@phdthesis{Guidi2017,
  author    = {Guidi, Giovanni},
  title     = {Connecting simulations and observations in galaxy formation studies},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-396876},
  school      = {Universit{\"a}t Potsdam},
  pages     = {141},
  year      = {2017},
  abstract  = {Observational and computational extragalactic astrophysics are two fields of research that study a similar subject from different perspectives. Observational extragalactic astrophysics aims, by recovering the spectral energy distribution of galaxies at different wavelengths, to reliably measure their properties at different cosmic times and in a large variety of environments. Analyzing the light collected by the instruments, observers try to disentangle the different processes occurring in galaxies at the scales of galactic physics, as well as the effect of larger scale processes such as mergers and accretion, in order to obtain a consistent picture of galaxy formation and evolution. On the other hand, hydrodynamical simulations of galaxy formation in cosmological context are able to follow the evolution of a galaxy along cosmic time, taking into account both external processes such as mergers, interactions and accretion, and internal mechanisms such as feedback from Supernovae and Active Galactic Nuclei. Due to the great advances in both fields of research, we have nowadays available spectral and photometric information for a large number of galaxies in the Universe at different cosmic times, which has in turn provided important knowledge about the evolution of the Universe; at the same time, we are able to realistically simulate galaxy formation and evolution in large volumes of the Universe, taking into account the most relevant physical processes occurring in galaxies. As these two approaches are intrinsically different in their methodology and in the information they provide, the connection between simulations and observations is still not fully established, although simulations are often used in galaxies' studies to interpret observations and assess the effect of the different processes acting on galaxies on the observable properties, and simulators usually test the physical recipes implemented in their hydrodynamical codes through the comparison with observations. In this dissertation we aim to better connect the observational and computational approaches in the study of galaxy formation and evolution, using the methods and results of one field to test and validate the methods and results of the other. In a first work we study the biases and systematics in the derivation of the galaxy properties in observations. We post-process hydrodynamical cosmological simulations of galaxy formation to calculate the galaxies' Spectral Energy Distributions (SEDs) using different approaches, including radiative transfer techniques. Comparing the direct results of the simulations with the quantities obtained applying observational techniques to these synthetic SEDs, we are able to make an analysis of the biases intrinsic in the observational algorithms, and quantify their accuracy in recovering the galaxies' properties, as well as estimating the uncertainties affecting a comparison between simulations and observations when different approaches to obtain the observables are followed. Our results show that for some quantities such as the stellar ages, metallicities and gas oxygen abundances large differences can appear, depending on the technique applied in the derivation. In a second work we compare a set of fifteen galaxies similar in mass to the Milky Way and with a quiet merger history in the recent past (hence expected to have properties close to spiral galaxies), simulated in a cosmological context, with data from the Sloan Digital Sky Survey (SDSS). We use techniques to obtain the observables as similar as possible to the ones applied in SDSS, with the aim of making an unbiased comparison between our set of hydrodynamical simulations and SDSS observations. We quantify the differences in the physical properties when these are obtained directly from the simulations without post-processing, or mimicking the SDSS observational techniques. We fit linear relations between the values derived directly from the simulations and following SDSS observational procedures, which in most of the cases have relatively high correlation, that can be easily used to more reliably compare simulations with SDSS data. When mimicking SDSS techniques, these simulated galaxies are photometrically similar to galaxies in the SDSS blue sequence/green valley, but have in general older ages, lower SFRs and metallicities compared to the majority of the spirals in the observational dataset. In a third work, we post-process hydrodynamical simulations of galaxies with radiative transfer techniques, to generate synthetic data that mimic the properties of the CALIFA Integral Field Spectroscopy (IFS) survey. We reproduce the main characteristics of the CALIFA observations in terms of field of view and spaxel physical size, data format, point spread functions and detector noise. This 3-dimensional dataset is suited to be analyzed by the same algorithms applied to the CALIFA dataset, and can be used as a tool to test the ability of the observational algorithms in recovering the properties of the CALIFA galaxies. To this purpose, we also generate the resolved maps of the simulations' properties, calculated directly from the hydrodynamical snapshots, or from the simulated spectra prior to the addition of the noise. Our work shows that a reliable connection between the models and the data is of crucial importance both to judge the output of galaxy formation codes and to accurately test the observational algorithms used in the analysis of galaxy surveys' data. A correct interpretation of observations will be particularly important in the future, in light of the several ongoing and planned large galaxy surveys that will provide the community with large datasets of properties of galaxies (often spatially-resolved) at different cosmic times, allowing to study galaxy formation physics at a higher level of detail than ever before. We have shown that neglecting the observational biases in the comparison between simulations and an observational dataset may move the simulations to different regions in the planes of the observables, strongly affecting the assessment of the correctness of the sub-resolution physical models implemented in galaxy formation codes, as well as the interpretation of given observational results using simulations.},
  language  = {en}
}
@phdthesis{Danken2017,
  author    = {Danken, Thomas},
  title     = {Coordination of wicked problems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-396766},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VI, 237},
  year      = {2017},
  abstract  = {The thesis focuses on the inter-departmental coordination of adaptation and mitigation of demographic change in East Germany. All Eastern German States (L{\"a}nder) have set up inter-departmental committees (IDCs) that are expected to deliver joint strategies to tackle demographic change. IDCs provide an organizational setting for potential positive coordination, i.e. a joint approach to problem solving that pools and utilizes the expertise of many departments in a constructive manner from the very beginning. Whether they actually achieve positive coordination is contested within the academic debate. This motivates the first research question of this thesis: Do IDCs achieve positive coordination? Interdepartmental committees and their role in horizontal coordination within the core executive triggered interest among scholars already more than fifty years ago. However, we don't know much about their actual importance for the inter-departmental preparation of cross-cutting policies. Until now, few studies can be found that analyzes inter-departmental committees in a comparative way trying to identify whether they achieve positive coordination and what factors shape the coordination process and output of IDCs. Each IDC has a chair organization that is responsible for managing the interactions within the IDCs. The chair organization is important, because it organizes and structures the overall process of coordination in the IDC. Consequently, the chair of an IDC serves as the main boundary-spanner and therefore has remarkable influence by arranging meetings and the work schedule or by distributing internal roles. Interestingly, in the German context we find two organizational approaches: while some states decided to put a line department (e.g. Department of Infrastructure) in charge of managing the IDC, others rely on the State Chancelleries, i.e. the center of government. This situation allows for comparative research design that can address the role of the State Chancellery in inter-departmental coordination of cross-cutting policies. This is relevant, because the role of the center is crucial when studying coordination within central government. The academic debate on the center of government in the German politico-administrative system is essentially divided into two camps. One camp claims that the center can improve horizontal coordination and steer cross-cutting policy-making more effectively, while the other camp points to limits to central coordination due to departmental autonomy. This debate motivates the second research question of this thesis: Does the State Chancellery as chair organization achieve positive coordination in IDCs? The center of government and its role in the German politic-administrative system has attracted academic attention already in the 1960s and 1970s. There is a research desiderate regarding the center's role during the inter-departmental coordination process. There are only few studies that explicitly analyze centers of government and their role in coordination of cross-cutting policies, although some single case studies have been published. This gap in the academic debate will be addressed by the answer to the second research question. The dependent variable of this study is the chair organization of IDCs. The value of this variable is dichotomous: either an IDC is chaired by a Line department or by a State Chancellery. We are interested whether this variable has an effect on two dependent variables. First, we will analyze the coordination process, i.e. interaction among bureaucrats within the IDC. Second, the focus of this thesis will be on the coordination result, i.e. the demography strategies that are produced by the respective IDCs. In terms of the methodological approach, this thesis applies a comparative case study design based on a most-similar-systems logic. The German Federalism is quite suitable for such designs. Since the institutional framework largely is the same across all states, individual variables and their effect can be isolated and plausibly analyzed. To further control for potential intervening variables, we will limit our case selection to states located in East Germany, because the demographic situation is most problematic in the Eastern part of Germany, i.e. there is a equal problem pressure. Consequently, we will analyze five cases: Thuringia, Saxony-Anhalt (line department) and Brandenburg, Mecklenburg-Vorpommern and Saxony (State Chancellery). There is no grand coordination theory that is ready to be applied to our case studies. Therefore, we need to tailor our own approach. Our assumption is that the individual chair organization has an effect on the coordination process and output of IDCs, although all cases are embedded in the same institutional setting, i.e. the German politico-administrative system. Therefore, we need an analytical approach than incorporates institutionalist and agency-based arguments. Therefore, this thesis will utilize Actor-Centered Institutionalism (ACI). Broadly speaking, ACI conceptualizes actors' behavior as influenced - but not fully determined - by institutions. Since ACI is rather abstract we need to adapt it for the purpose of this thesis. Line Departments and State Chancelleries will be modeled as distinct actors with different action orientations and capabilities to steer the coordination process. However, their action is embedded within the institutional context of governments, which we will conceptualize as being comprised of regulative (formal rules) and normative (social norms) elements.},
  language  = {en}
}
@phdthesis{Abouelmaati2017,
  author    = {Abouelmaati, Sherif Abdelfattah Abdelaziz},
  title     = {Intellektuellen-Rolle in G{\"u}nter Grass Werken},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-396736},
  school      = {Universit{\"a}t Potsdam},
  pages     = {244},
  year      = {2017},
  abstract  = {Die vorliegende Arbeit tr{\"a}gt den Titel: Intellektuellen-Rolle in G{\"u}nter Grass Werken : „Die Plebejer proben den Aufstand"(1966), „{\"O}rtlich bet{\"a}ubt"(1969), „Aus dem Tagebuch einer Schnecke"(1972), und „Ein weites Feld"(1995). Das erste Kapitel befasst sich insgesamt mit drei Haupttiteln II. Der Intellektuelle II.1 Das allgemeine Umfeld In diesem Teil der Dissertation sollen Aussagen getroffen werden, die auf folgende und weitere Fragen eine Antwort geben: Was ist ein Intellektueller? Wie kam der Begriff zustande? Gibt es Unterschiede zwischen den Intellektuellen und wie werden sie eingeteilt? II.2 Das deutsche Umfeld Die Behandlung des Nazisystems und dessen historische Hintergr{\"u}nde vermittelt bedeutsame Lehren. Aber wozu braucht man diese Lehren? Gibt es Spuren von Nationalsozialismus heutzutage? Wo waren die Intellektuellen bei der Bildung des Nationalsozialismus? Ist der Nationalsozialismus erst mit Hitler aufgetaucht? Wenn zuvor, in welcher Phase hat er sich im Bewusstsein der Deutschen verankert? Ob theoretische bzw. geistige Tendenzen dazu beigetragen haben? II.3 Das Bild von Grass als Intellektueller II.3.1 Positionierung Eine Hauptthese f{\"u}r Grass intellektuelle Positionierung wird durch die Verbindung zwischen Grass' Grundkonzeption der gesellschaftspolitischen Intellektualit{\"a}t und der Gruppe 47 ermittelt. Dann bezweckt die Behandlung von Grass Bild nach Erscheinen seines autobiographischen Werks: „Beim H{\"a}uten der Zwiebel" (2006), dass seine Intellektualit{\"a}t nicht nur aus dem positiven, sondern auch aus dem negativen Profil beleuchtet wird. Aus der Darstellung zahlreicher Ansichten von G{\"u}nter Grass werden f{\"u}nf thematische Kernpunkte als Konzepte behandelt. Unter jedem Konzept sollen spezifische Vorschl{\"a}ge zur gesellschaftlichen Positionierung aufgezeigt werden. II.3.2 Grass' politische Merkmale Es handelt sich hier um die intellektuellen Charaktereigenschaften. Dadurch kommen manche Fragen zu Wort: Hat G{\"u}nter Grass gesellschaftliche Aktivit{\"a}ten? Hat er die Voraussetzungen daf{\"u}r? Wie ist der Umfang seiner Aktivit{\"a}ten? Hat die Gruppe 47 Einfluss auf Grass intellektuelle Merkmale? Steht bei Grass eine Methode der gesellschaftspolitischen Arbeit zur Verf{\"u}gung? Dann wird die politische Sprache von G{\"u}nter Grass und ihre Wirkung auf den Rezipienten untersucht. Danach wird nach Grass' Auffassung von der Revision gefragt und ob sie mit seiner Auffassung der Aufkl{\"a}rung zusammenpasst. Darauf wird die Funktion der Revision in seinem literarischen Werk und in seiner gesellschaftspolitischen Aktivit{\"a}t gezeigt. Abschließend werden die Argumente seiner Intellektualit{\"a}t untersucht: Wie hat Grass' gesellschaftspolitische Aktivit{\"a}t den konkreten politischen Rahmen ber{\"u}cksichtigt? Um diese Frage zu beantworten, muss der Zusammenhang zwischen Politik und Moral verdeutlicht werden. III. Historischer Kontext und Inhalt der Werke Unter diesem Titel wird erstens der historische Zusammenhang der untersuchten Werke skizziert. Dann werden meistens durch Argumente aus jedem Werk selbst nicht nur der Kern des Werkes und sein Handlungsverlauf, sondern auch die daf{\"u}r angewandte Methode dargestellt. IV. Bezug der untersuchten Werke zu konkreten gesellschaftspolitischen Fragen IV.1 Interaktionswege des Intellektuellen mit der Gesellschaft, vor allem beim Wandel gesellschaftspolitischer Prozesse Zentralkonzepte des ersten Werkes sind: Vermittlung, Engagement, Solidarit{\"a}t und die Aktualit{\"a}t als Maßstab. Diese werden durch zwei Konzepte des zweiten Werkes: Appell an Generationen beim Wechsel und Zusammenhaltsprinzip an Revision gebunden, sowie durch die Behandlung vom Prozess der Meinungsbildung im vierten Werk ausgearbeitet. IV.2 Thematische Aspekte zur Vermeidung eines Naziregimes Aus den thematischen Perspektiven der drei letzten Werke geht eine bunte Sammlung intellektueller Konzepte aus, die zur Bek{\"a}mpfung von Nazivorspr{\"u}nge verwendet werden k{\"o}nnen. V. P{\"a}dagogische Strategien der untersuchten Werke Die p{\"a}dagogischen Aspekte der untersuchten Werke sollen intellektuelle Werte vermitteln, die einen bedeutenden Beitrag zur L{\"o}sung gesellschaftspolitischer Probleme und Konflikte leisten. VI. Entwicklung der literarischen und gesellschaftspolitischen Vision Hier wird die Entwicklungslinie der gesellschaftspolitischen Vision in den untersuchten Werken verfolgt. VII. Zur Rezeption der vier Werke Durch die Auseinandersetzung mit der negativen Kritik wird angestrebt, ihre Subjektivit{\"a}t darzulegen, damit der gesellschaftspolitische Wert der vier Werke enth{\"u}llt wird.},
  language  = {de}
}
@phdthesis{Tyree2017,
  author    = {Tyree, Susan},
  title     = {Arc expression in the parabrachial nucleus following taste stimulation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-396600},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIII, 109},
  year      = {2017},
  abstract  = {Researchers have made many approaches to study the complexities of the mammalian taste system; however molecular mechanisms of taste processing in the early structures of the central taste pathway remain unclear. More recently the Arc catFISH (cellular compartment analysis of temporal activity by fluorescent in situ hybridisation) method has been used in our lab to study neural activation following taste stimulation in the first central structure in the taste pathway, the nucleus of the solitary tract. This method uses the immediate early gene Arc as a neural activity marker to identify taste-responsive neurons. Arc plays a critical role in memory formation and is necessary for conditioned taste aversion memory formation. In the nucleus of the solitary tract only bitter taste stimulation resulted in increased Arc expression, however this did not occur following stimulation with tastants of any other taste quality. The primary target for gustatory NTS neurons is the parabrachial nucleus (PbN) and, like Arc, the PbN plays an important role in conditioned taste aversion learning. The aim of this thesis is to investigate Arc expression in the PbN following taste stimulation to elucidate the molecular identity and function of Arc expressing, taste- responsive neurons. Naïve and taste-conditioned mice were stimulated with tastants from each of the five basic taste qualities (sweet, salty, sour, umami, and bitter), with additional bitter compounds included for comparison. The expression patterns of Arc and marker genes were analysed using in situ hybridisation (ISH). The Arc catFISH method was used to observe taste-responsive neurons following each taste stimulation. A double fluorescent in situ hybridisation protocol was then established to investigate possible neuropeptide genes involved in neural responses to taste stimulation. The results showed that bitter taste stimulation induces increased Arc expression in the PbN in naïve mice. This was not true for other taste qualities. In mice conditioned to find an umami tastant aversive, subsequent umami taste stimulation resulted in an increase in Arc expression similar to that seen in bitter-stimulated mice. Taste-responsive Arc expression was denser in the lateral PbN than the medial PbN. In mice that received two temporally separated taste stimulations, each stimulation time-point showed a distinct population of Arc-expressing neurons, with only a small population (10 - 18 \%) of neurons responding to both stimulations. This suggests that either each stimulation event activates a different population of neurons, or that Arc is marking something other than simple cellular activation, such as long-term cellular changes that do not occur twice within a 25 minute time frame. Investigation using the newly established double-FISH protocol revealed that, of the bitter-responsive Arc expressing neuron population: 16 \% co-expressed calcitonin RNA; 17 \% co-expressed glucagon-like peptide 1 receptor RNA; 17 \% co-expressed hypocretin receptor 1 RNA; 9 \% co-expressed gastrin-releasing peptide RNA; and 20 \% co-expressed neurotensin RNA. This co-expression with multiple different neuropeptides suggests that bitter-activated Arc expression mediates multiple neural responses to the taste event, such as taste aversion learning, suppression of food intake, increased heart rate, and involves multiple brain structures such as the lateral hypothalamus, amygdala, bed nucleus of the stria terminalis, and the thalamus. The increase in Arc-expression suggests that bitter taste stimulation, and umami taste stimulation in umami-averse animals, may result in an enhanced state of Arc- dependent synaptic plasticity in the PbN, allowing animals to form taste-relevant memories to these aversive compounds more readily. The results investigating neuropeptide RNA co- expression suggest the amygdala, bed nucleus of the stria terminalis, and thalamus as possible targets for bitter-responsive Arc-expressing PbN neurons.},
  language  = {en}
}
@phdthesis{Anders2017,
  author    = {Anders, Friedrich},
  title     = {Disentangling the chemodynamical history of the Milky Way disc with asteroseismology and spectroscopy},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-396681},
  school      = {Universit{\"a}t Potsdam},
  pages     = {121},
  year      = {2017},
  abstract  = {Galaxies are among the most complex systems that can currently be modelled with a computer. A realistic simulation must take into account cosmology and gravitation as well as effects of plasma, nuclear, and particle physics that occur on very different time, length, and energy scales. The Milky Way is the ideal test bench for such simulations, because we can observe millions of its individual stars whose kinematics and chemical composition are records of the evolution of our Galaxy. Thanks to the advent of multi-object spectroscopic surveys, we can systematically study stellar populations in a much larger volume of the Milky Way. While the wealth of new data will certainly revolutionise our picture of the formation and evolution of our Galaxy and galaxies in general, the big-data era of Galactic astronomy also confronts us with new observational, theoretical, and computational challenges. This thesis aims at finding new observational constraints to test Milky-Way models, primarily based on infra-red spectroscopy from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and asteroseismic data from the CoRoT mission. We compare our findings with chemical-evolution models and more sophisticated chemodynamical simulations. In particular we use the new powerful technique of combining asteroseismic and spectroscopic observations that allows us to test the time dimension of such models for the first time. With CoRoT and APOGEE (CoRoGEE) we can infer much more precise ages for distant field red-giant stars, opening up a new window for Galactic archaeology. Another important aspect of this work is the forward-simulation approach that we pursued when interpreting these complex datasets and comparing them to chemodynamical models. The first part of the thesis contains the first chemodynamical study conducted with the APOGEE survey. Our sample comprises more than 20,000 red-giant stars located within 6 kpc from the Sun, and thus greatly enlarges the Galactic volume covered with high-resolution spectroscopic observations. Because APOGEE is much less affected by interstellar dust extinction, the sample covers the disc regions very close to the Galactic plane that are typically avoided by optical surveys. This allows us to investigate the chemo-kinematic properties of the Milky Way's thin disc outside the solar vicinity. We measure, for the first time with high-resolution data, the radial metallicity gradient of the disc as a function of distance from the Galactic plane, demonstrating that the gradient flattens and even changes its sign for mid-plane distances greater than 1 kpc. Furthermore, we detect a gap between the high- and low-[\$\alpha\$/Fe] sequences in the chemical-abundance diagram (associated with the thin and thick disc) that unlike in previous surveys can hardly be explained by selection effects. Using 6D kinematic information, we also present chemical-abundance diagrams cleaned from stars on kinematically hot orbits. The data allow us to confirm without doubt that the scale length of the (chemically-defined) thick disc is significantly shorter than that of the thin disc. In the second part, we present our results of the first combination of asteroseismic and spectroscopic data in the context of Galactic Archaeology. We analyse APOGEE follow-up observations of 606 solar-like oscillating red giants in two CoRoT fields close to the Galactic plane. These stars cover a large radial range of the Galactic disc (4.5 kpc \$\lesssim R_{\rm Gal}\lesssim15\$ kpc) and a large age baseline (0.5 Gyr \$\lesssim \tau\lesssim\$ 13 Gyr), allowing us to study the age- and radius-dependence of the [\$\alpha\$/Fe] vs. [Fe/H] distributions. We find that the age distribution of the high-[\$\alpha\$/Fe] sequence appears to be broader than expected from a monolithically-formed old thick disc that stopped to form stars 10 Gyr ago. In particular, we discover a significant population of apparently young, [\$\alpha\$/Fe]-rich stars in the CoRoGEE data whose existence cannot be explained by standard chemical-evolution models. These peculiar stars are much more abundant in the inner CoRoT field LRc01 than in the outer-disc field LRc01, suggesting that at least part of this population has a chemical-evolution rather than a stellar-evolution origin, possibly due to a peculiar chemical-enrichment history of the inner disc. We also find that strong radial migration is needed to explain the abundance of super-metal-rich stars in the outer disc. Finally, we use the CoRoGEE sample to study the time evolution of the radial metallicity gradient in the thin disc, an observable that has been the subject of observational and theoretical debate for more than 20 years. By dividing the CoRoGEE dataset into six age bins, performing a careful statistical analysis of the radial [Fe/H], [O/H], and [Mg/Fe] distributions, and accounting for the biases introduced by the observation strategy, we obtain reliable gradient measurements. The slope of the radial [Fe/H] gradient of the young red-giant population (\$-0.058\pm0.008\$ [stat.] \$\pm0.003\$ [syst.] dex/kpc) is consistent with recent Cepheid data. For the age range of \$1-4\$ Gyr, the gradient steepens slightly (\$-0.066\pm0.007\pm0.002\$ dex/kpc), before flattening again to reach a value of \$\sim-0.03\$ dex/kpc for stars with ages between 6 and 10 Gyr. This age dependence of the [Fe/H] gradient can be explained by a nearly constant negative [Fe/H] gradient of \$\sim-0.07\$ dex/kpc in the interstellar medium over the past 10 Gyr, together with stellar heating and migration. Radial migration also offers a new explanation for the puzzling observation that intermediate-age open clusters in the solar vicinity (unlike field stars) tend to have higher metallicities than their younger counterparts. We suggest that non-migrating clusters are more likely to be kinematically disrupted, which creates a bias towards high-metallicity migrators from the inner disc and may even steepen the intermediate-age cluster abundance gradient.},
  language  = {en}
}
@phdthesis{Dribbisch2017,
  author    = {Dribbisch, Katrin},
  title     = {Translating innovation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-104719},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 217},
  year      = {2017},
  abstract  = {This doctoral thesis studies the process of innovation adoption in public administrations, addressing the research question of how an innovation is translated to a local context. The study empirically explores Design Thinking as a new problem-solving approach introduced by a federal government organisation in Singapore. With a focus on user-centeredness, collaboration and iteration Design Thinking seems to offer a new way to engage recipients and other stakeholders of public services as well as to re-think the policy design process from a user's point of view. Pioneered in the private sector, early adopters of the methodology include civil services in Australia, Denmark, the United Kingdom, the United States as well as Singapore. Hitherto, there is not much evidence on how and for which purposes Design Thinking is used in the public sector. For the purpose of this study, innovation adoption is framed in an institutionalist perspective addressing how concepts are translated to local contexts. The study rejects simplistic views of the innovation adoption process, in which an idea diffuses to another setting without adaptation. The translation perspective is fruitful because it captures the multidimensionality and 'messiness' of innovation adoption. More specifically, the overall research question addressed in this study is: How has Design Thinking been translated to the local context of the public sector organisation under investigation? And from a theoretical point of view: What can we learn from translation theory about innovation adoption processes? Moreover, there are only few empirical studies of organisations adopting Design Thinking and most of them focus on private organisations. We know very little about how Design Thinking is embedded in public sector organisations. This study therefore provides further empirical evidence of how Design Thinking is used in a public sector organisation, especially with regards to its application to policy work which has so far been under-researched. An exploratory single case study approach was chosen to provide an in-depth analysis of the innovation adoption process. Based on a purposive, theory-driven sampling approach, a Singaporean Ministry was selected because it represented an organisational setting in which Design Thinking had been embedded for several years, making it a relevant case with regard to the research question. Following a qualitative research design, 28 semi-structured interviews (45-100 minutes) with employees and managers were conducted. The interview data was triangulated with observations and documents, collected during a field research research stay in Singapore. The empirical study of innovation adoption in a single organisation focused on the intra-organisational perspective, with the aim to capture the variations of translation that occur during the adoption process. In so doing, this study opened the black box often assumed in implementation studies. Second, this research advances translation studies not only by showing variance, but also by deriving explanatory factors. The main differences in the translation of Design Thinking occurred between service delivery and policy divisions, as well as between the first adopter and the rest of the organisation. For the intra-organisational translation of Design Thinking in the Singaporean Ministry the following five factors played a role: task type, mode of adoption, type of expertise, sequence of adoption, and the adoption of similar practices.},
  language  = {en}
}
@phdthesis{Georgiev2017,
  author    = {Georgiev, Vasil},
  title     = {Light-induced transformations in biomembranes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-395309},
  school      = {Universit{\"a}t Potsdam},
  pages     = {81},
  year      = {2017},
  abstract  = {Cellular membranes constantly experience remodeling, as exemplified by morphological changes during endo- and exocytosis. Regulation of membrane morphology is essential for these processes. In this work, we attempt to establish a regulation path based on the use of photoswitches exhibiting conformational changes in model membranes, namely, giant unilamellar vesicles (GUVs). The mechanism of the changes in the GUVs' morphology caused by isomerization of the photosensitive molecules has been previously explored but still remains elusive. We examine the morphological reshaping of GUVs in the presence of the photoswitch o-tetrafluoroazobenzene (F-azo) and show that the mechanism behind the resulting morphological changes involves both an increase in the membrane area and generation of a positive spontaneous curvature. First, we characterize the partitioning of F-azo in a single-component membrane using both experimental and computational approaches. The partition coefficient calculated from molecular dynamic simulations agrees with experimental data obtained with size-exclusion chromatography. Then, we implement the approach of vesicle electrodeformation in order to assess the increase in the membrane area, which is observed as a result of the conformational change of F-azo. Finally, the local and the effective membrane spontaneous curvatures were estimated from the observed shapes of vesicles exhibiting outward budding. We then extend the application of the F-azo to multicomponent lipid membranes, which exhibit a coexistence of domains in different liquid phases due to a miscibility gap between the lipids. We perform initial experiments to investigate whether F-azo can be employed to modulate the lateral lipid packing and organization. We observe either complete mixing of the domains or the appearing of disordered domains within the domains of more ordered phase. The type of behavior observed in response to the photoisomerization of F-azo was dependent on the used lipid composition. We believe that the findings introduced here will have an impact in understanding and controlling both lipid phase modulation and regulation of the membrane morphology in membrane systems.},
  language  = {en}
}
@phdthesis{Titov2017,
  author    = {Titov, Evgenii},
  title     = {Quantum chemistry and surface hopping dynamics of azobenzenes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394610},
  school      = {Universit{\"a}t Potsdam},
  pages     = {205},
  year      = {2017},
  abstract  = {This cumulative doctoral dissertation, based on three publications, is devoted to the investigation of several aspects of azobenzene molecular switches, with the aid of computational chemistry. In the first paper, the isomerization rates of a thermal cis → trans isomerization of azobenzenes for species formed upon an integer electron transfer, i.e., with added or removed electron, are calculated from Eyring's transition state theory and activation energy barriers, computed by means of density functional theory. The obtained results are discussed in connection with an experimental study of the thermal cis → trans isomerization of azobenzene derivatives in the presence of gold nanoparticles, which is demonstrated to be greatly accelerated in comparison to the same isomerization reaction in the absence of nanoparticles. The second paper is concerned with electronically excited states of (i) dimers, composed of two photoswitchable units placed closely side-by-side, as well as (ii) monomers and dimers adsorbed on a silicon cluster. A variety of quantum chemistry methods, capable of calculating molecular electronic absorption spectra, based on density functional and wave function theories, is employed to quantify changes in optical absorption upon dimerization and covalent grafting to a surface. Specifically, the exciton (Davydov) splitting between states of interest is determined from first-principles calculations with the help of natural transition orbital analysis, allowing for insight into the nature of excited states. In the third paper, nonadiabatic molecular dynamics with trajectory surface hopping is applied to model the photoisomerization of azobenzene dimers, (i) for the isolated case (exhibiting the exciton coupling between two molecules) as well as (ii) for the constrained case (providing the van der Waals interaction with environment in addition to the exciton coupling between two monomers). For the latter, the additional azobenzene molecules, surrounding the dimer, are introduced, mimicking a densely packed self-assembled monolayer. From obtained results it is concluded that the isolated dimer is capable of isomerization likewise the monomer, whereas the steric hindrance considerably suppresses trans → cis photoisomerization. Furthermore, the present dissertation comprises the general introduction describing the main features of the azobenzene photoswitch and objectives of this work, theoretical basis of the employed methods, and discussion of gained findings in the light of existing literature. Also, additional results on (i) activation parameters of the thermal cis → trans isomerization of azobenzenes, (ii) an approximate scheme to account for anharmonicity of molecular vibrations in calculation of the activation entropy, as well as (iii) absorption spectra of photoswitch-silicon composites obtained from time-demanding wave function-based methods are presented.},
  language  = {en}
}
@phdthesis{Shenar2017,
  author    = {Shenar, Tomer},
  title     = {Comprehensive analyses of massive binaries and implications on stellar evolution},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-104857},
  school      = {Universit{\"a}t Potsdam},
  pages     = {187},
  year      = {2017},
  abstract  = {Via their powerful radiation, stellar winds, and supernova explosions, massive stars (Mini \& 8 M☉) bear a tremendous impact on galactic evolution. It became clear in recent decades that the majority of massive stars reside in binary systems. This thesis sets as a goal to quantify the impact of binarity (i.e., the presence of a companion star) on massive stars. For this purpose, massive binary systems in the Local Group, including OB-type binaries, high mass X-ray binaries (HMXBs), and Wolf-Rayet (WR) binaries, were investigated by means of spectral, orbital, and evolutionary analyses. The spectral analyses were performed with the non-local thermodynamic equillibrium (non-LTE) Potsdam Wolf-Rayet (PoWR) model atmosphere code. Thanks to critical updates in the calculation of the hydrostatic layers, the code became a state-of-the-art tool applicable for all types of hot massive stars (Chapter 2). The eclipsing OB-type triple system δ Ori served as an intriguing test-case for the new version of the PoWR code, and provided key insights regarding the formation of X-rays in massive stars (Chapter 3). We further analyzed two prototypical HMXBs, Vela X-1 and IGR J17544-2619, and obtained fundamental conclusions regarding the dichotomy of two basic classes of HMXBs (Chapter 4). We performed an exhaustive analysis of the binary R 145 in the Large Magellanic Cloud (LMC), which was claimed to host the most massive stars known. We were able to disentangle the spectrum of the system, and performed an orbital, polarimetric, and spectral analysis, as well as an analysis of the wind-wind collision region. The true masses of the binary components turned out to be significantly lower than suggested, impacting our understanding of the initial mass function and stellar evolution at low metallicity (Chapter 5). Finally, all known WR binaries in the Small Magellanic Cloud (SMC) were analyzed. Although it was theoretical predicted that virtually all WR stars in the SMC should be formed via mass-transfer in binaries, we find that binarity was not important for the formation of the known WR stars in the SMC, implying a strong discrepancy between theory and observations (Chapter 6).},
  language  = {en}
}
@phdthesis{Muehlenhoff2017,
  author    = {M{\"u}hlenhoff, Judith},
  title     = {Culture-driven innovation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-104626},
  school      = {Universit{\"a}t Potsdam},
  pages     = {143},
  year      = {2017},
  abstract  = {This cumulative dissertation deals with the potential of underexplored cultural sources for innovation. Nowadays, firms recognize an increasing demand for innovation to keep pace with an ever-growing dynamic worldwide competition. Knowledge is one of the most crucial sources and resource, while until now innovation has been foremost driven by technology. But since the last years, we have been witnessing a change from technology's role as a driver of innovation to an enabler of innovation. Innovative products and services increasingly differentiate through emotional qualities and user experience. These experiences are hard to grasp and require alignment in innovation management theory and practice. This work cares about culture in a broader matter as a source for innovation. It investigates the requirements and fundamentals for "culture-driven innovation" by studying where and how to unlock cultural sources. The research questions are the following: What are cultural sources for knowledge and innovation? Where can one find cultural sources and how to tap into them? The dissertation starts with an overview of its central terms and introduces cultural theories as an overarching frame to study cultural sources for innovation systematically. Here, knowledge is not understood as something an organization owns like a material resource, but it is seen as something created and taking place in practices. Such a practice theoretical lens inheres the rejection of the traditional economic depiction of the rational Homo Oeconomicus. Nevertheless, it also rejects the idea of the Homo Sociologicus about the strong impact of society and its values on individual actions. Practice theory approaches take account of both concepts by underscoring the dualism of individual (agency, micro-level) and structure (society, macro-level). Following this, organizations are no enclosed entities but embedded within their socio-cultural environment, which shapes them and is also shaped by them. Then, the first article of this dissertation acknowledges a methodological stance of this dualism by discussing how mixed methods support an integrated approach to study the micro- and macro-level. The article focuses on networks (thus communities) as a central research unit within studies of entrepreneurship and innovation. The second article contains a network analysis and depicts communities as central loci for cultural sources and knowledge. With data from the platform Meetup.com about events etc., the study explores which overarching communities and themes have been evolved in Berlin's start up and tech scene. While the latter study was about where to find new cultural sources, the last article addresses how to unlock such knowledge sources. It develops the concept of a cultural absorptive capacity, that is the capability of organizations to open up towards cultural sources. Furthermore, the article points to the role of knowledge intermediaries in the early phases of knowledge acquisition. Two case studies on companies working with artists illustrate the roles of such intermediaries and how they support firms to gain knowledge from cultural sources. Overall, this dissertation contributes to a better understanding of culture as a source for innovation from a theoretical, methodological, and practitioners' point of view. It provides basic research to unlock the potential of such new knowledge sources for companies - sources that so far have been neglected in innovation management.},
  language  = {en}
}