@phdthesis{Schubert2015,
  author    = {Schubert, Tobias},
  title     = {Der Kampf um das digitalisierte Breitbandkabel},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77662},
  school      = {Universit{\"a}t Potsdam},
  pages     = {356},
  year      = {2015},
  abstract  = {Der klassische Fernsehrundfunk genießt verfassungsrechtlich und einfachgesetzliche eine privilegierte Sonderstellung. Diese setzt sich bei der Kabelbelegung fort, wo er - insbesondere der {\"o}ffentliche Rundfunk - gegen{\"u}ber teemedialen Anrufangeboten bevorrechtigt wird. Hintergrund dieser Sonderstellung ist nicht zuletzt die auf den Rundfunk zentrierte Medienordnung. Die Arbeit untersucht, ob diese Medienordnung und damit die Sonderstellung des Rundfunks noch zeitgem{\"a}ß ist und schl{\"a}gt Anpassungen vor.},
  language  = {de}
}
@phdthesis{Rajasundaram2015,
  author    = {Rajasundaram, Dhivyaa},
  title     = {Integrative analysis of heterogeneous plant cell wall related data},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77652},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 205},
  year      = {2015},
  abstract  = {Plant cell walls are complex structures that underpin plant growth and are widely exploited in diverse human activities thus placing them with a central importance in biology. Cell walls have been a prominent area of research for a long time, but the chemical complexity and diversity of cell walls not just between species, but also within plants, between cell-types, and between cell wall micro-domains pose several challenges. Progress accelerated several-fold in cell wall biology owing to advances in sequencing technology, aided soon thereafter by advances in omics and imaging technologies. This development provides additional perspectives of cell walls across a rapidly growing number of species, highlighting a myriad of architectures, compositions, and functions. Furthermore, rather than the component centric view, integrative analysis of the different cell wall components across system-levels help to gain a more in-depth understanding of the structure and biosynthesis of the cell envelope and its interactions with the environment. To this end, in this work three case studies are detailed, all pertaining to the integrative analysis of heterogeneous cell wall related data arising from different system-levels and analytical techniques. A detailed account of multiblock methods is provided and in particular canonical correlation and regression methods of data integration are discussed. In the first integrative analysis, by employing canonical correlation analysis - a multivariate statistical technique to study the association between two datasets - novel insight to the relationship between glycans and phenotypic traits is gained. In addition, sparse partial least squares regression approach that adapts Lasso penalization and allows for the selection of a subset of variables was employed. The second case study focuses on an integrative analysis of images obtained from different spectroscopic techniques. By employing yet another multiblock approach - multiple co-inertia analysis, insitu biochemical composition of cell walls from different cell-types is studied thereby highlighting the common and complementary parts of the two hyperspectral imaging techniques. Finally, the third integrative analysis facilitates gene expression analysis of the Arabidopsis root transcriptome and translatome for the identification of cell wall related genes and compare expression patterns of cell wall synthesis genes. The computational analysis considered correlation and variation of expression across cell-types at both system-levels, and also provides insight into the degree of co-regulatory relationships that are preserved between the two processes. The integrative analysis of glycan data and phenotypic traits in cotton fibers using canonical methods led to the identification of specific polysaccharides which may play a major role during fiber development for the final fiber characteristics. Furthermore, this analysis provides a base for future studies on glycan arrays in case of developing cotton fibers. The integrative analysis of images from infrared and Raman spectroscopic approaches allowed the coupling of different analytical techniques to characterize complex biological material, thereby, representing various facets of their chemical properties. Moreover, the results from the co-inertia analysis demonstrated that the study was well adapted as it is relevant for coupling data tables in a symmetric way. Several indicators are proposed to investigate how the global and block scores are related. In addition, studying the root cells of \textit{Arabidopsis thaliana} allowed positing a novel pipeline to systematically investigate and integrate the different levels of information available at the global and single-cell level. The conducted analysis also confirms that previously identified key transcriptional activators of secondary cell wall development display highly conserved patterns of transcription and translation across the investigated cell-types. Moreover, the biological processes that display conserved and divergent patterns based on the cell-type-specific expression and translation levels are identified.},
  language  = {en}
}
@phdthesis{Duemke2015,
  author    = {D{\"u}mke, Christian},
  title     = {Daseinsvorsorge, Wettbewerb und kommunale Selbstverwaltung im Bereich der liberalisierten Energiewirtschaft},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-314-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73914},
  school      = {Universit{\"a}t Potsdam},
  pages     = {175},
  year      = {2015},
  abstract  = {Die Arbeit befasst sich zun{\"a}chst mit der Analyse und Einordnung des Begriffs der Daseinsvorsorge und deren Erbringung durch den Staat. Schwerpunkt der Betrachtung bildet dabei die Energieversorgung als klassische Aufgabe staatlicher Daseinsvorsorge. Weiterhin wird der durch die Liberalisierung der Energieversorgung im Jahr 1998 eingeleitete Wandel von sog. nat{\"u}rlichen Monopolen, hin zu einem wettbewerblichen System betrachtet. Dabei wird aufgezeigt, dass sich durch die Einf{\"u}hrung des Wettbewerbs weder die damit erhofften Kostenreduzierungen, noch das von Kritikern bef{\"u}rchtete Sterben der kommunalen Energieversorger bewahrheitet haben. Statt einer freien Preisbildung im Wettbewerb ist es zu einer faktischen Verlagerung der fr{\"u}her staatlich festgesetzten Energiepreisgenehmigung auf die Gerichte gekommen, die hierf{\"u}r jedoch nicht ausgelegt sind. Kommunale Stadtwerke haben sich in der wettbewerblichen Energieversorgung dagegen so gut behauptet, dass seit einiger Zeit ein Trend zur Rekommunalisierung von Energieversorgung auf kommunaler Ebene zu verzeichnen ist. Diesem offensichtlichen Wunsch nach einer gesteigerten Einflussnahme der Gemeinden auf die {\"o}rtliche Energieversorgung l{\"a}uft der aktuelle Rechtsrahmen der energierechtlichen Konzessionsvergabe in Gestalt des \S 46 EnWG und seiner Auslegung durch die Rechtsprechung der Zivilgerichte zuwider. Die Arbeit zeigt auf, dass von Beginn der Liberalisierung der kommunale Einfluss auf die {\"o}rtliche Konzessionsvergabe schrittweise und stetig beschnitten wurde, so dass gegenw{\"a}rtig ein Zustand der Aush{\"o}hlung erreicht ist, der als unzul{\"a}ssiger Eingriff in den gesch{\"u}tzten Kernbereich der kommunalen Selbstverwaltungsgarantie i.S.d. Art. 28 II GG anzusehen ist.},
  language  = {de}
}
@phdthesis{Busch2015,
  author    = {Busch, Jan Philip},
  title     = {Investigations on mobility of carbon colloid supported nanoscale zero-valent iron (nZVI) for groundwater remediation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-76873},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 127, XLIII},
  year      = {2015},
  abstract  = {Injection of nanoscale zero-valent iron (nZVI) is an innovative technology for in situ installation of a permeable reactive barrier in the subsurface. Zerovalent iron (ZVI) is highly reactive with chlorinated hydrocarbons (CHCs) and renders them into less harmful substances. Application of nZVI instead of granular ZVI can increase rates of dechlorination of CHCs by orders of magnitude, due to its higher surface area. This approach is still difficult to apply due to fast agglomeration and sedimentation of colloidal suspensions of nZVI, which leads to very short transport distances. To overcome this issue of limited mobility, polyanionic stabilisers are added to increase surface charge and stability of suspensions. In field experiments maximum transport distances of a few metres were achieved. A new approach, which is investigated in this thesis, is enhanced mobility of nZVI by a more mobile carrier colloid. The investigated composite material consists of activated carbon, which is loaded with nZVI. In this cumulative thesis, transport characteristics of carbon-colloid supported nZVI (c-nZVI) are investigated. Investigations started with column experiments in 40 cm columns filled with various porous media to investigate on physicochemical influences on transport characteristics. The experimental setup was enlarged to a transport experiment in a 1.2-m-sized two-dimensional aquifer tank experiment, which was filled with granular porous media. Further, a field experiment was performed in a natural aquifer system with a targeted transport distance of 5.3 m. Parallel to these investigations, alternative methods for transport observations were investigated by using noninvasive tomographic methods. Experiments using synchrotron radiation and magnetic resonance (MRI) were performed to investigate in situ transport characteristics in a non-destructive way. Results from column experiments show potentially high mobility under environmental relevant conditions. Addition of mono-and bivalent salts, e.g. more than 0.5 mM/L CaCl2, might decrease mobility. Changes in pH to values below 6 can inhibit mobility at all. Measurements of colloid size show changes in the mean particle size by a factor of ten. Measurements of zeta potential revealed an increase of -62 mV to -82 mV. Results from the 2D-aquifer test system suggest strong particle deposition in the first centimetres and only weak straining in the further travel path and no gravitational influence on particle transport. Straining at the beginning of the travel path in the porous medium was observed with tomographic investigations of transport. MRI experiments revealed similar results to the previous experiments, and observations using synchrotron radiation suggest straining of colloids at pore throats. The potential for high transport distances, which was suggested from laboratory experiments, was confirmed in the field experiment, where the transport distance of 5.3 m was reached by at least 10\% of injected nZVI. Altogether, transport distances of the investigated carbon-colloid supported nZVI are higher than published results of traditional nZVI.},
  language  = {en}
}
@phdthesis{Gerth2015,
  author    = {Gerth, Sabrina},
  title     = {Memory limitations in sentence comprehension},
  isbn      = {978-3-86956-321-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-71554},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xviii, 157},
  year      = {2015},
  abstract  = {This dissertation addresses the question of how linguistic structures can be represented in working memory. We propose a memory-based computational model that derives offline and online complexity profiles in terms of a top-down parser for minimalist grammars (Stabler, 2011). The complexity metric reflects the amount of time an item is stored in memory. The presented architecture links grammatical representations stored in memory directly to the cognitive behavior by deriving predictions about sentence processing difficulty. Results from five different sentence comprehension experiments were used to evaluate the model's assumptions about memory limitations. The predictions of the complexity metric were compared to the locality (integration and storage) cost metric of Dependency Locality Theory (Gibson, 2000). Both metrics make comparable offline and online predictions for four of the five phenomena. The key difference between the two metrics is that the proposed complexity metric accounts for the structural complexity of intervening material. In contrast, DLT's integration cost metric considers the number of discourse referents, not the syntactic structural complexity. We conclude that the syntactic analysis plays a significant role in memory requirements of parsing. An incremental top-down parser based on a grammar formalism easily computes offline and online complexity profiles, which can be used to derive predictions about sentence processing difficulty.},
  language  = {en}
}
@phdthesis{Wieland2015,
  author    = {Wieland, Volkmar},
  title     = {Particle-in-cell simulations of perpendicular supernova shock fronts},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74532},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 89},
  year      = {2015},
  abstract  = {The origin of cosmic rays was the subject of several studies for over a century. The investigations done within this dissertation are one small step to shed some more light on this mystery. Locating the sources of cosmic rays is not trivial due to the interstellar magnetic field. However, the Hillas criterion allows us to arrive at the conclusion that supernova remnants are our main suspect for the origin of galactic cosmic rays. The mechanism by which they are accelerating particles is found within the field of shock physics as diffusive shock acceleration. To allow particles to enter this process also known as Fermi acceleration pre-acceleration processes like shock surfing acceleration and shock drift acceleration are necessary. Investigating the processes happening in the plasma shocks of supernova remnants is possible by utilising a simplified model which can be simulated on a computer using Particle-in-Cell simulations. We developed a new and clean setup to simulate the formation of a double shock, i.e., consisting of a forward and a reverse shock and a contact discontinuity, by the collision of two counter-streaming plasmas, in which a magnetic field can be woven into. In a previous work, we investigated the processes at unmagnetised and at magnetised parallel shocks, whereas in the current work, we move our investigation on to magnetised perpendicular shocks. Due to a much stronger confinement of the particles to the collision region the perpendicular shock develops much faster than the parallel shock. On the other hand, this leads to much weaker turbulence. We are able to find indications for shock surfing acceleration and shock drift acceleration happening at the two shocks leading to populations of pre-accelerated particles that are suitable as a seed population to be injected into further diffusive shock acceleration to be accelerated to even higher energies. We observe the development of filamentary structures in the shock ramp of the forward shock, but not at the reverse shock. This leads to the conclusion that the development of such structures in the shock ramp of quasi-perpendicular collisionless shocks might not necessarily be determined by the existence of a critical sonic Mach number but by a critical shock speed. The results of the investigations done within this dissertation might be useful for further studies of oblique shocks and for studies using hybrid or magnetohydrodynamic simulations. Together with more sophisticated observational methods, these studies will help to bring us closer to an answer as to how particles can be accelerated in supernova remnants and eventually become cosmic rays that can be detected on Earth.},
  language  = {en}
}
@phdthesis{Schirmack2015,
  author    = {Schirmack, Janosch},
  title     = {Activity of methanogenic archaea under simulated Mars analog conditions},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73010},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VI, 108},
  year      = {2015},
  abstract  = {Assumed comparable environmental conditions of early Mars and early Earth in 3.7 Ga ago - at a time when first fossil records of life on Earth could be found - suggest the possibility of life emerging on both planets in parallel. As conditions changed, the hypothetical life on Mars either became extinct or was able to adapt and might still exist in biological niches. The controversial discussed detection of methane on Mars led to the assumption, that it must have a recent origin - either abiotic through active volcanism or chemical processes, or through biogenic production. Spatial and seasonal variations in the detected methane concentrations and correlations between the presence of water vapor and geological features such as subsurface hydrogen, which are occurring together with locally increased detected concentrations of methane, gave fuel to the hypothesis of a possible biological source of the methane on Mars. Therefore the phylogenetically old methanogenic archaea, which have evolved under early Earth conditions, are often used as model-organisms in astrobiological studies to investigate the potential of life to exist in possible extraterrestrial habitats on our neighboring planet. In this thesis methanogenic archaea originating from two extreme environments on Earth were investigated to test their ability to be active under simulated Mars analog conditions. These extreme environments - the Siberian permafrost-affected soil and the chemoautotrophically based terrestrial ecosystem of Movile cave, Romania - are regarded as analogs for possible Martian (subsurface) habitats. Two novel species of methanogenic archaea isolated from these environments were described within the frame of this thesis. It could be shown that concentrations up to 1 wt\% of Mars regolith analogs added to the growth media had a positive influence on the methane production rates of the tested methanogenic archaea, whereas higher concentrations resulted in decreasing rates. Nevertheless it was possible for the organisms to metabolize when incubated on water-saturated soil matrixes made of Mars regolith analogs without any additional nutrients. Long-term desiccation resistance of more than 400 days was proven with reincubation and indirect counting of viable cells through a combined treatment with propidium monoazide (to inactivate DNA of destroyed cells) and quantitative PCR. Phyllosilicate rich regolith analogs seem to be the best soil mixtures for the tested methanogenic archaea to be active under Mars analog conditions. Furthermore, in a simulation chamber experiment the activity of the permafrost methanogen strain Methanosarcina soligelidi SMA-21 under Mars subsurface analog conditions could be proven. Through real-time wavelength modulation spectroscopy measurements the increase in the methane concentration at temperatures down to -5 °C could be detected. The results presented in this thesis contribute to the understanding of the activity potential of methanogenic archaea under Mars analog conditions and therefore provide insights to the possible habitability of present-day Mars (near) subsurface environments. Thus, it contributes also to the data interpretation of future life detection missions on that planet. For example the ExoMars mission of the European Space Agency (ESA) and Roscosmos which is planned to be launched in 2018 and is aiming to drill in the Martian subsurface.},
  language  = {en}
}
@phdthesis{Friedmann2015,
  author    = {Friedmann, Ronald},
  title     = {Arthur Ewert (1890-1959)},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73024},
  school      = {Universit{\"a}t Potsdam},
  pages     = {485},
  year      = {2015},
  abstract  = {Arthur Ewert (1890-1959) war in den zwanziger und fr{\"u}hen dreißiger Jahren ein wichtiger Funktion{\"a}r der Kommunistischen Partei Deutschlands und der Kommunistischen Internationale. Er wurde in der Familie eines armen Bauern in Ostpreußen geboren. Nach dem Abschluß der Schule ging er nach Berlin, um hier eine Lehre als Sattler zu absolvieren. {\"U}ber die Berliner Arbeiterjugendbewegung fand er Kontakt zur Sozialdemokratischen Partei Deutschlands, deren Mitglied er 1908 wurde. Im Mai 1914 emigrierte er gemeinsam mit seiner langj{\"a}hrigen Lebensgef{\"a}hrtin und sp{\"a}teren Ehefrau Elise Saborowski (1886-1939) nach Nordamerika, wo er sich sofort der sozialistischen Bewegung anschloß. Anfang 1919 geh{\"o}rte er zu den Mitbegr{\"u}ndern der ersten Kommunistischen Partei Kanadas. Im Sommer 1919 kehrte er nach Deutschland zur{\"u}ck und wurde Mitglied der wenige Monate zuvor gegr{\"u}ndeten KPD. Auf dem Leipziger Parteitag der KPD im Februar 1923 wurde er in die zwanzigk{\"o}pfige Zentrale seiner Partei gew{\"a}hlt und stieg damit in den engeren F{\"u}hrungszirkel auf. Nach der gescheiterten »Deutschen Oktoberrevolution« im Herbst 1923 k{\"a}mpfte er gemeinsam mit Ernst Meyer, Hugo Eberlein, Wilhelm Pieck und anderen um das {\"U}berleben der KPD, doch gelang es seiner Gruppe nicht, den Sieg der Linken und Ultralinken im parteiinternen Machtkampf zu verhindern. Ewert wurde politisch »kaltgestellt« und schied f{\"u}r mehr als ein Jahr aus der Parteif{\"u}hrung aus. In dieser Zeit erf{\"u}llte er verschiedene Aufgaben f{\"u}r die Kommunistische Internationale. Bereits im Juni 1923 war er Berichterstatter zur Lage in der Norwegischen Arbeiterpartei gewesen, ab Ende 1924 war er Abgesandter bei der KP Großbritanniens. Im Sommer und Fr{\"u}hherbst 1927 hielt er sich mehrere Monate in den USA auf. Im Sommer 1925 wurde er auf Veranlassung der Kommunistischen Internationale in die F{\"u}hrung der KPD zur{\"u}ckgeholt. Er trug wesentlich dazu bei, die Parteif{\"u}hrung unter Ernst Th{\"a}lmann zu stabilisieren und sie - zumindest zeitweise - auf einen realpolitischen Kurs zu orientieren. Mit dem erneuten »Links«-Schwenk der KPD ab Anfang 1928 wurde er als »Vers{\"o}hnler« stigmatisiert und zunehmend zur Zielscheibe innerparteilicher Attacken. Der Versuch eines »Befreiungsschlages« unter Ausnutzung der sogenannten Wittorf-Aff{\"a}re im Herbst 1928 scheiterte, bis zum Sommer 1929 wurde Arthur Ewert auf Dr{\"a}ngen Stalins und mit ausdr{\"u}cklicher Zustimmung Th{\"a}lmanns aus allen Funktionen in der KPD entfernt. Nach der Aufl{\"o}sung des Reichstags und dem damit verbundenen Verlust seines Reichstagsmandats im Juli 1930 schied Ewert endg{\"u}ltig aus der deutschen Parteiarbeit aus. Ende 1930 wurde er zum Leiter des S{\"u}damerikanischen B{\"u}ros der Kommunistischen Internationale in Montevideo, der Hauptstadt Uruguays, ernannt. Er trug damit Verantwortung f{\"u}r die unmittelbare Anleitung der Kommunistischen Parteien im sogenannten S{\"u}dkegel S{\"u}damerikas. In diese Zeit fielen seine ersten Kontakte zu Luiz Carlos Prestes, dem legend{\"a}ren »Ritter der Hoffnung«, mit dem er ab Anfang 1935 in Brasilien zusammenarbeitete. Von 1932 bis 1934 leitete Arthur Ewert das B{\"u}ro der Kommunistischen Internationale in Shanghai und spielte dabei eine entscheidende Rolle zugunsten Mao Tse-tungs, dessen politisches {\"U}berleben er in einem innerparteilichen Machtkampf der KP Chinas sicherte. Als Vertreter der Kommunistischen Internationale war Arthur Ewert im Verlaufe des Jahres 1935 an den Versuchen beteiligt, in Brasilien - gest{\"u}tzt auf ein breites B{\"u}ndnis, die »Nationale Befreiungsallianz« - einen politischen Machtwechsel herbeizuf{\"u}hren. Nach dem Scheitern des von Prestes gef{\"u}hrten Aufstandsversuches wurde er Ende 1935 verhaftet. Arthur Ewert verlor in Folge der barbarischen Folterungen in brasilianischer Haft den Verstand. Er kam im Mai 1945 im Ergebnis einer Amnestie frei. 1947 gelang es seiner Schwester, ihn in die sowjetische Besatzungszone zur{\"u}ckzuholen. Die {\"A}rzte dort konnten nur noch feststellen, daß eine Heilung unm{\"o}glich war. Arthur Ewert verbrachte den Rest seines Lebens in einem Pflegeheim in Eberswalde, wo er 1959 starb.},
  language  = {de}
}