@phdthesis{Zaehle2005,
  author    = {Zaehle, S{\"o}nke},
  title     = {Process-based simulation of the terrestrial biosphere : an evaluation of present-day and future terrestrial carbon balance estimates and their uncertainty},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-5263},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {At present, carbon sequestration in terrestrial ecosystems slows the growth rate of atmospheric CO2 concentrations, and thereby reduces the impact of anthropogenic fossil fuel emissions on the climate system. Changes in climate and land use affect terrestrial biosphere structure and functioning at present, and will likely impact on the terrestrial carbon balance during the coming decades - potentially providing a positive feedback to the climate system due to soil carbon releases under a warmer climate. Quantifying changes, and the associated uncertainties, in regional terrestrial carbon budgets resulting from these effects is relevant for the scientific understanding of the Earth system and for long-term climate mitigation strategies. A model describing the relevant processes that govern the terrestrial carbon cycle is a necessary tool to project regional carbon budgets into the future. This study (1) provides an extensive evaluation of the parameter-based uncertainty in model results of a leading terrestrial biosphere model, the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM), against a range of observations and under climate change, thereby complementing existing studies on other aspects of model uncertainty; (2) evaluates different hypotheses to explain the age-related decline in forest growth, both from theoretical and experimental evidence, and introduces the most promising hypothesis into the model; (3) demonstrates how forest statistics can be successfully integrated with process-based modelling to provide long-term constraints on regional-scale forest carbon budget estimates for a European forest case-study; and (4) elucidates the combined effects of land-use and climate changes on the present-day and future terrestrial carbon balance over Europe for four illustrative scenarios - implemented by four general circulation models - using a comprehensive description of different land-use types within the framework of LPJ-DGVM. This study presents a way to assess and reduce uncertainty in process-based terrestrial carbon estimates on a regional scale. The results of this study demonstrate that simulated present-day land-atmosphere carbon fluxes are relatively well constrained, despite considerable uncertainty in modelled net primary production. Process-based terrestrial modelling and forest statistics are successfully combined to improve model-based estimates of vegetation carbon stocks and their change over time. Application of the advanced model for 77 European provinces shows that model-based estimates of biomass development with stand age compare favourably with forest inventory-based estimates for different tree species. Driven by historic changes in climate, atmospheric CO2 concentration, forest area and wood demand between 1948 and 2000, the model predicts European-scale, present-day age structure of forests, ratio of biomass removals to increment, and vegetation carbon sequestration rates that are consistent with inventory-based estimates. Alternative scenarios of climate and land-use change in the 21<sup>st century suggest carbon sequestration in the European terrestrial biosphere during the coming decades will likely be on magnitudes relevant to climate mitigation strategies. However, the uptake rates are small in comparison to the European emissions from fossil fuel combustion, and will likely decline towards the end of the century. Uncertainty in climate change projections is a key driver for uncertainty in simulated land-atmosphere carbon fluxes and needs to be accounted for in mitigation studies of the terrestrial biosphere.},
  subject      = {Terrestrische {\"O}kologie},
  language  = {en}
}
@phdthesis{Zhang2005,
  author    = {Zhang, Baichen},
  title     = {Dissection of phloem transport in cucurbitaceae by metabolomic analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6644},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {This thesis aimed to investigate several fundamental and perplexing questions relating to the phloem loading and transport mechanisms of Cucurbita maxima, by combining metabolomic analysis with cell biological techniques. This putative symplastic loading species has long been used for experiments on phloem anatomy, phloem biochemistry, phloem transport physiology and phloem signalling. Symplastic loading species have been proposed to use a polymer trapping mechanism to accumulate RFO (raffinose family oligosaccharides) sugars to build up high osmotic pressure in minor veins which sustains a concentration gradient that drives mass flow. However, extensive evidence indicating a low sugar concentration in their phloem exudates is a long-known problem that conflicts with this hypothesis. Previous metabolomic analysis shows the concentration of many small molecules in phloem exudates is higher than that of leaf tissues, which indicates an active apoplastic loading step. Therefore, in the view of the phloem metabolome, a symplastic loading mechanism cannot explain how small molecules other than RFO sugars are loaded into phloem. Most studies of phloem physiology using cucurbits have neglected the possible functions of vascular architecture in phloem transport. It is well known that there are two phloem systems in cucurbits with distinctly different anatomical features: central phloem and extrafascicular phloem. However, mistaken conclusions on sources of cucurbit phloem exudation from previous reports have hindered consideration of the idea that there may be important differences between these two phloem systems. The major results are summarized as below: 1) O-linked glycans in C.maxima were structurally identified as beta-1,3 linked glucose polymers, and the composition of glycans in cucurbits was found to be species-specific. Inter-species grafting experiments proved that these glycans are phloem mobile and transported uni-directionally from scion to stock. 2) As indicated by stable isotopic labelling experiments, a considerable amount of carbon is incorporated into small metabolites in phloem exudates. However, the incorporation of carbon into RFO sugars is much faster than for other metabolites. 3) Both CO2 labelling experiments and comparative metabolomic analysis of phloem exudates and leaf tissues indicated that metabolic processes other than RFO sugar metabolism play an important role in cucurbit phloem physiology. 4) The underlying assumption that the central phloem of cucurbits continuously releases exudates after physical incision was proved wrong by rigorous experiments including direct observation by normal microscopy and combined multiple-microscopic methods. Errors in previous experimental confirmation of phloem exudation in cucurbits are critically discussed. 5) Extrafascicular phloem was proved to be functional, as indicated by phloem-mobile carboxyfluorescein tracer studies. Commissural sieve tubes interconnect phloem bundles into a complete super-symplastic network. 6) Extrafascicular phloem represents the main source of exudates following physical incision. The major transported metabolites by these extrafacicular phloem are non-sugar compounds including amino acids, O-glycans, amines. 7) Central phloem contains almost exclusively RFO sugars, the estimated amount of which is up to 1 to 2 molar. The major RFO sugar present in central phloem is stachyose. 8) Cucurbits utilize two structurally different phloem systems for transporting different group of metabolites (RFO sugars and non-RFO sugar compounds). This implies that cucurbits may use spatially separated loading mechanisms (apoplastic loading for extrafascicular phloem and symplastic loading for central phloem) for supply of nutrients to sinks. 9) Along the transport systems, RFO sugars were mainly distributed within central phloem tissues. There were only small amounts of RFO sugars present in xylem tissues (millimolar range) and trace amounts of RFO sugars in cortex and pith. The composition of small molecules in external central phloem is very different from that in internal central phloem. 10) Aggregated P-proteins were manually dissected from central phloem and analysed by both SDS-PAGE and mass spectrometry. Partial sequences of peptides were obtained by QTOF de novo sequencing from trypsin digests of three SDS-PAGE bands. None of these partial sequences shows significant homology to known cucurbit phloem proteins or other plant proteins. This proves that these central phloem proteins are a completely new group of proteins different from those in extrafascicular phloem. The extensively analysed P-proteins reported in literature to date are therefore now shown to arise from extrafascicular phloem and not central phloem, and therefore do not appear to be involved in the occlusion processes in central phloem.},
  subject      = {phloem},
  language  = {en}
}
@phdthesis{Ziehe2005,
  author    = {Ziehe, Andreas},
  title     = {Blind source separation based on joint diagonalization of matrices with applications in biomedical signal processing},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-5694},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {This thesis is concerned with the solution of the blind source separation problem (BSS). The BSS problem occurs frequently in various scientific and technical applications. In essence, it consists in separating meaningful underlying components out of a mixture of a multitude of superimposed signals. In the recent research literature there are two related approaches to the BSS problem: The first is known as Independent Component Analysis (ICA), where the goal is to transform the data such that the components become as independent as possible. The second is based on the notion of diagonality of certain characteristic matrices derived from the data. Here the goal is to transform the matrices such that they become as diagonal as possible. In this thesis we study the latter method of approximate joint diagonalization (AJD) to achieve a solution of the BSS problem. After an introduction to the general setting, the thesis provides an overview on particular choices for the set of target matrices that can be used for BSS by joint diagonalization. As the main contribution of the thesis, new algorithms for approximate joint diagonalization of several matrices with non-orthogonal transformations are developed. These newly developed algorithms will be tested on synthetic benchmark datasets and compared to other previous diagonalization algorithms. Applications of the BSS methods to biomedical signal processing are discussed and exemplified with real-life data sets of multi-channel biomagnetic recordings.},
  subject      = {Signaltrennung},
  language  = {en}
}
@phdthesis{Ziemer2005,
  author    = {Ziemer, Gesa},
  title     = {Verletzbare Orte : Entwurf einer praktischen {\"A}sthetik},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7374},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {Hauptanliegen der Dissertation ist es, einen Entwurf einer praktischen {\"A}sthetik zu lancieren, der an der Schnittstelle zwischen philosophischer {\"A}sthetik und Kunst - genauer Performancekunst - im Zeichen der Bezugsgr{\"o}sse der Verletzbarkeit steht. In j{\"u}ngeren {\"A}sthetikans{\"a}tzen hat sich eine Auffassung herauskristallisiert, die nicht {\"u}ber, sondern mit Kunst reflektiert. Die Pointe im ‚Mit' liegt darin, dass diese {\"A}sthetiken die Kunst nicht erkl{\"a}ren, sie bestimmen und damit ihre Bedeutung festlegen, sondern dass diese entlang der Kunst die Br{\"u}che, Widerst{\"a}nde und Z{\"a}suren zwischen Wahrnehmen und Denken markieren und diese als produktiv bewerten. Diese Lesart etabliert ein Denken, das nicht aus der Distanz auf etwas schaut (theoria), sondern {\"a}sthetisch-reflektierend (zur{\"u}ckwendend, auch selbstkritisch) mit der Kunst denkt. Die Disziplin der {\"A}sthetik - als aisthesis: Lehre der sinnlichen Wahrnehmung - nimmt innerhalb der Philosophie eine besondere Stellung ein, weil sie auf ebendiese Differenz verweist und deshalb sinnliche und nicht nur logisch-argumentatorische Denkfiguren st{\"a}rkt. Als eine M{\"o}glichkeit, die Kluft, das Nicht-Einholbare, die br{\"u}chige Unzul{\"a}nglichkeit des begrifflich Denkenden gegen{\"u}ber {\"a}sthetischer Erfahrung zu st{\"a}rken, schlage ich die Bezugsgr{\"o}sse der Verletzbarkeit vor. Eine solche {\"A}sthetik besteht aus dem Kreieren verletzbarer Orte, wobei diese auf zweierlei Weisen umkreist werden: Zum einen aus der Kunstpraxis heraus anhand der {\"a}sthetischen Figur des verletzbaren K{\"o}rpes, wie er sich in der zeitgen{\"o}ssischen Performance zeigt. Zum anderen als ein Kreieren von Begriffen im Bewusstsein ihrer Verletzbarkeit. Ausgangspunkte sind die Denkentw{\"u}rfe von Gilles Deleuze und Hans Blumenberg: Die {\"A}sthetik von Gilles Deleuze entwirft eine konkrete {\"U}berschneidungsm{\"o}glichkeit von Kunst und Philosophie, aus der sich meine These des Mit-Kunst-Denkens entwickeln l{\"a}sst. Sie kann aus der Grundvoraussetzung des Deleuzeschen Denkens heraus begr{\"u}ndet werden, die besagt, dass nicht nur die Kunst, sondern auch die Philosophie eine sch{\"o}pferische T{\"a}tigkeit ist. Beide Disziplinen beruhen auf dem Prinzip der creatio continua, durch welche die Kunst Empfindungen und die Philosophie Begriffe sch{\"o}pft, wobei eben genau dieser sch{\"o}pferische Prozess Kunst und Philosophie in ein produktives Verh{\"a}ltnis zueinander treten l{\"a}sst. Wie Deleuze seine Begriffsarbeit entlang k{\"u}nstlerischer Praxis entwickelt, wird anhand der Analyse des bis heute wenig rezipierten Textes Ein Manifest weniger in Bezug auf das Theater von Carmelo Bene analysiert. Eine ganz anderen Zugang zum Entwurf einer praktischen {\"A}sthetik liefert Hans Blumenberg, der eine Theorie der Unbegrifflichkeit in Aussicht stellt. Im Anschluss an seine Forderung, die Metapher wieder vermehrt in die philosophische Denkpraxis zu integrieren, radikalisiert er seine Forderung, auch das Nichtanschauliche zu ber{\"u}cksichtigen, indem er das g{\"a}nzlich Unbegriffliche an die Seite des Begrifflichen stellt. Definitorische Schw{\"a}che zeigt sich als wahrhaftige St{\"a}rke, die in der Unbegrifflichkeit ihren Zenit erreicht. Der Schiffbruch wird von mir als zentrale Metapher - gewissermassen als Metapher der Metapher - verstanden, die das Auf-Grund-Laufen des Allwissenden veranschaulicht. Im Schiffbruch wird die produktive Kollision von Theorie und Praxis deutlich. Deleuze und Blumenberg zeigen {\"u}ber ‚creatio continua' und ‚Unbegrifflichkeit' die Grenzen des Begreifens, indem sie betonen, dass sich {\"A}sthetik nicht nur auf k{\"u}nstlerische Erfahrungen bezieht, sondern selber in das Gegenw{\"a}rtigmachen von Erfahrungen involviert ist. Daraus folgt, dass {\"a}sthetische Reflexion nicht nur begrifflich agieren muss. Die praktische {\"A}sthetik animiert dazu, andere darstellerische Formen (Bilder, T{\"o}ne, K{\"o}rper) als differente und ebenb{\"u}rtige reflexive Modi anzuerkennen und sie als verletzbarmachende Formate der Sprache an die Seite zu stellen. Diese Lesart betont den gestalterischen Aspekt der {\"A}sthetik selber. Zur Verdeutlichung dieser Kluft zwischen (K{\"o}rper-)Bild und Begriff ist der von mir mitgestaltete Film Augen blickeN der Dissertation als Kapitel beigef{\"u}gt. Dieser Film zeigt Performer und Performerinnen, die sich bewusst entschieden haben, ihren ‚abweichenden' K{\"o}rper auf der B{\"u}hne zu pr{\"a}sentieren. Das Wort Verletzbarkeit verweist auf die paradoxe Situation, etwas Br{\"u}chiges tragf{\"a}hig zu machen und dadurch auch auf eine besondere Beziehungsform und auf ein existenzielles Aufeinander-Verwiesensein der Menschen. Verletzbarkeit geht alle an, und stiftet deshalb eine Gemeinsamkeit besonderer Art. In diesem Sinne sind verletzbare Orte nicht nur {\"a}sthetische, sondern auch ethische Orte, womit die politische Dimension des Vorhabens betont wird.},
  subject      = {{\"A}sthetik},
  language  = {de}
}
@phdthesis{Zippel2005,
  author    = {Zippel, Barbara},
  title     = {Einfluss von Intraguild Predation auf die Dynamik der Planktonsukzession in einem sauren Bergbausee},
  address   = {Potsdam},
  pages     = {82 S. : graph. Darst.},
  year      = {2005},
  language  = {de}
}
@phdthesis{Zobel2005,
  author    = {Zobel, Alexander},
  title     = {Agilit{\"a}t im dynamischen Wettbewerb : Basisf{\"a}higkeit zur Bew{\"a}ltigung {\"o}konomischer Turbulenzen},
  publisher = {Deutscher Universit{\"a}tsverlag},
  address   = {Wiesbaden, s.l.},
  isbn      = {3-8244-0846-5},
  doi       = {10.1007/978-3-322-81216-2},
  pages     = {XVI, 304 S. : graph. Darst.},
  year      = {2005},
  language  = {de}
}