@phdthesis{Bettenbuehl2015,
  author    = {Bettenb{\"u}hl, Mario},
  title     = {Microsaccades},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-122-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72622},
  school      = {Universit{\"a}t Potsdam},
  pages     = {iv, 126},
  year      = {2015},
  abstract  = {The first thing we do upon waking is open our eyes. Rotating them in our eye sockets, we scan our surroundings and collect the information into a picture in our head. Eye movements can be split into saccades and fixational eye movements, which occur when we attempt to fixate our gaze. The latter consists of microsaccades, drift and tremor. Before we even lift our eye lids, eye movements - such as saccades and microsaccades that let the eyes jump from one to another position - have partially been prepared in the brain stem. Saccades and microsaccades are often assumed to be generated by the same mechanisms. But how saccades and microsaccades can be classified according to shape has not yet been reported in a statistical manner. Research has put more effort into the investigations of microsaccades' properties and generation only since the last decade. Consequently, we are only beginning to understand the dynamic processes governing microsaccadic eye movements. Within this thesis, the dynamics governing the generation of microsaccades is assessed and the development of a model for the underlying processes. Eye movement trajectories from different experiments are used, recorded with a video-based eye tracking technique, and a novel method is proposed for the scale-invariant detection of saccades (events of large amplitude) and microsaccades (events of small amplitude). Using a time-frequency approach, the method is examined with different experiments and validated against simulated data. A shape model is suggested that allows for a simple estimation of saccade- and microsaccade related properties. For sequences of microsaccades, in this thesis a time-dynamic Markov model is proposed, with a memory horizon that changes over time and which can best describe sequences of microsaccades.},
  language  = {en}
}
@phdthesis{Doerge2015,
  author    = {D{\"o}rge, Christina},
  title     = {Informatische Schl{\"u}sselkompetenzen},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-262-9},
  issn      = {1868-0844},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-70470},
  school      = {Universit{\"a}t Potsdam},
  pages     = {458},
  year      = {2015},
  abstract  = {Seit den 60er Jahren gibt es im deutschsprachigen Raum Diskussionen um die Begriffe Schl{\"u}sselqualifikation und (Schl{\"u}ssel-)Kompetenz, welche seit ca. 2000 auch in der Informatikdidaktik angekommen sind. Die Diskussionen der Fachdisziplinen und ihre Bedeutung f{\"u}r die Informatikdidaktik sind Gegenstand des ersten Teils dieser Dissertation. Es werden Rahmenmodelle zur Strukturierung und Einordnung von Kompetenzen entworfen, die f{\"u}r alle Fachdisziplinen nutzbar sind. Im zweiten Teil wird ein methodologischer Weg gezeigt, Schl{\"u}sselkompetenzen herzuleiten, ohne normativ vorgehen zu m{\"u}ssen. Hierzu wird das Verfahren der Qualitativen Inhaltsanalyse (QI) auf informatikdidaktische Ansätze angewendet. Die resultierenden Kompetenzen werden in weiteren Schritten verfeinert und in die zuvor entworfenen Rahmenmodelle eingeordnet. Das Ergebnis sind informatische Schl{\"u}sselkompetenzen, welche ein spezifisches Bild der Informatik zeichnen und zur Analyse bereits bestehender Curricula genutzt werden können. Zusätzlich zeigt das Verfahren einen Weg auf, wie Schl{\"u}sselkompetenzen auf nicht-normativem Wege generell hergeleitet werden können.},
  language  = {de}
}
@phdthesis{Lamanna2015,
  author    = {Lamanna, Francesco},
  title     = {Adaptive radiation and speciation in African weakly-electric fish},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80097},
  school      = {Universit{\"a}t Potsdam},
  pages     = {114},
  year      = {2015},
  abstract  = {The rise of evolutionary novelties is one of the major drivers of evolutionary diversification. African weakly-electric fishes (Teleostei, Mormyridae) have undergone an outstanding adaptive radiation, putatively owing to their ability to communicate through species-specific Electric Organ Discharges (EODs) produced by a novel, muscle-derived electric organ. Indeed, such EODs might have acted as effective pre-zygotic isolation mechanisms, hence favoring ecological speciation in this group of fishes. Despite the evolutionary importance of this organ, genetic investigations regarding its origin and function have remained limited. The ultimate aim of this study is to better understand the genetic basis of EOD production by exploring the transcriptomic profiles of the electric organ and of its ancestral counterpart, the skeletal muscle, in the genus Campylomormyrus. After having established a set of reference transcriptomes using "Next-Generation Sequencing" (NGS) technologies, I performed in silico analyses of differential expression, in order to identify sets of genes that might be responsible for the functional differences observed between these two kinds of tissues. The results of such analyses indicate that: i) the loss of contractile activity and the decoupling of the excitation-contraction processes are reflected by the down-regulation of the corresponding genes in the electric organ; ii) the metabolic activity of the electric organ might be specialized towards the production and turnover of membrane structures; iii) several ion channels are highly expressed in the electric organ in order to increase excitability, and iv) several myogenic factors might be down-regulated by transcription repressors in the EO. A secondary task of this study is to improve the genus level phylogeny of Campylomormyrus by applying new methods of inference based on the multispecies coalescent model, in order to reduce the conflict among gene trees and to reconstruct a phylogenetic tree as closest as possible to the actual species-tree. By using 1 mitochondrial and 4 nuclear markers, I was able to resolve the phylogenetic relationships among most of the currently described Campylomormyrus species. Additionally, I applied several coalescent-based species delimitation methods, in order to test the hypothesis that putatively cryptic species, which are distinguishable only from their EOD, belong to independently evolving lineages. The results of this analysis were additionally validated by investigating patterns of diversification at 16 microsatellite loci. The results suggest the presence of a new, yet undescribed species of Campylomormyrus.},
  language  = {en}
}
@phdthesis{Borschewski2015,
  author    = {Borschewski, Aljona},
  title     = {Bedeutung der Interaktion von Calcineurin und SORLA f{\"u}r die Regulation des Na⁺,K⁺,2Cl⁻-Kotransporters (NKCC2) in der Niere},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89205},
  school      = {Universit{\"a}t Potsdam},
  pages     = {II, 86},
  year      = {2015},
  abstract  = {Der Na⁺-K⁺-2Cl⁻-Kotransporter (NKCC2) wird im distalen Nephron der Niere exprimiert. Seine Verteilung umfasst die Epithelien der medull{\"a}ren und kortikalen Teile der dicken aufsteigenden Henle-Schleife (Thick ascending limb, TAL) und die Macula densa. Resorptiver NaCl-Transport {\"u}ber den NKCC2 dient dem renalen Konzentrierungsmechanismus und reguliert systemisch auch Volumenstatus und Blutdruck. Die Aktivit{\"a}t des NKCC2 ist mit der Phosphorylierung seiner N-terminalen Aminos{\"a}urereste Serin 126 und Threonin 96/101 verbunden. Vermittelt wird diese durch die homologen Kinasen SPAK (SPS-related proline/alanine-rich kinase) und OSR1 (Oxidative stress responsive kinase 1), die hierzu ihrerseits phosphoryliert werden m{\"u}ssen. Der regulatorische Kontext dieser Kinasen ist mittlerweile gut charakterisiert. {\"U}ber Mechanismen und Produkte, die den NKCC2 deaktivieren, war hingegen weniger bekannt. Ziel der Arbeit war daher zu untersuchen, welche Wege zur Deaktivierung des Transporters f{\"u}hren. Der intrazellul{\"a}re Sortierungsrezeptor SORLA (Sorting-protein-related receptor with A-type repeats) war zuvor in seiner Bedeutung f{\"u}r das Nephron charakterisiert worden. Ein SORLA-defizientes Mausmodell weist unter anderem eine stark verringerte NKCC2-Phosphorylierung auf. Unter osmotischem Stress k{\"o}nnen SORLA-defiziente M{\"a}use ihren Urin weniger effizient konzentrieren. Meine Resultate zeigen mit hochaufl{\"o}sender Technik, dass SORLA apikal im TAL lokalisiert ist und dass mit NKCC2 eine anteilige Kolokalisation besteht. Unter SORLA Defizienz war die f{\"u}r die NKCC2 Aktivit{\"a}t maßgebliche SPAK/OSR1-Phosphorylierung gegen{\"u}ber dem Wildtyp nicht ver{\"a}ndert. Jedoch war die ebenfalls im TAL exprimierte Phosphatase Calcineurin Aβ (CnAβ) per Western blot um das zweifache gesteigert. Parallel hierzu wurde immunhistochemisch die Kolokalisation von verst{\"a}rktem CnAβ-Signal und NKCC2 best{\"a}tigt. Beide Befunde geben zusammen den Hinweis auf einen Bezug zwischen der reduzierten NKCC2-Phosphorylierung und der gesteigerten Pr{\"a}senz von CnAβ bei SORLA Defizienz. Die parallel induzierte {\"U}berexpression von SORLA in HEK-Zellen zeigte entsprechend eine Halbierung der CnAβ Proteinmenge. SORLA steuert demzufolge sowohl die Abundanz als auch die zellul{\"a}re Verteilung der Phosphatase. Weiterhin ließ sich die Interaktion zwischen CnAβ und SORLA (intrazellul{\"a}re Dom{\"a}ne) mittels Co-Immunpr{\"a}zipitation bzw. GST-pulldown assay nachweisen. Auch die Interaktion zwischen CnAβ und NKCC2 wurde auf diesem Weg belegt. Da allerdings weder SORLA noch NKCC2 ein spezifisches Bindungsmuster f{\"u}r CnAβ aufweisen, sind vermutlich intermedi{\"a}re Adapterproteine bei ihrer Bindung involviert. Die pharmakologische Inhibition von CnAβ mittels Cyclosporin A (CsA; 1 h) f{\"u}hrte bei SORLA Defizienz zur Normalisierung der NKCC2-Phosphorylierung. Entsprechend f{\"u}hrte in vitro die Gabe von CsA bei TAL Zellen zu einer 7-fach gesteigerten NKCC2-Phosphorylierung. Zusammenfassend zeigen die Ergebnisse, dass die Phosphatase CnAβ {\"u}ber ihre Assoziation mit NKCC2 diesen im adluminalen Zellkompartiment deaktivieren kann. Gesteuert wird dieser Vorgang durch die Eigenschaft von SORLA, CnAβ apikal zu reduzieren und damit die adluminale Phosphorylierung und Aktivit{\"a}t von NKCC2 zu unterst{\"u}tzen. Da Calcineurin-Inhibitoren derzeit die Grundlage der immunsupprimierenden Therapie darstellen, haben die Ergebnisse eine klinische Relevanz. Angesichts der Co-Expression von SORLA und CnAβ in verschiedenen anderen Organen k{\"o}nnen die Ergebnisse auch {\"u}ber die Niere hinaus Bedeutung erlangen.},
  language  = {de}
}
@phdthesis{Olszewska2015,
  author    = {Olszewska, Agata},
  title     = {Forming magnetic chain with the help of biological organisms},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89767},
  school      = {Universit{\"a}t Potsdam},
  pages     = {101},
  year      = {2015},
  abstract  = {Magnetite nanoparticles and their assembly comprise a new area of development for new technologies. The magnetic particles can interact and assemble in chains or networks. Magnetotactic bacteria are one of the most interesting microorganisms, in which the assembly of nanoparticles occurs. These microorganisms are a heterogeneous group of gram negative prokaryotes, which all show the production of special magnetic organelles called magnetosomes, consisting of a magnetic nanoparticle, either magnetite (Fe3O4) or greigite (Fe3S4), embedded in a membrane. The chain is assembled along an actin-like scaffold made of MamK protein, which makes the magnetosomes to arrange in mechanically stable chains. The chains work as a compass needle in order to allow cells to orient and swim along the magnetic field of the Earth. The formation of magnetosomes is known to be controlled at the molecular level. The physico-chemical conditions of the surrounding environment also influence biomineralization. The work presented in this manuscript aims to understand how such external conditions, in particular the extracellular oxidation reduction potential (ORP) influence magnetite formation in the strain Magnetospirillum magneticum AMB-1. A controlled cultivation of the microorganism was developed in a bioreactor and the formation of magnetosomes was characterized. Different techniques have been applied in order to characterize the amount of iron taken up by the bacteria and in consequence the size of magnetosomes produced at different ORP conditions. By comparison of iron uptake, morphology of bacteria, size and amount of magnetosomes per cell at different ORP, the formation of magnetosomes was inhibited at ORP 0 mV, whereas reduced conditions, ORP - 500 mV facilitate biomineralization process. Self-assembly of magnetosomes occurring in magnetotactic bacteria became an inspiration to learn from nature and to construct nanoparticles assemblies by using the bacteriophage M13 as a template. The M13 bacteriophage is an 800 nm long filament with encapsulated single-stranded DNA that has been recently used as a scaffold for nanoparticle assembly. I constructed two types of assemblies based on bacteriophages and magnetic nanoparticles. A chain - like assembly was first formed where magnetite nanoparticles are attached along the phage filament. A sperm - like construct was also built with a magnetic head and a tail formed by phage filament. The controlled assembly of magnetite nanoparticles on the phage template was possible due to two different mechanism of nanoparticle assembly. The first one was based on the electrostatic interactions between positively charged polyethylenimine coated magnetite nanoparticles and negatively charged phages. The second phage -nanoparticle assembly was achieved by bioengineered recognition sites. A mCherry protein is displayed on the phage and is was used as a linker to a red binding nanobody (RBP) that is fused to the one of the proteins surrounding the magnetite crystal of a magnetosome. Both assemblies were actuated in water by an external magnetic field showing their swimming behavior and potentially enabling further usage of such structures for medical applications. The speed of the phage - nanoparticles assemblies are relatively slow when compared to those of microswimmers previously published. However, only the largest phage-magnetite assemblies could be imaged and it is therefore still unclear how fast these structures can be in their smaller version.},
  language  = {en}
}
@phdthesis{Buss2015,
  author    = {Buß, Claudia},
  title     = {Instrumente der B{\"u}rgerbeteiligung in St{\"a}dten},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88888},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xi, 468},
  year      = {2015},
  abstract  = {Die vergleichende Arbeit besch{\"a}ftigt sich mit der B{\"u}rgerbeteiligung in St{\"a}dten in Deutschland und Frankreich. In den letzten 20 Jahren haben sich die Formen lokaler Demokratie immer wieder ver{\"a}ndert und sich den {\"o}rtlichen Gegebenheiten angepasst. Das Interesse der B{\"u}rger, Verwaltung und politisch gew{\"a}hlten Vertreter an Partizipation w{\"a}chst stetig . Das heißt aber auch, dass sich diese 3 Akteure den neuen Strukturen anpassen und eigene Strategien entwickeln m{\"u}ssen. Die demokratischen Formen der kooperativen bzw. partizipativen Demokratie werden immer h{\"a}ufiger angewandt. Diese Arbeit evaluiert die verschiedenen B{\"u}rgerbeteiligungsinstrumente in Frankreich und Deutschland in dem zwischen Input, Output und Outcome unterschieden wird. Insbesondere die B{\"u}rgerhaushalte, Beir{\"a}te und Quartiersr{\"a}te werden genauer betrachtet. Die Ergebnisse zeigen erste Hinweise in welche demokratische Richtung sich die deutschen St{\"a}dte k{\"u}nftig entwickeln.},
  language  = {de}
}
@phdthesis{Ayguel2015,
  author    = {Ayg{\"u}l, Mesut},
  title     = {Pre-collisional accretion and exhumation along the southern Laurasian active margin, Central Pontides, Turkey},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416769},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxxiv, 206},
  year      = {2015},
  abstract  = {The Central Pontides is an accretionary-type orogenic area within the Alpine-Himalayan orogenic belt characterized by pre-collisional tectonic continental growth. The region comprises Mesozoic subduction-accretionary complexes and an accreted intra-oceanic arc that are sandwiched between the Laurasian active continental margin and Gondwana-derived the K{\i}r{\c{s}}ehir Block. The subduction-accretion complexes mainly consist of an Albian-Turonian accretionary wedge representing the Laurasian active continental margin. To the north, the wedge consists of slate/phyllite and metasandstone intercalation with recrystallized limestone, Na-amphibole-bearing metabasite (PT= 7-12 kbar and 400 ± 70 ºC) and tectonic slices of serpentinite representing accreted distal part of a large Lower Cretaceous submarine turbidite fan deposited on the Laurasian active continental margin that was subsequently accreted and metamorphosed. Raman spectra of carbonaceous material (RSCM) of the metapelitic rocks revealed that the metaflysch sequence consists of metamorphic packets with distinct peak metamorphic temperatures. The majority of the metapelites are low-temperature (ca. 330 °C) slates characterized by lack of differentiation of the graphite (G) and D2 defect bands. They possibly represent offscraped distal turbidites along the toe of the Albian accretionary wedge. The rest are phyllites that are characterized by slightly pronounced G band with D2 defect band occurring on its shoulder. Peak metamorphic temperatures of these phyllites are constrained to 370-385 °C. The phyllites are associated with a strip of incipient blueschist facies metabasites which are found as slivers within the offscraped distal turbidites. They possibly represent underplated continental metasediments together with oceanic crustal basalt along the basal d{\´e}collement. Tectonic emplacement of the underplated rocks into the offscraped distal turbidites was possibly achieved by out-of-sequence thrusting causing tectonic thickening and uplift of the wedge. 40Ar/39Ar phengite ages from the phyllites are ca. 100 Ma, indicating Albian subduction and regional HP metamorphism. The accreted continental metasediments are underlain by HP/LT metamorphic rocks of oceanic origin along an extensional shear zone. The oceanic metamorphic sequence mainly comprises tectonically thickened deep-seated eclogite to blueschist facies metabasites and micaschists. In the studied area, metabasites are epidote-blueschists locally with garnet (PT= 17 ± 1 kbar and 500 ± 40 °C). Lawsonite-blueschists are exposed as blocks along the extensional shear zone (PT= 14 ± 2 kbar and 370-440 °C). They are possibly associated with low shear stress regime of the initial stage of convergence. Close to the shear zone, the footwall micaschists consist of quartz, phengite, paragonite, chlorite, rutile with syn-kinematic albite porphyroblast formed by pervasive shearing during exhumation. These types of micaschists are tourmaline-bearing and their retrograde nature suggests high-fluid flux along shear zones. Peak metamorphic mineral assemblages are partly preserved in the chloritoid-micaschist farther away from the shear zone representing the zero strain domains during exhumation. Three peak metamorphic assemblages are identified and their PT conditions are constrained by pseudosections produced by Theriak-Domino and by Raman spectra of carbonaceous material: 1) garnet-chloritoid-glaucophane with lawsonite pseudomorphs (P= 17.5 ± 1 kbar, T: 390-450 °C) 2) chloritoid with glaucophane pseudomorphs (P= 16-18 kbar, T: 475 ± 40 °C) and 3) relatively high-Mg chloritoid (17\%) with jadeite pseudomorphs (P= 22-25 kbar; T: 440 ± 30 °C) in addition to phengite, paragonite, quartz, chlorite, rutile and apatite. The last mineral assemblage is interpreted as transformation of the chloritoid + glaucophane assemblage to chloritoid + jadeite paragenesis with increasing pressure. Absence of tourmaline suggests that the chloritoid-micaschist did not interact with B-rich fluids during zero strain exhumation. 40Ar/39Ar phengite age of a pervasively sheared footwall micaschist is constrained to 100.6 ± 1.3 Ma and that of a chloritoid-micaschist is constrained to 91.8 ± 1.8 Ma suggesting exhumation during on-going subduction with a southward younging of the basal accretion and the regional metamorphism. To the south, accretionary wedge consists of blueschist and greenschist facies metabasite, marble and volcanogenic metasediment intercalation. 40Ar/39Ar phengite dating reveals that this part of the wedge is of Middle Jurassic age partly overprinted during the Albian. Emplacement of the Middle Jurassic subduction-accretion complexes is possibly associated with obliquity of the Albian convergence. Peak metamorphic assemblages and PT estimates of the deep-seated oceanic metamorphic sequence suggest tectonic stacking within wedge with different depths of burial. Coupling and exhumation of the distinct metamorphic slices are controlled by decompression of the wedge possibly along a retreating slab. Structurally, decompression of the wedge is evident by an extensional shear zone and the footwall micaschists with syn-kinematic albite porphyroblasts. Post-kinematic garnets with increasing grossular content and pseudomorphing minerals within the chloritoid-micaschists also support decompression model without an extra heating. Thickening of subduction-accretionary complexes is attributed to i) significant amount of clastic sediment supply from the overriding continental domain and ii) deep level basal underplating by propagation of the d{\´e}collement along a retreating slab. Underplating by basal d{\´e}collement propagation and subsequent exhumation of the deep-seated subduction-accretion complexes are connected and controlled by slab rollback creating a necessary space for progressive basal accretion along the plate interface and extension of the wedge above for exhumation of the tectonically thickened metamorphic sequences. This might be the most common mechanism of the tectonic thickening and subsequent exhumation of deep-seated HP/LT subduction-accretion complexes. To the south, the Albian-Turonian accretionary wedge structurally overlies a low-grade volcanic arc sequence consisting of low-grade metavolcanic rocks and overlying metasedimentary succession is exposed north of the İzmir-Ankara-Erzincan suture (İAES), separating Laurasia from Gondwana-derived terranes. The metavolcanic rocks mainly consist of basaltic andesite/andesite and mafic cognate xenolith-bearing rhyolite with their pyroclastic equivalents, which are interbedded with recrystallized pelagic limestone and chert. The metavolcanic rocks are stratigraphically overlain by recrystallized micritic limestone with rare volcanogenic metaclastic rocks. Two groups can be identified based on trace and rare earth element characteristics. The first group consists of basaltic andesite/andesite (BA1) and rhyolite with abundant cognate gabbroic xenoliths. It is characterized by relative enrichment of LREE with respect to HREE. The rocks are enriched in fluid mobile LILE, and strongly depleted in Ti and P reflecting fractionation of Fe-Ti oxides and apatite, which are found in the mafic cognate xenoliths. Abundant cognate gabbroic xenoliths and identical trace and rare earth elements compositions suggest that rhyolites and basaltic andesites/andesites (BA1) are cogenetic and felsic rocks were derived from a common mafic parental magma by fractional crystallization and accumulation processes. The second group consists only of basaltic andesites (BA2) with flat REE pattern resembling island arc tholeiites. Although enriched in LILE, this group is not depleted in Ti or P. Geochemistry of the metavolcanic rocks indicates supra-subduction volcanism evidenced by depletion of HFSE and enrichment of LILE. The arc sequence is sandwiched between an Albian-Turonian subduction-accretionary complex representing the Laurasian active margin and an ophiolitic m{\´e}lange. Absence of continent derived detritus in the arc sequence and its tectonic setting in a wide Cretaceous accretionary complex suggest that the K{\"o}sdağ Arc was intra-oceanic. This is in accordance with basaltic andesites (BA2) with island arc tholeiite REE pattern. Zircons from two metarhyolite samples give Late Cretaceous (93.8 ± 1.9 and 94.4 ± 1.9 Ma) U/Pb ages. Low-grade regional metamorphism of the intra-oceanic arc sequence is constrained 69.9 ± 0.4 Ma by 40Ar/39Ar dating on metamorphic muscovite from a metarhyolite indicating that the arc sequence became part of a wide Tethyan Cretaceous accretionary complex by the latest Cretaceous. The youngest 40Ar/39Ar phengite age from the overlying subduction-accretion complexes is 92 Ma confirming southward younging of an accretionary-type orogenic belt. Hence, the arc sequence represents an intra-oceanic paleo-arc that formed above the sinking Tethyan slab and finally accreted to Laurasian active continental margin. Abrupt non-collisional termination of arc volcanism was possibly associated with southward migration of the arc volcanism similar to the Izu-Bonin-Mariana arc system. The intra-oceanic K{\"o}sdağ Arc is coeval with the obducted supra-subduction ophiolites in NW Turkey suggesting that it represents part of the presumed but missing incipient intra-oceanic arc associated with the generation of the regional supra-subduction ophiolites. Remnants of a Late Cretaceous intra-oceanic paleo-arc and supra-subduction ophiolites can be traced eastward within the Alp-Himalayan orogenic belt. This reveals that Late Cretaceous intra-oceanic subduction occurred as connected event above the sinking Tethyan slab. It resulted as arc accretion to Laurasian active margin and supra-subduction ophiolite obduction on Gondwana-derived terranes.},
  language  = {en}
}
@phdthesis{Partosch2015,
  author    = {Partosch, Falko},
  title     = {Computergest{\"u}tzte Analysen in der Toxikologie},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82334},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVII, 131, ix},
  year      = {2015},
  abstract  = {Im Rahmen der EU-weiten REACH-Verordnung haben Alternativmethoden zum Tierversuch in der Toxikologie an Bedeutung gewonnen. Die Alternativmethoden gliedern sich auf in In-vitro- und In-silico-Methoden. In dieser Dissertation wurden verschiedene Konzepte der In-silico-Toxikologie behandelt. Die bearbeiteten Themen reichen von quantitativen Strukturaktivit{\"a}tsbeziehungen (QSAR) {\"u}ber eine neue Herangehensweise an das g{\"a}ngige Konzept zur Festlegung von Grenzwerten bis hin zu computerbasierten Modellierungen zum Alkohol- und Bisphenol-A-Stoffwechsel. Das Kapitel {\"u}ber QSAR befasst sich im Wesentlichen mit der Erstellung und Analyse einer Datenbank mit 878 Substanzen, die sich aus Tierversuchsstudien aus dem Archiv des Bundesinstituts f{\"u}r Risikobewertung zusammensetzt. Das Design wurde dabei an eine bereits bestehende Datenbank angepasst, um so einen m{\"o}glichst großen Datenpool zu generieren. In der Analyse konnte u.a. gezeigt werden, dass Stoffe mit niedrigerem Molekulargewicht ein erh{\"o}htes Potential f{\"u}r toxikologische Sch{\"a}den aufwiesen als gr{\"o}ßere Molek{\"u}le. Mit Hilfe des sogenannten TTC-Konzepts k{\"o}nnen Grenzwerte f{\"u}r Stoffe geringer Exposition festgelegt werden, zu denen keine toxikologischen Daten zur Verf{\"u}gung stehen. In dieser Arbeit wurden f{\"u}r die Stoffe dreier Datenbanken entsprechende Grenzwerte festgelegt. Es erfolgte zun{\"a}chst eine g{\"a}ngige strukturbasierte Aufteilung der Substanzen in die Kategorien "nicht toxisch", "m{\"o}glicherweise toxisch" und "eindeutig toxisch". Substanzen, die aufgrund ihrer Struktur in eine der drei Klassen eingeordnet werden, erhalten den entsprechenden Grenzwert. Da in die dritte Klasse auch Stoffe eingeordnet werden, deren Toxizit{\"a}t nicht bestimmbar ist, ist sie sehr groß. Daher wurden in dieser Arbeit die ersten beiden Klassen zusammengelgt, um einen gr{\"o}ßeren Datenpool zu erm{\"o}glichen. Eine weitere Neuerung umfasst die Erstellung eines internen Grenzwerts. Diese Vorgehensweise hat den Vorteil, dass der Expositionsweg herausgerechnet wird und somit beispielsweise Studien mit oraler Verabreichung mit Studien dermaler Verabreichung verglichen werden k{\"o}nnen. Mittels physiologisch basiertem kinetischem Modelling ist es m{\"o}glich, Vorg{\"a}nge im menschlichen K{\"o}rper mit Hilfe spezieller Software nachzuvollziehen. Durch diese Vorgehensweise k{\"o}nnen Expositionen von Chemikalien simuliert werden. In einem Teil der Arbeit wurden Alkoholexpositionen von gestillten Neugeborenen simuliert, deren M{\"u}tter unmittelbar zuvor alkoholische Getr{\"a}nke konsumiert hatten. Mit dem Modell konnte gezeigt werden, dass die Expositionen des Kindes durchweg gering waren. Nach einem Glas Wein wurden Spitzenkonzentrationen im Blut von Neugeborenen von 0,0034 Promille ermittelt. Zum Vergleich wurde die Exposition durch ein f{\"u}r S{\"a}uglinge zugelassenes alkoholhaltiges pflanzliches Arzneimittel simuliert. Hier wurden Spitzenkonzentrationen von 0,0141 Promille erreicht. Daher scheinen Empfehlungen wie gelegentlicher Konsum ohne sch{\"a}digende Wirkung auf das Kind wissenschaftlich fundiert zu sein. Ein weiteres Kinetik-Modell befasste sich mit dem Stoffwechsel von Bisphenol A. Teils widerspr{\"u}chliche Daten zur Belastung mit BPA in der wissenschaftlichen Literatur f{\"u}hren wiederholt zu Anregungen, den Grenzwert der Chemikalie anzupassen. Die Funktionalit{\"a}t der am Metabolismus beteiligten Enzyme kann je nach Individuum unterschiedlich ausgepr{\"a}gt sein. Mittels Modellings konnte hier gezeigt werden, dass dies maßgeblich dazu f{\"u}hrt, dass sich berechnete Plasmaspiegel von Individuen bis zu 4,7-fach unterscheiden. Die Arbeit konnte somit einen Beitrag zur Nutzung und Weiterentwicklung von In-silico-Modellen f{\"u}r diverse toxikologische Fragestellungen leisten.},
  language  = {de}
}
@phdthesis{Priegnitz2015,
  author    = {Priegnitz, Mike},
  title     = {Development of geophysical methods to characterize methane hydrate reservoirs on a laboratory scale},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89321},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 99},
  year      = {2015},
  abstract  = {Gashydrate sind kristalline Feststoffe bestehend aus Wasser und Gasmolek{\"u}len. Sie sind stabil bei erh{\"o}hten Dr{\"u}cken und niedrigen Temperaturen. Nat{\"u}rliche Hydratvorkommen treten daher an Kontinentalh{\"a}ngen, in Permafrostb{\"o}den und in tiefen Seen sowie Binnenmeeren auf. Bei der Hydratbildung orientieren sich die Wassermolek{\"u}le neu und bilden sogenannte K{\"a}figstrukturen, in die Gas eingelagert werden kann. Aufgrund des hohen Drucks bei der Hydratbildung k{\"o}nnen große Mengen an Gas in die Hydratstruktur eingebaut werden. Das Volumenverh{\"a}ltnis von Wasser zu Gas kann dabei bis zu 1:172 bei 0°C und Atmosph{\"a}rendruck betragen. Nat{\"u}rliche Gashydrate enthalten haupts{\"a}chlich Methan. Da Methan sowohl ein Treibhausgas als auch ein Brenngas ist, stellen Gashydrate gleichermaßen eine potentielle Energieressource sowie eine m{\"o}gliche Quelle f{\"u}r Treibhausgase dar. Diese Arbeit untersucht die physikalischen Eigenschaften von Methanhydrat ges{\"a}ttigten Sedimentproben im Labormaßstab. Dazu wurde ein großer Reservoirsimulator (LARS) mit einer eigens entwickelten elektrischen Widerstandstomographie ausger{\"u}stet, die das erste Mal an hydratges{\"a}ttigten Sedimentproben unter kontrollierten Temperatur-, Druck-, und Hydrats{\"a}ttigungsbedingungen im Labormaßstab angewendet wurde. {\"U}blicherweise ist der Porenraum von (marinen) Sedimenten mit elektrisch gut leitendem Salzwasser gef{\"u}llt. Da Hydrate einen elektrischen Isolator darstellen, ergeben sich große Kontraste hinsichtlich der elektrischen Eigenschaften im Porenraum w{\"a}hrend der Hydratbildung und -zersetzung. Durch wiederholte Messungen w{\"a}hrend der Hydraterzeugung ist es m{\"o}glich die r{\"a}umliche Widerstandsverteilung in LARS aufzuzeichnen. Diese Daten bilden in der Folge die Grundlage f{\"u}r eine neue Auswerteroutine, welche die r{\"a}umliche Widerstandsverteilung in die r{\"a}umliche Verteilung der Hydrats{\"a}ttigung {\"u}berf{\"u}hrt. Dadurch ist es m{\"o}glich, die sich {\"a}ndernde Hydrats{\"a}ttigung sowohl r{\"a}umlich als auch zeitlich hoch aufgel{\"o}st w{\"a}hrend der gesamten Hydraterzeugungsphase zu verfolgen. Diese Arbeit zeigt, dass die entwickelte Widerstandstomographie eine gute Datenqualit{\"a}t aufwies und selbst geringe Hydrats{\"a}ttigungen innerhalb der Sedimentprobe detektiert werden konnten. Bei der Umrechnung der Widerstandsverteilung in lokale Hydrat-S{\"a}ttigungswerte wurden die besten Ergebnisse mit dem Archie-var-phi Ansatz erzielt, der die zunehmende Hydratphase dem Sedimentger{\"u}st zuschreibt, was einer Abnahme der Porosit{\"a}t gleichkommt. Die Widerstandsmessungen zeigten weiterhin, dass die schnelle Hydraterzeugung im Labor zur Ausbildung von kleinen Hydratkristallen f{\"u}hrte, die dazu neigten, zu rekristalliesieren. Es wurden weiterhin Hydrat-Abbauversuche durchgef{\"u}hrt, bei denen die Hydratphase {\"u}ber Druckerniedrigung in Anlehnung an den 2007/2008 Mallik Feldtest zersetzt wurde. Dabei konnte beobachtet werden, dass die Muster der Gas- undWasserflussraten im Labor zum Teil gut nachgebildet werden konnten, jedoch auch aufbaubedingte Abweichungen auftraten. In zwei weiteren Langzeitversuchen wurde die Realisierbarkeit und das Verhalten bei CO2-CH4-Hydrat Austauschversuchen in LARS untersucht. Das tomographische Messsystem wurde dabei genutzt um w{\"a}hrend der CH4 Hydrat Aufbauphase die Hydratverteilung innerhalb der Sedimentprobe zu {\"u}berwachen. Im Zuge der anschließenden CO2-Injektion konnte mithilfe der Widerstandstomographie die sich ausbreitende CO2-Front {\"u}berwacht und der Zeitpunkt des CO2 Durchbruchs identifiziert werden.},
  language  = {en}
}
@phdthesis{TabaresJimenez2015,
  author    = {Tabares Jim{\´e}nez, Adri{\´a}n de Jes{\´u}s},
  title     = {Palabras de fundadores, forasteros y cachacos},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85630},
  school      = {Universit{\"a}t Potsdam},
  pages     = {227},
  year      = {2015},
  abstract  = {Die vorliegende Dissertation analysiert die Mentalit{\"a}ten der b{\"u}rgerlichen Bewohner Bogotas 19. Jahrhundert. Einblicke in die Fremd- und Eigenperspektiven der Bogotaner werden durch die Analyse von Reiseliteratur gewonnen. Methodologisch st{\"u}tzt sich die Arbeit auf den Vergleich zwischen europ{\"a}ischen Reiseberichten aus dem 19. Jh., Chroniken aus dem 16. Jh. sowie zwei kolumbianische Romane aus dem fr{\"u}hen 20.. Jh. Die Texte werden historiographisch behandelt; obwohl sie unterschiedlichen literarischen Genres angeh{\"o}ren, weisen sie einen gemeinsamen autobiographischen Charakter auf. Aus den Erfahrungen und Gedanken der Reisenden werden v.a. die Auswirkungen der geographischen und sozialen Isolation thematisiert, sowie die Einfl{\"u}sse von politischen und religi{\"o}sen Diskursen auf die Bildung von b{\"u}rgerlichem Gedankengut.},
  language  = {es}
}
@phdthesis{Ucar2015,
  author    = {U{\c{c}}ar, Magdalena},
  title     = {Zeugenschaft im Bild},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-406087},
  school      = {Universit{\"a}t Potsdam},
  pages     = {145},
  year      = {2015},
  abstract  = {Zentrales Anliegen der Dissertation ist, Zeugenschaft als visuelle Strategie zu beleuchten. In Abgrenzung zur These der Undarstellbarkeit der Shoah wird der Begriff der Sichtbarmachung nutzbar gemacht, um Prozesse und die Wirkung von Bildern im Zusammenhang mit Zeugenschaft herauszustellen. Ausgangspunkt dabei ist, dass bildliche Zeugnisse einen Gegenpol zu den standardisierten Visualisierungspraktiken der Shoah bieten, sprich dem historischen Bildmaterial aufgenommen durch die Alliierten und der Nationalsozialisten. In der Arbeit wird das historische Bildmaterial als Visualisierungspraxis problematisiert und visuellen Zeugnissen gegen{\"u}bergestellt, die Augen- und {\"U}berlebenszeugen der Shoah, aber auch authentische Orte des Geschehens aus einer nachtr{\"a}glichen Perspektive zeigen. Dabei werden insbesondere zwei kritische Strategien des Umgangs mit historischen Bildern der Shoah hervorgehoben: das Hinterfragen von Archivbildern innerhalb des Films (Harun Farockis AUFSCHUB, 2007) und die Verweigerung von Archivbildern aus der Zeit des Zweiten Weltkrieges (Claude Lanzmanns SHOAH, 1985). Seit den 1990er Jahren wird Zeugenschaft in der Forschung als philosophische, moralische und erkenntnistheoretische Kategorie in den USA, aber auch in Deutschland viel diskutiert. Dabei wurde die bild- und medienwissenschaftliche Perspektive im Zusammenhang mit Zeugenschaft kaum beleuchtet, darin liegt der Forschungsbeitrag der Arbeit. Insbesondere drei Gesichtspunkte von visueller Zeugenschaft werden herausgearbeitet: 1) die Sichtbarmachung der {\"U}berlebenden und der Orte des Geschehens im Jetzt, 2) die nichtsprachlichen Aspekte von Zeugenaussagen und 3) die Rolle des Zuschauers, der durch den Akt des Sehens in einem Imaginationsprozess eine Verkn{\"u}pfung zwischen den Bildern aus der Jetztzeit und der nicht-sichtbaren Vergangenheit herstellt. Polen nimmt eine besondere historische Rolle als Zentrum des europ{\"a}ischen Judentums bis zum Zweiten Weltkrieg und gleichzeitig als »Schauplatz des Holocaust« und Ort der Augenzeugenschaft ein. Maßgeblich hat Claude Lanzmanns Film SHOAH dazu beigetragen, die Konzentrations- und Vernichtungslager im Polen der Nachkriegszeit sichtbar zu machen, und damit nicht nur Generationen von polnischen Filmemachern und K{\"u}nstlern nach ihm beeinflusst, sondern auch kontroverse Debatten in Polen ausgel{\"o}st. Anhand der ausgew{\"a}hlten Filme l{\"a}sst sich in der polnischen Erinnerungskultur seit der Wende von 1989 eine Hinwendung zur polnisch-j{\"u}dischen Geschichte erkennen, die sich verst{\"a}rkt mit den Fragen der polnischen Mitt{\"a}terschaft und Schuld an der Shoah auseinandersetzt. Der Untersuchungsgegenstand unterteilt sich in zwei Formate: Dokumentar- und Kunstfilm. Einerseits ist das auf ihre unterschiedlichen Produktions- und Rezeptionsbedingungen sowie die L{\"a}nge der Arbeiten zur{\"u}ckzuf{\"u}hren. Andererseits bewegen sich die Kategorien auf verschiedenen Reflexionsebenen und zielen auf unterschiedliche Wirkungen beim Zuschauer ab. W{\"a}hrend sich in den Dokumentarfilmen zum Teil explizite Bez{\"u}ge (aber auch Abgrenzungen) zum Lanzmann'schen Projekt erkennen lassen, handelt es sich bei den Produktionen des zeitgen{\"o}ssischen K{\"u}nstlers Artur Żmijewski um einen Meta-Diskurs, der auf radikale und provokative Art und Weise bestehende erinnerungskulturelle Praktiken ausstellt und kritisch hinterfragt.},
  language  = {de}
}
@phdthesis{Helpa2015,
  author    = {Helpa, Vanessa},
  title     = {Interplay between mineral reaction and deformation via structural defects},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90332},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 104},
  year      = {2015},
  abstract  = {This thesis contains three experimental studies addressing the interplay between deformation and the mineral reaction between natural calcite and magnesite. The solid-solid mineral reaction between the two carbonates causes the formation of a magnesio-calcite precursor layer and a dolomite reaction rim in every experiment at isostatic annealing and deformation conditions. CHAPTER 1 briefly introduces general aspects concerning mineral reactions in nature and diffusion pathways for mass transport. Moreover, results of previous laboratory studies on the influence of deformation on mineral reactions are summarized. In addition, the main goals of this study are pointed out. In CHAPTER 2, the reaction between calcite and magnesite single crystals is examined at isostatic annealing conditions. Time series performed at a fixed temperature revealed a diffusion-controlled dolomite rim growth. Two microstructural domains could be identified characterized by palisade-shaped dolomite grains growing into the magnesite and granular dolomite growing towards calcite. A model was provided for the dolomite rim growth based on the counter-diffusion of CaO and MgO. All reaction products exhibited a characteristic crystallographic relationship with respect to the calcite reactant. Moreover, kinetic parameters of the mineral reaction were determined out of a temperature series at a fixed time. The main goal of the isostatic test series was to gain information about the microstructure evolution, kinetic parameters, chemical composition and texture development of the reaction products. The results were used as a reference to quantify the influence of deformation on the mineral reaction. CHAPTER 3 deals with the influence of non-isostatic deformation on dolomite and magnesio-calcite layer production between calcite and magnesite single crystals. Deformation was achieved by triaxial compression and by torsion. Triaxial compression up to 38 MPa axial stress at a fixed time showed no significant influence of stress and strain on dolomite formation. Time series conducted at a fixed stress yield no change in growth rates for dolomite and magnesio-calcite at low strains. Slightly larger magnesio-calcite growth rates were observed at strains above >0.1. High strains at similar stresses were caused by the activation of additional glide systems in the calcite single crystal and more mobile dislocations in the magnesio-calcite grains, providing fast diffusion pathways. In torsion experiments a gradual decrease in dolomite and magnesio-calcite layer thickness was observed at a critical shear strain. During deformation, crystallographic orientations of reaction products rearranged with respect to the external framework. A direct effect of the mineral reaction on deformation could not be recognized due to the relatively small reaction product widths. In CHAPTER 4, the influence of starting material microfabrics and the presence of water on the reaction kinetics was evaluated. In these experimental series polycrystalline material was in contact with single crystals or two polycrystalline materials were used as reactants. Isostatic annealing resulted in different dolomite and magnesio-calcite layer thicknesses, depending on starting material microfabrics. The reaction progress at the magnesite interface was faster with smaller magnesite grain size, because grain boundaries provided fast pathways for diffusion and multiple nucleation sites for dolomite formation. Deformation by triaxial compression and torsion yield lower dolomite rim thicknesses compared to annealed samples for the same time. This was caused by grain coarsening of polycrystalline magnesite during deformation. In contrast, magnesio-calcite layers tended to be larger during deformation, which triggered enhanced diffusion along grain boundaries. The presence of excess water had no significant influence on the reaction kinetics, at least if the reactants were single crystals. In CHAPTER 5 general conclusions about the interplay between deformation and the mineral reaction in the carbonate system are presented. Finally, CHAPTER 6 highlights possible future work in the carbonate system based on the results of this study.},
  language  = {en}
}
@phdthesis{Streich2015,
  author    = {Streich, David},
  title     = {Understanding massive disk galaxy formation through resolved stellar populations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81027},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 140},
  year      = {2015},
  abstract  = {In this thesis we utilize resolved stellar populations to improve our understanding of galaxy formation and evolution. In the first part we improve a method for metallicity determination of faint old stellar systems, in the second and third part we analyze the individual history of six nearby disk galaxies outside the Local Group. A New Calibration of the Color Metallicity Relation of Red Giants for HST data: It is well known, that the color distribution of stars on the the Red Giant Branch (RGB) can be used to determine metallicities of old stellar populations that have only shallow photometry. Based on the largest sample of globular clusters ever used for such studies, we quantify the relation between metallicity and color in the widely used HST ACS filters F606W and F814W. We use a sample of globular clusters from the ACS Globular Cluster Survey and measure their RGB color at given absolute magnitudes to derive the color-metallicity relation. We find a clear relation between metallicity and RGB color; we investigate the scatter and the uncertainties in this relation and show its limitations. A comparison with isochrones shows reasonably good agreement with BaSTI models, a small offset to Dartmouth models, and a larger offset to Padua models. Even for the best globular cluster data available, the metallicity of a simple stellar population can be determined from the RGB alone only with an accuracy of 0.3 dex for [M/H]<-1, and 0.15 dex for [M/H]>-1. For mixed populations, as they are observed in external galaxies, the uncertainties will be even larger due to uncertainties in extinction, age, etc. Therefore caution is necessary when interpreting photometric metallicities. The Structural History of Nearby Low Mass Disk Galaxies: We study the individual evolution histories of three nearby, low-mass, edge-on galaxies (IC5052, NGC4244, NGC5023). Using the color magnitude diagrams of resolved stellar populations, we construct star count density maps for populations of different ages and analyze the change of structural parameters with stellar age within each galaxy. The three galaxies show low vertical heating rates, which are much lower than the heating rate of the Milky Way. This indicates that heating agents, as giant molecular clouds and spiral structure are weak in low mass galaxies. We do not detect a separate thick disk in any of the three galaxies, even though our observations cover a larger range in equivalent surface brightness than any integrated light study. While scaleheights increase with age, each population can be well described by a single disk. Only two of the galaxies contain a very weak additional component, which we identify as the faint halo. The mass of these faint halos is less than 1\% of the mass of the disk. All populations in the three galaxies exhibit no or only little flaring. While this finding is consistent with previous integrated light studies, it poses strong constraints on galaxy formation models, because most theoretical simulations often find strong flaring due to interactions or radial migration. Furthermore, we find breaks in the radial profiles of all three galaxies. The radii of these breaks are independent of age, and the break strength is decreasing with age in two of the galaxies (NGC4244 and NGC5023). This is consistent with break formation models, that combine a star formation cutoff with radial migration. The differing behavior of IC5052 can be explained by a recent interaction or minor merger. The Structural History of Massive Disk Galaxies: We extend the structural analysis of stellar populations with distinct ages to three massive galaxies, NGC891, NGC4565 and NGC7814. While confusion effects due to the high stellar number densities in their central region, and the prominent dust lanes inhibit an detailed analysis of the radial profiles, we can study their vertical structure. These massive galaxies also have a slower heating than the Milky Way, comparable to the low mass galaxies. This can be traced back to their already thick young populations and thick layers of their interstellar medium. We do not find a clear separate thick disk in any of these three galaxies; all populations can be described by a single disk plus a S\'ersic bulge/halo component. In contrast to the low mass galaxies, we cannot rule out the presence of thick disks in the massive galaxies, because of the strong influence of the halo, that might hide the possible contribution of the thick disk to the vertical star count profiles. However, the faintness of the possible thick disks still points to problems in the earlier ubiquitous findings of thick disks in external galaxies.},
  language  = {en}
}
@phdthesis{Radenacker2015,
  author    = {Radenacker, Anke},
  title     = {Economic consequences of family dissolution},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100217},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 134},
  year      = {2015},
  abstract  = {Welfare states and policies have changed greatly over the past decades, mostly characterized by retrenchments in terms of government spending or in terms of restricted access to certain benefits. In the area of family policies, however, a lot of countries have simultaneously expanded provisions and transfers for families. Bringing together the macro analysis of policy variation and household income changes on the micro-level, the main research question of the dissertation is to what extent economic consequences following separation and divorce in families with children have changed between the 1980s and the 2000s in Germany and the United States. The second research question of the dissertation regards the differences in dissolution outcomes between married and cohabiting parents in Germany. The dissertation thus aims to link institutional regulations of welfare states with the actual income situation of families. To achieve this, a research design was developed that has never been used for the analysis of the economic consequences of family dissolution. For this, the two longest running panel datasets, German Socio-economic Panel (GSOEP) and the US American Panel Study of Income Dynamics (PSID), have been used. The analytic strategy applied to estimate the effects of family dissolution on household income is a difference-in-difference design combined with coarsened exact matching (CEM). To begin with, the dissertation confirmed many findings of previous research, for example regarding the gender differences in family dissolution outcomes. Mothers experience clearly higher relative income losses and consequently higher risks of poverty than fathers. This finding is universal, that is it holds for both countries, for all time periods observed, and for all measures of economic outcome that were employed. Another confirmed finding is the higher level of welfare state intervention in Germany compared to the United States. The dissertation also revealed a number of novel findings. The results show that the expansion of family policies in Germany over time has not been accompanied by substantially decreasing income losses for mothers. Though income losses have slightly decreased over time, they have become more persistent during the years following family dissolution. The impact of the German welfare state has meanwhile been quite stable. American mothers' income losses took place on a slightly lower level than those of German mothers. Only during the 1980s their relative losses were clearly lower than those of German mothers. And also American mothers did not recover as much from their income losses during the 2000s than they used to during the 1980s. For them, the 1996 welfare reform brought a considerable decrease in welfare state support. Accordingly, the results for American mothers can certainly be described as a shift from public to private provision. The general finding of previous studies that fathers do not have to suffer income losses, or if at all rather moderate ones compared to mothers, can be confirmed. Nevertheless, both German and US American fathers face a deterioration of the economic consequences of family dissolution over time. German fathers' relative income changes are still positive though they have decreased over time. One reason for this decrease is the increasing loss of partner earnings following union dissolution. Also among American fathers, income gains still prevail in the year of family dissolution. Two years later, however, they have been facing income losses already since the 1980s which have furthermore increased considerably over time. Zooming in on Germany, family dissolution outcomes by marital status show negligible differences between cohabiting and married mothers in disposable income, but considerable differences in losses of income before taxes and transfers. It is the impact of the welfare state that equalizes the differences in income losses between these two groups of mothers. For married mothers, losses are not as high in the year of event but they have difficulties to recover from these losses. Without the income buffering of the welfare state, married mothers would, three years after family dissolution, remain with relative income losses double as high as for cohabiting mothers. Compared to mothers, differences between married and cohabiting fathers are visible in changes of income before as well as after taxes and transfers. The welfare state does not alter the difference between the two groups of fathers. With regard to both income concepts, cohabiting fathers fare worse than married fathers. Cohabiting fathers suffer moderate income losses of disposable income while married fathers experience moderate income gains. Accounting for support payments is decisive for fathers' income changes. If these payments are not deducted from disposable income, both married and cohabiting fathers experience gains in disposable income following family dissolution.},
  language  = {en}
}
@phdthesis{Fettkenhauer2015,
  author    = {Fettkenhauer, Christian},
  title     = {Ionothermale Synthese funktioneller Kohlenstoffnitrid basierter Materialien},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-78087},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 123},
  year      = {2015},
  abstract  = {Die Doktorarbeit behandelt die Synthese Kohlenstoffnitrid basierter Materialien in eutektischen Mischungen bivalenter Metallchloride. Der Fokus liegt dabei auf ZnCl2-, SnCl2- und CoCl2-haltigen eutektischen Mischungen, in denen die Kondensation gebr{\"a}uchlicher organischer Precursoren durchgef{\"u}hrt wird. Im Rahmen dessen wird untersucht wie durch die Reaktionsf{\"u}hrung in Salzschmelzen unterschiedlicher Lewis-Acidit{\"a}t, neben der Molek{\"u}lstruktur andere charakteristische Eigenschaften, wie Morphologie, Kristallinit{\"a}t und spezifische Oberfl{\"a}chen, der Materialien kontrolliert werden k{\"o}nnen. Dar{\"u}ber hinaus werden die optischen Eigenschaften der Materialien er{\"o}rtert und in diesem Zusammenhang die Eignung als Photokatalysatoren f{\"u}r den oxidativen Abbau organischer Farbstoffe und f{\"u}r die photokatalytische Wasserreduktion bzw. -oxidation untersucht. Zus{\"a}tzlich wird gezeigt, wie im System LiCl/KCl in einem einstufigen Prozess edelmetallfreie Kohlenstoffnitrid Komposite zur photokatalytischen Wasserreduktion hergestellt werden k{\"o}nnen.},
  language  = {de}
}
@phdthesis{Grygiel2015,
  author    = {Grygiel, Konrad},
  title     = {Poly(ionic liquid) stabilizers and new synthetic approaches},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80367},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 126},
  year      = {2015},
  abstract  = {The main focus of the present thesis was to investigate the stabilization ability of poly(ionic liquid)s (PILs) in several examples as well as develop novel chemical structures and synthetic routes of PILs. The performed research can be specifically divided into three parts that include synthesis and application of hybrid material composed of PIL and cellulose nanofibers (CNFs), thiazolium-containing PILs, and main-chain imidazolium-type PILs. In the first chapter, a vinylimidazolium-type IL was polymerized in water in the presence of CNFs resulting in the in situ electrostatic grafting of polymeric chains onto the surface of CNFs. The synthesized hybrid material merged advantages of its two components, that is, superior mechanical strength of CNFs and anion dependent solution properties of PILs. In contrast to unmodified CNFs, the hybrid could be stabilized and processed in organic solvents enabling its application as reinforcing agent for porous polyelectrolyte membranes. In the second part, PILs and ionic polymers containing two types of thiazolium repeating units were synthesized. Such polymers displayed counterion dependent thermal stability and solubility in organic solvents of various dielectric constants. This new class of PILs was tested as stabilizers and phase transfer agents for carbon nanotubes in aqueous and organic media, and as binder materials to disperse electroactive powders and carbon additives in solid electrode in lithium-ion batteries. The incorporation of S and N atoms into the polymeric structures make such PILs also potential precursors for S, N - co-doped carbons. In the last chapter, reactants originating from biomass were successfully harnessed to synthesize main-chain imidazolium-type PILs. An imidazolium-type diester IL obtained via a modified Debus-Radziszewski reaction underwent transesterification with diol in a polycondensation reaction. This yielded a polyester-type PIL which CO2 sorption properties were investigated. In the next step, the modified Debus-Radziszewski reaction was further applied to synthesize main-chain PILs according to a convenient, one-step protocol, using water as a green solvent and simple organic molecules as reagents. Depending on the structure of the employed diamine, the synthesized PILs after anion exchange showed superior thermal stability with unusually high carbonization yields. Overall, the outcome of these studies will actively contribute to the current research on PILs by introducing novel PIL chemical structures, improved synthetic routes, and new examples of stabilized materials. The synthesis of main-chain imidazolium-type PILs by a modified Debus-Radziszewski reaction is of a special interest for the future work on porous ionic liquid networks as well as colloidal PIL nanoparticles.},
  language  = {en}
}
@phdthesis{Obu2015,
  author    = {Obu, Jaroslav},
  title     = {Effect of mass wasting on soil organic carbon storage and coastal erosion in permafrost environments},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90599},
  school      = {Universit{\"a}t Potsdam},
  pages     = {iii, 93},
  year      = {2015},
  abstract  = {Accelerated permafrost thaw under the warming Arctic climate can have a significant impact on Arctic landscapes. Areas underlain by permafrost store high amounts of soil organic carbon (SOC). Permafrost disturbances may contribute to increased release of carbon dioxide and methane to the atmosphere. Coastal erosion, amplified through a decrease in Arctic sea-ice extent, may also mobilise SOC from permafrost. Large expanses of permafrost affected land are characterised by intense mass-wasting processes such as solifluction, active-layer detachments and retrogressive thaw slumping. Our aim is to assess the influence of mass wasting on SOC storage and coastal erosion. We studied SOC storage on Herschel Island by analysing active-layer and permafrost samples, and compared non-disturbed sites to those characterised by mass wasting. Mass-wasting sites showed decreased SOC storage and material compaction, whereas sites characterised by material accumulation showed increased storage. The SOC storage on Herschel Island is also significantly correlated to catenary position and other slope characteristics. We estimated SOC storage on Herschel Island to be 34.8 kg C m-2. This is comparable to similar environments in northwest Canada and Alaska. Coastal erosion was analysed using high resolution digital elevation models (DEMs). Two LIDAR scanning of the Yukon Coast were done in 2012 and 2013. Two DEMs with 1 m horizontal resolution were generated and used to analyse elevation changes along the coast. The results indicate considerable spatial variability in short-term coastline erosion and progradation. The high variability was related to the presence of mass-wasting processes. Erosion and deposition extremes were recorded where the retrogressive thaw slump (RTS) activity was most pronounced. Released sediment can be transported by longshore drift and affects not only the coastal processes in situ but also along adjacent coasts. We also calculated volumetric coastal erosion for Herschel Island by comparing a stereo-photogrammetrically derived DEM from 2004 with LIDAR DEMs. We compared this volumetric erosion to planimetric erosion, which was based on coastlines digitised from satellite imagery. We found a complex relationship between planimetric and volumetric coastal erosion, which we attribute to frequent occurrence of mass-wasting processes along the coasts. Our results suggest that volumetric erosion corresponds better with environmental forcing and is more suitable for the estimation of organic carbon fluxes than planimetric erosion. Mass wasting can decrease SOC storage by several mechanisms. Increased aeration following disturbance may increase microbial activity, which accelerates organic matter decomposition. New hydrological conditions that follow the mass wasting event can cause leaching of freshly exposed material. Organic rich material can also be directly removed into the sea or into a lake. On the other hand the accumulation of mobilised material can result in increased SOC storage. Mass-wasting related accumulations of mobilised material can significantly impact coastal erosion in situ or along the adjacent coast by longshore drift. Therefore, the coastline movement observations cannot completely resolve the actual sediment loss due to these temporary accumulations. The predicted increase of mass-wasting activity in the course of Arctic warming may increase SOC mobilisation and coastal erosion induced carbon fluxes.},
  language  = {en}
}
@phdthesis{Lischke2015,
  author    = {Lischke, Betty},
  title     = {Food web regulation under different forcing regimes in shallow lakes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89149},
  school      = {Universit{\"a}t Potsdam},
  pages     = {131},
  year      = {2015},
  abstract  = {The standing stock and production of organismal biomass depends strongly on the organisms' biotic environment, which arises from trophic and non-trophic interactions among them. The trophic interactions between the different groups of organisms form the food web of an ecosystem, with the autotrophic and bacterial production at the basis and potentially several levels of consumers on top of the producers. Feeding interactions can regulate communities either by severe grazing pressure or by shortage of resources or prey production, termed top-down and bottom-up control, respectively. The limitations of all communities conglomerate in the food web regulation, which is subject to abiotic and biotic forcing regimes arising from external and internal constraints. This dissertation presents the effects of alterations in two abiotic, external forcing regimes, terrestrial matter input and long-lasting low temperatures in winter. Diverse methodological approaches, a complex ecosystem model study and the analysis of two whole-lake measurements, were performed to investigate effects for the food web regulation and the resulting consequences at the species, community and ecosystem scale. Thus, all types of organisms, autotrophs and heterotrophs, at all trophic levels were investigated to gain a comprehensive overview of the effects of the two mentioned altered forcing regimes. In addition, an extensive evaluation of the trophic interactions and resulting carbon fluxes along the pelagic and benthic food web was performed to display the efficiencies of the trophic energy transfer within the food webs. All studies were conducted in shallow lakes, which is worldwide the most abundant type of lakes. The specific morphology of shallow lakes allows that the benthic production contributes substantially to the whole-lake production. Further, as shallow lakes are often small they are especially sensitive to both, changes in the input of terrestrial organic matter and the atmospheric temperature. Another characteristic of shallow lakes is their appearance in alternative stable states. They are either in a clear-water or turbid state, where macrophytes and phytoplankton dominate, respectively. Both states can stabilize themselves through various mechanisms. These two alternative states and stabilizing mechanisms are integrated in the complex ecosystem model PCLake, which was used to investigate the effects of the enhanced terrestrial particulate organic matter (t-POM) input to lakes. The food web regulation was altered by three distinct pathways: (1) Zoobenthos received more food, increased in biomass which favored benthivorous fish and those reduced the available light due to bioturbation. (2) Zooplankton substituted autochthonous organic matter in their diet by suspended t-POM, thus the autochthonous organic matter remaining in the water reduced its transparency. (3) T-POM suspended into the water and reduced directly the available light. As macrophytes are more light-sensitive than phytoplankton they suffered the most from the lower transparency. Consequently, the resilience of the clear-water state was reduced by enhanced t-POM inputs, which makes the turbid state more likely at a given nutrient concentration. In two subsequent winters long-lasting low temperatures and a concurrent long duration of ice coverage was observed which resulted in low overall adult fish biomasses in the two study lakes - Schulzensee and Gollinsee, characterized by having and not having submerged macrophytes, respectively. Before the partial winterkill of fish Schulzensee allowed for a higher proportion of piscivorous fish than Gollinsee. However, the partial winterkill of fish aligned both communities as piscivorous fish are more sensitive to low oxygen concentrations. Young of the year fish benefitted extremely from the absence of adult fish due to lower predation pressure. Therefore, they could exert a strong top-down control on crustaceans, which restructured the entire zooplankton community leading to low crustacean biomasses and a community composition characterized by copepodites and nauplii. As a result, ciliates were released from top-down control, increased to high biomasses compared to lakes of various trophic states and depths and dominated the zooplankton community. While being very abundant in the study lakes and having the highest weight specific grazing rates among the zooplankton, ciliates exerted potentially a strong top-down control on small phytoplankton and particle-attached bacteria. This resulted in a higher proportion of large phytoplankton compared to other lakes. Additionally, the phytoplankton community was evenly distributed presumably due to the numerous fast growing and highly specific ciliate grazers. Although, the pelagic food web was completely restructured after the subsequent partial winterkills of fish, both lakes were resistant to effects of this forcing regime at the ecosystem scale. The consistently high predation pressure on phytoplankton prevented that Schulzensee switched from the clear-water to the turbid state. Further mechanisms, which potentially stabilized the clear-water state, were allelopathic effects by macrophytes and nutrient limitation in summer. The pelagic autotrophic and bacterial production was an order of magnitude more efficient transferred to animal consumers than the respective benthic production, despite the alterations of the food web structure after the partial winterkill of fish. Thus, the compiled mass-balanced whole-lake food webs suggested that the benthic bacterial and autotrophic production, which exceeded those of the pelagic habitat, was not used by animal consumers. This holds even true if the food quality, additional consumers such as ciliates, benthic protozoa and meiobenthos, the pelagic-benthic link and the potential oxygen limitation of macrobenthos were considered. Therefore, low benthic efficiencies suggest that lakes are primarily pelagic systems at least at the animal consumer level. Overall, this dissertation gives insights into the regulation of organism groups in the pelagic and benthic habitat at each trophic level under two different forcing regimes and displays the efficiency of the carbon transfer in both habitats. The results underline that the alterations of external forcing regimes affect all hierarchical level including the ecosystem.},
  language  = {en}
}
@phdthesis{Kappel2015,
  author    = {Kappel, David},
  title     = {Multi-spectrum retrieval of maps of Venus' surface emissivity in the infrared},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85301},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 226},
  year      = {2015},
  abstract  = {The main goal of this cumulative thesis is the derivation of surface emissivity data in the infrared from radiance measurements of Venus. Since these data are diagnostic of the chemical composition and grain size of the surface material, they can help to improve knowledge of the planet's geology. Spectrally resolved images of nightside emissions in the range 1.0-5.1 μm were recently acquired by the InfraRed Mapping channel of the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS-M-IR) aboard ESA's Venus EXpress (VEX). Surface and deep atmospheric thermal emissions in this spectral range are strongly obscured by the extremely opaque atmosphere, but three narrow spectral windows at 1.02, 1.10, and 1.18 μm allow the sounding of the surface. Additional windows between 1.3 and 2.6 μm provide information on atmospheric parameters that is required to interpret the surface signals. Quantitative data on surface and atmosphere can be retrieved from the measured spectra by comparing them to simulated spectra. A numerical radiative transfer model is used in this work to simulate the observable radiation as a function of atmospheric, surface, and instrumental parameters. It is a line-by-line model taking into account thermal emissions by surface and atmosphere as well as absorption and multiple scattering by gases and clouds. The VIRTIS-M-IR measurements are first preprocessed to obtain an optimal data basis for the subsequent steps. In this process, a detailed detector responsivity analysis enables the optimization of the data consistency. The measurement data have a relatively low spectral information content, and different parameter vectors can describe the same measured spectrum equally well. A usual method to regularize the retrieval of the wanted parameters from a measured spectrum is to take into account a priori mean values and standard deviations of the parameters to be retrieved. This decreases the probability to obtain unreasonable parameter values. The multi-spectrum retrieval algorithm MSR is developed to additionally consider physically realistic spatial and temporal a priori correlations between retrieval parameters describing different measurements. Neglecting geologic activity, MSR also allows the retrieval of an emissivity map as a parameter vector that is common to several spectrally resolved images that cover the same surface target. Even applying MSR, it is difficult to obtain reliable emissivity maps in absolute values. A detailed retrieval error analysis based on synthetic spectra reveals that this is mainly due to interferences from parameters that cannot be derived from the spectra themselves, but that have to be set to assumed values to enable the radiative transfer simulations. The MSR retrieval of emissivity maps relative to a fixed emissivity is shown to effectively avoid most emissivity retrieval errors. Relative emissivity maps at 1.02, 1.10, and 1.18 μm are finally derived from many VIRTIS-M-IR measurements that cover a surface target at Themis Regio. They are interpreted as spatial variations relative to an assumed emissivity mean of the target. It is verified that the maps are largely independent of the choice of many interfering parameters as well as the utilized measurement data set. These are the first Venus IR emissivity data maps based on a consistent application of a full radiative transfer simulation and a retrieval algorithm that respects a priori information. The maps are sufficiently reliable for future geologic interpretations.},
  language  = {en}
}
@phdthesis{Bora2015,
  author    = {Bora, Sanjay Singh},
  title     = {Regionally adaptable ground-motion Prediction Equations (GMPEs) for seismic hazard analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88806},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiv, 138},
  year      = {2015},
  abstract  = {Adjustment of empirically derived ground motion prediction equations (GMPEs), from a data- rich region/site where they have been derived to a data-poor region/site, is one of the major challenges associated with the current practice of seismic hazard analysis. Due to the fre- quent use in engineering design practices the GMPEs are often derived for response spectral ordinates (e.g., spectral acceleration) of a single degree of freedom (SDOF) oscillator. The functional forms of such GMPEs are based upon the concepts borrowed from the Fourier spectral representation of ground motion. This assumption regarding the validity of Fourier spectral concepts in the response spectral domain can lead to consequences which cannot be explained physically. In this thesis, firstly results from an investigation that explores the relationship between Fourier and response spectra, and implications of this relationship on the adjustment issues of GMPEs, are presented. The relationship between the Fourier and response spectra is explored by using random vibration theory (RVT), a framework that has been extensively used in earthquake engineering, for instance within the stochastic simulation framework and in the site response analysis. For a 5\% damped SDOF oscillator the RVT perspective of response spectra reveals that no one-to-one correspondence exists between Fourier and response spectral ordinates except in a limited range (i.e., below the peak of the response spectra) of oscillator frequencies. The high oscillator frequency response spectral ordinates are dominated by the contributions from the Fourier spectral ordinates that correspond to the frequencies well below a selected oscillator frequency. The peak ground acceleration (PGA) is found to be related with the integral over the entire Fourier spectrum of ground motion which is in contrast to the popularly held perception that PGA is a high-frequency phenomenon of ground motion. This thesis presents a new perspective for developing a response spectral GMPE that takes the relationship between Fourier and response spectra into account. Essentially, this frame- work involves a two-step method for deriving a response spectral GMPE: in the first step two empirical models for the FAS and for a predetermined estimate of duration of ground motion are derived, in the next step, predictions from the two models are combined within the same RVT framework to obtain the response spectral ordinates. In addition to that, a stochastic model based scheme for extrapolating the individual acceleration spectra beyond the useable frequency limits is also presented. To that end, recorded acceleration traces were inverted to obtain the stochastic model parameters that allow making consistent extrapola- tion in individual (acceleration) Fourier spectra. Moreover an empirical model, for a dura- tion measure that is consistent within the RVT framework, is derived. As a next step, an oscillator-frequency-dependent empirical duration model is derived that allows obtaining the most reliable estimates of response spectral ordinates. The framework of deriving the response spectral GMPE presented herein becomes a self-adjusting model with the inclusion of stress parameter (∆σ) and kappa (κ0) as the predictor variables in the two empirical models. The entire analysis of developing the response spectral GMPE is performed on recently compiled RESORCE-2012 database that contains recordings made from Europe, the Mediterranean and the Middle East. The presented GMPE for response spectral ordinates should be considered valid in the magnitude range of 4 ≤ MW ≤ 7.6 at distances ≤ 200 km.},
  language  = {en}
}