@article{VillatoroWeberZuehlkeetal.2019, author = {Villatoro, Jos{\´e} Andr{\´e}s and Weber, M. and Z{\"u}hlke, Martin and Lehmann, A. and Zenichowski, Karl and Riebe, Daniel and Beitz, Toralf and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Kreuzer, O.}, title = {Structural characterization of synthetic peptides using electrospray ion mobility spectrometry and molecular dynamics simulations}, series = {International Journal of Mass Spectrometry}, volume = {436}, journal = {International Journal of Mass Spectrometry}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1387-3806}, doi = {10.1016/j.ijms.2018.10.036}, pages = {108 -- 117}, year = {2019}, abstract = {Electrospray ionization-ion mobility spectrometry was employed for the determination of collision cross sections (CCS) of 25 synthetically produced peptides in the mass range between 540-3310 Da. The experimental measurement of the CCS is complemented by their calculation applying two different methods. One prediction method is the intrinsic size parameter (ISP) method developed by the Clemmer group. The second new method is based on the evaluation of molecular dynamics (MD) simulation trajectories as a whole, resulting in a single, averaged collision cross-section value for a given peptide in the gas phase. A high temperature MD simulation is run in order to scan through the whole conformational space. The lower temperature conformational distribution is obtained through thermodynamic reweighting. In the first part, various correlations, e.g. CCS vs. mass and inverse mobility vs. m/z correlations, are presented. Differences in CCS between peptides are also discussed in terms of their respective mass and m/z differences, as well as their respective structures. In the second part, measured and calculated CCS are compared. The agreement between the prediction results and the experimental values is in the same range for both calculation methods. While the calculation effort of the ISP method is much lower, the MD method comprises several tools providing deeper insights into the conformations of peptides. Advantages and limitations of both methods are discussed. Based on the separation of two pairs of linear and cyclic peptides of virtually the same mass, the influence of the structure on the cross sections is discussed. The shift in cross section differences and peak shape after transition from the linear to the cyclic peptide can be well understood by applying different MD tools, e.g. the root-mean-square deviation (RMSD) and the root mean square fluctuation (RMSF). (C) 2018 Elsevier B.V. All rights reserved.}, language = {en} } @book{PohlenzSchubarthSpecketal.2011, author = {Pohlenz, Philipp and Schubarth, Wilfried and Speck, Karsten and Seidel, Andreas and Winter, Martin and Heine, Christoph and Kleinfeld, Merle and Sarrar, Lea and Gemsa, Charlotte and Wendland, Mirko and Schlumm, Katharina and Lehmann, Uta and Kummerow, Udo and Bastian, Laura and Kamm, Caroline and Niproschke, Saskia and Sochadse, Lascha and Kotzur, Katharina and Hebert, Sebastian and Voigt, Frank and Kopp, Andrea}, title = {Nach Bologna: Praktika im Studium - Pflicht oder K{\"u}r?}, editor = {Schubarth, Wilfried and Speck, Karsten and Seidel, Andreas}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-123-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51033}, publisher = {Universit{\"a}t Potsdam}, pages = {iii, 339}, year = {2011}, abstract = {Mit dem vorliegenden Band „Nach Bologna: Praktika im Studium - Pflicht oder K{\"u}r? Empirische Analysen und Empfehlungen f{\"u}r die Hochschulpraxis" von Wilfried Schubarth, Karsten Speck und Andreas Seidel wird die Reihe „Potsdamer Beitr{\"a}ge zur Lehrevaluation" unter neuem Titel und ver{\"a}nderter inhaltlicher Schwerpunktsetzung fortgef{\"u}hrt. Die Umbenennung in „Potsdamer Beitr{\"a}ge zur Hochschulforschung" versteht sich als ein Schritt hin zu einer thematischen {\"O}ffnung der Reihe f{\"u}r 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 vielf{\"a}ltige strukturelle und inhaltliche Ziele verfolgt. Das Ziel dieses Bandes besteht deshalb darin, empirische Forschungen zu Praxisbez{\"u}gen und Praxisphasen im Studium vorzustellen, diese in den Kontext aktueller Debatten um Studienqualit{\"a}t und Studienreform zu stellen sowie Folgerungen f{\"u}r die Gestaltung von Praxisphasen abzuleiten. Inhaltliche Schwerpunkte bilden das BMBF-Forschungsprojekt ProPrax und die Praxisphasen im Lehramtsstudium. Die Beitr{\"a}ge dieses Bandes gehen aus einem gleichnamigen Workshop hervor, der am 1. Oktober 2010 in Potsdam stattfand.}, language = {de} } @phdthesis{Lehmann2011, author = {Lehmann, Martin}, title = {Back to the roots : regulation of arabidopsis root metabolism during oxidative stress}, address = {Potsdam}, pages = {154 S.}, year = {2011}, language = {en} } @article{JanssenArhonditsisBeusenetal.2015, author = {Janssen, Annette B. G. and Arhonditsis, George B. and Beusen, Arthur and Bolding, Karsten and Bruce, Louise and Bruggeman, Jorn and Couture, Raoul-Marie and Downing, Andrea S. and Elliott, J. Alex and Frassl, Marieke A. and Gal, Gideon and Gerla, Daan J. and Hipsey, Matthew R. and Hu, Fenjuan and Ives, Stephen C. and Janse, Jan H. and Jeppesen, Erik and Joehnk, Klaus D. and Kneis, David and Kong, Xiangzhen and Kuiper, Jan J. and Lehmann, Moritz K. and Lemmen, Carsten and Oezkundakci, Deniz and Petzoldt, Thomas and Rinke, Karsten and Robson, Barbara J. and Sachse, Rene and Schep, Sebastiaan A. and Schmid, Martin and Scholten, Huub and Teurlincx, Sven and Trolle, Dennis and Troost, Tineke A. and Van Dam, Anne A. and Van Gerven, Luuk P. A. and Weijerman, Mariska and Wells, Scott A. and Mooij, Wolf M.}, title = {Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective}, series = {Aquatic ecology : the international forum covering research in freshwater and marine environments}, volume = {49}, journal = {Aquatic ecology : the international forum covering research in freshwater and marine environments}, number = {4}, publisher = {Springer}, address = {Dordrecht}, issn = {1386-2588}, doi = {10.1007/s10452-015-9544-1}, pages = {513 -- 548}, year = {2015}, abstract = {Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of existing models. Finally, we discuss how model diversity came about in the past and could evolve in the future. Throughout our study, we use analogies from biodiversity research to analyse and interpret model diversity. We recommend to make models publicly available through open-source policies, to standardize documentation and technical implementation of models, and to compare models through ensemble modelling and interdisciplinary approaches. We end with our perspective on how the field of aquatic ecosystem modelling might develop in the next 5-10 years. To strive for clarity and to improve readability for non-modellers, we include a glossary.}, language = {en} } @article{FranzToebbensLehmannetal.2020, author = {Franz, Alexandra and T{\"o}bbens, Daniel M. and Lehmann, Frederike and K{\"a}rgell, Martin and Schorr, Susan}, title = {The influence of deuteration on the crystal structure of hybrid halide perovskites: a temperature-dependent neutron diffraction study of FAPbBr(3)}, series = {Acta crystallographica; Section B, Structural science, crystal engineering and materials}, volume = {76}, journal = {Acta crystallographica; Section B, Structural science, crystal engineering and materials}, number = {2}, publisher = {Wiley-Blackwell}, address = {Oxford [u.a.]}, issn = {2052-5206}, doi = {10.1107/S2052520620002620}, pages = {267 -- 274}, year = {2020}, abstract = {This paper discusses the full structural solution of the hybrid perovskite formamidinium lead tribromide (FAPbBr(3)) and its temperature-dependent phase transitions in the range from 3 K to 300 K using neutron powder diffraction and synchrotron X-ray diffraction. Special emphasis is put on the influence of deuteration on formamidinium, its position in the unit cell and disordering in comparison to fully hydrogenated FAPbBr(3). The temperature-dependent measurements show that deuteration critically influences the crystal structures, i.e. results in partially-ordered temperature-dependent structural modifications in which two symmetry-independent molecule positions with additional dislocation of the molecular centre atom and molecular angle inclinations are present.}, language = {en} } @article{HermanussenLiebermanSchoenfeldJanewaetal.2012, author = {Hermanussen, Michael and Lieberman, L. S. and Sch{\"o}nfeld Janewa, U. and Scheffler, Christiane and Ghosh, A. and Bogin, Barry and Godina, E. and Kaczmarek, M. and El-Shabrawi, M. and Salama, E. E. and R{\"u}hli, F. J. and Staub, K. and Woitek, U. and Blaha, Pawel and vanBuurren, S. and Lehmann, A. and Satake, T. and Thodberg, H. H. and Jopp, E. and Kirchengast, S. and Tutkuviene, J. and McIntyre, M. H. and Wittwer-Backofen, U. and Boldsen, J. L. and Martin, D. D. and Meier, J.}, title = {Diversity in auxology: between theory and practice Proceedings of the 18th Aschauer Soiree, 13th November 2010}, issn = {0003-5548}, year = {2012}, language = {en} } @article{HermanussenLiebermanJanewaetal.2012, author = {Hermanussen, Michael and Lieberman, Leslie Su and Janewa, V. Schoenfeld and Scheffler, Christiane and Ghosh, Arunava and Bogin, Barry and Godina, Elena and Kaczmarek, M. and El-Shabrawi, M. and Salama, E. E. and R{\"u}hli, Frank J. and Staub, Kaspar and Woitek, U. and Blaha, Pawel and Aßmann, Christian and van Buuren, Stef and Lehmann, A. and Satake, T. and Thodberg, H. H. and Jopp, E. and Kirchengast, S. and Tutkuviene, J. and McIntyre, M. H. and Wittwer-Backofen, U. and Boldsen, Jesper L. and Martin, D. D. and Meier, J.}, title = {Diversity in auxology between theory and practice}, series = {Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft f{\"u}r Anthropologie}, volume = {69}, journal = {Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft f{\"u}r Anthropologie}, number = {2}, publisher = {Schweizerbart}, address = {Stuttgart}, issn = {0003-5548}, doi = {10.1127/0003-5548/2012/0133}, pages = {159 -- 174}, year = {2012}, abstract = {Auxology has developed from mere describing child and adolescent growth into a vivid and interdisciplinary research area encompassing human biologists, physicians, social scientists, economists and biostatisticians. The meeting illustrated the diversity in auxology, with the various social, medical, biological and biostatistical aspects in studies on child growth and development.}, language = {en} } @article{HenschDahmRitteretal.2019, author = {Hensch, Martin and Dahm, Torsten and Ritter, Joachim and Heimann, Sebastian and Schmidt, Bernd and Stange, Stefan and Lehmann, Klaus}, title = {Deep low-frequency earthquakes reveal ongoing magmatic recharge beneath Laacher See Volcano (Eifel, Germany)}, series = {Geophysical journal international}, volume = {216}, journal = {Geophysical journal international}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0956-540X}, doi = {10.1093/gji/ggy532}, pages = {2025 -- 2036}, year = {2019}, abstract = {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.}, language = {en} } @article{PuchkovMuellerLehmannetal.2023, author = {Puchkov, Dmytro and M{\"u}ller, Paul Markus and Lehmann, Martin and Matth{\"a}us, Claudia}, title = {Analyzing the cellular plasma membrane by fast and efficient correlative STED and platinum replica EM}, series = {Frontiers in cell and developmental biology}, volume = {11}, journal = {Frontiers in cell and developmental biology}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-634X}, doi = {10.3389/fcell.2023.1305680}, pages = {15}, year = {2023}, abstract = {The plasma membrane of mammalian cells links transmembrane receptors, various structural components, and membrane-binding proteins to subcellular processes, allowing inter- and intracellular communication. Therefore, membrane-binding proteins, together with structural components such as actin filaments, modulate the cell membrane in their flexibility, stiffness, and curvature. Investigating membrane components and curvature in cells remains challenging due to the diffraction limit in light microscopy. Preparation of 5-15-nm-thin plasma membrane sheets and subsequent inspection by metal replica transmission electron microscopy (TEM) reveal detailed information about the cellular membrane topology, including the structure and curvature. However, electron microscopy cannot identify proteins associated with specific plasma membrane domains. Here, we describe a novel adaptation of correlative super-resolution light microscopy and platinum replica TEM (CLEM-PREM), allowing the analysis of plasma membrane sheets with respect to their structural details, curvature, and associated protein composition. We suggest a number of shortcuts and troubleshooting solutions to contemporary PREM protocols. Thus, implementation of super-resolution stimulated emission depletion (STED) microscopy offers significant reduction in sample preparation time and reduced technical challenges for imaging and analysis. Additionally, highly technical challenges associated with replica preparation and transfer on a TEM grid can be overcome by scanning electron microscopy (SEM) imaging. The combination of STED microscopy and platinum replica SEM or TEM provides the highest spatial resolution of plasma membrane proteins and their underlying membrane and is, therefore, a suitable method to study cellular events like endocytosis, membrane trafficking, or membrane tension adaptations.}, language = {en} } @article{LehmannKuhnKelleretal.2022, author = {Lehmann, Nico and Kuhn, Yves-Alain and Keller, Martin and Aye, Norman and Herold, Fabian and Draganski, Bogdan and Taube, Wolfgang and Taubert, Marco}, title = {Brain activation during active balancing and its behavioral relevance in younger and older adults}, series = {Frontiers in Aging Neuroscience}, volume = {14}, journal = {Frontiers in Aging Neuroscience}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1663-4365}, doi = {10.3389/fnagi.2022.828474}, pages = {20}, year = {2022}, abstract = {Age-related deterioration of balance control is widely regarded as an important phenomenon influencing quality of life and longevity, such that a more comprehensive understanding of the neural mechanisms underlying this process is warranted. Specifically, previous studies have reported that older adults typically show higher neural activity during balancing as compared to younger counterparts, but the implications of this finding on balance performance remain largely unclear. Using functional near-infrared spectroscopy (fNIRS), differences in the cortical control of balance between healthy younger (n = 27) and older (n = 35) adults were explored. More specifically, the association between cortical functional activity and balance performance across and within age groups was investigated. To this end, we measured hemodynamic responses (i.e., changes in oxygenated and deoxygenated hemoglobin) while participants balanced on an unstable device. As criterion variables for brain-behavior-correlations, we also assessed postural sway while standing on a free-swinging platform and while balancing on wobble boards with different levels of difficulty. We found that older compared to younger participants had higher activity in prefrontal and lower activity in postcentral regions. Subsequent robust regression analyses revealed that lower prefrontal brain activity was related to improved balance performance across age groups, indicating that higher activity of the prefrontal cortex during balancing reflects neural inefficiency. We also present evidence supporting that age serves as a moderator in the relationship between brain activity and balance, i.e., cortical hemodynamics generally appears to be a more important predictor of balance performance in the older than in the younger. Strikingly, we found that age differences in balance performance are mediated by balancing-induced activation of the superior frontal gyrus, thus suggesting that differential activation of this region reflects a mechanism involved in the aging process of the neural control of balance. Our study suggests that differences in functional brain activity between age groups are not a mere by-product of aging, but instead of direct behavioral relevance for balance performance. Potential implications of these findings in terms of early detection of fall-prone individuals and intervention strategies targeting balance and healthy aging are discussed.}, language = {en} }