@article{Fery2007,
  author    = {F{\´e}ry, Caroline},
  title     = {Information structural notions and the fallacy of invariant correlates},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19692},
  year      = {2007},
  abstract  = {In a first step, definitions of the irreducible information structural categories are given, and in a second step, it is shown that there are no invariant phonological or otherwise grammatical correlates of these categories. In other words, the phonology, syntax or morphology are unable to define information structure. It is a common mistake that information structural categories are expressed by invariant grammatical correlates, be they syntactic, morphological or phonological. It is rather the case that grammatical cues help speaker and hearer to sort out which element carries which information structural role, and only in this sense are the grammatical correlates of information structure important. Languages display variation as to the role of grammar in enhancing categories of information structure, and this variation reflects the variation found in the 'normal' syntax and phonology of languages.},
  language  = {en}
}
@article{EndrissHinterwimmer2007,
  author    = {Endriss, Cornelia and Hinterwimmer, Stefan},
  title     = {Direct and indirect aboutness topics},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19640},
  year      = {2007},
  abstract  = {We propose a definition of aboutness topicality that not only encompasses individual denoting DPs, but also indefinites. We concentrate on the interpretative effects of marking indefinites as topics: they either receive widest scope in their clause, or they are interpreted in the restrictor of an overt or covert Q-adverb. We show that in the first case they are direct aboutness topics insofar as they are the subject of a predication expressed by the comment, while in the second case they are indirect aboutness topics: they define the subject of a higher-order predication - namely the set of situations that the respective Q-adverb quantifies over.},
  language  = {en}
}
@article{Kasimir2006,
  author    = {Kasimir, Elke},
  title     = {On 'nicht...sondern...' (contrastive 'not...but...')},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19537},
  year      = {2006},
  abstract  = {This article presents an analysis of German nicht...sondern... (contrastive not...but...) which departs from the commonly held view that this construction should be explained by appeal to its alleged corrective function. It will be demonstrated that in nicht A sondern B (not A but B), A and B just behave like stand-alone unmarked answers to a common question Q, and that this property of sondern is presuppositional in character. It is shown that from this general observation many interesting properties of nicht...sondern... follow, among them distributional differences between German 'sondern' and German 'aber' (contrastive but, concessive but), intonational requirements and exhaustivity effects. sondern's presupposition is furthermore argued to be the result of the conventionalization of conversational implicatures.},
  language  = {en}
}
@article{vandeVijverSennemaZimmer–Stahl2006,
  author    = {van de Vijver, Ruben and Sennema, Anke and Zimmer-Stahl, Anne},
  title     = {An analysis of pitch and duration in material used to test L2 processing of words},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19583},
  year      = {2006},
  abstract  = {The material reported on in this paper is part of a set of experiments in which the role of Information Structure on L2 processing of words is tested. Pitch and duration of 4 sets of experimental material in German and English are measured and analyzed in this paper. The well-known finding that accent boosts duration and pitch is confirmed. Syntactic and lexical means of marking focus, however, do not give the duration and the pitch of a word an extra boost.},
  language  = {en}
}
@article{SchmitzHoehleMuelleretal.2006,
  author    = {Schmitz, Michaela and H{\"o}hle, Barbara and M{\"u}ller, Anja and Weissenborn, J{\"u}rgen},
  title     = {The recognition of the prosodic focus position in German-learning infants from 4 to 14 months},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19566},
  year      = {2006},
  abstract  = {The aim of the present study was to elucidate in a study with 4-, 6-, 8-, and 14-month-old German-learning children, when and how they may acquire the regularities which underlie Focus-to-Stress Alignment (FSA) in the target language, that is, how prosody is associated with specific communicative functions. Our findings suggest, that 14-month-olds have already found out that German allows for variable focus positions, after having gone through a development which goes from a predominantly prosodically driven processing of the input to a processing where prosody interacts more and more with the growing lexical and syntactic knowledge of the child.},
  language  = {en}
}
@article{EndrissHinterwimmer2006,
  author    = {Endriss, Cornelia and Hinterwimmer, Stefan},
  title     = {Quantificational Variability Effects with plural definites},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19512},
  year      = {2006},
  abstract  = {In this paper we compare the behaviour of adverbs of frequency (de Swart 1993) like usually with the behaviour of adverbs of quantity like for the most part in sentences that contain plural definites. We show that sentences containing the former type of Q-adverb evidence that Quantificational Variability Effects (Berman 1991) come about as an indirect effect of quantification over situations: in order for quantificational variability readings to arise, these sentences have to obey two newly observed constraints that clearly set them apart from sentences containing corresponding quantificational DPs, and that can plausibly be explained under the assumption that quantification over (the atomic parts of) complex situations is involved. Concerning sentences with the latter type of Q-adverb, on the other hand, such evidence is lacking: with respect to the constraints just mentioned, they behave like sentences that contain corresponding quantificational DPs. We take this as evidence that Q-adverbs like for the most part do not quantify over the atomic parts of sum eventualities in the cases under discussion (as claimed by Nakanishi and Romero (2004)), but rather over the atomic parts of the respective sum individuals.},
  language  = {en}
}
@article{HellmuthSkopeteas2007,
  author    = {Hellmuth, Sam and Skopeteas, Stavros},
  title     = {Information structure in linguistic theory and in speech production : validation of a Cross-Linguistic data set},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-939469-72-8},
  issn      = {1866-4725},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19450},
  pages     = {141 -- 186},
  year      = {2007},
  abstract  = {The aim of this paper is to validate a dataset collected by means of production experiments which are part of the Questionnaire on Information Structure. The experiments generate a range of information structure contexts that have been observed in the literature to induce specific constructions. This paper compares the speech production results from a subset of these experiments with specific claims about the reflexes of information structure in four different languages. The results allow us to evaluate and in most cases validate the efficacy of our elicitation paradigms, to identify potentially fruitful avenues of future research, and to highlight issues involved in interpreting speech production data of this kind.},
  language  = {en}
}
@article{KueglerSkopeteasVerhoeven2007,
  author    = {K{\"u}gler, Frank and Skopeteas, Stavros and Verhoeven, Elisabeth},
  title     = {Encoding information structure in Yucatec Maya},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19469},
  year      = {2007},
  abstract  = {The aim of this paper is to outline the means for encoding information structure in Yucatec Maya. Yucatec Maya is a tone language, displaying a three-fold opposition in the tonal realization of syllables. From the morpho-syntactic point of view, the grammar of Yucatec Maya contains morphological (topic affixes, morphological marking of out-of-focus predicates) and syntactic (designated positions) means to uniquely specify syntactic constructions for their information structure. After a descriptive overview of these phenomena, we present experimental evidence which reveals the impact of the nonavailability of prosodic alternatives on the choice of syntactic constructions in language production.},
  language  = {en}
}
@phdthesis{Lange2008,
  author    = {Lange, Dietrich},
  title     = {The South Chilean subduction zone between 41° and 43.5°S : seismicity, structure and state of stress},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18948},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {Die st{\"a}rksten Erdbeben treten an Subduktionszonen auf, so z.B. das st{\"a}rkste instrumentell jemals gemessene Erdbeben vom 22. Mai 1960 mit einer Magnitude von 9,5 Mw in S{\"u}d Chile. In dieser Arbeit werden lokal gewonnene seismologische Daten aus dem zentralen Bereich des 1960er-Bebens vorgestellt. Das seismologische Netzwerk umfasste den chilenischen Forearc zwischen Tiefseegraben und den vulkanischen Bogen zwischen 41,5°-43,5°S und {\"u}berdeckte sowohl die Insel Chilo{\´e} als auch die Nord-S{\"u}d-streichende Liqui{\~n}e-Ofqui St{\"o}rungszone (LOFZ). Zwischen November 2004 und Oktober 2005 konnten 364 lokale Ereignisse registriert werden. Die gewonnen Aufzeichnungen erlauben Aussagen sowohl {\"u}ber das aktuelle Spannungsfeld im Forearc als auch {\"u}ber das lokale Geschwindigkeitsmodell und die Geometrie der subduzierten Benioff-Zone. Mit einer Auswahl von P- und S-Laufzeiten von gut lokalisierbaren Erdbeben wurden ein Minimum 1-D Geschwindigkeitsmodell, Stationsresiduen und die Hypozentralparameter invertiert. Dieses Geschwindigkeitsmodell diente als Startmodell f{\"u}r die 2-D Tomographie. Das 2-D vp-Modell zeigt eine Zone erh{\"o}hter Geschwindigkeiten unterhalb des L{\"a}ngstals und des {\"o}stlichen Bereiches der Insel Chilo{\´e}, die als Mantelaufw{\"o}lbung interpretiert werden kann. Die Benioff-Zone wird als eine mit ca. 30° ostw{\"a}rts einfallende Struktur abgebildet. Die seismische Hauptaktivit{\"a}t findet parallel zur K{\"u}ste der Insel Chilo{\´e} in Tiefen zwischen 12 und 30 km statt; es handelt sich um Beben, die wahrscheinlich auf der Plattengrenzfl{\"a}che stattfinden. In Tiefen {\"u}ber 70 km l{\"a}sst die Seismizit{\"a}t bereits stark nach, die tiefsten Beben wurden in 120 km Tiefe registriert. Die Abwesenheit tieferer Seismizit{\"a}t wird auf das junge Alter (und eine damit verbundene hohe Temperatur) der ozeanischen Platte zur{\"u}ckgef{\"u}hrt. Neben der Seismizit{\"a}t in der Benioff-Zone treten flache, krustale Beben in verschiedenen H{\"a}ufungen entlang des magmatischen Bogens auf. Diese Bereiche erh{\"o}hter Seismizit{\"a}t sind r{\"a}umlich mit der LOFZ und den Vulkanen Chait{\´e}n, Michinmahuida und Corcovado verkn{\"u}pft. Beben bis zu einer Magnitude von 3,8 Mw zeigen die gegenw{\"a}rtige Aktivit{\"a}t der LOFZ. Herdfl{\"a}chen entlang der LOFZ wurden aus Momententensor-Inversion anhand von Amplitudenspektren von Raumwellen gewonnen. Ergebnisse einer Spannungsfeldinversion zeigen ein Blattverschiebungsregime f{\"u}r den magmatischen Bogen und ein {\"U}berschiebungsregime f{\"u}r Beben in der Benioff-Zone auf. Die hier gemachten seismologischen Beobachtungen, zusammen mit teleseismischen Erdbeben und geologischen Befunden, unterst{\"u}tzen die Modellvorstellung eines sich nordw{\"a}rts bewegenden kontinentalen Forearc-Blocks f{\"u}r S{\"u}d Chile.},
  language  = {en}
}
@phdthesis{Kwiecien2008,
  author    = {Kwiecien, Olga},
  title     = {Paleoenvironmental changes in the Black Sea region during the last 26,000 years : a multi-proxy study of lacustrine sediments from the western Black Sea},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19180},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {Paleoenvironmental records provide ample information on the Late Quaternary climatic evolution. Due to the great diversity of continental mid-latitude environments the synthetic picture of the past mid-latitudinal climate changes is, however, far from being complete. Owing to its significant size and landlocked setting the Black Sea constitutes a perfect location to study patterns and mechanisms of climate change along the continental interior of Central and Eastern Europe and Asia Minor. Presently, the southern drainage area of the Black Sea is characterized by a Mediterranean-type climate while the northern drainage is under the influence of Central and Northern European climate. During the Last Glacial a decrease in the global sea level disconnected the Black Sea from the Mediterranean Sea transforming it into a giant closed lake. At that time atmospheric precipitation and related with it river run-off were the most important factors driving sediment supply and water chemistry of the Black 'Lake'. Therefore studying properties of the Black Sea sediments provides important information on the interactions and development of the Mediterranean and Central and North European climate in the past. One significant outcome of my thesis is an improved chronostraphigraphical framework for the glacial lacustrine unit of the Black Sea sediment cores, which allowed to refine the environmental history of the Black Sea region and enabled a reliable correlation with data from other marine and terrestrial archives. Data gathered along a N-S transect presented on a common time scale revealed coherent changes in the basin and its surrounding. During the glacial, the southward-shifted Polar Front reduced moisture transport to the northern drainage of the Black Sea and let the southern drainage become dominant in freshwater and sediment supply into the basin. Changes in NW Anatolian precipitation reconstructed from the variability of the terrigenous input imply that during the glacial the regional rainfall variability was strongly influenced by Mediterranean sea surface temperatures and decreased in response to the cooling associated with the North Atlantic Heinrich Events H1 and H2. In contrast to regional precipitation changes, the hydrological properties of the Black Sea remained relatively stable under full glacial conditions. First significant modification in the freshwater/sediment sources reconstructed from changes in the sediment composition, lithology, and 18O of ostracods took place at around 16.4 cal ka BP, simultaneous to the early deglacial northward retreat of the oceanic and atmospheric polar fronts. Meltwater pulses, most probably derived from the disintegrating European ice sheets, changed the isotopic composition of the Black Sea and increased the supply from northern sediment sources. While these changes signalized a mitigation of the Northern European and Mediterranean climate, a decisive increase in local temperature was indicated only later at the transition from the Oldest Dryas to the B{\o}lling around 14.6 cal ka BP. At that time the warming of the Black Sea surface initiated massive phytoplankton blooms, which in turn, induced the precipitation of inorganic carbonates. This biologically triggered process significantly changed the water chemistry and was recorded by simultaneous shifts in the elemental composition of ostracod shells and in the isotopic composition of the inorganically-precipitated carbonates. Starting with the B/A warming and continuing through the YD cold interval and the Early Holocene warming, the Black Sea temperature signal corresponds to the precipitation and temperature changes recorded in the wider Mediterranean region. Early Holocene conditions, similar to those of the B{\o}lling/Aller{\o}d, were punctured by the marine inflow from the Mediterranean at ~ 9.3 cal ka BP, which terminated the lacustrine phase of the Black Sea and had a substantial impact on the chemical and physical properties of its water.},
  language  = {en}
}
@phdthesis{Vazhappilly2008,
  author    = {Vazhappilly, Tijo Joseph},
  title     = {Vibrationally enhanced associative photodesorption of H2 (D2) from Ru(0001) : quantum and classical approaches},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19056},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {Nowadays, reactions on surfaces are attaining great scientific interest because of their diverse applications. Some well known examples are production of ammonia on metal surfaces for fertilizers and reduction of poisonous gases from automobiles using catalytic converters. More recently, also photoinduced reactions at surfaces, useful, \textit{e.g.}, for photocatalysis, were studied in detail. Often, very short laser pulses are used for this purpose. Some of these reactions are occurring on femtosecond (1 fs=\$10^{-15}\$ s) time scales since the motion of atoms (which leads to bond breaking and new bond formation) belongs to this time range. This thesis investigates the femtosecond laser induced associative photodesorption of hydrogen, H\$_2\$, and deuterium, D\$_2\$, from a ruthenium metal surface. Many interesting features of this reaction were explored by experimentalists: (i) a huge isotope effect in the desorption probability of H\$_2\$ and D\$_2\$, (ii) the desorption yield increases non-linearly with the applied visible (vis) laser fluence, and (iii) unequal energy partitioning to different degrees of freedom. These peculiarities are due to the fact that an ultrashort vis pulse creates hot electrons in the metal. These hot electrons then transfer energy to adsorbate vibrations which leads to desorption. In fact, adsorbate vibrations are strongly coupled to metal electrons, \textit{i.e.}, through non-adiabatic couplings. This means that, surfaces introduce additional channels for energy exchange which makes the control of surface reactions more difficult than the control of reactions in the gas phase. In fact, the quantum yield of surface photochemical reactions is often notoriously small. One of the goals of the present thesis is to suggest, on the basis of theoretical simulations, strategies to control/enhance the photodesorption yield of H\$_2\$ and D\$_2\$ from Ru(0001). For this purpose, we suggest a \textit{hybrid scheme} to control the reaction, where the adsorbate vibrations are initially excited by an infrared (IR) pulse, prior to the vis pulse. Both \textit{adiabatic} and \textit{non-adiabatic} representations for photoinduced desorption problems are employed here. The \textit{adiabatic} representation is realized within the classical picture using Molecular Dynamics (MD) with electronic frictions. In a quantum mechanical description, \textit{non-adiabatic} representations are employed within open-system density matrix theory. The time evolution of the desorption process is studied using a two-mode reduced dimensionality model with one vibrational coordinate and one translational coordinate of the adsorbate. The ground and excited electronic state potentials, and dipole function for the IR excitation are taken from first principles. The IR driven vibrational excitation of adsorbate modes with moderate efficiency is achieved by (modified) \$\pi\$-pulses or/and optimal control theory. The fluence dependence of the desorption reaction is computed by including the electronic temperature of the metal calculated from the two-temperature model. Here, our theoretical results show a good agreement with experimental and previous theoretical findings. We then employed the IR+vis strategy in both models. Here, we found that vibrational excitation indeed promotes the desorption of hydrogen and deuterium. To summarize, we conclude that photocontrol of this surface reaction can be achieved by our IR+vis scheme.},
  language  = {en}
}
@phdthesis{Germer2008,
  author    = {Germer, Sonja},
  title     = {Near-surface hydrology and hydrochemistry under contrasting land-cover},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19049},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {Human transformation of the Earth's land surface has far-reaching and important consequences for the functioning of hydrological and hydrochemical processes in watersheds. In nowadays land-use change from forest to pasture is a major issue in particular in the tropics. A sustainable management of deforested areas requires an in-depth understanding of the water and nutrient cycle. On this basis we compared the involved hydrological pathways for rainfall to reach streams and the nutrient budgets of a tropical rainforest and a pasture. In addition we studied the links of hydrochemical differences to differences of the relative importance of flowpaths. This study was conducted in the southwestern part of the Brazilian Amazon basin. An intensive hydrological and hydrochemical sampling and monitoring network was set up. The results indicate that the hydrology was modified in many ways due to land-use change. The most important alteration was the increased importance of the fast flowpath overland flow. Solute exports were in particular linked to the increased volume of overland flow that resulted from the land-use change. An additional reason for the increased nutrient exports from the pasture are the high concentrations of these nutrients in pasture overland flow probably as a due to cattle excrements. Tight nutrient cycles with minimal nutrient losses could not be maintained after the land-use change. This study provides the first attempt to quantify the respective nutrient losses.},
  language  = {en}
}
@phdthesis{CastroMarin2007,
  author    = {Castro Marin, Inmaculada},
  title     = {Nitrate: metabolism and development},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18827},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {The major aim of this thesis was to study the effect of nitrate on primary metabolism and in development of the model plant Arabidopsis thaliana. The present work has two separate topics. First, to investigate the GDH family, a small gene family at the interface between nitrogen and carbon metabolisms. Second, to investigate the mechanisms whereby nitrogen is regulating the transition to flowering time in Arabidopsis thaliana. To gain more insights into the regulation of primary metabolism by the functional characterization of the glutamate dehydrogenase (GDH) family, an enzyme putatively involved in the metabolism of amino acids and thus suggested to play different and essential roles in carbon and nitrogen metabolism in plants, knock out mutants and transgenic plants carrying RNA interference construct were generated and characterized. The effect of silencing GDH on carbon and nitrogen metabolisms was investigated, especially the level of carbohydrates and the amino acid pool were further analysed. It has been shown that GDH expression is regulated by light and/or sugar status therefore, phenotypic and metabolic analysis were developed in plants grown at different points of the diurnal rhythm and in response to an extended night period. In addition, we are interested in the effect of nutrient availability in the transition from vegetative growth to flowering and especially in nitrate as a metabolite that triggers widespread and coordinated changes in metabolism and development. Nutrient availability has a dramatic effect on flowering time, with a marked delay of flowering when nitrate is supplied (Stitt, 1999). The use of different mutants and transgenic plants impaired in flowering signalling pathways was crucial to evaluate the impact of different nitrate concentrations on flowering time and to better understand the interaction of nitrate-dependent signals with other main flowering signalling pathways. Plants were grown on glutamine as a constitutive source of nitrogen, and the nitrate supply varied. Low nitrate led to earlier flowering. The response to nitrate is accentuated in short days and in the CONSTANS deficient co2 mutant, whereas long days or overexpression of CONSTANS overrides the nitrate response. These results indicate that nitrates acts downstream of the known flowering signalling pathways for photoperiod, autonomy, vernalization and gibberellic acid. Global analyses of gene expression of two independent flowering systems, a light impaired mutant (co2tt4) and a constitutive over-expresser of the potent repressor of flowering (35S::FLC), were to be investigated under two different concentrations of nitrate in order to identify candidate genes that may be involved in the regulation of flowering time by nitrate.},
  language  = {en}
}
@phdthesis{Vijayakrishnan2008,
  author    = {Vijayakrishnan, Balakumar},
  title     = {Solution and solid phase synthesis of N,N'-diacetyl chitotetraoses},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18830},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {The three major biopolymers, proteins, nucleic acids and glycoconjugates are mainly responsible for the information transfer, which is a fundamental process of life. The biological importance of proteins and nucleic acids are well explored and oligosaccharides in the form of glycoconjugates have gained importance recently. The β-(1→4) linked N-acetylglucosamine (GlcNAc) moiety is a frequently occurring structural unit in various naturally and biologically important oligosaccharides and related conjugates. Chitin which is the most abundant polymer of GlcNAc is widely distributed in nature whereas the related polysaccharide chitosan (polymer of GlcN and GlcNAc) occurs in certain fungi. Chitooligosaccharides of mixed acetylation patterns are of interest for the determination of the substrate specificities and mechanism of chitinases. In this report, we describe the chemical synthesis of three chitotetraoses namely GlcNAc-GlcN-GlcNAc-GlcN, GlcN-GlcNAc-GlcNAc-GlcN and GlcN-GlcN-GlcNAc-GlcNAc. Benzyloxycarbonyl (Z) and p-nitrobenzyloxycarbonyl (PNZ) were used for the amino functionality due to their ability to form the β-linkage during the glycosylation reactions through neighboring group participation and the trichloroacetimidate approach was utilized for the donor. Monomeric, dimeric acceptors and donors have been prepared by utilizing the Z and PNZ groups and coupling between the appropriate donor and acceptors in the presence of Lewis acid yielded the protected tetrasaccharides. Finally cleavage of PNZ followed by reacetylation and the deblocking of other protecting groups afforded the N,N'-diacetyl chitotetraoses in good yield. Successful syntheses for the protected diacetyl chitotetraoses by solid phase synthesis have also been described.},
  language  = {en}
}
@phdthesis{GholamiGhadikolaei2007,
  author    = {Gholami Ghadikolaei, Iraj},
  title     = {Data analysis of continuous gravitational waves},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18800},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {This thesis describes two main projects; the first one is the optimization of a hierarchical search strategy to search for unknown pulsars. This project is divided into two parts; the first part (and the main part) is the semi-coherent hierarchical optimization strategy. The second part is a coherent hierarchical optimization strategy which can be used in a project like Einstein@Home. In both strategies we have found that the 3-stages search is the optimum strategy to search for unknown pulsars. For the second project we have developed a computer software for a coherent Multi-IFO (Interferometer Observatory) search. To validate our software, we have worked on simulated data as well as hardware injected signals of pulsars in the fourth LIGO science run (S4). While with the current sensitivity of our detectors we do not expect to detect any true Gravitational Wave signals in our data, we can still set upper limits on the strength of the gravitational waves signals. These upper limits, in fact, tell us how weak a signal strength we would detect. We have also used our software to set upper limits on the signal strength of known isolated pulsars using LIGO fifth science run (S5) data.},
  language  = {en}
}
@phdthesis{Worseck2007,
  author    = {Worseck, G{\´a}bor},
  title     = {The transverse proximity effect in quasar spectra},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18738},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {The intergalactic medium is kept highly photoionised by the intergalactic UV background radiation field generated by the overall population of quasars and galaxies. In the vicinity of sources of UV photons, such as luminous high-redshift quasars, the UV radiation field is enhanced due to the local source contribution. The higher degree of ionisation is visible as a reduced line density or generally as a decreased level of absorption in the Lyman alpha forest of neutral hydrogen. This so-called proximity effect has been detected with high statistical significance towards luminous quasars. If quasars radiate rather isotropically, background quasar sightlines located near foreground quasars should show a region of decreased Lyman alpha absorption close to the foreground quasar. Despite considerable effort, such a transverse proximity effect has only been detected in a few cases. So far, studies of the transverse proximity effect were mostly limited by the small number of suitable projected pairs or groups of high-redshift quasars. With the aim to substantially increase the number of quasar groups in the vicinity of bright quasars we conduct a targeted survey for faint quasars around 18 well-studied quasars at employing slitless spectroscopy. Among the reduced and calibrated slitless spectra of 29000 objects on a total area of 4.39 square degrees we discover in total 169 previously unknown quasar candidates based on their prominent emission lines. 81 potential z>1.7 quasars are selected for confirmation by slit spectroscopy at the Very Large Telescope (VLT). We are able to confirm 80 of these. 64 of the newly discovered quasars reside at z>1.7. The high success rate of the follow-up observations implies that the majority of the remaining candidates are quasars as well. In 16 of these groups we search for a transverse proximity effect as a systematic underdensity in the HI Lyman alpha absorption. We employ a novel technique to characterise the random absorption fluctuations in the forest in order to estimate the significance of the transverse proximity effect. Neither low-resolution spectra nor high-resolution spectra of background quasars of our groups present evidence for a transverse proximity effect. However, via Monte Carlo simulations the effect should be detectable only at the 1-2sigma level near three of the foreground quasars. Thus, we cannot distinguish between the presence or absence of a weak signature of the transverse proximity effect. The systematic effects of quasar variability, quasar anisotopy and intrinsic overdensities near quasars likely explain the apparent lack of the transverse proximity effect. Even in absence of the systematic effects, we show that a statistically significant detection of the transverse proximity effect requires at least 5 medium-resolution quasar spectra of background quasars near foreground quasars whose UV flux exceeds the UV background by a factor 3. Therefore, statistical studies of the transverse proximity effect require large numbers of suitable pairs. Two sightlines towards the central quasars of our survey fields show intergalactic HeII Lyman alpha absorption. A comparison of the HeII absorption to the corresponding HI absorption yields an estimate of the spectral shape of the intergalactic UV radiation field, typically parameterised by the HeII/HI column density ratio eta. We analyse the fluctuating UV spectral shape on both lines of sight and correlate it with seven foreground quasars. On the line of sight towards Q0302-003 we find a harder radiation field near 4 foreground quasars. In the direct vicinity of the quasars eta is consistent with values of 25-100, whereas at large distances from the quasars eta>200 is required. The second line of sight towards HE2347-4342 probes lower redshifts where eta is directly measurable in the resolved HeII forest. Again we find that the radiation field near the 3 foreground quasars is significantly harder than in general. While eta still shows large fluctuations near the quasars, probably due to radiative transfer, the radiation field is on average harder near the quasars than far away from them. We interpret these discoveries as the first detections of the transverse proximity effect as a local hardness fluctuation in the UV spectral shape. No significant HI proximity effect is predicted for the 7 foreground quasars. In fact, the HI absorption near the quasars is close to or slightly above the average, suggesting that the weak signature of the transverse proximity effect is masked by intrinsic overdensities. However, we show that the UV spectral shape traces the transverse proximity effect even in overdense regions or at large distances. Therefore, the spectral hardness is a sensitive physical measure of the transverse proximity effect that is able to break the density degeneracy affecting the traditional searches.},
  language  = {en}
}
@phdthesis{Mueller2008,
  author    = {M{\"u}ller, Melanie J. I.},
  title     = {Bidirectional transport by molecular motors},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18715},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {In biological cells, the long-range intracellular traffic is powered by molecular motors which transport various cargos along microtubule filaments. The microtubules possess an intrinsic direction, having a 'plus' and a 'minus' end. Some molecular motors such as cytoplasmic dynein walk to the minus end, while others such as conventional kinesin walk to the plus end. Cells typically have an isopolar microtubule network. This is most pronounced in neuronal axons or fungal hyphae. In these long and thin tubular protrusions, the microtubules are arranged parallel to the tube axis with the minus ends pointing to the cell body and the plus ends pointing to the tip. In such a tubular compartment, transport by only one motor type leads to 'motor traffic jams'. Kinesin-driven cargos accumulate at the tip, while dynein-driven cargos accumulate near the cell body. We identify the relevant length scales and characterize the jamming behaviour in these tube geometries by using both Monte Carlo simulations and analytical calculations. A possible solution to this jamming problem is to transport cargos with a team of plus and a team of minus motors simultaneously, so that they can travel bidirectionally, as observed in cells. The presumably simplest mechanism for such bidirectional transport is provided by a 'tug-of-war' between the two motor teams which is governed by mechanical motor interactions only. We develop a stochastic tug-of-war model and study it with numerical and analytical calculations. We find a surprisingly complex cooperative motility behaviour. We compare our results to the available experimental data, which we reproduce qualitatively and quantitatively.},
  language  = {en}
}
@book{Narmania2007,
  author    = {Narmania, David},
  title     = {Rights of local jurisdictions and tax revenue distribution in Georgia},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18766},
  publisher      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {This paper describes the administrative powers of local jurisdictions in Georgia, emphasizing on the tax competences and the abilities to mobilize other sources of income. Having listed and explained the types of revenues and incomes, the articles continues to show their distribution among administrative levels according to the current tax code. Following a brief overview of the main laws underlying tax regulation, the existing problems of the status quo before 2007 and some perspectives for the immediate future are outlined.},
  language  = {en}
}
@phdthesis{Tukhlina2008,
  author    = {Tukhlina, Natalia},
  title     = {Feedback control of complex oscillatory systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18546},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {In the present dissertation paper an approach which ensures an efficient control of such diverse systems as noisy or chaotic oscillators and neural ensembles is developed. This approach is implemented by a simple linear feedback loop. The dissertation paper consists of two main parts. One part of the work is dedicated to the application of the suggested technique to a population of neurons with a goal to suppress their synchronous collective dynamics. The other part is aimed at investigating linear feedback control of coherence of a noisy or chaotic self-sustained oscillator. First we start with a problem of suppressing synchronization in a large population of interacting neurons. The importance of this task is based on the hypothesis that emergence of pathological brain activity in the case of Parkinson's disease and other neurological disorders is caused by synchrony of many thousands of neurons. The established therapy for the patients with such disorders is a permanent high-frequency electrical stimulation via the depth microelectrodes, called Deep Brain Stimulation (DBS). In spite of efficiency of such stimulation, it has several side effects and mechanisms underlying DBS remain unclear. In the present work an efficient and simple control technique is suggested. It is designed to ensure suppression of synchrony in a neural ensemble by a minimized stimulation that vanishes as soon as the tremor is suppressed. This vanishing-stimulation technique would be a useful tool of experimental neuroscience; on the other hand, control of collective dynamics in a large population of units represents an interesting physical problem. The main idea of suggested approach is related to the classical problem of oscillation theory, namely the interaction between a self-sustained (active) oscillator and a passive load (resonator). It is known that under certain conditions the passive oscillator can suppress the oscillations of an active one. In this thesis a much more complicated case of active medium, which itself consists of thousands of oscillators is considered. Coupling this medium to a specially designed passive oscillator, one can control the collective motion of the ensemble, specifically can enhance or suppress it. Having in mind a possible application in neuroscience, the problem of suppression is concentrated upon. Second, the efficiency of suggested suppression scheme is illustrated by considering more complex case, i.e. when the population of neurons generating the undesired rhythm consists of two non-overlapping subpopulations: the first one is affected by the stimulation, while the collective activity is registered from the second one. Generally speaking, the second population can be by itself both active and passive; both cases are considered here. The possible applications of suggested technique are discussed. Third, the influence of the external linear feedback on coherence of a noisy or chaotic self-sustained oscillator is considered. Coherence is one of the main properties of self-oscillating systems and plays a key role in the construction of clocks, electronic generators, lasers, etc. The coherence of a noisy limit cycle oscillator in the context of phase dynamics is evaluated by the phase diffusion constant, which is in its turn proportional to the width of the spectral peak of oscillations. Many chaotic oscillators can be described within the framework of phase dynamics, and, therefore, their coherence can be also quantified by the way of the phase diffusion constant. The analytical theory for a general linear feedback, considering noisy systems in the linear and Gaussian approximation is developed and validated by numerical results.},
  language  = {en}
}
@phdthesis{Zemanova2007,
  author    = {Zemanov{\´a}, Lucia},
  title     = {Structure-function relationship in hierarchical model of brain networks},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18400},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {The mammalian brain is, with its numerous neural elements and structured complex connectivity, one of the most complex systems in nature. Recently, large-scale corticocortical connectivities, both structural and functional, have received a great deal of research attention, especially using the approach of complex networks. Here, we try to shed some light on the relationship between structural and functional connectivities by studying synchronization dynamics in a realistic anatomical network of cat cortical connectivity. We model the cortical areas by a subnetwork of interacting excitable neurons (multilevel model) and by a neural mass model (population model). With weak couplings, the multilevel model displays biologically plausible dynamics and the synchronization patterns reveal a hierarchical cluster organization in the network structure. We can identify a group of brain areas involved in multifunctional tasks by comparing the dynamical clusters to the topological communities of the network. With strong couplings of multilevel model and by using neural mass model, the dynamics are characterized by well-defined oscillations. The synchronization patterns are mainly determined by the node intensity (total input strengths of a node); the detailed network topology is of secondary importance. The biologically improved multilevel model exhibits similar dynamical patterns in the two regimes. Thus, the study of synchronization in a multilevel complex network model of cortex can provide insights into the relationship between network topology and functional organization of complex brain networks.},
  language  = {en}
}