@book{OPUS4-6251, title = {Grammatica Grandonica}, editor = {Van Hal, Toon and Vielle, Christophe}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63218}, publisher = {Universit{\"a}t Potsdam}, pages = {280}, year = {2013}, abstract = {In May 2010, Johann Ernst Hanxleden's Grammatica Grandonica was rediscovered in Montecompatri (Lazio, Rome). Although historiographers attached much weight to the nearly oldest western grammar of Sanskrit, the precious manuscript was lost for several decades. The first aim of the present digital publication is to offer a photographical reproduction of the manuscript. This facsimile is accompanied by a double edition: a facing diplomatic edition with the Sanskrit in Malayāḷam script, followed by a transliterated established text.}, language = {en} } @phdthesis{Ziege2022, author = {Ziege, Ricardo}, title = {Growth dynamics and mechanical properties of E. coli biofilms}, doi = {10.25932/publishup-55986}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-559869}, school = {Universit{\"a}t Potsdam}, pages = {xi, 123}, year = {2022}, abstract = {Biofilms are complex living materials that form as bacteria get embedded in a matrix of self-produced protein and polysaccharide fibres. The formation of a network of extracellular biopolymer fibres contributes to the cohesion of the biofilm by promoting cell-cell attachment and by mediating biofilm-substrate interactions. This sessile mode of bacteria growth has been well studied by microbiologists to prevent the detrimental effects of biofilms in medical and industrial settings. Indeed, biofilms are associated with increased antibiotic resistance in bacterial infections, and they can also cause clogging of pipelines or promote bio-corrosion. However, biofilms also gained interest from biophysics due to their ability to form complex morphological patterns during growth. Recently, the emerging field of engineered living materials investigates biofilm mechanical properties at multiple length scales and leverages the tools of synthetic biology to tune the functions of their constitutive biopolymers. This doctoral thesis aims at clarifying how the morphogenesis of Escherichia coli (E. coli) biofilms is influenced by their growth dynamics and mechanical properties. To address this question, I used methods from cell mechanics and materials science. I first studied how biological activity in biofilms gives rise to non-uniform growth patterns. In a second study, I investigated how E. coli biofilm morphogenesis and its mechanical properties adapt to an environmental stimulus, namely the water content of their substrate. Finally, I estimated how the mechanical properties of E. coli biofilms are altered when the bacteria express different extracellular biopolymers. On nutritive hydrogels, micron-sized E. coli cells can build centimetre-large biofilms. During this process, bacterial proliferation and matrix production introduce mechanical stresses in the biofilm, which release through the formation of macroscopic wrinkles and delaminated buckles. To relate these biological and mechanical phenomena, I used time-lapse fluorescence imaging to track cell and matrix surface densities through the early and late stages of E. coli biofilm growth. Colocalization of high cell and matrix densities at the periphery precede the onset of mechanical instabilities at this annular region. Early growth is detected at this outer annulus, which was analysed by adding fluorescent microspheres to the bacterial inoculum. But only when high rates of matrix production are present in the biofilm centre, does overall biofilm spreading initiate along the solid-air interface. By tracking larger fluorescent particles for a long time, I could distinguish several kinematic stages of E. coli biofilm expansion and observed a transition from non-linear to linear velocity profiles, which precedes the emergence of wrinkles at the biofilm periphery. Decomposing particle velocities to their radial and circumferential components revealed a last kinematic stage, where biofilm movement is mostly directed towards the radial delaminated buckles, which verticalize. The resulting compressive strains computed in these regions were observed to substantially deform the underlying agar substrates. The co-localization of higher cell and matrix densities towards an annular region and the succession of several kinematic stages are thus expected to promote the emergence of mechanical instabilities at the biofilm periphery. These experimental findings are predicted to advance future modelling approaches of biofilm morphogenesis. E. coli biofilm morphogenesis is further anticipated to depend on external stimuli from the environment. To clarify how the water could be used to tune biofilm material properties, we quantified E. coli biofilm growth, wrinkling dynamics and rigidity as a function of the water content of the nutritive substrates. Time-lapse microscopy and computational image analysis revealed that substrates with high water content promote biofilm spreading kinetics, while substrates with low water content promote biofilm wrinkling. The wrinkles observed on biofilm cross-sections appeared more bent on substrates with high water content, while they tended to be more vertical on substrates with low water content. Both wet and dry biomass, accumulated over 4 days of culture, were larger in biofilms cultured on substrates with high water content, despite extra porosity within the matrix layer. Finally, the micro-indentation analysis revealed that substrates with low water content supported the formation of stiffer biofilms. This study shows that E. coli biofilms respond to the water content of their substrate, which might be used for tuning their material properties in view of further applications. Biofilm material properties further depend on the composition and structure of the matrix of extracellular proteins and polysaccharides. In particular, E. coli biofilms were suggested to present tissue-like elasticity due to a dense fibre network consisting of amyloid curli and phosphoethanolamine-modified cellulose. To understand the contribution of these components to the emergent mechanical properties of E. coli biofilms, we performed micro-indentation on biofilms grown from bacteria of several strains. Besides showing higher dry masses, larger spreading diameters and slightly reduced water contents, biofilms expressing both main matrix components also presented high rigidities in the range of several hundred kPa, similar to biofilms containing only curli fibres. In contrast, a lack of amyloid curli fibres provides much higher adhesive energies and more viscoelastic fluid-like material behaviour. Therefore, the combination of amyloid curli and phosphoethanolamine-modified cellulose fibres implies the formation of a composite material whereby the amyloid curli fibres provide rigidity to E. coli biofilms, whereas the phosphoethanolamine-modified cellulose rather acts as a glue. These findings motivate further studies involving purified versions of these protein and polysaccharide components to better understand how their interactions benefit biofilm functions. All three studies depict different aspects of biofilm morphogenesis, which are interrelated. The first work reveals the correlation between non-uniform biological activities and the emergence of mechanical instabilities in the biofilm. The second work acknowledges the adaptive nature of E. coli biofilm morphogenesis and its mechanical properties to an environmental stimulus, namely water. Finally, the last study reveals the complementary role of the individual matrix components in the formation of a stable biofilm material, which not only forms complex morphologies but also functions as a protective shield for the bacteria it contains. Our experimental findings on E. coli biofilm morphogenesis and their mechanical properties can have further implications for fundamental and applied biofilm research fields.}, language = {en} } @article{Csaky2024, author = {Cs{\´a}ky, Moritz}, title = {Habsburg Central Europe}, series = {PaRDeS}, journal = {PaRDeS}, number = {29}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-574-3}, issn = {1614-6492}, doi = {10.25932/publishup-64599}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-645995}, pages = {31 -- 37}, year = {2024}, abstract = {Central Europe is characterized by linguistic and cultural density as well as by endogenous and exogenous cultural influences. These constellations were especially visible in the former Habsburg Empire, where they influenced the formation of individual and collective identities. This led not only to continual crises and conflicts, but also to an equally enormous creative potential as became apparent in the culture of the fin-de-si{\`e}cle.}, language = {en} } @techreport{GraeberSchikora2021, type = {Working Paper}, author = {Graeber, Daniel and Schikora, Felicitas}, title = {Hate is too great a burden to bear}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {31}, issn = {2628-653X}, doi = {10.25932/publishup-50797}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-507972}, pages = {53}, year = {2021}, abstract = {Against a background of increasing violence against non-natives, we estimate the effect of hate crime on refugees' mental health in Germany. For this purpose, we combine two datasets: administrative records on xenophobic crime against refugee shelters by the Federal Criminal Office and the IAB-BAMF-SOEP Survey of Refugees. We apply a regression discontinuity in time design to estimate the effect of interest. Our results indicate that hate crime has a substantial negative effect on several mental health indicators, including the Mental Component Summary score and the Patient Health Questionnaire-4 score. The effects are stronger for refugees with closer geographic proximity to the focal hate crime and refugees with low country-specific human capital. While the estimated effect is only transitory, we argue that negative mental health shocks during the critical period after arrival have important long-term consequences. Keywords: Mental health, hate crime, migration, refugees, human capital.}, language = {en} } @unpublished{DemircanScheelSeehafer1999, author = {Demircan, Ayhan and Scheel, Stefan and Seehafer, Norbert}, title = {Heteroclinic behavior in rotating Rayleigh-B{\´e}nard convection}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14914}, year = {1999}, abstract = {We investigate numerically the appearance of heteroclinic behavior in a three-dimensional, buoyancy-driven fluid layer with stress-free top and bottom boundaries, a square horizontal periodicity with a small aspect ratio, and rotation at low to moderate rates about a vertical axis. The Prandtl number is 6.8. If the rotation is not too slow, the skewed-varicose instability leads from stationary rolls to a stationary mixed-mode solution, which in turn loses stability to a heteroclinic cycle formed by unstable roll states and connections between them. The unstable eigenvectors of these roll states are also of the skewed-varicose or mixed-mode type and in some parameter regions skewed-varicose like shearing oscillations as well as square patterns are involved in the cycle. Always present weak noise leads to irregular horizontal translations of the convection pattern and makes the dynamics chaotic, which is verified by calculating Lyapunov exponents. In the nonrotating case, the primary rolls lose, depending on the aspect ratio, stability to traveling waves or a stationary square pattern. We also study the symmetries of the solutions at the intermittent fixed points in the heteroclinic cycle.}, language = {en} } @article{Luedeling2005, author = {L{\"u}deling, Anke}, title = {Heterogeneity and standardization in data, use, and annotation}, series = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, journal = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, number = {2}, issn = {1866-4725}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-8643}, pages = {43 -- 54}, year = {2005}, abstract = {This paper describes the standardization problems that come up in a diachronic corpus: it has to cope with differing standards with regard to diplomaticity, annotation, and header information. Such highly het-erogeneous texts must be standardized to allow for comparative re-search without (too much) loss of information.}, language = {en} } @book{OPUS4-723, title = {Heterogeneity in focus : creating and using linguistic databases}, editor = {Dipper, Stefanie and G{\"o}tze, Michael and Stede, Manfred}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-48-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-8244}, publisher = {Universit{\"a}t Potsdam}, pages = {145}, year = {2005}, abstract = {The papers in this volume were presented at the workshop Heterogeneity in Linguistic Databases', which took place on July 9, 2004 at the University of Potsdam. The workshop was organized by project D1: Linguistic Database for Information Structure: Annotation and Retrieval', a member project of the SFB 632, a collaborative research center entitled Information Structure: the Linguistic Means for Structuring Utterances, Sentences and Texts'. The workshop brought together both developers and users of linguistic databases from a number of research projects which work on an empirical basis, all of which have to cope with different sorts of heterogeneity: primary linguistic data and annotated information may be heterogeneous, as well as the data structures representing them. The first four papers (by Wagner, Schmidt, L{\"u}deling, and Witt) address aspects of heterogeneous data from the point of view of database developers; the remaining three papers (by Meyer, Smith, and Teich/Fankhauser) focus on data exploitation by the users.}, language = {en} } @techreport{AndresBruttelFriedrichsen2022, type = {Working Paper}, author = {Andres, Maximilian and Bruttel, Lisa Verena and Friedrichsen, Jana}, title = {How communication makes the difference between a cartel and tacit collusion}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, issn = {2628-653X}, doi = {10.25932/publishup-56223}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-562234}, pages = {67}, year = {2022}, abstract = {This paper sheds new light on the role of communication for cartel formation. Using machine learning to evaluate free-form chat communication among firms in a laboratory experiment, we identify typical communication patterns for both explicit cartel formation and indirect attempts to collude tacitly. We document that firms are less likely to communicate explicitly about price fixing and more likely to use indirect messages when sanctioning institutions are present. This effect of sanctions on communication reinforces the direct cartel-deterring effect of sanctions as collusion is more difficult to reach and sustain without an explicit agreement. Indirect messages have no, or even a negative, effect on prices.}, language = {en} } @article{KlempinRehfeldt2023, author = {Klempin, Christiane and Rehfeldt, Daniel}, title = {How to Promote and Measure Reflective Skills in Depth and Breadth of English and Physics Teacher Trainees}, series = {Reflexion in der Lehrkr{\"a}ftebildung: Empirisch - Phasen{\"u}bergreifend - Interdisziplin{\"a}r (Potsdamer Beitr{\"a}ge zur Lehrerbildung und Bildungsforschung ; 4)}, journal = {Reflexion in der Lehrkr{\"a}ftebildung: Empirisch - Phasen{\"u}bergreifend - Interdisziplin{\"a}r (Potsdamer Beitr{\"a}ge zur Lehrerbildung und Bildungsforschung ; 4)}, number = {4}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-566-8}, issn = {2626-3556}, doi = {10.25932/publishup-61938}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-619381}, pages = {115 -- 121}, year = {2023}, abstract = {Supporting reflection in preservice during university-based training is, without doubt, a crucial aspect in attaining teacher professionalism. Therefore, an on-campus seminar designed to relate theory to practice and vice versa - the so-called 'Lehr-Lern-Labor-Seminar (LLLS)' - was implemented over the course of five terms to stimulate reflective skills of English and Physics teacher trainees. Investigations on the effectiveness of three types of the LLLS (no video and two types of video-supported reflections) compared to a parallel group (PG) and a control group (CG) occurred in a mixed methods quasi-experimental study. Reflective skills were elicited with vignettes, relevant covariates with questionnaires. Reflective development was then traced in the dimensions depth and breadth employing a qualitative content analysis. MANCOVA (Multivariate Analysis of Covariance) and regression analyses revealed a substantive increase of reflective depth for English and Physics teacher trainees and breadth development for English LLLS-participants in contrast to both, a PG and a CG, even when controlling for the subjects' individual prerequisites.}, language = {en} } @techreport{EydamDiluiso2022, type = {Working Paper}, author = {Eydam, Ulrich and Diluiso, Francesca}, title = {How to Redistribute the Revenues from Climate Policy?}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {45}, issn = {2628-653X}, doi = {10.25932/publishup-54896}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-548960}, pages = {32}, year = {2022}, abstract = {In light of climate change mitigation efforts, revenues from climate policies are growing, with no consensus yet on how they should be used. Potential efficiency gains from reducing distortionary taxes and the distributional implications of different revenue recycling schemes are currently debated. To account for households heterogeneity and dynamic trade-offs, we study the macroeconomic and welfare performance of different revenue recycling schemes using an Environmental Two-Agent New-Keynesian model, calibrated on the German economy. We find that, in the long run, welfare gains are higher when revenues are used to reduce distortionary taxes on capital, but this comes at the cost of higher inequality: while all households prefer labor income tax reductions to lump-sum transfers, only financially unconstrained households are better off when reducing taxes on capital income. Interestingly, we find that over the transition period relevant to meet short-medium run climate targets, labor income tax cuts are the most efficient and equitable instrument.}, language = {en} }