@article{CappelSvanstromLanzilottoetal.2017, author = {Cappel, Ute B. and Svanstrom, Sebastian and Lanzilotto, Valeria and Johansson, Fredrik O. L. and Aitola, Kerttu and Philippe, Bertrand and Giangrisostomi, Erika and Ovsyannikov, Ruslan and Leitner, Torsten and F{\"o}hlisch, Alexander and Svensson, Svante and Martensson, Nils and Boschloo, Gerrit and Lindblad, Andreas and Rensmo, Hakan}, title = {Partially Reversible Photoinduced Chemical Changes in a Mixed-Ion Perovskite Material for Solar Cells}, series = {ACS applied materials \& interfaces}, volume = {9}, journal = {ACS applied materials \& interfaces}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/acsami.7b10643}, pages = {34970 -- 34978}, year = {2017}, abstract = {Metal halide perovskites have emerged as materials of high interest for solar energy-to-electricity conversion, and in particular, the use of mixed-ion structures has led to high power conversion efficiencies and improved stability. For this reason, it is important to develop means to obtain atomic level understanding of the photoinduced behavior of these materials including processes such as photoinduced phase separation and ion migration. In this paper, we implement a new methodology combining visible laser illumination of a mixed-ion perovskite ((FAP-bI(3))(0.85)(MAPbBr(3))(0.15)) with the element specificity and chemical sensitivity of core-level photoelectron spectroscopy. By carrying out measurements at a synchrotron beamline optimized for low X-ray fluxes, we are able to avoid sample changes due to X-ray illumination and are therefore able to monitor what sample changes are induced by visible illumination only. We find that laser illumination causes partially reversible chemistry in the surface region, including enrichment of bromide at the surface, which could be related to a phase separation into bromide- and iodide-rich phases. We also observe a partially reversible formation of metallic lead in the perovskite structure. These processes occur on the time scale of minutes during illumination. The presented methodology has a large potential for understanding light-induced chemistry in photoactive materials and could specifically be extended to systematically study the impact of morphology and composition on the photostability of metal halide perovskites.}, language = {en} } @article{deWiljesReichStannat2018, author = {de Wiljes, Jana and Reich, Sebastian and Stannat, Wilhelm}, title = {Long-Time stability and accuracy of the ensemble Kalman-Bucy Filter for fully observed processes and small measurement noise}, series = {SIAM Journal on Applied Dynamical Systems}, volume = {17}, journal = {SIAM Journal on Applied Dynamical Systems}, number = {2}, publisher = {Society for Industrial and Applied Mathematics}, address = {Philadelphia}, issn = {1536-0040}, doi = {10.1137/17M1119056}, pages = {1152 -- 1181}, year = {2018}, abstract = {The ensemble Kalman filter has become a popular data assimilation technique in the geosciences. However, little is known theoretically about its long term stability and accuracy. In this paper, we investigate the behavior of an ensemble Kalman-Bucy filter applied to continuous-time filtering problems. We derive mean field limiting equations as the ensemble size goes to infinity as well as uniform-in-time accuracy and stability results for finite ensemble sizes. The later results require that the process is fully observed and that the measurement noise is small. We also demonstrate that our ensemble Kalman-Bucy filter is consistent with the classic Kalman-Bucy filter for linear systems and Gaussian processes. We finally verify our theoretical findings for the Lorenz-63 system.}, language = {en} } @article{KasmiZouhalHammamietal.2021, author = {Kasmi, Sofien and Zouhal, Hassane and Hammami, Raouf and Clark, Cain Craig Truman and Hackney, Anthony C. and Hammami, Amri and Chtara, Moktar and Chortane, Sabri Gaied and Ben Salah, Fatma Zohra and Granacher, Urs and Ben Ounis, Omar}, title = {The Effects of Eccentric and Plyometric Training Programs and Their Combination on Stability and the Functional Performance in the Post-ACL-Surgical Rehabilitation Period of Elite Female Athletes}, series = {Frontiers in physiology}, volume = {12}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne, Schweiz}, issn = {1664-042X}, doi = {10.3389/fphys.2021.688385}, pages = {1 -- 11}, year = {2021}, abstract = {Background: The standard method to treat physically active patients with anterior cruciate ligament (ACL) rupture is ligament reconstruction surgery. The rehabilitation training program is very important to improve functional performance in recreational athletes following ACL reconstruction. Objectives: The aims of this study were to compare the effects of three different training programs, eccentric training (ECC), plyometric training (PLYO), or combined eccentric and plyometric training (COMB), on dynamic balance (Y-BAL), the Lysholm Knee Scale (LKS), the return to sport index (RSI), and the leg symmetry index (LSI) for the single leg hop test for distance in elite female athletes after ACL surgery. Materials and Methods: Fourteen weeks after rehabilitation from surgery, 40 elite female athletes (20.3 ± 3.2 years), who had undergone an ACL reconstruction, participated in a short-term (6 weeks; two times a week) training study. All participants received the same rehabilitation protocol prior to the training study. Athletes were randomly assigned to three experimental groups, ECC (n = 10), PLYO (n = 10), and COMB (n = 10), and to a control group (CON: n = 10). Testing was conducted before and after the 6-week training programs and included the Y-BAL, LKS, and RSI. LSI was assessed after the 6-week training programs only. Results: Adherence rate was 100\% across all groups and no training or test-related injuries were reported. No significant between-group baseline differences (pre-6-week training) were observed for any of the parameters. Significant group-by-time interactions were found for Y-BAL (p < 0.001, ES = 1.73), LKS (p < 0.001, ES = 0.76), and RSI (p < 0.001, ES = 1.39). Contrast analysis demonstrated that COMB yielded significantly greater improvements in Y-BAL, LKS, and RSI (all p < 0.001), in addition to significantly better performances in LSI (all p < 0.001), than CON, PLYO, and ECC, respectively. Conclusion: In conclusion, combined (eccentric/plyometric) training seems to represent the most effective training method as it exerts positive effects on both stability and functional performance in the post-ACL-surgical rehabilitation period of elite female athletes.}, language = {en} } @article{KhajooeiWochatzBaritelloetal.2020, author = {Khajooei, Mina and Wochatz, Monique and Baritello, Omar and Mayer, Frank}, title = {Effects of shoes on children's fundamental motor skills performance}, series = {Footwear science : official journal of the Footwear Biomechanics Group}, volume = {12}, journal = {Footwear science : official journal of the Footwear Biomechanics Group}, number = {1}, publisher = {Taylor \& Francis}, address = {Abingdon}, issn = {1942-4280}, doi = {10.1080/19424280.2019.1696895}, pages = {55 -- 62}, year = {2020}, abstract = {Progression or impediment of fundamental motor skills performance (FMSP) in children depends on internal and environmental factors. Shoes as an environmental constraint are believed to affect these movements as children showed to perform qualitatively better with sports shoes than flip-flop sandals. However, locomotor performance assessments based on biomechanical variables are limited. Therefore, the objective of this experiment was to assess the biomechanical effects of wearing shoes while performing fundamental motor skills in children. Barefoot and shod conditions were tested in healthy children between the age of 4 and 7 years. They were asked to perform basic and advanced motor skills including double-leg stance, horizontal jumps, walking as well as counter-movement jumps, single-leg stance and sprinting. Postural control and ground reaction data were measured with two embedded force plates. A 3D motion capture system was used to analyse the spatiotemporal parameters of walking and sprinting. Findings showed that the parameters of single- and double-leg stance, horizontal and counter-movement jump did not differ between barefoot and shod conditions. Most of the spatiotemporal variables including cadence, stride length, stride time, and contact time of walking and sprinting were statistically different between the barefoot and shod conditions. Consequently, tested shoes did not change performance and biomechanics of postural control and jumping tasks; however, the spatiotemporal gait parameters indicate changes in walking and sprinting characteristics with shoes in children.}, language = {en} } @article{KielarXinXuetal.2019, author = {Kielar, Charlotte and Xin, Yang and Xu, Xiaodan and Zhu, Siqi and Gorin, Nelli and Grundmeier, Guido and M{\"o}ser, Christin and Smith, David M. and Keller, Adrian}, title = {Effect of staple age on DNA origami nanostructure assembly and stability}, series = {Molecules}, volume = {24}, journal = {Molecules}, number = {14}, publisher = {MDPI}, address = {Basel}, issn = {1420-3049}, doi = {10.3390/molecules24142577}, pages = {12}, year = {2019}, abstract = {DNA origami nanostructures are widely employed in various areas of fundamental and applied research. Due to the tremendous success of the DNA origami technique in the academic field, considerable efforts currently aim at the translation of this technology from a laboratory setting to real-world applications, such as nanoelectronics, drug delivery, and biosensing. While many of these real-world applications rely on an intact DNA origami shape, they often also subject the DNA origami nanostructures to rather harsh and potentially damaging environmental and processing conditions. Furthermore, in the context of DNA origami mass production, the long-term storage of DNA origami nanostructures or their pre-assembled components also becomes an issue of high relevance, especially regarding the possible negative effects on DNA origami structural integrity. Thus, we investigated the effect of staple age on the self-assembly and stability of DNA origami nanostructures using atomic force microscopy. Different harsh processing conditions were simulated by applying different sample preparation protocols. Our results show that staple solutions may be stored at -20 degrees C for several years without impeding DNA origami self-assembly. Depending on DNA origami shape and superstructure, however, staple age may have negative effects on DNA origami stability under harsh treatment conditions. Mass spectrometry analysis of the aged staple mixtures revealed no signs of staple fragmentation. We, therefore, attribute the increased DNA origami sensitivity toward environmental conditions to an accumulation of damaged nucleobases, which undergo weaker base-pairing interactions and thus lead to reduced duplex stability.}, language = {en} } @article{LiAbdulkadirSchattenbergetal.2022, author = {Li, Shuang and Abdulkadir, Nafi'u and Schattenberg, Florian and da Rocha, Ulisses Nunes and Grimm, Volker and M{\"u}ller, Susann and Liu, Zishu}, title = {Stabilizing microbial communities by looped mass transfer}, series = {Proceedings of the National Academy of Sciences of the United States of America : PNAS}, volume = {119}, journal = {Proceedings of the National Academy of Sciences of the United States of America : PNAS}, number = {17}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.2117814119}, pages = {11}, year = {2022}, abstract = {Building and changing a microbiome at will and maintaining it over hundreds of generations has so far proven challenging. Despite best efforts, complex microbiomes appear to be susceptible to large stochastic fluctuations. Current capabilities to assemble and control stable complex microbiomes are limited. Here, we propose a looped mass transfer design that stabilizes microbiomes over long periods of time. Five local microbiomes were continuously grown in parallel for over 114 generations and connected by a loop to a regional pool. Mass transfer rates were altered and microbiome dynamics were monitored using quantitative high-throughput flow cytometry and taxonomic sequencing of whole communities and sorted subcommunities. Increased mass transfer rates reduced local and temporal variation in microbiome assembly, did not affect functions, and overcame stochasticity, with all microbiomes exhibiting high constancy and increasing resistance. Mass transfer synchronized the structures of the five local microbiomes and nestedness of certain cell types was eminent. Mass transfer increased cell number and thus decreased net growth rates mu'. Subsets of cells that did not show net growth mu'SCx were rescued by the regional pool R and thus remained part of the microbiome. The loop in mass transfer ensured the survival of cells that would otherwise go extinct, even if they did not grow in all local microbiomes or grew more slowly than the actual dilution rate D would allow. The rescue effect, known from metacommunity theory, was the main stabilizing mechanism leading to synchrony and survival of subcommunities, despite differences in cell physiological properties, including growth rates.}, language = {en} } @article{LilieBaerKettneretal.2011, author = {Lilie, Hauke and Baer, Dorit and Kettner, Karina and Weininger, Ulrich and Balbach, Jochen and Naumann, Manfred and Mueller, Eva-Christina and Otto, Albrecht and Gast, Klaus and Golbik, Ralph and Kriegel, Thomas}, title = {Yeast hexokinase isoenzyme ScHxk2 stability of a two-domain protein with discontinuous domains}, series = {Protein engineering design \& selection}, volume = {24}, journal = {Protein engineering design \& selection}, number = {1-2}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1741-0126}, doi = {10.1093/protein/gzq098}, pages = {79 -- 87}, year = {2011}, abstract = {The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40\% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional H-1 NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about Delta G = -22 kJ mol(-1).}, language = {en} } @article{RaatzvanVelzenGaedke2019, author = {Raatz, Michael and van Velzen, Ellen and Gaedke, Ursula}, title = {Co-adaptation impacts the robustness of predator-prey dynamics against perturbations}, series = {Ecology and Evolution}, volume = {9}, journal = {Ecology and Evolution}, number = {7}, publisher = {John Wiley \& Sons}, address = {Hoboken, NJ}, issn = {2045-7758}, doi = {10.1002/ece3.5006}, pages = {3823 -- 3836}, year = {2019}, abstract = {Global change threatens the maintenance of ecosystem functions that are shaped by the persistence and dynamics of populations. It has been shown that the persistence of species increases if they possess larger trait adaptability. Here, we investigate whether trait adaptability also affects the robustness of population dynamics of interacting species and thereby shapes the reliability of ecosystem functions that are driven by these dynamics. We model co-adaptation in a predator-prey system as changes to predator offense and prey defense due to evolution or phenotypic plasticity. We investigate how trait adaptation affects the robustness of population dynamics against press perturbations to environmental parameters and against pulse perturbations targeting species abundances and their trait values. Robustness of population dynamics is characterized by resilience, elasticity, and resistance. In addition to employing established measures for resilience and elasticity against pulse perturbations (extinction probability and return time), we propose the warping distance as a new measure for resistance against press perturbations, which compares the shapes and amplitudes of pre- and post-perturbation population dynamics. As expected, we find that the robustness of population dynamics depends on the speed of adaptation, but in nontrivial ways. Elasticity increases with speed of adaptation as the system returns more rapidly to the pre-perturbation state. Resilience, in turn, is enhanced by intermediate speeds of adaptation, as here trait adaptation dampens biomass oscillations. The resistance of population dynamics strongly depends on the target of the press perturbation, preventing a simple relationship with the adaptation speed. In general, we find that low robustness often coincides with high amplitudes of population dynamics. Hence, amplitudes may indicate the robustness against perturbations also in other natural systems with similar dynamics. Our findings show that besides counteracting extinctions, trait adaptation indeed strongly affects the robustness of population dynamics against press and pulse perturbations.}, language = {en} } @article{RentzschSchroederAbe2018, author = {Rentzsch, Katrin and Schr{\"o}der-Abe, Michela}, title = {Stability and change in domain-specific Self-esteem and global self-esteem}, series = {European journal of personality}, volume = {32}, journal = {European journal of personality}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {0890-2070}, doi = {10.1002/per.2167}, pages = {353 -- 370}, year = {2018}, abstract = {A notable uptick of interest in the stability of self-esteem has been observed over the past few years. Most researchers, however, have focused on unidimensional rather than multidimensional conceptualizations of self-esteem. The paucity of empirical research is surprising given conflicting theoretical perspectives on the stability of self-esteem. The goal of the present study was to thoroughly disentangle different conceptualizations of self-esteem and test opposing classical theories on (i) the stability and (ii) the direction of mutual influence of these different forms of self-esteem. We analysed two-year longitudinal data from participants (N=644 at T1, N=241 at T2) with an average age of 47.0years (SD=12.4). Analyses using a latent variable approach revealed that the domains of self-esteem were relatively stable in terms of rank order and mean levels. In fact, the size of the stability coefficients was comparable to that of other trait measures that have been reported in the literature and paralleled the stability observed for global self-esteem. Results did not provide support for either top-down or bottom-up effects between domain-specific and global self-esteem. These findings have important theoretical and practical implications regarding the stability and development of self-esteem in adulthood and advance the understanding of self-esteem in personality theory. (c) 2018 European Association of Personality Psychology}, language = {en} } @article{RentzschSchroederAbe2022, author = {Rentzsch, Katrin and Schr{\"o}der-Ab{\´e}, Michela}, title = {Top down or bottom up?}, series = {Journal of personality and social psychology / American Psychological Association}, volume = {122}, journal = {Journal of personality and social psychology / American Psychological Association}, number = {4}, publisher = {American Psychological Association}, address = {Washington}, issn = {0022-3514}, doi = {10.1037/pspp0000393}, pages = {714 -- 730}, year = {2022}, abstract = {Classical theoretical perspectives have implied that either global self-esteem has an impact on domain-specific self-esteem (top-down) or domain-specific self-esteem affects global self-esteem (bottom-up). The goal of the present research was to investigate whether classical top-down and bottom-up approaches could withstand a thorough test. To do so, we applied elaborate analytical methods in a four-wave longitudinal study across 6 years with preregistered hypotheses and data analyses. We analyzed data from N = 1,417 German participants (30.6\% men, median of 12 to 13 years of education) with an average age of 47.0 years (SD = 12.4, range 18 to 88) at intake. Analyses using latent variable approaches for modeling intraindividual change provided evidence of top-down effects only. For example, participants with higher global self-esteem exhibited an increase in performance self-esteem but not vice versa. Our results also provided evidence of "vertical" associations between global and domain-specific self-esteem, that is, parallel development within the same time frame. In addition, the analyses revealed high rank order stability and a substantial trait component in global self-esteem and the self-esteem domains. The present findings have important theoretical and practical implications for the stability and development of self-esteem in adulthood and advance the understanding of global and domain-specific self-esteem in personality theory.}, language = {en} }