@book{AbrahamssonBaddooMargariaetal.2007, author = {Abrahamsson, Pekka and Baddoo, Nathan and Margaria, Tiziana and Messnarz, Richard}, title = {Software Process Improvement : 14th europea conference, EuroSpi 2007, Potsdam, Germany, September 26-28, 2007 ; Proceedings}, series = {Lecture Notes in Computer Science}, volume = {4764}, journal = {Lecture Notes in Computer Science}, publisher = {Springer}, address = {Berlin}, pages = {223 S.}, year = {2007}, language = {en} } @phdthesis{Adelhelm2007, author = {Adelhelm, Philipp}, title = {Novel carbon materials with hierarchical porosity : templating strategies and advanced characterization}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15053}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {The aim of this work was the generation of carbon materials with high surface area, exhibiting a hierarchical pore system in the macro- and mesorange. Such a pore system facilitates the transport through the material and enhances the interaction with the carbon matrix (macropores are pores with diameters > 50 nm, mesopores between 2 - 50 nm). Thereto, new strategies for the synthesis of novel carbon materials with designed porosity were developed that are in particular useful for the storage of energy. Besides the porosity, it is the graphene structure itself that determines the properties of a carbon material. Non-graphitic carbon materials usually exhibit a quite large degree of disorder with many defects in the graphene structure, and thus exhibit inherent microporosity (d < 2nm). These pores are traps and oppose reversible interaction with the carbon matrix. Furthermore they reduce the stability and conductivity of the carbon material, which was undesired for the proposed applications. As one part of this work, the graphene structures of different non-graphitic carbon materials were studied in detail using a novel wide-angle x-ray scattering model that allowed precise information about the nature of the carbon building units (graphene stacks). Different carbon precursors were evaluated regarding their potential use for the synthesis shown in this work, whereas mesophase pitch proved to be advantageous when a less disordered carbon microstructure is desired. By using mesophase pitch as carbon precursor, two templating strategies were developed using the nanocasting approach. The synthesized (monolithic) materials combined for the first time the advantages of a hierarchical interconnected pore system in the macro- and mesorange with the advantages of mesophase pitch as carbon precursor. In the first case, hierarchical macro- / mesoporous carbon monoliths were synthesized by replication of hard (silica) templates. Thus, a suitable synthesis procedure was developed that allowed the infiltration of the template with the hardly soluble carbon precursor. In the second case, hierarchical macro- / mesoporous carbon materials were synthesized by a novel soft-templating technique, taking advantage of the phase separation (spinodal decomposition) between mesophase pitch and polystyrene. The synthesis also allowed the generation of monolithic samples and incorporation of functional nanoparticles into the material. The synthesized materials showed excellent properties as an anode material in lithium batteries and support material for supercapacitors.}, language = {en} } @phdthesis{AhmadAbadi2007, author = {Ahmad Abadi, Mohammad}, title = {Development and application of novel genetic transformation technologies in maize (Zea mays L.)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14572}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Plant genetic engineering approaches are of pivotal importance to both basic and applied research. However, rapid commercialization of genetically engineered crops, especially maize, raises several ecological and environmental concerns largely related to transgene flow via pollination. In most crops, the plastid genome is inherited uniparentally in a maternal manner. Consequently, a trait introduced into the plastid genome would not be transferred to the sexually compatible relatives of the crops via pollination. Thus, beside its several other advantages, plastid transformation provides transgene containment, and therefore, is an environmentally friendly approach for genetic engineering of crop plants. Reliable in vitro regeneration systems allowing repeated rounds of regeneration are of utmost importance to development of plastid transformation technologies in higher plants. While being the world's major food crops, cereals are among the most difficult-to-handle plants in tissue culture which severely limits genetic engineering approaches. In maize, immature zygotic embryos provide the predominantly used material for establishing regeneration-competent cell or callus cultures for genetic transformation experiments. The procedures involved are demanding, laborious and time consuming and depend on greenhouse facilities. In one part of this work, a novel tissue culture and plant regeneration system was developed that uses maize leaf tissue and thus is independent of zygotic embryos and greenhouse facilities. Also, protocols were established for (i) the efficient induction of regeneration-competent callus from maize leaves in the dark, (ii) inducing highly regenerable callus in the light, and (iii) the use of leaf-derived callus for the generation of stably transformed maize plants. Furthermore, several selection methods were tested for developing a plastid transformation system in maize. However, stable plastid transformed maize plants could not be yet recovered. Possible explanations as well as suggestions for future attempts towards developing plastid transformation in maize are discussed. Nevertheless, these results represent a first essential step towards developing chloroplast transformation technology for maize, a method that requires multiple rounds of plant regeneration and selection to obtain genetically stable transgenic plants. In order to apply the newly developed transformation system towards metabolic engineering of carotenoid biosynthesis, the daffodil phytoene synthase (PSY) gene was integrated into the maize genome. The results illustrate that expression of a recombinant PSY significantly increases carotenoid levels in leaves. The beta-carotene (pro-vitamin A) amounts in leaves of transgenic plants were increased by ~21\% in comparison to the wild-type. These results represent evidence for maize to have significant potential to accumulate higher amounts of carotenoids, especially beta-carotene, through transgenic expression of phytoene synthases. Finally, progresses were made towards developing transformation technologies in Peperomia (Piperaceae) by establishing an efficient leaf-based regeneration system. Also, factors determining plastid size and number in Peperomia, whose species display great interspecific variation in chloroplast size and number per cell, were investigated. The results suggest that organelle size and number are regulated in a tissue-specific manner rather than in dependency on the plastid type. Investigating plastid morphology in Peperomia species with giant chloroplasts, plasmatic connections between chloroplasts (stromules) were observed under the light microscope and in the absence of tissue fixation or GFP overexpression demonstrating the relevance of these structures in vivo. Furthermore, bacteria-like microorganisms were discovered within Peperomia cells, suggesting that this genus provides an interesting model not only for studying plastid biology but also for investigating plant-microbe interactions.}, language = {en} } @phdthesis{Alahverdjieva2007, author = {Alahverdjieva, Veneta}, title = {Experimental study of mixed protein/surfactant systems at the aqueous solution/air interface}, address = {Potsdam}, pages = {XIV, 146 S., X : graph. Darst.}, year = {2007}, language = {en} } @phdthesis{Appl2007, author = {Appl, Thomas}, title = {Neurochemical and functional characterisation of the Melanin-concentrating hormone system in the rat brain}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14604}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {The central melanin-concentrating hormone (MCH) system has been intensively studied for its involvement in the regulation of feeding behaviour and body weight regulation. The importance of the neuropeptide MCH in the control of energy balance has been underlined by MCH knock out and Melanin-concentrating hormone receptor subtype 1 (MCHR-1) knock-out animals. The anorectic and anti-obesity effects of selective MCHR-1 antagonists have confirmed the notion that pharmacological blockade of MCHR-1 is a potential therapeutic approach for obesity. First aim of this work is to study the neurochemical "equipment" of MCHR-1 immunoreactive neurons by double-labelling immunohistochemistry within the rat hypothalamus. Of special interest is the neuroanatomical identification of other hypothalamic neuropeptides that are co-distributed with MCHR-1. A second part of this study deals with the examination of neuronal activation patterns after pharmacological or physiological, feeding-related stimuli and was introduced to further understand central regulatory mechanisms of the MCH system. In the first part of work, I wanted to neurochemically characterize MCHR-1 immunoreactive neurons in the rat hypothalamus for colocalisation with neuropeptides of interest. Therefore I performed an immunohistochemical colocalisation study using a specific antibody against MCHR-1 in combination with antibodies against hypothalamic neuropeptides. I showed that MCHR-1 immunoreactivity (IR) was co-localised with orexin A in the lateral hypothalamus, and with adrenocorticotropic hormone and neuropeptide Y in the arcuate nucleus. Additionally, MCHR-1 IR was co-localised with the neuropeptides vasopressin and oxytocin in magnocellular neurons of the supraoptic and paraventricular hypothalamic nucleus and corticotrophin releasing hormone in the parvocellular division of the paraventricular hypothalamic nucleus. Moreover, for the first time MCHR-1 immunoreactivity was found in both the adenohypophyseal and neurohypophyseal part of the rat pituitary. These results provide the neurochemical basis for previously described potential physiological actions of MCH at its target receptor. In particular, the MCHR-1 may be involved not only in food intake regulation, but also in other physiological actions such as fluid regulation, reproduction and stress response, possibly through here examined neuropeptides. Central activation patterns induced by pharmacological or physiological stimulation can be mapped using c-Fos immunohistochemistry. In the first experimental design, central administration (icv) of MCH in the rat brain resulted in acute and significant increase of food and water intake, but this animal treatment did not induce a specific c-Fos induction pattern in hypothalamic nuclei. In contrast, sub-chronic application of MCHR-1 antagonist promoted a significant decrease in food- and water intake during an eight day treatment period. A qualitative analysis of c-Fos immunohistochemistry of sections derived from MCHR-1 antagonist treated animals showed a specific neuronal activation in the paraventricular nucleus, the supraoptic nucleus and the dorsomedial hypothalamus. These results could be substantiated by quantitative evaluation of an automated, software-supported analysis of the c-Fos signal. Additionally, I examined the activation pattern of rats in a restricted feeding schedule (RFS) to identify pathways involved in hunger and satiety. Animals were trained for 9 days to feed during a three hour period. On the last day, food restricted animals was also allowed to feed for the three hours, while food deprived (FD) animals did not receive food. Mapping of neuronal activation showed a clear difference between stareved (FD) and satiated (FR) rats. FD animals showed significant induction of c-Fos in forebrain regions, several hypothalamic nuclei, amygdaloid thalamus and FR animals in the supraoptic nucleus and the paraventricular nucleus of the hypothalamus, and the nucleus of the solitary tract. In the lateral hypothalamus of FD rats, c-Fos IR showed strong colocalisation for Orexin A, but no co-staining for MCH immunoreactivity. However, a large number of c-Fos IR neurons within activated regions of FD and FR animals was co-localised with MCHR-1 within selected regions. To conclude, the experimental set-up of scheduled feeding can be used to induce a specific hunger or satiety activation pattern within the rat brain. My results show a differential activation by hunger signals of MCH neurons and furthermore, demonstrates that MCHR-1 expressing neurons may be essential parts of downstream processing of physiological feeding/hunger stimuli. In the final part of my work, the relevance of here presented studies is discussed with respect to possible introduction of MCHR-1 antagonists as drug candidates for the treatment of obesity.}, language = {en} } @article{BassoAltafimAltafimetal.2007, author = {Basso, Heitor Cury and Altafim, Ruy Alberto Pisani and Altafim, Ruy Alberto Pisani and Mellinger, Axel and Fang, Peng and Wirges, Werner and Gerhard, Reimund}, title = {Three-layer ferroelectrets from perforated Teflon-PTFE films fused between two homogeneous Teflon-FEP films}, isbn = {978-1-4244-1482-6}, year = {2007}, language = {en} } @phdthesis{Beeg2007, author = {Beeg, Janina}, title = {Cooperative behavior of motor proteins}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15712}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {The cytoskeletal motor protein kinesin-1 (conventional kinesin) is the fast carrier for intracellular cargo transport along microtubules. So far most studies aimed at investigating the transport properties of individual motor molecules. However, the transport in cells usually involves the collective work of more than one motor. In the present work, we have studied the movement of beads as artificial loads/organelles pulled by several kinesin-1 motors in vitro. For a wide range of motor coverage of the beads and different bead (cargo) sizes the transport parameters walking distance or run length, velocity and force generation are measured. The results indicate that the transport parameters are influenced by the number of motors carrying the bead. While the transport velocity slightly decreases, an increase in the run length was measured and higher forces are determined, when more motors are involved. The effective number of motors pulling a bead is estimated by measuring the change in the hydrodynamic diameter of kinesin-coated beads using dynamic light scattering. The geometrical constraints imposed by the transport system have been taken into account. Thus, results for beads of different size and motor-surface coverage could be compared. In addition, run length-distributions obtained for the smallest bead size were matched to theoretically calculated distributions. The latter yielded an average number of pulling motors, which is in agreement with the effective motor numbers determined experimentally.}, language = {en} } @phdthesis{Begu2007, author = {Begu, Enkela}, title = {Elections in a spatial context : a case study of Albanian parliamentary elections, 1991-2005}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15923}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Exploring elections features from a geographical perspective is the focus of this study. Its primary objective is to develop a scientific approach based on geoinformation technology (GIT) that promotes deeper understanding how geographical settings affect the spatial and temporal variations of voting behaviour and election outcomes. For this purpose, the five parliamentary elections (1991-2005) following the political turnaround in 1990 in the South East European reform country Albania have been selected as a case study. Elections, like other social phenomena that do not develop uniformly over a territory, inherit a spatial dimension. Despite of fact that elections have been researched by various scientific disciplines ranging from political science to geography, studies that incorporate their spatial dimension are still limited in number and approaches. Consequently, the methodologies needed to generate an integrated knowledge on many facets that constitute election features are lacking. This study addresses characteristics and interactions of the essential elements involved in an election process. Thus, the baseline of the approach presented here is the exploration of relations between three entities: electorate (political and sociodemographic features), election process (electoral system and code) and place (environment where voters reside). To express this interaction the concept of electoral pattern is introduced. Electoral patterns are defined by the study as the final view of election results, chiefly in tabular and/or map form, generated by the complex interaction of social, economic, juridical, and spatial features of the electorate, which has occurred at a specific time and in a particular geographical location. GIT methods of geoanalysis and geovisualization are used to investigate the characteristics of electoral patterns in their spatial and temporal distribution. Aggregate-level data modelled in map form were used to analyse and visualize the spatial distribution of election patterns components and relations. The spatial dimension of the study is addressed in the following three main relations: One, the relation between place and electorate and its expression through the social, demographic and economic features of the electorate resulting in the profile of the electorate's context; second, the electorate-election interaction which forms the baseline to explore the perspective of local contextual effects in voting behaviour and election results; third, the relation between geographical location and election outcomes reflecting the implication of determining constituency boundaries on election results. To address the above relations, three types of variables: geo, independent and dependent, have been elaborated and two models have been created. The Data Model, developed in a GIS environment, facilitates structuring of election data in order to perform spatial analysis. The peculiarity of electoral patterns - a multidimensional array that contains information on three variables, stored in data layers of dissimilar spatial units of reference and scales of value measurement - prohibit spatial analysis based on the original source data. To perform a joint spatial analysis it is therefore mandatory to restructure the spatial units of reference while preserving their semantic content. In this operation, all relevant electoral as well as socio-demographic data referenced to different administrative spatial entities are re-referenced to uniform grid cells as virtual spatial units of reference. Depending on the scale of data acquisition and map presentation, a cell width of 0.5 km has been determined. The resulting fine grid forms the basis of subsequent data analyses and correlations. Conversion of the original vector data layers into target raster layers allows for unification of spatial units, at the same time retaining the existing level of detail of the data (variables, uniform distribution over space). This in turn facilitates the integration of the variables studied and the performance of GIS-based spatial analysis. In addition, conversion to raster format makes it possible to assign new values to the original data, which are based on a common scale eliminating existing differences in scale of measurement. Raster format operations of the type described are well-established data analysis techniques in GIT, yet they have rarely been employed to process and analyse electoral data. The Geovisualization Model, developed in a cartographic environment, complements the Data Model. As an analog graphic model it facilitates efficient communication and exploration of geographical information through cartographic visualization. Based on this model, 52 choropleth maps have been generated. They represent the outcome of the GIS-based electoral data analysis. The analog map form allows for in-depth visual analysis and interpretation of the distribution and correlation of the electoral data studied. For researchers, decision makers and a wider public the maps provide easy-to-access information on and promote easy-to-understand insight into the spatial dimension, regional variation and resulting structures of the electoral patterns defined.}, language = {en} } @article{Bell2007, author = {Bell, Elanor M.}, title = {Seasonal changes in the concentration and metabolic activity of bacteria and viruses at an Antarctic coastal site}, year = {2007}, abstract = {Bacteria play a key role in the world's oceans, supporting nutrient remineralisation and mediating carbon transfer. Little is known about annual changes in bacterial concentration, production and metabolism during the extreme seasonal changes in biological productivity in Antarctic waters. We measured rates of bacterial production, concentrations of viruses and bacteria and environmental parameters between February 2004 and January 2005 at an Antarctic coastal site. Concentrations of total bacteria and viruses were obtained using 4', 6-diamidino-2- phenylindole (DAPI) and SYBR Green I (Molecular Probes), respectively. Populations of bacteria in different metabolic states were estimated using vital stains. Concentrations of bacteria with intact or compromised plasma membranes were estimated using BacLight (Molecular Probes) and active cells estimated using 6-carboxyfluorescein diacetate (6CFDA). Our study showed 6CFDA and BacLight gave rapid and ecologically valuable insights into bacterial physiology, production and growth in natural Antarctic communities that were poorly represented by changes in total cell concentrations. Concentrations of total, active and intact bacteria declined rapidly at the end of summer probably owing to viral infection and microheterotrophic grazing. The decline continued over winter, likely owing to substrate limitation, and concentrations only increased after the phytoplankton bloom in spring and summer. Bacterial abundance was positively correlated with particulate organic carbon (POC) and nitrogen (PON), but not dissolved organic carbon (DOC), reflecting the refractory nature of the DOC pool. Only active and intact bacteria were significantly correlated with concentrations of chl a and rates of bacterial production. Furthermore, the obtained rates of [H-3]thymidine uptake suggest that bacterial growth rates can be sustained by the populations identified as intact or by active cells alone.}, language = {en} } @article{BellParkPearceetal.2007, author = {Bell, Elanor M. and Park, Tae-Gyu and Pearce, Imojen and Rublee, Parke A. and Bolch, Christopher J. S. and Hallegraeff, Gustaff M.}, title = {Detection of a novel ecotype of Pfiesteria piscicida (Dinophyceae) in an Antarctic saline lake by real-time PCR}, year = {2007}, language = {en} } @article{BergerMuellerHoehleetal.2007, author = {Berger, Frauke and M{\"u}ller, Anja and H{\"o}hle, Barbara and Weissenborn, J{\"u}rgen}, title = {German 4-year-olds comprehension of sentences containing the focus particle "auch" (also) : evidence from eye- tracking}, year = {2007}, language = {en} } @phdthesis{Beyer2007, author = {Beyer, Florian}, title = {Asymptotics and singularities in cosmological models with positive cosmological constant}, address = {Potsdam}, pages = {173 S. : graph. Darst.}, year = {2007}, language = {en} } @phdthesis{Bielecka2007, author = {Bielecka, Monika}, title = {Analysis of transcription factors under sulphur deficiency stress}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14812}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Sulphur, a macronutrient essential for plant growth, is among the most versatile elements in living organisms. Unfortunately, little is known about regulation of sulphate uptake and assimilation by plants. Identification of sulphate signalling processes will allow to control sulphate acquisition and assimilation and may prove useful in the future to improve sulphur-use efficiency in agriculture. Many of genes involved in sulphate metabolism are regulated on transcriptional level by products of other genes called transcription factors (TF). Several published experiments revealed TF genes that respond to sulphate deprivation, but none of these have been so far been characterized functionally. Thus, we aimed at identifying and characterising transcription factors that control sulphate metabolism in the model plant Arabidopsis thaliana. To achieve that goal we postulated that factors regulating Arabidopsis responses to inorganic sulphate deficiency change their transcriptional levels under sulphur-limited conditions. By comparing TF transcript profiles from plants grown on different sulphate regimes, we identified TF genes that may specifically induce or repress changes in expression of genes that allow plants to adapt to changes in sulphate availability. Candidate genes obtained from this screening were tested by reverse genetics approaches. Transgenic plants constitutively overproducing selected TF genes and mutant plants, lacking functional selected TF genes (knock out), were used. By comparing metabolite and transcript profiles from transgenic and wild type plants we aimed at confirming the role of selected AP2 TF candidate genes in plant adaptation to sulphur unavailability. After preliminary characterisation of WRKY24 and MYB93 TF genes, we postulate that these factors are involved in a complex multifactorial regulatory network, in which WRKY24 and MYB93 would act as superior factors regulating other transcription factors directly involved in the regulation of S-metabolism genes. Results obtained for plants overproducing TOE1 and TOE2 TF genes suggests that these factors may be involved in a mechanism, which is promoting synthesis of an essential amino acid, methionine, over synthesis of another amino acid, cysteine. Thus, TOE1 and TOE2 genes might be a part of transcriptional regulation of methionine synthesis. Approaches creating genetically manipulated plants may produce plant phenotypes of immediate biotechnological interest, such as plants with increased sulphate or sulphate-containing amino acid content, or better adapted to the sulphate unavailability.}, language = {en} } @phdthesis{Bischoff2007, author = {Bischoff, Volker}, title = {Molecular analysis of cellulose synthesis in Arabidopsis thaliana}, address = {Potsdam}, pages = {XIII, 113 S. : Ill, graph. Darst.}, year = {2007}, language = {en} } @phdthesis{Blaszczak2007, author = {Blaszczak, Joanna}, title = {Phase syntax : the polish genitive of negation}, pages = {x, 365 S.}, year = {2007}, language = {en} } @article{BleekerSchmitzRistow2007, author = {Bleeker, Walter and Schmitz, Ulf and Ristow, Michael}, title = {Interspecific hybridisation between alien and native plant species in Germany and its consequences for native biodiversity}, issn = {0006-3207}, doi = {10.1016/j.biocon.2007.02.004}, year = {2007}, abstract = {We explored the extent of interspecific hybridisation between alien and native plant species in Germany with a special focus on the potential threat for native biodiversity. In total we listed 134 hybrids which are interpreted as products of hybridisation between 81 alien and 109 native plant species (including 13 archeophytes) that occur in Germany Seventy-five of these hybrids have been recorded in Germany, while the remaining 59 hybrids have not been detected in Germany yet, although both parental species currently occur in Germany. Interspecific hybridisation between abundant alien and rare native species can threaten populations of the native species through outbreeding depression and/ or through high rates of gene flow swamping native populations. We identified 37 threatened native plant species which hybridise with aliens. Seventeen of these threatened plant species may suffer from outbreeding depression when hybridising with a more abundant alien invader (minority disadvantage). Using hybrid abundance as an indicator of hybrid fitness we argue that introgression of alien genes may affect the gene pool of eight threatened native plant species. Consequently, hybridisation with aliens has to be considered as an additional risk potentially leading to a loss of biodiversity and should be included in the repertoire of causes for rare species extinction in German Red Lists of threatened plant species.}, language = {en} } @misc{BlenauTroppmannWalz2007, author = {Blenau, Wolfgang and Troppmann, Britta and Walz, Bernd}, title = {Pharmacology of serotonin-induced salivary secretion in Periplaneta americana}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44319}, year = {2007}, abstract = {The acinar salivary gland of the cockroach, Periplaneta americana, is innervated by dopaminergic and serotonergic nerve fibers. Stimulation of the glands by serotonin (5-hydroxytryptamine, 5-HT) results in the production of a protein-rich saliva, whereas stimulation by dopamine results in saliva that is protein-free. Thus, dopamine acts selectively on ion-transporting peripheral cells within the acini, and 5-HT acts on protein-producing central cells. We have investigated the pharmacology of the 5-HT-induced secretory activity of isolated salivary glands of P. americana by testing several 5-HT receptor agonists and antagonists. The effects of 5-HT can be mimicked by the non-selective 5-HT receptor agonist 5-methoxytryptamine. All tested agonists that display at least some receptor subtype specificity in mammals, i.e., 5-carboxamidotryptamine, (+/-)-8-OH-DPAT, (+/-)-DOI, and AS 19, were ineffective in stimulating salivary secretion. 5-HT-induced secretion can be blocked by the vertebrate 5-HT receptor antagonists methiothepin, cyproheptadine, and mianserin. Our pharmacological data indicate that the pharmacology of arthropod 5-HT receptors is remarkably different from that of their vertebrate counterparts. (C) 2007 Elsevier Ltd. All rights reserved.}, language = {en} } @article{BlomeyerTreutleinEsseretal.2007, author = {Blomeyer, Dorothea and Treutlein, Jens and Esser, G{\"u}nter and Schmidt, Martin H. and Schumann, Gunter and Laucht, Manfred}, title = {Interaction between CRHR1 gene and stressful life events predicts adolescent heavy alcohol use}, issn = {0006-3223}, year = {2007}, abstract = {Background: Recent animal research suggests that alterations in the corticotropin releasing hormone receptor 1 (CRHR1) may lead to heavy alcohol use following repeated stress. The aim of this study was to examine interactions between two haplotype-tagging single nucleotide polymorphisms (SNPs) covering the CRHR1 gene and adverse life events on heavy drinking in adolescents. Methods: Data were available from the Mannheim Study of Children at Risk, an ongoing cohort study of the long-term outcome of early risk factors followed since birth. At age 15 years, 280 participants (135 males, 145 females) completed a self-report questionnaire measuring alcohol use and were genotyped for two SNPs (rs242938, rs1876831) of CRHR1. Assessment of negative life events over the past three years was obtained by a standardized interview with the parents. Results: Adolescents homozygous for the C allele of rs1876831 drank higher maximum amounts of alcohol per occasion and had greater lifetime rates of heavy drinking in relation to negative life events than individuals carrying the T allele. No gene X environment interactions were found for regular drinking and between rs242938 and stressful life events. Conclusions: These findings provide first evidence in humans that the CRHR1 gene interacts with exposure to stressful life events to predict heavy alcohol use in adolescents.}, language = {en} } @article{BohnKliegl2007, author = {Bohn, Christiane and Kliegl, Reinhold}, title = {Post-interpretive processes influence interpretive processing during reading: evidence from eye movements}, isbn = {978-18-4169-96-9}, year = {2007}, language = {en} } @article{BoechatWeithoffKruegeretal.2007, author = {Bo{\"e}chat, Iola G. and Weithoff, Guntram and Kr{\"u}ger, Angela and G{\"u}cker, Bj{\"o}rn and Adrian, Rita}, title = {A biochemical explanation for the success of the mixotrophy in the flagellate Ochromonas sp.}, issn = {0024-3590}, doi = {10.4319/lo.2007.52.4.1624}, year = {2007}, abstract = {We report the influence of different nutritional modes-autotrophy, mixotrophy, and heterotrophy-on the fatty acid and sterol composition of the freshwater flagellate Ochromonas sp. and discuss the ecological significance of our results with respect to the resource competition theory (rct). Polyunsaturated fatty acids (PUFAs) are the most efficient biochemical variable distinguishing between nutritional modes of Ochromonas sp. Decreasing concentrations of PUFAs were observed in the order autotrophs, mixotrophs, heterotrophs. In mixotrophs and heterotrophs, concentrations of saturated fatty acids were higher than those of monounsaturated fatty acids and PUFAs as a result of bacterivory. Stigmasterol was the main sterol in Ochromonas sp., regardless of nutritional mode. Mixotrophs showed higher growth rates than heterotrophs, which could not be explained by rct. Heterotrophs, in turn, exhibited higher growth rates than autotrophs, which were cultured under the same light conditions as mixotrophs. Mixotrophs can synthesize PUFAs, which are important for many physiological functions such as membrane permeability and growth. Thus, mixotrophy facilitated efficient growth as well as the ability to synthesize complex and essential biomolecules. These strong synergetic effects are due to the combination of biochemical benefits of heterotrophic and autotrophic metabolic pathways and cannot be predicted by rct.}, language = {en} } @article{BrainFaberMarateaetal.2007, author = {Brain, Martin and Faber, Wolfgang and Maratea, Marco and Polleres, Axel and Schaub, Torsten H. and Schindlauer, Roman}, title = {What should an ASP solver output? : a multiple position paper}, year = {2007}, language = {en} } @article{BrainGebserPuehreretal.2007, author = {Brain, Martin and Gebser, Martin and P{\"u}hrer, J{\"o}rg and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {"That is illogical, Captain!" : the debugging support tool spock for answer-set programs ; system description}, year = {2007}, language = {en} } @article{BrainGebserPuehreretal.2007, author = {Brain, Martin and Gebser, Martin and P{\"u}hrer, J{\"o}rg and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {Debugging ASP programs by means of ASP}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{BrajpuriyaTripathiSharmaetal.2007, author = {Brajpuriya, Ranjeet and Tripathi, Sumit and Sharma, Abhishek and Chaudhari, S.M. and Phase, D.M. and Gupta, Ajay and Shripathi, Thoudinja and Leitenberger, Wolfram and Pietsch, Ullrich and Laxmi, N.}, title = {Temperature dependent energy-dispersive X-ray diffraction and magnetic study of Fe/Al interface}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2007.04.069}, year = {2007}, abstract = {In situ temperature dependent energy-dispersive structural and magnetic study of electron beam evaporated Fe/Al multilayer sample (MLS) has been investigated. The structural studies show the formation of an intermixed FeAl transition layer of a few nanometers thick at the interface during deposition, which on annealing at 300 degrees C transforms to B2FeAl intermetallic phase. Magnetization decreases with increase in temperature and drops to minimum above 300 degrees C due to increase in anti-ferromagnetic interlayer coupling and formation of nonmagnetic FeAl phase at the interface. The Curie temperature (T-c) is found to be 288 degrees C and is much less than that of bulk bcc Fe.}, language = {en} } @article{Braun2007, author = {Braun, Jutta}, title = {"Very nice, the enemies are gone!" : coming to terms with GDR sports since 1989/90}, issn = {0172-6404}, year = {2007}, abstract = {Als die SED-Diktatur zusammenbrach, {\"u}bte der Glanz der ostdeutschen Medaillen nach wie vor eine große Anziehungskraft aus, vor allem auf westdeutsche Sportpolitiker. Der Sport war ein Spezialfall der deutschen Vereinigung, da hier der Westen vom Osten zu lernen hoffte. Bald jedoch wurden die dunklen Seiten des DDR-Sports offensichtlich: die Verstrickung mit dem Ministerium f{\"u}r Staatsicherheit ebenso wie das staatlich forcierte Zwangsdoping. Bis heute gehen die Meinungen {\"u}ber den DDR-Sport weit auseinander: w{\"a}hrend die Einen ihn als repressiv und unmenschlich verurteilen, wird er von den Anderen gleichzeitig als Organisationsvorbild f{\"u}r die Zukunft gehandelt.}, language = {en} } @book{BaerGinouxPfaeffle2007, author = {B{\"a}r, Christian and Ginoux, Nicolas and Pf{\"a}ffle, Frank}, title = {Wave equations on lorentzian manifolds and quantization}, publisher = {European Math. Society}, address = {Z{\"u}rich}, isbn = {978-3-03719-037-1}, pages = {194 S.}, year = {2007}, language = {en} } @phdthesis{Caldana2007, author = {Caldana, Camila}, title = {Genome wide identification and functional characterization of transcription factors involved in the initial phase of salt stress in rice}, address = {Potsdam}, pages = {vi, 154 S.: Ill., graph. Darst.}, year = {2007}, language = {en} } @phdthesis{Caldana2007, author = {Caldana, Camila}, title = {Genome wide identification and functional characterization of transcription factors involvend in the initial phase of salt stress in rice}, address = {Potsdam}, pages = {154 S., i-vi, : graph. Darst.}, year = {2007}, language = {en} } @phdthesis{CastroMarin2007, author = {Castro Marin, Inmaculada}, title = {Nitrate: metabolism and development}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18827}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {The major aim of this thesis was to study the effect of nitrate on primary metabolism and in development of the model plant Arabidopsis thaliana. The present work has two separate topics. First, to investigate the GDH family, a small gene family at the interface between nitrogen and carbon metabolisms. Second, to investigate the mechanisms whereby nitrogen is regulating the transition to flowering time in Arabidopsis thaliana. To gain more insights into the regulation of primary metabolism by the functional characterization of the glutamate dehydrogenase (GDH) family, an enzyme putatively involved in the metabolism of amino acids and thus suggested to play different and essential roles in carbon and nitrogen metabolism in plants, knock out mutants and transgenic plants carrying RNA interference construct were generated and characterized. The effect of silencing GDH on carbon and nitrogen metabolisms was investigated, especially the level of carbohydrates and the amino acid pool were further analysed. It has been shown that GDH expression is regulated by light and/or sugar status therefore, phenotypic and metabolic analysis were developed in plants grown at different points of the diurnal rhythm and in response to an extended night period. In addition, we are interested in the effect of nutrient availability in the transition from vegetative growth to flowering and especially in nitrate as a metabolite that triggers widespread and coordinated changes in metabolism and development. Nutrient availability has a dramatic effect on flowering time, with a marked delay of flowering when nitrate is supplied (Stitt, 1999). The use of different mutants and transgenic plants impaired in flowering signalling pathways was crucial to evaluate the impact of different nitrate concentrations on flowering time and to better understand the interaction of nitrate-dependent signals with other main flowering signalling pathways. Plants were grown on glutamine as a constitutive source of nitrogen, and the nitrate supply varied. Low nitrate led to earlier flowering. The response to nitrate is accentuated in short days and in the CONSTANS deficient co2 mutant, whereas long days or overexpression of CONSTANS overrides the nitrate response. These results indicate that nitrates acts downstream of the known flowering signalling pathways for photoperiod, autonomy, vernalization and gibberellic acid. Global analyses of gene expression of two independent flowering systems, a light impaired mutant (co2tt4) and a constitutive over-expresser of the potent repressor of flowering (35S::FLC), were to be investigated under two different concentrations of nitrate in order to identify candidate genes that may be involved in the regulation of flowering time by nitrate.}, language = {en} } @book{ChampagnatRoelly2007, author = {Champagnat, Nicolas and Roelly, Sylvie}, title = {Multitype Dawson-Watanabe superprocesses conditioned by remote survival}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Mathematische Statistik un}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Mathematische Statistik un}, publisher = {Univ.}, address = {Potsdam}, issn = {1613-3307}, pages = {39 S.}, year = {2007}, language = {en} } @article{ChenLi2007, author = {Chen, Hua and Li, Ke}, title = {The existence and regularity of multiple solutions for a class of infinitely degenerate elliptic equations}, 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 = {23 S.}, year = {2007}, language = {en} } @book{ChenLiXu2007, author = {Chen, Huan and Li, Wei-Xi and Xu, Chao-Jiang}, title = {Gevrey hypoellipticity for linear and non-linear fokker-planck equations}, 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 = {17 S.}, year = {2007}, language = {en} } @article{Clegg2007, author = {Clegg, Mark R.}, title = {Behavioral response as a predictor of seasonal depth distribution and vertical niche separation in freshwater phytoplanktonic flagellates}, year = {2007}, language = {en} } @phdthesis{ColpanZenginoglu2007, author = {Colpan Zenginoglu, Anil}, title = {A conformal approach to numerical calculations of asymptotically flat spacetimes}, address = {Potsdam}, pages = {101 S. : graph. Darst.}, year = {2007}, language = {en} } @article{DambacherKliegl2007, author = {Dambacher, Michael and Kliegl, Reinhold}, title = {Synchronizing timelines : relations between fixation durations and N400 amplitudes during sentence reading}, issn = {0006-8993}, doi = {10.1016/j.brainres.2007.04.027}, year = {2007}, abstract = {We examined relations between eye movements (single-fixation durations) and RSVP-based event-related potentials (ERPs; N400s) recorded during reading the same sentences in two independent experiments. Longer fixation durations correlated with larger N400 amplitudes. Word frequency and predictability of the fixated word as well as the predictability of the upcoming word accounted for this covariance in a path-analytic model. Moreover, larger N400 amplitudes entailed longer fixation durations on the next word, a relation accounted for by word frequency. This pattern offers a neurophysiological correlate for the lag-word frequency effect on fixation durations: word processing is reliably expressed not only in fixation durations on currently fixated words, but also in those on subsequently fixated words.}, language = {en} } @article{DelgrandeLangSchaub2007, author = {Delgrande, James Patrick and Lang, J{\´e}r{\^o}me and Schaub, Torsten H.}, title = {Belief change based on global minimisation}, year = {2007}, language = {en} } @article{DelgrandeLiuSchaubetal.2007, author = {Delgrande, James Patrick and Liu, Daphne H. and Schaub, Torsten H. and Thiele, Sven}, title = {COBA 2.0 : a consistency-based belief change system}, year = {2007}, language = {en} } @article{DelgrandeSchaub2007, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {A consistency-based framework for merging knowledge bases}, issn = {1570-8683}, year = {2007}, language = {en} } @article{DelgrandeSchaubTompits2007, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A preference-based framework for updating logic programs}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{DelgrandeSchaubTompits2007, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A general framework for expressing preferences in causal reasoning and planning}, issn = {0955-792X}, doi = {10.1093/logcom/exm046}, year = {2007}, abstract = {We consider the problem of representing arbitrary preferences in causal reasoning and planning systems. In planning, a preference may be seen as a goal or constraint that is desirable, but not necessary, to satisfy. To begin, we define a very general query language for histories, or interleaved sequences of world states and actions. Based on this, we specify a second language in which preferences are defined. A single preference defines a binary relation on histories, indicating that one history is preferred to the other. From this, one can define global preference orderings on the set of histories, the maximal elements of which are the preferred histories. The approach is very general and flexible; thus it constitutes a base language in terms of which higher-level preferences may be defined. To this end, we investigate two fundamental types of preferences that we call choice and temporal preferences. We consider concrete strategies for these types of preferences and encode them in terms of our framework. We suggest how to express aggregates in the approach, allowing, e.g. the expression of a preference for histories with lowest total action costs. Last, our approach can be used to express other approaches and so serves as a common framework in which such approaches can be expressed and compared. We illustrate this by indicating how an approach due to Son and Pontelli can be encoded in our approach, as well as the language PDDL3.}, language = {en} } @phdthesis{Demircioglu2007, author = {Demircioglu, Aydin}, title = {Reconstruction of deligne classes and cocycles}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13755}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {In der vorliegenden Arbeit verallgemeinern wir im Wesentlichen zwei Theoreme von Mackaay-Picken und Picken (2002, 2004). Im ihrem Artikel zeigen Mackaay und Picken,dass es eine bijektive Korrespodenz zwischen Deligne 2-Klassen \$\xi \in \check{H}^2(M, \mathcal{D}^2)\$ und Holonomie Abbildungen von der zweiten d{\"u}nnen Homotopiegruppe \$\pi_2^2(M)\$ in die abelsche Gruppe \$U(1)\$ gibt. Im zweiten Artikel wird eine Verallgemeinerung dieses Theorems bewiesen: Picken zeigt, dass es eine Bijektion gibt zwischen Deligne 2-Kozykeln und gewissen 2-dimensionalen topologischen Quantenfeldtheorien. In dieser Arbeit zeigen wir, dass diese beiden Theoreme in allen Dimensionen gelten.Wir betrachten zun{\"a}chst den Holonomie Fall und k{\"o}nnen mittels simplizialen Methoden nachweisen, dass die Gruppe der glatten Deligne \$d\$-Klassen isomorph ist zu der Gruppe der glatten Holonomie Abbildungen von der \$d\$-ten d{\"u}nnen Homotopiegruppe \$\pi_d^d(M)\$ nach \$U(1)\$, sofern \$M\$ eine \$(d-1)\$-zusammenh{\"a}ngende Mannigfaltigkeit ist. Wir vergleichen dieses Resultat mit einem Satz von Gajer (1999). Gajer zeigte, dass jede Deligne \$d\$-Klasse durch eine andere Klasse von Holonomie-Abbildungen rekonstruiert werden kann, die aber nicht nur Holonomien entlang von Sph{\"a}ren, sondern auch entlang von allgemeinen \$d\$-Mannigfaltigkeiten in \$M\$ enth{\"a}lt. Dieser Zugang ben{\"o}tigt dann aber nicht, dass \$M\$ hoch-zusammenh{\"a}ngend ist. Wir zeigen, dass im Falle von flachen Deligne \$d\$-Klassen unser Rekonstruktionstheorem sich von Gajers unterscheidet, sofern \$M\$ nicht als \$(d-1)\$, sondern nur als \$(d-2)\$-zusammenh{\"a}ngend angenommen wird. Stiefel Mannigfaltigkeiten besitzen genau diese Eigenschaft, und wendet man unser Theorem auf diese an und vergleicht das Resultat mit dem von Gajer, so zeigt sich, dass es zuviele Deligne Klassen rekonstruiert. Dies bedeutet, dass unser Rekonstruktionsthreorem ohne die Zusatzbedingungen an die Mannigfaltigkeit M nicht auskommt, d.h. unsere Rekonstruktion ben{\"o}tigt zwar weniger Informationen {\"u}ber die Holonomie entlang von d-dimensionalen Mannigfaltigkeiten, aber daf{\"u}r muss M auch \$(d-1)\$-zusammenh{\"a}ngend angenommen werden. Wir zeigen dann, dass auch das zweite Theorem verallgemeinert werden kann: Indem wir das Konzept einer Picken topologischen Quantenfeldtheorie in beliebigen Dimensionen einf{\"u}hren, k{\"o}nnen wir nachweisen, dass jeder Deligne \$d\$-Kozykel eine solche \$d\$-dimensionale Feldtheorie mit zwei besonderen Eigenschaften, der d{\"u}nnen Invarianz und der Glattheit, induziert. Wir beweisen, dass jede \$d\$-dimensionale topologische Quantenfeldtheorie nach Picken mit diesen zwei Eigenschaften auch eine Deligne \$d\$-Klasse definiert und pr{\"u}fen nach, dass diese Konstruktion sowohl surjektiv als auch injektiv ist. Demzufolge sind beide Gruppen isomorph.}, language = {en} } @article{DolchBatsaikhanThieleetal.2007, author = {Dolch, D. and Batsaikhan, Nyamsuren and Thiele, K. and Burger, F. and Scheffler, Ingo and Kiefer, A. and Mayer, Frank and Samjaa, R. and Stubbe, Annegret and Stubbe, Michael and Krall, L. and Steinhauser, D.}, title = {Contributions to the chiroptera of Mongolia with first evidences on species communities and ecological niches}, issn = {0440-1298}, year = {2007}, language = {en} } @article{DonnerFeudelSeehaferetal.2007, author = {Donner, Reik Volker and Feudel, Fred and Seehafer, Norbert and Sanjuan, Miguel Angel Fernandez}, title = {Hierarchical modeling of a forced Roberts Dynamo}, issn = {0218-1274}, doi = {10.1142/S021812740701941X}, year = {2007}, abstract = {We investigate the dynamo effect in a flow configuration introduced by G. O. Roberts in 1972. Based on a clear energetic hierarchy of Fourier components on the steady-state dynamo branch, an approximate model of interacting modes is constructed covering all essential features of the complete system but allowing simulations with a minimum amount of computation time. We use this model to study the excitation mechanism of the dynamo, the transition from stationary to time-dependent dynamo solutions and the characteristic properties of the latter ones.}, language = {en} } @misc{DoscheMicklerLoehmannsroebenetal.2007, author = {Dosche, Carsten and Mickler, Wulfhard and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Agenet, Nicolas and Vollhardt, K. Peter C.}, title = {Photoinduced electron transfer in [N]phenylenes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12463}, year = {2007}, abstract = {First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants kq and the free energy change of the electron transfer (ΔG0CS ) could be described by the Rehm-Weller equation. From the experimental results, a reorganization energy λ of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic ΔG0CS can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state.}, language = {en} } @article{DoscheMicklerLoehmannsroebenetal.2007, author = {Dosche, Carsten and Mickler, Wulfhard and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Agenet, Nicolas and Vollhardt, K. Peter C.}, title = {Photoinduced electron transfer in [N]phenylenes}, issn = {1010-6030}, doi = {10.1016/j.jphotochem.2006.12.038}, year = {2007}, abstract = {First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants k(q) and the free energy change of the electron transfer (Delta G(CS)(0)) could be described by the Rehm- Weller equation. From the experimental results, a reorganization energy lambda of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic charge separation process can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state.}, language = {en} } @phdthesis{Doyle2007, author = {Doyle, Timothy F.}, title = {The role of context in meaning and understanding}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-20691}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {In this work the concept of 'context' is considered in five main points. First, context is seen as always necessary for an adequate explication of the concepts of meaning and understanding. Context always plays a role and is not merely brought into consideration when handling a special class of statements or terms, or when there is doubt and clarification is necessary. Second, context cannot be completely reduced to some system of representation. The reason for this is the presence of humans, which is always an important component of a context. Humans experience situations in ways that are not always reducible to symbolic representation. Third, contexts are in principle open. In normal cases they cannot be determined or described in advance. A context is not to be equated with a set of information. Fourth, we understand the parameters of a context pragmatically, which is why we are not led into doubt or even to meaning skepticism by the open nature of a context. This pragmatic knowledge belongs to the category of an ability. Fifth, contexts are, in principle, accessible. This denies the idea that some contexts are incommensurable. There are a number of pragmatic ways of accessing unfamiliar contexts. Some of these are here examined in light of the so-called 'culture wars' in the U.S.A.}, language = {en} } @phdthesis{Dronov2007, author = {Dronov, Roman}, title = {Multi-component protein films by layer-by-layer : assembly and electron transfer}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17281}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Electron transfer phenomena in proteins represent one of the most common types of biochemical reactions. They play a central role in energy conversion pathways in living cells, and are crucial components in respiration and photosynthesis. These complex biochemical reaction cascades consist of a series of proteins and protein complexes that couple a charge transfer to different forms of chemical energy. The efficiency and sophisticated optimisation of signal transfer in these natural redox chains has inspired engineering of artificial architectures mimicking essential properties of their natural analogues. Implementation of direct electron transfer (DET) in protein assemblies was a breakthrough in bioelectronics, providing a simple and efficient way for coupling biological recognition events to a signal transducer. DET avoids the use of redox mediators, reducing potential interferences and side reactions, as well as being more compatible with in vivo conditions. However, only a few haem proteins, including the redox protein cytochrome c (cyt.c), and blue copper enzymes show efficient DET on different kinds of electrodes. Previous investigations with cyt.c have mainly focused on heterogeneous electron transfer of monolayers of this protein on gold. An important advance was the fabrication of cyt.c multilayers by electrostatic layer-by-layer self-assembly. The ease of fabrication, the stability, and the controllable permeability of polyelectrolyte multilayers have made them particularly attractive for electroanalytical applications. With cyt.c and sulfonated polyaniline it was for the first time possible that fully electro-active multilayers of the redox protein could be prepared. This approach was extended to design an analytical signal chain based on multilayers of cyt.c and xanthine oxidase (XOD). The system does not need an external mediator but relies on an in situ generation of a mediating radical and thus allows a signal transfer from hypoxanthine via the substrate converting enzyme and cyt.c to the electrode. Another kind of a signal chain is based on assembling proteins in complexes on electrodes in such a way that a direct protein-protein electron transfer becomes feasible. This design does not need a redox mediator in analogy to natural protein communication. For this purpose, cyt.c and the enzyme bilirubin oxidase (BOD, EC 1.3.3.5) are co-immobilized in a self-assembled polyelectrolyte multilayer on gold electrodes. Although these two proteins are not natural reaction partners, the protein architecture facilitates an electron transfer from the electrode via multiple protein layers to molecular oxygen resulting in a significant catalytic reduction current. Finally, we describe a novel strategy for multi-protein layer-by-layer self-assembly combining cyt.c with an enzyme sulfite oxidase (SOx) without use of any additional polymer. Electrostatic interactions between these two proteins with rather separated pI values during the assembly process from a low ionic strength buffer were found sufficient for the layer-by-layer deposition of the both biomolecules. It is anticipated that the concepts described in this work will stimulate further progress in multilayer design of even more complex biomimetic signal cascades taking advantage of direct communication between proteins.}, language = {en} } @phdthesis{Drost2007, author = {Drost, Kerstin}, title = {Sources and geotectonic setting of late neoproterozoic : early palaeozoic volcano-sedimentary successions of the Tepl{\´a}-Barrandian unit (Bohemian Massif) : Evidence from petrographical, geochemical, and isotope analyses}, address = {Potsdam}, pages = {VII, 132, XLIV S. : graph. Darst.}, year = {2007}, language = {en} } @article{Eckstein2007, author = {Eckstein, Lars}, title = {Three ways of looking at illegal immigration : clandestine existence in novels by Salman Rushdie, Christopher Hope and Caryl Phillips}, isbn = {978-3-8260-3769-6}, year = {2007}, language = {en} } @book{Eckstein2007, author = {Eckstein, Lars}, title = {English literatures across the globe : a companion}, series = {UTB : Literaturwissenschaft}, volume = {8345}, journal = {UTB : Literaturwissenschaft}, publisher = {Fink}, address = {Paderborn}, isbn = {978-3-4252-9}, pages = {360 S.}, year = {2007}, language = {en} } @article{Eckstein2007, author = {Eckstein, Lars}, title = {Introduction}, isbn = {978-3-8252-8345-2}, year = {2007}, language = {en} } @unpublished{Eckstein2007, author = {Eckstein, Lars}, title = {Three ways of looking at illegal immigration}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85567}, pages = {141 -- 157}, year = {2007}, language = {en} } @article{EcksteinLeypoldt2007, author = {Eckstein, Lars and Leypoldt, G{\"u}nter}, title = {T.S. Eliot and the transcultural sublime}, isbn = {978-3-88476-976-8}, year = {2007}, language = {en} } @phdthesis{Eisinger2007, author = {Eisinger, Dirk}, title = {A new management model for developing small scale contingency plans of rabies}, address = {Potsdam}, pages = {115 S. : graph. Darst.}, year = {2007}, language = {en} } @article{EndrissHinterwimmer2007, author = {Endriss, Cornelia and Hinterwimmer, Stefan}, title = {Direct and indirect aboutness topics}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19640}, year = {2007}, abstract = {We propose a definition of aboutness topicality that not only encompasses individual denoting DPs, but also indefinites. We concentrate on the interpretative effects of marking indefinites as topics: they either receive widest scope in their clause, or they are interpreted in the restrictor of an overt or covert Q-adverb. We show that in the first case they are direct aboutness topics insofar as they are the subject of a predication expressed by the comment, while in the second case they are indirect aboutness topics: they define the subject of a higher-order predication - namely the set of situations that the respective Q-adverb quantifies over.}, language = {en} } @article{EndrissHinterwimmer2007, author = {Endriss, Cornelia and Hinterwimmer, Stefan}, title = {Direct and indirect abountness topics}, isbn = {978-3-939469-88-9}, year = {2007}, language = {en} } @article{EngbertNuthmannKliegl2007, author = {Engbert, Ralf and Nuthmann, Antje and Kliegl, Reinhold}, title = {An lterative algorithm for the estimation of the distribution of mislocated fixations during reading}, isbn = {978-0-08-044980-7}, year = {2007}, language = {en} } @phdthesis{EntrialgoCastano2007, author = {Entrialgo Castano, Maria}, title = {Hydrolytic degradation of aliphatic polyester: molecular modeling and quantum mechanical investigations}, address = {Potsdam}, pages = {141 S. : graph. Darst.}, year = {2007}, language = {en} } @article{Ette2007, author = {Ette, Ottmar}, title = {Islands, borders, and Vectors : the Fractal World of the Caribbean}, isbn = {978-90-420-2184-6}, year = {2007}, language = {en} } @article{Ette2007, author = {Ette, Ottmar}, title = {Towards World Science? Humboldtian Science, World Concepts, and Transarea Studies}, isbn = {978-84-8489-303-5}, year = {2007}, language = {en} } @article{FangWegenerWirgesetal.2007, author = {Fang, Peng and Wegener, Michael and Wirges, Werner and Gerhard, Reimund and Zirkel, Larissa}, title = {Cellular polyethylene-naphthalate ferroelectrets : foaming in supercritical carbon dioxide, structural and electrical preparation, and resulting piezoelectricity}, issn = {0003-6951}, doi = {10.1063/1.2738365}, year = {2007}, abstract = {Polymer foams with electrically charged cellular voids, the so-called ferroelectrets, are soft piezoelectric transducer materials. Several polymers such as polyethylene terephthalate or cyclo-olefin copolymers are under investigation with respect to their suitability as ferroelectrets. Here, the authors report an additional ferroelectret polymer, cellular polyethylene-naphthalate (PEN), which was prepared from commercial uniform polymer films by means of foaming in supercritical carbon dioxide, inflation, biaxial stretching, electrical charging, and metallization. Piezoelectric d(33) coefficients of up to 140 pC/N demonstrate the suitability of such cellular PEN films for transducer applications. Their piezoelectricity is partially stable at elevated temperatures as high as 100 degrees C.}, language = {en} } @article{Fanselow2007, author = {Fanselow, Gisbert}, title = {The restricted access of Information Structure to syntax : a minority report}, isbn = {978-3-939469-88-9}, year = {2007}, language = {en} } @article{Fanselow2007, author = {Fanselow, Gisbert}, title = {The restricted access of information structure to syntax}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19713}, year = {2007}, abstract = {This paper sketches the view that syntax does not directly interact with information structure. Therefore, syntactic data are of little help when one wants to narrow down the interpretation of terms such as "focus", "topic", etc.}, language = {en} } @book{FladSchneiderSchulze2007, author = {Flad, H.-J. and Schneider, R. and Schulze, Bert-Wolfgang}, title = {Asymptotic Regularity of Solutions of Hartree-Fock Equations with Coulomb Potential}, 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 = {26 S.}, year = {2007}, language = {en} } @phdthesis{Frank2007, author = {Frank, Jonas}, title = {Decentralization in Ecuador : actors, institutions, and incentives}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {978-3-8329-2708-0}, pages = {327 S. : graph. Darst.}, year = {2007}, language = {en} } @phdthesis{Frankovitch2007, author = {Frankovitch, Christine Marie}, title = {Optical methods for monitoring biological parameters of phototropic microorganisms during cultivation}, address = {Potsdam}, pages = {iii, 95 S. : graph. Darst.}, year = {2007}, language = {en} } @book{FranzkeBoogersRuanoetal.2007, author = {Franzke, Jochen and Boogers, Marcel and Ruano, Jose M. and Schaap, Linze}, title = {Tensions between local governance and local democracy}, series = {Local Governance and Democracy}, volume = {1}, journal = {Local Governance and Democracy}, publisher = {Reed Business}, address = {The Hague}, isbn = {978-90-352-4176-3}, pages = {303 S.}, year = {2007}, language = {en} } @article{FranzkeBoogersRuanoetal.2007, author = {Franzke, Jochen and Boogers, Marcel and Ruano, Jose M. and Schaap, Linze}, title = {Introduction}, isbn = {978-90-352-4176-3}, year = {2007}, language = {en} } @article{FranzkeBoogersRuanoetal.2007, author = {Franzke, Jochen and Boogers, Marcel and Ruano, Jose M. and Schaap, Linze}, title = {Conclusions : Governance and Democracy at the Local Level - Structures, Processes and Tensions}, isbn = {978-90-352-4176-3}, year = {2007}, language = {en} } @article{FritzLoksteinHackenbergetal.2007, author = {Fritz, Markus and Lokstein, Heiko and Hackenberg, Dieter and Welti, Ruth and Roth, Mary and Z{\"a}hringer, Ulrich and Fulda, Martin and Hellmeyer, Wiebke and Ott, Claudia and Wolter, Frank P. and Heinz, Ernst}, title = {Channeling of eukaryotic diacylglycerol into the biosynthesis of plastidial phosphatidylglycerol}, issn = {0021-9258}, doi = {10.1074/jbc.M606295200}, year = {2007}, abstract = {Plastidial glycolipids contain diacylglycerol (DAG) moieties, which are either synthesized in the plastids (prokaryotic lipids) or originate in the extraplastidial compartment (eukaryotic lipids) necessitating their transfer into plastids. In contrast, the only phospholipid in plastids, phosphatidylglycerol (PG), contains exclusively prokaryotic DAG backbones. PG contributes in several ways to the functions of chloroplasts, but it is not known to what extent its prokaryotic nature is required to fulfill these tasks. As a first step toward answering this question, we produced transgenic tobacco plants that contain eukaryotic PG in thylakoids. This was achieved by targeting a bacterial DAG kinase into chloroplasts in which the heterologous enzyme was also incorporated into the envelope fraction. From lipid analysis we conclude that the DAG kinase phosphorylated eukaryotic DAG forming phosphatidic acid, which was converted into PG. This resulted in PG with 2-3 times more eukaryotic than prokaryotic DAG backbones. In the newly formed PG the unique Delta 3-trans-double bond, normally confined to 3-transhexadecenoic acid, was also found in sn-2- bound cis-unsaturated C18 fatty acids. In addition, a lipidomics technique allowed the characterization of phosphatidic acid, which is assumed to be derived from eukaryotic DAG precursors in the chloroplasts of the transgenic plants. The differences in lipid composition had only minor effects on measured functions of the photosynthetic apparatus, whereas the most obvious phenotype was a significant reduction in growth.}, language = {en} } @article{FuchsLederer2007, author = {Fuchs, Doris and Lederer, Markus}, title = {The power of business}, issn = {1469-3569}, year = {2007}, language = {en} } @article{FuhrmannSeehaferValori2007, author = {Fuhrmann, Marcel and Seehafer, Norbert and Valori, Gherardo}, title = {Preprocessing of solar vector magnetograms for force-free magnetic field extrapolation}, issn = {0004-6361}, doi = {10.1051/0004-6361:20078454}, year = {2007}, abstract = {Context. Reliable measurements of the solar magnetic field are restricted to the phoptosphere. As an alternative to measurements, the field in the higher layers of the atmosphere is calculated from the measured photospheric field, mostly under the assumption that it is force-free. However, the magnetic field in the photosphere is not force-free. Moreover, most methods for the extrapolation of the photospheric magnetic field into the higher layers prescribe the magnetic vector on the whole boundary of the considered volume, which overdetermines the force-free field. Finally, the extrapolation methods are very sensitive to small-scale noise in the magnetograph data, which, however, if sufficienly resolved numerically, should affect the solution only in a thin boundary layer close to the photosphere. Aims. A new method for the preprocessing of solar photospheric vector magnetograms has been developed that, by improving their compatibility with the condition of force- freeness and removing small-scale noise, makes them more suitable for extrapolations into three- dimensional nonlinear force-free magnetic fields in the chromosphere and corona. Methods. A functional of the photospheric field values is minimized whereby the total magnetic force and the total magnetic torque on the considered volume above the photosphere, as well as a quantity measuring the degree of small-scale noise in the photospheric boundary data, are simultaneously made small. For the minimization, the method of simulated annealing is used and the smoothing of noisy magnetograph data is attained by windowed median averaging. Results. The method was applied to a magnetogram derived from a known nonlinear force-free test field to which an artificial noise had been added. The algorithm recovered all main structures of the magnetogram and removed small- scale noise. The main test was to extrapolate from the noisy photospheric vector magnetogram before and after the preprocessing. The preprocessing was found to significantly improve the agreement of the extrapolated with the exact field.}, language = {en} } @article{FussmannWeithoffYoshida2007, author = {Fussmann, Gregor F. and Weithoff, Guntram and Yoshida, Takehito}, title = {A direct, experimental test of resource versus consumer dependence : reply}, issn = {0012-9658}, doi = {10.1890/06-1692}, year = {2007}, language = {en} } @article{Fery2007, author = {F{\´e}ry, Caroline}, title = {Information structural notions and the fallacy of invariant correlates}, isbn = {978-3-939469-88-9}, year = {2007}, language = {en} } @article{Fery2007, author = {F{\´e}ry, Caroline}, title = {The fallacy of invariant phonological correlates of Information structural Notions}, isbn = {978-3-939469-88-9}, year = {2007}, language = {en} } @article{Fery2007, author = {F{\´e}ry, Caroline}, title = {The prosodic basis of of Topicalization}, isbn = {978-90-272-3364-6}, year = {2007}, language = {en} } @article{Fery2007, author = {F{\´e}ry, Caroline}, title = {Information structural notions and the fallacy of invariant correlates}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19692}, year = {2007}, abstract = {In a first step, definitions of the irreducible information structural categories are given, and in a second step, it is shown that there are no invariant phonological or otherwise grammatical correlates of these categories. In other words, the phonology, syntax or morphology are unable to define information structure. It is a common mistake that information structural categories are expressed by invariant grammatical correlates, be they syntactic, morphological or phonological. It is rather the case that grammatical cues help speaker and hearer to sort out which element carries which information structural role, and only in this sense are the grammatical correlates of information structure important. Languages display variation as to the role of grammar in enhancing categories of information structure, and this variation reflects the variation found in the 'normal' syntax and phonology of languages.}, language = {en} } @article{FeryFanselowKrifka2007, author = {F{\´e}ry, Caroline and Fanselow, Gisbert and Krifka, Manfred}, title = {Introduction}, isbn = {978-3-939469-88-9}, year = {2007}, language = {en} } @article{FeryFanselowPaslawska2007, author = {F{\´e}ry, Caroline and Fanselow, Gisbert and Paslawska, Alla}, title = {Nominal Split Construction in Ukrainian}, year = {2007}, language = {en} } @article{FerySkopeteas2007, author = {F{\´e}ry, Caroline and Skopeteas, Stavros}, title = {Contrastive Topics in Pairing Answers : a Cross-Linguistic Production Study}, isbn = {3-11-019315-9}, year = {2007}, language = {en} } @article{Gaedke2007, author = {Gaedke, Ursula}, title = {Spectral analysis unmasks synchronous and compensatory dynamics in plankton communities}, year = {2007}, language = {en} } @article{GastModler2007, author = {Gast, Klaus and Modler, Andreas Johannes}, title = {Dynamic and static light scattering of proteins}, isbn = {978-1-600-21704-3}, year = {2007}, language = {en} } @article{GebserGharibSchaub2007, author = {Gebser, Martin and Gharib, Mona and Schaub, Torsten H.}, title = {Incremental answer sets and their computation}, year = {2007}, language = {en} } @article{GebserKaufmannNeumannetal.2007, author = {Gebser, Martin and Kaufmann, Benjamin and Neumann, Andr{\´e} and Schaub, Torsten H.}, title = {Conflict-driven answer set enumeration}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{GebserKaufmannNeumannetal.2007, author = {Gebser, Martin and Kaufmann, Benjamin and Neumann, Andr{\´e} and Schaub, Torsten H.}, title = {Conflict-driven answer set solving}, isbn = {978-1-57735-323-2}, year = {2007}, language = {en} } @article{GebserKaufmannNeumannetal.2007, author = {Gebser, Martin and Kaufmann, Benjamin and Neumann, Andr{\´e} and Schaub, Torsten H.}, title = {Clasp : a conflict-driven answer set solver}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{GebserLeeLierler2007, author = {Gebser, Martin and Lee, Joohyung and Lierler, Yuliya}, title = {Head-elementary-set-free logic programs}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{GebserLiuNamasivayametal.2007, author = {Gebser, Martin and Liu, Lengning and Namasivayam, Gayathri and Neumann, Andr{\´e} and Schaub, Torsten H. and Truszczynski, Miroslaw}, title = {The first answer set programming system competition}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{GebserSchaub2007, author = {Gebser, Martin and Schaub, Torsten H.}, title = {Generic tableaux for answer set programming}, year = {2007}, language = {en} } @article{GebserSchaubThiele2007, author = {Gebser, Martin and Schaub, Torsten H. and Thiele, Sven}, title = {GrinGo : a new grounder for answer set programming}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{GebserSchaubTompitsetal.2007, author = {Gebser, Martin and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {Alternative characterizations for program equivalence under aswer-set semantics : a preliminary report}, year = {2007}, language = {en} } @phdthesis{Geiger2007, author = {Geiger, Sonja Maria}, title = {If there are exceptions, it is still a rule : a probabilistic understanding of conditionals}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13113}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Numerous recent publications on the psychological meaning of "if" have proposed a probabilistic interpretation of conditional sentences. According to the proponents of probabilistic approaches, sentences like "If the weather is nice, I will be at the beach tomorrow" (or "If p, then q" in the abstract version) express a high probability of the consequent (being at the beach), given the antecedent (nice weather). When people evaluate conditional sentences, they assumingly do so by deriving the conditional probability P(q|p) using a procedure called the Ramsey test. This is a contradicting view to the hitherto dominant Mental Model Theory (MMT, Johnson-Laird, 1983), that proposes conditional sentences refer to possibilities in the world that are represented in form of mental models. Whereas probabilistic approaches gained a lot of momentum in explaining the interpretation of conditionals, there is still no conclusive probabilistic account of conditional reasoning. This thesis investigates the potential of a comprehensive probabilistic account on conditionals that covers the interpretation of conditionals as well as conclusion drawn from these conditionals when used as a premise in an inference task. The first empirical chapter of this thesis, Chapter 2, implements a further investigation of the interpretation of conditionals. A plain version of the Ramsey test as proposed by Evans and Over (2004) was tested against a similarity sensitive version of the Ramsey test (Oberauer, 2006) in two experiments using variants of the probabilistic truth table task (Experiments 2.1 and 2.2). When it comes to decide whether an instance is relevant for the evaluation of a conditional, similarity seems to play a minor role. Once the decision about relevance is made, believability judgments of the conditional seem to be unaffected by the similarity manipulation and judgments are based on frequency of instances, in the way predicted by the plain Ramsey test. In Chapter 3 contradicting predictions of the probabilistic approaches on conditional reasoning of Verschueren et al (2005), Evans and Over (2004) and Oaksford \& Chater (2001) are tested against each other. Results from the probabilistic truth table task modified for inference tasks supports the account of Oaksford and Chater (Experiment 3.1). A learning version of the task and a design with every day conditionals yielded results unpredicted by any of the theories (Experiments 3.2-3.4). Based on these results, a new probabilistic 2-stage model of conditional reasoning is proposed. To preclude claims that the use of the probabilistic truth table task (or variants thereof) favors judgments reflecting conditional probabilities, Chapter 4 combines methodologies used by proponents of the MMT with the probabilistic truth table task. In three Experiments (4.1 -4.3) it could be shown for believability judgments of the conditional and inferences drawn from it, that causal information about counterexamples only prevails, when no frequencies of exceptional cases are present. Experiment 4.4 extends these findings to every day conditionals. A probabilistic estimation process based on frequency information is used to explain results on all tasks. The findings confirm with a probabilistic approach on conditionals and moreover constitute an explanatory challenge for the MMT. In conclusion of all the evidence gathered in this dissertation it seems justified to draw the picture of a comprehensive probabilistic view on conditionals quite optimistically. Probability estimates not only explain the believability people assign to a conditional sentence, they also explain to what extend people are willing to draw conclusions from those sentences.}, language = {en} } @misc{Gerhard2007, author = {Gerhard, Reimund}, title = {Katzir, S., The beginnings of piezoelectricity: a study in mundane physics; Dordrecht, Springer, 2006}, year = {2007}, language = {en} } @article{GermerNeillKruscheetal.2007, author = {Germer, Sonja and Neill, Christopher and Krusche, Alex V. and Neto, Sergio Gouveia and Elsenbeer, Helmut}, title = {Seasonal and within-event dynamics of rainfall and throughfall chemistry in an open tropical rainforest in Rond{\^o}nia, Brazil}, issn = {0168-2563}, doi = {10.1007/s10533-007-9152-9}, year = {2007}, abstract = {Prolonged dry periods, and increasingly the generation of smoke and dust in partially-deforested regions, can influence the chemistry of rainfall and throughfall in moist tropical forests. We investigated rainfall and throughfall chemistry in a palm-rich open tropical rainforest in the southwestern Brazilian Amazon state of Rondonia, where precipitation averages 2300 mm year(-1) with a marked seasonal pattern, and where the fragmentation of remaining forest is severe. Covering the transition from dry to wet season (TDWS) and the wet season (WS) of 2004-2005, we sampled 42 rainfall events on event basis as well as 35 events on a within-event basis, and measured concentrations of DOC, Na+, K+, Ca2+, Mg2+, NH4+ , Cl-, SO42- , NO3- and pH in rainfall and throughfall. We found strong evidence of both seasonal and within-event solute rainfall concentration dynamics. Seasonal volume-weighted mean (VWMS) concentrations in rainfall of DOC, K+, Ca2+, Mg2+, NH4+ , SO42- and NO3- were significantly higher in the TDWS than the WS, while VWMS concentrations in throughfall were significantly higher for all solutes except DOC. Patterns were generally similar within rain events, with solute concentrations declining sharply during the first few millimeters of rainfall. Rainfall and throughfall chemistry dynamics appeared to be strongly influenced by forest and pasture burning and a regional atmosphere rich in aerosols at the end of the dry season. These seasonal and within-event patterns of rainfall and throughfall chemistry were stronger than those recorded in central Amazonia, where the dry season is less pronounced and where regional deforestation is less severe. Fragmentation and fire in Rondonia now appear to be altering the patterns in which solutes are delivered to remaining moist tropical forests.}, language = {en} } @article{GharibSchaubMercer2007, author = {Gharib, Mona and Schaub, Torsten H. and Mercer, Robert E.}, title = {Incremental answer set programming : a preliminary report}, year = {2007}, language = {en} } @phdthesis{GholamiGhadikolaei2007, author = {Gholami Ghadikolaei, Iraj}, title = {Data analysis of continuous gravitational waves}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18800}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {This thesis describes two main projects; the first one is the optimization of a hierarchical search strategy to search for unknown pulsars. This project is divided into two parts; the first part (and the main part) is the semi-coherent hierarchical optimization strategy. The second part is a coherent hierarchical optimization strategy which can be used in a project like Einstein@Home. In both strategies we have found that the 3-stages search is the optimum strategy to search for unknown pulsars. For the second project we have developed a computer software for a coherent Multi-IFO (Interferometer Observatory) search. To validate our software, we have worked on simulated data as well as hardware injected signals of pulsars in the fourth LIGO science run (S4). While with the current sensitivity of our detectors we do not expect to detect any true Gravitational Wave signals in our data, we can still set upper limits on the strength of the gravitational waves signals. These upper limits, in fact, tell us how weak a signal strength we would detect. We have also used our software to set upper limits on the signal strength of known isolated pulsars using LIGO fifth science run (S5) data.}, language = {en} } @phdthesis{Glushak2007, author = {Glushak, Ksenia}, title = {Atmospheric circulation and the surface mass balance in a regional climate model of Antarctica}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17296}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Understanding the Earth's climate system and particularly climate variability presents one of the most difficult and urgent challenges in science. The Antarctic plays a crucial role in the global climate system, since it is the principal region of radiative energy deficit and atmospheric cooling. An assessment of regional climate model HIRHAM is presented. The simulations are generated with the HIRHAM model, which is modified for Antarctic applications. With a horizontal resolution of 55km, the model has been run for the period 1958-1998 creating long-term simulations from initial and boundary conditions provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA40 re-analysis. The model output is compared with observations from observation stations, upper air data, global atmospheric analyses and satellite data. In comparison with the observations, the evaluation shows that the simulations with the HIRHAM model capture both the large and regional scale circulation features with generally small bias in the modeled variables. On the annual time scale the largest errors in the model simulations are the overestimation total cloud cover and the colder near-surface temperature over the interior of the Antarctic plateau. The low-level temperature inversion as well as low-level wind jet is well captured by the model. The decadal scale processes were studied based on trend calculations. The long-term run was divided into two 20 years parts. The 2m temperature, 500 hPa temperature, MSLP, precipitation and net mass balance trends were calculated for both periods and over 1958 - 1998. During the last two decades the strong surface cooling was observed over the Eastern Antarctica, this result is in good agreement with the result of Chapman and Walsh (2005) who calculated the temperature trend based on the observational data. The MSLP trend reveals a big disparity between the first and second parts of the 40 year run. The overall trend shows the strengthening of the circumpolar vortex and continental anticyclone. The net mass balance as well as precipitation show a positive trend over the Antarctic Peninsula region, along Wilkes Land and in Dronning Maud Land. The Antarctic ice sheet grows over the Eastern part of Antarctica with small exceptions in Dronning Maud Land and Wilkes Land and sinks in the Antarctic Peninsula; this result is in good agreement with the satellite-measured altitude presented in Davis (2005) . To better understand the horizontal structure of MSLP, temperature and net mass balance trends the influence of the Southern Annual Mode (SAM) on the Antarctic climate was investigated. The main meteorological parameters during the positive and negative Antarctic Oscillation (AAO) phases were compared to each other. A positive/negative AAO index means strengthening/weakening of the circumpolar vortex, poleward/northward storm tracks and prevailing/weakening westerly winds. For detailed investigation of global teleconnection, two positive and one negative periods of AAO phase were chosen. The differences in MSLP and 2m temperature between positive and negative AAO years during the winter months partly explain the surface cooling during the last decades.}, language = {en} } @phdthesis{Goldobin2007, author = {Goldobin, Denis S.}, title = {Coherence and synchronization of noisy-driven oscillators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15047}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {In the present dissertation paper we study problems related to synchronization phenomena in the presence of noise which unavoidably appears in real systems. One part of the work is aimed at investigation of utilizing delayed feedback to control properties of diverse chaotic dynamic and stochastic systems, with emphasis on the ones determining predisposition to synchronization. Other part deals with a constructive role of noise, i.e. its ability to synchronize identical self-sustained oscillators. First, we demonstrate that the coherence of a noisy or chaotic self-sustained oscillator can be efficiently controlled by the delayed feedback. We develop the analytical theory of this effect, considering noisy systems in the Gaussian approximation. Possible applications of the effect for the synchronization control are also discussed. Second, we consider synchrony of limit cycle systems (in other words, self-sustained oscillators) driven by identical noise. For weak noise and smooth systems we proof the purely synchronizing effect of noise. For slightly different oscillators and/or slightly nonidentical driving, synchrony becomes imperfect, and this subject is also studied. Then, with numerics we show moderate noise to be able to lead to desynchronization of some systems under certain circumstances. For neurons the last effect means "antireliability" (the "reliability" property of neurons is treated to be important from the viewpoint of information transmission functions), and we extend our investigation to neural oscillators which are not always limit cycle ones. Third, we develop a weakly nonlinear theory of the Kuramoto transition (a transition to collective synchrony) in an ensemble of globally coupled oscillators in presence of additional time-delayed coupling terms. We show that a linear delayed feedback not only controls the transition point, but effectively changes the nonlinear terms near the transition. A purely nonlinear delayed coupling does not affect the transition point, but can reduce or enhance the amplitude of collective oscillations.}, language = {en} } @phdthesis{Grafmueller2007, author = {Grafm{\"u}ller, Andrea}, title = {The fusion of membranes and vesicles}, address = {Potsdam}, pages = {VII, 133 S. : Ill., graph. Darst.}, year = {2007}, language = {en} } @article{GreffetHenkel2007, author = {Greffet, Jean-Jacques and Henkel, Carsten}, title = {Coherent thermal radiation}, issn = {0010-7514}, year = {2007}, abstract = {The radiation emitted by a heated body is generally quoted as a typical example of incoherent radiation, in distinction to laser radiation. One is nearly isotropic, the other highly directional; one is spectrally broad, the other quasi-monochromatic. It may come as a surprise that the thermal radiation of a large number of substances is coherent, both in space and time, when it is observed at a distance from the body that is shorter than the wavelength. This behaviour can be understood within an electromagnetic approach to thermal emission. Several recent experiments have confirmed these unexpected properties.}, language = {en} }