@misc{SchmaelzlinWalzKlimantetal.2006, author = {Schm{\"a}lzlin, Elmar and Walz, Bernd and Klimant, Ingo and Schewe, Bettina and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {Monitoring hormone-induced oxygen consumption in the salivary glands of the blowfly, Calliphora vicina, by use of luminescent microbeads}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12206}, year = {2006}, abstract = {The salivary glands of the blowfly were injected with luminescent oxygen-sensitive microbeads. The changes in oxygen content within individual gland tubules during hormone-induced secretory activity were quantified. The measurements are based on an upgraded phase-modulation technique, where the phase shift of the sensor phosphorescence is determined independently from concentration and background signals. We show that the combination of a lock-in amplifier with a fluorescence microscope results in a convenient setup to measure oxygen concentrations within living animal tissues at the cellular level.}, language = {en} } @article{Stoecklein2006, author = {St{\"o}cklein, Walter F. M.}, title = {Molecule-detective}, year = {2006}, abstract = {Biosensors are analytical devices incorporating biological material (receptor) intimately associated with or integrated within a physicochernical transducer. Advantages are the high selectivity for analyte detection. Examples given comprise the very successful commercial blood glucose biosensors made for the self-control by the diabetic patients. Other biosensors are part of an analytic system, including the sensor chips Of surface plasmon resonance or interferometry based devices, piezoelectric or reflectometric sensors capable of direct measurement of mass changes, and thermometric and other reagentless sensors. The development of nanotubes-based devices allows for significant enhancment of the signal-to-noise ratio of the biosensors. A milestone on the way towards miniaturization and parallelization of biosensors is the recently developed and prize-winning electronic DNA chip}, language = {en} } @article{MechauSaphiannikovaNeher2006, author = {Mechau, Norman and Saphiannikova, Marina and Neher, Dieter}, title = {Molecular tracer diffusion in thin azobenzene polymer layers}, series = {Applied physics letters}, volume = {89}, journal = {Applied physics letters}, number = {25}, publisher = {Elsevier}, address = {Melville}, issn = {0003-6951}, doi = {10.1063/1.2405853}, pages = {3}, year = {2006}, abstract = {Translational diffusion of fluorescent tracer molecules in azobenzene polymer layers is studied at different temperatures and under illumination using the method of fluorescence recovery after photobleaching. Diffusion is clearly observed in the dark above the glass transition temperature, while homogeneous illumination at 488 nm and 100 mW/cm(2) does not cause any detectable diffusion of the dye molecules within azobenzene layers. This implies that the viscosity of azobenzene layers remains nearly unchanged under illumination with visible light in the absence of internal or external forces. (c) 2006 American Institute of Physics.}, language = {en} } @article{KetmaierGiustiCaccone2006, author = {Ketmaier, Valerio and Giusti, Folco and Caccone, Adalgisa}, title = {Molecular phylogeny and historical biogeography of the land snail genus Solatopupa (Pulmonata) in the peri- Tyrrhenian area}, issn = {1055-7903}, doi = {10.1016/j.ympev.2005.12.008}, year = {2006}, abstract = {The land snail genus Solatopupa consists of six species and has a peri-Tyrrhenian distribution; most of the species have a very narrow range and all of them except one (Solatopupa cianensis, which inhabits porphyritic rocks) are strictly bound to calcareous substrates. One species (Solatopupa gidoni) is limited to Sardinia, Corsica, and Elba Island. Because the potential for dispersal of these snails is low, the insular range of this species has been traditionally related to the Oligocenic detachment of the Sardinia-Corsica microplate from the Iberian plate and its subsequent rotation towards the Italian peninsula. In this Study, we used sequences of three mitochondrial and one nuclear gene to reconstruct the evolutionary history of the genus. Our phylogenetic results are consistent with the genetic relationships found using allozymes, but contrast with the phylogenetic hypotheses based on karyology and morphology. Molecular clock estimates indicate that the main cladogenetic events in the genus occurred between the middle Miocene and the middle-late Pliocene. Patterns of phylogenetic relationships and geological considerations suggest that the cladogenesis of the genus can be explained by vicariant (tectonic) processes. Our datings do not support a causal relation between the split of S. guidoni from its continental sister taxon and the initial phases of the detachment of the Corsica-Sardinia microplate from the mainland. On the contrary, time estimates coincide with the very last phase of detachment of the microplate (from 5 to 3 Myrs ago). Overall, our molecular clock estimates are in good agreement with the latest geological views on the tectonic evolution of the peri-Tyrrhenian area.}, language = {en} } @article{WachtenSchlenstedtGaussetal.2006, author = {Wachten, Sebastian and Schlenstedt, Jana and Gauss, Renate and Baumann, Arnd}, title = {Molecular identification and functional characterization of an adenylyl cyclase from the honeybee}, doi = {10.1111/j.1471-4159.2006.03666.x}, year = {2006}, abstract = {Cyclic AMP (cAMP) serves as an important messenger in virtually all organisms. In the honeybee (Apis mellifera), cAMP-dependent signal transduction has been implicated in behavioural processes as well as in learning and memory. Key components of cAMP-signalling cascades are adenylyl cyclases. However, the molecular identities and biochemical properties of adenylyl cyclases are completely unknown in the honeybee. We have cloned a cDNA (Amac3) from honeybee brain that encodes a membrane-bound adenylyl cyclase. The Amac3 gene is an orthologue of the Drosophila ac39E gene. The corresponding proteins share an overall amino acid similarity of approximately 62\%. Phylogenetically, AmAC3 belongs to group 1 adenylyl cyclases. Heterologously expressed AmAC3 displays basal enzymatic activity and efficient coupling to endogenous G protein signalling pathways. Stimulation of beta-adrenergic receptors induces AmAC3 activity with an EC50 of about 3.1 mu m. Enzymatic activity is also increased by forskolin (EC50 approximately 15 mu m), a specific agonist of membrane-bound adenylyl cyclases. Similar to certain biogenic amine receptor genes of the honeybee, Amac3 transcripts are expressed in many somata of the brain, especially in mushroom body neurones. These results suggest that the enzyme serves in biogenic amine signal transduction cascades and in higher brain functions that contribute to learning and memory of the bee}, language = {en} } @phdthesis{NarayananNair2006, author = {Narayanan Nair, Arun Kumar}, title = {Molecular dynamics simulations of polyelectrolyte brushes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7005}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {This thesis studies strong, completely charged polyelectrolyte brushes. Extensive molecular dynamics simulations are performed on different polyelectrolyte brush systems using local compute servers and massively parallel supercomputers. The full Coulomb interaction of charged monomers, counterions, and salt ions is treated explicitly. The polymer chains are anchored by one of their ends to a uncharged planar surface. The chains are treated under good solvent conditions. Monovalent salt ions (1:1 type) are modelled same as counterions. The studies concentrate on three different brush systems at constant temperature and moderate Coulomb interaction strength (Bjerrum length equal to bond length): The first system consists of a single polyelectrolyte brush anchored with varying grafting density to a plane. Results show that chains are extended up to about 2/3 of their contour length. The brush thickness slightly grows with increasing anchoring density. This slight dependence of the brush height on grafting density is in contrast to the well known scaling result for the osmotic brush regime. That is why the result obtained by simulations has stimulated further development of theory as well as new experimental investigations on polyelectrolyte brushes. This observation can be understood on a semi-quantitative level using a simple scaling model that incorporates excluded volume effects in a free-volume formulation where an effective cross section is assigned to the polymer chain from where couterions are excluded. The resulting regime is called nonlinear osmotic brush regime. Recently this regime was also obtained in experiments. The second system studied consists of polyelectrolyte brushes with added salt in the nonlinear osmotic regime. Varying salt is an important parameter to tune the structure and properties of polyelectrolytes. Further motivation is due to a theoretical scaling prediction by Pincus for the salt dependence of brush thickness. In the high salt limit (salt concentration much larger than counterion concentration) the brush height is predicted to decrease with increasing external salt, but with a relatively weak power law showing an exponent -1/3. There is some experimental and theoretical work that confirms this prediction, but there are other results that are in contradiction. In such a situation simulations are performed to validate the theoretical prediction. The simulation result shows that brush thickness decreases with added salt, and indeed is in quite good agreement with the scaling prediction by Pincus. The relation between buffer concentration and the effective ion strength inside the brush at varying salt concentration is of interest both from theoretical as well as experimental point of view. The simulation result shows that mobile ions (counterions as well as salt) distribute nonhomogeneously inside and outside of the brush. To explain the relation between the internal ion concentration with the buffer concentration a Donnan equilibrium approach is employed. Modifying the Donnan approach by taking into account the self-volume of polyelectrolyte chains as indicated above, the simulation result can be explained using the same effective cross section for the polymer chains. The extended Donnan equilibrium relation represents a interesting theoretical prediction that should be checked by experimental data. The third system consist of two interacting polyelectrolyte brushes that are grafted to two parallel surfaces. The interactions between brushes are important, for instance, in stabilization of dispersions against flocculation. In the simulations pressure is evaluated as a function of separation D between the two grafting planes. The pressure behavior shows different regimes for decreasing separation. This behavior is in qualitative agreement with experimental data. At relatively weak compression the pressure behavior obtained in the simulation agrees with a 1/D power law predicted by scaling theory. Beyond that the present study could supply new insight for understanding the interaction between polyelectrolyte brushes.}, subject = {Molekulardynamik}, language = {en} } @article{MuessigLissoCollGarciaetal.2006, author = {M{\"u}ssig, Carsten and Lisso, Janina and Coll-Garcia, Danahe and Altmann, Thomas}, title = {Molecular analysis of brassinosteroid action}, doi = {10.1055/s-2005-873043}, year = {2006}, abstract = {Brassinosteroids (BRs) are steroidal plant hormones with important regulatory roles in various physiological processes, including growth, xylem differentiation, disease resistance, and stress tolerance. Several components of the BR signal transduction pathway have been identified. The extracellular domains of receptor kinases such as BRI1 perceive BRs and transduce the signal via intracellular kinase domains. Within the cell further kinases and phosphatases determine the phosphorylation status of transcription factors such as BES1 and BZR1. These factors mediate major BR effects. Studies of BR-regulated genes shed light on the molecular mode of BR action. Genes encoding cell-wall-modifying enzymes, enzymes of the BR biosynthetic pathway, transcription factors, and proteins involved in primary and secondary metabolism are subject to BR-regulation. Gene expression data also point at interactions with other phytohormones and a role of BR in stress responses. This article gives a survey of the BR-signaling pathway. Two BR-responsive genes, OPR3 and EXO, are described in detail}, language = {en} } @article{OcheretnijGoesselSogomonyanetal.2006, author = {Ocheretnij, Vitalij and G{\"o}ssel, Michael and Sogomonyan, Egor S. and Marienfeld, Daniel}, title = {Modulo p=3 checking for a carry select adder}, doi = {10.1007/s10836-006-6260-8}, year = {2006}, abstract = {In this paper a self-checking carry select adder is proposed. The duplicated adder blocks which are inherent to a carry select adder without error detection are checked modulo 3. Compared to a carry select adder without error detection the delay of the MSB of the sum of the proposed adder does not increase. Compared to a self-checking duplicated carry select adder the area is reduced by 20\%. No restrictions are imposed on the design of the adder blocks}, language = {en} } @misc{vondemBussche2006, type = {Master Thesis}, author = {von dem Bussche, Jens}, title = {Modelling the spatial distribution of blackbird (Turdus merula) and ring ouzel (Turdus torquatus) in Switzerland}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14012}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {To characterise the habitat preferences of ring ouzel (Turdus torquatus) and blackbird (T. merula) in Switzerland, we adopt species distribution modelling and predict the species' spatial distribution. We model on two different scales to analyse in how far downscaling leads to a different set of predictors to describe the realised habitat best. While the models on macroscale (grid of one square kilometre) cover the entire country, we select a set of smaller plots for modelling on territory scale. Whereas ring ouzels occur in altitudes above 1'000 m a.s.l. only, blackbirds occur from the lowlands up to the timber line. The altitudinal range overlap of the two species is up to 400 m. Despite both species coexist on macroscale, a direct niche overlap on territory scale is rare. Small-scale differences in vegetation cover and structure seem to play a dominant role for habitat selection. On macroscale however, we observe a high dependency on climatic variables mainly representing the altitudinal range and the related forest structure preferred by the two species. Applying the models for climate change scenarios, we predict a decline of suitable habitat for the ring ouzel with a simultaneous median altitudinal shift of +440 m until 2070. In contrast, the blackbird is predicted to benefit from higher temperatures and expand its range to higher elevations.}, language = {en} } @article{TietjenHuth2006, author = {Tietjen, Britta and Huth, Andreas}, title = {Modelling dynamics of managed tropical rainforests - An aggregated approach}, series = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, volume = {199}, journal = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2005.11.045}, pages = {421 -- 432}, year = {2006}, abstract = {The overuse of rainforests in the last century and its consequences necessitate a rethinking of logging policies. To this end models have been developed to simulate rainforest dynamics and to allow optional management strategies to be evaluated. Parameterisation of presently existing models for a certain site needs a lot of work, thus the parameterisation effort is too high to apply the models to a wide range of rainforests. Hence, in this paper we introduce the simplified model FORREG using the knowledge we have gained from a more complex model, FORMIX3-Q. The FORREG model uses differential equations to determine the volume growth of three successional species groups. Parameterisation is simplified by a genetic algorithm, which determines the required internal model parameters from characteristics of the forest dynamics. The new model is employed to assess the sustainability of various logging policies in terms of yield and damage. Results for three forests are discussed: (1) the tropical lowland rain forest in the Deramakot Forest Reserve, (2) the Lambir National Park in Malaysia and (3) a subtropical forest in Paraguay. Our model reproduces both undisturbed forest dynamics and dynamics of logged forests simulated with FORMIX3-Q very well. However, the resultant volumes of yield and damage differ slightly from those gained by FORMIX3-Q if short logging cycles are simulated. Choosing longer logging cycles leads to a good correspondence of both models. For the Deramakot Forest Reserve different logging cycles are compared and discussed. (c) 2006 Elsevier B.V. All rights reserved.}, language = {en} } @inproceedings{Thomas2006, author = {Thomas, Kavita E.}, title = {Modelling Correction Signalled by "But" in Dialogue}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10308}, year = {2006}, abstract = {Claiming that cross-speaker "but" can signal correction in dialogue, we start by describing the types of corrections "but" can communicate by focusing on the Speech Act (SA) communicated in the previous turn and address the ways in which "but" can correct what is communicated. We address whether "but" corrects the proposition, the direct SA or the discourse relation communicated in the previous turn. We will also briefly address other relations signalled by cross-turn "but". After presenting a typology of the situations "but" can correct, we will address how these corrections can be modelled in the Information State model of dialogue, motivating this work by showing how it can be used to potentially avoid misunderstandings. We wrap up by showing how the model presented here updates beliefs in the Information State representation of the dialogue and can be used to facilitate response deliberation.}, language = {en} } @article{GrellSchaubSelbig2006, author = {Grell, Susanne and Schaub, Torsten H. and Selbig, Joachim}, title = {Modelling biological networks by action languages via set programming}, issn = {0302-9743}, doi = {10.1007/11799573}, year = {2006}, language = {en} } @phdthesis{Maulbetsch2006, author = {Maulbetsch, Christian}, title = {Modeling galaxy formation in different environments}, address = {Potsdam}, pages = {IV, 138 S. : graph. Darst.}, year = {2006}, language = {en} } @inproceedings{WolskaKruijffKorbayova2006, author = {Wolska, Magdalena and Kruijff-Korbayov{\´a}, Ivana}, title = {Modeling anaphora in informal mathematical dialogue}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10455}, year = {2006}, abstract = {We analyze anaphoric phenomena in the context of building an input understanding component for a conversational system for tutoring mathematics. In this paper, we report the results of data analysis of two sets of corpora of dialogs on mathematical theorem proving. We exemplify anaphoric phenomena, identify factors relevant to anaphora resolution in our domain and extensions to the input interpretation component to support it.}, language = {en} } @book{PfauSteinbach2006, author = {Pfau, Roland and Steinbach, Markus}, title = {Modality-independent and modality-specific aspects of grammaticalization in sign languages}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-53-7}, issn = {1864-1857}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10886}, publisher = {Universit{\"a}t Potsdam}, pages = {97}, year = {2006}, abstract = {One type of internal diachronic change that has been extensively studied for spoken languages is grammaticalization whereby lexical elements develop into free or bound grammatical elements. Based on a wealth of spoken languages, a large amount of prototypical grammaticalization pathways has been identified. Moreover, it has been shown that desemanticization, decategorialization, and phonetic erosion are typical characteristics of grammaticalization processes. Not surprisingly, grammaticalization is also responsible for diachronic change in sign languages. Drawing data from a fair number of sign languages, we show that grammaticalization in visual-gestural languages - as far as the development from lexical to grammatical element is concerned - follows the same developmental pathways as in spoken languages. That is, the proposed pathways are modalityindependent. Besides these intriguing parallels, however, sign languages have the possibility of developing grammatical markers from manual and non-manual co-speech gestures. We will discuss various instances of grammaticalized gestures and we will also briefly address the issue of the modality-specificity of this phenomenon.}, language = {en} } @article{StrehmelLaschewskyStoesseretal.2006, author = {Strehmel, Veronika and Laschewsky, Andr{\´e} and Stoesser, Reinhard and Zehl, Andrea and Herrmann, Werner}, title = {Mobility of spin probes in ionic liquids}, doi = {10.1002/poc.1072}, year = {2006}, abstract = {The spin probes TEMPO, TEMPOL, and CAT-1 were used to investigate microviscosity and micropolarity of imidazolium based ionic liquids bearing either tetrafluoroborate or hexafluorophosphate as anions and a variation of the substitution at the imidazolium ion. The average rotational correlation times (r) obtained by complete simulation of the X-band ESR spectra of TEMPO, TEMPOL, and CAT-1 increase with increasing viscosity of the ionic liquid although no Stokes Einstein behavior is observed. This is caused by microviscosity effects of the ionic liquids shown by application of the Gierer-Wirtz theory. Interestingly, the jump of the probe molecule into the free volume of the ionic liquids is a nonactivated process. The hyperfine coupling constants (A(iso) (N-14)) of TEMPO and TEMPOL dissolved in the ionic liquids do not depend on the structure of the ionic liquids. The A(iso) (N-14) values show a micropolarity of the ionic liquids that is comparable with methylenchloride in case of TEMPO and with dimethylsulfoxide in case of TEMPOL. Micropolarity monitored by CAT-1 strongly depends on structural variation of the ionic liquid. CAT-1 dissolved in imidazolium salts substituted with shorter alkyl chains at the nitrogen atom exhibits a micropolarity comparable with dimethylsulfoxide. A significant lower micropolarity is found for imidazolium. salts bearing a longer alkyl substituent at the nitrogen atom or a methyl substituent at C-2. Copyright (c) 2006 John Wiley \& Sons, Ltd}, language = {en} } @misc{Wischer2006, author = {Wischer, Ilse}, title = {Miyawaki, M., James Harris's Theory of Universal Grammar: a Synthesis of the Aristotelian and Platonic Conceptions of Language; M{\"u}nster, Nodus-Publ., 2005}, year = {2006}, language = {en} } @article{KnoerichMutti2006, author = {Knoerich, Andrea Claudia and Mutti, Maria}, title = {Missing aragonitic biota and the diagenetic evolution of heterozoan carbonates : a case study from the Oligo- Miocene of the central Mediterranean}, issn = {1527-1404}, doi = {10.2110/Jsr.2006.065}, year = {2006}, abstract = {Several previous studies have addressed the diagenetic evolution of heterozoan carbonate assemblages. Generally it is assumed that early diagenetic processes in heterozoan settings are mainly destructive, including abrasion and dissolution on the sea floor. Constructive diagenesis (cementation) is delayed to later stages in the burial environment, with pressure solution of calcitic grains acting as a cement source. This paper presents a study of Oligo- Miocene inner- to outer-ramp heterozoan carbonates from the Central Mediterranean (Maltese Islands and Sicily) indicating that early diagenetic processes are more important than previously assumed. Four to five different cement types, including fibrous, two types of epitaxial, bladed and blocky cement, are distinguished based on transmitted light microscopy. Cathodoluminescence microscopy allowed a differentiation between primary high-Mg calcitic (fibrous and epitaxial cement I) and primary low-Mg calcitic (epitaxial cement II, bladed and blocky) cements. Stable-isotope data indicate cement precipitation from marine, marine-derived, and meteoric waters. Trace-element analyses point to cementation in an open system (Maltese Islands) and a closed system (Sicily). Our investigations show that the majority of constructive diagenetic processes in these rocks occurs rather early in the shallow, marine burial environment, which is transitional between the marine seafloor and the deep-burial diagenctic environment. The main cement source in this environment is assumed to be aragonite. We suggest careful consideration of the importance of aragonitic components in fossil heterozoan settings, which seem to be more abundant than previously assumed and can act as a major early cement source. Due to the low preservation potential of these components, detailed geochemical studies are necessary to detect aragonite as the cement source. Our findings also have implications when considering the reservoir qualities of these rocks, because primary porosity can be occluded early and secondary porosity is not preserved}, language = {en} } @article{LuckowSchnor2006, author = {Luckow, Andr{\´e} and Schnor, Bettina}, title = {Migol : a Fault Tolerant Service Framework for Grid Computing : Evolution to WSRF (2006)}, year = {2006}, language = {en} } @article{EngbertMergenthaler2006, author = {Engbert, Ralf and Mergenthaler, Konstantin}, title = {Microsaccades are triggered by low retinal image slip}, issn = {0027-8424}, doi = {10.1073/pnas.0509557103}, year = {2006}, abstract = {Even during visual fixation of a stationary target, our eyes perform rather erratic miniature movements, which represent a random walk. These "fixational" eye movements counteract perceptual fading, a consequence of fast adaptation of the retinal receptor systems to constant input. The most important contribution to fixational eye movements is produced by microsaccades; however, a specific function of microsaccades only recently has been found. Here we show that the occurrence of microsaccades is correlated with low retinal image slip approximate to 200 ms before microsaccade onset. This result suggests that microsaccades are triggered dynamically, in contrast to the current view that microsaccades are randomly distributed in time characterized by their rate-of-occurrence of 1 to 2 per second. As a result of the dynamic triggering mechanism, individual microsaccade rate can be predicted by the fractal dimension of trajectories. Finally, we propose a minimal computational model for the dynamic triggering of microsaccades}, language = {en} } @misc{Mangili2006, author = {Mangili, Clara}, title = {Microfacies and isotope analyses of the varved Pi{\`a}nico lake sediment profile for high-resolution reconstruction of interglacial climate dynamics}, address = {Potsdam}, pages = {VI, 91 Bl. : graph. Darst.}, year = {2006}, language = {en} } @phdthesis{Mohan2006, author = {Mohan, Ruchika}, title = {Microbial colonization of the gastrointestinal tract of preterm infants: Microbial diversity and new ways of prevention of infections}, address = {Potsdam}, pages = {VII, 102 Bl. : graph. Darst.}, year = {2006}, language = {en} } @phdthesis{Fery2006, author = {Fery, Andreas}, title = {Micro-Mechanics and Adhesion of Artifical Capsules From Method-development to Unterstanding Structure-property relations}, address = {Potsdam}, pages = {46 S. : graph. Darst.}, year = {2006}, language = {en} } @misc{TiedemannPfautsch2006, author = {Tiedemann, Ralph and Pfautsch, Simone}, title = {MHC evolution in ducks and allies}, series = {Journal of ornithology}, volume = {147}, journal = {Journal of ornithology}, number = {Supplement 1}, publisher = {Blackwell}, address = {New York}, issn = {0021-8375}, pages = {48 -- 48}, year = {2006}, language = {en} } @inproceedings{KuhnertGuentnerKlannetal.2006, author = {Kuhnert, Matthias and G{\"u}ntner, Andreas and Klann, Mechthild and Martin Garrido, F. and Zillgens, Birgit}, title = {Methods for spatial pattern comparison in distributed hydrological modelling : [Poster]}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7160}, year = {2006}, abstract = {The rigorous development, application and validation of distributed hydrological models obligates to evaluate data in a spatially distributed way. In particular, spatial model predictions such as the distribution of soil moisture, runoff generating areas or nutrient-contributing areas or erosion rates, are to be assessed against spatially distributed observations. Also model inputs, such as the distribution of modelling units derived by GIS and remote sensing analyses, should be evaluated against groundbased observations of landscape characteristics. So far, however, quantitative methods of spatial field comparison have rarely been used in hydrology. In this paper, we present algorithms that allow to compare observed and simulated spatial hydrological data. The methods can be applied for binary and categorical data on regular grids. They comprise cell-by-cell algorithms, cell-neighbourhood approaches that account for fuzziness of location, and multi-scale algorithms that evaluate the similarity of spatial fields with changing resolution. All methods provide a quantitative measure of the similarity of two maps. The comparison methods are applied in two mountainous catchments in southern Germany (Brugga, 40 km2) and Austria (L{\"o}hnersbach, 16 km2). As an example of binary hydrological data, the distribution of saturated areas is analyzed in both catchments. For categorical data, vegetation zones that are associated with different runoff generation mechanisms are analyzed in the L{\"o}hnersbach. Mapped spatial patterns are compared to simulated patterns from terrain index calculations and from satellite image analysis. It is discussed how particular features of visual similarity between the spatial fields are captured by the quantitative measures, leading to recommendations on suitable algorithms in the context of evaluating distributed hydrological models.}, language = {en} } @article{MorgenthalWeckwerthSteuer2006, author = {Morgenthal, Katja and Weckwerth, Wolfram and Steuer, Ralf}, title = {Metabolomic networks in plants : transitions from pattern recognition to biological interpretation}, doi = {10.1016/j.biosystems.2005.05.017}, year = {2006}, abstract = {Nowadays techniques for non-targeted metabolite profiling allow for the generation of huge amounts of relevant data essential for the construction of dynamic metabolomic networks. Thus, metabolomics, besides transcriptomics or proteomics, provides a major tool for the characterization of postgenomic processes. In this work, we introduce comparative correlation analysis as a complementary approach to characterize the physiological states of various organs of diverse plant species with focus on specific participation of metabolites in different reaction networks. The correlations observed are induced by diminutive fluctuations in environmental conditions, which propagate through the system and induce specific patterns depending on the genomic background. In order to examine this hypothesis, numeric examples of such fluctuations are computed and compared with experimentally obtained metabolite data.}, language = {en} } @phdthesis{Clavel2006, author = {Clavel, Thomas}, title = {Metabolism of the dietary lignan secoisolariciresinol diglucoside by human intestinal bacteria}, publisher = {Logos-Verl.}, address = {Berlin}, isbn = {3-8325-1192-X}, pages = {vii, 65 S. : Ill., graph. Darst.}, year = {2006}, language = {en} } @article{LissoAltmannMuessig2006, author = {Lisso, Janina and Altmann, Thomas and M{\"u}ssig, Carsten}, title = {Metabolic changes in fruits of the tomato d(x) mutant}, series = {Phytochemistry : an international journal of plant biochemistry}, volume = {67}, journal = {Phytochemistry : an international journal of plant biochemistry}, number = {20}, publisher = {Elsevier}, address = {Oxford}, issn = {0031-9422}, doi = {10.1016/j.phytochem.2006.07.008}, pages = {2232 -- 2238}, year = {2006}, language = {en} } @article{DeDonnoSchulze2006, author = {De Donno, Giuseppe and Schulze, Bert-Wolfgang}, title = {Meromorphic symbolic structures for boundary value problems on manifolds with edges}, issn = {0025-584X}, doi = {10.1002/mana.200310366}, year = {2006}, abstract = {We investigate the ideal of Green and Mellin operators with asymptotics for a manifold with edge-corner singularities and boundary which belongs to the structure of parametrices of elliptic boundary value problems on a configuration with corners whose base manifolds have edges.}, language = {en} } @article{HoldtMuellerKellingetal.2006, author = {Holdt, Hans-J{\"u}rgen and M{\"u}ller, Holger and Kelling, Alexandra and Drexler, Hans-Joachim and M{\"u}ller, Thomas and Schwarze, Thomas and Schilde, Uwe and Starke, Ines}, title = {Mercury(II) chloride and iodide complexes of dithia- and tetrathiacrown ethers}, issn = {0044-2313}, doi = {10.1002/zaac.200500281}, year = {2006}, abstract = {The complexes [(HgCl2)(2)((ch)(2)30S(4)O(6))] (1), [HgCl,(mn21S(2)O(5))] (2), [HgCl2(ch18S(2)O(4))] (3) and [HgI(meb12S(2)O(2))](2)[Hg2I6] (4) have been synthesized, characterized and their crystal structures were determined. In [(HgCl2)(2)((ch)(2)3OS(4)O(6))] two HgCl2 units are discretely bonded within the ligand cavity of the 30-membered dichinoxaline-tetrathia-30-crown-10 ((ch)(2)30S(4)O(6)) forming a binuclear complex. HgCl2 forms I : I "in-cavity" complexes with the 21-membered maleonitrile-dithia-21-crown-7(mn21S(2)O(5)) ligand and the 18-membered chinoxaline- dithia-18-crown-6 (ch18S(2)O(4)) ligand, respectively. The 12-membered 4-methyl-benzo-dithia-12-crown-4 (meb12S(2)O(2)) ligand gave with two equivalents HgI2 the compound [HgI(meb12S(2)O(2))](2)[Hg2I6]. In the cation [HgI(meb12S(2)O(2))](+) meb12S(2)O(2) forms with the cation HgI+ a half-sandwich complex}, language = {en} } @article{WoodPoreeDreyeretal.2006, author = {Wood, C. C. and Poree, Fabien and Dreyer, Ingo and Koehler, G. J. and Udvardi, M. K.}, title = {Mechanisms of ammonium transport, accumulation, and retention in ooyctes and yeast cells expressing Arabidopsis AtAMT1; 1}, doi = {10.1016/j.febslet.2006.06.026}, year = {2006}, abstract = {Ammonium is a primary source of N for plants, so knowing how it is transported, stored, and assimilated in plant cells is important for rational approaches to optimise N-use in agriculture. Electrophysiological studies of Arabidopsis AtAMT1;1 expressed in oocytes revealed passive, Delta psi-driven transport of NH4+ through this protein. Expression of AtAMT1;1 in a novel yeast mutant defective in endogenous ammonium transport and vacuolar acidification supported the above mechanism for AtAMT1;1 and revealed a central role for acid vacuoles in storage and retention of ammonia in cells. These results highlight the mechanistic differences between plant AMT proteins and related transporters in bacteria and animal cells, and suggest novel strategies to enhance nitrogen use efficiency in agriculture. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved}, language = {en} } @inproceedings{KranstedtLueckingPfeifferetal.2006, author = {Kranstedt, Alfred and L{\"u}cking, Andy and Pfeiffer, Thies and Rieser, Hannes and Staudacher, Marc}, title = {Measuring and reconstructing pointing in visual contexts}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10362}, year = {2006}, abstract = {We describe an experiment to gather original data on geometrical aspects of pointing. In particular, we are focusing upon the concept of the pointing cone, a geometrical model of a pointing's extension. In our setting we employed methodological and technical procedures of a new type to integrate data from annotations as well as from tracker recordings. We combined exact information on position and orientation with rater's classifications. Our first results seem to challenge classical linguistic and philosophical theories of demonstration in that they advise to separate pointings from reference.}, language = {en} } @book{Trauth2006, author = {Trauth, Martin H.}, title = {MATLAB recipes for earth sciences : with CD-ROM}, publisher = {Springer}, address = {Heidelberg}, isbn = {3-540-27983-0}, pages = {238 S.}, year = {2006}, abstract = {MATLAB is used in a wide range of applications in geosciences, such as image processing in remote sensing, generation and processing of digital elevation models and the analysis of time series. This book introduces basic methods of data analysis in geosciences using MATLAB. The text includes a brief description of each method and numerous examples on how MATLAB can be used on data sets from earth sciences. All MATLAB recipes can easily be modified in order to analyse the reader's own data sets. The book comes with a CD containing example data sets and a digital version of the MATLAB recipes.}, language = {en} } @book{Trauth2006, author = {Trauth, Martin H.}, title = {Matlab in geosciences : recipes for data analysis}, series = {MATLAB® Recipes for Earth Sciences}, journal = {MATLAB® Recipes for Earth Sciences}, publisher = {Springer-Verlag Berlin Heidelberg}, address = {Berlin, Heidelberg}, isbn = {3-540-27983-0}, doi = {10.1007/3-540-27984-9}, pages = {237 S.}, year = {2006}, abstract = {MATLAB is used in a wide range of applications in geosciences, such as image processing in remote sensing, generation and processing of digital elevation models and the analysis of time series. This book introduces basic methods of data analysis in geosciences using MATLAB. The text includes a brief description of each method and numerous examples demonstrating how MATLAB can be used on data sets from earth sciences. All MATLAB recipes can be easily modified in order to analyse the reader's own data sets. The book comes with a CD containing exemplary data sets and a digital version of the MATLAB recipes. (Springer)}, language = {en} } @article{Wischer2006, author = {Wischer, Ilse}, title = {Markers of futurity in old english and the grammaticalization of shall and will}, year = {2006}, language = {en} } @article{KorfFroeming2006, author = {Korf, Roman and Fr{\"o}ming, Jane}, title = {Mangement of knowledge intensive business processes with KMDL v2.0}, isbn = {3-936771-62-6}, year = {2006}, language = {en} } @article{AndresenGronau2006, author = {Andresen, Katja and Gronau, Norbert}, title = {Managing Change : determining the adaptability of information systems}, year = {2006}, language = {en} } @article{HerbstFuchsTeubneretal.2006, author = {Herbst, Uta and Fuchs, Iris Judith and Teubner, Wera and Steinberg, Pablo}, title = {Malignant transformation of human colon epithelial cells by benzo[c]phenanthrene dihydrodiolepoxides as well as 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine}, issn = {0041-008X}, doi = {10.1016/j.taap.2005.07.016}, year = {2006}, abstract = {Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) ingested with food have repeatedly been suggested to be involved in the malignant transformation of colon epithelial cells. In order to test this hypothesis, HCEC cells (SV40 large T antigen-immortalized human colon epithelial cells) were incubated with a racemic mixture of benzo[c]phenanthrene dihydrodiol epoxides (B[c]PhDE), extremely potent carcinogenic PAH metabolites in vivo, or with 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP), the N-hydroxylated metabolite of the most abundant HCA in cooked meat. First, it was shown that HCEC cells express sulfotransferase 1A1, which is needed to metabolize N-OH-PhIP to the corresponding N-sulfonyloxy derivative, the direct precursor molecule of genotoxic nitrenium ions. Thereafter, exponentially growing HCEC cells were exposed five times to 0.1 mu g (0.37 nmol) B[c]PhDE/ml for 30 min or 0.72 mu g (3 mnol) N-OH-PhTP/ml for 24 h. Chemically treated HCEC cells showed an enhanced saturation density and grew faster than the corresponding solvent-treated cell cultures. After five treatment cycles, HCECB[c]PhDE as well as HCECN-OH-PhIP cells lost cell-cell contact inhibition and started piling up and forming foci in the culture flasks. Furthermore, HCECB[c]phDE and HCECN-OH-PhIP cells were injected i.m. into SCID mice. Within 6 weeks after injection, eight animals out of eight injected with HCECB[c]phDE or HCECN-OH-PhIP cells developed tumors at the site of injection, thus demonstrating the high tumorigenic potential of the HCECB[c]PhDE and HCECN-OH-PhIP cell cultures. Taken together, we show for the first time that the abovementioned active PAH metabolites as well as N-OH-PhIP are indeed able to malignantly transform human colon epithelial cells in vitro.}, language = {en} } @article{Brosch2006, author = {Brosch, Renate}, title = {Making sense : sense perception in the British novel of the 1980s and 1990s}, issn = {0171-5410}, year = {2006}, language = {en} } @article{VarykhalovGudatAdamchuketal.2006, author = {Varykhalov, Andrei and Gudat, Wolfgang and Adamchuk, V. K. and Rader, Oliver}, title = {Magic numbers in two-dimensional self-organization of C-60 molecules}, doi = {10.1103/Physrevb.73.241404}, year = {2006}, abstract = {Employing the chemically passive carbon reconstruction W(110)/C-R(15x3) as substrate for deposition of C-60 molecules, we have discovered by scanning tunneling microscopy two-dimensional self-assembly of fullerenes into uniform molecular nanoclusters with "magic" numbers. Our photoemission measurements determine van der Waals forces as the dominating interaction in this self-organizing two-dimensional molecular gas. Based on this, a theoretical determination of the cluster structures in the framework of the Girifalco model gives perfect agreement with the experiment}, language = {en} } @article{VianaWackermannFurtadoEsseretal.2006, author = {Viana-Wackermann, Paula C. and Furtado, Erikson F. and Esser, G{\"u}nter and Schmidt, Martin H. and Laucht, Manfred}, title = {Lower P300 amplitude in eight-year-old offspring of alcoholic fathers with a delinquent history}, issn = {0940-1334}, doi = {10.1007/s00406-006-0709-8}, year = {2006}, abstract = {The aim of the present study was to investigate the P300 amplitude as a possible vulnerability marker in children of alcoholic (COA) fathers with and without paternal delinquency. Event-related potentials (ERPs) of 122 children aged 8 years (63 boys, 59 girls) were compared depending on father's alcoholism subtype: 30 COAs without paternal delinquency, 10 COAs with paternal delinquency, and 82 children of non-alcoholic and non-delinquent fathers. ERPs were recorded from Fz, Cz, and Pz, using an auditory oddball paradigm. Sinus tones of 60 dB HL were presented binaurally at 1,000 Hz (standard stimulus) and 2,000 Hz (target stimulus), at a relative frequency ratio of 80:20. Two trial blocks of 250 stimuli each were collected. Results indicated that only COAs with paternal delinquency displayed significant differences from the control group, characterized by reduced P300 amplitude at frontal site and in the second trial block. Thus, the combination of fathers' alcoholism and delinquency was more likely to relate to attenuated P300 amplitude in the offspring than paternal alcoholism alone. Our results suggest that both alcoholic and delinquent family history appear to play a role in P300 amplitude reduction in the offspring.}, language = {en} } @article{DonnerSeehaferSanjuanetal.2006, author = {Donner, Reik Volker and Seehafer, Norbert and Sanjuan, Miguel Angel Fernandez and Feudel, Fred}, title = {Low-dimensional dynamo modelling and symmetry-breaking bifurcations}, series = {Physica. D, Nonlinear phenomena}, volume = {223}, journal = {Physica. D, Nonlinear phenomena}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-2789}, doi = {10.1016/j.physd.2006.08.022}, pages = {151 -- 162}, year = {2006}, abstract = {Motivated by the successful Karlsruhe dynamo experiment, a relatively low-dimensional dynamo model is proposed. It is based on a strong truncation of the magnetohydrodynamic (MHD) equations with an external forcing of the Roberts type and the requirement that the model system satisfies the symmetries of the full MHD system, so that the first symmetry-breaking bifurcations can be captured. The backbone of the Roberts dynamo is formed by the Roberts flow, a helical mean magnetic field and another part of the magnetic field coupled to these two by triadic mode interactions. A minimum truncation model (MTM) containing only these energetically dominating primary mode triads is fully equivalent to the widely used first-order smoothing approximation. However, it is shown that this approach works only in the limit of small wave numbers of the excited magnetic field or small magnetic Reynolds numbers (\$Rm ll 1\$). To obtain dynamo action under more general conditions, secondary mode}, language = {en} } @article{ZuritaSanchezHenkel2006, author = {Zurita-S{\´a}nchez, Jorge R. and Henkel, Carsten}, title = {Lossy electrical transmission lines: Thermal fluctuations and quantization}, issn = {1050-2947}, doi = {10.1103/Physreva.73.063825}, year = {2006}, abstract = {We present a theoretical framework for the analysis of the statistical properties of thermal fluctuations on a lossy transmission line. A quantization scheme of the electrical signals in the transmission line is formulated. We discuss two applications in detail. Noise spectra at finite temperature for voltage and current are shown to deviate significantly from the Johnson-Nyquist limit, and they depend on the position on the transmission line. We analyze the spontaneous emission, at low temperature, of a Rydberg atom and its resonant enhancement due to vacuum fluctuations in a capacitively coupled transmission line. The theory can also be applied to study the performance of microscale and nanoscale devices, including high-resolution sensors and quantum information processors}, language = {en} } @article{DeAraujoGuentnerBronstert2006, author = {De Araujo, Jos{\`e} Carlos and G{\"u}ntner, Andreas and Bronstert, Axel}, title = {Loss of reservoir volume by sediment deposition and its impact on water availability in semiarid Brazil}, issn = {0262-6667}, doi = {10.1623/hysj.51.1.157}, year = {2006}, abstract = {A methodology is presented to assess the impact of reservoir silting oil water availability for semiarid environments, applied to seven representative watersheds in the state of Ceara, Brazil. Water yield is computed using stochastic modelling for several reliability levels and water yield reduction is quantified for the focus areas. The yield-volume elasticity concept, which indicates the relative yield reduction in terms of relative storage capacity of the reservoirs, is presented and applied. Results chow that storage capacity was reduced by 0.2\% year(-1) due to silting, that the risk of water shortage almost doubled in less than 50 years for the most critical reservoir, and that reduction of storage capacity had three times more impact oil yield reduction than the increase in evaporation. Average 90\% reliable yield-volume elasticity was 0.8, which means that the global water yield (Q(90)) in Ceara is expected to diminish yearly by 388 L s(-1) due to reservoir silting}, language = {en} } @article{MoustakasGuentherWiegandetal.2006, author = {Moustakas, Aristides and G{\"u}nther, Matthias and Wiegand, Kerstin and M{\"u}ller, Karl-Heinz and Ward, David and Meyer, Katrin M. and Jeltsch, Florian}, title = {Long-term mortality patterns of the deep-rooted Acacia erioloba}, series = {Journal of vegetation science}, volume = {17}, journal = {Journal of vegetation science}, publisher = {Blackwell}, address = {Malden}, issn = {1100-9233}, doi = {10.1111/j.1654-1103.2006.tb02468.x}, pages = {473 -- 480}, year = {2006}, abstract = {Question: Is there a relationship between size and death in the Iona-lived, deep-rooted tree, Acacia erioloba, in a semi-arid savanna? What is the size-class distribution of A. erioloba mortality? Does the mortality distribution differ from total tree size distribution? Does A. erioloba mortality distribution match the mortality distributions recorded thus far in other environments? Location: Dronfield Ranch, near Kimberley, Kalahari, South Africa. Methods: A combination of aerial photographs and a satellite image covering 61 year was used to provide long-term spatial data on mortality. We used aerial photographs of the study area from 1940, 1964, 1984, 1993 and a satellite image from 2001 to follow three plots covering 510 ha. We were able to identify and individually follow ca. 3000 individual trees from 1940 till 2001. Results: The total number of trees increased over time. No relationship between total number of trees and mean tree size was detected. There were no trends over time in total number of deaths per plot or in size distributions of dead trees. Kolmogorov-Smirnov tests showed no differences in size class distributions for living trees through time. The size distribution of dead trees was significantly different from the size distribution of all trees present on the plots. Overall, the number of dead trees was low in small size classes, reached a peak value when canopy area was 20 - 30 m(2), and declined in lamer size-classes. Mortality as a ratio of dead vs. total trees peaked at intermediate canopy sizes too. Conclusion: A. erioloba mortality was size-dependent, peaking at intermediate sizes. The mortality distribution differs from all other tree mortality distributions recorded thus far. We suggest that a possible mechanism for this unusual mortality distribution is intraspecific competition for water in this semi-arid environment.}, language = {en} } @article{ApioPlathWronski2006, author = {Apio, Ann and Plath, Martin and Wronski, Torsten}, title = {Localised defecation sites : a tactic to avoid re-infection by gastro-intestinal tract parasites in bushbuck, Tragelaphus scriptus?}, issn = {0289-0771}, doi = {10.1007/s10164-005-0166-2}, year = {2006}, abstract = {Bushbuck (Tragelaphus scriptus) often deposit faeces at specific localised defecation sites (LDS). We tested whether LDS have a function in the context of parasite avoidance. In a population of bushbuck in Queen Elizabeth National Park, Uganda, seven radio-collared individuals were observed. We recorded feeding behaviour inside and outside LDS. Furthermore, pasture contamination with gastro-intestinal tract parasites inside and outside LDS was examined. There were significant differences between the expected and the observed feeding rates inside LDS, but, contrary to our prediction, the bushbuck increased their feeding rate inside LDS. There was no significant difference in the parasite contamination of pastures inside and outside LDS. We discuss the hypothesis that LDS mainly serve a social function in bushbuck communities, whereas parasite avoidance seems to play a minor or no role}, language = {en} } @article{Reichard2006, author = {Reichard, Christoph}, title = {Local government reforms in Europe : a mini symposium}, issn = {1471-9037}, doi = {10.1080/14719030500518618}, year = {2006}, language = {en} } @article{Kuhlmann2006, author = {Kuhlmann, Sabine}, title = {Local government reform between 'exogenous' and 'endogenous' driving forces : Institution building in the city of Paris}, issn = {1471-9037}, doi = {10.1080/14719030500518790}, year = {2006}, abstract = {The article attempts to analyse institutional reforms in the multi-level system of the French capital city. The key questions are the developments in central-local relations and what factors influenced these changes over the last century. The author seeks to identify 'critical junctures' in institutional development and explore their impact on the relationships between state and municipality on the one hand and between upper and lower tiers of city- government on the other. Looking at institution building in Paris as the dependent variable the article takes a primarily institutionalist approach in identifying the relevant factors which explain local government reform in the capital city ('what shapes institutions?')}, language = {en} } @book{BrauerKarp2006, author = {Brauer, Uwe and Karp, Lavi}, title = {Local existence of classical solutions for the Einstin-Euler system using weighted Sobolev spaces of fractional order}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {12 S.}, year = {2006}, language = {en} } @unpublished{BrauerKarp2006, author = {Brauer, Uwe and Karp, Lavi}, title = {Local existence of classical solutions for the Einstein-Euler system using weighted Sobolev spaces of fractional order}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30175}, year = {2006}, abstract = {We prove the existence of a class of local in time solutions, including static solutions, of the Einstein-Euler system. This result is the relativistic generalisation of a similar result for the Euler-Poisson system obtained by Gamblin [8]. As in his case the initial data of the density do not have compact support but fall off at infinity in an appropriate manner. An essential tool in our approach is the construction and use of weighted Sobolev spaces of fractional order. Moreover, these new spaces allow us to improve the regularity conditions for the solutions of evolution equations. The details of this construction, the properties of these spaces and results on elliptic and hyperbolic equations will be presented in a forthcoming article.}, language = {en} } @article{FriedrichKrahmerSchneidenbachetal.2006, author = {Friedrich, Sven and Krahmer, Sebastian and Schneidenbach, Lars and Schnor, Bettina}, title = {Loaded: Server Load Balancing for IPv6}, isbn = {0-7695-2622-5}, year = {2006}, abstract = {With the next generation Internet protocol IPv6 at the horizon, it is time to think about how applications can migrate to IPv6. Web traffic is currently one of the most important applications in the Internet. The increasing popularity of dynamically generated content on the World Wide Web, has created the need for fast web servers. Server clustering together with server load balancing has emerged as a promising technique to build scalable web servers. The paper gives a short overview over the new features of IPv6 and different server load balancing technologies. Further, we present and evaluate Loaded, an user-space server load balancer for IPv4 and IPv6 based on Linux.}, language = {en} } @article{PedersenBrunetonMaupin2006, author = {Pedersen, Helle A. and Bruneton, Marianne and Maupin, Val{\´e}rie}, title = {Lithospheric and sublithospheric anisotropy beneath the Baltic shield from surface-wave array analysis}, doi = {10.1016/j.epsl.2006.02.009}, year = {2006}, abstract = {We report measurements of radial and azimuthal anisotropy in the tipper mantle beneath southern and central Finland, which we obtained by array analysis of fundamental-mode Rayleigh and Love waves. Azimuthally averaged phase velocities were analysed in the period range 15 to 190 s for Rayleigh waves and 15 to 100 s for Love waves. The azimuthal variation of the Rayleigh wave phase velocities was obtained in the period range 20 to 100s. The limited depth resolution of fundamental-mode surface waves necessitated strong damping constraints in the inversion for anisotropic parameters. We investigated the effects of non-unicity on the final model by experimenting with varying model geometries. The radial anisotropy beneath Finland can be explained by a lithosphere at least 200km thick, predominantly (> 50\% by volume) composed of olivine crystals having their a-axes randomly distributed in the horizontal plane. On the contrary, the measured lithospheric azimuthal anisotropy is small. This call be reconciled with body-wave observations made in the area that indicate a complex pattern of rapidly varying anisotropy. Below 200-250km depth, that is below the petrologic lithosphere as revealed by xenolith analyses conducted in the area, the magnitude of the azimuthal anisotropy increases and would be compatible with a mantle containing 15-20\% by volume of olivine crystals whose a-axes are coherently aligned in the N-NE direction. The alignment of the a-axes is off the direction of present-day absolute plate motion in either the no-net-rotation or hot-spot reference frame, currently N55-N60. We interpret this mismatch as evidence for a complex convective flow pattern of the mantle beneath the shield, which, by inference, is decoupled from the overlying lithosphere.}, language = {en} } @article{Ette2006, author = {Ette, Ottmar}, title = {Literatures without a Fixed Abode : figures of Vectorial Imagination Beyond the Dichotomies of National and World Literature}, isbn = {3-86527-289-4}, year = {2006}, language = {en} } @phdthesis{Zakrevskyy2006, author = {Zakrevskyy, Yuriy}, title = {Liquid crystallinity and alignment of ionic self-assembly complexes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10048}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {In this work the first observation of new type of liquid crystals is presented. This is ionic self-assembly (ISA) liquid crystals formed by introduction of oppositely charged ions between different low molecular tectonic units. As practically all conventional liquid crystals consist of rigid core and alkyl chains the attention is focused to the simplest case where oppositely charged ions are placed between a rigid core and alkyl tails. The aim of this work is to investigate and understand liquid crystalline and alignment properties of these materials. It was found that ionic interactions within complexes play the main role. Presence of these interactions restricts transition to isotropic phase. In addition, these interactions hold the system (like network) allowing crystallization into a single domain from aligned LC state. Alignment of these simple ISA complexes was spontaneous on a glass substrate. In order to show potentials for application perylenediimide and azobenzene containing ISA complexes have been investigated for correlations between phase behavior and their alignment properties. The best results of macroscopic alignment of perylenediimide-based ISA complexes have been obtained by zone-casting method. In the aligned films the columns of the complex align perpendicular to the phase-transition front. The obtained anisotropy (DR = 18) is thermally stable. The investigated photosensitive (azobenzene-based) ISA complexes show formation of columnar LC phases. It was demonstrated that photo alignment of such complexes was very effective (DR = 50 has been obtained). It was shown that photo-reorientation in the photosensitive ISA complexes is cooperative process. The size of domains has direct influence on efficiency of the photo-reorientation process. In the case of small domains the photo-alignment is the most effective. Under irradiation with linearly polarized light domains reorient in the plane of the film leading to macroscopic alignment of columns parallel to the light polarization and joining of small domains into big ones. Finally, the additional distinguishable properties of the ISA liquid crystalline complexes should be noted: (I) the complexes do not solve in water but readily solve in organic solvents; (II) the complexes have good film-forming properties when cast or spin-coated from organic solvent; (III) alignment of the complexes depends on their structure and secondary interactions between tectonic units.}, subject = {Fl{\"u}ssigkristall}, language = {en} } @article{TewsEstherMiltonetal.2006, author = {Tews, J{\"o}rg and Esther, Alexandra and Milton, Sue J. and Jeltsch, Florian}, title = {Linking a population model with an ecosystem model : assessing the impact of land use and climate change on savanna shrub cover dynamics}, doi = {10.1016/j.ecolmodel.2005.11.025}, year = {2006}, abstract = {In semiarid savannas of Southern Africa current land use practices and climate change may lead to substantial changes of vegetation structure in the near future, however uncertainty remains about the potential consequences and the magnitude of change. In this paper we study the impact of climate change, cattle grazing, and wood cutting on shrub cover dynamics in savannas of the southern Kalahari. We use an established savanna ecosystem model to simulate landscape dynamics in terms of rainfall, fire and distribution of the dominant tree Acacia erioloba. We then incorporate these data into a spatial population model of the common, fleshy-fruited shrub Grewia flava and investigate shrub cover dynamics for a period of 100 years. Depending on the intensity of commercial wood cutting practices tree removal of A. erioloba led to a strong decline of the G. flava population, as shrub recruitment is concentrated in tree sub-canopies due to bird-mediated seed dispersal. Under climate change shrub cover slightly decreased with decreasing precipitation and was unchanged with increase in precipitation variability. Contrarily, grazing by cattle strongly increased shrub cover and facilitated shrub encroachment because of cattle-induced distribution of G. flava seeds into the matrix vegetation. Knowledge of the latter process is particularly important because shrub invasion is a major concern for conservation and savanna rangeland management as a result of its adverse effects on livestock carrying capacity and biodiversity}, language = {en} } @article{Reich2006, author = {Reich, Sebastian}, title = {Linearly implicit time stepping methods for numerical weather prediction}, series = {BIT : numerical mathematics ; the leading applied mathematics journal for all computational mathematicians}, volume = {46}, journal = {BIT : numerical mathematics ; the leading applied mathematics journal for all computational mathematicians}, publisher = {Springer}, address = {Dordrecht}, issn = {0006-3835}, doi = {10.1007/s10543-006-0065-0}, pages = {607 -- 616}, year = {2006}, abstract = {The efficient time integration of the dynamic core equations for numerical weather prediction (NWP) remains a key challenge. One of the most popular methods is currently provided by implementations of the semi-implicit semi-Lagrangian (SISL) method, originally proposed by Robert (J. Meteorol. Soc. Jpn., 1982). Practical implementations of the SISL method are, however, not without certain shortcomings with regard to accuracy, conservation properties and stability. Based on recent work by Gottwald, Frank and Reich (LNCSE, Springer, 2002), Frank, Reich, Staniforth, White and Wood (Atm. Sci. Lett., 2005) and Wood, Staniforth and Reich (Atm. Sci. Lett., 2006) we propose an alternative semi-Lagrangian implementation based on a set of regularized equations and the popular Stormer-Verlet time stepping method in the context of the shallow-water equations (SWEs). Ultimately, the goal is to develop practical implementations for the 3D Euler equations that overcome some or all shortcomings of current SISL implementations.}, language = {en} } @article{FrankMooreReich2006, author = {Frank, Jason and Moore, Brian E. and Reich, Sebastian}, title = {Linear PDEs and numerical methods that preserve a multisymplectic conservation law}, issn = {1064-8275}, doi = {10.1137/050628271}, year = {2006}, abstract = {Multisymplectic methods have recently been proposed as a generalization of symplectic ODE methods to the case of Hamiltonian PDEs. Their excellent long time behavior for a variety of Hamiltonian wave equations has been demonstrated in a number of numerical studies. A theoretical investigation and justification of multisymplectic methods is still largely missing. In this paper, we study linear multisymplectic PDEs and their discretization by means of numerical dispersion relations. It is found that multisymplectic methods in the sense of Bridges and Reich [Phys. Lett. A, 284 ( 2001), pp. 184-193] and Reich [J. Comput. Phys., 157 (2000), pp. 473-499], such as Gauss-Legendre Runge-Kutta methods, possess a number of desirable properties such as nonexistence of spurious roots and conservation of the sign of the group velocity. A certain CFL-type restriction on Delta t/Delta x might be required for methods higher than second order in time. It is also demonstrated by means of the explicit midpoint method that multistep methods may exhibit spurious roots in the numerical dispersion relation for any value of Delta t/Delta x despite being multisymplectic in the sense of discrete variational mechanics [J. E. Marsden, G. P. Patrick, and S. Shkoller, Commun. Math. Phys., 199 (1999), pp. 351-395]}, language = {en} } @article{BubeNetoDonneretal.2006, author = {Bube, Kevin and Neto, Camilo Rodrigues and Donner, Reik Volker and Schwarz, Udo and Feudel, Ulrike}, title = {Linear and nonlinear characterization of surfaces from a laser beam melt ablation process}, issn = {0022-3727}, doi = {10.1088/0022-3727/39/7/011}, year = {2006}, abstract = {We apply linear and nonlinear methods to study the properties of surfaces generated by a laser beam melt ablation process. As a result we present a characterization and ordering of the surfaces depending on the adjusted process parameters. Our findings give some insight into the performance of two widely applied multifractal analysis methods-the detrended fluctuation analysis and the wavelet transform modulus maxima method-on short real world data}, language = {en} } @article{ToblerSchluppHeubeletal.2006, author = {Tobler, Michael and Schlupp, Ingo and Heubel, Katja U. and Riesch, Rudiger and Garcia de Leon, Francisco J. and Giere, Olav and Plath, Martin}, title = {Life on the edge: hydrogen sulfide and the fish communities of a Mexican cave and surrounding waters}, series = {Extremophiles : life under extreme conditions}, volume = {10}, journal = {Extremophiles : life under extreme conditions}, publisher = {Springer}, address = {Tokyo}, issn = {1431-0651}, doi = {10.1007/s00792-006-0531-2}, pages = {577 -- 585}, year = {2006}, abstract = {Most eucaryotic organisms classified as living in an extreme habitat are invertebrates. Here we report of a fish living in a Mexican cave (Cueva del Azufre) that is rich in highly toxic H2S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our study revealed high concentrations of H2S in the cave and its outflow (El Azufre). The concentrations of H2S reach more than 300 mu M inside the cave, which are acutely toxic for most fishes. In both sulfidic habitats, the diversity of fishes was heavily reduced, and Poecilia mexicana was the dominant species indicating that the presence of H2S has an all-or-none effect, permitting only few species to survive in sulfidic habitats. Compared to habitats without H2S, P. mexicana from the cave and the outflow have a significantly lower body condition. Although there are microhabitats with varying concentrations of H2S within the cave, we could not find a higher fish density in areas with lower concentrations of H2S. We discuss that P. mexicana is one of the few extremophile vertebrates. Our study supports the idea that extreme habitats lead to an impoverished species diversity.}, language = {en} } @article{PetruTielboergerBelkinetal.2006, author = {Petru, Martina and Tielb{\"o}rger, Katja and Belkin, Ruthie and Sternberg, Marcelo and Jeltsch, Florian}, title = {Life history variation in an annual plant under two opposing environmental constraints along an aridity gradient}, doi = {10.1111/j.2005.0906-7590.04310.x}, year = {2006}, abstract = {Environmental gradients represent an ideal framework for studying adaptive variation in the life history of plant species. However, on very steep gradients, largely contrasting conditions at the two gradient ends often limit the distribution of the same species across the whole range of environmental conditions. Here, we study phenotypic variation in a winter annual crucifer Biscutella didyma persisting along a steep gradient of increasing rainfall in Israel. In particular, we explored whether the life history at the arid end of the gradient indicates adaptations to drought and unpredictable conditions, while adaptations to the highly competitive environment prevail at the mesic Mediterranean end. We examined several morphological and reproductive traits in four natural populations and in populations cultivated in standard common environment. Plants from arid environments were faster in phenological development, more branched in architecture and tended to maximize reproduction, while the Mediterranean plants invested mainly in vertical vegetative growth. Differences between cultivation and field in diaspore production were very large for arid populations as opposed to Mediterranean ones, indicating a larger potential to increase reproduction under favorable conditions. Our overall findings indicate two strongly opposing selective forces at the two extremes of the aridity gradient, which result in contrasting strategies within the studied annual plant species}, language = {en} } @phdthesis{Popp2006, author = {Popp, Steffen}, title = {Late Quaternary Environment of Central Yakuutia (NE{\"i} Siberia): Signals in Frozen Ground and Terrestrial Sediments}, address = {Potsdam}, pages = {85 S. : graph. Darst.}, year = {2006}, language = {en} } @article{SobelChenHeermance2006, author = {Sobel, Edward and Chen, Jie and Heermance, Richard V.}, title = {Late Oligocene-Early Miocene initiation of shortening in the Southwestern Chinese Tian Shan : implications for Neogene shortening rate variations}, doi = {10.1016/j.epsl.2006.03.048}, year = {2006}, abstract = {The Cenozoic Tian Shan is one of the preeminent examples of an intracontinental orogen. However, there remains a significant controversy over when deformation related to the India-Asia collision commenced and therefore how shortening within the mountains has been partitioned over time. One approach has been to look at the modem shortening rate as measured by geodetic studies, combined with estimates of the total shortening across the range and extrapolate backwards. This approach suggests that the onset of range construction was ca. 10 Ma [K.Y. Abdrakhmatov, S.A. Aldazhanov, B.H. Hager, M.W Hamburger, T.A. Herring, K.B. Kalabaev, K.B. Kalabayev, V.I. Makarov, P. Molnar, S.V Panasyuk, M.T. Prilepin, R.E. Reilinger, I.S. Sadybakasov, B.J. Souter, Y.A. Trapeznikov, V.Y. Tsurkov, A.V. Zubovich, Relatively recent construction of the Tien Shan inferred from GPS measurements of present-day crustal deformation rates, Nature 384 (6608) (1996) 450-453]. An alternate method is to determine the age of the onset of exhumation using thermochronology. We present 19 new apatite fission-track (AFT) results from the southwestern Chinese portion of the belt; this region represents the first area exhumed during the late Tertiary along a transect at ca. 76 degrees E. Exhumation commenced at the Oligocene-Miocene boundary (similar to 24 Ma) along the Maidan and Muziduke thrusts, which bound the southern side of the Kokshaal range. Subsequently, deformation propagated ca. 20 km south to the Kashi basin- bounding thrust (KBT), which was exhumed by no earlier than 18.9 +/- 3.3 Ma. Three detrital AFT samples from Plio- Pleistocene strata deposited ca. 20 km farther south contain fission track grain age peaks that young monotonically upwards from 20.9 + 7.0/- 5.3 Ma to 15.9 + 5.4/- 4.0 Ma with a fairly constant lag time of 16 to 18 Ma. These ages, combined with structural data, suggest that both the hanging wall and the footwall of the KBT experienced a renewed episode of exhumation during the latest Cenozoic. The discrepancy between the Late Oligocene-Miocene initiation of significant exhumation shown herein and the 10 Ma initiation estimate from geodesy suggests that the Tian Shan has undergone a complex Late Cenozoic shortening history. Assuming that the present shortening rate could account for the total amount of Cenozoic shortening in 10 Ma and realizing that shortening initiated at least 15 Myr earlier, we conclude that the shortening rate must have varied over time, possibly in pulsed-southward migrating events, and that the present rate may not reflect the average rate since initiation of range uplift. (c) 2006 Elsevier B.V. All rights reserved}, language = {en} } @article{Grimshwa2006, author = {Grimshwa, Jane}, title = {Last resorts and grammaticality}, series = {Linguistics in Potsdam}, journal = {Linguistics in Potsdam}, number = {25}, issn = {1616-7392}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32302}, pages = {33 -- 41}, year = {2006}, abstract = {A "last resort" is argued to be nothing more than a winning, i.e. grammatical form, once it is understood in terms of competition between alternative candidates. It is a theorem of OT that we find last resort effects, since it follows from the nature of competition and constraint interaction.}, language = {en} } @article{RaabWesselSchirdewanetal.2006, author = {Raab, Corinna and Wessel, Niels and Schirdewan, Alexander and Kurths, J{\"u}rgen}, title = {Large-scale dimension densities for heart rate variability analysis}, issn = {1539-3755}, doi = {10.1103/Physreve.73.041907}, year = {2006}, abstract = {In this work, we reanalyze the heart rate variability (HRV) data from the 2002 Computers in Cardiology (CiC) Challenge using the concept of large-scale dimension densities and additionally apply this technique to data of healthy persons and of patients with cardiac diseases. The large-scale dimension density (LASDID) is estimated from the time series using a normalized Grassberger-Procaccia algorithm, which leads to a suitable correction of systematic errors produced by boundary effects in the rather large scales of a system. This way, it is possible to analyze rather short, nonstationary, and unfiltered data, such as HRV. Moreover, this method allows us to analyze short parts of the data and to look for differences between day and night. The circadian changes in the dimension density enable us to distinguish almost completely between real data and computer-generated data from the CiC 2002 challenge using only one parameter. In the second part we analyzed the data of 15 patients with atrial fibrillation (AF), 15 patients with congestive heart failure (CHF), 15 elderly healthy subjects (EH), as well as 18 young and healthy persons (YH). With our method we are able to separate completely the AF (rho(mu)(ls)=0.97 +/- 0.02) group from the others and, especially during daytime, the CHF patients show significant differences from the young and elderly healthy volunteers (CHF, 0.65 +/- 0.13; EH, 0.54 +/- 0.05; YH, 0.57 +/- 0.05; p < 0.05 for both comparisons). Moreover, for the CHF patients we find no circadian changes in rho(mu)(ls) (day, 0.65 +/- 0.13; night, 0.66 +/- 0.12; n.s.) in contrast to healthy controls (day, 0.54 +/- 0.05; night, 0.61 +/- 0.05; p=0.002). Correlation analysis showed no statistical significant relation between standard HRV and circadian LASDID, demonstrating a possibly independent application of our method for clinical risk stratification}, language = {en} } @phdthesis{Hildebrandt2006, author = {Hildebrandt, Niko}, title = {Lanthanides and quantum dots : time-resolved laser spectroscopy of biochemical F{\"o}rster Resonance Energy Transfer (FRET) systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12686}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {F{\"o}rster Resonance Energy Transfer (FRET) plays an important role for biochemical applications such as DNA sequencing, intracellular protein-protein interactions, molecular binding studies, in vitro diagnostics and many others. For qualitative and quantitative analysis, FRET systems are usually assembled through molecular recognition of biomolecules conjugated with donor and acceptor luminophores. Lanthanide (Ln) complexes, as well as semiconductor quantum dot nanocrystals (QD), possess unique photophysical properties that make them especially suitable for applied FRET. In this work the possibility of using QD as very efficient FRET acceptors in combination with Ln complexes as donors in biochemical systems is demonstrated. The necessary theoretical and practical background of FRET, Ln complexes, QD and the applied biochemical models is outlined. In addition, scientific as well as commercial applications are presented. FRET can be used to measure structural changes or dynamics at distances ranging from approximately 1 to 10 nm. The very strong and well characterized binding process between streptavidin (Strep) and biotin (Biot) is used as a biomolecular model system. A FRET system is established by Strep conjugation with the Ln complexes and QD biotinylation. Three Ln complexes (one with Tb3+ and two with Eu3+ as central ion) are used as FRET donors. Besides the QD two further acceptors, the luminescent crosslinked protein allophycocyanin (APC) and a commercial fluorescence dye (DY633), are investigated for direct comparison. FRET is demonstrated for all donor-acceptor pairs by acceptor emission sensitization and a more than 1000-fold increase of the luminescence decay time in the case of QD reaching the hundred microsecond regime. Detailed photophysical characterization of donors and acceptors permits analysis of the bioconjugates and calculation of the FRET parameters. Extremely large F{\"o}rster radii of more than 100 {\AA} are achieved for QD as acceptors, considerably larger than for APC and DY633 (ca. 80 and 60 {\AA}). Special attention is paid to interactions with different additives in aqueous solutions, namely borate buffer, bovine serum albumin (BSA), sodium azide and potassium fluoride (KF). A more than 10-fold limit of detection (LOD) decrease compared to the extensively characterized and frequently used donor-acceptor pair of Europium tris(bipyridine) (Eu-TBP) and APC is demonstrated for the FRET system, consisting of the Tb complex and QD. A sub-picomolar LOD for QD is achieved with this system in azide free borate buffer (pH 8.3) containing 2 \% BSA and 0.5 M KF. In order to transfer the Strep-Biot model system to a real-life in vitro diagnostic application, two kinds of imunnoassays are investigated using human chorionic gonadotropin (HCG) as analyte. HCG itself, as well as two monoclonal anti-HCG mouse-IgG (immunoglobulin G) antibodies are labeled with the Tb complex and QD, respectively. Although no sufficient evidence for FRET can be found for a sandwich assay, FRET becomes obvious in a direct HCG-IgG assay showing the feasibility of using the Ln-QD donor-acceptor pair as highly sensitive analytical tool for in vitro diagnostics.}, language = {en} } @article{Hassler2006, author = {Haßler, Gerda}, title = {Klaus D. Dutz (1953-2006) y Peter Schmitter (1943-2006)}, year = {2006}, language = {en} } @article{HeinmuellerPetitjeanLedouxetal.2006, author = {Heinm{\"u}ller, Janine and Petitjean, Patrick and Ledoux, Cedric and Caucci, Sara and Srianand, Raghunathan}, title = {Kinematics and star formation activity in the z(abs)=2.03954 damped Lyman-alpha system towards PKS 0458-020}, issn = {0004-6361}, doi = {10.1051/0004-6361:20053910}, year = {2006}, abstract = {We present UVES observations of the log N(H I) = 21.7 damped Lyman-alpha system at z(abs) = 2.03954 towards the quasar PKS 0458-020. Hi Lyman-alpha emission is detected in the center of the damped Lyman-alpha absorption trough. Metallicities are derived for Mg II, Si II, P II, Cr II, Mn II, Fe II and Zn II and are found to be -1.21 +/- 0.12, - 1.28 +/- 0.20, -1.54 +/- 0.11, -1.66 +/- 0.10, -2.05 +/- 0.11, -1.87 +/- 0.11, -1.22 +/- 0.10, respectively, relative to solar. The depletion factor is therefore of the order of [Zn/Fe] = 0.65. We observe metal absorption lines to be blueshifted compared to the Lyman-alpha emission up to a maximum of similar to 100 and 200 km s(-1) for low and high- ionization species respectively. This can be interpreted either as the consequence of rotation in a large (similar to 7 kpc) disk or as the imprint of a galactic wind. The star formation rate (SFR) derived from the Lyman-alpha emission, 1.6 M-circle dot yr(-1), is compared with that estimated from the observed C II* absorption. No molecular hydrogen is detected in our data, yielding a molecular fraction log f < -6.52. This absence of H-2 can be explained as the consequence of a high ambient UV flux which is one order of magnitude larger than the radiation field in the ISM of our Galaxy and originates in the observed emitting region}, language = {en} } @article{SiefertPeinke2006, author = {Siefert, Malte and Peinke, J}, title = {Joint multi-scale statistics of longitudinal and transversal increments in small-scale wake turbulence}, doi = {10.1080/14685240600677673}, year = {2006}, abstract = {We analyse the relationship of longitudinal and transversal increment statistics measured in isotropic small- scale turbulence. This is done by means of the theory of Markov processes leading to a phenomenological Fokker - Planck equation for the two increments from which a generalized K arm an equation is derived. We discuss in detail the analysis and show that the estimated equation can describe the statistics of the turbulent cascade. A remarkable result is that the main differences between longitudinal and transversal increments can be explained by a simple rescaling symmetry, namely the cascade speed of the transverse increments is 1.5 times faster than that of the longitudinal increments. Small differences can be found in the skewness and in a higher order intermittency term. The rescaling symmetry is compatible with the Kolmogorov constants and the K arm an equation and gives new insight into the use of extended self- similarity (ESS) for transverse increments. Based on the results we propose an extended self-similarity for the transverse increments (ESST)}, language = {en} } @article{BoeckmannKirsche2006, author = {B{\"o}ckmann, Christine and Kirsche, Andreas}, title = {Iterative regularization method for lidar remote sensing}, issn = {0010-4655}, doi = {10.1016/j.cpc.2005.12.019}, year = {2006}, abstract = {In this paper we present an inversion algorithm for ill-posed problems arising in atmospheric remote sensing. The proposed method is an iterative Runge-Kutta type regularization method. Those methods are better well known for solving differential equations. We adapted them for solving inverse ill-posed problems. The numerical performances of the algorithm are studied by means of simulations concerning the retrieval of aerosol particle size distributions from lidar observations.}, language = {en} } @article{BordihnFernauHolzeretal.2006, author = {Bordihn, Henning and Fernau, Henning and Holzer, Markus and Manca, Vincenzo and Martin-Vide, Carlos}, title = {Iterated sequential transducers as language generating devices}, series = {Theoretical computer science}, volume = {369}, journal = {Theoretical computer science}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-3975}, doi = {10.1016/j.tcs.2006.07.059}, pages = {67 -- 81}, year = {2006}, abstract = {Iterated finite state sequential transducers are considered as language generating devices. The hierarchy induced by the size of the state alphabet is proved to collapse to the fourth level. The corresponding language families are related to the families of languages generated by Lindenmayer systems and Chomsky grammars. Finally, some results on deterministic and extended iterated finite state transducers are established.}, language = {en} } @misc{LauSalffnerLoehmannsroeben2006, author = {Lau, Steffen and Salffner, Katharina and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {Isotopic resolution of carbon monoxide and carbon dioxide by NIR diode laser spectroscopy}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10135}, year = {2006}, abstract = {Near-infrared (NIR) absorption spectroscopy with tunable diode lasers allows the simultaneous detection of the three most important isotopologues of carbon dioxide (12CO2, 13CO2, 12C18O16O) and carbon monoxide (12CO, 13CO, 12C18O). The flexible and compact fiber-optic tunable diode laser absorption spectrometer (TDLAS) allows selective measurements of CO2 and CO with high isotopic resolution without sample preparation since there is no interference with water vapour. For each species, linear calibration plots with a dynamic range of four orders of magnitude and detection limits (LOD) in the range of a few ppm were obtained utilizing wavelength modulation spectroscopy (WMS) with balanced detection in a Herriott-type multipass cell. The high performance of the apparatus is illustrated by fill-evacuation-refill cycles.}, subject = {Isotop}, language = {en} } @article{MichalskiGautschiBurkartetal.2006, author = {Michalski, S and Gautschi, B and Burkart, Michael and Durka, Walter}, title = {Isolation and characterization of microsatellite loci in the rush Juncus atratus (Juncaceae)}, year = {2006}, language = {en} } @article{Oberauer2006, author = {Oberauer, Klaus}, title = {Is the focus of attention in working memory expanded through practice?}, doi = {10.1037/0278-7393.32.2.197}, year = {2006}, abstract = {This article reinvestigates the claim by P. Verhaeghen, J. Cerella, and C. Basak (2004) that the focus of attention in working memory can be expanded from 1 to 4 items through practice. Using a modified version of Verhaeghen et al.'s n-back paradigm, Experiments 1 and 3 show that a signature of a one-item focus, the time cost for switching between items in working memory, persists over practice. Verhaeghen et al. reported a shift over practice from a step function to a linear slope of reaction times over set size and argued that it reflects the expansion of the focus. With an improved counterbalancing scheme, a continuously increasing slope was found even without practice in Experiment 2. The results question the hypothesis that the focus is expanded through practice. They are in line with predictions from a model that distinguishes a one-item focus from a direct-access region holding about 4 items}, language = {en} } @article{KirkKallen2006, author = {Kirk, John M. and Kallen, Jeffrey L.}, title = {Irish standard English}, series = {The Celtic Englishes IV : the interface between English and the Celtic languages ; proceedings of the fourth international colloquium on the "Celtic Englishes" held at the University of Potsdam in Golm (Germany) from 22-26 September 2004}, journal = {The Celtic Englishes IV : the interface between English and the Celtic languages ; proceedings of the fourth international colloquium on the "Celtic Englishes" held at the University of Potsdam in Golm (Germany) from 22-26 September 2004}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40948}, pages = {88 -- 113}, year = {2006}, abstract = {Content: 1. Introduction 2. ICE-Ireland and the Irish Language 3. Grammatical Features 3.1. Perfective Aspect 3.2. Reflexive Pronouns 3.3. Inversion and Embedded Clauses 4. Conclusion}, language = {en} } @article{Bobda2006, author = {Bobda, Augustin Simo}, title = {Irish presence in colonial Cameroon and its linguistic legacy}, series = {The Celtic Englishes IV : the interface between English and the Celtic languages ; proceedings of the fourth international colloquium on the "Celtic Englishes" held at the University of Potsdam in Golm (Germany) from 22-26 September 2004}, journal = {The Celtic Englishes IV : the interface between English and the Celtic languages ; proceedings of the fourth international colloquium on the "Celtic Englishes" held at the University of Potsdam in Golm (Germany) from 22-26 September 2004}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41011}, pages = {217 -- 233}, year = {2006}, abstract = {Content: 1. Survey of Foreign Influences on English in Cameroon 1.1. Early Foreign Influences in the Formation of English in Cameroon 1.2. Later Influences 2. Irish Linguistic Legacy 2.1. Language Policy 2.2. Structural Aspects of English}, language = {en} } @article{BeitzLaudienLoehmannsroebenetal.2006, author = {Beitz, Toralf and Laudien, Robert and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Kallies, Bernd}, title = {Ion mobility spectrometric investigation of aromatic cations in the gas phase}, issn = {1089-5639}, doi = {10.1021/Jp055335n}, year = {2006}, abstract = {In this work, ion mobility (IM) spectra of more than 50 aromatic compounds were recorded with a laser-based IM spectrometer at atmospheric pressure. IM spectra of PAH in the laser desorption experiment show a high complexity resulting from the occurrence of monomeric, dimeric, and oligomeric cluster ions. The mobilities of all compounds were determined in helium as drift gas. This allows the calculation of the diffusion cross sections (Omega(calc)) on the basis of the exact hard sphere scattering model and their comparison with the experimentally determined diffusion cross sections (Omega(exp)). Extended Omega(exp)/Omega(calc) and Omega(exp/)mass correlations were performed in order to gain insight into conformational properties of cationic alkyl benzenes and internal rotation of phenyl rings in aromatic ions. This is demonstrated with some examples, such as the evaluation of the dihedral angle of the ions of 9,10- diphenylanthracene, o- and m-terphenyl, and 1,2,3- and 1,3,5-triphenylbenzene. Furthermore, sandwich and T-structures of dimeric PAH cations are discussed. The analysis was extended to oligomeric ions with up to nine monomer units. Experimental evidence is presented suggesting the formation of pi-stacks with a transition toward modified pi-stacks with increasing cluster size. The distance between monomeric units in dimeric and oligomeric ions was obtained}, language = {en} } @article{IryuMatsudaMachiyamaetal.2006, author = {Iryu, Yasufumi and Matsuda, Hiroki and Machiyama, Hideaki and Piller, Werner E. and Quinn, Terrence M. and Mutti, Maria}, title = {Introductory perspective on the COREF project}, series = {The island arc : official journal of the Geological Society of Japan}, volume = {15}, journal = {The island arc : official journal of the Geological Society of Japan}, number = {4}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1038-4871}, doi = {10.1111/j.1440-1738.2006.00537.x}, pages = {393 -- 406}, year = {2006}, abstract = {Coral reefs are tropic to subtropic, coastal ecosystems comprising very diverse organisms. Late Quaternary reef deposits are fossil archives of environmental, tectonic and eustatic variations that can be used to reconstruct the paleoclimatic and paleoceano-graphic history of the tropic surface oceans. Reefs located at the latitudinal limits of coral-reef ecosystems (i.e. those at coral-reef fronts) are particularly sensitive to environmental changes-especially those associated with glacial-interglacial changes in climate and sealevel. We propose a land and ocean scientific drilling campaign in the Ryukyu Islands (the Ryukyus) in the northwestern Pacific Ocean to investigate the dynamic response of the corals and coral-reef ecosystems in this region to Late Quaternary climate and sealevel change. Such a drilling campaign, which we call the COREF (coral-reef front) Project, will allow the following three major questions to be evaluated: (i) What are the nature, magnitude and driving mechanisms of coral-reef front migration in the Ryukyus? (ii) What is the ecosystem response of coral reefs in the Ryukyus to Quaternary climate changes? (iii) What is the role of coral reefs in the global carbon cycle? Subsidiary objectives include (i) the timing of coral-reef initiation in the Ryukyus and its causes; (ii) the position of the Kuroshio current during glacial periods and its effects on coral-reef formation; and (iii) early carbonate diagenetic responses as a function of compounded variations in climate, eustacy and depositional mineralogies (subtropic aragonitic to warm-temperate calcitic). The geographic, climatic and oceanographic settings of the Ryukyu Islands provide an ideal natural laboratory to address each of these research questions.}, language = {en} } @article{HainzlZoellerMain2006, author = {Hainzl, Sebastian and Z{\"o}ller, Gert and Main, Ian}, title = {Introduction to special issue: Dynamics of seismicity patterns and earthquake triggering - Preface}, series = {Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth}, volume = {424}, journal = {Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth}, number = {Special issue}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0040-1951}, doi = {10.1016/j.tecto.2006.03.034}, pages = {135 -- 138}, year = {2006}, language = {en} } @phdthesis{Prevot2006, author = {Prevot, Michelle Elizabeth}, title = {Introduction of a thermo-sensitive non-polar species into polyelectrolyte multilayer capsules for drug delivery}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7785}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {The layer-by-layer assembly (LBL) of polyelectrolytes has been extensively studied for the preparation of ultrathin films due to the versatility of the build-up process. The control of the permeability of these layers is particularly important as there are potential drug delivery applications. Multilayered polyelectrolyte microcapsules are also of great interest due to their possible use as microcontainers. This work will present two methods that can be used as employable drug delivery systems, both of which can encapsulate an active molecule and tune the release properties of the active species. Poly-(N-isopropyl acrylamide), (PNIPAM) is known to be a thermo-sensitive polymer that has a Lower Critical Solution Temperature (LCST) around 32oC; above this temperature PNIPAM is insoluble in water and collapses. It is also known that with the addition of salt, the LCST decreases. This work shows Differential Scanning Calorimetry (DSC) and Confocal Laser Scanning Microscopy (CLSM) evidence that the LCST of the PNIPAM can be tuned with salt type and concentration. Microcapsules were used to encapsulate this thermo-sensitive polymer, resulting in a reversible and tunable stimuli- responsive system. The encapsulation of the PNIPAM inside of the capsule was proven with Raman spectroscopy, DSC (bulk LCST measurements), AFM (thickness change), SEM (morphology change) and CLSM (in situ LCST measurement inside of the capsules). The exploitation of the capsules as a microcontainer is advantageous not only because of the protection the capsules give to the active molecules, but also because it facilitates easier transport. The second system investigated demonstrates the ability to reduce the permeability of polyelectrolyte multilayer films by the addition of charged wax particles. The incorporation of this hydrophobic coating leads to a reduced water sensitivity particularly after heating, which melts the wax, forming a barrier layer. This conclusion was proven with Neutron Reflectivity by showing the decreased presence of D2O in planar polyelectrolyte films after annealing creating a barrier layer. The permeability of capsules could also be decreased by the addition of a wax layer. This was proved by the increase in recovery time measured by Florescence Recovery After Photobleaching, (FRAP) measurements. In general two advanced methods, potentially suitable for drug delivery systems, have been proposed. In both cases, if biocompatible elements are used to fabricate the capsule wall, these systems provide a stable method of encapsulating active molecules. Stable encapsulation coupled with the ability to tune the wall thickness gives the ability to control the release profile of the molecule of interest.}, subject = {Mikrokapsel}, language = {en} } @article{JakupecMeiervanCuong2006, author = {Jakupec, Viktor and Meier, Bernd and van Cuong, Nguyen}, title = {International trends in building teaching curriculum and the relations to the upper secondary curriculum in Viet Nam}, year = {2006}, language = {en} } @phdthesis{Meyer2006, author = {Meyer, Ina}, title = {International consumption patterns and climate change : a socioeconomic analysis of private car demand and associated CO2 emission}, series = {Dissertation Premium}, volume = {1180}, journal = {Dissertation Premium}, publisher = {dissertation.de}, address = {Berlin}, isbn = {3-86624-080-5}, pages = {iv, 160 S. : graph. Darst.}, year = {2006}, language = {en} } @book{OPUS4-1195, title = {Interdisciplinary studies on information structure : ISIS ; Working papers of the SFB 632 - Vol. 5}, editor = {Ishihara, Shinichiro and Schmitz, Michaela and Schwarz, Anne}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-4725}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13047}, publisher = {Universit{\"a}t Potsdam}, pages = {221}, 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{HaberlandRietbrockLangeetal.2006, author = {Haberland, Christian and Rietbrock, Andreas and Lange, Dietrich and Bataille, Klaus and Hofmann, S.}, title = {Interaction between forearc and oceanic plate at the south-central Chilean margin as seen in local seismic data}, series = {Geophysical research letters}, volume = {33}, journal = {Geophysical research letters}, number = {23}, publisher = {Union}, address = {Washington}, issn = {0094-8276}, doi = {10.1029/2006GL028189}, pages = {5}, year = {2006}, abstract = {We installed a dense, amphibious, temporary seismological network to study the seismicity and structure of the seismogenic zone in southern Chile between 37° and 39°S, the nucleation area of the great 1960 Chile earthquake. 213 local earthquakes with 14.754 onset times were used for a simultaneous inversion for the 1-D velocity model and precise earthquake locations. Relocated artificial shots suggest an accuracy of the earthquake hypocenter of about 1 km (horizontally) and 500 m (vertically). Crustal events along trench-parallel and transverse, deep-reaching faults reflect the interseismic transpressional deformation of the forearc crust due to the subduction of the Nazca plate. The transverse faults seems to accomplish differential lateral stresses between subduction zone segments. Many events situated in an internally structured, planar seismicity patch at 20 to 40 km depth near the coast indicate a stress concentration at the plate's interface at 38°S which might in part be induced by the fragmented forearc structure.}, language = {en} } @phdthesis{Nolte2006, author = {Nolte, Marc}, title = {Integration of freestanding polyelectrolyte multilayer membranes in larger scale structures}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7355}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {Ultrathin, semi-permeable membranes are not only essential in natural systems (membranes of cells or organelles) but they are also important for applications (separation, filtering) in miniaturized devices. Membranes, integrated as diffusion barriers or filters in micron scale devices need to fulfill equivalent requirements as the natural systems, in particular mechanical stability and functionality (e.g. permeability), while being only tens of nm in thickness to allow fast diffusion times. Promising candidates for such membranes are polyelectrolyte multilayers, which were found to be mechanically stable, and variable in functionality. In this thesis two concepts to integrate such membranes in larger scale structures were developed. The first is based on the directed adhesion of polyelectrolyte hollow microcapsules. As a result, arrays of capsules were created. These can be useful for combinatorial chemistry or sensing. This concept was expanded to couple encapsulated living cells to the surface. The second concept is the transfer of flat freestanding multilayer membranes to structured surfaces. We have developed a method that allows us to couple mm2 areas of defect free film with thicknesses down to 50 nm to structured surfaces and to avoid crumpling of the membrane. We could again use this technique to produce arrays of micron size. The freestanding membrane is a diffusion barrier for high molecular weight molecules, while small molecules can pass through the membrane and thus allows us to sense solution properties. We have shown also that osmotic pressures lead to membrane deflection. That could be described quantitatively.}, subject = {Polyelektrolyt}, language = {en} } @article{PaascheTronickeHolligeretal.2006, author = {Paasche, Hendrik and Tronicke, Jens and Holliger, Klaus and Green, Alan G. and Maurer, Hansruedi}, title = {Integration of diverse physical-property models : subsurface zonation and petrophysical parameter estimation based on fuzzy c-means cluster analyses}, doi = {10.1190/1.2192927}, year = {2006}, abstract = {Inversions of an individual geophysical data set can be highly nonunique, and it is generally difficult to determine petrophysical parameters from geophysical data. We show that both issues can be addressed by adopting a statistical multiparameter approach that requires the acquisition, processing, and separate inversion of two or more types of geophysical data. To combine information contained in the physical-property models that result from inverting the individual data sets and to estimate the spatial distribution of petrophysical parameters in regions where they are known at only a few locations. we demonstrate the potential of the fuzzy c-means (FCM) clustering technique. After testing this new approach on synthetic data, we apply it to limited crosshole georadar, crosshole seismic, gamma-log, and slug-test data acquired within a shallow alluvial aquifer. The derived multiparameter model effectively outlines the major sedimentary units observed in numerous boreholes and provides plausible estimates for the spatial distributions of gamma-ray emitters and hydraulic conductivity}, language = {en} } @inproceedings{ZeilingerMuttiStreckeretal.2006, author = {Zeilinger, Gerold and Mutti, Maria and Strecker, Manfred and Rehak, Katrin and Bookhagen, Bodo and Schwab, Marco}, title = {Integration of digital elevation models and satellite images to investigate geological processes.}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7063}, year = {2006}, abstract = {In order to better understand the geological boundary conditions for ongoing or past surface processes geologists face two important questions: 1) How can we gain additional knowledge about geological processes by analyzing digital elevation models (DEM) and satellite images and 2) Do these efforts present a viable approach for more efficient research. Here, we will present case studies at a variety of scales and levels of resolution to illustrate how we can substantially complement and enhance classical geological approaches with remote sensing techniques. Commonly, satellite and DEM based studies are being used in a first step of assessing areas of geologic interest. While in the past the analysis of satellite imagery (e.g. Landsat TM) and aerial photographs was carried out to characterize the regional geologic characteristics, particularly structure and lithology, geologists have increasingly ventured into a process-oriented approach. This entails assessing structures and geomorphic features with a concept that includes active tectonics or tectonic activity on time scales relevant to humans. In addition, these efforts involve analyzing and quantifying the processes acting at the surface by integrating different remote sensing and topographic data (e.g. SRTM-DEM, SSM/I, GPS, Landsat 7 ETM, Aster, Ikonos…). A combined structural and geomorphic study in the hyperarid Atacama desert demonstrates the use of satellite and digital elevation data for assessing geological structures formed by long-term (millions of years) feedback mechanisms between erosion and crustal bending (Zeilinger et al., 2005). The medium-term change of landscapes during hundred thousands to millions years in a more humid setting is shown in an example from southern Chile. Based on an analysis of rivers/watersheds combined with landscapes parameterization by using digital elevation models, the geomorphic evolution and change in drainage pattern in the coastal Cordillera can be quantified and put into the context of seismotectonic segmentation of a tectonically active region. This has far-reaching implications for earthquake rupture scenarios and hazard mitigation (K. Rehak, see poster on IMAF Workshop). Two examples illustrate short-term processes on decadal, centennial and millennial time scales: One study uses orogen scale precipitation gradients derived from remotely sensed passive microwave data (Bookhagen et al., 2005a). They demonstrate how debris flows were triggered as a response of slopes to abnormally strong rainfall in the interior parts of the Himalaya during intensified monsoons. The area of the orogen that receives high amounts of precipitation during intensified monsoons also constitutes numerous landslide deposits of up to 1km3 volume that were generated during intensified monsoon phase at about 27 and 9 ka (Bookhagen et al., 2005b). Another project in the Swiss Alps compared sets of aerial photographs recorded in different years. By calculating high resolution surfaces the mass transport in a landslide could be reconstructed (M. Schwab, Universit{\"a}t Bern). All these examples, although representing only a short and limited selection of projects using remote sense data in geology, have as a common approach the goal to quantify geological processes. With increasing data resolution and new sensors future projects will even enable us to recognize more patterns and / or structures indicative of geological processes in tectonically active areas. This is crucial for the analysis of natural hazards like earthquakes, tsunamis and landslides, as well as those hazards that are related to climatic variability. The integration of remotely sensed data at different spatial and temporal scales with field observations becomes increasingly important. Many of presently highly populated places and increasingly utilized regions are subject to significant environmental pressure and often constitute areas of concentrated economic value. Combined remote sensing and ground-truthing in these regions is particularly important as geologic, seismicity and hydrologic data may be limited here due to the recency of infrastructural development. Monitoring ongoing processes and evaluating the remotely sensed data in terms of recurrence of events will greatly enhance our ability to assess and mitigate natural hazards.
Dokument 1: Foliensatz | Dokument 2: Abstract
Interdisziplin{\"a}res Zentrum f{\"u}r Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006}, language = {en} } @article{HattermannKrysanovaHabecketal.2006, author = {Hattermann, Fred and Krysanova, Valentina and Habeck, Anja and Bronstert, Axel}, title = {Integrating wetlands and riparian zones in river basin modelling}, series = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, volume = {199}, journal = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2005.06.012}, pages = {379 -- 392}, year = {2006}, abstract = {Wetlands, and in particular riparian wetlands, represent an interface between the catchment area and the aquatic environment. They control the exchange of water and related chemical fluxes from the upper catchment area to surface waters like streams and lakes. Their influence on water and nutrient balances has been investigated mainly at the patch scale. In this study an attempt was made (a) to integrate riparian zones and wetlands into eco-hydrological river basin modelling, and (b) to quantify the impacts of riparian wetland processes on water and nutrient fluxes in a meso-scale catchment located in the northeastern German lowland. The investigation was performed by analysing hydro-chemical field data and applying the eco-hydrological model SWIM (Soil and Water Integrated Model), which was extended to reproduce the relevant water and nutrient flows and retention processes at the catchment scale in general, and in riparian zones and wetlands in particular. The main extensions introduced in the model were: (1) implementation of daily groundwater table dynamics at the hydrotope level, (2) implementation of water and nutrient uptake by plants from groundwater in riparian zones and wetlands, and (3) assessment of nutrient retention in groundwater and interflow. The simulation results indicate that wetlands, though they represent relatively small parts of the total catchment area, may have a significant impact on the overall water and nutrient balances of the catchment. The uncertainty of the simulation results is considerably high, with the main sources of uncertainty being the model parameters representing the geo-hydrology and the input data for land use management. (c) 2006 Elsevier B.V. All rights reserved.}, language = {en} } @phdthesis{Post2006, author = {Post, Joachim}, title = {Integrated process-based simulation of soil carbon dynamics in river basins under present, recent past and future environmental conditions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11507}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {Soils contain a large amount of carbon (C) that is a critical regulator of the global C budget. Already small changes in the processes governing soil C cycling have the potential to release considerable amounts of CO2, a greenhouse gas (GHG), adding additional radiative forcing to the atmosphere and hence to changing climate. Increased temperatures will probably create a feedback, causing soils to release more GHGs. Furthermore changes in soil C balance impact soil fertility and soil quality, potentially degrading soils and reducing soils function as important resource. Consequently the assessment of soil C dynamics under present, recent past and future environmental conditions is not only of scientific interest and requires an integrated consideration of main factors and processes governing soil C dynamics. To perform this assessment an eco-hydrological modelling tool was used and extended by a process-based description of coupled soil carbon and nitrogen turnover. The extended model aims at delivering sound information on soil C storage changes beside changes in water quality, quantity and vegetation growth under global change impacts in meso- to macro-scale river basins, exemplary demonstrated for a Central European river basin (the Elbe). As a result this study: ▪ Provides information on joint effects of land-use (land cover and land management) and climate changes on croplands soil C balance in the Elbe river basin (Central Europe) presently and in the future. ▪ Evaluates which processes, and at what level of process detail, have to be considered to perform an integrated simulation of soil C dynamics at the meso- to macro-scale and demonstrates the model's capability to simulate these processes compared to observations. ▪ Proposes a process description relating soil C pools and turnover properties to readily measurable quantities. This reduces the number of model parameters, enhances the comparability of model results to observations, and delivers same performance simulating long-term soil C dynamics as other models. ▪ Presents an extensive assessment of the parameter and input data uncertainty and their importance both temporally and spatially on modelling soil C dynamics. For the basin scale assessments it is estimated that croplands in the Elbe basin currently act as a net source of carbon (net annual C flux of 11 g C m-2 yr-1, 1.57 106 tons CO2 yr-1 entire croplands on average). Although this highly depends on the amount of harvest by-products remaining on the field. Future anticipated climate change and observed climate change in the basin already accelerates soil C loss and increases source strengths (additional 3.2 g C m-2 yr-1, 0.48 106 tons CO2 yr-1 entire croplands). But anticipated changes of agro-economic conditions, translating to altered crop share distributions, display stronger effects on soil C storage than climate change. Depending on future use of land expected to fall out of agricultural use in the future (~ 30 \% of croplands area as "surplus" land), the basin either considerably looses soil C and the net annual C flux to the atmosphere increases (surplus used as black fallow) or the basin converts to a net sink of C (sequestering 0.44 106 tons CO2 yr-1 under extensified use as ley-arable) or reacts with decrease in source strength when using bioenergy crops. Bioenergy crops additionally offer a considerable potential for fossil fuel substitution (~37 PJ, 1015 J per year), whereas the basin wide use of harvest by-products for energy generation has to be seen critically although offering an annual energy potential of approximately 125 PJ. Harvest by-products play a central role in soil C reproduction and a percentage between 50 and 80 \% should remain on the fields in order to maintain soil quality and fertility. The established modelling tool allows quantifying climate, land use and major land management impacts on soil C balance. New is that the SOM turnover description is embedded in an eco-hydrological river basin model, allowing an integrated consideration of water quantity, water quality, vegetation growth, agricultural productivity and soil carbon changes under different environmental conditions. The methodology and assessment presented here demonstrates the potential for integrated assessment of soil C dynamics alongside with other ecosystem services under global change impacts and provides information on the potentials of soils for climate change mitigation (soil C sequestration) and on their soil fertility status.}, subject = {Kohlenstoff}, language = {en} } @article{KrolJaegerBronstertetal.2006, author = {Krol, Maarten and Jaeger, Annekathrin and Bronstert, Axel and G{\"u}ntner, Andreas}, title = {Integrated modelling of climate, water, soil, agricultural and socio-economic processes: A general introduction of the methodology and some exemplary results from the semi-arid north-east of Brazil}, series = {Journal of hydrology}, volume = {328}, journal = {Journal of hydrology}, number = {3-4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2005.12.021}, pages = {417 -- 431}, year = {2006}, abstract = {Many semi-arid regions are characterised by water scarcity and vulnerability of natural resources, pronounced climatic variability and social stress. Integrated studies including climatotogy, hydrology, and socio-econornic studies are required both for analysing the dynamic natural conditions and to assess possible strategies to make semi-arid regions Less vulnerable to the present and changing climate. The model introduced here dynamically describes the retationships between climate forcing, water availability, agriculture and selected societal processes. The model has been tailored to simulate the rather complex situation in the semi-and north-eastern Brazil in a quantitative manner including the sensitivity to external forcing, such as climate change. The selected results presented show the general functioning of the integrated model, with a primary focus on climate change impacts. It becomes evident that due to Large differences in regional climate scenarios, it is still impossible to give quantitative values for the most probable development, e.g., to assign probabilities to the simulated results. However, it becomes clear that water is a very crucial factor, and that an efficient and ecologically sound water management is a key question for the further development of that semi-arid region. The simulation results show that, independent of the differences in climate change scenarios, rain-fed farming is more vulnerable to drought impacts compared to irrigated farming. However, the capacity of irrigation and other water infrastructure systems to enhance resilience in respect to climatic fluctuations is significantly constrained given a significant negative precipitation trend. (c) 2005 Elsevier B.V. All rights reserved.}, language = {en} } @article{DialloKuleshHolschneideretal.2006, author = {Diallo, Mamadou Sanou and Kulesh, Michail and Holschneider, Matthias and Kurennaya, Kristina and Scherbaum, Frank}, title = {Instantaneous polarization attributes based on an adaptive approximate covariance method}, series = {Geophysics}, volume = {71}, journal = {Geophysics}, number = {5}, publisher = {SEG}, address = {Tulsa}, issn = {0016-8033}, doi = {10.1190/1.2227522}, pages = {V99 -- V104}, year = {2006}, abstract = {We introduce a method for computing instantaneous-polarization attributes from multicomponent signals. This is an improvement on the standard covariance method (SCM) because it does not depend on the window size used to compute the standard covariance matrix. We overcome the window-size problem by deriving an approximate analytical formula for the cross-energy matrix in which we automatically and adaptively determine the time window. The proposed method uses polarization analysis as applied to multicomponent seismic by waveform separation and filtering.}, language = {en} } @article{SinghDaniSharmaetal.2006, author = {Singh, Jasbir and Dani, Harinder M. and Sharma, Reeta and Steinberg, Pablo}, title = {Inhibition of the biosynthesis of SRP polypeptides and secretory proteins by aflatoxin B-1 can disrupt protein targeting}, series = {Cell biochemistry and function}, volume = {24}, journal = {Cell biochemistry and function}, publisher = {Wiley}, address = {Chichester}, issn = {0263-6484}, doi = {10.1027/cbf.1285}, pages = {507 -- 510}, year = {2006}, abstract = {Cell culture and western blotting studies revealed that aflatoxin B-1 (AFB(1)) inhibits the biosynthesis of two of the constituent polypeptides of signal recognition particle (SRP) (SRP54 and 72). SRP escorts polyribosomes carrying signal peptides from free form in the cytosol to the bound form on endoplasmic reticulum (ER) membrane during protein targeting. These effects of AFB(1) on SRP biosynthesis may inhibit the formation of functional SRP Our experiments have further shown that AFB(1) also inhibits the biosynthesis/translocation of a secretory protein, preprolactin, which fails to appear in the lumen of ER consequent to the treatment with this hepatocarcinogen. The results of the experiments presented in this article therefore enable us to infer for the first time that aflatoxin B-1 may inhibit the functioning of SRP as an escort and deplete the ER of polyribosomes for secretory protein synthesis. As these secretory proteins are important components of the plasma membrane, gap junctions and intercellular matrix, their absence from these locations could disturb cell to cell communication leading to tumorigenesis.}, language = {en} } @misc{TenFreyhausHuntgeburthWingleretal.2006, author = {Ten Freyhaus, Henrik and Huntgeburth, Michael and Wingler, Kirstin and Baeumer, A. T. and Wartenberg, Maria and Sauer, H. and Bekhite, Mohamed M. and Rosenkranz, S.}, title = {Inhibition of ROS liberation by the novel nox inhibitor VAS2870 attenuates PDGF-dependent src activation and chemotaxis, but not proliferation in vascular smooth muscle cells}, series = {European heart journal}, volume = {27}, journal = {European heart journal}, publisher = {Oxford University Press}, address = {Oxford}, issn = {0195-668X}, pages = {965 -- 965}, year = {2006}, language = {en} } @misc{tenFreyhausHuntgeburthWingeretal.2006, author = {ten Freyhaus, Henrik and Huntgeburth, Michael and Winger, Kirstin and B{\"a}umer, Anselm T. and Vantler, Marius and Bekhite, Mohamed M. and Wartenberg, Maria and Sauer, Heinrich and Sparwel, Jan and Rosenkranz, Stephan}, title = {Inhibition of ROS liberation attenuates PDGF-Dependent chemotaxis, but not proliferation in vascular smooth muscle cells - Critical role of Src kinase}, series = {Circulation : an American Heart Association journal}, volume = {114}, journal = {Circulation : an American Heart Association journal}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0009-7322}, pages = {296 -- 297}, year = {2006}, language = {en} } @article{BaptistaZhouKurths2006, author = {Baptista, Murilo da Silva and Zhou, Changsong and Kurths, J{\"u}rgen}, title = {Information transmission in phase synchronous chaotic arrays}, issn = {0256-307X}, doi = {10.1088/0256-307X/23/3/010}, year = {2006}, abstract = {We show many versatile phase synchronous configurations that emerge in an array of coupled chaotic elements due to the presence of a periodic stimulus. Then, we explain the relevance of these configurations to the understanding of how information about such a. stimulus is transmitted from one side to the other in this array. The stimulus actively creates the ways to be transmitted, by making the chaotic elements to phase synchronize}, language = {en} } @article{LoewBogdanoffHerrmannetal.2006, author = {Loew, Noya and Bogdanoff, Peter and Herrmann, Iris and Wollenberger, Ursula and Scheller, Frieder W. and Katterle, Martin}, title = {Influence of modifications on the efficiency of pyrolysed CoTMPP as electrode material for horseradish peroxidase and the reduction of hydrogen peroxide}, series = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis}, volume = {18}, journal = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis}, number = {23}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1040-0397}, doi = {10.1002/elan.200603664}, pages = {2324 -- 2330}, year = {2006}, abstract = {A tailor-made horseradish peroxidase (HRP) bulk composite electrode was developed on the basis of pyrolyzed cobalt tetramethoxyphenylporphyrin (CoTMPP) by modifying pore size and surface area of the porous carbon material through varying amounts of iron oxalate and sulfur prior to pyrolyzation. The materials were used to immobilize horseradish peroxidase (HRP). These electrodes were characterized in terms of their efficiency to reduce hydrogen peroxide. The heterogeneous electron transfer rate constants of different materials were determined with the rotating disk electrode method and a k(S) (401 +/- 61 s(-1)) exceeding previously reported values for native HRP was found.}, language = {en} } @phdthesis{Note2006, author = {Note, Carine}, title = {Influence of hydrophobically modified polyelectrolytes on nanoparticle synthesis in self-organized systems and in water}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11670}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {The formation of colloids by the controlled reduction, nucleation, and growth of inorganic precursor salts in different media has been investigated for more than a century. Recently, the preparation of ultrafine particles has received much attention since they can offer highly promising and novel options for a wide range of technical applications (nanotechnology, electrooptical devices, pharmaceutics, etc). The interest derives from the well-known fact that properties of advanced materials are critically dependent on the microstructure of the sample. Control of size, size distribution and morphology of the individual grains or crystallites is of the utmost importance in order to obtain the material characteristics desired. Several methods can be employed for the synthesis of nanoparticles. On the one hand, the reduction can occur in diluted aqueous or alcoholic solutions. On the other hand, the reduction process can be realized in a template phase, e.g. in well-defined microemulsion droplets. However, the stability of the nanoparticles formed mainly depends on their surface charge and it can be influenced with some added protective components. Quite different types of polymers, including polyelectrolytes and amphiphilic block copolymers, can for instance be used as protecting agents. The reduction and stabilization of metal colloids in aqueous solution by adding self-synthesized hydrophobically modified polyelectrolytes were studied in much more details. The polymers used are hydrophobically modified derivatives of poly(sodium acrylate) and of maleamic acid copolymers as well as the commercially available branched poly(ethyleneimine). The first notable result is that the polyelectrolytes used can act alone as both reducing and stabilizing agent for the preparation of gold nanoparticles. The investigation was then focused on the influence of the hydrophobic substitution of the polymer backbone on the reduction and stabilization processes. First of all, the polymers were added at room temperature and the reduction process was investigated over a longer time period (up to 8 days). In comparison, the reduction process was realized faster at higher temperature, i.e. 100°C. In both cases metal nanoparticles of colloidal dimensions can be produced. However, the size and shape of the individual nanoparticles mainly depends on the polymer added and the temperature procedure used. In a second part, the influence of the prior mentioned polyelectrolytes was investigated on the phase behaviour as well as on the properties of the inverse micellar region (L2 phase) of quaternary systems consisting of a surfactant, toluene-pentanol (1:1) and water. The majority of the present work has been made with the anionic surfactant sodium dodecylsulfate (SDS) and the cationic surfactant cetyltrimethylammonium bromide (CTAB) since they can interact with the oppositely charged polyelectrolytes and the microemulsions formed using these surfactants present a large water-in-oil region. Subsequently, the polymer-modified microemulsions were used as new templates for the synthesis of inorganic particles, ranging from metals to complex crystallites, of very small size. The water droplets can indeed act as nanoreactors for the nucleation and growth of the particles, and the added polymer can influence the droplet size, the droplet-droplet interactions, as well as the stability of the surfactant film by the formation of polymer-surfactant complexes. One further advantage of the polymer-modified microemulsions is the possibility to stabilize the primary formed nanoparticles via a polymer adsorption (steric and/or electrostatic stabilization). Thus, the polyelectrolyte-modified nanoparticles formed can be redispersed without flocculation after solvent evaporation.}, subject = {Mikroemulsion}, language = {en} } @unpublished{RoellyFradon2006, author = {Roelly, Sylvie and Fradon, Myriam}, title = {Infinite system of Brownian balls : equilibrium measures are canonical Gibbs}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6720}, year = {2006}, abstract = {We consider a system of infinitely many hard balls in Rd undergoing Brownian motions and submitted to a smooth pair potential. It is modelized by an infinite-dimensional stochastic differential equation with a local time term. We prove that the set of all equilibrium measures, solution of a detailed balance equation, coincides with the set of canonical Gibbs measures associated to the hard core potential added to the smooth interaction potential.}, language = {en} } @phdthesis{Treplin2006, author = {Treplin, Simone}, title = {Inference of phylogenetic relationships in passerine birds (Aves: Passeriformes) using new molecular markers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11230}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {The aim of this study was to provide deeper insights in passerine phylogenetic relationships using new molecular markers. The monophyly of the largest avian order Passeriformes (~59\% of all living birds) and the division into its suborders suboscines and oscines are well established. Phylogenetic relationships within the group have been extremely puzzling, as most of the evolutionary lineages originated through rapid radiation. Numerous studies have hypothesised conflicting passerine phylogenies and have repeatedly stimulated further research with new markers. In the present study, I used three different approaches to contribute to the ongoing phylogenetic debate in Passeriformes. I investigated the recently introduced gene ZENK for its phylogenetic utility for passerine systematics in combination and comparison to three already established nuclear markers. My phylogenetic analyses of a comprehensive data set yielded highly resolved, consistent and strongly supported trees. I was able to show the high utility of ZENK for elucidating phylogenetic relationships within Passeriformes. For the second and third approach, I used chicken repeat 1 (CR1) retrotransposons as phylogenetic markers. I presented two specific CR1 insertions as apomorphic characters, whose presence/absence pattern significantly contributed to the resolution of a particular phylogenetic uncertainty, namely the position of the rockfowl species Picathartes spp. in the passerine tree. Based on my results, I suggest a closer relationship of these birds to crows, ravens, jays, and allies. For the third approach, I showed that CR1 sequences contain phylogenetic signal and investigated their applicability in more detail. In this context, I screened for CR1 elements in different passerine birds, used sequences of several loci to construct phylogenetic trees, and evaluated their reliability. I was able to corroborate existing hypotheses and provide strong evidence for some new hypotheses, e.g. I suggest a revision of the taxa Corvidae and Corvinae as vireos are closer related to crows, ravens, and allies. The subdivision of the Passerida into three superfamilies, Sylvioidea, Passeroidea, and Muscicapoidea was strongly supported. I found evidence for a split within Sylvioidea into two clades, one consisting of tits and the other comprising warblers, bulbuls, laughingthrushes, whitethroats, and allies. Whereas Passeridae appear to be paraphyletic, monophyly of weavers and estrild finches as a separate clade was strongly supported. The sister taxon relationships of dippers and the thrushes/flycatcher/chat assemblage was corroborated and I suggest a closer relationship of waxwings and kinglets to wrens, tree-creepers, and nuthatches.}, language = {en} } @article{SchulzThierbachVoigtetal.2006, author = {Schulz, Tim Julius and Thierbach, Ren{\`e} and Voigt, Anja and Drewes, Gunnar and Mietzner, Brun and Steinberg, Pablo and Pfeiffer, Andreas F. H. and Ristow, Michael}, title = {Induction of oxidative metabolism by mitochondrial frataxin inhibits cancer growth : Otto Warburg revisited}, doi = {10.1074/jbc.M511064200}, year = {2006}, abstract = {More than 80 years ago Otto Warburg suggested that cancer might be caused by a decrease in mitochondrial energy metabolism paralleled by an increase in glycolytic flux. In later years, it was shown that cancer cells exhibit multiple alterations in mitochondrial content, structure, function, and activity. We have stably overexpressed the Friedreich ataxia-associated protein frataxin in several colon cancer cell lines. These cells have increased oxidative metabolism, as shown by concurrent increases in aconitase activity, mitochondrial membrane potential, cellular respiration, and ATP content. Consistent with Warburg's hypothesis, we found that frataxin-overexpressing cells also have decreased growth rates and increased population doubling times, show inhibited colony formation capacity in soft agar assays, and exhibit a reduced capacity for tumor formation when injected into nude mice. Furthermore, overexpression of frataxin leads to an increased phosphorylation of the tumor suppressor p38 mitogen-activated protein kinase, as well as decreased phosphorylation of extracellular signal-regulated kinase. Taken together, these results support the view that an increase in oxidative metabolism induced by mitochondrial frataxin may inhibit cancer growth in mammals}, language = {en} } @article{WiggeringDalchowGlemnitzetal.2006, author = {Wiggering, Hubert and Dalchow, Claus and Glemnitz, Michael and Helming, Katharina and M{\"u}ller, Klaus and Schultz, Alfred and Stachow, Ulrich and Zander, Peter}, title = {Indicators for multifunctional land use : linking socio-economic requirements with landscape potentials}, year = {2006}, abstract = {Indicators to assess sustainable land development often focus on either economic or ecologic aspects of landscape use. The concept of multifunctional land use helps merging those two focuses by emphasising on the rule that economic action is per se accompanied by ecological utility: commodity outputs (CO, e.g., yields) are paid for on the market, but non-commodity outputs (NCO, e.g., landscape aesthetics) so far are public goods with no markets. Agricultural production schemes often provided both outputs by joint production, but with technical progress under prevailing economic pressure, joint production increasingly vanishes by decoupling of commodity from non-commodity production. Simultaneously, by public and political awareness of these shortcomings, there appears a societal need or even demand for some non-commodity outputs of land use, which induces a market potential, and thus, shift towards the status of a commodity outputs. An approach is presented to merge both types of output by defining an indicator of social utility (SUMLU): production schemes are considered with respect to social utility of both commodity and non-commodity outputs. Social utility in this sense includes environmental and economic services as long as society expresses a demand for them. For each combination of parameters at specific frame conditions (e.g., soil and climate properties of a landscape) a production possibility curve can reflect trade-offs between commodity and non-commodity outputs. On each production possibility curve a welfare optimum can be identified expressing the highest achievable value of social utility as a trade-off between CO and NCO production. When applying more parameters, a cluster of welfare optimums is generated. Those clusters can be used for assessing production schemes with respect to sustainable land development. Examples of production possibility functions are given on easy applicable parameters (nitrogen leaching versus gross margin) and on more complex ones (biotic integrity). Social utility, thus allows to evaluate sustainability of land development in a cross-sectoral approach with respect to multifunctionality. (C) 2005 Elsevier Ltd. All rights reserved}, language = {en} }