@phdthesis{Yishai2019,
  author    = {Yishai, Oren},
  title     = {Engineering the reductive glycine pathway in Escherichia coli},
  school      = {Universit{\"a}t Potsdam},
  pages     = {86},
  year      = {2019},
  language  = {en}
}
@book{PresslerRoggan2019,
  author    = {Preßler, Tobias and Roggan, Alfred},
  title     = {Sorbische/Wendische Spuren in der n{\"o}rdlichen Niederlausitz},
  series = {Podstupimske pśinoski k Sorabistice = Potsdamer Beitr{\"a}ge zur Sorabistik},
  journal   = {Podstupimske pśinoski k Sorabistice = Potsdamer Beitr{\"a}ge zur Sorabistik},
  number    = {12},
  editor    = {Norberg, Madlena and Kosta, Peter},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-478-4},
  issn      = {1615-2476},
  doi       = {10.25932/publishup-43693},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436933},
  publisher      = {Universit{\"a}t Potsdam},
  pages     = {185},
  year      = {2019},
  abstract  = {Die Herausgeber der „Potsdamer Beitr{\"a}ge zur Sorabistik/Podstupimske pśinoski k Sorbistice" sind erfreut, nach l{\"a}ngerer Pause einen neuen Band ver{\"o}ffentlichen zu k{\"o}nnen. Gemeinschaftlich legen der Kulturwissenschaftler Tobias Preßler, welcher hier deb{\"u}tiert, und der ausgewiesene Denkmalpfleger i. R. Alfred Roggan, vier Artikel zur niedersorbischen Kulturgeschichte vor. Die Autoren widmen sich der sorbischen Sprache im Norden der Niederlausitz, ihrer ehemaligen Verbreitung und den Umst{\"a}nden ihres Verschwindens. Alle Beitr{\"a}ge n{\"a}hern sich aus unterschiedlicher Perspektive diesem Thema, wobei die Schwerpunkte auf verschiedenen Zeiten und Regionen liegen. Mit Paul Thol wird sich einem Restaurator und K{\"u}nstler zugewandt, dessen Werk und Schaffen in die bewegte 1. H{\"a}lfte des 20. Jahrhunderts f{\"a}llt. Diese Zeit bildet gleichsam den Abschluss einer epochen{\"u}bergreifenden Darstellung zur Politik gegen{\"u}ber den Sorben und ihrer Sprache, welche ein weiterer Artikel skizziert. In den beiden Herzst{\"u}cken des Bandes wird der Leser in die fr{\"u}he Neuzeit entf{\"u}hrt. Es wird ein bisher wenig beachtetes Druckwerk aus dem Jahre 1694 vorgestellt, das seinerzeit bewusst in zw{\"o}lf Sprachen herausgegeben wurde. Als wahres Kleinod der sorbischen Sprachgeschichte findet sich dieses Werk - ein Gedicht - {\"u}berliefert, das in einem nunmehr ausgestorbenen Dialektzweig verfasst ist. Neben dem Gedicht selbst, werden auch dessen bisherige literarische Bearbeitungen sowie der Entstehungshintergrund des Druckes eingehender beschrieben. Der vierte Beitrag widmet sich einer Region, in welcher wohl der gleiche Dialekt wie der des Gedichtes gesprochen wurde. Bis zum Verklingen der Sprache im 18. Jahrhundert war sie hier genauso lebendig wie sie es heute noch in ihrem Kerngebiet ist.},
  language  = {de}
}
@phdthesis{RuizRodriguez2019,
  author    = {Ruiz Rodriguez, Janete Lorena},
  title     = {Osmotic pressure effects on collagen mimetic peptides},
  school      = {Universit{\"a}t Potsdam},
  pages     = {139},
  year      = {2019},
  abstract  = {Collagen is the most abundant protein in mammals. In many tissues, collagen molecules assemble to form a hierarchical structure. In the smallest supramolecular unit, named fibril, each molecule is displaced in the axial direction with respect to its neighbors. This staggering creates a periodic gap and overlap regions, where the gap regions exhibit 20\% less density. These fibril-forming collagens play an essential role in the strength of connective tissues. Despite much effort, directed at understanding collagen function and regulation, the influence of the chemical environment on the local structural and mechanical properties remains poorly understood. Recent studies, aimed at elucidating the effect of osmotic pressure, showed that collagen contracts upon water removal. This observation highlights the importance of water for the stabilization and mechanics of the collagen molecule. Using collagen mimetic peptides (CMPs), which fold into triple helical structures reminiscent of natural collagen, the primary goal of this work was to investigate the effect of the osmotic pressure on specific collagen-mimetic sequences. CMPs were used as the model system as they provide sequence control, which is essential for discriminating local from global structural changes and for relating the observed effects to existing knowledge about the full-length collagen molecule. Of specific interest was the structure of individual collagen triple helices as well as their organization into self-assembled higher order structures. These key structural features were monitored with infrared spectroscopy (IR) and synchrotron X-ray scattering, while varying the osmotic pressure. For controlling the osmotic pressure, CMP powder samples were incubated in air of defined relative humidity, ranging from dry conditions to highly "humid". In addition, to obtain more biologically relevant conditions, the CMPs were measured in ultrapure water and in solutions containing small molecule osmolytes. Using the sequences (Pro-Pro-Gly)10, (Pro-Hyp-Gly)10 and (Hyp-Hyp-Gly)10, it was shown that CMPs with different degrees of proline hydroxylation (Hyp = hydroxyproline) exhibit a sequence-specific response to osmotic pressure. IR spectroscopy revealed that osmotic pressure changes affect the strength of the triple helix stabilizing, interchain hydrogen bond and that the extent of this change depends on the degree of hydroxylation. X-ray scattering experiments further showed that changes in osmotic pressure affect both the molecular length as well as the higher order organization of CMPs. Starting from a pseudo-hexagonal packing in the dry state, all three CMPs showed isotropic swelling when increasing the water content to approximately 1.2 water molecules per amino acid, again to different extents depending on the degree of hydroxylation. When increasing the water content further, this pseudo-hexagonal arrangement breaks down. In the fully hydrated state, each CMP is characterized by its own specific and more complex packing geometry. While these changes in the lateral packing arrangement suggest swelling upon hydration, an overall decrease of the molecular length (i.e. contraction) was observed in the axial direction. Also for this structural feature, a strong dependency on the specific amino acid sequence was found. Interestingly, the observed contraction is the opposite of what has been reported for natural collagen. As (Pro-Pro-Gly)n, (Pro-Hyp-Gly)n and (Hyp-Hyp-Gly)n repeat units are found in collagen with a relatively high abundance, this suggests that other collagen sequence fragments need to respond to hydration in the opposite way to obtain a net elongation of the full-length collagen molecule. To test this hypothesis, sequences predicted to be sensitive to osmotic pressure were considered. One such sequence, consisting of two repeat units (Ala-Arg-Gly-Ser-Asp-Gly), was inserted as a guest into a (Pro-Pro-Gly) host. When compared to the canonical CMP sequences investigated earlier, the lateral helix packing follows a similar trend with increasing hydration; however, the host-guest CMP axially elongates with increasing water content. This behavior is more similar to what has been found for natural collagen and suggests that different sequences do determine the molecular length of collagen sequences differently. Interestingly, the canonical sequences are more abundant in the overlap region while the guest sequence is found in the gap region. This allows to speculate that sequences in the gap and overlap regions possess a specifically fine-tuned local response to osmotic pressure changes. Clearly, more experiments with additional sequences are needed to confirm this. In conclusion, the results obtained in this work indicate a highly sequence specific interaction between collagen and water. Osmotic pressure-induced conformational changes mostly originate from local geometries and bonding patterns and affect both the structure of individual triple helices as well as higher order assemblies. One key remaining question is how these conformational changes affect the local mechanical properties of the collagen molecule. As a first step, the stiffness (persistence length) of full-length collagen was determined using atomic force microscopy. In the future, experimental strategies need to be developed that allow for investigating the mechanical properties of specific collagen sequences, e.g. performing single-molecule force spectroscopy of CMPs.},
  language  = {en}
}
@article{PornsawadSapsakulBoeckmann2019,
  author    = {Pornsawad, Pornsarp and Sapsakul, Nantawan and B{\"o}ckmann, Christine},
  title     = {A modified asymptotical regularization of nonlinear ill-posed problems},
  series = {Mathematics},
  volume    = {7},
  journal   = {Mathematics},
  edition   = {5},
  publisher = {MDPI},
  address   = {Basel, Schweiz},
  issn      = {2227-7390},
  doi       = {10.3390/math7050419},
  pages     = {19},
  year      = {2019},
  abstract  = {In this paper, we investigate the continuous version of modified iterative Runge-Kutta-type methods for nonlinear inverse ill-posed problems proposed in a previous work. The convergence analysis is proved under the tangential cone condition, a modified discrepancy principle, i.e., the stopping time T is a solution of ∥𝐹(𝑥𝛿(𝑇))-𝑦𝛿∥=𝜏𝛿+ for some 𝛿+>𝛿, and an appropriate source condition. We yield the optimal rate of convergence.},
  language  = {en}
}