@phdthesis{Eckert2019, author = {Eckert, Sebastian Oliver}, title = {Accessing active sites of molecular proton dynamics}, doi = {10.25932/publishup-42587}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-425870}, school = {Universit{\"a}t Potsdam}, pages = {xviii, 193}, year = {2019}, abstract = {The unceasing impact of intense sunlight on earth constitutes a continuous source of energy fueling countless natural processes. On a molecular level, the energy contained in the electromagnetic radiation is transferred through photochemical processes into chemical or thermal energy. In the course of such processes, photo-excitations promote molecules into thermally inaccessible excited states. This induces adaptations of their molecular geometry according to the properties of the excited state. Decay processes towards energetically lower lying states in transient molecular geometries result in the formation of excited state relaxation pathways. The photo-chemical relaxation mechanisms depend on the studied system itself, the interactions with its chemical environment and the character of the involved states. This thesis focuses on systems in which photo-induced deprotonation processes occur at specific atomic sites. To detect these excited-state proton dynamics at the affected atoms, a local probe of molecular electronic structure is required. Therefore, site-selective and orbital-specific K-edge soft X-ray spectroscopy techniques are used here to detect photo-induced proton dynamics in gaseous and liquid sample environments. The protonation of nitrogen (N) sites in organic molecules and the oxygen (O) atom in the water molecule are probed locally through transitions between 1s orbitals and the p-derived molecular valence electronic structure. The used techniques are X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). Both yield access to the unoccupied local valence electronic structure, whereas the latter additionally probes occupied states. We apply these probes in optical pump X-ray probe experiments to investigate valence excited-state proton transfer capabilities of aqueous 2-thiopyridone. A characteristic shift of N K-edge X-ray absorption resonances as well as a distinct X-ray emission line are established by us as spectral fingerprints of N deprotonation in the system. We utilize them to identify photo-induced N deprotonation of 2-thiopyridone on femtosecond timescales, in optical pump N K-edge RIXS probe measurements. We further establish excited state proton transfer mechanisms on picosecond and nanosecond timescales along the dominant relaxation pathways of 2-thiopyridone using transient N K-edge XAS. Despite being an excellent probe mechanism for valence excited-state proton dynamics, the K-edge core-excitation itself also disturbs the electronic structure at specific sites of a molecule. The rapid reaction of protons to 1s photo-excitations can yield directional structural distortions within the femtosecond core-excited state lifetime. These directional proton dynamics can change the energetic separation of eigenstates of the system and alter probabilities for radiative decay between them. Both effects yield spectral signatures of the dynamics in RIXS spectra. Using these signatures of RIXS transitions into electronically excited states, we investigate proton dynamics induced by N K-edge excitation in the amino-acid histidine. The minor core-excited state dynamics of histidine in basic and neutral chemical environments allow us to establish XAS and RIXS spectral signatures of different N protonation states at its imidazole N sites. Based on these signatures, we identify an excitation-site-independent N-H dissociation for N K-edge excitation under acidic conditions. Such directional structural deformations, induced by core-excitations, also make proton dynamics in electronic ground states accessible through RIXS transitions into vibrationally excited states. In that context, we interpret high resolution RIXS spectra of the water molecule for three O K-edge resonances based on quantum-chemical wave packet propagation simulations. We show that highly oriented ground state vibrational modes of coupled nuclear motion can be populated through RIXS processes by preparation of core-excited state nuclear wave packets with the same directionality. Based on that, we analytically derive the possibility to extract one-dimensional directional cuts through potential energy surfaces of molecular systems from the corresponding RIXS spectra. We further verify this concept through the extraction of the gas-phase water ground state potential along three coordinates from experimental data in comparison to quantum-chemical simulations of the potential energy surface. This thesis also contains contributions to instrumentation development for investigations of photo-induced molecular dynamics at high brilliance X-ray light sources. We characterize the setup used for the transient valence-excited state XAS measurements of 2-thiopyridone. Therein, a sub-micrometer thin liquid sample environment is established employing in-vacuum flat-jet technology, which enables a transmission experimental geometry. In combination with a MHz-laser system, we achieve a high detection sensitivity for photo-induced X-ray absorption changes. Additionally, we present conceptual improvements for temporal X-ray optical cross-correlation techniques based on transient changes of multilayer optical properties, which are crucial for the realization of femtosecond time-resolved studies at synchrotrons and free-electron lasers.}, language = {en} } @phdthesis{Adam2019, author = {Adam, Maurits}, title = {Action-goal predictions in infancy}, school = {Universit{\"a}t Potsdam}, pages = {137}, year = {2019}, language = {en} } @phdthesis{Paraskevopoulou2019, author = {Paraskevopoulou, Sofia}, title = {Adaptive genetic variation and responses to thermal stress in brachionid rotifers}, pages = {IV, 177}, year = {2019}, abstract = {The importance of cryptic diversity in rotifers is well understood regarding its ecological consequences, but there remains an in depth comprehension of the underlying molecular mechanisms and forces driving speciation. Temperature has been found several times to affect species spatio-temporal distribution and organisms' performance, but we lack information on the mechanisms that provide thermal tolerance to rotifers. High cryptic diversity was found recently in the freshwater rotifer "Brachionus calyciflorus", showing that the complex comprises at least four species: B. calyciflorus sensu stricto (s.s.), B. fernandoi, B. dorcas, and B. elevatus. The temporal succession among species which have been observed in sympatry led to the idea that temperature might play a crucial role in species differentiation. The central aim of this study was to unravel differences in thermal tolerance between species of the former B. calyciflorus species complex by comparing phenotypic and gene expression responses. More specifically, I used the critical maximum temperature as a proxy for inter-species differences in heat-tolerance; this was modeled as a bi-dimensional phenotypic trait taking into consideration the intention and the duration of heat stress. Significant differences on heat-tolerance between species were detected, with B. calyciflorus s.s. being able to tolerate higher temperatures than B. fernandoi. Based on evidence of within species neutral genetic variation, I further examined adaptive genetic variability within two different mtDNA lineages of the heat tolerant B. calyciflorus s.s. to identify SNPs and genes under selection that might reflect their adaptive history. These analyses did not reveal adaptive genetic variation related to heat, however, they show putatively adaptive genetic variation which may reflect local adaptation. Functional enrichment of putatively positively selected genes revealed signals of adaptation in genes related to "lipid metabolism", "xenobiotics biodegradation and metabolism" and "sensory system", comprising candidate genes which can be utilized in studies on local adaptation. An absence of genetically-based differences in thermal adaptation between the two mtDNA lineages, together with our knowledge that B. calyciflorus s.s. can withstand a broad range of temperatures, led to the idea to further investigate shared transcriptomic responses to long-term exposure to high and low temperatures regimes. With this, I identified candidate genes that are involved in the response to temperature imposed stress. Lastly, I used comparative transcriptomics to examine responses to imposed heat-stress in heat-tolerant and heat-sensitive Brachionus species. I found considerably different patterns of gene expression in the two species. Most striking are patterns of expression regarding the heat shock proteins (hsps) between the two species. In the heat-tolerant, B. calyciflorus s.s., significant up-regulation of hsps at low temperatures was indicative of a stress response at the cooler end of the temperature regimes tested here. In contrast, in the heat-sensitive B. fernandoi, hsps generally exhibited up-regulation of these genes along with rising temperatures. Overall, identification of differences in expression of genes suggests suppression of protein biosynthesis to be a mechanism to increase thermal tolerance. Observed patterns in population growth are correlated with the hsp gene expression differences, indicating that this physiological stress response is indeed related to phenotypic life history performance.}, language = {en} } @phdthesis{Petrovic2019, author = {Petrovic, Nevena}, title = {Analysis of the role of Forgetter2 in thermotolerance responses in Arabidopsis thaliana}, school = {Universit{\"a}t Potsdam}, pages = {117}, year = {2019}, language = {en} } @phdthesis{Kowalski2019, author = {Kowalski, Gabriele Joanna}, title = {Animal movement patterns across habitats}, school = {Universit{\"a}t Potsdam}, pages = {143}, year = {2019}, language = {en} } @phdthesis{Wardecki2019, author = {Wardecki, Bartek}, title = {Berlin, Leipziger Straße 3-4}, publisher = {be.bra wissenschaft Verlag}, address = {Berlin}, isbn = {978-3-95410-235-8}, school = {Universit{\"a}t Potsdam}, pages = {382}, year = {2019}, abstract = {In der Leipziger Straße 3-4 in Berlin, in der seit Herbst 2000 der Deutsche Bundesrat residiert, waren seit jeher bedeutende Institutionen angesiedelt. 1904 errichtet f{\"u}r das Preußische Herrenhaus, wurde das Geb{\"a}ude nach dem Ersten Weltkrieg von den Arbeiter- und Soldatenr{\"a}ten genutzt. In der Weimarer Republik teilten sich der Preußische Staatsrat und das Preußische Wohlfahrtsministerium das Haus. Im Nationalsozialismus arbeiteten hier u. a. das Reichskirchenministerium und die Reichsstelle f{\"u}r Raumordnung. Bartek Wardecki bietet eine vollst{\"a}ndige Darstellung der Geschichte dieser ber{\"u}hmten Adresse sowie eine {\"U}bersicht {\"u}ber ann{\"a}hernd 1000 Veranstaltungen, die hier ausgerichtet wurden.}, language = {de} } @phdthesis{Muelling2019, author = {M{\"u}lling, Eric}, title = {Big Data und der digitale Ungehorsam}, publisher = {Springer VS}, address = {Wiesbaden}, isbn = {978-3-658-24158-2}, pages = {XV, 242}, year = {2019}, language = {de} } @phdthesis{Bachsleitner2019, author = {Bachsleitner, Anna}, title = {Bildungsverl{\"a}ufe und soziale Ungleichheit vom Abitur bis zur Promotion}, school = {Universit{\"a}t Potsdam}, pages = {193}, year = {2019}, abstract = {{\"U}berg{\"a}nge im Bildungssystem sind zentrale Stationen f{\"u}r die Generierung von sozialer Ungleichheit. W{\"a}hrend die Bildungswege und die Bedeutung der sozialen Ungleichheit f{\"u}r den Schulbereich umfangreich untersucht wurden, liegen kaum Studien zu den nachschulischen Bildungsverl{\"a}ufen von Hochschulzugangsberechtigten und dem Einfluss der sozialen Herkunft bis zur Aufnahme einer Promotion vor. Daher ist es das Ziel der vorliegenden Arbeit, die Gestaltung nachschulischer Bildungsverl{\"a}ufe zu untersuchen sowie die Bedeutung der sozialen Herkunft vom Abitur bis zur Promotionsaufnahme zu analysieren. Den beiden Forschungsfragen wurde in vier Teilstudien nachgegangen. In Teilstudie 1 wurde die Relevanz von Merkmalen des Bildungsverlaufes f{\"u}r die Promotionsaufnahme untersucht. Der Schwerpunkt der drei folgenden Teilstudien lag auf der Bedeutung der sozialen Herkunft bei Aufnahme einer Promotion beziehungsweise der sozialen Ungleichheit in den relevanten Selektionsstufen des nachschulischen Bildungsverlaufs bis zur Promotionsaufnahme. In Teilstudie 2 wurden diesbez{\"u}glich soziale Herkunftseffekte bei der f{\"u}r eine Promotionsaufnahme bedeutsamen Wahl der Hochschulform untersucht, in Teilstudie 3 die Mechanismen hinter sozialen Herkunftseffekten bei Promotionsaufnahme analysiert und in Teilstudie 4 wurde soziale Ungleichheit bei Studienaufnahme und Promotionsaufnahme vergleichend betrachtet. Als Datengrundlage wurde die L{\"a}ngsschnittstudie BIJU (Bildungsverl{\"a}ufe und psychosoziale Entwicklung im Jugend- und jungen Erwachsenenalter) herangezogen. Die Befunde der Dissertation verweisen auf die Relevanz sozialer Ungleichheiten vom Eintritt in die Hochschule bis zum {\"U}bergang in die Promotion. Auch wenn ein abnehmender Herkunftseffekt vom {\"U}bertritt ins Studium zum {\"U}bertritt in die Promotion vorliegt, sind soziale Herkunftseffekte bei dem sp{\"a}ten Bildungs{\"u}bergang noch sichtbar. Zudem zeigt sich die Bedeutung von Pfadabh{\"a}ngigkeiten in Bildungsverl{\"a}ufen sowie von Leistungsunterschieden f{\"u}r eine Promotionsaufnahme.}, language = {de} } @phdthesis{Jennek2019, author = {Jennek, Julia}, title = {Binnendifferenzierung in der Sekundarstufe I}, school = {Universit{\"a}t Potsdam}, pages = {214}, year = {2019}, language = {de} } @phdthesis{Neumann2019, author = {Neumann, Bettina}, title = {Bioelectrocatalytic activity of surface-confined heme catalysts}, school = {Universit{\"a}t Potsdam}, pages = {116}, year = {2019}, language = {en} }