@article{HartmannHelbigBiernackaetal.2019, author = {Hartmann, Niklas K. and Helbig, Kerstin and Biernacka, Katarzyna and Buchholz, Petra and Dolzycka, Dominika and Hartmann, Thomas and Hiemenz, Bea and Jacob, Boris and Kuberek, Monika and Weiß, Nadin and Dreyer, Malte}, title = {L{\"o}sungen und Leitf{\"a}den f{\"u}r das institutionelle Forschungsdatenmanagement}, series = {o-bib Das offene Bibliotheksjournal}, volume = {6}, journal = {o-bib Das offene Bibliotheksjournal}, number = {3}, publisher = {VDB - Verein Deutscher Bibliothekarinnen und Bibliothekare e.V.}, address = {Erlangen}, issn = {2363-9814}, doi = {10.5282/o-bib/2019H3S21-39}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472370}, pages = {21 -- 39}, year = {2019}, abstract = {Hochschulen und deren Zentraleinrichtungen besch{\"a}ftigen sich zunehmend mit dem Thema Forschungsdatenmanagement (FDM), um ihre Forschenden ad{\"a}quat zu unterst{\"u}tzen. Nicht zuletzt aufgrund neuer Verlags- und F{\"o}rderanforderungen w{\"u}nschen sich Forschende Beratung und Orientierung, wie sie mit ihren Forschungsdaten umgehen sollen. Damit Hochschulen schnell und nachhaltig L{\"o}sungen zum institutionellen FDM etablieren k{\"o}nnen, haben f{\"u}nf Berliner und Brandenburger Universit{\"a}ten im gemeinsamen Verbundvorhaben FDMentor mit F{\"o}rderung des Bundesministeriums f{\"u}r Bildung und Forschung (BMBF) entsprechende Leitf{\"a}den und Werkzeuge erarbeitet. Die innerhalb von zwei Jahren (2017-2019) entstandenen Ergebnisse in den Bereichen Strategieentwicklung, Forschungsdaten-Policy, rechtliche Aspekte und Kompetenzausbau finden {\"u}ber das Verbundprojekt hinaus ihre Anwendung.}, language = {de} } @misc{Pilarczyk2019, type = {Master Thesis}, author = {Pilarczyk, Paulina}, title = {Der Einsatz lateinamerikanischer Telenovelas im Spanischunterricht am Beispiel von Yo soy Betty, la fea}, doi = {10.25932/publishup-43100}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431006}, school = {Universit{\"a}t Potsdam}, pages = {114}, year = {2019}, abstract = {Das Ziel dieser Arbeit ist es, das Potenzial lateinamerikanischer Telenovelas als audiovisuelle Medien f{\"u}r den Fremdsprachenunterricht Spanisch und deren Eignung f{\"u}r die F{\"o}rderung der funktionalen kommunikativen Kompetenz, der interkulturellen kommunikativen Kompetenz und der Medienkompetenz aufzuzeigen. Der Schwerpunkt dieser Untersuchung liegt dabei im lateinamerikanischen Spanisch und der lateinamerikanischen Kultur. Zu diesem Zweck werden ausgew{\"a}hlte Szenen aus der weltweit popul{\"a}rsten kolumbianischen Telenovela Yo soy Betty, la fea analysiert. Es werden zwei Szenen aus dem Arbeitsleben und zwei Szenen aus dem Privatleben in Hinblick auf die funktionale kommunikative Kompetenz untersucht. Des Weiteren werden die kulturellen Elemente in dieser Telenovela w{\"a}hrend der Analyse geschildert. Schließlich wird die Telenovela mit dem Fokus auf die Medienkompetenz, daher auf die Eigenschaften und Konventionen des Genres Telenovela, hin untersucht.}, language = {de} } @misc{AbbasVranicHoffmannetal.2019, author = {Abbas, Ioana M. and Vranic, Marija and Hoffmann, Holger and El-Khatib, Ahmed H. and Montes-Bay{\´o}n, Mar{\´i}a and M{\"o}ller, Heiko Michael and Weller, Michael G.}, title = {Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR⁺}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {701}, issn = {1866-8372}, doi = {10.25932/publishup-42792}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427926}, year = {2019}, abstract = {Hepcidin-25 was identified as themain iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II) binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1\% ammonia. Further, mass spectrometry (tandemmass spectrometry (MS/MS), high-resolutionmass spectrometry (HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D)model of hepcidin-25with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or referencematerial comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.}, language = {en} } @techreport{SultanowKochCox2019, author = {Sultanow, Eldar and Koch, Christian and Cox, Sean}, title = {Collatz Sequences in the Light of Graph Theory}, edition = {2nd version}, doi = {10.25932/publishup-43741}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-437416}, pages = {21}, year = {2019}, abstract = {The Collatz conjecture is a number theoretical problem, which has puzzled countless researchers using myriad approaches. Presently, there are scarcely any methodologies to describe and treat the problem from the perspective of the Algebraic Theory of Automata. Such an approach is promising with respect to facilitating the comprehension of the Collatz sequence's "mechanics". The systematic technique of a state machine is both simpler and can fully be described by the use of algebraic means. The current gap in research forms the motivation behind the present contribution. The present authors are convinced that exploring the Collatz conjecture in an algebraic manner, relying on findings and fundamentals of Graph Theory and Automata Theory, will simplify the problem as a whole.}, language = {en} } @techreport{SultanowKochCox2019, author = {Sultanow, Eldar and Koch, Christian and Cox, Sean}, title = {Collatz Sequences in the Light of Graph Theory}, doi = {10.25932/publishup-43008}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-430089}, pages = {15}, year = {2019}, abstract = {The Collatz conjecture is a number theoretical problem, which has puzzled countless researchers using myriad approaches. Presently, there are scarcely any methodologies to describe and treat the problem from the perspective of the Algebraic Theory of Automata. Such an approach is promising with respect to facilitating the comprehension of the Collatz sequences "mechanics". The systematic technique of a state machine is both simpler and can fully be described by the use of algebraic means. The current gap in research forms the motivation behind the present contribution. The present authors are convinced that exploring the Collatz conjecture in an algebraic manner, relying on findings and fundamentals of Graph Theory and Automata Theory, will simplify the problem as a whole.}, language = {en} } @misc{KayhanWagnerMeyerO’Reillyetal.2019, author = {Kayhan Wagner, Ezgi and Meyer, Marlene and O'Reilly, J.X. and Hunnius, Sabine and Bekkering, Harold}, title = {Nine-month-old infants update their predictive models of a changing environment}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {577}, issn = {1866-8364}, doi = {10.25932/publishup-43784}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-437844}, pages = {8}, year = {2019}, abstract = {Humans generate internal models of their environment to predict events in the world. As the environments change, our brains adjust to these changes by updating their internal models. Here, we investigated whether and how 9-month-old infants differentially update their models to represent a dynamic environment. Infants observed a predictable sequence of stimuli, which were interrupted by two types of cues. Following the update cue, the pattern was altered, thus, infants were expected to update their predictions for the upcoming stimuli. Because the pattern remained the same after the no-update cue, no subsequent updating was required. Infants showed an amplified negative central (Nc) response when the predictable sequence was interrupted. Late components such as the PSW were also evoked in response to unexpected stimuli; however, we found no evidence for a differential response to the informational value of surprising cues at later stages of processing. Infants rather learned that surprising cues always signal a change in the environment that requires updating. Interestingly, infants responded with an amplified neural response to the absence of an expected change, suggesting a top-down modulation of early sensory processing in infants. Our findings corroborate emerging evidence showing that infants build predictive models early in life.}, language = {en} } @article{Klein2019, author = {Klein, Eckart}, title = {The Founding of the Human Rights Centre in 1994}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {24}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {1/2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, doi = {10.25932/publishup-43863}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438633}, pages = {5 -- 11}, year = {2019}, language = {en} } @article{WelkeFrank2019, author = {Welke, Lisa-Marie and Frank, Ulrike}, title = {Pilotfragebogenstudie zur praktischen Umsetzung und Koordination des Trachealkan{\"u}len-Managements in Berlin und Brandenburg}, series = {Spektrum Patholinguistik}, journal = {Spektrum Patholinguistik}, number = {11}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-448-7}, issn = {1866-9085}, doi = {10.25932/publishup-43778}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-437780}, pages = {115 -- 129}, year = {2019}, language = {de} } @phdthesis{Nikaj2019, author = {Nikaj, Adriatik}, title = {Restful choreographies}, doi = {10.25932/publishup-43890}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438903}, school = {Universit{\"a}t Potsdam}, pages = {xix, 146}, year = {2019}, abstract = {Business process management has become a key instrument to organize work as many companies represent their operations in business process models. Recently, business process choreography diagrams have been introduced as part of the Business Process Model and Notation standard to represent interactions between business processes, run by different partners. When it comes to the interactions between services on the Web, Representational State Transfer (REST) is one of the primary architectural styles employed by web services today. Ideally, the RESTful interactions between participants should implement the interactions defined at the business choreography level. The problem, however, is the conceptual gap between the business process choreography diagrams and RESTful interactions. Choreography diagrams, on the one hand, are modeled from business domain experts with the purpose of capturing, communicating and, ideally, driving the business interactions. RESTful interactions, on the other hand, depend on RESTful interfaces that are designed by web engineers with the purpose of facilitating the interaction between participants on the internet. In most cases however, business domain experts are unaware of the technology behind web service interfaces and web engineers tend to overlook the overall business goals of web services. While there is considerable work on using process models during process implementation, there is little work on using choreography models to implement interactions between business processes. This thesis addresses this research gap by raising the following research question: How to close the conceptual gap between business process choreographies and RESTful interactions? This thesis offers several research contributions that jointly answer the research question. The main research contribution is the design of a language that captures RESTful interactions between participants---RESTful choreography modeling language. Formal completeness properties (with respect to REST) are introduced to validate its instances, called RESTful choreographies. A systematic semi-automatic method for deriving RESTful choreographies from business process choreographies is proposed. The method employs natural language processing techniques to translate business interactions into RESTful interactions. The effectiveness of the approach is shown by developing a prototypical tool that evaluates the derivation method over a large number of choreography models. In addition, the thesis proposes solutions towards implementing RESTful choreographies. In particular, two RESTful service specifications are introduced for aiding, respectively, the execution of choreographies' exclusive gateways and the guidance of RESTful interactions.}, language = {en} } @misc{RungeGrosse2019, author = {Runge, Alexandra and Grosse, Guido}, title = {Comparing Spectral Characteristics of Landsat-8 and Sentinel-2 Same-Day Data for Arctic-Boreal Regions}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {767}, issn = {1866-8372}, doi = {10.25932/publishup-43866}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438660}, pages = {29}, year = {2019}, abstract = {The Arctic-Boreal regions experience strong changes of air temperature and precipitation regimes, which affect the thermal state of the permafrost. This results in widespread permafrost-thaw disturbances, some unfolding slowly and over long periods, others occurring rapidly and abruptly. Despite optical remote sensing offering a variety of techniques to assess and monitor landscape changes, a persistent cloud cover decreases the amount of usable images considerably. However, combining data from multiple platforms promises to increase the number of images drastically. We therefore assess the comparability of Landsat-8 and Sentinel-2 imagery and the possibility to use both Landsat and Sentinel-2 images together in time series analyses, achieving a temporally-dense data coverage in Arctic-Boreal regions. We determined overlapping same-day acquisitions of Landsat-8 and Sentinel-2 images for three representative study sites in Eastern Siberia. We then compared the Landsat-8 and Sentinel-2 pixel-pairs, downscaled to 60 m, of corresponding bands and derived the ordinary least squares regression for every band combination. The acquired coefficients were used for spectral bandpass adjustment between the two sensors. The spectral band comparisons showed an overall good fit between Landsat-8 and Sentinel-2 images already. The ordinary least squares regression analyses underline the generally good spectral fit with intercept values between 0.0031 and 0.056 and slope values between 0.531 and 0.877. A spectral comparison after spectral bandpass adjustment of Sentinel-2 values to Landsat-8 shows a nearly perfect alignment between the same-day images. The spectral band adjustment succeeds in adjusting Sentinel-2 spectral values to Landsat-8 very well in Eastern Siberian Arctic-Boreal landscapes. After spectral adjustment, Landsat and Sentinel-2 data can be used to create temporally-dense time series and be applied to assess permafrost landscape changes in Eastern Siberia. Remaining differences between the sensors can be attributed to several factors including heterogeneous terrain, poor cloud and cloud shadow masking, and mixed pixels.}, language = {en} } @misc{DahmaniLudwigChiantia2019, author = {Dahmani, Ismail and Ludwig, Kai and Chiantia, Salvatore}, title = {Influenza A matrix protein M1 induces lipid membrane deformation via protein multimerization}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {768}, issn = {1866-8372}, doi = {10.25932/publishup-43868}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438689}, pages = {16}, year = {2019}, abstract = {The matrix protein M1 of the Influenza A virus (IAV) is supposed to mediate viral assembly and budding at the plasma membrane (PM) of infected cells. In order for a new viral particle to form, the PM lipid bilayer has to bend into a vesicle toward the extracellular side. Studies in cellular models have proposed that different viral proteins might be responsible for inducing membrane curvature in this context (including M1), but a clear consensus has not been reached. In the present study, we use a combination of fluorescence microscopy, cryogenic transmission electron microscopy (cryo-TEM), cryo-electron tomography (cryo-ET) and scanning fluorescence correlation spectroscopy (sFCS) to investigate M1-induced membrane deformation in biophysical models of the PM. Our results indicate that M1 is indeed able to cause membrane curvature in lipid bilayers containing negatively charged lipids, in the absence of other viral components. Furthermore, we prove that protein binding is not sufficient to induce membrane restructuring. Rather, it appears that stable M1-M1 interactions and multimer formation are required in order to alter the bilayer three-dimensional structure, through the formation of a protein scaffold. Finally, our results suggest that, in a physiological context,M1-induced membrane deformation might be modulated by the initial bilayer curvature and the lateral organization of membrane components (i.e. the presence of lipid domains).}, language = {en} } @phdthesis{BarqueroPipin2019, author = {Barquero Pip{\´i}n, Antonio Carlos}, title = {Lengua, cultura, interculturalidad}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-480-7}, doi = {10.25932/publishup-43902}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439023}, school = {Universit{\"a}t Potsdam}, pages = {429}, year = {2019}, abstract = {Ohne Pragmatik w{\"a}re Kommunikation nicht m{\"o}glich, da wir sprachliche Aussagen nicht interpretieren k{\"o}nnten. F{\"u}r jeden Lernenden einer Sprache, die er nicht beherrscht, reicht es nicht aus, sprachlich kompetent zu sein, da der Zweck der Kommunikation darin besteht, mit anderen Menschen und in bestimmten Kontexten zu kommunizieren. Nur eine Lehre, die es erm{\"o}glicht, Aussagen zur Durchf{\"u}hrung von Sprachhandlungen zu erstellen und zu verstehen und die f{\"u}r einen bestimmten Kontext am besten geeigneten auszuw{\"a}hlen, kann sich als effizient erweisen. Die hier vorgestellte Arbeit zielt darauf ab, der wissenschaftlichen Gemeinschaft und insbesondere denjenigen, die direkt und indirekt am Unterrichtsprozess beteiligt sind, das Konzept der verbalen Pragmatik bekannt zu machen und es anderen wie Grammatik, Kultur oder Interkulturalit{\"a}t gegen{\"u}ber zu stellen. Ferner wendet sie sich der Frage zu, wie man auf die Bedeutung und die dringende Notwendigkeit aufmerksam macht, Pragmatik als relevante Disziplin im Kommunikationsprozess zu etablieren; dabei wird insbesondere auf ihre systematische Einbeziehung in Lehrb{\"u}chern f{\"u}r Spanisch als Fremdsprache, die f{\"u}r den schulischen Kontext konzipiert wurden, abgestellt. Dazu werden das Vorhandensein pragmatischer Elemente und die F{\"o}rderung pragmatischer Kompetenz in Lehrb{\"u}chern f{\"u}r Anf{\"a}nger sowie ihre Relevanz bei der Festlegung von Inhalten, Fortschrittsart und Methodik untersucht.}, language = {es} } @misc{PalyulinBlackburnLomholtetal.2019, author = {Palyulin, Vladimir V and Blackburn, George and Lomholt, Michael A and Watkins, Nicholas W and Metzler, Ralf and Klages, Rainer and Chechkin, Aleksei V.}, title = {First passage and first hitting times of L{\´e}vy flights and L{\´e}vy walks}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {785}, issn = {1866-8372}, doi = {10.25932/publishup-43983}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439832}, pages = {25}, year = {2019}, abstract = {For both L{\´e}vy flight and L{\´e}vy walk search processes we analyse the full distribution of first-passage and first-hitting (or first-arrival) times. These are, respectively, the times when the particle moves across a point at some given distance from its initial position for the first time, or when it lands at a given point for the first time. For L{\´e}vy motions with their propensity for long relocation events and thus the possibility to jump across a given point in space without actually hitting it ('leapovers'), these two definitions lead to significantly different results. We study the first-passage and first-hitting time distributions as functions of the L{\´e}vy stable index, highlighting the different behaviour for the cases when the first absolute moment of the jump length distribution is finite or infinite. In particular we examine the limits of short and long times. Our results will find their application in the mathematical modelling of random search processes as well as computer algorithms.}, language = {en} } @misc{KrahThulinFaiersteinetal.2019, author = {Krah, Markus and Thulin, Mirjam and Faierstein, Morris M. and Drori, Danielle and Coors, Maria and Schramm, Netta and Driver, Cory and Holzman, Gitit and Zuckermann, Ghil'ad and Fishbane, Eitan P. and Gruenbaum, Caroline and Schirrmeister, Sebastian and Ferrari, Francesco and Stemberger, G{\"u}nter and Schm{\"o}lz-H{\"a}berlein, Michaela and M{\"u}ller, Judith and Schulz, Michael Karl and Meyer, Thomas and Artwińska, Anna and Walter, Simon}, title = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien = Transformative Translations in Jewish History and Culture}, number = {25}, editor = {Krah, Markus and Thulin, Mirjam and Pick, Bianca}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-468-5}, issn = {1614-6492}, doi = {10.25932/publishup-43262}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-432621}, pages = {198}, year = {2019}, abstract = {PaRDeS, die Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e. V., erforscht die fruchtbare kulturelle Vielfalt des Judentums sowie ihre Ber{\"u}hrungspunkte zur nichtj{\"u}dischen Umwelt in unterschiedlichen Bereichen. Daneben dient die Zeitschrift als Forum zur Positionierung der F{\"a}cher J{\"u}dische Studien und ­Judaistik innerhalb des wissenschaftlichen Diskurses sowie zur Diskussion ihrer historischen und gesellschaftlichen Verantwortung.}, language = {en} } @misc{CeulemansGaedkeKlauschiesetal.2019, author = {Ceulemans, Ruben and Gaedke, Ursula and Klauschies, Toni and Guill, Christian}, title = {The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {744}, issn = {1866-8372}, doi = {10.25932/publishup-43543}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435439}, pages = {16}, year = {2019}, abstract = {Diverse communities can adjust their trait composition to altered environmental conditions, which may strongly influence their dynamics. Previous studies of trait-based models mainly considered only one or two trophic levels, whereas most natural system are at least tritrophic. Therefore, we investigated how the addition of trait variation to each trophic level influences population and community dynamics in a tritrophic model. Examining the phase relationships between species of adjacent trophic levels informs about the strength of top-down or bottom-up control in non-steadystate situations. Phase relationships within a trophic level highlight compensatory dynamical patterns between functionally different species, which are responsible for dampening the community temporal variability. Furthermore, even without trait variation, our tritrophic model always exhibits regions with two alternative states with either weak or strong nutrient exploitation, and correspondingly low or high biomass production at the top level. However, adding trait variation increased the basin of attraction of the high-production state, and decreased the likelihood of a critical transition from the high- to the lowproduction state with no apparent early warning signals. Hence, our study shows that trait variation enhances resource use efficiency, production, stability, and resilience of entire food webs.}, language = {en} } @phdthesis{Jakobs2019, author = {Jakobs, Friedrich}, title = {Dubrovin-rings and their connection to Hughes-free skew fields of fractions}, doi = {10.25932/publishup-43556}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435561}, school = {Universit{\"a}t Potsdam}, pages = {ix, 62}, year = {2019}, abstract = {One method of embedding groups into skew fields was introduced by A. I. Mal'tsev and B. H. Neumann (cf. [18, 19]). If G is an ordered group and F is a skew field, the set F((G)) of formal power series over F in G with well-ordered support forms a skew field into which the group ring F[G] can be embedded. Unfortunately it is not suficient that G is left-ordered since F((G)) is only an F-vector space in this case as there is no natural way to define a multiplication on F((G)). One way to extend the original idea onto left-ordered groups is to examine the endomorphism ring of F((G)) as explored by N. I. Dubrovin (cf. [5, 6]). It is possible to embed any crossed product ring F[G; η, σ] into the endomorphism ring of F((G)) such that each non-zero element of F[G; η, σ] defines an automorphism of F((G)) (cf. [5, 10]). Thus, the rational closure of F[G; η, σ] in the endomorphism ring of F((G)), which we will call the Dubrovin-ring of F[G; η, σ], is a potential candidate for a skew field of fractions of F[G; η, σ]. The methods of N. I. Dubrovin allowed to show that specific classes of groups can be embedded into a skew field. For example, N. I. Dubrovin contrived some special criteria, which are applicable on the universal covering group of SL(2, R). These methods have also been explored by J. Gr{\"a}ter and R. P. Sperner (cf. [10]) as well as N.H. Halimi and T. Ito (cf. [11]). Furthermore, it is of interest to know if skew fields of fractions are unique. For example, left and right Ore domains have unique skew fields of fractions (cf. [2]). This is not the general case as for example the free group with 2 generators can be embedded into non-isomorphic skew fields of fractions (cf. [12]). It seems likely that Ore domains are the most general case for which unique skew fields of fractions exist. One approach to gain uniqueness is to restrict the search to skew fields of fractions with additional properties. I. Hughes has defined skew fields of fractions of crossed product rings F[G; η, σ] with locally indicable G which fulfill a special condition. These are called Hughes-free skew fields of fractions and I. Hughes has proven that they are unique if they exist [13, 14]. This thesis will connect the ideas of N. I. Dubrovin and I. Hughes. The first chapter contains the basic terminology and concepts used in this thesis. We present methods provided by N. I. Dubrovin such as the complexity of elements in rational closures and special properties of endomorphisms of the vector space of formal power series F((G)). To combine the ideas of N.I. Dubrovin and I. Hughes we introduce Conradian left-ordered groups of maximal rank and examine their connection to locally indicable groups. Furthermore we provide notations for crossed product rings, skew fields of fractions as well as Dubrovin-rings and prove some technical statements which are used in later parts. The second chapter focuses on Hughes-free skew fields of fractions and their connection to Dubrovin-rings. For that purpose we introduce series representations to interpret elements of Hughes-free skew fields of fractions as skew formal Laurent series. This 1 Introduction allows us to prove that for Conradian left-ordered groups G of maximal rank the statement "F[G; η, σ] has a Hughes-free skew field of fractions" implies "The Dubrovin ring of F [G; η, σ] is a skew field". We will also prove the reverse and apply the results to give a new prove of Theorem 1 in [13]. Furthermore we will show how to extend injective ring homomorphisms of some crossed product rings onto their Hughes-free skew fields of fractions. At last we will be able to answer the open question whether Hughes--free skew fields are strongly Hughes-free (cf. [17, page 53]).}, language = {en} } @misc{PoradaTammRaggioetal.2019, author = {Porada, Philipp and Tamm, Alexandra and Raggio, Jose and Yafang, Cheng and Kleidon, Axel and P{\"o}schl, Ulrich and Weber, Bettina}, title = {Global NO and HONO emissions of biological soil crusts estimated by a process-based non-vascular vegetation model}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {746}, issn = {1866-8372}, doi = {10.25932/publishup-43568}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435682}, pages = {2003 -- 2031}, year = {2019}, abstract = {The reactive trace gases nitric oxide (NO) and nitrous acid (HONO) are crucial for chemical processes in the atmosphere, including the formation of ozone and OH radicals, oxidation of pollutants, and atmospheric self-cleaning. Recently, empirical studies have shown that biological soil crusts are able to emit large amounts of NO and HONO, and they may therefore play an important role in the global budget of these trace gases. However, the upscaling of local estimates to the global scale is subject to large uncertainties, due to unknown spatial distribution of crust types and their dynamic metabolic activity. Here, we perform an alternative estimate of global NO and HONO emissions by biological soil crusts, using a process-based modelling approach to these organisms, combined with global data sets of climate and land cover. We thereby consider that NO and HONO are emitted in strongly different proportions, depending on the type of crust and their dynamic activity, and we provide a first estimate of the global distribution of four different crust types. Based on this, we estimate global total values of 1.04 Tg yr⁻¹ NO-N and 0.69 Tg yr⁻¹ HONO-N released by biological soil crusts. This corresponds to around 20\% of global emissions of these trace gases from natural ecosystems. Due to the low number of observations on NO and HONO emissions suitable to validate the model, our estimates are still relatively uncertain. However, they are consistent with the amount estimated by the empirical approach, which confirms that biological soil crusts are likely to have a strong impact on global atmospheric chemistry via emissions of NO and HONO.}, language = {en} } @techreport{Devaney2019, type = {Working Paper}, author = {Devaney, James Gerard}, title = {Selecting Investment Arbitrators}, series = {KFG Working Paper Series}, journal = {KFG Working Paper Series}, number = {33}, doi = {10.25932/publishup-43579}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435797}, pages = {27}, year = {2019}, abstract = {This paper focuses on one particular issue which has arisen in the course of the ongoing debate on the reform of investor-State dispute settlement (ISDS), namely that of the appointment of arbitrators. Taking as its starting point that there now exists tentative consensus that the present system for the appointment of arbitrators either causes or exacerbates certain problematic aspects of the current ISDS system, the paper explores one option for reform, namely the introduction of an independent panel for the selection of investment arbitrators. In doing so, it is argued that a shift in the normative basis of the rules governing appointments is required in order to accommodate the principles of party autonomy and the international rule of law. Such reform, while not completely removing the initiative that parties presently enjoy, is the most efficient way to introduce rule of law considerations such as a measure of judicial independence into the current appointments system. This, it is argued, would in turn help to address some of the problematic features of the appointment of arbitrators in ISDS.}, language = {en} } @techreport{KriegerPueschmann2019, type = {Working Paper}, author = {Krieger, Heike and P{\"u}schmann, Jonas}, title = {Securing of Resources as a Valid Reason for Using Force?}, series = {KFG Working Paper Series}, journal = {KFG Working Paper Series}, number = {31}, doi = {10.25932/publishup-43573}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435738}, pages = {24}, year = {2019}, abstract = {A growing demand for natural resources embedded in current changes of the international order will put pressure on states to secure the future availability of these resources. Some political discourses suggest that states might respond by challenging the foundations of international law. Whereas the UN Charter was inter alia aimed at eliminating uses of force for economic reasons, one may observe an on-going trend of securitization of matters of resource supply resulting into the revival of self-preservation doctrines. The chapter will show that those claims lack a normative foundation in the current framework of the prohibition of the use of force. Moreover, international law has sufficient instruments to cope with disputes over access to resources by other means than the use of force. The international community, therefore, must oppose claims that may contribute to normative uncertainties and strengthen already existing instruments of pacific settlement of disputes.}, language = {en} } @techreport{Kulaga2019, type = {Working Paper}, author = {Kulaga, Julian}, title = {A Renaissance of the Doctrine of Rebus Sic Stantibus?}, series = {KFG Working Paper Series}, journal = {KFG Working Paper Series}, number = {32}, doi = {10.25932/publishup-43578}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435788}, pages = {21}, year = {2019}, abstract = {Once the "popular plaything of Realpolitiker" the doctrine of rebus sic stantibus post the 1969 VCLT is often described as an objective rule by which, on grounds of equity and justice, a fundamental change of circumstances may be invoked as a ground for termination. Yet recent practice from States such as Ecuador, Russia, Denmark and the United Kingdom suggests that it is returning with a new livery. They point to an understanding based on vital States' interests--a view popular among scholars such as Erich Kaufmann at the beginning of the last century.}, language = {en} }