TY - THES A1 - Prüfer, Nicole T1 - Untersuchungen zur pro-inflammatorischen Wirkung von Serum-Amyloid A in glatten Gefäßmuskelzellen BT - Identifizierung der Signalwege Y1 - 2014 ER - TY - JOUR A1 - Diez, Isabel A1 - Tauer, Klaus A1 - Schulz, Burkhard T1 - Unusual polymer dispersions-polypyrrole suspensions made of rings, frames, and platelets JF - Colloid and polymer science : official journal of the Kolloid-Gesellschaft N2 - Experimental results show that the polymerization of pyrrole in the presence of beta-naphthalenesulfonic acid and different fluorosurfactants like perfluorooctanesulfonic acid, perfluorooctyldiethanolamide, and ammonium perfluorooctanoate leads to polypyrrole with special morphologies, such as rings or disks and rectangular frames or plates. The formation of these unusually shaped particles of polymer dispersions is explained by the chemical and colloidal peculiarities of the oxidative pyrrole polymerization with ammonium peroxodisulfate in aqueous medium. KW - polypyrrole KW - chemical oxidative polymerization KW - particle morphology Y1 - 2006 U6 - https://doi.org/10.1007/s00396-006-1521-8 SN - 0303-402X VL - 284 SP - 1431 EP - 1442 PB - Springer CY - New York ER - TY - JOUR A1 - Markötter, Henning A1 - Sintschuk, Michael A1 - Britzke, Ricardo A1 - Dayani, Shahabeddin A1 - Bruno, Giovanni T1 - Upgraded imaging capabilities at the BAMline (BESSY II) JF - Journal of synchrotron radiation N2 - The BAMline at the BESSY II synchrotron X-ray source has enabled research for more than 20 years in widely spread research fields such as materials science, biology, cultural heritage and medicine. As a nondestructive characterization method, synchrotron X-ray imaging, especially tomography, plays a particularly important role in structural characterization. A recent upgrade of key equipment of the BAMline widens its imaging capabilities: shorter scan acquisition times are now possible, in situ and op erando studies can now be routinely performed, and different energy spectra can easily be set up. In fact, the upgraded double-multilayer monochromator brings full flexibility by yielding different energy spectra to optimize flux and energy resolution as desired. The upgraded detector (based on an sCMOS camera) also allows exploiting the higher flux with reduced readout times. Furthermore, an installed slip ring allows the sample stage to continuously rotate. The latter feature enables tomographic observation of processes occurring in the time scale of a few seconds. KW - synchrotron radiation KW - computed tomography KW - double-multilayer monochromators KW - pink beams KW - X-ray optics Y1 - 2022 U6 - https://doi.org/10.1107/S1600577522007342 SN - 1600-5775 VL - 29 IS - 5 SP - 1292 EP - 1298 PB - International Union of Crystallography CY - Chester ER - TY - JOUR A1 - Abdalla, Hassan E. A1 - Aharonian, Felix A. A1 - Benkhali, F. Ait A1 - Anguener, E. O. A1 - Arakawa, M. A1 - Arcaro, C. A1 - Armand, C. A1 - Ashkar, H. A1 - Backes, M. A1 - Martins, V. Barbosa A1 - Barnard, M. A1 - Becherini, Y. A1 - Berge, D. A1 - Bernloehr, K. A1 - Blackwell, R. A1 - Boettcher, M. A1 - Boisson, C. A1 - Bolmont, J. A1 - Bonnefoy, S. A1 - Bregeon, J. A1 - Breuhaus, M. A1 - Brun, F. A1 - Brun, P. A1 - Bryan, M. A1 - Buechele, M. A1 - Bulik, T. A1 - Bylund, T. A1 - Capasso, M. A1 - Caroff, S. A1 - Carosi, A. A1 - Casanova, Sabrina A1 - Cerruti, M. A1 - Chakraborty, N. A1 - Chand, T. A1 - Chandra, S. A1 - Chaves, R. C. G. A1 - Chen, A. A1 - Colafrancesco, S. A1 - Curylo, M. A1 - Davids, I. D. A1 - Deil, C. A1 - Devin, J. A1 - de Wilt, P. A1 - Dirson, L. A1 - Djannati-Atai, A. A1 - Dmytriiev, A. A1 - Donath, A. A1 - Doroshenko, V A1 - Dyks, J. A1 - Egberts, Kathrin A1 - Emery, G. A1 - Ernenwein, J-p A1 - Eschbach, S. A1 - Feijen, K. A1 - Fegan, S. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Funk, S. A1 - Fuessling, M. A1 - Gabici, S. A1 - Gallant, Y. A. A1 - Gate, F. A1 - Giavitto, G. A1 - Glawion, D. A1 - Glicenstein, J. F. A1 - Gottschall, D. A1 - Grondin, M-H A1 - Hahn, J. A1 - Haupt, M. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hoischen, Clemens A1 - Holch, Tim Lukas A1 - Holler, M. A1 - Horns, D. A1 - Huber, D. A1 - Iwasaki, H. A1 - Jamrozy, M. A1 - Jankowsky, D. A1 - Jankowsky, F. A1 - Jung-Richardt, I A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katsuragawa, M. A1 - Katz, U. A1 - Khangulyan, D. A1 - Khelifi, B. A1 - King, J. A1 - Klepser, S. A1 - Kluzniak, W. A1 - Komin, Nu A1 - Kosack, K. A1 - Kostunin, D. A1 - Kraus, M. A1 - Lamanna, G. A1 - Lau, J. A1 - Lemiere, A. A1 - Lemoine-Goumard, M. A1 - Lenain, J-P A1 - Leser, Eva A1 - Levy, C. A1 - Lohse, T. A1 - Lopez-Coto, R. A1 - Lypova, I A1 - Mackey, J. A1 - Majumdar, J. A1 - Malyshev, D. A1 - Marandon, V A1 - Marcowith, Alexandre A1 - Mares, A. A1 - Mariaud, C. A1 - Marti-Devesa, G. A1 - Marx, R. A1 - Maurin, G. A1 - Meintjes, P. J. A1 - Mitchell, A. M. W. A1 - Moderski, R. A1 - Mohamed, M. A1 - Mohrmann, L. A1 - Muller, J. A1 - Moore, C. A1 - Moulin, Emmanuel A1 - Murach, T. A1 - Nakashima, S. A1 - de Naurois, M. A1 - Ndiyavala, H. A1 - Niederwanger, F. A1 - Niemiec, J. A1 - Oakes, L. A1 - Odaka, H. A1 - Ohm, S. A1 - Wilhelmi, E. de Ona A1 - Ostrowski, M. A1 - Oya, I A1 - Panter, M. A1 - Parsons, R. D. A1 - Perennes, C. A1 - Petrucci, P-O A1 - Peyaud, B. A1 - Piel, Q. A1 - Pita, S. A1 - Poireau, V A1 - Noel, A. Priyana A1 - Prokhorov, D. A. A1 - Prokoph, H. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Rauth, R. A1 - Reimer, A. A1 - Reimer, O. A1 - Remy, Q. A1 - Renaud, M. A1 - Rieger, F. A1 - Rinchiuso, L. A1 - Romoli, C. A1 - Rowell, G. A1 - Rudak, B. A1 - Ruiz-Velasco, E. A1 - Sahakian, V A1 - Saito, S. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Sasaki, M. A1 - Schlickeiser, R. A1 - Schussler, F. A1 - Schulz, A. A1 - Schutte, H. A1 - Schwanke, U. A1 - Schwemmer, S. A1 - Seglar-Arroyo, M. A1 - Senniappan, M. A1 - Seyffert, A. S. A1 - Shafi, N. A1 - Shiningayamwe, K. A1 - Simoni, R. A1 - Sinha, A. A1 - Sol, H. A1 - Specovius, A. A1 - Spir-Jacob, M. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Steppa, Constantin Beverly A1 - Takahashi, T. A1 - Tavernier, T. A1 - Taylor, A. M. A1 - Terrier, R. A1 - Tiziani, D. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Tsirou, M. A1 - Tsuji, N. A1 - Tuffs, R. A1 - Uchiyama, Y. A1 - van der Walt, D. J. A1 - van Eldik, C. A1 - van Rensburg, C. A1 - van Soelen, B. A1 - Vasileiadis, G. A1 - Veh, J. A1 - Venter, C. A1 - Vincent, P. A1 - Vink, J. A1 - Voisin, F. A1 - Voelk, H. J. A1 - Vuillaume, T. A1 - Wadiasingh, Z. A1 - Wagner, S. J. A1 - White, R. A1 - Wierzcholska, A. A1 - Yang, R. A1 - Yoneda, H. A1 - Zacharias, M. A1 - Zanin, R. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Ziegler, A. A1 - Zorn, J. A1 - Zywucka, N. A1 - Maxted, N. T1 - Upper limits on very-high-energy gamma-ray emission from core-collapse supernovae observed with H.E.S.S. JF - Astronomy and astrophysics : an international weekly journal N2 - Young core-collapse supernovae with dense-wind progenitors may be able to accelerate cosmic-ray hadrons beyond the knee of the cosmic-ray spectrum, and this may result in measurable gamma-ray emission. We searched for gamma-ray emission from ten super- novae observed with the High Energy Stereoscopic System (H.E.S.S.) within a year of the supernova event. Nine supernovae were observed serendipitously in the H.E.S.S. data collected between December 2003 and December 2014, with exposure times ranging from 1.4 to 53 h. In addition we observed SN 2016adj as a target of opportunity in February 2016 for 13 h. No significant gamma-ray emission has been detected for any of the objects, and upper limits on the >1 TeV gamma-ray flux of the order of similar to 10(-13) cm(-)(2)s(-1) are established, corresponding to upper limits on the luminosities in the range similar to 2 x 10(39) to similar to 1 x 10(42) erg s(-1). These values are used to place model-dependent constraints on the mass-loss rates of the progenitor stars, implying upper limits between similar to 2 x 10(-5) and similar to 2 x 10(-3) M-circle dot yr(-1) under reasonable assumptions on the particle acceleration parameters. KW - gamma rays: general KW - supernovae: general KW - cosmic rays Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201935242 SN - 1432-0746 VL - 626 PB - EDP Sciences CY - Les Ulis ER - TY - THES A1 - Svirejeva-Hopkins, Anastasia T1 - Urbanised territories as a specific component of the global carbon cycle N2 - Wir betrachten folgende Teile: die zusätzlichen Kohlenstoff(C)-emissionen, welche aus der Umwandlung von natürlichem Umland durch Stadtwachstum resultieren, und die Änderung des C-Flusses durch 'urbanisierte' Ökosysteme, soweit atmosphärisches C durch diese in umliegende natürliche Ökosysteme entlang der Kette “Atmosphäre -> Vegetation -> abgestorbene organische Substanzen” gepumpt wird: d.h. C-Export; für den Zeitraum von 1980 bis 2050. Als Szenario nutzen wir Prognosen der regionalen Stadtbevölkerung, welche durch ein 'Hybridmodell' generiert werden für acht Regionen. Alle Schätzungen der C-Flüsse basieren auf zwei Modellen: das Regression Modell und das sogenannte G-Modell. Die Siedlungsfläche, welche mit dem Wachstum der Stadtbevölkerung zunimmt, wird in 'Grünflächen' (Parks, usw.), Gebäudeflächen und informell städtisch genutzte Flächen (Slums, illegale Lagerplätze, usw.) unterteilt. Es werden jährlich die regionale und globale Dynamik der C-Emissionen und des C-Exports sowie die C-Gesamtbilanz berechnet. Dabei liefern beide Modelle qualitativ ähnliche Ergebnisse, jedoch gibt es einige quantitative Unterschiede. Im ersten Modell erreicht die globale Jahresemission für die Dekade 2020-2030 resultierend aus der Landnutzungsänderung ein Maximum von 205 Mt/a. Die maximalen Beiträge zur globalen Emission werden durch China, die asiatische und die pazifische Region erbracht. Im zweiten Modell erhöht sich die jährliche globale Emission von 1.12 GtC/a für 1980 auf 1.25 GtC/a für 2005 (1Gt = 109 t). Danach beginnt eine Reduzierung. Vergleichen wir das Emissionmaximum mit der Emission durch Abholzung im Jahre 1980 (1.36 GtC/a), können wir konstatieren, daß die Urbanisierung damit in vergleichbarer Grösse zur Emission beiträgt. Bezogen auf die globale Dynamik des jährlichen C-Exports durch Urbanisierung beobachten wir ein monotones Wachstum bis zum nahezu dreifachen Wert von 24 MtC/a für 1980 auf 66 MtC/a für 2050 im ersten Modell, bzw. im zweiten Modell von 249 MtC/a für 1980 auf 505 MtC/a für 2050. Damit ist im zweiten Fall die Transportleistung der Siedlungsgebiete mit dem C-Transport durch Flüsse in die Ozeane (196 .. 537 MtC/a) vergleichbar. Bei der Abschätzung der Gesamtbilanz finden wir, daß die Urbanisierung die Bilanz in Richtung zu einer 'Senke' verschiebt. Entsprechend dem zweiten Modell beginnt sich die C-Gesamtbilanz (nach annähernder Konstanz) ab dem Jahre 2000 mit einer fast konstanten Rate zu verringern. Wenn das Maximum im Jahre 2000 bei 905MtC/a liegt, fällt dieser Wert anschliessend bis zum Jahre 2050 auf 118 MtC/a. Bei Extrapolation dieser Dynamik in die Zukunft können wir annehmen, daß am Ende des 21. Jahrhunderts die “urbane” C-Gesamtbilanz Null bzw. negative Werte erreicht. N2 - We calculate the additional carbon emissions as a result of the conversion of natural land in a process of urbanisation; and the change of carbon flows by “urbanised” ecosystems, when the atmospheric carbon is exported to the neighboring territories, from 1980 till 2050 for the eight regions of the world. As a scenario we use combined UN and demographic model′s prognoses for regional total and urban population growth. The calculations of urban areas dynamics are based on two models: the regression model and the Gamma-model. The urbanised area is sub-divided on built-up, „green“ (parks, etc.) and informal settlements (favelas) areas. The next step is to calculate the regional and world dynamics of carbon emission and export, and the annual total carbon balance. Both models give similar results with some quantitative differences. In the first model, the world annual emissions attain a maximum of 205 MtC/year between 2020-2030. Emissions will then slowly decrease. The maximum contributions are given by China and the Asia and Pacific regions. In the second model, world annual emissions increase to 1.25 GtC in 2005, beginning to decrease afterwards. If we compare the emission maximum with the annual emission caused by deforestation, 1.36GtC per year, then we can say that the role of urbanised territories (UT) is of a comparable magnitude. Regarding the world annual export of carbon by UT, we observe its monotonous growth by three times, from 24 MtC to 66 MtC in the first model, and from 249 MtC to 505 MtC in the second one. The latter, is therefore comparable to the amount of carbon transported by rivers into the ocean (196-537 MtC). By estimating the total balance we find that urbanisation shifts the total balance towards a “sink” state. The urbanisation is inhibited in the interval 2020-2030, and by 2050 the growth of urbanised areas would almost stop. Hence, the total emission of natural carbon at that stage will stabilise at the level of the 1980s (80 MtC per year). As estimated by the second model, the total balance, being almost constant until 2000, then starts to decrease at an almost constant rate. We can say that by the end of the XXI century, the total carbon balance will be equal to zero, when the exchange flows are fully balanced, and may even be negative, when the system begins to take up carbon from the atmosphere, i.e., becomes a “sink”. T2 - Urbanised territories as a specific component of the global carbon cycle KW - Urbanisierung KW - C-Senke KW - Bilanz KW - Kohlenstoffzyklus KW - Städte KW - C-Fluss KW - Slums KW - Vegetation KW - Verteilung KW - urban KW - land conversion KW - carbon KW - sink KW - cities KW - urbanisation KW - emissions KW - favela KW - regional KW - population KW - density KW - distribution KW - flux KW - vegetation Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0001512 ER - TY - JOUR A1 - Teichmann, Erik T1 - Using phase dynamics to study partial synchrony BT - three examples JF - European physical journal special topics N2 - Partial synchronous states appear between full synchrony and asynchrony and exhibit many interesting properties. Most frequently, these states are studied within the framework of phase approximation. The latter is used ubiquitously to analyze coupled oscillatory systems. Typically, the phase dynamics description is obtained in the weak coupling limit, i.e., in the first-order in the coupling strength. The extension beyond the first-order represents an unsolved problem and is an active area of research. In this paper, three partially synchronous states are investigated and presented in order of increasing complexity. First, the usage of the phase response curve for the description of macroscopic oscillators is analyzed. To achieve this, the response of the mean-field oscillations in a model of all-to-all coupled limit-cycle oscillators to pulse stimulation is measured. The next part treats a two-group Kuramoto model, where the interaction of one attractive and one repulsive group results in an interesting solitary state, situated between full synchrony and self-consistent partial synchrony. In the last part, the phase dynamics of a relatively simple system of three Stuart-Landau oscillators are extended beyond the weak coupling limit. The resulting model contains triplet terms in the high-order phase approximation, though the structural connections are only pairwise. Finally, the scaling of the new terms with the coupling is analyzed. Y1 - 2021 U6 - https://doi.org/10.1140/epjs/s11734-021-00156-3 SN - 1951-6355 SN - 1951-6401 VL - 230 IS - 14-15 SP - 2833 EP - 2842 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Laquai, Rene A1 - Müller, Bernd R. A1 - Schneider, Judith Ann A1 - Kupsch, Andreas A1 - Bruno, Giovanni T1 - Using SXRR to probe the nature of discontinuities in SLM additive manufactured inconel 718 specimens JF - Metallurgical and Materials Transactions A N2 - The utilization of additive manufacturing (AM) to fabricate robust structural components relies on understanding the nature of internal anomalies or discontinuities, which can compromise the structural integrity. While some discontinuities in AM microstructures stem from similar mechanisms as observed in more traditional processes such as casting, others are unique to the AM process. Discontinuities in AM are challenging to detect, due to their submicron size and orientation dependency. Toward the goal of improving structural integrity, minimizing discontinuities in an AM build requires an understanding of the mechanisms of formation to mitigate their occurrence. This study utilizes various techniques to evaluate the shape, size, nature and distribution of discontinuities in AM Inconel 718, in a non-hot isostatic pressed (HIPed) as-built, non-HIPed and direct age, and HIPed with two step age samples. Non-destructive synchrotron radiation refraction and transmission radiography (SXRR) provides additional information beyond that obtained with destructive optical microscopy. SXRR was able to distinguish between voids, cracks and lack of melt in, due to its sensitivity to the orientation of the discontinuity. Y1 - 2020 U6 - https://doi.org/10.1007/s11661-020-05847-5 SN - 1073-5623 SN - 1543-1940 VL - 51 IS - 8 SP - 4146 EP - 4157 PB - Springer CY - New York ER - TY - JOUR A1 - Wulff, Peter A1 - Mientus, Lukas A1 - Nowak, Anna A1 - Borowski, Andreas T1 - Utilizing a pretrained language model (BERT) to classify preservice physics teachers' written reflections JF - International journal of artificial intelligence in education N2 - Computer-based analysis of preservice teachers' written reflections could enable educational scholars to design personalized and scalable intervention measures to support reflective writing. Algorithms and technologies in the domain of research related to artificial intelligence have been found to be useful in many tasks related to reflective writing analytics such as classification of text segments. However, mostly shallow learning algorithms have been employed so far. This study explores to what extent deep learning approaches can improve classification performance for segments of written reflections. To do so, a pretrained language model (BERT) was utilized to classify segments of preservice physics teachers' written reflections according to elements in a reflection-supporting model. Since BERT has been found to advance performance in many tasks, it was hypothesized to enhance classification performance for written reflections as well. We also compared the performance of BERT with other deep learning architectures and examined conditions for best performance. We found that BERT outperformed the other deep learning architectures and previously reported performances with shallow learning algorithms for classification of segments of reflective writing. BERT starts to outperform the other models when trained on about 20 to 30% of the training data. Furthermore, attribution analyses for inputs yielded insights into important features for BERT's classification decisions. Our study indicates that pretrained language models such as BERT can boost performance for language-related tasks in educational contexts such as classification. KW - Reflective writing KW - NLP KW - Deep learning KW - Science education Y1 - 2022 U6 - https://doi.org/10.1007/s40593-022-00290-6 SN - 1560-4292 SN - 1560-4306 IS - 33 SP - 439 EP - 466 PB - Springer CY - New York ER - TY - JOUR A1 - Kontro, Inkeri A1 - Buschhüter, David T1 - Validity of Colorado Learning Attitudes about Science Survey for a high-achieving, Finnish population JF - Physical review. Physics education research N2 - The Colorado Learning Attitudes about Science Survey (CLASS) is an instrument which is widely used in physics education to characterize students' attitudes toward physics and learning physics and compare them with those of experts. While CLASS has been extensively validated for use in the context of higher education institutions in the United States, there has been less information about its use with European students. We have studied the structural, content, and substantive aspects of validity of CLASS by first doing a confirmatory factor analysis of N = 642 sets of student answers from the University of Helsinki, Finland. The students represented a culturally and demographically different subset of university physics students than in previous studies. The confirmatory factor analysis used a 3-factor, 15-item factor structure as a starting point and the resulting factor structure was similar to the original. Just minor modifications were needed for fit parameters to be in the acceptable range. We explored the differences by student interviews and consultation of experts. With the exception of one item, they supported the new 14-item, 3-factor structure. The results show that the interpretations made from CLASS results are mostly transferable, and CLASS remains a useful instrument for a wide variety of populations. Y1 - 2020 U6 - https://doi.org/10.1103/PhysRevPhysEducRes.16.020104 SN - 2469-9896 VL - 16 IS - 2 PB - American Physical Society CY - College Park, MD ER - TY - JOUR A1 - Pulkkinen, Otto A1 - Metzler, Ralf T1 - Variance-corrected Michaelis-Menten equation predicts transient rates of single-enzyme reactions and response times in bacterial gene-regulation JF - Scientific reports N2 - Many chemical reactions in biological cells occur at very low concentrations of constituent molecules. Thus, transcriptional gene-regulation is often controlled by poorly expressed transcription-factors, such as E.coli lac repressor with few tens of copies. Here we study the effects of inherent concentration fluctuations of substrate-molecules on the seminal Michaelis-Menten scheme of biochemical reactions. We present a universal correction to the Michaelis-Menten equation for the reaction-rates. The relevance and validity of this correction for enzymatic reactions and intracellular gene-regulation is demonstrated. Our analytical theory and simulation results confirm that the proposed variance-corrected Michaelis-Menten equation predicts the rate of reactions with remarkable accuracy even in the presence of large non-equilibrium concentration fluctuations. The major advantage of our approach is that it involves only the mean and variance of the substrate-molecule concentration. Our theory is therefore accessible to experiments and not specific to the exact source of the concentration fluctuations. Y1 - 2015 U6 - https://doi.org/10.1038/srep17820 SN - 2045-2322 IS - 5 PB - Nature Publishing Group CY - London ER -