TY - GEN A1 - Werner, John S. A1 - Cicerone, Carola M. A1 - Kliegl, Reinhold A1 - DellaRosa, Denise T1 - Spectral efficiency of blackness induction N2 - The spectral efficiency of blackness induction was measured in three normal trichromatic observers and in one deuteranomalous observer. The psychophysical task was to adjust the radiance of a monochromatic 60–120′ annulus until a 45′ central broadband field just turned black and its contour became indiscriminable from a dark surrounding gap that separated it from the annulus. The reciprocal of the radiance required to induce blackness with annulus wavelengths between 420 and 680 nm was used to define a spectral-efficiency function for the blackness component of the achromatic process. For each observer, the shape of this blackness-sensitivity function agreed with the spectral-efficiency function based on heterochromatic flicker photometry when measured with the same 60–120′ annulus. Both of these functions matched the Commission Internationale de l'Eclairage Vλ function except at short wavelengths. Ancillary measurements showed that the latter difference in sensitivity can be ascribed to nonuniformities of preretinal absorption, since the annular field excluded the central 60′ of the fovea. Thus our evidence indicates that, at least to a good first approximation, induced blackness is inversely related to the spectral-luminosity function. These findings are consistent with a model that separates the achromatic and the chromatic pathways. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 040 Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16897 ER - TY - THES A1 - Ketzer, Laura T1 - The impact of stellar activity evolution on atmospheric mass loss of young exoplanets T1 - Der Einfluss der stellaren Aktivitätsentwicklung auf den atmosphärischen Massenverlust von jungen Exoplaneten N2 - The increasing number of known exoplanets raises questions about their demographics and the mechanisms that shape planets into how we observe them today. Young planets in close-in orbits are exposed to harsh environments due to the host star being magnetically highly active, which results in high X-ray and extreme UV fluxes impinging on the planet. Prolonged exposure to this intense photoionizing radiation can cause planetary atmospheres to heat up, expand and escape into space via a hydrodynamic escape process known as photoevaporation. For super-Earth and sub-Neptune-type planets, this can even lead to the complete erosion of their primordial gaseous atmospheres. A factor of interest for this particular mass-loss process is the activity evolution of the host star. Stellar rotation, which drives the dynamo and with it the magnetic activity of a star, changes significantly over the stellar lifetime. This strongly affects the amount of high-energy radiation received by a planet as stars age. At a young age, planets still host warm and extended envelopes, making them particularly susceptible to atmospheric evaporation. Especially in the first gigayear, when X-ray and UV levels can be 100 - 10,000 times higher than for the present-day sun, the characteristics of the host star and the detailed evolution of its high-energy emission are of importance. In this thesis, I study the impact of stellar activity evolution on the high-energy-induced atmospheric mass loss of young exoplanets. The PLATYPOS code was developed as part of this thesis to calculate photoevaporative mass-loss rates over time. The code, which couples parameterized planetary mass-radius relations with an analytical hydrodynamic escape model, was used, together with Chandra and eROSITA X-ray observations, to investigate the future mass loss of the two young multiplanet systems V1298 Tau and K2-198. Further, in a numerical ensemble study, the effect of a realistic spread of activity tracks on the small-planet radius gap was investigated for the first time. The works in this thesis show that for individual systems, in particular if planetary masses are unconstrained, the difference between a young host star following a low-activity track vs. a high-activity one can have major implications: the exact shape of the activity evolution can determine whether a planet can hold on to some of its atmosphere, or completely loses its envelope, leaving only the bare rocky core behind. For an ensemble of simulated planets, an observationally-motivated distribution of activity tracks does not substantially change the final radius distribution at ages of several gigayears. My simulations indicate that the overall shape and slope of the resulting small-planet radius gap is not significantly affected by the spread in stellar activity tracks. However, it can account for a certain scattering or fuzziness observed in and around the radius gap of the observed exoplanet population. N2 - Die steigende Anzahl bekannter Exoplaneten wirft Fragen zu ihrer Demografie und den Mechanismen auf, die Planeten in ihre heutige beobachtete Form bringen. Junge Planeten, die sehr nah um ihren Wirtsstern kreisen, sind extremen Umgebungen ausgesetzt, da der Stern eine hohe magnetische Aktivität aufweist. Das führt wiederum dazu, dass der Planet einer enormen Röntgen- und Extrem-UV-Strahlung ausgesetzt ist. Ist der Planet über einen längeren Zeitraum dieser intensiven photoionisierenden Strahlung ausgesetzt, kann dies dazu führen, dass Planetenatmosphären sich aufheizen, ausdehnen und durch einen hydrodynamischen Entweichungsprozess namens Photoevaporation ins All entweichen, sozusagen verdampfen. Bei Planeten, in der Größenordnung von Super-Erden und Sub-Neptunen, kann dies sogar zur vollständigen Erosion ihrer Ur-Atmosphären führen. Ein interessanter Faktor, der für diesen Massenverlustprozess eine Rolle spielt, ist die Aktivitätsentwicklung des Wirtssterns. Die Rotation eines Sterns, die den Dynamo und damit die magnetische Aktivität antreibt, ändert sich im Laufe der Lebensdauer eines Sterns erheblich. Dies hat einen starken Einfluss auf die Menge der hochenergetischen Strahlung, den ein Planet mit zunehmendem Alter des Sterns empfängt. In jungen Jahren besitzen Planeten noch warme und ausgedehnte Hüllen, was sie besonders anfällig für atmosphärische Verdunstung macht. Insbesondere in den ersten Gigajahren, wenn die Röntgen- und UV-Strahlung 100 - 10,000 Mal höher sein kann als bei der heutigen Sonne, sind die Eigenschaften des Wirtssterns und die detaillierte Entwicklung seiner hochenergetischen Emission von Bedeutung. In dieser Arbeit untersuche ich die Auswirkungen der Entwicklung der stellaren Aktivität auf den durch hochenergetische Strahlung verursachten atmosphärischen Massenverlust junger Exoplaneten. Der PLATYPOS-Code wurde im Rahmen dieser Arbeit entwickelt, um die photoevaporativen Massenverlustraten für verschiedene stellare Alter zu berechnen. Der Code verknüpft parametrisierte Planetenmasse-Radius-Beziehungen mit einem analytischen Modell für den hydrodynamischen Massenverlust. Er wurde zusammen mit Chandra- und eROSITA-Röntgenbeobachtungen dazu verwendet, den zukünftigen Massenverlust der beiden jungen Mehrplanetensysteme V1298 Tau und K2-198 zu untersuchen. Darüber hinaus wurde in einer numerischen Ensemblestudie erstmals der Effekt einer realistischen Verteilung von stellaren Aktivitäts-Tracks auf das sogenannte Radius-Tal bei kleinen Planeten untersucht. Die Arbeiten in dieser Dissertation zeigen, dass für einzelne Systeme, insbesondere wenn die Planetenmassen unbestimmt sind, der Unterschied zwischen einem jungen Wirtsstern, der einem Track mit niedriger Aktivität gegenüber einem solchen mit hoher Aktivität folgt, gravierende Auswirkungen haben kann: Die genaue Form der Aktivitätsentwicklung kann darüber entscheiden, ob ein Planet einen Teil seiner Atmosphäre behält oder seine Hülle vollständig verliert und nur den nackten Gesteinskern behält. Für ein Ensemble von simulierten Planeten ändert eine durch Beobachtungen motivierte Verteilung von Aktivitäts-Tracks die endgültige Radiusverteilung der Planeten nach mehreren Gigajahren nicht wesentlich. Meine Simulationen deuten darauf hin, dass die Form und Steigung des sich ergebenden Radius-Tals bei Kleinplaneten nicht wesentlich von der Streuung der stellaren Aktivitäts-Tracks beeinflusst wird. Eine gewisse Streuung oder Unschärfe im Radius-Tal der beobachteten Exoplanetenpopulation kann damit allerdings durchaus erklärt werden. KW - Exoplaneten KW - star-planet interaction KW - stellar physics KW - exoplanets KW - exoplanet atmospheres KW - Sternphysik KW - Stern-Planeten-Wechselwirkung KW - Exoplanetenatmosphären Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-626819 ER - TY - JOUR A1 - Corbett, Tim A1 - Siegel, Björn A1 - Thulin, Mirjam T1 - Towards Pluricultural and Connected Histories BT - Intersections between Jewish and Habsburg Studies JF - PaRDeS Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-645988 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 15 EP - 27 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Hödl, Klaus T1 - Blurring the Boundaries of Jewishness BT - Exploring Jewish-non-Jewish Neighborliness and Similarity JF - PaRDeS N2 - In this essay I argue that while research in Jewish studies over the last several decades has done much to erode the historical narrative of Jewish/non-Jewish separation and detachment, it has also raised various questions pertaining to the outcome of Jewish/non-Jewish interactions and coexistence as well as the contours of Jewish difference. I contend that employing the concepts of conviviality, ethnic/religious/national indifference, and similarity will greatly facilitate answering these questions. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-646009 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 39 EP - 50 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Csáky, Moritz T1 - Habsburg Central Europe BT - Culturally Heterogeneous and Polysemous Regions JF - PaRDeS N2 - 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-siècle. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-645995 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 31 EP - 37 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Gebser, Martin A1 - Hinrichs, Henrik A1 - Schaub, Torsten A1 - Thiele, Sven T1 - xpanda: a (simple) preprocessor for adding multi-valued propositions to ASP N2 - We introduce a simple approach extending the input language of Answer Set Programming (ASP) systems by multi-valued propositions. Our approach is implemented as a (prototypical) preprocessor translating logic programs with multi-valued propositions into logic programs with Boolean propositions only. Our translation is modular and heavily benefits from the expressive input language of ASP. The resulting approach, along with its implementation, allows for solving interesting constraint satisfaction problems in ASP, showing a good performance. Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41466 ER - TY - JOUR A1 - Kauders, Anthony D. T1 - Kateřina Čapková/Hillel J. Kieval (eds.), Prague and Beyond. Jews in the Bohemian Lands (Philadelphia, PA: University of Pennsylvania Press 2021), 384 pp. JF - PaRDeS Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650417 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 160 EP - 163 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Jánošíková, Magdaléna T1 - Jason Sion Mokhtarian, Medicine in the Talmud: Natural and Supernatural Therapies between Magic and Science (Berkeley, CA: University of California Press, 2022), 260 pp. JF - PaRDeS Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650392 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 154 EP - 157 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Kasper-Marienberg, Verena T1 - Imperial Transition and Early Modern Jewish Continuities BT - The Case of Bohemian Jewry JF - PaRDeS N2 - This article brings two seemingly disconnected historiographic models of periodization into conversation: Habsburg studies and Habsburg Jewish studies. It argues for an expansion of the temporal frameworks of both fields to highlight historical continuities connecting the Holy Roman and Habsburg Empire at least from a structural perspective. These historical continuums are a useful analytical lens when applied to marginalized groups, like early modern Jews, in tandem with a central group of contemporary powerholders, such as the Habsburg nobility. Using Bohemia as a case study, this essay juxtaposes questions of transregional transfer of cultural, economic, and social capital with the challenges of Jewish marginalization and discrimination to highlight the changing yet interconnected imperial landscapes. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650224 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 53 EP - 66 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Berkovich, Ilya T1 - Jewish Mercenaries in Habsburg Service BT - Soldiers of the Freikorps Grün Loudon (1796–98) JF - PaRDeS N2 - This article aims to demonstrate the exceptional potential of Habsburg military records for the study of Jewish history during Europe’s Age of Revolution. We begin with the random discovery of six Jewish veterans of Freikorps Grün Loudon – a unit of mercenary freebooters – which fought for the Habsburgs during the first war against the French Republic (1792 – 97). A careful re-reading of the available archival evidence reveals that these men were the survivors of a much larger group numbering at least two dozen Jewish soldiers. While Jewish conscripts had been drafted into the Habsburg army since 1788, the fact that Jews could also serve – even volunteer – as professional soldiers in that period is completely new to us. When considered together, the personal circumstances and service experiences of the Jewish soldiers of Freikorps Grün Loudon enable us to make several observations about their motivation as well as their position vis-à-vis their non-Jewish comrades. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650239 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 69 EP - 79 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Czakai, Johannes T1 - Between Legibility, Emancipation, and Markers of “Otherness” BT - The Habsburg Empire and the Names of Jews JF - PaRDeS N2 - The article analyzes the interdependences between the history of the Habsburg Empire and the names of its Jewish inhabitants. Until today, these names tell stories about this close relationship and they are an everlasting symbol of this era. By focusing on names, this paper shows how state policies towards Jews shifted over time, and how the perspective on names and name regulations can be a tool to connect and investigate both Habsburg and Jewish studies. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650249 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 81 EP - 89 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Stechauner, Martin T1 - “Domestic Foreigners” BT - The Trans-Imperial Loyalties of Sephardic Jews in Vienna JF - PaRDeS N2 - This paper examines the relationship between the Sephardic Jewish community of Vienna and the Ottoman and Habsburg Empires in the latter half of the 19th century. The community’s legal status was transformed following the emancipation of Austrian Jews, but very few first-hand accounts of these changes exist today. The primary sources analyzed in this paper are Judezmo-language newspapers published in Vienna at that time. The paper emphasizes the historical and political contexts surrounding these sources, particularly the community’s close ties to the Ottoman and Habsburg regimes. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650260 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 103 EP - 112 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Dodou, Lida-Maria T1 - “Austrian,” “Jewish,” “Salonican” BT - The Multiple Aspects of Belonging of Salonican Jews in the Fin-de-Siècle Habsburg Empire JF - PaRDeS N2 - Even though Salonican Jews are not typically associated with the Habsburg Empire, some of them, nonetheless, lived there. This paper aims to examine the formation of these Salonican Jews’ (self-)identification by studying their social interactions with the local Viennese population such as the Viennese Sephardi or the Greek-Orthodox communities. The change of the milieu within which they found themselves subsequently impacted their self-perception. Thus, the issue of the surrounding environment and their relations with other groups became central to their self-understanding, as will be demonstrated. By examining different aspects, like migration patterns, financial decisions and family ties, one can understand how their intersection influenced Salonica Jews’ self-identification, which, at the same time, shaped and was shaped by the surrounding milieu. Within this framework, these people perceived themselves and were perceived as Salonican, Sephardi, Jewish, and as subjects of the Emperor. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650271 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 115 EP - 123 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Maślak-Maciejewska, Alicja T1 - Shared Spaces BT - Jews in Public Schools in Galicia JF - PaRDeS N2 - Galicia was home to the largest Jewish population of the Cisleithanian part of the Habsburg Empire. After the Josephinian “German-Jewish schools” had closed already in 1806, educational patterns differed from those in Moravia and Bohemia, where Jewish children received a secular education in a more consistent “Jewish” space. In Galicia in the constitutional era (post-1867), however, with mandatory education enforced, public schools became a shared space in which Jews and (Catholic) Christians functioned together. In Galicia, most Jewish children received public education but usually constituted a religious minority in the student body. The article analyzes how the school space, calendar, and routines were adjusted to accommodate the multi-religious character of the student body. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650253 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 91 EP - 100 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Piskačová, Zora T1 - Agnieszka Wierzcholska, Nur Erinnerungen und Steine sind geblieben. Leben und Sterben einer polnisch-jüdischen Stadt: Tarnów 1918 – 1945 (Paderborn: Brill-Schöningh Verlag, 2022), 665 pp. JF - PaRDeS Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650538 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 163 EP - 167 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Nasr, Omar T. A1 - Corbett, Tim T1 - Diversifying Modern Austrian History BT - Exploring Parallels and Intersections between Jewish and Muslim Histories in Austria JF - PaRDeS N2 - Jews and Muslims have lived in the territory of modern-day Austria for centuries untold, yet often continue to be construed as the essential “other.” This essay explores a selection of sometimes divergent, sometimes convergent historical experiences amongst these two broad population groups, focusing specifically on demographic diversity, community-building, discrimination and persecution, and the post-war situation. The ultimate aim is to illuminate paradigmatically through the Austrian case study the complex multicultural mosaic of historical Central Europe, the understanding of which, so our contention, sheds a critical light on the often divisive present-day debates concerning immigration and diversity in Austria and Central Europe more broadly. It furthermore opens up a hitherto understudied field of historical research, namely the entangled history of Jews and Muslims in modern Europe. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650290 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 137 EP - 147 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP ED - Hamann, Wolf-Rainer ED - Feldmeier, Achim ED - Oskinova, Lidia M. T1 - Clumping in hot-star winds : proceedings of an international workshop held in Potsdam, Germany, 18. - 22. June 2007 N2 - Stellar winds play an important role for the evolution of massive stars and their cosmic environment. Multiple lines of evidence, coming from spectroscopy, polarimetry, variability, stellar ejecta, and hydrodynamic modeling, suggest that stellar winds are non-stationary and inhomogeneous. This is referred to as 'wind clumping'. The urgent need to understand this phenomenon is boosted by its far-reaching implications. Most importantly, all techniques to derive empirical mass-loss rates are more or less corrupted by wind clumping. Consequently, mass-loss rates are extremely uncertain. Within their range of uncertainty, completely different scenarios for the evolution of massive stars are obtained. Settling these questions for Galactic OB, LBV and Wolf-Rayet stars is prerequisite to understanding stellar clusters and galaxies, or predicting the properties of first-generation stars. In order to develop a consistent picture and understanding of clumped stellar winds, an international workshop on 'Clumping in Hot Star Winds' was held in Potsdam, Germany, from 18. - 22. June 2007. About 60 participants, comprising almost all leading experts in the field, gathered for one week of extensive exchange and discussion. The Scientific Organizing Committee (SOC) included John Brown (Glasgow), Joseph Cassinelli (Madison), Paul Crowther (Sheffield), Alex Fullerton (Baltimore), Wolf-Rainer Hamann (Potsdam, chair), Anthony Moffat (Montreal), Stan Owocki (Newark), and Joachim Puls (Munich). These proceedings contain the invited and contributed talks presented at the workshop, and document the extensive discussions. KW - Sternwinde KW - Massenverlust KW - Strahlungstransport KW - hydrodynamische Modellierung KW - massereiche Sterne KW - stellar winds KW - mass loss KW - radiative transfer KW - hydrodynamic modeling KW - massive stars Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13981 SN - 978-3-940793-33-1 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Martin, Johannes T1 - Synthesis of protein-polymer conjugates and block copolymers via sortase-mediated ligation N2 - In den vergangenen Jahrzehnten haben therapeutische Proteine in der pharmazeutischen Industrie mehr und mehr an Bedeutung gewonnen. Werden Proteine nichtmenschlichen Ursprungs verwendet, kann es jedoch zu einer Immunreaktion kommen, sodass das Protein sehr schnell aus dem Körper ausgeschieden oder abgebaut wird. Um die Zirkulationszeit im Blut signifikant zu verlängern, werden die Proteine mit synthetischen Polymeren modifiziert (Protein-Polymer-Konjugate). Die Proteine aller heute auf dem Markt erhältlichen Medikamente dieser Art tragen eine oder mehrere Polymerketten aus Poly(ethylenglycol) (PEG). Ein Nachteil der PEGylierung ist, dass viele Patienten bei regelmäßiger Einnahme dieser Medikamente Antikörper gegen PEG entwickeln, die den effizienzsteigernden Effekt der PEGylierung wieder aufheben. Ein weiterer Nachteil der PEGylierung ist die oftmals deutlich verringerte Aktivität der Konjugate im Vergleich zum nativen Protein. Der Grund dafür ist die Herstellungsmethode der Konjugate, bei der meist die primären Amine der Lysin-Seitenketten und der N-Terminus des Proteins genutzt werden. Da die meisten Proteine mehrere gut zugängliche Lysine aufweisen, werden oft unterschiedliche und teilweise mehrere Lysine mit PEG funktionalisiert, was zu einer Mischung an Regioisomeren führt. Je nach Position der PEG-Kette kann das aktive Zentrum abgeschirmt oder die 3D-Struktur des Proteins verändert werden, was zu einem teilweise drastischen Aktivitätsabfall führt. In dieser Arbeit wurde eine neuartige Methode zur Ligation von Makromolekülen untersucht. Die Verwendung eines Enzyms als Katalysator zur Verbindung zweier Makromoleküle ist bisher wenig untersucht und ineffizient. Als Enzym wurde Sortase A ausgewählt, eine gut untersuchte Ligase aus der Familie der Transpeptidasen, welche die Ligation zweier Peptide katalysieren kann. Ein Nachteil dieser Sortase-vermittelten Ligation ist, dass es sich um eine Gleichgewichtsreaktion handelt, wodurch hohe Ausbeuten schwierig zu erreichen sind. Im Rahmen dieser Dissertation wurden zwei zuvor entwickelte Methoden zur Verschiebung des Gleichgewichts ohne Einsatz eines großen Überschusses von einem Edukt für Makromoleküle überprüft. Zur Durchführung der Sortase-vermittelten Ligation werden zwei komplementäre Peptidsequenzen verwendet, die Erkennungssequenz und das Nukleophil. Um eine systematische Untersuchung durchführen zu können, wurden alle nötigen Bausteine (Protein-Erkennungssequenz zur Reaktion mit Nukleophil-Polymer und Polymer-Erkennungssequenz mit Nukleophil-Protein) hergestellt. Als Polymerisationstechnik wurde die radikalische Polymerisation mit reversibler Deaktivierung (im Detail, Atom Transfer Radical Polymerization, ATRP und Reversible Addition-Fragmentation Chain Transfer, RAFT polymerization) gewählt, um eine enge Molmassenverteilung zu erreichen. Die Herstellung der Bausteine begann mit der Synthese der Peptide via automatisierter Festphasen-Peptidsynthese, um eine einfache Änderung der Peptidsequenz zu gewährleisten und um eine Modifizierung der Polymerkette nach der Polymerisation zu umgehen. Um die benötigte unterschiedliche Funktionalität der zwei Peptidsequenzen (freier C-Terminus bei der Erkennungssequenz bzw. freier N-Terminus bei dem Nukleophil) zu erreichen, wurden verschiedene Linker zwischen Harz und Peptid verwendet. Danach wurde der Kettenüberträger (chain transfer agent, CTA) zur Kontrolle der Polymerisation mit dem auf dem Harz befindlichen Peptid gekoppelt. Die für die anschließende Polymerisation verwendeten Monomere basierten auf Acrylamiden und Acrylaten und wurden anhand ihrer Eignung als Alternativen zu PEG ausgewählt. Es wurde eine kürzlich entwickelte Technik basierend auf der RAFT-Polymerisation (xanthate-supported photo-iniferter RAFT, XPI-RAFT) verwendet um eine Reihe an Peptid-Polymeren mit unterschiedlichen Molekulargewichten und engen Molekulargewichtsverteilungen herzustellen. Nach Entfernung der Schutzgruppen der Peptid-Seitenketten wurden die Peptid-Polymere zunächst genutzt, um mittels Sortase-vermittelter Ligation zwei Polymerketten zu einem Blockcopolymer zu verbinden. Unter Verwendung von Ni2+-Ionen in Kombination mit einer Verlängerung der Erkennungssequenz um ein Histidin zur Unterdrückung der Rückreaktion konnte ein maximaler Umsatz von 70 % erreicht werden. Dabei zeigte sich ein oberes Limit von durchschnittlich 100 Wiederholungseinheiten; die Ligation von längeren Polymeren war nicht erfolgreich. Danach wurden ein Modellprotein und ein Nanobody mit vielversprechenden medizinischen Eigenschaften mit den für die enzymkatalysierte Ligation benötigten Peptidsequenzen für die Kopplung mit den zuvor hergestellten Peptid-Polymeren verwendet. Dabei konnte bei Verwendung des Modellproteins keine Bildung von Protein-Polymer-Konjugaten beobachtet werden. Der Nanobody konnte dagegen C-terminal mit einem Polymer funktionalisiert werden. Dabei wurde eine ähnliche Limitierung in der Polymer-Kettenlänge beobachtet wie zuvor. Die auf Ni-Ionen basierte Strategie zur Gleichgewichtsverschiebung hatte hier keinen ausschlaggebenden Effekt, während die Verwendung von einem Überschuss an Polymer zur vollständigen Umsetzung des Edukt-Nanobody führte. Die erhaltenen Daten aus diesem Projekt bilden eine gute Basis für weitere Forschung in dem vielversprechenden Feld der enzymkatalysierten Herstellung von Protein-Polymer-Konjugaten und Blockcopolymeren. Langfristig könnte diese Herangehensweise eine vielseitig einsetzbare Herstellungsmethode von ortsspezifischen therapeutischen Protein-Polymer Konjugaten darstellen, welche sowohl eine hohe Aktivität als auch eine lange Zirkulationszeit im Blut aufweisen. N2 - During the last decades, therapeutical proteins have risen to great significance in the pharmaceutical industry. As non-human proteins that are introduced into the human body cause a distinct immune system reaction that triggers their rapid clearance, most newly approved protein pharmaceuticals are shielded by modification with synthetic polymers to significantly improve their blood circulation time. All such clinically approved protein-polymer conjugates contain polyethylene glycol (PEG) and its conjugation is denoted as PEGylation. However, many patients develop anti-PEG antibodies which cause a rapid clearance of PEGylated molecules upon repeated administration. Therefore, the search for alternative polymers that can replace PEG in therapeutic applications has become important. In addition, although the blood circulation time is significantly prolonged, the therapeutic activity of some conjugates is decreased compared to the unmodified protein. The reason is that these conjugates are formed by the traditional conjugation method that addresses the protein's lysine side chains. As proteins have many solvent exposed lysines, this results in a somewhat uncontrolled attachment of polymer chains, leading to a mixture of regioisomers, with some of them eventually affecting the therapeutic performance. This thesis investigates a novel method for ligating macromolecules in a site-specific manner, using enzymatic catalysis. Sortase A is used as the enzyme: It is a well-studied transpeptidase which is able to catalyze the intermolecular ligation of two peptides. This process is commonly referred to as sortase-mediated ligation (SML). SML constitutes an equilibrium reaction, which limits product yield. Two previously reported methods to overcome this major limitation were tested with polymers without using an excessive amount of one reactant. Specific C- or N-terminal peptide sequences (recognition sequence and nucleophile) as part of the protein are required for SML. The complementary peptide was located at the polymer chain end. Grafting-to was used to avoid damaging the protein during polymerization. To be able to investigate all possible combinations (protein-recognition sequence and nucleophile-protein as well as polymer-recognition sequence and nucleophile-polymer) all necessary building blocks were synthesized. Polymerization via reversible deactivation radical polymerization (RDRP) was used to achieve a narrow molecular weight distribution of the polymers, which is required for therapeutic use. The synthesis of the polymeric building blocks was started by synthesizing the peptide via automated solid-phase peptide synthesis (SPPS) to avoid post-polymerization attachment and to enable easy adaptation of changes in the peptide sequence. To account for the different functionalities (free N- or C-terminus) required for SML, different linker molecules between resin and peptide were used. To facilitate purification, the chain transfer agent (CTA) for reversible addition-fragmentation chain-transfer (RAFT) polymerization was coupled to the resin-immobilized recognition sequence peptide. The acrylamide and acrylate-based monomers used in this thesis were chosen for their potential to replace PEG. Following that, surface-initiated (SI) ATRP and RAFT polymerization were attempted, but failed. As a result, the newly developed method of xanthate-supported photo-iniferter (XPI) RAFT polymerization in solution was used successfully to obtain a library of various peptide-polymer conjugates with different chain lengths and narrow molar mass distributions. After peptide side chain deprotection, these constructs were used first to ligate two polymers via SML, which was successful but revealed a limit in polymer chain length (max. 100 repeat units). When utilizing equimolar amounts of reactants, the use of Ni2+ ions in combination with a histidine after the recognition sequence to remove the cleaved peptide from the equilibrium maximized product formation with conversions of up to 70 %. Finally, a model protein and a nanobody with promising properties for therapeutical use were biotechnologically modified to contain the peptide sequences required for SML. Using the model protein for C- or N-terminal SML with various polymers did not result in protein-polymer conjugates. The reason is most likely the lack of accessibility of the protein termini to the enzyme. Using the nanobody for C-terminal SML, on the other hand, was successful. However, a similar polymer chain length limit was observed as in polymer-polymer SML. Furthermore, in case of the synthesis of protein-polymer conjugates, it was more effective to shift the SML equilibrium by using an excess of polymer than by employing the Ni2+ ion strategy. Overall, the experimental data from this work provides a good foundation for future research in this promising field; however, more research is required to fully understand the potential and limitations of using SML for protein-polymer synthesis. In future, the method explored in this dissertation could prove to be a very versatile pathway to obtain therapeutic protein-polymer conjugates that exhibit high activities and long blood circulation times. KW - biohybrid molecules KW - sortaseA KW - polymerization KW - RAFT KW - ATRP KW - peptide synthesis KW - enzymatic conjugation KW - sortagging Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-645669 ER - TY - THES A1 - Videla, Santiago T1 - Reasoning on the response of logical signaling networks with answer set programming T1 - Modellierung Logischer Signalnetzwerke mittels Antwortmengenprogrammierung N2 - Deciphering the functioning of biological networks is one of the central tasks in systems biology. In particular, signal transduction networks are crucial for the understanding of the cellular response to external and internal perturbations. Importantly, in order to cope with the complexity of these networks, mathematical and computational modeling is required. We propose a computational modeling framework in order to achieve more robust discoveries in the context of logical signaling networks. More precisely, we focus on modeling the response of logical signaling networks by means of automated reasoning using Answer Set Programming (ASP). ASP provides a declarative language for modeling various knowledge representation and reasoning problems. Moreover, available ASP solvers provide several reasoning modes for assessing the multitude of answer sets. Therefore, leveraging its rich modeling language and its highly efficient solving capacities, we use ASP to address three challenging problems in the context of logical signaling networks: learning of (Boolean) logical networks, experimental design, and identification of intervention strategies. Overall, the contribution of this thesis is three-fold. Firstly, we introduce a mathematical framework for characterizing and reasoning on the response of logical signaling networks. Secondly, we contribute to a growing list of successful applications of ASP in systems biology. Thirdly, we present a software providing a complete pipeline for automated reasoning on the response of logical signaling networks. N2 - Deciphering the functioning of biological networks is one of the central tasks in systems biology. In particular, signal transduction networks are crucial for the understanding of the cellular response to external and internal perturbations. Importantly, in order to cope with the complexity of these networks, mathematical and computational modeling is required. We propose a computational modeling framework in order to achieve more robust discoveries in the context of logical signaling networks. More precisely, we focus on modeling the response of logical signaling networks by means of automated reasoning using Answer Set Programming (ASP). ASP provides a declarative language for modeling various knowledge representation and reasoning problems. Moreover, available ASP solvers provide several reasoning modes for assessing the multitude of answer sets. Therefore, leveraging its rich modeling language and its highly efficient solving capacities, we use ASP to address three challenging problems in the context of logical signaling networks: learning of (Boolean) logical networks, experimental design, and identification of intervention strategies. Overall, the contribution of this thesis is three-fold. Firstly, we introduce a mathematical framework for characterizing and reasoning on the response of logical signaling networks. Secondly, we contribute to a growing list of successful applications of ASP in systems biology. Thirdly, we present a software providing a complete pipeline for automated reasoning on the response of logical signaling networks. KW - Systembiologie KW - logische Signalnetzwerke KW - Antwortmengenprogrammierung KW - systems biology KW - logical signaling networks KW - answer set programming Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-71890 ER - TY - JOUR A1 - Heimann-Jelinek, Felicitas T1 - What was “Jewish” about the Old Jewish Museum of Vienna? JF - PaRDeS N2 - The Jewish museums established in the fin-de-siècle Habsburg Empire postulated the unity of “the Jewish people,” with custodians constructing an “us” (Jews) in distinction to the “other” (non-Jews). In the difference-oriented frenzy of the time, Jewish identity was predominantly presented as Central European, enlightened, not overly religious, and middle-class. Then, when the Viennese Jewish Museum opened its doors in 1895, the painters Isidor Kaufmann and David Kohn created an installation called “Die Gute Stube” (The Parlor). This exhibit housed books, furniture, as well as decorative and ritual objects of the kind that were thought to be found in typical Eastern European Jewish households. However, as this article argues, this attempted visualization of the essence of Judaism and the range of Jewish life worlds promoted a paradigmatic stereotype with which Jewish museums would have to struggle for decades to come. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-650283 SN - 978-3-86956-574-3 SN - 1614-6492 SN - 1862-7684 IS - 29 SP - 125 EP - 134 PB - Universitätsverlag Potsdam CY - Potsdam ER -