oliver A1 - Kamann, Sebastian A1 - Dreizler, Stefan A1 - Giesers, Benjamin A1 - Kollatschny, Wolfram A1 - Weilbacher, Peter Michael A1 - Roth, Martin M. A1 - Wendt, Martin T1 - A stellar census in globular clusters with MUSE: A spectral catalogue of emission-line sources JF - Astronomy and astrophysics : an international weekly journal N2 - Aims. Globular clusters produce many exotic stars due to a much higher frequency of dynamical interactions in their dense stellar environments. Some of these objects were observed together with several hundred thousand other stars in our MUSE survey of 26 Galactic globular clusters. Assuming that at least a few exotic stars have exotic spectra (i.e. spectra that contain emission lines), we can use this large spectroscopic data set of over a million stellar spectra as a blind survey to detect stellar exotica in globular clusters. Methods. To detect emission lines in each spectrum, we modelled the expected shape of an emission line as a Gaussian curve. This template was used for matched filtering on the di fferences between each observed 1D spectrum and its fitted spectral model. The spectra with the most significant detections of H alpha emission are checked visually and cross-matched with published catalogues. Results. We find 156 stars with H alpha emission, including several known cataclysmic variables (CV) and two new CVs, pulsating variable stars, eclipsing binary stars, the optical counterpart of a known black hole, several probable sub-subgiants and red stragglers, and 21 background emission-line galaxies. We find possible optical counterparts to 39 X-ray sources, as we detected H alpha emission in several spectra of stars that are close to known positions of Chandra X-ray sources. This spectral catalogue can be used to supplement existing or future X-ray or radio observations with spectra of potential optical counterparts to classify the sources. KW - globular clusters: general KW - stars: emission-line, Be KW - novae KW - cataclysmic variables KW - catalogs KW - techniques: imaging spectroscopy Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201936485 SN - 0004-6361 SN - 1432-0746 VL - 631 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Penone, Caterina A1 - Allan, Eric A1 - Soliveres, Santiago A1 - Felipe-Lucia, Maria R. A1 - Gossner, Martin M. A1 - Seibold, Sebastian A1 - Simons, Nadja K. A1 - Schall, Peter A1 - van der Plas, Fons A1 - Manning, Peter A1 - Manzanedo, Ruben D. A1 - Boch, Steffen A1 - Prati, Daniel A1 - Ammer, Christian A1 - Bauhus, Juergen A1 - Buscot, Francois A1 - Ehbrecht, Martin A1 - Goldmann, Kezia A1 - Jung, Kirsten A1 - Mueller, Joerg A1 - Mueller, Joerg C. A1 - Pena, Rodica A1 - Polle, Andrea A1 - Renner, Swen C. A1 - Ruess, Liliane A1 - Schoenig, Ingo A1 - Schrumpf, Marion A1 - Solly, Emily F. A1 - Tschapka, Marco A1 - Weisser, Wolfgang W. A1 - Wubet, Tesfaye A1 - Fischer, Markus T1 - Specialisation and diversity of multiple trophic groups are promoted by different forest features JF - Ecology letters N2 - While forest management strongly influences biodiversity, it remains unclear how the structural and compositional changes caused by management affect different community dimensions (e.g. richness, specialisation, abundance or completeness) and how this differs between taxa. We assessed the effects of nine forest features (representing stand structure, heterogeneity and tree composition) on thirteen above- and belowground trophic groups of plants, animals, fungi and bacteria in 150 temperate forest plots differing in their management type. Canopy cover decreased light resources, which increased community specialisation but reduced overall diversity and abundance. Features increasing resource types and diversifying microhabitats (admixing of oaks and conifers) were important and mostly affected richness. Belowground groups responded differently to those aboveground and had weaker responses to most forest features. Our results show that we need to consider forest features rather than broad management types and highlight the importance of considering several groups and community dimensions to better inform conservation. KW - biodiversity exploratories KW - dark diversity KW - forest management KW - global change KW - land-use KW - multidiversity KW - specialisation KW - temperate forests Y1 - 2018 U6 - https://doi.org/10.1111/ele.13182 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 1 SP - 170 EP - 180 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Weilbacher, Peter Michael A1 - Monreal-Ibero, Ana A1 - Verhamme, Anne A1 - Sandin, Christer A1 - Steinmetz, Matthias A1 - Kollatschny, Wolfram A1 - Krajnovic, Davor A1 - Kamann, Sebastian A1 - Roth, Martin M. A1 - Erroz-Ferrer, Santiago A1 - Marino, Raffaella Anna A1 - Maseda, Michael V. A1 - Wendt, Martin A1 - Bacon, Roland A1 - Dreizler, Stefan A1 - Richard, Johan A1 - Wisotzki, Lutz T1 - Lyman-continuum leakage as dominant source of diffuse ionized gas in the Antennae galaxy JF - Astronomy and astrophysics : an international weekly journal N2 - The Antennae galaxy (NGC 4038/39) is the closest major interacting galaxy system and is therefore often studied as a merger prototype. We present the first comprehensive integral field spectroscopic dataset of this system, observed with the MUSE instrument at the ESO VLT. We cover the two regions in this system which exhibit recent star formation: the central galaxy interaction and a region near the tip of the southern tidal tail. In these fields, we detect H II regions and diffuse ionized gas to unprecedented depth. About 15% of the ionized gas was undetected by previous observing campaigns. This newly detected faint ionized gas is visible everywhere around the central merger, and shows filamentary structure. We estimate diffuse gas fractions of about 60% in the central field and 10% in the southern region. We are able to show that the southern region contains a significantly different population of H II regions, showing fainter luminosities. By comparing H II region luminosities with the HST catalog of young star clusters in the central field, we estimate that there is enough Lyman-continuum leakage in the merger to explain the amount of diffuse ionized gas that we detect. We compare the Lyman-continuum escape fraction of each H II region against emission line ratios that are sensitive to the ionization parameter. While we find no systematic trend between these properties, the most extreme line ratios seem to be strong indicators of density bounded ionization. Extrapolating the Lyman-continuum escape fractions to the southern region, we conclude that simply from the comparison of the young stellar populations to the ionized gas there is no need to invoke other ionization mechanisms than Lyman-continuum leaking H II regions for the diffuse ionized gas in the Antennae. KW - galaxies: interactions KW - galaxies: individual: NGC 4038, NGC 4039 KW - galaxies: ISM KW - ISM: structure KW - H II regions Y1 - 2018 U6 - https://doi.org/10.1051/0004-6361/201731669 SN - 1432-0746 VL - 611 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Graae, Bente Jessen A1 - Verheyen, Kris A1 - Kolb, Annette A1 - van der Veken, Sebastian A1 - Heinken, Thilo A1 - Chabrerie, Olivier A1 - Diekmann, Martin A1 - Valtinat, Karin A1 - Zindel, Renate A1 - Karlsson, Elisabeth A1 - Ström, Lotta A1 - Decocq, Guillaume A1 - Hermy, Martin A1 - Baskin, Carol C. T1 - Germination requirements and seed mass of slow- and fast-colonizing temperate forest herbs along a latitudinal gradient N2 - Predictions on displacement of suitable habitats due to climate change suggest that plant species with poor colonization ability may be unable to move fast enough to match forecasted climate-induced changes in habitat distribution. However, studies on early Holocene plant migration show fast migration of many plant species that are poor colonizers today. We hypothesize that warmer temperatures during the early Holocene yielded higher seed quality, contributing to explaining the fast migration. We studied how the 3 seed quality variables, seed mass, germinability, and requirements for break of seed dormancy, vary for seeds of 11 forest herb species with varying colonization capacity collected along a 1400-km latitudinal gradient. Within species, seed mass showed a positive correlation with latitude, whereas germinability was more positively correlated with temperature (growing degree hours obtained at time of seed collection). Only slow-colonizing species increased germinability with temperature, whereas only fast-colonizing species increased germinability with latitude. These interactions were only detectable when analyzing germinability of the seeds, even though this trait and seed mass were correlated. The requirement for dormancy break did not correlate with latitude or temperature. The results indicate that seed development of slow colonizers may be favoured by a warmer climate, which in turn may be important for their migration capacity. Y1 - 2009 UR - http://www.bioone.org/loi/ecos U6 - https://doi.org/10.2980/16-2-3234 SN - 1195-6860 ER - TY - JOUR A1 - Husser, Tim-Oliver A1 - Kamann, Sebastian A1 - Dreizler, Stefan A1 - Wendt, Martin A1 - Wulff, Nina A1 - Bacon, Roland A1 - Wisotzki, Lutz A1 - Brinchmann, Jarle A1 - Weilbacher, Peter Michael A1 - Roth, Martin M. A1 - Monreal-Ibero, Ana T1 - MUSE crowded field 3D spectroscopy of over 12 000 stars in the globular cluster NGC 6397 I. The first comprehensive HRD of a globular cluster JF - Nucleic acids research N2 - Aims. We demonstrate the high multiplex advantage of crowded field 3D spectroscopy with the new integral field spectrograph MUSE by means of a spectroscopic analysis of more than 12 000 individual stars in the globular cluster NGC 6397. Methods. The stars are deblended with a point spread function fitting technique, using a photometric reference catalogue from HST as prior, including relative positions and brightnesses. This catalogue is also used for a first analysis of the extracted spectra, followed by an automatic in-depth analysis via a full-spectrum fitting method based on a large grid of PHOENIX spectra. Results. We analysed the largest sample so far available for a single globular cluster of 18 932 spectra from 12 307 stars in NGC 6397. We derived a mean radial velocity of v(rad) = 17.84 +/- 0.07 km s(-1) and a mean metallicity of [Fe/H] = -2.120 +/- 0.002, with the latter seemingly varying with temperature for stars on the red giant branch (RGB). We determine Teff and [Fe/H] from the spectra, and log g from HST photometry. This is the first very comprehensive Hertzsprung-Russell diagram (HRD) for a globular cluster based on the analysis of several thousands of stellar spectra, ranging from the main sequence to the tip of the RGB. Furthermore, two interesting objects were identified; one is a post-AGB star and the other is a possible millisecond-pulsar companion. KW - methods: data analysis KW - techniques: imaging spectroscopy KW - planets and satellites: fundamental parameters KW - stars: atmospheres KW - pulsars: general KW - globular clusters: individual: NGC 6397 Y1 - 2016 U6 - https://doi.org/10.1051/0004-6361/201526949 SN - 1432-0746 VL - 588 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Atsawawaranunt, Kamolphat A1 - Comas-Bru, Laia A1 - Mozhdehi, Sahar Amirnezhad A1 - Deininger, Michael A1 - Harrison, Sandy P. A1 - Baker, Andy A1 - Boyd, Meighan A1 - Kaushal, Nikita A1 - Ahmad, Syed Masood A1 - Brahim, Yassine Ait A1 - Arienzo, Monica A1 - Bajo, Petra A1 - Braun, Kerstin A1 - Burstyn, Yuval A1 - Chawchai, Sakonvan A1 - Duan, Wuhui A1 - Hatvani, Istvan Gabor A1 - Hu, Jun A1 - Kern, Zoltan A1 - Labuhn, Inga A1 - Lachniet, Matthew A1 - Lechleitner, Franziska A. A1 - Lorrey, Andrew A1 - Perez-Mejias, Carlos A1 - Pickering, Robyn A1 - Scroxton, Nick A1 - Atkinson, Tim A1 - Ayalon, Avner A1 - Baldini, James A1 - Bar-Matthews, Miriam A1 - Pablo Bernal, Juan A1 - Breitenbach, Sebastian Franz Martin A1 - Boch, Ronny A1 - Borsato, Andrea A1 - Cai, Yanjun A1 - Carolin, Stacy A1 - Cheng, Hai A1 - Columbu, Andrea A1 - Couchoud, Isabelle A1 - Cruz, Francisco A1 - Demeny, Attila A1 - Dominguez-Villar, David A1 - Dragusin, Virgil A1 - Drysdale, Russell A1 - Ersek, Vasile A1 - Finne, Martin A1 - Fleitmann, Dominik A1 - Fohlmeister, Jens Bernd A1 - Frappier, Amy A1 - Genty, Dominique A1 - Holzkamper, Steffen A1 - Hopley, Philip A1 - Kathayat, Gayatri A1 - Keenan-Jones, Duncan A1 - Koltai, Gabriella A1 - Luetscher, Marc A1 - Li, Ting-Yong A1 - Lone, Mahjoor Ahmad A1 - Markowska, Monika A1 - Mattey, Dave A1 - McDermott, Frank A1 - Moreno, Ana A1 - Moseley, Gina A1 - Nehme, Carole A1 - Novello, Valdir F. A1 - Psomiadis, David A1 - Rehfeld, Kira A1 - Ruan, Jiaoyang A1 - Sekhon, Natasha A1 - Sha, Lijuan A1 - Sholz, Denis A1 - Shopov, Yavor A1 - Smith, Andrew A1 - Strikis, Nicolas A1 - Treble, Pauline A1 - Unal-Imer, Ezgi A1 - Vaks, Anton A1 - Vansteenberge, Stef A1 - Veiga-Pires, Cristina A1 - Voarintsoa, Ny Riavo A1 - Wang, Xianfeng A1 - Wong, Corinne A1 - Wortham, Barbara A1 - Wurtzel, Jennifer A1 - Zong, Baoyun T1 - The SISAL database BT - a global resource to document oxygen and carbon isotope records from speleothems JF - Earth System Science Data N2 - Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide "out-of-sample" evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (delta O-18, delta C-13) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data. Y1 - 2018 U6 - https://doi.org/10.5194/essd-10-1687-2018 SN - 1866-3508 SN - 1866-3516 VL - 10 IS - 3 SP - 1687 EP - 1713 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Gerber, Markus A1 - Ehrbar, Janine A1 - Brand, Ralf A1 - Antoniewicz, Franziska A1 - Brand, Serge A1 - Colledge, Flora A1 - Donath, Lars A1 - Egger, Stephan T. A1 - Hatzinger, Martin A1 - Holsboer-Trachsler, Edith A1 - Imboden, Christian A1 - Schweinfurth, Nina A1 - Vetter, Stefan A1 - Ludyga, Sebastian T1 - Implicit attitudes towards exercise and physical activity behaviour among in-patients with psychiatric disorders JF - Mental Health and Physical Activity N2 - The current body of evidence suggests that in healthy participants, implicit attitudes towards physical activity explain variance in exercise behaviour beyond explicit cognitive processes. However, such relationships have not been examined in psychiatric patients, although this may contribute to a better understanding of the motivational and volitional resources needed to self-regulate their exercise behaviour. Therefore, the present cross-sectional study aimed to assess implicit attitudes towards exercise among psychiatric in-patients, and to correlate these implicit attitudes with their physical activity levels. Patients (N = 101) showing a psychiatric disorder, but no severe cognitive impairment, were directly recruited from psychiatric clinics. Their physical activity levels were assessed using both accelerometers and self-reports. Additionally, patients reported psychiatric symptoms and performed a single-target implicit association test (ST-IAT) with exercise employed as the target category. Of all patients, 39% showed a preference for exercise, whereas 13% showed an aversion towards exercise. The implicit attitudes of the remaining participants were equally strong for both concepts. Based on correlational analysis (correcting for age, sex, psychiatric symptoms severity, and ST-IAT sequence), no association was found between ST-IAT score, or self-reported and objectively assessed physical activity. Consequently, the link between exercise behaviour and implicit attitudes towards physical activity found in healthy participants could not be observed in psychiatric patients. KW - Accelerometry KW - Automatic evaluation KW - Dual mode theory KW - Physical activity Y1 - 2018 U6 - https://doi.org/10.1016/j.mhpa.2018.08.001 SN - 1755-2966 VL - 15 SP - 71 EP - 77 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Leung, Tsz Yan A1 - Leutbecher, Martin A1 - Reich, Sebastian A1 - Shepherd, Theodore G. T1 - Atmospheric Predictability: Revisiting the Inherent Finite-Time Barrier JF - Journal of the atmospheric sciences N2 - The accepted idea that there exists an inherent finite-time barrier in deterministically predicting atmospheric flows originates from Edward N. Lorenz’s 1969 work based on two-dimensional (2D) turbulence. Yet, known analytic results on the 2D Navier–Stokes (N-S) equations suggest that one can skillfully predict the 2D N-S system indefinitely far ahead should the initial-condition error become sufficiently small, thereby presenting a potential conflict with Lorenz’s theory. Aided by numerical simulations, the present work reexamines Lorenz’s model and reviews both sides of the argument, paying particular attention to the roles played by the slope of the kinetic energy spectrum. It is found that when this slope is shallower than −3, the Lipschitz continuity of analytic solutions (with respect to initial conditions) breaks down as the model resolution increases, unless the viscous range of the real system is resolved—which remains practically impossible. This breakdown leads to the inherent finite-time limit. If, on the other hand, the spectral slope is steeper than −3, then the breakdown does not occur. In this way, the apparent contradiction between the analytic results and Lorenz’s theory is reconciled. KW - Atmosphere KW - Turbulence KW - Error analysis KW - Spectral analysis KW - models KW - distribution KW - Numerical weather prediction KW - forecasting Y1 - 2019 U6 - https://doi.org/10.1175/JAS-D-19-0057.1 SN - 0022-4928 SN - 1520-0469 VL - 76 IS - 12 SP - 3883 EP - 3892 PB - American Meteorological Soc. CY - Boston ER - TY - JOUR A1 - Wade, Jessica A1 - Wood, Sebastian A1 - Collado-Fregoso, Elisa A1 - Heeney, Martin A1 - Durrant, James A1 - Kim, Ji-Seon T1 - Impact of Fullerene Intercalation on Structural and Thermal Properties of Organic Photovoltaic Blends JF - The journal of physical chemistry : C, Nanomaterials and interfaces N2 - The performance of organic photovoltaic blend devices is critically dependent on the polymer:fullerene interface. These interfaces are expected to impact the structural and thermal properties of the polymer with regards to the conjugated backbone planarity and transition temperatures during annealing/cooling processes. Here, we report the impact of fullerene intercalation on structural and thermal properties of poly(2,5-bis(3-tetradecylthiophen-2-yOthieno[3,2-b]thiophene (PBTTT), a highly stable material known to exhibit liquid crystalline behavior. We undertake a detailed systematic study of the extent of intercalation in the PBTTT:fullerene blend, considering the use of four different fullerene derivatives and also varying the loading ratios. Resonant Raman spectroscopy allows morphology in situ during controlled heating and cooling. We find that small fullerene molecules readily intercalate into PBTTT crystallites, resulting in a planarization of the polymer backbone, but high fullerene loading ratios or larger fullerenes result in nonintercalated domains. During cooling from melt, nonintercalated blend films are found to return to their original morphology and reproduce all thermal transitions on cooling with minimal hysteresis. Intercalated blend films show significant hysteresis on cooling due to the crystallized fullerene attempting to reintercalate. The strongest hysteresis is for intercalated blend films with excess fullerene loading ratio, which form a distinct nanoribbon morphology and exhibit a reduced geminate recombination rate. These results reveal that careful consideration should be taken during device fabrication, as postdeposition thermal treatments significantly impact the charge generation and recombination dynamics. Y1 - 2017 U6 - https://doi.org/10.1021/acs.jpcc.7b05893 SN - 1932-7447 VL - 121 SP - 20976 EP - 20985 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Christensen, Lise Bech A1 - Schulte-Ladbeck, R. E. A1 - Sanchez, Sebastian F. A1 - Becker, Thomas A1 - Jahnke, Knud A1 - Kelz, A. A1 - Roth, Martin M. A1 - Wisotzki, Lutz T1 - Abundances and kinematics of a candidate sub-damped Lymana galaxy toward PHL 1226 N2 - The spectrum of the quasar PHL 1226 is known to have a strong Mg II and sub-damped Lymanalpha (sub-DLA) absorption line system with N(H I) = (5 +/- 2) x 10(19) cm(-2) at z = 0.1602. Using integral field spectra from the Potsdam Multi Aperture Spectrophotometer (PMAS) we investigate a galaxy at an impact parameter of 6".4 which is most probably responsible for the absorption lines. A fainter galaxy at a similar redshift and a slightly larger distance from the QSO is known to exist, but we assume that the absorption is caused by the more nearby galaxy. From optical Balmer lines we estimate an intrinsic reddening consistent with 0, and a moderate star formation rate of 0.5 M-circle dot yr(-1) is inferred from the Ha luminosity. Using nebular emission line ratios we find a solar oxygen abundance 12 + log (O/H) = 8.7 +/- 0.1 and a solar nitrogen to oxygen abundance ratio log (N/O) = -1.0 +/- 0.2. This abundance is larger than those of all known sub-DLA systems derived from analyses of metal absorption lines in quasar spectra. On the other hand, the properties are compatible with the most metal rich galaxies responsible for strong Mg II absorption systems. These two categories can be reconciled if we assume an abundance gradient similar to local galaxies. Under that assumption we predict abundances 12 + log (O/H) = 7.1 and log (N/O) = -1.9 for the sub-DLA cloud, which is similar to high redshift DLA and sub-DLA systems. We find evidence for a rotational velocity of similar to200 km s(-1) over a length of similar to7 kpc. From the geometry and kinematics of the galaxy we estimate that the absorbing cloud does not belong to a rotating disk, but could originate in a rotating halo Y1 - 2005 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Becker, Thomas A1 - Christensen, Lise Bech A1 - Helms, Andreas A1 - Jahnke, Knud A1 - Kelz, A. A1 - Roth, Martin M. A1 - Sanchez, Sebastian F. T1 - Integral-field spectrophotometry of the quadruple QSO HE 0435-1223 : Evidence for microlensing N2 - We present the first spatially resolved spectroscopic observations of the recently discovered quadruple QSO and gravitational lens HE 0435-1223. Using the Potsdam Multi-Aperture Spectrophotometer (PMAS), we show that all four QSO components have very similar but not identical spectra. In particular, the spectral slopes of components A, B, and D are indistinguishable, implying that extinction due to dust plays no major role in the lensing galaxy. While also the emission line profiles are identical within the error bars, as expected from lensing, the equivalent widths show significant differences between components. Most likely, microlensing is responsible for this phenomenon. This is also consistent with the fact that component D, which shows the highest relative continuum level, has brightened by 0.07 mag since Dec. 2001. We find that the emission line flux ratios between the components are in better agreement with simple lens models than broad band or continuum measurements, but that the discrepancies between model and data are still unacceptably large. Finally, we present a detection of the lensing galaxy, although this is close to the limits of the data. Comparing with a model galaxy spectrum, we obtain a redshift estimate of zlens=0.44+/- 0.02. Y1 - 2003 ER - TY - JOUR A1 - Christensen, Lise Bech A1 - Sanchez, Sebastian F. A1 - Jahnke, Knud A1 - Becker, Thomas A1 - Wisotzki, Lutz A1 - Kelz, A. A1 - Popovic, L. C. A1 - Roth, Martin M. T1 - Integral field spectroscopy of extended Ly alpha emission from the DLA galaxy in Q2233+131 N2 - This paper presents observations of an extended Lyman-alpha emission nebula surrounding the galaxy responsible for the Damped Lyman-alpha Absorption (DLA) line in the spectrum of the quasar Q2233+131. With the Potsdam Multi Aperture Spectrophotometer (PMAS) we measure the properties of the extended Lyalpha emission in an area of 3" x 5" having a total line flux of (2.8 +/- 0.3) x 10(-16) erg cm(-2) s(-1), which at redshift z = 3.15 corresponds to a luminosity of (2.4(-0.2)(+0.3)) x 10(43) erg s(-1) and a size of 23 x 38 kpc. The location of the emission is spatially coincident with the previously detected DLA galaxy, but extends significantly beyond its limb. We argue that the Lya emission is likely to be caused by an outflow from the DLA galaxy, presumably powered by star formation. In the case of negligible dust extinction, the Lya luminosity indicates a star-formation rate of 19 +/- 10 M-. yr(-1) consistent with that derived from the UV continuum flux from the parent galaxy. The wind velocity indicated by the integral field spectra is of the order of several hundred km s(-1). We find no indication of emission originating in a rotating disk Y1 - 2004 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Becker, Thomas A1 - Christensen, Lise Bech A1 - Jahnke, Knud A1 - Helms, Andreas A1 - Kelz, A. A1 - Roth, Martin M. A1 - Sanchez, Sebastian F. T1 - Integral field spectrophotometry of gravitationally lensed QSOs with PMAS N2 - We present spatially resolved spectrophotometric observations of multiply imaged QSOs, using the Potsdam Multi- Aperture Spectrophotometer (PMAS), with the intention to search for spectral differences between components indicative of either microlensing or dust extinction. For the quadruple QSO HE 0435-1223 we find that the continuum shapes are indistinguishable, therefore differential extinction is negligible. The equivalent widths of the broad emission lines are however significantly different, and we argue that this is most likely due to microlensing. Contrariwise, the two components of the well-known object UM 673 have virtually identical emission line properties, but the continuum slopes differ significantly and indicate different dust extinction along both lines of sight Y1 - 2004 SN - 0004-6337 ER - TY - JOUR A1 - Christensen, Lise Bech A1 - Sanchez, Sebastian F. A1 - Jahnke, Knud A1 - Becker, Thomas A1 - Kelz, A. A1 - Wisotzki, Lutz A1 - Roth, Martin M. T1 - Integral field observations of damped Lyman-alpha galaxies N2 - We report preliminary results from a targeted investigation on quasars containing damped Lyman-alpha absorption (DLA) lines as well strong metal absorption lines, carried out with the Potsdam Multi Aperture Spectrophotometer (PMAS). We search for line-emitting objects at the same redshift as the absorption lines and close to the line of sight of the QSOs. We have observed and detected the already confirmed absorbing galaxies in Q2233+131 (Z(abs) = 3.15) and Q0151+045 (Z(abs),= 0.168), while failing to find spectral signatures for the z = 0.091 absorber in Q0738+313. From the Q2233+131 DLA galaxy, we have detected extended Lyalpha emission from an area of 3" x 5" Y1 - 2004 ER - TY - JOUR A1 - Jahnke, Knud A1 - Wisotzki, Lutz A1 - Sanchez, Sebastian F. A1 - Christensen, Lise Bech A1 - Becker, Thomas A1 - Kelz, A. A1 - Roth, Martin M. T1 - Integral field spectroscopy of QSO host galaxies N2 - We describe a project to study the state of the ISM in similar to20 low redshift (z < 0.3) QSO host galaxies observed with the PMAS integral field spectrograph. We describe the development of the method to access the stellar and gas components of the spectrum without the strong nuclear emission, in order to access the host galaxy properties in the central region. It shows that integral field spectroscopy promises to be very efficient in studying the gas distribution and its velocity field, and also the spatially resolved stellar population in the host galaxies of luminous AGN Y1 - 2004 ER - TY - JOUR A1 - Bustamante, Sebastian A1 - Sparre, Martin A1 - Springel, Volker A1 - Grand, Robert J. J. T1 - Merger-induced metallicity dilution in cosmological galaxy formation simulations JF - Monthly notices of the Royal Astronomical Society N2 - Observational studies have revealed that galaxy pairs tend to have lower gas-phase metallicity than isolated galaxies. This metallicity deficiency can be caused by inflows of low-metallicity gas due to the tidal forces and gravitational torques associated with galaxy mergers, diluting the metal content of the central region. In this work we demonstrate that such metallicity dilution occurs in state-of-the-art cosmological simulations of galaxy formation. We find that the dilution is typically 0.1 dex for major mergers, and is noticeable at projected separations smaller than 40 kpc. For minor mergers the metallicity dilution is still present, even though the amplitude is significantly smaller. Consistent with previous analysis of observed galaxies we find that mergers are outliers from the fundamental metallicity relation, with deviations being larger than expected for a Gaussian distribution of residuals. Our large sample of mergers within full cosmological simulations also makes it possible to estimate how the star formation rate enhancement and gas consumption timescale behave as a function of the merger mass ratio. We confirm that strong starbursts are likely to occur in major mergers, but they can also arise in minor mergers if more than two galaxies are participating in the interaction, a scenario that has largely been ignored in previous work based on idealised isolated merger simulations. KW - methods: numerical KW - galaxies: interactions KW - galaxies: star formation KW - galaxies: evolution Y1 - 2018 U6 - https://doi.org/10.1093/mnras/sty1692 SN - 0035-8711 SN - 1365-2966 VL - 479 IS - 3 SP - 3381 EP - 3392 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Bierbach, David A1 - Schulte, Matthias A1 - Herrmann, Nina A1 - Tobler, Michael A1 - Stadler, Stefan A1 - Jung, Christian T. A1 - Kunkel, Benjamin A1 - Riesch, Rüdiger A1 - Klaus, Sebastian A1 - Ziege, Madlen A1 - Indy, Jeane Rimber A1 - Arias-Rodriguez, Lenin A1 - Plath, Martin T1 - Predator-induced changes of female mating preferences BT - innate and experiential effects T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Background In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results In dichotomous choice tests predator-naïve (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 984 KW - sexual selection KW - female choice KW - non-independent mate choice KW - predator recognition KW - Poecilia mexicana Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431099 SN - 1866-8372 IS - 984 ER - TY - GEN A1 - Serth, Sebastian A1 - Podlesny, Nikolai A1 - Bornstein, Marvin A1 - Lindemann, Jan A1 - Latt, Johanna A1 - Selke, Jan A1 - Schlosser, Rainer A1 - Boissier, Martin A1 - Uflacker, Matthias T1 - An interactive platform to simulate dynamic pricing competition on online marketplaces T2 - 2017 IEEE 21st International Enterprise Distributed Object Computing Conference (EDOC) N2 - E-commerce marketplaces are highly dynamic with constant competition. While this competition is challenging for many merchants, it also provides plenty of opportunities, e.g., by allowing them to automatically adjust prices in order to react to changing market situations. For practitioners however, testing automated pricing strategies is time-consuming and potentially hazardously when done in production. Researchers, on the other side, struggle to study how pricing strategies interact under heavy competition. As a consequence, we built an open continuous time framework to simulate dynamic pricing competition called Price Wars. The microservice-based architecture provides a scalable platform for large competitions with dozens of merchants and a large random stream of consumers. Our platform stores each event in a distributed log. This allows to provide different performance measures enabling users to compare profit and revenue of various repricing strategies in real-time. For researchers, price trajectories are shown which ease evaluating mutual price reactions of competing strategies. Furthermore, merchants can access historical marketplace data and apply machine learning. By providing a set of customizable, artificial merchants, users can easily simulate both simple rule-based strategies as well as sophisticated data-driven strategies using demand learning to optimize their pricing strategies. Y1 - 2017 SN - 978-1-5090-3045-3 U6 - https://doi.org/10.1109/EDOC.2017.17 SN - 2325-6354 SP - 61 EP - 66 PB - Institute of Electrical and Electronics Engineers CY - New York ER - TY - JOUR A1 - Martin, Sebastian A1 - Haberland, Christian A1 - Rietbrock, Andreas T1 - Forearc decoupling of guided waves in the Chile-Peru subduction zone N2 - The structure and alterations of subducted oceanic lithosphere ( e. g., thickness and seismic velocity of oceanic crust) can be obtained by analyzing guided seismic waves generated by earthquakes within the slab (Wadati- Benioff zone). In northern Chile prominent secondary phases from intermediate-depth seismicity, observed in the forearc region can be interpreted as guided waves. For the observation of guided waves it is usually required to have stations close to the wave guide, a fact which is not directly given for forearc stations in subduction zone environments. With the help of finite difference simulations we model the decoupling mechanism of guided waves at the contact between the descending oceanic plate and the upper plate crust where the wave guide is opened due to the equalization of seismic velocities. Provided that suited stations are available, this mechanism allows for the use of intermediate depth seismicity to study the shallow subduction zone structure ( <= 100 km depth) Y1 - 2005 ER - TY - BOOK A1 - Fretzdorff, Patrick A1 - Heineck, Martin A1 - Huschner, Roland A1 - Göritz, Matthias A1 - Küpper, Stefan A1 - Moritz, Sven A1 - Schwind, Sebastian A1 - Seeger, Ulf A1 - Benning, Marc A1 - Bruch, Harald A1 - Brunnert, Jenny A1 - Hödl, Patrick A1 - Neubauer, Kati A1 - Schulze, Peggy ED - Klose, Dagmar T1 - Begegnung mit dem Fremden in Geschichtswissenschaft und Geschichtsunterricht N2 - Aus dem Inhalt: I Weltmacht gegen Großmacht – Rom und das Partherreich II Das antike Griechenland am Beispiel der olympischen Spiele III Expedition in die neue Welt IV Sorben/Wenden im Geschichtsunterricht T3 - Perspektiven historischen Denkens und Lernens - 6 Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-50250 ER - TY - THES A1 - Martin, Sebastian T1 - Subduction zone wave guides : deciphering slab structure using intraslab seismicity at the Chile-Peru subduction zone T1 - Wellenleiter in Subduktionszonen : Bestimmung der Struktur der Chile-Peru Subduktionszone mit Hilfe von intra-platten Seismizität N2 - Subduction zones are regions of intense earthquake activity up to great depth. Sources are located inside the subducting lithosphere and, as a consequence, seismic radiation from subduction zone earthquakes is strongly affected by the interior slab structure. The wave field of these intraslab events observed in the forearc region is profoundly influenced by a seismically slow layer atop the slab surface. This several kilometer thick low-velocity channel (wave guide) causes the entrapment of seismic energy producing strong guided wave phases that appear in P onsets in certain regions of the forearc. Observations at the Chile-Peru subduction zone presented here, as well as observations at several other circum-pacific subduction zones show such signals. Guided wave analysis contributes details of immense value regarding the processes near the slab surface, such as layering of subducted lithosphere, source locations of intraslab seismicity and most of all, range and manner of mineralogical phase transitions. Seismological data stem from intermediate depth events (depth range 70 km - 300 km) recorded in northern Chile near 21 Grad S during the collaborative research initiative " Deformation Processes in the Andes" (SFB 267). A subset of stations - all located within a slab-parallel transect close to 69 Grad W - show low-frequency first arrivals (2 Hz), sometimes followed by a second high-frequency phase. We employ 2-dimensional finite-difference simulations of complete P-SV wave propagation to explore the parameter space of subduction zone wave guides and explain the observations. Key processes underlying the guided wave propagation are studied: Two distinct mechanisms of decoupling of trapped energy from the wave guide are analyzed - a prerequisite to observe the phases at stations located at large distances from the wave guide (up to 100 km). Variations of guided wave effects perpendicular to the strike of the subduction zone are investigated, such as the influence of phases traveling in the fast slab. Further, the merits and limits of guided wave analysis are assessed. Frequency spectra of the guided wave onsets prove to be a robust quantity that captures guided wave characteristics at subduction zones including higher mode excitation. They facilitate the inference of wave guide structure and source positioning: The peak frequency of the guided wave fundamental mode is associated with a certain combination of layer width and velocity contrast. The excitation strength of the guided wave fundamental mode and higher modes is associated with source position and orientation relative to the low-velocity layer. The guided wave signals at the Chile-Peru subduction zone are caused by energy that leaks from the subduction zone wave guide. On the one hand, the bend shape of the slab allows for leakage at a depth of 100 km. On the other, equalization of velocities between the wave guide and the host rocks causes further energy leakage at the contact zone between continental and oceanic crust (70 km depth). Guided waves bearing information on deep slab structure can therefore be recorded at specific regions in the forearc. These regions are determined based on slab geometry, and their locations coincide with the observations. A number of strong constraints on the structure of the Chile-Peru slab are inferred: The deep wave guide for intraslab events is formed by a layer of 2 km average width that remains seismically slow (7 percent velocity reduction compared to surrounding mantle). This low-velocity layer at the top of the Chile-Peru slab is imaged from a depth of 100 km down to at least 160 km. Intermediate depth events causing the observed phases are located inside the layer or directly beneath it in the slab mantle. The layer is interpreted as partially eclogized lower oceanic crust persisting to depth beyond the volcanic arc. N2 - Subduktionszonen sind bis in große Tiefen von intensiver Erdbebentätigkeit geprägt. Die Erdbebenquellen befinden sich in der subduzierten Lithosphäre (Slab), ihr Wellenfeld wird deshalb stark von der internen Slab-Struktur beeinflusst. Eine Schicht mit reduzierter seismischer Geschwindigkeit im oberen Bereich der Platte kann als Wellenleiter für diese Signale fungieren. In der nur wenige Kilometer dicken Schicht entstehen sogenannte geführte Wellen, die in Teilen des Forearc beobachtet werden. Diese Phasen bergen wertvolle Informationen über die Struktur nahe der Slab-Oberfläche, wie zum Beispiel Dicke der Schichtung, Herdlokationen und vor allem Tiefe und Art mineralogischer Umsetzungen. Die Beobachtungen stammen von mitteltiefen Beben (70 km - 300 km) im Untersuchungsgebiet in Nord-Chile und wurden im Rahmen des Sonderforschungsbereich 267 " Deformationsprozesse in den Anden" aufgezeichnet. Stationen in einem Streifen um 69 Grad W, der sich parallel zum Streichen der Subduktionszone erstreckt, zeigen niederfrequente Ersteinsätze, denen teilweise höherfrequente Phasen folgen. Mit Hilfe eines 2-dimensionalen Finite-Differenzen-Algorithmus werden die P-SV Wellenausbreitung simuliert, und die Beobachtungen erklärt. Zentrale Fragestellungen zu Wellenleitern in Subduktionszonen werden untersucht: Es werden zwei Mechanismen, die das Auskoppeln seismischer Energie aus dem Wellenleiter ermöglichen beschrieben - eine Grundvoraussetzung für das Auftreten von geführten Wellen in großen Entfernungen vom Wellenleiter (bis zu 100 km). Des weiteren werden Stärken und Grenzen der Analyse von geführten Wellen erörtert. Die Spektren der geführten Wellenzüge erweisen sich als robuste Messgröße, um die Charakteristika des Wellenleiters zu bestimmt. Struktur des Wellenleiters und Quellpositionen können so für festgelegte Quell-Empfänger-Geometrien abgeleitet werden. Die Peak-Frequenz der Grundmode wird durch eine Kombination aus Dicke der Schicht und Geschwindigkeitskontrast bestimmt. Die Stärke der Anregung der Grundmode und höherer Moden lässt auf die Lage und Orientierung der Erdbebenquelle relativ zur Schicht schließen. Geschwindigkeitskontrast, Schichtdicke und Quellposition sind von herausragender Bedeutung, um mineralogische Interpretationen des Wellenleiters zu überprüfen. Aufbauend auf die Simulationen werden die Beobachtungen interpretiert und Auskunft über die Struktur der Chile-Peru Subduktionszone erhalten: Eine dünne Schicht an der Slab-Oberfläche (durchschnittlich 2 km dick) trägt geringere seismische Geschwindigkeiten als der umgebende Mantel und fungiert als Wellenleiter für intra-platten Ereignisse in Tiefen von 100 bis mindestens 160 km. Ereignisse, die geführte Wellen hervorrufen, liegen in dieser Schicht oder direkt darunter im subduzierten Mantel. Um zu den Stationen in der Forearc-Region zu gelangen, entkoppelt ein Teil der geführten Wellen in einer Tiefe von circa 100 km aus der Niedergeschwindigkeitsschicht. Die Krümmung des Slab erlaubt das Austreten der Wellen und nimmt auch Einfluss auf die Pulsformen. Der Wellenleiter in der Chile-Peru Subduktionszone ergibt sich als unregelmäßige Schicht mit reduzierter seismischer Geschwindigkeit, in der geführte Wellen entstehen, in unterschiedlichen Tiefen wieder austreten, und an die freie Oberfläche gelangen. Die Beobachtungsgebiete befinden sich im Forearc und werden durch die Geometrie und Struktur der subduzierten Platte festgelegt. Die nur wenige Kilometer dicke, seismisch langsame Schicht an der Oberfläche des Chile-Peru Slab legt nahe, dass die Unterkruste der subduzierten Platte bis in große Tiefen besteht und nicht vollständig eklogitisiert ist. Abgeleitete Schichtdicke, Geschwindigkeitskontrast KW - Anden KW - Subduktion KW - Wellenleiter KW - Erdbeben KW - ozeanische Kruste KW - Gabbro-Eklogit KW - Transformation KW - geführte Wellen KW - subduction KW - guided waves KW - oceanic crust KW - Andes KW - finite difference simulation Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-5820 ER - TY - JOUR A1 - Gebser, Martin A1 - Kaminski, Roland A1 - Kaufmann, Benjamin A1 - Lühne, Patrick A1 - Obermeier, Philipp A1 - Ostrowski, Max A1 - Romero Davila, Javier A1 - Schaub, Torsten H. A1 - Schellhorn, Sebastian A1 - Wanko, Philipp T1 - The Potsdam Answer Set Solving Collection 5.0 JF - Künstliche Intelligenz N2 - The Potsdam answer set solving collection, or Potassco for short, bundles various tools implementing and/or applying answer set programming. The article at hand succeeds an earlier description of the Potassco project published in Gebser et al. (AI Commun 24(2):107-124, 2011). Hence, we concentrate in what follows on the major features of the most recent, fifth generation of the ASP system clingo and highlight some recent resulting application systems. Y1 - 2018 U6 - https://doi.org/10.1007/s13218-018-0528-x SN - 0933-1875 SN - 1610-1987 VL - 32 IS - 2-3 SP - 181 EP - 182 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Keller, Sebastian A1 - Kunze, Cindy A1 - Bommer, Martin A1 - Paetz, Christian A1 - Menezes, Riya C. A1 - Svatos, Ales A1 - Dobbek, Holger A1 - Schubert, Torsten T1 - Selective Utilization of Benzimidazolyl-Norcobamides as Cofactors by the Tetrachloroethene Reductive Dehalogenase of Sulfurospirillum multivorans JF - Journal of bacteriology N2 - The organohalide-respiring bacterium Sulfurospirillum multivorans produces a unique cobamide, namely, norpseudo-B-12, which serves as cofactor of the tetrachloroethene (PCE) reductive dehalogenase (PceA). As previously reported, a replacement of the adeninyl moiety, the lower base of the cofactor, by exogenously applied 5,6-dimethylbenzimidazole led to inactive PceA. To explore the general effect of benzimidazoles on the PCE metabolism, the susceptibility of the organism for guided biosynthesis of various singly substituted benzimidazolyl-norcobamides was investigated, and their use as cofactor by PceA was analyzed. Exogenously applied 5-methylbenzimidazole (5-MeBza), 5-hydroxybenzimidazole (5-OHBza), and 5-methoxybenzimidazole (5-OMeBza) were found to be efficiently incorporated as lower bases into norcobamides (NCbas). Structural analysis of the NCbas by nuclear magnetic resonance spectroscopy uncovered a regioselectivity in the utilization of these precursors for NCba biosynthesis. When 5-MeBza was added, a mixture of 5-MeBza-norcobamide and 6-MeBza-norcobamide was formed, and the PceA enzyme activity was affected. In the presence of 5-OHBza, almost exclusively 6-OHBza-norcobamide was produced, while in the presence of 5-OMeBza, predominantly 5-OMeBza-norcobamide was detected. Both NCbas were incorporated into PceA, and no negative effect on the PceA activity was observed. In crystal structures of PceA, both NCbas were bound in the base-off mode with the 6-OHBza and 5-OMeBza lower bases accommodated by the same solvent-exposed hydrophilic pocket that harbors the adenine as the lower base of authentic norpseudo-B-12. In this study, a selective production of different norcobamide isomers containing singly substituted benzimidazoles as lower bases is shown, and unique structural insights into their utilization as co-factors by a cobamide-containing enzyme are provided. IMPORTANCE Guided biosynthesis of norcobamides containing singly substituted benzimidazoles as lower bases by the organohalide-respiring epsilonproteobacterium Sulfurospirillum multivorans is reported. An unprecedented specificity in the formation of norcobamide isomers containing hydroxylated or methoxylated benzimidazoles was observed that implicated a strict regioselectivity of the norcobamide biosynthesis in the organism. In contrast to 5,6-dimethylbenzimidazolyl-norcobamide, the incorporation of singly substituted benzimidazolyl-norcobamides as a cofactor into the tetrachloroethene reductive dehalogenase was not impaired. The enzyme was found to be functional with different isomers and not limited to the use of adeninyl-norcobamide. Structural analysis of the enzyme equipped with either adeninyl-or benzimidazolyl-norcobamide cofactors visualized for the first time structurally different cobamides bound in base-off conformation to the cofactor-binding site of a cobamide-containing enzyme. KW - benzimidazoles KW - corrinoid-containing enzymes KW - reductive dehalogenase KW - vitamin B-12 Y1 - 2018 U6 - https://doi.org/10.1128/JB.00584-17 SN - 0021-9193 SN - 1098-5530 VL - 200 IS - 8 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Kiefer, Thomas A1 - Völler, Heinz A1 - Nothroff, Jörg A1 - Schikora, Martin A1 - von Podewils, Sebastian A1 - Sicher, Claudia A1 - Bartels-Reinisch, Birgit A1 - Heyne, Karolin A1 - Haase, Hermann A1 - Jünger, Michael A1 - Daeschlein, Georg T1 - Multiresistente Erreger in der onkologischen und kardiologischen Rehabilitation T1 - Multiresistant Pathogens in Oncological and Cardiological Rehabilitation - Results of a Surveillance Study in Brandenburg BT - Ergebnisse einer Surveillancestudie in Brandenburg JF - Die Rehabilitation : Zeitschrift für Praxis und Forschung in der Rehabilitation N2 - In der vorliegenden Studie wurde die Prävalenz der Besiedlung mit multiresistenten Keimen an 155 Patienten aus der onkologischen und 157 Patienten aus der kardiologischen Rehabilitation mittels mikrobiologischen Screenings untersucht. Dabei zeigten 4,5% der onkologischen und 4,5% der kardiologischen Rehabilitationspatienten eine Besiedlung mit multiresistenten Erregern. Am häufigsten wurden 2-MRGN und ESBL (2,9%) nachgewiesen. Onkologische Rehapatienten zeigten doppelt so hohe Prävalenzraten für 3-MRGN im Vergleich zu kardiologischen (2,6 und 1,3%). Insgesamt zeigen onkologische und kardiologische Rehabilitationspatienten vergleichsweise niedrige Prävalenzraten für multiresistente Krankenhauskeime. N2 - We investigated the prevalence of multidrug resistant pathogens in patients of oncologic and cardiologic rehabilitation units with 155 oncologic and 157 cardiologic patients undergoing microbiologic screening. It was found that 4.5 % of oncologic as well as cardiologic patients were colonized with multidrug resistant pathogens. 2-MRGN and ESBL were the most encountered species (2.9 %). 3-MRGN were found twice as frequent in oncologic patients (2.6 and 1.3 %). Overall oncologic and cardiologic patients exhibit comparatively low prevalence rates for multidrug resistant pathogens. KW - Oncologic cardiologic rehabilitation KW - multiresistant bacteria KW - Onkologische kardiologische Rehabilitation KW - multiresistente Erreger Y1 - 2019 U6 - https://doi.org/10.1055/a-0638-9226 SN - 0034-3536 SN - 1439-1309 VL - 58 IS - 2 SP - 136 EP - 142 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Chang, Dan A1 - Knapp, Michael A1 - Enk, Jacob A1 - Lippold, Sebastian A1 - Kircher, Martin A1 - Lister, Adrian M. A1 - MacPhee, Ross D. E. A1 - Widga, Christopher A1 - Czechowski, Paul A1 - Sommer, Robert A1 - Hodges, Emily A1 - Stümpel, Nikolaus A1 - Barnes, Ian A1 - Dalén, Love A1 - Derevianko, Anatoly A1 - Germonpré, Mietje A1 - Hillebrand-Voiculescu, Alexandra A1 - Constantin, Silviu A1 - Kuznetsova, Tatyana A1 - Mol, Dick A1 - Rathgeber, Thomas A1 - Rosendahl, Wilfried A1 - Tikhonov, Alexey N. A1 - Willerslev, Eske A1 - Hannon, Greg A1 - Lalueza i Fox, Carles A1 - Joger, Ulrich A1 - Poinar, Hendrik N. A1 - Hofreiter, Michael A1 - Shapiro, Beth T1 - The evolutionary and phylogeographic history of woolly mammoths BT - a comprehensive mitogenomic analysis JF - Scientific reports N2 - Near the end of the Pleistocene epoch, populations of the woolly mammoth (Mammuthus primigenius) were distributed across parts of three continents, from western Europe and northern Asia through Beringia to the Atlantic seaboard of North America. Nonetheless, questions about the connectivity and temporal continuity of mammoth populations and species remain unanswered. We use a combination of targeted enrichment and high-throughput sequencing to assemble and interpret a data set of 143 mammoth mitochondrial genomes, sampled from fossils recovered from across their Holarctic range. Our dataset includes 54 previously unpublished mitochondrial genomes and significantly increases the coverage of the Eurasian range of the species. The resulting global phylogeny confirms that the Late Pleistocene mammoth population comprised three distinct mitochondrial lineages that began to diverge ~1.0–2.0 million years ago (Ma). We also find that mammoth mitochondrial lineages were strongly geographically partitioned throughout the Pleistocene. In combination, our genetic results and the pattern of morphological variation in time and space suggest that male-mediated gene flow, rather than large-scale dispersals, was important in the Pleistocene evolutionary history of mammoths. Y1 - 2017 U6 - https://doi.org/10.1038/srep44585 SN - 2045-2322 VL - 7 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Middeldorp, Christel M. A1 - Mahajan, Anubha A1 - Horikoshi, Momoko A1 - Robertson, Neil R. A1 - Beaumont, Robin N. A1 - Bradfield, Jonathan P. A1 - Bustamante, Mariona A1 - Cousminer, Diana L. A1 - Day, Felix R. A1 - De Silva, N. Maneka A1 - Guxens, Monica A1 - Mook-Kanamori, Dennis O. A1 - St Pourcain, Beate A1 - Warrington, Nicole M. A1 - Adair, Linda S. A1 - Ahlqvist, Emma A1 - Ahluwalia, Tarunveer Singh A1 - Almgren, Peter A1 - Ang, Wei A1 - Atalay, Mustafa A1 - Auvinen, Juha A1 - Bartels, Meike A1 - Beckmann, Jacques S. A1 - Bilbao, Jose Ramon A1 - Bond, Tom A1 - Borja, Judith B. A1 - Cavadino, Alana A1 - Charoen, Pimphen A1 - Chen, Zhanghua A1 - Coin, Lachlan A1 - Cooper, Cyrus A1 - Curtin, John A. A1 - Custovic, Adnan A1 - Das, Shikta A1 - Davies, Gareth E. A1 - Dedoussis, George V. A1 - Duijts, Liesbeth A1 - Eastwood, Peter R. A1 - Eliasen, Anders U. A1 - Elliott, Paul A1 - Eriksson, Johan G. A1 - Estivill, Xavier A1 - Fadista, Joao A1 - Fedko, Iryna O. A1 - Frayling, Timothy M. A1 - Gaillard, Romy A1 - Gauderman, W. James A1 - Geller, Frank A1 - Gilliland, Frank A1 - Gilsanz, Vincente A1 - Granell, Raquel A1 - Grarup, Niels A1 - Groop, Leif A1 - Hadley, Dexter A1 - Hakonarson, Hakon A1 - Hansen, Torben A1 - Hartman, Catharina A. A1 - Hattersley, Andrew T. A1 - Hayes, M. Geoffrey A1 - Hebebrand, Johannes A1 - Heinrich, Joachim A1 - Helgeland, Oyvind A1 - Henders, Anjali K. A1 - Henderson, John A1 - Henriksen, Tine B. A1 - Hirschhorn, Joel N. A1 - Hivert, Marie-France A1 - Hocher, Berthold A1 - Holloway, John W. A1 - Holt, Patrick A1 - Hottenga, Jouke-Jan A1 - Hypponen, Elina A1 - Iniguez, Carmen A1 - Johansson, Stefan A1 - Jugessur, Astanand A1 - Kahonen, Mika A1 - Kalkwarf, Heidi J. A1 - Kaprio, Jaakko A1 - Karhunen, Ville A1 - Kemp, John P. A1 - Kerkhof, Marjan A1 - Koppelman, Gerard H. A1 - Korner, Antje A1 - Kotecha, Sailesh A1 - Kreiner-Moller, Eskil A1 - Kulohoma, Benard A1 - Kumar, Ashish A1 - Kutalik, Zoltan A1 - Lahti, Jari A1 - Lappe, Joan M. A1 - Larsson, Henrik A1 - Lehtimaki, Terho A1 - Lewin, Alexandra M. A1 - Li, Jin A1 - Lichtenstein, Paul A1 - Lindgren, Cecilia M. A1 - Lindi, Virpi A1 - Linneberg, Allan A1 - Liu, Xueping A1 - Liu, Jun A1 - Lowe, William L. A1 - Lundstrom, Sebastian A1 - Lyytikainen, Leo-Pekka A1 - Ma, Ronald C. W. A1 - Mace, Aurelien A1 - Magi, Reedik A1 - Magnus, Per A1 - Mamun, Abdullah A. A1 - Mannikko, Minna A1 - Martin, Nicholas G. A1 - Mbarek, Hamdi A1 - McCarthy, Nina S. A1 - Medland, Sarah E. A1 - Melbye, Mads A1 - Melen, Erik A1 - Mohlke, Karen L. A1 - Monnereau, Claire A1 - Morgen, Camilla S. A1 - Morris, Andrew P. A1 - Murray, Jeffrey C. A1 - Myhre, Ronny A1 - Najman, Jackob M. A1 - Nivard, Michel G. A1 - Nohr, Ellen A. A1 - Nolte, Ilja M. A1 - Ntalla, Ioanna A1 - Oberfield, Sharon E. A1 - Oken, Emily A1 - Oldehinkel, Albertine J. A1 - Pahkala, Katja A1 - Palviainen, Teemu A1 - Panoutsopoulou, Kalliope A1 - Pedersen, Oluf A1 - Pennell, Craig E. A1 - Pershagen, Goran A1 - Pitkanen, Niina A1 - Plomin, Robert A1 - Power, Christine A1 - Prasad, Rashmi B. A1 - Prokopenko, Inga A1 - Pulkkinen, Lea A1 - Raikkonen, Katri A1 - Raitakari, Olli T. A1 - Reynolds, Rebecca M. A1 - Richmond, Rebecca C. A1 - Rivadeneira, Fernando A1 - Rodriguez, Alina A1 - Rose, Richard J. A1 - Salem, Rany A1 - Santa-Marina, Loreto A1 - Saw, Seang-Mei A1 - Schnurr, Theresia M. A1 - Scott, James G. A1 - Selzam, Saskia A1 - Shepherd, John A. A1 - Simpson, Angela A1 - Skotte, Line A1 - Sleiman, Patrick M. A. A1 - Snieder, Harold A1 - Sorensen, Thorkild I. A. A1 - Standl, Marie A1 - Steegers, Eric A. P. A1 - Strachan, David P. A1 - Straker, Leon A1 - Strandberg, Timo A1 - Taylor, Michelle A1 - Teo, Yik-Ying A1 - Thiering, Elisabeth A1 - Torrent, Maties A1 - Tyrrell, Jessica A1 - Uitterlinden, Andre G. A1 - van Beijsterveldt, Toos A1 - van der Most, Peter J. A1 - van Duijn, Cornelia M. A1 - Viikari, Jorma A1 - Vilor-Tejedor, Natalia A1 - Vogelezang, Suzanne A1 - Vonk, Judith M. A1 - Vrijkotte, Tanja G. M. A1 - Vuoksimaa, Eero A1 - Wang, Carol A. A1 - Watkins, William J. A1 - Wichmann, H-Erich A1 - Willemsen, Gonneke A1 - Williams, Gail M. A1 - Wilson, James F. A1 - Wray, Naomi R. A1 - Xu, Shujing A1 - Xu, Cheng-Jian A1 - Yaghootkar, Hanieh A1 - Yi, Lu A1 - Zafarmand, Mohammad Hadi A1 - Zeggini, Eleftheria A1 - Zemel, Babette S. A1 - Hinney, Anke A1 - Lakka, Timo A. A1 - Whitehouse, Andrew J. O. A1 - Sunyer, Jordi A1 - Widen, Elisabeth E. A1 - Feenstra, Bjarke A1 - Sebert, Sylvain A1 - Jacobsson, Bo A1 - Njolstad, Pal R. A1 - Stoltenberg, Camilla A1 - Smith, George Davey A1 - Lawlor, Debbie A. A1 - Paternoster, Lavinia A1 - Timpson, Nicholas J. A1 - Ong, Ken K. A1 - Bisgaard, Hans A1 - Bonnelykke, Klaus A1 - Jaddoe, Vincent W. V. A1 - Tiemeier, Henning A1 - Jarvelin, Marjo-Riitta A1 - Evans, David M. A1 - Perry, John R. B. A1 - Grant, Struan F. A. A1 - Boomsma, Dorret I. A1 - Freathy, Rachel M. A1 - McCarthy, Mark I. A1 - Felix, Janine F. T1 - The Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia BT - design, results and future prospects JF - European journal of epidemiology N2 - The impact of many unfavorable childhood traits or diseases, such as low birth weight and mental disorders, is not limited to childhood and adolescence, as they are also associated with poor outcomes in adulthood, such as cardiovascular disease. Insight into the genetic etiology of childhood and adolescent traits and disorders may therefore provide new perspectives, not only on how to improve wellbeing during childhood, but also how to prevent later adverse outcomes. To achieve the sample sizes required for genetic research, the Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia were established. The majority of the participating cohorts are longitudinal population-based samples, but other cohorts with data on early childhood phenotypes are also involved. Cohorts often have a broad focus and collect(ed) data on various somatic and psychiatric traits as well as environmental factors. Genetic variants have been successfully identified for multiple traits, for example, birth weight, atopic dermatitis, childhood BMI, allergic sensitization, and pubertal growth. Furthermore, the results have shown that genetic factors also partly underlie the association with adult traits. As sample sizes are still increasing, it is expected that future analyses will identify additional variants. This, in combination with the development of innovative statistical methods, will provide detailed insight on the mechanisms underlying the transition from childhood to adult disorders. Both consortia welcome new collaborations. Policies and contact details are available from the corresponding authors of this manuscript and/or the consortium websites. KW - Genetics KW - Consortium KW - Childhood traits and disorders KW - Longitudinal Y1 - 2019 U6 - https://doi.org/10.1007/s10654-019-00502-9 SN - 0393-2990 SN - 1573-7284 VL - 34 IS - 3 SP - 279 EP - 300 PB - Springer CY - Dordrecht ER - TY - BOOK A1 - Weiß, Norman A1 - Mehde, Veith A1 - Krieger, Heike A1 - Franzen, Martin A1 - Mock, Sebastian A1 - Altenhain, Karsten ED - Weiß, Norman T1 - Rechtsentwicklungen im vereinten Deutschland T3 - Potsdamer Studien zu Staat, Recht und Politik N2 - Der Band enthält die Vorträge einer Konferenz vom November 2009 in Potsdam. Die Texte untersuchen anhand ausgewählter Beispiele die Entwicklungen der zurückliegenden zwanzig Jahre im Zivilrecht, Strafrecht und öffentlichen Recht. Die Bundesrepublik Deutschland sieht sich seit der Wiedervereinigung und dem Ende des Kalten Krieges in einer ganz neuen Situation. Dies gilt für den völkerrechtlichen Rahmen ihrer Außenpolitik, für den Wettbewerb der Rechtsordnungen, für die mit erhöhter Dynamik fortschreitende europäische Einigung und ihre Konsequenzen. Die bei der Grundrechtsinterpretation im Mehrebenensystem auftauchenden Divergenzen und die Auswirkungen technischer Neuerungen auf das Sozialverhalten prägen Rechtswirklichkeit und Rechtsdogmatik. T3 - Potsdamer Studien zu Staat, Recht und Politik - 3 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-36180 SN - 978-3-86956-018-2 SN - 1867-2663 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Fettke, Jörg A1 - Albrecht, Tanja A1 - Hejazi, Mahdi A1 - Mahlow, Sebastian A1 - Nakamura, Yasunori A1 - Steup, Martin T1 - Glucose 1-phosphate is efficiently taken up by potato (Solanum tuberosum) tuber parenchyma cells and converted to reserve starch granules N2 - Reserve starch is an important plant product but the actual biosynthetic process is not yet fully understood. Potato (Solanum tuberosum) tuber discs from various transgenic plants were used to analyse the conversion of external sugars or sugar derivatives to starch. By using in vitro assays, a direct glucosyl transfer from glucose 1-phosphate to native starch granules as mediated by recombinant plastidial phosphorylase was analysed. Compared with labelled glucose, glucose 6-phosphate or sucrose, tuber discs converted externally supplied [C-14] glucose 1-phosphate into starch at a much higher rate. Likewise, tuber discs from transgenic lines with a strongly reduced expression of cytosolic phosphoglucomutase, phosphorylase or transglucosidase converted glucose 1-phosphate to starch with the same or even an increased rate compared with the wild-type. Similar results were obtained with transgenic potato lines possessing a strongly reduced activity of both the cytosolic and the plastidial phosphoglucomutase. Starch labelling was, however, significantly diminished in transgenic lines, with a reduced concentration of the plastidial phosphorylase isozymes. Two distinct paths of reserve starch biosynthesis are proposed that explain, at a biochemical level, the phenotype of several transgenic plant lines. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0028-646X U6 - https://doi.org/10.1111/j.1469-8137.2009.03126.x SN - 0028-646X ER - TY - JOUR A1 - Ritte, Gerhard A1 - Heydenreich, Matthias A1 - Mahlow, Sebastian A1 - Haebel, Sophie A1 - Koetting, Oliver A1 - Steup, Martin T1 - Phosphorylation of C6- and C3-positions of glucosyl residues in starch is catalysed by distinct dikinases JF - FEBS letters : the journal for rapid publication of short reports in molecular biosciences N2 - Glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) are required for normal starch metabolism. We analysed starch phosphorylation in Arabidopsis wildtype plants and mutants lacking either GWD or PWD using P-31 NMR. Phosphorylation at both C6- and C3-positions of glucose moieties in starch was drastically decreased in GWD-deficient mutants. In starch from PWD-deficient plants C3-bound phosphate was reduced to levels close to the detection limit. The latter result contrasts with previous reports according to which GWD phosphorylates both C6- and C3-positions. In these studies, phosphorylation had been analysed by HPLC of acid-hydrolysed glucans. We now show that maltose-6-phosphate, a product of incomplete starch hydrolysis, co-eluted with glucose-3-phosphate under the chromatographic conditions applied. Re-examination of the specificity of the dikinases using an improved method demonstrates that C6- and C3-phosphorylation is selectively catalysed by GWD and PWD, respectively. KW - starch phosphorylation KW - GWD KW - PWD KW - P-31 NMR Y1 - 2006 U6 - https://doi.org/10.1016/j.febslet.2006.07.085 SN - 0014-5793 VL - 580 IS - 20 SP - 4872 EP - 4876 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Heinze, Johannes A1 - Simons, Nadja K. A1 - Seibold, Sebastian A1 - Wacker, Alexander A1 - Weithoff, Guntram A1 - Gossner, Martin M. A1 - Prati, Daniel A1 - Bezemer, T. Martijn A1 - Joshi, Jasmin Radha T1 - The relative importance of plant-soil feedbacks for plant-species performance increases with decreasing intensity of herbivory JF - Oecologia N2 - Under natural conditions, aboveground herbivory and plant-soil feedbacks (PSFs) are omnipresent interactions strongly affecting individual plant performance. While recent research revealed that aboveground insect herbivory generally impacts the outcome of PSFs, no study tested to what extent the intensity of herbivory affects the outcome. This, however, is essential to estimate the contribution of PSFs to plant performance under natural conditions in the field. Here, we tested PSF effects both with and without exposure to aboveground herbivory for four common grass species in nine grasslands that formed a gradient of aboveground invertebrate herbivory. Without aboveground herbivores, PSFs for each of the four grass species were similar in each of the nine grasslands-both in direction and in magnitude. In the presence of herbivores, however, the PSFs differed from those measured under herbivory exclusion, and depended on the intensity of herbivory. At low levels of herbivory, PSFs were similar in the presence and absence of herbivores, but differed at high herbivory levels. While PSFs without herbivores remained similar along the gradient of herbivory intensity, increasing herbivory intensity mostly resulted in neutral PSFs in the presence of herbivores. This suggests that the relative importance of PSFs for plant-species performance in grassland communities decreases with increasing intensity of herbivory. Hence, PSFs might be more important for plant performance in ecosystems with low herbivore pressure than in ecosystems with large impacts of insect herbivores. KW - Plant-soil feedback KW - Herbivorous insects KW - Field conditions KW - Selective herbivory KW - Nutritional quality Y1 - 2019 U6 - https://doi.org/10.1007/s00442-019-04442-9 SN - 0029-8549 SN - 1432-1939 VL - 190 IS - 3 SP - 651 EP - 664 PB - Springer CY - New York ER - TY - GEN A1 - Wicha, Sebastian G. A1 - Kees, Martin G. A1 - Solms, Alexander Maximilian A1 - Minichmayr, Iris K. A1 - Kratzer, Alexander A1 - Kloft, Charlotte T1 - TDMx: A novel web-based open-access support tool for optimising antimicrobial dosing regimens in clinical routine T2 - International journal of antimicrobial agents Y1 - 2015 U6 - https://doi.org/10.1016/j.ijantimicag.2014.12.010 SN - 0924-8579 SN - 1872-7913 VL - 45 IS - 4 SP - 442 EP - 444 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Pohlenz, Philipp A1 - Schubarth, Wilfried A1 - Speck, Karsten A1 - Seidel, Andreas A1 - Winter, Martin A1 - Heine, Christoph A1 - Kleinfeld, Merle A1 - Sarrar, Lea A1 - Gemsa, Charlotte A1 - Wendland, Mirko A1 - Schlumm, Katharina A1 - Lehmann, Uta A1 - Kummerow, Udo A1 - Bastian, Laura A1 - Kamm, Caroline A1 - Niproschke, Saskia A1 - Sochadse, Lascha A1 - Kotzur, Katharina A1 - Hebert, Sebastian A1 - Voigt, Frank A1 - Kopp, Andrea ED - Schubarth, Wilfried ED - Speck, Karsten ED - Seidel, Andreas T1 - Nach Bologna: Praktika im Studium – Pflicht oder Kür? T1 - Beyond Bologna: internship in studies – obligation or option? BT - Empirische Analysen und Empfehlungen für die Hochschulpraxis BT - Empirical analysis and recommendations on the praxis of higher education N2 - Mit dem vorliegenden Band „Nach Bologna: Praktika im Studium – Pflicht oder Kür? Empirische Analysen und Empfehlungen für die Hochschulpraxis“ von Wilfried Schubarth, Karsten Speck und Andreas Seidel wird die Reihe „Potsdamer Beiträge zur Lehrevaluation“ unter neuem Titel und veränderter inhaltlicher Schwerpunktsetzung fortgeführt. Die Umbenennung in „Potsdamer Beiträge zur Hochschulforschung“ versteht sich als ein Schritt hin zu einer thematischen Öffnung der Reihe für die verschiedensten Felder der Hochschulforschung. Der vorliegende Band widmet sich einem der zentralen Reformziele von Bologna: der Frage des Praxis- und Berufsbezugs und dabei insbesondere den Praxisphasen im Studium. Mit der Bologna-Reform werden im bildungspolitischen Bereich sehr vielfältige strukturelle und inhaltliche Ziele verfolgt. Das Ziel dieses Bandes besteht deshalb darin, empirische Forschungen zu Praxisbezügen und Praxisphasen im Studium vorzustellen, diese in den Kontext aktueller Debatten um Studienqualität und Studienreform zu stellen sowie Folgerungen für die Gestaltung von Praxisphasen abzuleiten. Inhaltliche Schwerpunkte bilden das BMBF-Forschungsprojekt ProPrax und die Praxisphasen im Lehramtsstudium. Die Beiträge dieses Bandes gehen aus einem gleichnamigen Workshop hervor, der am 1. Oktober 2010 in Potsdam stattfand. N2 - The present conference volume „Beyond Bologna: Internship in studies – obligation or option? Empirical analysis and recommendations on the praxis of higher education“ by Wilfried Schubarth, Karsten Speck and Andreas Seidel is part of the serial “Potsdamer Beiträge zur Lehrevaluation” which is actually renamed as “Potsdamer Beiträge zur Hochschulforschung“. The new title supports modified focal points for research and provides opportunities for several fields of higher education research. The volume focuses on the practical relevance and the development of professional skills in academic studies as one of the central intentions of the Bologna Process. This Reform involves a variety of structural and content-related intentions in the field of educational policy. The aim of this conference volume is therefore to present empirical research with regard to practical relevance and internship in academic studies. It is linked to the current debate concerning quality of academic studies as well as the higher education reform in general and draws conclusions for the practical implementation of academic internships. The ProPrax research project, founded by the BMBF, and its first results as well as internships in teacher education are main issues of this volume. The contributions result from the correspondent Potsdam conference on October 1st 2010. T3 - Potsdamer Beiträge zur Hochschulforschung - 1 KW - Bologna-Prozess KW - Hochschulforschung KW - Lehrerbildung KW - Praxisphasen KW - Kompetenzentwicklung KW - Studienqualität KW - Bologna Process KW - higher education research KW - teacher education KW - internships KW - competence development KW - quality of academic studies Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-51033 SN - 978-3-86956-123-3 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schütt, Heiko Herbert A1 - Rothkegel, Lars Oliver Martin A1 - Trukenbrod, Hans Arne A1 - Reich, Sebastian A1 - Wichmann, Felix A. A1 - Engbert, Ralf T1 - Likelihood-based parameter estimation and comparison of dynamical cognitive models JF - Psychological Review N2 - Dynamical models of cognition play an increasingly important role in driving theoretical and experimental research in psychology. Therefore, parameter estimation, model analysis and comparison of dynamical models are of essential importance. In this article, we propose a maximum likelihood approach for model analysis in a fully dynamical framework that includes time-ordered experimental data. Our methods can be applied to dynamical models for the prediction of discrete behavior (e.g., movement onsets); in particular, we use a dynamical model of saccade generation in scene viewing as a case study for our approach. For this model, the likelihood function can be computed directly by numerical simulation, which enables more efficient parameter estimation including Bayesian inference to obtain reliable estimates and corresponding credible intervals. Using hierarchical models inference is even possible for individual observers. Furthermore, our likelihood approach can be used to compare different models. In our example, the dynamical framework is shown to outperform nondynamical statistical models. Additionally, the likelihood based evaluation differentiates model variants, which produced indistinguishable predictions on hitherto used statistics. Our results indicate that the likelihood approach is a promising framework for dynamical cognitive models. KW - likelihood KW - model fitting KW - dynamical model KW - eye movements KW - model comparison Y1 - 2017 U6 - https://doi.org/10.1037/rev0000068 SN - 0033-295X SN - 1939-1471 VL - 124 IS - 4 SP - 505 EP - 524 PB - American Psychological Association CY - Washington ER - TY - JOUR A1 - Koenig, Julian A1 - Abler, Birgit A1 - Agartz, Ingrid A1 - akerstedt, Torbjorn A1 - Andreassen, Ole A. A1 - Anthony, Mia A1 - Baer, Karl-Juergen A1 - Bertsch, Katja A1 - Brown, Rebecca C. A1 - Brunner, Romuald A1 - Carnevali, Luca A1 - Critchley, Hugo D. A1 - Cullen, Kathryn R. A1 - de Geus, Eco J. C. A1 - de la Cruz, Feliberto A1 - Dziobek, Isabel A1 - Ferger, Marc D. A1 - Fischer, Hakan A1 - Flor, Herta A1 - Gaebler, Michael A1 - Gianaros, Peter J. A1 - Giummarra, Melita J. A1 - Greening, Steven G. A1 - Guendelman, Simon A1 - Heathers, James A. J. A1 - Herpertz, Sabine C. A1 - Hu, Mandy X. A1 - Jentschke, Sebastian A1 - Kaess, Michael A1 - Kaufmann, Tobias A1 - Klimes-Dougan, Bonnie A1 - Koelsch, Stefan A1 - Krauch, Marlene A1 - Kumral, Deniz A1 - Lamers, Femke A1 - Lee, Tae-Ho A1 - Lekander, Mats A1 - Lin, Feng A1 - Lotze, Martin A1 - Makovac, Elena A1 - Mancini, Matteo A1 - Mancke, Falk A1 - Mansson, Kristoffer N. T. A1 - Manuck, Stephen B. A1 - Mather, Mara A1 - Meeten, Frances A1 - Min, Jungwon A1 - Mueller, Bryon A1 - Muench, Vera A1 - Nees, Frauke A1 - Nga, Lin A1 - Nilsonne, Gustav A1 - Ordonez Acuna, Daniela A1 - Osnes, Berge A1 - Ottaviani, Cristina A1 - Penninx, Brenda W. J. H. A1 - Ponzio, Allison A1 - Poudel, Govinda R. A1 - Reinelt, Janis A1 - Ren, Ping A1 - Sakaki, Michiko A1 - Schumann, Andy A1 - Sorensen, Lin A1 - Specht, Karsten A1 - Straub, Joana A1 - Tamm, Sandra A1 - Thai, Michelle A1 - Thayer, Julian F. A1 - Ubani, Benjamin A1 - van Der Mee, Denise J. A1 - van Velzen, Laura S. A1 - Ventura-Bort, Carlos A1 - Villringer, Arno A1 - Watson, David R. A1 - Wei, Luqing A1 - Wendt, Julia A1 - Schreiner, Melinda Westlund A1 - Westlye, Lars T. A1 - Weymar, Mathias A1 - Winkelmann, Tobias A1 - Wu, Guo-Rong A1 - Yoo, Hyun Joo A1 - Quintana, Daniel S. T1 - Cortical thickness and resting-state cardiac function across the lifespan BT - a cross-sectional pooled mega-analysis JF - Psychophysiology : journal of the Society for Psychophysiological Research N2 - Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research. KW - aging KW - autonomic nervous system KW - cortical thickness KW - heart rate KW - heart KW - rate variability KW - sex Y1 - 2020 U6 - https://doi.org/10.1111/psyp.13688 SN - 0048-5772 SN - 1469-8986 VL - 58 IS - 7 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Leung, Tsz Yan A1 - Leutbecher, Martin A1 - Reich, Sebastian A1 - Shepherd, Theodore G. T1 - Impact of the mesoscale range on error growth and the limits to atmospheric predictability JF - Journal of the atmospheric sciences N2 - Global numerical weather prediction (NWP) models have begun to resolve the mesoscale k(-5/3) range of the energy spectrum, which is known to impose an inherently finite range of deterministic predictability per se as errors develop more rapidly on these scales than on the larger scales. However, the dynamics of these errors under the influence of the synoptic-scale k(-3) range is little studied. Within a perfect-model context, the present work examines the error growth behavior under such a hybrid spectrum in Lorenz's original model of 1969, and in a series of identical-twin perturbation experiments using an idealized two-dimensional barotropic turbulence model at a range of resolutions. With the typical resolution of today's global NWP ensembles, error growth remains largely uniform across scales. The theoretically expected fast error growth characteristic of a k(-5/3) spectrum is seen to be largely suppressed in the first decade of the mesoscale range by the synoptic-scale k(-3) range. However, it emerges once models become fully able to resolve features on something like a 20-km scale, which corresponds to a grid resolution on the order of a few kilometers. KW - mesoscale forecasting KW - numerical weather prediction/forecasting KW - short-range prediction KW - numerical analysis/modeling Y1 - 2020 U6 - https://doi.org/10.1175/JAS-D-19-0346.1 SN - 0022-4928 SN - 1520-0469 VL - 77 IS - 11 SP - 3769 EP - 3779 PB - American Meteorological Soc. CY - Boston ER - TY - JOUR A1 - Walter, Juliane K. A1 - Rückert, Christine A1 - Voss, Martin A1 - Müller, Sebastian L. A1 - Piontek, Joerg A1 - Gast, Klaus A1 - Blasig, Ingolf E. T1 - The oligomerization of the coiled coil-domain of occluddin is redox sensitive N2 - The transmembrane tight junction protein occludin is sensitive to oxidative stress. Occludin oligomerizes; however, its function in the tight junction is unknown. The cytosolic C-terminal tail contains a coiled coil-domain and forms dimers contributing to the oligomerization. The regulation of the oligomerization remains unclear. As the domain area contains sulfhydryl residues, we tested the hypothesis that the dimerization of the coiled coil-domain depends on these residues. We showed that the dimerization is modulated by the thiol concentration in the low-millimolar range, which is relevant both for physiological and pathophysiological conditions. Masking the sulfhydryl residues in the fragment by covalent binding of 4-vinyl pyridine prevented the dimerization but did not affect its helical structure and cylindric shape. The data demonstrate, for the first time, that disulfide bridge formation of murine cystein 408 is involved in the dimerization. This process is redox-sensitive but the secondary structure of the domain is not. It is concluded that the dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0077-8923 U6 - https://doi.org/10.1111/j.1749-6632.2009.04058.x SN - 0077-8923 ER - TY - JOUR A1 - Litwinski, Christian A1 - Tannert, Sebastian A1 - Jesorka, Aldo A1 - Katterle, Martin A1 - Roder, Beate T1 - Photophysical properties of gallium hydroxyl tetratolylporphyrin and 13(2)-demethoxycarbonyl-(gallium hydroxyl)- methyl-pheophorbide alpha N2 - Two metal tetrapyrroles containing gallium, gallium hydroxyl tetratolylporphyrin and 13(2)-demethoxycarbonyl- (gallium hydroxyl)methyl pheophorbide a (Ga-(OH)-chlorin), were synthesized from their respective free bases using Ga(III)-acetylacetonate in a phenol melt. Their photophysical properties were investigated and the quantum yields of different monomolecular deactivation processes were determined. For Ga-(OH)-porphyrin S-2-fluorescence was observed and quantified. In contrast. for Ga-(OH)-chlorin no S-2-fluorescence was observed. Both compounds should be useful as efficient photosensitizers in photodynamic therapy. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/00092614 U6 - https://doi.org/10.1016/j.cplett.2005.10.131 SN - 0009-2614 ER - TY - JOUR A1 - Monreal-Ibero, Ana A1 - Weilbacher, Peter Michael A1 - Wendt, Martin A1 - Selman, Fernando A1 - Lallement, Rosine A1 - Brinchmann, Jarle A1 - Kamann, Sebastian A1 - Sandin, Christer T1 - Towards DIB mapping in galaxies beyond 100 Mpc A radial profile of the lambda 5780.5 diffuse interstellar band in AM1353-272 B JF - Astronomy and astrophysics : an international weekly journal N2 - Context. Diffuse interstellar bands (DIBs) are non-stellar weak absorption features of unknown origin found in the spectra of stars viewed through one or several clouds of the interstellar medium (ISM). Research of DIBs outside the Milky Way is currently very limited. In particular, spatially resolved investigations of DIBs outside of the Local Group are, to our knowledge, inexistent. Aims. In this contribution, we explore the capability of the high-sensitivity integral field spectrograph, MUSE, as a tool for mapping diffuse interstellar bands at distances larger than 100 Mpc. Methods. We used MUSE commissioning data for AM1353-272 B, the member with the highest extinction of the Dentist's Chair, an interacting system of two spiral galaxies. High signal-to-noise spectra were created by co-adding the signal of many spatial elements distributed in a geometry of concentric elliptical half-rings. Results. We derived decreasing radial profiles for the equivalent width of the lambda 5780.5 DIB both in the receding and approaching side of the companion galaxy up to distances of similar to 4.6 kpc from the centre of the galaxy. The interstellar extinction as derived from the Ha/H beta line ratio displays a similar trend, with decreasing values towards the external parts. This translates into an intrinsic correlation between the strength of the DIB and the extinction within AM1353-272 B, consistent with the currently existing global trend between these quantities when using measurements for Galactic and extragalactic sightlines. Conclusions. It seems feasible to map the DIB strength in the Local Universe, which has up to now only been performed for the Milky Way. This offers a new approach to studying the relationship between DIBs and other characteristics and species of the ISM in addition to using galaxies in the Local Group or sightlines towards very bright targets outside the Local Group. KW - dust, extinction KW - ISM: lines and bands KW - galaxies: ISM KW - galaxies: individual: AM1353-272 B Y1 - 2015 U6 - https://doi.org/10.1051/0004-6361/201525854 SN - 0004-6361 SN - 1432-0746 VL - 576 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Bierbach, David A1 - Schulte, Matthias A1 - Herrmann, Nina A1 - Tobler, Michael A1 - Stadler, Stefan A1 - Jung, Christian T. A1 - Kunkel, Benjamin A1 - Riesch, Rüdiger A1 - Klaus, Sebastian A1 - Ziege, Madlen A1 - Rimber Indy, Jeane A1 - Arias-Rodriguez, Lenin A1 - Plath, Martin T1 - Predator-induced changes of female mating preferences innate and experiential effects JF - BMC evolutionary biology N2 - Background: In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results: In dichotomous choice tests predator-naive (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions: Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators. KW - Sexual selection KW - female choice KW - non-independent mate choice KW - predator recognition KW - Poecilia mexicana Y1 - 2011 U6 - https://doi.org/10.1186/1471-2148-11-190 SN - 1471-2148 VL - 11 IS - 3-4 PB - BioMed Central CY - London ER - TY - JOUR A1 - Weilbacher, Peter Michael A1 - Monreal-Ibero, Ana A1 - Kollatschny, Wolfram A1 - Ginsburg, Adam A1 - McLeod, Anna F. A1 - Kamann, Sebastian A1 - Sandin, Christer A1 - Palsa, Ralf A1 - Wisotzki, Lutz A1 - Bacon, Roland A1 - Selman, Fernando A1 - Brinchmann, Jarle A1 - Caruana, Joseph A1 - Kelz, Andreas A1 - Martinsson, Thomas A1 - Pecontal-Rousset, Arlette A1 - Richard, Johan A1 - Wendt, Martin T1 - A MUSE map of the central Orion Nebula (M 42) JF - Astronomy and astrophysics : an international weekly journal N2 - We present a new integral field spectroscopic dataset of the central part of the Orion Nebula (M 42), observed with the MUSE instrument at the ESO VLT. We reduced the data with the public MUSE pipeline. The output products are two FITS cubes with a spatial size of similar to 5'9 x 4'9 (corresponding to similar to 0.76 x 0.63 pc(2)) and a contiguous wavelength coverage of 4595 ... 9366 angstrom, spatially sampled at 0 ''.2. We provide two versions with a sampling of 1.25 angstrom and 0.85 angstrom in dispersion direction. Together with variance cubes these files have a size of 75 and 110 GiB on disk. They are the largest integral field mosaics to date in terms of information content. We make them available for use in the community. To validate this dataset, we compare world coordinates, reconstructed magnitudes, velocities, and absolute and relative emission line fluxes to the literature values and find excellent agreement. We derive a 2D map of extinction and present de-reddened flux maps of several individual emission lines and of diagnostic line ratios. We estimate physical properties of the Orion Nebula, using the emission line ratios [N II] and [S III] (for the electron temperature T-e) and [S II] and [Cl III] (for the electron density N-e), and show 2D images of the velocity measured from several bright emission lines. KW - H II regions KW - ISM: individual objects: M 42 KW - open clusters and associations: individual: Trapezium cluster Y1 - 2015 U6 - https://doi.org/10.1051/0004-6361/201526529 SN - 1432-0746 VL - 582 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Kunnus, Kristjan A1 - Josefsson, Ida A1 - Rajkovic, Ivan A1 - Schreck, Simon A1 - Quevedo, Wilson A1 - Beye, Martin A1 - Grübel, Sebastian A1 - Scholz, Mirko A1 - Nordlund, Dennis A1 - Zhang, Wenkai A1 - Hartsock, Robert W. A1 - Gaffney, Kelly J. A1 - Schlotter, William F. A1 - Turner, Joshua J. A1 - Kennedy, Brian A1 - Hennies, Franz A1 - Techert, Simone A1 - Wernet, Philippe A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Anti-Stokes resonant x-ray Raman scattering for atom specific and excited state selective dynamics JF - NEW JOURNAL OF PHYSICS N2 - Ultrafast electronic and structural dynamics of matter govern rate and selectivity of chemical reactions, as well as phase transitions and efficient switching in functional materials. Since x-rays determine electronic and structural properties with elemental, chemical, orbital and magnetic selectivity, short pulse x-ray sources have become central enablers of ultrafast science. Despite of these strengths, ultrafast x-rays have been poor at picking up excited state moieties from the unexcited ones. With time-resolved anti-Stokes resonant x-ray Raman scattering (AS-RXRS) performed at the LCLS, and ab initio theory we establish background free excited state selectivity in addition to the elemental, chemical, orbital and magnetic selectivity of x-rays. This unparalleled selectivity extracts low concentration excited state species along the pathway of photo induced ligand exchange of Fe(CO)(5) in ethanol. Conceptually a full theoretical treatment of all accessible insights to excited state dynamics with AS-RXRS with transform-limited x-ray pulses is given-which will be covered experimentally by upcoming transform-limited x-ray sources. KW - ultrafast photochemistry KW - excited state selectivity KW - anti-Stokes resonant x-ray raman scattering KW - free electron lasers KW - resonant inelastic x-ray scattering Y1 - 2016 U6 - https://doi.org/10.1088/1367-2630/18/10/103011 SN - 1367-2630 VL - 18 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Wendt, Martin A1 - Husser, Tim-Oliver A1 - Kamann, Sebastian A1 - Monreal-Ibero, Ana A1 - Richter, Philipp A1 - Brinchmann, Jarle A1 - Dreizler, Stefan A1 - Weilbacher, Peter Michael A1 - Wisotzki, Lutz T1 - Mapping diffuse interstellar bands in the local ISM on small scales via MUSE 3D spectroscopy A pilot study based on globular cluster NGC 6397 JF - Astronomy and astrophysics : an international weekly journal N2 - Context. We map the interstellar medium (ISM) including the diffuse interstellar bands (DIBs) in absorption toward the globular cluster NGC6397 using VLT/MUSE. Assuming the absorbers are located at the rim of the Local Bubble we trace structures on the order of mpc (milliparsec, a few thousand AU). Aims. We aimed to demonstrate the feasibility to map variations of DIBs on small scales with MUSE. The sightlines defined by binned stellar spectra are separated by only a few arcseconds and we probe the absorption within a physically connected region. Methods. This analysis utilized the fitting residuals of individual stellar spectra of NGC6397 member stars and analyzed lines from neutral species and several DIBs in Voronoi-binned composite spectra with high signal-to-noise ratio (S/N). Results. This pilot study demonstrates the power of MUSE for mapping the local ISM on very small scales which provides a new window for ISM observations. We detect small scale variations in Na-I and K-I as well as in several DIBs within few arcseconds, or mpc with regard to the Local Bubble. We verify the suitability of the MUSE 3D spectrograph for such measurements and gain new insights by probing a single physical absorber with multiple sight lines. KW - techniques: imaging spectroscopy KW - globular clusters: individual: NGC 6397 KW - dust, extinction KW - ISM: structure KW - ISM: lines and bands Y1 - 2017 U6 - https://doi.org/10.1051/0004-6361/201629816 SN - 1432-0746 VL - 607 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Köslin-Findeklee, Fabian A1 - Rizi, Vajiheh Safavi A1 - Becker, Martin A. A1 - Parra-Londono, Sebastian A1 - Arif, Muhammad A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Kunze, Reinhard A1 - Horst, Walter J. T1 - Transcriptomic analysis of nitrogen starvation- and cultivar-specific leaf senescence in winter oilseed rape (Brassica napus L.) JF - Plant science : an international journal of experimental plant biology N2 - High nitrogen (N) efficiency, characterized by high grain yield under N limitation, is an important agricultural trait in Brassica napus L. cultivars related to delayed senescence of older leaves during reproductive growth (a syndrome called stay-green). The aim of this study was thus to identify genes whose expression is specifically altered during N starvation-induced leaf senescence and that can be used as markers to distinguish cultivars at early stages of senescence prior to chlorophyll loss. To this end, the transcriptomes of leaves of two B. napus cultivars differing in stay-green characteristics and N efficiency were analyzed 4 days after the induction of senescence by either N starvation, leaf shading or detaching. In addition to N metabolism genes, N starvation mostly (and specifically) repressed genes related to photosynthesis, photorespiration and cell-wall structure, while genes related to mitochondrial electron transport and flavonoid biosynthesis were predominately up-regulated. A kinetic study over a period of 12 days with four B. napus cultivars differing in their stay-green characteristics confirmed the cultivar-specific regulation of six genes in agreement with their senescence behavior: the senescence regulator ANAC029, the anthocyanin synthesis-related genes ANS and DFR-like1, the ammonium transporter AMT1:4, the ureide transporter UPSS, and SPS1 involved in sucrose biosynthesis. The identified genes represent markers for the detection of cultivar-specific differences in N starvation-induced leaf senescence and can thus be employed as valuable tools in B. napus breeding. (C) 2015 Elsevier Ireland Ltd. All rights reserved. KW - Brassica napus KW - Genotypic differences KW - Leaf senescence KW - Molecular marker KW - N efficiency KW - Stay-green Y1 - 2015 U6 - https://doi.org/10.1016/j.plantsci.2014.11.018 SN - 0168-9452 VL - 233 SP - 174 EP - 185 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Mondal, Suvendu Sekhar A1 - Hovestadt, Maximilian A1 - Dey, Subarna A1 - Paula, Carolin A1 - Glomb, Sebastian A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Janiak, Christoph A1 - Hartmann, Martin A1 - Holdt, Hans-Jürgen T1 - Synthesis of a partially fluorinated ZIF-8 analog for ethane/ethene separation JF - CrystEngComm N2 - The separation of ethane/ethene mixtures (as well as other paraffin/olefin mixtures) is one of the most important but challenging processes in the petrochemical industry. In this work, we report the synthesis of ZIF-318, isostructural to ZIF-8 but built from the mixed linkers of 2-methylimidazole (L1) and 2-trifluoromethylimidazole (L2) (ZIF-318 = [(Zn(L1)(L2)](n)). The synthesis has been optimized to proceed without ZnO-formation. Using only the L2 linker under solvothermal conditions afforded ZnO-embedded in the H-bonded and non-porous coordination polymer ZnO@[Zn-2(L2)(2)(HCOO)(OH)](n). The slight differences in the size of the substituents (-CH3 vs. -CF3) possibly in combination with different electronic inductive effects led to small but significant changes to the pore size and properties respectively, though the effective pore opening (aperture) size of ZIF-318 remained the same in comparison with ZIF-8. ZIF-318 is chemically (boiling water, methanol, benzene, and wide pH range at room temperature for 1 day), thermally (up to 310 degrees C) stable, and more hydrophobic than ZIF-8 which is proven by contact angle measurement. ZIF-318 can be activated for N-2, CO2, CH4, H-2, ethane, ethane, propane, and propene gases sorptions. Consequently, in breakthrough experiments, the ethane/ethene mixtures can be separated. Y1 - 2017 U6 - https://doi.org/10.1039/c7ce01438d SN - 1466-8033 VL - 19 SP - 5882 EP - 5891 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Schmidt, Roland A1 - Hagen, Sebastian A1 - Brete, Daniel A1 - Carley, Robert A1 - Gahl, Cornelius A1 - Dokic, Jadranka A1 - Saalfrank, Peter A1 - Hecht, Stefan A1 - Tegeder, Petra A1 - Weinelt, Martin T1 - On the electronic and geometrical structure of the trans- and cis-isomer of tetra-tert-butyl-azobenzene on Au(111) N2 - Near edge X-ray absorption. ne structure and X-ray photoelectron spectroscopy have been employed to follow the reversible trans to cis isomerization of tetra-tert-butyl-azobenzene (TBA) adsorbed on Au(111). For one monolayer the molecules adopt an adsorption geometry characteristic of the trans-TBA isomer. The azo-bridge (N = N) is aligned nearly parallel to the surface and the phenyl rings exhibit a planar orientation with a small tilt angle <= 4 degrees with respect to the surface normal. Illumination of the molecular layer at 455 nm triggers the trans to cis isomerization which is associated with a pronounced change of the geometrical and electronic structure. The N1s to pi* transition of the central azo-bridge shifts by 0.45 +/- 0.05 eV to higher photon energy and the transition dipole moment (TDM) is tilted by 59 +/- 5 degrees with respect to the surface normal. The pi-system of one phenyl ring is tilted by about 30 degrees with respect to the surface normal, while the second ring plane is oriented nearly perpendicular to the surface. This reorientation is supported by a shift and broadening of the C-H resonances associated with the tert-butyl legs of the molecule. These findings support a configuration of the photo-switched TBA molecule on Au(111) which is comparable to the cis-isomer of the free molecule. In the photo-stationary state 53 +/- 5% of the TBA molecules are switched to the cis configuration. Thermal activation induces the back reaction to trans-TBA. Y1 - 2010 UR - http://pubs.rsc.org/en/content/articlehtml/2010/cp/b924409c U6 - https://doi.org/10.1039/B924409c SN - 1463-9076 ER - TY - JOUR A1 - Leung, Tsz Yan A1 - Leutbecher, Martin A1 - Reich, Sebastian A1 - Shepherd, Theodore G. T1 - Forecast verification BT - relating deterministic and probabilistic metrics JF - Quarterly journal of the Royal Meteorological Society N2 - The philosophy of forecast verification is rather different between deterministic and probabilistic verification metrics: generally speaking, deterministic metrics measure differences, whereas probabilistic metrics assess reliability and sharpness of predictive distributions. This article considers the root-mean-square error (RMSE), which can be seen as a deterministic metric, and the probabilistic metric Continuous Ranked Probability Score (CRPS), and demonstrates that under certain conditions, the CRPS can be mathematically expressed in terms of the RMSE when these metrics are aggregated. One of the required conditions is the normality of distributions. The other condition is that, while the forecast ensemble need not be calibrated, any bias or over/underdispersion cannot depend on the forecast distribution itself. Under these conditions, the CRPS is a fraction of the RMSE, and this fraction depends only on the heteroscedasticity of the ensemble spread and the measures of calibration. The derived CRPS-RMSE relationship for the case of perfect ensemble reliability is tested on simulations of idealised two-dimensional barotropic turbulence. Results suggest that the relationship holds approximately despite the normality condition not being met. KW - CRPS KW - ensembles KW - idealised turbulence KW - NWP KW - RMSE KW - verification Y1 - 2021 U6 - https://doi.org/10.1002/qj.4120 SN - 0035-9009 SN - 1477-870X VL - 147 IS - 739 SP - 3124 EP - 3134 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Laroque, Sophie A1 - Reifarth, Martin A1 - Sperling, Marcel A1 - Kersting, Sebastian A1 - Kloepzig, Stefanie A1 - Budach, Patrick A1 - Hartlieb, Matthias A1 - Storsberg, Joachim T1 - Impact of multivalence and self-assembly in the design of polymeric antimicrobial peptide mimics JF - ACS applied materials & interfaces N2 - Antimicrobial resistance is an increasingly serious challenge for public health and could result in dramatic negative consequences for the health care sector during the next decades. To solve this problem, antibacterial materials that are unsusceptible toward the development of bacterial resistance are a promising branch of research. In this work, a new type of polymeric antimicrobial peptide mimic featuring a bottlebrush architecture is developed, using a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and ring-opening metathesis polymerization (ROMP). This approach enables multivalent presentation of antimicrobial subunits resulting in improved bioactivity and an increased hemocompatibility, boosting the selectivity of these materials for bacterial cells. Direct probing of membrane integrity of treated bacteria revealed highly potent membrane disruption caused by bottlebrush copolymers. Multivalent bottlebrush copolymers clearly outperformed their linear equivalents regarding bioactivity and selectivity. The effect of segmentation of cationic and hydrophobic subunits within bottle brushes was probed using heterograft copolymers. These materials were found to self-assemble under physiological conditions, which reduced their antibacterial activity, highlighting the importance of precise structural control for such applications. To the best of our knowledge, this is the first example to demonstrate the positive impact of multivalence, generated by a bottlebrush topology in polymeric antimicrobial peptide mimics, making these polymers a highly promising material platform for the design of new bactericidal systems. KW - RAFT polymerization KW - ROMP KW - antimicrobial polymers KW - antimicrobial peptide KW - mimics KW - bottlebrush copolymers Y1 - 2020 U6 - https://doi.org/10.1021/acsami.0c05944 SN - 1944-8244 SN - 1944-8252 VL - 12 IS - 27 SP - 30052 EP - 30065 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Sellberg, Jonas A. A1 - McQueen, Trevor A. A1 - Laksmono, Hartawan A1 - Schreck, Simon A1 - Beye, Martin A1 - DePonte, Daniel P. A1 - Kennedy, Brian A1 - Nordlund, Dennis A1 - Sierra, Raymond G. A1 - Schlesinger, Daniel A1 - Tokushima, Takashi A1 - Zhovtobriukh, Iurii A1 - Eckert, Sebastian A1 - Segtnan, Vegard H. A1 - Ogasawara, Hirohito A1 - Kubicek, Katharina A1 - Techert, Simone A1 - Bergmann, Uwe A1 - Dakovski, Georgi L. A1 - Schlotter, William F. A1 - Harada, Yoshihisa A1 - Bogan, Michael J. A1 - Wernet, Philippe A1 - Föhlisch, Alexander A1 - Pettersson, Lars G. M. A1 - Nilsson, Anders T1 - X-ray emission spectroscopy of bulk liquid water in "no-man's land" JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - The structure of bulk liquid water was recently probed by x-ray scattering below the temperature limit of homogeneous nucleation (T-H) of similar to 232 K [J. A. Sellberg et al., Nature 510, 381-384 (2014)]. Here, we utilize a similar approach to study the structure of bulk liquid water below T-H using oxygen K-edge x-ray emission spectroscopy (XES). Based on previous XES experiments [T. Tokushima et al., Chem. Phys. Lett. 460, 387-400 (2008)] at higher temperatures, we expected the ratio of the 1b(1)' and 1b(1)" peaks associated with the lone-pair orbital in water to change strongly upon deep supercooling as the coordination of the hydrogen (H-) bonds becomes tetrahedral. In contrast, we observed only minor changes in the lone-pair spectral region, challenging an interpretation in terms of two interconverting species. A number of alternative hypotheses to explain the results are put forward and discussed. Although the spectra can be explained by various contributions from these hypotheses, we here emphasize the interpretation that the line shape of each component changes dramatically when approaching lower temperatures, where, in particular, the peak assigned to the proposed disordered component would become more symmetrical as vibrational interference becomes more important. (C) 2015 AIP Publishing LLC. Y1 - 2015 U6 - https://doi.org/10.1063/1.4905603 SN - 0021-9606 SN - 1089-7690 VL - 142 IS - 4 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Eckert, Sebastian A1 - Norell, Jesper A1 - Miedema, Piter S. A1 - Beye, Martin A1 - Fondell, Mattis A1 - Quevedo, Wilson A1 - Kennedy, Brian A1 - Hantschmann, Markus A1 - Pietzsch, Annette A1 - van Kuiken, Benjamin A1 - Ross, Matthew A1 - Minitti, Michael P. A1 - Moeller, Stefan P. A1 - Schlotter, William F. A1 - Khalil, Munira A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Untersuchung unabhängiger N‐H‐ und N‐C‐Bindungsverformungen auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung JF - Angewandte Chemie N2 - Die Femtosekundendynamik nach resonanten Photoanregungen mit optischen und Röntgenpulsen ermöglicht eine selektive Verformung von chemischen N‐H‐ und N‐C‐Bindungen in 2‐Thiopyridon in wässriger Lösung. Die Untersuchung der orbitalspezifischen elektronischen Struktur und ihrer Dynamik auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung an der N1s‐Resonanz am Synchrotron und dem Freie‐Elektronen‐Laser LCLS in Kombination mit quantenchemischen Multikonfigurationsberechnungen erbringen den direkten Nachweis dieser kontrollierten photoinduzierten Molekülverformungen und ihrer ultrakurzen Zeitskala. KW - Photochemie KW - Protonierung KW - RIXS (resonante inelastische Röntgenstreuung) KW - Selektiver Bindungsbruch KW - Stickstoff Y1 - 2017 U6 - https://doi.org/10.1002/ange.201700239 SN - 1521-3757 SN - 1521-3773 VL - 129 IS - 22 SP - 6184 EP - 6188 ER - TY - JOUR A1 - Eckert, Sebastian A1 - Norell, Jesper A1 - Miedema, Piter S. A1 - Beye, Martin A1 - Fondell, Mattis A1 - Quevedo, Wilson A1 - Kennedy, Brian A1 - Hantschmann, Markus A1 - Pietzsch, Annette A1 - Van Kuiken, Benjamin E. A1 - Ross, Matthew A1 - Minitti, Michael P. A1 - Moeller, Stefan P. A1 - Schlotter, William F. A1 - Khalil, Munira A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Ultrafast Independent N-H and N-C Bond Deformation Investigated with Resonant Inelastic X-Ray Scattering JF - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition N2 - The femtosecond excited-state dynamics following resonant photoexcitation enable the selective deformation of N-H and N-C chemical bonds in 2-thiopyridone in aqueous solution with optical or X-ray pulses. In combination with multiconfigurational quantum-chemical calculations, the orbital-specific electronic structure and its ultrafast dynamics accessed with resonant inelastic X-ray scattering at the N 1s level using synchrotron radiation and the soft X-ray free-electron laser LCLS provide direct evidence for this controlled photoinduced molecular deformation and its ultrashort time-scale. KW - nitrogen KW - photochemistry KW - protonation KW - RIXS (resonant inelastic X-ray scattering) KW - selective bond cleavage Y1 - 2017 U6 - https://doi.org/10.1002/anie.201700239 SN - 1433-7851 SN - 1521-3773 VL - 56 SP - 6088 EP - 6092 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Eckert, Sebastian A1 - Niskanen, Johannes A1 - Jay, Raphael Martin A1 - Miedema, Piter S. A1 - Fondell, Mattis A1 - Kennedy, Brian A1 - Quevedo, Wilson A1 - Iannuzzi, Marcella A1 - Föhlisch, Alexander T1 - Valence orbitals and local bond dynamics around N atoms of histidine under X-ray irradiation JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - The valence orbitals of aqueous histidine under basic, neutral and acidic conditions and their X-ray induced transformations have been monitored through N 1s resonant inelastic X-ray scattering. Using density functional ab initio molecular dynamics simulations in the core-hole state within the Z + 1 approximation, core-excitation-induced molecular transformations are quantified. Spectroscopic evidence for a highly directional X-ray-induced local N-H dissociation within the scattering duration is presented for acidic histidine. Our report demonstrates a protonation-state and chemical-environment dependent propensity for a molecular dissociation, which is induced by the absorption of high energy photons. This case study indicates that structural deformations in biomolecules under exposure to ionizing radiation, yielding possible alteration or loss of function, is highly dependent on the physiological state of the molecule upon irradiation. Y1 - 2017 U6 - https://doi.org/10.1039/c7cp05713j SN - 1463-9076 SN - 1463-9084 VL - 19 SP - 32091 EP - 32098 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Eckert, Sebastian A1 - Miedema, P. S. A1 - Quevedo, W. A1 - Fondell, Mattis A1 - Beye, Martin A1 - Pietzsch, Annette A1 - Ross, M. A1 - Khalil, M. A1 - Föhlisch, Alexander T1 - Molecular structures and protonation state of 2-Mercaptopyridine in aqueous solution JF - Chemical physics letters N2 - The speciation of 2-Mercaptopyridine in aqueous solution has been investigated with nitrogen 1s Near Edge X-ray Absorption Fine Structure spectroscopy and time dependent Density Functional Theory. The prevalence of distinct species as a function of the solvent basicity is established. No indications of dimerization towards high concentrations are found. The determination of different molecular structures of 2-Mercaptopyridine in aqueous solution is put into the context of proton-transfer in keto-enol and thione-thiol tautomerisms. (C) 2016 The Authors. Published by Elsevier B.V. Y1 - 2016 U6 - https://doi.org/10.1016/j.cplett.2016.01.050 SN - 0009-2614 SN - 1873-4448 VL - 647 SP - 103 EP - 106 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jay, Raphael M. A1 - Norell, Jesper A1 - Eckert, Sebastian A1 - Hantschmann, Markus A1 - Beye, Martin A1 - Kennedy, Brian A1 - Quevedo, Wilson A1 - Schlotter, William F. A1 - Dakovski, Georgi L. A1 - Minitti, Michael P. A1 - Hoffmann, Matthias C. A1 - Mitra, Ankush A1 - Moeller, Stefan P. A1 - Nordlund, Dennis A1 - Zhang, Wenkai A1 - Liang, Huiyang W. A1 - Kunnus, Kristian A1 - Kubicek, Katharina A1 - Techert, Simone A. A1 - Lundberg, Marcus A1 - Wernet, Philippe A1 - Gaffney, Kelly A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Disentangling Transient Charge Density and Metal-Ligand Covalency in Photoexcited Ferricyanide with Femtosecond Resonant Inelastic Soft X-ray Scattering JF - The journal of physical chemistry letters N2 - Soft X-ray spectroscopies are ideal probes of the local valence electronic structure of photocatalytically active metal sites. Here, we apply the selectivity of time resolved resonant inelastic X-ray scattering at the iron L-edge to the transient charge distribution of an optically excited charge-transfer state in aqueous ferricyanide. Through comparison to steady-state spectra and quantum chemical calculations, the coupled effects of valence-shell closing and ligand-hole creation are experimentally and theoretically disentangled and described in terms of orbital occupancy, metal-ligand covalency, and ligand field splitting, thereby extending established steady-state concepts to the excited-state domain. pi-Back-donation is found to be mainly determined by the metal site occupation, whereas the ligand hole instead influences sigma-donation. Our results demonstrate how ultrafast resonant inelastic X-ray scattering can help characterize local charge distributions around catalytic metal centers in short-lived charge-transfer excited states, as a step toward future rationalization and tailoring of photocatalytic capabilities of transition-metal complexes. Y1 - 2018 U6 - https://doi.org/10.1021/acs.jpclett.8b01429 SN - 1948-7185 VL - 9 IS - 12 SP - 3538 EP - 3543 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Niskanen, Johannes A1 - Fondell, Mattis A1 - Sahle, Christoph J. A1 - Eckert, Sebastian A1 - Jay, Raphael Martin A1 - Gilmore, Keith A1 - Pietzsch, Annette A1 - Dantz, Marcus A1 - Lu, Xingye A1 - McNally, Daniel E. A1 - Schmitt, Thorsten A1 - Vaz da Cruz, Vinicius A1 - Kimberg, Victor A1 - Föhlisch, Alexander A1 - Gel’mukhanov, Faris T1 - Compatibility of quantitative X-ray spectroscopy with continuous distribution models of water at ambient conditions JF - Proceedings of the National Academy of Sciences of the United States of America N2 - The phase diagram of water harbors controversial views on underlying structural properties of its constituting molecular moieties, its fluctuating hydrogen-bonding network, as well as pair-correlation functions. In this work, long energy-range detection of the X-ray absorption allows us to unambiguously calibrate the spectra for water gas, liquid, and ice by the experimental atomic ionization cross-section. In liquid water, we extract the mean value of 1.74 +/- 2.1% donated and accepted hydrogen bonds per molecule, pointing to a continuous-distribution model. In addition, resonant inelastic X-ray scattering with unprecedented energy resolution also supports continuous distribution of molecular neighborhoods within liquid water, as do X-ray emission spectra once the femtosecond scattering duration and proton dynamics in resonant X-ray-matter interaction are taken into account. Thus, X-ray spectra of liquid water in ambient conditions can be understood without a two-structure model, whereas the occurrence of nanoscale-length correlations within the continuous distribution remains open. KW - structure of water KW - X-ray spectroscopy KW - continuous distribution model Y1 - 2019 U6 - https://doi.org/10.1073/pnas.1815701116 SN - 0027-8424 VL - 116 IS - 10 SP - 4058 EP - 4063 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Vaz da Cruz, Vinicius A1 - Eckert, Sebastian A1 - Iannuzzi, Marcella A1 - Ertan, Emelie A1 - Pietzsch, Annette A1 - Couto, Rafael C. A1 - Niskanen, Johannes A1 - Fondell, Mattis A1 - Dantz, Marcus A1 - Schmitt, Thorsten A1 - Lu, Xingye A1 - McNally, Daniel A1 - Jay, Raphael Martin A1 - Kimberg, Victor A1 - Föhlisch, Alexander A1 - Odelius, Michael T1 - Probing hydrogen bond strength in liquid water by resonant inelastic X-ray scattering JF - Nature Communications N2 - Local probes of the electronic ground state are essential for understanding hydrogen bonding in aqueous environments. When tuned to the dissociative core-excited state at the O1s pre-edge of water, resonant inelastic X-ray scattering back to the electronic ground state exhibits a long vibrational progression due to ultrafast nuclear dynamics. We show how the coherent evolution of the OH bonds around the core-excited oxygen provides access to high vibrational levels in liquid water. The OH bonds stretch into the long-range part of the potential energy curve, which makes the X-ray probe more sensitive than infra-red spectroscopy to the local environment. We exploit this property to effectively probe hydrogen bond strength via the distribution of intramolecular OH potentials derived from measurements. In contrast, the dynamical splitting in the spectral feature of the lowest valence-excited state arises from the short-range part of the OH potential curve and is rather insensitive to hydrogen bonding. Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-08979-4 SN - 2041-1723 VL - 10 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Jay, Raphael Martin A1 - Eckert, Sebastian A1 - Fondell, Mattis A1 - Miedema, Piter S. A1 - Norell, Jesper A1 - Pietzsch, Annette A1 - Quevedo, Wilson A1 - Niskanen, Johannes A1 - Kunnus, Kristjan A1 - Föhlisch, Alexander T1 - The nature of frontier orbitals under systematic ligand exchange in (pseudo-)octahedral Fe(II) complexes JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - Understanding and controlling properties of transition metal complexes is a crucial step towards tailoring materials for sustainable energy applications. In a systematic approach, we use resonant inelastic X-ray scattering to study the influence of ligand substitution on the valence electronic structure around an aqueous iron(II) center. Exchanging cyanide with 2-2′-bipyridine ligands reshapes frontier orbitals in a way that reduces metal 3d charge delocalization onto the ligands. This net decrease of metal–ligand covalency results in lower metal-centered excited state energies in agreement with previously reported excited state dynamics. Furthermore, traces of solvent-effects were found indicating a varying interaction strength of the solvent with ligands of different character. Our results demonstrate how ligand exchange can be exploited to shape frontier orbitals of transition metal complexes in solution-phase chemistry; insights upon which future efforts can built when tailoring the functionality of photoactive systems for light-harvesting applications. Y1 - 2018 U6 - https://doi.org/10.1039/c8cp04341h SN - 1463-9076 SN - 1463-9084 VL - 20 IS - 44 SP - 27745 EP - 27751 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Eckert, Sebastian A1 - Norell, Jesper A1 - Jay, Raphael Martin A1 - Fondell, Mattis A1 - Mitzner, Rolf A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - T-1 Population as the Driver of Excited-State Proton-Transfer in 2-Thiopyridone JF - Chemistry - a European journal N2 - Excited-state proton transfer (ESPT) is a fundamental process in biomolecular photochemistry, but its underlying mediators often evade direct observation. We identify a distinct pathway for ESPT in aqueous 2-thiopyridone, by employing transient N1s X-ray absorption spectroscopy and multi-configurational spectrum simulations. Photoexcitations to the singlet S-2 and S-4 states both relax promptly through intersystem crossing to the triplet T-1 state. The T-1 state, through its rapid population and near nanosecond lifetime, mediates nitrogen site deprotonation by ESPT in a secondary intersystem crossing to the S-0 potential energy surface. This conclusively establishes a dominant ESPT pathway for the system in aqueous solution, which is also compatible with previous measurements in acetonitrile. Thereby, the hitherto open questions of the pathway for ESPT in the compound, including its possible dependence on excitation wavelength and choice of solvent, are resolved. KW - excited-state proton-transfer KW - intersystem crossing KW - nitrogen KW - photochemistry KW - X-ray absorption Y1 - 2019 U6 - https://doi.org/10.1002/chem.201804166 SN - 0947-6539 SN - 1521-3765 VL - 25 IS - 7 SP - 1733 EP - 1739 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Jay, Raphael Martin A1 - Eckert, Sebastian A1 - Vaz da Cruz, Vinicius A1 - Fondell, Mattis A1 - Mitzner, Rolf A1 - Föhlisch, Alexander T1 - Covalency-driven preservation of local charge densities in a metal-to-ligand charge-transfer excited iron photosensitizer JF - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition N2 - Charge-density rearrangements after metal-to-ligand charge-transfer excitation in an iron photosensitizer are investigated by R. M Jay, A. Fohlisch et al. in their Communication (DOI: 10.1002/anie.201904761). By using time-resolved X-ray absorption spectroscopy, surprising covalency-effects are revealed that inhibit charge-separation at the intra-molecular level. Furthermore, the underlying mechanism is proposed to be generally in effect for all commonly used photosensitizers in light-harvesting applications, which challenges the common perception of electronic charge-transfer. KW - charge-transfer KW - density functional calculations KW - iron KW - photochemistry KW - X-ray absorption spectroscopy Y1 - 2019 U6 - https://doi.org/10.1002/anie.201904761 SN - 1433-7851 SN - 1521-3773 VL - 58 IS - 31 SP - 10742 EP - 10746 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Pietzsch, Annette A1 - Niskanen, Johannes A1 - Vaz da Cruz, Vinicius A1 - Büchner, Robby A1 - Eckert, Sebastian A1 - Fondell, Mattis A1 - Jay, Raphael Martin A1 - Lu, Xingye A1 - McNally, Daniel A1 - Schmitt, Thorsten A1 - Föhlisch, Alexander T1 - Cuts through the manifold of molecular H2O potential energy surfaces in liquid water at ambient conditions JF - Proceedings of the National Academy of Sciences of the United States of America N2 - The fluctuating hydrogen bridge bonded network of liquid water at ambient conditions entails a varied ensemble of the underlying constituting H2O molecular moieties. This is mirrored in a manifold of the H2O molecular potentials. Subnatural line width resonant inelastic X-ray scattering allowed us to quantify the manifold of molecular potential energy surfaces along the H2O symmetric normal mode and the local asymmetric O-H bond coordinate up to 1 and 1.5 angstrom, respectively. The comparison of the single H2O molecular potentials and spectroscopic signatures with the ambient conditions liquid phase H2O molecular potentials is done on various levels. In the gas phase, first principles, Morse potentials, and stepwise harmonic potential reconstruction have been employed and benchmarked. In the liquid phase the determination of the potential energy manifold along the local asymmetric O-H bond coordinate from resonant inelastic X-ray scattering via the bound state oxygen ls to 4a(1) resonance is treated within these frameworks. The potential energy surface manifold along the symmetric stretch from resonant inelastic X-ray scattering via the oxygen 1 s to 2b(2) resonance is based on stepwise harmonic reconstruction. We find in liquid water at ambient conditions H2O molecular potentials ranging from the weak interaction limit to strongly distorted potentials which are put into perspective to established parameters, i.e., intermolecular O-H, H-H, and O-O correlation lengths from neutron scattering. KW - water KW - potential ene rgy surface KW - RIXS Y1 - 2022 U6 - https://doi.org/10.1073/pnas.2118101119 SN - 1091-6490 VL - 119 IS - 28 PB - National Acad. of Sciences CY - Washington, DC ER - TY - JOUR A1 - Eckert, Sebastian A1 - Beye, Martin A1 - Pietzsch, Annette A1 - Quevedo, Wilson A1 - Hantschmann, Markus A1 - Ochmann, Miguel A1 - Ross, Matthew A1 - Minitti, Michael P. A1 - Turner, Joshua J. A1 - Moeller, Stefan P. A1 - Schlotter, William F. A1 - Dakovski, Georgi L. A1 - Khalil, Munira A1 - Huse, Nils A1 - Föhlisch, Alexander T1 - Principles of femtosecond X-ray/optical cross-correlation with X-ray induced transient optical reflectivity in solids JF - Applied physics letters N2 - The discovery of ultrafast X-ray induced optical reflectivity changes enabled the development of X-ray/optical cross correlation techniques at X-ray free electron lasers worldwide. We have now linked through experiment and theory the fundamental excitation and relaxation steps with the transient optical properties in finite solid samples. Therefore, we gain a thorough interpretation and an optimized detection scheme of X-ray induced changes to the refractive index and the X-ray/optical cross correlation response. (C) 2015 AIP Publishing LLC. Y1 - 2015 U6 - https://doi.org/10.1063/1.4907949 SN - 0003-6951 SN - 1077-3118 VL - 106 IS - 6 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Eckert, Sebastian A1 - Mascarenhas, Eric Johnn A1 - Mitzner, Rolf A1 - Jay, Raphael Martin A1 - Pietzsch, Annette A1 - Fondell, Mattis A1 - Vaz da Cruz, Vinicius A1 - Föhlisch, Alexander T1 - From the free ligand to the transition metal complex BT - FeEDTA(-) formation seen at ligand K-Edges JF - Inorganic chemistry N2 - Chelating agents are an integral part of transition metal complex chemistry with broad biological and industrial relevance. The hexadentate chelating agent ethylenediaminetetraacetic acid (EDTA) has the capability to bind to metal ions at its two nitrogen and four of its carboxylate oxygen sites. We use resonant inelastic X-ray scattering at the 1s absorption edge of the aforementioned elements in EDTA and the iron(III)-EDTA complex to investigate the impact of the metal-ligand bond formation on the electronic structure of EDTA. Frontier orbital distortions, occupation changes, and energy shifts through metal- ligand bond formation are probed through distinct spectroscopic signatures. KW - Energy KW - Ligands KW - Metals KW - Nitrogen KW - Oxygen Y1 - 2022 U6 - https://doi.org/10.1021/acs.inorgchem.2c00789 SN - 0020-1669 SN - 1520-510X VL - 61 IS - 27 SP - 10321 EP - 10328 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Vaz da Cruz, Vinícius A1 - Ignatova, Nina A1 - Couto, Rafael A1 - Fedotov, Daniil A1 - Rehn, Dirk R. A1 - Savchenko, Viktoriia A1 - Norman, Patrick A1 - Ågren, Hans A1 - Polyutov, Sergey A1 - Niskanen, Johannes A1 - Eckert, Sebastian A1 - Jay, Raphael Martin A1 - Fondell, Mattis A1 - Schmitt, Thorsten A1 - Pietzsch, Annette A1 - Föhlisch, Alexander A1 - Odelius, Michael A1 - Kimberg, Victor A1 - Gel’mukhanov, Faris T1 - Nuclear dynamics in resonant inelastic X-ray scattering and X-ray absorption of methanol JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - We report on a combined theoretical and experimental study of core-excitation spectra of gas and liquid phase methanol as obtained with the use of X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). The electronic transitions are studied with computational methods that include strict and extended second-order algebraic diagrammatic construction [ADC(2) and ADC(2)-x], restricted active space second-order perturbation theory, and time-dependent density functional theory-providing a complete assignment of the near oxygen K-edge XAS. We show that multimode nuclear dynamics is of crucial importance for explaining the available experimental XAS and RIXS spectra. The multimode nuclear motion was considered in a recently developed "mixed representation" where dissociative states and highly excited vibrational modes are accurately treated with a time-dependent wave packet technique, while the remaining active vibrational modes are described using Franck-Condon amplitudes. Particular attention is paid to the polarization dependence of RIXS and the effects of the isotopic substitution on the RIXS profile in the case of dissociative core-excited states. Our approach predicts the splitting of the 2a RIXS peak to be due to an interplay between molecular and pseudo-atomic features arising in the course of transitions between dissociative core- and valence-excited states. The dynamical nature of the splitting of the 2a peak in RIXS of liquid methanol near pre-edge core excitation is shown. The theoretical results are in good agreement with our liquid phase measurements and gas phase experimental data available from the literature. (C) 2019 Author(s). Y1 - 2019 U6 - https://doi.org/10.1063/1.5092174 SN - 0021-9606 SN - 1089-7690 VL - 150 IS - 23 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Schreck, Simon A1 - Beye, Martin A1 - Sellberg, Jonas A. A1 - McQueen, Trevor A1 - Laksmono, Hartawan A1 - Kennedy, Brian A1 - Eckert, Sebastian A1 - Schlesinger, Daniel A1 - Nordlund, Dennis A1 - Ogasawara, Hirohito A1 - Sierra, Raymond G. A1 - Segtnan, Vegard H. A1 - Kubicek, Katharina A1 - Schlotter, William F. A1 - Dakovski, Georgi L. A1 - Moeller, Stefan P. A1 - Bergmann, Uwe A1 - Techert, Simone A1 - Pettersson, Lars G. M. A1 - Wernet, Philippe A1 - Bogan, Michael J. A1 - Harada, Yoshihisa A1 - Nilsson, Anders A1 - Föhlisch, Alexander T1 - Reabsorption of soft x-ray emission at high x-ray free-electron laserfluences JF - Physical review letters N2 - We report on oxygen K-edge soft x-ray emission spectroscopy from a liquid water jet at the Linac Coherent Light Source. We observe significant changes in the spectral content when tuning over a wide range of incident x-ray fluences. In addition the total emission yield decreases at high fluences. These modifications result from reabsorption of x-ray emission by valence-excited molecules generated by the Auger cascade. Our observations have major implications for future x-ray emission studies at intense x-ray sources. We highlight the importance of the x-ray pulse length with respect to the core-hole lifetime. Y1 - 2014 U6 - https://doi.org/10.1103/PhysRevLett.113.153002 SN - 0031-9007 SN - 1079-7114 VL - 113 IS - 15 PB - American Physical Society CY - College Park ER - TY - GEN A1 - Niskanen, Johannes A1 - Fondell, Mattis A1 - Sahle, Christoph J. A1 - Eckert, Sebastian A1 - Jay, Raphael Martin A1 - Gilmore, Keith A1 - Pietzsch, Annette A1 - Dantz, Marcus A1 - Lu, Xingye A1 - McNally, Daniel E. A1 - Schmitt, Thorsten A1 - Vaz da Cruz, Vinicius A1 - Kimberg, Victor A1 - Föhlisch, Alexander T1 - Reply to Pettersson et al.: Why X-ray spectral features are compatible to continuous distribution models in ambient water T2 - Proceedings of the National Academy of Sciences of the United States of America Y1 - 2019 U6 - https://doi.org/10.1073/pnas.1909551116 SN - 0027-8424 VL - 116 IS - 35 SP - 17158 EP - 17159 PB - National Acad. of Sciences CY - Washington ER - TY - GEN A1 - Eckert, Sebastian A1 - Miedema, Piter A1 - Quevedo, Wilson A1 - O'Cinneide, B. A1 - Fondell, Mattis A1 - Beye, Martin A1 - Pietzsch, Annette A1 - Ross, Matthew R. A1 - Khalil, Munira A1 - Föhlisch, Alexander T1 - Molecular structures and protonation state of 2-Mercaptopyridine in aqueous solution T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The speciation of 2-Mercaptopyridine in aqueous solution has been investigated with nitrogen 1s Near Edge X-ray Absorption Fine Structure spectroscopy and time dependent Density Functional Theory. The prevalence of distinct species as a function of the solvent basicity is established. No indications of dimerization towards high concentrations are found. The determination of different molecular structures of 2-Mercaptopyridine in aqueous solution is put into the context of proton-transfer in keto-enol and thione-thiol tautomerisms. (C) 2016 The Authors. Published by Elsevier B.V. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 953 KW - ray-emission-spectroscopy KW - x-ray KW - hydroxypyridine-pyridone KW - protomeric equilibria KW - self-association KW - CU(110) KW - valence Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437473 SN - 1866-8372 IS - 953 SP - 103 EP - 106 ER - TY - CHAP A1 - Jacqmin, Julien A1 - Özdemir, Paker Doğu A1 - Fell Kurban, Caroline A1 - Tunç Pekkan, Zelha A1 - Koskinen, Johanna A1 - Suonpää, Maija A1 - Seng, Cheyvuth A1 - Carlon, May Kristine Jonson A1 - Gayed, John Maurice A1 - Cross, Jeffrey S. A1 - Langseth, Inger A1 - Jacobsen, Dan Yngve A1 - Haugsbakken, Halvdan A1 - Bethge, Joseph A1 - Serth, Sebastian A1 - Staubitz, Thomas A1 - Wuttke, Tobias A1 - Nordemann, Oliver A1 - Das, Partha-Pratim A1 - Meinel, Christoph A1 - Ponce, Eva A1 - Srinath, Sindhu A1 - Allegue, Laura A1 - Perach, Shai A1 - Alexandron, Giora A1 - Corti, Paola A1 - Baudo, Valeria A1 - Turró, Carlos A1 - Moura Santos, Ana A1 - Nilsson, Charlotta A1 - Maldonado-Mahauad, Jorge A1 - Valdiviezo, Javier A1 - Carvallo, Juan Pablo A1 - Samaniego-Erazo, Nicolay A1 - Poce, Antonella A1 - Re, Maria Rosaria A1 - Valente, Mara A1 - Karp Gershon, Sa’ar A1 - Ruipérez-Valiente, José A. A1 - Despujol, Ignacio A1 - Busquets, Jaime A1 - Kerr, John A1 - Lorenz, Anja A1 - Schön, Sandra A1 - Ebner, Martin A1 - Wittke, Andreas A1 - Beirne, Elaine A1 - Nic Giolla Mhichíl, Mairéad A1 - Brown, Mark A1 - Mac Lochlainn, Conchúr A1 - Topali, Paraskevi A1 - Chounta, Irene-Angelica A1 - Ortega-Arranz, Alejandro A1 - Villagrá-Sobrino, Sara L. A1 - Martínez-Monés, Alejandra A1 - Blackwell, Virginia Katherine A1 - Wiltrout, Mary Ellen A1 - Rami Gaddem, Mohamed A1 - Hernández Reyes, César Augusto A1 - Nagahama, Toru A1 - Buchem, Ilona A1 - Okatan, Ebru A1 - Khalil, Mohammad A1 - Casiraghi, Daniela A1 - Sancassani, Susanna A1 - Brambilla, Federica A1 - Mihaescu, Vlad A1 - Andone, Diana A1 - Vasiu, Radu A1 - Şahin, Muhittin A1 - Egloffstein, Marc A1 - Bothe, Max A1 - Rohloff, Tobias A1 - Schenk, Nathanael A1 - Schwerer, Florian A1 - Ifenthaler, Dirk A1 - Hense, Julia A1 - Bernd, Mike ED - Meinel, Christoph ED - Staubitz, Thomas ED - Schweiger, Stefanie ED - Friedl, Christian ED - Kiers, Janine ED - Ebner, Martin ED - Lorenz, Anja ED - Ubachs, George ED - Mongenet, Catherine ED - Ruipérez-Valiente, José A. ED - Cortes Mendez, Manoel T1 - EMOOCs 2021 N2 - From June 22 to June 24, 2021, Hasso Plattner Institute, Potsdam, hosted the seventh European MOOC Stakeholder Summit (EMOOCs 2021) together with the eighth ACM Learning@Scale Conference. Due to the COVID-19 situation, the conference was held fully online. The boost in digital education worldwide as a result of the pandemic was also one of the main topics of this year’s EMOOCs. All institutions of learning have been forced to transform and redesign their educational methods, moving from traditional models to hybrid or completely online models at scale. The learnings, derived from practical experience and research, have been explored in EMOOCs 2021 in six tracks and additional workshops, covering various aspects of this field. In this publication, we present papers from the conference’s Experience Track, the Policy Track, the Business Track, the International Track, and the Workshops. KW - e-learning KW - microcredential KW - MOOC KW - digital education KW - experience KW - online course design KW - online course creation KW - higher education Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-510300 SN - 978-3-86956-512-5 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Serth, Sebastian A1 - Staubitz, Thomas A1 - van Elten, Martin A1 - Meinel, Christoph ED - Gamage, Dilrukshi T1 - Measuring the effects of course modularizations in online courses for life-long learners T2 - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät N2 - Many participants in Massive Open Online Courses are full-time employees seeking greater flexibility in their time commitment and the available learning paths. We recently addressed these requirements by splitting up our 6-week courses into three 2-week modules followed by a separate exam. Modularizing courses offers many advantages: Shorter modules are more sustainable and can be combined, reused, and incorporated into learning paths more easily. Time flexibility for learners is also improved as exams can now be offered multiple times per year, while the learning content is available independently. In this article, we answer the question of which impact this modularization has on key learning metrics, such as course completion rates, learning success, and no-show rates. Furthermore, we investigate the influence of longer breaks between modules on these metrics. According to our analysis, course modules facilitate more selective learning behaviors that encourage learners to focus on topics they are the most interested in. At the same time, participation in overarching exams across all modules seems to be less appealing compared to an integrated exam of a 6-week course. While breaks between the modules increase the distinctive appearance of individual modules, a break before the final exam further reduces initial interest in the exams. We further reveal that participation in self-paced courses as a preparation for the final exam is unlikely to attract new learners to the course offerings, even though learners' performance is comparable to instructor-paced courses. The results of our long-term study on course modularization provide a solid foundation for future research and enable educators to make informed decisions about the design of their courses. T3 - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät - 17 KW - Massive Open Online Course (MOOC) KW - course design KW - modularization KW - learning path KW - flexibility KW - e-learning KW - assignments KW - self-paced learning Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-589182 IS - 17 ER - TY - GEN A1 - Eckert, Sebastian A1 - Norell, Jesper A1 - Miedema, Piter S. A1 - Beye, Martin A1 - Fondell, Mattis A1 - Quevedo, Wilson A1 - Kennedy, Brian A1 - Hantschmann, Markus A1 - Pietzsch, Annette A1 - van Kuiken, Benjamin E. A1 - Ross, Matthew A1 - Minitti, Michael P. A1 - Moeller, Stefan P. A1 - Schlotter, William F. A1 - Khalil, Munira A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Untersuchung unabhängiger N‐H‐ und N‐C‐Bindungsverformungen auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Die Femtosekundendynamik nach resonanten Photoanregungen mit optischen und Röntgenpulsen ermöglicht eine selektive Verformung von chemischen N‐H‐ und N‐C‐Bindungen in 2‐Thiopyridon in wässriger Lösung. Die Untersuchung der orbitalspezifischen elektronischen Struktur und ihrer Dynamik auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung an der N1s‐Resonanz am Synchrotron und dem Freie‐Elektronen‐Laser LCLS in Kombination mit quantenchemischen Multikonfigurationsberechnungen erbringen den direkten Nachweis dieser kontrollierten photoinduzierten Molekülverformungen und ihrer ultrakurzen Zeitskala. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1121 KW - Photochemie KW - Protonierung KW - RIXS (resonante inelastische Röntgenstreuung) KW - Selektiver Bindungsbruch KW - Stickstoff Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436688 SN - 1866-8372 IS - 1121 ER - TY - GEN A1 - Eckert, Sebastian A1 - Norell, Jesper A1 - Miedema, Piter S. A1 - Beye, Martin A1 - Fondell, Mattis A1 - Quevedo, Wilson A1 - Kennedy, Brian A1 - Hantschmann, Markus A1 - Pietzsch, Annette A1 - van Kuiken, Benjamin E. A1 - Ross, Matthew A1 - Minitti, Michael P. A1 - Moeller, Stefan P. A1 - Schlotter, William F. A1 - Khalil, Munira A1 - Odelius, Michael A1 - Föhlisch, Alexander T1 - Ultrafast Independent N-H and N-C Bond Deformation Investigated with Resonant Inelastic X-Ray Scattering T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The femtosecond excited-state dynamics following resonant photoexcitation enable the selective deformation of N-H and N-C chemical bonds in 2-thiopyridone in aqueous solution with optical or X-ray pulses. In combination with multiconfigurational quantum-chemical calculations, the orbital-specific electronic structure and its ultrafast dynamics accessed with resonant inelastic X-ray scattering at the N 1s level using synchrotron radiation and the soft X-ray free-electron laser LCLS provide direct evidence for this controlled photoinduced molecular deformation and its ultrashort time-scale. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1115 KW - nitrogen KW - photochemistry KW - protonation KW - RIXS (resonant inelastic X-ray scattering) KW - selective bond cleavage Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436873 SN - 1866-8372 IS - 1115 ER - TY - JOUR A1 - Serth, Sebastian A1 - Staubitz, Thomas A1 - van Elten, Martin A1 - Meinel, Christoph ED - Gamage, Dilrukshi T1 - Measuring the effects of course modularizations in online courses for life-long learners JF - Frontiers in Education N2 - Many participants in Massive Open Online Courses are full-time employees seeking greater flexibility in their time commitment and the available learning paths. We recently addressed these requirements by splitting up our 6-week courses into three 2-week modules followed by a separate exam. Modularizing courses offers many advantages: Shorter modules are more sustainable and can be combined, reused, and incorporated into learning paths more easily. Time flexibility for learners is also improved as exams can now be offered multiple times per year, while the learning content is available independently. In this article, we answer the question of which impact this modularization has on key learning metrics, such as course completion rates, learning success, and no-show rates. Furthermore, we investigate the influence of longer breaks between modules on these metrics. According to our analysis, course modules facilitate more selective learning behaviors that encourage learners to focus on topics they are the most interested in. At the same time, participation in overarching exams across all modules seems to be less appealing compared to an integrated exam of a 6-week course. While breaks between the modules increase the distinctive appearance of individual modules, a break before the final exam further reduces initial interest in the exams. We further reveal that participation in self-paced courses as a preparation for the final exam is unlikely to attract new learners to the course offerings, even though learners' performance is comparable to instructor-paced courses. The results of our long-term study on course modularization provide a solid foundation for future research and enable educators to make informed decisions about the design of their courses. KW - Massive Open Online Course (MOOC) KW - course design KW - modularization KW - learning path KW - flexibility KW - e-learning KW - assignments KW - self-paced learning Y1 - 2022 U6 - https://doi.org/10.3389/feduc.2022.1008545 SN - 2504-284X VL - 7 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Staubitz, Thomas A1 - Serth, Sebastian A1 - Thomas, Max A1 - Ebner, Martin A1 - Koschutnig-Ebner, Markus A1 - Rampelt, Florian A1 - von Stetten, Alexander A1 - Wittke, Andreas ED - Meinel, Christoph ED - Schweiger, Stefanie ED - Staubitz, Thomas ED - Conrad, Robert ED - Alario Hoyos, Carlos ED - Ebner, Martin ED - Sancassani, Susanna ED - Żur, Agnieszka ED - Friedl, Christian ED - Halawa, Sherif ED - Gamage, Dilrukshi ED - Scott, Jeffrey ED - Kristine Jonson Carlon, May ED - Deville, Yves ED - Gaebel, Michael ED - Delgado Kloos, Carlos ED - von Schmieden, Karen T1 - A metastandard for the international exchange of MOOCs BT - the MOOChub as first prototype JF - EMOOCs 2023 : Post-Covid Prospects for Massive Open Online Courses - Boost or Backlash? N2 - The MOOChub is a joined web-based catalog of all relevant German and Austrian MOOC platforms that lists well over 750 Massive Open Online Courses (MOOCs). Automatically building such a catalog requires that all partners describe and publicly offer the metadata of their courses in the same way. The paper at hand presents the genesis of the idea to establish a common metadata standard and the story of its subsequent development. The result of this effort is, first, an open-licensed de-facto-standard, which is based on existing commonly used standards and second, a first prototypical platform that is using this standard: the MOOChub, which lists all courses of the involved partners. This catalog is searchable and provides a more comprehensive overview of basically all MOOCs that are offered by German and Austrian MOOC platforms. Finally, the upcoming developments to further optimize the catalog and the metadata standard are reported. KW - Digitale Bildung KW - Kursdesign KW - MOOC KW - Micro Degree KW - Online-Lehre KW - Onlinekurs KW - Onlinekurs-Produktion KW - digital education KW - e-learning KW - micro degree KW - micro-credential KW - online course creation KW - online course design KW - online teaching Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-624154 SP - 147 EP - 161 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Norell, Jesper A1 - Jay, Raphael Martin A1 - Hantschmann, Markus A1 - Eckert, Sebastian A1 - Guo, Meiyuan A1 - Gaffney, Kelly J. A1 - Wernet, Philippe A1 - Lundberg, Marcus A1 - Föhlisch, Alexander A1 - Odelius, Michael T1 - Fingerprints of electronic, spin and structural dynamics from resonant inelastic soft X-ray scattering in transient photo-chemical species T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - We describe how inversion symmetry separation of electronic state manifolds in resonant inelastic soft X-ray scattering (RIXS) can be applied to probe excited-state dynamics with compelling selectivity. In a case study of Fe L-3-edge RIXS in the ferricyanide complex Fe(CN)(6)(3-), we demonstrate with multi-configurational restricted active space spectrum simulations how the information content of RIXS spectral fingerprints can be used to unambiguously separate species of different electronic configurations, spin multiplicities, and structures, with possible involvement in the decay dynamics of photo-excited ligand-to-metal charge-transfer. Specifically, we propose that this could be applied to confirm or reject the presence of a hitherto elusive transient Quartet species. Thus, RIXS offers a particular possibility to settle a recent controversy regarding the decay pathway, and we expect the technique to be similarly applicable in other model systems of photo-induced dynamics. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 779 KW - charge-transfer KW - relaxation dynamics KW - absorption-spectra KW - energy-conversion KW - basis-sets KW - ab-initio KW - complexes KW - photoelectron KW - spectroscopy KW - simulations Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437493 SN - 1866-8372 IS - 779 SP - 7243 EP - 7253 ER - TY - BOOK A1 - Fuhrmann, Michaela A1 - Schubarth, Wilfried A1 - Schulze-Reichelt, Friederike A1 - Mauermeister, Sylvi A1 - Seidel, Andreas A1 - Hartmann, Nina A1 - Erdmann, Melinda A1 - Apostolow, Benjamin A1 - Wagner, Laura A1 - Berndt, Sarah A1 - Wippermann, Melanie A1 - Ratzlaff, Olaf A1 - Lumpe, Matthias A1 - Kirjuchina, Ljuba A1 - Rost, Sophia A1 - Zurek, Peter Paul A1 - Faaß, Marcel A1 - Schellhorn, Sebastian A1 - Frank, Mario A1 - Kreitz, Christoph A1 - Wagner, Nelli A1 - Jenneck, Julia A1 - Kleemann, Katrin A1 - Vock, Miriam A1 - Schröder, Christian A1 - Erdmann, Kathrin A1 - Koziol, Matthias A1 - Meißner, Marlen A1 - Dibiasi, Anna A1 - Unger, Martin A1 - Piskunova, Elena V. A1 - Bahmutskiy, Andrey E. A1 - Bessonova, Ekatarina A. A1 - Borovik, Ludmila K. ED - Schubarth, Wilfried ED - Mauermeister, Sylvi ED - Schulze-Reichelt, Friederike ED - Seidel, Andreas T1 - Alles auf Anfang! BT - Befunde und Perspektiven zum Studieneingang T3 - Potsdamer Beiträge zur Hochschulforschung N2 - Im Zuge der Bologna-Reform ist an Hochschulen vieles in Bewegung gekommen. Studium und Lehre sind stärker ins Blickfeld gerückt. Dabei kommt der Studieneingangsphase besondere Bedeutung zu, werden doch hier die Weichen für ein erfolgreiches Studium gestellt. Deshalb ist es verständlich, dass die Hauptanstrengungen der Hochschulen auf den Studieneingang gerichtet sind – ganz nach dem Motto: „Auf den Anfang kommt es an!“. Konsens herrscht dahingehend, dass der Studieneingang neu zu gestalten ist, doch beim „Wie?“ gibt es unterschiedliche Antworten. Zugleich wird immer deutlicher, dass eine wirksame Neugestaltung der Eingangsphase nur mit einer umfassenden Reform des Studiums gelingen kann. Ziel des vierten Bandes der Potsdamer Beiträge zur Hochschulforschung ist es, eine Zwischenbilanz der Debatte zum Studieneingang zu ziehen. Auf der Basis empirischer Studien werden unterschiedliche Perspektiven auf den Studieneingang eingenommen und Empfehlungen zur Optimierung des Studieneingangs abgeleitet. Die zahlreichen Untersuchungsergebnisse Potsdamer Forschergruppen werden durch weitere nationale sowie internationale Perspektiven ergänzt. Der Band richtet sich an alle, die sich für die Entwicklung an Hochschulen interessieren. T3 - Potsdamer Beiträge zur Hochschulforschung - 4 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-422965 SN - 978-3-86956-452-4 SN - 2192-1075 SN - 2192-1083 IS - 4 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - BOOK A1 - Frieß, Nina A1 - Lenz, Gunnar A1 - Martin, Erik A1 - Brunová, Marie A1 - Burghardt, Anja A1 - Donska, Mariya A1 - Efimova, Svetlana A1 - Imanov, Anar A1 - Kornmesser, Sebastian A1 - Koy, Magdalena A1 - Ananka, Yaraslava A1 - Fertig, Julia A1 - Hargaßner, Julia A1 - Kuprina, Olena A1 - Jandl, Ingeborg A1 - Neca, Łukasz A1 - Pavlova, Jana A1 - Smyshliaeva, Maria A1 - Adamczak, Katarzyna A1 - Gauss, Galina A1 - Gorfinkel, Olga ED - Frieß, Nina ED - Lenz, Gunnar ED - Martin, Erik T1 - Grenzräume – Grenzbewegungen BT - Ergebnisse der Arbeitstreffen des Jungen Forums Slavistische Literaturwissenschaft in Basel 2013 und Frankfurt (Oder) und Słubice 2014 ; Bd. 2 N2 - Der vorliegende Sammelband vereinigt die Beiträge der 12. und 13. Tagung des Jungen Forums Slavistische Literaturwissenschaft (JFSL) in Basel 2013 und Frankfurt (Oder) und Słubice 2014. Unter den thematischen Leitbegriffen Grenzräume – Grenzbewegungen präsentiert er Einblicke in die Arbeit von Nachwuchswissenschaftlerinnen und -wissenschaftlern der deutschsprachigen slavischen Literatur- und Kulturwissenschaft. N2 - This anthology contains the contributions of the 12th and 13th JFSL meeting in Basel in 2013 and Frankfurt (Oder) and Słubice 2014, respectively. Under the topic Boundaries in Space — Boundaries in Motion it presents an insight into the work of young researchers of Slavic literature and culture studies. KW - Gender KW - Grenzen KW - Performanz KW - Postcolonial KW - Postkolonial KW - Slavistik KW - Borders KW - Gender KW - Performance KW - Slavic studies Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-86773 SN - 978-3-86956-359-6 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Goswami, Bedartha A1 - Boers, Niklas A1 - Rheinwalt, Aljoscha A1 - Marwan, Norbert A1 - Heitzig, Jobst A1 - Breitenbach, Sebastian Franz Martin A1 - Kurths, Jürgen T1 - Abrupt transitions in time series with uncertainties T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Identifying abrupt transitions is a key question in various disciplines. Existing transition detection methods, however, do not rigorously account for time series uncertainties, often neglecting them altogether or assuming them to be independent and qualitatively similar. Here, we introduce a novel approach suited to handle uncertainties by representing the time series as a time-ordered sequence of probability density functions. We show how to detect abrupt transitions in such a sequence using the community structure of networks representing probabilities of recurrence. Using our approach, we detect transitions in global stock indices related to well-known periods of politico-economic volatility. We further uncover transitions in the El Nino-Southern Oscillation which coincide with periods of phase locking with the Pacific Decadal Oscillation. Finally, we provide for the first time an 'uncertainty-aware' framework which validates the hypothesis that ice-rafting events in the North Atlantic during the Holocene were synchronous with a weakened Asian summer monsoon. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 576 KW - North-Atlantic climate KW - Indian monsoon KW - Holocene KW - teleconnections KW - variability KW - periods KW - records Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423111 SN - 1866-8372 IS - 576 ER - TY - JOUR A1 - Goswami, Bedartha A1 - Boers, Niklas A1 - Rheinwalt, Aljoscha A1 - Marwan, Norbert A1 - Heitzig, Jobst A1 - Breitenbach, Sebastian Franz Martin A1 - Kurths, Jürgen T1 - Abrupt transitions in time series with uncertainties JF - Nature Communications N2 - Identifying abrupt transitions is a key question in various disciplines. Existing transition detection methods, however, do not rigorously account for time series uncertainties, often neglecting them altogether or assuming them to be independent and qualitatively similar. Here, we introduce a novel approach suited to handle uncertainties by representing the time series as a time-ordered sequence of probability density functions. We show how to detect abrupt transitions in such a sequence using the community structure of networks representing probabilities of recurrence. Using our approach, we detect transitions in global stock indices related to well-known periods of politico-economic volatility. We further uncover transitions in the El Niño-Southern Oscillation which coincide with periods of phase locking with the Pacific Decadal Oscillation. Finally, we provide for the first time an ‘uncertainty-aware’ framework which validates the hypothesis that ice-rafting events in the North Atlantic during the Holocene were synchronous with a weakened Asian summer monsoon. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-017-02456-6 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Breitenbach, Sebastian Franz Martin A1 - Adkins, Jess F. A1 - Meyer, Hanno A1 - Marwan, Norbert A1 - Kumar, Kanikicharla Krishna A1 - Haug, Gerald H. T1 - Strong influence of water vapor source dynamics on stable isotopes in precipitation observed in Southern Meghalaya, NE India N2 - To calibrate delta O-18 time-series from speleothems in the eastern Indian summer monsoon (ISM) region of India, and to understand the moisture regime over the northern Bay of Bengal (BoB) we analyze the delta O-18 and delta D of rainwater, collected in 2007 and 2008 near Cherrapunji, India. delta D values range from + 18.5 parts per thousand to 144.4 parts per thousand, while delta O-18 varies between +0.8 parts per thousand and 18.8 parts per thousand. The Local Meteoric Water Line (LMWL) is found to be indistinguishable from the Global Meteoric Water Line (GMWL). Late ISM (September-October) rainfall exhibits lowest delta O-18 and delta D values, with little relationship to the local precipitation amount. There is a trend to lighter isotope values over the course of the ISM, but it does not correlate with the patterns of temperature and rainfall amount delta O-18 and delta D time-series have to be interpreted with caution in terms of the 'amount effect' in this subtropical region. We find that the temporal trend in delta O-18 reflects increasing transport distance during the ISM, isotopic changes in the northern BoB surface waters during late ISM, and vapor re-equilibration with rain droplets. Using an isotope box model for surface ocean waters, we quantify the potential influence of river runoff on the isotopic composition of the seasonal freshwater plume in the northern BoB. Temporal variations in this source can contribute up to 25% of the observed changes in stable isotopes of precipitation in NE India. To delineate other moisture sources, we use backward trajectory computations and find a strong correlation between source region and isotopic composition. Palaeoclimatic stable isotope time-series from northeast Indian speleothems likely reflect changes in moisture source and transport pathway, as well as the isotopic composition of the BoB surface water, all of which in turn reflect ISM strength. Stalagmite records from the region can therefore be interpreted as integrated measures of the ISM strength. Y1 - 2010 UR - http://www.sciencedirect.com/science/journal/0012821X U6 - https://doi.org/10.1016/j.epsl.2010.01.038 SN - 0012-821X ER - TY - JOUR A1 - Lechleitner, Franziska A. A1 - Baldini, James U. L. A1 - Breitenbach, Sebastian Franz Martin A1 - Fohlmeister, Jens Bernd A1 - McIntyre, Cameron A1 - Goswami, Bedartha A1 - Jamieson, Robert A. A1 - van der Voort, Tessa S. A1 - Prufer, Keith A1 - Marwan, Norbert A1 - Culleton, Brendan J. A1 - Kennett, Douglas J. A1 - Asmerom, Yemane A1 - Polyak, Victor A1 - Eglinton, Timothy I. T1 - Hydrological and climatological controls on radiocarbon concentrations in a tropical stalagmite JF - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society N2 - Precisely-dated stalagmites are increasingly important archives for the reconstruction of terrestrial paleoclimate at very high temporal resolution. In-depth understanding of local conditions at the cave site and of the processes driving stalagmite deposition is of paramount importance for interpreting proxy signals incorporated in stalagmite carbonate. Here we present a sub-decadally resolved dead carbon fraction (DCF) record for a stalagmite from Yok Balum Cave (southern Belize). The record is coupled to parallel stable carbon isotope (delta C-13) and U/Ca measurements, as well as radiocarbon (C-14) measurements from soils overlying the cave system. Using a karst carbon cycle model we disentangle the importance of soil and karst processes on stalagmite DCF incorporation, revealing a dominant host rock dissolution control on total DCF. Covariation between DCF, delta C-13, and U/Ca indicates that karst processes are a common driver of all three parameters, suggesting possible use of delta C-13 and trace element ratios to independently quantify DCF variability. A statistically significant multi-decadal lag of variable length exists between DCF and reconstructed solar activity, suggesting that solar activity influenced regional precipitation in Mesoamerica over the past 1500 years, but that the relationship was non-static. Although the precise nature of the observed lag is unclear, solar-induced changes in North Atlantic oceanic and atmospheric dynamics may play a role. (C) 2016 Elsevier Ltd. All rights reserved. KW - Stalagmite KW - Tropics KW - Radiocarbon KW - Trace elements KW - Hydroclimate Y1 - 2016 U6 - https://doi.org/10.1016/j.gca.2016.08.039 SN - 0016-7037 SN - 1872-9533 VL - 194 SP - 233 EP - 252 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Breitenbach, Sebastian Franz Martin A1 - Rehfeld, Kira A1 - Goswami, Bedartha A1 - Baldini, James U. L. A1 - Ridley, H. E. A1 - Kennett, D. J. A1 - Prufer, K. M. A1 - Aquino, Valorie V. A1 - Asmerom, Yemane A1 - Polyak, V. J. A1 - Cheng, Hai A1 - Kurths, Jürgen A1 - Marwan, Norbert T1 - Constructing Proxy Records from Age models (COPRA) JF - Climate of the past : an interactive open access journal of the European Geosciences Union N2 - Reliable age models are fundamental for any palaeoclimate reconstruction. Available interpolation procedures between age control points are often inadequately reported, and very few translate age uncertainties to proxy uncertainties. Most available modeling algorithms do not allow incorporation of layer counted intervals to improve the confidence limits of the age model in question. We present a framework that allows detection and interactive handling of age reversals and hiatuses, depth-age modeling, and proxy-record reconstruction. Monte Carlo simulation and a translation procedure are used to assign a precise time scale to climate proxies and to translate dating uncertainties to uncertainties in the proxy values. The presented framework allows integration of incremental relative dating information to improve the final age model. The free software package COPRA1.0 facilitates easy interactive usage. Y1 - 2012 U6 - https://doi.org/10.5194/cp-8-1765-2012 SN - 1814-9324 VL - 8 IS - 5 SP - 1765 EP - 1779 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Bilz, Ludwig A1 - Goldfriedrich, Martin A1 - John, Nancy A1 - Fischer, Saskia M. A1 - Wachs, Sebastian A1 - Schubarth, Wilfried T1 - Mobbingerfahrungen von Schülerinnen und Schüler mit und ohne Förderbedarf an inklusiven Schulen JF - Leistung und Wohlbefinden in der Schule: Herausforderung Inklusion Y1 - 2018 SN - 978-3-7799-3859-0 SN - 978-3-7799-4981-7 SP - 272 EP - 286 PB - Belz CY - Weinheim ER - TY - JOUR A1 - Lechleitner, Franziska A. A1 - Breitenbach, Sebastian Franz Martin A1 - Rehfeld, Kira A1 - Ridley, Harriet E. A1 - Asmerom, Yemane A1 - Prufer, Keith M. A1 - Marwan, Norbert A1 - Goswami, Bedartha A1 - Kennett, Douglas J. A1 - Aquino, Valorie V. A1 - Polyak, Victor A1 - Haug, Gerald H. A1 - Eglinton, Timothy I. A1 - Baldini, James U. L. T1 - Tropical rainfall over the last two millennia: evidence for a low-latitude hydrologic seesaw JF - Scientific reports N2 - The presence of a low-to mid-latitude interhemispheric hydrologic seesaw is apparent over orbital and glacial-interglacial timescales, but its existence over the most recent past remains unclear. Here we investigate, based on climate proxy reconstructions from both hemispheres, the inter-hemispherical phasing of the Intertropical Convergence Zone (ITCZ) and the low-to mid-latitude teleconnections in the Northern Hemisphere over the past 2000 years. A clear feature is a persistent southward shift of the ITCZ during the Little Ice Age until the beginning of the 19th Century. Strong covariation between our new composite ITCZ-stack and North Atlantic Oscillation (NAO) records reveals a tight coupling between these two synoptic weather and climate phenomena over decadal-to-centennial timescales. This relationship becomes most apparent when comparing two precisely dated, high-resolution paleorainfall records from Belize and Scotland, indicating that the low-to mid-latitude teleconnection was also active over annual-decadal timescales. It is likely a combination of external forcing, i.e., solar and volcanic, and internal feedbacks, that drives the synchronous ITCZ and NAO shifts via energy flux perturbations in the tropics. Y1 - 2017 U6 - https://doi.org/10.1038/srep45809 SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Lechleitner, Franziska A. A1 - Breitenbach, Sebastian Franz Martin A1 - Cheng, Hai A1 - Plessen, Birgit A1 - Rehfeld, Kira A1 - Goswami, Bedartha A1 - Marwan, Norbert A1 - Eroglu, Deniz A1 - Adkins, Jess F. A1 - Haug, Gerald T1 - Climatic and in-cave influences on delta O-18 and delta C-13 in a stalagmite from northeastern India through the last deglaciation JF - Quaternary research : an interdisciplinary journal N2 - Northeastern (NE) India experiences extraordinarily pronounced seasonal climate, governed by the Indian summer monsoon (ISM). The vulnerability of this region to floods and droughts calls for detailed and highly resolved paleoclimate reconstructions to assess the recurrence rate and driving factors of ISM changes. We use stable oxygen and carbon isotope ratios (delta O-18 and delta C-13) from stalagmite MAW-6 from Mawmluh Cave to infer climate and environmental conditions in NE India over the last deglaciation (16-6ka). We interpret stalagmite delta O-18 as reflecting ISM strength, whereas delta C-13 appears to be driven by local hydroclimate conditions. Pronounced shifts in ISM strength over the deglaciation are apparent from the delta O-18 record, similarly to other records from monsoonal Asia. The ISM is weaker during the late glacial (LG) period and the Younger Dryas, and stronger during the BOlling-Allerod and Holocene. Local conditions inferred from the delta C-13 record appear to have changed less substantially over time, possibly related to the masking effect of changing precipitation seasonality. Time series analysis of the delta O-18 record reveals more chaotic conditions during the late glacial and higher predictability during the Holocene, likely related to the strengthening of the seasonal recurrence of the ISM with the onset of the Holocene. KW - Indian Summer Monsoon KW - stalagmite KW - oxygen isotopes KW - carbon isotopes KW - deglaciation Y1 - 2017 U6 - https://doi.org/10.1017/qua.2017.72 SN - 0033-5894 SN - 1096-0287 VL - 88 SP - 458 EP - 471 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Dahm, Torsten A1 - Stiller, Manfred A1 - Mechie, James A1 - Heimann, Sebastian A1 - Hensch, Martin A1 - Woith, Heiko A1 - Schmidt, Bernd A1 - Gabriel, Gerald A1 - Weber, Michael T1 - Seismological and geophysical signatures of the deep crustal magma systems of the cenozoic volcanic fields Beneath the Eifel, Germany JF - Geochemistry, geophysics, geosystems N2 - The Quaternary volcanic fields of the Eifel (Rhineland-Palatinate, Germany) had their last eruptions less than 13,000 years ago. Recently, deep low-frequency (DLF) earthquakes were detected beneath one of the volcanic fields showing evidence of ongoing magmatic activity in the lower crust and upper mantle. In this work, seismic wide- and steep-angle experiments from 1978/1979 and 1987/1988 are compiled, partially reprocessed and interpreted, together with other data to better determine the location, size, shape, and state of magmatic reservoirs in the Eifel region near the crust-mantle boundary. We discuss seismic evidence for a low-velocity gradient layer from 30-36 km depth, which has developed over a large region under all Quaternary volcanic fields of the Rhenish Massif and can be explained by the presence of partial melts. We show that the DLF earthquakes connect the postulated upper mantle reservoir with the upper crust at a depth of about 8 km, directly below one of the youngest phonolitic volcanic centers in the Eifel, where CO(2)originating from the mantle is massively outgassing. A bright spot in the West Eifel between 6 and 10 km depth represents a Tertiary magma reservoir and is seen as a model for a differentiated reservoir beneath the young phonolitic center today. We find that the distribution of volcanic fields is controlled by the Variscan lithospheric structures and terrane boundaries as a whole, which is reflected by an offset of the Moho depth, a wedge-shaped transparent zone in the lower crust and the system of thrusts over about 120 km length. KW - magma reservoirs KW - distributed volcanic fields KW - reflection seismic KW - crustal magma chamber KW - deep low-frequency earthquakes KW - low velocity zone Y1 - 2020 U6 - https://doi.org/10.1029/2020GC009062 SN - 1525-2027 VL - 21 IS - 9 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Hensch, Martin A1 - Dahm, Torsten A1 - Ritter, Joachim A1 - Heimann, Sebastian A1 - Schmidt, Bernd A1 - Stange, Stefan A1 - Lehmann, Klaus T1 - Deep low-frequency earthquakes reveal ongoing magmatic recharge beneath Laacher See Volcano (Eifel, Germany) JF - Geophysical journal international N2 - The occurrence of deep low-frequency (DLF) microearthquakes beneath volcanoes is commonly attributed to mass transport in the volcanic plumbing system and used to infer feeding channels from and into magma reservoirs. The key question is how magmas migrate from depth to the shallow crust and whether magma reservoirs are currently being recharged. For the first time since the improvement of the local seismic networks in the East Eifel region (Rhineland-Palatinate, Germany), we detect and locate recurrent DLF earthquakes in the lower crust and upper mantle beneath the Laacher See Volcano (LSV), using a joint data set of permanent sensors and a temporary deployment. So far, eight DLF earthquake sequences were observed in four distinct clusters between 10 and 40 km depth. These clusters of weak events (M-L< 2) align along an approximately 80. southeast dipping line south of the LSV. Moment tensor solutions of these events have large shear components, and the irregular dispersion and long coda of body waves indicate interaction processes between shear cracks and fluids. We find a rotation of P-axes orientation for shallow tectonic earthquakes compared to DLF events, indicating that the stress field in the depth interval of DLF events might favour a vertical migration of magma or magmatic fluids. The caldera of the LSV was formed by the last major eruption of the East Eifel Volcanic Field only 12.9 kyr ago, fed by a shallow magma chamber at 5-8 km depth and erupting a total magma volume of 6.7 km(3). The observed DLF earthquake activity and continuous volcanic gas emissions around the LSV indicate an active magmatic system, possibly connected with an upper mantle melt zone. KW - Waveform inversion KW - Volcano seismology KW - Magma migration and fragmentation KW - Volcano monitoring Y1 - 2019 U6 - https://doi.org/10.1093/gji/ggy532 SN - 0956-540X SN - 1365-246X VL - 216 IS - 3 SP - 2025 EP - 2036 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Fondell, Mattis A1 - Eckert, Sebastian A1 - Jay, Raphael Martin A1 - Weniger, Christian A1 - Quevedo, Wilson A1 - Niskanen, Johannes A1 - Kennedy, Brian A1 - Sorgenfrei, Nomi A1 - Schick, Daniel A1 - Giangrisostomi, Erika A1 - Ovsyannikov, Ruslan A1 - Adamczyk, Katrin A1 - Huse, Nils A1 - Wernet, Philippe A1 - Mitzner, Rolf A1 - Föhlisch, Alexander T1 - Time-resolved soft X-ray absorption spectroscopy in transmission mode on liquids at MHz repetition rates T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - We present a setup combining a liquid flatjet sample delivery and a MHz laser system for time-resolved soft X-ray absorption measurements of liquid samples at the high brilliance undulator beamline UE52-SGM at Bessy II yielding unprecedented statistics in this spectral range. We demonstrate that the efficient detection of transient absorption changes in transmission mode enables the identification of photoexcited species in dilute samples. With iron(II)-trisbipyridine in aqueous solution as a benchmark system, we present absorption measurements at various edges in the soft X-ray regime. In combination with the wavelength tunability of the laser system, the set-up opens up opportunities to study the photochemistry of many systems at low concentrations, relevant to materials sciences, chemistry, and biology. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 780 KW - l-edge xas KW - electronic-structure KW - molecular-structure KW - spin-state KW - dynamics KW - complexes KW - probe KW - water KW - iron(II) KW - spectra Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437529 SN - 1866-8372 IS - 780 ER - TY - CHAP A1 - Esveld, Selma van A1 - Vries, Nardo de A1 - Becchetti, Sibilla A1 - Dopper, Sofia A1 - Valkenburg, Willem van A1 - Carlon, May Kristine Jonson A1 - Yokoi, Kensuke A1 - Gayed, John Maurice A1 - Suyama, Hiroshi A1 - Cross, Jeffrey Scott A1 - Jin, Tonje A1 - Xue, Wei A1 - Bruillard, Éric A1 - Steinbeck, Hendrik A1 - Meinel, Christoph A1 - Özdemir, Paker Doğu A1 - Can Bayer, Burak A1 - Mercan, Duygu A1 - Buyurucu, Gamze A1 - Haugsbakken, Halvdan A1 - Hagelia, Marianne A1 - Ebner, Martin A1 - Edelsbrunner, Sarah A1 - Hohla-Sejkora, Katharina A1 - Lipp, Silvia A1 - Schön, Sandra A1 - Xiaoxiao, Wang A1 - Shuangshuang, Guo A1 - Morales-Chan, Miguel A1 - Amado-Salvatierra, Héctor R. A1 - Hernández-Rizzardini, Rocael A1 - Egloffstein, Marc A1 - Hünemohr, Holger A1 - Ifenthaler, Dirk A1 - Dixon, Fred A1 - Trabucchi, Stefania A1 - Khaneboubi, Mehdi A1 - Giannatelli, Ada A1 - Tomasini, Alessandra A1 - Staubitz, Thomas A1 - Serth, Sebastian A1 - Thomas, Max A1 - Koschutnig-Ebner, Markus A1 - Rampelt, Florian A1 - Stetten, Alexander von A1 - Wittke, Andreas A1 - Theeraroungchaisri, Anuchai A1 - Thammetar, Thapanee A1 - Duangchinda, Vorasuang A1 - Khlaisang, Jintavee A1 - Mair, Bettina A1 - Steinkellner, Iris A1 - Stojcevic, Ivana A1 - Zwiauer, Charlotte A1 - Thirouard, Maria A1 - Villèsbrunne, Marie de la A1 - Bernaert, Oliver A1 - Nohr, Magnus A1 - Alario Hoyos, Carlos A1 - Delgado Kloos, Carlos A1 - Kiendl, Doris A1 - Terzieva, Liliya A1 - Concia, Francesca A1 - Distler, Petr A1 - Law, Gareth A1 - Macerata, Elena A1 - Mariani, Mario A1 - Mossini, Eros A1 - Negrin, Maddalena A1 - Štrok, Marko A1 - Neuböck, Kristina A1 - Linschinger, Nadine A1 - Lorenz, Anja A1 - Bock, Stefanie A1 - Schulte-Ostermann, Juleka A1 - Moura Santos, Ana A1 - Corti, Paola A1 - Costa, Luis Felipe Coimbra A1 - Utunen, Heini A1 - Attias, Melissa A1 - Tokar, Anna A1 - Kennedy, Eileen A1 - Laurillard, Diana A1 - Zeitoun, Samar A1 - Wasilewski, Julie A1 - Shlaka, Souhad A1 - Ouahib, Sara A1 - Berrada, Khalid A1 - Dietz, Michael A1 - Roth, Dennis ED - Meinel, Christoph ED - Schweiger, Stefanie ED - Staubitz, Thomas ED - Conrad, Robert ED - Alario Hoyos, Carlos ED - Ebner, Martin ED - Sancassani, Susanna ED - Żur, Agnieszka ED - Friedl, Christian ED - Halawa, Sherif ED - Gamage, Dilrukshi ED - Cross, Jeffrey ED - Jonson Carlon, May Kristine ED - Deville, Yves ED - Gaebel, Michael ED - Delgado Kloos, Carlos ED - von Schmieden, Karen T1 - EMOOCs 2023 BT - Post-Covid Prospects for Massive Open Online Courses - Boost or Backlash? N2 - From June 14 to June 16, 2023, Hasso Plattner Institute, Potsdam, hosted the eighth European MOOC Stakeholder Summit (EMOOCs 2023). The pandemic is fortunately over. It has once again shown how important digital education is. How well-prepared a country was could be seen in our schools, universities, and companies. In different countries, the problems manifested themselves differently. The measures and approaches to solving the problems varied accordingly. Digital education, whether micro-credentials, MOOCs, blended learning formats, or other e-learning tools, received a major boost. EMOOCs 2023 focusses on the effects of this emergency situation. How has it affected the development and delivery of MOOCs and other e-learning offerings all over Europe? Which projects can serve as models for successful digital learning and teaching? Which roles can MOOCs and micro-credentials bear in the current business transformation? Is there a backlash to the routine we knew from pre-Corona times? Or have many things become firmly established in the meantime, e.g. remote work, hybrid conferences, etc.? Furthermore, EMOOCs 2023 has a closer look at the development and formalization of digital learning. Micro-credentials are just the starting point. Further steps in this direction would be complete online study programs or full online universities. Another main topic is the networking of learning offers and the standardization of formats and metadata. Examples of fruitful cooperations are the MOOChub, the European MOOC Consortium, and the Common Micro-Credential Framework. The learnings, derived from practical experience and research, are explored in EMOOCs 2023 in four tracks and additional workshops, covering various aspects of this field. In this publication, we present papers from the conference’s Research & Experience Track, the Business Track and the International Track. N2 - Vom 14. bis 16. Juni 2023 fand am Hasso-Plattner-Institut in Potsdam der achte European MOOC Stakeholder Summit (EMOOCs 2023) statt. Die Pandemie ist zum Glück vorbei. Sie hat einmal mehr gezeigt, wie wichtig digitale Bildung ist. Wie gut ein Land darauf vorbereitet war, zeigte sich in unseren Schulen, Universitäten und Unternehmen. In den verschiedenen Ländern haben sich die Probleme unterschiedlich manifestiert. Entsprechend unterschiedlich waren auch die Maßnahmen und Lösungsansätze. Die digitale Bildung, ob Micro-Credentials, MOOCs, Blended-Learning-Formate oder andere E-Learning-Tools, erhielt einen großen Schub. EMOOCs 2023 befasst sich mit den Auswirkungen dieser Notsituation. Wie hat sie die Entwicklung und Bereitstellung von MOOCs und anderen E-Learning-Angeboten in ganz Europa beeinflusst? Welche Projekte können als Modelle für erfolgreiches digitales Lernen und Lehren dienen? Welche Rolle können MOOCs und Micro-Credentials bei der aktuellen Transformation der Wirtschaft spielen? Gibt es eine Rückbesinnung auf die Routine, die wir aus der Zeit vor Corona kennen? Oder haben sich viele Dinge inzwischen fest etabliert, z.B. Remote Work, hybride Konferenzen, etc. Darüber hinaus wirft EMOOCs 2023 einen genaueren Blick auf die Entwicklung und Formalisierung des digitalen Lernens. Microcredentials sind nur der Anfang. Weitere Schritte in diese Richtung wären komplette Online-Studiengänge oder vollständige Online-Universitäten. Ein weiteres Schwerpunktthema ist die Vernetzung von Lernangeboten und die Standardisierung von Formaten und Metadaten. Beispiele für fruchtbare Kooperationen sind der MOOChub, das European MOOC Consortium und das Common Micro-Credential Framework. Die aus der Praxis und der Forschung gewonnenen Erkenntnisse werden auf der EMOOCs 2023 in vier Tracks und zusätzlichen Workshops zu verschiedenen Aspekten des Themas vertieft. In dieser Publikation stellen wir Beiträge aus dem Research & Experience Track, dem Business Track und dem International Track vor. KW - MOOC KW - digital education KW - e-learning KW - online course design KW - online course creation KW - micro-credential KW - micro degree KW - online teaching KW - MOOC KW - Onlinekurs KW - Digitale Bildung KW - Online-Lehre KW - Kursdesign KW - Onlinekurs-Produktion KW - Micro Degree Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-576450 ER - TY - THES A1 - Breitenbach, Sebastian Franz Martin T1 - Changes in monsoonal precipitation and atmospheric circulation during the Holocene reconstructed from stalagmites from Northeastern India T1 - Veränderungen monsunalen Niederschlages und atmosphärischer Zirkulation während des Holozäns, rekonstruiert aus Stalagmiten aus Nordostindien N2 - Recent years witnessed a vast advent of stalagmites as palaeoclimate archives. The multitude of geochemical and physical proxies and a promise of a precise and accurate age model greatly appeal to palaeoclimatologists. Although substantial progress was made in speleothem-based palaeoclimate research and despite high-resolution records from low-latitudinal regions, proving that palaeo-environmental changes can be archived on sub-annual to millennial time scales our comprehension of climate dynamics is still fragmentary. This is in particular true for the summer monsoon system on the Indian subcontinent. The Indian summer monsoon (ISM) is an integral part of the intertropical convergence zone (ITCZ). As this rainfall belt migrates northward during boreal summer, it brings monsoonal rainfall. ISM strength depends however on a variety of factors, including snow cover in Central Asia and oceanic conditions in the Indic and Pacific. Presently, many of the factors influencing the ISM are known, though their exact forcing mechanism and mutual relations remain ambiguous. Attempts to make an accurate prediction of rainfall intensity and frequency and drought recurrence, which is extremely important for South Asian countries, resemble a puzzle game; all interaction need to fall into the right place to obtain a complete picture. My thesis aims to create a faithful picture of climate change in India, covering the last 11,000 ka. NE India represents a key region for the Bay of Bengal (BoB) branch of the ISM, as it is here where the monsoon splits into a northwestward and a northeastward directed arm. The Meghalaya Plateau is the first barrier for northward moving air masses and receives excessive summer rainfall, while the winter season is very dry. The proximity of Meghalaya to the Tibetan Plateau on the one hand and the BoB on the other hand make the study area a key location for investigating the interaction between different forcings that governs the ISM. A basis for the interpretation of palaeoclimate records, and a first important outcome of my thesis is a conceptual model which explains the observed pattern of seasonal changes in stable isotopes (d18O and d2H) in rainfall. I show that although in tropical and subtropical regions the amount effect is commonly called to explain strongly depleted isotope values during enhanced rainfall, alone it cannot account for observed rainwater isotope variability in Meghalaya. Monitoring of rainwater isotopes shows no expected negative correlation between precipitation amount and d18O of rainfall. In turn I find evidence that the runoff from high elevations carries an inherited isotopic signature into the BoB, where during the ISM season the freshwater builds a strongly depleted plume on top of the marine water. The vapor originating from this plume is likely to memorize' and transmit further very negative d18O values. The lack of data does not allow for quantication of this plume effect' on isotopes in rainfall over Meghalaya but I suggest that it varies on seasonal to millennial timescales, depending on the runoff amount and source characteristics. The focal point of my thesis is the extraction of climatic signals archived in stalagmites from NE India. High uranium concentration in the stalagmites ensured excellent age control required for successful high-resolution climate reconstructions. Stable isotope (d18O and d13C) and grey-scale data allow unprecedented insights into millennial to seasonal dynamics of the summer and winter monsoon in NE India. ISM strength (i. e. rainfall amount) is recorded in changes in d18Ostalagmites. The d13C signal, reflecting drip rate changes, renders a powerful proxy for dry season conditions, and shows similarities to temperature-related changes on the Tibetan Plateau. A sub-annual grey-scale profile supports a concept of lower drip rate and slower stalagmite growth during dry conditions. During the Holocene, ISM followed a millennial-scale decrease of insolation, with decadal to centennial failures resulting from atmospheric changes. The period of maximum rainfall and enhanced seasonality corresponds to the Holocene Thermal Optimum observed in Europe. After a phase of rather stable conditions, 4.5 kyr ago, the strengthening ENSO system dominated the ISM. Strong El Nino events weakened the ISM, especially when in concert with positive Indian Ocean dipole events. The strongest droughts of the last 11 kyr are recorded during the past 2 kyr. Using the advantage of a well-dated stalagmite record at hand I tested the application of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to detect sub-annual to sub-decadal changes in element concentrations in stalagmites. The development of a large ablation cell allows for ablating sample slabs of up to 22 cm total length. Each analyzed element is a potential proxy for different climatic parameters. Combining my previous results with the LAICP- MS-generated data shows that element concentration depends not only on rainfall amount and associated leaching from the soil. Additional factors, like biological activity and hydrogeochemical conditions in the soil and vadose zone can eventually affect the element content in drip water and in stalagmites. I present a theoretical conceptual model for my study site to explain how climatic signals can be transmitted and archived in stalagmite carbonate. Further, I establish a first 1500 year long element record, reconstructing rainfall variability. Additionally, I hypothesize that volcanic eruptions, producing large amounts of sulfuric acid, can influence soil acidity and hence element mobilization. N2 - Stalagmiten erfuhren in den letzten Jahren vermehrt Aufmerksamkeit als bedeutende Paläoklima- Archive. Paläoklimatologen sind beeindruckt von der grossen Zahl geochemischer und physikalischer Indikatoren (Proxies) und der Möglichkeit, präzise absolute Altersmodelle zu erstellen. Doch obwohl substantielle Fortschritte in der speleothem-basierten Klimaforschung gemacht wurden, und trotz hochaufgelöster Archive aus niederen Breiten, welche zeigen, das Umweltveränderungen auf Zeitskalen von Jahren bis Jahrtausenden archiviert und rekonstruiert werden können, bleibt unser Verständnis der Klimadynamik fragmentarisch. Ganz besonders gilt dies für den Indischen Sommermonsun (ISM) auf dem Indischen Subkontinent. Der ISM ist heute als ein integraler Bestandteil der intertropischen Konvergenzzone verstanden. Sobald dieser Regengürtel während des borealen Sommer nordwärts migriert kann der ISM seine feuchten Luftmassen auf dem Asiatischen Festland entladen. Dabei hängt die Stärke des ISM von einer Vielzahl von Faktoren ab. Zu diesen gehören die Schneedicke in Zentralasien im vorhergehenden Winter und ozeanische Bedingungen im Indischen und Pazifschen Ozean. Heute sind viele dieser Faktoren bekannt. Trotzdem bleiben deren Mechanismen und internen Verbindungen weiterhin mysteriös. Versuche, korrekte Vorhersagen zu Niederschlagsintensität und Häufigkeit oder zu Dürreereignissen zu erstellen ähneln einem Puzzle. All die verschiedenen Interaktionen müssen an die richtige Stelle gelegt werden, um ein sinnvolles Bild entstehen zu lassen. Meine Dissertation versucht, ein vertrauenswürdiges Bild des sich wandelnden Holozänen Klimas in Indien zu erstellen. NE Indien ist eine Schlüsselregion für den östlichen Arm des ISM, da sich hier der ISM in zwei Arme aufteilt, einen nordwestwärts und einen nordostwärts gerichteten. Das Meghalaya Plateau ist das erste Hindernis für die sich nordwärts bewegenden Luftmassen und erhält entsprechend exzessive Niederschläge während des Sommers. Die winterliche Jahreszeit dagegen ist sehr trocken. Die Nähe zum Tibetplateau einerseits und der Bucht von Bengalen andererseits determinieren die Schlüsselposition dieser Region für das Studium der Interaktionen der den ISM beeinflussenden Kräfte. Ein Fundament für die Interpretation der Paläoklimarecords und ein erstes wichtiges Ergebnis meiner Arbeit ist ein konzeptuelles Modell, welches die beobachteten saisonalen Veränderungen stabiler Isotope (d18O und d2H) im Niederschlag erklärt. Ich zeige, das obwohl in tropischen und subtropischen Regionen meist der amount effect zur Erklärung stark negativer Isotopenwerte während starker Niederschläge herangezogen wird, dieser allein nicht ausreicht, um die Isotopenvariabilität im Niederschlag Meghalaya's zu erklären. Die Langzeitbeobachtung der Regenwasserisotopie zeigt keine negative Korrelation zwischen Niederschlagsmenge und d18O. Es finden sich Hinweise, das der Abfluss aus den Hochgebirgsregionen Tibets und des Himalaya eine Isotopensignatur an das Oberflächenwasser der Bucht von Bengalen vererbt. Dort bildet sich aus isotopisch stark abgereicherten Wässern während des ISM eine Süsswasserlinse aus. Es ist wahrscheinlich, das Wasserdampf, der aus dieser Linse stammt, ein Isotopensignal aufgeprägt bekommt, welches abgereichertes d18O weitertransportiert. Der Mangel an Daten lässt es bisher leider nicht zu, quantitative Aussagen über den Einfluss dieses plume effect' auf Niederschläge in Meghalaya zu treffen. Es lässt sich allerdings vermuten, das dieser Einfluss auf saisonalen wie auch auf langen Zeitskalen variabel ist, abhängig vom Abfluss und der Quellencharacteristik. Der Fokus meiner Arbeit liegt in der Herauslösung klimatischer Signale aus nordostindischen Stalagmiten. Hohe Urankonzentrationen in diesen Stalagmiten erlaubt eine exzellente Alterskontrolle, die für hochauflösende Klimarekonstruktionen unerlässlich ist. Die stabilen Isotope (d18O und d13C), sowie Grauwertdaten, erlauben einmalige Einblicke in die Dynamik des Sommer und auch des Wintermonsun in NE Indien. Die ISM Stärke (d. h. Niederschlagsmenge) wird in Veränderungen in den d18Ostalagmites reflektiert. Das d13C Signal, welches Tropfratenänderungen speichert, dient als potenter Indikator für winterliche Trockenheitsbedingungen. Es zeigt Ähnlichkeit zu temperaturabhängigen Veränderungen auf dem Tibetplateau. Das sub-annuell aufgelöste Grauwertprofil stärkt das Konzept, das verminderte Tropfraten und langsameres Stalagmitenwachstum eine Folge von Trockenheit sind. Während des Holozäns folgte der ISM der jahrtausendelangen Verringerung der Insolation. Es finden sich aber ebenso rapide Anomalien, die aus atmosphärischen Veränderungen resultieren. Die Phase des höchsten Niederschlages und erhöhter Saisonalität korrespondiert mit dem Holozänen Thermalen Maximum. Nach einer Phase einigermassen stabilen Bedingungen begann vor ca. 4500 Jahren ENSO einen zunehmenden Einfluss auf den ISM auszuüben. Starke El Nino Ereignisse schwächen den ISM, besonders wenn diese zeitgleich mit positiven Indian Ocean Dipole Ereignissen auftreten. Die stärksten Dürren des gesamten Holozäns traten in den letzten 2000 Jahren auf. Um zusätzliche Informationen aus den hervorragenden Proben zu gewinnen nutzte ich die Vorteile der laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Diese erlaubt die Detektion sub-annueller bis sub-dekadischer Elementkonzentrationsveränderungen in Stalagmiten. Mittels einer neu entwickelten Ablationszelle konnten Proben von maximal 22 cm Länge untersucht werden. Jedes analysierte Element ist ein potentieller Träger einer Klimainformation. Die Kombination der früheren Ergebnisse mit denen der LA-IPC-MS zeigt, das die Elementkonzentrationen nicht nur von Niederschlagsveränderungen und assoziiertem Auswaschen aus dem Boden abhängen. Zusätzlich können auch die biologische Aktivität und hydrogeochemische Bedingungen in der vadosen Zone Einfluss auf die Elementzusammensetzung im Tropfwasser und in den Stalagmiten haben. Darum entwickelte ich ein theoretisches Modell für meinen Standort, um zu klären, wie Klimasignale von der Atmosphäre in die Höhle transportiert werden können. Ein anschliessend rekonstruierter 1500 Jahre langer Proxyrecord zeigt Niederschlagsvariabilität an. Zudem besteht die Möglichkeit, das Vulkaneruptionen, welche grosse Mengen an Schwefelsäure produzieren, eine Bodenversauerung verursachen und damit die Elementmobilisierung verstärken können. KW - Indischer Sommermonsun KW - Stabile Isotope KW - Stalagmiten KW - Holozän KW - Bucht von Bengalen KW - Indian Summer Monsoon KW - Bay of Bengal KW - stable isotopes KW - stalagmites KW - Laser ablation Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-37807 ER - TY - GEN A1 - Dallmeyer, Anne A1 - Claussen, Martin A1 - Ni, Jian A1 - Cao, Xianyong A1 - Wang, Yongbo A1 - Fischer, Nils A1 - Pfeiffer, Madlene A1 - Jin, Liya A1 - Khon, Vyacheslav A1 - Wagner, Sebastian A1 - Haberkorn, Kerstin A1 - Herzschuh, Ulrike T1 - Biome changes in Asia since the mid-Holocene BT - An analysis of different transient Earth system model simulations T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - The large variety of atmospheric circulation systems affecting the eastern Asian climate is reflected by the complex Asian vegetation distribution. Particularly in the transition zones of these circulation systems, vegetation is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate-vegetation relationship is lacking. To assess the Holocene vegetation change and to obtain an ensemble of potential mid-Holocene biome distributions for eastern Asia, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient Holocene climate simulations performed in coupled atmosphere-ocean(-vegetation) models. The simulated biome changes are compared with pollen-based biome records for different key regions. In all simulations, substantial biome shifts during the last 6000 years are confined to the high northern latitudes and the monsoon-westerly wind transition zone, but the temporal evolution and amplitude of change strongly depend on the climate forcing. Large parts of the southern tundra are replaced by taiga during the mid-Holocene due to a warmer growing season and the boreal treeline in northern Asia is shifted northward by approx. 4 degrees in the ensemble mean, ranging from 1.5 to 6 degrees in the individual simulations, respectively. This simulated treeline shift is in agreement with pollen-based reconstructions from northern Siberia. The desert fraction in the transition zone is reduced by 21% during the mid-Holocene compared to pre-industrial due to enhanced precipitation. The desert-steppe margin is shifted westward by 5 degrees (1-9 degrees in the individual simulations). The forest biomes are expanded north-westward by 2 degrees, ranging from 0 to 4 degrees in the single simulations. These results corroborate pollen-based reconstructions indicating an extended forest area in north-central China during the mid-Holocene. According to the model, the forest-to-non-forest and steppe-to-desert changes in the climate transition zones are spatially not uniform and not linear since the mid-Holocene. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 643 KW - Last Glacial Maximum KW - Eastern Continental Asia KW - summer monsoon precipitation KW - PMIP2 coupled simulations KW - Global Vegetation Model KW - northern high‐latitudes KW - Holocene climate change KW - Tibetan Plateau KW - environmental changes KW - Inner Mongolia Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-418755 SN - 1866-8372 IS - 643 SP - 107 EP - 134 ER - TY - JOUR A1 - Dallmeyer, Anne A1 - Claussen, Martin A1 - Ni, Jian A1 - Cao, Xianyong A1 - Wang, Yongbo A1 - Fischer, Nils A1 - Pfeiffer, Madlene A1 - Jin, Liya A1 - Khon, Vyacheslav A1 - Wagner, Sebastian A1 - Haberkorn, Kerstin A1 - Herzschuh, Ulrike T1 - Biome changes in Asia since the mid-Holocene BT - an analysis of different transient Earth system model simulations JF - Climate of the past : an interactive open access journal of the European Geosciences Union N2 - The large variety of atmospheric circulation systems affecting the eastern Asian climate is reflected by the complex Asian vegetation distribution. Particularly in the transition zones of these circulation systems, vegetation is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate-vegetation relationship is lacking. To assess the Holocene vegetation change and to obtain an ensemble of potential mid-Holocene biome distributions for eastern Asia, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient Holocene climate simulations performed in coupled atmosphere-ocean(-vegetation) models. The simulated biome changes are compared with pollen-based biome records for different key regions. In all simulations, substantial biome shifts during the last 6000 years are confined to the high northern latitudes and the monsoon-westerly wind transition zone, but the temporal evolution and amplitude of change strongly depend on the climate forcing. Large parts of the southern tundra are replaced by taiga during the mid-Holocene due to a warmer growing season and the boreal treeline in northern Asia is shifted northward by approx. 4 degrees in the ensemble mean, ranging from 1.5 to 6 degrees in the individual simulations, respectively. This simulated treeline shift is in agreement with pollen-based reconstructions from northern Siberia. The desert fraction in the transition zone is reduced by 21% during the mid-Holocene compared to pre-industrial due to enhanced precipitation. The desert-steppe margin is shifted westward by 5 degrees (1-9 degrees in the individual simulations). The forest biomes are expanded north-westward by 2 degrees, ranging from 0 to 4 degrees in the single simulations. These results corroborate pollen-based reconstructions indicating an extended forest area in north-central China during the mid-Holocene. According to the model, the forest-to-non-forest and steppe-to-desert changes in the climate transition zones are spatially not uniform and not linear since the mid-Holocene. Y1 - 2017 U6 - https://doi.org/10.5194/cp-13-107-2017 SN - 1814-9324 SN - 1814-9332 VL - 13 IS - 2 SP - 107 EP - 134 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Pontius, Niko A1 - Beye, Martin A1 - Trabant, Christoph A1 - Mitzner, Rolf A1 - Sorgenfrei, Nomi A1 - Kachel, Torsten A1 - Woestmann, Michael A1 - Roling, Sebastian A1 - Zacharias, Helmut A1 - Ivanov, Rosen A1 - Treusch, Rolf A1 - Buchholz, Marcel A1 - Metcalf, Pete A1 - Schuessler-Langeheine, Christian A1 - Föhlisch, Alexander T1 - Probing the non-equilibrium transient state in magnetite by a jitter-free two-color X-ray pump and X-ray probe experiment JF - Structural dynamics N2 - We present a general experimental concept for jitter-free pump and probe experiments at free electron lasers. By generating pump and probe pulse from one and the same X-ray pulse using an optical split-and-delay unit, we obtain a temporal resolution that is limited only by the X-ray pulse lengths. In a two-color X-ray pump and X-ray probe experiment with sub 70 fs temporal resolution, we selectively probe the response of orbital and charge degree of freedom in the prototypical functional oxide magnetite after photoexcitation. We find electronic order to be quenched on a time scale of (30 +/- 30) fs and hence most likely faster than what is to be expected for any lattice dynamics. Our experimental result hints to the formation of a short lived transient state with decoupled electronic and lattice degree of freedom in magnetite. The excitation and relaxation mechanism for X-ray pumping is discussed within a simple model leading to the conclusion that within the first 10 fs the original photoexcitation decays into low-energy electronic excitations comparable to what is achieved by optical pump pulse excitation. Our findings show on which time scales dynamical decoupling of degrees of freedom in functional oxides can be expected and how to probe this selectively with soft X-ray pulses. Results can be expected to provide crucial information for theories for ultrafast behavior of materials and help to develop concepts for novel switching devices. (C) 2018 Author(s). Y1 - 2018 U6 - https://doi.org/10.1063/1.5042847 SN - 2329-7778 VL - 5 IS - 5 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Fondell, Mattis A1 - Eckert, Sebastian A1 - Jay, Raphael Martin A1 - Weniger, Christian A1 - Quevedo, Wilson A1 - Niskanen, Johannes A1 - Kennedy, Brian A1 - Sorgenfrei, Nomi A1 - Schick, Daniel A1 - Giangrisostomi, Erika A1 - Ovsyannikov, Ruslan A1 - Adamczyk, Katrin A1 - Huse, Nils A1 - Wernet, Philippe A1 - Mitzner, Rolf A1 - Föhlisch, Alexander T1 - Time-resolved soft X-ray absorption spectroscopy in transmission mode on liquids at MHz repetition rates JF - Structural dynamics N2 - We present a setup combining a liquid flatjet sample delivery and a MHz laser system for time-resolved soft X-ray absorption measurements of liquid samples at the high brilliance undulator beamline UE52-SGM at Bessy II yielding unprecedented statistics in this spectral range. We demonstrate that the efficient detection of transient absorption changes in transmission mode enables the identification of photoexcited species in dilute samples. With iron(II)-trisbipyridine in aqueous solution as a benchmark system, we present absorption measurements at various edges in the soft X-ray regime. In combination with the wavelength tunability of the laser system, the set-up opens up opportunities to study the photochemistry of many systems at low concentrations, relevant to materials sciences, chemistry, and biology. (C) 2017 Author(s). Y1 - 2017 U6 - https://doi.org/10.1063/1.4993755 SN - 2329-7778 VL - 4 PB - American Institute of Physics CY - Melville ER -