TY  - JOUR
A1  - Pontius, Niko
A1  - Beye, Martin
A1  - Trabant, Christoph
A1  - Mitzner, Rolf
A1  - Sorgenfrei, Florian
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  - Zeeden, Christian
A1  - Obreht, Igor
A1  - Veres, Daniel
A1  - Kaboth-Bahr, Stefanie
A1  - Hošek, Jan
A1  - Marković, Slobodan B.
A1  - Bösken, Janina
A1  - Lehmkuhl, Frank
A1  - Rolf, Christian
A1  - Hambach, Ulrich
T1  - Smoothed millennial-scale palaeoclimatic reference data as unconventional comparison targets: Application to European loess records
JF  - Scientific Reports
N2  - Millennial-scale palaeoclimate variability has been documented in various terrestrial and marine palaeoclimate proxy records throughout the Northern Hemisphere for the last glacial cycle. Its clear expression and rapid shifts between different states of climate (Greenland Interstadials and Stadials) represents a correlation tool beyond the resolution of e.g. luminescence dating, especially relevant for terrestrial deposits. Usually, comparison of terrestrial proxy datasets and the Greenland ice cores indicates a complex expression of millennial-scale climate variability as recorded in terrestrial geoarchives including loess. Loess is the most widespread terrestrial geoarchive of the Quaternary and especially widespread over Eurasia. However, loess often records a smoothed representation of millennial-scale variability without all fidelity when compared to the Greenland data, this being a relevant limiting feature in integrating loess with other palaeoclimate records. To better understand the loess proxy-response to millennial-scale climate variability, we simulate a proxy signal smoothing by natural processes through application of low-pass filters of delta O-18 data from Greenland, a high-resolution palaeoclimate reference record, alongside speleothem isotope records from the Black Sea-Mediterranean region. We show that low-pass filters represent rather simple models for better constraining the expression of millennial-scale climate variability in low sedimentation environments, and in sediments where proxy-response signals are most likely affected by natural smoothing (by e.g. bioturbation). Interestingly, smoothed datasets from Greenland and the Black Sea-Mediterranean region are most similar in the last similar to 15 ka and between similar to 50-30 ka. Between similar to 30-15 ka, roughly corresponding to the Last Glacial Maximum and the deglaciation, the records show dissimilarities, challenging the construction of robust correlative time-scales in this age range. From our analysis it becomes apparent that patterns of palaeoclimate signals in loess-palaeosol sequences often might be better explained by smoothed Greenland reference data than the original high-resolution Greenland dataset, or other reference data. This opens the possibility to better assess the temporal resolution and palaeoclimate potential of loess-palaeosol sequences in recording supra-regional climate patterns, as well as to securely integrate loess with other chronologically better-resolved palaeoclimate records.
KW  - last glacial period
KW  - Western Interior Basin
KW  - high-resolution record
KW  - Greenland ice cores
KW  - paleosol sequence
KW  - time-scale
KW  - Chinese loess
KW  - astronomical calibration
KW  - chronology (AICC2012)
KW  - Antarctic ice
Y1  - 2020
VL  - 10
IS  - 1
PB  - Springer Nature
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Arnison, Paul G.
A1  - Bibb, Mervyn J.
A1  - Bierbaum, Gabriele
A1  - Bowers, Albert A.
A1  - Bugni, Tim S.
A1  - Bulaj, Grzegorz
A1  - Camarero, Julio A.
A1  - Campopiano, Dominic J.
A1  - Challis, Gregory L.
A1  - Clardy, Jon
A1  - Cotter, Paul D.
A1  - Craik, David J.
A1  - Dawson, Michael
A1  - Dittmann-Thünemann, Elke
A1  - Donadio, Stefano
A1  - Dorrestein, Pieter C.
A1  - Entian, Karl-Dieter
A1  - Fischbach, Michael A.
A1  - Garavelli, John S.
A1  - Goeransson, Ulf
A1  - Gruber, Christian W.
A1  - Haft, Daniel H.
A1  - Hemscheidt, Thomas K.
A1  - Hertweck, Christian
A1  - Hill, Colin
A1  - Horswill, Alexander R.
A1  - Jaspars, Marcel
A1  - Kelly, Wendy L.
A1  - Klinman, Judith P.
A1  - Kuipers, Oscar P.
A1  - Link, A. James
A1  - Liu, Wen
A1  - Marahiel, Mohamed A.
A1  - Mitchell, Douglas A.
A1  - Moll, Gert N.
A1  - Moore, Bradley S.
A1  - Mueller, Rolf
A1  - Nair, Satish K.
A1  - Nes, Ingolf F.
A1  - Norris, Gillian E.
A1  - Olivera, Baldomero M.
A1  - Onaka, Hiroyasu
A1  - Patchett, Mark L.
A1  - Piel, Jörn
A1  - Reaney, Martin J. T.
A1  - Rebuffat, Sylvie
A1  - Ross, R. Paul
A1  - Sahl, Hans-Georg
A1  - Schmidt, Eric W.
A1  - Selsted, Michael E.
A1  - Severinov, Konstantin
A1  - Shen, Ben
A1  - Sivonen, Kaarina
A1  - Smith, Leif
A1  - Stein, Torsten
A1  - Suessmuth, Roderich D.
A1  - Tagg, John R.
A1  - Tang, Gong-Li
A1  - Truman, Andrew W.
A1  - Vederas, John C.
A1  - Walsh, Christopher T.
A1  - Walton, Jonathan D.
A1  - Wenzel, Silke C.
A1  - Willey, Joanne M.
A1  - van der Donk, Wilfred A.
T1  - Ribosomally synthesized and post-translationally modified peptide natural products overview and recommendations for a universal nomenclature
JF  - Natural product reports : a journal of current developments in bio-organic chemistry
N2  - This review presents recommended nomenclature for the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), a rapidly growing class of natural products. The current knowledge regarding the biosynthesis of the >20 distinct compound classes is also reviewed, and commonalities are discussed.
Y1  - 2013
U6  - https://doi.org/10.1039/c2np20085f
SN  - 0265-0568
VL  - 30
IS  - 1
SP  - 108
EP  - 160
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - GEN
A1  - Zeeden, Christian
A1  - Obreht, Igor
A1  - Veres, Daniel
A1  - Kaboth-Bahr, Stefanie
A1  - Hošek, Jan
A1  - Marković, Slobodan B.
A1  - Bösken, Janina
A1  - Lehmkuhl, Frank
A1  - Rolf, Christian
A1  - Hambach, Ulrich
T1  - Smoothed millennial-scale palaeoclimatic reference data as unconventional comparison targets: Application to European loess records
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Millennial-scale palaeoclimate variability has been documented in various terrestrial and marine palaeoclimate proxy records throughout the Northern Hemisphere for the last glacial cycle. Its clear expression and rapid shifts between different states of climate (Greenland Interstadials and Stadials) represents a correlation tool beyond the resolution of e.g. luminescence dating, especially relevant for terrestrial deposits. Usually, comparison of terrestrial proxy datasets and the Greenland ice cores indicates a complex expression of millennial-scale climate variability as recorded in terrestrial geoarchives including loess. Loess is the most widespread terrestrial geoarchive of the Quaternary and especially widespread over Eurasia. However, loess often records a smoothed representation of millennial-scale variability without all fidelity when compared to the Greenland data, this being a relevant limiting feature in integrating loess with other palaeoclimate records. To better understand the loess proxy-response to millennial-scale climate variability, we simulate a proxy signal smoothing by natural processes through application of low-pass filters of delta O-18 data from Greenland, a high-resolution palaeoclimate reference record, alongside speleothem isotope records from the Black Sea-Mediterranean region. We show that low-pass filters represent rather simple models for better constraining the expression of millennial-scale climate variability in low sedimentation environments, and in sediments where proxy-response signals are most likely affected by natural smoothing (by e.g. bioturbation). Interestingly, smoothed datasets from Greenland and the Black Sea-Mediterranean region are most similar in the last similar to 15 ka and between similar to 50-30 ka. Between similar to 30-15 ka, roughly corresponding to the Last Glacial Maximum and the deglaciation, the records show dissimilarities, challenging the construction of robust correlative time-scales in this age range. From our analysis it becomes apparent that patterns of palaeoclimate signals in loess-palaeosol sequences often might be better explained by smoothed Greenland reference data than the original high-resolution Greenland dataset, or other reference data. This opens the possibility to better assess the temporal resolution and palaeoclimate potential of loess-palaeosol sequences in recording supra-regional climate patterns, as well as to securely integrate loess with other chronologically better-resolved palaeoclimate records.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1187 
KW  - last glacial period
KW  - Western Interior Basin
KW  - high-resolution record
KW  - Greenland ice cores
KW  - paleosol sequence
KW  - time-scale
KW  - Chinese loess
KW  - astronomical calibration
KW  - chronology (AICC2012)
KW  - Antarctic ice
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-524271
SN  - 1866-8372
IS  - 1
ER  - 
TY  - CHAP
A1  - Heinisch, Isabelle
A1  - Romeike, Ralf
A1  - Knobelsdorf, Maria
A1  - Kreitz, Christoph
A1  - Nylén, Aletta
A1  - Dörge, Christina
A1  - Göttel, Timo
A1  - Holz, Jan
A1  - Bergner, Nadine
A1  - Schroeder, Ulrik
A1  - Metzger, Christiane
A1  - Haag, Johann
A1  - Abke, Jörg
A1  - Schwirtlich, Vincent
A1  - Sedelmaier, Yvonne
A1  - Müller, Dorothee
A1  - Frommer, Andreas
A1  - Humbert, Ludger
A1  - Berges, Marc
A1  - Mühling, Andreas
A1  - Hubwieser, Peter
A1  - Steuer, Horst
A1  - Engbring, Dieter
A1  - Selke, Harald
A1  - Drews, Paul
A1  - Schirmer, Ingrid
A1  - Morisse, Marcel
A1  - Sagawe, Arno
A1  - Rolf, Arno
A1  - Friedemann, Stefan
A1  - Gröger, Stefan
A1  - Schumann, Matthias
A1  - Klinger, Melanie
A1  - Polutina, Olena
A1  - Bibel, Ariane
A1  - Götz, Christian
A1  - Brinda, Torsten
A1  - Apel, Rebecca
A1  - Berg, Tobias
A1  - Bergner, Nadine
A1  - Chatti, Mohamed Amine
A1  - Leicht-Scholten, Carmen
A1  - Schroeder, Ulrik
A1  - Al-Saffar, Loay Talib
A1  - Petre, Marian
A1  - Schirmer, Ingrid
A1  - Rick, Detlef
ED  - Forbrig, Peter
ED  - Rick, Detlef
ED  - Schmolitzky, Axel
T1  - HDI 2012 – Informatik für eine nachhaltige Zukunft : 5. Fachtagung Hochschuldidaktik der Informatik ; 06.–07. November 2012, Universität Hamburg
N2  - Die Tagungsreihe zur Hochschuldidaktik der Informatik HDI wird vom Fachbereich Informatik und Ausbildung / Didaktik der Informatik (IAD) in der Gesellschaft für Informatik e. V. (GI) organisiert. Sie dient den Lehrenden der Informatik in Studiengängen an Hochschulen als Forum der Information und des Austauschs über neue didaktische Ansätze und bildungspolitische Themen im Bereich der Hochschulausbildung aus der fachlichen Perspektive der Informatik. Diese fünfte HDI 2012 wurde an der Universität Hamburg organisiert. Für sie wurde das spezielle Motto „Informatik für eine nachhaltige Zukunft“ gewählt, um insbesondere Fragen der Bildungsrelevanz informatischer Inhalte, der Kompetenzen für Studierende informatisch geprägter Studiengänge und der Rolle der Informatik in der Hochschulentwicklung zu diskutieren.
T3  - Commentarii informaticae didacticae (CID) - 5 
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-62891
SN  - 978-3-86956-220-9
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Wilczek, Michael
A1  - Wolf, Christian
A1  - Bertling, Jürgen
A1  - Kümmel, Rolf
T1  - Gewinnung von feinteiligem Brennstoff aus Abfällen
JF  - Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-3330
SN  - 1434-2375
SN  - 1611-9339
VL  - 6
SP  - 178
EP  - 190
ER  - 
TY  - JOUR
A1  - Schall, Peter
A1  - Gossner, Martin M.
A1  - Heinrichs, Steffi
A1  - Fischer, Markus
A1  - Boch, Steffen
A1  - Prati, Daniel
A1  - Jung, Kirsten
A1  - Baumgartner, Vanessa
A1  - Blaser, Stefan
A1  - Böhm, Stefan
A1  - Buscot, Francois
A1  - Daniel, Rolf
A1  - Goldmann, Kezia
A1  - Kaiser, Kristin
A1  - Kahl, Tiemo
A1  - Lange, Markus
A1  - Müller, Jörg Hans
A1  - Overmann, Jörg
A1  - Renner, Swen C.
A1  - Schulze, Ernst-Detlef
A1  - Sikorski, Johannes
A1  - Tschapka, Marco
A1  - Türke, Manfred
A1  - Weisser, Wolfgang W.
A1  - Wemheuer, Bernd
A1  - Wubet, Tesfaye
A1  - Ammer, Christian
T1  - The impact of even-aged and uneven-aged forest management on regional biodiversity of multiple taxa in European beech forests
JF  - Journal of applied ecology : an official journal of the British Ecological Society
N2  - 1. For managed temperate forests, conservationists and policymakers favour fine-grained uneven-aged (UEA) management over more traditional coarse-grained even-aged (EA) management, based on the assumption that within-stand habitat heterogeneity enhances biodiversity. There is, however, little empirical evidence to support this assumption. We investigated for the first time how differently grained forest management systems affect the biodiversity of multiple above- and below-ground taxa across spatial scales. 2. We sampled 15 taxa of animals, plants, fungi and bacteria within the largest contiguous beech forest landscape of Germany and classified them into functional groups. Selected forest stands have been managed for more than a century at different spatial grains. The EA (coarse-grained management) and UEA (fine-grained) forests are comparable in spatial arrangement, climate and soil conditions. These were compared to forests of a nearby national park that have been unmanaged for at least 20years. We used diversity accumulation curves to compare -diversity for Hill numbers D-0 (species richness), D-1 (Shannon diversity) and D-2 (Simpson diversity) between the management systems. Beta diversity was quantified as multiple-site dissimilarity. 3. Gamma diversity was higher in EA than in UEA forests for at least one of the three Hill numbers for six taxa (up to 77%), while eight showed no difference. Only bacteria showed the opposite pattern. Higher -diversity in EA forests was also found for forest specialists and saproxylic beetles. 4. Between-stand -diversity was higher in EA than in UEA forests for one-third (all species) and half (forest specialists) of all taxa, driven by environmental heterogeneity between age-classes, while -diversity showed no directional response across taxa or for forest specialists. 5. Synthesis and applications. Comparing EA and uneven-aged forest management in Central European beech forests, our results show that a mosaic of different age-classes is more important for regional biodiversity than high within-stand heterogeneity. We suggest reconsidering the current trend of replacing even-aged management in temperate forests. Instead, the variability of stages and stand structures should be increased to promote landscape-scale biodiversity.
KW  - beta diversity
KW  - forest specialists
KW  - gamma diversity
KW  - heterogeneity
KW  - Hill numbers
KW  - saproxylic beetles
KW  - spatial grain
KW  - species accumulation curve
KW  - species richness
KW  - species turnover
Y1  - 2017
U6  - https://doi.org/10.1111/1365-2664.12950
SN  - 0021-8901
SN  - 1365-2664
VL  - 55
IS  - 1
SP  - 267
EP  - 278
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - BOOK
A1  - Andrae, Marianne
A1  - Ebert, Johannes
A1  - Garbe-von Kuczkowski, Angela
A1  - Garbe, Roland
A1  - Grabow, Christian
A1  - Klees-Wambach, Marie-Luise
A1  - Kofler, Rolf
A1  - Mittmann, Michael
A1  - Nickel, Michael
A1  - Nöthen, Thomas
A1  - Schrader-Kroschewski, Karen
A1  - Schramm, Barbara
A1  - Ulrich, Christoph
ED  - Garbe, Roland
T1  - Verfahren in Familiensachen : FamFG ; ZPO ; BGB
T3  - Nomos ProzessHandbuch
Y1  - 2009
SN  - 978-3-8329-3973-1
PB  - Nomos; Beck-Online
CY  - Baden-Baden; München
ER  - 
TY  - JOUR
A1  - Sprenger, Heike
A1  - Rudack, Katharina
A1  - Schudoma, Christian
A1  - Neumann, Arne
A1  - Seddig, Sylvia
A1  - Peters, Rolf
A1  - Zuther, Ellen
A1  - Kopka, Joachim
A1  - Hincha, Dirk K.
A1  - Walther, Dirk
A1  - Koehl, Karin
T1  - Assessment of drought tolerance and its potential yield penalty in potato
JF  - Functional plant biology : an international journal of plant function
N2  - Climate models predict an increased likelihood of seasonal droughts for many areas of the world. Breeding for drought tolerance could be accelerated by marker-assisted selection. As a basis for marker identification, we studied the genetic variance, predictability of field performance and potential costs of tolerance in potato (Solanum tuberosum L.). Potato produces high calories per unit of water invested, but is drought-sensitive. In 14 independent pot or field trials, 34 potato cultivars were grown under optimal and reduced water supply to determine starch yield. In an artificial dataset, we tested several stress indices for their power to distinguish tolerant and sensitive genotypes independent of their yield potential. We identified the deviation of relative starch yield from the experimental median (DRYM) as the most efficient index. DRYM corresponded qualitatively to the partial least square model-based metric of drought stress tolerance in a stress effect model. The DRYM identified significant tolerance variation in the European potato cultivar population to allow tolerance breeding and marker identification. Tolerance results from pot trials correlated with those from field trials but predicted field performance worse than field growth parameters. Drought tolerance correlated negatively with yield under optimal conditions in the field. The distribution of yield data versus DRYM indicated that tolerance can be combined with average yield potentials, thus circumventing potential yield penalties in tolerance breeding.
KW  - performance prediction
KW  - Solanum tuberosum
KW  - tolerance index
KW  - target environment
Y1  - 2015
U6  - https://doi.org/10.1071/FP15013
SN  - 1445-4408
SN  - 1445-4416
VL  - 42
IS  - 7
SP  - 655
EP  - 667
PB  - CSIRO
CY  - Clayton
ER  - 
TY  - JOUR
A1  - Schröder, Rolf
A1  - Fürst, Dieter Oswald
A1  - Klasen, Christian
A1  - Reiman, Jens
A1  - Herrmann, Harald
A1  - VanDerVen, Peter F. M.
T1  - The association of plectin with Z-discs is a prerequisite for the formation of the intermyofibrillar desmin cytoskeleton
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Schröder, Rolf
A1  - Warlo, Irene
A1  - Herrmann, Harald
A1  - VanDerVen, Peter F. M
A1  - Klasen, Christian
A1  - Blümke, Ingmar
A1  - Mundegar, Rustam R.
A1  - Fürst, Dieter Oswald
A1  - Göbel, Hans H.
A1  - Magin, Thomas
T1  - Immunogold EM reveals a close association of plectin and the desmin cytoskeleton in human skeletal muscle
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Secker, Christian
A1  - Brosnan, Sarah M.
A1  - Limberg, Felix Rolf Paul
A1  - Braun, Ulrike
A1  - Trunk, Matthias
A1  - Strauch, Peter
A1  - Schlaad, Helmut
T1  - Thermally Induced Crosslinking of Poly(N-Propargyl Glycine)
JF  - Macromolecular chemistry and physics
N2  - As polypeptoids become increasingly popular, they present a more soluble and processable alternative to natural and synthetic polypeptides; the breadth of their potential functionality slowly comes into focus. This report analyzes the ability of an alkyne-functionalized polypeptoid, poly(N-propargyl glycine), to crosslink upon heating. The crosslinking process is analyzed by thermal analysis (differential scanning calorimetry and thermogravimetric analysis), Fourier-transform infrared, electron paramagnetic resonance, and solid-state NMR spectroscopy. While a precise mechanism cannot be confidently assigned, it is clear that the reaction proceeds by a radical mechanism that exclusively involves the alkyne functionality, which, upon crosslinking, yields alkene and aromatic products.
KW  - Fourier-transform infrared
KW  - metal-free crosslinking
KW  - polypeptoid
KW  - propargyl
KW  - solid-state NMR
Y1  - 2015
U6  - https://doi.org/10.1002/macp.201500223
SN  - 1022-1352
SN  - 1521-3935
VL  - 216
IS  - 21
SP  - 2080
EP  - 2085
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Kubin, Markus
A1  - Kern, Jan
A1  - Gul, Sheraz
A1  - Kroll, Thomas
A1  - Chatterjee, Ruchira
A1  - Loechel, Heike
A1  - Fuller, Franklin D.
A1  - Sierra, Raymond G.
A1  - Quevedo, Wilson
A1  - Weniger, Christian
A1  - Rehanek, Jens
A1  - Firsov, Anatoly
A1  - Laksmono, Hartawan
A1  - Weninger, Clemens
A1  - Alonso-Mori, Roberto
A1  - Nordlund, Dennis L.
A1  - Lassalle-Kaiser, Benedikt
A1  - Glownia, James M.
A1  - Krzywinski, Jacek
A1  - Moeller, Stefan
A1  - Turner, Joshua J.
A1  - Minitti, Michael P.
A1  - Dakovski, Georgi L.
A1  - Koroidov, Sergey
A1  - Kawde, Anurag
A1  - Kanady, Jacob S.
A1  - Tsui, Emily Y.
A1  - Suseno, Sandy
A1  - Han, Zhiji
A1  - Hill, Ethan
A1  - Taguchi, Taketo
A1  - Borovik, Andrew S.
A1  - Agapie, Theodor
A1  - Messinger, Johannes
A1  - Erko, Alexei
A1  - Föhlisch, Alexander
A1  - Bergmann, Uwe
A1  - Mitzner, Rolf
A1  - Yachandra, Vittal K.
A1  - Yano, Junko
A1  - Wernet, Philippe
T1  - Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers
JF  - Structural dynamics
N2  - X-ray absorption spectroscopy at the L-edge of 3d transition metals provides unique information on the local metal charge and spin states by directly probing 3d-derived molecular orbitals through 2p-3d transitions. However, this soft x-ray technique has been rarely used at synchrotron facilities for mechanistic studies of metalloenzymes due to the difficulties of x-ray-induced sample damage and strong background signals from light elements that can dominate the low metal signal. Here, we combine femtosecond soft x-ray pulses from a free-electron laser with a novel x-ray fluorescence-yield spectrometer to overcome these difficulties. We present L-edge absorption spectra of inorganic high-valent Mn complexes (Mn similar to 6-15 mmol/l) with no visible effects of radiation damage. We also present the first L-edge absorption spectra of the oxygen evolving complex (Mn4CaO5) in Photosystem II (Mn < 1 mmol/l) at room temperature, measured under similar conditions. Our approach opens new ways to study metalloenzymes under functional conditions. (C) 2017 Author(s).
Y1  - 2017
U6  - https://doi.org/10.1063/1.4986627
SN  - 2329-7778
VL  - 4
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Kroll, Thomas
A1  - Kern, Jan
A1  - Kubin, Markus
A1  - Ratner, Daniel
A1  - Gul, Sheraz
A1  - Fuller, Franklin D.
A1  - Löchel, Heike
A1  - Krzywinski, Jacek
A1  - Lutman, Alberto
A1  - Ding, Yuantao
A1  - Dakovski, Georgi L.
A1  - Moeller, Stefan
A1  - Turner, Joshua J.
A1  - Alonso-Mori, Roberto
A1  - Nordlund, Dennis L.
A1  - Rehanek, Jens
A1  - Weniger, Christian
A1  - Firsov, Alexander
A1  - Brzhezinskaya, Maria
A1  - Chatterjee, Ruchira
A1  - Lassalle-Kaiser, Benedikt
A1  - Sierra, Raymond G.
A1  - Laksmono, Hartawan
A1  - Hill, Ethan
A1  - Borovik, Andrew S.
A1  - Erko, Alexei
A1  - Föhlisch, Alexander
A1  - Mitzner, Rolf
A1  - Yachandra, Vittal K.
A1  - Yano, Junko
A1  - Wernet, Philippe
A1  - Bergmann, Uwe
T1  - X-ray absorption spectroscopy using a self-seeded soft X-ray free-electron laser
JF  - Optics express : the international electronic journal of optics
N2  - X-ray free electron lasers (XFELs) enable unprecedented new ways to study the electronic structure and dynamics of transition metal systems. L-edge absorption spectroscopy is a powerful technique for such studies and the feasibility of this method at XFELs for solutions and solids has been demonstrated. However, the required x-ray bandwidth is an order of magnitude narrower than that of self-amplified spontaneous emission (SASE), and additional monochromatization is needed. Here we compare L-edge x-ray absorption spectroscopy (XAS) of a prototypical transition metal system based on monochromatizing the SASE radiation of the linac coherent light source (LCLS) with a new technique based on self-seeding of LCLS. We demonstrate how L-edge XAS can be performed using the self-seeding scheme without the need of an additional beam line monochromator. We show how the spectral shape and pulse energy depend on the undulator setup and how this affects the x-ray spectroscopy measurements. (C) 2016 Optical Society of America
Y1  - 2016
U6  - https://doi.org/10.1364/OE.24.022469
SN  - 1094-4087
VL  - 24
SP  - 22469
EP  - 22480
PB  - Optical Society of America
CY  - Washington
ER  - 
TY  - JOUR
A1  - Mitzner, Rolf
A1  - Rehanek, Jens
A1  - Kern, Jan
A1  - Gul, Sheraz
A1  - Hattne, Johan
A1  - Taguchi, Taketo
A1  - Alonso-Mori, Roberto
A1  - Tran, Rosalie
A1  - Weniger, Christian
A1  - Schröder, Henning
A1  - Quevedo, Wilson
A1  - Laksmono, Hartawan
A1  - Sierra, Raymond G.
A1  - Han, Guangye
A1  - Lassalle-Kaiser, Benedikt
A1  - Koroidov, Sergey
A1  - Kubicek, Katharina
A1  - Schreck, Simon
A1  - Kunnus, Kristjan
A1  - Brzhezinskaya, Maria
A1  - Firsov, Alexander
A1  - Minitti, Michael P.
A1  - Turner, Joshua J.
A1  - Möller, Stefan
A1  - Sauter, Nicholas K.
A1  - Bogan, Michael J.
A1  - Nordlund, Dennis
A1  - Schlotter, William F.
A1  - Messinger, Johannes
A1  - Borovik, Andrew S.
A1  - Techert, Simone
A1  - de Groot, Frank M. F.
A1  - Föhlisch, Alexander
A1  - Erko, Alexei
A1  - Bergmann, Uwe
A1  - Yachandra, Vittal K.
A1  - Wernet, Philippe
A1  - Yano, Junko
T1  - L-edge x-ray absorption spectroscopy of dilute systems relevant to metalloproteins using an X-ray free-electron laser
JF  - The journal of physical chemistry letters
N2  - L-edge spectroscopy of 3d transition metals provides important electronic structure information and has been used in many fields. However, the use of this method for studying dilute aqueous systems, such as metalloenzymes, has not been prevalent because of severe radiation damage and the lack of suitable detection systems. Here we present spectra from a dilute Mn aqueous solution using a high-transmission zone-plate spectrometer at the Linac Coherent Light Source (LCLS). The spectrometer has been optimized for discriminating the Mn L-edge signal from the overwhelming 0 K-edge background that arises from water and protein itself, and the ultrashort LCLS X-ray pulses can outrun X-ray induced damage. We show that the deviations of the partial-fluorescence yield-detected spectra from the true absorption can be well modeled using the state-dependence of the fluorescence yield, and discuss implications for the application of our concept to biological samples.
Y1  - 2013
U6  - https://doi.org/10.1021/jz401837f
SN  - 1948-7185
VL  - 4
IS  - 21
SP  - 3641
EP  - 3647
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schick, Daniel
A1  - Le Guyader, Loic
A1  - Pontius, Niko
A1  - Radu, Ilie
A1  - Kachel, Torsten
A1  - Mitzner, Rolf
A1  - Zeschke, Thomas
A1  - Schuessler-Langeheine, Christian
A1  - Föhlisch, Alexander
A1  - Holldack, Karsten
T1  - Analysis of the halo background in femtosecond slicing experiments
JF  - Journal of synchrotron radiation
N2  - The slicing facility FemtoSpeX at BESSY II offers unique opportunities to study photo-induced dynamics on femtosecond time scales by means of X-ray magnetic circular dichroism, resonant and non-resonant X-ray diffraction, and X-ray absorption spectroscopy experiments in the soft X-ray regime. Besides femtosecond X-ray pulses, slicing sources inherently also produce a so-called `halo' background with a different time structure, polarization and pointing. Here a detailed experimental characterization of the halo radiation is presented, and a method is demonstrated for its correct and unambiguous removal from femtosecond time-resolved data using a special laser triggering scheme as well as analytical models. Examples are given for time-resolved measurements with corresponding halo correction, and errors of the relevant physical quantities caused by either neglecting or by applying a simplified model to describe this background are estimated.
KW  - femtosecond slicing
KW  - halo
KW  - pump-probe
KW  - XMCD
KW  - X-ray scattering
Y1  - 2016
U6  - https://doi.org/10.1107/S160057751600401X
SN  - 1600-5775
VL  - 23
SP  - 700
EP  - 711
PB  - International Union of Crystallography
CY  - Chester
ER  - 
TY  - GEN
A1  - Eschenlohr, Andrea
A1  - Battiato, Mario
A1  - Maldonado, P.
A1  - Pontius, N.
A1  - Kachel, T.
A1  - Holldack, K.
A1  - Mitzner, Rolf
A1  - Föhlisch, Alexander
A1  - Oppeneer, P. M.
A1  - Stamm, Christian
T1  - Optical excitation of thin magnetic layers in multilayer structures Reply
T2  - Nature materials
Y1  - 2014
U6  - https://doi.org/10.1038/nmat3851
SN  - 1476-1122
SN  - 1476-4660
VL  - 13
IS  - 2
SP  - 102
EP  - 103
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Thielemann-Kühn, Nele
A1  - Schick, Daniel
A1  - Pontius, Niko
A1  - Trabant, Christoph
A1  - Mitzner, Rolf
A1  - Holldack, Karsten
A1  - Zabel, Hartmut
A1  - Föhlisch, Alexander
A1  - Schuessler-Langeheine, Christian
T1  - Ultrafast and Energy-Efficient Quenching of Spin Order: Antiferromagnetism Beats Ferromagnetism
JF  - Physical review letters
N2  - By comparing femtosecond laser pulse induced ferro- and antiferromagnetic dynamics in one and the same material-metallic dysprosium-we show both to behave fundamentally different. Antiferromagnetic order is considerably faster and much more efficiently reduced by optical excitation than its ferromagnetic counterpart. We assign the fast and extremely efficient process in the antiferromagnet to an interatomic transfer of angular momentum within the spin system. Our findings imply that this angular momentum transfer channel is effective in other magnetic metals with nonparallel spin alignment. They also point out a possible route towards energy-efficient spin manipulation for magnetic devices.
Y1  - 2017
U6  - https://doi.org/10.1103/PhysRevLett.119.197202
SN  - 0031-9007
SN  - 1079-7114
VL  - 119
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Sirocko, Frank
A1  - Dietrich, Stephan
A1  - Veres, Daniel
A1  - Grootes, Pieter M.
A1  - Schaber-Mohr, Katja
A1  - Seelos, Klemens
A1  - Nadeau, Marie-Josee
A1  - Kromer, Bernd
A1  - Rothacker, Leo
A1  - Roehner, Marieke
A1  - Krbetschek, Matthias
A1  - Appleby, Peter G.
A1  - Hambach, Ulrich
A1  - Rolf, Christian
A1  - Sudo, Masafumi
A1  - Grim, Stephanie
T1  - Multi-proxy dating of Holocene maar lakes and Pleistocene dry maar sediments in the Eifel, Germany
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - During the last twelve years the ELSA Project (Eifel Laminated Sediment Archive) at Mainz University has drilled a total of about 52 cores from 27 maar lakes and filled-in maar basins in the Eifel/Germany. Dating has been completed for the Holocene cores using 6 different methods (Pb-210 and Cs-137 activities, palynostratigraphy, event markers, varve counting, C-14) In general, the different methods consistently complement one another within error margins. Event correlation was used for relating typical lithological changes with historically known events such as the two major Holocene flood events at 1342 AD and ca 800 BC. Dating of MIS2-MIS3 core sections is based on greyscale tuning, radiocarbon and OSL dating, magnetostratigraphy and tephrochronology. The lithological changes in the sediment cores demonstrate a sequence of events similar to the North Atlantic rapid climate variability of the Last Glacial Cycle. The warmest of the MIS3 interstadials was GI14, when a forest with abundant spruce covered the Eifel area from 55 to 48 ka BP, i.e. during a time when also other climate archives in Europe suggested very warm conditions. The forest of this "Early Stage 3 warm phase" developed subsequently into a steppe with scattered birch and pine, and finally into a glacial desert at around 25 ka BP. Evidence for Mono Lake and Laschamp geomagnetic excursions is found in two long cores. Several large eruptions during Middle and Late Pleistocene (Ulmener Maar - 11,000 varve years BP, Laacher See - 12,900 varve years BP, Mosenberg volcanoes/Meerfelder Maar 41-45 cal ka BP, Dumpel Maar 116 ka BP, Glees Maar - 151 ka BP) produced distinct ash-layers crucial for inter-core and inter-site correlations. The oldest investigated maar of the Eifel is Ar-40/Ar-39 dated to the time older than 520 ka BP.
KW  - Eifel maar
KW  - Laminated lake sediments
KW  - Tuning
KW  - Historical events
KW  - C-14-derived chronology
KW  - Varve counting
KW  - Luminescence dating
KW  - Palynostratigraphy
KW  - (CS)-C-137 and Pb-210 dating
KW  - Palaeomagnetism
KW  - Tephrostratigraphy
KW  - Argon-Argon dating
KW  - GIS
Y1  - 2013
U6  - https://doi.org/10.1016/j.quascirev.2012.09.011
SN  - 0277-3791
VL  - 62
SP  - 56
EP  - 76
PB  - Elsevier
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, Florian
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  - 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, Florian
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  -